Thermal Analysis of Gas Turbine Engines With Intercooling and Regeneration

Abstract

In many modern gas turbine engine ground based power plants, utilized for the production of mechanical power, several auxiliary systems are integrated with the main gas generator with the aim to improve the generated output power or to reduce the fuel consumption. Two of the most important practices used to achieve these goals are regeneration and intercooling. The first consisting in recovering part of the enthalpy present in exhaust gas to pre heat air before introducing it into the combustion chamber, the second consists in cooling the air during the compression process so to reduce the compression work needed, and consequently obtaining more power at the output shaft. These practices are not utilized in gas turbine engine for propulsion systems mainly for the extra weight and size due to the presence of the heat exchangers and for the more complicated flow pattern that it comes from it. However if we imagine to overcome these difficulties, by means, for instance, of compact heat exchangers that new technology seems to be able to manufacture, the same benefits obtained for the ground based plants could be obtained in propulsion systems. In particular turboprop engine seems to be the most suited to this purpose thanks to its smaller mass flow rate and its gas path. A thermodynamic cycle analysis is performed to put in evidence the advantages, in terms of power increase and fuel consumption reduction, of the