NOZZLE ASSEMBLY WITH SPIN-FREE AIR AND HYDROGEN FLOW

Description

[0001] The proposed solution concerns a nozzle assembly for a combustion chamber of an engine with at least one nozzle for injecting hydrogen into a combustion chamber of the combustion chamber.

[0002] Nozzle assemblies for engine combustion chambers are widely known in various designs. The focus of conventional nozzles in such assemblies is the injection of liquid fuels, such as kerosene or diesel. Typically, the fuel is mixed with air within the nozzle itself to create an ignitable fuel-air mixture immediately downstream of the nozzle tip. The air to be mixed is typically swirled within the nozzle, resulting in a swirling fuel-air flow with relatively high turbulence downstream of the nozzle tip, which is considered advantageous for the combustion of kerosene, for example.

[0003] US Patent 2010 / 212322 A1 specifies a nozzle assembly for a combustion chamber designed as an air / fuel premixing unit. A radially inner first air guide channel, a radially outer second air guide channel, and a fuel channel arranged radially between them each open into a mixing chamber of the nozzle assembly, after which the air-fuel mixture flows into the combustion chamber. A swirl device may be provided in one or both air streams upstream of the fuel injection into the mixing chamber.

[0004] US patent 2010 / 0050644 A1 discloses a nozzle assembly for a gas turbine with a pilot injector and a main injector arranged radially outside the pilot injector. A film laying surface is formed within a fuel housing, to which fuel is supplied.

[0005] US 2015 / 0253011 A1 shows a nozzle assembly for a combustion chamber of a gas turbine, in which premixing channels are provided for premixing fuel and air.

[0006] More recently, there has been an increasing trend in the development of engine concepts that are partially or fully powered by hydrogen. However, if an engine is to be operated with hydrogen instead of kerosene or diesel while maintaining the same basic design, a different injection method is required for the hydrogen, which is introduced into the combustion chamber in gaseous form and is also significantly more flammable.

[0007] Against this background, the nozzle assembly of claim 1 is proposed, which comprises a nozzle for injecting hydrogen into a combustion chamber of an engine-side combustion chamber.

[0008] A proposed nozzle has a main body extending along a longitudinal axis and a nozzle head at one end. The nozzle has at least one first air guide channel (e.g., in the main body or the nozzle head) to direct a first airflow toward the combustion chamber and into the combustion chamber via at least one first air outlet of the first air guide channel. The nozzle head of the nozzle has at least one fuel channel and at least one second air guide channel. The fuel channel is configured to guide hydrogen toward the combustion chamber. A second airflow can be guided toward the combustion chamber via the at least one second air guide channel and into the combustion chamber via at least one second air outlet of the second air guide channel.In a proposed nozzle with a fuel outlet opening for the hydrogen to be injected into the combustion chamber, the fuel channel is arranged between the first and second air guide channels with their first and second air outlet openings, respectively, in a radial direction perpendicular to the nozzle's longitudinal axis. Furthermore, it is provided that at least the second, radially more outward-positioned air guide channel is designed and configured to provide an undisturbed airflow into the combustion chamber, and that the fuel channel is designed and configured to provide an undisturbed flow of hydrogen into the combustion chamber.

[0009] The proposed solution is based on the fundamental principle of introducing at least a radially outer airflow and a hydrogen flow into the combustion chamber in a way that is as undistorted as possible, in order to prevent coherent flow structures. This ensures that both the airflow from the radially outer second air duct and the hydrogen flow from the fuel channel are introduced into the combustion chamber at the highest possible flow velocity in the axial direction (relative to the nozzle's longitudinal axis). Furthermore, one nozzle of the proposed nozzle assembly is designed to introduce hydrogen and air into the combustion chamber unmixed, i.e., without mixing within the nozzle. Combined with the high axial flow velocities of hydrogen and air achievable via the proposed nozzle assembly, this results in a flammable fuel-air mixture only forming downstream of one nozzle end.Given the highly flammable nature of hydrogen, this is advantageous, as it allows combustion to continue further downstream towards the nozzle end.

[0010] In particular, the nozzle of the proposed nozzle assembly can be configured and designed for rich quench lean combustion.

[0011] The second, radially outward-facing air duct and the fuel duct extend radially outward at their respective duct ends (which feature the second air outlet or the fuel outlet). Both the second, radially outward-facing air duct and the fuel duct thus have a radially outward-facing duct section at one nozzle end, so that the air or hydrogen discharged from these sections exhibits a radial outward flow component during engine operation.

[0012] In this context, it may be provided that the second, radially more outwardly located air duct includes a duct section with the second air outlet opening, which runs at an angle of 30° to 60° to the nozzle's longitudinal axis, particularly at an angle of 35° to 50°. Alternatively or additionally, the fuel duct may include a duct section with the fuel outlet opening, which runs at an angle of 30° to 60°, particularly at an angle of 35° to 50°, to the nozzle's longitudinal axis. If a respective duct section of the air duct and / or the fuel duct, each with its associated outlet opening, extends radially outwards at such a comparatively large (opening) angle to the nozzle's longitudinal axis, the formation of a recirculation zone downstream of the nozzle end can be promoted.Combustion temperatures in the immediate vicinity downstream of the nozzle end can thus be kept comparatively low, even though more easily flammable hydrogen is injected into the combustion chamber.

[0013] To increase the flow velocities at which hydrogen and air are introduced into the combustion chamber from the fuel channel and the second, radially outward-positioned air duct, and optionally to keep a boundary layer (where the velocity is lower) thin, one design variant provides that the fuel channel and / or the second, radially outward-positioned air duct taper towards their respective ends. This includes, for example, the fuel channel and / or the second air duct having two adjacent channel sections in the flow direction of the respective fluid (hydrogen or air), of which a second channel section, containing the respective outlet opening, tapers towards the channel end. Such a second channel section can also be designed with a radially outward-facing orientation.

[0014] In principle, the two adjacent channel sections in the flow direction of the respective fluid can also have different profiles and / or flow cross-sections. For example, a first channel section can have a straight profile or one that tapers towards the second channel section along the nozzle's longitudinal axis. The second channel section, which may taper further, then connects to this first channel section.

[0015] In one embodiment, a central fuel supply line is provided in the nozzle body for supplying hydrogen to the fuel channel. This means, in particular, that the central fuel supply line runs centrally along the nozzle's longitudinal axis within the nozzle body.

[0016] To guide hydrogen from a central fuel supply line to the radially outer fuel channel, at least one corresponding fluid guide can be provided on the nozzle head. Part of such a fluid guide is then, for example, located within a radially outward-extending strut of the nozzle head, which runs through a section of the first air guide channel. Via the fluid guide housed in one or more radially extending struts, the hydrogen originating from the central fuel supply line is thus guided radially outward and (protected within each strut) through the first, radially inner air guide channel to the fuel channel through which the hydrogen is injected into the combustion chamber.

[0017] In principle, one or more struts extending radially along the nozzle head can also serve to fix the sections of the nozzle head forming the first and second air guide channels as well as the fuel channel to the main nozzle body.

[0018] In one embodiment, a stabilizing element is centrally located at one nozzle end, comprising a substantially flat end face facing the combustion chamber. This stabilizing element thus provides a substantially flat end face through which air and hydrogen are introduced radially outwards via the first and second air outlets and the fuel outlets. A central stabilizing element with a substantially flat and, in particular, comparatively large end face promotes the formation of a zone in the immediate vicinity downstream of the nozzle end where the axial velocity is comparatively low, thereby creating a stable recirculation zone that ensures flame stability.Furthermore, a suitable stabilizing body can not only stabilize the flow and flame within the combustion chamber, but also simplify the process of (pre-)vaporizing the gaseous hydrogen being injected. In this way, hydrogen can be (pre-)vaporized directly on the stabilizing body itself.

[0019] For more compact integration of the stabilizer at the nozzle end, it can be provided that the stabilizer, with its outer surface, defines at least part of an inner wall of the first radially inner air duct. The first radially inner (and in a further development, therefore, the most radially inner) air duct thus guides air along the outer surface of the stabilizer. Here, the stabilizer, with its outer surface, can also define a radially outward-facing inner wall section for the first air duct, so that the first air duct extends radially outward at its end.Analogous to a possible course of the second air duct and / or the fuel duct mentioned above, in a further development based on this, the first air duct can also run at its duct end at an angle in the range of 30° to 60°, in particular from 35° to 50° to the nozzle longitudinal axis.

[0020] Alternatively or additionally, the first radially inner air duct, which extends at least partially along a radially outer surface of the stabilizing body, can taper towards its end. In such a design variant, this also achieves a corresponding acceleration of the airflow from the first air duct. Furthermore, the acceleration of the flow from the first air duct can reduce the influence of any webs present in the first air duct on the airflow, resulting in a largely uniform airflow.

[0021] With a view to maximizing the recirculation zone downstream of the nozzle end, the essentially flat end face of the nozzle-side stabilizing body, which faces the combustion chamber, can be designed to be comparatively large. For this purpose, it is provided, for example, that this end face has a radial extent, relative to the nozzle's longitudinal axis, that corresponds to at least twenty times, and in particular at least thirty or forty times, the channel height of the first air guide channel at the first air outlet opening and / or the channel height of the second air guide channel at the second air outlet opening and / or the channel height of the fuel channel at the fuel outlet opening.For example, the ratio of the diameter of a circular end face of the stabilizer to the channel height of a respective channel for the incoming air or injected hydrogen can be at least 20:1, 30:1, or 40:1. This underscores the comparatively large extent of the stabilizer's end face relative to the cross-sectional area through which the fluid flows, which is available at the respective outlet opening of a first or second air outlet channel and / or a fuel channel.

[0022] In principle, a first or second air outlet channel and / or a fuel channel can be designed as an annular gap or annular segment gap at the nozzle end. The respective annular gap or annular segment gap extends circumferentially (completely in the case of an annular gap, or partially in the case of an annular segment gap) around the end face of the stabilizing body.

[0023] In one design variant, cooling is provided for the stabilizer. Such cooling can be achieved, for example, using air or hydrogen. With hydrogen cooling, the hydrogen being injected can be used for this purpose, so that the stabilizer serves to (pre-)vaporize the hydrogen before it is subsequently injected into the combustion chamber. This also makes it easier, for example, to initially supply the hydrogen to the nozzle head in liquid form.

[0024] In principle, at least part of the fluid path, through which hydrogen is guided from a central fuel supply line in the main nozzle body to the radially outer fuel channel, can be located at least partially within the stabilizer body. This includes, in particular, the possibility that a portion of the fluid path located within the stabilizer body is also intended for cooling the stabilizer body.

[0025] In one possible further development, this is achieved, for example, by directing hydrogen, via the fluid guide within the stabilizing body, against a rear wall of the stabilizing body facing away from the combustion chamber, to provide impact cooling of the stabilizing body. The rear wall, which forms the back of the end face facing the combustion chamber, can thus be cooled by the hydrogen flowing onto it before the hydrogen is subsequently directed radially outwards to the fuel channel. At least part of the fluid guide for the hydrogen is therefore designed within the stabilizing body in such a way that, during engine operation, impact cooling of the stabilizing body occurs via the injected hydrogen before the hydrogen is directed radially outwards in the nozzle head to the fuel channel and from there into the combustion chamber without swirl.

[0026] In an alternative design variant, which does without a central fuel supply line and, if applicable, without a centrally arranged stabilizing body, a first air guide channel can be provided centrally on the nozzle main body, running along the nozzle's longitudinal axis. A fuel supply line for the fuel channel is then provided in the nozzle main body in a radially outer section of the nozzle main body.

[0027] In such a design variant, the first central air duct can, for example, widen at its end where the first air outlet opening is located. This radial widening incorporates, for instance, a flow-guiding element extending radially outwards along the first air duct. This flow-guiding element can extend radially outwards at an angle of 30° to 60° to the nozzle's longitudinal axis, particularly at an angle of 35° to 50°. Especially in combination with a straight airflow from the second, radially more outward-facing air duct and a straight flow of hydrogen from the fuel channel, optionally also directed radially outwards, such a nozzle configuration can prove advantageous for hydrogen injection.In contrast to the second air duct and the fuel channel, swirling the air in the first air duct can be advantageous. For this purpose, at least one swirl element is provided in the first air duct.

[0028] In one embodiment with a central first air guide channel, a centrally arranged flow divider is provided. This flow divider splits the airflow within the first air guide channel into an inner and an outer air guide channel section as it flows towards the nozzle end. In this way, the flow divider enables two separate partial airflows radially inwards with respect to the fuel outlet opening of the fuel channel. An outer air guide channel section can deliver a more rapidly accelerated portion of the airflow towards the fuel being introduced. The central inner air guide channel section provides a comparatively slower partial airflow, which primarily serves to lean out the resulting fuel-air mixture.This means that the resulting fuel-air mixture is not immediately flammable in the immediate vicinity of the nozzle, thus preventing higher temperatures in the immediate vicinity of the nozzle end.

[0029] The flow divider can, for example, be designed with a central pipe section having a constant cross-sectional area along the nozzle's longitudinal axis and a diffuser section extending downstream from the pipe section towards the nozzle end. The diffuser section has a cross-sectional area that increases along the nozzle's longitudinal axis and thus widens radially outwards. In combination with a radially outward-extending flow guide element of the first air duct, the outer air duct section can be bounded (radially outward) by the flow guide element and (radially inward) by the diffuser section. The outer air duct section can then also point radially outwards. In particular, the outer air duct section can also be designed as an annular gap in the region of the nozzle end.

[0030] The portion of the air outlet defined by the inner air duct section can have a cross-sectional area (through which air flows) at the nozzle end that is at least 8 times, and in particular at least 10 times, larger than the cross-sectional area (through which air flows) of that portion of the first air outlet defined by the outer air duct section. The central, inner air duct section thus defines a significantly larger cross-sectional area of ​​the air outlet than the outer air duct section, which is separated from the inner air duct section by the diffuser section and is radially annular and located on the outside.

[0031] In one embodiment, an axially flowable flow element can be provided to homogenize the partial airflow in the inner air duct section. This flow element is located within the pipe section of the flow divider. For example, an embodiment with a flow divider in the central / middle first air duct ensures that an unswirled airflow is also generated into the combustion chamber via this central air duct. Consequently, in such an embodiment, the first central air duct is also designed without swirl elements. Therefore, no swirl elements are provided on any centrally arranged flow element within a pipe section of a flow divider.

[0032] The first and second air outlets and the fuel outlet are located in a radial plane perpendicular to the nozzle's longitudinal axis. In this embodiment, the individual outlets are therefore not axially offset from one another. In contrast, the next embodiment features axially offset outlets. In this case, the more radially outward each outlet is located, the further downstream it is axially positioned. Thus, an innermost outlet, for example, a central one, or a portion thereof, is axially set back from a radially outermost outlet and therefore positioned further upstream.

[0033] The proposed solution further includes an engine with at least one embodiment of a proposed nozzle assembly.

[0034] The attached figures illustrate possible implementation variants of the proposed solution.

[0035] This shows: Figure 1A shows a section of the end of a nozzle of a first embodiment of a proposed nozzle assembly; Figure 1B is a sectional view of the nozzle of the Figure 1A Figure 1C shows a further sectional view of a further development of the nozzle of the Figure 1A and 1B illustrating an impact cooling system for a central stabilizing body and a fluid guide for hydrogen to a radially outer fuel channel; Figure 2A in perspective view and partial view of a nozzle of another embodiment of a proposed nozzle assembly; Figure 2B Sectional view of the nozzle of the Figure 2A Figure 3A: A view of a nozzle of another embodiment of a proposed nozzle assembly, looking at one nozzle end; Figure 3: Sectional view of the nozzle of the Figure 3Ain an installed state; Figure 4A shows a perspective view and a section of another embodiment of a proposed nozzle assembly, in which - analogous to the embodiment of the Figure 3A and 3B - a central first air duct is provided, but in contrast to the design variant of the Figure 3A and 3B An undistorted airflow is generated in a combustion chamber, and a flow divider is integrated towards one nozzle end of the nozzle; Figure 4: Sectional view of the embodiment of the Figure 4A Figures 5A-5Bin with the Figures 4A and 4B concurring views, a further development of the execution variant of Figures 4A and 4B with axially offset outlet openings; Figure 6A an engine in which a variant embodiment of a proposed nozzle assembly is used; Figure 6B a section and on an enlarged scale of the combustion chamber of the engine of the Figure 6A .

[0036] The Figure 6AFigure 1 schematically illustrates a (turbofan) engine T in a sectional view, where the individual engine components are arranged sequentially along a rotational or central axis M, and the engine T is designed as a turbofan engine. Air is drawn in at an inlet or intake E of the engine T along an entry direction by means of a fan F. This fan F, located in a fan housing FC, is driven by a rotor shaft S, which is set in rotation by a turbine TT of the engine T. The turbine TT is connected to a compressor V, which, for example, comprises a low-pressure compressor 111 and a high-pressure compressor 112, and optionally a medium-pressure compressor. The fan F supplies air to the compressor V in a primary airflow F1 and, to generate thrust, also supplies air to a secondary airflow channel or bypass channel B in a secondary airflow F2.The bypass channel B runs around a core engine comprising the compressor V and the turbine TT, which includes a primary flow channel for the air supplied to the core engine by the fan F.

[0037] The air conveyed via compressor V into the primary flow channel enters a combustion chamber assembly BK of the core engine, where the drive energy for turbine TT is generated. Turbine TT comprises a high-pressure turbine 113, an (optional) intermediate-pressure turbine 114, and a low-pressure turbine 115. Turbine TT uses the energy released during combustion to drive the rotor shaft S and thus the fan F, which in turn generates the required thrust via the air conveyed into bypass channel B. Both the air from bypass channel B and the exhaust gases from the primary flow channel of the core engine exit through an outlet A at the rear of the engine T. Outlet A typically features a thrust nozzle with a centrally located exhaust cone C.

[0038] The Figure 6BFigure 1 shows a longitudinal section through the combustion chamber assembly BK of engine T. In particular, a (ring) combustion chamber 103 of engine T is visible. A nozzle assembly is provided for injecting fuel or an air-fuel mixture into a combustion chamber 1030 of combustion chamber 103. This assembly comprises a combustion chamber ring R, on which several nozzles D are arranged along a circular path around the central axis M at a combustion chamber head. One or more burner seals BD with bearing openings are provided on the combustion chamber ring R, on which the nozzle heads of the respective nozzles D are held, so that fuel can be injected into combustion chamber 103. Each nozzle D includes a flange, via which a nozzle holder DH of the nozzle D is screwed to an outer housing G of combustion chamber 103.

[0039] In order to effectively inject hydrogen as fuel into the combustion chamber 1030 of the combustion chamber 103 via nozzle D, the design variants of the Figures 1A to 3BEach proposed nozzle assembly is configured as follows: the nozzle D has a fuel channel 22 for hydrogen on a nozzle head 2, the fuel outlet of which is located radially, with respect to a longitudinal axis L of the nozzle D, between two air outlets 12 and 23 or 21 and 23. Air can flow into the combustion chamber 1030 via the air guide channels 12 / 21 and 21 / 23, respectively, from a first, radially inner air guide channel 12 or 21 and air from a second, radially outer air guide channel 23.In order to inject the hydrogen and at least the air from the second radially outer air guide channel 23 with a comparatively high flow velocity and low turbulence, at least the second radially outer air guide channel 23 is provided to supply an undisturbed airflow into the combustion chamber 1030 and the fuel channel 22 is provided to supply an undisturbed flow of hydrogen into the combustion chamber 1030.

[0040] While in the design variants of the Figures 1A to 1C and 2A to 2B In the embodiment of the Figures 3A to 3Ba nozzle D in which the first air guide channel 12 is designed to run centrally along the nozzle longitudinal axis 11 and provides a swirled airflow by means of a swirl element 120.

[0041] As seen in the overall view of the Figure 1A , 1B and 1C As illustrated, one embodiment of a proposed nozzle assembly shown here provides a nozzle D in which hydrogen can be guided via a central fuel supply line 11 extending along the nozzle's longitudinal axis L in a nozzle main body 1 towards a nozzle head 2 at the nozzle end. According to the sectional view of the Figure 1CThis central fuel supply line 11 leads into a cavity 102 of a stabilizing body 10. The cavity 102 is part of a fluid guide for the hydrogen to be injected, which is guided radially outwards from the cavity 102 via fluid lines in radially extending struts 24 to a fuel channel 22 which has an annular cross-section.

[0042] The stabilizing body 10 has a [feature / characteristic] in the Figure 1AThe front view shows a substantially flat end face 100, which faces the combustion chamber 1030. This end face 100 is circular and occupies a large part of the cross-sectional area of ​​the nozzle head 2. Hydrogen and air are thus injected unmixed into the combustion chamber 1030 via the first and second air guide channels 21 and 23, each designed as annular gaps, and the intervening fuel channel 22, which is also designed as an annular gap. The injection point is located relatively radially far outside the nozzle's longitudinal axis L. This results in a stable flame downstream of the nozzle tip and, in particular, not in the immediate vicinity behind the nozzle D. This is advantageous, especially considering the relatively high flammability of hydrogen, in order to keep combustion temperatures lower in the immediate vicinity behind the nozzle D.

[0043] Furthermore, the stabilizer 10 can be used for (pre-)evaporation of the hydrogen to be injected via the hydrogen carried therein. The hydrogen carried to the stabilizer 10 for (pre-)evaporation can simultaneously serve to cool the stabilizer 10 and, in particular, its end face 10 facing the combustion chamber.

[0044] In the illustrated embodiment, hydrogen flows through the central fuel supply line 11 against a rear wall 101 of the stabilizer body 10, which faces away from the combustion chamber 1030 and towards the cavity 102. The rear wall 101, and thus the stabilizer body 10, is therefore cooled by the hydrogen flowing into the cavity 101. The hydrogen is then deflected between a tubular end piece 110 of the central fuel supply line 11 and the inner walls of the cavity 102 on the stabilizer body side and guided radially outwards. Here, the hydrogen reaches the fuel channel 23 via one or more fluid lines in circumferentially distributed struts 24. Each strut 24 can encompass one or more fluid lines.

[0045] In the illustrated embodiment, each strut 24 has a first strut section 24.1 extending radially through the first air guide channel 21, which is partially bounded radially on the inner side by an outer surface of the stabilizing body 10. A second strut section 24.2 of the strut 24, located further radially outwards and in which no hydrogen supply line is provided, extends radially through the second air guide channel 23. The circumferentially distributed struts 24 thus hold the nozzle-head-side air guide channels 21, 23 and the fuel channel 22 to the stabilizing body 10 and thus to the main nozzle body 1.

[0046] As can be seen in particular from the sectional view of the Figure 1BAs can be seen, both the first and second air guide channels 21 and 23, as well as the fuel channel 22, each have a channel section towards the nozzle end with the respective air outlet or fuel outlet opening, which runs at an angle α to the nozzle longitudinal axis L, in the range of 35° to 50°. The airflows from the air guide channels 21 and 23, as well as the hydrogen flow from the fuel channel 22, are thus directed relatively strongly radially outwards, thereby promoting the formation of a recirculation zone as far downstream from the nozzle end as possible.

[0047] Furthermore, the first and second air guide channels 21 and 23 are exemplified here by means of two channel sections 21A, 21B or 23A, 23B, which follow one another in the direction of airflow along the nozzle longitudinal axis L. A first channel section 21A and 23A runs essentially parallel and straight to the nozzle longitudinal axis L. The subsequent (second) channel section 21B and 23B then extends radially outwards at an angle α, and also tapers towards the respective air outlet opening.

[0048] According to the sectional view of the Figure 1BFor example, the second duct section 21B of the first air duct 21 tapers from a gap width / duct height a11 to a gap width / duct height a12 at the corresponding first air outlet opening. The second duct section 23B of the second air duct 23 tapers again to almost the same extent from a duct height a21 to a duct height a22 at its second air outlet opening. The ratios a11:a12 and a21:a22 of the duct heights (and thus correspondingly the ratios of the cross-sectional area flowed through at the inlet and outlet) are in the range of 1.5:1 to 3:1, particularly in the range of 1.7:1 to 2.3:1. The duct height a12 or a22 at the respective air outlet opening is therefore at least a factor of 1.5 or even a factor of 3 lower than the duct height a11 or a21 at the air inlet to the second duct section 21B or 23B.Consequently, the cross-sectional area flowed through from the inlet to the outlet of the respective second channel section 21B or 23B is also reduced by a factor in the range of 1.5 to 3.

[0049] This accelerates the respective airflow until it enters the combustion chamber 1030, without the need for a swirl element and thus without any swirling of the air within the respective air guide channels 21 and 23. The air is therefore introduced into the combustion chamber 1030 via the two air guide channels 21 and 23, which taper towards their respective ends, without any swirling and at a comparatively high axial flow velocity. The same applies to the hydrogen injected via the intervening fuel channel 22.

[0050] The representations of Figure 1B and 1CThis further illustrates the comparatively large frontal area 100 of the stabilizing body 10. Thus, the diameter d of the circular frontal area 100 corresponds to at least 20 times, or even at least 30 or 40 times, the duct height a12 or a22 of the first or second air duct 21 or 23. The duct heights a12 and a22 of the air ducts 21 and 23 at the air outlet openings are of the same order of magnitude as the duct height of the fuel duct 22 at its fuel outlet opening. In principle, the duct heights a12 and a22 can be essentially identical or differ from each other by a ratio of up to 1:3.

[0051] From the sectional view of the Figure 1CA further possible development is evident, in which a narrowing can also be provided in a first channel section 21A or 23A of the first or second air duct 21, 23, specifically towards the respective second channel section 21B or 23B. The airflow is then already accelerated.

[0052] The version of the Figure 2A and 2B It agrees in some design details with the various versions of the Figures 1A to 1C in agreement, particularly with regard to the design of the stabilizing body 10 with its essentially flat end face 100 and its impact cooling via centrally supplied hydrogen, which is then guided radially outwards to the fuel channel 22. In the embodiment of the Figure 2A and 2BHowever, the air ducts 21 and 23, as well as the fuel duct 22, are designed with a smaller radial angle extending outwards. Furthermore, only a single duct section, tapering towards the nozzle end, is provided for the first and second air ducts 21 and 23.

[0053] In the version of the Figure 3A and 3B is in contrast to the different versions of the Figures 1A-1C and 2A-2B No central fuel supply line 11 is provided for supplying the hydrogen to the nozzle head 2. Instead, a first air guide channel 12 is formed centrally. The supply of hydrogen to the fuel channel 22, which remains annular in cross-section, takes place in a radially outer section of the main nozzle body 1.

[0054] In contrast to the various versions of the Figures 1A-1C and 2A-2B is via the first air duct 12 of the version variant of the Figures 3A-3BFurthermore, the airflow is not guided to the combustion chamber 1030 without swirling. Rather, the first air guide channel 12 has a swirl element 120 (English: "swirler") upstream of the nozzle end to swirl the incoming air.

[0055] At the end of the central first air duct 12 of the Figures 3A-3BThe air flows into the combustion chamber 1030 with a swirling motion. The first air guide channel 12 also widens radially outwards at its channel end. A flow guide element 121 of the central air guide channel 12, which appears funnel-shaped when viewed from the top of the combustion chamber 1030, runs at an (opening) angle to the nozzle longitudinal axis L, which lies in the region of the angle α at which the fuel channel 22 and the radially outermost, second air guide channel 23 extend radially outwards towards their respective channel ends.The combination of swirling airflow from a central first air duct 12 in combination with non-swirling radially outward injected hydrogen and non-swirling radially outward flowing second airflow from the second air duct 23 has also proven advantageous for operating the engine T with hydrogen, although the airflow from the central air duct 12 is injected into the combustion chamber 1030 with a lower axial flow velocity than the air from a first air duct 21 of the . Figures 1A-1C and 2A-2B . also in the construction of the Figures 3A-3B A recirculation zone is formed in a central area downstream of nozzle D and especially nozzle head 2. The swirl additionally ensures that the flow opens outwards.

[0056] In the various versions of the Figures 4A-4B and 5A-5B is analogous to the variant of the Figure 3A and3B A central first air guide channel 12 is also provided at nozzle D for an airflow into the combustion chamber 1030. In the design variants of the Figures 4A-4B and 5A-5B However, the air from the central first air guide duct 12 is also introduced into the combustion chamber 1030 without twisting.

[0057] In each of the design variants, the Figures 4A-4B and 5A-5BWithin the first air duct 12, a flow divider 122 is provided towards the nozzle end of the nozzle D. This flow divider 122 splits the airflow within the first air duct into two partial airflows: an inner partial airflow and an outer partial airflow. For this purpose, the flow divider 122 comprises a pipe section 122a with a constant cross-sectional area and a diffuser section 122b extending downstream from it. The diffuser section 122b widens radially towards the nozzle end, so that its cross-sectional area increases continuously along the nozzle's longitudinal axis L. An inner air duct section 12.2 is defined within the pipe section 122a and the diffuser section 122b. An outer air duct section 12.1 is defined between a radially outer surface of the flow divider 122 and an inner surface of a channel wall of the first air duct 12.Towards the nozzle end, the section of the outer air duct part 12.1 is then bordered (radially outwards) by the flow guide element 121 and (radially inwards) by the widening diffuser part 122b. Thus, the outer air duct part 12.1 points radially outwards and defines an annular gap at the nozzle end for the partial airflow to be introduced through it. The channel height of this annular gap is essentially on the order of the fuel outlet opening of the fuel channel 22 and the (second) air outlet opening of the radially outermost air duct 23.

[0058] From the sectional views of the Figure 4B and 5BFurthermore, not only is a strut 220 visible, extending radially outwards within the respective fuel channel 22, but also, and more importantly, the geometry of the respective flow divider 122. In addition, a longitudinally extended central flow body 123 is visible, located cone-shaped in the center of the pipe section 122a. This flow body 123 can be axially circumscribed within the respective pipe section 122a, so that within the pipe section 122a there is a cross-sectional area through which the flow is only annular in cross-section. This contributes to the homogenization of the undistorted inner partial airflow from the inner air guide duct section 12.2, via which the resulting fuel-air mixture is to be leaned out in the near field of the nozzle D.Therefore, additional air is introduced centrally along the nozzle longitudinal axis L to prevent combustion immediately downstream of the nozzle end and thus avoid unwanted heating of the nozzle D.

[0059] The design variants of Figures 4A-4B and 5A-5B They differ primarily in the design of the nozzle end and in the design of the flow divider 122 within the central first air guide channel 12.

[0060] Thus, in the version of the Figures 4A and 4B The outlet openings of the air guide channels 12 and 23 and of the fuel channel 22 are not axially offset from each other and thus lie in a radial plane perpendicular to the nozzle longitudinal axis L, as is also the case with the design variants of the Figures 1A to 3B This is the case. Accordingly, the diffuser part 122b of the flow divider 22 also extends axially to this radial plane.

[0061] In the version of the Figures 5A and 5BIn contrast, an axial offset is provided between the outlet openings. The further radially inward the respective outlet opening is located, the further it is set back relative to the radially outermost and thus axially most projecting outlet opening of the second air duct 23, and therefore further upstream. For example, the portion of the air outlet opening of the first air duct 12, which is defined by the inner air duct section 12.2, is located axially furthest upstream. The diffuser section 122b thus exhibits a different design compared to the variant of the Figures 4A and 4B in the version of the Figures 5A and 5Ba shorter axial length. The cross-sectional area through which the air flows through the part of the air outlet opening of the first air duct 12 defined by the inner air duct section 12.2 is therefore still larger by a factor of at least 8 than the cross-sectional area of ​​the part of the air outlet opening defined by the outer air duct section 12.1, but significantly smaller than in the embodiment of the Figures 4A and 4B . The positioning of the outlet openings and in particular their possible axial offset can vary depending on an application scenario and thus on an engine T and / or, for example, depending on a desired flow pattern of the fuel-air mixture into the combustion chamber 1030.

[0062] The nozzle D of the design variants of the Figures 1A-1C , 2A-2B , 3A-3B , 4A-4B and 5A-5BFurthermore, each nozzle is designed and intended for rich quench lean combustion. In principle, the nozzle D shown can also be used for lean combustion concepts.

[0063] It is understood that the proposed solution is not limited to the embodiments described above and that various modifications and improvements can be made without deviating from the concepts described herein. Any of the features can be used separately or in combination with any other features, provided they are not mutually exclusive, and the disclosure extends to and includes all combinations and subcombinations of one or more features described herein.

Claims

1. Nozzle assembly for a combustion chamber (103) of an engine (T), comprising at least one nozzle (D) for injecting hydrogen into a combustion space (1030) of the combustion chamber (103), the nozzle (D) comprising a nozzle main body (DH) extending along a nozzle longitudinal axis (L) and a nozzle head (2) at one end of the nozzle main body (DH), wherein - at least one first air channel (12; 21) is provided to guide a first air flow in the direction of the combustion space (1030) and to guide it via at least one first air outlet opening of the first air channel (12; 21) into the combustion space (1030), - at least one fuel channel (22) is provided on the nozzle head (2) to guide hydrogen in the direction of the combustion space (1030), and - at least one second air channel (23) is provided to guide a second air flow in the direction of the combustion space (1030) and to guide it via at least one second air outlet opening of the second air channel (22) into the combustion space (1030), wherein the fuel channel (22) is arranged with a fuel outlet opening for the hydrogen to be injected into the combustion space (1030), with respect to a radial direction running perpendicular to the nozzle longitudinal axis (L), between the first and second air channels (12, 23; 21, 23) with their first and second air outlet openings, wherein the first and second air outlet openings and the fuel outlet opening lie in a radial plane running perpendicular to the nozzle longitudinal axis (L) or are axially offset from one another in such a way that the respective outlet opening is arranged axially further downstream the further it lies radially outwards, wherein the nozzle is configured such that hydrogen and air are delivered unmixed, i.e. without mixing inside the nozzle, into the combustion space, and wherein at least the second air channel lying further radially outwards (23) is configured and provided to provide a swirl-free air flow into the combustion space (1030) and the fuel channel (22) is configured and provided to provide a swirl-free flow of hydrogen into the combustion space (1030).

2. Nozzle assembly according to claim 1, characterised in that at least the second air channel lying further radially outwards (23) and the fuel channel (22) run radially outwards at their respective channel ends, the second air channel lying further radially outwards (23) comprising a channel section (23B) which has the second air outlet opening and runs at an angle (α) in the range from 30° to 60° to the nozzle longitudinal axis (L), and / or the fuel channel (22) comprises a channel section (22B) which has the fuel outlet opening and runs at an angle (α) in the range from 30° to 60° to the nozzle longitudinal axis (L).

3. Nozzle assembly according to claim 1 or 2, characterised in that the fuel channel (22) and / or the second air channel lying further radially outwards (23) taper towards a respective channel end.

4. Nozzle assembly according to any of the preceding claims, characterised in that a central fuel supply line (11) is provided in the nozzle main body (1) for supplying hydrogen to the fuel channel (22) and at least one fluid guide is provided on the nozzle head (2), via which the hydrogen can be guided from the fuel supply line into the fuel channel lying further radially outwards (22).

5. Nozzle assembly according to claim 4, characterised in that at least a part of the fluid guide is provided within a radially outwardly extending strut (24) of the nozzle head (2), which extends through a section of the first air channel (21).

6. Nozzle assembly according to any of the preceding claims, characterised in that a stabilisation body (10) which comprises a substantially planar end face (100) facing the combustion space (1030) is provided centrally at one nozzle end of the nozzle (D) and the stabilisation body (10) defines with an outer lateral surface at least a part of an inner wall of the first radially inner air channel (21).

7. Nozzle assembly according to claim 6, characterised in that the stabilisation body (10) defines with its outer lateral surface a radially outward-facing inner wall section (10B) for the first air channel (21), so that the first air channel (21) runs radially outwards at its channel end.

8. Nozzle assembly according to claim 6 or 7, characterised in that the first radially inner air channel (21) tapers towards its channel end.

9. Nozzle assembly according to any of claims 6 to 8, characterised in that the substantially planar end face (100) of the stabilisation body (10) facing the combustion space (1030) has an extent in a radial direction with respect to the nozzle longitudinal axis (L) which corresponds to at least twenty times, in particular at least thirty or twenty times, a channel height (a12) of the first air channel (21) at the first air outlet opening and / or a channel height (a22) of the second air channel (23) at the second air outlet opening and / or a channel height of the fuel channel (22) at the fuel outlet opening.

10. Nozzle assembly according to any of claims 6 to 9, characterised in that cooling is provided for the stabilisation body (10).

11. Nozzle assembly according to claim 4 or 5 and any of claims 6 to 10, characterised in that at least a part of the fluid guide is provided within the stabilisation body (10), wherein the part of the fluid guide provided within the stabilisation body (10) is also provided for cooling the stabilisation body (10).

12. Nozzle assembly according to claim 11, characterised in that for impingement cooling of the stabilisation body (10) with hydrogen, hydrogen is guided via the part of the fluid guide provided within the stabilisation body (10) against a rear wall (101) of the stabilisation body (10) facing away from the combustion space (1030).

13. Nozzle assembly according to any of claims 1 to 3, characterised in that the first air channel (12) is provided running centrally on the nozzle main body (1) along the nozzle longitudinal axis (L) and a fuel supply line for the fuel channel (22) is provided in the nozzle main body (1) in a radially outer section of the nozzle main body (1).

14. Nozzle assembly according to claim 13, characterised in that the first air channel (12) widens at its channel end having the first air outlet opening and forms a radially outwardly extending flow guiding element (121) for this purpose.

15. Nozzle assembly according to claim 13 or 14, characterised in that the first air channel (12) has at least one swirl element (120) for swirling the air flow provided via the first air channel (12) into the combustion space (1030).

16. Nozzle assembly according to claim 13 or 14, characterised in that a centrally arranged flow divider (122) is provided in the first air channel (12), via which an air flow in the first air channel (12) to a nozzle end of the nozzle (D) is divided into an inner and outer air channel part (12.1, 12.2).

17. Nozzle assembly according to claim 16, characterised in that the flow divider (122) has a pipe section (122a) with a constant cross-sectional area along the nozzle longitudinal axis (L) and a diffuser part (122b) which adjoins the pipe section (122) towards the nozzle end and has a cross-sectional area which increases along the nozzle longitudinal axis (L), and the flow guiding element (121) and the diffuser part (122b) border the outer air channel part (12.1), which faces radially outwards.

18. Nozzle assembly according to any of claims 16 or 17, characterised in that at the nozzle end, that part of the first air outlet opening which is defined by the inner air channel part (12.2) has a cross-sectional area which is greater by at least a factor of 8, in particular by at least a factor of 10, than the cross-sectional area of that part of the first air outlet opening which is defined by the outer air channel part (12.1).

19. Nozzle assembly according to any of claims 17 or 18, characterised in that an axially flowable flow body (123) is provided centrally in the pipe section (122a).

20. Engine having at least one nozzle assembly according to any of the preceding claims.