Q1. Consider the composite materials shown in figure. 1. Sketch the equivalent thermal resistance. 2. Calculate the heat transfer per unit area of the wall. 3. Determine the temperatures at interface between the layers. Material k (W/m K) A 2.1 B 6.7 C 3.5 T=15 °C A C B C 3320-02 + 20 30 1/4 14h-10 W/m² K +T=50 °C mm (

Q1. Consider the composite materials shown in figure. 1. Sketch the equivalent thermal resistance. 2. Calculate the heat transfer per unit area of the wall. 3. Determine the temperatures at interface between the layers. Material k (W/m K) A 2.1 B 6.7 C 3.5 T=15 °C A C B C 3320-02 + 20 30 1/4 14h-10 W/m² K +T=50 °C mm (

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.

Chapter2: Steady Heat Conduction

Section: Chapter Questions

Problem 2.47P

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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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2. In determining the thermal conductivity of a plateflat insulator, the temperature was measured on both sides of the 25 mm thick plate and gave the results of 318.4 K and 303.2 K. FluxThe measured heat is 35.1 W.m-2. Illustrate the problem in a simple schematic/drawing, then calculate the thermal conductivity inbtu/h.ft.oF and in W/m.K! (0.033 ; 0.058) 3. A coil-shaped cooling pipe is made of SS-304 material. This pipe is 1 ft long, 0.4 inch outside diameter, and inch inside diameter. This coil cooling pipe is used to cool the water in the bath. The temperature of the inner coil pipe is 40oF while the outer coil in contact with water is 80oF. The thermal conductivity of SS-304 is a function of temperature where k(T) = 7.75 + (7.78 x 10-3).T where k is in Btu/h.ft.oF and T is in oF. Calculate the rate of heat dissipation in watts! (1287.7)
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(3-5) A composite furnace wall has an inside wall temperature of 1100 C and an outside wall temperature of 38 C. The types of bricks are available as follows: brick k, W/m-k Thickness, cm Max allowable temp, °C 1. 1.45 10.5 2 0.18 5.5 875 3 0.50 7.0 200 The heat loss must not exceed 0.73 kw/ m?. 3. Determine the minimum wall thickness 4. The actual heat loss for (6) 5. The temperature between the last two bricks counting from the inside.
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