Vehicle-mounted internal-external self-heating ammonia conversion hydrogen production system and control method thereof

Abstract

The application is suitable for the field of ammonia conversion hydrogen production technology, and provides a vehicle-mounted internal and external self-heating ammonia conversion hydrogen production system and a control method thereof.The system comprises an ammonia decomposition hydrogen production device, an ammonia supply unit, a self-heating device and an electric control unit.The system can select different working modes.In the cold start process, hydrogen filtered by a hydrogen purification device and stored in a hydrogen temporary storage tank is used as the main fuel and is introduced into the combustion chamber of the self-heating device, and the heat generated by combustion is transmitted to the reaction inner cavity to provide heat for the ammonia decomposition reaction.In the idling process, the mixed gas generated by the ammonia decomposition reaction is introduced into the hydrogen purification device from the gas temporary storage tank, and then passes through the hydrogen storage tank and is finally introduced into the combustion chamber of the self-heating device in real time, and cooperates with the tail gas waste heat to provide heat for the ammonia decomposition hydrogen production reaction in real time.The energy consumption of the ammonia fuel vehicle operation is effectively reduced, and the problem of insufficient fuel supply of the ammonia fuel vehicle during cold start is alleviated.

Description

Technical Field

[0001] This invention belongs to the field of ammonia conversion hydrogen production technology, and particularly relates to an on-board, internal and external self-heating ammonia conversion hydrogen production system and its control method. Background Technology

[0002] Zero-carbon economy is the trend of future economic development, and ammonia has become a popular new fuel due to its advantages in manufacturing cost, transportation safety, and energy storage. Globally, ammonia has a massive annual production capacity of 100 million tons. Ammonia fuel cell vehicles will become another zero-carbon emission fuel vehicle after hydrogen fuel cell vehicles. Ammonia has a distinctive odor, allowing for timely detection of leaks during driving. Compared to commonly available fuels, ammonia has a lower calorific value and combustion speed, thus requiring fuels with higher calorific value as igniters. The hydrogen storage capacity per unit volume of ammonia is 1.5 times that of hydrogen gas. Considering the risks associated with hydrogen storage and transportation, producing igniter hydrogen through the decomposition of some ammonia is the development direction for ammonia fuel cell vehicles.

[0003] When ammonia-fueled vehicles are in operation, their internal ammonia cracking hydrogen generator continuously converts some ammonia into hydrogen. This cracked hydrogen assists engine combustion, avoiding the safety risks associated with storing large amounts of hydrogen on-board and compensating for the poor flammability of ammonia fuel. Ammonia decomposition is a reversible endothermic reaction. To ensure complete ammonia decomposition, the reaction needs to be maintained within a reasonable temperature and pressure range; otherwise, the probability of reverse synthesis will increase, leading to reduced ammonia decomposition efficiency and affecting the operation of ammonia-fueled vehicles. Most commercially available and research-based crackers compensate for temperature using electric heating devices. While this facilitates control and simplifies the device, the instantaneous performance and energy utilization efficiency of electric heating are inferior to combustion heating in automotive applications.

[0004] Meanwhile, during vehicle operation, the transition time between different operating conditions is short, requiring the ammonia cracker products to have good adaptability to the operating conditions. However, the electric heater has a slightly slower temperature response and is not easy to start at low temperatures. Due to space constraints and pressure on the unit, there are significant temperature differences in different areas of the reactor within the temperature field atmosphere created by the electric heater, affecting the proportion of products generated by the reactor. Summary of the Invention

[0005] The purpose of this invention is to provide an on-board, internal and external self-heating ammonia-to-hydrogen conversion system and its control method, aiming to solve the problems mentioned in the background art.

[0006] This invention is implemented as follows: an on-board, internally and externally self-heating ammonia-to-hydrogen conversion system includes:

[0007] An ammonia decomposition hydrogen production device is provided. The inlet of the ammonia decomposition hydrogen production device is connected to an ammonia supply unit, which supplies ammonia gas to the device. An ammonia control valve and an ammonia flow sensor are also installed between the device and the supply unit. The outlet of the ammonia decomposition hydrogen production device is connected to a gas storage tank. A mixed gas flow sensor is also installed between the outlet and the storage tank. An ammonia concentration sensor and a first hydrogen concentration sensor are installed in the storage tank. The storage tank is connected to a hydrogen purification device, which is also connected to both an engine and the storage tank. The purification device is connected to the storage tank via a negative pressure compressor. A hydrogen storage tank inlet control valve is installed between the compressor and the storage tank. A second hydrogen concentration sensor and a storage tank pressure sensor are installed on the storage tank. The storage tank is also connected to the engine, and a hydrogen storage tank outlet control valve is installed between the tank and the engine.

[0008] The self-heating device is encased in the ammonia decomposition hydrogen production unit. The self-heating device has multiple combustion chambers for segmented heating of different areas of the ammonia decomposition hydrogen production unit. It also includes a second temperature sensor and a chamber pressure sensor for monitoring the combustion chambers. Each combustion chamber has a hydrogen inlet, an air inlet, and a combustion exhaust outlet. Each combustion exhaust outlet is connected to an exhaust gas treatment device and is equipped with an exhaust control valve. The hydrogen inlet is equipped with a hydrogen control valve and a hydrogen flow sensor, and the air inlet is equipped with an air control valve and an air flow sensor.

[0009] An electrical control unit, which is connected to each electrical component, is used to control the start and stop of each component.

[0010] A further technical solution is provided, wherein the ammonia decomposition hydrogen production device includes a ring-shaped device body, a through-type tail gas channel is provided in the middle of the ring-shaped device body, a ring-shaped air inlet cover is provided at one end of the ring-shaped device body, and symmetrically distributed air inlet pipes are provided on the ring-shaped air inlet cover, and a ring-shaped exhaust cover is provided at the other end of the ring-shaped device body, and symmetrically distributed exhaust pipes are provided on the ring-shaped exhaust cover. The interior of the ring-shaped device body is provided with a reaction chamber for the ammonia decomposition hydrogen production reaction, and a first temperature sensor for monitoring the reaction chamber is also provided in the ring-shaped device body.

[0011] A further technical solution includes a self-heating device comprising an annular hollow combustion chamber for supplying a hydrogen mixture for oxidation. The self-heating device is equipped with a hydrogen inlet, an air inlet, and a combustion exhaust outlet communicating with the combustion chamber. The interior of the combustion chamber is divided into different areas by a partition baffle, which is fixed to the inner side of the combustion chamber by welding. Both the hydrogen inlet and the air inlet are perpendicular to the outer shell of the self-heating device and are at a certain angle to each other. An ignition switch is located on the bisector of this angle. The number and position of the ignition switch and the air inlet pipes can be adjusted according to different usage conditions, and the combustion exhaust outlet is located on the opposite side of the ignition switch.

[0012] In a further technical solution, the self-heating device is also covered with an annular heat-insulating shell.

[0013] In a further technical solution, the ammonia supply unit includes a liquid ammonia tank, which is connected to a vaporization device, and the vaporization device is connected to an air inlet pipe through a pipeline, thereby supplying ammonia gas to the air inlet pipe.

[0014] In a further technical solution, both the annular air intake cover and the annular exhaust cover are connected to the main body of the annular device by bolts, and the self-heating device is also installed on the main body of the annular device by bolts.

[0015] Another objective of this invention is to provide a control method for an on-board self-heating ammonia-to-hydrogen conversion system, based on the aforementioned on-board self-heating ammonia-to-hydrogen conversion system, comprising the following steps:

[0016] Step 1: Obtain the real-time temperature of the reaction chamber using the first temperature sensor. The real-time ammonia content in the gas storage tank is obtained through an ammonia concentration sensor. The real-time hydrogen content in the gas storage tank is obtained through the first hydrogen concentration sensor. and the obtained , and Transmitted to the electronic control unit;

[0017] Step 2, , as well as Each value is compared with a preset value:

[0018] The electronic control unit will obtain The optimal reaction temperature is preset within the reaction chamber. The determination was made, and the ammonia content of the obtained mixed gas was simultaneously measured. and hydrogen content Each concentration is compared with a preset concentration range;

[0019] Step 3: The electronic control unit determines the device's operating status based on the judgment result, and simultaneously determines whether to activate the self-heating device:

[0020] If the electronic control unit determines <Minimum operating temperature If the device is in a cold start condition, it is determined that the concentration of ammonia and hydrogen is within the range of cold start conditions.

[0021] if >Minimum operating temperature ,and <Optimal reaction temperature If the device is in an idling state, it is determined that the condition is met by verifying the ammonia and hydrogen content.

[0022] If the electronic control unit determines <Optimal reaction temperature If so, the self-heating device will be activated;

[0023] If the electronic control unit determines >Optimal reaction temperature If so, the self-heating device will not be activated;

[0024] Step 4: Obtain the real-time temperature of the combustion chamber using the second temperature sensor. The real-time intake volume of hydrogen is obtained through a hydrogen flow sensor. The real-time air intake volume is obtained through an air flow sensor. The real-time pressure of the combustion chamber is obtained through a chamber pressure sensor. The real-time hydrogen concentration in the hydrogen storage tank is obtained through a second hydrogen concentration sensor. and the rate of decrease in hydrogen concentration over time The real-time pressure of the hydrogen storage tank is obtained through a hydrogen storage tank pressure sensor. And transmit each data to the electronic control unit;

[0025] Step 5, , , , , , as well as Each value is compared with a preset value:

[0026] The electronic control unit adjusts the judgment values ​​of various parameters based on the working state determined in step 3. First, the electronic control unit obtains... With optimal heating temperature The determination is made; secondly, the electronic control unit makes a judgment based on... and The difference in air volume determines the required combustion intensity, and then sets different preset values ​​for intake air volume; subsequently, the electronic control unit obtains... and Preset flow rates corresponding to different combustion intensities and Make a judgment;

[0027] During this process, the electronic control unit will obtain the data in real time. With the maximum permissible pressure value of the combustion chamber The determination is made as follows: Under cold start conditions, the hydrogen required for combustion is supplied only by the hydrogen temporarily stored in the hydrogen storage tank. However, under idling conditions, since the ammonia decomposition hydrogen production unit can already produce a mixture, the electronic control unit will determine the required hydrogen supply to ensure the hydrogen supply during combustion. With the projected hydrogen consumption rate The determination will be made; at the same time, the electronic control unit will also receive... and The hydrogen concentration allowed by the preset hydrogen storage tank is respectively... and maximum warning pressure value Make a judgment;

[0028] Step 6: The electrical control unit determines the opening degree and opening / closing time of each servo valve based on its current working status and judgment results, and simultaneously determines whether to start the negative pressure unit.

[0029] If the electronic control unit determines <Optimal heating temperature If so, increase the opening of the hydrogen control valve and the air control valve;

[0030] If the electronic control unit determines >Optimal heating temperature If so, the opening degree of the hydrogen control valve and the air control valve is reduced, and if the electronic control unit determines at this time... <Maximum permissible pressure value of combustion chamber Then, while ensuring pressure safety, appropriately reduce the opening of the exhaust control valve and increase the residence time t of the high-temperature gas until... <Optimal heating temperature Then, immediately increase the opening of the exhaust control valve to discharge the low-temperature exhaust gas, and repeat the above judgment process;

[0031] The electronic control unit synchronously matches different intake standards based on the combustion intensity determined in step 5:

[0032] If the electronic control unit determines Optimal hydrogen intake If so, increase the opening of the hydrogen control valve;

[0033] If the electronic control unit determines >Optimal hydrogen intake Reduce the opening of the hydrogen control valve, and at the same time, adjust the opening of the air control valve according to the combustion intensity to provide sufficient air.

[0034] If the electronic control unit determines >Maximum permissible pressure value of combustion chamber Immediately increase the opening of the exhaust control valve;

[0035] If the electronic control unit determines >Expected consumption rate If necessary, increase the opening of the hydrogen storage tank inlet control valve and start the negative pressure machine or increase the power of the negative pressure machine;

[0036] If the electronic control unit determines <Expected consumption rate If necessary, reduce the opening of the hydrogen storage tank inlet control valve and reduce or shut down the negative pressure compressor.

[0037] If the electronic control unit determines >Preset maximum hydrogen concentration in hydrogen storage tank Immediately reduce the opening of the hydrogen storage tank intake control valve while increasing the engine intake air volume.

[0038] Step 7, Overpressure Warning and Control:

[0039] If the electronic control unit determines >Maximum warning pressure value Immediately close the hydrogen storage tank intake control valve to increase the engine's intake air volume, and simultaneously issue an alarm to prompt an increase in engine input power.

[0040] The present invention provides an on-board, internal and external self-heating ammonia-to-hydrogen conversion system and its control method, the beneficial effects of which are as follows:

[0041] (1) Considering the reaction characteristics of the automobile pyrolysis unit itself, the use of segmented combustion control can reasonably compensate for the temperature required in different areas, improve the matching degree between reaction products and environmental conditions, reduce the probability of retrosynthesis reaction in the pyrolysis unit, and enhance the working performance of ammonia fuel automobile engines.

[0042] (2) The device does not require any other external energy source during operation. It only utilizes the residual energy of the tail gas and the thermal atmosphere provided by the oxidation reaction of the hydrogen mixture. It has a lower dependence on the external environment and higher energy utilization efficiency.

[0043] (3) The zoned combustion control and combustion intensity control strategies better match the ammonia reaction concentration in different sections of the ammonia decomposition unit, matching different combustion intensities for different ammonia content sections, thereby enhancing ammonia conversion efficiency and energy utilization efficiency.

[0044] (4) The ignition system of the self-heating device can be arranged freely according to the actual situation. The ignition system can be arranged on one side so that the waste in the combustion chamber can be discharged. The ignition system can also be arranged symmetrically with ignition on both sides so that the reaction chamber can be heated evenly. In addition, if the size of the device is limited, the size of the combustion chamber needs to be reduced. In order to prevent the size from being too small and limiting the flame propagation range in the combustion chamber, a hydrogen-promoting combustion catalyst can be selectively coated on the inner wall of the combustion chamber to enhance the combustion effect. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of an on-board, internally and externally self-heating ammonia-to-hydrogen conversion system provided in an embodiment of the present invention;

[0046] Figure 2 A schematic diagram of the structure of an ammonia decomposition hydrogen production device in an on-board self-heating ammonia conversion hydrogen production system provided in an embodiment of the present invention;

[0047] Figure 3 A cross-sectional view of an ammonia decomposition hydrogen production device in an on-board self-heating ammonia conversion hydrogen production system provided in an embodiment of the present invention;

[0048] Figure 4 A cross-sectional view from another perspective of an ammonia decomposition hydrogen production device in an on-board self-heating ammonia conversion hydrogen production system provided in an embodiment of the present invention.

[0049] Figure 5 A partial cross-sectional view of an ammonia decomposition hydrogen production device in an on-board self-heating ammonia conversion hydrogen production system provided in an embodiment of the present invention;

[0050] Figure 6 A flowchart illustrating a control method for an on-board, internally and externally self-heating ammonia-to-hydrogen conversion system provided in an embodiment of the present invention.

[0051] In the attached diagram: 1. Ammonia supply unit; 2. Ammonia control valve; 3. Ammonia flow sensor; 4. Exhaust gas passage; 5. Electronic control unit; 6. First temperature sensor; 7. Second temperature sensor; 8. Ignition switch; 9. Hydrogen control valve; 10. Chamber pressure sensor; 11. Air control valve; 12. Hydrogen inlet; 13. Air inlet; 14. Ring device body; 15. Exhaust pipe; 16. Air flow sensor; 17. Hydrogen flow sensor; 18. Exhaust control valve; 19. Combustion exhaust outlet; 20. Reaction chamber; 21. Self-heating device. 22. Separator baffle; 23. Ammonia concentration sensor; 24. First hydrogen concentration sensor; 25. Gas storage tank; 26. Mixed gas flow sensor; 27. Hydrogen purification device; 28. Negative pressure unit; 29. ​​Second hydrogen concentration sensor; 30. Hydrogen storage tank pressure sensor; 31. Hydrogen storage tank inlet control valve; 32. Hydrogen storage tank exhaust control valve; 33. Engine; 34. Annular insulation shell; 35. Exhaust gas treatment device; 36. Combustion chamber; 37. Annular air intake cover; 38. Air intake pipe; 39. Annular exhaust cover; 40. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0053] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0054] like Figure 1 As shown, an on-board self-heating ammonia-to-hydrogen conversion system according to an embodiment of the present invention includes:

[0055] An ammonia decomposition hydrogen production device is provided. The inlet of the device is connected to an ammonia supply unit 1, which supplies ammonia gas to the device. An ammonia control valve 2 and an ammonia flow sensor 3 are also installed between the device and the supply unit 1. The outlet of the device is connected to a gas storage tank 25. A mixed gas flow sensor 26 is installed between the outlet and the storage tank 25. The storage tank 25 also contains an ammonia concentration sensor 23 and a first hydrogen concentration sensor 24. Tank 25 is connected to a hydrogen purification device 27, which is also connected to the engine 34 and the hydrogen storage tank 31. The hydrogen purification device 27 is connected to the hydrogen storage tank 31 via a negative pressure machine 28. A hydrogen storage tank inlet control valve 32 is also provided between the negative pressure machine 28 and the hydrogen storage tank 31. A second hydrogen concentration sensor 29 and a hydrogen storage tank pressure sensor 30 are provided on the hydrogen storage tank 31. The hydrogen storage tank 31 is also connected to the engine 34, and a hydrogen storage tank exhaust control valve 33 is provided between the hydrogen storage tank 31 and the engine 34.

[0056] A self-heating device 21 is mounted on an ammonia decomposition hydrogen production device. The self-heating device 21 is equipped with multiple combustion chambers 37 for segmented heating of different areas of the ammonia decomposition hydrogen production device. The self-heating device 21 is also equipped with a second temperature sensor 7 and a chamber pressure sensor 10 for monitoring the combustion chambers 37. Each combustion chamber 37 of the self-heating device 21 is equipped with a hydrogen inlet 12, an air inlet 13, and a combustion exhaust gas outlet 19. Each combustion exhaust gas outlet 19 is connected to an exhaust gas treatment device 36, and each combustion exhaust gas outlet 19 is equipped with an exhaust control valve 18. The hydrogen inlet 12 is equipped with a hydrogen control valve 9 and a hydrogen flow sensor 17, and the air inlet 13 is equipped with an air control valve 11 and an air flow sensor 16.

[0057] The electronic control unit 5 is connected to each electrical component and is used to control the start and stop of each component.

[0058] like Figure 1-5As shown, in a preferred embodiment of the present invention, the ammonia decomposition hydrogen production device includes an annular device body 14. A through-type tail gas channel 4 is provided in the middle of the annular device body 14. An annular inlet cover 38 is provided at one end of the annular device body 14, and symmetrically distributed inlet pipes 39 are provided on the annular inlet cover 38. An annular exhaust cover 40 is provided at the other end of the annular device body 14, and symmetrically distributed exhaust pipes 15 are provided on the annular exhaust cover 40. The interior of the annular device body 14 is provided with a reaction chamber 20 for the ammonia decomposition hydrogen production reaction, and a first temperature sensor 6 for monitoring the reaction chamber 20 is also provided in the annular device body 14.

[0059] The self-heating device 21 includes an annular hollow combustion chamber 37 for supplying hydrogen mixture for oxidation reaction. The self-heating device 21 is equipped with a hydrogen inlet 12, an air inlet 13, and a combustion exhaust outlet 19 communicating with the combustion chamber 37. The combustion chamber 37 is divided into different areas by a partition baffle 22, which is fixed to the inside of the combustion chamber 37 by welding. The hydrogen inlet 12 and the air inlet 13 are both perpendicular to the outer shell of the self-heating device and are set at a certain angle to each other. An ignition switch 8 is located on the bisector of their angle. The number and position of the ignition switch 8 and the air inlet pipes can be adjusted according to different usage conditions. The combustion exhaust outlet 19 is located on the opposite side of the ignition switch 8.

[0060] The self-heating device 21 is also covered by an annular heat-insulating shell 35.

[0061] In this embodiment of the invention, ammonia gas is discharged from the ammonia supply unit 1 and enters the reaction chamber 20 through the intake pipe 39. In the reaction chamber 20, it is heated by the residual energy of the exhaust gas and the hot atmosphere provided by the self-heating device, and undergoes an ammonia decomposition hydrogen production reaction with the catalyst coated in the chamber, generating a mixture of ammonia, nitrogen, and hydrogen. This mixture flows into the gas storage tank 25 through the exhaust pipe 15, and then into the hydrogen purification device 27. The purified hydrogen has two flow directions: most of the hydrogen flows directly into the engine 34 to provide fuel; a small portion flows into the hydrogen storage tank 31, and the hydrogen flow rate into the combustion chamber is controlled by the hydrogen control valve 9 at the hydrogen intake inlet 12 on the combustion chamber 37. When hydrogen enters the combustion chamber 37, it mixes with the air entering the combustion chamber 37 through the air control valve 11. The ignition switch 8 then ignites the mixture according to different operating conditions, providing temperature compensation for the ammonia decomposition reaction. The resulting mixed exhaust gas is discharged through the combustion exhaust outlet 19 to the exhaust gas treatment device 36 for purification. The temperature and operation of the self-heating device 21 can be controlled by adjusting the intake flow rate of the hydrogen control valve 9 and the air control valve 11, thereby obtaining the required ammonia-hydrogen mixture and producing the corresponding ammonia-hydrogen mixture according to different vehicle operating conditions.

[0062] In a preferred embodiment of the present invention, the main body 14 of the annular device and the inner wall of the combustion chamber 37 are both composed of corrosion-resistant alloys with good thermal conductivity.

[0063] In a preferred embodiment of the present invention, the annular air intake cover 38 and the annular exhaust cover 40 are both connected to the annular device body 14 by bolts, and the self-heating device 21 is also installed on the annular device body 14 by bolts.

[0064] In this embodiment of the invention, in order to ensure sealing, sealing gaskets are provided at the positions used for bolt fixing. In particular, the sealing gaskets used to fix the self-heating device 21 have good high temperature resistance and corrosion resistance.

[0065] In a preferred embodiment of the present invention, the ammonia supply unit 1 includes a liquid ammonia tank, the liquid ammonia tank is connected to a vaporization device, and the vaporization device is connected to the air inlet pipe 39 through a pipeline, thereby supplying ammonia gas to the air inlet pipe 39.

[0066] like Figure 6 The diagram illustrates a control method for an on-board self-heating ammonia-to-hydrogen conversion system according to an embodiment of the present invention. Based on the aforementioned on-board self-heating ammonia-to-hydrogen conversion system, the method includes the following steps:

[0067] Step 1: Obtain the real-time temperature of the reaction chamber 20, and simultaneously obtain the ammonia and hydrogen content in the gas storage tank:

[0068] The real-time temperature of the reaction chamber 20 obtained by the first temperature sensor 6 The real-time ammonia content in the gas storage tank is obtained through ammonia concentration sensor 23. The real-time hydrogen content in the gas storage tank is obtained through the first hydrogen concentration sensor 24. and the obtained , and The data is transmitted to the electronic control unit 5.

[0069] Step 2: Monitor the real-time temperature of the reaction chamber 20. ammonia content in the mixed gas Hydrogen content of the gas mixture Compare with preset values:

[0070] The electronic control unit 5 will obtain the real-time temperature of the reaction chamber 20. With the reaction chamber 20 preset optimal reaction temperature The determination was made, and the ammonia content of the obtained mixed gas was simultaneously measured. Hydrogen content Each concentration is compared with a preset concentration range.

[0071] Step 3: The electronic control unit 5 determines the working status of the device based on the judgment result, and at the same time determines whether to start the self-heating device 21.

[0072] If the electronic control unit 5 determines <Minimum operating temperature If so, the device is determined to be in cold start condition, and this is verified by checking whether the ammonia and hydrogen concentrations meet the concentration range for cold start conditions. >Minimum operating temperature ,and <Optimal reaction temperature If the device is in an idling state, it is determined that the condition is being verified based on the ammonia and hydrogen content.

[0073] If the electronic control unit 5 determines <Optimal reaction temperature If so, the self-heating device will be activated.

[0074] If the electronic control unit 5 determines >Optimal reaction temperature If not, the self-heating device will not be activated.

[0075] Step 4: Obtain the real-time temperature of combustion chamber 37 using the second temperature sensor 7. The real-time intake volume of hydrogen is obtained through hydrogen flow sensor 17. The real-time air intake volume is obtained through the air flow sensor 16. The real-time pressure of the combustion chamber 37 is obtained through the chamber pressure sensor 10. The real-time hydrogen concentration in the hydrogen storage tank is obtained through the second hydrogen concentration sensor 29. and the rate of decrease in hydrogen concentration over time The real-time pressure of the hydrogen storage tank is obtained through the hydrogen storage tank pressure sensor 30. The data is then transmitted to the electronic control unit 5.

[0076] Step 5, , , , , , as well as Each value is compared with a preset value:

[0077] The electronic control unit 5 adjusts the judgment values ​​of each parameter based on the working state determined in step 3. First, the electronic control unit 5 obtains... With optimal heating temperature Make a judgment; then the electronic control unit 5 makes a judgment based on... and The difference in air volume determines the required combustion intensity, and then sets different preset values ​​for intake air volume; subsequently, the electronic control unit 5 obtains the required value. and Preset flow rates corresponding to different combustion intensities and The determination is made; during this process, the electronic control unit 5 will obtain the data in real time. With the maximum permissible pressure value of the combustion chamber The determination is made; specifically, under cold start conditions, the hydrogen required for combustion is only supplied by the hydrogen temporarily stored in the hydrogen storage tank 31, while under idling conditions, since the ammonia decomposition hydrogen production unit can already produce a mixed gas, in order to ensure the hydrogen supply capacity during combustion, the electronic control unit 5 obtains the real-time hydrogen concentration decrease rate of the hydrogen storage tank. With the projected hydrogen consumption rate The determination is made; at the same time, the electronic control unit 5 will also obtain the real-time hydrogen concentration in the hydrogen temporary storage tank 31. Real-time pressure of hydrogen storage tank 31 The hydrogen concentration is respectively compared with the maximum allowable hydrogen concentration of the preset hydrogen storage tank 31. and maximum warning pressure value Make a judgment.

[0078] Step 6: The electrical control unit 5 determines the opening degree and opening / closing time of each servo valve based on its current working status and judgment results, and simultaneously determines whether to start the negative pressure unit 28.

[0079] If the electronic control unit 5 determines <Optimal heating temperature If so, increase the opening of hydrogen control valve 9 and air control valve 11;

[0080] If the electronic control unit 5 determines >Optimal heating temperature If so, the opening degree of hydrogen control valve 9 and air control valve 11 is reduced, and if the electronic control unit 5 determines at this time... <Maximum permissible pressure value of combustion chamber Then, while ensuring pressure safety, the opening of the exhaust control valve 18 can be appropriately reduced to increase the residence time t of the high-temperature gas until... <Optimal heating temperature Then, immediately increase the opening of the exhaust control valve 18 to discharge the low-temperature exhaust gas, and repeat the above judgment process.

[0081] Electronic control unit 5 synchronously matches different intake standards based on the combustion intensity determined in step 5:

[0082] If the electronic control unit 5 determines Optimal hydrogen intake If so, increase the opening of hydrogen control valve 9;

[0083] If the electronic control unit 5 determines >Optimal hydrogen intake Reduce the opening of hydrogen control valve 9, and at the same time, control the opening of air control valve 11 to supplement sufficient air according to the combustion intensity.

[0084] If the electronic control unit 5 determines >Maximum permissible pressure value of combustion chamber Immediately increase the opening of the exhaust control valve 18;

[0085] If the electronic control unit 5 determines >Expected consumption rate If the opening degree of the hydrogen storage tank inlet control valve 32 is increased, the negative pressure machine 28 is started or the power of the negative pressure machine 28 is increased;

[0086] If the electronic control unit 5 determines <Expected consumption rate If the opening of the hydrogen storage tank inlet control valve 32 is reduced, the power of the negative pressure machine 28 is reduced or the negative pressure machine 28 is shut down.

[0087] If the electronic control unit 5 determines >Preset maximum hydrogen concentration in hydrogen storage tank Immediately reduce the opening of the hydrogen storage tank intake control valve 32, while simultaneously increasing the intake volume of the engine 34.

[0088] Step 7, Overpressure Warning and Control:

[0089] If the electronic control unit 5 determines >Maximum warning pressure value Immediately close the valve of the hydrogen storage tank intake control valve 32 to increase the engine's intake air volume, and at the same time issue an alarm to prompt an increase in engine input power.

[0090] In this embodiment of the invention, when the car engine is not running or the exhaust gas temperature is low, the device acts as a heat source for the ammonia decomposition and hydrogen production device, providing the required temperature for the reaction. Different threshold values ​​are set for each control component depending on the operating conditions of the device, thus enabling different controls. After the device starts, data collected by the first temperature sensor 6 located in the reaction chamber 20 is fed back to the electronic control unit 5 to determine the device's operating status. Based on the temperature difference, the opening of the servo valve at the air inlet of the self-heating device 21 is controlled to adjust the supply of hydrogen and air. Finally, based on the data from the chamber pressure sensor 10 in the combustion chamber 37, the servo valve at the exhaust end is controlled to adjust the pressure within the combustion chamber 37.

[0091] The closing time t of the servo valve at the exhaust end is determined by the real-time temperature of the second temperature sensor 7 inside the combustion chamber. The decision is also related to the magnitude of internal pressure.

[0092] To ensure the overall temperature uniformity of the ammonia decomposition hydrogen production unit, the self-heating device 21 adopts a zoned design, with different optimal heating temperatures set for the three zones. This temperature value is based on the real-time temperature of the inner liner. With the preset optimal temperature The difference is determined.

[0093] The operating status of the device is mainly determined by the real-time temperature of the inner liner. When 0 < < When the device is in startup condition, it is determined that the device is in startup condition; when < < If the device is in an idling state, it is determined that the device is in an idling state.

[0094] The device requires a higher combustion intensity during cold start. During idling, the exhaust gas already has a certain temperature, so only a relatively lower combustion intensity is needed. Simultaneously, as the reaction occurs, the temperature of the reactant gases gradually decreases, with different temperatures in different sections. To ensure the uniformity of the overall reaction temperature, different combustion intensities are applied to different sections to achieve temperature uniformity.

[0095] To improve the speed of the gas mixture separation process, the hydrogen extracted by the hydrogen purification device 27 contains a small amount of ammonia and nitrogen. Therefore, a combustion exhaust gas treatment device is installed at the end of the combustion device to ensure the cleanliness of the exhaust gas.

[0096] After the electronic control unit 5 determines the status of the device, it adjusts the preset values ​​of different parameters to make the device have different combustion intensities to meet the needs of different working conditions.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vehicle-mounted, internally and externally self-heating ammonia-to-hydrogen conversion system, characterized in that, include: An ammonia decomposition hydrogen production device is provided. The inlet of the ammonia decomposition hydrogen production device is connected to an ammonia supply unit. An ammonia control valve and an ammonia flow sensor are installed between the ammonia decomposition hydrogen production device and the ammonia supply unit. The exhaust end of the ammonia decomposition hydrogen production device is connected to a gas storage tank. A mixed gas flow sensor is installed between the exhaust end of the ammonia decomposition hydrogen production device and the gas storage tank. The gas storage tank also contains an ammonia concentration sensor and a first hydrogen concentration sensor. The gas storage tank is connected to a hydrogen purification device, which is simultaneously connected to an engine and the hydrogen storage tank. The hydrogen purification device is connected to the hydrogen storage tank via a negative pressure compressor. A hydrogen storage tank inlet control valve is installed between the negative pressure compressor and the hydrogen storage tank. A second hydrogen concentration sensor and a hydrogen storage tank pressure sensor are installed on the hydrogen storage tank. The hydrogen storage tank is also connected to the engine, and a hydrogen storage tank exhaust control valve is installed between the hydrogen storage tank and the engine. The self-heating device is encased in the ammonia decomposition hydrogen production unit. The self-heating device has multiple combustion chambers for segmented heating of different areas of the ammonia decomposition hydrogen production unit. It also includes a second temperature sensor and a chamber pressure sensor for monitoring the combustion chambers. Each combustion chamber has a hydrogen inlet, an air inlet, and a combustion exhaust outlet. Each combustion exhaust outlet is connected to an exhaust gas treatment device and is equipped with an exhaust control valve. The hydrogen inlet is equipped with a hydrogen control valve and a hydrogen flow sensor, and the air inlet is equipped with an air control valve and an air flow sensor. An electrical control unit, which is connected to each electrical component, is used to control the start and stop of each component.

2. The on-board self-heating ammonia-to-hydrogen conversion system according to claim 1, characterized in that, The ammonia decomposition hydrogen production device includes a ring-shaped main body with a through-type tail gas channel in the middle. One end of the ring-shaped main body is provided with an annular inlet cover, on which symmetrically distributed inlet pipes are provided. The other end of the ring-shaped main body is provided with an annular exhaust cover, on which symmetrically distributed exhaust pipes are provided. The interior of the ring-shaped main body is provided with a reaction chamber for the ammonia decomposition hydrogen production reaction, and a first temperature sensor for monitoring the reaction chamber is also provided in the ring-shaped main body.

3. The vehicle-mounted internal and external self-heating ammonia conversion hydrogen production system according to claim 2, characterized in that, The self-heating device includes an annular hollow combustion chamber for supplying hydrogen mixture for oxidation reaction. The interior of the combustion chamber is divided into different areas by a partition baffle, and the partition baffle is fixed to the inside of the combustion chamber by welding. The hydrogen inlet and the air inlet are both perpendicular to the outer shell of the self-heating device and have an angle between them. An ignition switch is provided on the bisector of the angle between them.

4. The on-board self-heating ammonia-to-hydrogen conversion system according to claim 3, characterized in that, The self-heating device is also covered with an annular heat-insulating shell.

5. The on-board self-heating ammonia-to-hydrogen conversion system according to claim 1, characterized in that, The ammonia supply unit includes a liquid ammonia tank, which is connected to a vaporization device, and the vaporization device is connected to the air inlet pipe via a pipeline.

6. The vehicle-mounted internal and external self-heating ammonia conversion hydrogen production system according to claim 3, characterized in that, Both the annular air intake cover and the annular exhaust cover are connected to the main body of the annular device by bolts, and the self-heating device is also installed on the main body of the annular device by bolts.

7. A control method for an on-board, internally and externally self-heating ammonia conversion hydrogen production system, based on the on-board, internally and externally self-heating ammonia conversion hydrogen production system according to any one of claims 2-4, characterized in that, Includes the following steps: Step 1: Obtain the real-time temperature of the reaction chamber using the first temperature sensor. The real-time ammonia content in the gas storage tank is obtained through an ammonia concentration sensor. The real-time hydrogen content in the gas storage tank is obtained through the first hydrogen concentration sensor. and the obtained , and Transmitted to the electronic control unit; Step 2, , as well as Each value is compared with a preset value: The electronic control unit will obtain The optimal reaction temperature is preset within the reaction chamber. The determination was made, and the ammonia content of the obtained mixed gas was simultaneously measured. and hydrogen content Each concentration is compared with a preset concentration range; Step 3: The electronic control unit determines the device's operating status based on the judgment result, and simultaneously determines whether to activate the self-heating device: If the electronic control unit determines <Minimum operating temperature If the device is in a cold start condition, it is determined that the concentration of ammonia and hydrogen is within the range of cold start conditions. if >Minimum operating temperature ,and <Optimal reaction temperature If the device is in an idling state, it is determined that the condition is met by verifying the ammonia and hydrogen content. If the electronic control unit determines <Optimal reaction temperature If so, the self-heating device will be activated; If the electronic control unit determines >Optimal reaction temperature If so, the self-heating device will not be activated; Step 4: Obtain the real-time temperature of the combustion chamber using the second temperature sensor. The real-time intake volume of hydrogen is obtained through a hydrogen flow sensor. The real-time air intake volume is obtained through an air flow sensor. The real-time pressure of the combustion chamber is obtained through a chamber pressure sensor. The real-time hydrogen concentration in the hydrogen storage tank is obtained through a second hydrogen concentration sensor. and the rate of decrease in hydrogen concentration over time The real-time pressure of the hydrogen storage tank is obtained through a pressure sensor. And transmit each data to the electronic control unit; Step 5, , , , , , as well as Each value is compared with a preset value: The electronic control unit adjusts the judgment values ​​of various parameters based on the working state determined in step 3. First, the electronic control unit obtains... With optimal heating temperature Make a judgment; Secondly, the electronic control unit according to and The difference is used to determine the required combustion intensity, and then different preset values ​​for intake volume are set. The electronic control unit will then obtain and Preset flow rates corresponding to different combustion intensities and Make a judgment; During this process, the electronic control unit will obtain the data in real time. With the maximum permissible pressure value of the combustion chamber The determination is made as follows: Under cold start conditions, the hydrogen required for combustion is provided only by the hydrogen temporarily stored in the hydrogen storage tank; under idling conditions, the electronic control unit will determine the required hydrogen. With the projected hydrogen consumption rate The determination will be made; at the same time, the electronic control unit will also receive... and The hydrogen concentration allowed by the preset hydrogen storage tank is respectively... and maximum warning pressure value Make a judgment; Step 6: The electrical control unit determines the opening degree and opening / closing time of each servo valve based on its current working status and judgment results, and simultaneously determines whether to start the negative pressure unit. If the electronic control unit determines <Optimal heating temperature If so, increase the opening of the hydrogen control valve and the air control valve; If the electronic control unit determines >Optimal heating temperature If so, the opening degree of the hydrogen control valve and the air control valve is reduced, and if the electronic control unit determines at this time... <Maximum permissible pressure value of combustion chamber Then, while ensuring pressure safety, reduce the opening of the exhaust control valve and increase the residence time t of the high-temperature gas until... <Optimal heating temperature Then, immediately increase the opening of the exhaust control valve to discharge the low-temperature exhaust gas, and repeat the above judgment process; The electronic control unit synchronously matches different intake standards based on the combustion intensity determined in step 5: If the electronic control unit determines Optimal hydrogen intake If so, increase the opening of the hydrogen control valve; If the electronic control unit determines >Optimal hydrogen intake Reduce the opening of the hydrogen control valve, and at the same time, adjust the opening of the air control valve according to the combustion intensity to provide sufficient air. If the electronic control unit determines >Maximum permissible pressure value of combustion chamber Immediately increase the opening of the exhaust control valve; If the electronic control unit determines >Expected consumption rate If necessary, increase the opening of the hydrogen storage tank inlet control valve and start the negative pressure machine or increase the power of the negative pressure machine; If the electronic control unit determines <Expected consumption rate If necessary, reduce the opening of the hydrogen storage tank inlet control valve and reduce or shut down the negative pressure unit. If the electronic control unit determines >Preset maximum hydrogen concentration in hydrogen storage tank Immediately reduce the opening of the hydrogen storage tank intake control valve and simultaneously increase the engine intake air volume. Step 7, Overpressure Warning and Control: If the electronic control unit determines >Maximum warning pressure value Immediately close the hydrogen storage tank intake control valve to increase the engine's intake air volume, and simultaneously issue an alarm to prompt an increase in engine input power.

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