Alcohol-hydrogen hybrid engine pre-chamber system and control method thereof

Abstract

The present application belongs to the technical field of internal combustion engine, and particularly relates to a kind of alcohol hydrogen fusion engine precombustion chamber system and its control method.Alcohol hydrogen fusion engine precombustion chamber system includes the engine main body with the main combustion chamber and precombustion chamber being communicated with each other, and also includes methanol supply unit, hydrogen production unit, hydrogen delivery control unit, exhaust gas recirculation unit and main control unit;Main control unit collects engine operating parameters and judges current working condition, and adjusts methanol supply path, hydrogen supply path, precombustion chamber working mode, hydrogen production unit heating mode and on-off state of exhaust gas recirculation unit according to working condition.The present application can realize engine full-condition combustion performance optimization without complex auxiliary device, and also considers cold start reliability, high and low load combustion stability and operation energy efficiency, to improve the whole machine operation reliability and transient response capability.

Description

Technical Field

[0001] This invention belongs to the field of internal combustion engine technology, specifically relating to a pre-combustion chamber system and control method for an alcohol-hydrogen fusion engine. Background Technology

[0002] Methanol-fueled engines have seen widespread application in the internal combustion engine field in recent years due to their advantages such as low emissions and high efficiency. As a low-carbon, clean alternative fuel, methanol fuel has a wide range of sources and low carbon emissions, aligning with the development direction of power fuel transformation under the dual-carbon goals. However, methanol fuel itself has inherent limitations in its physicochemical properties. For example, its high latent heat of vaporization and difficulty in atomization and evaporation at low temperatures directly lead to poor air-fuel mixture quality during cold starts and warm-up, unstable combustion, low start-up success rate, and increased emissions from incomplete combustion. Simultaneously, methanol has a slow flame propagation speed and high ignition energy requirements. Under low-load conditions, the cylinder temperature is insufficient, resulting in a slow combustion rate, large cycle fluctuations, and difficulty in effectively improving thermal efficiency. Under high-load conditions, the cylinder pressure and temperature rise sharply, easily triggering pre-ignition and knocking, leading to damage to mechanical components and shortening engine lifespan.

[0003] To address the aforementioned technical challenges, existing technologies include optimized solutions for methanol-hydrogen production assisted by methanol cracking, such as the spark-ignition methanol cracking engine disclosed in Chinese patent document CN115773193B. This spark-ignition methanol cracking engine treats a methanol-water mixture in an evaporator, followed by cracking in a cracker. The resulting hydrogen-containing gas is mixed with air and then fed into the engine for combustion. Differentiated control strategies are employed for different load conditions: at low loads, plasma treatment is introduced to increase combustion speed; at medium loads, methanol steam cracking and hot exhaust gas recirculation are combined to improve hydrogen production efficiency; and at high loads, cold exhaust gas recirculation is used to reduce knocking tendency, thus balancing combustion efficiency and operational stability under different operating conditions.

[0004] However, the aforementioned spark-ignition methanol cracking engine requires the integration of a plasma generator, two sets of hot and cold exhaust gas recirculation loops, and a steam cracking supporting structure. The entire system is complex, with a large number of parts, which increases manufacturing costs and daily maintenance difficulty, and also reduces the overall reliability of the engine. At the same time, the methanol cracking hydrogen production process has a fixed reaction delay, and relying solely on cracking gas production is insufficient to quickly respond to the power demands of transient operating conditions such as engine acceleration. Combustion stability is insufficient during operating condition switching, making it difficult to fully cover the combustion optimization requirements under all operating conditions. Summary of the Invention

[0005] The purpose of this invention is to propose a pre-combustion chamber system and its control method for an alcohol-hydrogen fusion engine, in order to solve the technical problem that the existing methanol cracking hydrogen production combustion system has a complex structure and is difficult to optimize combustion performance and improve operational reliability across all operating conditions. The purpose of this invention is also to propose a control method for the pre-combustion chamber system of an alcohol-hydrogen fusion engine, so as to achieve optimization of combustion performance and improvement of operational reliability of the engine across all operating conditions.

[0006] To address the above problems, the present invention proposes a technical solution for a pre-combustion chamber system for an alcohol-hydrogen fusion engine: A pre-combustion chamber system for an alcohol-hydrogen fusion engine includes an engine body, within which a main combustion chamber and a pre-combustion chamber are interconnected, and a spark plug is disposed within the pre-combustion chamber; it also includes: A methanol supply unit is connected to the intake system and hydrogen production unit of the engine body, respectively, and is used to controllably supply liquid methanol fuel to the intake system and / or hydrogen production unit. The hydrogen production unit is located outside the pre-combustion chamber and connected to the exhaust system of the engine body. It is used to receive liquid methanol fuel and heat and crack it to produce hydrogen. A hydrogen delivery control unit is connected to the hydrogen production unit, the pre-combustion chamber, and the air intake system, respectively, for controllably delivering hydrogen output from the hydrogen production unit to the air intake system, and controllably pressurizing and delivering hydrogen to the pre-combustion chamber. The exhaust gas recirculation unit connects the intake and exhaust systems of the engine block to controllably reintroduce exhaust gases discharged from the engine block into the cylinders of the engine block. The main control unit is communicatively connected to the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and exhaust gas recirculation unit. It is used to collect the operating parameters of the engine body and determine the current operating condition. Based on the operating condition, it adjusts the methanol supply path, hydrogen supply path, pre-combustion chamber operating mode, hydrogen production unit heating method, and exhaust gas recirculation unit on / off status accordingly.

[0007] The beneficial effects of the methanol-hydrogen fusion engine pre-combustion chamber system: This invention combines the advantages of both methanol and hydrogen fuels. By controlling the operation of the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and exhaust gas recirculation unit through the main control unit, the supply paths of methanol and hydrogen fuels, the working mode of the pre-combustion chamber, the hydrogen production heating method, and the exhaust gas recirculation status can be dynamically adjusted according to the real-time operating conditions of the engine. Without the need for additional complex plasma generators and multiple exhaust gas circuits, combustion performance optimization can be achieved across the entire operating range, taking into account cold start reliability, high and low load combustion stability, and operating efficiency, thereby improving the overall reliability and transient response capability of the engine.

[0008] Furthermore, the methanol supply unit includes a methanol storage container, a first methanol control valve, and a second methanol control valve; the output end of the methanol storage container is divided into two paths, one path is connected to the methanol nozzle in the air intake system via the first methanol control valve, and the other path is connected to the feed end of the hydrogen production unit via the second methanol control valve; the main control unit is communicatively connected to the first methanol control valve and the second methanol control valve respectively.

[0009] Beneficial effects: Using a single methanol supply unit allows for flexible supply of methanol fuel to the intake system and / or hydrogen production unit according to operating conditions, simplifying the system structure and improving the flexibility and adaptability of fuel supply.

[0010] Furthermore, the hydrogen delivery control unit includes a hydrogen storage container, a first hydrogen control valve, and a second hydrogen control valve; the input end of the hydrogen storage container is connected to the output end of the hydrogen production unit, and the output end is divided into two paths, one path is connected to the gas inlet system via the first hydrogen control valve, and the other path is connected to the pre-combustion chamber via the second hydrogen control valve. The main control unit is communicatively connected to the first hydrogen control valve and the second hydrogen control valve.

[0011] Beneficial effects: The hydrogen storage container buffers the hydrogen produced by the hydrogen production unit and divides the hydrogen output path into two paths, which are connected to the intake system and the pre-combustion chamber respectively. On the one hand, hydrogen can be mixed into the intake system to improve the overall combustion characteristics of the mixture. On the other hand, hydrogen can be supplied to the pre-combustion chamber to realize the switching of the pre-combustion chamber's working mode. At the same time, the hydrogen storage container can buffer the reaction delay of cracking hydrogen production, improve the stability of hydrogen supply during the switching of operating conditions, and improve the response speed and combustion reliability of the engine under transient operating conditions.

[0012] Furthermore, the hydrogen production unit includes a methanol cracker, which is equipped with an electric heating element and a waste gas heating component. The waste gas heating component is connected to the exhaust system, and the main control unit selectively uses electric heating and / or waste heat from the waste gas to heat the methanol cracker.

[0013] Beneficial effects: The methanol cracker directly produces hydrogen from liquid methanol, which is a mature technology and does not require the introduction of additional types of hydrogen production feedstock. In addition, the methanol cracker has two heating structures that can be used independently or in combination, reducing the system's additional energy consumption and taking into account the reliability and energy utilization efficiency of the hydrogen production reaction under different operating conditions.

[0014] Furthermore, the exhaust gas recirculation unit includes an exhaust gas pipeline and an exhaust gas control valve installed on the exhaust gas pipeline; one end of the exhaust gas pipeline is connected to the exhaust system, and the other end is connected to the intake system; the exhaust gas control valve is communicatively connected to the main control unit and is used to control the opening and closing of the exhaust gas pipeline.

[0015] Beneficial effects: The exhaust gas control valve can control the opening and closing of the exhaust gas pipeline. Under high load conditions, it introduces exhaust gas to reduce the combustion temperature in the cylinder to suppress knocking, and under low load conditions, it cuts off the exhaust gas supply to reduce cycle fluctuations, thus matching the combustion control requirements of different operating conditions.

[0016] The technical solution for the control method of the pre-combustion chamber system of the alcohol-hydrogen fusion engine is as follows: A control method for the pre-combustion chamber system of an alcohol-hydrogen fusion engine, based on the pre-combustion chamber system of an alcohol-hydrogen fusion engine in any of the above-mentioned technical solutions, is executed by a main control unit and includes the following steps: Obtain the current operating parameters of the engine body, including engine speed, actual output torque, coolant temperature, and power change rate; The current operating condition of the engine is determined based on the operating parameters, which include cold start and warm-up conditions, acceleration conditions, high load conditions, and low load conditions. Based on the current operating conditions, corresponding adaptive control commands are generated to coordinate the operation of the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and waste gas recirculation unit.

[0017] The beneficial effects of the control method are as follows: This invention identifies the current operating condition by collecting engine operating parameters from multiple dimensions, and coordinates the action state of multiple functional units based on the current operating condition to achieve adaptive matching of combustion requirements under different operating conditions. It can take corresponding optimization measures for combustion problems under different operating conditions to ensure that the engine can maintain a highly efficient and stable combustion state under various operating conditions.

[0018] Furthermore, when the engine speed is not higher than the idle speed range, the current actual output torque of the engine is not higher than 5% of the external characteristic torque at the current speed, and the coolant temperature is not higher than 50°C, the current operating condition is determined to be a cold start and warm-up condition, and the main control unit executes the following control instructions: Shut down the exhaust gas recirculation unit; The methanol supply unit is controlled to cut off the supply of liquid methanol to the intake system and start the supply of liquid methanol to the hydrogen production unit. Turn on the hydrogen production unit and control the hydrogen production unit to operate only by electric heating. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, while the path for actively supplying hydrogen to the pre-combustion chamber is cut off, putting the pre-combustion chamber into a passive working mode.

[0019] Beneficial effects: By shutting down the exhaust gas recirculation unit during cold starts and warm-up, the dilution of the combustible mixture by exhaust gas can be avoided, thus preventing a decrease in ignition reliability. All methanol is fed into the hydrogen production unit and pure electric heating is used to ensure the production of cracked gas. At the same time, hydrogen is supplied only to the intake system and the pre-combustion chamber is in passive mode. The good ignition characteristics of hydrogen are used to improve the ignition success rate in low-temperature environments, avoiding the starting difficulties and incomplete combustion problems caused by poor atomization of liquid methanol at low temperatures. This effectively improves the operating performance of the engine during cold starts and warm-up.

[0020] Furthermore, when the power change rate is not less than 8% / s to 12% / s of the engine's rated power, the current operating condition is determined to be an acceleration condition, and the main control unit executes the following control commands: Shut down the exhaust gas recirculation unit; The methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; Turn on the hydrogen production unit and control the hydrogen production unit to operate by using a combination of electric heating and waste heat from the exhaust gas. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, and at the same time, the hydrogen is pressurized and delivered to the pre-combustion chamber, so that the pre-combustion chamber is in active working mode.

[0021] Beneficial effects: The exhaust gas recirculation unit is shut down under accelerated operating conditions, ensuring combustion response speed; methanol is supplied to both the intake system and the hydrogen production unit, balancing transient power requirements with continuous hydrogen production capacity; dual heat sources are used for heating to ensure the rate of cracking gas production; hydrogen is supplied to the intake system and the pre-combustion chamber simultaneously, putting the pre-combustion chamber in an active operating mode, enhancing ignition energy, improving combustion stability, effectively alleviating the reaction delay problem of cracking hydrogen production, and improving the power response speed during acceleration.

[0022] Furthermore, when the power change rate is lower than 8% / s to 12% / s of the engine's rated power, and the engine's current actual output torque is not lower than 80% of the external characteristic torque at the current speed, the current operating condition is determined to be a high-load condition, and the main control unit executes the following control instructions: Start the exhaust gas recirculation unit; The methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; Turn on the hydrogen production unit and control the hydrogen production unit to operate only by using the waste heat of the exhaust gas for heating. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, and at the same time, the hydrogen is pressurized and delivered to the pre-combustion chamber, so that the pre-combustion chamber is in active working mode.

[0023] Beneficial effects: Under high load conditions, activating the exhaust gas recirculation unit can reduce the peak combustion temperature in the cylinder, thereby suppressing knocking tendency; at the same time, supplying hydrogen to the pre-combustion chamber puts the pre-combustion chamber in an active working mode, which can improve ignition energy and shorten the combustion delay period, offsetting the problem of reduced combustion rate caused by exhaust gas recirculation; the hydrogen production unit only uses the waste heat of exhaust gas for heating, recovers exhaust energy and reduces the system's additional energy consumption, ensuring the engine's thermal efficiency while suppressing knocking.

[0024] Furthermore, when the power change rate is lower than 8% / s to 12% / s of the engine's rated power, and the engine's current actual output torque is lower than 80% of the external characteristic torque at the current speed, the current operating condition is determined to be a low-load condition, and the main control unit executes the following control instructions: Shut down the exhaust gas recirculation unit; The methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; Turn on the hydrogen production unit and control the hydrogen production unit to operate by using a combination of electric heating and waste heat from the exhaust gas. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, while the path for actively supplying hydrogen to the pre-combustion chamber is cut off, putting the pre-combustion chamber into a passive working mode.

[0025] Beneficial effects: Turning off the exhaust gas recirculation unit under low load conditions can reduce engine cycle fluctuations and improve combustion stability. By supplying hydrogen only to the intake system and putting the pre-combustion chamber in a passive working mode, the excellent combustion characteristics of hydrogen can be utilized to improve the combustion rate under low load conditions, while reducing unnecessary hydrogen consumption. Methanol is supplied to both the intake system and the hydrogen production unit. With the help of dual heat source heating, the hydrogen production stability at low exhaust temperatures is ensured, effectively improving the combustion thermal efficiency under low load conditions. Attached Figure Description

[0026] Figure 1 A schematic diagram of the pre-combustion chamber system of an alcohol-hydrogen fusion engine; Figure 2 A schematic diagram of the operating conditions of the pre-combustion chamber system of an alcohol-hydrogen fusion engine; Figure 3 This is a schematic diagram of the control process of the pre-combustion chamber system of an alcohol-hydrogen fusion engine under different operating conditions.

[0027] Explanation of reference numerals in the attached figures: 1. Methanol storage container; 2. Methanol nozzle; 3. Pre-combustion chamber; 4. First methanol control valve; 5. Second methanol control valve; 6. Methanol cracker; 7. Battery; 8. Exhaust gas pipeline; 9. Exhaust gas control valve; 10. Hydrogen pump; 11. Inlet duct; 12. Exhaust duct; 13. First hydrogen control valve; 14. Second hydrogen control valve; 15. Spark plug; 16. Piston; 17. Hydrogen storage container. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] Specific embodiments of the alcohol-hydrogen fusion engine pre-combustion chamber system proposed in this invention: The methanol-hydrogen fusion engine pre-combustion chamber system includes the engine body and its supporting methanol supply unit, hydrogen production unit, hydrogen delivery control unit, exhaust gas recirculation unit, and main control unit.

[0030] Specifically, such as Figure 1 As shown, the engine block contains a cylinder, and a piston 16 is mounted inside the cylinder. The piston 16 reciprocates along the inner wall of the cylinder, and the internal space above the piston 16 constitutes the main combustion chamber. A pre-combustion chamber 3, which communicates with the main combustion chamber, is also installed inside the engine block. A spark plug 15 is installed inside the pre-combustion chamber 3. The lower end of the pre-combustion chamber 3 extends into the main combustion chamber, and a jet orifice is provided at the bottom of the pre-combustion chamber 3, which extends axially through the pre-combustion chamber 3, directly connecting the internal cavity of the pre-combustion chamber 3 with the main combustion chamber below. The spark plug 15 is fixedly installed at the top of the pre-combustion chamber 3, with its ignition end facing the internal cavity of the pre-combustion chamber 3, for igniting the air-fuel mixture inside the pre-combustion chamber 3. The engine block's intake system includes an intake manifold 11, and the exhaust system includes an exhaust manifold 12. The outlet end of the intake duct 11 is connected to the intake side of the cylinder and is used to deliver the air-fuel mixture to the main combustion chamber; the inlet end of the exhaust duct 12 is connected to the exhaust side of the cylinder and is used to discharge the exhaust gas that has been burned in the main combustion chamber.

[0031] The methanol supply unit stores and distributes liquid methanol fuel, including a methanol storage container 1, a first methanol control valve 4, and a second methanol control valve 5. The methanol storage container 1 stores liquid methanol, and its output is connected to the main methanol supply pipeline. The main methanol supply pipeline branches into two branches. The first branch extends into the intake duct 11, and a methanol nozzle 2 is installed at its end. The first methanol control valve 4 controls the flow and on / off state of the liquid methanol flowing into the intake duct 11. The second branch extends to the feed end of the hydrogen production unit, and a second methanol control valve 5 is installed thereon. The second methanol control valve 5 controls the flow and on / off state of the liquid methanol flowing into the hydrogen production unit. Both the first methanol control valve 4 and the second methanol control valve 5 are connected to the main control unit via control lines, receiving control signals from the main control unit to adjust their opening and on / off states.

[0032] The hydrogen production unit is located outside the pre-combustion chamber 3, situated in the outer region of the exhaust duct 12, facilitating heat exchange using exhaust waste heat. The hydrogen production unit includes a methanol cracker 6, which contains a cracking reaction chamber. The feed end of the cracking reaction chamber connects to the second methanol supply branch of the methanol supply unit, while the discharge end connects to the input of the hydrogen delivery control unit. The methanol cracker 6 contains an electric heating element and an exhaust gas heating assembly. The electric heating element can be a heating wire and is electrically connected to a battery 7, which supplies power to the electric heating element. The exhaust gas heating assembly includes a surrounding exhaust gas channel. The inlet of the channel connects to the exhaust duct 12, allowing the high-temperature exhaust gas from the engine to flow through the exhaust gas heating assembly and transfer heat to the cracking reaction chamber through heat exchange. The main control unit is connected to the control components of both the electric heating element and the exhaust gas heating assembly, allowing selection based on engine operating conditions: electric heating alone, exhaust waste heat heating alone, or a combination of both heating methods. After liquid methanol enters the cracking reaction chamber, it undergoes a cracking reaction under high temperature to generate hydrogen-rich fuel gas containing hydrogen and carbon monoxide. The hydrogen-rich fuel gas is output from the discharge end to the hydrogen delivery control unit.

[0033] The hydrogen delivery control unit is used to buffer and distribute the hydrogen-rich fuel gas produced by the hydrogen production unit, and includes a hydrogen storage container 17, a first hydrogen control valve 13, and a second hydrogen control valve 14. The input end of the hydrogen storage container 17 is connected to the output end of the methanol cracker 6 to buffer the continuously produced hydrogen-rich fuel gas from the methanol cracker 6. The output end of the hydrogen storage container 17 is connected to the main hydrogen delivery pipeline, which splits into two hydrogen delivery branches at its end. The first hydrogen delivery branch extends into the air inlet duct 11, and the first hydrogen control valve 13 is installed on this branch. The first hydrogen control valve 13 controls the on / off state and flow rate of hydrogen flowing into the air inlet duct 11. The second hydrogen delivery branch extends to the air inlet of the pre-combustion chamber 3, and the second hydrogen control valve 14 and a hydrogen pump 10 are installed sequentially on this branch. The hydrogen pump 10 pressurizes the hydrogen to ensure a stable injection of hydrogen into the pre-combustion chamber 3, and the second hydrogen control valve 14 controls the on / off state of the hydrogen flowing into the pre-combustion chamber 3. The first hydrogen control valve 13, the second hydrogen control valve 14, and the hydrogen pump 10 are all connected to the main control unit through control lines, and the main control unit controls the start, stop, and opening degree according to the working conditions.

[0034] The exhaust gas recirculation unit is used to regulate the in-cylinder combustion temperature and combustion rate, and includes an exhaust gas pipeline 8 and an exhaust gas control valve 9. One end of the exhaust gas pipeline 8 is connected to the exhaust manifold 12, and the other end is connected to the intake manifold 11. The exhaust gas control valve 9 is installed on the exhaust gas pipeline 8 and is connected to the main control unit via a control circuit. The main control unit controls the proportion of exhaust gas introduced from the exhaust manifold 12 into the intake manifold 11 by adjusting the opening of the exhaust gas control valve 9. After entering the intake manifold 11, the exhaust gas mixes with the air-fuel mixture and enters the main combustion chamber, which can dilute the mixture concentration, reduce the peak combustion temperature, and achieve the effects of suppressing knocking and reducing nitrogen oxide generation.

[0035] It should be noted that the engine in this embodiment is an alcohol-hydrogen fusion engine, which is an internal combustion engine that combines methanol and hydrogen as the main fuels. It aims to improve efficiency, reduce emissions, and overcome the limitations of a single fuel by utilizing the advantages of the two fuels.

[0036] The main control unit (MCU) functions based on the engine's electronic control unit (ECU). It communicates with the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and exhaust gas recirculation unit. It collects engine operating parameters and determines the current operating condition, then coordinates and adjusts the operating status of each unit accordingly to achieve combustion optimization across the entire operating range. Engine operating parameters include engine speed, actual output torque, and coolant temperature. The MCU calculates the engine's real-time power and power change rate based on the collected speed and actual output torque parameters. The MCU internally stores operating condition judgment logic and corresponding control strategies. It determines the engine's current operating condition based on the real-time collected and calculated operating parameters and outputs corresponding control commands to adjust the operating status of each component.

[0037] like Figure 2 and Figure 3 As shown, the engine's operating conditions are divided into cold start and warm-up conditions, acceleration conditions, high load conditions, and low load conditions.

[0038] During cold start and warm-up, the main control unit closes the exhaust gas control valve 9, cutting off the passage of the exhaust gas pipeline 8 to prevent the exhaust gas from diluting the mixture and causing a decrease in ignition reliability. The main control unit closes the first methanol control valve 4 and opens the second methanol control valve 5, allowing all liquid methanol to enter the methanol cracker 6. Simultaneously, the main control unit activates the electric heating element, using electric heating alone to provide heat to the methanol cracker 6, ensuring stable cracking reaction under low-temperature exhaust conditions. The hydrogen-rich gas generated from methanol cracking is transported to the hydrogen storage container 17 for buffering. The main control unit opens the first hydrogen control valve 13, while the hydrogen pump 10 and the second hydrogen control valve 14 remain closed. Hydrogen enters the intake duct 11 only through the first hydrogen supply branch, mixes with air, and then enters the main combustion chamber. At this time, the pre-combustion chamber 3 has no additional hydrogen supply and is in passive working mode. During the compression stroke, the mixture in the main combustion chamber enters the pre-combustion chamber 3 through the jet orifice, is ignited by the spark plug 15, and then ignites the mixture in the main combustion chamber. Under this condition, the excellent ignition characteristics of hydrogen are utilized to improve the ignition success rate in low-temperature environments, avoid starting difficulties caused by poor atomization of liquid methanol at low temperatures, and ensure combustion stability during cold starts and warm-up phases.

[0039] Under acceleration conditions, the main control unit closes the exhaust gas control valve 9 to prevent exhaust gas from affecting the combustion response speed. The main control unit simultaneously opens the first methanol control valve 4 and the second methanol control valve 5, allowing some liquid methanol to be directly injected into the intake duct 11 through the methanol nozzle 2, quickly responding to the increased fuel demand for power. Some liquid methanol enters the methanol cracker 6 to continuously produce hydrogen. The main control unit controls the electric heating element and the exhaust gas heating assembly to work simultaneously, increasing the cracking reaction rate and ensuring that the hydrogen production rate matches the changing operating conditions. The main control unit simultaneously opens the first hydrogen control valve 13, the second hydrogen control valve 14, and the hydrogen pump 10. One path of hydrogen enters the intake duct 11 to mix with air and methanol, while the other path, after pressurization, is sent into the pre-combustion chamber 3. At this time, the pre-combustion chamber 3 is in active working mode. The spark plug 15 ignites the hydrogen-rich mixture in the pre-combustion chamber 3 first, and the resulting high-temperature jet is injected into the main combustion chamber through the jet orifice, significantly increasing the ignition energy, ensuring combustion stability under transient conditions, alleviating the reaction delay problem of cracking to produce hydrogen, and improving the power response speed during acceleration.

[0040] Under high-load conditions, the main control unit controls the opening of the exhaust gas control valve 9, allowing some exhaust gas to enter the intake duct 11 via the exhaust gas pipeline 8. This dilutes the mixture concentration and lowers the peak combustion temperature in the main combustion chamber, thereby suppressing knocking tendencies. The main control unit simultaneously controls the opening of the first methanol control valve 4 and the second methanol control valve 5 to meet the fuel demand for high-power output, while continuously supplying methanol for cracking and hydrogen production. The main control unit controls the shut-off of the electric heating element, utilizing only the waste heat from the high-temperature exhaust gas through the exhaust gas heating component to provide heat to the methanol cracker 6, recovering exhaust waste heat and reducing additional energy consumption of the system. The main control unit simultaneously controls the opening of the first hydrogen control valve 13, the second hydrogen control valve 14, and the hydrogen pump 10, putting the pre-combustion chamber 3 in active working mode. Hydrogen injection into the pre-combustion chamber 3 enhances ignition energy, shortens the combustion delay period, and offsets the decrease in combustion rate caused by exhaust gas recirculation, ensuring combustion efficiency under high-load conditions while suppressing knocking.

[0041] Under low-load conditions, the main control unit closes the exhaust gas control valve 9 to prevent the exhaust gas from aggravating combustion cycle fluctuations and improving combustion stability under low load. The main control unit simultaneously opens the first methanol control valve 4 and the second methanol control valve 5, injecting methanol into the gas passage to reduce pumping losses, and allowing some methanol to enter the cracker for continuous hydrogen production. The main control unit controls the electric heating element and the exhaust gas heating assembly to work simultaneously to compensate for insufficient exhaust temperature under low load, ensuring stable cracking reaction. The main control unit opens the first hydrogen control valve 13, while the hydrogen pump 10 and the second hydrogen control valve 14 remain closed. Hydrogen only enters the intake passage 11 to mix with air and methanol, utilizing the excellent combustion characteristics of hydrogen to improve the combustion rate under low load. At this time, the pre-combustion chamber 3 is in passive working mode, reducing unnecessary hydrogen consumption and improving thermal efficiency under low-load conditions while ensuring combustion stability.

[0042] In summary, the methanol-hydrogen fusion engine pre-combustion chamber system of the present invention can coordinately adjust the methanol supply path, hydrogen supply path, working mode of pre-combustion chamber 3, heating method of methanol cracker 6, and on / off state of exhaust gas recirculation unit according to the combustion characteristics of different operating conditions, thereby achieving combustion performance optimization of the engine across the entire operating range.

[0043] In the above embodiments, the methanol supply unit employs a structure where a methanol storage container 1 and two independent control valves control the two methanol supply lines respectively. The first methanol control valve 4 and the second methanol control valve 5 control the on / off state and flow rate of the intake branch and the hydrogen production unit branch, respectively. In other embodiments, the methanol supply unit can also adopt a structure with a single output and a proportional distribution valve. The input end of the proportional distribution valve is connected to the output pipeline of the methanol storage container 1, and the two output ends are respectively connected to the methanol nozzle 2 in the intake duct and the feed end of the hydrogen production unit. The main control unit adjusts the internal opening ratio of the proportional distribution valve to simultaneously control the supply flow rate of the two methanol lines, which can reduce the number of independent control valves and simplify the overall pipeline layout.

[0044] In the above embodiments, the hydrogen delivery control unit adopts a structure in which the hydrogen pump 10 is separately installed on the pre-combustion chamber supply branch, and only pressurizes the hydrogen supplied to the pre-combustion chamber 3. In other embodiments, the hydrogen delivery control unit can also adopt a structure in which a main hydrogen pump is used in conjunction with two flow regulating valves. The hydrogen pump 10 is installed on the main output line of the hydrogen storage container 17 to pressurize the output hydrogen uniformly. Flow regulating valves are installed on the two branches to control the hydrogen flow of the intake branch and the pre-combustion chamber branch respectively. This can improve the stability of the hydrogen supply pressure of the two branches, and at the same time, it eliminates the need to configure a separate booster pump for the pre-combustion chamber branch, thus optimizing the system structure.

[0045] In the above embodiments, the hydrogen production unit uses a pure thermal cracking type methanol cracker 6, where heat provided by electric heating elements and exhaust gas heating components directly induces the methanol cracking reaction. In other embodiments, the hydrogen production unit can also use a catalytic cracking type methanol cracker, with the cracking reaction chamber filled with copper-based catalytic packing. The catalyst can reduce the activation energy of the methanol cracking reaction, achieving stable cracking and gas production at lower temperatures. Combined with the dual heating method of electric heating elements and exhaust gas heating components, the operating time of the electric heating elements can be reduced, further lowering the system's operating energy consumption.

[0046] Examples of control methods for the pre-combustion chamber system of an alcohol-hydrogen fusion engine: The control method for the pre-combustion chamber system of the alcohol-hydrogen fusion engine, based on the alcohol-hydrogen fusion engine pre-combustion chamber system in the above embodiments, is executed by the main control unit and includes the following steps: Obtain the current operating parameters of the engine body, including engine speed, actual output torque, coolant temperature, and power change rate; The current operating condition of the engine is determined based on the operating parameters, which include cold start and warm-up conditions, acceleration conditions, high load conditions, and low load conditions. Based on the current operating conditions, corresponding adaptive control commands are generated to coordinate the operation of the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and waste gas recirculation unit.

[0047] Specifically, when the engine speed is not higher than the idle speed range, the current actual output torque of the engine is not higher than 5% of the external characteristic torque at the current speed, and the coolant temperature is not higher than 50°C, the current operating condition is determined to be a cold start and warm-up condition, and the main control unit executes the following control instructions: The exhaust gas recirculation unit is shut down; the methanol supply unit is controlled to cut off the supply of liquid methanol to the intake system and start the supply of liquid methanol to the hydrogen production unit; the hydrogen production unit is started and controlled to operate only by electric heating; the hydrogen delivery control unit is started to supply hydrogen to the intake system, while the path of actively supplying hydrogen to the pre-combustion chamber 3 is cut off, so that the pre-combustion chamber 3 is in passive working mode. It should be noted that the idle speed range varies between different engine models. In actual application, the idle speed range is determined according to the engine model used, such as 600 r / min to 900 r / min.

[0048] When the power change rate is not less than 8% / s to 12% / s of the engine's rated power, the current operating condition is determined to be an acceleration condition, and the main control unit executes the following control commands: The exhaust gas recirculation unit is shut down; the methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; the hydrogen production unit is turned on and controlled to operate using a combination of electric heating and waste heat from the exhaust gas; the hydrogen delivery control unit is turned on to supply hydrogen to the intake system and simultaneously pressurize and deliver the hydrogen to the pre-combustion chamber 3, so that the pre-combustion chamber 3 is in active working mode.

[0049] When the power change rate is lower than 8% / s to 12% / s of the engine's rated power, and the engine's current actual output torque is not lower than 80% of the external characteristic torque at the current speed, the current operating condition is determined to be a high-load condition, and the main control unit executes the following control commands: Turn on the exhaust gas recirculation unit; control the methanol supply unit to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; turn on the hydrogen production unit and control the hydrogen production unit to operate only by using the waste heat of the exhaust gas; turn on the hydrogen delivery control unit to supply hydrogen to the intake system, and at the same time pressurize and deliver the hydrogen to the pre-combustion chamber 3, so that the pre-combustion chamber 3 is in active working mode.

[0050] When the power change rate is less than 8% / s to 12% / s of the engine's rated power, and the engine's current actual output torque is less than 80% of the external characteristic torque at the current speed, the current operating condition is determined to be a low-load condition, and the main control unit executes the following control commands: The exhaust gas recirculation unit is shut down; the methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; the hydrogen production unit is turned on and controlled to operate using a combination of electric heating and waste heat from the exhaust gas; the hydrogen delivery control unit is turned on to supply hydrogen to the intake system, while simultaneously cutting off the path for actively supplying hydrogen to the pre-combustion chamber 3, so that the pre-combustion chamber 3 is in a passive operating mode.

[0051] It should be noted that the main control unit controls the opening and closing of each functional unit by controlling the corresponding control valves or control components. This part has been described in detail in the above embodiment of the alcohol-hydrogen fusion engine pre-combustion chamber system, and will not be repeated here.

[0052] This invention enables the coordinated control of various functional units under different operating conditions, eliminating the need for complex plasma generators and multiple exhaust gas circuits. It can adopt corresponding control strategies for combustion problems under different operating conditions, taking into account cold start reliability, high and low load combustion stability, transient response capability and energy utilization efficiency, effectively improving the reliability and overall performance of the entire machine.

[0053] While various embodiments of the invention have been shown and described in this specification, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention.

Claims

1. A pre-combustion chamber system for an alcohol-hydrogen fusion engine, comprising an engine body, characterized in that, The engine block contains a main combustion chamber and a pre-combustion chamber that are interconnected, with a spark plug installed in the pre-combustion chamber; it also includes: A methanol supply unit is connected to the intake system and hydrogen production unit of the engine body, respectively, and is used to controllably supply liquid methanol fuel to the intake system and / or hydrogen production unit. The hydrogen production unit is located outside the pre-combustion chamber and connected to the exhaust system of the engine body. It is used to receive liquid methanol fuel and heat and crack it to produce hydrogen. A hydrogen delivery control unit is connected to the hydrogen production unit, the pre-combustion chamber, and the air intake system, respectively, for controllably delivering hydrogen output from the hydrogen production unit to the air intake system, and controllably pressurizing and delivering hydrogen to the pre-combustion chamber. The exhaust gas recirculation unit connects the intake and exhaust systems of the engine block to controllably reintroduce exhaust gases discharged from the engine block into the cylinders of the engine block. The main control unit is communicatively connected to the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and exhaust gas recirculation unit. It is used to collect the operating parameters of the engine body and determine the current operating condition. Based on the operating condition, it adjusts the methanol supply path, hydrogen supply path, pre-combustion chamber operating mode, hydrogen production unit heating method, and exhaust gas recirculation unit on / off status accordingly.

2. The pre-combustion chamber system for an alcohol-hydrogen fusion engine according to claim 1, characterized in that, The methanol supply unit includes a methanol storage container, a first methanol control valve, and a second methanol control valve. The output of the methanol storage container is divided into two paths: one path connects to the methanol nozzle in the air intake system via the first methanol control valve, and the other path connects to the feed end of the hydrogen production unit via the second methanol control valve. The main control unit is communicatively connected to the first methanol control valve and the second methanol control valve.

3. The pre-combustion chamber system for an alcohol-hydrogen fusion engine according to claim 2, characterized in that, The hydrogen delivery control unit includes a hydrogen storage container, a first hydrogen control valve, and a second hydrogen control valve. The input end of the hydrogen storage container is connected to the output end of the hydrogen production unit, and the output end is divided into two paths: one path is connected to the gas inlet system via the first hydrogen control valve, and the other path is connected to the pre-combustion chamber via the second hydrogen control valve. The main control unit is communicatively connected to the first hydrogen control valve and the second hydrogen control valve.

4. The pre-combustion chamber system for an alcohol-hydrogen fusion engine according to claim 3, characterized in that, The hydrogen production unit includes a methanol cracker, which is equipped with an electric heating element and a waste gas heating component. The waste gas heating component is connected to the exhaust system. The main control unit selectively uses electric heating and / or waste heat from the waste gas to heat the methanol cracker.

5. The pre-combustion chamber system for an alcohol-hydrogen fusion engine according to claim 4, characterized in that, The exhaust gas recirculation unit includes an exhaust gas pipeline and an exhaust gas control valve installed on the exhaust gas pipeline; one end of the exhaust gas pipeline is connected to the exhaust system and the other end is connected to the intake system; the exhaust gas control valve is communicatively connected to the main control unit and is used to control the opening and closing of the exhaust gas pipeline.

6. A control method for the pre-combustion chamber system of an alcohol-hydrogen fusion engine according to any one of claims 1-5, characterized in that, The control method is executed by the main control unit and includes the following steps: Obtain the current operating parameters of the engine body, including engine speed, actual output torque, coolant temperature, and power change rate; The current operating condition of the engine is determined based on the operating parameters, which include cold start and warm-up conditions, acceleration conditions, high load conditions, and low load conditions. Based on the current operating conditions, corresponding adaptive control commands are generated to coordinate the operation of the methanol supply unit, hydrogen production unit, hydrogen delivery control unit, and waste gas recirculation unit.

7. The control method according to claim 6, characterized in that, When the engine speed is not higher than the idle speed range, the actual output torque of the engine is not higher than 5% of the external characteristic torque at the current speed, and the coolant temperature is not higher than 50℃, the current operating condition is determined to be cold start and warm-up condition, and the main control unit executes the following control instructions: Shut down the exhaust gas recirculation unit; The methanol supply unit is controlled to cut off the supply of liquid methanol to the intake system and start the supply of liquid methanol to the hydrogen production unit. Turn on the hydrogen production unit and control the hydrogen production unit to operate only by electric heating. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, while the path for actively supplying hydrogen to the pre-combustion chamber is cut off, putting the pre-combustion chamber into a passive working mode.

8. The control method according to claim 6, characterized in that, When the power change rate is not less than 8% / s to 12% / s of the engine's rated power, the current operating condition is determined to be an acceleration condition, and the main control unit executes the following control instructions: Shut down the exhaust gas recirculation unit; The methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; Turn on the hydrogen production unit and control the hydrogen production unit to operate by using a combination of electric heating and waste heat from the exhaust gas. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, and at the same time, the hydrogen is pressurized and delivered to the pre-combustion chamber, so that the pre-combustion chamber is in active working mode.

9. The control method according to claim 6, characterized in that, When the power change rate is lower than 8% / s to 12% / s of the engine's rated power, and the engine's current actual output torque is not lower than 80% of the external characteristic torque at the current speed, the current operating condition is determined to be a high-load condition, and the main control unit executes the following control instructions: Start the exhaust gas recirculation unit; The methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; Turn on the hydrogen production unit and control the hydrogen production unit to operate only by using the waste heat of the exhaust gas for heating. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, and at the same time, the hydrogen is pressurized and delivered to the pre-combustion chamber, so that the pre-combustion chamber is in active working mode.

10. The control method according to claim 6, characterized in that, When the power change rate is lower than 8% / s to 12% / s of the engine's rated power, and the engine's current actual output torque is lower than 80% of the external characteristic torque at the current speed, the current operating condition is determined to be a low-load condition, and the main control unit executes the following control instructions: Shut down the exhaust gas recirculation unit; The methanol supply unit is controlled to simultaneously supply liquid methanol to the intake system and the hydrogen production unit; Turn on the hydrogen production unit and control the hydrogen production unit to operate by using a combination of electric heating and waste heat from the exhaust gas. The hydrogen delivery control unit is activated to supply hydrogen to the intake system, while the path for actively supplying hydrogen to the pre-combustion chamber is cut off, putting the pre-combustion chamber into a passive working mode.

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