the walls of an oven are made from steel sheets with insulating board betwwen them of thermal conductivity 0.18jm-1s-1℃-1.if the maximum internal temperature in the ovem is 300℃and the outside surface of the oven wall must not rise above 50℃, estimate the minimum necessary thickness of insulation assuming surface heat transfer coefficients to the air on both sides of the wall are 15jm-2s-1℃0-1. assume the room air temperature outside the oven to be 25℃ and that the insulating effect of the steel sheets can be neglected.
q = ?
A = ?
k = 0.18jm-1s-1℃-1
온도차 = (300-50)
온도차 = (300-25)
q=a(단면적)t(온도차)k(열전도도)/x(두께) 이식으로 구하려고 해봤는데
q=a?*(300-50)*0.18jm-1s-1℃-1*x?
q=a?*(300-25)*0.18jm-1s-1℃-1*x?
단면적,q?도 안 나와있는데 제가 어느 부분이 잘못된건가요?
