Response characteristics of external receiver for concentrated solar power to disturbance during operation

Abstract

The practical operation of the receiver for solar power tower plant is under unsteady conditions because of the variation of direct normal irradiation, as well as the output power load. A 100 MW external receiver was designed and selected as the object. The unsteady one-dimensional model was established for the receiver and validated by comparing the simulation results with the published experimental data, aiming to launch the thermal, hydraulic and mechanical analysis. The heat transfer characteristics, thermal efficiency, as well as the thermal stress in the flow direction, are demonstrated by the static analysis. By comparison of different panels, the harsh working condition of the first and the last panels is discovered, including that of the highest temperature difference and tangential thermal stress along tubes. The tangential thermal stress is prominent at the light spot. The molten salt at the last panel is most likely to decompose. Dynamic simulation is carried out to analyze the thermal inertia and heat transport characteristics. The response curves and time constants of the receiver under step and periodical disturbances of different factors from the environment and load side are acquired. The thermal inertia of the receiver and its effect to dampen weather fluctuation are illustrated. These security problems and thermal performance will make demands on the control strategy and control accuracy. The results can provide a reference for the control strategy development of the solar power tower plant.