Ammonia supply system of ammonia engine and control method of ammonia supply system

Abstract

The invention relates to an ammonia supply system of an ammonia engine and a control method of the ammonia supply system. A supercharging circuit assembly; the pressurization loop assembly comprises a pressurization path water bath heater communicated with the liquid ammonia tank through a first pipeline, a first ammonia gas filter communicated with the pressurization path water bath heater through a second pipeline, and a third pipeline of which one end is communicated with the first ammonia gas filter and the other end is communicated with the liquid ammonia tank; the first electromagnetic valve is arranged on the first pipeline; the ammonia gas booster pump is arranged on the third pipeline; the check valve is arranged on the third pipeline and is positioned at the downstream of the ammonia gas booster pump; and an injection circuit assembly. Through cooperation of the structures such as the pressurization loop assembly and the injection loop assembly, the design of the ammonia supply system from liquid storage to gas injection can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile engines, and in particular to an ammonia supply system for an ammonia engine and a control method thereof. Background Art

[0002] Due to its zero-carbon nature, ammonia emits no CO₂ after combustion, meeting the "dual carbon" goals. It requires only 0.6-1 MPa to liquefy at room temperature, with a volumetric energy density 1.5 times that of liquid hydrogen. Furthermore, a mature global ammonia storage and transportation infrastructure already exists. Consequently, research on ammonia (NH₃) as an internal combustion engine fuel has garnered widespread attention in recent years, becoming a key alternative to traditional fossil fuels. Furthermore, "green ammonia" can be synthesized from renewable hydrogen, or "blue ammonia" can be produced in conjunction with carbon capture technology to meet various environmental requirements. Ammonia has a higher octane number and better anti-knock properties than traditional fuels, enabling high-compression-ratio combustion and achieving a theoretical thermal efficiency approaching that of diesel engines.

[0003] However, ammonia typically cannot be burned independently within the engine cylinder and must be blended with other fuels (such as diesel, hydrogen, and dimethyl ether). Ammonia can contribute over 90% of the energy. One of the challenges in implementing ammonia engines in vehicles, ships, or stationary power generation applications lies in the design and control of the ammonia supply system.

[0004] The Chinese invention patent application number 202111500929.7 discloses an ammonia fuel engine supply system, including a liquid ammonia supply passage and a pilot gas supply passage; the liquid ammonia supply passage includes a liquid ammonia electronic injection valve, a high-pressure common rail pipe, a two-stage supercharger, and a first-stage supercharger; the pilot gas supply passage includes an ammonia storage tank, a pilot gas assembly unit, an engine, and a solenoid valve. This application can adjust the temperature and pressure of the pilot gas according to the load of the engine, and can adaptively adjust the engine to the optimal combustion condition. In addition, the high-temperature and high-pressure pilot gas can activate the ammonia fuel in the cylinder, improve the combustion characteristics of ammonia, and reduce the requirements for the engine's high compression ratio, high intake pressure and temperature and other combustion conditions. However, the structure of the ammonia fuel engine supply system is relatively simple, and the automation control capability is relatively poor. Summary of the Invention

[0005] The purpose of the present invention is to provide an ammonia supply system for an ammonia engine in order to overcome the deficiencies of the prior art.

[0006] To achieve the above object, the present invention adopts a technical solution: an ammonia supply system for an ammonia engine, comprising:

[0007] Liquid ammonia tank;

[0008] A boost circuit assembly; the boost circuit assembly includes a boost circuit water bath heater connected to the liquid ammonia tank through a first pipe, a first ammonia filter connected to the boost circuit water bath heater through a second pipe, a third pipe connected to the first ammonia filter at one end and the liquid ammonia tank at the other end, a first solenoid valve installed on the first pipe, an ammonia booster pump installed on the third pipe, and a check valve installed on the third pipe and located downstream of the ammonia booster pump;

[0009] An injection circuit assembly; the injection circuit assembly includes an injection circuit water bath heater connected to the liquid ammonia tank through a fourth pipe, a second solenoid valve installed on the fourth pipe, a fifth pipe connected to the injection circuit water bath heater at one end and connected to the ammonia injection assembly at the other end, a second ammonia filter installed on the fifth pipe, and a pressure reducing valve installed on the fifth pipe and located between the second ammonia filter and the injection circuit water bath heater.

[0010] Optimally, it also includes:

[0011] An ammonia exhaust component includes an exhaust branch pipe with one end connected to the third pipeline, a safety valve installed on the exhaust branch pipe, and a dissolved water tank connected to the other end of the exhaust branch pipe and having an exhaust outlet.

[0012] Furthermore, the boost circuit assembly further includes a first manual shut-off valve installed on the first pipeline and located upstream of the first solenoid valve, and a second manual shut-off valve installed on the third pipeline and located downstream of the check valve.

[0013] Furthermore, the injection circuit assembly further includes a third manual shut-off valve installed on the fourth pipeline and located upstream of the second solenoid valve.

[0014] Optimally, it also includes:

[0015] An engine coolant circuit assembly includes a coolant outlet pipe having one end connected to the ammonia engine, a third solenoid valve installed on the coolant outlet pipe, a first three-way valve connected to the other end of the coolant outlet pipe and connected to the boost circuit water bath heater and the injection circuit water bath heater respectively through two coolant inlet pipes, a second three-way valve connected to the boost circuit water bath heater and the injection circuit water bath heater respectively through two coolant return pipes, and a coolant return pipe connected to the second three-way valve and connected to the ammonia engine.

[0016] Another object of the present invention is to provide a method for controlling ammonia supply to an ammonia engine, which is based on the above-mentioned ammonia supply system to the ammonia engine.

[0017] Optimally, the following steps are included in no particular order:

[0018] (a) controlling the ammonia supply to the boost circuit through the boost circuit assembly;

[0019] (b) The injection circuit ammonia supply is controlled by the injection circuit assembly.

[0020] Furthermore, step (a) comprises the following steps:

[0021] (a1) allowing liquid ammonia to first pass through the first manual stop valve, and the liquid ammonia can only flow out after the first manual stop valve is opened;

[0022] (a2) The ECU controls the opening or closing of the first solenoid valve and the third solenoid valve based on the pressure in the liquid ammonia tank and the coolant temperature parameters; when the first solenoid valve is opened, liquid ammonia enters the boost circuit water bath heater to absorb heat and vaporize into ammonia gas; the heat source of the boost circuit water bath heater comes from the engine coolant, and whether the coolant enters the boost circuit water bath heater is controlled by the third solenoid valve;

[0023] (a3) the ammonia gas vaporized by the booster circuit water bath heater is then passed through the first ammonia filter to remove impurities in the ammonia gas; the ammonia gas is then pressurized by the ammonia booster pump and passed through the check valve to prevent backflow of the ammonia gas;

[0024] (a4) The ammonia gas is returned to the liquid ammonia tank after passing through the second manual stop valve.

[0025] Furthermore, step (b) comprises the following steps:

[0026] (b1) allowing liquid ammonia to first pass through the third manual stop valve, and the liquid ammonia can only flow out after the third manual stop valve is opened;

[0027] (b2) the ECU controls the opening and closing of the second solenoid valve according to engine operating conditions and coolant temperature parameters; when the second solenoid valve is opened, liquid ammonia enters the injection path water bath heater to absorb heat and vaporize into ammonia gas; the heat source of the injection path water bath heater is the engine coolant, and whether the coolant enters the injection path water bath heater is controlled by the third solenoid valve;

[0028] (b3) the ammonia gas vaporized by the injection circuit water bath heater passes through the pressure reducing valve, is decompressed, and then passes through the second ammonia filter to filter and remove impurities in the ammonia gas, and then enters the ammonia injection assembly;

[0029] (b4) The ECU controls ammonia injection according to the engine operating conditions. Ammonia passes through the ammonia-air mixer and enters the engine intake manifold, where it is combined with fresh air and then enters the engine cylinder for combustion.

[0030] Furthermore, in step (b3), the ammonia gas is decompressed to 5-8 bar by the pressure reducing valve.

[0031] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: the ammonia supply system of the ammonia engine of the present invention, by adopting structures such as a boost circuit component and an injection circuit component for coordination, can realize the design of an ammonia supply system from liquid storage to gaseous injection (that is, from ammonia storage-vaporization-decompression-injection-boosting and other functions as one), which can be used for the miniaturized ammonia supply and regulation of ammonia fuel engines, and can be installed on the whole vehicle or placed in the workplace. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the structure of the ammonia engine of the present invention;

[0033] Figure 2 This is a schematic structural diagram of the ammonia supply system of the ammonia engine of the present invention;

[0034] Figure 3 It is the overall framework diagram of the first relay control module;

[0035] Figure 4 This is the control logic block diagram of the first relay;

[0036] Figure 5 This is the overall framework diagram of the second relay control module;

[0037] Figure 6 This is the control logic block diagram of the second relay;

[0038] Figure 7 This is the overall framework diagram of the third relay control module;

[0039] Figure 8 This is the control logic block diagram of the third relay. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0041] like Figure 1 and Figure 2 The ammonia supply system of the ammonia engine shown mainly includes the following structures: liquid ammonia tank 1, boost circuit assembly 2, injection circuit assembly 3, ammonia exhaust assembly 4 and engine coolant circuit assembly 5 (note Figure 1 and Figure 2 are connected together in order to make Figure 1 and Figure 2 They are clearly shown and then separated by wavy lines).

[0042] The volume of the liquid ammonia tank 1 can be adjusted according to the vehicle space and fuel requirements, and is generally 400 to 1200 L. The tank contains liquid ammonia, and the pressure inside the tank will change with the ambient temperature. Its typical value is about 10 bar at 25°C.

[0043] The boost circuit assembly 2 includes a boost circuit water bath heater 21 connected to the liquid ammonia tank 1 through a first pipe 20, a first ammonia filter 23 connected to the boost circuit water bath heater 21 through a second pipe 22, a third pipe 24 connected to the first ammonia filter 23 at one end and to the liquid ammonia tank 1 at the other end, a first solenoid valve 25 installed on the first pipe 20, an ammonia booster pump 27 installed on the third pipe 24, and a check valve 28 installed on the third pipe 24 and located downstream of the ammonia booster pump 27. In this embodiment, the boost circuit assembly 2 also includes a first manual stop valve 26 installed on the first pipe 20 and located upstream of the first solenoid valve 25, and a second manual stop valve 29 installed on the third pipe 24 and located downstream of the check valve 28 (the definitions of upstream and downstream in this application are defined according to the flow direction of liquid ammonia or ammonia gas, the same below).

[0044] The injection circuit assembly 3 includes an injection circuit water bath heater 34 connected to the liquid ammonia tank 1 through a fourth pipe 31, a second solenoid valve 32 installed on the fourth pipe 31, and an ammonia injection assembly (see FIG. Figure 1 In the embodiment, a conventional fifth pipe 37, a second ammonia filter 36 installed on the fifth pipe 37, and a pressure reducing valve 35 installed on the fifth pipe 37 and located between the second ammonia filter 36 and the injection circuit water bath heater 34 can be used. In this embodiment, the injection circuit assembly 3 further includes a third manual shut-off valve 33 installed on the fourth pipe 31 and located upstream of the second solenoid valve 32.

[0045] The ammonia exhaust component 4 includes an exhaust branch pipe 41 connected to the third pipe 24 at one end, a safety valve 42 installed on the exhaust branch pipe 41, and a dissolved water tank 43 connected to the other end of the exhaust branch pipe 41 and having an exhaust outlet. The connection between the exhaust branch pipe 41 and the third pipe 24 is located downstream of the second manual stop valve 29, so that the ammonia can be absorbed and the ammonia pressure can be prevented from being excessive and overflowing to pollute the environment.

[0046] The engine coolant circuit assembly 5 is connected to the ammonia engine, allowing the engine to be cooled through the circulation of coolant. Specifically, it includes a coolant outlet pipe with one end connected to the ammonia engine, a third solenoid valve 51 mounted on the coolant outlet pipe, a first three-way valve 52 connected to the other end of the coolant outlet pipe and connected to the boost circuit water bath heater 21 and the injection circuit water bath heater 34 via two coolant inlet pipes, a second three-way valve 53 connected to the boost circuit water bath heater 21 and the injection circuit water bath heater 34 via two coolant return pipes, and a coolant return pipe connected to the second three-way valve 53 and to the ammonia engine. The heated engine coolant can be used to heat liquid ammonia, thereby improving the engine's thermal efficiency.

[0047] The method for controlling ammonia supply to an ammonia engine is based on the ammonia supply system of the ammonia engine and includes the following steps in no particular order:

[0048] (a) controlling the ammonia supply to the boost circuit through the boost circuit assembly 2; specifically, step (a) includes the following steps:

[0049] (a1) The liquid ammonia first passes through the first manual stop valve 26. The liquid ammonia can only flow out after the first manual stop valve 26 is opened;

[0050] (a2) The ECU controls the opening or closing of the first solenoid valve 25 and the third solenoid valve 51 based on parameters such as the pressure in the liquid ammonia tank 1 and the coolant temperature. When the first solenoid valve 25 is open, liquid ammonia enters the boost circuit water bath heater 21 to absorb heat and vaporize into ammonia gas. The heat source of the boost circuit water bath heater 21 comes from the engine coolant, and whether the coolant enters the boost circuit water bath heater 21 is controlled by the third solenoid valve 51.

[0051] (a3) The ammonia gas vaporized by the booster water bath heater 21 then passes through a first ammonia filter 23 to remove impurities in the ammonia gas. The ammonia gas is then pressurized by an ammonia booster pump 27 and passes through a check valve 28 to prevent backflow of the ammonia gas.

[0052] (a4) The ammonia gas is returned to the liquid ammonia tank 1 after passing through the second manual stop valve 29.

[0053] (b) controlling the ammonia supply of the injection circuit through the injection circuit assembly 3; specifically, step (b) includes the following steps:

[0054] (b1) The liquid ammonia first passes through the third manual stop valve 33. The liquid ammonia can only flow out after the third manual stop valve 33 is opened;

[0055] (b2) The ECU controls the opening and closing of the second solenoid valve 32 based on parameters such as the engine operating condition and the coolant temperature. When the second solenoid valve 32 is open, liquid ammonia enters the injection circuit water bath heater 34 to absorb heat and vaporize into ammonia gas. The heat source of the injection circuit water bath heater 34 is the engine coolant, and whether the coolant enters the injection circuit water bath heater 34 is controlled by the third solenoid valve 51.

[0056] (b3) The ammonia gas vaporized by the injection circuit water bath heater 34 then passes through a pressure reducing valve 35 (reduced to 5-8 bar, preferably 6 bar), and after the pressure reduction, passes through a second ammonia filter 36 to filter and remove impurities in the ammonia gas, and then enters the ammonia injection assembly;

[0057] (b4) The ECU controls ammonia injection according to the engine operating conditions. Ammonia passes through the ammonia-air mixer and enters the engine intake manifold, where it is combined with fresh air and then enters the engine cylinder for combustion.

[0058] In order to further improve the control accuracy of ammonia supply to the ammonia engine, the following functional control is also performed.

[0059] This application determines whether the third solenoid valve 51 needs to work based on the water temperature and speed. It does not directly control the third solenoid valve 51; instead, it uses the first relay to select whether the third solenoid valve 51 is energized. Its control variables are shown in Tables 1 to 3. The call cycle of the first relay is once every 50ms. It mainly determines whether the third solenoid valve 51 needs to work based on the water temperature and speed. Figure 3 and Figure 4 , the processing flow is as follows:

[0060] The enable main switch CTV_Actv_C is calibrated to 1, turning on the control of the third solenoid valve 51;

[0061] Judgment of the first relay's closing condition:

[0062] (1) The water temperature exceeds 40°C (this threshold is calibrated by CTV_OnECTThres_C);

[0063] (2) The speed exceeds 400 rpm (this threshold is calibrated by CTV_OnESPDThres_C); if the above conditions are met at the same time, the first relay pull-in flag outputs 1.

[0064] First relay disconnection condition judgment:

[0065] (1) The water temperature is lower than 35°C (the threshold is calibrated by CTV_OnECTThres_C-CTV_OffECTHys_C);

[0066] (2) The speed is lower than 300 rpm (the threshold is calibrated by CTV_OnESPDThres_C-CTV_OffESPDHys_C);

[0067] If any of the above conditions are met, the first relay pull-in flag outputs 0.

[0068] Table 1 List of first relay control input variables

[0069]

[0070] Table 2 List of output variables controlled by the first relay

[0071] variable name type Variable Description unit OUT_CoolantTankVlv_Flg bool First relay energized flag /

[0072] Table 3 List of first relay control calibration variables

[0073]

[0074]

[0075] The second solenoid valve 32 is also judged whether it needs to work based on the water temperature and the rotation speed. The second solenoid valve 32 is not directly controlled; instead, the second relay is used to select whether the second solenoid valve 32 is energized. Its control variables are shown in Tables 4 to 6. The call cycle of the second relay is once every 50ms. It mainly judges whether the second solenoid valve 32 needs to work based on the water temperature and the rotation speed. Figure 5 and Figure 6 , the processing flow is as follows:

[0076] The enable main switch FTV_Actv_C is calibrated to 1, turning on the control of the second solenoid valve 32;

[0077] Judgment of the second relay's closing condition:

[0078] (1) The water temperature exceeds 45°C (this threshold is calibrated by FTV_OnECTThres_C);

[0079] (2) The speed exceeds 400 rpm (this threshold is calibrated by FTV_OnESPDThres_C);

[0080] (3) After the third solenoid valve 51 is opened for 100 seconds (the threshold value is calibrated by FTV_CtvActvDlyTim_C) and the above conditions are met at the same time, the second relay pull-in flag outputs 1.

[0081] Second relay disconnection condition judgment:

[0082] (1) The water temperature is lower than 35°C (the threshold is calibrated by FTV_OnECTThres_C-FTV_OffECTHys_C);

[0083] (2) The speed is lower than 300 rpm (this threshold is calibrated by FTV_OnESPDThres_C-FTV_OffESPDHys_C);

[0084] (3) The third solenoid valve 51 is closed;

[0085] If any of the above conditions are met, the second relay pull-in flag outputs 0.

[0086] Table 4 List of second relay control input variables

[0087]

[0088] Table 5 List of second relay control output variables

[0089] variable name type Variable Description unit OUT_FuelTankVlv_Flg bool Second relay energized flag /

[0090] Table 6 List of second relay control calibration variables

[0091]

[0092] The first solenoid valve 25 is also judged whether it needs to work based on the water temperature, speed and pressure in the liquid ammonia tank 1. The first solenoid valve 25 is not directly controlled; instead, the third relay is used to select whether the first solenoid valve 25 is energized. Its control variables are shown in Tables 7 to 9. The call cycle of the third relay is once every 50ms. It mainly judges whether the first solenoid valve 25 needs to work based on the water temperature, speed and pressure in the liquid ammonia tank. Figure 7 and Figure 8 , the processing flow is as follows:

[0093] The enable main switch BGTV_Actv_C is calibrated to 1, turning on the control of the first solenoid valve 25;

[0094] Judgment of the third relay's closing condition:

[0095] (1) The water temperature exceeds 45°C (this threshold is calibrated by FTV_OnECTThres_C);

[0096] (2) The speed exceeds 400 rpm (this threshold is calibrated by FTV_OnESPDThres_C);

[0097] (3) The pressure in the liquid ammonia tank is lower than 100 kPa (the threshold is calibrated by BGTV_OffPNH3TankThres_C); if the above conditions are met at the same time, the relay energization flag outputs 1.

[0098] The third relay disconnection condition judgment:

[0099] (1) The water temperature is lower than 35°C (the threshold is calibrated by FTV_OnECTThres_C-FTV_OffECTHys_C);

[0100] (2) The speed is lower than 300 rpm (this threshold is calibrated by FTV_OnESPDThres_C-FTV_OffESPDHys_C);

[0101] (3) The pressure in the liquid ammonia tank is higher than 140kPa (the threshold is determined by BGTV_OffPNH3TankThres_C+

[0102] BGTV_PNH3TankHys_C calibration);

[0103] If any of the above conditions are met, the third relay pull-in flag outputs 0.

[0104] Table 7 List of third relay control input variables

[0105]

[0106] Table 8 List of output variables controlled by the third relay

[0107] variable name type Variable Description unit OUT_NH3TankVlv_Flg bool The third relay is on. / NH3_PumpEn_Flg bool Ammonia enable valid bit / NH3_TankEn_Flg bool Ammonia enable bit / NBP_RefSpd_Value int16_t Self-boosting pump target speed rpm

[0108] Table 9 List of third relay control calibration variables

[0109]

[0110] Ammonia booster pump 27 is a self-boosting pump, facilitating control of its NBP1 message output. After the third relay is energized, after a 100-second delay (delay time specified by J1939_BGTVDlyTim_C), the Ammonia Enable and Ammonia Enable Valid bits in the NBP1 message turn to 1, and bytes 2 and 3 of the message begin transmitting the self-boosting pump's target speed.

[0111] The self-boost pump target speed is determined by looking up the liquid ammonia tank pressure received via a message. The target speed lookup table is calibrated as NH3_PumpRefSpd_Crv. The speed value obtained from the lookup table is slope filtered, with an upper limit of 5000 rpm / s. After the third relay is disconnected, the ammonia enable bit and ammonia enable valid bit sent in the NBP1 message become 0, and the self-boost pump target speed is gradually filtered to 0.

[0112] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. An ammonia supply system for an ammonia engine, characterized in that it include: Liquid ammonia tank (1); A boost circuit assembly (2); the boost circuit assembly (2) comprises a boost circuit water bath heater (21) connected to the liquid ammonia tank (1) via a first pipe (20), a first ammonia filter (23) connected to the boost circuit water bath heater (21) via a second pipe (22), a third pipe (24) connected to the first ammonia filter (23) at one end and to the liquid ammonia tank (1) at the other end, a first solenoid valve (25) mounted on the first pipe (20), an ammonia boost pump (27) mounted on the third pipe (24), and a check valve (28) mounted on the third pipe (24) and located downstream of the ammonia boost pump (27); An injection circuit assembly (3); the injection circuit assembly (3) comprises an injection circuit water bath heater (34) connected to the liquid ammonia tank (1) through a fourth pipe (31), a second solenoid valve (32) installed on the fourth pipe (31), a fifth pipe (37) connected to the injection circuit water bath heater (34) at one end and connected to the ammonia injection assembly at the other end, a second ammonia filter (36) installed on the fifth pipe (37), and a pressure reducing valve (35) installed on the fifth pipe (37) and located between the second ammonia filter (36) and the injection circuit water bath heater (34).

2. The ammonia supply system for an ammonia engine according to claim 1, characterized in that: It also includes: An ammonia exhaust assembly (4), comprising an exhaust branch pipe (41) having one end connected to the third pipe (24), a safety valve (42) installed on the exhaust branch pipe (41), and a dissolved water tank (43) connected to the other end of the exhaust branch pipe (41) and having an exhaust port.

3. The ammonia supply system for an ammonia engine according to claim 1 or 2, characterized in that: The boost circuit assembly (2) further comprises a first manual shut-off valve (26) installed on the first pipe (20) and located upstream of the first solenoid valve (25), and a second manual shut-off valve (29) installed on the third pipe (24) and located downstream of the check valve (28).

4. The ammonia supply system for an ammonia engine according to claim 1 or 2, characterized in that: The injection circuit assembly (3) further comprises a third manual shut-off valve (33) mounted on the fourth pipe (31) and located upstream of the second solenoid valve (32).

5. The ammonia supply system for an ammonia engine according to claim 1, characterized in that: It also includes: An engine coolant circuit assembly (5), the engine coolant circuit assembly (5) comprising a coolant outlet pipe having one end connected to the ammonia engine, a third solenoid valve (51) mounted on the coolant outlet pipe, a first three-way valve (52) connected to the other end of the coolant outlet pipe and connected to the boost circuit water bath heater (21) and the injection circuit water bath heater (34) through two coolant inlet pipes, a second three-way valve (53) connected to the boost circuit water bath heater (21) and the injection circuit water bath heater (34) through two coolant return pipes, and a coolant return pipe connected to the second three-way valve (53) and connected to the ammonia engine.

6. A method for controlling ammonia supply to an ammonia engine, characterized by: It is based on the ammonia supply system for an ammonia engine as claimed in any one of claims 1 to 5.

7. The method for controlling ammonia supply to an ammonia engine according to claim 6, characterized in that: The steps are as follows in no particular order: (a) controlling the ammonia supply to the boost circuit through the boost circuit assembly (2); (b) Controlling the ammonia supply to the injection circuit by the injection circuit assembly (3).

8. The method for controlling ammonia supply to an ammonia engine according to claim 7, characterized in that: Step (a) comprises the following steps: (a1) allowing liquid ammonia to first pass through the first manual stop valve (26), and the liquid ammonia can only flow out after the first manual stop valve (26) is opened; (a2) The ECU controls the opening or closing of the first solenoid valve (25) and the third solenoid valve (51) according to the pressure in the liquid ammonia tank (1) and the coolant temperature parameters; when the first solenoid valve (25) is opened, liquid ammonia enters the boost circuit water bath heater (21) to absorb heat and vaporize into ammonia gas; the heat source of the boost circuit water bath heater (21) comes from the engine coolant, and whether the coolant enters the boost circuit water bath heater (21) is controlled by the third solenoid valve (51); (a3) The ammonia gas vaporized by the boosting circuit water bath heater (21) then passes through the first ammonia filter (23) to filter and remove impurities in the ammonia gas; the ammonia gas is then pressurized by the ammonia boosting pump (27) and passes through the check valve (28) to prevent backflow of the ammonia gas; (a4) The ammonia gas is allowed to pass through the second manual stop valve (29) and then return to the liquid ammonia tank (1).

9. The method for controlling ammonia supply to an ammonia engine according to claim 7, characterized in that: Step (b) comprises the following steps: (b1) allowing liquid ammonia to first pass through the third manual stop valve (33), and the liquid ammonia can only flow out after the third manual stop valve (33) is opened; (b2) The ECU controls the opening and closing of the second solenoid valve (32) according to the engine operating condition and the coolant temperature parameter; when the second solenoid valve (32) is opened, liquid ammonia enters the injection path water bath heater (34) to absorb heat and vaporize into ammonia gas; the heat source of the injection path water bath heater (34) comes from the engine coolant, and whether the coolant enters the injection path water bath heater (34) is controlled by the third solenoid valve (51); (b3) the ammonia gas vaporized by the injection circuit water bath heater (34) then passes through the pressure reducing valve (35), and after being reduced in pressure, passes through the second ammonia filter (36) to filter and remove impurities in the ammonia gas, and then enters the ammonia injection assembly; (b4) The ECU controls the injection of ammonia according to the engine operating conditions. Ammonia passes through the ammonia-air mixer and enters the engine intake manifold, where it is combined with fresh air and then enters the engine cylinder for combustion.

10. The method for controlling ammonia supply to an ammonia engine according to claim 9, characterized in that: In step (b3), the ammonia gas is decompressed to 5-8 bar through the pressure reducing valve (35).

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