Engine air inlet unit structure, air inlet combined structure and engine

Abstract

The invention provides an engine air inlet unit structure, an air inlet combined structure and an engine, and the engine air inlet unit structure comprises an air inlet header and an alcohol sprayer. The air inlet header comprises an air inlet pipe section with openings in the two ends and a mixing pipe section communicated with an air inlet pipe section body, the air inlet pipe section extends in the first direction, the mixing pipe section extends in the second direction, and the first direction is perpendicular to the second direction; the end, away from the air inlet pipe section, of the mixing pipe section is in butt joint with an engine cylinder cover. And at least two spraying positions are arranged on the mixing pipe section. And alcohol sprayers are installed at the spraying positions, the multiple alcohol sprayers spray methyl alcohol into the mixing pipe section, and the spraying directions of the multiple alcohol sprayers intersect with one another in the plane perpendicular to the second direction. According to the technical scheme, the alcohol spraying device and the air inlet collecting pipe are integrated into an independent unit module, methanol is prevented from directly corroding the cylinder cover, the cylinder cover improvement difficulty is reduced, the methanol and air mixing path is prolonged, the alcohol spraying device is matched for cross spraying, uniformity is improved, and combustion is optimized.

Description

Technical Field

[0001] The present application relates to the field of engine air intake technology, and in particular to an engine air intake unit structure, an air intake combination structure and an engine. Background Art

[0002] Methanol-fueled engines are internal combustion engines that use methanol as their primary fuel. Their key advantages include minimal modifications to the original engine and minimal environmental pollution. With the decreasing cost of methanol production, marine methanol inlet injection technology has become a key path toward a low-carbon transition for internal combustion engines.

[0003] Currently, there are two approaches to methanol inlet injection technology. The first involves designing the engine cylinder head and intake manifold into a one-piece cast structure, with the alcohol injector positioned at the bottom of the intake manifold within this integrated structure. This approach has the disadvantages of being suitable only for completely new engines designed from scratch and unsuitable for retrofits (which involve minor structural modifications to an existing marine diesel engine, ultimately converting it to a methanol / diesel dual-fuel engine). Furthermore, the design time and cost are relatively high.

[0004] The second approach involves placing the alcohol injector solely above the cylinder head intake duct. This approach has the following drawbacks: the compact cylinder head structure significantly limits the size and placement of the injector. Furthermore, its placement on the cylinder head results in relatively poor mixing uniformity between methanol and air. Furthermore, because the mixing of methanol and air is a complex process, there's a high probability that the methanol injected by the injector will directly impact the cylinder head structure, causing persistent corrosion. Consequently, if corrosion is severe, maintenance can only be achieved by replacing the cylinder head, significantly increasing maintenance costs. Summary of the Invention

[0005] The purpose of this application is to provide an engine intake unit structure, an intake combination structure and an engine, which integrates the alcohol injector and the intake manifold into an independent unit module, avoids direct corrosion of the cylinder head by methanol, reduces the difficulty of cylinder head improvement, extends the methanol and air mixing path, and cooperates with the alcohol injector for cross injection to improve uniformity and optimize combustion.

[0006] In a first aspect, an engine air intake unit structure is provided, comprising an air intake manifold and an alcohol injector.

[0007] The intake manifold comprises an intake pipe section with openings at both ends and a mixing pipe section connected to the intake pipe section body. The intake pipe section extends in a first direction, and the mixing pipe section extends in a second direction, with the first direction being perpendicular to the second direction. The mixing pipe section has an end distal from the intake pipe section for docking with the engine cylinder head. The mixing pipe section is provided with at least two injection positions. Alcohol injectors are mounted at the injection positions, and multiple alcohol injectors inject methanol into the mixing pipe section, with the injection directions of the multiple alcohol injectors intersecting in a plane perpendicular to the second direction.

[0008] In one feasible solution, two injection positions are provided on the mixing pipe section, an alcohol sprayer is installed in each injection position, and the angle between the spray directions of the two alcohol sprayers ranges from 60° to 120°.

[0009] In one feasible solution, the angle between the spraying directions of the two alcohol sprayers is 90°.

[0010] In one feasible solution, an installation channel is provided at the injection position of the mixing pipe section and extends into the interior of the mixing pipe section, and an alcohol sprayer is installed in the installation channel; the alcohol sprayer includes an injection end close to one side of the mixing pipe section and an inlet end away from the mixing pipe section;

[0011] The engine intake unit structure also includes:

[0012] The pressing block is fixedly mounted on one end of the installation channel away from the mixing pipe section and is sealed with the periphery of the inlet end of the alcohol sprayer. The pressing block is provided with a methanol inlet channel that is docked with and communicated with the inlet end of the alcohol sprayer.

[0013] In one feasible solution, the bottom of the pressing block is annular, a first sealing structure is provided between the inner wall of the pressing block and the outer wall of the inlet end of the alcohol sprayer, a second sealing structure is provided between the outer wall of the pressing block and the inner wall of the installation channel, and a third sealing structure is provided between the outer wall of the alcohol sprayer body and the inner wall of the installation channel;

[0014] The first sealing structure, the second sealing structure and the third sealing structure form a closed cavity;

[0015] The installation channel is provided with a first interface and a second interface which are communicated with the closed cavity.

[0016] In one feasible solution, an annular step is provided on the outer wall of the alcohol sprayer near the inlet end, and a predetermined distance is reserved between the end face of the pressure block inserted into the installation channel and the surface of the annular step to form an annular cavity, which is part of the closed cavity.

[0017] In an practicable solution, the first interface and the second interface on the mounting channel are arranged at a height consistent with a height of the annular cavity.

[0018] In one feasible solution, a docking flange for sealing connection with the engine cylinder head is provided at one end of the mixing pipe section away from the intake pipe section.

[0019] In a second aspect, an engine air intake assembly structure is provided, comprising a plurality of the aforementioned engine air intake unit structures and a connector, wherein the air intake pipe sections of the air intake manifolds of the plurality of engine air intake unit structures are connected end to end in sequence via the connector.

[0020] In a third aspect, an engine is provided, comprising a cylinder head and the aforementioned engine intake assembly structure. The cylinder head has a plurality of intake ports reserved thereon. The mixing pipe section of the intake manifold of the engine intake assembly structure is connected to the intake ports on the cylinder head.

[0021] Compared to existing technologies, the present invention offers at least the following advantages: In this engine intake unit structure, the mixing pipe section of the intake manifold is detachably connected to the cylinder head, while the alcohol injector is directly mounted on the mixing pipe section. This removes the methanol injection and air mixing functions from the cylinder head, forming a standalone unit. Compared to traditional designs where the cylinder head and intake pipe section are integrally molded, this structure eliminates the need for extensive redesign and significantly reduces the difficulty of casting and machining.

[0022] Because the alcohol injector is no longer installed in the cylinder head but is instead integrated into the intake manifold, even if a trace of methanol leaks, the corrosion risk is limited to the intake manifold itself, preventing damage to the cylinder head. As a separate component, the intake manifold is simple and cost-effective to replace and maintain even if it corrodes. Furthermore, the placement of the alcohol injector in the mixing pipe section of the intake manifold provides a longer mixing path and a larger mixing volume for methanol and air compared to solutions installed in the cylinder head, significantly improving mixing uniformity and resulting in enhanced combustion quality.

[0023] Furthermore, the multiple alcohol injectors arranged on the mixing pipe section have injection directions that intersect with each other in a plane perpendicular to the second direction L2, forming a three-dimensional mixing atomization field, further enhancing the mixing quality of methanol and air, and providing a guarantee for efficient and stable combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a three-dimensional diagram of an engine air intake unit structure shown in an embodiment of the present application.

[0026] Figure 2 for Figure 1 Front view of the injection end of the engine intake unit structure.

[0027] Figure 3 for Figure 1 Side view of the engine intake unit structure.

[0028] Figure 4 for Figure 3 Cross-sectional view along AA.

[0029] Figure 5 for Figure 1 A top view of the intake manifold of the engine intake unit structure.

[0030] Figure 6 for Figure 5 Cross-sectional view along BB.

[0031] Figure 7 for Figure 5 Cross-sectional view along CC.

[0032] Figure 8 for Figure 1 Structural diagram of the compression block of the engine intake unit structure.

[0033] Figure 9 for Figure 8 Cross-sectional view of the medium pressure block structure.

[0034] Figure 10 for Figure 1 Structural diagram of the alcohol injector in the engine intake unit structure.

[0035] Figure 11 for Figure 4 Cross-sectional structural diagram of the alcohol sprayer on one side.

[0036] Figure 12 for Figure 11 An enlarged view of the local structure of the annular cavity between the middle alcohol sprayer and the pressing block.

[0037] Figure 13 for Figure 1 Front view of the injection end of the engine intake unit structure.

[0038] Figure 14 for Figure 13 Cross-sectional view along DD.

[0039] In the figure: 100, engine intake unit structure; 1, intake manifold; 11, intake pipe section; 12, mixing pipe section; 121, docking flange; 13, installation channel; 2, alcohol injector; 21, annular step; 3, pressing block; 31, methanol inlet channel; 32, wiring harness channel; 41, first sealing structure; 42, second sealing structure; 43, third sealing structure; 44, annular cavity; 51, methanol fuel inlet pipe; 52, purge inlet pipe; 53, purge outlet pipe; L1, first direction; L2, second direction. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0042] like Figures 1 to 7 As shown, an embodiment of the present application first provides an engine air intake unit structure, characterized in that it includes an air intake manifold 1 and an alcohol injector 2.

[0043] The intake manifold 1 comprises an intake pipe section 11 with openings at both ends and a mixing pipe section 12 connected to the main body of the intake pipe section 11. The intake pipe section 11 extends along a first direction L1, and the mixing pipe section 12 extends along a second direction L2, with the first direction L1 and the second direction L2 being perpendicular. The end of the mixing pipe section 12, distal from the intake pipe section 11, is designed to interface with the engine cylinder head. The mixing pipe section 12 is provided with at least two injection stations. Alcohol injectors 2 are mounted at these injection stations. Multiple alcohol injectors 2 inject methanol into the mixing pipe section 12, with the injection directions of the multiple alcohol injectors 2 intersecting in a plane perpendicular to the second direction L2.

[0044] It should be noted that the injection position set on the mixing pipe section 12 is the installation position of the alcohol injector 2, and the injection position is provided with at least an opening connected to the interior of the mixing pipe section 12, so that the alcohol injector 2 can spray methanol into the mixing pipe section 12 and mix it with the air delivered by the intake pipe section 11.

[0045] It should also be noted that the mixing tube segment 12 extends along the second direction L2, which can be understood as the axis of the mixing tube segment 12 completely coinciding with the second direction L2; it can also be understood as the axis of the mixing tube segment 12 and the second direction L2 have a certain angle, but its overall extension direction still remains extended in the second direction L2.

[0046] In this embodiment of the engine intake unit structure, the mixing pipe section 12 of the intake manifold 1 is detachably connected to the cylinder head, while the alcohol injector 2 is directly mounted on this mixing pipe section 12. This removes the methanol injection and air mixing functions from the cylinder head, forming a standalone unit. Compared to traditional solutions where the cylinder head and intake manifold section are integrally molded, this structure eliminates the need for extensive redesign and significantly reduces casting and machining complexity.

[0047] Since the alcohol injector 2 is no longer installed in the cylinder head but is instead integrated into the intake manifold 1, even if a trace of methanol leaks, the corrosion risk is limited to the intake manifold 1 itself, preventing damage to the cylinder head. As an independent component, the intake manifold 1 is easy and cost-effective to replace and maintain even if it corrodes. Furthermore, the placement of the alcohol injector 2 in the mixing pipe section 12 of the intake manifold 1 provides a longer mixing path and a larger mixing volume for methanol and air compared to solutions installed in the cylinder head. This significantly improves mixing uniformity and combustion quality.

[0048] Furthermore, the multiple alcohol injectors 2 arranged on the mixing pipe section 12 have injection directions that intersect with each other in a plane perpendicular to the second direction L2, forming a three-dimensional mixing atomization field, further enhancing the mixing quality of methanol and air, improving the mixing effect, and providing a guarantee for efficient and stable combustion.

[0049] Furthermore, this design is compatible with both retrofits and new builds. A retrofit involves modifying the existing marine diesel engine structure to create a methanol / diesel dual-fuel engine. A new build refers to a completely newly designed and manufactured methanol-fueled engine, rather than a minor modification of an existing diesel engine.

[0050] In one embodiment, if Figure 2 As shown, the mixing pipe section 12 is preferably provided with two injection positions, each of which is equipped with an alcohol injector 2. The angle β between the injection directions of the two alcohol injectors 2 ranges from 60° to 120°. For example, the angle β can be 60°, 70°, 80°, 90°, 100°, 110°, 120°, etc.

[0051] In one embodiment, the angle β between the injection directions of the two alcohol sprayers 2 is preferably set to 90°, and the intersection of the center lines of the injection directions of the two alcohol sprayers 2 coincides or approximately coincides with the central axis of the mixing pipe section 12, thereby making the overlapping area of ​​the methanol sprayed from the two alcohol sprayers 2 larger and the contact area with the air larger, thereby helping to improve the mixing uniformity.

[0052] In one embodiment, if Figure 4 and Figure 6 As shown, the injection position of the mixing pipe section 12 is provided with a mounting channel 13 that penetrates into the interior of the mixing pipe section 12, and the alcohol injector 2 is installed in the mounting channel 13; the alcohol injector 2 includes an injection end close to the side of the mixing pipe section 12 and an inlet end away from the mixing pipe section 12. The engine air intake unit structure also includes a pressing block 3, which is fixedly mounted on the end of the mounting channel 13 away from the mixing pipe section 12 and is sealed to the periphery of the inlet end of the alcohol injector 2. The pressing block 3 is provided with a methanol inlet channel 31 that is docked with and connected to the inlet end of the alcohol injector 2. It should be noted that the periphery of the pressing block 3 can be fastened to the peripheral side wall of the mounting channel 13 by fasteners such as bolts and nuts. As shown Figure 2 and Figure 3 As shown, the methanol inlet channel 31 is externally connected to a methanol fuel inlet pipe 51 for transporting methanol.

[0053] In one embodiment, if Figure 8 and Figure 9 As shown, the bottom of the pressing block 3 is annular. Figure 11 and Figure 12 As shown, a first sealing structure 41 is provided between the inner wall of the pressing block 3 and the outer wall of the inlet end of the alcohol sprayer 2, a second sealing structure 42 is provided between the outer wall of the pressing block 3 and the inner wall of the installation channel 13, and a third sealing structure 43 is provided between the outer wall of the alcohol sprayer 2 body and the inner wall of the installation channel 13. The space enclosed by the first sealing structure 41, the second sealing structure 42 and the third sealing structure 43 forms a closed cavity, and the installation channel 13 is provided with a first interface and a second interface communicating with the closed cavity. The first interface and the second interface can be located on opposite sides of the installation channel 13 in a radial direction and arranged relative to each other. Figure 3 、 Figure 13 and Figure 14 As shown, the first interface is connected to the purge air inlet pipe 52 , and the second interface is connected to the purge air outlet pipe 53 .

[0054] In one embodiment, if Figure 10 As shown, at least one first annular groove can be provided on the outer wall of the air inlet end of the alcohol injector 2, and a first O-ring can be installed in the first annular groove. After the pressing block 3 is installed, its inner wall fits tightly with the first O-ring to form a first sealing structure 41.

[0055] In one embodiment, if Figure 8 and Figure 9 As shown, at least one second annular groove can be provided on the annular outer wall at the bottom of the pressing block 3, and a second O-ring can be installed in the second annular groove. After the pressing block 3 is installed, its second O-ring fits tightly with the inner wall of the installation channel 13 to form a second sealing structure 42.

[0056] In one embodiment, if Figure 10 As shown, at least one third annular groove can be provided on the outer periphery of the middle and lower middle parts of the body of the alcohol sprayer 2, and a third O-ring can be installed in the third annular groove. After the alcohol sprayer 2 is installed in the installation channel 13, the inner wall of the installation channel 13 is tightly fitted with the third O-ring to form a third sealing structure 43.

[0057] In one embodiment, a purge device (not shown) and a detection device (not shown) may also be provided. The purge device is connected to the purge inlet pipe 52, and the purge outlet pipe 53 is connected to the detection device. If the first sealing structure 41 fails to a certain extent, resulting in methanol leakage at the air inlet end of the alcohol injector 2, the leaked methanol will enter the closed cavity surrounded by the three sealing structures. The purge device is started from time to time (the purge gas can be nitrogen), see Figure 14 In the direction of the arrow in FIG, the purge gas enters the closed cavity through the purge inlet pipe 52, and is then blown out through the purge outlet pipe 53 and delivered to the detection device to detect the methanol concentration and thus determine whether a leak has occurred. As can be seen, this embodiment, by providing the closed cavity and the first and second interfaces, can not only conveniently detect whether a leak has occurred at the air inlet end of the alcohol injector 2 through the purge action, thereby facilitating timely troubleshooting and maintenance, but also can promptly purge out the leaked methanol to prevent the leaked methanol from remaining for a long time and corroding the structure.

[0058] In one embodiment, if Figure 10 As shown, the outer wall of the alcohol sprayer 2 near the inlet end is provided with an annular step 21. Figure 11 and Figure 12 As shown, a predetermined distance is reserved between the end face of the compression block 3 inserted into the mounting channel 13 and the surface of the annular step 21, thereby forming an annular cavity 44, which is part of the enclosed cavity. The annular cavity 44 provides a buffer space for leaking methanol, allowing for temporary buffering of leaked methanol during intermittent purge activation. Furthermore, the purge inlet and outlet (i.e., the first and second interfaces) are located on either side of the annular cavity 44, forming a purge guide path that facilitates the removal of as much leaked methanol as possible.

[0059] In one embodiment, the height of the first interface and the second interface on the installation channel 13 is preferably consistent with the height of the annular cavity 44 (not shown in the figure), thereby better ensuring the purging effect of the purging gas.

[0060] In one embodiment, an annular gasket may also be installed in the annular cavity 44 , and the annular gasket is compressed by the pressing block 3 and the annular step 21 of the alcohol sprayer 2 to enhance the sealing effect.

[0061] In one embodiment, if Figure 9 and Figure 11As shown, a wiring harness channel 32 can be provided on the pressing block 3 to facilitate the extraction of the power harness and control harness of the alcohol sprayer 2. A gasket can be provided between the pressing block 3 and the wiring harness channel 32 for sealing to prevent methanol from flowing out of the wiring harness channel 32.

[0062] In one embodiment, if Figure 2 and Figure 3 As shown, the end of the mixing pipe section 12 away from the intake pipe section 11 is provided with a docking flange 121 for sealing connection with the engine cylinder head, and a corresponding flange structure is also provided on the engine cylinder head side, through which a convenient connection with the cylinder head structure is achieved.

[0063] The present application also provides an engine intake assembly structure comprising a plurality of the aforementioned engine intake unit structures 100 and a connector (not shown). The intake pipe sections 11 of the intake manifolds 1 of the plurality of engine intake unit structures 100 are sequentially connected end-to-end via the connector. The connector may be a flanged expansion joint or a clamp.

[0064] The present application also provides an engine comprising a cylinder head and the aforementioned engine intake assembly structure, wherein the cylinder head has multiple intake ports reserved thereon, and the mixing pipe section 12 of the intake manifold 1 of the engine intake assembly structure is connected to the intake ports on the cylinder head.

[0065] The foregoing description is merely a partial embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An engine air intake unit structure, characterized in that: include: An intake manifold (1) comprises an intake pipe section (11) with openings at both ends and a mixing pipe section (12) connected to the main body of the intake pipe section (11), wherein the intake pipe section (11) extends along a first direction, and the mixing pipe section (12) extends along a second direction, the first direction being perpendicular to the second direction; an end of the mixing pipe section (12) away from the intake pipe section (11) is used for docking with an engine cylinder head; and the mixing pipe section (12) is provided with at least two injection positions; An alcohol sprayer (2) is installed at the injection position, and multiple alcohol sprayers (2) spray methanol into the mixing pipe section (12), and the injection directions of the multiple alcohol sprayers (2) intersect with each other in a plane perpendicular to the second direction.

2. The engine air intake unit structure according to claim 1, characterized in that: The mixing pipe section (12) is provided with two injection positions, each of which is equipped with an alcohol sprayer (2), and the angle between the injection directions of the two alcohol sprayers (2) is in the range of 60° to 120°.

3. The engine air intake unit structure according to claim 2, characterized in that: The included angle between the spraying directions of the two alcohol sprayers (2) is 90°.

4. The engine air intake unit structure according to claim 1 or 2, characterized in that: The injection position of the mixing pipe section (12) is provided with an installation channel (13) that penetrates into the interior of the mixing pipe section (12), and the alcohol sprayer (2) is installed in the installation channel (13); the alcohol sprayer (2) includes an injection end close to one side of the mixing pipe section (12) and an inlet end away from the mixing pipe section (12); The engine air intake unit structure further includes: A pressing block (3) is fixedly mounted on one end of the mounting channel (13) away from the mixing pipe section (12) and is sealedly connected to the periphery of the inlet end of the alcohol sprayer (2). The pressing block (3) is provided with an air inlet channel that is docked with and communicated with the inlet end of the alcohol sprayer (2).

5. The engine air intake unit structure according to claim 4, characterized in that: The bottom of the pressing block (3) is annular, a first sealing structure (41) is provided between the inner wall of the pressing block (3) and the outer wall of the inlet end of the alcohol sprayer (2), a second sealing structure (42) is provided between the outer wall of the pressing block (3) and the inner wall of the installation channel (13), and a third sealing structure (43) is provided between the outer wall of the alcohol sprayer (2) body and the inner wall of the installation channel (13); The first sealing structure (41), the second sealing structure (42) and the third sealing structure (43) form a closed cavity; The installation channel (13) is provided with a first interface and a second interface communicating with the closed cavity.

6. The engine air intake unit structure according to claim 5, characterized in that: An annular step (21) is provided on the outer wall of the alcohol sprayer (2) near the inlet end, and a predetermined distance is reserved between the end face of the pressing block (3) inserted into one side of the installation channel (13) and the surface of the annular step (21) to form an annular cavity (44), and the annular cavity (44) is part of the closed cavity.

7. The engine air intake unit structure according to claim 6, characterized in that: The arrangement heights of the first interface and the second interface on the installation channel (13) are consistent with the height of the annular cavity (44).

8. The engine air intake unit structure according to claim 1, characterized in that: One end of the mixing pipe section (12) away from the air intake pipe section (11) is provided with a docking flange (121) for sealing connection with the engine cylinder head.

9. An engine intake assembly structure, characterized in that: comprising a plurality of engine air intake unit structures according to any one of claims 1 to 8, further comprising a connecting member; The air intake pipe sections (11) of the air intake manifolds (1) of the plurality of engine air intake unit structures are connected end to end in sequence through the connecting piece.

10. An engine, characterized in that: include: a cylinder head, wherein a plurality of air inlets are reserved on the cylinder head; The engine air intake assembly structure according to claim 9, wherein the mixing pipe section (12) of the air intake manifold (1) of the engine air intake assembly structure is connected to the air intake port on the cylinder head.

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