中高温热泵两级循环方式性能分析  

Analysis of the Performance of a High Temperature Heat Pump in a Two-stage Cycle

作　　者：刘昭云[1] 王怀信[1] 郭东奇[1] 

机构地区：[1]天津大学机械工程学院,天津300072

出　　处：《热能动力工程》2013年第5期471-476,550,共6页Journal of Engineering for Thermal Energy and Power

基　　金：天津市科技计划资助项目(10ZCKFGX01700)

摘　　要：在冷凝温度70～130℃、循环温升40～65℃的工况范围内,以HFC245fa为工质,考察了单、双级节流中间不完全冷却与完全冷却等4种两级循环方式下的中高温热泵循环性能。结果表明:4种两级循环方式下COP(综合性能系数)均较单级循环明显提高,其中两级节流中间不完全冷却方式带来的COP改善幅度最大,为12.04%～33.25%;COP改善幅度随循环温升增大而单调上升、随冷凝温度升高先减小后增大。两级循环方式还有助于降低压缩机排气温度,对于以湿流体为工质的情形,效果尤为显著。综合考虑性能收益与系统代价,对中高温热泵引入两级循环方式具有可行性。When the condensing temperature is in a range from 70 ℃ to 130 ℃ and the temperature rise of the cycle from 40 ℃ to 65 ℃,with HFC245fa serving as the working medium,investigated was the circulation performance of a medium and high temperature heat pump under four modes of a two-stage cycle,namely,incomplete and complete intercooling in a single-and two-stage throttle. It has been found that under the foregoing four modes of the two-stage cycle,the COPs are all obviously higher than that of a single stage cycle,among them,the incomplete intercooling mode in a two-stage throttle can result in a maximal increment in COP,reaching 12. 04%33. 25%. The COP increment will monotonically go up with an increase of the circulation temperature rise,and first decrease and then increase with an increase of the condensate temperature. The two-stage circulation mode can also contribute to lowering the exhaust gas temperature of the compressor and when a wet fluid serves as the working medium,such an effectiveness will be especially remarkable. When the performance benefit and systematic cost are taken into account in a comprehensive way,to introduce the two-stage circulation mode into medium and high temperature heat pumps is feasible.

关 键 词：中高温热泵 两级循环 c0P 排气温度 

分 类 号：TB615[一般工业技术—制冷工程]