WO2024074626A1

WO2024074626A1 - Heating element

Info

Publication number: WO2024074626A1
Application number: PCT/EP2023/077602
Authority: WO
Inventors: Mykola Konopinsky
Original assignee: Tenneco Gmbh
Priority date: 2022-10-05
Filing date: 2023-10-05
Publication date: 2024-04-11
Also published as: DE102022125694A1

Abstract

The invention relates to a heating element (1) for heating a gas stream with a heating resistor (2) and with two contacts (3.1, 3.2) for applying an electrical voltage, wherein the heating resistor (2) has at least one current conductor (2a) with a length (2f) and a longitudinal axis (2b), which extends over its length (2f) between the two contacts (3.1, 3.2), wherein the longitudinal axis (2b) represents a main flow direction 2.0 of the electric current, wherein at least three current conductor sections (2.1, 2.2, 2.3) are provided, wherein all at least three current conductor sections (2.1, 2.2, 2.3) form a common heating plane_H1 formed with respect to the longitudinal axis (2b), wherein at least two of the at least three current conductor sections (2.1, 2.2, 2.3) are arranged adjacent to one another with respect to a direction at right angles to the longitudinal axis 2b and delimit a gap 2c, wherein at least one current conductor section of the at least three current conductor sections (2.1, 2.2, 2.3) is formed as bridge_1 and bridges the gap (2c), wherein at least three further current conductor sections (2.4, 2.5, 2.6) are provided, which form a common second heating plane_H2 with respect to the longitudinal axis (2b), which is arranged at a distance_e from the first heating plane_H1, wherein at least one current conductor section is provided, that is formed as bridge_2 and that bridges the distance_e.

Description

Heating element

The invention relates to a heating element for heating a gas stream with a heating resistor and with two contacts for applying an electrical voltage, wherein the heating resistor has at least one current conductor with a length and a longitudinal axis, which extends over its length between the two contacts, wherein the longitudinal axis represents a main flow direction of the electrical current, wherein at least three current conductor sections are provided, wherein all at least three current conductor sections form a common heating plane_H1 with respect to the longitudinal axis, wherein at least two of the at least three current conductor sections are arranged next to one another with respect to a direction perpendicular to the longitudinal axis and delimit a gap, wherein at least one current conductor section of the at least three current conductor sections is designed as a bridge and bridges the gap.

The invention also relates to a spacer for a heating element.

A heating element is already known from US 5,533,167 B with several current conductor sections and connecting bridges, with all bridges being arranged parallel to the heating plane or at right angles to the respective gap plane. The bridges are somewhat narrower than the heating element itself.

A heating element with several conductor sections and connecting bridges is also known from KR 2005 008 7202 A. According to the embodiment in Figure 1a, all bridges are arranged parallel to the heating plane or at right angles to the respective gap plane. According to the embodiment in Figure 1b, all bridges are aligned at right angles to the heating plane. The spiral-shaped heating element designated as the state of the art has a central bridge that is aligned parallel to the heating plane.

The invention is based on the object of designing and arranging a heating element in such a way that an improved heat input is ensured. The object is achieved according to the invention in that at least three further conductor sections are provided, which form at least one common second heating level_H2 with respect to the longitudinal axis, which is arranged at a distance_e from the first heating level_H1, wherein at least one conductor section is provided which is designed as a bridge and which bridges the distance_e. This ensures that a three-dimensional extension of the conductor sections and several parallel heating levels are provided.

The conductor sections within a heating level_H1 are spaced apart from one another, forming a gap. The focus is on the conductive part of the conductor section; any insulation or insulating spacers are to be ignored. The various conductor sections are only connected by the end bridge. The bridge therefore forms the essential part of a connecting loop between various conductor sections. The length of the heating resistor corresponds to the extent of its longitudinal axis.

By connecting several bridges in a row, a more complex redirection can be achieved within several heating levels. The number of heating levels is optional.

The current conductor is made of electrically conductive material that is in the form of a honeycomb, mesh, net or fabric structure. The orientation of part of the honeycomb walls or honeycomb, mesh, net or fabric wires deviates from the main flow direction of the current.

The object is also achieved according to the invention in that at least one first crossbar and at least one second crossbar are provided, which can be aligned parallel to the groove plane, the first crossbar being arranged opposite the second crossbar with respect to the base body. The crossbars are arranged on both sides of the base body, so that the crossbars can be placed in opposite columns of opposite heating levels. It can also be advantageous if the respective heating level_H1, _H2 has a front side facing the gas flow to be heated and has a base area, the first heating level_H1 and the at least second heating level__H2 defining a groove over at least 70% of the base area, the bridge bridging the groove. The heating level_H1 and the heating level_H2 are thus electrically coupled via the respective bridge. The base area is formed by all the current conductor sections arranged next to one another within the respective heating level. This includes the bridges. However, the groove does not extend over the bridges, so that only part of the base area is defined by the groove, whereas the remaining part of the base area is assigned to the bridges.

Furthermore, it can be advantageous if the groove spans a groove plane and opposite gaps of adjacent heating planes_H1, __H2 span a gap plane, wherein the groove plane encloses an angle a of between 10° and 90° relative to the gap plane. As a rule, the angle a is 90° because the several heating planes arranged parallel to one another extend in the direction of the exhaust gas flow, thus in a direction perpendicular to the respective heating plane itself.

It can also be advantageous if the respective bridge has a central axis, whereby the central axis runs parallel to the heating level_H1, _H2 or at a right angle to the heating level_H1, _H2. The parallel alignment to the heating level_H1 ensures that the gap between the conductor sections is bridged. The right-angled alignment to the heating level_H1 or to the heating level_H2 ensures that the groove between the two heating levels_H1, _H2 is bridged.

It can be advantageously provided that, using a Cartesian coordinate system with three spatial axes_x, _y, _z, the heating plane_H1 is aligned parallel to the xy plane and the bridge_1 extends at least partially in the direction of the spatial axis_x with reference to the central axis for bridging the gap and the bridge_2 extends at least partially in the direction of the spatial axis_x with reference to the central axis for bridging the groove. axis_z. The exhaust gas flow runs in the direction of the spatial axis_z. If the base area G has a round shape according to the exhaust pipe, the bridges on the outer edge are also simply curved, with only one axis of curvature parallel to the spatial axis_z. In this respect, the bridges are not flat and cannot be assigned to any plane. The bridge_1 extends in the direction of the spatial axis_x to bridge the gap in the xy plane, regardless of its width. The bridge_2 extends in the direction of the spatial axis_z to bridge the groove in the xy plane, regardless of its width.

It can be of particular importance for the present invention if the main flow direction of the electric current can be guided alternately over the heating level_H1 and the heating level_H2. With this symmetrical voltage supply, the heating level_H1 facing the exhaust gas flow will be somewhat colder than the one downstream due to the impacting exhaust gas flow. The heating level_H2 lying in the exhaust gas shadow is exposed to somewhat warmer exhaust gas. The temperature difference between the heating level_H2 and the already heated exhaust gas flow emerging from the heating level_J-11 is thus favored.

In connection with the design and arrangement according to the invention, it can be advantageous if the base body extends in the direction of the x-axis and the transverse webs extend in the direction of the z-axis, wherein the base body has a maximum width which corresponds to the distance e between two heating levels_H1, _H2 and wherein the respective transverse web has a width which corresponds to the gap width. The architecture of the spacer is thus adapted to the orientation and position of the gap or groove. If the base body has a rectangular cross-section, the maximum width refers to its diagonal because the base body has to be rotated about its longitudinal axis after being inserted into the groove. If the base body has a round cross-section, the maximum width refers to its diameter.

It may also be advantageous if the distance between the crossbars corresponds to the gap width of the gap or the distance between the crossbars corresponds to twice the distance the gap. On the side of the respective gap where the bridge_1 is provided between adjacent conductor sections, no crossbar is required. In this respect, the number of crossbars can be reduced accordingly or by about half.

It can also be advantageous if the crossbars are of different lengths or have different dimensions and at least one crossbar can be positioned in the gaps of several heating levels. This can reduce the number of spacers required.

Further advantages and details of the invention are explained in the patent claims and in the description and shown in the figures. They show:

Figure 1a is a front view of the heating element;

Figure 1b is a side view of 1a;

Figure 1c is a detailed view of Fig. 1a;

Figure 2a shows the rear view of Fig. 1a;

Figure 2b shows the side view from Fig. 2a;

Figure 3a is a top view of the heating element according to Figure 1a;

Figure 3b is a view of the heating element according to Figure 1a from below;

Figure 3c shows an alternative embodiment of the heating element in a view from below;

Figure 4a shows a spacer in side view;

Figure 4b shows an alternative embodiment of the spacer;

Figure 4c is a front view of a spacer;

Figure 4d is a front view of a spacer;

Figure 4e is a front view of a spacer; Figure 5 shows a heating resistor with three heating levels.

A heating element 1 shown in Figure 1a is formed from a conductor 2a with a longitudinal axis 2b and two contacts 3.1, 3.2 for applying an electrical voltage. The conductor 2a runs in a meandering shape and has various conductor sections 2.1 to 2.6, which are arranged one behind the other and are separated from one another by a gap 2c with a gap width of 2.9, among other things. The various conductor sections 2.1 to 2.6 form a circular base area 7. The various conductor sections are connected to one another at the end via a bridge 2.4 as a further conductor section, with the respective bridge 2.4 bridging the respective gap 2c. The meandering conductor sections with the base area 7 therefore form a heating plane H1.

In the side view according to Fig. 1b, in addition to the heating level_H1 just described, a further heating level_H2 is provided, which is formed from corresponding conductor sections 2.5, 2.6. Both heating levels_H1, _H2 are connected to one another via a conductor section 2.4 designed as a bridge. Both heating levels_H1, _H2 delimit a groove 4.1 with a groove width 4.3. Gas flow 5 flowing in from the right initially enters through the first heating level_H1 and after passing through the groove 4.1 it enters through the second heating level_H2.

According to Fig. 1c, a detailed view from Fig. 1a, the current conductor 2a has a longitudinal axis 2b, which runs in a meandering manner as shown in Fig. 1a. A length of the current conductor therefore corresponds to the length of the longitudinal axis 2b. The bridge 2.2 shown serves to bridge the gap 2c. The bridge 2.2 has a longitudinal axis 2.2', which is aligned transversely to the gap 2c.

The back of the heating element 1 (Fig. 2a) is constructed in a similar way. The various current conductor sections form a meandering path, whereby the corresponding bridges 2.4 alternate between the front side shown in Fig. 1a and the back side shown in Fig. 2a. Thus, the longitudinal axis 2b or a current 2.0 runs downwards from the contact 3.1, changes there via a bridge 2.4 to the front (Fig. 1a top left) and then runs in a U-shape over two current conductor sections back up to the upper end of the current conductor section 2.3 and changes there again via a bridge 2.4 to the back and also describes an arc on the back. The respective arc is formed by two current conductor sections that are connected to one another by a bridge 2.2 and each delimit the gap 2c between them.

The groove 4.1 located between the two heating levels_H1, _H2 has a corresponding partially circular groove base, which is limited by the bridges 2.4 arranged below.

According to the embodiments shown here, both heating planes H1, H2 lie in or parallel to an x-y plane, spanned by the spatial axis x and the spatial axis y. The aforementioned groove plane 4.2 is also arranged or aligned parallel to this. The gap plane 2d, in turn, which is spanned by adjacent gaps 2c of the two heating planes H1, H2, runs at right angles to the groove plane 4.2, and thus lies in a spatial plane y-z, which is spanned by the spatial axis y and the spatial axis z.

In the view from above (Fig. 3a), the bridges 2.4 arranged next to each other can be seen, via which the two heating levels _H1, _H2 are connected to each other. Between the various bridges 2.4, the bridges 2.2 can be seen, which each bridge the gap between two current conductor sections. The bridges 2.2 are located at the lower edge of the heating element. The respective gap spans a gap level 2.d and has a gap width 2.9.

In the view from below according to Fig. 3b, the bridges 2.2 arranged next to each other to bridge the respective gap can be seen. The bridges 2.4 arranged at the top are shown within the groove 4.1, which run over the groove 4.1. The groove 4.1 spans a groove plane 4.2, whereby the groove plane 4.2 and the gap plane 2d enclose an angle a of 90°. The groove has, as shown in Fig. 1b, a groove width 4.3 which corresponds to a distance_e between the two heating planes_H1, _H2.

While in the previously described embodiment the bridges 2.2, 2.4 used between the various conductor sections alternate, in the embodiment shown in Fig. 3c a view from above or below is provided, in which a bridge 2.2 for bridging the gap is immediately connected to the bridge 2.4 for bridging the groove. A conductor section is provided between each of this double arrangement of bridges 2.2, 2.4.

To maintain the distance e between the heating levels _H1, _H2 on the one hand and to maintain the gap width 2.9, a spacer element 6 as shown in Figures 4a to 4c is provided. The spacer element has an elongated base body 6.1, to which several crosspieces 6.2, 6.3 are connected. The crosspieces 6.2, 6.3 are each provided opposite the base body 6.1 and have the gap width 2.9. The base body 6.1 has the groove width 4.3, which corresponds to the distance e between the two heating levels. By inserting the spacer 6, i.e. by inserting the base body 6.1 into the groove 4.1 on the one hand and inserting the crosspieces 6.2, 6.3 into the gap 2c on the other hand, the necessary distance between the various conductor sections is ensured.

In the embodiment according to Fig. 4b, the spacer has fewer crosspieces 6.2, 6.3. Such a spacer would be used in the area of the respective bridge 2.2 in which no crosspiece is necessary, so that only crosspieces are provided for the gaps that are not bridged by a bridge 2.2 or for the gaps at the end of which no bridge 2.2 is provided.

According to Fig. 4c, the base body 6.1 has a maximum width that corresponds to the distance e between the heating levels. One edge length of the rectangle corresponds to refers to the width of the crossbars 6.2, 6.3. This can also be constructed differently so that different widths are used.

According to the embodiment shown in Fig. 4d, the base body 6.1 has a round cross-section with a diameter corresponding to the distance e between the heating levels.

According to the embodiment shown in Fig. 4e, the crossbar 6.2 has a significantly larger extension a than the crossbar 6.3. This variant is used for a heating resistor 2 with three heating levels that delimit two grooves 4.1. Due to the extension a, the crossbar 6.2 then extends into the respective gaps 2c of two adjacent heating levels_H1,

_H1' while the crossbar 6.2 is positioned in the respective gap of the third opposite heating level_H2.

The embodiment Fig. 5 shows a heating resistor 2 with three parallel heating levels _H1, _H1', _H2.

List of reference symbols

1 heating element

2a conductor

2b Longitudinal axis

2c gap

2d cleavage plane

2f length

2 Heating resistor

2.0 Current direction, main flow direction

2.1 Conductor section

2.2 Conductor section, bridge_1

2.2‘ center axis

2.3 Conductor section

2.4 Conductor section, bridge_2

2.4' center axis

2.5 Conductor section

2.6 Conductor section

2.9 Gap width

3.1 Contact

3.2 Contact

4 Front

4.1 Groove

4.2 Groove plane

4.3 Groove width

5 Gas flow

6 spacers

6.1 Basic body

6.2 Crossbar

6.3 Crossbar

7 Base area a Extension of 6.2 e Distance nomenclature

Bridge_1 Bridge_2 Level_E1 Level_E2 Heating level H1 Heating level_H1‘ Heating level_H2 Space axis x Space axis y Space axis z x-y plane x-z plane y-z plane Angle α

Claims

Claims Heating element (1) for heating a gas flow (5) with a heating resistor (2) and with two contacts (3.1, 3.2) for applying an electrical voltage, wherein the heating resistor (2) has at least one current conductor (2a) with a length (2f) and a longitudinal axis (2b), which extends over its length (2f) between both contacts (3.1, 3.2), wherein the longitudinal axis (2b) represents a main flow direction (2.0) of the electrical current, wherein at least three current conductor sections (2.1, 2.2, 2.3) are provided, wherein all at least three current conductor sections (2.1, 2.2, 2.3) form a common heating plane H1 with respect to the longitudinal axis (2b), wherein at least two of the at least three current conductor sections (2.1, 2.2, 2.3) are arranged with respect to a direction are arranged next to one another at right angles to the longitudinal axis (2b) and delimit a gap (2c), wherein at least one conductor section of the at least three conductor sections (2.1, 2.2, 2.3) is designed as a bridge_1 (2.2) and bridges the gap (2c), characterized in that at least three further conductor sections (2.4, 2.5, 2.6) are provided which, with respect to the longitudinal axis (2b), form at least one common second heating level__H2 which is arranged at a distance_e from the first heating level_H1, wherein at least one conductor section is provided which is designed as a bridge__2 and which bridges the distance_e. Heating element (1) according to claim 1, characterized in that the respective heating level_H1, _H2 has a front side (4) facing the gas flow to be heated and having a base area (7), wherein the first heating level_H1 and the at least second heating level_H2 delimit a groove (4.1) over at least 70% of the base area (7), wherein the bridge_2 bridges the groove (4.1). Heating element (1) according to claim 2, characterized in that the groove (4.1) spans a groove plane (4.2) and that opposite gaps (2c) of adjacent heating planes_H1, _H2 span a gap plane (2d), the groove plane (4.2) enclosing an angle a of between 10° and 90° relative to the gap plane (2d). Heating element (1) according to one of the preceding claims, characterized in that the respective bridge_1, _2 has a central axis (2.2', 2.4'), the central axis running parallel to the heating plane_H1, _H2 or running at right angles to the heating plane_H1, _H2. Heating element (1) according to claim 4, characterized in that, using a Cartesian coordinate system with three spatial axes_x, _y, _z, the heating plane_H1 is aligned parallel to the xy plane and the bridge_1 extends at least partially in the direction of the spatial axis_x with reference to the central axis (2.2') to bridge the gap (2c) and the bridge_2 extends at least partially in the direction of the spatial axis_z with reference to the central axis (2.4') to bridge the groove (4.1). Heating element (1) according to one of the preceding claims, characterized in that the main flow direction (2.0) of the electrical current can be guided alternately over the heating plane_H1 and the heating plane_H2. Spacer (6) for a heating element (1) according to one of the preceding claims with a base body (6.1) which can be aligned parallel to the groove plane (4.2), characterized in that at least one first transverse web (6.2) and at least one second transverse web (6.3) are provided which can be aligned parallel to the groove plane (4.2), wherein the first transverse web (6.2) is arranged opposite the second transverse web (6.3) with respect to the base body (6.1). Spacer (6) according to claim 7, characterized in that the base body (6.1) extends in the direction of the x-axis and that the transverse webs (6.2) extend in the direction of the z-axis, the base body (6.1) having a maximum width that corresponds to the distance_e between two heating levels_H1, _H2 and the respective transverse web (6.2, 6.3) having a width that corresponds to the gap width (2.9). Spacer (6) according to claim 7 or 8, characterized in that the distance of the transverse webs (6.2) corresponds to the gap width (2.9) of the gap (2c) or that the distance of the transverse webs (6.2) corresponds to twice the distance of the gap. Spacer (6) according to one of claims 7-9, characterized in that the transverse webs (6.2, 6.3) are of different lengths and at least one transverse web (6.2) can be positioned in the gap of several heating levels. Heating element (1) according to one of claims 1 -6, characterized in that the heating resistor (2) has at least three heating levels, the heating level_H1, the heating level_H1' and the heating level_H2. System consisting of a heating element (1) according to one of claims 1-6 or 11 with at least one spacer (6) according to one of claims 7-10 arranged therein.