Assessment of Solar Gas Turbine Hybridization Schemes

Abstract

A simulation environment allowing steady state and transient modeling is used for assessing several gas turbine based cycles proposed for solar hybridization. First, representative open cycle gas turbine configurations, namely, (a) single shaft (SS), (b) recuperated single-shaft, (c) twin shaft (TS), and (d) two-spool three-shaft, intercooled, recuperated, are evaluated. The importance of design point selection in terms of solar share value is highlighted. Solar steam injection gas turbine cycle (STIG) alternatives, namely, solar steam only and solar/fuel gas steam, are then assessed. Finally, the concept of a dual fluid receiver (DFR) for exploiting the rejected solar power by producing steam during sunny hours with high irradiation is demonstrated. The effects of hybridization on performance and operability are established and evaluated. Solarization effect on performance is estimated in terms of annual produced power and fossil fuel savings. The results indicate that the spool arrangement affects the suitability of a gas turbine for hybridization. Recuperated configurations performed better for the design constrains imposed by current technology solar parts. Solar steam injection is a promising solution for retrofitted fuel-only and conventional STIG engines.