Performance analysis of solid heat accumulator used in tower solar thermal power generation system

Abstract

In recent years, solar energy, wind energy and other new energy sources have been highly praised, especially solar energy, which is considered as one of the cleanest renewable new energy sources, and solar thermal power stations have been built in many countries. Tower solar photothermal power generation is a heat absorber that reflects sunlight to the top of the tower through heliostat field. Molten salt absorbs heat through the heat absorber, heats water supply and promotes thermal power generation. However, solar energy is intermittent and unstable, so the tower solar thermal power station is equipped with heat storage molten salt tank. Solid heat storage technology has the advantages of cheap heat storage medium, no harm to the environment, strong reliability and operability of the system, and can provide cost-effective heat storage solutions for industrial process heat energy and power generation. In this paper, the molten salt tank is replaced by a solid heat accumulator. After the molten salt absorbs heat during the day, part of it heats the heat accumulator through the unit tube in the heat accumulator to store the heat in the heat accumulator, and the other part heats the water to promote the steam power cycle. At night, the heat accumulator heats the molten salt to release heat, which continues to promote the steam power cycle. In this paper, CFD software will be used to numerically simulate the change of temperature characteristics inside the solid regenerator with the time of heat storage and release, and draw the temperature nephogram and change curve.