Nozzle cap for a fuel injection nozzle operable in a hydrogen internal combustion engine

Abstract

The invention relates to a nozzle cap (100) for a fuel injection nozzle operable in a hydrogen internal combustion engine (2), the nozzle cap comprising an inlet (104) for receiving a hydrogen gas flow, the hydrogen gas flow being controllable by an inlet valve (106) arrangeable in the inlet, at least one outlet (108) for providing an outlet hydrogen gas flow, and an internal bottom flow guiding body (109) arranged at a bottom side (110) of the nozzle cap downstream of the inlet in a nozzle cap volume (111), the internal bottom flow guiding body protruding towards the inlet and comprising a flow guiding surface (112) for redirecting the hydrogen gas flow from the inlet towards the outlet. The invention further relates to a fuel injection nozzle comprising an inlet valve and a nozzle cap, a hydrogen internal combustion engine (2) comprising a fuel injection nozzle, and a vehicle comprising such a fuel injection nozzle or such a hydrogen internal combustion engine.

Description

Technical Field

[0001] This disclosure relates to a nozzle cap for a fuel injection nozzle operable in a hydrogen internal combustion engine. The disclosure also relates to a corresponding fuel injection nozzle, a hydrogen internal combustion engine, and a vehicle. While the invention will be described with reference to truck-type vehicles, it can also be effectively incorporated into other types of transportation, such as buses and construction equipment, as well as for marine applications, generator set applications, and passenger cars. Background Technology

[0002] Hydrogen injectors used in hydrogen engines typically operate under critical conditions, where the hydrogen flow becomes sonic or even locally supersonic. One problem with this type of flow is the difficulty in maintaining the initial direction of the jet ejected from the injector nozzle.

[0003] A commonly used hydrogen nozzle is the so-called needle valve nozzle. The angle of the upper part of the needle valve surface is a design parameter that determines the outflow direction of the jet. To further control the outflow direction of the jet, the needle valve can be combined with a nozzle cap. The cap includes one or more orifices, and the configuration of these orifices is typically used to determine the direction of the outflowing jet.

[0004] A particular challenge with hydrogen nozzles is that the nozzle cap orifice outlet area needs to be larger than that of conventional engine nozzles. This means that a significant portion of the nozzle cap's sides and bottom is an opening. Therefore, designing the orifice to guide the jet in the desired direction is difficult, especially with sonic or even locally supersonic hydrogen flow. Furthermore, this can lead to turbulent vortices within the cap volume. These turbulent vortices may redirect some of the airflow in an unfavorable direction. Additionally, the cap volume itself may contain residual hydrogen-containing gas, which could potentially ignite spontaneously under adverse conditions.

[0005] Therefore, there is room for improvement in the guidance of hydrogen flow in hydrogen nozzles. Summary of the Invention

[0006] The object of the present invention is to provide a nozzle cap for a fuel injection nozzle that at least partially alleviates the shortcomings of the prior art.

[0007] According to a first aspect of the invention, the object is achieved by the nozzle cap according to claim 1.

[0008] According to a first aspect of the invention, a nozzle cover for a fuel injection nozzle operable in a hydrogen internal combustion engine is provided. The nozzle cover includes an inlet for receiving a hydrogen flow, the hydrogen flow being controllable by an inlet valve disposed in the inlet. At least one outlet is provided for supplying an outlet hydrogen flow, and an internal bottom guide body is disposed on the underside of the nozzle cover downstream of the inlet in the nozzle cover volume. The internal bottom guide body protrudes toward the inlet and includes a guide surface for redirecting the hydrogen flow from the inlet toward the outlet.

[0009] This invention is based on the understanding that, in order to minimize the circulating flow in the nozzle cap, the internal structure and surface of the nozzle cap can be modified to guide the hydrogen gas flow toward the nozzle cap outlet while reducing eddies in the internal volume of the nozzle cap. An advantageous internal structure is an internal bottom guide body that defines a guide surface in contact with the hydrogen gas flow. This internal bottom guide body advantageously guides the hydrogen gas toward the outlet while reducing the dead volume in the cap, which reduces the amount of residual hydrogen that can be retained in the nozzle cap.

[0010] Therefore, by providing the nozzle cap proposed herein, the hydrogen flow is directed toward the outlet, enabling efficient hydrogen injection for hydrogen internal combustion engines.

[0011] The inlet valve that can be arranged in the inlet of the nozzle cap can be, for example, a needle valve known in the art itself, but other types or valves are also conceivable.

[0012] The nozzle cap outlet directs the hydrogen flow into or toward the combustion chamber of the hydrogen internal combustion engine.

[0013] In one embodiment, the outlet may include a first outlet surface and a second outlet surface forming the outlet, wherein the shape of the first outlet surface substantially conforms to the shape of the second outlet surface, such that the outlet hydrogen flow direction at the first outlet surface is substantially the same as the outlet hydrogen flow direction at the second outlet surface. Therefore, the outlet surface is adapted to further improve the guidance of the hydrogen flow. The outlet surface is intentionally shaped in this way to control the outlet direction of the hydrogen flow. The first and second outlet surfaces can be considered as the orifice edge surfaces of the outlet. "Substantially the same outlet flow direction" should be understood as the mainstream flow directions being the same or nearly the same, allowing for small deviations.

[0014] In one embodiment, the nozzle cap may further include at least one first inner guide body disposed on a sidewall surface of the nozzle cap and projecting inward within the nozzle cap volume for guiding the hydrogen flow toward at least one outlet. This further improves the guidance of the hydrogen flow. The at least one inner guide body provides at least one additional guiding surface that helps reduce eddies within the nozzle cap volume by aiding in guiding the hydrogen flow toward the outlet. The first inner guide body cooperates with an inner bottom guide body to guide the hydrogen flow toward the outlet.

[0015] In one embodiment, the outlet may include a first outlet surface and a second outlet surface forming the outlet, wherein the shape of at least one first inner guide body substantially follows the shape of the guide surface of the inner bottom guide body, such that the outlet hydrogen flow at the first outlet surface and the outlet hydrogen flow at the second outlet surface are substantially in the same direction. "Substantially in the same direction" should be understood as the mainstream flow directions being the same or nearly the same, allowing for small deviations. Therefore, the first inner guide body and the inner guide body advantageously cooperate to better guide the hydrogen flow toward the outlet.

[0016] The shape of the outlet along the flow direction can be such that the first outlet surface and the second outlet surface are parallel. However, other outlet shapes or configurations are also possible. For example, in one embodiment, the outlet includes a first outlet surface and a second outlet surface forming the outlet, wherein the first outlet surface and the second outlet surface together form a conical outlet.

[0017] In one embodiment, the outlet may include a first outlet surface and a second outlet surface, wherein the guide surface of the inner bottom guide body is arranged adjacent to the second outlet surface, and the guide surface and the second outlet surface are configured to cooperatively guide the outlet hydrogen flow at the second outlet surface in the same direction as the outlet hydrogen flow at the first outlet surface. Thus, the nozzle cap is further modified to guide the hydrogen flow towards the outlet. The arrangement of the inner bottom guide body adjacent to the second outlet surface means that they are directly adjacent, i.e., next to each other. The guide surface of the inner bottom guide body and the second outlet surface may form a single seamless guide surface.

[0018] In one embodiment, the internal bottom guide body can be configured to redirect the hydrogen flow toward two opposite sides of the nozzle cap. These opposite sides can be located on either side of the central axis of the nozzle cap. This is advantageous if, for example, the nozzle cap includes outlets on both opposite sides.

[0019] In one embodiment, the nozzle cap may include two outlets disposed on opposite sides of an internal bottom flow guide body, wherein the internal flow guide body is configured to redirect the hydrogen flow from the inlet toward the two outlets.

[0020] In one embodiment, the inner bottom guide body can be shaped to fill the volume between the two outlets in the nozzle cap volume. This reduces the amount of residual hydrogen within the nozzle cap. Furthermore, the crossflow across the nozzle cap between the sides of the two outlets is reduced, resulting in less vortex flow within the nozzle cap.

[0021] In the implementation scheme, the internal bottom guide body can be located at the bottom center of the nozzle cap.

[0022] In other embodiments, the internal bottom guide body can be arranged off-center from the bottom of the nozzle cap.

[0023] Depending on the specific implementation, different offsets and positions of the internal bottom guide body are advantageous. For example, in some implementations, an offset arrangement can be used, such as having only one outlet, to reduce the flow to the side without an outlet. A central position may be advantageous when it is necessary to direct an equal amount of such flow to different sides of the nozzle cap.

[0024] In one embodiment, the inner bottom guide body can be shaped to substantially fill the nozzle cap's opposite side of the outlet. This advantageously reduces the dead volume in the nozzle cap, resulting in a reduction in the amount of residual hydrogen that can be retained in the nozzle cap.

[0025] In one embodiment, there are more than two outlets, wherein the internal bottom guide body includes a set of guide surfaces for redirecting the hydrogen flow toward each of the outlets. Therefore, the internal bottom guide body can be advantageously designed to correspond to the number of outlets, thereby still providing an improved hydrogen flow through the nozzle cap.

[0026] Depending on the current implementation, the nozzle cap may have different external shapes.

[0027] For example, in one embodiment, the inner bottom guide body may have a convex external shape.

[0028] In another embodiment, the inner bottom guide body may have a concave outer shape.

[0029] In one embodiment, the internal bottom guide body includes a guide element projecting from the upper ridge of the internal bottom guide body for further adjustment of the hydrogen flow in the nozzle cap. Thus, the nozzle cap is further modified to guide the hydrogen flow toward the outlet.

[0030] According to a second aspect of the invention, a fuel injection nozzle is provided, comprising an inlet valve and a nozzle cap according to any of the embodiments disclosed herein.

[0031] The effects and features of the second aspect of the invention are largely similar to those described above in conjunction with the first aspect.

[0032] According to a third aspect of the invention, a hydrogen internal combustion engine is provided, comprising a fuel injection nozzle according to the second aspect.

[0033] According to a fourth aspect of the invention, a vehicle is provided comprising a fuel injection nozzle according to the second aspect or a hydrogen internal combustion engine according to the third aspect.

[0034] The effects and characteristics of the third and fourth aspects are largely similar to those described above regarding the first and second aspects.

[0035] Additional features and advantages will become apparent when examined in conjunction with the appended claims and the following description. Those skilled in the art will recognize that different features can be combined to create embodiments different from those described below, without departing from the scope of this disclosure. Attached Figure Description

[0036] The embodiments of the invention cited as examples will be described in more detail below with reference to the accompanying drawings.

[0037] In the attached diagram:

[0038] Figure 1 It is a truck-shaped vehicle according to an exemplary embodiment of the present invention;

[0039] Figure 2A This is a perspective cross-sectional view including a nozzle cap according to an exemplary embodiment of the present invention;

[0040] Figure 2B yes Figure 2A The nozzle cap and valve shown are cross-sectional side views;

[0041] Figure 3 This is a cross-sectional side view including a nozzle cap according to an exemplary embodiment of the present invention;

[0042] Figure 4A This is a perspective cross-sectional view including a nozzle cap according to an exemplary embodiment of the present invention;

[0043] Figure 4B yes Figure 4A The nozzle cap and valve shown are cross-sectional side views;

[0044] Figure 5 This is a cross-sectional side view including a nozzle cap according to an exemplary embodiment of the present invention;

[0045] Figures 6A to 6FConceptually illustrating different types of internal bottom flow guide bodies according to embodiments of the present invention; and

[0046] Figure 7 This is a perspective cross-sectional view of a nozzle cap including an exemplary embodiment of the present invention. Detailed Implementation

[0047] The invention will now be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the invention are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness. Those skilled in the art will recognize that many changes and modifications can be made within the scope of the appended claims. Similar reference numerals throughout this description refer to similar elements.

[0048] Figure 1 A vehicle in the form of a truck 1 is shown, which includes an engine 2, such as an internal combustion engine. The internal combustion engine is a hydrogen engine. Truck 1 may be a hybrid electric vehicle. The hydrogen internal combustion engine 2 of truck 1 also includes fuel injection nozzles having nozzle caps as disclosed herein.

[0049] Figure 2A This is a perspective cross-sectional view of the nozzle cap 100 for the fuel injection nozzle 4, which can be operated in a hydrogen internal combustion engine 2 during use. Figure 2B yes Figure 2A The nozzle cap 100 and valve are shown in cross-section. The nozzle cap 100 includes an inlet 104 for receiving a hydrogen flow. The hydrogen flow is provided by a normally pressurized hydrogen storage tank. The hydrogen flow through the inlet 104 can be controlled by an inlet valve 106 disposed in the inlet 104. When the shaft 107 of the valve 106 is in the upper position, the inlet 104 is closed and hydrogen is not allowed to enter the nozzle cap volume 111. Figures 2A to 2B As shown in the lower position, inlet 104 is open and allows hydrogen to enter the nozzle cover volume 11.

[0050] The nozzle cap 100 also includes at least one outlet 108 for providing an outlet hydrogen flow. An internal bottom guide body 109 is disposed at the bottom side 110 of the nozzle cap 100 downstream of the inlet 104 (e.g., opposite to the inlet 109) in the nozzle cap volume 111. The internal bottom guide body 109 is shaped to protrude toward the inlet 104 and includes a guide surface 112 for redirecting the hydrogen flow received from the inlet 104 to the outlet 108.

[0051] The hydrogen flow enters through inlet 104 and is initially guided by the guide surface 123 and seat 124 of valve 108 before entering nozzle cap volume 111. If the internal bottom guide body 109 were absent, vortices would be generated within the cap, resulting in a suboptimal hydrogen flow toward outlet 108. However, as provided by the embodiments herein, the internal bottom guide body 109 provides improved hydrogen flow guidance toward outlet 108.

[0052] The internal bottom guide body 109 extends along axis 122 from the bottom side 110 toward the inlet side 104. The guide surface 112 of the internal bottom guide body 109 ensures that the flow of hydrogen follows the shape of the guide surface and is guided toward the outlet 104.

[0053] The internal bottom guide body 109 extends relatively closer to the valve 108, which advantageously reduces crossflow of hydrogen through the center 122 of the internal bottom guide body 109 and where the nozzle cap 100 is also located, further improving the guidance of the hydrogen flow. Furthermore, the internal bottom guide body 109 is relatively large, filling most of the nozzle cap volume 111. This reduces the risk of residual hydrogen remaining in the nozzle cap volume 106. Generally, larger is better, but the size should not impair the ability of the internal bottom guide body 109 to guide the hydrogen flow towards the outlet 108. Figures 2A to 2B In the middle, the inner bottom guide body is located in the center of the nozzle cover 100.

[0054] Furthermore, the flow guiding surface 128 adjacent to the valve seat 124 is shaped to guide the flow toward the outlet 108. The flow guiding surface 128 is adjacent to the valve seat 124, such that the flow guiding surface 128 and the valve seat 124 form a continuous flow guiding surface.

[0055] Surfaces 112 and 128 cooperate to aerodynamically guide the flow toward outlet 108. For example, outlet 108 includes a first outlet surface 114 and a second outlet surface 116 forming outlet 108. These surfaces 114 and 116 are the orifice edges of outlet 108. To provide efficient flow through outlet 108, the shape of the first upper outlet surface 114 substantially follows the shape of the second lower outlet surface 116. Thus, the outlet hydrogen flow from outlet 108 at the first outlet surface 114 is in substantially the same direction as the outlet hydrogen flow at the second outlet surface 116. Therefore, the shapes of the guiding surface 112 and the outlet surfaces 112 and 114 can vary depending on the relative positions of outlet 108 and inlet 104, but are adapted to guide the hydrogen flow toward outlet 108. Figure 1 In the nozzle cover, the inner bottom guide body 109 has a convex external shape, thereby forming a ridge. The cross-sectional shape of the guide surface 112 and the second outlet surface 116 of the inner bottom guide body 109 can be bent into an S-shape in both directions.

[0056] Valve seat 124, flow guiding surface 128, and first outlet surface 114 preferably form a continuous, smooth flow guiding surface. Similarly, flow guiding surface 112 and second outlet surface 116 preferably form a continuous, smooth flow guiding surface. The flow guiding surface 128 of cover wall 129 and the flow guiding surface 112 of bottom flow guiding body are smoothly connected through the orifice edges 114, 116.

[0057] Another possibility is that the first and second exit surfaces together form a conical exit.

[0058] The guiding surface 112 of the inner bottom guiding body 109 is arranged adjacent to the second outlet surface 116. Preferably, the guiding surface 112 and the second outlet surface form a seamless guiding surface extending along the inner bottom guiding body 109 to the outlet 108. The guiding surface 112 and the second outlet surface 116 are configured to cooperatively guide the outlet hydrogen flow at the second outlet surface in the same direction as the outlet hydrogen flow at the first outlet surface 116.

[0059] Figure 3 Another embodiment of the invention is conceptually illustrated. This embodiment may be primarily intended for use with a single-hole cap where the main bore direction is at an angle relative to the central axis of the injector. Figure 3 The nozzle cap 300 shown is Figures 2A to 2B The difference in the nozzle cap shown is that the inner bottom guide body 309 is shaped to substantially fill the side 140 of the nozzle cap opposite the outlet 108. In other words, instead of leaving an open volume on the side of the inner bottom guide body 109 without an outlet, the inner bottom guide body 309 is filled. This significantly reduces the amount of residual hydrogen that can be retained in the nozzle cap 300.

[0060] The nozzle cap can have more than one outlet. (Turn) Figures 4A to 4B The image shows a nozzle cap 400 with two outlets 108a to 108b. Figure 4A It is a perspective cross-sectional view of the nozzle cap 400, and Figure 4B This is a cross-sectional view of the nozzle cap 400. The internal bottom guide body 409 is configured to redirect the hydrogen flow towards two opposite sides of the nozzle cap 400, with two outlets located on said two opposite sides. Therefore, the internal bottom guide body 409 includes two opposing guide surfaces 112a and 112b. The first guide surface 112a is configured to guide the hydrogen flow towards a first outlet 108a, and the second guide surface 112b is configured to guide the hydrogen flow towards a second outlet 108b.

[0061] Figure 5Another embodiment of the nozzle cap is conceptually illustrated. Here, the nozzle cap 500 includes an internal bottom guide body 509 as discussed above with reference to the preceding figures, and two outlets 508a to 508b. Furthermore, the nozzle cap 500 includes at least one first inner guide body 518 disposed at a sidewall 520 of the nozzle cap 500 and projecting inwardly within the nozzle cap volume 506 for guiding the hydrogen flow toward the outlets 508a to 508b. Thus, the inner bodies 518 and 509 define outer surfaces 510a to 510b and 521a to 521b, which contact the hydrogen flow and are cooperatively configured to guide the hydrogen flow toward the outlets to reduce eddies in the cap volume 506.

[0062] The first inner guide body 518 is shaped to have a convex outer surface to allow the flow from the inlet to be received and guided along the inner guide body 518 on the surface of the flow guide with the assistance of the inner bottom guide body 509 arranged opposite to the outlets 508a to 508b.

[0063] Preferably, the shape of the surface portion 525 of at least one first inner guide body 521a to 521b substantially follows the shape of the guide surfaces 510a to 510b of the inner bottom guide body, such that the outlet hydrogen flow from the outlet at the first outlet surfaces 512a and 512b is substantially in the same direction as the outlet hydrogen flow at the second outlet surfaces 514a and 514b. Preferably, the shape of the surface portion 525b of the inner guide body 521b adjacent to the second outlet surface 514b is substantially similar to the shape of the surface portion of the inner bottom guide body 509 opposite to the surface portion 525b. Similarly, at the other outlets 108a, the shape of the surface portion 525a of the inner guide body 521a adjacent to the second outlet surface 514a is substantially similar to the shape of the surface portion of the inner bottom guide body 509 opposite to the surface portion 525a.

[0064] Generally, the internal flow guide bodies 509, 521a to 521b are configured to redirect the hydrogen flow from the inlet toward the two outlets 508a to 508b.

[0065] In cases where there are more than two outlets, the internal bottom guide body includes a set of guide surfaces for redirecting the hydrogen flow toward each of the outlets.

[0066] Regarding Figure 4A , Figure 4B and Figure 5Each of the discussed embodiments is advantageous in that the internal bottom guide body is shaped to fill the volume between the two outlets in the nozzle cap volume. Thus, the internal bottom guide body reaches the entire internal volume of the nozzle cap from one side to the other, but keeps the opening open. Furthermore, the internal bottom guide bodies 509, 109 are located at the bottom center of the nozzle cap.

[0067] Figures 6A to 6F The different configurations of the internal bottom airflow guide body are conceptually illustrated. Figures 6A to 6F The diagram illustrates an exemplary height profile and shape of the internal bottom guide body. However, these are merely examples, and variations are possible and within the scope of this invention. The shape of the internal bottom guide body is generally configured to facilitate efficient hydrogen flow in a preferred direction to the nozzle cap outlet.

[0068] Figure 6A These are top views 602 and side views 604 of an internal bottom guide body 600 having a convex external shape. Therefore, the guide surface 606 has a convex shape and is configured to guide the hydrogen flow from the inlet to the outlet, as described herein. Here, the guide surface 606 has a relatively shallow slope. Furthermore, at the side 608, between the internal bottom guide body 600 and the inlet valve shaft ( Figure 6A A channel is formed between (not shown). Axis 2000 indicates the center of the nozzle cap, therefore, the inner bottom guide body 600 is indicated here as being located at the center of the nozzle cap.

[0069] Figure 6B These are the top view 602 and side view 604 of the internal bottom guide body 700, which has a convex external shape, but is similar to... Figure 6A Compared to the internal bottom flow guide body 600 shown, it has a narrower lateral extension. The internal bottom flow guide body 700 is configured as a barrier-type structure, which allows for minimal crossflow between the sides of the internal bottom flow guide body 700.

[0070] Figure 6C These are the top view 602 and side view 604 of the internal bottom guide body 800, which have the same... Figure 6A The internal bottom guide body 600 shown has a similar convex external shape. However, the internal bottom guide body 800 is arranged off-center from the bottom center 2000 of the nozzle cap. Therefore, the internal bottom guide body 800 is positioned such that more hydrogen flow is directed towards the first side 802 of the internal bottom guide body 800 rather than towards the second side 804. In other words, the off-center position of the internal bottom guide body 800 facilitates the direction of hydrogen flow towards the first side 802.

[0071] Figure 6DThese are top views 602 and side views 604 of an internal bottom guide body 900 having a convex external shape. The internal bottom guide body 900 differs from the internal bottom guide body 600 in that the slope of the guide surface 906 is steeper than that of the guide surface 606 of the internal bottom guide body 600. The steeper slope results in a smaller channel 908, which advantageously reduces crossflow through the center 2000 of the nozzle cap.

[0072] Figure 6E These are top views 602 and side views 604 of an internal bottom guide body 1000, which is adapted to fill the side of the nozzle cap opposite the outlet. Therefore, one side of the internal bottom guide body 1000 has a guide surface 1006 adapted to guide the hydrogen flow toward the outlet. The other side of the internal bottom guide body 1000 fills the volume of the nozzle cap on that side. Therefore, the flow rate guided to the filled side of the nozzle cap is very small.

[0073] Figure 6F These are top views 602 and side views 604 of the internal bottom guide body 1100 with a concave external shape. The guide surface 1106 with a concave shape facilitates the guidance of the hydrogen flow toward the center of the outlet 108; in other words, the concave shape of the guide surface 1106 causes the flow to converge toward the center of the outlet 108.

[0074] Figure 7 A conceptual perspective section of a nozzle cap 1300 according to an embodiment of the invention is shown. Here, the inner bottom guide body 1309 includes a guide element 1312 projecting from the upper ridge 1314 of the inner bottom guide body 1309. This allows the hydrogen flow in the nozzle cap to be directed in a preferred direction. The guide element 1312 is particularly adapted to guide a small flow from a valve seat in the region between the nozzle cap outlets 108a, 108b, such that the flow at this location between the outlets is better directed toward the outlets 108a, 108b. Therefore, the guide element 1312 is designed to redirect the traveling flow reaching the bottom guide body 1309 downwards to the location between the outlets 108a, 108b.

[0075] Although other possibilities are conceivable, the nozzle cap is preferably made of steel.

[0076] Although the invention has been described with reference to specific exemplary embodiments thereof, many different changes, modifications, etc., will be apparent to those skilled in the art. Therefore, it should be understood that the invention is not limited to the embodiments shown above and in the accompanying drawings; rather, those skilled in the art will recognize that many changes and modifications can be made within the scope of the appended claims.

Claims

1. A nozzle cap (100) for a fuel injection nozzle operable in a hydrogen internal combustion engine (2), the nozzle cap being characterized in that: An inlet (104) for receiving a hydrogen flow, the hydrogen flow being controllable by an inlet valve (106) disposed in the inlet; At least one outlet (108) for providing an outlet flow of hydrogen gas; and An internal bottom guide body (109) is disposed on the bottom side (110) of the nozzle cover downstream of the inlet in the nozzle cover volume (111). The internal bottom guide body includes a ridge protruding toward the inlet and a guide surface (112) for redirecting the hydrogen flow from the inlet toward the outlet. The ridge is located at the bottom center of the nozzle cover and is arranged to extend from one side to the entire internal volume (111) of the nozzle cover.

2. The nozzle cap according to claim 1, wherein the outlet includes a first outlet surface (114) and a second outlet surface (116) forming the outlet, wherein the shape of the first outlet surface substantially follows the shape of the second outlet surface, such that the outlet hydrogen flow at the first outlet surface and the outlet hydrogen flow at the second outlet surface have substantially the same direction.

3. The nozzle cap according to claim 1, further comprising at least one first inner guide body (518), the at least one first inner guide body being disposed on the sidewall surface of the nozzle cap and protruding inward within the volume of the nozzle cap for guiding the hydrogen flow toward the at least one outlet.

4. The nozzle cap of claim 3, wherein the outlet includes a first outlet surface and a second outlet surface forming the outlet, wherein the shape of the at least one first inner guide body substantially follows the shape of the guide surface of the inner bottom guide body, such that the outlet hydrogen flow at the first outlet surface from the outlet has a substantially the same direction as the outlet hydrogen flow at the second outlet surface.

5. The nozzle cover of claim 1, wherein the outlet includes a first outlet surface and a second outlet surface forming the outlet, wherein the first outlet surface and the second outlet surface together form a conical outlet.

6. The nozzle cap according to any one of claims 1 to 5, wherein the outlet includes a first outlet surface and a second outlet surface, wherein the guide surface of the inner bottom guide body is arranged adjacent to the second outlet surface, and the guide surface and the second outlet surface are configured to cooperatively guide the outlet hydrogen flow at the second outlet surface in the same direction as the outlet hydrogen flow at the first outlet surface.

7. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body is configured to redirect the hydrogen flow toward two opposite sides of the nozzle cap.

8. The nozzle cap according to claim 7, comprising two outlets (108a, 108b) disposed on opposite sides of the inner bottom guide body, wherein the inner bottom guide body (109) is configured to redirect the hydrogen flow from the inlet toward the two outlets.

9. The nozzle cap of claim 8, wherein the inner bottom guide body is shaped to fill the volume between the two outlets in the nozzle cap volume.

10. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body is located at the bottom center of the nozzle cap.

11. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body is arranged off-center from the bottom of the nozzle cap.

12. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body is shaped to fill the side (140) of the nozzle cap opposite to the outlet.

13. The nozzle cap according to any one of claims 1 to 5, wherein the number of outlets is more than two, wherein the inner bottom guide body includes a set of guide surfaces for redirecting the hydrogen flow toward each of the outlets.

14. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body has a convex external shape.

15. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body has a concave outer shape.

16. The nozzle cap according to any one of claims 1 to 5, wherein the inner bottom guide body includes a guide element (1312) protruding from the upper ridge (1314) of the inner bottom guide body for providing further adjustment of the hydrogen flow in the nozzle cap.

17. A fuel injection nozzle comprising an inlet valve and a nozzle cap according to any one of claims 1 to 16.

18. A hydrogen internal combustion engine (2) comprising a fuel injection nozzle according to claim 17.

19. A vehicle (1) comprising a fuel injection nozzle according to claim 17 or a hydrogen internal combustion engine according to claim 18.

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