Evaluation of Methods to Decrease the Discharge Temperature of R32 Scroll Compressor

摘要

Recently, R32 has been considered as an important alternative in application of small to middle capacity airrnconditioner by many countries due to its advantages such as low global warming potential (GWP), favorable thermalrnproperties, less refrigerant charge and low cost. However, the much increased discharge temperature of R32rncompressor, as compared with the R22, becomes the main barrier affecting the wide and quick adoption. Refrigerantrninjection has proven to be effective in decreasing discharge temperature. In this work, three kinds of refrigerantrninjection technology used to decrease the discharge temperature of R32 scroll compressor are discussed, namely,rntwo-phase suction, liquid injection and two-phase/gas injection. The detailed scroll compressor model proposed inrnprevious work is modified and validated by experimental data of R32 scroll compressor. The potentials inrndecreasing discharge temperature of the three methods are investigated. The detailed performance comparisons arernpresented. The results indicate that the two-phase/gas injection achieves the best performance with the enhancementrnof cooling capacity by 14.2% and increase in COP by 8.1%.