Battery pack jet cooling

Abstract

According to one embodiment, a battery module includes an output connector, a plurality of battery cells coupled to the output connector, and a plurality of nozzles and a spray cooling circuit and system. The battery cell is configured to provide battery energy to a load via the output connector, and is configured to draw power from an external power source via the output connector to charge the battery cell. The nozzle is configured to spray a coolant on the battery cell to transfer heat generated by the battery cell to the sprayed coolant.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to a backup thermal management system for cooling a battery pack. More specifically, embodiments of the present disclosure relate to a system for spraying coolant onto cells in a battery pack as the cells are discharged and / or charged. Background Art

[0002] Lithium-ion batteries are commonly used in the vehicle industry, such as electric vehicles (EVs) and plug-in hybrid vehicles. Lithium-ion battery packs for electric vehicles are designed for vehicle-specific requirements and uses. However, lithium-ion batteries are also becoming popular for IT equipment and data centers as energy storage units to replace UPS systems and lead-acid batteries, and are attracting a lot of attention from the industry.

[0003] Large clusters of computer servers may be maintained in dedicated facilities, typically in rack enclosures. The servers may be used to support the data center industry. The use of battery backup units (BBUs) in place of traditional solutions, such as lead-acid based uninterruptible power supply (UPS) systems, has become increasingly popular. One result of the new role of the BBU in the data center space is the relocation of the BBU from a centralized battery room to the data center IT room. The thermal environment (e.g., temperature) in a data center is generally managed and operated based on the specifications and requirements of the servers (rather than the batteries), or the thermal environment may not be optimized for the BBU and therefore may not be optimized for BBU use.

[0004] In contrast, in the case of a BBU, the battery provides power only when backup power is needed (e.g., there is a power outage to the data center). When backup power is no longer needed (e.g., grid power is restored to the data center), the BBU is recharged. Therefore, the only problem in BBU applications is that thermal management or cooling will only be active during a limited period of time: such as discharging during a power outage and charging after power is restored. Therefore, there is a need for a battery thermal management system that is self-activated during battery charging and discharging in order to ensure that the battery does not overheat.

[0005] In addition, the self-activated thermal management system should be fast enough to avoid thermal overshoot, which can negatively affect battery performance and battery life, and the optimized design should cool all cells uniformly. However, these systems may not uniformly cool the battery cells, which may result in at least some thermal overshoot. Therefore, there is a need for a self-activated thermal management system that uniformly cools the battery in order to maintain battery performance. Summary of the invention

[0006] One aspect of the present disclosure provides a battery module, which includes an output connector; a plurality of battery cells coupled to the output connector, wherein the battery cells are configured to provide battery energy to a load via the output connector and are configured to draw power from an external power source to charge the battery cells via the output connector; and a plurality of nozzles configured to spray a coolant onto the plurality of battery cells to transfer heat generated by the battery cells to the sprayed coolant.

[0007] Another aspect of the present disclosure provides a battery backup unit (BBU), the BBU comprising a group of one or more battery modules, wherein each battery module comprises: an output connector, a plurality of battery cells coupled to the output connector, wherein the battery cells are configured to provide battery energy to a load via the output connector, and are configured to draw power from an external power source to charge the battery cells via the connector, and a plurality of nozzles configured to spray a coolant onto the plurality of battery cells to transfer heat generated by the battery cells to the sprayed coolant.

[0008] Another aspect of the present disclosure provides an electronic rack, the electronic rack comprising a plurality of server blades arranged in a stack, each server blade comprising one or more servers providing data processing services; a power supply coupled to the server blades to provide power to operate the servers; and a battery backup unit (BBU), the BBU coupled to the blade servers to provide backup power to the blade servers when the power supply cannot provide power, wherein the BBU comprises at least one battery module, wherein each battery module comprises: a plurality of battery cells, the BBU draws battery energy from the plurality of battery cells to provide backup power, and a plurality of nozzles configured to spray coolant onto the plurality of battery cells.

[0009] According to the present disclosure, by utilizing spray cooling to self-activate the thermal management system, heat is dissipated quickly enough to avoid thermal overshoot that negatively affects battery performance and battery life; by uniformly spraying coolant to cover multiple surfaces of all battery cells, uniform cooling is achieved, further maintaining battery performance, thereby being superior to traditional cooling methods such as air cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These aspects are illustrated by way of example and are not limited to the figures in the accompanying drawings, in which like reference numerals represent similar elements. It should be noted that references to "one" or "an" aspect of the present disclosure are not necessarily to the same aspect, and they mean at least one. In addition, for simplicity and to reduce the total number of drawings, a given drawing may be used to illustrate features of more than one aspect, and not all elements in the drawings are required for a given aspect.

[0011] Figure 1is a block diagram illustrating an example of a battery thermal management system including a battery module with spray cooling according to one embodiment.

[0012] Figure 2 is a block diagram illustrating another example of a battery thermal management system according to one embodiment, in which a battery module with spray cooling includes a pump.

[0013] Figure 3 is a block diagram showing another example of a battery thermal management system according to another embodiment, in which a battery module with spray cooling includes a pump and a cooling unit.

[0014] Figure 4 is a block diagram showing another example of a battery thermal management system according to one embodiment, in which a cooling unit is above a battery module with spray cooling.

[0015] Figure 5a and 5b is a block diagram showing different views of another example of a battery thermal management system according to one embodiment.

[0016] Figure 6 is a block diagram showing a perspective view of another example of a battery thermal management system according to one embodiment.

[0017] Figure 7 is a block diagram illustrating an example of a battery thermal management system according to one embodiment, in which a battery module with spray cooling does not have a tank for collecting coolant.

[0018] Figure 8 is a block diagram illustrating an example of a coolant injection panel according to one embodiment.

[0019] Fig. 9 An example of an electronics rack including a battery backup unit (BBU) is shown according to one embodiment.

[0020] Fig.10 An example of a BBU rack populated with several battery modules is shown according to one embodiment. DETAILED DESCRIPTION

[0021] Several aspects of the present disclosure will now be explained with reference to the accompanying drawings. Whenever the shape, relative position and other aspects of the parts described in a given aspect are not explicitly defined, the scope disclosed herein is not limited to the parts shown, which are only used for illustrative purposes. In addition, although many details are set forth, it should be understood that some aspects can be practiced without these details. In other examples, well-known circuits, structures and technologies are not shown in detail to avoid confusing the understanding of this specification. In addition, unless the meaning is obviously contrary, all ranges described herein are considered to include the endpoints of each range.

[0022] References in the specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present disclosure. The phrase "in one embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment.

[0023] According to one embodiment, a battery module includes an output connector, a plurality of battery cells coupled to the output connector, and a plurality of nozzles. The battery cells are configured to provide battery energy to a load via the output connector, and are configured to draw power from an external power source to charge the battery cells via the output connector. The nozzles are configured to spray a coolant on the battery cells to transfer heat generated by the battery cells to the sprayed coolant.

[0024] In one embodiment, the battery module includes a supply line coupled to each of the nozzles and to the cooling unit, wherein the supply line is configured to supply coolant from the cooling unit to the nozzle. In another embodiment, the battery module includes a pool located below the battery cell and configured to collect the coolant ejected by the nozzle. In some embodiments, the battery module includes a pump coupled between the supply line coupled to the nozzle and the cooling unit, and configured to draw coolant from the cooling unit and push the coolant through the supply line and out of the nozzle. When the pump draws and pushes the coolant, the cooling unit is configured to draw the coolant collected in the pool via a return line, thereby creating a heat transfer loop. In some embodiments, the battery cells, nozzles, supply lines, pumps, and cooling units are sealed in the battery module.

[0025] In another embodiment, the nozzle is located above the battery cell. In one embodiment, the nozzle is positioned along at least one side of the battery cell. In some embodiments, the nozzle is configured to spray coolant when the battery cell 1) provides battery energy to a load or 2) draws power from a power source. In another embodiment, the battery cell is at least partially immersed in the coolant collected at the bottom of the battery module.

[0026] In one embodiment, a battery module includes a coolant injection panel including a pressurized chamber configured to maintain a coolant at a higher pressure than outside of the chamber, wherein each of the nozzles is coupled to the coolant injection panel and each is configured to spray the pressurized coolant onto the battery cells.

[0027] According to another embodiment, a battery backup unit (BBU) configured to provide backup power includes a set of one or more battery modules, each of which can be similar to the battery modules described above. In one embodiment, the battery module (and / or BBU) also includes a pump and a cooling unit that create a heat transfer loop with the battery module. In another embodiment, the cooling unit is located on a side of the battery module or above the battery module. In some embodiments, the battery module is removably coupled to at least one of the pump and the cooling unit.

[0028] According to one embodiment, an electronics rack includes a plurality of server blades and other IT equipment arranged in a stack, each server blade including one or more servers providing data processing services, a power supply coupled to the server blade to provide power to operate the server, and a BBU coupled to the server blade to provide backup power to the server when the power supply fails to provide power. The BBU includes at least one battery module, each battery module being similar to the battery modules described above.

[0029] In one embodiment, a cooling system or battery thermal management system for a battery module can address the specific needs of backup power provided by a BBU to support IT racks in a data center or IT room environment. As described above, the conditions and requirements of a BBU in an IT rack, data center, and / or IT room environment are different from the conditions and requirements of a battery module in an electric vehicle application. For example, the thermal environment is different, and far fewer discharge and charge cycles occur in a data center application scenario than in an electric vehicle application.

[0030] Cooling systems for batteries can be critical because nominal battery performance is typically specified for an operating temperature range (e.g., 25°C to 35°C) for the battery cells. Temperature also plays an important role in battery aging. Temperatures outside the operating range can result in reduced performance and negatively impact battery health. In addition, when multiple battery cells are connected, there can be large internal differences between different cell temperatures due to multiple factors such as cell arrangement and variations in cooling conditions, which can result in different charge and discharge rates for each cell and cause performance degradation of the battery module. If the battery temperature exceeds the thermal limit, this can result in extreme damage or injury, or even catastrophic results. Therefore, thermal management of the battery system is an important feature to consider in the design and operation of the battery because it affects how the battery operates, the health and life of the battery, and safety.

[0031] A battery thermal management system for a BBU that can be self-activated by utilizing spray cooling. In one embodiment, the thermal management system includes a battery module, the battery module including 1) an output connector, 2) a plurality of battery cells coupled to the output connector, and 3) a plurality of nozzles. To utilize spray cooling, the system causes the nozzles to spray coolant on the battery cells to transfer (or exchange) heat generated by the battery cells into the sprayed coolant while the battery cells provide battery energy to a load via the output connector or draw power from an external power source to charge the battery cells via the output connector.

[0032] This system using spray cooling provides several advantages over conventional cooling methods such as air cooling. For example, air cooling (e.g., using an external fan that blows cool air to dissipate the generated heat) can cool the cells unevenly when the surfaces of the battery cells are not in direct contact with the airflow generated by the fan. On the other hand, spray cooling can enable uniform cooling because the coolant can be evenly sprayed to cover multiple surfaces of the battery cells, where the coolant is sprayed on the battery cells at similar (or the same) temperatures.

[0033] It should be mentioned that the phrase "battery pack" can be used interchangeably with "battery backup unit module (BBU module)" and "BBU group" herein. Moreover, a BBU may include one or more battery modules (or battery packs). A battery module may include several battery cells. Other features are also described in the following embodiments.

[0034] Figure 1 is a block diagram illustrating an example of a battery thermal management system including a battery module with jet cooling according to one embodiment. Specifically, the figure shows a battery thermal management system 10 (or system) having a battery module 2, a (e.g., mechanical) pump 3, a cooling unit 4, a controller 75, and one or more fans 5. In one embodiment, the system 10 may include more or less of the elements described herein. For example, the system may include two or more battery modules, each of which is coupled to a cooling unit 4 or a separate cooling unit.

[0035] The battery module 2 has a cell chamber 13 and a pool 9 including a coolant 1. The chamber includes a number of battery cells 15, which are positioned (or located) on a rack 14 that separates the cell chamber from the pool. The chamber also includes a number of nozzles 7, each of which is coupled to a supply line 6. In one embodiment, the module can have any shape and configuration. For example, as shown in the figure, the battery module is a rectangular box. However, in other embodiments, the module can be a square box or a cylinder. In some embodiments, the battery module may include one battery cell, or may include two or more battery cells connected in series, in parallel, or a combination thereof. The battery cell 15 may be of any type, such as lithium ion, nickel cadmium, etc. The battery module also includes an output connector 12 (one anode and one cathode), which is coupled to the battery cell and is configured to be coupled to a load (for example, the load may be at least one server) so as to enable the battery module to provide battery energy stored in the battery cell to the load via the output connector, and is configured to be coupled to an external power source (or source) so as to enable the battery module to draw power from the power source to charge the battery cell via the connector. In one embodiment, the output connector 12 is configured to be removably coupled to a load (eg, a connector of the load) to allow battery modules to be removed and / or added (in series or in parallel) to the load.

[0036] As described herein, the supply line 6 is configured to supply a coolant (which may be any type of liquid (or fluid), such as a dielectric fluid) to one or more nozzles 7, which are configured to spray the coolant 8 on one or more battery cells 15 to exchange heat generated by the cells when the battery cells are operating (e.g., when the battery cells are discharging and / or charging). Specifically, the supply line is coupled to the cooling unit 4 and is configured to supply coolant drawn by (or drawn from) the cooling unit. In one embodiment, each of the nozzles 7 can spray coolant in a manner similar to each other (e.g., as shown by each nozzle having three dashed line arrows) so as to uniformly spray the coolant on at least some (or all) of the battery cells. In another embodiment, at least some of the nozzles can spray coolant differently than other nozzles. For example, at least some of the nozzles can spray coolant in a particular direction and / or at least some of the nozzles can spray coolant in an omnidirectional manner.

[0037] The pool 9 is located below the battery cell 15 and is configured to store (hold or collect) the coolant 1. In addition, the pool 9 is configured to collect the sprayed coolant 8, which may be the same as the coolant 1 sprayed by the one or more nozzles 7. In order to collect the sprayed coolant 8, the rack 14 on which the battery cell 15 is located is configured to allow the coolant to flow from the cell chamber 13 to the pool 9, for example, the rack may include one or more holes or openings that allow the coolant to pass through.

[0038] As shown, the pump 3 and the return line 11 are coupled to the battery module 2. Specifically, the pump is coupled between the supply line 6 coupled to the nozzle 7 and the cooling unit 4, and the return line 11 couples the battery module 2 to the cooling unit 4. In one embodiment, the supply line 6 and the return line 11 can be hoses or pipes made of any material. For example, the pipeline can be made of metal (such as copper), polymer (such as EPDM rubber) and / or plastic. In one embodiment, the pipeline can be made of a flexible material (such as rubber). In some embodiments, one pipeline (e.g., a supply line) can be made of a different material from another pipeline (e.g., a return line).

[0039] In one embodiment, the pump 3 is configured to draw coolant from the cooling unit and push the coolant through the supply line and out of the nozzle. In one embodiment, the pump 3 can be coupled to the cooling unit via a separate supply line, or the pump can be directly coupled to the cooling unit. In some embodiments, the pump can be coupled between the return line 11 and the cooling unit 4 and is configured to push the coolant drawn from the pool 9 through the cooling unit. In another embodiment, the pump 3 can be configured to be removably coupled to the supply line and / or the cooling unit to allow the user to remove / replace the pump as needed. In some embodiments, the pump can be any type of mechanical pump. In one embodiment, the pump can be controlled to push the coolant (e.g., controlled by the controller 75) at a specific flow rate. More content about controlling the pump is described herein.

[0040] The cooling unit 4 may be any type of cooling unit configured to extract heat energy from a coolant or cooling fluid. As shown, the unit 4 is an air-to-liquid heat exchanger coupled to the pump 3 and coupled to the battery module 2 (e.g., via the return line 11), and has one or more fans 5 for dissipating heat. In one embodiment, the unit 4 may be a liquid-to-liquid heat exchanger. In one embodiment, the system 10 may not include a cooling unit for the battery module, but may be coupled to a separate, external cooling unit or cooling loop.

[0041] The controller 75 can be a dedicated processor, such as an application-specific integrated circuit (ASIC), a general-purpose microprocessor, a field-programmable gate array (FPGA), a digital signal controller, or a set of hardware logic structures (e.g., filters, arithmetic logic units, and dedicated state machines). In one embodiment, the controller can be a circuit having a combination of analog elements (e.g., resistors, capacitors, inductors, etc.) and / or digital elements (e.g., logic-based elements, such as transistors, etc.). The controller can also include a memory. In one embodiment, the controller 75 can be part of the battery module 2 (e.g., included within the module or coupled to the outside of the module), or can be communicatively coupled to the battery module (e.g., can be part of the circuit of the BBU group or part of the electronic rack that holds the BBU group).

[0042] In one embodiment, the controller 75 is configured to control the pump 3 (e.g., by sending a control signal 76 to a control circuit of the pump, such as an electronic switch) in order to activate a heat transfer (or heat exchange) circuit. Specifically, the controller 75 may monitor certain criteria to determine whether coolant should be sprayed onto the battery cells. For example, the controller 75 may determine whether current is flowing from (or into) the battery cells (based on current sensing), which may indicate that the cells are in operation (e.g., discharging and / or charging). As another example, the controller 75 may be communicatively coupled to a temperature sensor (not shown) positioned within the cell chamber 13 (or on the battery module). The controller 75 may obtain an electrical signal representing a temperature reading from the sensor. If the reading is above a threshold, the controller 75 may activate the pump to cool the battery. Once the cell reaches (or falls below) the threshold (and / or the battery is no longer discharging / charging), the controller 75 may not activate the pump. In another embodiment, the controller 75 may adjust the flow rate of the coolant within the heat exchange circuit by adjusting the rate at which the pump pushes the coolant. The controller 75 may adjust the rate based on the criteria mentioned herein. For example, the flow rate may be based on a temperature reading (eg, a higher reading results in a higher flow rate).

[0043] Thus, during operation, the battery thermal management system 10 creates a heat exchange loop that discharges thermal energy absorbed by the injected coolant 8 in order to manage the operating temperature of the unit. For example, when the battery cells 15 are discharged / charged, the pump 3 is configured to be activated (e.g., by the controller 75) and push the coolant into the supply line 6 and out of the nozzle 7. The injected coolant 8 contacts the battery cells 15 that generate heat and extracts thermal energy from the battery cells, thereby cooling the cells. The coolant 8 then traverses the rack 14 and is collected in the pool 9. As the pump pushes the coolant, the cooling unit 4 is configured to draw the coolant collected in the pool via the return line 11 and extract thermal energy from the coolant. Thus, the coolant circulating through the system 10 absorbs thermal energy from the battery cells 15, and this energy is discharged by the cooling unit 4.

[0044] Figure 2 is a block diagram showing another example of a battery thermal management system according to one embodiment, in which a battery module with jet cooling includes a pump. As shown, the system 20 includes a battery module 22, which is similar to module 2, but differs in that a pump 3 is coupled to a supply line 6 within the battery module (e.g., a cell chamber of the battery module). In this example, the battery module also includes a supply connector 23 coupled to the pump (e.g., directly coupled or via a separate line) and removably coupled to a cooling unit 4, and a return connector 24 removably coupled to the cooling unit 4. In one embodiment, the two connectors can be directly removably coupled to the cooling unit 4, or can be coupled to the cooling unit 4 via corresponding separate supply lines and return lines. In one embodiment, the connector can be a drip-free blind-mate quick disconnect device. The two connectors enable the battery module to 1) be disconnected from the cooling unit (e.g., coupled to a separate supply and / or return line of the cooling unit) to remove the battery module from the heat exchange loop, and 2) be connected to the cooling unit to create a heat exchange loop. In one embodiment, the connector can be any type of connector, such as a quick-connect fitting that allows easy connection / removal of the battery module.

[0045] Figure 3 is a block diagram showing another example of a battery thermal management system according to one embodiment, in which a battery pack with jet cooling includes a pump and a cooling unit. As shown, the system 30 includes a battery module 32 having a heat exchange circuit contained inside the battery module. Specifically, the pump, the supply line / return line and the cooling unit are inside the chamber. In order to exchange heat, the cooling unit 4 (which is a liquid-liquid heat exchanger) is coupled to a supply path 31 configured to supply cooling fluid to the cooling unit 4 and a return path 34 configured to receive cooling fluid from the cooling unit 4. In one embodiment, the supply path 31 and the return path 34 can be coupled to an external cooling source, such as a data center cooling water system or an IT liquid cooling water system (not shown). In one embodiment, the heat exchange circuit between the cooling unit 4 and the external cooling source can be referred to as a primary circuit, and the heat exchange circuit between the cooling unit 4 and the battery module (e.g., the coolant collected in the pool of the battery module) can be referred to as a secondary circuit. Therefore, during operation, the heat absorbed by the secondary circuit (e.g., the coolant in the secondary circuit) will be transferred to the cooling fluid circulating through the primary circuit. In one embodiment, the supply path 31 and the return path 34 can be hoses or pipes made of similar materials as the supply lines described herein. In another embodiment, the supply path 31 and / or the return path 34 can be coupled to a distribution manifold configured to circulate the cooling fluid through one or more battery packs (or cooling units).

[0046] In one embodiment, because the battery module includes supply and return connectors (which can be removably coupled to the supply path 31 and the return path 34), the module can be a self-contained unit. Specifically, the module can include a container 33, in which components of the battery thermal management system (e.g., a pump and a cooling unit) are sealed within the container along with the nozzles, supply lines / return lines, and / or battery cells. Sealing the battery module ensures that any coolant remains contained therein, thereby preventing or reducing the possibility of any potential leakage. In one embodiment, any of the battery modules shown in any of the battery thermal management systems herein can be sealed, wherein only coolant (or cooling fluid) is allowed to enter / leave the battery module (e.g., via a supply connector and a return connector).

[0047] Figure 4 is a block diagram showing another example of a battery thermal management system according to one embodiment, wherein a cooling unit is above a battery module with jet cooling. Specifically, as described so far, the cooling unit 4 can be located in close proximity to the battery module (or on one side of the battery module). In some embodiments, the cooling unit 4 can be located above the battery module 42, as shown in this example. In this example, the cooling unit of the system 40 is above the battery module and is coupled to a supply line and a return line (e.g., via a connector as described herein), both of which are within the module. Here, one end of the return line is immersed in the coolant 1 collected in the pool, and the other end is coupled to the cooling unit. In order to circulate the coolant 1 throughout the heat exchange loop, a pump is coupled to the return line (e.g., between the return line and the cooling unit) so as to draw the coolant from the pool and pass it through the cooling unit. In one aspect, the cooling unit can be removably coupled to the top of the battery module via a connection or latch.

[0048] Figure 5a and 5b Block diagram showing different views of another example of a battery thermal management system according to one embodiment. As described so far, the battery cells of a battery module can be spray cooled using nozzles located above the battery cells. In one embodiment, the nozzles can be located at different locations within the battery cell chamber. For example, as shown in these examples, the battery module 52 includes nozzles located along at least one side of the battery cells. Specifically, Figure 5a A perspective view of a system 50 for spray cooling a battery cell side is shown, and Figure 5b A top view of system 50 is shown.

[0049] These figures show that there are two supply lines, a right supply line 41 and a left supply line 44. The right supply line is coupled to a set (e.g., a first set) of nozzles, wherein the right supply line 41 is configured to supply coolant to the first set of nozzles so that these nozzles spray coolant toward the right side of the battery cell. The left supply line is coupled to a set (e.g., a second set) of nozzles, wherein the left supply line is configured to supply coolant to the second set of nozzles so that these nozzles spray coolant toward the left side of the battery cell. Also as shown, a pump is coupled to a return line to draw coolant from the pool into the cooling unit, rather than having a pump for each supply line. In one embodiment, each supply line can be coupled to its own pump. In another embodiment, the system can include only one supply line (e.g., only the right supply line 41) or two or more supply lines.

[0050] Also shown are battery cells in groups of three, with each group being separate (e.g., not abutting or contacting) another group (and / or a side or wall of the battery module). Figure 1 In contrast to a battery cell, for example, the battery cell is grouped in eleven cells. By separating the separate groups of cells, the sprayed coolant can cover more surface area, resulting in more uniform and consistent heat exchange. In one embodiment, the battery module may include one or more groups of cells separated from each other, wherein each group includes one or more cells. In another embodiment, each group of cells may be connected in any manner (e.g., in series and / or in parallel).

[0051] Figure 6 is a block diagram showing a perspective view of another example of a battery thermal management system according to one embodiment. Specifically, the figure shows a battery thermal management system 60 that includes a cooling unit located above a battery module 62, wherein the module includes two supply lines, each supply line spraying coolant on a different side of the battery cells within the module.

[0052] Figure 7 is a block diagram illustrating an example of a battery thermal management system according to one embodiment, wherein a battery pack with jet cooling does not have a pool for collecting coolant. Specifically, in this example, the system 70 includes a battery module 72 that does not include a rack 14 on which battery cells are positioned. Because the battery module does not include a rack, the battery cells are positioned at the bottom of the battery cell chamber. Therefore, the battery cells are at least partially immersed in the coolant collected at the bottom of the battery module (of the battery cell chamber). In one embodiment, the partially immersed battery cells can enable a better thermal environment for the cells.

[0053] Figure 8is a block diagram showing an example of a coolant injection panel according to one embodiment. Specifically, the figure shows a coolant injection panel 80, which includes a pressurized coolant chamber 81, which is configured to maintain the coolant 1 at a higher pressure than the outside of the chamber. The panel 80 is coupled to a supply line 6, which supplies coolant from an external cooling unit (e.g., cooling unit 4). The panel 80 also includes a nozzle 7, which is configured to spray the pressurized coolant maintained in the chamber onto one or more battery cells. In one embodiment, the panel 80 can be positioned above the cell chamber 13 of the battery module so as to spray the pressurized coolant above the battery cell, or can be positioned on one side of the cell chamber 13 so as to spray the coolant toward the cell side. In some embodiments, the battery module may include two or more panels 80 that can be arranged side by side with each other. A bottom view of the chamber 81 is also shown, which includes a nozzle opening 82 for each of the nozzles 7.

[0054] In one embodiment, chamber 81 can pressurize the coolant by any method that can be used to pressurize the chamber. For example, chamber 81 may include a bladder or diaphragm filled with air separated from the coolant 1. The bladder pushes the coolant, and when the nozzle is activated, the coolant is caused to spray out of the nozzle at a high flow rate. In one aspect, the system can maintain the pressure in the chamber above a pressure threshold (or within a pressure range). The system may include a pressure sensor configured to detect pressure in the chamber. When the pressure is below the pressure threshold, a pump (e.g., pump 3) coupled to supply line 6 can be configured to activate, causing the coolant to enter the chamber. The coolant added to the chamber will push the bladder, resulting in an increase in pressure. This process can be performed when the battery cells of the battery pack are in operation.

[0055] As described above, a BBU group can be used as a backup power supply unit in an electronic rack of a data center. The electronic rack includes an array of server blades, each of which includes a computer server for data processing. The electronic rack also includes a power supply that provides power to the server blades and a BBU group that provides backup power to the server blades or other IT equipment when the power supply is unavailable. The BBU group can include components (e.g., a controller) that can perform cooling control operations to ensure that the battery cells of the BBU group do not overheat.

[0056] Fig. 9900 is a block diagram showing an example of an electronic rack according to one embodiment. The electronic rack 900 may include one or more server slots to accommodate one or more servers, respectively. Each server includes one or more information technology (IT) components (e.g., processors, memories, storage devices, network interfaces). According to one embodiment, the electronic rack 900 includes, but is not limited to, a CDU 901, a rack management unit (RMU) 902 (optional), a power supply unit (PSU) 950, a BBU 90 (which may include a battery thermal management system having any of the components described herein, such as a battery module, a controller, a pump, and / or a cooling unit) and one or more server blades 903A-903D (collectively referred to as server blades 903). The server blades 903 may be inserted into the array of server slots from the front end 904 or the rear end 905 of the electronic rack 900, respectively. The PSU 950 and / or the BBU 90 may be inserted into any of the server slots 903 within the electronic rack 900. In one embodiment, one or more BBUs may be inserted into any of the server slots 903 within the electronic rack 900.

[0057] Note that although only four server blades 903A-903D are shown here, more or fewer server blades may be maintained within the electronics rack 900. It should also be noted that the specific locations of the CDU 901, RMU 902, PSU 950, BBU 90, and server blades 903 are shown for illustration purposes only; other arrangements or configurations of the CDU 901, RMU 902, BBU 90, and server blades 903 may also be implemented. Note that the electronics rack 900 may be open to the environment or partially contained by a rack container, as long as the cooling fans can generate airflow from the front to the rear.

[0058] In addition, a fan module may be associated with each of the server blades 903 and the BBU 90. In this embodiment, fan modules 931A-931E, collectively referred to as fan modules 931, are associated with server blades 903A-903D and the BBS 1, respectively. Each of the fan modules 931 includes one or more cooling fans. The fan modules 931 may be mounted on the rear end of the server blades 903 and the BBU 90 to generate an airflow that flows from the front end 904, flows through the air interlayer of the server blades 903, and exits at the rear end 905 of the electronics rack 900. In one embodiment, each of the fan modules may be mounted on the rear end of the server blades 903 and one or more BBUs.

[0059] In one embodiment, the CDU 901 mainly includes a heat exchanger 911, a liquid pump 912 and a pump controller (not shown) and some other components, such as a liquid reservoir, a power supply, a monitoring sensor, etc. The heat exchanger 911 can be a liquid-liquid heat exchanger. The heat exchanger 911 includes a first loop with an inlet and an outlet, and the first loop has a first pair of liquid connectors coupled to an external liquid supply / return line 931-932 to form a main loop. The connector coupled to the external liquid supply / return line 931-932 can be arranged or installed on the rear end 905 of the electronic rack 900. The liquid supply / return line 931-932 is coupled to a set of room manifolds, and the room manifold is coupled to an external heat removal system or an external cooling loop. In addition, the heat exchanger 911 also includes a second loop with two ports, and the second loop has a second pair of liquid connectors coupled to the liquid manifold 925 to form a secondary loop, which can include a supply manifold that supplies cooling liquid to the server blade 903 and a return manifold that returns warmer liquid to the CDU 901. Note that CDU 901 can be any kind of commercially available CDU or customized CDU. Therefore, the details of CDU 901 will not be described here. As an example, BBU 90 can be connected to 925 to complete the complete fluid loop.

[0060] Each of the server blades 903 may include one or more IT components (e.g., a central processing unit or CPU, a graphics processing unit (GPU), memory, and / or storage device). Each IT component may perform data processing tasks, wherein the IT component may include software installed in a storage device, loaded into the memory, and executed by one or more processors to perform data processing tasks. At least some of these IT components may be attached to the bottom of any cooling device as described above. The server blade 903 may include a host server (referred to as a host node) coupled to one or more computing servers (also referred to as computing nodes, such as CPU servers and GPU servers). The host server (with one or more CPUs) typically interfaces with a client over a network (e.g., the Internet) to receive requests for specific services, such as storage services (e.g., cloud-based storage services such as backup and / or recovery), executing applications to perform certain operations (e.g., image processing, deep data learning algorithms or modeling, etc. as part of a software as a service or SaaS platform). In response to the request, the host server assigns the task to one or more performance computing nodes or computing servers (with one or more GPUs) managed by the host server. The performance computing server performs the actual task, which may generate heat during operation.

[0061] The electronic rack 900 also includes an optional RMU 902, which is configured to provide and manage power provided to the server 903, the fan module 931, and the CDU 901. The optimization module 921 and the RMC 922 can communicate with the controller of some of the applications. The RMU 902 can be coupled to the PSU 950 to manage the power consumption of the PUS. The PSU 950 can include necessary circuits (e.g., alternating current (AC) to direct current (DC) or DC to DC power converters, backup batteries, transformers or regulators, etc.) to provide power to the remaining components of the electronic rack 900.

[0062] In one embodiment, the RMU 902 includes an optimization module 921 and a rack management controller (RMC) 922. The RMC 922 may include a monitor to monitor the operating status of various components within the electronic rack 900, such as, for example, the computing node 903, the CDU 901, and the fan module 931. Specifically, the monitor receives operating data from various sensors representing the operating environment of the electronic rack 900. For example, the monitor may receive operating data representing the temperature of the processor, the coolant, and the airflow, and the operating data may be captured and collected via various temperature sensors. The monitor may also receive data representing the fan power and pump power generated by the fan module 931 and the liquid pump 912, and the power may be proportional to their respective speeds. These operating data are referred to as real-time operating data. Note that the monitor may be implemented as a separate module within the RMU 902.

[0063] Based on the operational data, the optimization module 921 performs optimization using a predetermined optimization function or optimization model to derive a set of optimal fan speeds for the fan module 931 and an optimal pump speed for the liquid pump 912, so that the total power consumption of the liquid pump 912 and the fan module 931 is minimized, while the operational data associated with the liquid pump 912 and the cooling fan of the fan module 931 are within their respective design specifications. Once the optimal pump speed and the optimal fan speed are determined, the RMC 922 configures the liquid pump 912 and the cooling fan of the fan module 931 based on the optimal pump speed and the fan speed.

[0064] As an example, based on the optimal pump speed, the RMC 922 communicates with the pump controller of the CDU 901 to control the speed of the liquid pump 912, which in turn controls the liquid flow rate of the cooling liquid of the liquid manifold 925, which will be distributed to at least some of the server blades 903. As a result, the operating conditions and corresponding cooling device performance are adjusted. Similarly, based on the optimal fan speed, the RMC 922 communicates with each of the fan modules 931 to control the speed of each cooling fan of the fan module 931, which in turn controls the airflow rate of the fan module 931. Note that each of the fan modules 931 can be individually controlled using its specific optimal fan speed, and different fan modules and / or different cooling fans in the same fan module can have different optimal fan speeds.

[0065] Note that some or all of the IT components of server 903 (e.g., 903A, 903B, 903C, and / or 903D) can be attached to any of the above-mentioned cooling devices via air cooling using a radiator or via liquid cooling using a cooling plate. One server can utilize air cooling while another server can utilize liquid cooling. Alternatively, one IT component of a server can utilize air cooling while another IT component of the same server can utilize liquid cooling. In addition, a switch is not shown here, which can be air-cooled or liquid-cooled. In one embodiment, the location of the equipment or components of the electronic rack (such as PSUs and BBUs) can be varied and may not be exactly as shown in the figure.

[0066] In the foregoing description, embodiments of the present disclosure have been described with reference to specific exemplary embodiments of the present disclosure. However, it is apparent that various modifications may be made thereto without departing from the broader spirit and scope of the present disclosure as set forth in the appended claims. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

[0067] Fig.10 1 is an example of a BBU rack populated with several battery modules according to one embodiment. The figure shows a BBU rack 100 that includes four battery modules 104, a coolant distribution manifold 101, and a controller 76. Each of the battery modules is a sealed system that includes battery cells, two sets of nozzles coupled to separate supply lines, a pump, and a cooling unit. In one embodiment, each of the battery modules can be the same or different from each other. For example, one battery module can be a sealed system with nozzles above the cells (such as Figure 3 ), and the other battery pack can be the same as that shown in the figure.

[0068] In one embodiment, the distribution manifold 101 is coupled to the heat exchanger 911 via the manifold 925 to create a heat exchange loop (e.g., a main loop as described herein). Specifically, the supply line of each of the groups is coupled to the supply path 102 of the manifold 101, and the return line of each of the groups is coupled to the return path 103 of the manifold 101 so that the module becomes part of the main heat exchange loop. Each of the paths can be coupled to a corresponding path (or line) of the manifold 925 to allow coolant from the heat exchanger 911 to circulate through each of the battery modules. In one embodiment, the distribution manifold 101 may be coupled to one or more heat exchangers. In some embodiments, instead of (or in addition to) having a coolant distribution manifold 101, the battery modules of the BBU can be (e.g., directly) connected (or removably coupled) to the liquid manifold 925 of the electronic rack.

[0069] The controller 76 is configured to activate at least some of the heat exchange circuits in the battery modules (e.g., by controlling pumps integrated therein). Specifically, the controller 76 may perform similar operations as described herein with respect to the controller 75. However, in one embodiment, each of the controllers of the battery modules may control the circuits as described herein.

[0070] In another embodiment, one of the battery modules within the BBU 100 may include fewer components as described herein. For example, the battery module may not include a cooling unit. Instead, a pump within the battery module may draw coolant from the main circuit to cause the nozzle to spray the coolant of the main circuit to cool the corresponding battery cell. In some embodiments, the pump may not be sealed in the battery module but may be part of the BBU.

[0071] In one embodiment, although each battery thermal management system shown herein is described separately, any one of the systems (or components within a system or module) can be used in conjunction (or combination) with any one of the other systems or modules described herein to create a heat exchange loop.

[0072] In the foregoing description, embodiments of the present disclosure have been described with reference to specific exemplary embodiments of the present disclosure. However, it is apparent that various modifications may be made thereto without departing from the broader spirit and scope of the present disclosure as set forth in the appended claims. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

[0073] As previously described, embodiments of the present disclosure may be (or include) a non-transitory machine-readable medium (such as a microelectronic memory) having stored thereon instructions that program one or more data processing components (collectively referred to herein as "processors") to perform battery thermal management operations, such as controlling a pump to spray coolant on a battery cell as the cell is discharged / charged. In other embodiments, some of these operations may be performed by specific hardware components including hardwired logic. These operations may alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components.

[0074] Although certain aspects have been described and shown in the accompanying drawings, it should be understood that these aspects are merely illustrative of the broad disclosure and not limiting, and the disclosure is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to one of ordinary skill in the art. Therefore, this description should be regarded as illustrative and not restrictive.

[0075] In some aspects, the disclosure may include language, such as, “at least one of [element A] and [element B]”. Such language may refer to one or more of the elements. For example, “at least one of A and B” may refer to “A”, “B”, or “A and B”. Specifically, “at least one of A and B” may refer to “at least one of A and at least one of B” or “at least one of A or B”. In some aspects, the disclosure may include language, such as, “[element A], [element B], and / or [element C]”, which may refer to any one of the elements or any combination thereof. For example, “A, B, and / or C” may refer to “A”, “B”, “C”, “A and B”, “A and C”, “B and C”, or “A, B, and C”.

Claims

1. A battery module, comprising: Output connector; a plurality of battery cells coupled to the output connector, wherein the battery cells are configured to provide battery energy to a load via the output connector and are configured to draw power from an external power source to charge the battery cells via the output connector; a plurality of nozzles configured to spray a coolant onto the plurality of battery cells to transfer heat generated by the battery cells to the sprayed coolant; a supply line coupled to each of the plurality of nozzles and connected to a cooling unit; a tank located below the plurality of battery cells and configured to collect the coolant sprayed by the nozzle; a rack on which the plurality of battery cells are respectively vertically positioned, the rack being configured to be separated from the pool and to allow the coolant to traverse the rack and flow into the pool; a pump coupled between the supply line and the cooling unit and configured to push the coolant out of the plurality of nozzles; and wherein the plurality of battery cells, the plurality of nozzles, the supply line, the pump, and the cooling unit are sealed in the battery module; a coolant injection panel comprising a pressurized coolant chamber configured to maintain coolant at a higher pressure than an exterior of the chamber; wherein each of the plurality of nozzles is coupled to the coolant injection panel and each is configured to spray the pressurized coolant onto the plurality of battery cells; wherein the coolant chamber includes a bladder filled with air separated from the coolant, the bladder pushing the coolant, causing the coolant to be ejected from the nozzle when the nozzle is activated; A controller determines whether to activate the pump by sensing current in the battery cells. 2 . The battery module of claim 1 , wherein the supply line is configured to supply coolant from the cooling unit to the nozzle. 3 . The battery module of claim 2 , wherein the pump is configured to draw coolant from the cooling unit and push the coolant through the supply line and out of the nozzle.

4. The battery module according to claim 3, wherein: When the pump pushes the coolant, the cooling unit is configured to draw the coolant collected in the pool via a return line, thereby forming a heat transfer loop. The battery module of claim 1 , wherein the plurality of nozzles are located above the plurality of battery cells. 6 . The battery module of claim 1 , wherein the plurality of nozzles are positioned along at least one side of the plurality of battery cells. 7 . The battery module of claim 1 , wherein the plurality of nozzles are configured to spray coolant when the plurality of battery cells 1) provide battery energy to the load or 2) draw power from the power source. 8 . The battery module of claim 1 , wherein the plurality of battery cells are at least partially submerged in a coolant collected at a bottom of the battery module.

9. A battery backup unit (BBU), comprising a group of one or more battery modules according to any one of claims 1-8.

10. An electronic rack comprising: a plurality of server blades arranged in a stack, each server blade comprising one or more servers providing data processing services; a power supply coupled to the server blade to provide power to operate the server; as well as A battery backup unit (BBU), the battery backup unit (BBU) coupled to the blade server to provide backup power to the blade server when the power supply fails to provide power, wherein the battery backup unit (BBU) includes at least one battery module according to any one of claims 1-8.

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