A low carbon emission engine aftertreatment system and control method

Abstract

The application provides a low-carbon emission engine aftertreatment system and control method, relates to the low-carbon emission engine emission control technical field, and increases a rapid heating branch on a main exhaust passage; the rapid heating branch is configured to: under the condition that the exhaust temperature of the low-carbon emission engine is insufficient, the mixed gas of ambient air and engine exhaust is compressed and heated to obtain a high-temperature gas flow in a preset temperature range, low-carbon fuel is injected into the high-temperature gas flow, the hydrogen-rich gas generated by the cracking reaction is connected to the main exhaust passage, and then, exothermic reaction occurs, so that the normal working temperature of the aftertreatment catalyst in the main exhaust passage is provided, and the aftertreatment of the engine exhaust is carried out. Under the typical working conditions of cold start, low-load operation, urban congestion cycle and the like, the application realizes rapid temperature rise in seconds, greatly improves the aftertreatment efficiency, effectively inhibits ammonia leakage and NOx emission, and takes into account the efficiency and reliability of operation.

Description

Technical Field

[0001] This invention relates to the field of emission control technology for low-carbon emission engines, and specifically to an after-treatment system and control method for a low-carbon emission engine. Background Technology

[0002] With the continuous upgrading and development of requirements for low-carbon environmental protection and engine emission control, emission control has gradually expanded from traditional steady-state operating condition assessment to strict constraints on emissions under all operating conditions and throughout the entire life cycle. It has also strengthened the supervision of emissions during actual driving and transient operating conditions such as cold start and acceleration.

[0003] Studies have shown that under typical operating conditions such as cold starts, low-load operation, and urban congestion cycles, where exhaust temperatures are insufficient, the exhaust temperature is typically below the effective operating window of the catalytic converter because the engine and aftertreatment system have not yet warmed up. This results in pollutants such as NOx, unburned HC, and ammonia being difficult to convert effectively and being emitted directly, accounting for up to 50% or more of the total emissions in the entire test cycle. To reduce cold-start emissions, the industry commonly employs technologies such as electric heating and engine thermal management optimization. However, existing solutions generally suffer from slow response times, limited heating efficiency, and high energy consumption, making it difficult to heat the aftertreatment system to an efficient operating state in a short time. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an aftertreatment system and control method for a low-carbon emission engine. Under typical operating conditions such as cold start, low-load operation, and urban congestion cycles where exhaust temperature is insufficient, it achieves rapid temperature rise within seconds, significantly improving aftertreatment efficiency while effectively suppressing ammonia leakage and NOx emissions, thus balancing high efficiency and reliability.

[0005] According to some embodiments, the present invention adopts the following technical solution: An aftertreatment system for a low-carbon emission engine, comprising adding a rapid heating branch to the main exhaust passage; The rapid heating branch is configured to: compress and heat the mixture of ambient air and engine exhaust gas under the condition that the exhaust temperature of the low-carbon emission engine is insufficient, to obtain a high-temperature airflow within a preset temperature range, inject low-carbon fuel into the high-temperature airflow, and after the hydrogen-rich gas produced by the cracking reaction enters the main exhaust channel, an exothermic reaction occurs, providing the aftertreatment catalyst in the main exhaust channel with normal operating temperature for aftertreatment of engine exhaust gas.

[0006] According to some embodiments, the present invention adopts the following technical solution: A method for controlling the aftertreatment system of a low-carbon emission engine, comprising: Preheating control stage: The fuel injection pyrolysis unit remains off, relying solely on the electric centrifugal compression heating module and the thermal conversion chamber for physical heating and heat conversion; Cracking activation stage: When the outlet temperature of the thermal conversion chamber meets the preset conditions, the fuel injection cracking device is turned on to inject and crack low-carbon fuel, generate hydrogen-rich gas, and connect it to the main exhaust channel to provide normal operating temperature for the aftertreatment catalyst. Post-treatment temperature maintenance stage: When the inlet temperature of the selective catalytic reduction unit meets the preset conditions, the speed of the electric centrifugal compressor heating module is gradually reduced, the temperature is maintained by the exothermic reaction of the oxidation catalyst and the particulate filter, and the low-carbon fuel injection quantity is finely adjusted by closed-loop control. Normal emission control phase: When the inlet temperature of the selective catalytic reduction device reaches the ignition temperature, the rapid heating branch is shut off, and the system switches back to the main exhaust passage, with engine exhaust aftertreatment only performed through the main exhaust passage.

[0007] According to some embodiments, the present invention adopts the following technical solution: A computer program product includes a computer program that, when executed by a processor, implements the aftertreatment system of a low-carbon emission engine.

[0008] According to some embodiments, the present invention adopts the following technical solution: A non-transitory computer-readable storage medium is provided for storing computer instructions, which, when executed by a processor, implement the after-treatment system of a low-carbon emission engine.

[0009] According to some embodiments, the present invention adopts the following technical solution: An electronic device includes a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to implement the after-treatment system of a low-carbon emission engine.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention optimizes energy utilization pathways and thermal management mechanisms, and by triggering a cascade exothermic reaction, achieves rapid temperature rise within seconds after cold start, providing a stable heat source for the aftertreatment system in a very short time. It significantly shortens the overall heating process of the aftertreatment system, reducing the time from compressor inlet to selective catalytic reduction unit outlet to normal operating temperature by approximately 60%-80% compared to traditional electric heating solutions, greatly reducing cumulative emissions during cold start, especially for NOx emission control. It also achieves fundamental improvements in ammonia leakage control, bringing ammonia leakage close to zero, overcoming a long-standing technical bottleneck in ammonia fuel engines and low exhaust temperature conditions. Regarding system reliability, this invention eliminates high-temperature electric heating elements, instead employing a more robust rotating mechanical structure and a mature and reliable injection valve solution, enabling stable operation under harsh conditions such as vibration and thermal shock, significantly improving overall durability and engineering applicability. Attached Figure Description

[0011] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0012] Figure 1 This is a structural diagram of the aftertreatment system of a low-carbon emission engine in Example 1.

[0013] Figure 2 This is a structural diagram of the heat conversion cavity in Example 1.

[0014] Figure 3 This is a structural diagram of the ammonia injection pyrolysis device in Example 1.

[0015] Figure 4 This is a comparison chart of the heat release time in Example 1.

[0016] Figure 5 This is the overall control strategy diagram for Example 2. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Example 1 One embodiment of the present invention provides an aftertreatment system for a low-carbon emission engine, which adds a rapid heating branch to the main exhaust passage; The rapid heating branch is configured to: compress and heat the mixture of ambient air and engine exhaust gas under the condition that the exhaust temperature of the low-carbon emission engine is insufficient, to obtain a high-temperature airflow within a preset temperature range, inject low-carbon fuel into the high-temperature airflow, and after the hydrogen-rich gas produced by the cracking reaction enters the main exhaust channel, an exothermic reaction occurs, providing the aftertreatment catalyst in the main exhaust channel with normal operating temperature for aftertreatment of engine exhaust gas.

[0021] As one embodiment, the aftertreatment system of a low-carbon emission engine of the present invention is applied to a compression ignition engine that uses ammonia fuel (or other low-carbon fuel) as the main energy source. The engine displacement is 6 to 13L, and it is mainly used in application scenarios such as urban buses, construction machinery or heavy vehicles that have frequent cold starts and low-load operation conditions.

[0022] like Figure 1 As shown, the aftertreatment system includes, in sequence along the exhaust flow direction of the engine: an electric centrifugal compression heating module, a thermal conversion chamber, a fuel injection cracking device, an oxidation catalyst, a particulate filter, a selective catalytic reduction device, and an ammonia escape catalyst. A fresh air / exhaust gas mixing device is set at the front end of the system to mix ambient air with engine exhaust. All actuators and sensors are electrically connected to the electronic control unit (ECU).

[0023] The main exhaust passage, consisting of an oxidation catalyst, a particulate filter, a selective catalytic reduction device, and an ammonia escape catalyst, is the structure of existing aftertreatment systems. This embodiment adds a rapid heating branch to the existing main exhaust passage structure, consisting of an electric centrifugal compression heating module, a thermal conversion chamber, and a fuel injection pyrolysis device. Engine exhaust can be switched between the main exhaust passage and the rapid heating branch via a switching valve. Under typical operating conditions such as cold start, low-load operation, and urban congestion cycles where exhaust temperature is insufficient, exhaust or ambient air is guided into the electric centrifugal compression heating module. Under normal emission conditions, exhaust directly enters the conventional aftertreatment passage. The following detailed explanation of each module is based on the cold start condition as an example: 1. Electric centrifugal compression heating module: Composed of a high-speed motor, a centrifugal compressor impeller, and an electronically controlled power module, its function is to quickly draw in ambient air or part of the engine exhaust during the cold start phase, compress it, and significantly increase the gas temperature and flow rate, providing a heat source and airflow driving force independent of the engine operating conditions. It can still achieve high-response heating when the engine is at low speed and low load, creating the necessary temperature and flow conditions for subsequent thermal conversion reactions.

[0024] Furthermore, unlike traditional centrifugal compressors which require high efficiency / high pressure ratio and stable surge margin, the electric centrifugal compression heating module aims to provide rapid heating and flow during the cold start phase. It adopts a low-pressure-ratio, high-flow-rate impeller-volute matching, weakens static pressure recovery, strengthens low-resistance stable operation, and is adapted and optimized for the high-temperature, condensation, and pollution conditions of the intake exhaust.

[0025] In this embodiment, the electric centrifugal compression heating module includes a high-speed permanent magnet synchronous motor, an integrated centrifugal compressor impeller and matching volute structure, and an electronic control power module. The high-speed motor has a maximum speed of 60,000–90,000 rpm and a rated power of 3–8 kW. Unlike traditional centrifugal compressors used for boosting, the electric centrifugal compression heating module in this embodiment adopts a low-pressure ratio, high-flow design, with a design pressure ratio of 1.05–1.5, focusing on enhancing stable operation and transient response under low-pressure ratio conditions. The gap between the impeller and the volute, as well as the diffuser structure, are optimized to reduce flow resistance and expand the stable operating range, allowing for rapid acceleration without surge during cold starts. During the initial cold start phase, when the engine exhaust temperature is below 150°C, the ECU controls a switching valve to allow ambient air into the module; when the engine exhaust temperature rises slightly but is still insufficient to heat the aftertreatment system, the ECU allows some exhaust gas to mix into the module to improve heating efficiency. During operation, the module does not optimize for compression efficiency. Instead, it generates significant heat through gas compression and motor losses, providing a stable high-temperature gas source for subsequent thermal conversion.

[0026] 2. Heat conversion chamber: Located downstream of the electric centrifugal compression heating module, its function is to further integrate heat, suppress fluctuations, and perform secondary heating on the high-temperature gas from the compression heating module, stabilize the gas temperature, reduce transient fluctuations, and provide a high-temperature environment for the ammonia cracking reaction.

[0027] Furthermore, the heat conversion cavity employs oscillation / acoustic dissipation to convert kinetic energy into thermal energy, such as... Figure 2As shown, its main components include a pulsating jet pipe, a short-tube resonator, a flow control and bypass valve, an adjustable bypass pipeline, a hot air outlet, a micro-perforated plate, and a porous sound-absorbing structure. One or more short-tube-cavity resonators are arranged on the sidewall of the main cavity, and a pulsating nozzle periodically excites the airflow, forming stable pressure and velocity oscillations near the resonant frequency. A micro-perforated plate or porous sound-absorbing lining is configured inside the main cavity as an acoustic damping element, converting the oscillation energy into heat during shear friction and viscous dissipation, while simultaneously reducing transient fluctuations in flow and temperature, achieving heat integration and stable output. By adjusting the nozzle structure parameters, air supply flow rate, and bypass ratio, the oscillation intensity and dissipation power are changed, achieving controllable adjustment of the outlet temperature.

[0028] In this embodiment, the heat conversion cavity adopts a heat conversion structure based on acoustic oscillation and dissipation. Its main body is a closed, high-temperature resistant metal cavity, with one or more sets of short-tube-cavity resonators installed on the cavity sidewalls. A pulsating jet pipe is arranged at the cavity inlet, and its nozzle structure parameters can be set by changing the nozzle or by adjusting the structure. Inside the cavity, micro-perforated plates and porous sound-absorbing linings are arranged sequentially along the airflow direction. The pore diameter of the micro-perforated plates is 0.3–1.0 mm, and the porosity is 1%–3%. The porous sound-absorbing material is selected from high-temperature resistant metal fibers or ceramic-based materials. When the high-temperature gas enters the heat conversion cavity, it forms periodic velocity and pressure disturbances under the action of the pulsating jet pipes. When the disturbance frequency approaches the natural resonant frequency of the short-tube-cavity system, a stable acoustic oscillation field is formed within the cavity. During the oscillation process, the gas undergoes intense shear friction and viscous dissipation within the micro-perforated plates and porous sound-absorbing structure, continuously converting aerodynamic and acoustic energy into heat energy, thereby further increasing the gas temperature. By adjusting the opening of the bypass valve and bypass pipeline, the effective gas ratio entering the resonant cavity can be changed, thereby adjusting the oscillation intensity and the power dissipation per unit time, and achieving continuous controllability of the heat conversion cavity outlet temperature within the range of 200 to 350°C.

[0029] 3. Fuel injection pyrolysis unit: like Figure 3 As shown, the main components of the ammonia injection cracking unit include an injector, low-carbon fuel, a high-temperature gas flow inlet from the thermal conversion chamber, a high-temperature insulation layer, a catalyst / heat storage material, a high-temperature insulation layer, and a gas outlet. Located at the rear end of the thermal conversion chamber, the fuel injection cracking unit precisely controls the injection rate to introduce low-carbon fuels such as ammonia into the high-temperature gas flow (temperature above 120 degrees Celsius). High-temperature resistant heat storage materials or catalytic coatings are arranged within this flow. Under high-temperature conditions, ammonia undergoes a cracking reaction, providing hydrogen-rich gas and improving the reactivity of the post-treatment reaction.

[0030] In this embodiment, ammonia is used as the low-carbon fuel. The ammonia injection cracking device is located downstream of the thermal conversion chamber and mainly includes an injector, a high-temperature cracking chamber, a high-temperature resistant insulation layer, and a catalyst or heat storage material disposed within the cracking chamber. The cracking chamber is made of high-temperature resistant stainless steel or nickel-based alloy and is covered with a multi-layer insulation structure to reduce heat loss to the outside. The interior of the cracking chamber is filled with honeycomb or granular high-temperature resistant heat storage material, and its surface is coated with a metallic or non-precious metal catalytic coating suitable for ammonia cracking reaction. Under the high-temperature gas flow conditions output from the thermal conversion chamber, the ECU controls the injector to spray ammonia fuel into the cracking chamber in an atomized form. Ammonia undergoes a cracking reaction under high temperature and catalytic action to generate hydrogen and nitrogen. The hydrogen-rich gas produced by cracking enters the downstream oxidation catalyst with the gas flow, providing a hydrogen-rich and highly reactive atmosphere for the aftertreatment system.

[0031] 4. The main exhaust channel consists of an oxidation catalyst, a particulate filter, a selective catalytic reduction unit, and an ammonia escape catalyst: The hydrogen-rich gas from upstream reacts rapidly on the surface of the oxidation catalyst and the particulate filter carrier, releasing a large amount of heat, which quickly heats the carrier of the oxidation catalyst and the carriers of the downstream particulate filter, selective catalytic reduction device, and ammonia escape catalyst.

[0032] In this embodiment, the oxidation catalyst adopts a conventional DOC (Diesel Oxidation Catalyst) structure, whose catalytic coating exhibits high reactivity towards hydrogen-rich gas. When hydrogen-rich gas enters the DOC, it rapidly undergoes an oxidation reaction on its surface, releasing a large amount of heat. This heat rapidly heats the DOC support and the supports of the downstream particulate filter, selective catalytic reduction device, and ammonia escape catalyst. The particulate filter is used to capture particulate matter in the exhaust gas; the selective catalytic reduction device is used to reduce NOx in the exhaust gas at normal operating temperatures; and the ammonia escape catalyst is used to oxidize residual ammonia that has not participated in the reaction, further reducing the risk of ammonia emissions.

[0033] 5. Electronic Control Unit (ECU): Working in conjunction with the engine control system, it collects signals such as temperature, pressure, flow rate, NOx and ammonia concentration in real time, and performs closed-loop control on the speed of the electric centrifugal compressor heating module, the temperature of the thermal conversion chamber, the amount and timing of low-carbon fuel injection, and the start and stop of the system.

[0034] This embodiment compares the performance of a traditional heating system, resistance wire heating, with that of our system. Figure 4 The heat release time comparison graph contains two sets of temperature change curves. The solid line represents the temperature change of the system in this embodiment, and the dashed line represents the temperature change of the traditional resistance wire heating system. Analysis of the heating process: In terms of heating dynamics, the system in this embodiment heats up slowly in the initial stage, but accelerates significantly in the 5-10 second range, forming a rapid rise phase, and then quickly enters a stable state, demonstrating a nonlinear enhanced heating strategy. In contrast, the traditional system lacks an acceleration phase throughout, and the heating is uniform but the response is lagging.

[0035] Regarding reaching the urea injection start-up temperature, its temperature curve can break through the 200°C urea injection start-up temperature in about 9–10 seconds, with a steep heating process, demonstrating rapid start-up characteristics. In contrast, traditional heating systems require about 20 seconds to reach the same temperature, with a relatively gradual heating process and an almost linear growth trend. The system in this embodiment can enter the injection conditions earlier, allowing the SCR system to start earlier, effectively reducing NOx emissions during the cold start phase. At the same time, it is more stable in the high-temperature range, which helps to avoid urea crystallization problems. In contrast, traditional systems have a delayed injection start-up and relatively weak emission control capabilities in the low-temperature phase.

[0036] Therefore, the post-treatment system proposed in this embodiment has a stronger ability to rapidly and continuously heat up, and can heat the post-treatment device to a higher temperature (300°C vs. 220°C), which is conducive to achieving a more complete low-carbon emission post-treatment reaction; at the same time, it avoids the problem of weak heating in the high-temperature zone of the traditional resistance wire heating method; therefore, the system in this embodiment is significantly better than the traditional resistance wire heating method in terms of post-treatment system start-up performance and final temperature rise effect.

[0037] Example 2 One embodiment of the present invention provides a control method for an aftertreatment system of a low-carbon emission engine, comprising: Preheating control stage: The fuel injection pyrolysis unit remains off, relying solely on the electric centrifugal compression heating module and the thermal conversion chamber for physical heating and heat conversion; Cracking activation stage: When the outlet temperature of the thermal conversion chamber meets the preset conditions, the fuel injection cracking device is turned on to inject and crack low-carbon fuel, generate hydrogen-rich gas, and connect it to the main exhaust channel to provide normal operating temperature for the aftertreatment catalyst. Post-treatment temperature maintenance stage: When the inlet temperature of the selective catalytic reduction unit meets the preset conditions, the speed of the electric centrifugal compressor heating module is gradually reduced, the temperature is maintained by the exothermic reaction of the oxidation catalyst and the particulate filter, and the low-carbon fuel injection quantity is finely adjusted by closed-loop control. Normal emission control phase: When the inlet temperature of the selective catalytic reduction device reaches the ignition temperature, the rapid heating branch is shut off, and the system switches back to the main exhaust passage, with engine exhaust aftertreatment only performed through the main exhaust passage.

[0038] As one embodiment, the present invention provides a control method for the aftertreatment system of a low-carbon emission engine, which addresses the problems of slow temperature rise and easy ammonia escape in the aftertreatment system under typical operating conditions such as cold start, low-load operation, and urban congestion cycle when exhaust temperature is insufficient. The following provides a specific embodiment using the cold start condition as an example. The electronic control unit (ECU) adopts a state machine control architecture, such as... Figure 5 As shown, it includes the cold start preheating control stage, the pyrolysis activation stage, the post-treatment temperature rise and maintenance stage, the normal emission control stage, and the fault diagnosis and protection stage.

[0039] S101: Cold Start Preheating Control Stage When the engine starts and the inlet temperature of the selective catalytic reduction device is detected to be lower than a set threshold (e.g., 180°C), the cold start preheating control phase begins.

[0040] In this stage, the switching valve is first controlled to introduce ambient air or part of the exhaust gas into the heating branch of the electric centrifugal compression heating module. Based on the real-time collected inlet temperature, target outlet temperature and current gas flow rate, the required pressure ratio is calculated by back-calculating the thermodynamic model, and the target speed of the motor is further calculated. Then, the high-speed motor is driven to rapidly increase the speed, so that the gas can obtain a significant temperature rise and flow rate increase in a short time. The high-temperature gas after compression and heating enters the heat conversion chamber, and heat integration and stable temperature output are achieved through acoustic dissipation.

[0041] During this stage, the ammonia injection cracking unit remains shut down, relying solely on the electric centrifugal compressor heating module and the thermal conversion chamber for physical heating and heat conversion. The thermal conversion chamber reduces transient fluctuations in the compressor outlet temperature through acoustic oscillation and dissipation mechanisms, providing a stable high-temperature gas flow for the downstream reaction. When the compressor outlet temperature or the thermal conversion chamber outlet temperature is detected to reach a first temperature threshold (e.g., 210°C), the preheating conditions are deemed met, and the process proceeds to the next control stage.

[0042] Specifically, the control steps for the heat conversion cavity are as follows: S201: High-temperature gas introduction and initial pressure establishment. Under cold start or low-temperature conditions, the electric centrifugal compression heating module is activated to introduce the high-temperature gas after compression and heating into the inlet of the heat conversion chamber. The flow control valve establishes the basic flow rate and initial internal pressure level of the heat conversion chamber, providing a stable operating boundary for subsequent acoustic excitation and energy conversion.

[0043] S202: Pulsating jet excitation and pressure oscillation triggering. By controlling the nozzle structure parameters and air supply flow of the pulsating jet pipe, the airflow entering the main cavity generates periodic velocity and pressure disturbances, forming a controlled pulsating jet in the heat conversion cavity, triggering periodic oscillations in the cavity pressure and flow velocity.

[0044] S203: Short tube resonator coupling and resonant amplification. When the frequency of the pulsating jet is close to the natural resonant frequency of the short tube-cavity resonator, a stable and amplitude-controllable pressure oscillation field is formed in the main cavity through the acoustic coupling effect between the short tube resonator and the main cavity, realizing the efficient conversion of aerodynamic energy into acoustic energy.

[0045] S204: Acoustic dissipation and conversion of kinetic energy into thermal energy. Inside the main cavity, pressure and velocity oscillating airflow passes through a micro-perforated plate and a porous sound-absorbing structure. The oscillation energy is dissipated by shear friction and viscous dissipation within the channels, and acoustic energy and aerodynamic energy are continuously converted into thermal energy, thereby further increasing the temperature of the gas inside the cavity.

[0046] S205: Suppression of transient pressure and temperature fluctuations. Through the damping effect of the micro-perforated plate and porous sound-absorbing lining, high-frequency and low-frequency pressure pulsations are attenuated, reducing transient fluctuations in gas flow and temperature, so that a high-temperature airflow with stable pressure and uniform temperature is formed at the outlet of the heat conversion chamber.

[0047] S206: Bypass ratio adjustment and oscillation intensity control. Based on the target outlet temperature requirement, the flow control and the opening of the bypass valve and adjustable bypass pipeline are controlled to change the effective gas ratio entering the pulsating jet and the resonant cavity, thereby adjusting the acoustic oscillation intensity and the power dissipation per unit time, and achieving continuous and controllable adjustment of the outlet temperature.

[0048] S207: Stable high-temperature output and downstream coordination. After reaching the target pressure stability range and outlet temperature setpoint, the thermal conversion chamber is maintained in a controlled oscillation and dissipation state, continuously outputting high-temperature, low-fluctuation gas to the downstream ammonia cracking injection unit, providing a stable high-temperature environment for the ammonia cracking reaction.

[0049] S102: Ammonia cracking activation stage During this stage, the electric centrifugal compression heating module is kept running at a high speed to ensure sufficient gas flow and temperature. The heat provided by the electric centrifugal compression heating module is used to crack ammonia. The ammonia injection cracking device is then turned on, and a lean injection strategy is adopted to strictly control the equivalence ratio of ammonia to available oxygen to be much greater than 1, so that the reaction mainly occurs in the cracking region. The ammonia injection amount is calculated by model feedforward and fine-tuned in a closed loop in combination with the temperature rise rate of the DOC front end.

[0050] During this process, the temperature change rate of the DOC and particulate filter back end is monitored. When a clear inflection point is detected in the back end temperature curve and it enters a stable rising range, it indicates that the cascade exothermic reaction has been successfully activated. When the temperature of the DOC and particulate filter back end reaches the second threshold (e.g., 195°C, which is the inlet temperature of the selective catalytic reduction device) and the temperature rise rate tends to be stable, the subsequent temperature rise and maintenance stage begins.

[0051] Specifically, the control steps of the ammonia injection cracking unit are as follows: S301: System Activation and Operating Condition Determination. During engine cold starts or low-load operation, the Electronic Control Unit (ECU) collects exhaust temperature, aftertreatment device temperature, and engine operating status parameters in real time. When the aftertreatment inlet temperature is determined to be below the set ignition threshold, the operating mode of the ammonia injection cracking unit is activated.

[0052] S302: High-temperature gas flow conditions established. The ECU controls the electric centrifugal compressor heating module to work in tandem with the thermal conversion chamber to establish stable high-temperature gas flow conditions at the inlet of the ammonia injection cracking unit, ensuring that the gas temperature entering the unit reaches the minimum temperature range required for the ammonia cracking reaction.

[0053] S303: Precise control of ammonia injection quantity. After confirming that the high-temperature gas flow is stable, the ECU controls the injector to open according to the preset control strategy, and precisely adjusts the injection quantity and timing of ammonia or other low-carbon fuels according to the gas flow temperature, flow rate and target heating rate, to ensure that the pyrolysis reaction occurs safely and controllably inside the device.

[0054] S304: Cracking of ammonia or low-carbon fuels. The injected ammonia or low-carbon fuel undergoes a cracking reaction under the action of a high-temperature gas flow and a catalyst or heat storage material, producing hydrogen and nitrogen.

[0055] S305: Synergistic Construction of Hydrogen-Rich Atmosphere and Post-Treatment. The hydrogen-rich gas produced by cracking is carried by the high-temperature gas flow into the downstream catalytic DPF and selective catalytic reduction unit, significantly improving their low-temperature reactivity, accelerating the post-treatment system to enter the high-efficiency operating window, and suppressing the risk of unreacted ammonia discharge.

[0056] S306: Dynamic Adjustment and Safe Exit. When the aftertreatment system temperature reaches or exceeds the target operating temperature, the ECU gradually reduces the ammonia injection volume or shuts down the ammonia injection cracking device, and switches to the normal exhaust control mode according to the operating conditions to ensure the safety, stability and durability of the system under different operating conditions.

[0057] S103: Post-processing heating and maintenance stage During this stage, the control objective shifts from rapid temperature rise to stable maintenance. The speed of the electric centrifugal compressor heating module is gradually reduced to decrease power consumption and system load. At the same time, the exothermic reaction of the oxidation catalyst and particulate filter is used to maintain the temperature plateau. Based on the DOC and the temperature at the downstream end of the particulate filter and the inlet temperature of the selective catalytic reduction unit, a proportional-integral control algorithm is used to finely adjust the ammonia injection quantity to stabilize the system temperature within the set range and avoid temperature oscillation.

[0058] During this stage, the injection of urea or ammonia into the main selective catalytic reduction unit is prohibited to prevent ammonia deposition and escape under low-temperature conditions. Once the inlet temperature of the selective catalytic reduction unit reaches its ignition temperature (e.g., 200°C), the aftertreatment system is considered to be operating normally, and the system switches to the normal emission control stage.

[0059] S104: Normal Emission Control Phase After entering the normal emission control phase, the control switching valve returns to the main exhaust channel, the electric centrifugal compressor heating module stops or enters a low-speed standby state, and the thermal conversion chamber and ammonia cracking injection branch are closed. At this time, the system fully switches to the conventional SCR (Selective Catalytic Reduction) emission control strategy, implementing urea injection closed-loop control based on NOx sensor signals to achieve efficient NOx reduction, and the ammonia escape catalyst further treats any remaining ammonia.

[0060] S105: Fault Diagnosis and Protection Control The fault diagnosis and protection strategy operates as an independent module running in parallel throughout all stages of system operation. Once conditions such as overheating, abnormal pressure, ammonia leakage, or actuator failure are detected, the ECU immediately interrupts ammonia injection, gradually reduces the compressor speed, and forces the switching valve back to the main exhaust passage. At the same time, it records the fault code to ensure that engine operation is not affected.

[0061] Example 3 One embodiment of the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the after-treatment system of a low-carbon emission engine.

[0062] Example 4 In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided for storing computer instructions, which, when executed by a processor, implement the after-treatment system of a low-carbon emission engine.

[0063] Example 5 One embodiment of the present invention provides an electronic device, including: a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to implement the after-treatment system of a low-carbon emission engine.

[0064] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0065] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0066] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An aftertreatment system for a low-carbon emission engine, characterized in that, Add a rapid heating branch to the main exhaust passage; The rapid heating branch is configured to: compress and heat the mixture of ambient air and engine exhaust gas under the condition that the exhaust temperature of the low-carbon emission engine is insufficient, to obtain a high-temperature airflow within a preset temperature range, inject low-carbon fuel into the high-temperature airflow, and after the hydrogen-rich gas produced by the cracking reaction enters the main exhaust channel, an exothermic reaction occurs, providing the aftertreatment catalyst in the main exhaust channel with normal operating temperature for aftertreatment of engine exhaust gas.

2. The aftertreatment system for a low-carbon emission engine as described in claim 1, characterized in that, The rapid heating branch includes an electric centrifugal compression heating module, which consists of a high-speed motor, a centrifugal compression impeller, and an electronic control power module. It is used to draw in a mixture of ambient air and engine exhaust gas, compress it, and increase the gas temperature and flow rate to obtain high-temperature gas after compression and heating.

3. The aftertreatment system for a low-carbon emission engine as described in claim 2, characterized in that, The rapid heating branch also includes a heat conversion chamber located downstream of the electric centrifugal compression heating module. It adopts a heat conversion structure based on acoustic oscillation and dissipation to further integrate and stabilize the heat output of the high-temperature gas, thereby obtaining a high-temperature airflow within a preset temperature range.

4. The aftertreatment system for a low-carbon emission engine as described in claim 3, characterized in that, The rapid heating branch also includes a fuel injection cracking device located at the rear end of the thermal conversion chamber. It includes an injector, low-carbon fuel, a high-temperature gas flow inlet from the thermal conversion chamber, a high-temperature insulation layer, a catalyst or heat storage material, a high-temperature insulation layer, and a gas outlet. It is used to introduce low-carbon fuel with controlled injection volume into the high-temperature gas flow to undergo a cracking reaction and provide hydrogen-rich gas.

5. The aftertreatment system for a low-carbon emission engine as described in claim 1, characterized in that, The main exhaust channel consists of an oxidation catalyst, a particulate filter, a selective catalytic reduction device, and an ammonia escape catalyst connected in sequence.

6. A control method for an aftertreatment system of a low-carbon emission engine, characterized in that, For controlling the post-processing system as described in any one of claims 1-5, including: Preheating control stage: The fuel injection pyrolysis unit remains off, relying solely on the electric centrifugal compression heating module and the thermal conversion chamber for physical heating and heat conversion; Cracking activation stage: When the outlet temperature of the thermal conversion chamber meets the preset conditions, the fuel injection cracking device is turned on to inject and crack low-carbon fuel, generate hydrogen-rich gas, and connect it to the main exhaust channel to provide normal operating temperature for the aftertreatment catalyst. Post-treatment temperature maintenance stage: When the inlet temperature of the selective catalytic reduction unit meets the preset conditions, the speed of the electric centrifugal compressor heating module is gradually reduced, the temperature is maintained by the exothermic reaction of the oxidation catalyst and the particulate filter, and the low-carbon fuel injection quantity is finely adjusted by closed-loop control. Normal emission control phase: When the inlet temperature of the selective catalytic reduction device reaches the ignition temperature, the rapid heating branch is shut off, and the system switches back to the main exhaust passage, with engine exhaust aftertreatment only performed through the main exhaust passage.

7. The aftertreatment system control method for a low-carbon emission engine as described in claim 6, characterized in that, It also includes fault diagnosis and protection control, specifically: Once a fault is detected, immediately interrupt low-carbon fuel injection, gradually reduce compressor speed, and forcibly switch back to the main exhaust passage. At the same time, record the fault code to ensure that engine operation is not affected.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the aftertreatment system control method for a low-carbon emission engine as described in any one of claims 6-7.

9. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium is used to store computer instructions, which, when executed by a processor, implement the after-treatment system control method for a low-carbon emission engine as described in any one of claims 6-7.

10. An electronic device, characterized in that, include: The device includes a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to perform a control method for an aftertreatment system of a low-carbon emission engine as described in any one of claims 6-7.

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