Ammonia fuel reforming system and method suitable for ammonia fuel engine

Abstract

The invention discloses an ammonia fuel reforming system suitable for an ammonia fuel engine and a control method. The system comprises a liquid ammonia supply device, an ammonia gas supply device, an ammonia gas preheating device, an ammonia decomposition device, a pressurizing device, a mixed gas buffering and spraying device and a control system. The ammonia decomposition device adopts a plasma concerted catalysis ammonia decomposition reactor and is matched with a non-noble metal-based catalyst; the ammonia gas preheating device preheats ammonia gas through engine exhaust gas waste heat. The control method comprises the steps that gaseous ammonia is stably output after liquid ammonia is gasified and subjected to pressure regulation and enters the ammonia decomposition device after being preheated through waste gas waste heat, ammonia-hydrogen mixed gas is generated, the ammonia-hydrogen mixed gas is cached and sprayed to an engine gas inlet pipeline after being pressurized, and the control system regulates and controls all the devices to operate according to detection parameters. The system can improve the problem of low ammonia combustion speed, does not need independent hydrogen storage, is high in energy utilization rate and low in cost, and realizes zero carbon emission.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engines, and more particularly to an ammonia fuel reforming system suitable for ammonia fuel engines. Background Technology

[0003] Liquid ammonia storage is an important approach to hydrogen storage in the future. Compared to hydrogen fuel, ammonia fuel, as a zero-carbon fuel, has mature industrial production, storage, and transportation facilities, and is more advantageous in terms of cost and safety, and is regarded as a new alternative fuel for traditional engines.

[0004] However, the application of ammonia fuel in engines faces numerous limitations. A key issue is the slow flame propagation speed of ammonia, only about one-sixth that of gasoline, which easily leads to incomplete combustion in the engine. To address the slow combustion speed of ammonia, from a zero-carbon emission perspective, ammonia engines can operate using hydrogen blending, as illustrated by Chinese invention patents with application numbers 202011331827.2 and 202210147720.5. Hydrogen blending primarily originates from hydrogen storage and online hydrogen production. Among these, online hydrogen production technology using ammonia catalytic decomposition based on engine exhaust heat avoids the high safety risks and transportation costs associated with hydrogen storage. Ruthenium-based and other precious metal catalysts possess excellent catalytic performance, but their high price limits their large-scale industrial application. In contrast, non-precious metal catalysts are cheaper. However, non-precious metal-based ammonia decomposition catalysts have high activity temperatures (>550 ℃), which are difficult to meet using only engine exhaust temperature, making them unsuitable for fuel reforming in ammonia engines. Summary of the Invention

[0005] This invention proposes an ammonia fuel reforming system suitable for ammonia fuel engines. It utilizes low-temperature plasma synergistic catalysis technology to improve the low-temperature activity of the catalyst, enabling the application of inexpensive, non-precious metal-based ammonia decomposition catalytic systems to ammonia fuel reforming in ammonia engines.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An ammonia fuel reforming system suitable for ammonia fuel engines, comprising: A liquid ammonia supply unit is used to supply liquid ammonia and vaporize and regulate its pressure; An ammonia supply device, connected to the outlet of the liquid ammonia supply device, is used to stably supply gaseous ammonia and detect its state parameters; An ammonia preheating device is connected to the outlet of the ammonia supply device and is used to preheat ammonia using the waste heat from the exhaust gas of the ammonia fuel engine. An ammonia decomposition device is connected to the outlet of the ammonia preheating device and is used to decompose ammonia to generate an ammonia-hydrogen mixture. A pressurizing device, connected to the outlet of the ammonia decomposition device, is used to pressurize the ammonia-hydrogen mixture. A mixture buffer and injection device is connected to the outlet of the pressurization device and is used to buffer the pressurized ammonia-hydrogen mixture and inject it into the intake pipe of the ammonia fuel engine. The control system is electrically connected to the ammonia supply device, ammonia decomposition device, pressurization device, mixed gas buffer and injection device, respectively, and is used to adjust the operating status of each device according to the detection parameters.

[0007] In a preferred embodiment, the ammonia decomposition device includes a plasma-co-catalyzed ammonia decomposition reactor and a high-voltage power supply. The plasma-co-catalyzed ammonia decomposition reactor includes a segmented ammonia decomposition catalyst and a plasma discharge region, with the ammonia decomposition catalyst placed downstream of the plasma discharge region. The high-voltage power supply is electrically connected to the plasma discharge region and is used to provide discharge to the plasma discharge region.

[0008] In the preferred embodiment, the plasma-co-catalyzed ammonia decomposition reactor adopts a corona discharge method.

[0009] In a preferred embodiment, the ammonia decomposition catalyst includes at least one of iron-based catalysts, nickel-based catalysts, cobalt-based catalysts, and copper-based catalysts.

[0010] In a preferred embodiment, the liquid ammonia supply device includes a liquid ammonia storage tank and a pressure reducing valve. The outlet of the liquid ammonia storage tank is connected to the inlet of the pressure reducing valve, and the outlet of the pressure reducing valve is connected to the inlet of the ammonia supply device. The pressure reducing valve is used to reduce the outlet pressure of the liquid ammonia storage tank to the inlet pressure required by the ammonia pressure stabilizing tank.

[0011] In a preferred embodiment, the ammonia supply device includes an ammonia pressure stabilizing tank, a second temperature and pressure sensor, and an ammonia flow controller. The inlet of the ammonia pressure stabilizing tank is connected to the outlet of the liquid ammonia supply device, and the outlet of the ammonia pressure stabilizing tank is connected to the inlet of the ammonia preheating device. The ammonia flow controller is installed on the pipeline between the ammonia pressure stabilizing tank and the ammonia preheating device, and the second temperature and pressure sensor is installed on the ammonia pressure stabilizing tank.

[0012] In a preferred embodiment, the ammonia preheating device includes an ammonia preheater, an ammonia engine exhaust pipe, and a temperature sensor. The inlet of the ammonia preheater is connected to the outlet of the ammonia supply device, and the outlet of the ammonia preheater is connected to the inlet of the ammonia decomposition device. The ammonia preheater and the exhaust gas from the ammonia engine exhaust pipe exchange heat in a countercurrent manner. The temperature sensor is installed on the ammonia engine exhaust pipe.

[0013] In a preferred embodiment, the pressurizing device includes a pressurizing pump, the inlet of which is connected to the outlet of the ammonia decomposition device, and the outlet of which is connected to the inlet of the mixed gas buffer and injection device.

[0014] In a preferred embodiment, the gas mixture buffer and injection device includes a gas rail and a nozzle. The gas rail is used to buffer the pressurized ammonia-hydrogen mixture. The gas rail inlet is connected to the outlet of the pressurization device, and the gas rail outlet is connected to the nozzle inlet. A first temperature and pressure sensor is installed on the gas rail, and the nozzle is installed on the intake pipe of the ammonia fuel engine.

[0015] A control method for an ammonia fuel reforming system suitable for an ammonia fuel engine, the control method comprising: S1. Liquid ammonia is supplied through a liquid ammonia supply device and vaporized and pressure regulated, and gaseous ammonia is stably output through an ammonia supply device. S2. Using an ammonia preheating device, the waste heat from the exhaust gas of an ammonia fuel engine is used to preheat the gaseous ammonia. S3. Introduce the preheated ammonia gas into the ammonia decomposition device to decompose the ammonia and generate an ammonia-hydrogen mixture with a hydrogen gas integral of 5%-15%. S4. After the ammonia-hydrogen mixture is pressurized by the pressurizing device, it is buffered by the mixture buffer and injection device and injected into the intake pipe of the ammonia fuel engine. S5. The control system adjusts the ammonia supply, the operating parameters of the ammonia decomposition unit, the pressurization pressure, the injection timing of the mixture, and the engine ignition timing based on the detected status parameters.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention provides an ammonia fuel reforming system and control method suitable for ammonia fuel engines. The system generates an ammonia-hydrogen mixture through an ammonia decomposition device and uses hydrogen as a combustion aid, which effectively improves the in-cylinder combustion process of ammonia fuel engines and overcomes the problems of slow flame propagation speed of ammonia fuel (only about 1 / 6 of that of gasoline) and easy incomplete combustion. This enables pure ammonia engines to operate stably and achieve zero carbon emissions.

[0017] 2. This invention uses catalytic ammonia decomposition to produce hydrogen and obtains ammonia-hydrogen mixed fuel. The system does not require separate storage devices for ammonia fuel and hydrogen fuel, which simplifies the system structure, reduces the high safety risks and storage and transportation costs associated with hydrogen storage, and improves system safety.

[0018] 3. The ammonia preheating device of this invention utilizes the waste heat of the exhaust gas from an ammonia-fueled engine to preheat the ammonia through countercurrent heat exchange, making full use of energy, reducing the energy consumption of the plasma reactor, and further improving the ammonia decomposition efficiency. By employing plasma-assisted catalysis technology in conjunction with a non-precious metal-based catalyst, the problem of high activity temperature (>550°C) of non-precious metal-based catalysts, which cannot be met by relying solely on engine exhaust temperature, is solved, thus improving the ammonia decomposition efficiency of the non-precious metal catalyst. Compared with precious metal catalysis systems, this significantly reduces costs and facilitates large-scale industrial applications. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of the ammonia fuel reforming system applicable to ammonia fuel engines according to the present invention.

[0020] Figure 2 This is a schematic diagram of the plasma-co-catalyzed ammonia decomposition reactor of the present invention.

[0021] In the diagram: 1. Ammonia engine intake pipe; 2. Nozzle; 3. Air rail; 4. First temperature and pressure sensor; 5. Pressurization pump; 6. High-voltage power supply; 7. Electronic control unit (ECU); 8. Temperature sensor; 9. Ammonia engine exhaust pipe; 10. Second temperature and pressure sensor; 11. Ammonia pressure stabilizing tank; 12. Pressure reducing valve; 13. Liquid ammonia storage tank; 14. Ammonia flow controller; 15. Ammonia preheater; 16. Plasma-co-catalyzed ammonia decomposition reactor; 17. Spark plug; 18. Ammonia engine; 19. Ammonia decomposition catalyst; 20. Plasma discharge area; 21. High-voltage electrode terminal; 22. Ceramic insulating protective layer; 23. High-voltage electrode; 24. Grounding electrode. Detailed Implementation

[0022] The technical solution of the present invention will be further described and illustrated below through examples. All raw materials used in the examples are commercially available or prepared using conventional methods.

[0023] Example 1 like Figure 1 As shown, this embodiment of the invention provides an ammonia fuel reforming system suitable for ammonia fuel engines, including: a liquid ammonia supply device, an ammonia gas supply device, an ammonia gas preheating device, an ammonia decomposition device, a pressurization device, a mixed gas buffer and injection device, and a control system.

[0024] In some embodiments, the liquid ammonia supply device includes a liquid ammonia storage tank 13 and a pressure reducing valve 12. The outlet of the liquid ammonia storage tank 13 is connected to the inlet of the pressure reducing valve 12, and the outlet of the pressure reducing valve 12 is connected to the inlet of the ammonia supply device. The pressure reducing valve 12 is used to reduce the outlet pressure of the liquid ammonia storage tank 13 to the inlet pressure required by the ammonia pressure stabilizing tank 11. By precisely regulating the pressure through the pressure reducing valve 12, a stable pressure gas source is provided for the subsequent ammonia supply device, avoiding the impact of pressure fluctuations on the stability of the ammonia supply and ensuring the reliable operation of the initial stage of the system.

[0025] In some embodiments, the ammonia supply device includes an ammonia pressure stabilizing tank 11, a second temperature and pressure sensor 10, and an ammonia flow controller 14. The inlet of the ammonia pressure stabilizing tank 11 is connected to the outlet of the liquid ammonia supply device, and the outlet of the ammonia pressure stabilizing tank 11 is connected to the inlet of the ammonia preheating device. The ammonia flow controller 14 is installed on the pipeline between the ammonia pressure stabilizing tank 11 and the ammonia preheating device, and the second temperature and pressure sensor 10 is installed on the ammonia pressure stabilizing tank 11.

[0026] Specifically, the ammonia pressure stabilizing tank 11 stabilizes the pressure of gaseous ammonia. The second temperature and pressure sensor 10 is an integrated temperature and pressure sensor used to monitor the temperature and pressure inside the ammonia pressure stabilizing tank 11 to determine the temperature and pressure of the ammonia inside the tank 11, providing basic parameters for the control system. The ammonia flow controller 14 can precisely adjust the ammonia flow rate entering the ammonia preheater 15 according to the operating conditions, ensuring the stability of the subsequent preheating and decomposition processes and improving the system's adaptability.

[0027] In some embodiments, the ammonia preheating device includes an ammonia preheater 15, an ammonia engine exhaust pipe 9, and a temperature sensor 8. The inlet of the ammonia preheater 15 is connected to the outlet of the ammonia supply device, and the outlet of the ammonia preheater 15 is connected to the inlet of the ammonia decomposition device. The ammonia preheater 15 and the exhaust gas of the ammonia engine exhaust pipe 9 adopt a countercurrent heat exchange method. The temperature sensor 8 is installed on the ammonia engine exhaust pipe 9.

[0028] Specifically, temperature sensor 8 is used to monitor the exhaust gas temperature inside the ammonia engine exhaust pipe 9. A spark plug 17 is installed at the inlet of the ammonia engine 18, and an exhaust pipe is installed at the outlet. The exhaust gas in the exhaust pipe provides heat to the ammonia preheater 15. The ammonia preheater 15 adopts a counter-current heat exchange method, heating the ammonia gas through counter-current heat exchange, thus reducing the energy consumption of the ammonia preheater 15. Utilizing the waste heat of the engine exhaust gas to preheat the ammonia gas achieves energy recovery and reduces additional energy consumption; the counter-current heat exchange method improves heat exchange efficiency, enhances the ammonia preheating effect, provides a suitable initial temperature for subsequent ammonia decomposition, reduces the energy demand of the plasma reactor, and indirectly improves the ammonia decomposition efficiency; the temperature sensor monitors the exhaust gas temperature, providing a basis for controlling the preheating process.

[0029] In some embodiments, such as Figure 2As shown, the ammonia decomposition device includes a plasma-co-catalyzed ammonia decomposition reactor 16 and a high-voltage power supply 6. The plasma-co-catalyzed ammonia decomposition reactor 16 includes a segmented ammonia decomposition catalyst 19 and a plasma discharge region 20. The ammonia decomposition catalyst 19 is placed after the plasma discharge region 20. One segment is the ammonia decomposition catalyst 19, and the other segment is the plasma discharge region 20. Ammonia gas first enters the plasma discharge region 20 and then flows through the ammonia decomposition catalyst 19. This two-stage plasma catalytic reactor places the catalyst at the rear end of the plasma reactor discharge region. This coupled plasma-co-catalyzed reaction process can be divided into two parts: the plasma reaction and the catalyst surface reaction. The two-stage plasma catalytic reaction can better control the direction of the chemical reaction and reduce the generation of by-products. The catalyst can effectively utilize the heat generated by the plasma discharge while avoiding the impact of plasma discharge on the catalyst's lifespan. The synergistic effect of plasma and catalyst solves the problem of high activity temperature (>550°C) of non-precious metal-based catalysts, improving their low-temperature activity and making them suitable for engine applications.

[0030] Specifically, the high-voltage power supply 6 is electrically connected to the plasma discharge region 20 to provide discharge for the plasma discharge region 20, ensuring uniform discharge for the reaction process. The plasma-co-catalyzed ammonia decomposition reactor 16 employs corona discharge, which is more energy-efficient and reduces energy consumption compared to dielectric barrier discharge for ammonia decomposition to hydrogen production.

[0031] Furthermore, such as Figure 2 As shown, a high-voltage electrode 23 is provided inside the plasma discharge region 20, and a grounding electrode 24 is provided outside. The high-voltage electrode 23 is connected to the high-voltage power supply 6 through a high-voltage electrode terminal 21, and the high-voltage electrode terminal 21 is wrapped with a ceramic insulating protection 22. The reactor is provided with an ammonia inlet and an ammonia + hydrogen outlet. Ammonia enters the plasma discharge region 20 from the inlet, and after being subjected to plasma discharge and the action of the ammonia decomposition catalyst 19, the generated ammonia-hydrogen mixture flows out from the outlet.

[0032] Furthermore, the ammonia decomposition catalyst 19 includes at least one of iron-based catalysts, nickel-based catalysts, cobalt-based catalysts, and copper-based catalysts. Non-precious metal catalysts are less expensive than precious metal catalysts, which is beneficial for large-scale industrial applications.

[0033] In some embodiments, the pressurization device includes a pressurization pump 5, the inlet of which is connected to the outlet of the ammonia decomposition device, and the outlet of the pressurization pump 5 is connected to the inlet of the mixed gas buffer and the injection device.

[0034] Specifically, the booster pump 5 is used to pressurize the ammonia-hydrogen mixture to ensure that the mixture has sufficient pressure to enter the subsequent buffer and injection stages, and to ensure that it can be effectively injected into the engine intake manifold to meet the engine combustion pressure requirements for the mixture.

[0035] In some embodiments, the gas mixture buffer and injection device includes a gas rail 3 and a nozzle 2. The gas rail 3 is used to buffer the pressurized ammonia-hydrogen mixture. The inlet of the gas rail 3 is connected to the outlet of the pressurization device, and the outlet of the gas rail 3 is connected to the inlet of the nozzle 2. A first temperature and pressure sensor 4 is provided on the gas rail 3, and the nozzle 2 is provided on the intake pipe of the ammonia fuel engine.

[0036] Specifically, the air rail 3 buffer can stabilize the air-fuel mixture pressure, the first temperature and pressure sensor 4 monitors the air-fuel mixture status in real time, and provides the control system with the basis for regulation; the nozzle 2 accurately injects the air-fuel mixture into the intake pipe, and cooperates with the engine operating conditions to control the injection timing and pulse width to ensure that the air-fuel mixture is fully mixed with the air and improve combustion efficiency.

[0037] The control system includes an Electronic Control Unit (ECU), which is electrically connected to the ammonia supply device, ammonia decomposition device, pressurization device, and mixture buffer and injection device. The ECU is used to adjust the operating status of each device based on detected parameters. The ECU receives signals from the first temperature and pressure sensor 4, ammonia flow controller 14, temperature sensor 8, high-voltage power supply 6, pressurization pump 5, spark plug 17, and second temperature and pressure sensor 10. After processing the data, the computer outputs the data to control the gas volume flow rate through the ammonia flow controller 14, the output power of the high-voltage power supply 6, the pressurization pressure of the pressurization pump 5, the injection timing of the ammonia-hydrogen mixture nozzle 2, and the ignition timing of the spark plug 17 in the ammonia engine 18. The control system adjusts the ammonia supply, ammonia decomposition device operating parameters, pressurization pressure, and mixture injection and ignition timing in real time based on the detected parameters, ensuring the coordinated and efficient operation of each device and guaranteeing the overall stability and reliability of the system.

[0038] Example 2 A control method for an ammonia fuel reforming system suitable for an ammonia fuel engine, the method being based on the ammonia fuel reforming system of the ammonia fuel engine described in Example 1. The control method includes: Initially, all modules of the system are in a stopped state.

[0039] System operation phase: The pressure reducing valve 12 is opened, and fuel is introduced from the liquid ammonia storage tank 13 into the ammonia pressure stabilizing tank 11. The pressure reducing valve 12 controls the gas pressure entering the ammonia pressure stabilizing tank 11 to be 3-10 bar. After the second temperature and pressure sensor 10 detects that the gas state inside the ammonia pressure stabilizing tank 11 is stable, the ammonia flow controller 14 is opened to control the ammonia flow rate according to different operating conditions. After the ammonia enters the ammonia preheater 15, the temperature sensor 8 detects the tail gas temperature of the ammonia preheater 15. Based on the ammonia flow rate and tail gas temperature, the output power of the high-voltage power supply 6 is controlled to meet the ammonia-hydrogen mixing requirements after the ammonia reacts in the plasma-co-catalyzed ammonia decomposition reactor 16. The hydrogen component in the gas is 5%-15%. The reacted ammonia-hydrogen mixture is fed into a pressurizing pump 5, which pressurizes the mixture before it enters the ammonia-hydrogen mixture gas rail 3 for buffering. A first temperature and pressure sensor 4 is used to detect the temperature and pressure of the buffer gas in the ammonia-hydrogen mixture gas rail 3. The buffer gas flows from the ammonia-hydrogen mixture gas rail 3 through a pipeline to the ammonia-hydrogen mixture nozzle 2, which injects the ammonia-hydrogen mixture into the ammonia engine intake manifold 1. The injection timing and injection pulse width are controlled by a calibrated operating condition pulse spectrum. After the mixture is injected into the ammonia engine intake manifold 1, it enters cylinder 18 of the ammonia engine, where it is ignited by spark plug 17. The ignition energy and ignition timing are controlled by the calibrated operating condition pulse spectrum. After the system operation is completed, all modules of the system are shut down.

[0040] Standardized processes ensure orderly system startup and operation, and precise control of hydrogen gas fraction (5%-15%), which solves the problem of slow ammonia combustion and avoids the safety risks caused by excessive hydrogen. The injection and ignition parameters are controlled by operating condition pulse spectrum to match engine requirements and improve combustion efficiency. Fully automated control reduces human intervention, ensures stable system operation, and ultimately achieves zero carbon emissions.

[0041] It should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. An ammonia fuel reforming system suitable for ammonia fuel engines, characterized in that, include: A liquid ammonia supply unit is used to supply liquid ammonia and vaporize and regulate its pressure; An ammonia supply device, connected to the outlet of the liquid ammonia supply device, is used to stably supply gaseous ammonia and detect its state parameters; An ammonia preheating device is connected to the outlet of the ammonia supply device and is used to preheat ammonia using the waste heat from the exhaust gas of the ammonia fuel engine. An ammonia decomposition device is connected to the outlet of the ammonia preheating device and is used to decompose ammonia to generate an ammonia-hydrogen mixture. A pressurizing device, connected to the outlet of the ammonia decomposition device, is used to pressurize the ammonia-hydrogen mixture. A mixture buffer and injection device is connected to the outlet of the pressurization device and is used to buffer the pressurized ammonia-hydrogen mixture and inject it into the intake pipe of the ammonia fuel engine. The control system is electrically connected to the ammonia supply device, ammonia decomposition device, pressurization device, mixed gas buffer and injection device, respectively, and is used to adjust the operating status of each device according to the detection parameters.

2. The ammonia fuel reforming system for ammonia fuel engines according to claim 1, characterized in that, The ammonia decomposition device includes a plasma-co-catalyzed ammonia decomposition reactor (16) and a high-voltage power supply (6). The plasma-co-catalyzed ammonia decomposition reactor (16) includes a segmented ammonia decomposition catalyst (19) and a plasma discharge region (20). The ammonia decomposition catalyst (19) is placed after the plasma discharge region (20). The high-voltage power supply (6) is electrically connected to the plasma discharge region (20) and is used to provide discharge to the plasma discharge region (20).

3. The ammonia fuel reforming system for ammonia fuel engines according to claim 2, characterized in that, The plasma-co-catalyzed ammonia decomposition reactor (16) adopts a corona discharge method.

4. The ammonia fuel reforming system for ammonia fuel engines according to claim 2, characterized in that, The ammonia decomposition catalyst (19) includes at least one of iron-based catalysts, nickel-based catalysts, cobalt-based catalysts, and copper-based catalysts.

5. The ammonia fuel reforming system for ammonia fuel engines according to claim 1, characterized in that, The liquid ammonia supply device includes a liquid ammonia storage tank (13) and a pressure reducing valve (12). The outlet of the liquid ammonia storage tank (13) is connected to the inlet of the pressure reducing valve (12), and the outlet of the pressure reducing valve (12) is connected to the inlet of the ammonia supply device. The pressure reducing valve (12) is used to reduce the outlet pressure of the liquid ammonia storage tank (13) to the inlet pressure required by the ammonia pressure stabilizing tank (11).

6. The ammonia fuel reforming system for ammonia fuel engines according to claim 1, characterized in that, The ammonia supply device includes an ammonia pressure stabilizing tank (11), a second temperature and pressure sensor (10), and an ammonia flow controller (14). The inlet of the ammonia pressure stabilizing tank (11) is connected to the outlet of the liquid ammonia supply device, and the outlet of the ammonia pressure stabilizing tank (11) is connected to the inlet of the ammonia preheating device. The ammonia flow controller (14) is installed on the pipeline between the ammonia pressure stabilizing tank (11) and the ammonia preheating device. The second temperature and pressure sensor (10) is installed on the ammonia pressure stabilizing tank (11).

7. The ammonia fuel reforming system for ammonia fuel engines according to claim 1, characterized in that, The ammonia preheating device includes an ammonia preheater (15), an ammonia engine exhaust pipe (9), and a temperature sensor (8). The inlet of the ammonia preheater (15) is connected to the outlet of the ammonia supply device, and the outlet of the ammonia preheater (15) is connected to the inlet of the ammonia decomposition device. The ammonia preheater (15) and the exhaust gas of the ammonia engine exhaust pipe (9) are exchanged in a countercurrent manner. The temperature sensor (8) is installed on the ammonia engine exhaust pipe (9).

8. The ammonia fuel reforming system for ammonia fuel engines according to claim 1, characterized in that, The pressurizing device includes a pressurizing pump (5), the inlet of which is connected to the outlet of the ammonia decomposition device, and the outlet of which is connected to the inlet of the mixed gas buffer and injection device.

9. The ammonia fuel reforming system for ammonia fuel engines according to claim 1, characterized in that, The gas mixture buffer and injection device includes a gas rail (3) and a nozzle (2). The gas rail (3) is used to buffer the pressurized ammonia-hydrogen mixture. The inlet of the gas rail (3) is connected to the outlet of the pressurization device, and the outlet of the gas rail (3) is connected to the inlet of the nozzle (2). A first temperature and pressure sensor (4) is provided on the gas rail (3), and the nozzle (2) is provided on the ammonia engine intake pipe (1).

10. The control method for an ammonia fuel reforming system suitable for an ammonia fuel engine according to any one of claims 1-9, characterized in that, The control method includes: S1. Liquid ammonia is supplied through a liquid ammonia supply device and vaporized and pressure regulated, and gaseous ammonia is stably output through an ammonia supply device. S2. Using an ammonia preheating device, the waste heat from the exhaust gas of an ammonia fuel engine is used to preheat the gaseous ammonia. S3. Introduce the preheated ammonia gas into the ammonia decomposition device to decompose the ammonia and generate an ammonia-hydrogen mixture with a hydrogen gas fraction of 5%-15%. S4. After the ammonia-hydrogen mixture is pressurized by the pressurizing device, it is buffered by the mixture buffer and injection device and injected into the intake pipe of the ammonia fuel engine. S5. The control system adjusts the ammonia supply, the operating parameters of the ammonia decomposition unit, the pressurization pressure, the injection timing of the mixture, and the engine ignition timing based on the detected status parameters.

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