Direct absorption solar heat collector based on secondary reflection concentrating system

Abstract

The invention relates to a direct heat absorbing type solar heat collecting device based on a secondary-reflection focusing system. The direct heat absorbing type solar heat collecting device comprises an upper cone frustum, a heat absorbing cavity, a high-temperature molten salt buffer tank and a low-temperature molten salt buffer tank; multi-area partition plates are arranged in a cavity of the upper cone frustum; high-temperature molten salt outlet devices are arranged on the inner lateral wall and at the bottom of the upper cone frustum; a graphite heat accumulating column is arranged in the high-temperature molten salt buffer tank; a molten salt steam filtering device and a high-temperature air circulating device which are communicated with each other are arranged on the outer lateral side of the upper cone frustum; a reinforced heat absorbing and exchanging device is arranged in the heat absorbing cavity; a thermal insulation layer is arranged at the periphery of the heat absorbing cavity; a supporting structure is arranged outside the thermal insulation layer; a flow distributing plate is arranged at the bottom of the heat absorbing cavity; a low-temperature molten salt lower cavity is arranged under the flow distributing plate; the low-temperature molten salt lower cavity is connected with a low-temperature molten salt storing tank through a low-temperature molten salt inlet pipeline; the graphite heat accumulating column is arranged in the low-temperature molten salt storing tank. The direct heat absorbing type solar heat collecting device is high in heat absorbing efficiency, accurate and controllable in temperature of a heat transfer work medium outlet, simple to operate and free of side effect on surrounding environment and can operate in normal pressure.

Description

【Technical field】 [0001] The invention relates to a solar heat collecting device, in particular to a direct heat absorption type solar heat collecting device based on a secondary reflection concentrating system. 【Background technique】 [0002] Fossil energy is the main energy source of modern industry. After more than a century of continuous large-scale mining, its reserves are decreasing day by day, and the use of fossil energy has also brought about increasingly serious environmental problems, such as the greenhouse effect and long-term air pollution in large areas. The development of renewable clean energy is of great significance to the sustainable development of energy. As a new type of clean energy, solar energy is very promising as an important part of basic energy in the future. [0003] Large-scale solar power plants mainly have two forms of energy conversion: photovoltaic and photothermal. Among them, photothermal power stations can be divided into three types: to...

AI Technical Summary

Problems solved by technology

The device has a simple structure and has the function of integrating heat absorption and heat storage, but the device has a large volume, a large loading capacity of molten salt, and the functions of flow regulation and working fluid temperature control are relatively lacking.

US Patent WO2010083285 proposes an integrated solar energy direct absorption and heat storage device based on secondary reflection, including molten salt storage tank, molten salt, molten salt storage tank opening, secondary reflection device, heat exchange tube and agitator, melting Salt is only used as a heat-absorbing and heat-storing working medium. The heat in the large molten salt storage tank is exported by using the heat exchange tube. The heat exchange tube is immersed in the heat-absorbing working medium. Hot molten salt output as heat transfer fluid

[0005] The characteristics of the secondary reflection solar spot are high energy flow density in the center area and small energy flow density in the edge area. The solar flow is mainly concentrated in the center area of ​​the spot. The design of the heat absorber should take into account the synergistic effect of the flow field and the temperature field, and precisely control the working fluid. Outlet temperature, improve heat absorption efficiency, and prevent local overheating, the existing technology is difficult to achieve this technical effect

In addition, the vapor pressure of molten salt is low at high temperature, but in a large-scale open heat absorber, its evaporation is still considerable, which is not conducive to environmental protection and operation safety. The above two heat absorbers have not solved this problem

Images