Nanofluid direct absorption solar steam generating device and method

Abstract

The invention discloses a nanofluid direct absorption type solar steam generating device and a method thereof; the nanofluid direct absorption type solar collection and steam are integrated, and an outer pipe adopts a coating-free U-type vacuum pipe (2); a sleeve steam happening pipe (5) is arranged in the U-type vacuum pipe, and nanofluid (4) is filled in an annular sealing cavity fully between the U-type vacuum pipe and the sleeve steam happening pipe. The evaporation medium is gasified to be steam and flowed out after absorbing heat of the nanofluid in the sleeve steam happening pipe. The inner pipe wall of the sleeve steam happening pipe is provided with a nozzle (7) and used for supplanting fluid and increasing the heat exchange coefficient. By using the light absorption property of the nanofluid, the solar energy is directly absorbed and medium-temperature steam is generated; meanwhile, the evaporation heat exchange and transfer performance is intensified, thereby fundamentally avoiding the shortcomings of high-temperature resistance and poor durability of the absorbing coating of a traditional heat collector; the invention is a novel high-efficient solar heat collecting technology integrated with heat absorption, heat transfer, heat loading, and steam happening together.

Description

technical field [0001] The invention relates to solar heat collection and belongs to the fields of solar heat utilization and steam generation. Background technique [0002] The type of medium-temperature collectors currently used is mainly a straight-through metal-glass vacuum tube structure. This structure is coated with a solar selective absorption coating on the surface of the inner tube of the heat collector. The coating absorbs solar radiation and then transfers heat energy to the inside of the tube. Heat collecting fluid, due to the poor temperature resistance and durability of the absorbent coating, the different thermal expansion coefficients of glass and metal, and the uneven heating of the tube wall in the circumferential direction during operation, it is easy to cause the heat collecting tube to rupture or leak, and the reliability and safety are low. The heat pipe vacuum tube solar collector uses the absorbing coating on the heat collecting tube wall or fins to ...

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Problems solved by technology

[0006] In order to improve the heat collection efficiency of solar energy at medium temperature and the efficiency of direct steam generation of solar energy, the invention solves the problem of poor high temperature resistance and durability of the absorbing coating of traditional solar heat collectors, and the increase of reversible loss caused by large heat transfer temperature difference. The large temperature difference can easily cause problems such as damage to the heat collecting tube. The present invention proposes a nanofluid direct absorption solar steam generating device and method, which can effectively improve the heat utilization efficiency and use solar heat to generate steam in the middle and low temperature areas.

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