WO2012068235A1

WO2012068235A1 - Cooling system and method

Info

Publication number: WO2012068235A1
Application number: PCT/US2011/060967
Authority: WO
Inventors: Alexander I. Yatskov
Original assignee: Parker-Hannifin Corporation
Priority date: 2010-11-16
Filing date: 2011-11-16
Publication date: 2012-05-24

Abstract

A system for receiving and cooling heat-producing devices, such as battery modules, includes a series of racks in a container, with each of the racks receiving multiple of the heat-producing devices. A cooler cools and recirculates a cooling fluid through a flow path that runs in parallel through the racks, passing through only one of the racks before being recirculated through the cooler. The heat-producing devices may be located in multiple levels around the perimeter of each of the racks, and the racks or levels may swivel. The racks may have screens that provide different amounts of fluid flow resistance at different of the levels of the racks, to even out the amount of cooling provided to heat-producing devices on different levels of the racks. The system may also have an individual fan for each of the racks, to control air flow through the rack.

Description

COOLING SYSTEM AND METHOD

[0001] This application claims the benefit of U.S. Provisional Application

61/414,214, filed November 16, 2010, which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention is in the general field of cooling systems and methods for cooling heat-generating components.

DESCRIPTION OF THE RELATED ART

[0003] Large numbers of heat-producing devices, such as batteries, are often coupled together in the same location. Providing even cooling and access to such devices may be difficult. Uneven cooling can result in reduced performance.

[0004] Improvements generally would be desirable in cooling systems for heat- producing devices.

SUMMARY OF THE INVENTION

[0005] According to an aspect of the invention, a system for cooling heat- producing devices includes: multiple racks, wherein each of the racks has multiple levels, with each of the levels capable of receiving multiple of the heat-producing devices; and a cooler that cools a cooling fluid and recirculates the cooling fluid through a flow path. The flow path passes in parallel through the racks, each part of the flow path passing through only one of the racks before being recirculated through the cooler.

[0006] According to another aspect of the invention, a method of cooling heat- producing devices includes: flowing cooling fluid along a flow path through a container to cool the heat-producing devices; wherein the flow path passes in parallel through the racks, each part of the flow path passing through only one of the racks before being recirculated through the cooler.

[0007] To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The appended drawings show various features of embodiments of the invention.

[0009] Fig. 1 is an oblique view of a cooling system in accordance with an embodiment of the present invention.

[0010] Fig. 2 is an oblique view showing further details of a rack that is part of the cooling system of Fig. 1 .

[0011] Fig. 3 is an oblique showing the rack of Fig. 2, with the heat-producing devices removed.

[0012] Fig. 4 is a schematic view of an alternate embodiment cooling system of the present invention.

[0013] Fig. 5 is an oblique view showing another alternate embodiment cooling system of the present invention.

DETAILED DESCRIPTION

[0014] A system for receiving and cooling heat-producing devices, such as battery modules, includes a series of racks in a container, with each of the racks receiving multiple of the heat-producing devices. A cooler cools and recirculates a cooling fluid through a flow path that runs in parallel through the racks, passing through only one of the racks before being recirculated through the cooler. The heat-producing devices may be located in multiple levels around the perimeter of each of the racks, and the racks or levels may swivel, to allow access to the heat- producing devices. The heat-producing devices may have holes or openings in them, to allow passage of the cooling fluid through the devices, so as to cool the devices. Fluid flow may pass from the outside of the racks into cores at the middle of the racks, cooling the heat-producing devices as the flow passes therethrough. From the cores of the racks the cooling fluid may flow back to the cooler, to be recirculated through the system. The racks may have screens that provide different amounts of fluid flow resistance at different of the levels of the racks, to even out the amount of cooling provided to heat-producing devices on different levels of the racks. The system may also have an individual fan for each of the racks, to control air flow through the rack. The racks may have connectors for electrically connecting all the batteries of a single rack together in series, and for electrically connecting the rack to an electrical bus. The system allows for achieving a good evenness in thermal conditions for each of the heat-producing devices, even in a container that has a large number of racks, with a large number of heat-producing devices in each rack. For example, the system may be able to maintain hundreds of battery modules, in over twenty racks, all within a thermal tolerance of plus or minus three degrees Centigrade.

[0015] Fig. 1 shows a system 10 for cooling heat-producing devices 12, such as battery modules. The system 10 includes a container 14 that encloses all of the battery modules 12. Three sides of the container 14 are shown open in Fig. 1 for illustration purposes, although in ordinary operation all sides of the container 14 will be closed.

[0016] The battery modules 12 shown may each include multiple cells, for example 24 cells electrically connected together in series. As an alternative, other types of heat-producing devices, such as various electronic devices, may be cooled by the system 10.

[0017] The battery modules 12 are located in a series of racks 20 that are in a main space 24 of the container 14. The illustrated embodiment has 26 of the racks 20, although alternatively a greater or lesser number of racks may be employed. In the illustrated embodiment each of the racks 20 has battery modules 12 arrayed around the periphery (perimeter) of the racks 20, at multiple levels of each of the racks 20.

[0018] The system 10 recirculates a cooling fluid through the container 14, to cool the battery modules 12. The cooling fluid in the illustrated embodiment is air, although alternatively the cooling fluid could be another fluid, such as a liquid or another gas. A cooler 30 receives (relatively) warm return air from a plenum 31 between an interior wall 32 within the container 14, and a top wall 34 of the container 14. The cooler 30 cools the air it takes in, and outputs cooler air into the main space into the main space 24, past the battery modules (heat-producing devices) 12 into the cores of the racks 20, up through the cores of the racks 20 into the plenum 31 , and from the plenum 31 back to the cooler 30. The flow path 36 through the system 10 is in parallel through the racks 20, with each part of the flow path 36 passing through only one of the racks 20 before being recirculated through the cooler 30.

[0019] Fans 40 are located in the plenum 31 , at the top of each of the racks 20. The fans 40 are used to pull cooling fluid (air) through the cores of each of the racks 20. The fans 40 may all be substantially identical, although the fans may be run at different speeds to control the air flow through the system 10.

[0020] Figs. 2 and 3 show further details of one of the racks 20. The rack 20 has different levels 52, 54, 56, 58, 60, and 62, each capable of receiving multiple of the heat-producing devices 12. The levels 52-62 are numbered from top to bottom. In the illustrated embodiment each of the levels has six of the heat-producing devices 12, but a larger or smaller number may be employed.

[0021] In the illustrated embodiment, the heat-producing devices 12 have openings 68 in them, so as to allow the cooling fluid to flow through the heat- producing devices 12, from the outside of rack 20 into a core 72 in the middle of the rack 20. From outside the cooling fluid (air) is pulled through the core 72 by the fan 40, which expels the cooling fluid into the plenum 31 (Fig. 1 ), which is over the rack 20.

[0022] With reference to Fig. 3, device-receiving spaces 76 on different of the levels 52-62 provide different resistance to air flow, to allow balance to be

maintained in cooling the devices 12 on different of the levels 52-62. The spaces 76 on different of the levels 52-62 may have different respective screens 82, 84, 86, 88, 90, and 92. The screens 82-92 may have decreasing amounts of restrictiveness to flow of cooling fluid. That is, the screens 82 at the topmost level may be the most restrictive to allowing flow to pass therethrough, with the screens providing less and less flow restriction with each succeeding level below. The screens 82 may be a mesh or may otherwise restrict flow, for example with various numbers and/or sizes of openings therein to restrict flow from outside of the rack 20, past and/or through the devices 12, and into the core 72 of the rack 20. The upper screens 82-86 may have a finer mesh than the lower screens 88-92, or may otherwise provide different flow restriction. By providing greater flow restriction through the upper screens the flow and/or the cooling may be balanced between the heat-producing devices 12 on the different levels of the rack 20.

[0023] The rack 20, or the separate levels 52-62 of the rack 20, may rotate to allow access to the devices 12, for example to swap the devices 12 in and out. The individual levels 52-62 may be mounted on bearings, allowing the levels 52-62 to rotate relative to the rest of the rack 20. Alternatively or in addition the entire rack 20 may be configured to rotate as a unit, for example to rotate relative to the container 14 (Fig. 1 ). The rotation may be constrained by stops to prevent overrotation that might otherwise put strain on electrical connections between the rack 20 and an electrical bus 100. The rotation mechanism may allow rotation in 180 degrees in either direction about a center point, for example in increments of 60 degrees. The electrical bus 100 may be on a wall of the container 14. The heat-producing devices 12 may be batteries that are coupled together in series, and all coupled to the electrical bus 100.

[0024] With reference now to Fig. 4, the fans 40 for each of the racks 20 may have their speeds controlled by a controller (or computer) 120, so as to balance cooling within the system 10. The controller 120 may receive input from temperature sensors 122, which may be placed at various locations throughout the container 14 to monitor temperature. The computer 120 (which may be a computer, or any of a wide variety of controllers of various configurations, with instructions in hardware and/or software) may use the input to change speeds of the individual fans 40 as needed, so as to achieve a desired balance in the temperatures of the various heat- producing devices 12 in the system 10.

[0025] As an alternative to (or in addition to) actively controlling the speed of the fans, the fans 40 may be sized differently, or set to run at different speeds.

However, having the fans 40 be substantially identical and interchangeable will reduce costs by standardizing parts.

[0026] Another alternative for balancing cooling levels is illustrated in Fig. 5, which shows a variant where baffles 140 are located in the plenum 31 . The baffles 140 aid in evening out the air flow paths for the various racks 20 in the container 14.

[0027] The embodiments shown are only a few of the various possible configurations for the system 10. Different numbers and configurations of racks, rack levels, and heat-producing devices may be employed, to give only a few of the examples of variables.

[0028] The system 10 may be able to achieve a good thermal tolerance throughout the container 14. For example it may be possible to achieve a uniformity of temperatures of the heat-producing devices 12 within plus or minus 3 degrees C, for all devices in the container 14. The container 14 may have a height of about 2.5 m not including the cooler 30 (about 4.4 m with the cooler 30 included), a length of about 13.7 m, and a depth of about 2.4 m, but any or all of these values may vary over a wide range.

[0029] Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements

(components, assemblies, devices, compositions, etc.), the terms (including a reference to a "means") used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

Claims

CLAIMS What is claimed is:

1 . A system for cooling heat-producing devices comprises:

multiple racks, wherein each of the racks has multiple levels, with each of the levels capable of receiving multiple of the heat-producing devices; and

a cooler that cools a cooling fluid and recirculates the cooling fluid through a flow path;

wherein the flow path passes in parallel through the racks, each part of the flow path passing through only one of the racks before being recirculated through the cooler.

2. The system of claim 1 , wherein the cooler is an air conditioning unit used for cooling air as the cooling fluid.

3. The system of claim 2, further comprising fans operatively coupled to respective of the racks to pull the cooling air through the racks.

4. The system of claim 3, wherein the fans pull the cooling air through cores of the racks.

5. The system of claim 3 of claim 4, wherein the fans of different of the racks operate at different speeds.

6. The system of any of claims 3 to 5, further comprising a controller operatively coupled to the fans, for controlling fan speeds of the fans.

7. The system of claim 6, further comprising temperature sensors operatively coupled to the controller.

8. The system of any of claims 1 to 7, further comprising a wall that separates a cold side of the flow path that is upstream of the heating-producing devices, from a hot side of the flow path that is downstream of the heat-producing devices.

9. The system of claim 8, wherein the wall is a ceiling within a container, with a plenum between the ceiling and a top wall of the container acting as the hot side of the flow path that returns cooling fluid to the cooler.

10. The system of claim 9, further comprising one or more baffles in the plenum.

1 1 . The system of claim 1 , further comprising multiple fans that pull the cooling fluid through respective of the racks.

12. The system of claim 1 1 , wherein the racks have screens that provide resistance to pulling of the cooling fluid through the racks.

13. The system of claim 12, wherein the screens on different of the levels provide different amounts of resistance.

14. The system of claim 13, wherein the screens on the levels closest to the fans provide more resistance to the flow of the cooling fluid than the screens on the levels farther from the fans.

15. The system of any of claims 1 to 14, wherein the heat-producing devices are battery modules.

16. The system of claim 15, wherein the battery modules on each of the racks are electrically connected together in series.

17. The system of claim 16, wherein the racks are electrically connected together in parallel.

18. The system of any of claims 1 to 17, wherein the heat-producing devices have openings therein that allow flow of the cooling fluid through the heat-producing devices.

19. The system of any of claims 1 to 18, wherein the racks swivel relative to the container.

20. The system of any of claims 1 to 18, wherein individual levels of the racks swivel relative to the rest of the racks.

21 . A method of cooling heat-producing devices, the method comprising: flowing cooling fluid along a flow path through a container to cool the heat- producing devices;