A system and method for on-line ammonia hydrogen production storage for DPF regeneration

Abstract

The present invention discloses a system for ammonia on-line hydrogen production storage for DPF regeneration. The system includes an ammonia fuel tank, an ammonia cracker and its sensor unit; a PAA, a DPF, an SCR and an ASC device are sequentially connected to the exhaust passage along the gas flow discharge direction. The ammonia storage tank is provided with two exhaust ports respectively connected to the front pipeline of the electric heater and the SCR. The ammonia fuel tank is provided with two gas outlets respectively connected to the ammonia cracker and the intake passage; the exhaust port of the ammonia cracker is connected to the hydrogen storage device, and the hydrogen storage device is provided with two gas outlets respectively connected to the intake passage and the DPF device; the sensor unit includes a temperature sensor, a pressure sensor, a nitrogen oxide sensor and an ammonia sensor which are arranged on the exhaust passage and connected to the ECU. The system uses hydrogen as fuel, eliminates the need for additional high-power equipment required by the traditional regeneration system, and can achieve near-zero emissions of harmful pollutants such as particulate matter from an ammonia-diesel dual-fuel engine.

Description

Technical Field

[0001] This invention patent relates to the technical field of the automotive industry, and particularly to a pollutant emission treatment system based on an ammonia-diesel dual-fuel power system (such as an internal combustion engine). Background Art

[0002] Compared with battery technology, internal combustion engines have a compact structure, high thermal efficiency, and are convenient for operation and maintenance, so they are widely used in various scenarios. However, internal combustion engines fueled by traditional fuels will generate a large amount of carbon emissions, and there is an urgent need to develop a new type of internal combustion power system using zero-carbon or carbon-neutral fuels.

[0003] As a carbon-neutral fuel, ammonia can be obtained from fossil fuels, biomass, or other renewable resources. Compared with hydrogen, ammonia is safe and reliable, has a relatively high volumetric energy density, and a relatively low unit energy storage cost. However, ammonia has low activity, slow combustion, a narrow flammable limit, a high ignition energy, and is accompanied by high nitrogen oxide and unburned ammonia emissions. Using a highly reactive fuel to ignite ammonia is an effective combustion method that has received much attention. However, highly reactive fuels such as diesel tend to produce more particulate matter (PM) and nitrogen oxides (NOx) during combustion, which are very harmful to the environment and human body. Therefore, emission regulations in various countries are becoming increasingly strict on the emission limits of PM and NOx. For ammonia-diesel dual-fuel engines, in addition to taking necessary in-cylinder measures to improve combustion, it is also necessary to post-treat and purify emissions such as PM, NOx, and unburned NH3 in the engine exhaust.

[0004] Diesel particulate filter (DPF) is the main post-treatment technical measure to reduce PM emissions. As the engine operating time increases, the amount of particulate matter accumulated in the filter body will increase, which may lead to an increase in the engine exhaust back pressure, and then affect the normal operation of the engine. Therefore, it is usually necessary to remove the particulate matter by means such as combustion, that is, the regeneration technology. The existing main regeneration methods are heating regeneration and fuel injection assisted combustion regeneration, and both types of equipment require additional high-power equipment, which greatly increases the equipment cost and usage cost. Summary of the Invention

[0005] In view of the above-mentioned prior art, the present invention provides a DPF regeneration system applicable to the post-treatment of ammonia-diesel dual-fuel engine emissions, which uses ammonia on-line decomposition to produce hydrogen for storage and use in DPF regeneration. This system uses hydrogen as fuel, taking advantage of the wide flammable range, high combustion temperature, and clean and carbon-free characteristics of hydrogen, eliminating the need for additional high-power equipment required by traditional regeneration systems, and solving the problem of high usage cost and design cost of regeneration equipment in the prior art. This system can achieve near-zero emissions of harmful pollutants such as particulate matter from ammonia-diesel dual-fuel engines.

[0006] To solve the above technical problems, the present invention provides a system for ammonia on-line hydrogen production and storage for DPF regeneration, which includes an ammonia fuel tank, an on-vehicle hydrogen production device and its sensor unit; the ammonia fuel tank is provided with an ammonia storage tank, an electric heater and a pressure stabilizing tank. The on-vehicle hydrogen production device includes an ammonia cracker; the engine is provided with an intake passage and an exhaust passage; on the exhaust passage, in the direction of the gas flow from the connection end with the engine, a passive ammonia adsorber, a diesel particulate filter, a selective catalytic reducer and an ammonia slip catcher are sequentially connected through pipe segments; the connecting pipe segment between the passive ammonia adsorber and the engine is the first pipe segment, the connecting pipe segment between the diesel particulate filter and the passive ammonia adsorber is the second pipe segment, the connecting pipe segment between the selective catalytic reducer and the diesel particulate filter is the third pipe segment, the connecting pipe segment between the ammonia slip catcher and the selective catalytic reducer is the fourth pipe segment, and the discharge port of the ammonia slip catcher is connected to the atmosphere through the fifth pipe segment; the ammonia storage tank is provided with two exhaust ports, one exhaust port is connected to the electric heater, and the other exhaust port is sequentially connected to the third pipe segment through a control butterfly valve A and a low-pressure ammonia nozzle; the ammonia fuel tank is provided with two gas outlets, and the two gas outlets are respectively connected to the intake port of the ammonia cracker and the intake passage; the exhaust port of the ammonia cracker is connected to a hydrogen storage device through a exhaust pipe, the hydrogen storage device is provided with two gas outlets, one gas outlet is connected to the intake passage, and the intake passage is connected to the external air; the other gas outlet is sequentially connected to the diesel particulate filter through a control butterfly valve B and a low-pressure hydrogen nozzle; the sensors included in the sensor unit are: an exhaust temperature sensor provided on the first pipe segment, exhaust pressure sensors respectively provided on the second pipe segment and the third pipe segment, nitrogen oxide sensors and ammonia sensors respectively provided on the third pipe segment and the fifth pipe segment; all the sensors in the passive ammonia adsorber, the diesel particulate filter, the selective catalytic reducer, the ammonia slip catcher, the control butterfly valve A, the control butterfly valve B, the electric heater, the on-vehicle hydrogen production device and the sensor unit are connected to the ECU of the engine.

[0007] Furthermore, in the system for ammonia on-line hydrogen production and storage for DPF regeneration according to the present invention:

[0008] The two gas outlets provided on the ammonia fuel tank are respectively a first gas outlet and a second gas outlet. The first gas outlet is connected to the intake air rail to provide ammonia for fuel; the second gas outlet is connected to the ammonia cracker, and the ammonia cracker catalytically cracks part of the ammonia to produce hydrogen.

[0009] The passive ammonia adsorber is provided with a PAA carrier and a coating. The passive ammonia adsorber adopts an ion exchange process to adsorb and store NH3 in the low-temperature / cold start stage of the engine and gradually desorb NH3 in the normal exhaust temperature stage of the engine.

[0010] The diesel particulate filter includes a housing, and a DPF filter element is arranged inside the housing. The DPF filter element is open at one side of the front end of the housing, and filter element working surfaces are arranged at positions except the open end. A spark plug penetrating through the housing and the filter element working surfaces is arranged on the side wall of the diesel particulate filter. The low-pressure hydrogen nozzle is arranged on the side wall of the housing at the side of the open end. The low-pressure hydrogen nozzle penetrates through the housing and the filter element working surfaces. Flanges are respectively arranged at the front and rear ends of the housing for installing the diesel particulate filter in the exhaust pipe between the passive ammonia adsorber and the selective catalytic reducer.

[0011] An SCR carrier and a coating are arranged in the selective catalytic reducer;

[0012] An ASC carrier and a coating are arranged in the ammonia slip trap. The coating is a noble metal coating with a molecular-level pore diameter, adsorbs NH3, and catalytically oxidizes and decomposes it into N2 and H2O.

[0013] Meanwhile, the present invention also provides a method for realizing DPF regeneration by using the above ammonia on-line hydrogen production storage system for DPF regeneration. Specifically: when the engine is running, the exhaust gas of the engine passes through the vehicle-mounted hydrogen production device, and part of the exhaust gas waste heat is supplied to the ammonia cracker. The H2 generated in the ammonia cracker is introduced into the hydrogen storage device for storage. At the same time, the ECU of the engine judges whether the DPF needs regeneration according to the exhaust pressure sensor signal. If regeneration is needed, the control butterfly valve B is opened, and the low-pressure hydrogen nozzle is controlled to spray H2 into the diesel particulate filter to realize regeneration. When the engine is running, the ECU of the engine controls the ammonia storage tank to inject ammonia into the third pipe section between the diesel particulate filter and the selective catalytic reducer according to the NOx and NH3 concentration signals collected by the nitrogen oxide sensor and the ammonia sensor, mixes it with the tail gas, and then realizes reduction in the selective catalytic reducer. The reaction equations are: 4NH3 + 4N2O + O2 → 6N2 + 6H2O; 4NH3 + 2NO + O2 → 3N2 + 6H2O; 8NH3 + 6NO2 → 7N2 + 12H2O.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The ammonia storage tank in the present invention can directly inject ammonia into the exhaust pipe in front of the SCR under the control of the ECU, mix it fully with the tail gas, and catalytically reduce it in the subsequent SCR device, without the need to be additionally equipped with a urea tank and a urea nozzle, greatly optimizing the structure of the aftertreatment system.

[0016] The DPF regeneration system in the present invention omits the fuel injector assembly, only installs the igniter assembly, reformats and stores hydrogen on-line by using a small reformer, and sprays it into the burner through a simple air valve.

[0017] The present invention uses hydrogen as the regeneration energy source. By taking advantage of the wide flammable range and high combustion temperature of hydrogen, it eliminates the need for the large - power supercharging equipment that the traditional regeneration system needs to be equipped with additionally.

[0018] The traditional DPF regeneration system uses diesel as the regeneration energy source. During the regeneration process, emissions such as carbon monoxide (CO) and hydrocarbons (HC) may be generated, and subsequent devices such as SCR cannot handle them. By using hydrogen as the regeneration energy source, it has a high combustion temperature, faster response, and the possible NOx emissions can be directly treated in the subsequent SCR device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the system for on - line hydrogen production and storage for DPF regeneration of the present invention;

[0020] Figure 2 is a schematic diagram of the exhaust passage and the after - treatment system in the system of the present invention;

[0021] Figure 3 is a schematic diagram of the structure of the diesel particulate filter in the present invention.

[0022] In the figure:

[0023] A - First control butterfly valve, B - Second control butterfly valve, 1 - First pipe segment

[0024] 2 - Fifth pipe segment, 3 - Exhaust gas temperature sensor, 4 - Passive ammonia adsorber

[0025] 5 - First exhaust gas pressure sensor, 6 - Low - pressure hydrogen nozzle, 7 - Diesel particulate filter

[0026] 8 - Second exhaust gas pressure sensor, 9 - Low - pressure ammonia nozzle, 10 - Selective catalytic reducer

[0027] 11 - Fourth pipe segment, 12 - Second nitrogen oxide sensor, 13 - Second ammonia sensor

[0028] 14 - First pipe segment, 15 - PAA carrier and coating, 16 - Spark plug

[0029] 17 - DPF filter screen, 18 - First nitrogen oxide sensor, 19 - First ammonia sensor

[0030] 20 - Third pipe segment, 21 - SCR carrier and coating, 22 - ASC carrier and coating

[0031] 23 - Ammonia slip trap, 24 - Outer shell, 25 - DPF filter element

[0032] 26 - Rear flange, 27 - Spark plug, 28 - Front flange Detailed implementation manners

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means any limitation to the present invention.

[0034] A system for on-vehicle hydrogen production and storage from ammonia for DPF regeneration proposed by the present invention is as Figure 1 and Figure 2 shown. The system includes an ammonia fuel tank, an on-vehicle hydrogen production device and its sensor unit; the ammonia fuel tank is provided with an ammonia storage tank, an electric heater and a pressure stabilizing tank. The on-vehicle hydrogen production device includes an ammonia cracker; the engine is provided with an intake passage and an exhaust passage.

[0035] On the exhaust passage, sequentially connected along the gas flow discharge direction from the connection end with the engine through pipe segments are a passive ammonia adsorber (PAA) 4, a diesel particulate filter (DPF) 7, a selective catalytic reduction device (SCR) 10 and an ammonia slip catalyst (ASC) 23; the connection pipe segment between the passive ammonia adsorber 4 and the engine is the first pipe segment 14, the connection pipe segment between the diesel particulate filter 7 and the passive ammonia adsorber 4 is the second pipe segment 1, the connection pipe segment between the selective catalytic reduction device 10 and the diesel particulate filter 7 is the third pipe segment 20, the connection pipe segment between the ammonia slip catalyst 23 and the selective catalytic reduction device 10 is the fourth pipe segment 11, and the discharge port of the ammonia slip catalyst 23 is connected to the atmosphere through a fifth pipe segment.

[0036] The ammonia storage tank is provided with two exhaust ports, one exhaust port is connected to the electric heater, and the other exhaust port is sequentially connected to the third pipe segment 20 through a control butterfly valve A and a low-pressure ammonia nozzle 9.

[0037] The ammonia fuel tank is provided with two gas outlets, and the two gas outlets are respectively connected to the intake port of the ammonia cracker and the intake passage. Specifically, the two gas outlets provided by the ammonia fuel tank are respectively a first gas outlet and a second gas outlet. The first gas outlet is connected to the intake air rail to provide fuel ammonia for the on-vehicle hydrogen production device; the second gas outlet is connected to the ammonia cracker. The catalyst in the ammonia cracker can be the ruthenium supported on magnesium oxide catalyst provided in the patent document CN108160072A. The ammonia cracker catalytically cracks part of the ammonia to generate hydrogen. The exhaust port of the ammonia cracker is connected to the hydrogen storage device through an exhaust pipe.

[0038] The hydrogen storage device is provided with two gas outlets. One gas outlet is connected to the intake passage. When the engine is cold-started, under the control of the ECU, according to the exhaust temperature sensor on the exhaust pipe, the hydrogen storage device can control the excess hydrogen to enter the intake passage and mix with ammonia to form an ammonia-hydrogen mixture, so as to enter the combustion chamber to improve engine combustion; the intake passage is connected to the external air; the other gas outlet is sequentially connected to the diesel particulate filter 7 through the control butterfly valve B and the low-pressure hydrogen nozzle 6, and hydrogen can be introduced into the diesel particulate filter 7 to achieve DPF regeneration.

[0039] The passive ammonia adsorber 4 is filled with a PAA carrier and a coating 15. The passive ammonia adsorber 4 adopts an ion exchange process to adsorb and store NH3 during the low-temperature / cold start stage of the engine (exhaust temperature below 250 °C), and gradually desorb NH3 during the normal exhaust temperature stage of the engine (exhaust temperature above 250 °C).

[0040] The sensors included in the sensor unit are: an exhaust temperature sensor 3 provided on the first pipe section 14, exhaust pressure sensors respectively provided on the second pipe section 1 and the third pipe section 20, and nitrogen oxide sensors and ammonia sensors respectively provided on the third pipe section 20 and the fifth pipe section 2.

[0041] All sensors in the passive ammonia adsorber 4, the diesel particulate filter 7, the selective catalytic reducer 10, the ammonia slip trap 23, the control butterfly valve A, the control butterfly valve B, the electric heater, the on-vehicle hydrogen production device and the sensor unit are connected to the ECU of the engine.

[0042] In the present invention, the structure of the diesel particulate filter 7 is as Figure 3 shown. The diesel particulate filter 7 includes a housing 24. A DPF filter element 25 is provided inside the housing. The DPF filter element 25 is open-ended on one side at the front end of the housing 24, and filter element working surfaces are arranged at positions except the open end; a spark plug 27 penetrating through the housing 24 and the filter element working surface is provided on the side wall of the diesel particulate filter 7; the low-pressure hydrogen nozzle 6 is arranged on the side wall of the housing 24 on the side of the open end, and the low-pressure hydrogen nozzle 6 penetrates through the housing 24 and the filter element working surface; flanges are respectively provided at the front and rear ends of the housing 24 for installing the diesel particulate filter 7 in the exhaust pipe between the passive ammonia adsorber 4 and the selective catalytic reducer 10.

[0043] In the present invention, the electric heater is used to increase the temperature of the ammonia provided by the engine ammonia fuel tank and heat the on-vehicle hydrogen production device. Its temperature is controlled by the ECU control module to ensure the smooth combustion of NH3 in the engine and improve its conversion rate in the on-vehicle hydrogen production device at the same time;

[0044] The SCR carrier and coating 21 are provided in the selective catalytic reducer 10.

[0045] The system for online ammonia hydrogen production and storage for DPF regeneration proposed by the present invention can achieve DPF regeneration.

[0046] When the engine is running, the exhaust gas of the engine passes through the on-vehicle hydrogen production device, and part of the exhaust heat is supplied to the ammonia cracker. The ammonia cracker mainly uses the exhaust heat to catalytically crack the ammonia provided by the ammonia fuel tank into hydrogen and nitrogen, and the generated H2 is introduced into the hydrogen storage device for storage. The reaction formula is: 2NH3 → N2 + 3H2 (there is also a very small amount of un-cracked ammonia in the system). At the same time, the ECU of the engine judges whether the DPF needs to be regenerated according to the signal of the exhaust pressure sensor. If regeneration is required, the control butterfly valve B is opened, and the low-pressure hydrogen nozzle 6 is controlled to inject H2 into the diesel particulate filter for regeneration.

[0047] When the engine is running, the ECU of the engine controls the ammonia storage tank to inject ammonia into the third pipe section between the diesel particulate filter and the selective catalytic reducer according to the NOx and NH3 concentration signals collected by the nitrogen oxide sensor and the ammonia sensor, mixes with the tail gas, and then realizes reduction in the selective catalytic reducer. The reaction equations are: 4NH3 + 4N2O + O2 → 6N2 + 6H2O; 4NH3 + 2NO + O2 → 3N2 + 6H2O; 8NH3 + 6NO2 → 7N2 + 12H2O.

[0048] The ammonia slip trap 23 is provided with an ASC carrier and coating 22. The coating is a noble metal coating with a molecular-level pore diameter, which can adsorb NH3 with a molecular-level pore diameter and catalytically oxidize and decompose it into N2 and H2O under the action of a certain temperature.

[0049] The process of realizing DPF regeneration by the present invention is as follows:

[0050] 1) When the engine is powered on, the ECU controls the electric heater to start. The ammonia in the ammonia storage tank enters the pressure stabilizing tank after being heated by the electric heater, and then is divided into two parts. One part enters the intake passage, and the other part enters the ammonia cracker.

[0051] 2) During the operation of the engine, the tail gas will pass through the on-vehicle hydrogen production device, so that part of the waste heat is transferred to the ammonia cracker, further promoting its catalytic cracking of ammonia to generate hydrogen, and the hydrogen is introduced into the hydrogen storage tank for storage. The reaction formula is: 2NH3 → N2 + 3H2 (there is also a very small amount of un-cracked ammonia in the system).

[0052] 3) Part of the hydrogen generated by the ammonia cracker is injected into the intake passage through a low-pressure hydrogen nozzle to mix with ammonia to form an ammonia-hydrogen mixture, which is supplied to the engine for combustion. The other part of the hydrogen enters the particulate trap through the control butterfly valve B and the low-pressure hydrogen nozzle 6 as the fuel required for regeneration to achieve DPF regeneration.

[0053] 4) The first exhaust pressure sensor 5 and the second exhaust pressure sensor 8 arranged at the front end and the end of the diesel particulate trap 7 in the exhaust passage respectively feedback the collected pressure signals to the ECU. The ECU determines the DPF regeneration timing according to the difference in exhaust pressure between the front and the rear. Since the carbon loading filtered in the DPF carrier is the main factor causing the back pressure difference, and the back pressure difference is a function of the DPF carbon loading, which increases as the DPF carbon loading increases. Therefore, the correlation function between the two is calibrated in advance at different loads and speeds and the database is input into the ECU. When the back pressure difference reaches a certain threshold, the ECU determines that the DPF carbon loading reaches saturation and needs to start the regeneration program, controls the low-pressure hydrogen nozzle 6 to open and the spark plug 16 to fire to achieve DPF regeneration. It should be noted that the above threshold is calibrated for different engine models, and the method for determining this threshold belongs to the common knowledge in the industry and will not be elaborated here.

[0054] 5) The first nitrogen oxide sensor 18 and the first ammonia sensor 19 collect the concentrations of NOx and NH3 in the exhaust gas after passing through the diesel particulate trap 7 and feedback the signals to the ECU. The ECU adjusts the heating temperature of the electric heater according to the concentrations of the two to promote the combustion of NH3 in the engine;

[0055] When the engine is in the cold start / low exhaust temperature stage (exhaust temperature < 250 °C), when the exhaust gas passes through the PDF carrier 12 in the diesel particulate trap 7, most of the NH3 is adsorbed. At this time, the NOx content is low, and only a small amount of the remaining NH3 is needed to be reduced in the selective catalytic reducer 10;

[0056] When the engine exhaust temperature is in the normal stage (exhaust temperature > 250 °C), as the exhaust temperature rises, the PAA carrier 15 in the passive ammonia adsorber gradually desorbs NH3. At this time, the engine is in a normal working state and the combustion becomes more complete. Therefore, there is a large amount of NOx in the exhaust gas. At this time, the flow rate of the low-pressure ammonia nozzle is controlled by the ECU, that is, the ECU judges the concentrations of NOx and NH3 in the exhaust gas according to the signals collected by the first nitrogen oxide sensor 18 and the first ammonia sensor 19, and adjusts the opening of the control butterfly valve A and the pulse width of the low-pressure ammonia nozzle 9 to control the amount of ammonia entering the selective catalytic reducer 10, so that the NOx is reduced in the selective catalytic reducer 10; Further, the unreacted NH3 in the selective catalytic reducer 10 enters the subsequent ammonia oxidation trap 23 and is catalytically oxidized to N2 and H2O therein.

[0057] In summary, the present invention is a DPF regeneration system applicable to the post-treatment of emissions of an ammonia-diesel dual-fuel engine. It eliminates the fuel injector assembly and only installs the igniter assembly. Hydrogen is produced online by a small reformer and injected into the burner through a simple gas valve. This not only solves the problem of high usage cost and design cost of the regeneration equipment in the prior art, but also optimizes the post-treatment system for the emissions of the ammonia-diesel dual-fuel engine, achieving a more compact structure and lower emissions.

[0058] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many variations without departing from the purpose of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An ammonia on-line hydrogen production and storage system for DPF regeneration, characterized in that, The system includes an ammonia fuel tank, an on-vehicle hydrogen production device and its sensor unit; the ammonia fuel tank is provided with an ammonia storage tank, an electric heater and a pressure stabilizing tank. The on-vehicle hydrogen production device includes an ammonia cracker; the engine is provided with an intake passage and an exhaust passage; On the exhaust passage, successively connected along the gas flow discharge direction from the connection end with the engine through pipe segments are a passive ammonia adsorber (4), a diesel particulate filter (7), a selective catalytic reducer (10) and an ammonia slip catcher (23); the connecting pipe segment between the passive ammonia adsorber (4) and the engine is the first pipe segment (14), the connecting pipe segment between the diesel particulate filter (7) and the passive ammonia adsorber (4) is the second pipe segment (1), the connecting pipe segment between the selective catalytic reducer (10) and the diesel particulate filter (7) is the third pipe segment (20), the connecting pipe segment between the ammonia slip catcher (23) and the selective catalytic reducer (10) is the fourth pipe segment (11), and the discharge port of the ammonia slip catcher (23) is connected to the atmosphere through a fifth pipe segment; The ammonia storage tank is provided with two exhaust ports, one exhaust port is connected to the electric heater, and the other exhaust port is successively connected to the third pipe segment (20) through a control butterfly valve A and a low-pressure ammonia nozzle (9); The ammonia fuel tank is provided with two gas outlets, and the two gas outlets are respectively connected to the intake port of the ammonia cracker and the intake passage; the exhaust port of the ammonia cracker is connected to a hydrogen storage device through an exhaust pipe, the hydrogen storage device is provided with two gas outlets, one gas outlet is connected to the intake passage, and the intake passage is connected to the external air; the other gas outlet is successively connected to the diesel particulate filter (7) through a control butterfly valve B and a low-pressure hydrogen nozzle (6); The sensors included in the sensor unit are: an exhaust gas temperature sensor (3) provided on the first pipe segment (14), exhaust gas pressure sensors respectively provided on the second pipe segment (1) and the third pipe segment (20), and nitrogen oxide sensors and ammonia sensors respectively provided on the third pipe segment (20) and the fifth pipe segment (2); The passive ammonia adsorber (4), the diesel particulate filter (7), the selective catalytic reducer (10), the ammonia slip catcher (23), the control butterfly valve A, the control butterfly valve B, the electric heater, the on-vehicle hydrogen production device and all the sensors in the sensor unit are connected to the ECU of the engine.

2. The system for DPF regeneration using on-line ammonia hydrogen production and storage according to claim 1, wherein, The two gas outlets provided on the ammonia fuel tank are respectively a first gas outlet and a second gas outlet. The first gas outlet is connected to the intake air rail to provide ammonia for fuel; the second gas outlet is connected to the ammonia cracker, and the ammonia cracker catalytically cracks part of the ammonia to produce hydrogen.

3. The system for ammonia on-line hydrogen production storage for DPF regeneration according to claim 1, characterized in that, The passive ammonia adsorber (4) is provided with a PAA carrier and a coating (15). The passive ammonia adsorber (4) adopts an ion exchange process to adsorb and store NH3 during the low-temperature / cold start stage of the engine and gradually desorb NH3 during the normal exhaust gas temperature stage of the engine.

4. The system for DPF regeneration using on-line ammonia hydrogen production and storage according to claim 1, characterized in that, The diesel particulate filter (7) includes a housing (24). A DPF filter element (25) is provided inside the housing. The DPF filter element (25) is open at one side of the front end of the housing (24), and filter element working surfaces are arranged at positions except the open end. A spark plug (27) penetrating through the housing (24) and the filter element working surfaces is provided on the side wall of the diesel particulate filter (7). The low-pressure hydrogen nozzle (6) is arranged on the side wall of the housing (24) at the side of the open end. The low-pressure hydrogen nozzle (6) penetrates through the housing (24) and the filter element working surfaces. Flanges are respectively provided at the front and rear ends of the housing (24) for installing the diesel particulate filter (7) in the exhaust pipeline between the passive ammonia adsorber (4) and the selective catalytic reducer (10).

5. The system for ammonia on-line hydrogen production storage for DPF regeneration according to claim 1, characterized in that, An SCR carrier and coating (21) are provided in the selective catalytic reducer (10).

6. The system for DPF regeneration using on-line ammonia hydrogen production and storage according to claim 1, characterized in that, An ASC carrier and coating (22) are provided in the ammonia slip trap (23). The coating is a noble metal coating with a molecular-level pore diameter, which adsorbs NH3 and catalytically oxidizes and decomposes it into N2 and H2O.

7. A method for on-line ammonia hydrogen production storage for DPF regeneration, characterized in that, Using the ammonia on-line hydrogen production storage system for DPF regeneration as described in any one of claims 1 to 6; When the engine is running, the exhaust gas of the engine passes through the on-vehicle hydrogen production device. Part of the exhaust heat is supplied to the ammonia cracker. The H2 generated in the ammonia cracker is introduced into the hydrogen storage device for storage. At the same time, the ECU of the engine judges whether the DPF needs to be regenerated according to the exhaust pressure sensor signal. If regeneration is required, the control butterfly valve B is opened, and the low-pressure hydrogen nozzle (6) is controlled to inject H2 into the diesel particulate filter to achieve regeneration; When the engine is running, the ECU of the engine controls the ammonia storage tank to inject ammonia into the third pipe section between the diesel particulate filter and the selective catalytic reducer according to the NOx and NH3 concentration signals collected by the nitrogen oxide sensor and the ammonia sensor, to mix with the tail gas, and then reduction is achieved in the selective catalytic reducer. The reaction equations are: 4NH3 + 4N2O + O2 → 6N2 + 6H2O; 4NH3 + 2NO + O2 → 3N2 + 6H2O; 8NH3 + 6NO2 → 7N2 + 12H2O.

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