技术中心

【关键词】 CO2跨临界循环; 双级压缩; 高压膨胀机; 低压膨胀机; 性能; 热力学; 【英文论文关键词】 CO2 trans-critical cycle two stage compression high pressure expander low pressure expander performance thermodynamics; 【论文摘要】 CO2跨临界循环的效率较低,采用双级压缩和膨胀机是提高系统性能系数(COP)的有效途径。本文通过建立模型,分析比较了带节流阀与带高低压膨胀机CO2跨临界双级压缩循环的性能。结果表明:带节流阀与带高低压膨胀机CO2跨临界双级压缩循环的最佳中间压力并不是高低压的几何平均值;在一定的气体冷却器出口温度下,带高低压膨胀机循环的最大COP比带节流阀循环可提高30%;优化设计带高低压膨胀机CO2跨临界双级压缩循环系统时,应优先考虑等熵效率高的低压膨胀机,且中间冷却应采用完全冷却型式。 【英文论文摘要】 The efficiency of trans-critical cycle taking natural working fluid CO2 as refrigerant is relatively low, effective way to improve the coefficient of performance (COP) are applying the two stage compression cycle or replacing the throttling valve by an expander. Performances of the CO2 trans-critical two stage compression cycle with high and low pressure expanders are compared with that of the cycle with throttling valves by the models we established. Results indicate that the optimum inter-stage pressure i