CN116104617A - SCR efficiency control method and device and SCR system - Google Patents

SCR efficiency control method and device and SCR system Download PDF

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Publication number
CN116104617A
CN116104617A CN202310393915.2A CN202310393915A CN116104617A CN 116104617 A CN116104617 A CN 116104617A CN 202310393915 A CN202310393915 A CN 202310393915A CN 116104617 A CN116104617 A CN 116104617A
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stage
post
injection rate
urea nozzle
scr
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CN202310393915.2A
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CN116104617B (en
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庞斌
李万里
孙选建
李钊
褚国良
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Weichai Power Co Ltd
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Weichai Power Co Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N9/00—Electrical control of exhaust gas treating apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2066—Selective catalytic reduction [SCR]
    • F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Abstract

The application provides a control method and device of SCR efficiency and an SCR system, wherein the method comprises the following steps: the method comprises the following steps: acquiring conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR; adjusting the injection rate of the urea nozzle at the front stage according to the SCR efficiency at the first front stage, and adjusting the injection rate of the urea nozzle at the rear stage according to the SCR efficiency at the first rear stage; after the preset time, the second pre-stage SCR efficiency of the pre-stage SCR and the second post-stage SCR efficiency of the post-stage SCR are obtained, and at least the injection rate of the pre-stage urea nozzle is continuously adjusted according to the second pre-stage SCR efficiency, and/or at least the injection rate of the post-stage urea nozzle is continuously adjusted according to the second post-stage SCR efficiency. The injection quantity of the urea nozzle can be adjusted in a targeted manner, so that the NOx conversion efficiency of the SCR system is effectively improved, and the problem that the NOx conversion efficiency of the SCR system in the prior art is low is solved.

Description

SCR efficiency control method and device and SCR system
Technical Field
The application relates to the technical field of SCR systems, in particular to a control method and device of SCR efficiency, a computer readable storage medium and an SCR system.
Background
For the SCR system, the injection of two nozzles needs to be coordinated and controlled, so that the two-stage SCR efficiency is optimal, the emission meets the requirement, but after one-stage SCR efficiency is abnormal, the injection control is led to fail, so that ammonia leakage or exceeding emission is caused, the improvement of the NOx conversion efficiency of the double-injection SCR is crucial to emission, the existing scheme is only to adjust through the NOx conversion efficiency of the integral SCR, so that the adjustment efficiency is lower, and the NOx conversion efficiency of the integral SCR after adjustment is not obviously improved.
Disclosure of Invention
The main objective of the present application is to provide a control method and apparatus for SCR efficiency, a computer readable storage medium and an SCR system, so as to at least solve the problem of low NOx conversion efficiency of the SCR system in the prior art.
To achieve the above object, according to one aspect of the present application, there is provided a control method of SCR efficiency, the method comprising: obtaining conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR, and obtaining first front-stage SCR efficiency and first rear-stage SCR efficiency; adjusting the injection rate of a front-stage urea nozzle according to the first front-stage SCR efficiency, and adjusting the injection rate of a rear-stage urea nozzle according to the first rear-stage SCR efficiency; after a preset time, obtaining second pre-stage SCR efficiency of the pre-stage SCR and second post-stage SCR efficiency of the post-stage SCR, and at least continuously adjusting the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and/or at least continuously adjusting the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency.
Optionally, adjusting the injection rate of the urea nozzle at the previous stage according to the SCR efficiency at the first previous stage, and adjusting the injection rate of the urea nozzle at the next stage according to the SCR efficiency at the first next stage, including: under the condition that the first pre-stage SCR efficiency is smaller than a first efficiency threshold, increasing the injection rate of the pre-stage urea nozzle by a first preset injection correction value to obtain a first pre-stage correction injection rate, and controlling the pre-stage urea nozzle to inject urea by adopting the first pre-stage correction injection rate; and under the condition that the first post-stage SCR efficiency is smaller than a second efficiency threshold, increasing the injection rate of the post-stage urea nozzle by a second preset injection correction value to obtain a first post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea by adopting the first post-stage corrected injection rate.
Optionally, at least continuously adjusting the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency includes: and under the condition that the second pre-stage SCR efficiency is larger than the first pre-stage SCR efficiency, increasing the first pre-stage correction injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage correction injection rate, controlling the pre-stage urea nozzle to adopt the second pre-stage correction injection rate to inject urea, under the condition that the second pre-stage SCR efficiency is smaller than or equal to the first pre-stage SCR efficiency, reducing the first pre-stage correction injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage correction injection rate, controlling the pre-stage urea nozzle to adopt the third pre-stage correction injection rate to inject urea, and increasing the first post-stage correction injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage correction injection rate, and controlling the post-stage urea nozzle to adopt the second post-stage correction injection rate to inject urea.
Optionally, at least continuously adjusting the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency includes: increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value under the condition that the second post-stage SCR efficiency is greater than the first post-stage SCR efficiency to obtain a third post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea by adopting the third post-stage corrected injection rate; and when the second post-stage SCR efficiency is smaller than or equal to the first post-stage SCR efficiency, reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea by adopting the second post-stage corrected injection rate, and increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by adopting the second pre-stage corrected injection rate.
Optionally, at least continuing to adjust the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and at least continuing to adjust the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency, including: reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by the third pre-stage corrected injection rate under the condition that the second pre-stage SCR efficiency is smaller than or equal to the first pre-stage SCR efficiency and the second post-stage SCR efficiency is smaller than or equal to the first post-stage SCR efficiency; and reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value under the condition that the second pre-stage SCR efficiency is smaller than or equal to the first pre-stage SCR efficiency and the second post-stage SCR efficiency is smaller than or equal to the first post-stage SCR efficiency to obtain a second post-stage corrected injection rate, controlling the post-stage urea nozzle to adopt the second post-stage corrected injection rate to inject urea, and controlling an engine to reduce the exhaust gas injection quantity of the tail gas end of the engine.
Optionally, controlling the pre-stage urea nozzle to inject urea with the third pre-stage modified injection rate includes: acquiring an absolute value of a first difference value, wherein the first difference value is a difference value between the second front-stage SCR efficiency and the first front-stage SCR efficiency; reducing the opening degree of the preceding-stage urea nozzle by a first opening degree under the condition that the absolute value of the first difference value is larger than or equal to a first phase difference threshold value, so that the preceding-stage urea nozzle adopts the third preceding-stage corrected injection rate to inject urea; and under the condition that the first difference value is smaller than the first phase difference threshold value, reducing the opening degree of the pre-stage urea nozzle by a second opening degree so that the pre-stage urea nozzle adopts the third pre-stage correction injection rate to inject urea, wherein the second opening degree is smaller than the first opening degree.
Optionally, controlling the pre-stage urea nozzle to inject urea with the first pre-stage modified injection rate includes: acquiring an absolute value of a second difference value, wherein the second difference value is a difference value between the first pre-stage SCR efficiency and the first pre-stage SCR efficiency; increasing the opening of the pre-stage urea nozzle by a third opening under the condition that the absolute value of the second difference value is larger than or equal to a second difference threshold value, so that the pre-stage urea nozzle adopts the first pre-stage correction injection rate to inject urea; and under the condition that the absolute value of the second difference value is smaller than the second phase difference threshold value, increasing the opening of the pre-stage urea nozzle by a fourth opening so that the pre-stage urea nozzle adopts the first pre-stage correction injection rate to inject urea, wherein the fourth opening is smaller than the third opening.
According to another aspect of the present application, there is provided a control device of SCR efficiency, the device including an acquisition unit, a first adjustment unit, and a second adjustment unit; the acquisition unit is used for acquiring conversion efficiency of nitrogen oxides NOx of the front-stage SCR and the rear-stage SCR to obtain first front-stage SCR efficiency and first rear-stage SCR efficiency; the first adjusting unit is used for adjusting the injection rate of the front-stage urea nozzle according to the first front-stage SCR efficiency and adjusting the injection rate of the rear-stage urea nozzle according to the first rear-stage SCR efficiency; the second adjusting unit is configured to obtain a second pre-stage SCR efficiency of the pre-stage SCR and a second post-stage SCR efficiency of the post-stage SCR after a preset time, and at least continuously adjust the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and/or at least continuously adjust the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency.
According to another aspect of the present application, there is provided that the computer readable storage medium includes a stored program, where the program when executed controls a device in which the computer readable storage medium is located to perform any one of the SCR efficiency control methods.
According to another aspect of the present application, there is provided an SCR system, the SCR system including a pre-stage SCR for communicating with a tail gas end of an engine through a first pipe, a post-stage SCR for communicating with the post-stage SCR through a second pipe, a controller for communicating with the pre-stage urea nozzle and the post-stage urea nozzle, the controller for communicating with the engine, and for executing any one of the SCR efficiency control methods.
By the technical scheme, the NOx conversion efficiency of the front-stage SCR and the NOx conversion efficiency of the rear-stage SCR are respectively obtained to be considered, so that the injection quantity of the urea nozzle can be adjusted in a targeted mode, the NOx conversion efficiency of the SCR system is effectively improved, and the problem that the NOx conversion efficiency of the SCR system is lower in the prior art is solved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:
Fig. 1 is a block diagram showing a hardware configuration of a mobile terminal according to a control method of SCR efficiency provided in an embodiment of the present application;
FIG. 2 illustrates a flow diagram of a method for controlling SCR efficiency, provided in accordance with an embodiment of the present application;
FIG. 3 shows a schematic flow chart for adjusting the injection rate of a pre-stage urea nozzle based on the first pre-stage SCR efficiency and adjusting the injection rate of a post-stage urea nozzle based on the first post-stage SCR efficiency;
FIG. 4 illustrates at least continuing to adjust the injection rate of the pre-stage urea nozzle based on the second pre-stage SCR efficiency;
FIG. 5 shows at least continued adjustment of the injection rate of the post-stage urea nozzle based on the second post-stage SCR efficiency
FIG. 6 illustrates a flow diagram of another SCR efficiency control method provided in accordance with an embodiment of the present application;
FIG. 7 shows a block diagram of a control device for SCR efficiency provided in accordance with an embodiment of the present application;
fig. 8 shows a schematic diagram of an SCR system provided according to an embodiment of the present application.
Wherein the above figures include the following reference numerals:
102. a processor; 104. a memory; 106. a transmission device; 108. an input-output device; 110. a pre-stage SCR; 120. a post-stage SCR; 130. a pre-urea nozzle; 140. a post urea nozzle; 210. a first NOx sensor; 220. a DPF; 230. a first temperature sensor; 240. a pre-DOC; 250. front stage ASC; 260. a second NOx sensor; 270. a second temperature sensor; 280. HC injector; 290. a post DOC; 310. a rear stage ASC; 320. a third NOx sensor; 330. and a third temperature sensor.
Detailed Description
It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
In order to make the present application solution better understood by those skilled in the art, the following description will be made in detail and with reference to the accompanying drawings in the embodiments of the present application, it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the present application described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
For convenience of description, the following will describe some terms or terms related to the embodiments of the present application:
DOC: diesel Oxidation Catalysis oxidation catalysis technology of particulate matters.
DPF: diesel particulate filter, particulate matter trap.
SCR: selective catalytic reduction (Selective Catalytic Reduction, SCR). Refers to the use of a reducing agent (e.g., NH) 3 ) Selectively reacts with NOx in the flue gas and generates nontoxic and pollution-free N 2 And H 2 O。
ASC: (Ammonia slip catalyst) Ammonia slip catalyst to prevent NH 3 Leakage, NH 3 Oxidized to N2.
Urea: urea for diesel engine generates NH through hydrolysis reaction 3 By NH 3 Reacting NOx in the exhaust gas as a reducing agent to form N 2 。
As described in the background art, for an SCR system, injection of two nozzles needs to be coordinated and controlled, so that the two-stage SCR efficiency is optimal, and emission meets the requirement, but when one of the two-stage SCR efficiency is abnormal, injection control is disabled, so that ammonia leakage or emission exceeding is caused, therefore, the improvement of the NOx conversion efficiency of the two-stage SCR is crucial to emission, the existing scheme is to adjust the NOx conversion efficiency of the integral SCR only, so that the adjustment efficiency is low, the NOx conversion efficiency of the integral SCR after adjustment is not obviously improved frequently, and in order to solve the problem of low NOx conversion efficiency of the SCR system in the prior art, the embodiment of the application provides a control method, a device, a computer-readable storage medium and the SCR system for SCR efficiency.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
The method embodiments provided in the embodiments of the present application may be performed in a mobile terminal, a computer terminal or similar computing device. Taking the operation on a mobile terminal as an example, fig. 1 is a block diagram of a hardware structure of a mobile terminal according to a control method of SCR efficiency according to an embodiment of the present invention. As shown in fig. 1, a mobile terminal may include one or more (only one is shown in fig. 1) processors 102 (the processor 102 may include, but is not limited to, a microprocessor MCU or a processing device such as a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 for communication functions and an input-output device 108. It will be appreciated by those skilled in the art that the structure shown in fig. 1 is merely illustrative and not limiting of the structure of the mobile terminal described above. For example, the mobile terminal may also include more or fewer components than shown in fig. 1, or have a different configuration than shown in fig. 1.
The memory 104 may be used to store a computer program, for example, a software program of application software and a module, such as a computer program corresponding to a display method of device information in an embodiment of the present invention, and the processor 102 executes the computer program stored in the memory 104 to perform various functional applications and data processing, that is, to implement the above-described method. Memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, which may be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or transmit data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, simply referred to as NIC) that can connect to other network devices through a base station to communicate with the internet. In one example, the transmission device 106 may be a Radio Frequency (RF) module, which is configured to communicate with the internet wirelessly.
In the present embodiment, a control method of SCR efficiency is provided that operates on a mobile terminal, a computer terminal, or a similar computing device, it should be noted that the steps illustrated in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and that although a logical sequence is illustrated in the flowchart, in some cases the steps illustrated or described may be performed in a different order than that herein.
Fig. 2 is a flow chart of a control method for SCR efficiency according to an embodiment of the present application. As shown in fig. 2, the method comprises the steps of:
step S201, obtaining conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR, and obtaining first front-stage SCR efficiency and first rear-stage SCR efficiency;
specifically, the conversion efficiency of the NOx of the front-stage SCR and the conversion efficiency of the NOx of the rear-stage SCR are respectively obtained, so that the conversion efficiency of the NOx can be analyzed more finely than the existing scheme, and the overall conversion efficiency of the NOx is improved;
step S202, adjusting the injection rate of a front-stage urea nozzle according to the first front-stage SCR efficiency, and adjusting the injection rate of a rear-stage urea nozzle according to the first rear-stage SCR efficiency;
Specifically, for example, when the first preceding SCR efficiency is 70% or less, the injection rate of the preceding urea nozzle needs to be increased, when the first preceding SCR efficiency is 70% or more, the injection rate of the preceding urea nozzle does not need to be adjusted, and for example, when the first succeeding SCR efficiency is 70% or less, the injection rate of the succeeding urea nozzle needs to be increased, and when the first succeeding SCR efficiency is 70% or more, the injection rate of the succeeding urea nozzle does not need to be adjusted;
as shown in fig. 3, step S202 includes the following steps (i.e., adjusting the injection rate of the preceding urea nozzle according to the first preceding SCR efficiency, and adjusting the injection rate of the following urea nozzle according to the first following SCR efficiency, including the following steps):
step S2021, when the first previous stage SCR efficiency is less than the first efficiency threshold, increasing the injection rate of the previous stage urea nozzle by a first preset injection correction value to obtain a first previous stage corrected injection rate, and controlling the previous stage urea nozzle to inject urea at the first previous stage corrected injection rate;
specifically, for example, when the first efficiency threshold is 70%, and the first pre-stage SCR efficiency is 70% or less, increasing the injection rate of the pre-stage urea nozzle by a first preset injection correction value to obtain a first pre-stage corrected injection rate, controlling the pre-stage urea nozzle to inject urea at the first pre-stage corrected injection rate, and adjusting the injection rate of the pre-stage urea nozzle may be achieved by adjusting the opening of the pre-stage urea nozzle;
Step S2022, when the first post-stage SCR efficiency is less than the second efficiency threshold, increasing the injection rate of the post-stage urea nozzle by a second preset injection correction value to obtain a first post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea at the first post-stage corrected injection rate.
Specifically, when the first post-stage SCR efficiency is below 70%, increasing the injection rate of the post-stage urea nozzle by a second preset injection correction value to obtain a first post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea by using the first post-stage corrected injection rate, and adjusting the injection rate of the post-stage urea nozzle can be achieved by adjusting the opening of the post-stage urea nozzle; when the lower efficiency of the pre-stage SCR is detected, actively controlling a pre-stage urea nozzle to spray urea; when the lower efficiency of the rear-stage SCR is detected, actively controlling a rear-stage urea nozzle to spray urea;
step S203, after a preset time, obtaining a second pre-stage SCR efficiency of the pre-stage SCR and a second post-stage SCR efficiency of the post-stage SCR, and continuously adjusting at least an injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and/or continuously adjusting at least an injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency.
Specifically, for example, after 5 minutes, the second pre-stage SCR efficiency of the pre-stage SCR and the second post-stage SCR efficiency of the post-stage SCR are obtained, and the injection rate of the pre-stage urea nozzle may be continuously adjusted according to the second pre-stage SCR efficiency; the injection rate of the preceding urea nozzle and the injection rate of the following urea nozzle can be continuously adjusted according to the second preceding SCR efficiency; the injection rate of the post-stage urea nozzle can be continuously adjusted according to the second post-stage SCR efficiency; the injection rate of the rear-stage urea nozzle and the injection rate of the front-stage urea nozzle can be continuously adjusted according to the second rear-stage SCR efficiency; the injection rate of the preceding urea nozzle and the injection rate of the following urea nozzle can be continuously adjusted according to the second preceding SCR efficiency and the second following SCR efficiency;
as shown in fig. 4, at least the injection rate of the preceding urea nozzle is continuously adjusted according to the second preceding SCR efficiency in step S203, including the steps of:
step S301, when the second pre-stage SCR efficiency is greater than the first pre-stage SCR efficiency, of increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea at the second pre-stage corrected injection rate;
Specifically, when the second pre-stage SCR efficiency is greater than the first pre-stage SCR efficiency, it is indicated that the NOx conversion efficiency of the pre-stage SCR is improved, for example, the first pre-stage corrected injection rate is 60, the first preset injection correction value is 10, the injection rate of urea injected from the pre-stage urea nozzle is controlled to be 70, and the second pre-stage corrected injection rate is controlled to be 70;
step S302, when the second pre-stage SCR efficiency is less than or equal to the first pre-stage SCR efficiency, reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, controlling the pre-stage urea nozzle to inject urea at the third pre-stage corrected injection rate, and increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea at the second post-stage corrected injection rate.
Specifically, when the second preceding SCR efficiency is less than or equal to the first preceding SCR efficiency, it is described that the NOx conversion efficiency of the preceding SCR is reduced, for example, the first preceding correction injection rate is 60, the first preset injection correction value is 10, the injection rate of urea injected from the preceding urea nozzle is controlled to be 50, the third preceding correction injection rate is controlled to be 50, for example, the first subsequent correction injection rate is 50, the second preset injection correction value is 10, the injection rate of urea injected from the subsequent urea nozzle is controlled to be 60, and the second subsequent correction injection rate is controlled to be 60; thereby improving the NOx conversion efficiency of the front-stage SCR and the NOx conversion efficiency of the rear-stage SCR; judging whether the efficiency of the pre-stage SCR is improved, if so, maintaining the pre-stage urea nozzle to spray urea, and if not, considering the pre-stage NH 3 The leakage is large, the front-stage urea nozzle is controlled to reduce the spraying, the front-stage urea nozzle is controlled to reach the optimal spraying amount in a closed loop mode, the rear-stage urea nozzle is additionally sprayed, and the tail row is ensured to meet the requirement;
as shown in fig. 5, at least the injection rate of the urea nozzle at the post-stage is continuously adjusted according to the SCR efficiency at the second post-stage in step S203, including the steps of:
step S401, when the second post-stage SCR efficiency is greater than the first post-stage SCR efficiency, of increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a third post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea at the third post-stage corrected injection rate;
specifically, when the second post-stage SCR efficiency is greater than the first post-stage SCR efficiency, it is described that the NOx conversion efficiency of the post-stage SCR is improved, for example, the first post-stage corrected injection rate is 60, the second preset injection correction value is 10, the injection rate of urea injected from the post-stage urea nozzle is controlled to be 70, and the third post-stage corrected injection rate is controlled to be 70;
and step S402, when the second post-stage SCR efficiency is smaller than or equal to the first post-stage SCR efficiency, reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea at the second post-stage corrected injection rate, and increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea at the second pre-stage corrected injection rate.
Specifically, when the second post-stage SCR efficiency is less than or equal to the first post-stage SCR efficiency, it is described that the NOx conversion efficiency of the post-stage SCR is reduced, for example, the first post-stage corrected injection rate is 60, the second preset injection correction value is 10, the injection rate of urea injected from the post-stage urea nozzle is controlled to be 50, the third post-stage corrected injection rate is 50, for example, the first pre-stage corrected injection rate is 60, the first preset injection correction value is 10, the injection rate of urea injected from the pre-stage urea nozzle is controlled to be 70, and the second pre-stage corrected injection rate is controlled to be 70. Judging whether the efficiency of the rear-stage SCR is improved, if so, maintaining the rear-stage urea nozzle to spray urea, and if not, considering the rear-stage NH 3 The leakage is large, the rear-stage urea nozzle is controlled to reduce the spraying, the rear-stage urea nozzle is controlled to reach the optimal spraying amount in a closed loop mode, the front-stage urea nozzle is additionally sprayed, and the tail row is ensured to meet the requirement;
in step S203, at least continuously adjusting the injection rate of the preceding urea nozzle according to the second preceding SCR efficiency, and at least continuously adjusting the injection rate of the succeeding urea nozzle according to the second succeeding SCR efficiency, includes:
Reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by the third pre-stage corrected injection rate when the second pre-stage SCR efficiency is less than or equal to the first pre-stage SCR efficiency and the second post-stage SCR efficiency is less than or equal to the first post-stage SCR efficiency;
when the detection that the efficiency of the front-stage SCR and the rear-stage SCR is low, actively controlling the SCR to enter a low-emission mode (namely by reducing the exhaust emission of an engine), namely actively controlling a front-stage urea nozzle and a rear-stage urea nozzle to reduce the spraying urea to an optimal spraying amount, and reducing the tail emission;
and when the second former-stage SCR efficiency is smaller than or equal to the first former-stage SCR efficiency and the second latter-stage SCR efficiency is smaller than or equal to the first latter-stage SCR efficiency, reducing the first latter-stage corrected injection rate of the latter-stage urea nozzle by the second preset injection correction value to obtain a second latter-stage corrected injection rate, controlling the latter-stage urea nozzle to inject urea by using the second latter-stage corrected injection rate, and controlling an engine to reduce the exhaust gas injection amount of the tail gas end of the engine.
When the detection that the efficiency of the front-stage SCR and the rear-stage SCR is low, the front-stage SCR and the rear-stage SCR are actively controlled to enter a low-emission mode (namely by reducing the exhaust emission of an engine), and the front-stage urea nozzle and the rear-stage urea nozzle are actively controlled to reduce the spraying urea to the optimal spraying amount, so that the tail emission is reduced.
In one embodiment of the present application, controlling the pre-stage urea nozzle to inject urea using the third pre-stage modified injection rate includes:
acquiring an absolute value of a first difference value, wherein the first difference value is a difference value between the second pre-stage SCR efficiency and the first pre-stage SCR efficiency;
for example, the second pre-stage SCR efficiency is 50%, the first pre-stage SCR efficiency is 70%, and the absolute value of the first difference is 20%;
reducing the opening degree of the preceding urea nozzle by a first opening degree under the condition that the absolute value of the first difference value is larger than or equal to a first phase difference threshold value, so that the preceding urea nozzle adopts the third preceding correction injection rate to inject urea;
for example, if the absolute value of the first difference is 20% and the first difference threshold is 15%, the opening degree of the preceding urea nozzle is reduced by a first opening degree, for example, by 10%, so that the preceding urea nozzle injects urea at the third preceding correction injection rate;
And reducing the opening degree of the preceding urea nozzle by a second opening degree when the first difference value is smaller than the first difference threshold value, so that the preceding urea nozzle sprays urea by using the third preceding correction injection rate, and the second opening degree is smaller than the first opening degree.
For example, if the absolute value of the first difference is 10% and the first difference threshold is 15%, the opening of the preceding urea nozzle is reduced by a first opening, for example, by 5%, so that the preceding urea nozzle adopts the third preceding correction injection rate to inject urea, and when the deviation is too large, the opening adjustment amount of the urea nozzle is set to be larger, and when the deviation is not large, the opening adjustment amount of the urea nozzle is set to be smaller, so that the NOx conversion efficiency of the SCR is quickly set to be at an optimal value.
In one embodiment of the present application, controlling the pre-stage urea nozzle to inject urea using the first pre-stage modified injection rate includes:
acquiring an absolute value of a second difference value, wherein the second difference value is a difference value between the first pre-stage SCR efficiency and the first pre-stage SCR efficiency;
for example, the second pre-stage SCR efficiency is 70%, the first pre-stage SCR efficiency is 60%, and the absolute value of the first difference is 10%;
Increasing the opening of the preceding urea nozzle by a third opening under the condition that the absolute value of the second difference is greater than or equal to a second difference threshold value, so that the preceding urea nozzle adopts the first preceding correction injection rate to inject urea;
for example, if the absolute value of the second difference is 10% and the second difference threshold is 8%, the opening degree of the preceding urea nozzle is increased by a third opening degree, for example, by 10%, so that the preceding urea nozzle injects urea at the first preceding correction injection rate.
And increasing the opening degree of the preceding urea nozzle by a fourth opening degree when the absolute value of the second difference value is smaller than the second difference threshold value, so that the preceding urea nozzle sprays urea by using the first preceding correction injection rate, and the fourth opening degree is smaller than the third opening degree.
For example, the absolute value of the two difference values is 10%, and the second difference threshold value is 15%, the opening of the preceding urea nozzle is reduced by a fourth opening, for example, by 5%, so that the preceding urea nozzle adopts the first preceding correction injection rate to inject urea, and when the difference value is too large, the opening adjustment amount of the urea nozzle is set to be larger, and when the difference value is not large, the opening adjustment amount of the urea nozzle is set to be smaller, so that the NOx conversion efficiency of the SCR is quickly set to be at an optimal value.
Through the embodiment, the NOx conversion efficiency of the front-stage SCR and the rear-stage SCR are respectively obtained for consideration, so that the injection quantity of the urea nozzle can be adjusted in a targeted manner, the NOx conversion efficiency of the SCR system is effectively improved, and the problem that the NOx conversion efficiency of the SCR system is lower in the prior art is solved.
In summary, for the SCR system, after detecting that the pre-stage SCR efficiency is low, actively spraying urea to confirm the reason of the low pre-stage SCR efficiency, and coordinately controlling the spraying amounts of the pre-stage urea nozzle and the post-stage urea nozzle according to the pre-stage SCR efficiency.
And aiming at the SCR system, after the low efficiency of the rear-stage SCR is detected, actively spraying urea to confirm the reason of the low efficiency of the rear-stage SCR, and coordinately controlling the spraying quantity of the front-stage urea nozzle and the rear-stage urea nozzle according to the efficiency of the second-stage SCR.
And aiming at the SCR system, after the efficiency of the front-stage SCR and the rear-stage SCR is low, actively spraying urea to confirm the reason of the low SCR efficiency, and controlling the spraying quantity of the front-stage urea nozzle and the rear-stage urea nozzle by controlling the mode of entering a low-primary-emission mode according to the coordinated control of the SCR efficiency.
In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the SCR efficiency control method of the present application will be described in detail below with reference to specific embodiments.
The embodiment relates to a specific control method of SCR efficiency, as shown in fig. 6, including the following steps:
step S1: obtaining conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR, and obtaining first front-stage SCR efficiency and first rear-stage SCR efficiency;
step S2: under the condition that the first pre-stage SCR efficiency is smaller than a first efficiency threshold, increasing the injection rate of the pre-stage urea nozzle by a first preset injection correction value to obtain a first pre-stage correction injection rate, controlling the pre-stage urea nozzle to inject urea by adopting the first pre-stage correction injection rate, and then entering step S3; under the condition that the first pre-stage SCR efficiency is smaller than the first efficiency threshold, acquiring the conversion efficiency of nitrogen oxides NOx of the pre-stage SCR again after 1min (which can be 0 to 60min at any time) (namely, entering step S1 later); under the condition that the first post-stage SCR efficiency is smaller than a second efficiency threshold, increasing the injection rate of the post-stage urea nozzle by a second preset injection correction value to obtain a first post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea by adopting the first post-stage corrected injection rate, and then entering step S3; under the condition that the first post-stage SCR efficiency is greater than or equal to the second efficiency threshold, acquiring the conversion efficiency of nitrogen oxides NOx of the post-stage SCR again after 1min (which can be 0 to 60min at any time) (namely, entering step S1 later);
Step S3: when the second pre-stage SCR efficiency is greater than the first pre-stage SCR efficiency, increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea at the second pre-stage corrected injection rate (i.e., increasing the urea injection amount of the pre-stage urea nozzle); reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, controlling the pre-stage urea nozzle to inject urea at the third pre-stage corrected injection rate, and increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea at the second post-stage corrected injection rate (i.e., reducing the urea injection amount of the pre-stage urea nozzle and increasing the urea injection amount of the post-stage urea nozzle);
When the second post-stage SCR efficiency is greater than the first post-stage SCR efficiency, increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a third post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea at the third post-stage corrected injection rate (i.e., increasing the urea injection amount of the post-stage urea nozzle); reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea at the second post-stage corrected injection rate, and increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, controlling the pre-stage urea nozzle to inject urea at the second pre-stage corrected injection rate (i.e., reducing the urea injection amount of the post-stage urea nozzle and increasing the urea injection amount of the pre-stage urea nozzle);
when the second preceding SCR efficiency is less than or equal to the first preceding SCR efficiency and the second succeeding SCR efficiency is less than or equal to the first succeeding SCR efficiency, the process proceeds to step S4;
Step S4: reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by adopting the third pre-stage corrected injection rate; and reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea by using the second post-stage corrected injection rate, and controlling the engine to reduce the exhaust gas injection amount of the exhaust gas end of the engine (namely reducing the urea injection amounts of the pre-stage urea nozzle and the post-stage urea nozzle and reducing the exhaust gas injection amount of the exhaust gas end of the engine).
It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is illustrated in the flowcharts, in some cases the steps illustrated or described may be performed in an order other than that illustrated herein.
The embodiment of the application also provides a control device for SCR efficiency, and it should be noted that the control device for SCR efficiency in the embodiment of the application may be used to execute the control method for SCR efficiency provided in the embodiment of the application. The device is used for realizing the above embodiments and preferred embodiments, and is not described in detail. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. While the means described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.
The following describes a control device for SCR efficiency provided in the embodiment of the present application.
Fig. 7 is a block diagram of a control device for SCR efficiency according to an embodiment of the present application. As shown in fig. 7, the apparatus includes an acquisition unit 71, a first adjustment unit 72, and a second adjustment unit 73; the obtaining unit 71 is configured to obtain conversion efficiency of nitrogen oxides NOx of the preceding SCR and the succeeding SCR, and obtain a first preceding SCR efficiency and a first succeeding SCR efficiency; the first adjusting unit 72 is configured to adjust an injection rate of the urea nozzle at the previous stage according to the SCR efficiency at the first previous stage, and adjust an injection rate of the urea nozzle at the next stage according to the SCR efficiency at the first next stage; the second adjusting unit 73 is configured to obtain a second pre-SCR efficiency of the pre-SCR and a second post-SCR efficiency of the post-SCR after a preset time, and at least continuously adjust the injection rate of the pre-urea nozzle according to the second pre-SCR efficiency, and/or at least continuously adjust the injection rate of the post-urea nozzle according to the second post-SCR efficiency.
In the device, the NOx conversion efficiency of the front-stage SCR and the rear-stage SCR are respectively obtained for consideration, so that the injection quantity of the urea nozzle can be adjusted in a targeted manner, the NOx conversion efficiency of the SCR system is effectively improved, and the problem that the NOx conversion efficiency of the SCR system is lower in the prior art is solved.
In an embodiment of the present application, the first adjusting unit includes a first adjusting module and a second adjusting module, where the first adjusting module is configured to increase the injection rate of the preceding urea nozzle by a first preset injection correction value to obtain a first preceding corrected injection rate, and control the preceding urea nozzle to inject urea using the first preceding corrected injection rate when the first preceding SCR efficiency is less than a first efficiency threshold; the second adjustment module is configured to increase the injection rate of the urea nozzle at the subsequent stage by a second preset injection correction value to obtain a first corrected injection rate at the subsequent stage when the SCR efficiency at the first subsequent stage is less than a second efficiency threshold, and control the urea nozzle at the subsequent stage to inject urea at the first corrected injection rate.
In an embodiment of the present application, the second adjusting unit includes a third adjusting module and a fourth adjusting module, where the third adjusting module is configured to increase the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and control the pre-stage urea nozzle to inject urea using the second pre-stage corrected injection rate when the second pre-stage SCR efficiency is greater than the first pre-stage SCR efficiency; the fourth adjustment module is configured to reduce the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate when the second pre-stage SCR efficiency is less than or equal to the first pre-stage SCR efficiency, control the pre-stage urea nozzle to inject urea at the third pre-stage corrected injection rate, and increase the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, and control the post-stage urea nozzle to inject urea at the second post-stage corrected injection rate.
In an embodiment of the present application, the second adjusting unit includes a fifth adjusting module and a sixth adjusting module, where the fifth adjusting module is configured to increase the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a third post-stage corrected injection rate, and control the post-stage urea nozzle to inject urea at the third post-stage corrected injection rate when the second post-stage SCR efficiency is greater than the first post-stage SCR efficiency; the sixth adjustment module is configured to reduce the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate when the second post-stage SCR efficiency is less than or equal to the first post-stage SCR efficiency, control the post-stage urea nozzle to inject urea at the second post-stage corrected injection rate, and increase the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and control the pre-stage urea nozzle to inject urea at the second pre-stage corrected injection rate.
In an embodiment of the present application, the second adjusting unit includes a seventh adjusting module and an eighth adjusting module, where the seventh adjusting module is configured to reduce the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, and control the pre-stage urea nozzle to inject urea using the third pre-stage corrected injection rate when the second pre-stage SCR efficiency is less than or equal to the first pre-stage SCR efficiency and the second post-stage SCR efficiency is less than or equal to the first post-stage SCR efficiency; the eighth adjustment module is configured to reduce the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, control the post-stage urea nozzle to inject urea using the second post-stage corrected injection rate, and control the engine to reduce an exhaust emission of an exhaust end of the engine when the second pre-stage SCR efficiency is less than or equal to the first pre-stage SCR efficiency and the second post-stage SCR efficiency is less than or equal to the first post-stage SCR efficiency.
In an embodiment of the present application, the fourth adjustment module includes a first obtaining sub-module, a first adjustment sub-module, and a second adjustment sub-module, where the first obtaining sub-module is configured to obtain an absolute value of a first difference, where the first difference is a difference between the second preceding-stage SCR efficiency and the first preceding-stage SCR efficiency; the first adjusting submodule is used for reducing the opening of the preceding urea nozzle by a first opening under the condition that the absolute value of the first difference value is larger than or equal to a first phase difference threshold value, so that the preceding urea nozzle adopts the third preceding correction injection rate to inject urea; the second adjustment submodule is used for reducing the opening of the preceding urea nozzle by a second opening when the first difference value is smaller than the first phase difference threshold value so that the preceding urea nozzle adopts the third preceding correction injection rate to inject urea, and the second opening is smaller than the first opening.
In an embodiment of the present application, the first adjustment module includes a second obtaining sub-module, a third adjustment sub-module, and a fourth adjustment sub-module, where the second obtaining sub-module is configured to obtain an absolute value of a second difference, where the second difference is a difference between the first pre-SCR efficiency and the first pre-SCR efficiency; the third adjusting submodule is used for increasing the opening of the preceding urea nozzle by a third opening under the condition that the absolute value of the second difference value is larger than or equal to a second difference threshold value so that the preceding urea nozzle adopts the first preceding correction injection rate to inject urea; and the fourth adjusting submodule is used for increasing the opening of the preceding urea nozzle by a fourth opening when the absolute value of the second difference value is smaller than the second phase difference threshold value so that the preceding urea nozzle adopts the first preceding correction injection rate to inject urea, and the fourth opening is smaller than the third opening.
The SCR efficiency control device includes a processor and a memory, wherein the acquisition unit, the first adjustment unit, the second adjustment unit, and the like are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions. The modules are all located in the same processor; alternatively, the above modules may be located in different processors in any combination.
The processor includes a kernel, and the kernel fetches the corresponding program unit from the memory. The inner core can be provided with one or more than one, and the problem of low NOx conversion efficiency of the SCR system in the prior art is solved by adjusting the parameters of the inner core.
The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), among other forms in computer readable media, the memory including at least one memory chip.
The embodiment of the invention provides a computer readable storage medium, which comprises a stored program, wherein the program is used for controlling equipment where the computer readable storage medium is located to execute the control method of SCR efficiency.
The embodiment of the invention provides a processor, which is used for running a program, wherein the control method of the SCR efficiency is executed when the program runs.
The embodiment of the invention provides equipment, which comprises a processor, a memory and a program stored in the memory and capable of running on the processor, wherein the processor realizes at least the following steps when executing the program: obtaining conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR, and obtaining first front-stage SCR efficiency and first rear-stage SCR efficiency; adjusting the injection rate of a pre-stage urea nozzle according to the first pre-stage SCR efficiency, and adjusting the injection rate of a post-stage urea nozzle according to the first post-stage SCR efficiency; after a preset time, obtaining the second pre-stage SCR efficiency of the pre-stage SCR and the second post-stage SCR efficiency of the post-stage SCR, and continuously adjusting at least the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and/or continuously adjusting at least the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency. The device herein may be a server, PC, PAD, cell phone, etc.
The present application also provides a computer program product adapted to perform a program initialized with at least the following method steps when executed on a data processing device: obtaining conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR, and obtaining first front-stage SCR efficiency and first rear-stage SCR efficiency; adjusting the injection rate of a pre-stage urea nozzle according to the first pre-stage SCR efficiency, and adjusting the injection rate of a post-stage urea nozzle according to the first post-stage SCR efficiency; after a preset time, obtaining the second pre-stage SCR efficiency of the pre-stage SCR and the second post-stage SCR efficiency of the post-stage SCR, and continuously adjusting at least the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and/or continuously adjusting at least the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency.
The present application provides an SCR system, as shown in fig. 8 (fig. 8 does not show a controller and an engine), where the SCR system includes a pre-SCR 110, a post-SCR 120, a controller, a pre-urea nozzle 130 and a post-urea nozzle 140, where the pre-SCR 110 is used to communicate with an exhaust end of the engine through a first pipe, the pre-urea nozzle 130 is installed inside the first pipe, the pre-SCR 110 is communicated with the post-SCR 120 through a second pipe, the post-urea nozzle 140 is installed inside the second pipe, the controller is respectively in communication with the pre-urea nozzle 130 and the post-urea nozzle 140, the controller is used to communicate with the engine, and the controller is also used to execute any one of the SCR efficiency control methods. The connection sequence and manner of the first NOx sensor 210, the first temperature sensor 230, the front DOC240, the front ASC250, the second NOx sensor 260, the second temperature sensor 270, the HC injector 280, the rear DOC290, the DPF220, the rear ASC310, the third NOx sensor 320, and the third temperature sensor 330 are shown in fig. 8, and will not be described herein, wherein the HC injector is a separate injector for injecting diesel for regenerating the lift exhaust temperature.
It will be appreciated by those skilled in the art that the modules or steps of the invention described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may be implemented in program code executable by computing devices, so that they may be stored in a storage device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than that shown or described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.
The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.
Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.
From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:
1) According to the control method of the SCR efficiency, the NOx conversion efficiency of the front-stage SCR and the NOx conversion efficiency of the rear-stage SCR are respectively obtained to be considered, so that the injection quantity of the urea nozzle can be adjusted in a targeted mode, the NOx conversion efficiency of the SCR system is effectively improved, and the problem that the NOx conversion efficiency of the SCR system is low in the prior art is solved.
2) According to the SCR efficiency control device, the NOx conversion efficiency of the front-stage SCR and the NOx conversion efficiency of the rear-stage SCR are respectively obtained to be considered, so that the injection quantity of the urea nozzle can be adjusted in a targeted mode, the NOx conversion efficiency of the SCR system is effectively improved, and the problem that the NOx conversion efficiency of the SCR system is low in the prior art is solved.
The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims (10)

1. A control method for dual stage SCR efficiency, comprising:
obtaining conversion efficiency of nitrogen oxides NOx of a front-stage SCR and a rear-stage SCR, and obtaining first front-stage SCR efficiency and first rear-stage SCR efficiency;
adjusting the injection rate of a front-stage urea nozzle according to the first front-stage SCR efficiency, and adjusting the injection rate of a rear-stage urea nozzle according to the first rear-stage SCR efficiency;
after a preset time, obtaining second pre-stage SCR efficiency of the pre-stage SCR and second post-stage SCR efficiency of the post-stage SCR, and at least continuously adjusting the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency, and/or at least continuously adjusting the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency.
2. The method of claim 1, wherein adjusting the injection rate of the pre-stage urea nozzle based on the first pre-stage SCR efficiency and adjusting the injection rate of the post-stage urea nozzle based on the first post-stage SCR efficiency comprises:
Under the condition that the first pre-stage SCR efficiency is smaller than a first efficiency threshold, increasing the injection rate of the pre-stage urea nozzle by a first preset injection correction value to obtain a first pre-stage correction injection rate, and controlling the pre-stage urea nozzle to inject urea by adopting the first pre-stage correction injection rate;
and under the condition that the first post-stage SCR efficiency is smaller than a second efficiency threshold, increasing the injection rate of the post-stage urea nozzle by a second preset injection correction value to obtain a first post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea by adopting the first post-stage corrected injection rate.
3. The method of claim 2, wherein at least continuing to adjust the injection rate of the pre-stage urea nozzle based on the second pre-stage SCR efficiency comprises:
increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value under the condition that the second pre-stage SCR efficiency is larger than the first pre-stage SCR efficiency to obtain a second pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by adopting the second pre-stage corrected injection rate;
and when the second pre-stage SCR efficiency is smaller than or equal to the first pre-stage SCR efficiency, reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, controlling the pre-stage urea nozzle to inject urea by adopting the third pre-stage corrected injection rate, and increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea by adopting the second post-stage corrected injection rate.
4. The method of claim 2, wherein continuing to adjust at least the injection rate of the post-stage urea nozzle based on the second post-stage SCR efficiency comprises:
increasing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value under the condition that the second post-stage SCR efficiency is greater than the first post-stage SCR efficiency to obtain a third post-stage corrected injection rate, and controlling the post-stage urea nozzle to inject urea by adopting the third post-stage corrected injection rate;
and when the second post-stage SCR efficiency is smaller than or equal to the first post-stage SCR efficiency, reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate, controlling the post-stage urea nozzle to inject urea by adopting the second post-stage corrected injection rate, and increasing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a second pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by adopting the second pre-stage corrected injection rate.
5. The method of claim 2, wherein continuing to adjust at least the injection rate of the pre-stage urea nozzle based on the second pre-stage SCR efficiency, and continuing to adjust at least the injection rate of the post-stage urea nozzle based on the second post-stage SCR efficiency, comprises:
reducing the first pre-stage corrected injection rate of the pre-stage urea nozzle by the first preset injection correction value to obtain a third pre-stage corrected injection rate, and controlling the pre-stage urea nozzle to inject urea by the third pre-stage corrected injection rate under the condition that the second pre-stage SCR efficiency is smaller than or equal to the first pre-stage SCR efficiency and the second post-stage SCR efficiency is smaller than or equal to the first post-stage SCR efficiency;
and reducing the first post-stage corrected injection rate of the post-stage urea nozzle by the second preset injection correction value to obtain a second post-stage corrected injection rate under the condition that the second pre-stage SCR efficiency is smaller than or equal to the first efficiency threshold and the second post-stage SCR efficiency is smaller than or equal to the second efficiency threshold, controlling the post-stage urea nozzle to adopt the second post-stage corrected injection rate to inject urea, and controlling an engine to reduce the exhaust gas injection quantity of the tail gas end of the engine.
6. A method according to claim 3, wherein controlling the pre-stage urea nozzle to inject urea with the third pre-stage modified injection rate comprises:
acquiring an absolute value of a first difference value, wherein the first difference value is a difference value between the second front-stage SCR efficiency and the first front-stage SCR efficiency;
reducing the opening degree of the preceding-stage urea nozzle by a first opening degree under the condition that the absolute value of the first difference value is larger than or equal to a first phase difference threshold value, so that the preceding-stage urea nozzle adopts the third preceding-stage corrected injection rate to inject urea;
and under the condition that the first difference value is smaller than the first phase difference threshold value, reducing the opening degree of the pre-stage urea nozzle by a second opening degree so that the pre-stage urea nozzle adopts the third pre-stage correction injection rate to inject urea, wherein the second opening degree is smaller than the first opening degree.
7. The method of any one of claims 2 to 6, wherein controlling the pre-stage urea nozzle to inject urea with the first pre-stage modified injection rate comprises:
acquiring an absolute value of a second difference value, wherein the second difference value is a difference value between the first pre-stage SCR efficiency and the first pre-stage SCR efficiency;
Increasing the opening of the pre-stage urea nozzle by a third opening under the condition that the absolute value of the second difference value is larger than or equal to a second difference threshold value, so that the pre-stage urea nozzle adopts the first pre-stage correction injection rate to inject urea;
and under the condition that the absolute value of the second difference value is smaller than the second phase difference threshold value, increasing the opening of the pre-stage urea nozzle by a fourth opening so that the pre-stage urea nozzle adopts the first pre-stage correction injection rate to inject urea, wherein the fourth opening is smaller than the third opening.
8. A control device for SCR efficiency, comprising:
the acquisition unit is used for acquiring conversion efficiency of nitrogen oxides NOx of the front-stage SCR and the rear-stage SCR to obtain first front-stage SCR efficiency and first rear-stage SCR efficiency;
the first adjusting unit is used for adjusting the injection rate of the front-stage urea nozzle according to the first front-stage SCR efficiency and adjusting the injection rate of the rear-stage urea nozzle according to the first rear-stage SCR efficiency;
and the second adjusting unit is used for acquiring the second pre-stage SCR efficiency of the pre-stage SCR and the second post-stage SCR efficiency of the post-stage SCR after the preset time, and at least continuously adjusting the injection rate of the pre-stage urea nozzle according to the second pre-stage SCR efficiency and/or at least continuously adjusting the injection rate of the post-stage urea nozzle according to the second post-stage SCR efficiency.
9. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a stored program, wherein the program, when run, controls a device in which the computer-readable storage medium is located to perform the SCR efficiency control method according to any one of claims 1 to 7.
10. An SCR system, comprising: a pre-SCR, a post-SCR, a controller, a pre-urea nozzle and a post-urea nozzle, wherein the pre-SCR is used for communicating with a tail gas end of an engine through a first pipeline, the pre-urea nozzle is internally installed in the first pipeline, the pre-SCR is communicated with the post-SCR through a second pipeline, the post-urea nozzle is internally installed in the second pipeline, the controller is respectively communicated with the pre-urea nozzle and the post-urea nozzle, the controller is used for communicating with the engine, and the controller is further used for executing the SCR efficiency control method according to any one of claims 1 to 7.
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