In a combined heat and power (CHP) generation process, by-product heat is used for domesti...

In a combined heat and power (CHP) generation process, by-product heat is used for domestic or industrial heating purposes. Hot steam is carried from a CHP generation plant by a tube with diameter of 127 mm centered at a Square crosssection solid bar made of concrete with thermal conductivity of 1.7 W/m·K. The surface temperature of the tube is constant at 120°C, while the square concrete bar is exposed to air with temperature of −5°C and convection heat transfer coefficient of 20 W/m2·K. If the temperature difference between the outer surface of the Square concrete bar and the ambient air is to be maintained at 5°C, determine the width of the square concrete bar and the rate of heat loss per meter length. Answers: 1.32 m, 530 W/m

FIGURE P3-200