Heat transfer fluids and corrosion inhibitor formulations for use thereof

1. A heat transfer fluid comprising

a) a freezing point depressant;

b) 25 to 1600 ppm lithium ions; and

c) a carboxylate;

wherein the heat transfer fluid has a pH of 7 to 9.5 and is free of lithium molybdate, silicate, borate and amines.

2. The heat transfer fluid of claim 1 further comprising less than 60 ppm calcium ions.

3. The heat transfer fluid of claim 1 further comprising less than 40 ppm calcium ions.

4. The heat transfer fluid of claim 1 further comprising magnesium ions.

5. The heat transfer fluid of claim 4 , wherein the magnesium ions are about 2 to about 60 ppm.

6. The heat transfer fluid of claim 1 further comprising 300 to 900 ppm of an acrylate based polymer.

7. The heat transfer fluid of claim 6 , wherein the acrylate based polymer is a water soluble polymer.

8. The heat transfer fluid of claim 6 , wherein the acrylate based polymer comprises a phosphinopolyacrylate.

9. The heat transfer fluid of claim 1 , wherein the carboxylate comprises about 0.5 to about 8 wt % carboxylate, based on the total weight of the heat transfer fluid.

10. The heat transfer fluid of claim 1 , wherein the heat transfer fluid further comprises an inorganic phosphate.

11. The heat transfer fluid of claim 10 , wherein the heat transfer fluid comprises about 0.05 to about 0.4 wt % inorganic phosphate, based on the total weight of the heat transfer fluid.

12. The heat transfer fluid of claim 10 , wherein the inorganic phosphate comprises phosphoric acid, sodium orthophosphate, potassium orthophosphate, sodium pyrophosphate, potassium pyrophosphate, sodium polyphosphate, potassium polyphosphate, sodium hexametaphosphate, potassium hexametphosphate, or a combination thereof.

13. The heat transfer fluid of claim 1 , wherein the heat transfer fluid further comprises an azole compound.

14. The heat transfer fluid of claim 13 , wherein the azole comprises benzotriazole, tolyltriazole, methyl benzotriazole, tetrandryotolyltriazole, butyl benzotriazole, mercaptobenzothiazole, thiazole, imidazole, benzimidazole, a substituted imidazole, indazole, a substituted indazole, tetrazole, a substituted tetrazole, or a combination thereof.

15. The heat transfer fluid of claim 13 , wherein the heat transfer fluid comprises about 0.005 to about 2 wt % azole compound, based on the total weight of the heat transfer fluid.

16. The heat transfer fluid of claim 1 , wherein the freezing point depressant comprises an alcohol or mixture of alcohols.

17. The heat transfer fluid of claim 16 , wherein the alcohol or mixture of alcohols comprises monohydric alcohol, polyhydric alcohol, or mixtures thereof.

18. The heat transfer fluid of claim 16 , wherein the alcohol is selected from the group consisting of methanol; ethanol; propanol; butanol; ethoxylated furfuryl alcohol; ethylene glycol; propylene glycol; 1,3-propanediol; glycerol; diethylene glycol; triethylene glycol; 1,2-propyle glycol; 1,3-propylene glycol; dipropylene glycol; butylene glycol; glycerol-1,2-dimethyl ether; glycerol-1,3-dimethyl ether; monoethylether of glycerol; 1,2,6-hexanetriol; trimethylopropane; methoxyethanol; and a combination thereof.

19. The heat transfer fluid of claim 1 , wherein the heat transfer fluid comprises about 1 to about 90 wt % freezing point depressant, based on the total weight of the heat transfer fluid.

20. The heat transfer fluid of claim 1 , wherein the lithium ions are about 25 to about 1500 ppm.

21. The heat transfer fluid of claim 1 , wherein the lithium ions are about 25 to about 1400 ppm.

22. The heat transfer fluid of claim 1 , wherein the heat transfer fluid further comprises water.