# Patent

## Title
Device and methodology for the removal of heat from an equipment rack by means of heat exchangers mounted to a door

## Abstract

A cooling door assembly includes a frame and a cooling door coupled to the frame. The cooling door includes one or more heat exchangers. The frame is configured to mount to the back of a server rack or other electronics enclosure in such a manner that the cooling door opens to allow access to the electronics servers within the server rack while maintaining a fluidic connection to an external cooling system. The frame is coupled to the external cooling system and the cooling door includes swivel joints configured to provide a fluid path between the cooling door and the frame. In this manner, the frame remains in a fixed position, while the cooling door is configured to rotate relative to the frame so as to open and close, while maintaining the fluid path through the swivel joint.

## Background
RELATED APPLICATIONS
This application claims priority of U.S. provisional application Ser. No. 61/068,891, filed Mar. 10, 2008, and entitled “Fan Tray for Supplemental Air Flow”, by these same inventors. This application incorporates U.S. provisional application Ser. No. 61/068,891 in its entirety by reference.


FIELD OF THE INVENTION
The invention relates to a method of and apparatus for cooling a heat producing device in general, and specifically, to a method of and apparatus for cooling server applications using fluid-based cooling systems.
BACKGROUND OF THE INVENTION
Cooling of high performance integrated circuits with high heat dissipation is presenting significant challenge in the electronics cooling arena. Conventional cooling with heat pipes and fan mounted heat sinks are not adequate for cooling chips with ever increasing wattage requirements, including those exceeding 100 W.
Electronics servers, such as blade servers and rack servers, are being used in increasing numbers due to the higher processor performance per unit volume one can achieve. However, the high density of integrated circuits also leads to high thermal density, which is beyond the capability of conventional air-cooling methods.
A particular problem with cooling integrated circuits on electronics servers is that multiple electronics servers are typically mounted in close quarters within a server chassis. In such configurations, electronics servers are separated by a limited amount of space, thereby reducing the dimensions within which to provide an adequate cooling solution. Typically, stacking of electronics servers does not provide the mounting of large fans and heat sinks for each electronics server. Often electronics server stacks within a single server chassis are cooled with one or more fans, one or more heat sinks, or a combination of both. Using this configuration, the integrated circuits on each electronics server are cooled using the heat sink and the large fan that blows air over the heat sink, or simply by blowing air directly over the electronics servers. However, considering the limited free space surrounding the stacked electronics servers within the server chassis, the amount of air available for cooling the integrated circuits is limited.
As data centers continue to increase their computer density, electronics servers are being deployed more frequently. Fully populated electronics servers significantly increase rack heat production. This requires supplemental cooling beyond what the Computer Room Air Conditioning (CRAC) units can provide. Supplemental cooling systems may include fans, pumps, and heat exchangers located outside the back end of the electronics server to decrease the air temperature exiting the electronics server. The heat exchangers in these supplemental cooling systems are supplied with pumped coolants, water, or refrigerants. While these supplemental cooling systems can take advantage of efficiency gained by economies of scale, they still require additional fans. It is desirable to take advantage of the existing fans in the electronics server.
Some supplemental cooling systems are configured as a “cooling door” that is attached to the back of a server rack. Supply and return hoses extend into the data center floor through a large opening. This large opening is required to provide clearance so that additional hose length can be pulled out of the floor as the door is opened and slid back into the floor when the door is closed. The space in the floor is usually under a positive pressure with air being supplied from CRAC units. The floor opening can cause a loss in efficiency as some amount of chilled air escapes from under the floor through this opening. Further, pulling additional hose out of and sliding the hose back into the opening is a tedious, and sometimes difficult, activity for the user opening and closing the cooling door. Still further, since the hose is connected to the cooling door as the door is opened and closed, physical strain is placed on the cooling door and hose connection, which creates wear and tear on, and possibly damage to, the connection components.
SUMMARY OF THE INVENTION
Cooling systems of the present invention are directed to a cooling door assembly including one or more heat exchangers. The cooling door assembly includes a frame and a cooling door coupled to the frame. The frame is configured to mount to a server rack, cabinet, or other electronics enclosure in such a manner that the cooling door opens to allow access to the electronics servers within the server rack while maintaining a fluidic connection to an external cooling system. The cooling door and frame are mounted together to form a stand-alone cooling door assembly with input and output plumbing to the external cooling system. There is no plumbing within the server rack and therefore the cooling door assembly does not include plumbing into and out of the server cabinet. As such, there is no need to modify an existing server cabinet for plumbing when adding the cooling door assembly to the server cabinet. The cooling door assembly is configured as a retrofit assembly to the server cabinet. The frame of the cooling door assembly can be designed to mate to different sized server cabinets. The frame is coupled to the external cooling system, and the cooling door includes one or more swivel joints configured to provide a fluid path between the cooling door and the frame. In this manner, the frame remains in a fixed position, while the cooling door is configured to rotate relative to the frame so as to open and close, while maintaining the fluid path through each swivel joint.
The cooling door assembly does not include hoses that are pulled in and out of the floor when the cooling door is opened and closed. The cooling door assembly can be hard plumbed or virtually hard plumbed since the use of highly flexible hoses is no longer used as a connection to an external cooling system. In addition, since highly flexible hoses are no longer used, metal tubes and pipes can be used, which allows for the use of refrigerants, such as R-134. With the use of refrigerant, an increase in cooling capacity can be obtained.
In some embodiments, the frame includes mounting blocks that are coupled with external fluid connectors for supplying and returning coolant from an external source, such as an external cooling system. The external cooling system can include a cooling tower, a chiller, or other secondary cooling loop including a heat exchanger used to cool the coolant exiting the cooling door assembly. Water, refrigerant, or any other coolant is used. In some embodiments, the coolant is a two-phase coolant. In other embodiments, the coolant is a single-phase coolant. Fluid flow rate controls can be included to optimize the coolant flow rate within the cooling door assembly. In some embodiments, the fluid flow rate controls are implemented using flow rate valves under the control of a control module.
The mounting blocks, including a supply mounting block and a return mounting black, are each configured using one of a number of various connection types, and with one or more input/output openings. For example, the supply mounting block can have 1, 2, or more input connections depending on the amount of coolant that is required. The same can be done on the return mounting block. The connection types can be a flare fitting, a threaded connection, or other common types of connection. In a two-phase system, there is an extra pressure drop that occurs when a fluid is in the gas phase. In this case, the cooling door assembly can be configured to have a supply mounting block with a single input coupled to a single coolant supply line, and a return mounting block with multiple outputs coupled to multiple return lines, for example. If the connection type has too high a fluid pressure drop, then the mounting blocks can be configured with multiple supply or return connections. The frame including the mounting blocks is designed such that the mounting blocks are interchangeable so that different connection types and number of connections are readily available by simply switching mounting blocks.
In some embodiments, both the supply mounting block and the return mounting block are located at the top of the frame. In other embodiments, the mounting blocks are located at the bottom of the frame, such as when a chilled water loop is used. It is also possible to position the mounting blocks in a configuration such that one is at the top and one is at the bottom. In some configurations, one or more mounting blocks are located at the top of the frame and one or more mounting blocks are located at the bottom of the frame. This may be the case if the system is coupled to one or more different cooling loops in order to provide redundancy in case of failure. The mounting blocks are designed to add minimal pressure drop to the system.
The mounting blocks are fixed in position relative to the frame. The cooling door is rotatably coupled to the frame through the use of coolant swivel joints, also referred to as rotary unions. The swivel joint allows fluid to pass through a hinge that allows rotation to occur and also provides a fluid path between the fixed mounting block and the rotating cooling door. A swivel joint is coupled to at least one of the mounting blocks. In some embodiments, the swivel joint is configured with a single fluid path. In other embodiments, the swivel joint is configured with multiple fluid paths. Multiple load-bearing mechanical hinges are used to attach the cooling door to the frame.
A heat exchanger system on the cooling door is configured to transfer heat from the air passing over the heat exchanger surfaces into the coolant flowing within the heat exchangers. The heat exchangers are designed with a low airflow impedance. This allows the existing air movers in the electronics enclosure to be used to provide the air flow for cooling. Optionally, a separate fan tray is attached to the cooling door to provide better air flow.
In some embodiments, the heat exchangers are made of a micro-tube construction with attached air fins or of a tube-fin type of design. The cooling door can include a single large heat exchanging panel or a group of heat exchanging panels attached in parallel or series. Separate heat exchanging panels are more manageable to construct and provide better control of fluid distribution. In some embodiments, each heat exchanging panel has its own separate flow regulator or valve for regulating the amount of coolant flow within the panel. The regulators or valves can be set so that each panel gets equal coolant flow or each panel gets a different amount of coolant. In other embodiments, a flow control regulator is positioned at any point on the fluid supply side of the heat exchanging panels, such as in a frame supply line or a cooling door supply line.
The system of heat exchanging panels can be oriented so that coolant flow is either in the horizontal orientation or the vertical orientation. When the heat exchanging panels are arranged in the vertical orientation, coolant enters at the bottom-most heat exchanging panel and flows upward. This configuration ensures that as much fluid as possible is in the cooling door. Separate panels also enable one or more windows to be included in the cooling door. Heat exchangers are difficult to see through. By breaking up the cooling door into a series of panels, one or more windows can be added in between the heat exchangers so that one can see into the enclosure. This is particularly useful to see warning lights. Each window is covered with a transparent material so as to prevent airflow through the window opening.
The multiple heat exchanging panels are coupled to each other either in series, in parallel, or a series-parallel combination via mounting piping to make a rigid assembly. In order for the cooling door to properly open and close without binding, the mechanical hinges and the swivel joints optimally have all their axis of rotation co-linear. If the axis are not collinear, then some amount of flex is required to prevent binding. To accomplish this, flexible tubing is used in key areas on the cooling door. This allows for some flex and misalignment to be taken up. Flexible tubing or flexible piping generally has better bending flex than it has the ability to torsionally flex (twist) or axially flex (longer or shorter.) To overcome this, sections of flexible piping are assembled together with a non-flexible right-angle bend. The non-flexible right-angle bend allows one arm to move axially because the movement is taken up be a bend in flexible tubing coupled to the other arm. Both flexible members allow flex in three-dimensions. An alternative way of accomplishing this is by using a four-bar linkage. The four bar linkage allows for movement of the swivel joint without changing the rotational orientation of the swivel joint.
Other features and advantages of the present invention will become apparent after reviewing the detailed description of the embodiments set forth below.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cooling door assembly coupled to an electronics enclosure according to an embodiment of the present invention.
FIG. 2 illustrates an enlarged portion of the cooling door assembly of FIG. 1.
FIG. 3 illustrates a cooling door assembly coupled to the electronics enclosure according to another embodiment of the present invention.
FIG. 4 illustrates a cooling door assembly coupled to the electronics enclosure according to yet another embodiment of the present invention.
FIG. 5 illustrates a cooling door assembly configured according to yet another embodiment of the present invention.
FIG. 6 illustrates an enlarged top portion of the cooling door assembly of FIG. 5 with a portion of the frame paneling removed.
FIG. 7 illustrates an enlarged bottom portion of the cooling door assembly of FIG. 5 with a portion of the frame paneling removed.



The present invention is described relative to the several views of the drawings. Where appropriate and only where identical elements are disclosed and shown in more than one drawing, the same reference numeral will be used to represent such identical elements.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Reference will now be made in detail to the embodiments of the cooling system of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the embodiments below, it will be understood that they are not intended to limit the invention to these embodiments and examples. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to more fully illustrate the present invention. However, it will be apparent to one of ordinary skill in the prior art that the present invention may be practiced without these specific details. In other instances, well-known methods and procedures, components and processes haven not been described in detail so as not to unnecessarily obscure aspects of the present invention.
Embodiments of the present invention are directed to a cooling system that transfers heat generated by one or more electronics servers within a server rack. The cooling system described herein can be applied to any electronics sub-system that is mounted to a backplane, including but not limited to, a blade server and a rack server, herein referred to collectively as an electronics server. A server chassis is configured to house multiple electronics servers. Each electronics server is coupled to a backplane or mid-plane within the server chassis. Each electronics server includes one or more heat generating devices as is well known in the art.
FIG. 1 illustrates a cooling door assembly 10 coupled to an electronics enclosure 80 according to an embodiment of the present invention. The cooling door assembly 10 includes a frame 12 and cooling door 14. The frame 12 is coupled to the electronics enclosure 80 using any conventional attachment means including, but not limited to screws, bolts, and rivets. In some embodiments, the frame 12 is additionally fitted with one or more flanges (not shown) on the top, sides and/or bottom. The one or more flanges provide mechanical support while mounting the frame 12 to the electronics enclosure. The cooling door assembly 10 “hangs” on the back of the electronics enclosure 80 using the one or more flanges while the frame 12 is being mounted. In some embodiments, an adapter mounting mechanism is mounted to the electronics enclosure. The adapter mounting mechanism provides a mounting surface to which the frame 12 is mounted. The frame 12 is coupled to the electronics enclosure 80 using one or more attachment means including, but not limited to, bolts, screws, and rivets. The flanges are either fixed in position or are designed to be adjustable at the time of installation. In some embodiments, the cooling door assembly 10 is pre-assembled, ready to be attached in the field, thus the cooling door assembly 10 can be designed to be universal. The cooling door assembly 10 can be made in the style of a pre-hung door with the frame 12 and the cooling door 14 already fitted and plumbed inside. In some embodiments, the frame 12 is mounted to the electronics enclosure 80 and can be custom designed for each cabinet, while the actual cooling door 14 within the frame 12 is a standard size. In other embodiments, the cooling door assembly 10 is integrated into the electronics enclosure 80 during construction.
One or more external supply lines 20 provide coolant from an external source, such as an external cooling system, to the cooling door assembly 10 via a supply mounting block 16 within the frame 12. As shown in FIG. 1, two external supply lines 20 are coupled to the supply mounting block 16. It is understood that the supply mounting block can be configured to couple with more or less than two external supply lines. The use of multiple supply lines provides system scalability. Frame supply lines 24 and 26 couple the supply mounting block 16 to a swivel joint 28 on the cooling door 14. The frame supply lines 24 and 26 are included within the frame 12.
A flex assembly 38 is coupled to the swivel joint 28, and a cooling door supply line 40 is coupled to the flex assembly 38. A heat exchanging panel 8 is coupled to the cooling door supply line 40 via a panel supply line 42. The heat exchanging panel 8 is also coupled to a cooling door return line 58 via a panel return line 50. A heat exchanging panel 6 is coupled to the cooling door supply line 40 via a panel supply line 44. The heat exchanging panel 6 is also coupled to the cooling door return line 58 via a panel return line 52. A heat exchanging panel 4 is coupled to the cooling door supply line 40 via a panel supply line 46. The heat exchanging panel 4 is also coupled to the cooling door return line 58 via a panel return line 54. A heat exchanging panel 2 is coupled to the cooling door supply line 40 via a panel supply line 48. The heat exchanging panel 2 is also coupled to the cooling door return line 58 via a panel return line 56. Each heat exchanging panel includes a fluid input header and a fluid output header. The fluid input header is configured with one or more fluid input ports, and the fluid output header is configured with one or more fluid output ports. The panel supply line for each heat exchanging panel is coupled to the corresponding fluid input header, and the panel return line for each heat exchanging panel is coupled to the corresponding fluid output header. Where the fluid input header includes multiple fluid input ports, either a single common panel supply line is coupled to the multiple fluid input ports, or a separate panel supply line is coupled from the cooling door supply line to each of the fluid input ports. Where the fluid output header includes multiple fluid output ports, either a single common panel return line is coupled to the multiple fluid output ports, or a separate panel return line is coupled from each of the fluid output ports to the cooling door return line. The cooling door 14 is configured such that coolant flow through each of the heat exchanging panels 2, 4, 6, 8 is from bottom to top. Such a configuration provides a more consistent and uniform coolant flow through the heat exchanging panels than a top to bottom coolant flow configuration.
The cooling door return line 58 is coupled to a flex assembly 36, and the flex assembly 36 is coupled to a swivel joint 30. The swivel joint 30 is coupled to one or more external return lines 22 via a return mounting block 18. As shown in FIG. 1, two external return lines 22 are coupled to the return mounting block 18. It is understood that the return mounting block can be configured to couple with more or less than two external return lines.
The cooling door assembly 10 shown in FIG. 1 includes two mounting blocks, the supply mounting block 16 and the return mounting block 18, each positioned at the top of the frame 12 to match the position of the external supply and return lines. In alternative embodiments, either or both of the mounting blocks can be positioned on the bottom of the frame 12. In this alternative configuration, the mounting blocks can be positioned to match a position of the external supply and return lines, or the external supply and/or return lines can be rerouted to match a desired position of the mounting blocks. Still alternatively, more than two mounting blocks can be positioned in the top, bottom, or combination of top and bottom of the frame 12. Each mounting block is configured with one or more fluid paths passing therethrough.
The cooling door 14 is coupled to the frame 12 using a plurality of mechanical hinges 32, 34. The mechanical hinges 32, 34 are configured as load-bearing connection points and are also configured to enable the cooling door 14 to rotate relative to the frame 12. Although two mechanical hinges 32 and 34 are shown in FIG. 1, it is understood that the cooling door assembly can be configured to include more than two mechanical hinges. In some embodiments, the swivel joints are configured as load-bearing connection points, where the functionality of the swivel joint, such as swivel joint 28, and the mechanical hinge, such as mechanical hinge 32, are integrated within a single element.
Each swivel joint 28, 30 is configured to enable the cooling door 16 to rotate relative to the frame 12, and in particular relative to the mounting block 18 and the frame supply line 26, while maintaining a sealed fluid path between the frame 12 and the cooling door 14.
In operation, coolant is provided to the supply mounting block 16 via the external supply lines 20. The coolant flows through the supply mounting block 16, through the frame supply lines 24 and 26 and to the cooling door 14 via the swivel joint 28. Coolant flows from the swivel joint 28 through the flex assembly 38 to the cooling door supply line 40. Coolant is provided to each of the heat exchanging panels 2, 4, 6, 8 from the cooling door supply line 40 via the panel supply lines 48, 46, 44, 42, respectively. Coolant flows through each of the heat exchanging panels 2, 4, 6, 8 to the panel returns lines 56, 54, 52, 50, respectively, and into the cooling door return line 58. Coolant flows from the cooling door return line 58 through the flex assembly 36 to the swivel joint 30 and into the return mounting block 18. Coolant is output from the cooling door assembly 10 to the external return lines 22 via the return mounting block 18. Air from inside the electronics enclosure 80 is directed out of the enclosure through each of the heat exchanging panels 2, 4, 6, 8 within the cooling door 14. As air passes through each of the heat exchanging panels 2, 4, 6, 8, and over the heat exchanging surfaces of the heat exchanging panels 2, 4, 6, 8, heat is transferred from the air to the coolant flowing through the heat exchanging panels 2, 4, 6, 8. The heated coolant is then output from the cooling door assembly to an external cooling system via the external return lines 22, where the coolant is cooled and returned to the cooling door assembly 10 via the external supply lines 20.
FIG. 2 illustrates an enlarged portion of the cooling door assembly 10 of FIG. 1. The flex assembly 36 includes a rigid right-angle bend 64, a flexible piping 68 coupled to a first end of the rigid right-angle bend 64, and a flexible piping 66 coupled a second end of the rigid right-angle bend 64. The flexible piping 66 is coupled to the cooling door return line 58. The flexible piping 68 is coupled to the swivel joint 30. Use of the flexible piping 66 and 68 allows for forgiveness in component and alignment tolerances and movement in three-dimensions. The mechanical hinges 32 and 34 (FIG. 1) and the swivel joints 30 and 28 (FIG. 1) optimally have all their axis of rotation co-linear in order for the cooling door 14 to properly open and close without binding within the coolant flow path. If the axis are not collinear, then some amount of flex is required to prevent binding. The flexible piping 66 and 68 allows for some flex and misalignment to be taken up. The rigid right-angle bend 64 allows one arm, such as the flexible piping 68 to move axially because the movement is taken up by a bend in the other arm, such as the flexible piping 66. Such a flexible configurations allows for flexibility in the alignment of components in the joints, heat exchanger panels, and non-moving parts of the cooling door during normal use. The flexible configuration also assists in the alignment of components during assembly.
The return mounting block 18 shown in FIG. 2 includes three interconnection openings for coupling with the external return lines 22 and the swivel joint 30. Specifically, an interconnection opening 70 is configured to couple with an interconnect 80 of a first external return line 22, and an interconnection opening 72 is configured to couple with an interconnect 82 of a second external return line 22. The return mounting block 18 also includes a third interconnection opening (not shown) configured to couple with a first interconnect (not shown) of the swivel joint 30. Similarly, the supply mounting block 16 shown in FIG. 2 includes three interconnection openings for coupling with the external supply lines 20 and the frame supply line 24. Specifically, an interconnection opening 74 is configured to couple with an interconnect 60 of a first external supply line 20, and an interconnection opening 76 is configured to couple with an interconnect 62 of a second external supply line 20. The supply mounting block 16 also includes a third interconnection opening (not shown) configured to couple with a first interconnect (not shown) of the frame supply line 24.
In some embodiments, each of the panel supply lines 42, 44, 46, and 48 include a flow control regulator or valve. As shown in FIG. 2, the panel supply line 48 includes a flow control regulator or valve 78. The flow control regulators or valves are configured to balance coolant flow in each of the heat exchanging panels 2, 4, 6, 8. Alternatively, the flow control regulators or valves are used to independently regulate coolant flow within each of the heat exchanging panels 2, 4, 6, 8. The flow control regulators or valves can also be used shut off coolant flow to the heat exchanging panels, either for servicing or capacity reasons. In some embodiments, a heat removal capacity of the cooling door assembly 10 can be changed by replacing flow control regulators with a first flow rate with flow control regulators with a different flow rate. In other embodiments, a flow control regulator is positioned in the frame supply line or the cooling door supply line. In general, a flow control regulator can be positioned in any part of the supply side fluid lines.
As shown in FIG. 1, the cooling door assembly is configured as a passive system that relies on air movement generated within the electronics enclosure 80, for example fans included within the electronics enclosure to cool electronics servers. In this configuration, there are no additional fans used to move the air through the one or more heat exchanger panels in the cooling door. In other embodiments, the cooling door assembly is configured as an active system configured to regulate and/or adjust the air flow directed at and through the cooling door. The active system includes one or more of a fan tray, airflow guides, one or more air movers, one or more thermal sensors, one or more anemometers, and a control module. The air flow guides are configured to guide cooling air in a defined manner. The one or more air movers, such as fans, are either fixed or variable speed. The one or more thermal sensors and the one or more anemometers are positioned in the airstream prior to the one or more heat exchangers and/or in the airstream after the one or more heat exchangers. The one or more anemometers measure the rate of airflow and the one or more thermal sensors measure the temperature. The control module is configured to use data received from the one or more thermal sensors and/or the one or more anemometers to adjust the fan speeds into favorable performance zones, thereby increasing efficiency of the system. The system can also be configured such that the control module controls the coolant flow rate by controlling the flow control regulators or valves.
The cooling door assembly shown in FIGS. 1 and 2 is an exemplary configuration. It is understood that the various components can be positioned and sequenced in different configurations to achieve the same or similar results. For example, the frame can be configured with external supply line and external return line interconnects that are separate from the mounting blocks. In such a configuration, the interconnect openings of the mounting blocks are not directly connected to the external supply and return lines. Instead, intermediate frame return and supply lines within the frame are coupled between the mounting blocks and the external supply and return lines. Another alternative configuration includes coupling a mounting block to each swivel joint, providing additional support and alignment of the cooling door relative to the frame.
FIG. 3 illustrates a cooling door assembly 110 according to another embodiment of the present invention. The cooling door assembly 110 is configured to be mounted to an electronics enclosure, such as the electronics enclosure 80 (FIG. 1). The cooling door assembly 110 is configured and operates similarly to the cooling door assembly 10 (FIG. 1) except that the mounting blocks 116 and 118 of the cooling door assembly 110 are not coupled directly to the external supply lines (not shown) and the external return lines (not shown). Specifically, the cooling door assembly 110 includes frame supply interconnects 180 and 182 configured to be coupled to the external supply lines. The frame supply interconnects 180 and 182 are coupled to the frame supply line 124 via a frame supply line 190. The cooling door assembly 110 also includes frame return interconnects 184 and 186 configured to be coupled to the external return lines. The frame return interconnects 184 and 186 are coupled to the mounting block 118 via a frame return line 188. Although a single frame return line 188 is shown in FIG. 3, more than one frame return line can be coupled between the frame return interconnects and the mounting block. Additionally, the mounting block 116 is not positioned in the top of the frame 112, as in the cooling door assembly 10 (FIG. 1), but instead the mounting block 116 is positioned at the bottom of the frame 112 and is coupled to the swivel joint 128.
The cooling door assembly 110 is also configured to operate within a two-phase cooling system. In such a system, coolant input to the cooling door assembly 110 is in a liquid phase, and the coolant output from the cooling door assembly 110 is in a gas phase or a combination of liquid and gas phase. The coolant in the cooling door assembly 110 remains in the liquid phase until it enters the heat exchanging panels 102, 104, 106, 108. In an exemplary application, the mass flow rate of the coolant through the cooling door assembly is substantially constant. Since coolant in a gas phase has a greater volume than the same coolant in a liquid phase, the return lines in the cooling door assembly 110 are configured with a greater diameter than the supply lines within the cooling door assembly 110. Accordingly, the frame supply interconnects 180 and 182 have a smaller diameter than the frame return interconnects 184 and 186. The frame supply lines 124, 126, and 190, the cooling door supply line 140, and the panel supply lines 142, 144, 146, and 148 have a smaller diameter than the frame return line 188, the cooling door return line 158, and the panel return lines 150, 152, 154, and 156. The components of the flex assembly 138 have smaller diameters than the components of the flex assembly 136. The interconnects of the swivel joint 128 and the mounting block 116 are smaller in diameter than the interconnects of the swivel joint 130 and the mounting block 118, respectively. Similarly, the external supply line interconnects (not shown) and the external supply lines (not shown) have a smaller diameter than the external return line interconnects (not shown) and the external return lines(not shown), respectively. Configuring the components in the supply path with smaller diameters than the complimentary components in the return path functions to alleviate increased pressure due to the phase change of the coolant from liquid to gas.
In some embodiments, a single swivel joint and a single mounting block are used, where the swivel joint and the mounting block coupled to the swivel joint are each configured with at least two independent fluid paths. One fluid path is used to supply coolant to the cooling door from the frame, and another fluid path is used to return coolant from the cooling door to the frame. In such a configuration, a flux assembly and a cooling door supply line are used to couple the single swivel joint to each of the panel supply lines.
FIG. 4 illustrates a cooling door assembly 210 configured according to another embodiment of the present invention. The cooling door assembly 210 is configured to be mounted to an electronics enclosure, such as the electronics enclosure 80 (FIG. 1). The cooling door assembly 210 functions similarly as the cooling door assemblies 10, 110 except the cooling door assembly 210 includes a single swivel joint 230 and a single mounting block 218, as opposed to the two swivel joints and the two mounting block of the cooling door assemblies 10, 110. The swivel joint 230 is configured with two independent fluid paths, a supply fluid path to supply fluid from the frame 212 to the cooling door 214, and a return fluid path to return fluid from the cooling door 214 to the frame 212. In some embodiments, the two-path swivel joint 230 is a co-axial swivel joint having a center fluid path and an outer fluid path, similar conceptually to a pipe within a pipe where each pipe is capable of rotating about a center axis. The supply fluid path of the swivel joint 230 is coupled to a cooling door supply line 240 via a flex assembly 238. The cooling door supply line 240 is coupled to panel supply lines 242, 244, 246, 248, which are in turn coupled to heat exchanging panels 208, 206, 204, 202, respectively, to receive input fluid.
The heat exchanging panels 208, 206, 204, 202 are also coupled to panel return lines 250, 252, 254, 246, respectively, to output fluid from the heat exchanging panels. The panel return lines 250, 252, 254, 256 are coupled to a cooling door return line 258, which is coupled to a flex assembly 236. The flex assembly 236 is coupled to the return fluid path of the swivel joint 230.
The mounting block 218 also includes two independent fluid paths, a supply fluid path and a return fluid path. The supply fluid path of the mounting block 218 is coupled to the supply fluid path of the swivel joint 230 and to one or more frame supply lines (not shown). The frame supply line(s) is coupled to frame supply interconnects 280, 282. The return fluid path of the mounting block 218 is coupled to the return fluid path of the swivel joint 230 and to a frame return line (not shown). The frame return line(s) is coupled to frame return interconnects 284, 286.
The cooling door 214 is mounted to the frame 212 using a plurality of hinges, such as hinges 232 and 234. In some embodiments, the swivel joint 230 is also configured as a load-bearing hinge.
The single swivel joint configuration of the cooling door assembly 210 reduces the number of swivel joints and mounting block, and also reduces the amount of frame fluid lines used to direct fluid flow to and from the cooling door 214. The cooling door assembly 210 can be configured as either a single-phase cooling system or a two-phase cooling system.
The cooling door assemblies described and illustrated in relation to FIGS. 1-3 include two swivel joints. In some embodiments, more than two swivel joints can be used. In this configuration, the frame includes reconfigured and/or additional fluid supply lines and fluid return lines to accommodate the additional swivel joints. In an exemplary configuration, a pair of swivel joints are coupled to each heat exchanging panel, one swivel joint to supply fluid, and one swivel joint to return fluid to the fluid lines coupled to the frame. In another exemplary configuration, a pair of swivel joints is coupled to multiple heat exchanging panels coupled in series, such as a fluid supply swivel joint coupled to each of the heat exchanging panels 8 and 4 in FIG. 1, a fluid return swivel joint coupled to each of the heat exchanging panels 6 and 2 in FIG. 1, where the heat exchanging panels 8 and 6 are fluidically coupled in series and the heat exchanging panels 4 and 2 are fluidicially coupled in series.
In another exemplary configuration, a single input swivel joint is coupled to a common cooling door supply line and a pair of output swivel joints. Each output swivel joint is coupled to multiple heat exchanging panels. FIG. 5 illustrates a cooling door assembly 310 configured according to yet another embodiment of the present invention. FIG. 6 illustrates an enlarged top portion of the cooling door assembly 310 of FIG. 5 with a portion of the frame paneling removed. FIG. 7 illustrates an enlarged bottom portion of the cooling door assembly 310 of FIG. 5 with a portion of the frame paneling removed. The cooling door assembly 310 is configured to be mounted to an electronics enclosure, such as the electronics enclosure 80 (FIG. 1). The cooling door assembly 310 functions similarly as the cooling door assemblies 10, 110 except the cooling door assembly 310 includes a single input swivel joint 328 and two output swivel joints 318, 319, as opposed to the single input swivel joint and single output swivel joint of the cooling door assemblies 10, 110. The cooling door assembly 310 also differs from the cooling door assemblies 10, 110 in that the flex mechanism used for component alignment is no longer included in the cooling door, but instead is included in the frame 312 and/or as part of the mounting mechanism used to mount the cooling door 314 to the frame 312.
The inlet swivel joint 328 is coupled to an inlet mounting block 316. The mounting block 316 is fluidically coupled to the frame 312 via a frame supply line 326 (FIG. 7) and mechanically coupled to a front frame plate 303 of the frame 312 via a plurality of grommets 317. The grommets 317 are made of a flexible and compressible material that provide a degree of float between the mounting block 316 and the front frame plate 303. The float provided by the grommets enables movement of the mounting block relative to the frame so that the mounting block is not rigidly mounted to the frame. In some embodiments, the grommets are made of rubber.
The outlet swivel joint 330 is coupled to an outlet mounting block 318, and the outlet swivel joint 331 is coupled to an outlet mounting block 319. The mounting block 318 is fluidically coupled to the frame 312 via frame return line 323, and the mounting block 319 is fluidically coupled to the frame 312 via a frame return line 329. Each of the mounting blocks 318, 319 are mechanically coupled to the front frame plate 303 via a plurality of grommets 315 and 321, respectively.
Each of the swivel joints 328, 330, 331 is configured with a fluid path, which is coupled to a fluid path within the mounting blocks 316, 318, 319, respectively. The fluid path through the mounting block 316 and the inlet swivel joint 328 provides a supply fluid path to supply fluid from the frame 312 to the cooling door 314. A common cooling door supply line 338 (FIG. 6) and 340 (FIGS. 6 and 7) provides fluid from the inlet swivel joint 328 to panel supply lines 348, 346, 344, 342 for heat exchanging panels 302, 304, 306, 308, respectively. Fluid is output from the heat exchanging panels 306, 308 via panel return lines 352, 350, respectively, to a cooling door return line 359 (FIG. 6). The cooling door return line 359 is coupled to the fluid path through the outlet swivel joint 331. Similarly, fluid is output from the heat exchanging panels 302, 304 via panel return lines 356, 354, respectively, to a cooling door return line 358 (FIG. 6). The cooling door return line 358 is coupled to the fluid path through the outlet swivel joint 330.
The frame return line 329 is coupled to the frame return line 323 via a flexible piping 325. The flexibility of the flexible piping provides independent movement of the mounting block 318/swivel joint 330 relative to the mounting block 319/swivel joint 331. If the mounting block 318/swivel joint 330 were rigidly coupled to the mounting block 319/swivel joint 331, then movement of one would cause in movement of the other. However, movement of both the mounting block 318/swivel joint 330 and the mounting block 319/swivel joint 331 may not be needed for proper alignment. The flexible piping 325 provides this independent movement.
Fluid is output from the frame 312 via frame return interconnects 384, 386, which are coupled to external return lines (not shown). The frame return interconnects 384, 386 are coupled to the frame return line 323. Fluid is input to the frame 312 via frame supply interconnects 380, 382, which are coupled to external supply lines (not shown). The frame supply interconnects 380, 382 are coupled to the mounting block 316 via frame supply lines 324 and 326. In some embodiments, flexible piping is included in either the frame supply line 324 and/or the frame supply line 326, such as flexible piping 327. Use of flexible piping in the frame supply lines provides float for properly aligning the mounting block 316/swivel joint 328.
The movement provided by the grommets and flexible piping enables the swivel joints to float into proper alignment of the cooling door relative to the frame. When mounting the cooling door to the frame, the hinge axis and the swivel joint axis must be aligned. The movement provided by the grommets and/or the flexible piping enable proper alignment of the cooling door to the frame.
Although not shown in FIGS. 1-3, grommets can be used to mount the mounting blocks to the frame in the cooling door assemblies 10, 110. In the case of a single inlet swivel joint and a single outlet swivel joint, such as the cooling door assemblies 10, 110, flexible piping in the frame is can also be used, such as part of the frame supply lines 24, 124 and/or 26, 126 to provide float for the inlet swivel joint/mounting block. In some embodiments, the frame interconnection openings (such as interconnection openings 370 and 374 in FIG. 6, and interconnection openings 70, 72, 74, 76 in FIG. 2) are slightly larger than the diameter of the fluid lines that pass through, thereby providing an additional float to be used for alignment of the cooling door to the frame. In general, a flex mechanism used to properly align the cooling door to the frame includes one, some, or all of any combination of the flexible piping in the cooling door and/or the frame, the grommets coupled to the mounting blocks, and the float between the interconnection openings and the fluid lines. The flex mechanism provides float for the swivel joints to be properly aligned in order to minimize stress.
In some embodiments, the swivel joints 328, 330, 331 are configured as load-bearing elements and therefore also function as hinges. In other embodiments, hinges independent of the swivel joints are used, in which case the swivel joints may or may not be configured as load-bearing elements.
The cooling door assembly 310 can be configured as either a single-phase cooling system or a two-phase cooling system.
The cooling door assemblies are described above as including a cooling door coupled to a frame, and the frame is mounted to an electronics enclosure. In this configuration, the cooling door assemblies are mounted to the electronics enclosure without having to add additional plumbing to the electronics enclosure. Alternatively, the cooling doors are configured to mount directly to the electronics enclosures. In such configurations, additional plumbing, such as frame supply lines, frame return lines, and/or mounting blocks, is added to the electronics enclosure to provide the necessary fluid connections to the external fluid supply and return lines.
In some embodiments, the cooling door is further configured to provide an amount of electro-magnetic interference (EMI) protection, such as adding a screen with opening to allow airflow the heat exchangers. Additionally, EMI gasketing can be used where the frame attaches to the rack and around where the cooling door closes. EMI gasketing functions to seal the cooling door and restrict the air from leaving the enclosure without passing through the heat exchangers in the cooling door.
The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of the principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention.

## Claims

1. A cooling door assembly comprising:
a. a frame including one or more external supply line interconnects configured to receive a coolant, and one or more external return line interconnects configured to output the coolant, wherein the frame is configured to be coupled to an electronics enclosure;
b. a cooling door including one or more heat exchangers configured to pass the coolant therethrough;
c. one or more inlet swivel joints coupled to the frame and to the cooling door, wherein each of the one or more inlet swivel joints includes an inlet coolant path coupled between the one or more external supply line interconnects and the one or more heat exchangers;
d. one or more outlet swivel joints coupled to the frame and to the cooling door, wherein each of the one or more outlet swivel joints includes an outlet coolant path coupled between the one or more heat exchangers and the one or more external return line interconnects,

wherein the one or more inlet swivel joints are each configured to rotate while maintaining the inlet coolant path between the one or more supply line interconnects and the one or more heat exchangers, and the one or more outlet swivel joints are each configured to rotate while maintaining the outlet coolant path between the one or more heat exchangers and the one or more external return line interconnects, thereby enabling the cooling door to rotate relative to the frame while maintaining a coolant path between the frame and the cooling door.

2. The cooling door assembly of claim 1 further comprising a plurality of load-bearing mechanical hinges coupled to the frame and the cooling door, wherein the one or more inlet swivel joints, the one or more outlet swivel joints, and the plurality of mechanical hinges are aligned substantially co-linearly.

3. The cooling door assembly of claim 1 wherein the one or more inlet swivel joints and the one or more outlet swivel joints are configured as load-bearing hinges coupled to the frame and to the cooling door.

4. The cooling door assembly of claim 1 wherein the coolant is a refrigerant.

5. The cooling door assembly of claim 1 wherein the coolant comprises water.

6. The cooling door assembly of claim 1 wherein the frame further comprises a frame supply line coupled between the external supply line interconnects and the one or more inlet swivel joints.

7. The cooling door assembly of claim 1 wherein the frame further comprises one or more frame return lines coupled between the one or more outlet swivel joints and the external return line interconnects.

8. The cooling door assembly of claim 7 wherein if the one or more outlet swivel joints comprises multiple outlet swivel joints, then the one or more frame return lines are commonly coupled to each of the multiple outlet swivel joints.

9. The cooling door assembly of claim 1 wherein the cooling door assembly comprises a single phase cooling system and the coolant remains in a single phase.

10. The cooling door assembly of claim 1 wherein the cooling door assembly comprises a two-phase cooling system and at least a portion of the coolant undergoes a phase change within the cooling door assembly.

11. The cooling door assembly of claim 10 wherein a diameter of each of the one or more external supply line interconnects is equal to or smaller than a diameter of each of the one or more external return line interconnects.

12. The cooling door assembly of claim 11 wherein a diameter of all fluid supply paths inputting fluid to the one or more heat exchangers is equal to or smaller than a diameter of all fluid return paths outputting fluid from the one or more heat exchangers.

13. The cooling door assembly of claim 1 wherein each of the one or more heat exchangers includes one or more coolant inlet ports at a bottom of the heat exchanger and one or more coolant output ports at a top of the heat exchanger such that coolant flows from the bottom of the heat exchanger to the top of the heat exchanger.

14. The cooling door assembly of claim 1 wherein the cooling door further comprises a cooling door supply line coupled between the one or more inlet swivel joints and the one or more heat exchangers, and a cooling door return line coupled between the one or more heat exchangers and the one or more outlet swivel joints.

15. The cooling door assembly of claim 14 wherein the cooling door further comprises one or more heat exchanger supply lines, one heat exchanger supply line for each heat exchanger and each heat exchanger supply line is coupled between the cooling door supply line and the heat exchanger.

16. The cooling door assembly of claim 15 further comprising a flow control regulator coupled to each heat exchanger supply line.

17. The cooling door assembly of claim 1 further comprising a flow control regulator coupled to at least one of a frame supply line coupled between the external supply line interconnects and the one or more inlet swivel joints, and a cooling door supply line coupled between the one or more inlet swivel joints and the one or more heat exchangers.

18. The cooling door assembly of claim 1 wherein the frame further comprises one or more outlet mounting blocks, each one of the one or more outlet mounting blocks is coupled to one of the one or more outlet swivel joints.

19. The cooling door assembly of claim 18 wherein each of the one or more outlet mounting blocks is coupled to the one or more external return line interconnects.

20. The cooling door assembly of claim 18 wherein one of the one or more outlet mounting blocks includes the one or more external return line interconnects.

21. The cooling door assembly of claim 18 wherein the frame further comprises one or more inlet mounting blocks, each one of the inlet mounting blocks is coupled to one of the one or more inlet swivel joints.

22. The cooling door assembly of claim 21 wherein each of the one or more inlet mounting blocks is coupled to the one or more external supply line interconnects.

23. The cooling door assembly of claim 21 wherein one of the one or more inlet mounting blocks includes the one or more external supply line interconnects.

24. A cooling door assembly comprising:
a. a frame including one or more external supply line interconnects configured to receive a coolant, and one or more external return line interconnects configured to output the coolant, wherein the frame is configured to be coupled to an electronics enclosure;
b. a cooling door including one or more heat exchangers configured to pass the coolant therethrough;
c. a swivel joint coupled to the frame, wherein the swivel joint includes at least two independent coolant paths, a first coolant path is coupled between the one or more external supply line interconnects and the one or more heat exchangers, and a second coolant path is coupled between the one or more heat exchangers and the one or more external return line interconnects,

wherein the swivel joint is configured to rotate while maintaining the first coolant path between the one or more supply line interconnects and the one or more heat exchangers, and maintaining the second coolant path between the one or more heat exchangers and the one or more external return line interconnects, thereby enabling the cooling door to rotate relative to the frame while maintaining the first coolant path and the second coolant path between the frame and the cooling door.

25. The cooling door assembly of claim 24 further comprising a plurality of load-bearing mechanical hinges coupled to the frame and the cooling door, wherein the swivel joint and the plurality of mechanical hinges are aligned substantially co-linearly.

26. The cooling door assembly of claim 24 wherein the swivel joint is configured as a load-bearing hinge coupled to the frame and to the cooling door.

27. The cooling door assembly of claim 24 wherein the coolant is a refrigerant.

28. The cooling door assembly of claim 24 wherein the coolant comprises water.

29. The cooling door assembly of claim 24 wherein the frame further comprises a frame supply line coupled between the external supply line interconnects and the swivel joint.

30. The cooling door assembly of claim 24 wherein the frame further comprises one or more frame return lines coupled between the swivel joint and the external return line interconnects.

31. The cooling door assembly of claim 24 wherein the cooling door assembly comprises a single phase cooling system and the coolant remains in a single phase.

32. The cooling door assembly of claim 24 wherein the cooling door assembly comprises a two-phase cooling system and at least a portion of the coolant undergoes a phase change within the cooling door assembly.

33. The cooling door assembly of claim 32 wherein a diameter of each of the one or more external supply line interconnects is equal to or smaller than a diameter of each of the one or more external return line interconnects.

34. The cooling door assembly of claim 33 wherein the swivel joint includes a plurality of first coolant interconnects coupled to the first fluid path and a plurality of second coolant interconnects coupled to the second fluid path, and a diameter of each first coolant interconnect is equal to or smaller than a diameter of each second coolant interconnect.

35. The cooling door assembly of claim 24 wherein each of the one or more heat exchangers includes one or more coolant inlet ports at a bottom of the heat exchanger and one or more coolant output ports at a top of the heat exchanger such that coolant flows from the bottom of the heat exchanger to the top of the heat exchanger.

36. The cooling door assembly of claim 24 wherein the cooling door further comprises a cooling door supply line coupled between the swivel joint and the one or more heat exchangers, and a cooling door return line coupled between the one or more heat exchangers and the swivel joint.

37. The cooling door assembly of claim 36 wherein the cooling door further comprises one or more heat exchanger supply lines, one heat exchanger supply line for each heat exchanger and each heat exchanger supply line is coupled between the cooling door supply line and the heat exchanger.

38. The cooling door assembly of claim 37 further comprising a flow control regulator coupled to each heat exchanger supply line.

39. The cooling door assembly of claim 24 further comprising a flow control regulator coupled to at least one of a frame supply line coupled between the external supply line interconnects and the one or more inlet swivel joints, and a cooling door supply line coupled between the one or more inlet swivel joints and the one or more heat exchangers.

40. The cooling door assembly of claim 24 wherein the frame further comprises a first mounting block, wherein the first mounting block is coupled to the swivel joint.

41. The cooling door assembly of claim 40 wherein the first mounting block is coupled to the one or more external return line interconnects.

42. The cooling door assembly of claim 40 wherein the first mounting block includes the one or more external return line interconnects.

43. The cooling door assembly of claim 40 wherein the frame further comprises a second mounting block, wherein the second mounting block is coupled to the cooling door supply line.

44. The cooling door assembly of claim 43 wherein the second mounting block is coupled to a frame supply line within the frame.

45. The cooling door assembly of claim 24 further comprising one or more additional swivel joints coupled to the frame, each additional swivel joint is configured with at least two independent coolant paths, one coolant path coupled between the one or more heat exchangers and the one or more external return line interconnects, and another coolant path between the one or more external supply line interconnects and the one or more heat exchangers.

46. A cooling door assembly comprising:
a. a frame including one or more external supply line interconnects configured to receive a coolant, and one or more external return line interconnects configured to output the coolant, wherein the frame is configured to be coupled to an electronics enclosure;
b. a cooling door including one or more heat exchangers configured to pass the coolant therethrough;
c. one or more inlet swivel joints coupled to the frame and to the cooling door, wherein each of the one or more inlet swivel joints includes an inlet coolant path, further wherein the one or more inlet swivel joints are each configured to rotate while maintaining the inlet coolant path, thereby maintaining an inlet coolant path between the one or more supply line interconnects and the one or more heat exchangers;
d. one or more outlet swivel joints coupled to the frame and to the cooling door, wherein each of the one or more outlet swivel joints includes an outlet coolant path, further wherein the one or more outlet swivel joints are each configured to rotate while maintaining the outlet coolant path, thereby maintaining an outlet coolant path between the one or more heat exchangers and the one or more external return line interconnects; and
e. a flex mechanism coupled to the one or more inlet swivel joints and to the one or more outlet swivel joints.

47. The cooling door assembly of claim 46 wherein the flex mechanism includes a first flex assembly coupled between each of the one or more inlet swivel joints and the one or more heat exchangers, and a second flex assembly coupled between the one or more heat exchangers and each of the one or more outlet swivel joints.

48. The cooling door assembly of claim 46 further comprising a plurality of load-bearing mechanical hinges coupled to the frame and the cooling door, wherein the one or more inlet swivel joints, the one or more outlet swivel joints, and the plurality of mechanical hinges are aligned substantially co-linearly.

49. The cooling door assembly of claim 46 wherein the one or more inlet swivel joints and the one or more outlet swivel joints are configured as load-bearing hinges coupled to the frame and to the cooling door.

50. The cooling door assembly of claim 46 wherein the coolant is a refrigerant.

51. The cooling door assembly of claim 46 wherein the coolant comprises water.

52. The cooling door assembly of claim 46 wherein the frame further comprises a frame supply line coupled between the external supply line interconnects and the one or more inlet swivel joints.

53. The cooling door assembly of claim 52 wherein the flex mechanism includes one or more flexible pipes included as part of the frame supply line.

54. The cooling door assembly of claim 46 wherein the frame further comprises one or more frame return lines coupled between the one or more outlet swivel joints and the external return line interconnects.

55. The cooling door assembly of claim 54 wherein if the one or more outlet swivel joints comprises multiple outlet swivel joints, then the one or more frame return lines form a common frame return line coupled to each of the multiple outlet swivel joints, and the flex mechanism includes a flexible piping included as part of the common frame return line.

56. The cooling door assembly of claim 46 wherein the cooling door assembly comprises a single phase cooling system and the coolant remains in a single phase.

57. The cooling door assembly of claim 46 wherein the cooling door assembly comprises a two-phase cooling system and at least a portion of the coolant undergoes a phase change within the cooling door assembly.

58. The cooling door assembly of claim 57 wherein a diameter of each of the one or more external supply line interconnects is equal to or smaller than a diameter of each of the one or more external return line interconnects.

59. The cooling door assembly of claim 57 wherein a diameter of all fluid supply paths inputting fluid to the one or more heat exchangers is equal to or smaller than a diameter of all fluid return paths outputting fluid from the one or more heat exchangers.

60. The cooling door assembly of claim 46 wherein each of the one or more heat exchangers includes one or more coolant inlet ports at a bottom of the heat exchanger and one or more coolant output ports at a top of the heat exchanger such that coolant flows from the bottom of the heat exchanger to the top of the heat exchanger.

61. The cooling door assembly of claim 46 wherein the cooling door further comprises a cooling door supply line coupled between the one or more inlet swivel joints and the one or more heat exchangers, and a cooling door return line coupled between the one or more heat exchangers and the one or more outlet swivel joints.

62. The cooling door assembly of claim 61 wherein the cooling door further comprises one or more heat exchanger supply lines, one heat exchanger supply line for each heat exchanger and each heat exchanger supply line is coupled between the cooling door supply line and the heat exchanger.

63. The cooling door assembly of claim 62 further comprising a flow control regulator coupled to each heat exchanger supply line.

64. The cooling door assembly of claim 46 further comprising a flow control regulator coupled to at least one of a frame supply line coupled between the external supply line interconnects and the one or more inlet swivel joints, and a cooling door supply line coupled between the one or more inlet swivel joints and the one or more heat exchangers.

65. The cooling door assembly of claim 46 wherein the flex mechanism is configured to accommodate a range of assembly tolerances within the cooling door assembly.

66. The cooling door assembly of claim 46 wherein the frame further comprises one or more outlet mounting blocks, each one of the one or more outlet mounting blocks is coupled to one of the one or more outlet swivel joints.

67. The cooling door assembly of claim 66 wherein each of the one or more outlet mounting blocks is coupled to the one or more external return line interconnects.

68. The cooling door assembly of claim 66 wherein one of the one or more outlet mounting blocks includes the one or more external return line interconnects.

69. The cooling door assembly of claim 66 wherein the frame further comprises one or more inlet mounting blocks, each one of the inlet mounting blocks is coupled to one of the one or more inlet swivel joints.

70. The cooling door assembly of claim 69 wherein each of the one or more inlet mounting blocks is coupled to the one or more external supply line interconnects.

71. The cooling door assembly of claim 69 wherein one of the one or more inlet mounting blocks includes the one or more external supply line interconnects.

72. The cooling door assembly of claim 69 wherein the flex mechanism includes a plurality of grommets coupled between each of the one or more inlet mounting blocks and a frame panel and between each of the one or more outlet mounting blocks and a frame panel.