Patent Application
20060238980
The present invention relates to controlling temperature in heat producing electronic devices. More specifically, the present invention provides an electronics enclosure that regulates the temperature of internal heat producing electronics by using a combination of heat pipes and air passages.
Prior electronic enclosure designs or enclosures for heat producing computer devices suffer from the disadvantages of excessive noise, fluctuating internal temperature, and a lack of robustness in the cooling design of the enclosure. Furthermore, prior electronics enclosures do not provide warning signals that indicate to the user that the cooling of the electrical devices contained within the enclosure is inadequate. Furthermore, prior electronics enclosures do not automatically power down the electronic devices contained within the enclosure in response to adverse heating.
Heat is produced within the enclosure by the electronic devices contained therein. Airflow produced by forced air cooling distributes the heat generated at the heat sources into the air within the enclosure by means of convection. Forced air cooling may include any number of mechanical fans. The heated air escapes the enclosure through at least one vent, simultaneously allowing cool air from the exterior environment to enter the enclosure. It is noted that the heat produced by the electronic devices increases the temperature of the enclosure itself. The enclosure transfers the heat produced by the internal electronic devices to the exterior environment.
The rate at which the enclosure transfers heat to the air within the surrounding environment is determined by natural convection. Heat transfer by convection into a confined air space is quite inefficient, having a very slow rate of heat transfer to the exterior environment. Although a computer enclosure that is equipped with vents is not a completely confined environment, the movement of heated air through the vents is only by natural convection initiated by the difference in temperature of air within the enclosure and the temperature of the enclosure itself. Therefore, since the rate of heat transfer to the air within the enclosure and the rate of heat transfer to the enclosure itself are typically slow the vents by themselves do not supply an adequate amount of cooling to the heat producing devices contained within the enclosure.
U.S. Pat. No. 5,884,693 to Austin, et al. represents one prior cooling system for cooling an enclosure containing electronic components and devices. The Austin et al. reference provides an enclosure equipped with heat pipes, wherein the heat pipes increase heat transfer to the enclosure. However, heat transfer from the heat producing source to the enclosure is still disadvantageously controlled by natural convection. Furthermore, since heat transfer from the enclosure to the room is also by natural convection, the rate of heat transfer from the enclosure to the exterior environment is also slow.
U.S. Pat. No. 5,973,920 to Altic, et al. (“Altic, et al.”) provides another example of an enclosure for electronic devices in which a heat frame incorporates a heat sink, a connector and a mounting frame adapted for mounting multiple circuit boards into one integral component. Heat removed by the heat sink is transferred over the entire heat frame with the aid of heat pipes. The design further incorporates fins to dissipate heat through the housing of the computer. Disadvantageously, heat transfer is still controlled by natural convection.
In another prior design, a computer case is provided in which a series of copper heat pipes transfer heat from the heat source contained within the enclosure to the enclosure itself. This is a direct transfer of heat from the heat producing device to the walls of the enclosure. Nevertheless, the enclosure still relies on natural convection to transfer the heat from the enclosure to the air of the surrounding environment.
It is noted that heat transfer via natural convention may be advanced by forced air cooling through the use of motorized fans. The disadvantages of utilizing forced air cooling is the increased likeliness of mechanical failure inherent in motorized fan designs and the excessive noise that is produced by the fans operation.
With increasing computer chip density greater requirements have been placed on device cooling. Therefore, it is desirable that a system of increased cooling be provided to ensure that the computer chips of the next generation do not operate at a sub-optimum level. Further, the noise that is produced by fans and the lack of reliability associated with the moving fan parts provide additional reasons why a new cooling design is needed.
The present invention provides an electronics device enclosure having increased cooling capacity to the electronic devices contained therein. The present invention also provides an electronics device enclosure having increased cooling without the use of mechanical fans. The present invention further provides an electronics device enclosure that increases cooling to the electrical devices contained therein with a combination of heat pipes and air passages, wherein the air passages transfer heat from the enclosure to the outside environment by a chimney effect.
The present invention provides the above and more by an electronics device enclosure comprising:
The heat producing structure contained within the electronics case may be a power supply, a motherboard, drive system or any electrical device utilized in computers and personal electronics.
The intake may be a first vent positioned on a lower outside portion of a sidewall containing an air passage and the exhaust may comprise a second vent positioned on an upper outside portion of the sidewall containing the air passage. The sidewalls may further comprise at least one interior vent positioned on the lower and/or upper inside portion of the sidewall of the air passage. The vents may be positioned in any manner that removes the air that has been heated by the heat producing elements from the interior of the electronics case and draws cooler air from the exterior atmosphere.
The heat pipes that are in conductive communication with the heat producing structures and the housing of the electronics case may be aluminum or copper. The term “conductive communication” denotes that the heat pipes transfer heat from the heat producing structure to the sidewalls of the electronic case housing, which include the air passages. The flow of air through the air passage transports the heat transferred by the heat pipe to the sidewall of the electronics case to the exterior atmosphere. The rate of air flow though the sidewall of the electronics case may be dependant on the sidewalls cross section.
In another embodiment of the present invention the electronics case comprises:
The fluted sidewall has a cross-section that produces a chimney effect, which vents heated air from the housing and draws cool air from the exterior atmosphere into the housing. The term “chimney effect” denotes the movement of heated air out of the enclosure and cooler air into the enclosure resulting from a difference in pressure between the air/gasses inside the enclosure and the exterior environment.
The present invention provides an electronics device enclosure having increased cooling to vent heated air from the interior of the electronics device enclosure without the use of mechanical means. More specifically, the inventive electronics device enclosure transfers heat from the heat producing electrical devices contained therein using at least one heat pipe in conductive communication to the housing of the electronics device enclosure.
The heat that is transferred from the heat producing electronics to the housing of the electronics device enclosure is then transferred to the exterior atmosphere by at least one sidewall having an air passage that displays a chimney effect. The chimney effect promotes venting of heated air while simultaneously drawing cooled air into the air passage. The present invention is now discussed in more detail referring to the drawings that accompany the present application. It is noted that in the accompanied drawings like and/or corresponding elements are referred to by like reference numbers.
Referring to
The heat pipe 15 may comprise aluminum or copper. Aluminum is preferred due to its advantages in weight and heat conductivity. Applicants note that although
Referring back to
Examples of liquids that may be used in heat pipes 15 for computer applications include: acetone, ammonia, freon 11, freon 113, and heptane. It is noted that the previous list of heat pipe 15 liquids has been included for illustration purposes and should not serve to limit the invention to those liquids specifically mentioned, as other liquids may be utilized in the heat pipe 15 depending on the particular application and possible surface treatment of the heat pipe's 15 interior surface.
Referring back to
The chimney effect may be enhanced by including further intake and exhaust vents within the interior surfaces of the sidewall 20 of the electronics device enclosure. Although not depicted in the supplied illustrations, interior vents are contemplated and within the scope of the present invention. It is noted that any number of vents may be supplied in order to produce the most effective draw of heated air from the air passage and most effective draw of cooler air into the air passage from the exterior atmosphere.
Referring to
Referring now to
Another example of a fluted sidewall 40 is depicted in
Similar to the previously described embodiments, the upper portion of each flute 40a can have an upward dimension and a base dimension. In one embodiment, the upper dimension of the flute 40a may be equal to the base dimension of the flute 40a. In another embodiment of the present invention, the base dimension of the flute 40a may be greater than the upper dimension of the flute 40a in order to enhance the chimney effect. The chimney effect may also be advanced by increasing the flue 41 of each flute 40a.
The present invention is not limited to the cross section depicted in
Although the present invention provides increased cooling without the use of fans or blowers, fans and blowers may be incorporated into the above designs to further increase cooling. In one example, the fan 55 may be positioned at the intake of the sidewall 20 having the air passage, as illustrated in
In conjunction with embodiments utilizing a fan 55 to provide additional cooling it is preferred that the fan 55 is in communication with a visible signal 50 attached to the housing 30. The signal 50 being adapted to indicate when the fan 55 is inoperable. In another embodiment of the present invention, the electronic device enclosure may comprise a sensor that measures the temperature within the electronic device enclosure and powers off the heat producing electronic devices when the temperature of the enclosure increases to a point that may damage the electrical devices housed therein.
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims.
