DE102016104293A1 - Vehicle exhaust gas purification device, device with a vehicle exhaust gas purification device and method for operating a device - Google Patents

Abstract

A vehicle exhaust gas purification device (10) comprises an exhaust gas-carrying cleaning body (4.1), a heat from the cleaning body (4.1) heatable in operation heat storage device (4.5), which is adapted to receive and store a first heat flow (14), and at least one thermoelectric module, which is arranged for the conversion of thermal energy into electrical energy and is heat-transfer coupled to the heat storage device (4.5). Furthermore, a device (4) with a vehicle exhaust gas purification device (10) and a method for operating such a device (4) are provided.

Description

The invention relates to a vehicle exhaust gas purification device, a device with a vehicle exhaust gas purification device for converting waste heat into electrical energy in a motor vehicle and a method for operating such a device.

The conversion of waste heat from internal combustion engines into electrical energy in a motor vehicle is known. With this electrical energy, for example, electrical devices can be operated or charged batteries, which energy efficiency can be increased. In the prior art so-called thermoelectric generators (TEG) are already described, which convert thermal energy into electrical energy and can be used in exhaust systems.

Such a device for converting waste heat into electrical energy by means of TEG is for example in the DE 11 2010 003 759 T5 disclosed. Furthermore, the general structure and the general mode of operation of TEG are already sufficiently known from this publication and numerous other publications in the prior art, so that will not be discussed further here.

The integration of such thermoelectric systems in the exhaust gas system serving as a heat source and the adequate cooling of these is often expensive. The additional components required, such as lines, control valves, valves, TEG, etc., not only increase the cost, but also the weight. Furthermore, there are operating states during the drive of a motor vehicle, during which no or only a small amount of energy from the TEG in the electrical system of the motor vehicle is traceable, for example, during a braking operation in a hybrid vehicle often so much energy is recovered that the electrical energy from the TEG in this case remains unused. Furthermore, due to the relatively large thermal engine loss rates of 50% or more, large thermal power is often a concern. To make this high performance directly usable, therefore, an equally powerful TEG with many thermoelectric modules is necessary, which usually has a high weight. Depending on the arrangement of the TEG in the exhaust system, this can also cause an undesirable increase in the exhaust backpressure.

The object of the invention is to provide a compact device for integrating TEGs, a device for converting waste heat into electrical energy in a motor vehicle, which offers greater energy efficiency and additionally saves costs and weight, and to provide a method for operating such a device.

To achieve the object, a vehicle exhaust gas purification device is provided with an exhaust gas-carrying cleaning body, a heated by the cleaning body in operation heat storage device, which is adapted to receive and store a first heat flow, and at least one thermoelectric module, which is adapted to convert thermal energy into electrical energy is and is coupled heat-transmitting to the heat storage device. By the heat storage device is integrated in an existing in the motor vehicle exhaust gas-carrying cleaning body and the thermoelectric module is coupled to this heat storage device, can be dispensed with an additional, provided for the conversion of waste heat into electrical energy device in the exhaust system. In particular, the cleaning body at the same time takes over the cleaning and heat transfer function. This functional integration has the advantage that the elimination of an additional device weight and cost can be saved and the unused space can be used for example for a middle silencer. Furthermore, the arrangement of the set up for the conversion of thermal energy into electrical energy elements in the exhaust gas purification device does not increase the exhaust gas back pressure by additional heat-transmitting structures in the exhaust system, since none of these elements are additionally arranged on the exhaust pipe.

The heat source heats up the heat storage part and this gives off its heat to the thermoelectric module in a time-delayed manner so that fewer thermoelectric modules are needed than without a heat storage part, because without a heat storage part, the conversion process would be limited to those states in which the engine is running and heat can be extracted from the exhaust gas. For a similarly high energy yield then significantly more expensive thermoelectric modules would have to be used.

For the purposes of the invention, a heat storage device is to be understood as a device which is set up for the storage of thermal energy. Preferably, this heat storage device for storing heat energy from an exhaust gas stream of the exhaust system of the motor vehicle is set up.

For charging the heat storage device of this is a first heat flow from the exhaust gas stream supplied, in particular by a volume flow (convection), by contacting ( Heat conduction) or by heat radiation. Preferably, the first heat flow via contacting can be represented by the heat storage device directly a guide device, in particular the cleaning body, in which this exhaust gas stream is guided, contacted. In particular, by the transmission of the first heat flow by means of contacting it is possible to achieve a particularly efficient transmission.

The heat storage device is in particular a separate from the cleaning body, prefabricated part. Alternatively, the heat storage device may be configured in one piece with the cleaning body or the heat storage device may be formed by the radially outer layer of the cleaning body. In this case, the heat transfer within the element is particularly advantageous, and the manufacture and assembly can be simplified.

Preferably, the exhaust gas purification device is a catalyst or a particulate filter, with a housing, in which the cleaning body is positioned over a bearing mat, which is arranged between the housing and the cleaning body. Here, the storage mat also serves for storage of the heat storage device with the cleaning body and for thermal insulation of the heat storage device. As a result, the energy efficiency of the motor vehicle can be further increased. For example, the additional heat that arises in exothermic reactions in the catalyst, also be used, creating a higher usable heat and thus energy is available. Furthermore, only a single housing is required, which surrounds the device.

According to a preferred embodiment, the heat storage device is arranged radially between the bearing mat and the cleaning body and surrounds the cleaning body in particular circumferentially. Preferably, the heat storage device is designed as a ring body. This arrangement ensures that a large part of the heat generated can be absorbed and stored. Another advantage that results from this is that the cleaning body cools more slowly and thus can have a higher efficiency over a longer period of time. For example, for a catalyst, higher temperatures result in lower emissions. In addition, the thermal operating safety of surrounding components is improved by the increased heat capacity of the cleaning body, since less heat is given to this. As a result, the heat protection measures can be reduced in this area by, for example, partially or completely dispensed with heat shields. This leads to a further reduction of costs and weight.

According to a further preferred embodiment, the bearing mat has at least one recess which, on the outer surface of the heat storage device, releases a first transfer region for a second heat flow from the heat storage device to the thermoelectric module. In this way, a particularly favorable heat transfer to the thermoelectric module and thus a particularly high energy efficiency can be ensured.

Preferably, the heat storage device is at least partially or entirely of a material selected from the group consisting of metal, ceramic, thermal oil, thermal oil, phase change material, such as, in particular, salt or metal with high heat of fusion. The materials mentioned are characterized by a high specific heat capacity and a high thermal conductivity. In addition, they have at least in part a high density.

For the purposes of the invention, "phase change material" is understood to mean materials whose latent heat of fusion, solution heat or heat of absorption is substantially greater than the heat which they can store (without the phase transformation effect) due to their specific heat capacity. Such materials are known from the prior art.

The abovementioned materials, but especially metals, with a large heat of fusion have a heat of fusion of preferably greater than 100 kJ / kg, preferably greater than 200 kJ / kg and particularly preferably greater than 300 kJ / kg. Further preferably, such metals are materials which comprise, as part of aluminum, preferably tin and particularly preferably zinc, or at least partially consist thereof.

Preferably, a metal is understood to mean a steel material, in particular a stainless steel material. Further preferably, the material for the heat storage device as a component of at least one of the following constituents or consists of these: aluminum, copper, nickel or brass.

Preferably, a ceramic material is to be understood as meaning aluminum nitride, silicon carbide or aluminum oxide. Alumina is particularly preferably formed as Al ₂ O ₃ .

In particular, the materials from the group of metals have a high specific heat storage capacity. Ceramic materials also have a high specific heat storage capacity.

The heat storage device is in particular a sensitive or sensitive heat storage device, ie there is no phase transition in the heat storage device in the operating temperature range. The heat storage device consequently consists of a solid.

According to an advantageous embodiment, the heat storage device has on the outer circumference a the thermoelectric module facing extension, which is designed as a separate part or integrally formed on it. This extension can protrude through the recess in the bearing mat, for example, and thus allows the thermoelectric module to be arranged outside the bearing mat. Furthermore, the volume and thus the heat storage capacity of the heat storage device are advantageously extended by this extension.

According to a further advantageous embodiment, the extension has a flat outer side, to which the thermoelectric module is coupled heat-transmitting, in particular wherein it rests against it. This design ensures a particularly high potential heat transfer performance.

The heat storage device and / or the extension preferably consists of a ceramic material with a decreasing thermal conductivity as the temperature increases, in particular of an aluminum ceramic. By virtue of this property, the heat storage device and / or the extension has a self-locking function which controls the second heat flow and thus can prevent, in particular, overheating of the thermoelectric module.

To solve the problem, a device for converting waste heat into electrical energy in a motor vehicle, provided with a vehicle exhaust gas purification device according to the invention, with a heat source, in particular in the form of an internal combustion engine, a generated from this heat source main heat flow, in particular in the form of an exhaust gas stream, which is in flow communication with the cleaning body, wherein the second heat flow from the heat storage device, in particular via the first transfer area, is deliverable to the thermoelectric module, and a heat control device which is adapted to control one of the heat flows, wherein the heat control device, the second heat flow interruptible is.

For the purposes of the invention, a heat source is understood in particular to mean an internal combustion engine. Preferably, this internal combustion engine is a thermal combustion engine with internal combustion, in particular a combustion engine in reciprocating design, which operates, for example, according to the diesel or Otto principle.

In such internal combustion engines falls by the conversion of energy, which is present in the fuel in chemically bound form, in mechanical energy, an exhaust gas stream. This exhaust stream usually contains a certain amount of residual energy. In particular, by thermoelectric modules, which are adapted to convert thermal energy into electrical energy, at least a portion of the amount of energy contained in this exhaust stream can be made available for further use.

For the purposes of the invention, a second heat flow means an energy flow which is directed from the heat storage device to the thermoelectric module. Preferably, this second heat flow, as well as the first heat flow, by a volume flow (convection), by contacting (heat conduction) or by heat radiation transferable.

By virtue of the fact that the second heat flow can be interrupted by the heat control device, it is possible, for example, to charge the heat storage device during a travel time or during a driving cycle of the vehicle and to discharge it during the subsequent vehicle standstill through the thermoelectric module.

It is likewise possible to supply a relatively small heat flow from the heat storage device to the thermoelectric module even while driving. For the purposes of the invention, a relatively low heat flow means a heat flow which is less than the maximum heat flow that can be supplied to the heat storage device. Preferably, this second heat flow is less than 75% of the first heat flow, more preferably less than 50% and most preferably less than 25%. By such a division, it is on the one hand possible to use a relatively small thermoelectric module, and on the other hand, a large heat potential can be used by the heat storage device.

Here is a basic idea of the invention, the use (conversion into electrical energy) of the waste heat provided during the vehicle cycle, which can be stored in the heat storage device, to decouple from the storage of these temporally. By this decoupling, it is possible in particular to use a thermoelectric module with a lower power, which during a compared with a time for storing, longer time phase, the heat from the heat storage device converts, as if the thermoelectric module is designed to convert the heat immediately and as completely as possible. Studies have shown that both a weight and a cost advantage over known systems can be achieved by a thermoelectric module and a heat storage device configured in the aforementioned manner. Another advantage is that can be set by a lower second heat flow, a small third heat flow, in the form of waste heat of the electric heat module. Such a lower third heat flow is then dissipated by means of passive cooling and it is therefore in particular no active cooling from a vehicle cooling system necessary.

In this discharge of the heat storage device electrical energy is provided for the electrical system available and it is made possible by the special configuration of the invention that this in the electrical system, in particular in the electrical energy storage device, is receivable. Further preferably, the heat storage device can be controlled as needed. The demand-driven activation is preferably to be understood as meaning that the heat in the heat storage device can be utilized by the thermoelectric module if electrical energy can be absorbed in the electrical system, ie if in particular the electrical energy storage device has a charge state below a predetermined limit value.

According to one embodiment, the second heat flow is transferable by heat conduction, in particular substantially without convection, and the heat storage device for transmitting the second heat flow is contacted directly or indirectly by the thermoelectric module. This ensures optimal heat conduction and thus energy efficiency.

Preferably, the device is designed such that in a first operating mode, the heat storage device receives the first heat flow from the exhaust gas flow and no second heat flow, and in a second operating mode, the heat storage device emits the second heat flow to the thermoelectric module and receives no first heat flow.

In a preferred embodiment, during a second mode of operation, the heat flow between the heat storage device and the thermoelectric module is interrupted, and the first heat flow is transferable between the exhaust gas flow and the heat storage device.

Further preferably, this first operating mode is characterized in that the internal combustion engine runs in the fired operation or that the motor vehicle is in driving operation.

In a second mode of operation, the second heat flow is transferred from the heat storage device towards the thermoelectric module, and further the heat storage device in this second mode of operation receives substantially no first heat flow from this exhaust gas flow. This second operating mode is characterized for example by the vehicle standstill or by the fact that the internal combustion engine is stationary.

In one embodiment, the second heat flow by heat conduction, in particular by an indirect or direct contacting of the thermoelectric module with the heat storage device, in particular at the first transfer area, transferable. By direct contacting, it can be understood, for example, that a contacting region is provided on the thermoelectric module and on the heat storage device, in which they contact or touch each other for heat transfer. Furthermore, indirect indirect contacting of the thermoelectric module with the heat storage device is to be understood as meaning that at least one or more transmission components for transmitting the second heat flow can be brought between these two.

By a direct transfer of the second heat flow, a particularly efficient transmission of this heat flow is possible. Furthermore, a particularly secure separation of the heat transfer between the thermoelectric module and the heat storage device can take place by an indirect transfer of the second heat flow.

For indirect transmission of the second heat flow, for example, a transmission component is provided, which is movable, in particular via a switchable actuator (drive), which can be moved between two positions, wherein in a first position, the thermoelectric module is in contact with the heat storage device and in a second position through an air gap separated from the heat storage device. As a result, the second heat flow can be interrupted.

Preferably, an electric, preferably a hydraulic and particularly preferably a pneumatic actuator is provided for moving the thermoelectric module. Pneumatic actuators, such as a vacuum box, are often used in motor vehicles and have high reliability. In particular, by means of a hydraulic actuator, a particularly secure pressing of the thermoelectric module can be achieved on the heat storage device, and thus the transmission of the second heat flow can be improved. In particular by means of an electrical actuating device, a particularly precise controllable pressing of the thermoelectric module on the heat storage device is made possible.

In a variant, the thermoelectric module has at least one second transfer area for discharging a third heat flow. Preferably, this second transfer area is set up for discharging a heat quantity. In particular, the fact that not the complete, the thermoelectric module can be supplied heat output into electrical energy is convertible, this residual heat can be discharged to the environment usually by the thermoelectric module. By means of this second transfer region, this third heat flow can be selectively released.

In a further embodiment, the thermoelectric module is arranged on the opposite side of the heat storage device to the cleaning body, and the second transfer region is arranged on a heat storage device opposite side of the thermoelectric module and protrudes in particular out of the housing. This arrangement ensures the supply of heat on one side of the thermoelectric module and the heat removal on the other side of the thermoelectric module and thus a high temperature gradient, which is required for an efficient conversion of waste heat into electrical energy by the thermoelectric module.

This second transfer region can have a heat sink or is designed as a heat sink with at least one or preferably a plurality of cooling ribs. In this case, these cooling fins are aligned such that sets a natural or free convection due to the deliverable third heat flow. Preferably, the orientation of the cooling fins is vertical.

Optionally, this second transfer region can be flowed by a convection volume flow, wherein this convection volume flow can be generated by a fan device. Preferably, a flow direction of this convection volume flow is oriented in the direction of the extent of the cooling ribs. In particular, by such an orientation of the convection volume flow and the cooling fins a particularly good heat transfer can be achieved.

In a preferred embodiment, this convection volume flow, for example after it has left the second transfer area, can be supplied to a heat sink in the motor vehicle or can be removed from the motor vehicle. For the purposes of this invention is to be understood by heat reduction in the motor vehicle in particular a lubricant reservoir. Such lubricant reservoirs are formed in particular in the engine oil pan or in a transmission housing. In particular, by supplying this convection volume flow to these heat sinks in the motor vehicle, a preheating of lubricant or the slowing down of the cooling of the lubricant is made possible, and thus a further increase in efficiency can be achieved. The targeted removal of the convection volume flow from the vehicle, an improved thermal management of the motor vehicle is possible.

The invention further provides a method for operating a device according to the invention, in which a first heat flow is supplied during a first operating phase of the heat storage device. At the same time or after this first phase, a second heat flow is removed from this heat storage device and fed to the thermoelectric module. Furthermore, in this second phase, at least one of the thermoelectric modules dissipates a third heat flow. In particular, by controlling the heat flows in this manner, it is possible to charge the heat storage device with heat energy in a first phase and during a second phase, in particular a stoppage phase of the motor vehicle to discharge this heat storage and the electrical energy thereby converted particularly efficient to store an electrical energy storage device of the motor vehicle.

In a preferred embodiment, this second heat flow is the thermoelectric module in the vehicle standstill, especially when the vehicle speed is preferably equal to zero for a limited time, fed.

Furthermore, a vehicle standstill may be subject to further criteria that go beyond detection of the vehicle speed. As a result, short-term holding phases, such as in particular a traffic light stop, can not be considered a vehicle standstill. Preferably, a narrow time is understood to mean a period of 1 s or more, preferably 60 s or more, and more preferably 300 s or more. Next is to be understood by additional criteria in particular a recognition, whether a so-called Ignition key or a keycard to start the vehicle is located in this.

Further preferably, the state of charge of the electrical energy storage device is taken into account to decide whether the thermoelectric module, a second heat flow can be supplied. Preferably, a second heat flow can be fed to the thermoelectric module only if the state of charge of the electrical energy storage device, which electrical energy can be supplied from the thermoelectric module, has a charge state below a predeterminable limit value. Preferably, this limit value for the state of charge is 95%, preferably 85% and particularly preferably 75%. Such a limit can enable efficient storage of energy in the electrical energy storage device.

In a preferred embodiment, the second heat flow is supplied to the thermoelectric module only until the heat storage device reaches or falls below a predeterminable energy content. Preferably, to determine this energy content in the heat storage device, a temperature, at least a portion of this device is used.

Further preferably, this energy content (limit value) up to which the heat storage device is discharged depends on the ambient temperature.

Further advantages and features will become apparent from the following description taken in conjunction with the accompanying drawings. In these show:

1 a longitudinal section through a motor vehicle with a device according to the invention,

2 an operating scheme for the operation of a device according to the invention,

3 a perspective view of a device according to the invention with a vehicle exhaust gas purification device according to the invention,

4 a side view of the device 3 .

5 a sectional view of the device 3 .

6 a plan view of the device 3 .

7 another sectional view of the device 3 , and

8th a sectional view of another embodiment of the vehicle exhaust gas purification device according to the invention with an extension.

In the in 1 illustrated sectional view of the motor vehicle 1 is the device according to the invention 4 shown. In this case, the device 4 from the internal combustion engine 2 the exhaust gas flow 3 fed. The exhaust gas flow 3 is before entering the device 4 at the point 3a higher in energy than after exiting the device 4 at the point 3b ,

The device according to the invention has a gas-carrying cleaning body 4.1 which is adapted to the exhaust gas flow 3 remove as much thermal energy and the heat storage device 4.5 supply. In this case, the heat storage device 4.5 by the first heat flow (not shown) from the cleaning body 4.1 Energy supplied. In vehicle standstill mode and when the heat storage device 4.5 can be charged to the thermoelectric module 4.3 the second heat flow (not shown) are supplied. The thermoelectric module 4.3 converts the thermal energy supplied to it into electrical energy. The electrical energy is in an energy storage device 6 stored.

In this case, this energy storage device 6 be designed as a traction or starter energy storage. For removing a third heat flow in the form of a convection volume flow 4.7 via an exhaust air heat pipe 4.6 has the device 4 a second transfer area 4.4 with several cooling fins on. To increase the efficiency, the device 4 a storage mat 4.2 which, inter alia, serves as a thermal insulation layer and in this way reduces unwanted heat flows.

In the 2 is the course of the vehicle _speed V _FZG , the temperature of the heat storage device T _WS , the recovered by the thermoelectric module electrical power P _EL and the cumulative amount of energy E _KUM each shown as a course over time t.

During a first phase P _I is the device according to the invention 4 in a first mode of operation 4.a in which the thermoelectric module 4.3 the heat storage device 4.5 not contacted. The energy storage device 6 is at the beginning of the first phase P _I in state 6.a ie fully charged. More energy would thus not be stored in this. In the first phase P _I , the vehicle moves at the speed V _FZG . The temperature of the heat storage device T _{WS increases} by supplying a Heat flow from the exhaust stream 3 to this heat storage device 4.5 at.

If a vehicle standstill is detected, in particular if the vehicle _speed V _FZG is 0 for a long time (vehicle standstill), the device according to the invention becomes 4 in the second operating mode 4.b and thus initiated the second phase P _II .

This is the thermoelectric module 4.3 with the heat storage device 4.5 brought into contact. The heat is removed from the heat storage device 4.5 particularly efficiently transferred without particle transport or convection. As a result of this contacting, the second heat flow (not shown) is formed and the thermoelectric module 4.3 converts the thermal energy from the heat storage device 4.5 into electrical energy, which is the energy storage device 6 can be fed. Accordingly falls in this second phase P _II, the temperature of the heat storage device 4.5 down to a lower limit, this corresponds to a specific energy content.

With decreasing temperature T _{WS of} the heat storage device 4.5 also falls from the thermoelectric module 4.3 Deliverable electrical power P _EL continuously. The storage state of the energy storage device 6 before the start of the second phase P _II from the state 6.b on the state 6.c increased to the end of the second phase P _II . As long as the thermoelectric module 4.3 an electric power P _{EL is} deliverable, the cumulative energy E _KUM increases. After the end of the second phase P _II , a first phase P _{I can be} introduced again, to which is the thermoelectric module 4.3 from the heat storage device 4.5 removed and the heat storage device 4.5 can be recharged with heat during vehicle operation.

The method can also be applied to an incomplete, ie partially charged, energy storage device 6 be used.

The method may also be during operation of the motor vehicle 1 be used.

The converted energy can be used both to charge the energy storage device 6 used as well as wholly or partly in the electrical system of the motor vehicle 1 be fed.

The second heat flow becomes the thermoelectric module 4.3 preferably supplied only until an energy content or a temperature of the heat storage device 4.5 reaches or falls below a predetermined limit.

In the 3 is the device 4 for converting waste heat into electrical energy in a motor vehicle having a vehicle exhaust gas purification device according to the invention 10 shown in a perspective view.

The exhaust gas purification device 10 may be a catalyst or a particulate filter.

The exhaust gas purification device 10 comprises a cylindrical, exhaust gas-carrying cleaning body 4.1 in the form of a monolith, which is customary for catalysts / particle filters, a heatable heat storage device 4.5 , a storage mat 4.2 and a housing 12 concentric with an axis R and along the exhaust flow 3 are arranged.

The inside of the housing 12 adjacent storage mat 4.2 positions the heat storage device 4.5 and thus the cleaning body 4.1 at least radially in the housing 12 ,

The storage mat 4.2 serves for thermal insulation of the heat storage device 4.5 ,

The heat storage device 4.5 is for receiving and storing a first heat flow 14 in the form of by the cleaning body 4.1 flowing exhaust gas during operation of the motor vehicle 1 furnished and designed as a tube.

The heat storage device 4.5 is radially between the bearing mat 4.2 and the cleaning body 4.1 arranged and surrounds the cleaning body circumferentially. The heat storage device 4.5 stands with the cleaning body 4.1 in direct contact, for optimum heat conduction of the first heat flow 14 to ensure.

Alternatively, the heat storage device 4.5 spaced from the cleaning body 4.1 be arranged and the heat conduction additionally or alternatively by convection and / or by heat radiation and / or a particular elastic intermediate component.

The heat storage device 4.5 It consists at least partially or wholly of a material selected from the group consisting of metal, ceramics, thermal oil, thermal oil, phase change material, in particular salt or metal.

On the outside, ie on the heat storage device 4.5 opposite side of the housing 12 are two heatsinks 16 with several cooling fins 18 arranged. The heat sinks 16 are on opposite sides of the housing 12 arranged and are by a clamping ring 20 attached to this.

The clamping ring 20 has a thermal control device 22 with an actuating device 24 on. The actuating device 24 may be an electrical, a hydraulic or a pneumatic actuator, for example in the form of a drive.

In the 4 to 7 are several other views of the device 4 shown.

The sectional view orthogonal to the axial direction R in 7 shows the radial structure of the device 4 ,

The heat storage device 4.5 points to the cleaning body 4.1 opposite side at the places where the heatsink 16 are arranged, each having a first transfer area 28 on.

The storage mat 4.2 has in the places where the first transfer areas 28 are arranged, in each case a recess 30 , in each case a thermoelectric module 4.3 can be arranged.

Each thermoelectric module 4.3 points to his heat storage device 4.5 opposite side a second transfer area 32 on.

The second transfer area 32 points out of the case 12 out and contacts the heat sink 16 ,

The device 4 is set up so that part of the exhaust stream 3 contained heat over the first heat flow 14 to the heat storage device 4.5 is deliverable. Further, the heat from the heat storage device 4.5 over a second heat flow 34 , in particular over the first transfer area 28 to the thermoelectric module 4.3 dispensable.

The second heat flow 34 may be transferable by heat conduction, in particular substantially without convection.

The heat storage device 4.5 can be used to transfer the second heat flow 34 through the thermoelectric module 4.3 be contacted directly or indirectly.

About a third heat flow 36 is the heat from the second transfer area 32 , in particular to the convection volume flow 4.7 (please refer 1 ), deliverable.

The heat control device 22 includes the actuator 24 that have a transfer agent 40 (eg threaded rod or plunger) with one with the clamping ring 20 coupled bracket 38 is coupled.

By means of the actuating device 24 can be the diameter of the clamping ring 20 change by the clamping ring 20 widened or contracted and thus the scope of the clamping ring 20 changed. This is the thermoelectric module 4.3 via the actuating device 24 relative to the heat storage device 4.5 movable and can be moved between a first and a second positions, wherein in the first position, the thermoelectric module 4.3 in contact with the heat storage device 4.5 is (see 5 and 7 ) and in the second position the thermoelectric module 4.3 through an air gap from the heat storage device 4.5 is disconnected (see 2 ).

In this way, the second heat flow 34 through the thermal control device 22 interruptible.

It should be emphasized that the exhaust gas purification device according to the invention does not necessarily have a switchable second heat flow and thus the actuating device 24 including drive, transmission means 40 and bracket 38 needed. The cleaning device can therefore look exactly as in the 4 to 7 shown, only without the aforementioned parts. The clamping ring 20 is set once and ensures permanent contacting of the module 4.3 with the heat storage device 4.5 , The device has no switchable actuator 24 , the heat is removed from the heat storage device 4.5 delayed and during a longer time to the module 4.3 delivered so that the heat is continuous and also with the engine off to the module 4.3 forwarded and the electrical energy can be passed in this phase to the electrical system and the electrical energy storage device. Thus, the heat is still used even when the vehicle is stationary. Another advantage of the temporal extension of the delivery of thermal energy over the heat storage device 4.5 to the thermoelectric module 4.3 is that the total power required in the exhaust gas purifier 10 provided thermoelectric modules 4.3 less and therefore less expensive thermoelectric modules 4.3 necessary to convert the thermal energy into electrical energy.

The device 4 with the switchable actuator 24 is configured such that in a first operating mode, the heat storage device 4.5 the first heat flow 14 from the exhaust stream 3 absorbs and no second heat flow 34 and in a second Operating mode, the heat storage device 4.5 the second heat flow 34 to the thermoelectric module 4.3 gives off, and no first heat flow 14 receives.

The device 4 is further configured so that in a third operating mode, the first heat flow 14 the heat storage device 4.5 can be fed, and that at the same time the second heat flow 34 to the thermoelectric module 4.3 is deliverable. Here is the second heat flow 34 smaller than the first heat flow 14 , Preferably, the second heat flow corresponds 34 at most 75% of the first heat flow 14 , more preferably at most 50%, and most preferably at most 25%.

In the 8th is a further embodiment of the exhaust gas purification device according to the invention 10 shown.

The heat storage device 4.5 has in this embodiment at its outer periphery 42 one to the thermoelectric module 4.3 facing, radially projecting extension 44 on, in the recess 30 in the storage mat 4.2 sticks out there to the module 4.3 to contact.

The extension 44 is integral to the heat storage device 4.5 formed.

Alternatively, the extension 44 executed as a separate part and on the heat storage device 4.5 be arranged.

The extension 44 has a flat outside 46 on, on which the thermoelectric module 4.3 is coupled heat-transmitting.

Preferably, the thermoelectric module is located 4.3 on the flat outside 46 directly on the extension 44 at.

The heat storage device 4.5 and / or the extension 44 may be formed of a ceramic material having a decreasing thermal conductivity with increasing temperature. Preferably, the ceramic material is an aluminum ceramic. This material can also be used for the heat storage device according to the other embodiments.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 112010003759 T5 [0003]

Claims (15)

Vehicle exhaust purification device ( 10 ), with an exhaust gas-carrying cleaning body ( 4.1 ), one of the cleaning body ( 4.1 ) heatable in operation heat storage device ( 4.5 ) for receiving and storing a first heat flow ( 14 ), and at least one thermoelectric module ( 4.3 ), which is set up to convert thermal energy into electrical energy and transfers heat to the heat storage device ( 4.5 ) is coupled. Exhaust gas purification device according to claim 1, characterized in that the exhaust gas purification device ( 10 ) is a catalyst or a particulate filter, with a housing ( 12 ), in which the cleaning body ( 4.1 ) over a storage mat ( 4.2 ) positioned between the housing ( 12 ) and the cleaning body ( 4.1 ) is arranged. Exhaust gas purification device according to claim 1 or 2, characterized in that the heat storage device ( 10 ) radially between the bearing mat ( 4.2 ) and the cleaning body ( 4.1 ) is arranged and the cleaning body ( 4.1 ) in particular circumferentially surrounds. Exhaust gas purification device according to one of the preceding claims, characterized in that the heat storage device ( 4.5 ) is at least partially or wholly of a material selected from the group consisting of metal, ceramics, thermal oil, thermal oil, phase change material, in particular salt or metal. Exhaust gas purification device according to one of the preceding claims, characterized in that the bearing mat ( 4.2 ) at least one recess ( 30 ) located on the outer surface of the heat storage device ( 4.5 ) a first transfer area ( 28 ) for a second heat flow ( 34 ) from the heat storage device ( 4.5 ) to the thermoelectric module ( 4.3 ) releases. Exhaust gas purification device according to one of the preceding claims, characterized in that the heat storage device ( 4.5 ) on the outer circumference ( 42 ) a the thermoelectric module ( 4.3 ) facing extension ( 44 ), which is designed as a separate part or integrally formed on it. Exhaust gas purification device according to claim 6, characterized in that the extension ( 44 ) a flat outside ( 46 ) at which the thermoelectric module ( 4.3 ) is coupled heat-transmitting, in particular while it rests against it. Exhaust gas purification device according to one of the preceding claims, characterized in that the heat storage device ( 4.5 ) and / or the extension ( 44 ) consists of a ceramic material with a decreasing with increasing temperature thermal conductivity, in particular of an aluminum ceramic. Contraption ( 4 ) for converting waste heat into electrical energy in a motor vehicle ( 1 ), with a vehicle exhaust gas purification device ( 10 ) according to one of the preceding claims, with a heat source, in particular in the form of an internal combustion engine ( 2 ), an exhaust gas flow that can be generated by this heat source ( 3 ), in particular in the form of an exhaust gas stream, with the cleaning body ( 4.1 ) is in flow communication, wherein the second heat flow ( 34 ) from the heat storage device ( 4.5 ), in particular over the first transfer area ( 28 ), to the thermoelectric module ( 4.3 ), and a thermal control device ( 22 ), which are used to control one of the heat flows ( 14 . 34 . 36 ), characterized in that by the heat control device ( 22 ) the second heat flow ( 34 ) is interruptible. Device according to claim 9, characterized in that the device ( 4 ) is configured so that in a first operating mode, the heat storage device ( 4.5 ) the first heat flow ( 14 ) from the exhaust stream ( 3 ) and no second heat flow ( 34 ) and in a second operating mode the heat storage device ( 4.5 ) the second heat flow ( 34 ) to the thermoelectric module ( 4.3 ), and no first heat flow ( 14 ). Device according to one of claims 9 or 10, characterized in that in a third operating mode, the first heat flow ( 14 ) of the heat storage device ( 4.5 ) can be fed, and that at the same time the second heat flow ( 34 ) to the thermoelectric module ( 4.3 ) is deliverable, and that the second heat flow ( 34 ) smaller than the first heat flow ( 14 ), preferably the second heat flow ( 34 ) not more than 75% of the first heat flux ( 14 ), more preferably at most 50%, and most preferably at most 25%. Device according to one of claims 9 to 11, characterized in that for interrupting the second heat flow ( 34 ) the thermoelectric module ( 4.3 ) relative to the heat storage device ( 4.5 ) is movable, in particular via a switchable actuator ( 24 ), which can be moved between two positions, wherein in a first position, the thermoelectric module ( 4.3 ) in contact with the heat storage device ( 4.5 ) and in a second position by a Air gap separated from the heat storage device ( 4.5 ). Method for the inventive operation of a device ( 4 ) according to one of claims 9 to 12, characterized in that during a first phase (P _I ) of the heat storage device ( 4.5 ) a first heat flow ( 14 ) is supplied, that at the same time or after this first phase (P _I ) from the heat storage device ( 4.5 ) a second heat flow ( 34 ) the thermoelectric module ( 4.3 ) is supplied by this thermoelectric module ( 4.3 ) a third heat flow ( 36 ) is discharged. A method according to claim 13, characterized in that the second heat flow ( 34 ) in vehicle standstill the thermoelectric module ( 4.3 ) is supplied. A method according to claim 13 or 14, characterized in that the second heat flow ( 34 ) the thermoelectric module ( 4.3 ) is supplied only until an energy content or a temperature of the heat storage device ( 4.5 ) reaches or falls below a predetermined limit.

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