EXPERIMENTAL STUDY OF THE COMBINED EFFECT OF THE REFRIGERANT CHARGE, COMPRESSOR SPEED AND EXPANSION VALVE OPENING IN A REFRIGERATION SYSTEM

摘要

An experimental study has been performed to evaluate the effect of refrigerant charge, electronic expansion valve (EEV) opening and compressor speed on the thermodynamic performance of a vapor compression refrigeration system. A testing apparatus comprised of a variable speed compressor (VSC), a pulse width modulated (PWM) electronic expansion valve and a device for varying the refrigerant charge, was designed and constructed. It has been found that for a given refrigerant charge the coefficient of performance (COP) at a particular compressor speed can be maximized by a proper opening of the expansion valve. It has also been shown that the optimum evaporator superheat is within a range of 1°C to 3°C.