Dual-fuel nozzle structure with small-volume pressure chamber

Abstract

The utility model relates to a dual-fuel nozzle structure with a small-volume pressure chamber, which comprises a valve body, an outer needle and an inner needle, the outer needle is coaxially arranged in the valve body, the inner needle is coaxially arranged in the outer needle, a first fuel energy storage cavity and a first small-volume fuel pressure chamber are arranged between the valve body and the outer needle, and a second fuel energy storage cavity is arranged between the valve body and the inner needle. A second fuel energy storage cavity and a second small-volume fuel pressure chamber are arranged between the outer needle and the inner needle. A first sealing seat face is arranged on the inner wall of the valve body, a second sealing seat face is arranged on the outer wall of the outer needle, the first sealing seat face abuts against the second sealing seat face, a third sealing seat face is arranged on the inner wall of the outer needle, a fourth sealing seat face is arranged on the outer wall of the inner needle, and the third sealing seat face abuts against the fourth sealing seat face. The nozzle is provided with the fuel pressure chamber containing cavity with the small size, flow stabilizing cavities can be provided for injection of two kinds of fuel respectively, the influence of the coaxiality difference of parts on the spray dispersion difference is reduced, and the uniformity and stability of fuel injection can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of injectors, in particular to a dual-fuel nozzle structure with a small-volume pressure chamber. Background Art

[0002] With the upgrading of national emission regulations, energy types are becoming more and more diversified. More and more energy sources are gradually being developed and utilized due to their cleanness or renewability. Commonly used fuels include natural gas, hydrogen, methanol, ethanol, butanol, ammonia and other fuels. In order to make these clean fuels have better combustion and emission effects, the commonly used technology is dual-fuel injection technology, which is to inject two fuels into the combustion chamber according to the requirements set by the system, and one fuel plays the role of ignition or combustion support for the other fuel. The injector that realizes the injection of two fuels is called a dual-fuel injector, which usually requires two independent nozzles to inject the two fuels respectively. How to achieve a compact and efficient arrangement of two nozzles in the narrow engine installation space, and make the injection of the two fuels have better atomization performance and less tail spray has become a key issue for dual-fuel nozzles. Summary of the Invention

[0003] The utility model provides a dual-fuel nozzle structure with a small-volume pressure chamber to improve the uniformity and stability of fuel injection and reduce the tail spray volume when the nozzle is closed, thereby solving the technical problems in the background technology.

[0004] The technical solution of the present utility model is as follows: A dual-fuel nozzle structure with a small-volume pressure chamber comprises: a valve body, an outer needle, and an inner needle, wherein the outer needle is coaxially arranged inside the valve body, and the inner needle is coaxially arranged inside the outer needle, a first fuel accumulator chamber and a first small-volume fuel pressure chamber are defined between the valve body and the outer needle, and a second fuel accumulator chamber and a second small-volume fuel pressure chamber are defined between the outer needle and the inner needle;

[0005] A first sealing seat surface is provided on the inner wall of the valve body, and a second sealing seat surface is provided on the outer wall of the outer needle. The first sealing seat surface abuts the second sealing seat surface. The first sealing seat surface and the second sealing seat surface are located between the first fuel accumulator chamber and the first small-volume fuel pressure chamber. The first fuel accumulator chamber is located above the first small-volume fuel pressure chamber. A guide hole is provided on the inner wall of the valve body, and a guide section is provided on the outer wall of the outer needle. The guide hole and the guide section are clearance-matched. The guide hole and the guide section are located below the first small-volume fuel pressure chamber. The first small-volume fuel pressure chamber is connected to at least one first fuel injection hole.

[0006] A third sealing seat surface is provided on the inner wall of the outer needle, and a fourth sealing seat surface is provided on the outer wall of the inner needle. The third sealing seat surface abuts against the fourth sealing seat surface. The third sealing seat surface and the fourth sealing seat surface are located between the second fuel energy storage chamber and the second small-volume fuel pressure chamber. The second fuel energy storage chamber is located above the second small-volume fuel pressure chamber. The second small-volume fuel pressure chamber is connected to at least one second fuel nozzle.

[0007] Furthermore, a slope is provided on the inner wall of the valve body, and the slope is located below the first sealing seat surface. A groove surface recessed inward is provided on the outer wall of the outer needle, and a first small-volume fuel pressure chamber is formed between the slope and the groove surface.

[0008] Furthermore, the first fuel injection hole is located on the inclined surface.

[0009] Furthermore, an arc segment is provided on the inner wall of the outer needle, the needle head of the inner needle is a plane, and the second small-volume fuel pressure chamber is formed between the arc segment and the needle head of the inner needle.

[0010] Furthermore, the second fuel injection hole is located on the arc segment.

[0011] Furthermore, an inclined surface section and a flat surface section are provided on the inner wall of the outer needle, the flat surface section is located at the bottom of the inclined surface section, and the second small-volume fuel pressure chamber is formed between the inclined surface section, the flat surface section and the needle head of the inner needle.

[0012] The beneficial effects of this utility model include: The first and second small-volume fuel pressure chambers are relatively small, providing a stabilizing chamber for each fuel injection, reducing the impact of component coaxiality differences on spray dispersion and helping to improve the uniformity and stability of fuel injection. Furthermore, the small volume of the stabilizing chamber reduces the tail spray volume when the nozzle is closed, contributing to efficient and clean combustion while also suppressing the formation of carbon deposits. The utility model has a compact structure and offers excellent component manufacturability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural diagram of the first embodiment of the present utility model.

[0014] Figure 2 It is a structural diagram of the second embodiment of the present utility model. DETAILED DESCRIPTION

[0015] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts should fall within the scope of protection of the present invention.

[0016] In one embodiment of the present invention, Figure 1 This is a structural diagram of a dual-fuel nozzle structure with a small volume pressure chamber according to the present invention. Figure 1 As shown, the utility model includes:

[0017] The valve body 1, the outer needle 2 and the inner needle 3 are coaxially arranged inside the valve body 1 and can reciprocate axially inside the valve body 1. The inner needle 3 is coaxially arranged inside the outer needle 2 and can reciprocate axially inside the outer needle 2.

[0018] A first fuel storage chamber 13 and a first small-volume fuel pressure chamber 17 are defined between the valve body 1 and the outer needle 2 , and a second fuel storage chamber 14 and a second small-volume fuel pressure chamber 15 are defined between the outer needle 2 and the inner needle 3 .

[0019] A first sealing seat 4 is provided on the inner wall of the valve body 1, and a second sealing seat 6 is provided on the outer wall of the outer needle 2. The first sealing seat 4 abuts the second sealing seat 6, and the connecting area between the first sealing seat 4 and the second sealing seat 6 forms a first sealing surface 7. The first sealing seat 4 and the second sealing seat 6 are located between the first fuel accumulator chamber 13 and the first small-volume fuel pressure chamber 17. The first fuel accumulator chamber 13 is located above the first small-volume fuel pressure chamber 17. A guide hole 8 is provided on the inner wall of the valve body 1, and a guide section 9 is provided on the outer wall of the outer needle 2. The guide hole 8 and the guide section 9 have a clearance fit. The guide hole 8 and the guide section 9 are located below the first small-volume fuel pressure chamber 17. The first small-volume fuel pressure chamber 17 is connected to at least one first fuel injection hole 18.

[0020] Specifically, the inner wall of the valve body 1 is provided with a sloped surface 5, located below the first sealing seat surface 4. The outer wall of the outer needle 2 is provided with an inwardly recessed groove, forming a first small-volume fuel pressure chamber 17 between the sloped surface 5 and the groove. A first fuel injection hole 18 is located on the sloped surface 5. The volume of the first small-volume fuel pressure chamber 17 is less than 2.5 mm³, and the maximum distance between the sloped surface 5 and the outer wall of the outer needle 2 is less than 0.3 mm.

[0021] A third sealing surface 10 is provided on the inner wall of the outer needle 2, and a fourth sealing surface 11 is provided on the outer wall of the inner needle 3. The third sealing surface 10 abuts against the fourth sealing surface 11, and the connecting area between the third sealing surface 10 and the fourth sealing surface 11 forms a second sealing surface 12. The third sealing surface 10 and the fourth sealing surface 11 are located between a second fuel accumulator chamber 14 and a second small-volume fuel pressure chamber 15. The second fuel accumulator chamber 14 is located above the second small-volume fuel pressure chamber 15, and the second small-volume fuel pressure chamber 15 is connected to at least one second fuel injection hole 16.

[0022] Specifically, the inner wall of the outer needle 2 is provided with an arc segment 19. The tip of the inner needle 3 is flat, forming the second small-volume fuel pressure chamber 15 between the arc segment 19 and the tip of the inner needle 3. The second fuel injection hole 16 is located on the arc segment 19. The volume of the second small-volume fuel pressure chamber 15 is less than 0.35 mm³, and the maximum distance between the arc segment 19 and the bottom of the inner needle 3 is less than 0.4 mm.

[0023] In the second embodiment of the present invention, Figure 2 As shown, an inclined surface section 20 and a flat surface section 21 are provided on the inner wall of the outer needle 2. The flat surface section 21 is located at the bottom of the inclined surface section 20. The second small-volume fuel pressure chamber 15 is formed between the inclined surface section 20, the flat surface section 21 and the needle head of the inner needle 3.

[0024] The operating principle of this utility model is as follows: when the valve body 1 and the outer needle 2 are in contact, the first sealing surface 7 separates the first fuel storage chamber 13 from the first small-volume fuel pressure chamber 17. When the outer needle 2 moves axially upward, the first sealing surface 7 opens to form a passage, allowing the fuel in the first fuel storage chamber 13 to flow out of the first fuel injection hole 18. When the outer needle 2 and the inner needle 3 are in contact, the second sealing surface 12 separates the second fuel storage chamber 14 from the second small-volume fuel pressure chamber 15. When the inner needle 3 moves axially upward, the second sealing surface 12 opens to form a passage, allowing the fuel in the second fuel storage chamber 14 to flow out of the second fuel injection hole 16.

[0025] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the utility model and are not limiting. Although the utility model is described in detail with reference to examples, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A dual-fuel nozzle structure with a small-volume pressure chamber, characterized in that: include: A valve body (1), an outer needle (2) and an inner needle (3), wherein the outer needle (2) is coaxially arranged inside the valve body (1), and the inner needle (3) is coaxially arranged inside the outer needle (2); a first fuel storage chamber (13) and a first small-volume fuel pressure chamber (17) are provided between the valve body (1) and the outer needle (2); and a second fuel storage chamber (14) and a second small-volume fuel pressure chamber (15) are provided between the outer needle (2) and the inner needle (3); A first sealing seat surface (4) is provided on the inner wall of the valve body (1), and a second sealing seat surface (6) is provided on the outer wall of the outer needle (2). The first sealing seat surface (4) abuts against the second sealing seat surface (6). The first sealing seat surface (4) and the second sealing seat surface (6) are located between the first fuel accumulator cavity (13) and the first small-volume fuel pressure chamber (17). The first fuel accumulator cavity (13) is located above the first small-volume fuel pressure chamber (17). A guide hole (8) is provided on the inner wall of the valve body (1), and a guide section (9) is provided on the outer wall of the outer needle (2). The guide hole (8) and the guide section (9) are clearance-matched. The guide hole (8) and the guide section (9) are located below the first small-volume fuel pressure chamber (17). The first small-volume fuel pressure chamber (17) is connected to at least one first fuel injection hole (18). A third sealing seat surface (10) is provided on the inner wall of the outer needle (2), and a fourth sealing seat surface (11) is provided on the outer wall of the inner needle (3). The third sealing seat surface (10) abuts against the fourth sealing seat surface (11). The third sealing seat surface (10) and the fourth sealing seat surface (11) are located between a second fuel energy storage chamber (14) and a second small-volume fuel pressure chamber (15). The second fuel energy storage chamber (14) is located above the second small-volume fuel pressure chamber (15). The second small-volume fuel pressure chamber (15) is connected to at least one second fuel injection hole (16).

2. The dual fuel nozzle structure with a small volume pressure chamber according to claim 1, characterized in that: The inner wall of the valve body (1) is provided with an inclined surface (5), and the inclined surface (5) is located below the first sealing seat surface (4). The outer wall of the outer needle (2) is provided with a groove surface that is recessed inward, and a first small-volume fuel pressure chamber (17) is formed between the inclined surface (5) and the groove surface.

3. The dual-fuel nozzle structure with a small-volume pressure chamber according to claim 2, characterized in that: The first fuel injection hole (18) is located on the inclined surface (5).

4. The dual-fuel nozzle structure with a small-volume pressure chamber according to claim 1, wherein: An arc segment (19) is provided on the inner wall of the outer needle (2), the needle head of the inner needle (3) is a plane, and the second small-volume fuel pressure chamber (15) is formed between the arc segment (19) and the needle head of the inner needle (3).

5. The dual-fuel nozzle structure with a small-volume pressure chamber according to claim 4, characterized in that: The second fuel injection hole (16) is located on the circular arc segment (19).

6. The dual-fuel nozzle structure with a small-volume pressure chamber according to claim 1, wherein: An inclined surface section (20) and a flat surface section (21) are provided on the inner wall of the outer needle (2), the flat surface section (21) being located at the bottom of the inclined surface section (20), and the second small-volume fuel pressure chamber (15) is formed between the inclined surface section (20), the flat surface section (21) and the needle head of the inner needle (3).

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