Experimental study on R-134a evaporation heat transfer characteristics in plate and shell heat exchanger

An experiment was carried out to investigate the characteristics of the evaporation heat transfer for refrigerant R-134a flowing in a plate and shell heat exchanger. The data are useful in designing more compact and effective evaporators for various refrigeration and air conditioning systems. Two vertical counterflow channels were formed in the exchanger. The R-134a flows up in one channel exchanging heat with the hot water flowing down in the other channel. The effects of the average heat flux, mass flux, saturation temperature and vapor quality were examined in detail. The present data show that the evaporation heat transfer coefficient increases with the vapor quality. A rise in the refrigerant mass flux causes an increase in the hr value. A rise in the average imposed heat flux causes an increase in the hr value at the low quality. Finally, at a higher refrigerant saturation temperature the hr value is found to be lower