TW202201837A - Cooling system - Google Patents

Abstract

The present invention relates to a cooling system comprising a first sheet steel item having a first surface configured to accommodate one or more objects to be cooled, and a second surface joined to a first surface of a second steel sheet item forming a shell. In an embodiment the join may be a weld or a rivet or a plurality thereof. In one embodiment at least one of the second surface of the first sheet steel item and the first surface of the second sheet steel item have been formed to produce one or more conduits for forming one or more channels, whereby said joining forms said channels for coolant in a space between the second surface of the first sheet steel item and the first surface of the second sheet steel sheet.

Description

cooling system

The present invention relates to a cooling system formed from stainless steel sheets whose surfaces are joined to form channels for heat transfer between stainless steel sheet materials.

The invention also relates to a method for manufacturing the cooling system.

At the same time as the development of the internal combustion engine car at the end of the 19th century, researchers also developed electric vehicles, such as Werner von Siemens' electric frame (1882). Passenger cars with internal combustion engines dominated the 20th century due to their significantly greater range, availability and price of fossil fuels, and rapid refueling processes. Electric vehicles were experiencing a renaissance at the end of the 20th century as conditions such as rising prices and increasing scarcity of fossil fuels changed.

Generally speaking, electric drive vehicles use an electric drive in combination with an accompanying energy store as the drive concept. Depending on the respective drive concept, electric powered vehicles can be classified as battery electric vehicles (BEV) using pure electricity, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) or range-extended electric vehicles combining electric motors and internal combustion engines Vehicle (REEV). Also, Fuel Cell Vehicles (FCV) or Fuel Cell Hybrid Vehicles (FCHV) in which chemical energy stored in the form of hydrogen is converted into electrical energy is an additional group of electric vehicles. As an energy storage system, a high-voltage battery (battery) such as a lithium-ion battery is used as the base battery cell and is then interconnected with the modules. The various modules are joined or interconnected to form the final vehicle battery. The vehicle battery is protected by a battery compartment also known as a battery case, battery package, battery case or battery cover.

In addition to increasing battery range and protecting the battery in the event of a crash and intrusion, the topic of cooling vehicle batteries is becoming more and more important. The efficiency of temperature-sensitive lithium-ion drive batteries is about 95%. The remaining 5% represents the heat dissipation that must be dissipated, especially at higher ambient temperatures or during high voltage loads, because at battery temperatures above 35°C, the battery's charge capacity decreases and the aging process accelerates. The background is that degradation of battery cell chemical reactions accelerates and shortens component life. There is a direct relationship between temperature and chemical reactions: the higher the temperature, the faster the reaction. According to state of the art battery electric vehicles, over 7,000 battery cells are known to be integrated in the battery compartment, which increases heat dissipation. In general, cooling systems for battery compartments can be divided into direct and passive systems, depending on the location and contact of the cooling system with the battery modules. Direct cooling systems integrated into the battery compartment and in direct, more efficient contact with the battery cells or battery modules are known from US Patent Application Publication No. US2011/212356, wherein the batteries in direct contact with the battery cells or battery modules Cooling pipes are inserted between different rows of cells. Another way of arranging the cooling system would be to have an indirect cooling system around the battery compartment, which is mainly located below the battery compartment, and thus indirectly cools the entire compartment. The main disadvantage of the direct cooling system is the leakage condition, during which the fluid may come into direct contact with the energized battery, which may cause the battery to short circuit and cause a potential fire hazard. For indirect cooling systems, there is no direct contact between cooling media such as water during a crash situation, meaning that the systems are separated from each other. Additionally, the accessibility of direct cooling systems is more challenging. Another advantage of the indirect cooling design is easier access, eg, during repair or replacement of components. Also, after a crash or impact, the separate system enables faster replacement of individual components without having to destroy the entire system. From the point of view of the cooling medium, different systems are known in the state of the art: air cooling or liquid cooling using different kinds of fluids such as water, coolant or refrigerant. The ideal temperature of the battery for thermal management purposes can be defined as between 15°C and 35°C, more preferably between 20°C and 30°C.

An example of a passive, indirectly working thermal system is given in the international patent application WO 2005080902 A1, in which a cover plate designed with internal positioning tubes cools but does not heat the attachment members on the upper surface. Another example of a cooling plate is mentioned in the international patent application WO 2016096329 A1, whereby in this case the cooling plate is intended to be used as a mounting plate. Additionally, US patent application 2015/244044A1 describes a cooling plate, in this case named a hot plate manifold. German patent application 102008059947A1 describes thermally conductive plates connected to individual battery cells. US Patent Application 2017047624A1 discloses fluid channels inside a monolithic body, sidewall or base, optionally with additional cooling fins. The last mentioned patent application can be classified as a cooling plate. Such plates have the disadvantage of being dense in material, which results in a huge weight of the entire battery system, thereby indirectly reducing the battery range. In addition, since the channel is fabricated from a single piece of complete material, the material loss is high. The total volume of the following cooling channels represents waste. In addition, manufacturing by material processing techniques such as drilling, turning, milling or erosion represents an uneconomical manufacturing possibility for the high volume production of automobiles and the short cycle times required. Furthermore, the tube-intensive cooling configuration means that the material-intensive design has packaging disadvantages and a large number of necessary joining operations, especially welding.

Another way to manufacture such a cooling plate is to make it a cast assembly with an integrated channel structure. An example is given in German patent application 102015217810A1.

Furthermore, as a major condition, the limited encapsulation of the battery compartment has to be considered for electric passenger cars where the electric drive is mostly located in the underbody area of the vehicle. In the state of the art, most aluminium extruded or pressed profiles have inherent advantages of complex forms. Also, mold cast aluminum is used to create cast cooling channels in the structure of the cell compartment. An example of a widely used extruded aluminium profile is given in the international patent application WO 2018024483 A1, where the profile as a hollow chamber element is used as a heat exchanger to create a temperature control device inside the battery compartment. The device uses fluids and is divided into different tempering units, which in each case have heat exchanger surfaces with the individual battery modules. Furthermore, the thermal system is not thus separated from the battery cells in case of leakage, and the system is intensive in terms of assembly and space.

German patent application 102012012663 A1 describes a compartment, in particular a battery compartment, which is held together by a slot, a cover and a separator element located inside the slot, preferably using a material different from that used for the slot. German patent application 102012012663A1 describes lightweight materials for grooves, such as fiber-reinforced plastics with low thermal conductivity. In addition, at least one side of the groove has a protruding or recessed structure.

A battery holder for an electric vehicle is disclosed in US Patent Application Publication No. 2018/062224, which includes a slot and a cover, whereby a cooling system is integrated into the bottom of the slot. Various designs and flow patterns are shown, including parallel circuits for individual battery cells mounted in holders.

The space between the structured areas of the grooves and the separator element can be used to direct the cooling fluid. Especially during shock situations, internally disposed separator elements can have a detrimental effect because fluids can come into contact with the cells and destroy the installed cells. Shock can cause leaks due to incomplete or damaged seals. Therefore, it is desirable for the shell to have its inherent seal to protect the battery module from any external media including cooling fluids. Furthermore, the use of expensive and crash-resistant lightweight materials, such as fiber reinforced plastics, increases component costs and thus vehicle costs, while reducing safety. Furthermore, the manufacture of these materials for the above-mentioned applications is not suitable for mass production and only provides slow cycle times.

In the state of the art, different solutions exist for mould-cast aluminium, extruded aluminium or other lightweight materials such as fibre-reinforced plastics. However, there is no simple and economical system to use the advantages of flat metal sheets, especially corrosion-resistant, acid-resistant and heat-resistant stainless steel as the flat sheets of the cooling system. Furthermore, no solution exists in the state of the art using the specific processing properties of stainless steel, such as formability or welding properties, to enable new design possibilities for package-saving cooling systems in electric powered vehicles. In addition, there has not been provided a way to use flat sheet metal to benefit from a cost-effective high-volume and mature forming process for automotive mass production.

With respect to profile or bend intensive compartment designs, one of the benefits of deep drawn shell construction for battery compartments is that thermal bonding processes such as welding or brazing can be avoided, and thus avoidance of thermal deformation or by welding spatter or powder traces risk of contamination. In addition, internal thermal stress and leakage problems due to weld cracks or incomplete fusion are also avoided. In the state of the art, there are no solutions available for cooling systems that support the benefits of shell construction as a battery compartment.

According to a first aspect, the present invention relates to a cooling system comprising a first sheet of steel material having a first surface configured to receive one or more objects to be cooled, and joined to form a The second surface of the first surface of the second steel sheet material of the shell layer. At least one of the second surface of the first steel sheet material and the first surface of the second steel sheet material has been formed to create one or more conduits for forming one or more channels. The joint forms a channel for coolant in the space between the second surface of the first steel sheet material and the first surface of the second steel sheet. The channels include one or more inlet manifolds for coolant, a plurality of outlet manifolds for cooling. The plurality of outlet manifolds is one more than the one or more inlet manifolds. Each channel is connected to one or more inlet manifolds and a plurality of outlet manifolds. The plurality of outlet manifolds is one more than the one or more inlet manifolds.

According to a second aspect, the present invention relates to a method for manufacturing a cooling system. The method includes the steps of: providing a first sheet material comprising a substantially planar region having a first surface and a second surface configured to accommodate one or more objects to be cooled, providing a first surface and A second steel sheet material on the second surface, forming at least one of the first steel sheet material and the second steel sheet material to create a pipe pattern, and joining the first surface of the second steel sheet material to the The second surface of the first steel sheet material forms a channel for cooling fluid between the steel sheet materials.

According to a third aspect, the present invention relates to the use of austenitic stainless steel in the method. According to a fourth aspect, the present invention relates to the use of austenitic stainless steels in cooling systems. The fifth, sixth and seventh aspects relate to the use of cooling systems.

The present invention is defined by what is disclosed in the independent claims. Preferred specific examples are set forth in the attached claims.

Specific examples illustrating the invention

Figure 1 illustrates a cell compartment designed as a deep-drawn shell 11 with a closing plate 2, with the cell module 3 on the inside. The cooling system is directly integrated during the deep drawing of the shell. An additional flat closure plate 12 is attached to the bottom side of the shell, thereby creating a space 13 between the formed floor of the battery compartment 11 and the additional closure plate system 12, and this space 13 represents a cooling circuit.

Figure 2 illustrates the manufacture of a cooling system by means of continuous cold rolling of flat coils 8 or strips, wherein the repeating parts 9 of the cooling system are continuously rolled in the rolling direction of the coils so that at least one repeating part 9 can be Then cut to length 10.

FIG. 3 illustrates the cooling system of FIG. 1 in a top view, wherein the dashed lines indicate the battery module area 4, where the battery modules are located on the floor of the battery compartment. A manifold for the inlet 5 is provided in the middle of the battery modules, from which the individual partial circuits 6 for each battery module area branch off and, in this case, lead to both outlet manifolds Tube 7. Therefore, this satisfies the design rule that the number of manifolds for the outlet must be equal to the number of inlet manifolds plus one. Each partial circuit of the battery module area is connected to an inlet manifold and an outlet manifold.

Figure 4 illustrates a detail of Figure 1 whereby a defined distance 14 is configured between the radius of the cooling channel and the radius of curvature of the cell compartment. In addition, a defined radius 15 for part of the cooling circuit is required to allow sufficient formability of the radius on the one hand and adequate flowability of the cooling fluid on the other hand.

Fig. 5 illustrates the detail view of Fig. 3 in which the pipe bend of the partial circuit 16 has an enlarged radius in its outer side and its inner side in the cross-flow direction at the upstream end of the bend.

6 illustrates the definition of the degree of tortuosity P of individual partial loops, where tortuosity is a measure of the strength of the tortuosity of the flow system and is defined as the total length of partial loop 16 divided by the direct distance between the start and end point of partial loop 17 .

FIG. 7 illustrates another preferred embodiment of a cooling system using the manufacturing method of the present invention, such that the number of outlet manifolds 7 in this FIG. 2 is equal to the number of inlet manifolds 4 in this FIG. 3 plus one. Each partial circuit of the battery module area is connected to an inlet manifold and an outlet manifold.

It is an object of the present invention to eliminate some of the disadvantages of the prior art and to provide a cooling system. In a specific example, the cooling system is an indirect liquid-filled cooling system. In another embodiment, the cooling system is a cooling system for a battery compartment of an electric drive vehicle, which is manufactured by deep drawing or cold rolling of flat stainless steel sheets whose surfaces are formed together and subsequently In the step of joining to form a channel for heat transfer between the stainless steel sheet materials. In the context of the present invention, an indirect cooling system means that the battery module is separated from the cooling channel by the use of stainless steel sheets, and there is no contact between the liquid cooling medium and the battery itself.

In one embodiment, the cooling system includes a first steel sheet material having a first surface constructed to accommodate one or more objects to be cooled, and a second steel sheet joined to form a shell The second surface of the first surface of the material. In a specific example, the joining can be a weld or a riveting or a plurality of welds or riveting. In a specific example, at least one of the second surface of the first steel sheet material and the first surface of the second steel sheet material have been formed to create one or more channels for forming one or more channels. A plurality of pipes whereby the joint forms the passages for coolant in a space between the second surface of the first steel sheet material and the first surface of the second steel sheet. In another specific example, the coolant is a liquid, and in yet another specific example, the coolant is a gas. In one embodiment, the channel includes one or more inlet manifolds for coolant and a plurality of outlet manifolds for cooling. In a particular embodiment, the plurality of outlet manifolds is one more than the one or more inlet manifolds. For example, where there are two inlet manifolds, the number of outlet manifolds will be three, and similarly where there are three inlet manifolds, the number of outlet manifolds will be four, and so on.

In a specific example, each channel is connected to one or more inlet manifolds and a plurality of outlet manifolds, wherein the plurality of outlet manifolds is one more than the one or more inlet manifolds described above.

In a preferred embodiment, one or more inlet manifolds are positioned in the longitudinal center between the first and second steel sheet materials. In a particular embodiment, the inlet manifold is preferably located in the center of a batch of objects to be cooled. A separate partial circuit for each area of the objects to be cooled branches off from this inlet manifold and leads to an outlet manifold which is preferably located on the lateral outer side.

In one particular example, the circuit includes bends in the channels, the inner radii of the channels at the upstream ends of the bends being greater than the inner radii of the channels at the downstream ends of the bends. The difference in interior radii provides a system in which the velocity of the coolant (whether liquid or gas) increases in the channel at the downstream end of the bend compared to the upstream end of the bend. In other words, the velocity of the coolant in the channel is reduced at the upstream end of the bend compared to the downstream end of the bend. This provides a uniform and stable flow of coolant in the channels, which in turn provides improved cooling of the items to be cooled in the cooling system. The coolant flow in the channel of this particular example is compared to an individual in a water park traveling along a sealed water slide. When the radius in the bend is smaller, the person in the water slide will be pushed into the outer boundary of the curve. With an increased radius, individuals will not be pushed into the outer boundary of the curve. Nature itself solves such problems by increasing the width of meandering river channels.

In another specific example, the channel has an enlarged outer radius and an enlarged inner radius in the cross-flow direction at the upstream end of the bend. For example, in one embodiment, the diameter in the tube bend is the same or substantially the same as the diameter in the straight tube region, which helps maintain the coolant in the channel at the upstream end of the bend as compared to the downstream end of the bend speed. In a particular embodiment, the cooling system indirectly enables the object to be cooled a constant temperature range between 20°C and 35°C. In a preferred embodiment, the cooling system indirectly causes the battery modules located inside the battery compartment to have a constant temperature range between 20°C and 35°C.

In a particularly preferred embodiment, the steel sheet is austenitic stainless steel. Austenitic steels are particularly advantageous in cooling systems as described in the specific examples herein. Austenitic steels are generally non-magnetic steels, in addition to all the advantages typically provided by the use of steel sheets in cooling systems. It has good formability and weldability and excellent toughness. Austenitic grades also have lower yield stress and relatively higher tensile strength. Austenitic grades are generally more durable and corrosion resistant than other grades.

The objects to be cooled can be selected from a range of different industries. In one embodiment, the first surface of the first steel sheet is constructed to accommodate one or more objects to be cooled selected from the group consisting of: an individual battery mold Packs, battery units, engine components and control units. Cooling systems such as these may be adapted to cool and/or protect the items to be cooled during transport and/or when the items are not in use.

Another embodiment relates to a method of manufacturing a cooling system. In a first embodiment, the method includes the steps of providing a first sheet material comprising a substantially planar region having a first surface and a second surface configured to accommodate one or more individual objects to be cooled surface. The second surface may be on the same side of the substantially planar area, or the second surface may be on the opposite side of the substantially planar area, eg, on the second side of the first steel sheet. The first embodiment of the manufacturing method also includes other steps: providing a second steel sheet material having a first surface and a second surface; forming at least one of the first steel sheet material and the second steel sheet material to produce a pipe and bonding the first surface of the second steel sheet material to the second surface of the first steel sheet material, thereby forming a channel for cooling fluid between the steel sheet materials. This method of making a cooling system provides a cooling system wherein one surface of the cooling system is in conductive contact with at least one surface of the object to be cooled. One surface of the cooling system is in turn a first surface containing channels of cooling fluid, which may be liquid or gas. Thus, a system is provided that maximizes the direct heat transfer contact between the item to be cooled and the cooling fluid.

As mentioned above, the cooling system can be adapted to the various items to be cooled. In one embodiment, the method is adapted to provide a method of manufacturing a cooling system for cooling an object to be cooled selected from the group consisting of: individual battery modules, battery cells, engine components and control unit.

In one specific example, the method includes fabricating a cooling system for a battery compartment of an electric powered vehicle, preferably an electric powered vehicle selected from the group consisting of: electric passenger transport, electric freight systems, electric buses, electric commercial vehicles, electric taxis, electric parcel delivery vehicles, rail systems and ships.

In a preferred embodiment, the method includes fabricating a cooling system for a storage system, such as a tank or container for battery modules, battery cells, engine components, and control units. During transport and/or when not in use, the system can be used to cool and/or protect items to be cooled, such as battery modules, battery cells, engine components and control units.

Other embodiments of the method relate to forming a first steel sheet and a second steel sheet. In one specific example, the method includes deep drawing one or more of the first steel sheet stock and the second steel sheet stock.

In a specific embodiment, the method includes cold rolling one or more of the first steel sheet material and the second steel sheet material. In a preferred embodiment, the first sheet may be deep drawn or cold rolled, and the second sheet may be deep drawn or cold rolled. In one specific example, a first sheet is deep drawn, and a second sheet is cold rolled. In another specific example, a first sheet is cold rolled and a second sheet is deep drawn. The forming method used on each sheet may or may not be the same. In one embodiment, for example, one of the sheets is not formed by deep drawing or cold rolling, eg, is not formed at all.

In a specific example, the method includes continuously cold rolling the second steel sheet stock to create a series of repeating tubes.

In another embodiment, the method includes cutting the cold rolled material to length to obtain components of a cooling system for separation.

The cooling system includes channels of various shapes and sizes, such as can be seen from FIGS. 1-7 and 9 . In a specific example, the method includes forming bends in channels having an interior radius at an upstream end of the bend greater than an interior radius of the passage at a downstream end of the bend in the cross-flow direction. The difference in interior radii provides a system in which the velocity of the coolant (whether liquid or gas) increases in the channel at the downstream end of the bend compared to the upstream end of the bend. In other words, the velocity of the coolant in the channel is reduced at the upstream end of the bend compared to the downstream end of the bend. The change in inner radius provides a uniform and stable flow of coolant in the channels, which in turn provides improved cooling of the items to be cooled in the cooling system. The coolant flow in the channel of this particular example is compared to an individual in a water park traveling along a sealed water slide. When the radius in the bend is smaller, the person in the water slide will be pushed into the outer boundary of the curve. With an increased radius, individuals will not be pushed into the outer boundary of the curve. Nature itself solves such problems by increasing the width of meandering river channels.

In another specific example, the channel has an enlarged outer radius and an enlarged inner radius in the cross-flow direction at the upstream end of the bend. For example, in one embodiment, the diameter in the tube bend is the same or substantially the same as the diameter in the straight tube region, which helps maintain the coolant in the channel at the upstream end of the bend as compared to the downstream end of the bend speed.

Austenitic stainless steel provides at least the advantages described above compared to other suitable materials that can also be used in cooling systems. Thus, in one embodiment, the method includes providing the stainless steel sheet material as an austenitic stainless steel sheet material.

The use of cooling systems and the use of austenitic steels are also described herein. A specific example includes the use of austenitic stainless steel in a method for making a cooling system as described herein. Preferred embodiments include the use of austenitic stainless steels in the cooling systems described herein. Particular embodiments include the use of a cooling system as described herein in a battery compartment of an electrically powered vehicle. Another specific example includes the use of a cooling system as described herein in an electrically driven vehicle, preferably an electrically driven vehicle selected from the group consisting of: an electric passenger transport system, an electric cargo system, an electric Buses, electric commercial vehicles, electric taxis and electric package delivery vehicles. A specific example includes the use of a cooling system as described herein in a storage system for battery modules, battery modules, battery cells, engine components and/or control units.

Another embodiment relates to the cooling system described herein obtainable by the manufacturing method as described herein.

Taking into account the advantages of the shell construction mentioned above, according to one embodiment, the cooling system is directly integrated into the deep drawing of the first stainless steel sheet material representing the deep drawn cell compartment shell and having a three-dimensional shape forming an open channel pattern in process. In a second step, this first deep-drawn stainless steel sheet material is joined together with a second flat stainless steel sheet in the area of the open conduit pattern formed on its outer surface to generate heat transfer between the two stainless steel sheets pipes and passages. In order to enable deep drawing of the shell with an integrated cooling system, a defined distance I, having a value in the range 12.0 mm ≤ l ≤ 18.0 mm, must be configured between the radius of the cooling system and the bending radius of the cell compartment . In addition, the radius r of the partial cooling circuit is required to allow sufficient formability of the radius on the one hand and adequate flow of the cooling liquid on the other hand, and should therefore be carried out at a value in the range 2.5 mm ≤ r ≤ 9.0 mm deep drawing. Deep drawing can be performed in different drawing steps, but in as few steps as possible for a cost-effective manufacturing process. Depending on the situation, the trimming of deep-drawn components can be integrated. Figure 1 illustrates the setup of this cooling system.

Another preferred way to manufacture a cooling system using the method of the present invention is to provide a first stainless steel sheet material comprising a substantially planar area having a bottom surface and a top surface capable of accommodating at least one individual battery module. Then in a second step, a second stainless steel sheet material is formed by cold rolling to create a pipe pattern. In a third step, the second stainless steel sheet material is joined with the first stainless steel sheet material to form a channel for heat transfer between the two stainless steel sheet materials. As shown in Figure 2, a second stainless steel sheet material can be produced as a repeating part by continuous cold rolling of flat coils or strips. The repeating components include an inlet manifold section, an outlet manifold section, and at least one closed individual partial circuit. The system is formed by two cold rolling rolls in the rolling direction of the coil during the final cold rolling step of the semi-finished material, so that after at least one repeating part it is possible to depend on customer requirements (such as the desired length of the battery compartment) Perform cutting to length. This manufacturing method can further reduce the cost of components because the process and investment for the deep drawing process are eliminated. In addition, the process is scalable to different sizes and is therefore suitable for different vehicle classes. This makes the manufacturers of flat metal sheets used in the field of the present application more competitive in extruded profiles or die cast products.

The battery module is located inside the shell and is isolated from the environment by being covered with a closure plate bonded to the deep-drawn shell. The cooling system of the present invention is preferably positioned with the battery compartment on its largest side for optimal cooling behavior, in most cases represented as the bottom or top side of the compartment. For easier access during maintenance or replacement situations, the location of the cooling system is preferably on the underside of the compartment.

In the case of the present invention, the cooling system comprises: at least one inlet manifold; a plurality of outlet manifolds, the number of which is equal to the number of inlet manifolds plus one; and individual partial circuits for each battery module area, the circuits Connect to one inlet manifold and one outlet manifold. Thus, the battery module area is defined in the method of the present invention as the contact area of the battery module on the inside of the battery compartment. According to the present invention, the inlet manifold is preferably located in the center of the array of battery modules. Individual partial circuits for each battery module area branch off from this inlet manifold and lead to outlet manifolds, preferably on the lateral outer side.

Each partial circuit of the battery module area is connected to an inlet manifold and an outlet manifold. In addition, it is indicated in FIGS. 2 , 3 , 6 , and 7 that some of the loops are preferably configured in a zigzag design to achieve effective cooling of the battery module area. Thus, the well-known term tortuosity (eg, tortuosity in a river) can be used to define the amount of tortuosity of a flow system. This is illustrated in FIG. 6 . The tortuosity P can be defined by equation (1): P = L / D (1) where L represents the total flow length of a partial circuit divided by the direct distance D between the start and end points of the relevant partial circuit. The value of the tortuosity of some loops should be P≤6. In order for the fluid to flow efficiently and to avoid defects, the number of bends in the partial circuit must be minimized. Therefore, the definition of the ratio rb/l defined by equation (2) is introduced: r _b/l = b / L (2) where b represents the number of bends inside the individual partial loop, divided by its total flow length L. A suitable value can be obtained when r _b/l ≤ 0.3. Furthermore, during the forming of the stainless steel sheet, it is appropriate to form an enlarged section at the upstream end of the bend shown in FIG. 5 in the cross-flow direction. For this purpose, the outer and inner sides of the first curved section are enlarged on their radii so that the flow velocity and thus the cooling effect can be increased. With the method of the present invention, it is possible to add this feature without further effort, since it only needs to be integrated into the forming step of the stainless steel sheet material.

A flowing fluid, which is preferably water, is used, ideally with antifreeze additives, coolants or refrigerants. A preferred cooling medium is a water-glycol mixture.

Stainless steel is the preferred material choice because of its corrosion resistance, heat resistance and acid resistance, high formability and deep drawability in general, high recyclability and global availability as flat sheet combined for decades as kitchen sinks Experience with isodrawing applications was used to implement the method of the present invention. Thus, the thickness of the flat metal sheet is t ≤ 3.0 mm, more preferably 0.4 mm ≤ t ≤ 1.5 mm, to provide a compact but lightweight and cost-effective cooling system construction. In the case of the present invention, preference is given to using austenitic stainless steel, which has natural and repassivation corrosion resistance due to its chromium oxide passivation layer, and has an elongation of A80 ≥ 50%, enabling the formation of Cooling system with the mentioned distances and radii.

For the method of the invention, the mentioned joining process for producing the channels is prepared by gluing to seal the channels and avoid leakage of cooling fluid. Bonding can be done using well-known adhesives such as cold-curing two-component adhesives (2k) or heat-curing one-component adhesives (1k). In general, a cost-effective system with a fast curing process that does not require additional heat input should be preferred.

The functionality of the battery compartment is independent of the installation location within the electrically powered vehicle. Preferably, the battery compartment is located over the entire bottom to ensure maximum battery range, low center of gravity and balanced drive dynamics. Regionalized configurations such as unilateral compartments, anterior or posterior positioning will also work. In such cases, the cooling system of the present invention can be sized for different formats or desired packaging solutions.

In general, the method of the present invention is applicable to various mobility systems or transportation systems using battery modules located in battery compartments. With adjustment and scaling, the present invention is also applicable to other types of electric passenger cars or freight systems, such as electric buses, electric commercial vehicles, electric taxis or vehicles for delivering packages. It is suitable for a vehicle to use one battery compartment. But especially for long-distance transportation such as freight using trucks as an example, various battery compartments can be integrated into the vehicle to increase range. Another reason for the creation of different compartments with different support shells may be limitations on the available coil and plate width or maximum dimensions of the shell's tooling. In this case, the cooling system of the present invention can be integrated into a plurality of solutions for each compartment, and also into a single solution. The cooling effect of the present invention works independently of the type of battery used inside, such as nickel-cadmium, nickel-metal hydride, lithium ion or lithium air batteries.

none

The present invention is explained in more detail with reference to the accompanying drawings, in which [FIG. 1] shows a preferred embodiment of the cooling system implemented by deep drawing of the battery compartment as seen schematically in side view, [FIG. 2] shows another preferred embodiment of implementing a cooling system by forming a coil schematically seen in a top view (right side), [FIG. 3] shows a preferred embodiment of FIG. 1 as seen schematically in a top view, [Fig. 4] is a detail view schematically seen from Fig. 1 from the side, [Fig. 5] is a detailed view of the pipe bend as shown in Fig. 3 as seen schematically from above, [Fig. 6] illustrates the definition of the degree of tortuosity P of the individual partial loops seen in the top view, [FIG. 7] Another preferred embodiment of the present invention is shown in a top view.

Claims (21)

A cooling system comprising: The first steel sheet material, which has a first surface structured to accommodate one or more objects to be cooled, and the second surface, which is joined to the first surface of the second steel sheet material, The second steel sheet material, which forms a shell, wherein At least one of the second surface of the first steel sheet material and the first surface of the second steel sheet material has been formed to create one or more conduits for forming one or more channels, thereby The joint forms the passages for coolant in a space between the second surface of the first steel sheet material and the first surface of the second steel sheet, the passages comprising one or more inlet manifolds for coolant, a plurality of outlet manifolds for cooling, wherein the plurality of outlet manifolds is one more than the one or more inlet manifolds, Each channel is thereby connected to one or more inlet manifolds and a plurality of outlet manifolds, wherein the plurality of outlet manifolds is one more than the one or more inlet manifolds. The cooling system of claim 1, wherein the one or more inlet manifolds are positioned in the longitudinal center between the first sheet steel material and the second sheet steel material. A cooling system as claimed in claim 1 or 2, wherein the circuit comprises a bend in the passages, at the upstream end of the bend in the cross-flow direction, the passages have an enlarged radius in their outer and inner sides . The cooling system of any one of claims 1 to 3, wherein the steel sheet is austenitic stainless steel. The cooling system of any one of claims 1 to 4, wherein the first surface of the first steel sheet is constructed to accommodate one or more objects to be cooled, the one or more objects to be cooled selected from the group consisting of Groups of each: individual battery modules, battery cells, engine components, and control units. A method for manufacturing a cooling system as claimed in any one of claims 1 to 5, comprising the steps of: providing a first steel sheet material comprising a substantially planar region having a first surface and a second surface configured to accommodate one or more individual objects to be cooled, providing a second steel sheet material with a first surface and a second surface, forming at least one of the first steel sheet material and the second steel sheet material to generate a pipe pattern, The first surface of the second steel sheet material is joined to the second surface of the first steel sheet material, thereby forming channels for a cooling fluid between the steel sheet materials. The method of claim 6, wherein the object awaiting cooling is selected from the group consisting of: individual battery modules, battery cells, engine components, and control units. The method of claim 6 for manufacturing a cooling system for a battery compartment of an electrically driven vehicle, preferably an electrically driven vehicle selected from the group consisting of: Passenger systems, electric freight systems, electric buses, electric commercial vehicles, electric taxis, electric parcel delivery vehicles, rail systems and ships. The method of claim 6 for manufacturing a cooling system for a storage system such as a tank or a container for battery modules, battery cells, engine components and control units. The method of any one of claims 6 to 9, comprising deep drawing one or more of the first steel sheet material and the second steel sheet material. The method of claim 6, comprising cold rolling one or more of the first steel sheet material and the second steel sheet material. The method of claim 11 comprising continuously cold rolling the second steel sheet stock to create a series of repeating tubes. The method of claim 9 or 10, comprising cutting the cold rolled material to length to obtain components of a cooling system for separation. The method of any one of claims 6 to 13, comprising forming a bend in the passages, the passages having an outer side and an inner side thereof in a cross-flow direction at the upstream end of the bend Increase the radius. The method of any one of claims 6 to 14, wherein the steel sheet materials are austenitic stainless steel sheet materials. Use of an austenitic stainless steel in a method for manufacturing a cooling system as claimed in any one of claims 6 to 14. Use of an austenitic stainless steel in a cooling system as claimed in any one of claims 1 to 5. A use of a cooling system as claimed in any one of claims 1 to 5 in a battery compartment of an electrically driven vehicle. A use of a cooling system as claimed in any one of claims 1 to 5 in an electrically driven vehicle, preferably an electrically driven vehicle selected from the group consisting of: Electric passenger transport systems, electric freight systems, electric buses, electric commercial vehicles, electric taxis and electric package delivery vehicles. A use of a cooling system as claimed in any one of claims 1 to 5 in a storage system for battery modules, battery cells, engine components and/or control units. The cooling system of any one of claims 1 to 5, which is obtainable by the method of any one of claims 6 to 15.

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