Boiling heat transfer coefficient

[Ronevol]

I am doing a calculation on a verticle, 1,1-shell and tube heat exchnager. 25% of the saturated boiler feed water(shell side) was vapourize. How to calculate the heat transfer coefficient of the shell side.

 

[hacksaw]

it boils down to allowing for extra tube area to account for steam blanketng effect. your supplier has design factors that can be applied.