A pipe carries a liquid at 15 °C from a unit situated outside an industrial plant to equipment inside a building. The pipe has an inside diameter of 30 mm and wall thickness of 2 mm that is made from copper (thermal conductivity of 395 W/mK). The pipe is covered with a 10 mm thick layer of insulation which has a thermal conductivity of 0.1 W/mK. The temperature of the environment in the building is 20 °C. The convective heat transfer coefficients are 950 W/m2K on the liquid side and 15W/m2K on the air side.
(a) Calculate the heat loss per unit length of the pipe to the factory building environment. [8 marks]
(b) Calculate the temperature of the pipe wall adjacent to the insulation. [4 marks]
The insulated pipe exits the building and is exposed to the outside air temperature at 40 °C and a wind speed of 9 m/s.