مدل سازی تحلیلی و شبیه سازی عددی انتقال حرارت در یک اواپراتور پوست

This paper presents a one-dimensional, steady-state, analytical and a two-dimensional, steady-state, numerical approach to describe heat transfer in the complex solid structure of a skin evaporator used in household refrigerators. Both models are based on a specific form of the energy equation (the heat diffusion equation), which is solved to obtain the temperature distributions and heat flows within the different parts of the structure. Heat transfer is limited by a number of thermal resistances, such as the inner plastic wall of the refrigerator, the aluminum plate, the foil, the tube of the evaporator, and the air gaps. The insulation that prevents heat flowing into the evaporator from the surroundings is also taken into consideration. A comparison of the models showed that the root-mean-square deviation of the calculated temperatures ranged from 0.34 K to 0.60 K and that the area-weighted discrepancy of the calculated heat flows was 4.6%. Experimental validation of the model showed that the calculated and measured evaporator capacities were within ±12%. This demonstrates that several simplifications to the analytical model can be made, so drastically reducing the complexity of modeling a skin evaporator's structure, while retaining sufficient accuracy. These simplifications include reducing the heat transfer to one-dimensional heat conduction in the individual parts of the structure, neglecting the heat flux through the aluminum–air-gap contact, and linearizing the aluminum foil.