Hydrogen production device of high-power commercial ammonia hydrogen range extender and control method thereof

Abstract

The application provides a hydrogen production device of a high-power commercial ammonia hydrogen range extender and a control method thereof, and belongs to the technical field of vehicle power systems. The hydrogen production device comprises an ammonia fuel tank, an ammonia cracking heat exchanger, an EGR system, a battery pack, an ECU, an ammonia fuel engine, a generator, a flame arrester, a check valve and a rectifier. The tail gas of the engine first enters the tube side of the ammonia cracking heat exchanger to provide residual heat for the cracking of ammonia gas in the shell side. The ammonia liquid in the ammonia fuel tank is gasified and then enters the shell side of the ammonia cracking heat exchanger, and is cracked into hydrogen and nitrogen under the action of a catalyst and by using the residual heat of the tail gas. The ammonia hydrogen mixture generated by cracking is mixed with the EGR-cooled tail gas in a spiral mixing pipeline, and then is used to assist the combustion of the engine. The ammonia inflow and the tail gas backflow are controlled in real time by a PID algorithm module built in the ECU, so as to match the dynamic power demand of the range extender. The remaining tail gas is treated by a purification device and is discharged up to the standard, hydrogen gas does not need to be stored, the device can adapt to complex working conditions such as heavy load of commercial vehicles, the energy utilization rate is improved, and the emission is reduced.

Description

Technical Field

[0001] This invention belongs to the field of vehicle power system technology, and more specifically, relates to a hydrogen production device and control method for a high-power commercial ammonia-hydrogen range extender. Background Technology

[0002] The energy crisis and environmental pressures are significant challenges facing the development of commercial vehicles. Developing clean and efficient alternative fuel technologies is one of the key ways to address these issues. Hydrogen energy, as a clean energy source with zero carbon emissions, boasts high combustion efficiency and environmentally friendly byproducts. However, technological barriers to its storage and transportation limit its large-scale application in commercial vehicles.

[0003] Ammonia (NH3), as a hydrogen-rich carrier, is easily liquefied and convenient to store and transport. Its production and transportation systems are mature, making it an ideal medium for hydrogen energy storage and transportation. Ammonia cracking technology can produce hydrogen on-site during vehicle operation, avoiding the safety challenges associated with high-pressure hydrogen storage. However, traditional ammonia cracking systems often rely on independent heat sources, resulting in low energy utilization and poor adaptability to vehicle operating conditions, making it difficult to meet the demands of long-term continuous operation for commercial vehicles.

[0004] Therefore, there is an urgent need for an ammonia cracking hydrogen production system that can efficiently utilize the waste heat of engine exhaust and is adapted to the complex operating conditions of commercial vehicles, in order to overcome the problems of low ammonia hydrogen production efficiency, difficulty in hydrogen storage, and poor synergy with vehicle power systems in existing technologies. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a hydrogen production device and its control method for a high-power commercial ammonia-hydrogen range extender, thereby solving the technical problems of difficulty in ammonia ignition in ammonia fuel engines and difficulty in hydrogen storage during hydrogen combustion in the prior art.

[0006] The purpose and effectiveness of the hydrogen production device and its control method for a high-power commercial ammonia-hydrogen range extender of the present invention are achieved by the following specific technical means:

[0007] A hydrogen production device for a high-power commercial ammonia-hydrogen range extender includes an ammonia fuel tank, an ammonia cracking heat exchanger, an EGR system, a battery pack, an ECU, an ammonia fuel engine, a generator, a flame arrester, a check valve, and a rectifier.

[0008] The ammonia cracking heat exchanger is used for ammonia cracking reaction and is connected in series with the EGR system through heat-resistant alloy tubes. The outlet of the ammonia fuel tank is connected to the shell-side inlet of the ammonia cracking heat exchanger through a pipe equipped with a proportional solenoid valve and a nozzle. Its shell-side outlet is connected to the spiral mixing pipe through a buffer chamber and a flame arrester. The tube-side inlet of the ammonia cracking heat exchanger is connected to the exhaust pipe of the engine through a flange. The tube-side outlet is connected to the inlet of the EGR system used for exhaust gas cooling through a pipe. The outlet of the EGR system is connected to the spiral mixing pipe through an EGR flow control valve.

[0009] The engine's intake pipe is connected to the outlet of a spiral mixing pipe via a one-way valve; the range extender assembly consists of the engine and the generator, and the generator's current output terminal is connected to the battery pack via a rectifier.

[0010] According to a preferred embodiment, the ammonia cracking heat exchanger is a shell-and-tube structure independent of the EGR system. The shell side of the ammonia cracking heat exchanger has a spiral wound structure with a nozzle at the inlet. Multiple baffles are uniformly arranged inside the shell side, and the baffles are fixedly connected to the inner wall of the shell side. The inner wall of the shell side and the surface of the baffles are coated with a ruthenium-based catalyst coating to form a catalyst bed. A temperature sensor and a thermocouple are installed inside the shell side. The thermocouple passes through the catalyst bed region in the middle of the shell side to detect the catalyst temperature.

[0011] According to a preferred embodiment, the engine's recirculated exhaust gas enters the tube side of an ammonia cracking heat exchanger through the exhaust pipe for initial heat release and exchange. The tube side outlet of the ammonia cracking heat exchanger is connected to an EGR system. The recirculated exhaust gas undergoes secondary cooling through the EGR system and is then connected to a spiral mixing pipe via an EGR flow control valve.

[0012] The shell-side outlet of the ammonia cracking heat exchanger is sequentially connected to a buffer chamber, a flame arrester, and a spiral mixing pipe. The buffer chamber is used to temporarily store a small amount of ammonia-hydrogen mixture. A pressure sensor is installed on the shell-side outlet pipe. The flame arrester is used to prevent flame backflow caused by high temperature. The inner wall of the spiral mixing pipe is provided with turbulence-inducing ridges, and its outlet is connected to the engine's intake pipe through a pipe equipped with a one-way valve.

[0013] According to a preferred embodiment, the battery pack adopts a high-capacity modular structure and is installed on the vehicle chassis. An electric heating element is wound around the outer wall of the casing, and the battery pack supplies power to the electric heating element of the ammonia cracking heat exchanger.

[0014] The ECU is connected via CAN bus to the proportional solenoid valve, temperature sensor, thermocouple, pressure sensor, EGR flow control valve, battery pack BMS system, engine speed sensor, and generator voltage regulator.

[0015] According to a preferred embodiment, the ECU has a built-in PID control algorithm module, which is used to dynamically adjust the opening degree of the proportional solenoid valve, the heating power of the electric heating element, and the opening degree of the EGR flow control valve based on the catalyst bed temperature detected by the thermocouple, the air-fuel mixture pressure detected by the pressure sensor, and the engine load signal.

[0016] According to a preferred embodiment, the ammonia cracking heat exchanger and the EGR system form a functionally independent series structure; the ammonia cracking heat exchanger is dedicated to using the waste heat of engine exhaust gas to crack ammonia to produce hydrogen, and the flow path of the ammonia-hydrogen mixture is as follows: shell side of the ammonia cracking heat exchanger, buffer chamber, flame arrester, spiral mixing pipe, and intake pipe.

[0017] The EGR system cools the recirculated exhaust gas passing through the tube side of the ammonia cracking heat exchanger. The flow path of the recirculated exhaust gas is as follows: engine exhaust pipe, ammonia cracking heat exchanger tube side, EGR system, EGR flow control valve, spiral mixing pipe.

[0018] According to a preferred embodiment, the spiral mixing pipe is used to enhance the mixing effect of hydrogen produced by ammonia cracking, uncracked ammonia, and the return exhaust gas cooled by the EGR system, so as to meet the high power requirements of ammonia fuel engines; the EGR flow control valve can dynamically adjust the exhaust gas return flow rate according to the engine load signal, thereby optimizing the volume ratio of the mixed gas.

[0019] According to a preferred embodiment, the catalyst bed is composed of a ruthenium-based catalyst coating and a baffle plate; wherein the ruthenium-based catalyst coating uses metallic ruthenium as the active component and porous α-Al2O3 as the carrier, the baffle plate has a fan-shaped structure with a central angle of 60° and is arranged at an inclination of 30° relative to the shell-side axis, and the catalyst coating on its surface is connected to the catalyst coating on the inner wall of the shell-side to form a continuous catalytic reaction channel.

[0020] A control method for a hydrogen production device using a high-power commercial ammonia-hydrogen range extender, applied to the aforementioned hydrogen production device using a high-power commercial ammonia-hydrogen range extender, includes the following steps:

[0021] Based on the ECU, the battery pack's charge data and the engine's coolant temperature data are obtained. When the charge data and coolant temperature data meet the preset indicators, the engine is started, and at the same time, the electric heating element of the ammonia cracking heat exchanger is controlled to start working, preheating the ruthenium-based catalyst coating to increase the temperature.

[0022] Real-time temperature data of the ruthenium-based catalyst coating is obtained based on thermocouples. When the real-time temperature data is greater than or equal to the preset active temperature of the catalyst, the preset active temperature is expressed as 350°C. Based on the ECU control of the proportional solenoid valve to open, ammonia gas enters the shell side of the ammonia cracking heat exchanger through the nozzle, exchanges heat with the tail gas in the tube side, and cracks to generate hydrogen and nitrogen under the action of the ruthenium-based catalyst coating.

[0023] Based on the vehicle load signal, the ECU adjusts the opening of the proportional solenoid valve and the flow control valve through a PID algorithm; based on the real-time temperature data of the ammonia cracking heat exchanger obtained by the temperature sensor, the ECU adjusts the heating power of the electric heating element based on the real-time temperature data, and adjusts the power of the ammonia cracking heat exchanger based on the battery pack power data.

[0024] According to a preferred embodiment, when the vehicle load signal indicates normal vehicle operation, the ECU uses a PID algorithm with catalyst bed temperature as the first feedback parameter, adjusts the heating power of the electric heating element as the proportional term of the PID control, and adjusts the opening of the proportional solenoid valve as the integral term of the PID control. When the temperature fluctuation exceeds ±5℃, the PID derivative term is triggered for correction. Based on the pressure data of the ammonia-hydrogen mixture obtained by the pressure sensor as the second feedback parameter, the opening of the EGR flow control valve is adjusted. When the pressure deviation exceeds ±0.02MPa, the opening of the proportional solenoid valve is dynamically corrected.

[0025] When the vehicle load signal indicates a heavy load or high-speed condition, the ECU calculates the required hydrogen supply and total volume of the mixture based on the engine load signal. It increases the opening of the proportional solenoid valve to increase the ammonia flow rate and the opening of the EGR flow control valve to increase the exhaust gas return flow rate through the PID algorithm. This increases the proportion of inert gas in the mixture. The ammonia-hydrogen mixture enters the spiral mixing pipe through the buffer chamber and is fully mixed with the return exhaust gas cooled by the EGR system before entering the engine for combustion and power generation. At the same time, it drives the generator to charge the battery pack.

[0026] When the temperature sensor detects that the exhaust gas temperature is lower than the preset active temperature, the ECU uses a PID algorithm to control the battery pack to supply power to the electric heating element to maintain the temperature of the ruthenium-based catalyst coating.

[0027] When the battery pack's charge level is below a preset threshold, the ammonia cracking heat exchanger maintains the minimum hydrogen production rate, the engine prioritizes driving the generator to charge the battery pack, and the EGR flow control valve maintains the minimum opening to keep the base mixing ratio stable.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. Clear functional zoning adapts to complex operating conditions. The ammonia cracking heat exchanger and EGR system are set as functionally independent series structures. The ammonia cracking heat exchanger uses the waste heat of high-temperature tail gas to complete the ammonia cracking hydrogen production, and the EGR system is used to cool the tail gas after heat exchange. This avoids the structural complexity and mutual interference problems caused by the integration of hydrogen production function and EGR system in traditional units. It enables each component of the unit to perform its own function, adapt to complex operating conditions such as heavy load and long-term continuous operation of commercial vehicles, and ensure stable operation.

[0030] 2. High energy efficiency and reduced energy waste: The ammonia cracking heat exchanger directly recovers the high-temperature waste heat from engine exhaust, using it as the driving energy for the ammonia cracking reaction and fully utilizing the heat from the engine exhaust. Simultaneously, the exhaust gas, cooled by the EGR system, flows back to the spiral mixing pipe to participate in the combustion process, achieving a cascaded utilization of exhaust waste heat from high-temperature cracking to low-temperature combustion. This not only reduces energy waste but also reduces NOx emissions. X emission.

[0031] 3. Excellent combustion stability: The turbulence-enhancing texture on the inner wall of the spiral mixing pipe strengthens the uniform mixing effect of the ammonia-hydrogen mixture produced by ammonia cracking and the recirculated exhaust gas, ensuring a balanced distribution of fuel and gas components. The introduction of hydrogen reduces the ignition energy requirement of ammonia, solving the problem of traditional ammonia ignition difficulties. Meanwhile, the inert gas components in the recirculated exhaust gas can effectively regulate the combustion rate and prevent excessive combustion. The synergistic effect of these three factors makes the combustion process more stable, adapting to the combustion characteristics of the engine and further improving combustion stability.

[0032] 4. Clean and reliable cold start: During the initial stage of vehicle startup, the battery pack supplies power to heat the ruthenium-based catalyst coating in the ammonia cracking heat exchanger through high-power electric heating elements, enabling the catalyst to quickly reach the activation temperature. The ammonia cracking reaction can be started without the need for auxiliary fuels such as gasoline. This cold start method achieves zero carbon emissions during the startup phase, meets environmental protection requirements, and eliminates the need for auxiliary fuel storage and supply structures, simplifying the overall structure of the device, reducing potential failures, and improving the operational reliability of the device.

[0033] 5. The ECU employs a closed-loop control strategy based on a PID algorithm, combined with real-time data acquired from thermocouples and pressure sensors. This allows for dynamic adjustment of the proportional solenoid valve opening, the power of the electric heating element, and the flow control valve opening. Simultaneously, the continuous reaction channel formed by the segmented catalyst bed ensures that hydrogen production precisely matches the dynamic changes in engine load. This control strategy effectively adapts to the varied operating conditions of commercial vehicles, ensuring that the system output always aligns with engine demands, thus guaranteeing the stability and reliability of the entire range extender unit. Attached Figure Description

[0034] Figure 1This is a schematic diagram of the hydrogen production device of a high-power commercial ammonia-hydrogen range extender in this invention;

[0035] Figure 2 This is a flowchart of the steps of a control method for a hydrogen production device using a high-power commercial ammonia-hydrogen range extender according to the present invention.

[0036] Figure 3 This is a schematic diagram of the framework of the PID control algorithm in this invention.

[0037] In the diagram, the correspondence between component names and drawing numbers is as follows:

[0038] 1. Ammonia fuel tank; 2. Ammonia cracking heat exchanger; 3. EGR system; 4. Exhaust pipe; 5. Inlet pipe; 9. Check valve; 11. Proportional solenoid valve; 12. Nozzle; 13. Baffle plate; 17. Electric heating element; 20. Spiral mixing pipe; 21. Buffer chamber; 22. EGR flow control valve. Detailed Implementation

[0039] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the technical solutions of the present invention, but should not be used to limit the scope of protection of the present invention.

[0040] Example:

[0041] As attached Figure 1 As shown:

[0042] This invention provides a hydrogen production device for a high-power commercial ammonia-hydrogen range extender, comprising an ammonia fuel tank 1, an ammonia cracking heat exchanger 2, an EGR system 3, a battery pack, an ECU, an ammonia fuel engine, a generator, a flame arrester, a one-way valve 9, and a rectifier. The ammonia fuel tank 1 stores liquid ammonia fuel and requires reserved space for refueling operations during installation to accommodate the refueling needs of commercial vehicles. The ammonia cracking heat exchanger 2 is specifically designed for the cracking reaction of ammonia gas and is connected in series with the EGR system 3 via heat-resistant alloy pipes. The outlet of the ammonia fuel tank 1 is sealed to the shell-side inlet of the ammonia cracking heat exchanger 2 via a pipeline equipped with a proportional solenoid valve 11, which controls the ammonia gas flow rate. The ammonia cracking heat exchanger 2... The inlet of the tube is fixedly connected to the end of the exhaust pipe 4 of the engine via a flange to ensure reliable and leak-free connection under high temperature and high frequency vibration environments. The high-temperature exhaust gas generated by engine combustion can be directly introduced into the tube. The outlet of the tube is connected to the inlet of the EGR system 3 for exhaust gas cooling via a pipeline. The EGR system 3 is a traditional water-cooled structure. The outlet of the EGR system 3 is connected to the spiral mixing pipe via an EGR flow control valve. The intake pipe 5 of the engine is connected to the outlet of the spiral mixing pipe 20 via a one-way valve 9. The one-way valve 9 can prevent the gas in the intake pipe 5 from flowing back to the spiral mixing pipe 20. The range extender assembly consists of the engine and the generator. The current output terminal of the generator is connected to the battery pack via a rectifier.

[0043] The ammonia cracking heat exchanger 2 is a shell-and-tube structure independent of the EGR system 3. It is connected in series with the EGR system 3 but physically separated. The shell side of the ammonia cracking heat exchanger 2 adopts a spiral wound structure to extend the flow path of ammonia gas in the shell side. A nozzle 12 is provided at the inlet. Ammonia gas is delivered to the nozzle 12 by a proportional solenoid valve 11 and then injected into the shell side. Multiple baffles 13 are evenly arranged inside the shell side. The baffles 13 are fixedly connected to the inner wall of the shell side and are arranged in a fan shape with an inclination relative to the shell side axis. Both their surfaces and the inner wall of the shell side are coated with a ruthenium-based catalyst coating. Together, they form a continuous catalyst bed. The ruthenium-based catalyst coating should be uniformly applied and firmly adhered without peeling. After assembly, the entire unit must pass an airtightness test to ensure sealing performance. The baffle 13 can change the flow direction of ammonia gas and expand the reaction contact area through the catalyst coating on its surface. A temperature sensor and a thermocouple are installed in the shell side. The temperature sensor is used to detect the overall temperature in the shell side, and the thermocouple passes through the catalyst bed area in the middle of the shell side, specifically for detecting the real-time temperature of the catalyst bed. The detection data is transmitted to the ECU in real time.

[0044] In this embodiment, the ammonia cracking heat exchanger 2 and the EGR system 3 are configured as functionally independent series structures, and their functions are isolated by physical separation. When the vehicle is running, the high-temperature recirculation exhaust gas discharged from the engine exhaust pipe 4 first enters the tube side of the ammonia cracking heat exchanger 2. The released high-temperature waste heat is transferred to the ammonia gas in the shell side. The ammonia cracking heat exchanger 2 uses this high-temperature waste heat to drive the ammonia gas to undergo a cracking reaction on the surface of the catalyst bed, generating a mixture containing hydrogen and nitrogen. After the recirculation exhaust gas is cooled by heat exchange in the ammonia cracking heat exchanger 2, it enters the EGR system 3 for secondary cooling, avoiding the structural complexity and mutual interference problems caused by the integration of hydrogen production function and EGR system 3 in traditional devices. The cooled recirculation exhaust gas flows to the spiral mixing pipe 20 according to the operating conditions, mixes with the mixture generated by ammonia cracking, and then enters the engine for combustion through the intake pipe 5. This structure allows each component of the device to focus on its own function. The ammonia cracking heat exchanger 2 efficiently completes hydrogen production, and the EGR system 3 stably cools the exhaust gas, adapting to complex operating conditions such as heavy load and long-term continuous operation of commercial vehicles, ensuring the stable operation of the entire hydrogen production device and range extender system.

[0045] The ammonia cracking heat exchanger 2 and the EGR system 3 form a functionally independent series structure through heat-resistant alloy tubes. Their functions are isolated through physical separation. The tube side of the ammonia cracking heat exchanger 2 is used to heat the catalyst, while the EGR system 3 is used to cool the exhaust gas after heat exchange. The components do not interfere with each other, ensuring the stable operation of each function. The ammonia cracking heat exchanger 2 is specifically designed to utilize the high-temperature waste heat carried by the engine exhaust gas for ammonia cracking to produce hydrogen. When the engine is running, the high-temperature exhaust gas produced by combustion is continuously discharged from the engine's exhaust pipe 4 and directly enters the tube side of the ammonia cracking heat exchanger 2 through the pipe. As the exhaust gas flows within the tube side, it dissipates the heat carried by the catalyst. High-temperature waste heat is transferred to the ammonia gas in the shell side of the ammonia cracking heat exchanger 2 through the tube wall, providing sufficient heat support for the ammonia cracking reaction. After the exhaust gas releases waste heat, its temperature gradually decreases and then continues to flow into the EGR system 3 along the pipeline, completing the first stage of waste heat utilization. The EGR system 3 only cools the low-temperature exhaust gas after heat exchange in the ammonia cracking heat exchanger 2. The exhaust gas temperature is reduced to a range that is favorable for engine combustion through the internal cooling channel. After cooling, the exhaust gas is introduced into the spiral mixing pipe 20 through the pipeline equipped with the EGR flow control valve to participate in the subsequent combustion process. The exhaust gas return flow rate can be flexibly adjusted according to the engine operating conditions.

[0046] In this embodiment, the ammonia cracking heat exchanger 2 directly recovers the high-temperature waste heat carried by the engine exhaust gas, which provides the necessary driving energy for the cracking reaction of ammonia on the catalyst bed surface, reducing the energy consumption of the hydrogen production process. At the same time, the low-temperature waste heat carried by the return exhaust gas after being cooled by the EGR system 3, along with its own inert gas components, is utilized and returned to the spiral mixing pipe 20, where it is fully mixed with the ammonia-hydrogen mixture generated by ammonia cracking. This allows the residual heat in the exhaust gas to participate in the combustion process, and the combustion rate is regulated by the inert gas. This achieves the cascade utilization of exhaust gas waste heat from high-temperature driving ammonia cracking to low-temperature assisted combustion, reducing energy loss and improving the completeness of fuel combustion, thereby improving the overall thermal efficiency of the entire range extender system.

[0047] The high-temperature exhaust gas generated during engine operation is discharged from the exhaust pipe 4 and directly enters the tube side of the ammonia cracking heat exchanger 2. During its flow within the tube side, it releases high-temperature waste heat, efficiently exothermicly exchanging heat with the ammonia gas in the shell side, providing the necessary heat for the ammonia cracking reaction. After heat exchange, the exhaust gas temperature decreases and it continuously flows into the EGR system 3. The EGR system 3 performs secondary cooling on the incoming exhaust gas. The cooled exhaust gas is then connected to the spiral mixing pipe 20 via a pipe equipped with an EGR flow control valve 22. The EGR flow control valve 22 can adjust the flow rate of the returning exhaust gas according to the engine operating conditions. The shell-side outlet of the ammonia cracking heat exchanger 2 is connected to the buffer chamber via a pipe. The buffer chamber 21 and the spiral mixing pipe 20 have a certain volume inside to temporarily store a small amount of ammonia-hydrogen mixture generated by ammonia cracking reaction, so as to avoid excessive fluctuations in the flow rate of the mixture. The pressure sensor installed on the shell-side outlet pipe detects the pressure data of the ammonia-hydrogen mixture in real time, and the detection results are synchronously transmitted to the ECU for dynamic adjustment. The inner wall of the spiral mixing pipe 20 is integrally formed with multiple turbulence ridges, which are spirally distributed along the inner wall of the pipe. The outlet of the spiral mixing pipe 20 is connected to the intake pipe 5 of the engine through a pipe equipped with a one-way valve 9. The one-way valve 9 can prevent the gas in the intake pipe 5 from flowing back into the mixing pipe, ensuring the stability of the gas flow direction.

[0048] In this embodiment, the ammonia-hydrogen mixture generated by ammonia cracking is stably output through the buffer chamber 21 and then enters the spiral mixing pipe 20. Simultaneously, a portion of the return tail gas cooled by the EGR system 3 also enters the mixing pipe through the EGR flow control valve 22. The turbulence-inducing texture on the inner wall of the pipe alters the flow trajectories of the two gases, breaking the stratified flow state and increasing the contact area and contact time between the ammonia-hydrogen mixture and the return tail gas, thus enhancing the uniform mixing effect and ensuring a balanced distribution of fuel and gas components within the pipe. The hydrogen contained in the ammonia-hydrogen mixture reduces the ignition energy of the ammonia. This design effectively solves the problem of difficult ignition of traditional ammonia gas, making the air-fuel mixture easier to ignite. The inert gas components in the recirculated exhaust gas slow down the combustion reaction rate, preventing the combustion process from being too violent and causing engine instability. The easy ignition characteristics of the ammonia-hydrogen mixture, the stable combustion effect of the recirculated exhaust gas, and the uniform mixing effect of the spiral mixing pipe 20 work together to make the engine combustion process more stable. This makes it suitable for the high-flow combustion requirements and operating characteristics of high-power engines, further improving the stability and reliability of engine combustion and reducing the impact of combustion fluctuations on engine components.

[0049] The battery pack adopts a high-capacity modular structure and is installed in the vehicle chassis. The modular design allows for flexible assembly and combination according to vehicle space and energy requirements, while also facilitating later maintenance and replacement. Its high capacity allows for the storage of sufficient electrical energy to meet the auxiliary power needs during cold start preheating, engine starting, and system operation. Electric heating elements 17 are tightly wound around the outer wall of the ammonia cracking heat exchanger 2. These elements directly transfer heat to the shell side, achieving rapid heating of the catalyst bed inside. The battery pack establishes stable electrical connections with the electric heating elements 17, the engine's starter motor, and the ECU via copper busbars. The copper busbars have low resistance characteristics, ensuring efficient power transmission. The system supplies power to the electric heating element 17 for catalyst preheating, to the starter motor for engine starting, and to the ECU to ensure continuous and stable operation of the control unit. The ECU establishes a communication link with each component via the CAN bus, enabling data exchange and command transmission with the proportional solenoid valve 11, temperature sensor, thermocouple, pressure sensor, EGR flow control valve 22, battery pack BMS system, engine speed sensor, and generator voltage regulator. It receives temperature, pressure, and power data detected by each sensor in real time and sends control commands to adjust the operating status of relevant components, ensuring that the entire hydrogen production unit and engine system work together.

[0050] In this embodiment, during the vehicle's cold start phase, the engine coolant temperature is low and the catalyst has not reached its activation temperature. At this time, the ECU detects the catalyst bed temperature via a thermocouple. The ECU drives the electric heating element 17 to heat the catalyst at an initial 50% output through a proportional circuit, controlling the heating rate at 5°C / s to avoid overheating of the catalyst. When the temperature is lower than the preset activation threshold, the battery pack supplies power to the electric heating element 17 through the copper busbar. After being energized, the electric heating element 17 generates heat and transfers it to the shell side of the ammonia cracking heat exchanger 2, thereby heating the ruthenium-based catalyst coating on the inner wall of the shell side and the surface of the baffle 13, allowing the catalyst to rapidly activate in a short time. The device quickly reaches the active temperature required for the cracking reaction. The entire preheating process does not require auxiliary fuels such as gasoline or diesel. It can start the ammonia cracking reaction solely using the electrical energy stored in the battery pack. This cold start method avoids carbon emissions from the combustion of auxiliary fuels, achieving zero carbon emissions during the start-up phase, which meets environmental protection requirements. At the same time, it eliminates the need for auxiliary fuel storage tanks, delivery pipelines, injection devices, and other related structures, reducing the number of parts in the device, simplifying the overall structural layout, and lowering the risk of the device failing to start or malfunctioning due to auxiliary fuel supply system failures. This further improves the operational reliability and ease of maintenance of the device.

[0051] The ECU is installed in a high-level shockproof and waterproof box in the engine compartment. After power-on, the PID control algorithm parameters are initialized and calibrated to ensure that the accuracy of temperature and pressure control meets the design requirements. The ECU has a built-in PID control algorithm module, which receives catalyst bed temperature data detected by thermocouples, ammonia-hydrogen mixture pressure data detected by pressure sensors, and engine load signals in real time via the CAN bus. At the same time, it combines the power data transmitted by the battery pack BMS system and the exhaust gas temperature data fed back by the temperature sensor to construct a multi-parameter collaborative closed-loop control logic, which is used to dynamically adjust the opening degree of the proportional solenoid valve 11, the heating power of the electric heating element 17, and the opening degree of the EGR flow control valve 22. Thermocouples continuously monitor the real-time temperature of the catalyst bed. After the data is synchronously transmitted to the ECU, the PID algorithm module compares it with a preset active temperature range. When the temperature is below the lower limit of the range, the heating power of the electric heating element 17 is increased; when the temperature is above the upper limit, the heating power is decreased. Temperature fluctuations are dynamically corrected through the proportional, integral, and derivative terms of the PID algorithm. The proportional term is adjusted based on the real-time deviation between the current catalyst bed temperature detected by the thermocouple and the preset active temperature range of 350–500℃. The deviation value directly determines the adjustment intensity. If the current temperature is below the lower limit, the larger the deviation, the more directly the proportional term drives the electric heating element 17 to increase the heating power. If the temperature is above the upper limit, the larger the deviation, the more promptly the proportional term causes the electric heating element 17 to decrease the heating power, quickly responding to temperature deviations to initially reduce the fluctuation range. The integral term focuses on the cumulative effect of temperature deviation. When the temperature continuously deviates to one side of the range, such as being slightly below the lower limit or slightly above the upper limit for a long period, even if the proportional term... When residual deviations remain after adjustment, the integral term will continue to accumulate the deviation value and simultaneously adjust the opening degree of the proportional solenoid valve 11. When the temperature is consistently low, the opening degree will be slowly increased to increase the ammonia flow rate, supplementing the heat through the exothermic reaction. When the temperature is consistently high, the opening degree will be slowly decreased to reduce the ammonia flow rate and reduce the exothermic reaction intensity, until the accumulated deviation is completely eliminated, preventing the temperature from deviating from the range for a long time. The derivative term will make predictive adjustments based on the rate and trend of temperature change. By calculating the slope of temperature fluctuations in real time, it will determine the speed of temperature change and the next step. If the rate of temperature rise is detected to be too fast, the derivative term will reduce the heating power of the electric heating element 17 in advance. If the rate of temperature drop is detected to be too fast, the derivative term will increase the heating power of the electric heating element 17 in advance. By predicting the trend, it will suppress large temperature fluctuations and avoid overshoot or lag. The three terms work together to form a closed-loop correction, ensuring that the catalyst bed temperature is always stable within the active range of 350-500℃, providing continuous and stable temperature conditions for the ammonia cracking reaction.

[0052] The pressure sensor collects real-time mixed gas pressure data at the shell-side outlet of the ammonia cracking heat exchanger 2. The ECU compares this data with the intake pressure required by the engine under current operating conditions and adjusts the opening of the EGR flow control valve 22 to change the exhaust gas return flow. At the same time, it dynamically corrects the opening of the proportional solenoid valve 11 to ensure that the mixed gas pressure matches the engine intake demand. The engine load signal directly reflects the vehicle's operating status. The ECU calculates the required hydrogen supply based on this signal and controls the ammonia flow rate by adjusting the opening of the proportional solenoid valve 11, thereby changing the hydrogen production rate.

[0053] In this embodiment, the ECU employs a closed-loop control strategy based on a PID algorithm, combined with real-time feedback data obtained from thermocouples and pressure sensors. This allows for rapid response to changes in various parameters, dynamically adjusting the opening of the proportional solenoid valve 11 to control the ammonia flow rate, adjusting the power of the electric heating element 17 to stabilize catalyst activity, and adjusting the opening of the EGR flow control valve 22 to optimize exhaust gas recirculation. Simultaneously, a segmented catalyst bed composed of a ruthenium-based catalyst coating and fan-shaped baffles 13, with the baffles 13 arranged at an angle to form a continuous reaction channel, ensures a more uniform ammonia cracking reaction, enabling dynamic matching of hydrogen production to the engine load. The PID algorithm maintains all adjustment parameters within a stable range during normal vehicle operation, ensuring a balanced air-fuel mixture and stable combustion. When the vehicle enters heavy-load or high-speed operation, the engine load increases, and the PID algorithm rapidly increases the opening of the proportional solenoid valve 11 to increase ammonia flow and hydrogen production rate. Simultaneously, it increases the opening of the EGR flow control valve 22 to increase exhaust gas return flow and optimize the proportion of inert gases in the air-fuel mixture. When the exhaust gas temperature is low or the battery charge is insufficient, the PID algorithm coordinates the power supply status of the electric heating element 17 and the opening of the proportional solenoid valve 11 to ensure a balance between hydrogen production and charging needs. This control strategy can fully adapt to various operating conditions of commercial vehicles, such as normal driving, heavy-load hill climbing, and high-speed cruising. Through real-time feedback and dynamic adjustment, it ensures that hydrogen production, air-fuel mixture ratio, and catalyst activity remain consistent with the engine's real-time requirements. Furthermore, combined with the reaction stability of the continuous reaction channel, it reduces system fluctuations, ensuring stable and reliable operation of the entire range extender under different conditions.

[0054] The spiral mixing pipe 20 is a mixing component for ammonia-hydrogen mixture and reflux exhaust gas. Hydrogen and incompletely cracked ammonia generated in the shell side of the ammonia cracking heat exchanger 2 are temporarily stabilized in the buffer chamber 21 and then continuously flow into the spiral mixing pipe 20. At the same time, part of the reflux exhaust gas, after being cooled by the EGR system 3, also enters the spiral mixing pipe 20 after being regulated by the EGR flow control valve 22. The turbulence-causing ridges integrally formed on the inner wall of the spiral mixing pipe 20 are spirally distributed along the pipe axis, which can change the flow trajectory of the three gases, break the gas stratification flow state, prolong the contact time of the gases in the pipe, and expand the contact area, thereby enhancing the uniform mixing effect of hydrogen, uncracked ammonia and reflux exhaust gas, ensuring that the components in the mixture are evenly distributed, and continuously providing a stable fuel supply to the engine, adapting to the high-flow fuel demand of the engine under different operating conditions, and avoiding combustion fluctuations caused by uneven mixture supply. The EGR flow control valve 22 is connected to the ECU via a CAN bus and receives engine load signals in real time. When the vehicle is under heavy load, high speed, or other high-load conditions, the engine load signal triggers the EGR flow control valve 22 to increase its opening and increase the amount of exhaust gas returning to the engine. When the vehicle is under low load conditions, such as idling or low speed, the EGR flow control valve 22 decreases its opening and reduces the exhaust gas return flow. By dynamically adjusting the exhaust gas return flow, the volume ratio of inert gas, hydrogen, and ammonia in the gas mixture is optimized, ensuring that the combustion characteristics of the gas mixture are always adapted to the current engine operating conditions, thus guaranteeing combustion efficiency and stability.

[0055] The catalyst bed is the region for ammonia cracking reaction, composed of a ruthenium-based catalyst coating and baffle 13. The ruthenium-based catalyst coating uses metallic ruthenium as the active component, possessing highly efficient catalytic performance for ammonia cracking. Using porous α-Al₂O₃ as a carrier, the porous structure increases the specific surface area of ​​the catalyst, providing sufficient active sites for the ammonia cracking reaction and improving the reaction rate. The baffle 13 has a fan-shaped structure with a central angle of 60°, and is arranged at a 30° inclination relative to the shell-side axis of the ammonia cracking heat exchanger 2. This arrangement alters the flow path of ammonia within the shell side, extending its residence time in the catalyst bed. Simultaneously, the ruthenium-based catalyst coating on the surface of the baffle 13 connects with the catalyst coating on the inner wall of the shell side, forming a continuous catalytic reaction channel without dead zones. This allows ammonia to uniformly contact the catalyst during flow, avoiding incomplete local reactions and ensuring efficient and stable ammonia cracking reaction, continuously producing sufficient hydrogen to meet engine requirements.

[0056] Please see as follows Figure 2 and Figure 3 As shown, this application also provides a control method for a hydrogen production device using a high-power commercial ammonia-hydrogen range extender, applied to the aforementioned hydrogen production device using a high-power commercial ammonia-hydrogen range extender, comprising the following steps:

[0057] S10: Based on the ECU, the battery pack's power data and the engine's water temperature data are obtained. When the power data and water temperature data meet the preset indicators, the engine is started. At the same time, the electric heating element 17 of the ammonia cracking heat exchanger 2 is controlled to start working to preheat the ruthenium-based catalyst coating and increase the temperature.

[0058] Specifically, the ECU receives and judges real-time battery pack charge data and engine coolant temperature data to determine whether the data meet preset indicators. These indicators are: the battery pack charge is not lower than the minimum charge threshold required to support the starter motor in starting the engine and the electric heating element 17 in continuous preheating; and the engine coolant temperature is lower than the minimum coolant temperature threshold required for normal engine operation. After receiving the charge data transmitted from the battery pack's BMS system and the coolant temperature data from the engine coolant temperature sensor, the ECU first compares the real-time battery pack charge data with the preset charge threshold to confirm whether the charge can simultaneously meet the instantaneous energy consumption of the starter motor and the continuous energy demand of the electric heating element 17 after startup. Then, it compares the real-time engine coolant temperature data with the preset coolant temperature threshold to determine whether the engine is in a low-temperature standby state. In operation, the ECU determines that the battery pack has sufficient power to support the simultaneous operation of the electric heating element 17 and the starter motor only when the battery pack charge data reaches the preset charge threshold and the engine coolant temperature data is lower than the preset coolant temperature threshold. If the battery pack charge does not reach the preset threshold, the ECU will prioritize controlling the engine starter motor to drive the generator to charge the battery pack until the charge reaches the target level before starting the electric heating element 17. If the engine coolant temperature is higher than the preset coolant temperature threshold, it is only necessary to confirm that the battery pack charge is up to the target level before starting, avoiding starting failure or low preheating efficiency due to insufficient power. After the engine starts, it begins to run initially to prepare for the subsequent generation of high-temperature exhaust gas and to drive the generator to charge. The preheating process of the electric heating element 17 continues until the catalyst temperature reaches the preset activity standard, ensuring that the ammonia cracking reaction can start quickly.

[0059] S11: Real-time temperature data of the ruthenium-based catalyst coating is obtained based on thermocouples. When the real-time temperature data is greater than or equal to the preset active temperature of the catalyst, the preset active temperature is expressed as 350℃. Based on the ECU control, the proportional solenoid valve 11 is opened, and ammonia gas is atomized through nozzle 12 and enters the shell side of the ammonia cracking heat exchanger 2 to exchange heat with the tail gas in the tube side. Under the action of the ruthenium-based catalyst coating, it is cracked to generate hydrogen and nitrogen.

[0060] Specifically, the thermocouple continuously monitors the catalyst temperature and provides real-time feedback to ensure that the proportional solenoid valve 11 is only opened after the temperature reaches the target level. This prevents fuel waste or abnormal mixture ratios caused by the ineffective cracking of ammonia at low temperatures. The nozzle 12 atomizes the ammonia, increasing the contact area between the ammonia and the catalyst coating, while also improving the heat exchange efficiency with the exhaust gas. This allows the ammonia to quickly reach the conditions required for the cracking reaction. The hydrogen generated from the cracking process serves as the core fuel component, and together with the incompletely cracked ammonia and nitrogen, it forms a mixture suitable for engine combustion, providing an energy source for the engine.

[0061] S12: Based on the vehicle load signal, the ECU adjusts the opening of the proportional solenoid valve 11 and the flow control valve 22 through the PID algorithm; based on the real-time exhaust gas data obtained by the temperature sensor, the ECU adjusts the heating power of the electric heating element 17 based on the real-time exhaust gas data, and adjusts the power of the ammonia cracking heat exchanger 2 based on the power data.

[0062] Specifically, the vehicle load signal reflects the vehicle's current driving status. The ECU adjusts the opening of the proportional solenoid valve 11 and the EGR flow control valve 22 to match the hydrogen production and air-fuel mixture ratio with the engine's power demand, preventing insufficient fuel supply or incomplete combustion when the load changes. The exhaust gas data fed back by the temperature sensor provides a basis for adjusting the power of the electric heating element 17. Based on the real-time exhaust gas temperature data collected by the temperature sensor, the ECU transmits the data to the ECU. When the exhaust gas temperature is lower than the preset value, causing the catalyst temperature to drop, the ECU increases the heating power of the electric heating element 17 to supplement the heat. When the temperature is sufficient, the power of the electric heating element 17 is appropriately reduced to decrease power consumption; the catalyst temperature is kept stable within the active range to ensure the continuous and efficient cracking reaction. The hydrogen production power of the ammonia cracking heat exchanger 2 is adjusted based on the battery pack power data. Based on the real-time power data of the battery pack, when the power data is lower than the preset threshold, the ECU controls the ammonia cracking heat exchanger 2 to reduce the hydrogen production power to maintain the minimum hydrogen production rate to ensure the basic operation of the engine. When the power data is sufficient, the normal hydrogen production power is maintained or the hydrogen production efficiency is increased according to the load demand; thus achieving a dynamic balance between hydrogen production demand and charging demand, adapting to the changing driving conditions of commercial vehicles.

[0063] During actual vehicle operation, the ECU first detects the battery pack's charge level and the engine's coolant temperature. When it detects that the battery pack has sufficient charge and the engine coolant temperature is low, the ECU controls the battery pack to supply power to the starter motor, starting the engine. Simultaneously, it controls the electric heating element 17 on the outer wall of the ammonia cracking heat exchanger 2 to immediately operate, preheating the catalyst coating on the inner wall of the shell and the surface of the baffle 13. Thermocouples installed in the catalyst bed of the ammonia cracking heat exchanger 2's shell side monitor the catalyst temperature in real time and transmit the data to the ECU. When the temperature rises to the catalyst activity lower limit of 350℃, the ECU controls the proportional solenoid valve. When 11 is turned on, liquid ammonia in the ammonia fuel tank 1 is transported to the shell-side inlet of the ammonia cracking heat exchanger 2 through the pipeline. After being atomized by the nozzle 12, it enters the shell side and exchanges heat with the exhaust gas discharged from the engine in the tube side. Under the action of the catalyst, it is cracked to generate hydrogen and nitrogen. When the pressure sensor on the shell-side outlet pipeline of the ammonia cracking heat exchanger 2 detects that the shell-side outlet pressure is stable and the thermocouple shows that the catalyst temperature is maintained in the range of 300-500°C, the engine fuel mode is switched to ammonia-hydrogen mixed fuel. The output power of the electric heating element 17 is dynamically adjusted by the ECU according to the PID control law to maintain the catalyst within the active temperature range.

[0064] When the vehicle load signal indicates normal vehicle operation, the ECU continuously receives catalyst bed temperature data transmitted by thermocouples via the CAN bus. This data is used as the first feedback parameter and input to the built-in PID control algorithm module. The proportional term of the PID control adjusts the heating power of the electric heating element 17, directly adjusting the heat output according to the temperature deviation to quickly respond to temperature changes and ensure the catalyst temperature remains stable within the 350–500°C range. The integral term of the PID control adjusts the opening of the proportional solenoid valve 11, gradually eliminating accumulated temperature deviations to stabilize the ammonia flow rate and prevent fluctuations in ammonia supply from affecting the cracking efficiency. When the ECU detects a catalyst bed temperature fluctuation exceeding ±5°C, it triggers P... The differential term of the ID control is corrected in real time to prevent the temperature from deviating from the preset active range and causing abnormal cracking reaction. At the same time, the ECU receives the pressure data of the ammonia-hydrogen mixture detected by the pressure sensor and uses it as the second feedback parameter. Combined with the current engine speed and throttle opening, it calculates the target pressure value corresponding to the current intake air demand. By adjusting the opening of the EGR flow control valve 22 connected to the outlet pipe of EGR system 3, the amount of exhaust gas returning is changed, thereby adjusting the mixture pressure. When the deviation between the actual pressure and the target pressure is detected to exceed ±0.02MPa, the opening of the proportional solenoid valve 11 is dynamically corrected to ensure that the ammonia-hydrogen mixture pressure always matches the engine intake air demand and maintains a stable combustion process.

[0065] When the vehicle load signal indicates heavy load or high-speed operation, the ECU obtains real-time load signals through the engine speed sensor and throttle position sensor. Combined with a preset power demand mapping relationship, it accurately calculates the required hydrogen supply and total mixture volume under the current operating conditions. Simultaneously, the ECU's built-in PID control algorithm module starts, continuously accumulating adjustments through the integral stage to gradually increase the opening of the proportional solenoid valve 11, increasing the ammonia flow from the ammonia fuel tank 1 to the ammonia cracking heat exchanger 2, thereby increasing the hydrogen production rate to meet the engine's power demands under heavy load. At the same time, the derivative stage of the PID control monitors exhaust gas temperature changes in real time, quickly suppressing transient shocks caused by exhaust gas temperature fluctuations to the catalyst bed temperature, preventing catalyst activity from being affected by sudden temperature changes. Meanwhile... The ECU synchronously increases the opening of the EGR flow control valve 22, increasing the exhaust gas return flow rate after being cooled by the EGR system 3. This allows the inert gas components in the return exhaust gas to fully enter the mixture, increasing the proportion of inert gas in the mixture to slow down the combustion rate and prevent excessive combustion under high load. The ammonia-hydrogen mixture generated by the ammonia cracking heat exchanger 2 first enters the buffer chamber 21 for temporary storage. After the volume effect of the buffer chamber 21 stabilizes the flow rate of the mixture, it flows into the spiral mixing pipe 20 and mixes fully with the return exhaust gas. The mixed gas is then delivered to the engine intake manifold 5 via the one-way valve 9 for engine combustion. The engine drives the generator, and the electrical energy generated by the generator is converted by the rectifier to charge the battery pack, timely replenishing the electrical energy consumed by the battery pack during the start-up and preheating stages, and ensuring continuous system operation.

[0066] When the ECU receives the exhaust gas temperature data detected by the temperature sensor at the outlet of the second tube of the ammonia cracking heat exchanger and determines that the data is lower than the catalyst activity limit of 350°C, the ECU calculates the temperature deviation through the PID control algorithm module. Based on the deviation value, the ECU controls the battery pack to supply power to the electric heating element 17 through the copper busbar, dynamically adjusting the heating power of the electric heating element 17 to ensure that the heat generated by the electric heating element 17 can effectively compensate for the insufficient exhaust gas residual heat, maintain the catalyst coating temperature stable in the activity range of 350-500°C, ensure the continuous and efficient ammonia cracking reaction, and avoid catalyst deactivation and hydrogen production reduction due to excessively low exhaust gas temperature, thereby affecting engine power output.

[0067] When the ECU obtains the battery charge data from the battery pack's BMS system below a preset threshold, the ECU sends a control signal to maintain the ammonia cracking heat exchanger 2 at the minimum hydrogen production rate. The generator prioritizes charging the battery pack until the battery charge recovers to the preset sufficient threshold. During this process, the EGR flow control valve 22 maintains a fixed minimum opening to ensure that a small amount of recirculated exhaust gas enters the spiral mixing pipe 20, maintaining a stable basic mixing ratio between the ammonia-hydrogen mixture and the exhaust gas. This prevents engine combustion fluctuations due to abnormal mixing ratios, ensuring that the engine can still operate smoothly under low-load charging conditions, while also reserving sufficient electrical energy for subsequent operating condition switching.

[0068] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A hydrogen production device for a high-power commercial ammonia-hydrogen range extender, characterized in that: It includes an ammonia fuel tank (1), an ammonia cracking heat exchanger (2), an EGR system (3), a battery pack, an ECU, an ammonia fuel engine, a generator, a flame arrester, a check valve (9), and a rectifier; The ammonia cracking heat exchanger (2) is used for ammonia cracking reaction and is connected in series with the EGR system (3) through a heat-resistant alloy tube. The outlet of the ammonia fuel tank (1) is connected to the shell-side inlet of the ammonia cracking heat exchanger (2) through a pipe equipped with a proportional solenoid valve (11) and a nozzle (12). Its shell-side outlet is connected to the spiral mixing pipe (20) through a buffer chamber (21) and a flame arrester. The tube-side inlet of the ammonia cracking heat exchanger (2) is connected to the exhaust pipe (4) of the engine through a flange. The tube-side outlet is connected to the inlet of the EGR system (3) used for exhaust gas cooling through a pipe. The outlet end of the EGR system (3) is connected to the spiral mixing pipe (20) through an EGR flow control valve (22). The intake pipe (5) of the engine is connected to the outlet of the spiral mixing pipe (20) via a one-way valve (9); The range extender assembly consists of an engine and a generator, with the generator's current output connected to the battery pack via a rectifier. The ammonia cracking heat exchanger (2) is a shell-and-tube structure independent of the EGR system (3). The shell side of the ammonia cracking heat exchanger (2) is a spiral wound structure with a nozzle (12) at the inlet. Multiple baffles (13) are evenly arranged inside the shell side. The baffles (13) are fixedly connected to the inner wall of the shell side. The inner wall of the shell side and the surface of the baffles (13) are coated with a ruthenium-based catalyst coating to form a catalyst bed. A temperature sensor and a thermocouple are installed inside the shell side. The thermocouple is inserted in the catalyst bed area in the middle of the shell side to detect the catalyst temperature. The shell-side outlet of the ammonia cracking heat exchanger (2) is connected in sequence to a buffer chamber (21), a flame arrester, and a spiral mixing pipe (20). The buffer chamber (21) is used to temporarily store a small amount of ammonia-hydrogen mixture. A pressure sensor is provided on the shell-side outlet pipe. The flame arrester is used to prevent flame backflow caused by high temperature. The inner wall of the spiral mixing pipe (20) is provided with turbulence ridges, and its outlet is connected to the engine intake pipe (5) through a pipe with a one-way valve (9). The catalyst bed is composed of a ruthenium-based catalyst coating and a baffle plate (13); wherein the ruthenium-based catalyst coating uses metallic ruthenium as the active component and porous α-Al2O3 as the carrier, and the baffle plate (13) has a fan-shaped structure with a central angle of 60° and is arranged at an inclination of 30° relative to the shell-side axis. The catalyst coating on its surface is connected to the catalyst coating on the inner wall of the shell-side to form a continuous catalytic reaction channel. The exhaust gas from the engine enters the tube side of the ammonia cracking heat exchanger (2) through the exhaust pipe for initial heat release and exchange. The tube side outlet of the ammonia cracking heat exchanger (2) is connected to the EGR system (3). The exhaust gas is cooled a second time by the EGR system (3), and then connected to the spiral mixing pipe (20) through the EGR flow control valve (22).

2. The hydrogen production device for a high-power commercial ammonia-hydrogen range extender according to claim 1, characterized in that: The battery pack adopts a high-capacity modular structure and is installed on the vehicle chassis. The outer wall of the shell is wrapped with an electric heating element (17). The battery pack supplies power to the electric heating element (17) of the ammonia cracking heat exchanger (2). The ECU is connected via CAN bus to the proportional solenoid valve (11), temperature sensor, thermocouple, pressure sensor, EGR flow control valve (22), battery pack BMS system, engine speed sensor and generator voltage regulator.

3. The hydrogen production device for a high-power commercial ammonia-hydrogen range extender according to claim 2, characterized in that: The ECU has a built-in PID control algorithm module, which is used to dynamically adjust the opening degree of the proportional solenoid valve (11), the heating power of the electric heating element (17) and the opening degree of the EGR flow control valve (22) according to the catalyst bed temperature detected by the thermocouple, the mixture pressure detected by the pressure sensor and the engine load signal.

4. The hydrogen production device for a high-power commercial ammonia-hydrogen range extender according to claim 1, characterized in that: The ammonia cracking heat exchanger (2) and the EGR system (3) form a functionally independent series structure; the ammonia cracking heat exchanger (2) is dedicated to using the waste heat of engine exhaust gas to crack hydrogen from ammonia. The flow path of the ammonia-hydrogen mixture is as follows: shell side of ammonia cracking heat exchanger (2), buffer chamber (21), flame arrester, spiral mixing pipe (20), and intake pipe (5). The EGR system (3) cools the return exhaust gas through the tube side of the ammonia cracking heat exchanger (2). The flow path of the return exhaust gas is as follows: engine exhaust pipe (4), ammonia cracking heat exchanger (2) tube side, EGR system (3), EGR flow control valve (22), spiral mixing pipe (20).

5. The hydrogen production device for a high-power commercial ammonia-hydrogen range extender according to claim 3, characterized in that: The spiral mixing pipe (20) is used to enhance the mixing effect of hydrogen produced by ammonia cracking, uncracked ammonia and the return exhaust gas cooled by the EGR system (3) to meet the high power requirements of ammonia fuel engine; the EGR flow control valve (22) can dynamically adjust the exhaust gas return flow according to the engine load signal, thereby optimizing the volume ratio of the mixed gas.

6. A control method for a hydrogen production device using a high-power commercial ammonia-hydrogen range extender, applied to a hydrogen production device using a high-power commercial ammonia-hydrogen range extender as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Based on the ECU, the battery pack's power data and the engine's water temperature data are obtained. When the power data and water temperature data meet the preset indicators, the engine is driven to start. At the same time, the electric heating element (17) of the ammonia cracking heat exchanger (2) is controlled to start working to preheat the ruthenium-based catalyst coating and increase the temperature. Based on the thermocouple, the real-time temperature data of the ruthenium-based catalyst coating is obtained. When the real-time temperature data is greater than or equal to the preset active temperature of the catalyst, the preset active temperature is expressed as 350℃. Based on the ECU control, the proportional solenoid valve (11) is opened, and ammonia enters the shell side of the ammonia cracking heat exchanger (2) through the nozzle (12) to exchange heat with the tail gas in the tube side, and is cracked to generate hydrogen and nitrogen under the action of the ruthenium-based catalyst coating. Based on the vehicle load signal, the ECU adjusts the opening of the proportional solenoid valve (11) and the EGR flow control valve (22) through the PID algorithm; based on the temperature data of the ammonia cracking heat exchanger (2) obtained by the temperature sensor, the ECU adjusts the heating power of the electric heating element (17) based on the real-time temperature data, and adjusts the power of the ammonia cracking heat exchanger (2) based on the battery pack power data.

7. The control method for a hydrogen production device using a high-power commercial ammonia-hydrogen range extender according to claim 6, characterized in that: When the vehicle load signal indicates that the vehicle is operating normally, the ECU uses the catalyst bed temperature as the first feedback parameter to adjust the heating power of the electric heating element (17) as the proportional term of the PID control and adjusts the opening of the proportional solenoid valve (11) as the integral term of the PID control. When the temperature fluctuation exceeds ±5℃, the PID derivative term is triggered for correction. Based on the pressure data of the ammonia-hydrogen mixture obtained by the pressure sensor as the second feedback parameter, the opening of the EGR flow control valve (22) is adjusted. When the pressure deviation exceeds ±0.02MPa, the opening of the proportional solenoid valve (11) is dynamically corrected. When the vehicle load signal indicates heavy load or high speed, the ECU calculates the required hydrogen supply and total volume of the mixture based on the engine load signal. It increases the opening of the proportional solenoid valve (11) through the PID algorithm to increase the ammonia flow rate and the opening of the EGR flow control valve (22) to increase the exhaust gas return flow rate. It also increases the proportion of inert gas in the mixture. The ammonia-hydrogen mixture enters the spiral mixing pipe (20) through the buffer chamber (21) and is fully mixed with the return exhaust gas cooled by the EGR system (3) before entering the engine for combustion and power generation. At the same time, it drives the generator to charge the battery pack. When the temperature sensor detects that the exhaust gas temperature is lower than the preset active temperature, the ECU controls the battery pack to supply power to the electric heating element (17) through the PID algorithm to maintain the temperature of the ruthenium-based catalyst coating. When the battery pack's charge data is lower than the preset threshold, the ammonia cracking heat exchanger (2) maintains the minimum hydrogen production rate, the engine prioritizes driving the generator to charge the battery pack, and the EGR flow control valve (22) maintains the minimum opening to keep the basic mixing ratio stable.

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