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内容:Intelligent controlled facades are designed to use outdoor climate as much as possible for indoor climate aspects:heating ,cooling ventilating and day-lighting .In this paper one aspect will be discussed in more deatil:cooling by natural ventilation .The efficiency of this type of cooling is demonstrated by simulation and by monitoring in real office buildings.Design tools are derived for designing the vent openings in the facade and machines require additional air conditioning ,but even then intelligent facades will help to reduce energy costs of running the air conditioning at the moment.The height of the applicaton of intelligent features in uildings is the double skin facade.A short description will be given.
标题:ANALYSIS METHODS FOR NATURAL AND HYBRID VENTILATIONAN IEA ECB ANNEX 35 LITERATURE REVIEW
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内容:Annex 35 is an International Energy Agency(IEA) task-sharing project which commenced on 1 August 1998 for a duration of four years, and in which fifteen countries participate. The objectives of Annex 35 are to promote energy-and cost-effective hybrid ventilation systems and develop control strategies and performance analysis methods for office and educational buildings . This paper presents a critical literature review of the key available mathematical analysis methods that are applicable to natural and hybrid ventilation. It includes a review of some significant issues and areas of further development ,including applicability to dirrerent design stages, large openings ,input data requirement , application of analysis methods to hybrid ventilation ,deterministic versus stochastic ,integration with thermal modelling ,evaluation of analysis methods ,and development of methods for opening sizing .Planned work in the area of analysis methods in Annex 35is summarised.
标题:SIMULATION APPLICATION IN COMMERCIAL BUILDING ENVIRONMENT DESIGN
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内容:Simulation is a basic part of the decision process .It should be used at all stages of building life cycle .But modelling refinements must be adapted to the problems to be solved
.Simplifications are required ,not for the computer ,but for our own understanding .Nodal and admitance models are good examples of such simplification .HVAC equipment modelling and simulation include not prestigious tasks .Its,among others , necessary to perform a very careful counting of so called auxiliary consumption(pumps fans...). This appears as not auxiliary at all ,with respect to the global energy balance. The most challenging developments for the future are located more or less at both ends of building life cycle :very early design and commissioning .
标题:Control and Fault Detection in Buildings
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内容:The paper considers the problems that are associated with the design of building fault detection and control systems. Direct and indirect approacher to the design of controllers and fault detectors are described .A number of proposed schemes are compared before the key issues are identified . The advantages of a neurouzzy model-bases approach are then explained . Work on current research projects , which are using this approach to develop a robust fault diagnosis scheme for air -handlers , an air temperature sensor for heating ,ventilation of air -conditioning applications , a new type of thermal comfort control scheme , and a fault-tolerant supervisory control scheme for air-conditioning systems ,is also reviewed.
标题:BASIC STUDY OF AQUIFER THERMAL ENERGY STORAGE: AN INVESTIGA TION OF FERRIC COLLOIDAL DAM IN AN AQUIFER
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内容:As a result of the field experiments on the aquifer thermal energy storage for 9 years ,the thermal recovery factor (recovered thermal energy/charged thermal energy) has improved from 23% in the first year to 63% in the 8th . We have noted the importance of ferric colloid (Fe2O3·nH2O). In the aquifer ,the clogging of the ferric colloidal dam in the vacant spaces of the aquifer prevented the natural flow of groundwater around the well, which increased the recovery factor significantly .In this paper, a fundamental model for describing the clogging phenomena in the aquifer by the ferric colloid is proposed , and this shows a good agreement with the results of the one -dimensional experiment . The limits of the colloidal dam in the aquifer were measured by the modified Wenner method using 160 electrodes fixed previously from which the area of thermal energy storage could be obtained .
标题:The underlying theme of this conference is sustainability ,especially with respect to HVAC designer , equipment installet building
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内容:The underlying theme of this conference is sustainability ,especially with respect to HVAC designer , equipment installet building
标题:BUIDLING ENVIRONMENTAL ASSESSMENT SCHEMES AND SUSTAINABLE HVAC
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内容:The underlying theme of this conference is sustainability, especially with respect to HVAC systems. However, this is a very broad and complex issue. To the HVAC designer, equipment installer or building operator it is more relevant to talk about efficiency, on the basis that the best levels of efficiency should enhance sustainability. Even so, defining HVAC system efficiency is also difficult, given the problem inherent in quantifying the output. Many large centrally air-conditioned buildings fail in performance, either in terms of the quality of the indoor environment, in terms of energy use, etc. It raises a question about the ability of building services engineers to deliver performance, despite the wide range of solutions currently available. In the next millennium, engineers will find that many non-technical issues will need to be understood and resolved alongside good quality engineering design, installation and operation. Health and safety, and impact on the environment are bringing new challenges to engineers who need to respond with good solutions, despite ever-present economic pressures. The environmental assessment of buildings is somewhat new to Asia. However, should take -up of such schemes become more widespread, engineers will be required to meet new specifications in respect of environmental performance. In this paper the development of such schemes is discussed in the context of densely populated cities, such as Hong Kong .
标题:DEVELOPMENT OF A COMPUTATIONAL THERMAL MANIKIN
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内容: This paper develops a numerical simulation method to address heat and mass transfer characteristics of the human body. This numerical method is called the computational Thermal Manikin (CTM). The CTM is a combined simulation system of airflow, moisture transport, and thermal radiation including a human thermo-physiological model. Airflow, moisture transport, and thermal radiation including a human thermo-physiological model. Airflow, temperature , and moisture field are simulated using three dimensional computational Fluid Dynamics (CFD). CFD uses a low-Reynolds-number type k-εturbulence model, with the generalized curvilinear coordinate system (Boundary Fitted Coordinates) to represent the complicated shape of the human body. Thermal radiation is calculated by means of Gebharts absorption factor method, and view factors are obtained using the Monte Carlo method. Gagges two-node model is included to simulate the metabolic heat production and the thermoregu-latory control processes of the human body. Furthermorem this paper presents two application samples of the CTM. One is to evaluate thermal sensation through indexes such as PMV or SET* , ETC, which is based on obtained heat transfer characteristics of human body. T he other application for the CTM is to assess air quality in the breathing level based on the predicted microclimate around the human body. The predicted results are very close to those of an actual human body in a similar situation.
标题:HUMAN REQUIREMENTS IN FUTURE AIR-CONDITIONED ENVIRONMENTS: A SEARCH FOR EXCELLENCE
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内容:Although air-conditioning has played a positive role for economic development in warm climates, its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from SBS symptoms, even though existing standards and guidelines are met. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in the 21st century . Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence: better indoor air quality increases productivity and decreases SBS symptoms; unnecessary indoor pollution sources should be avoided; the air should be served cool and dry to the occupants; small amounts of clean air should be served gently , close to the breathing zone of each individual; individual control of the thermal environment should be provided. These principles of excellence are compatible with energy efficiency and sustainability.
标题:SUSTAINABLE BUILDINGS FOR CHINESE URBAN AREAS
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内容:A cooperative program is underway between the Massachusetts Institute of Technology and Tsinghua University for sustainable building designs in Chinese Cities. The initial focus of the MIT effort is on residential structures suitable for Beijing and Shanghai . Natural ventilation could provide comfortable conditions for a portion of the cooling season. This requires careful design of building interiors as well as the exterior of individual buildings ans building groups . Computational fluid dynamics allows the most promising designs to be explored. Careful design of buildings will help to minimize solar gains in the summer. Other technologies under study include ground coupled heat pumps and dehumidification systems. The use of such technologies and designs will be reviewed.
标题:OPTIMIZATION OF DESIGN AND CONTROL OF HAVC
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内容:How HVAC is optimized for the sake of building owners is discussed. Ideal process should be pursued, while actual business styles cannot be neglected. In the era the PC becomes for everyone use, how the future design and management process making the ideal and actual figures compatible will be? What is to be recognized is that HVAC performance shall be evaluated in long range. What shall be used as the design and control tools are computer technology. On the other hand , the more the computer becomes high performance, the less the designers use it in real engineering process, while the presentation style becomes sophisticated more an more, and the real quality becomes the lower. A greatest dilemma to be solved for optimization of design and controls of HVAC lies at the early stage of twenty first century.
标题:THE THERMAL COMFORT ANALYSIS UNDER DIFFERENT AIR DISTRIBUTION STRATEGIES IN A BUILDING
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内容:The evaluation of various ventilation strategies for optimal thermal comfort design in terms of predicted mean vote index was investigated. The major parameter is the inlet/outlet diffusers locations in the occupied region. The location effects of the inlet and outlet diffusers at the ceiling/walls on thermal comfort were examined every 0.4 meter. Eight different air distribution systems including single inlet- single outlet and single inlet- double outlets arrangements were studied in an indoor environment. Also, an experimental validation was conducted. The comparison results between prediction and test are quite well.
标题:FAN AIR SPEED CONTROLS ASSISTED BY HUMAN RESPONSE SIMULATION FOR COMFORT IN WARM ENVIRONMENTS
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内容:Ceiling fans are a good low energy means to reduce warm discomfort in buildings. Two automatic ceiling fan systems are described that regulate air speed to maintain comfort in changing conditions. The simpler system, based on the ASHRAE comfort standard, responds only to temperature . The other uses the PMV comfort model to regulate the air speed. In comfort test at 29C and 50% RH both automatic systems provided the same level of comfort at steady state conditions as manual control. However the automatic systems were faster in bringing the subjects to comfort. The comfort performance of the two automatic systems were also compared during a temperature down drift from 29 C to 25C and the PMV system was compared to manual control during humidity changes.
标题:AN AUTOMATIC WINDOW OPENING SYSTEM FOR COMFORT CONTROL ASSISTED BY HUMAN RESPONSE SIMULATION
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内容:In many parts of the world and during a good part of the year, comfort can be attained or improved with minimal energy by just opening or adjusting the window. The air flow through the window opening can reduce the temperature and humidity and increase air motion in the space, all leading to reduced warm discomfort. This approach to energy conservation can be also be done with a system developed and tested in this paper, comparison tests with the window automatically controlled and with the window manually adjusted by the occupant shows both were equally successful in providing comfort.
标题:EFFECTS OF AIR TURBULENCE ON HUMAN THERMAL SENSATI
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内容:Air movement can provide desirable cooling in "warm" conditions, but it can also cause unhappy feelings. This study focuses on the effects of air turbulence on human thermal sensations through nvestigating the preferred air velocity within the temperature range of 26℃ and 30.5℃. Subjects in an environmental chamber were allowed to adjust air movement as they pleased while answering a series of questions about their thermal comfort. From the analysis of the results, operative temperature, turbulence intensity and subject all have effects on preferred velocities. The increased temperature enhances the discreteness of the preferred velocity, while the increased turbulence decreases and concentrates the preferred velocity. Most subjects can achieve comfort under the experimental conditions after adjusting the air velocity as they pleased. The temperature has more significant effect on the comfort vote than turbulence intensity of the air movement. Turbulence of the air movement may induce draft in cool-to-neutral conditions, while it can release drafty risk in neutral -to-warm conditions. The annoying effect by the air pressure at higher temperature should not be ignored.
标题:EFFECTS OF AIR TURBULENCE ON HUMAN THERMAL SENSATION IN WARM ISOTHERMAL ENVIRONMENT
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内容:Air movement can provide desirable cooling in "warm" conditions, but it can also cause unhappy feelings. This study focuses on the effects of air turbulence on human thermal sensations through nvestigating the preferred air velocity within the temperature range of 26℃ and 30.5℃. Subjects in an environmental chamber were allowed to adjust air movement as they pleased while answering a series of questions about their thermal comfort. From the analysis of the results, operative temperature, turbulence intensity and subject all have effects on preferred velocities. The increased temperature enhances the discreteness of the preferred velocity, while the increased turbulence decreases and concentrates the preferred velocity. Most subjects can achieve comfort under the experimental conditions after adjusting the air velocity as they pleased. The temperature has more significant effect on the comfort vote than turbulence intensity of the air movement. Turbulence of the air movement may induce draft in cool-to-neutral conditions, while it can release drafty risk in neutral -to-warm conditions. The annoying effect by the air pressure at higher temperature should not be ignored.
标题:SIMULATION OF THE NATURAL WIND WITH A NEW METHOD
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内容:Based on the analysis of the natural wind spectra, a new method for generating an air movement with the same velocity spectra as the natural wind is presented. Correspondingly a new device using this method is designed to investigate the velocity fields. The key part of the device is controlled by a digital signal, which can be regulated according to the test needs. The frequency scope of the velocity spectra and the turbulence intensity can be easily changed in order to satisfy the air conditioning need, so a series of modes of the natural wind can be simulated. The investigation shows that is application in dynamic air conditioning is applicable .
标题:ENVIRONMENTAL ODOUR CONTROL FOR SUSTAIN ABLE DEVELOPMENT OF PUBLIC ODOROUS PREMISES IN URBAN AREAS
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内容:Environmental friendliness is one the key elements in the sustainable development and siting of public odorous premised. This can only e achieved by adopting effective odour control design in HVAC systems. Odour nuisance presents one of the most difficult tasks to be handled. The lack of a scientific approach and a clear statutory guideline has made the problem even more complicated . This lack of a scientific approach and a clear statutory guideline has made the problem even more complicated. This paper will give an outline of Building Services Branchs experience in the design and implementation of appropriate odour abatement measures for the public odorous premises such as refuse collection points, markets , cooked food centres, slaughter houses, public toilets, etc. for Government method and the acceptable odour criteria. The available technologies and mitigation measures to combat odour as well as their advantageous and drawback will be discussed based on the experience in application. Recent concern on indoor hygiene and air quality has fostered new design for odour treatment and discussion will be made on some new proposals adopted.
标题:CHARACTERISATION OF VOLTAILE ORGANIC COMPOUNDS IN OFFICE/RESIDENTIAL BUILDINGS IN HONG KONG
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内容:Various types of volatile organic compounds (VOCs) have been found to exist in different indoor environments. They usually exist in levels that are below recommended standards. However, the combined effect can be significant. Use of chemical filtration units in the market do not perform as effectively as the manufacturers claimed. One reason is that the testing conditions were usually different form the actual condition on sites and information on VOCs in the indoor environment is scare. The Hong Kong University and Engineering (HK) Ltd. On developing a new chemical based filtration unit. Phase one of our study was to identify and to quantify the VOCs on various office premises in HongKong using both GC/MS and PAS techniques. In this paper, measurement results on various office buildings , new renovated domestic buildings and office buildings were presented to charcterize the most abundant volatile organic compounds and their levels under various air conditioning conditions. Operation pattern of the air-conditioning system, ventilation rate, surrounding VOC levels and indoor characteristics all showed significant influence on the indoor VOC levels. Discussion of our testing device and study protocol is also included in this paper.
标题:NOMINAL TIME FOR FULL-MIXING OF CONTAMINANT DUE TO DIFFERENT SOURCE LOCATION
关键字:Contaminant Source Location; Ventilation Air flow Rate; Full-Mixing; Model Test; Mixing Ventilation
内容:Mixing ventilation was studied by conducting model tests in the laboratory. The contaminant source location and the ventilation air flow rate are the factors tested to understand their effect on the mixing of contaminants internally generated with ventilation air in the model room. The model room represented a typical small room with the mixing ventilation having an inlet on the side wall. The test were conducted under transient isothermal conditions. Pulse tracer technique was applied to test the effects.
Under the same ventilation air flow field , the contaminant source created different mixing of generated contaminants with the ventilation air in the model room due to its location. It implies that the contaminant mixing could be improved by relocating the contaminant source within the room without changing the ventilation system. In this study, it has been found that a certain contaminant source location is significantly better than others in achieving better mixing in the model room.
The ventilation air flow rate also affected the mixing process. The contaminant removal efficiency increased with the ventilation air flow rate, but not linearly. Increasing the ventilation air flow rate, however , could not be always the answer to improve the indoor air quality.
Finally, a strategy to combine the two factors examined is suggested to minimize the requirement for the indoor air quality improvement . The optimal contaminant source location , In particular, needs to be decided by considering the air flow pattern in the room.
标题:VOCs-AN INDOOR AIR QUALITY ISSUE IN OFFICE OFFICE
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内容:Recent studies show that buildings occupants are exposed to different indoor air contaminants that effect occupants comfort , health and productivity. This paper briefly review the issue of VOCs in indoor environment , its effect on occupants health , the standards and guideline, modelling and finally the impact of indoor environment parameters on the material emission rate.
标题:THE OPTIMIZATION OF INDOOR AIR DESIGN CONDITIONS
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内容:To deal with the coaly urban urban air pollution , regional sulfuric acid rain and global warming , we take specific measures to control the emissions of sulfur dioxide and carbon dioxide. According to the regional characteristics of Chongqing where the problem of acid rain has arisen attentions from both home and aboard. So it is an urgent demand in Chongqing region to formulate a feasible , high efficiency scenarios for mitigating the emission of air pollutants to accelerate the improvement effect and acquire economic benefit as much as possible , we use TLCC (Total Life Cycle Cost) analysis method to evaluate the effectiveness of energy technologies, to present the corresponding mitigation scenarios and to draw upon some suggestion. Therefore provide a reliable criteria for policy making.
标题:NEW FUNCTION FOR INDOOR AIR QUALITY EVALUATION
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内容:This paper is derived a functional expression for evaluating the indoor air quality from the generalized Weber-Fechners law and the Fangers "olf method" , as well as the Geman VDI method.
标题:ARTIFICIAL NEURAL NETWORK MODEL FOR PMV PREDICTION
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内容:Research into thermal comfort may be conducted in the laboratory or in the field. The two approaches are different and are both necessary. The scientific attraction of laboratory experiments is that it is possible to isolate one or two variables and study the effect on subjects of changing their values while keeping all other environmental variables constant.
PMV prediction model for field survey is more practical and useful. But this model is complex in mechanism and very difficult to cope with. Subjects should be assigned randomly to different conditions , and it is necessary to avoid the production of false results. Many efforts have been made in this field, but are not well satisfied on their concept clarity, calculation simplicity , process dynamic characteristics ,resultant precision, etc..
An Artificial Neural Network (Much similar to neural network of human body) for PMV prediction of Artificial Neural Network to solve all puzzles we met before. Concrete analysis and methods are provided and discussed here in order to make great improvement on traditional PMV prediction method for field survey. The principle of an integrate PMV predictor and its possible applications are also showed within this paper.
标题:INFLUENCE OF WATER CONTAMINATION IN AIR-CONDITIONING SYSTEM ON INDOOR AIR QUALITY AND PROVITING MEASURES
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内容:Air-conditioning water system pollution and the influences on indoor air quality were illustrated. The countermeasures to prevent water pollution were proposed. Analysis indicates that increasing the quantity of fresh air is not the unique method to improve indoor air quality. And preventing the pollution in air-conditioning water system can not only create healthy and comfortable indoor environment but also protect outside-door environment with less energy consumption.
标题:PPORTUNITIES TO MAINTAIN THERMAL COMFORT IN BEIJING HOUSING WITHOUT VAPOR COMPRESSION COOLING EQUIPMENT
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内容:This paper investigates whether careful attention to architectural design and use of mechanical ventilation are sufficient to maintain thermal comfort in dwellings in Beijing , without the use of vapor-compression air-conditioning equipment. The study was motivated by a desire to define strategies that would reduce building operating costs, energy demands, potential environmental impacts associated with energy usage , and potential occupant dissatisfaction with air conditioning, due to reduced outdoor-air intake and large temperature changes associated with entering or leaving a building . Results show that drastically lowering solar gains and use of large, fan-driven , airflows at night are sufficient to reduce indoor peak temperatures to as low as 29℃, when the outdoor peak is 33℃. Further reductions to 26.5℃ if possible as internal gains are reduced to the limit of being completely eliminated.
标题:MODELLING BUILDING PERFORMANCE
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内容:This paper describes the application of modeling for predicting energy and environmental performance of buildings. Two area of modeling will be discussed. Computer modeling enables the performance of buildings to be predicted at design stage. The dynamic building energy model HTB2 has been developed at the centre. This can be used to predict seasonal energy performance on an hourly time-scale, taking account of the building construction , its occupancy and its location. Examples will be given of the use of HTB2 for research and design consultancy. HTB2 is used in the Hong Kong building environmental assessment model , HK-BEAM, for office buildings. CFD to predict natural and mixed-mode ventilation performance will be described. Scale modeling of buildings in a boundary layer wind tunnel can be used to predict wind effects on ventilation performance. Examples will be discussed with reference to case studies of offices on ventilation performance spaces. The pressure coefficients measured in the wind tunnel can be used as boundary conditions for CFD predictions of ventilation performance. The impact of daylight and sunlight on building design can be modeled in an artificial sky/ heliodon. The newly constructed8 m diameter domed sky at the Centre will be described and examples given of its use.
标题:EFFECTIVENESS OF CAR PARKS VENTILATION
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内容: The building code in Singapore specifies the number of air changes per hour that a car park area in a building should be provided with and that half the amount of exhaust air should be extracted from a low level. Other than that, a designer is free to locate the extraction points to ventilate the car park. Experience has shown that a poor positioning of the extraction points can cause some part of the car park to be poorly ventilated and the air may even become stagnant there. This study made use of CFD modeling to look into the performance of four different arrangements of the extraction points in a small car park . The average period that the polluted air stayed in the car park and the associated air exchange efficiency was determined. The problems associated with measuring the concentration of contaminants in a car park are highlighted.
标题:THE PRESENT SITUATION OF THE ENERGY CONSUMPTION IN RESIDENCE IN THE CHANG JIANG RIVER BASIN IN CHINA
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内容:The authors of this paper investigate and survey the different kinds of residence in urban and rural areas in the Chang Jiang River Basin. Depending on the data obtained, some character of the envelope structure, thermal environment. Energy consumption and the knowledge of energy conservation are analyzed and discussed.
标题: BUILDING ENVELOPEN MOISTURE CONDENSATION FOLLOWING AN EUROPEAN STANDARD PROPOSAL
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内容: Object of this work is the thermal and moisture performance analysis of building exterior walls, according to the European Standard draft prEN ISO 13788:1997 prepared by Technical committee CEN TC89 . In order to establish design criteria and to evaluate the thermal and moisture behavior of building components , the physical model and the calculation methods are provided. In particular, the European Standard focuses on the two main reasons that cause moisture degradation in building envelopes: surface condensation and concealed condensation. The approach is based on the steady state diffusion theory and calculations are carried out on the steady state diffusion theory and calculations are carried out on monthly basis, into account internal moisture production rates and outdoor climatic conditions.
A user friendly software tool " TMCE (Thermal and Moisture Control for Envelops)" , developed in order to quickly and easily assess moisture and thermal behavior of building components, is here presented. The software , with graphical user interface, allows: i) to determine the minimum thermal resistance of a building component in order to avoid surface condensation, and ii) to check if concealed condensation occur in a multi-layer wall. In case of condensation occurrence during the winter months, the rate of condensed vapour is calculated, and the possibility that the moisture is completely removed during the warmer periods is evaluated. TMCE has been used to carry out sensitivity analysis on moisture and thermal characteristics of building components on varying input parameters such as outdoor climatic and indoor moisture production; relevant results are herein presented.
标题:EFFICIENT AND EFFECTIVE MECHANICAL VENTILATION
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内容:This paper describes the contents of two technical publications by the CIBSE Mechanical ventilation Task Group. The first, provides information on air leakage testing in order to produce airtight buildings for energy efficiency and better ventilation control. The second, describes the main factors associated with the design of efficient mechanical ventilation systems. Both form part of the Task Groups strategy, which is to promote energy efficient and effective ventilation design. The paper discusses the main features of the technical notes.
标题:TOWARD BETTER BUILDING ENERGY PERFORMANCE IN HONG KONG: DEMAND SIDE MANAGEMENT AND ENERGY PERFORMANCE INDICATOR
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内容:This paper discusses two important aspects in achieving better building energy performance, with particular reference to large air conditioned buildings in Hong Kong . The first one is the application of Demand Side Management (DSM) strategies in buildings in Hong Kong. The current status of electricity supply and barrier to applying DSM in buildings are reviewed, and the short-term actions in buildings DSM are suggested. The second is to establish suitable performance indicators for building energy consumption. The needs for better indicators of energy utilization performance in existing buildings. A new indicator for building air conditioning energy performance is proposed.
标题:INVESTIGATION ON COOLING LOAD COMPONETNT OF PV-WALLS
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内容:One of the advantages of photovoltaic (PV) integration in buildings is the cooling load reduction effect in summer. After the establishment of the building integrated photovoltaic system on the campus of the Hong Kong Polytechnic University , the heat transfer across the photovoltaic walls have been investigated theoretically and experimentally. This paper reports the preliminary investigation results. The simulation can determine the cooling load component due to the heat gain from PV claddings. Photovoltaic walls for three different locations ( Hong Kong , Shanghai and Beijing) are analyzed as case studies to calculate the cooling load component of a PV-wall. In comparison with the corresponding cooling load component for conventional building walls, the PV integration leads to a cooling load component reduction by 35%-50%. The cooling load reduction can be regarded as cost saving for the solar energy applications.
标题:CRAY INTERNAL FORECASING OF LOADS OF BUILDING HYGROTHEERMAL SYSTEM
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内容:This paper simply states conventional and special forecasting methods, and discusses the difference between two kinds of uncertain theories, that is , stochastic and gray system one. The uncertainty of the Building Hygrothermal system (BHS) is analyzed. BHS is regarded as a gray system. Gray prediction model, GM (1,1) , is depicted. A method, Upper-Lower Limitation Lines Method (ULLLM), based on gray predicting model and gray plane is proposed. Building loads for a certain example is predicted by using the above method. By inspecting, predicting values of a certain year just fall into predicting gray plane built by UDLLM is feasible and correct. The method is important to operation and management of air-condition equipment.
标题:AN ANALYSIS OF CONDUCTION & RADIATION THROUGH PERFORATED-BRICK WALL BY THE IRREVERSIBLE THE RMODYNAMICS
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内容:In this paper, the principles of Irreversible Thermodynamics are used to analyze heat transfer through perforated-brick wall. By the multiple linear regression of experimental data. The specialties of simultaneous conduction and radiation through perforated-brick wall are analyzed in this paper. It is a useful research on the application of the Irreversible Thermodynamics in the field of building thermal energy engineering.
标题:IMPACTS INTERIOR DECORATION ON THE ENERGY EFFICIENCY OF RESIDENTIAL BUILDINGS- A CASE STUDY IN BEIJING
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内容:This paper presents the study on how interior decoration influences the energy efficiency of residential buildings during the heating period. CFD technique has been employed to study 5 typical cased under Beijing climatic condition. Experimental data has been compared with the simulation results. Comparisons of thermal performance among the 5 studied cases have been carried out to identify the key relevant factors that contribute to the declination of the energy efficiency. The paper also highlights some criteria for interior decoration design that aims to obtain best global thermal performance.
标题:DETERMINING HEAT TRANSFER COEFFICIENT OF THE WALL SURFACE BY GENETIC ALGORITHM
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内容:The heat transfer coefficient of wall surface is one of the important parameters in building energy consumption analysis. In this paper two parameters were measured by data acquisition system including the dynamic heat flux of wall surface and the temperature difference between indoor air and wall surface. The sampling data was modeled by genetic algorithm and the calculating formula of the heat transfer coefficient is obtained finally. Study of the experimental and the predictive data verifies that the predictive result is satisfactory agreement with the measured heat flux. Therefore, genetic algorithm is an effective approach to procure heat transfer coefficient from dynamic experimental data of wall surface and possesses high enough accuracy.
标题:ENERGY CONSERVATION AND RETROFITTING POTENTIAL IN EMPORIUM BUILDINGS
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内容:This paper concludes the problems on operation and energy consumption of air-conditioning systems in emporium buildings on the basis of investigation and surveying materials, analyzed the causes of these problems, presents proposals on design and operation methods of air-conditioning systems of emporium buildings and gives some examples to state detailedly.
标题:PROSPECTS FOR THE HVAC INDUSTRY OF CHINA IN THE 21 ST CENTUDY
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内容: The paper predicts developing trends of HVAC industry of China in next century: (1) HVAC demands in residential, commercial and industrial building market; (2) change of energy structure. (3) environmental pressure and energy efficiency; (4) effective and healthy HVAC systems.
标题:AN OUTLOOK OF RESIDENTIAL ENERGY CONSUMPTION IN HONG KONG
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内容: The past energy consumption in the residential sector in Hong Kong has been analyzed and a simulation model to forecast the total energy consumption in the residential sector has been developed. The residential energy consumption is modeled as a function of households, income per household, energy price of a dominated energy source and weather indicator. Energy consumption is assumed to depend partly on the past level of energy consumption so that the effects of changing appliance ownership and technology development are accounted in the model. Due to rapid population growth and economy development in Hong Kong , the current energy demand in the residential sector has accounted for 1.09 MTOE. The demand will reach 1.45 MTOE at the year 2010, and increase of 34% in 12 years.
标题:PERFORMANCE PREDICTION OF A FLOOR HEATING SYSTEM USING BURIED ELECTRIC HEATING PANELS
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内容:This study examines the optimum design and control of a floor heating system using buried electric heating panels. The system makes a significant contribution to electric power load leveling bye the thermal storage using soil as storage medium. Also, it is a very economical system in Japan because it can use the nighttime power rate, which is discounted about a quarter of that during daytime.
The system performance and thermal environment in the building are strongly affected by various design conditions ( e.g., number of panels, depth of buried panels, condition of the thermal insulation surrounding the storage medium, control strategy, physical properties of the storage medium, etc,), so there are a number of problems that need to be solved or clarified to established the optimum design and control strategies.
In order to estimate the system performance and the storage effect accurately, it is necessary to estimate the thermal behavior of the system, not only in winter season but also in other seasons, because the soil has an extremely large thermal storage capacity. Furthermore, in the analysis procedures, the system operation and the thermal behavior of the building should be analyzed simultaneously.
In this study, a system simulation program was developed for this purpose and the system behavior was analyzed under several design conditions. In conclusion, it was clear that not less that 10 M2 floor in a building can be air-conditioned by one buried panel, which has 0.975 m2 area and 320W output, at depth of 0.1m below the slab. And then , the annual heat recovery rate was about 90%.
标题:PERFORMANCE OF A SOLAR ABSORPTION AIR CONDITIONING SYSTEM
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内容:This paper presents the simulation of a solar powered absorption air conditioning system with the absorption pair of lithium bromide and water. The system includes the following components; solar flat-plate collector, a lithium bromide-water absorption air conditioner ( with cooling tower), an auxiliary energy source, a partitioned hot water storage tank( in tow parts) and associated controls. The analysis indicates that it is preferable to utilize a partitioned water tank that the normal stratified water tank; because the cooling effect can be realized much earlier compared to the wholly stratified water storage tank. Also, the overall cooling efficiency( cooling load to total solar energy ratio) was found to be higher for partitioned storage air conditioning system
标题:RESIDENTIAL ENERGY CONSUMPTION IN CHINA: A LITERATURE STUDY
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内容:Over the last two decades in China, the mushrooming residential energy consumption has been developing an enormous stress on the national energy system and the global environment. Diversities of researches have been carried out to study the pertinent issues. This paper briefly introduces the residential development and its impacts on the national energy system, identifying the key issues that have been and are being studied. Finally, the problems and issues that are still being studied or need to be studied are introduced.
标题: STUDY ON SPECIFICATION OF RANDIANT FLOOR HEATING SYTEM
关键字:Numerical simulation, FEM(FEM), energy saving
内容:In this paper, mathematical model of low temperature radiant floor heating system (LFRS) is established for the process of heat transmission. Through numerical simulation, the temperature field is calculated by finite-element method(FEM). The thermal comfort and the effect of saving energy are analyzed. By the dynamic simulation for the real operation, it is shown that LRFS is in a higher sanitary condition and thermal comfort. Furthermore al kinds of energy sources are made available in this system. The result is of great importance for the design, construction and operation of this sort of system
标题:THE EXPERIMENTAL AND SIMULATION OF THE INFLUENCE OF A COOLED CEILING ON THE AIR TEMPERATURE DISTRIBUTION
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内容:Water-cooled ceiling panels are mostly used in office buildings for its better thermal comfort and energy conservation. The experiment without fan ventilation was made in a real-size office with a water-cooled ceiling panel, which is built up aluminum panel and polyethylene pipe into. One aim of experiment was to find the vertical distribution of the air temperature. It is found that the vertical gradient of air temperature within 0.2m from the panel and 0.5m form floor surface varied much quickly, and the gradient in other zone is close to zone. In order to analyze the thermal performance of this system, a model was developed and validated against exiting experimental data. A reasonable agreement shows that this model is possible to simulate the cooled ceiling systems.
标题:EXPERIMENTAL STUDY ON REDUCING ROOM TEMPERATURE BY SOLAR COOLING
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内容:As one kind of new energy, solar energy will be used widely. In this paper, reducing room temperature by solar cooling is verified by experimental study on buildings. The method is simply and practicable and it can reduce the maximum room temperature by two centigrade.
标题:SUSTAINABLE AIR-CONDITIONING IN HIGH-DENSITY RESIDENTIAL BUILDINGS
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内容:This paper introduced the state of the arts on air conditioning of residential building in China, and analyzed the exiting problem and possible solution. An air conditioning system combining central cooling water system and individual room air conditioner is proposed as a new type of sustainable air conditioning system for high-density residential buildings.
标题:EXAMINATION OF THE EFFECT OF ENERGY CONSERVATION BY INTERMITTENTLY STOPPING AIR CONDITIONING
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内容:The purpose of this study is to investigate whether intermittently stopping air conditioning can decrease the energy consumption. Although it may have certain influence on indoor air quality , to stop air conditioning intermittently is one of the most simple and effective methods for energy conservation without adding new facilities. It is not obvious whether the energy consumption is reduced in terms of the total amount, because the cooling loads during resuming of air conditioning after a short stop is more than those of continuous air conditioning .
It is insufficient to examine case of intermittently stopped air conditioning in a short period because general load calculation program in Japan is for one-hour interval . Therefore we have developed the computer simulation program, in order to predict indoor air temperature and cooling loads for one-minute interval. Cooling load calculations are carried out by thermal response factor method.
This paper describes the calculation method of indoor air temperature and cooling loads for one-minute interval. The simulation results were verified by comparison with measured indoor air temperature and cooling loads. It was made clear that there was relationship between the simulation results and the measured data. This program was used to examine whether the total cooling loads were reduced in intermittently stopped air conditioning.
标题:MOISTURE CONTROL AND ENERGY CONSERVATION IN EXISTING TERTLARY LIBRARIES
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By nature books will deteriorate with time. In an environment with higher temperatures and relative humidities the deterioration process can be accelerated . For example mould will easily grow at a high relative humidity condition, whereas very low humidity will make stationery material brittle. Therefore, outside air needs to be handled by a dehumidification or a humidification processing before entering the building. The climate in New Zealand is humid. Relative humidity in large cities, such as Wellington , Christchurch and Invercargill can be higher than 85%, whilst in Auckland it can be 100%. Even in February , for the Auckland location. Which has the lowest monthly average relative humidity(rh), rh is at 73%. The control of moisture is a critical problem for library storage. Unfortunately many tertiary libraries in this country were short of money when they were built, co energy systems which were chosen then may not be adequate for this purpose.
The adequate condition for book storage, according to current design options, is at a range of relative humidity 50%± 10% and temperature of 20±2℃. For full control of indoor rh in this range, in Auckland , a HVAC systems which were chosen then may not be adequate for this purpose.
The adequate condition for book storage, according to current design options, is at a range of relative humidity 50%±10% and temperature of 20±2℃. For full control of indoor rh in this range, in Auckland, a HVCR system such as the Dual Duct Fan System (DDS of DDE-2) is needed. With this system, the energy consumption will be doubled compared with a Heating and Ventilating (only) System (HVSYS of DOE-2). By extending the relative humidity range to 30-75%, the conditions suggested by some professionals as acceptable for material storage , energy consumption will be significantly reduced. In analysis of energy perfrmance and conservation, this paper uses a generalised DOE-2 simulation model to compare energy consumption with the two different systems and discusses the relevant problems.
标题:DEMAND CONTROL FOR FRESH AIR VENTILATION IN COMMERCIAL BUILDING
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Source control and adequate supply of outdoor air are two strategies that used to achieve good Indoor Air Quality (IAQ). The design fresh air supply flowrate depends on the peak occupancy. In an office with varying occupancy or large infiltration, it offers an opportunity for energy conservation by varying the first air flow rate on demand.
In conventional Demand Controlled Ventilation (DCV), the sole goal is to reduce energy consumption on maintaining a space carbon dioxide (CO2) set point. Other indoor comfort conditions are not taken into consideration. In this research, a Demand Controlled Ventilation (DCV) system was implemented in an office to evaluate the potential saving for the whole building. At the same time , a thermal comfort study was conducted to ensure that the thermal comfort was not jeopardised.
The office was served by a variable air volume (VAV) system. The fresh air flow rate was supplied into the air handling unit (AHU) room from a central fresh air supply system. There was no control on the fresh air flow rate into the AHU room other than a balanced volume control damper (VCD). A Direct Digital Control system was designed to regulate the fresh air flow rate. The balanced VCD was regulated by an electric actuator to vary the fresh air flow rate. The control of the damper was effected by an algorithm by an error function of the space CO2 and the designed set point at 1000 ppm.
To ensure the DCV did not induce an adverse thermal environment, a thermal comfort survey was conducted. The result was positive. The CO2 in both the office space and the return path inside the air handling unit room were recorded. The air tightness of the building was estimated from the metabolic carbon dioxide decay when everybody left the office. The air change rate of the office at any time was estimated by discretising the Zone CO2 equation. The energy saving was estimated by comparing the fan power and cooling energy required in the full supply system.
A ventilation model based on the metabolic carbon dioxide profile was used to evaluate the fresh air supply flow rat. The building air tightness was also estimated from the metabolic carbon dioxide decay at night time when the system was switched off. It was estimated that with a DCV , this office had a potential energy saving of 41$. Assuming the rate of fresh fir flow reduced at the same proportion in other offices in the same building ,it is estimated that estimated that 3.5 millions of energy cost can be saved.
标题:ASSESSING OUTDOOR AIR SUPPLY AND ITS ENERGY IMPLICATION IN AN OCCUPIED HOTER
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内容: This paper reports an investigation of the outdoor air supply in spaces of a hotel under occupied conditions. It is intended to assess the impact of outdoor air supply on energy use whilst satisfying the ventilation requirement using a hotel as an example. Methods of identifying the available ventilation rates and determining the energy consumption were addressed. Available ventilation rates were based on actual occupancy and recommendations of ASHRAE 62. Energy consumption for cooling and ventilation was determined using the building energy programs HTB2 and BECON. Energy signatures and ventilation operating performance lines were proposed as ventilation performance indicators and diagnostic tools for identifying corrective measures. The amount of available and required ventilation in the hotel being studied and its implication on energy consumption, were quantified and discussed.
标题:RECOVER WASTE HEAT BY TWO STAGE LITHIUM BROMIDE ABSORPTION HEAT PUMP
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内容:The energy problem is one that every country is paying much more attention to . Now saving energy has becoming more and more important. Some industrial installs release some gas, steam or water that contain some waste heat. If they are released to the nature world , they will make thermal pollution to be environment, which we live in. The two stage lithium bromide absorption heat pump is one kind of absorption heat transformer, which can raise the temperature of the waste heat. The two stage lithium bromide absorption heat pump can be powered by the 70-100℃waste heat, and produce 130-140℃ hot water or steam. It the paper, the two stage lithium bromide absorption heat pump is introduced, its design, performance and efficiency of the heat pump are analyzed , at the end of the paper some conclusions are given out .
标题:SIMPLE COOLING PLANT MODEL VERIFICATION AND ITS APPLICATION ON POWER DEMAND PREDICTION
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In this paper the simple model of a cooling plant consisting of a chiller with water-cooled condenser connected to a cooling tower is tuned on manufacturers data. The model is then used to predict overall electrical power consumption for different outside wet bulb temperatures. Based on simulation results simple low of power consumption as a function of outside wet bulb temperature and cooling demand is introduced. The simulation of the cooling plant is done in EES (Klein, 1995)
标题:BREF DISCUSSION ON THE HOST IMPORTANT MEANS TO ENERGY -SAVING DESIGN FOR HIGH BUILDINGS
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内容:This paper makes a deep research on the energy -saving issue in designing the air conditioning for the travel hotel, high-quality office buildings, senior restaurant and luxurious apartments. It also put forwards the reasonable plan of architecture building is the host means of energy saving , and the layout design of air-conditioning refrigeration and the selection of equipment are critical to energy saving for building. How to research and develop utilization of the new energy is the important factors for energy saving. Especially point out energy saving is the deep-concerned central discussion theme.
标题:THERMAL POWER LOOP HEAT EXCHANGERS FOR HEAT RECOVERY AND THERMAL CONTROL IN AIR-CONDITIONING SYSTEMS
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Indoor air quality and energy saving in air-conditioning systems have been taken seriously. Suitable temperature and relative humidity of supply air are important aspects of good indoor air quality. Thermal Power Loop (TPL) heat exchanger is very effective device for transmitting heat at high rates over considerable distances with extremely small temperature drops, reversibility used in air-conditioning systems, not only for heat recovery, but also for thermal control. This paper presents the application of TPL heat recovery, but also for thermal control. This paper presents the application of TPL heat exchangers to heat recovery, temperature and humidity control in air conditioning systems . The study involves analytical modeling , thermal control and simulation of heat recovery system. TPL heat transfer principles and capillary limitation are analyzed . System model of heat recovery is established by analyzing the heat flow and using energy conservation principle. A typical single -zone air-conditioning system with heat flow and using energy conservation principle. A typical single-zone air-conditioning system with heat exchanger is simulated. The temperature and relative humidity control of supply air by thermal control of TPL heat exchanger is conceptual designed . It is observed that this type of heat exchanger used in heat recovery system has more advantages than the conventional reheat coils , and can result in energy saving and enhancing the cooling capability of cooling coils.
标题:THE TEMPERATURE DISTRIBUTION OF DUST REMOVING ANDHEAT EXCHANGING IN ELECTROSTATC AND HEAT TUBE FIELD
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内容:There are much more flue dust and remaining heat energy in exhausted flue gas of industrial fumaces flue pipe. The flue gas will result in industrial dust pollution. The remaining heat energy will make great energy lose. When the dust is removed, and the waste heat is recovered, we can protect environment and save more energy. So, many developed countries in the world are attaching importance to these problems. The methods are different. They can be solved separately or simultaneously. Especially , solving it in the meantime, if joint well, will be better.
On the basis of finished experimental researched before . Now , we put a special heat tube with fins in a field of electrostatic precipitator ,and make a combination of them. It comprises an electrostatic , heat tube, heat exchanging dust remover.
It makes a joint force of static electricity, temperature difference and air dynamics. It can produce good results in recovering and removing.
The paper analyses the temperature field of a single heat tube and also lines of them. It comprises an electrostatic field by the theory of forced convection of exchanger of heat. There paper concludes that how to put them and what distance will be better to combine them together , it will be better for practice using of the equipment.
标题:EXPERIMENTAL RESEARCH ON NATURAL CONVECTION HEAT TRASFER PERFORMANCES OF FINNED-TUBE RADIATORS
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Based on finned-tube room radiators , experimentally showed that for two-tube vertical arrangement, heat transfer coefficient of the lower tube is badly degraded by the preheating from lower tubes. Maximum total heat transfer at upper tubes is badly degraded by the preheating from lower tubes. Maximum total heat transfer rate occurs at minimum channel width. Heat transfer at upper turbes is significantly enhanced when four tubes aer horizontally staggered.
标题:INFLUENCE OF SUPPLY AND RETURN WATER TEMPERATURES ON THE ENERGY GONSUMPTION OF A DISTRICT COOLING SYSTEM
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In a district heating and cooling system, for example the Beijing combined heating. Cooling and power (CHCP) system studied here, high temperature water generated by cogeneration plants circulates through a network between the plants and the heating substations. In heating substations, high temperature supply water from the network drives absorption chillers for air-conditioning in the summer, satisfies space heating demands in the winter and provides domestic hot water using heat exchangers throughout the winter and provides domestic hot water using heat exchangers throughout the year. This paper studies the significant effect of the parameters, i.e. the supply and return water temperature in the network ,on the CHCP system energy consumption for cooling and for domestic hot water.
标题:A study of New PCM: Trimethylolethane tetrahydrate and its Mixtures having phase change temperature between 13℃ and 30℃
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内容:We have been studying new organic hydrate phase change materials. It is well known that trimethylolehane (TME) has a soild-soild phase transition temperature of 81℃. Also,it generages a tetrahydrate compound. We found that its phase transition temperature could be controlled between 13℃ and 30℃ by adding small amounts of urea. This temperature s very suitable for use in air conditioning systems, passive solar systems, etc. We investigated its thermal properties and thermaldurabilities using a differential scanning calorimeter (DSC) and liquid chromatography (HPLC).
The melting point of PCM30 (the weight ratio was optimized on the basis of TME tetrahydrate) was 29.8℃ ,but phase-separation behavior was observed during heating-cooling cycles. The phase transition temperature of PCM30 decreased with the increasing addition of urea, and the final phase transition temperature was 13℃(PCM13).The durabilities of PCM30 and PCM13 were evaluated in a stainless steel (USU) sealed container. PCM30 was very stable in spite of its exposure to high temperature. On the other hand, PCM13 decomposed at the higher temperatures and the urea component changed to ammonia gas. However, at low temperatures of less than 25℃, the durability of PCM13 determined by kinetic calculations in the SUS sealed container was high enough for use as a latent heat storage material, even when it it is used for a long time. We found that the TME/water/urea mixture has a hign potential as a latent heat storage material when used for air conditioning systems and so on.
标题:A Research on the Performance Field Testing of Air-Conditioning Ice -Storage Systems
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This paper proposes a field test method to evaluate the performance of air-conditioning cool storage systems. In this method, the storage capacity, storage efficiency and cooling capacity under actual application conditions are tested and evaluated. This method has three characteristics. Firstly , it is a relatively simple test. Secondly, the performance is measured under the conditions of actual applications. Lastly, the basic functions of energy transfer are measured, and therefore , applicable to different ice storage systems. The applications and benefits of such a test method are discussed . This paper describes the items of testing, Instrumentation, measurements, an uncertainty analysis and the some results of six field tests.
标题:DESIGN CONDISERATIONS FOR FULL-SCALE STRATIFIED CHILLED WATER STORAGE TANKS WITH RADLAL PARALLES PLATE DIFFUSERS
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内容:Chilled water thermal storage is used extensively in the United States for load management and peak electric demand reduction in large chilled water systems. The great majority of storage vessels are naturally stratified tanks, most of which are vertical cylinders. Design guidelines for stratified tanks are based upon an incomplete parameterization that does not account explicitly for tank geomery and that relies upon limited experimental measurements in tanks that are nearly two orders of magnitude smaller than typical full-scale tanks. Consequently, it is not surprising that observed performance of full-scale systems does not accord well with this design theory. This paper considers thermal performance prediction for the purpose of designing cylindrical naturally stratified tanks with radial parallel plate diffusers. The existing design methodology for stratified chilled water storage tanks is reviewed and critiqued in light of field data gathered from full-scale tanks. An improved method is developed through three steps. First, a complete set of parameters is generated by rigorous dimensional analysis. Next, a 2k factorial experiment is conducted on thermal performance results derived from charging simulations performed with a computational fluid dynamic (CFD) model validated by field data. Statistical analysis of these results identifies parameters of first order significance: the inlet Richardson number, the ratio of diffuser radius to tank radius ,and the ratio of diffuser radius to diffuser inlet height. The inlet Reynolds number is found not to have significant influence within the parameter ranges investigated. Finally, linear regression is used to develop simple thermal performance predictors as functions of significant parameters. The use of the resulting relations in design is discussed and illustrated. These new relationships provide a quantitative basis for optimizing diffuser design and take into account tank as well as diffuser and flow parameters.
标题:Development of new heating system using PCM having phase change temperature of 52℃
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内容:We have developed a new room heating air conditioning system using phase change material having phase change temperature of 47℃ and 55℃. However, in the case of PCM of 47℃,40℃to 42℃ of water can be derived during heat discharging, and so it is unavoidable to operate both the heat storage tank and the heat pump, And in the case of PCM of 55℃, it is very difficult to use ordinary heat pump, because inlet water temperature of heat storage tank is necessary more than 65℃ for heat charging.
The purpose of thd development of PCM of 52℃ which consists of an acetic acid soda. And , after the completion of PCM, we investigated thermal performance of the latent heat storage tank of 2m3,which is fully filled with encapsulated PCM of 52℃.
As the results, it is possible to be charged by the water of 60-62℃because the heat pump is available. The discharging heat capacity until output water temperature 47℃ of the heat storage tank is almost equal to the existing heat storage tank using PCM of 47℃or 55℃.
标题:ENERGY SAVINGS IN ICE STORAGE SYSTEM BY DESIGN
关键字:Ice Storage,Optimal Design ,Simulation
内容:Three ways to improve ice storage of chiller and ice bank in series are analyzed using a system simulation program known as TSTORSP:(1)secondary pump; (2) self-regulated valve; (3) variable speed pump. It is shown that a lot of energy canbe saved by using secondary pump and self-regulated valve if constant speed pumps are used. If variable speed pump can be used, there are further more energy saved by desining proper ice storage system.
标题:LATENT HEAT THERMAL ENERGY STORAGE SYSTEM COMBINED WITH NIGHT VENTILATION IN SUMMER
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内容:A kind of new energy efficiency building system-LHTES (latent heat thermal energy storage) system combined with nigh ventilation is proposed. Its advantages, operating , a kind of LHTES system design built in the space between a hung ceiling and the floor above it applied in a typical residence is described. The performance of cool charging and discharging is simulated and its economics analysis is undergone. The results show that this system can improve indoor thermal comfort level during summer and intermediate seasons for the rooms without air-conditioning systems or can save much energy for the rooms with air-conditionings system.
标题:EXPERIMENTAL RESEARCHES ON DYNAMIC ICE-MAKING BY SUPERCOOLING WATER
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内容:Two factors to lead to icing in heat exchanger in dynamic ice-making system were investigated: supercooled degree of inner surface of tube wall and ice crystals entering into heat exchanger. Supercooled degrees of inner surface of tube wall could be divided into three zones according to possibility to lead to icing in the tube:stable zone , less stable zone , unstable zone. Dividing line of stable and less stable was not markedly related to Renolds number of water in tube when Renolds number in range of 0-9200. Ice crystals entering into heat exchanger was very likely to lead to icing although responding time was stochastically distributed.
Keys to keep stable running of dynamic ice-making by supercooling water were put forward: to keep temperature of outer surface of tube wall above certain value, to eliminate fully supercooling of water in ice tank and to eliminate completely ice crystals carried by water from ice tank before entering into heat exchanger. Dynamic ice -making apparatus by supercooling water was set up. It ran stable with temperature of water at inlet of heat exchanger of higher than 0.45℃ and temperature decline of water through heat exchanger of about 1℃.
标题:THEORETICAL ANALYSIS OF DESING OF THE SUB-COOLING ICE-STORAGE SYSTEM
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内容:As a new kind of ice-storage system, a sub-cooling ice-storage system utilizes the subcooler to improve the evaporating temperature of a refrigerator when simulation result shows that COP of a refrigerator in such a system is about 13% higher than of a conventional static ice-storage system . Because the initial cost of the former is higher than that of the latter , an optimal design is necessary to minimize the overall cost . This paper analyzes some factors affecting the performance of the system. Based on that, some suggestions for the design of such systems are presented,
标题:A RESEARCH ON "WARMICE" COOL STORAGE TECHNOLOGY
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内容:"Warm ice " was first named in literature in 1990, to denote those clathrate hydrates formed by refrigerants for cool storage applications. A large variety of refrigerants can initiate water to from "warm ice" in range of 5-17℃ with large formation heat (320-430kJ/kg). Recently , the“warm ice ”cool storage technology has progressed due to the breakthrough in appropriate hydrate formers and efficient hydrate formation processes. One of the major progress in this new technology is the use of blends of refrigerants ,which are environmental friendly, and some additives to form mixed hydrates which have better thermodynamic and hydrate-formation properties and low inventory of refrigerant. The other progress is the development of high efficient " warm ice" storage facilities. In this paper, the experimental results for the phase-equilibrium and hydrate-formation properties of several warm ices formed by blends of new refrigerants and an innovative high-efficient "warm ice" (clathrate hydrate) storage equipment are reported. The experiments on the performance of the developed storage facility are presented and the test results are discussed. For application of the new "warm ice" storage system in the practical air conditioning engineering, we have proposed a serial partial-load cool storage arrangement with the chiller located downstream. It is shown that the proposed application mode can meet the engineering requirements for air conditioning standards and is more economic comparing with ordinary ice-storage sir conditioning system,
标题:THE WORLDWIDE DEVELOPING ORIENTATION AND TREND OF ICE -STORAGE AIR-CONDITIONING IN 21st CENTURY
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内容:Based on long-term research of ice-storage air-conditioning technology, the paper shows that the ice-storage technology has prosperous future in modern refrigerating and air-conditioning systems. It also points out that the ice-storage cooling station with low-temperature blowing system will be one of the critical center systems in 21st century. In addition, it shows that the ice -storage air -conditioning systems can produce large social and economic efficiency and should go towards large-and-medium-scale central cooling by regions ,of mini-seriate, by -floors and of towards large-and-medium-scale central cooling by regions , of mini-seriate, by-floors and of family-style.
标题:ECONOMIC ANALYSIS OF ICE-COOLING STORAGE AIR CONDITIONING SYSTEMS FOR THREE KINDS OF COOLING LOAD MODELS
关键字:Ice-cooling storage, air-conditioning , capital investment , operation cost. Cooling load distribution
内容:This article makes comprehensive economic analysis of all kinds of ice-cooling storage air conditioning systems. From the perspective of the ice-cooling storage air conditioning load, it generalizes three possibilities out of the buildings of various syles, dimensions and uses under all kinds of climate conditions. It also makes fifteen technically possible design programs for the various situations above. Finally, with considering the electric charge policies, it comes to the conclusion on the selections of those design programs.
标题:DESIGN OF NATURAL VENTILATION AND OUTDOOR COMFORT BY A TEAM OF ARCHITECTS AND ENGINEERS WITH THE CFD GECHNIQUE
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内容:To design a comfortable indoor and outdoor environment requires detailed information of airflow in and around buildings .The existing simplified analyses and empirical approaches are inadequate to obtain the needed information. This paper demonstrates how the computational fluid dynamics (CFD) technique can be used by engineers to calculate the airflow distributions in and around a building. Architects can use the airflow distributions to modify their design. This design procedure shows a model of how the architects and engineers can work together to design a sustainable building.
标题:VALIDATION OF CFD MODEL FOR RESEARCHINTO APPLICATION OF DISPLACEMENT VENTILATION TO HONG KONG BUILDINGS
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内容:Displacement ventilation may provide better indoor air quality and save energy. There is a question of suitability of this technology in HK buildings with higher cooling loads. Two main approaches available to answer the question are experimental investigation and computer simulation. CFD technique is a powerful tool to solve indoor environment problems. A commercial CFD code was used for the computations. The results obtained by the CFD simulation are more informative and comprehensive than all the measured data. The CFD program will be also used to expand the experimental results to an appropriate range of building applications
(i. e., room configuration and height, heat load type and distribution.) A k-εmodel was employed as an alternative tool for the experiment in a full-scale indoor space. The use of turbulence leads to uncertainties in the computed results because the models are not universal. Therefore, it is essential to validate the CFD program by experimental data. Validation was conducted by comparing the flow patterns vertical profiles of temperature, concentration, velocity, and turbulence intensity between measurement and computation for an individual office, a cubicle office, and a quarter of a classroom. The computed air temperature and velocity agree well with the measured data. The agreement is less satisfactory between the computed and measured temperatures in the lower part of the office. The CFD program therefore can be used for simulation of airflow in a room with displacement ventilation.
标题:A CFD Study for Airflow Distributions at Floor Level in A Slot -Outlet and Slot -Inlet Ventilated Room
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内容:In this paper, airflow distribution characteristics at floor level in a slot-outlet and slot-inlet ventilated (SOSIV) room was compared between CFD simulation and available measurement results (Wang et al 1996). With two different outlet/inlet location ,6 levels of diffuser height and supply velocities , total 48 cases were simulated under isothermal and nonisothermal conditions. For both the vertical velocity profile and horizontal velocity distribution at floor level, the simulation results were shown to be in good agreement with available experimental data. However, calculated maximum floor-level velocities were 5% and 10% less than the measurement data for isothermal cases and nonisothermal cases, respectively. This could be result of the maximum velocities often happened near the floor and the stand are k-εmodel is poor to predict airflow in this area.
标题:NATURAL VENTILATION SYSTEM DESIGN FOR RALL WAY DEPOT USING CFD ZONE MODEL
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内容:Over Arup & Partners Hong Kong Ltd. was commissioned to carry out the engineering design of a new railway depot. As part of the design, a study was carried out to investigate the ventilation requirements and the feasibility of adopting natural ventilation scheme for the stabling area of the depot.
In this paper; the performance of different natural ventilation schemes for the Depot stabling area are presented and resultant environmental conditions are described including fire emergency scenario.
标题:COMPUTER DESIGN TOOL FOR NON-UNIFORM INDOOR THERMAL ENVIRONMENT PROBLEMS
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内容:Design of a thermally comfortable indoor environment requires detailed information about distribution of air velocity, air temperature, relative humidity, and mean radiant temperature and about heating /cooling load in a space. This research has developed a coupled airflow-and-energy simulation program to calculate simultaneously the distributions of indoor airflow and thermal comfort and heating/cooling load. The coupled program can take the non-uniform distributions of indoor airflow and heating/cooling load into account. The program can also provide thermal and fluid boundary conditions normally needed for room airflow calculation .This paper demonstrates the program capacity by applying the program to study the thermal environment in an atrium.
标题:SIMULATION OF WIND DRIVEN VENTILATIVE COOLING IN AN APARTMENT BUILDING IN BEIJING AND SHANGHAI
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内容:This paper presents a performance evaluation of two passive cooling strategies, daytime ventilation and night cooling, for a generic ,six -story suburban apartment in beijing and shanghai . The investigation uses a coupled transient simulation approach to model heat transfer and airflow in the apartments. Wind driven ventilation is simulated using computational fluid dynamics (CFD). Occupant thermal comfort is accessed with Fangers comfort model .The results show that night cooling is superior to daytime ventilation. Night cooling may replace air - conditioning systems for a significant part of the cooling season in Beijing, but with a high condensation risk. For Shanghai, neither of the two passive cooling strategies can be considered successful.
标题:PREDICATION OF THE AIRFLOW IN MULTI -ZONE BUILDINGS WITH NATURAL VENTILATION
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内容:The use of natural ventilation of modern building design is becoming increasingly prevalent in low energy buildings throughout the world. However, it is the difficulty in predicting the efficiency of natural ventilation prevents it to be used widely in multi-zone building design, There are two main kinds of methods, network method and CFD method. Both have their own advantage of both CFD and network methods was developed to predict the efficiency of natural ventilation in multi 7000 m2 floor area. The result shows that the net-field method is an effective method to deal with multi-zone buildings, because it takes an acceptable calculation time to get a relative exact result.
标题:A NEW METHOD FOR NUMERICAL ANALYSIS OF EXTERNAL AIR FLOW AROUND BUILDINGS
关键字:TSM CFD Numerical simulation wind effect
内容:In this paper, a new method called TSM (Two Step Method ) was presented to analyze external air movement around buildings .In TSM, the computational process is divided into two steps .In the first order , the computational domain may be much larger than the area we concern and big grids will be used . Besides, the concept of gradient wind was introduced to make inflow boundary conditions closer to actual case. In the second order, the computational domain was diminished to the area we concern, Grids will be redefined in detail. Boundary conditions come from the rough results of the first order. This process can be repeated so as to get satisfactory results .TSM provides an opportunity to solve the problem above in a sense. As an example ,the air movement around a villa cluster was given in the paper as well
标题:METHOD OF VENTILATING DESIGN FOR HIGH SPEED TRAIN
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内容:For the characteristic of high closing in compartments of high speed train, the ventilating design should ensure passengers safety and comfort. Since the traditional method of temperature and velocity distribution depending on free jet experimental equations ignores the effects of push pull flow and obstacles, the ventilating design mainly depends on modeling experiments. By regarding the push -pull flow and the shape of compartment and the seats as an integer, the method in this paper directly simulates temperature and velocity distribution to ensured the demands of comfortable air conditioning ,in the meantime ,it can conveniently obtain feeding velocity and feeding temperature difference .This method is not only applied to ventilating design of high speed train but also applied in ventilating design of general manned train and of aircrafts cabin.
标题:AN EFFICIENT EXPERIMENTAL PROCEDURE FOR SINGLE SIDED NATURAL VENTILATION
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内容:Single sided natural ventilation occurs when there is one or more openings on one exterior wall of a building, Wind produces the inconstant and heterogeneous air velocity distribution through an exterior opening due to its uncontrollable feature . Consequently, high accurate measurements at a great number of points are required in order to predict the air velocity at the opening successfully. This, as a result, makes this kind of experiment difficult and very expensive to perform .In order to solve this problem, A new experimental procedure was developed to offer a simple, convenient, accurate and inexpensive experiment method.
标题:SOME PROBLEMS ON NET METHOD FOR NATURAL VENTILATION PREDICTION
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内容:This paper discusses that how much the indoor-air temperature gradient affects the air exchange rate of naturally ventilated building, and analyzed the indoor air flow path resistance for natural ventilation of single room. This article put the correction to the application in simplified net iteration calculating method to predict the natural ventilation of one multi-zone building, and provided special experiment data to prove its accuracy.
标题:DISCUSSION ON SOME CONCEPTS OF MULTI -FIELD IN NUMERICAL SIMULATION
关键字:the multi-field coupling, the coupling of turbulence fluctuating variable, the coupling of flowing averaged variable
内容:There are coupling phenomenon which are correlation of momentum, energy and mass transfer in field of flows, heat transfer, mass transfer and combustion. The coupling which may is blended in terms of fluctuating correlation of turbulence and flowing averaged variable terms is showed up based on higher -order fluctuating correlation of turbulence and Reynolds-averaged equations in this paper .Concepts of coupling of turbulence fluctuating variable and coupling of flowing averaged variable are proposed also . The coupling phenomenon that is correlation of momentum and energy and mass transfer is discussed in detail with coupling of flowing averaged variable by way of turbulence models or closure statistical moment equations of Reynolds-averaged equations, which is pointed out. In this paper, the concept of multi-phase coupling and solved methods of coupling problems is introduced also.
标题:THEORETICAL ANALYSIS AND EXPERIMENT OF AIR INFILTRATION OF A NATURAL VENTILATED BUILDING
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内容:Air infiltration caused by natural ventilation if analyzed in this paper with focus on the synthetic effect of thermal pressure, wind pressure and diffusion .A series of tests were made in an office building to study the relationship of above three factors effecting air infiltration. Formulas of air infiltration prediction had been derived based on both theoretical analysis and experimental data. The actions of the factors effecting air infiltration rate were discussed.
标题:CFD APPLICATION IN THE DESING OF A THERMAL STORAGE WATER TANK
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内容:In this research, a typical high Reynolds-number type k-epsilon model was applied to simulate the flow physics and temperature behaviors in a temperature -stratified thermal storage water tank .To obtain the temperature distribution for all thermal storage process, present numerical analysis treated the unsteady flow during entire thermal storage period (10 hours) in all water tanks . Results showed that properly located flow regulation panels can significantly enhance temperature stratification in the thermal storage water tank .The stratified temperature thus maintained the optimal temperature difference for chillers operation and reduced its operation time for a certain amount of stored thermal energy. It can also be reasoned out that the stratified temperature provides better outlet water temperature during thermal recovery process. Owing to the popularity of the present turbulence model and reasonable calculation load, it can be concluded that present CFD technique is effective in evaluation of the design plans for thermal storage water tanks.
标题:TREATING FRESH AIR Options and Uses
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内容:In this paper we will study the equipments /technologies available to treat fresh air.
标题:DEVELOPING A DECOUPLED COOLING AND DEHUMIDIFICATION AIR-CONDITIONING SYSTEM
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内容:Recent advances in radiant cooling and desiccant dehumidification offer the possibility of independent temperature and humidity control in general air-conditioning applications. Chilled -ceiling systems are being applied in European countries as alternative air quality and thermal comfort by combining chilled-ceiling with displacement ventilation design. However, the system also offers many energy saving possibilities including reduced fan energy and increased opportunities for free evaporative of sea-water cooling. It is significant to investigate the potentials and limitations of the system application in hot and humid climates. This paper reviews the system applications in European countries and discusses some developmental system configurations that are conceived for hot and humid climates .In particular , some related system design concepts that will have drastic impacts on HVAC design will be discussed. System energy and space thermal comfort analysis tool development is needed to evaluate the system.
标题:EXPERIMENTAL INVESTIGATION OF ABSORPTIVE AND RGENERATIVE CHARA CTERISTICS OF A KIND OF NEW POLYMER GEL
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内容:This paper describes absorption and regenerative characteristics of super-polymer gel, which absorbed aqueous solution of calcium chloride. It is expected that the gel could be used for a dehumidification material for humidity control and separations techniques .Gel which absorbed calcium chloride solution of 10 to 40 mass % were tested .An equilibrium of the calcium chloride solution in the gel was obtained .Also , a regeneration test of the gel was carried .
标题:UNDERFLOOR AIR -CONDITIONING SYSTEM -THE TOTAL SOLUTION TO FLEXIBILITY?
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内容:In the paper, ceiling supply type and different configurations of underfloor air -conditioning systems are first briefly described, Without going into the engineering computational analysis, the various fundamental key issues such as air distribution ,flexibility ,air leakage ,
condensation ,life cycle costing ,floor height ,fire protection ,sick building syndrome ,ect .are qualitatively and pragmatically outlined .The implications of these factors on system selection are also reviewed.
标题:PERFORMANNCE ANALYSIS OF A MEMBRANE-BASED HUMIDITY PUMP
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内容:Moisture is usually transported form a fluid of high humidity to a fluid of relatively low humidity through a membrane. Membrane-based humidity pump works in another way: moisture is transported from a dryer air stream to a humid air stream under the driving force of thermal gradients in membrane. With humidity pump, a continuous air dehumidification can be realized by the utilization of low-grade waste heat .In this article, through finite difference simulations of the coupled heat and mass transfer in the unit, the performance of a membrane-based humidity pump is analyzed, Three kinds of membrane material are considered and compared . The effects of various thermodynamic and dynamic parameters of membrane on the performance of humidity pump are discussed. It is found that even though the operational parameters can be optimized to enhance thermal -osmosis rate of water vapor, the key role is played by the humidity pump factor.
标题:FEASIBILITY STUDY OF DESICCANT COOLING IN COMBINED HEATING ,
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内容:Based on system thermal COP and Cooling Capacity (CC) analysis, simulation work is carried out for possible application of solid desiccant cooing system in combined heating, cooling and power system (CHCP). With varied environmental air condition and supplied heat source temperature, the performances of high efficiency desiccant cooling system are calculated compared with traditional absorption cooling unit which is mostly applied in CHCP system currently. The results show it is possible and better for such a system to be used in CHCP system under moderate humid climate.
标题:FIXED-AREA EXPANSION EDVICES:A CRITICAL REVIEW
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内容:Fixed -area expansion devices are widely used in refrigerators air-conditioners, and heat pumps of up to 3.5kW capacity with variable operating conditions. A fixed -area expansion device falls into one of the three categories: an orifice, a short tube, and a capillary tube. The earliest studies on orifices began in 1900s,with the interest in metering fluid flow rate .The research on capillary tubes began to be active in 1940s.Shine then, the study of fixed-area expansion devices has been one of main activities in refrigerating. With the increasing need to replace the ozone-depleting CFC and HCFC refrigerants , refrigerators ,air-conditioners ,and heat pump system have to be redesigned to accommodate new replacement refrigerants so that research activities in fixed-area expansion devices have been intensified since early 1980s . This paper gives a detailed review of the literature on fixed -area expansion devices. The main topics include the mass flow rate through orifices, the mass flow rate through short tubes, rating capillary tubes, metastable flow, the friction factor and friction pressure drop, and mathematical solution of fixed-area expansion device.
标题:THERAL COMFORT CONTROL STUDY BY CFD
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内容:This article studies the thermal comfort control strategy of an indoor environment by computational fluid dynamics (CFD) software. It intends to show the capabilities of the CFD in modeling and predicting the room air dynamics. A room model with an exposed wall has been built to simulate the temperature distribtions under different load conditions. The comfort is measured by a combination of the air temperature, radiant temperature and air velocity . The system controls the comfort of the environment by monitoring the wall temperature and the exhaust air temperature and it is able to provide a stable comport environment to the occupants.
标题:FAST ROTARY DIRT REMOVER IN AIR CONDITIONING SYSTEMS
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内容:This paper presents the fast rotary dirt remover that we have researched and made. Mathematical model of the fast rotary dirt remove is established by theory of infinitesimal calculus. Formulas of velocity distribution and removing efficiency are derived. Tests have been carried out to study the performance of the fast rotary dirt remover Experimental results are found to be close to the theory calculation data.
The fast rotary dirt remover has many advantages, such as high removing efficiency ,small coefficient of local resistance
,no clogging up ,so that it is widely used in heat water heating systems , cool and cooling water system of air conditioning .Fast rotary dirt remover can protect refrigerators , boilers and so on and reduce operation consumption energy of systems.
标题:INTERIOR CIRCULATON AIR CLEANING CRITERION AND ITS APPLICATION
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内容:In this paper, all main physical dimensions representing the properties of the complex interior circulation air cleaning system have been derived. Proceed from balance of materials, these physical dimensions have been sorted out to be dimensionless similarity criteria, from which a conception of cleaning criterion is advanced and appropriate criterion equation have been derived. This equation subtly reveals the inner relationship among various important physical dimensions of possible system design projects correctly, simply and clearly. With various economical parameters, it can be found very easy and believable to carry out work from technique & economy comparison among various design projects to optimum design.
标题:THE CHOLCE OF AIR CONDITIONING SYSTEM FOR OFFICE BUILDING
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内容:In china, the fan-coil unit plus fresh air system is the current method for office building air conditioning. With the development of social and economic situation , this method cannot satisfy demands in many cases .So we urgently need to find new ways for office building air conditioning in coming century.
According to authors design experiences and studies in office building air conditioning field ,this essay evaluates fan-coil unit plus fresh air system and VRV、VAV and other systems by analyzing their cost , comfort and air quality. comparing the characteristics of different system for office building ,the authors propose variable solutions for office building air conditioning .This conclusion is useful reference for the office building air conditioning design.
标题:OPTIMIZATION DESIGNS AND DYNAMIC MULATIONS ABOUT TEMPERATURE REGULATING DEHUMIDIFIERS
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内容:This article deals with an air conditioning system using low grade heat sources such as solar energy, waster heat, etc., by analyzing air conditioning process of using fluid dehumidification for cooling. Analysis shows that the heat efficiency of the system is mainly related to environmental relative humidity and required temperature. The system is especially suitable for comfortable air -conditioning.
标题:OPTIMIZATION DESIGNS AND DYNAMIC MULATIONS ABOUT TEMPERATURE REGULATING DEHUMIDIFIERS
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内容:This paper mainly researches the dynamic traits of the temperature regulating dehumidifiers subsystems such as compressor, cooler (air, water of air-water), throttle valve and vaporizer. As a result, the system of the temperature regulating dehumidifiers obtains the maximum of saving energy, and the optimization designs and dynamic emulations are completed on the computer. The accuracy and creditability of the models and their dynamic emulations have been verified by experiments
标题:BMSonline-A SIMULATED LEARNING ENVIRONMENT OF VAV AIRCONNDITIONING AND ONLINE BUILDING MAN AGEMENT SYSTEM
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内容:A multi -zone VAV air -conditioning system and its local and supervisory with real time or accelerated speed. A window based graphic interface is developed to facilitate the online dialogue between the user and the online Building Management System. The students or users can tune the local and supervisory control loops, change the set-points of control loops and modify the choice of supervisory strategies online to test the effects on the control dynamics as well as the energy and indoor environment.
标题:VIBRATION DIAGOSTIC ANALYSIS AND HVAC APPLICATION
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内容:Investment in monitoring systems can be used toward the reduction of the maintenance cost of modern plants
. Sensors and instrumentation, which record variables describing performance, vibration, and other process parameters, have generated new opportunities in design of trend monitoring systems. These systems can e used toward scheduling of maintenance without impacting planned production planned production schedules. further, by monitoring these variables to provide information about the changing life expectancy maintenance engineers can base service on actual field conditions ,rather than relying solely on standard machine life estimates .Moreover ,these systems can increase the overall efficiency by reducing energy consumption.
标题:BUILDING AND HVAC OPTIMAL CONTROL SIMULATION APPLICATION TO AN OFFICE BUIDLING
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内容:This paper describes the methodology to apply discrete-time optimal control to a building and its HVAC installation, Simulation -based results concerning a passive solar commercial building are presented and discussed .The simulation environment includes the RTNSYS TYPE 56 as reference building model and HVAC detailed models to test the controller with realistic control signals . The optimal controllers sensitivity to meteorological forecasting quality and to other factors is analysed. Its performance is compared to results obtained with a conventional control system to assess the relevancy of optimal control for this application.
标题:STUDY ON FAULT DETECTION AND DIAGNOSIS OF HVAC SYSTEMS WITH PATTERN RECOGNITION
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内容:When some faults take place in HVAC system changing pattern of the state variables of using some statistical analysis, Fourier Trans form, Cluster analysis and variable selection to achieve optimal fault detection parameter. and using recognizing patterns with Mahanobis generalized distance to detect any difference between normal state and abnormal state .In the last paper ( Zheng ,et ,al .,1998) , the high performance of fault detection and diagnosis for an actual water thermal storage HVAC system using this method was verified . The present paper reports an application on the fault detection and diagnosis for the air side system in an actual HVAC/VAV system, and the following five matters have been discussed .a) achieving the system character from the mesured data of the object system using Fourier Transform, b) designing parameters ,c) selecting useful parameters with cluster analysis ,d) process of selecting optimal parameters , or vectors and e) analyzing physical meaning of them.
标题:CONTINUOUS COMMISSIONING A NEW APPROACH TO EFFICIENT OPERATION
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内容:There is convincing evidence to show that buildings which meet the occupiers needs at the optimum of cost and performance are those that have been properly commissioned. Commissioning is generally seen as a process that takes place before the building is handed over to the owner or occupier. But to get the best from buildings the commissioning process should be managed and planned from feasibility through design, construction and operation. This process is known as continuous Commissioning .When appropriately applied it will deliver substantial benefits in reduced: operating cost ,energy consumption and environmental impact while providing better buildings for the occupants and of greater value to the owner . The information and knowledge gained by the process provides rich feedback to design that will accelerate innovation and our progress to a sustainable future.
标题:VALIDATION OF TIME -VARYING SENSOR FAUL TS IN HVAC SYSTEMS
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内容:An automatic strategy to evaluate time-varying sensor biases of building energy management and control systems in building air-conditioning systems is developed. The strategy is based on the fundamental conservation (mass and energy conservation) to avoid the effects of changes of plant performance and working condition. Sensor biases are estimated by minimizing the weighted sum of the squares of the mass and energy balance residuals of selected control volumes using exponential forgetting. The strategy and the validation of the strategy on a central chilling system are presented.
标题:A FAULT DETECTION AND DIAGNOSIS SYSTEM AS A TOOL IN ENERGY EFFICIENT BUILDING USE
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内容:This paper describes a fault detection and diagnosis (FDD) system which is being implemented to a big vocational school .The FDD system utilizes the data collected by the building automation system in monitoring the energy consumptions , indoor conditions ,and control loop performances . When deviations are detected, they are diagnosed with fault-symptom trees . This FDD system guides the building operator in energy efficient building use by helping him locate the causes of undesirable operation.
标题:DEVELOPMENT OF FACILITY MANAGEMENT AND ITS IMPACT ON BUILDING SERVICES ENGINEERING IN CHINA
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内容:Firstly, the paper introduces the definition of "facility management" and the job responsibilities of facility professionals. Secondly , I
标题:TEMPERATURE MEASUREMENT ACCURACY IN AN AIR -HANDLING UNIT MIXING BOX
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内容:Incomplete mixing in ventilation ducts may cause problems when measuring air temperatures. This is particularly true for mixing boxes in air-handling units. Examples of problems are; unit shutdowns due to low limit thermostats, frozen Goils, non-optimal control, increased energy use and unsuccessful fault detection. This paper presents measurements from an air-handling unit mixing box in an office building. The mixing of air in the mixing box is documented under various outside air temperatures and damper positions. Comparisons between standard single-point sensors and averaging sensors are resented .The main results are that the temperature difference between the lower and the upper part of the duct downstream the mixing box can be considerable and increases as outside air temperature decreases. Standard single-point temperature sensors are not sufficient when measuring temperature in mixing boxes.
标题:HYDRAULIC STABILTY ANALYSIS IN HYDRONIC SYSTEMS
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内容:Hydraulic stability is an important criterion to evaluate hydronic networks .In this paper, quantitative definition of hydraulic stability is presented and the calculation method is introduced in detail .To a network, this criterion can be calculated according to the structure and the hydraulic condition of it , and it can also be calculated according to the measured data online . Then, how helpful the value of the criterion in understanding the performance of a network is discussed with the simulation of the control process .At last, several typical networks are discussed as case studies: direct return network, reverse return network and distributed -pumps system.
标题:THE TIME CONSTANT EFFECT OF ROOM ETMPERATURE SENOR ON THE VAV SYSTEM
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内容:This paper analyzes the time constant effect of room temperature sensor on the VAV system. HVACSIM+(A simulation program of HVAC system) is used as the platform of the simulation. In the simulation, two kinds of VAV terminals (pressure dependent and pressure independent) are used. Different simulation results of two kinds of VAV terminals with different time constant are presented. The results show that we can use pressure dependent VAV terminals with different time constant are presented. The results show that we can use pressure dependent VAV terminal to get satisfied control results approximately if the time constant of room temperature sensor is less than 30 second. Because the VAV terminal is very expensive in these days and the pressure dependent terminal is cheaper than the pressure independent terminal by one third or so , we can use the cheaper terminal if the time constant of room temperature sensor can be small .The time constant of one real room temperature sensor of one VAV terminal is measured .The result is that the time constant is too great because of the thermal inertia effect of the microenvironment surrounded by the wall and the enclosure of the temperature controller . A new method of the temperature sensor position in the controller is given out here to decline the time constant of the controller in sensing the room temperature change. By decline the time constant of the room temperature sensor, we can use pressure dependent terminal to cut down the cost the VAV system.
标题:THE STUDY OF ANAPTED PARAMETER(K) OF TOTAL ATRFLOW RATE CONTROL IN VAV SYSTEM
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内容:Using HVAC System Simulation Software (HVACSIM+),
the relation between the adapted parameter, K, of the total airflow rate control method and the system adjustment characteristics , the average variance of system relative required airflow rate , the system resistance (S) and the system ductwork form in variable air volume air conditioning system are studied through a great deal of simulation calculation .The ideal range of K value during initial adjustment is discussed and provided .
标题:AN AIR-CONDITIONING DIANGOSTIC EXPERT SYSTEM BASED ON THE RELATION KNOWLEDGE EXPERESSION MODE
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内容:According to the "FAULT TREE ANALYSIS" method and "SYSTEM SAFELY THEORY", this document firstly establishes the KBS rules of an air-conditional diagnostic expert system on the base of production system. Furthermore it describes and normalizes the KBS rules based on the relation knowledge expression mode, then it realizes the knowledge deduction on the premise of making full use of the strong ability of data processing ability of RDBMS. Simultaneously, the uncertainly deduction system and the double direction deduction between cause and result are also realized.
标题:DEVELOPMENT AND APPLICATION OF WEB BASED HVAC INFORMATION SYSTEM
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内容:This paper briefly introduces history and current situation of the Internet, analyses basic construction and communication mechanism of computer net, presents the importance of the distribution of HVAC information on the Internet.
标题:THE APPLICATION OF FUZZY CONTROL IN THE VAV AIR CONDITIONING SYSTEM
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内容:In recent years, VAV system has became more and more general in the field of air conditioning in our country, for it has some advantages such as energy saving, flexibility, easily automatic control, etc, On the other hand, the traditional PID control of this system often lead to coupling
, and the motor-driven dampers which serve as regulating devices are expensive, unsafe and waste great energy . Fuzzy control has obvious advantages over PID control, based on a new VAV system, it regulated the variable speed fan according to the fuzzy decision form. Thus , it cancels motor-driven dampers at the most degree and reduces coupling and saves energy .
标题:RESEACHAND ANALYSIS IN RELIABLTITY ON THE HEATINAG NETWORK
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内容:This paper has indicated the law that reliability indexes R (t ) of a branch network and a looped network change with scale of the network . In the planning design we suggest to adopt branch network for a heating system, whose scale is smaller. If the networks scale is bigger, We suggest to adopt looped network. It easily reaches or surpasses provided reliability level.
This paper also studies the relation of structure condition of a network, distribution of heat loads and Its level of reliability. From the point of view of reliability, in the district with high density load heat source arrangement is suitable to a branch network. In the network near the heat source to decrease distance between two sectional valves is favorable. In the looped network we may in tall heat source in any place. When load distribution of a network is non-uniform, we must adopt "oppositely directed method" to arrange the pipes and sectional valves to opposite the density distribution of heat loads.
标题:MODELLING AND SIMULATION F VAV TEST RIG
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内容:This paper presents some preliminary results on the modeling and simulation of Variable Air Volume (VAV) test rig in the Department of Building Engineering in UMIST .The modeling for each component such as fan , duct and VAV terminal box with their control system in the test rig has been achieved and the simulations via the logical connection of the component models have been performed by means of an HVACSIM+ platform .The polynomial curve fitting method and the artificial neural network ( ANN) technique are adopted in the modeling of non-linear characteristic of the fan connected with a high slip induction motor installed in the test rig . A nonlinear characteristic terminal box model based on the experimental modeling of a European box is developed which differs from the linear or exponential damper models currently available in HVAC simulations. The ANN fan model and the terminal box model are inserted in the program of HVACSIM+ as the new component subroutine. The accurate simulation results for the VAV test rig via HVACSIM+ are validated by the real system operation performance.
标题:A DOE -2 SIMULATIN MODEL FOR ENERGY PERFORMANCE IN THE GENERAL LIBRARY OF AUCKLAND UNIVERSITY
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内容:In the past many research results were complex and not easily presented in a form that practitioners could use, thus it took years for valuable knowledge to reach the appropriate audience. DOE-2 software is probably one of them. For the experienced architects and engineers with energy performance knowledge. the main difficulty is to organise input files. Judgement and experience in a university library ,one of the largest tertiary libraries in New Zealand ,and provide a comparison of the simulated and measured results for this building .
标题:A STMULATION TOOL FOR THE MODELLING OF WATER AND AIR DUCT NETWORKS
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内容:In this paper a simulation tool is presented which can be used for the modeling of air and water distribution networks. Based on basic approaches for network resistances and topology a model for the calculation of the pressure and flow distribution in any kind of network is developed. Further on it is described how the model can be used as a standalone tool or as an integrated module within the simulation program TRNSYS. With the presented tool it is possible to simulated meshed networks with an arbitrary number of pumps or fans. The applicability of the tool is shown with two examples. In a first example the simulation of a chilled water distribution network within an industrial plant is described . The second example shows the integrated network simulation within TRNSYS for a HVAC system.
标题:A Novel Experimental Modelling Technique for Buoyancy - Driven Flows in Buildings
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内容:A novel and simple technique has been developed for experimental modeling of buoyancy -driven building ventilation airflows . In this technique, fine electrolytically generated hydrogen bubbles function as buoyancy sources to simulated heating elements in buildings and, at the same time, as the tracers for the flow field. Experiments showed that the displacement natural ventilation in single-zone building induced by a line buoyancy source was well reproduced using this new technique, It is demonstrated that compared with existing modelling techniques, the fine bubble approach is simple, economical and compact.
标题: EXPERT SYSTEM FOR THE PRELIMINARY DESIGN OF AIR-CONDITINNG SYSTEMS
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内容:The paper describes a preliminary design model for air-conditioning systems, (ACS). Developed as an expert system, the model has been constructed to reflect the extensive knowledge, experience and understanding of a specialist air-conditioning design engineer .The paper will explain how the ACS expert system attempts to expand the designers selection possibilibities, to reduce the potential tediousness of the design process,and to provide a tutoring system for novice design engineers . Though the use of a case study the paper concludes that the ACS package is a useful addition to air-conditioning desgners.
标题:MODELING OF A COOLING CEILING USING STEADY -STATE ANALYSIS
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内容:The paper presents a new approach for steady-state analysis used to model the heat transfer from a cooling ceiling system. The work is aimed at giving a better insight to crucial parameters of such a model as the contact thermal resistance, and the fin effectiveness of ceiling panel. The convection and radiation heat transfer coefficients to room and loses through the ceiling void are also studied. Experimental data are used to improve the capacity and performance of the ceiling system, but also to evaluate the design of this HVAC system and the applicable control strategies.
标题:MPDEL ANALYSIS OF INTEGRATED HVAC ENGINEERING DATABASE (IHEDB)
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内容:Based on the typical HVAC designing thought, introduces the model of integrated HVAC engineering database (IHEDB), analyzes and classifies the IHEDB model.
标题:CALCULATIO MODELS AND FREQUENCY ANALYSIS OF MOISTURE TRANSFER IN AIR-CONDITIONED BUILDINGS
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内容:Moisture transfer in building components and furnishings has a significant effect on indoor humidity and latent cooling load. M any mathematical models and calculation methods have been proposed to evaluate this sorption effect . Which is actually simple and accurate as well? The result from the discussion in this paper shows that the one-dimensional linear moisture transfer model in which vapour pressure is as only driving potential is both quite simple and in conformity with the situation. The frequency analysis shows that the model of surface moisture sorption and its transfer function method are the simplest and have an appreciate accuracy. The moisture interaction depth should be accurately determined in this model to reach a hither accuracy.
标题:MATHEMATICAL MODEL FOR THE FUSION OF RANULAR ICE
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内容:The analysis of fusion mechanism and fusion process with the heat transfer between ice and water contact directly are very important and complex . Concrete analysis by numerical simulation and experimental method are made on two cases: Constant Amount of Ice and Variable Amount of Ice in column shape container. The mathematical model is obtained from numerical simulation and is examined by the experiments, quite the same results are found through the comparison study.
标题:Duct system performance and energy losses in large commercial buildings
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内容:This paper presents the findings of recent work characterizing thermal distribution systems in four large commercial buildings by the Lawrence Berkeley National Laboratory (LBNL). The buildings are multi-story large-office buildings or retails buildings with floor spaces of more than 2,000m2. They typically contain single-duct or dual-duct constant air volume (CAV) systems, or variable air volume (VAV) systems. Thermal distribution losses in the duct systems studied are categorized into air leakage and conduction, with the latter including convective and radiative losses . This paper reports air leakage results in terms of effective leakage area (ELA) and ASHRAE-defined duct leakage class, and compares with those found in previous studies. The new data of leakage classes indicate that air leakage in large commercial duct systems varies significantly from system to system, and from system section to system section . Most of the duct systems measured are much leakier than the ductwork specified as " unsealed ducts" by ASHRAE. Energy losses due to air leakage and heat conduction through duct systems are significant.
标题:STUDY ON SOME PROBLEMS OF IAQ IN HIGH GRADE OFFICE BUILDINGS IN BEIJING
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内容:In this paper, we investigated some high-level air conditioning buildings, including office building ,government large building and block of flats ,and several main indoor contaminants and indoor microclimate parameter such as temperature , humidity ,atmosphere and air flow velocity were measured . Test results indicated that serious problems of indoor air quality existed in those buildings, as well as, reasons which caused poor indoor quality were made up of manifold factors, not single one, as follows:
(1) Building and decorative materials become one of main pollution sources .
(2)Distribution of airflow patterns in most of air conditioning rooms is not rational because of bad air conditioning design.
(3)Fresh air rate and air change rate are not enough.
(4)The operation and management of air conditioning system are poor.
so how to increase indoor air quality ,providing a health and comfortable indoor environment for the people working in those magnificent office building is an urgent and challenging task for the air conditioning designer.
标题:AN ON-LINE SELF -TUING ANGORITHM OF PI CONTROLLER FOR HEATING AND COOLING GOILS
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内容:An on-line self-tuning method of PI Controller was developed. The method tunes up the P and I gain according to the integral square error (ISE) of the control parameter. When the ISE is less than a pre-defined critical value, the P and I gains are kept unchanged. If the ISE is higher than the critical value, P and I gains are changed based on the low.
Frequency proportion (LFP) of ISE. The P and I gain are decreased when the LEP is less than a pre-defined value. Otherwise the P and I gain are increased properly . This method can be implemented in existing building automation systems. This paper presents the fundamental theory, method, and implementation examples.
