Question

Consider steady heat transfer between two large parallel plates at constant temperatures of T1 = 210 K and T2 = 150 K that are L = 2 cm apart. Assume that the surfaces are black (emissivity ε = 1). Determine the rate of heat transfer between the plates per unit surface area assuming the gap between the plates is filled with atmospheric air.

Answer 1

Answer:

$Q=81.56\ W/m^2$

Explanation:

Given that

$T_1= 210 K$

$T_2= 150 K$

Emissivity of surfaces(∈) = 1

We know that heat transfer between two surfaces due to radiation ,when both surfaces are black bodies

$Q=\sigma (T_1^4-T_2^4)\ W/m^2$

So now by putting the values

$Q=\sigma (T_1^4-T_2^4)\ W/m^2$

$Q=5.67\times 10^{-8}(210^4-150^4)\ W/m^2$

$Q=81.56\ W/m^2$

So rate of heat transfer per unit area

$Q=81.56\ W/m^2$