Performance Analysis of Frostless Heat Exchanger by Spreading Antifreeze Solution on Heat Exchanger Surface

The effect of antifreeze solution liquid film on the frost prevention is experimentally investigated. It is desirable that the antifreeze solution spreads widely on the heat exchanger surface forming thin liquid film to prevent frost nucleation while having small thermal resistance across the film. A porous layer coating technique is adopted to improve the wettability of the antifreeze solution on heat exchanger surface. The antifreeze solution spreads widely on the heat exchanger surface with 100 mu m thickness by the capillary force resulted from the porous structure. It is observed that the antifreeze solution liquid film prevents a heat exchanger from frosting. The reductions of heat and mass transfer rate caused by the thin liquid film are only 1-2% compared with those for non-liquid film surface.