Ammonia vapor at 300 K and 1.062 MPa pressure condenses onto the outside of a horizontal tube. The tube has an O.D. of 1.91 cm.
a. Suppose that the outside of the tube has a uniform temperature of 290 K. Determine the average condensation heat transfer coefficient of the tube.
b. The tube is cooled by cold water flowing through it and the thin wall of the copper tube offers negligible thermal resistance. If the bulk temperature of the water is 275 K at a location where the outside surface of the tube is at 290 K, what is the heat transfer coefficient inside the tube?
c. Using the heat transfer coefficients you just found, estimate the largest wall thickness for which the thermal resistance of the tube could be neglected. Discuss the variation the tube wall temperature around the circumference and along the length of the tube.