Question

A refrigerator door has a height and width of H = 1.10 m and W = 0.65 m respectively, and is situated in a large room for which the air and walls are at T Tsur 27°C The door consists of a layer of polystyrene insulation (k = 0.03 w/m-K) sandwiched between thin sheets of steel (ε = 0.6) and polypropylene. Under normal operating conditions, the inner surface of the door is maintained at a fixed temperature of T°C. Obtain the Nusselt numbers using the Churchill and Chu correlation for the vertical plate Air, T Refrigerator compartment Polypropylene surface, T, s.i Steel surface, 5,0 Insulation T.

Estimate the heat gain through the door for the worst case condition corresponding to no insulation (L= 0), in W.

Answer 1