Page 25 - Advanced Gas Turbine Cycles

2 Advanced gas turbine cycles

FUEL ENERGY
SUPPLIED F

POWER
WORK W

HEAT REJECTED QA

Fig. 1.1. Basic power plant.

shown in the figure. The many variations of this basic cycle form the subject of this
volume.
An important field of study for power plants is that of the ‘combinedplunt’ [I]. A broad
definition of the combined power plant (Fig. 1.5) is one in which a higher (upper or
topping) thermodynamic cycle produces power, but part or all of its heat rejection is used
in supplying heat to a ‘lower’ or bottoming cycle. The ‘upper’ plant is frequently an open
circuit gas turbine while the ‘lower’ plant is a closed circuit steam turbine; together they
form a combined cycle gas turbine (CCGT) plant.

Exhaust
gases

I Controt
;/surface z
Co nt ro I

1- - - - - - - -

water
Fig. 1.2. Closed circuit gas turbine plant (after Haywood [3]).