Coal pulverizing system safety monitoring and boiler combustion optimizing system and method

Abstract

The invention relates to a coal pulverizing system safety monitoring and boiler combustion optimizing system and method, and the system comprises a coal pulverizing system which comprises a plurality of coal mill bodies and primary air powder pipes connected with the coal mill bodies; the plurality of sampling probes are respectively arranged on the coal mill body and / or the primary air powder pipes corresponding to the coal mill body; each CO monitoring device comprises a main cabinet, a gas sensor, a filtering module and a signal converter; the filtering module is used for receiving sampling gas of the sampling probe, the gas sensor is used for detecting the CO concentration filtered by the filtering module, and the signal converter is electrically connected with the gas sensor; the DCS control host is connected with the signal converter; the execution device comprises an alarm and a temperature adjusting module, and the alarm is used for triggering an alarm signal according to the CO concentration threshold value; the temperature adjusting module is used for adjusting the temperature of the outlet of the coal mill according to the CO concentration threshold value. The system can reduce the exhaust gas temperature of the boiler and reduce the carbon content of fly ash, so that the boiler efficiency is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of coal mill equipment, and in particular to a pulverizing system safety monitoring and boiler combustion optimization system and method. Background Art

[0002] At present, the pulverizing systems of the main thermal power plants with a capacity of more than 300MW currently in operation in my country mostly use double-inlet and double-outlet steel ball mills or medium-speed coal mills. These two types of coal mills mainly grind bituminous coal and lignite series. Both have an internal positive pressure of about 5-8KPa, and the coal powder fineness R90 is in the range of 15-30%, which can meet the requirements of fineness and uniformity of boiler power coal.

[0003] The pulverizer outlet temperature is generally controlled within the range of 60-85°C, depending on the volatile matter content of the bituminous coal and the type of pulverizer and pulverizing system, as calculated according to the "DLT5145-2012 Specification for Design and Calculation of Pulverizing Systems for Thermal Power Plants." A survey of 150 operating coal-fired boilers in China revealed that approximately 42% of these boilers have experienced spontaneous combustion or internal explosion. To ensure the safety of their pulverizing systems, many power plants minimize the primary air temperature at the pulverizer outlet, resulting in higher exhaust temperatures and lower boiler efficiency.

[0004] At present, most coal mill protection systems use temperature monitoring systems, that is, they use thermocouples to measure temperature. However, this monitoring system has a weak theoretical basis and requires many measuring points, making it difficult to cover the pre-monitoring area of ​​the entire pulverizing system. In addition, its reliability is poor, and the monitoring results are seriously delayed, which cannot meet the function of safety accident warning.

[0005] Therefore, the pulverizer outlet temperature must be strictly controlled, which seriously restricts the improvement of boiler efficiency. Therefore, in view of the current problems of the pulverizing system such as the lack of safety monitoring measures and low pulverizer outlet temperature, providing a pulverizing system safety online monitoring and boiler combustion optimization system is a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the Invention

[0006] The purpose of the present disclosure is to provide a pulverizing system safety monitoring and boiler combustion optimization system and method to solve the technical problems existing in the related art.

[0007] To achieve the above objectives, the present disclosure provides a pulverizing system safety monitoring and boiler combustion optimization system, comprising: The pulverizing system includes multiple coal mill bodies and primary air pulverizing pipes connected thereto; A plurality of sampling probes are respectively arranged on the coal mill body and / or the corresponding primary air powder pipe; Multiple CO monitoring devices, including a main cabinet, a gas sensor, a filter module and a signal converter; the gas sensor, the filter module and the signal converter are all arranged in the main cabinet; The filtering module is used to receive the sampled gas from the sampling probe, the gas sensor is used to detect the CO concentration after filtering by the filtering module, and the signal converter is electrically connected to the gas sensor and is used to convert the CO concentration into an electrical signal; A DCS control host connected to the signal converter to receive and display CO concentration data; The execution device includes an alarm and a temperature adjustment module. The alarm is used to trigger an alarm signal according to the CO concentration threshold; the temperature adjustment module is used to adjust the temperature of the coal mill outlet according to the CO concentration threshold.

[0008] Optionally, each coal mill body is provided with two sampling probes, and the two sampling probes are arranged on two opposite sides of the separator of the coal mill body.

[0009] Optionally, the CO monitoring devices are provided in three pieces, namely a first monitoring device, a second monitoring device and a third monitoring device; There are six coal mill bodies, and the primary air powder pipe corresponding to each of the five coal mill bodies is provided with a sampling probe in the first area, the second area, the third area and the fourth area respectively; wherein the first monitoring device is in communication with the twelve sampling probes of the six coal mill bodies; The second monitoring device is connected to the five sampling probes of the five primary air powder tubes under the first area and to the five sampling probes of the five primary air powder tubes under the second area; The third monitoring device is connected to the five sampling probes of the five primary air powder tubes under the third area and to the five sampling probes of the five primary air powder tubes under the fourth area.

[0010] Optionally, the system further includes a burner, which includes a burner body and a burner elbow, and the outlet of the primary air powder tube is connected to the burner elbow; wherein the distance between the sampling probe corresponding to the primary air powder tube and the burner elbow is between 500 mm and 700 mm.

[0011] The present disclosure further provides a method for safety monitoring of a pulverizing system and optimizing boiler combustion, the method comprising: Step S1: Collecting CO concentration data in real time through sampling probes distributed on the coal mill body and the primary air powder pipe, and transmitting the data to the DCS control host; Step S2: Calculate the average CO concentration under normal operation and adjust it upward to generate an alarm threshold; Step S3: When the current CO concentration is less than or equal to the alarm threshold, it is determined to be safe and the temperature adjustment module performs a temperature increase operation; when the current CO concentration is greater than the alarm threshold, the alarm is triggered; Step S4: In a safe state, the temperature regulating module is used to adjust the ratio of cold and hot primary air to increase the outlet temperature of the coal mill body, and the CO concentration change trend is recorded every 1°C increase in temperature; Step S5: If the CO concentration exceeds the alarm threshold during the heating process, stop heating and return to the initial temperature; or, if the CO concentration exceeds the alarm threshold during the heating process, continue ventilation and purge or stop grinding for inspection until the CO concentration is ≤ the alarm threshold and lasts for at least 1 hour.

[0012] Optionally, calculating the average CO concentration under normal operation and adjusting it upward to generate an alarm threshold includes: Collect at least 7 days of normal unit operation data and calculate the daily average CO concentration; The daily average value is adjusted upward by 50 ppm as the alarm threshold; When the current CO concentration exceeds the alarm threshold and lasts for ≥10 minutes, an alarm is triggered.

[0013] Optionally, the method further comprises step S6: According to the stability of CO concentration after temperature increase, the reduction value of boiler exhaust gas temperature ΔT and coal consumption reduction value ΔQ are calculated. The formula is: ΔT = 3.6×(ΔT_initial / 10)°C, ΔQ = 0.8×(ΔT_initial / 10)g / Kwh, where ΔT_initial is the initial temperature rise.

[0014] Optionally, the continuous ventilation and purge or grinding stop inspection includes: Start the standby fan to force ventilation on the primary air-powder pipe and purge the inside of the coal mill body with inert gas; alternatively, manually clean the accumulated powder and check the sealing after stopping the mill.

[0015] Optionally, the temperature regulating controller controls the outlet temperature by adjusting the ratio of the opening of the cold and hot primary air doors of the coal mill, with a heating rate of 1°C / minute and a maximum temperature rise not exceeding 20°C from the initial temperature.

[0016] Optionally, the gas sensor is an electrochemical CO sensor with a measuring range of 0-500 ppm, an accuracy of ±5 ppm, and a response time of ≤30 seconds.

[0017] In this technical solution, by installing a sampling probe in the pulverizing system and combining it with the real-time detection function of the CO monitoring device, dynamic, real-time monitoring of the CO concentration within the pulverizing system can be achieved. This ensures that the CO concentration data truly reflects the operating status of the coal mill and the air-powder duct, reducing monitoring errors caused by localized dust accumulation or leakage.

[0018] Secondly, when CO concentration exceeds the threshold, the alarm triggers an audible and visual alarm, alerting operators to investigate potential hazards. This design, through dynamic threshold adaptation, avoids false or missed alarms caused by variations in coal type and load, as with traditional fixed thresholds, thereby improving system safety. When CO concentration falls below the alarm threshold, the temperature control module adjusts the ratio of the cold and hot primary air openings in the pulverizer to control the pulverizer outlet temperature. This lowers the boiler exhaust temperature and reduces the carbon content in the fly ash, thereby improving boiler efficiency.

[0019] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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 It is a schematic structural diagram of a pulverizing system safety monitoring and boiler combustion optimization system according to an embodiment of the present invention.

[0021] Figure 2 It is a structural diagram of a pulverizing system safety monitoring and boiler combustion optimization system according to an embodiment of the present invention.

[0022] Figure 3 It is a structural schematic diagram of a pulverizing system of a pulverizing system safety monitoring and boiler combustion optimization system according to an embodiment of the present invention.

[0023] Figure 4 It is a partial structural diagram of a pulverizing system safety monitoring and boiler combustion optimization system according to an embodiment of the present invention.

[0024] Description of Reference Numerals 100, pulverizing system; 110, coal mill body; 1101, separator; 120, primary air pulverizing pipe; 200, sampling probe; 300, CO monitoring device; 310, main cabinet; 320, gas sensor; 330, filter module; 340, signal converter; 3001, first monitoring device; 3002, second monitoring device; 3003, third monitoring device; 400, DCS control host; 600, execution device; 610, alarm; 620, temperature adjustment module; 700, burner; 710, burner body; 720, burner elbow; DETAILED DESCRIPTION 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.

[0025] Reference Figures 1 to 4 As shown, the present disclosure provides a pulverizing system safety monitoring and boiler combustion optimization system, which includes: The pulverizing system 100 includes a plurality of coal mill bodies 110 and primary air pulverizing pipes 120 connected thereto.

[0026] A plurality of sampling probes 200 are respectively disposed on the coal mill body 110 and / or the corresponding primary air powder pipe 120 .

[0027] The plurality of CO monitoring devices 300 include a main cabinet 310 , a gas sensor 320 , a filter module 330 , and a signal converter 340 . The gas sensor 320 , the filter module 330 , and the signal converter 340 are all disposed in the main cabinet 310 .

[0028] The filter module 330 is used to receive the sampled gas from the sampling probe 200 . The gas sensor 320 is used to detect the CO concentration after filtering by the filter module 330 . The signal converter 340 is electrically connected to the gas sensor 320 and is used to convert the CO concentration into an electrical signal.

[0029] The DCS control host 400 is connected to the signal converter 340 to receive and display the CO concentration data.

[0030] The execution device 600 includes an alarm 610 and a temperature adjustment module 620. The alarm 610 is used to trigger an alarm signal according to the CO concentration threshold; the temperature adjustment module 620 is used to adjust the temperature of the coal mill outlet according to the CO concentration threshold.

[0031] In the above technical solution, sampling probes 200 are installed at key locations within the pulverizing system 100 (such as the air-powder pipe section at the outlet of the coal mill 110 and the branch line of the primary air-powder pipe 120). Combined with the real-time detection capabilities of the CO monitoring device 300, dynamic, real-time monitoring of the CO concentration within the pulverizing system 100 is achieved. For example, the layout design of the sampling probes 200 avoids the single monitoring point or blind spot issues of traditional monitoring, ensuring that CO concentration data truly reflects the operating status of the coal mill 110 and the air-powder pipe 120, reducing monitoring errors caused by localized dust accumulation or leakage.

[0032] Secondly, when the CO concentration exceeds the threshold, alarm 610 triggers an audible and visual alarm, alerting operators to investigate potential hazards (such as dust accumulation within the pulverizer or leaks in the air-powder pipe). This design, through dynamic threshold adaptation, avoids false or missed alarms caused by variations in coal type and load using traditional fixed thresholds, thereby improving system safety. When the CO concentration falls below the alarm threshold, the temperature control module 620 adjusts the ratio of the cold and hot primary air openings in the pulverizer to increase the pulverizer outlet temperature. This lowers the boiler exhaust temperature and reduces the carbon content in the fly ash, thereby improving boiler efficiency.

[0033] In one embodiment, reference Figure 3 As shown, each coal mill body 110 is provided with two sampling probes 200 , and the two sampling probes 200 are provided on two opposite sides of the separator 1101 of the coal mill body 110 .

[0034] In this embodiment, two sampling probes 200 are symmetrically arranged on either side of the separator 1101, covering the CO concentration distribution in different areas within the pulverizer body 110. Because the separator 1101 is the core component for separating pulverized coal from the airflow, airflow velocity and pulverized coal concentration may vary on either side. Symmetrical sampling provides a more comprehensive picture of the spatial uniformity of CO concentration within the pulverizer body 110, avoiding monitoring deviations caused by localized airflow disturbances or pulverized coal accumulation associated with single-point sampling and improving data representativeness.

[0035] In another embodiment, referring to Figure 2 As shown, three CO monitoring devices 300 are provided, namely a first monitoring device 3001, a second monitoring device 3002 and a third monitoring device 3003; There are six coal mill bodies 110, and each of the five coal mill bodies 110 corresponding to the primary air powder pipe 120 is equipped with a sampling probe 200 in the first, second, third, and fourth zones, respectively. A first monitoring device 3001 is connected to the twelve sampling probes 200 of the six coal mill bodies 110; a second monitoring device 3002 is connected to the five sampling probes 200 of the five primary air powder pipes 120 in the first zone and the five sampling probes 200 of the five primary air powder pipes 120 in the second zone; and a third monitoring device 3003 is connected to the five sampling probes 200 of the five primary air powder pipes 120 in the third zone and the five sampling probes 200 of the five primary air powder pipes 120 in the fourth zone.

[0036] In this implementation, multiple sampling probes 200 are distributed across three monitoring devices, preventing single-point failures from causing system-wide failure. For example, if the second monitoring device 3002 fails, the third monitoring device 3003 can still monitor the sampling probes 200 in the third and fourth zones, ensuring safety in certain areas. If the CO concentration in a particular zone (such as the first zone) is abnormal, data from the five probes in the second monitoring device 3002 can be directly correlated to quickly identify the faulty air-powder pipe or coal mill, reducing troubleshooting time.

[0037] Optionally, refer to Figure 4 As shown, the above system also includes a burner 700, which includes a burner body 710 and a burner elbow 720. The outlet of the primary air powder tube 120 is connected to the burner elbow 720; wherein, the distance between the sampling probe 200 corresponding to the primary air powder tube 120 and the burner elbow 720 is between 500 mm and 700 mm.

[0038] In this embodiment, the sampling probe 200 is positioned within 500-700 mm of the burner elbow 720, allowing direct monitoring of the CO concentration in the air-powder mixture before it enters the combustion zone. This position avoids local concentration deviations caused by high-speed airflow disturbances within the burner elbow while also capturing the combustion state of the pulverized coal at the burner inlet in real time. For example, when the pulverized coal experiences localized oxygen deficiency due to an imbalance in the air-powder ratio, the CO concentration rapidly increases. The probe 200 immediately feeds this data back to the DCS control host 400, triggering the temperature control module 620 to adjust the ratio of hot and cold air, optimizing combustion conditions and reducing losses from incomplete combustion.

[0039] The present disclosure also provides a method for safety monitoring of a pulverizing system and optimizing boiler combustion, the method comprising: Step S1: The sampling probes 200 distributed on the coal mill body 110 and the primary air powder pipe 120 collect CO concentration data in real time and transmit the data to the DCS control host 400; Step S2: Calculate the average CO concentration under normal operation and adjust it upward to generate an alarm threshold; Step S3: When the current CO concentration is less than or equal to the alarm threshold, it is determined to be safe and the temperature adjustment module 620 performs a temperature increase operation; when the current CO concentration is greater than the alarm threshold, the alarm 610 is triggered; Step S4: In a safe state, the temperature regulating module 620 is used to adjust the ratio of cold and hot primary air to increase the outlet temperature of the coal mill body 110, and the CO concentration change trend is recorded every 1°C increase in temperature; Step S5: If the CO concentration exceeds the alarm threshold during the heating process, stop heating and return to the initial temperature; or, if the CO concentration exceeds the alarm threshold during the heating process, continue ventilation and purge or stop grinding for inspection until the CO concentration is ≤ the alarm threshold and lasts for at least 1 hour.

[0040] In the above technical solution, dynamic threshold setting and a graded response mechanism, combined with data-driven combustion optimization and automated closed-loop control, achieve a synergistic improvement in pulverizing system safety and boiler combustion efficiency. The DCS control host 400 monitors the CO concentration of the pulverizer body 110 and the primary air-powder pipe 120 in real time, reducing the risk of false alarms. When the CO concentration is ≤ the alarm threshold, the temperature control module 620 automatically adjusts the ratio of hot and cold primary air, gradually increasing the pulverizer outlet temperature and optimizing the air-powder ratio through a closed-loop data feedback loop. If the CO concentration exceeds the standard during the heating process, the system immediately stops heating and returns the temperature, or triggers graded measures such as ventilation and purge, mill shutdown, and inspection, until the CO concentration is ≤ the threshold and remains stable for one hour, avoiding system-wide shutdown.

[0041] Optionally, calculating the average CO concentration under normal operation and adjusting it upward to generate an alarm threshold includes: collecting at least 7 days of normal operation data of the unit, calculating a daily average CO concentration; adjusting the daily average by 50 ppm as the alarm threshold; and triggering an early warning when the current CO concentration exceeds the alarm threshold and lasts for ≥10 minutes.

[0042] In this implementation, the system calculates the daily average CO concentration by collecting at least seven days of normal operating data, and introduces a 50 ppm dynamic offset to generate an alarm threshold (e.g., daily average + 50 ppm), effectively adapting to differences in operating conditions such as changes in coal type and load fluctuations.

[0043] When CO concentration exceeds a threshold and persists for 10 minutes or longer, an alarm is triggered. This design, through dual time-concentration constraints, avoids false alarms caused by transient fluctuations (such as instantaneous damper disturbances) while promptly capturing real safety hazards (such as the slow rise in CO concentration during the initial stages of spontaneous combustion of accumulated dust). For example, if a sudden change in coal quality causes an increase in CO production, the dynamic threshold automatically matches the current operating conditions, preventing frequent false alarms from the fixed threshold. The 10-minute trigger rule eliminates transient anomalies and activates the alarm only when a real risk (such as an air-powder pipe leak) occurs. This solution, combined with the hierarchical response logic of the temperature control module 620 (temperature rise back or ventilation purge), achieves a closed-loop collaboration between safety warnings and combustion optimization, ultimately reducing the risk of equipment shutdown and improving boiler operational stability.

[0044] In another embodiment, the above method further includes step S6: According to the stability of CO concentration after temperature increase, the reduction value of boiler exhaust gas temperature ΔT and coal consumption reduction value ΔQ are calculated. The formula is: ΔT = 3.6×(ΔT_initial / 10)°C, ΔQ = 0.8×(ΔT_initial / 10)g / Kwh, where ΔT_initial is the initial temperature rise.

[0045] This implementation directly links combustion optimization with energy efficiency improvements, achieving a dual breakthrough in safety control and economic optimization. In step S6, based on the stability of CO concentration after temperature increase (i.e., no excessive fluctuations), the system establishes a quantitative relationship between the increase in mill outlet temperature (ΔT_initial), the decrease in boiler exhaust temperature (ΔT), and the reduction in coal consumption (ΔQ) using the formulas ΔT = 3.6×(ΔT_initial / 10)°C and ΔQ = 0.8×(ΔT_initial / 10)g / KWh (ΔT_initial represents the initial temperature rise). For example, if the initial temperature rise is 10°C (ΔT_initial = 10°C), the exhaust temperature decreases by 3.6°C, resulting in a 0.8g / KWh reduction in coal consumption. If the temperature rise increases to 20°C, the exhaust temperature decrease increases to 7.2°C, resulting in a 1.6g / KWh reduction in coal consumption. This design quantifies energy efficiency improvements through a mathematical model, allowing operators to directly predict energy savings based on temperature rise targets.

[0046] Optionally, the above-mentioned continuous ventilation and purging or shutdown inspection includes: starting the standby fan to force ventilation of the primary air and powder pipe 120 and purging the interior of the coal mill body 110 with inert gas; or manually cleaning the accumulated powder and checking the sealing after stopping the mill.

[0047] In this embodiment, when CO concentration exceeds the specified limit, the system activates a backup fan for forced ventilation or inert gas purge (such as nitrogen injection). This rapidly dilutes the CO concentration within the pulverizer body 110 and the primary air-powder pipe 120 (for example, forced ventilation can reduce the CO concentration to below the safety threshold within 5 minutes). This also suppresses oxidation reactions in the pulverized coal-rich area, preventing the risk of spontaneous combustion or explosion. If the CO concentration still exceeds the specified limit after ventilation, a mill shutdown inspection and manual cleaning process are triggered. This process removes accumulated pulverized coal (such as deposits caused by agglomeration or seal failure) and repairs sealing defects (such as flange air leakage), eliminating the hidden danger at its source. This design combines dynamic response with physical isolation, avoiding production losses caused by traditional full system shutdowns (for example, shutting down only the faulty pulverizer rather than the entire production line). Furthermore, inert gas purges reduce oxygen concentration (theoretically, the lower explosion limit can be increased by over 20%), significantly improving the system's intrinsic safety rating. Furthermore, manual cleaning and seal inspections simultaneously optimize pulverizer operating parameters (for example, reducing fluctuations in the air-powder ratio), indirectly improving combustion efficiency.

[0048] Optionally, the temperature regulating controller 620 controls the outlet temperature by adjusting the ratio of the opening of the cold and hot primary air doors of the coal mill, with a heating rate of 1°C / minute and a maximum temperature rise not exceeding 20°C from the initial temperature.

[0049] In this embodiment, a heating rate of 1°C / minute avoids thermal stress concentration in the pulverizer body 110 and the primary air-powder pipe 120 caused by sudden temperature changes, reduces the risk of metal fatigue and seal aging, extends the life of the equipment, and optimizes the uniformity of air-powder mixing through precise matching of hot and cold air, thereby improving the ignition stability and burnout rate of coal powder.

[0050] Optionally, the gas sensor 320 is an electrochemical CO sensor with a measurement range of 0-500 ppm, an accuracy of ±5 ppm, and a response time of ≤30 seconds.

[0051] In this embodiment, the gas sensor 320 can accurately warn of abnormal CO concentrations, preventing explosions or spontaneous combustion accidents. It supports millisecond-level data feedback, achieving a closed-loop combustion optimization. It covers the monitoring needs of the pulverizing system throughout its entire lifecycle. Its long-life design reduces replacement frequency and minimizes downtime losses. However, this disclosure does not limit the specific type of gas sensor 320.

[0052] 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.

[0053] 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.

[0054] 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 pulverizing system safety monitoring and boiler combustion optimization system, characterized in that: include: The pulverizing system includes multiple coal mill bodies and primary air pulverizing pipes connected thereto; A plurality of sampling probes are respectively arranged on the coal mill body and / or the corresponding primary air powder pipe; Multiple CO monitoring devices, including a main cabinet, a gas sensor, a filter module and a signal converter; the gas sensor, the filter module and the signal converter are all arranged in the main cabinet; The filtering module is used to receive the sampled gas from the sampling probe, the gas sensor is used to detect the CO concentration after filtering by the filtering module, and the signal converter is electrically connected to the gas sensor and is used to convert the CO concentration into an electrical signal; A DCS control host connected to the signal converter to receive and display CO concentration data; The execution device includes an alarm and a temperature adjustment module. The alarm is used to trigger an alarm signal according to the CO concentration threshold; the temperature adjustment module is used to adjust the temperature of the coal mill outlet according to the CO concentration threshold.

2. The pulverizing system safety monitoring and boiler combustion optimization system according to claim 1 is characterized in that: Each coal mill body is provided with two sampling probes, and the two sampling probes are arranged on two opposite sides of the separator of the coal mill body.

3. The pulverizing system safety monitoring and boiler combustion optimization system according to claim 2 is characterized in that: The CO monitoring devices are provided in three pieces, namely a first monitoring device, a second monitoring device and a third monitoring device; There are six coal mill bodies, and the primary air powder pipe corresponding to each of the five coal mill bodies is provided with a sampling probe in the first area, the second area, the third area and the fourth area respectively; wherein the first monitoring device is in communication with the twelve sampling probes of the six coal mill bodies; The second monitoring device is connected to the five sampling probes of the five primary air powder tubes under the first area and to the five sampling probes of the five primary air powder tubes under the second area; The third monitoring device is connected to the five sampling probes of the five primary air powder tubes under the third area and to the five sampling probes of the five primary air powder tubes under the fourth area.

4. The pulverizing system safety monitoring and boiler combustion optimization system according to claim 1 is characterized in that: The system also includes a burner, which includes a burner body and a burner elbow, and the outlet of the primary air powder hose is connected to the burner elbow; wherein the distance between the sampling probe corresponding to the primary air powder hose and the burner elbow is between 500 mm and 700 mm.

5. A method for safety monitoring of a pulverizing system and optimization of boiler combustion, characterized in that: The method comprises: Step S1: Collecting CO concentration data in real time through sampling probes distributed on the coal mill body and the primary air powder pipe, and transmitting the data to the DCS control host; Step S2: Calculate the average CO concentration under normal operation and adjust it upward to generate an alarm threshold; Step S3: When the current CO concentration is less than or equal to the alarm threshold, it is determined to be safe and the temperature adjustment module performs a temperature increase operation; when the current CO concentration is greater than the alarm threshold, the alarm is triggered; Step S4: In a safe state, the temperature regulating module is used to adjust the ratio of cold and hot primary air to increase the outlet temperature of the coal mill body, and the CO concentration change trend is recorded every 1°C increase in temperature; Step S5: If the CO concentration exceeds the alarm threshold during the heating process, stop heating and return to the initial temperature; or, if the CO concentration exceeds the alarm threshold during the heating process, continue ventilation and purge or stop grinding for inspection until the CO concentration is ≤ the alarm threshold and lasts for at least 1 hour.

6. The method for safety monitoring of a pulverizing system and optimization of boiler combustion according to claim 5, characterized in that: Calculating the average CO concentration under normal operation and adjusting it upward to generate an alarm threshold includes: Collect at least 7 days of normal unit operation data and calculate the daily average CO concentration; The daily average value is adjusted upward by 50 ppm as the alarm threshold; When the current CO concentration exceeds the alarm threshold and lasts for ≥10 minutes, an alarm is triggered.

7. The method for safety monitoring of a pulverizing system and optimization of boiler combustion according to claim 5, characterized in that: The method further comprises step S6: According to the stability of CO concentration after temperature increase, the reduction value of boiler exhaust gas temperature ΔT and coal consumption reduction value ΔQ are calculated. The formula is: ΔT = 3.6×(ΔT_initial / 10)°C, ΔQ = 0.8×(ΔT_initial / 10)g / Kwh, where ΔT_initial is the initial temperature rise.

8. The method for safety monitoring of a pulverizing system and optimizing boiler combustion according to claim 5, characterized in that: The continuous ventilation and purge or grinding inspection includes: Start the standby fan to force ventilation on the primary air-powder pipe and purge the inside of the coal mill body with inert gas; alternatively, manually clean the accumulated powder and check the sealing after stopping the mill.

9. The method for safety monitoring of a pulverizing system and optimizing boiler combustion according to claim 5, characterized in that: The temperature regulating controller controls the outlet temperature by adjusting the ratio of the opening of the cold and hot primary air doors of the coal mill. The heating rate is 1°C / minute, and the maximum temperature rise does not exceed 20°C of the initial temperature.

10. The method for safety monitoring of a pulverizing system and optimization of boiler combustion according to claim 5, characterized in that: The gas sensor is an electrochemical CO sensor with a measuring range of 0-500 ppm, an accuracy of ±5 ppm, and a response time of ≤30 seconds.

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