Modular scalable liquid cooled power system

A scalable liquid cooled power system using a number of modularized, hot-plug, hot-swap, and scalable liquid-cooled power conversion modules mounted on mating mounting assemblies. A modularized, scalable liquid coolant manifolds and liquid cooling management system provides coolant circulation through the power conversion modules. The system optionally includes a highly scalable system control and administration system, and optionally provides the facility for on-board liquid-to-air heat exchanger system, or off-board cooling using an external heat exchanger system.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention pertains to the field of cooling electronic systems. More particularly, the invention pertains to methods of cooling electronics using circulating liquid.

Description of Related Art

Electronic systems that involve a significant amount of heat generation as part of their functionality, or are deployed in an area that subjects them to environmental contamination, or are deployed in areas that require a low acoustical noise signature, oftentimes require liquid cooling. Liquid cooling also can provide the opportunity to significantly reduce overall system size and cost.

Liquid cooling can be realized via several different methods. For example, heat that is dissipated into the local system environment via convection can be transferred to a localized air-to-liquid heat exchanger. Alternatively, heat from electronic components can be transferred directly to liquid coolant via conduction.

When conduction cooling is employed, the general state of the art is to use assemblies that are plumbed in place to the host system's liquid coolant distribution and management system. Such assemblies are typically difficult to repair after a malfunction as they have to be disconnected from the cooling system.

Condensation is a risk in liquid cooled applications where the coolant is supplied from a source that provides coolant at temperatures below the dew point. This can cause sensitive electronic parts to fail and leaves the system unserviceable. Adequate condensation mitigation techniques should be in place to prevent condensation happening in the vicinity of electronic components.

Likewise, the sub-system cabinet these assemblies are contained within is highly customized, providing limited flexibility regarding system expansion or upgrade. With power conversion systems in particular, the ability for a flexible, easy-to-maintain and cost effective architecture is highly desirable. Flexibility areas include setting the amount of power available for a given application, the liquid cooling system, input power management and distribution system, output power management and distribution system, and administrative functions.

SUMMARY OF THE INVENTION

The scalable liquid cooled power system of the invention provides a system architecture using a number of modularized, hot-plug, hot-swap, and scalable liquid-cooled power conversion modules mounted on mating mounting assemblies. A modularized, scalable liquid coolant manifolds and liquid cooling management system provides coolant circulation through the power conversion modules. The system optionally includes a highly scalable system control and administration system, and optionally provides the facility for on-board liquid-to-air heat exchanger system, or off-board cooling using an external heat exchanger system.

DETAILED DESCRIPTION OF THE INVENTION

As shown in dashed lines in the block diagram ofFIG. 1, the Modular Scalable liquid-cooled power system is built around the following major functional blocks:I. Input power connection and input power internal distribution systemII. Modular—blind mate, hot plug power conversion modules configured as blocks. In general, the scalable liquid cooled power system is set to support modular power converters in blocks of up to eight (8) modules13a. . .13n,although other cluster sizes are possible.III. Output power connection and output power internal distribution systemIV. Liquid coolant systemV. Control and administration systemVI. Optional liquid-to-air heat exchanger system

FIG. 1presents how these blocks are configured for the system.

Block No. I, the Input Power Connection and Distribution System, comprises an input power connection point2, which accepts the input power connection1of a size and amperage appropriate to the power being delivered. This power connection is then broken into separate feeds14a,14b,14c. . .14n,by the Input Power Internal Distribution System5. The individual feeds14a,14b,14c. . .14neach feed one of the individual power modules13a,13b,13c. . .13n.

FIG. 2shows a detail of block I. This arrangement provides for practical sizing of AC input conductors1, allowing for extreme versatility of the main AC input feeder, where this can be cables or bus bars. Intermediate cables21are sized to provide cordage that is manageable from the weight, bend radius and cost aspects. Other controllers may be linked in through connections22.

Block No. II comprises a plurality of Modular—blind mate, hot plug power conversion modules13a,13b,13c. . .13n,configured as blocks. The power conversion modules13a-13nare liquid cooled through coolant from the coolant connection distribution and management system16by supply line8and coolant return line9. Input power is supplied to each module13a-13nby individual feeds14a-14n,and output power produced by the modules13a-13nis supplied to output power internal distribution system10in functional block III, discussed below, through individual outputs15a,15b,15c. . .15n.The modules13a-13nare connected to a control bus7from system controller4, as will be discussed in greater detail below.

FIGS. 3ato 3dpresent top, side, front and back views of a typical module30, which can be used interchangeably as any of the modules13a-13nshown inFIG. 1. As shown inFIGS. 3aand 3c, the back panel38of the case of each module30has blind-mate connectors for power input34, power output31and control35. The module30also has connectors for coolant input32and coolant output33on the back panel38, through which coolant can circulate. The front panel39of the module30can be fitted with handles36and fixing screws37, as is conventional in rack-mount electronics.

FIG. 11shows a cabinet mounting assembly40for use with the module30detailed inFIGS. 3a-3c,with a module30partially inserted into the assembly40. The mounting assembly40has a shelf portion49for supporting the module30. Threaded connectors47are provided into which the fixing screws37on the front panel39of the module30can be screwed to secure the module30in the mounting assembly40after the module30has been fully inserted into the mounting assembly40.

A back plane48of the mounting assembly40has blind-mate connectors41-45which match the blind-mate connectors31-35on the back panel38of the module30. Through this arrangement, when the module30is fully seated in the mounting assembly40by being slid completely to the rear, the connectors31-35on module30make secure connection to connectors41-45on mounting assembly40.

In this way, coolant from the coolant connection distribution and management system16is supplied to module30through coolant supply line8to liquid coolant input connector42on the mounting assembly40and then through liquid coolant input connector32to module30. Returned coolant from module30exits through liquid coolant output connector33into liquid coolant output connector43, and then back to the coolant connection distribution and management system16through coolant return line9.

One of the power input lines14a-14nwould be connected to power input connector41on the mounting assembly, which would supply power to module30through mating power input connector31. Power output from module30would be supplied to power output connector34, which would mate with power output connector44on the mounting assembly40, which in turn would be connected to one of the power output lines15a-15n.

Finally, control signals from system controller4would be supplied on control line7to control connector45on the mounting assembly40, which mates with control connector35on the module30.

It will be understood that the specific connectors and connections shown in the figure are for illustrative purposes, and alternative or additional connectors may be provided, and the connectors arranged in different arrangements, within the teachings of the invention.

FIG. 4shows a rear view of an 8-unit cluster of mounting assemblies40a-40h.Each of the mounting assemblies40a-40hhas a coolant input connector42and coolant output connector43. All of the coolant input connectors42are fed by coolant supply manifold8running along the back of the cluster, and all of the coolant output connectors43feed into coolant return manifold9. Each of the mounting assemblies40a-40hhas its power output connectors44, with the positive DC+ connected to bus53and the negative DC− connected to bus54. The power input connectors41on each mounting assembly40a-40hcan be connected in parallel, or individual lines14a-14hprovided as inFIG. 1. Finally, each mounting assembly40a-40hhas its control input45available for connection to the system controller4. If desired, the control inputs45can be daisy chained together or connected in parallel to a communications bus, as is known to the art.

Block No. III comprises the output power connection point11and output power internal distribution system11. Power from the individual power conversion modules13a-13nis supplied to the output power internal distribution system11through lines15a-15n.The combined power of the power conversion modules13a-13nis supplied to the output power connection point11, which then supplies output power12to external components as needed.

FIG. 5provides a schematic depiction of block III, in an example embodiment with eight modules. In this example, the output power lines15a-15hfrom the modules each comprise a positive (DC+) and negative (DC−) wire. The DC+ wires from lines15a-15hare combined in power collection system10into a single line51, which supplies DC+ bus53in the system DC connection point11, and this bus53provides positive voltage to the system power output12. Similarly, The DC− wires from lines15a-15hare combined in power collection system10into a single line52, which supplies DC− bus54in the system DC connection point11, and this bus53provides negative voltage to the system power output12.

Block No. IV is the Liquid coolant system, in which the Coolant Connection, Distribution and Management System16supplies coolant to coolant supply manifold8, and accepts the warmed coolant back through coolant return manifold9. The Coolant Connection, Distribution and Management system16can be monitored and controlled by the system controller4through a Cooling System Control Interface6.

As depicted inFIG. 6, coolant supply manifold8is preferably built up of modular scalable manifolds65aand65bthat can be assembled together to form the manifold8. Similarly, coolant return manifold9is preferably built up of modular scalable manifolds66aand66bthat can be assembled together to form the manifold9. Also shown inFIG. 6are optional flow control solenoid63, controlled by line64from the cooling system control interface6, and optional pressure sensor61which sends pressure data by line62to the cooling system control interface6. The cooling system control interface6is controlled by or reports back to the system controller described in Block No. V, below.

Block No. V, the Control and administration system, consists of an electronic power system control module4that communicates over module control line7to the power converter modules13a-13n.The module control line7is preferably a serial digital communication bus operating a communications protocol known to the art, such as the Controller Area Network (CAN) BUS protocol.

FIG. 7aprovides detail of the control system of Block V. As depicted inFIG. 7, the power system controller4acts as a portal for communication with the external host70through the external system control interface3. The external host70can be connected to the system control interface3via one or more or a combination of serial digital, parallel digital, or analog signal connections71. The connections may be wired or wireless, and might be connected through a local area network (LAN) or wide area network (WAN), or through a global network such as the Internet or private networks. The controller also administers the power conversion modules via a series connected serial digital bus, such as the aforementioned CAN bus.

The controller4also acts to control the liquid coolant system through either a control link6to the coolant connection, distribution and management system16, through control of flow valves63connected to the power module distribution and collection manifolds described inFIG. 6. The controller4can also collect information regarding coolant system pressure through the same link6from the pressure sensor61depicted inFIG. 6. Optionally, the controller4can monitor and/or control an optional heat exchanger through heat exchanger control interface5.

FIG. 7bshows a functional data flow diagram for the power system controller4. The external system control interface3may be connected to an Ethernet Jack72, which routes data to and from an Ethernet transceiver73. The Ethernet transceiver73communicates bidirectionally with a microcontroller74, so that commands can be received from, and data sent to, the external system controller70.

To send commands to, and receive data from, the power conversion modules13a,13b. . .13n,the microprocessor communicates bidirectionally with a CAN transceiver75. The CAN transceiver75is connected to a CAN BUS jack76, into which the control bus7is plugged. All of the power conversion modules13a-13nare connected to the control bus7through a CAN BUS jack77, through which a CAN transceiver78sends and receives data from the bus7. The CAN transceiver78is bidirectionally connected to a microprocessor79in the power conversion module13a-13n,which controls the module and measures various parameters as known to the art.

Block No. VI is an Optional liquid-to-air heat exchanger system. This system provides a means of dissipating heat that is generated by the power conversion process from the coolant connection distribution and management system16. Depending on system climatic requirements, this heat exchanger can be configured to utilize passive convection/radiation or active refrigeration.

FIGS. 8a-8cdepicts an example of a heat exchanger sized to accommodate a power system that produces 500 kW of DC power and operates in an ambient temperature of up to 50° C.

The heat exchanger80inFIGS. 8a-8cis coupled to the coolant connection, distribution and management system16. The heat exchanger80preferably has an on board coolant reservoir85and pump86. The pump86pumps coolant from the reservoir85to the to the coolant connection, distribution and management system16, which distributes it through the coolant supply manifold8as described above.

Coolant which was heated by the power conversion modules13a-13nis returned via coolant return manifold9to the coolant connection, distribution and management system16, which sends the coolant externally to the heat exchanger80to discharge heat in the coolant into the ambient environment.

The heat exchanger80uses two liquid-to-air heat exchangers81and82operating in series to dissipate the heat. Operation of these heat exchangers81and82is optimized through the use of forced air cooling, here shown as a fan83powered by motor84, in which air is drawn through the heat exchangers81and82, cooling the coolant, and then is exhausted through the top of the external heat exchanger80. After passing through the two heat exchangers81and82, the coolant is returned to the reservoir85, from which pump86will pump it back to the power system to complete the coolant system circuit. Alternatively, the coolant from the heat exchangers81and82could go directly to pump86, instead of to the reservoir85, and the reservoir85would be used to maintain the level of the coolant supply as needed. This allows the external heat exchanger80to provide for the coolant flow needs of the power system.

When taken all together, the scalable liquid cooled power system can be configured to serve needs as low as 15 kW (or lower), or as high as 500 kW in a single 19″ standard NEMA cabinet.

FIG. 9presents a sample implementation for a 500 kW system.FIG. 10shows the elements shown inFIG. 9with a transparent view.

In the example ofFIGS. 9 and 10, there are two cabinets: a rack90for the power conversion modules91, which is preferably a 19″ standard NEMA cabinet, and an external heat exchanger92as described above in the discussion ofFIG. 8.