Preparation and comparative analysis of thermophysical properties on low melting point mixed nitrate molten salts

doi:10.19799/j.cnki.2095-4239.2020.0023

Abstract

Abstract:

Mixed Nitrates Molten salt as heat transfer and storage medium have been widely applied in commercial solar power plant and thermal energy storage. After more than ten years of independent research and development, our team has successfully obtained LMPS series mixed nitric acid molten salt with low melting point and high decomposition temperature. Firstly, the DSC and TG curves of different mixed nitrates are measured and analyzed in this paper. It is found that the melting point of LMPS II quaternary mixed nitrate salt is the lowest, the decomposition temperature is the highest, and the liquid range was the largest. Secondly, the results of 1200 hours constant high temperature test show that the fluctuation range of melting point is no more than ±4.89% and decomposition temperature of mixed quaternary nitrate salt at low melting point is no more than ±3.54%.The specific heat capacity and thermal conductivity of LMPS II quaternary salt are better than that of LMPS I quaternary salt and LMPS III binary salt. Therefore, in practical engineering applications, the quaternary nitrate salt of LMPS II with low melting point and high decomposition temperature has excellent heat transfer and heat storage performance; it can reduce the operating cost of the system and the risk of freezing.

Key words: thermal energy storage, low melting point, molten salt, mixed nitrate molten salts

CLC Number:

TM 123

ZHANG Cancan, WU Yuting, LU Yuanwei. Preparation and comparative analysis of thermophysical properties on low melting point mixed nitrate molten salts[J]. Energy Storage Science and Technology, 2020, 9(2): 435-439.

Figures/Tables 8

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名称	NaNO₃	KNO₃	NaNO₂	Ca(NO₃)₂	LiNO₃
Solar salt	√	√	—	—	—
Hitec	√	√	√	—	—
Hitec XL	√	√	—	√	—
LMPS I	√	√	—	√	√
LMPS II	√	√	√	√	—
LMPS III	—	√	—	√	—

名称	储热密度/kW·h·t^-1	材料成本 /元·(kW·h) ^-1	系统成本 /元·(kW·h)^-1
Solar salt	110	38	82
Hitec	113	42	85
LMPS I	190	63	88
LMPS II	199	25	49.3
LMPS III	137	29	60

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