Ammonia escape monitoring system based on flue partition

Abstract

The invention discloses an ammonia escape monitoring system based on flue partitions, which comprises a plurality of sampling structures, and the sampling structures penetrate into a flue and are located in different partitions of the flue; the outer end of the sampling structure is communicated and connected with a sampling outer pipe, the sampling outer pipe is communicated and connected with a mixing box, the mixing box is communicated and connected with a negative pressure generator, and the gas outlet end of the negative pressure generator penetrates through the outer wall of the flue and enters the inner cavity of the flue; the negative pressure generator is further connected with a first high-pressure air pipe. The mixing box is communicated and connected with an ammonia monitoring instrument and a nitrogen monitoring instrument. The scheme has the beneficial effects that according to the description of the scheme, gas is sampled in different partitions of the flue, and is measured after being mixed, so that the problem of data representativeness generated by adopting single-point extraction in the prior art is solved; the sampling nozzle carries out one-time dust filtration, the sampling disc carries out one-time dust filtration again, the problem that the influence of smoke dust in detected gas is large is solved through at least two-time dust filtration, and therefore measurement is more accurate.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to an ammonia escape monitoring system based on flue zoning. Background Art

[0002] At present, large power plants generally use SCR denitrification devices to reduce NO in flue gas. x Emission concentration. SCR uses NH3 to x The reduction characteristics of NO x It is reduced to N2 and H2O which are harmless to the environment. In the actual operation process, the control of ammonia injection amount is particularly critical. Increasing the amount of ammonia injection is conducive to reducing NO x The emission concentration will be increased, but the ammonia escape rate will increase accordingly, which will cause the downstream air preheater to be blocked and corroded due to the deposition of ammonium bisulfate. The accurate monitoring and evaluation of the ammonia escape rate at the denitrification outlet is the key feedback signal for the control of the ammonia injection amount. In the existing technology, NO x Measuring equipment and ammonia escape measuring equipment are used to monitor and evaluate the ammonia escape rate.

[0003] However, the traditional ammonia escape online monitoring device adopts a single-point laser beam measurement method, which has inherent defects such as inaccurate light and excessive smoke and dust influence; x The monitoring adopts single-point extraction and heating measurement. The detected data is poorly representative and cannot provide real and reliable data support for the control system. There are hidden dangers such as untimely ammonia injection, environmental protection data exceeding the standard, and excessive ammonia injection clogging the air preheater. Summary of the invention

[0004] The present invention aims at the deficiencies in the prior art and provides an ammonia escape monitoring system based on flue zoning. Gas is sampled in different flue zones and mixed before measurement, thereby solving the problem of data representativeness previously produced by single-point extraction. The sampling nozzle performs dust filtration once, and the sampling disc performs dust filtration again. At least two dust filtrations solve the problem of the significant influence of smoke on the detected gas, thereby making the measurement more accurate.

[0005] In order to achieve the above object, the present invention provides an ammonia escape monitoring system based on flue partitioning, comprising a plurality of sampling structures, the sampling structures penetrate into the flue, and the sampling structures are located in different partitions of the flue; The outer end of the sampling structure is connected to a sampling outer tube, the sampling outer tube is connected to a mixing box, the mixing box is connected to a negative pressure generator, and the air outlet end of the negative pressure generator passes through the outer wall of the flue and enters the inner cavity of the flue; The negative pressure generator is also connected to a high pressure air pipe 1; The mixing box is connected to an ammonia monitoring instrument and a nitrogen monitoring instrument.

[0006] Further, the sampling structure includes a mounting cylinder, the mounting cylinder passes through the outer wall of the flue and the outer diameter is sealed and connected to the outer wall of the flue; The outer end of the mounting cylinder is fixedly connected with a sampling disc, the sampling disc is connected with a sampling rod, and the sampling rod passes through the mounting cylinder and enters the flue cavity; The sampling rod is provided with a sampling nozzle, and the opening of the sampling nozzle faces away from the direction of the flue gas flow; The sampling disc is connected to a ball valve 1, the ball valve 1 is connected to a flexible joint structure 1, and the flexible joint structure 1 is connected to the sampling outer tube.

[0007] Furthermore, the sampling disc comprises a ring, the two sides of the ring are respectively connected with an outer wall and an inner wall, the inner wall is connected with a threaded flange, and the threaded flange is threadedly connected to the sampling rod; The outer side wall is provided with a cleaning port, and the cleaning port is connected to a sampling cover; A dust filter is arranged between the outer wall and the inner wall, and the dust filter is annular.

[0008] Furthermore, the first articulation structure includes an articulation seat, the upper end of which is fixedly connected to the sampling outer tube, the lower end of which is threadedly connected to a connector, and a micro-negative pressure instrument seat is provided on the side of the articulation seat and connected to a micro-negative pressure instrument; The other end of the connector is threadedly connected to the ball valve 1.

[0009] Furthermore, the sampling outer tube comprises a first section, a transition section 1, a horizontal section, a transition section 2 and a tail end which are connected in sequence, the first section is arranged vertically, and the lower end of the first section is connected to the sampling structure; The horizontal section is in close contact with the outer wall of the flue; The tail end is connected to the mixing box.

[0010] Furthermore, the mixing box is installed on the outer wall of the flue, a through hole is opened on the outer wall of the flue, and the inner side of the mixing box is embedded in the inner cavity of the flue.

[0011] Furthermore, the high-pressure gas pipe 1 is connected to a high-pressure gas buffer box, the high-pressure gas buffer box is connected to a high-pressure gas pipe 2, and the high-pressure gas pipe 2 is connected to a total high-pressure gas source.

[0012] Furthermore, the high-pressure gas pipe 1 includes an air inlet section, a main body section and an air outlet section, the air inlet section and the air outlet section are located outside the flue, and the main body section is located inside the flue; The air outlet section is connected to the high-pressure air buffer box, and the air outlet section is connected to the negative pressure generator; The body section is provided with a plurality of S-shaped bends.

[0013] Furthermore, the high-pressure air pipe 1 is connected to a movable joint structure 2 and a ball valve 2 near the negative pressure generator, and the movable joint structure 2 is connected to a positive pressure gauge.

[0014] Furthermore, a plurality of sampling structures are respectively arranged on the left and right sides of the mixing box.

[0015] The beneficial effects of this solution can be known from the description of the above solution. Compared with the prior art, it has the following beneficial effects: (1) Gas is sampled from different sections of the flue and mixed before measurement, thus solving the problem of data representativeness previously generated by single-point sampling; (2) The sampling nozzle is filtered once, and the sampling disc is filtered again. The dust filtering at least twice solves the problem of the smoke and dust of the detected gas, so that the measurement is more accurate. (3) The horizontal section of the outer sampling tube is close to the outer wall of the flue, and the inner wall of the mixing box is embedded in the inner cavity of the flue, so that the detected gas is kept as warm as possible to ensure the accuracy of the test results; (4) The main body of the heating high-pressure gas pipe is located in the flue cavity and is provided with an S-shaped bend to heat the high-pressure gas as much as possible, thereby reducing the temperature difference between the detected gas and the high-pressure gas obtained by the negative pressure generator, so that the negative pressure generator is heated as evenly as possible; (5) The sampling outer tube is connected in series with a union structure 1 and a ball valve 1, and the union structure 1 is connected with a micro-negative pressure instrument, so as to control the gas supply ratio of each sampling outer tube to the mixing box; (6) The structure of the sampling disc makes it easier to clean the dust filter and the smoke inside the sampling rod. It is very convenient to manually remove the dust or replace the dust filter. It is also very convenient to apply high-pressure gas directly to the outer end of the sampling rod and blow the sampling nozzle in the opposite direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 for Figure 1 A top view of Figure 3 It is a schematic diagram of the installation structure of the sampling structure of the present invention; Figure 4 for Figure 3 A magnified view of part I; Figure 5 for Figure 1 A magnified view of part I; Figure 6 FIG. 1 is a schematic diagram of the structure of the sampling outer tube of the present invention; Figure 7 FIG. 1 is a schematic structural diagram of a high pressure gas pipe according to the present invention.

[0017] In the figure, 1, installation cylinder; 2, flue outer wall; 3, sampling disc; 3-1, ring; 3-2, outer wall; 3-3, inner wall; 3-4, cleaning port; 4, threaded flange; 5, sampling rod; 5-1, sampling nozzle; 6, sampling cover; 7, dust filter; 8, ball valve 1; 9, joint structure 1; 9-1, joint seat; 9-2, connector; 9-3, micro-negative pressure instrument seat; 10, micro-negative pressure instrument 10; 11, sampling outer tube ; 11-1, first section; 11-2, transition section one; 11-3, horizontal section; 11-4, transition section two; 11-5,; 12, mixing box; 13, negative pressure generator; 14, ammonia monitoring instrument; 15, nitrogen monitoring instrument; 16, high-pressure gas pipe one; 16-1, air inlet section; 16-2, main body section; 16-3, air outlet section; 17, high-pressure gas buffer box; 18, flexible joint structure two; 19, ball valve two; 20, positive air pressure gauge. DETAILED DESCRIPTION

[0018] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0019] like Figure 1 , 2 As shown, this embodiment is an ammonia escape monitoring system based on flue zoning, including a sampling structure, such as Figure 3 , 4 As shown, the sampling structure includes a mounting cylinder 1, which passes through the outer wall 2 of the flue and is sealed with the outer wall 2 of the flue on its outer diameter; a sampling disc 3 is fixedly connected to the outer end of the mounting cylinder 1, and the sampling disc 3 includes a ring 3-1, and the two sides of the ring 3-1 are respectively connected to the outer wall 3-2 and the inner wall 3-3, and the inner wall 3-3 is connected to a threaded flange 4, and the threaded flange 4 is threadedly connected to a sampling rod 5, and the sampling rod 5 passes through the mounting cylinder 1 and enters the inner cavity of the flue, and the sampling rod 5 is provided with a sampling nozzle 5-1, and the opening of the sampling nozzle 5-1 is away from the direction of the flue airflow.

[0020] The outer wall 3-2 is provided with a cleaning port 3-4, and the cleaning port 3-4 is connected to the sampling cover 6; a dust filter 7 is provided between the outer wall 3-2 and the inner wall 3-3, and the dust filter 7 is annular.

[0021] A supporting structure is provided in the flue for supporting the sampling rod 5, and the sampling rod 5 is installed horizontally.

[0022] like Figure 5 As shown, the sampling disc 3 is connected with a ball valve 8 on the top, and the ball valve 8 is connected with a flexible joint structure 9, which includes a flexible joint seat 9-1, and a connector 9-2 is threadedly connected to the lower end of the flexible joint seat 9-1, and the other end of the connector 9-2 is threadedly connected to the ball valve 8; a micro-negative pressure instrument seat 9-3 is provided on the side of the flexible joint seat 9-1 and is connected to a micro-negative pressure instrument 10; the upper end of the flexible joint seat 9-1 is fixedly connected to a sampling outer tube 11.

[0023] like Figure 6 As shown, the sampling outer tube 11 includes a first section 11-1, a transition section 11-2, a horizontal section 11-3, a transition section 2 11-4 and a tail end 11-5 which are connected in sequence. The first section 11-1 is arranged vertically, and the lower end of the first section 11-1 is connected to the sampling structure; the horizontal section 11-3 is close to the outer wall 2 of the flue; and the tail end 11-5 is connected to the mixing box 12.

[0024] like Figure 2 As shown, the mixing box 12 is installed on the outer wall 2 of the flue, and the outer wall 2 of the flue is provided with a through hole, and the inner side of the mixing box 12 is embedded in the inner cavity of the flue. A space of 200 mm is reserved around the mixing box 12 and between the reinforcing ribs to facilitate welding of the mixing box 12.

[0025] There are four sets of sampling structures connected to the left and right sides of the mixing box 12, and the four sampling rods 5 on both sides of the mixing box 12 are at the same distance, that is, the sampling points are at equal distances. There is no reinforcement rib within 200mm around the edge of the installation cylinder 1, and the sampling cover 6 is not interfered by the reinforcement rib when it is installed.

[0026] The sampling outer tube 11 is a φ16×2 type tube made of 304# steel. According to the corresponding relationship between the smoke inlet of the mixing box 12 and the smoke outlet of the sampling rod 5, the sampling outer tube 11 is bent into a corresponding shape with a pipe bender, and then one end of the sampling outer tube 11 is spot welded to the joint structure 9 and removed together, and then the sampling outer tube 11 is fully welded to the joint seat 9-1. After annealing, the copper gaskets of the joint structure 9 and the micro-negative pressure instrument 10 are installed in the corresponding position, and the connector 9-2 is tightened.

[0027] Pipeline welding must be done with argon arc welding; when forming the sampling outer tube 11, the principle of the far-end sampling outer tube 11 being on top should be followed to avoid pipeline crossing and affecting the appearance; when the pipeline is in place, the outlet of the sampling disc 3 should be kept coaxial with the joint structure 19 to ensure that no leakage occurs when the connector 9-2 is tightened; the connection between the sampling outer tube 11 and the mixing box 12 should be fully welded.

[0028] The mixing box 12 is connected to a negative pressure generator 13 , and the gas outlet end of the negative pressure generator 13 passes through the flue outer wall 2 into the flue inner cavity; the mixing box 12 is connected to an ammonia monitoring instrument 14 and a nitrogen monitoring instrument 15 .

[0029] The negative pressure generator 13 is also connected to a high pressure gas pipe 16, which is connected to a high pressure gas buffer box 17, which is connected to a high pressure gas pipe 2, which is connected to a total high pressure gas source. The high pressure gas pipe 16 is a φ20×2 type pipe.

[0030] like Figure 7As shown, the high-pressure gas pipe 16 includes an air inlet section 16-1, a main body section 16-2 and an air outlet section 16-3. The air inlet section 16-1 and the air outlet section 16-3 are located outside the flue, and the main body section 16-2 is located inside the flue; the air outlet section 16-3 is connected to the high-pressure gas buffer box 17, and the air outlet section 16-3 is connected to the negative pressure generator 13; the main body section 16-2 is provided with a plurality of S-shaped bends.

[0031] like Figure 2 As shown, the high-pressure air pipe 16 is connected to a second flexible joint structure 18 and a second ball valve 19 near the negative pressure generator 13 , and the second flexible joint structure 18 is connected to a positive air pressure gauge 20 .

[0032] During operation, the opening degree of the ball valve 19 is controlled by the data of the positive pressure gauge 20, and the high-pressure gas passes through the body section 16-2 to increase the temperature and enter the negative pressure generator 13. Under the suction of the negative pressure generator 13, the flue gas in the flue enters the sampling nozzle 5-1, and reaches the sampling disc 3 through the sampling rod 5, and enters the sampling outer tube 11 after another dust filtration.

[0033] The reading of each micro-negative pressure meter 10 is controlled by a ball valve 8 to adjust the gas flow of each sampling outer tube 11. The flue gas enters the mixing box 12 through the sampling outer tube 11. The ammonia monitoring meter 14 and the nitrogen monitoring meter 15 above the mixing box 12 are tested.

[0034] Then, the mixed flue gas is sucked by the negative pressure generator 13 and then sent into the flue.

[0035] When it is necessary to clean the smoke and dust at both ends of the sampling rod 5, you only need to remove the sampling cover 6 to clean the smoke and dust attached to the dust filter 7, or replace the dust filter. Use a long dry brush to clean the inside of the sampling rod 5. Connecting high-pressure air at the end of the sampling rod 5 can blow away the smoke and dust attached to the outside of the sampling nozzle 5-1.

[0036] Technical features not described in the present invention can be achieved through or by adopting existing technologies and will not be described in detail herein. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. An ammonia escape monitoring system based on flue zoning, characterized in that: It includes a plurality of sampling structures, wherein the sampling structures penetrate into the flue, and the sampling structures are located in different partitions of the flue; The outer end of the sampling structure is connected to a sampling outer tube, the sampling outer tube is connected to a mixing box, the mixing box is connected to a negative pressure generator, and the air outlet end of the negative pressure generator passes through the outer wall of the flue and enters the inner cavity of the flue; The negative pressure generator is also connected to a high pressure air pipe 1; The mixing box is connected to an ammonia monitoring instrument and a nitrogen monitoring instrument.

2. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: The sampling structure includes a mounting cylinder, the mounting cylinder passes through the outer wall of the flue and the outer diameter is sealedly connected to the outer wall of the flue; The outer end of the mounting cylinder is fixedly connected with a sampling disc, the sampling disc is connected with a sampling rod, and the sampling rod passes through the mounting cylinder and enters the flue cavity; The sampling rod is provided with a sampling nozzle, and the opening of the sampling nozzle faces away from the direction of the flue gas flow; The sampling disc is connected to a ball valve 1, the ball valve 1 is connected to a flexible joint structure 1, and the flexible joint structure 1 is connected to the sampling outer tube.

3. The ammonia escape monitoring system based on flue zoning according to claim 2 is characterized in that: The sampling disc comprises a ring, the two sides of the ring are respectively connected with an outer wall and an inner wall, the inner wall is connected with a threaded flange, and the threaded flange is threadedly connected with the sampling rod; The outer side wall is provided with a cleaning port, and the cleaning port is connected to a sampling cover; A dust filter is arranged between the outer wall and the inner wall, and the dust filter is annular.

4. The ammonia escape monitoring system based on flue zoning according to claim 2 is characterized in that: The first articulation structure comprises an articulation seat, the upper end of which is fixedly connected to the sampling outer tube, the lower end of which is threadedly connected to a connector, and a micro-negative pressure instrument seat is provided on the side of the articulation seat and is connected to a micro-negative pressure instrument; The other end of the connector is threadedly connected to the ball valve 1.

5. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: The sampling outer tube comprises a first section, a transition section 1, a horizontal section, a transition section 2 and a tail end which are connected in sequence, the first section is arranged vertically, and the lower end of the first section is connected to the sampling structure; The horizontal section is in close contact with the outer wall of the flue; The tail end is connected to the mixing box.

6. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: The mixing box is installed on the outer wall of the flue, a through hole is opened on the outer wall of the flue, and the inner side of the mixing box is embedded in the inner cavity of the flue.

7. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: The high-pressure gas pipe 1 is connected to a high-pressure gas buffer box, the high-pressure gas buffer box is connected to a high-pressure gas pipe 2, and the high-pressure gas pipe 2 is connected to a total high-pressure gas source.

8. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: The high-pressure gas pipe 1 comprises an air inlet section, a main body section and an air outlet section, wherein the air inlet section and the air outlet section are located outside the flue, and the main body section is located inside the flue; The air outlet section is connected to the high-pressure air buffer box, and the air outlet section is connected to the negative pressure generator; The body section is provided with a plurality of S-shaped bends.

9. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: The high-pressure air pipe 1 is connected to a movable joint structure 2 and a ball valve 2 near the negative pressure generator, and the movable joint structure 2 is connected to a positive pressure gauge.

10. The ammonia escape monitoring system based on flue zoning according to claim 1 is characterized in that: A plurality of sampling structures are respectively arranged on the left and right sides of the mixing box.

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