Denitration NOx online partition synchronous measurement system based on dilution method

Abstract

The utility model provides a denitration NOx online partition synchronous measurement system based on a dilution method. The denitration NOx online partition synchronous measurement system based on the dilution method is characterized in that a gas storage tank is installed at an outlet of a drying machine through a pipeline, a pressure gauge is installed on the outer surface of the gas storage tank, and a first pressure regulating valve, a second pressure regulating valve and a third pressure regulating valve are installed at an outlet of the gas storage tank through pipelines; outlets of the first pressure regulating valve, the second pressure regulating valve and the third pressure regulating valve are respectively provided with a second dilution sampler, a first dilution sampler and a third dilution sampler through pipelines. According to the denitration NOx online partition synchronous measurement system based on the dilution method, the accuracy can be best when low concentration is measured through the system, the dilution sampling method and the chemiluminescence method are combined for sampling and measuring, the system has the advantages that water removal is not needed, and the system is simple, the fault outage probability and the maintenance cost are greatly reduced, and the system is suitable for large-scale popularization and application. And the method is particularly suitable for NOx measurement after ultralow emission.

Description

Technical Field

[0001] The utility model relates to the technical field of air ventilation, in particular to an online partition synchronous measurement system for denitrifying NOx based on the dilution method. Background Technique

[0002] At present, the control of nitrogen oxide emissions at the chimney of large domestic supercritical units is relatively strict. "Ultra-low emissions" is the primary task to be completed in the future optimization of the denitrification system, which is to optimize the process partition of the original denitrification system.

[0003] In the current domestic market, the measurement of NOx is based on three principles: chemiluminescence method, non-dispersive infrared method, and ultraviolet differential method. Through technologies such as multi-point synchronous measurement of denitrifying NOx in partitions and feedforward predictive control of the main loop, the ammonia injection amount is accurately controlled in the first stage, and then through further mixing within the partition, the reductant and nitrogen oxides are fully contacted, thereby achieving efficient removal of nitrogen oxides.

[0004] However, traditional chemiluminescence instruments have poor accuracy when measuring low concentrations, and the sampling method is relatively single. They require regular water removal and the system operation is relatively complex, which increases the probability of failure shutdown and maintenance costs.

[0005] Therefore, it is necessary to provide an online partition synchronous measurement system for denitrifying NOx based on the dilution method to solve the above technical problems. Summary of the Invention

[0006] The utility model provides an online partition synchronous measurement system for denitrifying NOx based on the dilution method, which solves the problems that traditional chemiluminescence instruments have poor accuracy when measuring low concentrations, increasing the probability of failure shutdown and maintenance costs.

[0007] To solve the above technical problems, the online partition synchronous measurement system for denitrifying NOx based on the dilution method provided by the utility model includes: a dryer, a moving bottom plate;

[0008] An air inlet pipe, the air inlet pipe is installed at the inlet of the dryer, the outlet of the dryer is installed with a gas storage tank through a pipeline, a pressure gauge is installed on the outer surface of the gas storage tank, the outlet of the gas storage tank is respectively installed with a first pressure regulating valve, a second pressure regulating valve and a third pressure regulating valve through pipelines, the outlets of the first pressure regulating valve, the second pressure regulating valve and the third pressure regulating valve are respectively installed with a second dilution sampler, a first dilution sampler and a third dilution sampler through pipelines, the outlets of the second dilution sampler, the first dilution sampler and the third dilution sampler are respectively installed with a second solenoid valve, a first solenoid valve and a third solenoid valve through pipelines, the outlets of the second solenoid valve, the first solenoid valve and the third solenoid valve are all connected to the inlet of a manifold through pipelines, and the outlet of the manifold is connected to the inlet of a flue gas analyzer through a pipeline;

[0009] The fourth pressure regulating valve, the inlet of the fourth pressure regulating valve is connected to the other outlet of the ball valve through a pipeline, and the outlet of the fourth pressure regulating valve is connected to the inlet of the flue gas analyzer through a pipeline;

[0010] Compressed gas enters the interior of the dryer through the inlet pipe, and then enters the interior of the gas storage tank through the pipeline. The instrument detection limit of the chemiluminescence method is the lowest, and it has the best accuracy when measuring low concentrations. The dilution sampling method combined with the chemiluminescence method for the sampling measurement system has the characteristics of not requiring water removal and a simple system, greatly reducing the probability of failure shutdown and maintenance costs. It is especially suitable for the measurement of NOx after ultra-low emissions and is the preferred measurement method recommended by the US EPA. In this research, a NOx measurement system combining the dilution method and the chemiluminescence method is adopted. The flue gas analyzer selects the 42i analyzer of Thermo Fisher Scientific in the United States. The measurement principle of the NOx analyzer using the chemiluminescence method is that nitric oxide NO reacts with ozone O3 to produce a unique luminescence, and the intensity of this luminescence is linearly proportional to the concentration of NO. When the NO2 molecule excited by electrons decays to a lower energy state, it will emit infrared light. Specifically, NO + O3 → NO2 + O2 + hv. Nitrogen dioxide NO2 must first be converted into NO to use the chemiluminescence reaction for measurement. NO2 is converted into NO through a molybdenum NO2 to NO converter heated to about 325 °C. The ambient air sample is inhaled into the 42i analyzer through the sampling plug. The sample flows through a capillary tube and then flows to the mode solenoid valve. The solenoid valve sends the sample directly to the reaction chamber in the NO mode or through the NO2 to NO converter and then to the reaction chamber in the NOx mode. A flow sensor located before the reaction chamber is used to measure the sample flow. Dry air enters the 42i analyzer through the dry air plug, passes through a flow switch, and then through a silent discharge ozone generator. The ozone generator is used to generate the ozone required for the chemiluminescence reaction. In the reaction chamber, ozone reacts with NO in the sample to produce excited NO2 molecules. The photomultiplier tube PMT encapsulated in the thermoelectric cooler detects the luminescence generated in this reaction. The exhaust gas starts from the reaction chamber, moves to the pump through the ozone O3 converter, and then is discharged through the ventilation hole. The NO and NOx concentrations calculated in the NO and NOx modes are stored in the memory. The concentration difference is used to calculate the concentration of NO2. The 42i analyzer outputs the concentrations of NO, NO2, and NOx to the front panel display and analog output. At the same time, these data can also be obtained through the serial or Ethernet interface. The core components of the constant flow dilution sampling technology are the Venturi and the sonic orifice.

[0011] Preferably, the dryer and the gas storage tank form a zero gas treatment system, and the first pressure regulating valve, the second pressure regulating valve, and the third pressure regulating valve and the first dilution sampler, the second dilution sampler, and the third dilution sampler form a local dilution sampling system.

[0012] Preferably, another outlet of the first dilution sampler, the second dilution sampler and the third dilution sampler is connected to the exhaust air through a pipeline, and the flue gas analyzer, the first solenoid valve, the second solenoid valve and the third solenoid valve form a synchronous wheel measurement system with the manifold.

[0013] Preferably, mounting bolts are installed at the positions of the four corners at the bottom of the moving base plate, and the bottom ends of the mounting bolts are rotatably connected with moving wheels;

[0014] The moving wheels are small universal wheels, which can move the moving base plate at the placed position according to requirements.

[0015] Preferably, a fixed frame is fixedly connected to the top of the moving base plate, and fixed blocks are fixedly connected to the positions on both sides at the top of the fixed frame;

[0016] The fixed frame is installed at the position on the outer surface at the bottom of the moving base plate.

[0017] Preferably, adjusting bolts are threadedly connected to the opposite sides of the two fixed blocks, the other ends of the adjusting bolts are rotatably connected with clamping plates through rotating rings, and contact pads are fixedly connected to the adjacent sides of the two clamping plates;

[0018] The flue gas analyzer is placed on the top of the moving base plate.

[0019] Preferably, the other end of the intake pipe is installed with a delivery pipe through a first flange, and the other end of the delivery pipe is fixedly connected with a housing;

[0020] The housing is conical, specifically referring to Figure 4 , and holes through which the dust collecting pipe can pass are opened at the position of the outer surface of the housing at the bottom.

[0021] Preferably, the other end of the housing is installed with a sealing cover through bolts, one end of the sealing cover is fixedly connected with a filter pipe with filter holes, the other end of the filter pipe is fixedly connected with a baffle plate, a dust collecting pipe is fixedly connected to the outer surface of the filter pipe near the other end and at the bottom, and the other end of the dust collecting pipe is installed with an external threaded pipe with a threaded cap;

[0022] The baffle plate is also provided with filter holes.

[0023] Preferably, the other end of the sealing cover is fixedly connected with a connecting pipe, and the other end of the connecting pipe is fixedly connected with a second flange;

[0024] The connecting pipe and the filter pipe are adjacent in position.

[0025] Compared with the related technologies, the denitration NOx online partition synchronous measurement system and method provided by the utility model based on the dilution method have the following beneficial effects:

[0026] The utility model provides a denitrification NOx online partition synchronous measurement system based on the dilution method. In order to reduce the probability of failure shutdown and maintenance cost of the chemiluminescence instrument during use, first connect the intake pipe and the dryer, and connect the dryer and the gas storage tank through a pipeline. Then connect the outlet of the gas storage tank to the ball valve through a pipeline, and connect the two outlets of the ball valve to the first pressure regulating valve, the second pressure regulating valve, the third pressure regulating valve, and the fourth pressure regulating valve through pipelines respectively. After that, only need to connect the first dilution sampler, the second dilution sampler, and the third dilution sampler to the first pressure regulating valve, the second pressure regulating valve, and the third pressure regulating valve through pipelines respectively. The outlets of the first dilution sampler, the second dilution sampler, and the third dilution sampler are all connected to the first solenoid valve, the second solenoid valve, and the third solenoid valve through pipelines, and connect the first solenoid valve, the second solenoid valve, and the third solenoid valve to the manifold through a pipeline. The outlet of the manifold is connected to the inlet of the flue gas analyzer through a pipeline. Connect the other outlet of the ball valve to the fourth pressure regulating valve and the flue gas analyzer through a pipeline, and a complete denitrification NOx online partition synchronous measurement system based on the dilution method is formed. During actual use, compressed air enters the inside of the dryer through the intake pipe, and then enters the inside of the gas storage tank with a pressure gauge. The air inside the gas storage tank is transported to the fourth pressure regulating valve and the first pressure regulating valve, the second pressure regulating valve, and the third pressure regulating valve through pipelines respectively. The gas in the fourth pressure regulating valve directly enters the inside of the flue gas analyzer for analysis. The air entering the inside of the first pressure regulating valve, the second pressure regulating valve, and the third pressure regulating valve enters the inside of the first solenoid valve, the second solenoid valve, and the third solenoid valve through the first dilution sampler, the second dilution sampler, and the third dilution sampler. Then it is transported to the inside of the manifold by the first solenoid valve, the second solenoid valve, and the third solenoid valve, and finally enters the inside of the flue gas analyzer through the manifold for analysis. The NOx partition synchronous measurement system mainly consists of a zero gas treatment system, a dilution sampling system, and a synchronous wheel measurement system. The auxiliary systems include a backflush system and a calibration system. The zero gas treatment system consists of a dryer and a gas storage tank, which are used to filter and remove dust from the compressed air, and provide ultra-clean zero gas for the dilution sampling system and the analyzer. The dilution sampling system mainly consists of a sampling rod, a nano filter, a sonic orifice, a venturi, etc. This system mainly filters and samples the flue gas, ensuring that the sampled gas has representativeness while having a constant dilution ratio, and transports it to the analyzer through a sampling tube. The synchronous wheel measurement system consists of a measurement solenoid valve and an analyzer. Multiple solenoid valves control the entry sequence and time of each path of sampled gas into the analyzer, and the analyzer accurately measures the NOx concentration in the sampled gas. Through this system, the accuracy is the best when measuring low concentrations. The sampling and measurement system combining the dilution sampling method and the chemiluminescence method has the characteristics of not requiring water removal and a simple system, greatly reducing the probability of failure shutdown and maintenance cost, and is especially suitable for NOx measurement after ultra-low emissions. Description of the Drawings

[0027] Figure 1 Schematic diagram of the structure of the first embodiment of the denitration NOx online partition synchronous measurement system based on the dilution method provided by the present utility model;

[0028] Figure 2 Schematic diagram of the structure of the mobile bottom plate provided by the present utility model;

[0029] Figure 3 Provided by the present utility model Figure 2 Enlarged view of the position A shown;

[0030] Figure 4 Schematic diagram of the structure of the second embodiment of the denitration NOx online partition synchronous measurement system based on the dilution method provided by the present utility model;

[0031] Figure 5 Schematic diagram of the structure of the filter tube provided by the present utility model.

[0032] Reference numerals in the figure: 1, intake pipe; 2, dryer; 3, pressure gauge; 4, gas storage tank; 5, ball valve; 6, first pressure regulating valve; 7, second pressure regulating valve; 8, first dilution sampler; 9, second dilution sampler; 10, third dilution sampler; 11, third pressure regulating valve; 12, manifold; 13, first solenoid valve; 14, second solenoid valve; 15, third solenoid valve; 16, evacuator; 17, flue gas analyzer; 18, fourth pressure regulating valve; 19, mobile bottom plate; 20, mobile wheel; 21, mounting bolt; 22, fixing frame; 23, adjusting bolt; 24, rotating ring; 25, clamping plate; 26, contact pad; 27, fixing block; 28, first flange; 29, housing; 30, sealing cover; 31, second flange; 32, connecting pipe; 33, gas transmission pipe; 34, bolt; 35, filter hole; 36, threaded cover; 37, external threaded pipe; 38, dust collecting pipe; 39, baffle plate; 40, filter tube. Detailed implementation manners

[0033] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0034] Please refer to Figure 1 、 Figure 2 、 Figure 3 , wherein, Figure 1 Schematic diagram of the structure of the first embodiment of the denitration NOx online partition synchronous measurement system based on the dilution method provided by the present utility model; Figure 2 Schematic diagram of the structure of the mobile bottom plate provided by the present utility model; Figure 3 Provided by the present utility model Figure 2 Enlarged view of the position A shown. The denitration NOx online partition synchronous measurement system based on the dilution method includes: dryer 2, mobile bottom plate 19;

[0035] An intake pipe 1, the intake pipe 1 is installed at the inlet of a dryer 2, the outlet of the dryer 2 is installed with a gas storage tank 4 through a pipeline, a pressure gauge 3 is installed on the outer surface of the gas storage tank 4, the outlet of the gas storage tank 4 is installed with a first pressure regulating valve 6, a second pressure regulating valve 7 and a third pressure regulating valve 11 through pipelines respectively, the outlets of the first pressure regulating valve 6, the second pressure regulating valve 7 and the third pressure regulating valve 11 are installed with a second dilution sampler 9, a first dilution sampler 8 and a third dilution sampler 10 through pipelines respectively, the outlets of the second dilution sampler 9, the first dilution sampler 8 and the third dilution sampler 10 are installed with a second solenoid valve 14, a first solenoid valve 13 and a third solenoid valve 15 through pipelines respectively, the outlets of the second solenoid valve 14, the first solenoid valve 13 and the third solenoid valve 15 are all connected to the inlet of a manifold 12 through pipelines, and the outlet of the manifold 12 is connected to the inlet of a flue gas analyzer 17 through a pipeline;

[0036] A fourth pressure regulating valve 18, the inlet of the fourth pressure regulating valve 18 is connected to the other outlet of a ball valve 5 through a pipeline, and the outlet of the fourth pressure regulating valve 18 is connected to the inlet of a flue gas analyzer 17 through a pipeline;

[0037] Compressed gas enters the interior of the dryer 2 through the inlet pipe 1 and then enters the interior of the gas storage tank 4 through a pipeline. The detection limit of the instrument using the chemiluminescence method is the lowest, and it has the best accuracy when measuring low concentrations. The sampling measurement system combining the dilution sampling method and the chemiluminescence method has the characteristics of not requiring water removal and a simple system, greatly reducing the probability of failure shutdown and maintenance costs. It is especially suitable for the measurement of NOx after ultra-low emissions and is the preferred measurement method recommended by the US EPA. In this study, a NOx measurement system combining the dilution method and the chemiluminescence method was adopted. The flue gas analyzer selected the 42i analyzer of Thermo Fisher Scientific in the United States. The measurement principle of the NOx analyzer using the chemiluminescence method is as follows: Nitric oxide NO reacts with ozone O3 to produce a unique luminescence, and the intensity of this luminescence is linearly proportional to the concentration of NO. When the NO2 molecule excited by electrons decays to a lower energy state, it will emit infrared light. Specifically, NO + O3 → NO2 + O2 + hv. Nitrogen dioxide NO2 must first be converted into NO in order to use the chemiluminescence reaction for measurement. NO2 is converted into NO through a molybdenum NO2-to-NO converter heated to approximately 325 °C. The ambient air sample is inhaled into the 42i analyzer through the sampling plug. The sample flows through a capillary tube and then flows to the mode solenoid valve. The solenoid valve sends the sample directly to the reaction chamber in the NO mode or through the NO2-to-NO converter and then to the reaction chamber in the NOx mode. A flow sensor located before the reaction chamber is used to measure the sample flow rate. Dry air enters the 42i analyzer through the dry air plug, passes through a flow switch, and then through a silent discharge ozone generator.The ozone generator is used to generate ozone required for chemiluminescence reaction. In the reaction chamber, ozone reacts with NO in the sample to produce excited NO2 molecules. The photomultiplier tube (PMT) encapsulated in the thermoelectric cooler detects the luminescence generated in this reaction. The exhaust gas starts from the reaction chamber, moves to the pump through the ozone O3 converter, and then is discharged through the vent hole. The NO and NOx concentrations calculated in the NO and NOx modes are stored in the memory. The concentration difference is used to calculate the concentration of NO2. The Model 42i analyzer outputs the concentrations of NO, NO2, and NOx to the front panel display and provides analog output. At the same time, these data can also be obtained through the serial or Ethernet interface. The core components of the constant current dilution sampling technology are the Venturi and the sonic orifice. The structure of the Venturi is a convergent-divergent nozzle. The dilution gas accelerates in the convergent section. When the speed reaches a certain value, a negative pressure can be generated to form a vacuum. When the pressure difference between the inlet and outlet of the sonic orifice is greater than 0.46 times, the flow rate through the orifice no longer changes with the pressure change and reaches the speed of sound, thus generating a constant current. The ratio of the dilution gas flow rate to the flue gas flow rate is the dilution ratio. A constant dilution ratio is the prerequisite for ensuring accurate measurement. The inlet pressure of the sonic orifice is the flue gas pressure, and the outlet pressure is the Venturi negative pressure. According to the theory of the sonic orifice reaching the speed of sound condition, when the Venturi negative pressure is low enough, even if the operating conditions in the flue change, it does not affect the flue gas flow rate. The dilution gas flow rate of the Venturi depends on the inlet pressure of the Venturi and the nozzle aperture. Therefore, when the inlet pressure of the Venturi is constant and the nozzle aperture is fixed, that is, when the dilution gas flow rate is constant, the flow field structure and processing technology that can generate a negative pressure under subsonic conditions are a key technology in this project. The simultaneous sampling and time-sharing wheel measurement technical scheme is adopted. The measurement switching solenoid valve to the analyzer uses a 4-mm-inner-diameter tetrafluoroethylene tube, and the path is only 30 cm. The sampling flow rate is 500 mL / min, and it takes only 5 seconds to complete the update. The measurement time for each measuring point is 17 s, and the average value of the last 5 seconds is taken. It takes a total of 102 seconds for 6 points, and the NOx distribution in the SCR outlet flue can be updated quickly once, meeting the needs of zonal closed-loop control. Simultaneous sampling ensures that the sample gas is the flue gas at the same moment, and the measurement results reflect the true distribution of the NOx concentration. The NOx zonal synchronous measurement system mainly consists of a zero gas treatment system, a dilution sampling system, and a synchronous wheel measurement system. The auxiliary systems include a backflush system and a calibration system. The zero gas treatment system consists of a dryer and a gas storage tank, which are used to filter and remove dust from the compressed air and provide ultra-clean zero gas for the dilution sampling system and the analyzer. The dilution sampling system mainly consists of a sampling rod, a nano filter, a sonic orifice, and a Venturi, etc. This system mainly filters and samples the flue gas, ensuring that the sample gas is representative while having a constant dilution ratio, and transports it to the analyzer through the sampling tube. The synchronous wheel measurement system consists of a measurement solenoid valve and an analyzer. The solenoid valve controls the order and time of each path of sample gas entering the analyzer, and the analyzer accurately measures the NOx concentration in the sample gas.

[0038] The dryer 2 and the gas storage tank 4 form a zero-air treatment system, and the first pressure regulating valve 6, the second pressure regulating valve 7, and the third pressure regulating valve 11 and the first dilution sampler 8, the second dilution sampler 9, and the third dilution sampler 10 form an in-situ dilution sampling system.

[0039] Another outlet of the first dilution sampler 8, the second dilution sampler 9, and the third dilution sampler 10 is connected to the exhaust air 16 through a pipeline, and the flue gas analyzer 17, the first solenoid valve 13, the second solenoid valve 14, and the third solenoid valve 15 and the manifold 12 form a synchronous wheel measurement system.

[0040] Mounting bolts 21 are installed at the positions of the four corners at the bottom of the moving bottom plate 19, and the bottom ends of the mounting bolts 21 are rotatably connected to moving wheels 20;

[0041] The moving wheels 20 are small universal wheels that allow the moving bottom plate 19 to move at the placed position according to requirements, and the moving wheels 20 can be limited after moving to the corresponding positions.

[0042] The top of the moving bottom plate 19 is fixedly connected with a fixed frame 22, and fixed blocks 27 are fixedly connected to the positions on both sides at the top of the fixed frame 22;

[0043] The fixed frame 22 is installed at the position on the outer surface at the bottom of the moving bottom plate 19, and a through threaded hole is opened on one side of the fixed block 27.

[0044] Adjusting bolts 23 are threadedly connected to the opposite sides of the two fixed blocks 27, the other ends of the adjusting bolts 23 are rotatably connected to clamping plates 25 through rotating rings 24, and contact pads 26 are fixedly connected to the adjacent sides of the two clamping plates 25;

[0045] The flue gas analyzer 17 is placed on the top of the moving bottom plate 19, between the two clamping plates 25, and the contact pads 26 are in contact with both sides of the flue gas analyzer 17, which can increase the friction force.

[0046] The working principle of the denitration NOx online zoning synchronous measurement system and method based on the dilution method provided by the present invention is as follows:

[0047] First, connect the intake pipe 1 and the dryer 2, and connect the dryer 2 and the gas storage tank 4 through a pipeline. Then, connect the outlet of the gas storage tank 4 to the ball valve 5 through a pipeline. The two outlets of the ball valve 5 are respectively connected to the first pressure regulating valve 6, the second pressure regulating valve 7, the third pressure regulating valve 11, and the fourth pressure regulating valve 18 through pipelines. After that, only need to connect the first dilution sampler 8, the second dilution sampler 9, and the third dilution sampler 10 to the first pressure regulating valve 6, the second pressure regulating valve 7, and the third pressure regulating valve 11 through pipelines respectively. The outlets of the first dilution sampler 8, the second dilution sampler 9, and the third dilution sampler 10 are all connected to the first solenoid valve 13, the second solenoid valve 14, and the third solenoid valve 15 through pipelines, and connect the first solenoid valve 13, the second solenoid valve 14, and the third solenoid valve 15 to the manifold 12 through pipelines. The outlet of the manifold 12 is connected to the inlet of the flue gas analyzer 17 through a pipeline. Connect the other outlet of the ball valve 5 to the fourth pressure regulating valve 18 and the flue gas analyzer 17 through a pipeline, and a complete online partition synchronous measurement system for denitrification NOx based on the dilution method is formed. In actual use, the NOx partition synchronous measurement system mainly consists of a zero gas treatment system, a dilution sampling system, and a synchronous wheel measurement system. The auxiliary systems include a backflush system and a calibration system. The zero gas treatment system consists of two parts, the dryer 2 and the gas storage tank 4, which are used to filter and remove dust from the compressed air and provide ultra-clean zero gas for the dilution sampling system and the analyzer. The dilution sampling system mainly consists of a sampling rod, a nano filter, a sonic orifice, a Venturi, etc. This system mainly filters and samples the flue gas, ensuring that the sampled gas is representative and has a constant dilution ratio, and transports it to the analyzer through a sampling tube. The synchronous wheel measurement system consists of a measurement solenoid valve and an analyzer. Multiple solenoid valves control the entry sequence and time of each path of sampled gas into the analyzer, and the analyzer accurately measures the NOx concentration in the sampled gas.

[0048] Compared with the related technologies, the online partition synchronous measurement system and method for denitrification NOx based on the dilution method provided by the present utility model have the following beneficial effects:

[0049] In order to reduce the probability of failure shutdown and maintenance cost of the instrument using the chemiluminescence method, first connect the inlet pipe 1 and the dryer 2, and connect the dryer 2 and the gas storage tank 4 through a pipeline. Then connect the outlet of the gas storage tank 4 to the ball valve 5 through a pipeline, and connect the two outlets of the ball valve 5 to the first pressure regulating valve 6, the second pressure regulating valve 7, the third pressure regulating valve 11, and the fourth pressure regulating valve 18 through pipelines respectively. After that, only need to connect the first dilution sampler 8, the second dilution sampler 9, and the third dilution sampler 10 to the first pressure regulating valve 6, the second pressure regulating valve 7, and the third pressure regulating valve 11 through pipelines respectively. The outlets of the first dilution sampler 8, the second dilution sampler 9, and the third dilution sampler 10 are all connected to the first solenoid valve 13, the second solenoid valve 14, and the third solenoid valve 15 through pipelines, and connect the first solenoid valve 13, the second solenoid valve 14, and the third solenoid valve 15 to the manifold 12 through a pipeline. The outlet of the manifold 12 is connected to the inlet of the flue gas analyzer 17 through a pipeline, and connect the other outlet of the ball valve 5 to the fourth pressure regulating valve 18 and the flue gas analyzer 17 through a pipeline, thus forming a complete denitration NOx online partition synchronous measurement system using the dilution method. In actual use, the NOx partition synchronous measurement system mainly consists of a zero gas treatment system, a dilution sampling system, and a synchronous wheel measurement system. The auxiliary systems include a backflush system and a calibration system. The zero gas treatment system consists of two parts, the dryer 2 and the gas storage tank 4, which are used to filter and remove dust from the compressed air and provide ultra-clean zero gas for the dilution sampling system and the analyzer. The dilution sampling system mainly consists of a sampling rod, a nano filter, a sonic orifice, and a Venturi, etc. This system mainly filters and samples the flue gas, ensuring that the sampled gas is representative while having a constant dilution ratio, and transports it to the analyzer through a sampling pipe. The synchronous wheel measurement system consists of a measurement solenoid valve and an analyzer. Multiple solenoid valves control the entry sequence and time of each path of sampled gas into the analyzer, and the analyzer accurately measures the NOx concentration in the sampled gas. Through this system, the accuracy is the best when measuring low concentrations. The sampling measurement system combining the dilution sampling method and the chemiluminescence method has the characteristics of not requiring water removal and a simple system, greatly reducing the probability of failure shutdown and maintenance cost, and is especially suitable for NOx measurement after ultra-low emissions.

[0050] Second Embodiment

[0051] Please refer to Figure 4 - Figure 5 , Figure 4 which is a schematic structural diagram of the second embodiment of the denitration NOx online partition synchronous measurement system based on the dilution method provided by the present utility model; Figure 5This is a schematic diagram of the structure of the filter tube. Based on the first embodiment of the present application, a denitrification NOx on-line partition synchronous measurement system and method based on the dilution method are provided. Another denitrification NOx on-line partition synchronous measurement system based on the dilution method is proposed in the second embodiment of the present application. The second embodiment is only a preferred manner of the first embodiment, and the implementation of the second embodiment will not affect the independent implementation of the first embodiment.

[0052] Specifically, the difference between the denitrification NOx on-line partition synchronous measurement system and method based on the dilution method provided in the second embodiment of the present application is that the other end of the intake pipe 1 is installed with a gas transmission pipe 33 through a first flange 28, and the other end of the gas transmission pipe 33 is fixedly connected to a housing 29;

[0053] The housing 29 is conical, specifically referring to Figure 4 , a hole through which the dust collecting pipe 38 can pass is opened at the position of the outer surface of the housing 29 at the bottom, and the position through which the dust collecting pipe 38 is installed is sealed by welding to ensure that the inside of the housing 29 is sealed.

[0054] The other end of the housing 29 is installed with a sealing cover 30 through bolts 34. One end of the sealing cover 30 is fixedly connected to a filter tube 40 with filter holes 35. The other end of the filter tube 40 is fixedly connected to a retaining disc 39. A dust collecting pipe 38 is fixedly connected to the outer surface of the filter tube 40 near the other end and at the bottom. The other end of the dust collecting pipe 38 is installed with an external threaded pipe 37 with a threaded cap 36;

[0055] The retaining disc 39 is also provided with filter holes 35. An opening is provided at the position where the sealing cover 30 installs the filter tube 40 to facilitate air circulation. The position of the dust collecting pipe 38 refers to Figure 5 .

[0056] The other end of the sealing cover 30 is fixedly connected to a connecting pipe 32, and the other end of the connecting pipe 32 is fixedly connected to a second flange 31;

[0057] The connecting pipe 32 and the filter tube 40 are adjacent. The other end of the second flange 31 is connected to the intake device.

[0058] Compared with the related technology, the denitrification NOx on-line partition synchronous measurement system and method provided by the present invention have the following beneficial effects:

[0059] To prevent dust in the air from directly entering the interior of the dryer 2, at the other end of the intake pipe 1, an air delivery pipe 33 with a housing 29 is installed through a first flange 28. At the other end of the housing 29, a filter pipe 40 with filter holes 35 is installed through a sealing cover 30. A retaining plate 39 with filter holes 35 is installed at the other end of the filter pipe 40. A dust collection pipe 38 is installed at a position below one end of the outer surface of the filter pipe 40 near the retaining plate 39. Then, only a detachable threaded cap 36 needs to be installed at the bottom end of the dust collection pipe 38 through an external threaded pipe 37. During actual use, compressed air enters the interior of the filter pipe 40 through the connecting pipe 32. The air will be discharged through the filter holes 35 in the filter pipe 40 and the retaining plate 39, while the dust will be left inside the filter pipe 40. Due to the fixed push of the air flow, the dust will be collected on one side of the retaining plate 39. When the dust accumulates to a certain extent, it will fall into the interior of the dust collection pipe 38 under the influence of gravity. The filtered air enters the interior of the dryer 2 through the air delivery pipe 33. The staff only needs to regularly open the threaded cap 36 to clean the dust inside the dust collection pipe 38. With this structure, the air entering the interior of the dryer 2 can be filtered, preventing dust from directly entering the interior of the dryer 2, which is beneficial to improving the detection accuracy of the flue gas analyzer 17.

[0060] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. An on-line partition synchronous measurement system for denitrifying NOx based on the dilution method, characterized in that, Including: A dryer and a movable bottom plate; An air inlet pipe, which is installed at the inlet of the dryer. A gas storage tank is installed through a pipe at the outlet of the dryer. A pressure gauge is installed on the outer surface of the gas storage tank. The outlet of the gas storage tank is respectively installed with a first pressure regulating valve, a second pressure regulating valve and a third pressure regulating valve through pipes. The outlets of the first pressure regulating valve, the second pressure regulating valve and the third pressure regulating valve are respectively installed with a second dilution sampler, a first dilution sampler and a third dilution sampler through pipes. The outlets of the second dilution sampler, the first dilution sampler and the third dilution sampler are respectively installed with a second solenoid valve, a first solenoid valve and a third solenoid valve through pipes. The outlets of the second solenoid valve, the first solenoid valve and the third solenoid valve are all connected to the inlet of a manifold through pipes. The outlet of the manifold is connected to the inlet of a flue gas analyzer through a pipe; A fourth pressure regulating valve, the inlet of which is connected to the other outlet of a ball valve through a pipe, and the outlet of which is connected to the inlet of the flue gas analyzer through a pipe.

2. The on-line partition synchronous measurement system for denitrifying NOx based on the dilution method according to claim 1, wherein The dryer and the gas storage tank form a zero gas treatment system, and the first pressure regulating valve, the second pressure regulating valve and the third pressure regulating valve and the first dilution sampler, the second dilution sampler and the third dilution sampler form an in-situ dilution sampling system.

3. The denitration NOx online partition synchronous measurement system based on the dilution method according to claim 1, wherein The other outlets of the first dilution sampler, the second dilution sampler and the third dilution sampler are connected to the exhaust air through pipes, and the flue gas analyzer, the first solenoid valve, the second solenoid valve and the third solenoid valve and the manifold form a synchronous wheel measurement system.

4. The on-line partition synchronous measurement system for denitrification NOx based on the dilution method according to claim 1, characterized in that, Installation bolts are installed at the positions of the four corners at the bottom of the movable bottom plate, and the bottom ends of the installation bolts are rotatably connected with moving wheels.

5. The on-line partition synchronous measurement system for denitrification NOx based on the dilution method according to claim 1, characterized in that The top of the movable bottom plate is fixedly connected with a fixed frame, and fixed blocks are fixedly connected to the positions on both sides at the top of the fixed frame.

6. The denitration NOx online partition synchronous measurement system based on the dilution method according to claim 5, wherein Adjusting bolts are threadedly connected to the opposite sides of the two fixed blocks. The other ends of the adjusting bolts are rotatably connected with clamping plates through rotating rings. Contact pads are fixedly connected to the adjacent sides of the two clamping plates.

7. The on-line partition synchronous measurement system for denitrification NOx based on the dilution method according to claim 1, characterized in that, The other end of the air inlet pipe is installed with an air delivery pipe through a first flange, and the other end of the air delivery pipe is fixedly connected with a housing.

8. The on-line partition synchronous measurement system for denitrification NOx based on the dilution method according to claim 7, characterized in that, The other end of the housing is installed with a sealing cover through bolts. One end of the sealing cover is fixedly connected with a filter pipe with filter holes. The other end of the filter pipe is fixedly connected with a baffle plate. A dust collecting pipe is fixedly connected to the outer surface of the filter pipe near the other end and at the bottom. The other end of the dust collecting pipe is installed with an external threaded pipe with a threaded cover.

9. The on-line partition synchronous measurement system for denitrification NOx based on the dilution method according to claim 8, characterized in that, The other end of the sealing cover is fixedly connected with a connecting pipe, and the other end of the connecting pipe is fixedly connected with a second flange.

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