文章提出了一种利用高温热泵回收冷却水余热制备中、高温热水的方案。通过建立简化的热力学模型,分析冷、热源温度对热泵单位制热量、单位压缩功及COP(Coefficient of Performance,能效比)值的影响。并从经济节能和环境保护两个方面进...文章提出了一种利用高温热泵回收冷却水余热制备中、高温热水的方案。通过建立简化的热力学模型,分析冷、热源温度对热泵单位制热量、单位压缩功及COP(Coefficient of Performance,能效比)值的影响。并从经济节能和环境保护两个方面进行了效益分析,结果表明:与传统的蒸汽加热制备热水相比,高温热泵回收冷却水余热制备中、高温热水的方案具有经济效益和环境效益,更符合节能减排要求。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
Heat and mass transfer of a LiBr/water absorption heat pump system(AHP)was experimentally studied during working a heating-up mode.The examination was performed for a single spiral tube,which was simulated for heat tr...Heat and mass transfer of a LiBr/water absorption heat pump system(AHP)was experimentally studied during working a heating-up mode.The examination was performed for a single spiral tube,which was simulated for heat transfer tubes in an absorber.The inside and outside of the tube were subjected to a film flow of the absorption liquid and exposed to the atmosphere,respectively.The maximum temperature of the absorption liquid was observed not at the entrance but in the region a little downward from the entrance in the tube.The steam absorption convective heat transfer coefficient between the liquid film flowing down and the inside wall of the temperature and the film temperature at the maximum temperature location and the bottom.The film heat and mass transfer coefficients rose with increasing Reynolds number of the liquid film stream.The coefficients showed opposite trend to the empirical correlation reported for laminar film flow on a straight smooth tube in a refrigeration mode in the past work.The fact can be caused due to a turbulent promotion effect of the liquid in a spiral tube.展开更多
文摘文章提出了一种利用高温热泵回收冷却水余热制备中、高温热水的方案。通过建立简化的热力学模型,分析冷、热源温度对热泵单位制热量、单位压缩功及COP(Coefficient of Performance,能效比)值的影响。并从经济节能和环境保护两个方面进行了效益分析,结果表明:与传统的蒸汽加热制备热水相比,高温热泵回收冷却水余热制备中、高温热水的方案具有经济效益和环境效益,更符合节能减排要求。
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The authorsacknowledge financial support by the Research and Development Program for Innovative Energy Efficiency Technology under the New Energy and Industrial Technology Development Organization(NEDO)project(Grant no.11501835-O).
文摘Heat and mass transfer of a LiBr/water absorption heat pump system(AHP)was experimentally studied during working a heating-up mode.The examination was performed for a single spiral tube,which was simulated for heat transfer tubes in an absorber.The inside and outside of the tube were subjected to a film flow of the absorption liquid and exposed to the atmosphere,respectively.The maximum temperature of the absorption liquid was observed not at the entrance but in the region a little downward from the entrance in the tube.The steam absorption convective heat transfer coefficient between the liquid film flowing down and the inside wall of the temperature and the film temperature at the maximum temperature location and the bottom.The film heat and mass transfer coefficients rose with increasing Reynolds number of the liquid film stream.The coefficients showed opposite trend to the empirical correlation reported for laminar film flow on a straight smooth tube in a refrigeration mode in the past work.The fact can be caused due to a turbulent promotion effect of the liquid in a spiral tube.
