Calculate the heat transfer rate for the following composite wall configurations: (A)Consider a composite plane wall that includes a 10 mm-thick hardwood siding, 50-mm by 120- mm hardwood studs on 0.7m centres with glass fiber insulation (paper faced, 28 kg/m3 ), and a 15 mm layer of gypsum wall board. What is the thermal resistance per unit area associated with this wall (having 10 studs, each 2.5 m high). In addition, given the temperature at the inlet and outlet surface is 20 ºC and -15 ºC, calculate the heat transfer rate though this wall.
Calculate the heat transfer rate for the following composite wall configurations:
(A)Consider a composite plane wall that includes a 10 mm-thick hardwood siding, 50-mm by 120-
mm hardwood studs on 0.7m centres with glass fiber insulation (paper faced, 28 kg/m3
), and a 15
mm layer of gypsum wall board. What is the thermal resistance per unit area associated with this
wall (having 10 studs, each 2.5 m high). In addition, given the temperature at the inlet and outlet
surface is 20 ºC and -15 ºC, calculate the heat transfer rate though this wall.
(B) Stainless steel tube is used to transport pharmaceutical liquids, it has an inner diameter of 40 mm
and a wall thickness of 4 mm. The pharmaceutical and ambient air are at temperatures of 6 C and
23C, respectively, while the corresponding inner and outer convection coefficients are 400 W/m2
.K and 6 W/m2 K, respectively.
(a) What is the heat gain per unit length?
(b) What is the heat gain per unit length if a 10 mm thickness layer of calcium silicate insulation
(kins = 0.050 W/m. K) is applied to the tube?
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