Thermodynamic analysis, advanced non-linear dynamic simulation and multi-criteria optimization of a 100 MW parabolic trough solar steam power plant

Thermodynamic analyses of concentrating solar power plants and optimizing these cycles relying on the energetic and exergetic optimal efficiencies are quite common. However, it is found that just considering the efficiency of the system for performance optimization and neglecting the adverse effects of the plant's wrong operation timings, which is a function of the solar working fluid flow rate, can easily give misleading optimization results. This study's primary goal is to find the optimal operating point of the cycle in terms of the thermodynamic efficiencies considering the system's operating time. Thus, the Sliding Mode Control (SMC) approach is employed to provide a proper mass flow rate for the working fluid from the solar collector field to achieve a precise output temperature from the collectors in different operating conditions. Multi-objective optimization is performed using the Particle Swarm Optimization (PSO) algorithm. The results of power block sensitivity analysis indicate that a 70℃ increase in the solar collector outlet temperature remarkably enhances electricity generation and exergetic efficiency by 67 and 48%. The two-objective optimization shows 22.01%, 2.10%, and 5.46% enhancement in response time, thermal efficiency, and exergetic efficiency, and the three-objective optimization reveals 3.68% and 3.74% improvement in efficiency (thermal and exergetic), respectively.