Design, 3E scrutiny, and multi-criteria optimization of a trigeneration plant centered on geothermal and solar energy, using PTC and flash binary cycle

Abstract

A hybrid solar-geothermal power plant for electricity, heating, and cooling is provided in this paper. A flash-binary geothermal cycle, parabolic trough solar collectors, auxiliary heater, single effect LiBr-water absorption chiller, and heat exchangers are all part of the planned integrated power plant. The plant provides steady electrical power as well as the necessary heating and cooling for the yeast industry. The solar-geothermal power plant's energetic and exergetic efficiencies for the proposed system under steady-state conditions with constant irradiation are 10.78 percent and 23.1 percent, respectively. The auxiliary heater is found to function in 85 percent of the year due to the inability of solar energy to increase the fluid temperature to the necessary amount throughout several periods of the year. The impacts of different performance factors on the system's exergetic efficiency and overall cost rate are also evaluated using parametric analysis. It was discovered that parameters such as the flash separator's inlet pressure and temperature, the pinch point temperature difference in the heat recovery steam generator (HRSG), and the geofluid outlet temperature in the heat exchanger 1 (HX1) have a significant impact on the system's exergetic efficiency and total cost rate. Furthermore, the effect of variations in sunbeam irradiance on assessment parameters is examined. In constant heat input to the cycle, increasing beam irradiance results in increased total exergy efficiency and a lower overall cost rate of the system. By raising the sunbeam irradiance, the proportion of the auxiliary heater in the plant's energy supply and the mass flow rate of the fuel would be reduced. Also, the optimization findings show that the exergy efficiency of 33.8 percent might be attained under ideal operating circumstances.