High thermal conductivity light-heat converting compound phase-changeable heat storage material for solar water heater and preparation method thereof

Abstract

The invention discloses a high thermal conductivity light-heat converting compound phase-changeable heat storage material for a solar water heater and a preparation method thereof. The preparation method comprises the following steps: mixing sodium acetate trihydrate with a nucleating agent, heating to 60-80 DEG C and keeping temperature for 1-3h; adding expanded graphite and uniformly stirring, thereby acquiring a uniform sodium acetate trihydrate / expanded graphite mixture; adding a nanometer light-heat converting material while stirring under the temperature of 60-80 DEG C, and continuouslystirring for 2-4h; cooling to room temperature and then pressing the stirred mixed material into a block in density of 0.5-2g / cm<3>, thereby acquiring the high thermal conductivity light-heat converting compound phase-changeable heat storage material. The high thermal conductivity light-heat converting compound phase-changeable heat storage material not only has ideal heat storage density and heatconductivity but also can effectively convert luminous energy into heat energy and has a heat conductivity coefficient of 2.27-3.52W / (m.K) and a light-heat converting rate of 86.6-91.0%.

Description

technical field [0001] The invention relates to the field of phase change heat storage materials, in particular to a high thermal conductivity photo-thermal conversion composite phase change heat storage material for solar water heaters and a preparation method thereof. Background technique [0002] A solar water heater is a device that converts solar energy into heat energy, heating water from low temperature to high temperature, and meeting people's demand for hot water in daily life and production. Solar water heaters currently on the market mainly consist of heat collectors, heat preservation water tanks, control systems, connecting pipes and other parts. The heat generated by the collector is stored in water through heat exchange. However, water has a low heat storage density and generally requires larger tanks to meet demand. Simultaneously, this water heater also has the shortcomings of fouling, the water outlet temperature is not constant, and the water quality of ...

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Problems solved by technology

[0004] However, during the use of sodium acetate trihydrate as a phase change material, it faces three problems: supercooling, poor thermal conductivity, leakage

However, the SiO used in this invention 2 Poor thermal conductivity, the prior art usually uses SiO 2 Used as thermal insulation filler and thermal insulation material, such as Chinese invention patent application 201711167363.4, 200810226164 and 200810042735.5 all involve SiO 2 Used as thermal insulation filler and insulation material

And the thermal conductivity of paraffin is only about 0.25W / (m K). Therefore, the composite phase change material prepared by this invention cannot meet the requirements of phase change materials for high heat transfer rate due to poor thermal conductivity.

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