Study Of Heat Transfer Performance And Air Flow Resistance Characteristic Of Automobile Air Conditioner Evaporator Plating With Hydrophilic Film

To improve the heat transfer performance of the evaporator is a main method contributed to energy-saving of automobile air conditioner. Plating the fin with hydrophilic coating is one of the methods to enhance the heat transfer performance of the evaporator.The automobile air conditioner plating with hydrophilic coating, with it's hydrophilicity on the fin surface, can make water condensate formed under wet condition "film-wise" and flow rapidly, so it can avoid the decreasing of air volume and cooling capacity caused by the "water bridge" phenomenon under wet condition. On the other side, the surface treatment with hydrophilic coating can decrease air resistance, energy consumption of the fan and noise.The distribution and magnitude of the "water bridge" under wet condition were measured, and a new concept of effective heat transfer area coefficient was proposed. The mechanism of hydrophilic coating how to influence the heat transfer performance and air resistance characteristic were analyzed from the aspects of effective heat transfer area, heat transfer coefficient and temperature difference of heat transfer.The steady-state mathematical model of evaporator was established in this paper. The simulation calculations and experimental tests of evaporator were carried out on evaporators with & without hydrophilic coating under dry & wet conditions. The results proved that the hydrophilic treatment obviously improved the heat transfer performance and air resistance characteristic, and contributed to improving the cooling capacity by 5% and decreasing the airflow resistance by 30%～52%.