Analyzer for rapidly measuring NOx concentration
By setting up multiple sampling and control units on the flue, and using compressed air to create negative pressure for real-time NOx concentration detection, the problems of detection lag and inaccurate distribution in existing technologies are solved, achieving precise ammonia injection control and improving denitrification efficiency and environmental protection effects.
Patent Information
- Application Number
- CN202520220126.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-12
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2035-02-12
AI Technical Summary
Existing NOx concentration measurement methods in the flue gas denitrification system of thermal power generating units suffer from detection lag and inaccurate determination of NOx concentration distribution in the flue, which prevents the SCR denitrification system from achieving optimal ammonia injection control, affecting denitrification efficiency and environmental pollution.
Design an analyzer for rapid NOx concentration measurement. Multiple sampling and detection units are set along the flue direction and fixed to the flue by connecting components. Compressed air is sprayed from nozzles to create negative pressure, enabling real-time sampling and detection of flue gas. The NOx concentration is monitored in real time by sensors, and the control unit coordinates the sampling sequence of each detection point to reduce detection errors.
It enables real-time monitoring and distribution detection of NOx concentration in the flue, providing a basis for precise ammonia injection, reducing detection lag and errors, and ensuring the efficient operation of the SCR denitrification system.
Smart Images
Figure CN223857178U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to vehicle forming technical field, concretely relates to an analyzer for fast measurement of NOx concentration. BACKGROUND
[0002] The tail gas denitration system of the thermal power generating unit mainly adopts the principle of "ammonia selective catalytic reduction method (SCR)", utilizes the reaction of NH3 (ammonia) and NO X (nitrogen oxide, mainly NO and NO2) to generate N2 and H2O. However, the application effect of the SCR denitration system is influenced by the NH3 release amount, air dilution amount, working temperature and other factors, and after the denitration system design is finalized, the NH3 release amount becomes the key amount that can be adjusted in the operation process. Excessive NH3 release will affect the denitration efficiency and increase the cost, at the same time, the mutual reaction of excessive NH3 and SO3 contained in the tail gas generates NH4HSO4 and (NH4)2SO4, which will cause the denitration catalyst activity to decrease and the denitration effect to weaken; insufficient NH3 release will lead to insufficient reaction, NO X pollutant emission exceeding the standard, causing secondary environmental pollution.
[0003] The principle of the original NOx concentration measurement is to utilize the CEMS (flue gas automatic monitoring system) instrument to measure, this way needs to lead the flue gas to the CEMS chamber, and detects after pre-treating the flue gas, so generally sets a sampling point in the middle in the single flue, or sets a sampling point at the head and tail, to simultaneously carry out flue gas sampling detection, adopts this detection way, and the single detection point leads to long detection lag time due to pre-treatment introduction and re-detection, at the same time, the few flue sampling points cannot accurately judge the NO X Concentration distribution change, so as to difficult to guarantee the best ammonia injection amount of the SCR denitration system.
[0004] In view of the above-mentioned defects, the utility model creator finally obtains the utility model after long time research and practice. CONTENT OF THE UTILITY MODEL
[0005] The utility model provides a kind of analyzer for the quick measurement of NOx concentration, including several sampling detection parts and control part, the sampling detection part is arranged along the extension direction of flue;The sampling detection part includes connecting assembly and detection component, the detection component is fixedly arranged on the flue by the connecting assembly, and the detection component includes detection block, the detection block is provided with smoke inlet hole, smoke outlet hole, detection hole and negative pressure hole, one end of the smoke inlet hole and the smoke outlet hole is communicated with the flue, one end of the smoke inlet hole is communicated with the smoke outlet hole by transition hole, the other end of the smoke outlet hole is communicated with the negative pressure hole, the detection hole is communicated with the smoke outlet hole, the smoke outlet hole and the negative pressure hole are coaxially arranged, the negative pressure hole is provided with the spray head that compressed air is axially sprayed into the smoke outlet hole, the detection hole is connected with sensor, and the detection head of the sensor is arranged in the smoke outlet hole;The spray head of each sampling detection part is connected with gas source by corresponding air tube, and gas valve is arranged on each air tube, each gas valve is connected with the control part, and the sensor of each sampling detection part is connected with the control part.
[0006] Preferably, each sampling detection part is arranged alternately along the flow direction of flue gas in the flue.
[0007] Preferably, the smoke inlet hole and the smoke outlet hole are arranged linearly in sequence along the flow direction of flue gas in the flue.
[0008] Preferably, the axes of the smoke inlet hole and the smoke outlet hole are arranged in parallel, and the axes of the smoke inlet hole and the smoke outlet hole are arranged perpendicularly to the extension direction of the flue.
[0009] Preferably, the axis of the transition hole is arranged perpendicularly to the axes of the smoke inlet hole and the smoke outlet hole, and the detection hole is coaxially arranged with the transition hole.
[0010] Preferably, the connecting assembly includes a first connecting plate, a second connecting plate and a connecting pipe, the connecting pipe is arranged as a hollow tubular member, a first communication hole is arranged on the flue, the connecting pipe is fixedly arranged on the flue, the first communication hole and the connecting pipe are coaxially arranged, one end of the connecting pipe is fixedly connected with the flue, and the other end is fixedly provided with the second connecting plate, the first connecting plate is fixedly arranged on the detection block, and the first connecting plate and the second connecting plate are detachably connected.
[0011] Preferably, two through holes are arranged on the first connecting plate, the two through holes correspond to the smoke inlet hole and the smoke outlet hole respectively, the through holes are coaxially arranged with the corresponding smoke inlet hole or smoke outlet hole, a partition plate is arranged perpendicularly on the first connecting plate, and the partition plate is arranged between the two through holes.
[0012] Preferably, the second connecting plate is provided with a second communication hole, and the first communication hole and the second communication hole are coaxially arranged.
[0013] Preferably, the first communication hole and the second communication hole have the same aperture, the partition plate is provided with a guide plate on a side close to the smoke outlet hole, the two guide plates are symmetrically arranged on two sides of the smoke outlet hole, one end of the guide plate is fixedly connected with the first connecting plate, one side edge of the guide plate is fixedly connected with the partition plate, and the other side edge is provided with a clearance from the inner wall of the first communication hole and the second communication hole.
[0014] Preferably, the end of the partition plate away from the first connecting plate is fixedly provided with a material falling plate, and the material falling plate extends downwardly in a direction away from the first connecting plate.
[0015] Compared with the prior art, the beneficial effects of the utility model are that the sampling and detecting part can be directly fixed on the flue wall to perform real-time sampling and detection on the flue gas in the flue, so that multiple sampling and detecting points can be arranged on the flue, the NOx concentration detection data lag caused by too long sampling time is avoided, and multiple sampling and detecting points are also convenient for detecting the NOx concentration distribution in the flue, thereby providing a basic guarantee for realizing precise ammonia injection. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 It is a structural schematic view of the analyzer for rapidly measuring the NOx concentration;
[0017] Figure 2 It is a schematic view of the sampling and detecting part arranged on the flue;
[0018] Figure 3 It is a front view of the connecting structure of the connecting assembly and the detecting assembly;
[0019] Figure 4 It is a side view of the connecting structure of the connecting assembly and the detecting assembly.
[0020] Numerals in the drawing represent:
[0021] 1-sampling and detecting part; 2-flue; 11-detecting block; 12-nozzle; 13-sensor; 14-connecting assembly; 15-partition plate; 16-guide plate; 17-material falling plate; 21-first communication hole; 111-smoke inlet hole; 112-smoke outlet hole; 113-detecting hole; 114-negative pressure hole; 115-transition hole; 141-first connecting plate; 142-second connecting plate; 143-connecting pipe; 144-first connecting hole; 145-second connecting hole; 146-passing hole; 147-second communication hole. DETAILED DESCRIPTION
[0022] The above and other technical features and advantages of the present application will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings.
[0023] Embodiment one
[0024] As shown in Figure 1 and Figure 2 , the structure schematic diagram of the analyzer for quickly measuring NOx concentration is shown in Figure 1 Figure 2 The setting schematic diagram of the sampling detection part on the flue is shown in
[0025] The analyzer for quickly measuring NOx concentration comprises a plurality of sampling detection parts 1 and a control part, the sampling detection parts 1 are arranged along the extension direction of the flue 2; the sampling detection part 1 comprises a connecting assembly 14 and a detection assembly, the detection assembly is fixedly arranged on the flue 2 through the connecting assembly 14, the detection assembly comprises a detection block 11, the detection block 11 is internally provided with a smoke inlet hole 111, a smoke outlet hole 112, a detection hole 113 and a negative pressure hole 114, one end of the smoke inlet hole 111 and the smoke outlet hole 112 are both communicated with the flue 2, one end of the smoke inlet hole 111 is communicated with the smoke outlet hole 112 through a transition hole 115, the other end of the smoke outlet hole 112 is communicated with the negative pressure hole 114, the detection hole 113 is communicated with the smoke outlet hole 112, the smoke outlet hole 112 and the negative pressure hole 114 are coaxially arranged, a spray head 12 is arranged on the negative pressure hole 114, the spray head 12 sprays heated compressed air into the smoke outlet hole 112 in the axial direction, so that negative pressure is formed in the smoke outlet hole 112, and then the flue gas in the flue 2 enters the smoke outlet hole 112 through the smoke inlet hole 111, a sensor 13 is connected to the detection hole 113, the detection head of the sensor 13 is arranged in the smoke outlet hole 112, when the flue gas in the flue 2 enters the smoke outlet hole 112, the sensor 13 detects the NOx concentration of the flue gas in the smoke outlet hole 112, so as to judge the NOx concentration in the flue 2, the spray head 12 of each sampling detection part 1 is connected to the gas source through a corresponding air pipe, a gas valve is arranged on each air pipe, each gas valve is connected to the control part, and the sensor 13 of each sampling detection part 1 is connected to the control part.
[0026] The heated compressed air can also preheat the detection block 11, so as to avoid the reaction caused by the temperature drop of the detection block 11 to the flue gas.
[0027] Preferably, the sampling detection parts 1 are alternately arranged along the flow direction of the flue gas in the flue 2, so as to reduce the disturbance of compressed air to the flue gas between adjacent sampling detection parts 1.
[0028] Generally, the smoke inlet hole 111 and the smoke outlet hole 112 are arranged in sequence along the flow direction of the flue gas in the flue 2, which reduces the disturbance of the compressed air discharged from the smoke outlet hole 112 to the flue gas flowing into the smoke inlet hole 111, and affects the detection result.
[0029] By controlling each gas valve through the control part, the jet sampling of each sampling detection part 1 can be realized in sequence, and when the detection is performed, the sampling detection of each sampling detection part 1 is performed in sequence in the opposite direction of the flue gas flow in the flue 2, so that the compressed gas sprayed by the sampling detection part 1 located upstream of the flue gas flow does not affect the flue gas sampling of the downstream sampling detection part 1.
[0030] The control part can realize real-time monitoring of the NOx concentration distribution in the flue 2 by collecting the detection data of each sensor 13, and can comprehensively consider the NOx concentration of each partition in the flue 2 to adjust the ammonia injection amount for denitration, so as to avoid the influence of the detection data of a single detection point on the adjustment of the ammonia injection amount for denitration, and also reduce the influence of the detection error caused by the fluctuation of the NOx concentration on the ammonia injection amount for denitration.
[0031] The sampling detection part 1 of the utility model can be directly fixed on the wall of the flue 2 to perform real-time sampling detection on the flue gas in the flue 2, so that multiple sampling detection points can be arranged on the flue 2, which can avoid the lag of the NOx concentration detection data caused by too long sampling time, and at the same time, the multiple sampling detection points are also convenient for detecting the NOx concentration distribution in the flue 2, which provides a basic guarantee for realizing accurate ammonia injection.
[0032] At the same time, since the compressed air sprayed through the nozzle 12 forms a negative pressure, the blockage formed in the smoke outlet hole 112 during long-term use can be avoided, and the utility model can be used stably in a high-dust environment for a long time.
[0033] Example two
[0034] Preferably, the axes of the smoke inlet hole 111 and the smoke outlet hole 112 are arranged in parallel, and the axes of the smoke inlet hole 111 and the smoke outlet hole 112 are arranged perpendicularly to the extension direction of the flue 2, so as to avoid that the flue gas in the flue 2 directly enters the smoke inlet hole 111 and the smoke outlet hole 112 in a flowing state, causing inaccurate detection. Generally, the smoke inlet hole 111 and the smoke outlet hole 112 are arranged symmetrically with the axis of the detection block 11, which also provides a better arrangement space for the detection hole 113, the negative pressure hole 114 and the transition hole 115.
[0035] Generally, the axis of the transition hole 115 is perpendicular to the axes of the smoke inlet hole 111 and the smoke outlet hole 112, and the detection hole 113 is coaxial with the transition hole 115, so that the sensor 13 can directly detect the smoke concentration of the smoke outlet hole 112 through the transition hole 115, thereby improving the detection accuracy.
[0036] Preferably, the compressed air pressure ejected from the spray head 12 is set to 0.3MP-0.5MP to ensure that a better negative pressure is provided while also avoiding disturbing the flue gas in the flue 2.
[0037] The connecting assembly 14 and the detection assembly are made of stainless steel, which can prevent corrosion of the flue gas.
[0038] Embodiment Three
[0039] As shown in Figure 3 and Figure 4 , the connecting structure of the connecting assembly and the detection assembly is a front view; Figure 3 the connecting structure of the connecting assembly and the detection assembly is a side view. Figure 4 the connecting structure of the connecting assembly and the detection assembly is a side view.
[0040] The connecting assembly 14 includes a first connecting plate 141, a second connecting plate 142, and a connecting pipe 143. The connecting pipe 143 is provided as a hollow tubular member. The flue 2 is provided with a first communication hole 21. The connecting pipe 143 is fixedly arranged on the flue 2. The first communication hole 21 and the connecting pipe 143 are coaxially arranged. One end of the connecting pipe 143 is fixedly connected to the flue 2, and the other end is fixedly provided with the second connecting plate 142. The first connecting plate 141 is fixedly arranged on the detection block 11. The first connecting plate 141 and the second connecting plate 142 are detachably connected, thereby realizing the fixation of the detection assembly on the flue 2 through the connecting assembly 14.
[0041] Preferably, the first connecting plate 141 is provided with a first connecting hole 144, and the second connecting plate 142 is provided with a second connecting hole 145. The first connecting hole 144 and the second connecting hole 145 are arranged one by one in correspondence. A connecting bolt passes through the corresponding first connecting hole 144 and second connecting hole 145 in sequence and is threadedly connected with a connecting nut, thereby realizing the detachable connection of the first connecting plate 141 and the second connecting plate 142.
[0042] Generally, the first connecting plate 141 is provided with two through holes 146, and the two through holes 146 correspond to the smoke inlet hole 111 and the smoke outlet hole 112 respectively. The through hole 146 is coaxially arranged with the corresponding smoke inlet hole 111 or smoke outlet hole 112. The first connecting plate 141 is vertically provided with a partition plate 15, and the partition plate 15 is arranged between the two through holes 146, so as to avoid the influence of the compressed air discharged from the smoke outlet hole 112 on the smoke flowing into the smoke inlet hole 111. It is worth pointing out that a one-way valve can be arranged on the two through holes 146 to realize directional flow of air flow.
[0043] The second connecting plate 142 is provided with a second communication hole 147, and the first communication hole 21 and the second communication hole 147 are coaxially arranged, so as to ensure that the smoke inlet hole 111 and the smoke outlet hole 112 are communicated with the flue 2 through the first communication hole 21 and the second communication hole 147.
[0044] Preferably, the first communication hole 21 and the second communication hole 147 have the same hole diameter. The partition plate 15 is provided with a guide plate 16 on the side close to the smoke outlet hole 112. The two guide plates 16 are symmetrically arranged on the two sides of the smoke outlet hole 112. One end of the guide plate 16 is fixedly connected with the first connecting plate 141. One side edge of the guide plate 16 is fixedly connected with the partition plate 15, and the other side edge is provided with a avoiding gap from the inner wall of the first communication hole 21 and the second communication hole 147, so as to facilitate the partition plate 15 and the guide plate 16 to extend into the flue 2, and further reduce the influence of compressed air on the smoke flowing into the smoke inlet hole 111. The avoiding gap is generally 2mm-5mm, which can ensure convenient installation and avoid the mutual influence between the smoke inlet hole 111 and the smoke outlet hole 112.
[0045] Preferably, the end of the partition plate 15 away from the first connecting plate 141 is fixedly provided with a material falling plate 17. The material falling plate 17 extends downward in a direction away from the first connecting plate 141. Similarly, the guide plate 16 is also inclined to facilitate the smoke dust to be pushed to the material falling plate 17 by compressed air and slide under its own gravity after accumulating on the partition plate 15, so as to avoid blockage on the partition plate 15.
[0046] The connection position of the nozzle 12 and the negative pressure hole 114, the connection position of the sensor 13 and the detection hole 113, and the first connecting plate 141 and the second connecting plate 142 are all provided with a gasket, so as to ensure the sealing property of the connection position.
[0047] The above merely describes preferred embodiments of the present application, which are merely illustrative but not restrictive. Those skilled in the art understand that many changes, modifications, or even equivalences can be made to the present application within the spirit and scope of the present application as defined in the claims, and all will fall within the protection scope of the present application.
Claims
1. An analyzer for rapid measurement of NOx concentration, characterized by, The application relates to a sampling and detecting device for a flue, which comprises a plurality of sampling and detecting units arranged along the extension direction of the flue, a connecting assembly and a detecting assembly, the detecting assembly is fixedly arranged on the flue through the connecting assembly, the detecting assembly comprises a detecting block, the detecting block is internally provided with an inlet hole, an outlet hole, a detecting hole and a negative pressure hole, one end of the inlet hole and the outlet hole is communicated with the flue, one end of the inlet hole is communicated with the outlet hole through a transition hole, the other end of the outlet hole is communicated with the negative pressure hole, the detecting hole is communicated with the outlet hole, the outlet hole and the negative pressure hole are coaxially arranged, a nozzle for spraying compressed air into the outlet hole is arranged on the negative pressure hole, a sensor is connected with the detecting hole, and the detecting head of the sensor is arranged in the outlet hole; the nozzles of the sampling and detecting units are connected with a gas source through corresponding air tubes, air valves are arranged on the air tubes, the air valves are connected with a control unit, and the sensors of the sampling and detecting units are connected with the control unit.
2. The analyzer for rapidly measuring the concentration of NOx according to claim 1, wherein, The sampling and detecting units are alternately arranged along the flow direction of flue gas in the flue.
3. The analyzer for rapidly measuring the concentration of NOx according to claim 2, wherein, The inlet hole and the outlet hole are linearly arranged in sequence along the flow direction of flue gas in the flue.
4. The analyzer for rapidly measuring the concentration of NOx according to claim 3, wherein, The axes of the inlet hole and the outlet hole are arranged in parallel, and the axes of the inlet hole and the outlet hole are arranged perpendicularly to the extension direction of the flue.
5. The analyzer for rapidly measuring the concentration of NOx according to claim 4, wherein, The axis of the transition hole is arranged perpendicularly to the axes of the inlet hole and the outlet hole, and the detecting hole is coaxially arranged with the transition hole.
6. The analyzer for rapidly measuring the concentration of NOx according to claim 1, wherein, The connecting assembly comprises a first connecting plate, a second connecting plate and a connecting pipe, the connecting pipe is arranged as a hollow tubular member, a first communicating hole is arranged on the flue, the connecting pipe is fixedly arranged on the flue, the first communicating hole and the connecting pipe are coaxially arranged, one end of the connecting pipe is fixedly connected with the flue, and the other end is fixedly provided with the second connecting plate, the first connecting plate is fixedly arranged on the detecting block, and the first connecting plate and the second connecting plate are detachably connected.
7. The analyzer for rapidly measuring the concentration of NOx according to claim 6, wherein, Two through holes are arranged on the first connecting plate, the through holes correspond to the inlet hole and the outlet hole respectively, the through holes are coaxially arranged with the corresponding inlet hole or outlet hole, a partition plate is arranged perpendicularly on the first connecting plate, and the partition plate is arranged between the two through holes.
8. The analyzer for rapidly measuring the concentration of NOx according to claim 7, wherein, The second connecting plate is provided with a second communicating hole, and the first communicating hole and the second communicating hole are coaxially arranged.
9. The analyzer for rapidly measuring the concentration of NOx according to claim 8, wherein, The hole diameters of the first communicating hole and the second communicating hole are the same, the side of the partition plate close to the outlet hole is provided with a guide plate, the guide plates are symmetrically arranged on the two sides of the outlet hole, one end of the guide plate is fixedly connected with the first connecting plate, one side edge of the guide plate is fixedly connected with the partition plate, and the other side edge is provided with a clearance from the inner wall of the first communicating hole and the second communicating hole.
10. The analyzer for rapidly measuring the concentration of NOx according to claim 9, wherein, The end of the partition plate away from the first connecting plate is fixedly provided with a material falling plate, and the material falling plate extends downwardly in a direction away from the first connecting plate.