My boss asked me to calculate the fuel savings of our boiler if we use a pumptrap right after the heat exchanger in a process equipment. The condensate is to be returned back to the boiler via a condensate tank.
Can anybody help me on this?
I presume that you are not recovering the condensate so far and will start now and total quantity of condensate is fed back to the BFW tank(no flash steam business).
check the temperature of boiler feed water before condensate feed and check its corresponding enthalpy from steam tables.
Now check the enthalpy of condensate at the condensate pressure.
The heat input to the BFW is mx(h1-h2), where m is mass flow rate of condensate, h1 is enthalpy of boiler feed water before adding condensate and h2 is enthalpy of condensate.
Your fuel savings(quantity) will be NCV(net calorific value)/[mx(h1-h2)]. Use appropriate units for the calculations.