Burner device, heat generator, heating system and domestic water supply system

Abstract

The invention provides a burner device 100 for supplying heat energy by combustion of an air-fuel mixture, wherein the fuel B contains, in particular, hydrogen. The burner device 100 comprises a generally cylindrical flame body 1, which has an outer combustion surface 17 formed on a cylindrical shell of the flame body 1, on which the combustion of the air-fuel mixture takes place, wherein the combustion surface 17 is connected via through-openings 16 in the cylindrical shell to an interior space 11 at least partially enclosed by the flame body 1. Furthermore, the burner device 100 comprises a fuel supply device 2 arranged at least partially in the interior space 11 for introducing fuel into a mixing area 15 for mixing the fuel B with air L to form the air-fuel mixture, wherein the mixing area 15 is formed in the interior space 11 between the fuel supply device 2 and the flame body 1.and a flow channel 3 running centrally in the interior 11 along a longitudinal central axis 14 of the flame body 1 for supplying air into the mixing area 15, which is at least partially enclosed by the fuel supply device 2.

Description

Technical field

[0001] The present invention relates to a burner device, a heat generator with a burner device and a heating system as well as a domestic hot water supply system, each with a heat generator. Background of the invention

[0002] From the prior art, burner devices for use in heat generators are known in which an air-fuel mixture is premixed and then burned on a combustion surface of a flame body in order to provide heat energy for further use, for example for heating a fluid.

[0003] In such premix burners, the usually gaseous fuel and air are first supplied to a mixing area and mixed there, before the resulting air-fuel mixture is supplied to the combustion surface, from which a burner flame of the burner device extends.

[0004] Premixing offers the advantage that the composition of the air-fuel mixture can be adjusted to a desired composition for combustion upon reaching the combustion surface, in order to ensure, among other things, complete combustion of the fuel and thus a particularly high efficiency.

[0005] However, one disadvantage of this approach is that the air-fuel mixture occupies a not insignificantly small volume within the burner device before combustion, thus creating the risk of a flame flashback, in which the burner flame flashes back into the mixing area.

[0006] This can lead not only to a loss of function of the burner, but also to damage to the burner itself or surrounding structures.

[0007] To prevent at least a complete backfire through the entire mixing area, flame arresting devices are known from the prior art, including from EP 4 141 321 A1, which do not allow the backfire burner flame to pass through.

[0008] However, such flame arresting devices take up a lot of installation space and reduce the efficiency of the burner device, as they not only disrupt the mixing of air and fuel, but also introduce an additional flow resistance that must be compensated for by increasing the supply pressures of air and / or fuel.

[0009] This phenomenon of flame flashback becomes particularly critical with the recently intended use of hydrogen-containing fuel, especially in burner devices used in heating systems or domestic hot water supply systems.

[0010] Hydrogen has a higher flame propagation speed than conventionally used fossil fuels, meaning that burner devices that have previously only been operated with fossil fuels cannot simply be converted to hydrogen-containing fuel.

[0011] Specifically, the currently available burner devices are not suitable for use with hydrogen-containing fuel. Summary

[0012] The present invention is therefore based on the objective of creating a method for combustion-based heat generation and utilization that is improved compared to the prior art and allows reliable, efficient and, above all, safe operation, especially with hydrogen-containing fuels, even without the use of a flame arrestor device in the burner assembly.

[0013] To solve this problem, a burner device according to claim 1 is provided, as well as, based on this, a heat generator according to claim 13, a heating system according to claim 14 and a domestic hot water supply system according to claim 15.

[0014] The respective dependent claims relate to preferred embodiments, which can each be provided individually or in combination.

[0015] According to a first aspect of the invention, a burner device is provided for supplying heat energy by combustion of an air-fuel mixture, wherein the fuel in particular contains hydrogen. The burner device comprises a generally cylindrical flame body, which has an outer combustion surface formed on a cylindrical shell of the flame body, on which the combustion of the air-fuel mixture takes place, wherein the combustion surface is connected via through-openings in the cylindrical shell to an interior space at least partially enclosed by the flame body.Furthermore, the burner device comprises a fuel supply device arranged at least partially in the interior for introducing fuel into a mixing area for mixing the fuel with air to form an air-fuel mixture, wherein the mixing area is formed in the interior between the fuel supply device and the flame body, and a flow channel running centrally in the interior along a longitudinal central axis of the flame body for supplying air into the mixing area, which is at least partially enclosed by the fuel supply device.

[0016] Hydrogen-containing fuel is not to be understood as a fuel that merely contains hydrogen in combination with other atoms, such as hydrocarbons, but rather as actual fuels that contain a certain proportion of elemental hydrogen (H₂). Preferably, the hydrogen content is between 10 and 100 vol.%, particularly preferably between 30 and 80 vol.%. Ideally, the hydrogen content can be selected according to the application of the burner device.

[0017] The term "generally cylindrical" or simply "cylindrical" is to be understood throughout the application as referring to a general cylinder according to the standard mathematical definition, i.e., a shape resulting from the extrusion of a curve lying in a plane along a line segment not lying in said plane. A circular cylinder, in this context, denotes a specific cylinder with a circular base. The qualifier "generally" will be largely omitted in the following text.

[0018] The cylindrically shaped flame body, which is in particular a circularly cylindrical flame body, extends along its longitudinal central axis. In other words, the longitudinal central axis of the flame body is understood to be a longitudinal axis running through the center of the interior, enclosed by the cylindrical shell of the flame body, which acts as the combustion surface, with the longitudinal central axis running essentially parallel to the cylindrical shell, i.e., basically parallel to the aforementioned path along which extrusion takes place.

[0019] Preferably, the flame body is designed such that the through-openings connecting the mixing area and the combustion surface are perpendicular, in particular perpendicular, to the longitudinal center axis. Thus, the longitudinal center axis of the flame body corresponds to a center axis perpendicular to the discharge directions of the air-fuel mixture onto the combustion surface. Any radial direction of the flame body is subsequently understood to refer to said longitudinal center axis.

[0020] The inventive implementation with a flow channel running centrally within the flame body creates a possibility for transporting the air required for combustion over large areas of the flame body, whereby the air can flow unhindered along the longitudinal central axis, which is preferably also the main flow direction of the flow channel, even to more distant areas of the flame body, without mixing with the fuel.

[0021] In this way, an adequate air supply can be implemented at all points in the interior without there being too large a volume of air-fuel mixture in the interior, which significantly reduces the risk of flame flashback.

[0022] The situation is different, for example, with the burner assembly of EP 4 141 321 A1, where the air spreads continuously from one end of the interior to the other. As it does so, it increasingly mixes with the fuel, resulting in a sometimes significant fluctuation in the fuel or air ratio within the interior. Consequently, the areas of the burner assembly furthest from the air inlet of EP 4 141 321 A1 receive an insufficient supply of air, resulting in a comparatively rich mixture in these areas.

[0023] The use of the central airflow channel thus allows for an unimpeded supply of air and therefore leads to a particularly homogeneous air-fuel mixture, which in turn enables particularly efficient combustion with high efficiency.

[0024] This enables particularly stable operation with a reduced risk of flame flashback and uniform combustion with particularly high efficiency.

[0025] The feature of the surrounding fuel supply device is to be understood as meaning that it, or parts of it, do not extend into the central flow channel and would act there as flow resistances that would impede the airflow in the flow channel.

[0026] To further stabilize the airflow, the flow channel essentially has an oval or circular cross-section relative to a cross-sectional plane perpendicular to the longitudinal center axis of the flame body, into which parts of the fuel supply system do not protrude. Deviations from the aforementioned cross-sectional shapes are certainly possible.

[0027] However, the feature of enclosure does not preclude the use of an additional flow wall that is not part of the fuel supply device, as long as the flow channel is surrounded by the fuel supply device.

[0028] In a preferred embodiment, the fuel supply device, which preferably surrounds the flow channel radially with respect to the longitudinal center axis, at least partially separates the mixing area from the flow channel.

[0029] By separating it from the mixing area, the air can be directed unhindered and "unmixed" into the areas of the interior furthest from the inlet side, so that, for example, no rich mixtures are present there and the volume fraction of combustible air-fuel mixture to the total volume of the interior can be kept low.

[0030] In a preferred embodiment, with reference to a cross-sectional plane running perpendicular to the longitudinal central axis of the flame body, the ratio of a cross-sectional area of ​​the flow channel to a cross-sectional area of ​​the entire interior is greater than or equal to 20%, more preferably greater than or equal to 30% and particularly preferably greater than or equal to 50%.

[0031] In this way, a sufficiently large amount of air can be transported through the flow channel through the flame body to ensure not only sufficient air for a lean mixture throughout the entire flame body, but also to achieve a particularly homogeneous air-fuel mixture, thus minimizing fuel concentration fluctuations in the air-fuel mixture across the flame body (avoiding local over-enrichment).

[0032] Preferably, with reference to a cross-sectional plane running perpendicular to the longitudinal central axis of the flame body, the ratio of a radial distance between the fuel supply device and the flame body across the mixing area to half the diameter of the interior (corresponding to radius) is less than or equal to 40%, more preferably less than or equal to 20% and particularly preferably greater than or equal to 15%.

[0033] In this way, the mixing area occupies a comparatively small volume in the interior, so that the amount of air-fuel mixture in the interior that can be ignited by a potential flame flashback is comparatively small.

[0034] In other words, this results in a particularly short length of the mixing path for air and fuel between the fuel supply device or an outlet opening thereof and the flame body, which is particularly suitable when using hydrogen-containing fuel, as this significantly reduces the risk of flame flashback.

[0035] In a preferred embodiment, a deflection area is formed in the interior between an end section of the flame body and the fuel supply device, through which the air flowing through the flow channel can be deflected into the mixing area.

[0036] The end section is the end of the flame body that is opposite the end of the flame body where air and / or fuel are supplied (inlet end or side), across the longitudinal center axis. In other words, this corresponds to the end furthest from the inlet end.

[0037] The deflection area allows air to be supplied to the mixing area at the end furthest from the inlet end, which has the maximum distance to said inlet end, so that a lean air-fuel mixture is mixed over the entire length of the flame body.

[0038] In a preferred embodiment, the flow channel is separated from the mixing area in the radial direction of the flame body by the fuel supply device.

[0039] In this way, premature mixing of the air flowing through the flow channel with the fuel introduced into the mixing area can be reliably prevented.

[0040] In a preferred embodiment, the fuel supply device comprises a double-walled cylinder arranged at least partially in the interior, with a radially inner and a radially outer cylinder wall, between which a flow path for the fuel is formed, and wherein the radially inner cylinder wall is a flow wall of the flow channel.

[0041] This provides a comparatively simple and cost-effective way to implement a fuel supply device that simultaneously acts as a flow wall for the flow channel and completely separates it from the mixing area in the radial direction of the flame body.

[0042] The double-walled cylinder preferably has a plurality of outlet openings distributed over the radially outer cylinder wall, through which the fuel flowing between the cylinder walls is introduced into the mixing area.

[0043] In a preferred embodiment, the radially inner and / or the radially outer cylinder wall has a circular cross-sectional shape with respect to a cross-sectional plane perpendicular to the longitudinal central axis of the flame body.

[0044] Particularly with a similarly circular cylindrical flame body, a spatially uniform flow channel and mixing area can be implemented in this way.

[0045] In a preferred embodiment, the fuel supply device comprises a plurality of supply lines which are arranged spaced apart from the longitudinal central axis of the flame body around the flow channel, in particular these are arranged uniformly around the flow channel.

[0046] Preferably, the plurality of supply lines comprises between 4 and 24 supply lines, each of which may have a circular or non-circular cross-section, for example polygonal, oval or elliptical, with respect to the cross-sectional plane already mentioned several times.

[0047] In this way, the fuel supply to the mixing zone can be regulated particularly well and, above all, precisely controlled, since the flow cross-section for the fuel in a single supply line can be made comparatively small. Each supply line has a multitude of outlet openings to the mixing zone, through which the fuel is introduced.

[0048] The supply lines are arranged in particular parallel to the longitudinal center axis in order to provide a flow cross-section of the central flow channel running between the individual supply lines that remains constant over the longitudinal center axis.

[0049] With respect to the cross-sectional plane perpendicular to the longitudinal center axis, adjacent supply lines can be connected to each other in order to create a flow channel separated from the mixing area.

[0050] Preferably, adjacent supply lines are separated from each other by a distance zone, which in turn connects the central flow channel for gas transmission with the mixing zone.

[0051] In this way, between adjacent supply lines, some of the air flowing through the flow channel can flow from it into the mixing area, so that along the longitudinal central axis, air from the flow channel, in which the air flows unhindered in the main flow direction, is continuously supplied to the mixing area in order to provide sufficient air for a lean air-fuel mixture.

[0052] In a preferred embodiment, at least one, and in particular all, of the plurality of supply lines is a non-circular supply line, such that, with respect to a cross-sectional plane extending perpendicular to the longitudinal center axis of the flame body, it has a cross-sectional shape whose extent along a first principal axis is greater than its extent along a second principal axis perpendicular, and in particular perpendicular, to the first principal axis. In particular, the at least one supply line has an elliptical cross-sectional shape. Preferably, the at least one non-circular supply line of the plurality of supply lines is arranged such that the first principal axis extends in the radial direction of the flame body.

[0053] In this way, the spacing between adjacent supply lines can be increased, allowing more air to be introduced into the mixing zone along the length of the longitudinal center axis. Simultaneously, the distance between the supply lines and the flame body can be reduced, thus shortening the mixing path. This results in a lean air-fuel mixture while simultaneously reducing the risk of flame flashback.

[0054] In a preferred embodiment, the fuel supply device comprises outlet nozzles for the fuel which project radially outwards from a main surface of the fuel supply device adjacent to the mixing area in the direction of the flame body, such that the distance between the openings of the outlet nozzles and the flame body is less than the distance between the main surface and the flame body.

[0055] In this way, the distance to the flame body can be reduced without unduly reducing the mixing area, which beyond a certain point would only lead to an insufficient supply of air to provide the air-fuel mixture.

[0056] In a preferred embodiment, an outer contour of the fuel supply device adjacent to the mixing area has a groove extending along the longitudinal central axis of the flame body, within which outlet openings for the fuel are arranged.

[0057] The groove provides a recess on the fuel feed device, which at least partially shields the outlet opening from an airflow passing directly over it. This allows for controlled and uninterrupted fuel injection. Furthermore, the groove prevents any backfire from spreading throughout the entire mixing area.

[0058] The aforementioned outlet nozzles and / or the aforementioned groove can be used both in the preferred embodiment with double-walled cylinders and with the multiple supply lines of the fuel supply device.

[0059] According to a second aspect of the invention, a heat generator is provided for transferring thermal energy to a fluid, in particular for use in a heating system or in a domestic hot water supply system, wherein the heat generator comprises at least a burner device according to the first aspect or a preferred embodiment thereof, as well as a heat exchanger coupled to the burner device, via which thermal energy provided by the burner device can be transferred to the fluid.

[0060] This makes the particularly efficient and safe burner device usable for heating any fluid, which in turn can be used in numerous other systems or installations. The advantages already described for the burner device also apply to the heat generator that comprises it, which enables efficient and safe combustion, especially in the case of hydrogen-containing fuel. This, in the case of the heat generator, is synonymous with efficient and safe heating of the fluid in question.

[0061] For example, the heat exchanger can be a surface, finned or spiral heat exchanger.

[0062] According to a third aspect of the invention, a heating system for heating a building is provided, comprising at least a piping system for transporting a fluid energy transport medium and a heat generator according to the second aspect of the invention, which is equipped to heat the energy transport medium to be transported through the piping system.

[0063] According to a fourth aspect of the invention, a domestic water supply system is provided for supplying domestic water, comprising at least a piping system for transporting the domestic water and a heat generator according to the second aspect of the invention, which is equipped to heat the domestic water to be transported through the piping system.

[0064] By using the heat generator according to the invention as part of a heating system and / or a domestic hot water supply system of a building, the advantages already described of safe and efficient combustion, in particular of hydrogen-containing fuel, can be implemented in the area of ​​heating as well as in the area of ​​hot water supply. Fig. 1 shows a perspective view of the burner device according to the invention. Fig. 2A and 2B show sectional views of a first embodiment of the burner device according to the invention. Fig. 3A and 3B The diagrams show sectional views of a second embodiment of the burner device according to the invention with different cross-sectional profiles of supply lines in Fig. 3C . Fig. 4 shows a section in the area of ​​a fuel outlet into the mixing area of ​​a third embodiment of the burner device according to the invention. Fig. 5Ashows a section in the area of ​​a fuel outlet into the mixing area of ​​a fourth embodiment of the burner device according to the invention with a further sectional view in Fig. 5B .

[0065] It is emphasized that the present invention is in no way limited to the embodiments and features described below. The invention further comprises modifications of the aforementioned embodiments, in particular those resulting from modifications and / or combinations of individual or multiple features of the described embodiments within the scope of protection of the independent claims. Detailed character description

[0066] In the following figures, the flow directions of fuel B and air within the burner devices are indicated by arrows labeled B and L, respectively.

[0067] Fig. 1Figure 1 shows a perspective view of the burner device 100 according to the invention, without showing its internal components. For this purpose, reference is made to the Figs. 2A to 5B referred.

[0068] The combustion device 100 comprises a flame body 1, on whose combustion surface an air-fuel mixture is combusted. The fuel is supplied via a fuel source 200 and the air by a blower 4, wherein a housing 5 of the burner device 100 forms a channel for supplying the air to the flame body 1. The mixing of fuel and air then takes place in an interior space at least partially enclosed by the flame body 1, before the mixture flows through through-openings onto the combustion surface.

[0069] Fig. 2A and 2B show sectional views of a first embodiment of the burner device 100 according to the invention. Fig. 2A shows a longitudinal section and Fig. 2B a cross-section orthogonal to it in the plane AA.

[0070] The burner device 100 comprises a substantially circular cylindrical flame body 1, which partially encloses a similarly circular cylindrical interior space 11, such that the flame body 1 is open at an inlet side 12 for fuel B and air L and closed at the opposite end section 13.

[0071] The circular cylindrical flame body 1 extends from the inlet side 12 along its longitudinal central axis 14, i.e. its central longitudinal axis, to the aforementioned end section 13.

[0072] The interior space 11 is connected via a multitude of through-openings 16 to an outer combustion surface 17 on the cylinder shell of the flame body 1, on which the combustion of the air-fuel mixture takes place, which exits through the through-openings 16 from the mixing area 15 located in the interior space 11. In the mixing area 15, the air-fuel mixture is mixed from air L and fuel B before exiting onto the combustion surface 17.

[0073] To provide the air-fuel mixture to be burned, the burner device 100 comprises a fuel supply device 2, which is at least partially arranged in the interior 11 and which is designed to introduce fuel B into the mixing area 15, which is formed in the interior 11 between the fuel supply device 2 and the flame body 1, more precisely between the double-walled cylinder 22 encompassed by the fuel supply device 2 and the outer shell of the flame body 1.

[0074] The double-walled cylinder 22 serves to transport the fuel B within the interior 11 and forms a fuel channel between a radially inner cylinder wall 22a and a radially outer cylinder wall 22b. The cylinder 22 is designed such that fuel B flowing into the fuel channel from the inlet side 12 passes through outlet openings 26 provided in the radially outer cylinder wall 22a into the mixing area 15 and mixes there with the introduced air L.

[0075] The outlet openings 26 are arranged on a main surface 21 of the fuel supply device 2 or the double-walled cylinder 22 adjacent to the mixing area, in a line with the through-openings 16 of the flame body 1, so that the fuel B can flow along this line (mixing path) and thereby draws in the air L present in the mixing area 15 and mixes with it.

[0076] Fuel B is supplied via a distribution device 25 of the fuel supply device 2, located on the inlet side 12. This distribution device is in turn connected via a supply line to a fuel source 200, for example, a fuel reservoir, tank, or supply network. The distribution device 25 ensures a uniform distribution of fuel B between the cylinder walls 22a and 22b.

[0077] To provide the air L, it is also introduced at the inlet side 12, preferably using a blower 4 (see Fig. 1 ).

[0078] For this purpose, the burner device 100 comprises a flow channel 3 running centrally in the interior 11 along the longitudinal central axis 14 of the flame body 1 for supplying air L to the mixing area 15, which is radially enclosed by the fuel supply device 2 or by the radially inner cylinder wall 22b of the double-walled cylinder 22, so that the flow channel 3 itself is separated from the mixing area 15 in the radial direction.

[0079] In other words, some of the air L supplied at the inlet side 12 can flow to the end section 13 of the flame body 1 without coming into contact with fuel B. Thus, the radially inner cylinder wall 22b acts as the flow wall of the flow channel 3.

[0080] To enable good flow of the air L flowing in the flow channel 3 into the mixing area 15, a deflection area 30 is provided between fuel supply device 2 or between the double-walled cylinder 22 and the end section 13 of the flame body.

[0081] Furthermore, the combustion device 100 includes a second flow channel in the interior 11, which is formed between the radially outer cylinder wall 22a and the flame body 1 on the side of the inlet side 12.

[0082] In this way, the air L is supplied via the two flow channels at both axial ends of the mixing area 15, so that a sufficient air supply is made possible at various points in the mixing area 15 and thus not only "rich" mixtures can be avoided, but also a particularly homogeneous air-fuel mixture can be achieved along the longitudinal central axis 14, i.e., the lowest possible concentration fluctuations of the fuel in the air-fuel mixture (avoidance of local over-richness).

[0083] The setup shown is particularly suitable for use with hydrogen-containing fuel, since (as in the general part of the description) the risk of a flame flashback can be reduced and sufficient air is also available to avoid an overly "rich" mixture across the entire mixing range 15.

[0084] Fig. 3A and 3Bshow sectional views of a second embodiment of the burner device 100 according to the invention. Fig. 3A shows a longitudinal section and Fig. 3B a cross-section orthogonal to it in the plane BB.

[0085] The basic structure of the flame body 1 essentially corresponds to that of the one described above. Fig. 2A and 2B , so that it is not written to again.

[0086] The difference to the first embodiment lies in the implementation of the fuel supply device 2 with a plurality of supply lines 23a instead of the double-walled cylinder 22.

[0087] In this case, the twelve supply lines 23a of the fuel supply device 2 extend from the distributor device 25 towards the end section 13 and are spaced apart from the longitudinal central axis 14 of the flame body 1 around the central flow channel 3.

[0088] The supply lines 23a thus only partially enclose the flow channel 3 in a radial direction, since adjacent supply lines 23 are arranged at a distance from each other with an intermediate spacer area 24 that connects the central flow channel 3 with the mixing area 15.

[0089] Thus, between adjacent supply lines 23a, some of the air L flowing through the flow channel 13 can flow from this into the mixing area 15, so that along the longitudinal central axis 14 air L from the flow channel 3 is continuously supplied to the mixing area 15 in order to provide sufficient air L for a lean air-fuel mixture.

[0090] The supply lines 23 have a non-circular cross-sectional shape with respect to the cross-sectional plane (see Fig. 3B ), in this case an elliptical shape. Other cross-sectional shapes are shown by way of example in Fig. 3CThe figures are shown and, from left to right, depict a polygonal cross-sectional shape 23b in the form of a quadrilateral, a cross-sectional shape as a circular ring segment 23c and a circular cross-sectional shape 23d.

[0091] The supply lines 23a are arranged in the interior such that the semi-axis with maximum extent of the elliptical shape is aligned in the radial direction of the flame body 1 and the semi-axis with minimum extent of the elliptical shape runs in the tangential direction of the flame body 1 (see Fig. 3B ).

[0092] In this way, the spacing 24 between adjacent supply lines 23a can be increased in order to introduce more air L into the mixing zone 15 along the length of the longitudinal center axis 14 without reducing the effective flow area of ​​a supply line 23a, for example compared to a circular cross-sectional shape 23d. At the same time, the distance between the supply lines 23a and the flame body 1 can be reduced in order to shorten the length of the mixing path.

[0093] The distribution device 25 is designed in a circular shape with respect to the cross-sectional plane perpendicular to the longitudinal central axis 14, in order to create a passage for the air L to the flow channel 3 in the center.

[0094] Fig. 4 shows a section in the area of ​​a fuel outlet into the mixing area 15 of a third embodiment of the burner device 100 according to the invention.

[0095] The fuel supply device 2 comprises outlet nozzles 27 for the fuel B, which project radially outwards from a main surface 21 of the fuel supply device 2 adjacent to the mixing area 15 in the direction of the flame body 1, such that a distance D2 between openings of the outlet nozzles 27 and the flame body 1 is less than a distance D1 between the main surface 21 and the flame body 1.

[0096] In this way, the distance to the flame body 1, i.e. the mixing path, can be shortened without excessively reducing the mixing area, which beyond a certain point would only lead to an insufficient supply of air to provide the air-fuel mixture.

[0097] Fig. 5Ashows a section in the area of ​​a fuel outlet into the mixing area 15 of a fourth embodiment of the burner device 100 according to the invention with a cross-section orthogonal to it in the plane CC in Fig. 5B .

[0098] The outer contour of the fuel supply device 2, adjacent to the mixing area 15, has a groove 28 extending along the longitudinal central axis 14 of the flame body 1, within which outlet openings 26 for the fuel B are arranged. The groove 28 is designed as wall elements projecting from the main surface 21 adjacent to the mixing area 15.

[0099] The groove 28 provides a shielding area by which the outlet openings 26 are at least partially shielded from an airflow passing directly over them. This allows for the controlled introduction of fuel B without interference. Furthermore, the groove 28 prevents any backfire from propagating through the entire mixing area 15.

[0100] Above, exemplary embodiments of the present invention and their advantages have been described in detail with reference to the accompanying figures.

[0101] It is emphasized again that the present invention is in no way limited to the embodiments and features described above. The invention further comprises modifications of the aforementioned embodiments, in particular those resulting from modifications and / or combinations of the features of the described embodiments within the scope of protection of the independent claims. List of reference symbols

[0102] 1 Flame body 2 Fuel supply device 3 Flow channel 4 Blower 5 Housing 11 Interior 12 Inlet side 13 End section 14 Longitudinal center axis 15 Mixing area 16 Through opening 17 Combustion surface 21 Main surface adjacent to mixing area 22 Double-walled cylinder 22 Radial outer cylinder wall 22 Radial inner cylinder wall 23a-d Supply line 24 Spacing area 25 Distributor device 26 Outlet openings 27 Outlet nozzle 28 Groove 30 Deflection area 100 Burner device 200 Fuel source Fuel Air

Claims

1. A burner device (100) for providing thermal energy by combustion of an air-fuel mixture, wherein the fuel (B) contains, in particular, hydrogen, comprising: - a generally cylindrically shaped flame body (1) having an inlet side (12) and an outer combustion surface (17) formed on a cylinder jacket of the flame body (1), on which combustion surface the air-fuel mixture is burned, wherein the combustion surface (17) is connected via through openings (16) in the cylinder jacket to an interior space (11) at least partially enclosed by the flame body (1); and - a fuel supply device (2) arranged at least partially in the interior space (11) for introducing fuel (B) into a mixing region (15) for mixing the fuel with air (L) to form the air-fuel mixture;wherein the burner device (100) is designed such that both air (L) and fuel (B) are supplied to the flame body (1) on the inlet side (12) of the flame body (1); and wherein the mixing region (15) is formed in the interior space (11) between the fuel supply device (2) and the flame body (1); ; characterized by a flow channel (3) running centrally in the interior (11) along a longitudinal central axis (14) of the flame body (1) for supplying air (L) into the mixing area (15), which is at least partially enclosed by the fuel supply device (2).

2. Burner device (100) according to claim 1, wherein, based on a cross-sectional plane running perpendicular to the longitudinal center axis (14) of the flame body (1), a ratio of a cross-sectional area of ​​the flow channel (3) to a cross-sectional area of ​​the entire interior (11) is greater than or equal to 20%.

3. Burner device (100) according to claim 1 or 2, wherein a deflection region (30) is formed in the interior (11) between a front end section (13) of the flame body (1) and the fuel supply device (2), via which deflection region the air (L) flowing through the flow channel (3) can be deflected into the mixing region (15).

4. Burner device (100) according to at least one of claims 1 to 3, wherein the flow channel (3) is separated from the mixing area (15) in the radial direction of the flame body (1) by the fuel supply device (2) 5. Burner device (100) at least according to claim 4, wherein the fuel supply device (2) comprises a cylinder (22) which is at least partially double-walled in the interior (11) and has a radially inner and a radially outer cylinder wall (22a, 22b), between which a flow path for the fuel (B) is formed, and wherein the radially inner cylinder wall (22b) is a flow wall of the flow channel (3).

6. Burner device (100) at least according to claim 5, wherein the radially inner and / or the radially outer cylinder wall (22a, 22b) have a circular cross-sectional shape with respect to a cross-sectional plane running perpendicular to the longitudinal central axis (14) of the flame body (1).

7. Burner device (100) according to at least one of claims 1 to 3, wherein the fuel supply device (2) comprises a plurality of supply lines (23a-d) which are arranged around the flow channel (3) at a distance from the longitudinal center axis (14) of the flame body (1), in particular these are arranged uniformly around the flow channel (3) 8. Burner device (100) according to claim 7, wherein the plurality of supply lines (23a-d) comprises between 4 and 24 supply lines (23a-d).

9. Burner device (100) at least according to one of claims 7 or 8, wherein, with respect to a cross-sectional plane extending perpendicular to the longitudinal center axis (14) of the flame body (1), adjacent supply lines (23a-d) of the plurality of supply lines (23a-d) are separated from one another by a spacing region (24) which connects the flow channel (3) to the mixing region (15).

10. Burner device (100) at least according to claim 9, wherein at least one, in particular all, supply lines (23a-d) of the plurality of supply lines (23a-d) is a non-circular supply line (23a-c), wherein said supply line has a cross-sectional shape with respect to a cross-sectional plane running perpendicular to the longitudinal central axis (14) of the flame body (1), the extent of which along a first main axis is greater than the extent of which along a second main axis which is at an angle, in particular perpendicular, to the first main axis, in particular the at least one non-circular supply line (23a-d) has an elliptical cross-sectional shape, wherein the at least one non-circular supply line (23a-d) of the plurality of supply lines (23a-d) is arranged in particular such that the first main axis runs in the radial direction of the flame body (1).

11. Burner device (100) according to at least one of claims 1 to 10, wherein the fuel supply device (2) comprises outlet nozzles (27) for the fuel (B), which protrude radially outwards in the direction of the flame body (1) from a main surface (21) of the fuel supply device (2) adjacent to the mixing region (15), such that a distance between openings of the outlet nozzles (27) and the flame body (1) is smaller than a distance between the main surface (21) and the flame body (1).

12. Burner device (100) according to at least one of claims 1 to 10, wherein an outer contour of the fuel supply device (2) adjacent to the mixing region (15) has a groove (28) running along the longitudinal center axis (14) of the flame body (1), within which outlet openings (26) for the fuel (B) are arranged.

13. A heat generator for transferring thermal energy to a fluid, in particular for use in a heating system or in a domestic water supply system, at least comprising: - a burner device (100) according to one of claims 1 to 12; - a heat exchanger coupled to the burner device (100), via which heat energy provided by the burner device (100) can be transferred to the fluid.

14. A heating system for heating a building, comprising at least: - a piping system for transporting a fluid energy transport medium; and - a heat generator according to claim 13 for heating the energy transport medium to be transported through the piping system.

15. A domestic water supply system for supplying domestic water, comprising at least: - a pipe system for transporting the domestic water; and - a heat generator according to claim 13 for heating the domestic water to be transported through the pipe system.

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