Sampling device for rapidly measuring NOx

Abstract

The utility model discloses a sampling device for quickly measuring NOx, which comprises a connecting part and a detection part, the detection part is fixedly arranged on a flue through the connecting part, the detection part comprises a detection block, a smoke inlet hole, a smoke outlet hole, a detection hole and a negative pressure hole are arranged in the detection block, one end of the smoke inlet hole and one end of the smoke outlet hole are communicated with the flue, and the other end of the smoke outlet hole is communicated with the negative pressure hole. One end of the smoke inlet hole is communicated with the smoke outlet hole through the 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 a spray head for axially spraying compressed air into the smoke outlet hole, the detection hole is connected with a sensor, and a detection head of the sensor is arranged in the smoke outlet hole; according to the utility model, the arrangement of a sampling structure of a sampling pipe and a CEMS chamber in the prior art is canceled, and the device can be directly connected to the flue wall to sample flue gas in the flue, so that the delay of NOx concentration detection data caused by overlong sampling time is avoided, and a basic guarantee is provided for realizing accurate ammonia injection.

Description

Technical Field

[0001] This utility model relates to the field of denitrification control technology in thermal power generation, specifically to a sampling device for rapid NOx measurement. Background Technology

[0002] The exhaust gas denitrification system of thermal power generating units mainly adopts the principle of "selective catalytic reduction (SCR) with ammonia injection", utilizing NH3 (ammonia) and NO. X (Nitrogen oxides, mainly NO and NO2) react to produce N2 and H2O. However, the effectiveness of SCR denitrification systems is affected by factors such as NH3 release, air dilution, and operating temperature. Furthermore, once the denitrification system design is finalized, NH3 release becomes a key adjustable factor during operation. Excessive NH3 release affects denitrification efficiency and increases costs. Simultaneously, excess NH3 reacts with SO3 in the exhaust gas, generating NH4HSO4 and (NH4)2SO4, which reduce the activity of the denitrification catalyst and weaken the denitrification effect. Insufficient NH3 release leads to incomplete reaction, resulting in NO... X Excessive pollutant emissions caused secondary environmental pollution.

[0003] The original principle of NOx concentration measurement was based on CEMS (Continuous Flue Gas Monitoring System) instruments. This method requires the flue gas to be introduced into the CEMS chamber, which involves long pipelines and pretreatment of the flue gas. It also has a single-point lag of approximately 45-60 seconds, making it unsuitable for rapid and accurate NOx measurement. X The concentration of ammonia is too high, making it difficult to guarantee the optimal ammonia injection rate for the SCR denitrification system.

[0004] In view of the above-mentioned defects, the creator of this utility model has finally obtained this utility model after a long period of research and practice. Utility Model Content

[0005] To address the aforementioned technical deficiencies, the present invention provides a sampling device for rapid NOx measurement, comprising a connecting part and a detection part. The detection part is fixedly mounted on a flue via the connecting part. The detection part includes a detection block, which contains a smoke inlet, a smoke outlet, a detection hole, and a negative pressure hole. One end of the smoke inlet and the smoke outlet are both connected to the inside of the flue. One end of the smoke inlet is connected to the smoke outlet via a transition hole, and the other end of the smoke outlet is connected to the negative pressure hole. The detection hole is connected to the smoke outlet, and the smoke outlet and the negative pressure hole are coaxially arranged. A nozzle is provided on the negative pressure hole for axially ejecting compressed air into the smoke outlet. A sensor is connected to the detection hole, and the detection head of the sensor is disposed inside the smoke outlet.

[0006] Preferably, the axes of the smoke inlet and the smoke outlet are arranged parallel to each other, and the axes of the smoke inlet and the smoke outlet are arranged perpendicular to the extension direction of the flue.

[0007] Preferably, the axis of the transition hole is perpendicular to the axes of the smoke inlet and the smoke outlet, and the detection hole is coaxial with the transition hole.

[0008] Preferably, the smoke inlet and the smoke outlet are arranged sequentially in a straight line along the flow direction of the flue gas.

[0009] Preferably, the connecting part includes a first connecting plate, a second connecting plate, and a connecting pipe. The connecting pipe is configured as a hollow tubular component. A first communicating hole is provided on the flue. The connecting pipe is fixedly installed on the flue. The first communicating hole and the connecting pipe are coaxially arranged. One end of the connecting pipe is fixedly connected to the flue, and the other end is fixedly provided with the second connecting plate. The first connecting plate is fixedly installed on the detection block. The first connecting plate and the second connecting plate are detachably connected.

[0010] Preferably, the first connecting plate is provided with a first connecting hole, and the second connecting plate is provided with a second connecting hole. The first connecting hole and the second connecting hole are provided in a one-to-one correspondence. The connecting bolt passes through the corresponding first connecting hole and the second connecting hole in sequence and is threadedly connected to the connecting nut.

[0011] Preferably, the first connecting plate is provided with two through holes, which correspond to the smoke inlet and the smoke outlet respectively. The through holes are coaxially arranged with the corresponding smoke inlet or smoke outlet. A partition plate is vertically arranged on the first connecting plate, and the partition plate is disposed between the two through holes.

[0012] Preferably, the second connecting plate is provided with a second connecting hole, and the first connecting hole and the second connecting hole are coaxially arranged.

[0013] Preferably, the first connecting hole and the second connecting hole have the same diameter. A guide plate is provided on the side of the partition plate near the smoke outlet. The two guide plates are symmetrically arranged on both sides of the smoke outlet. One end of the guide plate is fixedly connected to the first connecting plate. One side of the guide plate is fixedly connected to the partition plate. The other side is provided with a clearance gap with the inner wall of the first connecting hole and the second connecting hole.

[0014] Preferably, a material drop plate is fixedly provided at the end of the partition plate away from the first connecting plate, and the material drop plate extends downward at an angle away from the first connecting plate.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model eliminates the sampling structure of sampling tube and CEMS chamber in the prior art, and can be directly connected to the flue wall to sample the flue gas in the flue, avoiding the lag in NOx concentration detection data caused by excessive sampling time, and providing a basic guarantee for achieving accurate ammonia injection. Attached Figure Description

[0016] Figure 1 This is a structural view of the sampling device for rapid NOx measurement;

[0017] Figure 2 This is a front view of the connection structure between the connecting part and the detection part;

[0018] Figure 3 This is a side view of the connection structure between the connecting part and the detection part.

[0019] The numbers in the image represent:

[0020] 1-Detection block; 2-Flue; 3-Nozzle; 4-Sensor; 5-Connecting part; 6-Separator plate; 7-Guide plate; 8-Discharge plate; 11-Flue inlet hole; 12-Flue outlet hole; 13-Detection hole; 14-Negative pressure hole; 15-Transition hole; 21-First connecting hole; 51-First connecting plate; 52-Second connecting plate; 53-Connecting pipe; 54-First connecting hole; 55-Second connecting hole; 56-Through hole; 57-Second connecting hole. Detailed Implementation

[0021] The above-mentioned and other technical features and advantages of this utility model will be described in more detail below with reference to the accompanying drawings.

[0022] Example 1

[0023] like Figure 1 As shown, Figure 1 This is a structural view of the sampling device used for rapid NOx measurement.

[0024] The sampling device for rapid NOx measurement according to this utility model includes a connecting part 5 and a detection part. The detection part is fixedly mounted on the flue 2 via the connecting part 5. The detection part includes a detection block 1, which is provided with a smoke inlet 11, a smoke outlet 12, a detection hole 13, and a negative pressure hole 14. One end of the smoke inlet 11 and the smoke outlet 12 are both connected to the inside of the flue 2. One end of the smoke inlet 11 is connected to the smoke outlet 12 via a transition hole 15. The other end of the smoke outlet 12 is connected to the negative pressure hole 14. The detection hole 13 is connected to the smoke outlet 12. 2 is coaxially arranged with the negative pressure hole 14. The negative pressure hole 14 is provided with a nozzle 3. The nozzle 3 axially sprays heated compressed air into the smoke outlet hole 12, thereby creating a negative pressure in the smoke outlet hole 12, so that the flue gas in the flue 2 enters the smoke outlet hole 12 through the smoke inlet hole 11. The detection hole 13 is connected to a sensor 4. The detection head of the sensor 4 is set in the smoke outlet hole 12. When the flue gas in the flue 2 enters the smoke outlet hole 12, the sensor 4 detects the NOx concentration of the flue gas in the smoke outlet hole 12, thereby determining the NOx concentration in the flue 2.

[0025] Preferably, the axes of the smoke inlet 11 and the smoke outlet 12 are arranged parallel to each other, and the axes of the smoke inlet 11 and the smoke outlet 12 are arranged perpendicular to the extension direction of the flue 2. This avoids the flue gas from the flue 2 from directly entering the smoke inlet 11 and the smoke outlet 12 in a flowing state, which would cause inaccurate detection. Generally, the smoke inlet 11 and the smoke outlet 12 are symmetrically arranged about the axis of the detection block 1, which also facilitates providing better installation space for the detection hole 13, the negative pressure hole 14, and the transition hole 15.

[0026] Generally, the axis of the transition hole 15 is perpendicular to the axes of the smoke inlet hole 11 and the smoke outlet hole 12, and the detection hole 13 is coaxial with the transition hole 15, so that the sensor 4 can directly detect the smoke concentration of the smoke outlet hole 12 through the transition hole 15, thereby improving the accuracy of detection.

[0027] Generally, the smoke inlet 11 and the smoke outlet 12 are arranged in a straight line along the flow direction of the flue gas in the flue 2 to reduce the disturbance of the flue gas flowing into the smoke inlet 11 by the compressed air discharged from the smoke outlet 12, thus affecting the detection results.

[0028] Preferably, the pressure of the compressed air ejected by the nozzle 3 is set to 0.3MP to 0.5MP to ensure a better negative pressure while minimizing disturbance to the flue gas in the flue 2.

[0029] Both the connecting part 5 and the detection part are made of 304 stainless steel, which can prevent corrosion from flue gas.

[0030] This invention eliminates the sampling structure of the sampling tube and CEMS chamber in the prior art, and can be directly connected to the wall of the flue 2 to sample the flue gas in the flue 2. This avoids the lag in NOx concentration detection data caused by excessive sampling time, and provides a basic guarantee for achieving accurate ammonia injection.

[0031] Meanwhile, since the compressed air ejected through the nozzle 3 forms a negative pressure, blockage in the smoke outlet 12 can be avoided during long-term use, enabling the present invention to be used stably for a long time in high-dust environments.

[0032] Example 2

[0033] like Figure 2 and Figure 3 As shown, Figure 2 This is a front view of the connection structure between the connecting part and the detection part; Figure 3 This is a side view of the connection structure between the connecting part and the detection part.

[0034] The connecting part 5 includes a first connecting plate 51, a second connecting plate 52, and a connecting pipe 53. The connecting pipe 53 is a hollow tubular component. A first communicating hole 21 is provided on the flue 2. The connecting pipe 53 is fixedly installed on the flue 2. The first communicating hole 21 and the connecting pipe 53 are coaxially arranged. One end of the connecting pipe 53 is fixedly connected to the flue 2, and the other end is fixedly provided with the second connecting plate 52. The first connecting plate 51 is fixedly installed on the detection block 1. The first connecting plate 51 and the second connecting plate 52 are detachably connected, thereby realizing the fixation of the detection part on the flue 2 through the connecting part 5.

[0035] Preferably, the first connecting plate 51 is provided with a first connecting hole 54, and the second connecting plate 52 is provided with a second connecting hole 55. The first connecting hole 54 and the second connecting hole 55 are provided in a one-to-one correspondence. The connecting bolt passes through the corresponding first connecting hole 54 and the second connecting hole 55 in sequence and is threadedly connected to the connecting nut, thereby realizing the detachable connection between the first connecting plate 51 and the second connecting plate 52.

[0036] Generally, the first connecting plate 51 is provided with two through holes 56, which correspond to the smoke inlet 11 and the smoke outlet 12, respectively. The through holes 56 are coaxially arranged with the corresponding smoke inlet 11 or smoke outlet 12. A partition plate 6 is vertically arranged on the first connecting plate 51, and the partition plate 6 is disposed between the two through holes 56, thereby preventing the compressed air discharged from the smoke outlet 12 from affecting the smoke flowing into the smoke inlet 11. It is worth noting that a one-way valve can be installed on both through holes 56 to realize the directional flow of air.

[0037] The second connecting plate 52 is provided with a second connecting hole 57. The first connecting hole 21 and the second connecting hole 57 are coaxially arranged, thereby ensuring that the smoke inlet hole 11 and the smoke outlet hole 12 are connected to the flue 2 through the first connecting hole 21 and the second connecting hole 57.

[0038] Preferably, the first connecting hole 21 and the second connecting hole 57 have the same diameter. A guide plate 7 is provided on the side of the partition plate 6 near the smoke outlet 12. The two guide plates 7 are symmetrically arranged on both sides of the smoke outlet 12. One end of the guide plate 7 is fixedly connected to the first connecting plate 51. One side of the guide plate 7 is fixedly connected to the partition plate 6, and the other side has a clearance gap with the inner wall of the first connecting hole 21 and the second connecting hole 57. This facilitates the partition plate 6 and the guide plate 7 extending into the flue 2, further reducing the impact of compressed air on the smoke flowing into the smoke inlet 11. The clearance gap is generally set to 2mm to 5mm to ensure convenient installation while minimizing mutual interference between the smoke inlet 11 and the smoke outlet 12.

[0039] Preferably, a discharge plate 8 is fixedly provided at the end of the partition plate 6 away from the first connecting plate 51. The discharge plate 8 extends downward at an angle away from the first connecting plate 51. Similarly, the guide plate 7 is also inclined, so that after the dust accumulates on the partition plate 6, it is pushed onto the discharge plate 8 by compressed air and slides down under its own gravity, avoiding blockage on the partition plate 6.

[0040] Gaskets are provided at the connection points of the nozzle 3 and the negative pressure hole 14, the connection points of the sensor 4 and the detection hole 13, and between the first connecting plate 51 and the second connecting plate 52, so as to ensure the sealing at the connection points.

[0041] The above description is merely a preferred embodiment of the present utility model and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present utility model, all of which will fall within the protection scope of the present utility model.

Claims

1. A sampling device for rapid NOx measurement, characterized in that, The device includes a connecting part and a detection part. The detection part is fixedly mounted on the flue via the connecting part. The detection part includes a detection block, which has a smoke inlet, a smoke outlet, a detection hole, and a negative pressure hole. One end of the smoke inlet and the smoke outlet are both connected to the inside of the flue. One end of the smoke inlet is connected to the smoke outlet through a transition hole, and the other end of the smoke outlet is connected to the negative pressure hole. The detection hole is connected to the smoke outlet and is coaxially arranged with the smoke outlet and the negative pressure hole. A nozzle is provided on the negative pressure hole to axially spray compressed air into the smoke outlet. A sensor is connected to the detection hole, and the detection head of the sensor is located inside the smoke outlet.

2. The sampling device for rapid NOx measurement as described in claim 1, characterized in that, The axes of the smoke inlet and the smoke outlet are arranged parallel to each other, and the axes of the smoke inlet and the smoke outlet are arranged perpendicular to the extension direction of the flue.

3. The sampling device for rapid NOx measurement as described in claim 2, characterized in that, The axis of the transition hole is perpendicular to the axes of the smoke inlet and the smoke outlet, and the detection hole is coaxial with the transition hole.

4. The sampling device for rapid NOx measurement as described in claim 3, characterized in that, The smoke inlet and the smoke outlet are arranged sequentially in a straight line along the direction of the flue gas flow.

5. The sampling device for rapid NOx measurement as described in claim 1, characterized in that, The connecting part includes a first connecting plate, a second connecting plate, and a connecting pipe. The connecting pipe is a hollow tubular component. A first communicating hole is provided on the flue. The connecting pipe is fixedly installed on the flue. The first communicating hole and the connecting pipe are coaxially arranged. One end of the connecting pipe is fixedly connected to the flue, and the other end is fixedly provided with the second connecting plate. The first connecting plate is fixedly installed on the detection block. The first connecting plate and the second connecting plate are detachably connected.

6. The sampling device for rapid NOx measurement as described in claim 5, characterized in that, The first connecting plate is provided with a first connecting hole, and the second connecting plate is provided with a second connecting hole. The first connecting hole and the second connecting hole are provided in a one-to-one correspondence. The connecting bolt passes through the corresponding first connecting hole and the second connecting hole in sequence and is threadedly connected to the connecting nut.

7. The sampling device for rapid NOx measurement as described in claim 5, characterized in that, The first connecting plate is provided with two through holes, which correspond to the smoke inlet and the smoke outlet respectively. The through holes are coaxially arranged with the corresponding smoke inlet or smoke outlet. A partition plate is vertically arranged on the first connecting plate, and the partition plate is arranged between the two through holes.

8. The sampling device for rapid NOx measurement as described in claim 7, characterized in that, The second connecting plate is provided with a second connecting hole, and the first connecting hole and the second connecting hole are coaxially arranged.

9. The sampling device for rapid NOx measurement as described in claim 8, characterized in that, The first connecting hole and the second connecting hole have the same diameter. A guide plate is provided on the side of the partition plate near the smoke outlet. The two guide plates are symmetrically arranged on both sides of the smoke outlet. One end of the guide plate is fixedly connected to the first connecting plate. One side of the guide plate is fixedly connected to the partition plate. The other side is provided with a clearance gap with the inner wall of the first connecting hole and the second connecting hole.

10. The sampling device for rapid NOx measurement as described in claim 9, characterized in that, A material drop plate is fixedly provided at the end of the partition plate away from the first connecting plate, and the material drop plate extends downward at an angle away from the first connecting plate.

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