Apparatus and method for cooling electronic systems

Abstract

A method and apparatus for cooling electronic systems includes a field and/or customer replaceable packaged refrigeration module coupled to tubing formed in, or on, the chassis of the electronic system. The field replaceable packaged refrigeration module portion is self-contained and is specifically designed to have physical dimensions similar to those of a standard air-based cooling system, such as a fined heat sink or heat pipe. The coupling of the field replaceable packaged refrigeration module to tubing formed in or on the chassis of the electronic system serves to create a cooling system wherein the temperature of the air surrounding the electronic system is lowered and the chassis of the electronic system itself becomes a refrigerator system for the electronic components therein.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a refrigeration system for cooling electronic systems. More particularly, the invention relates to a method and apparatus for cooling electronic devices that includes a field and/or customer replaceable refrigeration module.

BACKGROUND OF THE INVENTION

[0002] Electronic components, such as microprocessors and other various integrated circuits, have advanced in at least two significant ways. First, feature sizes have moved into the sub-micron range thereby allowing larger numbers of transistors to be formed on a given surface area. This in turn has resulted in greater device and circuit density on the individual chips. Second, in part due to the first advance discussed above, microprocessors have increased dramatically in clock speed. At present microprocessor speeds of 2.5 Gigahertz are coming to market and the 3 and 4 Gigahertz range is rapidly being approached.

[0003] As a result of the advances in device density and microprocessor speed discussed above, heat dissipation, which has always been a problem in the past, is rapidly becoming the limiting factor in microprocessor performance. Consequently, heat dissipation and cooling is now the foremost concern and the major obstacle faced by designers of electronic systems such as computers and servers.

[0004] As noted, heat dissipation has long been recognized as a serious problem limiting the performance of electronic components and systems. In the past, the solutions to the heat dissipation problem have been mostly limited to air-based cooling systems such as fans, with only the most exotic military, scientific and custom electronic systems employing the bulky and costly prior art liquid-based cooling solutions.

[0005] In the prior art, air-based cooling systems, such as fans and other forced air systems, have been the method of choice for several reasons. First, the air-based cooling systems of the prior art were modular and self-contained and were therefore field replaceable with minimal effort using standard tools. Second, air-based cooling systems were compact and simple in both operation and installation, with minimal parts to fail or break and minimal added system complexity. Therefore, prior art air-based cooling systems were reliable.

[0006] In addition, and probably most importantly, in the prior art, air-based cooling systems could reasonably meet the cooling needs of electronic devices and systems so there was little motivation to move to the more complex and potentially problematic liquid-based systems. However, as noted above, due to the advances in microprocessor speeds and device density, air-based cooling systems alone will most likely not be a viable option for cooling electronic systems, such as computers and computer servers, that use the next generation of microprocessors.

[0007] As noted above, another possible prior art cooling system that could potentially provide the level of cooling required by electronic systems using the next generation of microprocessors is liquid-based cooling systems. Prior art liquid-based cooling systems typically used a refrigerant, such as R134A, that was circulated by a compressor. In prior art liquid-based cooling systems the compressor was typically a crankshaft reciprocating compressor or a rotary compressor similar to those used in home refrigerators.

[0008] As noted above, prior art liquid-based cooling systems have far more potential cooling capability than air-based systems. However, in the prior art liquid-based cooling systems, the crankshaft reciprocating or rotary compressors were typically, by electronics industry standards, very large, on the order of tens of inches in diameter, very heavy, on the order of pounds, and often required more power to operate than the entire electronic system they would be charged with cooling. In addition, the size and design of prior art liquid-based cooling systems often required that the major components of the prior art liquid-based cooling system be centrally located, typically remote from the electronic systems to be cooled. Consequently, unlike prior art air-based cooling systems, prior art liquid-based cooling systems were not modular, were not self-contained, and often required special expertise and tools for maintenance and operation.

[0009] In addition, prior art liquid-based cooling systems employed compressors that typically were highly orientation dependent, i.e., they could not operate at angles of more than 30 or 40 degrees. Consequently, prior art liquid based cooling systems were particularly ill suited for the electronics industry that stresses flexibility and often requires orientation independent operation.

[0010] Given that, as discussed above, air-based cooling systems have reached their operational limits when it comes to cooling electronic systems, such as computer servers, there is a growing realization that some other form of cooling system, such as liquid-based cooling systems will need to be adopted by the electronics industry. However, as discussed above, prior art liquid-based cooling systems are far from ideal and, thus far, the industry has not adopted liquid-based cooling in any meaningful way because the problems associated with prior art liquid-based cooling systems are still thought to outweigh the advantages these systems provide in terms of increased cooling capacity.

[0011] What is needed is a method and apparatus for cooling electronic systems that has the cooling capacity and efficiency of a liquid-based cooling system yet has the advantages of being modular, simple, and compact like air-based cooling systems.

SUMMARY OF THE INVENTION

[0012] The present invention is directed to a cooling system for electronic systems that includes a field and/or customer replaceable packaged refrigeration module coupled to tubing formed within, or around, the chassis of the electronic system, or subsystem, to be cooled.

[0013] As noted above, according to the present invention, advances in compressor technology are incorporated in a field replaceable packaged refrigeration module that is coupled to tubing formed in or on the chassis of the electronic system. According to the invention, the field replaceable packaged refrigeration module is self-contained and is specifically designed to have physical dimensions similar to those of a standard air-based cooling system, such as a fan or heat sink.

[0014] In one embodiment of the invention, the coupling of the field replaceable packaged refrigeration module to tubing formed in or on the chassis of the electronic system serves to create a cooling system wherein the temperature of the air surrounding the electronic system is lowered, the entire system is bathed in cool air, and the chassis of the electronic system itself becomes a refrigerator system for the electronic components therein. In one embodiment of the invention, the field replaceable packaged refrigeration module can be operated intermittently, on an as needed basis, to minimize the power used by the system and to minimize the wear and tear of the moving parts. The net result is the ability to manage the ambient temperature of the air within the electronic system chassis.

[0015] The cooling system of the invention is a modified liquid-based cooling system and therefore provides the cooling capacity of a prior art liquid-based cooling systems. However, unlike prior art liquid-based cooling systems, cooling system of the invention is modular and largely self-contained. In addition, according to the invention, the field replaceable packaged refrigeration module is field and/or customer replaceable with minimal effort using standard tools.

[0016] According to the invention, each electronic system, such as a computer server, includes its own the cooling system so that when these electronic systems are grouped into racks, each individual electronic system includes its own self-contained cooling system of the invention. Consequently, the failure of the cooling system for one electronic system does not affect the other systems in the rack and those unaffected systems can continue to operate while the faulty system is repaired. This is in direct contrast to prior art liquid-based systems wherein multiple electronic systems such as computer servers, were coupled to a single prior art cooling system so that if there was a failure anywhere in the cooling system, all the electronic systems were affected and had to be shut down.

[0017] In addition, unlike prior art liquid-based cooling systems, the cooling system of the invention is compact and simple in both operation and installation, with minimal parts to fail or break and minimal added complexity. Therefore, unlike prior art liquid-based cooling systems, the cooling system of the invention is sturdy and reliable.

[0018] In addition, the field replaceable packaged refrigeration module portion of the present invention is specifically designed to be operational in any orientation. Consequently, unlike prior art liquid-based cooling systems, the field replaceable packaged refrigeration module portion of the present invention can be mounted, and operated, at any angle. This makes the cooling system of the present invention particularly well suited for use with electronic systems.

[0019] As discussed briefly above, and in more detail below, the cooling system of the present invention has the cooling capacity of a liquid-based cooling system and yet is modular, compact, simple in design and simple to use, like an air-based cooling system. Consequently, the cooling system of the present invention can readily meet the cooling needs of the next generation of electronic devices and systems.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The refrigeration system of the present invention will be described in the following detailed description, with reference to the accompanying drawings. In the drawings, the same reference numbers are used to denote similar components in the various embodiments.

[0021] FIG. 1 is a functional diagram of a field replaceable packaged refrigeration module designed according to the principles of one embodiment of the invention;

[0022] FIG. 2 is a longitudinal cross sectional view of an exemplary linear compressor that may be used in the field replaceable packaged refrigeration module depicted in FIG. 1 according to the principles of one embodiment of the invention;

[0023] FIG. 3 is a cut-away perspective view a field replaceable packaged refrigeration module positioned within an electronic device chassis according to the principles of one embodiment of the invention.

[0024] FIG. 4A shows an overhead view of one embodiment of a chassis designed according to the principles of the invention to include tubing formed into a tubing loop.

[0025] FIG. 4B shows a perspective view of one embodiment of a chassis designed according to the principles of the invention to include tubing formed into a tubing loop.

[0026] FIG. 4C shows one embodiment of a cooling system designed according to the principles of the invention including a chassis with tubing formed into a tubing loop that is coupled to field replaceable packaged refrigeration module.

[0027] FIG. 5A shows a portion of a typical roll-bond evaporator wall.

[0028] FIG. 5B shows a perspective view of one embodiment of a chassis designed according to the principles of the invention to include roll-bond evaporator walls.

[0029] FIG. 5C shows one embodiment of a cooling system designed according to the principles of the invention including a chassis with roll-bond evaporator walls coupled to a field replaceable packaged refrigeration module.

[0030] FIG. 6 shows one embodiment of a cooling system designed according to the principles of the invention for use in a blade server configuration.

DETAILED DESCRIPTION

[0031] According to the present invention, advances in compressor technology (312 in FIG. 3) are incorporated in a field replaceable packaged refrigeration module (300 in FIGS. 3, 4C and 5C) that is coupled to tubing (401 in FIG. 4C and 551 in FIG. 5C) formed in, or on, the chassis (301 in FIG. 3, 400 in FIGS. 4A, 4B and 4C and 550 in FIGS. 5B and 5C) of the electronic system to be cooled. According to the invention, the field replaceable packaged refrigeration module is self-contained and is specifically designed to have physical dimensions similar to those of a standard air-based cooling system, such as a fan or heat sink.

[0032] In one embodiment of the invention, the coupling of the field replaceable packaged refrigeration module to tubing formed in, or on, the chassis of the electronic system serves to create a cooling system wherein the temperature of the air surrounding the electronic system is lowered, the entire system is bathed in cool air, and the chassis of the electronic system itself becomes a refrigerator system for the electronic components therein.

[0033] FIG. 1 is a functional diagram of a field replaceable packaged refrigeration module 10 designed according to one embodiment of the invention. Referring to FIG. 1, field replaceable packaged refrigeration module 10 includes a compressor 12, a condenser 14, an optional receiver 16, an expansion device 18 and an evaporator 20, all of which are connected together in refrigeration loop 22 through which a working fluid, such as water or ethanol, is circulated. As explained in more detail below, according to one embodiment of the invention, evaporator 20 is constructed either as tubing formed within the chassis of an electronic system to be cooled or as roll-bond walls of the chassis of an electronic system to be cooled.

[0034] As is well understood by those of ordinary skill in the art, compressor 12 compresses the refrigerant (not shown) into a high-pressure, high temperature liquid that is then conveyed to condenser 14. At condenser 14, the refrigerant is allowed to cool before being conveyed to receiver 16. From receiver 16, the refrigerant passes through expansion device 18, which may be, for example, a capillary tube, and into evaporator 20. The liquid refrigerant evaporates in evaporator 20 and in the process absorbs heat to produce the desired cooling effect. From evaporator 20 the refrigerant is drawn back into compressor 12 to begin another cycle through refrigeration loop 22.

[0035] In accordance with the present invention, compressor 12 is one of several new generation compressors that are relatively small, on the order of 2.0 inches in diameter and 3 to 4 inches long. In one embodiment of the invention, compressor 12 is less than 1.7 inches in diameter and less than 4 inches long. One example of this new generation of compressors is the relatively new linear compressor now being used in the more standard refrigeration, i.e., non-electronics, industry. In one embodiment of the invention, compressor 12 is a linear compressor whose operation is controlled by drive circuit 26.

[0036] As discussed in more detail with respect to FIG. 2, a linear compressor is a positive displacement compressor having one or more free floating pistons that are driven directly by a linear motor. Thus, a linear compressor differs from a conventional reciprocating and rotary compressor where the pistons are driven through a crankshaft linkage, or by a rotary motor through a mechanical linkage, respectively. Since the capacity of any compressor is directly related to the size and displacement of the pistons, a linear compressor can typically be made smaller than a crankshaft reciprocating or rotary compressor but can maintain the same capacity since the displacement of the pistons is not dependent on the size of a mechanical linkage. In addition, since a linear compressor usually comprises fewer moving parts than a crankshaft reciprocating or rotary compressor, the linear compressor is typically quieter than a crankshaft reciprocating or rotary compressor. Furthermore, since the pistons of a double-piston linear compressor move in opposition to one another, the reaction forces of the pistons will cancel each other out and the vibrations that are commonly experienced with crankshaft reciprocating or rotary compressors will consequently be suppressed. Consequently, linear compressors offer many advantages over a crankshaft reciprocating compressor or a rotary compressor for application as compressor 12 in field replaceable packaged refrigeration module 10.

[0037] The linear compressors suitable for use as compressor 12 in field replaceable packaged refrigeration module 10 can be any of a variety of single, double or multiple-piston linear compressors that are known in the art. For example, in one embodiment of the invention, linear compressor 12 is a single-piston linear compressor of the type disclosed in U.S. Pat. No. 5,993,178, which is hereby incorporated herein by reference, or a double-piston linear compressor of the type disclosed in U.S. Pat. No. 6,089,836 or U.S. Pat. No. 6,398,52, all of which are hereby incorporated herein by reference.

[0038] Referring to FIG. 2, an exemplary linear compressor 120, suitable for use as compressor 12 in FIG. 1, comprises a housing 28, first and second cylinders 30, 32 which are connected to, or formed integrally with, housing 28, and first and second pistons 34, 36 which are slidably received within first and second cylinders 30, 32, respectively. The ends of housing 28 are, in one embodiment, hermetically sealed, such as by end plates 38. In addition, each cylinder 30, 32 has an axial centerline CL that is, in one embodiment, coaxial with that of the other cylinder. Furthermore, housing 28 is, in one embodiment, constructed of a magnetically permeable material, such as stainless steel, and pistons 34, 36 are optimally constructed of a magnetically indifferent material, such as plastic or ceramic.

[0039] In the embodiment of exemplary linear compressor 120 shown in FIG. 2, each piston 34, 36 is driven within its respective cylinder 30, 32 by linear motor 40. Each motor 40 includes a ring-shaped permanent magnet 42 and an associated electrical coil 44. In the embodiment of an exemplary linear compressor 120 shown in FIG. 2, magnet 42 is mounted within housing 28 and coil 44 is wound upon a portion of piston 34, 36. In one embodiment, magnet 42 is radially charged, and each motor 40 includes a cylindrical core 46 mounted within housing 28 adjacent magnet 42 to direct the flux lines (not shown) from magnet 42 across coil 44. In one embodiment, coil 44 is energized by an AC current, from drive circuit 26 (FIG. 1), over a corresponding lead wire (not shown). In one embodiment of the invention, drive circuit 26 is programmed such that, when the AC current is applied to coils 44 (FIG. 2), pistons 34, 36 will reciprocate toward and away from each other along the axial centerline CL of cylinders 30, 32. In another embodiment, DC current is applied. In one embodiment, spring 48, or similar means, may be connected between each piston 34, 36 and adjacent end plate 38 to aid in matching the natural frequency of piston 34, 36 to the frequency of the current from drive circuit 26 (FIG. 1).

[0040] The embodiment of an exemplary linear compressor 120 shown in FIG. 2 also includes a compression chamber 50 located within cylinders 30, 32, between pistons 34, 36. During the expansion portion of each operating cycle of linear compressor 120, motors 40 will move pistons 34, 36 away from each other. This will cause the then gaseous refrigerant within evaporator 20 (FIG. 1) to be drawn into compression chamber 50 (FIG. 2), through an inlet port 52 in housing 28. During the successive compression portion of the operating cycle of exemplary linear compressor 120, motors 40 will move pistons 34, 36 toward each other. Pistons 34, 36 will consequently compress the then gaseous refrigerant within compression chamber 50 into a liquid and eject it into condenser 14 (FIG. 1), through an outlet port 54 (FIG. 2) in housing 28. In one embodiment, suitable check valves 56, 58 are provided in inlet and outlet ports 52, 54, respectively, to control the flow of refrigerant through inlet and outlet ports 52, 54 during the expansion and compression portions of each operating cycle.

[0041] While a specific embodiment of a field replaceable packaged refrigeration module 10 is discussed above that includes exemplary linear compressor 120, those of skill in the art will recognize that the choice of a linear compressor, or any particular compressor, for use as compressor 12 in the discussion above was made for illustration simplicity and to avoid detracting from the invention by describing multiple specific embodiments at one time. In other embodiments of the invention appropriately sized rotary compressor, or other type of compressor, can be used as compressor 12. For instance, in various embodiments of the invention, compressor 12 can be: a reciprocating compressor; a Swash-plate compressor; a rolling piston compressor; a scroll compressor; a rotary vane compressor; a screw compressor; an aerodynamic-turbo compressor; an aerodynamic-axial compressor; or any other reciprocating, volumetric or aerodynamic compressor known in the art, or developed after this application is filed. Consequently, the present invention should not be read as being limited the particular embodiments discussed above using linear, or any specific, compressor types.

[0042] Consequently, the present invention should not be read as being limited the particular embodiments discussed above using linear, or any specific, compressor types.

[0043] According to the principles of the invention, field replaceable packaged refrigeration module 10 is mounted in the chassis of an electronic system for use in cooling the electronic system. For example, it is often the case that many computer servers are housed within an enclosure/cabinet or “rack unit”. According to the invention, each computer server would include it own cooling system and field replaceable packaged refrigeration module 10.

[0044] In accordance with one industry standard, each rack unit has a height of only 1.75 inches. This fact makes use of prior art liquid-based cooling systems extremely difficult, if not impossible, and makes the extensive, and potentially disastrous, plumbing, discussed above, a system requirement. In contrast, a single, or even multiple, field replaceable packaged refrigeration modules 10, designed according to the principles of the invention, can be positioned within the housing of the server, and/or on the rack units, to directly cool the air surrounding the integrated circuits that are located within or on the rack units.

[0045] FIG. 3 is a cut-away view a field replaceable packaged refrigeration module 300 positioned within an electronic device chassis 301. As discussed above, in accordance with one embodiment of the invention, field replaceable packaged refrigeration module 300 is sized such that, when positioned as shown in FIG. 3, field replaceable packaged refrigeration module 300 will fit within a rack unit of a conventional computer server or a telecommunications rack.

[0046] In one embodiment of the invention, field replaceable packaged refrigeration module 300 has a length 303 (FIG. 3) of approximately six inches, a width 307 of approximately four inches, and a height 305 of approximately one and three-quarter inches. In another embodiment of the invention, field replaceable packaged refrigeration module 300 has a length 303 of approximately five inches, a width 307 of approximately four inches, and a height 305 of approximately one and three-quarter inches. Of course, those of skill in the art will recognize that length 303, width 307 and height 305 of field replaceable packaged refrigeration module 300 can be varied to meet the needs of specific applications.

[0047] As shown in FIG. 3, in one embodiment of the invention, field replaceable packaged refrigeration module 300 includes a housing 366 which has generally open front and back sides 368, 370, a conventional air-cooled condenser 314, which is mounted within housing 366 between open front and back sides 368, 370, and a compressor 312 which is connected to housing 366. As discussed above, in one embodiment of the invention, compressor 312 is a linear compressor driven by a drive circuit (not shown) in a manner similar to that discussed above. As discussed in more detail below, in another embodiment of the invention, field replaceable packaged refrigeration module 300 is coupled to tubing formed on (FIG. 4C) or in (FIG. 5C) electronic device chassis 301.

[0048] In one embodiment of the invention, condenser 314 is cooled by a flow of air from a system fan (not shown) that is mounted in chassis 301. In addition, in one embodiment of the invention, field replaceable packaged refrigeration module 300 is connected to chassis 301 with a number of standoffs 374 and screws 376.

[0049] As noted above, according to the present invention, field replaceable packaged refrigeration module 300 is coupled to tubing formed in, or on, chassis 301 of the electronic system. The coupling of field replaceable packaged refrigeration module 300 to tubing formed in, or on, chassis 301 of the electronic system serves to create a cooling system wherein the evaporator of the cooling system is the tubing loop formed in or on chassis 301 and temperature of the air surrounding the electronic system is lowered, the entire system is bathed in cool air, and chassis 301 of the electronic system itself becomes a refrigerator system for the electronic components therein.

[0050] FIG. 4A shows an overhead view of one embodiment of a chassis 400 designed according to the invention to include tubing 401 formed into tubing loop 403. According to the invention, tubing loop 403 acts as the evaporator for the cooling system of the invention. FIG. 4B shows a perspective view of chassis 400 and tubing 401 formed into tubing loop 403. According to the invention, tubing 401 making up tubing loop 403 can be any one of a variety of materials such as various metals and/or synthetic and natural materials known in the art. In this embodiment of the invention, tubing 401 is attached to chassis 400 using any suitable method such as glues, solder, mechanical attachment means, or even integral formation.

[0051] Those of skill in the art will further recognize that the amount of tubing 401, and the positioning of tubing 401, can be varied to meet the cooling needs of the particular electronic system being cooling. For instance, tubing 401 can be switched back and forth to form coils or multiple tub lengths can be run parallel to each other to increase tubing 401 surface area and increase the cooling capacity of tubing loop 403.

[0052] FIG. 4C shows cooling system 450 of the invention including chassis 400 with tubing 401 formed into tubing loop 403 that is coupled to field replaceable packaged refrigeration module 300 by connection tube 451. Also shown in FIG. 4C are condenser 314 and compressor 312 (discussed in more detail above with respect to FIG. 3) and tubing 453 of field replaceable packaged refrigeration module 300.

[0053] During the normal operation of cooling system 450 of the invention, relatively high-pressure liquid refrigerant from compressor 312 is conveyed through tubing 453 to condenser 314. In one embodiment of the invention, the high-pressure liquid refrigerant is cooled in condenser 314 by the flow of air from a system fan (not shown). The refrigerant is then conveyed through connection tube 451 to tubing loop 403 that acts as an evaporator. The refrigerant evaporates in tubing loop 403 and in the process absorbs heat and cools the air within chassis 400. The now gaseous refrigerant is then drawn back into compressor 312 through conduit 480. This cycle is then repeated as required to produce a desired cooling effect for the electronic system (not shown) housed in chassis 400. Consequently, using the method and apparatus of the invention, the temperature of the air surrounding the electronic system (not shown) housed in chassis 400 is lowered, the entire system is bathed in cool air, and chassis 400 becomes a refrigerator system for the electronic components therein (not shown).

[0054] In another embodiment of the invention, the walls of the electronic system chassis itself are formed as roll-bond evaporators. Roll-bond evaporator walls are typically formed by pressing two or more sheets of wall material, typically metal, such that within the wall there exists two areas or compartments, typically one for holding a refrigerant and one with no refrigerant.

[0055] FIG. 5A shows a portion of a typical roll-bond evaporator wall 500. Portion of roll-bond evaporator wall 500 includes: first outer wall surface 501, that would typically be exposed to the air outside the chassis; second outer wall surface 503, that would typically be exposed to the air inside the chassis; first inner wall 505; and second inner wall 507. First inner wall 505 and second inner wall 507 define area 509 that is physically isolated from area 511 by first inner wall 505 and second inner wall 507. In a typical roll-bond evaporator wall, area 509 would contain refrigerant (not shown) and area 511 would not.

[0056] FIG. 5B shows a perspective cut-away view of one embodiment of a chassis 550 designed according to the principles of the invention to include roll-bond evaporator walls 551 formed into an evaporator loop 553.

[0057] FIG. 5C shows one embodiment of a cooling system 580 designed according to the principles of the invention including chassis 550 with roll-bonded evaporator walls 551 coupled to field replaceable packaged refrigeration module 300 by connection tube 555 and connection port 557. Also shown in FIG. 5C are condenser 314 and compressor 312 (discussed in more detail above with respect to FIG. 3) and tubing 559 of field replaceable packaged refrigeration module 300.

[0058] During the normal operation of cooling system 580 of the invention, relatively high-pressure liquid refrigerant from compressor 312 is conveyed through tubing 559 to condenser 314. In one embodiment of the invention, the high-pressure liquid refrigerant is cooled in condenser 314 by the flow of air from a system fan (not shown). The refrigerant is then conveyed through a connection tube 555 to roll-bond evaporator wall 551 and evaporator loop 553 that acts as an evaporator. The refrigerant evaporates in evaporator loop 553 and in the process absorbs heat and cools the air within chassis 550. The now gaseous refrigerant is then drawn back into compressor 312 through conduit 561. This cycle is then repeated as required to produce a desired cooling effect for the electronic system (not shown) housed in chassis 550. Consequently, using the method and apparatus of the invention, the temperature of the air surrounding the electronic system (not shown) housed in chassis 550 is lowered, the entire system is bathed in cool air, and chassis 550 becomes a refrigerator system for the electronic components therein (not shown).

[0059] The cooling system of the invention can also be used in blade server applications to cool either individual blade servers or groups of blade servers. FIG. 6 shows one embodiment of a blade-cooling system 601 designed according to the principles of the present invention for use in a blade server frame 603 to cool a blade server 605. As shown in FIG. 6, blade-cooling system 601 includes: condenser 614; compressor 612; evaporator 607; fan 609; and connecting tubes 651, 653 and 655. As with the embodiments of the invention discussed above, in one embodiment of blade-cooling system 601, compressor 612 is a linear compressor driven by a drive circuit (not shown) in a manner similar to that discussed above.

[0060] According to the invention, blade-cooling system 601 is self-contained within a blade-cooling system housing 611, also called chassis 611. In one embodiment of the invention chassis 611 has dimensions approximately identical to those of a blade server 605 so that blade-cooling system 601 fits into a blade server station, such as blade server stations 613 and 615 in FIG. 6, within blade server frame 603. In this way, individual blade-cooling cooling system s 601 can be placed directly next to the blade server 605 they are intended to cool and the blade-cooling systems 601 can be readily replaced in the field on a “plug and play” basis.

[0061] During the normal operation of blade-cooling system 601 of the invention, relatively high-pressure liquid refrigerant from compressor 612 is conveyed through tubing 653 to condenser 614. In one embodiment of the invention, the high-pressure liquid refrigerant is cooled in condenser 614 by the flow of air from fan 609. The refrigerant is then conveyed through connection tube 655 to evaporator 607. Evaporator 607 is then placed in thermal contact with blade server 605 within blade server frame 603. The refrigerant evaporates in evaporator 607, and in the process absorbs heat and cools blade server 605 and/or the air surrounding blade server 605. The now gaseous refrigerant is then drawn back into compressor 612 through tubing 651. This cycle is then repeated as required to produce a desired cooling effect for blade server 605 housed in blade server frame 603.

[0062] As shown above, according to the present invention, advances in compressor technology are incorporated in a field replaceable packaged refrigeration module that is coupled to tubing formed in, or on, the chassis of the electronic system to be cooled. According to the invention, the field replaceable packaged refrigeration module is self-contained and is specifically designed to have physical dimensions similar to those of a standard air-based cooling system, such as a fan or heat sink.

[0063] In one embodiment of the invention, the coupling of the field replaceable packaged refrigeration module to tubing formed in, or on, the chassis of the electronic system serves to create a cooling system wherein the temperature of the air surrounding the electronic system is lowered, the entire system is bathed in cool air, and the chassis of the electronic system itself becomes a refrigerator system for the electronic components therein. In one embodiment of the invention, the field replaceable packaged refrigeration module can be operated intermittently, on an as needed basis, to minimize the power used by the system and to minimize the wear and tear of the moving parts. The net result is the ability to manage the ambient temperature of the air within the electronic system.

[0064] The cooling system of the invention is a modified liquid-based cooling system and therefore provides the cooling capacity of a prior art liquid-based cooling systems. However, unlike prior art liquid-based cooling systems, cooling system of the invention is modular and largely self-contained. In addition, according to the invention the field replaceable packaged refrigeration module is field and/or customer replaceable with minimal effort using standard tools.

[0065] According to the invention, each electronic system, such as a computer server, includes its own the cooling system of the invention so that when these electronic systems are grouped into racks, each individual electronic system includes its own self-contained cooling system. Consequently, the failure of the cooling system for one electronic system does not affect the other systems in the rack and those unaffected systems can continue to operate while the faulty system is repaired. This is in direct contrast to prior art liquid-based systems wherein multiple electronic systems such as computer servers, were coupled to a single prior art cooling system so that if there was a failure anywhere in the cooling system, all the electronic systems were affected and had to be shut down.

[0066] In addition, unlike prior art liquid-based cooling systems, the cooling system of the invention is compact and simple in both operation and installation, with minimal parts to fail or break and minimal added complexity. Therefore, unlike prior art liquid-based cooling systems, the cooling system of the invention is sturdy and reliable.

[0067] In addition, the field replaceable packaged refrigeration module portion of the present invention is specifically designed to be operational in any orientation. Consequently, unlike prior art liquid-based cooling systems, the field replaceable packaged refrigeration module portion of the present invention can be mounted, and operated, at any angle. This makes the cooling system of the present invention particularly well suited for use with electronic systems.

[0068] As discussed above, the cooling system of the present invention has the cooling capacity of a liquid-based cooling system and yet is modular, compact, simple in design and simple to use, like an air-based cooling system. Consequently, the cooling system of the present invention can readily meet the cooling needs of the next generation of electronic devices and systems.

[0069] It should be recognized that, while the present invention has been described in relation to the specific embodiments thereof discussed above, those skilled in the art might develop a wide variation of structural and operational details without departing from the principles of the invention.

[0070] As one example, the choice of a linear compressor, or any particular linear compressor, for use as compressor 312 in the discussion above was made for illustration simplicity and to avoid detracting from the invention by describing multiple specific embodiments at one time. In other embodiments of the invention, appropriately sized rotary compressors, or other compressors, can be used as compressor 312. For instance, in various embodiments of the invention, compressor 312 can be: a reciprocating compressor; a swash-plate compressor; a rolling piston compressor; a scroll compressor; a rotary vane compressor; a screw compressor; an aerodynamic-turbo compressor; an aerodynamic-axial compressor; or any other reciprocating, volumetric or aerodynamic compressor known in the art, or developed after this application is filed. Consequently, the present invention should not be read as being limited the particular embodiments discussed above using linear, or any specific, compressor types.

[0071] As another example, specific dimensions were discussed above as examples of possible values for the length, width and height 305 of field replaceable packaged refrigeration module 300. Those of skill in the art will recognize that length 303, width 307 and height 305 of field replaceable packaged refrigeration module 300 can be varied for specific applications and that the present invention should not be read as being limited the particular embodiments discussed above with the particular dimensions discussed by way of illustration.

Claims

1. A cooling system for an electronic device comprising:

an electronic device chassis, said electronic device chassis comprising tubing formed into a tubing loop within said electronic device chassis;

a packaged refrigeration module, said packaged refrigeration module comprising:

a packaged refrigeration module housing;

refrigerant;

a compressor;

a condenser; and

an expansion device; wherein,

said compressor, said condenser, and said expansion device of said packaged refrigeration module and said tubing loop of said electronic device chassis are coupled together in a refrigeration loop within said electronic device chassis.

2. The cooling system for an electronic device of claim 1; wherein,

said packaged refrigeration module has a width of approximately 4 inches, a length of approximately 5 inches and a height of approximately 1.75 inches.

3. The cooling system for an electronic device of claim 1; wherein,

said compressor is a single piston linear compressor.

4. The cooling system for an electronic device of claim 1; wherein,

said compressor is a dual-piston linear compressor.

5. The cooling system for an electronic device of claim 1; wherein,

said compressor is a multi-piston linear compressor.

6. The cooling system for an electronic device of claim 1; wherein,

said compressor is a rotary compressor.

7. The cooling system for an electronic device of claim 1; wherein,

said compressor is a reciprocating compressor.

8. The cooling system for an electronic device of claim 1; wherein,

said compressor is a rolling piston compressor.

9. The cooling system for an electronic device of claim 1; wherein,

said compressor is a rotary vane compressor.

10. The cooling system for an electronic device of claim 1; wherein,

said compressor is a screw compressor.

11. The cooling system for an electronic device of claim 1; wherein,

said compressor is a swash-plate compressor.

12. The cooling system for an electronic device of claim 1; wherein,

said compressor is a scroll compressor.

13. A cooling system for an electronic device comprising:

an electronic device chassis, said electronic device chassis comprising at least one roll-bond evaporator panel forming at least a portion of said electronic device chassis;

a packaged refrigeration module, said packaged refrigeration module comprising:

a packaged refrigeration module housing;

refrigerant;

a compressor;

a condenser; and

an expansion device; wherein,

said compressor, said condenser, and said expansion device of said packaged refrigeration module and said at least one roll-bond evaporator panel forming at least a portion of said electronic device chassis are coupled together in a refrigeration loop within said electronic device chassis.

14. The cooling system for an electronic device of claim 13; wherein,

said packaged refrigeration module has a width of approximately 4 inches, a length of approximately 5 inches and a height of approximately 1.75 inches.

15. The cooling system for an electronic device of claim 13; wherein,

said compressor is a single piston linear compressor.

16. The cooling system for an electronic device of claim 13; wherein,

said compressor is a dual-piston linear compressor.

17. The cooling system for an electronic device of claim 13; wherein,

said compressor is a multi-piston linear compressor.

18. The cooling system for an electronic device of claim 13; wherein,

said compressor is a rotary compressor.

19. The cooling system for an electronic device of claim 13; wherein,

said compressor is a reciprocating compressor.

20. The cooling system for an electronic device of claim 13; wherein,

said compressor is a rolling piston compressor.

21. The cooling system for an electronic device of claim 13; wherein,

said compressor is a rotary vane compressor.

22. The cooling system for an electronic device of claim 13; wherein,

said compressor is a screw compressor.

23. The cooling system for an electronic device of claim 13; wherein,

said compressor is a swash-plate compressor.

24. The cooling system for an electronic device of claim 13; wherein,

said compressor is a scroll compressor.

25. A blade-cooling system, said blade-cooling system comprising:

a blade-cooling system housing;

refrigerant;

a compressor;

a condenser;

an expansion device; and

an evaporator; wherein,

said compressor, said condenser, and said expansion device and said evaporator of said blade-cooling system are coupled together in a refrigeration loop within said blade-cooling system housing; further wherein;

said blade-cooling system housing is sized such that said blade-cooling system fits within a blade server station in a blade server frame.

26. The blade-cooling system of claim 25; wherein,

said blade-cooling system housing has a width of less than three inches, a length of less than approximately six inches and a height of less than six inches.

27. The blade-cooling system of claim 25; wherein,

said compressor is a single piston linear compressor.

28. The blade cooling of claim 25; wherein,

said compressor is a dual-piston linear compressor.

29. The blade cooling of claim 25; wherein,

said compressor is a multi-piston linear compressor.

30. The blade cooling of claim 25; wherein,

said compressor is a rotary compressor.

31. The blade-cooling system of claim 25; wherein,

said compressor is a reciprocating compressor.

32. The blade cooling of claim 25; wherein,

said compressor is a rolling piston compressor.

33. The blade cooling of claim 25; wherein,

said compressor is a rotary vane compressor.

34. The blade-cooling system of claim 25; wherein,

said compressor is a screw compressor.

35. The blade-cooling system of claim 25; wherein,

said compressor is a swash-plate compressor.

36. The blade-cooling system of claim 25; wherein,

said compressor is a scroll compressor.