The optimum pressure ratio for a combined cycle gas turbine plant

摘要

A graphical method of calculating the performance of gas turbine cycles, developed by Hawthorne and Davis (1), is adapted to determine the pressure ratio of a combined cycle gas turbine (CCGT) plant which will give maximum overall efficiency. Theresults of this approximate analysis show that the optimum pressure ratio is less than that for maximum efficiency in the higher level (gas turbine) cycle but greater than that for maximum specific work in that cycle.Introduction of reheat into the higher cycle increases the pressure ratio required for maximum overall efficiency.