A condenser heat exchanger with a tube (inner diameter 25.4 mm, length 5 m) uses cooling water at 1.5 m/s; the cooling water is initially at 290K upon entrance. The inner tube-wall temperature is constant at 370K by a condensing steam on the outer surface.

(A) What is the water exit temperature? What is the heat transfer rate? (25 pts)

(B) If saturated steam at 373K (100 C) is used on the shell side, how many thermal resistances are in the system? What can you say about the magnitude of these resistances given the temperature information? (3 pts) Show using a different approach that this is true (i.e. not using temperature to justify). (5 pts)

(C) What is the rate of water condensate the condenser generates? (4 pts)

(D) If the steam is flowing at 0.05kg/s, which of the assumptions above would be different and why? (3 pts)

(E) For the scenario in part B, draw the temperature profiles of the cooling water as a function of radial position, at three axial positions (near the entrance, somewhere in the middle of the tube, and near the exit). (Use the y axis for temperature and x axis for the radial position; draw all three profiles on the same graph. Label them.) (6 pts) Draw the tube and draw the momentum and thermal boundary layers. (4 pts) How would the local heat transfer coefficient change as a function of axial position? (3 pts) What about local heat transfer rate? (2 pts) Please justify your answer.

(F) If a 4-tube-pass single-shell-pass unit is used instead to achieve the same exit temperatures, how much longer/shorter is the tube (of the 4-tube-pass) would you need? (15 pts)