Answered You can hire a professional tutor to get the answer.

QUESTION

1)Consider a large plane wall of thickness L = 0.4 m, thermal conductivity k = 1.8 W/mK, and surface area A = 30 m2 .

1)Consider a large plane wall of thickness L = 0.4 m, thermal conductivity k = 1.8 W/m·K, and surface area A = 30 m2 . The left side of the wall is maintained at a constant temperature of T1 = 90°C while the right side wall is maintained at a constant temperature at T2 =25°C. Assuming constant thermal conductivity and no heat generation in the wall.

(a) Express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall

(b) Obtain a relation for the variation of temperature in the wall by solving the differential equation (c) Evaluate the rate of heat transfer through the wall 

2)The wall of a refrigerator is constructed of fiberglass insulation (k = 0.035 W/m·K) sandwiched between two layers of 1-mm-thick sheet metal (k = 15.1 W/m·K). The

refrigerated space is maintained at 3°C, and the average heat transfer coefficients at the inner and outer surfaces of the wall are 4 W/m2·K and 9 W/m2·K, respectively. The kitchen temperature averages 25°C. It is observed that condensation occurs on the outer surfaces of the refrigerator when the temperature of the outer surface drops to 20°C. Determine the minimum thickness of fiberglass insulation that needs to be used in the wall in order to avoid condensation on the outer surfaces. 

Show more
LEARN MORE EFFECTIVELY AND GET BETTER GRADES!
Ask a Question