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(7.16) A refrigerated truck is used to transport food. The roof of the container is of composite construction, consistin
Posted: Thu Jul 14, 2022 2:51 pm
by answerhappygod
- 7 16 A Refrigerated Truck Is Used To Transport Food The Roof Of The Container Is Of Composite Construction Consistin 1 (122.49 KiB) Viewed 30 times
(7.16) A refrigerated truck is used to transport food. The roof of the container is of composite construction, consisting of a layer of foamed urethane insulation (d2=50 mm,k2=0.026 W/mK) sandwiched between aluminum alloy panels (d1=5 mm,k1=180 W/mK ). This construction keeps the internal surface temperature of the roof constant and equal to Ts,i=−10∘C. The superficial area of the roof is 35 m2( L=10 m, W=3.5 m). In a normal day, the truck moves at a speed of 105 km/h, the air temperature is Tin=32∘C, and there is solar irradiation incident on the roof with a magnitude of Gs=800 W/m2. Assume turbulent flow over the entire length of the roof and consider the solar absorptivity and emissivity of the outer surface equal to ε=α=0.5. Calculate the average external roof temperature (Ts,o), and corresponding heat load imposed on the refrigeration system. If the roof is not insulated (d2=0), calculate the corresponding values of the surface temperature and the heat load.