为准确描述开式简单布雷顿制冷循环的热力学性能,根据工质流动机理的一致性,采用与开式布雷顿正循环研究类似的研究方法,建立了考虑压降不可逆性的开式简单布雷顿制冷循环的热力学模型,导出了制冷率和制冷系数等性能参数与压缩机进口相对压降的函数关系,并分析了循环的热力学性能。结果表明,压缩机消耗功率、高温侧换热器换热率、膨胀机输出功率、制冷率和排气损失引起的热流率都与质量流率成正比,存在最佳的压缩机进口相对压降使循环制冷率最大。
To accurately describe thermodynamic performance of open simple Bretton refrigeration cycle, according to the consistency of the refrigerant flow mechanism, this paper constructs the thermodynamic model for open simple Bretton refrigeration cycle regarding the pressure drop irreversibility. Then it derives the functional relation between the performance parameters (e. g. cooling rate and coefficient) and the relative pressure drop at the compressor inlet, and it analyzes the thermodynamic performance of the cycle. Results indicate that heat flow rate is proportional to the mass flow rate no matter whether it is caused by the compressor power consumption, heat transfer rate of high temperature-side heat exchanger, expander output power, refrigeration rate or exhaust losses. The maximum circulation cooling rate can be achieved with the best compressor inlet relative pressure drop value.