A nuclear fuel element has the form of a plate 6 mm thick sandwiched between two stainless steel containing sheets. The fuel generates heat at a uniform rate of 0.18 x 106 kW/n3 and has a thermal conductivit of 0.002 kW/mK. The element is cooled by water at 50°C and the heat transfer coefficient on one side is 0.6 kW/m2K and on the other is 1.0 kW/m2K. The contact resistance between the fuel and the stainless steel is equivalent to a transfer coefficient of 20 kW/m2K. Assuming the resistance of the stainless steel to be negligible, determine the position and magnitude of the maximum temperature and the heat flux on each side of the element.

A 45.6 W power is supplied to a asbestos cement board with a thickness of 0.006m. Water of 60°C is circulating to protect the specimen with a diameter of 0.25m. Calculate the thermal conductivity of asbestos cement board

A composite wall consisting of four different materials is shown in Figure 2. Determine the heat transfer rate and all the interface surface temperatures (T2 and T3). Let the width of the wall be 1 m. 1 m K= 70 W/m°C T, = (200°C) · K = 100 W/m°C K = 70 W/m°C T2 L = 100°C K, = 20 W/m°C 1 m *L, = 4 cm→ L= 10 cm- →+L,= 5 cm» Figure 2

Approximately 106 discrete electrical components are placed on a single integrated circuit (chip) with electrical heat dissipation of q = 30,000 W/m². The chip, which is very thin, is exposed to a dielectric liquid at its outer surface, with ho = 450 W/m²/K and To= 20°C, and is joined to a circuit board at its inner surface. The thermal contact resistance between the chip and the board is R = 104 m² K/W, and the board thickness and thermal conductivity are L = 4 mm and 00,0 kb = 0.95 W/m/K, respectively. The other surface of the board is exposed to ambient air for which hi = 30 W/m²/K and T = 20°C. a) Provide a resistance diagram labeling appropriate variables associated with this problem. b) Determine a symbolic expression for the temperature of the chip T. c) Calculate the chip temperature for the given parameters. Coolant ho 00,01 Air Too,i hi 三 三 -Chip q Te -Thermal contact resistance, Re -Board, kp