Thermal control system for spacecraft

• US 6,230,790 B1
• Filed: 05/10/1999
• Issued: 05/15/2001
• Est. Priority Date: 05/10/1999
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Hicks, Glen W., Hemingway, Michael D., Ritchie, Michael D., Hull, Dwight E. III
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): DUONG, THO V
• Application Number:
  US09/309,004
• Time in Patent Office: 736 Days
• Field of Search: 165/80.4, 165/80.3, 165/273, 165/274, 165/104.33, 361/700, 219/209
• US Class Current: 165/80.4
• CPC Class Codes: B64G 1/50 for temperature control
• CPC Class Codes: B64G 1/506 Heat pipes
• CPC Class Codes: F28D 15/0233 the conduits having a particular shape, e.g. non-circular cross-section, annular F28D15/0241, F28D15/0266 take precedence
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H05K 7/20336 Heat pipes, e.g. wicks or capillary pumps

Abstract

A thermal control system for use in a mobile craft is disclosed. The thermal control system generally includes a structure for supporting one or more heat sources, such as electronic equipment and at least a first heat pipe contained within the structure, the first heat pipe being capable of transferring heat energy from the heat source(s) toward an outboard surface of the structure and/or inhibiting such transfer of heat energy to the outboard surface of the structure, in order to maintain the heat source(s) substantially at room temperatures during operation of such electronics equipment.

Claims

1. A thermal management system comprising:

a honeycomb structure for supporting at least a first heat source, said honeycomb structure having first and second surfaces defining a first thickness of said honeycomb structure, wherein said first heat source is interconnectable to said first surface; and

at least a first heat pipe embedded within said honeycomb structure, said first heat pipe comprising a variable conductance heat pipe having first and second end portions locatable proximate said first and second surfaces of said honeycomb structure, respectively, said variable conductive heat pipe being adapted to transfer heat energy from at least said first heat source supported by said honeycomb structure toward said second surface of said honeycomb structure in a first mode of operation, and to inhibit the transfer of heat energy from said first heat source supported by said honeycomb structure to said second surface of said honeycomb structure in a second mode of operation, wherein said first and said second end portions are non-coplanar, such that said first end portion is vertically offset relative to said second end portion, said first and second end portions being embedded with said honeycomb structure, wherein an intermediate portion extending between said first and second end portions is embedded within said honeycomb structure.

2. A thermal management system as claimed in claim 1, wherein said intermediate portion is orientable between about 1 degree and about 180 degrees relative to at least one of the first and second end portions.

3. A thermal management system as claimed in claim 1, wherein said first heat pipe has a first diameter and includes at least a first bend portion between an intermediate portion and one of said first and second end portions of said first heat pipe, said first bend portion having a radius of at least about 10 times said first diameter.

4. A thermal management system as claimed in claim 1, wherein said variable conductance heat pipe includes a reservoir having a non-condensable gas contained therein, said reservoir being in fluid connection with said second end portion.

5. A thermal management system as claimed in claim 1, wherein said variable conductance heat pipe includes a reservoir containing a non-condensable gas, and a reservoir heater for supplying heat energy to said reservoir, said system further comprising:

at least a first sensor for sensing the temperature of at least said variable conductance heat pipe, said first sensor being electrically interconnectable to said reservoir heater.

6. A thermal management system as claimed in claim 5, wherein said first temperature sensor comprises one of a first thermostat and a first thermistor, said first temperature sensor being adapted to supply power to said reservoir heater.

7. A thermal management system as claimed in claim 5, wherein said first temperature sensor includes one of a first thermostat and a thermistor for activating said reservoir heater during a second mode of operation corresponding to inhibiting transfer of heat energy from said first heat source to said second surface of said honeycomb structure via at least said variable conductance heat pipe.

8. A thermal management system as claimed in claim 5, wherein said first temperature sensor is adapted to activate said reservoir heater to inhibit the transfer of heat energy from at least said first heat source in a third mode of operation.

9. A thermal management system as claimed in claim 8, further comprising at least a first supplemental heater thermally couplable to a second heat pipe comprising a constant conductance heat pipe, wherein said first temperature sensor in electrical interconnection with said first supplemental heater and is adapted to activate said first supplemental heater to transfer heat energy from said first supplemental heater to at least said first heat source in said third mode of operation.

10. A thermal management system as claimed in claim 5, wherein said system is adapted to deactivate said reservoir heater in a first mode of operation to allow the transfer of heat energy from at least said first heat source toward said second surface of said honeycomb structure through said first thickness of said honeycomb structure via at least said variable conductance heat pipe, to activate said reservoir heater in a second mode of operation to inhibit the transfer of heat energy from at least said first heat source to said second surface of said honeycomb structure via at least said variable conductance heat pipe, and to activate said reservoir heater and a first supplemental heater interconnectable to said first surface in a third mode operation to inhibit the transfer of heat energy from at least said first heat source to said second surface of said honeycomb structure via at least said variable conductance heat pipe and to supple heat energy to at least said first heat source.

11. A thermal control system comprising:

a honeycomb structure for at least supporting at least a first heat source, said honeycomb structure having first and second surfaces defining a first thickness of said honeycomb structure, wherein said first heat source is interconnectable to said first surface; and

at least a first variable conductance heat pipe contained within said honeycomb structure for at least one of transferring heat energy from said first heat source supported by said honeycomb structure on said first surface toward said second surface, through said first thickness of said honeycomb structure, and inhibiting the transfer of heat energy from said first heat source on said first surface to said second surface, said first variable conductance heat pipe having first and second end portions locatable within said honeycomb structure, proximate said first and second surfaces of said honeycomb structure, respectively, wherein said first and second end portions are embedded within said honeycomb structure and are non-coplanar, such that said first end portion is vertically offset relative to said second end portion, within said honeycomb structure, wherein an intermediate portion of said first variable conductance heat pipe extending between said first and second end portions is embedded within said honeycomb structure.

12. A thermal control system as claimed in claim 11, wherein said honeycomb structure comprises an insulative member for inhibiting at one of radiative and conductive transfer of heat energy, said honeycomb structure being nonmetallic.

13. A thermal control system as claimed in claim 11, wherein said honeycomb structure comprises at least a first sheet interposable between first and second composite honeycomb cores for limiting at least radiative transfer of heat energy from said first surface towards said second surface of said honeycomb structure.

14. A thermal control system as claimed in claim 13, wherein at least a first portion of cells of at least one of first and second composite honeycomb cores is vented, said honeycomb structure having a heat transfer rate between said first and second surfaces of less than about 3 W/m²°

C.

15. A thermal control system as claimed in claim 11, further comprising:

at least a first constant conductance heat pipe positionable proximate said first surface of said honeycomb structure for at least transferring heat energy from at least one of said first heat source and a second heat source to said first variable conductance heat pipe, said first constant conductance and first variable conductance heat pipes being thermally coupled.

16. A thermal control system as claimed in claim 11, further comprising:

at least a first constant conductance heat pipe positionable proximate said second surface of said honeycomb structure for at least transferring heat energy from said first variable conductance heat pipe, said first constant conductance and first variable conductance heat pipes being thermally coupled.

17. A thermal control system as claimed in claim 11, wherein at least said first variable conductance heat pipe includes a reservoir and a reservoir heater thermally coupled to said reservoir for heating a non-condensible gas contained within said reservoir, said system further comprising:

at least a first sensor adapted to at least monitor the temperature of at least one of said first heat source and said first surface of said honeycomb structure and activate said reservoir heater to inhibit the transfer of heat energy from said first surface to said second surface of said honeycomb structure via said first variable conductance heat pipe.

18. A thermal control system as claimed in claim 17, further comprising:

at least a first supplemental heater adapted to supply heat energy to at least the first heat source, wherein said first supplemental heater is activatable by said first sensor.

19. A thermal control system as claimed in claim 18, wherein said first supplemental heater is interconnectable to one of said first surface of said honeycomb structure and said first heat source, said system further comprising:

at least a first constant conductance heat pipe extending at least between said first supplemental heater and said first heat source, for at least transferring heat energy from said first supplemental heater to said first heat source.

20. A method for controlling the temperature of at least a first heat source interconnectable to a first surface of a honeycomb structure of a spacecraft, said method comprising the steps of:

monitoring the temperature of at least the first heat source; and

performing at least one of first and second steps in first and second modes of operation, respectively, wherein said first step includes the step of transferring heat energy away from the first heat source via a first variable conductance heat pipe embedded within the honeycomb structure, the first variable conductance heat pipe having first and second end portions and an intermediate portion extending therebetween embedded within said honeycomb structure, the first and second end portions being locatable proximate the first surface and the second surface of the honeycomb structure, respectively, wherein the first end portion is vertically offset relative to the second end portion within the honeycomb structure, the first heat source being at a temperature greater than a first temperature, wherein said second step includes the step of inhibiting the transfer of heat energy from the first heat source to the second surface of the honeycomb structure, the first heat source being at a temperature less than a second temperature, the second temperature being less than or equal to the first temperature.

21. A method as claimed in claim 20, wherein said monitoring step comprises the step of:

sensing the temperature of at least the first variable conductance heat pipe embedded in the honeycomb structure, wherein the first variable conductance heat pipe is thermally coupled to at least the first heat source.

22. A method as claimed in claim 20, wherein said inhibiting step in said second mode of operation comprises the step of applying heat to a first reservoir of the first variable conductance heat pipe embedded in the honeycomb structure to maintain the temperature of at least the first heat source within a first temperature range.

23. A method as claimed in claim 20, wherein said inhibiting step in said second mode of operation comprises the step of activating at least a first reservoir heater thermally coupled to a first reservoir of the first variable conductance heat pipe embedded in the honeycomb structure.

24. A method as claimed in claim 20, wherein said inhibiting step in said second mode of operation comprises the step of activating at least a first reservoir heater associated with the first variable conductance heat pipe embedded in the honeycomb structure to maintain the temperature of at least the first heat source within a first temperature range.

25. A method as claimed in claim 20, further comprising the step of:

performing a third step in a third mode of operation, said third step comprising the step of transferring heat energy to at least the first heat source, the first heat source having a third temperature below or equal to the second temperature.

26. A method as claimed in claim 25, wherein said transferring heat energy to at least the first heat source step comprises the step of activating of at least one of a first reservoir heater associated with the first variable conductance heat pipe embedded in the honeycomb structure and at least a first supplemental heater interconnected to the honeycomb structure to raise the temperature of at least the first heat source.

27. A thermal control system comprising:

a structure for at least supporting at least a first heat source, said structure having first and second surfaces defining a first thickness of said structure, wherein said first heat source is interconnectable to said first surface, wherein said structure comprises at least a first sheet interposable between first and second composite honeycomb cores for limiting at least radiative transfer of heat energy from said first surface to second surface of said structure; and

at least a first variable conductance heat pipe contained within the structure for at least one of transferring heat energy from said first surface toward said second surface and inhibiting the transfer of heat energy from said first surface to said second surface, said first variable conductance heat pipe having first and second end portions locatable proximate said first and second surfaces of said structure, respectively, wherein said first and second end portions are non-coplanar.

28. A thermal control system as claimed in claim 27, wherein at least a first portion of cells of at least one of first and second composite honeycomb cores is vented, said structure having a heat transfer rate between said first and second surfaces of less than about 3 W/m²°

C.

29. A thermal control system comprising:

a structure for supporting at least a first heat source, said structure having first and second surfaces defining a first thickness of said structure, wherein said first heat source is interconnectable to said first surface;

at least a first variable conductance heat pipe contained within said structure for at least one of transferring heat energy from said first surface toward said second surface and inhibiting the transfer of heat energy of said first surface to said second surface, said first variable conductance heat pipe having first and second end portions locatable proximate said first and second surfaces of said structure, respectively, wherein first and second end portions are non-coplanar; and

at least a first constant conductance heat pipe positionable proximate said first surface of said structure for at least transferring heat energy from at least one of said first heat source and second heat source to said first variable conductance heat pipe, said first constant conductance heat pipe and said first variable conductance heat pipe being thermally coupled.

30. A thermal control system, comprising:

a structure for at least supporting at least a first heat source, said structure having first and second surfaces defining a first thickness of said structure, wherein said first heat source is interconnectable to said first surface;

at least a first variable conductance heat pipe contained within said structure for at least one of transferring heat energy from said first surface toward said second surface and inhibiting the transfer of heat energy from said first surface to said second surface, said first variable conductance heat pipe having first and second end portions locatable proximate said first and second surfaces of said structure, respectively, wherein said first and second end portions are non-coplanar; and

at least a first constant conductance heat pipe positionable proximate said second surface of said structure for at least transferring heat energy from said first variable conductance heat pipe, said first conductance heat pipe and said first variable conductance heat pipe being thermally coupled.

31. A thermal control system, comprising:

a structure for at least supporting at least a first heat source, said structure having first and second surfaces defining first thickness of said structure, wherein said first heat source is interconnectable to said first surface;

at least a first variable conductance heat pipe contained within said structure for at least one of transferring heat energy from said first surface toward said second surface and inhibiting the transfer of heat energy from said first surface to said second surface, said first variable conductance heat pipe having first and second end portions locatable proximate said first and second surfaces of said structure, respectively, wherein said first and second end portions are non-coplanar, wherein at least said first conductance heat pipe includes a reservoir and a reservoir heater thermally coupled to said reservoir for heating a non-condensable gas contained within said reservoir;

at least a first sensor adapted to at least monitor the temperature of at least one of said first heat source and said first surface of said structure and activate said reservoir heater to inhibit the transfer of heat energy from said first surface to said second surface of said structure via said first variable conductance heat pipe;

at least a first supplemental heater adapted to supply heat energy to at least said first heat source, wherein said first supplemental heat source is activatable by first sensor, wherein said first supplemental heater is interconnectable to one of said first surface of said structure and first heat source; and

at least a first constant conductance heat pipe extending at least between said first supplemental heater and said first heat source, for at least transferring heat energy from said first supplemental heater to said first heat source.