EP3365616A1

EP3365616A1 - Heat exchanger, in particular a thermoelectric heat pump, for the temperature control of a battery

Info

Publication number: EP3365616A1
Application number: EP16784523.9A
Authority: EP
Inventors: Dipl.-ing. HENKE (ba) Timo; Stefan Hirsch; Manuel Wehowski
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2015-10-23
Filing date: 2016-10-21
Publication date: 2018-08-29
Also published as: US20180313584A1; WO2017068115A1; US10648709B2; DE102015220759A1; CN108351127A; CN108351127B

Abstract

The invention relates to a heat exchanger (1), in particular a thermoelectric heat pump, for the temperature control of a battery, comprising a first and a second cover (2a, 2b), between which a supporting frame (3) is arranged in a sandwiched manner, which supporting frame surrounds a passage opening (4), in which at least one thermoelectric element (22) is arranged, wherein at least one fluid channel (6) for the flow of a fluid therethrough is formed in the first cover (2a).

Description

Heat exchanger, in particular thermoelectric heat pump,

for tempering a battery

The invention relates to a heat exchanger, in particular a thermoelectric heat pump, for controlling the temperature of a battery, as well as a battery arrangement with such a heat exchanger.

The term "thermoelectricity" refers to the mutual influence of temperature and electricity and their conversion into each other. Thermoelectric materials take advantage of this influence to produce electrical energy as waste heat thermoelectric generators, but are also used in the form of so-called heat pumps when, with the application of electrical energy, heat from a lower temperature temperature reservoir to a higher temperature one to be transported.

Especially thermoelectric heat pumps found in automotive engineering in the cooling of various components such. Modern lithium-ion batteries application, which develop considerable heat during operation. However, such thermoelectric heat exchangers in the form of heat pumps can also be used in electric motor vehicles as a combined heating and cooling device, for example for tempering the passenger compartment, especially as they have a significantly higher efficiency than conventional electrical resistance heaters. The fields of application of thermoelectric heat exchangers in motor vehicles are therefore manifold in nature.

The use in a motor vehicle always leads to the requirement to produce thermoelectric heat exchangers with high efficiency and in a compact design. Heat exchangers installed in vehicles are therefore often produced in plate or layered construction, wherein the thermoelectrically active Elements are disposed within a thermally conductive housing and supplied to carry heat with an external electrical supply voltage.

It is an object of the present invention to discover new ways of developing heat exchangers with thermoelectric elements.

This object is solved by the subject matter of the independent patent claims. Preferred embodiments are subject of the dependent claims.

A heat exchanger according to the invention for controlling the temperature of a battery, in particular a thermoelectric heat pump, comprises a first and a second cover, which lie opposite one another. Between the two covers a support frame is arranged, which encloses a passage opening. At least one thermoelectric element is arranged in the through opening, and at least one fluid channel for flowing through with fluid is formed in the first cover. The second cover of the heat exchanger serves for attaching the heat exchanger to the battery to be tempered. By thermal coupling of the first cover over the support frame and the second cover to the battery to be tempered, the fluid flowing through the at least one fluid channel can deliver heat to or from the battery. Such a heat exchange between the fluid-in the case where the battery is to be cooled-can be used as a fluid or as a coolant-is assisted by the at least one thermoelectric element when operated in the manner of a heat pump. For this purpose, it is only necessary to apply to the thermoelectrically active element, an external electrical supply voltage, so that this - depending on the polarization of said electrical voltage - due to the thermoelectric Effects heat transported from the second cover to the first cover or vice versa.

The arrangement of the at least one thermoelectric element sandwiched in a support frame between two covers allows a realization of the heat exchanger with a small space requirement, in particular along a stacking direction, along which the two covers and the support frame are stacked with the at least one thermoelectric element.

As a result, the here presented, heat exchanger according to the invention allows improved temperature control of a thermally coupled battery with a very small space requirement. In particular, the inventive arrangement of the individual components of the heat exchanger allows its implementation in flat design, which on the one hand allows a flat and thus effective temperature control of the coupled battery and on the other hand greatly facilitates the arrangement of the heat exchanger in the engine block of a motor vehicle with high component density.

To improve the heat exchange between the fluid and the at least one thermoelectric element is proposed in an advantageous development of the invention, in the at least one fluid channel flow guide, in particular turbulence generating elements to arrange for the fluid flowing through the fluid channel. By means of the eddy currents or turbulences generated in this way in the fluid, an improved heat exchange of the fluid with the thermoelectric element and thus with the battery to be tempered is accompanied. Particularly suitably, the second cover can be realized as a cover plate, which is formed at least on a side facing away from the support frame substantially flat, so that it can be attached flat to the battery housing to be tempered by means of the heat exchanger battery unit. This feature of the second cover also results in improved heat exchange.

In a preferred embodiment, a plurality of clip-type fasteners are attached to an outer peripheral edge of the heat exchanger formed by the two covers and the support frame along the circumferential direction. By means of these fasteners, the two covers are pressed against each other and each against the support frame. This improves the thermal coupling of the two covers to the support frame and to the at least one thermoelectric element arranged therein.

Particularly preferably, at least one further opening can be provided in the support frame in addition to the passage opening, in which no thermoelectric element is arranged. Said further breakthrough forms between the two covers a cavity which acts as a thermal insulation between the two covers. In this way it can be ensured that the heat exchange between the two covers is largely or even exclusively via the at least one thermoelectric element. This allows precise control of the heat exchanges to be provided by the heat exchanger by providing an external electrical supply voltage applied to the at least one thermoelectric element. Particularly suitably, the support frame may comprise a frame material which comprises at least 75% of a plastic or at least 75% consists of such a plastic. Preferably, the support frame is made entirely of plastic. Thus, the first cover can be electrically isolated from the second cover. An undesirable electrical short circuit of the typically metallic battery housing via the two covers of the heat exchanger with a further, not part of the heat exchanger component made of an electrically conductive material can be avoided in this way.

In a further preferred embodiment, which is associated with particularly low production costs, the first cover is formed in two layers with a first layer facing the support frame and a second layer facing away from the support frame. In this variant, the at least one fluid channel of the channel structure is formed between the two layers.

In an advantageous development, a side facing the support frame side of the first cover, in particular the first layer, in a surface area of at least 75% flat. Particularly preferably, this side is substantially completely flat - ie completely flat except for unevenness with negligible lateral extent - formed. This property of the first cover facilitates the realization of the heat exchanger in flat construction.

In another advantageous development, the at least one thermoelectric element is a Peltier element. Such Peltier elements are commercially available in large quantities and inexpensively. Thus, in particular when using several Peltier elements considerable cost advantages in the production of the heat exchanger. A particularly high heat transfer performance can be achieved in the heat exchanger if at least two thermoelectric elements, preferably a plurality of thermoelectric elements, are arranged adjacent to one another in the passage opening. Said thermoelectric elements are preferably held by means of respective holding elements, in particular in the manner of struts, in the passage opening of the support frame. Particularly preferred, because space-saving, is a grid-like arrangement of the thermoelectric elements with at least two raster lines and at least two grid columns.

In another preferred embodiment, a sealing device is arranged between the two covers, which seals the cavity formed by the passage opening of the support frame against the external environment. In this way, the at least one thermoelectric element can be prevented from damage or destruction by contaminants present in the ambient air.

In an advantageous development, the sealing device comprises two sealing rings, which are arranged on opposite sides of the support frame and both enclose the passage opening completely circumferentially. In this way, the desired sealing can be realized on both sides of the support frame cost.

Particularly simple and thus inexpensive to manufacture is the heat exchanger, when the support frame is formed as a plastic injection molded part, in which at least one electrical conductor for supplying the at least one thermoelectric element with electrical energy from an external electrical energy source is arranged. In this variant, the at least one electrical conductors encapsulated by the plastic of the support frame. A separate, electrically insulating sheath of the electrical conductor can be omitted in this way. In a further development, a plurality of such electrical conductors can each be electrically insulated from each other by molding with the plastic of the support frame. This variant allows a simple electrical wiring of existing in the support frame thermoelectric elements with an external electrical power source.

The invention further relates to a battery arrangement with a battery housing having a battery and with a previously presented heat exchanger for temperature control of the battery, wherein the second cover for tempering the battery rests on the battery case or forms part of the battery case of the battery, or part of the Battery housing forms. The advantages of the heat exchanger explained above are thus transferred to the battery arrangement.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawing and from the associated description of the figures with reference to the drawing.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be explained in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components. The sole FIGURE 1 shows in an exploded view an example of a heat exchanger 1 according to the invention, which can be used as a thermoelectric heat pump for a battery arrangement. The heat exchanger 1 has a first cover 2 a and a second cover 2 b, which lie opposite one another along a stacking direction S. Sandwiched between the two covers 2a, 2b in the stacking direction S is a support frame 3. The support frame 3 includes a through-opening 4, in which a plurality of thermoelectric elements 22 are arranged.

As clearly shown in FIG. 1, the thermoelectric elements 22 are adjacent to one another with the formation of a grid 16 and are arranged at a distance from one another in the passage opening 4. By way of example, six thermoelectric elements 22 are shown in FIG. 1, but the number of thermoelectric elements 22 can be varied in variants of the example. In the example of FIG. 1, the grid 16 with the six thermoelectric elements comprises two grid lines 25 and three grid columns 26. As FIG. 1 further shows, the thermoelectric elements 22 can be held in the passage opening 4 by means of suitable holding elements 24. The thermoelectric elements 22 are preferably realized as Peltier elements.

In the first cover 2a is a channel structure 5 with a plurality of fluid channels 6 - in Figure 1, the possible course in the first cover 2a is schematically indicated - formed, which is designed to flow through with a fluid. Such a fluid may be a coolant or refrigerant, which serves as a cooling medium for a thermally coupled to the heat exchanger 1 battery. Said fluid can enter the channel structure 5 via a fluid inlet 7 arranged laterally on the first cover 2a and again out of the channel structure via a fluid outlet 8 which is likewise arranged laterally on the first cover 2a 5 exit. In the fluid channels 6 of the channel structure 5, for reasons of clarity, flow guide elements not shown in more detail, in particular turbulence generation elements, for the fluid flowing through the channel structure 5 can be arranged in FIG. This causes improved heat exchange of the fluid with the thermoelectric elements 22.

The second cover 2b is realized as a cover plate 9, which is formed at least on a side facing away from the support frame 3 side 10 substantially planar. This makes it possible to attach the second cover 2b to the battery housing of a battery unit to be tempered by means of the heat exchanger 1 for the purpose of highly effective thermal coupling. A housing wall 1 1 of such a battery housing of the battery to be tempered is indicated in Figure 1 in dashed lines. Also, the first cover 2 a may be formed as a cover plate 27. One or both covers 2a, 2b may be formed as a stamped or formed sheet metal part.

At a common outer peripheral edge 12 of the heat transfer, which is formed by the two covers 2a, 2b and the support frame 3, along the circumferential direction U a plurality of bracket-like fastening elements 13 may be arranged. By means of such fastening elements 13, which are shown in the exploded view of Figure 1 on the second cover 2b, the two covers 2a, 2b are pressed against each other and each against the support frame 3.

In the support frame 3 4 further openings 14 are provided in addition to the passage opening, in which no thermoelectric elements 22 are arranged. These openings 14 form between the two covers 2 a, 2 b respective cavities 15, which are used as thermal insulation between the two Ab-. covers 2a, 2b acts. In Figure 1, only a single breakthrough 14 is exemplified.

Preferably, the support frame 3 on a frame material, which consists of at least 75% of a plastic. A side 17 of the first cover 2 a facing the support frame 3, in particular the first layer, is flat in a surface area of at least 75%. In this way, good thermal contact of the first cover 2 a with the thermoelectric elements 22 is ensured. The support frame 3 is preferably formed as a plastic injection molded part, in which electrical conductor 23 is arranged for supplying the thermoelectric elements 22 with electrical energy from an external electrical energy source. The electrical conductors, indicated in the example scenario only roughly schematic, are encapsulated by the plastic of the support frame 3 and therefore do not require a separate, electrically insulating sheathing.

Preferably, the first cover 2a is formed in two layers and has one with the support frame 3 facing first layer and a second frame facing away from the support frame 3 (the two layers are not shown in Figure 1 for clarity). The channel structure 5 with the fluid channels 6 is preferably formed between the two layers.

Between the two covers 2a, 2b, a sealing device 18 may be arranged, which seals the cavity formed by the passage opening 4 against the outer environment 19 of the heat exchanger 1. For this purpose, the sealing device may comprise two sealing rings 20 which are arranged on opposite sides 21 a, 21 b of the support frame 3 and both enclose the through hole 4 completely circumferentially. From the angle of view shown in FIG. 1, only that of the two sealing rings 20 can be seen, which is arranged on the first cover 2a facing side 21 a. Preferably, the sealing rings 20 are made of an elastomer.

Claims

claims

1 . Heat exchanger (1), in particular thermoelectric heat pump, for tempering a battery,

with a first and a second cover (2a, 2b), between which a support frame (3) is sandwiched, which encloses a passage opening (4), in which at least one thermoelectric element (22) is arranged,

wherein in the first cover (2a) at least one fluid channel (6) for

Flow is formed with a fluid.

2. Heat exchanger according to claim 1,

characterized in that

in which at least one fluid channel (6) flow guide, in particular turbulence generating elements, are arranged for the fluid flowing through the fluid channel (6).

3. Heat exchanger according to claim 1 or 2,

characterized in that

the second cover (2b) is realized as a cover plate (9), which is substantially flat at least on a side (10) remote from the support frame (3), so that it is flat on the housing of a battery unit to be tempered by means of the heat exchanger (1) attachable.

4. Heat exchanger according to one of claims 1 to 3,

characterized in that

on an outer peripheral edge (12) formed by the two covers (2a, 2b) and the support frame (3) along a circumferential direction (U) of the heat exchanger (1) a plurality of bracket-like fastening elements (13) is mounted by means of which the two covers (2a, 2b) are pressed against each other and against the support frame (3).

5. Heat exchanger according to one of the preceding claims,

characterized in that

in the support frame (3) in addition to the passage opening (4) at least one further opening (14) is provided, in which no thermoelectric element (22) is arranged, so that the at least one further opening (14) between the two covers (2a, 2b) forms a cavity (15), which acts as a thermal insulation between the two covers (2a, 2b).

6. Heat exchanger according to one of the preceding claims,

characterized in that

the support frame (3) has a frame material which consists of at least 75% plastic.

7. Heat exchanger according to one of the preceding claims,

characterized in that

the first cover (2a) is constructed in two layers with a first layer facing the support frame (3) and a second layer facing away from the support frame (3), wherein the at least one fluid channel (6) is formed between the two layers.

8. Heat exchanger according to one of the preceding claims,

characterized in that

a the support frame (3) facing side (17) of the first cover (2a), in particular the first layer, in a surface area of at least 75%, preferably completely, is flat.

9. Heat exchanger according to one of the preceding claims,

characterized in that

the at least one thermoelectric element (22) is a Peltier element.

10. Heat exchanger according to one of the preceding claims,

characterized in that

at least two thermoelectric elements (22), preferably a plurality of thermoelectric elements (22), adjacent to each other in the through hole (4) are arranged and held by respective holding elements (24) in the through hole (4).

1 1. Heat exchanger according to one of the preceding claims,

characterized in that

between the two covers (2a, 2b) a sealing device (18) is arranged, which seals the cavity formed by the passage opening (4) against the outer environment (19) of the heat exchanger (1).

12. Heat exchanger according to claim 1 1,

characterized in that the sealing device (18) comprises two sealing rings (20) which are arranged on opposite sides (21 a, 21 b) of the support frame (3) and both enclose the passage opening (4) completely circumferentially.

13. Heat exchanger according to one of the preceding claims,

characterized in that

the support frame (3) is designed as a plastic injection-molded part, in which at least one electrical conductor (23) for supplying the at least one thermoelectric element (22) with electrical energy from an external electrical energy source is arranged,

wherein the at least one electrical conductor (23) is encapsulated by the plastic of the support frame (3).

14. Battery arrangement,

with a battery housing having a battery,

with a heat exchanger (1) according to one of the preceding claims, wherein the second cover (2b) of the heat exchanger (1) for tempering the battery rests on the battery housing or forms part of the battery housing.

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