CO_2跨临界循环膨胀特性及机理  

Characteristics and Mechanism of Expansion for Carbon Dioxide Transcritical Cycle

作　　者：魏东[1] 马一太[1] 李丽新[1] 苏维诚[1] 吕灿仁[1] 

机构地区：[1]天津大学热能研究所,天津300072

出　　处：《热科学与技术》2002年第1期5-10,共6页Journal of Thermal Science and Technology

基　　金：国家自然科学基金资助项目 (5 98760 2 8) ;高等学校博士学科点专项科研基金资助课题 (D0 2 0 0 10 5 )

摘　　要：介绍了采用膨胀机的 CO2 跨临界循环的系统流程及典型工况 ,详细分析了膨胀中经历的亚稳态过程的成因和机理 ,指出气化的滞后对系统的危害 ,并对相变膨胀过程中的成核现象进行了热力学分析。在此基础上 ,结合 CO2 超临界膨胀过程的特点 ,阐明了气液相变介质中声速的确定方法 ,认为 CO2This paper describes the flow chart and typical working condition of the CO 2 transcritical cycle with the expander. The cause and mechanism of metastable expansion process, the damage due to gasification delay and the nucleation in phase transition are analyzed. Based on those analysis, the speed of sound in the liquid\|vapor two phase fluid with phase transition is deduced with respect to the special characteristics of the CO 2 super\|critical expansion process. Finally,this paper also shows that it is feasible to use the quasistate theories of the traditional thermodynamics for the CO 2 super critical expansion process.

关 键 词：CO2跨临界循环 膨胀过程 亚稳态 相变 二氧化碳 空调 制冷工质 

分 类 号：TB657.2[一般工业技术—制冷工程]