Integrated hydrogen ammonia engine tail gas nitrogen pollutant thermocatalytic conversion device

Abstract

The invention discloses an integrated hydrogen-ammonia engine tail gas nitrogen pollutant thermocatalytic conversion device, and relates to the technical field of hydrogen-ammonia engine tail gas treatment, the integrated hydrogen-ammonia engine tail gas nitrogen pollutant thermocatalytic conversion device comprises a shell and an electric control unit; the shell comprises a component detection device, an electric heating type mixing plate, a urea solution spraying device, a temperature monitoring device, a purification device and an electric control unit; the purification device comprises a two-section type structure, namely a first-section SCR reaction area and a second-section ASC-NDC integration area; the electric control unit is electrically connected with each electric component; according to the invention, sequencing optimization and integrated design of hydrogen-ammonia engine parts are realized, and the requirements of triple-effect collaborative purification of nitrogen pollutants, high efficiency, energy conservation and stable operation under all working conditions are met.

Description

Technical Field

[0001] This invention relates to the field of hydrogen ammonia engine exhaust technology, specifically an integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen ammonia engine exhaust. Background Technology

[0002] As a core piece of equipment in the clean energy transition, the hydrogen-ammonia engine boasts significant advantages such as a wide range of fuel sources and near-zero carbon emissions, making its application prospects increasingly broad in transportation, industrial power, and other fields. However, the exhaust emission characteristics of hydrogen-ammonia engines differ fundamentally from those of traditional combustion engines; their exhaust contains not only NO... x Nitrogen oxides, NH3 ammonia escape and other major pollutants also produce N2O nitrous oxide, a strong greenhouse gas. The greenhouse effect of N2O is more than 300 times that of CO2. Moreover, N2O has a long residence time in the atmosphere and is difficult to decompose naturally. It has become a key environmental bottleneck restricting the commercialization of hydrogen-ammonia engines, making "three-effect synergistic purification of nitrogen pollutants" the core requirement of hydrogen-ammonia engine after-treatment technology. Current exhaust aftertreatment technologies for hydrogen-ammonia engines still follow or modify traditional engine aftertreatment approaches, failing to develop targeted designs for the emission characteristics and all-condition adaptability requirements of hydrogen-ammonia engines. This results in several core shortcomings, as detailed below: The low level of integration and unreasonable component arrangement result in poor mixing and purification effects. Existing technologies mostly adopt a "single-function device series" design mode, setting up SCR device, ASC device, and NDC device to treat different pollutants separately, resulting in a large system space occupation, high exhaust back pressure, and reduced engine power performance; Insufficient adaptability to cold start conditions leads to a sharp drop in low-temperature purification efficiency; the initial exhaust gas temperature is extremely low during the cold start phase of the hydrogen-ammonia engine, and the catalyst activity is almost lost under low-temperature conditions, resulting in NO... x The removal rate and N2O decomposition rate decreased significantly, while the NH3 escape rate increased significantly. The existing equipment lacks a targeted cold start rapid heating design, the power distribution of the heating components is unreasonable, the heating rate is slow, and it is difficult to raise the exhaust gas temperature to the suitable working range of the catalyst in a short time, which cannot meet the purification requirements of the cold start stage. The control strategy is crude and lacks precise closed-loop adaptation capability. Existing devices mostly monitor exhaust gas components and temperature through single-point sampling, and the adjustment of urea solution injection volume and heating power relies on preset operating condition calibration, failing to form a closed-loop logic of "detection-feedback-adjustment". In summary, existing hydrogen-ammonia engine exhaust aftertreatment technologies have significant shortcomings in integrated design, component sorting optimization, cold start adaptation, and control precision. They cannot meet the actual needs of synergistic purification of nitrogen pollutants, high efficiency and energy saving, and stable operation under all working conditions. There is an urgent need to develop a targeted integrated and precise exhaust treatment device to solve the above-mentioned technical problems. Summary of the Invention

[0003] The purpose of this invention is to provide a technical solution for an integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust, so as to solve the problems raised in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: An integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust includes a housing and an electronic control unit. The front end of the inner shell is sequentially equipped with a component detection device, an electrically heated mixing plate, a urea solution injection device, a temperature monitoring device, and a purification device for step-by-step treatment of the exhaust gas along the exhaust gas flow direction. The exhaust gas treatment process consists of “component detection → heating and flow equalization → precise injection → temperature monitoring → staged catalysis”, which completes the closed-loop control of the entire process and achieves synergistic treatment of nitrogen pollutants through three effects. The electrically heated mixing plate includes a heating component and a mixing plate, and the heating component and the mixing plate are a seamlessly welded integral structure. The mixing plate is provided with guide holes for guiding the exhaust gas. The spray direction of the urea solution injection device is consistent with the exhaust gas flow direction; All electrical components are electrically connected to the electrical control unit.

[0005] Furthermore, the component detection device is used to collect raw exhaust gas component data in real time and feed it back to the electronic control unit; The electrically heated mixing plate is an integrated structure that combines heating and mixing functions, used to increase the temperature of the exhaust gas and make the gas mix evenly. The urea solution spraying device is controlled by the electronic control unit to start and stop spraying urea solution. The temperature monitoring device is used to monitor the temperature data of the exhaust gas after heating and mixing with urea solution, and feeds it back to the electronic control unit; The purification device includes a two-section structure, namely, the first section is the SCR reaction zone and the second section is the ASC-NDC integration zone; The purification device adopts a two-section structure and is integrated into a single housing. The electronic control unit controls the start / stop of the urea solution injection device and the amount of urea solution injected based on the exhaust gas raw component data detection results of the component detection device; and controls the start / stop of the electrically heated mixing plate and the power adjustment based on the exhaust gas temperature data detection results of the temperature monitoring device. Furthermore, the component detection device has a built-in NO... x Sensors and NH3 sensors; It should be noted that the sensor assembly of the present invention includes NO. X Sensors, NH3 sensors and temperature sensors, NO X The sensor and NH3 sensor are integrated into the component detection device and installed at the front end of the electrically heated mixing plate. The sensor probe extends vertically into the exhaust gas flow channel for real-time detection of NO in the exhaust gas. X The NH3 concentration is fed back to the electronic control unit to provide accurate data for adjusting the urea injection volume, ensuring that the ammonia-nitrogen ratio is adapted to the three-way catalytic conversion requirements; the temperature sensor is installed between the urea solution injection device and the carrier area to accurately detect the temperature of the exhaust gas after heating and mixing, providing a basis for adjusting the electric heating power and ensuring that each catalyst is in the optimal temperature window. Furthermore, the electrically heated mixing plate includes a heating component and a mixing plate, and the heating component and the mixing plate are a seamlessly welded integral structure; The heating component is an integrated structure with adjustable power in different levels, and is powered by an independent circuit for multi-level temperature control. The mixing plate is a flow guiding structure; The flow guiding structure includes a plurality of flow guiding holes evenly distributed on the mixing plate; The guide hole is a single-hole structure, and its channel is flared along the exhaust gas flow direction. The mixing plate features a flow-guiding structure composed of several uniformly distributed flow-guiding holes. Each hole is a single-hole structure with an flared opening along the exhaust gas flow direction, designed to reduce exhaust gas velocity and break up uneven flow fields. This structure reduces the exhaust gas velocity from an initial 25-35 m / s to 10-18 m / s, with exhaust gas velocity fluctuations ≤ ±5% and cross-sectional velocity uniformity ≥ 90%. Simultaneously, it promotes full contact between the exhaust gas and the urea solution, preventing the formation of localized concentration zones and ensuring that the mixed gas covers the entire cross-section of the subsequent carrier region at a uniform velocity, allowing NO to... X It reacts fully with NH3 in the SCR reaction zone, improving the synergistic purification efficiency; Furthermore, the SCR reaction zone uses a Cu-SSZ-13 molecular sieve catalyst, which is coated onto a porous support structure through an impregnation process; wherein, the silicon-to-aluminum ratio of the Cu-SSZ-13 molecular sieve catalyst is 15-20. This catalyst has an extremely wide temperature window of 200-550℃, which can efficiently utilize the NH3 in the exhaust gas and the NH3 generated by urea hydrolysis to reduce NO. x The core reaction equation is 4NO + 4NH3 + O2 = 4N2 + 6H2O; Both the ASC-NDC integration region and the SCR reaction region are porous carriers, and the ASC-NDC integration region includes an ASC reaction region in the front sub-region and an NDC reaction region in the back sub-region. The SCR reaction zone is a single porous carrier, and the ASC-NDC integration zone is a porous carrier. The ASC reaction zone and the NDC reaction zone are an integrated structure of the ASC-NDC integrated zone, which is divided into sections along the exhaust gas flow direction. Furthermore, the ASC reaction zone uses a Pt / Pd noble metal oxidation catalyst combined with an additive, which is applied to a porous support structure by an impregnation process; wherein the additive is a CeO2 or ZrO2-based composite oxide. The impregnation process is either vacuum impregnation or atmospheric pressure impregnation; the vacuum degree of vacuum impregnation is 0.08-0.1MPa and the impregnation time is 2-4h; the atmospheric pressure impregnation time is 4-6h; after impregnation, it is dried at 120℃±10℃ and calcined at 550℃±20℃. The NDC reaction zone employs an Fe-ZSM-5 molecular sieve catalyst, which is coated onto a porous support structure via an impregnation process. The Fe-ZSM-5 molecular sieve catalyst has an iron loading of 2-5 wt%. It should be noted that the ASC-NDC integrated reaction zone adopts a design of axially partitioned catalyst coating on the same porous carrier, eliminating the need for additional independent carriers or nested structures, thus achieving overall integration: the front sub-zone of the carrier, close to the SCR reaction zone and accounting for 50% of its length, is coated with Pt / Pd noble metal oxidation catalyst and combined with CeO2 or ZrO2-based composite oxide promoters to form the ASC reaction zone, with a temperature window of 250~400℃ and high activity, used to oxidize and remove NH3 escaping from the SCR reaction zone, avoiding secondary pollution. The core reaction equation is 4NH3+3O2=2N2+6H2O; the rear sub-zone of the carrier is coated with Fe-ZSM-5 molecular sieve catalyst to form the NDC reaction zone. This catalyst has an iron loading of 2-5wt%, excellent high-temperature activity, and is used to decompose N2O in the tail gas. The core reaction equation is 2N2O=2N2+O2. The NH3 oxidation process in the ASC reaction zone is a strongly exothermic reaction. The heat generated is conducted axially to the NDC reaction zone in the subsequent sub-zone through the carrier itself, so that the temperature of the NDC reaction zone is stably maintained above 400°C, which perfectly matches its high-temperature working requirements. No additional independent heating equipment is required, realizing the efficient coupling and utilization of heat energy. At the same time, the carrier structure is kept as a whole, reducing airflow resistance and ensuring the continuity of nitrogen pollutant purification. It should also be noted that the porous carrier structures of the SCR reaction zone and the ASC-NDC integrated reaction zone are made of porous ceramic or cordierite to ensure that the structural strength and thermal conductivity are compatible. The SCR reaction zone and the ASC-NDC integrated reaction zone are connected by a breathable partition layer. This breathable partition layer is made of porous ceramic with a porosity of 30%-40%, which not only ensures smooth flow of exhaust gas, but also prevents catalyst particles from migrating between the two zones, while also assisting in the conduction of some heat, further optimizing the thermal management effect. Furthermore, when the electronic control unit receives the raw component data of the exhaust gas collected by the component detection device and analyzes the NH3 and NO in the exhaust gas... x The concentration ratio k was analyzed; When k≤1, the electronic control unit sends a start injection command to the urea solution injection device and adjusts the urea solution injection volume of the urea solution injection device to ensure that NH3 and NO are mixed. x The concentration ratio is between (1, 1.2). When k≥1.2, the electronic control unit sends a stop spraying command to the urea solution spraying device; It should be noted that the electronic control unit is the core of the device control system, electrically connected to the urea solution injector and the electrically heated mixing plate, respectively, and executes precise control logic. When NO... X The sensor and the NH3 sensor detected NH3:NO in the exhaust gas. X When the concentration is ≥1.2, the electronic control unit controls the urea solution injector to stop injecting, and the NO requirement can be met by relying on the NH3 in the exhaust gas. X Restoration requirements; when NH3:NO X When ≤1, control the injector to start and adjust the injection volume so that NH3 and NO... X The concentration ratio was maintained at (1, 1.2) to increase NO. X Conversion rate, ensuring the effectiveness of the three-way catalytic conversion; It should be noted that (1, 1.2) is the interval where the endpoint values ​​cannot be obtained; Furthermore, the logic for the electronic control unit to control the exhaust gas temperature of the temperature monitoring device is as follows: When the temperature monitoring device detects that the initial temperature of the exhaust gas is less than 200°C, the electronic control unit first activates the high-power setting of the heating component in the electric heating mixing plate to maintain the exhaust gas heating rate at or above 30°C / min. When the temperature monitoring device detects that the exhaust gas temperature is greater than or equal to 200°C and less than or equal to 550°C, the power setting of the heating component is adjusted to the low power setting, and the temperature is maintained by relying on the exhaust waste heat of the hydrogen-ammonia engine and the heat released by the ASC reaction. When the temperature monitoring device detects that the exhaust gas temperature is greater than 550°C, the heating component is turned off. The heating component has two power settings: high and low. The specific setting can be flexibly adjusted according to the exhaust gas temperature requirements. The electrically heated mixing plate is the core integrated component, adopting an integrated design for heating and mixing functions. It consists of a heating element with adjustable power settings and a mixing plate that are seamlessly connected or integrally formed, eliminating the need for separate heating and mixing devices and significantly improving system integration. The heating element is powered by an independent circuit and can flexibly adjust the power setting according to the exhaust gas temperature requirements to achieve graded temperature control. For cold start conditions, the heating element is equipped with a rapid heating mode, with a heating rate of ≥30℃ / min when running at the highest power setting. It can raise the exhaust gas temperature from the initial cold start temperature <200℃ to the suitable operating temperature lower limit of 200℃ for the SCR catalyst within 5 minutes, ensuring catalytic activity during the cold start phase. The catalyst operating temperature window of the SCR reaction zone is 200-550℃, the catalyst operating temperature window of the ASC reaction zone is 250-400℃, and the catalyst operating temperature window of the NDC reaction zone is 400-550℃. Specifically, the temperature control logic of the electronic control unit includes a cold start-specific adaptation strategy: when the initial exhaust gas temperature is <200℃ (cold start condition), the high-power setting of the electrically heated mixing plate is activated first to rapidly heat up at a rate of ≥30℃ / min; when the temperature sensor detects that the exhaust gas temperature is lower than the suitable temperature window of 200℃ for the SCR reaction zone, the high-power setting is maintained for heating; when the exhaust gas temperature reaches 200-550℃, the heating power setting is reduced, relying on the exhaust waste heat of the engine and the heat released by the ASC reaction to maintain temperature stability; if the temperature exceeds 550℃, heating is stopped to prevent the catalyst from deactivating due to high-temperature sintering, avoid energy waste, and ensure temperature adaptation of each catalyst, thereby improving the economy of three-way catalytic conversion.

[0006] Furthermore, the distance between the component detection device and the electrically heated mixing plate along the exhaust gas flow direction is set to S1; The distance between the electrically heated mixing plate and the urea solution injection device along the exhaust gas flow direction is set to S2; The distance between the urea solution injection device and the temperature monitoring device along the exhaust gas flow direction is set to S3; where S1, S2 and S3 are distance constants. The component detection device, electrically heated mixing plate, urea solution injection device, and temperature monitoring device are arranged in sequence with precise spacing to meet functional requirements: the distance between the component detection device and the electrically heated mixing plate can be selected as 20-30mm to ensure the collection of undisturbed raw exhaust gas component data; the distance between the electrically heated mixing plate and the urea solution injection device can be selected as 30-40mm to provide sufficient mixing space for the exhaust gas after urea injection and equalization; the distance between the urea solution injection device and the temperature monitoring device can be selected as 15-20mm to ensure the detection of the actual mixed gas temperature after urea hydrolysis. This arrangement breaks away from the unreasonable traditional "inject first, then heat" design, significantly improving mixing and purification efficiency. Furthermore, the SCR reaction zone and the temperature monitoring device are connected by a first breathable partition layer; The SCR reaction zone and the ASC-NDC integration zone are connected by a second breathable separator layer. The first breathable separator layer has the same structure as the second breathable separator layer.

[0007] Compared with the prior art, the beneficial effects of the present invention are: Component sequencing optimization and integrated design: Through a scientific sequencing and integrated design of "component detection → heating and flow equalization → urea injection → temperature monitoring," heating, mixing, and three-way catalytic converter functions are integrated into a single device. The ASC-NDC uses the same porous carrier, saving installation space and reducing engine back pressure compared to traditional multi-device series designs, while simultaneously addressing NOx emissions. x The purification challenges of NH3 and N2O are addressed by achieving synergistic three-effect treatment of nitrogen pollutants in a single device, simplifying the system structure. Cold start adaptability and catalytic life optimization: The targeted rapid heating mode and temperature control strategy avoid the performance degradation of the catalyst due to low temperature deactivation or high temperature sintering, extend the service life, and ensure long-term stability under all operating conditions. Strong closed-loop control and adaptability under all operating conditions: Through closed-loop control of sensor components and electronic control unit, it can adapt to different operating conditions such as engine cold start, low load, and high load in real time, and accurately adjust the urea injection quantity and electric heating power to ensure that the device can maintain the best three-way catalytic conversion effect under all operating conditions, providing technical support for the commercial promotion of hydrogen ammonia engine. Attached Figure Description

[0008] Figure 1 This is a half-sectional schematic diagram of the overall structure of an integrated thermocatalytic conversion device for nitrogen pollutants in the exhaust gas of a hydrogen-ammonia engine according to the present invention. Figure 2 This is a schematic diagram of the electrically heated mixing plate of an integrated hydrogen-ammonia engine exhaust nitrogen pollutant thermocatalytic conversion device according to the present invention. Figure 3This is a flowchart of the control logic program for an integrated thermocatalytic conversion device for nitrogen pollutants in the exhaust gas of a hydrogen-ammonia engine, according to the present invention.

[0009] Reference numerals: 1. Inlet flange; 2. Exhaust gas inlet pipe; 3. Component detection device; 4. Electric heating mixing plate; 5. Urea solution injection device; 6. Temperature monitoring device; 7. First permeable partition layer; 8. SCR denitrification reaction zone; 9. Second permeable partition layer; 10. ASC-NDC integrated reaction zone; 11. Outer shell; 12. Purified exhaust gas outlet pipe; 13. Outlet flange. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] Example 1: As Figure 1 As shown, the present invention provides a technical solution: The present invention discloses an integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas. The device comprises, in sequence along the exhaust gas flow direction, an inlet flange 1, an exhaust gas inlet pipe 2, a component detection device 3, an electrically heated mixing plate 4, a urea solution injection device 5, a temperature monitoring device 6, a first permeable separation layer 7, an SCR denitrification reaction zone 8, a second permeable separation layer 9, an ASC-NDC integrated reaction zone 10, an outer shell 11, a purified exhaust gas outlet pipe 12, and an outlet flange 13. All components are assembled inside the outer shell and are equipped with an electronic control unit. All electrical components are electrically connected to the electronic control unit. The overall structure is compact and the assembly logic is clear. The inlet flange 1 and the exhaust inlet pipe 2 are integrally formed from stainless steel. The inner diameter of the exhaust inlet pipe 2 is compatible with the engine exhaust pipe. It is sealed to the engine exhaust system via the sealing groove of the inlet flange 1, ensuring no exhaust leakage. The component detection device 3 is fixed downstream of the exhaust inlet pipe 2 with circumferential bolts and contains an internal NO... x The sensor and NH3 sensor have their probes inserted vertically into the exhaust gas flow channel, maintaining a 20-30mm gap with the downstream electrically heated mixing plate 4. The collected raw exhaust gas component data are transmitted to the electronic control unit via a shielded cable to ensure that the data transmission is not interfered with.

[0012] Example 2, as Figure 2 As shown, the present invention provides another technical solution: The electrically heated mixing plate 4 is an integrated structure where the heating component and the mixing plate are seamlessly welded together. It is made of high-temperature resistant stainless steel and is fixed inside the outer shell 11 by a circumferential bracket. The heating component is an integrated structure with adjustable power levels and is connected to the electronic control unit through an independent circuit, enabling multi-level power adjustment. The mixing plate has evenly distributed guide holes, which are single-hole structures with flared openings along the exhaust gas flow direction, effectively breaking up uneven flow fields. The nozzle of the urea solution injection device 5 is oriented in the same direction as the gas flow, with the nozzle outlet facing the downstream area of ​​the mixing plate guide hole. Combined with a urea pump and pressure sensor, it ensures effective urea droplet atomization. The device is fixed inside the housing 11 by a bracket, maintaining a 15-20mm distance from the temperature monitoring device 6. Its start / stop and injection volume are dynamically controlled by the electronic control unit based on component detection data. The temperature monitoring device 6 uses a thermocouple sensor; the probe extends into the flow channel to detect the temperature of the heated and mixed exhaust gas. The data is fed back to the electronic control unit in real time, providing precise data for adjusting the electric heating power. In this embodiment, both permeable separation layers are made of porous cordierite ceramic material with a porosity of 30%-40%. The first permeable separation layer 7 is assembled between the temperature monitoring device 6 and the SCR denitrification reaction zone 8 and is fixed by a slot to isolate impurities that may be carried in the airflow. The second permeable separation layer 9 is assembled between the SCR denitrification reaction zone 8 and the ASC-NDC integrated reaction zone 10, with its edge attached to the inner wall of the outer shell 11. This not only prevents the catalyst particles in the two areas from migrating to each other, but also helps to conduct heat and optimize the thermal management effect. The SCR denitrification reaction zone 8 uses a porous support made of porous ceramic or cordierite. The surface is coated with Cu-SSZ-13 molecular sieve catalyst through vacuum impregnation or atmospheric pressure impregnation. Vacuum impregnation uses a vacuum degree of 0.08-0.1 MPa for 2-4 hours, while atmospheric pressure impregnation lasts 4-6 hours. After impregnation, the catalyst is dried at 120℃±10℃ and calcined at 550℃±20℃ to ensure strong catalyst adhesion and maintain high activity. Both ends of the support are sealed to the inner wall of the outer shell 11 with high-temperature resistant gaskets to ensure uniform airflow through the catalytic zone. The ASC-NDC integrated reaction zone 10 uses a porous carrier of the same specifications as the SCR denitrification reaction zone 8. It is divided into front and rear sub-zones along the axial direction without physical separation: the front sub-zone is coated with a Pt / Pd noble metal oxidation catalyst and supplemented with CeO2 or ZrO2-based composite oxide additives, forming the ASC reaction zone; the rear sub-zone is coated with an Fe-ZSM-5 molecular sieve catalyst with an iron loading of 2-5 wt%, forming the NDC reaction zone. Both catalysts are prepared using the same process as the SCR denitrification reaction zone 8. The carrier is fixed inside the outer shell 11 by positioning pins and separated from the SCR denitrification reaction zone 8 by a second permeable partition layer 9. The purified exhaust gas outlet pipe 12 and the outlet flange 13 are integrally formed of stainless steel. The inner diameter of the purified exhaust gas outlet pipe 12 is compatible with the ASC-NDC integrated reaction zone 10. The inner wall is treated with a corrosion-resistant coating. It is sealed and connected to the subsequent exhaust pipe through the outlet flange 13 to ensure that the purified exhaust gas is discharged without leakage.

[0013] Example 3, as Figure 3 As shown, the present invention provides another technical solution: The electronic control unit (ECU) is the core of the device control, integrating multiple control modules. It is installed in an independent protective box and fixed to the outside of the outer casing 11. It is compatible with the vehicle power supply and supports bus communication and data storage and debugging functions. Its control logic flow is as follows: After the engine starts, the ECU simultaneously activates the component detection device 3 and the temperature monitoring device 6 to collect initial exhaust gas component and temperature data. If the initial exhaust gas temperature is detected to be <200℃ (cold start condition), the ECU sends a command to activate the high-power setting of the electrically heated mixing plate to rapidly heat up at a rate of ≥30℃ / min. When the temperature monitoring device 6 detects that the exhaust gas temperature reaches 200℃-550℃, the ECU adjusts the heating power setting to low power according to the real-time temperature, relying on the exhaust waste heat of the engine and the heat released by the ASC reaction to maintain temperature stability. When the temperature monitoring device 6 detects that the exhaust gas temperature is >550℃, heating stops. Component detection device 3 transmits NO in real time x The electronic control unit analyzes and processes the NH3 concentration data: when NH3:NO is detected in the exhaust gas... x When ≥1.2, the urea solution injection device 5 is stopped; when NH3:NO x When ≤1, the urea solution injection device 5 is activated and the injection volume is adjusted to allow NH3 and NO to react. x The concentration ratio was maintained at (1, 1.2). After component detection, temperature equalization, urea mixing, and two-stage permeable separation layer guidance, the exhaust gas flowed sequentially through the SCR denitrification reaction zone 8 and the ASC-NDC integrated reaction zone 10 to complete the NO removal process. x The three-way catalytic conversion of reduction, NH3 oxidation and N2O decomposition is finally discharged through the purified exhaust gas outlet pipe 12 and the outlet flange 13, achieving synergistic and efficient purification of the three types of nitrogen pollutants.

[0014] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An integrated thermocatalytic conversion device for nitrogen pollutants in the exhaust gas of a hydrogen-ammonia engine, comprising a housing and an electronic control unit, characterized in that: The front end of the inner shell is sequentially equipped with a component detection device, an electrically heated mixing plate, a urea solution injection device, a temperature monitoring device, and a purification device for step-by-step treatment of the exhaust gas along the exhaust gas flow direction. The electrically heated mixing plate includes a heating component and a mixing plate, and the heating component and the mixing plate are a seamlessly welded integral structure. The mixing plate is provided with guide holes for guiding the exhaust gas. The spray direction of the urea solution injection device is consistent with the exhaust gas flow direction; The purification device includes a two-section structure, namely a first SCR reaction zone and a second ASC-NDC integrated zone; The SCR reaction zone is coated with a first molecular sieve catalyst by an impregnation process. The ASC-NDC integration region includes the ASC reaction region in the front sub-region and the NDC reaction region in the back sub-region; The ASC reaction zone is coated with an oxidation catalyst through an impregnation process; The NDC reaction zone is coated with a second molecular sieve catalyst by an impregnation process. All electrical components are electrically connected to the electrical control unit.

2. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The flow guide holes are evenly distributed on the mixing plate; The guide hole is a single-hole structure, and its channel is flared along the exhaust gas flow direction.

3. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The heating component is an integrated structure with adjustable power levels, and is powered by an independent circuit for multi-level temperature control; the heating component is electrically connected to the electronic control unit.

4. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The component detection device is used to collect raw component data of exhaust gas in real time and feed it back to the electronic control unit; The electrically heated mixing plate is an integrated structure that combines heating and mixing functions, used to increase the temperature of the exhaust gas and make the gas mix evenly. The urea solution spraying device is controlled by the electronic control unit to start and stop spraying urea solution. The temperature monitoring device is used to monitor the temperature data of the exhaust gas after heating and mixing with urea solution, and feeds it back to the electronic control unit; The electronic control unit controls the start / stop of the urea solution injection device and the amount of urea solution injected based on the detection results of the raw component data of the exhaust gas from the component detection device. The start / stop and power adjustment of the electrically heated mixing plate are controlled based on the exhaust gas temperature data monitoring results of the temperature monitoring device.

5. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The SCR reaction zone uses Cu-SSZ-13 molecular sieve catalyst as the first molecular sieve catalyst, which is coated onto the porous support structure by an impregnation process. Both the ASC-NDC integration region and the SCR reaction region are porous carriers; The ASC reaction zone and the NDC reaction zone are an integral structure of the ASC-NDC integrated zone, which is divided into sections along the exhaust gas flow direction.

6. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 5, characterized in that: The ASC reaction zone uses a Pt / Pd noble metal oxidation catalyst as the oxidation catalyst and combines it with an auxiliary agent, which is applied to a porous support structure by an impregnation process. The NDC reaction zone uses Fe-ZSM-5 molecular sieve catalyst as the second molecular sieve catalyst, which is applied to the porous support structure by an impregnation process.

7. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The control logic of the electronic control unit for controlling the urea solution injection device is as follows: When the electronic control unit receives the raw component data of the exhaust gas collected by the component detection device and analyzes the NH3 and NO in the exhaust gas... x The concentration ratio k was analyzed; When k≤1, the electronic control unit sends a start injection command to the urea solution injection device and adjusts the urea solution injection volume of the urea solution injection device to ensure that NH3 and NO are mixed. x The concentration ratio is between (1, 1.2). When k≥1.2, the electronic control unit sends a stop spraying command to the urea solution spraying device.

8. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The logic for controlling the exhaust gas temperature by the electronic control unit using the temperature monitoring device is as follows: When the temperature monitoring device detects that the initial temperature of the exhaust gas is less than 200°C, the electronic control unit first activates the high-power setting of the heating component in the electric heating mixing plate to maintain the exhaust gas heating rate at or above 30°C / min. When the temperature monitoring device detects that the exhaust gas temperature is greater than or equal to 200°C and less than or equal to 550°C, the power setting of the heating component is adjusted to the low power setting, and the temperature is maintained by relying on the exhaust waste heat of the hydrogen-ammonia engine and the heat released by the ASC reaction. When the temperature monitoring device detects that the exhaust gas temperature is greater than 550°C, the heating component is turned off.

9. The integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 1, characterized in that: The distance between the component detection device and the electrically heated mixing plate along the exhaust gas flow direction is set to S1; The distance between the electrically heated mixing plate and the urea solution injection device along the exhaust gas flow direction is set to S2; The distance between the urea solution injection device and the temperature monitoring device along the exhaust gas flow direction is set to S3; where S1, S2 and S3 are distance constants.

10. An integrated thermocatalytic conversion device for nitrogen pollutants in hydrogen-ammonia engine exhaust gas according to claim 5, characterized in that: The SCR reaction zone is connected to the temperature monitoring device via a first breathable partition layer. The SCR reaction zone and the ASC-NDC integration zone are connected by a second breathable separator layer. The first breathable separator layer has the same structure as the second breathable separator layer.

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