喷射/压缩制冷循环的能量与[火用]分析

Energy and exergy analyses of ejector/compression refrigeration cycle

为发现影响喷射/压缩制冷循环的关键部件提高循环性能,本文对该循环进行模拟分析。引入涉及关键尺寸的两相喷射器等面积混合模型和压缩机半经验模型,对R1234ze为工质的喷射/压缩制冷循环进行能量和[火用]分析。结果表明:喉部面积比对喷射器及循环的性能有重要影响,存在一个最优值。随着冷凝温度的上升,机械性能系数COPm、[火用]效率降低,总[火用]损增加。随着蒸发温度的上升,COPm增加,[火用]效率和总[火用]损降低。部件[火用]损排前三位的分别是压缩机、冷凝器和蒸发器,减少这些部件的损失是提升循环性能的关键。

To find out the key components that affect ejector/compression refrigeration cycle and improve the cycle performance,this paper carried out simulation analysis of the cycle.A two-phase ejector constant-area mixing model with critical dimensions and a compressor semi-empirical model were introduced to conduct energy and exergy analysis on the cycle using R1234 ze.The results indicate that the throat area ratio,has an optimal value,plays a key role on the performance of ejector and cycle.With a rise in condensation temperature,mechanical coefficient of performance COPm and exergy efficiency decrease,but total exergy destruction increases.COPm increases while exergy efficiency and total exergy destruction decrease as evaporation temperature rises.The exergy destruction in compressor,condenser and evaporator are in the top three,thus reducing losses in them is the key to improve performance of the cycle.