NL2002651C2 - VEHICLE FITTED WITH A BURNING ENGINE. - Google Patents

Description

VEHICLE FITTED WITH A BURNING ENGINE

The present invention relates to a vehicle provided with a combustion engine to which an outlet for exhausting exhaust gases is connected, the outlet being provided with a catalyst and a soot filter.

The invention further relates to an outlet for use in a vehicle.

10 For vehicles equipped with a combustion engine in the form of a diesel engine, the use of a soot filter is nowadays mandatory. The soot filter is designed to capture the soot particles in the exhaust gases so that they do not or to a lesser extent are released into the outside air. At lower temperatures of the exhaust gases, the soot particles are collected in the filter and at high temperatures the soot filter is automatically regenerated so that the filter does not become clogged.

To allow regeneration of the filter even at lower exhaust gas temperatures, a catalyst is provided. For example, a catalyst makes it possible to provide efficient regeneration of the filter at a temperature of 280 ° C instead of 600 ° C.

25

It is a problem of the known vehicle that, despite the catalyst and the soot filter, the emissions may contain gases which are harmful to humans and the environment.

It is the object of the present invention to provide a vehicle in which the above-mentioned problem is at least partially solved.

2

To this end, the vehicle of the type mentioned in the preamble has the special feature that the outlet is provided with a by-pass for diverting the exhaust gases around the catalyst, wherein at least one of the by-pass or the outlet is provided with an opening valve and closing the bypass and / or the outlet. This makes it possible to temporarily disconnect the catalyst from the outlet by opening or closing the valve, wherein at least the majority of the exhaust gases are supplied directly to the filter.

In a catalyst, among other things, NOx is converted into NO2, with NO2 allowing regeneration of the filter at lower temperatures. The operation of the catalyst also depends on the temperature of the exhaust gases. At lower temperatures, a sufficiently large amount of NO2 is produced to ensure efficient regeneration at these low temperatures. But at higher temperatures, more NO becomes? produced than is necessary for this regeneration. This surplus is emitted by the exhaust. In higher concentrations is NO? harmful to human health. In particular in circumstances where vehicles are used in an enclosed space, for example in factory halls or flower auctions, this can lead to dangerous situations. By switching off the catalyst in this type of condition by passing the exhaust gases around the catalyst, the emission of NO2 is reduced.

When the temperature of the exhaust gases is not high enough to achieve efficient regeneration in the filter and the exhaust gases are passed around the catalyst, the filter will take up the soot particles without efficiently breaking them down. However, when the catalyst is subsequently switched on again, complete regeneration will take place so that the soot particles accumulated in the filter will be broken down.

Preferably, the bypass branches off from the outlet upstream of the catalyst. In this way there is an efficient diversion of the exhaust gases. More preferably, the bypass downstream of the catalyst comes together with the outlet. The diversion then forms, as it were, an alternative route for the exhaust gases at the location of the catalyst, so that it is at least substantially switched off.

15

The term upstream and downstream as used must be related to the flow direction of the exhaust gases. Upstream, therefore, should be interpreted as towards the combustion engine and downstream of the combustion engine.

It should be noted here that it is also possible to introduce the catalyst in the by-pass, the exhaust gases being led through the catalyst in the diverted state. In this embodiment, the outlet is then not provided with a catalyst.

In a preferred embodiment of the vehicle according to the invention, the by-pass comprises a second exhaust. In this embodiment the vehicle can be provided with two outlets, one of the outlets being provided with a catalyst and the other serving as a by-pass. Both outlets are preferably provided with a filter for collecting the soot particles. In a particularly preferred embodiment, the second outlet again meets the first outlet downstream of the catalyst. In this embodiment the by-pass is formed by the second outlet.

In a further preferred embodiment of the vehicle according to the invention, the soot filter is located downstream of the catalyst. This enables efficient regeneration in the state in which the catalyst is switched on. More preferably, the filter extends downstream of the junction of the outlet and the bypass, so that a single filter can be provided for the vehicle.

15

In a further preferred embodiment of the vehicle according to the invention, the valve comprises a three-way valve, the valve being situated at the branch of the diversion. In a first position of the valve the exhaust gases are fed to the by-pass and in a second position of the valve the exhaust gases are fed through the outlet provided with catalyst. In this way an efficient flow of the gases takes place.

In a further preferred embodiment of the vehicle according to the invention, the by-pass is provided with the valve. When the valve in the bypass is closed, the exhaust gases will be passed through the catalyst into the outlet. If the valve is now opened, the catalyst outlet is indeed not closed, but due to the reducing resistance of the opened by-pass, the majority of the exhaust gases will flow through the by-pass. The provision of a valve in the by-pass is simpler than the provision of a valve in the outlet provided with the catalyst.

It is noted here that although the valve is opened and closed, it is also possible to partially open or close the valve, for example depending on the amount of NO2 required in the filter. In this way it is possible to partially disconnect the catalyst from the outlet.

10

In a further preferred embodiment the vehicle comprises at least a detector for detecting indication means and a control system for opening and closing the valve, wherein the control system is adapted to open or close the valve in dependence on a detected indication means. When the vehicle detects an indication means with the aid of the detector, the control system will open or close the valve to guide the exhaust gases around the catalyst or possibly to guide the exhaust gases back through the catalyst.

The indication means can for instance be arranged in the road surface over which the vehicle drives and can for instance be arranged at an entrance into an enclosed space. When the vehicle enters this space, the catalytic converter will be disconnected automatically to reduce the emission of harmful gases. The indication means are preferably designed as a metal loop arranged in the road surface. The detector is then arranged to detect such a loop. Such a detection system as such is known.

6

It may also be possible to use electromagnetic radiation, for example in the form of light and / or radio signals, to automatically open or close the valve.

5

In a further preferred embodiment of the vehicle according to the invention, the outlet comprises a temperature sensor and a control system for opening and closing the valve, wherein the control system is adapted to open or close the valve in dependence on a measured temperature in the outlet . Especially at high temperatures, the emission of harmful NO2 is high due to the increased effect of catalyst and independent regeneration of the filter. When the temperature of the exhaust gases is sufficiently high, the control system can guide the exhaust gases around the catalyst by opening or closing the valve.

The control system is preferably adapted to control the valve to guide the exhaust gases around the catalyst at a measured temperature higher than 400 ° C, preferably 500 ° C and more preferably 600 ° C. It has been found that this produces good results with regard to NO2 emissions.

In a further embodiment of a vehicle according to the invention, the valve can be operated manually, preferably from the driver's cab of the vehicle. In this way it is possible for the driver to open or close the valve for diverting the exhaust gases or not.

It should be noted that a combination of the above controls is also possible. For example, it may be possible to divert the exhaust gases only when the temperature of the exhaust gases is high and the vehicle is in an enclosed space, which is detected by the detector. The driver can then manually switch the diversion on or off.

The invention further relates to an exhaust as described above for use in a vehicle.

The invention will be further elucidated with reference to figures shown in the drawing of a preferred embodiment of the invention, in which: - Figs. 1 schematically shows a first embodiment of an outlet for in a vehicle, and; FIG. 2 schematically shows a second embodiment of an outlet for in a vehicle.

Figure 1 shows an exhaust system 1 for use in a vehicle. The system comprises an outlet 3 which is connected to a diesel engine 2. In the outlet 3 a catalyst 6 is arranged which provides for efficient regeneration of the soot filter 5 which is arranged near an end 3a 25 of the outlet 3. In normal use, the exhaust gases are led through the catalyst 6 and the filter 5, as is shown in Figure 1 with a dashed line.

A by-pass 4 is provided at the outlet 3. The bypass 4 branches off from the outlet 3 upstream of the catalyst 6 and comes back together with the outlet 3 downstream of the catalyst 6. The bypass 4 is made of the same material as outlet 3 and forms, as it were, 8 a second, parallel exhaust pipe. The bypass 4 is provided with valve 7, the valve being shown in Figure 1 in the closed position. The open position is shown schematically in dotted line.

5

For example, if the vehicle is in an enclosed space where high concentrations of NO2 should not be emitted, the valve 7 can be opened. To this end, a control system 8 is provided which can be controlled 10 by the driver of the vehicle. Because the bypass 4 is now not closed, the majority of the exhaust gases will flow through the bypass 4 as a result of the reduced resistance with respect to the outlet 3 provided with the catalyst 6. The exhaust gases are at least substantially around the catalyst led. This will significantly reduce the production of NO2 in the catalyst. The exhaust gases are then emitted via the diversion 4 via the soot filter 5.

In the diverted state, a reduced regeneration can take place in the soot filter. The filter 5 will store the soot particles in this state. Depending on the capacity of the filter 5, such a diversion can take several hours. When the catalyst 6 is subsequently switched on again by closing the valve 7, the filter 5 can then be completely regenerated again.

A temperature sensor 9 is also arranged in the outlet 3. Depending on the measured temperature, the control system 8 can open or close the valve to divert the exhaust gases around the catalyst 6 or not. For example, when the temperature exceeds 600 ° C and the vehicle is in an enclosed space, the valve 7 can be opened to reduce NO2 emissions.

Figure 2 shows another embodiment, in which the valve 7 is designed as a three-way valve. The valve 7 is then located at the location of the branch of the bypass 4 of the outlet 3. In this embodiment, the outlet 3 and the bypass 4 are of the same design, wherein in this example the bypass 4 is provided with the catalyst 6.

10

In Figure 2 the diverted state is indicated by the dotted line II, wherein the valve 7 closes the bypass 4 which is provided with the catalyst 6. The exhaust gases hereby flow through the outlet 3 and the filter 5 to the outlet 3a.

It is noted that the invention is not limited to the embodiments shown, but also extends to other preferred variants that fall within the scope of the appended claims.

Claims (13)

A vehicle provided with a combustion engine to which an outlet for exhausting exhaust gases is connected, the outlet being provided with a catalyst and a soot filter, the outlet being provided with a by-pass for diverting the exhaust gases around the catalyst, and wherein at least one of the by-pass or the outlet is provided with a valve for opening and closing the by-pass and / or the outlet, characterized in that the vehicle further comprises at least one detector for detecting indication means, and a control system for opening and closing the valve, wherein the control system is adapted to open or close the valve in dependence on a detected indication means. 2. Vehicle according to claim 1, wherein the detector is adapted to detect a metal loop in a road surface. Vehicle as claimed in claim 1 or 2, wherein the detector is adapted to detect electromagnetic radiation, for example in the form of light and / or radio signals. 25 The vehicle according to claim 1, 2 or 3, wherein the bypass taps off the outlet upstream of the catalyst. The vehicle of claim 4, wherein the bypass downstream of the catalyst meets the outlet. A vehicle according to any one of the preceding claims, wherein the diversion comprises a second outlet. The vehicle according to any of the preceding claims 1 to 5 and 6, wherein the soot filter is downstream of the catalyst. 8. Vehicle according to any of the preceding claims 4 to 7, wherein the valve comprises a three-way valve, wherein the valve is situated at the branch of the diversion. Vehicle according to one of the preceding claims 1 to 8, wherein the diversion is provided with the valve. 15 10. Vehicle as claimed in any of the foregoing claims 1-9, wherein the outlet comprises a temperature sensor and the vehicle comprises a control system for opening and closing the valve, wherein the control system is adapted to, depending on a measured temperature, open or close the valve. 11. Vehicle as claimed in claim 10, wherein the control system is adapted to control the valve to guide the exhaust gases around the catalyst at a measured temperature higher than 400 ° C, preferably 500 ° C and more preferably 600 ° C. The vehicle according to any of the preceding claims 1 to 30 and 11, wherein the valve can be operated manually. 13. Exhaust for use in a vehicle according to one of the preceding claims 1 to 12.