Investigation of Optimum Refrigerant Charge and Fans' Speed for a Vehicle Air Conditioning System

Abstract

In this study, the performance evaluation and optimization of a recently developed battery-powered vehicle air conditioning (BPVAC) system is investigated. A mathematical model is developed to simulate the thermodynamic and heat transfer characteristics of the BPVAC system and calculate the coefficient of performance (COP). Utilizing environmental chambers and a number of measuring equipment, an experimental setup is built to validate the model accuracy and to conduct performance optimization by changing the charge of refrigerant in the system. The model is validated and employed for performance simulation and optimization in a wide range of speed for the evaporator and condenser fans. The modeling results verify that for any operating condition an optimum performance can be achieved by adjusting the speed of condenser and evaporator fans. The optimum refrigerant charge is obtained, and a potential improvement of 10.5% is calculated for the performance of system under ANSI/AHRI 210/240-2008 specifications.