Fuel injection device of ship dual-fuel engine

Abstract

The utility model relates to a fuel injection device of a ship dual-fuel engine. The fuel injection device comprises a shell, a first-stage injection valve, a second-stage injection valve and a fuel supply system. According to the injection device, the second inlet pipe is divided into the first branch pipe and the second branch pipe which communicate with the annular cavity and the fuel inlet cavity correspondingly, so that fuel in the second inlet pipe can select different inlet channels, and during normal operation, the first inlet pipe is used for supplying first fuel and is controlled to be opened and closed through the first-stage injection valve; the first fuel enters from the first branch pipe and is sprayed out by the first-stage injection valve, the second fuel enters from the second branch pipe and is sprayed out by the second-stage injection valve, and when the first fuel is stopped for a long time, the first branch pipe is switched to enable the second fuel to pass through the annular cavity for a long time in order to enable the annular cavity to be continuously cooled by fluid. And the annular cavity can be continuously cooled, so that the inner and outer nozzles are protected from the sealing problem caused by asynchronous thermal expansion and cold contraction.

Description

Technical Field

[0001] The utility model belongs to the technical field of dual-fuel engines, and particularly relates to a fuel injection device for a marine dual-fuel engine. Background Art

[0002] A dual-fuel engine is equipped with two independent fuel supply systems, which are respectively used to supply two different fuels (such as diesel and natural gas, or diesel and a certain special liquid fuel). These two systems will mix an appropriate amount of the two fuels according to a preset fuel ratio or according to the real-time operating conditions of the engine, and then inject the mixture into the cylinder for combustion.

[0003] A dual-fuel injection device generally integrates two injection valves, which are respectively used to precisely control the injection of the two fuels. However, the fuels at the two injection ports are prone to interference during the switching process between each other. To solve this problem, Chinese Utility Model Patent No. 202110960522.6 discloses a dual-fuel injector. By arranging a needle valve in the needle valve body, the injection ports of the two fuels are nested inside and outside each other. The needle valve body and the needle valve are independently opened, and their channels do not interfere with each other. The disadvantage of this solution is that a small part of the head of the in-cylinder direct injection injector enters the cylinder. Since the temperature of the cylinder block itself is relatively high, the front end of the fuel injector is in a high-temperature environment. When the engine uses fuel for a long time due to actual situations (such as sailing to certain areas with low oil prices), the continuous injection of fuel cools the needle valve, while there is no continuous fluid cooling in the gas injection channel. The resulting thermal expansion and contraction difference leads to a decrease in sealing performance. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a fuel injection device for a marine dual-fuel engine to solve the above problems.

[0005] The utility model realizes the above purpose through the following technical solutions:

[0006] A fuel injection device for a marine dual-fuel engine, comprising

[0007] a housing, in which a fuel inlet chamber, an annular chamber and an injection hole are sequentially arranged and communicated with each other;

[0008] a primary injection valve, which includes a first valve needle passing through the fuel inlet chamber and the annular chamber to close the injection hole;

[0009] a secondary injection valve, which is arranged in the first valve needle and includes a second valve needle slidably arranged in the first valve needle. The bottom of the first valve needle has a material storage chamber and an opening. Among them, a fuel inlet communicating the fuel inlet chamber and the material storage chamber is also arranged in the first valve needle;

[0010] The fuel supply system includes a first inlet pipe and a second inlet pipe. The second inlet pipe includes a first branch pipe and a second branch pipe, each with a valve. The first inlet pipe and the first branch pipe are connected to the upper end of the annular cavity away from the injection hole, and the second branch pipe is connected to the fuel inlet cavity.

[0011] As a further optimization solution of the utility model, the shell includes an upper shell and a lower shell, wherein the fuel inlet chamber, the annular chamber and the injection hole are all arranged in the lower shell, and the first valve needle and the connecting parts of each chamber are sealed and slidably connected.

[0012] As a further optimization scheme of the utility model, the first valve needle penetrates into the upper shell and is provided with a first armature at the end. A first electromagnet for attracting the first armature and a first return spring for resetting the first armature are provided in the upper shell. Using the first armature, the first electromagnet and the first return spring as control components for opening and closing the first valve needle is prior art.

[0013] As a further optimization scheme of the utility model, a sealing groove for sliding of the second valve needle is provided in the first valve needle, and a second electromagnet is provided at the end of the first valve needle away from the opening, a second armature attracted by the second electromagnet is provided at the upper end of the second valve needle, and a second return spring is provided in the first valve needle for resetting the second armature to close the second valve needle. By arranging the second valve needle inside the first valve needle, the second valve needle uses the first valve needle as a valve housing.

[0014] As a further optimization scheme of the utility model, a switching component is arranged in the annular cavity, which is used to switch the fuel filled in the annular cavity before switching the fuel. Since the annular cavity is arranged as a cooling flow channel, both fuels enter through the upper end of the annular cavity and are sprayed out from the injection hole under long-term use. However, when the fuel is switched, the new fuel enters the annular cavity and mixes with the old residual fuel. This process makes it difficult to control the injection amount of the mixed fuel, and it is difficult to accurately match the ratio of the mixed fuel and air, which can easily cause incomplete combustion. For this reason, a switching component is arranged.

[0015] As a further optimization scheme of the utility model, the switching assembly includes an annular partition plate sliding in the annular cavity and sleeved outside the first valve needle, a slide groove is provided on the upper end side wall of the annular cavity, an annular groove is provided on the bottom end side wall of the slide groove, the first inlet pipe is connected to the annular groove through the fuel channel, a sliding cap for covering the annular partition plate is provided in the slide groove, and a guide groove extending to the upper surface is provided on the inner side wall of the annular partition plate;

[0016] Among them, the fuel channel is also connected to the bottom of the annular cavity after passing through the one-way valve. When the sliding cap is located at the lowest end of the sliding groove, the annular groove is closed. When the annular partition is located at the lowest end of the annular cavity, the bottom outer diameter of the first valve needle becomes smaller to make the guide groove conductive. When the sliding cap is pushed to the top by the annular partition, the channel between the annular cavity and the second branch pipe is closed.

[0017] In this solution, an annular partition is set as the separating component during the switching process of the two fuels, so that during the fuel switching process, the new fuel squeezes out the old fuel, preventing the two from mixing. Specifically, when the two fuels are used alternately, the first branch pipe is closed, and the fuel in the second inlet pipe enters the fuel inlet chamber through the second branch pipe and is ejected by the secondary injection valve, while the fuel in the first inlet pipe enters from the annular groove and is ejected by the primary injection valve. Since the fuel in the first inlet pipe flows through the annular chamber, a cooling effect is achieved. When the fuel in the first inlet pipe is used for a long time, it is controlled by the primary injection valve for a long time. When it is necessary to switch to the fuel in the second inlet pipe as the long-term fuel, the first inlet pipe and the second branch pipe stop supplying fuel, and the fuel is pumped into the annular chamber through the first branch pipe. The annular partition moves downward, and the fuel in the annular chamber continues to be ejected. Since the volume of the annular chamber can be determined, the position of the annular partition can be accurately judged according to the flow rate of the first branch pipe. When the annular partition reaches the lowest end, the diversion groove is opened, that is, the fuel supplied by the first branch pipe is switched to be ejected, so that this fuel can also pass through the annular chamber for cooling for a long time.

[0018] As a further optimization scheme of the present utility model, a second spring for helping the sliding cap to close the annular groove is arranged at the upper end of the annular chamber, and a third spring for helping the annular partition to move upward to close the diversion groove is also arranged at the bottom end of the annular chamber. By setting the second spring and the third spring, the response degree during the switching process can be improved. When the pressure changes, the second spring can push the sliding cap downward to quickly close the annular groove, and the third spring can push the annular partition upward, so that the diversion groove is quickly closed.

[0019] As a further optimization scheme of the present utility model, the one-way valve is opened by a pressure difference, and it includes a valve chamber arranged in the fuel passage, a valve body slidably arranged in the valve chamber, spokes arranged around the valve body, and a first spring for keeping the valve body normally closed. When the fuel in the second inlet pipe needs to be switched to the fuel in the first inlet pipe, the first inlet pipe is pressurized to push the annular partition upward from the bottom, pushing the previous fuel filled in the annular chamber back to the first branch pipe and then ejected through the second branch pipe by the secondary injection valve until the annular partition reaches the highest end, at which time the annular groove is opened, and the primary injection assembly is opened to inject the fuel in the first inlet pipe.

[0020] The beneficial effects of the present utility model are as follows:

[0021] The utility model sets the second inlet pipe as the first sub - pipe and the second sub - pipe, which are respectively connected to the annular cavity and the fuel inlet cavity, so that the fuel in the second inlet pipe can choose different entry channels. During normal operation, the first inlet pipe is used to supply the first type of fuel, and its opening and closing are controlled by the primary injection valve. The second type of fuel enters through the second sub - pipe and is ejected by the secondary injection valve. When the first type of fuel is out of use for a long time, in order to keep the annular cavity continuously cooled by fluid, the first sub - pipe is switched so that the second type of fuel passes through the annular cavity for a long time. The nested double - nozzle can not only independently and precisely control the injection volume, but also continuously cool the annular cavity, protecting the inner and outer nozzles from sealing problems caused by asynchronous thermal expansion and contraction. Description of the Drawings

[0022] Figure 1 is the overall structural sectional view of the utility model;

[0023] Figure 2 is of the utility model Figure 1 enlarged view of the structure of part A;

[0024] Figure 3 is the sectional view after the first sub - pipe of the utility model is opened;

[0025] Figure 4 is of the utility model Figure 3 enlarged view of the structure of part B;

[0026] Figure 5 is the schematic diagram of the upper shell of the utility model;

[0027] Figure 6 is of the utility model Figure 2 enlarged view of the structure of part C;

[0028] Figure 7 is the schematic diagram of the one - way valve of the utility model;

[0029] In the figure: 1. Housing; 11. Upper shell; 12. Lower shell; 13. Injection hole; 14. Annular cavity; 15. Fuel channel; 16. Fuel inlet cavity; 2. Primary injection valve; 21. First valve needle; 22. First armature; 23. First return spring; 24. First electromagnet; 3. Secondary injection valve; 31. Second valve needle; 32. Storage cavity; 33. Fuel inlet; 34. Second armature; 35. Second return spring; 36. Second electromagnet; 4. Fuel supply system; 41. First inlet pipe; 42. First sub - pipe; 43. Second sub - pipe; 44. One - way valve; 4401. Valve body; 4402. Spoke; 4403. First spring; 5. Switching component; 51. Slide groove; 52. Annular groove; 53. Sliding cap; 54. Second spring; 55. Annular partition; 56. Diversion groove; 57. Third spring. Detailed Implementation Modes

[0030] The present application will be further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0031] Embodiment 1

[0032] As Figure 1-7 shown, a fuel injection device for a marine dual-fuel engine includes

[0033] a housing 1, inside which there are sequentially arranged a fuel inlet chamber 16, an annular chamber 14 and injection holes 13 that communicate with each other;

[0034] a primary injection valve 2, which includes a first valve needle 21 that penetrates the fuel inlet chamber 16 and the annular chamber 14 to close the injection holes 13;

[0035] a secondary injection valve 3, which is arranged inside the first valve needle 21 and includes a second valve needle 31 slidably arranged inside the first valve needle 21. The bottom of the first valve needle 21 has a fuel storage chamber 32 and an opening. Among them, a fuel inlet 33 that communicates the fuel inlet chamber 16 and the fuel storage chamber 32 is also arranged inside the first valve needle 21;

[0036] a fuel supply system 4, which includes a first inlet pipe 41 and a second inlet pipe. The second inlet pipe includes a first branch pipe 42 and a second branch pipe each with a valve. The first inlet pipe 41 communicates with the first branch pipe 42 at the upper end of the annular chamber 14 away from the injection holes 13, and the second branch pipe 43 communicates with the fuel inlet chamber 16.

[0037] In this solution, by setting the second inlet pipe as the first branch pipe 42 and the second branch pipe 43, which are respectively connected to the annular chamber 14 and the fuel inlet chamber 16, the fuel in the second inlet pipe can choose different entry channels. During normal operation, the first inlet pipe 41 is used to supply the first fuel, and its opening and closing are controlled by the primary injection valve 2, while the second fuel enters through the second branch pipe 43 and is ejected by the secondary injection valve 3. When the first fuel is out of use for a long time, in order to keep the annular chamber 14 continuously cooled by fluid, the first branch pipe 42 is switched so that the second fuel passes through the annular chamber 14 for a long time. The nested double nozzles can not only independently and precisely control the injection volume, but also continuously cool the annular chamber 14, protecting the inner and outer nozzles from sealing problems caused by asynchronous thermal expansion and contraction.

[0038] The shell 1 includes an upper shell 11 and a lower shell 12, wherein the fuel inlet chamber 16, the annular chamber 14 and the injection hole 13 are all arranged in the lower shell 12, the first valve needle 21 penetrates into the upper shell 11, and is provided with a first armature 22 at the end, and a first electromagnet 24 for attracting the first armature 22 and a first return spring 23 for resetting the first armature 22 are provided in the upper shell 11. It is prior art to use the first armature 22, the first electromagnet 24 and the first return spring 23 as control components for opening and closing the first valve needle 21.

[0039] A sealing groove for the second valve needle 31 to slide is provided in the first valve needle 21, and a second electromagnet 36 is provided at the end of the first valve needle 21 away from the opening, and a second armature 34 attracted by the second electromagnet 36 is provided at the upper end of the second valve needle 31, and a second return spring 35 is provided in the first valve needle 21 for resetting the second armature 34 to close the second valve needle 31. By arranging the second valve needle 31 inside the first valve needle 21, the second valve needle 31 uses the first valve needle 21 as a valve housing, so that the second valve needle 31 has an independent opening and closing control function.

[0040] A switching assembly 5 is provided in the annular cavity 14, which is used to switch the fuel filled in the annular cavity 14 before switching the fuel. Since the annular cavity 14 is provided as a cooling flow channel, both fuels enter through the upper end of the annular cavity 14 and are ejected from the injection hole 13 under long-term use. However, when the fuel is switched, the new fuel enters the annular cavity 14 and mixes with the old residual fuel. This process makes it difficult to control the injection amount of the mixed fuel, and it is difficult to accurately match the ratio of the mixed fuel and air, which can easily cause incomplete combustion. For this reason, a switching assembly 5 is further provided.

[0041] The switching assembly 5 includes an annular partition plate 55 which slides in the annular cavity 14 and is sleeved outside the first valve needle 21. A slide groove 51 is provided on the upper side wall of the annular cavity 14, and an annular groove 52 is provided on the lower side wall of the slide groove 51. The first inlet pipe 41 is connected to the annular groove 52 through the fuel channel 15. A sliding cap 53 for covering the annular partition plate 55 is provided in the slide groove 51. A guide groove 56 extending to the upper surface is provided on the inner side wall of the annular partition plate 55.

[0042] Among them, the fuel channel 15 is also connected to the bottom of the annular cavity 14 after passing through the one-way valve 44. When the sliding cap 53 is located at the lowest end of the slide groove 51, the annular groove 52 is closed. When the annular partition 55 is located at the lowest end of the annular cavity 14, the bottom outer diameter of the first valve needle 21 becomes smaller to make the guide groove 56 conductive. When the sliding cap 53 is pushed to the top by the annular partition 55, the channel between the annular cavity 14 and the second branch pipe 43 is closed.

[0043] In this solution, an annular partition 55 is set as the separation component during the switching process of the two fuels, so that during the fuel switching process, the new fuel will squeeze out the old fuel, preventing the two from mixing. Specifically, the working conditions are generally divided into three types: AB fuels are alternately used under different load environments, A fuel is used for a long time, and B fuel is used for a long time.

[0044] When the two fuels are alternately used in the first working condition, the first branch pipe 42 is closed. The fuel in the second inlet pipe enters the fuel inlet chamber 16 through the second branch pipe 43, further enters the storage chamber 32 through the fuel inlet 33, and is ejected by the secondary injection valve 3. The fuel in the first inlet pipe 41 enters the annular chamber 14 from the annular groove 52 and is ejected by the primary injection valve 2. Since the fuel in the first inlet pipe 41 flows through the annular chamber 14, a cooling effect is achieved.

[0045] In the second working condition where A fuel is used for a long time, that is, when the fuel in the first inlet pipe 41 is used for a long time, it is controlled by the primary injection valve 2 for a long time. The second working condition is a special case of the first working condition.

[0046] In the third working condition where B fuel is used for a long time, that is, when the fuel in the second inlet pipe is used for a long time, it is switched from the first / second working condition. It is necessary to stop the supply of the first inlet pipe 41 and the second branch pipe 43, and pump the fuel through the first branch pipe 42. The annular partition 55 moves downwards to continue ejecting the fuel in the annular chamber 14. Since the volume of the annular chamber 14 can be determined, the position of the annular partition 55 can be accurately judged according to the flow rate of the first branch pipe 42 until all the A fuel in the annular chamber 14 is ejected by the annular partition 55. When the annular partition 55 reaches the lowest end, the diversion groove 56 is opened, that is, the B fuel supplied by the first branch pipe 42 is switched for injection, so that the B fuel can also be cooled by passing through the annular chamber 14 for a long time. It should be noted that in the first period when the first branch pipe 42 is opened to introduce B fuel, there is a process of exhausting A fuel in the annular chamber 14. Therefore, the flow rate in the first branch pipe 42 at this time is the flow rate of A fuel. The exhaustion of the fixed flow rate of A fuel means that the ejected fuel is B fuel. Since AB fuels require different amounts of air, accurately controlling the ejected fuel and calculating can best match the intake air volume to achieve the best combustion efficiency.

[0047] When switching back from the third working condition to the first working condition / second working condition, that is, pushing the annular partition 55 back to the top of the annular cavity 14 again. At this time, the first branch pipe 42 and the second branch pipe 43 are interconnected. The pressure of the first inlet pipe 41 enters the lower part of the annular partition 55 through the one-way valve 44. At this time, the first valve needle 21 is not opened. This pressure pushes the annular partition 55 upward. And the B fuel in the annular cavity 14 flows back to the first branch pipe 42 and passes through the second branch pipe 43, and still is ejected by the secondary injection valve 2 until the annular partition 55 pushes the sliding cap 53 upward to open the annular groove 52. At this time, the secondary injection valve 3 closes and the primary injection valve 2 opens. The A fuel fills the annular cavity 14 from bottom to top and then enters the annular cavity 14 from the annular groove 52, and then is ejected by the opening of the first valve needle 21.

[0048] A second spring 54 for helping the sliding cap 53 to close the annular groove 52 is arranged at the upper end of the annular cavity 14, and a third spring 57 for helping the annular partition 55 to move upward to close the diversion groove 56 is arranged at the bottom end of the annular cavity 14. By arranging the second spring 54 and the third spring 57, the response degree during the switching process can be improved. When the pressure direction changes, the second spring 54 can push the sliding cap 53 downward to quickly close the annular groove 52, and the third spring 57 can push the annular partition 55 upward to quickly close the diversion groove 56.

[0049] The one-way valve 44 is opened by the pressure difference. It includes a valve cavity arranged in the fuel passage 15, a valve body 4401 slidably arranged in the valve cavity, spokes 4402 arranged around the valve body 4401, and a first spring 4403 for keeping the valve body 4401 normally closed. When switching from B fuel to A fuel, the first inlet pipe 41 is pressurized to push the annular partition 55 upward from the bottom, pushing the B fuel filled in the annular cavity 14 back to the first branch pipe 42, and then it is ejected through the second branch pipe 43 by the secondary injection valve 3 until the annular partition 55 reaches the highest position, the annular groove 52 is opened, and then the primary injection assembly 2 is opened to inject the fuel in the first inlet pipe 41.

[0050] The above embodiments only represent several implementation manners of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several deformations and improvements can still be made, and these all belong to the protection scope of the present utility model.

Claims

1. A fuel injection device for a marine dual-fuel engine, characterized in that: including a housing (1) in which a fuel inlet chamber (16), an annular chamber (14) and injection holes (13) that communicate with each other in sequence are provided; a primary injection valve (2) including a first valve needle (21) that penetrates through the fuel inlet chamber (16) and the annular chamber (14) to close the injection holes (13); a secondary injection valve (3) disposed within the first valve needle (21), including a second valve needle (31) slidably disposed within the first valve needle (21), the bottom of the first valve needle (21) having a material storage chamber (32) and an opening, wherein a fuel inlet (33) that communicates the fuel inlet chamber (16) and the material storage chamber (32) is further provided within the first valve needle (21); a fuel supply system (4) including a first inlet pipe (41) and a second inlet pipe, the second inlet pipe including a first branch pipe (42) and a second branch pipe each with a valve, the first inlet pipe (41) communicating with the first branch pipe (42) at the upper end of the annular chamber (14) away from the injection holes (13), and the second branch pipe (43) communicating with the fuel inlet chamber (16).

2. The fuel injection device of a ship dual-fuel engine according to claim 1, characterized in that: The housing (1) includes an upper housing (11) and a lower housing (12), wherein the fuel inlet chamber (16), the annular chamber (14) and the injection holes (13) are all provided within the lower housing (12).

3. A fuel injection device for a marine dual-fuel engine according to claim 2, characterized in that: The first valve needle (21) penetrates into the upper housing (11) and a first armature (22) is provided at the end, a first electromagnet (24) for attracting the first armature (22) and a first return spring (23) for resetting the first armature (22) are provided within the upper housing (11).

4. A fuel injection device for a marine dual-fuel engine according to claim 1, characterized in that: A sealing groove for the second valve needle (31) to slide is provided within the first valve needle (21), and a second electromagnet (36) is provided at one end of the first valve needle (21) away from the opening, a second armature (34) attracted by the second electromagnet (36) is provided at the upper end of the second valve needle (31), and a second return spring (35) for resetting the second armature (34) to close the second valve needle (31) is provided within the first valve needle (21).

5. A fuel injection device for a marine dual-fuel engine according to claim 1, characterized in that: A switching assembly (5) is provided within the annular chamber (14) for switching the fuel filling the annular chamber (14) prior to switching fuels.

6. The fuel injection device for a marine dual-fuel engine according to claim 5, characterized in that: The switching assembly (5) includes an annular partition (55) that slides within the annular chamber (14) and is sleeved outside the first valve needle (21), a sliding groove (51) is formed in the upper sidewall of the annular chamber (14), an annular groove (52) is formed in the bottom sidewall of the sliding groove (51), the first inlet pipe (41) communicates with the annular groove (52) through a fuel passage (15), a sliding cap (53) for covering the annular partition (55) is provided within the sliding groove (51), and a diversion groove (56) extending to the upper surface is formed in the inner sidewall of the annular partition (55); Among them, the fuel passage (15) is also communicated with the lower part of the annular cavity (14) after passing through the one-way valve (44). When the sliding cap (53) is located at the lowest end of the sliding groove (51), the annular groove (52) is closed. When the annular partition plate (55) is located at the lowest end of the annular cavity (14), the outer diameter of the bottom of the first valve needle (21) becomes smaller so that the diversion groove (56) is conducted. When the sliding cap (53) is pushed to the topmost end by the annular partition plate (55), the passage between the annular cavity (14) and the second branch pipe (43) is closed.

7. A fuel injection device for a marine dual-fuel engine according to claim 6, characterized in that: A second spring (54) for helping the sliding cap (53) to close the annular groove (52) is arranged at the upper end of the annular cavity (14), and a third spring (57) for helping the annular partition plate (55) to move upward to close the diversion groove (56) is also arranged at the bottom end of the annular cavity (14).

8. A fuel injection device for a marine dual-fuel engine according to claim 6, characterized in that: The one-way valve (44) is opened by a pressure difference and includes a valve cavity arranged in the fuel passage (15), a valve body (4401) slidably arranged in the valve cavity, spokes (4402) arranged around the valve body (4401), and a first spring (4403) for keeping the valve body (4401) normally closed.

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