A cylinder of diameter 0.6 m and length of 15 m with surface
temperature of 200 Celsius is enclosed in a square of 1.2 m side,
the material having a thermal conductivity of 2.5 W/mk. the outside
surface at 5 Celsius . Determine the heat loss in W
A cylinder of diameter 0.6 m and length of 15 m with surface temperature of 200...
2.24 A pipe of 0.3 m outer diameter at a temperature of 160°C is insulated with a material having a thermal conductivity of k = 0.055 (1 + 2.8 × 10–3T) W/mK where T is in °C. The outside surface temperature is 40°C. Determine the heat flow/m length and the temperature at the mid radius
Exercise 1.16 An insulated district heating pipe with a total diameter d = 0.4 m is laid in the ground at a depth of h = 1.2 m. For a long cold period with an average ground surface temperature of 0°C and a temperature at the outer edge of the pipe insulation of 20°C, the heat loss per 1km of steam pipe must be calculated. The thermal conductivity of the soil should be assumed to be 0.6 W/mk
Exercise 1.16...
The surface of a furnace wall is at a temperature of 1350oC. The outside wall temperature is 42oC. The furnace wall is made of 25 cm of refractory material having a thermal conductivity of 1.4 W/moK. The outside wall is steel, 1 cm thick with thermal conductivity of 47 W/moK. Calculate the thickness in meters of brick to be installed in between the refractory material and steel if its thermal conductivity is 0.28 W/moK and the heat loss is not...
(13) A brewery fermentation tank 12 m in diameter is situated in a room, which has a temperature of 15°C. The tank is constructed of 10-mm welded steel plate with 12-mm glass lining. The temperature at the inner surface of the glass lining is 50°C. Assume that the convective resistance offered by the air film on the outside of the tank equals the combined resistance of the glass and steel. The thermal conductivity of glass is 0.80 W/mK and that...
6 Water is heated in a pipe by exchanging heat with a warmer fluid that flows outside the pipe. Inside diameter of the pipe is dn 0.045 m and outside diameter dour0.05 m. Mean velocity of the water in the pipe is um-0.31 m/s and the bulk temperature is 323 K (density 988 kg m-3; viscosity 0.00055 kg m' sı. Pr 3.56, thermal conductivity k 0.64 W m1 Kt). The material of the pipe has thermal conductivity k 0.61 W...
heat and mass transfer
(20 points) Air at 25°C cools a 2170 cylindrical battery (with a diameter of 21 mm and a length of 70 mm) with a cross flow velocity of 6 m/s. a) Determine the average convective heat transfer coefficient. (b) If the battery's internal heat generation is 5W and its thermal conductivity is 0.6 w/m-k, the determine the battery surface temperature and the maximum temperature in battery
(20 points) Air at 25°C cools a 2170 cylindrical battery...
a) what is the heat loss per unit length from the pipe in
W/m?
b) Estimate the heat loss per unit length if a 50 mm thick layer
of insulation with a conductivity of 0.058 W/m K. Neglect radiation
for this part.
3. A 0.20-m diameter, thin-walled steel pipe is used to transport saturated steam at a temperature of 486K in a room for which the air temperature is 25°C and convection heat transfer coefficient at the outer surface of...
3. A water heater is covered with insulation boards over a total surface area of 3 m. The board is 5.3 centimeter thick. The inside board surface is at 69'C, and the board material has a conductivity of 0.08 W/m-K. If the heat loss is 200 W, determine the outside surface temperature. Given A= 3m? T= 69°C Tonto? K= 0.08 W/mk Q=2oow 4. Determine the total rate of heat transfer from a person standing in a breezy room at 20°C...
1. Heat is generated at a uniform steady rate in a long solid cylinder. The cylinder loses heat from its exposed surface to surroundings at constant temperature. Show that the radial temperature profile in the cylinder can be represented by the equation: T, = Twer - 9 4k where qy is the rate of heat generation per unit volume and Tur is the maximum temperature in the profile. [30%] In a long solid cylinder of 40mm diameter heat is generated...
1. A steel tube [k 15 W/(m.°C)] of outside diameter 7.6 cm and thickness 1.3 cm is covered with an insulation material [k 0.2 W/(m. C)] of thickness 2 cm. A hot gas at 320°C with a heat transfer coefficient of 200 W/(m2.C) flows inside the tube. The outer surface of the insulation is exposed to cooler air at 20°C with a heat transfer coefficient of 50 W/(m2·°C). Calculate a) The heat loss from the tube to the air for...