WO2021204476A1

WO2021204476A1 - Exhaust gas extraction probe and method for exhaust gas measurement

Info

Publication number: WO2021204476A1
Application number: PCT/EP2021/055830
Authority: WO
Inventors: Karl-Werner DILLY; Oliver ANDRICK
Original assignee: Testo SE & Co. KGaA
Priority date: 2020-04-08
Filing date: 2021-03-09
Publication date: 2021-10-14
Also published as: DE102020109886A1

Abstract

The invention relates to improvements in the technical field of exhaust gas measurement. To this end, an exhaust gas extraction probe (1) is, inter alia, proposed, which is attached to an exhaust gas pipe by means of a clamping device (2), wherein the clamping device (2) acts on the inside of the exhaust gas pipe, but has no contact on the outer side.

Description

Exhaust gas sampling probe and method for exhaust gas measurement

The invention relates to an exhaust gas sampling probe and a method for exhaust gas measurement.

Exhaust gas sampling probes are used to take exhaust gas samples from an exhaust gas flow, for example of a motor vehicle, on a test bench.

When used on motor vehicles, the exhaust gas sampling probes are inserted into an exhaust pipe of the motor vehicle in order to take an exhaust gas sample from the interior of the exhaust pipe and feed it to an exhaust gas analysis via the exhaust gas sampling probe. The exhaust gas sampling probe is attached to the exhaust pipe for this purpose. This is done with a type of screw clamp that is clamped to a wall of the exhaust pipe. In particular when the exhaust pipe is framed with a vehicle trim, the fastening of the exhaust gas sampling probe with a screw clamp can be difficult or even impossible. This can make exhaust gas measurement difficult.

In particular when using a comparatively long exhaust gas sampling probe to obtain the exhaust gas sample, the exhaust gas sample can condense out on its way through the exhaust gas sampling probe to an analysis device. This fact can falsify the analysis results and make exhaust gas measurement difficult.

The object of the invention is therefore to provide an exhaust gas sampling probe and a method of the type mentioned at the beginning which simplify the exhaust gas measurement. To achieve the object, an exhaust gas sampling probe of the type mentioned at the outset is proposed which comprises the means and features of the first independent claim directed to an exhaust gas sampling probe. To solve the problem, an exhaust gas sampling probe with a clamping device for fastening the exhaust gas sampling probe to an exhaust pipe is proposed, the clamping device being designed to clamp the exhaust pipe from the inside at at least two spaced-apart locations in order to fasten the exhaust gas sampling probe to the exhaust pipe.

With the help of the clamping device of the exhaust gas sampling probe according to the invention, a preferably non-positive connection between the exhaust gas pipe and the exhaust gas sampling probe can thus be established, in which the clamping device only clamps the exhaust gas pipe from the inside. External contact between the clamping device and the exhaust pipe, which can be difficult or even impossible depending on the installation situation of the exhaust pipe, is avoided in this way. To fix the exhaust gas sampling probe, the clamping device is thus only inserted at least a little way into the exhaust pipe and brought into the previously described clamping system with the at least two spaced-apart points on the exhaust pipe.

The exhaust gas sampling probe can have a probe tube which can be inserted into the exhaust gas pipe. In this way, the exhaust gas can be extracted with the aid of the exhaust gas extraction probe at a certain distance from an outlet opening of the exhaust pipe from the interior of the exhaust pipe. This avoids unintentional and / or unregulated dilution of the exhaust gas and thus promotes the most accurate exhaust gas measurement possible.

The clamping device can be between the at least two points at which it contacts the exhaust pipe from the inside, be clamped when it has assumed its clamping position for fastening the exhaust gas sampling probe to the exhaust pipe. The clamping device of the exhaust gas sampling probe can thus first be introduced into the exhaust pipe and then be supported in its clamping position from the inside at two different points on an inner wall of the exhaust pipe. In this way, the clamping device can be clamped in the clamping position between the at least two points of the exhaust pipe and the exhaust gas sampling probe can be securely fastened to the exhaust pipe.

In a particularly preferred embodiment of the exhaust gas sampling probe, it is provided that the clamping device has at least two clamping jaws. The clamping jaws are preferably spring-loaded. The clamping jaws can then be moved, for example against the action of a restoring force, from a clamping position that is distant from one another into a releasing position that is closer to one another. If the clamping jaws are each connected to a handle, the exhaust gas sampling probe can be fitted into its exhaust gas sampling position with one hand.

The clamping jaws can be mounted pivotably about a common pivot point. In this way it is possible to move the clamping jaws between their clamping position and the release position by means of a pivoting movement. The pivot point can in this case be arranged between the clamping jaws and the handles which are each assigned to the clamping jaws.

In one embodiment of the exhaust gas sampling probe, it is provided that at least one of the clamping jaws of the clamping device can be equipped with spacers for adapting the clamping device to different clamping diameters. This way it is easy to customize the exhaust gas sampling probe and in particular its clamping device on exhaust pipes with different inside diameters possible.

The clamping device can be arranged on the probe tube of the exhaust gas sampling probe. The clamping device is preferably arranged displaceably on the probe tube of the exhaust gas sampling probe. If the clamping device is arranged displaceably on the probe pipe of the exhaust gas sampling probe, the probe pipe of the exhaust gas sampling probe can be inserted into exhaust gas pipes at different depths. The displaceable arrangement of the clamping device on the probe tube of the exhaust gas sampling probe is particularly advantageous when a minimum insertion depth or a defined exhaust gas sampling point within the exhaust gas pipe has to be reached with the exhaust gas sampling probe for taking an exhaust gas sample. In this way, the exhaust gas sampling probe can simply be adapted to different exhaust pipes and also to different insertion depths.

In one embodiment of the exhaust gas sampling probe, it is provided that the probe tube of the exhaust gas sampling probe has a grid. The grid is preferably attached to the outside of the probe tube. To provide a grid, the probe tube can be designed, for example, as a corrugated tube. With the help of the grid, it is possible to arrange the clamping device in different defined positions on the probe tube. The grid of the probe tube can thus predetermine defined holding positions of the clamping device on the probe tube.

The probe tube can also have a scale on the outside for determining an insertion depth or insertion depth of the probe tube into an exhaust pipe. This facilitates the simple handling of the exhaust gas sampling probe without further measuring equipment to determine the current insertion depth of the Probe tube into the exhaust pipe from which an exhaust sample is to be taken.

The exhaust gas sampling probe can have a sampling line.

The extraction line is preferably arranged or formed in or on the probe tube. Furthermore, the exhaust gas sampling probe can have a feed line. The feed line can also be in or on the probe tube

Exhaust gas sampling probe can be arranged or formed. Via the feed line to the exhaust gas sampling probe, it is possible to specifically dilute the exhaust gas sample with a dilution gas. As a dilution gas, the exhaust gas sample can, for example, be supplied with external air. With the aid of the admixture of a diluent gas, for example external air, it can be prevented that the exhaust gas contained in the exhaust gas sample condenses out inside the probe tube on the way through the probe tube and the exhaust gas measurement is falsified.

In order to improve the handling of the exhaust gas sampling probe and also the accuracy of an exhaust gas measurement of exhaust gas samples taken with the exhaust gas sampling probe, an exhaust gas sampling probe with the means and features of the second independent claim directed to such an exhaust gas sampling probe is proposed. Accordingly, it is provided in particular that the exhaust gas sampling probe has a feed line for admixing a diluent gas, in particular supply air, into an exhaust gas sample taken with the exhaust gas sampling probe. It has been found that the targeted admixture of a diluent gas can improve the exhaust gas measurement. With the targeted admixture of a diluent gas, an unintentional condensation of the exhaust gas sample on its way through the sampling probe to an analysis device and thus a falsification of the exhaust gas measurement can be prevented. In an advantageous embodiment of the exhaust gas sampling probe, it is provided that it has a mixing chamber, preferably at its distal end located in the measuring position in an exhaust gas pipe. The previously mentioned feed line for admixing a diluent gas can be connected to this mixing chamber. In the volume provided by the mixing chamber in which the admixing of the diluent gas takes place, the conditions for admixing the exhaust gas sample can be constant and thus the admixing of the diluent gas can take place as precisely as possible.

The mixing chamber can have a sampling opening through which the exhaust gas sample enters the mixing chamber from the exhaust pipe. The mixing chamber can be connected directly to an inner lumen of an exhaust pipe via the sampling opening. The feed line for admixing the dilution gas can open into the mixing chamber, so that the dilution gas is actually only admixed to the exhaust gas sample already located within the mixing chamber.

This exhaust gas sampling probe can also have a sampling line for taking the exhaust gas sample. The extraction line can be connected to the aforementioned mixing chamber of the exhaust gas extraction probe. In this way it is possible to take exhaust gas samples already diluted with the dilution gas from the mixing chamber and to send them to an analysis.

The clamping device can have a ventilation channel with which exhaust gas that has not been removed can flow out via the clamping device. It is also possible that the

Clamping device forms at least a portion of the extraction line and / or at least a portion of the aforementioned feed line of the exhaust gas extraction probe. The sampling line of the exhaust gas sampling probe and / or the feed line of the exhaust gas sampling probe can be arranged and / or formed at least in sections on or in the probe tube of the exhaust gas sampling probe.

In order to ensure that the exhaust gas sample is taken from the exhaust pipe at a certain distance from an inner wall of the exhaust pipe, the exhaust gas sampling probe can have at least one spacer. The at least one spacer can preferably be provided on a distal end of the probe tube, on which a sampling opening of the exhaust gas sampling probe can also be arranged or formed. The at least one spacer can also be arranged or formed on a housing of a mixing chamber of the exhaust gas sampling probe, for example the one already mentioned above.

The exhaust gas sampling probe can have a sample inlet cross-section through which the exhaust gas sample can enter the mixing chamber, in particular on a sampling nozzle protruding into the aforementioned mixing chamber. Of the

The sample inlet cross-section is preferably positioned between an opening cross-section of the feed line into the mixing chamber and a connection of the extraction line to the mixing chamber. This ensures that the dilution gas supplied via the supply line to the mixing chamber is reliably mixed with the exhaust gas sample supplied via the sample inlet cross-section of the mixing chamber before the mixture of exhaust gas sample and dilution gas is discharged from the mixing chamber via the extraction line.

The clamping device can also have a locking device for securing clamping legs of the clamping device. The clamping legs of the clamping device can be connected to one another via a swivel joint. The swivel joint can have two swivel axes which are spaced apart from one another and between which the probe tube of the exhaust gas extraction device and in particular also the extraction line and / or the feed line of the exhaust gas extraction probe is / are passed.

To achieve the object, a method for exhaust gas measurement using an exhaust gas sampling probe is also proposed, which has the means and features of the independent claim directed to such a method. Thus, in particular, a method for exhaust gas measurement using an exhaust gas sampling probe is proposed, in which a dilution gas is added to an exhaust gas sample via the exhaust gas sampling probe. The dilution gas can be used to prevent the exhaust gas sample from condensing out on its way through the exhaust gas sampling probe and falsifying an exhaust gas measurement.

The diluent gas can be found in the exhaust gas sample

Exhaust gas sampling probe and preferably mixed in a mixing chamber of the exhaust gas sampling probe. When carrying out the method, in particular an exhaust gas sampling probe can be used, as claimed in the claims directed to such.

The admixture of the diluent gas can preferably take place immediately after the exhaust gas sample has been taken from the exhaust gas flow. The diluent gas is preferably added to the exhaust gas sample at the point where it was taken. The mixture of exhaust gas sample and diluent gas can then be fed to an exhaust gas analysis device for exhaust gas measurement and / or an exhaust gas measurement can be carried out. The invention is thus concerned with improvements in the technical field of exhaust gas measurement. For this purpose, among other things, the exhaust gas sampling probe is proposed, which can be fastened to an exhaust pipe by means of the clamping device. The clamping device is set up to act on the inside of the exhaust pipe, but not to contact it on the outside.

The invention will now be described in more detail using an exemplary embodiment, but is not limited to this exemplary embodiment. Further exemplary embodiments result from the combination of the features of individual or several protection claims with one another and / or in combination of individual or several features of the exemplary embodiment. Show it:

1 shows a perspective view of an exhaust gas sampling probe with a clamping device which is arranged on a probe tube of the exhaust gas sampling probe,

FIG. 2 shows a perspective illustration of the clamping device of the exhaust gas sampling probe from FIG. 1,

3 shows a sectional view through a distal end of the probe tube of the exhaust gas sampling probe from FIG. 1, on the basis of which a mixing chamber of the exhaust gas sampling probe for admixing a diluent gas into a withdrawn exhaust gas sample can be seen

4 shows a perspective view of the exhaust gas sampling probe from the previous figures, the clamping device being arranged closer to the distal end of the probe tube compared to FIG. FIG. 1 shows an exhaust gas sampling probe, designated as a whole by 1, with a clamping device 2. The clamping device 2 can be seen particularly well in the individual part illustration of FIG. The clamping device 2 is used to fasten the exhaust gas sampling probe 1 in or on an exhaust pipe or exhaust pipe not shown in the figures, for example of a motor vehicle. With the aid of the clamping device, the exhaust gas sampling probe 1 can be fixed in the position required for the exhaust gas measurement. The clamping device 2 is designed to clamp the exhaust pipe on the inside at at least two spaced-apart locations from the inside in order to fix the exhaust gas sampling probe 1 to the exhaust pipe.

FIG. 1 shows that the exhaust gas sampling probe 1 has a probe pipe 3 that can be inserted into an exhaust pipe. The clamping device 2 is clamped in the use position within the exhaust pipe between the at least two points of the exhaust pipe. The exhaust gas sampling probe is inserted into the exhaust pipe with at least part of the clamping device 2 and can be fastened to the exhaust pipe from the inside, i.e. within the exhaust pipe, with the aid of the clamping device 2, without the exhaust pipe being contacted or acted upon on its outside by the clamping device 2 .

To attach the exhaust gas sampling probe 1 to the exhaust pipe, the already free and thus accessible interior space of the exhaust gas pipe is used by the exhaust gas sampling probe 1 and the clamping device 2. For the fastening of the exhaust gas sampling probe 1, it is therefore irrelevant whether and, if so, how the exhaust pipe to which the exhaust gas sampling probe 1 is to be fastened is accessible from the outside. With the aid of its clamping device 2, the exhaust gas sampling probe 1 can also be used in a vehicle whose rear apron largely or completely surrounds an exhaust pipe of the vehicle. The clamping device 2 shown has two clamping jaws 4. The clamping jaws 4 can be moved, for example, against a restoring force from the clamping position shown in FIG. 2 into a loosening position that is closer to one another, in order to introduce the clamping jaws 4 of the clamping device 2 into an exhaust pipe. In order to automatically bring the clamping jaws 4 into their clamping position and, above all, to be able to hold them there, at least one return element, for example a return spring, can be arranged between the clamping legs 5 on which the clamping jaws 4 are arranged.

The clamping jaws 4 are provided with spacers 13 which enable the clamping device 2 to be adapted to different clamping diameters. Each clamping leg 5 has a handle 14 at its end facing away from the clamping jaw 4. The clamping legs 5 are connected to one another via a swivel joint 15. The pivot joint 15 comprises two pivot axes 16 spaced apart from one another, between which the probe tube 3 of the exhaust gas sampling probe 1 is passed. With the aid of a locking device 17 of the clamping device 2, the clamping legs 5 can be fixed.

A comparison of FIGS. 1 and 4 makes it clear that the clamping device 2 is arranged displaceably on the probe tube 3 of the exhaust gas sampling probe 1. The exhaust gas sampling probe 1 can thus be adjusted to different vehicle types and insertion depths that must be reached with the distal end of the probe tube 3.

The probe tube 3 has a grid 6 on the outside. The grid serves to arrange the clamping device 2 in different defined positions on the probe tube 3. The probe tube 3 is for this purpose as a corrugated tube formed, on the outside of which the grid 6 results from the wave shape of the corrugated pipe.

In one embodiment of the probe tube 3 of the exhaust gas sampling probe 1 shown in the figures, this is provided with a scale on the outside. The scale is used to determine an insertion depth of the probe tube 3 into an exhaust pipe on which the exhaust gas extraction and the exhaust gas measurement with the aid of the exhaust gas extraction probe 1 is to be carried out.

The exhaust gas sampling probe 1 also has a sampling line 7. The extraction line 7 is formed in the probe tube 3 according to FIG. The exhaust gas sample taken from the exhaust gas flow at the distal end of the exhaust gas sampling probe 1 can be fed via the sampling line 7 to an analysis device to which the exhaust gas sampling probe 1 can be connected.

The exhaust gas sampling probe 1 also has a feed line 8 which is used to mix a dilution gas, for example supply air, into an exhaust gas sample taken from an exhaust gas flow by the exhaust gas sampling probe 1.

At its distal end located in an exhaust gas pipe in the measurement position, the exhaust gas sampling probe 1 also has a mixing chamber 9. The extraction line 7 and the feed line 8 for admixing the diluent gas are connected to the mixing chamber 9. The exhaust gas sampling probe 1 has a sampling opening 10 which is formed on a sampling nozzle 18 protruding into the mixing chamber 9. The exhaust gas sample from the exhaust gas flow can enter the mixing chamber 9 via the sampling opening 10 and the sampling nozzle 18 and can be mixed there with the diluting gas supplied to the mixing chamber 9 via the feed line 8. The sampling nozzle 18 has a

Sample inlet cross section 19. Of the

The sample inlet cross section 19 is positioned within the mixing chamber 9 between an opening cross section 21 of the feed line 8 and a connection 20 of the extraction line 7 to the mixing chamber 9. The exhaust gas sample taken from the exhaust gas flow enters the mixing chamber 9 via the sample inlet cross section 19. The arrangement of the sample inlet cross section 19 within the mixing chamber 9 and between the

Mouth cross-section 21 of the supply line 8 and the connection 20 of the extraction line 7, it is ensured that the dilution gas supplied via the supply line 8 of the mixing chamber 9 is reliably mixed with the exhaust gas sample supplied via the sampling port 18 of the mixing chamber 9 before the mixture of exhaust gas sample and dilution gas passes through the Withdrawal line 7 is discharged from the mixing chamber 9.

The mixture of exhaust gas sample and the added dilution gas can then be discharged from the mixing chamber 9 via the extraction line 7. Both the extraction line 7 and the supply line 8 run at least in sections within the probe tube 3.

A plurality of spacers 11 are arranged at the distal end of the exhaust gas sampling probe 1. Specifically, the spacers 11 are formed on the distal end of the probe tube 3 and here on a housing 12 of the mixing chamber 9.

With the exhaust gas sampling probe 1, the method for exhaust gas sampling described below can be carried out.

Here, an exhaust gas sample is taken from an exhaust gas flow with the aid of the exhaust gas sampling probe 1. Via the exhaust gas sampling probe 1, the exhaust gas sample is converted into a diluting gas within the exhaust gas sampling probe 1, in particular at its sampling location mixed in. The dilution gas is added to the exhaust gas sample in the mixing chamber 9 of the exhaust gas sampling probe 1. The mixture of exhaust gas sample and diluent gas is then fed to an exhaust gas analysis device via the sampling line 7 of the exhaust gas sampling probe 1 and an exhaust gas measurement is carried out.

/ List of reference symbols

List of reference symbols

Clamping device

Probe tube

Jaw

Clamp leg

Rasterization

Sewing line

Supply line

Mixing chamber

Sampling port

Spacers

casing

Spacer

handle

Swivel joint Swivel axis Locking device Sampling nozzle Sample inlet cross-section Connection from 7 to 9 Mouth cross-section from 8 in 9

/ Expectations

Claims

Expectations

1. Exhaust gas sampling probe (1) with a clamping device (2) for fastening the exhaust gas sampling probe (1) to an exhaust pipe, the clamping device (2) being set up to clamp the exhaust gas pipe from the inside at at least two spaced-apart locations in order to connect the exhaust gas sampling probe ( 1) to be attached to the exhaust pipe.

2. Exhaust gas sampling probe (1) according to the preceding claim, wherein the exhaust gas sampling probe (1) has a probe tube (3) which can be inserted into an exhaust gas pipe.

3. exhaust gas sampling probe (1) according to any one of the preceding claims, wherein the clamping device (2) is clamped between the at least two points.

4. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein the clamping device (2) has at least two, preferably spring-loaded, clamping jaws (4), in particular which can be moved, for example against a restoring force, from a clamping position distant from one another into a releasing position approaching one another .

5. Exhaust gas sampling probe according to the preceding claim, wherein at least one of the clamping jaws (4) can be equipped with spacers for adapting the clamping device (2) to different clamping diameters.

6. exhaust gas sampling probe (1) according to any one of the preceding claims, wherein the clamping device (2), preferably displaceably, is arranged on the probe tube (3) of the exhaust gas sampling probe (1).

7. exhaust gas sampling probe (1) according to one of the preceding claims, wherein one or the probe tube (3) has a grid (6), in particular is designed as a corrugated tube, in order to arrange the clamping device (2) in different, preferably defined, positions on the probe tube (3).

8. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein one or the probe tube (3) of the exhaust gas sampling probe (1) preferably has a scale on the outside for determining an insertion depth of the probe tube (3) in an exhaust gas pipe.

9. exhaust gas sampling probe (1) according to any one of the preceding claims, wherein the exhaust gas sampling probe (1) has a sampling line (7), in particular wherein the sampling line is arranged and / or formed on or in one or the probe tube (3).

10. Exhaust gas sampling probe (1), in particular according to one of the preceding claims, wherein the exhaust gas sampling probe (1) has a supply line (8) for admixing a diluent gas, in particular supply air, into an exhaust gas sample.

11. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein the exhaust gas sampling probe, preferably at its distal end located in the measuring position in an exhaust pipe, has a mixing chamber (9), is connected to the feed line (8) for admixing a diluent gas.

12. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein the exhaust gas sampling probe (1), in particular one or the mixing chamber (9), has a sampling opening (10) for an exhaust gas sample.

13. exhaust gas sampling probe (1) according to any one of the preceding claims, wherein the exhaust gas sampling probe (1) one or the Has extraction line (7) for taking an exhaust gas sample, in particular wherein the extraction line (7) is connected to one or the mixing chamber (9).

14. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein the exhaust gas sampling probe (1), in particular on a sampling nozzle (18) protruding into the mixing chamber (9), has a sample inlet cross section (19) which, preferably within the mixing chamber (9) , is positioned between an opening cross-section (21) of the supply line (8) and a connection (20) of the extraction line (7) to the mixing chamber (9).

15. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein the clamping device (2) has a ventilation channel through which the exhaust gas can flow out, and / or wherein the clamping device (2) at least a portion of one or the sampling line (7) and / or forms at least a portion of one or the supply line (8).

16. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein one or the sampling line (7) and / or one or the supply line (8) is arranged and / or formed at least in sections on or in one or the probe tube.

17. Exhaust gas sampling probe (1) according to one of the preceding claims, wherein the exhaust gas sampling probe (1), in particular at a distal end of the probe tube (3), has at least one spacer (11), preferably wherein the at least one spacer (11) on a housing (12) one or the mixing chamber (9) is arranged or formed.

18. exhaust gas sampling probe (1) according to one of the preceding claims, wherein the clamping device (2) has a locking device (17) for securing clamping limbs (5), and / or wherein clamping limbs (5) of the clamping device (2) are connected to one another via a swivel joint (15), preferably wherein the swivel joint (15) has two pivot axes (16) spaced from one another, between which the probe tube (3), in particular the extraction line (7) and / or the supply line (8), is / are guided.

19. A method for exhaust gas measurement using an exhaust gas sampling probe (1), in particular one

Exhaust gas sampling probe (1) according to one of the preceding claims, a diluent gas being added to an exhaust gas sample via the exhaust gas sampling probe (1).

20. The method according to the preceding claim, wherein the diluent gas is added to the exhaust gas sample in the exhaust gas sampling probe (1) and / or at its extraction location and / or is admixed immediately after the exhaust gas sample has been taken from an exhaust gas stream.

21. The method according to any one of the preceding claims, wherein the diluent gas is added to the exhaust gas sample in a mixing chamber (9) of the exhaust gas sampling probe (1).

22. The method according to any one of the preceding claims, wherein the mixture of exhaust gas sample and diluent gas is fed to an exhaust gas analysis device and / or an exhaust gas measurement is carried out.

/ Summary