Molten nitrate salt heat transfer and heat accumulation medium and preparation method thereof

Abstract

The invention provides a molten nitrate salt heat transfer and heat accumulation medium. The heat transfer and heat accumulation medium is prepared from potassium nitrate, lithium nitrate and calciumnitrate. The nitrate salt heat transfer and heat accumulation medium disclosed by the invention has a low melting point and can be applied to a solar thermal power generation system; thus, an initialoperation procedure of the system can be simplified, a special heating device for preventing frozen blocking of the molten salt is avoided, safety stability of the whole system is improved, and operation cost of the whole heat transfer and heat accumulation system is simultaneously reduced. A thermal decomposition temperature can reach 588 DEG C or more, so that the highest use temperature of theheat transfer and heat accumulation medium is improved, and the power generating efficiency of the whole system is greatly improved.

Description

technical field [0001] The invention relates to physical heat transfer and energy storage technology, in particular to a low-melting point mixed ternary nitric acid molten salt heat transfer and heat storage medium for medium and high temperature heat transfer and heat storage. Background technique [0002] The problems of global environmental pollution and energy crisis are becoming more and more acute, and renewable energy is getting more and more attention. Solar thermal power generation technology has attracted widespread attention due to its advantages of large scale, low unit cost, and environmental friendliness, and has developed rapidly. Solar thermal power generation is also called CSP (concentrating solar thermal power generation), which uses flat or curved mirrors to gather solar energy, converts it into thermal energy through a heat absorbing device, and then generates power through a thermal conversion process. Due to the intermittent and unstable characteristic...

AI Technical Summary

Problems solved by technology

The name and quality formula of the current commercialized heat transfer and heat storage materials are: Solar salt (60% NaNO 3 +40% KNO 3 ), Hitec (7% NaNO 3 +53% KNO 3 +40%NaNO 2 ), Hitec XL (7% NaNO 3 +45% KNO 3 +48%Ca(NO 3 ) 2 ) and other molten salt systems, their operating temperature ranges are: 220-600°C, 142-535°C, and 120-500°C, which have been successfully applied to Andasol1-3 and Gemasolar commercial power plants in Spain, THEMIS CSP power plants in France and PSA And Themi power station, however, its common disadvantage is that the melting point is relatively too high, and it is easy to solidify during use, which leads to dangers such as blockage of pipes

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