A NEW ANALYSIS OF RECUPERATIVE GAS-TURBINE CYCLES

It is shown that the classical recuperator effectiveness is not an app ropriate evaluation criterion for the gas turbine recuperator or a sui table independent thermodynamic parameter of the recuperative gas turb ine cycle. Another parameter-the average heat transfer temperature dif ference in the recuperator-is recommended as the new criterion instead of the recuperator effectiveness. Therefore, the original classical a nalysis results of the recuperative gas turbine cycle are also inappro priate and it is necessary to give a new analysis. In this paper, the analytical expressions of the simple recuperative cycle efficiency and the optimum pressure ratio based on the new criterion are derived fro m general simplified assumptions. Some typical calculation results are also presented. With this new criterion, the optimum pressure ratio v alues for efficiency of a simple recuperative gas turbine cycle do not vary very much with the temperature ratio and are approximately equal to 3, much lower than the figures generally recognized before. A simi lar analysis for the recuperative gas turbine cycle with intercooler a nd reheater and an analysis ensuring approximately constant recuperato r heat transfer area per unit power output are given also.