【摘要】 为了提高CO2跨临界制冷系统的性能,建立了单级膨胀机循环与4种不带膨胀机的两级压缩循环的数学 模型,并进行了性能计算．结果显示,当膨胀机的效率达到60％时,在给定的气体冷却器出口温度以及蒸发温度范 围内(低于-10 ℃时除外),单级膨胀机循环的性能系数高于两级压缩循环的性能系数．当蒸发温度低于-10℃ 时,带中冷器的两级循环的性能占优势．另外,4种两级压缩循环的排气温度都低于单级膨胀机循环的排气温度．更多还原

【Abstract】 In order to improve the performance of the transcritical CO2-refrigeration system, the mathematical models for the single-stage expander cycle and for four types of two-stage compression cycles without expanders were developed and their performance was analyzed. The results showed that the coefficient of the performance of the single-stage expander cycle, when its expander efficiency achieving 60% , was higher than the coefficients of the four two-stage compression cycles within certain ranges of the gas cooler outlet temperatures and the evaporation temperatures (except those less than - 10 ℃). When the evaporation temperature was less than - 10℃, the two-stage cycle with inter-cooler(IC) outperformed the other options. In addition, the discharge temperatures of the four two-stage compression cycles were lower than the temperature of the single-stage expander cycle.更多还原