Heat Duty For Steam Generator / Evaporator

[takiyasamsama]

Hi,

I had doubt in determining my heat duty for steam generator (not boiler). Basically for steam conversion (water to steam) the heat duty is determined by mass flow times the latent heat, however I was wondering shall I include duty for water heating from initial temperature up till saturation temperature? Logically I think total duty shall include duty from liquid side plus latent heat duty.

Previously I knew that to design a condenser just use the latent heat value since there is no desuperheating or subcooling therefore I just determine the duty using mass flow times the latent heat and voila! heat duty determined.

Appreciate the help and thanks in advance!

 

[Rspain]

Hi,

Consider average Enthalpy of net inlet water (net fresh make-up water income - not recirculated carryover condensate from separator - + codnensate recovered from process if at all- hotwell/degasser/high pressure condensate recovery tank), Enthalpy of outlet steam (after separator) and an overall energy efficiency of 90-92% (this is a conventional commercial 3-pass fired tube boiler) and you will be able to estimate roughly the total power you must feed into the generator.

Regards,
Roberto