Heat storage design and performance analysis of a parabolic trough thermal power generation system based on sectional heating collection

The integration of solar thermal utilization and energy cascade utilization can bring the possibility to increase the overall plant efficiency by decreasing the exergy loss while maintain a firm supply. This paper takes SEGS VI Plant and its improved plant using sectional heating as research object, two novel thermal energy storage subsystem structures were proposed and designed for the improved plant, to explore the enhancing effect of energy cascade utilization on commercial solar thermal power plants. Calculation models of the energy storage efficiency and collector field multiples of the thermal energy storage tank were established. This paper used the software Ebsilon to establish the simulation model of the commercial 30 MW solar thermal power plant with traditional thermal energy storage structure, the improved plants with two different thermal energy storage structures, and conducted the performance analysis of the plants under design and operating conditions. The results show that, compared with the system using traditional thermal energy storage structure, the overall plant efficiency of the improved plant adopt the novel thermal energy storage structure increased by 0.71% and 0.95% under design conditions day, the overall plant efficiency increased by 0.60% and 0.81% under operating conditions, which can realize the better use of energy. Simultaneously, the total capital investment cost and levelized cost of electricity also can be reduced by 6.77 M$ and 4c$/kWh, which has good application prospects.