Question

A rectangular kiln is exposed to ambient air at 29.6 °C, which has a convection coefficient of 5.0 W/m^2°C around the kiln. For safety reasons the outside surface temperature must be limited to 35 °C. Under steady operation the temperature of internal surface of the kiln is 444 °C. Find out the total thermal resistance (in °C/W) needed to achieve the safe conditions.

Answer 1

Step-by-step explanation:

Given data:

`T∞ =29.6 degree\ celcius`

`H∞  = 5 w/m^2 -degree C`

`T_s = 35 degree \celcius`

`T_i = 444 degree \celcius`

Total stiffness resistance can be calculated as

`\theta = (Ts -T\infty)/((1)/(H\infty A)) =(T_i - T\infty )/((R)/(A))`

`(35- 29.6) 5 = (444- 29.6)/(R)`

`27* R = 414.4`

Solving for R we get

R = 15.348 Degree C/W