DE102017211303B4 - Heat storage arrangement for a vehicle battery and method for its operation - Google Patents

Abstract

Heat storage arrangement (100) designed to use engine waste heat to preheat a battery (310) designed as a traction battery of an electric or hybrid motor vehicle, with a first cooling circuit (200) which has at least
- a drive motor (210) designed as an internal combustion engine and generating waste heat, wherein the waste heat is dissipated by means of a first coolant,
- a heat accumulator (230) arranged to store the waste heat contained in the first coolant,
- a heat exchanger (240) designed to utilize the waste heat contained in the first coolant, wherein the heat exchanger (240) is integrated into the first cooling circuit (200) by means of a first three-way valve (231),
- a first cooler (220) for releasing the waste heat contained in the first coolant to the environment, and with a second cooling circuit (300) which has at least
- a battery (310) designed as a traction battery of an electric or hybrid motor vehicle, arranged to store electrical energy for supplying an electric motor, wherein the battery (310) is cooled by means of a second coolant,
- a second cooler (320) designed to release heat contained in the second coolant to the environment, characterized in that the first cooling circuit (200) is fluidically coupled to the second cooling circuit (300) by means of a first and a second connecting line (410, 420), wherein the first cooling circuit (200) has a first connecting line (410) arranged downstream of the heat exchanger (240), which opens into a second three-way valve (330) which is integrated into the second cooling circuit (300) immediately upstream of the battery (310), wherein a second connecting line (420) for removing the first coolant and/or a mixture of first and second coolant is fluidically connected to the second Cooling circuit (300), wherein the second connecting line (420) opens into the first cooling circuit (200) immediately before the first pump (232), wherein the waste heat stored in the heat accumulator (230) can be used by means of the first coolant to preheat the battery (310) designed as a traction battery of an electric or hybrid motor vehicle.

Description

The present invention relates to a heat storage arrangement designed to use engine waste heat to preheat a battery, i.e. a traction battery of an electric or hybrid motor vehicle, having the features of the preamble of claim 1. Furthermore, the invention relates to a method for operating a heat storage arrangement having the features of the preamble of claim 4.

In addition to combustion engines such as diesel or gasoline engines or gas engines, alternative drive solutions are also used in modern motor vehicles. The use of electric motors in purely electric or hybrid vehicles with any degree of hybridization is particularly suitable with regard to reducing exhaust gases and pollutant emissions. In vehicles with battery-electric drives, a battery, in particular a traction battery, is required to store the electrical drive energy, possibly in addition to a fuel tank. The use of lithium-ion high-performance batteries is well known, and their optimal operating temperature is typically in a range between around 20°C and 30°C. This temperature should be kept as constant as possible to ensure a long service life of the battery.

However, motor vehicles offer a difficult environment for electrical components in both mechanical and thermal terms. The thermal integration of the electric motor, battery and power electronics leads to complex and coupled cooling systems. In hybrid vehicles, the cooling circuit of the combustion engine has so far hardly differed from that of conventional combustion vehicles. Due to different operating temperatures, the cooling circuit of a combustion engine cannot be used for the battery. Hybrid vehicles therefore require a separate cooling circuit for the battery in addition to the conventional cooling circuit for the drive motor. Depending on the drive train and battery type, different cooling circuits are appropriate for the electrical system.

On the other hand, operation at outside temperatures that are too low can lead to a shortened battery life. In vehicles with a battery-electric drive, cold starting in very cold conditions (for example, when the outside temperature is below 0°C) is a technological challenge, as the available battery power drops sharply as the temperature drops. A cold start is when the vehicle is started up again after being idle for a long time in a cold environment or when the temperature of the engine, battery or other drive-related components is below their operating temperature. Below a critical temperature limit, the vehicle can therefore no longer be operated electrically. However, especially with plug-in hybrid vehicles, the user expects to be able to start and drive the vehicle electrically, even after a long period of downtime.

The problem of cold starts has long been known in the field of motor vehicles with combustion engines. Cold starts lead to increased fuel consumption and increased emissions of pollutants, especially in diesel engines. The current state of the art provides a wide variety of options for preheating the combustion engine after a long period of downtime in order to avoid a cold start or at least to keep the warm-up phase after a cold start as short as possible.

For example, the DE 10 2011 017 764 A1 a heat storage system for a motor vehicle with an internal combustion engine to store the waste heat generated by the internal combustion engine during travel. After a longer period of downtime of the motor vehicle, the stored heat energy can be used to heat the internal combustion engine to its operating temperature. The system has a fluidic charging circuit for charging the heat storage with the engine's waste heat and a discharging circuit through which the heat stored in the heat storage is fed to the internal combustion engine.

Also from the DE 44 02 215 A1 A method for improving the cold start behavior of internal combustion engines is known. In this method, the waste heat of the internal combustion engine is stored in at least one heat accumulator, which absorbs the thermal energy of the engine oil or the cooling water. The cooling water or the engine oil itself is used as the storage medium. Before a cold start, the engine oil is pumped from the heat accumulator back into the oil pan in order to heat the internal combustion engine to operating temperature.

An alternative design of a heat storage system is, for example, EP 2 143 573 B1 This discloses a heating device for heating components of a motor vehicle, such as a radiator. The heating device has a heat accumulator that is suitable for temporarily storing an amount of heat emitted over a period of time. The heat accumulator is designed as a latent heat accumulator. Latent heat accumulators have a separate storage medium and generally use the enthalpy of reversible thermodynamic state changes. changes in the storage medium (for example the transition from the solid to the liquid phase). The stored heat can be used to heat the vehicle interior.

In the DE 10 2010 029 904 A1 It is proposed to use a fuel tank for biogenic fuel of a hybrid vehicle with a two-stroke diesel engine simultaneously as a coolant storage device and a latent heat storage device for preheating electrical components and/or the passenger compartment during a cold start of the diesel engine.

The DE 10 2014 007 214 A1 discloses a heat storage device for storing the waste heat of an internal combustion engine. The heat storage device is designed here as a so-called Ruths storage device, in which the heat storage fluid is in two phases, ie liquid and gaseous, which increases the amount of heat that can be stored. The heat stored in the fluid can be converted into mechanical energy by means of an expansion machine and fed to various vehicle components.

A recuperation arrangement with several storage units for energy recovery and energy storage in a motor vehicle is known from DE 10 2013 209 837 A1 By providing different storage units, different energy domains (electrical, chemical, electrochemical, thermal, mechanical), for example from braking, exhaust and waste heat energy, can be temporarily stored, which should increase the efficiency of the recuperation arrangement.

From the DE 10 2013 225 582 A1 A lithium battery system with an electrochemical energy storage device is known. It is proposed to store heat energy in a heat storage device, which is generated, for example, when an engine is running. In the case of a hybrid vehicle, the stored heat can be used to heat the engine and/or to control the temperature of the passenger compartment and/or to support an auxiliary heater.

A thermal management system for a vehicle having a first coolant circuit connected to the engine and a second coolant circuit suitable for heating or cooling a vehicle battery is described in the DE 10 2015 103 032 A1 proposed. The first and second coolant circuits are thermally coupled to one another via a refrigerant circuit and a heat exchanger.

The closest to the invention DE 10 2015 208 100 A1 also discloses a motor vehicle with a heat accumulator and a method for using the heat contained in the heat accumulator to heat up an internal combustion engine and/or for heating the vehicle interior. The waste heat from the internal combustion engine is fed to a heat accumulator during engine operation and is stored there. The storage medium contained in the heat accumulator can be additionally heated using an electric heater. The stored heat can be used to bring the internal combustion engine back to its operating temperature as quickly as possible after a cold start, to heat other vehicle components such as the vehicle battery or a traction battery of an electric vehicle and/or the vehicle interior. The publication does not provide any further explanations of the thermal coupling of the cooling circuit of the internal combustion engine with a cooling circuit of the vehicle battery.

A battery temperature control device for a traction battery of an electric or hybrid vehicle for heating and/or cooling a battery is described in the DE 10 2015 106 382 A1 The device has a thermochemical heat storage device and a heat transfer element for heating and/or cooling the battery. The thermal coupling between the thermochemical heat storage device and the battery to be tempered takes place via a heat transfer element.

The DE 10 2013 209 045 A1 relates to a cooling system for a hybrid vehicle comprising a low-temperature cooling circuit with a low-temperature heat source, with a low-temperature cooler and with a low-temperature pump and comprising an independently operable high-temperature cooling circuit with a high-temperature heat source, with a high-temperature cooler and with a high-temperature pump, wherein the low-temperature cooling circuit and the high-temperature cooling circuit can be coupled for the purpose of heat exchange.

The DE 10 2015 122 196 A1 relates to a cooling or heating circuit system for an electrically operated vehicle, with at least one electric motor integrated in a first cooling circuit, as well as with a battery integrated in a second cooling circuit, as well as with a connecting line which is arranged between the first and the second cooling circuit and which can be controlled by at least one switching valve, as well as with an electric charger for the battery which is integrated in the connecting line.

From the US 2008 / 0 251 303 A1 is a method for controlling a vehicle drive train which connects or keeps in connection two cooling circuits, each of which is connected to a heat engine and to at least one electrical component, via at least one valve.

The DE 10 2010 014 752 A1 discloses an arrangement which has an electrical energy storage device which is connected to a cooling circuit, and two exhaust gas release devices which are connected in series or parallel to a further cooling circuit, wherein the exhaust gas release devices release the exhaust gas during operation of the arrangement. Coupling elements connect the electrical energy storage device to the latter cooling circuit, and pump devices for supplying the coolers and/or the electrical energy storage device with coolant are connected to the two cooling circuits.

In view of the state of the art shown, there are still opportunities for improvement in the use of the waste heat of a drive motor to preheat a battery, especially during a cold start.

The invention is therefore based on the object of improving a heat storage arrangement with an engine cooling circuit and a method for operating it, in particular to create an alternative and more cost-effective possibility for heat transfer between the engine cooling circuit and a separate battery cooling circuit.

According to the invention, the object is achieved by a heat storage arrangement having the features of claim 1.

• - einen als Verbrennungsmotor ausgebildeten, Abwärme erzeugenden Antriebsmotor, wobei die Abwärme mittels eines ersten Kühlmittels abgeführt wird,
• - einen Wärmespeicher eingerichtet zur Speicherung der im ersten Kühlmittel enthaltenen Abwärme,
• - einen Wärmeübertrager eingerichtet zur Nutzung der im ersten Kühlmittel enthaltenen Abwärme, insbesondere für eine Fahrzeuginnenraumheizung, wobei der Wärmeübertrager mittels eines ersten Drei-Wege-Ventils, in den ersten Kühlkreislauf integriert ist,
• - einen ersten Kühler zum Abgeben der im ersten Kühlmittel enthaltenen Abwärme an die Umgebung,

und mit einem zweiten Kühlkreislauf, der wenigstens aufweist

• - eine als Traktionsbatterie eines Elektro- oder Hybridkraftfahrzeugs ausgebildeten Batterie, eingerichtet zur Speicherung elektrischer Energie zur Speisung eines Elektromotors, wobei die Batterie mittels eines zweiten Kühlmittels gekühlt wird,
• - einen zweiten Kühler eingerichtet zur Abgabe von im zweiten Kühlmittel enthaltener Wärme an die Umgebung,

A heat storage arrangement is shown which is designed to use engine waste heat to preheat a battery designed as a traction battery of an electric or hybrid motor vehicle, with a first cooling circuit which has at least

• - a drive motor designed as an internal combustion engine that generates waste heat, the waste heat being dissipated by means of a first coolant,
• - a heat storage device is set up to store the waste heat contained in the first coolant,
• - a heat exchanger designed to use the waste heat contained in the first coolant, in particular for a vehicle interior heating system, wherein the heat exchanger is integrated into the first cooling circuit by means of a first three-way valve,
• - a first cooler for releasing the waste heat contained in the first coolant to the environment,

and with a second cooling circuit, which has at least

• - a battery designed as a traction battery of an electric or hybrid motor vehicle, designed to store electrical energy to power an electric motor, wherein the battery is cooled by means of a second coolant,
• - a second cooler arranged to release heat contained in the second coolant to the environment,

It is proposed that the first cooling circuit is fluidically coupled to the second cooling circuit by means of a first and a second connecting line, wherein the first cooling circuit has a first connecting line arranged downstream of the heat exchanger, which opens into a second three-way valve which is integrated into the second cooling circuit immediately upstream of the battery, wherein a second connecting line for removing the first coolant and/or a mixture of first and second coolant is fluidically connected to the second cooling circuit immediately behind the battery, wherein the second connecting line opens into the first cooling circuit immediately upstream of the first pump, wherein the waste heat stored in the heat accumulator can be used by means of the first coolant to preheat the battery designed as a traction battery of an electric or hybrid motor vehicle.

Further advantageous embodiments of the invention are disclosed in the subclaims.

It should be noted that the features and measures listed individually in the following description can be combined with one another in any technically reasonable manner and show further embodiments of the invention. The description characterizes and specifies the invention, particularly in connection with the figures.

As described above, a heat storage arrangement is proposed for using engine waste heat to preheat a battery. In particular, the engine waste heat can be used to preheat a traction battery of an electric or hybrid motor vehicle with any degree of hybridization. The heat storage arrangement has a first cooling circuit, a high-temperature cooling circuit for cooling a drive motor and a second cooling circuit, a low-temperature cooling circuit to cool the battery. The drive motor is integrated into the first cooling circuit. This is an internal combustion engine (e.g. diesel or gasoline engine or gas engine). If a purely electrically powered motor vehicle is used, it could also be a liquid-cooled electric motor. During engine operation, the drive motor generates waste heat, which is dissipated by means of a first coolant, preferably water-based. The first cooling circuit also has a heat accumulator, in particular a latent heat accumulator, and a first cooler. In order to be able to retain stored heat over a sufficiently long period of time (e.g. overnight), the heat accumulator must be designed as an insulating container with sufficient thermal insulation. The coolant itself is preferably used as the heat storage medium. To load the heat accumulator with heat, it is filled with the hot coolant, in particular coolant. The first cooler is designed to release the waste heat of the drive motor contained in the coolant to the environment of the motor vehicle. The first cooling circuit may include additional components, such as pumps for pumping the first coolant, valves, temperature sensors and the like.

The second cooling circuit has at least the battery, i.e. a traction battery, and a second cooler. The battery, which is used to store electrical energy to power an electric motor, is cooled by means of a second coolant, preferably also water-based. The heat contained in the second coolant is released to the environment via the second cooler. The second cooling circuit can have further components, such as pumps for conveying the second coolant, valves, temperature sensors and the like.

As mentioned above, the first cooling circuit is fluidically coupled to the second cooling circuit. This means that the first coolant can be fed into the second cooling circuit. This means that the waste heat from the drive motor can be fed directly to the second cooling circuit without the need for a heat exchanger. Waste heat stored in the heat accumulator can also be fed directly to the second cooling circuit without the use of a heat exchanger. The waste heat stored in the heat accumulator can thus be used to preheat the battery even after the vehicle has been idle for a long time, without the drive motor being started or already being in operation.

According to a preferred embodiment, the heat accumulator has an electrical heating means that is suitable for releasing heat to a heat storage medium that is contained in the heat accumulator. The heat storage medium can be the first coolant itself or other media known from the prior art (liquid, solid, gaseous) with a high heat capacity that are suitable for storing heat. The electrical heating means is preferably designed in the manner of an immersion heater and can be supplied with energy by means of the battery and/or an external power supply. The electrical heating means heats up during operation and releases the resulting heat energy to the heat storage medium.

A heat exchanger is integrated into the first cooling circuit, which dissipates the thermal energy contained in the first coolant as an alternative to the first cooler. The heat exchanger can be used to heat various vehicle components, preferably to heat the vehicle interior. In a preferred embodiment, the heat exchanger is connected in series with the heat accumulator and is arranged behind it with respect to the flow direction of the first coolant. The heat accumulator can be bypassed by means of a first three-way valve, so that the first coolant flows from the combustion engine directly to the heat exchanger.

The fluidic coupling between the first cooling circuit and the second cooling circuit is, as already described above, implemented by means of a first and a second connecting line. The first connecting line is used to remove the first coolant from the first cooling circuit and is fluidically connected to it for this purpose. The first connecting line flows into a second, switchable three-way valve, which is integrated into the second cooling circuit. The fluidic coupling between the first and second cooling circuits can be opened or closed via the second three-way valve. The first coolant and/or a mixture of first and second coolants are removed from the second cooling circuit by means of a second connecting line and fed to the first cooling circuit. In this way, the battery can be integrated into the first cooling circuit or connected to it. In terms of the flow direction, the first connecting line flows into the second cooling circuit immediately before the battery, with the second connecting line being connected to the second cooling circuit immediately after the battery.

The process engineering aspect of the problem is solved by a method for operating a heat storage arrangement according to claim 4.

• - in einem ersten Betriebsmodus, einem Standardmodus, das erste Kühlmittel durch den Antriebsmotor und den ersten Kühler zirkuliert, wobei das erste Kühlmittel Abwärme des Antriebsmotors aufnimmt und über den ersten Kühler an die Umgebung abgibt,
• - in einem zweiten Betriebsmodus, einem Lademodus, das erste Kühlmittel durch den Antriebsmotor und den Wärmespeicher zirkuliert, wobei das erste Kühlmittel die Abwärme des Antriebsmotors aufnimmt und zur Speicherung an den Wärmespeicher abgibt,

und, das dadurch gekennzeichnet ist, dass

• - in einem dritten Betriebsmodus, einem Batterieheizmodus, das erste Kühlmittel nur durch den Wärmespeicher und die als Traktionsbatterie eines Elektro- oder Hybridfahrzeugs ausgebildete Batterie zirkuliert, wobei das erste Kühlmittel Wärme, die in dem Wärmespeicher gespeichert ist, aufnimmt und an die Batterie abgibt, um diese vorzuwärmen.

A method for operating a heat storage arrangement for the use of Engine waste heat for preheating a battery designed as a traction battery of an electric or hybrid motor vehicle, with a first cooling circuit, which has at least one drive motor designed as an internal combustion engine, a heat accumulator, a first cooler, a heat exchanger and a first coolant that circulates in the first cooling circuit, a second cooling circuit, which has at least one battery designed as a traction battery of an electric or hybrid motor vehicle, a second cooler and a second coolant that circulates in the second cooling circuit, and with at least three operating modes, wherein in

• - in a first operating mode, a standard mode, the first coolant circulates through the drive motor and the first cooler, wherein the first coolant absorbs waste heat from the drive motor and releases it to the environment via the first cooler,
• - in a second operating mode, a charging mode, the first coolant circulates through the drive motor and the heat accumulator, whereby the first coolant absorbs the waste heat of the drive motor and releases it to the heat accumulator for storage,

and which is characterized by

• - in a third operating mode, a battery heating mode, the first coolant circulates only through the heat accumulator and the battery designed as a traction battery of an electric or hybrid vehicle, wherein the first coolant absorbs heat stored in the heat accumulator and releases it to the battery in order to preheat it.

The invention is therefore also directed to a method for operating a heat storage arrangement for using engine waste heat to preheat a battery. This is a traction battery of an electric or hybrid motor vehicle. The heat storage arrangement has a first cooling circuit and a second cooling circuit according to the embodiments described above. The first cooling circuit has at least one drive motor, a heat storage device, a first cooler and a first coolant. The first coolant circulates in the first cooling circuit. The second cooling circuit has at least one battery, a second cooler and a second coolant, wherein the second coolant is preferably identical to the first coolant and circulates in the second cooling circuit. The cooling circuits can also have further components, such as pumps for conveying the coolants, valves, temperature sensors and the like. As stated above, the heat storage arrangement can be operated in at least three different operating modes. In the first operating mode, which is a standard mode, the first coolant circulates through the drive motor and the first cooler. The standard mode serves purely to dissipate the waste heat generated in the drive motor. To do this, the first coolant passes through the drive engine and absorbs the waste heat that is generated during engine operation. The first coolant then passes through the first radiator, allowing the waste heat contained in the coolant to be released into the outside environment of the vehicle.

The second operating mode, a so-called charging mode, is used to charge the heat storage unit with thermal energy. To do this, the first coolant runs through the drive motor and absorbs the waste heat generated during engine operation. The coolant is then fed to the heat storage unit in order to release the absorbed waste heat to it. To do this, the heat storage unit can either be fed with the hot coolant or the waste heat contained in the coolant is transferred to a separate heat storage medium in the heat storage unit using suitable means.

As already mentioned above, the heat storage arrangement has the third operating mode, a battery heating mode, for preheating the battery. In this operating mode, the first coolant only circulates through the heat storage and the battery. The drive motor is not passed through. The first coolant absorbs the waste heat stored in the heat storage by either removing the coolant contained therein from the heat storage or transferring the heat contained in the heat storage medium to the coolant. The first coolant is then removed from the first cooling circuit and fed into the second cooling circuit to pass through the battery. The heat contained in the first coolant is given off to the battery, which can be preheated, for example to carry out a cold start. After the first coolant has passed through the battery, this or a mixture of the first and second coolants is fed back into the first cooling circuit and the heat storage integrated there. Advantageously, it is not necessary to start or operate the drive motor to preheat the battery. Due to the fluidic coupling between the first and the second cooling circuit, complex components for thermal coupling, such as heat exchangers, can be avoided.

As already mentioned above, the first cooling circuit has an additional heat exchanger. In a fourth operating mode, an interior heating mode, the first coolant can The heat exchanger passes through the drive motor to release the waste heat absorbed by the drive motor. In particular, the waste heat can be used to heat the vehicle interior. The heat storage unit can be switched between the drive motor and the heat exchanger using a three-way valve.

Alternatively, according to a fifth operating mode, a storage heat heating mode, the first coolant can only be circulated through the heat accumulator and the heat exchanger. The drive motor is not passed through in this case. The first coolant takes the stored heat from the heat accumulator and transfers it to the heat exchanger, in particular for heating the vehicle interior. After passing through the heat exchanger, the first coolant flows back to or into the heat accumulator. A process variant that combines the third operating mode with the fifth operating mode is particularly advantageous. The first coolant first flows through the heat accumulator, absorbs the heat stored therein and then passes through the heat exchanger. In this case, part of the heat contained in the first coolant can be transferred to the heat exchanger and used, for example, to heat the vehicle interior. After passing through the heat exchanger, the first coolant is fed into the second cooling circuit and then passes through the battery. The residual heat contained in the coolant can be used to preheat the battery. The first coolant or a mixture of the first and second coolants is then fed back into the first cooling circuit. In this way, both the passenger compartment and the battery of a motor vehicle, in particular an electric or hybrid vehicle, can be preheated or heated to operating temperature before a cold start.

• 1 zeigt ein schematisches Verfahrensfließbild einer Wärmespeicheranordnung mit einem ersten und einem zweiten Kühlkreislauf, wie sie aus dem Stand der Technik bekannt ist. Weitere vorteilhafte Ausgestaltungen der Erfindung sind in den Unteransprüchen und der folgenden Figurenbeschreibung offenbart. Es zeigen:
• 2 ein schematisches Verfahrensfließbild einer Wärmespeicheranordnung mit einem ersten und einem zweiten Kühlkreislauf, in einem ersten Betriebsmodus.
• 3 ein schematisches Verfahrensfließbild der Wärmespeicheranordnung aus 2 in einem zweiten Betriebsmodus,
• 4 ein schematisches Verfahrensfließbild einer Wärmespeicheranordnung aus 2 in einem dritten Betriebsmodus,
• 5 ein schematisches Verfahrensfließbild einer Wärmespeicheranordnung aus 2 in einem ersten Betriebsmodus mit zugeschaltetem Wärmespeicherheizmodus.

An optional embodiment of the method allows a heat storage heating mode to be activated, whereby a heat storage medium contained in the heat storage device can be heated using an external energy supply. For this purpose, the heat storage device has an electrical heating medium, for example in the form of an immersion heater, which can be operated either by the vehicle battery or by means of an external energy supply, for example a power connection. In this way, the heat storage medium of the heat storage device can be charged with sufficient heat energy even after any length of downtime or non-operation of the drive motor in order to preheat the interior and/or the battery of the vehicle during the next cold start.

• 1 shows a schematic process flow diagram of a heat storage arrangement with a first and a second cooling circuit, as is known from the prior art. Further advantageous embodiments of the invention are disclosed in the subclaims and the following description of the figures. They show:
• 2 a schematic process flow diagram of a heat storage arrangement with a first and a second cooling circuit, in a first operating mode.
• 3 a schematic process flow diagram of the heat storage arrangement from 2 in a second operating mode,
• 4 a schematic process flow diagram of a heat storage arrangement from 2 in a third operating mode,
• 5 a schematic process flow diagram of a heat storage arrangement from 2 in a first operating mode with heat storage heating mode activated.

In the different figures, identical parts are always provided with the same reference symbols, which is why they are usually only described once.

In 1 is a schematic process flow diagram of a heat storage arrangement 100 according to the prior art. The heat storage arrangement 100 has a first cooling circuit 200 and a second cooling circuit 300. The first cooling circuit 200 is designed as a high-temperature cooling circuit for cooling a drive motor 210, preferably an internal combustion engine, and also has a cooler 220, a heat storage device 230 and a heat exchanger 240. A thermostat 211 for regulating the temperature of a first coolant which circulates in the first cooling circuit 200 is connected to the drive motor 210. The flow direction of the first coolant is shown by the arrows in the flow diagram. A first line section 212, a second line section 213 and a third line section 214 are connected to the thermostat 211. The first line section 212 opens into a first three-way valve 231. The heat accumulator 230 can be connected to the first cooling circuit 200 by means of the three-way valve 231. A first pump 232, preferably an electric water pump, is connected upstream of the heat accumulator 230 in terms of the flow direction. The heat accumulator 230 is implemented in this embodiment as an insulated container for the hot coolant. According to the illustrated circuit of the three-way valve 231, the first coolant flows directly into the heat exchanger 240 without first passing through the heat accumulator 230. A second pump 215, which is connected upstream of the drive motor 210, the first coolant is fed back to the drive motor 210.

The first coolant is fed to the first cooler 220 by means of the second line section 213. The first cooler 220 serves to release the heat contained in the coolant to the environment. After passing through the cooler 220, the first coolant is in turn fed back to the drive motor 210 via the second pump 215. The third line section 214 can be used to feed the first coolant, if it has not yet absorbed sufficient heat, directly back to the combustion engine 210 via the second pump 215. The thermostat 211 is used to control the first coolant. Depending on the desired operating mode or measured coolant temperature, the corresponding line sections 212, 213 or 214 are opened or closed. The second cooling circuit 300 is designed as a low-temperature cooling circuit for cooling a battery 310, preferably a traction battery of a hybrid vehicle. In addition to the battery 310, the second cooling circuit 300 has a second cooler 320, which is designed as a low-temperature cooler, and a third pump 340, preferably an electric water pump. A second coolant circulates within the second cooling circuit 300, with the arrows in the flow diagram showing the flow direction of the second coolant. The second coolant absorbs the heat emitted by the battery 310 and passes through the second cooler 320 in order to release the absorbed heat to the environment. In the prior art, it is known to design the first cooler 220 and the second cooler 320, for example, as a direct current heat exchanger in order to create a thermal coupling between the first cooling circuit 200 and the second cooling circuit 300.

In the following, the terms “in front of” and “behind” refer to the flow direction of the coolant in question, as indicated by the arrows.

A schematic process flow diagram of a heat storage arrangement 100 is shown in 2 The heat storage arrangement 100 essentially corresponds to the heat storage arrangement known from the prior art according to 1 , wherein the first cooler 220 and the second cooler 320 preferably have no thermal coupling. The first cooling circuit 200 additionally has a first connecting line 410, which opens into a second three-way valve 330. The second three-way valve 330 is integrated into the second cooling circuit 300 immediately before the battery 310. If the second three-way valve 330 is in the appropriate position, the first coolant from the first cooling circuit 200 can be fed into the second cooling circuit 300. A second connecting line 420 is fluidically connected to the second cooling circuit 300 immediately behind the battery 310 for removing the first coolant and/or a mixture of first and second coolant. The second connecting line 420 opens into the first cooling circuit 200 immediately before the first pump 232.

According to 2 a first operating mode, a standard mode, is shown. The first coolant circulates through the drive motor 210, absorbs its waste heat, passes through the thermostat 211, the second line section 213 and the first cooler 220 in order to release the heat contained in the coolant to the environment. The first coolant is then conveyed back to the drive motor 210 by means of the second pump 215. Alternatively, the first coolant can be fed to the first three-way valve 231 by means of the first line section 212. According to the position of the three-way valve 231 shown, the first coolant is then fed directly to the heat exchanger 240 and conveyed to the drive motor 210 by means of the second pump 215.

In 3 is a schematic process flow diagram of a heat storage arrangement 100 according to 2 shown. In this second operating mode, the first coolant, provided it has absorbed sufficient waste heat from the drive motor 210, is fed to the first line section 212 by means of the thermostat 211. The first three-way valve 231 is in the appropriate position to switch on the heat accumulator 230. The first coolant is fed to the heat accumulator 230 by means of the second pump 215 in order to charge it with the absorbed waste heat. It can also be useful for both pumps 232 and 215 to be activated simultaneously in order to increase the coolant flow to the heat accumulator 230. The first coolant then runs through the heat exchanger 240 in order to release any remaining heat to the vehicle interior. The cooled coolant is pumped back to the drive motor 210 by means of the second pump 215.

A third operating mode, a battery heating mode, is available in 4 The schematic process flow diagram shows a heat storage arrangement 100 according to 2 . To preheat the battery 310, the second three-way valve 330 is in the appropriate position to fluidically connect the first connecting line 410 to the second cooling circuit 300. The first coolant is pumped from the heat accumulator 230 by means of the first pump 232, passes through the heat exchanger 240 and is then fed into the second cooling circuit 300 via the connecting line 410. The first coolant then passes through the battery 310 and transfers the heat contained in the first coolant to it. By means of the connecting line 420, which connects to the second cooling circuit 300 immediately after the battery 310, the first coolant and/or a mixture of first and second coolant is fed back into the first cooling circuit 200 immediately before the first pump 232. The coolant circulates through the heat accumulator 230 and the battery 310 until, for example, a temperature sensor registers that the battery 310 has reached its operating temperature. Alternatively or optionally, part of the heat contained in the first coolant can be used to heat the vehicle interior by means of the heat exchanger 240. It is also conceivable to bypass the heat exchanger 240 by means of a bypass (not shown).

In 5 There is a heat storage arrangement 100, according to 2 , in a first operating mode. In addition, an optional heat storage heating mode is activated, in which an electrical heating element 500 is used to charge the heat storage 230 with external energy. The electrical heating element 500 can be, for example, a simple immersion heater that is supplied with electrical energy by means of the battery 310, another vehicle battery or an external power source. In particular, after a longer period of downtime of the motor vehicle, for example after several days, the heat storage 230 can be charged in this way by external energy supply and the stored energy in the form of heat can be used to preheat the battery 310 according to the third operating mode.

List of reference symbols:

100

heat storage arrangement

200

first cooling circuit / high-temperature cooling circuit

210

drive motor

211

thermostat

212

first line section

213

second line section

214

third line section

215

second pump

220

first cooler / high-temperature cooler

230

heat storage

231

first three-way valve

232

first pump

240

heat exchanger

300

second cooling circuit / low-temperature cooling circuit

310

battery

320

second cooler / low-temperature cooler

330

second three-way valve

340

third pump

410

first connecting line

420

second connecting line

500

electric heating element

Claims (7)

Heat storage arrangement (100) designed to use engine waste heat to preheat a battery (310) designed as a traction battery of an electric or hybrid motor vehicle, with a first cooling circuit (200) which has at least - a drive motor (210) designed as an internal combustion engine and generating waste heat, wherein the waste heat is dissipated by means of a first coolant, - a heat storage device (230) designed to store the waste heat contained in the first coolant, - a heat exchanger (240) designed to use the waste heat contained in the first coolant, wherein the heat exchanger (240) is integrated into the first cooling circuit (200) by means of a first three-way valve (231), - a first cooler (220) for releasing the waste heat contained in the first coolant to the environment, and with a second cooling circuit (300) which has at least - a battery (310) designed as a traction battery of an electric or hybrid motor vehicle, designed to store electrical energy for feeding an electric motor, wherein the battery (310) is cooled by means of a second coolant, - a second cooler (320) designed to release heat contained in the second coolant to the environment, characterized in that the first cooling circuit (200) is fluidically coupled to the second cooling circuit (300) by means of a first and a second connecting line (410,420), wherein the first cooling circuit (200) has a first connecting line (410) arranged downstream of the heat exchanger (240), which opens into a second three-way valve (330) which is integrated into the second cooling circuit (300) immediately upstream of the battery (310), wherein a second connecting line (420) for removing the first coolant and/or a mixture of first and second coolant is directly connected to the second cooling circuit (300). telbar behind the battery (310) is fluidically connected to the second cooling circuit (300), wherein the second connecting line (420) opens into the first cooling circuit (200) immediately before the first pump (232), wherein the waste heat stored in the heat accumulator (230) can be used by means of the first coolant to preheat the battery (310) designed as a traction battery of an electric or hybrid motor vehicle. Heat storage arrangement (100) according to claim 1 , characterized in that the heat accumulator (230) has an electrical heating means (500) which is designed to release heat to a heat storage medium contained in the heat accumulator (230). Heat storage arrangement (100) according to claim 1 or 2 , characterized in that the heat exchanger (240) is designed to use the waste heat contained in the first coolant for heating the vehicle interior. Method for operating a heat storage arrangement (100) for using engine waste heat to preheat a battery (310) designed as a traction battery of an electric or hybrid motor vehicle according to one of the preceding claims, with a first cooling circuit (200) which has at least one drive motor (210) designed as an internal combustion engine, a heat accumulator (230), a first cooler (220), a heat exchanger (240) and a first coolant which circulates in the first cooling circuit (200), a second cooling circuit (300) which has at least one battery (310) designed as a traction battery of an electric or hybrid motor vehicle, a second cooler (320) and a second coolant which circulates in the second cooling circuit (300), and with at least three operating modes, wherein in - in a first operating mode, a standard mode, the first coolant circulates through the drive motor (210) and the first cooler (220), wherein the first coolant contains waste heat from the drive motor (210) and releases it to the environment via the first cooler (220), - in a second operating mode, a charging mode, the first coolant circulates through the drive motor (210) and the heat accumulator (230), wherein the first coolant absorbs the waste heat of the drive motor (210) and releases it to the heat accumulator (230) for storage, characterized in that - in a third operating mode, a battery heating mode, the first coolant circulates only through the heat accumulator (230) and the battery (310) designed as a traction battery of an electric or hybrid vehicle, wherein the first coolant absorbs heat stored in the heat accumulator (230) and releases it to the battery (310) in order to preheat it. procedure according to claim 4 , characterized in that in a fourth operating mode, an interior heating mode, the first coolant circulates through the drive motor (210) and the heat exchanger (240), wherein the first coolant absorbs the waste heat of the drive motor (210) and releases it to the heat exchanger (240), in particular for heating a vehicle interior. Method according to one of the Claims 4 or 5 , characterized in that in a fifth operating mode, a storage heat heating mode, the first coolant circulates only through the heat accumulator (230) and the heat exchanger (240), wherein the first coolant absorbs heat stored in the heat accumulator (230) and releases it to the heat exchanger (240), in particular for heating a vehicle interior. Method according to one of the Claims 4 until 6 , characterized in that a heat storage heating mode can be switched on in order to supply heat to a heat storage medium contained in the heat accumulator (230) by means of an electrical heating means (500).

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