Ammonia supply system, control method and readable storage medium

Abstract

This invention provides an ammonia supply system, a control method, and a readable storage medium, relating to the technical field of ammonia-fueled power systems. The ammonia supply system includes an ammonia supply module, an ammonia supply main pipe, an ammonia resonant tube, and an SCR reducing agent delivery pipeline. The SCR reducing agent pipeline supplies ammonia to the SCR unit, which uses ammonia as the reducing agent, simplifying the system structure. The ammonia resonant tube is connected to the ammonia supply main pipe via a first shut-off valve. A second shut-off valve is also provided on the SCR reducing agent delivery pipeline. The portion of the SCR reducing agent delivery pipeline between the second shut-off valve and the ammonia supply main pipe forms a resonant cavity. Through the ammonia resonant tube and the resonant cavity, the ammonia pressure wave in the ammonia supply main pipe can be partially offset, reducing ammonia fluctuations in the ammonia supply branch pipe before the ammonia injection valve opens.

Description

Technical Field

[0001] This invention relates to the field of ammonia-fueled power systems, and more specifically, to an ammonia supply system, a control method, and a readable storage medium. Background Technology

[0002] To control greenhouse gas emissions, researchers both domestically and internationally have conducted a series of exploratory studies on various technologies, focusing on carbon dioxide emission reduction targets. In the field of power systems, including engines, zero-carbon and low-carbon fuels such as ammonia, hydrogen, and methanol have become a research focus.

[0003] NH3 itself contains no carbon and can be produced through renewable energy sources via green pathways. Compared to H2, NH3 is simpler to synthesize, easier to store and transport, and has well-established and inexpensive existing infrastructure. Furthermore, NH3 is easily liquefied, has good anti-explosion properties, and a narrow flammability limit, making it less prone to explosion. Although toxic, its pungent odor makes it easily detectable, and its low density allows for easy diffusion. Under current technological conditions, NH3 is superior to H2 as a power source for mobile devices in terms of applicability, safety, and reliability.

[0004] In the engine field, due to limitations in related technological development, ammonia fuel is mostly supplied in the form of ammonia gas, and the combustible mixture is prepared using single-point or multi-point injection technology in the gas passage. When the overall ammonia substitution rate is high, the amount of ammonia required increases significantly compared to natural gas engines due to the lower calorific value of ammonia. Therefore, within a narrow injection pulse width, the periodic opening and closing of the ammonia injection valves in each cylinder will cause large pressure fluctuations in the ammonia supply line, leading to severe cyclic fluctuations and cylinder consistency issues.

[0005] Meanwhile, ammonia has an extremely high auto-ignition temperature, a low flame propagation speed, and a narrow flammability limit, thus presenting the potential for ignition difficulties, low combustion efficiency, and high unburned ammonia emissions. When high-energy spark plugs and highly reactive fuels such as diesel and hydrogen are used to ignite the combustible mixture, the type and combustion characteristics of the ignition fuel (mostly diesel and hydrogen) can lead to a significant increase in NOx emissions under certain loads and severe unburned NH3 emissions under certain operating conditions in ammonia-fueled engines. Therefore, to meet emission regulations, after-treatment technologies such as SCR units are essential for ammonia-fueled engines. Conventional SCR units generally use urea as a reducing agent, thus including structures such as a urea tank and a urea supply unit, which increases the overall structural complexity and manufacturing cost to some extent. Summary of the Invention

[0006] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0007] The present invention aims to provide an ammonia supply system that can improve the technical problems of large pressure fluctuations before the ammonia injection valve and complex overall structure in ammonia-fueled engines.

[0008] The present invention also aims to provide a control method for controlling an ammonia supply system, thereby improving the technical problems of large pressure fluctuations before the ammonia injection valve and complex overall structure in ammonia-fueled engines.

[0009] The present invention also aims to provide a readable storage medium that can improve the technical problems of large pressure fluctuations in front of the ammonia injection valve and complex overall structure in ammonia-fueled engines.

[0010] The embodiments of the present invention can be implemented in the following ways:

[0011] An ammonia supply system includes an ammonia supply module and an ammonia supply main pipe, one end of which is connected to the ammonia supply module, and a plurality of ammonia supply branch pipes are provided on the ammonia supply main pipe along its extension direction, the ammonia supply branch pipes being used to supply ammonia to the intake branch pipe of the engine through an ammonia injection valve.

[0012] An ammonia resonant tube, wherein the ammonia resonant tube is connected to the main ammonia supply pipe via a first shut-off valve, and the first shut-off valve is positioned closer to the ammonia supply module than the ammonia supply branch pipe; and

[0013] The SCR reducing agent delivery pipeline has one end connected to the other end of the ammonia supply main pipe, and the other end connected to the SCR unit to deliver ammonia to the SCR unit. A second shut-off valve is also provided on the SCR reducing agent delivery pipeline. The portion of the SCR reducing agent delivery pipeline between the second shut-off valve and the ammonia supply main pipe forms a resonant cavity, which is used to regulate the pressure of the ammonia supply main pipe when the second shut-off valve is closed.

[0014] Optionally, the ammonia supply system further includes a third shut-off valve disposed on the SCR reducing agent delivery pipeline. The third shut-off valve is disposed at one end of the second shut-off valve near the ammonia supply main pipe. The resonant cavity includes a first resonant cavity located between the third shut-off valve and the ammonia supply main pipe, and a second resonant cavity located between the second shut-off valve and the third shut-off valve.

[0015] Optionally, the volume of the first resonant cavity is greater than or equal to the volume of the ammonia supply branch pipe; and / or,

[0016] The volume of the second resonant cavity is greater than or equal to the volume of the ammonia supply branch pipe.

[0017] Optionally, the ammonia supply system further includes a purge collection pipeline and a collection and separation device. One end of the purge collection pipeline is connected to the SCR unit via a fourth shut-off valve, and the other end of the purge collection pipeline is connected to the collection and separation device. The collection and separation device is connected to the ammonia supply module via a first recovery pipeline and a second recovery pipeline. The collection and separation device is used to separate nitrogen and ammonia, and to transport the separated nitrogen to the ammonia supply module via the first recovery pipeline, and to transport the separated ammonia to the ammonia supply module via the second recovery pipeline.

[0018] Optionally, the diameter of the resonant cavity is D1, and the inner diameter of the ammonia supply branch pipe is D2, where D1 ≥ 1.5D2.

[0019] Optionally, the equivalent diameter of the resonant tube is greater than or equal to the diameter of the ammonia supply branch pipe.

[0020] A control method comprising determining whether to operate in ammonia mode;

[0021] If operating in ammonia mode, the engine load is acquired; when the engine load is greater than or equal to 75%, the first and second shut-off valves are opened; when the engine load is less than 75%, the first shut-off valve is opened and the second shut-off valve is closed.

[0022] If not operating in the ammonia mode, the first shut-off valve is closed and the second shut-off valve is opened.

[0023] Optionally, the ammonia supply system further includes a third shut-off valve disposed on the SCR reducing agent delivery pipeline, the third shut-off valve being disposed at the end of the second shut-off valve near the ammonia supply main; the step of controlling the first shut-off valve to open and the second shut-off valve to close when the engine load is less than 75% includes:

[0024] When the engine load is less than 75% and greater than 10%, the first and third shut-off valves are opened, and the second shut-off valve is closed.

[0025] When the engine load is less than or equal to 10%, the first shut-off valve is opened, and the second and third shut-off valves are closed.

[0026] If not operating in the ammonia mode, the steps of controlling the first shut-off valve to close and the second shut-off valve to open include:

[0027] If not operating in the ammonia mode, the first shut-off valve is closed, and the second and third shut-off valves are opened.

[0028] Optionally, the ammonia supply system further includes a purge collection pipeline, one end of which is connected to the SCR unit via a fourth shut-off valve, and the other end is connected to the ammonia supply module; the control method further includes:

[0029] When the engine is stopped, the first shut-off valve, the second shut-off valve and the fourth shut-off valve are opened, and the ammonia supply module is controlled to supply nitrogen to the ammonia supply main pipe.

[0030] Before the engine stops, while the engine is running, the fourth shut-off valve is controlled to close.

[0031] A readable storage medium storing a computer program that is executed by a processor to implement the control method described above.

[0032] The beneficial effects of the ammonia supply system, control method, and readable storage medium provided by the embodiments of the present invention include:

[0033] This invention provides an ammonia supply system, comprising an ammonia supply module, an ammonia supply manifold, an ammonia resonant tube, and an SCR reducing agent delivery pipeline. One end of the ammonia supply manifold is connected to the ammonia supply module to supply ammonia to the manifold via the module. Multiple ammonia supply branch pipes are arranged along the extension direction of the manifold, supplying ammonia to the engine's intake manifold via an ammonia injection valve. The ammonia resonant tube is connected to the manifold via a first shut-off valve, which is positioned closer to the ammonia supply module than the branch pipes. The resonant tube provides intake resonance, partially offsetting ammonia pressure waves within the manifold and reducing ammonia fluctuations in the branch pipes before the injection valve opens. One end of the SCR reducing agent delivery pipeline is connected to the other end of the ammonia supply main pipeline, and the other end of the SCR reducing agent delivery pipeline is used to connect to the SCR unit, thereby supplying ammonia to the SCR unit through the SCR reducing agent pipeline. The SCR unit uses ammonia as the reducing agent, thus simplifying the overall piping structure. A second shut-off valve is also installed on the SCR reducing agent delivery pipeline. The portion of the SCR reducing agent delivery pipeline between the second shut-off valve and the ammonia supply main pipeline forms a resonant cavity. When the second shut-off valve is closed, this resonant cavity can, to a certain extent, cancel out the ammonia pressure wave in the ammonia supply main pipeline, reducing ammonia fluctuations in the ammonia supply branch pipeline before the ammonia injection valve opens.

[0034] Embodiments of the present invention also provide a control method for controlling the aforementioned ammonia supply system. Furthermore, the control method includes, when the engine is operating in ammonia mode, controlling the opening and closing of a first shut-off valve and a second shut-off valve according to the engine load, thereby meeting the different needs of the engine under different load operating conditions, reducing ammonia fluctuations in the ammonia supply branch pipe before the ammonia injection valve opens, and simultaneously contributing to the simplification of the overall piping system.

[0035] Embodiments of the present invention also provide a readable storage medium in which a computer program stored in the readable storage medium is executed by a processor to implement the above-described control method. Therefore, it also has the beneficial effect of reducing ammonia fluctuations in the ammonia supply branch before the ammonia injection valve is opened, and at the same time helps to simplify the overall piping of the machine. Attached Figure Description

[0036] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0037] Figure 1 A schematic diagram of an ammonia supply system according to one aspect of the present invention is shown;

[0038] Figure 2 A structural block diagram of a control unit according to one aspect of the present invention is shown;

[0039] Figure 3 A control logic diagram of a control method according to one aspect of the present invention is shown.

[0040] Figure label:

[0041] 10-Engine; 11-Turbocharger; 12-Turbocharger inlet manifold; 13-Turbocharger rear intake manifold; 14-Intake branch manifold; 15-Cylinder; 16-Exhaust branch manifold; 17-Turbocharger front exhaust manifold; 18-Turbocharger rear exhaust manifold; 19-Control unit; 20-SCR unit; 30-Ammonia supply system; 31-Ammonia supply module; 32-Ammonia supply manifold; 33-Ammonia resonator tube; 34-Ammonia supply branch manifold; 35-Ammonia injection valve; 36-SCR reducing agent delivery pipeline; 37-Purge and collection pipeline; 38-Collection and separation device; 39-First recovery pipeline; 41-Second recovery pipeline; 42-Stop valve assembly; 43-First stop valve; 44-Second stop valve; 45-Third stop valve; 46-Fourth stop valve; 47-Resonant cavity; 48-First resonant cavity; 49-Second resonant cavity; 51-Readable storage medium; 52-Processor. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0043] In the description of this invention, it should be noted that if the terms "upper", "lower", "inner", "outer", "vertical", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, the device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0044] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0045] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] Figure 1 A schematic diagram of the ammonia supply system 30 provided in this embodiment is shown. Please refer to... Figure 1 This embodiment provides an ammonia supply system 30, which is used to supply ammonia to an ammonia-fueled engine (hereinafter referred to as engine 10).

[0047] Engine 10 has cylinders 15, intake manifolds, and exhaust manifolds. The intake manifolds include a supercharger inlet manifold 12, a supercharger rear intake manifold 13, and intake branch pipes 14 connected in sequence. The number of intake branch pipes 14 corresponds to the number of cylinders 15. For example... Figure 1 In the illustrated structure, engine 10 is a six-cylinder engine with six cylinders 15. Correspondingly, there are six intake manifolds 14, each connected to one of the six cylinders 15. Fresh air enters the turbocharger 11 through the turbocharger inlet manifold 12, is pressurized in the turbocharger 11, and then sequentially passes through the turbocharger rear intake manifold 13 and the intake manifolds 14 before entering each cylinder 15. The exhaust system includes sequentially connected exhaust manifolds 16, a turbocharger front exhaust manifold 17, and a turbocharger rear exhaust manifold 18. The number of exhaust manifolds 16 corresponds to the number of cylinders 15, for example... Figure 1 In the illustrated structure, engine 10 is a six-cylinder engine with six cylinders 15. Correspondingly, there are also six exhaust manifolds 16, each connected to one of the six cylinders 15. All six exhaust manifolds 16 are connected to the supercharger's front exhaust manifold 17. Exhaust gas enters the exhaust manifolds 16 from each cylinder 15 and then enters the supercharger 11 through the supercharger's front exhaust manifold 17. In the supercharger 11, the gas drives the turbine to rotate, thereby pressurizing the fresh air. After passing through the turbine, the gas enters the supercharger's rear exhaust manifold 18.

[0048] After the booster is installed on the exhaust manifold, an SCR (Selective Catalytic Reduction) unit is installed to treat the exhaust gas.

[0049] The ammonia supply system 30 includes an ammonia supply module 31, an ammonia supply main pipe 32, an ammonia resonant tube 33, and an SCR reducing agent delivery pipeline 36. One end of the ammonia supply main pipe 32 is connected to the ammonia supply module 31, and the other end of the ammonia supply main pipe 32 is connected to the SCR reducing agent delivery pipeline 36. The end of the SCR reducing agent delivery pipeline 36 away from the ammonia supply main pipe 32 is connected to the SCR unit 20. The ammonia supplied in the ammonia supply module 31 can enter the SCR unit 20 along the path of the ammonia supply main pipe 32 and the SCR reducing agent delivery pipeline 36. The SCR unit 20 uses ammonia as a reducing agent to treat the waste gas.

[0050] The main ammonia supply pipe 32 is equipped with multiple ammonia supply branch pipes 34, the number of which corresponds to the number of inlet branch pipes 14, for example... Figure 1 In the illustrated structure, engine 10 is a six-cylinder engine, which supplies fresh air to cylinders 15 through six intake manifolds 14. Correspondingly, there are six ammonia supply manifolds 34, which supply ammonia to the six intake manifolds 14 respectively through ammonia injection valves 35. In other words, in the configuration shown... Figure 1 In the structure shown, there are six ammonia injection valves 35. Obviously, in other embodiments, the number of intake manifold 14, exhaust manifold 16, ammonia supply manifold 34, and ammonia injection valves 35 is adjusted according to the number of cylinders 15 of engine 10. For example, if engine 10 is a four-cylinder engine, the number of intake manifold 14, exhaust manifold 16, ammonia supply manifold 34, and ammonia injection valves 35 is set to four.

[0051] Multiple ammonia supply branch pipes 34 are arranged sequentially along the extension direction of the ammonia supply main pipe 32, that is, multiple ammonia supply branch pipes 34 are respectively arranged at different axial positions of the ammonia supply main pipe 32.

[0052] The ammonia resonant tube 33 is connected to the ammonia supply main pipe 32 via a first shut-off valve 43, which controls the connection between the ammonia resonant tube 33 and the ammonia supply main pipe 32. Specifically, one end of the ammonia resonant tube 33 is connected to the first shut-off valve 43, and the other end is closed. When the first shut-off valve 43 is open and the ammonia resonant tube 33 is connected to the ammonia supply main pipe 32, ammonia gas in the ammonia supply main pipe 32 enters the ammonia resonant tube 33, and the ammonia resonant tube 33 performs a resonant function, thereby reducing the pressure wave of ammonia gas in the ammonia supply main pipe 32, which helps the ammonia injection valve 35 to supply ammonia gas smoothly to the intake branch pipe 14. The first shut-off valve 43 is located closer to the ammonia supply module 31 than the ammonia supply branch pipe 34. In other words, if the ammonia supply branch pipe 34 closest to the ammonia supply module 31 is defined as the first ammonia supply branch pipe, then the first shut-off valve 43 is located between the first ammonia supply branch pipe and the ammonia supply module 31.

[0053] A second shut-off valve 44 is also provided on the SCR reducing agent delivery pipeline 36. The second shut-off valve 44 controls the on / off of the supply of ammonia to the SCR unit. Specifically, when the second shut-off valve 44 is in the open state, the ammonia in the ammonia supply main pipe 32 enters the SCR unit 20 through the SCR reducing agent delivery pipeline 36; when the second shut-off valve 44 is in the closed state, the ammonia supply main pipe 32 stops supplying ammonia to the SCR unit 20.

[0054] Simultaneously, the portion of the SCR reducing agent delivery pipeline 36 located between the second shut-off valve 44 and the ammonia supply main pipe 32 forms a resonant cavity 47. When the second shut-off valve 44 is closed, the resonant cavity 47 functions as a resonant chamber, regulating the pressure within the ammonia supply main pipe 32 and mitigating the problem of large pressure fluctuations before the ammonia injection valve 35. Specifically, the resonant cavity 47 is... Figure 1 The dashed box indicates the area within the diagram. In this embodiment, the volume of the resonant cavity 47 is greater than or equal to the volume of the ammonia supply branch pipe 34. Furthermore, in this embodiment, the diameter of the resonant cavity 47 is D1, and the inner diameter of the ammonia supply branch pipe 34 is D2, where D1 ≥ 1.5D2. The inner diameter of the ammonia supply branch pipe 34 can be determined based on the designed ammonia flow rate. The equivalent diameter of the resonant tube should be greater than or equal to the diameter of the ammonia supply branch pipe 34.

[0055] It should be noted that the diameter of the resonant cavity 47 is the same as the inner diameter of the SCR reducing agent delivery pipeline 36.

[0056] Furthermore, the ammonia supply system 30 also includes a third shut-off valve 45 disposed on the SCR reducing agent delivery pipeline 36. The third shut-off valve 45 is located at the end of the second shut-off valve 44 near the ammonia supply main pipe 32, thereby dividing the resonant cavity 47 into two parts. Specifically, the resonant cavity 47 includes a first resonant cavity 48 and a second resonant cavity 49. The first resonant cavity 48 is located between the third shut-off valve 45 and the ammonia supply main pipe 32, and the second resonant cavity 49 is located between the second shut-off valve 44 and the third shut-off valve 45. By controlling the second shut-off valve 44 and the third shut-off valve 45, pressure regulation within the ammonia supply main pipe 32 can be achieved more effectively. It is understood that in other embodiments, if only one shut-off valve is disposed on the SCR reducing agent delivery pipeline 36, the resonant cavity 47 will only include the first resonant cavity 48.

[0057] In this embodiment, the volume of the first resonant cavity 48 is greater than or equal to the volume of the ammonia supply branch pipe 34. The volume of the second resonant cavity 49 is greater than or equal to the volume of the ammonia supply branch pipe 34. Obviously, in this embodiment, the volume of the resonant cavity 47 is greater than or equal to twice the volume of the ammonia supply branch pipe 34. In other embodiments, the volume of the resonant cavity 47 can also be specifically set. For example, when the resonant cavity 47 only includes the first resonant cavity 48, the volume of the resonant cavity 47 can also be set to be greater than or equal to the volume of the ammonia supply branch pipe 34.

[0058] In this embodiment, the ammonia supply system 30 further includes a purge collection pipeline 37 and a collection and separation device 38. One end of the purge collection pipeline 37 is connected to the SCR unit 20 via a fourth shut-off valve 46, and the other end of the purge collection pipeline 37 is connected to the collection and separation device 38. The collection and separation device 38 is connected to the ammonia supply module 31 via a first recovery pipeline 39 and a second recovery pipeline 41. The collection and separation module is used to separate nitrogen and ammonia, and to transport the separated nitrogen to the ammonia supply module 31 via the first recovery pipeline 39, and to transport the separated ammonia to the ammonia supply module 31 via the second recovery pipeline 41. Obviously, in this embodiment, the ammonia supply module 31 has the function of supplying nitrogen in addition to supplying ammonia. Optionally, the ammonia supply module 31 can be configured to include mutually independent ammonia storage or generation structures and nitrogen storage or generation structures. After the engine 10 stops (normal stop and emergency stop), the fourth shut-off valve 46 is opened to control the ammonia supply module 31 to supply nitrogen. The nitrogen purges the ammonia in the ammonia resonant tube 33, the ammonia supply main pipe 32, the ammonia supply branch pipe 34, and the SCR reducing agent supply pipeline. The mixed gas of ammonia and nitrogen enters the collection and separation device 38 through the SCR unit 20 and the purging collection pipeline 37. Under the action of the collection and separation device 38, the ammonia in the mixed gas returns to the ammonia supply module 31 through the second recovery pipeline 41, and the nitrogen in the mixed gas returns to the ammonia supply module 31 through the first recovery pipeline 39, thereby realizing the recovery, separation, and secondary utilization of ammonia and nitrogen.

[0059] It should be noted that, Figure 1 The gas in the ammonia supply system 30 shown is the state of the ammonia supply system 30 during the purging process, and the gas at the engine 10 is the gas flow state during the operation of the engine 10.

[0060] Figure 2 A structural block diagram of the control unit 19 provided in this embodiment is shown. Figure 3 The control logic diagram of the control method provided in this embodiment is shown. Please refer to... Figures 1-3This embodiment also provides a control unit 19 for controlling the ammonia supply system 30. The control unit 19 is located in the engine 10. Optionally, the control unit 19 may be the ECU of the engine 10.

[0061] The control unit 19 includes a readable storage medium 51 and a processor 52. The readable storage medium 51 stores a computer-readable computer program, which is executed by the processor 52 to implement one or more steps of the control method. Specifically, the readable storage medium 51 can be any available medium that a computer can store, or a data storage device such as a server or data center that integrates one or more available media.

[0062] The processor 52 controls various components in the ammonia supply system 30, such as the shut-off valve assembly 42, according to a control method. In this embodiment, the shut-off valve assembly 42 includes a first shut-off valve 43, a second shut-off valve 44, a third shut-off valve 45, and a fourth shut-off valve 46.

[0063] In this embodiment, the control method includes the following steps:

[0064] S01: Determine whether to run in ammonia mode.

[0065] In this embodiment, when the engine 10 is operating in ammonia mode, the ammonia substitution rate is 50%-95%.

[0066] S02: If operating in ammonia mode, obtain engine load 10.

[0067] In this embodiment, the load of engine 10 is obtained by acquiring the engine speed.

[0068] S21: When the engine 10 is operating at a load greater than or equal to 75%, i.e., under high load conditions, the pressure fluctuation before the ammonia injection valve 35 in each cylinder is small due to the influence of ammonia demand, injection pulse width, and ammonia injection valve characteristics. Meanwhile, the NOx content in the exhaust manifold 18 after the turbocharger is greater than or equal to the unburned NH3 content. At this time, the first shut-off valve 43, the second shut-off valve 44, and the third shut-off valve 45 are opened, the ammonia resonant pipe 33 acts as an ammonia intake resonant, and the SCR reductant supply pipeline functions to supply ammonia to the SCR unit 20. Thus, the entire ammonia supply system 30 simultaneously provides ammonia fuel and SCR reductant. It is understood that in other embodiments, if only the second shut-off valve 44 is installed on the SCR reductant supply pipeline 36, then the first shut-off valve 43 and the second shut-off valve 44 are opened.

[0069] When the engine load is less than 75%, the first shut-off valve 43 is opened and the second shut-off valve 44 is closed. At this time, the SCR reducing agent delivery pipeline 36 stops supplying ammonia to the SCR unit 20, and the resonant cavity 47 and the ammonia resonant tube 33 both play a resonant role.

[0070] S22: In this embodiment, when the engine 10 is operating at a load less than 75% and greater than 10%, i.e., under medium to low load conditions, the ammonia demand decreases, the ammonia injection pulse width decreases, and the pressure fluctuation before the ammonia injection valve 35 in each cylinder is greater than under high load conditions. Due to factors such as combustion temperature, the amount of unburned ammonia in the cylinder increases sharply, and the amount of unburned NH3 in the exhaust manifold 18 after the turbocharger is much greater than the NOx content. Therefore, there is no need to provide additional reducing agent to the SCR unit 20. At this time, the first shut-off valve 43 and the third shut-off valve 45 are opened, and the second shut-off valve 44 is closed. The first resonant cavity 48, the second resonant cavity 49, and the ammonia resonant tube 33 all play a resonant role, which cancels out the pressure waves formed in the ammonia supply manifold 32 and the ammonia supply branch pipe 34 to a certain extent, reducing the pressure fluctuation in the ammonia supply branch pipe 34 before the ammonia injection valve 35 is opened. The entire ammonia supply system 30 only realizes the function of supplying ammonia fuel.

[0071] S23: When the load of engine 10 is less than or equal to 10%, that is, when engine 10 is operating under low load, the pressure fluctuation in the ammonia supply branch pipe 34 before ammonia injection valve 35 is smaller than when operating under medium and low load. Therefore, the required volume of resonant cavity 47 becomes smaller, controlling the first shut-off valve 43 to open, and the second shut-off valve 44 and the third shut-off valve 45 to close. The ammonia resonant tube 33 and the first resonant cavity 48 work together to play a resonant role.

[0072] S03: If not operating in ammonia mode, control the first shut-off valve 43 to close and the second shut-off valve 44 to open.

[0073] If the engine 10 is not operating in ammonia mode, the ammonia supply system 30 only needs to perform the SCR reductant delivery function. In this case, the first shut-off valve 43 is closed and the second shut-off valve 44 is open. In this embodiment, since the SCR reductant delivery pipeline 36 is equipped with a second shut-off valve 44 and a third shut-off valve 45, in order to ensure that the SCR reductant delivery pipeline 36 is unobstructed and to achieve the SCR reductant delivery function, when the engine 10 is not operating in ammonia mode, both the second shut-off valve 44 and the third shut-off valve 45 need to be opened.

[0074] It should be noted that during the operation of the engine 10, that is, during the execution of steps S01, S02 and S03, the SCR unit 20 is in working condition.

[0075] S04: When the engine 10 is stopped, control the first shut-off valve 43, the second shut-off valve 44, the third shut-off valve 45 and the fourth shut-off valve 46 to open, and control the ammonia supply module 31 to supply nitrogen to the ammonia supply main pipe 32.

[0076] In the event of a normal or emergency shutdown of the engine 10, the first shut-off valve 43, the second shut-off valve 44, the third shut-off valve 45, and the fourth shut-off valve 46 are opened, and the ammonia supply module 31 is controlled to supply nitrogen to the ammonia supply main pipe 32, thereby purging the ammonia in the ammonia supply system 30 and realizing the recovery and reuse of ammonia. Specifically, during the purging process, the mixture of ammonia and nitrogen in the ammonia supply system 30 enters the collection and separation device 38 through the purging collection pipe 37. The collection and separation device 38 operates to separate the ammonia and nitrogen in the mixture. The separated nitrogen returns to the ammonia supply module 31 through the first recovery pipe 39, and the separated ammonia returns to the ammonia supply module 31 through the second recovery pipe 41.

[0077] It should be noted that since the function of the purging collection pipeline 37 is to purge ammonia after the engine 10 is stopped, the fourth shut-off valve 46 is in the closed state before the engine 10 is stopped and while the engine 10 is running, that is, during the execution of steps S01, S02 and S03.

[0078] The ammonia supply system 30, control method, and readable storage medium provided in the embodiments of the present invention simultaneously possess the functions of ammonia inlet resonance, SCR reducing agent delivery, overall machine safety, and purge gas collection, recovery, separation, and secondary utilization. The structure and control method are simple and easy to maintain. It effectively addresses the problem of large pressure fluctuations before the ammonia injection valve. Furthermore, through simulation analysis of the ammonia supply system 30 provided in this embodiment for a six-cylinder engine, the maximum ammonia demand flow rate, inlet pressure, and temperature were determined based on the overall machine performance indicators. The design flow rate of ammonia was set at 10 m / s. Simulation results show that adding an SCR reducing agent delivery pipeline 36 as a resonant cavity 47 to the ammonia supply system 30 can effectively suppress pressure fluctuations in the ammonia supply pipeline under different loads and ammonia substitution rates.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An ammonia supply system, characterized in that, The ammonia supply system includes: Ammonia supply module; An ammonia supply main pipe is provided, one end of which is connected to the ammonia supply module. Multiple ammonia supply branch pipes are provided on the ammonia supply main pipe along its extension direction. The ammonia supply branch pipes are used to supply ammonia to the intake branch pipe of the engine through an ammonia injection valve. An ammonia resonant tube, wherein the ammonia resonant tube is connected to the main ammonia supply pipe via a first shut-off valve, and the first shut-off valve is positioned closer to the ammonia supply module than the ammonia supply branch pipe; and The SCR reducing agent delivery pipeline has one end connected to the other end of the ammonia supply main pipe, and the other end connected to the SCR unit to deliver ammonia to the SCR unit. A second shut-off valve is also provided on the SCR reducing agent delivery pipeline. The portion of the SCR reducing agent delivery pipeline between the second shut-off valve and the ammonia supply main pipe forms a resonant cavity, which is used to regulate the pressure of the ammonia supply main pipe when the second shut-off valve is closed.

2. The ammonia supply system according to claim 1, characterized in that, The ammonia supply system further includes a third shut-off valve disposed on the SCR reducing agent delivery pipeline. The third shut-off valve is disposed at one end of the second shut-off valve near the ammonia supply main pipe. The resonant cavity includes a first resonant cavity located between the third shut-off valve and the ammonia supply main pipe, and a second resonant cavity located between the second shut-off valve and the third shut-off valve.

3. The ammonia supply system according to claim 2, characterized in that, The volume of the first resonant cavity is greater than or equal to the volume of the ammonia supply branch pipe; and / or, The volume of the second resonant cavity is greater than or equal to the volume of the ammonia supply branch pipe.

4. The ammonia supply system according to claim 1, characterized in that, The ammonia supply system further includes a purge collection pipeline and a collection and separation device. One end of the purge collection pipeline is connected to the SCR unit via a fourth shut-off valve, and the other end of the purge collection pipeline is connected to the collection and separation device. The collection and separation device is connected to the ammonia supply module via a first recovery pipeline and a second recovery pipeline. The collection and separation device is used to separate nitrogen and ammonia, and to transport the separated nitrogen to the ammonia supply module via the first recovery pipeline, and to transport the separated ammonia to the ammonia supply module via the second recovery pipeline.

5. The ammonia supply system according to claim 1, characterized in that, The diameter of the resonant cavity is D1, and the inner diameter of the ammonia supply branch pipe is D2, where D1 ≥ 1.5D2.

6. The ammonia supply system according to claim 1, characterized in that, The equivalent diameter of the resonant tube is greater than or equal to the diameter of the ammonia supply branch pipe.

7. A control method for controlling the ammonia supply system of claim 1, characterized in that, The control method includes: Determine whether to run in ammonia mode; If operating in ammonia mode, the engine load is acquired; when the engine load is greater than or equal to 75%, the first and second shut-off valves are opened; when the engine load is less than 75%, the first shut-off valve is opened and the second shut-off valve is closed. If not operating in the ammonia mode, the first shut-off valve is closed and the second shut-off valve is opened.

8. The control method according to claim 7, characterized in that, The ammonia supply system further includes a third shut-off valve installed on the SCR reducing agent delivery pipeline, the third shut-off valve being located at the end of the second shut-off valve near the ammonia supply main pipeline; the steps of controlling the first shut-off valve to open and the second shut-off valve to close when the engine load is less than 75% include: When the engine load is less than 75% and greater than 10%, the first and third shut-off valves are opened, and the second shut-off valve is closed. When the engine load is less than or equal to 10%, the first shut-off valve is opened, and the second and third shut-off valves are closed. If not operating in the ammonia mode, the steps of controlling the first shut-off valve to close and the second shut-off valve to open include: If not operating in the ammonia mode, the first shut-off valve is closed, and the second and third shut-off valves are opened.

9. The control method according to claim 7, characterized in that, The ammonia supply system further includes a purge collection pipeline, one end of which is connected to the SCR unit via a fourth shut-off valve, and the other end is connected to the ammonia supply module; the control method further includes: When the engine is stopped, the first shut-off valve, the second shut-off valve and the fourth shut-off valve are opened, and the ammonia supply module is controlled to supply nitrogen to the ammonia supply main pipe. Before the engine stops, while the engine is running, the fourth shut-off valve is controlled to close.

10. A readable storage medium, characterized in that, The readable storage medium stores a computer program that is executed by a processor to implement the control method according to any one of claims 7-9.

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