Determination of maximum recoverable heat in a thermodynamic combined cycle (solar-gas) with a steam turbine downstream the power plant

Abstract

The purpose of this study is to develop a mathematical program for analysing the performance of the first integrated solar combined cycle system (ISCCS) in Algeria, located in Hassi R’mel. In this project, an integrated plant with simple pressure level is proposed. During sunny periods, the energy conversion of the exhaust gas in the steam turbine is improved by using solar heat steam generator HSSG in parallel with the heat recovery steam generator HRSG. This design furnishes flexibility in the operation system where it works as a conventional combined cycle during night time and it switches to operate as an ISCCS during daylight. Thermal efficiency and electricity generating are the main parameters to evaluate the instantaneous performances of different parts of the solar power plant through the year. The program results show that the power plant would produce about 134MW with efficiency equal to 57.5% at night. At daytime, the net solar electricity ratio can be very interesting and reach the limit of 15% at the design point. As a result, the output from and the efficiency of the integrated plant will be above the CC regime by 17 and 16.5%, which correspond to 157MW and 67%, respectively. Increasing the steam turbine capacity by 50% and better performances of the integrated plant in Hassi R’mel desert in warm days are other advantages of the proposed design