梯级吸排气循环理论及应用  

Fundamentals and Applications of Stepped Pressure Cycle

作　　者：曹祥[1,2] 张春路 Cao Xiang;Zhang Chunlu(Postdoctoral Station of Mechanical Engineering,Tongji University,Shanghai,201804,China;Institute of Refrigeration and Cryogenics,School of Mechanical Engineering,Tongji University,Shanghai,201804,China)

机构地区：[1]同济大学机械工程博士后流动站,上海201804 [2]同济大学机械与能源工程学院制冷与低温工程研究所,上海201804

出　　处：《制冷学报》2021年第3期28-33,共6页Journal of Refrigeration

基　　金：国家自然科学基金(51676140)资助项目。

摘　　要：为了提升蒸气压缩式制冷/热泵装置的能效,提出了一种新循环——梯级吸排气循环。通过设置数个具有一定梯度的吸排气压力,实现制冷剂对换热流体温度的梯形逼近,有效减小蒸发器与冷凝器的传热不可逆损失,同时降低循环压比。梯级吸排气循环的实际节能效果受多种因素影响,研究表明:换热流体温度变化幅度以及蒸发器与冷凝器传热能力强弱对其节能幅度的影响超过6.5%;不合理的过冷度设计甚至会导致其丧失节能性。最后,本文基于实践案例对梯级吸排气循环在实际应用中的节能效果进行介绍。A stepped pressure cycle is proposed to improve the energy efficiency of refrigeration and heat pump cycles.By constructing multiple suction and discharge pressures,the refrigerant temperatures in the evaporators and condensers underwent step changes and approached the heat source temperatures.This helps to improve heat transfer efficiency and reduce the compression ratio.However,we found that the conclusion of energy savings for the stepped pressure cycle is conditional.Over 6.5%of the energy-saving potential is reduced because of inefficient heat exchangers or a small temperature glide of the heat transfer fluid.Moreover,an excessive subcooling degree will lead to a worse COP than a simple cycle.Finally,in this study,some application cases are summarized to demonstrate the energy-saving potential of the stepped pressure cycle.

关 键 词：制冷 热泵 节能 梯级吸排气循环 

分 类 号：TB611[一般工业技术—制冷工程] TB657.5