76-degree phase change energy storage material and preparation method thereof

Abstract

The invention discloses a 76-degree phase change energy storage material and a preparation method thereof. The 76-degree phase change energy storage material is prepared from a main body material andaids, wherein the main body material is an eutectic composition formed by mixing high-purity urea with ammonium bromide according to the weight ratio of (9 to 1) to (6 to 4); and the aids contain 1 to4 percent of porous material, 1 to 2 percent of modified cellulose suspending agent, 0.2 to 0.8 percent of special hydrophilic nano-oxide and 5 to 10 percent of expanded graphite. The main body material and the aids form a solid-non-Newtonian Fluid transformed phase change material; the problems of low energy storage density, great environmental influence and attenuated thermal property of a conventional energy storage material are solved; an enthalpy is improved to 295KJ / kg; after the 76-degree phase change energy storage material is configured in a heat exchanger, heat storage density for heating can reach 700MJ / m<3>; meanwhile, thermal stability is improved to 5 percent of thermal decay / 10,000 times; and the 76-degree phase change energy storage material can be used as an energy storage material in a centralized and distributed heating system on a large scale.

Description

technical field [0001] The invention relates to the field of phase change energy storage materials, more specifically a 76-degree phase change energy storage material and a preparation method thereof. Background technique [0002] The development of energy storage technology in the fields of clean energy, distributed renewable energy, and building energy conservation and consumption reduction is inseparable from the research, development and production of related energy storage materials. Recently, for low-temperature phase change energy storage in the temperature range of 60-90°C, there is a lack of an energy storage material with high energy storage density, non-toxicity, no impact on the environment, and relatively low cost. [0003] The currently used inorganic molten salt phase change energy storage materials have the following defects: first, the inorganic phase change energy storage materials have a large degree of supercooling and are prone to phase separation; secon...

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Problems solved by technology

Recently, for low-temperature phase change energy storage in the temperature range of 60-90°C, there is a lack of an energy storage material with high energy storage density, non-toxicity, no impact on the environment, and relatively low cost.

[0003] The currently used inorganic molten salt phase change energy storage materials have the following defects: first, the inorganic phase change energy storage materials have a large degree of supercooling and are prone to phase separation; second, the phase change energy storage materials are easy to condense on the surface of the heat pipe, which affects The heat conduction from the heat pipe to the energy storage tank; the third is that the phase change energy storage material is highly corrosive to the heat conduction pipe, and it needs to add a nucleating agent containing chloride ions, which is easy to corrode the stainless steel material used as the heat pipe; in addition, the phase change energy storage material still exists Easy to leak, there is a certain temperature difference between the phase change temperature and the ideal temperature required for heating, and these problems need to be solved and improved urgently

[0004] Taking barium hydroxide octahydrate energy storage materials in the field of low temperature as an example, according to the relevant literature (DOI: 10.13224 / j.cnki.jasp.2013.09.002; DOI: 10.13700 / j.bh.1001~5965.2013.0385) Research on the corrosion and heat transfer performance of barium hydroxide phase change materials. In the temperature range of 60~80°C, the phase change latent heat of this material can reach 265.7kJ / kg, the energy storage density is high, the material cost is low, and it is easy to obtain. It is economical, but because of its high toxicity and corrosion to heat-exchanging metal structures, the application site and scale are limited. Once a leak occurs, it will cause harm to personnel and the environment

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