Abstract:
The work presented in this thesis is a contribution to the study of the production of
electricity by a hybrid thermal power plant exploiting the solar field on the one hand and
natural gas on the other hand.
This work concerns firstly the evaluation of the thermodynamic performances of a solargas hybrid thermal power system with a power of 150 MW, the method of energy analysis
was used in this thesis. This method is used to determine the main parameters in order to
achieve improvements in system performance. The development of the analysis model in this
thesis is carried out by determining the thermal and solar efficiency as well as the efficiency
of solar electricity. Due to the calculation of the thermal and solar performances in typical
days and an average of the days of the year, we used simulation software "Aspen Plus" to
determine the thermodynamic parameters of the hybrid plant in the case of Algerian weather
conditions. As well as the System Advisor Model (SAM), this gives a methodology and
information particularly on cylindro-parabolic shapes concerning the part of the solar field in
the system studied. The results are calculated hour by hour from sunrise to sunset. The second
part of this work is being improved in the overall efficiency of the plant with two levels of
pressure that directly affects the capacity of the steam turbine in the power block. In the third
part, an optimization of the power at the level of the steam turbine is also carried out. The
optimization was carried out in the power block which contains two gas turbines and a double
pressure steam cycle where the high pressure part is only heated. Preliminary simulations for
this system have shown that the steam turbine cycle can achieve optimum conditions for
reheating and low vapor pressure, which would enhance the performance of the system. The
fourth part concerns the comparison of the key parameters of the thermal power plant in
different sites based on the economic factor (LCOE), the configuration of the solar field
section and the line spacing or the so-called effect of shading. The exploitation of the "Aspen
plus" and "SAM" software enabled us to establish models of optimal hybrid power plants
(solar-gas) in the arid zone of Algeria. Such a study is a reference for the construction and site
selection of the installation of this type of power plant.
