单级压缩或双级压缩制冷的技术经济分析

通过理论计算,比较了典型制冷循环单级或双级压缩的特性。同时,从工程实用的角度,对采用单级压缩还是双级压缩两种方案进行技术经济分析。结果表明:在压缩比小于8的工况下,与单级压缩制冷比较,采用双级压缩时理论制冷系数提高4.16%~7.08%。在冷凝温度35℃,蒸发温度-15℃工况下,采用双级压缩实际节能率达到18.4%。在压缩比大于8的工况下,采用双级压缩时理论制冷系数比单级提高了9.01%~10.85%,排气温度可降低33℃~44℃,实际运行的节能率可达37.7%。因此,在低压缩比下采用双级压缩的方案值得大力推广。

Performance analysis of single-stage compression or two-stage compression refrigerating cycle

The paper compares the performance of single-stage and two-stage compression refrigeration cycle based on theoretical calculation. From the engineering application view, the performances of two schemes are calculated and analyzed. The results show that the theoretical COPs of two-stage compression increase 4.16%-7.08% compared with the single-stage compression when the compression ratio is less than 8. the actual energy saving will be 18.4% under condensing temperature 35℃ and evaporating temperature -15℃. The theoretical COPs of two-stage compression increase 9.01%-10.85% and discharge temperatures will drop 33℃ -44℃ compared with the single-stage compression when the compression ratio is more than 8. The actual energy saving can reach 37.7%. Therefore, the two-stage compression should be promoted when the compression ratio is less than 8.