Engine air intake unit structure, air intake combination structure, and engine

Abstract

The application provides an engine air intake unit structure, an air intake assembly structure and an engine. The engine air intake unit structure comprises an air intake header and a methanol injector. The air intake header comprises an air intake pipe section with open ends and a mixing pipe section in communication with the air intake pipe section. The air intake pipe section extends along a first direction, and the mixing pipe section extends along a second direction. The first direction is perpendicular to the second direction. An end of the mixing pipe section away from the air intake pipe section is used to be in butt joint with an engine cylinder head. At least two injection positions are arranged on the mixing pipe section. The methanol injectors are arranged at the injection positions. Multiple methanol injectors inject methanol into the mixing pipe section. The injection directions of the multiple methanol injectors intersect with each other in a plane perpendicular to the second direction. The technical scheme of the application integrates the methanol injectors and the air intake header into an independent unit module, avoids direct corrosion of the methanol on the cylinder head, reduces the difficulty of improvement of the cylinder head, prolongs the mixing path of the methanol and air, and improves the uniformity and optimizes the combustion by cooperating with the cross injection of the methanol injectors.

Description

Technical Field

[0001] This application relates to the field of engine intake technology, and more specifically, to an engine intake unit structure, an intake assembly structure, and an engine. Background Technology

[0002] A methanol-fueled engine is an internal combustion engine that uses methanol as its primary fuel. Its main advantages include minimal modifications to the original engine and lower atmospheric pollution. With the decreasing cost of methanol production, methanol intake manifold injection technology for marine applications has become a crucial pathway for the low-carbon transformation of internal combustion engines.

[0003] Currently, there are two forms of methanol intake manifold injection technology. The first type designs the engine cylinder head and intake manifold as a single cast structure, with the methanol injector located at the bottom of the intake passage within this integrated structure. The disadvantages of this type are: it is only suitable for completely new engine models designed from scratch, and not for modified engines (modified engines refer to minor modifications to the original marine diesel engine structure, ultimately converting it into a methanol / diesel dual-fuel engine), and the design time and economic costs are relatively high.

[0004] The second approach involves placing the methanol injector only above the cylinder head intake manifold. The disadvantages of this design are: the compact structure of the cylinder head severely limits the size and placement of the methanol injector; and because the injector is located on the cylinder head, the uniformity of methanol-air mixing is relatively poor. Furthermore, since methanol-air mixing is a complex process, the methanol injected by the injector has a high probability of directly spraying onto the cylinder head structure, leading to continuous corrosion of the cylinder head. Therefore, if corrosion becomes 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 methanol injector and the intake manifold into an independent unit module, avoiding direct corrosion of the cylinder head by methanol, reducing the difficulty of cylinder head improvement, extending the methanol-air mixing path, and cooperating with the methanol injector for cross-injection to improve uniformity and optimize combustion.

[0006] In one aspect, an engine intake unit structure is provided, including an intake manifold and an alcohol injector.

[0007] The intake manifold includes an intake pipe section open at both ends and a mixing pipe section connected to the intake pipe section body. The intake pipe section extends along a first direction, and the mixing pipe section extends along a second direction, which is perpendicular to the first direction. The end of the mixing pipe section away from the intake pipe section is used to connect with the engine cylinder head. At least two injection positions are provided on the mixing pipe section. Methanol injectors are installed at the injection positions, and multiple methanol injectors inject methanol into the mixing pipe section. The injection directions of the multiple methanol injectors intersect each other in a plane perpendicular to the second direction.

[0008] In one feasible scheme, two injection positions are provided on the mixing pipe section, and each injection position is equipped with an alcohol sprayer. The included angle between the injection directions of the two alcohol sprayers is in the range of 60° to 120°.

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

[0010] In one feasible embodiment, an installation channel extending into the interior of the mixing pipe section is provided at the injection position of the mixing pipe section, and the alcohol injector is installed in the installation channel; the alcohol injector includes an injection end near the mixing pipe section and an inlet end away from the mixing pipe section;

[0011] The engine intake unit structure also includes:

[0012] The pressure block is fixedly installed at the end of the installation channel away from the mixing pipe section and is sealed to the outer periphery of the inlet end of the alcohol injector. The pressure block is provided with a methanol inlet channel that is connected to and communicates with the inlet end of the alcohol injector.

[0013] In one feasible solution, the bottom of the pressure block is annular, a first sealing structure is provided between the inner wall of the pressure 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 pressure 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 equipped with a first interface and a second interface that communicate with the enclosed cavity.

[0016] In one feasible embodiment, 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 a closed cavity.

[0017] In one feasible embodiment, the first and second interfaces on the mounting channel are positioned at the same height as the annular cavity.

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

[0019] Secondly, an engine intake assembly structure is also provided, including multiple aforementioned engine intake unit structures and connecting members. The intake pipe sections of the intake manifolds of the multiple engine intake unit structures are connected end-to-end sequentially via the connecting members.

[0020] Thirdly, an engine is also provided, including a cylinder head and the aforementioned engine intake assembly structure. Multiple air intake ports are pre-installed on the cylinder head. The mixing section of the intake manifold of the engine intake assembly structure connects to the air intake ports on the cylinder head.

[0021] Compared with the prior art, the beneficial effects of this application include at least the following: In the engine intake unit structure of this application, the mixing pipe section of the intake manifold is detachably fixed to the cylinder head, while the methanol injector is directly installed on the mixing pipe section, thereby moving the methanol injection and air mixing functions out of the cylinder head as a whole, forming an independent unit. Compared with the traditional solution of integral molding of the cylinder head and intake pipe section, this structure does not require extensive redesign, and the casting and machining difficulties are significantly reduced.

[0022] Since the methanol injector is no longer installed in the cylinder head but integrated into the intake manifold, even if a small amount of methanol leaks, the risk of corrosion is limited to the intake manifold itself, thus preventing damage to the cylinder head. Furthermore, as an independent component, the intake manifold is easy and inexpensive to replace and maintain even if it is corroded. In addition, with the injector located on the mixing section of the intake manifold, compared to the design where it is mounted on the cylinder head, methanol and air have a longer mixing path and a larger mixing volume, resulting in significantly improved mixing uniformity and consequently, better combustion quality.

[0023] Furthermore, the multiple methanol injectors arranged on the mixing pipe section have their injection directions intersecting each other in a plane perpendicular to the second direction L2, forming a three-dimensional mixing atomization field, which further enhances the mixing quality of methanol and air, and provides a guarantee for efficient and stable combustion. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a perspective view of an engine intake unit structure shown in an embodiment of this application.

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

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

[0028] Figure 4 for Figure 3 Sectional view along the middle 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 A cross-sectional view along the middle BB.

[0031] Figure 7 for Figure 5 A sectional view along the center CC.

[0032] Figure 8 for Figure 1 A structural diagram of the pressure block in the intake unit of the engine.

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

[0034] Figure 10 for Figure 1 A structural diagram of the alcohol injector in the intake unit of a medium-sized engine.

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

[0036] Figure 12 for Figure 11 Enlarged view of the local structure of the annular cavity between the alcohol sprayer and the press block.

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

[0038] Figure 14 for Figure 13 A sectional view along the middle DD.

[0039] In the diagram: 100, Engine intake unit structure; 1, Intake manifold; 11, Intake pipe section; 12, Mixing pipe section; 121, Connecting flange; 13, Installation channel; 2, Methanol injector; 21, Annular step; 3, Pressure 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 intake pipe; 53, Purge exhaust pipe; L1, First direction; L2, Second direction. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

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

[0043] The intake manifold 1 includes an intake pipe section 11 with openings at both ends and a mixing pipe section 12 connected to the 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 away from the intake pipe section 11 is used to connect with the engine cylinder head. At least two injection positions are provided on the mixing pipe section 12. Methanol injectors 2 are installed at the injection positions, and multiple methanol injectors 2 inject methanol into the mixing pipe section 12. The injection directions of the multiple methanol injectors 2 intersect each other 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 methanol injector 2. The injection position is provided with at least an opening that communicates with the inside of the mixing pipe section 12 so that the methanol injector 2 can inject methanol into the mixing pipe section 12 and mix it with the air delivered from the air intake pipe section 11.

[0045] It should also be noted that the extension of the mixing pipe section 12 along the second direction L2 can be understood as the axis of the mixing pipe section 12 being completely coincident with the second direction L2; or it can be understood as the axis of the mixing pipe section 12 having a certain angle with the second direction L2, but its overall extension direction still maintaining the extension towards the second direction L2.

[0046] In the engine intake unit structure of this embodiment, the mixing pipe section 12 of the intake manifold 1 is detachably fixed to the cylinder head, while the methanol injector 2 is directly installed on the mixing pipe section 12. This removes the methanol injection and air mixing functions from the cylinder head, forming an independent unit. Compared to the traditional solution where the cylinder head and intake pipe section are integrally formed, this structure does not require extensive redesign, and the casting and machining difficulties are significantly reduced.

[0047] Since the methanol injector 2 is no longer installed in the cylinder head but integrated into the intake manifold 1, even if a small amount of methanol leaks, the risk of corrosion is limited to the intake manifold 1 itself, thus preventing damage to the cylinder head. Furthermore, as an independent component, the intake manifold 1 is easy and inexpensive to replace and maintain even if it is corroded. In addition, the methanol injector 2 is located on the mixing section 12 of the intake manifold 1. Compared to the design where it is installed on the cylinder head, methanol and air have a longer mixing path and a larger mixing volume, resulting in significantly improved mixing uniformity and consequently, enhanced combustion quality.

[0048] Furthermore, the multiple methanol injectors 2 arranged on the mixing pipe section 12 have their injection directions intersecting each other in a plane perpendicular to the second direction L2, forming a three-dimensional mixing atomization field, which further enhances the mixing quality of methanol and air, improves the mixing effect, and provides a guarantee for efficient and stable combustion.

[0049] Furthermore, this design is compatible with both retrofitted and newly built engines. Retrofitted engines refer to minor modifications to the existing marine diesel engine structure, ultimately converting it into a methanol / diesel dual-fuel engine. Newly built engines refer to entirely new designed and manufactured methanol-fueled engines, rather than partial modifications to existing diesel engines.

[0050] In one embodiment, such as Figure 2 As shown, the mixing pipe section 12 preferably has two injection positions, each injection position is equipped with an alcohol sprayer 2, and the included angle β between the injection directions of the two alcohol sprayers 2 is in the range of 60° to 120°. For example, the included angle β can be 60°, 70°, 80°, 90°, 100°, 110°, 120°, etc.

[0051] In one embodiment, the included angle β of the spraying directions of the two methanol injectors 2 is preferably set to 90°, and the intersection of the center lines of the spraying directions of the two methanol injectors 2 coincides with or approximately coincides with the central axis of the mixing pipe section 12, thereby making the methanol sprayed by the two methanol injectors 2 overlap a larger area and have a larger contact area with air, which helps to improve the mixing uniformity.

[0052] In one embodiment, such as Figure 4 and Figure 6 As shown, an installation channel 13 extending into the interior of the mixing pipe section 12 is provided at the injection position, and the alcohol injector 2 is installed in the installation channel 13. The alcohol injector 2 includes an injection end near the mixing pipe section 12 and an inlet end away from the mixing pipe section 12. The engine intake unit structure also includes a pressure block 3, which is fixedly installed at the end of the installation channel 13 away from the mixing pipe section 12 and is sealed to the outer periphery of the inlet end of the alcohol injector 2. The pressure block 3 is provided with a methanol inlet channel 31 that connects to and communicates with the inlet end of the alcohol injector 2. It should be noted that the outer periphery of the pressure block 3 can be securely connected to the outer periphery of the installation channel 13 using fasteners such as bolts and nuts. Figure 2 and Figure 3 As shown, the methanol inlet channel 31 is connected to the methanol fuel inlet pipe 51 for transporting methanol.

[0053] In one embodiment, such as Figure 8 and Figure 9 As shown, the bottom of the pressure block 3 is ring-shaped. Figure 11 and Figure 12 As shown, a first sealing structure 41 is provided between the inner wall of the pressure 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 pressure 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 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. 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 arrangement. For example... Figure 3 , Figure 13 and Figure 14 As shown, the first interface is connected to the purge inlet pipe 52, and the second interface is connected to the purge outlet pipe 53.

[0054] In one embodiment, such as 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 sprayer 2, and a first O-ring can be installed in the first annular groove. After the pressure block 3 is installed, its inner wall is tightly fitted with the first O-ring to form a first sealing structure 41.

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

[0056] In one embodiment, such as Figure 10 As shown, at least one third annular groove can be provided on the outer periphery of the middle and lower part 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 and the third O-ring are tightly fitted to form a third sealing structure 43.

[0057] In one embodiment, a purging device (not shown in the figure) and a detection device (not shown in the figure) may also be provided. The purging device is connected to the purging inlet pipe 52, and the purging outlet pipe 53 is connected to the detection device. If the first sealing structure 41 fails to a certain extent, causing methanol leakage at the inlet of the methanol injector 2, the leaked methanol will enter the closed cavity formed by the three sealing structures. The purging device (the purging gas can be nitrogen) is activated intermittently. See [reference needed]. Figure 14 As indicated by the arrow, the purging gas enters the sealed cavity through the purging inlet pipe 52, and then exits through the purging outlet pipe 53 and is delivered to the detection device to detect the methanol concentration and determine whether a leak has occurred. Therefore, this embodiment, by setting up a sealed cavity and first and second interfaces, can conveniently detect whether a leak has occurred at the inlet of the methanol injector 2 through purging action, facilitating timely troubleshooting and maintenance. It can also promptly purge leaked methanol to prevent prolonged residual methanol from corroding the structure.

[0058] In one embodiment, such as Figure 10 As shown, the outer wall of the alcohol sprayer 2 near the inlet end is provided with an annular step 21. (As shown...) Figure 11 and Figure 12 As shown, a predetermined distance is reserved between the end face of the pressure block 3 inserted into the installation channel 13 and the surface of the annular step 21 to form an annular cavity 44, which is part of a closed cavity. The annular cavity 44 is configured to provide a certain buffer space for leaked methanol, so as to temporarily buffer the leaked methanol during intermittent purging. In addition, the purging inlet and outlet (i.e., the first interface and the second interface) are respectively located on both sides of the annular cavity 44, and the annular cavity 44 can form a purging guide path, which is more conducive to purging out as much of the leaked methanol as possible.

[0059] In one embodiment, the height of the first and second interfaces on the mounting channel 13 is preferably the same as the height of the annular cavity 44 (not shown in the figure), which is more conducive to ensuring the purging effect of the purging gas.

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

[0061] In one embodiment, such as Figure 9 and Figure 11As shown, a wiring harness channel 32 can be provided on the pressure block 3 to facilitate the lead-out of the power and control wiring harnesses of the methanol injector 2. A gasket can be provided between the pressure 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, such as 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. The engine cylinder head side is also provided with a corresponding flange structure, and the docking flange 121 is used to achieve convenient connection with the cylinder head structure.

[0063] This application embodiment also provides an engine intake assembly structure, including multiple aforementioned engine intake unit structures 100, and a connector (not shown in the figure). The intake pipe sections 11 of the intake manifolds 1 of the multiple engine intake unit structures 100 are connected end to end in sequence through the connector. The connector can be an expansion joint with a flange or a clamp, etc.

[0064] This application also provides an engine, including a cylinder head and the aforementioned engine intake assembly structure. The cylinder head has multiple air intake ports, and the mixing section 12 of the intake manifold 1 of the engine intake assembly structure is connected to the air intake ports on the cylinder head.

[0065] The above description is only a partial embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An engine intake unit structure, characterized in that, include: An intake manifold (1) includes an intake pipe section (11) open at both ends and a mixing pipe section (12) connected to the body of the intake pipe section (11). 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. One end of the mixing pipe section (12) away from the intake pipe section (11) is used to connect with the engine cylinder head. At least two injection positions are provided on the mixing pipe section (12). Methanol injector (2), installed at the injection position, a plurality of methanol injectors (2) inject methanol into the mixing pipe section (12), the injection directions of the plurality of methanol injectors (2) intersect each other in a plane perpendicular to the second direction.

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

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

4. The engine intake unit structure according to claim 1 or 2, characterized in that, The mixing pipe section (12) has an installation channel (13) extending into the interior of the mixing pipe section (12) at the injection position, and the alcohol sprayer (2) is installed in the installation channel (13); the alcohol sprayer (2) includes an injection end near the mixing pipe section (12) and an inlet end away from the mixing pipe section (12); The engine intake unit structure also includes: The pressure block (3) is fixedly installed at one end of the installation channel (13) away from the mixing pipe section (12) and is sealed to the outer periphery of the inlet end of the alcohol sprayer (2). The pressure block (3) is provided with an air intake channel that is connected to and communicates with the inlet end of the alcohol sprayer (2).

5. The engine intake unit structure according to claim 4, characterized in that, The bottom of the pressure block (3) is annular. A first sealing structure (41) is provided between the inner wall of the pressure 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 pressure block (3) and the inner wall of the installation channel (13). A third sealing structure (43) is provided between the outer wall of the alcohol sprayer (2) 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 that communicate with the enclosed cavity.

6. The engine intake unit structure according to claim 5, characterized in that, The alcohol sprayer (2) has an annular step (21) on its outer wall near the inlet end. The end face of the pressure block (3) inserted into the installation channel (13) is spaced at a predetermined distance from the surface of the annular step (21) to form an annular cavity (44), which is part of the closed cavity.

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

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

9. An engine intake assembly structure, characterized in that, It includes multiple engine intake unit structures as described in any one of claims 1-8, and also includes connecting members; The intake pipe sections (11) of the intake manifolds (1) of the multiple engine intake unit structures are connected end to end in sequence through the connector.

10. An engine, characterized in that, include: Cylinder head, wherein multiple air intake ports are provided on the cylinder head; As described in claim 9, the mixing section (12) of the intake manifold (1) of the engine intake assembly is connected to the intake port on the cylinder head.

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