Page 125 - Handbook of Energy Engineering Calculations

computed by taking an energy balance about the economizer. Or, H − H =
6
7
w (H − H ). Using the actual values for the enthalpies, solve this equation
5
4
g
for w .
g
With w known, the other factors in the efficiency computation are
g

FIGURE 3 Energy-flow chart of the gas turbine–steam turbine cycle
in Fig. 1.

The bleed-steam flow m is calculated from an energy balance about the
feedwater heater. Note that the units for the above equations can be any of
those normally used in steam- and gas-turbine analyses.

Calculation Procedure:

1. Find the amount of oxygen required for complete combustion of the fuel
Eight atoms of carbon in C combine with 8 molecules of oxygen, O , and
2
8