Energy storage arrangement

Abstract

Energy storage arrangement (1) with several energy storage cells (3) arranged in a housing (2) and with a temperature control device (4) for cooling / heating the energy storage cells (3), - wherein the temperature control device (4) comprises a spray device (5), a drip device (5') and / or a spray device (6) by which the energy storage cells (3) can be sprayed, dripped and / or sprinkled with a temperature control fluid (8), particularly on their cell shells (7), - wherein a fluid-permeable base (9) is provided on which the energy storage cells (3) are arranged and wherein a collection tray (10) for the temperature control fluid (8) is arranged below the base (9), which has a temperature control fluid collection channel (13) inclined from a first edge (11) to an opposite second edge (12), - wherein the collection tray (10) has a tray bottom (14, 14a, 14b) inclined towards the temperature control fluid collection channel (13), - wherein a first flow (15) is provided at the first edge (11) and a second flow (16) is provided at the second edge (12), - wherein the two outlets (15,16) are connected to a valve (17) which can be controlled via a hydrostatic pressure difference.

Description

[0001] The present invention relates to an energy storage arrangement comprising at least one energy storage device and a temperature control device for cooling / heating the energy storage device. The invention also relates to a motor vehicle comprising at least one such energy storage device.

[0002] The increasing prevalence of electromobility is also driving ever-greater demands on the range and, consequently, the performance of electrical energy storage systems. To increase performance, electrical energy storage systems are already being temperature-controlled, meaning they are cooled or heated to maintain an optimal temperature range for power output. Lithium-ion batteries, in particular, require cooling or heating to prevent rapid aging. Furthermore, electric vehicles are sometimes required to have long ranges and fast-charging capabilities, which are only possible with high-performance heat exchangers. However, such modern heat exchangers require a relatively large amount of installation space and are inefficient due to the thermal path. Direct heat dissipation is particularly desirable for improved temperature control of the energy storage systems.

[0003] The present invention therefore deals with the problem of providing an energy storage arrangement that, in particular, enables improved temperature control.

[0004] This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0005] The present invention is based on the general concept of achieving improved cooling of energy storage cells in an energy storage arrangement by spraying or spraying them with temperature control fluid, and simultaneously achieving continuous temperature control of the energy storage cells with a minimal amount of temperature control fluid through a specific embodiment of the energy storage arrangement. The energy storage arrangement according to the invention comprises several energy storage cells arranged in a housing, as well as the aforementioned temperature control device for cooling or heating the energy storage cells. The temperature control device, in turn, has a spray device, a drip device, and / or a spraying device, via which the energy storage cells can be sprayed, dripped, and / or sprayed with a temperature control fluid at their cell shells, their terminals, and / or at the busbar.The energy storage cells are arranged vertically below the temperature control unit, so that the temperature control fluid sprayed or applied to the cell walls of the individual energy storage cells runs down them, ensuring relatively uniform cooling and temperature control across the height and between the different energy storage cells. A fluid-permeable base is provided below the energy storage cells, upon which the energy storage cells stand. A collection tray for the temperature control fluid is located below this base. The collection tray has a temperature control fluid collection channel that slopes from one edge to the opposite edge, with a first drain at the first edge and a second drain at the opposite edge. The base of the collection tray slopes towards the temperature control fluid collection channel.The inclined temperature control fluid collection channel ensures that the temperature control fluid flows to the first or second outlet under all typical inclines during operation of the energy storage system or a vehicle utilizing this energy storage system, at least up to an incline of + / - 30° from the horizontal. The two outlets are connected by a valve that is controlled by a hydrostatic pressure differential. The valve is designed to receive temperature control fluid exclusively from the lower outlet (depending on the position of the energy storage system). This ensures that the outlet connected to the valve is always supplied with temperature control fluid, thus reliably preventing the introduction of air, for example, by a downstream pump, and consequently, the undesirable dry running of the pump.For this purpose, the valve is connected to the first outlet via a first hydrostatic control line and to the second outlet via a second hydrostatic control line, with the valve always maintaining a communicating connection with the lower of the two outlets, since the temperature control fluid flows there and thus builds up the higher hydrostatic pressure head. With the energy storage arrangement according to the invention, a self-regulating system for the liquid cooling of individual energy storage cells within the energy storage arrangement can thus be created, which also requires an extremely small amount of temperature control fluid, which is particularly advantageous when used in hybrid or electric vehicles or in motor vehicles in general.

[0006] In an advantageous embodiment of the solution according to the invention, the valve has a first temperature control fluid inlet connected to the first outlet, a second temperature control fluid inlet connected to the second outlet, and an outlet. The valve further comprises a double piston, which alternatively closes the first temperature control fluid inlet with a first piston or the second temperature control fluid inlet with a second piston, wherein the first piston is translationally adjustable in a first cylinder section with a first pressure chamber, and the second piston is translationally adjustable in a second cylinder section with a second pressure chamber. The first pressure chamber is in turn connected to the second outlet via the aforementioned second control line, while the second pressure chamber is communicatively connected to the first outlet via the first control line.If the energy storage arrangement is positioned horizontally, the temperature control fluid flows, due to the temperature control fluid collection channel being inclined towards the second edge, to the second outlet located in the region of the second edge. With the second temperature control fluid inlet in the valve initially closed by the second piston, this creates hydrostatic pressure up to the level of the second outlet. A similar increasing hydrostatic pressure also builds up in the second control line, which leads from the second outlet to the first pressure chamber. This generates pressure in the first pressure chamber, which moves the first piston and the second piston connected to it via a piston rod. This action closes the first temperature control fluid inlet on the valve and opens the second fluid inlet. Temperature control fluid can then be supplied via the second outlet to the open second temperature control fluid inlet of the valve and from there, via the outlet, to, for example, a pump.If the vehicle, and thus the energy storage system within it, tilts in the opposite direction, so that the first edge and therefore the first outlet are lower than the second edge and the second outlet, the hydrostatic pressure in the first drain line leading from the first temperature control fluid inlet of the valve to the first outlet increases, as does the pressure in the first control line. Upon reaching a predefined pressure difference between the first and second control lines, the pressure in the first control line becomes significantly higher than in the second control line, and consequently, the pressure in the second pressure chamber becomes higher than in the first pressure chamber. This pressure then moves the second piston, closing the second temperature control fluid inlet of the valve and opening the first temperature control fluid inlet.The valve according to the invention is thus designed in such a way that it always opens the temperature control fluid inlet that is connected to the outlet in which the temperature control fluid is collecting at that time.

[0007] In an advantageous embodiment of the solution according to the invention, the two pistons are connected to each other via a piston rod. This is thus a double piston, which alternatively closes the first temperature control fluid inlet with its first piston or the second temperature control fluid inlet with its second piston. When the hydrostatic pressure in the first or second pressure chamber increases, the piston rod can move not only the respective first or second piston, but also the opposing first or second piston.

[0008] In an advantageous embodiment of the solution according to the invention, the spray device, drip device, and / or spray device has at least one fluid outlet opening, in particular a nozzle. Via such a fluid outlet opening, in particular a nozzle, it is possible to transfer a directed spray jet, drip jet, and / or a directed mist of temperature control fluid to the respective cell shell, the current collectors of the energy storage cells, and / or a busbar, thereby cooling or temperature-controlling them. The fluid outlet opening(s), in particular the nozzle(s), are preferably arranged in a cover plate, which can be part of the housing of the energy storage arrangement, or in a common rail, whereby the individual energy storage cells are sprayed from the side and above.The gravity-driven flow of the temperature control fluid film, applied (e.g., sprayed, dripped, or sprayed) to the cell shell of individual energy storage cells, allows for a relatively constant temperature across the entire height of each cell, resulting in a comparatively homogeneous temperature distribution within the cell. This method effectively eliminates temperature spikes.

[0009] In a further advantageous embodiment of the solution according to the invention, the at least one energy storage cell is designed as a cylindrical cell, i.e., a prismatic cell, or a so-called pouch cell. By designing the individual energy storage cells as cylindrical columns, a comparatively systematic arrangement of the individual energy storage cells within the housing can be achieved. Furthermore, by designing at least one energy storage cell as a so-called pouch cell or pouch bag, previously inaccessible installation space can be utilized. In general, the external shape of the individual energy storage cells is almost freely selectable, whereby care should only be taken to ensure that fluid exits through a fluid outlet opening, in particular a nozzle, the spraying device, the dripping device, or similar device.The spray device should allow the cell shell, the current collectors of the energy storage cells, and / or a busbar to be exposed to temperature control fluid over as large an area as possible. This can be done either directly by spraying, dripping, or spraying, or indirectly, provided that the sprayed or applied temperature control fluid film subsequently runs downwards along the cell shell due to gravity.

[0010] The present invention is further based on the idea of ​​using the previously described energy storage arrangement according to the invention in a motor vehicle, in particular in an electric vehicle or a hybrid vehicle, and thereby significantly increasing not only its performance but also its range. In addition, the service life of the individual energy storage units can be increased by the energy storage arrangement according to the invention due to the improved temperature control.

[0011] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0012] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0013] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0014] Each of these shows, schematically, Fig. 1 a sectional view through an energy storage arrangement according to the invention in a horizontal position, Fig. 2 a representation as in Fig. 1, however, when tilted counterclockwise, Fig. 3 A view from above of a bathtub floor.

[0015] According to the Fig. 1 and Fig. Figure 2 comprises an energy storage arrangement 1 according to the invention, comprising several energy storage cells 3 arranged in a housing 2 and a temperature control device 4 for cooling or heating the energy storage cells 3. The temperature control device 4 has a spray device 5, a drip device 5' and / or a spray device 6, via which the energy storage cells 3 can be sprayed, dripped and / or sprayed with a temperature control fluid 8 on their cell shells 7. A fluid-permeable base 9 is also provided, on which the energy storage cells 3 stand, and a collection tray 10 for the temperature control fluid 8 is arranged below this base 9. The collection tray 10 has a temperature control fluid collection channel 13 inclined from a first edge 11 to an opposite second edge 12, wherein the collection tray 10 additionally has a tray bottom 14, 14a, 14b inclined towards the temperature control fluid collection channel 13 (see also Fig. 3) At the first edge 11, a first drain 15 is arranged at the end of the temperature control fluid collection channel 13, while at the opposite edge 12, a second drain 16 is arranged at the opposite longitudinal end of the temperature control fluid collection channel 13. Both drains 15 and 16 are connected to a valve 17, which can be controlled by a hydrostatic pressure difference between the first drain 15 and the second drain 16.

[0016] If one considers the Fig. 1 and Fig. 2. Further, it can be seen that the valve 17 has a first temperature control fluid inlet 18 connected to the first outlet 15, a second temperature control fluid inlet 19 connected to the second outlet 16, and a common outlet 20. A first drain line 21 is arranged between the first outlet 15 and the first temperature control fluid inlet 18, while a second drain line 22 is arranged between the second outlet 16 and the second temperature control fluid inlet 19.

[0017] The valve 17 also has a double piston 23, which alternatively closes the first temperature control fluid inlet 18 with a first piston 24 (see Fig. 1) or with a second piston 25 the second temperature control fluid inlet 19 (see Fig. 2) The first piston 24 is translationally adjustable in a first cylinder section with a first pressure chamber 26, while the second piston 25 is translationally adjustable in a second cylinder section with a second pressure chamber 27. Both pistons 24 and 25 are connected to each other via a piston rod 28. Furthermore, a first control line 29 connected to the first outlet 15 and the second pressure chamber 27, as well as a second control line 30 connected to the second outlet 16 and the first pressure chamber 26, are provided. A continuous flow of temperature control fluid can be ensured by the valve 17 and the control lines 29 and 30 according to the invention, as described below:

[0018] If one considers the Fig. As can be seen in Figure 1, the energy storage arrangement 1 is essentially horizontally oriented, which is why one end of the temperature control fluid collection trough 13 is inclined towards the second outlet 16. For this reason, all the temperature control fluid 8 passing through the fluid-permeable bottom 9 flows along the temperature control fluid collection trough 13 to the right towards the second outlet 16, where it reaches the second temperature control fluid inlet 19 of the valve 17 via the second drain line 22. At the same time, the second control line 30, connected to the second outlet 16, is filled with temperature control fluid 8, causing a higher pressure to build up in the first pressure chamber 26 compared to the second pressure chamber 27. This pressure moves the first piston 24 and, via the piston rod 28, also the second piston 25 to the right, thereby closing the first temperature control fluid inlet 18 and keeping the second temperature control fluid inlet 19 open.The pressure in the second pressure chamber 27 is lower than in the first pressure chamber 26, since no temperature control fluid 8 enters the first control line 29 via the first outlet 15 and can cause a pressure build-up there.

[0019] If the energy storage arrangement 1 according to the invention is now constructed in accordance with the Fig. If the temperature control fluid collection channel 13 is inclined counterclockwise, such that it has a gradient towards the first outlet 15, the temperature control fluid 8 that has passed through the fluid-permeable base 9 flows exclusively to the first outlet 15 and fills the first drain line 21, which is initially closed at the valve end by the first piston 24 at the first temperature control fluid inlet 18, with temperature control fluid 8. The level of temperature control fluid 8 within the first drain line 21 rises, as does the level of temperature control fluid 8 in the first control line 29, causing the hydrostatic pressure in the first control line 29 to increase progressively. If the hydrostatic pressure in the first control line 29 is greater than in the second control line 30, the pressure in the second pressure chamber 27 increases, while the pressure in the first pressure chamber 26 decreases, since the temperature control fluid 8 slowly drains away via a process not shown.Due to the pressure difference between the first pressure chamber 26 and the second pressure chamber 27, the second piston 25, and consequently the first piston 24 (coupled to it via the piston rod 28), is displaced to the left. As a result, the second piston 25 closes the second temperature control fluid inlet 19, and the first piston 24 opens the first temperature control fluid inlet 18. Fluid-permeable end plates 31 are arranged at the end of each of the two pressure chambers 26 and 27, defining the end position of the respective piston 24 or 25. In addition to a fully open or closed position of the piston 24 or 25 with respect to the respective temperature control fluid inlet 18 or 19, the valve 17 according to the invention can, of course, also assume intermediate positions in which the first temperature control fluid inlet 18 and the second temperature control fluid inlet 19 are partially open.

[0020] A closer look at the spray device 5, the drip device 5', and / or the spray device 6 reveals that they have several fluid outlet openings 34', in particular nozzles 34, which are arranged in a cover plate of the energy storage arrangement 1 and ensure uniform spraying, dripping, or misting of the cell shells 7 of the individual energy storage cells 3. The at least one energy storage cell 3 can be designed as a cylindrical cell, a prismatic cell, or a so-called pouch cell and is preferably arranged vertically in the housing 2. The fluid-permeable base 9, in turn, can be designed as a structured perforated sheet or plate on which the energy storage cells 3 are fixed in position. Recesses arranged in the base 9 can, in particular, assist in this positional fixation.The drip tray 10, in turn, can be made of metal or plastic, in particular as a plastic injection molded part, which enables comparatively cost-effective production.

[0021] If one also considers the tub bottom 14 according to the Fig. 3, it can be seen that this has two side parts 14a and 14b, which are each inclined towards the temperature control fluid collection channel 13 and thus ensure a continuous outflow of the temperature control fluid 8 that has passed through the floor 9 in the direction of the temperature control fluid collection channel 13.

[0022] With the energy storage arrangement 1 according to the invention, which is typically arranged in a motor vehicle, for example an electric vehicle 32 or a hybrid vehicle 33, a reliable and continuous supply of temperature control fluid 8 to a pump (not shown) can be ensured without the risk of it running dry due to the vehicle's inclination. Thus, the return of the temperature control fluid 8 can be guaranteed even under varying vehicle inclinations. The control of the valve 17 is achieved exclusively via the hydrostatic pressure, i.e., the fluid level in the first control line 29 or the second control line 30, thereby eliminating the need for any further control devices, such as position sensors.The valve 17 shown requires only a small amount of vertical installation space, which is particularly advantageous for underbody mounting in a motor vehicle, as it allows for increased ground clearance. Furthermore, since the temperature control fluid 8 is continuously discharged, regardless of the vehicle's inclination, it does not accumulate, meaning that only a very small amount of temperature control fluid 8 is required.

Claims

[1] Energy storage arrangement (1) comprising several energy storage cells (3) arranged in a housing (2) and comprising a temperature control device (4) for cooling / heating the energy storage cells (3), - wherein the temperature control device (4) comprises a spray device (5), a drip device (5') and / or a spray device (6) by which the energy storage cells (3) can be sprayed, dripped and / or sprinkled with a temperature control fluid (8), particularly on their cell shells (7), - wherein a fluid-permeable base (9) is provided on which the energy storage cells (3) are arranged and wherein a collection tray (10) for the temperature control fluid (8) is arranged below the base (9), which has a temperature control fluid collection channel (13) inclined from a first edge (11) to an opposite second edge (12), - wherein the collection tray (10) has a tray bottom (14, 14a, 14b) inclined towards the temperature control fluid collection channel (13), - wherein a first flow (15) is provided at the first edge (11) and a second flow (16) is provided at the second edge (12), - wherein the two outlets (15,16) are connected to a valve (17) which can be controlled via a hydrostatic pressure difference. [2] Energy storage arrangement (1) according to claim 1, characterized by , that the valve (17) has a first temperature control fluid inlet (18) connected to the first outlet (15) via a first drain line (21), a second temperature control fluid inlet (19) connected to the second outlet (16) via a second drain line (22), and an outlet (20). [3] Energy storage arrangement (1) according to claim 2, characterized by, that the valve (17) has a double piston (23) which alternatively closes the first temperature control fluid inlet (18) with a first piston (24) or the second temperature control fluid inlet (19) with a second piston (25), wherein the first piston (24) is translationally adjustable in a first cylinder part with a first pressure chamber (26) and the second piston (25) is translationally adjustable in a second cylinder part with a second pressure chamber (27). [4] Energy storage arrangement (1) according to claim 3, characterized by , that the two pistons (24,25) are connected to each other via a piston rod (28). [5] Energy storage arrangement (1) according to claim 3 or 4, characterized by , that a first control line (29) connected to the first outlet (15) and the second pressure chamber (27) and a second control line (30) connected to the second outlet (16) and the first pressure chamber (26) are provided. [6] Energy storage arrangement (1) according to any one of the preceding claims, characterized by , that the spray device (5), the drip device (5') and / or the spray device (6) has at least one fluid outlet opening (34'), in particular a nozzle (34), which is arranged in a cover plate of the energy storage arrangement (1). [7] Energy storage arrangement (1) according to any one of the preceding claims, characterized by , that at least one energy storage cell (3) is designed as a cylindrical round cell, as a prismatic cell or as a pouch cell. [8] Energy storage arrangement (1) according to any one of claims 1 to 7, characterized by , that the fluid-permeable base (9) is designed as a structured perforated sheet or as a perforated plate, on which the energy storage cells (3) are fixed in position. [9] Energy storage arrangement (1) according to any one of the preceding claims, characterized by, that the collection tray (10) is designed as a plastic injection molded part. [10] Motor vehicle, in particular an electric vehicle (32) or a hybrid vehicle (33), with an energy storage arrangement (1) according to any of the preceding claims.

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