investigation of a prototype industrial gas turbine combustor using ...

2. Gas Turbine Combustor
Figure 2.1: The SIT gas turbine, SGT-750, in which the full-scale version
of the combustor investigated in this thesis operates. (Courtesy of
Siemens Industrial Turbomachinery [SIT].)
(Figure 2.2).
In the ideal Brayton cycle diagram, Figure 2.2, it can be seen that
the temperature is increased from position 1 to position 2 because of the
isentropic compression of the gas by the ideal compressor. Heat is then
added via combustion at constant pressure, thereby further increasing
the temperature. The expander then reduces the pressure from P 2 to P 1
and the temperature drops. The area inside the cycle in the T-S diagram
equals the work output of the cycle. The efficiency of the cycle equals
the work done divided by the heat input (2.1).
η GT = W out
Q in
, (2.1)
Maximizing work output can be achieved by maximizing the area of the
Brayton cycle (Figure 2.2). This can be done by maximizing the difference
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