本文研究了一种新型光伏/光热一体化(PV/T)复合热源热泵热水系统,将多孔扁盒式PV/T集热板与空气源热泵相结合,根据不同控制方式组合成双热源并联、单太阳能和单空气能三种不同运行模式。在室外环境温度28.5℃下,将200 L 30℃热水加热到5...本文研究了一种新型光伏/光热一体化(PV/T)复合热源热泵热水系统,将多孔扁盒式PV/T集热板与空气源热泵相结合,根据不同控制方式组合成双热源并联、单太阳能和单空气能三种不同运行模式。在室外环境温度28.5℃下,将200 L 30℃热水加热到55℃,研究了加热时间、热水温度、COP等性能的变化规律,结果表明双热源并联运行模式下分别比单太阳能模式和单空气能模式的加热时间缩短了42%和54%,COP分别提高了32.78%和47.64%;同时实验研究了在夏季工况下将200 L水从9∶00循环加热到17∶00过程中系统热性能,探讨了太阳辐射强度、PV/T集热板温度对光电/光热效率的影响,通过实验对比可以得出在热电模式下系统的光电效率η_(pv)比单一光电模式平均高25.8%.展开更多
From the viewpoints of environmental conservation and energy efficiency,seawater-source heat pump system(SWHP) to provide district cooling and heating is applied in coastal areas.Based on the system,a heat transfer mo...From the viewpoints of environmental conservation and energy efficiency,seawater-source heat pump system(SWHP) to provide district cooling and heating is applied in coastal areas.Based on the system,a heat transfer model was established for cast heat exchanger(CHE) adopted by SWHP systems.The CHE consists of pipes immersed in the seawater and used for transferring heat between the seawater and the heat exchanger pipes of SWHP system.An experimental study was carried out to test the validity of the model.A program was developed in VB language and the effects of inlet temperature,flow rate of the secondary refrigerant and length of CHE on the results were investigated.The results of the numerical simulation are in consistence with the experiments in both winter and summer conditions.As a result,application of SWHP systems with CHE in coastal areas in China is feasible due to the favorable geographical conditions and environment.展开更多
Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar ener...Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar energy collection and heat storage capabilities as an infinite heat source/heat sink at the base of permeable pavements, which can provide excellent temperature gradients for GHP＇s. Experimental rigs were setup up at The University of Edinbttrgh for a combined permeable pavement and GHP system. At the base of a pavement structure （approximately 1 meter） below the ground＇s surface, temperatures are constant of 10℃ in the U.K all year round. The GHP performance efficiency was analysed by the coefficient of performance （COP） in a heating cycle and the energy efficiency ratio （EER） in a cooling cycle. The mean COP and EER for both systems averaged between 2-4.5 and 3-5 respectively. The combined GHP and pavement structure operated at an optimum efficiency for both heating and cooling cycles and has shown to be unaffected by higher summer or lower winter temperatures. This hybrid system is an attractive renewable energy technology and has additional environmental benefits such as urban runoff reuse and recycling.展开更多
A new air-water dual source heat pump water heater with heat recovery is proposed.The heat pump system can heat water by using a single air source,a single water source,or air-water dual sources.The water is first pre...A new air-water dual source heat pump water heater with heat recovery is proposed.The heat pump system can heat water by using a single air source,a single water source,or air-water dual sources.The water is first pre-heated by waste hot water,then heated by the heat pump.Waste heat is recovered by first preheating the cold water and as water source of the heat pump.According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump,and the gain coefficient of heat recovery-preheater,the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method.The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions.The developed approaches can provide reference for the optimization of the operating modes and parameters.The results of analysis and experiments show that the coefficient of performance of the device can reach 4-5.5 in winter,twice as much as air source heat pump water heater.The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source.Thus,the effect of energy saving of the new system is obvious.On the other hand,the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump,which also has theoretical significance and practical value.展开更多
Boron concentrations and isotope compositions have been measured for 93 water samples from the hot springs and drill-holes in the geothermal system in the Yunnan-Tibet Geothermal Belt(YTGB),China.Boron concentrations ...Boron concentrations and isotope compositions have been measured for 93 water samples from the hot springs and drill-holes in the geothermal system in the Yunnan-Tibet Geothermal Belt(YTGB),China.Boron concentrations range from 0.036–472.4ppm,and theδ11B values range from -16.0‰to 13.1‰,indicating the non-marine origin for each geothermal system.We observed a clear binary mixing relationship between the B concentrations and B isotope compositions in Tibet geothermal area.This relationship can be well explained by two sources,i.e.,marine carbonate rocks and magmatic rocks,for the Tibet geothermal water.No evidence supports a mantle contribution to B.In addition,we found that the precipitation only plays a dilution role for B of geothermal waters.δ11B values for the precipitation across the southern Tibetan Plateau area range from -6.0‰ to -6.8‰at least.Due to data scarcity in Yunnan geothermal area,we observed possible different boron sources from the Tibet geothermal system.Comparing it with other geothermal systems in the world,we found that the samples from YTGB have the lowestδ11B values and the largest range of B concentration,which might be related to their special geological background.On the whole,the world geothermalδ11B-Cl/B relation suggests a mixing process between marine and non-marine sources.Additionally,we suggest that B source of B-enriched geothermal waters is mainly from B-enriched crustal country-rocks,instead of mantle.展开更多
文摘本文研究了一种新型光伏/光热一体化(PV/T)复合热源热泵热水系统,将多孔扁盒式PV/T集热板与空气源热泵相结合,根据不同控制方式组合成双热源并联、单太阳能和单空气能三种不同运行模式。在室外环境温度28.5℃下,将200 L 30℃热水加热到55℃,研究了加热时间、热水温度、COP等性能的变化规律,结果表明双热源并联运行模式下分别比单太阳能模式和单空气能模式的加热时间缩短了42%和54%,COP分别提高了32.78%和47.64%;同时实验研究了在夏季工况下将200 L水从9∶00循环加热到17∶00过程中系统热性能,探讨了太阳辐射强度、PV/T集热板温度对光电/光热效率的影响,通过实验对比可以得出在热电模式下系统的光电效率η_(pv)比单一光电模式平均高25.8%.
基金Project(2006BAJ04A15-03) supported by the National Science and Technology Pillar Program during the Eleventh Five-year Plan Period
文摘From the viewpoints of environmental conservation and energy efficiency,seawater-source heat pump system(SWHP) to provide district cooling and heating is applied in coastal areas.Based on the system,a heat transfer model was established for cast heat exchanger(CHE) adopted by SWHP systems.The CHE consists of pipes immersed in the seawater and used for transferring heat between the seawater and the heat exchanger pipes of SWHP system.An experimental study was carried out to test the validity of the model.A program was developed in VB language and the effects of inlet temperature,flow rate of the secondary refrigerant and length of CHE on the results were investigated.The results of the numerical simulation are in consistence with the experiments in both winter and summer conditions.As a result,application of SWHP systems with CHE in coastal areas in China is feasible due to the favorable geographical conditions and environment.
文摘Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar energy collection and heat storage capabilities as an infinite heat source/heat sink at the base of permeable pavements, which can provide excellent temperature gradients for GHP＇s. Experimental rigs were setup up at The University of Edinbttrgh for a combined permeable pavement and GHP system. At the base of a pavement structure （approximately 1 meter） below the ground＇s surface, temperatures are constant of 10℃ in the U.K all year round. The GHP performance efficiency was analysed by the coefficient of performance （COP） in a heating cycle and the energy efficiency ratio （EER） in a cooling cycle. The mean COP and EER for both systems averaged between 2-4.5 and 3-5 respectively. The combined GHP and pavement structure operated at an optimum efficiency for both heating and cooling cycles and has shown to be unaffected by higher summer or lower winter temperatures. This hybrid system is an attractive renewable energy technology and has additional environmental benefits such as urban runoff reuse and recycling.
基金supported by the National Natural Science Foundation of China (Grant No. 51076147)
文摘A new air-water dual source heat pump water heater with heat recovery is proposed.The heat pump system can heat water by using a single air source,a single water source,or air-water dual sources.The water is first pre-heated by waste hot water,then heated by the heat pump.Waste heat is recovered by first preheating the cold water and as water source of the heat pump.According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump,and the gain coefficient of heat recovery-preheater,the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method.The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions.The developed approaches can provide reference for the optimization of the operating modes and parameters.The results of analysis and experiments show that the coefficient of performance of the device can reach 4-5.5 in winter,twice as much as air source heat pump water heater.The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source.Thus,the effect of energy saving of the new system is obvious.On the other hand,the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump,which also has theoretical significance and practical value.
基金supported by National Natural Science Foundation of China(Grant Nos.41203012,41030317)China Geological Survey(Grant No.1212011085524)
文摘Boron concentrations and isotope compositions have been measured for 93 water samples from the hot springs and drill-holes in the geothermal system in the Yunnan-Tibet Geothermal Belt(YTGB),China.Boron concentrations range from 0.036–472.4ppm,and theδ11B values range from -16.0‰to 13.1‰,indicating the non-marine origin for each geothermal system.We observed a clear binary mixing relationship between the B concentrations and B isotope compositions in Tibet geothermal area.This relationship can be well explained by two sources,i.e.,marine carbonate rocks and magmatic rocks,for the Tibet geothermal water.No evidence supports a mantle contribution to B.In addition,we found that the precipitation only plays a dilution role for B of geothermal waters.δ11B values for the precipitation across the southern Tibetan Plateau area range from -6.0‰ to -6.8‰at least.Due to data scarcity in Yunnan geothermal area,we observed possible different boron sources from the Tibet geothermal system.Comparing it with other geothermal systems in the world,we found that the samples from YTGB have the lowestδ11B values and the largest range of B concentration,which might be related to their special geological background.On the whole,the world geothermalδ11B-Cl/B relation suggests a mixing process between marine and non-marine sources.Additionally,we suggest that B source of B-enriched geothermal waters is mainly from B-enriched crustal country-rocks,instead of mantle.
