CN113398757A - Simple ammonia injection control method and device - Google Patents

Simple ammonia injection control method and device Download PDF

Info

Publication number
CN113398757A
CN113398757A CN202110707762.5A CN202110707762A CN113398757A CN 113398757 A CN113398757 A CN 113398757A CN 202110707762 A CN202110707762 A CN 202110707762A CN 113398757 A CN113398757 A CN 113398757A
Authority
CN
China
Prior art keywords
concentration
outlet
nox
scr reactor
value
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202110707762.5A
Other languages
Chinese (zh)
Other versions
CN113398757B (en
Inventor
熊辉
黄卫剑
李锋
朱亚清
庞志强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China Southern Power Grid Power Technology Co Ltd
Original Assignee
China Southern Power Grid Power Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China Southern Power Grid Power Technology Co Ltd filed Critical China Southern Power Grid Power Technology Co Ltd
Priority to CN202110707762.5A priority Critical patent/CN113398757B/en
Publication of CN113398757A publication Critical patent/CN113398757A/en
Application granted granted Critical
Publication of CN113398757B publication Critical patent/CN113398757B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8631—Processes characterised by a specific device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/346—Controlling the process
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/90—Injecting reactants
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

The application discloses a simple ammonia injection control method and a simple ammonia injection control device, wherein the method comprises the following steps: obtaining a target limit value of NOx concentration at an outlet of the SCR reactor by adopting a preset NFC master controller according to the target value and the measured value deviation of the NOx concentration of the clean flue gas; calculating a static deviation correction value according to the measured value of the NOx at the outlet of the reactor and a target limit value; obtaining a corrected value of the concentration change rate according to the measured value of the NOx at the outlet of the reactor and a target limit value; acquiring an ammonia injection valve control instruction by adopting a preset NFC secondary controller according to a NOx measured value at the outlet of the reactor, a target limit value thereof, a static deviation correction value and a concentration change rate correction value; and controlling the ammonia spraying amount of the ammonia spraying control valve through the ammonia spraying control instruction. The application solves the technical problems that the existing SCR control system is poor in ammonia spraying self-adaptive control effect and easy to cause ammonia spraying excess due to the fact that a fixed ammonia-nitrogen ratio is adopted, manual intervention is needed in system work, and ammonia escape is easy to occur.

Description

Simple ammonia injection control method and device
Technical Field
The application relates to the technical field of ammonia injection, in particular to a simple ammonia injection control method and device.
Background
With the increasing environmental protection situation in China, the problem of pollutant emission of thermal power plants is more and more emphasized. Nitrogen oxides (NOx for short) are a main pollutant discharged by thermal power plants, and China has strict index requirements on NOx discharge concentration. As a flue gas denitration method with high denitration efficiency and low ammonia escape rate, Selective Catalytic Reduction (SCR) technology has become the choice of many thermal power plants.
Most power plant SCR control systems at present adopt the conventional PID control strategy of fixed ammonia nitrogen molar ratio or fixed NOx mass concentration in the flue gas of SCR reactor outlet, it is poor to spout ammonia automatic control effect, especially when the coal pulverizer is started and stopped to unit low-load and variable load, the fluctuation of NOx is big and the oscillation is difficult to be stable, in order to avoid NOx emission concentration to exceed standard, often need manual intervention, it is excessive to easily cause spouting ammonia, a large amount of ammonia escape appears, so long-term operation will lead to the air preheater to block up, make the operating performance of whole deNOx systems receive obvious influence.
Disclosure of Invention
The application provides a simple ammonia injection control method and device, which are used for solving the technical problems that the existing SCR control system adopts a fixed ammonia-nitrogen ratio, so that the ammonia injection self-adaptive control effect is poor, excessive ammonia injection is easily caused, the system needs manual intervention during working, and ammonia escape is easily caused.
In view of the above, the first aspect of the present application provides a very simple ammonia injection control method, comprising:
when the time that the deviation of the concentration of the NOx in the clean flue gas exceeds the first outlet concentration limit value is longer than first preset time, a preset NFC main controller is adopted to control the concentration of the NOx according to the measured value of the concentration of the NOx in the clean flue gas, and the target limit value of the concentration of the NOx at the outlet of the SCR reactor is obtained;
when the time that the deviation of the NOx concentration at the outlet of the SCR reactor exceeds a second outlet concentration limit value is longer than a second preset time, calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
carrying out NOx concentration analysis according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor to obtain a corrected value of the NOx concentration change rate at the outlet of the SCR reactor;
acquiring an ammonia injection valve control instruction by adopting a preset NFC secondary controller according to the measured value of the concentration of the NOx at the outlet of the SCR reactor, the target limit value of the concentration of the NOx at the outlet of the SCR reactor, the static deviation correction value of the concentration of the NOx at the outlet of the SCR reactor and the correction value of the concentration change rate of the NOx at the outlet of the SCR reactor;
and controlling the opening degree of the ammonia spraying control valve through the ammonia spraying control instruction so as to control the change of the ammonia spraying amount.
Optionally, when the time that the deviation of the net flue gas NOx concentration exceeds the first outlet concentration limit value is longer than a first preset time, performing NOx concentration control by using a preset NFC master controller according to the net flue gas NOx concentration measurement value to obtain an outlet NOx concentration target limit value of the SCR reactor, including:
calculating the concentration deviation of the net smoke NOx according to the net smoke NOx concentration measured value and the net smoke NOx concentration target value;
when the time that the concentration deviation of the clean flue gas NOx exceeds the first outlet concentration limit value is longer than a first preset time, multiplying the concentration deviation of the clean flue gas NOx by a first preset gain coefficient to obtain a static deviation correction value of the concentration of the clean flue gas NOx;
calculating an initial limit value of the concentration of NOx at the outlet of the SCR reactor by adopting a preset NFC master controller according to the measured value of the concentration of NOx in the clean flue gas and the target value of the concentration of NOx in the clean flue gas;
and superposing the net smoke NOx concentration static deviation correction value on the SCR reactor outlet NOx concentration initial limit value to obtain the SCR reactor outlet NOx concentration target limit value.
Optionally, when the time that the deviation of the NOx concentration at the outlet of the SCR reactor exceeds the second outlet concentration limit is longer than a second preset time, calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit of the NOx concentration at the outlet of the SCR reactor, including:
calculating the NOx concentration deviation at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
and when the time that the concentration deviation of the NOx at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time, multiplying the concentration deviation of the NOx at the outlet of the SCR reactor by a second preset gain coefficient to obtain a static deviation correction value of the concentration of the NOx at the outlet of the SCR reactor.
Optionally, the analyzing the NOx concentration according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor to obtain a corrected value of the NOx concentration change rate at the outlet of the SCR reactor includes:
calculating the NOx concentration change rate at the outlet of the SCR reactor according to the NOx concentration measured value at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
if the concentration deviation of the NOx at the outlet of the SCR reactor exceeds a first concentration upper limit value and the change rate of the NOx at the outlet of the SCR reactor exceeds a second concentration upper limit value, controlling the change rate correction value of the NOx at the outlet of the SCR reactor to increase from zero to a first preset setting value at a first preset rate;
if the deviation of the concentration of the NOx at the outlet of the SCR reactor is lower than a first concentration lower limit value, and the change rate of the concentration of the NOx at the outlet of the SCR reactor is lower than a second concentration lower limit value, controlling the change rate correction value of the concentration of the NOx at the outlet of the SCR reactor to increase from zero to a second preset setting value at a second preset rate;
and if the deviation of the concentration of the NOx at the outlet of the SCR reactor is between the first concentration upper limit value and the first concentration lower limit value, and/or the change rate of the concentration of the NOx at the outlet of the SCR reactor is between the second concentration upper limit value and the second concentration lower limit value, controlling the corrected value of the NOx concentration change rate at the outlet of the SCR reactor to be zero.
Optionally, the obtaining, by using the preset NFC secondary controller, the ammonia injection gating control instruction according to the measured value of the NOx concentration at the outlet of the SCR reactor, the target limit value of the NOx concentration at the outlet of the SCR reactor, the static deviation correction value of the NOx concentration at the outlet of the SCR reactor, and the correction value of the NOx concentration change rate at the outlet of the SCR reactor includes:
performing NFC control by adopting a preset NFC secondary controller according to the measured value of the concentration of the NOx at the outlet of the SCR reactor and the target limit value of the concentration of the NOx at the outlet of the SCR reactor to obtain an initial control instruction of an ammonia spraying throttle;
and superposing the static deviation correction value of the NOx concentration at the outlet of the SCR reactor and the change rate correction value of the NOx concentration at the outlet of the SCR reactor to the initial control instruction of the ammonia injection regulating valve to obtain the control instruction of the ammonia injection regulating valve.
Optionally, the controlling the opening degree of the ammonia injection valve according to the ammonia injection valve control instruction, so as to control the change of the ammonia injection amount, before further comprising:
when the sensor is in the purging mode, command receiving to the preset NFC secondary controller is suspended through a preset switcher, and command receiving to the preset NFC secondary controller is resumed after the purging mode is finished.
In a second aspect, the present application provides a simplified ammonia injection control apparatus, comprising:
the target limit control module is used for controlling the concentration of the NOx by adopting a preset NFC main controller according to the measured value of the concentration of the NOx in the clean flue gas when the time that the concentration deviation of the NOx in the clean flue gas exceeds the first outlet concentration limit value is longer than a first preset time, so that the target limit of the concentration of the NOx in the outlet of the SCR reactor is obtained;
the static deviation calculation module is used for calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor when the time that the NOx concentration deviation at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time;
the concentration change rate calculation module is used for carrying out NOx concentration analysis according to the SCR reactor outlet NOx concentration measured value and the SCR reactor outlet NOx concentration target limit value to obtain an SCR reactor outlet NOx concentration change rate correction value;
the ammonia injection instruction generating module is used for acquiring an ammonia injection valve control instruction according to the measured value of the NOx concentration at the outlet of the SCR reactor, the target limit value of the NOx concentration at the outlet of the SCR reactor, the static deviation correction value of the NOx concentration at the outlet of the SCR reactor and the correction value of the NOx concentration change rate at the outlet of the SCR reactor by adopting a preset NFC secondary controller;
and the ammonia spraying control module is used for controlling the opening degree of the ammonia spraying control valve through the ammonia spraying control instruction so as to control the change of the ammonia spraying amount.
Optionally, the target limit control module includes:
the first concentration deviation calculation submodule is used for calculating the net flue gas NOx concentration deviation according to the net flue gas NOx concentration measured value and the net flue gas NOx concentration target value;
the first deviation correction calculation submodule is used for multiplying the net flue gas NOx concentration deviation by a first preset gain coefficient when the time that the net flue gas NOx concentration deviation exceeds a first outlet concentration limit value is longer than a first preset time to obtain a net flue gas NOx concentration static deviation correction value;
the concentration initial limit value calculation submodule is used for calculating an SCR reactor outlet NOx concentration initial limit value according to the net flue gas NOx concentration measured value and the net flue gas NOx concentration target value by adopting a preset NFC main controller;
and the superposition correction processing submodule is used for superposing the net flue gas NOx concentration static deviation correction value on the SCR reactor outlet NOx concentration initial limit value to obtain the SCR reactor outlet NOx concentration target limit value.
Optionally, the static deviation calculating module is specifically configured to:
the second concentration deviation calculation submodule is used for calculating the NOx concentration deviation at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
and the second deviation correction calculation submodule is used for multiplying the NOx concentration deviation at the outlet of the SCR reactor by a second preset gain coefficient when the time that the NOx concentration deviation at the outlet of the SCR reactor exceeds a second outlet concentration limit value is longer than a second preset time to obtain a static deviation correction value of the NOx concentration at the outlet of the SCR reactor.
Optionally, the module for calculating the concentration change rate includes:
the change rate calculation submodule is used for calculating the NOx concentration change rate at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
the first judgment sub-module is used for controlling the NOx concentration change rate correction value at the outlet of the SCR reactor to increase from zero to a first preset setting value at a first preset rate if the concentration deviation of the NOx at the outlet of the SCR reactor exceeds a first concentration upper limit value and the NOx concentration change rate at the outlet of the SCR reactor exceeds a second concentration upper limit value;
the second judgment sub-module is used for controlling the NOx concentration change rate correction value at the outlet of the SCR reactor to increase from zero to a second preset setting value at a second preset rate if the deviation of the NOx concentration at the outlet of the SCR reactor is lower than a first concentration lower limit value and the NOx concentration change rate at the outlet of the SCR reactor is lower than a second concentration lower limit value;
and the third judgment sub-module is used for controlling the corrected value of the NOx concentration change rate at the outlet of the SCR reactor to be zero if the deviation of the NOx concentration at the outlet of the SCR reactor is between the first concentration upper limit value and the first concentration lower limit value and/or the NOx concentration change rate at the outlet of the SCR reactor is between the second concentration upper limit value and the second concentration lower limit value.
According to the technical scheme, the embodiment of the application has the following advantages:
the application provides a simple ammonia injection control method, which comprises the following steps: when the time that the deviation of the concentration of the NOx in the clean flue gas exceeds the first outlet concentration limit value is longer than first preset time, a preset NFC main controller is adopted to control the concentration of the NOx according to the measured value of the concentration of the NOx in the clean flue gas, and the target limit value of the concentration of the NOx at the outlet of the SCR reactor is obtained; when the time that the NOx concentration deviation of the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than second preset time, calculating a static deviation correction value of the NOx concentration of the outlet of the SCR reactor according to the measured value of the NOx concentration of the outlet of the SCR reactor and the target limit value of the NOx concentration of the outlet of the SCR reactor; carrying out NOx concentration analysis according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor to obtain a corrected value of the NOx concentration change rate at the outlet of the SCR reactor; acquiring an ammonia injection valve control instruction by adopting a preset NFC secondary controller according to the measured value of the concentration of NOx at the outlet of the SCR reactor, the target limit value of the concentration of NOx at the outlet of the SCR reactor, the static deviation correction value of the concentration of NOx at the outlet of the SCR reactor and the correction value of the concentration change rate of NOx at the outlet of the SCR reactor; and the opening degree of the ammonia spraying control valve is controlled through the ammonia spraying control instruction, so that the change of the ammonia spraying amount is controlled.
According to the extremely simple ammonia injection control method, NFC is selected in the controller, the control performance of NOx emission concentration is improved to a great extent, and the NFC has good adjustability and is convenient to use and master; in addition, when the concentration deviation of NOx at the outlet of the SCR reactor exceeds the concentration limit value and reaches a certain time, a static NOx concentration deviation correction value and a NOx concentration change rate correction value can be added into a signal obtained by the NFC controller, an ammonia injection valve control command generated through flexible NFC control can adaptively control the opening size of the ammonia injection valve, external disturbance of the system is effectively overcome, the stability of the system can be guaranteed through an accurate control mode, manual intervention is not needed, and ammonia escape cannot be caused through the influence of feed-forward quantity. Therefore, the technical problems that the existing SCR control system is poor in ammonia spraying self-adaptive control effect and easy to cause ammonia spraying excess due to the fact that a fixed ammonia-nitrogen ratio is adopted, manual intervention is needed in system work, and ammonia escape is easy to occur can be solved.
Drawings
FIG. 1 is a schematic flow chart of a simplified ammonia injection control method provided by an embodiment of the present application;
FIG. 2 is a schematic structural diagram of a simplified ammonia injection control device according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a calculation process of a net flue gas/net flue gas NOx concentration static deviation correction value according to an embodiment of the present disclosure;
FIG. 4 is a schematic diagram illustrating a process of calculating a static deviation correction value of NOx concentration at an outlet of an SCR reactor according to an embodiment of the present disclosure;
FIG. 5 is a schematic diagram illustrating a process for calculating a corrected value of a NOx concentration change rate at an outlet of an SCR reactor according to an embodiment of the present disclosure;
FIG. 6 is a simplified flow diagram of an ammonia injection control system according to an embodiment of the present application;
FIG. 7 is a simplified flow chart of an ammonia injection control system with the addition of a switch according to an embodiment of the present disclosure.
Detailed Description
In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
For ease of understanding, referring to fig. 1, the present application provides a simplified ammonia injection control method, comprising:
and 101, when the time that the deviation of the concentration of the NOx in the clean flue gas exceeds the first outlet concentration limit value is longer than a first preset time, carrying out NOx concentration control by adopting a preset NFC main controller according to the measured value of the concentration of the NOx in the clean flue gas to obtain a target limit value of the concentration of the NOx at the outlet of the SCR reactor.
The flue gas at the outlet of the boiler needs to be discharged through a long pipeline after the flue gas passes through the reactor for the selective catalytic reduction reaction, so the emission index of the flue gas outlet of the pipeline is a set inherent index, namely the NOx concentration is lower than the value to meet the emission requirement, namely the target value of the NOx concentration of the clean flue gas at the position.
The deviation can be calculated according to the existing emission index and the actual measured value, the first outlet concentration limit value comprises an upper limit value and a lower limit value, and when the time exceeding the upper limit value or being lower than the lower limit value reaches a first preset time, the controller is triggered to conduct control adjustment operation. The first preset time may be set according to actual operation, and is not described herein.
The emission requirement of the outlet of the SCR reactor, namely the target limit value of the NOx concentration at the outlet of the SCR reactor can be reversely pushed out according to the control analysis of the preset NFC master controller in the pipeline, and the target limit value can further influence the ammonia injection control in the reactor, so that the emitted NOx concentration meets the emission requirement, and the excessive ammonia injection cannot be caused to cause ammonia escape.
Further, step 101 includes:
calculating the concentration deviation of the net smoke NOx according to the net smoke NOx concentration measured value and the net smoke NOx concentration target value;
when the time that the concentration deviation of the clean smoke NOx exceeds the first outlet concentration limit value is longer than a first preset time, multiplying the concentration deviation of the clean smoke NOx by a first preset gain coefficient to obtain a static deviation correction value of the concentration of the clean smoke NOx;
calculating an initial limit value of the concentration of NOx at the outlet of the SCR reactor by adopting a preset NFC master controller according to the measured value of the concentration of the NOx in the clean flue gas and the target value of the concentration of the NOx in the clean flue gas;
and superposing the net smoke NOx concentration static deviation correction value on the SCR reactor outlet NOx concentration initial limit value to obtain the SCR reactor outlet NOx concentration target limit value.
The target value of the concentration of the clean flue gas NOx is a fixed index of the environmental emission, and the clean flue gas NOx can be discharged after reaching the standard. When the time that the deviation of the concentration of the clean flue gas NOx exceeds the first outlet concentration limit value is longer than the first preset time, the SCRA or SCRB denitration is required to be put into operation automatically, control intervention is required to be executed at the moment, namely, a corresponding static deviation correction value of the concentration of the clean flue gas NOx is calculated, the original limit value is generated by the NFC master controller without intervention, and the target limit value is obtained after the static deviation correction value is added.
Referring to FIG. 3, FIG. 3 is a diagram illustrating the generation of a static deviation correction value for net flue gas NOx concentration, where H/L represents a first outlet concentration limit, which represents an upper concentration limit and a lower concentration limit, respectively; the module has the function that when an input signal is greater than a concentration upper limit value or less than a concentration lower limit value, the output of the module is 1, otherwise, the output of the module is 0; the action mechanism of the TD ON module is that when an input signal lasts for a period of time 1, the output of the TD ON module is 1, otherwise, the output of the TD ON module is 0, and the specific duration time can be set according to needs. The static deviation correction value is not always acted on the controller, and after the static deviation correction value is continuously acted for a preset time, a pulse signal is sent out to stop the action of the static deviation correction value, the static deviation correction value is set to be zero from the aspect of numerical value change, and once the concentration deviation changes and meets the action condition, the static deviation correction value can repeatedly play a role in regulation and control.
And 102, when the time that the deviation of the NOx concentration at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time, calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor.
According to the same judgment principle as the determination process of the static deviation correction value of the NOx concentration of the clean flue gas, if the time that the NOx concentration deviation of the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than the second preset time and the SCRA denitration is automatically put into operation, intervention control is needed. The second outlet concentration limit value comprises an upper limit value and a lower limit value, and the time exceeding the upper limit value or being lower than the lower limit value reaches a second preset time, the controller is triggered to perform control adjustment operation. The second preset time may be set according to actual operation. It is understood that the outlet of the SCR reactor includes two sides, which can be referred to as the outlet of the SCRA reactor and the outlet of the SCRB reactor, and the specific control process is the same and will not be described herein.
And the intervention factor for intervening the NFC secondary controller is a NOx concentration static deviation correction value, and the target limit of the NOx concentration at the outlet of the SCR reactor is a target value at the outlet of the SCR reactor calculated according to the requirement of the exhaust port of the pipeline.
Further, step 102 includes:
calculating the NOx concentration deviation at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
and when the time that the concentration deviation of the NOx at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time, multiplying the concentration deviation of the NOx at the outlet of the SCR reactor by a second preset gain coefficient to obtain a static deviation correction value of the concentration of the NOx at the outlet of the SCR reactor.
The specific calculation process of the static deviation correction value of the NOx concentration at the outlet of the SCR reactor is the same as the calculation method of the static deviation correction value of the NOx concentration of the clean flue gas, and the preset gain coefficients can be set according to actual conditions.
Referring to FIG. 4, FIG. 4 is a graph illustrating the generation of a static deviation correction value for NOx concentration at the outlet of the SCR reactor, where H/L represents a second outlet concentration limit, which represents an upper concentration limit and a lower concentration limit, respectively; the module has the function that when an input signal is greater than a concentration upper limit value or less than a concentration lower limit value, the output of the module is 1, otherwise, the output of the module is 0; the action mechanism of the TD ON module is that when an input signal lasts for a period of time 1, the output of the TD ON module is 1, otherwise, the output of the TD ON module is 0, and the specific duration time can be set according to needs.
And 103, carrying out NOx concentration analysis according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor to obtain a corrected value of the NOx concentration change rate at the outlet of the SCR reactor.
The corrected value of the NOx concentration change rate at the outlet of the SCR reactor is a regularly changed value, the corrected value of the change rate is different according to different conditions, the interference flexibility of the control system can be enhanced through the regular change of the change rate, and the instability of the system due to external interference is avoided.
Further, step 103 includes:
calculating the NOx concentration change rate at the outlet of the SCR reactor according to the NOx concentration measured value at the outlet of the SCR reactor and the NOx concentration target limit value at the outlet of the SCR reactor;
if the concentration deviation of the NOx at the outlet of the SCR reactor exceeds a first concentration upper limit value and the change rate of the NOx at the outlet of the SCR reactor exceeds a second concentration upper limit value, controlling the change rate correction value of the NOx at the outlet of the SCR reactor to increase from zero to a first preset setting value at a first preset rate;
if the concentration deviation of the NOx at the outlet of the SCR reactor is lower than a first concentration lower limit value and the change rate of the NOx at the outlet of the SCR reactor is lower than a second concentration lower limit value, controlling the corrected value of the NOx concentration change rate at the outlet of the SCR reactor to increase from zero to a second preset set value at a second preset rate;
and if the deviation of the concentration of the NOx at the outlet of the SCR reactor is between a first concentration upper limit value and a first concentration lower limit value, and/or the change rate of the concentration of the NOx at the outlet of the SCR reactor is between a second concentration upper limit value and a second concentration lower limit value, controlling the corrected value of the NOx concentration change rate at the outlet of the SCR reactor to be zero.
The above shows that, only when the deviation of the NOx concentration at the outlet of the SCR reactor fluctuates between the first concentration upper limit and the first concentration lower limit, or the NOx concentration change rate at the outlet of the SCR reactor fluctuates between the second concentration upper limit and the second concentration lower limit, or both of them are satisfied, the NOx concentration change rate correction value at the outlet of the SCR reactor is stabilized to 0, or in the adjusting process, once the two indexes satisfy the condition, the NOx concentration change rate correction value at the outlet of the SCR reactor is rapidly set to zero, it can be understood that the NOx concentration change rate correction value at the outlet of the SCR reactor does not always act on the controller, but there is an intervening time period, and the NOx concentration change rate correction value at the outlet of the SCR reactor does not act after the time period, that is, the NOx concentration change rate correction value does not participate in the NFC control process. In other cases, the corrected value of the NOx concentration change rate at the outlet of the SCR reactor needs to be adjusted at a preset rate until the preset set value is reached.
Both the concentration upper limit value and the concentration lower limit value may be set according to actual conditions, and are not limited herein. Referring to FIG. 5, the change rate includes both the rising change condition and the falling change condition; the influence of LAG inertia elements, namely the rate of change, is also taken into account. For all H// modules, the expressed action principle is: when the input signal is greater than the concentration upper limit value, the output of the module is 1, otherwise, the output is 0; l// Module: when the lower limit value of the signal concentration is input, the output of the module is 1, otherwise, the output of the module is 0; the specific number is used for distinguishing different limit values; the RS flip-flop is also activated by a 0, 1 trigger.
And 104, acquiring an ammonia injection valve adjusting control instruction by adopting a preset NFC secondary controller according to the measured value of the concentration of the NOx at the outlet of the SCR reactor, the target limit value of the concentration of the NOx at the outlet of the SCR reactor, the static deviation correction value of the concentration of the NOx at the outlet of the SCR reactor and the correction value of the concentration change rate of the NOx at the outlet of the SCR reactor.
The static deviation correction value of the NOx concentration at the outlet of the SCR reactor and the change rate correction value of the NOx concentration at the outlet of the SCR reactor are intervention factors on a preset NFC secondary controller, and are superposed on the controller to obtain an intervention control result, namely an ammonia injection regulating valve control instruction, so that the method is more targeted, and the self-adaptive control of the ammonia injection regulating valve can be completed without manual adjustment.
Further, step 104 includes:
performing NFC control by adopting a preset NFC secondary controller according to the measured value of the concentration of NOx at the outlet of the SCR reactor and the target limit value of the concentration of NOx at the outlet of the SCR reactor to obtain an initial control instruction of an ammonia injection valve;
and superposing the corrected value of the static deviation of the NOx concentration at the outlet of the SCR reactor and the corrected value of the NOx concentration change rate at the outlet of the SCR reactor into an initial control instruction of the ammonia injection valve to obtain the control instruction of the ammonia injection valve.
It has been explained above that the SCR reactor outlet NOx concentration change rate correction value is not substantially always applied to the controller, but is not applied when its value is 0. Similarly, the same is true for correcting the static deviation of the NOx concentration at the outlet of the SCR reactor, and not always, but after a period of time, a new pulse will terminate its action and return to the normal control flow. And is started again when the intervention control condition is met.
And 105, controlling the opening degree of the ammonia spraying valve through the ammonia spraying valve control command so as to control the change of the ammonia spraying amount.
Further, step 105, before, further comprising:
when the sensor is in the purging mode, the preset switcher suspends the instruction receiving of the preset NFC secondary controller, and the instruction receiving of the preset NFC secondary controller is resumed after the purging mode is finished.
In order to avoid the uncertain influence of the ammonia injection control system caused by the uncertain change of the net flue gas NOx concentration when the net flue gas NOx concentration transmitter sweeps, a switcher is added, and the output of the switcher is used for obtaining the ammonia injection throttle control instruction in the switching stage. And when the sensor is detected to be in a purging mode, maintaining the ammonia spraying control instruction in the switching stage through the switcher, and receiving the output of the controller until the purging of the sensor is finished, so that the ammonia spraying control instruction in the switching stage is equal to the obtained ammonia spraying control instruction, and finally obtaining the ammonia spraying control instruction for controlling the ammonia spraying control.
Besides the switch can be adopted for the ammonia spraying gate regulating control instruction, the switch can be added behind the NFC main controller, and the switch is used for avoiding the influence of purging of the transmitter on the NOx concentration target limit value at the outlet of the SCR reactor; the specific control mechanism is the same as the above-mentioned command control mechanism, and is not described herein again.
For convenience of understanding, the present embodiment provides a very simple flow system for ammonia injection control, wherein mainly an NFC master controller and two NFC slave controllers refer to fig. 6, concentration setting is a threshold value or a target limit value, and ammonia injection throttle control instructions on the a side and the B side can be obtained to control the opening of the ammonia injection throttle, so as to complete selective catalytic reduction reaction, so that the NOx concentration in the final exhaust gas meets the requirement of atmospheric emission. Referring to fig. 7, the system incorporating the switch is disposed at the position of the sensor, and the detailed control process is not repeated.
Therefore, the control strategy adopted by the embodiment of the application only relates to the clean flue gas NOx concentration, the SCR outlet NOx concentration and purging and maintaining signals of corresponding NOx concentration sensors, so that the related signals of the denitration system are reduced to the maximum extent, and the system is simplified to a great extent; the problems that the existing ammonia injection control system has many measuring devices, large maintenance workload, too many indexes, inaccurate measurement and unstable control are solved.
According to the extremely simple ammonia injection control method provided by the embodiment, NFC is selected in the controller, the control performance of NOx emission concentration is improved to a great extent, and the NFC has good adjustability and is convenient to use and master; in addition, when the concentration deviation of NOx at the outlet of the SCR reactor exceeds the concentration limit value and reaches a certain time, a static NOx concentration deviation correction value and a NOx concentration change rate correction value can be added into a signal obtained by the NFC controller, an ammonia injection valve control command generated through flexible NFC control can adaptively control the opening size of the ammonia injection valve, external disturbance of the system is effectively overcome, the stability of the system can be guaranteed through an accurate control mode, manual intervention is not needed, and ammonia escape cannot be caused through the influence of feed-forward quantity. Therefore, the technical problems that the existing SCR control system is poor in ammonia spraying self-adaptive control effect due to the fact that a fixed ammonia-nitrogen ratio is adopted, excessive ammonia spraying is easily caused, manual intervention is needed in system work, and ammonia escape is easily caused can be solved.
For ease of understanding, referring to fig. 2, the present application also provides a simplified embodiment of an ammonia injection control device, comprising:
the target limit control module 201 is configured to, when the time that the deviation of the net flue gas NOx concentration exceeds the first outlet concentration limit is longer than a first preset time, perform NOx concentration control by using a preset NFC master controller according to the net flue gas NOx concentration measurement value to obtain an outlet NOx concentration target limit of the SCR reactor;
the static deviation calculation module 202 is used for calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor when the time that the NOx concentration deviation at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time;
the concentration change rate calculation module 203 is used for analyzing the NOx concentration according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor to obtain a corrected value of the NOx concentration change rate at the outlet of the SCR reactor;
the ammonia injection instruction generating module 204 is used for acquiring an ammonia injection valve control instruction by adopting a preset NFC secondary controller according to the measured value of the concentration of NOx at the outlet of the SCR reactor, the target limit value of the concentration of NOx at the outlet of the SCR reactor, the static deviation correction value of the concentration of NOx at the outlet of the SCR reactor and the correction value of the concentration change rate of NOx at the outlet of the SCR reactor;
and the ammonia spraying control module 205 is used for controlling the opening degree of the ammonia spraying control valve through the ammonia spraying control instruction so as to control the change of the ammonia spraying amount.
Further, the target limit control module 201 includes:
a first concentration deviation calculation submodule 2011, configured to calculate a net flue gas NOx concentration deviation according to the net flue gas NOx concentration measurement value and the net flue gas NOx concentration target value;
the first deviation correction calculation sub-module 2022 is configured to, when the time that the net flue gas NOx concentration deviation exceeds the first outlet concentration limit value is longer than a first preset time, multiply the net flue gas NOx concentration deviation by a first preset gain coefficient to obtain a net flue gas NOx concentration static deviation correction value;
the concentration initial limit value calculating submodule 2023 is used for calculating an initial limit value of the concentration of the NOx at the outlet of the SCR reactor according to the measured value of the concentration of the NOx in the clean flue gas and the target value of the concentration of the NOx in the clean flue gas by adopting a preset NFC master controller;
and the superposition correction processing submodule 2024 is used for superposing the static deviation correction value of the net flue gas NOx concentration on the initial limit value of the SCR reactor outlet NOx concentration to obtain the target limit value of the SCR reactor outlet NOx concentration.
Further, the static deviation calculating module 202 is specifically configured to:
a second concentration deviation calculation submodule 2021, configured to calculate an SCR reactor outlet NOx concentration deviation according to the SCR reactor outlet NOx concentration measurement value and the SCR reactor outlet NOx concentration target limit;
and the second deviation correction calculation submodule 2022 is configured to, when the time that the NOx concentration deviation at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time, multiply the NOx concentration deviation at the outlet of the SCR reactor by a second preset gain coefficient to obtain a static deviation correction value of the NOx concentration at the outlet of the SCR reactor.
Further, the concentration change rate calculation module 203 includes:
the change rate calculation submodule 2031 is used for calculating the change rate of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
the first judgment sub-module 2032 is configured to, if the deviation of the NOx concentration at the outlet of the SCR reactor exceeds the first concentration upper limit value and the NOx concentration change rate at the outlet of the SCR reactor exceeds the second concentration upper limit value, control the NOx concentration change rate correction value at the outlet of the SCR reactor to increase from zero to a first preset setting value at a first preset rate;
a second determination submodule 2033, configured to, if the deviation of the NOx concentration at the outlet of the SCR reactor is lower than the first concentration lower limit value, and the NOx concentration change rate at the outlet of the SCR reactor is lower than the second concentration lower limit value, control the NOx concentration change rate correction value at the outlet of the SCR reactor to increase from zero to a second preset setting value at a second preset rate;
a third determining sub-module 2034 configured to control the SCR reactor outlet NOx concentration change rate correction value to zero if the SCR reactor outlet NOx concentration deviation is between the first concentration upper limit value and the first concentration lower limit value, and/or if the SCR reactor outlet NOx concentration change rate is between the second concentration upper limit value and the second concentration lower limit value.
In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for executing all or part of the steps of the method described in the embodiments of the present application through a computer device (which may be a personal computer, a server, or a network device). And the aforementioned storage medium includes: a U disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims (10)

1. A very simple ammonia injection control method is characterized by comprising the following steps:
when the time that the deviation of the concentration of the NOx in the clean flue gas exceeds the first outlet concentration limit value is longer than first preset time, a preset NFC main controller is adopted to control the concentration of the NOx according to the measured value of the concentration of the NOx in the clean flue gas, and the target limit value of the concentration of the NOx at the outlet of the SCR reactor is obtained;
when the time that the deviation of the NOx concentration at the outlet of the SCR reactor exceeds a second outlet concentration limit value is longer than a second preset time, calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
carrying out NOx concentration analysis according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor to obtain a corrected value of the NOx concentration change rate at the outlet of the SCR reactor;
acquiring an ammonia injection valve control instruction by adopting a preset NFC secondary controller according to the measured value of the concentration of the NOx at the outlet of the SCR reactor, the target limit value of the concentration of the NOx at the outlet of the SCR reactor, the static deviation correction value of the concentration of the NOx at the outlet of the SCR reactor and the correction value of the concentration change rate of the NOx at the outlet of the SCR reactor;
and controlling the opening degree of the ammonia spraying control valve through the ammonia spraying control instruction so as to control the change of the ammonia spraying amount.
2. The very simplified ammonia injection control method of claim 1, wherein when the time that the deviation of the net flue gas NOx concentration exceeds the first outlet concentration limit is longer than a first preset time, the obtaining the target SCR reactor outlet NOx concentration limit by performing NOx concentration control with a preset NFC master controller according to the measured net flue gas NOx concentration value comprises:
calculating the concentration deviation of the net smoke NOx according to the net smoke NOx concentration measured value and the net smoke NOx concentration target value;
when the time that the concentration deviation of the clean flue gas NOx exceeds the first outlet concentration limit value is longer than a first preset time, multiplying the concentration deviation of the clean flue gas NOx by a first preset gain coefficient to obtain a static deviation correction value of the concentration of the clean flue gas NOx;
calculating an initial limit value of the concentration of NOx at the outlet of the SCR reactor by adopting a preset NFC master controller according to the measured value of the concentration of NOx in the clean flue gas and the target value of the concentration of NOx in the clean flue gas;
and superposing the net smoke NOx concentration static deviation correction value on the SCR reactor outlet NOx concentration initial limit value to obtain the SCR reactor outlet NOx concentration target limit value.
3. The very simplified ammonia injection control method of claim 1, where calculating an SCR reactor outlet NOx concentration static deviation correction value based on an SCR reactor outlet NOx concentration measurement and the SCR reactor outlet NOx concentration target limit when the time at which the SCR reactor outlet NOx concentration deviation exceeds a second outlet concentration limit is greater than a second preset time, comprises:
calculating the NOx concentration deviation at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
and when the time that the concentration deviation of the NOx at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time, multiplying the concentration deviation of the NOx at the outlet of the SCR reactor by a second preset gain coefficient to obtain a static deviation correction value of the concentration of the NOx at the outlet of the SCR reactor.
4. The very simplified ammonia injection control method of claim 3, where the analyzing NOx concentrations based on the SCR reactor outlet NOx concentration measurement and the SCR reactor outlet NOx concentration target limit to obtain an SCR reactor outlet NOx concentration change rate correction value comprises:
calculating the NOx concentration change rate at the outlet of the SCR reactor according to the NOx concentration measured value at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
if the concentration deviation of the NOx at the outlet of the SCR reactor exceeds a first concentration upper limit value and the change rate of the NOx at the outlet of the SCR reactor exceeds a second concentration upper limit value, controlling the change rate correction value of the NOx at the outlet of the SCR reactor to increase from zero to a first preset setting value at a first preset rate;
if the deviation of the concentration of the NOx at the outlet of the SCR reactor is lower than a first concentration lower limit value, and the change rate of the concentration of the NOx at the outlet of the SCR reactor is lower than a second concentration lower limit value, controlling the change rate correction value of the concentration of the NOx at the outlet of the SCR reactor to increase from zero to a second preset setting value at a second preset rate;
and if the deviation of the concentration of the NOx at the outlet of the SCR reactor is between the first concentration upper limit value and the first concentration lower limit value, and/or the change rate of the concentration of the NOx at the outlet of the SCR reactor is between the second concentration upper limit value and the second concentration lower limit value, controlling the corrected value of the NOx concentration change rate at the outlet of the SCR reactor to be zero.
5. The simplified ammonia injection control method according to claim 1, wherein the obtaining an ammonia injection gating control command by using a pre-set NFC secondary controller according to the SCR reactor outlet NOx concentration measurement value, the SCR reactor outlet NOx concentration target limit value, the SCR reactor outlet NOx concentration static deviation correction value, and the SCR reactor outlet NOx concentration change rate correction value comprises:
performing NFC control by adopting a preset NFC secondary controller according to the measured value of the concentration of the NOx at the outlet of the SCR reactor and the target limit value of the concentration of the NOx at the outlet of the SCR reactor to obtain an initial control instruction of an ammonia spraying throttle;
and superposing the static deviation correction value of the NOx concentration at the outlet of the SCR reactor and the change rate correction value of the NOx concentration at the outlet of the SCR reactor to the initial control instruction of the ammonia injection regulating valve to obtain the control instruction of the ammonia injection regulating valve.
6. The simplified ammonia injection control method according to claim 1, wherein the ammonia injection control command controls the opening of the ammonia injection valve to control the change of the ammonia injection amount, and the method further comprises:
when the sensor is in the purging mode, command receiving to the preset NFC secondary controller is suspended through a preset switcher, and command receiving to the preset NFC secondary controller is resumed after the purging mode is finished.
7. An extremely simple ammonia injection control device, comprising:
the target limit control module is used for controlling the concentration of the NOx by adopting a preset NFC main controller according to the measured value of the concentration of the NOx in the clean flue gas when the time that the concentration deviation of the NOx in the clean flue gas exceeds the first outlet concentration limit value is longer than a first preset time, so that the target limit of the concentration of the NOx in the outlet of the SCR reactor is obtained;
the static deviation calculation module is used for calculating a static deviation correction value of the NOx concentration at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor when the time that the NOx concentration deviation at the outlet of the SCR reactor exceeds the second outlet concentration limit value is longer than a second preset time;
the concentration change rate calculation module is used for carrying out NOx concentration analysis according to the SCR reactor outlet NOx concentration measured value and the SCR reactor outlet NOx concentration target limit value to obtain an SCR reactor outlet NOx concentration change rate correction value;
the ammonia injection instruction generating module is used for acquiring an ammonia injection valve control instruction according to the measured value of the NOx concentration at the outlet of the SCR reactor, the target limit value of the NOx concentration at the outlet of the SCR reactor, the static deviation correction value of the NOx concentration at the outlet of the SCR reactor and the correction value of the NOx concentration change rate at the outlet of the SCR reactor by adopting a preset NFC secondary controller;
and the ammonia spraying control module is used for controlling the opening degree of the ammonia spraying control valve through the ammonia spraying control instruction so as to control the change of the ammonia spraying amount.
8. The minimalist ammonia injection control apparatus of claim 7 wherein the target limit control module includes:
the first concentration deviation calculation submodule is used for calculating the net flue gas NOx concentration deviation according to the net flue gas NOx concentration measured value and the net flue gas NOx concentration target value;
the first deviation correction calculation submodule is used for multiplying the net flue gas NOx concentration deviation by a first preset gain coefficient when the time that the net flue gas NOx concentration deviation exceeds a first outlet concentration limit value is longer than a first preset time to obtain a net flue gas NOx concentration static deviation correction value;
the concentration initial limit value calculation submodule is used for calculating an SCR reactor outlet NOx concentration initial limit value according to the net flue gas NOx concentration measured value and the net flue gas NOx concentration target value by adopting a preset NFC main controller;
and the superposition correction processing submodule is used for superposing the net flue gas NOx concentration static deviation correction value on the SCR reactor outlet NOx concentration initial limit value to obtain the SCR reactor outlet NOx concentration target limit value.
9. The ultra-simple ammonia injection control apparatus of claim 7, wherein the static deviation calculation module is specifically configured to:
the second concentration deviation calculation submodule is used for calculating the NOx concentration deviation at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
and the second deviation correction calculation submodule is used for multiplying the NOx concentration deviation at the outlet of the SCR reactor by a second preset gain coefficient when the time that the NOx concentration deviation at the outlet of the SCR reactor exceeds a second outlet concentration limit value is longer than a second preset time to obtain a static deviation correction value of the NOx concentration at the outlet of the SCR reactor.
10. The ultra-simple ammonia injection control apparatus of claim 9, wherein the concentration change rate calculation module comprises:
the change rate calculation submodule is used for calculating the NOx concentration change rate at the outlet of the SCR reactor according to the measured value of the NOx concentration at the outlet of the SCR reactor and the target limit value of the NOx concentration at the outlet of the SCR reactor;
the first judgment sub-module is used for controlling the NOx concentration change rate correction value at the outlet of the SCR reactor to increase from zero to a first preset setting value at a first preset rate if the concentration deviation of the NOx at the outlet of the SCR reactor exceeds a first concentration upper limit value and the NOx concentration change rate at the outlet of the SCR reactor exceeds a second concentration upper limit value;
the second judgment sub-module is used for controlling the NOx concentration change rate correction value at the outlet of the SCR reactor to increase from zero to a second preset setting value at a second preset rate if the deviation of the NOx concentration at the outlet of the SCR reactor is lower than a first concentration lower limit value and the NOx concentration change rate at the outlet of the SCR reactor is lower than a second concentration lower limit value;
and the third judgment sub-module is used for controlling the corrected value of the NOx concentration change rate at the outlet of the SCR reactor to be zero if the deviation of the NOx concentration at the outlet of the SCR reactor is between the first concentration upper limit value and the first concentration lower limit value and/or the NOx concentration change rate at the outlet of the SCR reactor is between the second concentration upper limit value and the second concentration lower limit value.
CN202110707762.5A 2021-06-24 2021-06-24 Simple ammonia injection control method and device Active CN113398757B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110707762.5A CN113398757B (en) 2021-06-24 2021-06-24 Simple ammonia injection control method and device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110707762.5A CN113398757B (en) 2021-06-24 2021-06-24 Simple ammonia injection control method and device

Publications (2)

Publication Number Publication Date
CN113398757A true CN113398757A (en) 2021-09-17
CN113398757B CN113398757B (en) 2022-05-17

Family

ID=77683173

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110707762.5A Active CN113398757B (en) 2021-06-24 2021-06-24 Simple ammonia injection control method and device

Country Status (1)

Country Link
CN (1) CN113398757B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010234321A (en) * 2009-03-31 2010-10-21 Chugoku Electric Power Co Inc:The Ammonia injection amount correction controller and ammonia injection amount correction control method
CN205216582U (en) * 2015-11-09 2016-05-11 湖南中冶长天节能环保技术有限公司 Iron and steel sintering flue gas is synthesized desulfurization, denitration and is got rid of device of dioxin
CN105797576A (en) * 2016-04-15 2016-07-27 中国大唐集团科学技术研究院有限公司西北分公司 Coal-fired unit denitration ammonia spraying control method
CN107694300A (en) * 2016-08-08 2018-02-16 中冶长天国际工程有限责任公司 The ammonia spraying amount control method and device of active carbon desulfurization denitrating system
CN108187492A (en) * 2018-01-17 2018-06-22 广东电网有限责任公司电力科学研究院 A kind of spray ammonia control method and device
CN109078496A (en) * 2018-09-03 2018-12-25 中国大唐集团科学技术研究院有限公司华中分公司 A kind of denitration control method and device based on the escaping of ammonia
CN110252132A (en) * 2019-06-14 2019-09-20 许昌龙岗发电有限责任公司 The exploitation of SCR denitration Optimal Control System and application method based on multi-parameter prediction

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010234321A (en) * 2009-03-31 2010-10-21 Chugoku Electric Power Co Inc:The Ammonia injection amount correction controller and ammonia injection amount correction control method
CN205216582U (en) * 2015-11-09 2016-05-11 湖南中冶长天节能环保技术有限公司 Iron and steel sintering flue gas is synthesized desulfurization, denitration and is got rid of device of dioxin
CN105797576A (en) * 2016-04-15 2016-07-27 中国大唐集团科学技术研究院有限公司西北分公司 Coal-fired unit denitration ammonia spraying control method
CN107694300A (en) * 2016-08-08 2018-02-16 中冶长天国际工程有限责任公司 The ammonia spraying amount control method and device of active carbon desulfurization denitrating system
CN108187492A (en) * 2018-01-17 2018-06-22 广东电网有限责任公司电力科学研究院 A kind of spray ammonia control method and device
CN109078496A (en) * 2018-09-03 2018-12-25 中国大唐集团科学技术研究院有限公司华中分公司 A kind of denitration control method and device based on the escaping of ammonia
CN110252132A (en) * 2019-06-14 2019-09-20 许昌龙岗发电有限责任公司 The exploitation of SCR denitration Optimal Control System and application method based on multi-parameter prediction

Also Published As

Publication number Publication date
CN113398757B (en) 2022-05-17

Similar Documents

Publication Publication Date Title
CN107243257B (en) It is suitble to the intelligence spray ammonia control system of full load
CN105797576B (en) Denitration ammonia injection control method for coal-fired unit
CN105700570B (en) SCR denitration control method for thermal power plant
CN104785105B (en) Small-sized SCR denitrating flue gas spray ammonia control system and method
CN108837699A (en) It is a kind of that ammonia optimization method and system are intelligently sprayed based on the SCR denitration of hard measurement and PREDICTIVE CONTROL
CN111841276B (en) SNCR denitration control method and device for circulating fluidized bed unit and storage medium
CN110501901B (en) SCR ammonia injection regulation optimization method based on full-load accurate denitration requirement
CN104678761B (en) Total air volume advanced control-based denitration control method and system for thermal power unit
CN105892504A (en) Thermal power plant denitration ammonia supplying automatic return circuit control method and system
CN111897373A (en) Model prediction-based ammonia injection flow adjusting method for SCR denitration device
CN108187492B (en) Ammonia spraying control method and device
CN103455055A (en) Method for adjusting pH value through multipoint detection fuzzy PID control in raw water treatment
CN113398757B (en) Simple ammonia injection control method and device
CN111135683B (en) SNCR denitration automatic control method and system
CN112667613A (en) Flue gas NOx prediction method and system based on multi-delay characteristic multivariable correction
CN109078496B (en) Denitration control method and device based on ammonia escape
CN109046021B (en) SCR system accurate ammonia injection control method with strong self-adaptive capacity
CN115591378B (en) Feedforward compensation and disturbance suppression control system and method for SCR denitration of thermal power generating unit
CN109433003B (en) Method and device for controlling ammonia injection amount of denitration control system
JP4792696B2 (en) Denitration control method, denitration control device and program thereof
CN105511436B (en) The control method for coordinating of two reactor ammonia spraying amounts of flue gas denitrification system and system
CN113274878B (en) Thermal power plant denitration outlet nitrogen oxide standard exceeding phenomenon control method
CN113433980B (en) Calculating denitration inlet NO under blowing working condition by system error method x Method for measuring values
CN108371888A (en) Prevent the SCR denitration system control method of urea overspray
CN109794149B (en) Automatic control method and system for flue gas denitration of CFB boiler

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant