Transient simulation of small-capacity reciprocating compressors in on-off controlled refrigerators

Abstract

This paper presents a simulation model for the transient behavior of vapor compression refrigerating appliances subjected to on-off control patterns focusing on the reciprocating compressor. A detailed compressor model is adopted, which can predict the valve dynamics, pressure pulsations in mufflers, and temperature of different components. The remaining components of the single-door frost-free refrigerator considered in this work are modeled based on mass and energy balances considering each component as an even lump. The overall system simulation model was validated by comparing predictions for the compressor temperatures and mass flow rate, indicated power, power consumption and overall energy consumption with the experimental counterparts measured in a household refrigerator, whose components – including the compressor – were carefully instrumented with thermocouples and pressure transducers, and tested in a climate chamber. Finally, sensitivity analyses were conducted to assess the effect of the compressor design parameters on its performance under calorimeter and actual system conditions.