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02299 Natural ventilation performance of a double-skin façade with a solar chimney
13 Space heating and cooling space have been recorded for a year. These data have made possible to analyse the feasibility, regarding functionality and thermal response of the constructive solution adopted. The analysis has been carried out through the climatic description and comparison with the climate measurements for the recorded monitoring period, and afterwards the most important efforts have been done for the thermal analysis that included the thermal comfort and the energetic characterization of the building using the monitored data measurements.
05•02294 Environmentally benign working pairs for adsorption refrigeration Cui, Q. et al. Energy, 2005, 30, (2 4), 261 271. This paper begins from adsorption working pairs: water and ethanol were selected as refrigerants; 13x molecular sieve, silica gel, activated carbon, adsorbent NA and NB, proposed by authors, were selected as adsorbents, and the performance of adsorption working pairs in adsorption refrigeration cycle was studied. The adsorption isotherms of adsorbents (NA and NB) were obtained by high-vacuum gravimetric method. Desorption properties of adsorbents were analysed and compared by thermal analysis method. The performance of adsorption refrigeration was studied on simulation device of adsorption refrigeration cycle. After presentation of adsorption isotherms, the thermodynamic performance for their use in adsorption refrigeration system was calculated. The results show: (1) the maximum adsorption capacity of water on adsorbent NA reaches 0.7 kg/kg, and the maximum adsorption capacity of ethanol on adsorbent NB is 0.68 kg/kg, which is three times that of ethanol on activated carbon, (2) the refrigeration capacity of NA water working pair is 922 kJ/kg, the refrigeration capacity of NB ethanol is 2.4 times that of activated carbon methanol, (3) as environmental friendly and no public hazard adsorption working pair, N A H 2 0 and NB ethanol can substitute activated carbon methanol in adsorption refrigeration system using low-grade heat source.
05•02295 Evaluation of hydronic loop energy and modeling of heated water loop containing multiple variable air volume units with hydronic reheat coils Gao, J. and Smith, T. F. Energy and Buildings, 2005, 37, (3), 189 202. Experimental data recorded for a heating, ventilating, and air conditioning system showed that the daily heated water loop energy calculated by summing the hourly-averaged loop heat transfer for the heated water loop is almost 35% higher than the sum of the daily energy consumed by variable air volume hydronic reheat coils in each zone. The main reason for this difference was attributed to the time delay of the loop return water temperature caused by the water travelling along the loop. This study examines methods to evaluate the heated water loop energy when there are time varying conditions. Data for a heated water loop are used to demonstrate the effects of the time delay on the evaluation of the loop energy. A pipe heat transfer model characterizing the transient response of a fluid flowing through a single pipe is developed to examine the effects of time varying conditions on the pipe thermal response. Based on the pipe heat transfer model, a loop model is constructed to simulate the actual loop with multiple hydronic reheat coils. The comparisons of the simulation results with the data indicate that the loop model is capable of predicting the loop return water temperatures and loop heat transfer based on data.
05•02296 Experimental study of under-floor electric heating system with shape-stabilized PCM plates Lin, K. et al. Energy and Buildings, 2005, 37, (3), 215 220. This paper put forward a new kind of under-floor electric heating system with shape-stabilized phase change material (PCM) plates. Different from conventional PCM, shape-stabilized PCM can keep the shape unchanged during phase change process. Therefore, the PCM leakage danger can be avoided. This system can charge heat by using cheap night-time electricity and discharge the heat stored at daytime. In the present work, the thermal physical properties of shape-stabilized PCM developed by us were measured. A prototype room with this system was set up in Beijing to testify its thermal performance and feasibility of this heating mode. The results show that temperature of the PCM plates upper surface can be kept near the phase transition temperature in whole day and a lot of off-peak period electricity can be used for space heating in stead of using peak period electricity, which obviously lowers the electricity tariff.
05•02297 Labeling design effort for household refrigeratorfreezers in Malaysia Saidur, R. et al. Energy Policy, 2005, 33, (5), 611 618. The paper is particularly concerned with developing a proposed energy guide label for household refrigerator-freezers through consumer research. Survey work conducted throughout Malaysia to develop a comprehensive energy guide label. A simple labelling design with different features and colours was also performed using the labelling concept of other countries (such as Australia, Thailand, and from the EU). There are many steps to implement a labelling program for a
particular energy consuming appliance, such as consumer/stakeholder involvement, design, policy makers' involvement and so on. So, this is a vast area of work. This paper mainly focuses on consumer research in designing or shaping a comprehensive label.
05•02298 Measurement of air leakage in air-handling units and air conditioning ducts Srinivasan, K. Energy and Buildings, 2005, 37, (3), 273 277. The purpose of this article is to report the experience of design and testing of orifice plate-based flow measuring systems for evaluation of air leakages in components of air conditioning systems. Two of the flow measuring stations were designed with a /3 value of 0.405 and 0.418. The third was a dual path unit with orifice plates of/3 value 0.613 and 0.525. The flow rates covered with all the four were from 4 94 1/s and the range of Reynolds numbers is from 5600 to 76,000. The coefficients of discharge were evaluated and compared with the Stolz equation. Measured Ca values are generally higher than those obtained from the equation, the deviations being larger in the low Reynolds number region. Further, it is observed that a second-degree polynomial is inadequate to relate the pressure drop and flow rate. The lower Reynolds number limits set by standards appear to be somewhat conservative.
05•02299 Natural ventilation performance of a double-skin facade with a solar chimney Ding, W. et al. Energy anclBui/dings, 2005, 37, (4), 411 418. Double-skin faqade is getting more and more attention as it provides many possibilities for energy conservation and at the same time creates good indoor environment. In this paper, natural ventilation performance of a double-skin faqade is highlighted. A prototype building is proposed, which is thought to be an eight-storey office building with an atrium space in the north side. The south faqade of the building is a double-skin faqade and a thermal storage space called solar chimney is considered above the double-skin space. Actually, the double-skin space is connected with the chimney channel. Reduced scale model experiments and computational fluid dynamics (CFD) analysis are carried out in this research to evaluate the natural ventilation performance of the prototype building.
05•02300 Performance analysis of activated carbon + HFC134a adsorption coolers Banker, N. D. et al. Carbon, 2004, 42, (1), 117 127. The purpose of this paper is to present the results of performance analysis of a heat driven continuous vapor adsorption refrigerator with activated carbon as the adsorbent and 1,1,1,2-tetrafluoroethane (HFC134a) as the refrigerant. A set of four adsorption cells takes on the role of the mechanical compressor in the conventional vapor compression refrigeration (VCR) system. Three specimens of activated charcoal under various packing densities were investigated. A parametric analysis was carried out with several evaporating, condensing/adsorbing and desorbing temperatures which are typical operating conditions catered to by HFC-134a. A new integrated relative performance evaluation scheme is proposed. It uses the maximum cycle uptake difference as a factor against which the coefficient of performance (COP) and exergetic efficiency are evaluated. It is shown that there is an optimal set of operating conditions wherein the exergetic efficiency is the maximum. A major part of the thermal energy input is for sensible heating of the compressor body.
05•02301 Performance of coupled building energy and CFD simulations Zhai, Z. J. and Chert, Q. Y. Energy and Buildings, 2005, 37, (4), 333 344. The integration of building energy simulation (ES) and computational fluid dynamics (CFD) programs can provide more accurate prediction of building energy use and indoor environment due to the complementary information provided by the two programs. This paper outlines briefly a coupled energy simulation and computational fluid dynamics program with different coupling methods and validates the coupled program by using four sets of experimental data from literature. The comparison of the simulated results with the experimental/empirical data reveals the advantages of the integrated building simulation over the separated energy simulation and computational-fluid-dynamics applications. The program was then used to calculate the cooling load of a large-scale indoor auto-racing complex.
05•02302 Performance study of new adsorbent for solid desiccant cooling Cui, Q. et al. Energy, 2005, 30, (2 4), 273 279. The properties of 13x, silica gel, DH-5 and DH-7 adsorbents proposed by authors in solid desiccant cooling system were investigated. The adsorption isotherms of adsorbents were obtained. Cooling capacity as functions of time had been determined in the experimental device, which accomplished the behaviour of adsorbent desiccant cooling. The performance parameters such as adsorption capacity, air humidity,
Fuel and Energy Abstracts
September 2005
335
05•02294 Environmentally benign working pairs for adsorption refrigeration Cui, Q. et al. Energy, 2005, 30, (2 4), 261 271. This paper begins from adsorption working pairs: water and ethanol were selected as refrigerants; 13x molecular sieve, silica gel, activated carbon, adsorbent NA and NB, proposed by authors, were selected as adsorbents, and the performance of adsorption working pairs in adsorption refrigeration cycle was studied. The adsorption isotherms of adsorbents (NA and NB) were obtained by high-vacuum gravimetric method. Desorption properties of adsorbents were analysed and compared by thermal analysis method. The performance of adsorption refrigeration was studied on simulation device of adsorption refrigeration cycle. After presentation of adsorption isotherms, the thermodynamic performance for their use in adsorption refrigeration system was calculated. The results show: (1) the maximum adsorption capacity of water on adsorbent NA reaches 0.7 kg/kg, and the maximum adsorption capacity of ethanol on adsorbent NB is 0.68 kg/kg, which is three times that of ethanol on activated carbon, (2) the refrigeration capacity of NA water working pair is 922 kJ/kg, the refrigeration capacity of NB ethanol is 2.4 times that of activated carbon methanol, (3) as environmental friendly and no public hazard adsorption working pair, N A H 2 0 and NB ethanol can substitute activated carbon methanol in adsorption refrigeration system using low-grade heat source.
05•02295 Evaluation of hydronic loop energy and modeling of heated water loop containing multiple variable air volume units with hydronic reheat coils Gao, J. and Smith, T. F. Energy and Buildings, 2005, 37, (3), 189 202. Experimental data recorded for a heating, ventilating, and air conditioning system showed that the daily heated water loop energy calculated by summing the hourly-averaged loop heat transfer for the heated water loop is almost 35% higher than the sum of the daily energy consumed by variable air volume hydronic reheat coils in each zone. The main reason for this difference was attributed to the time delay of the loop return water temperature caused by the water travelling along the loop. This study examines methods to evaluate the heated water loop energy when there are time varying conditions. Data for a heated water loop are used to demonstrate the effects of the time delay on the evaluation of the loop energy. A pipe heat transfer model characterizing the transient response of a fluid flowing through a single pipe is developed to examine the effects of time varying conditions on the pipe thermal response. Based on the pipe heat transfer model, a loop model is constructed to simulate the actual loop with multiple hydronic reheat coils. The comparisons of the simulation results with the data indicate that the loop model is capable of predicting the loop return water temperatures and loop heat transfer based on data.
05•02296 Experimental study of under-floor electric heating system with shape-stabilized PCM plates Lin, K. et al. Energy and Buildings, 2005, 37, (3), 215 220. This paper put forward a new kind of under-floor electric heating system with shape-stabilized phase change material (PCM) plates. Different from conventional PCM, shape-stabilized PCM can keep the shape unchanged during phase change process. Therefore, the PCM leakage danger can be avoided. This system can charge heat by using cheap night-time electricity and discharge the heat stored at daytime. In the present work, the thermal physical properties of shape-stabilized PCM developed by us were measured. A prototype room with this system was set up in Beijing to testify its thermal performance and feasibility of this heating mode. The results show that temperature of the PCM plates upper surface can be kept near the phase transition temperature in whole day and a lot of off-peak period electricity can be used for space heating in stead of using peak period electricity, which obviously lowers the electricity tariff.
05•02297 Labeling design effort for household refrigeratorfreezers in Malaysia Saidur, R. et al. Energy Policy, 2005, 33, (5), 611 618. The paper is particularly concerned with developing a proposed energy guide label for household refrigerator-freezers through consumer research. Survey work conducted throughout Malaysia to develop a comprehensive energy guide label. A simple labelling design with different features and colours was also performed using the labelling concept of other countries (such as Australia, Thailand, and from the EU). There are many steps to implement a labelling program for a
particular energy consuming appliance, such as consumer/stakeholder involvement, design, policy makers' involvement and so on. So, this is a vast area of work. This paper mainly focuses on consumer research in designing or shaping a comprehensive label.
05•02298 Measurement of air leakage in air-handling units and air conditioning ducts Srinivasan, K. Energy and Buildings, 2005, 37, (3), 273 277. The purpose of this article is to report the experience of design and testing of orifice plate-based flow measuring systems for evaluation of air leakages in components of air conditioning systems. Two of the flow measuring stations were designed with a /3 value of 0.405 and 0.418. The third was a dual path unit with orifice plates of/3 value 0.613 and 0.525. The flow rates covered with all the four were from 4 94 1/s and the range of Reynolds numbers is from 5600 to 76,000. The coefficients of discharge were evaluated and compared with the Stolz equation. Measured Ca values are generally higher than those obtained from the equation, the deviations being larger in the low Reynolds number region. Further, it is observed that a second-degree polynomial is inadequate to relate the pressure drop and flow rate. The lower Reynolds number limits set by standards appear to be somewhat conservative.
05•02299 Natural ventilation performance of a double-skin facade with a solar chimney Ding, W. et al. Energy anclBui/dings, 2005, 37, (4), 411 418. Double-skin faqade is getting more and more attention as it provides many possibilities for energy conservation and at the same time creates good indoor environment. In this paper, natural ventilation performance of a double-skin faqade is highlighted. A prototype building is proposed, which is thought to be an eight-storey office building with an atrium space in the north side. The south faqade of the building is a double-skin faqade and a thermal storage space called solar chimney is considered above the double-skin space. Actually, the double-skin space is connected with the chimney channel. Reduced scale model experiments and computational fluid dynamics (CFD) analysis are carried out in this research to evaluate the natural ventilation performance of the prototype building.
05•02300 Performance analysis of activated carbon + HFC134a adsorption coolers Banker, N. D. et al. Carbon, 2004, 42, (1), 117 127. The purpose of this paper is to present the results of performance analysis of a heat driven continuous vapor adsorption refrigerator with activated carbon as the adsorbent and 1,1,1,2-tetrafluoroethane (HFC134a) as the refrigerant. A set of four adsorption cells takes on the role of the mechanical compressor in the conventional vapor compression refrigeration (VCR) system. Three specimens of activated charcoal under various packing densities were investigated. A parametric analysis was carried out with several evaporating, condensing/adsorbing and desorbing temperatures which are typical operating conditions catered to by HFC-134a. A new integrated relative performance evaluation scheme is proposed. It uses the maximum cycle uptake difference as a factor against which the coefficient of performance (COP) and exergetic efficiency are evaluated. It is shown that there is an optimal set of operating conditions wherein the exergetic efficiency is the maximum. A major part of the thermal energy input is for sensible heating of the compressor body.
05•02301 Performance of coupled building energy and CFD simulations Zhai, Z. J. and Chert, Q. Y. Energy and Buildings, 2005, 37, (4), 333 344. The integration of building energy simulation (ES) and computational fluid dynamics (CFD) programs can provide more accurate prediction of building energy use and indoor environment due to the complementary information provided by the two programs. This paper outlines briefly a coupled energy simulation and computational fluid dynamics program with different coupling methods and validates the coupled program by using four sets of experimental data from literature. The comparison of the simulated results with the experimental/empirical data reveals the advantages of the integrated building simulation over the separated energy simulation and computational-fluid-dynamics applications. The program was then used to calculate the cooling load of a large-scale indoor auto-racing complex.
05•02302 Performance study of new adsorbent for solid desiccant cooling Cui, Q. et al. Energy, 2005, 30, (2 4), 273 279. The properties of 13x, silica gel, DH-5 and DH-7 adsorbents proposed by authors in solid desiccant cooling system were investigated. The adsorption isotherms of adsorbents were obtained. Cooling capacity as functions of time had been determined in the experimental device, which accomplished the behaviour of adsorbent desiccant cooling. The performance parameters such as adsorption capacity, air humidity,
Fuel and Energy Abstracts
September 2005
335