CN107449876B - Reducing agent distribution adjusting system - Google Patents
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- 239000003638 chemical reducing agent Substances 0.000 title claims abstract description 133
- 238000005070 sampling Methods 0.000 claims abstract description 194
- 238000005259 measurement Methods 0.000 claims abstract description 52
- 238000000034 method Methods 0.000 claims abstract description 11
- 239000000523 sample Substances 0.000 claims description 16
- 238000001914 filtration Methods 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- 239000003054 catalyst Substances 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- 238000005086 pumping Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims description 2
- 230000001105 regulatory effect Effects 0.000 abstract description 34
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 abstract description 20
- 229910021529 ammonia Inorganic materials 0.000 abstract description 10
- 230000008901 benefit Effects 0.000 abstract description 4
- 230000007613 environmental effect Effects 0.000 abstract description 4
- 239000007789 gas Substances 0.000 description 40
- 230000008859 change Effects 0.000 description 9
- 239000003344 environmental pollutant Substances 0.000 description 6
- 231100000719 pollutant Toxicity 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 239000003546 flue gas Substances 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
- G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
- G01N33/0037—NOx
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- 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
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D7/00—Control of flow
- G05D7/06—Control of flow characterised by the use of electric means
- G05D7/0617—Control of flow characterised by the use of electric means specially adapted for fluid materials
- G05D7/0629—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
- G05D7/0635—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means
- G05D7/0641—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means using a plurality of throttling means
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Abstract
The present application provides a reductant dispensing adjustment system, comprising: the method comprises the steps of performing distributed sampling on the section of an SCR inlet flue, measuring NOx concentration data of sampling gas at distributed sampling points, and obtaining a distributed measurement system of SCR inlet NOx concentration field data; a control system for determining a reductant dispensing adjustment strategy based on the SCR inlet NOx concentration field data measured by the distributed measurement system; and a reducing agent distribution adjustment unit that performs distribution adjustment of the reducing agent based on the distribution adjustment strategy, and feeds back a distribution adjustment result to the control system, so that the control system adjusts the distribution adjustment strategy of the reducing agent based on the distribution adjustment result. The reducing agent distribution regulating system improves SCR denitration efficiency, reduces ammonia escape level, reduces consumption of SCR reducing agent, and has good economic benefit and environmental benefit.
Description
Technical Field
The invention relates to the technical field of flue gas treatment of thermal power plants, in particular to a reducing agent distribution and adjustment system.
Background
Currently, the environmental management task of China is difficult, the ultralow emission of China is expanding and accelerating, and the requirements on energy conservation and emission reduction are increasingly strict. According to the related requirements of national emission and change commission, energy bureau, environmental protection issuing ' energy saving and emission reduction upgrading and reformation action plan of coal and electricity (2014-2020) and ' comprehensive implementation of ultralow emission and energy saving reformation working scheme of coal-fired power plant ', the NOx emission concentration of the flue gas of the coal-fired power plant should be controlled below 50mg/Nm3, the NOx emission levels of different coal types and different boiler types are different (generally 300-500mg/Nm3, a W flame furnace can even reach 1000mg/Nm 3), and the NOx concentration field of an SCR inlet has great change along with time and load. To achieve high denitration efficiency of over 90%, very strict requirements are put forward on ammonia nitrogen mixing deviation of SCR inlet flue gas.
The denitration efficiency of the early SCR system is generally designed in the range of 60% -80%, the efficiency requirement is not high, the SCR reducer distribution system generally adopts a conventional ammonia injection grid or vortex mixing plate, after leveling is carried out according to the concentration distribution condition of NOx at the inlet of the full-load SCR during unit debugging, the denitration efficiency is generally maintained unchanged during operation, and the reducer supply is only used for adjusting the ammonia injection adjusting valve according to the concentration at the inlet and the outlet of the SCR.
In fact, the speed field and the NOx concentration field also change obviously with the change of time, load and combustion state, the denitration efficiency is lower due to the higher allowable emission concentration of NOx, the change of the inlet NOx concentration field and the speed field caused by the load fluctuation of the unit or the change of the combustion working condition generally does not have great influence on the overall denitration efficiency, but the ammonia slip has caused great pressure on the operation of the air conditioner under the current condition. Under the ultralow emission working condition, the allowable emission concentration of NOx is greatly reduced, the existing reducing agent distribution system is difficult to achieve the required high denitration efficiency, and meanwhile, the ammonia escape is seriously out of standard, so that the normal operation of a unit is influenced.
Disclosure of Invention
In view of the above, the invention provides a reducing agent distribution adjusting system for solving the problems that the existing reducing agent distribution system is difficult to achieve the required high denitration efficiency and the ammonia escape is seriously out of standard, which comprises the following technical scheme:
a reductant dispensing adjustment system, comprising:
the method comprises the steps of performing distributed sampling on the section of an SCR inlet flue, measuring NOx concentration data of sampling gas at distributed sampling points, and obtaining a distributed measurement system of SCR inlet NOx concentration field data;
a control system connected with the distributed measurement system for determining a distribution regulation strategy of the reducing agent based on the SCR inlet NOx concentration field data measured by the distributed measurement system, wherein the distribution regulation strategy comprises distribution regulation parameters of the reducing agent;
and a reducing agent distribution adjusting unit which is connected with the control system, is matched with the distributed measuring system, performs distribution adjustment on the reducing agent based on the distribution adjusting strategy, and feeds back a distribution adjusting result to the control system so that the control system adjusts the distribution adjusting strategy of the reducing agent based on the distribution adjusting result.
The distributed measurement system is used for performing time-sharing distributed sampling on the section of the SCR inlet flue and measuring NOx concentration data of time-sharing distributed sampling points.
Wherein the distributed measurement system comprises:
the sampling system is used for carrying out distributed sampling on the section of the SCR inlet flue to obtain sampling gas of a plurality of distributed sampling points;
the time-sharing distributed switching device is connected with the sampling system and used for switching the distributed sampling points through a set switch so as to realize time-sharing measurement of different sampling points;
the sampling power unit is connected with the time-sharing distributed switching device and used for providing power for the sampling gas of the distributed sampling points;
and the measuring device is connected with the sampling power unit and used for measuring the sampling gas sent by the sampling power unit to obtain the data of the NOx concentration field at the SCR inlet.
Wherein the measuring device comprises:
sampling probe for pumping the sampling gas by sampling pump and filtering and heating the pumped gas;
the heat tracing pipeline is connected with the sampling probe, and is used for conveying the gas sampled, filtered and heated by the sampling probe and carrying out high-temperature heat tracing on the conveyed gas;
the pretreatment device is connected with the heat tracing pipeline and used for cooling, drying and filtering the gas transmitted by the heat tracing pipeline to obtain the gas to be analyzed;
the NOx analyzer is connected with the pretreatment device and used for analyzing the concentration of NOx of the gas to be analyzed;
and the device is respectively connected with the sampling probe, the heat tracing pipeline, the pretreatment device and the NOx analyzer, and is used for controlling the sampling probe, the heat tracing pipeline, the pretreatment device and the NOx analyzer to extract, transmit, process and analyze the sampling gas.
Wherein, the sampling power unit includes: the sampling power unit is used for sending the sampling gas of the distributed sampling points to the measuring device through the sampling pipeline.
The sampling system comprises a plurality of sampling units, wherein the sampling system performs distributed sampling on the section of the SCR inlet flue through the sampling units to obtain sampling gas of the distributed sampling points;
the allocation adjustment unit comprises:
a reducing agent distribution unit that distributes the reducing agent based on the distribution adjustment strategy, the same number of sampling points as the distributed sampling;
and reducing agent adjusting units, which are the same as the number of the reducing agent dispensing units, for adjusting the supply amount of the reducing agent based on the dispensing adjustment strategy.
Wherein the reducing agent adjusting unit is an adjusting valve;
the dispense adjustment parameters in the dispense adjustment strategy include an opening of the adjustment valve.
The sampling mode of the sampling system is grid sampling.
The technical scheme has the following beneficial effects:
in the reducing agent distribution regulating system provided by the invention, the distributed measuring system can measure the NOx concentration of the sampling gas at the distributed sampling points of the cross section of the SCR inlet flue so as to obtain concentration distribution data of the NOx at the SCR inlet, the control system can determine a distribution regulating strategy of the reducing agent based on the concentration distribution data of the NOx at the SCR inlet, the reducing agent distribution regulating unit can carry out distribution regulation on the reducing agent based on the distribution regulating strategy of the reducing agent, and the control system can also adjust the distribution regulating strategy based on the distribution regulating result so that the reducing agent distribution regulating unit can further regulate the reducing agent based on the adjusted distribution regulating strategy until the regulating effect is optimal. Therefore, the reducing agent distribution regulating system provided by the invention can intelligently distribute the reducing agent according to the NOx concentration field data of the SCR inlet, accurately regulate the supply quantity of the reducing agent in real time, avoid overlarge ammonia nitrogen mixing deviation caused by uneven distribution of the NOx concentration field of the SCR inlet and incapability of tracking regulation of the supply quantity of the reducing agent due to working condition change, and finally cause phenomena of reduced denitration efficiency, excessive ammonia escape and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a reductant dispensing adjustment system according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of a reducing agent distribution control system according to an embodiment of the present invention;
fig. 3 is a schematic structural view of a measuring device in a reducing agent distribution adjusting system according to an embodiment of the present invention.
Description of the embodiments
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
An embodiment of the present invention provides a reducing agent distribution adjusting system, referring to fig. 1, which shows a schematic structural diagram of the reducing agent distribution adjusting system, and may include: a distributed measurement system 101, a control system 102 and a reductant dispensing adjustment unit 103. Wherein the distributed measurement system 101 is connected to the control system 102, the reducing agent distribution regulating unit 103 is also connected to the control system 102, and the reducing agent distribution regulating unit 103 is matched to the distributed measurement system 101.
The distributed measurement system 101 is configured to perform distributed sampling on a section of the SCR inlet flue, and measure NOx concentration data of sampled gas at distributed sampling points to obtain SCR inlet NOx concentration field data.
A control system 102 for determining a reductant dispensing adjustment strategy based on the SCR inlet NOx concentration field data measured by the distributed measurement system 101, wherein the dispensing adjustment strategy includes a reductant dispensing adjustment parameter.
The reductant dispensing adjustment unit 103 is configured to perform dispensing adjustment on the reductant based on a dispensing adjustment strategy determined by the control system 102, and feedback a dispensing adjustment result to the control system 102.
The control system 102 is further configured to adjust a distribution adjustment strategy of the reducing agent based on a distribution adjustment result of the reducing agent distribution adjustment unit 103, so that the reducing agent distribution adjustment unit 103 adjusts the reducing agent supply amount based on the adjusted distribution adjustment strategy.
In the reducing agent distribution regulating system provided by the embodiment of the invention, the distributed measuring system can measure the NOx concentration of the sampling gas at the distributed sampling points of the cross section of the SCR inlet flue so as to obtain the concentration distribution data of the NOx of the SCR inlet pollutant, the distribution regulating strategy of the reducing agent can be determined by the control system based on the concentration distribution data of the NOx of the SCR inlet pollutant, and then the reducing agent is distributed and regulated by the reducing agent distribution regulating unit based on the distribution regulating strategy of the reducing agent. Therefore, the reducing agent distribution regulating system provided by the embodiment of the invention can intelligently distribute the reducing agent according to the NOx concentration field data of the SCR inlet, accurately regulate the supply quantity of the reducing agent in real time, avoid overlarge ammonia nitrogen mixing deviation caused by uneven distribution of the NOx concentration field of the SCR inlet and incapability of tracking regulation of the supply quantity of the reducing agent due to working condition change, and finally cause phenomena of reduced denitration efficiency, excessive ammonia escape and the like.
Referring to fig. 2, a schematic structural diagram of a reducing agent distribution adjusting system according to an embodiment of the present invention may include: a time-sharing distributed measurement system 201, a control system 202, and a reductant dispensing adjustment unit 203. Wherein the time-sharing distributed measurement system 201 is connected with the control system 202, and the reducing agent distribution adjusting unit 203 is also connected with the control system 202.
The time-sharing distributed measurement system 201 is configured to perform time-sharing distributed sampling on the cross section of the SCR inlet flue, and measure NOx concentration data at time-sharing distributed sampling points to obtain SCR inlet NOx concentration field data.
As can be seen from fig. 2, the time-shared distributed measurement system 201 may further comprise: a sampling system 2011, a time-sharing distributed switching device 2012, a sampling power unit 2013 and a measuring device 2014. The sampling system 2011 is connected to a time-sharing distributed switching device 2012, the time-sharing distributed switching device 2012 is connected to a sampling power unit 2013, and the sampling power unit 2013 is connected to a measuring device 2014.
The sampling system 2011 is configured to perform distributed sampling on a section of the SCR inlet flue to obtain sampled gas at a plurality of distributed sampling points.
In this embodiment, the sampling system 2011 is a distributed sampling system, and the sampling mode of the distributed sampling system may be grid sampling. As shown in fig. 2, the sampling system 2011 includes a plurality of sampling units, and the sampling system 2011 performs distributed sampling on the SCR inlet flue section through the plurality of sampling units, so as to obtain sampling gas at distributed sampling points.
The time-sharing distributed switching device 2012 is used for switching the distributed sampling points through the set switch so as to realize time-sharing measurement of different sampling points.
In this embodiment, the time-sharing distributed switching device 2012 includes a plurality of switches, each corresponding to a sampling point, and the exemplary distributed sampling points are 4, which are respectively sampling point 1, sampling point 2, sampling point 3 and sampling point 4, and assuming that the sampling time of each sampling point is 3 minutes and only 1 measuring device is used for measurement, the time-sharing sampling process of 4 sampling points is implemented by the switches: the switch corresponding to the sampling point 1 is opened, the switches corresponding to other sampling points are closed, sampling is carried out on the sampling point 1, after sampling is carried out on the sampling point 1 for 3 minutes, the switch corresponding to the sampling point 1 is closed, the switch corresponding to the sampling point 2 is opened, sampling is carried out on the sampling point 2 for 3 minutes, then the switch corresponding to the sampling point 2 is closed, the switch corresponding to the sampling point 3 is opened, sampling is carried out on the sampling point 3 for 3 minutes, then the switch corresponding to the sampling point 3 is closed, the switch corresponding to the sampling point 4 is opened, sampling is carried out on the sampling point 4 for 3 minutes, then the switch corresponding to the sampling point 4 is closed, and the total time consumption of the whole time-sharing sampling process is 12 minutes.
As can be seen from the above time-sharing sampling process, the embodiment of the present invention realizes the switching of the distributed sampling points by switching the switch, so as to realize the time-sharing sampling of the plurality of distributed sampling points, and further realize the measurement of the plurality of distributed measurement points (i.e., the measurement of the plurality of distributed measurement points is realized within an acceptable period), and the measurement strategy enables the measurement of the SCR inlet NOx concentration field data to be realized by using only one measurement device, so that the strategy of performing the time-sharing measurement on the distributed measurement points reduces the number of measurement devices in the system and reduces the measurement cost.
A sampling power unit 2013 for powering the sampled gas at distributed sampling points.
Specifically, the sampling power unit 2013 may include: the device comprises a sampling fan and a sampling pipeline. The sampling power unit sends sampling gas of distributed sampling points to the measuring device through a sampling pipeline by a sampling fan.
It should be noted that, the requirement of system time-sharing sampling should be satisfied by the sampling fan, and the fan flow of the sampling fan should ensure that the replacement of the sampling gas in the sampling pipeline is completed within the preset sampling time.
And the measuring device 2014 is used for measuring the sampled gas sent by the sampling power unit to obtain SCR inlet NOx concentration field data.
Still further, referring to fig. 3, a schematic structural diagram of a measurement device 2014 is shown, which may include: a sampling probe 301, a heat trace line 302, a pretreatment device 303, a NOx analyzer 304, and a controller 305. The sampling probe 301 is connected to a heat trace line 302, the heat trace line 302 is connected to a pretreatment device 303, the pretreatment device 303 is connected to a NOx analyzer 304, and the sampling probe 301, the heat trace line 302, the pretreatment device 303, and the NOx analyzer 304 are connected to a controller 305.
The sampling probe 301 is used for pumping sampling gas through the sampling pump and filtering and heating the pumped gas.
Wherein, the purpose of filtering the extracted gas is to remove dust in the gas, and the purpose of heating the filtered gas is to reduce the loss of NOx concentration of the gas in the transmission process.
And a heat tracing line 302 for transporting the gas sampled, filtered and heated by the sampling probe 301 and performing high-temperature heat tracing on the transported gas.
Among them, the purpose of high temperature heat tracing of the transport gas is also to reduce the loss of NOx concentration of the gas during transport.
The pretreatment device 303 is configured to cool, dry and filter the gas transmitted by the heat tracing pipeline 302, so as to obtain a gas to be analyzed.
Among them, the purpose of filtering the transported gas is to further remove impurities such as dust in the gas.
And the NOx analyzer 304 is configured to perform NOx concentration analysis on the gas to be analyzed obtained by the pretreatment device 303, and obtain SCR inlet NOx concentration field data.
A controller 305 for controlling the sampling probe 301, the heat tracing pipeline 302, the pretreatment device 303 and the NOx analyzer 304 to complete the extraction, transmission, processing and analysis of the sampled gas.
A control system 202 for determining a dispensing adjustment parameter of the reductant based on the SCR inlet NOx concentration field data measured by the time-sharing distributed measurement system 201, and transmitting a dispensing adjustment instruction including the dispensing adjustment parameter to the reductant dispensing adjustment unit 203.
The reducing agent distribution adjusting unit 203 is configured to perform distribution adjustment on the reducing agent based on a distribution adjustment instruction sent by the control system 202, and feed back a distribution adjustment result to the control system 202.
Further, the reducing agent distribution adjusting unit 203 may include: and a reducing agent distribution unit that distributes the reducing agent based on the distribution adjustment instruction, the same number of sampling points as the distributed sampling, and a reducing agent adjustment unit that adjusts the supply amount of the reducing agent based on the distribution adjustment instruction, the same number of reducing agent distribution units.
In one possible embodiment, the reducing agent regulating unit may be a regulating valve. The distribution adjusting parameters determined by the control system comprise the opening degree of the adjusting valve, and the reducing agent supply quantity is adjusted by adjusting the opening degree of the adjusting valve.
The control system 202 is further configured to adjust a distribution adjustment parameter of the reducing agent based on a distribution adjustment result of the reducing agent distribution adjustment unit 203, so that the reducing agent distribution adjustment unit 203 adjusts the reducing agent supply amount based on the adjusted distribution adjustment parameter.
It should be noted that, the control system 202 is a control center of the whole reducing agent distribution adjusting system, after obtaining the SCR inlet NOx concentration field data measured by the time-sharing distributed measurement system 201, the control system 202 calculates a distribution adjusting parameter of the reducing agent based on the data, specifically, the control system 202 calculates a total reducing agent distribution flow based on the SCR inlet NOx concentration field data, further outputs a total amount adjusting valve instruction, calculates an opening of each adjusting valve based on the SCR inlet NOx concentration field data, outputs a corresponding valve opening adjusting instruction, and the reducing agent distribution adjusting unit 203 performs an opening action after receiving the instruction, and feeds back an adjusting result to the control system, and the control system further optimizes the control logic through autonomous learning according to the adjusting result such as denitration efficiency, thereby realizing optimal control and further realizing fine adjustment of the SCR system.
The control process of the control system is described below by way of a specific example: if the coverage area of each catalyst module is 2 m x 2 m, the system should set up 12 catalyst modules in total of 3 x 4, and correspondingly, the time-sharing distributed measurement system should also set up 12 sampling points, if each measuring device realizes the time-sharing distributed measurement of 6 sampling points, 2 measuring devices can be set up to meet the requirement, if the sampling time of each sampling point is controlled to be 3min, the time required for realizing the measurement of the NOx concentration field at the inlet of the SCR is 18min. The control system may adopt a DCS system, the control function has an autonomous learning capability, the accuracy of control adjustment may be gradually improved by autonomous learning, specifically, in the debugging or initial operation stage of the control system, it is assumed that the NOx concentration of one of the 12 catalyst modules is 1.5 times of the average value (the module is referred to as a target module), the NOx concentrations of the other modules are all average values, the reducing agent distribution adjusting unit adjusts the opening of the adjusting valve corresponding to the module having the NOx concentration being the average value to 50% or to some other fixed opening, the opening of the adjusting valve corresponding to the target module is opened to the opening of the valve when the flow is 1.5 times of the flow according to the flow opening characteristic curve, this is a preliminary adjusting logic, when the control system finds that the denitration efficiency fed back by the reducing agent distribution adjusting unit is not optimal, for example, the opening of the adjusting valve is opened to be greater than the opening of the other valves by 1.5 times of the flow, the denitration efficiency is compared with the denitration efficiency before the adjustment, if the denitration efficiency is improved, the denitration efficiency is further improved, the opening of the valve is further opened to the valve is adjusted to be not optimal, and the opening of the adjusting valve is not adjusted to reach the optimal opening, if the opening is not adjusted, and the opening of the valves is not adjusted gradually is not adjusted.
It should be noted that, when designing the reducing agent distribution adjusting system provided by the embodiment of the present invention, firstly, reducing agent distribution adjusting units are designed based on specific specifications of the SCR inlet flue, the amount of reducing agent, and requirements of denitration efficiency, specifically, the number of reducing agent distribution units, distribution pipe distribution of each module, specification and number of reducing agent distribution openings of each distribution pipe, and specification and number of reducing agent adjusting units are determined based on the above factors; secondly, designing a time-sharing distributed measurement system according to the setting of a reducing agent distribution unit in a reducing agent distribution regulating unit, wherein the design number and the spatial distribution of sampling points of the time-sharing distributed measurement system are matched with the reducing agent distribution unit; then, designing a time-sharing distributed switching device and a sampling power unit, wherein the time-sharing distributed switching device realizes automatic switching of each sampling unit in a sampling system, the sampling power device can overcome the resistance of the sampling system, and meanwhile, the flow is selected to ensure constant-speed sampling, and meanwhile, the switching and sampling time of each sampling point is controlled within a preset sampling time period (such as 3 min); and finally, designing a control system according to the reducing agent distribution regulating unit and the time-sharing distributed measuring system, wherein the control system is connected with the time-sharing distributed measuring system and the reducing agent distribution regulating unit, and determining a distribution regulating strategy of the reducing agent distribution regulating unit based on the measuring data of the SCR inlet pollutant concentration field, so that the reducing agent distribution regulating unit performs real-time fine regulation based on the distribution regulating strategy. Through the cooperation of the time-sharing distributed measurement system, the control system and the reducing agent distribution adjusting unit, the high efficiency and the low ammonia escape rate of SCR denitration are finally realized, the consumption of the reducing agent is reduced, and the concentration of pollutants at the outlet of the system is reduced, so that good economic benefit and environmental protection benefit are realized.
In the reducing agent distribution regulating system provided by the embodiment of the invention, the time-sharing distributed measuring system can measure the NOx concentration of the sampling gas at the distributed sampling points of the cross section of the SCR inlet flue so as to obtain concentration distribution data of the NOx of the SCR inlet pollutants, the distribution regulating strategy of the reducing agent can be determined by the control system based on the concentration distribution data of the NOx of the SCR inlet pollutants, and then the reducing agent is distributed and regulated by the reducing agent distribution regulating unit based on the distribution regulating strategy of the reducing agent. Therefore, the reducing agent distribution regulating system provided by the embodiment of the invention can intelligently distribute the reducing agent according to the NOx concentration field data of the SCR inlet, accurately regulate the supply quantity of the reducing agent in real time, avoid overlarge ammonia nitrogen mixing deviation caused by uneven distribution of the NOx concentration field of the SCR inlet and incapability of tracking regulation of the supply quantity of the reducing agent due to working condition change, and finally cause phenomena of reduced denitration efficiency, excessive ammonia escape and the like. In addition, the distributed measurement system in the embodiment of the invention is a time-sharing distributed measurement system, so that the number of measurement devices in the system is reduced by the strategy of time-sharing measurement of the distributed measurement points, and the measurement cost is reduced.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
In the several embodiments provided in the present application, it should be understood that the disclosed methods, apparatuses, and devices may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown 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 may be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (8)
1. A reductant dispensing adjustment system, comprising:
the method comprises the steps of performing distributed sampling on the section of an SCR inlet flue, measuring NOx concentration data of sampling gas at distributed sampling points, and obtaining a distributed measurement system of SCR inlet NOx concentration field data;
a control system connected with the distributed measurement system for determining a distribution regulation strategy of the reducing agent based on the SCR inlet NOx concentration field data measured by the distributed measurement system, wherein the distribution regulation strategy comprises distribution regulation parameters of the reducing agent;
and a reducing agent distribution adjusting unit which is connected with the control system, is matched with the distributed measuring system, performs distribution adjustment on the reducing agent based on the distribution adjusting strategy, and feeds back a distribution adjusting result to the control system so that the control system adjusts the distribution adjusting strategy of the reducing agent based on the distribution adjusting result;
the control system optimizes an allocation adjustment strategy through autonomous learning according to the allocation adjustment result, wherein the allocation adjustment result comprises denitration efficiency;
in the debugging or initial running stage of the control system, if the NOx concentration of one target module in the catalyst modules is 1.5 times of the average value and the NOx concentrations of other modules are all the average value, the reducing agent distribution adjusting unit adjusts the opening of the adjusting valve corresponding to the module with the NOx concentration being the average value to 50% of the opening, and the opening of the adjusting valve corresponding to the target module is opened to the opening of the other valve when the flow is 1.5 times of the flow according to the flow opening characteristic curve;
when the control system finds that the denitration efficiency is not optimal based on the denitration efficiency fed back by the reducing agent distribution adjusting unit, the control system autonomously adjusts the opening of the adjusting valve corresponding to the target module to enable the opening to be larger than the opening of other valves by 1.5 times when the flow is increased, the denitration efficiency at the moment is compared with the denitration efficiency before the adjustment, if the denitration efficiency is improved, the opening of the adjusting valve is further increased, if the denitration efficiency is reduced, the opening of the adjusting valve is reduced, and the opening combination of the adjusting valves which are suitable for different NOx concentration fields at the SCR inlet is gradually found through continuous adjustment so as to achieve optimal adjustment.
2. The reductant dispensing adjustment system of claim 1, where the distributed measurement system is a time-division distributed measurement system that time-division samples the SCR inlet stack cross-section and measures NOx concentration data at time-division distributed sampling points.
3. The reductant dispensing adjustment system of claim 2, wherein the distributed measurement system includes:
the sampling system is used for carrying out distributed sampling on the section of the SCR inlet flue to obtain sampling gas of a plurality of distributed sampling points;
the time-sharing distributed switching device is connected with the sampling system and used for switching the distributed sampling points through a set switch so as to realize time-sharing measurement of different sampling points;
the sampling power unit is connected with the time-sharing distributed switching device and used for providing power for the sampling gas of the distributed sampling points;
and the measuring device is connected with the sampling power unit and used for measuring the sampling gas sent by the sampling power unit to obtain the data of the NOx concentration field at the SCR inlet.
4. A reductant dispensing adjustment system according to claim 3, characterized in that the measuring device comprises:
sampling probe for pumping the sampling gas by sampling pump and filtering and heating the pumped gas;
the heat tracing pipeline is connected with the sampling probe, and is used for conveying the gas sampled, filtered and heated by the sampling probe and carrying out high-temperature heat tracing on the conveyed gas;
the pretreatment device is connected with the heat tracing pipeline and used for cooling, drying and filtering the gas transmitted by the heat tracing pipeline to obtain the gas to be analyzed;
the NOx analyzer is connected with the pretreatment device and used for analyzing the concentration of NOx of the gas to be analyzed;
and the device is respectively connected with the sampling probe, the heat tracing pipeline, the pretreatment device and the NOx analyzer, and is used for controlling the sampling probe, the heat tracing pipeline, the pretreatment device and the NOx analyzer to extract, transmit, process and analyze the sampling gas.
5. The reductant dispensing adjustment system of claim 3, wherein the sampling power unit includes: the sampling power unit is used for sending the sampling gas of the distributed sampling points to the measuring device through the sampling pipeline.
6. The reductant dispensing adjustment system of claim 3, wherein the sampling system includes a plurality of sampling units, the sampling system performing distributed sampling of the SCR inlet stack cross-section by the plurality of sampling units to obtain the sampled gas at the distributed sampling points;
the allocation adjustment unit comprises:
a reducing agent distribution unit that distributes the reducing agent based on the distribution adjustment strategy, the same number of sampling points as the distributed sampling;
and reducing agent adjusting units, which are the same as the number of the reducing agent dispensing units, for adjusting the supply amount of the reducing agent based on the dispensing adjustment strategy.
7. The reductant dispensing adjustment system of claim 6, wherein the reductant adjustment unit is an adjustment valve;
the dispense adjustment parameters in the dispense adjustment strategy include an opening of the adjustment valve.
8. A reductant dispensing adjustment system according to claim 3, characterized in that the sampling means of the sampling system is a grid sampling.
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| CN110967452B (en) * | 2019-12-23 | 2021-03-12 | 北京国电龙源环保工程有限公司 | Layout method of gas measurement system |
| CN114577532B (en) * | 2022-01-18 | 2024-03-26 | 江苏众川生态环境有限公司 | Multiphase extraction monitoring sampling multifunctional well repairing system |
| CN114534458B (en) * | 2022-03-09 | 2023-04-07 | 山东爱亿普环保科技股份有限公司 | Control method and device for injecting denitration reducing agent |
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