CONTROL OF VAPOUR COMPRESSION CYCLE REFRIGERATION SYSTEMS

摘要

A vapour compression cycle refrigeration system of the type having the expansion valve (11) controlled by a temperature sensing bulb (12) at the downstream end of the evaporator (5). A by-pass line (15) is provided from the expansion valve outlet to the evaporator (5) to inject wet vapour upstream from the temperature sensing bulb (12) and provide proportioned negative feedback to the expansion valve (11) to reduce hunting or oscillating of the system.
Variations of the by-pass line are also described to give positive feedback and combinations giving integral and derivative action.