A pre-chamber system and control method based on high-pressure dual direct injection of ammonia and hydrogen

Abstract

The present invention discloses a pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen, which includes a pre-chamber subsystem, an ammonia reforming hydrogen production subsystem, and a pre-chamber electronic control subsystem; the pre-chamber subsystem includes a pre-chamber and a high-pressure dual direct injection injector disposed therein, and the space between the outer sleeve of the pre-chamber and the inner sleeve of the pre-chamber is an outer wall cooling water cooling channel. The high-pressure dual direct injection injector includes a reformed gas pipeline and a liquid ammonia pipeline that are disposed in the injector body and are independent of each other to achieve the injection of dual fuels in the pre-chamber; the temperature of the pre-chamber is controlled by means of external water cooling of the pre-chamber and endothermic vaporization of liquid ammonia inside the pre-chamber, thereby solving the problem of ablation of the injector in the pre-chamber. The injection strategy can be flexibly changed through the pre-chamber electronic control subsystem; the ammonia reforming hydrogen production subsystem is used to provide reformed gas for the pre-chamber online, which not only simplifies the fuel supply system, but also has a higher safety factor, and solves the problem of difficult ignition during the cold start stage of the ammonia engine.

Description

Technical Field

[0001] The present invention belongs to the combustion system of internal combustion engines, and particularly relates to a pre-chamber system and a control method based on high-pressure dual direct injection of ammonia and hydrogen. Background Art

[0002] Internal combustion engines are the most widely used leading power equipment in the national economy and national defense construction, consuming more than 60% of the world's petroleum and releasing 25% of the global carbon emissions. They are one of the main sources of air pollution. To save energy and reduce carbon emissions, zero-carbon fuels, green ammonia and green hydrogen, have gradually attracted the attention of the academic and industrial communities. Compared with hydrogen, ammonia has the advantages of high volumetric energy density, high hydrogen storage density, and convenient storage and transportation. However, ammonia has problems such as difficult ignition and slow flame propagation speed. The combustion characteristics of ammonia are improved by using the jet flame of a hydrogen pre-chamber to ignite ammonia. The pre-chamber is mostly cooled by air cooling, and the cooling effect is poor. Coupled with the high combustion temperature of hydrogen, the hydrogen injector in the pre-chamber is prone to ablation. In addition, to supply hydrogen fuel to the pre-chamber, an additional hydrogen storage tank needs to be carried, making the fuel supply system more complex and the risk factor higher. Summary of the Invention

[0003] In view of the above-mentioned prior art, the present invention provides a pre-chamber system and a control method based on high-pressure dual direct injection of ammonia and hydrogen, which can solve the problem of ablation of the injector in the pre-chamber and use an ammonia on-line reforming hydrogen production system to meet the hydrogen fuel demand of the pre-chamber. In the present invention, the temperature of the pre-chamber is controlled by external water cooling of the pre-chamber and endothermic vaporization of liquid ammonia inside the pre-chamber, thereby solving the problem of ablation of the injector in the pre-chamber. Another object of the present invention is to use an ammonia reforming hydrogen production subsystem to provide reformed gas for the pre-chamber on-line, simplify the fuel supply system, and solve the problem of difficult ignition during the cold start stage of an ammonia engine.

[0004] To solve the above technical problems, a pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen proposed by the present invention includes a pre-chamber subsystem, an ammonia reforming hydrogen production subsystem, and a pre-chamber electronic control subsystem;

[0005] The pre - combustion chamber subsystem includes a pre - combustion chamber. The chamber wall of the pre - combustion chamber includes a pre - combustion chamber outer sleeve and a pre - combustion chamber inner sleeve. Inside the pre - combustion chamber, there are a high - pressure dual - direct - injection injector, a spark plug, and a temperature sensor. There are ten cooling water channels arranged circumferentially in the space between the pre - combustion chamber outer sleeve and the pre - combustion chamber inner sleeve. Adjacent five cooling water channels in the circumferential direction are connected in series, dividing the ten cooling water channels into two groups. The positions of the series connection ports of adjacent cooling water channels in the same group are arranged staggeredly at upper and lower intervals. All the cooling water channels share a cooling water inlet and a cooling water outlet, both of which are located at the top of the pre - combustion chamber. The cooling water inlet and the cooling water outlet are connected to the engine cooling system, and a cooling water electric flow regulating valve is provided on the water inlet pipe. The high - pressure dual - direct - injection injector is located at the central position of the pre - combustion chamber. The high - pressure dual - direct - injection injector includes a reformed gas pipeline and an ammonia pipeline that are arranged in the injector body and are independent of each other. The spark plug is laterally installed in the pre - combustion chamber, and the temperature sensor is vertically installed in the pre - combustion chamber.

[0006] The ammonia reforming hydrogen production subsystem includes an ammonia tank, a reformed gas storage tank, and a reformer. An exhaust temperature sensor is installed on the engine exhaust pipe, and the reformer is installed on the outer wall of the engine exhaust pipe. The ammonia tank is connected to the inlet of the reformer through pipeline A, and a reformer electric flow regulating valve is provided on pipeline A. One - way valves are installed at both the inlet and the outlet of the reformer. The outlet of the reformer is connected to the inlet of the reformed gas storage tank through an outlet pipe, and the outlet of the reformed gas storage tank is connected to the inlet of the reformed gas pipeline of the high - pressure dual - direct - injection injector. A reformed gas composition and content sensor is installed in the reformed gas storage tank. The ammonia in the ammonia tank flows into the reformer after the flow rate is adjusted by the reformer electric flow regulating valve.

[0007] The pre - combustion chamber electronic control subsystem includes an ECU unit and an intake - passage ammonia injector connected to the ammonia tank. The nozzle of the intake - passage ammonia injector extends into the engine intake passage. The cooling water electric flow regulating valve, the high - pressure dual - direct - injection injector, the spark plug, the temperature sensor installed in the pre - combustion chamber, the exhaust temperature sensor, the reformed gas composition and content sensor, and the reformer electric flow regulating valve are all connected to the ECU unit.

[0008] Furthermore, in the pre - combustion chamber system based on ammonia - hydrogen high - pressure dual - direct - injection of the present invention, among them: Five cooling water channels in the same group of cooling water channels are connected in series by a cooling water channel connecting cavity.

[0009] Cooling water from the engine flows into the cooling water channels of the pre - combustion chamber after the flow rate is controlled by the cooling water electric flow regulating valve, absorbs the heat of the pre - combustion chamber, and then flows back to the engine.

[0010] The reformer is equipped with a catalyst, and the reformer utilizes high-temperature tail gas and the catalyst to convert ammonia into hydrogen and nitrogen online, which flows into the reformed gas storage tank through a one-way valve and is then sprayed into the pre-combustion chamber by the high-pressure dual direct injection injector to ignite the ammonia.

[0011] The high-pressure dual direct injection injector injects liquid ammonia and ammonia reforming gas into the pre-combustion chamber, wherein the liquid ammonia vaporizes and absorbs heat in the pre-combustion chamber, and supplies fuel to the pre-combustion chamber while reducing the temperature of the pre-combustion chamber, and the ammonia reforming gas is used to ignite the ammonia.

[0012] At the same time, the present invention also proposes a control method for the above-mentioned precombustion chamber system, and the control implemented by the ECU unit includes: adjusting the injection strategy of the intake duct ammonia injector according to the throttle opening; adjusting the opening of the cooling water electric flow control valve and the injection amount of liquid ammonia sprayed into the precombustion chamber by the high-pressure dual direct injection injector according to the precombustion chamber temperature detected by the temperature sensor; adjusting the reforming gas injection strategy according to the injection amount of liquid ammonia in the precombustion chamber, and then controlling the spark plug ignition; calculating the target reforming gas volume according to the exhaust temperature detected by the exhaust temperature sensor and the reforming gas composition and content in the gas storage tank detected by the reforming gas composition and content sensor and the corresponding content, and then adjusting the opening of the reformer electric flow control valve to control the ammonia flow flowing into the reformer.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The outer wall of the precombustion chamber of the present invention is cooled by cooling water, and the inner wall of the precombustion chamber is cooled by liquid ammonia. The double cooling effect is better and the problem of injector ablation in the precombustion chamber is solved.

[0015] (2) The present invention is the first to install a high-pressure dual direct injection injector in the pre-combustion chamber. The two independent fuel delivery pipelines in the injector innovatively realize the injection of dual fuels in the pre-combustion chamber, and the injection strategy is flexible and changeable.

[0016] (3) The present invention adopts an ammonia online reforming hydrogen production device to simplify the fuel supply system, has a higher safety factor, and solves the problem of difficulty in ignition during the cold start phase of the ammonia engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the pre-combustion chamber system based on ammonia-hydrogen high-pressure dual direct injection of the present invention;

[0018] Figure 2 yes Figure 1 The structural schematic diagram of the pre-combustion chamber subsystem is shown in;

[0019] Figure 3 yes Figure 2 AA section schematic diagram of the pre-combustion chamber subsystem shown in;

[0020] Figure 4 is Figure 1 the schematic diagram of the internal pipeline of the high-pressure dual direct injection injector shown in

[0021] Figure 5 is the control flow chart of the pre-chamber electronic control subsystem of the present invention.

[0022] In the figure:

[0023] 1 - Engine 2 - Pre-chamber subsystem 3 - Ammonia reforming hydrogen production subsystem

[0024] 4 - First one-way valve 5 - Outer sleeve of the pre-chamber 6 - Inner sleeve of the pre-chamber

[0025] 7 - Cooling water inlet 8 - Cooling water outlet 9 - High-pressure dual direct injection injector

[0026] 10 - Spark plug 11 - Temperature sensor 12 - Electric flow regulating valve for cooling water

[0027] 13 - Cooling water channel 14 - Cooling water channel connecting cavity 15 - Exhaust gas temperature sensor

[0028] 16 - Electric flow regulating valve for reformer 17 - Second one-way valve 18 - Reformed gas composition and content sensor

[0029] 19 - Reformed gas storage tank 20 - Reformer 21 - Inlet duct ammonia injector

[0030] 22 - ECU unit 23 - Ammonia tank 901 - Injector body

[0031] 902 - Reformed gas pipeline 903 - Liquid ammonia pipeline Specific embodiments

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means any limitation to the present invention.

[0033] A pre-chamber system based on ammonia-hydrogen high-pressure dual direct injection proposed by the present invention mainly includes a pre-chamber subsystem 2, an ammonia reforming hydrogen production subsystem 3, and a pre-chamber electronic control subsystem. Figure 1 shows the overall structural schematic diagram of the pre-chamber system based on ammonia-hydrogen high-pressure dual direct injection of the present invention; Figure 2 shows the structural schematic diagram of the pre-chamber subsystem therein; Figure 3 shows Figure 2 the A-A sectional schematic diagram of the pre-chamber subsystem in

[0034] As Figures 1 to 3As shown, the pre-combustion chamber subsystem 2 includes a pre-combustion chamber, the chamber wall of the pre-combustion chamber includes a pre-combustion outer sleeve 5 and a pre-combustion inner sleeve 6, the pre-combustion chamber is provided with a high-pressure dual direct injection injector 9, a spark plug 10 and a temperature sensor 11, and ten cooling water channels 13 are circumferentially arranged in the space between the pre-combustion outer sleeve 5 and the pre-combustion inner sleeve 6. The ten cooling water channels 13 are divided into two groups according to the five cooling water channels 13 adjacent to each other in the circumferential direction. The positions of the series ports of adjacent cooling water channels 13 in the same group are arranged alternately according to the upper and lower intervals. The five cooling water channels 13 in the same group of cooling water channels can be The cooling water channel connecting cavity 14 is connected in series, that is, each group of five cooling water channels 13 is axially evenly arranged in an N-shaped manner on the outer wall of the precombustion chamber and connected to each other. The cooling water channel connecting cavity 14 connects two adjacent cooling water channels 13, and two groups (that is, all) of cooling water channels share a cooling water inlet 7 and a cooling water outlet 8. The cooling water inlet 7 and the cooling water outlet 8 are both located at the top of the precombustion chamber. The cooling water inlet 7 and the cooling water outlet 8 are connected to the engine cooling system, and a cooling water electric flow regulating valve 12 is provided on the water inlet pipe to control the cooling water flow. The cooling water from the engine flows into the cooling water channel 13 of the precombustion chamber after the flow is controlled by the cooling water electric flow regulating valve 12, and flows back to the engine after absorbing the heat of the precombustion chamber. The high-pressure dual direct injection injector 9 is located at the center of the precombustion chamber. Figure 4 The internal piping structure of the high-pressure dual direct injection injector in the present invention is shown. The high-pressure dual direct injection injector 9 includes a reforming gas pipeline 902 and a liquid ammonia pipeline 903 which are arranged in the injector body 901 and are independent of each other. The spark plug 10 is installed laterally in the pre-combustion chamber. The temperature sensor 11 is installed vertically in the pre-combustion chamber. The spark plug 10 and the pre-combustion chamber temperature sensor 11 are respectively located on both sides of the high-pressure dual direct injection injector 9. The reforming gas is transported to the pre-combustion chamber through the reforming gas pipeline 902 of the high-pressure dual direct injection injector, and the liquid ammonia is transported to the pre-combustion chamber through the liquid ammonia pipeline 903 of the high-pressure dual direct injection injector. Figure 1 As shown. Since the high-pressure dual direct injection injector 9 has two independent fuel delivery pipelines inside, the fuels do not interfere with or blend with each other. The high-pressure dual direct injection injector 9 independently injects liquid ammonia and ammonia reforming gas into the pre-combustion chamber. The liquid ammonia vaporizes and absorbs heat in the pre-combustion chamber, which reduces the temperature of the pre-combustion chamber while also supplying fuel to the pre-combustion chamber, while the ammonia reforming gas is responsible for igniting ammonia. The spark plug is installed sideways in the pre-combustion chamber, responsible for igniting the mixture in the pre-combustion chamber. The temperature sensor is installed vertically in the pre-combustion chamber, responsible for detecting the temperature of the pre-combustion chamber.

[0035] like Figure 1As shown, the ammonia reforming hydrogen production subsystem 3 includes an ammonia tank 23, a reformed gas storage tank 19, and a reformer 20. An exhaust gas temperature sensor 15 is installed on the engine exhaust pipe to detect the exhaust gas temperature. The reformer 20 is installed on the outer wall of the engine exhaust pipe and contains a catalyst inside. The high-temperature exhaust gas and the catalyst are used to catalytically convert ammonia into hydrogen and nitrogen online. The ammonia tank 23 is connected to the inlet of the reformer 20 through pipeline A, and a reformer electric flow regulating valve 16 is provided on pipeline A to control the ammonia flow into the reformer 20. One-way valves are installed at both the inlet and outlet of the reformer 20 to ensure that the gas in the reformer 20 flows unidirectionally into the reformed gas storage tank 19. The reformed gas storage tank 19 is located between the reformer 20 and the high-pressure dual direct injection injector 9, and functions to stabilize the pressure and store the reformed gas. The outlet of the reformer 20 is connected to the inlet of the reformed gas storage tank 19 through an outlet pipe, and the outlet of the reformed gas storage tank 19 is connected to the inlet of the reformed gas pipeline 902 of the high-pressure dual direct injection injector 9. A reformed gas composition and content sensor 18 is installed in the reformed gas storage tank 19 to detect the reformed gas composition and the corresponding content. The ammonia in the ammonia tank 23 flows into the reformer 20 after the flow is adjusted by the reformer electric flow regulating valve 16. The reformer 20 contains a catalyst, and the high-temperature exhaust gas is used to realize online reforming of ammonia to produce hydrogen. The reformer 20 uses the high-temperature exhaust gas and the catalyst to catalytically crack ammonia in the reformer 20 and decompose it into hydrogen and nitrogen, which then flow into the reformed gas storage tank 19 through a one-way valve and then into the reformed gas storage tank 19, and are then injected into the pre-chamber by the high-pressure dual direct injection injector 9 to ignite the ammonia. Specifically, the high-pressure dual direct injection injector 9 injects liquid ammonia and reformed ammonia gas into the pre-chamber. Among them, the liquid ammonia vaporizes and absorbs heat in the pre-chamber, reducing the temperature of the pre-chamber while also supplying fuel to the pre-chamber, and the reformed ammonia gas is used to ignite the ammonia.

[0036] As Figure 1 shown, the pre-chamber electronic control subsystem includes an ECU unit and an intake port ammonia injector 21 connected to the ammonia tank 23. The nozzle of the intake port ammonia injector 21 extends into the engine intake port. The cooling water electric flow regulating valve 12, the high-pressure dual direct injection injector 9, the spark plug 10, the temperature sensor 11 installed in the pre-chamber, the exhaust gas temperature sensor 15, the reformed gas composition and content sensor 18, and the reformer electric flow regulating valve 16 are all connected to the ECU unit.

[0037] The ECU unit includes 4 functional modules, namely ECU module 1, ECU module 2, ECU module 3, and ECU module 4, which are used to achieve the following controls:

[0038] ECU module 1 adjusts the injection strategy of the intake port ammonia injector 21 according to the throttle opening to supply ammonia fuel to the main combustion chamber.

[0039] The ECU module 2 adjusts the opening degree of the cooling water electric flow regulating valve 12 and the injection amount of liquid ammonia injected into the pre-combustion chamber by the high-pressure dual direct injection injector 9 according to the pre-combustion chamber temperature detected by the temperature sensor 11.

[0040] The ECU module 3 adjusts the opening degree of the reformer electric flow regulating valve 16 and controls the ammonia flow rate into the reformer 20 according to the exhaust gas temperature detected by the exhaust gas temperature sensor 15 and the reformed gas composition and content in the gas storage tank detected by the reformed gas composition and content sensor 18, and the ECU unit 22 calculates the required amount of reformed gas for stable ignition of the pre-combustion chamber based on the injection amount of liquid ammonia injected into the pre-combustion chamber by the high-pressure dual direct injection injector 9.

[0041] The ECU module 4 adjusts the reformed gas injection strategy of the high-pressure dual direct injection injector 9 according to the injection amount of liquid ammonia injected into the pre-combustion chamber by the high-pressure dual direct injection injector 9, and then controls the spark plug 10 to ignite.

[0042] As Figure 1 and Figure 5 shown. The specific operation process of the present invention is as follows:

[0043] Step 1, according to the throttle opening, the ECU unit adjusts the injection strategy of the intake port ammonia injector 9 to supply ammonia fuel to the main combustion chamber of the engine 1.

[0044] Step 2, the temperature sensor 11 in the pre-combustion chamber detects the pre-combustion chamber temperature and transmits the pre-combustion chamber temperature to the ECU unit; the ECU unit adjusts the opening degree of the pre-combustion chamber cooling water electric flow regulating valve 12 and the liquid ammonia injection amount of the high-pressure dual direct injection injector 9 according to this temperature to ensure that the pre-combustion chamber temperature is maintained within a safe range.

[0045] Step 3, the ECU unit calculates the required amount of reformed gas for stable ignition of the pre-combustion chamber based on the liquid ammonia injection amount in the pre-combustion chamber; the reformed gas composition and content sensor 18 transmits the gas composition and content information in the reformed gas storage tank 19 to the ECU unit, and at the same time, the exhaust gas temperature sensor 15 transmits the exhaust gas temperature to the ECU unit. The ECU unit adjusts the opening degree of the reformer electric flow regulating valve 16 according to the target reformed gas amount to control the ammonia flow rate into the reformer 20 to ensure that the gas amount in the reformed gas storage tank 19 is sufficient and to provide additional reformed gas required during the cold start phase.

[0046] Step 4, the ECU unit controls the high-pressure dual direct injection injector 9 to inject reformed gas after injecting liquid ammonia, and controls the spark plug 10 to ignite at the optimal ignition moment to ensure stable ignition of the mixture in the pre-combustion chamber; then the jet flame sprays into the main combustion chamber through the pre-combustion chamber spray holes to ignite the combustible mixture in the main combustion chamber; thus, a complete working process has been completed, and then the above working process is repeated in this order.

[0047] In summary, the present invention is a pre-chamber system and control method based on ammonia-hydrogen high-pressure dual direct injection, which utilizes the characteristics of liquid ammonia vaporization endotherm to cool the inner wall of the pre-chamber and adopts a water-cooling method to cool the outer wall of the pre-chamber, solving the problem of pre-chamber injector ablation. At the same time, the ammonia on-line reforming hydrogen production device can simplify the fuel supply system and improve the safety factor, meeting the demand of the pre-chamber for hydrogen fuel.

[0048] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many variations without departing from the purpose of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen, comprising a pre-chamber subsystem (2), an ammonia reforming hydrogen production subsystem (3), and a pre-chamber electronic control subsystem; The pre-chamber subsystem (2) includes a pre-chamber. The chamber wall of the pre-chamber includes a pre-chamber outer sleeve (5) and a pre-chamber inner sleeve (6). Inside the pre-chamber, there are a high-pressure dual direct injection injector (9), a spark plug (10), and a temperature sensor (11). In the space between the pre-chamber outer sleeve (5) and the pre-chamber inner sleeve (6), ten cooling water channels (13) are arranged circumferentially. Adjacent five cooling water channels (13) in the circumferential direction are connected in series, dividing the ten cooling water channels (13) into two groups. The positions of the series connection ports of adjacent cooling water channels (13) in the same group are arranged staggeredly at upper and lower intervals. All the cooling water channels share a cooling water inlet (7) and a cooling water outlet (8). Both the cooling water inlet (7) and the cooling water outlet (8) are located at the top of the pre-chamber. The cooling water inlet (7) and the cooling water outlet (8) are connected to the engine cooling system, and a cooling water electric flow regulating valve (12) is provided on the inlet pipe; The high-pressure dual direct injection injector (9) is located at the central position of the pre-chamber. The high-pressure dual direct injection injector (9) includes a reformed gas pipeline (902) and a liquid ammonia pipeline (903) that are arranged inside the injector body (901) and are independent of each other. The spark plug (10) is laterally installed inside the pre-chamber, and the temperature sensor (11) is vertically installed inside the pre-chamber; The ammonia reforming hydrogen production subsystem (3) includes an ammonia tank (23), a reformed gas storage tank (19), and a reformer (20). An exhaust gas temperature sensor (15) is installed on the engine exhaust pipe, and the reformer (20) is installed on the outer wall of the engine exhaust pipe; the ammonia tank (23) is connected to the inlet of the reformer (20) through pipeline A, and a reformer electric flow regulating valve (16) is provided on pipeline A; one-way valves are installed at both the inlet and the outlet of the reformer (20). The outlet of the reformer (20) is connected to the inlet of the reformed gas storage tank (19) through an outlet pipe, and the outlet of the reformed gas storage tank (19) is connected to the inlet of the reformed gas pipeline (902) of the high-pressure dual direct injection injector (9); a reformed gas composition and content sensor (18) is installed in the reformed gas storage tank (10). The ammonia in the ammonia tank (23) flows into the reformer (20) after the flow rate is adjusted by the reformer electric flow regulating valve (16); The pre-chamber electronic control subsystem includes an ECU unit and an intake port ammonia injector (21) connected to the ammonia tank (23). The nozzle of the intake port ammonia injector (21) extends into the engine intake port. The cooling water electric flow regulating valve (12), the high-pressure dual direct injection injector (9), the spark plug (10), the temperature sensor (11) installed inside the pre-chamber, the exhaust gas temperature sensor (15), the reformed gas composition and content sensor (18), and the reformer electric flow regulating valve (16) are all connected to the ECU unit.

2. The pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen according to claim 1, characterized in that, five cooling water channels (13) in the same group of cooling water channels are connected in series by a cooling water channel connecting cavity (14).

3. The pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen according to claim 1, characterized in that, The cooling water from the engine flows into the cooling water channel (13) of the pre-chamber after the flow rate is controlled by the cooling water electric flow regulating valve (12), absorbs the heat of the pre-chamber and then flows back to the engine.

4. The pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen according to claim 1, characterized in that, The reformer (20) is filled with a catalyst. The reformer (20) catalytically converts ammonia into hydrogen and nitrogen online by using high-temperature exhaust gas and the catalyst, and flows into the reformed gas storage tank (19) through a one-way valve, and then is sprayed into the pre-chamber by the high-pressure dual direct injection injector (9) to ignite ammonia.

5. The pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen according to claim 1, characterized in that, The high-pressure dual direct injection injector (9) injects liquid ammonia and ammonia reformed gas into the pre-chamber. Among them, the liquid ammonia vaporizes and absorbs heat in the pre-chamber, while reducing the temperature of the pre-chamber, it also supplies fuel for the pre-chamber, and the ammonia reformed gas is used to ignite ammonia.

6. A control method for a pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen, characterized in that, adopt the pre-chamber system as described in any one of claims 1-5, The ECU unit adjusts the injection strategy of the intake air ammonia injector (21) according to the throttle opening; The ECU unit adjusts the opening of the cooling water electric flow regulating valve (12) and the injection amount of the liquid ammonia injected into the pre-chamber by the high-pressure dual direct injection injector (9) according to the pre-chamber temperature detected by the temperature sensor (11); The ECU unit calculates the target reformed gas volume according to the exhaust gas temperature detected by the exhaust gas temperature sensor (15) and the reformed gas composition and content detected by the reformed gas composition and content sensor in the storage tank, and then adjusts the opening of the reformer electric flow regulating valve (16) to control the ammonia flow rate flowing into the reformer (20); The ECU unit adjusts the reformed gas injection strategy according to the liquid ammonia injection amount in the pre-chamber, and then controls the spark plug to ignite.

7. The control method for a pre-chamber system based on high-pressure dual direct injection of ammonia and hydrogen according to claim 6, characterized in that, includes the following steps: Step 1, according to the throttle opening, the ECU unit adjusts the injection strategy of the intake air ammonia injector to supply ammonia fuel to the main combustion chamber of the engine; Step 2, the pre-chamber temperature sensor detects the pre-chamber temperature and transmits the pre-chamber temperature to the ECU unit; the ECU unit adjusts the opening of the pre-chamber cooling water electric flow regulating valve and the liquid ammonia injection amount of the high-pressure dual direct injection injector according to this temperature to ensure that the pre-chamber temperature is maintained within a safe range; Step 3: The ECU unit calculates the amount of reformed gas required for stable ignition in the pre-chamber based on the amount of liquid ammonia injected into the pre-chamber. The reformed gas composition and content sensor transmits the gas composition and content information in the reformed gas storage tank to the ECU unit. At the same time, the exhaust gas temperature sensor transmits the exhaust gas temperature to the ECU unit. The ECU unit adjusts the opening degree of the reformer electric flow control valve (16) according to the target amount of reformed gas to control the ammonia flow rate into the reformer, ensuring sufficient gas volume in the reformed gas storage tank and additionally providing the reformed gas required during the cold start phase. Step 4: The ECU unit controls the high-pressure double direct injection injector to inject reformed gas after injecting liquid ammonia, and controls the spark plug to ignite at the optimal ignition moment to ensure stable ignition of the mixture in the pre-chamber. Subsequently, the jet flame is sprayed into the main combustion chamber through the pre-chamber spray holes to ignite the combustible mixture in the main combustion chamber. At this point, a complete working process has been completed, and then the above working process is repeated in this order.

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