WO2012019883A1

WO2012019883A1 - System and method for exhaust gas after-treatment of an internal combustion engine

Info

Publication number: WO2012019883A1
Application number: PCT/EP2011/062310
Authority: WO
Inventors: Stefan Stein
Original assignee: Robert Bosch Gmbh
Priority date: 2010-08-09
Filing date: 2011-07-19
Publication date: 2012-02-16
Also published as: DE102011078495A1

Abstract

The invention relates to a system and method for operating a vehicle, the system comprising means for extracting water from a fluid, in particular a fluid for supporting an exhaust gas after-treatment of the vehicle, characterized in that testing means are provided for testing whether a prescribed first operating state is present, and that control means are provided for enabling the metering out of extracted water into a functional unit of the vehicle in event of a positive test result of the testing means.

Description

description

Title:

System and method for exhaust aftertreatment of an internal combustion engine State of the art

The invention relates to a system and a method for operating a vehicle according to the preamble of the independent claims.

There are already known vehicles, in particular with directly injecting diesel engines, in which the water contained in the fuel or in the compressed air can lead to damage of components to the failure of components of the injection liner or components of the exhaust aftertreatment. The water dissolved in the fuel reduces the lubricating properties especially with diesel fuel and thus leads to increased wear. In parallel, water dissolved in fuel or compressed air can cause corrosion to the components of the injection and exhaust aftertreatment system.

In fuel injection systems, water separators are used which deposit a large part of the free water dissolved in the fuel. Such a water separator is known from DE 10 2004 032 251 B4.

For exhaust aftertreatment systems are known from DE 44 36 415 AI, in which fuel is metered for exhaust aftertreatment via a metering in the exhaust system of an internal combustion engine. The introduction of fuel into the exhaust system is used, for example, to increase the exhaust gas temperature, as certain catalytic reactions in the exhaust aftertreatment, such as the reduction of nitrogen oxides (NOx) or the burning of the particulate matter of a particulate filter at temperatures expire, for the exhaust gas temperature of the internal combustion engine is insufficient in defined operating conditions.

Water in components of exhaust aftertreatment systems, injection systems or compressed air systems of a motor vehicle can lead to corrosion. The significantly reduced lubricity of water compared to diesel fuel can additionally increase the wear of the components during operation. When separating water from a fluid can the quality of the fluid, such as diesel fuel can be increased, however, it can remain fluid residues in the extracted water, so far the extracted water had to be disposed of consuming and expensive as a potential hazardous substance. By injecting the extracted, but potentially contaminated with fluid residues, water in the exhaust line can be dispensed with a costly disposal of water, since the fluid residues in the water here support the exhaust aftertreatment and in for the environment, especially the groundwater, harmless components, especially carbon dioxide and water.

The inventive system and the inventive method for exhaust aftertreatment solve the task with little design effort, the benefits of extraction of water from a fuel such as compressed air or fuel with the exhaust aftertreatment of an internal combustion engine. In particular, the effort of manual water drainage is saved from a sump of a water separator, as the system automatic water draining, even while driving, is possible.

Advantages of the invention:

The system according to the invention and the method according to the invention for operating a vehicle with the features of the independent claims have the advantage that test means are present which check whether a predetermined first operating state exists and that control means are provided which in the case of a positive test result of the test equipment enable the dosing of the extracted water in a functional unit of the motor vehicle. This makes it possible with little design effort, the benefits of extraction of water from a fuel such. Compressed air or fuel with the exhaust aftertreatment, in particular the metering of an auxiliary medium to support the exhaust aftertreatment in the exhaust system of an internal combustion engine to connect. It is particularly advantageous that the expense of manually draining water from a collecting container is saved by means for extracting water from a fluid, since the system enables automatic draining of the water, in particular during operation of the internal combustion engine.

Thus, an automated emptying of the means for the extraction of water from a fluid can be carried out in a simple and cost-effective manner, wherein the means in particular comprise a water separator, so that the expense of manual water drainage can be saved. The extracted water can thus be used or disposed of elsewhere in the motor vehicle. The measures listed in the dependent claims advantageous refinements and improvements of the main claim system are possible.

An advantageous embodiment is that the functional unit is the exhaust system of the internal combustion engine. Thus, in addition, the fluid supply to the exhaust line can be regulated or controlled in terms of time and volume, so that the extracted water in the time in which no fluid is needed to support the exhaust aftertreatment, is metered and not supply the fluid supply for optimum exhaust aftertreatment disturbs.

An advantageous development of the system consists in that, in the case of a second predetermined operating state of the internal combustion engine detected by the testing means, the control means release the metering in of the fluid, in particular after extraction of the water from the fluid, into the exhaust gas line of the internal combustion engine.

In this case, the fluid contains a reduced proportion of water, whereby the lubricating properties of the fluid are better than for the same fluid with a relatively higher proportion of water, especially in diesel fuel, so that the wear of the components of the exhaust aftertreatment system is reduced. The exhaust aftertreatment can be improved by the reduction of the water content in the exhaust aftertreatment fluid, since the fluid has a higher energy density than the same fluid with a relatively higher water content, thereby raising the exhaust gas temperature under the same boundary conditions. In this way, the effectiveness of the exhaust aftertreatment can potentially increase because higher conversion rates can be achieved in other devices for exhaust aftertreatment, such as an oxidation catalyst by the higher exhaust gas temperatures. At the same time, a common control device for the metering of water and fluid can be used in the exhaust system, which limits the number of additional components.

An alternative advantageous embodiment of the system is that the control means release the metering of the fluid independently of the detected operating state. It is advantageous that the fluid can thus be metered independently of the extracted water or in addition to the extracted water.

In the case of the first operating state detected by the testing means, the control means release the metering of the extracted water into the exhaust gas line and block the metering of the fluid and, in the case of the second operating state detected by the checking means, metering the fluid into the meter Release the exhaust system and block the metering of the extracted water into the exhaust system. In the second operating state, the fluid for exhaust gas aftertreatment, for example diesel fuel for regeneration of a diesel particulate filter or compressed air, can be metered into the exhaust line, while in the first operating state the extracted, potentially contaminated with fluid residues water can be made harmless through the exhaust system and disposed of. By the respective blocking of the metering of the other medium, the metering of fluid and water can be controlled or regulated in an advantageous manner.

A further advantageous development is that the test means detect the second operating state when they detect the completion of the release of the dosing of the extracted water into the exhaust line after a release of the dosing of the extracted water in the exhaust system.

In order to avoid corrosion of components of the system for exhaust aftertreatment as far as possible, it is advantageous if the extracted water is removed as quickly as possible from these components. Therefore, it is beneficial if, after the first operating state in which the metering of the extracted water into the exhaust gas line is released, the control device switches over to the second operating state in which the metering of the fluid is released in order to flush the system and the water to remove from the components of the system.

A further advantageous development is that the test means recognize the second predetermined operating state when, in particular, starting from a different operating state from the second operating state, recognize a shutdown request of the internal combustion engine.

Since the flushing of the system with fluid is advantageous, in particular, before a shutdown request of the internal combustion engine, it is advantageous if the checking means, for example a control unit used to control the internal combustion engine, determine with a test program realized, for example, in software form, that a shutdown request of the internal combustion engine is present, to start the flushing process, so that when the engine is switched off no water in the components for exhaust aftertreatment remains and here the risk of corrosion is minimized.

A further advantageous development is that the control means are designed as a valve, in particular as a 3/2-way valve or as a solenoid valve, or as a throttle. The execution of the control means as a valve allows a particularly simple and thus cost-effective design of the control means, in particular a 3/2-way valve, which either releases the connection from the fluid outlet of the water separator to the metering element and at the same time blocks the connection between the water outlet of the water separator and the metering element or releases the connection from the water outlet of the water separator to the metering element and at the same time blocks the connection from the fluid outlet of the water separator to the metering element. At the same time, only the metering in of one of the two media, water or fluid, is released at the same time. Solenoid valves are particularly suitable for releasing or blocking the dosing of the extracted water. Alternatively, a throttle, in particular a controllable throttle, is also suitable for controlling the supply of the extracted water or the fluid to the exhaust line and for releasing or blocking the metering.

A further advantageous development is characterized in that the means for extracting water have a membrane, in particular a semipermeable membrane. Through a membrane that is permeable to water, but impermeable to fuel, the water can be separated from the medium in a simple and cost-effective manner.

A further advantageous development is that the means for extracting water additionally comprise a water purification module. By an additional water purification module, the extracted water can be freed again of impurities and contamination, the cleaning facilitates the use of the extracted water in other functional units of the vehicle, for example for headlight or windscreen cleaning or moistening the vehicle air in the vehicle.

It is particularly advantageous if the water purification module has a semi-permeable membrane, wherein the membrane is permeable to water and largely impermeable to fuel. Thus, the advantages of the two developments mentioned above can be combined.

A further advantageous development consists in that the means for extracting water are designed as hollow bodies, in particular as hollow-fiber membrane modules. A hollow body in which the medium flows through the interior of the hollow body and the water is deposited to the outside is advantageous. In this case, a favorable ratio of surface area of the water separator to volume flow through the hollow body and thus a high Wasserabscheide- rate is achieved. In this case, the use of a hollow-fiber membrane module is particularly advantageous, since this advantage is further enhanced by a multiplicity of thin channels and correspondingly enveloping surfaces. A further advantageous development is that the membrane consists of an ionomer, in particular a sulfonated tetrafluoroethylene polymer.

The use of an ionomer for the membrane has the advantage that the ionomer membrane has the desired property of being permeable to water and permeable to fuel. The group of tetrafluoroethylene polymers is particularly advantageous here for functional, production and durability reasons.

A further advantageous development of the system consists in that the test means comprise detection means, comparison means and detection means. The determining means, in particular investigators for detecting temperatures, especially temperatures of fluid, water or exhaust gas, for time measurement and / or for level measurement, in particular for level measurement of a collecting container of the water separator can thus determine a measured variable, which with a in a comparison means, in particular software stored Comparison values are compared and detecting means which recognize the presence of an operating state of the system when comparing the determined measured variable with the comparison value predetermined in the comparison means. As a result, the process steps running in the system can be automated and / or controlled or regulated.

An advantageous development is that the determination means comprise a level gauge, which determines the amount of extracted water, that the comparison means compare the determined amount with a set threshold value (M _s ) and that the detection means recognize the first operating state, if the determined Amount of extracted water exceeds the predetermined amount threshold (M _s ). In this way, the metering of the water can be released when the water has reached a certain level to avoid overflow of the extracted water from the sump, with automation of the process control through the comparison means and / or detection means is possible.

A further advantageous development of the system consists in that the determination means comprise a timer which determines an operating time of the internal combustion engine that the comparison means compare the determined operating time with a predetermined time threshold (t _s ) and that the detection means recognize the first operating state, if the determined operating time exceeds the predetermined time threshold (t _s ). In this way, the metering of the water can be released when a defined operating time of the internal combustion engine is reached in order to overflow the extracted water from the To avoid collecting container, wherein an automation of the process control over the comparison means and / or detection means is made possible.

A further advantageous development of the system for exhaust aftertreatment is that the detection means comprise a temperature sensor which determines the exhaust gas temperature, that the comparison means compare the determined exhaust gas temperature with a predetermined temperature threshold (T _s ) and the detection means only recognize the first operating state when the temperature determined by the temperature sensor reaches or exceeds the predetermined temperature threshold value (T _s ). In this way it can be avoided that the extracted water does not evaporate when metered into the exhaust system, which can lead to corrosion damage, especially corrosion damage in the exhaust system, and / or contained in the extracted water fluid residues not by further devices for exhaust aftertreatment, especially in the exhaust system Internal combustion engine arranged further devices for exhaust aftertreatment, be sufficiently cleaned and / or converted into harmless to the environment substances.

A further advantageous development is that downstream of the control means dosing means for metering the extracted water and / or the fluid are arranged in the exhaust line. By metering, in particular directly on or arranged in the exhaust line dosing, the dosing accuracy and direction of the amount to be dosed of the water and / or the fluid can be improved. For example, an undesirable wall wetting of the exhaust gas line can be reduced by the extracted water. In addition, can be prevented by the dosing a backflow of exhaust gases from the exhaust gas to the control means.

A further advantageous development of the system consists in that the dosing means comprise a metering unit and an injection unit. By segregating the function of metering the amount of fluid or water and the injection unit gives greater flexibility in the design and positioning of the components. In particular, the injection unit can be optimally positioned in or on the exhaust gas line in order to meter in the extracted water and / or the fluid into the exhaust gas flowing through the exhaust gas line.

A further advantageous development of the system consists in that the injection unit is designed as an injection valve, in particular as an outwardly opening injection valve or as an outwardly opening poppet valve. The use of an injection valve as an injection unit offers the advantage that when the injection valve is closed there is a secure separation of exhaust gas in the exhaust gas line and water or fluid in the system. Especially The advantage here is the use of an outwardly opening valve, since outwardly opening valve reduce the risk of coking of the fluid at the valve seat and thus a change in the metered amount. Outwardly opening poppet valve additionally offer the advantage that the water or the fluid arrive in a wide cone angle in the exhaust system and are thus well distributed in the exhaust gas flow.

A further advantageous development is that at least two of the amount of the means for extracting water, the control means, the dosing and the test means are at least partially integrated in a common device, in particular with a common housing. This reduces the number of components to be assembled, resulting in time savings and cost reduction in assembly.

An alternative advantageous development consists in that the control means release the metering of the extracted water downstream of the metering unit and upstream of the injection unit. This corrosion damage to the metering unit can be avoided because it is not flowed through by the extracted water. This also allows the use of cheaper materials in the metering unit.

A further alternative advantageous development is that the control means release the metering of the fluid upstream of the metering unit or via a second injection unit. Due to the separate metering of extracted water and fluid, the variability of the system can be increased since the water and the fluid are metered into the exhaust line at different locations, whereby an individual optimization of the metering point for water and fluid is made possible. In addition, the use of a second injection unit allows the simultaneous metering of extracted water and fluid, which increases the application possibilities of the exhaust aftertreatment system.

A further advantageous development is that the control means comprise a solenoid valve, a check valve and / or a throttle. By using a check valve, a solenoid valve or a throttle in a connecting line from the water outlet of the water separator to the injection unit, a backflow of the fluid via the connecting line to the water separator, in particular to a collecting container for the extracted water can be prevented. Thus, the risk of re-mixing of the fluid with the extracted water can be avoided. A further advantageous development of the system consists in that the control means comprise a connection line which connects a fluid outlet at the means for extraction of water or a fluid source directly to the metering unit or the second injection unit. This development has the positive effect that only the supply of the extracted water must be blocked or released, so that the use of a simple and inexpensive valve is possible here for control.

An alternative advantageous development is that the functional unit is a cleaning system for vehicle windows or vehicle headlights, in particular a collecting container of this cleaning system. It is advantageous that the cleaning liquid can be replenished by the extracted water.

Another alternative advantageous development is that the functional unit is an automotive air conditioning system, in particular a unit for moistening the air of a vehicle interior. It is advantageous that the water for moistening the room air during driving occurs and does not need to be refilled externally.

An advantageous method for operating a vehicle is characterized in that a predetermined mixing ratio of extracted water and the fluid is adjusted by the control means in the time average. As a result, not only the extracted water or the fluid can be metered into the functional unit, but also any mixing ratios of extracted water and the fluid, so that, for example, the fluid can be cooled by the extracted water or better atomized.

An advantageous development of the method is that the control means, in particular a solenoid valve with a frequency greater than 1 Hz is driven in order to achieve a dispersion or mixture of extracted water and the fluid. Due to the high drive frequency, in the event that the fluid does not mix with the water, a dispersion of extracted water and fluid can be prepared and this dispersion can be metered into the functional unit. In the event that water and fluid can be mixed, a homogeneous mixture can be achieved. In this case, a solenoid valve for the required drive frequencies is particularly suitable.

A further advantageous development of the method consists in detecting physical input variables of extracted water and the fluid in a first method step and specifying a desired value for a mixing ratio of extracted water and the fluid, and in a second method step as a function of Setpoint and the determined physical input variables, the mixing ratio over a drive time or drive frequency of the control means, in particular a solenoid valve or a 3/2-way valve is set. As a result, the physical properties of the extracted water or of the fluid, for example the temperature or the pressure during the preparation of a mixture or a dispersion can be taken into account in a simple manner.

Drawings:

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

Fig. 1 and Fig. 2 show the inventive system for exhaust aftertreatment in a schematic representation

Fig. 3 to Fig. 6 show concrete embodiments of the system in a schematic representation

Fig. 7 shows details of the means for extracting water used in the exhaust aftertreatment system of the present invention

Fig. 8 shows a flow chart for controlling mixture formation of extracted water and fluid

Short description of the embodiments

In Fig. 1, the inventive system for exhaust aftertreatment is shown in a schematic manner.

The exhaust gas aftertreatment system has a tank 12 filled with fluid 12, which is connected via connecting lines 13, 14 to the means 30 for the extraction of water 31, the connecting lines comprising a conveying means 20.

The means 30 are connected via a line 19 to a functional unit 100 and via a line 17 to an exhaust line 40 of an internal combustion engine 5 of a motor vehicle. Furthermore, the system comprises test means 80 for detecting an operating state of the internal combustion engine 5 and control means 90.

The conveying means 20 delivers the fluid 12 from the tank via the connecting lines to the means 30 for the extraction of water 31. By the means, the fluid 12, the water 31 withdrawn. The test means 80 determine whether a first operating state is present and influence the control means 90 such that in the case of a positive test result of the test means 80, the dosing of the extracted water 31 via the connecting line 19 in a functional unit 100 of the motor vehicle is released. In this case, the functional unit 100 can be, for example, the collecting container of the wiper water, a collecting container for moistening the air for vehicle interior air conditioning or the exhaust tract 40 of the internal combustion engine 5. In this case, the claimed exhaust aftertreatment system comprises the components within the dashed line in FIG. 1, but may also comprise one or more of the further components, in particular the components shown outside the dashed line to illustrate and explain the function.

In the example shown in FIG. 2, the functional unit 100 is the exhaust tract 40 of the internal combustion engine. In Fig. 2, the means 30 for the extraction of water 31 are shown as a water separator, which is connected via two connecting lines 17, 19 with the control means 90. Here, a first connection line 17 for the fluid 12 leads from a fluid outlet of the means 30 for extraction of water 31 to the control means 90 and a second connection line 19 for the extracted water 31 from a water outlet of the means 30 for extraction of water 31 to the Control means 90. Of the control means 90, a further connecting line 42 leads into the exhaust line 40 of the internal combustion engine. 5

In Fig. 3, a first concrete embodiment of the inventive system for exhaust aftertreatment is shown. The system has a tank 12 filled with fluid 12, which is connected via supply line 13 to a conveyor element 20. The conveying element 20 is connected via a further supply line 14 with a filter 25, which is connected via a further supply line 16 with the means 30 for the extraction of water 31, here shown as a water separator 30 with a semi-permeable membrane 71. At the water separator 30, two outlet openings are formed, which are referred to below as fluid outlet 32 and water outlet 34. The water separator 30 is connected via the fluid outlet 32 and a connecting line 17 to a high-pressure pump 99 of a fuel injection system under further with an internal combustion engine 5. The water separator 30 is further connected via the fluid outlet 32 and connecting lines 17,18 with a control means 35, in the example shown a 3/2 -way valve connected. In addition, the water separator 30 is connected to the control means 35 via the water outlet 34 and a connecting pipe 19, the connecting pipe 19 comprising an extracted water collecting tank 31. The control means 35 is connected via a connecting line 42 with a dosing means 50, which at one with the Internal combustion engine 5 connected exhaust line 40 is arranged. In addition, the illustrated system has a temperature sensor 47 arranged in the exhaust line 40. Furthermore, a level indicator 36 and arranged on the control means 35, a timer 37, wherein the temperature sensor 47, the level meter 36 and / or the timer 37 are connected via signal lines to a control unit 24 which contains comparison means 38 and detection means 39, to the collecting container 29 which may be formed by software and / or hardware. The lying within the dashed line components represent components of the claimed system for exhaust aftertreatment, the other components are only to illustrate and explain the function of the system.

In internal combustion engines 5, a fluid 12 mixed with water 31 can lead to damage of injection components up to failure of the injection system. The water 31 contained in the fluid 12 can already lead to these damages, which is why some manufacturers for high-pressure injection systems already water separator with deposition rates of> 95% of the fluid 12, i. be required in the fuel, dissolved water. In this case, the separated water 31 may contain residues of the fluid 12. By the inventive system for exhaust aftertreatment, this water 31 can be disposed of easily and without environmental hazard by the extracted water 31 is disposed of from the water 30 via the dosing 50 in the exhaust line 40. Existing residues of fluid 12, in particular fuel, are burned in the exhaust line 40 and thus made harmless.

The fluid 12, in particular fuel, is conveyed out of the tank 10 via the connecting lines 13, 14 to the water separator 30 by means of the conveying element 20, wherein the fluid 12 flows through the filter 25, which filters out particles and impurities from the fluid 12, which the water separator 30 or damage other system components or could reduce the effectiveness of the water separator 30.

Via the fluid outlet 32 of the water separator 30 and the connecting lines 17, the fluid 12 continues to flow to the high-pressure pump 99 and is supplied to the internal combustion engine 5 in a known manner.

Alternatively, the delivery element 20 can be dispensed with if the fluid 12 is sucked out of the tank 10 by the high-pressure pump 99 or a pre-delivery pump, not shown, upstream of the high-pressure pump 99. Furthermore, the filter 25 can also be arranged between the tank 10 and the conveying element 20.

For low particulate contaminants or fluids 12, the system may be run without filter 25. As it flows through the water separator 30, the water 31 dissolved in the fluid 12 is extracted and fed to a collecting container 29. As a very effective water separator 30, for example, a hollow body shown in FIG. 7, for example, a so-called hollow fiber membrane module 76 may be used, in which the fluid 12 flows within thin pipes 78 and the extracted water through the thin pipes 78 formed as a semipermeable membrane the gaps 79 are extracted. In this case, the hollow-fiber membrane module 76 with its many thin pipes 78 is characterized by having a large surface area and high separation rates of water 31 from the fluid 12. For level measurement of the extracted water 31, a level meter 36 is arranged on the collecting container 29, via which the amount of extracted water 31 in the collecting container 29 can be measured. Alternatively, the collecting container 29 may also be integrated in the water separator 30.

From the water separator 30, the fluid 12 flows via the fluid outlet 32 through the connecting lines 17,18 to the control means 35 and the extracted water 31 from the collecting container 29 via the connecting line to the control means 35th

In this case, the system comprises test means 80 which check whether a predetermined operating state is present and control means 90 which release the dosing of the extracted water 31 in the case of a positive test result of the test means 80. The control means 90 comprise those actuators which are suitable for releasing and blocking the dosing of the extracted water 31. In Fig. 3, the control means 90 is formed as a 3/2-way valve 35, alternatively, solenoid valves 27 or throttles 28, in particular adjustable throttles, can be used as a control means 90.

The test means 80 comprise detection means, comparison means, and detection means. In this case, the detection means comprise sensors 36 for determining the amount of extracted water 31, in particular a level gauge 36 on the collecting container 29, timers for determining an operating time of the internal combustion engine 5, in particular a timer 37 and temperature sensors 47 for determining the exhaust gas temperature.

The comparison means compare a measured variable determined by the determination means with a predetermined comparison quantity. In this case, the comparison means may for example be stored in software in the control unit 24, wherein the control unit 24 itself also belongs to the test means 80.

The detection means detect an operating state by the comparison of a determined measured variable of the determination means with a predetermined comparison variable from the comparison means. The first operating state is when the test means 80 recognize that a defined level of the collecting container 29 has been reached or a predetermined time interval of the operating time has elapsed. If the test result is positive, the dosing of the extracted water 31 is released by the control means 90.

A second predetermined operating state is present when the first operating state is not detected and the test means 80, in particular the temperature sensor 37, additionally recognize that the exhaust gas temperature is above a temperature threshold value.

If the test means 80 detect the second predetermined operating state, the control means 90 release the dosing of the fluid 12, in particular after extraction of the water 31 from the fluid 12, into the exhaust line 40 of the internal combustion engine 5.

In this case, such control means 90, for example valves, in particular 3/2-way valves 35, advantageous in the case of the detected by the test means 80 first operating state, the metering of the extracted water 31 in the exhaust line 40 and lock the metering of the fluid 12 and in the case of the detected by the test means 80 second operating state, the metering of the fluid 12 in the exhaust line 40 and release the metering of the extracted water 31 into the exhaust line 40.

The test means 80 recognize the second operating state when they detect the completion of the release of the dosing of the extracted 31 in the exhaust line 40 after a release of the dosing of the extracted water 31 in the exhaust line 40. As a result, the water remaining in the components after metering in the extracted water 31 is flushed out by the fluid 12 from the components of the exhaust aftertreatment system, in particular from the control means 90 and downstream of the control means 90, so that the residence time of water 31 in the conduit 42 and in the dosing means 50 are as short as possible to avoid corrosion damage by the water 31. It is particularly desirable that when stopping the engine 5, no water 31 remains in the control means 35 or the dosing means 50 and in the conduit 42, since with the internal combustion engine 5, the risk of corrosion by the water 31 is the highest.

The checking means 80 also recognize the predetermined second operating state if they detect a shutdown request of the internal combustion engine 5, in particular on the basis of an operating state different from the second operating state. The detection of the shutdown request of the internal combustion engine can be done for example via the control unit 24. The system may be further developed by the level gauge 36, which determines the amount of extracted water 31 in the sump, sending a signal to the comparison means 38, the comparison means 38 providing the determined amount of extracted water 31 with a predetermined amount threshold (M _s ) and the detection means 39 detect the first operating state when the determined amount of the extracted water 31 exceeds the predetermined quantity threshold value (M _s ).

Alternatively or additionally, the system comprises a timer 37, which determines an operating time of the internal combustion engine 5, wherein the determined operating time of the comparing means with a predetermined time threshold (t _s ) is compared and the detection means recognize the first operating state, when the determined operating time the exceeds the predetermined time threshold (t _s ).

This can prevent the water separator 30 or the collecting container 29 from being overfilled. In addition, it can be prevented by a regular emptying, the water evaporates 31 in the water and mixed at an undesirable location with the fluid 12 again.

Alternatively or additionally, the system comprises the temperature sensor 47, which determines the exhaust gas temperature, wherein the comparison means compare the determined exhaust gas temperature with a predetermined temperature threshold (T _s ) and the detection means recognize the first operating state only when the temperature detected by the temperature sensor 47 predetermined temperature threshold (T _s ) reached or exceeded.

The control means 90 is connected via a connecting line 42 to the exhaust line 40, wherein between the control means 90, in particular a 3-2-way valve 35, and the exhaust line metering means 50 may be arranged. These dosing means 50 can be carried out both in one piece, as well as in several parts, the dosing means 50 comprising a metering unit 51 and an injection unit 52.

The injection unit is preferably designed as an injection valve in order to achieve a dense separation of the exhaust gas in the exhaust line 40 and the fluid 12 and / or the water 31. Outwardly opening valves have the advantage that they are more robust in terms of coking and associated problems such as changing injection quantities or leaks than inwardly opening valves. Particularly advantageous is the use of an outwardly opening poppet valve, since in addition a broad injection cone of the fluid 12 and / or of the water 31 is achieved in the exhaust line 40, wherein the eindo- The fluid 12 and / or the metered-in water can mix well with the exhaust gas in the exhaust line 40.

Fig. 4 shows an alternative embodiment, wherein the water outlet 34 of the water separator 30 is connected via a connecting line 19 with a connecting line 43 between the metering unit 51 and the injection unit 52 of the dosing. In the connecting line 19, a solenoid valve 27 and a throttle 28 are arranged, with which the dosing of the extracted water can be released and limited. Alternatively, only the solenoid valve 27 or the throttle 28, in particular a controllable throttle, can be used to release the dosing of the extracted water 31. It is advantageous if the throttle 28 is arranged as close as possible to the connecting line 43 in order to avoid a backflow of the fluid 12 into the connecting line 19 and to reduce pressure oscillations in the connecting lines 19, 43. Alternatively, the use of a check valve instead of the throttle 28 in the connecting line 19 is possible.

5, a further embodiment is shown, wherein the fluid outlet 32 of the water separator 30 is connected via a connecting line 17 with a dosing means 50. Alternatively, a control means 90, in particular a solenoid valve 27 or a throttle 28 may additionally be arranged in the connecting line 17 here as well.

The water outlet 34 of the water separator 30 is connected via a connecting line 19 with a further dosing means 54, wherein control means 90 are arranged in the connecting line 19. As a control means 90, a solenoid valve 27 and a throttle 28 are arranged, with which the metering of the extracted water 31 can be released and limited. Alternatively, only the solenoid valve 27 or the throttle 28, in particular a controllable throttle, can be used to release the dosing of the extracted water 31.

In the system for exhaust gas aftertreatment shown in FIG. 3, the control means 90, in particular the solenoid valve 27 or the throttle 28, can release the metering independently of the detected operating state. This makes it possible to simultaneously meter in the extracted water 31 and the fluid 12 into the exhaust line 40 of the internal combustion engine.

Fig. 6 shows an alternative embodiment of the system for exhaust aftertreatment, wherein the fluid 12 is not fuel, but compressed air, in particular the compressed air from the compressed air system is a utzfahrzeuges. A tank 10, in this example a compressed air reservoir, is connected via a line 12 to a conveying element 20 which is designed as a pressure generator and to a further line 14, 16 with a water separator 30, which is preceded by a filter element 25. At the water separator 30, a fluid outlet 32 and a water outlet 34 is formed. The water outlet 34 opens into the collecting container 29, which is connected via the line 19,42 with the dosing means 50. The fluid outlet 32 is also connected via the line 17,18,42 with the dosing means 50, but has a further connecting line which connects the fluid outlet 32 with the pneumatic brake system 60 of a utzfahrzeuges. Between the water separator 30 and the metering element 50, the control 35 is arranged.

The fluid 12 is pressurized by the conveying element 20 and flows from the tank 10 to the water separator 30. In the water separator 30, for example, by cooling the air, the water from the air is condensed and separated. The metering of the fluid 12, i. the compressed air, is analogous to the description of FIG. 1.

FIG. 8 shows a flow chart for controlling a mixture formation of extracted water 31 and fluid 12. A method for operating a vehicle is proposed in which the control means 90, or by the control of the 3/2-way valve 35 or of the solenoid valve 27, a predetermined mixing ratio of extracted water 31 and the fluid 12 is set in the time average. In this case, a duration of a control of the control means 90, in particular of the solenoid valve 27 and the 3/2-way valve 35, is varied during an operating state in which extracted water 31 is metered in, so that the desired mixing ratio of extracted water 31 and fluid 12 sets. Frequencies greater than 1 Hz, ie a drive time less than one second, are advantageous, since a fine dispersion or mixture can be achieved with such a short drive time. The maximum drive time is determined by the reciprocal of the drive frequency. Based on the physical input variables, for example, pressure p _{3 of} the fluid 12, pressure pi of the extracted water 31, back pressure p ₂ in the functional unit, temperatures Τι / Τ _{2 of} the extracted water 31 and the fluid 12, possibly further input variables and a desired value of the mixing ratio between extracted water 31 and fluid 12, the driving duration and driving frequency of the control means 90 are determined.

Claims

Claims:

A system for operating a vehicle, the system comprising means (30) for extracting water (31) from a fluid (12), in particular a fluid (12) for assisting exhaust gas aftertreatment of the vehicle, characterized in that test equipment ( 80) are provided, which check whether a predetermined first operating state exists and that control means (90) are provided, which in the case of a positive test result of the test means (80) the metering of the extracted water (31) in a functional unit (100) of the motor vehicle release.

2. System according to claim 1, characterized in that the functional unit (100) is an exhaust line (40) of the vehicle.

3. System according to claim 2, characterized in that the control means (90) in the case of one of the test means (80) detected second predetermined operating state, the metering of the fluid (12), in particular after extraction of the water (31) from the fluid (12 ), in the exhaust line (40) of the vehicle release.

4. System according to claim 1 or 2, characterized in that the control means (90) release the metering of the fluid (12) independently of the detected operating state.

5. The system according to claim 3, characterized in that the control means (90) in the case of the test means (80) detected first operating state, the metering of the extracted water (31) in the exhaust line (40) release and the metering of the fluid (12 ) and, in the case of the second operating state detected by the testing means, release the metering of the fluid (12) into the exhaust line (40) and block the metering of the extracted water (31) into the exhaust line (40).

6. System according to any one of claims 2, 3 or 5, characterized in that the test means (80) recognize the second operating state when, after a release of the dosing of the extracted water (31) in the exhaust line (40) the completion of the release the dosing of the extracted water (31) in the exhaust line (40) recognize.

7. System according to any one of claims 2, 3, 5 or 6, characterized in that the test means (80) recognize the second predetermined operating state, if they recognize, in particular starting from a different operating state from the second operating state, a shutdown request of the vehicle.

8. System according to any one of claims 1 to 7, characterized in that the control means (90) as a valve, in particular as a 3/2-way valve (35) or as a solenoid valve (27) or as a throttle (28) are formed.

9. System according to any one of claims 1 to 8, characterized in that the means (30) for the extraction of water (31) comprises a membrane (71), in particular a semipermeable membrane (71).

10. System according to one of claims 1 to 9, characterized in that the means (30) for the extraction of water (31) additionally comprise a water purification module (70).

11. System according to claim 10, characterized in that the water purification module (70) has a semi-permeable membrane (71), wherein the membrane (71) for water (31) is permeable and largely impermeable to fuel.

12. System according to any one of claims 1 to 11, characterized in that the means (30) for the extraction of water (31) as a hollow body (75), in particular as a hollow fiber membrane module (76) are formed.

13. System according to any one of claims 9 to 12, characterized in that the

Membrane (71) consists of an ionomer, in particular a sulfonated Tetraflourethy- len- polymer exists.

14. System according to one of claims 1 to 14, characterized in that the

Test means (80) comprise detection means, comparison means and detection means.

15. System according to claim 14, characterized in that the determining means comprise a level gauge (36) which determines the amount of extracted water (31) that the comparison means the determined amount of the extracted water (31) with a predetermined amount threshold ( M _s ) and that the recognition Detect the first operating state, when the determined amount of the extracted water (31) exceeds the predetermined amount threshold (M _s ).

16. System according to one of claims 14 or 15, characterized in that the determining means comprise a timer (37), which determines an operating time of an internal combustion engine (5) of the Fahrzueges (1) that the comparison means the determined operating time with a predetermined time Compare threshold (t _s ) and that the detection means recognize the first operating state when the determined operating time exceeds the predetermined time threshold (t _s ).

17. The system according to any one of claims 15 or 16, characterized in that the determining means comprise a temperature sensor (47) which determines the exhaust gas temperature that the comparison means compare the determined exhaust gas temperature with a predetermined temperature threshold (T _s ) and the detection means recognize the first operating state only if the temperature detected by the temperature sensor (47) reaches or exceeds the predetermined temperature threshold value (T _s ).

18. System according to one of claims 2 to 17, characterized in that downstream of the control means (90) dosing means (50, 54) for metering the extracted water (31) and / or the fluid (12) into the exhaust line (40) are.

19. System according to claim 18, characterized in that the dosing means (50, 54) comprise a metering unit (51) and an injection unit (52).

20. System according to claim 19, characterized in that the injection unit (52) is designed as an injection valve, in particular as an outwardly opening injection valve or as an outwardly opening poppet valve.

21. System according to any one of claims 1 to 20, characterized in that at least two of the quantity of the means (30) for extracting water (31), the control means (90), the dosing means (50, 54) and the test means ( 80) are at least partially integrated in a common device, in particular with a common housing.

A system according to any one of claims 19 to 21, characterized in that the control means (90) enable the metered addition of the extracted water (31) downstream of the metering unit (51) and upstream of the injection unit (52).

23. System according to any one of claims 19 to 21, characterized in that the control means (90) to release the metering of the fluid (12) upstream of the metering unit (51) or via a second injection unit (54).

24. System according to claim 23, characterized in that the control means (90) comprise a solenoid valve (27), a check valve and / or a throttle (28).

25. System according to claim 23 or 24, characterized in that the control means (90) comprise a connection line (17) having a fluid outlet (32) on the means (30) for the extraction of water (31) or a fluid source directly with the Connect the metering unit (51) or the second injection unit (54).

26. System according to claim 1, characterized in that the functional unit (100) is a cleaning system for vehicle windows or vehicle headlights-werfern, in particular a collecting container of this cleaning system is.

27. System according to claim 1, characterized in that the functional unit (100) is an automotive air conditioning system, in particular a unit for humidifying the air of a vehicle interior.

28. A method for operating a vehicle, wherein water (31) from a fluid (12), in particular a fluid (12) is extracted to support an exhaust aftertreatment of the vehicle, characterized in that it is checked whether a first predetermined operating condition exists and that in the case of a positive test result, the dosing of the extracted water (31) into a functional unit (100) of the vehicle will be released.

29. A method for operating a vehicle according to claim 28, characterized in that by control means (90), in particular by a 3/2-way valve (35) or a solenoid valve (27), on average over time, a predetermined mixing ratio of extracted water ( 31) and the fluid (12) is adjusted.

30. A method for operating a vehicle according to claim 29, characterized in that the control means (90), in particular a solenoid valve (27), is driven at a frequency higher than 1 Hz to a fine dispersion or mixture of extracted water (31). and to reach the fluid (12).

31. A method for operating a vehicle according to one of claims 28 to 30, characterized in that in a first method step, physical input variables of extracted water (31) and the fluid (12) are detected and a desired value for a mixing ratio of the extracted water ( 31) and the fluid (12) is predetermined, and in a second method step depending on the desired value and the determined physical input variables, the mixing ratio over a drive time or drive frequency of the control means (90), in particular a solenoid valve (27) or a 3/2 Way valve (35), is set.