A food product with 73% moisture content is being frozen in a 7 cm-diameter can. The product density is 970 kg/m³, the thermal conductivity is 1.2 W/(m K), and the initial freezing temperature is -2.5°C. After 11 hour in the -40°C freezing medium, the product temperature is -10°C. Estimate the convective heat-transfer coefficient for the freezing medium. Assume the can has infinite height. a. h = ... W/m² K

In the arctic sea, the ice sheets are melting. Let's calculate the temperautre distribution in one such ice sheet. The sheet is 2 m thick. Under the sheet there is ice-water mixture and it can be assumed that the temperature of the bottom surface of the ice sheet is approximately 0°C. Air at -20°C is blowing above the sheet. The convection coefficient of air is 15 W/m².K. The thermal conductivity of ice is 2.2 W/m.K. What is the temperautre of icesheet at its center (i.e., at 1 m from the surface)?

The 0.5 m x 1.2 m wall of an industrial furnace is constructed from L = 0.15-m-thick fireclay brick having a thermal conductivity of 1.7 W/m-K. The temperature distribution, at an instant in time, is T(x) = a + bxwhere a = 1400 K and b = -950 K/m. Determine the heat fluxes, q, and heat rates, q,, atx = 0 and.x = L, in W/m2 and W respectively. Do steady-state conditions exist? i W/m? i W/m? Ix=0 = i W i W Ix=L = Steady-state conditions exist. ||

The main body of plenum is a steel vessel of diameter 0.1meters has two semicircle domed ends. During operation is will contain mix of fuel and air at approximately 250OC. The wall of the vessel is 0.03meters thick and the plenum is 0.45meters long. Estimate the rate of heat loss from the vessel when the outside air temperature is 45OC. The thermal conductivity of steel is 45 W/m K and the surface heat transfer coefficient on the air side is 8 W/m2 . On the inside it is 65W/m2 . If it was possible to clad the plenum calculate the reduction in the rate of heat loss. Assume the lagging would be 5mm thick and has a thermal conductivity of 0.05 W/m.