Ammonia hydrogen engine device based on ammonia gas composite injection

Abstract

The utility model discloses an ammonia hydrogen engine device based on ammonia gas composite injection. The ammonia hydrogen engine device comprises an engine cylinder; the in-cylinder direct injection liquid ammonia injector is connected with the cylinder body end of the engine cylinder; the manifold hydrogen injector is arranged on an air inlet pipe connected with the engine air cylinder; the manifold ammonia gas ejector is arranged on an air inlet pipe connected with the engine air cylinder; a high-pressure hydrogen gas tank connected to the manifold hydrogen gas injector and used for supplying hydrogen gas; and the ammonia storage tank is connected with the manifold ammonia gas ejector and the in-cylinder direct injection liquid ammonia ejector and is used for supplying ammonia. According to the ammonia hydrogen engine device based on ammonia gas composite injection, high-power output of the engine under different working conditions can be achieved, abnormal combustion is avoided, and zero carbon emission of the engine is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of engine technology, and specifically relates to an ammonia-hydrogen engine device based on ammonia gas composite injection. Background Technology

[0002] Currently, the vast majority of vehicles use traditional fossil fuels produced through mature technologies. Because fossil fuels account for a large proportion of primary energy consumption, they are insufficient to meet the requirements of the "dual-carbon" strategy. Therefore, to reduce carbon emissions in the vehicle sector and achieve the goal of "carbon neutrality" as soon as possible, engines must be able to burn carbon-neutral or zero-carbon fuels in the future. Currently, mainstream alternative fuels include hydrogen, ammonia, methanol, ethanol, biodiesel, and natural gas. Among these, carbon-neutral fuels can achieve low carbon emissions throughout their entire lifecycle, from production to combustion, without emitting large amounts of additional CO2. Zero-carbon fuels eliminate carbon emissions at their very source. When engines use carbon-neutral or zero-carbon fuels as their power source, their operation can achieve carbon balance or even net-zero emissions, thus completing a significant transition from traditional power to clean power. Although carbon-neutral fuels can achieve low carbon emissions throughout their entire lifecycle, they are still carbon-based fuels and will still emit a small amount of CO2 during combustion. Therefore, to achieve the goal of completely zero carbon emissions, it is essential to develop and reveal the combustion control technology based on ammonia-hydrogen zero-carbon fuels.

[0003] Hydrogen, as a mainstream zero-carbon fuel currently under research, possesses characteristics such as high calorific value, fast combustion speed, strong diffusivity, and a wide combustible range. Compared to traditional gasoline, hydrogen exhibits faster laminar flame combustion and a combustion process closer to isochoric combustion, resulting in significantly improved combustion efficiency. Chemically, hydrogen combustion in air produces only water, with no CO2 emissions. Furthermore, the rapid development of photovoltaic power generation technology has drastically reduced the cost of producing hydrogen through water electrolysis, thus fulfilling the basic requirements for a zero-carbon fuel. However, hydrogen molecules are small, have low volumetric energy density, are difficult to liquefy, and pose risks of explosion and leakage. Regarding hydrogen storage, the most mature technologies currently are cryogenic hydrogen storage and compressed hydrogen storage. However, cryogenic hydrogen storage has poor energy efficiency, while compressed hydrogen storage requires a large storage volume due to hydrogen's low density. Therefore, both methods have drawbacks in terms of energy efficiency and compression volume requirements, and their feasibility requires further verification. Thus, hydrogen is unlikely to be directly used as a vehicle fuel in the short term.

[0004] Unlike hydrogen, which is primarily produced through water electrolysis, ammonia has a wider range of sources. Currently, global annual ammonia production exceeds 200 million tons, the vast majority of which comes from industrial ammonia production, specifically the synthesis of nitrogen and hydrogen using the Haber-Bosch process. This process is mature, and the ammonia production and transportation supply chain is well-established. Although ammonia fuel has a relatively low mass calorific value, its theoretically low air requirement allows the calorific value of the mixture to remain at a high level. Therefore, ammonia has the potential to be used directly as engine fuel. However, due to its stable chemical properties, strong combustion inertness, and difficulty in direct ignition in air, coupled with its slow laminar flame combustion speed and narrow flammability limit, the current mainstream approach is to couple ammonia with other highly reactive fuels. Considering that ammonia easily decomposes into hydrogen at high temperatures, the ammonia-hydrogen dual-fuel combustion mode, which uses a small amount of hydrogen to increase the cylinder temperature and pressure and then ignites the remaining ammonia, has become one of the main research directions for ammonia fuel. This combustion scheme fully utilizes the stable chemical properties and easy storage and transportation of ammonia, treating it as a good hydrogen storage medium. Its combustion products are only nitrogen and water, and it realizes the utilization and development of two zero-carbon energy sources, ammonia and hydrogen, with very broad application prospects. Summary of the Invention

[0005] The purpose of this invention is to provide an ammonia-hydrogen engine device based on ammonia gas composite injection, which can achieve high power output of the engine under different operating conditions, avoid abnormal combustion, and achieve zero carbon emissions from the engine.

[0006] The technical solution provided by this utility model is as follows:

[0007] An ammonia-hydrogen engine device based on ammonia gas composite injection, comprising:

[0008] Engine cylinders;

[0009] An in-cylinder direct injection liquid ammonia injector is connected to the cylinder block end of the engine cylinder;

[0010] A manifold hydrogen injector, which is mounted on the intake manifold connected to the engine cylinder;

[0011] A manifold ammonia injector is installed on the intake manifold connected to the engine cylinder;

[0012] A high-pressure hydrogen tank, connected to the manifold hydrogen injector, is used to supply hydrogen.

[0013] An ammonia storage tank, which is connected to the manifold ammonia injector and the in-cylinder direct-injection liquid ammonia injector, is used to supply ammonia.

[0014] Preferably, a hydrogen pressure reducing valve and a hydrogen flow sensor are provided between the high-pressure hydrogen tank and the manifold hydrogen injector.

[0015] Preferably, a liquid ammonia vaporizer, an ammonia pressure reducing valve, and an ammonia flow sensor are provided between the ammonia storage tank and the manifold ammonia injector.

[0016] Preferably, a liquid ammonia compressor, a liquid ammonia shut-off valve, and a liquid ammonia flow sensor are provided between the ammonia storage tank and the in-cylinder direct injection liquid ammonia injector.

[0017] Preferably, it also includes: an ammonia storage tank temperature sensor and an ammonia storage tank pressure sensor, both of which are installed on the ammonia storage tank.

[0018] Preferably, it further includes: an electronic control unit connected to the hydrogen pressure reducing valve, the hydrogen flow sensor, the manifold hydrogen injector, the ammonia pressure reducing valve, the ammonia flow sensor, the manifold ammonia injector, the liquid ammonia shut-off valve, the liquid ammonia flow sensor, the in-cylinder direct injection liquid ammonia injector, the ammonia storage tank temperature sensor, and the ammonia storage tank pressure sensor.

[0019] The beneficial effects of this utility model are:

[0020] The ammonia-hydrogen engine device based on ammonia-gas composite injection provided by this utility model adopts a dual-path ammonia supply structure with direct liquid ammonia injection in the cylinder and ammonia gas injection through the air intake. Direct liquid ammonia injection improves power density, while ammonia gas injection improves mixing uniformity, adapting to all operating conditions. Hydrogen-assisted injection is used to ignite the ammonia gas, solving the problem of difficult ammonia fuel ignition. The combustion products of ammonia-hydrogen fuel are only nitrogen and water, eliminating carbon dioxide emissions at the source and ensuring zero carbon emissions. It achieves high power output of the engine under different operating conditions and avoids abnormal combustion. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the ammonia-hydrogen engine device based on ammonia gas composite injection as described in this utility model.

[0022] Figure 2 This is a schematic flowchart of the control method for the ammonia-hydrogen engine device based on ammonia gas composite injection as described in this utility model.

[0023] Figure 3 This is a schematic diagram showing the correspondence between the internal pressure of the ammonia storage tank and the injection strategy described in this utility model.

[0024] Reference numerals: Engine cylinder 110, piston 111, cylinder block end 112, combustion chamber 113, spark plug 120, camshaft position sensor 130, crankshaft position sensor 140, connecting rod 150, intake manifold 210, intake valve 211, air filter 220, electronic throttle 230, air flow sensor 240, manifold pressure sensor 250, exhaust manifold 260, exhaust valve 261, oxygen sensor 270, high-pressure hydrogen tank 310 Hydrogen pressure reducing valve 320, hydrogen flow sensor 330, manifold hydrogen injector 340, ammonia storage tank 410, ammonia storage tank temperature sensor 411, ammonia storage tank pressure sensor 412, liquid ammonia vaporizer 421, ammonia pressure reducing valve 422, ammonia flow sensor 423, manifold ammonia injector 424, liquid ammonia compressor 431, liquid ammonia shut-off valve 432, liquid ammonia flow sensor 433, in-cylinder direct injection liquid ammonia injector 434, electronic control unit 510. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0026] like Figure 1 As shown, this utility model provides an ammonia-hydrogen engine device based on ammonia gas composite injection, which includes: an engine cylinder 110, an intake mechanism, an exhaust mechanism, a hydrogen supply mechanism, an ammonia supply mechanism, and an electronic control system.

[0027] The engine cylinder 110 is a power supply mechanism for the engine; the engine cylinder 110 contains a piston 111 and a combustion chamber 113; the combustion chamber 113 is a cavity formed by the outer shell of the cylinder end 112 of the engine cylinder 110 and the piston 111, which serves as a space for fuel combustion.

[0028] The intake mechanism is connected to the cylinder block end 112 of the engine cylinder 110. The intake mechanism includes: an intake pipe 210, one end of which is connected to the cylinder block end 112 of the engine cylinder 110 and communicates with the combustion chamber 113; an air filter 220, an electronic throttle valve 230, an air flow sensor 240, and a manifold pressure sensor 250, which are arranged sequentially on the intake pipe 210; and an intake valve 211, which is located at the connection between the intake pipe 210 and the engine air connection and is used to control the isolation and communication between the intake pipe 210 and the combustion chamber 113.

[0029] The exhaust mechanism is connected to the cylinder block end 112 of the engine cylinder 110. The exhaust mechanism includes: an exhaust pipe 260, one end of which is connected to the cylinder block end 112 of the engine cylinder 110 and communicates with the combustion chamber 113; an oxygen sensor 270, which is disposed on the exhaust pipe 260; and an exhaust valve 261, which is disposed at the connection between the exhaust pipe 260 and the engine cylinder 110 and is used to control the isolation and communication between the exhaust pipe 260 and the combustion chamber 113.

[0030] The hydrogen supply mechanism includes: a high-pressure hydrogen tank 310, which stores hydrogen through compression for supplying hydrogen; a manifold hydrogen injector 340, which is located at one end of the intake mechanism near the engine cylinder 110 and communicates with the interior of the intake pipe 210; wherein the high-pressure hydrogen tank 310 and the manifold hydrogen injector 340 are connected by a pipeline; a hydrogen pressure reducing valve 320, which is located between the high-pressure hydrogen tank 310 and the manifold hydrogen injector 340; and a hydrogen flow sensor 330, which is located between the hydrogen pressure reducing valve 320 and the manifold hydrogen injector 340; the high-pressure hydrogen tank 310, the hydrogen pressure reducing valve 320, the hydrogen flow sensor 330, and the manifold hydrogen injector 340 are all connected by pipelines.

[0031] The ammonia supply mechanism includes: an ammonia storage tank 410, which contains liquid ammonia and ammonia gas. The ammonia storage tank 410 is connected to a manifold ammonia gas injector 424 and an in-cylinder direct injection liquid ammonia injector 434 respectively through pipelines for supplying ammonia. The ammonia storage tank 410 is equipped with an ammonia storage tank temperature sensor 411 and an ammonia storage tank pressure sensor 412 for monitoring the temperature, pressure and ammonia status inside the ammonia storage tank 410. Two pipelines are provided between the ammonia storage tank 410 and the engine cylinder 110, one for ammonia gas and the other for liquid ammonia. The ammonia pipeline includes: a manifold ammonia injector 424, which is disposed at one end of the intake mechanism near the engine cylinder 110 and communicates with the interior of the intake pipe 210; a liquid ammonia vaporizer 421, which is disposed between the ammonia storage tank 410 and the manifold ammonia injector 424; an ammonia pressure reducing valve 422, which is disposed between the liquid ammonia vaporizer 421 and the manifold ammonia injector 424; and an ammonia flow sensor 423, which is disposed between the ammonia pressure reducing valve 422 and the manifold ammonia injector 424. The liquid ammonia pipeline includes: an in-cylinder direct injection liquid ammonia injector 434, which is connected to the cylinder block end 112 of the engine cylinder 110 and communicates with the combustion chamber 113; a liquid ammonia compressor 431, which is disposed between the ammonia storage tank 410 and the in-cylinder direct injection liquid ammonia injector 434; the liquid ammonia compressor 431 is driven by the engine via a belt, which has excellent damping torque and overload protection capabilities, and can overcome problems such as large engine torque fluctuations and resistance fluctuations encountered by the compressor during startup and operation, thereby greatly extending the life of the engine and compressor bearings. Moreover, it is low in cost and simple to maintain. Currently, most automotive power equipment (such as automotive air conditioning compressors) uses belt drive, which is a mature and reliable technology; a liquid ammonia shut-off valve 432, which is disposed between the liquid ammonia compressor 431 and the in-cylinder direct injection liquid ammonia injector 434; and a liquid ammonia flow sensor 433, which is disposed between the liquid ammonia shut-off valve 432 and the in-cylinder direct injection liquid ammonia injector 434.

[0032] The electronic control system includes an electronic control unit 510 (ECU).

[0033] The ammonia-hydrogen engine device based on ammonia-gas composite injection further includes: a crankshaft, which is connected to the piston 111 inside the engine cylinder 110 via a connecting rod 150; the crankshaft is equipped with a crankshaft position sensor 140 and a speed sensor; a camshaft, which is connected to the crankshaft via a transmission mechanism for transmission; the camshaft is equipped with a camshaft position sensor 130; wherein, the transmission mechanism adopts a gear transmission mechanism, a chain transmission mechanism, or a belt transmission mechanism; the camshaft is also connected to the intake valve 211 and the exhaust valve 261 to control the opening and closing states of the intake valve 211 and the exhaust valve 261, ensuring the intake of air and fuel and the discharge of exhaust gas; a spark plug 120, which is connected to the cylinder block end 112 of the engine cylinder 110 and communicates with the combustion chamber 113 for igniting fuel; the spark plug 120 is disposed between the intake mechanism and the exhaust mechanism. The electronic control unit 510 is connected to the electronic throttle valve 230, the air flow sensor 240, the manifold pressure sensor 250, the spark plug 120, the oxygen sensor 270, the crankshaft position sensor 140, the camshaft position sensor 130, the speed sensor, the hydrogen pressure reducing valve 320, the hydrogen flow sensor 330, the manifold hydrogen injector 340, the ammonia tank temperature sensor 411, the ammonia tank pressure sensor 412, the ammonia pressure reducing valve 422, the ammonia flow sensor 423, the manifold ammonia injector 424, the liquid ammonia shut-off valve 432, the liquid ammonia flow sensor 433, and the in-cylinder direct injection liquid ammonia injector 434 via wires to exchange signals and realize the coordinated control of each component by the ECU.The ECU is connected to the ammonia storage tank temperature sensor 411 and the ammonia storage tank pressure sensor 412. Based on the signals from the ammonia storage tank temperature sensor 411 and the ammonia storage tank pressure sensor 412, the ECU monitors and determines the real-time status of the ammonia in the ammonia storage tank 410 during engine operation, providing reference data for selecting the ammonia supply strategy. The ECU is also connected to the electronic throttle valve 230 and the air flow sensor 240. The air flow sensor 240 monitors the air flow and feeds the signal back to the ECU. The ECU controls the opening of the electronic throttle valve 230 by issuing a control signal to the electronic throttle valve 230, thereby adjusting the amount of air entering the engine cylinder 110. The ECU is connected to the crankshaft position sensor 140 and the camshaft position sensor 130. Based on the signals from the crankshaft position sensor 140 and the camshaft position sensor 130, the ECU determines the engine speed and compression top dead center position, providing reference data for controlling the injection start time and pulse width of hydrogen and ammonia. The ECU is also connected to the manifold pressure sensor 250. Based on the output signal from the manifold pressure sensor 250, the ECU determines whether backfire has occurred. Finally, the ECU is connected to the spark plug 120. Based on the control signal from the electronic throttle valve 230, the signal from the crankshaft position sensor 140, and the signal from the camshaft position sensor 130, the ECU adjusts the ignition timing of the spark plug 120. The ECU is connected to the hydrogen pressure reducing valve 320. Based on the control signal from the electronic throttle valve 230, the ECU adjusts the hydrogen pressure reducing valve 320, thereby regulating the injection pressure of the manifold hydrogen injector 340. The ECU is also connected to the hydrogen flow sensor 330 and the manifold hydrogen injector 340. Based on the control signal from the electronic throttle valve 230 and the signal from the crankshaft position sensor 140, the ECU adjusts the injection timing and injection pulse width of the manifold hydrogen injector 340, and corrects this using the feedback signal from the hydrogen flow sensor 330 to ensure a stable excess air coefficient. Finally, the ECU is connected to the ammonia pressure reducing valve 422 or the liquid ammonia shut-off valve 432. The ECU adjusts the injection timing and injection pulse width of the manifold hydrogen injector 340 based on the engine operating conditions. Furthermore, the ammonia pressure reducing valve 422 or the liquid ammonia shut-off valve 432 is adjusted to regulate the injection pressure of the manifold ammonia injector 424 or the direct injection liquid ammonia injector 434. The ECU is connected to the ammonia flow sensor 423, the manifold ammonia injector 424, the liquid ammonia flow sensor 433, the direct injection liquid ammonia injector 434, and the oxygen sensor 270. The ECU adjusts the injection timing and injection pulse width of the manifold ammonia injector 424 or the direct injection liquid ammonia injector 434 according to the control signal of the electronic throttle 230 and the signal of the crankshaft position sensor 140, and corrects them through the feedback signal of the oxygen sensor 270 to ensure a stable excess air coefficient.

[0034] like Figure 2 As shown, a control method for an ammonia-hydrogen engine based on ammonia-gas combined injection is disclosed. This method provides ammonia fuel supply strategies for the engine under different operating conditions. The fuel supply strategies for the ammonia-hydrogen engine based on ammonia-gas combined injection include: a pure hydrogen intake port injection strategy, an ammonia intake port injection strategy, a dual-path ammonia injection strategy that simultaneously performs ammonia intake port injection and liquid ammonia direct injection in the cylinder, and a liquid ammonia direct injection in the cylinder. Among these, the pure hydrogen intake port injection strategy includes a pure hydrogen intake port enrichment injection strategy and a pure hydrogen intake port lean-burn injection strategy.

[0035] A control method for an ammonia-hydrogen engine device based on ammonia gas combined injection is described in the following steps:

[0036] Step 1: Before the engine starts, check P1 and P2. d Calibration is performed; where P1 is the pressure inside the ammonia storage tank when the net output power of the two strategies—liquid ammonia direct injection and ammonia intake port injection—is the same under optimal and identical conditions of high engine load, hydrogen supply, and ignition. d This is the critical pressure for the vaporization of liquid ammonia.

[0037] Calibration of P1: Refer to the instruction manual of the liquid ammonia compressor 431 used, and calibrate the power consumption of the liquid ammonia compressor 431 in advance according to the compression ratio, operating temperature, and properties of the medium. When the engine is under medium to high load conditions, this utility model adopts a dual-path ammonia injection strategy that simultaneously performs ammonia intake port injection and liquid ammonia direct injection in the cylinder. Under the same operating conditions within the above range, the net output power measured on the engine using only the two injection strategies of liquid ammonia direct injection in the cylinder and ammonia intake port injection is measured. Keeping the hydrogen supply and ignition conditions the same and at their optimal levels, as the pressure in the ammonia storage tank 410 gradually decreases, the pressure P in the ammonia storage tank 410 corresponding to the same net output power under the two injection strategies is measured and calibrated as P1. Wherein, net output power = output power - power consumption of liquid ammonia compressor 431.

[0038] P d Calibration: In the initial state, the pressure above the liquid ammonia surface in the ammonia storage tank 410 is P0, and the temperature inside the ammonia storage tank 410 is T0. Under the above conditions, this embodiment calibrates P0 according to the changes in T0 in the following two ways. d Method 1: If the temperature sensor 411 of the ammonia storage tank shows that the temperature T0 inside the ammonia storage tank 410 remains constant during engine operation, then the pressure P can be obtained by querying the condition that the ambient temperature T0 of liquid ammonia inside the ammonia storage tank 410 is exactly the boiling point. d Obviously there is P d<P0; Second, if the ammonia storage tank temperature sensor 411 shows a significant change in the temperature T0 inside the ammonia storage tank 410 during engine operation, it is necessary to use the data obtained from the ammonia storage tank temperature sensor 411 to plot the temperature change curve a of the ammonia storage tank 410 with the engine operating time. Then, using this curve, the saturated vapor pressure corresponding to the boiling point of liquid ammonia at the temperature inside the ammonia storage tank 410 is used to plot the saturated vapor pressure change curve b. The pressure change curve c of the ammonia storage tank with the engine operating time is plotted using the data obtained from the ammonia storage tank pressure sensor 412. Curves b and c are plotted on the same coordinate system, and the pressure P corresponding to the earliest intersection point is calibrated as P. d ; Calibrating P d This can provide reference data for the selection of ammonia supply strategies.

[0039] Step 2: Measure the pressure P inside the ammonia storage tank 410 using the pressure sensor 412. Compare the pressure P inside the ammonia storage tank 410 with the calibrated pressures P1 and P2. d By comparison, it is determined that the ammonia in the ammonia storage tank 410 is either liquid ammonia or ammonia gas.

[0040] Step 3: Based on the signals fed back to the ECU from various sensors and the accelerator pedal opening, the ECU determines the real-time operating condition of the engine. The engine sensors, including the liquid ammonia flow sensor 433, the ammonia flow sensor 423, the hydrogen flow sensor 330, the manifold pressure sensor 250, the camshaft position sensor 130, the crankshaft position sensor 140, the speed sensor, the air flow sensor 240, and the oxygen sensor 270, are connected to the ECU via wires. Each sensor transmits signals to feed back the engine's operating status to the ECU, which then determines the current engine condition.

[0041] Step 4: The ECU selects the corresponding fuel supply strategy based on the engine's operating conditions and the pressure in the ammonia storage tank, and each injector and valve executes the corresponding action:

[0042] The ECU receives the signal from the speed sensor. When the speed n changes from n=0 to n≠0, the engine is in cold start and warm-up mode. Under this mode, a pure hydrogen intake enrichment injection strategy is adopted to facilitate hydrogen combustion in the combustion chamber 113. The ECU controls the hydrogen pressure reducing valve 320, the manifold hydrogen injector 340, and the electronic throttle 230 to adjust the manifold hydrogen supply and air intake, and makes corrections based on the feedback signals from the hydrogen flow sensor 330 and the air flow sensor 240 to maintain the excess air coefficient λ<1. At the same time, the ECU controls the ammonia pressure reducing valve 422, the manifold ammonia injector 424, the liquid ammonia shut-off valve 432, and the in-cylinder direct injection liquid ammonia injector 434 to close, thereby ensuring that only pure hydrogen is injected under this mode.

[0043] Idle speed is an engine operating state in which the engine maintains a minimum stable speed and its power output is essentially zero. In a car, when the vehicle is stationary but the engine is still running, such as when waiting at a red light or briefly stopping without turning off the engine, the engine is in idle speed mode. At this time, the engine only needs to overcome its own internal friction and the energy required for the water pump and alternator to operate. Idle speed is usually within a specific range, which may vary depending on the type of engine, generally around 600-1000 rpm. Under this condition, the engine consumes less fuel, but if the idling time is too long or the idle speed is poorly controlled, it will lead to energy waste. The ECU obtains pre-set standard operating parameters for the idle speed condition, such as engine speed, intake air volume, and throttle opening. When the engine speed n is at n... 怠速-50 <n<n 怠速+50 Furthermore, the intake air volume is also in the lower range corresponding to idle speed, and the throttle opening is close to the minimum state, indicating that the engine is in idle condition. When the engine is in idle condition, a pure hydrogen intake port lean-burn injection strategy is adopted, and no power is output externally. Hydrogen combustion overcomes various mechanical resistances of the engine itself. The ECU controls the hydrogen pressure reducing valve 320, the manifold hydrogen injector 340, and the electronic throttle 230 to adjust the manifold hydrogen supply and air intake, and makes corrections based on the feedback signals from the hydrogen flow sensor 330 and the air flow sensor 240 to maintain an excess air coefficient λ > 1.2. At the same time, the ECU controls the ammonia pressure reducing valve 422, the manifold ammonia injector 424, the liquid ammonia shut-off valve 432, and the in-cylinder direct injection liquid ammonia injector 434 to close, thereby ensuring that only pure hydrogen is injected into the intake port under this condition.

[0044] In the cold start, warm-up, and idling conditions, the core requirement is not the output of power, but simply overcoming mechanical losses. However, in a cold start, ammonia is difficult to ignite, and liquid ammonia cannot fully vaporize, leading to fuel deposition. To address this issue, a pure hydrogen intake manifold injection strategy is employed in these conditions. Although hydrogen has a low energy density, its chemical reactivity and easy ignition allow it to burn effectively even in a cold start, increasing cylinder temperature and pressure. This avoids the problems faced by ammonia fuel in a cold start. Although continuous engine operation causes the pressure in the high-pressure hydrogen tank 310 to gradually decrease due to hydrogen consumption, the hydrogen phase remains stable and does not undergo a liquid-gas phase transition. Simultaneously, the negative pressure formed in the intake manifold 210 during engine operation, combined with the pressure difference in the high-pressure hydrogen tank 310, overcomes flow resistance, ensuring stable hydrogen injection into the intake manifold 210. Therefore, pure hydrogen combustion fully meets the requirements of these low-power demand conditions.

[0045] The ECU receives the signal from the speed sensor, when the speed n is at n 怠速+50 ≤n<6000 or 0≤W 需求 <W 额定 At ×30%, the engine is under low load. Under this condition, an ammonia intake port injection strategy is adopted, and the energy density released by ammonia combustion needs to meet the energy requirements under this condition. The ECU adjusts the injection volume of hydrogen and ammonia by controlling the injection pulse width of the hydrogen pressure reducing valve 320, the ammonia pressure reducing valve 422, the manifold hydrogen injector 340, and the manifold ammonia injector 424, thereby increasing the proportion of manifold hydrogen injection. The ECU controls the electronic throttle valve 230 to increase the opening of the electronic throttle valve 230, thereby increasing the air intake volume and reducing intake resistance. At the same time, the ECU controls the liquid ammonia shut-off valve 432 and the in-cylinder direct injection liquid ammonia injector 434 to remain closed. In this system, under low engine load conditions, ammonia is injected via the intake manifold. Compared to direct liquid ammonia injection, the mixture produced by intake manifold injection is more uniform, ensuring sufficient energy density during combustion and eliminating the additional energy consumption required for liquid ammonia compression. Furthermore, since manifold injection occupies some intake volume, the ECU increases the electronic throttle opening by 230 degrees to compensate for air losses, thereby reducing intake resistance. W 需求 Power requirements under different operating conditions; W 额定 This is the engine's maximum output power.

[0046] The ECU receives the signal from the speed sensor, when the speed n is at n 怠速+50 ≤n<6000 or W 额定 ×30%≤W 需求 ≤W 额定When the engine is under medium to high load, a dual-injection strategy of ammonia gas intake port injection and liquid ammonia direct injection in the cylinder is adopted. The crankshaft rotation drives the liquid ammonia compressor 431 to pressurize the liquid ammonia from the ammonia storage tank 410. The ECU adjusts the injection quantity of hydrogen, ammonia and liquid ammonia by controlling the injection pulse width of the hydrogen pressure reducing valve 320, the ammonia pressure reducing valve 422, the liquid ammonia shut-off valve 432, the manifold hydrogen injector 340, the manifold ammonia injector 424 and the direct injection liquid ammonia injector 434, and adjusts the engine output power by adjusting the excess air coefficient. The ECU controls the electronic throttle 230 to increase the opening degree of the electronic throttle 230 to K=100%. Wherein, P0 is the pressure in the ammonia storage tank 410 when it is full of liquid ammonia, and K is the opening degree of the electronic throttle. In particular, when the engine is under medium to high load conditions, a dual-path ammonia injection strategy is adopted, which simultaneously performs ammonia intake port injection and liquid ammonia direct injection in the cylinder. By utilizing the heat absorption characteristics of liquid ammonia vaporization in the combustion chamber 113, the temperature in the combustion chamber 113 is reduced and the tendency of hydrogen knocking is suppressed. At the same time, the combustion efficiency is improved by increasing the intake density and charge coefficient. Furthermore, ammonia intake port injection can improve the premixing uniformity of the in-cylinder mixture, improve the stratification state of the mixture generated by liquid ammonia direct injection in the cylinder, and improve the engine output power and thermal efficiency.

[0047] When the engine is under acceleration, frequent acceleration and deceleration require a fuel supply method with high dynamic response and precise adjustment of the in-cylinder mixture concentration. Therefore, a liquid ammonia direct injection strategy is adopted. The crankshaft rotation drives the liquid ammonia compressor 431 to pressurize the liquid ammonia from the ammonia storage tank 410. The ECU adjusts the injection quantity of hydrogen and liquid ammonia by controlling the injection pulse width of the hydrogen pressure reducing valve 320, the liquid ammonia shut-off valve 432, the manifold hydrogen injector 340, and the in-cylinder direct injection liquid ammonia injector 434, and adjusts the engine output power by adjusting the excess air coefficient. The ECU controls the electronic throttle 230 to increase the opening degree of the electronic throttle 230 to K=100%. At the same time, the ECU controls the ammonia pressure reducing valve 422 and the manifold ammonia injector 424 to close.

[0048] When the engine is under low load, medium-high load or acceleration conditions, hydrogen is injected through the pure hydrogen intake manifold, and the hydrogen blending ratio is greater than 10%.

[0049] The excess air coefficient λ of the mixture is:

[0050]

[0051] In the formula, m 空气 Intake mass flow rate; m 氨 The mass flow rate is for liquid ammonia or ammonia gas; m氢 For hydrogen mass flow rate; AF st，氨 The stoichiometric air-fuel ratio for liquid ammonia or ammonia gas; AF st，氢 This is the stoichiometric air-fuel ratio of hydrogen.

[0052] like Figure 3 As shown, the ammonia storage tank 410 initially stores liquid ammonia at a pressure of P0. As the engine operates, the liquid ammonia in the ammonia storage tank 410 is gradually consumed, causing the pressure inside the ammonia storage tank 410 to gradually decrease. Consequently, the energy consumption of the liquid ammonia compressor 431 for pressurization also increases. The temperature and pressure inside the ammonia storage tank 410 are monitored in real time by the ammonia storage tank temperature sensor 411 and the ammonia storage tank pressure sensor 412, and fed back to the ECU. The ECU determines the state of the ammonia inside the ammonia storage tank 410 and decides on the injection strategy based on the current pressure P range inside the ammonia storage tank 410 and the current engine operating conditions.

[0053] When the pressure P inside the ammonia storage tank 410 is at Figure 3 In Zone I (P1 ≤ P < P0), the ammonia storage tank 410 mainly contains liquid ammonia. The power loss of the liquid ammonia compressor 431 during pressurization is less than the output power gain brought by the liquid ammonia direct injection strategy. The temperature and pressure data inside the ammonia storage tank 410 are collected in real time by the ammonia storage tank temperature sensor 411 and the ammonia storage tank pressure sensor 412, and fed back to the ECU. The ECU, based on the current engine operating conditions, adopts either a liquid ammonia direct injection strategy or a dual-path ammonia injection strategy that simultaneously performs ammonia intake port injection and liquid ammonia direct injection.

[0054] When the pressure P inside the ammonia storage tank 410 is at Figure 3 In region II, i.e., P d ≤P<P1, the ammonia storage tank 410 mainly contains liquid ammonia, and the power loss of the liquid ammonia compressor 431 in boosting the pressure is greater than the output power gain brought by the liquid ammonia direct injection strategy. The temperature and pressure data in the ammonia storage tank 410 are collected in real time by the ammonia storage tank temperature sensor 411 and the ammonia storage tank pressure sensor 412 and fed back to the ECU. At this time, regardless of the engine's operating condition, the ECU controls the liquid ammonia shut-off valve 432 and the direct injection liquid ammonia injector 434 to be closed, leaving only the ammonia pressure reducing valve 422 and the manifold ammonia injector 424 open, adopting the ammonia intake port injection strategy.

[0055] When the pressure P inside the ammonia storage tank 410 is at Figure 3 In region III, i.e., 0 < P < P dThe liquid ammonia in the ammonia storage tank 410 begins to vaporize. The ammonia storage tank 410 mainly contains ammonia gas, which cannot be compressed or pressurized by the liquid ammonia. At this time, regardless of the engine's operating condition, the ECU controls the closure of the liquid ammonia shut-off valve 432 and the in-cylinder direct injection liquid ammonia injector 434, leaving only the ammonia pressure reducing valve 422 and the manifold ammonia injector 424 open, and adopting an ammonia intake manifold injection strategy.

[0056] The control method for an ammonia-hydrogen engine based on ammonia-gas combined injection is to select the ammonia injection strategy based on a comprehensive analysis of the engine operating conditions and the pressure inside the ammonia storage tank 410. When the engine is under medium-high load or acceleration conditions, the ammonia injection strategy employed involves direct liquid ammonia injection into the cylinder. Under these conditions, the direct liquid ammonia injection strategy places requirements on the pressure monitoring of the ammonia storage tank 410: the pressure P inside the ammonia storage tank 410 must be greater than the critical vaporization pressure P of liquid ammonia. d Otherwise, the liquid ammonia compressor 431 will malfunction due to liquid ammonia vaporization. Under medium to high load conditions, due to the need for greater power output, the pressure P in the ammonia storage tank 410 must be greater than the rated pressure P1. Otherwise, the ECU will shut off the liquid ammonia shut-off valve and the in-cylinder direct injection liquid ammonia injector 434, switching to ammonia intake manifold injection mode. When the engine is under acceleration conditions, the fuel supply method is required to have high dynamic response speed and precise adjustment of the in-cylinder mixture concentration. The power output requirement is relatively small, so the pressure P in the ammonia storage tank 410 is less than the rated pressure P1, but greater than the critical pressure P for liquid ammonia vaporization. d In some cases, a direct injection strategy of liquid ammonia into the cylinder can also be adopted.

[0057] Table 4: Ammonia Injection Strategy Selection Based on Comprehensive Analysis of Engine Operating Conditions and Ammonia Storage Tank Pressure

[0058]

[0059] As shown in Table 4, the control method for the ammonia-hydrogen engine based on ammonia-gas combined injection, based on a comprehensive analysis of engine operating conditions and the pressure in the ammonia storage tank 410, selects the ammonia injection strategy as follows: When the engine is in cold start and warm-up conditions, a pure hydrogen intake port enrichment injection strategy is adopted; when the engine is in idling conditions, a pure hydrogen intake port lean-burn injection strategy is adopted; when the engine is in low load conditions and the pressure P in the ammonia storage tank 410 satisfies 0 < P < P0, an ammonia intake port injection strategy is adopted; when the engine is in medium-high load conditions and the pressure P in the ammonia storage tank 410 satisfies P1 ≤ P < P0, a dual-path ammonia injection strategy is adopted, simultaneously performing ammonia intake port injection and liquid ammonia direct injection in the cylinder; when the engine is in medium-high load conditions and the pressure P in the ammonia storage tank 410 satisfies 0 < P < P1, an ammonia intake port injection strategy is adopted; when the engine is in acceleration conditions and the pressure P in the ammonia storage tank 410 satisfies P1 ≤ P < P0, a dual-path ammonia injection strategy is adopted. d When P ≤ P < P0, a liquid ammonia direct injection strategy is adopted; when the engine is in acceleration condition and the pressure P in the ammonia storage tank 410 satisfies 0 < P < P d At that time, an ammonia gas inlet injection strategy was adopted.

[0060] In practical applications, the control method for the ammonia-hydrogen engine device based on ammonia-gas combined injection will trigger a relevant alarm when the pressure P in the ammonia storage tank 410 drops to near the calibrated pressure P1, and timely and appropriate liquid ammonia will be added to maintain the liquid ammonia in the ammonia storage tank 410 at all times, so that the ammonia injection strategy can be selected only according to the engine operating conditions.

[0061] The ammonia-hydrogen engine device based on ammonia-gas composite injection provided by this utility model can appropriately adjust the ammonia injection mode and injection parameters according to the engine operating conditions, while simultaneously controlling the hydrogen injection quantity. Through dual-dimensional regulation of operating conditions and pressure, it eliminates the risk of backfire / misfire, extends hardware life, and provides a reliable technical path for the commercialization of ammonia-hydrogen engines. It can achieve high power output of the engine under different operating conditions, expand the stable operating range, achieve stable operation under all operating conditions, avoid abnormal combustion, and achieve zero carbon emissions from the engine. The liquid ammonia industry chain is mature, and the low proportion of hydrogen blending reduces storage and transportation costs. This utility model provides an ammonia-hydrogen engine device based on ammonia-hydrogen combined injection. Based on an ammonia-hydrogen dual-fuel injection structure and synergistic control design, the engine utilizes a dual-path ammonia supply mechanism with direct liquid ammonia injection in the cylinder and ammonia gas injection through the intake manifold. Combined with flexible switching between high-pressure liquid ammonia and low-pressure ammonia gas, direct liquid ammonia injection increases power density, while ammonia gas injection improves mixing uniformity, adapting to all operating conditions and significantly improving fuel adaptability and combustion efficiency. During cold start, a pure hydrogen injection strategy is employed; under other operating conditions, hydrogen serves as auxiliary fuel, igniting ammonia gas via manifold injection, thus solving the problem of difficult ammonia fuel ignition. Under medium to high loads… Switching to ammonia-hydrogen mixed injection utilizes the heat absorption of liquid ammonia vaporization to reduce knocking tendency, enabling the engine to maintain stable and efficient operation under different operating conditions. The liquid ammonia compressor is driven by the engine, realizing the pressurization and recycling of liquid ammonia, reducing external energy consumption. In conjunction with the ECU system integrating crankshaft / camshaft position sensors, multiple flow / pressure sensors, and oxygen sensors, the fuel status and engine operating conditions are monitored in real time. At the same time, the combustion products of ammonia-hydrogen fuel are only nitrogen and water, eliminating carbon dioxide emissions at the source and ensuring zero carbon emissions. The manifold pressure sensor monitors backfire risk in real time, and the ECU dynamically adjusts injection parameters to ensure safety.

[0062] The control method for an ammonia-hydrogen engine based on ammonia-gas combined injection selects the corresponding ammonia injection strategy according to the engine operating conditions and the pressure in the ammonia storage tank. Through multi-sensor fusion and dynamic parameter correction, precise control of the ammonia-hydrogen dual-fuel engine is achieved. The injection mode is automatically switched according to the pressure in the ammonia storage tank; when the pressure is insufficient, gaseous ammonia injection is prioritized to ensure continuous system operation and avoid energy consumption inversion and compressor damage. Simultaneously, the air-fuel ratio is corrected in real time based on oxygen sensor feedback signals to ensure a stable excess air coefficient. During engine cold starts and warm-up after start-up, pure hydrogen enrichment injection is used in the intake manifold. The system utilizes the flammable properties of hydrogen to rapidly raise the engine temperature, preventing ammonia buildup during cold starts. When the engine is idling, it employs lean-burn injection via the pure hydrogen intake manifold, using only hydrogen to overcome mechanical resistance, thus saving energy and reducing ammonia consumption. When the engine is under low load, it uses ammonia intake manifold injection combined with hydrogen-assisted combustion, increasing the throttle opening to compensate for the intake volume and reducing pumping losses. When the engine is under medium to high load, it employs dual-path ammonia injection, combining ammonia intake manifold injection and liquid ammonia direct injection in the cylinder, with liquid ammonia vaporization absorbing heat to suppress hydrogen knock. When the engine is accelerating, it uses liquid ammonia direct injection in the cylinder to quickly respond to dynamic demands.

[0063] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. An ammonia-hydrogen engine device based on ammonia compound injection, characterized by, include: Engine cylinders; An in-cylinder direct injection liquid ammonia injector is connected to the cylinder block end of the engine cylinder; A manifold hydrogen injector, which is mounted on the intake manifold connected to the engine cylinder; A manifold ammonia injector is installed on the intake manifold connected to the engine cylinder; A high-pressure hydrogen tank, connected to the manifold hydrogen injector, is used to supply hydrogen. An ammonia storage tank, which is connected to the manifold ammonia injector and the in-cylinder direct-injection liquid ammonia injector, is used to supply ammonia.

2. The ammonia-hydrogen engine apparatus based on ammonia gas recombination injection according to claim 1, characterized by, A hydrogen pressure reducing valve and a hydrogen flow sensor are provided between the high-pressure hydrogen tank and the manifold hydrogen injector.

3. The ammonia-hydrogen engine apparatus based on ammonia gas recombination injection according to claim 2, characterized by, A liquid ammonia vaporizer, an ammonia pressure reducing valve, and an ammonia flow sensor are provided between the ammonia storage tank and the manifold ammonia injector.

4. The ammonia-hydrogen engine apparatus based on ammonia gas recombination injection according to claim 3, characterized by A liquid ammonia compressor, a liquid ammonia shut-off valve, and a liquid ammonia flow sensor are provided between the ammonia storage tank and the in-cylinder direct injection liquid ammonia injector.

5. The ammonia-hydrogen engine apparatus based on ammonia gas recombination injection according to claim 4, characterized by Also includes: The ammonia storage tank temperature sensor and the ammonia storage tank pressure sensor are both installed on the ammonia storage tank.

6. The ammonia-hydrogen engine apparatus based on ammonia gas recombination injection according to claim 5, characterized by Also includes: An electronic control unit is connected to the hydrogen pressure reducing valve, the hydrogen flow sensor, the manifold hydrogen injector, the ammonia pressure reducing valve, the ammonia flow sensor, the manifold ammonia injector, the liquid ammonia shut-off valve, the liquid ammonia flow sensor, the in-cylinder direct injection liquid ammonia injector, the ammonia storage tank temperature sensor, and the ammonia storage tank pressure sensor.

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