双级压缩离心式冷水机组补气控制方案

Intermediate suction control scheme of two-stage compression centrifugal chiller

合理的中间补气控制对提高双级压缩离心式冷水机组的性能及安全运行具有极其重要的意义。本文对带有中间补气的双级压缩离心式冷水机组的理论循环进行分析,试验研究在给定导叶开度下,不同补气阀开度对双级压缩离心式冷水机组的制冷能力、功耗及能效比的影响,验证补气阀开度对机组的性能和安全运行的影响,最终得到匹配双级压缩离心式冷水机组的最佳补气控制方案。实测结果显示,合理调节补气阀开度能够提高机组能效,采用该补气控制方案后,与补气不做控制(补气阀固定开度100%)方案相比,满载时性能相当,部分负荷下性能提高约2%,综合部分负荷性能系数IPLV提高约2%;并减少机组在开机、运行、关机等阶段补气带液风险,保证机组安全高效稳定运行。

Reasonable intermediate suction control is of great significance to improve the performance and safe operation of two-stage compression centrifugal chiller.The theoretical cycle of the two-stage compression centrifugal chiller with intermediate suction is analyzed,and the experimental study is conducted on the influence of different intermediate suction valve’s opening degrees on the cooling capacity,power consumption and energy efficiency ratio of two-stage compression centrifugal chiller under the given opening degree of guide vane,then the influence of different intermediate suction valve’s opening degrees on the performance and safe operation of the unit is verified,and the best intermediate suction control scheme matching the two-stage compression centrifugal unit is obtained.The test results show that the coefficient of performance of the unit can be improved by reasonably adjusting the opening degree of the vapor injected valve.Compared with the scheme without intermediate suction control(the vapor injected valve with the fixed opening degree of 100%),using this intermediate suction control scheme,the performance under full load is equivalent,and the performance under partial load is improved by about 2%,the integrated part load value(IPLV)is improved by about 2%,and the risk of liquid refrigerant suction during the startup,operation and shutdown stages of the unit is reduced,so as to ensure the safe,efficient and stable operation of the unit.