Simulations of gas turbine performance: influence of gas-behaviour modelling

摘要

Several gas-turbine-behaviour simulation programs have been developed so far to predict gas turbines performances under design and off-design conditions. The focus of the present investigation is on addressing the effects of the different approaches to modelling the gases’ thermodynamic properties on the performance prediction of gas turbines, in particular that of the conventional and two-combustor engines. Unfortunately, the use of various different models has resulted in variations in the predicted values for a gas turbine's performance under identical conditions. Also, in the comparison of the performance of the two-combustor engine with that of the conventional engine, the use of various different gas-properties models has shown different outcomes; for example, the predictions using the considered constant-specific-heat model have revealed that the two-combustor engine operates with a higher thermal efficiency compared with what is achievable using by the baseline (conventional) engine, whereas the predictions using the modified and improved specific-heat models have shown otherwise. Hence, depending on the applications, the selection of prediction methodology and its gas (thermodynamic) properties model might result in misleading findings.