Abstract: A pressure regulation and control system for auto-cascade refrigeration system was designed in order to solve the problem of too high exhaust pressure and exhaust temperature at the starting up process.It is on the basis of three-stage auto-cascade refrigeration system as the research object and including a buffer,an expansion tank,pressure control valve and pipeline.Buffer has the role of easing the impact of high pressure refrigerant gas and stabling the pressure of refrigerant gas.Expansion tank has the effect of receiving and storing refrigerant gas.The bypass branch from buffer may realize high and low pressure bypass through electromagnetic valve and expansion tank.The bypass branch from the upper of the two-phase separator can effectively control and regulation the compressor discharge pressure and exhaust temperature through manual ball valve and flow meter.Through the experimental research,the cabinet with bypass refrigerator system could accelerate initial cooling speed and had the effect of fast cooling refrigerant gas.The system bypass quantity could be adjusted through pressure control valve,and then the system pressure and temperature could be controlled in a reasonable range.It might avoid forced shutdown of pressure control system.

Key words: auto-cascade refrigeration, pressure characteristics, bypass control, refrigeration system

摘要： 针对自复叠制冷系统开机初期排气压力和排气温度过高的问题,以三级自动复叠制冷装置为研究对象,设计了一种压力调节和控制系统,主要包括缓冲器、膨胀容器、压力控制阀和管路等。缓冲器具有缓和高压气体对设备的冲击和降压稳压作用;膨胀容器具有收纳和贮存制冷工质的作用。缓冲器中引出一个旁通支路,通过电磁阀和膨胀容器后实现高低压旁通;两个相分离器上部各引出一个气体支路,通过手动球阀和流量计并联旁通到膨胀容器,对压缩机的排气压力和排气温度进行有效控制和调节。通过实验研究,具有旁通的冷柜系统启动初期降温速度加快,能够快速冷却制冷工质。通过压力控制阀对系统的旁通量进行调节,从而控制系统的压力和温度在合理的范围内,避免压力控制装置强制停机。

关键词: 自动复叠制冷, 压力特性, 旁通调节控制, 制冷系统