A device for multi-point sampling of flue gas in an SCR

Abstract

The utility model relates to the technical field of SCR flue gas sampling, and disclose a kind of SCR flue gas multipoint sampling device.The device carries out multipoint sampling by multiple sampling components to the flue gas in denitration flue, and is gathered into sampling main pipe, finally is transported to the confluence pool, and then enters CEMS analyzer for component analysis by pipeline, then, control box receives CEMS analyzer, to improve the representativeness and analysis accuracy of sampling.

Description

Technical Field

[0001] This utility model relates to the field of SCR flue gas sampling technology, and in particular to a multi-point sampling device for SCR flue gas. Background Technology

[0002] SCR denitrification technology refers to a NOx emission reduction technology in which a reducing agent, under the action of a catalyst, selectively reacts with NOx in flue gas within the range of 280 to 420℃ to generate pollution-free N2 and H2O.

[0003] Chinese Patent Publication No. CN216247410U discloses a multi-point sampling and leak detection / unblocking device for SCR flue gas, including a gas source and a sampling and detection unit. The sampling and detection unit includes a sampling main pipe, sampling branch pipes, a flue gas mixing sampling pool, and a flue gas sampling and detection component. The gas source is connected to the first end of the sampling main pipe. A first valve is provided on the pipeline between the first end of the sampling main pipe and the gas source to control the connection between the sampling main pipe and the gas source. The second end of the sampling main pipe is connected to the flue gas mixing sampling pool, and a second valve is provided on the pipeline between the second end of the sampling main pipe and the flue gas mixing sampling pool to control the connection between the two. One end of the sampling branch pipe extends into the flue, and the other end is connected to the sampling main pipe, with a third valve on it. The flue gas mixing sampling pool is connected to the dust collector inlet and the flue gas sampling and detection component. Therefore, the flue gas is mixed more uniformly, the cross-sectional representation is stronger, and the presence of leaks or blockages in the sampling branch pipes and sampling main pipe can be identified in a timely manner for inspection and backflushing to clear blockages.

[0004] Regarding the aforementioned and existing related technologies, the inventors believe that the following shortcomings often exist: The CEMS measuring points used in existing denitrification systems employ a single-point sampling complete extraction method, and the accompanying analyzer is the Shanghai Huachuan M6900 model. Because single-point sampling can only collect flue gas samples from a specific location within the flue, it cannot cover the flue gas distribution in different areas within the flue. This results in limitations in the obtained NOx concentration measurement data, which cannot accurately and comprehensively reflect the overall NOx concentration level within the flue, and the measurement data is not representative. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the existing technology has the disadvantage of insufficient representativeness of single-point sampling. To this end, we propose an SCR flue gas multi-point sampling device.

[0006] To achieve the above objectives, this application adopts the following technical solution: an SCR flue gas multi-point sampling device, comprising: a manifold, a denitrification flue, and a control box. One side of the manifold is connected to a sampling header pipe via a flange. The end of the sampling header pipe away from the manifold extends to the outside of the denitrification flue. The outer surface of the sampling header pipe is connected to sampling components. Multiple sets of sampling components are evenly arranged along the length of the outer surface of the sampling header pipe, and each set of sampling components penetrates the side wall of the denitrification flue and extends into its interior. The outer surface of the sampling header pipe is also connected to a backflushing component. The outlet of the manifold is connected to a CEMS analyzer via a pipeline. A sampling pump is connected in series at the inlet end of the CEMS analyzer. The CEMS analyzer is electrically connected to the control box. Preferably, the sampling assembly includes a fixed bracket fixedly installed inside the denitrification flue, and sampling branch pipes spaced apart on the upper surface of the fixed bracket. One end of the sampling branch pipe penetrates the side wall of the denitrification flue and is connected to the flange of the sampling main pipe. The other end of the sampling branch pipe extends into the interior of the denitrification flue and is equipped with an anti-clogging sampling head at its end. A flow meter and an electric regulating valve are sequentially arranged on the outer surface of the sampling branch pipe along the airflow direction. The flow meter and the electric regulating valve are electrically connected to the control box, which improves the representativeness of the sampling and the accuracy of the analysis.

[0007] Preferably, the interior of the denitrification flue is divided into several detection zones along the flue gas flow direction, and a negative pressure zone is formed between two adjacent detection zones. The layout area of ​​the multiple sets of sampling branches covers all detection zones and negative pressure zones, so that the detection results can truly reflect the overall effect of SCR denitrification.

[0008] Preferably, both the sampling branch pipe and the sampling main pipe are corrosion-resistant components made of polytetrafluoroethylene, which improves the stability of the pipeline.

[0009] Preferably, the backflushing assembly includes a main control cabinet, a triplet and a backflushing control module connected to the outer surface of the main control cabinet via wires. One end of the sampling main pipe is provided with a compressed air pipeline, and one end of the compressed air pipeline is connected to a compressed air source. The outer surface of each set of sampling branch pipes is provided with a solenoid valve, and each set of solenoid valves is electrically connected to the main control cabinet to remove accumulated dust and particulate matter in the sampling main pipe and sampling branch pipes.

[0010] Preferably, the outer surface of the sampling main pipe is also provided with a primary hot air tracing pipe, the input end of which is connected to a hot air source. The outer surface of the main control cabinet is connected to a temperature warning module via wires. The outer surface of each group of sampling branch pipes is provided with a temperature sensor, and each group of temperature sensors is electrically connected to the main control cabinet to prevent flue gas from condensing in the pipeline.

[0011] Preferably, the control box integrates a data processing module, which is connected to a DCS remote control system for easy adjustment.

[0012] The technical effects and advantages of this utility model are as follows: In this invention, the device samples the flue gas in the denitrification flue at multiple points through multiple sets of sampling components, collects the samples into the sampling header, and finally delivers them to the manifold. The samples then enter the CEMS analyzer through pipelines for component analysis. Subsequently, the control box receives the samples from the CEMS analyzer, thereby improving the representativeness of the sampling and the accuracy of the analysis. Attached Figure Description

[0013] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the SCR flue gas multi-point sampling structure of this utility model; Figure 2 This is a partial structural schematic diagram of the present invention; Figure 3 This is a schematic diagram of the backflush assembly structure of this utility model.

[0014] Legend: 1. Manifold; 2. Denitrification flue; 21. Detection area; 22. Negative pressure area; 3. Control box; 4. Sampling main pipe; 5. Sampling assembly; 51. Fixed bracket; 52. Sampling branch pipe; 53. Flow meter; 54. Electric regulating gate; 6. Backflush assembly; 61. Main control cabinet; 62. Tri-unit; 63. Backflush control module; 64. Compressed air pipeline; 65. Compressed air source; 66. Solenoid valve; 7. CEMS analyzer; 8. Primary hot air tracing pipe; 81. Hot air source; 82. Temperature warning module; 83. Temperature sensor. Detailed Implementation

[0015] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0016] Reference Figure 1As shown, this utility model provides a technical solution: a multi-point sampling device for SCR flue gas, including: a manifold 1, a denitrification flue 2, and a control box 3. One side of the manifold 1 is connected to a sampling header 4 via a flange. The end of the sampling header 4 away from the manifold 1 extends to the outside of the denitrification flue 2. The outer surface of the sampling header 4 is connected to sampling components 5. Multiple sets of sampling components 5 are evenly arranged along the length of the outer surface of the sampling header 4, and each set of sampling components 5 penetrates the side wall of the denitrification flue 2 and extends into its interior. The outer surface of the sampling header 4 is also connected to a backflushing component 6. The outlet of the manifold 1 is connected to a CEMS analyzer 7 via a pipeline. A sampling pump is connected in series at the inlet end of the CEMS analyzer 7. The CEMS analyzer 7 is electrically connected to the control box 3. The flue gas in the denitrification flue 2 enters the sampling header 4 through multiple sets of sampling components 5, is collected and transported to the manifold 1, and then enters the CEMS analyzer 7 through a pipeline for component analysis.

[0017] Reference Figures 1-3 As shown in this embodiment: the sampling assembly 5 includes a fixed bracket 51 fixedly installed inside the denitrification flue 2, and sampling branch pipes 52 spaced apart on the upper surface of the fixed bracket 51. One end of the sampling branch pipe 52 penetrates the side wall of the denitrification flue 2, and one end of the sampling branch pipe 52 is connected to the flange of the sampling main pipe 4. The other end of the sampling branch pipe 52 extends into the interior of the denitrification flue 2 and is provided with an anti-clogging sampling head at the end. A flow meter 53 and an electric regulating gate are sequentially arranged on the outer surface of the sampling branch pipe 52 along the airflow direction. 54. Flow meter 53 and electric regulating gate 54 are electrically connected to control box 3 respectively. Fixed bracket 51 is used to support sampling branch pipe 52 to ensure its installation stability in denitrification flue 2. When flue gas enters sampling branch pipe 52 through anti-clogging sampling head, flow meter 53 monitors flue gas flow in sampling branch pipe 52 in real time and adjusts the flow through electric regulating gate 54 according to the command of control box 3 to make the flue gas flow of each sampling branch pipe 52 equal and finally merge into sampling main pipe 4, which improves the representativeness of sampling and the accuracy of analysis.

[0018] The interior of the denitrification flue 2 is divided into several detection zones 21 along the flue gas flow direction. A negative pressure zone 22 is formed between two adjacent detection zones 21. The layout area of ​​multiple sampling branch pipes 52 covers all detection zones 21 and negative pressure zones 22. Through zoned coverage sampling, the concentration field and flow field changes of flue gas in the denitrification flue 2 are completely captured, so that the detection results can truly reflect the overall effect of SCR denitrification and provide more reliable data support for the optimization of the denitrification system.

[0019] Both the sampling branch pipe 52 and the sampling main pipe 4 are corrosion-resistant components made of polytetrafluoroethylene (PTFE). By utilizing the corrosion resistance and high temperature resistance of PTFE, they can adapt to the strong corrosiveness and high temperature environment of SCR flue gas, ensuring the long-term stable operation of the pipeline.

[0020] The backflush assembly 6 includes a main control cabinet 61, a triplet 62 connected to the outer surface of the main control cabinet 61 by wires, and a backflush control module 63. One end of the sampling main pipe 4 is provided with a compressed air pipeline 64, and one end of the compressed air pipeline 64 is connected to a compressed air source 65. The outer surface of each sampling branch pipe 52 is provided with a solenoid valve 66, and each solenoid valve 66 is electrically connected to the main control cabinet 61 to remove the accumulated dust and particulate matter in the sampling main pipe 4 and the sampling branch pipe 52.

[0021] The outer surface of the sampling main pipe 4 is also equipped with a primary hot air tracing pipe 8. The input end of the primary hot air tracing pipe 8 is connected to a hot air source 81. The outer surface of the main control cabinet 61 is connected to a temperature warning module 82 via wires. The outer surface of each sampling branch pipe 52 is equipped with a temperature sensor 83. Each temperature sensor 83 is electrically connected to the main control cabinet 61 to provide heat tracing and insulation for the sampling main pipe 4 and the sampling branch pipe 52. The temperature sensor 83 monitors the pipeline temperature in real time and, in conjunction with the temperature warning module 82, issues an alarm when the temperature is abnormal. This allows the main control cabinet 61 to adjust the heat tracing intensity according to the temperature signal to prevent condensation of flue gas in the pipeline.

[0022] The control box 3 integrates a data processing module, which is connected to the DCS remote control system. The data processing module receives detection data from the flow meter 53, temperature sensor 83, and CEMS analyzer 7. After integrating and analyzing the multi-point sampling data, it feeds it back to the denitrification control system, providing a data basis for precise ammonia injection. At the same time, it realizes remote monitoring and parameter adjustment through the DCS remote control system.

[0023] Working principle: The interior of the denitrification flue duct 2 is divided into several detection zones 21 along the flue gas flow direction. A negative pressure zone 22 is formed between two adjacent detection zones 21. Multiple sampling branch pipes 52 are installed via fixed supports 51, and their coverage area encompasses all detection zones 21 and negative pressure zones 22. Therefore, through zoned coverage sampling, the concentration field and flow field changes of the flue gas within the denitrification flue duct 2 are fully captured, ensuring that the detection results accurately reflect the overall effect of SCR denitrification and providing more reliable data support for denitrification system optimization. Next, when the flue gas enters the sampling branch pipe 52 through the anti-clogging sampling head, the flow meter 53 monitors the flue gas flow rate of the sampling branch pipe 52 in real time and adjusts the flow rate via the electric regulating gate 54 according to the instructions of the control box 3, ensuring a balanced flue gas flow rate in each sampling branch pipe 52. Finally, the flue gas flows into the sampling main pipe 4, improving the representativeness of the sampling and the accuracy of the analysis. Furthermore, since both sampling branch pipe 52 and sampling main pipe 4 are corrosion-resistant components made of polytetrafluoroethylene (PTFE), the corrosion resistance and high-temperature resistance of PTFE can adapt to the highly corrosive and high-temperature environment of SCR flue gas, ensuring long-term stable operation of the pipeline. Simultaneously, hot air source 81 is input through primary hot air tracing pipe 8 to heat and insulate sampling main pipe 4 and sampling branch pipe 52. Multiple temperature sensors 83 monitor the pipeline temperature in real time, and combined with the temperature warning module 82, an alarm is issued when the temperature is abnormal. This allows the main control cabinet 61 to adjust the heat tracing intensity based on the temperature signal, preventing condensation of flue gas within the pipeline. In addition, the main control cabinet 61 periodically starts the compressed air source 65 by controlling solenoid valve 66. Compressed air enters sampling main pipe 4 and sampling branch pipe 52 through compressed air pipeline 64 to remove internal dust and particulate matter, preventing pipeline blockage. Finally, the mixed flue gas in the sampling header 4 is collected into the manifold 1 and transported to the CEMS analyzer 7 by the sampling pump. The CEMS analyzer 7 detects the flue gas composition and, in conjunction with the data processing module, integrates and analyzes the multi-point sampling data before feeding it back to the denitrification control system, providing a data basis for precise ammonia injection. At the same time, remote monitoring and parameter adjustment are realized through the DCS remote control system.

[0024] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A multi-point sampling device for SCR flue gas, characterized in that: The system includes a manifold, a denitrification flue, and a control box. One side of the manifold is connected to a sampling header via a flange. The end of the sampling header away from the manifold extends to the outside of the denitrification flue. Sampling components are connected to the outer surface of the sampling header. Multiple sets of sampling components are evenly arranged along the length of the outer surface of the sampling header, and each set of sampling components penetrates the side wall of the denitrification flue and extends into its interior. Backflushing components are also connected to the outer surface of the sampling header. The outlet of the manifold is connected to a CEMS analyzer via a pipeline. A sampling pump is connected in series at the inlet end of the CEMS analyzer. The CEMS analyzer is electrically connected to the control box.

2. The SCR flue gas multi-point sampling device according to claim 1, characterized in that: The sampling assembly includes a fixed bracket installed inside the denitrification flue and sampling branch pipes spaced apart on the upper surface of the fixed bracket. One end of the sampling branch pipe penetrates the side wall of the denitrification flue and is connected to the sampling main pipe flange. The other end of the sampling branch pipe extends into the interior of the denitrification flue and is equipped with an anti-clogging sampling head. A flow meter and an electric regulating valve are sequentially arranged on the outer surface of the sampling branch pipe along the airflow direction. The flow meter and the electric regulating valve are electrically connected to the control box.

3. The SCR flue gas multi-point sampling device according to claim 2, characterized in that: The interior of the denitrification flue is divided into several detection zones along the flue gas flow direction. A negative pressure zone is formed between two adjacent detection zones. The layout area of ​​multiple sets of sampling branch pipes covers all detection zones and negative pressure zones.

4. The SCR flue gas multi-point sampling device according to claim 2, characterized in that: Both the sampling branch pipe and the sampling main pipe are corrosion-resistant components made of polytetrafluoroethylene.

5. The SCR flue gas multi-point sampling device according to claim 2, characterized in that: The backflush assembly includes a main control cabinet, a triplet and a backflush control module connected to the outer surface of the main control cabinet by wires. One end of the sampling main pipe is provided with a compressed air pipeline, and one end of the compressed air pipeline is connected to a compressed air source. The outer surface of each set of sampling branch pipes is provided with a solenoid valve, and each set of solenoid valves is electrically connected to the control box.

6. The SCR flue gas multi-point sampling device according to claim 5, characterized in that: The outer surface of the sampling main tube is also provided with a primary hot air tracing pipe. The input end of the primary hot air tracing pipe is connected to a hot air source. The outer surface of the main control cabinet is connected to a temperature warning module via wires. The outer surface of each group of sampling branch tubes is provided with a temperature sensor. Each group of temperature sensors is electrically connected to the control box.

7. The SCR flue gas multi-point sampling device according to claim 1, characterized in that: The control box integrates a data processing module, which is connected to the DCS remote control system.

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