3- A steel (k = 15 W/mK) tube with 5 cm inner diameter and 7.6 cm outer diameter is covered with an insulation (k = 0.2 W/m K) of thickness 0.2 cm. A hot gas at 330°C flows through the tube with hi = 400 W/m2 K. The outer surface of the insulation is exposed to air at 30°C with ho = 60 W/m2 K. Calculate: %3D (a) the heat loss from the tube which is 10 m long. (b) the temperature drops resulting from the thermal resistances of the hot gas flow, the steel tube, the insulation layer and the outside air. Ans. (a) 7251 W, (b) 12°C, 3.3°C, 253°C and 31.7°C)

3- A steel (k = 15 W/mK) tube with 5 cm inner diameter and 7.6 cm outer diameter is covered with an insulation (k = 0.2 W/m K) of thickness 0.2 cm. A hot gas at 330°C flows through the tube with hi = 400 W/m2 K. The outer surface of the insulation is exposed to air at 30°C with ho = 60 W/m2 K. Calculate: %3D (a) the heat loss from the tube which is 10 m long. (b) the temperature drops resulting from the thermal resistances of the hot gas flow, the steel tube, the insulation layer and the outside air. Ans. (a) 7251 W, (b) 12°C, 3.3°C, 253°C and 31.7°C)

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter6: Forced Convection Over Exterior Surfaces

Section: Chapter Questions

Problem 6.36P

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