A heat capacity heat exchange device

Abstract

A heat capacity heat exchange device comprises a first shell (1) arranged inside, a second shell (2) arranged outside, a heat exchange media (4) and a heat capacity media (3). A space between the first shell (1) and the second shell (2) is fully or partially filled with the heat capacity media (3); external energy transfers to the heat exchange media (4) through the heat capacity media (3), and accordingly heat collecting of the heat exchange device is completed. The heat capacity heat exchange device has wide usable ranges, can be used for the solar heat utilization field of a groove-type optothermal heat collector, a Fresnel array optothermal heat collector, a disk-type optothermal heat collector, or a tower-type optothermal heat collector; and is specifically applied to a direct steam generation system, a heat transfer oil system and a melt salt system; can also be applied to the boiler heating field or the input and output application field of heat of a heat storage system, and well solves the technical problems which are difficult to solve by means of various normal techniques in the corresponding application field.

Description

technical field [0001] The invention relates to a heat capacity heat exchange device applied in the field of solar heat utilization. Background technique [0002] With the vigorous development of renewable energy such as solar energy in the world, concentrated solar power (CSP) is gradually recognized by people. In the CSP system, the heat absorption and heat transfer part plays a very important role. The heat exchange medium in the solar heat collection system currently mainly uses heat transfer oil as the heat transfer medium. After passing through the heat transfer oil-steam heat exchanger, steam is generated to drive a conventional steam turbine to drive a generator set to generate electricity. Since the current working temperature of heat transfer oil must be controlled within 400°C, exceeding this temperature will lead to problems such as cracking of heat transfer oil, increase in viscosity, and decrease in heat transfer efficiency; Salt materials, such as the molten ...

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Problems solved by technology

Since the current working temperature of heat transfer oil must be controlled within 400°C, exceeding this temperature will lead to problems such as cracking of heat transfer oil, increase in viscosity, and decrease in heat transfer efficiency; Salt materials, such as the molten salt medium heat collector researched by Italy’s ENEA, have a relatively high crystallization point of the molten salt medium, mostly around 230 to 260°C, and there are still many difficulties at present, such as the local temperature may be too high during operation , causing the molten salt to decompose. The molten salt inside the collector needs to be heated and circulated at night to avoid condensation, and the control is extremely complicated. It takes a lot of electricity to maintain the system, which increases the self-consumption of the power plant, so the current molten salt is mainly used for heat storage. can

[0003] The direct steam generation (DSG) technology, which uses water directly as the heat exchange medium, has been tested for many years. This technology is similar to the operating principle of the heating pipe of the steam boiler. Water is used as the working medium, and low-temperature water is injected from one end of the heat-absorbing pipe, and the water flows along the pipe. During the traveling of the road axis, the heat is absorbed gradually and the temperature rises gradually. After reaching the boiling point, it becomes saturated steam, and then continues to absorb heat and becomes superheated steam. The phase transition process is the most complicated. flow pattern, aeroelastic flow pattern, wavy stratified flow pattern, and annular flow pattern; in the wavy stratified process and region, liquid water and saturated gas contact alternately with the pipe wall, resulting in a rapid periodic rise in pipe wall temperature and The decline will have a great impact on the material structure strength of the entire collector, and even damage it; in the annular flow process and area, the upper part of the tube is in direct contact with steam, while the bottom is in direct contact with liquid water, making the process and area The temperature difference between the upper and lower parts of the pipe is large, causing serious warping and shortening the service life of the collector pipe; or when the steam is generated inside the collector, the cloud moves, causing the state of the water to boil in the heating pipe to be unstable. Problems such as phase flow transmission and vaporization pressure in the heat collecting tube are not uniform, such as water hammer, vibration, and fatigue damage of pipeline materials; , serious bending will occur, causing other losses (such as vacuum seal damage); moreover, the existing technology still has not solved the local non-heating of the DSG pipeline (such as local shadows caused by cloud occlusion in the mirror field), which brings a series of Problems, such as water input and steam output flow control, the effect of parameter changes

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