A two-layer 24 m² plane wall consists of a 250 mm thick inner concrete layer with thermal conductivity k, of 2 W/m K and a 80 mm thick outer insulation with k of 0.04 W/m K. The temperatures of wall inner and outer surfaces are t, = 28°C and tą = -9°C. Calculate (i) the rate of heat transfer and (ii) the temperature t, of the wall intermediate surface.

i need the answer quickly

A furnace wall is made up of three layer of thickness 150 mm, 110 mm, and 125mm with thermal conductivity of 1.65 W/m-K, k2, and 9.2 W/m-K respectively. Theinside is exposed to gases at 1050°C with a convection coefficient of 25 W/m2-Kand the inside surface temperature is at 900°C, the outside air temperature is at30°C with convection coefficient of 12 W/m2 -K. Calculate:a. the unknown thermal conductivity;b. the outside surface temperature and mid-plane temperatures in °F.

i need the answer quickly

The lining of box-type fumace is made up of a refractory layer and steel plate as shown in the figure. Steady state temperature at the surface of the refractory is 1273 K and that at the outer steel surface is 473 K. If the steady state heat flux through the refractory-steel plate composite is 1600 W/m², and heat flow is along x-direction only, the thermal contact resistance (m² K/W) between refractory and steel is_ steel Refractory 1273K Furnace 473K Ambient Given data: Thermal conductivity of refractory = 1.2 W/m-K Thickness of refractory lining = 80mm Thermal conductivity of steel = 32 W/mK Thickness of steel plate = 4mm