Simulation Model of a Low-Temperature Supermarket Refrigeration System

Abstract

This paper presents a computer simulation model of a low-temperature supermarket refrigeration system whose main components include a compressor, a display cabinet, a condenser, and a thermostatic expansion valve. The energy consumption of the system was evaluated as a function of the store relative humidity, which was measured every 16 seconds for 15 days. The model results were validated with the measurements taken from a representative in-situ supermarket in Auckland, New Zealand. The simulation results indicated that the rate of heat transfer in the evaporator was reduced by nearly 10.5 W for each 1% increase in daily average store relative humidity due to the insulating effect of the frost. The frost thickness was found to grow at 0.0354 mm for each 1% increase in the daily average store relative humidity over a 12 hour operation period between the defrost cycles. The pressure drop of the air over the evaporators increased by around 12 Pa for every 10% rise in the daily average store relative humidity.