Retrofittable Solutions Capability for Gas Turbine Compressors

The increasing introduction of renewable energy capacity has changed the perspective of operation of conventional power plants introducing the necessity of reaching extreme off-design conditions. There is a strong interest in the development and optimization of technologies, that can be retrofitted to an existing power plant to enhance flexibility, as well as increase performance and lower emissions. Under the framework of the European project TURBO-REFLEX, a typical F-class gas turbine compressor designed and manufactured by Ansaldo Energia has been studied. Numerical analyses were performed using the TRAF code, which is a state-of-the-art 3D CFD RANS/URANS flow solver. In order to assess the feasibility of lower Minimum Environmental Load operation, by utilizing a reduction in the compressor outlet mass-flow rate, with a safe stability margin, two different solutions have been analysed: blow-off extractions and extra-closure of Variable Inlet Guide Vanes. The numerical steady-state results are compared and discussed to an experimental campaign, which was performed by Ansaldo Energia. The purpose is to identify feasibility of the technologies and implementation opportunity in the existing thermal power plant fleet.