过热和过冷对系统的影响分析

Exergy Analysis for the Ammonia Vapor Compression Refrigeration Systems with superheating and super cooling

通过对定环境温度条件下的高温冷库中的氨蒸汽压缩系统进行分析,利用线性拟合的方法对氨的物性进行模拟,并对系统过冷度和过热度变化时,制冷系统的各部件的损失和系统的效率进行计算分析,得出在冷库氨蒸汽压缩系统中的蒸发器中的损失最大,压缩机和冷凝器次之的结果。提出定环境温度条件下,由于过热度越大,对系统越不利,过冷度越大,对系统越有利,提高系统性能可从减少过热度增大过冷度着手。

This paper presents a detailed exergy analysis of an actual ammonia vapor compression refrigeration cycle in the cold store on constant dead state temperature, using linear method of fitting the physical properties of ammonia to simulate, changing with superheating degree and super cooling degree. A computational model has been developed for computing exergy destruction of the various components of the refrigeration system, exegetic efficiency of the system, coefficient of performance. The results indicate that the exergy destruction in the evaporator is highest, followed by the compressor and condenser. Proposed to improve the performance of the ammonia vapor compression system in the cold store, we must reduce superheating degree and raise super cooling degree.