A multi-data mode SCR reaction chamber flue gas concentration online detection system and control method thereof

Abstract

The present invention provides a multi-data mode SCR reaction chamber flue gas concentration online detection system and a control method thereof, comprising a sampling module, a patrol detection module, a spare detection module, a plurality of four-way pipes (170) and a logic control cabinet (150); during normal operation, the patrol detection module performs patrol detection on the flue gas concentration of a single measuring point on one side of the SCR reaction chamber, and the spare detection module detects the average flue gas concentration on the other side of the SCR reaction chamber, and it only takes 60 seconds to complete the detection of a flue gas measuring point; when the patrol detection module fails, the spare detection module replaces the patrol detection module to perform the single-point flue gas concentration patrol detection function, which can not only improve the reliability of system operation and equipment utilization, but also quickly obtain a variety of data related to the flue gas concentration of the SCR reaction chamber, and ensure that the flue gas concentration on both sides of the SCR reaction chamber is always under monitoring, providing more data support for optimizing boiler operation.

Description

Technical Field

[0001] The present invention relates to a SCR reaction chamber smoke concentration detection technology in the field of environmental protection technology, and in particular to a multi-data mode SCR reaction chamber smoke concentration online detection system and a control method thereof. Background Art

[0002] China's Ministry of Environmental Protection requires strict monitoring of various indicators of air pollutants in flue gas from thermal power plants. GB13223-2011 "Emission Standards for Air Pollutants from Thermal Power Plants" puts forward more stringent requirements on the concentrations of nitrogen oxides, sulfur dioxide, etc. in flue gas emitted by thermal power plants. At present, most thermal power plants use selective catalytic reduction (SCR) for denitrification. The amount of ammonia sprayed in the SCR denitrification system has an important influence on the denitrification efficiency. If the amount of ammonia sprayed is too little, the denitrification efficiency will be low, resulting in excessively high NOx concentrations in the flue gas, which may exceed the emission standard limit. If the amount of ammonia sprayed is too large, the excess ammonia will react with SO in the flue gas. 3 , water generates highly viscous ammonium bisulfate, which causes the air preheater flue to be blocked. Therefore, the detection of flue gas concentration in the SCR reaction chamber of a thermal power plant is not only related to the safe operation of the thermal power plant, but also to whether the operation of the thermal power plant complies with the requirements of relevant environmental protection laws and regulations. Since the coal-fired boilers in thermal power plants have the characteristics of diverse coal sources and can adapt to load changes at any time, it is necessary to quickly obtain a variety of data on SCR flue gas concentrations to provide more data support for optimizing boiler operation. However, the data provided by existing online detection systems for boiler flue gas concentrations are relatively single. Patent CN201510811337.5 discloses a boiler flue gas composition patrol detection system and control method, in which the detection method is that a suction pump continuously extracts flue gas from all sampling points for circulation, and detects the flue gas at any sampling point and leads the flue gas at that point to the flue gas analyzer. This detection method not only consumes a lot of energy in the suction pump, but also can only obtain single data on the flue gas concentration of a single measuring point. Patent CN201710038770.9 discloses an online detection method and system for nitrogen oxide and oxygen concentrations in the cross-section of the SCR outlet flue. The detection method is to sample and detect the flue gas at one flue gas sampling point, and extract and discharge the flue gas at another flue gas sampling point for testing. This detection system can only provide flue gas concentration data at a single measuring point, and the system has no backup equipment, so the system reliability is low.

[0003] Invention patent CN201320254786.0 discloses a flue gas distribution measuring device for an SCR flue gas denitration system, which mainly includes a plurality of sampling tubes, a first valve assembly box, a second valve assembly box, a suction pump, a switching valve box, a flue gas analyzer, and a control unit. The control unit controls the flue gas analyzer, the switching valve box, the first valve assembly box, and the second valve assembly box, and each time the flue gas of two sampling points of the SCR denitration system is extracted, the flue gas of one sampling point enters the flue gas analyzer for analysis, and the flue gas of the other sampling point bypasses, and after the analysis of the flue gas entering the flue gas analyzer is completed, the flue gas bypassing the flue gas analyzer enters the flue gas analyzer for analysis. This technical solution is a portable field measurement device for flue gas distribution of SCR flue gas denitrification system, which aims to improve work efficiency and measurement accuracy. The control unit controls the switching valve box, the first valve group box and the second valve group box, and the flue gas in multiple sampling tubes enters the flue gas analyzer for analysis in turn, saving the time and manpower and material resources consumed by manual plugging and unplugging of sampling tubes, improving work efficiency, and improving the measurement accuracy by detecting that when the flue gas of one sampling tube is analyzed by the flue gas analyzer, the flue gas of another sampling tube is in a state to be tested. However, this technical solution also has the problem that the boiler flue gas concentration data provided is single, there is no backup equipment, and it cannot be continuously operated for a long time at the thermal power plant site. Summary of the invention

[0004] In order to solve the problem that the data type of obtaining the flue gas concentration of the SCR reactor in the prior art is single and the system operation reliability is low, the present invention provides a multi-data mode SCR reactor flue gas concentration online detection system and a control method thereof. By setting up a backup detection system, the single-point flue gas concentration on one side of the SCR reactor can be patrolled and the average flue gas concentration on the other side of the SCR reactor can be detected at the same time, thereby increasing the reliability of the system operation and improving the utilization rate of the equipment.

[0005] The technical solution adopted by the present invention is: a multi-data mode SCR reaction chamber flue gas concentration online detection system, comprising a sampling module, a patrol detection module, a spare detection module, a plurality of four-way pipes (170) and a logic control cabinet (150), wherein the logic control cabinet (150) is used to control the sampling module, the patrol detection module and the spare detection module; the sampling module comprises a plurality of sampling guns (100) and a plurality of sampling boxes (110), wherein the outlet of each sampling gun (100) is connected to the corresponding sampling box (110) ) inlet; the patrol detection modules each comprise a plurality of patrol detection connecting pipes (190), a plurality of patrol detection solenoid valves [1B, 2B, 3B, ..., (n)B, (n+1)B, (n+2)B, (n+3)B, ..., (2n)B], a patrol detection mother pipe (220), a patrol detection pump (120-2) and a first flue gas analyzer; the standby detection module comprises a plurality of standby detection connecting pipes (200), a plurality of standby detection solenoid valves [1C, 2C, 3C, ..., (n)C, (n+ 1)C, (n+2)C, (n+3)C, ..., (2n)C], a spare detection mother pipe (230), a spare detection pump (120-3) and a second flue gas analyzer; the outlet of each sampling box (110) is connected to the inlet of the corresponding patrol detection connecting pipe (190) and the inlet of the corresponding spare detection connecting pipe (200) through a four-way pipe (170); the outlets of the patrol detection connecting pipes (190) are all connected to the patrol detection mother pipe (220), and the patrol detection solenoid valve The spare detection solenoid valves are arranged on the patrol detection connecting pipe (190), and the patrol detection main pipe (220) is provided with a patrol detection pump (120-2) and a first flue gas analyzer (140-1); the outlets of the spare detection connecting pipes (200) are connected to the spare detection main pipe (230), and the spare detection solenoid valves are arranged on the spare detection connecting pipe (200), and the spare detection pump (120-3) and the second flue gas analyzer (140-2) are arranged on the spare detection main pipe (230).

[0006] The sampling gun 100 is fixed on the sampling hole of the flue wall of the SCR reaction chamber, with its inlet end extending into the flue and its outlet end connected to the sampling box for extracting flue gas from the flue gas measuring point.

[0007] When the multi-data mode SCR flue gas concentration online detection system is working normally, the patrol detection module performs patrol detection on the single-point flue gas concentration on one side of the SCR reaction chamber, while the standby detection module detects the average flue gas concentration on the other side of the SCR reaction chamber, so that it can provide multiple data of the flue gas concentration in the SCR reaction chamber and ensure that the flue gas concentration on both sides of the SCR reaction chamber is always under monitoring. When the patrol detection module fails, the standby detection module performs the function of the patrol detection module, and the time to complete the flue gas concentration detection of one measuring point is only 60s.

[0008] Preferably, the multi-data mode SCR reaction chamber flue gas concentration online detection system also includes an emptying module, which includes a plurality of emptying connecting pipes (180), a plurality of emptying solenoid valves [1A, 2A, 3A, ..., (n)A, (n+1)A, (n+2)A, (n+3)A, ..., (2n)A], an emptying main pipe (210) and an emptying pump (120-1); the inlets of the emptying connecting pipes (180) are all connected to the corresponding four-way pipes (170), and the outlets of the emptying connecting pipes (180) are all connected to the emptying main pipe (210), an emptying solenoid valve is provided on each of the emptying connecting pipes (180), and an emptying pump (120-1) is provided on the emptying main pipe (210). The purpose of the emptying module is to first allow the flue gas to be tested that will enter the flue gas analyzer at the next moment to flow, so that the flue gas entering the first flue gas analyzer can better reflect the real-time state of the flue gas in the flue.

[0009] Preferably, the multi-data mode SCR reaction chamber flue gas concentration online detection system further comprises a purge module, the purge module comprises a compressed air tank (160), a compressed air solenoid valve and a plurality of compressed air pipelines (240), the compressed air pipeline (240) comprises an inlet and a plurality of outlets, the inlet of the compressed air pipeline (240) is connected to the compressed air tank (160), and the outlet of each compressed air pipeline (240) is connected to the outlet of the corresponding sampling box (110). When the purge module is working normally, the compressed air solenoid valve is opened, and the compressed air in the compressed air tank enters the sampling box and the sampling gun, thereby purging the sampling gun to prevent the sampling gun from being blocked.

[0010] Preferably, the patrol detection module further comprises a first flue gas pretreatment unit (130-1), which is arranged on the patrol detection main pipe (220) and before the first flue gas analyzer (140-1). The first flue gas pretreatment unit is used to perform dehumidification and dust removal pretreatment on the flue gas that is about to enter the first flue gas analyzer.

[0011] Preferably, the standby detection module further comprises a second flue gas pretreatment unit (130-2), the second flue gas pretreatment unit (130-2) being arranged on the standby detection main tube (230) and arranged before the second flue gas analyzer (140-2). The second flue gas pretreatment unit is used for performing dehumidification and dust removal pretreatment on the flue gas that is about to enter the second flue gas analyzer.

[0012] Preferably, the lengths of the plurality of sampling guns (100) are not completely equal, and the sampling guns are arranged along the depth direction of the flue, so that the multi-data mode SCR reaction chamber flue gas concentration online detection system can implement grid method measurement.

[0013] The present invention also discloses an online detection method for flue gas concentration in an SCR reaction chamber, comprising the following steps:

[0014] Step 1. Under the control of the logic control cabinet (150), the patrol detection solenoid valve 1B is opened, the exhaust solenoid valve 2A is opened, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C,…, (2n)C, (n+1)C, (n+2)C, (n+3)C,…, (2n)C] are opened, and the other solenoid valves remain closed. The flue gas extracted from measuring point 1 enters the first flue gas analyzer 140-1 for detection, and the flue gas extracted from measuring point 2 is the flue gas to be tested and is directly connected to the atmosphere. The flue gas extracted from measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / … / measuring point (2n) is mixed in the standby detection mother pipe 230 and then enters the second flue gas analyzer (140-2) for analysis;

[0015] Step 2. After completing the detection of measuring point 1, under the control of the logic control cabinet 150, the patrol detection solenoid valve 1B is closed, the patrol detection solenoid valve 2B is opened, the exhaust solenoid valve 2A is closed, the exhaust solenoid valve 3A is opened, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 2 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 3 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / ... / measuring point (2n) is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis.

[0016] Step 3. After the detection of measuring point 2 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve 2B is closed, the patrol detection solenoid valve 3B is opened, the exhaust solenoid valve 3A is closed, the exhaust solenoid valve 4A is opened, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 3 enters the flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 4 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / ... / measuring point (2n) is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis.

[0017] Step 4. By analogy, after the detection of measuring point n-1 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve (n-1)B is closed, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] remain open, the patrol detection solenoid valve (n)B is opened, the drain solenoid valve (n)A is closed, the drain solenoid valve (n+1)A is opened, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point n enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point (n+1) comes from the other side of the SCR reaction chamber and is the flue gas to be tested, which is directly discharged into the atmosphere, and the flue gas extracted from measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / … / measuring point (2n) is mixed in the spare detection mother tube 230 and enters the second flue gas analyzer (140-2) for analysis.

[0018] Step 5. Complete the detection of measuring point (n), that is, complete the single-point flue gas concentration patrol detection on one side of the SCR reaction chamber, immediately perform the average flue gas concentration detection on this side, and perform patrol detection on the single-point flue gas concentration on the other side. Under the control of the logic control cabinet 150, the patrol detection solenoid valve (n)B is closed, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] are closed, the standby solenoid valves [1C, 2C, 3C, ..., nC] are opened, the patrol detection solenoid valve (n+1)B is opened, the exhaust solenoid valve (n+1)A is closed, and the exhaust solenoid valve (n+2)A is opened. The flue gas extracted from the measuring point (n+1) enters the first flue gas analyzer 140-1 for analysis. The flue gas extracted from the measuring point (n+2) is the flue gas to be tested and is directly connected to the atmosphere. The flue gas extracted from measuring point 1 / measuring point 2 / measuring point 3 / … / measuring point (n) is mixed in the spare detection main pipe (230) and then enters the second flue gas analyzer (140-2) for analysis.

[0019] Step 6. After the detection of the measuring point (n+1) is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve (n+1) B is closed, the patrol detection solenoid valve (n+2) B is opened, the exhaust solenoid valve (n+2) A is closed, the exhaust solenoid valve (n+3) A is opened, the standby detection solenoid valves [1C, 2C, 3C, ..., nC] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from the measuring point (n+2) enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from the measuring point (n+3) is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from the measuring point 1 / measuring point 2 / measuring point 3 / ... / measuring point (n) is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis.

[0020] Step 7. After the detection of the measuring point (n+2) is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve (n+2) B is closed, the patrol detection solenoid valve (n+3) B is opened, the exhaust solenoid valve (n+3) A is closed, the exhaust solenoid valve (n+4) A is opened, the standby detection solenoid valves [1C, 2C, 3C, ..., nC] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from the measuring point (n+3) enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from the measuring point (n+4) is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from the measuring point 1 / measuring point 2 / measuring point 3 / ... / measuring point (n) is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis.

[0021] Step 8. Repeat the process in the same way until the smoke extracted from the measuring point (2n) is tested. At this point, a cycle of single-point smoke concentration patrol test and average concentration test is completed, and the next cycle of test is started according to the above steps 1 to 7.

[0022] When the multi-data mode SCR flue gas concentration online detection system is working normally, the patrol detection module performs patrol detection on the single-point flue gas concentration on one side of the SCR reaction chamber, while the standby detection module detects the average flue gas concentration on the other side of the SCR reaction chamber, so that it can provide multiple data of the flue gas concentration in the SCR reaction chamber and ensure that the flue gas concentration on both sides of the SCR reaction chamber is always under monitoring. When the patrol detection module fails, the standby detection module performs the function of the patrol detection module, and the time to complete the flue gas concentration detection of one measuring point is only 60s.

[0023] The beneficial effects of the present invention are:

[0024] 1. Aiming at the characteristics that thermal power plant equipment needs to operate reliably for a long time, the present invention adds a spare detection module on the basis of the system having a patrol detection module, and coordinates the patrol detection module and the spare detection module. During normal operation, the patrol detection module performs patrol detection on the flue gas concentration of a single measuring point on one side of the SCR reactor, and the spare detection module detects the average flue gas concentration on the other side of the SCR reactor, and it only takes 60 seconds to complete the detection of a flue gas measuring point. When the patrol detection module fails, the spare detection module replaces the patrol detection module to perform the single-point flue gas concentration patrol detection function. This not only improves the reliability of system operation and equipment utilization, but also quickly obtains a variety of data on the flue gas concentration of the SCR reactor, and ensures that the flue gas concentration on both sides of the SCR reactor is always under monitoring, providing more data support for optimizing boiler operation.

[0025] 2. By setting up an emptying module, the flue gas to be tested that enters the flue gas analyzer at the next moment can flow, so that the flue gas entering the first flue gas analyzer can better reflect the real-time state of the flue gas in the flue.

[0026] 3. By setting up a purge module, the compressed air in the compressed air tank enters the sampling box and the sampling gun, thereby purging the sampling gun to prevent the sampling gun from being blocked, and a heating coil is provided in the sampling box, and the heating coil is used to heat the sampled flue gas in the sampling box to prevent water vapor in the flue gas from condensing in the sampling box; the first flue gas pretreatment unit and the second flue gas pretreatment unit are respectively provided on the patrol detection mother pipe and the spare detection mother pipe, and the first flue gas pretreatment unit and the second flue gas pretreatment unit are used for dehumidification and dust removal pretreatment of the flue gas entering the first flue gas analyzer and the second flue gas analyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a multi-data mode SCR reaction chamber smoke concentration online detection system of the present invention;

[0028] Figure 2 Schematic diagram of a multi-data mode SCR reaction chamber flue gas concentration online detection system in an embodiment of the present invention;

[0029] Figure 3 It is the result of detecting the NO concentration in a certain SCR reaction chamber by the multi-data mode SCR reaction chamber smoke concentration online detection system of the present invention.

[0030] The technical features indicated by the reference numerals in the figures are as follows:

[0031] 100, sampling gun; 110, sampling box; 120-1, emptying pump; 120-2, patrol test pump; 120-3, spare test pump; 130-1, first flue gas pretreatment unit; 130-2, second flue gas pretreatment unit; 140-1, first flue gas analyzer; 140-2, second flue gas analyzer; 150, logic control cabinet; 160, compressed air tank; 170, four-way pipe; 180, emptying connecting pipe; 190, patrol test connecting pipe; 200, spare test connecting pipe; 210, emptying main pipe; 220, patrol test Test main pipe; 230, spare test main pipe; 240, compressed air pipeline; [1A, 2A, 3A, …, (n)A, (n+1)A, (n+2)A, (n+3)A, …, (2n)A], exhaust solenoid valve; [1B, 2B, 3B, …, (n)B, (n+1)B, (n+2)B, (n+3)B, …, (2n)B], patrol test solenoid valve; [1C, 2C, 3C, …, (n)C, (n+1)C, (n+2)C, (n+3)C, …, (2n)C], spare test solenoid valve. DETAILED DESCRIPTION

[0032] like Figure 1 As shown, a multi-data mode SCR reaction chamber flue gas concentration online detection system includes a sampling module, a patrol detection module, a spare detection module, a plurality of four-way pipes 170 and a logic control cabinet 150, wherein the logic control cabinet 150 is used to control the sampling module, the patrol detection module and the spare detection module; the sampling module includes a plurality of sampling guns 100 and a plurality of sampling boxes 110, wherein the outlet of each sampling gun 100 is connected to the inlet of the corresponding sampling box 110, wherein the sampling gun 100 is fixed on the sampling hole of the flue wall of the SCR reaction chamber, wherein the inlet end thereof extends into the flue, and the outlet end thereof is connected to the sampling box 110, and is used to extract the flue gas at the flue gas measuring point, and a plurality of sampling guns 100 of different lengths are arranged along the depth direction of the flue, so as to realize grid method measurement, and a heating coil is installed in the pipe section of the sampling box 100, which is used to heat the sampled flue gas in the pipe section to prevent the water vapor in the flue gas from condensing in the pipe section of the sampling box.

[0033] The patrol detection module includes a plurality of patrol detection connecting pipes 190, a plurality of patrol detection solenoid valves [1B, 2B, 3B, ..., (n) B, (n+1) B, (n+2) B, (n+3) B, ..., (2n) B], a patrol detection mother pipe 220, a patrol detection pump 120-2 and a first flue gas analyzer 140-1, wherein the patrol detection connecting pipe 190 is used to guide the flue gas to the patrol detection mother pipe 220, and the patrol detection solenoid valves are all arranged on the patrol detection connecting pipe 190, and the patrol detection solenoid valves [1B, 2B, 3B, ..., (n) B, (n+1) B, (n+2) B, (n+3) B, ..., (2n) B] are used to control the extraction of patrol detection flue gas. The outlets of the patrol detection connecting pipes 190 are all connected to the patrol detection mother pipe 220. A patrol detection pump 120-2 and a first flue gas analyzer 140-1 are arranged on the patrol detection mother pipe 220. The patrol detection module also includes a first flue gas pretreatment unit 130-1, which is arranged on the patrol detection mother pipe 220 and before the first flue gas analyzer (140-1). The patrol detection pump 120-2 is used to control the flow rate of the extracted test flue gas, and the first flue gas pretreatment unit 130-1 is used to perform dehumidification and dust removal pretreatment on the flue gas that is about to enter the first flue gas analyzer 140-1. The first flue gas analyzer 140-1 is used to detect single-point flue gas and transmit the analysis results to the power plant DCS.

[0034] The standby detection module includes a plurality of standby detection connecting pipes 200, a plurality of standby detection solenoid valves [1C, 2C, 3C, ..., (n)C, (n+1)C, (n+2)C, (n+3)C, ..., (2n)C], a standby detection main pipe 230, a standby detection pump 120-3 and a second flue gas analyzer 140-2; the standby detection solenoid valves are all arranged on the standby detection connecting pipe 200, and the standby detection connecting pipe 200 is used to guide the flue gas to the standby detection main pipe 230; the outlets of the standby detection connecting pipe 200 are all connected to the standby detection main pipe 230, and the standby detection pump 120-3 and the second flue gas analyzer 140-2 are arranged on the standby detection main pipe 230. The standby detection module also includes a second flue gas pretreatment unit 130-2, which is arranged on the standby detection main pipe 230 and before the second flue gas analyzer (140-2). The standby detection pump 120-3 is used to control the flow rate of extracted flue gas, and the second flue gas pretreatment unit 130-2 is used to perform dehumidification and dust removal pretreatment on the flue gas that is about to enter the second flue gas analyzer 140-2. The second flue gas analyzer 140-2 is used to detect the average concentration of mixed flue gas at multiple measuring points and transmit the analysis results to the power plant DCS. Another function of the second flue gas analyzer 140-2 is to perform the single-point flue gas concentration patrol detection function of the first flue gas analyzer 140-1 when the first flue gas analyzer 140-1 fails.

[0035] The multi-data mode SCR reaction chamber flue gas concentration online detection system also includes an emptying module, which includes a plurality of emptying connecting pipes 180, a plurality of emptying solenoid valves [1A, 2A, 3A, ..., (n)A, (n+1)A, (n+2)A, (n+3)A, ..., (2n)A], an emptying main pipe 210 and an emptying pump 120-1; the inlets of the emptying connecting pipes 180 are all connected to the corresponding four-way pipes 170, and the outlets of the emptying connecting pipes 180 are all connected to the emptying main pipe 210, and an emptying solenoid valve is arranged on each of the emptying connecting pipes 180, and an emptying pump 120-1 is arranged on the emptying main pipe 210. The purpose of the emptying module is to first let the flue gas to be tested that enters the flue gas analyzer at the next moment flow, so that the flue gas entering the first flue gas analyzer can better reflect the real-time state of the flue gas in the flue. The exhaust main pipe 210 is used to pass the smoke from the exhaust connecting pipe 180 to the atmosphere, and the exhaust pump 120-1 is used to control the flow rate of the extracted exhaust smoke.

[0036] The multi-data mode SCR reaction chamber flue gas concentration online detection system also includes a purge module, which includes a compressed air tank 160, a compressed air solenoid valve and a plurality of compressed air pipelines 240. The compressed air pipeline 240 includes an inlet and a plurality of outlets. The inlet of the compressed air pipeline 240 is connected to the compressed air tank 160, and each outlet of the compressed air pipeline 240 is connected to the outlet of the corresponding sampling box 110. A compressed air solenoid valve is provided on the pipe section in the sampling box 110 for controlling the purging of the sampling gun 100 by compressed air. The compressed air tank is used to store compressed air of a certain pressure for purging the sampling gun, and the compressed air pipeline 240 is used to connect the compressed air tank and the compressed air solenoid valve in the sampling box 110.

[0037] The outlet of each sampling box 110 , the inlet of the corresponding patrol detection connecting pipe 190 , the inlet of the corresponding standby detection connecting pipe 200 , and the inlet of the corresponding exhaust connecting pipe 180 are connected through the corresponding four-way pipe 170 .

[0038] The present invention also discloses an online detection method for the flue gas concentration in an SCR reaction chamber. The present invention takes n=5 as an example to illustrate the steps of an online detection method for the flue gas concentration in an SCR reaction chamber. Figure 2 As shown,

[0039] Step 1. Under the control of the logic control cabinet 150, the patrol detection solenoid valve 1B is opened, the exhaust solenoid valve 2A is opened, the standby detection solenoid valves [6C, 7C, 8C, 9C, 10C] are opened, and the other solenoid valves remain closed. The flue gas extracted from measuring point 1 enters the first flue gas analyzer 140-1 for detection, and the flue gas extracted from measuring point 2 is the flue gas to be tested, which is directly connected to the atmosphere. The purpose is to make the test flue gas flow at the next moment, so that the flue gas entering the first flue gas analyzer can better reflect the real-time state of the flue gas in the flue. The flue gas extracted from measuring point 6 / measuring point 7 / measuring point 8 / measuring point 9 / measuring point 10 is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis; its purpose is to detect the average concentration of the flue gas on the B side of the SCR reaction chamber where measuring point 6 / measuring point 7 / measuring point 8 / measuring point 9 / measuring point 10 is located.

[0040] Step 2. After completing the detection of measuring point 1, under the control of the logic control cabinet 150, the patrol detection solenoid valve 1B is closed, the patrol detection solenoid valve 2B is opened, the exhaust solenoid valve 2A is closed, the exhaust solenoid valve 3A is opened, the standby detection solenoid valves [6C, 7C, 8C, 9C, 10C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 2 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 3 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 6 / measuring point 7 / measuring point 8 / measuring point 9 / measuring point 10 is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis.

[0041] Step 3. After completing the detection of measuring point 2, under the control of the logic control cabinet 150, the patrol detection solenoid valve 2B is closed, the patrol detection solenoid valve 3B is opened, the exhaust solenoid valve 3A is closed, the exhaust solenoid valve 4A is opened, the standby detection solenoid valves [6C, 7C, 8C, 9C, 10C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 3 enters the flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 4 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 6 / measuring point 7 / measuring point 8 / measuring point 9 / measuring point 10 is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis.

[0042] Step 4. After completing the detection of measuring point 3, under the control of the logic control cabinet 150, the patrol detection solenoid valve 3B is closed, the patrol detection solenoid valve 4B is opened, the exhaust solenoid valve 4A is closed, the exhaust solenoid valve 5A is opened, the standby detection solenoid valves [6C, 7C, 8C, 9C, 10C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 4 enters the flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 5 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 6 / measuring point 7 / measuring point 8 / measuring point 9 / measuring point 10 is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis.

[0043] Step 5. After the detection of measuring point 4 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve 4B is closed, the patrol detection solenoid valve 5B is opened, the exhaust solenoid valve 5A is closed, the exhaust solenoid valve 6A is opened, the standby detection solenoid valves [6C, 7C, 8C, 9C, 10C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 5 enters the flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 6 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 6 / measuring point 7 / measuring point 8 / measuring point 9 / measuring point 10 is mixed in the standby detection mother pipe 230 and enters the second flue gas analyzer (140-2) for analysis.

[0044] Step 6. After the detection of measuring point 5 is completed, the single-point flue gas concentration patrol detection on one side of the SCR reaction chamber is completed, and the average flue gas concentration detection is immediately performed on this side, and the single-point flue gas concentration on the other side is patrol detected. Under the control of the logic control cabinet 150, the patrol detection solenoid valve 5B is closed, the standby detection solenoid valve [6C, 7C, 8C, 9C, 10C] is closed, the standby solenoid valve [1C, 2C, 3C, 4C, 5C] is opened, the patrol detection solenoid valve 6B is opened, the exhaust solenoid valve 6A is closed, and the exhaust solenoid valve 7A is opened. The flue gas extracted from measuring point 6 enters the first flue gas analyzer 140-1 for analysis. The flue gas extracted from measuring point 7 is the flue gas to be tested and is directly connected to the atmosphere. The flue gas extracted from measuring point 1 / measuring point 2 / measuring point 3 / measuring point 4 / measuring point 5 / measuring point 6 is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis. The purpose is to detect the average concentration of smoke on the A side where measuring points 1 / 2 / 3 / 4 / 5 / 6 are located.

[0045] Step 7. After the detection of measuring point 6 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve 6B is closed, the patrol detection solenoid valve 7B is opened, the exhaust solenoid valve 7A is closed, the exhaust solenoid valve 8A is opened, the standby detection solenoid valves [1C, 2C, 3C, 4C, 5C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 7 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 8 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 1 / measuring point 2 / measuring point 3 / measuring point 4 / measuring point 5 is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis.

[0046] Step 8. After the detection of measuring point 7 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve 7B is closed, the patrol detection solenoid valve 8B is opened, the exhaust solenoid valve 8A is closed, the exhaust solenoid valve 9A is opened, the standby detection solenoid valves [1C, 2C, 3C, 4C, 5C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 8 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 9 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 1 / measuring point 2 / measuring point 3 / measuring point 4 / measuring point 5 is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis.

[0047] Step 9. After the detection of measuring point 8 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve 8B is closed, the patrol detection solenoid valve 9B is opened, the exhaust solenoid valve 9A is closed, the exhaust solenoid valve 10A is opened, the standby detection solenoid valves [1C, 2C, 3C, 4C, 5C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 9 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 10 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 1 / measuring point 2 / measuring point 3 / measuring point 4 / measuring point 5 is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis.

[0048] Step 10. After the detection of measuring point 9 is completed, under the control of the logic control cabinet 150, the patrol detection solenoid valve 9B is closed, the patrol detection solenoid valve 10B is opened, the exhaust solenoid valve 10A is closed, the exhaust solenoid valve 1A is opened, the standby detection solenoid valves [1C, 2C, 3C, 4C, 5C] remain open, and the remaining solenoid valves remain closed. The flue gas extracted from measuring point 10 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 1 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point 1 / measuring point 2 / measuring point 3 / measuring point 4 / measuring point 5 is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis.

[0049] Step 11. At this point, a cycle of single-point smoke concentration patrol detection and average concentration detection is completed, and the next cycle of detection is started according to the above steps 1 to 11.

[0050] The results of the multi-data mode SCR reaction chamber smoke concentration online detection system of the present invention detecting the NO concentration in a certain SCR reaction chamber are as follows: Figure 3 shown.

[0051] The above is a detailed description of an embodiment of a multi-data mode SCR reaction chamber flue gas concentration online detection system and a control method thereof provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A multi-data mode SCR reaction chamber flue gas concentration online detection system, characterized by: The invention comprises a sampling module, a patrol detection module, a spare detection module, a plurality of four-way pipes (170) and a logic control cabinet (150), wherein the logic control cabinet (150) is used to control the sampling module, the patrol detection module and the spare detection module; the sampling module comprises a plurality of sampling guns (100) and a plurality of sampling boxes (110), wherein the outlet of each sampling gun (100) is connected to the inlet of the corresponding sampling box (110); the patrol detection module comprises a plurality of patrol detection connecting pipes (190 ), a plurality of patrol detection solenoid valves [1B, 2B, 3B, ..., (n)B, (n+1)B, (n+2)B, (n+3)B, ..., (2n)B], a patrol detection mother pipe (220), a patrol detection pump (120-2) and a first flue gas analyzer (140-1); the standby detection module comprises a plurality of standby detection connecting pipes (200), a plurality of standby detection solenoid valves [1C, 2C, 3C, ..., (n)C, (n+1)C, (n+2)C, (n+3)C, ..., (2n)C], a spare detection main pipe (230), a spare detection pump (120-3) and a second flue gas analyzer (140-2); the outlet of each sampling box (110) is connected to the inlet of the corresponding patrol detection connecting pipe (190) and the inlet of the corresponding spare detection connecting pipe (200) through a four-way pipe (170); the outlets of the patrol detection connecting pipes (190) are all connected to the patrol detection main pipe (220), and the patrol detection solenoid valves are all arranged in the On the patrol detection connecting pipe (190), a patrol detection pump (120-2) and a first flue gas analyzer (140-1) are arranged on the patrol detection main pipe (220); the outlets of the standby detection connecting pipe (200) are all connected to the standby detection main pipe (230), the standby detection solenoid valves are all arranged on the standby detection connecting pipe (200), and the standby detection pump (120-3) and the second flue gas analyzer (140-2) are arranged on the standby detection main pipe (230).

2. A multi-data mode SCR reaction chamber flue gas concentration online detection system as claimed in claim 1, characterized in that: The multi-data mode SCR reaction chamber flue gas concentration online detection system also includes an emptying module, which includes a plurality of emptying connecting pipes (180), a plurality of emptying solenoid valves [1A, 2A, 3A, ..., (n)A, (n+1)A, (n+2)A, (n+3)A, ..., (2n)A], an emptying main pipe (210) and an emptying pump (120-1); the inlets of the emptying connecting pipes (180) are all connected to the corresponding four-way pipes (170), the outlets of the emptying connecting pipes (180) are all connected to the emptying main pipe (210), an emptying solenoid valve is arranged on each of the emptying connecting pipes (180), and an emptying pump (120-1) is arranged on the emptying main pipe (210).

3. A multi-data mode SCR reaction chamber flue gas concentration online detection system as claimed in claim 2, characterized in that: The multi-data mode SCR reaction chamber flue gas concentration online detection system also includes a purge module, which includes a compressed air tank (160), a compressed air solenoid valve and a plurality of compressed air pipelines (240), wherein the compressed air pipeline (240) includes an inlet and a plurality of outlets, wherein the inlet of the compressed air pipeline (240) is connected to the compressed air tank (160), and the outlet of each compressed air pipeline (240) is connected to the outlet of the corresponding sampling box (110).

4. A multi-data mode SCR reaction chamber flue gas concentration online detection system as claimed in claim 2, characterized in that: The patrol detection module further comprises a first flue gas pretreatment unit (130-1), wherein the first flue gas pretreatment unit (130-1) is arranged on the patrol detection main pipe (220) and before the first flue gas analyzer (140-1).

5. A multi-data mode SCR reaction chamber flue gas concentration online detection system as claimed in claim 2, characterized in that: The standby detection module further comprises a second flue gas pre-processing unit (130-2), wherein the second flue gas pre-processing unit (130-2) is arranged on the standby detection main tube (230) and before the second flue gas analyzer (140-2).

6. A multi-data mode SCR reaction chamber flue gas concentration online detection system as claimed in claim 3, characterized in that: The lengths of the plurality of sampling guns (100) are not completely equal.

7. An SCR reaction chamber flue gas concentration online detection method using the SCR reaction chamber flue gas concentration online detection system according to any one of claims 2 to 6, characterized in that: The steps include: Step 1. Under the control of the logic control cabinet (150), the patrol detection solenoid valve 1B is opened, the exhaust solenoid valve 2A is opened, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C, (n+1)C, (n+2)C, (n+3)C, ..., (2n)C] are opened, and the other solenoid valves remain closed. The flue gas extracted from the measuring point 1 enters the first flue gas analyzer (140-1) for detection, the flue gas extracted from the measuring point 2 is the flue gas to be tested and is directly connected to the atmosphere. The flue gas extracted from the measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / ... / measuring point (2n) is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis; Step 2. After the detection of measuring point 1 is completed, under the control of the logic control cabinet (150), the patrol detection solenoid valve 1B is closed, the patrol detection solenoid valve 2B is opened, the exhaust solenoid valve 2A is closed, the exhaust solenoid valve 3A is opened, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] remain open, and the remaining solenoid valves remain closed; the flue gas extracted from measuring point 2 enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 3 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / ... / measuring point (2n) is mixed in the standby detection mother pipe (230) and then enters the second flue gas analyzer (140-2) for analysis; Step 3. After the detection of measuring point 2 is completed, under the control of the logic control cabinet (150), the patrol detection solenoid valve 2B is closed, the patrol detection solenoid valve 3B is opened, the exhaust solenoid valve 3A is closed, the exhaust solenoid valve 4A is opened, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] remain open, and the other solenoid valves remain closed. The flue gas extracted from measuring point 3 enters the flue gas analyzer (140-1) for analysis, the flue gas extracted from measuring point 4 is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / ... / measuring point (2n) is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis; Step 4. By analogy, after the detection of the measuring point n-1 is completed, under the control of the logic control cabinet (150), the patrol detection solenoid valve (n-1) B is closed, the standby detection solenoid valve (n+1) C / (n+2) C / (n+3C) / … / (2n) C remains open, the patrol detection solenoid valve (n) B is opened, the drain solenoid valve (n) A is closed, the drain solenoid valve (n+1) A is opened, and the remaining solenoid valves are closed. The magnetic valve remains in a closed state, the flue gas extracted from the measuring point n enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from the measuring point (n+1) comes from the other side of the SCR reaction chamber and is the flue gas to be tested, and is directly discharged into the atmosphere, and the flue gas extracted from the measuring point (n+1) / measuring point (n+2) / measuring point (n+3) / … / measuring point (2n) is mixed in the spare detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis; Step 5. After the detection of the measuring point (n) is completed, the single-point flue gas concentration patrol detection on one side of the SCR reaction chamber is completed, and the average flue gas concentration detection on this side is immediately performed, and the single-point flue gas concentration on the other side is patrol detected. Under the control of the logic control cabinet (150), the patrol detection solenoid valve (n)B is closed, the standby detection solenoid valves [(n+1)C, (n+2)C, (n+3)C, ..., (2n)C] are closed, and the standby detection solenoid valves [1C, 2C, 3C, ..., nC] are opened. The patrol detection solenoid valve (n+1) B is opened, the exhaust solenoid valve (n+1) A is closed, and the exhaust solenoid valve (n+2) A is opened. The flue gas extracted from the measuring point (n+1) enters the first flue gas analyzer (140-1) for analysis. The flue gas extracted from the measuring point (n+2) is the flue gas to be tested and is directly connected to the atmosphere. The flue gas extracted from the measuring point 1 / measuring point 2 / measuring point 3 / … / measuring point (n) is mixed in the spare detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis. Step 6. After the detection of the measuring point (n+1) is completed, under the control of the logic control cabinet (150), the patrol detection solenoid valve (n+1) B is closed, the patrol detection solenoid valve (n+2) B is opened, the exhaust solenoid valve (n+2) A is closed, the exhaust solenoid valve (n+3) A is opened, the standby detection solenoid valves [1C, 2C, 3C, ..., nC] remain open, and the other solenoid valves remain closed. The flue gas extracted from the measuring point (n+2) enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from the measuring point (n+3) is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from the measuring point 1 / measuring point 2 / measuring point 3 / ... / measuring point (n) is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis; Step 7. After the detection of the measuring point (n+2) is completed, under the control of the logic control cabinet (150), the patrol detection solenoid valve (n+2) B is closed, the patrol detection solenoid valve (n+3) B is opened, the exhaust solenoid valve (n+3) A is closed, the exhaust solenoid valve (n+4) A is opened, the standby detection solenoid valves [1C, 2C, 3C, ..., nC] remain open, and the other solenoid valves remain closed. The flue gas extracted from the measuring point (n+3) enters the first flue gas analyzer (140-1) for analysis, the flue gas extracted from the measuring point (n+4) is the flue gas to be tested and is directly connected to the atmosphere, and the flue gas extracted from the measuring point 1 / measuring point 2 / measuring point 3 / ... / measuring point (n) is mixed in the standby detection mother pipe (230) and enters the second flue gas analyzer (140-2) for analysis; Step 8. Repeat the process in the same way until the smoke extracted from the measuring point (2n) is tested. At this point, a cycle of single-point smoke concentration patrol test and average concentration test is completed, and the next cycle of test is started according to the above steps 1 to 7.

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