Radiation (30%)
The cylindrical peephole (thermally insulated) in a furnace wall of thickness L=250mm has a
diameter of D=125mm. the furnace interior surface has a temperature of 1000K, in comparison
to 300K for the surrounding temperature.
(a) The open-ends of the cylindrical peep-hole and {:A_(2)) and the cylindrical lateral surface
of the refractory material (A_(R)) form a diffuse-gray, three-surface enclosure. What are the
emissivity and the effective temperature of the hypothetical areas A_(1) and A_(2) ? (5%)
(b) Draw the radiative thermal circuit for the three surfaces. Mark the expression of each
thermal resistance. (5%) c) find the heat loss through the peephole.you may use table 13.2 in the appendix. d) also find the temperature of thee peephole surface Ar
2.Radiation(30%) diameter of D=125 mm. the furnace interior surface has a temperature of 1000 K, in comparison to 300 K for the surrounding temperature. Refractory material Furnace interior Surroundings, T=1000K T=300K
D=125mm L=250mm
(a) The open-ends of the cylindrical peep-hole (A, and A,) and the cylindrical lateral surface of the refractory material (A_) form a diffuse-gray, three-surface enclosure. What are the emissivity and the effective temperature of the hypothetical areas A and A? (5%)
(b) Draw the radiative thermal circuit for the three surfaces. Mark the expression of each thermal resistance.(5%