METHOD FOR IMPROVING NITRITE SALT COMPOSITIONS USED AS HEAT TRANSFER MEDIUM OR HEAT STORAGE MEDIUM

摘要

Disclosed is a method for maintaining or extending the long-term operating temperature range of a heat transfer medium and/or heat storage medium containing a nitrite salt composition that contains, as essential components, an alkali metal nitrate or an alkaline earth metal nitrate or a mixture of alkali metal nitrate and alkaline earth metal nitrate, as well as an alkali metal nitrite and/or an alkaline earth metal nitrite. Said method is characterized in that the entire nitrite salt composition or a portion thereof is brought in contact with an additive composed of nitrogen and/or rare gases, each of which contains 0 to 20 vol.% of elemental oxygen relative to the total amount of the additive, in combination with nitrogen oxides and/or nitrogen oxide-generating compounds.