The knowledge representation mode and inference control strategy were analyzed according to the specialties of air-conditioning cooling/heating sources selection. The constructing idea and working procedure for knowle...The knowledge representation mode and inference control strategy were analyzed according to the specialties of air-conditioning cooling/heating sources selection. The constructing idea and working procedure for knowledge base and inference engine were proposed while the realization technique of the C language was discussed. An intelligent decision support system (IDSS) model based on such knowledge representation and inference mechanism was developed by domain engineers. The model was verified to have a small kernel and powerful capability in list processing and data driving, which was successfully used in the design of a cooling/heating sources system for a large-sized office building.展开更多
A new ground source heat pump system combined with radiant heating/cooling is proposed, and the principles and the advantages of the system are analyzed. A demonstration of the system is applied to a rebuilt building...A new ground source heat pump system combined with radiant heating/cooling is proposed, and the principles and the advantages of the system are analyzed. A demonstration of the system is applied to a rebuilt building： Xijindu exhibition hall, which is located in Zhenjiang city in China. Numerical studies on the thermal comfort and energy consumption of the system are carded out by using TRNSYS software. The results indicate that the system with the radiant floor method or the radiant ceiling method shows good thermal comfort without mechanical ventilation in winter. However, the system with either of the methods should add mechanical ventilation to ensure good comfort in summer. At the same level of thermal comfort, it can also be found that the annual energy consumption of the radiant ceiling system is less than that of the radiant floor system.展开更多
Selection of air conditioning（AC） cold/heat sources generally concerns about certain aspects and cannot reveal the whole profile of the problems. Grey relation analysis （GRA） is a data processing method to categor...Selection of air conditioning（AC） cold/heat sources generally concerns about certain aspects and cannot reveal the whole profile of the problems. Grey relation analysis （GRA） is a data processing method to categorize the correlation extent of compared sequences and a certain reference sequence in a system with uncertain information. It is applied to evaluating and selecting AC cold/heat sources from four main aspects, which are technology, economy, reliability, and operation and management. Case study shows that the result for selecting AC cold/heat sources with the GRA method can be more reasonable and convincible. Thus it offers a new approach for designers in heating, ventilating and air conditioning field to compare and evaluate different AC cold/heat sou rces.展开更多
The high potential of geothermal energy in quantity and availability can be a great option, facing the huge problem of growing energy use linked with the climatic problems. Therefore, it is necessary to reduce costs a...The high potential of geothermal energy in quantity and availability can be a great option, facing the huge problem of growing energy use linked with the climatic problems. Therefore, it is necessary to reduce costs and risks for the use of geothermal energy sources. Because most of the problems have to do with insufficient knowledge about the conditions in the earth crust, the key to take root of geothermal energy is widespread research. The cooling system allows the use of all needed devices in deep boreholes without strict time or temperature limitations, which promotes the achieving of comprehensive information. To develop the purpose-built components among conducting experiments about the thermodynamic processes, a prototype is provided step by step.展开更多
This paper reports the on-site performance evaluation of conventional and improved gas engine-driven VRF （variable refrigerant flow） units and （abbreviated as GHP） units. The study aims to elucidate two actual GHP...This paper reports the on-site performance evaluation of conventional and improved gas engine-driven VRF （variable refrigerant flow） units and （abbreviated as GHP） units. The study aims to elucidate two actual GHP units by using the probe insertion method. There is a tendency to decrease energy efficiency compared to a high loading factor. GHP operation was almost all part load operation. This on-site evaluation indicates a clear difference between conventional and improved GHP.展开更多
Using correlation analyses, composite analyses, and singular value decomposition, the relationship between the atmospheric cold source over the eastern Tibetan Plateau and atmospheric/ocean circulation is discussed. I...Using correlation analyses, composite analyses, and singular value decomposition, the relationship between the atmospheric cold source over the eastern Tibetan Plateau and atmospheric/ocean circulation is discussed. In winter, the anomaly of the strong (weak) atmospheric cold source over the eastern plateau causes low-level anomalous north (south) winds to appear in eastern China and low-level anomaly zonal west (east) winds to prevail in the equatorial Pacific from spring to autumn. This contributes to the anomalous warm (cold) sea surface temperature the following autumn and winter. In addition, the anomalous variation of sea surface temperature over the equatorial middle and eastern Pacific in winter can influence the snow depth and intensity of the cold source over the plateau in the following winter due to variation of the summer west Pacific subtropical high.展开更多
In this work an economical evaluation that established the viability of a low enthalpy geothermal resource as an energy source in north Africa is presented. The factors considered included the payback period, average ...In this work an economical evaluation that established the viability of a low enthalpy geothermal resource as an energy source in north Africa is presented. The factors considered included the payback period, average rate of return, net present value, and net benefit-cost ratio. The model was based on utilising the energy source to energise four models that comprised thermal equipment consisting of water/air cooled single/half effect lithium bromide water mixture absorption chillers and an R-245fa organic Rankine cycle. These modelled cycles were based on the energy demand for Waddan city a community in southern Libya which has a demand for combined cooling/electricity only or cooling/electricity with district hot water supply. The results revealed that all of the proposed simulated stand-alone models, except the water-cooled half effect chiller, are not economically viable unless they are heavily subsidized or combined with the district hot water supply at least in the winter season.展开更多
This paper mainly shows the demonstration of solar air conditioning systems in China, which includes LiBr-H2O absorption cooling, silica gel-water adsorption chiller, desiccant cooling and hybrid integrated energy sys...This paper mainly shows the demonstration of solar air conditioning systems in China, which includes LiBr-H2O absorption cooling, silica gel-water adsorption chiller, desiccant cooling and hybrid integrated energy systems for buildings. The match of solar collector types and chiller types have been discussed and suggested.展开更多
The building sector has a significant weight in the global energy consumption in almost of the countries. So, there is a high potential for increasing its energy efficiency. With the enforcement of the energetic certi...The building sector has a significant weight in the global energy consumption in almost of the countries. So, there is a high potential for increasing its energy efficiency. With the enforcement of the energetic certification, it was tried to select different solutions that presents less energy consumption and waste, as well as an effective reduction of CO2 emissions. This work fits in this perspective, since the main goal is to evaluate the contribution of passive and active solutions that can be used in buildings for the improvement of its energetic efficiency, as well as to evaluate the contribution of renewable energy sources. Contribution of solar systems for hot water heating and electric energy production has been studied, as well as cogeneration, Combined Heat and Power （CHP）. The case studied is a hotel. To improve the building performance, there were proposed several changes, with the goal of evaluating the contribution of the different solutions proposed. It was concluded that they contribute to a reduction of thermal needs of 25.2% and avoided emissions of CO2 is 30.4%. The analysis of the implementation of trigeneration, Combined Heat, Cooling and Power （CHCP） turns it executable. The payback period is less than 8 years.展开更多
This paper refers to an integrated mCCHP （micro-combined cooling heat and power） systems dedicated for isolated residents with energetic independence. The only energy sources are wood pellet and solar energy. The pr...This paper refers to an integrated mCCHP （micro-combined cooling heat and power） systems dedicated for isolated residents with energetic independence. The only energy sources are wood pellet and solar energy. The proposed trigeneration system is based on mCHP （micro-combined heat and power） unit with Stirling engine, photovoltaic panels, thermal solar collector and pellet boiler. The proposed mCCHP system utilizes the exceeding amount of heat in the summer for producing the necessary cooling. A residential building with known energy consumption is determined load curves that must be covered by mCCHP system. The paper analyzes four structures of trigeneration systems with thermal activation chiller and two structures of trigeneration systems with mechanical compression chiller. Performance indicators are determined based on energy balance equations for each variant. It compares the performances and establishes the best option.展开更多
Preliminary investigation shows that air sourced type heat pumps by energy efficiency are competitive with gas boilers having 93% of coefficient of performance （COP） if heat pumps are used in climatic zones, having ...Preliminary investigation shows that air sourced type heat pumps by energy efficiency are competitive with gas boilers having 93% of coefficient of performance （COP） if heat pumps are used in climatic zones, having outside air temperature higher than （-3 ℃ to -5 ℃）. But, in such conditions the heat pump＇s evaporator is covered by ice crust, which cuts off the flow of outside air-heat source through the evaporator of heat pump. For avoiding stating problems it is recommended to use as heat source a mixture of waste warm gases. In this article a high efficiency heating-cooling system is developed, consisting of warm gases mixture sourced heat pump, heating boiler operating simultaneously with heat pump and solar air heater. The heating demand of the served house is shared between boiler and heat pump. Instead of outside air the warm gases mixture enters into evaporator of heat pump. A new construction of heat exchanger was developed. The article presents the structure and principle of operation, as well as the method for optimization and design of suggested system. Analysis proved high energy efficiency and cost effectiveness of the new system.展开更多
文摘The knowledge representation mode and inference control strategy were analyzed according to the specialties of air-conditioning cooling/heating sources selection. The constructing idea and working procedure for knowledge base and inference engine were proposed while the realization technique of the C language was discussed. An intelligent decision support system (IDSS) model based on such knowledge representation and inference mechanism was developed by domain engineers. The model was verified to have a small kernel and powerful capability in list processing and data driving, which was successfully used in the design of a cooling/heating sources system for a large-sized office building.
基金The National Natural Science Foundation of China(No. 51036001 )the Natural Science Foundation of Jiangsu Province(No. BK2010043)
文摘A new ground source heat pump system combined with radiant heating/cooling is proposed, and the principles and the advantages of the system are analyzed. A demonstration of the system is applied to a rebuilt building： Xijindu exhibition hall, which is located in Zhenjiang city in China. Numerical studies on the thermal comfort and energy consumption of the system are carded out by using TRNSYS software. The results indicate that the system with the radiant floor method or the radiant ceiling method shows good thermal comfort without mechanical ventilation in winter. However, the system with either of the methods should add mechanical ventilation to ensure good comfort in summer. At the same level of thermal comfort, it can also be found that the annual energy consumption of the radiant ceiling system is less than that of the radiant floor system.
文摘Selection of air conditioning（AC） cold/heat sources generally concerns about certain aspects and cannot reveal the whole profile of the problems. Grey relation analysis （GRA） is a data processing method to categorize the correlation extent of compared sequences and a certain reference sequence in a system with uncertain information. It is applied to evaluating and selecting AC cold/heat sources from four main aspects, which are technology, economy, reliability, and operation and management. Case study shows that the result for selecting AC cold/heat sources with the GRA method can be more reasonable and convincible. Thus it offers a new approach for designers in heating, ventilating and air conditioning field to compare and evaluate different AC cold/heat sou rces.
文摘The high potential of geothermal energy in quantity and availability can be a great option, facing the huge problem of growing energy use linked with the climatic problems. Therefore, it is necessary to reduce costs and risks for the use of geothermal energy sources. Because most of the problems have to do with insufficient knowledge about the conditions in the earth crust, the key to take root of geothermal energy is widespread research. The cooling system allows the use of all needed devices in deep boreholes without strict time or temperature limitations, which promotes the achieving of comprehensive information. To develop the purpose-built components among conducting experiments about the thermodynamic processes, a prototype is provided step by step.
文摘This paper reports the on-site performance evaluation of conventional and improved gas engine-driven VRF （variable refrigerant flow） units and （abbreviated as GHP） units. The study aims to elucidate two actual GHP units by using the probe insertion method. There is a tendency to decrease energy efficiency compared to a high loading factor. GHP operation was almost all part load operation. This on-site evaluation indicates a clear difference between conventional and improved GHP.
基金Natural Science Foundation of China (90711003, 40633018)
文摘Using correlation analyses, composite analyses, and singular value decomposition, the relationship between the atmospheric cold source over the eastern Tibetan Plateau and atmospheric/ocean circulation is discussed. In winter, the anomaly of the strong (weak) atmospheric cold source over the eastern plateau causes low-level anomalous north (south) winds to appear in eastern China and low-level anomaly zonal west (east) winds to prevail in the equatorial Pacific from spring to autumn. This contributes to the anomalous warm (cold) sea surface temperature the following autumn and winter. In addition, the anomalous variation of sea surface temperature over the equatorial middle and eastern Pacific in winter can influence the snow depth and intensity of the cold source over the plateau in the following winter due to variation of the summer west Pacific subtropical high.
文摘In this work an economical evaluation that established the viability of a low enthalpy geothermal resource as an energy source in north Africa is presented. The factors considered included the payback period, average rate of return, net present value, and net benefit-cost ratio. The model was based on utilising the energy source to energise four models that comprised thermal equipment consisting of water/air cooled single/half effect lithium bromide water mixture absorption chillers and an R-245fa organic Rankine cycle. These modelled cycles were based on the energy demand for Waddan city a community in southern Libya which has a demand for combined cooling/electricity only or cooling/electricity with district hot water supply. The results revealed that all of the proposed simulated stand-alone models, except the water-cooled half effect chiller, are not economically viable unless they are heavily subsidized or combined with the district hot water supply at least in the winter season.
基金support of this research from Nation-al Key Technologies R&D Program ( No.2006BAA04B03) is gratefully acknowledged.
文摘This paper mainly shows the demonstration of solar air conditioning systems in China, which includes LiBr-H2O absorption cooling, silica gel-water adsorption chiller, desiccant cooling and hybrid integrated energy systems for buildings. The match of solar collector types and chiller types have been discussed and suggested.
文摘The building sector has a significant weight in the global energy consumption in almost of the countries. So, there is a high potential for increasing its energy efficiency. With the enforcement of the energetic certification, it was tried to select different solutions that presents less energy consumption and waste, as well as an effective reduction of CO2 emissions. This work fits in this perspective, since the main goal is to evaluate the contribution of passive and active solutions that can be used in buildings for the improvement of its energetic efficiency, as well as to evaluate the contribution of renewable energy sources. Contribution of solar systems for hot water heating and electric energy production has been studied, as well as cogeneration, Combined Heat and Power （CHP）. The case studied is a hotel. To improve the building performance, there were proposed several changes, with the goal of evaluating the contribution of the different solutions proposed. It was concluded that they contribute to a reduction of thermal needs of 25.2% and avoided emissions of CO2 is 30.4%. The analysis of the implementation of trigeneration, Combined Heat, Cooling and Power （CHCP） turns it executable. The payback period is less than 8 years.
文摘This paper refers to an integrated mCCHP （micro-combined cooling heat and power） systems dedicated for isolated residents with energetic independence. The only energy sources are wood pellet and solar energy. The proposed trigeneration system is based on mCHP （micro-combined heat and power） unit with Stirling engine, photovoltaic panels, thermal solar collector and pellet boiler. The proposed mCCHP system utilizes the exceeding amount of heat in the summer for producing the necessary cooling. A residential building with known energy consumption is determined load curves that must be covered by mCCHP system. The paper analyzes four structures of trigeneration systems with thermal activation chiller and two structures of trigeneration systems with mechanical compression chiller. Performance indicators are determined based on energy balance equations for each variant. It compares the performances and establishes the best option.
文摘Preliminary investigation shows that air sourced type heat pumps by energy efficiency are competitive with gas boilers having 93% of coefficient of performance （COP） if heat pumps are used in climatic zones, having outside air temperature higher than （-3 ℃ to -5 ℃）. But, in such conditions the heat pump＇s evaporator is covered by ice crust, which cuts off the flow of outside air-heat source through the evaporator of heat pump. For avoiding stating problems it is recommended to use as heat source a mixture of waste warm gases. In this article a high efficiency heating-cooling system is developed, consisting of warm gases mixture sourced heat pump, heating boiler operating simultaneously with heat pump and solar air heater. The heating demand of the served house is shared between boiler and heat pump. Instead of outside air the warm gases mixture enters into evaporator of heat pump. A new construction of heat exchanger was developed. The article presents the structure and principle of operation, as well as the method for optimization and design of suggested system. Analysis proved high energy efficiency and cost effectiveness of the new system.
