A kind of particle/molten salt fluidized bed heat exchanger and method based on spiral bed surface

Abstract

A particle / molten salt fluidized bed heat exchanger and method based on a spiral bed surface, comprising a shell, a particle silo is arranged at the bottom of the shell, and a particle outlet is opened at the bottom of the particle silo, and the shell is sequentially arranged from bottom to top There are connected air chambers, spiral distribution plates, spiral fluidization chambers and separation chambers; the particle overflow pipe passes through the air chamber, and the inlet at the upper end of the particle overflow pipe is connected with the center of the spiral fluidization chamber, and the particles overflow The outlet at the lower end of the pipe is connected with the pellet silo; the side wall of the pellet silo is provided with a molten salt inlet, and the shell side wall is provided with a molten salt outlet, and the molten salt pipeline runs through the pellet silo, the pellet overflow pipe and the spiral fluidization cavity. The present invention can form a good countercurrent heat exchange between the fluidized particles and the molten salt by setting the spiral fluidization chamber, improve the heat transfer coefficient, avoid the solidification and decomposition of the molten salt in the heat exchange pipeline, and realize bed and inclined heat exchange The tube is efficient and fully heat exchanged.

Description

technical field [0001] The invention belongs to the technical field of fluidized bed heat exchange, and in particular relates to a particle / molten salt fluidized bed heat exchanger based on a spiral bed surface and a heat exchange method. Background technique [0002] Solar energy is the renewable energy with the largest stock and the widest distribution that can be developed at this stage. Taking my country as an example, the annual solar radiation exceeds 6 billion joules per square meter, and the annual acceptable radiation is equivalent to 1.7 trillion tons of standard coal. The potential for using solar power to generate electricity is huge. Due to the low energy density of solar energy, strong randomness and intermittent nature, direct photoelectric conversion faces problems such as unstable output and large impact on the power grid. Solar thermal power generation adopts the energy conversion path of light-heat-alternating current, which is better compatible with conv...

AI Technical Summary

Problems solved by technology

Increasing the number of tube bundles is beneficial to increase the temperature rise of the molten salt, but limited by the height of the bed, it is necessary to reduce the diameter of a single heat exchange tube. Due to the high viscosity of the high-temperature liquid molten salt, too small a tube diameter will significantly increase the Road pressure drop, resulting in increased power consumption of the molten salt pump

At the same time, too low flow rate of the molten salt in the capillary can easily cause the temperature of the molten salt film to be too high, resulting in thermal decomposition of the molten salt

However, reducing the number of tube bundles and increasing the diameter of a single tube will cause the molten salt flow rate to be too fast, and it is necessary to adopt multi-stage fluidized bed heat exchange to meet the requirements of molten salt temperature rise (such as the multi-stage fluidized bed heat exchange announced by invention patent CN109813124A technology), and this will increase the heat loss of the fluidized wind, the system will be larger and more complex, and the cost will be higher

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