Post-processing system and method and vehicle

Abstract

The invention discloses a post-processing system, a post-processing method and a vehicle, which can realize lower emission under the boundary of keeping a post-processing installation space basically unchanged. The post-treatment system comprises a first nitrogen oxide treatment device, a second nitrogen oxide treatment device and a third nitrogen oxide treatment device, and the first nitrogen oxide treatment device is used for reducing nitrogen oxide and carrying out ammonia gas oxidation removal; the particulate matter treatment device is used for capturing particulate matters and catalyzing the particulate matters to generate nitrogen dioxide; the second nitrogen oxide treatment device is used for reducing nitrogen oxide and carrying out ammonia gas oxidation removal; the urea nozzle is used for spraying urea; the temperature sensor is used for detecting the temperature; the nitrogen oxide sensor is used for detecting the concentration of nitrogen oxide.

Description

Technical Field

[0001] This application relates to the technical field of emission control, and particularly to a post-treatment system, method, and vehicle. Background Art

[0002] With the advancement of the formulation of the new generation of emission standards, more stringent comprehensive control requirements for tail gas emissions are put forward: on the one hand, it is necessary to further reduce the emission limits of nitrogen oxides (NOx) and particulate matter number (PN), and on the other hand, a new control index for nitrous oxide (N2O) emissions is added. However, the existing post-treatment system architecture has been finalized based on the previous emission standards, and its carrier layout space, catalyst coating amount, and temperature control strategy have all formed fixed solutions. When it is necessary to meet the upgraded emission control requirements, the traditional technical solution inevitably leads to a significant increase in the system volume by simply increasing the catalyst dosage or extending the post-treatment process. The increase in the volume of the post-treatment system not only causes difficulties in the layout of the vehicle chassis, but also greatly increases the development cost due to the need to re-design the exhaust system route and adjust the suspension system parameters. Summary of the Invention

[0003] To solve the above technical problems, this application is proposed. Embodiments of this application provide a post-treatment system, method, and vehicle that can achieve lower emissions while maintaining the basic boundary of the post-treatment installation space unchanged.

[0004] According to a first aspect of this application, a post-treatment system is provided, including: a first nitrogen oxide treatment device located downstream of the exhaust gas outlet of the engine, the first nitrogen oxide treatment device being used to reduce nitrogen oxides and perform ammonia oxidation and removal; a particulate matter treatment device located downstream of the first nitrogen oxide treatment device, the particulate matter treatment device being used to capture particulate matter and catalytically generate nitrogen dioxide; a second nitrogen oxide treatment device located downstream of the particulate matter treatment device, the second nitrogen oxide treatment device being used to reduce nitrogen oxides and perform ammonia oxidation and removal; a urea nozzle for injecting urea into the first nitrogen oxide treatment device and the second nitrogen oxide treatment device; a temperature sensor for detecting the temperature before the intake end of the first nitrogen oxide treatment device, the temperature before the intake end of the particulate matter treatment device, and the temperature before the intake end of the second nitrogen oxide treatment device; and a nitrogen oxide sensor for detecting the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, and the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device.

[0005] As a possible implementation, the first nitrogen oxide treatment device is coated with a selective catalytic reduction catalyst and an ammonia slip catalyst, and the second nitrogen oxide treatment device is coated with a selective catalytic reduction catalyst and an ammonia slip catalyst.

[0006] As a possible implementation, the particulate matter treatment device is coated with a catalyst of an oxidation catalytic converter formulation and a catalyst of a particulate trap formulation.

[0007] According to a second aspect of the present application, there is provided a control method for a post-treatment system, which is applied to the post-treatment system described in the first aspect or any one of the implementations in the first aspect. The control method of the post-treatment system includes: calculating the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the inlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the first nitrogen oxide treatment device, and the space velocity of the first nitrogen oxide treatment device; adjusting the urea injection amount injected into the first nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the first nitrogen oxide treatment device, and a preset nitrogen oxide ratio emission; calculating the ratio of nitrogen dioxide to nitrogen oxides output by the particulate matter treatment device according to the temperature before the inlet end of the particulate matter treatment device, the temperature before the inlet end of the second nitrogen oxide treatment device, and the space velocity of the particulate matter treatment device; calculating the urea injection amount of the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the second nitrogen oxide treatment device, and the ratio of nitrogen dioxide to nitrogen oxides output by the particulate matter treatment device; adjusting the urea injection amount injected into the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and a second preset nitrogen oxide ratio emission.

[0008] As a possible implementation, calculating the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the inlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the first nitrogen oxide treatment device, and the space velocity of the first nitrogen oxide treatment device includes: determining the nitrogen oxide conversion efficiency of the first nitrogen oxide treatment device according to the temperature before the inlet end of the first nitrogen oxide treatment device and the space velocity of the first nitrogen oxide treatment device; calculating the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the inlet end of the first nitrogen oxide treatment device, and the nitrogen oxide conversion efficiency of the first nitrogen oxide treatment device.

[0009] As a possible implementation, according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the first nitrogen oxide treatment device, and the preset nitrogen oxide specific emission, adjust the urea injection amount sprayed into the first nitrogen oxide treatment device, including: calculating the actual nitrogen oxide specific emission of the first nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device and the exhaust gas data; when the actual nitrogen oxide specific emission of the first nitrogen oxide treatment device exceeds the emission range of the first preset nitrogen oxide specific emission, based on the deviation value between the actual nitrogen oxide specific emission of the first nitrogen oxide treatment device and the first preset nitrogen oxide specific emission, adjust the urea injection amount of the first nitrogen oxide treatment device.

[0010] As a possible implementation, according to the temperature before the inlet end of the particulate matter treatment device, the temperature before the inlet end of the second nitrogen oxide treatment device, and the space velocity of the particulate matter treatment device, calculate the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device, including: obtaining a weighted temperature value according to the temperature before the inlet end of the particulate matter treatment device and the temperature before the inlet end of the second nitrogen oxide treatment device; determining the preset ratio of nitrogen dioxide and nitrogen oxides according to the weighted temperature value and the space velocity of the particulate matter treatment device; calculating the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device based on the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device and the preset ratio of nitrogen dioxide and nitrogen oxides.

[0011] As a possible implementation, according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and the second preset nitrogen oxide specific emission, adjust the urea injection amount sprayed into the second nitrogen oxide treatment device, including: calculating the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and the exhaust gas data; when the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device exceeds the emission range of the second preset nitrogen oxide specific emission, based on the deviation value between the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device and the second preset nitrogen oxide specific emission, adjust the urea injection amount of the second nitrogen oxide treatment device.

[0012] As a possible implementation, the control method of the after-treatment system further includes: calculating the carbon loading according to the first pressure difference of the particulate matter treatment device and the exhaust gas data; wherein, the first pressure difference represents the pressure difference between the inlet end and the outlet end of the particulate matter treatment device; when the carbon loading is greater than or equal to the first limit value, adjust the urea injection amount and the temperature; when the carbon loading is greater than or equal to the second limit value, trigger a parked regeneration request; wherein, the second limit value is greater than the first limit value.

[0013] According to a third aspect of the present application, a vehicle is provided, including: an engine; a post-treatment system as described in the first aspect or any one of the implementation manners of the first aspect, the post-treatment system being located downstream of the exhaust gas outlet of the engine; a controller communicatively connected to the post-treatment system, the controller being configured to control the post-treatment system to execute the control method of the post-treatment system as described in the second aspect or any one of the implementation manners of the second aspect. The post-treatment system, method and vehicle provided by the present application realize the reduction of nitrogen oxides and the oxidation and removal of ammonia by arranging a multifunctional catalyst in the first nitrogen oxide treatment device and combining with the urea injected by the urea nozzle, arranging a multifunctional catalyst in the particulate matter treatment device to capture particulate matter and catalytically generate nitrogen dioxide, and in the second nitrogen oxide treatment device, combining with the urea injected by the urea nozzle to reduce nitrogen oxides and perform ammonia oxidation and removal. Through the design of the multifunctional catalyst, the post-treatment installation space can be kept basically unchanged. On this basis, by monitoring the temperature with a temperature sensor and combining with the nitrogen oxide sensors to monitor the nitrogen oxide concentration in each link, the injection amount of the urea nozzle can be flexibly adjusted to prevent waste of the reducing agent and reduce the possibility of secondary pollution caused by ammonia leakage after the catalyst catalysis, so as to achieve lower emissions. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of a post-treatment system provided by an exemplary embodiment of the present application.

[0016] Figure 2 It is a schematic flowchart of a control method of a post-treatment system provided by an exemplary embodiment of the present application.

[0017] Figure 3 It is a schematic structural diagram of a control device of a post-treatment system provided by an exemplary embodiment of the present application.

[0018] Explanation of the reference numerals: A1 - first nitrogen oxide treatment device; A2 - particulate matter treatment device; A3 - second nitrogen oxide treatment device; N1 - first nitrogen oxide sensor; N2 - second nitrogen oxide sensor; N3 - third nitrogen oxide sensor; T1 - first temperature sensor; T2 - second temperature sensor; T3 - third temperature sensor; Inj1 - first urea nozzle; Inj2 - second urea nozzle. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] With the continuous improvement of emission control requirements for internal combustion engines, restrictions on pollutants such as nitrogen oxides (NOx) and particulate matter (PN) have become increasingly stringent, and emission monitoring of nitrous oxide (N2O) has been added. In this context, the vehicle emission test conditions have also been further optimized, with more emphasis on pollutant control capabilities under actual driving conditions. However, the current design space for vehicle after-treatment systems has tended to solidify, especially in the National VI stage, where the layout of after-treatment devices is basically finalized. If the volume of the newly developed after-treatment system is significantly increased, due to the limited space in the engine compartment, an overly large after-treatment device will be difficult to arrange reasonably under the existing chassis architecture, which may affect the assembly of the vehicle and even cause structural interference. If the exhaust system needs to be redesigned or the layout of surrounding components needs to be adjusted, the cost of materials, verification and production line modification will be greatly increased.

[0021] Based on the above problems, Figure 1 is a schematic diagram of a post-processing system provided by an exemplary embodiment of the present application. Figure 1 For reference, the specific structure of the post-processing system is described in detail.

[0022] First, the aftertreatment system includes a first nitrogen oxide treatment device A1. The first nitrogen oxide treatment device A1 is located downstream of the exhaust gas outlet of the engine. The first nitrogen oxide treatment device A1 is used to reduce nitrogen oxides and carry out ammonia oxidation and removal. A first temperature sensor T1, a first urea nozzle Inj1, and a first nitrogen oxide sensor N1 are arranged between the first nitrogen oxide treatment device A1 and the downstream of the exhaust gas outlet. The first temperature sensor T1 is arranged at the intake end of the first nitrogen oxide treatment device A1, and the first temperature sensor T1 is used to detect the temperature before the intake end of the first nitrogen oxide treatment device A1. The first urea nozzle Inj1 is arranged at the intake end of the first nitrogen oxide treatment device A1 and is located downstream of the first temperature sensor T1. The first urea nozzle Inj1 is used to inject urea into the first nitrogen oxide treatment device A1. The first nitrogen oxide sensor N1 is arranged at the intake end of the first nitrogen oxide treatment device A1, and the first nitrogen oxide sensor N1 is located downstream of the first urea nozzle Inj1. The first nitrogen oxide sensor N1 is used to detect the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device A1.

[0023] The first nitrogen oxide treatment device A1 is coated with a selective catalytic reduction (SCR) catalyst and an ammonia slip catalyst (ASC): The SCR catalyst is mainly used to eliminate NOx (nitrogen oxides, including NO and NO2) in the exhaust gas. Fuel is injected into the exhaust gas or a reducing agent is added additionally. With a suitable catalyst, the reaction between the reducing agent and NOx is promoted, and at the same time, the non-selective oxidation reaction between the reducing agent and oxygen is inhibited. Commonly used urea-SCR catalysts are V2O5 / W2O3 / TiO2 and metal oxide / zeolite. The vanadium-based catalyst has high selectivity for NOx and a wide high-efficiency temperature window, and at the same time has high sulfur resistance. The zeolite-type catalyst has a strong adsorption capacity for NH3. In addition, sulfur oxides will form sulfates in the copper-based SCR, reducing the active sites of the catalyst, blocking the small holes, and reducing the conversion efficiency of SCR for NOx. Therefore, when a certain amount of sulfur oxides are trapped in the SCR, it is necessary to carry out desulfurization on it.

[0024] The reaction principle of SCR technology: Urea hydrolysis to ammonia: (NH2)2CO + H2O → 2NH3 + CO2 SCR aftertreatment reaction: NO + NO2 + 2NH3 → 2N2 + 3H2O 4NO + O2 + 4NH3 → 4N2 + 6H2O 2NO2 + O2 + 4NH3 → 3N2 + 6H2O The actual reducing agent participating in the selective catalytic reduction reaction in the SCR is ammonia (NH3). However, due to the high corrosiveness of ammonia, there are difficulties in storing and transporting liquid ammonia and aqueous ammonia, so they cannot be directly used in on-vehicle SCR systems. Currently, aqueous urea solution is generally used as the reducing agent. Also, compared with aqueous urea solutions of other concentrations, the aqueous urea solution with a concentration of 32.5% has the lowest freezing point of -11°C. Therefore, the 32.5% aqueous urea solution is generally used as the standard reducing agent for SCR and is named AdBlue.

[0025] Since the SCR catalyst may cause NH3 escape due to excessive urea injection or low temperature, to reduce the secondary pollution that may be caused by ammonia leakage, an ammonia slip catalyst (ASC) is set up. The ASC oxidizes the escaped ammonia to generate harmless nitrogen (N2) and water (H2O), preventing ammonia from being directly discharged into the atmosphere (NH3 itself is irritating and may form secondary particulate matter).

[0026] The main chemical reactions of the ASC are as follows: Ideally, NH3 is selectively oxidized to N2: 4NH3 + 3O2 → 2N2 + 6H2O Inhibition of N2O generation: 2NH3 + 2O2 → N2O + 3H2O Therefore, the selective catalytic reduction catalyst and the ammonia slip catalyst coated in the first nitrogen oxide treatment device A1, combined with the urea injected by the first urea nozzle Inj1, reduce nitrogen oxides in the tail gas and oxidize and remove ammonia.

[0027] Then, the aftertreatment system further includes a particulate matter treatment device A2. The particulate matter treatment device A2 is located downstream of the first nitrogen oxide treatment device A1. The particulate matter treatment device A2 is used to capture particulate matter and catalytically generate nitrogen dioxide. A second temperature sensor T2 and a second nitrogen oxide sensor N2 are arranged between the particulate matter treatment device A2 and the first nitrogen oxide treatment device A1. The second nitrogen oxide sensor N2 is arranged at the outlet end of the first nitrogen oxide treatment device A1, or it can also be the inlet end of the particulate matter treatment device A2. The second nitrogen oxide sensor N2 is used to detect the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device A1, or the nitrogen oxide concentration entering the inlet end of the particulate matter treatment device A2. The second temperature sensor T2 is arranged at the inlet end of the particulate matter treatment device A2, or it can also be the outlet end of the first nitrogen oxide treatment device A1. The second temperature sensor T2 is arranged downstream of the second nitrogen oxide sensor N2. The second temperature sensor T2 is used to detect the temperature before the inlet end of the particulate matter treatment device A2, or it can be understood as the temperature at the outlet end of the first nitrogen oxide treatment device A1.

[0028] The particulate matter treatment device A2 is coated with catalysts of an oxidation catalytic converter formulation and a particulate trap formulation. Among them, the catalyst of the oxidation catalytic converter formulation is an oxidation-type catalyst. For example, the oxidation catalytic technology of the catalyst for particulate matter (Diesel Oxidation Catalysis, DOC) is to coat a noble metal catalyst (such as Pt, etc.) on a honeycomb ceramic carrier. Its purpose is to reduce the chemical reaction activation energy of HC, CO, and SOF in the engine exhaust gas, so that these substances can undergo oxidation reactions with the oxygen in the exhaust gas at a lower temperature and finally be converted into CO2 and H2O. The oxidation-type catalytic converter does not require a regeneration system and a control device, and has the characteristics of simple structure and good reliability.

[0029] The particulate matter trapping technology (Diesel Particulate Filter, DPF) mainly filters and traps the particulate matter in the engine exhaust through diffusion, deposition, and impingement mechanisms. When the exhaust gas flows through the trap, the particulate matter is trapped inside the filter element of the filter body, and the relatively clean exhaust gas is discharged into the atmosphere. The working principle of the catalyst of the particulate trap formulation is that when the engine exhaust gas flows through the oxidation-type catalyst (DOC), at a temperature of 200 - 600 °C, CO and HC are first almost completely oxidized into CO2 and H2O, and at the same time NO is converted into NO2. After the exhaust gas comes out of the DOC and enters the DPF catalyst, the particulate matter is trapped inside the filter element of the filter body, and the relatively clean exhaust gas is discharged into the atmosphere.

[0030] NO2 has a strong oxidation ability for the trapped particles. The generated NO2 is used as an oxidant to remove the particulate matter in the particulate trap and generate CO2, while NO2 is reduced back to NO, thus achieving the purpose of removing particulate matter.

[0031] Therefore, in the particulate matter treatment device A2, the reaction principle of the catalyst of the oxidation catalytic converter formulation is: 2NO + O2 → 2NO2 2CO + O2 → 2CO2 2CH + O2 → CO2 + H2O The reaction principle of the catalyst of the particulate trap formulation is: C + 2NO2 → CO2 + 2NO Finally, the post-treatment system further includes a second nitrogen oxide treatment device A3, which is located downstream of the particulate matter treatment device A2. The second nitrogen oxide treatment device A3 is used to reduce nitrogen oxides and perform ammonia oxidation and removal. A third temperature sensor T3 and a second urea nozzle Inj2 are provided between the second nitrogen oxide treatment device A3 and the particulate matter treatment device A2. The third temperature sensor T3 is provided at the intake end of the second nitrogen oxide treatment device A3 or at the outlet end of the particulate matter treatment device A2. The third temperature sensor T3 is used to detect the temperature before the intake end of the second nitrogen oxide treatment device A3. The second urea nozzle Inj2 is provided downstream of the third temperature sensor T3 and at the intake end of the second nitrogen oxide treatment device A3. The second urea nozzle Inj2 is used to inject urea into the second nitrogen oxide treatment device A3. In addition, a third nitrogen oxide sensor N3 is provided downstream of the second nitrogen oxide treatment device A3. The third nitrogen oxide sensor N3 is used to detect the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device A3. In the second nitrogen oxide treatment device A3, the same selective catalytic reduction catalyst and ammonia slip catalyst as those in the first nitrogen oxide treatment device A1 are coated. Therefore, the reaction principle in the second nitrogen oxide treatment device A3 is the same as that in the first nitrogen oxide treatment device A1. Since the regeneration process of the particulate matter treatment device A2 may cause a large fluctuation in the exhaust gas temperature, this temperature change may temporarily deviate the upstream SCR catalyst from the optimal operating temperature window, resulting in a decrease in the nitrogen oxide conversion efficiency. Therefore, a second nitrogen oxide treatment device A3 is added to inject additional urea to compensate for the possible temperature fluctuations or uneven ammonia distribution after regeneration in the particulate matter treatment device A2, achieving lower emissions.

[0032] Based on the structure of the post-treatment system proposed above, lower emissions can be achieved through appropriate catalyst design and post-treatment control while keeping the post-treatment installation space basically unchanged. Therefore, a control method for the post-treatment system is proposed below, which can achieve lower emissions and higher environmental friendliness based on the structure of this post-treatment system. Figure 2 is a schematic flow chart of the control method for the post-treatment system provided by an exemplary embodiment of the present application. The following will be combined with Figure 2 to introduce the control method for the post-treatment system provided by the embodiment of the present application in more detail.

[0033] First, according to the exhaust gas data, the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, the temperature before the intake end of the first nitrogen oxide treatment device, and the space velocity of the first nitrogen oxide treatment device, calculate the urea injection amount of the first nitrogen oxide treatment device (see Figure 2 S210).

[0034] In some embodiments, the exhaust gas data includes data related to the exhaust gas, such as exhaust gas density and exhaust gas mass.

[0035] In some embodiments, the NOx conversion efficiency of the first NOx treatment device can be determined based on the temperature before the inlet end of the first NOx treatment device and the space velocity of the first NOx treatment device. The space velocity is obtained by dividing the exhaust gas mass flow rate by the product of the exhaust gas density and the volume of the first NOx treatment device. For example, through the catalyst characteristic curve (MAP) built into the aftertreatment system, with the temperature before the inlet end and the space velocity as input parameters, the theoretical conversion efficiency of the selective catalytic reduction (SCR) for nitrogen oxides (NOx) under the current working conditions is calculated in real time. This MAP is constructed based on a large amount of experimental data and reflects the performance limits of the catalyst under different boundary conditions. Obtaining the NOx conversion efficiency of the first NOx treatment device can provide a data basis for subsequent adjustment of the urea injection amount. Then, based on the exhaust gas data (such as exhaust gas mass), the NOx concentration at the inlet end of the first NOx treatment device, and the NOx conversion efficiency of the first NOx treatment device, the urea injection amount of the first NOx treatment device can be calculated. After calculating the actual urea injection amount, the actual urea injection amount can be adjusted according to requirements, such as increasing or decreasing, to avoid waste caused by excessive urea or incomplete reaction due to insufficient urea.

[0036] Second, adjust the urea injection amount sprayed into the first NOx treatment device according to the NOx concentration at the outlet end of the first NOx treatment device, the temperature before the inlet end of the first NOx treatment device, and the preset NOx specific emission (see Figure 2 S220).

[0037] In some embodiments, the actual NOx specific emission of the first NOx treatment device is calculated based on the NOx concentration at the outlet end of the first NOx treatment device, the exhaust gas mass flow rate, and the power; when the actual NOx specific emission of the first NOx treatment device exceeds the emission range of the first preset NOx specific emission, the urea injection amount of the first NOx treatment device is adjusted based on the deviation value between the actual NOx specific emission and the first preset NOx specific emission of the first NOx treatment device.

[0038] As a possible implementation of adjusting the urea injection amount of the first nitrogen oxide treatment device, a value of the first preset nitrogen oxide ratio emission (e.g., 7 g / kWh) can be preset in advance. When the value of the first preset nitrogen oxide ratio emission is greater than the actual nitrogen oxide ratio emission, the PI controller uses the deviation value between the actual nitrogen oxide ratio emission of the first nitrogen oxide treatment device and the first preset nitrogen oxide ratio emission to reduce the urea injection amount. When the value of the first preset nitrogen oxide ratio emission is less than the actual nitrogen oxide ratio emission, the PI controller uses the deviation value between the actual nitrogen oxide ratio emission of the first nitrogen oxide treatment device and the first preset nitrogen oxide ratio emission to increase the urea injection amount. When the value of the first preset nitrogen oxide ratio emission is equal to the actual nitrogen oxide ratio emission, the urea injection amount can be not adjusted.

[0039] Dynamically adjusting the urea injection amount of the first nitrogen oxide treatment device can improve the NOx conversion efficiency, optimize the urea utilization rate, reduce ammonia slip, and extend the catalyst life, thereby enhancing the reliability of the first nitrogen oxide treatment device.

[0040] Third, according to the temperature before the intake end of the particulate matter treatment device, the temperature before the intake end of the second nitrogen oxide treatment device, and the space velocity of the particulate matter treatment device, calculate the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device (see S230 in Figure 2 ).

[0041] In some embodiments, a weighted temperature value can be obtained first according to the temperature before the intake end of the particulate matter treatment device and the temperature before the intake end of the second nitrogen oxide treatment device. Then, according to the weighted temperature value and the space velocity of the particulate matter treatment device, a preset ratio of nitrogen dioxide and nitrogen oxides (NO2 / NOx ratio) is determined. For example, the basic ratio of nitrogen dioxide and nitrogen oxides (preset ratio of nitrogen dioxide and nitrogen oxides) is obtained by looking up the MAP according to the weighted temperature value and the space velocity of the particulate matter treatment device. Finally, based on the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device and the preset ratio of nitrogen dioxide and nitrogen oxides, the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device is calculated. The ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device can be used as reference data for adjusting the urea injection amount of the subsequent second nitrogen oxide treatment device to achieve low-emission environmental post-treatment.

[0042] Fourth, according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the intake end of the second nitrogen oxide treatment device, and the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device, calculate the urea injection amount of the second nitrogen oxide treatment device (see S240 in Figure 2 ).

[0043] In some embodiments, the MAP can be queried based on the temperature and space velocity before the intake end of the second nitrogen oxide treatment device to determine the conversion efficiency of NOx, and then the conversion efficiency of NOx can be corrected according to the ratio of nitrogen dioxide to nitrogen oxides. Finally, based on the waste gas mass, the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, and the conversion efficiency, the urea injection amount before the second nitrogen oxide treatment device is calculated. The space velocity is the waste gas mass flow rate divided by the product of the waste gas density and the volume of the second nitrogen oxide treatment device.

[0044] Fifth, according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and the second preset nitrogen oxide specific emission, adjust the urea injection amount sprayed into the second nitrogen oxide treatment device (see Figure 2 S250).

[0045] In some embodiments, after calculating the actual urea injection amount before the second nitrogen oxide treatment device, a second preset nitrogen oxide specific emission (such as 0.1 g / kWh) of the second nitrogen oxide treatment device is preset, and the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device is calculated according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device, the waste gas mass flow rate, and the power. When the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device exceeds the emission range of the second preset nitrogen oxide specific emission, based on the deviation value between the actual nitrogen oxide specific emission and the second preset nitrogen oxide specific emission of the second nitrogen oxide treatment device, adjust the urea injection amount of the second nitrogen oxide treatment device.

[0046] As a possible implementation of adjusting the urea injection amount of the second nitrogen oxide treatment device, when the second preset nitrogen oxide specific emission is greater than the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device, the PI controller uses the deviation value between the actual nitrogen oxide specific emission and the second preset nitrogen oxide specific emission of the second nitrogen oxide treatment device to reduce the urea injection amount. When the second preset nitrogen oxide specific emission is less than the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device, the PI controller uses the deviation value between the actual nitrogen oxide specific emission and the second preset nitrogen oxide specific emission of the second nitrogen oxide treatment device to increase the urea injection amount. When the second preset nitrogen oxide specific emission is equal to the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device, the urea injection amount is not adjusted.

[0047] Dynamically adjusting the urea injection amount of the second nitrogen oxide treatment device can reduce urea consumption, improve the utilization rate of urea, and reduce the ammonia leakage amount, which can improve the SCR treatment efficiency and optimize the ASC workload. By extending the catalyst life and reducing urea consumption, the service life of the second nitrogen oxide treatment device can also be extended, thereby reducing the use cost.

[0048] In addition, since the particulate matter treatment device uses a multifunctional catalyst, the passive regeneration effect is slightly worse compared to the independent DOC and DPF functions. To ensure the same level of regeneration effect, the carbon loading can be calculated based on the first pressure difference of the particulate matter treatment device and the exhaust gas data. The first pressure difference represents the pressure difference between the inlet end and the outlet end of the particulate matter treatment device. When the carbon loading is greater than or equal to the first limit, the urea injection amount and temperature are adjusted. When the carbon loading is greater than or equal to the second limit, a parked regeneration request is triggered. The second limit is greater than the first limit.

[0049] In some embodiments, the carbon loading is calculated based on the pressure difference across the particulate matter treatment device and the exhaust gas volume flow rate. The exhaust gas volume flow rate is equal to the exhaust gas mass flow rate divided by the exhaust gas density.

[0050] In other embodiments, when the carbon loading is greater than or equal to the first limit, in order to quickly reduce the carbon loading, the following measures can be taken: Measure 1, increase the set value of NOx (the value of the first preset NOx specific emission) at the second temperature sensor (collecting the temperature at the outlet end of the first NOx treatment device), increase the total amount of NOx, so that the amount of NO2 generated in the particulate matter treatment device will also increase. Measure 2, trigger thermal management according to the current average temperature and the rate of change to increase the temperature. The average temperature is calculated by weighted averaging the temperature at the outlet end of the particulate matter treatment device collected by the third temperature sensor and the calculated temperature after the second NOx treatment device. Using the temperature at the outlet end of the particulate matter treatment device and the exhaust gas flow rate as inputs, the downstream temperature is calculated based on the carrier heat capacity and the law of conservation of energy. The average temperature change rate is obtained by dividing the average temperature change amount over a fixed time by the fixed time. When the average temperature is higher than the first preset temperature, the intake valve of the engine, etc. is used to increase the temperature. When the average temperature is within the range of the first preset temperature and the second preset temperature, if the average temperature change rate is less than or equal to the change rate limit, the intake valve of the engine, etc. and in-cylinder post-injection are used to increase the temperature. If the average temperature change rate is greater than the change rate limit, the intake valve of the engine, etc. is used to increase the temperature. When the average temperature is lower than the second preset temperature, the intake valve of the engine, etc. and in-cylinder post-injection are used to increase the temperature.

[0051] In other embodiments, when the carbon loading is greater than or equal to the second limit, a parked regeneration request is triggered, and engine thermal management and injection regeneration are performed under stable operating conditions to raise the exhaust gas temperature to 550 °C. After a certain period of time, the regeneration is completed, maintaining a high regeneration effect.

[0052] A vehicle is proposed below, including: an engine; the aftertreatment system proposed in this application, the aftertreatment system is located downstream of the exhaust gas outlet of the engine; a controller, the controller is communicatively connected to the aftertreatment system, and the controller is used to control the aftertreatment system to execute the control method of the aftertreatment system proposed in this application.

[0053] Figure 3 is a schematic structural diagram of the control of a post-treatment system provided by an exemplary embodiment of the present application. As Figure 3 shown, the control device 3 of the post-treatment system includes: a first calculation module 31 configured to calculate the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the inlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the first nitrogen oxide treatment device, and the space velocity of the first nitrogen oxide treatment device; a first adjustment module 32 configured to adjust the urea injection amount sprayed into the first nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the first nitrogen oxide treatment device, and a preset nitrogen oxide ratio emission; a second calculation module 33 configured to calculate the ratio of nitrogen dioxide to nitrogen oxides output by the particulate matter treatment device according to the temperature before the inlet end of the particulate matter treatment device, the temperature before the inlet end of the second nitrogen oxide treatment device, and the space velocity of the particulate matter treatment device; a third calculation module 34 configured to calculate the urea injection amount of the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the inlet end of the second nitrogen oxide treatment device, and the ratio of nitrogen dioxide to nitrogen oxides output by the particulate matter treatment device; a second adjustment module 35 configured to adjust the urea injection amount sprayed into the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and a second preset nitrogen oxide ratio emission.

[0054] The control device of the post-treatment system provided by the present application realizes the reduction of nitrogen oxides and the oxidation and removal of ammonia by arranging a multifunctional catalyst in the first nitrogen oxide treatment device and combining the urea sprayed by the urea nozzle. In the particulate matter treatment device, a multifunctional catalyst is arranged to capture particulate matter and catalytically generate nitrogen dioxide. In the second nitrogen oxide treatment device, the urea sprayed by the urea nozzle is combined to reduce nitrogen oxides and perform ammonia oxidation and removal. Through the design of the multifunctional catalyst, the post-treatment installation space can be kept basically unchanged. Moreover, on this basis, by monitoring the temperature with a temperature sensor and combining the nitrogen oxide concentration monitored by the nitrogen oxide sensor in each link, the injection amount of the urea nozzle can be flexibly adjusted to prevent waste of the reducing agent and reduce the possibility of secondary pollution caused by ammonia leakage after the catalyst catalysis, thereby achieving lower emissions.

[0055] In one embodiment, the first calculation module 31 may be configured to: determine the nitrogen oxide conversion efficiency of the first nitrogen oxide treatment device according to the temperature before the inlet end of the first nitrogen oxide treatment device and the space velocity of the first nitrogen oxide treatment device; calculate the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the inlet end of the first nitrogen oxide treatment device, and the nitrogen oxide conversion efficiency of the first nitrogen oxide treatment device.

[0056] In one embodiment, the first adjustment module 32 may be configured to: calculate the actual NOx specific emission of the first NOx treatment device according to the NOx concentration at the outlet end of the first NOx treatment device and the exhaust gas data; when the actual NOx specific emission of the first NOx treatment device exceeds the emission range of the first preset NOx specific emission, adjust the urea injection amount of the first NOx treatment device based on the deviation value between the actual NOx specific emission and the first preset NOx specific emission of the first NOx treatment device.

[0057] In one embodiment, the second calculation module 33 may be configured to: obtain a weighted temperature value according to the temperature before the inlet end of the particulate matter treatment device and the temperature before the inlet end of the second NOx treatment device; determine the ratio of preset nitrogen dioxide to NOx according to the weighted temperature value and the space velocity of the particulate matter treatment device; calculate the ratio of nitrogen dioxide to NOx output by the particulate matter treatment device based on the NOx concentration at the outlet end of the first NOx treatment device and the ratio of preset nitrogen dioxide to NOx.

[0058] In one embodiment, the second adjustment module 35 may be configured to: calculate the actual NOx specific emission of the second NOx treatment device according to the NOx concentration at the outlet end of the second NOx treatment device and the exhaust gas data; when the actual NOx specific emission of the second NOx treatment device exceeds the emission range of the second preset NOx specific emission, adjust the urea injection amount of the second NOx treatment device based on the deviation value between the actual NOx specific emission and the second preset NOx specific emission of the second NOx treatment device.

[0059] In one embodiment, the control device of the aftertreatment system may also be configured to: calculate the carbon loading according to the first pressure difference of the particulate matter treatment device and the exhaust gas data; wherein, the first pressure difference represents the pressure difference between the inlet end and the outlet end of the particulate matter treatment device; when the carbon loading is greater than or equal to the first limit value, adjust the urea injection amount and the temperature; when the carbon loading is greater than or equal to the second limit value, trigger a parked regeneration request; wherein, the second limit value is greater than the first limit value.

[0060] The method in this application can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in this application are executed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, a core network device, an OAM, or other programmable devices.

[0061] The computer program product may be written in any combination of one or more programming languages for programming code to perform the operations of the embodiments of the present application. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The programming code may be executed entirely on the user's computing device, partially on the user's device, executed as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0062] The computer program or instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center integrating one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it may also be an optical medium, such as a digital video disc; or it may be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both volatile and non-volatile types of storage media.

[0063] In addition, an embodiment of the present application may also be a storage medium having a computer program stored thereon, and the computer program is executed by a processor to perform the steps in the control method of a post-processing system described in any of the above embodiments of this specification: For the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described order of actions, because according to the present application, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0064] It should be noted that the embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments may be referred to each other. For the device embodiments, since they are basically similar to the method embodiments, they are described relatively simply, and the relevant parts may refer to the partial description of the method embodiments.

[0065] The steps in the methods of the embodiments of the present application can be adjusted, combined, and deleted according to actual needs. The technical features described in the embodiments can be replaced or combined. The devices in the embodiments of the present application can be combined, divided, and deleted according to actual needs.

[0066] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0067] The steps of the methods or algorithms described in combination with the embodiments disclosed herein can be directly implemented by hardware, software units executed by a processor, or a combination of the two. The software units can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0068] Finally, it should be noted that in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article, or device including the said element.

[0069] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A post-processing system, characterized in that, Including: A first nitrogen oxide treatment device, which is located downstream of the exhaust gas outlet of the engine, and is used to reduce nitrogen oxides and carry out ammonia oxidation and removal; A particulate matter treatment device, which is located downstream of the first nitrogen oxide treatment device, and is used to capture particulate matter and catalytically generate nitrogen dioxide; A second nitrogen oxide treatment device, which is located downstream of the particulate matter treatment device, and is used to reduce nitrogen oxides and carry out ammonia oxidation and removal; A urea nozzle, which is used to inject urea into the first nitrogen oxide treatment device and the second nitrogen oxide treatment device; A temperature sensor, which is used to detect the temperature before the intake end of the first nitrogen oxide treatment device, the temperature before the intake end of the particulate matter treatment device, and the temperature before the intake end of the second nitrogen oxide treatment device; A nitrogen oxide sensor, which is used to detect the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, and the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device.

2. The post-processing system according to claim 1, wherein The first nitrogen oxide treatment device is coated with a selective catalytic reduction catalyst and an ammonia slip catalyst, and the second nitrogen oxide treatment device is coated with a selective catalytic reduction catalyst and an ammonia slip catalyst.

3. The post-treatment system according to claim 1, characterized in that, The particulate matter treatment device is coated with a catalyst of an oxidation catalytic converter formulation and a catalyst of a particulate matter trap formulation.

4. A control method for a post-processing system, characterized in that, Applied to the aftertreatment system according to any one of claims 1-3 above, the control method of the aftertreatment system includes: Calculating the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, the temperature before the intake end of the first nitrogen oxide treatment device, and the space velocity of the first nitrogen oxide treatment device; Adjusting the urea injection amount injected into the first nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the intake end of the first nitrogen oxide treatment device, and the preset nitrogen oxide specific emission; Calculating the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device according to the temperature before the intake end of the particulate matter treatment device, the temperature before the intake end of the second nitrogen oxide treatment device, and the space velocity of the particulate matter treatment device; Calculating the urea injection amount of the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the intake end of the second nitrogen oxide treatment device, and the ratio of nitrogen dioxide and nitrogen oxides output by the particulate matter treatment device; Adjusting the urea injection amount injected into the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and the second preset nitrogen oxide specific emission.

5. The control method of the post-processing system according to claim 4, wherein Calculate the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, the temperature before the intake end of the first nitrogen oxide treatment device, and the space velocity of the first nitrogen oxide treatment device, including: Determine the nitrogen oxide conversion efficiency of the first nitrogen oxide treatment device according to the temperature before the intake end of the first nitrogen oxide treatment device and the space velocity of the first nitrogen oxide treatment device; Calculate the urea injection amount of the first nitrogen oxide treatment device according to the exhaust gas data, the nitrogen oxide concentration at the intake end of the first nitrogen oxide treatment device, and the nitrogen oxide conversion efficiency of the first nitrogen oxide treatment device.

6. The control method of the post-treatment system according to claim 4, characterized in that, Adjust the urea injection amount sprayed into the first nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device, the temperature before the intake end of the first nitrogen oxide treatment device, and the preset nitrogen oxide specific emission, including: Calculate the actual nitrogen oxide specific emission of the first nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device and the exhaust gas data; When the actual nitrogen oxide specific emission of the first nitrogen oxide treatment device exceeds the emission range of the first preset nitrogen oxide specific emission, adjust the urea injection amount of the first nitrogen oxide treatment device based on the deviation value between the actual nitrogen oxide specific emission of the first nitrogen oxide treatment device and the first preset nitrogen oxide specific emission.

7. The control method of the post-treatment system according to claim 4, characterized in that, Calculate the ratio of nitrogen dioxide to nitrogen oxides output by the particulate matter treatment device according to the temperature before the intake end of the particulate matter treatment device, the temperature before the intake end of the second nitrogen oxide treatment device, and the space velocity of the particulate matter treatment device, including: Obtain a weighted temperature value according to the temperature before the intake end of the particulate matter treatment device and the temperature before the intake end of the second nitrogen oxide treatment device; Determine the preset ratio of nitrogen dioxide to nitrogen oxides according to the weighted temperature value and the space velocity of the particulate matter treatment device; Calculate the ratio of nitrogen dioxide to nitrogen oxides output by the particulate matter treatment device based on the nitrogen oxide concentration at the outlet end of the first nitrogen oxide treatment device and the preset ratio of nitrogen dioxide to nitrogen oxides.

8. The control method of the post-treatment system according to claim 4, characterized in that, Adjust the urea injection amount sprayed into the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and the second preset nitrogen oxide specific emission, including: Calculate the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device according to the nitrogen oxide concentration at the outlet end of the second nitrogen oxide treatment device and the exhaust gas data; When the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device exceeds the emission range of the second preset nitrogen oxide specific emission, adjust the urea injection amount of the second nitrogen oxide treatment device based on the deviation value between the actual nitrogen oxide specific emission of the second nitrogen oxide treatment device and the second preset nitrogen oxide specific emission.

9. The control method of the post-treatment system according to claim 4, characterized in that, The control method of the after-treatment system further includes: Calculate the carbon loading based on the first differential pressure of the particulate matter treatment device and the exhaust gas data; wherein, the first differential pressure represents the differential pressure between the inlet end and the outlet end of the particulate matter treatment device; When the carbon loading is greater than or equal to the first limit value, adjust the urea injection amount and temperature; When the carbon loading is greater than or equal to the second limit value, trigger a parked regeneration request; Wherein, the second limit value is greater than the first limit value.

10. A vehicle, characterized in that, Comprising: An engine; A post-treatment system as described in any one of claims 1-3 above, the post-treatment system being located downstream of the exhaust gas outlet of the engine; A controller, the controller being communicatively connected to the post-treatment system, the controller being configured to control the post-treatment system to execute the control method of the post-treatment system as described in any one of claims 4-9 above.

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