Chapter 13 Gas Turbine Power Plants

fuel-air ratio, the net power developed, and the specific fuel consumption.
The lower heating value of the fuel is 43,100 kJ/kg.
13.19 A Brayton cycle with gas generator and a power turbine
uses air as the working substance, the mass flow rate of air is 32
kg/s. At the compressor inlet p 01 = 1 ami and T 01 = 300°K, and at
the H.P. turbine inlet p 03 = 21 atm and T 03 = 1573°K. The power
output of the L.P. turbine is 10 MW. For the gas generator compressor
and turbine efficiencies are 0.8. The exhaust temperature
from the power turbine is 789°K. Assuming that y varies with
average temperature in each process and using (11.5), determine
the power turbine efficiency, the pressure and temperature at the
power turbine inlet, the cycle thermal efficiency. Hint: The work
of the H.P. turbine equals the compressor work.
13.20 A Brayton cycle with intercooling uses air as the working
substance. At the compressor inlet p 01 = 1 atm and T 01 = 300°K,
and at the turbine inlet p 03 =10 atm and T 03 = 1100°K. The first
compressor stage discharges air at a pressure of 3 atm, and the
intercooler cools the air down to 300°K. The mass flow rate of air
is 0.2 kg/s, and the two compressors and the turbine have efficiencies
of 0.85. Assuming that y varies with average temperature
in each process and using (11.5), determine the required compressor
power with and without intercooling. Also compute the
net power output with and without intercooling.
13.21 A regenerative gas turbine, which also utilizes reheating
and intercooling, develops a net power output of 3665 kW. Air at
14.7 psia and 530°R enters the compressor and is discharged from
the first stage at 60 psia and 840°R. The air enters the second
stage at 530°R and is discharged from the second stage at 176
psia and 760°R. The air then passes through a regenerator from
which it exits at a temperature of 1335°R. The turbine inlet temperature
is 2200°R, and the gas leaves the first turbine stage at 60
psia and 1745°R and is reheated to 2200°R. The turbine exhaust