CAJ | 학술논문

双级压缩是提高CO_2跨临界制冷循环性能系数COP的有效途径,且中间完全冷却形式的性能优于中间不完全冷却形式.对于中间完全冷却CO_2跨临界双级压缩节流循环,节流形式有一次节流(STDC循环)和两次节流(DTDC循环).分析了高压压力和气体冷却器出口温度对STDC循环和DTDC循环的性能影响,并与CO_2跨临界单级压缩(STSC)节流循环进行了比较.结果表明:在给定条件下,DTDC循环的COP值最大、STDC循环的最优高压压力值最高;随着气体冷却器出口温度的升高,3个循环的最大COP均减小,最优高压压力均升高,压缩机的等熵效率均降低.对于DTDC和STDC循环,最优中间压力值偏离高压压力与低压压力的几何平均值,但是对系统的性能系数影响不大.
쌍급압축시제고CO_2과림계제랭순배성능계수COP적유효도경,차중간완전냉각형식적성능우우중간불완전냉각형식.대우중간완전냉각CO_2과림계쌍급압축절류순배,절류형식유일차절류(STDC순배)화량차절류(DTDC순배).분석료고압압력화기체냉각기출구온도대STDC순배화DTDC순배적성능영향,병여CO_2과림계단급압축(STSC)절류순배진행료비교.결과표명:재급정조건하,DTDC순배적COP치최대、STDC순배적최우고압압력치최고;수착기체냉각기출구온도적승고,3개순배적최대COP균감소,최우고압압력균승고,압축궤적등적효솔균강저.대우DTDC화STDC순배,최우중간압력치편리고압압력여저압압력적궤하평균치,단시대계통적성능계수영향불대.
Two-stage compression is an effective method to improve the coefficient of performance(COP)of trans-critical refrigeration cycle of CO_2,and COP of a complete inter-cooling mode is higher than that of an incomplete mode.For the trans-critical throttling cycle of CO_2 in a two-stage compression with complete inter-cooling,the throttling cycle can be divided into two types,single-throttling(STDC)cycle and double-throttling(DTDC)cycle.For these two cycles,the effects of outlet temperature of gas-cooler and heat rejection pressure on the COP are investigated,and compared with those in a single-stage compression(STSC).The results indicate that under given condition,DTDC cycle presents the maximum COP,while the STDC cycle presents the highest optimum high pressure.For the three cycles,increase in gas-cooler outlet temperature decreases the COP,increases the optimum high pressure,and decreases the isentropic compression efficiency.The optimum inter-cooling pressure for STDC cycle and DTDC cycle deviates from the geometric mean of high pressure and low pressure,but this has little effect on the system performance.