A thin-walled copper tube of outside metal radius r = 0.008 m carries stream at 383 K. It is inside a room where the sourrounding air temperature is 300 K. The tube is insulated with magnesia insulation of an approximate thermal conductivity of 0.071 W/(mK).
A thin-walled copper tube of outside metal radius r = 0.008 m carries stream at 383 K. It is inside a room where the sourrounding air temperature is 300 K. The tube is insulated with magnesia insulation of an approximate thermal conductivity of 0.071 W/(mK).
(a) What is the critical thickness of insulation for an external convective coefficient h = 4.0 W/(m2K).(Assume negligible conduction resistance due to the wall of the copper tube).
(b) Under these conditiions, determine the rate of heat transfer per meter of tube length for (i) a 0.004 m thick layer of insulation (ii) the critical thickness of insulation (iii) a 0.05 m thick layer of insulation.
