Combustion unit for hydrogen using a catalyst

Abstract

The invention relates to a combustion unit (1) for generating a hot air flow (WLS) by means of a flameless catalytic combustion, comprising an air guide channel (2), through which an air flow (LS) directed along a flow direction flows when the combustion unit (1) is used as intended; a catalyst (3), which is arranged within the air guide channel (2); and a hydrogen inlet (4) for introducing hydrogen into the air supply channel (2) so that the hydrogen, together with the airflow (LS), forms an air-hydrogen mixture which can be catalytically combusted by the catalyst (3). The invention additionally relates to a use of an exhaust gas catalyst of a vehicle, to a use of a catalyst (3), to a device (26) for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or a surrounding area, in particular a heating device, and to a use of a combustion unit (1).

Description

[0001] Combustion unit for hydrogen using a catalyst

[0002] The present invention relates to a combustion unit for generating a warm air flow through flameless, catalytic combustion, comprising an air duct through which, during intended use of the combustion unit, an air flow directed along a flow direction flows, and comprising a catalyst arranged within the air duct and a hydrogen inlet for introducing hydrogen into the air duct so that the hydrogen forms an air-hydrogen mixture with the air flow that can be catalytically combusted by the catalyst. Furthermore, the invention relates to the use of an exhaust gas catalytic converter of a vehicle, the use of a catalyst, a device for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or an environment, in particular a heating device, and the use of a combustion unit.

[0003] Combustion units for generating a warm air stream are widely known from the prior art. Fossil fuels such as propane or fuel oil are frequently used to operate such combustion units. Combustion also typically occurs using a flame, which can pose risks such as explosions. Combustion units for generating a warm air stream using flameless, catalytic combustion are also known, but these are expensive and / or complicated to manufacture. Additionally or alternatively, retrofitting such combustion devices into existing devices for heating food, particularly grills and / or stoves, and / or for emitting heat into a room and / or surroundings, particularly heating devices, is very cumbersome. The object of the present invention is to eliminate the disadvantages known from the prior art.The object is in particular to provide a combustion unit, use of an exhaust gas catalyst of a vehicle, use of a catalyst, device and use of a combustion unit which generates the warm air flow inexpensively, effectively and / or safely.

[0004] The problem underlying the invention is solved by the features of the independent patent claims. Further advantageous embodiments emerge from the subclaims and the drawings.

[0005] A combustion unit is proposed for generating a warm air flow by flameless, catalytic combustion, comprising an air duct through which an air flow directed along a flow direction flows during the intended use of the combustion unit, and comprising a catalyst arranged within the air duct, and comprising a hydrogen inlet for introducing hydrogen into the air duct so that the hydrogen forms an air-hydrogen mixture with the air flow which can be catalytically combusted by the catalyst.

[0006] An air flow is introduced into the air duct, for example, from the environment and / or from upstream elements, in particular from a heat exchanger. The air flow flowing into the air duct system is heated and / or humidified by the catalyst, so that the warm air flow is formed from the air flow.

[0007] The hydrogen is fed to the catalyst as a reaction gas mixture together with the air stream or the oxygen contained in the air stream. The reaction gas mixture is the air-hydrogen mixture. To obtain the necessary thermal energy to heat the air stream, the hydrogen reacts with the air or oxygen in the catalyst. This generates thermal energy through catalysis of the air-hydrogen mixture. The air stream exiting the catalyst is called the warm air stream. In addition to heating, the catalysis of the air-hydrogen mixture contributes to humidifying the warm air stream.

[0008] Because the catalyst catalyzes the air-hydrogen mixture, the heat energy is generated flamelessly. The hydrogen content of the supplied air-hydrogen mixture is preferably outside the explosive range, in particular below 4 vol.%, for example, below 3.5 vol.%. This prevents an explosion of the air-hydrogen mixture.

[0009] It is advantageous if the catalyst is designed as an exhaust catalyst for a motor vehicle, especially a motor vehicle. Vehicle exhaust catalysts are very inexpensive to procure due to mass production. They are also very easy to obtain as spare parts for motor vehicles. This can significantly reduce the costs of the combustion unit. Both the structural design of the catalyst and the chemical properties of the catalytically active coating can be used to generate the warm air flow.

[0010] It is also advantageous if the catalyst comprises a base body with tubular and / or honeycomb-shaped reaction channels, wherein the reaction channels are preferably separated from each other by partition walls in the base body. Thus, the catalyst can be structurally similar to a vehicle catalyst, which can reduce the manufacturing costs of the combustion unit.

[0011] It is also advantageous if the catalyst is designed to be permeable, allowing the air flow and / or the air-hydrogen mixture to flow through it in the direction of flow. In this case, the catalyst is advantageously designed as a permeable grid.

[0012] It is also advantageous if the reaction channels and / or the partition walls are evenly spaced from one another, with the partition walls preferably having a thickness of 0.1–0.5 mm. This allows the base body to be as compact as possible and / or to comprise a large number of reaction channels.

[0013] Furthermore, it is advantageous if the base body is made of monolith and / or ceramic, in particular cordierite and / or AlMg silicate. The metal oxide coating is designed as a porous coating to increase the surface area. Due to this design of the base body, the catalyst is temperature-stable.

[0014] It is also advantageous if the catalyst comprises a metal oxide coating to increase the surface area and / or a platinum, rhodium, iridium, and / or palladium coating as a catalytically active layer. The platinum, rhodium, indium, and / or palladium coatings represent the catalytically active substances.

[0015] It is also advantageous if the catalyst comprises a wire sheath, which preferably completely surrounds the base body and / or is fully in contact with the air duct. The wire sheath can stabilize the base body and / or facilitate its connection to the air duct.

[0016] It is also advantageous if the combustion unit comprises a mixing section, in particular one located upstream of the catalyst along the flow direction, into which the hydrogen and the air stream can be supplied and mixed with each other to form the air-hydrogen mixture. The mixing section is preferably integrated into the air duct and / or formed as a duct section of the air duct.

[0017] Furthermore, it is advantageous if the combustion unit comprises a bypass duct, wherein the air duct is preferably arranged within the bypass duct, so that the air flow can be heated within the air duct to form the warm air flow and / or a fresh air flow can be guided outside the air duct within the bypass duct. If the combustion unit has the bypass duct, the mixing section can also be arranged within the bypass duct and / or upstream of the air duct along the flow direction.

[0018] It is advantageous if the air guide channel and / or the bypass channel have a round cross-section, wherein the air guide channel is preferably arranged concentrically within the bypass channel and / or the bypass channel is annular.

[0019] Furthermore, it is advantageous if the hydrogen inlet protrudes into the mixing section as a hydrogen line and / or breaks through the air guide channel and / or the bypass channel.

[0020] It is also advantageous if the air duct and / or the bypass duct is designed as a Venturi nozzle and / or the hydrogen inlet is arranged at a constriction of the air duct and / or the bypass duct. The design as or similar to a Venturi nozzle has the advantage that the incoming air flow and / or warm air flow and / or fresh air flow into the air duct and / or the bypass duct can be accelerated due to the pressure difference along the flow direction.

[0021] It is also advantageous if the air guide channel and / or the bypass channel comprises a first section that tapers, in particular conically, a second section that is in particular cylindrical and / or of constant diameter, and / or a third section that widens, in particular conically, wherein the first section, the second section and / or the third section are preferably arranged adjacent to one another and / or merge tangentially into one another. Alternatively, the second section can merge tangentially into the first section and the third section as a constriction. This ensures reliable mixing of the hydrogen flowing into the mixing section with the air flow also flowing in. This configuration essentially corresponds to the design as a Venturi nozzle.Preferably, the first section and the third section have different lengths, wherein preferably the first section has a shorter length than the third section along the flow direction.

[0022] It is also advantageous if the hydrogen inlet, which is designed in particular as a hydrogen line, comprises an outflow opening which is preferably arranged centrally to the catalyst and / or an outflow direction of the hydrogen flowing out of the outflow opening runs in the flow direction of the air flow.

[0023] It is also advantageous if the combustion unit comprises at least one impeller, in particular a fan wheel and / or a turbine wheel, for accelerating and / or compressing the air flow, the warm air flow and / or the fresh air flow, wherein the impeller is preferably arranged in the region of an air inlet and / or an air outlet of the air duct.

[0024] It is also advantageous if the at least one impeller is arranged along the flow direction within the air duct and / or outside the air duct, in particular upstream and / or downstream of the air duct. It is also advantageous if the impeller is smaller than the cross-section of the air duct when arranged within the air duct and / or smaller than the cross-section of the bypass duct when arranged outside the air duct.

[0025] It is also advantageous if the impeller is assigned a drive for continuous and / or short-term operation. The drive can be designed as a short-term starter.

[0026] It is also advantageous if the combustion unit comprises at least two impellers, which are preferably spaced apart from one another and / or are operatively connected to one another via a shaft.

[0027] It is also advantageous if the catalyst has a through-opening for the shaft, in particular a centrally arranged one, wherein a sealing section and / or a bearing for the shaft is preferably arranged at the through-opening.

[0028] Additionally or alternatively, the combustion unit comprises a control device. The control device preferably receives an actual temperature via at least one temperature sensor and / or a room air sensor and adjusts it to the target temperature specified by the user by appropriately controlling the at least one impeller and / or a hydrogen valve.

[0029] The control device preferably receives an actual humidity via at least one humidity sensor and / or the room air sensor and regulates this to the target humidity specified by the user by appropriately controlling the at least one impeller and / or the hydrogen valve. Additionally or alternatively, the control device can determine a target mixing ratio of the air-hydrogen mixture, in particular based on the specified target temperature and / or the target humidity. Additionally or alternatively, this target mixing ratio can be specified to the control device. Additionally or alternatively, mathematically and / or empirically determined target mixing ratios correlating with the target temperature and / or the target humidity can be stored in a memory of the control device.The control device is preferably designed such that, based on the target mixing ratio, it adjusts the actual mixing ratio of the air-hydrogen mixture sensed by at least one of the sensors, in particular the gas sensor, to the target value.

[0030] Furthermore, the use of an exhaust gas catalyst of a motor vehicle, in particular a motor vehicle, for example a passenger car, in a combustion unit is proposed. Vehicle exhaust gas catalysts are very inexpensive to procure due to mass production. They are also very easy to obtain as spare parts for motor vehicles. This can significantly reduce the costs of the combustion unit. Both the structural design of the catalyst and the chemical properties of the catalytically active coating can be used to generate the warm air flow.

[0031] The combustion device is preferably designed according to the preceding description, wherein the features mentioned can be present individually or in any combination.

[0032] Furthermore, the use of a catalyst comprising a base body with tubular and / or honeycomb-shaped reaction channels in a combustion unit is proposed. The combustion device is preferably designed according to the preceding description, wherein the aforementioned features can be present individually or in any combination.

[0033] It is advantageous if the catalyst has one or more features of the preceding description, wherein the features mentioned can be present individually or in any combination.

[0034] Furthermore, a device for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or an environment, in particular a heating device, is proposed. The device comprises a combustion unit for generating a warm air flow through flameless, catalytic combustion according to the preceding description, wherein the aforementioned features can be present individually or in any combination.

[0035] A device for heating food can be understood as, for example, a cooking device, a cooking area, a grill and / or a stove, in particular for outdoor and / or indoor use. A device for emitting heat, in particular thermal radiation and / or a flow of warm air, to the environment can be understood as, for example, a heating device, a radiant heater, a fan heater, a fireplace, a heating element, a patio heater and / or an open fireplace, in particular for outdoor and / or indoor use. The outdoor and / or indoor areas are understood to be the location of the device at which it can be operated. Thus, the outdoor area is understood to be the location of the device outdoors and / or in the open air. The indoor area is understood to be the location of the device in a building, house, tent, boat, mobile home and / or caravan.It is advantageous if the device comprises a heat exchanger for transferring the thermal energy of the warm air flow into a working medium and / or for preheating the air flow.

[0036] Furthermore, the use of a combustion unit according to the above description in a device for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or surroundings is proposed. The aforementioned features of the combustion unit can be present individually or in any combination.

[0037] It is advantageous if the device has one or more features of the preceding description, wherein the features mentioned can be present individually or in any combination.

[0038] Further advantages of the invention are described in the following exemplary embodiments. They show:

[0039] Figure 1 is a highly simplified schematic sectional view of a combustion unit according to an embodiment,

[0040] Figure 2 is a highly simplified schematic sectional view of a combustion unit according to an alternative embodiment,

[0041] Figure 3 is a highly simplified schematic sectional view of a combustion unit according to a further embodiment, and

[0042] Figure 4 shows a highly simplified schematic sectional view of a device with a combustion unit according to another alternative embodiment. In the following description of the figures, the same reference numerals are used for identical and / or at least comparable features in the various figures. The individual features, their design, and / or mode of operation are usually only explained in detail when first mentioned. If individual features are not explained in detail again, their design and / or mode of operation correspond to the design and mode of operation of the features with the same or identical functions already described.

[0043] Furthermore, it should be noted that all subsequent embodiments of the combustion unit 1 of Figures 1 to 3 can be arranged, for example, in a device 26, in particular according to Figure 4, for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or an environment, in particular a heating device.

[0044] Figure 1 shows a highly simplified sectional view of a combustion unit 1 for generating a warm air flow WLS by flameless, catalytic combustion according to an embodiment.

[0045] The combustion unit 1 comprises an air duct 2, through which, during intended use, an air flow LS flows along a flow direction. The combustion unit 1 further comprises a hydrogen inlet 4, which can introduce the hydrogen into the air duct 2, so that the hydrogen mixes with the air flow LS and forms an air-hydrogen mixture. By means of a catalyst 3 arranged within the air duct 2, the air flow LS can be heated to the warm air flow WLS. For this purpose, the air-hydrogen mixture can be catalytically and flamelessly burned by means of the catalyst 3. In the exemplary embodiment shown, the catalyst 3 is preferably designed as an exhaust gas catalytic converter of a vehicle, in particular a motor vehicle, for example a passenger car. This leads to a simple and cost-effective design of the combustion unit 1.Corresponding exhaust gas catalysts can be ordered as spare parts and can be used in combustion unit 1.

[0046] The catalyst 3, particularly as an exhaust gas catalyst, comprises, in the illustrated embodiment, a base body 5 with tubular or honeycomb-shaped reaction channels 6. The reaction channels 6 are separated from one another by partition walls 7. Preferably, the reaction channels 6 and / or the partition walls 7 are evenly spaced from one another, with the partition walls 7 preferably having a thickness of 0.1-0.5 mm.

[0047] The base body 5 can be formed, for example, from a monolith and / or ceramic, in particular from cordierite and / or AlMg silicate. Corresponding base bodies 5 are known, for example, from exhaust gas catalysts installed in vehicles. The catalyst 3 further comprises a metal oxide coating to increase the surface area and / or a platinum, rhodium, indium, and / or palladium coating as a catalytically active layer.

[0048] For stabilization or to ensure contact with the air duct 2, the catalytic converter 3 in the illustrated embodiment has a wire sheath 8. The base body 5 of the catalytic converter 3 is encased, in particular completely, by means of the wire sheath 8.

[0049] To provide the air-hydrogen mixture in a mixed state to the catalyst 3, the combustion unit 1 has a mixing section 9. In the mixing section 9, the hydrogen can be combined and / or mixed with the air flow LS to form the air-hydrogen mixture. The hydrogen inlet 4 preferably extends into the mixing section 9 as a hydrogen line 12. The hydrogen can flow out of the hydrogen line 12 via an outflow opening 17. The hydrogen inlet 4, designed as a hydrogen line 12, penetrates the air guide channel 2 and a bypass channel 10.

[0050] In order to guide a fresh air flow FLS outside the air duct 2, the combustion unit 1 in the illustrated embodiment has the bypass duct 10. The air duct 2 is preferably arranged within the bypass duct 10. Within the air duct 2, the air flow LS is heated to the warm air flow WLS. Outside the air duct 2, in an air gap 11 between the air duct 2 and the bypass duct 10, the air flow LS is guided past as a fresh air flow FLS. The air duct 2 and / or the bypass duct 10 can have a round cross-section, whereby the air duct 2 can be arranged, for example, concentrically within the bypass duct 10.

[0051] To accelerate and / or compress the air flow LS, the warm air flow WLS and / or the fresh air flow FLS, the combustion unit 1 advantageously comprises, as shown in the exemplary embodiment shown, at least one impeller 18. In the initial example shown, a first impeller 18a is arranged at an air inlet 19 or in a region of the air inlet 19 of the air duct 2. The air flow LS is introduced into the air duct 2 through the air inlet 19. After passing through the mixing section 9 and the catalyst 3, the air flow LS can flow out of an air outlet 20 of the air duct 2 as a warm air flow WLS.

[0052] A second impeller 18b is arranged upstream of the air duct 2 along the flow direction of the air flow LS. In the illustrated embodiment, the first impeller 18a accelerates the air within the air duct 2 and thus the warm air flow WLS. The upstream second impeller 18b accelerates the air flow LS and thus the flow velocity within the bypass duct 10 and the air duct 2. The second impeller 18b thus determines the flow velocity of the air flow LS, the fresh air flow FLS, and the warm air flow WLS. The first impeller 18a preferably ensures the air supply to the catalytic converter 3 and adjusts the resulting warm air flow WLS.

[0053] Figure 2 shows a highly simplified sectional view of a combustion unit 1 for generating a warm air flow WLS through flameless, catalytic combustion according to an alternative embodiment. Although the catalyst 3 is designed here as a partition wall through which flow is easily passed, comprising, for example, a grid, it should be noted that in all embodiments of the combustion units 1 according to Figures 2 to 4, the catalyst 3 can be designed similarly to Figure 1.

[0054] In contrast to the exemplary embodiment in Figure 1, in the exemplary embodiment in Figure 2, at least one impeller 18 is arranged both in the area of ​​the air inlet 19 and in the area of ​​the air outlet 20 of the air duct 2. The first impeller 18a is arranged in the area of ​​the air inlet 19. A third impeller 18c is arranged in the area of ​​the air outlet 20. The second impeller 18b is arranged downstream of the air duct 2 along the flow direction. The second impeller 18b can thus be larger than the first impeller 18a and / or the third impeller 18c, since the latter can extend as far as the bypass duct 10. The first impeller 18a and the third impeller 18c can accelerate and / or compress the warm air flow WLS. The second impeller 18b can additionally or alternatively accelerate and / or compress the fresh air flow FLS.

[0055] The impellers 18 are spaced apart from one another and connected to one another via a shaft 22. The shaft 22 can connect the impellers 18 to one another in a rotationally fixed manner. It is also conceivable for the shaft 22 to comprise a gear so that the impellers 18 can assume different rotational speeds. To pass the shaft 22 through the catalytic converter 3, the latter has a preferably centrally arranged through-opening 23. To support the shaft 22, a bearing 25, in particular a rolling bearing and / or a plain bearing, can be arranged at the through-opening 23. Additionally or alternatively, a sealing section 24 can be arranged at the through-opening 23, which seals the shaft 22 from the catalytic converter 3.

[0056] To drive the impellers 18, the combustion unit 1 has at least one drive 21. In the illustrated embodiment, the drive 21 is connected to the shaft 22. The drive 21 can drive the impellers 18 continuously or only briefly. If the drive 21 is only needed for a short time, it can also be called a starter.

[0057] Additionally, the air duct 2 in the illustrated embodiment is designed as a Venturi nozzle. The hydrogen is introduced through the hydrogen inlet 4 at a constriction 13 of the air duct 2. The air duct 2 can essentially be divided into three sections. The first section 14 is tapered. The second section 15 is defined by the constriction 13. The third section 16 is widened. By configuring the air duct 2 as a Venturi nozzle, the mixing of the air-hydrogen mixture can be improved. It is also conceivable that after the onset of flameless combustion by means of the catalyst 3, the warm air flow WLS drives at least one of the impellers 18, which is why the drive 21 can be switched off. In this case, the drive 21 can be designed as a starter, as already described above.Additionally or alternatively, it is conceivable that the bypass channel 10 also comprises a constriction and / or is designed to correspond to the air guide channel 2. Figure 3 shows a highly simplified sectional view of a combustion unit 1 for generating a warm air flow WLS by flameless, catalytic combustion according to a further embodiment.

[0058] In contrast to the previous embodiments, no bypass channel 10 is shown here. It is conceivable that the combustion unit 1 of the embodiment of Figure 3 comprises a bypass channel 10, in particular according to the previous embodiments. Likewise, the combustion units 1 in the embodiments of Figures 1 and 2 can be designed without a bypass channel 10.

[0059] In addition, a control device 28 is shown by way of example in the exemplary embodiment in Figure 3. The control device 28 is operatively connected, in particular by means of control lines, to at least one sensor 29, at least one hydrogen valve 30 and / or at least one of the impellers 18. In this way, the amount of inflowing hydrogen, the flow velocity of at least one of the air streams LS, WLS, FLS and / or the temperature and / or humidity of the warm air stream WLS can be controlled. The composition and / or mixing ratio of the air-hydrogen mixture can also be determined. The sensor 29 can be designed as a temperature sensor and / or humidity sensor and / or gas sensor. The control device 28 and / or the sensors 29 and / or the hydrogen valve 30 can, in a similar configuration, also be arranged in and / or on the combustion units 1 and / or the device 26 of the exemplary embodiments in Figures 1, 2 and 4.

[0060] Figure 4 shows a highly simplified sectional view of a device 26 for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or an environment, in particular a heating device. This device comprises a combustion unit 1 for generating a warm air flow WLS through flameless, catalytic combustion according to a further alternative embodiment. It is conceivable that the device 26 comprises a combustion unit 1 according to one of the embodiments of Figures 1-3. It is also conceivable that the combustion unit 1 of Figure 4 is designed as a stand-alone device.

[0061] The combustion unit 1, similar to the embodiment of Figure 2, has the air duct 2 designed as a Venturi nozzle. However, no impellers 18 are arranged on the air duct 2. Only the bypass channel 10 has an impeller 18. Furthermore, the combustion unit 1 differs from the previous embodiments in that the hydrogen flows out centrally toward the catalyst 3 in an outflow direction AR, which runs in the direction of the air flow. This can contribute to better mixing of the air-hydrogen mixture and / or better / easier flow through the air duct 2.

[0062] To transfer the thermal energy, the device 26 comprises a heat exchanger 27. By means of the heat exchanger 27, the warm air flow WLS can transfer its thermal energy to a working medium, in particular a liquid one. With the aid of the working medium, in particular a liquid one, heat can be emitted into a room and / or an environment and / or food can be heated. For example, such a working medium can operate a building's hot water tank.

[0063] The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are possible, as are combinations of features, even if these are illustrated and described in different embodiments.

[0064] 1 combustion unit

[0065] 2 air duct

[0066] 3 Catalyst

[0067] 4 Hydrogen inlet

[0068] 5 basic bodies

[0069] 6 reaction channels

[0070] 7 partition walls

[0071] 8 Wire sheath

[0072] 9 Mixing section

[0073] 10 Bypass channel

[0074] 11 Air gap

[0075] 12 Hydrogen pipeline

[0076] 13 bottleneck

[0077] 14 first section

[0078] 15 second section

[0079] 16 third section

[0080] 17 Outlet opening

[0081] 18a, 18b, 18c wheel

[0082] 19 Air intake

[0083] 20 Air outlet

[0084] 21 Drive

[0085] 22 Wave

[0086] 23 Passage opening

[0087] 24 Sealing section

[0088] 25 Storage

[0089] 26 Device

[0090] 27 heat exchangers

[0091] 28 Control device

[0092] 29 Sensor 30 Hydrogen valve

[0093] LS airflow

[0094] WLS warm air flow FLS fresh air flow

[0095] AR outflow direction

Claims

Patent claims Combustion unit (1) for generating a warm air flow (WLS) by flameless, catalytic combustion, with an air duct (2) through which an air flow (LS) directed along a flow direction flows during intended use of the combustion unit (1), and with a catalyst (3) arranged within the air duct (2), and with a hydrogen inlet (4) for introducing hydrogen into the air duct (2) so that the hydrogen forms an air-hydrogen mixture with the air flow (LS) that can be catalytically combusted by the catalyst (3). Combustion unit (1) according to the preceding claim, characterized in that the catalyst (4) is designed as an exhaust gas catalyst of a motor vehicle.Combustion unit (1) according to one of the preceding claims, characterized in that the catalyst (3) comprises a base body (5) with tubular and / or honeycomb-shaped reaction channels (6), wherein the reaction channels (6) are preferably separated from one another by partition walls (7) of the base body (5). Combustion unit (1) according to one of the preceding claims, characterized in that the reaction channels (6) and / or the partition walls (7) are evenly spaced from one another, wherein the partition walls (7) preferably have a thickness of 0.1-0.5 mm. Combustion unit (1) according to one of the preceding claims, characterized in that the base body (5) is made of monolith and / or ceramic, in particular cordierite and / or AlMg silicate. Combustion unit (1) according to one of the preceding claims, characterized in that the catalyst (3) comprises a metal oxide coating to increase the surface area and / or a platinum, rhodium, iridium, and / or palladium coating as a catalytically active layer. Combustion unit (1) according to one of the preceding claims, characterized in that the catalyst (3) comprises a wire sheath (8) which preferably completely surrounds the base body (5) and / or lies completely against the air duct (2).Combustion unit (1) according to one of the preceding claims, characterized in that the combustion unit (1) comprises a mixing section (9), in particular arranged upstream of the catalyst (3) along the flow direction, in which the hydrogen and the air stream (LS) can be supplied and mixed with one another to form the air-hydrogen mixture. Combustion unit (1) according to one of the preceding claims, characterized in that the combustion unit (1) comprises a bypass channel (10), wherein the air guide channel (2) is preferably arranged within the bypass channel (10), so that the air stream (LS) can be heated to the warm air stream (WLS) within the air guide channel (2). and / or within the bypass channel (10) a fresh air flow (FLS) can be guided past outside the air guide channel (2). Combustion unit (1) according to one of the preceding claims, characterized in that the air guide channel (2) and / or the bypass channel (10) have a round cross-section, wherein the air guide channel (2) is preferably arranged concentrically within the bypass channel (10) and / or an air gap (11) for the fresh air flow (FLS) is formed between the bypass channel (10) and the air guide channel (2). Combustion unit (1) according to one of the preceding claims, characterized in that the hydrogen inlet (4) projects into the mixing section (9) as a hydrogen line (12) and / or breaks through the air guide channel (2) and / or the bypass channel (10).Combustion unit (1) according to one of the preceding claims, characterized in that the air guide channel (2) and / or the bypass channel (10) is designed as a Venturi nozzle and / or the hydrogen inlet (4) is arranged at a constriction (13) of the air guide channel (2) and / or the bypass channel (10). Combustion unit (1) according to one of the preceding claims, characterized in that the hydrogen inlet (4), designed in particular as a hydrogen line (12), comprises an outflow opening (17) which is preferably arranged centrally to the catalyst (3) and / or an outflow direction (AR) of the hydrogen from the outflow opening (17). outflowing hydrogen runs in the flow direction of the air flow (LS). Combustion unit (1) according to one of the preceding claims, characterized in that the combustion unit (1) comprises at least one impeller (18) for accelerating and / or compressing the air flow (LS), the warm air flow (WLS) and / or the fresh air flow (FLS), wherein the at least one impeller (18) is preferably arranged in the region of an air inlet (19) and / or an air outlet (20) of the air duct (2). Combustion unit (1) according to one of the preceding claims, characterized in that the at least one impeller (18) is arranged along the flow direction within the air duct (2) and / or outside the air duct (2), in particular before and / or after the air duct (2).Combustion unit (1) according to one of the preceding claims, characterized in that the impeller (18) is assigned a drive (21) for continuous and / or short-term driving. Combustion unit (1) according to one of the preceding claims, characterized in that the combustion unit (1) comprises at least two impellers (18a, 18b, 18c), which are preferably spaced apart from one another and / or are operatively connected to one another via a shaft (22). Combustion unit (1) according to one of the preceding claims, characterized in that. that the catalyst (3) has a through-opening (23), in particular a centrally arranged through-opening (23) for the shaft (22), wherein a sealing section (24) and / or a bearing (25) for the shaft (22) is preferably arranged at the through-opening (23). Use of an exhaust gas catalyst of a motor vehicle in a combustion unit (1), in particular according to one or more of the preceding claims. Use of a catalyst (3) which comprises a base body (5) with tubular and / or honeycomb-shaped reaction channels (6), in a combustion unit (1), in particular according to one of claims 1 to 20. Use according to the preceding claim, characterized in that the catalyst (3) has one or more features of claims 1 to 20.Device (26) for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or an environment, in particular a heating device, characterized by a combustion unit (1) for generating a warm air flow (WLS) by flameless, catalytic combustion according to one of claims 1 to 20. Device (26) according to the preceding claim, characterized in that the device (26) comprises a heat exchanger (27) for transferring the thermal energy of the warm air flow (WLS) into a working medium and / or for preheating the air flow (LS). Use of a combustion unit (1) according to one of claims 1 to 20, in a device (26) for heating food, in particular a grill and / or stove, and / or for emitting heat into a room and / or an environment, in particular according to one of claims 22 and 23.

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