US20080156463A1

US20080156463A1 - Cooling Liquid Device for a Computer

Info

Publication number: US20080156463A1
Application number: US11/665,487
Authority: US
Inventors: Jean-Claude Chereau
Original assignee: J C C Chereau Aeronautique
Current assignee: J C C Chereau Aeronautique
Priority date: 2004-10-15
Filing date: 2005-10-14
Publication date: 2008-07-03
Also published as: EP1803051B1; JP2008517364A; ATE433145T1; FR2876812A1; FR2876812B1; DE602005014797D1; WO2006042945A1; EP1803051A1; ES2324886T3

Abstract

The invention relates to a liquid cooling device for a computer, provided for a housing (1), enclosing a computer processor. In order to dissipate the heat by a radiant effect, the device advantageously comprises heat-removal means (20, 22, 23, 25) within the housing, attached to a lower wall (100), an upperwall (105) and at least one lateral wall (102, 103) of the housing (1). Each of the heat-removal means has two walls (P1, P2) at a separation from each other, made from a thermally-conducting material between which at least one circulation channel for a fluid is formed which is connected by a closed circuit (3) to at least one cooling element (61, 62, 63, 64, 65), attached to a power component in the computer. A pump (30), integrated in the circuit (3), circulates the fluid which permits a dissipation of the heat across the walls.

Description

The present invention relates to the field of cooling systems for a computer. The invention relates more particularly to a cooling liquid device that allows cooling a computer other than with the noisy forced ventilation systems.
The microprocessors become more and more powerful and various components of a computer need significant cooling. Nowadays, to cool those elements, mostly blocks of aluminum associated to very noisy powerful ventilators that consume a lot of energy are used and this can produce high temperature within the housing of a computer.
In warm countries where the temperature is generally above 30° C., the system by induced air ventilator is not suitable for normal operating conditions. It often requires a room with air conditioning.
Cooling systems by liquid circulation are known, particularly in documents US 2002/196604, GB 2 349 985, WO 99/11108 or U.S. Pat. No. 6,234,240, in the housing of a computer for cooling certain electronic components. However, these systems have often limited efficiency, do not always allow to be operated without power ventilators for the cooling of powerful microprocessors and furthermore they cause cluttering (additional space to integrate heat-removal elements of the circuit).
The objective of this invention is to overcome one or several inconveniences of the prior art by defining a cooling device which is really efficient and requiring no noisy ventilation.
For this purpose, this invention relates to a cooling liquid device for a computer including heat-removal means attached to at least one wall in order to dissipate the heat by radiant effect, each of the heat-removal devices including two spaced walls made of heat conducting material between which is formed at least one circulation channel for fluid, characterized in that at least one of the heat-removal components constitutes at least an element of wall of the housing enclosing the computer processor and in that said channel is linked to at least one cooling element attached to an electronic component of the computer by a closed circuit including a pumping device; said heat-removal means being more or less spread out over the whole housing to let the housing play a role of heat exchanger with the outside.
Thus the invention allows a cooling which is only done by the housing of the computer without increasing the size of the housing. No specific radiator is necessary and the device can operate without power ventilators, thus making the computer very silent.
According to another particularity, said two walls are flat and formed by a sheet layer of aluminum or copper, and the spacing between those walls is included between 2 and 5 mm.
Thus, the invention allows an efficient cooling of heating components while minimizing the volume taken up by the cooling circuit.
According to another particularity, the heat-removal devices are attached to the wall of the housing having lower walls, upper walls and lateral walls to determine the internal volume which serves to enclose the computer processor, a first heat-removal means being attached to a lower wall of the housing, a second heat-removal means being attached to an upper wall of the housing, at least a third heat-removal means being attached to at least one lateral wall of the housing.
According to another particularity, each of the heat-removal means has two walls which constitute the housing.
According to another particularity, at least one of the heat-removal means is attached to a wall which is made of heat conducting material of a cabinet.
According to another particularity, the closed circuit of cooling liquid consists of at least one outlet closed by a closing element, an extension device provided either at least at one outlet or in bypass, in order to allow the dilatation of the cooling liquid.
According to another particularity, the expansion device consists of a flexible and waterproof membrane made of plastic and is placed inside the housing.
According to another particularity, the closed circuit consists of:
a plurality of connecting pipes to supply liquid to each circulation channel of the heat removal means;
a liquid flow control device;
a liquid distribution means.
According to another particularity, the cooling element is equipped with a circulation zone of a cooling liquid between two walls facing one another, of which at least one wall is placed beside a microprocessor and/or other power components of the computer.
According to another particularity, each of the cooling elements is only in contact with an electronic component which releases heat, where the fasteners have been provided on each cooling element to integrate the latter to the electronic component to be cooled.
According to another particularity, the closed circuit includes:
a cooling element to cool a supplying device of the computer;
a cooling element to cool an electronic component of the graphic board type;
a cooling element to cool the mass storage device;
a cooling element to cool an exchange controlling between the microprocessor and the working memory of the computer;
a cooling element to cool the microprocessor of the computer.
According to another particularity, control and security sensors are provided in at least one heat-removal means attached to one of the housing walls to measure the temperature and/or the pressure of the cooling liquid.
According to another particularity, the means of optical, magnetic and/or radio detection are furthermore provided to estimate the qualitative properties of the cooling liquid.
According to another particularity, the closed circuit is linked to a heat exchanger whether integrated or not of the housing, the cooling liquid being chosen among water, oil, mono ethylene glycol and similar cooling liquid of the type having one or several alcohol functions.
According to another particularity, the closed circuit consists of connection means to at least one portion of circuit external to the housing, thus allowing the cooling of said cooling liquid.
According to another particularity, at least one air agitator with low speed of rotation is provided inside the housing to generate a micro sweeping of the air allowing the cooling of small components of the computer.
According to another particularity, the closed circuit is equipped with at least one electric resistance element to transform the cooling into heating.

This invention, with its characteristics and advantages, will be more clearly understood at the reading of the description in reference to the attached drawings given as non limiting examples, wherein:

FIG. 1 represents schematically the connections between the constitutive elements of the device in an embodiment of the invention;

FIG. 2 shows a circulation scheme of cooling liquid in a computer housing according to the embodiment of the invention;

FIG. 3 represents a perspective view of the interior of the computer housing being equipped with a liquid cooling device according to the invention;

FIG. 4 shows a local cooling element by radiant effect which can be connected to the cooling circuit to cool a power component.

The device according to the invention presents in an advantageous way an architecture with a small size to cool the power components of the computer and various peripherals: hard disk, power supply, etc. For this purpose, the device integrates a circulation of liquid: oil, water, or other heat conducting liquid products. In the present housing, an automobile glycol such as mono ethylene glycol is very suitable for cooling purposes. The similar cooling liquids having one or several alcohol functions can naturally be used. A volume of liquid of less than one liter is sufficient, for example 0.8 L.
The liquid cooling device allows for equipping a housing (1) of a computer central unit. Such a housing (1) used to enclose the computer processor includes lower walls (100), upper walls (105) and lateral walls (102, 103). In the interior volume delimited by these walls (100, 102, 103, 105), the device includes different cooling and heat-removal means. In the examples of FIGS. 1 and 2, a first heat-removal means (20) is attached to a lower wall (100), a second heat-removal means (25) is attached to an upper wall (105) and third heat-removal means (22, 23) are leaned against at least one lateral wall (102, 103). Each of these heat-removal means (20, 22, 23, 25) allows dissipating the heat towards the outside of the housing (1) by radiant effect, as illustrated by the arrows represented in FIG. 2. In a preferred embodiment of the invention, each of said first, second and third heat-removal means (20, 22, 23, 25) includes two spaced walls (P1, P2, FIG. 3) made of heat conducting material, in view to allow the circulation of cooling liquid in at least one circulation channel (200) for fluid. Said channel (200) is connected to at least one cooling element (6) attached to an electronic component of the computer by a closed circuit (3). The channel (200) formed in the provided spacing (2) between the two walls (P1, P2) can have an arrangement of the serpentine, circular type or any other arrangement to allow the radiant effect.
The main advantage of such heat-removal means (20, 22, 23, 25) attached or fixed against the walls of the housing (1) is to utilize the housing (1) of the computer as a radiator. It dissipates the heat in the ambient temperature thanks to the cooling liquid which circulates inside the device. This cooling liquid circulates at least in a closed circuit (3) equipped with a pumping device (30) as illustrated particularly in FIG. 2. In an embodiment of the invention, the entire housing (1) or at least certain surfaces of the housing (1) used to dissipate the heat are for example made of aluminum (alumina melting) or other suitable metal (or certain sufficiently conducting plastics), ensuring transmission of heat by radiation or by convection. In other words, the housing (1) plays the role of a heat exchanger with the outside. By reducing the thickness of the walls (100, 102, 103, 105) of the housing (1) to a minimum, the heat exchanges with the outside are thus improved because the thermal resistance of the cover (23) becomes lower. The heat exchange surface with the inside air to be cooled can furthermore be increased by using embossing.
In alternatives of realization, at least one of the heat-removal means (20, 22, 23, 25) can constitute at least one element of the wall of the housing (1) The housing (1) then includes two walls (P1, P2) between which at least one circulation channel (200) for fluid is formed. In another other type of alternative, one or several walls consisting of heat conducting material of a cabinet can be used to dissipate the heat. Thus a metallic table on which the computer is placed can be suitable for obtaining the radiant effect, at least one of the heat-removal means (20, 22, 23, 25) being attached to this table.
As illustrated in FIG. 3, the two walls (P1, P2), being parallel to the adjacent surface of the housing (1), are for example flat and formed by a sheet layer of aluminum or copper. The spacing (2) between these walls (P1, P2) is included between 2 and 5 mm to reduce the overall dimension in the housing (1). A thickness which can go until 10 mm is equally foreseeable. On each of the cooling means (20, 22, 23, 25) attached against the interior surfaces of the housing (1), an inlet (221) and an outlet (222) are provided in the form of connectors ready to receive the connecting pipes (T) to the rest of closed circuit (3). As illustrated in FIG. 3, the closed circuit (3) of cooling liquid circulation consists in at least an outlet blocked by a closing element (51). An expansion device (50) is furthermore provided with such an outlet to allow a dilatation of the cooling liquid. Alternatively, the expansion device (50) can be used in a bypass of the circuit (3). This expansion device (50), used inside the housing (1), includes for example a flexible and waterproof membrane in plastic material. An accordion shape or similar for this device (50) allows the shrinkage/expansion movement authorizing the dilatation of liquid without increasing the pressure within the circuit (3).
In a preferred embodiment of the invention, the cooling means (20) of the lower part of the housing (1) forms a lower compartment on which a computer can be placed, as illustrated in FIG. 3. This compartment can be equipped with legs and a strip of filtration foam (not shown) used to filter air entering the housing (1).
In reference to FIGS. 1 and 3, control and security sensors (4) are provided in heat-removal means attached to one of the walls (100, 102, 103, 105) of the housing (1) to measure the temperature and/or pressure of the cooling liquid. Optical, magnetic and/or radio detection means can be provided to estimate the qualitative properties of the cooling liquid. The opacity of a liquid used as cooling liquid can be then estimated by an optical sensor.
As shown in FIG. 2, the closed circuit (3) can be provided with several connecting pipes (T) to supply the cooling liquid to each circulation channel (200) of heat-removal means (20, 22, 23, 25). The cooling elements (6) forming local radiators are also provided in the same manner. Said circuit (3) provides also a cooling liquid flow controlling device (32) and distribution means (33) for this liquid. In addition, a liquid filter (31) can be provided to the closed circuit (3). The pumping device (30) used is for example a small-sized micro-pump installed within the housing (1). A housing for degassing the liquid can be furthermore provided.
In the embodiment of FIGS. 1 and 3, the heat-removal device (20) attached to the lower wall (100) incorporates two inlets (201, 202) for the cooling liquid and an outlet (203). The pumping device (30) is for example connected to this outlet (203) by the intermediary of a pipe (T) of tubular type made of semi-flexible resistant rubber or similar. The pipes (T) utilized for the connection between cooling elements are also of that type. Transparent pipes can be utilized to facilitate the optical/visual inspection of the cooling liquid circulation.
In reference to FIGS. 1 and 4, at least one cooling element (6) provided with a circulation zone of cooling liquid between two walls facing one another is installed on a microprocessor and/or other power components of the computer. In practice, each of these cooling elements (6) can be made of a small hollow housing made of a material of the aluminum, copper type or any other metallic material in which the liquid/fluid circulates with the help of a micro pump or other pumping device. The cooling element (6) is connected to the closed circuit (6) by the pipes (T) to be supplied with cooling liquid. Each of these cooling elements (6) forms a local radiator (61, 62, 63, 64, 65, FIG. 1) only in contact with an electronic component which releases heat. Fasteners (600) can be provided on each cooling element (6) to solidarize this cooling element against the electronic component to be cooled. These fasteners (600) can include springs provided with hooks or other fastening points or, alternatively, flexible stainless steel blades, which are fixed around the components to be cooled. Any other fastening device (screw, etc.) can be also provided. Alternatively, these cooling elements (6) are simply placed on the electronic parts to be cooled by sticking. The direct contact with the component allows perfect heat conductivity and optimizes the cooling. The cooling means (20, 22, 23, 23) placed against the interior surfaces of the housing (1) and the cooling elements (6) each have for example a generally parallelepipedic shape and have an inlet connection respectively an outlet connection for the cooling liquid. For the local cooling elements (6) of a component, a face is provided for the contact with the component, while the opposite face contains respective inlet and outlet connections (601, 602) for the cooling liquid.
In an embodiment of the invention, a structure having at least two levels is provided for at least one of the cooling elements (6). A first level having a reduced thickness of around a few millimeters consists of an isolator substrate having a strong thermal coefficient of isolation to form an interface of isolation between the component and the second level crossed by the cooling liquid. Said first level can have a stratified structure. This cooling element with several levels can be provided particularly for a component supplied with a high voltage (for example 220 V). The second level is fixed to the first level by means of clipping/screwing or similar fastening elements. Such a cooling element (6) is adapted to cool a classical power supply device.
In reference to FIG. 1, the cooling liquid distribution means (33) can be connected to certain of the said cooling elements (6) associated to the power components. The closed circuit (3) can moreover include:
a cooling element (61) to cool a supply device of the computer;
a cooling element (62) to cool an electronic component of the graphic board type;
a cooling element (63) to cool mass storage memory of the computer (hard disk or memory card);
a cooling element (64) to cool an exchange controlling component between the microprocessor and the working memory of the computer;
a cooling element (65) to cool the microprocessor of the computer.
In the example of FIG. 1, the outlet connections (602) of these cooling elements (6) are connected by the pipes (T) to the inlet of the heat-removal means (22, 23, 25) installed against walls (102, 103, 105) of the housing (1). The heat-removal means (20) associated to the lower wall (100) receives for example through a first inlet (201) the cooling liquid having circulated along the two distinct walls (102, 105) via the heat-removal means (22, 25) connected serially, and through a second inlet (202) the cooling liquid having circulated along the other wall (103) of the housing via another heat-removal means (23). Although FIG. 1 illustrates a circuit (3) wherein the cooling liquid circulates first in the said elements (6) locally cooling the electronic components before circulating along the walls of the housing (1), it should be understood that other embodiments of close circuit (3) can be foreseen with different parallel and/or serial connections. Said cooling elements (6) can be for example partially eliminated.
In the embodiment of FIG. 1, the closed circuit (3) is linked to a heat exchanger (K) integrated in the housing (1). An external exchanger can also be provided. The utilization of an exchanger system offers a security to prevent overheating. The closed circuit (3) also includes for example means of connection to at least one portion of circuit outside the housing (1) allowing to cool said cooling liquid.
In realization alternatives, one or several Pelletier effect cells (not shown) can be additionally provided, used particularly to cool the processor or power supply devices. Any other component can also be cooled in such a way. The invention provides a cooling with a low consumption of energy and an absence of noise. In the embodiment of FIGS. 1 and 3, the computer is cooled in a very simple way without a power ventilator; only two air agitators (5) having a low speed of rotation are utilized as safety device for a micro-sweeping of air in the internal part of the housing (1) in order to ensure the cooling of various small components. The overall dimension of the device according to the invention is minimal in such a way that this type of cooling is very suitable for laptops.
In a preferred embodiment of the device according to the invention, one or two low-speed air agitators (5) having a big diameter ensure the sweeping of internal air in a practically inaudible manner at about 18 db. The air flow produced in such a way cools the internal walls as well as various small components of small power. This air flow can be also canalized to ensure the cooling of hot parts of any possible Pelletier systems. Likewise, the air flow can ensure the cooling of hard disks or of their surface electronics and power supply, all that with incoming filtered air by the intermediary of a filtration foam strip.
It is also possible, for application in cold surroundings (with a temperature around 0° C. for example or lower), to provide the closed exchanger circuit (3) with at least one element having an electric resistance electronically controlled to make sure that a sufficiently high temperature of the computer is maintained, for example around 15-20° C. The sweeping of hot air generated by the air agitators (5) prevents any possible condensation. Because of air being filtered, the housing (1) can be in slight overpressure and thus it can prevent an accumulation of dust in the housing (1) and for example protect the optics from dust.
The air agitators (5) fixed to the lower compartment forming an air exchanger recover the air penetrating through the filtration foam strip. The air transporting holes coming from the filtration foam strip cross the upper part of the compartment to let the suctioned air enter under the housing (1). In an embodiment of the invention, a foam filter of size 5×5×80 (cm) is utilized attached under the housing (1). This filter is inserted between the base or support and the lower compartment. The air sucked in that way under the housing (1) is cooled by several degrees on the base or support on which the housing is placed. For tiles or concrete or support of that type, the temperature of incoming air is decreased by several degrees, which is very appreciated in warm countries. The air agitators (5) are activated for example by a regulator system according to the elevation of temperature. The operation of Pelletier effect systems is also managed by a regulator system.
One of the advantages of the invention is to supply a cooling with strong dissipation of heat, which allows using several computers provided with the liquid cooling device in a room without problem of temperature elevation. Moreover, the cooling can be done in a silent manner, by eliminating the power ventilators which are very noisy and consume a lot of energy.
Another advantage of the invention is that the computer is cooled in a very simple way with slow heat variation, which ensures the longevity of the cooled parts and that with a very low cost of production. It is sufficient to add to the housing (1) of a computer systems with two layers of sheet, aluminum or various metals or certain sufficiently conducting plastics with spacing (2) between the two parts of a few millimeters of thickness to let a liquid circulate with the help of a micro pump, which enables to take on the role of a radiator.
Moreover, the utilization of a liquid circulation with heat resistance allows also to heat the computer, thus authorizing applications in extreme conditions (very hot/very cold).
The invention provides advantageously a low manufacturing cost and a good adaptability on most computers on the market by welding or sticking radiator elements, including on laptops (the overall dimension is in fact very reduced because the housing of desktop type includes a thickness lower than 1 to 3 millimeters only). Moreover, the absence or reduction of aeration openings allows to reduce or to eliminate the presence of dust in the internal part of the housing.
It should be obvious for the man of the art that the present invention allows the embodiment under other numerous specific forms without deviating from the scope of the invention as it is claimed.

Claims

1. A liquid cooling device for a computer, including heat-removal means (20, 22, 23, 25) attached to at least one wall (100, 102, 103, 105) to dissipate the heat by radiant effect, each of the heat-removal means including two spaced walls (P1, P2) made of a thermally-conducting material between which is formed at least one circulation channel (200) for a fluid, said channel 200 being linked to at least one cooling element (6) attached to an electronic component of the computer by a closed circuit (3) including a pumping device (30), Characterized in that:

each of the two walls (P1, P2) delimit the channel (200); and

the walls (P1, P2) of at least one of the heat-removal means (20, 22, 23, 25) constitute an external wall (P1) and an internal wall (P2) of a housing (1) enclosing a computer processor, said heat-removal means (20, 22, 23, 25) being substantially spread out on the whole of the housing (1) to let the housing (1) play the role of heat exchanger with exterior.

2. The device according to claim 1, wherein said two walls (P1, P2) are flat and formed by a sheet layer of aluminium or copper, the spacing (2) between those walls (P1, P2) being included between 2 and 5 mm.

3. The device according to claim 1, wherein the heat-removal means (20, 22, 23, 25) are attached to the walls of a housing (1) of the type having the lower wall (100), upper wall (105), and the lateral walls (102, 103) to delimit an interior volume used to close a computer processor, the first heat-removal means (20) being associated to a lower wall (100) of the housing (1), the second heat-removal means (25) being associated to an upper wall (105) of the housing (1); at least a third heat-removal means (22, 23) being associated to at least a lateral wall (102, 103) of the housing (1).

4. The device according to claim 1, wherein each of the heat-removal means (20, 22, 23, 25) consists of two walls constitutive of the housing (1).

5. The device according to claim 1, wherein at least one of the heat-removal means (20, 22, 23, 25) is attached to a wall made of a thermally-conducting material of a cabinet.

6. The device according to claim 1, wherein the closed circuit (3) of cooling liquid circulation consists of at least an outlet blocked by a closing element (51), an expansion device (50) being provided either to at least an outlet, or a bypass, to allow dilatation of the cooling liquid.

7. The device according to claim 3, wherein the expansion device (50) consists of a flexible and waterproof membrane consisting of a plastic material and is installed within the housing (1).

8. The device according to claim 1, wherein the closed circuit (3) consists of:

a plurality of connecting pipes (T) to supply the liquid to each circulation channel (200) of the heat-removal means (20, 22, 23, 25);

a liquid flow controlling device (32);

liquid distribution means (33).

9. The device according to claim 1, wherein the cooling element (6) is provided with a cooling liquid circulation zone between two walls facing one another of which at least one is attached to a microprocessor and/or other power components in the computer.

10. The device according to claim 1; wherein each of the cooling elements (6) is only in contact with an electronic component that releases heat, fasteners (600) being provided on each cooling element (6) to solidarize this latter against electronic component to be cooled.

11. The device according to claim 1, wherein the closed circuit (3) includes:

a cooling element (61) to cool the supplying device of the computer;

a cooling element (62) to cool an electronic component of the graphic board type;

a cooling element (63) to cool a mass storage device in the computer;

a cooling element (64) to cool an exchange controlling component between the microprocessor and the working memory of the computer;

a cooling element (65) to cool the microprocessor of the computer.

12. The device according to claim 3, wherein the sensors (4) of control and security are provided in at least one heat-removal means attached to one of the walls (100, 102, 103, 105) of the housing (1) to carry out the measurement of temperature and/or the pressure of the cooling liquid.

13. The device according to claim 12, wherein the means of optic, magnetic and/or radio detection are furthermore provided to estimate the qualitative properties of the cooling liquid.

14. The device according to claim 3, wherein the closed circuit (3) is linked to a heat exchanger (K) integrated or not to the housing (1), the cooling liquid being a liquid chosen among water, oil, mono ethylene glycol and similar cooling liquid of the type having one or several alcohol functions.

15. The device according to claim 3, wherein the closed circuit (3) consists of the means of connection to at least one portion of external circuit of the housing (1) allowing the cooling of said cooling liquid.

16. The device according to claim 3, wherein at least an air agitator (5) with low speed of rotation is provided in the interior of the housing (1) to generate a micro sweeping of the air allowing the cooling of small components of the computer.

17. The device according to claim 1, characterized in that the closed circuit (3) is equipped with at least one element having electric resistance to transform the cooling into heating.