Feedwater Heater "Duty"?

Actually, Not. I have always felt that the "duty" in regards to heat exchangers referred to the thermodynamic heat transfer crossing a boundary. Energy. With respect to heat exchangers, the duty (I thought) was the Btu/hour crossing from one fluid of the heat exchanger to the other, as those are the units used. With feedwater heaters, however, I have found cases where that did not quite match. I thought, perhaps, that for a FWH, it only accounted for the energy in the extracted steam, and not the drips from the higher pressure FWH's. I am really not sure of the definition of "duty" for a heat exchanger, or for a Feedwater Heater in a Rankine Cycle. If someone has an official authentic definition in this regard, it would be appreciated. Thank You, sincerely.

Oh, I understand a little better what your looking for, and I can't help you. However a Google search of "Feedwater Heater in a Rankine Cycle" turned up some interesting stuff that might be of help. Good luck!

Duty would refer to what it takes to finish the task demanded of it and recover to do it again.

Thank you dadw5boys, Your statement suggests an alternative definition to consider. I appreciate that.