CO_(2)气液两相小型膨胀机的研究进展  

Research Progress of Small-scale CO_(2)Two-phase Expanders

作　　者：秦鹏伟 马一太[1] 党超镔 刘楷 李敏霞[1] 霍文明 王派[1] Qin Pengwei;Ma Yitai;Dang Chaobin;Liu Kai;Li Minxia;Huo Wenming;Wang Pai(Thermal Energy Research Institute,Key Laboratory of Efficient Utilization of Low and Medium Grade Energy,MOE,School of Mechanical Engineering,Tianjin University,Tianjin,300072,China;School of Engineering,University of Fukui,Fukui,9100017,Japan;EUROJOY Ice&Snow Investment Management(Beijing)Co.,Ltd.,Beijing,100040,China)

机构地区：[1]天津大学机械工程学院、中低温热能高效利用教育部重点实验室天津大学热能研究所,天津300072 [2]福井大学工学系,福井9100017 [3]欧悦冰雪投资管理(北京)有限公司,北京100040

出　　处：《制冷学报》2023年第1期24-34,共11页Journal of Refrigeration

基　　金：国家重点研发计划(2021YFF0306801,2021YFF0306805)资助项目;中国制冷学会课题项目(CAR20190701)资助。

摘　　要：随着国际社会环境意识的提高,臭氧层破坏、温室效应问题受到持续广泛的关注,越来越多的学者将注意力集中于环保制冷剂。CO_(2)因简单易得、安全可靠、传热性能和流动性好等优点受到重视。本文对CO_(2)气液两相小型膨胀机的研究进展进行分析和总结,发现在循环中将节流阀换成CO_(2)膨胀机可有效提高系统的制冷效率,经过计算得到带膨胀机跨临界CO_(2)循环的制冷、制热效率分别比R134a循环高6.9%、4.6%,比带节流阀的循环高25.76%、16.17%;CO_(2)膨胀机的等熵效率越高,系统制冷、制热效率越大,若CO_(2)膨胀机的等熵效率大于32%,则带CO_(2)膨胀机的系统性能优于带回热器循环的系统性能。不同CO_(2)膨胀机由于结构不同导致效率、泄漏和摩擦损失不同,活塞式、转子式等膨胀机结构简单,但同时泄漏损失也较大;滑片式、旋转叶片式、涡旋式等膨胀机效率得到了很大提高,但其结构较为复杂,制造难度大,生产成本较高;同时对当前存在的一些问题提出了解决办法,如进行合理的设计减小泄漏与摩擦损失、将压缩功提供给压缩机、在膨胀过程中加入其他气体以及设计可调节膨胀比的CO_(2)膨胀机。目前CO_(2)膨胀机的研究基本集中于实验室,在工程中应用较少。因此未来应以实验和理论相结合,进一步研究CO_(2)膨胀机效率提升、关键零部件技术开发等问题。With the increased awareness in the international community,the problems of ozone depletion and greenhouse effect have received extensive attention,more and more scholars are focusing on environmental-friendly refrigerants.CO_(2)demonstrated its value in terms of simplicity,availability,safety,reliability,and good heat transfer performance.This paper analyzes and summarizes the research progress of small-scale CO_(2)gas-liquid two-phase expanders.It is found that replacing the throttle valve with a CO_(2)expander in the cycle can effectively improve refrigeration efficiency.The cooling and heating efficiency of the cycle is 6.9%and 4.6%higher than that of the R134a cycle,and 25.76%and 16.17%higher than that of the cycle with a throttle valve,respectively.The higher the isentropic efficiency of the CO_(2)expander,the greater the system efficiency.As long as the isentropic efficiency of the expander is greater than 32%,the performance of the system with a CO_(2)expander is better than that with a regenerator.Different CO_(2)expanders have different efficiency,leakage,and friction loss due to their different structures.Piston type,rotor type,and other expanders have simple structures,while their leakage loss is relatively large.The efficiency of the sliding vane type,rotary vane type,and scroll type expander has been greatly improved,but their structure is more complicated,leading to more complicated manufacturing and increased production costs.The compression work is supplied to the compressor,increasing the flow rate during the expansion process,which requires designing a CO_(2)expander with an adjustable expansion ratio.At present,the research of CO_(2)expanders is basically concentrated in the laboratory,and this technology has not been commercialized yet.Therefore,the future development direction should combine experiments and theory to further study the efficiency improvement of CO_(2)expanders and the development of key components technology.

关 键 词：跨临界循环 膨胀机 膨胀功 等熵效率 泄漏 CO_(2) 

分 类 号：TB611[一般工业技术—制冷工程] TB653