Reaction control method, device, system and storage medium of dual-stage SCR system

Abstract

The present invention discloses a reaction control method, device, system and storage medium of a two-stage SCR system. The reaction control method of the two-stage SCR system includes: obtaining the first-stage SCR inlet temperature of the first-stage SCR system in real time; obtaining the second-stage SCR inlet temperature of the second-stage SCR system in real time; determining the SCR cooperative control state based on the first-stage SCR inlet temperature and the second-stage SCR inlet temperature, the SCR cooperative control state includes the first-stage SCR system activation, the second-stage SCR system activation, the first-stage SCR system and the second-stage SCR system are both activated, and the first-stage SCR system and the second-stage SCR system are not activated; determining the first-stage SCR required urea amount of the first-stage SCR system and the second-stage SCR required urea amount of the second-stage SCR system based on the SCR cooperative control state; driving the first-stage SCR urea nozzle to spray urea based on the first-stage SCR required urea amount; driving the second-stage SCR urea nozzle to spray urea based on the second-stage SCR required urea amount. By adopting the above scheme, the problem of being unable to continuously adjust the urea injection amount is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine post-processing, and in particular to a reaction control method, device, system and storage medium of a dual-stage SCR system. Background Art

[0002] With the gradual implementation of emission regulations, air pollutants from mobile sources have been effectively controlled. However, the control of pollutants from mobile sources has not come to an end and there is still room for further reduction.

[0003] At present, domestic OEMs generally adopt the "DOC+DPF+SCR+ASC" technology route to treat pollutants in automobile exhaust, that is, diesel oxidation catalyst + diesel particulate filter + selective catalytic reduction + ammonia oxidation catalyst. In order to make the treatment of pollutants in automobile exhaust more effective, the two-stage SCR system has become the mainstream technology route. The typical configuration of the two-stage SCR system is as follows: Figure 1 As shown, it usually includes a primary DOC carrier, a primary SCR carrier, a primary ASC carrier, a secondary DOC carrier, a DPF carrier, a secondary SCR carrier, and a secondary ASC carrier which are arranged in sequence from the engine outlet.

[0004] In order to optimize the efficiency of the two-stage SCR system and meet the emission requirements, the Chinese invention patent CN116104617B after the authorization announcement discloses a control method, device and SCR system for SCR efficiency, which can correct the urea injection rate according to the observation results of the front-stage SCR and the rear-stage SCR efficiency over a period of time, so that the urea injection amount changes, but this solution has no way to achieve continuous adjustment of the urea injection amount, and the efficiency of the two-stage SCR system still has room for improvement. Summary of the invention

[0005] The present invention provides a reaction control method, device, system and storage medium of a two-stage SCR system, so as to solve the problem that the urea injection amount cannot be continuously adjusted and the efficiency of the two-stage SCR system cannot be improved.

[0006] According to one aspect of the present invention, a reaction control method of a two-stage SCR system is provided, the reaction control method of the two-stage SCR system comprising:

[0007] Real-time acquisition of the primary SCR inlet temperature of the primary SCR system;

[0008] Real-time acquisition of the secondary SCR inlet temperature of the secondary SCR system;

[0009] Determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, the SCR cooperative control state including primary SCR system activation, secondary SCR system activation, both the primary SCR system and the secondary SCR system activation, and both the primary SCR system and the secondary SCR system inactivation;

[0010] Determining a primary SCR required urea amount of the primary SCR system and a secondary SCR required urea amount of the secondary SCR system based on the SCR cooperative control state;

[0011] driving a first-stage SCR urea nozzle to spray urea based on a urea amount required by the first-stage SCR;

[0012] The secondary SCR urea nozzle is driven to spray urea based on the secondary SCR required urea amount.

[0013] In an optional embodiment of the present invention, the determining the primary SCR required urea amount of the primary SCR system and the secondary SCR required urea amount of the secondary SCR system based on the SCR cooperative control state includes:

[0014] Determining a primary SCR target weight of the primary SCR system and a secondary SCR target weight of the secondary SCR system based on the SCR cooperative control state;

[0015] Determining a primary SCR required urea amount based on the primary SCR target weight;

[0016] The secondary SCR required urea amount is determined based on the secondary SCR target weight.

[0017] In an optional embodiment of the present invention, determining the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the SCR cooperative control state includes:

[0018] When the SCR cooperative control state is that the primary SCR system is activated, determining that the primary SCR target weight of the primary SCR system is 100% and the secondary SCR target weight of the secondary SCR system is 0%;

[0019] When the SCR cooperative control state is that the secondary SCR system is activated, determining that the secondary SCR target weight of the secondary SCR system is 100% and the primary SCR target weight of the primary SCR system is 0%;

[0020] When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated, determining the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system, and determining the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the primary actual reaction efficiency and / or the secondary actual reaction efficiency, wherein the sum of the primary SCR target weight and the secondary SCR target weight is 100%;

[0021] When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive, it is determined that the primary SCR target weight of the primary SCR system is 0% and the secondary SCR target weight of the secondary SCR system is 0%.

[0022] In an optional embodiment of the present invention, determining the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system includes:

[0023] Obtaining a primary NOx outlet concentration at an outlet of the primary SCR system;

[0024] Determining the primary actual reaction efficiency of the primary SCR system based on the original NOx emission concentration and the primary NOx outlet concentration;

[0025] Obtaining a secondary NOx outlet concentration at an outlet of the secondary SCR system;

[0026] A secondary actual reaction efficiency of the secondary SCR system is determined based on the primary NOx outlet concentration and the secondary NOx outlet concentration.

[0027] In an optional embodiment of the present invention, the secondary actual reaction efficiency of the secondary SCR system is negatively correlated with the primary SCR target weight;

[0028] And / or, the primary actual reaction efficiency of the primary SCR system is positively correlated with the primary SCR target weight.

[0029] In an optional embodiment of the present invention, determining the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the primary actual reaction efficiency and / or the secondary actual reaction efficiency includes:

[0030] Determining the secondary NOx capacity mass flow rate that the secondary SCR system can process based on the secondary actual reaction efficiency of the secondary SCR system;

[0031] Obtain the original NOx emission mass flow rate;

[0032] Determining a primary NOx target mass flow rate of the primary SCR system based on a difference between the original NOx exhaust mass flow rate and the secondary NOx capacity mass flow rate;

[0033] Determining the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate;

[0034] The secondary SCR target weight is determined based on a difference between 100% and the primary SCR target weight.

[0035] In an optional embodiment of the present invention, determining the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate includes:

[0036] Determine whether the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate exceeds a preset primary weight range, wherein the preset primary weight range includes a primary SCR weight upper limit value and a primary SCR weight lower limit value;

[0037] When the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate is greater than the primary weight upper limit value, the primary SCR target weight is set to the primary SCR weight upper limit value;

[0038] When the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate is less than the primary weighted SCR lower limit value, the primary SCR target weight is set to the primary weighted SCR lower limit value;

[0039] When the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate does not exceed the preset first-level weight range, the first-level SCR target weight is set to the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate.

[0040] In an optional embodiment of the present invention, the step of determining the primary SCR required urea amount based on the primary SCR target weight includes:

[0041] determining whether the primary SCR target weight is 0%;

[0042] If the primary SCR target weight is 0%, the primary SCR required urea amount is determined to be 0;

[0043] If the primary SCR target weight is not 0%, determining whether the primary SCR target weight is 100%;

[0044] If the primary SCR target weight is 100%, the original NOx emission concentration and the exhaust flow rate are obtained, the primary SCR open-loop ammonia nitrogen ratio is determined based on the original NOx emission concentration, the primary SCR inlet temperature and the exhaust flow rate, the primary target reaction efficiency of the primary SCR system is determined based on the original NOx emission concentration and the exhaust flow rate, the primary SCR open-loop ammonia nitrogen ratio is corrected based on the primary target reaction efficiency and the primary actual reaction efficiency to obtain the primary SCR current ammonia nitrogen ratio, and the primary SCR required urea amount is calculated based on the primary SCR current ammonia nitrogen ratio;

[0045] If the first-level SCR target weight is not 100%, obtain the original NOx emission concentration and the exhaust flow rate, determine the first-level NOx treatment concentration based on the original NOx emission concentration and the first-level SCR target weight, determine the first-level SCR current ammonia nitrogen ratio of the first-level SCR system based on the first-level NOx treatment concentration, the first-level SCR inlet temperature and the exhaust flow rate, and calculate the first-level SCR required urea amount based on the first-level SCR current ammonia nitrogen ratio.

[0046] In an optional embodiment of the present invention, the correcting the primary SCR open-loop ammonia nitrogen ratio based on the primary target reaction efficiency and the primary actual reaction efficiency to obtain the primary SCR current ammonia nitrogen ratio includes:

[0047] Determining whether a primary efficiency deviation between the primary target reaction efficiency and the primary actual reaction efficiency is less than a preset deviation threshold;

[0048] If the primary efficiency deviation is less than the preset deviation threshold, the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio;

[0049] If the primary efficiency deviation is not less than the preset deviation threshold, the primary corrected ammonia nitrogen ratio is determined based on the primary efficiency deviation, and the sum of the primary corrected ammonia nitrogen ratio and the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio.

[0050] In an optional embodiment of the present invention, determining the secondary SCR required urea amount based on the secondary SCR target weight includes:

[0051] determining whether the secondary SCR target weight is 0%;

[0052] If so, determine that the amount of urea required by the secondary SCR is 0;

[0053] If not, obtain the secondary SCR inlet NOx concentration and exhaust flow rate at the secondary SCR system inlet, determine the secondary SCR open-loop ammonia nitrogen ratio based on the secondary SCR inlet NOx concentration, the secondary SCR inlet temperature and the exhaust flow rate, determine the secondary target reaction efficiency of the secondary SCR system based on the secondary SCR inlet NOx concentration and the exhaust flow rate, correct the secondary SCR open-loop ammonia nitrogen ratio based on the secondary target reaction efficiency and the secondary actual reaction efficiency to obtain the secondary SCR current ammonia nitrogen ratio, and calculate the secondary SCR required urea amount based on the secondary SCR current ammonia nitrogen ratio.

[0054] In an optional embodiment of the present invention, the SCR cooperative control state is determined based on the primary SCR inlet temperature and the secondary SCR inlet temperature, and the SCR cooperative control state includes the primary SCR system being activated, the secondary SCR system being activated, both the primary SCR system and the secondary SCR system being activated, and both the primary SCR system and the secondary SCR system being inactivated, including:

[0055] Determining whether the primary SCR inlet temperature is greater than a preset start-up temperature threshold and determining whether the secondary SCR inlet temperature is greater than the preset start-up temperature threshold;

[0056] When the first-stage SCR inlet temperature is greater than a preset start-up temperature threshold and the second-stage SCR inlet temperature is less than or equal to the preset start-up temperature threshold, determining that the SCR cooperative control state is the first-stage SCR system activation;

[0057] When the primary SCR inlet temperature is less than or equal to a preset start-up temperature threshold and the secondary SCR inlet temperature is greater than the preset start-up temperature threshold, determining that the SCR cooperative control state is a secondary SCR system activation;

[0058] When the primary SCR inlet temperature and the secondary SCR inlet temperature are both greater than a preset injection start temperature threshold, determining that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated;

[0059] When the primary SCR inlet temperature and the secondary SCR inlet temperature are both less than or equal to a preset injection start temperature threshold, it is determined that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive.

[0060] In an optional embodiment of the present invention, after determining the SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, the method further includes:

[0061] An SCR exhaust temperature management mode is determined based on the SCR cooperative control state, and the SCR exhaust temperature management mode includes a strong thermal management mode, a weak thermal management mode and a no thermal management mode, wherein the strong thermal management mode and the weak thermal management mode are used to increase the inlet temperature of the first-level SCR system, and the temperature raising efficiency of the strong thermal management mode is greater than the temperature raising efficiency of the weak thermal management mode.

[0062] In an optional embodiment of the present invention, the SCR exhaust temperature management mode is determined based on the SCR cooperative control state, and the SCR exhaust temperature management mode includes a strong thermal management mode, a weak thermal management mode and a non-thermal management mode, including:

[0063] When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive, determining that the SCR exhaust temperature management mode is a strong thermal management mode;

[0064] When the SCR cooperative control state is that the first-level SCR system is activated or the second-level SCR system is activated, determining that the SCR exhaust temperature management mode is a weak thermal management mode;

[0065] When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated, it is determined that the SCR exhaust temperature management mode is a non-thermal management mode.

[0066] According to another aspect of the present invention, a reaction control device of a two-stage SCR system is provided, the reaction control device of the two-stage SCR system comprising:

[0067] The primary temperature acquisition module is used to obtain the primary SCR inlet temperature of the primary SCR system in real time;

[0068] A secondary temperature acquisition module is used to obtain the secondary SCR inlet temperature of the secondary SCR system in real time;

[0069] a cooperative control determination module, configured to determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, wherein the SCR cooperative control state includes an activated primary SCR system, an activated secondary SCR system, both the primary SCR system and the secondary SCR system are activated, and both the primary SCR system and the secondary SCR system are inactivated;

[0070] a urea requirement determination module, configured to determine a primary SCR urea requirement amount of the primary SCR system and a secondary SCR urea requirement amount of the secondary SCR system based on the SCR cooperative control state;

[0071] A primary driving module, used for driving a primary SCR urea nozzle to spray urea based on a urea amount required by the primary SCR;

[0072] The secondary driving module is used to drive the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount.

[0073] According to another aspect of the present invention, a reaction control system of a dual-stage SCR system is provided, the reaction control system of the dual-stage SCR system comprising:

[0074] at least one processor; and

[0075] a memory communicatively connected to the at least one processor; wherein,

[0076] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the reaction control method of the dual-stage SCR system according to any embodiment of the present invention.

[0077] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the reaction control method of the dual-stage SCR system described in any embodiment of the present invention when executed.

[0078] The technical solution of the embodiment of the present invention obtains the first-level SCR inlet temperature of the first-level SCR system and the second-level SCR inlet temperature of the second-level SCR system in real time, then determines the SCR cooperative control state based on the first-level SCR inlet temperature and the second-level SCR inlet temperature, then determines the first-level SCR required urea amount of the first-level SCR system and the second-level SCR required urea amount of the second-level SCR system based on the SCR cooperative control state, and finally drives the first-level SCR urea nozzle to spray urea based on the first-level SCR required urea amount and drives the second-level SCR urea nozzle to spray urea based on the second-level SCR required urea amount. Since the first-level SCR inlet temperature and the second-level SCR inlet temperature are obtained in real time, the first-level SCR required urea amount and the second-level SCR required urea amount can be continuously calculated, and then the urea amount sprayed by the first-level SCR urea nozzle and the second-level SCR urea nozzle can be continuously adjusted, thereby solving the problem of being unable to continuously adjust the urea injection amount and improving the efficiency of the two-stage SCR system.

[0079] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0081] Figure 1 It is a structural schematic diagram of a two-stage SCR system in the related art;

[0082] Figure 2 A flow chart of a reaction control method for a dual-stage SCR system provided in Embodiment 1 of the present invention;

[0083] Figure 3 is a curve diagram showing the relationship between the activation states of the primary SCR system and the secondary SCR system and the primary SCR inlet temperature and the secondary SCR inlet temperature;

[0084] Figure 4 A flow chart of a reaction control method for a dual-stage SCR system provided in Embodiment 2 of the present invention;

[0085] Figure 5 A flow chart of a reaction control method for a dual-stage SCR system provided in Embodiment 3 of the present invention;

[0086] Figure 6 A flow chart for determining the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system;

[0087] Figure 7 A flowchart of the step of determining the primary SCR required urea amount based on the primary SCR target weight;

[0088] Figure 8 A flowchart of the step of determining the secondary SCR required urea amount based on the secondary SCR target weight;

[0089] Fig. 9 A schematic structural diagram of a reaction control device for a dual-stage SCR system provided in a fourth embodiment of the present invention;

[0090] Fig.10 It is a structural schematic diagram of a reaction control system of a two-stage SCR system for implementing a reaction control method of a two-stage SCR system according to an embodiment of the present invention.

[0091] Among them: 1. Engine; 2. Primary DOC carrier; 3. Primary SCR carrier; 4. Primary ASC carrier; 5. Secondary DOC carrier; 6. DPF carrier; 7. Secondary SCR carrier; 8. Secondary ASC carrier; 9. Upstream NOx sensor; 10. Midstream NOx sensor; 20. Downstream NOx sensor; 30. Primary SCR front temperature sensor; 40. Primary SCR rear temperature sensor; 50. Secondary SCR front temperature sensor; 60. Secondary SCR rear temperature sensor; 70. Primary SCR urea nozzle; 80. Secondary SCR urea nozzle; 41. Primary temperature acquisition module; 42. Secondary temperature acquisition module; 43. Coordination determination module; 44. Urea demand determination module; 45. Primary drive module; 46. Secondary drive module. DETAILED DESCRIPTION

[0092] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0093] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0094] Typical configurations of dual-stage SCR systems in related technologies are as follows: Figure 1As shown, it usually includes a primary DOC carrier 2, a primary SCR carrier 3, a primary ASC carrier 4, a secondary DOC carrier 5, a DPF carrier 6, a secondary SCR carrier 7, and a secondary ASC carrier 8 which are arranged in sequence from the outlet of the engine 1. The dual-stage SCR system includes two SCR systems, namely the primary SCR system and the secondary SCR system. The primary DOC carrier 2, the primary SCR carrier 3, and the primary ASC carrier 4 usually belong to the primary SCR system, and the secondary DOC carrier 5, the DPF carrier 6, the secondary SCR carrier 7, and the secondary ASC carrier 8 usually belong to the secondary SCR system. Through the two SCR systems, the treatment of pollutants in automobile exhaust is more effective.

[0095] The two-stage SCR system also includes an upstream NOx sensor 9, a midstream NOx sensor 10, and a downstream NOx sensor 20. NOx is a general term for a mixture of nitrogen monoxide (NO) and nitrogen dioxide (NO2) in the exhaust of the engine 1, and is the main exhaust pollutant of the diesel engine; the upstream NOx sensor 9 is arranged on the pipeline between the engine 1 and the first-stage DOC carrier 2, and is used to measure the original NOx concentration of the engine 1. The midstream NOx sensor 10 is arranged on the pipeline between the first-stage ASC carrier 4 and the second-stage DOC carrier 5, and is used to measure the NOx concentration at the inlet of the second-stage SCR, which is also the NOx concentration at the outlet of the first-stage SCR. The downstream NOx sensor 20 is arranged on the pipeline after the second-stage ASC carrier 8, and is used to measure the NOx concentration at the outlet of the second-stage SCR.

[0096] The two-stage SCR system also includes a first-stage SCR front temperature sensor 30, a first-stage SCR rear temperature sensor 40, a second-stage SCR front temperature sensor 50, and a second-stage SCR rear temperature sensor 60. The first-stage SCR front temperature sensor 30 is arranged on the pipeline between the first-stage SCR carrier 3 and the first-stage DOC carrier 2, and is used to measure the first-stage SCR inlet temperature; the first-stage SCR rear temperature sensor 40 is arranged on the pipeline between the first-stage ASC carrier 4 and the second-stage DOC carrier 5, and is used to measure the first-stage SCR outlet temperature; the second-stage SCR front temperature sensor 50 is arranged on the pipeline between the DPF carrier 6 and the second-stage SCR carrier 7, and is used to measure the second-stage SCR inlet temperature; the second-stage SCR rear temperature sensor 60 is arranged on the pipeline after the second-stage ASC carrier 8, and is used to measure the second-stage SCR outlet temperature.

[0097] The two-stage SCR system further includes a primary SCR urea nozzle 70 and a secondary SCR urea nozzle 80. The primary SCR urea nozzle 70 is arranged on the pipeline between the primary SCR carrier 3 and the primary DOC carrier 2. The primary SCR urea nozzle 70 is used to inject a certain amount of urea into the pipeline connected to the primary SCR carrier 3. The urea is pyrolyzed and hydrolyzed to produce ammonia gas, a reducing agent for SCR reaction. Under the catalytic action of the primary SCR carrier 3, the urea undergoes an SCR reaction with the NOx pollutants in the exhaust gas, reducing the NOx to harmless nitrogen, thereby achieving the function of reducing NOx. The secondary SCR urea nozzle 80 is arranged on the pipeline between the DPF carrier 6 and the secondary SCR carrier 7. The secondary SCR urea nozzle 80 is used to inject a certain amount of urea into the exhaust pipeline connected to the secondary SCR carrier 7. The urea is pyrolyzed and hydrolyzed to produce ammonia gas, a reducing agent for SCR reaction. Under the catalytic action of the primary SCR carrier 3, the urea undergoes an SCR reaction with the NOx pollutants in the exhaust gas, reducing the NOx to harmless nitrogen, thereby achieving the function of further reducing NOx.

[0098] Embodiment 1

[0099] Figure 2 This is a flow chart of a reaction control method of a two-stage SCR system provided in the first embodiment of the present invention. This embodiment is applicable to a two-stage SCR system. The reaction control method of the two-stage SCR system can be executed by a reaction control device of the two-stage SCR system. The reaction control device of the two-stage SCR system can be implemented in the form of hardware and / or software. The reaction control device of the two-stage SCR system can be configured in an engine management system. Figure 2 As shown, the reaction control method of the dual-stage SCR system includes:

[0100] S110 , obtaining a first-stage SCR inlet temperature of a first-stage SCR system in real time.

[0101] The first-stage SCR inlet temperature is the temperature value at the inlet of the first-stage SCR system. In a specific embodiment, the temperature value detected by the first-stage SCR pre-temperature sensor can be obtained as the first-stage SCR inlet temperature by communicating with the first-stage SCR pre-temperature sensor.

[0102] S120 . Acquire the secondary SCR inlet temperature of the secondary SCR system in real time.

[0103] The secondary SCR inlet temperature is the temperature value at the inlet of the secondary SCR system. In a specific embodiment, the temperature value detected by the secondary SCR pre-temperature sensor can be obtained as the secondary SCR inlet temperature by communicating with the secondary SCR pre-temperature sensor.

[0104] S130. Determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, wherein the SCR cooperative control state includes the primary SCR system being activated, the secondary SCR system being activated, both the primary SCR system and the secondary SCR system being activated, and both the primary SCR system and the secondary SCR system being inactivated.

[0105] Among them, the activation of the primary SCR system means that only the primary SCR system is in working state, and at this time, only the primary SCR system is used to process the NOx pollutants in the exhaust gas; the activation of the secondary SCR system means that only the secondary SCR system is in working state, and at this time, only the secondary SCR system is used to process the NOx pollutants in the exhaust gas; the activation of both the primary SCR system and the secondary SCR system means that both the primary SCR system and the secondary SCR system are in working state, and at this time, the primary SCR system and the secondary SCR system are used to process the NOx pollutants in the exhaust gas together; the inactivation of both the primary SCR system and the secondary SCR system means that at this time, neither the primary SCR system nor the secondary SCR system is in working state. Both the primary SCR system and the secondary SCR system process the NOx pollutants in the exhaust gas through the SCR reaction. When the temperature is too low, the reaction efficiency of the SCR reaction decreases. In order to improve the overall reaction efficiency of the two-stage SCR system, it is necessary to adjust the working state of the primary SCR system and the secondary SCR system according to the primary SCR inlet temperature and the secondary SCR inlet temperature.

[0106] S140 . Determine a primary SCR required urea amount of the primary SCR system and a secondary SCR required urea amount of the secondary SCR system based on the SCR cooperative control state.

[0107] Among them, the amount of urea required by the primary SCR refers to the amount of urea that the primary SCR system needs to spray in order to make the treated exhaust pollutants meet the standards; the amount of urea required by the secondary SCR refers to the amount of urea that the secondary SCR system needs to spray in order to make the treated exhaust pollutants meet the standards. When the working states of the primary SCR system and the secondary SCR system are different, the amount of urea that the primary SCR system and the secondary SCR system need to spray will also be different. For example, when only the primary SCR system is in working state, the NOx pollutants in the exhaust gas need to be processed by the primary SCR system, so the primary SCR system needs to spray more urea, while the secondary SCR system does not spray urea at this time; when both the primary SCR system and the secondary SCR system are working, both the primary SCR system and the secondary SCR system need to spray urea, so it is necessary to determine the primary SCR urea required by the primary SCR system and the secondary SCR urea required by the secondary SCR system according to the SCR cooperative control state.

[0108] S150 , driving the primary SCR urea nozzle to spray urea based on the primary SCR required urea amount.

[0109] The first-stage SCR urea nozzle refers to a nozzle for spraying urea in the first-stage SCR system. Therefore, after the first-stage SCR required urea amount is calculated, the first-stage SCR urea nozzle is driven to spray urea of ​​the first-stage SCR required urea amount.

[0110] S160 , driving the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount.

[0111] The secondary SCR urea nozzle refers to a nozzle for spraying urea in the secondary SCR system, so after the secondary SCR required urea amount is calculated, the secondary SCR urea nozzle is driven to spray urea of ​​the secondary SCR required urea amount.

[0112] The above scheme obtains the first-level SCR inlet temperature of the first-level SCR system and the second-level SCR inlet temperature of the second-level SCR system in real time, and then determines the SCR cooperative control state based on the first-level SCR inlet temperature and the second-level SCR inlet temperature, and then determines the first-level SCR required urea amount of the first-level SCR system and the second-level SCR required urea amount of the second-level SCR system based on the SCR cooperative control state, and finally drives the first-level SCR urea nozzle to spray urea based on the first-level SCR required urea amount and drives the second-level SCR urea nozzle to spray urea based on the second-level SCR required urea amount. Since the first-level SCR inlet temperature and the second-level SCR inlet temperature are obtained in real time, the first-level SCR required urea amount and the second-level SCR required urea amount can be continuously calculated, and then the urea amount sprayed by the first-level SCR urea nozzle and the second-level SCR urea nozzle can be continuously adjusted, thereby solving the problem of being unable to continuously adjust the urea injection amount and improving the efficiency of the two-stage SCR system.

[0113] In an optional embodiment of the present invention, the SCR cooperative control state is determined based on the primary SCR inlet temperature and the secondary SCR inlet temperature, and the SCR cooperative control state includes the primary SCR system being activated, the secondary SCR system being activated, both the primary SCR system and the secondary SCR system being activated, and both the primary SCR system and the secondary SCR system being inactivated, including:

[0114] Determine whether the first-stage SCR inlet temperature is greater than the preset start-up temperature threshold and determine whether the second-stage SCR inlet temperature is greater than the preset start-up temperature threshold. The preset start-up temperature threshold refers to the temperature value that needs to be reached at the entrance of the first-stage SCR system and the second-stage SCR system in the working state. In a specific embodiment, the preset start-up temperature threshold is between 150°C and 250°C, and preferably, the preset start-up temperature threshold is 200°C.

[0115] When the first-stage SCR inlet temperature is greater than a preset start-up temperature threshold and the second-stage SCR inlet temperature is less than or equal to the preset start-up temperature threshold, it is determined that the SCR cooperative control state is the first-stage SCR system activation.

[0116] When the primary SCR inlet temperature is less than or equal to a preset start-up temperature threshold and the secondary SCR inlet temperature is greater than the preset start-up temperature threshold, it is determined that the SCR cooperative control state is the secondary SCR system activation.

[0117] When the primary SCR inlet temperature and the secondary SCR inlet temperature are both greater than a preset injection start temperature threshold, it is determined that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated.

[0118] When the primary SCR inlet temperature and the secondary SCR inlet temperature are both less than or equal to a preset injection start temperature threshold, it is determined that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive.

[0119] In a specific embodiment, Figure 3 is a curve diagram showing the relationship between the activation state of the primary SCR system and the secondary SCR system and the primary SCR inlet temperature and the secondary SCR inlet temperature, such as Figure 3 As shown, the first-stage SCR inlet temperature is yt1, the second-stage SCR inlet temperature is yt2, the preset spraying temperature threshold is T, the first-stage SCR system activation state is yj1, the second-stage SCR system activation state is yj2, the state "1" represents that the SCR system is activated, and the state "0" represents that the SCR system is not activated. It can be seen that when yt1>T and yt2≤T, yj1 is in the activated state and yj2 is in the inactivated state. At this time, the SCR cooperative control state is that the first-stage SCR system is activated; at yt1 ≤T and yt2>T, yj2 is in an activated state and yj1 is in an inactivated state. At this time, the SCR co-control state is that the secondary SCR system is activated; when yt1>T and yt2>T, yj1 and yj2 are both in an activated state. At this time, the SCR co-control state is that both the primary SCR system and the secondary SCR system are activated; when yt1≤T and yt2≤T, yj1 and yj2 are both in an inactivated state. At this time, the SCR co-control state is that both the primary SCR system and the secondary SCR system are inactivated.

[0120] Embodiment 2

[0121] Figure 4 This is a flow chart of a reaction control method of a two-stage SCR system provided in the second embodiment of the present invention. The relationship between this embodiment and the above embodiment is that the first embodiment is improved. Figure 4 As shown, the reaction control method of the dual-stage SCR system includes:

[0122] S210 , obtaining the first-stage SCR inlet temperature of the first-stage SCR system in real time.

[0123] S220 . Acquire the secondary SCR inlet temperature of the secondary SCR system in real time.

[0124] S230. Determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, wherein the SCR cooperative control state includes the primary SCR system being activated, the secondary SCR system being activated, both the primary SCR system and the secondary SCR system being activated, and both the primary SCR system and the secondary SCR system being inactivated.

[0125] S240 . Determine a primary SCR target weight of the primary SCR system and a secondary SCR target weight of the secondary SCR system based on the SCR cooperative control state.

[0126] Among them, the primary SCR target weight is the percentage of the target amount of NOx reduced and treated by the primary SCR system to the total target amount of NOx that needs to be reduced and treated by the two-stage SCR system; the secondary SCR target weight is the percentage of the target amount of NOx reduced and treated by the secondary SCR system to the total target amount of NOx that needs to be reduced and treated by the two-stage SCR system. When the SCR cooperative control state is different, the working state of the primary SCR system and the secondary SCR system are different, so the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system can be determined based on the SCR cooperative control state.

[0127] S250 . Determine a primary SCR required urea amount based on the primary SCR target weight.

[0128] Among them, since the amount of urea required by the primary SCR is related to the target amount of NOx reduced by the primary SCR system, the amount of urea required by the primary SCR can be determined based on the primary SCR target weight.

[0129] S260: Determine a secondary SCR required urea amount based on the secondary SCR target weight.

[0130] Among them, since the amount of urea required by the secondary SCR is related to the target amount of NOx reduced by the secondary SCR system, the amount of urea required by the secondary SCR can be determined based on the secondary SCR target weight.

[0131] S270 , driving the primary SCR urea nozzle to spray urea based on the primary SCR required urea amount.

[0132] S280 , driving the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount.

[0133] Through the above scheme, the first-stage SCR target weight of the first-stage SCR system and the second-stage SCR target weight of the second-stage SCR system can be adjusted in real time, and then the first-stage SCR required urea amount is adjusted according to the first-stage SCR target weight, and the second-stage SCR required urea amount is adjusted according to the second-stage SCR target weight, so as to realize continuous adjustment of urea injection amount and improve the efficiency of the two-stage SCR system.

[0134] Embodiment 3

[0135] Figure 5 This is a flow chart of a reaction control method of a two-stage SCR system provided by the third embodiment of the present invention. The relationship between this embodiment and the above embodiment is that the second embodiment is improved. Figure 5 As shown, the reaction control method of the dual-stage SCR system includes:

[0136] S310 , obtaining the first-stage SCR inlet temperature of the first-stage SCR system in real time.

[0137] S320 . Acquire the secondary SCR inlet temperature of the secondary SCR system in real time.

[0138] S330. Determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, wherein the SCR cooperative control state includes the primary SCR system being activated, the secondary SCR system being activated, both the primary SCR system and the secondary SCR system being activated, and both the primary SCR system and the secondary SCR system being inactivated.

[0139] S340: When the SCR cooperative control state is that the primary SCR system is activated, determine that the primary SCR target weight of the primary SCR system is 100% and the secondary SCR target weight of the secondary SCR system is 0%.

[0140] Among them, when the SCR cooperative control state is that the primary SCR system is activated, it means that only the primary SCR system is working at this time, so the primary SCR target weight of the primary SCR system is 100% and the secondary SCR target weight of the secondary SCR system is 0%.

[0141] S350: When the SCR cooperative control state is that the secondary SCR system is activated, determine that the secondary SCR target weight of the secondary SCR system is 100% and the primary SCR target weight of the primary SCR system is 0%.

[0142] Among them, when the SCR cooperative control state is that the secondary SCR system is activated, it means that only the secondary SCR system is working at this time, so the secondary SCR target weight of the secondary SCR system is 100% and the primary SCR target weight of the primary SCR system is 0%.

[0143] S360. When the SCR co-control state is that both the primary SCR system and the secondary SCR system are activated, determine the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system, and determine the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the primary actual reaction efficiency and / or the secondary actual reaction efficiency, wherein the sum of the primary SCR target weight and the secondary SCR target weight is 100%.

[0144] The primary actual reaction efficiency refers to the ratio of the NOx concentration actually treated by the primary SCR system to the original NOx concentration, and the secondary actual reaction efficiency refers to the ratio of the NOx concentration actually treated by the secondary SCR system to the secondary NOx inlet concentration at the inlet of the secondary SCR system. The sum of the primary SCR target weight and the secondary SCR target weight is 100%, so that all NOx discharged by the engine can be treated.

[0145] The primary actual reaction efficiency and the secondary actual reaction efficiency reflect the amount of NOx that the primary SCR system and the secondary SCR system can actually process. Therefore, in order to efficiently process the NOx exhausted by the engine, the primary SCR target weight and the second target weight can be determined based on the primary actual reaction efficiency and / or the secondary actual reaction efficiency.

[0146] In an optional embodiment of the present invention, the secondary actual reaction efficiency of the secondary SCR system is negatively correlated with the primary SCR target weight, so the higher the secondary actual reaction efficiency of the secondary SCR system, the lower the primary SCR target weight, and correspondingly, the higher the secondary SCR target weight, thereby being able to efficiently process the NOx discharged by the engine.

[0147] In an optional embodiment of the present invention, the primary actual reaction efficiency of the primary SCR system is positively correlated with the primary SCR target weight. Therefore, the higher the primary actual reaction efficiency of the primary SCR system, the higher the primary SCR target weight, thereby being able to efficiently process NOx discharged from the engine.

[0148] S370: When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive, determine that the primary SCR target weight of the primary SCR system is 0% and the secondary SCR target weight of the secondary SCR system is 0%.

[0149] Among them, when the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are not activated, it means that both the primary SCR system and the secondary SCR system are not working at this time, so the secondary SCR target weight of the secondary SCR system and the primary SCR target weight of the primary SCR system are both 0%.

[0150] S380: Determine the primary SCR required urea amount based on the primary SCR target weight.

[0151] S390: Determine the secondary SCR required urea amount based on the secondary SCR target weight.

[0152] S3100: Drive the first-stage SCR urea nozzle to spray urea based on the first-stage SCR required urea amount.

[0153] S3110 , driving the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount.

[0154] The above scheme can determine the first-stage SCR target weight of the first-stage SCR system and the second-stage SCR target weight of the second-stage SCR system according to the SCR co-control state, so that the first-stage SCR target weight and the second target weight are more in line with the actual working conditions, thereby giving full play to the high robustness of the typical configuration scheme of the two-stage SCR system for NOx emissions, the effectiveness of inhibiting nitrous oxide generation and the high efficiency of urea utilization.

[0155] In an optional embodiment of the present invention, Figure 6 As shown, the determining of the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system includes:

[0156] S361. Obtain the primary NOx outlet concentration at the outlet of the primary SCR system.

[0157] The first-level NOx outlet concentration is the NOx concentration in the gas discharged by the first-level SCR system, and is also the NOx concentration at the inlet of the second-level SCR system, that is, the second-level NOx inlet concentration. Specifically, the NOx concentration value detected by the midstream NOx sensor can be obtained and used as the first-level NOx outlet concentration.

[0158] S362. Determine the primary actual reaction efficiency of the primary SCR system based on the original NOx exhaust concentration and the primary NOx outlet concentration.

[0159] Among them, the first-level actual reaction efficiency is the ratio of the concentration difference between the original NOx emission concentration and the first-level NOx outlet concentration to the original NOx emission concentration, so the first-level actual reaction efficiency of the first-level SCR system can be determined based on the original NOx emission concentration and the first-level NOx outlet concentration.

[0160] S363: Obtain the secondary NOx outlet concentration at the outlet of the secondary SCR system.

[0161] The secondary NOx outlet concentration is the NOx concentration in the gas discharged from the secondary SCR system. Specifically, the NOx concentration value detected by the downstream NOx sensor can be obtained and used as the secondary NOx outlet concentration.

[0162] S364. Determine the secondary actual reaction efficiency of the secondary SCR system based on the primary NOx outlet concentration and the secondary NOx outlet concentration.

[0163] Among them, the first-level NOx outlet concentration is also the NOx concentration at the inlet of the second-level SCR system, that is, the second-level NOx inlet concentration, so the second-level actual reaction efficiency is the ratio of the concentration difference between the first-level NOx outlet concentration and the second-level NOx outlet concentration to the first-level NOx outlet concentration, so the second-level actual reaction efficiency of the second-level SCR system can be determined based on the first-level NOx outlet concentration and the second-level NOx outlet concentration.

[0164] In some optional embodiments, only the primary actual reaction efficiency or the secondary actual reaction efficiency may be calculated separately. For example, in a specific embodiment, only the secondary actual reaction efficiency is calculated separately. In this case, the determination of the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system includes: obtaining the secondary NOx inlet concentration and the secondary NOx outlet concentration of the secondary SCR system, and determining the secondary actual reaction efficiency of the secondary SCR system based on the primary and secondary NOx inlet concentrations and the secondary NOx outlet concentrations. The primary actual reaction efficiency and / or the secondary actual reaction efficiency may be selected for calculation according to actual needs, and no specific limitation is made here.

[0165] In an optional embodiment of the present invention, determining the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system includes:

[0166] S365. Determine the secondary NOx capacity mass flow that the secondary SCR system can process based on the secondary actual reaction efficiency of the secondary SCR system.

[0167] Among them, the secondary NOx capacity mass flow is the NOx mass flow that the secondary SCR system can actually process. Specifically, the secondary NOx capacity mass flow can be calculated based on the original NOx concentration, exhaust flow and the actual secondary reaction efficiency. The original NOx concentration can be obtained by obtaining the NOx concentration detected by the upstream NOx sensor.

[0168] S366, obtain the original NOx emission mass flow rate.

[0169] The NOx original emission mass flow rate refers to the NOx mass flow rate discharged by the engine. Specifically, it can be calculated based on the NOx original emission concentration and the exhaust flow rate.

[0170] S367. Determine the primary NOx target mass flow rate of the primary SCR system based on the difference between the original NOx exhaust mass flow rate and the secondary NOx capacity mass flow rate.

[0171] Among them, the first-level NOx target mass flow rate refers to the NOx mass flow rate that the first-level SCR system plans to treat.

[0172] S368. Determine the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the NOx original exhaust mass flow rate.

[0173] S369. Determine the secondary SCR target weight based on the difference between 100% and the primary SCR target weight.

[0174] Through the above method, the primary SCR target weight and the secondary SCR target weight can be conveniently determined. When both the primary SCR system and the secondary SCR system are activated, the primary SCR target weight and the secondary SCR target weight can be dynamically adjusted according to the working conditions, giving full play to the advantages of the dual-stage SCR system in reducing and treating NOx with high robustness and the flexibility of nitrous oxide generation control.

[0175] In an optional embodiment of the present invention, determining the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate includes:

[0176] Determine whether the ratio of the primary NOx target mass flow rate to the original NOx mass flow rate exceeds a preset primary weight range, wherein the preset primary weight range includes a primary SCR weight upper limit value and a primary SCR weight lower limit value. In a specific embodiment, the primary SCR weight upper limit value is not greater than 90%, and the primary SCR weight lower limit value is not less than 60%. Preferably, the primary SCR weight lower limit value is not less than 70%.

[0177] When the ratio of the primary NOx target mass flow rate to the NOx original exhaust mass flow rate is greater than the primary weight upper limit value, the primary SCR target weight is set to the primary SCR weight upper limit value.

[0178] When the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate is less than the first-level weighted SCR lower limit value, the first-level SCR target weight is set to the first-level weighted SCR lower limit value.

[0179] When the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate does not exceed the preset first-level weight range, the first-level SCR target weight is set to the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate.

[0180] Among them, the first-level SCR weight upper limit value is the maximum value of the first-level SCR target weight when both the first-level SCR system and the second-level SCR system are activated, and the first-level SCR weight lower limit value is the minimum value of the first-level SCR target weight when both the first-level SCR system and the second-level SCR system are activated.

[0181] In the current typical two-stage SCR system, the first-stage SCR carrier is a vanadium-based SCR carrier, which has the advantages of good dynamic response, low nitrous oxide generation ratio and good sulfur resistance, but the ammonia storage capacity of the vanadium-based SCR carrier is weak. The first-stage SCR carrier is close to the outlet of the engine turbocharger, the specific heat capacity of the intermediate pipeline is small, and the temperature fluctuation inside the carrier is more intense than that of the second-stage SCR carrier.

[0182] The secondary SCR carrier is a combination of copper and iron bases, which has the advantages of high low-temperature conversion efficiency and strong ammonia storage capacity. However, the copper-based SCR carrier generates a high proportion of nitrous oxide, which is not conducive to the control of nitrous oxide pollutants.

[0183] The results of engine bench tests prove that: under the current typical two-stage SCR system scheme, when both the first-stage SCR system and the second-stage SCR system are activated, the first-stage SCR target weight is in the range of 10% to 90%. The higher the first-stage SCR target weight, the lower the final tail NOx emission value and the lower the nitrous oxide emission value.

[0184] By controlling the first-level SCR target weight not to exceed the preset first-level weight range, it is possible to achieve ultra-low tail NOx emissions while ensuring that nitrous oxide emissions levels meet regulatory requirements.

[0185] In an optional embodiment of the present invention, Figure 7 As shown, the step of determining the primary SCR required urea amount based on the primary SCR target weight includes:

[0186] S381. Determine whether the primary SCR target weight is 0%.

[0187] If the first-level SCR target weight is 0%, execute step S382; if the first-level SCR target weight is not 0%, execute step S383.

[0188] S382: Determine that the amount of urea required by the first-stage SCR is 0.

[0189] Among them, when the first-stage SCR target weight is 0%, it means that the first-stage SCR system is not activated and does not work, so the first-stage SCR system does not need to spray urea, and the first-stage SCR required urea amount is 0.

[0190] S383: Determine whether the primary SCR target weight is 100%.

[0191] If the first-level SCR target weight is 100%, execute step S384; if the first-level SCR target weight is not 100%, execute step S385.

[0192] S384. Obtain the original NOx emission concentration and exhaust flow rate, determine the first-level SCR open-loop ammonia nitrogen ratio based on the original NOx emission concentration, the first-level SCR inlet temperature and the exhaust flow rate, determine the first-level target reaction efficiency of the first-level SCR system based on the original NOx emission concentration and the exhaust flow rate, correct the first-level SCR open-loop ammonia nitrogen ratio based on the first-level target reaction efficiency and the first-level actual reaction efficiency to obtain the first-level SCR current ammonia nitrogen ratio, and calculate the first-level SCR required urea amount based on the first-level SCR current ammonia nitrogen ratio.

[0193] Among them, when the primary SCR target weight is 100%, it means that only the primary SCR system is activated and the primary SCR system is in working state, so the NOx discharged by the engine is processed by the primary SCR system.

[0194] The original NOx concentration refers to the NOx concentration discharged by the engine. The NOx concentration detected by the upstream NOx sensor can be obtained by communicating with the upstream NOx sensor as the original NOx concentration. Exhaust flow rate refers to the rate at which the engine discharges the exhaust gas generated after combustion during operation, usually expressed in liters / second or cubic meters / second. The exhaust flow rate can be directly detected by a flow meter or indirectly detected by other components, which is not specifically limited here.

[0195] The ammonia nitrogen ratio refers to the ratio of the ammonia actually supplied to the ammonia required to completely reduce the current NOx. If the ammonia nitrogen ratio is less than 1, the SCR system is in an under-spray state, and if the ammonia nitrogen ratio is greater than 1, the SCR system is in an over-spray state. Since the original NOx concentration, the first-stage SCR inlet temperature and the exhaust flow rate are correlated with the ammonia nitrogen ratio, the first-stage SCR open-loop ammonia nitrogen ratio can be determined based on the original NOx concentration, the first-stage SCR inlet temperature and the exhaust flow rate.

[0196] In a specific embodiment, the correspondence between different NOx original emission concentrations, temperatures, exhaust flow rates and ammonia nitrogen ratios can be obtained in advance through testing, so that after obtaining the NOx original emission concentration, the first-stage SCR inlet temperature and the exhaust flow rate, the temperature in the corresponding relationship is the first-stage SCR inlet temperature, and the first-stage SCR open-loop ammonia nitrogen ratio can be obtained according to the corresponding relationship. Specifically, the corresponding relationship can exist in the form of a table, so that the first-stage SCR open-loop ammonia nitrogen ratio can be obtained by simply looking up the table. In some embodiments, the corresponding relationship can also exist in other ways, which are not specifically limited here.

[0197] The primary target reaction efficiency refers to the reaction efficiency that the primary SCR system needs to achieve when the NOx mass flow rate meets the emission requirements after the primary SCR system processes the gas discharged from the engine. The original NOx mass flow rate a at the inlet of the primary SCR system is calculated based on the original NOx concentration and the exhaust flow rate. The emission regulations require the tail NOx mass flow rate to be b, and the engineering requirements require the tail NOx mass flow rate to be b1. b1 is less than b. The primary target reaction efficiency is calculated according to the following formula: primary target reaction efficiency = [(a-b1) / a]*100%. Example: a = 10g / s, b = 0.1g / s, b1 = 0.05g / s, and the calculated primary target reaction efficiency is 99.5%.

[0198] The actual primary reaction efficiency refers to the reaction efficiency of the primary SCR system in actually treating NOx. The current ammonia-nitrogen ratio of the primary SCR is the ratio of the ammonia actually supplied by the primary SCR system to the ammonia required to completely reduce the NOx that the primary SCR system currently needs to treat.

[0199] By correcting the first-stage SCR open-loop ammonia nitrogen ratio based on the first-stage target reaction efficiency and the first-stage actual reaction efficiency to obtain the first-stage SCR current ammonia nitrogen ratio, and calculating the first-stage SCR required urea amount based on the first-stage SCR current ammonia nitrogen ratio, the calculated first-stage SCR required urea amount can be made more in line with the current actual operating conditions, so that the NOx mass flow rate after treatment by the two-stage SCR system meets the requirements.

[0200] In a specific embodiment, the correcting the primary SCR open-loop ammonia nitrogen ratio based on the primary target reaction efficiency and the primary actual reaction efficiency to obtain the primary SCR current ammonia nitrogen ratio includes:

[0201] Determine whether a primary efficiency deviation between the primary target reaction efficiency and the primary actual reaction efficiency is less than a preset deviation threshold.

[0202] If the primary efficiency deviation is less than the preset deviation threshold, the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio.

[0203] If the primary efficiency deviation is not less than the preset deviation threshold, the primary corrected ammonia nitrogen ratio is determined based on the primary efficiency deviation, and the sum of the primary corrected ammonia nitrogen ratio and the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio.

[0204] Among them, the primary efficiency deviation is the difference between the primary target reaction efficiency and the primary actual reaction efficiency. When the primary efficiency deviation is less than the preset deviation threshold, it means that the primary actual reaction efficiency at this time is not much different from the primary target reaction efficiency. According to the current primary actual reaction efficiency, the treated NOx mass flow rate can meet the requirements, so there is no need to correct the primary SCR open-loop ammonia nitrogen ratio, and the primary SCR open-loop ammonia nitrogen ratio is directly determined as the primary SCR current ammonia nitrogen ratio. If the primary efficiency deviation is not less than the preset deviation threshold, it means that the primary actual reaction efficiency is too different from the primary target reaction efficiency at this time. According to the current primary actual reaction efficiency, it is difficult to make the treated NOx mass flow rate meet the requirements, so the primary SCR open-loop ammonia nitrogen ratio needs to be corrected. At this time, the primary corrected ammonia nitrogen ratio is determined based on the primary efficiency deviation, and the sum of the primary corrected ammonia nitrogen ratio and the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio, which can make the primary SCR current ammonia nitrogen ratio more in line with the actual working conditions, and the primary urea demand calculated according to the primary SCR current ammonia nitrogen ratio is more in line with the actual demand, thereby improving the reaction efficiency of the two-stage SCR system.

[0205] The following is a specific example to illustrate the specific method of calculating the current ammonia nitrogen ratio of the first-level SCR. For example, within a period of time after the start of operation, the first-level SCR open-loop ammonia nitrogen ratio is calculated to be 1.0. After a period of time, the first-level actual reaction efficiency is 98%, the first-level target reaction efficiency is 99%, and the first-level efficiency deviation is the difference between the first-level target reaction efficiency and the first-level actual reaction efficiency, that is, 1%; the preset deviation threshold is set to 5%, then the first-level efficiency deviation is less than the preset deviation threshold, and finally the first-level SCR current ammonia nitrogen ratio adopts the first-level SCR open-loop ammonia nitrogen ratio of 1.0; if after a period of time, the first-level actual reaction efficiency is 92%, the first-level target reaction efficiency is 99%, the first-level efficiency deviation is the difference between the first-level target reaction efficiency and the first-level actual reaction efficiency of 7%, and the preset deviation threshold is set to 5%, then the first-level efficiency deviation is greater than the preset deviation threshold, the first-level corrected ammonia nitrogen ratio calculated based on the first-level efficiency deviation is 0.1, and finally the current ammonia nitrogen ratio of the first-level SCR is the sum of the current ammonia nitrogen ratio of the first-level SCR and the first-level corrected ammonia nitrogen ratio calculated based on the first-level efficiency deviation, which is 1.1.

[0206] S385. Obtain the original NOx emission concentration and the exhaust flow rate, determine the first-level NOx treatment concentration based on the original NOx emission concentration and the first-level SCR target weight, determine the first-level SCR current ammonia nitrogen ratio of the first-level SCR system based on the first-level NOx treatment concentration, the first-level SCR inlet temperature and the exhaust flow rate, and calculate the first-level SCR required urea amount based on the first-level SCR current ammonia nitrogen ratio.

[0207] Among them, when the first-level SCR target weight is between 0% and 100%, it means that both the first-level SCR system and the second-level SCR system are activated. Therefore, at this time, the first-level SCR current ammonia nitrogen ratio of the first-level SCR system is directly determined according to the first-level NOx treatment concentration, the first-level SCR inlet temperature and the exhaust flow rate, and then the first-level SCR required urea amount is calculated according to the first-level SCR current ammonia nitrogen ratio, so that the first-level SCR system processes part of the NOx, and then the second-level SCR system processes the remaining NOx.

[0208] In an optional embodiment of the present invention, Figure 8 As shown, the method of determining the secondary SCR required urea amount based on the secondary SCR target weight includes:

[0209] S391. Determine whether the secondary SCR target weight is 0%.

[0210] If yes, execute step S392; if no, execute step S393.

[0211] S392: Determine that the amount of urea required by the secondary SCR is 0.

[0212] Among them, when the secondary SCR target weight is 0%, it means that the secondary SCR system is not activated at this time, and the secondary SCR system does not work, so the secondary SCR system does not need to spray urea, and the secondary SCR required urea amount is 0.

[0213] S393. Obtain the secondary SCR inlet NOx concentration and exhaust flow rate at the secondary SCR system inlet, determine the secondary SCR open-loop ammonia nitrogen ratio based on the secondary SCR inlet NOx concentration, the secondary SCR inlet temperature and the exhaust flow rate, determine the secondary target reaction efficiency of the secondary SCR system based on the secondary SCR inlet NOx concentration and the exhaust flow rate, correct the secondary SCR open-loop ammonia nitrogen ratio based on the secondary target reaction efficiency and the secondary actual reaction efficiency to obtain the secondary SCR current ammonia nitrogen ratio, and calculate the secondary SCR required urea amount based on the secondary SCR current ammonia nitrogen ratio.

[0214] Among them, when the secondary SCR target weight is not 0%, it means that the secondary SCR system is activated and the primary SCR system is in working state. Since the secondary SCR system will discharge the gas after processing, the secondary SCR system needs to process the NOx at the inlet of the secondary SCR system to meet the emission standards.

[0215] The NOx concentration at the inlet of the secondary SCR is the NOx concentration at the inlet of the secondary SCR system. The NOx concentration detected by the midstream NOx sensor can be obtained by communicating with the midstream NOx sensor as the NOx concentration at the inlet of the secondary SCR. Exhaust flow refers to the rate at which the engine discharges the exhaust gas generated after combustion during operation, usually expressed in liters / second or cubic meters / second. The exhaust flow can be directly detected by a flow meter or indirectly detected by other components, which is not specifically limited here.

[0216] Since the NOx concentration, temperature and exhaust flow are correlated with the ammonia nitrogen ratio, the secondary SCR open-loop ammonia nitrogen ratio can be determined according to the secondary SCR inlet NOx concentration, the secondary SCR inlet temperature and the exhaust flow.

[0217] In a specific embodiment, the corresponding relationship between different NOx concentrations, temperatures, exhaust flow rates and ammonia nitrogen ratios can be obtained in advance through testing, so that after obtaining the secondary SCR inlet NOx concentration, the secondary SCR inlet temperature and the exhaust flow rate, the temperature in the corresponding relationship is the secondary SCR inlet temperature, and the NOx concentration is the secondary SCR inlet NOx concentration, and the secondary SCR open-loop ammonia nitrogen ratio can be obtained according to the corresponding relationship. Specifically, the corresponding relationship can exist in the form of a table, so that the secondary SCR open-loop ammonia nitrogen ratio can be obtained by simply looking up the table. In some embodiments, the corresponding relationship can also exist in other ways, which are not specifically limited here.

[0218] The secondary target reaction efficiency refers to the reaction efficiency that the secondary SCR system needs to achieve when the NOx mass flow rate meets the emission requirements after the secondary SCR system processes the gas input into the secondary SCR system. The secondary inlet NOx mass flow rate a2 at the inlet of the secondary SCR system is calculated based on the secondary SCR inlet NOx concentration and the exhaust flow rate. The emission regulations require the tail NOx mass flow rate to be b, and the engineering requirements require the tail NOx mass flow rate to be b1. b1 is less than b. The primary target reaction efficiency is calculated according to the following formula: secondary target reaction efficiency = [(a2-b1) / a]*100%. Example: a = 10g / s, b = 0.1g / s, b1 = 0.05g / s, and the calculated secondary target reaction efficiency is 99.5%.

[0219] The secondary actual reaction efficiency refers to the reaction efficiency of the secondary SCR system in actually treating NOx. The secondary SCR current ammonia nitrogen ratio is the ratio of the ammonia actually supplied by the secondary SCR system to the ammonia required to completely reduce the NOx that the secondary SCR system currently needs to treat.

[0220] By correcting the secondary SCR open-loop ammonia nitrogen ratio based on the secondary target reaction efficiency and the secondary actual reaction efficiency to obtain the secondary SCR current ammonia nitrogen ratio, and calculating the secondary SCR required urea amount based on the secondary SCR current ammonia nitrogen ratio, the calculated secondary SCR required urea amount can be made more in line with the current actual operating conditions, so that the NOx mass flow rate after treatment by the two-stage SCR system meets the requirements.

[0221] In a specific embodiment, the correcting the secondary SCR open-loop ammonia nitrogen ratio based on the secondary target reaction efficiency and the secondary actual reaction efficiency to obtain the secondary SCR current ammonia nitrogen ratio includes:

[0222] It is determined whether a secondary efficiency deviation between the secondary target reaction efficiency and the secondary actual reaction efficiency is less than a preset deviation threshold.

[0223] If the secondary efficiency deviation is less than the preset deviation threshold, the secondary SCR open-loop ammonia nitrogen ratio is determined as the secondary SCR current ammonia nitrogen ratio.

[0224] If the secondary efficiency deviation is not less than the preset deviation threshold, the secondary corrected ammonia nitrogen ratio is determined based on the secondary efficiency deviation, and the sum of the secondary corrected ammonia nitrogen ratio and the secondary SCR open-loop ammonia nitrogen ratio is determined as the secondary SCR current ammonia nitrogen ratio.

[0225] Among them, the secondary efficiency deviation is the difference between the secondary target reaction efficiency and the secondary actual reaction efficiency. When the primary efficiency deviation is less than the preset deviation threshold, it means that the difference between the secondary actual reaction efficiency and the secondary target reaction efficiency is not large. According to the current secondary actual reaction efficiency, the treated NOx mass flow rate can meet the requirements, so there is no need to correct the secondary SCR open-loop ammonia nitrogen ratio, and the secondary SCR open-loop ammonia nitrogen ratio is directly determined as the secondary SCR current ammonia nitrogen ratio. If the primary efficiency deviation is not less than the preset deviation threshold, it means that the difference between the secondary actual reaction efficiency and the primary target reaction efficiency is too large. According to the current secondary actual reaction efficiency, it is difficult to make the treated NOx mass flow rate meet the requirements, so the secondary SCR open-loop ammonia nitrogen ratio needs to be corrected. At this time, the secondary corrected ammonia nitrogen ratio is determined based on the secondary efficiency deviation, and the sum of the secondary corrected ammonia nitrogen ratio and the secondary SCR open-loop ammonia nitrogen ratio is determined as the secondary SCR current ammonia nitrogen ratio, which can make the secondary SCR current ammonia nitrogen ratio more in line with the actual working conditions, and the secondary urea demand calculated according to the secondary SCR current ammonia nitrogen ratio is more in line with the actual demand, thereby improving the reaction efficiency of the two-stage SCR system.

[0226] In a specific embodiment, the required urea amount is calculated by the following formula:

[0227] m NH3 =1 / 3600*α Dmd *c NOX *Mol NH3 *m exh / Mol exh .

[0228] m NH3 is the urea demand; α Dmd is the ammonia nitrogen ratio; c NOX is the NOx concentration that needs to be treated; m exh is the exhaust flow rate; Mol NH3 is the molecular weight of ammonia, specifically 17.0306 g / Mol; Mol exh is the exhaust molecular weight, specifically 28.9700 g / Mol.

[0229] When the amount of urea required by the first-stage SCR needs to be calculated, the current ammonia nitrogen ratio of the first-stage SCR is used as α Dmd , the product of the original NOx concentration and the primary SCR target weight is taken as c NOX Substituting into the above formula, the calculated m NH3 This is the amount of urea required by the first-stage SCR.

[0230] When the urea amount required by the secondary SCR needs to be calculated, the current ammonia nitrogen ratio of the secondary SCR is used as α Dmd , the NOx concentration at the secondary SCR inlet is taken as cNOX Substituting into the above formula, the calculated m NH3 This is the amount of urea required by the first-stage SCR.

[0231] In an optional embodiment of the present invention, after determining the SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, the method further includes:

[0232] An SCR exhaust temperature management mode is determined based on the SCR cooperative control state, and the SCR exhaust temperature management mode includes a strong thermal management mode, a weak thermal management mode and a no thermal management mode, wherein the strong thermal management mode and the weak thermal management mode are used to increase the inlet temperature of the first-level SCR system, and the temperature raising efficiency of the strong thermal management mode is greater than the temperature raising efficiency of the weak thermal management mode.

[0233] Among them, strong heat management mode will perform strong heat raising measures, which include controlling the use of a burner or an electric heating carrier to heat the engine, so that the inlet temperature of the first-stage SCR system is increased, and then the temperature of the entire two-stage SCR system is increased. Strong heat raising measures can also include controlling the exhaust valve to open early or controlling the exhaust throttle valve to reduce the opening to increase the inlet temperature of the first-stage SCR system. The exhaust valve refers to the component that controls the exhaust of gas from the engine combustion chamber. It is responsible for discharging the exhaust gas from the combustion chamber to the two-stage SCR system. The exhaust throttle valve refers to the valve that controls the exhaust gas of the engine to be discharged into the two-stage SCR system. Through the above methods, the inlet temperature of the first-stage SCR system can be increased.

[0234] Weak thermal management mode will execute weak thermal temperature increase measures, including controlling the intake throttle opening to reduce or post-injection to increase the inlet temperature of the first-stage SCR system, but the efficiency of increasing the temperature is lower than the temperature increase measures in the strong thermal management mode.

[0235] On the basis of the above embodiment, the SCR exhaust temperature management mode is determined based on the SCR cooperative control state, and the SCR exhaust temperature management mode includes a strong thermal management mode, a weak thermal management mode and a non-thermal management mode, including:

[0236] When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive, it is determined that the SCR exhaust temperature management mode is a strong thermal management mode.

[0237] When the SCR cooperative control state is that the primary SCR system is activated or the secondary SCR system is activated, it is determined that the SCR exhaust temperature management mode is a weak thermal management mode.

[0238] When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated, it is determined that the SCR exhaust temperature management mode is a non-thermal management mode.

[0239] During the actual operation of the vehicle, it will experience cold start (exhaust temperature is room temperature 25°C) and low exhaust temperature conditions such as low load (exhaust temperature is 150°C). By determining the SCR exhaust temperature management mode based on the SCR co-control state, the proportion of the time when both the primary SCR system and the secondary SCR system are activated in the SCR co-control state to the total operating time can be expanded. For example, when the total operating time exceeds 30 minutes, the proportion of the time when both the primary SCR system and the secondary SCR system are activated in the SCR co-control state to the total operating time is not less than 80%, thereby ensuring that the final tail exhaust NOx, ammonia and nitrous oxide meet the emission regulations at the same time.

[0240] Embodiment 4

[0241] Fig. 9 This is a schematic diagram of the structure of a reaction control device for a two-stage SCR system provided in Embodiment 4 of the present invention. Fig. 9 As shown, the reaction control device of the dual-stage SCR system includes:

[0242] The primary temperature acquisition module 41 is used to acquire the primary SCR inlet temperature of the primary SCR system in real time.

[0243] The secondary temperature acquisition module 42 is used to acquire the secondary SCR inlet temperature of the secondary SCR system in real time.

[0244] The cooperative control determination module 43 is used to determine the SCR cooperative control state based on the first-level SCR inlet temperature and the second-level SCR inlet temperature, and the SCR cooperative control state includes that the first-level SCR system is activated, the second-level SCR system is activated, both the first-level SCR system and the second-level SCR system are activated, and both the first-level SCR system and the second-level SCR system are not activated.

[0245] The urea requirement determination module 44 is used to determine the primary SCR urea requirement amount of the primary SCR system and the secondary SCR urea requirement amount of the secondary SCR system based on the SCR cooperative control state.

[0246] The primary driving module 45 is used to drive the primary SCR urea nozzle to spray urea based on the primary SCR required urea amount.

[0247] The secondary driving module 46 is used to drive the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount.

[0248] In an optional embodiment of the present invention, the required urea determination module 44 includes:

[0249] The weight determination submodule is used to determine the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the SCR cooperative control state.

[0250] The primary urea determination submodule is used to determine the primary SCR required urea amount based on the primary SCR target weight.

[0251] The secondary urea determination submodule is used to determine the secondary SCR required urea amount based on the secondary SCR target weight.

[0252] In an optional embodiment of the present invention, the weight determination submodule includes:

[0253] The first weight determination unit is used to determine that the primary SCR target weight of the primary SCR system is 100% and the secondary SCR target weight of the secondary SCR system is 0% when the SCR cooperative control state is the primary SCR system activation.

[0254] The second weight determination unit is used to determine that the secondary SCR target weight of the secondary SCR system is 100% and the primary SCR target weight of the primary SCR system is 0% when the SCR cooperative control state is the secondary SCR system activation.

[0255] The third weight determination unit is used to determine the first-level actual reaction efficiency of the first-level SCR system and / or the second-level actual reaction efficiency of the second-level SCR system when the SCR co-control state is that both the first-level SCR system and the second-level SCR system are activated, and determine the first-level SCR target weight of the first-level SCR system and the second-level SCR target weight of the second-level SCR system based on the first-level actual reaction efficiency and / or the second-level actual reaction efficiency, wherein the sum of the first-level SCR target weight and the second-level SCR target weight is 100%.

[0256] The fourth weight determination unit is used to determine that the primary SCR target weight of the primary SCR system is 0% and the secondary SCR target weight of the secondary SCR system is 0% when the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive.

[0257] In an optional embodiment of the present invention, the third weight determination unit includes:

[0258] The primary outlet concentration acquisition subunit is used to acquire the primary NOx outlet concentration at the outlet of the primary SCR system.

[0259] The primary actual efficiency determination subunit is used to determine the primary actual reaction efficiency of the primary SCR system based on the original NOx exhaust concentration and the primary NOx outlet concentration.

[0260] The secondary outlet concentration acquisition subunit is used to acquire the secondary NOx outlet concentration at the outlet of the secondary SCR system.

[0261] The secondary actual efficiency determination subunit is used to determine the secondary actual reaction efficiency of the secondary SCR system based on the primary NOx outlet concentration and the secondary NOx outlet concentration.

[0262] In an optional embodiment of the present invention, the secondary actual reaction efficiency of the secondary SCR system is negatively correlated with the primary SCR target weight.

[0263] And / or, the primary actual reaction efficiency of the primary SCR system is positively correlated with the primary SCR target weight.

[0264] In an optional embodiment of the present invention, the third weight determination unit further includes:

[0265] The capacity mass flow determination subunit is used to determine the secondary NOx capacity mass flow that the secondary SCR system can process based on the secondary actual reaction efficiency of the secondary SCR system.

[0266] The original exhaust mass flow determination subunit is used to obtain the original exhaust mass flow of NOx.

[0267] The target mass flow determination subunit is used to determine the primary NOx target mass flow of the primary SCR system based on the difference between the original NOx exhaust mass flow and the secondary NOx capacity mass flow.

[0268] The primary weight determination subunit is used to determine the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the NOx original exhaust mass flow rate.

[0269] The secondary weight determination subunit is used to determine the secondary SCR target weight based on the difference between 100% and the primary SCR target weight.

[0270] In an optional embodiment of the present invention, the first-level weight determination subunit includes:

[0271] The weight determination micro-unit is used to determine whether the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate exceeds a preset first-level weight range, wherein the preset first-level weight range includes a first-level SCR weight upper limit value and a first-level SCR weight lower limit value.

[0272] The first weight determination micro unit is used to set the first-level SCR target weight to the first-level SCR weight upper limit value when the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate is greater than the first-level weight upper limit value.

[0273] The second weight determination micro unit is used to set the first-level SCR target weight to the first-level weight SCR lower limit value when the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate is less than the first-level weight SCR lower limit value.

[0274] The third weight determination micro unit is used to set the first-level SCR target weight to the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate when the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate does not exceed the preset first-level weight range.

[0275] In an optional embodiment of the present invention, the primary urea determination submodule includes:

[0276] The first primary weight determination unit is used to determine whether the primary SCR target weight is 0%.

[0277] The first primary weight determination unit is used to determine that the primary SCR required urea amount is 0 if the primary SCR target weight is 0%.

[0278] The second primary weight determination unit is configured to determine whether the primary SCR target weight is 100% if the primary SCR target weight is not 0%.

[0279] The second first-level weight determination unit is used to obtain the original NOx emission concentration and the exhaust flow rate if the first-level SCR target weight is 100%, determine the first-level SCR open-loop ammonia nitrogen ratio based on the original NOx emission concentration, the first-level SCR inlet temperature and the exhaust flow rate, determine the first-level target reaction efficiency of the first-level SCR system based on the original NOx emission concentration and the exhaust flow rate, correct the first-level SCR open-loop ammonia nitrogen ratio based on the first-level target reaction efficiency and the first-level actual reaction efficiency to obtain the first-level SCR current ammonia nitrogen ratio, and calculate the first-level SCR required urea amount based on the first-level SCR current ammonia nitrogen ratio.

[0280] The third first-level weight determination unit is used to obtain the original NOx emission concentration and the exhaust flow rate if the first-level SCR target weight is not 100%, determine the first-level NOx treatment concentration based on the original NOx emission concentration and the first-level SCR target weight, determine the first-level SCR current ammonia nitrogen ratio of the first-level SCR system based on the first-level NOx treatment concentration, the first-level SCR inlet temperature and the exhaust flow rate, and calculate the first-level SCR required urea amount based on the first-level SCR current ammonia nitrogen ratio.

[0281] In an optional embodiment of the present invention, the second primary weight determination unit includes:

[0282] The deviation determination subunit is used to determine whether the first-level efficiency deviation between the first-level target reaction efficiency and the first-level actual reaction efficiency is less than a preset deviation threshold.

[0283] The first ammonia nitrogen ratio determination subunit is used to determine the first-stage SCR open-loop ammonia nitrogen ratio as the first-stage SCR current ammonia nitrogen ratio if the first-stage efficiency deviation is less than the preset deviation threshold.

[0284] The second ammonia nitrogen ratio determination subunit is used to determine the first-level corrected ammonia nitrogen ratio based on the first-level efficiency deviation if the first-level efficiency deviation is not less than the preset deviation threshold, and determine the sum of the first-level corrected ammonia nitrogen ratio and the first-level SCR open-loop ammonia nitrogen ratio as the first-level SCR current ammonia nitrogen ratio.

[0285] In an optional embodiment of the present invention, the secondary urea determination submodule includes:

[0286] The first secondary weight determination unit is used to determine whether the secondary SCR target weight is 0%.

[0287] The first secondary weight determination unit is used to determine that if yes, the secondary SCR required urea amount is 0.

[0288] The second secondary weight determination unit is used for, if not, obtaining the secondary SCR inlet NOx concentration and the exhaust flow rate at the inlet of the secondary SCR system, determining the secondary SCR open-loop ammonia nitrogen ratio based on the secondary SCR inlet NOx concentration, the secondary SCR inlet temperature and the exhaust flow rate, determining the secondary target reaction efficiency of the secondary SCR system based on the secondary SCR inlet NOx concentration and the exhaust flow rate, correcting the secondary SCR open-loop ammonia nitrogen ratio based on the secondary target reaction efficiency and the secondary actual reaction efficiency to obtain the secondary SCR current ammonia nitrogen ratio, and calculating the secondary SCR required urea amount based on the secondary SCR current ammonia nitrogen ratio.

[0289] In an optional embodiment of the present invention, the cooperative control determination module 43 includes:

[0290] The cooperative control determination submodule is used to determine whether the first-stage SCR inlet temperature is greater than a preset start-up temperature threshold and determine whether the second-stage SCR inlet temperature is greater than the preset start-up temperature threshold.

[0291] The first cooperative control determination submodule is used to determine that the SCR cooperative control state is that the first-level SCR system is activated when the first-level SCR inlet temperature is greater than a preset start-up temperature threshold and the second-level SCR inlet temperature is less than or equal to the preset start-up temperature threshold.

[0292] The second cooperative control determination submodule is used to determine that the SCR cooperative control state is the secondary SCR system activation when the primary SCR inlet temperature is less than or equal to a preset start-up temperature threshold and the secondary SCR inlet temperature is greater than the preset start-up temperature threshold.

[0293] The third cooperative control determination submodule is used to determine that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated when the primary SCR inlet temperature and the secondary SCR inlet temperature are both greater than a preset injection start temperature threshold.

[0294] The fourth cooperative control determination submodule is used to determine that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive when the primary SCR inlet temperature and the secondary SCR inlet temperature are both less than or equal to a preset injection start temperature threshold.

[0295] In an optional embodiment of the present invention, the reaction control device of the dual-stage SCR system further includes:

[0296] The exhaust temperature management determination module is used to determine the SCR exhaust temperature management mode based on the SCR cooperative control state, and the SCR exhaust temperature management mode includes a strong thermal management mode, a weak thermal management mode and a no thermal management mode, wherein the strong thermal management mode and the weak thermal management mode are used to increase the inlet temperature of the first-level SCR system, and the heating efficiency of the strong thermal management mode is greater than the heating efficiency of the weak thermal management mode.

[0297] In an optional embodiment of the present invention, the exhaust temperature management determination module includes:

[0298] The strong heat determination submodule is used to determine that the SCR exhaust temperature management mode is the strong heat management mode when the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are not activated.

[0299] The weak heat determination submodule is used to determine that the SCR exhaust temperature management mode is a weak heat management mode when the SCR cooperative control state is the first-level SCR system activation or the second-level SCR system activation.

[0300] The no-heat determination submodule is used to determine that the SCR exhaust temperature management mode is the no-heat management mode when the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated.

[0301] The reaction control device of the two-stage SCR system provided in the embodiment of the present invention can execute the reaction control device method of the two-stage SCR system provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0302] Embodiment 5

[0303] Fig.10A schematic diagram of a reaction control system of a dual-stage SCR system that can be used to implement an embodiment of the present invention is shown. The reaction control system of the dual-stage SCR system is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The reaction control system of the dual-stage SCR system can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein. In a specific embodiment, the reaction control system of the dual-stage SCR system can be configured in an engine management system.

[0304] like Fig.10 As shown, the reaction control system of the dual-stage SCR system includes at least one processor 11, and a memory connected to the at least one processor 11 in communication, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. Various programs and data required for the operation of the reaction control system of the dual-stage SCR system can also be stored in the RAM 13. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0305] A number of components in the reaction control system of the dual-stage SCR system are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the reaction control system of the dual-stage SCR system to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0306] The processor 11 may be a variety of general and / or dedicated processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the reaction control method of the dual-stage SCR system.

[0307] In some embodiments, the reaction control method of the dual-stage SCR system may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the reaction control system of the dual-stage SCR system via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the reaction control method of the dual-stage SCR system described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute the reaction control method of the dual-stage SCR system in any other appropriate manner (e.g., by means of firmware).

[0308] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0309] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0310] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0311] To provide interaction with a user, the systems and techniques described herein may be implemented on a reaction control system of a dual-stage SCR system having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to a user; and a keyboard and pointing device (e.g., a mouse or trackball) through which a user may provide input to the reaction control system of the dual-stage SCR system. Other types of devices may also be used to provide interaction with a user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0312] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0313] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0314] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0315] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A reaction control method for a two-stage SCR system, characterized in that: include: Real-time acquisition of the primary SCR inlet temperature of the primary SCR system; Real-time acquisition of the secondary SCR inlet temperature of the secondary SCR system; Determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, the SCR cooperative control state including primary SCR system activation, secondary SCR system activation, both the primary SCR system and the secondary SCR system activation, and both the primary SCR system and the secondary SCR system inactivation; Determining a primary SCR required urea amount of the primary SCR system and a secondary SCR required urea amount of the secondary SCR system based on the SCR cooperative control state; driving a first-stage SCR urea nozzle to spray urea based on a urea amount required by the first-stage SCR; driving the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount; After determining the SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, the method further includes: Determining an SCR exhaust temperature management mode based on the SCR cooperative control state, the SCR exhaust temperature management mode including a strong thermal management mode, a weak thermal management mode and a non-thermal management mode, wherein the strong thermal management mode and the weak thermal management mode are used to increase the inlet temperature of the primary SCR system, and the temperature raising efficiency of the strong thermal management mode is greater than the temperature raising efficiency of the weak thermal management mode; The SCR exhaust temperature management mode is determined based on the SCR cooperative control state, and the SCR exhaust temperature management mode includes a strong thermal management mode, a weak thermal management mode and a non-thermal management mode, including: When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive, determining that the SCR exhaust temperature management mode is a strong thermal management mode; When the SCR cooperative control state is that the first-level SCR system is activated or the second-level SCR system is activated, determining that the SCR exhaust temperature management mode is a weak thermal management mode; When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated, it is determined that the SCR exhaust temperature management mode is a non-thermal management mode.

2. The reaction control method of the dual-stage SCR system according to claim 1, characterized in that: The determining, based on the SCR cooperative control state, the primary SCR required urea amount of the primary SCR system and the secondary SCR required urea amount of the secondary SCR system includes: Determining a primary SCR target weight of the primary SCR system and a secondary SCR target weight of the secondary SCR system based on the SCR cooperative control state; Determining a primary SCR required urea amount based on the primary SCR target weight; The secondary SCR required urea amount is determined based on the secondary SCR target weight.

3. The reaction control method of the dual-stage SCR system according to claim 2, characterized in that: The determining, based on the SCR cooperative control state, a primary SCR target weight of the primary SCR system and a secondary SCR target weight of the secondary SCR system includes: When the SCR cooperative control state is that the primary SCR system is activated, determining that the primary SCR target weight of the primary SCR system is 100% and the secondary SCR target weight of the secondary SCR system is 0%; When the SCR cooperative control state is that the secondary SCR system is activated, determining that the secondary SCR target weight of the secondary SCR system is 100% and the primary SCR target weight of the primary SCR system is 0%; When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated, determining the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system, and determining the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the primary actual reaction efficiency and / or the secondary actual reaction efficiency, wherein the sum of the primary SCR target weight and the secondary SCR target weight is 100%; When the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive, it is determined that the primary SCR target weight of the primary SCR system is 0% and the secondary SCR target weight of the secondary SCR system is 0%.

4. The reaction control method of the dual-stage SCR system according to claim 3, characterized in that: The determining of the primary actual reaction efficiency of the primary SCR system and / or the secondary actual reaction efficiency of the secondary SCR system includes: Obtaining a primary NOx outlet concentration at an outlet of the primary SCR system; Determining the primary actual reaction efficiency of the primary SCR system based on the original NOx emission concentration and the primary NOx outlet concentration; Obtaining a secondary NOx outlet concentration at an outlet of the secondary SCR system; A secondary actual reaction efficiency of the secondary SCR system is determined based on the primary NOx outlet concentration and the secondary NOx outlet concentration.

5. The reaction control method of the dual-stage SCR system according to claim 3, characterized in that: The secondary actual reaction efficiency of the secondary SCR system is negatively correlated with the primary SCR target weight; And / or, the primary actual reaction efficiency of the primary SCR system is positively correlated with the primary SCR target weight.

6. The reaction control method of the dual-stage SCR system according to claim 5, characterized in that: The determining the primary SCR target weight of the primary SCR system and the secondary SCR target weight of the secondary SCR system based on the primary actual reaction efficiency and / or the secondary actual reaction efficiency includes: Determining the secondary NOx capacity mass flow rate that the secondary SCR system can process based on the secondary actual reaction efficiency of the secondary SCR system; Obtain the original NOx emission mass flow rate; Determining a primary NOx target mass flow rate of the primary SCR system based on a difference between the original NOx exhaust mass flow rate and the secondary NOx capacity mass flow rate; Determining the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate; The secondary SCR target weight is determined based on a difference between 100% and the primary SCR target weight.

7. The reaction control method of the dual-stage SCR system according to claim 6, characterized in that: The determining the primary SCR target weight of the primary SCR system based on the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate comprises: Determine whether the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate exceeds a preset primary weight range, wherein the preset primary weight range includes a primary SCR weight upper limit value and a primary SCR weight lower limit value; When the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate is greater than the primary weight upper limit value, the primary SCR target weight is set to the primary SCR weight upper limit value; When the ratio of the primary NOx target mass flow rate to the original NOx exhaust mass flow rate is less than the primary weighted SCR lower limit value, the primary SCR target weight is set to the primary weighted SCR lower limit value; When the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate does not exceed the preset first-level weight range, the first-level SCR target weight is set to the ratio of the first-level NOx target mass flow rate to the NOx original exhaust mass flow rate.

8. The reaction control method of the dual-stage SCR system according to any one of claims 3 to 7, characterized in that: The determining the primary SCR required urea amount based on the primary SCR target weight includes: Determining whether the primary SCR target weight is 0%; If the primary SCR target weight is 0%, the primary SCR required urea amount is determined to be 0; If the primary SCR target weight is not 0%, determining whether the primary SCR target weight is 100%; If the primary SCR target weight is 100%, the original NOx emission concentration and the exhaust flow rate are obtained, the primary SCR open-loop ammonia nitrogen ratio is determined based on the original NOx emission concentration, the primary SCR inlet temperature and the exhaust flow rate, the primary target reaction efficiency of the primary SCR system is determined based on the original NOx emission concentration and the exhaust flow rate, the primary SCR open-loop ammonia nitrogen ratio is corrected based on the primary target reaction efficiency and the primary actual reaction efficiency to obtain the primary SCR current ammonia nitrogen ratio, and the primary SCR required urea amount is calculated based on the primary SCR current ammonia nitrogen ratio; If the first-level SCR target weight is not 100%, obtain the original NOx emission concentration and the exhaust flow rate, determine the first-level NOx treatment concentration based on the original NOx emission concentration and the first-level SCR target weight, determine the first-level SCR current ammonia nitrogen ratio of the first-level SCR system based on the first-level NOx treatment concentration, the first-level SCR inlet temperature and the exhaust flow rate, and calculate the first-level SCR required urea amount based on the first-level SCR current ammonia nitrogen ratio.

9. The reaction control method of the dual-stage SCR system according to claim 8, characterized in that: The correcting the first-stage SCR open-loop ammonia nitrogen ratio based on the first-stage target reaction efficiency and the first-stage actual reaction efficiency to obtain the first-stage SCR current ammonia nitrogen ratio includes: Determining whether a primary efficiency deviation between the primary target reaction efficiency and the primary actual reaction efficiency is less than a preset deviation threshold; If the primary efficiency deviation is less than the preset deviation threshold, the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio; If the primary efficiency deviation is not less than the preset deviation threshold, the primary corrected ammonia nitrogen ratio is determined based on the primary efficiency deviation, and the sum of the primary corrected ammonia nitrogen ratio and the primary SCR open-loop ammonia nitrogen ratio is determined as the primary SCR current ammonia nitrogen ratio.

10. The reaction control method of the dual-stage SCR system according to any one of claims 3 to 7, characterized in that: The determining the secondary SCR required urea amount based on the secondary SCR target weight includes: Determining whether the secondary SCR target weight is 0%; If so, determine that the amount of urea required by the secondary SCR is 0; If not, obtain the secondary SCR inlet NOx concentration and exhaust flow rate at the secondary SCR system inlet, determine the secondary SCR open-loop ammonia nitrogen ratio based on the secondary SCR inlet NOx concentration, the secondary SCR inlet temperature and the exhaust flow rate, determine the secondary target reaction efficiency of the secondary SCR system based on the secondary SCR inlet NOx concentration and the exhaust flow rate, correct the secondary SCR open-loop ammonia nitrogen ratio based on the secondary target reaction efficiency and the secondary actual reaction efficiency to obtain the secondary SCR current ammonia nitrogen ratio, and calculate the secondary SCR required urea amount based on the secondary SCR current ammonia nitrogen ratio.

11. The reaction control method of the dual-stage SCR system according to any one of claims 1 to 7, characterized in that: The determining of the SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, wherein the SCR cooperative control state includes the primary SCR system being activated, the secondary SCR system being activated, both the primary SCR system and the secondary SCR system being activated, and both the primary SCR system and the secondary SCR system being inactivated, includes: Determining whether the primary SCR inlet temperature is greater than a preset start-up temperature threshold and determining whether the secondary SCR inlet temperature is greater than the preset start-up temperature threshold; When the first-stage SCR inlet temperature is greater than a preset start-up temperature threshold and the second-stage SCR inlet temperature is less than or equal to the preset start-up temperature threshold, determining that the SCR cooperative control state is the first-stage SCR system activation; When the primary SCR inlet temperature is less than or equal to a preset start-up temperature threshold and the secondary SCR inlet temperature is greater than the preset start-up temperature threshold, determining that the SCR cooperative control state is a secondary SCR system activation; When the primary SCR inlet temperature and the secondary SCR inlet temperature are both greater than a preset injection start temperature threshold, determining that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are activated; When the primary SCR inlet temperature and the secondary SCR inlet temperature are both less than or equal to a preset injection start temperature threshold, it is determined that the SCR cooperative control state is that both the primary SCR system and the secondary SCR system are inactive.

12. A reaction control device for a two-stage SCR system, which is controlled by the reaction control method for a two-stage SCR system according to any one of claims 1 to 11, characterized in that: include: The primary temperature acquisition module is used to obtain the primary SCR inlet temperature of the primary SCR system in real time; A secondary temperature acquisition module is used to obtain the secondary SCR inlet temperature of the secondary SCR system in real time; a cooperative control determination module, configured to determine an SCR cooperative control state based on the primary SCR inlet temperature and the secondary SCR inlet temperature, wherein the SCR cooperative control state includes an activated primary SCR system, an activated secondary SCR system, both the primary SCR system and the secondary SCR system are activated, and both the primary SCR system and the secondary SCR system are inactivated; a urea requirement determination module, configured to determine a primary SCR urea requirement amount of the primary SCR system and a secondary SCR urea requirement amount of the secondary SCR system based on the SCR cooperative control state; A primary driving module, used for driving a primary SCR urea nozzle to spray urea based on a urea amount required by the primary SCR; The secondary driving module is used to drive the secondary SCR urea nozzle to spray urea based on the secondary SCR required urea amount.

13. A reaction control system of a dual-stage SCR system, characterized in that: The reaction control system of the dual-stage SCR system includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the reaction control method of the dual-stage SCR system according to any one of claims 1-11.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the reaction control method of the dual-stage SCR system according to any one of claims 1 to 11 when the processor executes the computer instructions.

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