Patent Application
20130014923
This application claims the benefit of German Provisional Patent Application No. DE 10 2011 052 839.0 filed Jul. 14, 2011, and German Utility Patent Application No. DE 20 2012 102 349.0 filed Jun. 26, 2012, the entire disclosures of which are hereby incorporated herein by reference.
This invention pertains to a battery cooler with means for cooling and heating batteries using a heat transferring fluid. The battery cooler is provided with an arrangement including at least one structure plate and one support plate for the battery cells.
Presently known battery coolers serve to temper battery cells of a vehicle battery, preferably for electro or hybrid vehicles. Both a cooling function and a heating function can be required by the battery cells. The battery cooler can be operated with a heat transfer fluid such as a phase changing refrigerant or a liquid heat carrying medium, for example. Heat flows are transferred by heat conduction between a heat exchanger and the battery cells, and vice versa, respectively.
In prior art, the battery cells are tempered using heavy, massive battery coolers that also provide structural, or supporting functions. Often times, the heat transfer fluid, as to its function, is established as a cooling medium or refrigerant, being transported in one or several flow channels through the battery cooler.
DE 10 2008 034 869 discloses a battery. The battery is provided with several battery cells forming a cell compound system and a cooling body connected to the battery cells over heat conducting elements. The cooling body has line-like flow channels arranged over a plane of the cooling body in a meanding pattern. There is no mention of a manufacture of the cooling body.
DE 10 2008 059 955 relates to a process for a manufacture of a cooling body with an integrated flow channel for a battery. A line-like meander-shaped flow channel is produced using a chipless forming technology.
EP 2 149 771 discloses a device for cooling a heat source using a cooling body provided with several pairs of forward and backward flow channels arranged side by side in a cooling body. The cooling body includes several layers of metallic plates. The metallic plates have different cut-outs punched out or are laser cut to form line-like flow channels.
Typically the battery coolers, in addition to the cooling function, have a function to hold very heavy batteries. Therefore, the battery coolers are also designed to be large to provide support to the batteries. Such large battery coolers require excessive installation space and disproportionately contribute to a total weight of the batteries. Moreover, a danger with such large battery coolers is that the refrigerant or the coolant, respectively, does not homogeneously temper the individual cells of the batteries, which may result in less than optimum operation of the batteries.
It is the objective of this invention to provide a battery cooler which minimizes installation space, while being easy to manufacture, economical in material consumption, and structurally robust.
In concordance and agreement with the present invention, a battery cooler which minimizes installation space, while being easy to manufacture, economical in material consumption, and structurally robust, has been surprisingly invented.
In one embodiment, a battery cooler, comprises: at least one support plate; and at least one structure plate coupled to the at least one support plate, the at least one structure plate including a flow channel for receiving a fluid therein, wherein a cross-section of the flow channel has a width greater than a height thereof, the flow channel including a plurality of webs, wherein one of the webs is disposed adjacent another one of the webs in respect of a direction of flow of the fluid, and the webs decrease the cross-section of the flow channel.
In another embodiment, a battery cooler, comprises: at least one support plate; and at least one structure plate coupled to the at least one support plate, the at least one structure plate including a flow channel for receiving a fluid therein, wherein the flow channel has a multi-flow configuration and includes a plurality of webs, wherein one of the webs is disposed adjacent another one of the webs in respect of a direction of flow of the fluid, and the webs decrease the cross-section of the flow channel.
In yet another embodiment, an assembly of a battery cooler, comprises: at least one mounting frame provided with at least one terminating plate; and a plurality of structure plates configured to be urged against each other by the at least one terminating plate, each of the structure plates including a flow channel for receiving a fluid therein, wherein the flow channel has a multi-flow configuration and includes a plurality of webs, wherein one of the webs is disposed adjacent another one of the webs in respect of a direction of flow of the fluid, and the webs decrease the cross-section of the flow channel.
The invention relates to a battery cooler with means for cooling and heating batteries using a heat transfer fluid, wherein the arrangement is provided with at least one structure plate and one support plate that limit a flow channel upwards and down. The invention is based on a double- or multi-flow flow channel formed in the structure plate through lateral channel boundaries, with the flow channel established flat as a specific feature of the invention, which means that a cross-section of the flow channel is established more than double a width than a height.
The invention is advantageously in that the structure plate includes several island-like webs are formed after each other in direction of flow, pillar-like fixing a distance between the structure plate and the support plate. The webs are passed around by the fluid in such way that the webs reduce a flow cross-section in sections so that the fluid is eddied over the total flow cross-section. Thus, avoiding unhomogeneous cooling. At the end, the elongated webs are deviating structures that can be used to specifically control the flow of the fluid in the battery cooler.
An advantageous embodiment of the invention is that the webs in the flow channel on the structure plate are arranged side by side at right angles to the direction of flow and disposed in groups. Preferably, each group of the webs is offset in relation to the adjacent group in respect of the direction of flow of the fluid by half a lateral distance of the webs normal to the direction of flow.
According to an embodiment of the invention, the support plate is located opposite to the structure plate, which may be formed either as a structure plate or as a flat plate.
Further, when the support plate is formed as the structure plate, the webs on both the structure plates are disposed such that the webs are preferably connected to the corresponding webs on the structure plate being opposite.
The structure plate can be manufactured through a deep drawing, stamping or hydroforming process. For a preferred brazing connection, the flat plate, the structure plate or both plates are provided with a braze material coating. It has shown useful and advantageous to connect the two plates by a brazing process, which enables obtaining a very good surface and flatness of the battery cooler.
The invention is advantageously further developed in that a pipe connection is provided on the support plate. Depending on the design, the pipe connection can be placed on the flat plate or on one of the structure plates.
In a preferred embodiment, geometry of the flow channel on the structure plate of the battery cooler is mirror-symmetric in relation to the longitudinal axis of the battery cooler so that when on operation internal pressure is applied warping is avoided. Also, in brazing or adhesive bonding processes, both plates expand identically as to a thermal behaviour so that a higher degree of flatness of the battery cooler is obtained.
It has been useful and advantageous that the webs of the structure plate, seen in top view, are established to have a circular or elliptic cross-section.
Advantageously, the invention is further developed in that during assembly the structure plates are held and pressed together by two mounting frames and two terminating plates accompanying the frame, wherein the structure plates are held in position by two pins in a fixed point and an elongated hole of the mounting frame, with the fixed point and the elongated hole in the symmetry axis of the structure plate.
Another feature of the invention is that the flow channel is routed multi-flow in order to balance the overheating of the refrigerant problematic for refrigerant cooling.
The number of flows is defined as the number of the straight sections of the flow channel that run substantially parallel to the longitudinal axis of the structure plate. In a two-flow embodiment, therefore, a single counterflow is produced. Correspondingly, in multiple-flow embodiments an (N−1)-fold counterflow is designable. Preferably, however, even-numbered flows with corresponding odd-numbered counterflows are produced to enable locating feed-throughs and the pipe connection for the inlet and outlet of the heat transfer fluid on one side of the support plate.
This measure of optimization results in that the flow channel with fluid heated at the end of the heat transfer process is adjacent to a flow channel with cooler fluid such that already within the plane of the battery cooler possible peak temperatures can balance. In the frame of this concept, again different alternatives are possible to arrange the flow channel in one or several serpentines running through the battery cooler.
This structure, on the one hand, leads to that the fluid is over a larger area in contact to the positions where the battery elements are attached and, on the other hand, that the fluid is eddied due to the offset webs so that no resting flow islands (dead water regions) can form that can lead to local overheating.
A specific advantage of the inventive solution is that the structure plates together form a supported sandwich structure, therefore being more rigid than comparable systems of prior art, so that the plates can be designed correspondingly thinner. Therefore, the battery cooler is integratable into the battery module without the demand that the battery cooler has to additionally perform structural functions, which means that no additional reinforcements of the battery cooler are needed. Thus, the installation space required for the battery cooler and the weight of the battery cooler is minimized, which results in a relatively high efficiency of the entire battery module.
The large and very even heat transferring surface of the battery cooler removes high amounts of thermal power from the battery elements so that at the battery module a low temperature level is settable. Further, the battery elements are mountable to the battery cooler applying only relatively low pressing forces.
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiment when considered in the light of the accompanying drawings in which:
The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.
The structure plate 2 is provided with a fluid connection position 6 such that at a corresponding position on the support plate 3 two feed-throughs 5 are provided. At the position of the feed-throughs 5 on the outside of the support plate 3, the pipe connection 4 is attached. The pipe connection 4 facilitates a connection of the battery cooler 1 to a fluid cooling circuit (not shown) of a motor vehicle (not shown).
A material thickness of the structure plate 2, in comparison with that of the support plate 3, can be relatively thin, as the brazed connection of webs 9 of the structure plate 2 to the support plate 3 results in an improved rigidity of the battery cooler 1. This embodiment is particularly advantageous if a refrigerant is used as fluid that evaporates at pressures in the flow channel different from the ambient pressure.
Within the flow channel 8, the webs 9 are arranged in rows crosswise to the direction of flow with each of the rows crosswise offset in the direction of flow by half a web distance. From this arrangement two effects follow: first, a change of a velocity of flow as the webs 9 reduce a flow cross-section and second, a change of the direction of flow as the webs 9 are also disposed to form flow guiding structures. Both effects result in an advantageously turbulent flow, wherein it is ensured that no resting flow islands develop that can lead to local overheating.
It has shown useful and advantageous that a channel boundary 7 is provided with several bulges 15 at equidistant positions so that a larger connection area develops for brazing. In addition to a function of the webs 9, the bulges as broadened channel boundaries 7, by analogy to the webs 9, also fulfill the functions of narrowing the cross-section and guiding the flow.
For manufacture, terminating plates 10 each is provided with a hole 12 and two elongated holes 13 for coupling (i.e. brazing or adhesive bonding) to a mounting frame 11 using appropriate pins 14. In certain embodiments, during thermal curing of the adhesive or brazing of the battery cooler 1, the elongated holes 13 allow an independent thermal expansion of the structure plates 2. Both terminating plates 10 are fixed through the pins 14 and the holes 12 that form fixed points so that the plates 10 cannot displace with respect to each other over the pins 14 in the elongated holes 13. From the positioning of the elements in relation to each other, a substantially flat battery cooler 1 results. Because high forces are not required to hold the plates 10 in position, lower pressing forces are needed during bonding or brazing, which results in a smaller weight of the mounting device. Finally, a clearly shorter process time results from the lower thermal mass of the production plant.
A particularly advantageous embodiment of the invention results from that the battery cooler 1 between the terminating plates 10 is provided with an inner layer structure formed of several pairs of structure plates 2 placed over each other, with the topmost support plate 3 established as a flat plate.
From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011 051 839.8 | Jul 2011 | DE | national |
| 20 2012 102 349.0 | Jun 2012 | DE | national |
