This is problem 6-12 from El-Wakil’s Powerplant Technology book-- a condensing only feedwater heater uses 7/8-in-OD 90-10copper-nickel tubes. It receives 84,000 lbm/h of 95percent quality bled steam at 20 psia, and 160,000 lbm/hof drain from the next higher pressure heater at 240°F.3.9x106 lbm/h of feedwater goes through theheater at 7 ft/s, 2000 psia, and 195°F. The terminal temperaturedifference is 5°F. Determine the size, length, and number of tubesbased on a U-tube design. Take a maximum allowable stress in thetubes of 15,000 psi.
