非共沸工质辅助过冷CO_(2)冷热联供系统的热力学性能分析  

Thermodynamic performance analysis of combined cooling and heating system based on combination of CO_(2) with the zeotropic refrigerant assisted subcooled

作　　者：代宝民 王启龙 刘圣春[1] 张佳宁 李鑫海 宗凡迪 DAI Baomin;WANG Qilong;LIU Shengchun;ZHANG Jianing;LI Xinhai;ZONG Fandi(Tianjin Key Laboratory of Refrigeration Technology,Tianjin University of Commerce,Tianjin 300134,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

出　　处：《化工学报》2023年第S01期64-73,共10页CIESC Journal

基　　金：国家重点研发计划项目(2021YFE0116100);国家自然科学基金项目(51806151);生态环境部对外合作与交流中心资助项目(C/Ⅲ/S/19/052);天津市自然科学基金项目(20JCQNJC00600)。

摘　　要：为满足食品加工领域对高温消毒和冷冻的双重需求,提出了基于非共沸工质辅助过冷的跨临界CO_(2)冷热联供系统,辅助循环采用低GWP非共沸工质,充分利用冷凝热及气体冷却器放热生产高温热水,并同时进行食品冷冻。以COP为目标函数,对混合工质的组元、组分进行分析,对系统的排气压力和过冷度的影响进行优化。结果表明系统存在最优排气压力和最优过冷度,大温度滑移工质相对小温度滑移工质和纯工质能够显著提升系统性能,降低排气压力。采用R32/R1234ze(Z)(0.4/0.6)时COP最高为3.45,相对纯工质R32和R1234ze(Z)分别提高4.77%和5.15%,排气压力降低0.958 MPa和0.910 MPa。CO_(2)循环对系统整体起主导作用。采用非共沸工质可提高系统[火用]效率。可为推广CO_(2)制冷热泵技术的应用提供理论参考。In order to meet the requirements of uperization and freezing in the field of food processing,two-stage compression transcritical CO_(2) cooling and heating system with dedicated mechanical subcooling using zeotropic refrigerant is proposed.The subcooling cycle that uses low global warming potential(GWP)zeotropic refrigerant makes full use of the heat of the condenser and gas cooler to produce hot water.Additionally,cooling capacity is also generated for food freezing.Setting the coefficient of performance(COP)as the objective function,the component,mass fraction,discharge pressure and subcooling degree of the system are analyzed and optimized.The results show that the system has optimal discharge pressure and subcooling degree.The large temperature glide working fluid can significantly improve the system performance and reduce the discharge pressure comparing with the small temperature glide and pure working fluid.The highest COP of 3.45 is achieved when R32/R1234ze(Z)(0.4/0.6)is utilized,which is 4.77%and 5.15%higher than that of pure R32 and R1234ze(Z),and the discharge pressure drops by 0.958 MPa and 0.910 MPa,respectively.The CO_(2) cycle plays a dominant role for the overall system.The system exergy efficiency can also be improved by using zeotropic refrigerant.This study can provide a theoretical reference to widen the application of CO_(2) refrigeration and heat pump technology.

关 键 词：非共沸工质 跨临界CO_(2) 机械过冷 冷热联供 大温度滑移 双级压缩 

分 类 号：TK114[动力工程及工程热物理—热能工程]