Gas ammonia fuel supply device and method for ammonia engine for vehicle

Abstract

The present application belongs to the internal combustion engine technical field, especially relates to a kind of ammonia engine's gas ammonia fuel supply device and method for vehicle, including liquid ammonia storage tank, pressure regulating mechanism is provided on it, liquid ammonia storage tank provides ammonia to engine by first air inlet pipeline, heating mechanism and buffer tank are sequentially provided on first air inlet pipeline along ammonia flow direction, heating mechanism includes electric heating assembly and first heat exchange component with engine coolant heat exchange flow channel, second temperature / pressure sensor is provided in the end of first air inlet pipeline close to engine, its signal is connected with front controller, and front controller obtains saturated vapor pressure under current temperature based on ammonia temperature at pipeline outlet end, when the pressure in storage tank is less than saturated vapor pressure, control pressure regulating mechanism to increase the pressure of storage tank.The present application reduces external power consumption by waste heat vaporization and active pressure regulation, effectively prevents ammonia liquefaction, and ensures stable supply.

Description

Technical Field

[0001] This invention belongs to the field of internal combustion engine technology, and particularly relates to a gaseous ammonia fuel supply device and method for an ammonia engine for vehicles. Background Technology

[0002] In recent years, with the advancement of global carbon neutrality goals, the internal combustion engine industry has been actively seeking low-carbon and even zero-carbon alternative fuels. Ammonia, as a renewable and clean energy source containing no carbon molecules, does not produce carbon dioxide during combustion, significantly reducing greenhouse gas emissions. Furthermore, ammonia is abundant, its production technology is mature, and it can be produced using renewable energy sources such as wind and solar power. A relatively complete "production, storage, and transportation" infrastructure system for ammonia has been established globally. Ammonia can be stored in liquid form under pressure of 1 MPa or at a low temperature of -34°C, offering the advantage of relatively low transportation and storage costs. Therefore, it is considered one of the important options for replacing traditional fossil fuels and addressing energy security issues.

[0003] However, using ammonia as a fuel for vehicle engines still faces several technical bottlenecks that need to be overcome. First, liquid ammonia has a high latent heat of vaporization, approximately 1370 joules / gram at room temperature and pressure. Relying solely on the gas cylinder's absorption of heat from the environment is insufficient to meet the heat required for liquid ammonia vaporization. Current technologies typically employ continuous electric heating to maintain the vaporization process, resulting in high system energy consumption. In vehicle applications, continuous electrical consumption necessitates larger capacity batteries or increased generator load, increasing both vehicle cost and energy efficiency. Second, ammonia has a low saturated vapor pressure, only about 8.574 bar at 20°C. When engine operating conditions change rapidly, the pressure in the gas supply line is prone to sudden changes, easily causing ammonia to reliquefy in the gas supply line, creating vapor lock, which can lead to interruption of ammonia supply or even damage to pipeline components, severely affecting the normal operation and reliability of the engine. Summary of the Invention

[0004] The purpose of this invention is to provide a gaseous ammonia fuel supply device and method for a vehicle ammonia engine to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention provides the following solution: A gaseous ammonia fuel supply device for an automotive ammonia engine includes: a liquid ammonia storage tank, a pressure regulating mechanism provided on the liquid ammonia storage tank, the liquid ammonia storage tank supplying ammonia to the engine through a first intake pipe, a heating mechanism and a buffer tank being sequentially arranged along the ammonia flow direction on the first intake pipe, and the ammonia flowing out from the heating mechanism and then into the buffer tank, and subsequently flowing out from the buffer tank and into the engine, and a flow control component being provided on the first intake pipe; The heating mechanism includes an electric heating component disposed on the first intake pipe, the electric heating component being connected to a first heat exchange component, the first heat exchange component being provided with a heat exchange channel for the engine coolant to flow through. A second temperature / pressure sensor is provided at one end of the first intake pipe near the engine. The second temperature / pressure sensor is used to obtain the temperature and pressure of ammonia at the outlet of the first intake pipe. The signal of the second temperature / pressure sensor is connected to the front controller. The front controller is electrically connected to the pressure regulating mechanism, the electric heating component, the buffer tank, and the flow control component.

[0006] Preferably, the flow control component includes a manual valve, a flow valve, a shut-off valve, a first pressure regulating valve, and a first flow meter, which are sequentially arranged along the ammonia flow direction on the first inlet pipe. The manual valve and the flow valve are located upstream of the electric heating component, the shut-off valve is located between the buffer tank and the electric heating component, and the first pressure regulating valve is located downstream of the buffer tank. The flow valve, the shut-off valve, the first pressure regulating valve, and the first flow meter are all signal-connected to the front controller.

[0007] Preferably, the pressure regulating mechanism includes a partition disposed inside the liquid ammonia storage tank, the partition dividing the inner cavity of the liquid ammonia storage tank into a pressure control chamber and a liquid ammonia storage chamber, the partition being slidably disposed along the length direction of the liquid ammonia storage tank, the partition having a through hole, an elastic diaphragm being fixedly connected to the through hole, a displacement sensor being disposed between the partition and the liquid ammonia storage tank, and a deformation sensor being disposed on the elastic diaphragm; The pressure control chamber is connected to an air pump, and a pressure valve is provided between the air pump and the pressure control chamber. The air pump, the pressure valve, the displacement sensor, and the deformation sensor are all connected to the front controller via signal connection.

[0008] Preferably, the electric heating assembly includes a heater disposed on the first air intake pipe, the heater being electrically connected to a power source, and the heater being signal-connected to the front controller; The first heat exchange assembly includes a heat exchanger disposed on the engine and a first heat exchange pipeline connected to the heat exchanger. The first heat exchange pipeline is connected to the heater and is used for the circulation of coolant between the heat exchanger and the heater.

[0009] Preferably, the outlet end of the first air intake pipe is provided with an ammonia injection nozzle, the outlet end of the ammonia injection nozzle is connected to the mixing tank, the mixing tank is provided with an air inlet and a mixed gas outlet, and the mixed gas outlet of the mixing tank is connected to the air intake end of the engine.

[0010] Preferably, the first intake pipe is connected to a second intake pipe, and the connection point between the second intake pipe and the first intake pipe is located between the buffer tank and the first pressure regulating valve. A second pressure regulating valve and a second flow meter are sequentially arranged on the second intake pipe along the ammonia flow direction. The outlet of the second intake pipe is connected to the SCR through another ammonia injection nozzle. The SCR is connected to the engine outlet. The SCR, the second pressure regulating valve, and the second flow meter are all signal-connected to the aftertreatment controller.

[0011] Preferably, water jackets are fitted on the outer sides of both the first and second air inlet pipes, and a second heat exchange pipe is provided on the buffer tank. Both the water jacket and the second heat exchange pipe are connected to the heat exchanger.

[0012] Preferably, the front controller is connected to an ammonia sensor, which is used to detect ammonia leakage.

[0013] Preferably, a first temperature / pressure sensor is provided inside the mixing tank, and the first temperature / pressure sensor is signal-connected to the front controller.

[0014] A method for supplying gaseous ammonia fuel to a vehicle ammonia engine, based on the aforementioned gaseous ammonia fuel supply device for the vehicle ammonia engine, includes the following steps: The front controller acquires the temperature and pressure of ammonia at the outlet of the first inlet pipe and the temperature and pressure of ammonia in the buffer tank. Based on the temperature and pressure of ammonia at the outlet of the first inlet pipe, it acquires the saturated vapor pressure and density of ammonia at the current temperature. It compares the internal pressure of the liquid ammonia storage tank with the saturated vapor pressure of ammonia at the current temperature. When the internal pressure of the liquid ammonia storage tank is less than the saturated vapor pressure, it controls the pressure regulating mechanism to increase the internal pressure of the liquid ammonia storage tank. The engine coolant temperature is obtained, and when the coolant temperature reaches a preset threshold, the heating power of the electric heating component is controlled to decrease as the coolant temperature increases. The mass flow rate of ammonia is calculated based on the density of ammonia and the cross-sectional area of ​​the outlet end of the first intake pipe. The ammonia demand is determined according to the mass flow rate and the instantaneous operating conditions of the engine, and a flow adjustment signal corresponding to the ammonia demand is sent to the flow control component. The pressure of ammonia in the buffer tank is compared with the saturated vapor pressure of ammonia at the current temperature. When the pressure in the buffer tank is close to the saturated vapor pressure, the flow control component reduces the liquid ammonia supply and the electric heating component increases the heating power, so that the temperature of the downstream pipeline and the buffer tank of the heating mechanism increases and the pressure decreases.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: In this invention, a heating mechanism comprising an electric heating component and a first heat exchange component with an engine coolant heat exchange channel is installed on the first intake pipe. This allows liquid ammonia vaporization to utilize the waste heat of the engine coolant as the primary heat source, using electric heating only during engine start-up and warm-up. This effectively reduces the dependence of liquid ammonia vaporization on external electrical energy, lowering system operating energy consumption and overall vehicle cost. Simultaneously, a second temperature / pressure sensor is installed near the engine end to acquire the temperature and pressure of ammonia at the pipe outlet in real time. The front controller then uses this temperature to obtain the saturated vapor pressure of ammonia at the current temperature. When the internal pressure of the liquid ammonia storage tank is lower than this saturated vapor pressure, the pressure regulating mechanism is controlled to increase the tank pressure. This ensures that the liquid ammonia is always maintained above the required liquid pressure in the liquid phase pipeline section from the storage tank to the heating mechanism. Combined with the buffer tank's absorption and stabilization of pressure fluctuations in the gas phase section, this effectively prevents ammonia from liquefying in the supply pipeline due to insufficient pressure, thus avoiding vapor lock and ensuring the continuity and stability of ammonia supply, thereby improving the system's operational reliability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the partition structure in this invention; The components include: 1. Liquid ammonia storage tank; 2. Manual valve; 3. Flow valve; 4. Shut-off valve; 5. First pressure regulating valve; 6. First flow meter; 7. Ammonia injection nozzle; 8. Mixing tank; 9. Engine; 10. Front controller; 11. Pressure valve; 12. Air pump; 13. Buffer tank; 14. Power supply; 15. Heater; 16. Ammonia sensor; 17. Aftertreatment controller; 18. Second pressure regulating valve; 19. Second flow meter; 20. First temperature / pressure sensor; 21. Second temperature / pressure sensor; 22. SCR; 23. First air intake pipe; 24. Second air intake pipe; 25. First heat exchange pipe; 26. Second heat exchange pipe; 27. Baffle; 28. Elastic diaphragm. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Reference Figures 1 to 2 This invention discloses a gaseous ammonia fuel supply device for a vehicle ammonia engine, comprising: a liquid ammonia storage tank 1, a pressure regulating mechanism provided on the liquid ammonia storage tank 1, the liquid ammonia storage tank 1 supplying ammonia to the engine 9 through a first air intake pipe 23, a heating mechanism and a buffer tank 13 sequentially provided on the first air intake pipe 23 along the ammonia flow direction, and the ammonia flows out from the heating mechanism and enters the buffer tank 13, and then flows out from the buffer tank 13 and enters the engine 9, and a flow control component is also provided on the first air intake pipe 23; The heating mechanism includes an electric heating component disposed on the first intake pipe 23, the electric heating component being connected to a first heat exchange component, and the first heat exchange component being provided with a heat exchange flow channel for the coolant of the engine 9 to flow through. A second temperature / pressure sensor 21 is provided at one end of the first intake pipe 23 near the engine 9. The second temperature / pressure sensor 21 is used to obtain the temperature and pressure of ammonia at the outlet of the first intake pipe 23. The second temperature / pressure sensor 21 is connected to the front controller 10. The front controller 10 is electrically connected to the pressure regulating mechanism, the electric heating component, the buffer tank 13, and the flow control component.

[0020] Liquid ammonia in the liquid ammonia storage tank 1 flows to the heating mechanism via the first intake pipe 23. The electric heating element in the heating mechanism heats the liquid ammonia, causing it to vaporize. Simultaneously, the engine coolant flowing through the first heat exchange component provides additional heat for the vaporization process. The vaporized gaseous ammonia enters the buffer tank 13 for buffering and flow stabilization. After being regulated by the flow control component, it enters the engine 9 from the outlet of the first intake pipe 23. The second temperature / pressure sensor 21 acquires the temperature and pressure of the ammonia at the outlet of the first intake pipe 23 in real time and feeds it back to the front controller 10. The front controller 10 then coordinates the control of the pressure regulation mechanism, the electric heating element, the buffer tank 13, and the flow control component. Utilizing the waste heat of the engine coolant to assist in the vaporization of liquid ammonia reduces dependence on external electrical energy. Simultaneously, real-time temperature and pressure feedback and closed-loop control ensure a stable ammonia state at the outlet, preventing supply interruptions.

[0021] Further optimization of the scheme: the flow control component includes a manual valve 2, a flow valve 3, a shut-off valve 4, a first pressure regulating valve 5, and a first flow meter 6 arranged sequentially along the ammonia flow direction on the first intake pipe 23. The manual valve 2 and the flow valve 3 are located upstream of the electric heating component, the shut-off valve 4 is located between the buffer tank 13 and the electric heating component, and the first pressure regulating valve 5 is located downstream of the buffer tank 13. The flow valve 3, the shut-off valve 4, the first pressure regulating valve 5, and the first flow meter 6 are all connected to the front controller 10 via signal.

[0022] Along the ammonia flow direction, liquid ammonia first enters the heating assembly via manual valve 2 and flow valve 3. Manual valve 2 allows for manual shut-off of the liquid supply in emergency situations, while flow valve 3 adjusts the liquid ammonia supply based on signals from the front controller 10. After vaporizing into gaseous ammonia, the liquid ammonia enters the buffer tank 13 via shut-off valve 4, which is controlled by the front controller 10. Gaseous ammonia flows out of the buffer tank 13, is pressure-reduced and stabilized by the first pressure regulating valve 5, and then metered by the first flow meter 6 before being supplied to the engine 9. Flow valve 3, shut-off valve 4, the first pressure regulating valve 5, and the first flow meter 6 are all controlled by signals from the front controller 10, ensuring precise regulation of the ammonia supply, pressure, and on / off status throughout the pipeline, thus guaranteeing stable operation of the supply system.

[0023] The scheme is further optimized. The pressure regulating mechanism includes a partition 27 installed inside the liquid ammonia storage tank 1. The partition 27 divides the inner cavity of the liquid ammonia storage tank 1 into a pressure control cavity and a liquid ammonia storage cavity. The partition 27 is slidably installed along the length of the liquid ammonia storage tank 1. A through hole is opened on the partition 27. An elastic diaphragm 28 is fixedly connected to the through hole. A displacement sensor is installed between the partition 27 and the liquid ammonia storage tank 1. A deformation sensor is installed on the elastic diaphragm 28. The pressure control chamber is connected to an air pump 12, and a pressure valve 11 is installed between the air pump 12 and the pressure control chamber. The air pump 12, the pressure valve 11, the displacement sensor, and the deformation sensor are all connected to the front controller 10 via signal.

[0024] When the pressure regulating mechanism is working, the baffle 27 divides the inner cavity of the liquid ammonia storage tank 1 into a pressure control chamber and a liquid ammonia storage chamber. A displacement sensor monitors the position of the baffle 27 in real time, and a deformation sensor monitors the deformation of the elastic diaphragm 28 in real time, transmitting the signals to the front controller 10. Based on the signals and operating conditions, the front controller 10 controls the air pump 12 to deliver compressed air to the pressure control chamber, and the pressure is adjusted by the pressure valve 11, causing the baffle 27 to move and regulate the pressure in the liquid ammonia storage chamber. The elastic diaphragm 28 rapidly absorbs transient pressure fluctuations at the through-hole through elastic deformation. This mechanism achieves active regulation of the internal pressure of the liquid ammonia storage tank 1 and passive absorption of transient fluctuations, ensuring that the liquid ammonia maintains sufficient pressure in the liquid phase pipeline to prevent premature vaporization or pipeline air resistance.

[0025] Further optimization of the scheme: the electric heating component includes a heater 15 installed on the first air intake pipe 23, the heater 15 is electrically connected to the power supply 14, and the heater 15 is signal connected to the front controller 10; The first heat exchange assembly includes a heat exchanger disposed on the engine 9 and a first heat exchange pipe 25 connected to the heat exchanger. The first heat exchange pipe 25 is connected to a heater 15 for circulating coolant between the heat exchanger and the heater 15.

[0026] The electric heating component works in conjunction with the first heat exchange component. The high-temperature coolant generated by the engine 9 enters the heater 15 through the first heat exchange pipe 25, where it, together with the electric heating component, provides heat for the vaporization of liquid ammonia. The front controller 10 adjusts the power supply from the power source 14 to the heater 15 according to the engine coolant temperature and operating conditions, thus achieving heat distribution between electric heating and hydrothermal heating. This structure allows the liquid ammonia vaporization process to be completed independently by electric heating during the initial stage of engine startup, and then switches to the residual heat of the coolant as the primary energy source after the engine has warmed up, thereby reducing the overall power consumption of the system.

[0027] In a further optimized design, an ammonia injection nozzle 7 is installed at the outlet of the first air intake pipe 23. The outlet of the ammonia injection nozzle 7 is connected to the mixing tank 8. The mixing tank 8 is equipped with an air inlet and a mixed gas outlet. The mixed gas outlet of the mixing tank 8 is connected to the air intake of the engine 9.

[0028] Gaseous ammonia is injected into the mixing tank 8 through the ammonia nozzle 7 at the outlet of the first intake pipe 23. Simultaneously, external air enters the mixing tank 8 through the air inlet. After the ammonia and air are fully mixed in the mixing tank 8, the resulting mixture is sent into the cylinder from the mixture outlet through the intake end of the engine 9. This structure achieves pre-mixing of ammonia and air before they enter the cylinder, making the mixture more uniform and improving the combustion efficiency and stability of the engine 9.

[0029] In a further optimized design, the first intake pipe 23 is connected to the second intake pipe 24. The connection between the second intake pipe 24 and the first intake pipe 23 is located between the buffer tank 13 and the first pressure regulating valve 5. The second intake pipe 24 is sequentially equipped with a second pressure regulating valve 18 and a second flow meter 19 along the ammonia flow direction. The outlet of the second intake pipe 24 is connected to the SCR 22 through another ammonia injection nozzle 7. The SCR 22 is connected to the outlet of the engine 9. The SCR 22, the second pressure regulating valve 18, and the second flow meter 19 are all signal-connected to the aftertreatment controller 17.

[0030] A portion of the gaseous ammonia from buffer tank 13 is diverted through the second intake pipe 24, then sequentially reduced in pressure by the second pressure regulating valve 18, metered by the second flow meter 19, and finally injected into the SCR 22 via another ammonia injection nozzle 7 as a reducing agent. The second pressure regulating valve 18, the second flow meter 19, and the SCR 22 are all connected to the aftertreatment controller 17. The aftertreatment controller 17 calculates the ammonia demand based on the exhaust emission data from engine 9 and sends adjustment signals to the second pressure regulating valve 18 and the second flow meter 19. This structure utilizes ammonia fuel itself as the reducing agent for the SCR 22, replacing the traditional urea supply device and simplifying the aftertreatment system structure.

[0031] The scheme is further optimized by installing water jackets on the outside of the first air intake pipe 23 and the second air intake pipe 24, and installing a second heat exchange pipe 26 on the buffer tank 13. Both the water jacket and the second heat exchange pipe 26 are connected to the heat exchanger.

[0032] The water jackets outside the first intake pipe 23 and the second intake pipe 24, as well as the second heat exchange pipe 26 on the buffer tank 13, are all connected to the heat exchanger on the engine 9. The high-temperature coolant of the engine 9 enters the water jacket and the second heat exchange pipe 26 through the heat exchanger to heat and insulate the ammonia gas in the first intake pipe 23, the second intake pipe 24, and the buffer tank 13. This structure effectively prevents the ammonia gas from liquefying in the pipes and the buffer tank 13 due to pressure fluctuations under low-temperature conditions, ensuring that the ammonia gas in the gas phase pipes is always maintained in a gaseous state.

[0033] In a further optimized design, the front controller 10 is connected to an ammonia sensor 16, which is used to detect ammonia leaks.

[0034] The ammonia sensor 16 monitors the ammonia concentration in the engine room and around the fuel supply system in real time and transmits the detection signal to the front controller 10. When the front controller 10 determines that the ammonia concentration exceeds the safety threshold, it issues an alarm or performs a shut-off protection action. This structure enables real-time monitoring of ammonia leakage in the system, ensuring the safety of the vehicle and personnel.

[0035] The scheme has been further optimized by installing a first temperature / pressure sensor 20 inside the mixing tank 8, which is connected to the front controller 10 via a signal.

[0036] The first temperature / pressure sensor 20 acquires the temperature and pressure signals of ammonia in the mixing tank 8 in real time and transmits them to the front controller 10. The front controller 10 dynamically adjusts the power of the heater 15, the opening of the flow valve 3, and the output of the pressure regulating mechanism to ensure that the ammonia in the mixing tank 8 is always in the optimal supply range, thus ensuring the stability of the air-fuel mixture entering the engine 9.

[0037] A method for supplying gaseous ammonia fuel to a vehicle ammonia engine, based on a gaseous ammonia fuel supply device for a vehicle ammonia engine, includes the following steps: The front controller 10 acquires the temperature and pressure of ammonia at the outlet of the first inlet pipe 23 and the temperature and pressure of ammonia in the buffer tank 13. Based on the temperature and pressure of ammonia at the outlet of the first inlet pipe 23, it acquires the saturated vapor pressure and density of ammonia at the current temperature. It compares the internal pressure of the liquid ammonia storage tank 1 with the saturated vapor pressure of ammonia at the current temperature. When the internal pressure of the liquid ammonia storage tank 1 is less than the saturated vapor pressure, it controls the pressure regulating mechanism to increase the internal pressure of the liquid ammonia storage tank 1. The coolant temperature of engine 9 is obtained, and when the coolant temperature reaches a preset threshold, the heating power of the electric heating component is controlled to decrease as the coolant temperature increases. The mass flow rate of ammonia is calculated based on the density of ammonia and the cross-sectional area of ​​the outlet end of the first intake pipe 23. The ammonia demand is determined based on the mass flow rate and the instantaneous operating conditions of the engine 9, and a flow adjustment signal corresponding to the ammonia demand is sent to the flow control component. The pressure of ammonia in buffer tank 13 is compared with the saturated vapor pressure of ammonia at the current temperature. When the pressure in buffer tank 13 is close to the saturated vapor pressure, the flow control component is controlled to reduce the liquid ammonia supply and the electric heating component is controlled to increase the heating power, so that the temperature of the downstream pipeline of the heating mechanism and the buffer tank 13 increases and the pressure decreases.

[0038] Liquid ammonia is stored in the liquid ammonia storage chamber of liquid ammonia storage tank 1. The front controller 10 acquires the position signal of the baffle 27 within liquid ammonia storage tank 1 in real time via a displacement sensor and the deformation signal of the elastic diaphragm 28 in real time via a deformation sensor. Based on these signals and current operating conditions, the front controller 10 sends control signals to the air pump 12 and pressure valve 11. The air pump 12 supplies compressed air into the pressure control chamber of liquid ammonia storage tank 1, and the pressure valve 11 adjusts the air pressure supplied into the pressure control chamber, pushing the baffle 27 to move along its length within liquid ammonia storage tank 1, thereby regulating the internal pressure of the liquid ammonia storage chamber. The elastic diaphragm 28 rapidly absorbs transient pressure fluctuations within the liquid ammonia storage chamber through elastic deformation at the through-hole. The pressure regulation range inside liquid ammonia storage tank 1 is set as needed to ensure that the liquid ammonia maintains sufficient pressure in the liquid phase section of the first air inlet pipe 23 to prevent premature vaporization.

[0039] Liquid ammonia in the liquid ammonia storage tank 1 flows out from the liquid ammonia storage chamber under pressure, and flows sequentially through the first air inlet pipe 23, passing through the manual valve 2 and the flow valve 3. The manual valve 2 remains open under normal operating conditions and is manually closed by the operator in an emergency to cut off the liquid supply. The flow valve 3 regulates the supply of liquid ammonia according to the flow regulation signal sent by the front controller 10. The liquid ammonia then enters the heater 15. Inside the heater 15, the liquid ammonia receives heat from both the electric heating component and the first heat exchange component: the power supply 14 converts electrical energy into heat energy at the heater 15 to electrically heat the liquid ammonia; simultaneously, the high-temperature coolant generated by the engine 9 enters the heater 15 through the first heat exchange pipe 25, exchanges heat with the heater 15 in the heat exchange channel, and transfers the heat of the coolant to the liquid ammonia. After absorbing the aforementioned heat in the heater 15, the liquid ammonia vaporizes into gaseous ammonia.

[0040] The front controller 10 adjusts the electric heating power according to the operating status of the engine 9. Before the engine 9 starts and during the warm-up period, the coolant temperature of the engine 9 has not yet reached the preset threshold. The front controller 10 controls the power supply 14 to provide the rated electric heating power to the heater 15, and the electric heating component independently completes the vaporization energy supply of liquid ammonia. The front controller 10 continuously acquires the coolant temperature signal of the engine 9. When the coolant temperature reaches the preset threshold, the front controller 10 controls the heating power of the electric heating component to gradually decrease as the coolant temperature rises. At the same time, the high-temperature coolant in the first heat exchange pipe 25 continuously supplies heat to the heater 15, so that the source of vaporization heat gradually switches from electric heating to the waste heat of the coolant.

[0041] Gaseous ammonia flows out of heater 15 and enters buffer tank 13 via shut-off valve 4. Shut-off valve 4 is controlled by front controller 10 and closes when gas supply needs to be interrupted. Gaseous ammonia is buffered and its flow is stabilized in buffer tank 13. The gaseous ammonia in buffer tank 13 is heated by the high-temperature coolant of engine 9 through second heat exchange pipe 26 to prevent the ammonia in buffer tank 13 from liquefying due to excessively low temperature. The gaseous ammonia in buffer tank 13 then flows out of buffer tank 13, is depressurized and stabilized by first pressure regulating valve 5, and continues to flow towards engine 9 along first intake pipe 23 after being measured by first flow meter 6.

[0042] The first flow meter 6 feeds back the real-time metering signal to the front controller 10. The front controller 10 also acquires the temperature and pressure of ammonia at the outlet of the first intake pipe 23 in real time via the second temperature / pressure sensor 21, and obtains the saturated vapor pressure and density of ammonia at the current temperature based on this temperature and pressure. The front controller 10 compares the internal pressure of the liquid ammonia storage tank 1 with the saturated vapor pressure of ammonia at the current temperature. When the internal pressure of the liquid ammonia storage tank 1 is less than the saturated vapor pressure, the front controller 10 controls the air pump 12 and pressure valve 11 to increase the internal pressure of the liquid ammonia storage tank 1, ensuring that the ammonia in the liquid phase pipeline remains liquid. The front controller 10 also calculates the mass flow rate of ammonia based on the density of ammonia and the cross-sectional area of ​​the outlet of the first intake pipe 23, and determines the ammonia demand based on the mass flow rate and the instantaneous operating conditions of the engine 9, sending a flow regulation signal corresponding to the ammonia demand to the flow valve 3.

[0043] Gaseous ammonia flows through the first intake pipe 23 to the ammonia injection nozzle 7 at the outlet, and is injected into the mixing tank 8 through the nozzle 7. Simultaneously, external air enters the mixing tank 8 through the air inlet. The ammonia and air mix thoroughly in the mixing tank 8 to form a mixture, which flows out from the mixture outlet of the mixing tank 8 and is then fed into the cylinder of the engine 9 for combustion. The first temperature / pressure sensor 20 acquires the temperature and pressure signals of the ammonia in the mixing tank 8 in real time and transmits them to the front controller 10. Based on this, the front controller 10 dynamically adjusts the heating power of the heater 15, the opening degree of the flow valve 3, and the output of the pressure regulating mechanism to ensure that the ammonia in the mixing tank 8 remains within the preset supply range.

[0044] During the transport of gaseous ammonia along the first intake pipe 23, the front controller 10 also compares the pressure of ammonia in the buffer tank 13 with the saturated vapor pressure of ammonia at the current temperature using the second temperature / pressure sensor 21. When the pressure in the buffer tank 13 approaches the saturated vapor pressure, the front controller 10 sends a control signal to the flow valve 3 to reduce the liquid ammonia supply, and simultaneously sends a control signal to the power supply 14 to increase the heating power of the electric heating component, thereby increasing the temperature and decreasing the pressure in the downstream pipe of the heating mechanism and in the buffer tank 13, ensuring that the ammonia in the gas phase section of the first intake pipe 23 from the buffer tank 13 to the engine 9 remains in a gaseous state.

[0045] A portion of the gaseous ammonia from the buffer tank 13 is diverted through the second intake pipe 24, and after being reduced in pressure by the second pressure regulating valve 18 and measured by the second flow meter 19, it is injected into the SCR 22 through another ammonia injection nozzle 7. The aftertreatment controller 17 collects exhaust emission data from the engine 9, calculates the ammonia demand based on the nitrogen oxide concentration in the emissions, and sends adjustment signals to the second pressure regulating valve 18 and the second flow meter 19 to control the amount of ammonia injected into the SCR 22, using ammonia as a reducing agent to treat the nitrogen oxides in the exhaust gas.

[0046] During the delivery of ammonia through the first intake pipe 23 and the second intake pipe 24, the high-temperature coolant of the engine 9 enters the water jacket outside the first intake pipe 23 and the second intake pipe 24, as well as the second heat exchange pipe 26 on the buffer tank 13, via a heat exchanger. This heats the ammonia in the first intake pipe 23, the second intake pipe 24, and the buffer tank 13, preventing the ammonia from liquefying due to pressure fluctuations in the pipes at low temperatures. The front controller 10 dynamically adjusts the coolant flow distribution ratio of the first heat exchange pipe 25 and the second heat exchange pipe 26 based on multiple parameters such as ambient temperature, engine 9 load, and ammonia temperature in the buffer tank 13. When the ammonia temperature in the pipe is detected to be close to the saturation point, the flow rate of the second heat exchange pipe 26 is automatically increased to enhance pipe insulation.

[0047] Ammonia sensor 16 monitors the ammonia concentration in the engine compartment and around the fuel supply system of engine 9 in real time and transmits the detection signal to the front controller 10. When the front controller 10 determines that the ammonia concentration exceeds the safety threshold, it issues an alarm signal and controls the flow valve 3 and the shut-off valve 4 to perform a shut-off protection action.

[0048] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to 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.

[0049] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A gaseous ammonia fuel supply device for a vehicle ammonia engine, characterized in that, include: A liquid ammonia storage tank (1) is provided with a pressure regulating mechanism. The liquid ammonia storage tank (1) supplies ammonia to the engine (9) through a first air intake pipe (23). A heating mechanism and a buffer tank (13) are sequentially arranged on the first air intake pipe (23) along the ammonia flow direction. Ammonia flows out from the heating mechanism and enters the buffer tank (13), and then flows out from the buffer tank (13) and enters the engine (9). A flow control component is also provided on the first air intake pipe (23). The heating mechanism includes an electric heating component disposed on the first intake pipe (23), the electric heating component is connected to a first heat exchange component, and the first heat exchange component is provided with a heat exchange channel for the coolant of the engine (9) to flow through; A second temperature / pressure sensor (21) is provided at one end of the first intake pipe (23) near the engine (9). The second temperature / pressure sensor (21) is used to obtain the temperature and pressure of ammonia at the outlet of the first intake pipe (23). The second temperature / pressure sensor (21) is connected to the front controller (10). The front controller (10) is electrically connected to the pressure regulating mechanism, the electric heating component, the buffer tank (13), and the flow control component.

2. The ammonia fuel supply device for a vehicle ammonia engine according to claim 1, characterized in that: The flow control assembly includes a manual valve (2), a flow valve (3), a shut-off valve (4), a first pressure regulating valve (5), and a first flow meter (6) arranged sequentially along the ammonia flow direction on the first air inlet pipe (23). The manual valve (2) and the flow valve (3) are located upstream of the electric heating assembly, the shut-off valve (4) is located between the buffer tank (13) and the electric heating assembly, and the first pressure regulating valve (5) is located downstream of the buffer tank (13). The flow valve (3), the shut-off valve (4), the first pressure regulating valve (5), and the first flow meter (6) are all connected to the front controller (10) via signal connection.

3. The ammonia fuel supply device for a vehicle ammonia engine according to claim 1, characterized in that: The pressure regulating mechanism includes a partition (27) disposed inside the liquid ammonia storage tank (1). The partition (27) divides the inner cavity of the liquid ammonia storage tank (1) into a pressure control chamber and a liquid ammonia storage chamber. The partition (27) is slidably disposed along the length direction of the liquid ammonia storage tank (1). A through hole is provided on the partition (27). An elastic diaphragm (28) is fixedly connected to the through hole. A displacement sensor is disposed between the partition (27) and the liquid ammonia storage tank (1). A deformation sensor is disposed on the elastic diaphragm (28). The pressure control chamber is connected to an air pump (12), and a pressure valve (11) is provided between the air pump (12) and the pressure control chamber. The air pump (12), the pressure valve (11), the displacement sensor, and the deformation sensor are all connected to the front controller (10) via signal.

4. The ammonia fuel supply device for a vehicle ammonia engine according to claim 2, characterized in that: The electric heating assembly includes a heater (15) disposed on the first air intake pipe (23), the heater (15) being electrically connected to a power supply (14), and the heater (15) being signal connected to the front controller (10); The first heat exchange assembly includes a heat exchanger disposed on the engine (9) and a first heat exchange pipeline (25) connected to the heat exchanger. The first heat exchange pipeline (25) is connected to the heater (15) for circulating coolant between the heat exchanger and the heater (15).

5. The ammonia fuel supply device for a vehicle ammonia engine according to claim 4, characterized in that: The first intake pipe (23) is provided with an ammonia nozzle (7) at the outlet end. The outlet end of the ammonia nozzle (7) is connected to the mixing tank (8). The mixing tank (8) is provided with an air inlet and a mixed gas outlet. The mixed gas outlet of the mixing tank (8) is connected to the intake end of the engine (9).

6. The ammonia fuel supply device for a vehicle ammonia engine according to claim 5, characterized in that: The first intake pipe (23) is connected to the second intake pipe (24). The connection between the second intake pipe (24) and the first intake pipe (23) is located between the buffer tank (13) and the first pressure regulating valve (5). The second intake pipe (24) is sequentially provided with a second pressure regulating valve (18) and a second flow meter (19) along the ammonia flow direction. The outlet of the second intake pipe (24) is connected to the SCR (22) through another ammonia injection nozzle (7). The SCR (22) is connected to the outlet of the engine (9). The SCR (22), the second pressure regulating valve (18), and the second flow meter (19) are all connected to the aftertreatment controller (17) via signal.

7. The ammonia fuel supply device for a vehicle ammonia engine according to claim 6, characterized in that: Water jackets are fitted on the outside of the first air inlet pipe (23) and the second air inlet pipe (24). A second heat exchange pipe (26) is provided on the buffer tank (13). The water jacket and the second heat exchange pipe (26) are connected to the heat exchanger.

8. The ammonia fuel supply device for a vehicle ammonia engine according to claim 1, characterized in that: The front controller (10) is connected to an ammonia sensor (16), which is used to detect ammonia leakage.

9. The ammonia fuel supply device for a vehicle ammonia engine according to claim 5, characterized in that: The mixing tank (8) is equipped with a first temperature / pressure sensor (20), which is connected to the front controller (10) via signal.

10. A method for supplying gaseous ammonia fuel to a vehicle ammonia engine, based on the gaseous ammonia fuel supply device for a vehicle ammonia engine according to any one of claims 1-9, characterized in that, Includes the following steps: The front controller (10) obtains the temperature and pressure of ammonia at the outlet of the first inlet pipe (23) and the temperature and pressure of ammonia in the buffer tank (13). Based on the temperature and pressure of ammonia at the outlet of the first inlet pipe (23), it obtains the saturated vapor pressure and density of ammonia at the current temperature. It compares the internal pressure of the liquid ammonia storage tank (1) with the saturated vapor pressure of ammonia at the current temperature. When the internal pressure of the liquid ammonia storage tank (1) is less than the saturated vapor pressure, it controls the pressure regulating mechanism to increase the internal pressure of the liquid ammonia storage tank (1). The engine (9) coolant temperature is obtained, and when the coolant temperature reaches a preset threshold, the heating power of the electric heating component is controlled to decrease as the coolant temperature increases. The mass flow rate of ammonia is calculated based on the density of ammonia and the cross-sectional area of ​​the outlet end of the first intake pipe (23), and the ammonia demand is determined according to the mass flow rate and the instantaneous operating conditions of the engine (9), and a flow adjustment signal corresponding to the ammonia demand is sent to the flow control component. The pressure of ammonia in the buffer tank (13) is compared with the saturated vapor pressure of ammonia at the current temperature. When the pressure in the buffer tank (13) is close to the saturated vapor pressure, the flow control component is controlled to reduce the liquid ammonia supply and the electric heating component is controlled to increase the heating power, so that the temperature of the downstream pipeline of the heating mechanism and the buffer tank (13) increases and the pressure decreases.

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