CONDENSATION HEAT TRANSFER AND PRESSURE DROP OF REFRIGERANT R-134A IN A PLATE HEAT EXCHANGER

摘要

An experimental refrigerant loop has been established in the present study to measure the condensation heat transfer coefficient h_r and frictional pressure drop △P_f of R-134a in a vertical plate heat exchanger. Two vertical counter flow channels were formed in the exchanger by three plates of commercialized geometry with a corrugated sinusoidal shape of a chevron angle of 60 deg. Downflow of the condensing R-134a in one channel releases heat to the cold upflow of water in the other channel. The effects of the refrigerant mass flux, average imposed heat flux, system pressure(saturated temperature) and vapor quality of R-134a on the measured data were explored in detail. The results indicate that at a higher vapor quality the condensation heat transfer coefficient and pressure drop are significantly higher.