Vehicle-mounted ammonia conversion hydrogen production device based on tail gas residual energy utilization and control method

Abstract

The application is suitable for the technical field of hydrogen production by ammonia decomposition, and provides a vehicle-mounted ammonia conversion hydrogen production device based on tail gas residual energy utilization and a control method. The device is installed in a high-temperature section of an engine exhaust pipe and comprises an annular device body containing multiple inner cavities, an inner container filled with an ammonia decomposition reaction catalyst, an annular air inlet cover shell provided with an air inlet pipeline, and an annular air outlet cover shell provided with an air outlet pipeline. A through-type tail gas flow passage is arranged in the center of the annular device body. The outer wall of the inner container is symmetrically provided with MCH ceramic electric heating sheets in sections. The annular air inlet cover shell and the annular air outlet cover shell are tightly installed at the two ends of the annular device body, respectively. The ammonia gas flow direction in the inner container is opposite to the tail gas flow direction in the tail gas flow passage, thereby increasing the heat utilization efficiency. The device can execute different control strategies under different working conditions, matches different vehicle operating conditions, has high adaptability, and has good use effect.

Description

Technical Field

[0001] This invention belongs to the field of ammonia decomposition hydrogen production technology, and particularly relates to an on-board ammonia conversion hydrogen production device and control method based on the utilization of waste energy from exhaust gas. Background Technology

[0002] Against the backdrop of a global low-carbon transition, replacing traditional gasoline-powered vehicles with ammonia is of paramount importance for the green transformation of the transportation industry due to the enormous carbon dioxide and ammonia emissions from these vehicles. Ammonia, as a clean and carbon-free energy source, has attracted widespread attention. Ammonia possesses high energy density and advantages such as easy liquefaction, convenient transportation, and zero pollution, making it considered a high-quality carbon-free fuel. Furthermore, the global ammonia production capacity of 100 million tons per year provides a substantial material basis for its use as fuel.

[0003] However, ammonia itself has a slow laminar flame velocity, a small combustion zone, and poor combustion performance when burned alone, requiring an oxidizer when used as a fuel. Research shows that adding hydrogen, which has better combustion performance, to ammonia can effectively improve the combustion of ammonia fuel, increase the combustion speed, and broaden the flammability limit, without producing carbon dioxide. Therefore, hydrogenation is a reasonable and effective way to simultaneously achieve carbon-free combustion and enhance the ammonia flame. However, because hydrogen itself is not suitable for storage and transportation and has a high risk of leakage, how to utilize hydrogen as an oxidizer in vehicle scenarios remains a challenge. But since ammonia can be decomposed into hydrogen, if ammonia is decomposed into hydrogen in real time as an oxidizer, the problem of hydrogen storage in vehicles can be effectively solved.

[0004] Ammonia decomposition is an endothermic process, requiring a catalyst and a high-temperature environment. Existing ammonia decomposition hydrogen production units all include combustion units, which, whether self-heating or other heating methods, are overly complex and have low hydrogen production efficiency. Therefore, a vehicle-mounted ammonia-to-hydrogen conversion unit is needed that is simple in structure, economical, has high conversion efficiency, can continuously provide a high-temperature environment for ammonia cracking, and can achieve different ammonia-to-hydrogen ratios. Summary of the Invention

[0005] The purpose of this invention is to provide an on-board ammonia-to-hydrogen conversion device and control method based on exhaust gas waste energy utilization, aiming to solve the problems mentioned in the background art.

[0006] The present invention is implemented as follows: an on-board ammonia-to-hydrogen device based on exhaust gas waste energy utilization includes an annular device body. One end of the annular device body is provided with an annular air intake cover. The annular air intake cover is provided with a first air intake pipe and a second air intake pipe, which are symmetrically distributed on both sides of the annular air intake cover. An annular exhaust cover is installed at the end of the annular device body away from the annular air intake cover. The annular exhaust cover is provided with a first exhaust pipe and a second exhaust pipe, which are symmetrically distributed on both sides of the annular exhaust cover. The annular device body has multiple inner cavities arranged in a ring inside. Each inner cavity is equipped with an inner liner for ammonia decomposition reaction. The inner wall of the inner liner is coated with a catalyst, and an MCH ceramic electric heating element is provided between the inner cavity and the inner liner.

[0007] One-way valves are provided on the first intake pipe, the second intake pipe, the first exhaust pipe, and the second exhaust pipe;

[0008] The first and second air intake pipes are both connected to an air intake buffer chamber. The air intake buffer chamber is connected to the air intake end of the inner cavity, and a one-way valve is also provided at the connection between the air intake buffer chamber and the air intake end of the inner cavity.

[0009] The main body of the annular device has a through-type exhaust gas flow channel at its center.

[0010] Inside the annular air intake cover, a first baffle and a second baffle are provided through its center in a direction perpendicular to the line connecting the first air intake pipe and the second air intake pipe.

[0011] The outer periphery of the ring-shaped device is covered with an insulation layer.

[0012] Further technical solutions also include:

[0013] The vehicle-mounted ammonia tank is connected to the first air intake pipe and the second air intake pipe respectively, and the vehicle-mounted ammonia tank is also equipped with an outlet servo valve and a first flow meter.

[0014] A pyrolysis gas volume chamber is connected to a first exhaust pipe and a second exhaust pipe, and a second flow meter is installed between the pyrolysis gas volume chamber and the two exhaust pipes. An ammonia concentration sensor and a hydrogen concentration sensor are installed in the pyrolysis gas volume chamber. The pyrolysis gas volume chamber is also connected to a hydrogen purification device, which is used to output purified hydrogen. A hydrogen valve is connected to the output end of the hydrogen purification device, and a pressure sensor is installed between the hydrogen valve and the hydrogen purification device.

[0015] The hydrogen purification device is also connected to a small hydrogen storage device. By setting up the small hydrogen storage device, it is possible to avoid the ammonia decomposition device being unable to provide sufficient hydrogen in the initial stage of startup. The output end of the small hydrogen storage device is connected to a pressure sensor, and a hydrogen storage device valve is also set between the small hydrogen storage device and the pressure sensor.

[0016] In a further technical solution, the main body of the annular device, the annular air inlet cover, and the annular exhaust cover are all made of aluminum alloy with good thermal conductivity and corrosion resistance.

[0017] In a further technical solution, the cross-sections of both the first exhaust pipe and the second exhaust pipe are elliptical.

[0018] In a further technical solution, bolt mounting holes are provided on the outer circumference of both ends of the ring device body, and bolt hole supports matching the positions of the bolt mounting holes are also provided on the ring device body. The ring air inlet cover and the ring exhaust cover are both fixedly connected to the ring device body by bolts, and sealing gaskets are provided on the contact surfaces between the components.

[0019] In a further technical solution, both the first baffle and the second baffle are connected to the annular air intake cover by welding.

[0020] A further technical solution is that a first temperature sensor is provided at the air inlet end of the inner liner, a second temperature sensor is provided at the air outlet end of the inner liner, and a main temperature sensor is provided in the middle of the inner liner, which can monitor the temperature of each section of the inner liner in real time, thereby facilitating precise adjustment of the temperature of the inner liner.

[0021] In a further technical solution, the MCH ceramic electric heating element is installed in the annular space reserved between the inner liner and the inner cavity, and the MCH ceramic electric heating element is equidistantly distributed in the inlet section, middle section and outlet section of a single inner cavity, so as to provide different thermal atmospheres by controlling the heating position.

[0022] Another objective of this invention is to provide a control method for an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, comprising the following steps:

[0023] Step 1: Acquire real-time temperature, real-time exhaust flow, real-time hydrogen content in the air-fuel mixture, and real-time intake pressure at different locations within the engine liner, and transmit these data to the Electronic Control Unit (ECU). Specifically:

[0024] The main temperature sensor, the first temperature sensor, and the second temperature sensor will acquire the real-time temperature T of the inner liner. a The second flow meter will acquire the real-time exhaust flow rate Q. out-a The hydrogen concentration sensor will acquire the real-time hydrogen content. The pressure sensor will acquire the real-time intake pressure Pa ;

[0025] Step 2, Real-time temperature of the inner liner T a Real-time exhaust flow rate Q out-a and the real-time hydrogen content in the gas mixture Determination against preset values:

[0026] The electronic control unit (ECU) prioritizes the acquisition of real-time temperatures T of different sections of the inner liner. a With the preset inner liner temperature T 0default A judgment is made, and then the real-time exhaust flow rate Q is analyzed. out-a Preset values ​​of exhaust flow rate Q under different operating conditions out-default The determination is made, and finally the hydrogen content of the mixed gas is... Preset values ​​of hydrogen content under different operating conditions Make a judgment;

[0027] Step 3: The Electronic Control Unit (ECU) determines the operating status based on the judgment result and decides whether to activate the MCH ceramic electric heating element.

[0028] If the electronic control unit (ECU) determines the real-time temperature T of the inner liner a ≤T 0default Then the MCH ceramic electric heating element is activated, and the power of the MCH ceramic electric heating element in different sections is adjusted according to the different temperatures in different parts of the inner liner to maintain the temperature uniformity of the entire inner liner.

[0029] If the electronic control unit (ECU) determines the real-time temperature T of the inner liner a >T 0default If the temperature is below a certain level, the MCH ceramic heating element will not be activated; specifically, when the real-time temperature T... a <T 0min (Minimum operating temperature preset value), the device is in cold start state; when the real-time temperature T a >T 0min And T a <T 0default At that time, the device is in idle state; when the real-time temperature T a >T 0default And T a <T 0normal When the normal operating temperature is preset, the device is under medium load; when the real-time temperature T... a >T 0normal And T a <T 0max When the (preset maximum operating temperature) is reached, the device is in acceleration, high load, or full load mode.

[0030] Step 4: The Electronic Control Unit (ECU) determines the servo switch opening degree and the number of working inner tubes based on the judgment result.

[0031] If the electronic control unit (ECU) determines the real-time exhaust flow rate Q out-a ≤Preset value of exhaust flow Q out-default If the intake servo valve opening is increased, the electronic control unit (ECU) will determine the real-time exhaust flow rate Q. out-a >Preset value of exhaust flow Q out-default If the ECU determines the real-time hydrogen content, then reduce the opening of the intake servo valve; This increases the number of working linings; if the electronic control unit (ECU) determines in real time... This reduces the workload of the inner liner;

[0032] Step 5, Low supply alarm during idling:

[0033] If the electronic control unit (ECU) determines the engine intake pressure P a <P alarmvalue If the intake pressure alarm value is reached, the ECU will issue an alarm, prompting an increase in input power.

[0034] The present invention provides an on-board ammonia-to-hydrogen conversion device and control method based on exhaust gas waste energy utilization, the beneficial effects of which are as follows:

[0035] (1) The device has the advantages of controllability, energy saving and high efficiency. In terms of heating, it uses two methods: electric heating and exhaust gas residual heat heating. It can maintain a high temperature atmosphere under different conditions, and the energy saving effect is obvious. At the same time, it uses the high temperature hot exhaust gas and low temperature cold ammonia gas to carry out inter-wall heat exchange in the counter-flow mode, which enhances the heat transfer efficiency and improves the residual energy utilization capacity.

[0036] (2) By setting spiral baffles inside the channel, secondary flow can be triggered, wall-side flow can be strengthened, heat transfer can be enhanced, shell-side pressure drop can be reduced, flow velocity and flow uniformity can be increased, and the flow dead zone can be reduced. This can effectively ensure that the exhaust gas flow is stable and unobstructed after the device is applied to the automobile exhaust pipe, thereby extending the exhaust gas flow distance, increasing the heat exchange time and convective heat transfer coefficient, thereby improving the exhaust gas heat utilization efficiency of the device and reducing energy loss;

[0037] (3) By uniformly segmenting multiple MCH ceramic electric heating elements on the inner liner, temperature control at different locations is achieved, providing a uniform, stable and real-time controllable temperature environment for the ammonia decomposition reaction. At the same time, it solves the problem that the device cannot reach the required reaction temperature during cold start and idling.

[0038] (4) Multiple reaction chambers were set up. By controlling the flow of the reaction chambers, the reaction time and the amount of ammonia introduced, the gas supply and concentration were controlled in real time.

[0039] (5) A dual air inlet is provided, along with symmetrically distributed baffles. This increases the air intake while preventing the decrease in air intake efficiency caused by airflow collision, alleviating the flow differences in each catalytic chamber caused by the varying distances between the inner tank and the air inlet, and avoiding structural conflicts with the waste flow pipeline, thus improving the rationality of the device installation.

[0040] (6) An insulation layer is provided on the outside of the main body of the device, which can improve the utilization efficiency of the residual energy of the tail gas, reduce temperature fluctuations, maintain the stability of the reaction temperature, and improve the reaction efficiency. Attached Figure Description

[0041] Figure 1 A schematic diagram of the structure of an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization provided in an embodiment of the present invention;

[0042] Figure 2 This is a cross-sectional view of an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, provided in an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the external structure of an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, provided in an embodiment of the present invention.

[0044] Figure 4 A schematic diagram of the structure of an annular air intake cover in an on-board ammonia conversion hydrogen production device based on exhaust gas waste energy utilization, provided in an embodiment of the present invention.

[0045] Figure 5 A schematic diagram of the structure of an annular exhaust cover in an on-board ammonia conversion hydrogen production device based on exhaust gas waste energy utilization, provided in an embodiment of the present invention.

[0046] Figure 6 A flowchart illustrating a control method for an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, provided as an embodiment of the present invention.

[0047] In the attached diagram: 1-Onboard ammonia tank; 2-Outlet servo valve; 3-First flow meter; 4-Check valve; 5-MCH ceramic electric heating element; 6-Main temperature sensor; 7-Second flow meter; 8-Ammonia concentration sensor; 9-Cracked gas volume chamber; 10-Hydrogen concentration sensor; 11-Hydrogen purification device; 12-Small hydrogen storage device; 13-Pressure sensor; 14-Hydrogen valve; 15-Hydrogen storage device valve; 16-Annular device body; 17-Annular air inlet cover; 18-Annular exhaust cover; 19-Tail gas flow channel; 20-Inner cavity; 21-Inner liner; 22-First air inlet pipe; 23-Second air inlet pipe; 24-First exhaust pipe; 25-Second exhaust pipe; 26-First baffle; 27-Second baffle; 28-Bolt mounting hole; 29-Bolt hole support; 30-First temperature sensor; 31-Second temperature sensor; 32-Insulation layer. Detailed Implementation

[0048] 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.

[0049] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0050] like Figure 1-5 As shown, an embodiment of the present invention provides an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, comprising an annular device body 16, an annular air intake cover 17 at one end of the annular device body 16, a first air intake pipe 22 and a second air intake pipe 23 disposed on the annular air intake cover 17, and the first air intake pipe 22 and the second air intake pipe 23 symmetrically distributed on both sides of the annular air intake cover 17, and an annular exhaust valve is installed at the end of the annular device body 16 away from the annular air intake cover 17. The annular exhaust cover 18 is provided with a first exhaust pipe 24 and a second exhaust pipe 25, and the first exhaust pipe 24 and the second exhaust pipe 25 are symmetrically distributed on both sides of the annular exhaust cover 18. The annular device body 16 has a plurality of inner cavities 20 arranged in a ring inside, and an inner liner 21 for carrying out ammonia decomposition reaction is installed in the inner cavity 20. The inner wall of the inner liner 21 is coated with a catalyst, and an MCH ceramic electric heating element 5 is provided between the inner cavity 20 and the inner liner 21.

[0051] One-way valves 4 are provided on the first intake pipe 22, the second intake pipe 23, the first exhaust pipe 24, and the second exhaust pipe 25;

[0052] The first air intake pipe 22 and the second air intake pipe 23 are both connected to an air intake buffer chamber. The air intake buffer chamber is connected to the air intake end of the inner cavity 20, and a one-way valve 4 is also provided at the connection between the air intake buffer chamber and the air intake end of the inner cavity 20.

[0053] The main body 16 of the annular device has a through exhaust gas flow channel 19 at its center. The exhaust gas flow channel 19 is equipped with a spiral baffle, and the flow direction of the exhaust gas and ammonia is opposite.

[0054] Inside the annular air intake cover 17, a first baffle 26 and a second baffle 27 are provided through its center perpendicular to the line connecting the first air intake pipe 22 and the second air intake pipe 23.

[0055] The outer periphery of the ring-shaped device body 16 is covered with a heat insulation layer 32.

[0056] In this embodiment of the invention, the device only needs to be installed in the high-temperature section of the vehicle's exhaust pipe to utilize the residual energy of the exhaust gas for heating. Specifically, during operation:

[0057] Ammonia gas enters the intake buffer chamber through the first intake pipe 22 and the second intake pipe 23. The flow rate of ammonia gas into the inner liner 21 is controlled by the one-way valve 4 at the intake end of the inner cavity 20. As the ammonia gas flows into the inner liner 21, it is heated by residual exhaust energy and the hot atmosphere provided by the MCH ceramic electric heating element 5, and undergoes a high-temperature cracking reaction with the catalyst coated on the inner wall of the inner liner 21 to form a mixture of ammonia, hydrogen, and nitrogen. This mixture is then discharged through the first exhaust pipe 24 and the second exhaust pipe 25. The ratio and flow rate of the ammonia-hydrogen mixture can be controlled by adjusting the heating power of the MCH ceramic electric heating element 5 and the intake flow rate of the one-way valve 4 to obtain the required ammonia-hydrogen mixture. This allows for the supply of different proportions of ammonia-hydrogen mixture to the engine according to different operating conditions of the vehicle.

[0058] In a preferred embodiment of the present invention, the annular device body 16, the annular air inlet cover 17, and the annular exhaust cover 18 are all made of aluminum alloy with good thermal conductivity and corrosion resistance.

[0059] In a preferred embodiment of the present invention, the material of the inner liner 21 is carefully divided. An alloy such as iron-chromium-aluminum is used at the air inlet end of the inner liner 21 to avoid corrosion from ammonia gas; hydrogen-resistant steel is used at the exhaust end of the inner liner 21 to prevent hydrogen erosion under high temperature and pressure. This extends the service life while improving product purity.

[0060] In a preferred embodiment of the present invention, the cross-sections of the first exhaust pipe 24 and the second exhaust pipe 25 are both elliptical.

[0061] In a preferred embodiment of the present invention, bolt mounting holes 28 are provided on the outer circumference of both ends of the annular device body 16, and bolt hole supports 29 matching the positions of the bolt mounting holes 28 are also provided on the annular device body 16. The annular air intake cover 17 and the annular exhaust cover 18 are both fixedly connected to the annular device body 16 by bolts, and sealing gaskets are provided on the contact surfaces between the components.

[0062] In a preferred embodiment of the present invention, the first baffle 26 and the second baffle 27 are both connected to the annular air intake cover 17 by welding.

[0063] In a preferred embodiment of the present invention, a first temperature sensor 30 is provided at the air inlet end of the inner liner 21, a second temperature sensor 31 is provided at the exhaust end of the inner liner 21, and a main temperature sensor 6 is provided in the middle of the inner liner 21, which can monitor the temperature of each section of the inner liner 21 in real time, thereby facilitating precise adjustment of the temperature of the inner liner 21.

[0064] In a preferred embodiment of the present invention, the MCH ceramic electric heating element 5 is installed within the annular space reserved between the inner liner 21 and the inner cavity 20, and the MCH ceramic electric heating element 5 is equidistantly distributed in the inlet, middle, and outlet sections of a single inner cavity 20. Different thermal atmospheres are provided by controlling the heating position.

[0065] As a preferred embodiment of the present invention, it further includes:

[0066] The vehicle-mounted ammonia tank 1 (or liquid ammonia tank and vaporization device if liquid ammonia is used) is connected to the first air inlet pipe 22 and the second air inlet pipe 23 respectively, and the vehicle-mounted ammonia tank 1 is also equipped with an outlet servo valve 2 and a first flow meter 3.

[0067] A cracked gas volume chamber 9 is connected to a first exhaust pipe 24 and a second exhaust pipe 25, and a second flow meter 7 is installed between the cracked gas volume chamber 9 and the two exhaust pipes. An ammonia concentration sensor 8 and a hydrogen concentration sensor 10 are installed in the cracked gas volume chamber 9. The cracked gas volume chamber 9 is also connected to a hydrogen purification device 11, which is used to output purified hydrogen. A hydrogen valve 14 is connected to the output end of the hydrogen purification device 11, and a pressure sensor 13 is installed between the hydrogen valve 14 and the hydrogen purification device 11.

[0068] The hydrogen purification device 11 is also connected to a small hydrogen storage device 12. By setting up the small hydrogen storage device 12, the ammonia decomposition device can avoid being unable to provide sufficient hydrogen in the initial stage of startup. The output end of the small hydrogen storage device 12 is connected to the pressure sensor 13, and a hydrogen storage device valve 15 is also provided between the small hydrogen storage device 12 and the pressure sensor 13.

[0069] like Figure 6 As shown, a control method for an on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, according to an embodiment of the present invention, includes the following steps:

[0070] Step 1: Obtain real-time temperature, real-time exhaust flow, real-time hydrogen content in the air-fuel mixture, and real-time intake pressure at different locations within the inner tank 21, and transmit these data to the Electronic Control Unit (ECU). Specifically:

[0071] The main temperature sensor 6, the first temperature sensor 30, and the second temperature sensor 31 will acquire the real-time temperature T of the inner liner 21. a The second flow meter 7 will acquire the real-time exhaust flow rate Q. out-a The hydrogen concentration sensor 10 will acquire the real-time hydrogen content. Pressure sensor 13 will acquire the real-time intake pressure P a ;

[0072] Step 2, Real-time temperature of the inner liner T a Real-time exhaust flow rate Q out-a and the real-time hydrogen content in the gas mixture Determination against preset values:

[0073] The electronic control unit (ECU) prioritizes the acquisition of real-time temperatures T of different sections of the inner liner 21. a With the preset inner liner temperature T 0default Make a judgment, and then check the real-time exhaust flow rate Q. out-a Preset values ​​of exhaust flow rate Q under different operating conditions out-default The determination is made, and finally the hydrogen content of the mixed gas is assessed. Preset values ​​of hydrogen content under different operating conditions Make a judgment;

[0074] Step 3: The Electronic Control Unit (ECU) determines the operating status based on the judgment result and decides whether to activate the MCH ceramic electric heating element 5.

[0075] If the electronic control unit (ECU) determines the real-time temperature T of the inner liner a ≤T 0default If the temperature is high, the MCH ceramic electric heating element 5 will be activated. At the same time, the power of the MCH ceramic electric heating element 5 in different sections will be adjusted according to the different temperatures at different locations in the inner liner 21 to maintain the temperature uniformity of the entire inner liner 21.

[0076] If the electronic control unit (ECU) determines the real-time temperature T of the inner liner a >T 0default If the temperature is below a certain level, the MCH ceramic heating element 5 will not be activated; specifically, when the real-time temperature T... a <T0min (Minimum operating temperature preset value), the device is in cold start state; when the real-time temperature T a >T 0min And T a <T 0default At that time, the device is in idle state; when the real-time temperature T a >T 0default And T a <T 0normal When the normal operating temperature is preset, the device is under medium load; when the real-time temperature T... a >T 0normal And T a <T 0max When the (preset maximum operating temperature) is reached, the device is in acceleration, high load, or full load mode.

[0077] Step 4: The Electronic Control Unit (ECU) determines the servo switch opening degree and the number of working inner tubes based on the judgment result.

[0078] If the electronic control unit (ECU) determines the real-time exhaust flow rate Q out-a ≤Preset value of exhaust flow Q out-default If the intake servo valve opening is increased, the electronic control unit (ECU) will determine the real-time exhaust flow rate Q. out-a >Preset value of exhaust flow Q out-default If the ECU determines the real-time... This increases the number of working linings; if the electronic control unit (ECU) determines in real time... This reduces the workload of the inner liner;

[0079] Step 5, Low supply alarm during idling:

[0080] If the electronic control unit (ECU) determines the engine intake pressure P a <P alarmvalue If the intake pressure alarm value is reached, the ECU will issue an alarm, prompting an increase in input power.

[0081] 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 ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization, characterized in that, The device includes a ring-shaped main body, with an annular air inlet cover at one end. A first air inlet pipe and a second air inlet pipe are provided on the annular air inlet cover, symmetrically distributed on both sides of the cover. An annular exhaust cover is installed at the end of the main body away from the air inlet cover, with a first exhaust pipe and a second exhaust pipe provided on the exhaust cover, symmetrically distributed on both sides of the exhaust cover. The main body has multiple inner cavities arranged in a ring, each containing an inner liner for ammonia decomposition. The inner wall of the inner liner is coated with a catalyst, and an MCH ceramic electric heating element is positioned between the inner cavity and the inner liner. One-way valves are provided on the first intake pipe, the second intake pipe, the first exhaust pipe, and the second exhaust pipe; The first and second air intake pipes are both connected to an air intake buffer chamber. The air intake buffer chamber is connected to the air intake end of the inner cavity, and a one-way valve is also provided at the connection between the air intake buffer chamber and the air intake end of the inner cavity. The main body of the annular device has a through-type exhaust gas flow channel at its center. Inside the annular air intake cover, a first baffle and a second baffle are provided through its center perpendicular to the line connecting the first air intake pipe and the second air intake pipe.

2. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 1, characterized in that, Also includes: The vehicle-mounted ammonia tank is connected to the first air intake pipe and the second air intake pipe respectively, and the vehicle-mounted ammonia tank is also equipped with an outlet servo valve and a first flow meter. A pyrolysis gas volume chamber is connected to a first exhaust pipe and a second exhaust pipe, and a second flow meter is installed between the pyrolysis gas volume chamber and the two exhaust pipes. An ammonia concentration sensor and a hydrogen concentration sensor are installed in the pyrolysis gas volume chamber. The pyrolysis gas volume chamber is also connected to a hydrogen purification device, which is used to output purified hydrogen. A hydrogen valve is connected to the output end of the hydrogen purification device, and a pressure sensor is installed between the hydrogen valve and the hydrogen purification device. The hydrogen purification device is also connected to a small hydrogen storage device. The output end of the small hydrogen storage device is connected to a pressure sensor, and a hydrogen storage device valve is also provided between the small hydrogen storage device and the pressure sensor.

3. The on-board ammonia conversion hydrogen production device based on exhaust gas waste energy utilization according to claim 2, characterized in that, The outer periphery of the ring-shaped device is covered with an insulation layer.

4. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 2, characterized in that, The main body of the annular device, the annular air inlet cover, and the annular exhaust cover are all made of aluminum alloy, which has both thermal conductivity and corrosion resistance.

5. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 2, characterized in that, The cross-sections of both the first and second exhaust pipes are elliptical.

6. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 2, characterized in that, Bolt mounting holes are provided on the outer circumference of both ends of the ring device body, and bolt hole supports matching the positions of the bolt mounting holes are also provided on the ring device body. The ring air inlet cover and the ring exhaust cover are fixedly connected to the ring device body by bolts, and sealing gaskets are provided on the contact surfaces between the components.

7. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 2, characterized in that, Both the first baffle and the second baffle are connected to the annular air intake cover by welding.

8. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 2, characterized in that, The MCH ceramic electric heating element is installed in the annular space reserved between the inner liner and the inner cavity, and the MCH ceramic electric heating element is equidistantly distributed in the inlet section, middle section and outlet section of a single inner cavity.

9. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to claim 8, characterized in that, The inner liner is equipped with a first temperature sensor at the air inlet end, a second temperature sensor at the air outlet end, and a main temperature sensor in the middle of the inner liner.

10. The on-board ammonia-to-hydrogen conversion device based on exhaust gas waste energy utilization according to any one of claims 2-9, characterized in that, The control method of the device includes the following steps: Step 1: Acquire real-time temperature, real-time exhaust flow, real-time hydrogen content in the air-fuel mixture, and real-time intake pressure at different locations within the engine liner, and transmit these data to the Electronic Control Unit (ECU). Specifically: The main temperature sensor, the first temperature sensor, and the second temperature sensor will acquire the real-time temperature T of the inner liner. a The second flow meter will acquire the real-time exhaust flow rate Q. out-a The hydrogen concentration sensor will acquire the real-time hydrogen content. The pressure sensor will acquire the real-time intake pressure P a ; Step 2, Real-time temperature of the inner liner T a Real-time exhaust flow rate Q out-a and the real-time hydrogen content in the gas mixture Determination against preset values: The electronic control unit (ECU) prioritizes the acquisition of real-time temperatures T of different sections of the inner liner. a With the preset inner liner temperature T 0default A judgment is made, and then the real-time exhaust flow rate Q is analyzed. out-a Preset values ​​of exhaust flow rate Q under different operating conditions out-default The determination is made, and finally the hydrogen content of the mixed gas is... Preset values ​​of hydrogen content under different operating conditions Make a judgment; Step 3: The Electronic Control Unit (ECU) determines the operating status based on the judgment result and decides whether to activate the MCH ceramic electric heating element. If the electronic control unit (ECU) determines the real-time temperature T of the inner liner a ≤T 0default Then the MCH ceramic electric heating element is activated, and the power of the MCH ceramic electric heating element in different sections is adjusted according to the different temperatures in different parts of the inner liner to maintain the temperature uniformity of the entire inner liner. If the electronic control unit (ECU) determines the real-time temperature T of the inner liner a >T 0default If not, the MCH ceramic heating element will not be activated; When the real-time temperature T a Minimum operating temperature preset value T 0min The device is in a cold start state; when the real-time temperature T a >T 0min And T a <T 0default At that time, the device is in idle state; when the real-time temperature T a >T 0default And T a < Normal operating temperature preset value T 0normal At that time, the device was under medium load; when the real-time temperature T a >T 0normal And T a <Maximum operating temperature preset value T 0max At that time, the device is in an accelerated, high-load, or full-load state; Step 4: The Electronic Control Unit (ECU) determines the servo switch opening degree and the number of working inner tubes based on the judgment result. If the electronic control unit (ECU) determines the real-time exhaust flow rate Q out-a ≤Preset value of exhaust flow Q out-default If the intake servo valve opening is increased, the electronic control unit (ECU) will determine the real-time exhaust flow rate Q. out-a >Preset value of exhaust flow Q out-default If the ECU determines the real-time hydrogen content, then reduce the opening of the intake servo valve; ≤ Hydrogen flow rate preset value This increases the number of working elements in the inner liner; if the electronic control unit (ECU) determines the real-time hydrogen content... >Preset hydrogen flow rate This reduces the workload of the inner liner; Step 5, Low supply alarm during idling: If the electronic control unit (ECU) determines the engine intake pressure P a <Intake pressure alarm value P alarmvalue If this happens, the ECU will issue an alarm, prompting an increase in input power.

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