Dynamic modeling and behavior of parabolic trough concentrated solar power system under cloudy conditions

As a promising application of solar energy, parabolic trough concentrating solar power with indirect thermal energy storage has been widely used in concentrating solar power plants constructed in China. The dynamic modeling and behavior of the power plants were important for achieving fast start-up and shut down and to overcome weather disturbances. This study investigated the dynamic characteristics of a 50 MW parabolic trough concentrating solar power plant with indirect thermal energy storage. Simplified cloud disturbances were simulated to obtain the dynamic characteristics of a power block coupled with solar field and thermal energy storage. Simulation results indicated that the thermal inertia of solar field is an order of magnitude larger than that of power block and thermal energy storage subsystems, and the heat transfer fluid temperature at the solar field outlet fluctuates within a narrow range at rated value under the control scheme of solar field. The disturbances caused by heat transfer fluid temperature fluctuation were reduced by thermal energy storage operation. To minimize the generation load fluctuation under thick-cloud condition, the thermal energy stored in solar field could be used to moderate the fluctuation caused by the start-up of thermal energy storage discharging exchanger. (C) 2019 Published by Elsevier Ltd.