Thermodynamic design and parametric performance assessment of a novel cogeneration solar organic Rankine cycle system with stable output

In areas rich in solar energy, meeting the energy requirement using renewable energy sources can address environmental issues by reducing the use of fossil fuels. In this study, thermodynamic design, simulation, daily and monthly evaluation of a novel cogeneration solar organic Rankine cycle (ORC) system with the capability of electricity and domestic hot water (DHW) production with stable output are performed under transient environmental conditions. The main components of the integrated system are a solar field based on parabolic dish concentrators (PDCs), a direct thermal energy storage (TES) system using two separate tanks, and an ORC power field which was modeled using TRNSYS software. In this system, intending to generate 200 KW of electricity, Benzene fluid in a recuperative ORC indicated a better performance than Cyclohexane, Toluene, and n-Hexane fluids with an energy efficiency of 21.89% and the lowest required inlet temperature for the turbine as 266.1 degrees C. The highest working hours of the system were obtained in the middle months of the year with an average DHW production of 12.8 h/day (more than 200 m3/day) and 9.1 h of electricity generation. While during the coldest month of the year (December), the system could provide 4.1 h of DHW with 74.5 m3/day of storage. Also, with the annual average of energy efficiency for the solar field as 78.9%, thermal and electric efficiency of the integrated system was calculated as 69.4% and 15.08%, respectively. From the economic analysis of the proposed system, the net annual benefit of the system and return of capital's period were calculated as 150,815.3 US$ and 7.3 years, respectively.

Automated summary

The study focuses on a novel cogeneration solar organic Rankine cycle system to meet energy demands in solar-rich regions using renewable energy sources, reducing reliance on fossil fuels. By utilizing a solar field and ORC, the system achieves improved energy efficiency, with stable output under varying environmental conditions. Economic analysis shows a net annual benefit of 150,815.3 US$ and a return of capital's period of 7.3 years for the proposed system.