Estudo experimental de um controle adaptativo para um sistema de refrigeração

Abstract

This research deals with a experimental study of vapor compression refrigeration system, with variable speed compressor using adaptative fuzzy control, comparing it s results with On-Off and PI control. The experimental equipment used is composed of a semi-hermetic compressor, concentric tube evaporator and condenser, thermostatic expansion valve with manual equalization. The equipment was totally instrumented using PT-100 temperature sensors, piezo-resistive pressure transducers, coriolis mass flow rate meter, cooling tower to refrigerant water leaving condenser, electrical resistance, using PID to control water temperature supply to evaporator, analogical signal amplification and conditioning and logic programming controller (PLC) to digitalize and operate PID and variable speed compressor. It was used LABVIEW software for monitoring and operation of experimental equipment. Results are compared using different mass refrigerant inventory in the experimental equipment, as will as different temperatures of water supply to evaporator. Keeping exhaust evaporator water temperature constant, analysis and recommendation are given when the three types of control are used, showing advantages and limitation of each one.