用于高温蓄热介质的二氧化硅纳米颗粒/三元碳酸盐复合熔盐纳米流体的制备方法对比

doi:10.11896/j.issn.1005-023X.2018.23.006

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Abstract Molten salt is a highly efficient heat storage medium, and its heat storage capacity strongly depends on its specific heat capacity, which can be improved effectively by adding nanoparticles. In this paper, silica nanoparticles were dispersed in a ternary carbonate salt (K₂CO₃, Li₂CO₃, Na₂CO₃) solution with the assistance of ultrasonic oscillation, and three different crystallization methods, i.e. direct crystallization, stirring crystallization and dropwise crystallization, were used separately to prepare the silica nano-particles/ternary carbonate composite molten salt nanofluids. We then comparatively studied the thermophysical properties of the resultant nanofluids to obtain the optimum crystallization methodology, and moreover, to explore the specific heat capacity enhancement mechanism. In the experiment, we used differential scanning calorimeter, thermal analyzer and scanning electron microscope to measure or characterize specific heat capacity, decomposition temperature and microscopic surface structure of the samples. Our research confirmed that the dropwise crystallization is the best way to obtain silica nanoparticles/ternary carbonate composite molten salt nanofluid under ultrasonic oscillation. From 450 ℃ to 470 ℃, the composite molten salt nanofluid prepared by dropwise crystallization method exhibits a specific heat capacity 40.59%—44.88% higher than that of the ternary carbonate, and a decomposition temperature of 806.90 ℃, demonstrating a satisfactory heat storage performance. Silica nanoparticles induces the molten salt to generate a rod-like nanostructure, which can obviously increase specific surface area, and in consequence, dramatically raise the specific heat capacity of the molten salt nanofluid.

Key words： silica nanoparticles carbonate molten salt nanofluid ultrasonic oscillation direct crystallization stirring crystallization dropwise crystallization specific heat capacity high-temperature heat storage medium

Published: 20 December 2018

CLC number:

TK513

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	Articles by authors
	REN Manfei
	HUANG Guoqiang

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REN Manfei,HUANG Guoqiang. Silica Nanoparticles/Ternary Carbonate Composite Molten Salt Nanofluid Serving as High-temperature Heat Storage Medium: a Comparative Study on the Preparation Methodology[J]. Materials Reports, 2018, 32(23): 4067-4071.

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http://www.mater-rep.com/EN/10.11896/j.issn.1005-023X.2018.23.006 OR http://www.mater-rep.com/EN/Y2018/V32/I23/4067

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