A composite 3-layered wall is formed of a 0.5 cm thick aluminium plate of thermal conductivity 249 W/mK, a 0.25 cm thick layer of sheet asbestos also with a thermal conductivity of 0.166 W/mK and a 2.0 cm thick layer of a rock wool with thermal conductivity 0.0548 W/mK. The asbestos is the center layer. The outer aluminium surface is at 400 oC and the outer rock wool surface is at 50 oC. Determine the heat flow per unit area?

A composite 3-layered wall is formed of a 0.5 cm thick aluminium plate of thermal conductivity 249 W/mK, a 0.25 cm thick layer of sheet asbestos also with a thermal conductivity of 0.166 W/mK and a 2.0 cm thick layer of a rock wool with thermal conductivity 0.0548 W/mK. The asbestos is the center layer. The outer aluminium surface is at 400 oC and the outer rock wool surface is at 50 oC. Determine the heat flow per unit area?

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.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.1P: 1.1 On a cold winter day, the outer surface of a 0.2-m-thick concrete wall of a warehouse is exposed...

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1.10 A heat flux meter at the outer (cold) wall of a concrete building indicates that the heat loss through a wall of 10-cm thickness is . If a thermocouple at the inner surface of the wall indicates a temperature of 22°C while another at the outer surface shows 6°C, calculate the thermal conductivity of the concrete and compare your result with the value in Appendix 2, Table 11.
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