Implementing the Exhaust Gas Temperature Control Logic in Off-Design Calculations of Gas Turbine

Gas turbine exhaust gas temperature control logic affectsthe steady state performance of the gas turbine and itsbottoming-cycles and therefore, it should be included in thesteady state analysis such as off-design calculations. Theconventional method of implementing this control logic inthe off-design calculation is to use an external loop in thesolver algorithm that is numerically inefficient. This paperpresents a new equation that is developed in order to applythe exhaust gas temperature control logic into the off-designcalculations. This equation is a smooth function whichmakes it possible to be solved simultaneously with otherequations and therefore, there is no need for the externalloop any more. Consequently, the system of equations canbe solved faster and more robust. The results of thesimulations for a sample gas turbine show that thedeveloped equation could apply the gas turbine controlalgorithm to off-design calculations accurately in a widerange of operating conditions.