EXPERIMENTAL AND THEORETICAL STUDY OF MINIATURE VAPOR COMPRESSION CYCLE USING MICROCHANNEL CONDENSER

Abstract

Experimental study for miniature vapor compression cycle working at R-134a with 550 W cooling capacity, using microchannel condenser was presented. Microchannel condenser that used in this work made from aluminum, have 12 rectangular channel with hydraulic diameter 1.07 mm, and dimensions (25×11.8×2 cm) with 146 micro fins per tube. This unit consist of tiny compressor, microchannel condenser, and capillary tube and finned tube evaporator. System with microchannel condenser was analyzed. The variation of refrigerant-side heat transfer coefficient of condenser and compressor work were studied under the following key variables; ambient temperature increased from 30 to 40 oC. Load applied to evaporator increased from 100 to 300 W and evaporator fan velocity different from 4 to 5.5 m/s. Results showed that, increasing in ambient temperature lead to 31% reduction in heat transfer coefficient, and 19% increasing in compressor work. While increasing in evaporator load cause 4% decreasing in heat transfer coefficient, finally compressor work increased by 8.9%. This result have a good agreement with numerical data. The standard deviation was 8.4% for heat transfer, 6.9% for heat rejection.