CN108896510B - SCR outlet ammonia concentration plane distribution online detection system and method - Google Patents
SCR outlet ammonia concentration plane distribution online detection system and method Download PDFInfo
- Publication number
- CN108896510B CN108896510B CN201810450936.2A CN201810450936A CN108896510B CN 108896510 B CN108896510 B CN 108896510B CN 201810450936 A CN201810450936 A CN 201810450936A CN 108896510 B CN108896510 B CN 108896510B
- Authority
- CN
- China
- Prior art keywords
- laser
- flue gas
- concentration
- flue
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Optics & Photonics (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses an on-line detection system and method for ammonia concentration planar distribution at an SCR outlet. The detection system comprises a sampling module, a flue gas pretreatment module, a laser detection module and a data processing module; after the sampling module performs gridding sampling in the flue above two sides, the multiple paths of flue gas are simultaneously introduced into the flue gas pretreatment module for dust removal and other measurement pretreatment, the laser detection module simultaneously performs laser detection on the multiple paths of flue gas, and the NH of each path of flue gas is synchronously calculated by the multiple paths of detection signals through the data processing module 3 Concentration value, obtain NH 3 The planar distribution of the concentration results. The invention can accurately measure the NH of the outlet of the SCR denitration system 3 Concentration. The detection signals of all paths of flue gas can occur simultaneously, the data acquisition and processing are sequentially carried out according to the set sequence, the time interval between the acquisition and processing of two adjacent paths of data is not more than 5s, the grid detection period is greatly shortened, and the equipment cost and the maintenance cost are obviously reduced.
Description
Technical Field
The invention relates to a thermal power plant denitration system operation optimization technology in the technical field of environmental protection, in particular to an SCR outlet ammonia concentration plane distribution on-line detection system.
Background
With the increasing severity of NOx emissions pollution, the national demands on NOx emissions are more stringent. The Selective Catalytic Reduction (SCR) technology is a flue gas denitration technology adopted by most coal-fired power plants at present, and the main principle is NH 3 As a reducing agent, with NOx as a pollutant in the flue gasReduction to non-toxic and pollution-free N 2 And H 2 And O, thereby meeting the national requirements for flue gas emission. The ammonia spraying amount is controlled when the flue gas denitration device is operated, so that the maximum removal of NOx is ensured, and NH is ensured 3 The escape rate of (2) is controlled within a reasonable range. If the ammonia injection amount is too small, the denitration efficiency is low, so that the concentration of NOx in the flue gas is too high and exceeds the emission standard limit value; excessive ammonia spraying amount, and escaped ammonia gas can be mixed with SO in the flue gas 3 The formation of ammonium sulfate salts, which are corrosive and cohesive, causes clogging and corrosion of the heat storage elements of the air preheater located downstream of the denitration. Meanwhile, escaped ammonia can also corrode the catalyst module, so that the catalyst is deactivated and blocked, and the service life of the catalyst is greatly reduced. Therefore, the ammonia escape amount is detected rapidly and accurately, and the method is important to improving the operation efficiency of the SCR device and ensuring the operation safety of the system and the denitration economy.
The tunable diode absorption spectroscopy (TDLAS) technology, which is a high-selectivity, high-sensitivity and high-precision rapid online detection technology, is often applied to the NH of an SCR outlet 3 And (5) detecting the concentration on line.
Existing NH based on TDLAS technology 3 The escape on-line detection system or the on-line analyzer generally adopts single-point measurement, but the flow field of the flue gas in the actual flue is quite uneven, and NH is not uniform 3 There is also a large gradient in the concentration profile of the existing NH 3 The concentration measurement data is poor in representativeness, cannot meet the requirement of fine adjustment of the SCR system, and cannot realize partition optimization adjustment of the ammonia injection grid. If NH is to be achieved 3 On-line measurement of concentration plane distribution in a flue reflects the real condition of ammonia escape of the SCR denitration device, and a plurality of TDLAS gas on-line detection systems are required to be correspondingly configured, so that the system has low use efficiency and wastes resources. Compared with the existing online detection system or analyzer, the invention overcomes the defects and aims at NH 3 Under the condition of uneven concentration plane distribution in a flue, by adopting the arrangement scheme of the grid type multipoint sampling heads, one set of system can realize the simultaneous on-line detection of the concentration of the flue gas at a plurality of sampling points, thereby not only shortening the detection period, but also greatly reducing the equipment investment cost and equipmentMaintenance costs.
Disclosure of Invention
The invention aims to solve the problems of low TDLAS concentration online single-point measurement efficiency, high cost, large maintenance amount and non-representative single-point measurement result of escaped ammonia in an SCR denitration device of a coal-fired power plant, provides an ammonia concentration plane distribution online detection system, and realizes that one detection system simultaneously detects NH in grid-type multipoint sampling flue gas 3 Concentration, concentration distribution of escaped ammonia in the SCR denitration device is obtained, gas concentration detection efficiency is improved, and equipment cost and maintenance cost required for detecting gas concentration are reduced.
The object of the invention is achieved by at least one of the following technical solutions.
An SCR outlet ammonia concentration plane distribution on-line detection system comprises two sampling modules (100A, 100B), two flue gas pretreatment modules (200A, 200B), a laser detection module (300) and a data processing and display module; the two sampling modules (100A, 100B) and the two flue gas pretreatment modules (200A, 200B) are respectively arranged on the flues at two sides; the sampling module, the flue gas pretreatment module and the laser detection module which are positioned on each side flue are sequentially connected through the heat tracing pipe, and the laser detection module is connected with the data processing and display module. The flue gas pretreatment module is used for pretreating the flue gas to enable the flue gas to meet the measurement requirements; the laser detection module adjusts the frequency of the laser to NH 3 At the center frequency of the absorption line, the laser generates incident laser light; the incident laser is split, and the split laser is collimated by an optical fiber collimator and then is incident into a gas absorption tank; the flue gas in the gas absorption tank absorbs the flue gas to generate NH 3 The gas absorbs the light signal, and the corresponding detection is carried out through each photoelectric detector to obtain a plurality of paths of NH containing the detected gas 3 The optical signal of the concentration information is converted into an electric signal for data processing, and the electric signal is amplified by a built-in pre-amplifying circuit; then the NH in the flue gas of each path is reflected by the upper computer 3 Concentration value of (2) to obtain NH 3 The planar distribution result of the concentration is calculated out simultaneously 3 Average value of concentration.
Further, each sampling module comprises n high-temperature sampling guns positioned on the flue at the corresponding side and an electromagnetic valve group corresponding to the high-temperature sampling guns; the high-temperature sampling guns are connected with the corresponding electromagnetic valves through heat tracing pipes, and the electromagnetic valve group controls the sampling of the n high-temperature sampling guns.
Further, the laser detection module comprises a signal generator, a laser driver, 2 lasers (3A and 3B), 2 optical fiber beam splitters (4A and 4B), 2n optical fiber collimators (501A-5 nA and 501B-5 nB), 2n gas absorption tanks (601A-6 nA and 601B-6 nB) and 2n photodetectors (704A-7 nA and 704B-7 nB); the output end of the signal generator is connected with the input end of the laser driver, and the output end of the laser driver is connected with the input ends of the two lasers (3A and 3B); the output ends of the two lasers (3A, 3B) are respectively connected with the input ends of the 2 optical fiber beam splitters (4A, 4B) correspondingly; the emergent laser of each laser is divided into n beams by each optical fiber beam splitter, the n beams are collimated by the corresponding n optical fiber collimators and then respectively enter the corresponding n gas absorption tanks, and the absorption optical signals are converted into electric signals by the corresponding n photoelectric detectors.
Further, the data processing module comprises a multichannel lock-in amplifier, a data acquisition card and an upper computer; the input end of the multichannel lock-in amplifier is connected with each photoelectric detector, the output end of the multichannel lock-in amplifier is connected with the input end of the data acquisition card, and the output end of the data acquisition card is connected with the upper computer.
Furthermore, the output end of the signal generator is also connected with the input end of the multi-channel lock-in amplifier, and the signal generator provides reference signals for the multi-channel lock-in amplifier.
Furthermore, each side flue corresponds to one laser, and a single laser is utilized to combine with the optical fiber beam splitter to generate n measuring beams with the same energy, and the two side flues generate 2n measuring beams with the same energy.
Furthermore, the whole system pipeline always keeps fresh flue gas flowing, so that the flue gas in the sampling pipeline can reflect the dynamic change of the flue gas in the flue in real time.
Further, n high temperature sampling guns located on the same side flue are arranged in a grid mode.
Further, the two sampling modules (100A, 100B) are replaced by more than three sampling modules, the two flue gas pretreatment modules (200A, 200B) are replaced by more than three flue gas pretreatment modules, and the more than three sampling modules are correspondingly arranged in more than three flues.
Furthermore, the sampling module mainly comprises n high-temperature sampling guns and corresponding electromagnetic valve groups of the high-temperature sampling guns on each side of the flue; the arrangement mode of the high-temperature sampling gun in the flue can be grid type, dislocation type or other arrangement modes; the high-temperature sampling gun is connected with the corresponding electromagnetic valve group through the heat tracing pipe, and the electromagnetic valve group controls the high-temperature sampling gun to sample, so that fresh smoke always flows in the whole system pipeline, and the smoke in the sampling pipeline can reflect the dynamic change of the smoke in the flue in real time.
The detection method of the on-line detection system for the ammonia concentration planar distribution at the outlet of the SCR comprises the following steps: the signal generator generates two paths of signals, one path of reference signal is sent to the reference input end of the lock-in amplifier after frequency multiplication, the other path of modulation signal is input to the laser driver, the current and the temperature of the laser driver are controlled, and according to NH 3 Absorption spectrum such that the frequency of the laser is adjusted to NH 3 At the center frequency of the absorption line, the laser generates incident laser light; the incident laser is averagely divided into light beams with the same energy by the corresponding optical fiber beam splitter, and the split laser is collimated by the corresponding optical fiber collimator and then is incident into the corresponding gas absorption tank; the flue gas in the gas absorption tank absorbs the flue gas, so that the laser intensity is weakened, the transmitted laser is obtained, and NH is generated 3 The gas absorbs the light signal; each photoelectric detector correspondingly detects multiple paths of detected gas NH 3 The optical signal of the concentration information is converted into an electric signal for data processing, and the electric signal is amplified by a built-in pre-amplifying circuit; the multiprocessing phase-locked amplifier respectively carries out harmonic detection on the multipath amplified electric signals and extracts NH from the signals 3 The second harmonic signal under specific frequency multiplication of the reference signal, the uncorrelated noise signal isRemoving effectively; amplifying the obtained second harmonic signal to obtain a final processing result of the phase-locked amplifier; the data acquisition card acquires the final processing result of the lock-in amplifier; the upper computer simultaneously analyzes the acquired multi-path data to reverse NH in each path of flue gas 3 Concentration value of (2) to obtain NH 3 The planar distribution result of the concentration is calculated out simultaneously in the multi-path flue gas of each side flue 3 Average value of concentration.
Compared with the prior art, the invention has the following beneficial effects:
the online detection system for ammonia concentration plane distribution adopts TDLAS (Tunable Diode Laser Absorption Spectroscopy) technology, and can accurately measure NH at the outlet of an SCR denitration system 3 Concentration plane distribution. The detection signals of all paths of flue gas can occur simultaneously, the data acquisition and processing are sequentially carried out according to the set sequence, the time interval between the acquisition and processing of two adjacent paths of data is not more than 5s, the grid detection period (about 1.5 min) is greatly shortened, and the equipment cost and the maintenance cost are obviously reduced.
Drawings
Fig. 1 is a schematic structural diagram of an online detection system for ammonia concentration planar distribution at an SCR outlet according to an embodiment.
Fig. 2 is a block diagram of a laser detection module and a data processing module in an example.
Fig. 3 is a schematic diagram of a grid-type sampling point arrangement of a two-sided flue (A, B) in an example.
Detailed Description
The invention will be further described with reference to the accompanying drawings and examples, but the invention is not limited thereto, and it should be noted that the invention will be understood or practiced by those skilled in the art with reference to the prior art unless otherwise specified.
An SCR outlet ammonia concentration plane distribution on-line detection system of this example, as shown in fig. 1, includes a flue (A, B), two sampling modules (100A, 100B), two flue gas pretreatment modules (200A, 200B), a laser detection module 300, a data processing and display module 400, an electric tracing pipe 001, a signal line 002, an optical fiber 003, an exhaust pipe 004, two lasers (3A, 3B), and a gas absorption tank (601A/602A/603A …/6nA/601B/602B/603B …/6 nB).
In this example, the first sampling module 100A, the first flue gas pretreatment module 200A are arranged corresponding to the first flue a; similarly, the second sampling module 100B and the second flue gas pretreatment module 200B are arranged corresponding to the second flue B; the two sampling modules (100A, 100B), the two flue gas pretreatment modules (200A, 200B) and the gas absorption tank are sequentially connected through a heat tracing pipe; the laser detection module is connected with the data processing and displaying module.
FIG. 2 is a block diagram of a laser detection module and a data processing module in an example, including a signal generator 1, a laser driver 2, a first laser 3A, a second laser 3B, a first laser beam splitter 4A, a second laser beam splitter 4B, a fiber collimator (501A/502A/…/5nA/501B/502B/…/5 nB), a gas absorption cell (601A/602A/…/6nA/601B/602B/…/6 nB), a photodetector (701A/702A/…/7nA/701B/702B/…/7 nB), a lock-in amplifier 8, a data acquisition card 9, and a host computer 10.
The laser detection module comprises signal generation (3A, 3B), 2 optical fiber beam splitters (4A, 4B), 2n optical fiber collimators (501A, 502A, … … nA, 501B, 502B, … … nB), 2n gas absorption tanks (601A, 602A, … … 6nA, 601B, 602B, … … nB) and 2n photodetectors (701A, 702A, … … 7nA, 701B, 702B, … … 7 nB); the flues on two sides are respectively corresponding to a laser and an optical fiber beam splitter; the output end of the signal generator 1 is connected with the input end of the laser driver 2, and the output end of the laser driver 2 is connected with the input ends of the lasers (3A and 3B); the output end of the first laser 3A is connected with the input end of the first optical fiber beam splitter 4A, the first optical fiber beam splitter 4A equally divides the emergent laser of the first laser 3A into n beams, the n beams are respectively incident into corresponding gas absorption tanks (601A, 602A and … … 6 nA) after being collimated by optical fiber collimators (501A, 502A and … … nA), and the absorbed optical signals are converted into electric signals by corresponding photoelectric detectors (701A, 702A and … … nA); the output end of the second laser 3B is connected with the input end of the second optical fiber beam splitter 4B, the second optical fiber beam splitter 4B equally divides the emergent laser of the second laser 3B into n beams, the n beams are respectively incident into corresponding gas absorption tanks (601B, 602B and … … < 6 > nB) after being collimated by optical fiber collimators (501B, 502B and … … nB), and the absorbed optical signals are converted into electric signals by corresponding photoelectric detectors (701B, 702B and … … nB).
The data processing module comprises a multichannel lock-in amplifier 8, a data acquisition card 9 and an upper computer 10; the input end of the multichannel lock-in amplifier 8 is connected with each photoelectric detector (701A, 702A, … … nA, 701B, 702B and … … 7 nB), the output end of the multichannel lock-in amplifier 8 is connected with the input end of the data acquisition card 9, and the output end of the data acquisition card 9 is connected with the upper computer 10. The output end of the signal generator 1 is also connected with the input end of the multichannel lock-in amplifier 8, and the signal generator 1 provides a reference signal for the multichannel lock-in amplifier 8.
In this embodiment, 16 sampling points are respectively arranged in the first flue a and the second flue B of the SCR outlet, and the sampling points adopt a grid-type arrangement scheme, as shown in fig. 3.
The detection steps of the SCR outlet ammonia concentration plane distribution on-line detection system specifically comprise:
under the control of the sampling module, the high-temperature sampling gun arranged on the flues at two sides extracts 32 paths of flue gas from 32 flue sampling points arranged according to a grid method, the collection of each path of flue gas is controlled by an electromagnetic valve group correspondingly arranged on a heat tracing pipe connected with the sampling gun outside the flues, and the collected flue gas is subjected to primary filtration through a filter of the high-temperature sampling gun, and enters a flue gas pretreatment module to carry out measurement pretreatment such as further dust removal and the like through the heat tracing pipe connected with the sampling gun. In addition, the device is also provided with a back blowing device, compressed air is used for carrying out regular back blowing on the sampled high-temperature sampling gun, and floating dust attached to the outer surface of the filter is blown and blown back to the flue.
After the flue gas pretreatment module completes pretreatment (such as dust removal) of the flue gas, the flue gas to be measured meeting the measurement requirement is correspondingly introduced into the gas absorption tank through the heat tracing pipe, and the measured flue gas is discharged through the exhaust pipe to ensure thatThe flow of fresh flue gas is always kept in the whole system pipeline during normal operation, so that the flue gas in the sampling pipeline can reflect the dynamic change of the flue gas in the flue in real time. The whole flue gas pretreatment module is fully integrated in the high-temperature heating box, and the structure is compact, so that NH is prevented from being conveyed by a conveying pipeline 3 And (3) the adsorption and crystallization of ammonium bisulfate ensure the authenticity of the sample.
In the laser detection module corresponding to each side flue, the signal generator, the laser driver and the laser are sequentially connected through signal wires, and the laser, the optical fiber beam splitter and the optical fiber collimator are sequentially connected through optical fibers. The signal generator generates two paths of signals, one path of reference signal is sent to the reference input end of the lock-in amplifier after frequency multiplication, the other path of modulation signal is input to the laser driver, the current and the temperature of the laser driver are controlled, and according to NH 3 Absorption spectrum such that the frequency of the laser is adjusted to NH 3 At the center frequency of the absorption line, the laser produces incident laser light. The incident laser is averagely divided into 16 beams with the same energy by the corresponding optical fiber beam splitter, and the split laser is collimated by the corresponding optical fiber collimator and then is incident into the corresponding gas absorption tank; the flue gas in the gas absorption tank absorbs the flue gas, so that the laser intensity is weakened, the transmitted laser is obtained, and NH is generated 3 The gas absorbs the light signal. Each photoelectric detector correspondingly detects 32 paths of NH containing detected gas 3 The optical signal of the concentration information is converted into an electrical signal which is convenient for data processing, and is amplified appropriately by a built-in pre-amplifying circuit.
In the data processing and displaying module, the lock-in amplifier, the data acquisition card and the upper computer are sequentially connected through signal wires. The multiprocessing phase-locked amplifier respectively carries out harmonic detection on 32 paths of amplified electric signals and extracts NH from the amplified electric signals 3 The second harmonic signal under specific frequency multiplication of the reference signal effectively removes the uncorrelated noise signals. The obtained second harmonic signal is amplified properly and then is used as the final processing result of the lock-in amplifier. And the data acquisition card acquires the final processing result of the lock-in amplifier. The upper part is provided withThe machine simultaneously analyzes the 32 paths of data acquired and converts NH in each path of flue gas 3 Concentration value of (2) to obtain NH 3 The planar distribution result of the concentration is calculated out simultaneously, and NH in 16 paths of flue gas of each side 3 The average value of the concentration is transmitted to the DCS system in real time.
The data acquisition and processing time interval of two adjacent paths of gas is not more than 5s, and 32 paths of gas detection can be finished within about 1.5 min.
The invention is not limited to 32 smoke sampling points, and can be used for detecting multiple paths of smoke at the same time.
The above implementations are merely illustrative of preferred embodiments of the invention and are not to be construed as limiting the scope of the invention. It should be noted that numerous variations and modifications could be made to the person skilled in the art without departing from the spirit of the invention, which would fall within the scope of the invention. Accordingly, the scope of the invention should be assessed as that of the appended claims.
Claims (8)
1. The online detection system for the ammonia concentration plane distribution at the outlet of the SCR is characterized by comprising two sampling modules (100A, 100B), two flue gas pretreatment modules (200A, 200B), a laser detection module (300) and a data processing and display module (400); the two sampling modules (100A, 100B) and the two flue gas pretreatment modules (200A, 200B) are respectively corresponding to the flues (A, B) arranged at the two sides; the sampling module, the flue gas pretreatment module and the laser detection module (300) which are positioned on each side flue are sequentially connected through a heat tracing pipe, and the laser detection module is connected with the data processing and display module; the flue gas pretreatment module is used for pretreating the flue gas to enable the flue gas to meet the measurement requirements; the laser detection module enables the frequency of the laser to be adjusted to the central frequency of the NH3 absorption spectrum line, and the laser generates incident laser; the incident laser is split, and the split laser is collimated by an optical fiber collimator and then is incident into a gas absorption tank; the flue gas in the gas absorption tank absorbs the flue gas to generate NH3 gas absorption optical signals, the optical signals which are correspondingly detected to obtain multiple paths of optical signals containing the NH3 concentration information of the detected gas are converted into electrical signals for data processing through each photoelectric detector in the laser detection module, and the electrical signals are amplified through the built-in pre-amplifying circuit; then, reversing the concentration value of NH3 in each path of flue gas through an upper computer to obtain a planar distribution result of NH3 concentration, and calculating an average value of NH3 concentration in each side flue; the data processing and displaying module comprises a multichannel lock-in amplifier (8), a data acquisition card (9) and an upper computer (10); each sampling module comprises n high-temperature sampling guns positioned on the flue at the corresponding side and an electromagnetic valve group corresponding to the high-temperature sampling guns; the high-temperature sampling guns are connected with corresponding electromagnetic valves through heat tracing pipes, and the electromagnetic valve group controls n high-temperature sampling guns to sample; the laser detection module comprises a signal generator (1), a laser driver (2), 2 lasers (3A and 3B), 2 optical fiber beam splitters (4A and 4B), 2n optical fiber collimators (501A-5 nA and 501B-5 nB), 2n gas absorption tanks (601A-6 nA and 601B-6 nB) and 2n photoelectric detectors (704A-7 nA and 704B-7 nB); the output end of the signal generator (1) is connected with the input end of the laser driver (2), and the output end of the laser driver (2) is connected with the input ends of the two lasers (3A and 3B); the output ends of the two lasers (3A, 3B) are respectively connected with the input ends of the 2 optical fiber beam splitters (4A, 4B) correspondingly; the emergent laser of each laser is divided into n beams by each optical fiber beam splitter, the n beams are collimated by the corresponding n optical fiber collimators and then respectively enter the corresponding n gas absorption tanks, and the absorption optical signals are converted into electric signals by the corresponding n photoelectric detectors.
2. The on-line detection system for the concentration plane distribution of the ammonia gas at the outlet of the SCR as claimed in claim 1, wherein the input end of the multichannel lock-in amplifier (8) is connected with each photoelectric detector, the output end of the multichannel lock-in amplifier (8) is connected with the input end of the data acquisition card (9), and the output end of the data acquisition card (9) is connected with the upper computer (10).
3. The on-line detection system for the concentration plane distribution of the ammonia gas at the outlet of the SCR as claimed in claim 1, wherein the output end of the signal generator (1) is also connected with the input end of the multichannel lock-in amplifier (8), and the signal generator (1) provides a reference signal for the multichannel lock-in amplifier (8).
4. The on-line detection system for the concentration of ammonia gas at the outlet of the SCR as claimed in claim 1, wherein each side flue corresponds to one laser, a single laser is used to combine with an optical fiber beam splitter to generate n measuring beams with the same energy, and the two side flues generate 2n measuring beams with the same energy.
5. The online detection system for the concentration plane distribution of the ammonia gas at the outlet of the SCR as claimed in claim 1, wherein the flow of fresh flue gas is always kept in the pipeline of the whole system, so that the flue gas in the sampling pipeline can reflect the dynamic change of the flue gas in the flue in real time.
6. An SCR outlet ammonia gas concentration flat distribution on-line detection system according to claim 1, wherein n high temperature sampling guns located in the same side flue are arranged in a grid.
7. An SCR outlet ammonia concentration planar distribution on-line detection system according to claim 1, characterized in that the two sampling modules (100A, 100B) are replaced by more than three sampling modules, the two flue gas pretreatment modules (200A, 200B) are replaced by more than three flue gas pretreatment modules, which are arranged in more than three flues respectively.
8. The detection method using the SCR outlet ammonia concentration planar distribution on-line detection system according to any one of claims 1 to 7, characterized by comprising: the signal generator generates two paths of signals, one path of reference signal is sent to the reference input end of the lock-in amplifier after frequency multiplication, the other path of modulation signal is input to the laser driver, the current and the temperature of the laser driver are controlled, and according to the NH3 absorption spectrum, the frequency of the laser is adjusted to the center frequency of the NH3 absorption spectrum, and the laser generates incident laser; the incident laser is averagely divided into light beams with the same energy by the corresponding optical fiber beam splitter, and the split laser is collimated by the corresponding optical fiber collimator and then is incident into the corresponding gas absorption tank; the flue gas in the gas absorption tank absorbs the flue gas, so that the laser intensity is weakened, transmitted laser is obtained, and NH3 gas absorption optical signals are generated; each photoelectric detector converts the corresponding detected multipath optical signals containing the NH3 concentration information of the detected gas into electric signals for data processing, and the electric signals are amplified by a built-in pre-amplifying circuit; the multichannel lock-in amplifier respectively carries out harmonic detection on the multipath amplified electric signals, extracts second harmonic signals under specific frequency multiplication of NH3 reference signals, and effectively removes uncorrelated noise signals; amplifying the obtained second harmonic signal to obtain a final processing result of the phase-locked amplifier; the data acquisition card acquires the final processing result of the lock-in amplifier; the upper computer simultaneously analyzes the acquired multi-path data, and the concentration value of NH3 in each path of flue gas is inverted to obtain a planar distribution result of NH3 concentration, and meanwhile, the average value of NH3 concentration in multi-path flue gas of each side of flue is calculated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810450936.2A CN108896510B (en) | 2018-05-11 | 2018-05-11 | SCR outlet ammonia concentration plane distribution online detection system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810450936.2A CN108896510B (en) | 2018-05-11 | 2018-05-11 | SCR outlet ammonia concentration plane distribution online detection system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108896510A CN108896510A (en) | 2018-11-27 |
| CN108896510B true CN108896510B (en) | 2023-10-13 |
Family
ID=64342836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810450936.2A Active CN108896510B (en) | 2018-05-11 | 2018-05-11 | SCR outlet ammonia concentration plane distribution online detection system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108896510B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110907105A (en) * | 2019-12-27 | 2020-03-24 | 杭州梅格森测控技术有限公司 | TDLAS-based flue economizer leakage detection device and detection method |
| CN111359411B (en) * | 2020-03-26 | 2022-05-06 | 华润电力技术研究院有限公司 | Thermal power generating unit and NH-based thermal power generating unit3Measured denitration control method and system |
| CN112394014A (en) * | 2020-11-02 | 2021-02-23 | 河北地质大学 | Real-time monitoring device and method for ammonia escape concentration of flue gas |
| CN114002176A (en) * | 2021-12-06 | 2022-02-01 | 国网江苏省电力有限公司检修分公司 | SF6 decomposition component gas detection device based on ultraviolet absorption spectrum |
| CN114562685A (en) * | 2022-03-16 | 2022-05-31 | 浙江浙能绍兴滨海热电有限责任公司 | TDLAS extraction type tubular smoke cooler leakage monitoring system and method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6064488A (en) * | 1997-06-06 | 2000-05-16 | Monitor Labs, Inc. | Method and apparatus for in situ gas concentration measurement |
| CN104215606A (en) * | 2014-09-18 | 2014-12-17 | 清华大学 | Wavelength modulation spectrum technology-based denitrified ammonia escape rate measurement device and method |
| CN104568834A (en) * | 2015-01-08 | 2015-04-29 | 天津大学 | TDLAS-based ammonia gas detection experiment system |
| CN106442403A (en) * | 2016-09-07 | 2017-02-22 | 天津大学 | Spectrum detection system for diesel SCR ammonia pollution |
| CN206161524U (en) * | 2016-09-07 | 2017-05-10 | 天津大学 | TDLAS gas concentration detection system |
| CN206470247U (en) * | 2017-01-19 | 2017-09-05 | 国电科学技术研究院 | A kind of SCR exhaust pass cross section nitrogen oxides and oxygen concentration on-line monitoring system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100512752C (en) * | 2007-01-12 | 2009-07-15 | 天津市先石光学技术有限公司 | Optical distance optional type atraumatic human body component measuring method and apparatus therefor |
| CN208297343U (en) * | 2018-05-11 | 2018-12-28 | 华南理工大学 | A kind of outlet SCR ammonia concentration plane distribution on-line detecting system |
-
2018
- 2018-05-11 CN CN201810450936.2A patent/CN108896510B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6064488A (en) * | 1997-06-06 | 2000-05-16 | Monitor Labs, Inc. | Method and apparatus for in situ gas concentration measurement |
| CN104215606A (en) * | 2014-09-18 | 2014-12-17 | 清华大学 | Wavelength modulation spectrum technology-based denitrified ammonia escape rate measurement device and method |
| CN104568834A (en) * | 2015-01-08 | 2015-04-29 | 天津大学 | TDLAS-based ammonia gas detection experiment system |
| CN106442403A (en) * | 2016-09-07 | 2017-02-22 | 天津大学 | Spectrum detection system for diesel SCR ammonia pollution |
| CN206161524U (en) * | 2016-09-07 | 2017-05-10 | 天津大学 | TDLAS gas concentration detection system |
| CN206470247U (en) * | 2017-01-19 | 2017-09-05 | 国电科学技术研究院 | A kind of SCR exhaust pass cross section nitrogen oxides and oxygen concentration on-line monitoring system |
Non-Patent Citations (1)
| Title |
|---|
| 激光微量氨分析系统在脱硝逃逸氨检测中的应用;郑利武;赵国成;俞大海;任焱;邱梦春;顾海涛;;电力科技与环保(第05期);第60-62页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108896510A (en) | 2018-11-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108896510B (en) | SCR outlet ammonia concentration plane distribution online detection system and method | |
| CN107243257B (en) | It is suitble to the intelligence spray ammonia control system of full load | |
| US7846405B2 (en) | Method and apparatus for measuring and controlling selective catalytic reduction (SCR) emission control systems | |
| CN105352914B (en) | A kind of gas concentration detection system and its method based on dual wavelength light fibre annular-type cavity | |
| CN206027413U (en) | W of thermal power plant type boiler SNCR deNOx systems | |
| CN208297343U (en) | A kind of outlet SCR ammonia concentration plane distribution on-line detecting system | |
| CN107764774B (en) | Device and method for simultaneously measuring nitric oxide and ammonia in flue gas denitration | |
| CN111459109A (en) | SNCR (selective non-catalytic reduction) denitration control system and control method for industrial boiler | |
| CN103499671A (en) | Method for testing activity of denitration catalyst of selective catalytic reduction (SCR) system of thermal power plant on site | |
| CN103760136A (en) | Online monitoring system of greenhouse gas and stable isotope thereof | |
| CN105975789A (en) | Ammonia-escaping-rate online obtaining method for desulfurization and denitrification control | |
| CN206132125U (en) | Flue total cross -section nitrogen oxide on line measurement system for SCR denitrification process | |
| CN104880536A (en) | Multi-point-location nitrogen oxide continuous monitoring device and continuous monitoring method for SCR reactors | |
| CN105004688B (en) | A kind of thermal power station's waste gas monitoring system | |
| CN211785102U (en) | Flue gas denitrating ammonia escape measurement and analysis device based on multi-point sampling | |
| CN103335970A (en) | Flue gas denitration monitoring system and method | |
| CN110823833B (en) | Mixed sampling type online monitoring device and method for CO concentration in flue gas | |
| CN210071641U (en) | In-situ on-line measurement optical assembly, device and system for high-concentration gas in high-temperature high-pressure pipeline | |
| CN111855603A (en) | Fourier transform ultraviolet ammonia escape on-line monitoring system | |
| CN215599002U (en) | Sulfur trioxide gas on-line measuring equipment | |
| CN208109692U (en) | A kind of multicomponent local laser gas analysis system and analyzer | |
| CN204389392U (en) | A kind of gas-detecting device | |
| CN207020065U (en) | A kind of coal steam-electric plant smoke escape ammonia on-Line Monitor Device | |
| CN112525842B (en) | Real-time detection device for ammonia gas concentration distribution in automobile exhaust based on flat-top laser beam | |
| CN103884821B (en) | A kind of thermal power plant generating tail gas nitrogen oxide component measurement mechanism and measuring method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |