CN111485978A

CN111485978A - System and method for exhaust gas aftertreatment

Info

Publication number: CN111485978A
Application number: CN201910345820.7A
Authority: CN
Inventors: 米夏埃尔·施赖伯; 斯特凡·朗; 英马尔·朗格尔; 马库斯·施密特; 蒂姆·霍克
Original assignee: Hyundai Motor Co; Kia Motors Corp
Current assignee: Hyundai Motor Co; Kia Corp
Priority date: 2019-01-28
Filing date: 2019-04-26
Publication date: 2020-08-04
Also published as: DE102019201048A1; KR20200094050A

Abstract

A system for exhaust gas aftertreatment comprising a catalytic converter configured to catalytically treat exhaust gas originating from an internal combustion engine, wherein the catalytic converter comprises a gas inlet for receiving air and/or exhaust gas from the internal combustion engine and a gas outlet for discharging treated gas; a gas tank configured to temporarily store air and/or exhaust gas; and a gas distribution system configured to selectively divert at least a portion of air and/or exhaust gas originating from the internal combustion engine to the gas canister upstream of the gas inlet of the catalytic converter and/or downstream of the gas outlet of the catalytic converter, and configured to selectively direct air and/or exhaust gas stored in the gas canister to at least one of the catalytic converter, the exhaust gas outlet, and the internal combustion engine.

Description

System and method for exhaust gas aftertreatment

Technical Field

The present invention relates to a system for exhaust gas aftertreatment, in particular during operation of an internal combustion engine (e.g. a diesel engine) of a motor vehicle. The invention also relates to a method for exhaust gas aftertreatment.

Background

Catalytic converters are exhaust emission control devices that convert toxic gases and pollutants in the exhaust gas from an internal combustion engine into and/or filter less or non-toxic substances from the exhaust gas stream. Catalytic converters are used in particular with internal combustion engines fuelled by gasoline or diesel.

Selective Catalytic Reduction (SCR) is an exemplary and well-known technique used in catalytic converters, in which nitrogen oxides, known as NOx, are converted by means of a catalyst into diatomic nitrogen and water. Gaseous and/or liquid reductants (e.g., anhydrous ammonia, aqueous ammonia, or urea) are added to the exhaust stream and adsorbed onto the catalyst. SCR converters require a certain temperature for proper operation, so that the catalytic reaction usually only starts above the so-called light-off temperature. Typically, the SCR is heated by passing exhaust gases. For this reason, it takes a relatively long time to heat the SCR converter, especially during cold start, and thus until NOx emissions are effectively reduced. Furthermore, when the engine of the motor vehicle is running overrun, i.e. the vehicle is running without a throttle, fresh air is pumped into the SCR system by the engine, which may cool the SCR system and thus lead to lower performance. Furthermore, as NOx emissions increase dramatically over short time scales, acceleration of the engine can present difficulties to conventional SCR systems.

One method commonly used in conjunction with SCR is so-called Exhaust Gas Recirculation (EGR), in which NOx emissions are further reduced by recirculating a portion of the exhaust gas back to the engine. During this time, the recirculated exhaust gas dilutes oxygen from the incoming air stream, which results in a reduction in peak in-cylinder temperatures and NOx emissions. However, at low load and/or low speed conditions of the engine, it is often difficult to achieve high EGR rates because the turbocharger of the respective engine is generally unable to produce the desired boost pressure.

Document DE 102007022494 a1 describes a method for storing the exhaust gases of an internal combustion engine in an exhaust gas tank in a motor vehicle. The stored exhaust gas can then be transferred to a larger external tank, for example at a petrol station.

Document WO 2013/050442a1 describes a method and a device for powering a turbocharger of an internal combustion engine by means of compressed air supplied from an air tank.

Disclosure of Invention

Against this background, there is a need to improve the performance of exhaust gas after-treatment systems for internal combustion engines.

According to one aspect of the invention, a system for exhaust aftertreatment comprises: a catalytic converter configured to catalytically treat exhaust gas originating from an internal combustion engine, wherein the catalytic converter comprises a gas inlet for receiving air and/or exhaust gas from the internal combustion engine and a gas outlet for discharging treated gas; a gas tank configured to temporarily store air and/or exhaust gas; and a gas distribution system configured to selectively divert at least a portion of air and/or exhaust gas originating from the internal combustion engine to the gas canister upstream of the gas inlet of the catalytic converter and/or downstream of the gas outlet of the catalytic converter, and configured to selectively direct air and/or exhaust gas stored in the gas canister to at least one of the catalytic converter, the exhaust gas outlet, and the internal combustion engine.

According to another aspect of the invention, a method for exhaust gas aftertreatment comprises: selectively diverting air and/or exhaust gas originating from the internal combustion engine into a gas tank upstream of a gas inlet of the catalytic converter and/or downstream of a gas outlet of the catalytic converter; temporarily storing air and/or exhaust gas in a gas tank; and selectively directing the air and/or exhaust gas stored in the gas tank to at least one of a catalytic converter, an exhaust outlet, and an internal combustion engine.

Furthermore, a motor vehicle having an internal combustion engine and a system for exhaust gas aftertreatment according to the invention is provided.

One idea of the invention is to store exhaust gases and/or air originating from the combustion engine in a gas tank provided specifically for this task in the vehicle. The air and/or exhaust gases may then be subsequently used for various purposes to improve the performance of the exhaust gas after-treatment and/or even the performance of the engine itself.

Depending on the current operating stage and/or condition of the engine, air, exhaust gases, or a mixture of the two may be released by the engine. In conventional systems, the gas travels through a catalytic conversion system and is eventually blown out at the exhaust outlet (however, part of the gas may be recirculated to the engine via an EGR system). The gas distribution system of the present invention diverts and stores part or all of the gas in a gas tank upstream and/or downstream of the catalytic converter. This directing of the gas is done selectively according to the current operating phase of the system and/or the engine (channeling off). The stored gas can then be used for a later operational stage of the system for a specific purpose in order to improve the performance of the system.

For example, the off-gas may be stored in a gas tank and may be derived from the gasThe tank leads to a catalytic converter for catalytic treatment. In this example, exhaust gas from the engine may be temporarily stored in the gas canister until the catalytic converter reaches an optimal operating temperature and/or a more efficient operating point, for example, during a cold start and/or acceleration phase of the engine. Thus, the gas canister may be used to store the exhaust gas for short emission peaks, e.g., for a few seconds, to reduce CO and NOx emission levels during cold start and acceleration phases. However, the exhaust gas stored in the gas tank may also be directed to the engine to support the EGR system and/or a turbocharger of the engine, which in turn may cause CO₂And (4) reducing.

In another example, fresh air from the engine (via turbocharger injection) may be stored within a gas tank and may be directed from the gas tank into the engine for boosting purposes. In this example, fresh air may be prevented from traveling through the catalytic converter during the overrun phase, which may otherwise cause cooling of the converter. Instead, the air is diverted to a gas tank and from there to the engine, for example, for supercharging a turbocharger. Such boosting of a turbocharger with high boost pressure (fresh air) may increase engine performance, e.g., at low engine speeds, and increase the CO of the system₂The potential is reduced.

The air and/or exhaust gas stored in the gas tank can also be discharged at the exhaust outlet at any time. Thus, the gas tank may be used for storing fresh air during one operating phase of the engine and for storing exhaust gases during different operating phases of the engine. However, it should be understood that there may be applications where both air and exhaust gas may be stored in the gas tank at the same time.

According to an embodiment of the invention, the gas distribution system may be configured to transfer air originating from the internal combustion engine to the gas tank upstream of the gas inlet of the catalytic converter during an overrun phase of the internal combustion engine.

For example, fresh air from the engine may be stored in the gas tank in order to avoid cooling of the catalytic converter during the overrun phase. Thus, the cooling of the SCR device may be reduced compared to conventional systems, which in turn results in an increased efficiency of the SCR device in the subsequent operating phase. The stored air may then be used, for example, to supercharge the engine. Alternatively, however, the air may be blown out only at the exhaust outlet. In the latter case, the air thus bypasses the catalytic converter of the system.

According to an embodiment of the invention, the gas distribution system may be configured to direct air stored in the gas tank to the internal combustion engine during a turbo lag phase of the internal combustion engine. The air may be directed into a turbocharger and/or into an intake manifold of an internal combustion engine.

For example, the air stored during the overrun phase may now be recirculated to the compressor of the turbocharger and/or directly into the intake manifold of the engine. With this recirculation, the engine receives more fresh air (i.e., in addition to the amount of air drawn on the intake of the turbocharger), which can be used to charge the engine so that the engine can produce more torque. Such supercharging of the engine is particularly useful in operating modes in which the turbocharger has less exhaust gas energy to achieve a high boost pressure (so-called turbo lag phase). In principle, however, air may also be led to the engine in other operating phases of the engine.

One benefit of this approach is that the turbocharger can achieve high boost pressures even at low engine speeds and/or low load conditions, enabling high low end torque. In general, it is very difficult to provide a sufficiently high boost pressure at low engine speeds because the exhaust gas energy is not high enough to feed a conventional turbocharger. Now, the invention can be used to achieve engine downshifting to reduce CO at low speeds (i.e., running at very low rpm at long gear ratios)₂And (5) discharging.

According to an embodiment of the invention, the gas distribution system may be configured to transfer exhaust gas originating from the internal combustion engine to the gas tank upstream of a gas inlet of the catalytic converter and/or downstream of a gas outlet of the catalytic converter during a cold start phase and/or an acceleration phase of the internal combustion engine.

For example, the exhaust gas may be bypassed during the cold start phase by a flap valve or similar arranged downstream of the catalytic converter and directed into the gas tank. In other phases it may be advantageous to have the exhaust gas bypass already upstream of the catalytic converter, for example to avoid gaseous and/or liquid reducing agent in the exhaust gas injected into the catalytic converter reaching the gas tank and thus potentially the engine.

According to an embodiment of the invention, the gas distribution system may be configured to direct the exhaust gas stored in the gas tank to a gas inlet of the catalytic converter when an operating temperature of the catalytic converter exceeds a light-off temperature of the catalytic converter.

For example, the exhaust gas may be stored in the gas tank during a cold start phase or during any other operating phase in which the catalytic converter will (yet) not be able to adequately and/or efficiently treat the exhaust gas. Once the engine and/or catalytic converter reach the desired conditions, the exhaust gas may then be recirculated into the catalytic converter. Alternatively or additionally, however, the exhaust gas may also be recirculated into the engine, for example, into the intake manifold, and thus reach the catalytic converter after traveling through the engine. Due to the recirculation of exhaust gases in front of the catalytic converter, e.g. the SCR unit, NOx emissions can be further reduced with higher efficiency, since the SCR unit may reach higher temperatures during this time.

According to an embodiment of the invention, the gas distribution system may be configured to direct the exhaust gas stored in the gas tank to the internal combustion engine during an exhaust gas recirculation phase of the internal combustion engine.

Accordingly, exhaust gas stored within the gas tank may also be recirculated into the engine, e.g., the intake manifold of the engine, to support and/or supplement the EGR subsystem. One advantage of this approach is that large amounts of exhaust gas can be circulated even under low load conditions of the engine, where it is difficult to have high EGR rates based on conventional EGR systems, which are limited by the low boost pressures available under these conditions.

According to an embodiment of the invention, the gas distribution system may be configured to direct the exhaust gas stored in the gas tank to a turbocharger of the internal combustion engine during a turbocharging phase of the internal combustion engine.

For example, exhaust gas may be released through a nozzle at a turbine housing of a turbocharger to drive the turbocharger, i.e., to provide boost increase. This is particularly advantageous in the case of an operating phase of the engine in which the exhaust gases from the engine have only a small energy (e.g. a low acceleration or low speed phase, a turbo lag phase, etc.). Therefore, high torque may be generated even at a long gear ratio and a small rotational speed (i.e., revolutions per minute).

According to an embodiment of the invention, the gas distribution system may comprise a compressor configured to pressurize air and/or exhaust gas directed to and/or from the gas tank.

Thus, air and/or exhaust gas may be stored under pressure in the gas tank. The pressurized air and/or exhaust gas may be used, for example, to pressurize the engine.

According to an embodiment of the invention, the gas tank may be arranged in a trunk, a spare tire compartment or an underbody of the motor vehicle.

However, it should be understood that the gas canister may be mounted in other convenient configurations depending on the particular use case. In some applications, a spare tire compartment may be preferred because the gas canister may be retrofitted into a vehicle with minimal changes to the vehicle configuration. A typical gas tank may have a volume of between 50 and 100 litres, for example 60 litres or 80 litres. A gas canister of this size can be easily fitted into the spare tire compartment and/or trunk of a typical motor vehicle.

The invention will be explained in more detail with reference to exemplary embodiments depicted in the drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. In the drawings, like reference numbers indicate similar or functionally similar elements unless otherwise indicated.

FIG. 1 schematically depicts a system for exhaust aftertreatment in accordance with an embodiment of the invention.

FIG. 2 shows a flow diagram of a method for exhaust aftertreatment according to an embodiment of the invention using the system of FIG. 1.

Fig. 3 schematically shows a motor vehicle comprising the system of fig. 1.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. In general, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

Detailed Description

FIG. 1 schematically depicts a system 10 for exhaust aftertreatment, according to an embodiment of the invention.

The system 10 is configured to clean exhaust gas emitted from an internal combustion engine 101 (e.g., a diesel engine) of a motor vehicle 100 (e.g., the vehicle shown in fig. 3) through a gas pipe 16. To this end, the system 10 features a catalytic converter 2 that includes a series of exhaust after-treatment devices including a diesel oxidation catalyst 13, a diesel particulate filter 14, and a Selective Catalytic Reduction (SCR) device 15. The SCR device 15 is arranged downstream of a particulate filter 14, which in turn is arranged downstream of the oxidation catalyst 13, relative to the engine 101. When combustion occurs within the engine 101, exhaust gas exits the engine 101 through the gas pipe 16, flows into the catalytic converter 2 via the gas inlet 4, exits the catalytic converter 2 at the gas outlet 5, and is finally blown out at the exhaust outlet 6 (e.g., at the tail pipe of the vehicle 100). The engine 101 is also coupled with an intake port 17 via an intake manifold 12 and a turbocharger 11 for injecting fresh air into the engine 101. Thus, depending on the current operating mode or operating phase of the engine 101, air, exhaust gases or a mixture of the two may leave the engine 101 through the gas pipe 16.

A reductant injector (not shown) may be disposed upstream of the SCR device 2 to inject reductant into the exhaust gas stream used as reductant in a catalytic process within the SCR device 2 in a conventional manner. For example, the SCR device 2 may comprise a catalytically active substrate arranged between an inlet surface and an outlet surface (not shown). The substrate may comprise, for example, a ceramic monolith in the usual manner, for example, having a honeycomb-like sub-structure providing a plurality of catalytically active sub-channels through which the exhaust gas is catalytically treated.

It should be understood that the illustrated arrangement of catalytic devices within catalytic converter 2 is merely exemplary, and that various alternative arrangements and/or configurations will be considered by those skilled in the art. For example, the catalytic converter 2 may comprise only an SCR unit between the gas inlet 4 and the gas outlet 5. In this case, the additional catalytic device may be arranged at a different location within the system, for example along the gas pipe 16. However, as those skilled in the art will readily recognize, other catalytic technologies may be used in place of SCR.

In contrast to conventional systems, the system 10 of this embodiment further comprises a gas tank 1 configured to temporarily store air and/or exhaust gas. To this end, the gas tank 1 is fluidly connected with a compressor 7 configured to pressurize the air and/or off-gas before it enters and/or exits the gas tank 1. Thus, the gas tank 1 may in particular store air and/or exhaust gas under pressure. For example, the gas tank 1 may be installed in the trunk, the spare tire compartment, or the underbody of the motor vehicle 100 in fig. 3. The gas tank 1 may have a volume of 60 liters to 80 liters. However, in other embodiments different tank sizes may be provided. The gas tank 1 may be formed of a metal or a metallic material such as a metal alloy or a combination of several metals and/or metal alloys. However, in alternative embodiments, the gas tank 1 may also comprise a plastic or composite material.

For example, the gas tank 1 may have a pressureless tank volume of 60 litres, which means that for a pressure of 5 bar within the gas tank 1 an effective pressurised tank volume of 300 litres is achieved. Assuming a displacement volume of 1.6 litres per two revolutions through the engine 101 at an engine boost pressure of 1.5 bar and a typical engine speed of 1500rpm, it is necessary to lead up to 1800 litres/min or 30 litres/s from the engine 101. Thus, a 300 liter gas canister may cover a 10 second period if all the air and/or exhaust gas injected from the engine 101 is transferred into the gas canister 1. For controlling the gas pressure inside the gas tank 1, the gas tank 1 may comprise one or more pressure sensors 19, which are controlled by a control unit 20 of the system 10.

The gas tank 1 is fluidly connected to a gas distribution system 3 comprising a plurality of distribution pipes 18 and flaps 9a to 9h, wherein each flap 9a to 9h controls the gas flow through the corresponding distribution pipe 18 (reference numerals are assigned to only two exemplary pipes of the distribution pipes in fig. 1 to keep the drawing simple). The distribution system 3 fluidly connects the gas tank 1 to a gas pipe 16 of the system 10 via a distribution pipe 18 and thus to the various components of the system 10, in particular the engine 101, the turbocharger 11, the intake manifold 12, the catalytic converter 2 and the exhaust outlet 6. The purpose of the individual connections via the flap valves 9a to 9h will be explained in further detail below. However, typically, the gas distribution system 3 is configured to selectively divert at least a portion of the air and/or exhaust gases originating from the internal combustion engine 101 to the gas tank 1 upstream of the gas inlet 4 of the catalytic converter 2 and/or downstream of the gas outlet 5 of the catalytic converter 2. The gas distribution system 3 is also configured to selectively direct air and/or exhaust gas stored in the gas tank 1 to at least one of the catalytic converter 2, the exhaust outlet 6 and the internal combustion engine 101 (e.g. via the turbocharger 11 or directly via the intake manifold 12). To this end, the control unit 20 may be configured to control the flap valves 9a to 9h of the gas distribution system 3 in order to regulate the gas flow into and out of the gas tank 1 via the distribution pipe 18.

The method steps of the corresponding method M are depicted in fig. 2. In particular, method M comprises selectively diverting air and/or exhaust gases originating from the internal combustion engine 101 into the gas tank 1 upstream of the gas inlet 4 of the catalytic converter 2 and/or downstream of the gas outlet 5 of the catalytic converter 2 at M1. Method M also includes temporarily storing air and/or exhaust gas in gas tank 1 under M2. Method M further comprises, at M3, selectively directing air and/or exhaust gas stored in the gas tank 1 to the catalytic converter 2, the exhaust outlet 6 and/or the internal combustion engine.

Referring again to FIG. 1, the system 10 may be used to increase the performance of the catalytic process as well as the overall performance of the engine 101 for various operating stages of the engine 101.

For example, during an overrun phase of the vehicle 100, i.e. a mode in which the engine 101 is operated without a throttle, no combustion takes place and therefore only air can be pumped through the engine 101 from the air intake 17 via the turbocharger 11 and the intake manifold 12. In order to avoid cooling of the catalytic converter 2, the flap valve 9g may be closed and the flap valve 9b may be opened, so that all air flowing through the gas pipe 16 from the engine 101 is transferred into the gas tank 1 upstream of the gas inlet 4 (after passing through the compressor 7 and the flap valve 9c, which is also opened). Thus, the catalytic converter 2 (and in particular the SCR unit 15) is not cooled by the air flow. Thus, in the next combustion phase of the engine 101, a higher efficiency of the catalytic process may be achieved, since the NOx emissions are reduced with a higher efficiency due to the higher temperature of the SCR device 2.

Before pumping air and/or exhaust gas into the gas tank 1, the control unit 20 of the system 10 may check, via the pressure sensor 19 of the gas tank 1, whether the gas tank 1 is partially or completely filled with air and/or exhaust gas. Depending on the result, the gas tank 1 can be emptied first, for example by blowing out the stored air and/or exhaust gas at the exhaust outlet 6 (by opening the flap valve 9 a). Once the gas tank 1 is (partially) filled with air during the overrun phase, the stored air can be used for various purposes. However, by opening the

flap valves

9a and 9h, air may alternatively be simply blown out at the exhaust outlet 6 so as to bypass the catalytic converter 2.

However, the stored air may also be used for supercharging the engine 101 by leading pressurized air from the gas tank 1 into the turbocharger 11 and/or the intake manifold 12 of the engine 101. For this purpose, the flap valve 9f and/or the flap valve 9e can be opened. This may be particularly useful in a turbo lag phase of the engine 101 (i.e., an operating phase in which the turbocharger 11 cannot build sufficient pressure by utilizing the exhaust gas flow from the engine 101, for example, at low speeds of the engine 101). As a benefit of this strategy, high boost pressures can be achieved even at low engine speeds, which can be used to achieve a reduction in the speed of the engine 101 at long gear ratios, which in turn can result in improved emissions reductions.

The control unit 20 may be configured to decide which action to take based on what operating phase is expected to follow (e.g. after an overrun phase). To this end, machine learning methods may be utilized in order to optimize the control flow over time. For example, the driving pattern may be employed to predict an upcoming overrun and/or boost phase at some confidence level.

A cold start of the engine 101 is another exemplary operating phase. In this case, exhaust gas is discharged from the engine 101 through the gas pipe 16. Since the catalytic converter 2, in particular the SCR unit 15, may not have reached its operating temperature yet, i.e. the current temperature of the converter 2 is below the light-off temperature, emissions are not reduced properly in the exhaust gas. For this reason, the flap valve 9h can be closed and the

flap valves

9a and 9c can be opened, so that the exhaust gas cannot leave at the exhaust outlet 6, but is transferred into the gas tank 1. Alternatively or additionally, the exhaust gas may be diverted upstream of the gas inlet 4 of the catalytic converter 2 by opening the flap valve 9b (and possibly closing the flap valve 9 g). In order to determine whether the engine 101 is in a cold start phase, suitable sensors (e.g., temperature sensors) may be provided in the catalytic converter 2 and/or the engine 101. The pressure sensor of the gas tank 1 may inform the control unit 20 whether the gas tank 1 is empty or (partially) filled. The gas tank 20 may be emptied before storing the exhaust gas in the gas tank 1, if desired.

Once the temperature of the SCR device 15 and/or the catalytic converter 2 has exceeded a certain threshold value (e.g. a light-off threshold), the stored exhaust gases can be redirected from the gas tank 1 into the catalytic converter 2, for example at the gas inlet 4, by opening the

flap valves

9c, 9b and 9 g. When the catalytic converter 2 is now operating normally, the flap valve 9h can be opened so that treated gas can leave at the exhaust outlet 6. Alternatively, the exhaust gas may also be indirectly redirected into the catalytic converter 2 (e.g., directly at the intake manifold 12) by first directing the exhaust gas through the engine 101. For this purpose, the flap valve 9e may be opened instead of the

flap valves

9c and 9 b. Thus, the exhaust gas may be used in an EGR system to increase internal NOx reduction of the engine 101. One benefit of this approach is that exhaust gas can be circulated in large quantities even under low load or low speed conditions of the engine 101 where the turbocharger 11 itself is difficult to reach the desired pressure.

Similarly, in the case of an acceleration maneuver of the vehicle 100 (for example, a sensor may be provided that measures the acceleration gradient of the engine 101), the exhaust gas originating from the engine 101 may also be diverted to the gas tank 1 upstream or downstream of the catalytic converter 2. The rationale behind this is that a typical catalytic converter 2 may not be able to cope with sudden increases in emissions during such processes, so that these emissions may not be treated in an optimal manner. Also in this case, the exhaust gases may be diverted into the gas tank 1 and then conducted from there back into the catalytic converter 2 (and/or into the engine 101) at a later stage. Also in this case, machine learning methods may be employed to predict certain driving patterns of the vehicle 100, for example, to predict an upcoming acceleration phase.

The exhaust gas stored in the gas tank 1 may also be used for other purposes. In one example, the exhaust gas may be used for supercharging by opening the flap valve 9d and directing the exhaust gas to the nozzle 8, which releases the exhaust gas to drive the turbocharger 11 and thus cause an increase in its supercharging pressure.

In summary, the gas tank 1 for temporarily storing air and/or exhaust gases originating from the combustion engine 101 may be used for improving the exhaust gas aftertreatment and the performance of the engine 101. The exhaust gases may be stored in the gas tank 1 during the cold start phase as well as during the acceleration phase. Furthermore, air may be stored in the gas tank 1 during the overrun phase. The stored air and/or exhaust gas may be used for supercharging purposes of the engine 101 and/or for supercharging purposes of the turbocharger 11 of the engine 101.

In the foregoing detailed description, various features are grouped together in one or more examples or examples for the purpose of streamlining the disclosure. It is to be understood that the above description is intended to be illustrative, and not restrictive. The invention is intended to cover all alternatives, modifications and equivalents. Many other examples will be apparent to those of skill in the art upon reading the above description.

For example, different arrangements of the distribution pipe 18 and the flap valves 9a to 9h are conceivable. For example, the system may be configured to store only air or exhaust gas. Thus, in these cases, all of the flap valves and distribution pipes shown in fig. 1 may not be required.

The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. Many other examples will be apparent to those of skill in the art upon reading the above description.

List of reference numerals

1 gas tank

2 catalytic converter

3 gas distribution system

4 gas inlet

5 gas outlet

6 exhaust outlet

7 compressor

8 spray nozzle

9a-9h flap valve

10 for exhaust gas aftertreatment systems

11 turbo charger

12 air intake manifold

13 Oxidation catalyst

14 particle filter

15 Selective Catalytic Reduction (SCR) device

16 gas pipe

17 air inlet

18 distribution pipe

19 pressure sensor

20 control unit

100 motor vehicle

101 internal combustion engine

M method

Method steps M1-M3

Claims

1. System (10) for exhaust gas aftertreatment, comprising:

a catalytic converter (2) configured to catalytically treat exhaust gases originating from an internal combustion engine (101), wherein the catalytic converter (2) comprises a gas inlet (4) for receiving air and/or exhaust gases from the internal combustion engine (101) and a gas outlet (5) for discharging treated gases;

a gas tank (1) configured to temporarily store air and/or exhaust gas; and

a gas distribution system (3) configured to selectively divert at least a portion of air and/or exhaust gases originating from the internal combustion engine (101) to the gas tank (1) upstream of the gas inlet (4) of the catalytic converter (2) and/or downstream of the gas outlet (5) of the catalytic converter (2), and configured to selectively direct air and/or exhaust gases stored in the gas tank (1) to at least one of the catalytic converter (2), an exhaust outlet (6) and the internal combustion engine (101).

2. The system (10) for exhaust gas aftertreatment according to claim 1, wherein the gas distribution system (3) is configured to transfer air originating from the internal combustion engine (101) to the gas tank (1) upstream of the gas inlet (4) of the catalytic converter (2) during an overrun phase of the internal combustion engine (101).

3. The system (10) for exhaust gas aftertreatment according to claim 1 or 2, wherein the gas distribution system (3) is configured to guide air stored in the gas tank (1) to the internal combustion engine (101) during a turbo lag phase of the internal combustion engine (101), wherein the air is guided into a turbocharger (11) and/or into an intake manifold (12) of the internal combustion engine (101).

4. The system (10) for exhaust gas aftertreatment according to claim 1 or 2, wherein the gas distribution system (3) is configured to transfer exhaust gas originating from the internal combustion engine (101) to the gas tank (1) upstream of the gas inlet (4) of the catalytic converter (2) and/or downstream of the gas outlet (5) of the catalytic converter (2) during a cold start phase and/or an acceleration phase of the internal combustion engine (101).

5. The system (10) for exhaust gas aftertreatment according to claim 1 or 2, wherein the gas distribution system (3) is configured to guide the exhaust gas stored in the gas tank (1) to the gas inlet (4) of the catalytic converter (2) when the operating temperature of the catalytic converter (2) exceeds the light-off temperature of the catalytic converter (2).

6. The system (10) for exhaust gas aftertreatment according to claim 1 or 2, wherein the gas distribution system (3) is configured to guide exhaust gas stored in the gas tank (1) to the internal combustion engine (101) during an exhaust gas recirculation phase of the internal combustion engine (101).

7. The system (10) for exhaust gas aftertreatment according to claim 1 or 2, wherein the gas distribution system (3) is configured to guide the exhaust gas stored in the gas tank (1) to a turbocharger (11) of the internal combustion engine (101) during a turbocharging phase of the internal combustion engine (101).

8. The system (10) for exhaust gas aftertreatment according to claim 1 or 2, wherein the gas distribution system (3) comprises a compressor (7) configured to pressurize air and/or exhaust gas directed to and/or from the gas tank (1).

9. Motor vehicle (100) with an internal combustion engine (101) and a system (10) for exhaust gas aftertreatment according to any one of claims 1 to 8.

10. Motor vehicle (100) according to claim 9, wherein the gas tank (1) is arranged in a trunk, a spare tyre compartment or an underbody of the motor vehicle (100).

11. Method (M) for exhaust gas aftertreatment, comprising:

step M1: -selectively diverting air and/or exhaust gases originating from the internal combustion engine (101) into the gas tank (1) upstream of the gas inlet (4) of the catalytic converter (2) and/or downstream of the gas outlet (5) of said catalytic converter (2);

step M2: -temporarily storing said air and/or exhaust gases in said gas tank (1); and

step M3: selectively directing the air and/or exhaust gases stored in the gas tank (1) to at least one of the catalytic converter (2), an exhaust outlet (6) and the combustion engine (101).

12. A method (M) according to claim 11, wherein air is diverted from the internal combustion engine (101) to the gas tank (1) upstream of the gas inlet (4) of the catalytic converter (2) during an overrun phase of the internal combustion engine (101).

13. A method (M) according to claim 11 or 12, wherein exhaust gases are transferred from the internal combustion engine (101) to the gas tank (1) upstream of the gas inlet (4) of the catalytic converter (2) and/or downstream of the gas outlet (5) of the catalytic converter (2) during a cold start phase and/or an acceleration phase of the internal combustion engine (101).

14. A method (M) according to claim 11 or 12, wherein air is led from the gas tank (1) to the internal combustion engine (101) during a turbo lag phase of the internal combustion engine (101), wherein the air is led into a turbocharger (11) and/or into an intake manifold (12) of the internal combustion engine (101).

15. A method (M) according to claim 12, wherein exhaust gases are led from the gas tank (1) to the gas inlet (4) of the catalytic converter (2) when the operating temperature of the catalytic converter (2) exceeds the light-off temperature of the catalytic converter (2).

16. A method (M) according to claim 12, wherein exhaust gases are led from the gas tank (1) to the combustion engine (101) during an exhaust gas recirculation phase of the combustion engine (101).

17. A method (M) according to claim 12, wherein during a turbocharging phase of the internal combustion engine (101) exhaust gases are led from the gas tank (1) to a turbocharger (11) of the internal combustion engine (101).