A General Performance Model for the Open-Loop Water-Cooled Gas Turbine

A thermodynamic efficiency analysis of a simple open cycle, open-loop, water-cooled gas turbine is presented. Losses due to water pumping work, mixing of water and steam with turbine gas, and heat transfer from the gas are included. To achieve generality and provide system design guidelines, the results are presented in terms of dimensionless variables. It is shown that system performance is strongly influenced by water tip exit quality. Sample calculations reveal the optimum turbine inlet temperature for different pressure ratios using typical values of the dimensionless parameters. The results are presented for two different approaches: either the tip quality is treated as a given quantity or it is calculated using a model for the channel critical heat flux. The sensitivity of the cycle efficiency to each parameter is reported. The influence of water collection on cycle efficiency is assessed.Copyright © 1982 by ASME