Copper tubes 25 mm in diameter and 0.75 m long are used to boil saturated water at 1 atm.
(a) If the tubes are operated at 75% of the critical heat flux, how many tubes are needed to provide a vapor production rate of 750 kg/h? What is the corresponding tube surface temperature?
(b) Compute and plot the tube surface temperature as a function of heat flux for 0.25 qs"/q"max 0.90. On the same graph, plot the corresponding num- ber of tubes needed to provide the prescribed vapor production rate.