阅读说明：本技术 颗粒传感器和对此的制造方法 (Particle sensor and method for producing same ) 是由 R·鲁萨诺夫 U·格兰茨 于 2020-03-13 设计创作，主要内容包括：颗粒传感器,具有用于给流体流中的颗粒充电的颗粒充电装置,其中,所述颗粒充电装置具有用于产生电晕放电的至少一个电晕电极,其中,颗粒传感器具有带表面的载体元件,并且,其中,所述至少一个电晕电极构造为平坦的元件并且布置在所述载体元件的表面上。(Particle sensor having a particle charging device for charging particles in a fluid flow, wherein the particle charging device has at least one corona electrode for generating a corona discharge, wherein the particle sensor has a carrier element with a surface, and wherein the at least one corona electrode is configured as a flat element and is arranged on the surface of the carrier element.)

1. A particle sensor (100) having a particle charging device (110) for charging particles (P) in a fluid flow (A1), wherein the particle charging device (110) has at least one corona electrode (112; 112 ') for generating a corona discharge (113), wherein the particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) has a carrier element (102) with a surface (102a), and wherein the at least one corona electrode (112; 112') is configured as a flat element and is arranged on the surface (102a) of the carrier element (102).

2. A particle sensor (100; 100 a; 100 b; 100 c; 100D; 100e) according to claim 1, wherein a maximum dimension extension (D) of the at least one corona electrode (112; 112 ') along a surface normal (102a ') of the surface (102a) of the carrier element (102) is smaller than a maximum dimension extension (L, B) of the at least one corona electrode (112; 112 ') in a virtual plane corresponding to the surface (102a) of the carrier element (102).

3. A particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) according to at least one of the preceding claims, wherein the at least one corona electrode (112; 112') is applied, in particular printed, in particular by means of a screen printing method, onto the surface (102a) of the carrier element (102).

4. Particle sensor (100; 100 a; 100B; 100 c; 100 d; 100e) according to at least one of the preceding claims, wherein a length (L) of the corona electrode (112; 112 ') in the surface (102a) of the carrier element (102) along a first coordinate axis (x) is larger, in particular at least ten times larger, than a width (B) of the corona electrode (112; 112') in the surface (102a) of the carrier element (102) along a second coordinate axis perpendicular to the first coordinate axis.

5. Particle sensor according to at least one of the preceding claims(100; 100 a; 100 b; 100 c; 100 d; 100e), wherein the corona electrode (112; 112 ') or at least one electrode tip (112_1) of the corona electrode (112; 112') has and/or consists of at least one of the following elements or a mixture of a plurality of the following elements: platinum, platinum alloys, iridium alloys, noble metals like platinum, ceramic materials, especially alumina, Al₂O₃。

6. Particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) according to at least one of the preceding claims, wherein the particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) has at least one trap electrode (120) for deflecting charged particles of the fluid flow (A1) and/or at least one sensor electrode (130) for sensing information about charged particles (P ') in the fluid flow (A1), wherein the at least one trap electrode (120) and/or the at least one sensor electrode (130) are arranged on the same surface (102a) of the carrier element (102), in particular with the at least one corona electrode (112; 112').

7. Particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) according to at least one of the preceding claims, wherein a plurality of corona electrodes (112, 112 ') are provided, wherein in particular a first corona electrode (112) is arranged on a first surface (102a) of the carrier element (102) and a second corona electrode (112') is arranged on a second surface (102b) of the carrier element (102).

8. Particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) according to at least one of the preceding claims, wherein the carrier element (102) consists of a ceramic material, in particular a thin-film ceramic, wherein in particular at least one electrode (112, 112', 114, 120, 130) and/or at least one supply lead (112_2) for the at least one electrode is configured as a screen-printed element, and/or wherein in particular at least one supply lead (112_2) for the corona electrode (112) and/or at least one Passivation (PAS) of at least one region (EB2) is configured as a screen-printed element.

9. Particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) according to at least one of the preceding claims, wherein an axial end region (EB2) of the at least one corona electrode (112; 112') is provided

a) With an electrically insulating Passivation (PAS), and/or

b) Is a round-off shape and is provided with a round-off shape,

wherein in particular the rounded end region (EB2) has a convex region (112_3) with a radius of curvature which is greater than 50% of the width (B) of the corona electrode (112; 112').

10. Method for producing a particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) having a particle charging device (110) for charging particles in a fluid flow, wherein the particle charging device (110) has at least one corona electrode (112; 112') for generating a corona discharge (113), wherein the particle sensor (100; 100 a; 100 b; 100 c; 100 d; 100e) has a carrier element (102) with a surface (102a), wherein the method has: the at least one corona electrode (112; 112 ') is configured (200) as a flat element, and the at least one corona electrode (112; 112') is arranged (202) on the surface (102a) of the carrier element (102).

11. Method according to claim 10, wherein a maximum dimensional extension (D) of the at least one corona electrode (112; 112 ') along a surface normal (102 a') of the surface (102a) of the carrier element (102) is smaller than a maximum dimensional extension (L, B) of the corona electrode (112) in a virtual plane corresponding to the surface (102a) of the carrier element (102).

12. Method according to at least one of claims 10 to 11, wherein the at least one corona electrode (112; 112') is applied, in particular printed, in particular by means of a screen printing method, onto the surface (102a) of the carrier element (102).

Technical Field

The present disclosure relates to a particle sensor having a particle charging device for charging particles in a fluid flow.

The present disclosure also relates to a method for manufacturing such a particle sensor.

Disclosure of Invention

A preferred embodiment relates to a particle sensor having a particle charging device for charging particles in a fluid flow, wherein the particle charging device has at least one corona electrode for generating a corona discharge, wherein the particle sensor has a carrier element with a surface, and wherein the at least one corona electrode is configured as a flat element and is arranged on the surface of the carrier element. This enables a simple and cost-effective construction and at the same time a high lifetime, since the flat corona electrode degrades, in particular burns out, relatively slowly according to the applicant's research.

The fluid flow may be, for example, an exhaust gas flow of an internal combustion engine. The particles can be, for example, carbon black particles, which are produced, for example, in the frame of combustion of fuel by an internal combustion engine. The principles according to embodiments may be used for sensing both particles formed as solids (e.g., soot particles, which are for example contained in the exhaust stream of an internal combustion engine) and, for example, liquid particles (e.g., aerosols).

In a further preferred embodiment, it is provided that the at least one corona electrode is printed onto the surface of the carrier element, in particular by means of a screen printing method.

In a further preferred embodiment, it is provided that the length of the corona electrodes in the surface of the carrier element along a first coordinate axis is greater, in particular significantly greater, than the width of the corona electrodes in the surface of the carrier element along a second coordinate axis perpendicular to the first coordinate axis (length for example greater than five times the width).

In a further preferred embodiment, it is provided that the at least one corona electrode or at least one electrode tip of the at least one corona electrode has and/or is composed of or made of at least one of the following elements or a mixture of a plurality of the following elements: platinum, platinum alloys, iridium alloys, noble metals like platinum, ceramic materials, especially alumina (Al)₂O₃) Composite materials (cermets) made of ceramic materials in a metal matrix, in particular cermet pastes (more particularly ceramic-stabilised noble metal pastes).

In a further preferred embodiment, it is provided that the particle sensor has at least one trap electrode for deflecting and/or collecting charged particles (e.g. free charge carriers, such as ions) of the fluid flow and/or at least one sensor electrode for sensing information about charged particles in the fluid flow, wherein the at least one trap electrode and/or the at least one sensor electrode are arranged on the same surface of the carrier element, in particular with the at least one corona electrode.

In a further preferred embodiment, it is provided that a plurality of corona electrodes are provided, wherein in particular a first corona electrode is arranged on a first surface of the carrier element and a second corona electrode is arranged on a second surface of the carrier element, wherein the second surface is preferably different from the first surface.

In a further preferred embodiment, it is provided that the carrier element consists of a preferably highly insulating ceramic material, in particular a ceramic film, wherein the at least one electrode and/or the at least one supply line for the at least one electrode are particularly preferably designed as a screen-printing element, and/or wherein the at least one supply line for the electrode and/or the at least one passivation of the at least one region (for example the axial end region of the corona electrode) are preferably designed as a screen-printing element.

In a further preferred embodiment, it is provided that the axial end region of the at least one corona electrode has an electrically insulating passivation.

In a further preferred embodiment, it is provided that the axial end region of the at least one corona electrode is rounded, wherein the rounded end region has, in particular, a convex region with a radius of curvature which is greater than 50% of the width of the corona electrode.

In a further preferred embodiment, it is provided that the axial end region of the at least one corona electrode has an electrically insulating passivation and is rounded at the same time, wherein the rounded end region has, in particular, a convex region with a radius of curvature which is greater than 50% of the width of the corona electrode.

A further preferred embodiment relates to a method for producing a particle sensor having a particle charging device for charging particles in a fluid flow, wherein the particle charging device has at least one corona electrode for generating a corona discharge, wherein the particle sensor has a carrier element with a surface, wherein the method has: the at least one corona electrode is configured as a planar element and is arranged on a surface of the carrier element.

In a further preferred embodiment, it is provided that a maximum dimensional extent of the at least one corona electrode along a surface normal of the surface of the carrier element is smaller than a maximum dimensional extent of the at least one corona electrode in a virtual plane corresponding to the surface of the carrier element.

In a further preferred embodiment, it is provided that the at least one corona electrode is printed, particularly preferably by means of a screen printing method, onto the surface of the carrier element.

Drawings

Further features, application possibilities and advantages of the invention result from the following description of an exemplary embodiment of the invention which is illustrated in the drawing. All described or illustrated features form the subject matter of the invention per se or in any combination, independently of their combination in the claims or their cited relation, and independently of their presentation in the description and in the drawings.

In the drawings:

figure 1 schematically shows a side view of a particle sensor according to a preferred embodiment,

figure 2 schematically shows the arrangement of the particle sensor according to figure 1 in a target system,

figure 3A schematically shows in partial cross-section a side view of a particle sensor according to a further preferred embodiment,

figure 3B schematically shows a top view of the particle sensor according to figure 3A,

figure 4 schematically shows a side view of a particle sensor according to a further preferred embodiment,

figure 5 schematically shows in partial cross-section a side view of a particle sensor according to a further preferred embodiment,

figure 6 schematically shows a top view of a particle sensor according to a further preferred embodiment,

FIG. 7 schematically shows a top view of a particle sensor according to a further preferred embodiment, an

Fig. 8 schematically shows a simplified flow chart of a method according to a further preferred embodiment.

Detailed Description

Fig. 1 schematically shows a particle sensor 100 according to a preferred embodiment. The particle sensor has a particle charging device 110 for charging particles P in the fluid flow a1, thereby obtaining charged particles P'. The particle charging device 110 has at least one corona electrode 112 for generating a corona discharge 113.

In addition, the particle sensor 100 has a carrier element 102 with a first surface 102 a. Preferably, the corona electrode 112 is configured as a flat element (e.g., in the form of a "flat wire") and is arranged on the first surface 102a of the carrier element 102. This enables a simple and cost-effective construction and at the same time a high lifetime, since the flat corona electrode 112 degrades, in particular burns out, relatively slowly according to the research of the applicant. If the electrode tip 112_1 of the corona electrode 112 degrades (for example due to material ablation of the electrode tip 112_1), then in a further preferred embodiment the next "wire" section of the corona electrode 112 is used as a (new) electrode tip, which increases the service life.

Fluid stream a1 may be, for example, the exhaust stream of an internal combustion engine. The particles P may be, for example, carbon black particles and/or further solid and/or droplet-like particles, which are produced, for example, in the framework of the combustion of fuel by an internal combustion engine. The principle according to the exemplary embodiment can be used both for detecting particles P formed as solids (e.g. soot particles, which are contained, for example, in the exhaust gas flow a1 of an internal combustion engine) and for detecting, for example, liquid particles (e.g. aerosols).

In a further preferred embodiment, it is provided that the corona electrodes 112 are printed or applied, in particular by means of a screen printing method, onto the surface 102a of the carrier element 102.

In a further preferred embodiment, it is provided that the length L of the corona electrodes 112 along the first coordinate axis x in the surface 102a of the carrier element 102 (or parallel to this surface) is greater, in particular significantly greater, than the width of the corona electrodes 112 along a second coordinate axis perpendicular to the first coordinate axis x (perpendicular to the plane of the drawing in fig. 1) in the surface 102a of the carrier element 102 (length L preferably greater than five times the width).

In a further preferred embodiment, it is provided that the corona electrode 112 or at least one electrode tip 112_1 of the corona electrode 112 has at least one of the following elementsAn element and/or a mixture of at least one or more of the following elements: platinum, platinum alloys, iridium alloys, noble metals like platinum (especially in terms of physical and/or chemical properties), ceramic materials, especially alumina (Al)₂O₃)。

In a further preferred embodiment, it is provided that the particle sensor 100 has at least one optional trap electrode 120 for deflecting charged particles, in particular ions, of the fluid flow and/or at least one optional sensor electrode 130 for sensing information about charged particles P' in the fluid flow a1, wherein the at least one trap electrode 120 and/or the at least one sensor electrode 130 are arranged, in particular, on the same (first) surface 102a of the carrier element 102 as the at least one corona electrode 112.

In a further preferred embodiment, a plurality of corona electrodes 112, 112 'are provided, wherein, in particular, a first corona electrode 112 is arranged on the first surface 102a of the carrier element 102 and a second corona electrode 112' is arranged on the second surface 102b of the carrier element 102.

In a further preferred embodiment, an optional counter electrode 114 for the corona electrode 112 and/or the optional trap electrode 120 is provided, which counter electrode can be charged, for example, with a reference potential, such as ground potential.

In a further preferred embodiment, the particle sensor 100 is configured for sensing information about the charged particles P' by means of the principle of induction. Here, the charged particles P' moving past the sensor electrode 130 generate a signal in the sensor electrode 130, which can be evaluated in a known manner. Lighter charged particles, such as ions (for example, charging particles P), which are also produced by corona discharge 113, can be captured or collected, for example, by optional trap electrode 120 before they reach sensor electrode 130 and thus influence the charge measurement on the particles in an undesirable manner.

In a further preferred embodiment, the particle sensor 100 is configured for sensing information about the charged particles P' by means of the escape current principle. To this end, the entire system containing the particle sensor 100 can be ionized to the outside (whereby in particular the counter electrode 114 for the corona electrode 112 and the optional counter electrode 114 for the optional trap electrode 120, if present, can be "virtual", for example a virtual ground electrode), and the current is measured, which is carried away from the electrically insulating and thus closed system by the charged particles P' in the form of their charging. The observed current flows, for example, from the at least one corona electrode 112, 112' through the corona discharge 113 into the corresponding electrode 114 of the corona electrode, and the remaining ions are captured by the optional trap electrode 120. The current generated by the charged particles P' must in turn be supplied to the counter electrode 114, whereby the potential of said counter electrode remains constant. This current is called the "escape current" and is a measure for the concentration of charged particles P'.

In a further preferred embodiment, it is provided that the carrier element 102 (fig. 1) consists of a ceramic material, in particular a thin-film ceramic, wherein the at least one electrode 112, 112', 114, 120, 130 and/or the at least one supply line for the at least one electrode are particularly preferably designed as a screen-printed element and/or wherein the at least one passivation for the at least one supply line is particularly preferably designed as a screen-printed element.

Fig. 2 schematically shows the arrangement of the particle sensor 100 according to fig. 1 in a target system Z, which is here, for example, an exhaust system of an internal combustion engine of a motor vehicle. Here, the exhaust gas flow is designated with reference character a 2. Likewise, a protective tube assembly 1000 is shown, which consists of two tubes R1, R2 arranged coaxially with respect to one another, wherein the particle sensor 100 is arranged in the inner tube R1 in such a way that the first surface 102a of the carrier element 102 (fig. 1) runs substantially parallel to the longitudinal axis LA of the inner tube R1. In a further preferred embodiment, owing to the different lengths of the tubes R1, R2 and the arrangement relative to one another, a swirl is generated by the venturi effect in which the exhaust gas flow a2 causes a fluid flow P1 or a1, which emerges from the inner tube R1 and is directed upwards in fig. 2 in the vertical direction. The further arrows P2, P3, P4 indicate the continuation of this fluid flow caused by the venturi effect through the intermediate space between the two tubes R1, R2 to the surroundings of the protective tube assembly 1000. Overall, the arrangement illustrated in fig. 2 results in a comparatively uniform flow through the particle sensor 100 or its first surface 110a oriented along the fluid flow P1 (in particular in the sense of laminar flow), which enables an efficient sensing of particles located in the fluid flows a1, P1. Furthermore, the particulate sensor 100 is protected from direct contact with the primary exhaust flow a 2.

The reference sign R2 'indicates an optional electrical connection of the outer tube R2 and/or the inner tube R1 to a reference potential, such as ground potential, so that the relevant tube or both tubes can advantageously simultaneously serve as counter electrodes, for example for the at least one corona electrode 112, 112' (fig. 1) and/or the optional trap electrode 120, for its fluid-guiding function (for example instead of the optional counter electrode 114, fig. 1).

In fig. 2, block arrows P5 symbolize an optional fresh gas supply, in particular a fresh air supply, which may be desired in some embodiments, but which is not provided in particularly preferred embodiments.

Fig. 3A schematically shows in partial cross-section a side view of a particle sensor 100a according to a further preferred embodiment. Fig. 3B schematically shows a top view of the particle sensor 100a according to fig. 3A. Here, the inner tube R1 (see also fig. 2) forms a counter electrode for the corona electrode 112. As can be seen from the top view according to fig. 3B, the length L of the corona electrode 112 measured along the horizontal coordinate axis x in fig. 3B is four times greater than the width B measured along the vertical coordinate axis y in fig. 3B. Thus, the corona electrode 112 has, for example, a substantially elongated shape, similar to a "flat wire". Particularly preferably, corona electrodes 112 are designed as flat elements following the principle according to the embodiment, so that thickness D (see also fig. 1) measured perpendicular to the drawing plane in fig. 3B is likewise significantly smaller than length L. In a further preferred embodiment, the thickness D results, for example, from the manufacturing process used for the corona electrode 112, for example, from a screen printing method. In a further preferred embodiment, the width B is greater than the thickness D. In another preferred embodiment, the width B (fig. 3B) is, for example, at least ten times greater than the thickness D.

Fig. 4 schematically shows a side view of a particle sensor 100b according to a further preferred embodiment. In this configuration, the tube R1 is also provided as a counter electrode for the corona electrode 112, and the corona discharge 113 is formed at the electrode tip 112_ 1. Further downstream an optional trap electrode 120 is provided and further downstream an optional sensor electrode 130 is provided.

Fig. 5 schematically shows a side view of a particle sensor 100c according to a further preferred embodiment. Configuration 100c according to fig. 5 has two corona electrodes 112, 112 ', wherein a first corona electrode 112 is arranged on first surface 102a (see also fig. 1) and a second corona electrode 112' is arranged on second surface 102b of carrier element 102. In a further preferred embodiment, at least one optional trap electrode 120 is provided, which is preferably configured as a buried electrode and is thus not arranged on one of the surfaces 102a, 102b, but rather inside the carrier element 102. In a further preferred embodiment, at least one optional sensor electrode 130 is provided, which is configured as a buried electrode and is thus not arranged on one of the surfaces 102a, 102b, but rather inside the carrier element 102. In a further preferred embodiment, alternatively or additionally, at least one optional trap electrode 120 and/or an optional sensor electrode 130 may be provided on at least one or both of the surfaces 102a, 102b, respectively. In the particle sensor 100c according to fig. 5, the exhaust gas flow a1 can be charged particularly effectively above and below the carrier element 102 by means of two corona electrodes 112, 112 '(see respective corona discharges 113, 113').

Fig. 6 schematically shows a top view of a particle sensor 100d according to a further preferred embodiment. A corona electrode 112, which is configured as a flat element and has an electrode tip 112_1, is arranged on the carrier element 102. Here, the electrode tip 112_1 is also flat, for example in the shape of a triangle, while the remaining corona electrode 112 has, for example, a substantially rectangular basic shape with a length L and a width B, see fig. 3B. Fig. 6 also shows a supply line 112_2 for the corona electrodes 112, by means of which the corona electrodes 112 can be charged to a predefinable potential to generate a corona discharge 113 (fig. 1). Likewise, an optional trap electrode 120 and an optional sensor electrode 130 are provided in the particle sensor 100d according to fig. 6. The carrier element 102 is arranged inside a first tube R1 which in turn advantageously forms a counter electrode for the corona electrode 112. For this purpose, the tube R1 can be charged, for example, with a predeterminable reference potential, such as ground potential.

Fig. 7 schematically shows a top view of a particle sensor 100e according to a further preferred embodiment. A corona electrode 112 is shown, for example, having substantially the shape of a "flat wire". In the axial end region EB1 of the corona electrode on the left in fig. 7, the corona electrode 112 is connected to the supply line 112_ 2. In the right-hand axial end region EB2 of the corona electrode in fig. 7, the corona electrode 112 has an electrically insulating passivation PAS which preferably completely covers the right-hand axial end region EB2 of the corona electrode 112, so that no corona discharge can take place in this region EB2, since an excessively high electric field in this region is prevented by the passivation PAS. In this embodiment, a substantially elongate corona discharge 113 along the flat corona electrode 112, i.e. between the axial end regions EB1, EB2, is thus advantageously produced. This advantageously reduces the local load on corona electrode 112 (e.g., compared to the concentration of corona discharge 113 at electrode tip 112_1), and increases the service life.

In a further preferred embodiment, it is provided that an axial end region of the corona electrode 112, here the axial end region EB2 on the right in fig. 7, is rounded, see reference numeral 112_3, wherein the rounded end region 112_3 has, in particular, a convex region with a radius of curvature which is preferably greater than 50% of the width B of the corona electrode 112, more preferably greater than 250% of the width B of the corona electrode 112.

In a further preferred embodiment, it is provided that the axial end region EB2 of the at least one corona electrode 112 has an electrically insulating passivation PAS and is at the same time rounded, as is illustrated here by way of example in fig. 7.

A further preferred embodiment relates to a method for producing a particle sensor according to the embodiment, having a particle charging device for charging particles in a fluid flow, wherein the particle charging device has at least one corona electrode for generating a corona discharge, wherein the particle sensor has a carrier element with a surface, wherein the method has: the at least one corona electrode is configured as a planar element and is arranged on a surface of the carrier element.

In this regard, fig. 8 schematically illustrates a simplified flow diagram of the method. In step 200, the at least one corona electrode 112 (fig. 1) is designed as a flat element, for example in the form of a flat display, for example in the form of a flat wire, for example printed, and in step 202 (fig. 8), the at least one corona electrode 112 is arranged on the surface 102a of the carrier element 102. In a further preferred embodiment, steps 200, 202 can also be carried out substantially simultaneously, for example, by arranging the at least one corona electrode 112 on the surface 102a of the carrier element 102, for example by means of a screen printing method. In a further preferred embodiment, the configuration 200 or arrangement 202 may also comprise a configuration 200 or arrangement 202 of at least two corona electrodes 112, 112'.