CAJ | 학술논문

由于CFCs和HCFCs人工合成制冷剂破坏大气臭氧层,并产生温室效应,因此用自然工质替代合成工质越来越受到国内外制冷界的重视.文章对环保型CO_2制冷工质进行了综合评价,并利用热力学原理建立模型,分析了CO_2跨临界带膨胀机制冷循环的性能.结果表明:与CO_2跨临界带节流阀制冷循环相比,CO_2跨临界带膨胀机制冷循环明显提高了系统的性能系数(COP).同时在保持压缩机排气压力和膨胀机等熵效率一定时,CO_2跨临界带膨胀机制冷循环系统COP随着气体冷却器出口温度的增加而逐渐降低,但随着蒸发温度的增加而快速增加.在实际系统设计过程中,应综合考虑以上影响因素,以使系统设计最优化.
유우CFCs화HCFCs인공합성제랭제파배대기취양층,병산생온실효응,인차용자연공질체대합성공질월래월수도국내외제랭계적중시.문장대배보형CO_2제랭공질진행료종합평개,병이용열역학원리건립모형,분석료CO_2과림계대팽창궤제랭순배적성능.결과표명:여CO_2과림계대절류벌제랭순배상비,CO_2과림계대팽창궤제랭순배명현제고료계통적성능계수(COP).동시재보지압축궤배기압력화팽창궤등적효솔일정시,CO_2과림계대팽창궤제랭순배계통COP수착기체냉각기출구온도적증가이축점강저,단수착증발온도적증가이쾌속증가.재실제계통설계과정중,응종합고필이상영향인소,이사계통설계최우화.
Synthetic refrigerants such as CFCs and HCFCs deplete ozone and cause greenhouse effect. CO_2 as a natural working fluids, is receiving more and more attention in the refrigeration field. The comprehensive evaluation of environment-friendly CO_2 refrigeration working fluids is carried out. The performances of CO_2 transcridcal refrigeration cycle are analyzed by establishing the thermodynamics model. Results indicate that the maximum coefficient of performance (COP) of the cycle with an expander is higher than that of the cycle with a throttling valve. At the optimal discharge pressure of the compressor and given expander iso-entropy efficiency, COP of CO_2 transcritical refrigeration cycle with an expander increases with the decrease of outlet temperature of gas cooler, but increases quickly with the increase of evaporation temperature. For the optimization design of the CO_2 transcritical refrigeration cycle with an expander, the major factors affecting the COP of the system should be considered.