ANALYSIS OF REFRIGERATING CYCLES WORKING WITH ISOBUTANE UNDER TRANSIENT CONDITIONS

摘要

The aim of this document is to present a numerical model to simulate vapor compression refrigerating systems at transient conditions. The work is focused on studying systems working with variable speed compressors. Basically, the numerical procedure consists in solving independently each of the system elements (compressor, expansion device, evaporator, condenser, and auxiliary elements) under an object oriented program, and to iteratively transfer information between them in order to attain the global solution. The model has been validated against experimental data acquired from an experimental facility specially designed to test vapor compression refrigerating cycles. The set up included a household refrigerator commercial compressor, two double-pipe counter-flow heat exchangers (evaporator and condenser) and a commercial capillary tube as the expansion device. The data have been obtained at different working frequencies and using the natural refrigerant R600a. The numerical results show good agreement with the experimental measurements.