WO2008067434A2

WO2008067434A2 - Methods and apparatus for electronic cooling unit with unique features

Info

Publication number: WO2008067434A2
Application number: PCT/US2007/085876
Authority: WO
Inventors: William G. Wyatt; James A. Prueti; Card Libby
Original assignee: Raytheon Company
Priority date: 2006-11-29
Filing date: 2007-11-29
Publication date: 2008-06-05
Also published as: US20080128112A1; EP2100203A2; WO2008067434A3; EP2100203A4; EP2100203B1

Abstract

An apparatus, system, and method for electronic cooling unit with unique features is disclosed. In representative embodiments and applications, the present invention generally provides improved methods and systems for cooling electronic equipment in environments subject to ingestion of foreign object debris.

Description

/N THE UNITED STA TES PA TENTAND TRADEMARK OFFICE AS RECEIVING OFFICE FOR THE PA TENT COOPERA TION TREA TY (PCT)

METHODS AND APPARATUS FOR ELECTRONIC COOLING UNIT WITH UNIQUE FEATURES

Inventors: William G. Wyatt (Piano, Texas); James A. Pruett (Allen,

Texas); Carl Libby (Allen, Texas)

RELATED APPLICATIONS

[0001 ] This application claims the benefit of United States Provisional Patent Application Serial No. 60/867,732 filed in the United States Patent and Trademark Office on November 29, 2006.

BACKGROUND OF INVENTION

[0002] Various techniques are used to facilitate cooling of mechanical and electronic equipment. The ability to provide sufficient cooling to components that experience heat gain is essential to proper function and product reliability. Common methods of cooling typically include forced movement of ambient air, radiators, heatsinks, and use of cooling liquids. Cooling may be as simple as using a fan to move relatively cooler air over a component that has experienced heating.

[0003] Prior attempts to address this problem have resulted in cooling units that suffer frnm CIOPPIΠP if lnrβe amnnnts of foreign debris are passed through them. An example of this phenomenon is the typical air conditioning unit that employs a fin-tube heat exchanger. Fin spacing on a cooling system may withstand small amounts of sand passing through the fin, but as the mass flow volume of sand increase the system may clog.

[0004] Typical fin-tube heat exchangers can accept water impingement during operation but they cannot operate while submerged. Also, fin-tube heat exchangers tend to suffer damage from small arms fire or shrapnel. Accordingly, there exists a need to address these and other deficiencies associated with conventional techniques.

SUMMARY OF THE INVENTION

[0005] In a representative aspect, the present invention includes a system and method for convection cooling for electronics. The system comprises a fin-tube heat exchanger and/or the like. In accordance with various aspects of the present invention, the system may provide cooling for equipment located adjacent to and/or equipment located away from the cooling unit with a reduced likelihood of clogging due to ingestion of foreign matter such as sand.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Representative elements, operational features, applications and/or advantages of the present invention reside inter aha in the details of construction and operation as more fully hereafter depicted, described or otherwise identified - reference being made to the accompanying drawings, images, figures, etc. forming a part hereof - wherein like numerals refer to like parts throughout. Other elements, operational features, applications and/or advantages will become apparent in view of certain exemplary embodiments recited in the claims.

[0007] Fig.l representatively illustrates an electronic cooling unit in accordance with a representative embodiment of the present invention;

[0008] Fig.2 representatively illustrates a possible installation of an electronic cooling unit in accordance with a representative embodiment of the present invention; and

[0009] Fig.3 representatively illustrates an operational schematic of an electronic cooling unit in accordance with a representative embodiment of the present invention;

[0010] Fig.4 representatively illustrates additional elements that may be incorporated with an electronic cooling unit in accordance with a representative embodiment of the present invention.

[001 1] Elements in the figures, drawings, images, etc. are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Furthermore, the terms 'first', 'second', and the like herein, if any, are used inter alia for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, the terms 'front', 'back', 'top', 'bottom', 'over', 'under', and the like in the disclosure and/or in the claims, are generally employed for descriptive purposes and not necessarily for comprehensively describing exclusive relative position. It will be understood that any of the preceding terms so used may be interchanged under appropriate circumstances such that various embodiments of the invention described herein, for example, are capable of operation in other configurations and/or orientations than those explicitly illustrated or otherwise described.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0012] The following representative descriptions of the present invention generally relate to exemplary embodiments and the inventors' conception of the best mode, and are not intended to limit the applicability or configuration of the invention in any way. Rather, the following description is intended to provide convenient illustrations for implementing various embodiments of the invention. As will become apparent, changes may be made in the function and/or arrangement of any of the elements described in the disclosed exemplary embodiments without departing from the spirit and scope of the invention.

[0013] The present invention may be described herein in terms of conventional fin-tube heat exchangers, environmental control units, and/or air conditioning systems in conjunction with one or more cooling fluids. It should be appreciated that the cooling unit may comprise any number of conventional materials including but not limited to ceramics, metals, plastics, fiberglass, glass, and various other inorganic and/or organic materials. Furthermore, such fins, tubes, and/or ducting may comprise various forms, layers, sizes, thicknesses, textures and dimensions and/or the like.

[0014] The cooling fluid, in accordance with various aspects of the present invention, may comprise any fluid, liquid/vapor or liquid/gas mixture suitable for cooling, stabilizing temperature, and/or the like. In a representative embodiment of the present invention, fluids used in an electronic cooling unit system in accordance with various aspects of the present invention may include R 134a and/or a 50/50 Propylene Glycol/Water solution.

[0015] Referring now to Fig.l , an electronic cooling unit system 100 in accordance with various aspects of the present invention may be implemented in conjunction with a series closed-loop fluid cooling sections and a forced air system such as a heat exchanger and/or a fan. In a representative embodiment of the present invention, the electronic cooling unit 100 comprises a condenser 110, a fan 112, an expansion valve 114, an evaporator 116, a compressor 118, a pump 120, and one or more cooling loops, such as a refrigerant loop 122, and a coolant loop 124. The electronic cooling unit 100 may further comprise additional elements for the application and/or environment, such as fins 126, a mounting plate, a protective covering, and/or an electronics assembly 128.

[0016] The condenser 110 may comprise any system that converts a fluid from a gaseous state to a liquid state and/or may be substantially configured to exchange heat with another medium. For example, in a representative embodiment of the present invention, the condenser 110 may comprise a fin-tube heat exchanger such as a conventional radiator and/or air conditioning unit. The condenser 110 may be set at any orientation in order to have ambient air passed through it. The fins 126 may also be configured in any manner to affect heat transfer.

[0017] Referring now to Fig.2, in a representative embodiment of the present invention, the condenser 110 may be positioned at least one of non-vertically and non- horizontally in relation to gravity and an inlet 210 in order to facilitate the passage of foreign object debris, such as sand, through the electronic cooling unit 100 without clogging. The fins 126 may also be configured with a spacing that reduces the probability of foreign object debris clogging in the fin area of the condenser 110.

[0018] The condenser 110 may further comprise an air duct 212 to facilitate the movement of air flow through the condenser 110. The air duct 212 may be made of any material such as ceramics, metals, plastics, fiberglass, glass, various other inorganic and organic materials and/or the like.

[0019] The condenser 110 may also be configured to transfer heat through multiple mediums. In a representative embodiment of the present invention, the condenser may dissipate heat from the fluid to passing air and to another fluid such as water if the electronic cooling unit 100 was submerged during the crossing of a river.

[0020] The fan 112 may comprise any system that moves air through the electronic cooling unit 100 and over the condenser 110. For example, in a representative embodiment of the present invention, the fan 112 may pull air through the condenser 110 and air duct 212 and/or push air through the condenser 110 and air duct 212. In another representative embodiment of the present invention, the fan 112 may be further configured to pull ambient air in via an inlet 210 in the electronic cooling unit 100, through the fins 126 of the condenser 110, and then move the air down the air duct 212 before exhausting the air through an outlet 216 on the back side of the fan 112.

[0021 ] It should be appreciated that in accordance with various aspects of the present invention the fan 112 may also be adapted to cease operation on the occurrence of a specified event. Specified events may include, for example, extremely cold conditions and/ submersion of the cooling unit in water. Any system may be used to signal the fan 112 to stop operating, such as a moisture sensor, a thermocouple and/or the like. In a representative embodiment of the present invention, the fan may be configured to temporarily deactivate if the electronic cooling unit 100 is submerged allowing the condenser 110 to dissipate heat directly to the surrounding water. Once the electronic cooling unit 100 is no longer submerged, the fan 112 may be reactivated and the condenser 110 may dissipate heat to the ambient air.

[0022] The expansion valve 114, in accordance with various aspects of the present invention, may be configured to convert high pressure fluid into a relatively lower pressure fluid. The expansion valve 114 may be configured in any manner to cause a change in pressure of the fluid, such as through a block type expansion valve and/or an internally equalized expansion valve. In a representative embodiment of the present invention, the expansion valve 114 comprises a thermostatic expansion valve that reduces the pressure of the fluid while regulating the mass flow of the fluid.

[0023] The evaporator 116, in accordance with various aspects of the present invention, may comprise any system that converts a fluid from a liquid state to a gaseous state for the purpose of exchanging heat with another medium. For example, the evaporator 116 may comprise a fin-tube heat exchanger such as a conventional radiator, an air conditioning unit, and/or a coldplate. [0024] Referring now to Fig.3, in a representative embodiment of the present invention, the evaporator 116 may comprise a coldplate with one or more fluid loops flowing through it. For example, the evaporator 116 may comprise a refrigerant loop 122 further comprising the fluid that passes through the condenser 110 and expansion valve 114. The fluid in the refrigerant loop 122 may comprise any fluid, liquid/vapor or liquid/gas mixture suitable for cooling, stabilizing temperature and/or the like. In a representative embodiment of the present invention, the refrigerant may comprise R 134a.

[0025] In a representative embodiment of the present invention, the refrigerant loop 122 may be used to absorb heat from a coolant loop 124 that is used to remove heat from nearby or remote sources. For example, the coolant loop 124 may be used to cool remote sources such as a radar unit. The coolant loop 124 may also be configured to absorb heat from multiple sources by partitioning the fluid among several heat sources through various pipes, tubes, coldwalls, and/or the like. The coolant loop 124 may further be configured to provide heating to nearby or remote sources through the addition or use of a heat source. In a representative embodiment of the present invention, the fluid in the coolant loop may comprise a combination of a water/glycol solution.

[0026] The evaporator 116 may also act as a coldplate for nearby electronic assemblies. For example, referring now to Fig.l, the evaporator may be mounted directly to an electronics assembly and act as a coldplate. The refrigerant loop 122 of the evaporator 116 may be configured to absorb heat from the electronics assembly in addition to the heat transferred by the coolant loop 124. [0027] The compressor 118, in accordance with various aspects of the present invention, converts low pressure fluid into a relatively higher pressure fluid. The compressor 118 may be configured in any manner to cause a change in pressure of the fluid, e.g., a centrifugal, rotary, and/or axial compressor.

[0028] It should be appreciated that the pump 120, in accordance with various aspects of the present invention, converts a low pressure fluid into a relatively higher pressure fluid. The pump 120 may comprise any system that causes an increase in the pressure of a fluid, e.g., a centrifugal, kinetic, or positive displacement pump. Referring now to Fig. 3, in a representative embodiment of the present invention, the pump 120 may be configured to increase the head pressure in the coolant loop 124.

[0029] Referring now to Fig.4, the electronic cooling unit 100 may further comprise a mounting plate 410. The mounting plate 410 may be made of any material such as ceramics, metals, plastics, fiberglass, glass, various other inorganic and organic materials and/or the like. In a representative embodiment of the present invention, the mounting plate 410 may be used to mount the electronic cooling unit 100 and other nearby components such as a projectile tube launcher 412 to a larger system such as a vehicle. In another representative embodiment of the present invention, mounting plate 410 may also perform any appropriate function for the application of the electronic cooling unit 100 such as providing protection from small arms fire and/or shrapnel.

[0030] The electronic cooling unit 100, in accordance with various aspects of the present invention, may additionally comprise a protective cover. The protective cover may be made of any material such as ceramics, metals, plasties, fiberglass, glass, various other inorganic and organic materials and/or the like. In a representative embodiment of the present invention, the protective cover may act to protect the individual elements of the electronic cooling unit 100 from external damage from sources such as small arms fire or shrapnel.

[0031 ] It should further be appreciated that in accordance with various aspects of the present invention the protective cover may comprise an opening to facilitate air movement into and/or out of the electronic cooling unit 100. The opening may be configured in any manner that allows air to pass through the electronic cooling unit 100.

[0032] In a representative embodiment of the present invention, the opening may comprise an opening near the inlet of the condenser 110 and a second opening near the fan 112 outlet. The openings may further comprise a chevron design that allows air movement through the electronic cooling unit 100 while also hindering a direct air path from the outside the protective cover to the internal elements of the electronic cooling unit 100.

[0033] In another representative embodiment of the present invention, the openings may also comprise a series of alternating holes in multiple layers of protective material. For example, the first layer may comprise a one-half inch thick layer of steel with one-half inch holes spaced one inch apart. The second layer may be positioned at a short distance away from the first layer providing an air gap between the two layers and comprise one-half inch thick steel with similar one-half inch holes that are offset from the holes in the first layer of steel such that there is no direct line of sight between the two layers.

[0034] The protective cover may also be configured to be accessible to allow for the inspection, repair, cleaning, or replacement of the electronic cooling unit 100 or its individual elements. For example, the protective cover may be completely removable, hinged at one end, or comprise a removable interlocking piece of protective material.

[0035] The electronic cooling unit 100, in accordance with various aspects of the present invention, may be implemented to remove heat via a coolant loop 124 and exchange heat to a refrigerant loop 122 in the evaporator 116. The heat absorbed by the refrigerant loop 122 may then be mixed with ambient air through a condenser 110. Alternatively and/or conjunctively, the condenser 110 may be configured to operate with a reduced likelihood of clogging from foreign object debris due to its fin 126 spacing and/or its orientation in relation to gravity.

[0036] It should be appreciated that in accordance with various aspects of the present invention an internal fan 112 may be configured to facilitate air movement into the electronic cooling unit 100 and/or through the condenser 110. In a representative embodiment of the present invention, the fan 112 may be deactivated if the electronic cooling unit 100 is at least partially submerged in water, such as when a vehicle is crossing a river. In another representative embodiment of the present invention, the condenser 110 may be adapted to dissipate heat directly to the water while the electronic cooling unit 100 is at least partially submerged. The fan 112 is reactivated once the electronic cooling unit 100 is no longer submerged.

[0037] The electronic cooling unit 100 may include a protective cover capable of protecting internal components from damage resulting from shrapnel and/or small arms fire.

[0038] The electronic cooling unit 100 may be further adapted for use in an airborne application through the removal, reconfiguration, and/or addition of internal elements. For example, the fan 112 may be removed from an airborne application and RAM air used instead to facilitate heat transfer.

[0039] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments. Various modifications and changes may be made, however, without departing from the scope of the present invention as set forth in the claims. The specification and figures are illustrative, rather than restrictive, and modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the claims and their legal equivalents rather than by merely the examples described.

[0040] For example, the steps recited in any method or process claims may be executed in any order and are not limited to the specific order presented in the claims. Additionally, the components and/or elements recited in any apparatus claims may be assembled or otherwise operationally configured in a variety of permutations and are accordingly not limited to the specific configuration recited in the claims. [0041] Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problem or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components of any or all the claims.

[0042] As used herein, the terms "comprise", "comprises", "comprising",

"having", "including", "includes" or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.

Claims

We claim:

1. An electronic cooling unit comprising: a heat exchanger suitably canted off axis in relation to gravity to permit gravimetrically assisted ambient air flow through said heat exchanger; and a plurality of fins affixed to said heat exchanger suitably adapted to reduce the probability of blockage resulting from foreign object debris contained within the ambient air flow.

2. The apparatus of claim 1, further comprising: a fan configured to move ambient air across the heat exchanger; and an air duct positioned between the heat exchanger and the fan.

3. The apparatus of claim 2, wherein the fan is configured to temporarily cease operation when the electronic cooling unit is submerged in water.

4. The apparatus of claim 1, further comprising: a first cooling line suitably adapted to move a fluid through the heat exchanger; and a second heat exchanger suitably adapted to transfer heat to or from the first cooling line.

5. The apparatus of claim 1, further comprising a protective element substantially covering the cooling unit, wherein the protective element comprises a first opening and a second opening configured to provide a flow path for ambient air through the electronic cooling unit. he apparatus of claim 5, wherein the first opening and second opening are further configured to prevent a direct line of sight into the electronic cooling unit.

7. An electronic cooling unit system comprising: a first heat exchanger suitably canted off axis in relation to gravity to permit gravimetrically assisted ambient air flow through said heat exchanger; a plurality of fins affixed to said heat exchanger suitably adapted to reduce the probability of blockage resulting from foreign object debris contained within the ambient air flow; a first cooling line configured to pass a first fluid through said first heat exchanger; and a second heat exchanger suitably adapted to transfer heat to said first cooling line.

8. The system of claim 7, further comprising: a fan configured to move ambient air across the first heat exchanger; and an air duct positioned between the first heat exchanger and the fan.

9. The system of claim 8, wherein the fan is configured to temporarily cease operation when the electronic cooling unit is submerged in water.

10. The system of claim 7, further comprising a second cooling line suitably adapted to move a second fluid through the second heat exchanger and transfer heat to said first fluid.

1 1. The system of claim 10, wherein the second cooling line is configured to circulate the second fluid from the second heat exchanger to a remote location.

12. The system of claim 10, wherein the second cooling loop is configured to absorb heat from an electronics assembly essentially attached to the electronic cooling unit.

13. The system of claim 12, wherein the second heat exchanger comprises a coldplate suitably configured to absorb heat from an electronics assembly essentially attached to the electronic cooling unit.

14. The system of claim 7, further comprising a protective element substantially covering the cooling unit, wherein the protective element comprises a first opening and a second opening configured to provide a flow path for ambient air through the electronic cooling unit.

15. The system of claim 14, wherein the first opening and the second opening are configured with an overlapping multi-layered element suitably adapted to provide a non-straight flow path for ambient air through the first and second openings.

16. The system of claim 14, wherein the first opening and the second opening are configured with a chevron shaped element suitably adapted to provide a non-straight flow path for ambient air through the first and second openings.

17. A method for cooling electronic equipment comprising: moving ambient air through a heat exchanger suitably canted off axis in relation to gravity to permit gravimetrically assisted ambient air flow through said heat exchanger, wherein the heat exchanger comprises a plurality of fins affixed to the heat exchanger suitably configured to withstand clogging from foreign object debris contained within the ambient air flow; and exchanging heat from a first cooling line to the ambient air flow.

18. The method of claim 17, further comprising: a second heat exchanger suitably adapted to transfer heat to the first cooling line; and a second cooling line suitably adapted to exchange heat from a remote heat source with the first cooling line through the second heat exchanger.

19. The method of claim 18 further comprising a protective covering that at least partially covers at least one of said first heat exchanger and said second heat exchanger.