Monitoring system and monitoring method for power plant boiler powder feeding pipeline outlet deviation

Abstract

The invention discloses a power plant boiler powder feeding pipeline outlet deviation monitoring system and method. The method comprises the steps that the outlet pressure Pi, the outlet temperature ti, the sectional area Ai of the outlet pressure measurement position and the pulverized coal combustion consumption Q of a powder feeding pipeline are obtained; the deviation value Di of the outlet air speed and the deviation value tau i of the pulverized coal concentration are obtained through calculation; obtaining a determination parameter K, K = Di * tau i, when Kgt; and 1.3, deviation prompting is carried out. The deviation of combustors on the same side of the boiler can be timely and quantitatively known and mastered, when the deviation exceeds the limit, an alarm can be given out by integrating the deviation of the pulverized coal concentration and the wind speed of an outlet, when it is judged that parameters are lower than a threshold value, automatic adjustment can be conducted, and the combustion efficiency of the boiler can be improved by reducing the output deviation of the combustors; the frequency of occurrence of working conditions influencing safety, such as overtemperature of a heating surface and slag bonding of a hearth, is reduced, and quantitative guidance can be provided for production management decisions.

Description

Technical Field

[0001] The present application relates to a monitoring system and method for outlet deviation of a power plant boiler pulverized coal delivery pipeline. Background Art

[0002] In a power plant's direct-blowing pulverized coal system, hot primary air mixes with pulverized coal from the mill and is transported via a pulverized coal delivery pipe to the boiler furnace for combustion. Therefore, air velocity deviation at the pulverized coal delivery pipe outlet directly affects the combustion of the pulverized coal in the furnace, thereby impacting the safety and economic efficiency of boiler operation and the flexibility of generator set operation. Smaller deviations at the pulverized coal delivery pipe outlet result in more stable pulverized coal combustion in the boiler, while larger deviations degrade furnace combustion stability. Excessive deviations at the pipe outlet not only affect boiler thermal efficiency but can also cause localized wall overheating, impacting the boiler's safe and economical operation.

[0003] Therefore, real-time monitoring of the wind speed deviation at the outlet of the boiler powder delivery pipe can not only help us understand the stability of fuel combustion in the furnace in a timely manner, but also provide timely warnings when the wind speed deviation at the pipe outlet is too large, providing guidance for subsequent reduction of the wind speed deviation at the pipe outlet, and avoiding problems such as unstable fuel combustion until flameout, local wall overheating, and generator set shutdown caused by excessive deviation of the wind speed at the pipe outlet. Summary of the Invention

[0004] In order to solve the above problems, the present application proposes a method for monitoring the outlet deviation of the power plant boiler powder delivery pipeline, obtaining the outlet pressure P of the powder delivery pipeline. i , unit is Pa, outlet temperature t i , unit is ℃, cross-sectional area A at the outlet pressure measurement point i , unit is m 2 , pulverized coal combustion consumption Q, unit is kg / s;

[0005] Calculate the deviation value D of the outlet wind speed i , the deviation value of coal powder concentration τ i ;

[0006] Get the judgment parameter K, K=|D i *τ i |, when K>1.3, a deviation prompt is issued. This application can timely and quantitatively understand and grasp the deviation of the burners on the same side of the boiler. When the deviation exceeds the limit, an alarm can be issued by comprehensively considering the deviation of pulverized coal concentration and outlet wind speed. When the judgment parameter is below the threshold, it can automatically adjust. By reducing the burner output deviation, the boiler combustion efficiency can be improved, and the frequency of safety-impacting conditions such as overheating of the heating surface and furnace slagging can be reduced. This can provide quantitative guidance for production management decisions.

[0007] Preferably, intermediate parameters are calculated, including the outlet wind speed V I , unit is m / s, outlet air volume F i , unit is m 3 / s;

[0008]

[0009] α is the altitude correction coefficient for wind speed at the duct outlet, β is the powder hose position correction coefficient, and ρ is the standard air density;

[0010] where a = 1 + 7 × 10 -9 ×H 2 -1.15×10 -4 ×H;

[0011] H is the altitude of the powder delivery pipeline, in meters;

[0012] β is set to 1 for the front wall powder hose and between 1 and 1.1 for the rear wall powder hose depending on the furnace type;

[0013] F i =V i ×A i ;

[0014] Calculate the average pulverized coal concentration δ a , unit is kg / kg:

[0015]

[0016] Preferably, when the powder hose is located at the rear wall, the value of β is: 1 for tower boiler, 1.05 for π-type square tangential boiler, 1.08 for π-type front and rear wall opposing boiler, and 1.1 for π-type W-flame boiler.

[0017] Preferably, the deviation value D of the outlet wind speed is calculated I , the deviation value of coal powder concentration τ i

[0018]

[0019] n is the total number of pulverized coal delivery pipes. This application uses a comprehensive calculation and judgment based on the deviation values ​​of the outlet wind speed and the pulverized coal concentration. The judgment parameters obtained using this calculation method are more accurate, which not only has reference value for subsequent judgment parameters, but also has a good reference significance for how to make subsequent adjustments.

[0020] Preferably, the maximum deviation value D of the outlet wind speed of the powder delivery pipeline is obtained max ,

[0021] D max =max{Di};

[0022] Get the maximum deviation value τ of coal powder concentration max ,

[0023] T max =max{τ i When calculating the judgment parameter K, K=|D max *τ max Using the maximum value as the calculation base can better determine the reliability of deviation judgment in multiple powder feeding pipelines.

[0024] Preferably, the outlet pressure P i It is measured by the pressure sensor installed at the outlet of the powder delivery pipeline;

[0025] The outlet temperature t i It is measured by the temperature sensor installed at the outlet of the powder delivery pipeline.

[0026] Preferably, the measuring positions of the pressure sensor and the temperature sensor are set at the center position of the upstream pipeline 250-350 mm from the outlet of the powder delivery pipeline.

[0027] Preferably, it also includes a wireless signal receiver, which is connected to the pressure sensor signal through a pressure transmitter and to the temperature sensor signal through a temperature transmitter; the wireless signal receiver is connected to the data processing server signal through a data acquisition controller, and the data processing server is connected to the computer signal in the control room.

[0028] On the other hand, this application also proposes a monitoring system for the outlet deviation of a power plant boiler pulverized coal delivery pipeline, which includes the following modules:

[0029] Signal acquisition module, used to obtain the outlet pressure P of the powder delivery pipeline i , outlet temperature t i , Cross-sectional area A at the outlet pressure measurement point i , pulverized coal combustion consumption Q;

[0030] Calculation module, used to calculate the deviation value D of the outlet wind speed i , the deviation value of coal powder concentration τ i ;

[0031] Judgment module, used to obtain the judgment parameter K, K = |D max *τ max |, when K>1.3, a deviation prompt is given.

[0032] Preferably, an alarm module is also included, which is used to obtain whether the judgment module has issued a deviation prompt, and then perform alarm processing when a deviation prompt is obtained.

[0033] This application can bring the following beneficial effects:

[0034] 1. This application can timely and quantitatively understand and grasp the deviation of the burners on the same side of the boiler. When the deviation exceeds the limit, an alarm can be issued by comprehensively considering the deviation of the coal powder concentration and the outlet wind speed. When the judgment parameter is lower than the threshold, it can be automatically adjusted. By reducing the burner output deviation, the boiler combustion efficiency can be improved, and the frequency of operating conditions that affect safety, such as overheating of the heating surface and slagging in the furnace, can be reduced. It can provide quantitative guidance for production management decisions.

[0035] 2. This application makes a comprehensive calculation and judgment through the deviation value of the outlet wind speed and the deviation value of the coal powder concentration. The judgment parameters obtained by this calculation method are more accurate, which not only has reference value for the subsequent judgment parameters, but also has a good reference significance for how to make subsequent adjustments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 is a schematic diagram of the deviation monitoring method;

[0038] Figure 2 is a schematic diagram of the deviation monitoring system;

[0039] Figure 3 This is a schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to clearly illustrate the technical features of this solution, this application is described in detail below through specific implementation methods and in conjunction with its accompanying drawings.

[0041] For deviation monitoring methods, such as Figure 1 As shown, the following steps are included:

[0042] S101. Obtain the basic parameters of the powder delivery pipeline:

[0043] Outlet pressure P i , unit is Pa, outlet temperature t i , unit is ℃, cross-sectional area A at the outlet pressure measurement point i , unit is m 2 , pulverized coal combustion consumption Q, unit is kg / s;

[0044] S102. Calculate the deviation value:

[0045] Deviation values ​​include: Deviation value D of outlet wind speedi , the deviation value of coal powder concentration τ i ;

[0046] S1021. Calculate intermediate parameters, including outlet wind speed V I , unit is m / s, outlet air volume F i , unit is m 3 / s;

[0047]

[0048] α is the altitude correction coefficient for wind speed at the duct outlet, β is the powder hose position correction coefficient, and is the standard density of air;

[0049] where a = 1 + 7 × 10 -9 ×H 2 -1.15×10 -4 ×H;

[0050] H is the altitude of the powder delivery pipeline, in meters;

[0051] β is set to 1 for the front wall powder hose and between 1 and 1.1 for the rear wall powder hose depending on the furnace type;

[0052] F i =V i ×A i ;

[0053] S1022. Calculate the average pulverized coal concentration δ a , unit is kg / kg:

[0054]

[0055] When the powder hose is located at the rear wall, the β value is: 1 for tower boiler, 1.05 for π-type square tangential boiler, 1.08 for π-type front and rear wall hedge boiler, and 1.1 for π-type W-flame boiler.

[0056] S1023. Calculate the deviation value D of the outlet wind speed I , the deviation value of coal powder concentration τ i

[0057]

[0058] n is the total number of powder delivery pipelines.

[0059] S103. Obtain the judgment parameter K and make a judgment

[0060] For the control of a single powder delivery pipeline, K=|D i *τ i |;

[0061] Get the maximum deviation value D of the outlet wind speed of the powder delivery pipeline max ,

[0062] D max =max{D i};

[0063] Get the maximum deviation value τ of coal powder concentration max ,

[0064] τ max =max{τ i}.

[0065] For monitoring of multiple powder delivery pipelines, K=|D max *τ max |, when K>1.3, a deviation prompt is given.

[0066] The outlet pressure P i It is measured by the pressure sensor installed at the outlet of the powder delivery pipeline;

[0067] The outlet temperature t i It is measured by the temperature sensor installed at the outlet of the powder delivery pipeline.

[0068] The measuring positions of the pressure sensor and the temperature sensor are set at the center position of the upstream pipeline 250-350 mm from the outlet of the powder delivery pipeline.

[0069] It also includes a wireless signal receiver, which is connected to the pressure sensor signal through a pressure transmitter and to the temperature sensor signal through a temperature transmitter; the wireless signal receiver is connected to the data processing server signal through a data acquisition controller, and the data processing server is connected to the computer signal in the control room.

[0070] For monitoring systems, such as Figure 2 As shown, it includes the following modules:

[0071] Signal acquisition module 201, used to obtain the outlet pressure P of the powder delivery pipeline i , outlet temperature t i , Cross-sectional area A at the outlet pressure measurement point i , pulverized coal combustion consumption Q;

[0072] Calculation module 202, used to calculate the deviation value D of the outlet wind speed i , the deviation value of coal powder concentration τ i ;

[0073] The judgment module 203 is used to obtain the judgment parameter K, K = |D max *τ max |, when K>1.3, a deviation prompt is given.

[0074] The invention also includes an alarm module 204, which is used to obtain whether the judgment module has issued a deviation prompt, and then perform an alarm process when a deviation prompt is obtained.

[0075] When used specifically, Figure 3 As shown, an embodiment of the present invention provides a method for monitoring the outlet deviation of a power plant boiler pulverized coal delivery pipeline, comprising the following steps:

[0076] 1) According to the collection frequency set by the data acquisition controller, the data processing server calculates the outlet wind speeds V1, V2, V3, and V4 of the powder delivery pipes No. 1 to No. 4 at a frequency of 1 time / min;

[0077] 2) Calculate the average wind speed V at the outlet of powder delivery pipes No. 1 to No. 4 a ;

[0078] 3) Calculate the outlet air volumes F1, F2, F3, and F4 of powder delivery pipes No. 1 to No. 4;

[0079] 4) Calculate the average pulverized coal concentration δ at the outlet of pulverized coal delivery pipelines No. 1 to No. 4 a ;

[0080] 5) Calculate the deviation values ​​D1, D2, D3, and D4 of the outlet wind speed of powder delivery pipes No. 1 to No. 4;

[0081] 6) Calculate the deviation values ​​τ1, τ2, τ3, and τ4 of the pulverized coal concentration at the outlets of pulverized coal delivery pipelines No. 1 to No. 4;

[0082] 7) Calculate the maximum deviation value D of the outlet wind speed of the powder delivery pipes No. 1 to No. 4 max ;

[0083] 8) Calculate the maximum deviation value τ of the pulverized coal concentration at the outlet of pulverized coal delivery pipelines No. 1 to No. 4 max .

[0084] The calculation formula for the outlet wind speeds V1, V2, V3, and V4 of the powder delivery pipes No. 1 to No. 4 is:

[0085] α=1+7×10 -9 ×H 2 -1.15×10 -4 ×H; where V1, V2, V3, and V4 are the outlet wind speeds of powder delivery pipes No. 1 to No. 4, α is the altitude correction coefficient for the outlet wind speed, β is the outlet wind speed deviation correction coefficient, P1, P2, P3, and P4 are the outlet pressures of powder delivery pipes No. 1 to No. 4, respectively, ρ0 is the standard air density, t1, t2, t3, and t4 are the Celsius temperatures of the airflow at the outlet of powder delivery pipes No. 1 to No. 4, respectively, and H is the altitude of the powder delivery pipe.

[0086] The average wind speed V at the outlet of the No. 1 to No. 4 powder delivery pipelines a The calculation formula is:

[0087]

[0088] Among them, V1, V2, V3, and V4 are the outlet wind speeds of powder delivery pipes No. 1 to No. 4.

[0089] The calculation formula for the outlet air volume F1, F2, F3, and F4 of the powder delivery pipes No. 1 to No. 4 is:

[0090] F1=V1×A1;

[0091] F2=V2×A2;

[0092] F3=V3×A3;

[0093] F4=V4×A4;

[0094] Among them, V1, V2, V3, and V4 are the outlet wind speeds of No. 1-4 powder delivery pipelines, and A1, A2, A3, and A4 are the cross-sectional areas of the circular cross-sections of the pipelines where the pressure sensors of No. 1-4 powder delivery pipelines are installed.

[0095] The average pulverized coal concentration at the outlet of the No. 1 to No. 4 pulverized coal delivery pipelines δ a The calculation formula is:

[0096]

[0097] Among them, F1, F2, F3, and F4 are the outlet air volumes of the pulverized coal delivery pipes No. 1 to 4, and Q is the pulverized coal fuel consumption of the pulverized coal burner connected to the pulverized coal delivery pipes No. 1 to 4.

[0098] The calculation formula for the deviation values ​​D1, D2, D3, and D4 of the outlet wind speed of the powder delivery pipes No. 1 to No. 4 is:

[0099]

[0100] Among them, V1, V2, V3, and V4 are the outlet wind speeds of No. 1 to No. 4 powder delivery pipes, V a is the average wind speed at the outlet of powder delivery pipes No. 1 to No. 4, and |*| represents the absolute value of the internal value.

[0101] The calculation formula for the deviation values ​​τ1, τ2, τ3, and τ4 of the pulverized coal concentration at the outlets of the No. 1 to No. 4 pulverized coal delivery pipelines is:

[0102]

[0103]

[0104] Among them, F1, F2, F3, and F4 are the air volumes at the outlets of the pulverized coal delivery pipes No. 1 to No. 4, Q is the pulverized coal fuel consumption of the pulverized coal burner connected to the pulverized coal delivery pipes No. 1 to No. 4, and δ a It is the average concentration at the outlet of powder delivery pipes No. 1 to No. 4, and |*| represents the absolute value of the internal value.

[0105] The maximum deviation value D of the outlet wind speed of the powder delivery pipe No. 1 to No. 4 max The calculation formula is:

[0106] D max =max{D1,D2,D3,D4}

[0107] Among them, D1, D2, D3, and D4 are the wind speed deviation values ​​at the outlets of powder delivery pipes No. 1 to No. 4, and max{*,*} represents the maximum value among the internal values.

[0108] The maximum deviation value τ of the coal powder concentration at the outlet of the No. 1 to No. 4 pulverized coal delivery pipeline max The calculation formula is:

[0109] τ max =max{τ1,τ2,τ3,τ4}

[0110] Among them, τ1, τ2, τ3, and τ4 are the deviation values ​​of the coal powder concentration at the outlets of the pulverized coal delivery pipelines No. 1 to No. 4, and max{, *} represents the maximum value among the internal values.

[0111] Get the judgment parameter K, K=|D max *τ max |, when K>1.3, deviation prompt and alarm will be issued.

[0112] The pressure sensor 1 and temperature sensor 2 are arranged at the center position of the upstream pipeline 300mm of the powder feeding pipeline outlet No. 1 9, the powder feeding pipeline outlet No. 2 10, the powder feeding pipeline outlet No. 3 11 and the powder feeding pipeline outlet No. 4 12. The pressure sensor 1 is connected to the pressure transmitter 3 by wire, the temperature sensor 2 is connected to the temperature transmitter 4 by wire, the pressure transmitter 3 and the temperature transmitter 4 are connected to the wireless signal transmitter 5 by wire, the wireless signal transmitter 5 is connected to the wireless signal receiver 6 by wireless, the wireless signal receiver 6 is connected to the data acquisition controller 7 by wire, and the data acquisition controller 7 is connected to the data processing server 8 by wire.

[0113] The wireless signal receiver 6, data acquisition controller 7, and data processing server 8 are all placed in the centralized control room. The temperature sensors 2 are all platinum-rhodium thermocouple temperature sensors. The wireless signal transmitter 6 has a built-in lithium-ion rechargeable battery. The data processing server 8 has a built-in high-decibel buzzer alarm.

[0114] The insertion depth of the pressure sensor 1 should be no less than 300mm, the measuring sensor accuracy should be 0.1% FS, and it should have a test report from the Metrology Institute. The pressure transmitter 3 should use a transmitter with a 4-20mA current output function.

[0115] Temperature sensor 2 adopts platinum-rhodium thermocouple temperature sensor. The insertion depth of temperature sensor shall be no less than 300mm. The measurement range shall cover all temperature ranges of air-powder airflow in powder delivery pipeline. The sensor accuracy shall be 0.1% FS and it shall have the inspection report of Metrology Research Institute. Temperature transmitter 4 adopts the transmitter with 4-20mA current output function.

[0116] Pressure sensor 1 and temperature sensor 2 collect data on the pressure and air-powder airflow temperature at circular outlets 9, 10, 11, and 12 of powder delivery pipes No. 1-4. Pressure transmitter 3 and temperature transmitter 4 convert the analog signals into digital signals and transmit them to wireless signal transmitter 5. Data acquisition controller 7 controls the frequency of data collection, such as the outlet pressure and airflow temperature of the powder delivery pipes, at a set interval of 1 time per minute. The collected data is then transmitted to data processing server 8 for calculation, storage, and iteration of data, such as the outlet deviation of the powder delivery pipes. Data processing server 8 transmits the calculated pipeline outlet deviation data to a computer in the control room.

[0117] There is a communication status running program in the data processing server 8 to determine whether there is any abnormality in the communication between the data processing server and the computer. When a communication abnormality occurs, the data analysis server will flash a red light at the power supply to prompt the staff to handle it; the data processing server has a USB interface, which is convenient for regularly transferring stored data to other devices for storage; the data processing server also has a built-in high-decibel buzzer alarm. When the calculated deviation of the powder delivery pipeline outlet exceeds the set value, the alarm will sound to prompt the staff to handle it in time to avoid problems such as unstable combustion of coal powder fuel until flameout, local wall overheating, and generator set shutdown.

[0118] The data processing server 8 will calculate, store and update the pipeline outlet deviation of the data obtained by the data acquisition controller 7 at a fixed frequency according to the set time interval; if an abnormality such as communication interruption is encountered during the calculation process, the data processing server 8 will suspend the calculation of data such as deviation, and continue the calculation after the communication is restored to normal.

[0119] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0120] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline, characterized by: Get the outlet pressure P of the powder delivery pipeline i , outlet temperature t i , Cross-sectional area A at the outlet pressure measurement point i , pulverized coal combustion consumption Q; Calculate the deviation value D of the outlet wind speed i , the deviation value of coal powder concentration τ i ; Get the judgment parameter K, K=|D i *τ i |, when K>1.3, a deviation prompt is given.

2. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 1, characterized in that: Calculate intermediate parameters, including outlet wind speed V I , outlet air volume F i ; α is the altitude correction coefficient for wind speed at the duct outlet, β is the powder hose position correction coefficient, and ρ0 is the standard air density; where α = 1 + 7 × 10 -9 ×H 2 -1.15×10 -4 ×H; H is the altitude of the powder delivery pipeline; β is set to 1 for the front wall powder hose and between 1 and 1.1 for the rear wall powder hose depending on the furnace type; F i =V i ×A i ; Calculate the average pulverized coal concentration δ a :

3. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 2, characterized in that: When the powder hose is located at the rear wall, the value of β is: 1 for tower boiler, 1.05 for π-type square tangential boiler, 1.08 for π-type front and rear wall opposed boiler, and 1.1 for π-type W-flame boiler.

4. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 1, characterized in that: Calculate the deviation value D of the outlet wind speed I , the deviation value of coal powder concentration τ i n is the total number of powder delivery pipelines.

5. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 1, characterized in that: Get the maximum deviation value D of the outlet wind speed of the powder delivery pipeline max , D max =max{D i }; Get the maximum deviation value τ of coal powder concentration max , τ max =max{τ i }; When calculating the judgment parameter K, K=|D max *τ max |.

6. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 1, characterized in that: The outlet pressure P i It is measured by the pressure sensor installed at the outlet of the powder delivery pipeline; The outlet temperature t i It is measured by the temperature sensor installed at the outlet of the powder delivery pipeline.

7. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 6, characterized in that: The measuring positions of the pressure sensor and the temperature sensor are set at the center position of the upstream pipeline 250-350 mm from the outlet of the powder delivery pipeline.

8. The method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 6, characterized in that: It also includes a wireless signal receiver, which is connected to the pressure sensor signal through a pressure transmitter and to the temperature sensor signal through a temperature transmitter; the wireless signal receiver is connected to the data processing server signal through a data acquisition controller, and the data processing server is connected to the computer signal in the control room.

9. A monitoring system for implementing the method for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to any one of claims 1 to 8, characterized in that: Includes the following modules: Signal acquisition module, used to obtain the outlet pressure P of the powder delivery pipeline i , outlet temperature t i , Cross-sectional area A at the outlet pressure measurement point i , pulverized coal combustion consumption Q; Calculation module, used to calculate the deviation value D of the outlet wind speed i , the deviation value of coal powder concentration τ i ; Judgment module, used to obtain the judgment parameter K, K = |D max *τ max |, when K>1.3, a deviation prompt is given.

10. The system for monitoring outlet deviation of a power plant boiler pulverized coal delivery pipeline according to claim 9, characterized in that: Also includes: The alarm module is used to obtain whether the judgment module has issued a deviation prompt, and then perform alarm processing when a deviation prompt is obtained.

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