Arrangement and method for temperature control of an accumulator

Abstract

Arrangement for temperature control of an accumulator (1a), comprising an accumulator housing (2) with voltage-generating cells (3) arranged therein and a fluid machine (4) which is prepared to set in motion a fluid which flows through the accumulator (1a), where a fluid circuit (5) is arranged exclusively within the housing (2) wherein at least one channel (6) is provided in the housing (2) for the fluid circuit (5).

Description

TECHNICAL AREA

[0001] The invention relates to an arrangement for temperature control of a battery, comprising a battery housing with voltage-generating cells arranged therein and a fluid machine which is prepared to set in motion a fluid which flows through the battery. The invention further relates to a method for temperature control of a battery with a battery housing and voltage-generating cells arranged therein, in which a fluid is set in motion by a fluid machine and flows through the battery. STATE OF THE ART

[0002] In today's world, there is an increasing use of electrical and electronic devices that can operate independently of a power grid. Ever more powerful devices, coupled with the desire for the longest possible operating time, necessitate increasingly powerful batteries. As a rule, these batteries should be as small and light as possible while still possessing a high energy capacity. This leads to ever-increasing packing densities and thus ever-greater energy content per unit volume. This is particularly true for electrically powered vehicles.

[0003] This necessitates efficient cooling and / or heating systems for the aforementioned batteries to dissipate the heat generated in the battery cells during charging or discharging, or to quickly heat the battery cells to operating temperature at low ambient temperatures. Several solutions for this are known from the prior art.

[0004] For example, DE 10 2008 034 886 A1 discloses a battery with several individual cells arranged in a battery housing and electrically connected in parallel and / or series. An air guide element, designed as a media-tight sealed hollow body, is arranged in the battery housing. The individual cells are thermally connected to an outer surface of the air guide element by means of a material bond, a positive connection, and / or a force connection.

[0005] Furthermore, WO 2008 / 120051 A2 discloses an accumulator with a housing comprising a first and a second section, separated from each other by a perforated plate. The first section houses the galvanic cells, while the second section is in contact with a heat sink. A coolant is circulated within the housing by a pump in a closed loop between the first and second housing sections.

[0006] In DE 10 2008 034 886 A1, heat is supplied to or removed from the battery by means of a heat transfer medium supplied from the outside and discharged to the outside. In WO 2008 / 120051 A2, on the other hand, heat is supplied to or removed from the cells by means of a heat transfer medium circulating within the casing. Both solutions thus have in common that heat is supplied to or removed from the cells by means of a heat transfer medium.

[0007] A disadvantage of these solutions is that, according to current technology, the casing is designed as a good heat conductor, meaning that at low ambient temperatures, the cells of a battery can only warm up very slowly "on their own" (i.e., due to their own heat dissipation) to a temperature level optimal for performance. Therefore, according to current technology, battery cells are often heated by an external heat source.

[0008] DE 10 2008 044 169 A1 discloses a battery module comprising a housing, at least one battery arranged in the housing, and at least one means for cooling and / or heating the at least one battery, wherein the at least one means comprises at least one heat pipe for temperature control of the at least one battery. A fluid circuit has an internal housing part and an external housing part. REVELATION OF THE INVENTION

[0009] The object of the present invention is to provide an improved arrangement for temperature control of a battery or an improved method for doing so. In particular, it aims to create a means of rapidly heating the battery cells without risking overheating them.

[0010] The object of the invention is achieved by an arrangement for temperature control of an accumulator of the type mentioned above, comprising a fluid circuit which is located exclusively within the housing and wherein at least one channel is provided in the housing for the fluid circuit.

[0011] The object of the invention is further achieved by a method for temperature control of an accumulator of the type mentioned at the outset, in which the fluid circulates exclusively in a fluid circuit within the housing and wherein at least one channel is provided in the housing for the fluid circuit.

[0012] According to the invention, the fluid is not used for heat transport, i.e., as a heat transfer medium, as in the prior art, but rather to control the heat transfer through the housing. When the fluid is moved, the heat transfer increases; when it is stationary, the heat transfer decreases. In this way, the internal temperature of the accumulator can be precisely adjusted to approximate the ambient temperature, or not, depending on the desired temperature for the accumulator. Advantageously, this does not require complex components such as heat exchangers and / or an external cooling circuit.

[0013] According to the invention, the fluid circuit is located entirely inside the housing, meaning that heat cannot be added to or removed from the system via the fluid. In a second, unclaimed embodiment, the fluid circuit runs partially outside the housing. However, this embodiment is designed such that the second embodiment is essentially thermally and energetically equivalent to the first embodiment, since no significant amount of heat is added to or removed from the fluid outside the housing, for example, because heat exchangers are omitted. Another advantage of the closed system is that no dirt can penetrate the fluid circuit, as can happen, for example, with open systems that draw in ambient air.

[0014] Because channels are provided for the fluid circuit within the housing, heat transfer can be controlled to a very low level, resulting in good insulation. This is advantageous, for example, when the battery is operated in a vehicle and needs to warm up quickly despite low ambient temperatures. This is not possible with the prior art according to WO 2008 / 120051 A2, as no channels are provided in the housing and the housing is relatively thin. Therefore, it cannot function effectively as an insulator, which is why a battery heated up significantly more slowly in winter than with the present invention. Furthermore, heat transfer fluids generally have a comparatively high heat capacity.Due to the comparatively large quantity of heat transfer fluid used in WO 2008 / 120051 A2 and its relatively high heat capacity, there is a further serious obstacle to the rapid heating of an accumulator solely due to its waste heat.

[0015] Naturally, the invention can also be used to selectively cool the accumulator. For this purpose, the system can be designed, for example, so that the accumulator can be kept at its optimal temperature, i.e., cooled, by the fluid circuit even at full power and the most unfavorable ambient temperature. If the ambient temperature and / or the accumulator power is lower, the power of the fluid machine can be reduced to maintain the target accumulator temperature.

[0016] The particular advantages of the invention arise primarily from the fact that, in the present invention, the fluid is not used for heat transport, but rather to control the insulating properties of a battery housing. The battery can therefore warm up quickly at low ambient temperatures, but does not overheat. Heating with external heat sources is thus unnecessary, though not entirely precluded.

[0017] Advantageous embodiments and further developments of the invention now result from the dependent claims as well as from the description in conjunction with the figures.

[0018] It is advantageous if the fluid circuit runs entirely away from the cells. This ensures good insulation between the cells and the battery's environment, especially when the fluid is stationary. As a result, the battery can heat up particularly quickly.

[0019] It is advantageous to use a gas, particularly air, as the fluid and a blower as the fluid machine. A gas has a relatively low viscosity, which means it can be moved in a gas cycle with relatively little energy expenditure. This allows it to be transported through relatively narrow channels without excessive pressure loss. Finally, gases generally have relatively low thermal conductivity and a relatively low heat capacity, which is beneficial, for example, for the rapid heating of a battery due to its waste heat.

[0020] It is also advantageous to use a liquid, especially water, as the fluid and a pump as the fluid machine. Due to its comparatively high conductivity, a liquid provides good coupling between the interior of the housing and the environment, i.e., a comparatively high heat transfer, especially when the liquid is moving.

[0021] It is particularly advantageous if the fluid circuit runs essentially in a horizontal direction. This is a measure to essentially prevent natural convection. In this way, very low heat transfer through the housing can be achieved when the fluid is stationary.

[0022] An advantageous arrangement includes at least one recess designed to form at least one channel together with another component of the accumulator. The channels intended for the fluid circuit can be formed within the housing, or, as in this case, they can be formed by a recess in the housing and a cover that closes this recess. The housing can therefore be a single piece or two pieces. Alternatively or additionally, a recess can also be located in the cover.

[0023] It is particularly advantageous if a housing for a voltage-generating cell of the accumulator is provided as an additional component for closing a recess. In this variant of the invention, a channel is formed by a recess and by the housing of a cell. The latter can thus provide a dual benefit.

[0024] It is particularly advantageous if the channels are shaped in such a way as to essentially prevent natural convection. In this way, very low heat transfer through the housing can be achieved when the fluid is stationary. In addition to the already mentioned essentially horizontal orientation of the channels, this also includes a corresponding shaping of the cross-section. For example, many small channels can be provided instead of one large one to reduce or essentially prevent natural convection.

[0025] It is advantageous if the maximum power output of the fluid machine is selected such that the heat transfer of the housing at maximum power in the area of ​​the channels is at least three times greater than when the fluid machine is deactivated. With this variant, the heat transfer can therefore be controlled within wide limits, which is why the arrangement according to the invention can be used in a wide temperature range.

[0026] It is particularly advantageous if the housing or other component used to close a recess in the channel area has external and / or internal cooling fins. This increases heat transfer. Especially with moving fluid, a comparatively high heat transfer rate can be achieved in this way.

[0027] It is particularly advantageous if the channels or recesses are at least partially coated with a metal layer. This reduces heat transfer by radiation. The housing therefore provides excellent insulation when the fluid is stationary. Alternatively or additionally, the side of the housing wall facing the interior and / or the side facing the environment can also be coated with a metal layer. Metallization is especially useful when the supporting structure of the housing is made of plastic, for example.

[0028] It is particularly advantageous if the housing, apart from the channels, is designed as a thermal insulator. This allows for particularly good insulation of the housing, since when the fluid is stationary, not only the channels but also the rest of the housing provide good insulation.

[0029] It is advantageous if the actual temperature of the accumulator and the ambient temperature are measured, and the fluid machine is activated and / or its power increased when the actual temperature approaches the ambient temperature, thus bringing it closer to the setpoint temperature of the accumulator. The arrangement according to the invention advantageously comprises a sensor for measuring the actual temperature of the accumulator, a sensor for measuring the ambient temperature, and a control system configured to activate the fluid machine and / or increase its power when the actual temperature approaches the ambient temperature, thus bringing it closer to the setpoint temperature of the accumulator. For example, if the ambient temperature or outside temperature is...If the ambient temperature is 0°C, the actual temperature is 40°C, and the target temperature is 25°C, then this condition is met, and switching on the fluid pump is advisable. However, if the actual temperature is 20°C, switching on the pump at the same target temperature is not advisable, as the accumulator would continue to cool down instead of warming up. As an alternative to simple on / off control, the fluid pump's output can also be adjusted according to the temperature difference between the target and actual temperatures. With a large temperature difference between the target and actual temperatures, the output is increased (provided the ambient temperature is suitable); with a small temperature difference, it is reduced accordingly.

[0030] It should be noted here that the variants and resulting advantages specified for the arrangement according to the invention apply equally to the method according to the invention and vice versa.

[0031] The above embodiments and further developments of the invention can be combined in any way. BRIEF DESCRIPTION OF THE FIGURES

[0032] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures of the drawing. These figures show: Fig. 1 a first schematically illustrated variant of the invention in which a fluid machine is arranged in the accumulator housing; Fig. 2 a second, unclaimed schematically illustrated variant in which a fluid machine is arranged outside the accumulator housing; Fig. 3 a schematic representation of how a housing can be constructed in two parts; Fig. 4 an arrangement of a large number of small channels in a housing; Fig. 5 a channel which is coated with a metal layer; Fig. 6 an example of how the fluid machine can be controlled and Fig. 7 An example of how an accumulator according to the invention can be installed in a vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0033] Fig. Figure 1 shows a first arrangement according to the invention for temperature control of a battery 1a, comprising a battery housing 2 with voltage-generating cells 3 arranged therein and a fluid machine 4, which is designed to set in motion a fluid that flows through the battery 1a along a fluid circuit 5. The fluid circuit 5 is located exclusively within the housing 2. Specifically, the bottom of the housing 2 is traversed by one or more channels 6 through which the fluid flows. This allows the heat transfer through the bottom of the housing 2 to be controlled. If the fluid flows through the channels 6, the heat transfer is relatively high; if the fluid is not moving, the heat transfer is comparatively low. To have the greatest possible influence on the heat transfer with respect to the entire battery, (thermal) insulation 8 is also provided on the side walls and the lid of the housing 2.As a result, changes in heat transfer at the base have a relatively strong effect on the heat transfer of the entire battery 1a. Finally, battery 1a also includes cell terminals 7, which conduct the electrical energy of the cells 3 to the outside.

[0034] The fluid can be, for example, a gas, especially air. In this case, the fluid machine 4 is designed as a blower. Alternatively, the fluid can be a liquid, especially water. In this case, the fluid machine 4 is designed as a pump.

[0035] Fig. 2 shows an unused accumulator 1b which corresponds to the one in Fig. The fluid machine 4 is quite similar to the accumulator 1a shown in Figure 1. In contrast, the fluid machine 4 is now located outside the housing 2. The fluid circuit 5 therefore comprises an internal housing section A and an external housing section B. The fluid machine 4 is designed such that the temperature change of the fluid in the external housing section B remains below 1°C at full power of the fluid machine 4. Thermally, the accumulator 1a and the accumulator 1b are therefore largely identical. Reasons for an externally located fluid machine 4 could be limited space inside the housing 2 or improved serviceability of the fluid machine 4. In any case, the aim is not to cool or heat the fluid outside the housing 2 compared to the inside of the housing.

[0036] In the Fig. 1 and Fig. In Figure 2, the cells 3 are shown spaced apart from the housing 2. Of course, the cells 3 can also touch the insulation 8 or the housing 2, particularly in the area of ​​the channels 6. Alternatively or in addition to the base, the side walls and / or the lid of the housing 2 could also be equipped with channels 6.

[0037] Fig. Figure 3 shows one possible way in which a channel 6 can be manufactured. A housing part 2 is shown, in which a meandering recess 9 is arranged. This is closed with another component, specifically a cover 10, so that the recess 9 forms a channel 6. The cover 10 can also be seen as part of a multi-part housing 2. It is also conceivable that, instead of the cover 10, a housing for a cell 3 of the accumulator 1a is provided if the cell 3 is directly adjacent to the housing 2. The housing of the cell 3 could thus serve a dual purpose.

[0038] A fluid machine 4 is mounted on the cover 10, which closes the fluid circuit 5. For improved heat transfer, optional cooling fins 11 can be provided on the housing 2 and / or optional cooling fins 12 on the cover 10. For example, this arrangement can be used for the accumulator 1a in the Fig. 1 can be used. However, it is also conceivable to use the arrangement upside down for accumulator 1b from the Fig. 2 to use.

[0039] As from the Fig. As can be seen in Figures 1 to 3, the channels 6 and the fluid circuit 5 preferably run in a horizontal direction. This is to prevent natural convection as much as possible and to maximize the difference between minimum heat transfer (fluid machine 4 deactivated) and maximum heat transfer (fluid machine 4 at full load). In an advantageous embodiment of the invention, the maximum power output of the fluid machine 4 is also selected such that the heat transfer from the housing 2 at maximum power in the area of ​​the channels 6 is at least three times greater than when the fluid machine 4 is deactivated. To further inhibit natural convection, the channels 6 can be shaped accordingly. For example, many small channels 6 are provided instead of one large channel, as is the case in Fig. 4 is visualized in the form of a section of a housing 2.

[0040] Optionally, the channels 6 or recesses 9 can be provided, at least partially, with a metal layer 13, as shown in Fig. Figure 5 is shown to prevent heat transfer due to radiation as much as possible. Optionally or additionally, the housing 2 can also be used on the outside or inside (i.e., in the Fig. 5 above or (below) with a metal layer.

[0041] Fig. Figure 6 now shows one way in which the fluid machine 4 can be controlled. For this purpose, the accumulator (cells 3 are shown for clarity in...) includes... Fig. (Figure 6 not shown) a sensor 14 for measuring the actual temperature of the accumulator 1a, a sensor 15 for measuring the ambient temperature, and a control unit 16 which activates the fluid machine 4 and / or increases the power of the fluid machine 4 when the actual temperature approaches the ambient temperature and thus also approaches the setpoint temperature of the accumulator 1a. For example, if the ambient temperature is 0°C, the actual temperature is 40°C, and the setpoint temperature is 25°C, then this condition is met and switching on the fluid machine 4 is beneficial. However, if the actual temperature is 20°C, switching on the fluid machine is not beneficial. As an alternative to simple on / off control, it can also be provided that the power of the fluid machine 4 is adjusted to the temperature difference between the set temperature and the actual temperature, i.e.The temperature is increased when there is a large temperature difference, provided the ambient temperature is suitable. Fig. Figure 7 shows an example of how an arrangement according to the invention can be installed in a vehicle. For this purpose, a housing 2 with channels 6 is attached to the bottom of the vehicle floor 17. The cells 3 with the cell connections 7 are located in the housing 2. Finally, an insulating layer 8 is arranged around the housing 2. The fluid machine is in Fig. 7 is not shown, but can be located both inside and outside the housing 2.

[0042] Finally, it should be noted that the components of the figures may not be shown to scale and that the individual variants depicted in the figures could also be the subject of an independent invention. Positional indications such as "right," "left," "top," "bottom," and the like refer to the depicted position of the respective component and must be adjusted accordingly if the stated position changes.

Claims

[1] Arrangement for controlling the temperature of an accumulator (1a), comprising an accumulator housing (2) with voltage-generating cells (3) arranged therein and a fluid machine (4) which is prepared to set a fluid in motion which flows through the accumulator (1a), where a fluid circuit (5) is arranged exclusively within the housing (2), wherein at least one channel (6) is provided in the housing (2) for the fluid circuit (5). [2] Arrangement according to claim 1, characterized by that the fluid circuit (5) is exclusively away from the cells (3). [3] Arrangement according to claim 1 or 2, characterized by that a gas, in particular air, is provided as the fluid and a blower is provided as the fluid machine (4). [4] Arrangement according to claim 1 or 2, characterized by that a liquid, in particular water, is provided as the fluid and a pump is provided as the fluid machine (4). [5] Arrangement according to one of claims 1 to 4, characterized by that the fluid circuit (5) runs in a horizontal direction. [6] Arrangement according to one of claims 1 to 5, characterized by at least one recess (9) which is prepared to form at least one channel (6) together with another component (10) of the accumulator (1a). [7] Arrangement according to claim 6, characterized by that a housing of a galvanic cell (3) of the accumulator (1a) is provided as a further component (10). [8] Arrangement according to one of claims 1 to 7, characterized by that the channels (6) are shaped to contain natural convection. [9] Arrangement according to one of claims 1 to 8, characterized by that the maximum power of the fluid machine (4) is selected such that the heat transfer of the housing (2) at maximum power in the area of ​​the channels (6) is at least three times as great as when the fluid machine (4) is deactivated. [10] Arrangement according to one of claims 6 to 9, characterized by that the housing (2) or the further component (10) has external cooling fins (11) and / or internal cooling fins (12) in the region of the channels (6). [11] Arrangement according to one of claims 6 to 10, characterized by that the channels (6) and / or recesses (9) are provided at least in sections with a metal layer (13). [12] Arrangement according to one of claims 1 to 11, characterized by that the housing (2) is designed as a thermal insulator (8) away from the channels (6). [13] Arrangement according to one of claims 1 to 12, characterized bya sensor (14) for measuring an actual temperature of the accumulator (1a) and a sensor (15) for measuring an ambient temperature and a control / regulation (16) which is prepared to activate the fluid machine (4) and / or to increase the power of the fluid machine (4) in the event of a large temperature difference between the target temperature and the actual temperature. [14] Method for tempering an accumulator (1a) with an accumulator housing (2) and voltage-generating cells (3) arranged therein, in which a fluid is set in motion by a fluid machine (4) and flows through the accumulator (1a), where the fluid circulates exclusively in a fluid circuit (5) within the housing (2) and wherein at least one channel (6) is provided in the housing (2) for the fluid circuit (5). [15] Method according to claim 14, characterized bythat it is designed to control or regulate the heat transfer through the housing (2) by means of the fluid circuit (5). [16] Method according to claim 14 or 15, characterized by that an actual temperature of the accumulator (1a) and an ambient temperature are measured and the fluid machine (4) is activated and / or the power of the fluid machine (4) is increased if there is a large temperature difference between the target temperature and the actual temperature.

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