A multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions

Abstract

The present invention discloses a multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions, which includes an ammonia fuel tank and an on-vehicle hydrogen production device. The ammonia fuel tank is provided with an electric heater and a pressure stabilizing tank, and is connected to an ammonia cracker and an intake passage; the outlet of the ammonia cracker is respectively connected to an exhaust pipe and an intake pipe; the exhaust passage is successively a PAA, a TWC and an integrated post-processor along the gas flow direction; part of the hydrogen generated by the ammonia cracker enters the TWC to react with NO; in the integrated post-processor, a first carrier and a second carrier are successively arranged along the gas flow direction, and are respectively provided with a molecular sieve coating for treating N2O and a noble metal catalyst coating for catalytically oxidizing NH3 into N2 and H2O. In view of the characteristics of large NOx emissions and low exhaust gas temperature of ammonia engines, the present invention adopts ammonia cracking technology and catalytic reduction technology, and adsorbs and catalyzes in segments through a multi-effect coupling method to achieve ultra-low NOx and unburned NH3 emissions of ammonia-hydrogen engines.

Description

Technical Field

[0001] This invention patent relates to the technical field of the automotive industry, and particularly to an ammonia-hydrogen engine pollutant emission treatment system. Background Art

[0002] Compared with battery technology, engines have significant advantages such as compact structure, high thermal efficiency, and convenient operation and maintenance. However, engines using traditional fuels produce a large amount of carbon emissions, and there is an urgent need to develop new zero-carbon or carbon-neutral fuels to achieve zero carbon emissions from engines.

[0003] Ammonia, as a zero-carbon fuel, can be obtained from fossil fuels, biomass, or other renewable resources. Compared with hydrogen, ammonia is safer and more reliable, has a higher volumetric energy density, and a lower unit energy storage cost. However, ammonia fuel has a high ignition energy, slow combustion, and low efficiency. At the same time, vehicle engines operate under various working conditions, such as cold start and transient conditions, and the pollutant emissions of ammonia fuel are relatively serious at this time.

[0004] The emissions generated by the combustion of ammonia fuel contain relatively more NO and N 2 O, and there is also a lot of unburned NH 3 . The exhaust gas temperature generated by the combustion of ammonia fuel is relatively low, and the temperature needs to be increased compared to the original SCR catalytic reduction. At the same time, there are significant differences in the working characteristics, temperature range, and reductant selectivity of traditional SCR. Therefore, it is necessary to develop a dedicated post-treatment system for ammonia (or ammonia-based) fuel internal combustion engines for NO, N 2 O and NH 3 emissions.

[0005] Therefore, the present invention proposes an integrated emission post-treatment system for multi-effect coupling of ammonia-hydrogen engines to achieve ultra-low NOx and unburned NH 3 emissions. Summary of the Invention

[0006] In view of the above-mentioned prior art, the present invention provides a multi-effect coupling catalytic conversion system for ammonia-hydrogen engine emissions post-treatment. This system aims at the characteristics of difficult ignition of ammonia fuel, large NOx emissions, and low exhaust gas temperature. It uses ammonia cracking technology and catalytic reduction technology, and through multi-effect coupling, it adsorbs and catalyzes in segments to achieve ultra-low NOx and unburned NH 3 emissions of ammonia-hydrogen engines.

[0007] To solve the above technical problems, a multi-effect coupled catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions proposed by the present invention includes an ammonia fuel tank and an on-vehicle hydrogen production device. The ammonia fuel tank is provided with an electric heater and a pressure stabilizing tank; the on-vehicle hydrogen production device includes an ammonia cracker; the outlet of the ammonia fuel tank is connected to the inlet of the ammonia cracker; the engine is provided with an intake passage and an exhaust passage; the outlet of the ammonia fuel tank is respectively connected to the intake port of the ammonia cracker and the intake passage, the exhaust port of the ammonia cracker is connected to the intake passage through an exhaust pipe, and the intake passage is connected to external air; on the exhaust passage, a passive ammonia adsorber, a three-way catalytic converter, and an integrated post-processor are sequentially connected through pipe segments along the gas flow discharge direction from the connection end with the engine; the connecting pipe segment between the passive ammonia adsorber and the engine is the first pipe segment, the connecting pipe segment between the three-way catalytic converter and the passive ammonia adsorber is the second pipe segment, the connecting pipe segment between the integrated post-processor and the three-way catalytic converter is the third pipe segment, and the discharge port of the integrated post-processor is connected to the atmosphere through a fourth pipe segment; a bypass is connected between the exhaust pipe of the ammonia cracker and the second pipe segment, a control butterfly valve is provided on the bypass, and a low-pressure hydrogen nozzle is provided at one end of the bypass located on the second pipe segment; the passive ammonia adsorber is filled with a passive ammonia adsorber carrier and a catalyst; the passive ammonia adsorber adopts an ion exchange process to adsorb and store NH 3 during the low-temperature / cold start stage of the engine and gradually desorb NH 3 during the normal exhaust temperature stage of the engine; the three-way catalytic converter is filled with a three-way catalytic converter carrier and a catalyst; a part of the hydrogen generated by the ammonia cracker is injected into the intake passage to be mixed with the ammonia provided by the ammonia fuel tank to form an ammonia-hydrogen mixture for combustion by the engine, and the other part enters the three-way catalytic converter through the control butterfly valve and the low-pressure hydrogen nozzle to react with NO; the first carrier and the second carrier are sequentially arranged along the gas flow direction in the integrated post-processor, and the first carrier and the second carrier are provided with internally staggered internal channels. The internal channels of the first carrier are provided with a molecular sieve coating for treating N 2 O, and the internal channels of the second carrier are provided with a noble metal catalyst coating for oxidizing ammonia catalytically into nitrogen and water; nitrogen oxide sensors and ammonia sensors connected to the ECU of the engine are respectively provided on the first pipe segment and the fourth pipe segment; the electric heater, the on-vehicle hydrogen production device, the control butterfly valve, the passive ammonia adsorber, and the integrated post-processor are all connected to the ECU of the engine.

[0008] Furthermore, in the multi-effect coupled catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions of the present invention:

[0009] The ECU includes a PID control module. The PID control module controls the temperature of the exhaust gas before the three-way catalytic converter through the electric heater according to the exhaust gas temperature fed back by the engine temperature sensor, so that the exhaust gas reaches the light-off temperature of the three-way catalytic converter.

[0010] Part of the hydrogen generated in the ammonia cracker, under the action of the catalyst in the three-way catalytic converter, converts NO in the tail gas into N 2 O and NH 3 , and the reaction formula is: NO + H 2 →N 2 O + NH 3 .

[0011] Gaskets are provided between the housing of the integrated aftertreatment device and the first carrier and between the housing of the integrated aftertreatment device and the second carrier.

[0012] After the tail gas is treated by the three-way catalytic converter, it enters the integrated aftertreatment device. The reaction formula when passing through the internal channels of the first carrier is: 2N 2 O → 2N 2 + O 2 , and the reaction formula when passing through the internal channels of the second carrier is: 4NH 3 + 3O 2 → 2N 2 + 6H 2 O.

[0013] The ammonia fuel tank is provided with 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 generate hydrogen.

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

[0015] The present invention omits the complex and expensive SCR system in the traditional engine aftertreatment system, adopts the form of TWC + integrated aftertreatment device, and adsorbs and catalyzes NOx and NH in the tail gas in sections. 3 .

[0016] The present invention combines ammonia cracking technology and electric heating catalytic reduction technology. Through the passive ammonia adsorber (PAA), NH is adsorbed in the cold start / low exhaust temperature stage. 3 , and NH is desorbed in the normal exhaust temperature stage. 3 , and part of the H 2 generated in the ammonia cracker is introduced into the three-way catalytic converter to react with NO in the tail gas to generate N 2 O and NH 3 .

[0017] Since ammonia-hydrogen fuel engines mostly adopt stoichiometric combustion mode, the oxygen concentration in the tail gas under normal operating conditions is basically zero, and the catalytic oxidation of ammonia in the ammonia trap requires oxygen. Therefore, the present invention designs an integrated post-treatment device. 2 O catalytic decomposition to N 2 and O 2 After that, use N 2 O produced by catalytic decomposition of 2 , for NH 3 In the present invention, the integrated post-processor does not need to be fed with external air, which greatly simplifies the structure of the post-processing system and further reduces the risk of ammonia escape. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a control schematic diagram of the multi-effect coupled catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions of the present invention;

[0019] Figure 2 It is a schematic diagram of the exhaust passage and post-processing system structure of the present invention;

[0020] Figure 3 It is a schematic diagram of the structure of the present invention;

[0021] Figure 4 yes Figure 3 Schematic cross-section of the integrated post-processor shown.

[0022] In the figure:

[0023] 1- Control butterfly valve 2- First NOx sensor

[0024] 3-First ammonia sensor 4-Passive ammonia adsorber

[0025] 5-Low-pressure hydrogen nozzle 6-Three-way catalytic converter

[0026] 7- Third pipe section 8- Integrated post-processor

[0027] 9- Second nitrogen oxide sensor 10- Second ammonia sensor

[0028] 11- First pipe section 12- Passive ammonia adsorber carrier and catalyst

[0029] 13- Second pipe section 14- Three-way catalytic converter carrier and catalyst

[0030] 15-first carrier 16-second carrier

[0031] 17-Padding DETAILED DESCRIPTION

[0032] In the description of the present invention, it should be noted that the ordinal articles such as "first", "second", "third", "fourth", etc. are only for the convenience of describing the present invention and simplifying the description, and do not reflect the importance of the referred devices or parts, and should not be construed as a limitation to the technical solution of the present invention.

[0033] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] 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.

[0035] A multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions proposed by the present invention, as Figure 1 shown, the system includes an ammonia fuel tank and an on-vehicle hydrogen production device. The ammonia fuel tank is provided with an electric heater and a pressure stabilizing tank; the on-vehicle hydrogen production device includes an ammonia cracker; the outlet of the ammonia fuel tank is connected to the inlet of the ammonia cracker. The engine is provided with an intake passage and an exhaust passage; the outlet of the ammonia fuel tank is respectively connected to the intake port of the ammonia cracker and the intake passage. Specifically, the ammonia fuel tank is provided with a first outlet and a second outlet. The first outlet is connected to the intake air rail for providing ammonia for fuel; the second outlet is connected to the ammonia cracker, and the ammonia cracker catalytically cracks part of the ammonia to produce hydrogen. The exhaust port of the ammonia cracker is connected to the intake passage through exhaust pipe A, and the intake passage is connected to the external air.

[0036] As Figure 1 and Figure 2 shown, on the exhaust passage, in the direction of the gas flow from the connection end with the engine, there are sequentially connected a passive ammonia adsorber (PAA) 4, a three-way catalytic converter (TWC) 6, and an integrated post-processor 8 through pipe segments. The connecting pipe segment between the passive ammonia adsorber 4 and the engine is the first pipe segment 11, the connecting pipe segment between the three-way catalytic converter 6 and the passive ammonia adsorber 4 is the second pipe segment 13, the connecting pipe segment between the integrated post-processor 8 and the three-way catalytic converter 6 is the third pipe segment 7, and the discharge port of the integrated post-processor 8 is connected to the atmosphere through the fourth pipe segment. A bypass is connected between the exhaust pipe A of the ammonia cracker and the second pipe segment 13. A control butterfly valve 1 is provided on the bypass, and a low-pressure hydrogen nozzle 5 is provided at one end of the bypass located at the second pipe segment 13.

[0037] The passive ammonia adsorber 4 is filled with a passive ammonia adsorber carrier and a catalyst 12; the passive ammonia adsorber 4 adopts an ion exchange process to adsorb and store NH 3 during the low-temperature / cold start stage of the engine (exhaust gas temperature is lower than 250 °C), and allows NH 3 to gradually desorb during the normal exhaust gas temperature stage of the engine (exhaust gas temperature is higher than 250 °C).

[0038] The three-way catalytic converter 6 is filled with a three-way catalytic converter carrier and a catalyst 13; part of the hydrogen generated by the ammonia cracker is injected into the intake passage to be mixed with the ammonia provided by the ammonia fuel tank to form an ammonia-hydrogen mixture for the engine to burn, and the other part enters the three-way catalytic converter 6 through the control butterfly valve 1 and the low-pressure hydrogen nozzle 5 to react with NO; part of the hydrogen generated in the ammonia cracker, under the action of the catalyst in the three-way catalytic converter 6, converts NO in the exhaust gas into N 2 O and NH 3 , and the reaction formula is: NO + H 2 → N 2 O + NH 3 for subsequent centralized treatment.

[0039] As Figure 3 and Figure 4 shown, a first carrier 15 and a second carrier 16 are arranged in sequence along the gas flow direction in the integrated post-processor 8, and gaskets 17 are provided between the housing of the integrated post-processor 8 and the first carrier 15 and between the housing of the integrated post-processor 8 and the second carrier 16. The first carrier 15 and the second carrier 16 are provided with internally staggered internal channels. The internal channels of the first carrier 15 are provided with a molecular sieve coating for treating N 2 O, and the internal channels of the second carrier 16 are provided with a noble metal catalyst coating for catalytically oxidizing ammonia into nitrogen and water; after the exhaust gas is treated by the three-way catalytic converter 6, it enters the integrated post-processor 8, and the reaction formula when passing through the internal channels of the first carrier 15 is: 2N 2 O → 2N 2 + O 2 , and the reaction formula when passing through the internal channels of the second carrier 16 is: 4NH 3 + 3O 2 → 2N 2 + 6H 2 O.

[0040] As Figure 2 shown, the first pipe section 11 is provided with a first nitrogen oxide sensor 2 and a first ammonia sensor 3 connected to the ECU of the engine; the fourth pipe section is provided with a second nitrogen oxide sensor 9 and a second ammonia sensor 10 connected to the ECU of the engine. AsFigure 1 As shown, the electric heater, in-vehicle hydrogen production device, control butterfly valve 1, passive ammonia adsorber 4, and integrated post-processor 8 are all connected to the ECU of the engine. The ECU includes a PID control module. In the present invention, the PID control module is based on the exhaust temperature feedback by the engine temperature sensor. In the present invention, the electric heater is used to raise the temperature of the engine exhaust (cold start exhaust) and the ammonia provided by the ammonia fuel tank, and the exhaust before the three-way catalytic converter 6 is temperature-controlled by the electric heater to reach the light-off temperature of the three-way catalytic converter.

[0041] In the present invention, the catalyst in the ammonia cracker can be the ruthenium-on-magnesia catalyst disclosed in the patent document CN108160072A, such as Figure 1 As shown, the exhaust port of the ammonia cracker is divided into two outlets through a tee provided on the connecting pipe A. One of the outlets is connected to the intake passage to supply hydrogen to the engine, and the other outlet is connected to the front exhaust pipe section of the three-way catalytic converter 6 (i.e., Figure 2 the third pipe section 7 shown in) to supply a small amount of hydrogen to the tail gas to achieve conversion in the three-way catalytic converter. At the same time, the hydrogen flow rate is controlled by the control butterfly valve 4 according to the signal of the first nitrogen oxide sensor 2 received by the ECU.

[0042] In the present invention, the coating of the inner pores of the first carrier 12 of the integrated post-processor is a molecular sieve coating with a molecular screening function, which can adsorb NO at a molecular-level pore size and catalyze the decomposition of NO under the action of a certain temperature. In the present invention, the molecular sieve coating can adopt ZSM-5 (molecular sieve containing organic amine cations). Because it has many unique properties in chemical composition, crystal structure, and physical and chemical properties, it has excellent catalytic efficiency in many catalytic reactions. ZSM-5 molecular sieve has good adsorption properties for nitrogen oxides and can also be used as a catalyst to achieve good adsorption and decomposition effects on NO. At present, the more common ones that can adsorb NO 2 O 2 and, under the action of a certain temperature, catalyze the decomposition of NO. In the present invention, the molecular sieve coating can adopt ZSM-5 (molecular sieve containing organic amine cations). Since it has many unique properties in chemical composition, crystal structure, and physical and chemical properties, it has excellent catalytic efficiency in many catalytic reactions. ZSM-5 molecular sieve has good adsorption properties for nitrogen oxides and can also be used as a catalyst to achieve good adsorption and decomposition effects on NO. At present, the more common ones that can adsorb NO 2 O 2Catalytic materials for adsorption and decomposition of O include Fe-ZSM-5 based on iron, Cu-ZSM-5 based on copper, Co-ZSM-5 based on cobalt, etc. Considering that Fe-ZSM-5 has better stability and temperature resistance, and the gases processed by the after-treatment system of automobiles are often in a high-temperature state, which is likely to cause the instability of ZSM-5. In the present invention, Fe-ZSM-5 is used as the coating material in the first carrier 15 of the integrated after-treatment device. Noble metals are used as the catalyst coating in the internal channels of the second carrier 16 of the integrated after-treatment device. In the present invention, it is particularly emphasized that the internal channels of the second carrier 16 of the integrated after-treatment device are staggered with the internal channels of the first carrier 15 to increase the contact time and contact surface of the exhaust gas with the coating in the carrier, and ensure NH in the exhaust gas. 3 Undergo sufficient catalytic oxidation.

[0043] The working process of the multi-effect coupling catalytic conversion system for the post-treatment of ammonia-hydrogen engine emissions in the present invention is as follows:

[0044] 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 heater, and then divides into two parts. One part enters the intake passage, and the other part enters the on-vehicle hydrogen production device (ammonia cracker).

[0045] During the operation of the engine, the exhaust gas passes through the on-vehicle hydrogen production device, and a part of the waste heat is transferred to the ammonia cracker, further promoting its catalytic cracking of ammonia to produce hydrogen.

[0046] Part of the hydrogen generated by the ammonia cracker is injected into the intake port to be mixed with ammonia to form an ammonia-hydrogen mixture gas and supplied to the engine for combustion. The other part is controlled by the butterfly valve and nozzle to enter the three-way catalytic converter to react with NO to generate N 2 O and NH 3 .

[0047] The engine exhaust gas first passes through the first pipe section 11 of the connection section between the engine and the PAA. At the same time, the first nitrogen oxide sensor 2 and the first ammonia sensor 4 respectively collect the NOx and NH3 contents in the exhaust gas and feedback the signals to the ECU. The ECU then adjusts the H entering the second pipe section 13 by controlling the butterfly valve 1 and the low-pressure hydrogen nozzle 5. 2 Flow rate. When the exhaust gas passes through the passive ammonia adsorber carrier 12 during the cold start / low exhaust temperature stage (exhaust temperature < 250 °C), a large amount of NH 3 is adsorbed. At this time, the NOx content is low, and only a small amount of H 2It can be restored; when the exhaust temperature is in the normal stage (exhaust temperature > 250 °C), as the exhaust temperature rises, the passive ammonia adsorption carrier 12 can gradually desorb NH3. At this time, since the engine is in a normal working state and the combustion becomes more complete, there is a large amount of NOx in the exhaust gas. At this time, the exhaust gas is mixed with the hydrogen gas ejected from the low-pressure hydrogen nozzle 5 in the second pipe section 13 and then reacts in the three-way catalytic converter carrier 14 to generate N 2 O and NH 3 , and then enters the first carrier 15 of the integrated post-processor through the third pipe section 7 to catalytically decompose N 2 O into N 2 and O 2 . In the second carrier 16 of the integrated post-processor, the O 2 generated after passing through the first carrier 15 is used to catalytically oxidize NH 3 into N 2 and H 2 O.

[0048] In summary, the integrated emission post-treatment system for the multi-effect coupling of the ammonia-hydrogen fuel engine involved in the present invention uses PAA, TWC and the integrated post-processor to perform segmented catalysis and integrated treatment on NOx and NH 3 , optimizes the emission post-treatment system of the traditional engine, and realizes a more compact structure and lower emissions.

[0049] 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 and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make corresponding changes without departing from the purpose of the present invention. For example, in the cold start state of the engine in alpine regions, due to extremely deteriorated combustion and relatively low exhaust temperature, it can be considered to configure an additional electric heating device for the three-way catalytic converter TWC to enable it to start burning as soon as possible under alpine conditions. The above-changed technical solutions fall within the protection scope of the present invention.

Claims

1. A multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions, characterized in that, it includes an ammonia fuel tank and an on-vehicle hydrogen production device. The ammonia fuel tank is provided with an electric heater and a pressure stabilizing tank; the on-vehicle hydrogen production device includes an ammonia cracker; the outlet of the ammonia fuel tank is connected to the inlet of the ammonia cracker; the engine is provided with an intake passage and an exhaust passage; the outlet of the ammonia fuel tank is respectively connected to the intake port of the ammonia cracker and the intake passage, the exhaust port of the ammonia cracker is connected to the intake passage through exhaust pipe (A), and the intake passage is connected to the external air; 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 three-way catalytic converter (6) and an integrated post-processor (8); the connecting pipe segment between the passive ammonia adsorber (4) and the engine is the first pipe segment (11), the connecting pipe segment between the three-way catalytic converter (6) and the passive ammonia adsorber (4) is the second pipe segment (13), the connecting pipe segment between the integrated post-processor (8) and the three-way catalytic converter (6) is the third pipe segment (7), and the discharge port of the integrated post-processor (8) is connected to the atmosphere through the fourth pipe segment; a bypass is connected between the exhaust pipe (A) of the ammonia cracker and the second pipe segment (13), a control butterfly valve (1) is provided on the bypass, and a low-pressure hydrogen nozzle (5) is provided at one end of the bypass located on the second pipe segment (13); The passive ammonia adsorber (4) is filled with a passive ammonia adsorber carrier and a catalyst (12); the passive ammonia adsorber (4) adopts an ion exchange process to adsorb and store NH 3 during the low-temperature / cold start stage of the engine, and to gradually desorb NH 3 during the normal exhaust gas temperature stage of the engine; the three-way catalytic converter (6) is filled with a three-way catalytic converter carrier and a catalyst (13); part of the hydrogen generated by the ammonia cracker is injected into the intake passage to be mixed with the ammonia provided by the ammonia fuel tank to form an ammonia-hydrogen mixture and provided to the engine for combustion, and the other part enters the three-way catalytic converter (6) through the control butterfly valve (1) and the low-pressure hydrogen nozzle (5) to react with NO; The first carrier (15) and the second carrier (16) arranged in sequence along the air flow direction inside the integrated post-processor (8), internal channels are arranged on the first carrier (15) and the second carrier (16) and are staggered from each other, and the internal channel of the first carrier (15) is provided with a molecular sieve coating for treating NO 2 ; the internal channel of the second carrier (16) is provided with a noble metal catalyst coating for catalytically oxidizing ammonia into nitrogen and water; the first pipe segment (11) and the fourth pipe segment are respectively provided with a nitrogen oxide sensor and an ammonia sensor connected to the ECU of the engine; the electric heater, the on-vehicle hydrogen production device, the control butterfly valve (1), the passive ammonia adsorber (4) and the integrated post-processor (8) are all connected to the ECU of the engine.

2. The multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions according to claim 1, characterized in that, the ECU includes a PID control module, and the PID control module controls the temperature of the exhaust gas before the three-way catalytic converter (6) through the electric heater according to the exhaust gas temperature fed back by the engine temperature sensor to make it reach the light-off temperature of the three-way catalytic converter.

3. The multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions according to claim 1, characterized in that, Part of the hydrogen produced in the ammonia cracker is used to convert NO in the tail gas into N under the action of the catalyst in the three-way catalytic converter (6). 2 O and NH 3 , the reaction formula is: NO+H 2 →N 2 O+NH 3 .

4. The multi-effect coupling catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions according to claim 1, characterized in that, gaskets (17) are provided between the housing of the integrated post-processor (8) and the first carrier (15) and between the housing of the integrated post-processor (8) and the second carrier (16).

5. The multi-effect coupled catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions according to claim 1, characterized in that, After the tail gas is treated by the three-way catalytic converter (6), it enters the integrated post-processor (8). The reaction formula when passing through the internal channels of the first carrier (15) is: 2N 2 O → 2N 2 + O 2 , and the reaction formula when passing through the internal channels of the second carrier (16) is: 4NH 3 + 3O 2 → 2N 2 + 6H 2 O.

6. The multi-effect coupled catalytic conversion system for post-treatment of ammonia-hydrogen engine emissions according to claim 1, characterized in that, the ammonia fuel tank is provided with a first gas outlet and a second gas outlet. The first gas outlet is connected to the intake air rail for providing ammonia for fuel. The second gas outlet is connected to the ammonia cracker, and the ammonia cracker catalytically cracks part of the ammonia to generate hydrogen.

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