Thermal management system

• US 20050061487A1
• Filed: 07/14/2004
• Published: 03/24/2005
• Est. Priority Date: 06/30/2000
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Kroliczek, Edward J., Wolf, David A. Sr., Bugby, David, Yun, James
• Granted Patent: US 7,549,461 B2
• Time in Patent Office: Days
• US Class Current: 165/139
• CPC Class Codes: F25B 23/006 boiling cooling systems
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: F28D 15/043 forming loops, e.g. capillary pumped loops

Abstract

A system includes a primary evaporator facilitating heat transfer by evaporating liquid to obtain vapor. The primary evaporator receives the liquid from a liquid line and outputs the vapor to a vapor line. The primary evaporator also outputs excess liquid received from the liquid line to an excess fluid line. A condensing system receives the vapor from the vapor line, and outputs the liquid and excess liquid to the liquid line. The excess liquid is obtained at least partially from a reservoir. A primary loop includes the condensing system, the primary evaporator, the liquid line, and the vapor line, and provides a heat transfer path. Similarly, a secondary loop includes the condensing system, the primary evaporator, the liquid line, the vapor line, and the excess fluid line. The secondary loop provides a venting path for removing undesired vapor within the liquid or excess liquid from the primary evaporator.

Claims

1. A system comprising:

a primary evaporator operable to facilitate heat transfer by evaporating received liquid to obtain vapor, the primary evaporator including a first port for receiving the liquid from a liquid line, a second port for outputting the vapor to a vapor line, and a third port for outputting excess liquid received from the liquid line to an excess fluid line;

a condensing system operable to receive the vapor from the vapor line, to condense at least some of the vapor, and to output the liquid to the liquid line;

a reservoir in fluid communication with the condensing system, wherein the liquid is obtained at least partially from the reservoir;

a primary loop including the condensing system, the primary evaporator, the liquid line, and the vapor line, the primary loop being operable to provide a heat transfer path; and

a secondary loop including the condensing system, the primary evaporator, the liquid line, the vapor line, and the excess fluid line, the secondary loop being operable to provide a venting path for removing other vapor that is present within the liquid from the primary evaporator.

2. The system of claim 1 wherein the liquid in the primary evaporator and received from the liquid line includes the excess liquid in excess of a liquid amount necessary to maintain saturation of a primary wick within a core of the primary evaporator.

3. The system of claim 2 wherein the primary evaporator includes a secondary wick that is operable to perform phase separation of the other vapor from the liquid for output through the excess fluid line.

4. The system of claim 3 wherein the primary wick and the secondary wick of the primary evaporator maintain capillary pumping of the liquid, the excess liquid, and the vapor, so as to maintain flow control to and through the primary evaporator.

5. The system of claim 1 further comprising a mechanical pump that is operable to facilitate the heat transfer by actively pumping the liquid for evaporation by the primary evaporator, and for output as the excess liquid through the third port to the excess fluid line.

6. The system of claim 5 wherein the reservoir is positioned between an output of the condensing system and an input of the mechanical pump.

7. The system of claim 5 wherein the mechanical pump is positioned between an input of the condensing system and an output of the primary evaporator.

8. The system of claim 5 further comprising a bypass valve in parallel with the mechanical pump and operable to bypass the mechanical pump during a passive pumping operation of liquid for evaporation by the primary evaporator.

9. The system of claim 5 wherein the mechanical pump includes a liquid pump that is oriented in series with the liquid line and positioned between the condensing system and the primary evaporator.

10. The system of claim 5 wherein the mechanical pump includes a vapor compressor that is oriented in series with the vapor line and positioned between the primary evaporator and the condensing system.

11. The system of claim 5 further comprising:

a sensor that is operable to communicate a saturation level of a wick of the primary evaporator to the mechanical pump,

wherein a pumping pressure delivered by the mechanical pump is adjusted, based on the saturation level, so as to maintain saturation of the wick with the liquid.

12. The system of claim 5 further comprising a liquid bypass valve connected between the liquid line and the vapor line and operable to maintain constant pump speed operations of the mechanical pump.

13. The system of claim 5 wherein the primary evaporator includes a primary wick and a secondary wick, compositions of which comprise metal.

14. The system of claim 1 further comprising a priming system within the secondary loop, the priming system comprising:

a secondary evaporator coupled to the vapor line; and

a secondary reservoir in fluid communication with the secondary evaporator and coupled to the primary evaporator by the excess fluid line,

wherein the priming system is operable to provide the liquid to the primary evaporator at least partially from the secondary reservoir.

15. The system of claim 14 wherein the condensing system comprises:

a first condenser within the primary loop and coupled to the liquid line and to the vapor line; and

a second condenser within the secondary loop and coupled to the excess fluid line and to the secondary reservoir.

16. The system of claim 1 wherein the third port of the primary evaporator is primarily used to output the excess liquid to the excess fluid line, and wherein the third port comprises a subport for outputting the other vapor to a vapor line, such that the vapor line is included within the secondary loop.

17. The system of claim 1 wherein the liquid line is coaxial to and contained within the excess fluid line.

18. The system of claim 1 further comprising a second primary evaporator that is connected in parallel with the primary evaporator within the primary loop.

19. The system of claim 18 further comprising a back pressure regulator that is oriented in series with the vapor line and positioned between the primary evaporator and the condensing system, and that is operable to substantially equalize heat load between the primary evaporator and the secondary primary evaporator.

20. The system of claim 19 wherein the back pressure regulator restricts vapor from reaching the condensing system until a vapor space of the primary evaporator and of the second primary evaporator is substantially devoid of liquid.

21. The system of claim 1 further comprising a second primary evaporator that is oriented in series with the primary evaporator within the primary loop.

22. The system of claim 1 wherein the condensing system comprises a plurality of condensers connected in parallel to one another.

23. The system of claim 22 comprising:

liquid outputs associated with each of the plurality of condensers and operable to output the liquid to the primary evaporator; and

condenser regulators coupled to the liquid outputs and operable to regulate liquid flow therefrom.

24. The system of claim 1 further comprising:

a second primary evaporator that is connected with the primary evaporator within the primary loop; and

a thermal storage unit coupled to the second primary evaporator.

25. The system of claim 1 further comprising:

a second primary evaporator that is connected with the primary evaporator within the primary loop; and

first and second flow controllers connected to the primary evaporator and the second primary evaporator, respectively, and operable to regulate liquid flow to the primary evaporator and the second primary evaporator, respectively, so as to ensure a substantially equal heat load distribution between the evaporators.

26. The system of claim 1 further comprising:

a second primary evaporator that is connected with the primary evaporator within the primary loop; and

a condensing heat exchanger coupled to the second primary evaporator.

27. The system of claim 26 comprising a spray-cooled evaporator coupled to the condensing heat exchanger by way of a mechanical pump.

28. The system of claim 1 wherein the condensing system comprises a body-mounted radiator.

29. The system of claim 1 wherein the condensing system comprises a deployable or steerable radiator.

30. A method comprising:

evaporating liquid from a primary wick of a primary evaporator to thereby obtain vapor;

outputting the vapor through a vapor line coupled to the primary evaporator;

condensing the vapor from the vapor line within a condensing system;

returning the liquid to the primary evaporator through a liquid line coupled to the primary evaporator, wherein a saturation amount of the liquid is provided so as to maintain a saturation of the primary wick during the evaporating;

providing excess liquid beyond the saturation amount to the primary evaporator at least partially from a reservoir, through the liquid line; and

sweeping the excess liquid and other vapor within the primary evaporator to the condensing system.

31. The method of claim 30 wherein evaporating liquid from the primary wick of the primary evaporator comprises maintaining capillary pumping of the liquid, the excess liquid, and the vapor, so as to maintain flow control to and through the primary evaporator.

32. The method of claim 30 wherein:

outputting the vapor comprises outputting the vapor through a first port of the primary evaporator;

returning the liquid and providing excess liquid comprises returning the liquid and excess liquid through a second port of the primary evaporator; and

sweeping the excess liquid and undesired vapor comprises sweeping the excess liquid and undesired vapor from a third port of the primary evaporator.

33. The method of claim 30 wherein:

outputting the vapor comprises outputting the vapor through a first port of the primary evaporator;

returning the liquid and providing excess liquid comprises returning the liquid and excess liquid through a second port of the primary evaporator; and

sweeping the excess liquid and other vapor comprises sweeping the excess liquid from a third port of the primary evaporator, and sweeping the other vapor from a fourth port of the primary evaporator.

34. The method of claim 30 wherein sweeping the excess liquid and other vapor includes separating the liquid and excess liquid from the other vapor with a secondary wick of the primary evaporator.

35. The method of claim 30 wherein providing excess liquid comprises pumping the excess liquid from the reservoir using a mechanical pump.

36. The method of claim 35 comprising bypassing the mechanical pump using a bypass valve in parallel with the mechanical pump during a passive pumping operation of the liquid for evaporation by the primary evaporator.

37. The method of claim 35 wherein pumping the excess liquid comprises pumping the liquid and the excess liquid using a liquid pump that is oriented in series with the liquid line and positioned between the condensing system and the primary evaporator.

38. The method of claim 35 wherein pumping the excess liquid comprises pumping the vapor to the condensing system using a vapor compressor that is oriented in series with the vapor line and positioned between the primary evaporator and the condensing system.

39. The method of claim 30 wherein providing excess liquid comprises providing the excess liquid from a priming system in which the reservoir is in fluid communication with a secondary evaporator, where the reservoir is coupled to the primary evaporator.

40. The method of claim 39 wherein:

condensing the vapor comprises condensing the vapor within a first condenser of the condensing system, the first condenser being coupled to the liquid line and to the vapor line; and

sweeping the excess liquid and undesired vapor comprises condensing undesired vapor within a second condenser of the condensing system, the second condenser being coupled to a mixed fluid line and to the reservoir.

41. A system comprising:

a heat transfer system including;

a main evaporator having a core, a primary wick, a secondary wick, a first port, a second port, and a third port, and

a condenser coupled to the main evaporator by a liquid line and a vapor line,

wherein a heat transfer system loop is defined by the condenser, the liquid line, the vapor line, the first port, and the second port, and

a venting system configured to remove vapor bubbles from the core of the main evaporator, the venting system including;

a pumping system operable to provide excess liquid to the main evaporator beyond a saturation amount of liquid needed for saturating the primary wick, and

a reservoir in fluid communication with the pumping system and providing the excess liquid,

wherein the vapor bubbles are vented from the core of the main evaporator through the third port, and a venting loop is defined by the condenser, the liquid line, the vapor line, the first port of the main evaporator, and the third port of the main evaporator.

42. The system of claim 41 wherein the pumping system comprises a mechanical pump.

43. The system of claim 42 wherein the primary wick and the secondary wick of the main evaporator maintain capillary pumping of the liquid, the excess liquid, and the vapor, so as to maintain flow control to and through the primary evaporator.

44. The system of claim 41 wherein the pumping system comprises a secondary evaporator in fluid communication with the reservoir and coupled to the vapor line.

45. The system of claim 44 wherein the reservoir is in fluid communication with the secondary wick of the main evaporator through a mixed fluid line coupled to the third port of the main evaporator.

46. The system of claim 41 wherein the excess liquid is substantially removed from the core of the main evaporator through a fourth port of the main evaporator.