Heat-transfer media having improved thermal stability and based on higher polyglycols
AssigneeClariant International Ltd.
InventorsMarkus Hafner, Achim Stankowiak, Johann Schuster, Stefan Mauerberger
Life of this patent
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Abstract
The present invention relates to heat-transfer concentrates for solar installations, containing a) from 92 to 99% by weight of at least one polyglycol of the formula R—O—(CH2—CH2—O)n—H, in which n is an integer of from 3 to 500 and R is H, a C1- to C4-alkyl group or an aromatic radical having 6 to 12 carbon atoms, b) from 1 to 8% by weight of at least one corrosion inhibitor, with the proviso that its content of ethylene glycol and 1,2-propylene glycol is less than 0.2% by weight.
Claims8
A heat-transfer concentrate containing
- a) from 92 to 99% by weight of a mixture of triethylene glycol and tetraethylene glycol in a mixing ratio of from 3:1 to 1:3,
- b) from 1 to 8% by weight of at least one corrosion inhibitor, with the proviso that said concentrate has less than 0.2% by weight of ethylene glycol and 1,2-propolene glycol.
A method for transporting heat or cold in a thermal solar installation, said method comprising circulating a heat-transfer medium in said thermal solar installation, wherein the heat-transfer medium contains a heat-transfer concentrate and water, said heat-transfer medium consisting of
- a) from 45 to 55% by weight of a mixture of triethylene glycol and tetraethylene glycol in a mixing ratio of from 3:1 to 1:3,
- b) from 1 to 4% by weight of at least one corrosion inhibitor and
- c) from 45 to 55% by weight of water,
- wherein said heat-transfer concentrate has less than 0.2% by weight of ethylene glycol and 1,2-propylene glycol.
Dependencies are inferred from the claim text.