Answer to Question #65093 in Molecular Physics | Thermodynamics for Amit Kumar

Question

A steel pipe of 50 mm bore and wall thickness 10 mm is lagged by insulation 30 mm thick. The pipe carries water at a temperature of 65 deg C. and the atmospheric temperature is 20 deg C. Calculate each of the following:
i) The heat transfer rate per unit length of pipe;
ii) The inside surface temperature of the steel;
iii) The temperature at the interface between steel and insulation;
iv) The outside surface temperature of the lagging.

Note: thermal conductivity of steel = 52 W/mK
Thermal conductivity of insulation = 0.17 W/mK
Inside surface heat transfer coefficient = 1136 W/m2K
Outside surface heat transfer coefficient = 9.7 W/m2K