一种喷射器膨胀直接供液制冷循环及性能分析

Performance characteristics of a direct liquid feeding ejector expansion refrigeration cycle

很多环保制冷剂如(R1234ze(E))具有蒸发压力低的特点,影响了其制冷性能。提出了将两相喷射器作为膨胀部件,将汽液分离后的纯液体供给蒸发器的直接供液式喷射器膨胀制冷循环(EERC)。以汽车空调系统为例,研究了循环COP与单位容积制冷量,结果表明采用R1234ze(E)的EERC循环相对于采用R134a的传统循环(TRC)COP提升在22%以上,并且容积制冷量也得到大幅提升,与采用R134a的容积制冷量的差距从33%左右减小到了6%—12%;在高冷凝温度和低蒸发温度工况下,性能改善更加明显。直接供液式EERC无论是直接用来替代现有制冷循环,还是用在环保制冷剂特别是低压环保制冷剂替代传统制冷剂的场合都是一个很好的选择。

Performance of many environmentally friendly refrigerants（ eg. R1234ze（ E）） in refrigeration cycle is greatly affectedbyits low evaporating pressure. A new cycle called direct-liquid-feeding ejector expansion refrigeration cycle（ EERC） was proposed,in which a two-phase ejector works as the only expansion device and totallyliquid refrigerant rather than two phase one was fed to the evaporator. Taking automotive air-conditioner for example,the COP improvement of the EERC using R1234ze（ E） as refrigerant over the traditional cycle（ TRC） using R134 a as refrigerant can be obtained by more than 22% at giving conditions. Besides,volumetric cooling capacity gap between them can be obviously reduced from about 33% to6%-12%. According to the result,the performance will be much better in the cases of higher condensing temperature and lower evaporating temperature. It is concluded that the direct-liquid-feeding ejector expansion refrigeration cycle could be a good choice when using environmentally friendly refrigerants especially with lower evaporatingpressure ones toreplace traditional refrigerants.