A dual-fuel engine injector that solves nozzle clogging

Abstract

This utility model discloses a dual-fuel engine injector that can solve the problem of nozzle blockage, belonging to the field of injector technology. It includes an injector body and a needle valve body. A first needle valve passes through the needle valve body, and a second needle valve passes through the first needle valve. Multiple diesel injection holes are arranged at the bottom of the first needle valve. The inner wall of the diesel injection holes contains multiple spiral grooves, including several main spiral grooves and several secondary spiral grooves. The secondary spiral grooves are spirally arranged at the inlet and outlet ends of the diesel injection holes, and the main spiral grooves are spirally arranged continuously between the inlet and outlet secondary spiral grooves. Before the diesel fuel enters the main spiral groove and undergoes large-scale rotation, it is slowly accelerated at the inlet end of the secondary spiral groove. After flowing out of the main spiral groove, the rotational scale is reduced at the outlet end of the secondary spiral groove, ensuring the flow cross-sectional area. This allows the diesel fuel in the injection holes to generate rotational motion and increase speed, achieving a flushing effect on the inner wall, while also stabilizing the injection flow at the outlet end, ensuring stable combustion in the engine cavity.

Description

Technical Field

[0001] This utility model belongs to the field of injector technology, specifically relating to a dual-fuel engine injector that can solve the problem of nozzle clogging. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Dual-fuel direct injection technology mainly uses a small amount of diesel fuel injected into the cylinder to ignite the main fuel (natural gas, methanol, hydrogen, etc.), resulting in higher engine thermal efficiency and avoiding the knocking problem present in traditional spark-ignition engines.

[0004] For example, an existing dual-fuel engine injector includes an injector body and a needle valve body connected to the injector body. The needle valve body is provided with a double row of nozzles, with the upper layer being natural gas nozzles and the lower layer being diesel nozzles. The working mode is that diesel is injected first, and after the diesel is compressed and ignited in the cylinder, natural gas is injected. The natural gas is ignited by the flame of the diesel, and then it burns to do power.

[0005] However, in existing technologies, diesel injection orifices are mostly designed as straight holes, causing some diesel fuel to flow close to the orifice wall, such as... Figure 1 As shown, diesel fuel tends to gradually adhere to and remain on the inner wall of the diesel injection nozzle, and is prone to coking at high temperatures. Because the flow rate of diesel fuel during injection is low, the coked diesel fuel is difficult to wash away, thus causing nozzle blockage. Utility Model Content

[0006] To address the aforementioned problems, this invention provides a dual-fuel engine injector that can solve nozzle clogging. It involves setting several secondary spiral grooves at the inlet and outlet ends of the diesel injection nozzle's inner wall, and between these secondary spiral grooves at the inlet and outlet ends, setting several main spiral grooves that are deeper, wider, and longer than the secondary spiral grooves. Before the diesel fuel enters the main spiral grooves and undergoes large-scale rotation, it is slowly accelerated by the action of the secondary spiral grooves at the inlet end. After flowing out of the main spiral grooves, the rotational speed is reduced at the secondary spiral grooves at the outlet end, ensuring a stable flow cross-sectional area. This allows the diesel fuel in the nozzle to generate rotational motion and increase speed, achieving a flushing effect on the inner wall of the nozzle while also stabilizing the flow rate at the outlet end, ensuring stable combustion within the engine cavity.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A dual-fuel engine injector that can solve nozzle clogging includes an injector body and a needle valve body connected to the injector body. A first needle valve passes through the needle valve body, and a second needle valve passes through the first needle valve. Multiple natural gas nozzles are provided at the bottom of the needle valve body, and multiple diesel nozzles are provided at the bottom of the first needle valve. The inner wall of the diesel nozzles contains multiple spiral grooves, including several main spiral grooves and several auxiliary spiral grooves.

[0009] The auxiliary spiral groove is spirally arranged at the inlet and outlet ends of the diesel injection hole, and the main spiral groove is spirally arranged between the auxiliary spiral groove at the inlet end and the auxiliary spiral groove at the outlet end.

[0010] Preferably, the width and depth of the secondary threaded groove are both smaller than the width and depth of the primary threaded groove.

[0011] Preferably, the needle valve body and the first needle valve enclose a natural gas supply channel, and the first needle valve and the second needle valve enclose a diesel fuel supply channel.

[0012] Preferably, the plurality of natural gas injection holes are evenly distributed along the circumference of the needle valve body, and the plurality of diesel injection holes are evenly distributed along the circumference of the first needle valve.

[0013] Preferably, the cross-sections of both the secondary threaded groove and the primary threaded groove are rectangular.

[0014] Preferably, the horizontal length of the main threaded groove is D2, and the horizontal length of the secondary threaded groove is D1; ​​the relationship between the horizontal lengths of the main threaded groove and the secondary threaded groove needs to satisfy D2 / 5≤D1≤D2 / 4.

[0015] Preferably, the width of the main threaded groove is L2 and the depth is H2, wherein the relationship between L2 and D2 needs to satisfy L2 < D2 / 10 and H2 < D2 / 20.

[0016] Preferably, the width of the secondary screw groove is L1 and the depth is H1; the relationship between L1 and L2 must satisfy: L2 / 3 < L1 < L2; the relationship between H1 and H2 must satisfy: H2 / 3 < H1 < H2.

[0017] Preferably, the number of secondary threaded grooves and primary threaded grooves is in the range of 2-5 times that of secondary threaded grooves.

[0018] Preferably, the optimal number of main screw grooves is 5-10.

[0019] Compared with the prior art, the advantages and positive effects of this utility model are:

[0020] This invention features several secondary spiral grooves at the inlet and outlet ends of the diesel injection orifice. Between these secondary spiral grooves, several main spiral grooves are formed, each deeper, wider, and longer than the secondary spiral grooves. Before the diesel fuel enters the main spiral grooves and undergoes large-scale rotation, it is slowly accelerated by the secondary spiral grooves at the inlet end. After flowing out of the main spiral grooves, the rotational speed is reduced at the secondary spiral grooves at the outlet end, ensuring a stable flow cross-sectional area. This allows the diesel fuel in the injection orifice to rotate and increase its speed, achieving a flushing effect on the inner wall of the orifice while also stabilizing the flow rate at the outlet end, thus ensuring stable combustion within the engine cavity. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0022] Figure 1 This is a schematic diagram of diesel flow inside a diesel nozzle in existing technology;

[0023] Figure 2 This is a schematic diagram of the needle valve body of the dual-fuel engine injector according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the main threaded groove and the auxiliary threaded groove in an embodiment of this utility model;

[0025] Figure 4 This is a schematic diagram showing the relationship between the horizontal lengths of the main threaded groove and the auxiliary threaded groove in an embodiment of this utility model;

[0026] Figure 5 This is a schematic diagram showing the relationship between the depth and width of the main threaded groove and the auxiliary threaded groove in an embodiment of this utility model;

[0027] Figure 6 This is a schematic diagram of diesel flow inside the diesel nozzle according to an embodiment of the present invention;

[0028] In the picture:

[0029] 1. Needle valve body; 11. First needle valve; 12. Second needle valve; 2. Diesel injection port; 3. Natural gas injection port; 4. Main screw groove; 5. Secondary screw groove. Detailed Implementation

[0030] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] The present invention will now be described in detail with reference to the accompanying drawings. This embodiment discloses a dual-fuel engine injector that can solve nozzle clogging, which also includes an injector body and a needle valve body 1 connected to the injector body; as shown below... Figure 2 As shown, specifically, a first needle valve 11 is inserted inside the needle valve body 1, and a second needle valve 12 is inserted inside the first needle valve 11. The needle valve body 1 and the first needle valve 11 enclose each other to form a natural gas supply channel, and the first needle valve 11 and the second needle valve 12 enclose each other to form a diesel fuel supply channel. Multiple natural gas injection holes 3 are provided at the bottom of the needle valve body 1, and multiple diesel injection holes 2 are provided at the bottom of the first needle valve 11.

[0032] Furthermore, multiple natural gas injection holes 3 are evenly distributed along the circumference of the needle valve body 1, and multiple diesel injection holes 2 are evenly distributed along the circumference of the first needle valve 11.

[0033] In this embodiment, the injector also operates by first injecting diesel fuel, which is then compressed and ignited in the cylinder before injecting natural gas. The diesel flame ignites the natural gas, which then burns and performs work.

[0034] It should be explained that in the prior art, when diesel injection is in progress, the second needle valve 12 moves upward, and the diesel injection hole 2 connects with the diesel fuel supply channel, so that diesel is injected from the diesel injection hole; when natural gas injection is in progress, the first needle valve 11 moves upward, and the natural gas injection hole 3 connects with the natural gas supply channel, so that natural gas is injected from the natural gas injection hole 3.

[0035] It should be noted that in this embodiment, the inner wall of the diesel injection hole 2 is provided with multiple spiral grooves, rather than a traditional straight hole design.

[0036] When diesel fuel is injected through diesel nozzle 2, the diesel fuel will rotate rapidly under the action of multiple spiral grooves, which can effectively flush away the coking on the inner wall of diesel nozzle 2 and prevent the diesel nozzle from being blocked. In addition, under the action of multiple spiral grooves, the pressure at the outlet of diesel nozzle 2 can be increased, enhancing the atomization effect of diesel fuel and increasing the kinetic energy of diesel fuel when it leaves diesel nozzle 2 in a rotating state.

[0037] Specifically, such as Figure 3 As shown, the multiple spiral grooves on the inner wall of the diesel injection hole 2 include several main spiral grooves 4 and several secondary spiral grooves 5. The width and depth of the secondary spiral grooves 5 are smaller than those of the main spiral grooves 4. The secondary spiral grooves 5 are spirally arranged near the inlet and outlet ends of the diesel injection hole 2, while the main spiral grooves 4 are spirally arranged along the entire length from the inlet end to the outlet end of the diesel injection hole 2. That is, the main spiral grooves 4 are located between the secondary spiral grooves 5 at the inlet end and the secondary spiral grooves 5 at the outlet end of the diesel injection hole 2.

[0038] It should be explained that the width and depth of the secondary screw groove 5 are designed to be smaller than those of the main screw groove 4 so that the diesel fuel passing through the main screw groove 4 will rotate on a large scale, while the diesel fuel passing through the secondary screw groove 5 will rotate on a small scale.

[0039] Furthermore, when diesel fuel passes through the main screw groove 4, it generates large-scale rotation, thereby obtaining a large centrifugal force to effectively flush the inner wall of the diesel fuel injection hole 2. In addition, the setting of a certain length of main screw groove 4 can also increase the flow rate of diesel fuel.

[0040] It should be explained that the continuous main spiral groove 4 inside the diesel injection hole 2 can cause the diesel to gradually generate large-scale rotation inside the diesel injection hole 2 after entering from the inlet end, increasing the scouring kinetic energy of the diesel on the inner wall of the diesel injection hole 2. As the length of the main spiral groove 4 increases, the flow rate of the diesel will also gradually increase.

[0041] However, this large-scale rotation will cause the actual flow cross-sectional area of ​​diesel fuel inside the diesel injection orifice 2 to gradually decrease from the inlet end to the outlet end of the diesel injection orifice 2. This will lead to a gradual decrease in the amount of diesel fuel flowing inside the diesel injection orifice 2. Ultimately, this will result in unstable diesel fuel injection flow at the outlet of the diesel injection orifice 2, which will further lead to poor combustion in the engine cavity and cause fluctuations in fuel consumption.

[0042] In order to enable the diesel fuel in the diesel injection hole 2 to generate rotational motion and increase speed, thereby achieving a flushing effect on the inner wall of the diesel injection hole 2, and at the same time to ensure stable flow rate at the outlet end of the diesel injection hole 2, so as to ensure stable combustion in the engine cavity.

[0043] In this embodiment, shallower and narrower secondary spiral grooves 5 are provided on the inner walls of both the inlet and outlet ends of the diesel injection orifice 2 to reduce the rotational scale of the diesel fuel on the inner wall of the diesel injection orifice 2. Because the secondary spiral grooves 5 are shallow and narrow, the diesel fuel does not directly generate large-scale rotation when it enters the diesel injection orifice 2 and passes through the secondary spiral groove 5 at the inlet end. Instead, it first generates a certain small-scale rotation, resulting in a slow acceleration at the inlet end. Then, when the diesel fuel flows through the main spiral groove 4, it begins to generate large-scale rotation and gradually increases its flow velocity, scouring the inner wall of the diesel injection orifice 2. Finally, when the diesel fuel flows through the secondary spiral groove 5 at the outlet end, the rotational scale decreases again, and the diesel fuel flow velocity and rotation are reduced, ensuring the flow cross-sectional area.

[0044] In this embodiment, multiple spiral grooves can be processed using laser engraving technology. The number of main spiral grooves 4 is set to 5-10, and the ratio of the number of main spiral grooves 4 to auxiliary spiral grooves 5 is 2-5 times that of auxiliary spiral grooves 5. This design is because if a large number of spiral grooves are provided on the inner wall of the diesel injection hole 2, it will increase the actual diameter of the diesel injection hole 2, which will lead to a poorer atomization effect of diesel injection.

[0045] It is easy to understand that, in this embodiment, the relationship between the main threaded groove 4 and the secondary threaded groove 5 includes: the positional relationship between the main threaded groove 4 and the secondary threaded groove 5, the length relationship between the main threaded groove 4 and the secondary threaded groove 5, the width relationship between the main threaded groove 4 and the secondary threaded groove 5, and the depth relationship between the main threaded groove 4 and the secondary threaded groove 5.

[0046] like Figure 4 As shown, the length relationship between the main screw groove 4 and the auxiliary screw groove 5 needs to be ensured. After the diesel fuel enters the diesel injection hole 2, with the cooperation of the main screw groove and the auxiliary screw groove, it can both flush the inner wall of the diesel injection hole 2 through the large-scale rotation of the main screw groove and achieve a stable flow rate at the outlet end.

[0047] Therefore, the length of the auxiliary screw groove 5 cannot be too long, because this would shorten the length of the main screw groove 4, which would prevent the diesel fuel from effectively accelerating in the main screw groove 4 and thus failing to effectively flush the inner wall of the diesel injection hole 2. On the other hand, the length of the main screw groove cannot be too long either, because this would shorten the length of the auxiliary screw grooves 5 on both sides, thus failing to create a slow acceleration at the inlet end and failing to effectively reduce the rotational scale at the outlet end to ensure the flow cross-sectional area.

[0048] In order to ensure that the diesel fuel can scour the inner wall of the diesel injection hole 2 and maintain a stable flow rate when it is sprayed out at the outlet, in this example, the horizontal length of the main screw groove 4 is D2, the horizontal length of the auxiliary screw groove 5 is D1, and the horizontal length of the diesel injection hole 2 is D, where D = 2D1 + D2; the horizontal length relationship between the main screw groove 4 and the auxiliary screw groove 5 needs to satisfy D2 / 5 ≤ D1 ≤ D2 / 4.

[0049] More specifically, in this embodiment, the cross-sections of both the main threaded groove 4 and the secondary threaded groove 5 are rectangular.

[0050] Furthermore, it can be understood that the width and depth of the main screw groove 4 determine the amount of diesel fuel flowing within it, and also the scale of rotation that the diesel fuel generates as it passes through. This rotation, combined with the increased speed after flowing a certain length, results in the increased speed. Therefore, the width and depth of the main screw groove 4 are related to its horizontal length. In this embodiment, the width of the main screw groove 4 is L2, and the depth is H2. The width L2 needs to be less than D2 / 10, and the depth H2 needs to be less than D2 / 20.

[0051] Furthermore, the width relationship between the main screw groove 4 and the auxiliary screw groove 5, as well as the depth relationship between the main screw groove 4 and the auxiliary screw groove 5, need to satisfy the following: the main screw groove 4 can cause the diesel fuel passing through to rotate on a large scale and increase the centrifugal force, while the auxiliary screw groove 5 needs to cause the diesel fuel passing through to rotate on a small scale, forming a slow acceleration at the inlet end and effectively reducing the rotation scale at the outlet end to ensure the flow cross-sectional area.

[0052] like Figure 5As shown, the width of the secondary spiral groove 5 is L1 and the depth is H1; the width of the primary spiral groove 4 is L2 and the depth is H2; the specific relationship between the width L1 and depth H1 of the secondary spiral groove 5 and the width L2 and depth H2 of the primary spiral groove 4 is L2 / 3 ≤ L1 < L2, H2 / 3 ≤ H1 < H2.

[0053] As Figure 6 shown, by spirally arranging the secondary spiral groove 5 at the inlet end and the outlet end of the inner wall of the diesel injection hole 2, and spirally arranging the primary spiral groove 4 throughout the length between the inlet end and the outlet end of the diesel injection hole 2, when the diesel in the diesel injection hole 2 moves from the inlet end to the outlet end, it first passes through the secondary spiral groove 5 at the inlet end to generate small-scale rotation and obtain preliminary acceleration, then passes through the primary spiral groove 4 to generate large-scale rotation, scouring the inner wall of the diesel injection hole 2. When flowing through the secondary spiral groove 5 at the outlet end, it turns into small-scale rotation to ensure the flow cross-sectional area and make the spraying flow rate stable.

[0054] Although the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. A dual-fuel engine injector capable of resolving nozzle clogging, comprising an injector body and a needle valve body connected to the injector body, wherein a first needle valve passes through the needle valve body, a second needle valve passes through the first needle valve, a plurality of natural gas nozzles are provided at the bottom of the needle valve body, and a plurality of diesel nozzles are provided at the bottom of the first needle valve; characterized in that, The inner wall of the diesel injection orifice contains multiple spiral grooves, including several main spiral grooves and several secondary spiral grooves; The auxiliary spiral groove is spirally arranged at the inlet and outlet ends of the diesel injection hole, and the main spiral groove is spirally arranged between the auxiliary spiral groove at the inlet end and the auxiliary spiral groove at the outlet end.

2. A dual fuel engine injector capable of resolving nozzle clogging as claimed in claim 1, wherein, The width and depth of the secondary threaded groove are both smaller than those of the primary threaded groove.

3. A dual fuel engine injector capable of resolving nozzle clogging as claimed in claim 1, wherein, The needle valve body and the first needle valve enclose each other to form a natural gas supply channel, and the first needle valve and the second needle valve enclose each other to form a diesel fuel supply channel.

4. A dual fuel engine injector capable of resolving nozzle clogging as claimed in claim 1, wherein, The multiple natural gas injection holes are evenly distributed along the circumference of the needle valve body, and the multiple diesel injection holes are evenly distributed along the circumference of the first needle valve.

5. A dual fuel engine injector capable of resolving nozzle clogging as claimed in claim 1, wherein, Both the secondary threaded groove and the primary threaded groove have rectangular cross-sections.

6. A dual fuel engine injector capable of resolving nozzle clogging as claimed in claim 1, wherein, The horizontal length of the main threaded groove is D2, and the horizontal length of the secondary threaded groove is D1; ​​the relationship between the horizontal lengths of the main threaded groove and the secondary threaded groove needs to satisfy D2 / 5≤D1≤D2 / 4.

7. A dual fuel engine injector capable of resolving nozzle clogging as claimed in claim 6 wherein, The width of the main threaded groove is L2 and the depth is H2. The relationship between L2 and D2 needs to satisfy L2 < D2 / 10 and H2 < D2 / 20.

8. A dual-fuel engine injector for resolving nozzle clogging as described in claim 7, characterized in that, The width of the secondary screw groove is L1, and the depth is H1; the relationship between L1 and L2 must satisfy: L2 / 3 < L1 < L2; the relationship between H1 and H2 must satisfy: H2 / 3 < H1 < H2.

9. A dual-fuel engine injector for resolving nozzle clogging as described in claim 1, characterized in that, The relationship between the number of secondary threaded grooves and the number of primary threaded grooves is as follows: the number of primary threaded grooves is 2-5 times that of secondary threaded grooves.

10. A dual-fuel engine injector for resolving nozzle clogging as described in claim 1, characterized in that, The optimal number of main threaded grooves is 5-10.

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