On thermodynamics of gas-turbine cycles. I - Second law analysis of combined cycles

While the application of the second law of thermodynamics in the form of entropy and availability balances for components and processes can locate and quantify the irreversibilities causing loss of work and efficiency, the complications involved in combustion irreversibility have forestalled widespread engineering use of this method. Attention is presently given to a cycle analysis method which circumvents these combustion cycle difficulties, as demonstrated through application to complex combined cycles with intercooling and reheat stages. Fuel is treated as a heat source that supplies potentially available work to the cycle, depending on the peak temperature constraint on work extraction; availability is then traced as it cascades through the cycle. Analysis and results for combined cycles are presented.