阅读说明：本技术 加热元件 (Heating element ) 是由 R·布鲁克 于 2019-01-09 设计创作，主要内容包括：本发明涉及一种加热元件(1),该加热元件用于使用欧姆电阻加热用于排气后处理的部件,其中,该加热元件(1)具有不加热端部区域(3)和加热端部区域(5),其中,这两个端部区域(3,5)被中间区域(4)隔开,其中,该中间区域(4)由隔热材料组成,以使从该加热端部区域(5)到该不加热端部区域(3)的任何热流动最小化。(The invention relates to a heating element (1) for heating a component for exhaust gas aftertreatment using ohmic resistance, wherein the heating element (1) has a non-heated end region (3) and a heated end region (5), wherein the two end regions (3, 5) are separated by a middle region (4), wherein the middle region (4) consists of a thermally insulating material in order to minimize any heat flow from the heated end region (5) to the non-heated end region (3).)

1. A heating element (1) for heating a component for exhaust gas aftertreatment using ohmic resistance, wherein the heating element (1) has a non-heated end region (3) and a heated end region (5), wherein the two end regions (3, 5) are separated by an intermediate region (4), characterized in that the intermediate region (4) is composed of a thermally insulating material to minimize any heat flow from the heated end region (5) to the non-heated end region (3).

2. Heating element (1) according to claim 1, characterized in that the heat-insulating zone (4) is made of e.g. Al₂O₃Etc. ceramic material.

3. Heating element (1) according to any one of the preceding claims, characterized in that the heating element (1) has a channel-type guide (7) through the non-heated end region (3) and the intermediate region (4) into the heated end region (5), through which channel-type guide an electrical conductor (6) passes.

4. Heating element (1) according to one of the preceding claims, characterized in that the insulating material forming the intermediate region (4) has both a thermally insulating and an electrically insulating design.

5. Heating element (1) according to any of the preceding claims, characterized in that the output of heat from the heating end region (5) to the environment takes place only in the radial direction of the heating element (1) and in the axial direction away from the intermediate region (4).

6. A component (2) for exhaust gas aftertreatment, having a heating element (1) according to one of the preceding claims, characterized in that the heating element (1) has, on its unheated end region (3), assembly means (8) by means of which it can be fixed on a housing of the component (2) for exhaust gas aftertreatment.

7. Component (2) for exhaust gas aftertreatment having a heating element according to one of the preceding claims, characterized in that the component (2) for exhaust gas aftertreatment is formed by a metallic honeycomb body (2) having a hollow into which the heating element (1) can be inserted.

Technical Field

The invention relates to a heating element for heating a component for exhaust gas aftertreatment using ohmic resistance, wherein the heating element has a non-heated end region and a heated end region, wherein the two end regions are separated by an intermediate region.

Background

Conductors through which current flows and which generate heat by using ohmic resistors are known for heating components for exhaust gas aftertreatment. In particular, the prior art includes "heating cartridges", which are often of cylindrical design and have conductors inside through which an electric current flows.

Disclosure of Invention

The problem addressed by the present invention is therefore to provide a heating element which allows selective heating of components for exhaust gas aftertreatment and thus helps to minimize heat losses.

With regard to the heating element, this problem is solved by means of a heating element having the features of claim 1.

An exemplary embodiment of the invention relates to a heating element for heating a component for exhaust gas aftertreatment using ohmic resistance, wherein the heating element has a non-heated end region and a heated end region, wherein the two end regions are separated by a middle region, wherein the middle region is composed of a thermally insulating material to minimize any heat flow from the heated end region to the non-heated end region.

The thermally insulated intermediate region serves to minimize the heat flow from the heated end regions to the unheated end regions and, in a particularly advantageous embodiment, to prevent this heat flow completely. The object is thus to prevent the heat generated by the heating element from flowing unused to the unheated side of the heating element and from there radiating into the environment or unintentionally heating surrounding components. These surrounding components may include, for example, a housing of a honeycomb body into which the heating element is inserted.

Ideally, the heating element radiates the heat generated by it directly and exclusively into the structure to be heated (e.g., a honeycomb body). In this way, unintentional heat losses are avoided and thus the structure to be heated is heated more efficiently.

The heating element may have a housing in which an insulating material is arranged. In an alternative embodiment, the heating element can also be made entirely of an insulating material in the intermediate region.

It is particularly advantageous if the thermally insulating region consists of, for example, Al₂O₃Etc. ceramic material. Ceramic materials are advantageous because they can be easily adapted to the respective shape requirements and very good thermal insulation can be achieved.

It is also advantageous if the heating element has a channel-type guide through the unheated end region and the intermediate region into the heated end region, through which channel-type guide an electrical conductor passes. Inside the unheated and intermediate zones, said zones ideally have channel-type guides in order to guide an electrical conductor into the heated zone, through which an electrical current flows for heating purposes. By virtue of the guidance of the electrical conductor in the interior of the heating element, a particularly compact configuration of the heating element can be achieved. At the same time, the electrical conductor is protected from damage.

A preferred exemplary embodiment is characterized in that the insulating material forming the intermediate region has both a thermally insulating and an electrically insulating design. By virtue of the additional property of the intermediate region also having electrically insulating properties, it can be ensured that the heating element is also electrically insulated with respect to the surrounding structure (for example the housing of the honeycomb body) to which it can be fixed at the unheated end region by means of the assembly means. Thus, short circuits and energy losses due to misdirected currents can be avoided.

Preferably, the electrical conductor is electrically insulated with respect to the rest of the heating element in the interior of the heating element. This applies at least to the region where the electrical conductor passes through the unheated end region. This is intended to avoid short-circuiting with unheated end regions and thus also with surrounding structures.

It is also preferred that the output of heat from the heating end region to the environment occurs only in the radial direction of the heating element and in the axial direction away from the intermediate region.

This is advantageous because all the heat generated is thus transferred to the structure that should actually be heated. Heat dissipation to unheated end regions can be prevented or minimized to the greatest extent by the thermal insulator in the intermediate region. For example, if the heating elements are arranged in a metal honeycomb body, the main purpose is to heat the metal foils forming the flow channels, so that in particular the region of the honeycomb body through which the catalytic conversion of the exhaust gas should take place is heated.

In addition, it is advantageous if the heating element has assembly means on its unheated end region, by means of which the heating element can be fastened to a housing of a component for exhaust gas aftertreatment. This is advantageous because the connection between the heating element and the structure surrounding the heating element (for example the housing of the honeycomb body) thus takes place at a location where only very little or no heat flow takes place. Thus, heat loss can be minimized.

Furthermore, it is advantageous if the component for exhaust gas aftertreatment is formed by a metal honeycomb body which has a hollow (hollow) into which the heating element can be inserted. The metallic honeycomb body preferably consists of a plurality of smooth and profiled metal foils which are stacked on top of one another and wound. By means of the heating element inserted into the hollow, the metal foils can be heated in a particularly simple and direct manner, thus ensuring a rapid and efficient heating of the honeycomb body.

Advantageous developments of the invention are described in the dependent claims and in the following description of the figures.

Drawings

The invention will be discussed in detail below on the basis of exemplary embodiments and with reference to the figures. In the drawings:

fig. 1 shows a schematic cross section through a heating element according to the invention.

Detailed Description

Fig. 1 shows a schematic cross section through a heating element 1, which is inserted into a honeycomb body 2. Here, only the honeycomb body 2 is shown by way of indication, wherein in particular the metal foils forming the honeycomb structure are not shown.

The heating element 1 has three zones. The outer unheated end regions 3, the intermediate region 4, and the heated end regions 5. The intermediate region 4 is formed from a thermally and electrically insulating material, as a result of which the heat generated in the heated end regions 5 can flow only in very small amounts, if at all, to the unheated end regions 3.

The heating end region 5 is heated by a conductor 6 through which an electric current flows. The conductor 6 through which the current flows also passes through the unheated end regions 3 and the intermediate region 4 in a channel-type configuration 7. Ideally, the conductor 6 through which the current flows is electrically insulated with respect to the unheated end region 3.

The heating element 1 is fixed to the housing of the honeycomb body 2 by means of a flange 8. Thus, no path is formed through which the heat generated by the heating element 1 can flow directly into the housing of the honeycomb body 2. Heat is discharged from the heating end region 5 in a substantially radial direction to the honeycomb body 2 or to flow channels (not shown) of the honeycomb body 2. Furthermore, heat can be dissipated into the honeycomb body 2 in the axial direction of the heating element 1 remote from the heat-insulated intermediate region 4.

The insulating properties of the intermediate zone 4 interrupt the heat path from the heated end zone 5 to the unheated end zone 3.

In fig. 1, the heating element 1 is shown as a cylindrical body. However, this is only one possible illustrative embodiment. Other geometries that characterize the present invention are also possible.

The exemplary embodiment of fig. 1 is not particularly limiting in nature and serves to illustrate the concepts of the present invention.