Performances of a gas turbine power plant with a direct evaporative saturator

• Effect of direct evaporative saturator (DES) on gas turbine (GT) plant performance. • Analytical assessment of inlet air and water temperature impacts on DES efficacy in GT power plant. • Evaluation of waste heat recovery strategies for optimizing DES and GT plant efficiency. • Case study application of DES in an SGT-750 gas turbine for performance demonstration. One way to improve the performance of gas turbine power plants is to saturate the compressed air (from the compressor) before it enters the combustion chamber, using a saturator. Indeed, utilization of an air saturator has the potential to augment the enthalpy within the combustion chamber, which may ultimately lead to an enhancement in the overall performance of the gas turbine. A direct evaporative cooler (DEC) is proposed as the saturator, i.e. DES for the GT plant in this study. The impact of the DES on the performance of the GT power plant has been studied in general through a sensitivity analysis and specifically through a case study, using an analytical model developed in this study and programmed in Engineering Equation Solver (EES) software. It has been demonstrated that increasing the inlet air and water temperatures in a DES system can lead to a notable enhancement in the performance of a gas turbine. The findings of the study indicated that the utilization of a DES could result in an increase of up to 7 % in power output and thermal efficiency of the GT in comparison to a gas turbine that does not possess a saturator. This improvement is achievable if waste heat is partially recovered through a heat recovery system (HRS) and employed for the purpose of preheating both the compressed air and water that are entering the DES. This improvement is approximately 6 % and 4 % respectively, if only the saturator inlet water or air temperatures were increased separately.