Thermodynamic Comparison Analysis on CO_2 Transcritical Reverse Cycles with IHX or Expander

作     者：管海清 马一太 杨俊兰 李敏霞 

作者机构：School of Mechanical Engineering Tianjin University Tianjin 300072 China 

出 版 物：《Transactions of Tianjin University》 (天津大学学报（英文版）)

年 卷 期：2005年第11卷第2期

页      面：110-114页

核心收录：

学科分类：080701[工学-工程热物理] 08[工学] 0807[工学-动力工程及工程热物理] 

基　　金：SupportedbyNationalNaturalScienceFoundationofChina(No.50476060)andSpecializedResearchFundfortheDoctoralProgram ofHigherEducation(No.D0200105) 

主　　题：CO_2 transcritical reverse cycle internal heat exchanger expander coefficient of performance 

摘      要：To improve the coefficient of performance （COP） of CO2 transcritical reverse cycle and determine the most efficient cycle, comparison analysis on （single-and） two-stage CO2 transcritical cycles with internal heat exchanger （IHX） or expander is presented adopting the principle of thermodynamics. Results indicate that the COP of four cycles,namely single-stage compression with IHX （SI）, single-stage compression with expander （SE）, two-stage compression with IHX （TI） and two-stage compression with expander （TE）, can be ranged as TESETISI. It presents that adopting an expander to recover expansion power is the primary method to improve the COP of CO2 transcritical reverse cycle if the efficiency of the expander is up to a certain value. Under supposed operating condition, where the outlet temperature of gas cooler is 35 ℃ and the evaporating temperature is 5 ℃, the COP of TE cycle is about 4200 higher than that of SI cycle when the expander efficiency is 0.6 and the degree of superheat of IHX is 15 ℃. Therefore TE cycle is the most recommendatory one and it is better to adopt TE in those high-cooling capacity systems because its technology cost will be higher.