自然工质CO2在风冷热泵复合冷凝系统中换热特性的时间序列分析

Time Series Analysis of Compound Condensation Process(CCP)in Air-cooled Heat Pump System with Natural Refrigerant CO2

为研究自然工质CO2在风冷热泵复合冷凝系统中的热力学特性,引入有限时间热力学与■分析方法,采用MATLAB/SIMULINK进行仿真,建立了自然工质CO2在风冷热泵复合冷凝系统的时间序列模型,模拟和测试了自然工质CO2在风冷热泵复合冷凝系统中的热力学特性,并与自然工质CO2单制冷系统及原风冷热泵复合冷凝系统的性能做了对比。结果表明:制热水模式下,两个风冷热泵复合冷凝系统的■效率都随用户要求的卫生热水水温温度升高而降低;达到用户需要水温53℃时,自然工质CO2风冷热泵复合冷凝系统卫生热水机组运行约需18 min,而R22风冷热泵复合冷凝系统约为30 min。复合冷凝模式下自然工质CO2风冷热泵系统的COP(coefficient of performance)为4.7左右,比R22风冷热泵系统略高。

In order to avoid the aggravation of greenhouse effect,the application of natural refrigerants in refrigeration system is a trend.In order to study the thermodynamic characteristics of natural refrigerants in air-cooled heat pump compound condensing system,the finite time thermodynamic analysis and exergy analysis methods are employed to establish the air cooled heat pump CCP simulation model,with the natural refrigerant CO2.And the simulation tool is MATLAB/SIMULINK software.The thermodynamic characteristic of the two CCP systems are studied:the subject is a air-cooled heat pump unit.The result shows that on the sanitary hot water mode,the exergy efficiency declines according to the sanitary hot water temperature that the user demand;to reach the temperature of the sanitary hot water tank 53℃,the CO2 compound condensation system of air cooled heat pump need about 18 min,while the R22 compound condensation system of air cooled heat pump is about 30 min.The COP of the CO2 air cooled heat pump system is about 4.7 at the compound condensation mode,and it is higher than the R22 air cooled heat pump system.