A 2.5-cm-OD hot steam line at 100?C runs parallel to a 5.0 cm OD cold water line

Question:

A 2.5-cm-OD hot steam line at 100?C runs parallel to a 5.0 cm OD cold water line at 15?C. The pipes are 5 cm center to center and deeply buried in concrete with a thermal conductivity of 0.87 W/(m K). What is the heat transfer per meter of pipe between the two pipes?GIVENA hot steam line runs parallel to a cold water line buried in concreteHot pipe outside diameter (Dh) = 2.5 cm = 0.025 mHot pipe temperature (Th) = 100?CCold pipe outside diameter (Dc) = 5.0 cm = 0.05 mCold pipe temperature (Tc) = 15?CCenter to center distance between pipes (l) = 5 cm = 0.05 mThermal conductivity of concrete (k) = 0.87 W/(m K)ASSUMPTIONSTwo dimensional heat transfer between the pipesSteady state conditionsUniform thermalconductivity