COOLING SYSTEM UTILIZING CARBON NANOTUBES FOR COOLING OF ELECTRICAL SYSTEMS
A cooling system to cool the airflow through a electrical system includes a CNT heat exchanger module disposed within a housing of the electrical system, a cooling device configured to receive a coolant, a unit board disposed within the housing of the electrical system, and an air flow device configured to pass air across at least a portion of the unit board and at least a portion of the CNT heat exchanger module. The CNT heat exchanger module includes a member having a hole defined therethrough and a plurality of carbon nanotubes (CNTs) attached to the member. The coolant is propagated through the hole in the member so as to dissipate the heat generated by the electrical system.
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1. Field of the Invention
Embodiments disclosed herein generally relate to a cooling system for cooling computer servers. More specifically, embodiments disclosed herein relate to an improved cooling system employing carbon nanotubes (CNTS) for use with computer servers.
2. Background Art
Removal of heat has become one of the most important challenges facing computer system designers today. The computer industry is challenged by thermal management of their high performance and high power electronic components. A number of attempts to improve thermal cooling have been taken in the past, such as by reducing thermal resistance of fan-driven cooling air and the junction temperature of high heat flux electronic components, such as central processing units (CPUs), application-specific integrated circuits (ASICs), and other high heat electronic components. However, the ever increasing demand for processing speed is pushing the envelope beyond what is attainable using traditional air cooling systems.
As the rate of power dissipation from electronics components, such as high performance server units, continues to increase, as shown in
When standard cooling methods are no longer adequate, computer manufacturers have to reduce the speed of their processors to match the capacity of existing cooling apparatus, take a reliability hit due to inadequate cooling using existing cooling apparatus, or delay release of their product until a reliable cooling apparatus for removal of heat from high heat dissipating electronic components are made available. Additionally, thermal management of high heat flux server units necessitates the use of bulky heat fan and heat sink assembly units.
SUMMARY OF INVENTIONIn one aspect, embodiments of the present invention relate to a cooling system to cool the airflow through a electrical system, comprising: a CNT heat exchanger module disposed within a housing of the electrical system, the CNT heat exchanger module comprising: a member having a hole defined therethrough; and a plurality of carbon nanotubes (CNTs) disposed on the member; a cooling device disposed within the housing of the electrical system and configured to receive a coolant, wherein the coolant is propagated through the hole in the member so as to dissipate the heat generated by the electrical system; a unit board disposed within the housing of the electrical system; and an air flow device configured to pass air across at least a portion of the unit board and at least a portion of the CNT heat exchanger module.
In one aspect, embodiments of the present invention relate to a cooling apparatus for cooling an electrical system comprising: a member having a hole defined therethrough disposed near a heat-generating unit board; a plurality of carbon nanotubes (CNTs) attached to the member, wherein a coolant is propagated through the hole in the member so as to dissipate the heat generated by the heat-generating unit board; and an air moving device for moving air across at least a portion of the heat-generating unit board and across at least a portion of the member.
In one aspect, embodiments of the present invention relate to a method of cooling air flow through an electrical system, comprising: disposing a cooling apparatus near a heat-generating unit board, wherein the cooling apparatus comprises at least a member with CNTs disposed on the member; connecting the member to a cooling device; moving air across the heat-generated unit board; moving air across the member; and moving coolant from the cooling device through the member so as to transfer heat generated by the heat-generating unit board.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
Specific embodiments of the present invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures may be denoted by like reference numerals for consistency.
Advances in nano-materials and the development of economical and robust manufacturing methods for carbon nanotubes is making it possible to incorporate carbon nanotube (“CNT”) technology design and fabrication of heat exchangers using highly efficient CNT technology. When used as a heat absorbing and heat rejecting heat exchanger for an active cooling unit (pumped liquid or refrigeration system), substantial amount of heat may be removed without need for use of bulky and inefficient conventional refrigeration components.
Referring now the
In other embodiments of the invention, thermal management of a high heat flux server box is achieved using a cooling system 15, which may include a removable modular liquid or refrigeration unit utilizing CNT heat exchangers 8, for cooling of the heat generating processor and electronics components by placing the self-contained and easily removable CNT heat exchanger modules 8 in the direction of cooling air flow 3 at desired locations in a server chassis, also known as a housing 12. CNT heat exchangers 2 absorb the heat, acting as the absorbing unit of the active cooling system, from the propagation of air over the CNT heat exchangers causing the absorption of heat by the cooling coil (heating of the cooling fluid in the case of liquid cooling and boiling of refrigerant in the case of the refrigeration cooling, wherein both may be called coolants) and therefore reducing the temperature of the air flowing through the heat absorbing CNT heat exchanger. Absorbed heat is then moved through a member, with a hole defined therethrough, using the coolant and the absorbed heat is released to the ambient away from the electronics components over the board and out of the server chassis. In accordance with other embodiments of the invention described herein, a miniature liquid pump or a miniature refrigeration compressor unit may be used with the CNT heat exchanger module. The advantage of such a design is the increase in thermal performance and a reduction in cost for the packaging material, allowing traditional air-cooling schemes to be used for thermal management of high heat processors. Another advantage is minimizing the size and space utilization due to the high thermal performance of CNT heat exchangers. Further, the ability to form and build heat exchangers of different geometrical configurations may also be an advantage of the design.
Referring now to
Referring now the
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Referring now to
In other embodiments of the invention, more than one CNT heat exchanger module 8 are attached to a refrigeration system 9 comprised of a condenser and at least one compressor as shown in
In other embodiments of the invention, a CNT heat exchanger module, also known as a modular removable active cooling unit 8, utilizing CNT heat exchangers 2 are used for cooling and thermal management of high heat server boxes. In addition to providing substantial heat removal ability, these embodiment allow for the reduction in size and the number of heat sink and all other second level thermal management mechanism currently in practice.
Further, other embodiments of the invention, for example as shown in
Referring now to
Other embodiments provide a member 1 that is far larger than the CNTs attached thereto as shown in
Referring now to
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In the
One benefit of the embodiments shown in
Referring now to
In addition to the above discussed benefits and advantages, embodiments of the present disclosure may provide for one or more of the following advantages. First, embodiments disclosed herein may provide for active fluid cooling that may provide desired thermal management solution to a wide range of thermal dissipation applications. Additionally, utilization of CNT material and technology may provide the highest known thermal conductivity (higher than diamond) for a heat exchange medium while possibly providing geometrical flexibility for desirable and space-fitting heat exchanger design and fabrication. Further, the application of a cooling system in according with one of the above embodiments may dramatically improve thermal management of high power computer servers by reducing temperature of the cooling air to inlet conditions at any given location inside of the server box. The proposed embodiments may provide the ability to utilize effective cooling mediums ranging from water, water-glycol, dielectrics to direct expansion refrigeration coolants that are associated with the high thermal conductivity of the CNT material. This may provide the highest level of thermal transport ever experienced in the electronics industry.
Combining highly conductive CNT material in the form of configurable microchannel heat exchangers with an active refrigeration or liquid cooling solution may provide the widest range of thermal management schemes ever developed in the electronics industry for flexible cooling of electronics components in data centers. As opposed to other applications of active cooling systems, utilizing CNT technology may provide the most efficient and flexible manufacturing method for building heat exchangers used in a closed loop of an active cooling system. By virtually removing the hot regions inside of a server box, through a cooling system 15 as described in the above embodiments which utilize highly flexible CNT microchannel heat exchangers 2, the reliability of the parts may be increased. Using a removable modular cooling system as described at least one of the above embodiments, which utilize CNT technology in heat exchangers, may provide an opportunity for drastically reducing the cost of thermal management of servers in data centers by minimizing irreversibility and inefficiencies associated with the traditional computer room air conditioner (“CRAC”), fans and heat sink schemes.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Claims
1. A cooling system to cool the airflow through a electrical system, comprising:
- a CNT heat exchanger module disposed within a housing of the electrical system, the CNT heat exchanger module comprising: a member having a hole defined therethrough; and a plurality of carbon nanotubes (CNTs) disposed on the member;
- a cooling device disposed within the housing of the electrical system and configured to receive a coolant, wherein the coolant is propagated through the hole in the member so as to dissipate the heat generated by the electrical system;
- a unit board disposed within the housing of the electrical system; and
- an air flow device configured to pass air across at least a portion of the unit board and at least a portion of the CNT heat exchanger module.
2. The cooling system of claim 1, wherein the CNT heat exchanger module further comprises a porous material that encloses at least a portion thereof.
3. The cooling system of claim 1, wherein at least one of the plurality of CNTs is attached to the member.
4. The cooling system of claim 1, wherein at least one of the plurality of CNTs is monolithically formed with the member.
5. The cooling system of claim 1, wherein the electrical system is a computer server.
6. The cooling system of claim 1, wherein the CNT heat exchanger module is fluidly connected to the cooling device.
7. The cooling system of claim 1, wherein the coolant is at least one of a liquid and a gas for cooling.
8. The cooling system of claim 1, wherein the CNT heat exchanger module comprises a plurality of CNT heat exchanger modules, wherein each of the plurality of CNT heat exchanger modules are fluidly connected to the cooling device.
9. The cooling system of claim 1, wherein the CNT heat exchanger module is removably attached to a cooling device.
10. The cooling system of claim 1, wherein the cooling device comprises one of a pumped liquid system and a refrigeration system.
11. The cooling system of claim 1, wherein a cross-section of the member comprises one of a circular shape, an oval shape, a rectangular shape, a square shape, and a triangular shape.
12. The cooling system of claim 1, wherein the member comprises at least one of a metal, a polymer, a plastic, an epoxy, and a CNT.
13. The cooling system of claim 1, wherein the CNT heat exchanger module further comprising:
- a second member having a hole defined therethrough with a plurality of CNTs attached thereto;
- wherein porous material is disposed about at least a portion of the second member.
14. The cooling system of claim 1, wherein at least one of the plurality of CNTs comprises one of a single-walled CNT and a multi-walled CNT.
15. The cooling system of claim 1, wherein at least one of the plurality of CNTs comprises one of an armchair structure, a zigzag structure, and a chiral structure.
16. The cooling system of claim 1, wherein the CNTs are attached to one of at least an inner surface and an outer surface of the member.
17. The cooling system of claim 1, further comprising:
- an internal member having a hole defined therethrough;
- wherein the internal member is disposed within the first member.
18. The cooling system of claim 17, wherein the internal member comprises a plurality of CNTs attached thereto.
19. A cooling apparatus for cooling an electrical system comprising:
- a member having a hole defined therethrough disposed near a heat-generating unit board;
- a plurality of carbon nanotubes (CNTs) attached to the member, wherein a coolant is propagated through the hole in the member so as to dissipate the heat generated by the heat-generating unit board; and
- an air moving device for moving air across at least a portion of the heat-generating unit board and across at least a portion of the member.
20. The cooling apparatus of claim 19, wherein the member is fluidly connected to a cooling device.
21. The cooling apparatus of claim 19, further comprising a CNT heat exchanger module comprised of a porous material disposed about at least a portion of the member and the plurality of CNTs.
22. A method of cooling air flow through an electrical system, comprising:
- disposing a cooling apparatus near a heat-generating unit board, wherein the cooling apparatus comprises at least a member with CNTs disposed on the member;
- connecting the member to a cooling device;
- moving air across the heat-generated unit board;
- moving air across the member; and
- moving coolant from the cooling device through the member so as to transfer heat generated by the heat-generating unit board.
23. The method of cooling air flow through an electrical system of claim 22, further comprising:
- dissipating heat from the coolant with a cooling device fluidly connected to the member.
Type: Application
Filed: Aug 8, 2008
Publication Date: Feb 11, 2010
Applicant: SUN MICROSYSTEMS, INC. (Santa Clara, CA)
Inventors: Ali Heydari (Albany, CA), Chien Ouyang (Sunnyvale, CA)
Application Number: 12/188,818
International Classification: F28D 15/00 (20060101);