The disclosure relates to a burner for a mobile, fuel-operated heating device, in particular for a vehicle heating device, and to a mobile, fuel-operated heating device, in particular for a vehicle heating device, and to a method for manufacturing a burner.
Burners, in particular evaporator burners, are used in particular in independent vehicle heaters and/or auxiliary heaters, especially for vehicles, that are operated with liquid fuel. In such evaporator burners, liquid fuel is fed into an evaporator via a fuel supply line. Metal fiber fleeces, for example, can be used as the evaporator itself. The evaporator soaks up liquid fuel, in particular by capillary action, and distributes liquid fuel. By means of the heat provided by a glow plug or ignition element, liquid fuel is vaporized and ignited so that combustion of the fuel can take place when air is supplied. Air supply openings are arranged in a circumferential wall for this purpose. Such an arrangement is known, for example, from DE 10 2018 111 636 A1.
According to the prior art, an evaporator burner is known from DE 10 2005 032 980 B4, which comprises a combustion chamber housing in which an evaporator medium is accommodated in a bowl-like carrier. A fuel supply line is accommodated in the bottom region of the combustion chamber housing. The combustion chamber housing has a circumferential wall which is provided with exactly one row of air supply openings arranged in the circumferential direction. The air supply openings each have a radial extension direction, i.e. parallel to a circumferential wall normal. Such a perforation of the combustion chamber has the disadvantage that fuel and air are distributed inhomogeneously in the combustion chamber and thus combustion proceeds in an undefined manner in the sense of an ideal combustion process characterized by a complete and low-emission combustion. Soot formation and greatly increased NOx emissions can occur in this process. Usually, the distribution of air and fuel and thus the combustion can be improved by an empirical design of the ventilation.
Another combustion chamber assembly is known from DE 10 2012 211 932 B3. This combustion chamber assembly has a plurality of combustion air inlet openings, of which at least one of the combustion air inlet openings has a opening longitudinal axis which is inclined with respect to a surface normal of the circumferential wall in the region of the combustion air inlet opening. The combustion air inlet openings may be arranged in a plurality of rows. In this case, the combustion air inlet openings of different rows can have different inclination angles of the opening longitudinal axes. In particular, the combustion air inlet opening is inclined to such an extent that no residual radial opening is present with respect to a view in the direction of the surface normal. At a high inclination angle greater than 40°, the penetration depth in particular is insufficient.
Another heating device for a burner operated with liquid fuel is known from DE 30 10 078 A1. The heating device has a low-pressure atomizer. The heating device has oblique swirl openings in a circumferential wall.
It is an object of the disclosure to disclose an improved burner for a mobile fuel-operated heating device and a mobile fuel-operated heating device, as well as a method for manufacturing an evaporator receiving body.
The object of the disclosure is solved with respect to the burner by the features of claim 1, with respect to the heating device by the features of claim 12, with respect to the method by the features of claim 13. Suitable embodiments result from the respective dependent claims.
The burner according to the disclosure for a mobile fuel-operated heating device, in particular for a vehicle heating device, comprises
The first opening longitudinal axis forms a first angle relative to a circumferential wall normal of the first air supply opening. The second opening longitudinal axis forms a second angle (differing from the first angle, in particular differing in magnitude from the first angle) relative to a circumferential wall normal of the second air supply opening.
In this case, the first angle and the second angle are preferably selected such that the first inlet surface overlaps at least partially with the first outlet surface and the second inlet surface overlaps at least partially with the second outlet surface in the projection direction of the circumferential wall normal. If one looks in the circumferential normal direction at an air supply opening, a continuous opening can preferably be seen at least in sections. Thus, at least two different air supply openings are arranged in the row. Such an arrangement has the advantage that a spin, a penetration depth and thus also the mixing of combustion air and fuel are considerably improved. The combustion proceeds in a more defined manner and emissions of nitrogen oxides can be reduced.
In one embodiment, the air supply openings are arranged along at least two, in particular two to four, rows in the circumferential direction of the circumferential wall, wherein each row comprises at least a first air supply opening and a second air supply opening.
In an expedient embodiment, the first angle and the second angle are at most 40°, preferably 7° to 35°, more preferably 8° to 30°.
Alternatively, exclusively the first angle may be 0°. With a first angle of 0°, the first opening longitudinal axis is aligned parallel to the circumferential wall normal.
The first angle and/or the second angle may lie in a plane spanned by the circumferential wall normal and a circumferential direction (at the location of the respective air supply opening). Alternatively or additionally, the first angle and/or the second angle can lie in a (respective) plane spanned by the respective row.
In embodiments, the first angle and/or the second angle may lie in a plane spanned by the circumferential wall normal (at the location of the respective air supply opening) and a central axis of the circumferential wall. In particular, the first angle and/or the second angle may lie in a plane spanned by the circumferential normal (at the location of the respective air supply opening) and a perpendicular to a plane spanned by the respective row.
Alternatively, the first angle and/or the second angle may be oblique to a plane (respectively the above) spanned by the circumferential wall normal and a circumferential direction at the location of the respective air supply opening. Alternatively or additionally, the first angle and/or the second angle may be oblique to a plane spanned by the respective row (of air supply openings).
In one embodiment, the air supply openings further comprise third air supply openings or third and fourth air supply openings having a third angle and optionally fourth angle different from the first angle and the second angle. The air supply openings may include a plurality of air supply openings each having a different angle. Even though in principle each air supply opening may have an angle different from all other air supply openings, the precise design of the burner, e.g. by means of flow simulation, may be costly.
In an expedient embodiment, air supply openings adjacent at least in the circumferential direction, in particular air supply openings adjacent in all directions, are air supply openings with different angles. This is achieved, for example, by an arrangement in which first and second air supply openings alternate. The next row can then start with an offset.
In particular, the air supply openings may be arranged along the circumferential direction in a periodic pattern, where in particular all rows of air supply openings have the same pattern. For example, such a pattern may be A-B-A-B; A-B-C-A-B-C, A-AB-B-A-A-B-B, A-A-B-A-A-B, A-B-C-B-A-B-C.
Further, the air supply openings may be arranged axisymmetrically with respect to the central axis of the circumferential wall.
Expediently, the air supply openings are equally spaced along the circumferential direction. In this case, only the air supply openings of a respective row can be at the same distance from one another or all rows can be at the same distance from one another.
In one embodiment, the thickness of the circumferential wall may differ at least in the region of part of the air supply openings from the thickness of the remaining circumferential wall. This may, for example, be a local thickening of the circumferential wall in the region of one, several or all of the air supply openings.
In one embodiment, the circumferential wall is arranged at an evaporator receiving body. Such an evaporator receiving body expediently has a bottom region. Advantageously, the circumferential wall extends from the bottom region. The fuel supply line may open into the bottom region of the evaporator receiving body.
The mobile heating device according to the disclosure, in particular mobile vehicle heating device, comprises a burner according to the disclosure. Such a heating device is particularly suitable for use in land vehicles.
The method according to the disclosure for manufacturing a burner, preferably a burner, in particular the above burner, comprises:
In particular, flow simulations and heat distribution simulations can be used to arrange the first and second air supply openings. For the insertion of the air supply openings, the openings may be drilled or milled, for example, or may be manufactured with the burner, in particular the evaporator receiving body, in a casting manner.
The disclosure is also explained in more detail below with respect to further features and advantages by means of the description of embodiment examples and with reference to the accompanying drawings. It shows in each case in a principle drawing:
A circumferential wall 8 extends from the bottom region 6. The circumferential wall is cylindrical in sections and conical in sections. An exclusively cylindrical design is also possible as an alternative. In a lower section of the circumferential wall, i.e. close to the bottom region 6, a receiving element 10 is arranged, which is suitable for receiving an ignition element and/or a flame guard. The height of the receiving element 10, measured from the bottom region, is in particular adapted to the size of the evaporator assembly.
A plurality of air supply openings 12 are provided in the circumferential wall 8. In the example shown, the air supply openings 12 are arranged in two rows 20, 22 in the circumferential direction. However, arrangement in only one row or in multiple rows is also possible. In
Here, in the row 22, first and second air supply openings 14, 15 are arranged as air supply openings, and in the row 20, third and fourth air supply openings 16, 17 are arranged as air supply openings.
The first air supply opening 14 is designed here with a first angle α1 of 0°. In this case, the circumferential wall normal, i.e. the perpendicular of the circumferential wall, in the area of the air supply opening and a first opening longitudinal axis are parallel to each other. With a cylindrical air supply opening, the first inlet surface and the first outlet surface completely overlap in projection along the circumferential wall normal.
Here, the second air supply opening 15 is formed at an angle. The second opening longitudinal axis 15a of the second air supply opening and the circumferential wall normal 8a in the region of the second air supply opening 15 are at a second angle α2 to each other. In this case, this second angle α2 lies exclusively in a plane spanned by the circumferential wall normal 8a and the circumferential direction. When the second air supply opening 15 is cylindrical, the second inlet surface 15b and the second outlet surface 15c partially overlap in projection along the circumferential wall normal 8a.
Here, the third air supply opening 16 is formed with a third angle α3 of 0°. In this case, the circumferential wall normal 8a, i.e., the perpendicular of the circumferential wall 8, in the region of the air supply opening and a third opening longitudinal axis 16a are parallel to each other. With the air supply opening being cylindrical, the third inlet surface 16b and the third outlet surface 16c completely overlap in projection along the circumferential wall normal 8a.
The fourth air supply opening 17 is formed obliquely here. The fourth opening longitudinal axis 17a of the fourth air supply opening 17b and the circumferential wall normal 8a in the region of the fourth air supply opening are at a fourth angle α4 to each other. In this case, this fourth angle α4 lies exclusively in a plane spanned by the circumferential wall normal 8a and the central axis. With the fourth air supply opening 17 being cylindrical, the fourth inlet surface 17b and the fourth outlet surface 17c partially overlap in projection along the circumferential wall normal 8a.
The second air inlet opening 15 extends obliquely. Thus, circumferential wall normal 8a and second opening longitudinal axis 15a lie one above the other at a second angle α2 to each other. The second outlet surface 15c of the second air supply opening 15 is arranged on the inner side of the circumferential wall 8, and the second inlet surface 15b is arranged on the outer side of the circumferential wall 8. The second inlet surface 15b and the second outlet surface 15c partially overlap in projection along the circumferential wall normal 8a. Thus, an opening is provided as viewed along the circumferential wall normal 8a.
The third air supply opening 16 extends obliquely. Thus, circumferential wall normal 8a and third opening longitudinal axis 16a lie one above the other at a third angle α3 with respect to each other. The third outlet surface 16c of the third air supply opening 16 is arranged on the inner side of the circumferential wall 8, and the third inlet surface 16b is arranged on the outer side of the circumferential wall 8. The third inlet surface 16b and the third outlet surface 16c partially overlap in projection along the circumferential wall normal 8a. Thus, an opening is provided in the viewing direction along the circumferential wall normal 8a.
Even though the disclosure is illustrated using the example of a burner with an evaporator receiving body, a circumferential wall with the air supply openings described above can also be arranged elsewhere in the burner, for example with a housing, as a separate component.
Number | Date | Country | Kind |
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10 2020 100 403.6 | Jan 2020 | DE | national |
This application represents the national stage entry of PCT International Patent Application No. PCT/EP2021/050066 filed on Jan. 5, 2021 and claims priority to German Patent Application No. 10 2020 100 403.6 filed Jan. 10, 2020. The contents of each of these applications are hereby incorporated by reference as if set forth in their entirety herein.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/050066 | 1/5/2021 | WO |