[EN]Concentrated solar power (CSP) is one challenging renewable technology for
the production of electricity. Within this concept central receiver solar plants
combined with gas turbines are being investigated because of their promising
efficiencies and reduced water consumption. Hybrid plants incorporate a combustion
chamber in such a way that in periods of low solar irradiance power
output can be kept approximately constant and so, electricity production is
predictable. An integrated, non-complex solar thermodynamic model of a
hybrid gas turbine solar plant is developed employing a reduced number of
parameters with a clear physical meaning. The solar subsystem is modeled in
detail, taking into account the main heliostats field losses factors as cosine
effect, blocking and shadowing, or attenuation. An heliostat field with polar
symmetry together with a cavity receiver are considered. The model is
implemented in our own software, developed in Mathematica language, considering
as reference SOLUGAS solar field (Seville, Spain). Heliostats field configuration
is determined for the design point and its associated efficiency is
computed. First, an on-design analysis is performed for two different working
fluids (dry air and carbon dioxide), for recuperative and non-recuperative
modes. A pre-optimization process is carried out regarding the pressure ratio
of the gas turbine for different configurations. Some significant efficiency and
power rises can be obtained when pressure ratio is adapted for each specific
configuration and working fluid. Maximum achievable plant overall efficiency
is 0.302 for both fluids in the recuperative mode, taking a pressure ratio of
7 for dry air and 16 for carbon dioxide. In non-recuperative configurations
maximum overall efficiency is obtained for dry air, about 0.246. Moreover, a
dynamic study is performed for four representative days of each season. Then,
efficiencies and solar share are plotted against time. In addition, fuel consumption
and greenhouse emissions are computed for all seasons
