Mixed molten salt as heat transfer and storage medium low in melting point

Abstract

The invention relates to a formula of a mixed molten salt for medium-high temperature heat transfer and storage, and belongs to the physical heat transfer and energy storage technology in innovative and high technologies. The mixed molten salt comprises components in a ratio as follows: 10wt% of calcium nitrate, 60-70 wt% of potassium nitrate, 10-20 wt% sodium nitrate and 10wt% of sodium nitrite; the melting point of the mixed molten salt is about 130 DEG C, which is reduced by nearly 90 DEG C relative to solar salt and is reduced by about 15 DEG C relative to Hitec salt; and the thermal decomposition temperature thereof reaches above 650 DEG C. Sodium nitrate in the molten salt is changed into lithium nitrate, and the specific component ratio is as follows: 18-20wt% of calcium nitrate, 50-55 wt% of potassium nitrate, 9-10 wt% sodium nitrate and 18-20wt% of sodium lithium nitrate; after the component ratio is changed, the melting point of the mixed molten salt is about 90 DEG C, which is reduced by nearly 130 DEG C relative to the solar salt and is reduced by about 50 DEG C relative to the Hitec salt; and the thermal decomposition temperature thereof reaches above 600 DEG C. 10wt% of sodium carbonate is added continuously, then the melting point is raised to about 110 DEG C, while the decomposition temperature is raised by nearly 20 DEG C.

Description

Technical field:

[0001] The invention relates to a formula of mixed molten salt used for medium-high temperature heat transfer and heat storage, which belongs to the high-tech physical heat transfer and energy storage technology. Background technique:

[0002] Since solar thermal power generation can be combined with low-cost large-scale heat storage technology, it can provide stable high-quality electric energy, overcome the defects of poor power transmission quality caused by the inability to use batteries on a large scale in wind power and photovoltaic power stations, and have a large impact on the grid. It is considered to be one of the most promising power generation methods in renewable energy power generation, and it may become the main energy source in the future.

[0003] At present, in the field of trough solar thermal power generation with mature technology, commercial power stations all use heat transfer oil as the heat transfer medium, which leads to high cost o...

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