ENERGY STORAGE TANK WITH VORTEX SEPARATOR

Abstract

Energy storage containers (100) with: a plurality of containers (104) each containing electrochemical cells, the containers (104) being arranged in a vertical stack inside the energy storage container (100); a deduction (112); a plurality of outlets (110) from the containers (104) into the flue (112); a collecting basin (202, 304) and a vortex separator (204, 300) connected to the collection basin and having an inlet opening (204A, 400, 500) towards the exhaust (112), a first outlet opening (204B, 306) towards the collection basin (202, 304) and a second outlet opening (308) towards an outside of the energy storage container (100), wherein the first outlet opening (204B, 306) is adapted to allow particles to fall out at the outlet opening and into the collection basin (202, 304), while the second outlet opening is adapted to discharge upwardly directed gas to the outside.

Description

Background of the invention

[0001] Efforts are underway in many areas to transition the world's energy consumption from fossil fuels to renewable energy sources. Because today's electricity grid is partly powered by non-renewable energy sources, transition efforts have focused in part on supporting the generation and storage of energy on-site rather than in remote power plants. This may include solar energy (i.e., photovoltaic panels that convert sunlight into electricity) or wind energy (wind turbines in a wind farm). Because the power output of these types of energy sources fluctuates throughout the day, and because energy demand also fluctuates, the ability to store electrical energy for later use becomes increasingly important.

[0002] One of the key technologies for storing electrical energy is electrochemical cells (e.g., lithium-ion cells). Their advantages are well-known: they have high energy density, can deliver large amounts of energy on demand, and can be reused multiple times. Like most types of energy storage, electrochemical cells must be properly operated to achieve optimal performance and avoid failure. Such operation includes controlling the charging and discharging processes and managing the temperature of the cells. In extreme situations, a malfunctioning cell can undergo a process called thermal runaway, in which the cell generates too much heat. Eventually, the thermally unstable cell may gradually emit smoke and electrolyte vapors from its casing. This can affect neighboring cells and other equipment.

[0003] For the state of the art, reference is made to US 5 203 891 A and DE 10 2013 204 585 A1.

[0004] US 5,203,891 A describes a gas / liquid separator comprising a hollow, cylindrical separator body having an inlet opening for receiving a tangential inflow of a gas / liquid mixture and an outlet opening through which liquid separated from the mixture can exit tangentially from the cylindrical separator body. The inlet port and the outlet port are arranged so that they are 90 degrees apart. A hollow cylindrical vortex finder is arranged concentrically within the cylindrical separator body, allowing the predetermined exit of the primary and secondary gas streams.

[0005] DE 10 2013 204 585 A1 discloses a battery pack for use in electric vehicles. For a degassing situation in which an individual battery cell releases gas from its interior via an overpressure mechanism, for example due to overcharging or thermal overload, a special free space is provided in a battery pack housing into which the released gas can expand and thereby reduce its temperature and pressure. The gas is then released from the interior of the battery pack housing to the outside via an overpressure release device. The gas flows through a particle separator provided in the overpressure release device, for example in the form of a cyclone separator or a surface filter with a fiber composite or an open-pore sponge-like structure. Particles contained in the gas, such as graphite dust, can be filtered out as it flows through the particle separator, for example toto avoid explosive concentrations within the escaping gas. Brief description of the invention

[0006] The invention provides an energy storage container with a vortex separator according to claim 1. Embodiments of the invention are specified in the dependent claims.

[0007] The energy storage container comprises: a plurality of containers each containing electrochemical cells, the containers being arranged in a vertical stack inside the energy storage container; a flue; a plurality of outlets from the containers into the flue; a sump; and a vortex separator having an inlet opening toward the flue, a first outlet opening toward the sump, and a second outlet opening toward an exterior of the energy storage container.

[0008] Embodiments may include one or all of the following features. The flue is defined by first and second parallel walls, the second wall being an inner one of the parallel first and second walls and having the plurality of outlets therein. The sump is partially defined by at least one partition between the parallel first and second walls. The inlet opening includes an opening through the partition. The energy storage vessel further includes an ash guard partially covering at least a lowermost outlet of the plurality of outlets. The ash guard includes a lower enclosure open at a top thereof and a canopy separated from the top of the lower enclosure by a gap. The gap corresponds to an outlet of the plurality of outlets. The lower enclosure is wider at its bottom than at its top.The bottom is essentially as wide as the flue. The vortex separator is located inside the containment basin. The flue is located at a rear side of the energy storage vessel opposite a door to the plurality of vessels.

[0009] The vortex separator may further comprise: a housing having a cylindrical chamber therein; an inlet opening through a shell of the cylindrical chamber, the inlet opening being located at a proximal end of the housing; a tube opening into the housing at the proximal end and extending axially through the cylindrical chamber to a closed distal end of the housing; an outlet opening through the shell, the outlet opening being located at the distal end; and a catch basin at the outlet opening.

[0010] Embodiments may include one or all of the following features. The vortex separator is configured for installation with the cylindrical chamber in a horizontal orientation. The outlet opening faces downward, and the catch basin is disposed below the housing. The vortex separator further includes a screen at least partially covering an opening of the tube inside the cylindrical chamber. The screen is cylindrical. The screen extends at least from the opening of the tube to the distal end. The tube has a bend outside the housing that provides an outlet opening that is vertically oriented. The catch basin has an upper portion having a substantially square cross-sectional profile and a lower portion having a rectangular cross-sectional profile. The upper portion is wider than the lower portion. Short description of the drawings Fig. 1 shows a partial sectional view of an energy storage container. Fig. 2 shows a top view of the energy storage container of Fig. 1. Fig. 3 shows a perspective view of a vortex separator. Fig. 4 shows a top view of the vortex separator of Fig. 3. Fig. 5 shows another perspective view of the vortex separator of Fig. 3. Fig. 6 shows another perspective view of the vortex separator of Fig. 3. Detailed description

[0011] This document describes examples of systems and methods for managing electrochemical cell systems during failures such as thermal runaway. As discussed above, thermal runaway can result in a large expulsion of gas and other matter from the casing of an individual cell. The matter can be in the form of larger pieces, such as a cell casing cap or a contact plate, and smaller pieces, such as fragments of one of the cell's components. Whether large or small, the fragments or other solid materials that can be ejected during a thermal event are collectively referred to herein as "particles." Due to the significant heat generation, some particles can reach temperatures so high that they glow or become virtual sparks.When sparks come into contact with gas, such as the smoke produced during a thermal runaway, there is a risk of ignition. It would be desirable to isolate the sparks from the gas to minimize the consequences of the thermal event. Therefore, embodiments of the present invention seek to contain particles in a closed vessel, referred to as a containment basin, and allow the gas to escape into the environment.

[0012] Fig. Figure 1 shows a partial cross-sectional view of an energy storage container 100. Essentially, the energy storage container contains groups of electrochemical cells (described in more detail later) and controls their charging and discharging. The present energy storage container is essentially in the form of a cabinet having three side walls (e.g., left, right, and rear walls) disposed between a top and a bottom. Here, the energy storage container has a door 102 hinged to the rest of the structure. The door, which is currently closed, allows service access to the electrochemical cells and other components of the system, such as a battery control system, a cooling system, and a communications component.

[0013] Since the illustration is a cross-sectional view, containers 104 are visible inside the energy storage container. The containers are arranged here in a vertical stack between the top and bottom of the energy storage container. In this example, there are 16 containers in the energy storage container, but other embodiments may have more or fewer containers. Each of the containers contains a number of electrochemical cells (e.g., lithium-ion cells) that are connected to one another and to control components so that they can absorb energy (during charging) and release it again when needed (i.e., during discharging). The container may, for example, have cells that collectively provide a specific DC voltage, as well as a DC-DC converter that converts the cell voltage to a specific (higher) DC voltage.This cumulative voltage from all the containers can then serve as the output current from the energy storage container. For example, the energy storage container can provide direct current to an inverter (not shown) that generates alternating current for use in a residential home or commercial site. The containers, which in some embodiments may have different sizes or proportions, can be made of any material suitable for the cell types and intended use.

[0014] Each of the containers is a substantially closed structure having an outlet opening 106 toward (in this example) its rear side. This means that contacts for power and communication can be made at other locations on the container, and the outlet opening is configured to allow gas and particles to escape during a thermal event. Here, the outlet openings are each fitted into a corresponding opening of an inner wall 108 in the energy storage container. A small portion of each outlet opening (e.g., a cap or other closure) extends to the other side of the inner wall 108, where it forms a respective outlet 110 for that container.

[0015] A vent or chimney 112 is formed between the inner wall 108 and an outer wall 114. In this example, the two walls are parallel to each other and serve to define the vent at the rear of the energy storage vessel. The vent allows gas and particles to exit the vessels through outlet openings 110. An ash guard 116 partially encloses the lowest outlets. The ash guard protects the outlets of the lowest vessels from becoming clogged with particles falling from the outlets of vessels higher up. That is, the ash guard allows the covered vessels to expel their own gases and particles, but reduces the accumulation of particles from vessels above in front of the outlet. In other embodiments, more or fewer vessel outlets may be covered by the ash guard.

[0016] A partition 118 is disposed between the inner wall 108 and the outer wall 114 and is part of the structure that defines the fume hood. As described below, the partition may also define a containment basin. In particular, the partition has an opening 120 through which gas and particles can exit the fume hood and thereby be further removed from the containers. For example, the resulting gas may escape into the environment, while the particles may be trapped in a containment basin to largely separate them from the gas.

[0017] Fig. 2 shows a top view of the energy storage container 100 of Fig. 1. Here is the outer wall 114 ( Fig. 1) has been omitted to show the vent 112, the outlets 110, and the associated structures. In particular, it can be seen that the partition 118 and another partition 200 serve to define a catch basin 202. The catch basin is a substantially enclosed structure that collects particles discharged from one of the containers.

[0018] The energy storage vessel has a vortex separator 204 for separating particles (i.e., potential sparks) from the escaping gas (which may be flammable). Specifically, the vortex separator receives gas and particles flowing in through an inlet port 204A. For example, the inlet port is formed so that a portion of the vortex separator faces an opening in the partition into the flue. Within the vortex separator, the gas and particle flow is directed into a spiral path inside a cylindrical housing. The housing has an outlet port 204B at its bottom and an outlet 204C at its top. The spiral flow causes the particles to fall out of the outlet port 204B and into the collection basin, while the gas is directed upward and exits the outlet 204C.This means that the vortex separator is arranged inside the collecting basin, but in other designs it can also be arranged elsewhere, such as outside the energy storage container or inside the flue.

[0019] The ash guard 116 is disposed toward the bottom of the outlets 110. Here, the ash guard includes a lower enclosure 206 and a canopy 208. The lower enclosure covers one or more of the lowest outlets (here, the bottom six) and is closed on all sides except the top (i.e., it has an opening facing upward). The opening allows gas and particulates to escape from the lower outlets. The canopy also prevents particulates falling from upper outlets from accumulating in front of the lower outlets. Instead, these particulates are directed toward spaces between the lower enclosure and the flue walls.

[0020] The lower enclosure 206 and the canopy 208 are separated by a gap. This gap allows gas and particles inside the lower enclosure to escape (and eventually reach the vortex separator), while the canopy stops falling particles. In this example, the gap corresponds to the size of one of the outlets (here, the seventh from the bottom).

[0021] The lower enclosure 206 may be wider at its bottom than at its top. For example, the relatively wide floor provides sufficient space for particles to accumulate inside the enclosure without covering the outlets, while a relatively narrow opening prevents particles from falling into the enclosure. Here, the floor of the lower enclosure is essentially as wide as the vent, but it may be narrower in some configurations.

[0022] In the above examples, the vortex separator is oriented vertically, which aids in the separation of particles from the gas as the particles fall from the bottom into a collection basin. However, other designs may have different orientations.

[0023] Fig. Figure 3 shows a perspective view of a vortex separator 300 oriented horizontally. The vortex separator has a housing 302, which is generally cylindrical in shape, and a collection basin 304 disposed beneath the housing. They are connected by an outlet port 306 through which the particles can exit the housing, as described later. The vortex separator also has an outlet port 308 for gas to escape. The vortex separator can be mounted, for example, on an electrochemical cell enclosure oriented vertically so that its discharge direction is upward. Gas and particles generated during a thermal event enter the vortex separator through an inlet port (not shown), and once inside, the particles can be separated from the gas to reduce the risk of ignition.

[0024] Fig. 4 shows a top view of the vortex separator 300 of Fig. 3. Some features are shown in dashed lines. In particular, an inlet opening 400 allows gas and particles (e.g., from a flue) to enter a cylindrical chamber 402. A tube 404 opens into the vortex separator housing at one end and runs axially through the cylindrical chamber to the other end, which is closed. The tube forms one or more openings inside the cylindrical chamber, and here the end of the tube is cut off, creating a circular opening. The opening is covered here by a screen 406. The outlet opening 306 connects the cylindrical chamber to the collection basin 304.

[0025] Fig. 5 shows a further perspective view of the vortex separator 300 of Fig. 3. Here, an inlet port 500 is shown. This inlet port points, for example, to a vent (or directly into an outlet of a container of cells) to collect gas and particles.

[0026] Fig. 6 shows a further perspective view of the vortex separator 300 of Fig.3. An outer shell of the cylindrical housing has been omitted here for clarity. Arrow 600 schematically represents an exemplary path for a particle. That is, the particle, propelled by the flow of gas through a vent or other structure, enters the cylindrical chamber at 600A. At 600B, the particle (and gas) follow a spiral path inside the cylindrical chamber. That is, because the inlet opening is oriented tangentially with respect to the cylindrical chamber, the gas is directed to flow in a spiral inside the cylindrical chamber. During this movement, the heavier components of the flowing material are directed towards the outer periphery of the cylindrical chamber. As such, particles that are heavier than the gas and have greater momentum tend to move along the cylindrical surface.Finally, the particle exits the cylindrical chamber at 600°C, as the outlet opening is positioned tangentially to the cylindrical chamber. There, the particle falls into the collection basin after being separated from most of the flowing gas.

[0027] On the other hand, the flowing gas cannot escape through the containment basin because it is a closed structure. The gas escapes through another route when the pressure inside the containment basin increases. Specifically, the gas enters the tube through its opening inside the cylindrical chamber and can escape from the vortex separator to the outside (e.g., into the atmosphere). This means that the particles that were in the flowing gas are separated from the gas, reducing the risk of ignition.

[0028] A screen on the tube can prevent stray particles from entering the tube along with the gas. For example, some particles might otherwise bounce off the cylindrical wall and into the tube. In particular, the gas flow may be discontinuous due to the nature of the chemical reactions that occur during thermal events in the cells. In essence, a particle that was initially traveling inside the cylindrical chamber might come to rest on its surface when the flow subsides. When the flow increases again, the particle may be propelled in an erratic direction and bounce off the screen, but eventually exit the chamber and fall into the collection basin.

Claims

[1] Energy storage container (100) with: a plurality of containers (104) each containing electrochemical cells, the containers (104) being arranged in a vertical stack inside the energy storage container (100); a deduction (112); a plurality of outlets (110) from the containers (104) into the flue (112); a collecting basin (202, 304) and a vortex separator (204, 300) connected to the collection basin and having an inlet opening (204A, 400, 500) towards the exhaust (112), a first outlet opening (204B, 306) towards the collection basin (202, 304) and a second outlet opening (308) towards an outside of the energy storage container (100), wherein the first outlet opening (204B, 306) is adapted to allow particles to fall out at the outlet opening and into the collection basin (202, 304), while the second outlet opening is adapted to discharge upwardly directed gas to the outside. [2] The energy storage container (100) of claim 1, wherein the vent (112) is defined by first and second parallel walls, the second wall being an inner one of the parallel first and second walls and having the plurality of outlets (110) therein. [3] Energy storage container (100) according to claim 2, wherein the collecting basin (202, 304) is partially bounded by at least one partition wall (118) between the mutually parallel first and second walls. [4] The energy storage container (100) of claim 3, wherein the inlet opening (204A, 400, 500) comprises an opening (120) through the partition wall (118). [5] The energy storage container (100) of any preceding claim, further comprising an ash guard (116) partially covering at least one lowermost outlet of the plurality of outlets (110). [6] The energy storage container (100) of claim 5, wherein the ash guard (116) includes a lower enclosure (206) open at its top and a roof (208) separated by a gap from the top of the lower enclosure (206). [7] The energy storage container (100) of claim 6, wherein the gap corresponds to an outlet of the plurality of outlets (110). [8] Energy storage container (100) according to claim 5 or 6, wherein the lower enclosure (206) is wider at its bottom than at its top. [9] The energy storage container (100) of claim 8, wherein the bottom is substantially as wide as the vent (112). [10] Energy storage container (100) according to one of the preceding claims, wherein the vortex separator (204, 300) is arranged inside the collecting basin (202, 304). [11] Energy storage container (100) according to one of the preceding claims, wherein the vent (112) is arranged on a rear side of the energy storage container (100) opposite a door (102) to the plurality of containers (104). [12] Energy storage container (100) according to one of the preceding claims, wherein the vortex separator (204, 300) comprises: a housing (302) having a cylindrical chamber (402) therein; wherein the inlet opening (204A, 400, 500) passes through a shell of the cylindrical chamber (402), the inlet opening (204A, 400, 500) being arranged at a proximal end of the housing (302); a tube (404) opening into the housing (302) at the proximal end and extending axially through the cylindrical chamber (402) to a closed distal end of the housing (302); wherein the first outlet opening passes through the jacket and is located at the distal end; and wherein the collecting basin (202, 304) is arranged at the first outlet opening (204B, 306). [13] The energy storage container (100) of claim 12, wherein the vortex separator (204, 300) is configured for installation with the cylindrical chamber (402) in a horizontal orientation. [14] Energy storage container (100) according to claim 12 or 13, wherein the first outlet opening (204B, 306) points downwards and the collecting basin (202, 304) is arranged below the housing (302). [15] Energy storage container (100) according to one of claims 12 to 14, wherein the vortex separator further comprises a screen (406) at least partially covering an opening of the tube (404) inside the cylindrical chamber (402). [16] The energy storage container (100) of claim 15, wherein the screen (406) is cylindrical. [17] Energy storage container (100) according to claim 15 or 16, wherein the screen (406) extends at least from the opening of the tube (404) to the distal end. [18] The energy storage container (100) of any one of claims 12 to 17, wherein the tube (404) has a bend outside the housing (302) providing a second outlet opening (308) that is vertically oriented. [19] Energy storage container (100) according to one of claims 12 to 18, wherein the catch basin (202, 304) has an upper part having a substantially square cross-sectional profile and a lower part having a rectangular cross-sectional profile. [20] Energy storage container (100) according to claim 19, wherein the upper part is wider than the lower part.

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