Burner body, gas burner, heater and use and method for burning hydrogen fuel gas

Abstract

To significantly improve the combustion of a fuel gas containing at least 95 vol% hydrogen in a gas burner (10) for heating purposes, a burner body (16) for the gas burner (10) has been proposed, which, as a burner surface (38) for the passage of a premixed fuel gas-air mixture into a combustion chamber (14), has a perforated metal surface (40) which has through-holes (48) such that less than 5% of the burner surface (38) is open, wherein the through-holes (48) have hole diameters D with 0.4 mm ≤ D ≤ 1.0 mm, wherein the hole diameters D and / or hole lengths of the through-holes vary.

Description

[0001] The invention relates to a burner body for a gas burner for the combustion of a fuel gas containing at least 95% hydrogen by volume. The invention further relates to a gas burner with such a burner body. The invention further relates to a heating appliance with such a gas burner or such a burner body. The invention further relates to the use of a burner body or a gas burner or heating appliance equipped therewith for the combustion of a fuel gas containing at least 95% hydrogen by volume. Finally, the invention relates to a method for the combustion of such a fuel gas.

[0002] The invention lies in the field of burners for heating systems, heaters and heating appliances for heating and hot water production in buildings or the like.

[0003] For technological background, reference is made to the following literature, which reveals currently available heating appliances on the market designed as gas boilers: [1] "Gas condensing boiler WTC-GW 15 / 25 / 32-B (1.9 to 25 kW)", company brochure of Max Weishaupt GmbH, downloaded from the Internet on 25.06.2024 at https: / / www.weishaupt.de / uploads / tx_weishaupt_documents / documents / 8 3217601.pdf [2] Website https: / / www.weishaupt.de / produkte / heizsysteme-fuer-gasoel / weishaupt-thermo-condens-wtc-gw-15-25-32-kw#tab-21 1-0 / ; Downloaded on 25.06.2024 [3] "Installation and operating instructions for gas condensing boiler WTC-GW 15 ... 32-B" )", company brochure of Max Weishaupt GmbH, downloaded from the Internet on 25.06.2024 at https: / / www.weishaupt.de / uploads / tx_weishaupt_documents / documents / 8 3307201.pdf

[0004] To achieve climate targets, greenhouse gas emissions must be significantly reduced in the building sector as well. Hydrogen combustion is therefore a current topic, particularly in heating systems. While admixtures of a few percent hydrogen by volume (e.g., up to 20%) to conventional fuel gases such as natural gas are technically feasible in many gas boilers, larger hydrogen proportions, up to 100%, result in significant differences in hydrogen's combustion and reaction behavior compared to natural gas. One factor that frequently leads to problems is hydrogen's high tendency towards thermoacoustic reactions, such as pulsing, droning, whistling, and instabilities.

[0005] The invention aims to significantly improve the combustion of a fuel gas containing at least 95% hydrogen by volume for heating purposes.

[0006] To solve this problem, the invention provides a burner body according to claim 1. A burner provided therewith, a heating device provided therewith, uses of the preceding units and a method for combustion are the subject of the dependent claims.

[0007] Advantageous embodiments are the subject of the dependent claims.

[0008] According to one aspect of the invention, a burner body for a gas burner for the combustion of a fuel gas containing at least 95% hydrogen by volume is provided, wherein the burner body, as the burner surface for the passage of a premixed fuel gas-air mixture into a combustion chamber, has a perforated metal surface which has through-holes such that less than 5% of the burner surface is open, wherein the through-holes have hole diameters D of 0.4 mm ≤ D ≤ 1.0 mm, wherein the hole diameters D and / or hole lengths of the through-holes vary.

[0009] In some embodiments, it is provided that adjacent through holes have the same hole diameter D but different hole lengths.

[0010] In some embodiments, several through holes are arranged in a row, with the hole lengths varying along the row.

[0011] In some embodiments, the hole lengths increase linearly within the series of through holes. In some embodiments, the hole lengths decrease linearly within the series of through holes. In some embodiments, there is initially a linear increase in hole lengths followed by a linear decrease in hole lengths within the series of through holes. In some embodiments, there is initially a linear decrease in hole lengths followed by a linear increase in hole lengths within the series of through holes.

[0012] In some embodiments, the following applies to the hole spacing d measured between the centers of adjacent through holes: 1.4*D ≤ d ≤ 5*D. In particular, 1.4*D ≤ d ≤ 4*D applies. 1.4*D ≤ d ≤ 3*D is particularly preferred.

[0013] In some embodiments, the burner body is provided to be a metal burner plate whose main surfaces are flat and parallel to each other in non-perforated areas.

[0014] In some embodiments, the through-holes are arranged in groups of holes that are spaced apart from each other by non-perforated areas. In other words, the burner body has perforated areas in which a group of through-holes, particularly in a predetermined arrangement, is provided, and non-perforated areas between the groups of holes.

[0015] In some embodiments, the hole groups have an arrangement of X times Y through holes, where X ≥ 2 and Y ≥ 2. In preferred embodiments, 2 ≤ X ≤ 8, in particular 3 ≤ X ≤ 6, and 2 ≤ Y ≤ yso / d, where y BO is the extent of the effective burner surface in the direction of Y. Preferably, 3 ≤ Y ≤ 100.

[0016] In some embodiments, the hole groups have a circular or elliptical arrangement of the through holes.

[0017] The through-holes in the individual hole groups are preferably arranged in a square or rectangular pattern. In particular, the hole groups are arranged elongatedly (especially Y > X or Y >> X; in other words, an elongated arrangement of through-holes in each hole group). Preferably, several elongated hole groups are spaced apart from one another and distributed over the burner surface or a portion thereof. For example, the burner body may have 3 to 50 hole groups, in particular 3 to 20 hole groups, extending over a large part of the burner surface in one direction (Y-direction) and equidistant from one another in a transverse direction (X-direction).

[0018] In some embodiments, the groups of holes are each formed on a wall area which is thinned out by a recess or a recess on the side facing away from the combustion chamber compared to the non-perforated surrounding wall areas of the burner body.

[0019] In some embodiments, the adjacent through-holes with different hole lengths are provided to end on one side of the burner body at a surface inclined at an angle relative to the burner surface.

[0020] In some embodiments, it is provided that the adjacent through holes with different hole lengths open into a recess or a recess on the side facing away from the combustion chamber, the base of which is inclined or conical or roof-shaped or wedge-shaped or with at least one protrusion directed away from the combustion chamber.

[0021] In some embodiments, the adjacent through-holes with different hole lengths are designed to extend at an angle to the burner surface.

[0022] In some embodiments, it is provided that a variation of the hole length is directed in the direction in which a resonance frequency excitation propagates during the operation of a burner equipped with the burner body.

[0023] According to a further aspect, the invention relates to a gas burner for the combustion of a fuel gas which contains at least 95 vol% hydrogen, comprising a mixing device for mixing the fuel gas with air to form a fuel gas-air mixture and a burner body according to one of the preceding embodiments for directing the fuel gas-air mixture into a combustion chamber.

[0024] According to another aspect, the invention provides a heating device with such a gas burner and / or with a burner body according to one of the preceding embodiments.

[0025] According to another aspect, the invention provides for the use of a burner body according to one of the preceding embodiments for the combustion of a fuel gas which contains at least 95 vol% hydrogen.

[0026] According to another aspect, the invention provides for the use of a gas burner with a burner body according to one of the preceding embodiments for the combustion of a fuel gas which contains at least 95 vol% hydrogen.

[0027] According to another aspect, the invention provides for the use of a heating device according to one of the preceding embodiments for the combustion of a fuel gas which contains at least 95 vol% hydrogen.

[0028] According to another aspect, the invention provides a method for the combustion of a fuel gas containing at least 95% hydrogen by volume, comprising: a) Providing a burner body according to one of the preceding embodiments, b) Mixing the fuel gas with air to form a fuel gas-air mixture and c) Directing the fuel gas-air mixture through the burner body into a combustion chamber to generate a flame there.

[0029] In some embodiments, step a) includes the following steps: a1) Determining a vibration mode or natural mode of the resonance frequency of a combustion chamber in which the combustion is to take place and its direction of propagation and a2) providing the burner body such that the diameter D and / or the hole length varies along the determined direction of propagation.

[0030] In some embodiments, step a2) contains the following steps: a2.1 Arranging the through-holes in groups of holes and a2.2 Designing the through-holes such that the hole length in each group of holes increases or decreases along the direction of propagation, in particular linearly.

[0031] Some aspects, effects and technical advantages of particularly preferred embodiments of the invention are explained in more detail below.

[0032] Aspects of the invention relate to devices for hydrogen combustion in heating systems. Particularly at higher proportions, up to 100%, the differences in combustion and reaction behavior compared to natural gas become significant. One factor that frequently leads to problems is the high tendency towards thermoacoustic reactions (pulsing, droning, instabilities). Advantageous embodiments of the invention demonstrate approaches that solve this problem.

[0033] Some designs are used in gas burners for heating systems.

[0034] In particular, some embodiments relate to a device in a burner with an application in a heating appliance (gas appliance), as well as such a burner and such a heating appliance. The burner is designed for the combustion of pure hydrogen or gaseous fuels with a hydrogen content of at least 95% by volume plus admixtures of inert and other combustible gases or odorants (hereinafter referred to as fuel gas).

[0035] Embodiments of the invention have the particular advantage of improving the flame stability for hydrogen.

[0036] In preferred embodiments, the fuel gas / air mixture is supplied to a burner surface completely or partially premixed.

[0037] In some embodiments, a significant part of the burner – a burner body on which the burner surface is formed – consists of a perforated metal surface (less than 5.0% of the burner surface open).

[0038] In some embodiments, the burner surface is planar. In other embodiments, the burner surface is three-dimensionally curved. For example, in some embodiments, the burner body is cylindrical or has a semi-circular shape, like a methane radiant burner.

[0039] The burner surface is primarily made of metal, preferably aluminum. Materials with high thermal conductivity result in lower burner temperatures, which significantly improves resistance to flashback (especially boundary layer flashback).

[0040] When hydrogen is burned with air or other fuel gases with high volumetric proportions of hydrogen, resonance frequencies of the combustion chamber (longitudinal, transverse or radial) can be excited due to the significantly higher flame speed of pure hydrogen.

[0041] These thermoacoustic phenomena can occur throughout the entire modulation and permissible equivalence range of the burner.

[0042] The excitation of resonance frequencies can be promoted by unsteady heat release during the combustion of fuel gas / air mixtures.

[0043] The induction of unsteady heat release can be triggered by fluctuations in the mixture quality / fuel concentration (composition of fuel gas and oxidizer) as well as by changes in the pressure, temperature or velocity field on the unburned side of the burner.

[0044] When a flow of fluid approaches a group of holes with identical geometric dimensions (diameter, hole length), the combustion process theoretically results in an almost simultaneous reaction of the surrounding flames. The mixture, with a specific composition and state, enters and exits the group of holes almost simultaneously to be oxidized. Such a situation can have a beneficial effect on thermoacoustic excitation.

[0045] Preferred embodiments of the invention relate to an approach for damping the system: In order to dampen the system, the phase shift between fluctuating fluctuations and unsteady heat release is changed by a local change in the convective timescale.

[0046] This can be achieved through variations in the arrangement or design of the holes in the burner body. For example, different hole lengths lead to a phase shift in the fluctuation parameters that flow into the holes simultaneously and in situ. This can result in a time-delayed effect on the reaction rate and heat release of the individual flames, thus dampening the acoustic behavior.

[0047] The different hole lengths also lead to a variation in pressure loss, which changes the mass flow through the individual holes depending on their length. This affects the flame shape and can additionally lead to an improvement in thermoacoustic behavior.

[0048] The holes with different hole lengths are arranged with a sufficiently small distance between them so that the individual premixed flames have a decisive influence on each other.

[0049] Varying the hole lengths can be achieved through various design approaches. The following examples illustrate these approaches.

[0050] On one side of the burner body, which is designed, for example, as a burner plate, the fuel gas / air mixture flows onto it and is burned on the other side.

[0051] The exemplary embodiments described in more detail below with reference to the figures can vary in diameter, hole length, hole inclination, and geometric design. In some embodiments, the hole spacing d also varies within a predetermined range. Furthermore, these examples are not exhaustive.

[0052] Globally speaking, the hole groups can all be oriented in one direction or against each other, or in a mirror image.

[0053] The orientation of the hole length variation or other variation is preferably in the direction of the excited resonance frequency (concept: wave-breaking).

[0054] The holes can be clustered. A cluster is defined, for example, by X times Y holes, where X and Y are at least 2. Circular or other formations are also conceivable.

[0055] The holes may be chamfered or rounded on the unburned side to minimize pressure loss on the surface.

[0056] To improve the flame stability of lean hydrogen-air combustion, very small hole diameters D are used. For example, D is 0.4 mm to 0.8 mm or down to 1 mm.

[0057] The burner surface facing the combustion chamber is particularly preferably flat. The burner surface is particularly preferably free of protrusions or depressions. In particular, the wall of the burner body has a substantially constant thickness. Only in the perforated areas, which constitute a small portion of the burner surface and where clusters of holes are located, is a thinning formed in some embodiments by means of depressions on the side facing away from the combustion chamber, where the wall thickness is further varied, particularly to vary hole lengths.

[0058] In exemplary embodiments of the invention, there is no periodic variation. Preferably, the variation is linear. A triangular cross-section of the recess is particularly preferred, such that the hole length initially decreases from one side of the cross-section to the other, then increases again.

[0059] Examples of implementation are explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 is an exploded view showing a burner for a heating appliance; Fig. 2 is a perspective view of the burner of Fig. 1 in the assembled state; Fig. 3 another perspective view of the burner; Fig. 4 a top view of a first embodiment of a burner body of the burner of Figs. 1 to 3 ; Fig. 5 a sectional view along line AA of Fig. 4 ; Fig. 6 an enlarged view of detail B of Fig 5 ; Fig. 7 an enlarged view of detail C of Fig 4; Fig. 8 a perspective view of the burner body of the Figs. 4 to 7 according to the first embodiment; Fig. 9 a top view of a second embodiment of the burner body of the burner of Figs. 1 to 3 ; Fig. 10 a sectional view along line AA of Fig. 9 ; Fig. 11 an enlarged view of detail B of Fig 9 ; Fig. 12 an enlarged view of detail C of Fig 9 ; Fig. 13 a perspective view of the burner body of the Figs. 9 to 12 according to the second embodiment; Fig. 14 a top view of a third embodiment of the burner body of the burner of Figs. 1 to 3 ; Fig. 15 a sectional view along line AA of Fig. 14 ; Fig. 16 an enlarged view of detail B of Fig 15 ; Fig. 17 a perspective view of the burner body of the Figs. 14 to 16according to the third embodiment; Figs. 18 to 21 each show an enlarged view of a further variant of detail B, wherein the geometry shown here is used in further embodiments of the burner body instead of the one shown in the Fig. 6 , 11 or 16 The geometries shown are present.

[0060] In Figs. 1 to 3 A gas burner 10 for a heating appliance is shown, as is known from references [1] to [3], except for the special features explained below. Further details of the heating appliance are therefore not discussed here, but reference is made to [1] to [3]. The heating appliance has a suitably defined combustion chamber 14.

[0061] The gas burner 10 according to the Figs. 1 to 3 is designed for the combustion of a fuel gas which contains at least 95% hydrogen by volume.

[0062] In the illustrated embodiment, the gas burner 10 has a burner body 16 through which the fuel gas - here as a fuel gas-air mixture - enters the combustion chamber 14, a burner seal 18, fasteners 20 - for example screws 22 - for a pre-distribution plate 24, the pre-distribution plate 24, a mixture distributor 28 designed in particular as a burner hood 26, a seal 30 for the burner hood 26 and a gas-air compound as a mixing device 32 (below and with applied gas valve 34).

[0063] Details of different embodiments of the burner body 16 are described in the Figs. 4 to 21 shown which is referenced in the following description.

[0064] In the illustrated embodiments, the burner body 16 is designed as a flat burner plate 36. In the illustrated embodiments, the burner body 16 is in particular a burner plate 36 made of metal, the main surfaces 38, 40 of which are flat and parallel to each other in non-perforated areas 42.

[0065] In other embodiments not shown here, the burner body 16 can also be curved, for example as a half-cylindrical or cylindrical shell. Even in curved embodiments, the main surfaces 38, 42 are preferably parallel to each other.

[0066] In other words, the burner body 16 has a wall 44 with a constant wall thickness in the non-perforated areas.

[0067] The burner body 16 has a perforated metal surface 46 as its burner surface 38 for the passage of the premixed fuel gas-air mixture into the combustion chamber 14. Through holes 48 are provided in the wall 44 of the burner body 16, and thus in the metal surface 40, such that less than 5% of the burner surface 38 is open.

[0068] The through holes 48 have hole diameters D with 0.4 mm ≤ D ≤ 1.0 mm.

[0069] To dampen resonance frequency excitations and to stabilize the flames during the combustion of the hydrogen fuel gas, the hole diameters D and / or the hole lengths of the through holes 48 of the burner body 16 are varied in order to change the phase shift between fluctuating fluctuation quantities and unsteady heat release by locally changing the convective timescale.

[0070] While in other embodiments, not shown in detail here, local changes are achieved by varying the hole diameter D, in the illustrated embodiments, adjacent through holes 48 have the same hole diameter D but different hole lengths. In other words, the local changes are implemented by varying the hole lengths. Furthermore, although variations in the hole spacing d are also provided in other embodiments, the hole spacing d is always the same in the illustrated embodiments. The hole spacing d measured between the centers of adjacent through holes 48 lies in the range between 1.4*D and 5*D.

[0071] In the illustrated embodiments, the through holes 48 are clustered. In particular, the through holes 48 are arranged in groups 50 on perforated areas 52, which are spaced apart from each other by non-perforated areas 42.

[0072] Various arrangements of the through-holes 48 within the hole groups 50 are possible. For example, the hole groups 50 can have a circular or elliptical outline in plan view. In the illustrated embodiments, each hole group 50 is an arrangement of X through-holes 48 in a first direction (x-direction) of the burner surface 38 and of Y through-holes 48 in the other direction of the burner surface 38 (y-direction), where X and Y are natural numbers greater than or equal to 2. Accordingly, these hole groups are square or rectangular in plan view. Preferably, several identical hole groups 50 are provided, spaced apart from each other by a predetermined distance, so that the hole groups 50 are distributed over the burner surface 38. The non-perforated areas 42 are provided between the hole groups 50.

[0073] In the perforated areas 52, where the hole groups 50 are arranged, the wall 44 of the burner body 16 is thinned. For this purpose, a recess 56 or depression is provided in each of these areas 52 on the side 54 facing away from the combustion chamber.

[0074] The following refers to the Figs. 1 to 8 A first embodiment of the burner body 16 is explained in more detail. The burner body 16 of this embodiment is designed as a rectangular burner plate 36, as seen in plan view of the main surfaces 38, 40, which has a longer extent in the x-direction than in the y-direction. One of the main propagation directions of resonant frequencies is the x-direction.

[0075] The hole groups 50 are elongated and extend in the Y direction. Y is significantly larger than X. In the illustrated embodiment, X = 3. The hole diameter D is 0.6 mm, and the through holes have a center-to-center spacing d of 1.2 mm.

[0076] The recesses 56 on the side 54 facing away from the combustion chamber are correspondingly elongated and extend in the y-direction. The recesses 56 are rounded at their short ends when viewed from above.

[0077] How to especially the Fig. 5 and 6As can be seen, the recesses 56 have a roof-shaped cross-section with a triangular cross-sectional area, so that a triangular groove is formed at the bottom of the recess 56. As a result, the hole lengths vary from one edge of the recess 56 to the other edge in the x-direction such that the hole length initially decreases linearly, is shortest in the middle, and then increases linearly again.

[0078] The hole length therefore varies in the x-direction for each group of 50 holes in such a way that it decreases linearly and then increases linearly again.

[0079] For example, three to eight, and in particular five, groups of holes are provided distributed along the x-direction.

[0080] The in the Figs. 9 to 13 The second embodiment shown has proven to be the best design for reducing unwanted thermoacoustic effects in tests.

[0081] The second embodiment essentially corresponds to the first embodiment with the first difference being that the perforated areas 52 (area of ​​the recesses 56) with the hole groups 50 have a significantly smaller distance between them (here, for example, 12.5 mm), so that they are more concentrated in the center and larger non-perforated areas 42 are formed at the edges. For example, the distance between the centers of the perforated areas is in the range of 0.05x to 0.2x, where x is the extent of the burner plate 36 in the direction of propagation of the natural vibration.

[0082] Another difference is that the hole spacing d is larger in the second embodiment than in the first embodiment.

[0083] Optimized values ​​for D, d, the spacing and number of hole groups, as well as X and Y, can easily be determined for each burner body design through simulations and experiments. In particular, the resonance frequencies of the combustion chamber 14 are determined, and the hole length and / or hole diameter are varied in the direction of propagation.

[0084] In the Figs. 14 to 17 In the illustrated embodiment, the recesses 56 are circular and the hole groups are square in outline. The base of each recess 56 is inclined with respect to the x-direction.

[0085] This causes the hole lengths to increase or decrease linearly in the x-direction.

[0086] As in Fig. 10 In the third embodiment, the through holes 48 are inclined at an angle into the wall 44. For example, they thus oppose the direction of propagation of the resonant vibration.

[0087] At the in Fig. 18 In the variant shown, the through holes are essentially inserted perpendicular to the burner surface 38.

[0088] At the in Fig. 19 In the depicted variant, the hole length is varied by the fact that the base of the recess 56 has a projection 58 extending away from the combustion chamber. In this variant, the hole lengths increase from the edge towards the center. The projection can also be wedge-shaped, and more than one through-hole per row in the x-direction can be formed in the area of ​​the projection.

[0089] Variations in hole lengths can also be achieved through other design features, e.g., structures on the combustion chamber surface as in the Figs. 20 and 21 shown, possible. However, these variants have proven to be less effective in trials than the other variants shown, so they are less preferred.

[0090] Further embodiments result from any combination of the features of the illustrated embodiments. For example, the elongated perforated areas 52 with the recesses 56 of the first or second embodiment could be configured in cross-section in the x-direction (preferably the x-direction is defined as the propagation direction of the resonant vibrations) as shown in one of the Fig. 16 , 18-21 shown. Likewise, the perforated areas 52 of the third embodiment could be in cross-section as shown. Fig. 6 or 11 be shown to be trained.

[0091] To significantly improve the combustion of a fuel gas containing at least 95 vol% hydrogen in a gas burner (10) for heating purposes, a burner body (16) for the gas burner (10) has been proposed, which, as a burner surface (38) for the passage of a premixed fuel gas-air mixture into a combustion chamber (14), has a perforated metal surface (40) which has through-holes (48) such that less than 5% of the burner surface (38) is open, wherein the through-holes (48) have hole diameters D with 0.4 mm ≤ D ≤ 1.0 mm, wherein the hole diameters D and / or hole lengths of the through-holes vary. Reference symbol list:

[0092] 10 Gas burner 14 Combustion chamber 16 Burner body 18 Burner gasket 20 Fastener 22 Screw 24 Pre-dilution plate 26 Burner cover 28 Mixing distributor 30 Gasket 32 ​​Mixing device 34 Gas valve 36 Burner plate 38 Burner surface (main surface facing the combustion chamber) 40 Main surface on the side facing away from the combustion chamber 42 Non-perforated area 44 Wall 46 Perforated metal surface 48 Through hole 50 Hole group 52 Perforated area 54 Side facing away from the combustion chamber 56 Recess 58 Raise

Claims

1. Burner body (16) for a gas burner (10) for the combustion of a fuel gas containing at least 95 vol% hydrogen, wherein the burner body (16) as a burner surface (38) for the passage of a premixed fuel gas-air mixture into a combustion chamber (14) has a perforated metal surface (40) which has through holes (48) such that less than 5% of the burner surface (38) is open, wherein the through holes (48) have hole diameters D with 0.4 mm ≤ D ≤ 1.0 mm, wherein the hole diameters D and / or hole lengths of the through holes vary.

2. Burner body (16) according to claim 1, characterized by that Adjacent through holes (48) have the same hole diameter D but different hole lengths.

3. Burner body (16) according to claim 2, characterized by thatFor several through holes (48) arranged in a row, the hole lengths 3.1 increase linearly or 3.2 decrease linearly or 3.3 first decrease linearly then increase linearly or 3.4 first increase linearly and then decrease linearly.

4. Burner body (16) according to one of the preceding claims, characterized by that For the hole spacing d measured between the centers of adjacent through holes (48) the following applies: 1.4*D ≤ d ≤ 5*D.

5. Burner body (16) according to one of the preceding claims, characterized by that the burner body (16) is a burner plate (36) made of metal, the main surfaces (38, 40) of which are flat and parallel to each other in non-perforated areas (42).

6. Burner body (16) according to one of the preceding claims, characterized by that the through holes (48) are arranged in groups of holes (50) which are spaced apart from each other by non-perforated areas (42).

7. Burner body (16) according to claim 6, characterized by that the hole groups (50) 7.1 have an arrangement of X times Y through holes (48), wherein X ≥ 2 and Y ≥ 2, and / or 7.2 have a circular or elliptical arrangement of the through holes (48), and / or 7.3 are arranged elongatedly and, wherein several elongated hole groups (50) are spaced apart from each other over the burner surface (38) or a part of the burner surface (38), and / or 7.4 are each formed on a wall area which is thinned by a recess (56) or a recess on the side (54) facing away from the combustion chamber (14) compared to non-perforated surrounding wall areas of the burner body (16).

8. Burner body (16) according to claim 2 or according to one of claims 3 to 7, insofar as related to claim 2, characterized by thatthe respective adjacent through-holes (48) with different hole lengths 8.1 terminate on one side (54) of the burner body (16) at a surface inclined at an angle relative to the burner surface (38); and / or 8.2 open into a recess (56) or a recess on the side (54) facing away from the combustion chamber, the base of which is inclined at an angle or is conical or roof-shaped or wedge-shaped or has at least one projection (58) directed away from the combustion chamber (14); and / or 8.3 extend inclined at an angle to the burner surface (38).

9. Burner body (16) according to claim 2 or 8 or according to one of claims 3 to 7, insofar as related to claim 2, characterized by that a variation of the hole length is directed in the direction in which a resonance frequency excitation propagates during the operation of a gas burner (10) equipped with the burner body (18).

10. Gas burner (10) for the combustion of a fuel gas which contains at least 95 vol% hydrogen, comprising a mixing device (32) for mixing the fuel gas with air to form a fuel gas-air mixture and a burner body (16) according to one of the preceding claims for directing the fuel gas-air mixture into a combustion chamber (14).

11. Heating appliance with a gas burner (10) according to claim 10 and / or a burner body (16) according to one of claims 1 to 9.

12. Use of a burner body (16) according to any one of claims 1 to 9, a gas burner (10) according to claim 10 or a heating device according to claim 11 for the combustion of a fuel gas which contains at least 95 vol% hydrogen.

13. Method for the combustion of a fuel gas containing at least 95 vol% hydrogen, comprising: a) providing a burner body (16) according to any one of claims 1 to 9, b) mixing the fuel gas with air to form a fuel gas-air mixture and c) directing the fuel gas-air mixture through the burner body (16) into a combustion chamber (14) to generate a flame there.

14. Method according to claim 13, characterized by that Step a) includes: a1) determining a vibration mode or natural mode of the resonance frequency of the combustion chamber and the direction of propagation and a2) providing the burner body (16) such that the diameter D and / or the hole length varies along the determined direction of propagation.

15. Method according to claim 14, characterized by thatStep a2) comprises: a2.1 Arranging the through-holes (48) in groups of holes and a2.2 Forming the through-holes (48) such that the hole length in each group of holes increases and / or decreases along the direction of propagation, in particular linearly.

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