Modeling of a hybrid solar micro gas-turbine power plant

This work proposes a hybrid system based on gas turbine or steam/gas plant integrated with a solar field either to provide a part of the heat addition or to replace the combustor in the case that the only solar heat input is enough to ensure that the working fluid reaches the turbine inlet temperature. The system can operate in a pure combustion mode when solar irradiance is weak during some hours in the day or seasons. A thermodynamic model for a hybrid solar gas-turbine power plant is presented. The system consists of a micro gas turbine (100 - 110 kW) supported by a solar field to integrate heat for the regeneration and combustion through heat exchangers. In this way, a hybrid thermal energy supply is considered, combining the use of biogas with thermal power from a solar field. The methodology is based on a combined thermodynamic - CFD based approach. The overall plant performance is estimated by the Thermoflex software, a modular program that allows assembling a model with several components. In a second phase, the authors have carried out a CFD analysis of the reacting flow through the micro GT combustor when supplied with a typical biogas from anaerobic digestion in replacement of the conventional natural gas, in order to check the combustion effectiveness and the environmental impact of the gas turbine at several load levels and ambient conditions. The CFD modeling is performed by using the Fluent flow solver