摘要
为了解决有些地区环境温度过低导致冷凝压力过低使得膨胀阀压降不足影响蒸发器供液量,在传统直膨式制冷系统(TDX)的储液器与膨胀阀之间的液体管路上加装工质泵,变为泵与压缩机双动力直膨式制冷系统(DXPC)。对两种系统进行[火用]分析,并搭建了TDX与DXPC制冷系统对比实验实验台,研究发现,实际DXPC制冷循环与TDX循环相比,冷量[火用]增加了2.76 kJ/kg,供给[火用]下降了27.65 kJ/kg,循环[火用]效率增加了12.6%;TDX系统冷凝器[火用]损失最多,DXPC系统压缩机[火用]损失最多,相比于TDX系统,冷凝器[火用]损失由36.12 kJ/kg降低到12.61 kJ/kg,降低了65.1%,膨胀阀[火用]损失由9.02 kJ/kg降低到4.05 kJ/kg,降低了55.1%;理论分析对蒸发器、冷凝器、膨胀阀的误差较小,合适的选择泵与压缩机的等熵指数有助于提高理论分析的准确性。
The condensing pressure will be extremely low if the ambient temperature is too low.As a result,the pressure drop of the expansion valve will be insufficient which can affect the liquid supply of the evaporator in Traditional Direct Expansion Refrigeration System(TDX).A Dual Power Direct Expansion Refrigeration System of Pump and Compressor(DXPC)is built by installing the working fluid pump on the liquid pipeline between the reservoir and expansion valve.The exergy of two systems were analyzed and the experimental benches of TDX and DXPC refrigeration systems were built.The study found that cooling capacity exergy of the actual DXPC refrigeration cycle increased by 2.76 kJ/kg compared with the TDX cycle,and the supply exergy decreased by 27.65 kJ/kg,the cycle exergy efficiency increased by 12.6%.In the TDX system condenser has the largest exergy exergy loss,and in the DXPC system compressor has the largest loss.Compared with the TDX system,the exergy loss of condenser is reduced from 36.12 kJ/kg to 12.61 kJ/kg,which is reduced by 65.1%,and the expansion valve exergy loss is reduced from 9.02 kJ/kg to 4.05 kJ/kg,which is reduced by 55.1%.Theoretical analysis has less error on evaporator,condenser and expansion valve.Suitable selection of the entropy index of pump and compressor can help to improve the accuracy of theoretical analysis.
作者
周会芳
臧润清
马克臣
Zhou Huifang;Zang Runqing;Ma Kechen(Tianjin Key Laboratory of Refrigeration Technology,Tianjin University of Commerce,Refrigeration Engineering Research Center of Ministry of Education of People’s Republic of China,Tianjin Refrigeration Engineering Technology Center,Tianjin 300134,China)
出处
《低温工程》
CAS
CSCD
北大核心
2020年第1期55-60,66,共7页
Cryogenics
关键词
直膨式制冷系统
泵与压缩机双动力直膨式制冷系统
[火用]损失
direct expansion refrigeration system
dual-power direct expansion refrigeration system for pumps and compressors
exergy loss
