Given that the equation for the rate of heat transfer (ϕ
) through a solid by conduction is
ϕ=kA∇T
measured in Js-1
or W
where
k is the thermal conductivity of the material (WK-1m-1
)
A is the surface area (m2
)
∇T
is the temperature gradient (Km-1
)
Calculate the heat that will pass through a wall that measures 3
m by 5
m and has a thickness of 0.5
m given that the wall is made from refractory material whose thermal conductivity is 1.3Wm-1K-1
. The inside temperature of the wall is 700K(427∘C)
and the outside surface is at 323K(50∘C)
.
Give your answer to the nearest kW