Question

A rectangular furnace wall is made of fire clay (Height = 3m, Width = 1.2m, thickness L=0.17m) The temperautre of the inside surface ( area H x W, Tx, is 1592 K,and of the outside surface (area = H x W ), Tc is 1364 K

Determine the temperature gradient

Determine the heat transfer rate

Determine the heat transfer flux

Determine thermal resistance

Answer #1

temperautre of the inside surface Th = 1592 K

temperautre of the outside surface Tc = 1364 K

Thickness L = 0.17 m

Part a

Temperature gradient

dT/dx = (Tc - Th) / L

= (1364 - 1592) K / 0.17 m

= - 1164.71 K/m

Part b

Heat transfer rate q = - kAdT/dx

= - 1.7 W/m-K x (3 x 1.2 m2) x (- 1164.71 K/m)

= 7128.02 W

Part c

Heat transfer flux

Q = q/A = 7128.02 W / (3 x 1.2 m2)

= 1980 W/m2

Part d

Thermal resistance = L/kA

= (0.17 m) / (1.7 W/m-K x 3 x 1.2 m2)

= 0.0277 K/W

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