Ammonia fuel injection valve

Abstract

The invention discloses an ammonia fuel injection valve, and relates to the technical field of diesel engines. The injection valve is mainly composed of an injection valve body and a distribution block. A fuel leakage recovery passage and a fuel gas purging passage are integrally designed in the valve body, and the leakage recovery passage penetrates through the valve body and the distribution block and is communicated with all key sealing cavities in the valve body, so that ammonia fuel leaked due to failure of a sealing surface can be actively collected and guided out, and leakage of the ammonia fuel is prevented. The purge passage can guide a purge medium (such as nitrogen) to thoroughly remove residual ammonia in all fuel channels in the valve during mode switching through a one-way valve driven by control gas. Through the dual safety mechanism, the leakage risk caused by ammonia fuel toxicity is effectively solved, and the safety of the injection valve and the whole engine system is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of diesel engines and dual-fuel engines, and particularly relates to an ammonia fuel injection valve with internal leakage recovery and gas purging functions, which is suitable for ship power systems and other engine systems using ammonia as clean fuel. BACKGROUND

[0002] With the increasing requirements of the International Maritime Organization for controlling carbon emissions from ships, dual-fuel main engines have become an inevitable trend in the development of future marine diesel engines, and the development and use of various clean fuels have become an important direction of research on marine diesel engines.

[0003] Ammonia fuel, as a high-quality clean fuel recognized by the world, has been valued by many ship design and manufacturing powers around the world. Its advantages are high conversion efficiency, zero carbon emissions, and renewable energy. However, ammonia gas is highly toxic, and once leaked, it will pose a serious threat to personnel safety, which poses extremely high requirements for its safe use in engine systems.

[0004] The ammonia fuel injection valve, as the core component of the ammonia fuel supply system, its sealing performance and leakage prevention capability are directly related to the safety and reliability of the entire system. Traditional gas injection valves are usually designed for low-toxic or non-toxic fuels, and their sealing structure is relatively simple, usually relying only on a sealing oil circuit to achieve basic sealing, with the possibility of slight leakage. Such a structure, when matched with a leakage detection device, can still meet the requirements of using low-toxic fuels. However, for ammonia fuel, even a small amount of leakage can cause serious consequences, so the traditional injection valve cannot meet the safety operation requirements of ammonia fuel engines.

[0005] In the prior art, some dual-fuel main engines are equipped with a gas purging system, but its purging range is usually limited to the external pipelines and distribution blocks of the injection valve, and does not involve cleaning the internal passages of the injection valve. When the engine is switched from gas mode to oil mode, if the residual ammonia gas in the valve cannot be completely removed, there is still a risk of internal residual fuel leakage.

[0006] Therefore, there is an urgent need for a new type of ammonia fuel injection valve with internal leakage recovery and comprehensive purging functions to solve the safety problems of ammonia fuel during storage, injection, and mode switching. SUMMARY

[0007] The present application aims to solve the problem of poor safety and leakage risk of conventional gas injection valves, and provides a new type of injection valve with fuel leakage recovery function and gas purging function inside, which ensures that even if there is leakage between the internal part connecting surfaces when the gas mode is running, the fuel can be recovered and processed through the internal passage. And when the host switches to oil mode, the internal passage of the injection valve can be purged and the internal toxic gas can be emptied.

[0008] The technical solution of the present application to solve its technical problems is as follows: An ammonia fuel injection valve, comprising an injection valve body and a distribution block, characterized in that: the distribution block is fixedly installed on the side surface of the injection valve body, and is provided with a fuel inlet, a fuel return inlet, a sealing air inlet, a fuel leakage recovery inlet and a purging control inlet; The injection valve body is internally formed with: A fuel injection passage, the inlet end of which is in communication with the fuel inlet on the distribution block, and the outlet end of which extends to the nozzle; At least one sealing cavity, which is formed by the assembly surface of the adjacent parts inside the injection valve body; A fuel leakage recovery passage, which is independent of the fuel injection passage and penetrates through the injection valve body and the distribution block, and is in communication with the fuel leakage recovery inlet on the distribution block, for collecting and discharging the fuel leaked from the fuel injection passage to the sealing cavity; A gas purging passage, which includes a driving gas path formed in the distribution block and the injection valve body and in communication with the purging control inlet, and a return gas passage in communication with the fuel return inlet; the driving gas path is configured to accept external purging medium and control the opening of the one-way valve arranged in the return gas passage, so that the purging medium flowing from the fuel inlet can flow through the fuel injection passage and be discharged from the fuel return inlet through the opened one-way valve.

[0009] Further, the distribution block is fixedly connected to the side surface of the injection valve body by bolts.

[0010] Further, the fuel leakage recovery passage is configured to be in communication with all the sealing cavities inside the injection valve body.

[0011] Further, the one-way valve is arranged on the connecting passage between the fuel return inlet and the internal fuel return path; the purging medium flowing into the purging control inlet acts on the control end of the one-way valve, and when its pressure exceeds the preset value, the one-way valve is driven to open, thereby connecting the fuel injection passage and the fuel return inlet.

[0012] Further, the purging medium is nitrogen.

[0013] Further, the fuel injection passage includes an ammonia inlet channel, a fuel cavity and a pressure accumulation cavity connected in sequence, and the pressure accumulation cavity is connected with the nozzle through a nozzle controlled by a needle valve and a spring.

[0014] Further, the fuel is ammonia fuel.

[0015] Compared with the prior art, the technical effects of the present application are as follows: 1) A dedicated fuel recovery passage covering all key sealing cavities is constructed inside the valve body. The potential leakage is guided to the recovery system, and passive protection is changed to active collection and treatment, so that the possibility of ammonia leakage to the external environment through the sealing surface is fundamentally eliminated. The recovery function of internal fuel leakage is increased, and even in the case of slight failure of the internal sealing surface, the leaked fuel can be collected and treated through the recovery passage, avoiding the possibility of leakage to the surrounding environment.

[0016] 2) The limitation of the conventional purge system only for external pipelines is broken, and the purge function is deeply integrated into the injection valve in the present application. Through the synergistic effect of a specific control interface and a one-way valve, the residual fuel gas in the complex flow channel inside the injection valve can be completely removed, and the safety hazard caused by the residual toxic gas in the valve during mode switching is solved. The main machine can completely remove the residual fuel gas in the valve by purging nitrogen when switching to the fuel oil mode, avoiding the possibility of internal residual toxic fuel gas leakage. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 For the ammonia fuel injection valve assembly of the present application Figure 2 For the ammonia fuel ammonia inlet and injection passage sectional view Figure 3 For the lateral view of the injection valve Figure 4 For the partial enlarged view of the distribution block ATTACHMENT Figure 5 For the front view of the injection valve Figure 6 For the A-A sectional view of the front view IN THE DRAWINGS, 1-injection valve body, 2-distribution block, 3-piston, 4-nozzle 5-spring, 6-needle valve, 7-one-way valve A-fuel inlet, B-fuel return (purge return), C-sealing air port D-fuel leakage recovery port, E-purge control port, F-driving oil port G-fuel cavity, H-pressure accumulation cavity, K-sealing cavity DETAILED DESCRIPTION The application will be further described in conjunction with the drawings and specific embodiments, but cannot limit the protection scope of the application.

[0018] A fuel injection valve composed of an injection valve body with internal recycling and purging function and a distribution block, avoiding ammonia fuel leakage, greatly improving the safety of the injection valve. The distribution block is arranged with fuel inlet and return pipe interface, fuel recycling interface, gas purging control interface. The distribution block is connected to the side of the injection valve body by bolts, and each pipeline interface is connected with the internal passage of the injection valve through the distribution block. The injection valve has internal fuel injection oil inlet passage, sealed air passage, fuel recycling passage and gas purging passage. The fuel recycling passage can be connected to all fuel sealing cavities inside the injection valve, and all the leaked fuel in the sealing cavities can be recycled through the pipeline connected by the distribution block. The injection valve also has a passage for gas purging and a gas purging control passage, which can discharge the remaining toxic fuel by purging nitrogen into the internal passage.

[0019] Please refer to Figure 1 and Figure 2 , when running in gas mode, ammonia fuel enters from the fuel inlet A, fills the fuel chamber G through the green ammonia inlet channel, when the injection valve works, the drive oil enters from the drive oil port F, pushes the piston 3 to move, pressurizes the ammonia fuel in the fuel chamber G, and pressurizes the ammonia fuel in the fuel chamber G through the red channel to the pressure chamber H inside the nozzle 4, the pressure chamber H and the nozzle hole are sealed by the needle valve 6 connected by the spring 5, when the pressure in the pressure chamber H reaches 330bar, the pressure exceeds the preset injection pressure of the spring 5, at this time the needle valve 6 pushes the spring 5 to compress and opens the nozzle, and the fuel is sprayed from the nozzle 4.

[0020] Due to the detailed structure of gas injection drive and sealed air passage, etc. similar to traditional injection valve, it is not repeated here, the following focuses on the detailed description of the internal leakage recycling function and purging function of the injection valve 1. Internal leakage recycling function Please refer to Figure 1 , Figure 3 , Figure 4 , the injection valve body 1 and the distribution block 2 have internal channels (light blue) for internal leakage recycling, which are connected to each sealing cavity K in the injection valve body. When the injection valve is running normally, due to the existence of the sealing ring on each sealing surface, the ammonia fuel only exists in the internal normal ammonia channel (green, red, yellow area), but once the sealing ring has a slight failure, the ammonia fuel will enter the sealing cavity K through the position of the sealing ring. Since all sealing cavities K are connected to the internal leakage recycling channel, the leaked ammonia gas can be discharged from the ammonia internal leakage recycling port D through the internal leakage recycling channel and treated subsequently, without leaking to the surrounding environment.

[0021] 2. Purging function Please refer to the attached drawings Figure 4 , Figure 5 , Figure 6 When the injection valve is working normally, the one-way valve 7 connected to the ammonia return port B is closed because the ammonia fuel system is in a high pressure state, and the ammonia fuel fills the internal passage of the injection valve (red, green, and yellow areas). When the ammonia fuel system is to be purged, the ammonia system pressure is reduced to 22 bar, at which time the 30 bar control nitrogen gas (dark blue) introduced from the purge control port E can push the one-way valve 7 to open. After the one-way valve 7 is opened, the ammonia return passage (yellow) in the injection valve is connected to the ammonia return port B. At the same time, the purge nitrogen gas is filled into the injection valve from the ammonia inlet port A to purge the internal passage (red, green, and yellow areas) and discharge the remaining ammonia fuel from the ammonia return port B, so as to avoid leakage of the remaining ammonia gas to the surrounding environment.

[0022] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which do not affect the essential content of the present application. The above embodiments and features in the embodiments can be combined with each other without conflict.

Claims

1. An ammonia fuel injection valve comprising an injection valve body (1) and a distribution block (2), characterized in that: The distribution block (2) is fixedly installed on the side of the injection valve body (1), and is provided with a fuel inlet (A), a fuel return (B), a seal air inlet (C), a fuel leakage recovery inlet (D) and a purge control inlet (E); The injection valve body (1) is internally formed with: A fuel injection passage, the inlet end of which is communicated with the fuel inlet (A) on the distribution block (2), and the outlet end of which extends to the nozzle (4); At least one seal cavity (K) formed by the assembly surface of the adjacent parts in the injection valve body (1); A fuel leakage recovery passage, which is independent of the fuel injection passage, and penetrates through the injection valve body (1) and the distribution block (2), and is communicated with the fuel leakage recovery inlet (D) on the distribution block (2) and the at least one seal cavity (K), for collecting and discharging the fuel leaked from the fuel injection passage to the seal cavity (K); A gas purge passage, which includes a driving gas path formed in the distribution block (2) and the injection valve body (1) and communicated with the purge control inlet (E), and a return gas passage communicated with the fuel return (B); the driving gas path is configured to accept an external purge medium and control the opening of a one-way valve (7) arranged in the return gas passage, so that the purge medium introduced from the fuel inlet (A) can flow through the fuel injection passage and be discharged from the fuel return (B) through the opened one-way valve (7).

2. The ammonia fuel injection valve according to claim 1, characterized by The distribution block (2) is fixedly connected to the side of the injection valve body (1) by bolts.

3. The ammonia fuel injection valve according to claim 1, characterized by, The fuel leakage recovery passage is configured to be communicated with all the seal cavities (K) in the injection valve body (1).

4. The ammonia fuel injection valve according to claim 1, characterized by The one-way valve (7) is arranged on the connecting passage between the fuel return (B) and the internal fuel return circuit; the purge medium introduced from the purge control inlet (E) acts on the control end of the one-way valve (7), and when the pressure thereof exceeds a preset value, the one-way valve (7) is driven to open, thereby connecting the fuel injection passage and the fuel return (B).

5. The ammonia fuel injection valve according to claim 4, characterized by The purge medium is nitrogen.

6. The ammonia fuel injection valve according to claim 1, characterized by The fuel injection passage includes a fuel cavity (G) and a pressure accumulation cavity (H) sequentially communicated with an ammonia inlet channel; the pressure accumulation cavity (H) is communicated with the nozzle (4) through a nozzle controlled by a needle valve (6) and a spring (5).

7. The ammonia fuel injection valve according to claim 1, characterized by The fuel is ammonia fuel.

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