the amount of excess combustion air is normally determined by analysis of stack_____ a) the fuel bill  b) O2 c) N2 d) O3

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Heat Conduction The wall (thickness L) of a furnace, with inside temperature 800° C, is comprised of brick material [thermal conductivity = 0.02 W m-¹ K-¹)]. Given that the wall thickness is 12 cm, the atmospheric temperature is 0° C, the density and heat capacity of the brick material are 1.9 gm cm-³ and 6.0 J kg ¹ K¹ respectively, estimate the temperature profile within the brick wall after 2 hours. Solve the partial differential equation ƏT = pc at Ə əx (NOT) k subject to the initial condition TX 2L and = T(x,0) = 800 sin and boundary conditions at the inner (x = L) and outer (x = 0) walls of T = 0 x = 0 = 0 ƏT at x = L əx Find the temperature profile at T = 7200 seconds at = 2 hours.

Insulating material is used to reduce heat loss from the heating furnace walls to the room. The surface temperature of the insulating material is 100 ° C and the other surfaces 25 ° C. Allowable heat loss up to 160 W / m2 from the wall. If the thermal conductivity of the insulation material is 0.05 W / (m ° C), calculate the required thickness of insulation. insulation thickness = Answer cm