DE202014010473U1 - Passive temperature control of batteries through two-phase heat transfer and storage - Google Patents

Abstract

Battery or accumulator (8), comprising - at least one battery cell (1, 1A, 1B, 1C, 1D, 1E) and - a temperature control for the battery cells (1, 1A, 1B, 1C, 1D, 1E), characterized in that the temperature control: - at least one vapor chamber (2, 2A, 2B) which is in direct contact with the surface of the at least one battery cell (1, 1A, 1B, 1C, 1D, 1E) with a first battery contact surface (4), and Heat pipes (10) partially on a second Wärmeleitrohrkontaktoberfläche (4) of the vapor chamber (2, 2A, 2B) are arranged and lead out of the battery (8) to a heat exchanger (20) has.

Description

The invention relates to a battery with a temperature control.

It is common today to use batteries (accumulators) for the caching of electrical energy for needs. Typical applications are home batteries, Noffallbatterien, but especially also hybrid vehicles and electric vehicles, including rail vehicles and aircraft.

Batteries have optimum operating temperature ranges, and it is known that battery performance decreases sharply if the temperature is too low, and if the temperature is elevated, possible decomposition of the battery, including fire / oxidation, may occur.

In order to set an optimal working temperature range for such batteries, various solutions are proposed.

JP3050051 discloses an air conditioner for electric vehicles, wherein the cooling or heating of the battery can be done by air cooling.

The JP3733682 teaches a battery temperature control device that can be used to cool or heat up a vehicle drive battery in a battery case by introducing air into the battery case for a car interior air system, housed inside an introduction passage.

The Japanese Patent Application (Kokai) No. 10-32021 describes a battery with a heat-insulating material, and the use of an auxiliary heater, such as an electric heater, to maintain a suitable operating temperature of the battery in the cold.

The disclosed Japanese Patent Application (Kokai) No. 2006-269426 discloses a battery having a plurality of battery units, wherein partition walls are arranged side by side between the battery units, a housing in which the battery units and the partition wall are installed, and an inlet and an outlet through which a heat transfer medium flows, and a PTC heating element between the partition wall and the battery unit

DAIMLER proposes for this purpose in the DE102010013025 Heat transfer plates, which are connected to heat pipes, which quickly transport the heat out of the battery.

Also the DE 102012220873 A1 recommends the use of heat pipes for quick heat removal from the battery. DE 102012200401 A1 The Zahnradfabrik Friedrichshafen uses two-dimensional heat pipes or vapor chambers, which absorb the heat of the battery cells and dissipate this heat at their end faces to collectors. It has also been tried to store the waste heat from batteries for later use in heat storage ( JP2001236145A and DE102011105366 A1 ) The previous heat control of batteries could be improved.

Technical problem

It is an object of the invention to improve the previous thermal control of batteries and in particular to avoid the loss of heat energy within a system that uses the battery.

The object is achieved by a battery assembly with the features of patent claim 1. Advantageous developments emerge from the dependent claims.

A generic battery or accumulator has at least one battery cell and a temperature control for the battery cells, wherein the temperature control: at least one vapor chamber, which is in direct contact with the surface of the at least one battery cell with a first battery contact surface and heat pipes, partially on a second Wärmeleitrohrkontaktoberfläche the vapor chamber are arranged and lead out of the battery to a heat exchanger having.

As a result of this passive heat control, heat can be led out of the battery very quickly if necessary, and overheating of the same during charging or due to leakage currents in the case of material defects can be avoided. This is particularly useful for Li cells, as they can easily ignite and lead to fires. Some spectacular accidents involving these battery types in electric cars, laptops, and other mobile devices have made these major security bps. To be subjected to air traffic. Since chemical reactions responsible for the battery fires are exothermic and require heat of reaction, rapid heat dissipation of these batteries can increase their safety.

It is also known that batteries generally have a working temperature range in which they operate optimally. Therefore, it makes sense to keep them within the desired temperature range.

According to the invention, the heat absorption surface of the vapor chamber between two Battery cells arranged a battery and adapted to this for optimum heat transfer. For example. For example, the heat pipe contacting surface of the vapor chamber may have recesses for receiving the heat pipe inner sections to produce a larger heat transfer area between the heat pipe and the vapor chamber with better heat transfer.

The selection of the heat pipes is possible for those skilled in the field of heat pipes due to its expertise according to the requirements (explosion safety and / or high efficiency and / or legal requirements and spatial conditions) without inventive step and they can be selected from thermosyphon, heat pipes, variable Conductance heat pipes, loop heat pipes, also thermosyphon loops and capillary pumped loops (CPL), with the heat pipe outer section running in the heat exchanger and the heat pipe inside section between the battery cells running on the vapor chambers.

In a simple embodiment of the invention, which cools only the battery cells, the Wärmeleitrohrinnenabschnitt is carried out as a condensation zone and the Wärmeleitrohraussenabschnitt as the evaporation zone in the heat exchanger for heating the battery cells.

It is useful that the vapor chamber is at least partially made of electrically non-conductive material and is preferably designed as an electrical insulator between the Vaporchamber contact portion and the Vaporchamberwärme leitrohrkontaktfläche to avoid leakage currents.

In the temperature control system, an external heat exchanger is preferably provided for warming or warming the battery cells for regulating the battery temperature for optimizing their performance, and the heat exchanger medium is selected from: fluid materials, air, coolant from the coolant circuit, PCMs or a solid heat storage material comprising zeolite, salt hydrates or phase change material, comprising paraffins and fatty acids, and the at least one heat pipe thermally connected to the battery at one end via the vapor chamber, as a heating device, heats the battery via the vapor chamber and / or as a cooling device that houses the battery cooled over the Vapor Chamber, can work.

Depending on the use of the battery - whether mobile in vehicles of all types - weight and space requirements - or as a stationary battery in permanent or temporary structures, tent cities, as a backup battery, etc. - it is possible to select suitable heat conduction.

The at least one battery cell may be selected from rectangular columnar battery cells, laminated battery cells, and cylindrical battery cells.

In many applications, the Wärmeleitrohraussenabschnitte are connected to Wärmeleitblechen that allow rapid and large heat dissipation from the surface.

Depending on the requirements, it is also possible to use different heat pipes - both in terms of the working medium and the design.

According to the invention, sheet-like heat pipes - also called vapor chambers or heat spreaders - are arranged between the battery cells, which dissipate locally occurring heat peaks immediately over their surface. Vapor Chambers are significantly faster and more efficient than traditional heatsinks, whose thermal conductivity is slightly more than 100 times greater, allowing for extremely fast heat distribution and, together with the heat pipe, to conduct out of and into the battery.

On at least one surface of the vapor chambers heat pipes are arranged in intimate thermal contact. The surface structure of the Vapor Chamber can be designed so that it surrounds the heat pipes on three sides and thus allows a good heat transfer.

Outside the battery, the heat pipes pass through a heat accumulator, preferably a latent heat accumulator, which receives the latent heat of the working fluid of the heat pipes. It may be beneficial to use loop heat pipes, which have great heat transport capabilities.

A type of heatpipe is selected to remove heat from the battery from a given initial temperature of the battery cells, and at least one heatpipe type is selected to recover heat at a predetermined minimum temperature of the battery from the heat storage to the battery via the heat spreader supplies. By the two types of heatpipe, a battery temperature range can be adjusted and overheating and overcooling of the battery can be avoided. As a result, an increased life of the battery is achieved and their capacity is used optimally.

As latent heat storage solid storage, such as zeolites, can be used, the heat release is easily controlled but it can also fluid latent heat storage liquids are used, which are performed in a battery independent circuit - eg. A heating circuit. The use of latent heat storage depends on its capacity and - in mobile use of the battery - and its weight. By way of example, but not by way of limitation, substances which are used for latent heat storage should be mentioned, such as: salt water eutectics = 0 ° C. paraffins -30 ° C.-130 ° C. salt hydrates 5 ° C.-130 ° C. sugar alcohols 90 ° C-180 ° C - salts and their eutectic mixtures = 180 ° C and mobile latent heat storage (macro-encapsulated) with a phase-change material.Melting point of 58 ° C, inlet temperature of 56 ° C-180 ° C latent heat storage are known and are already used for various technical applications, such as house heating or motor vehicles. With regard to the latent heat storage, the full text of the book published on the Internet: http://www.buch-der-synergie.de/c_neu_html/c_10_07_e_speichern_thermisch-htm - "Book of Synergy" by Achmed AW Khammas, Rukn-Eddin, al-Buti Bldg., Damascus / Syria PO Box 2361 , referenced.

Known are bpsw. The slurries of microencapsulated phase change materials (PCM) as liquid latent storage media (s. Yasushi Yamagish1, Hiromi Takeuchi2, Alexander T. Pyatenko2, Naoyuki Kayukawa3 AIChE Journal Volume 45, Issue 4, pages 696-707, April 1999 , Such materials are commercially available from, among others, BASF SE under the brand MIKRONAL ^®. The heat can also be stored in hydrated salt crystals - eg hydrated Na2SO4, chlorides, hydrates, fluorides etc

With regard to the application in mobile systems, these have been used in motor vehicles since 1993 (Car Tech) with salts that liquefy already at 78 ° C. Other applications in vehicles are the Latentwärmespeicher used by Modine Längerer & Reich since 1997, the salts which melts at 70 ° C - by water heated by the engine, which flows through the LWS - as in a car radiator - in tubes. At the start of the cooled engine, the cooling water runs through the LWS, the salt crystallizes, and the released heat is immediately used for the heating. Another company, the VW subsidiary Votex, offers since 1997 such heat storage as a retrofit option for the Golf and the Passat. These latent heat accumulators can be easily connected to vehicle batteries.

Since heat pipes have the property to be able to transport heat bidirectionally, heat can also be transferred back from the latent heat storage - for example, to maintain a suitable working temperature for the battery.

It is also possible to use loop heat pipes, some of which run outside the battery and have a very large heat transfer capacity.

In a case where a heat pipe is used as a heat-conducting member, the working fluid may be, for example, water, ammonia, carbon dioxide, ammonia and propane, alcohol or methanol or i-propanol or mixtures thereof, this list is merely exemplary and the Invention is by no means limited thereto. Taking into account the performance and effect on the global environment, water, and alcohols and possibly mixtures thereof are preferred as working fluid of the heat pipes for mobile applications.

If required, the heat pipes can retrieve heat from the latent heat storage and also release heat there. In a preferred embodiment, the latent heat storage may be a fluid latent heat storage, such as a micro-encapsulated phase change material (PCM) that can be used at various points of a vehicle and there promoted out - for example, for heating or for heating an internal combustion engine Reduce emissions and consumption during cold start, to support heating etc.

Thus, a smooth connection to an existing Kühlmittelytem or Temperierfluidsystem done and the heat of the PCM be used where it is needed.

Preferably, the geometric arrangement of the heat pipes takes place so that gravity supports their function.

The invention will be explained with reference to the accompanying drawing, in which schematically embodiments are illustrated. The invention is by no means limited to these and the examples are given purely by way of example for better understanding. It shows:

1 is a schematic view of thermally conductively mounted on a vapor chamber heat pipes in plan view;

2 a schematic view of a cross section through the vapor chamber of 1 ;

3 a schematic representation of a heat pipe;

4 a schematic cross-sectional view of a vapor chamber;

5 schematically a section through a battery along the vapor chamber according to 1 with at the upper portion of the heat pipe connected Wärmeleitblechen, which are washed by a heat dissipation medium;

6 schematically a section through a battery along the vapor chamber according to 1 with at the upper portion of the heat pipe connected cooling fluid heat exchanger, which is flushed by a cooling fluid; and

7 schematically an arrangement similar to the 6 with attached latent heat storage.

The invention will be described in more detail below with reference to the drawing.

1 is a schematic view of a heat transfer unit according to the invention, consisting of a vapor chamber and on it - as from 2 visible - in thermal contact applied heat pipes ( 10 ). You can see the Vapor Chamber ( 20 ), which ensures an exceptionally fast heat distribution over its entire surface. This heat is dissipated from on the surface of the vapor chamber ( 20 ) thermally connected heat pipes ( 10 ) and transported outside the battery at the end.

On the Wärmeleitrohraussenabschnitt ( 5 ) can be mounted in a conventional manner Wärmeleitbleche (so-called. Fins), which are lapped by a heat-storing fluid, such as air or other gas and thus cooled. It is also possible to use this fluid for heating the battery during cold start, if it is then available tempered. Heat pipes work bidirectionally - that is, the heat transfer direction is reversed when the Wärmeleitrohraussenabschnitt ( 5 ) warmer than the Wärmeleitrohrinnenabschnitt ( 3 ) on the Vapor Chamber ( 2 . 2A . 2 B ) is thus the Vapor Chamber and warms evenly due to their high heat dissipation ability. Thus, local overheating - for example, when charging the battery, which can lead to battery / battery damage to the fire, can be avoided.

It is clear in 3 the course of the working medium in the heat pipe ( 10 to see). It is at the Wärmeleitrohrinnenabschnitt ( 3 ), enters the gaseous phase while absorbing latent heat, and condenses at the upper 5 ) with the release of latent heat, which is taken from the connected there to the pipe wall Wärmeleitblechen and to a heat transfer medium - shown here schematically with thin arrows - delivered and immediately transported away. Thus, due to the extremely high heat conduction of the heat pipes ( 10 ) Quickly remove heat from the battery cells ( 1 . 1A . 1B , AC, 1D . 1E ) and battery failure is avoided.

Batteries usually contain several battery cells ( 1 . 1A . 1B , AC, 1D . 1E ), which are regularly angeorndet. These battery cells are interconnected to a battery or accumulator.

In 5 is such an arrangement in on a vapor chamber ( 2 . 2A . 2 B ). The heat pipe ( 10 ) absorbs heat from the vapor chamber surface ( 4 ), with which it heats a liquid which, upon absorption of latent heat, turns into the gaseous state and transports the vapor to its outer end ( 5 ) with baffles, which are then traversed by a heat transfer fluid, which is gaseous or liquid. In conventional heat pipes, so-called. Thermosyphon, the liquid return is done only by gravity. In classical heat pipes is still a wick-like material in the tube - the so-called. Wick- usually a sintered body, scrim / Gerwirke or molded channels, which due to capillary action and nucleating the liquefied liquid again effectively back into the hot area of the heat pipes and bumps avoids at the Wärmeleitrohroberfläche. Therefore, heat pipes work very well with Wicks. Another embodiment is Loop-Heatipes, which return as a closed loop the cooled gas as a liquid. With regard to possible heat pipes / heatpipes is to avoid repetition on the book of David Reay and Peter Kew "Hept Pipes Theory, Design and Applications, 5th Edition, Butterworth-Heinemann - Verlag 2006 to which reference is made in full.

6 shows the use of the inventive heat transfer element in a battery or accumulator attached thereto Wärmeleitfluidleitung. You can clearly see that the heat pipes ( 10 ) run vertically and in a fluid line used as a heat exchanger - for example, end up for water. The water flows through the heat exchanger ( 20 ) with the arranged therein. Wärmeleitrohreaussenabschnitten, cools them and can then be used as warm water for heating the car or dissipate the heat in the usual way in the radiator, if it is connected to the cooling fluid line.

7 schematically shows an embodiment with latent heat storage. The heat pipe outer sections ( 5 ) give their heat to a latent heat storage unit ( 20 ) from, for example, zeolite, but also paraffins and other latent heat storage, such as acetates and other salts. The thus charged heat storage can also be liquid and belong to a latent storage fluid circuit.

LIST OF REFERENCE NUMBERS

1, 1A, 1B, 1C, 1D, 1E

battery cell

2, 2A, 2B

Vapor Chamber

3

Wärmeleitrohrinnenabschnitt

4

Vapor Chamber contact section

5

Wärmeleitrohraussenabschnitt

7

electrically insulating section of the vapor chamber

8th

Battery or accumulator

10

heat pipe

20

heat exchangers

• 
  Heat transfer medium flow
• 
  Working fluid in Vapor Chamber
• 
  heat flow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 3050051 [0005]
• JP3733682 [0006]
• JP 10-32021 [0007]
• JP 2006-269426 [0008]
• DE 102010013025 [0009]
• DE 102012220873 A1 [0010]
• DE 102012200401 A1 [0010]
• JP 2001236145 A [0010]
• DE 102011105366 A1 [0010]

Cited non-patent literature

• http://www.buch-der-synergie.de/c_neu_html/c_10_07_e_speichern_thermisch-htm - "Book of Synergy" by Achmed AW Khammas, Rukn-Eddin, al-Buti Bldg., Damascus / Syria PO Box 2361 [0029]
• Yasushi Yamagish1 *, Hiromi Takeuchi2, Alexander T. Pyatenko2, Naoyuki Kayukawa3 AIChE Journal Volume 45, Issue 4, pages 696-707, April 1999 [0030]
• David Reay and Peter Kew "Hept Pipes Theory, Design and Applications, 5th Ed., Butterworth-Heinemann - Verlag 2006 [0051]

Claims (11)

Battery or accumulator ( 8th ), with - at least one battery cell ( 1 . 1A . 1B . 1C . 1D . 1E ) and - a temperature control for the battery cells ( 1 . 1A . 1B . 1C . 1D . 1E ), characterized in that the temperature control: - at least one vapor chamber ( 2 . 2A . 2 B ) connected to a first battery contact surface ( 4 ) directly to the surface of the at least one battery cell ( 1 . 1A . 1B . 1C . 1D . 1E ) and - heat pipes ( 10 ) partially on a second Wärmeleitrohrkontaktoberfläche ( 4 ) the Vapor Chamber ( 2 . 2A . 2 B ) and from the battery ( 8th ) to a heat exchanger ( 20 ) lead out has. Battery according to claim 1, characterized in that the heat absorption surface ( 4 ) the Vapor Chamber ( 2 . 2A . 2 B ) between two battery cells ( 1 - 1A . 1B - 1C . 1D - 1E ) of a battery ( 8th ) is arranged and adapted to this. Battery according to one of the preceding claims, characterized in that the Wärmeleitrohrkontaktoberfläche ( 4 ) the Vapor Chamber ( 2 . 2A . 2 B ) Recesses for receiving the Wärmeleitrohrinnenabschnitte ( 3 ) Has. Battery according to one of the preceding claims, characterized in that the heat pipes ( 10 ) are selected from thermosyphon, heatpipe, variable conductance heatpipe, loop heatpipes, also thermosiphon loops, and capillary pumped loops (CPL), wherein the heatpipe outer section (FIG. 5 ) in the heat exchanger ( 20 ) and the Wärmeleitrohrinnenabschnitt ( 3 ) between the battery cells ( 1 . 1A . 1B . 1C . 1D . 1E ) on the Vapor Chambers ( 2 . 2A . 2 B ) is executed. Battery according to one of claims 1 to 4, characterized in that the Wärmeleitrohrinnenabschnitt ( 3 ) as the condensation zone and the Wärmeleitrohraussenabschnitt ( 5 ) as the evaporation zone in the heat exchanger ( 20 ) for heating the battery cells ( 1 . 1A . 1B . 1C . 1D . 1E ) are executed. Battery according to one of the preceding claims, characterized in that the vapor chamber ( 2 . 2A . 2 B ) is at least partially made of electrically non-conductive material and preferably as an electrical insulator ( 7 ) between the vacuum chamber ( 4 ) and Vacuumchamberwärmeleit-rohrkontaktfläche ( 5 ) is provided. Battery according to one of the preceding claims, wherein as temperature control system an external heat exchanger ( 20 ) for warming or warming the battery cells ( 1 . 1a ...) is provided for the purpose of controlling the battery temperature for performance optimization thereof and the heat exchange medium is selected from: fluid materials, air, coolant from the coolant circuit, PCKs or a solid heat storage material comprising zeolite, salt hydrates or phase change material comprising paraffins and fatty acids, and the at least one heat pipe, thermally connected to the battery at one end via the vapor chamber, heats the battery via the vapor chamber as a heater, and / or operates as a cooling device that heats the battery via the vapor chamber. A battery according to claim 1, which is equipped with a single battery cell or a plurality of aligned battery cells, wherein the heat-conducting member is disposed between adjacent battery cells. The battery according to claim 8, wherein the at least one battery cell is selected from rectangular columnar battery cells, laminated battery cells, and cylindrical battery cells. Battery according to one of the preceding claims, characterized in that the Wärmeleitrohraussenabschnitte are connected to Wärmeleitblechen. Battery according to one of the preceding claims, characterized in that different heat pipes are used.

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