采用非共沸工质机械过冷跨临界CO_(2)热泵供暖性能分析  

Performance of Transcritical CO_(2) Air-source Heat Pump Heating System with Mechanical Subcooling Using Zeotropic Refrigerant

作　　者：代宝民 张鹏 刘圣春[1] 王铭慧 孙悦桐 王嘉豪 徐田雅慧 肖鹏 Dai Baomin;Zhang Peng;Liu Shengchun;Wang Minghui;Sun Yuetong;Wang Jiahao;Xu Tianyahui;Xiao Peng(Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, 300134, China;Danhua Hongye Refrigeration Technology Co., Ltd., Tianjin, 300354, China)

机构地区：[1]天津商业大学天津市制冷技术重点实验室,天津300134 [2]天津市丹华宏业制冷技术有限公司,天津300354

出　　处：《制冷学报》2021年第6期51-58,共8页Journal of Refrigeration

基　　金：国家自然科学基金(51806151)资助项目。

摘　　要：本文提出采用非共沸工质的机械过冷跨临界CO_(2)热泵供暖系统,并建立系统热力学模型,与采用纯质的机械过冷跨临界CO_(2)热泵系统进行对比。结果表明:在环境温度为-12℃、用户供回水温度为65/40℃条件下,采用大温度滑移非共沸工质R1234ze(E)/R601(60/40)时,系统COP高达2.45,相对采用纯质最高提升13.82%。采用非共沸工质可有效降低系统排气压力并获得较大过冷度,减小节流不可逆损失。使用R290/R601(70/30)时,最优排气压力可降低27.85%。非共沸工质的使用可有效改善过冷过程的温度匹配,使用R1234ze(E)/R601(60/40)时系统火用效率相对纯质最高提升14.09%。较大的温度滑移及合理的温焓曲线凹凸性是机械过冷CO_(2)热泵系统非共沸工质选取的两个重要原则,推荐选用R1234ze(E)/R601(60/40)。In this study,a mechanical subcooling transcritical CO_(2) heat pump heating system using a zeotropic refrigerant is proposed.A thermodynamic model is developed for this system and compared with that using a pure refrigerant.The results indicate that the coefficient of performance employing R1234ze(E)/R601(60/40)with a large temperature glide is up to 2.45,which is 13.82%higher than that of the pure component,at an ambient temperature of-12℃,and supply/return water temperatures of 65℃/40℃.The discharge pressure of the CO_(2) system can be efficiently reduced,and a higher subcooling degree is achieved using a zeotropic refrigerant;hence,the throttling irreversible loss decreases.The optimal discharge pressure is reduced by 27.85%using R290/R601(70/30).The temperature match in the subcooling process can be efficiently improved,and the exergy efficiency is up to 14.09%higher than that of the pure refrigerant component when using R1234ze(E)/R601(60/40).The relatively large temperature glide and suitable concave-convex characteristic of the temperature-enthalpy curve are the two key principles for zeotropic refrigerant selection used for CO_(2) heat pump systems with mechanical subcooling.Finally,the utilization of R1234ze(E)/R601(60/40)is recommended.

关 键 词：供暖 热泵 机械过冷 温度匹配 非共沸工质 CO_(2) 

分 类 号：TB611[一般工业技术—制冷工程] TQ051.5[化学工程]