一、前言在制冷系统运行过程中,一个重要的课题是随着冷负荷的变化,输入蒸发器的制冷剂流量也必须随之变化.这种随冷负荷变化,制冷剂流量能够自动调节的功能,目前对于非恒定液位的蒸发器,诸如盘管式蒸发器,广泛应用由过热度控制的热力膨胀阀作为自动控制元件。显然,在利用热力膨胀阀作为自控元件的制冷设备中,其调节性能的优劣,直接影响到制冷设备功能的正常发挥, I. INTRODUCTION In the operation of refrigeration system, an important issue is that with the change of cooling load, the flow of refrigerant input into the evaporator must also change accordingly.This function of refrigerant flow can be adjusted automatically with the change of cooling load At present, for non-constant level evaporator, such as a coil evaporator, a superheat-controlled thermostatic expansion valve is widely used as an automatic control element. Obviously, the use of thermal expansion valve as a self-control component of the refrigeration equipment, the advantages and disadvantages of its regulatory performance, a direct impact on the normal functioning of refrigeration equipment,