CN111905539B - Boiler denitration ammonia injection automatic adjustment and optimization method and system - Google Patents
Boiler denitration ammonia injection automatic adjustment and optimization method and system Download PDFInfo
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Abstract
The application relates to a boiler denitration ammonia injection automatic regulation and optimization method and system, and relates to the field of boiler denitration, wherein the method comprises the steps of obtaining the amount of waste gas discharged by a boiler and the concentration of nitrogen oxide at an inlet of a denitration reactor, and multiplying the amount of the waste gas and the concentration of the nitrogen oxide to obtain the total content of the nitrogen oxide in the waste gas; acquiring the content of the discharged nitrogen oxides at a desulfurization outlet, and calculating the difference between the total content of the nitrogen oxides and the content of the discharged nitrogen oxides; and taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity catalytically reacting with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database to be injected into the denitration reactor. This application has the effect that improves the accuracy of spouting ammonia volume in the control denitration reactor.
Description
Technical Field
The application relates to the field of boiler denitration, in particular to an automatic adjustment and optimization method and system for ammonia injection in boiler denitration.
Background
Among the prior art, the device that spouts ammonia is carried out denitration to the produced waste gas of boiler 15 among generating set is as shown in fig. 6, including boiler 15, denitration reactor 16, air preheater 17 and desulfurization export 18, the produced waste gas of generating electricity passes through denitration reactor 16 in proper order in boiler 15, air preheater 17 and discharges through desulfurization export 18, when passing through denitration reactor 16, waste gas reacts with the ammonia that spouts, with the NOX content in the reduction waste gas, waste gas after the reaction carries out heat recovery through air preheater 17, discharge after the desulfurization again.
Aiming at the related technology, when nitrogen oxides in the waste gas are removed, ammonia gas is sprayed into the denitration reactor 16 to directly perform catalytic reaction with the nitrogen oxides, the amount of the ammonia gas needs to be controlled in the process of spraying the ammonia gas into the denitration reactor 16, the device directly detects the content of the nitrogen oxides contained in the waste gas at the inlet of the denitration reactor 16 and the nitrogen oxides at the outlet after reaction in the process of controlling the ammonia gas, the content of the nitrogen oxides needs to be reduced by making a difference between the two contents, and then ammonia gas with the corresponding content is sprayed according to the content of the nitrogen oxides to be reduced, but the content of the nitrogen oxides at the outlet of the denitration reactor 16 is directly used as a detection standard, so that the ammonia gas and the nitrogen oxides simultaneously overflow from the outlet of the denitration reactor 16 and react at the outlet, and further the detected content of the nitrogen oxides at the outlet of the denitration reactor 16 is higher or lower, so that the sprayed ammonia amount is controlled to be too high or too low, and the accuracy of ammonia spraying is reduced.
Disclosure of Invention
In order to improve the accuracy of controlling the ammonia injection amount in the denitration reactor, the application provides a boiler denitration ammonia injection automatic adjustment optimization method and system.
In a first aspect, the application provides a boiler denitration ammonia injection automatic adjustment and optimization method, which adopts the following technical scheme:
an automatic adjustment and optimization method for denitration ammonia injection of a boiler comprises the following steps:
obtaining the amount of waste gas discharged by a boiler and the concentration of nitrogen oxides at an inlet of a denitration reactor, and multiplying the amount of the waste gas and the concentration of the nitrogen oxides to obtain the total content of the nitrogen oxides in the waste gas;
acquiring the content of the discharged nitrogen oxides at a desulfurization outlet, and calculating the difference between the total content of the nitrogen oxides and the content of the discharged nitrogen oxides;
and taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity which is catalytically reacted with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database to be injected into the denitration reactor.
Through adopting above-mentioned technical scheme, through the nitrogen oxide exhaust content who obtains the SOx outlet department, and calculate the difference of the nitrogen oxide exhaust content of the nitrogen oxide content of denitration reactor entrance and SOx outlet department, come as the volume that needs carry out catalytic reaction through liquid ammonia, corresponding ammonia volume of spouting is selected from spouting ammonia volume database again, can make the nitrogen oxide that goes out from the denitration reactor export and liquid ammonia complete reaction, reduce the residue of unnecessary nitrogen oxide in the nitrogen oxide exhaust content, and then can improve the accuracy of spouting the ammonia volume in the control denitration reactor.
Preferably, the method further comprises the following steps:
acquiring the emission content of nitrogen oxides at the outlet of the denitration reactor, and calculating the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides;
when the difference value between the nitrogen oxide emission content and the nitrogen oxide emission content is smaller than a preset difference value threshold value;
and calculating the difference value between the emission content of the nitrogen oxides and the total content of the nitrogen oxides, taking the difference value as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity which is subjected to catalytic reaction with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database to be injected into the denitration reactor.
By adopting the technical scheme, the content of the nitrogen oxide discharged at the outlet of the denitration reactor is detected, and is compared with the content of the nitrogen oxide discharged, and after the difference value between the content of the nitrogen oxide discharged and the content of the nitrogen oxide discharged is determined to be smaller than the difference threshold value, the content of the nitrogen oxide contained in the content of the nitrogen oxide discharged at the outlet of the denitration reactor is negligible, so that the content of the nitrogen oxide discharged can be used as the standard for controlling liquid ammonia, and the nitrogen oxide is reduced to remain in devices such as an air preheater in the process of moving to the desulfuration outlet.
Preferably, after calculating the difference between the content of nitrogen oxide discharged and the content of nitrogen oxide discharged, the method further includes:
when the difference value between the content of the discharged nitrogen oxides and the content of the discharged nitrogen oxides is greater than a preset difference threshold value;
recording the cleaning times of the condition that the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is more than the emission content of the nitrogen oxide;
and when the cleaning times are larger than a preset cleaning time threshold value, cleaning the air preheater and reducing the ammonia spraying amount.
By adopting the technical scheme, when the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide and then the emission content of the nitrogen oxide is smaller than the emission content of the nitrogen oxide, the situation that the emission content of the nitrogen oxide is smaller than the emission content of the nitrogen oxide is generated, the emission content of the nitrogen oxide is increased, the ammonia injection amount easily causes the excessive amount of the liquid ammonia entering the air preheater, the ammonium bisulfate generated by the reaction of the ammonia and the sulfur trioxide in the air preheater is adhered to the heat exchange sheet, the air preheater is blocked, the residual amount of the nitrogen oxide in devices such as the air preheater is large, the air preheater can be cleaned to reduce the blockage of the air preheater when the corresponding cleaning times are continuously reached, the ammonia injection amount is reduced to balance the emission content and the emission content of the nitrogen oxide, and the excessive ammonia can be reduced or the ammonia injection amount can be increased to clean the residual nitrogen oxide, and the nitrogen oxide is discharged into the air.
Preferably, the method further comprises the following steps:
recording the regulating times of the condition that the emission content of the nitrogen oxides is greater than the emission content of the nitrogen oxides after the emission content of the nitrogen oxides is less than the emission content of the nitrogen oxides;
and when the adjusting times are larger than a preset adjusting time threshold value, the ammonia spraying amount is increased.
Through adopting above-mentioned technical scheme, when nitrogen oxide emission content produces nitrogen oxide emission content and is greater than the nitrogen oxide emission content condition after being less than nitrogen oxide emission content, then show that the liquid ammonia volume that begins to spout is more or the nitrogen oxide content that the boiler discharged reduces, it leads to later to have reduced the ammonia injection volume, and under the condition that nitrogen oxide lasts to produce, it easily leads to nitrogen oxide unreacted complete and get into in the air to reduce the ammonia injection volume, can be when lasting reaching corresponding regulation number of times this moment, improve the ammonia injection volume, in order to neutralize nitrogen oxide, and then reduce after the condition that ammonia escaped to appear and spout the ammonia volume and lead to, the accessible reduces the ammonia injection volume this moment, in order to reduce liquid ammonia nitrogen oxide and arrange to the air.
Preferably, the adjusting the ammonia injection amount includes adjusting a boiler load to adjust the amount of exhaust gas or adjusting an opening degree of an ammonia injection valve.
Through adopting above-mentioned technical scheme, adjust boiler load for increasing or reducing the waste gas volume to increase or reduce nitrogen oxide content, and then increase or reduce liquid ammonia injection volume, adjust the aperture that spouts the ammonia valve and can increase or reduce liquid ammonia injection volume equally.
Preferably, when obtaining the content of nitrogen oxides at the desulfurization outlet and the denitration reactor outlet, the method includes:
dividing a desulfurization outlet and a denitration reactor outlet into a plurality of nitrogen oxide content detection areas;
acquiring the content of nitrogen oxides passing through each detection area, and sequencing the detection areas according to the content of the nitrogen oxides;
taking the content of the nitrogen oxides corresponding to the detection areas positioned in the middle positions in the detection areas as a reference, and sequentially calculating the difference value between the content of the nitrogen oxides in each detection area and the reference content of the nitrogen oxides;
and deleting the detection areas with the difference value between the content of the nitrogen oxides and the reference content of the nitrogen oxides larger than a preset difference threshold value, and calculating the average value of the content of the nitrogen oxides in the residual detection areas to serve as the content of the nitrogen oxides at the corresponding outlet.
Through adopting above-mentioned technical scheme, cover desulfurization export and denitration reactor export through setting up a plurality of detection area to reduce the condition to nitrogen oxide content local detection, and then can improve the accuracy of the nitrogen oxide content that desulfurization export and denitration reactor export detected.
The second aspect, this application provides a boiler denitration spouts ammonia automatically regulated optimization system, adopts following technical scheme:
the utility model provides a boiler denitration spouts ammonia automatically regulated optimization system, includes:
the first acquisition module is used for acquiring the amount of the waste gas discharged by the boiler and the concentration of the nitrogen oxide at the inlet of the denitration reactor, and multiplying the amount of the waste gas and the concentration of the nitrogen oxide to obtain the total content of the nitrogen oxide in the waste gas;
the second acquisition module is used for acquiring the content of the discharged nitric oxide at the desulfurization outlet and calculating the difference between the total content of the nitric oxide and the content of the discharged nitric oxide;
the setting module is used for taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides;
and the first adjusting module is used for selecting the ammonia spraying amount catalytically reacted with the corresponding nitrogen oxide reaction amount from a preset ammonia spraying amount database and spraying the ammonia spraying amount into the denitration reactor.
Preferably, the method further comprises the following steps:
the third acquisition module is used for acquiring the emission content of the nitrogen oxides at the outlet of the denitration reactor and calculating the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides;
and the second adjusting module is used for calculating the difference value between the emission content of the nitrogen oxides and the total content of the nitrogen oxides when the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides is smaller than a preset difference value threshold value, taking the difference value as the reaction quantity of the nitrogen oxides, and selecting the ammonia spraying quantity catalytically reacted with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia spraying quantity database to spray into the denitration reactor.
Preferably, the method further comprises the following steps:
the first recording module is used for recording the cleaning times when the nitrogen oxide emission content is smaller than the nitrogen oxide emission content after being larger than the nitrogen oxide emission content when the difference value between the nitrogen oxide emission content and the nitrogen oxide emission content is larger than a preset difference value threshold value;
the first adjusting module is used for cleaning the air preheater and reducing the ammonia spraying amount when the cleaning times are larger than a preset cleaning time threshold value;
the second recording module is used for recording the adjusting times of the condition that the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide when the difference value between the emission content of the nitrogen oxide and the emission content of the nitrogen oxide is greater than a preset difference value threshold;
and the second adjusting module is used for increasing the ammonia spraying amount when the adjusting times are larger than a preset adjusting time threshold value.
Preferably, the method further comprises the following steps:
the region dividing module is used for dividing the desulfurization outlet and the denitration reactor outlet into a plurality of nitrogen oxide content detection regions;
the detection module is used for acquiring the content of the nitrogen oxides passing through each detection area and sequencing the detection areas according to the content of the nitrogen oxides;
the first calculation module is used for sequentially calculating the difference value between the content of the nitrogen oxide in each detection area and the content of the reference nitrogen oxide by taking the content of the nitrogen oxide corresponding to the detection area positioned at the middle position in the detection areas as the reference;
and the second calculation module is used for deleting the detection area with the difference value between the content of the nitrogen oxides and the reference nitrogen oxide content larger than the preset difference threshold value, and calculating the average value of the content of the nitrogen oxides in the residual detection areas to be used as the content of the nitrogen oxides in the corresponding outlet.
In summary, the present application includes at least one of the following beneficial technical effects:
through the nitrogen oxide exhaust content who obtains the desulfurization exit to calculate the difference of the nitrogen oxide content of denitration reactor entrance and the nitrogen oxide exhaust content at desulfurization exit, come as the volume that needs carry out catalytic reaction through liquid ammonia, surplus nitrogen oxide's among the reducible nitrogen oxide exhaust content remains, and then can improve the accuracy of spouting ammonia volume in the control denitration reactor.
Drawings
Fig. 1 is a schematic diagram one of the present application.
Fig. 2 is a schematic diagram of the second principle of the present application.
Fig. 3 is a schematic diagram of the third embodiment of the present invention.
Fig. 4 is a schematic diagram of the present application.
Fig. 5 is a schematic structural diagram of the present application.
FIG. 6 is a schematic structural diagram of a prior art denitration and desulfurization apparatus for boiler exhaust gas.
Description of the reference numerals: 1. a first acquisition module; 2. a second acquisition module; 3. a setting module; 4. a first adjustment module; 5. a third obtaining module; 6. a second conditioning module; 7. a first recording module; 8. a first adjusting module; 9. a second recording module; 10. a second adjustment module; 11. a region dividing module; 12. a detection module; 13. a first calculation module; 14. a second calculation module; 15. a boiler; 16. a denitration reactor; 17. an air preheater; 18. and a desulfurization outlet.
Detailed Description
The present application is described in further detail below with reference to figures 1-6.
The embodiment of the application discloses boiler denitration ammonia injection automatic adjustment optimization method, referring to fig. 1, specifically including the following steps:
and S100, acquiring the amount of the waste gas discharged by the boiler and the concentration of the nitrogen oxide at the inlet of the denitration reactor, and multiplying the amount of the waste gas and the concentration of the nitrogen oxide to obtain the total content of the nitrogen oxide in the waste gas.
Specifically, the total amount of the exhaust gas discharged from the boiler and the concentration of the nitrogen oxide at the inlet of the denitration reactor are respectively detected, and the product of the amount of the exhaust gas and the concentration of the nitrogen oxide is used as the total content of the nitrogen oxide to be subjected to denitration and desulfurization.
And step S200, acquiring the content of the nitrogen oxide discharged at the desulfurization outlet, and calculating the difference between the total content of the nitrogen oxide and the content of the nitrogen oxide discharged.
Specifically, the nitrogen oxide discharged from the desulfurization outlet is discharged after being subjected to ammonia spraying and denitration by the denitration reactor, heat is recovered by the air preheater and finally desulfurized by the desulfurization outlet, the discharged content of the discharged nitrogen oxide is the standard content of the nitrogen oxide which can be discharged into the environment, and then the difference between the total content of the nitrogen oxide which needs to be subjected to denitration and desulfurization and the discharged content of the nitrogen oxide which can be discharged is calculated and used as the content of the nitrogen oxide which needs to be removed.
And step S300, taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity which is catalytically reacted with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database and injecting the ammonia injection quantity into the denitration reactor.
Specifically, the reaction amount of the nitrogen oxide is the content of the nitrogen oxide which needs to be catalytically reacted by filling liquid ammonia after entering the denitration reactor, in this embodiment, by setting the ammonia injection amount database and storing liquid ammonia content data corresponding to the nitrogen oxide content data in the ammonia injection amount database, that is, each nitrogen oxide content data corresponds to liquid ammonia content data capable of completely catalytically reacting the nitrogen oxide under the content; and then after the reaction amount of the nitrogen oxide is calculated, liquid ammonia with the corresponding content can be directly filled into the denitration reactor according to the corresponding liquid ammonia content data to perform catalytic reaction with the nitrogen oxide.
Referring to fig. 2, further, after the catalytic reaction of the denitration reactor, nitrogen oxide still exists in the exhaust gas overflowing from the outlet of the denitration reactor, and in the process of moving to the desulfurization outlet, the nitrogen oxide may remain in the air preheater, so that the content of the nitrogen oxide detected by the desulfurization outlet is relatively low, and further, the content of the injected liquid ammonia is relatively high, thereby further improving the accuracy of the content of the liquid ammonia required to be injected.
The application also includes:
and S400, acquiring the emission content of the nitrogen oxide at the outlet of the denitration reactor, and calculating the difference between the emission content of the nitrogen oxide and the emission content of the nitrogen oxide.
Specifically, the nitrogen oxide content of discharging at direct detection denitration reactor exit compares in the nitrogen oxide content of discharging that detects the desulfurization export, and nitrogen oxide content of discharging can more react out the volume that nitrogen oxide was catalyzed in the denitration reactor fast, later calculates the difference between nitrogen oxide content of discharging and the nitrogen oxide content of discharging.
Step S410, when the difference value between the nitrogen oxide emission content and the nitrogen oxide emission content is smaller than a preset difference value threshold value.
And S411, calculating a difference value between the emission content of the nitrogen oxides and the total content of the nitrogen oxides and taking the difference value as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity which is catalytically reacted with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database and injecting the ammonia injection quantity into the denitration reactor.
Specifically, the difference threshold is preferably a standard that can use the nitrogen oxide emission content as a calculation standard for determining the nitrogen oxide reaction amount, that is, when the difference between the nitrogen oxide emission content and the nitrogen oxide emission content is smaller than a preset difference threshold, it indicates that the amount of the nitrogen oxide remaining in the air preheater or the like is small or even negligible in the process of reaching the desulfurization outlet, and at this time, the nitrogen oxide emission content can be used as the calculation standard for the nitrogen oxide reaction amount, the nitrogen oxide emission content is directly subtracted from the total content of the nitrogen oxide to serve as the nitrogen oxide reaction amount, so as to increase the nitrogen oxide catalytic reaction amount in the denitrification reactor, and reduce the nitrogen oxide that continues to remain in the air preheater after being discharged from the denitrification reactor outlet and in the process of reaching the desulfurization outlet.
Referring to fig. 3, in step S420, when the difference between the content of the discharged nox and the content of the discharged nox is greater than a predetermined difference threshold.
Specifically, the difference between the nitrogen oxide emission content and the nitrogen oxide emission content may be obtained by subtracting the nitrogen oxide emission content from the nitrogen oxide emission content, or by subtracting the nitrogen oxide emission content from the nitrogen oxide emission content, and when the difference between the nitrogen oxide emission content and the nitrogen oxide emission content is greater than a preset difference threshold, it indicates that the nitrogen oxide is more in amount remaining in the air preheater or other devices in the process of reaching the desulfurization outlet.
And step S421, recording the cleaning times when the nitrogen oxide emission content is less than the nitrogen oxide emission content after the nitrogen oxide emission content is greater than the nitrogen oxide emission content.
And S422, when the cleaning frequency is greater than the preset cleaning frequency threshold value, cleaning the air preheater and reducing the ammonia spraying amount.
Specifically, when the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide, the emission content of the liquid ammonia which is sprayed at the beginning is less or the emission content of the nitrogen oxide of the boiler is more, when the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide, the subsequent increase of the ammonia spraying amount is indicated, the increased ammonia spraying amount reacts with the nitrogen oxide more, a part of the ammonia spraying amount also enters the air preheater, after the ammonia spraying amount continues for multiple times, the liquid ammonia amount in the air preheater is increased, the liquid ammonia in the air preheater is excessive, ammonium bisulfate generated by the reaction of the excessive liquid ammonia and sulfur trioxide is adhered to a heat exchange sheet of the air preheater, the blockage of the air preheater is easy to cause, at the moment, the air preheater can be cleaned when the corresponding cleaning times are continuously reached, so as to reduce the blockage of the air preheater, the ammonia spraying amount is reduced so as to balance the emission content and the emission content, and the excessive ammonia can be simultaneously reduced to enter the air preheater or be discharged into the air.
And step S423, recording the adjusting times of the condition that the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide.
In step S424, when the adjustment times are greater than the preset adjustment time threshold, the ammonia injection amount is increased.
Specifically, when the emission content of nitrogen oxides is less than the emission content of nitrogen oxides, the emission content of liquid ammonia which is injected at the beginning is large or the content of nitrogen oxides discharged from a boiler is small, when the emission content of nitrogen oxides is greater than the emission content of nitrogen oxides, the ammonia injection amount is reduced subsequently, and under the condition that nitrogen oxides are continuously generated, the reduction of the ammonia injection amount easily causes that nitrogen oxides are not completely reacted and enter the air, and at the moment, when the threshold value of the adjustment times is continuously reached, the ammonia injection amount is increased to neutralize the nitrogen oxides, so that the emission of nitrogen oxides to the air can be reduced.
When the ammonia injection amount is adjusted, the load of the boiler is adjusted to adjust the waste gas amount or adjust the opening degree of the ammonia injection valve, specifically, the load of the boiler is adjusted to increase or reduce the waste gas amount so as to increase or reduce the content of nitrogen oxides, and further increase or reduce the injection amount of liquid ammonia, and the opening degree of the ammonia injection valve is adjusted to increase or reduce the injection amount of liquid ammonia.
Referring to fig. 4, when acquiring the contents of nitrogen oxides at the desulfurization outlet and the denitration reactor outlet, the method specifically includes the following steps for improving the accuracy of the acquired contents of nitrogen oxides:
and S500, dividing the desulfurization outlet and the denitration reactor outlet into a plurality of nitrogen oxide content detection areas.
Specifically, the same number of detection areas are uniformly divided in the circumferential direction of the desulfurization outlet and the denitration reactor outlet, so that the whole desulfurization outlet and the denitration reactor outlet are completely covered by detection, and the detection of the content of local nitrogen oxides is avoided.
Step S510, acquiring the content of the nitrogen oxides passing through each detection area, and sequencing the detection areas according to the content of the nitrogen oxides.
Step S520, sequentially calculating a difference between the content of nitrogen oxide in each detection region and a reference content of nitrogen oxide based on the content of nitrogen oxide corresponding to the detection region located at the middle position in the plurality of detection regions.
Specifically, the nitrogen oxide contents of the detection areas obtained from the two outlets of the desulfurization outlet and the denitration reactor outlet are respectively sorted from large to small, and the nitrogen oxide content at the middle position in each outlet after sorting is taken as a reference, for example, if the detection area is divided into five, the nitrogen oxide content taken as the reference is the third; and then calculating the difference between the other four detected nitrogen and oxygen contents and the third reference nitrogen and oxide content, and obtaining four specific difference data.
In step S530, the detection areas where the difference between the content of the nitrogen oxide and the reference content of the nitrogen oxide is greater than the preset difference threshold are deleted, and the average value of the content of the nitrogen oxide in the remaining detection areas is calculated to be the content of the nitrogen oxide in the corresponding outlet.
Specifically, the difference threshold is preferably a standard for judging whether the content of the nitrogen oxide detected by the detection area is calculated as the content of the nitrogen oxide at the outlet of the desulfurization outlet or the outlet of the denitrification reactor, the four specific difference data are respectively compared with the size of the difference threshold, data larger than the difference threshold in the four specific difference data are deleted, the content of the nitrogen oxide detected by the corresponding detection area is further deleted, and finally, the average value of the content of the nitrogen oxide corresponding to the remaining detection area is calculated and is used as the content of the nitrogen oxide at the outlet of the desulfurization outlet or the denitrification reactor.
The embodiment of the application also discloses an automatic adjustment and optimization system for denitration ammonia injection of a boiler, which refers to fig. 5 and comprises a first acquisition module 1, a second acquisition module 2, a setting module 3 and a first adjustment module 4; the first obtaining module 1 is configured to obtain an amount of the exhaust gas discharged from the boiler 15 and a concentration of nitrogen oxide at an inlet of the denitration reactor 16, and multiply the amount of the exhaust gas and the concentration of nitrogen oxide to obtain a total content of nitrogen oxide in the exhaust gas; the second obtaining module 2 is used for obtaining the nitrogen oxide emission content at the desulfurization outlet 18 and calculating the difference between the total nitrogen oxide content and the nitrogen oxide emission content; the setting module 3 is used for taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides; the first adjusting module 4 selects the ammonia injection amount catalytically reacted with the corresponding nitrogen oxide reaction amount from a preset ammonia injection amount database and injects the ammonia injection amount into the denitration reactor 16, and the ammonia injection amount database stores the ammonia injection amount data corresponding to the nitrogen oxide reaction amount.
Further, since nitrogen oxide still exists in the exhaust gas overflowing from the outlet of the denitration reactor 16 after the catalytic reaction of the denitration reactor 16, in the process of moving to the desulfurization outlet 18, the nitrogen oxide may remain in the air preheater 17, so that the content of the nitrogen oxide detected by the desulfurization outlet 18 is relatively low, and further, the content of the injected liquid ammonia is relatively high, thereby further improving the accuracy of the content of the liquid ammonia required to be injected.
The application also comprises a third acquisition module 5, a second regulation module 6, a first recording module 7, a first regulation module 8, a second recording module 9 and a second regulation module 10; the third obtaining module 5 is configured to obtain nitrogen oxide emission content at an outlet of the denitration reactor 16, and calculate a difference between the nitrogen oxide emission content and the nitrogen oxide emission content; when the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides is smaller than a preset difference threshold value, the second adjusting module 6 calculates the difference value between the emission content of the nitrogen oxides and the total content of the nitrogen oxides to be used as the reaction amount of the nitrogen oxides, and selects the ammonia injection amount which is in catalytic reaction with the corresponding reaction amount of the nitrogen oxides from a preset ammonia injection amount database to be injected into the denitration reactor 16.
When the difference value between the emission content of the nitrogen oxide and the emission content of the nitrogen oxide is greater than a preset difference value threshold value, the first recording module 7 records the cleaning times when the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide and then the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide; when the cleaning times are larger than a preset cleaning time threshold value, the first adjusting module 8 cleans the air preheater 17 and reduces the ammonia spraying amount; when the difference value between the emission content of the nitrogen oxide and the emission content of the nitrogen oxide is greater than a preset difference threshold value, the second recording module 9 records the adjusting times of the condition that the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide; when the adjustment times are larger than the preset adjustment time threshold value, the second adjustment module 10 increases the ammonia injection amount.
Further, when the content of nitrogen oxide at the outlet of the desulfurization outlet 18 and the outlet of the denitration reactor 16 is obtained, in order to improve the accuracy of the obtained content of nitrogen oxide, the device further comprises a region division module 11, a detection module 12, a first calculation module 13 and a second calculation module 14.
The region dividing module 11 is used for dividing the desulfurization outlet 18 and the outlet of the denitration reactor 16 into a plurality of nitrogen oxide content detection regions; the detection module 12 is configured to obtain the content of nitrogen oxide passing through each detection area, and sort the detection areas according to the size of the content of nitrogen oxide; the first calculating module 13 is configured to sequentially calculate a difference value between the content of nitrogen oxide in each detection area and a reference content of nitrogen oxide based on the content of nitrogen oxide corresponding to the detection area located at the middle position in the plurality of detection areas; the second calculating module 14 is configured to delete the detection areas where the difference between the content of the nitrogen oxide and the reference content of the nitrogen oxide is greater than the preset difference threshold, and calculate an average value of the content of the nitrogen oxide in the remaining detection areas to serve as the content of the nitrogen oxide at the corresponding outlet.
The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: equivalent changes in structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (5)
1. A boiler denitration ammonia injection automatic regulation and optimization method is characterized by comprising the following steps: the method comprises the following steps:
obtaining the amount of waste gas discharged by a boiler and the concentration of nitrogen oxides at an inlet of a denitration reactor, and multiplying the amount of the waste gas and the concentration of the nitrogen oxides to obtain the total content of the nitrogen oxides in the waste gas;
acquiring the content of the discharged nitrogen oxides at a desulfurization outlet, and calculating the difference between the total content of the nitrogen oxides and the content of the discharged nitrogen oxides;
taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity which is catalytically reacted with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database and injecting the ammonia injection quantity into the denitration reactor;
further comprising:
acquiring the emission content of nitrogen oxides at the outlet of the denitration reactor, and calculating the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides;
when the difference value between the nitrogen oxide emission content and the nitrogen oxide emission content is smaller than a preset difference value threshold value;
calculating the difference value between the emission content of the nitrogen oxides and the total content of the nitrogen oxides and taking the difference value as the reaction quantity of the nitrogen oxides, and selecting the ammonia injection quantity which is catalytically reacted with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database and injecting the ammonia injection quantity into the denitration reactor;
after the difference between the nitrogen oxide emission content and the nitrogen oxide emission content is calculated, the method further comprises the following steps:
when the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides is larger than a preset difference threshold value;
recording the cleaning times of the condition that the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is more than the emission content of the nitrogen oxide;
when the cleaning times are larger than a preset cleaning time threshold value, cleaning the air preheater and reducing the ammonia spraying amount;
further comprising:
recording the adjusting times of the condition that the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide;
and when the adjusting times are larger than a preset adjusting time threshold value, the ammonia spraying amount is increased.
2. The boiler denitration ammonia injection automatic adjustment and optimization method according to claim 1, characterized in that: when the ammonia injection amount is regulated, the load of the boiler is regulated to regulate the waste gas amount or regulate the opening degree of an ammonia injection valve.
3. The boiler denitration ammonia injection automatic adjustment and optimization method according to claim 1, characterized in that: when obtaining the nitrogen oxide content at desulfurization exit and denitration reactor exit, include:
dividing a desulfurization outlet and a denitration reactor outlet into a plurality of nitrogen oxide content detection areas;
acquiring the content of nitrogen oxides passing through each detection area, and sequencing the detection areas according to the content of the nitrogen oxides;
taking the content of the nitrogen oxides corresponding to the detection areas positioned in the middle positions in the detection areas as a reference, and sequentially calculating the difference value between the content of the nitrogen oxides in each detection area and the reference content of the nitrogen oxides;
and deleting the detection areas with the difference value of the content of the nitrogen oxides and the reference content of the nitrogen oxides larger than a preset difference threshold value, and calculating the average value of the content of the nitrogen oxides in the residual detection areas to be used as the content of the nitrogen oxides at the corresponding outlet.
4. The utility model provides a boiler denitration spouts ammonia automatically regulated optimization system which characterized in that: the method comprises the following steps:
the first acquisition module (1) is used for acquiring the amount of the waste gas discharged by the boiler (15) and the concentration of the nitrogen oxides at an inlet of the denitration reactor (16), and multiplying the amount of the waste gas and the concentration of the nitrogen oxides to obtain the total content of the nitrogen oxides in the waste gas;
the second acquisition module (2) is used for acquiring the nitrogen oxide emission content at the desulfurization outlet (18) and calculating the difference value between the total nitrogen oxide content and the nitrogen oxide emission content;
the setting module (3) is used for taking the difference value of the total content of the nitrogen oxides and the discharge content of the nitrogen oxides as the reaction quantity of the nitrogen oxides;
the first adjusting module (4) selects the ammonia injection amount catalytically reacted with the corresponding nitrogen oxide reaction amount from a preset ammonia injection amount database and injects the ammonia injection amount into the denitration reactor (16);
further comprising:
the third acquisition module (5) is used for acquiring the emission content of the nitrogen oxides at the outlet of the denitration reactor (16) and calculating the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides;
the second adjusting module (6) is used for calculating the difference value between the emission content of the nitrogen oxides and the total content of the nitrogen oxides to be used as the reaction quantity of the nitrogen oxides when the difference value between the emission content of the nitrogen oxides and the emission content of the nitrogen oxides is smaller than a preset difference value threshold, and selecting the ammonia injection quantity which is in catalytic reaction with the corresponding reaction quantity of the nitrogen oxides from a preset ammonia injection quantity database to be injected into the denitration reactor (16);
further comprising:
the first recording module (7) is used for recording the cleaning times of the condition that the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide when the difference value between the emission content of the nitrogen oxide and the emission content of the nitrogen oxide is greater than a preset difference value threshold;
the first adjusting module (8) is used for cleaning the air preheater (17) and reducing the ammonia spraying amount when the cleaning times are larger than a preset cleaning time threshold value;
the second recording module (9) is used for recording the adjusting times of the condition that the emission content of the nitrogen oxide is greater than the emission content of the nitrogen oxide after the emission content of the nitrogen oxide is less than the emission content of the nitrogen oxide when the difference value between the emission content of the nitrogen oxide and the emission content of the nitrogen oxide is greater than a preset difference value threshold;
and the second adjusting module (10) is used for increasing the ammonia spraying amount when the adjusting times are larger than a preset adjusting time threshold value.
5. The boiler denitration ammonia injection automatic adjustment and optimization system of claim 4, characterized in that: further comprising:
the region dividing module (11) is used for dividing the desulfurization outlet (18) and the outlet of the denitration reactor (16) into a plurality of nitrogen oxide content detection regions;
the detection module (12) is used for acquiring the content of the nitrogen oxides passing through each detection area and sequencing the detection areas according to the content of the nitrogen oxides;
the first calculation module (13) is used for sequentially calculating the difference value between the content of the nitrogen oxide in each detection area and the content of the reference nitrogen oxide by taking the content of the nitrogen oxide corresponding to the detection area positioned at the middle position in the detection areas as the reference;
and the second calculation module (14) deletes the detection area with the difference value between the content of the nitrogen oxide and the content of the reference nitrogen oxide larger than the preset difference threshold value, and calculates the average value of the content of the nitrogen oxide in the residual detection areas to be used as the content of the nitrogen oxide of the corresponding outlet.
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