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4. In a chemical plant, some of the chemicals are stored in a rectangular metal shed where the shed walls are made of 0.43 cm thick aluminum, with a 0.95

cm thick layer of insulation (k = 0.079 W/m-K). At steady state, the aluminum surface of the wall is exposed to an incident solar radiation heat flux of 2150 W/m², which heats the aluminum. Aluminum has an absorptivity value of 0.78, which means that 73% of the incident radiation is transferred to the aluminum, while the rest is reflected away. The aluminum is also exposed to wind, which removes some of this heat by convection. The outside air temperature is 35 °C, and the surface of the aluminum is 54 °C. The convective heat transfer coefficient for the wind is 76 W/m2-K. A. Use an energy (or heat) balance to determine the heat transfer rate through the aluminum and insulation layers for the wall exposed to the sun (which has dimensions of 2.3 m tall by 5.9 m wide). Assume steady state, 1-dimensional heat transfer with constant k (you can look up at 300 K). B. For the wall in (A), what is the temperature on the surface of the insulation inside the shed?

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