Sampling system and sampling method

Abstract

The invention relates to a sampling system and a sampling method.The sampling system is used for sampling gas at a plurality of sampling points of a coal pulverizing system, and the sampling system comprises a plurality of sampling probes arranged at the sampling points in a one-to-one correspondence mode; the plurality of probe electromagnetic valves are arranged in one-to-one correspondence with the plurality of sampling probes and are used for adjusting sampling parameters of the sampling probes to preset parameters; the detection part is used for detecting sampling parameters of the sampling probe and controlling opening and closing of the probe electromagnetic valve; and the reverse blowing part is connected with the detection part and is configured to perform blowing operation on the probe electromagnetic valve when the sampling parameter difference value of the sampling probe corresponding to the probe electromagnetic valve is lower than a preset difference value after the probe electromagnetic valve executes the opening and closing actions.

Description

Technical Field

[0001] The present disclosure relates to the technical field of safety monitoring of a milling system, and in particular to a sampling system and a sampling method. Background Art

[0002] Currently, pulverizing systems for large units over 300 MW primarily utilize double-inlet, double-outlet steel ball mills or medium-speed pulverizers. The designed coal type is typically bituminous coal with a volatile matter (Vdaf) of 20%-40%. The system operates at a positive pressure of 5-8 kPa, and the pulverized coal fineness (R90) is controlled within the range of 15%-30% to meet boiler combustion requirements. The pulverizer outlet temperature typically ranges from 60°C to 85°C, depending on the coal type, volatile matter, and equipment type. The traditional pulverizing system usually consists of a coal mill body and air-powder ducts. The medium in the system is a high-speed flowing, high-concentration air-powder mixture. The built-in heating device of the probe in the existing monitoring technology is prone to the risk of coal powder explosion after the heating line ages. It is not safe and reliable enough to achieve comprehensive sampling of the pulverizing system. Relevant statistics show that among 150 coal-fired boilers, about 42% have experienced spontaneous combustion or internal explosion accidents; similarly, another survey of 362 coal-fired boilers showed that on average each boiler had 1.26 fires and 0.31 explosions in the pulverizing system each year. About 22% of the units had such problems, and 18% were in a more serious situation. Summary of the Invention

[0003] The purpose of the present disclosure is to provide a sampling system and a sampling method, which can at least partially solve the technical problems existing in the related art.

[0004] In order to achieve the above objectives, the present disclosure provides a sampling system for sampling gas at multiple sampling points in a pulverizing system, comprising: A plurality of sampling probes are arranged at the plurality of sampling points in a one-to-one correspondence; A plurality of probe solenoid valves are provided corresponding to the plurality of sampling probes one by one, and are used to adjust the sampling parameters of the sampling probes to preset parameters; A detection unit, used to detect the sampling parameters of the sampling probe and control the opening and closing of the probe solenoid valve; The back-flushing part is connected to the detection part and is configured to perform a purge operation on the sampling probe after the probe solenoid valve performs an opening and closing action and when the sampling parameter difference of the sampling probe corresponding to the probe solenoid valve is lower than a preset difference.

[0005] Optionally, it further comprises a plurality of sampling tubes for connecting the plurality of sampling probes to the detection portion respectively, and the plurality of probe solenoid valves are installed on the plurality of sampling tubes in a one-to-one correspondence, wherein the plurality of sampling tubes have the same length.

[0006] Optionally, the detection unit includes a controller, and a flow stabilizer and a parameter sensor connected in sequence downstream of the sampling tube, wherein the parameter sensor is used to detect the flow rate of the sampling gas, and the controller is used to receive the flow signal of the parameter sensor and adjust the opening of the probe solenoid valve and the purge time of the back-blowing unit according to the flow signal.

[0007] Optionally, an exhaust pipe is further included, wherein the exhaust gas inlet of the exhaust gas pipe is connected between the flow stabilizer and the parameter sensor, and the exhaust gas outlet of the exhaust gas pipe is connected to the exhaust gas collecting part.

[0008] Optionally, the sampling system further comprises a filter assembly, which comprises a filter tube connected downstream of the detection portion, and a steam-water separator body, a water removal filter and a condenser which are sequentially connected to and arranged on the filter tube.

[0009] Optionally, the sampling system also includes a drainage assembly for receiving wastewater from the filtering assembly, the drainage assembly including a wastewater collector, a first drain pipe connected between the wastewater collector and the steam-water separator body, and a second drain pipe connected between the water removal filter and the wastewater collector.

[0010] Optionally, the sampling system further comprises an analysis cabinet connected downstream of the filter assembly, and the analysis cabinet is used to analyze the sample gas after dust removal, water removal and filtration.

[0011] Optionally, the pulverizing system includes a coal mill body separator and multiple air-powder ducts, and the sampling points include first sampling points evenly distributed on the peripheral wall of the coal mill body separator, and second sampling points respectively set on the multiple air-powder ducts.

[0012] Optionally, a sampling hole is provided at the sampling point, the opening of the sampling hole protrudes outward from the mounting surface, and the sampling probe is inserted into the opening.

[0013] A second aspect of the present disclosure provides a sampling method for sampling a milling system using the sampling system according to any one of the above items.

[0014] Through the above technical solution, the detection unit monitors the abnormalities of the sampling parameters in real time, and repeatedly controls the probe solenoid valve to perform opening and closing actions to detect abnormalities in the sampling probe and determine whether the sampling probe is blocked. It also controls the backflush unit to blow the blocked sampling probe, thereby clearing and cleaning the sampling probe, thereby achieving comprehensive sampling of the powder making system and improving the accuracy of sampling.

[0015] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 is a schematic diagram of the use principle of the sampling system provided by an exemplary embodiment of the present disclosure; Figure 2-Figure 4 is a schematic diagram of a partial structure of a sampling system provided by an exemplary embodiment of the present disclosure; Figure 5 is a flow chart of a sampling method provided by an exemplary embodiment of the present disclosure.

[0017] Description of Reference Numerals 1-sampling probe; 11-first sampling probe; 12-second sampling probe; 13-coal powder filter; 14-coal powder filter protection component; 21-probe solenoid valve; 22-three-way valve; 3-detection unit; 31-flow stabilizer; 32-parameter sensor; 321-mass flow sensor; 322-pressure sensor; 33-controller; 4-backflush unit; 41-backflush inspection valve; 42-backflush pipe; 5-analysis cabinet; 61-sampling pipe; 611-sampling pipe inspection valve; 62- Exhaust pipe; 63-exhaust throttle valve; 7-filter assembly; 71-filter tube; 72-steam-water separator body; 73-water removal filter; 731-fine filter; 732-precision filter; 74-condenser; 8-drainage assembly; 81-wastewater collector; 82-first drain pipe; 83-second drain pipe; 84-peristaltic pump; 101-pulverizer body separator; 102-air-powder duct; 103-sampling hole; 104-burner; 105-flange; 106-bolt. DETAILED DESCRIPTION

[0018] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0019] In this disclosure, unless otherwise stated, directional terms such as "upstream" and "downstream" are defined according to the flow direction of the sample gas. Specifically, refer to Figure 3 or Figure 4 The arrows indicate the direction. "Inside" and "outside" refer to the outlines of the corresponding components. Terms such as "first" and "second" used in this disclosure are intended to distinguish one element from another and do not imply order or importance. In addition, when the following description refers to the drawings, the same reference numerals in different drawings represent the same or similar elements.

[0020] Reference Figure 1-Figure 3The present disclosure provides a sampling system that can be used to sample gas at multiple sampling points in a powder making system. The sampling system can include multiple sampling probes 1, multiple probe solenoid valves 21, a detection unit 3, and a backflush unit 4. Multiple sampling probes 1 can be set in a one-to-one correspondence at multiple sampling points, and multiple sampling points can be set at different locations in the powder making system, allowing multiple sampling probes 1 to sample at different locations in the powder making system, facilitating a comprehensive understanding of the system's sample gas characteristics. Multiple probe solenoid valves 21 can be set in a one-to-one correspondence with multiple sampling probes 1 to adjust the sampling parameters of the sampling probes 1 to preset parameters. The multiple probe solenoid valves 21 can adjust the sampling parameters of multiple sampling probes 1 to be the same, thereby improving data reliability and consistency. The detection unit 3 can be used to detect the sampling parameters of the sampling probes 1, which can be the sampling gas flow rate, to achieve real-time monitoring of the sample gas parameters, promptly detect abnormal conditions in the system, and ensure the stability and safety of the production process. The detection unit 3 can also control the opening and closing of the probe solenoid valves 21 to determine the operating status of the sampling probes 1. The back-flushing part 4 is connected to the detection part 3 and is configured to, after the probe solenoid valve 21 performs the opening and closing actions, when the sampling parameter difference of the sampling probe 1 corresponding to the probe solenoid valve 21 is lower than the preset difference, perform a purge operation on the sampling probe 1 to ensure the cleanliness and accuracy of the sampling probe 1. By connecting with the detection part 3, real-time monitoring and automatic purge can be achieved, which effectively shortens the sampling cycle, ensures that the system can obtain accurate fluid samples at different time points, and improves the timeliness of the data.

[0021] Through the above technical solution, the detection unit 3 monitors the abnormalities of the sampling parameters in real time, and repeatedly controls the probe solenoid valve 21 to perform opening and closing actions to detect abnormalities in the sampling probe 1 and determine the blocked sampling probe 1, and controls the back-blowing unit 4 to blow the blocked sampling probe 1, thereby clearing and cleaning the sampling probe 1, thereby achieving comprehensive sampling of the powder making system and improving the accuracy of sampling.

[0022] Reference Figure 1 The sampling system may further include a plurality of sampling tubes 61 for connecting the plurality of sampling probes 1 to the detection portion 3, and a plurality of probe solenoid valves 21 are installed one-to-one on the plurality of sampling tubes 61, wherein the plurality of sampling tubes 61 have the same length. Such a design can ensure that the samples at each sampling point have similar flow conditions, effectively avoiding the pressure loss caused by the difference in pipe length, thereby improving the consistency and comparability of the samples and ensuring the accuracy and reliability of the sampling data.

[0023] Reference Figure 1 、 Figure 2 as well as Figure 4The detection unit 3 may include a controller 33, and a flow stabilizer 31 and a parameter sensor 32 connected in sequence downstream of the sampling tube 61. Among them, the flow stabilizer 31 can be used to keep the sample gas continuous and stable, the parameter sensor 32 can be used to detect the sample gas flow rate, and the controller 33 can be used to receive the flow signal of the parameter sensor 32, and adjust the opening of the probe solenoid valve 21 and the purge time of the backflush unit 4 according to the flow signal. In the embodiment provided by the present disclosure, the parameter sensor 32 may include a mass flow sensor 321 and a pressure sensor 322. When the mass flow sensor 321 and the pressure sensor 322 display that the sample gas flow rate and pressure are high or low, the controller 33 will give corresponding instructions to the probe solenoid valve 21 arranged upstream of the mass flow sensor 321, and adjust the opening and closing of the probe solenoid valve 21 within a certain range, opening it smaller when the sample gas flow rate is high and opening it larger when the sample gas flow rate is low. When the probe solenoid valve 21 is adjusted to indicate that the probe is clogged and that probe cleaning and backflushing are required, the controller 33 sends a signal to the backflushing unit 4, which then performs a backflushing operation on the sampling probe 1. The backflushing time and frequency are calculated and executed by the controller 33. In the embodiment provided herein, the controller 33 may include a PLC remote control system to control the backflushing unit 4 to purge and clean the clogged sampling probe 1.

[0024] Further, refer to Figure 1 and Figure 4The sampling system can also include an exhaust pipe 62. The exhaust gas inlet of the exhaust pipe 62 can be connected between the flow stabilizer 31 and the parameter sensor 32, and the exhaust gas outlet of the exhaust pipe 62 can be connected to the exhaust gas collection part. The outlet of the flow stabilizer 31 is connected to the sampling pipe 61 and the exhaust pipe 62 through the three-way valve 22. The probe solenoid valve 21 is connected to the sampling pipe 61. The exhaust pipe 62 can be provided with an exhaust electric regulating valve; the outlet of the probe solenoid valve 21 can be connected to the mass flow sensor 321 and then connected to the pressure sensor 322, and then enter the controller 33 to monitor and control the sample gas flow, and then enter the filter component 7 mentioned below; because the pressure and flow rate of the sample gas have a great influence on the stability and measurement accuracy of the sensors of the back-end analysis system, the sample gas needs to maintain a stable pressure and flow rate. The flow and pressure of the sample gas can be adjusted by the opening and closing amount of the probe solenoid valve 21 and the exhaust gas throttle valve 63. When the mass flow sensor 321 and the pressure sensor 322 indicate high or low sample gas flow and pressure, the controller 33 sends corresponding instructions to the probe solenoid valve 21 and the exhaust gas throttle valve 63, regulating the flow within a certain range by controlling the opening and closing of the probe solenoid valve 21, opening it narrowly when the sample gas flow is high and widening it when the sample gas flow is low. If adjusting the probe solenoid valve 21 has no significant effect when the sample gas flow is low, the exhaust gas throttle valve 63 needs to be adjusted. By gradually closing the exhaust gas throttle valve 63, the appropriate sample gas flow and pressure can be achieved. If adjusting both the probe solenoid valve 21 and the exhaust gas throttle valve 63 has no effect, indicating that the probe is clogged, a probe purge and backflush operation is required. The controller 33 sends a signal to the backflush unit 4, which performs a purge and backflush operation on the sampling probe 1. The backflush time and frequency are calculated and executed by the controller 33. These controls and operations are completely automated by the embedded software within the controller 33, eliminating the need for human intervention and improving sampling accuracy and cancellation efficiency.

[0025] Reference Figure 1-Figure 3 The sampling system also includes a filter assembly 7, which may include a filter tube 71 connected downstream of the detection unit 3, and a steam-water separator body 72, a dehydration filter 73, and a condenser 74 that are sequentially connected to the filter tube 71. The steam-water separator body 72 can be used to perform a first dehydration filtration on the sample gas. The dehydration filter 73 can include a fine filter 731 and a precision filter 732. The air outlet of the steam-water separator body 72 can be connected to the fine filter 731, which can be used for a second dust filtration. The outlet of the fine filter 731 can be connected to the inlet of the precision filter 732, which can be used for a third dust filtration. The outlet of the precision filter 732 can be connected to the air inlet of the condenser 74 to perform a second dehydration filtration on the sample gas. By performing multiple dehydration filtrations on the sample gas, the moisture content in the gas can be significantly reduced, preventing moisture from corroding and damaging downstream equipment. While protecting the normal operation of the equipment, it can also reduce potential safety hazards and ensure the safety of the operating environment.

[0026] Reference Figure 1 and Figure 3 The sampling system may further include a drainage component 8 for receiving wastewater from the filter component 7. The drainage component 8 may include a wastewater collector 81, a first drain pipe 82, and a second drain pipe 83. The first drain pipe 82 may be connected between the wastewater collector 81 and the steam-water separator body 72, and the second drain pipe 83 may be connected between the dewatering filter 73 and the wastewater collector 81. The first drain pipe 82 is used to discharge the water filtered out of the steam-water separator body 72 into the wastewater collector 81 for unified collection and treatment of the wastewater. The second drain pipe 83 is used to discharge the water filtered out of the steam-water separator body 72 into the wastewater collector 81 for unified collection and treatment of the wastewater. In the present disclosure, a peristaltic pump 84 may be provided on each of the first drain pipe 82 and the second drain pipe 83. The peristaltic pump 84 does not generate bubbles during the process of conveying wastewater, thereby ensuring the wastewater conveying effect and providing power for the wastewater conveying.

[0027] Reference Figure 1 The sampling system may further include an analysis cabinet 5 connected downstream of the filter assembly 7. The analysis cabinet 5 may be used to analyze the sample gas after dust removal and water removal. This can not only promptly detect failures or performance degradation of the filter assembly 7, facilitate maintenance and adjustment, and avoid potential production problems, but also monitor the composition of the filtered sample gas to avoid direct discharge of harmful substances or pollutants, thereby ensuring operational safety and environmental protection.

[0028] Reference Figure 1 The pulverizing system of the present disclosure may include a coal mill separator 101 and a plurality of air-powder ducts 102. After the coal mill pulverizes, the pulverized coal is separated into coarse and fine powders through the coal mill separator 101. The pulverized coal that meets the combustion requirements enters the burner 104 through the air-powder duct 102 and then enters the furnace for combustion and power generation. The sampling points may include a plurality of first sampling points and a plurality of second sampling points. The first sampling points may be evenly distributed at intervals on the peripheral wall of the coal mill separator 101, and the plurality of second sampling points may be respectively arranged on the plurality of air-powder ducts 102 in a one-to-one correspondence. Accordingly, the sampling probe 1 may include a first sampling probe 11 corresponding to the first sampling point and a second sampling probe 12 corresponding to the second sampling point. By sampling at different positions of the coal mill separator 101 and different air-powder ducts 102, more comprehensive and accurate gas characteristic data may be obtained, thereby improving the accuracy and reliability of the sampling measurement.

[0029] Reference Figure 1 and Figure 2, the sampling points provided by the present invention can be provided with sampling holes 103, that is, the first sampling point corresponding to the coal mill body separator 101 and the second sampling point corresponding to the multiple air-powder pipes 102 can be provided with sampling holes 103 respectively, the opening of the sampling hole 103 can protrude outward from the installation surface, and the sampling probe 1 can be inserted into the opening, so that the sampling probe 1 can be prevented from penetrating into the interior of the installation surface, that is, the interior of the air-powder pipe 102, thereby effectively preventing the risk of the sampling probe 1 being damaged by air and powder, ensuring the safety of the working environment of the sampling probe 1, and providing reliable protection for the sustainable sampling work. The following is an example of the sampling hole 103 set on the air-powder pipe 102 for detailed description. Figure 2 As shown, a flange 105 can be provided at the sampling point. The flange 105 can be welded and fixed to the wall of the air-powder duct 102. The flange 105 can have a large diameter section and a small diameter section. The small diameter section is partially inserted into the wall of the air-powder duct 102 to form an opening. To prevent the air and powder in the air-powder duct 102 from eroding and wearing the flange 105, the flange 105 is flush with the inner wall of the air-powder duct 102 and does not extend into the interior of the air-powder duct 102. The sampling probe 1 has an end face that can be fitted with the flange 105 and a sampling portion that is partially inserted into the opening. The end face of the sampling probe 1 can be connected to the flange 105 by bolts 106. The bolts 106 pass through the flange 105 and are inserted into the end face of the opening to achieve a detachable connection between the two. In the present disclosure, multiple bolts 106 can be arranged circumferentially along the end face of the sampling probe 1 to improve the connection strength between the two. The flange 105 can be mounted with a sampling tube inspection valve 611 and a backflush pipe 42. The backflush pipe 42 can be used to supply backflush gas, and a backflush inspection valve 41 can be provided on the backflush pipe 42. The flange 105 effectively connects the sampling tube inspection valve 611 and the backflush inspection valve 41 to the sampling probe 1, allowing for routine tightness inspection and maintenance of the backflush pipe 42 and the sampling tube 61 without shutting down the machine, as well as repairs in the event of leakage or damage. A pulverized coal filter 13 can be installed on the portion of the sampling probe 1 that extends into the opening to prevent clogging of the sampling probe 1. In the embodiments provided herein, the sampling probe 1 can be divided into three sizes: long, short, and medium, depending on the different air-powder ducts 102 and different pulverizer body separators 101. To protect the pulverized coal filter 13 and extend its service life, a pulverized coal filter protective component 14 can be provided on the pulverized coal filter 13. This pulverized coal filter protective component 14 can vary depending on the size of the pulverized coal filter 13. Such a design avoids the use of electrical components and greatly eliminates the explosion-proof problem of the sampling probe 1 in the powder making system.

[0030] According to a second aspect of the present disclosure, a sampling method is provided. The sampling method uses the sampling system provided by the present disclosure to sample a powder making system. The method includes: step S1, where a detection unit 3 detects the sampling gas flow rate at a sampling probe 1; step S2, where, when the sampling gas is abnormal, for example, below a preset gas flow rate, the probe solenoid valve 21 is controlled to open and close; step S3, where the detection unit 3 automatically determines a clogged sampling probe 1 through calculation; and step S4, where the detection unit 3 controls the backflush unit 4 to backflush the clogged sampling probe 1. All the beneficial effects of the sampling system are not further elaborated herein.

[0031] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0032] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0033] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A sampling system for sampling gas at multiple sampling points in a pulverizing system, characterized in that: The sampling system comprises: A plurality of sampling probes are arranged at the plurality of sampling points in a one-to-one correspondence; A plurality of probe solenoid valves are provided corresponding to the plurality of sampling probes one by one, and are used to adjust the sampling parameters of the sampling probes to preset parameters; A detection unit, used to detect the sampling parameters of the sampling probe and control the opening and closing of the probe solenoid valve; The back-flushing part is connected to the detection part and is configured to perform a purge operation on the sampling probe after the probe solenoid valve performs an opening and closing action and when the sampling parameter difference of the sampling probe corresponding to the probe solenoid valve is lower than a preset difference.

2. The sampling system according to claim 1, characterized in that It also includes a plurality of sampling tubes for connecting the plurality of sampling probes to the detection part respectively, and the plurality of probe solenoid valves are installed on the plurality of sampling tubes in a one-to-one correspondence, wherein the plurality of sampling tubes have the same length.

3. The sampling system according to claim 2, characterized in that The detection unit includes a controller, and a flow stabilizer and a parameter sensor connected in sequence downstream of the sampling tube, wherein the parameter sensor is used to detect the flow rate of the sampling gas, and the controller is used to receive the flow signal of the parameter sensor and adjust the opening of the probe solenoid valve and the purge time of the back-blowing unit according to the flow signal.

4. The sampling system according to claim 3, characterized in that It also includes an exhaust pipe, an exhaust gas inlet of the exhaust gas pipe is connected between the flow stabilizer and the parameter sensor, and an exhaust gas outlet of the exhaust gas pipe is connected to the exhaust gas collecting part.

5. The sampling system according to claim 3, characterized in that The sampling system further comprises a filter assembly, which comprises a filter tube connected to the downstream of the detection part, and a steam-water separator body, a water removal filter and a condenser which are sequentially connected to and arranged on the filter tube.

6. The sampling system according to claim 5, characterized in that The sampling system also includes a drainage component for receiving wastewater from the filter component, the drainage component including a wastewater collector, a first drainage pipe connected between the wastewater collector and the steam-water separator body, and a second drainage pipe connected between the water removal filter and the wastewater collector.

7. The sampling system according to claim 5, characterized in that The sampling system further comprises an analysis cabinet connected downstream of the filter assembly, and the analysis cabinet is used to analyze the sample gas after dust removal, water removal and filtration.

8. The sampling system according to any one of claims 1 to 7, characterized in that: The pulverizing system includes a coal mill separator and multiple air-powder ducts. The sampling points include first sampling points evenly distributed on the peripheral wall of the coal mill separator and second sampling points respectively arranged on the multiple air-powder ducts.

9. The sampling system according to claim 8, characterized in that A sampling hole is provided at the sampling point, the opening of the sampling hole protrudes outward from the mounting surface, and the sampling probe is inserted into the opening.

10. A sampling method, characterized in that: The milling system is sampled using the sampling system according to any one of claims 1 to 9.

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