Heat transfer fluids and corrosion inhibitor formulations for use thereof
View Patent ↗Disclosed herein is a heat transfer fluid concentrate comprising: greater than or equal to 90 weight percent of a freezing point depressant; 16 to 80 ppm of magnesium ions; an azole compound; an inorganic phosphate; a carboxylate; and an acrylate based polymer, wherein the heat transfer fluid concentrate has a pH of 7-9.5 and the weight ratio of acrylate based polymer to magnesium ions is 1 to 25. The heat transfer fluid concentrate can be used to make a heat transfer fluid.
1. A method of preventing corrosion comprising contacting a heat transfer system with a heat transfer fluid comprising:
a) a freezing point depressant, water, or a combination thereof;
b) a carboxylate;
c) an inorganic phosphate;
d) an azole compound;
e) magnesium ions; and
f) an acrylate based polymer;
wherein the heat transfer fluid has a pH of 7 to 9.5; and
wherein a weight ratio of the acrylate based polymer to the magnesium ions is from 1 to 25.
2. The method of claim 1 , wherein the heat transfer system comprises a component made by controlled atmosphere brazing.
3. The method of claim 1 , wherein the heat transfer system comprises aluminum.
4. The method of claim 1 , wherein the heat transfer fluid further comprises lithium ions.
5. The method of claim 1 , wherein the heat transfer fluid further comprises an additional corrosion inhibitor selected from the group consisting of nitrites, molybdates, nitrates, alkali metal nitrates, alkaline earth metal nitrates, salts thereof, and combinations thereof.
6. The method of claim 1 , wherein the heat transfer fluid comprises less than 60 parts per million by weight (ppm) magnesium ions.
7. The method of claim 1 , further comprising calcium ions, wherein the calcium ions are greater than 0.5 ppm.
8. The method of claim 1 , wherein the magnesium ions are about 2 to about 60 ppm.
9. The method of claim 1 , wherein the carboxylate has 6 to 20 carbon atoms.
10. The method of claim 1 , wherein the carboxylate is linear or branched.
11. The method of claim 1 , wherein the carboxylate is selected from the group consisting of 2-ethyl hexanoic acid, hexanoic acid, heptanoic acid, octanoic acid, neodecanoic acid, decanoic acid, nonanoic acid, isoheptanoic acid, dodecanoic acid, sebacic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, dodecanedioic acid, benzoic acid, toluic acid, methylbenzoic acid, tert-butyl benzoic acid, an alkoxy benzoic acid, salicylic acid, phthalic acid, isophthalic acid, terephthalic acid, phenylacetic acid, mandelic acid, 1,2,4-benzenetricarboxylic acid, and combinations thereof.
12. The method of claim 1 , wherein the inorganic phosphate is selected from the group consisting of phosphoric acid, sodium orthophosphate, potassium orthophosphate, sodium pyrophosphate, potassium pyrophosphate, sodium polyphosphate, potassium polyphosphate, sodium hexametaphosphate, potassium hexametaphosphate, and a combination thereof.
13. The method of claim 1 , wherein the azole compound is selected from the group consisting of benzotriazole, tolyltriazole, methyl benzotriazole, butyl benzotriazole, mercaptobenzothiazole, thiazole, a substituted thiazole, imidazole, a substituted imidazole, indazole, a substituted indazole, tetrahydrotolyltriazole, tetrazole, a substituted tetrazole, and a combination thereof.
14. The method of claim 1 , wherein the heat transfer fluid further comprises calcium ions.
15. The method of claim 1 , wherein the weight ratio of acrylate based polymer to magnesium ions is 1 to 15.
16. The method of claim 1 , wherein the magnesium ions are derived from a magnesium compound.
17. The method of claim 16 , wherein the magnesium compound is an inorganic magnesium compound.
18. The method of claim 17 , wherein the inorganic magnesium compound is selected from the group consisting of magnesium nitrate, magnesium sulfate, magnesium molybdate, magnesium tungstate, magnesium vanadate, magnesium perchlorate, magnesium hydroxide, and a combination thereof.
19. The method of claim 16 , wherein the magnesium compound is a magnesium salt.
20. The method of claim 19 , wherein the magnesium salt is selected from the group consisting of magnesium polyacrylate, magnesium polymaleate, magnesium lactate, magnesium citrate, magnesium tartrate, magnesium gluconate, magnesium glucoheptonate, magnesium glycolate, magnesium glucarate, magnesium succinate, magnesium hydroxysuccinate, magnesium adipate, magnesium oxalate, magnesium malonate, magnesium sulfamate, magnesium formate, magnesium acetate, magnesium propionate, magnesium salt of aliphatic tri-carboxylic acid, magnesium salt of aliphatic tetra-carboxylic acid, and combinations thereof.
21. The method of claim 14 , wherein the calcium ions are derived from a calcium compound.
22. The method of claim 21 , wherein the calcium compound is an inorganic compound.
23. The method of claim 22 , wherein the inorganic calcium compound is selected from the group consisting of calcium nitrate, calcium chloride, calcium perchlorate, calcium molybdate, calcium tungstate, calcium vanadate, calcium hydroxide, and a combination thereof.
24. The method of claim 22 , wherein the calcium compound is a calcium salt.
25. The method of claim 24 , wherein the calcium salt is selected from the group consisting of calcium polyacrylate, calcium polymaleate, calcium lactate, calcium citrate, calcium tartrate, calcium gluconate, calcium glucoheptonate, calcium glycolate, calcium glucarate, calcium succinate, calcium hydroxysuccinate, calcium adipate, calcium oxalate, calcium malonate, calcium sulfamate, calcium formate, calcium acetate, calcium propionate, calcium salt of aliphatic tri-carboxylic acid, calcium salt of aliphatic tetra-carboxylic acid, and combinations thereof.
26. The method of claim 4 , wherein the lithium ions are derived from a lithium compound.
27. The method of claim 26 , wherein the lithium compound is an inorganic lithium compound.
28. The method of claim 27 , wherein the inorganic lithium compound is selected from the group consisting of lithium nitrate, lithium perchlorate, lithium molybdate, lithium tungstate, lithium vanadate, lithium hydroxide, lithium phosphate, lithium borate, lithium sulfate, lithium carbonate, and a combination thereof.
29. The method of claim 26 , wherein the lithium compound is a lithium salt.
30. The method of claim 29 , wherein the lithium salt is selected from the group consisting of lithium acetate, lithium benzoate, lithium polyacrylate, lithium polymaleate, lithium lactate, lithium citrate, lithium tartrate, lithium gluconate, lithium glucoheptonate, lithium glycolate, lithium glucarate, lithium succinate, lithium hydroxyl succinate, lithium adipate, lithium oxalate, lithium malonate, lithium sulfamate, lithium formate, lithium propionate, and combinations thereof.
31. The method of claim 1 , wherein the heat transfer fluid further comprises a phosphonocarboxylate or a phosphinocarboxylate.
32. The method of claim 1 , wherein the heat transfer fluid further comprises an antifoaming agent, dispersant, scale inhibitor, surfactant, or colorant.
33. The method of claim 32 , wherein the antifoaming agent comprises a polydimethylsiloxane emulsion antifoaming agent, an ethylene oxide, a propylene oxide, an ethylene oxide-propylene oxide block copolymer, a propylene oxide-ethylene oxide-propylene oxide block copolymer, a fatty acid, a fatty acid ester, a fatty alcohol, an alkoxylated alcohol, a polyglycol, a polyether polyol acetate, a polyether ethoxylated sorbital hexaoleate, a poly(ethylene oxide-propylene oxide)monoallyl ether acetate, a wax, a naphtha, kerosene, an aromatic oil, a silicone product, and a combination thereof.
34. The method of claim 32 , wherein the surfactant is selected from the group consisting of sorbitan fatty acid esters, polyalkylene glycols, polyalkylene glycol esters, copolymers of ethylene oxide (EO) and propylene oxide (PO), polyoxyalkylene derivatives of a sorbitan fatty acid ester, and mixtures thereof.
35. The method of claim 1 , wherein the heat transfer fluid comprises 1 wt % to less than 90 wt % of the freezing point depressant, based on the total weight of the heat transfer fluid.
36. The method of claim 1 , wherein the heat transfer fluid comprises 0.5 wt % to 8 wt % of the carboxylate, based on the total weight of the heat transfer fluid.
37. The method of claim 1 , wherein the heat transfer fluid comprises 0.05 wt % to 0.4 wt % of the inorganic phosphate, based on the total weight of the heat transfer fluid.
38. The method of claim 1 , wherein the heat transfer fluid comprises 0.005 wt % to 2 wt % of the azole compound, based on the total weight of the heat transfer fluid.
39. The method of claim 4 , wherein the lithium ions are 20 to 1800 ppm.
40. The method of claim 39 , wherein the lithium ions are 20 to 1200 ppm.
41. The method of claim 39 , wherein the lithium ions are 20 to 900 ppm.
42. The method of claim 39 , wherein the lithium ions are 30 to 1800 ppm.
43. The method of claim 42 , wherein the lithium ions are 65 to 1800 ppm.
44. The method of claim 1 , wherein the freezing point depressant is ethylene glycol; propylene glycol; 1,3-propanediol; glycerin; or combinations thereof.
45. A method of preventing corrosion comprising contacting a heat transfer system with a heat transfer fluid comprising:
a) ethylene glycol;
b) water;
c) a carboxylate;
d) an inorganic phosphate;
e) an azole compound;
f) calcium ions;
g) magnesium ions; and
h) an acrylate based polymer;
wherein the heat transfer fluid has a pH of 7 to 9.5; and
wherein the weight ratio of acrylate based polymer to magnesium ions is 1 to 15.