COOLING SYSTEM WITH AUTOMATED SEASONAL FREEZE PROTECTION

• US 20140102672A1
• Filed: 10/11/2012
• Published: 04/17/2014
• Est. Priority Date: 10/11/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: CAMPBELL, Levi A., CHU, Richard C., DAVID, Milnes P., ELLSWORTH, Michael J. Jr., IYENGAR, Madhusudan K., SIMONS, Robert E., SINGH, Prabjit, ZHANG, Jing
• Granted Patent: US 9,351,431 B2
• Time in Patent Office: Days
• US Class Current: 165/104.33
• CPC Class Codes: F28F 2265/14 for preventing damage by freezing, e.g. for accommodating volume expansion
• CPC Class Codes: H05K 7/20836 Thermal management, e.g. server temperature control

Abstract

An automated multi-fluid cooling system and method are provided for cooling an electronic component(s). The cooling system includes a coolant loop, a coolant tank, multiple valves, and a controller. The coolant loop is at least partially exposed to outdoor ambient air temperature(s) during normal operation, and the coolant tank includes first and second reservoirs containing first and second fluids, respectively. The first fluid freezes at a lower temperature than the second, the second fluid has superior cooling properties compared with the first, and the two fluids are soluble. The multiple valves are controllable to selectively couple the first or second fluid into the coolant in the coolant loop, wherein the coolant includes at least the second fluid. The controller automatically controls the valves to vary first fluid concentration level in the coolant loop based on historical, current, or anticipated outdoor air ambient temperature(s) for a time of year.

Claims

1. A cooling system comprising:

a coolant loop configured to circulate coolant and facilitate cooling at least one electronic component, wherein at least a portion of the coolant loop is exposed to outdoor ambient air temperature(s) during normal operation;

at least one coolant tank comprising a first reservoir containing at least partially a first fluid and a second reservoir containing at least partially a second fluid, the first fluid freezing at a lower temperature than the second fluid, the second fluid having superior cooling properties compared with the first fluid, and the first fluid and the second fluid being soluble fluids;

multiple valves for selectively coupling in fluid communication the at least one coolant tank to the coolant loop to controllably couple at least one of the first fluid in the first reservoir or the second fluid in the second reservoir into the coolant loop to vary a concentration level of the first fluid in the coolant within the coolant loop, wherein the coolant within the coolant loop comprises at least the second fluid; and

a controller to automatically control the multiple valves and vary the concentration level of the first fluid in the coolant within the coolant loop based on at least one of historical, current, or anticipated outdoor ambient air temperature(s) for a time of year.

2. The cooling system of claim 1, wherein the controller is configured to automatically vary the concentration level of the first fluid in the coolant loop for the time of year by balancing inhibiting freezing of the coolant within the coolant loop with heat transfer capability of the coolant within the coolant loop.

3. The cooling system of claim 1, wherein the controller automatically controls the multiple valves to increase the concentration level of the first fluid in the coolant within the coolant loop by diverting at least a portion of the coolant within the coolant loop into the first reservoir of the at least one coolant tank while directing the first fluid in the first reservoir into the coolant loop.

4. The cooling system of claim 3, wherein the controller further initiates fractional distillation of the coolant within the first reservoir to facilitate separating the first fluid into the first reservoir and the second fluid into the second reservoir, the fractional distillation resulting in boiling of the second fluid in the first reservoir, wherein second fluid vapor rises within the first reservoir, and passes via a vapor passageway between the first reservoir and the second reservoir into the second reservoir, leaving a higher concentration of the first fluid in the first reservoir.

5. The cooling system of claim 4, wherein the second reservoir further comprises a second fluid vapor condenser for condensing the second fluid vapor within the second reservoir.

6. The cooling system of claim 4, wherein the first reservoir further comprises a first fluid vapor condenser for condensing any first coolant vapor within the first reservoir resulting from the fractional distillation of the fluid while allowing the second fluid vapor to pass via the vapor passageway from the first reservoir into the second reservoir, wherein the first fluid vapor condenses at a higher temperature than the second fluid vapor.

7. The cooling system of claim 6, wherein the coolant loop is a primary coolant loop, and wherein the cooling system further comprises a supplemental coolant loop with a liquid-to-air heat exchanger and a pump coupled in fluid communication therewith, the supplemental coolant loop being coupled to the first fluid vapor condenser in the first reservoir and facilitating cooling of the first fluid vapor condenser, and thereby condensing of the first fluid vapor within the first reservoir, wherein a supplemental coolant within the supplemental coolant loop is maintained at a temperature above a temperature at which the second fluid vapor condenses.

8. The cooling system of claim 1, wherein the controller automatically controls the multiple valves to decrease the concentration level of the first fluid in the coolant within the coolant loop by diverting at least a portion of the coolant within the coolant loop into the first reservoir of the at least one coolant tank while directing the second fluid in the second reservoir into the coolant loop.

9. The cooling system of claim 8, wherein the controller further initiates fractional distillation of the coolant within the first reservoir to facilitate separating the first fluid into the first reservoir and the second fluid into the second reservoir, the fractional distillation resulting in boiling of the second fluid in the first reservoir, wherein second fluid vapor rises within the first reservoir, and passes via a vapor passageway between the first reservoir and the second reservoir into the second reservoir, leaving a higher concentration of the first fluid in the first reservoir.

10. The cooling system of claim 9, wherein the second reservoir further comprises a second fluid vapor condenser for condensing the second fluid vapor within the second reservoir.

11. The cooling system of claim 10, wherein the controller controls the multiple valves to also divert a portion of the coolant within the coolant loop through the second fluid vapor condenser to facilitate condensing of the second fluid vapor within the second reservoir.

12. The cooling system of claim 9, wherein the first reservoir further comprises a first fluid vapor condenser for condensing any first fluid vapor within the first reservoir resulting from the fractional distillation of the coolant while allowing the second fluid vapor to pass via the vapor passageway from the first reservoir into the second reservoir, wherein the first fluid vapor condenses at a higher temperature than the second fluid vapor.

13. The cooling system of claim 12, wherein the coolant loop is a primary coolant loop, and wherein the cooling system further comprises a supplemental coolant loop with a liquid-to-air heat exchanger and a pump coupled in fluid communication therewith, the supplemental coolant loop being coupled to the first fluid vapor condenser in the first reservoir and facilitating cooling of the first fluid vapor condenser, and thereby condensing of the first fluid vapor within the first reservoir, wherein a supplemental coolant within the supplemental coolant loop is maintained at a temperature above a temperature at which the second fluid vapor condenses.

14. The cooling system of claim 1, further comprising a first fluid concentration level sensor associated with the coolant loop, wherein the controller automatically closes one or more of the multiple valves to isolate the at least one coolant tank from the coolant loop upon reaching a desired concentration level of the first fluid within the coolant in the coolant loop for the time of year.

15. A cooled electronic system comprising:

at least one electronic component; and

a cooling system facilitating cooling of the at least one electronic component, the cooling system comprising;

a coolant loop comprising a coolant, wherein at least a portion of the coolant loop is exposed to outdoor ambient air temperature(s);

at least one coolant tank comprising a first reservoir containing at least partially a first fluid and a second reservoir containing at least partially a second fluid, the first fluid freezing at a lower temperature than the second fluid, the second fluid having superior cooling properties compared with the first fluid, and the first fluid and the second fluid being soluble fluids;

multiple valves for selectively coupling in fluid communication the at least one coolant tank and the coolant loop to controllably couple at least one of the first fluid in the first reservoir or the second fluid in the second reservoir into the coolant loop to vary a concentration level of the first fluid in the coolant within the coolant loop, wherein the coolant within the coolant loop comprises at least the second fluid; and

a controller to automatically control the multiple valves and vary the concentration level of the first fluid in the coolant within the coolant loop based on at least one of historical, current, or anticipated outdoor ambient air temperature(s) for a time of year.

16. The cooled electronic system of claim 15, wherein the controller of the cooling system automatically controls the multiple valves to, for different times of the year:

increase the concentration level of the first fluid in the coolant within the coolant loop by diverting at least a portion of the coolant within the coolant loop into the first reservoir of the at least one coolant tank while directing the first fluid in the first reservoir into the coolant loop;

or

decrease the concentration level of the first fluid in the coolant within the coolant loop by diverting at least a portion of the coolant within the coolant loop into the first reservoir of the at least one coolant tank while directing the second fluid in the second reservoir into the coolant loop.

17. The cooled electronic system of claim 16, wherein the controller further initiates fractional distillation of the coolant within the first reservoir to facilitate separating the first fluid into the first reservoir and the second fluid into the second reservoir, the fractional distillation resulting in boiling of the second fluid in the first reservoir, wherein second fluid vapor rises within the first reservoir, and passes via a vapor passageway between the first reservoir and the second reservoir into the second reservoir, leaving a higher concentration of the first fluid in the first reservoir.

18. The cooled electronic system of claim 17, wherein the second reservoir further comprises a second fluid vapor condenser for condensing the second fluid vapor within the second reservoir.

19. The cooled electronic system of claim 17, wherein the first reservoir further comprises a first fluid vapor condenser for condensing any first fluid vapor within the first reservoir resulting from the fractional distillation of the coolant in the first reservoir, while allowing the second fluid vapor to pass via the vapor passageway from the first reservoir into the second reservoir, wherein the first fluid vapor condenses at a higher temperature than the second fluid vapor.

20. The cooled electronic system of claim 15, wherein the cooling system further comprises a first fluid concentration level sensor associated with the coolant loop, and wherein the controller automatically closes one or more of the multiple valves to isolate the at least one coolant tank from the coolant loop upon reaching a desired concentration level of the first fluid in the coolant within the coolant loop for the time of year, and wherein the controller is configured to vary the concentration level of the first fluid in the coolant within the coolant loop for different times of year by balancing inhibiting freezing of coolant within the coolant loop with heat transfer capability of the coolant within the coolant loop.

21. (canceled)