Design and optimization of a novel solar cooling system for combined cycle power plants

This paper presents the design of a novel Solar Assisted Combined Cycle power plant. The system includes a solar loop equipped with a double stage absorption chiller driven by high-temperature high-vacuum non-concentrating flat-plate solar thermal collectors. The solar loop is coupled to a single-pressure Combined Cycle power plant. The cooling energy produced by the absorption chiller is used to cool gas turbine inlet air, aiming at enhancing system efficiency and electrical capacity. This Solar Assisted Combined Cycle arrangement is analysed through a dynamic system simulation and a thermoeconomic analysis is performed aiming at determining the optimal set of design and operating parameters. This original configuration was numerically analysed in TRNSYS, developing a suitable dynamic simulation model to predict system performances. Suitable dynamic models are implemented for all the cothe mponents included in the system. The simulation also includes a thermoeconomic model which accurately evaluates system capital and operating costs as a function of design and operating parameters. The results show that a very high thermal efficiency of solar collectors, on average equal to 34%, is achieved. Results from the economic point of view were also satisfactory. In fact, the pay back period was about 8 years in the best case.