Heat transfer system with aqueous heat transfer fluid

Patent metadata

Field	Value
Publication number	US-9260644-B2
Application number	US-201313855378-A
Country	US
Kind code	B2
Filing date	Apr 2, 2013
Priority date	Apr 2, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

According to one aspect of the invention, a heat transfer system comprises a heat transfer fluid circulation loop. The heat transfer system includes a heat exchanger disposed in the heat transfer fluid circulation loop. The heat transfer fluid is an aqueous solution having a pH of 7.8 to 8.0 that comprises from 1.00 wt. % to 1.20 wt. % of a buffer composition comprising sodium and/or potassium salts of borate, carbonate, sodium bicarbonate, from 0.40 wt. % to 0.60 wt. % of a straight chain aliphatic dicarboxylic acid, from 0.90 wt. % to 1.10 wt. % of a branched aliphatic carboxylic acid, from 0.40 wt. % to 0.60 wt. % of an aromatic carboxylic acid, from 0.04 wt. % to 0.08 wt. % of a molybdate salt, and from 0.01 wt. % to 0.03 wt. % of an aldehyde biocide, based on the total weight of the heat transfer fluid.

First claim

The invention claimed is:

1. A heat transfer system comprising a heat exchanger disposed in a heat transfer fluid circulation loop, wherein the heat transfer fluid is an aqueous solution having a pH of 7.8 to 8.0 that comprises:
1.00 wt. % to 1.20 wt. % of a buffer composition comprising sodium and/or potassium salts of borate, carbonate, and bicarbonate;
0.40 wt. % to 0.60 wt. % of a straight chain aliphatic dicarboxylic acid;
0.90 wt. % to 1.10 wt. % of a branched aliphatic carboxylic acid;
0.40 wt. % to 0.60 wt. % of an aromatic carboxylic acid;
0.04 wt. % to 0.08 wt. % of a molybdate salt; and
0.01 wt. % to 0.03 wt. % of an aldehyde biocide;
each weight percentage based on the total weight of the heat transfer fluid.

2. The heat transfer system of claim 1 , wherein the heat transfer system includes a surface comprising aluminum in contact with the heat transfer fluid.

3. The heat transfer system of claim 2 , wherein the surface comprising aluminum is a component of a heat exchanger, a cold plate, or a fluid conduit.

4. The heat transfer system of claim 2 , comprising a plurality of heat exchangers including a surface comprising aluminum in contact with the heat transfer fluid.

5. The heat transfer system of claim 2 , having a ratio of aluminum surface are to heat transfer fluid volume of at least 1.0 cm 2 /ml.

6. The heat transfer system of claim 1 , wherein the buffer composition comprises sodium borate, sodium carbonate, and sodium bicarbonate.

7. The heat transfer system of claim 5 , wherein the buffer composition comprises from 0.10 wt. % to 0.40 wt. % of sodium borate, from 0.10 wt. % to 0.40 wt. % of sodium carbonate, and from 0.40 wt. % to 0.80 wt. % of sodium bicarbonate, based on the total weight of the heat transfer fluid.

8. The heat transfer system of claim 1 , wherein the straight chain aliphatic dicarboxylic acid is a C 8 -C 12 dicarboxylic acid, the branched aliphatic carboxylic acid is a C 4 -C 12 monocarboxylic acid having at least one branch therein, and the aromatic carboxylic acid is benzoic acid.

9. The heat transfer system of claim 7 , wherein the straight chain aliphatic dicarboxylic acid is sebacic acid and the branched aliphatic carboxylic acid is 2-ethylhexanoic acid.

10. The heat transfer system of claim 1 , wherein the aldehyde biocide is ortho-phthaldehyde or glutaraldehyde.

11. The heat transfer system of claim 9 , wherein the aldehyde is orthophthaldehyde.

12. The heat transfer system of claim 1 , wherein the molybdate salt is sodium molybdate.

13. The heat transfer system of claim 1 , wherein the heat transfer fluid comprises from 1.09 wt. % to 1.12 wt. % of the buffer composition, from 0.45 wt. % to 0.55 wt. % of the straight chain aliphatic dicarboxylic acid, from 0.95 wt. % to 1.05 wt. % of the branched aliphatic carboxylic acid, from 0.45 wt. % to 1.05 wt. % of benzoic acid as the aromatic carboxylic acid, from 0.055 wt. % to 0.065 wt. % of the molybdate salt, and from 0.015 wt. % to 0.025 wt. % of the aldehyde biocide, based on the total weight of the heat transfer fluid.

14. The heat transfer system of claim 1 , wherein the buffer composition comprises sodium borate, sodium carbonate, and sodium bicarbonate, the straight chain aliphatic dicarboxylic acid is sebacic acid, the branched aliphatic carboxylic acid is 2-ethylhexanoic acid, the aromatic carboxylic acid is benzoic acid, the molybdate salt is sodium molybdate, and the aldehyde biocide is ortho-phthaldehyde.

15. A method of operating a heat transfer system comprising circulating a heat transfer fluid through a heat exchanger disposed in a heat transfer fluid circulation loop, wherein the heat transfer fluid is an aqueous solution having a pH of 7.8 to 8.0 that comprises:
1.00 wt. % to 1.20 wt. % of a buffer composition comprising sodium and/or potassium salts of borate, carbonate, and bicarbonate;
0.40 wt. % to 0.60 wt. % of a straight chain aliphatic dicarboxylic acid;
0.90 wt. % to 1.10 wt. % of a branched aliphatic carboxylic acid;
0.40 wt. % to 0.60 wt. % of an aromatic carboxylic acid;
0.04 wt. % to 0.08 wt. % of a molybdate salt; and
0.01 wt. % to 0.03 wt. % of an aldehyde biocide;
each weight percentage based on the total weight of the heat transfer fluid.

16. The method of claim 15 , wherein the heat transfer system includes a surface comprising aluminum in contact with the heat transfer fluid.

17. The method of claim 16 , having a ratio of aluminum surface area to heat transfer fluid volume of at least 1.0 cm 2 /ml.

18. The method of claim 15 , wherein a portion of the heat transfer fluid is in a frozen state.

19. A heat transfer fluid, comprising, in an aqueous solution having a pH of 7.8 to 8.0:
1.00 wt. % to 1.20 wt. % of a buffer composition comprising sodium and/or potassium salts of borate, carbonate, and bicarbonate;
0.40 wt. % to 0.60 wt. % of a straight chain aliphatic dicarboxylic acid;
0.90 wt. % to 1.10 wt. % of a branched aliphatic carboxylic acid;
0.40 wt. % to 0.60 wt. % of an aromatic carboxylic acid;
0.04 wt. % to 0.08 wt. % of a molybdate salt; and
0.01 wt. % to 0.03 wt. % of an aldehyde biocide;
each weight percentage based on the total weight of the heat transfer fluid.

20. The heat transfer fluid of claim 19 , wherein the buffer composition comprises sodium borate, sodium carbonate, and sodium bicarbonate, the straight chain aliphatic dicarboxylic acid is sebacic acid, the branched aliphatic carboxylic acid is 2-ethylhexanoic acid, the aromatic carboxylic acid is benzoic acid, the molybdate salt is sodium molybdate, and the aldehyde biocide is ortho-phthaldehyde.

Assignees

• Hamilton Sundstrand Space Systems Internat Inc
• Hamilton Sundstrand Space Sys

Inventors

• Steele John W
• Montefusco Daniel
• Peyton Barbara M
• Varsik Jerome D

Classifications

• F28D15/00

  Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls {; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies (F28D17/00, F28D19/00, F28D20/00 take precedence)} · CPC title

• C23F11/08

  in other liquids · CPC title

• C09K5/10 Primary

  Liquid materials · CPC title