R410A单工质复叠制冷系统高低温变频[火用]分析

Exergy Analysis of High and Low Temperature Conversion of R410A Single-medium Cascade Refrigeration System

针对R410A单工质复叠制冷系统进行了运行特性及能量分析,采用常规[火用]分析方法计算了各组成部件及整个系统的[火用]损和[火用]效率。结果表明,分别增大高温级和低温级压缩机频率,系统的制冷量均增大,系统制冷系数COP均先增大后减小,低温蒸发器、低温压缩机和高温压缩机的[火用]损均较高,是系统薄弱部位所在。当高低温级压缩机频率高于200 Hz时,继续增大压缩机频率,[火用]损增加速率变大,[火用]效率降低,系统制冷系数COP开始下降。相比于高温级压缩机频率,低温级压缩机频率对系统性能的影响更大。

In this paper,the operating characteristics and energy of R410A single-medium cascade refrigeration system are analyzed.Exergy loss and exergy efficiency of each component and the whole system were analyzed by conventional exergy analysis method.The results showed that when the frequency of high and low temperature compressors was increased,the cooling capacity of the system was increased,and the COP of the system increased firstly and then decreased.Exergy loss of low-temperature evaporator,low-temperature compressor and high-temperature compressor is high,which is the weak part of the system.When the frequency of high and low temperature stage compressor exceeds200 Hz,the frequency of compressor continues to increase,the rate of exergy loss increases,exergy efficiency decreases,and COP of the system performance parameter starts to decline.The low-temperature compressor frequency has a greater impact on the system performance than the high-temperature compressor frequency.