Question 1 A furnace wall consisting of 0.20 m of fire clay brick. 0.15 m of kaolin, and a 0.05-m outer layer of masonry brick is exposed to furnace gas at 1250 K with air at 298 K adjacent to the outside wall. The inside and outside convective heat transfer coefficients are 55 and 10 W/m² K, respectively. 1.1. Determine the heat loss per square meter of wall and the temperature of the outside wall surface under these conditions. 1.2. Assuming that the outside of temperature of the masonry brick in question 1.1 may not exceed 350K; find the adjusted thickness of kaolin to maintain the same heat flux requirements.

Question 1 A furnace wall consisting of 0.20 m of fire clay brick. 0.15 m of kaolin, and a 0.05-m outer layer of masonry brick is exposed to furnace gas at 1250 K with air at 298 K adjacent to the outside wall. The inside and outside convective heat transfer coefficients are 55 and 10 W/m² K, respectively. 1.1. Determine the heat loss per square meter of wall and the temperature of the outside wall surface under these conditions. 1.2. Assuming that the outside of temperature of the masonry brick in question 1.1 may not exceed 350K; find the adjusted thickness of kaolin to maintain the same heat flux requirements.

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 1.39P: 1.39 On a cold winter day, the outside wall of a home is exposed to an air temperature of when the...

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1.39 On a cold winter day, the outside wall of a home is exposed to an air temperature of when the inside temperature of the room is at . As a result of this temperature gradient, there is heat loss through the wall to the outside. Consider the convective heat transfer coefficients for the air inside the room and at the outside wall surface to be, respectively, 12.0 and . If the composite room wall is modeled as a plane wall with a thermal resistance per unit area of , determine the temperature at the outer surface of the wall as well as the rate of heat flow through the wall per unit area. If the homeowner were to consider using a fiberglass insulation layer on the inside wall surface for reducing this heat loss by 50%, what is the required thickness of this layer and the outside wall temperature for this case?