Investigation of water balance in water recovery of closed steam injection gas turbine cycles

An industrial gas turbine has the characteristic of decreasing output power on hot summer days while electricity demand peaks. Steam injection in gas turbines has been used for many years to prevent the loss of performance of gas turbines caused by high ambient temperature. Vodoley system is a Closed Steam Injection Gas Turbine Cycle (CSIGTC), which is known as a self-sufficient in steam production. In this study the influence of steam injection in Mashhad Power Plant GE-F۵ gas turbine parameters was experimentally investigated. Moreover a computer modelling has been used to study water balance in a CSIGTC system. The results show that although system has additional water treatment process, applying it increases thermal efficiency up to ۳۵.۳۳ percents for ۲۵ MW of power output at an ambient temperature of ۴۰ ˚C. Also water balance considerations show for a direct contact condenser of ۹۶% efficiency and the exhaust temperature of ۴۲۰ ˚C at turbine outlet, about ۷.۸ kg/s of make up water is needed under ISO rating of gas turbine (۱۰۱.۳ kPa, ۱۵ ˚C) which must be provided for the CSIGTC system. This amount of water is about ۵۱% of injected steam.