Thermal Conductivity Problems: a. A wall is made of firebrick 6 inches thick and has a 50°C difference in temperature both sides. Calculate the heat transferred through the wall if the thermal conductivity of the brick is 0.65 BTU/hr-ft- oF. b. Compute the amount of heat flow per second through an iron plate 2 cm thick and the area of 5000 cm² if one face has a temperature of 150°C and the other face is 140°C? The thermal conductivity for iron is 80 W/m-K.

Thermal Conductivity Problems: a. A wall is made of firebrick 6 inches thick and has a 50°C difference in temperature both sides. Calculate the heat transferred through the wall if the thermal conductivity of the brick is 0.65 BTU/hr-ft- oF. b. Compute the amount of heat flow per second through an iron plate 2 cm thick and the area of 5000 cm² if one face has a temperature of 150°C and the other face is 140°C? The thermal conductivity for iron is 80 W/m-K.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.34P: A section of a composite wall with the dimensions shown below has uniform temperatures of 200C and...

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One end of a 0.3-m-long steel rod is connected to a wall at 204C. The other end is connected to a wall that is maintained at 93C. Air is blown across the rod so that a heat transfer coefficient of 17W/m2 K is maintained over the entire surface. If the diameter of the rod is 5 cm and the temperature of the air is 38C, what is the net rate of heat loss to the air?
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1.63 Liquid oxygen (LOX) for the space shuttle is stored at 90 K prior to launch in a spherical container 4 m in diameter. To reduce the loss of oxygen, the sphere is insulated with superinsulation developed at the U.S. National Institute of Standards and Technology's Cryogenic Division; the superinsulation has an effective thermal conductivity of 0.00012 W/m K. If the outside temperature is on the average and the LOX has a heat of vaporization of 213 J/g, calculate the thickness of insulation required to keep the LOX evaporation rate below 200 g/h.
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