The absorption-compression heat pump （ACHP） has been considered as an effective approach to recover and utilize low-grade heat sources. In the present study, the first and second law thermodynamic analyses of the AC...The absorption-compression heat pump （ACHP） has been considered as an effective approach to recover and utilize low-grade heat sources. In the present study, the first and second law thermodynamic analyses of the ACHP with NH3/H20 as working fluid were performed. Thermodynamic properties of each point and heat transfer rate of each component in the cycle under basic operation conditions were calculated from the first law analysis. Following the second law of thermodynamics, the entropy generation of each component and the total entropy generation of the system were obtained. The effect~ of the heating temperature, heat source temperature, and compression ratio on the coefficient of performance （COP） and the total entropy generation （ STot ） of the system were examined. The results show that the increase in COP corresponds to a decrease in STot, and vice versa; besides, for certain operating conditions, an optimum compression ratio in the NH~/H20 ACHP exists.展开更多
The study of the phase equilibrium characteristics of CO_(2)-ionic liquids(ILs)as new absorption-compression type refrigeration working pairs is of great importance.Three kinds of ILs,i.e.,[emim][FAP],[bmim][FAP]and[h...The study of the phase equilibrium characteristics of CO_(2)-ionic liquids(ILs)as new absorption-compression type refrigeration working pairs is of great importance.Three kinds of ILs,i.e.,[emim][FAP],[bmim][FAP]and[hmim][FAP],were chosen as potential absorbents.The solubility of CO_(2)in these ILs was measured experimentally within 0 to 5.0 MPa at temperatures of 293.15 K to 333.15 K,and the effects of temperature,pressure,IL anion and cation structure and stirring action on CO_(2)solubility were also discussed and analyzed.The results showed that the longer alkyl chains in an identical IL family,the alkyl fluoride group in IL anions and the stirring action by a magnetic stirrer had positive effects on the solubility of CO_(2).In the three ILs,[hmim][FAP]possessed the best performance for CO_(2)absorption;the solubility of CO_(2)reached 0.7641 at a pressure of 5 MPa and temperature of 293.15 K,the maximum solubility measured in this work.The CO_(2)-[hmim][FAP]binary mixture is recommended as a potentially applicable working pair for CO_(2)absorption-compression refrigeration systems.展开更多
基金National Key Technologies R&D Program of China(No. 2012BABZ︱2B01)National Natural Science Foundation of China(No. 51106161)Innovation Foundation of President of Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences(No. 0907r7)
文摘The absorption-compression heat pump （ACHP） has been considered as an effective approach to recover and utilize low-grade heat sources. In the present study, the first and second law thermodynamic analyses of the ACHP with NH3/H20 as working fluid were performed. Thermodynamic properties of each point and heat transfer rate of each component in the cycle under basic operation conditions were calculated from the first law analysis. Following the second law of thermodynamics, the entropy generation of each component and the total entropy generation of the system were obtained. The effect~ of the heating temperature, heat source temperature, and compression ratio on the coefficient of performance （COP） and the total entropy generation （ STot ） of the system were examined. The results show that the increase in COP corresponds to a decrease in STot, and vice versa; besides, for certain operating conditions, an optimum compression ratio in the NH~/H20 ACHP exists.
基金supported by the National Natural Science Foundation of China(No.51676129)。
文摘The study of the phase equilibrium characteristics of CO_(2)-ionic liquids(ILs)as new absorption-compression type refrigeration working pairs is of great importance.Three kinds of ILs,i.e.,[emim][FAP],[bmim][FAP]and[hmim][FAP],were chosen as potential absorbents.The solubility of CO_(2)in these ILs was measured experimentally within 0 to 5.0 MPa at temperatures of 293.15 K to 333.15 K,and the effects of temperature,pressure,IL anion and cation structure and stirring action on CO_(2)solubility were also discussed and analyzed.The results showed that the longer alkyl chains in an identical IL family,the alkyl fluoride group in IL anions and the stirring action by a magnetic stirrer had positive effects on the solubility of CO_(2).In the three ILs,[hmim][FAP]possessed the best performance for CO_(2)absorption;the solubility of CO_(2)reached 0.7641 at a pressure of 5 MPa and temperature of 293.15 K,the maximum solubility measured in this work.The CO_(2)-[hmim][FAP]binary mixture is recommended as a potentially applicable working pair for CO_(2)absorption-compression refrigeration systems.
