Title:
Integrated Computer Equipment Container and Cooling Unit
Kind Code:
A1


Abstract:
A shipping container having an interior and a plurality of electronic equipment modules disposed within the interior of the container is cooled by an air conditioning unit adapted to be disposed within the interior of the container. The cooling can be assisted or assumed by use of an air side economizer cycle, or by use of a water side economizer cycle. The electronic equipment may include computing equipment and electronic data storage equipment.



Inventors:
Monk, Brian (St. Laurent, CA)
Meldrum, Iiye (Terrebonne, CA)
Application Number:
12/484838
Publication Date:
12/10/2009
Filing Date:
06/15/2009
Primary Class:
Other Classes:
62/238.1, 165/56
International Classes:
F24F1/04; F24F13/02; F24F13/08; F25B27/00
View Patent Images:



Foreign References:
JPH049559A1992-01-14
Other References:
English translation of JP 04009559A Abstract
Primary Examiner:
ATKISSON, JIANYING CUI
Attorney, Agent or Firm:
Cantor Colburn LLP - Carrier (Hartford, CT, US)
Claims:
We claim:

1. A modular computer equipment center comprising: a shipping container having an interior; a plurality of electronic equipment modules disposed within the interior of said container; an air conditioning unit disposed in the interior of said container, said air conditioning unit having a casing having a forward wall facing said plurality of electronic equipment modules, a first side wall extending perpendicularly to the forward wall, and an aft wall opposite the forward wall, said air conditioning unit having a width that is less than a corresponding width of said container whereby an air plenum is formed between the first side wall of said casing and a side wall of said container; and an air side economizer circuit associated with said container and coupled to said air conditioning unit for cooling said interior of said container in part using air from external said container.

2. The modular computer equipment center as recited in claim 1, wherein said air side economizer circuit comprises: an exhaust air vent disposed in a wall of said container; an intake air vent disposed in a wall of said container; a closeable exhaust air damper in flow communication between the atmosphere external said container and the atmosphere internal said container, said flow communication being through said air exhaust vent; and a closeable intake air damper in flow communication between the atmosphere external said container and said air conditioning unit, said flow communication being through said air intake vent.

3. The modular computer equipment center as recited in claim 2, wherein said air side economizer circuit further comprises a recirculation air damper in flow communication with an inlet vent of said air conditioning unit for restricting airflow from interior said container to said air conditioning unit.

4. The modular computer equipment center as recited in claim 1, wherein said container comprises an intermodal container.

5. The modular computer equipment center as recited in claim 2, wherein said exhaust air damper is in flow communication with a portion of said container housing said plurality of electronic equipment modules.

6. The modular computer equipment center as recited in claim 1, wherein said air side economizer circuit is controlled in part using data collected by an external temperature sensor positioned outside said container.

7. The modular computer equipment center as recited in claim 2, wherein said air side economizer circuit is operable using a supply fan of said air conditioning unit and does not include a return fan.

8. The modular computer equipment center as recited in claim 2, wherein at least one of the exhaust air damper and the intake air damper is actuated by control of a controller.

9. A modular computer equipment center comprising: a shipping container having an interior; a plurality of electronic equipment modules disposed within the interior of said container; an air conditioning unit disposed in the interior of said container, said air conditioning unit having a casing having a forward wall facing the plurality of electronic equipment modules and a first side wall extending perpendicularly to the forward wall, said air conditioning unit having a width that is less than a corresponding width of said container whereby an air plenum is formed between the first side wall of said casing and a side wall of said container; and a water side economizer circuit coupled to said air conditioning unit for providing cooling fluid thereto.

10. The modular computer equipment center as recited in claim 9 wherein said water side economizer circuit comprises: a heat exchanger coupled to said air conditioning unit; a passive fluid cooler coupled in flow communication with said heat exchanger for providing cooling fluid to said air conditioning unit; one or more valves configured to divert an amount of flow between said passive fluid cooler and said heat exchanger.

11. The modular computer equipment center as recited in claim 9 wherein said container comprises an intermodal container.

12. The modular computer equipment center as recited in claim 9, wherein said water side economizer circuit is controlled in part using data collected by an external air temperature sensor.

13. The modular computer equipment center as recited in claim 9, wherein said water side economizer circuit is controlled in part using data collected by a passive fluid cooler temperature sensor.

14. The modular computer equipment center as recited in claim 9, wherein said water side economizer circuit is controlled in part using data collected by an external humidity sensor.

15. The modular computer equipment center as recited in claim 9, wherein said passive cooler includes one of a water tower, a river, a lake, and a reservoir.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of International Patent Application No. PCT/US09/39873, filed Apr. 8, 2009, which claims the benefit of U.S. Provisional Application No. 61/050,502, filed May 5, 2008. International Patent Application No. PCT/US09/39873 is incorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention relates generally to transportable modular computer and information technology equipment centers, more particularly, to a transportable modular computer and information technology center having a cooling unit integrated therewith.

BACKGROUND OF THE INVENTION

Portable modular data centers are increasingly being used to provide additional computing and electronic storage data capability without the cost and time delay associated with the construction of a stationary data center. Such modular data centers typically house a plurality of electronic modules, either rack-mounted or shelf-mounted, within a transportable container. The electronic modules may be disposed on both sides of a central aisle extending the length of the container so that humans may access the equipment. Examples of the electronic modules include computer processors, storage modules such as random access memory, disc drives, compact discs, video disks and other computer equipment and electronic information storage devices. The transportable container may be an intermodal shipping container capable of being transported by truck, by rail car or by ship, or even by plane. To facilitate global portability, the container may conform to International Standard Organization (ISO) container manufacturing standards.

For example, U.S. Pat. No. 7,278,273 discloses a modular data center housed in an ISO compliant intermodal shipping container. The modular data center includes at least one computing module including a shipping container and a plurality of computing systems mounted on racks or shelves within the shipping container and configured to be shipped and operated within the shipping container. The modular data center also includes an additional shipping container housing a temperature control system for providing chilled air to one or more of the containers housing the computer modules.

The multitude of electronic modules disposed on racks or shelves housed within a data center enclosure collectively generate a significant amount of heat, for example, between 50 kW and 400 kW of sensible (dry) heat, during operation. Release of this heat into, and subsequent accumulation of the heat in the environment within the enclosure results in temperatures that could adversely impact the performance, reliability and useful life of the electronic modules and components thereof. Therefore, it is desirable to remove the heat produced by the electronic modules from the environment within the data center enclosure. For example, U.S. Pat. No. 7,365,973 discloses a cooling system for a data center wherein chilled coolant from an external source, such as a chiller unit, is circulated through a plurality of cooling racks positioned at selected locations within the data center enclosure for cooling air within the enclosed environment by circulating that air via fans mounted in the cooling racks through heat exchangers, also mounted in the cooling racks, in heat exchange with the chilled coolant.

SUMMARY OF THE INVENTION

An air conditioning unit is adapted to be installed in a shipping container having an interior and a plurality of electronic equipment modules disposed within the interior of the container. The air conditioning unit includes a casing having dimensions sized to be disposed within the interior of the shipping container. The casing has a forward wall facing the plurality of electronic equipment modules and a first side wall extending perpendicularly to the forward wall, and defines an interior chamber. An air inlet is provided in the first side wall opening in flow communication to the interior chamber and an air outlet in the forward wall, which is perpendicular to the first side wall, opening in flow communication to the interior chamber. An air mover is disposed within the interior chamber. The air mover has an inlet in flow communication with the air inlet and an outlet in flow communication with the air outlet. A heat exchanger is disposed within the interior chamber upstream with respect to air flow of the air mover for cooling the air flow passing through the interior chamber. In an embodiment, a mist eliminator may be disposed within the interior chamber downstream with respect to air flow of the heat exchanger. The mist eliminator may include a steel mesh screen.

To facilitate the return of air flow from the interior of the container, the casing of the air conditioning unit has a width that is less than a corresponding width of the container whereby an air plenum is formed adjacent the first side wall of the casing of the air conditioning unit when the air conditioning unit is disposed within the container. In an embodiment, the air conditioning unit is disposed within an intermodal ISO container. In an embodiment, the ISO container has a width of about 8 feet and the casing of the air conditioning unit has a width of about 6 feet.

At least one flow balancing plate may be disposed at the air inlet to the air conditioning unit upstream with respect to air flow of the heat exchanger for selectively distributing the air flow pass into the heat exchanger. In an embodiment, the perforated plate has a plurality of selectively sized and selectively arrayed openings therein. An air filter rack may be disposed at the air inlet to the air conditioning unit upstream with respect to air flow of the heat exchanger.

Economizer cycles can reduce the cooling burden of the air conditioning unit by using passive cooling sources. In one embodiment, an air side economizer circuit circulates external air through the container 20. In another embodiment, a water side economizer circuit is utilized.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the invention, reference will be made to the following detailed description of the invention which is to be read in connection with the accompanying drawing, where:

FIG. 1 is a perspective view, partly in section, of a modular data center and air conditioning unit housed in a shipping container;

FIG. 2 is a first perspective view of an exemplary embodiment of the air conditioning unit shown in FIG. 1;

FIG. 3 is a second perspective view of an exemplary embodiment of the air conditioning unit shown in FIG. 1;

FIG. 4 is a plan view looking down upon the air conditioning unit of FIG. 2;

FIG. 5 is a side elevation view taken along line 4-4 of FIG. 4;

FIG. 6 is a side elevation view taken along line 5-5 of FIG. 5; and

FIG. 7 is a schematic diagram of an exemplary control system associated with the air conditioning unit.

FIG. 8 is a plan view looking down upon an alternate embodiment of the modular data center and air conditioning unit housed in a shipping container, illustrating apparatus associated with an air cooling economizer cycle.

FIG. 9 is a simplified schematic diagram illustrating apparatus associated with a water cooling economizer cycle, according to an alternate embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, there is depicted an exemplary embodiment of a modular data center 10 including a plurality of electronic equipment 12 disposed on shelves or racks housed in a shipping container 20 and an air conditioning unit (ACU) 30 housed in an aft portion of the shipping container 20. The electronic equipment may, for example include, but is not limited to, computer servers, computer processors, storage modules such as random access memory, disc drives, compact discs, video discs and other computer equipment and electronic information storage devices. The electronic equipment may be organized in electronic modules 14 that may be arranged in rows 16 disposed on both sides of a central aisle extending the length of the container or in any other desired arrangement permitting human access to the equipment. A container access door 15 may be provided in the aft wall of the container 20. Additional container access doors may be provided in other walls of the container if desired.

The shipping container 20 may be an intermodal shipping container capable of being transported by truck trailer, rail car or ship. In an embodiment, the container 20 may conform to International Standardization Organization (ISO) container manufacturing standards. Typically, ISO containers have a width of 8 feet, a height of 8½ feet, and a length of 40 feet, although other lengths, shorter and longer, are common. However, containers of various other combinations of height, width and length may be used.

The ACU 30 has a casing having a first side wall 32 on the air inlet side of the ACU 30, a forward wall 34, a second side wall 36 opposite the first side wall, and an aft wall 38 opposite the forward wall 34, and defines an interior chamber 33 therein. The ACU casing has a height, h, compatible with the height, H, of the container 20 and a depth, d, substantially less than the length of the container 20. However, the ACU casing has a width, w, that is less than the width, W, of the container 20, such that when the ACU 30 is positioned within the interior of the container 20, a return air plenum 25 is formed between the air inlet side wall 32 of the ACU 30. As will be explained in further detail hereafter, to remove heat from the environment within the interior of the container 20, air from within the interior of the container 20 is drawn by air movers within the ACU 30 through the air plenum 25 into and through the ACU 30 and discharged therefrom through the louvered air outlets 35 in the forward wall 34 of the ACU 30. In passing through the ACU 30, the air passes in heat exchange relationship with a chilled coolant provided from a source (not shown) external of the container 20, whereby the air is cooled, typically to a temperature in the range of about 55° F. (about 12.8° C.) to about 75° F. (about 23.9° C.), and the heat removed from the air is transferred to the coolant and discharged externally of the environment within the interior of the container 20.

Referring now to FIGS. 2-6, in particular, the air conditioning unit 30 includes an upper ACU module 30U and a lower ACU module 30L disposed in a stacked array. Each ACU module includes at least one air mover 40, a heat exchanger 50 and a mist eliminator 60. The ACU module may also include an air filter 70. The stacked array of ACU modules 30U and 30L is, as noted previously, disposed in the aft portion of the container 20 with the air inlet side wall 32 of the ACU 30 facing the inlet air plenum 25 defined between the air inlet side 30 and the opposed inside surface of the container 20.

The air movers 40 of the upper and lower ACU modules 30U, 30L are disposed in the chamber 33 extending along the side 36 of the ACU 30 opposite the air inlet side wall 32 of the ACU 30. Each of the air movers 40 may include at least one plenum blower, such as, for example, a centrifugal fan, having its inlet in flow communication with the air inlet plenum 25 and its outlet in flow communication with a respective one of the air outlets 35 in the forward wall 34 of the ACU 30. Each plenum blower 40 may be driven by an electric motor 42 operatively associated therewith, either through a belt drive or a direct mechanical connection. Each electric motor 42 is driven via a motor drive 44, which may be fixed frequency drive or a variable frequency drive 44 associated with an electric service/supply panel 46 adapted to be connected to an external electric power source.

If driven by a variable frequency drive, each motor 42 may be a variable speed motor whereby the speed of the motor 42 may be selectively varied to vary the air flow capacity of its associated blower 40 to match the cooling demand. In this case, each plenum blower 40 may be sized to provide 100 percent of the required cooling capacity at maximum design demand. By over sizing each blower 40 and providing variable speed capability, air mover redundancy is provided. In the event that one (or more) blower(s) is out of operation, maximum design cooling operation may still be met by the remaining active blowers. A shutoff damper assembly 48 may be provided in operative association with each of the plenum blowers 40 to permit a failed blower 40 to be isolated by closing the dampers of the shutoff damper assembly 48 to prevent air flow into the failed blower.

Each heat exchanger 50 is disposed within the ACU 30 so as to extend along the air inlet side 32 of the ACU 30, downstream with respect to air flow of the air inlet opening in the air inlet side wall 32 of the ACU 30 and upstream with respect to air flow of the plenum blower 40. Each heat exchanger 50 may include one or more heat exchanger tube banks arranged in parallel with respect to coolant flow through the tubes thereof and in series with respect to the flow of air over the tubes thereof. Each tube bank is connected in a conventional manner to an external supply of chilled coolant (not shown), such as, for example, but not limited to, chilled water from a chiller, or chilled refrigerant from a refrigerant condensing unit disposed external of the container 20, or chilled refrigerant cooled in an external water tower condenser. In operation, chilled coolant is pumped through the tubes of the heat exchanger 50 to cool and remove heat from air drawn by means of the plenum blowers 40 from within the compartment of the container 20 housing the electronic equipment 12, through the air plenum 25, over the tubes of the heat exchanger 50, and through the blowers 40 to be discharged therefrom through the louvered air outlets 35 back into the compartment of the container 20 housing the electronic equipment 12. In this manner, heat produced within the container 20 due to operation of the electronic equipment is removed from the closed environment within the interior of the container 20 and transferred to the coolant passing through the tubes of the heat exchanger 50. The warmed coolant having traversed the tubes of the heat exchanger 50 is returned to the external source of chilled coolant whereby the heat produced due to the operation of the electronic equipment is effectively rejected from the environment within the container 20.

In an alternative embodiment, the modular data center 10 includes an air side economizer circuit. The air side economizer circuit, during operation, eases or ceases the burden on the external supply of chilled coolant (not shown) to cool the air in the container 20. Referring to FIG. 8, the apparatus for the air side economizer circuit 11 includes an exhaust air vent 27 and an associated exhaust air damper 22, and an intake air vent 28 and an associated intake air damper 24. The exhaust air vent 27 and intake air vent 28 are each openings in a wall of the container 20 for allowing air to exit the interior of the container or flow into the container, respectively. A grill might also be attached at the vents, for instance, to keep out intruders, such as persons or non-human animals.

Each respective damper 22 and 24 is positioned in flow communication, through the air vents 27 and 28, between the air internal to the container 20 and the air external to the container 20. This position can be achieved by placing the dampers 22, 24 directly in the respective vent 27, 28, thereby aligning the dampers 22, 24 with the wall. This position can also be achieved by attaching the dampers 22, 24 directly to the respective vent 27, 28. Also, this position can be achieved by attaching each of the dampers 22, 24 to the respective vent 27, 28 indirectly, such as by using a duct to connect between them.

Intake air vent 28 is shown in FIG. 8, with its associated intake air damper 24, situated in the aft wall of the container 20 and/or the aft wall 38 of the air inlet side of the ACU 30, in order to provide a closeable path to take air external to the container 20 into the air conditioning unit. Through air vent 28 and air damper 24, blowers 40 can draw air into the ACU 30 and discharge it therefrom through the louvered air outlets 35 in the forward wall of the ACU 30. Air circulates through the portion of the container 20 housing the plurality of electronic equipment 12. Air is discharged from the container 20 through air vent 27 and its associated air damper 22, which provide a closeable path from the container 20 to the outside. The air vent 27 and air damper 22 are situated at a wall of the container 20 in order to promote air circulation over the electronic equipment from the ACU 30. In FIG. 8, the placement is at a side wall shared by the plenum 25, except in the portion of the container 20 housing the plurality of electronic equipment 12.

Positioning the intake air vent 28 and its associated damper 24 in this close proximity to blower(s) 40 increases the draw of outside air into the air conditioning unit 30 and blower 40. When the damper 24 opens, negative pressure in the plenum 25 is relieved, causing the air pressure at the exhaust air damper 22 to change from negative to positive, which creates the pressure gradient required to exhaust the heated airflow. In this embodiment, the supply fan(s) (i.e. blowers 40), which supply air in the air conditioning unit 30 to the rest of the container 20, are sufficient to circulate external air into the container, around the container, and out through the exhaust air damper 22 without the use of any additional return fan, such as one positioned to assist blowing air out of the container 20.

A recirculation air damper 71 can optionally be used to further prevent air recirculation. Preventing air recirculation using the recirculation air damper 71 also reduces a need to use a return fan. The recirculation air damper 71 can be positioned at an ACU inlet vent 73 in order to close the pathway for air flow from the plenum 25, through the ACU inlet vent 73, into the air conditioning unit 30. Closing the ACU inlet vent 73 reduces or prevents air circulated from the air conditioning unit 30 through the container 20 from being recirculated through the air conditioning unit 30. In this embodiment, the more air tight the plenum 25 is, the more efficient is the circuit. For instance, closing the gap 112 shown in FIG. 8 seals air exiting the air conditioning unit 30 through the louvered ducts 35 from being back drawn through a plenum inlet vent 77 and out of the container 20 through the exhaust air damper 22.

Alternatively, the recirculation air damper 71 can be positioned to close a pathway through a plenum inlet vent 77 for air flow from the portion of the container 20 housing the plurality of electronic equipment 12 to the plenum 25. In this latter position, the recirculation air damper prevents air from exiting into the plenum 25, thereby eliminating extra area for air to flow and possibly leak back into a path of recirculation. Closing the recirculation air damper 71 at either ACU inlet vent 73 or plenum inlet vent 77 increases the draw of air through the intake air damper 24 and forces air to exit through the exhaust air vent 27. Again, however, closing gap 112 will help prevent air exiting the air conditioning unit 30 through the louvered ducts 35 from short circuiting its way back to the air intake side of the air conditioning unit 30 by way of plenum 25. Coordinating the use of the recirculation damper 71 at both vents 73 and 77 can also prevent leaking to assure air recirculation is 100% prevented.

Intake air vent 28 and intake air damper 24 can be positioned alternatively on a wall of the container to provide flow communication between the air external to the container 20 and the plenum 25. In this case, the recirculation air damper 71 can be positioned to close the air pathway through the plenum inlet vent 77. Closing air flow through the ACU inlet vent 77 increases the draw of air through the intake air damper 24 and the exhaust of air through the exhaust air damper 22. Furthermore, this positioning of the intake air vent 28 and its associated air damper 22 can be useful when using the air side economizer cycle 11 simultaneously with the heat exchanger 50. External air that is cooler than the air exiting the container 20 through the exhaust air vent 27 can be further cooled as it enters the air conditioning unit 30 at ACU inlet vent 73 and passes thoroughly over the heat exchanger 50.

Air dampers 22, 24 and their associated air vents 27, 28 can be positioned in alternative locations or on alternative walls within the portion of the container 20 housing the plurality of electronic equipment 12. For instance, the exhaust air damper 22 and the air vent 27 can alternatively be situated in the forward wall of the container 20, or in the side wall opposite the one shown holding the air damper 22 in FIG. 8. In each of these cases, closing the recirculation damper 71 positioned at either the vent 73 or the vent 77 promotes the flow of air to exit the container 20 through the exhaust air damper 27 and the exhaust air vent 22.

When the intake air vent 28 and its associated damper 24 intake air directly, or through a duct, to the air conditioning unit 30, closing the recirculation air damper 71 at either the vent 77 or the vent 73 promotes the flow of air to exit the container 20 through the exhaust air vent 27 and its associated damper 22. Closing recirculation damper 71 at the vent 73 eliminates the risk of the blower(s) drawing air from a leak or unsealed path from the plenum 25 to heated air. Also, in this case, the exhaust air vent 27 and its associated damper 22 can be located in a wall of the container 20 at the plenum 25 to exhaust air from the plenum 25 rather than the portion of the container 20 housing the plurality of electronic equipment 12.

To further help promote air flow exiting the container through exhaust air vent 27 and exhaust air damper 22, for instance, when complete recirculation is not achieved, an optional return fan 75, such as a centrifugal fan, can be used. The return fan 75 is positioned in flow communication with the exhaust air damper 22. The return fan 75 may be driven by an electric motor 79 operatively associated therewith, either through a belt drive or a direct mechanical connection. The electric motor 79 may be driven by a fixed frequency drive or a variable frequency drive (not shown) associated with an electric service/supply panel (e.g. the electric service/supply panel 46 illustrated in FIG. 4) adapted to be connected to an external electric power source.

If driven by a variable frequency drive, the motor 79 may be a variable speed motor whereby the speed of the motor 79 may be selectively varied to vary the air flow capacity of the return fan 75 to match the cooling demand.

Each air damper 22, 24, 71 is opened or closed by an actuator 26 operatively associated therewith. Each actuator 26 is connected to an external electric power source (not shown), possibly through an electric service/supply panel (e.g. the electric service/supply panel 46 illustrated in FIG. 4) adapted to be connected to the external electric power source.

In operation, when the air temperature external to the container 20 is below a predetermined external air temperature set point, the air dampers 22, 24 open. Air movers 40 draw air into the ACU 30 through air damper 24, circulate the drawn air amongst the electronic equipment 12 in the container 20, and expel the drawn air through the air damper 22. When a return fan 79 is used, it further blows air out of the container 20 through the exhaust air damper 22. When a recirculation air damper 71 is used, it operates in coordination to achieve the desired air flow and the resultant desired cooling. Generally, damper 71 closes when dampers 22 and 24 are open.

The set point can be adjusted as necessary, depending on the amount of heat required to be removed. A typical application might require cooling approximately 300 kW of dry heat, while any amount in the range from 50 kW to 400 kW might be required. The operating speed of the air movers 40 is also adjusted as required depending on the air temperature internal and external to the container 20 and the required amount of heat to be removed from the container 20. As an example, if 300 kW of heat is required to be removed from the container 20, and the external air temperature is approximately 60 degrees Fahrenheit, then the air cooling economizer cycle must intake and expel 30,000 CFM of air in order to deliver air at 87 degrees Fahrenheit and avoid using the external supply of chilled coolant (not shown).

Referring to FIG. 9, a further embodiment includes a water cooling economizer cycle, that, during operation, transfers in part or in whole, the cooling burden from an active coolant chiller 52 to a passive fluid cooler 54. An active chiller synthetically chills. A refrigerant condensing unit is an example. A passive fluid cooler allows heat to be removed from the coolant using natural resources which may be available. Examples of passive fluid coolers include, but are not limited to, water towers, rivers, lakes, and reservoirs.

The active chiller 52 and the passive fluid cooler 54 are located external to the container 20. The active chiller 52 is connected to the tube banks of the heat exchanger 50 in each ACU module 30U, 30L. An active chiller valve 62 exists either inside the ACU 300, or between the ACU 300 and the passive fluid cooler 54. The passive fluid cooler 54 is also connected to the tube banks of the heat exchanger 50 in each ACU module 30U, 30L. A passive fluid cooler valve 64 exists either inside the ACU 300, or between the ACU 300 and the passive fluid cooler 54. Alternatively, valves 62, 64 can be a series of valves to appropriately achieve the same function.

In operation, valves 62, 64 open and close, inversely, to route the chilled coolant to/from the passive fluid cooler 54 or the active chiller 52, depending on the temperature of the air, the temperature of the passively chilled coolant external to the container 20, the temperature of the coolant in the ACU 300, the humidity external to the container, and/or the amount of heat required to be removed from the container 20. By “open and close inversely”, it is meant that when the valve 62 is selectively opened, the valve 64 is closed, and conversely, when the valve 64 is selectively opened, the valve 62 is closed. When cooling is not required, both valves 62, 64 may be closed. For example, if the air temperature external to the container 20 is 58 degrees Fahrenheit, and the ACU 300 requires an inlet coolant temperature of 65 degrees Fahrenheit, then it is economical for the valves 62, 64 to route the coolant exiting the ACU 300 to the passive fluid cooler (e.g., a cooling tower) to be naturally cooled before returning to the container 20. The valves 62, 64 can be self-actuated. Alternatively, separate actuators (not shown) operatively connected to the valves 62, 64 can be controlled separately. If necessary, the self-actuated valves, or each actuator (not shown) can be connected to an external electric power source (not shown), possibly through an electric service/supply panel (e.g. the electric service/supply panel 46 illustrated in FIG. 4) adapted to be connected to the external electric power source. Further, separate heat exchangers may be coupled to the active and passive fluid coolers.

A mist eliminator 60 may be disposed in the path of the air flow passing through the ACU 30. Moisture may enter the closed environment within the container 20 from the outside when humans make entry into the container 20 to access the electronic equipment housed therein. Additionally, moisture may condense out of the air within the closed environment when the air temperature therein drops, such as when the electronic equipment is shut-down, and therefore not generating heat, or the outside temperature drops significantly. Upon start-up of the ACU 30, this condense moisture will be re-entrained into the sir flow and will be removed therefrom before the electronic equipment is booted up. In the exemplary embodiment depicted in the drawing, a mist eliminator 60 is disposed downstream heat exchanger 50 with respect to air flow. Although most of the moisture in the air flow entering the heat exchanger 50 will condense on the outside of the tubes and drain into a condensate pan disposed beneath the heat exchanger 50, the mist eliminator 60 will collect those moisture droplets that may be carried over in the air flow passing from the heat exchanger 50. The mist eliminator 60 will also function to help balance airflow across the heat exchanger 50. The mist eliminator 60 may of conventional design. In an embodiment, the mist eliminator 60 comprises a steel mesh screen.

An air filter rack 70 having a framework supporting one or more air filters may be disposed at the air inlet in the air inlet side wall 32 of the casing of the ACU 30 upstream with respect to air flow of the heat exchanger 50. The air filters function to remove dust, dirt and other debris that may be entrained in the air flow from the compartment of the container 20 housing the electric equipment. Dirt, dust and other debris may be brought into the closed environment within the container 20 when humans enter therein to service, maintain or replace the electronic equipment 12 housed therein. The air filter rack 70 may be of conventional design.

Additionally, one or a plurality of flow balancing plates 80 may be disposed in the ACU 30 upstream of the heat exchanger 50 either in the filter rack 70 or external to the air inlet to the ACU 30. The flow balancing plates 80 may comprise perforated sheets having a plurality of opening therein arrayed in a desired pattern or non-perforated, solid sheets. Those skilled in the art will recognize that the distribution of air flow from the air plenum 25 into the heat exchanger 50 may be selectively adjusted to provide a uniform flow distribution across the face of the air inlet to the ACU 30 by selective sizing and arrangement of the openings in the perforated flow balancing plates 80. If desired, the flow balancing plates 80 may be disposed and supported in the supporting framework of air filter rack.

The ACU 30 may also include a controller 90 for controlling the operation of each of the air conditioning modules 30U and 30L. The controller 90 may be located within the electrical panel for ready access via the container doors 15 at the end of the container 20. Referring now to FIG. 7, in particular, the controller 90 monitors each of the respective discharge air temperature sensors 92 associated with the blowers 40. Each discharge air temperature sensor 92 may be located in the discharge duct of its associated blower 40. The controller 90 also monitors the temperature of the coolant entering and the temperature of the coolant leaving each of the heat exchangers 50 associated with the air conditioning modules 30U and 30L via coolant temperature sensors 98. The controller 90 also controls the variable frequency drives 44 to vary the speed of the fan motors 42 to vary the air flow delivered by each of the blowers 40. The controller 90 also controls the flow of coolant through the respective heat exchangers 50, for example by opening, closing or modulating a coolant flow control valve 94 disposed in the coolant supply line 2 to the respective heat exchangers 50 if the ACU 30 is associated with an external water chiller, or starting and stopping a compressor 96 in conjunction with modulating a refrigerant flow control valve 94 if the ACU 30 is associated with an external refrigerant condensing unit (in which case the compressor may be located off-board the container) or a water tower condensing unit (in which case the compressor may be located on-board). The controller 90 processes the discharge air and the coolant temperature measurement signals received and in response thereto varies the air flow and/or water flow as appropriate to maintain a desired discharge air temperature, typically in the range of about 55° F. (about 12.8° C.) to about 75° F. (about 23.9° C.), as well as to optimize the efficiency of the cooling system, including the external coolant supply device, for example a water chiller or a refrigerant condensing unit. It is to be understood that the controller 90 may vary the air flow delivered by the blower 40 and water flow through the heat exchanger of one of the modules 30U and 30L independently of the other of the modules 30U and 30L.

In conjunction with the optional air cooling economizer cycle, the controller 90 can also monitor the air temperature external to the container 20 via sensor 100. The controller 90 can control the selective opening and selective closing of the air dampers 22, 24, and adjust the speed of each blower 40 to regulate the air temperature inside the container 20 when the external air temperature is below. Furthermore, the controller 90 can control the selective opening and selective closing of recirculation damper 71, as well as the operation of return fan 75, in coordination with the operation of air dampers 22, 24 and blowers 40.

In conjunction with the optional water cooling economizer cycle, the controller 90 can monitor the external air temperature, or alternatively, the coolant in the passive fluid cooler 54 (e.g., water in a lake or river) via sensor 100. The controller 90 can also monitor external humidity via sensor 102 in order to determine the outdoor air enthalpy. The controller 90 processes the external air temperature, the external humidity, the discharge air temperature, and/or the coolant temperature measurement signals received and in response thereto routes the water flow as appropriate between the active chiller 52 and the passive fluid cooler 54 via active chiller valve 62 and passive fluid cooler valve 64. Valves 62, 64 of FIG. 9 are represented in FIG. 7 by flow control valves 94. However, additional valves can be used to increase the source of coolant and the method of cooling the coolant. In an example, when the outside temperature drops below a predetermined external air temperature set point, then the controller 90 closes the active chiller valve 62 and opens the passive fluid cooler valve 64. The controller 90 may modulate the passive fluid cooler valve 64 to maintain the air temperature desired inside the container 20. If the passive fluid cooler valve 64 is fully open, and the controller 90 receives temperature data indicating the coolant exiting the ACU 300 exceeds a predetermined exiting coolant temperature set point, then the controller 90 will gradually close the passive fluid cooler valve 64 while gradually opening the active chiller valve 62, as necessary to maintain the air temperature desired inside the container 20. If the outside temperature is above the external air temperature set point, or the air temperature desired inside the container 20 cannot be maintained, then the controller 90 will turn off the water cooling economizer cycle by closing the passive fluid cooler valve 64 and opening the active chiller valve 62.

The controller 90 may have functional capability to shut down a blower 40 by deactivating its associated fan motor 42 in the event of a sudden drop or complete loss of static pressure, detected by a static pressure sensor (not shown) disposed in association with each blower, such as may occur as a result of a fan belt break or other component failure. The controller 90 may have functional capability to detect condensate build-up in a condensate drain pan 58 beneath each of the heat exchanger 50 and the capability to detect a water leak, either from the heat exchanger itself or from an overflowing condensate drain pan. To do so, the controller 90 may be programmed to monitor a plurality of sensors 91, 93, 95 for example electrical resistance sensor tapes, associated with a condensate drain pan disposed beneath each of the heat exchangers 50 and with the floor beneath the condensate drain pan. If an electrical resistance sensor tape becomes wet, the sensor transmits a signal to the controller 90 indicating the presence of water. For example, a first sensor tape 91 may be disposed in the bottom of drain pan 58 to detect if condensate is present in the drain pan, a second sensor 93 may be disposed near the top rim of the drain pan 58 to detect if the drain pan is filled with condensate, and a third sensor tape 95 may be disposed beneath the drain pan 58 to detect if the condensate has over flowed the drain pan or the heat exchanger has developed a coolant leak.

The controller 90 may also control a reaction to other events, such as unauthorized or accidental access, smoke, high or low temperatures and humidities, failure of any moving part, dirty filters, failure of a part to respond properly to the controller 90, and power failure. Additional sensors, not shown, may be used. Sensors to collect data to be sent to the controller 90 include, but are not limited to, smoke detectors, temperature sensors, water detectors, pressure sensors and mechanical interlock switches. Reaction events vary depending on the event. Some examples include, but are not limited to, the following. In the event of a fan failure, an alert causes other forms of cooling to increase, such as coolant flow opening to maximum. If a belt breaks, the fan motor shuts off while operational fans and coolant flow increase speed. If condensate is detected, it is logged. If excess condensate is detected or a catastrophic leak is detected, an alert is sent, and the ACU 30 is shut down. Air dampers 22, 24 can be opened. If a door is open, the event is logged and cooling increases. A dirty filter causes an alarm. High air humidity causes a reaction to promote condensation, including increasing coolant flow and minimizing fan speeds.

As noted previously, the air conditioning unit 30 is designed with a width, w, that is less than the width, W, of the container 20, such that when the ACU 30 is positioned within the interior of the container 20, a return air plenum 25 is formed between the air inlet side 32 of the ACU 30. Additionally, the air inlet side 32 of the ACU 30 and the air outlet side 34 of the ACU 30 are perpendicular to each other. Thus, as best seen in FIG. 4, air flow through the ACU 30 is therefore in a general U-shaped pattern. The ACU 30 draws in air flow at a high velocity, up to about 600 feet per minute, into the compartment housing the electronic equipment 12 along one side of the interior of the container 20, referred to as the “cold side”, and receives return air at a high velocity, up to about 600 feet per minute, from the compartment housing the electronic equipment 12 along the other side of the interior of the container 20, referred to as the “warm side”. In this manner, adequate cooling air is provided to all of the electronic equipment supported of racks or shelves within the interior of the container 20.

The air conditioning unit 30 is capable of delivering an amount of cooled air flow sufficient to meet maximum cooling demand for a modular data center disposed within a standard ISO shipping container while still fitting entirely within the interior of a standard ISO shipping container. The casing of the ACU 30 may have cutouts and offsets to recess coolant inlet and outlet connections 4 and 6. All protuberances from the ACU 30, such as door handles, door hinges, power connections and the like are within the footprint defined by the width and depth of the ACU 30. For example, the casing of the ACU 30 may have a height, h, of about 8¼ feet, a depth of about 9½ feet and an overall width of about 6 feet. When installed in a standard ISO container, due to the limited width of the ACU 30, the air plenum 25 formed between the air inlet side wall 32 of the casing of the ACU 30 and the facing wall of the container 20 will have a width of about 20 inches, which is large enough to also provide access with the air plenum 25 to service and replace the rack of air filters 70 and flow balancing plates 80.

Additionally, the ACU 30 may be equipped with lifting lugs 21 mounted to the base frame 31 of the ACU 30 for providing members to which a crane or other hoisting device may be attached to permit the ACU 30 to be lifted. The lifting lugs may be removable to facilitate final installation of the ACU 30 into the container 20. The ACU 30 may also be equipped with strap holes 23 and forklift points (not shown) in the base frame 31 of the ACU 30 to facilitate securing the ACU 30 to a forklift truck and maneuvering the ACU 30 during final installation of the ACU 30 into the container 20. The ACU 30 may also include an access door 39 in the aft side wall 38 of the casing of the ACU 30, accessible via opening the container door 15, to provide human access to the plenum blowers 40 and associated fan motors 42, motor drives 44 and the electric supply panel 46. Additionally a pair of removable access panels 88 may be provided in the side wall 36 of the casing of the ACU 30 to permit access to the bearings, gearing and drive system of the plenum blowers 40 and associated fan motors 42. A corresponding access door 18 may be provided in the side of the container to permit access to the access panels 88.

The terminology used herein is for the purpose of description, not limitation. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as basis for teaching one skilled in the art to employ the present invention. While the present invention has been particularly shown and described with reference to the exemplary embodiments as illustrated in the drawing, it will be recognized by those skilled in the art that various modifications may be made without departing from the spirit and scope of the invention. Those skilled in the art will also recognize the equivalents that may be substituted for elements described with reference to the exemplary embodiments disclosed herein without departing from the scope of the present invention.

Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed, but that the disclosure will include all embodiments falling within the scope of the appended claims.