Tangent circle combustion boiler capable of eliminating residual rotation momentum at hearth outlet

Abstract

The invention provides a tangential combustion boiler capable of eliminating residual rotation momentum at a hearth outlet, and relates to the technical field of coal-fired power plant boiler flow field optimization and smoke temperature deviation treatment. Comprising a hearth, a multi-layer corner-type arranged direct-flow burner, a wall-type arranged turbulent burner, a pulverized coal connecting pipe, a plurality of stop valves, a pulverized coal pipeline, a temperature measuring system and a flow velocity measuring system. The multi-layer angle-type arranged direct-flow combustors and the wall-type arranged rotational-flow combustors are arranged, and the two sets of devices are used in a matched mode. Therefore, the problems that in an existing corner tangential combustion boiler, due to smoke residual rotation, over-temperature and abrasion of a tube panel cause large interference on safe operation of the boiler, and local dust accumulation of a horizontal flue, a furnace arch, a tail vertical shaft and other parts can be caused by the difference of smoke flow velocity distribution are effectively solved; the normal operation of the denitration devices on the two sides is influenced.

Description

Technical Field

[0001] The present invention relates to the technical field of optimizing the flow field of coal-fired power plant boilers and controlling the flue gas temperature deviation, and specifically relates to a tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet. Background Technique

[0002] The tangentially fired boiler is the most widely used, has the best combustion uniformity, and the highest reliability among pulverized coal boiler equipment forms at present. However, due to its tangential combustion organization method, even with measures such as reverse tangential overfire air, there is still a very large residual rotational momentum of flue gas at the furnace outlet of most tangentially fired boilers. This residual rotational momentum of flue gas is manifested as a huge difference in flow velocity and temperature between the left and right sides of the furnace at each convective heating surface. Further, it will greatly affect the heat transfer uniformity between the left and right sides of each convective heating surface, causing some tube screens to overheat, and at the same time, it will also exacerbate the wear of the tube screens in the high-flow velocity area. It can be said that the overheating and wear of the tube screens caused by the residual rotation of flue gas have already caused quite a lot of interference to the safe operation of the boiler. In addition, the difference in the flue gas flow velocity distribution will also cause local ash accumulation in parts such as the horizontal flue, the flame-retarding angle, and the tail shaft, and affect the normal operation of the denitration devices on both sides. Therefore, in view of the above current situation, there is an urgent need to develop a tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet, so as to overcome the deficiencies in current practical applications. Summary of the Invention

[0003] The present invention provides a tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet, so as to solve the technical problems raised in the above background technique: the overheating and wear of the tube screens caused by the residual rotation of flue gas in the existing tangentially fired boilers have already caused quite a lot of interference to the safe operation of the boiler, and the difference in the flue gas flow velocity distribution will also cause local ash accumulation in parts such as the horizontal flue, the flame-retarding angle, and the tail shaft, and affect the normal operation of the denitration devices on both sides.

[0004] To solve the above technical problems, the present invention discloses a tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet, including: a furnace;

[0005] Multiple layers of corner-mounted direct-flow burners, which are arranged at the lower part of the furnace;

[0006] Wall-mounted swirl burners, and there are 2 layers of wall-mounted swirl burners arranged up and down at the upper part of the furnace;

[0007] A pulverized coal connection pipe for connecting the top-layer direct-flow burner and the lower-layer swirl burner;

[0008] Multiple stop valves, which are installed on the pulverized coal connection pipe and are used to select and control the pulverized coal passing through the burners;

[0009] A pulverized coal pipeline, used to connect each burner and the corresponding coal mill;

[0010] A temperature measurement system, which is installed on the convective heating surface;

[0011] A flow velocity measurement system, which is installed in the flue at the furnace outlet.

[0012] Preferably, the stop valve on the pulverized coal connection pipe adopts a pneumatic slide gate.

[0013] Preferably, the rotation direction of the swirl burner is opposite to the tangential rotation direction generated by the lower-level direct-flow burner; when the tangential circle of the direct-flow burner is counterclockwise, the swirl direction of the swirl burner is from left to right, and when the tangential circle of the direct-flow burner is clockwise, the swirl direction of the swirl burner is from right to left.

[0014] Preferably, the top-layer direct-flow burner is adjacent to the lower-layer swirl burner and is located at the same elevation.

[0015] Preferably, the temperature measurement system includes:

[0016] A plurality of temperature sensors, which are installed on the convective heating surface and are used to sense the temperature of the convective heating surface;

[0017] A first signal conditioning circuit, which is electrically connected to the temperature sensor and is used to amplify, filter, and linearize the electrical signal output by the temperature sensor;

[0018] A first data acquisition system, which is electrically connected to the first signal conditioning circuit and is used to convert the analog signal output by the first signal conditioning circuit into a digital signal;

[0019] A first data transmission and display module, which is electrically connected to the first data acquisition system and is used to transmit the digital signal to the control system and perform real-time display.

[0020] Preferably, the flow velocity measurement system includes:

[0021] A flow velocity sensor array, which consists of a plurality of pitot tubes. The pitot tubes are installed on the cross-section of the flue at the furnace outlet and are used to sense the flue gas flow velocity in the flue and output a pressure difference related to the flue gas flow velocity;

[0022] A differential pressure transmitter, which is connected to the pitot tube one by one and is used to convert the pressure difference into an electrical signal;

[0023] A second signal conditioning circuit, which is electrically connected to the differential pressure transmitter and is used to amplify, filter, and linearize the electrical signal;

[0024] The second data acquisition system, electrically connected to the second signal conditioning circuit, is configured to convert the analog signal output by the second signal conditioning circuit into a digital signal;

[0025] The data processing unit, connected to the second data acquisition system, is configured to receive the digital signal and calculate the flue gas flow rate, generate a flow rate distribution map of the flue gas cross-section, and calculate the average flow rate according to the digital signal;

[0026] The second data transmission and display module, connected to the second data processing unit, is configured to transmit the flow rate distribution map and the average flow rate value to the control system and perform real-time display.

[0027] Preferably, the coal mill is a steel ball coal mill, and further includes:

[0028] A rotational speed sensor, configured to detect the operating rotational speed of the steel ball coal mill cylinder;

[0029] A flow rate sensor, configured to detect the flow rate of the gas flowing into the swirl burner;

[0030] A controller and an alarm, the controller being electrically connected to the rotational speed sensor, the flow rate sensor, and the alarm.

[0031] Preferably, the controller controls the operation of the alarm based on the rotational speed sensor and the flow rate sensor, including the following steps:

[0032] Step 1: According to formula (1) and the detection value of the rotational speed sensor, calculate the actual ventilation volume Q of the steel ball coal mill:

[0033]

[0034] Where M is the volume of the steel ball coal mill cylinder, S is the detection value of the rotational speed sensor, r is the inner diameter of the steel ball coal mill cylinder, μ is the fineness of the pulverized coal prepared by the steel ball coal mill, λ is the grindability index of the coal fed into the furnace by the steel ball coal mill, m is the mass of the steel balls loaded in the steel ball coal mill, ρ g is the bulk density of the steel balls in the steel ball coal mill cylinder;

[0035] Step 2: The actual ventilation volume Q of the steel ball coal mill is the same as the ventilation volume of the swirl burner. According to the following formula (2) and the detection value of the flow rate sensor, calculate the actual swirl intensity P of the swirl burner. The controller compares the actual swirl intensity P of the swirl burner with the preset swirl intensity range. When the actual swirl intensity is lower than the preset swirl intensity range, the controller controls the alarm to give an alarm:

[0036]

[0037] Where ρ qρ is the density of the gas flow in the swirl burner, V is the detection value of the flow velocity sensor, R is the rotation radius of the rotating gas flow in the swirl burner, D is the throat diameter of the swirl burner, T is the axial momentum moment of the swirl burner, and π is taken as 3.14. Brief Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 It is a schematic diagram of the installation structure of a tangential combustion boiler provided by an embodiment of the present invention;

[0040] Figure 2 It is a simplified installation diagram of the swirl direction of the pulverized coal air flow provided by an embodiment of the present invention.

[0041] Reference Signs:

[0042] 1. Swirl burner; 2. Direct current burner; 3. Coal mill; 4. Pulverized coal connection pipe; 5. Stop valve; 6. Pulverized coal pipeline. Detailed Embodiments

[0043] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0044] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions and technical features between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0045] The present invention provides the following embodiments

[0046] Example 1

[0047] An embodiment of the present invention provides a tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet, as Figure 1-2 shown, comprising: a furnace;

[0048] A multi-layer angularly arranged direct current burner 2, and the multi-layer angularly arranged direct current burner 2 is arranged at the lower part of the furnace;

[0049] A wall-mounted swirling burner 1, and two upper and lower layers of wall-mounted swirling burners 1 are arranged at the upper part of the furnace;

[0050] A pulverized coal connection pipe 4 for connecting the top-layer direct current burner 2 and the lower-layer swirling burner 1;

[0051] A plurality of stop valves 5 are installed on the pulverized coal connection pipe 4 for selecting and controlling the pulverized coal passing through the burner;

[0052] A pulverized coal pipeline 6 for connecting each burner and the corresponding coal mill 3;

[0053] A temperature measurement system, and the temperature measurement system is installed on the convective heating surface;

[0054] A flow velocity measurement system, and the flow velocity measurement system is installed in the furnace outlet flue.

[0055] The beneficial effects of the above technical solution are as follows: By arranging the multi-layer angularly arranged direct current burner 2 and the wall-mounted swirling burner 1 and using the two sets of devices in cooperation, the present invention effectively improves the problems raised in the background technology: The overheating and wear of the tube screen caused by the residual rotation of the flue gas in the existing tangentially fired boiler have caused quite a lot of interference to the safe operation of the boiler, and the difference in the flue gas flow velocity distribution will also cause local ash accumulation in parts such as the horizontal flue, the flame deflecting angle, and the tail shaft, and affect the normal operation of the denitration devices on both sides.

[0056] Example 2

[0057] On the basis of Example 1, as Figure 1-2 shown, for the tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet, the stop valve 5 on the pulverized coal connection pipe 4 adopts a pneumatic slide gate.

[0058] Optionally, the rotation direction of the swirling burner 1 is opposite to the tangential rotation direction generated by the lower direct current burner 2; when the tangent circle of the direct current burner 2 is counterclockwise, the swirl direction of the swirling burner 1 is from left to right, and when the tangent circle of the direct current burner 2 is clockwise, the swirl direction of the swirling burner 1 is from right to left.

[0059] Optionally, the top-layer direct current burner 2 is adjacent to the lower-layer swirl burner 1 and at the same elevation.

[0060] Optionally, the temperature measurement system includes:

[0061] A plurality of temperature sensors installed on the convective heating surface for sensing the temperature of the convective heating surface;

[0062] A first signal conditioning circuit electrically connected to the temperature sensors for amplifying, filtering, and linearizing the electrical signals output by the temperature sensors;

[0063] A first data acquisition system electrically connected to the first signal conditioning circuit for converting the analog signals output by the first signal conditioning circuit into digital signals;

[0064] A first data transmission and display module electrically connected to the first data acquisition system for transmitting the digital signals to the control system and displaying them in real time.

[0065] Optionally, the flow rate measurement system includes:

[0066] An array of flow rate sensors composed of a plurality of pitot tubes installed on the cross-section of the flue at the furnace outlet for sensing the flue gas flow rate in the flue and outputting a pressure difference related to the flue gas flow rate;

[0067] A differential pressure transmitter connected to each pitot tube one by one for converting the pressure difference into an electrical signal;

[0068] A second signal conditioning circuit electrically connected to the differential pressure transmitter for amplifying, filtering, and linearizing the electrical signal;

[0069] A second data acquisition system electrically connected to the second signal conditioning circuit for converting the analog signals output by the second signal conditioning circuit into digital signals;

[0070] A data processing unit connected to the second data acquisition system for receiving the digital signals and calculating the flue gas flow rate, generating a flow rate distribution map of the flue cross-section, and calculating the average flow rate according to the digital signals;

[0071] A second data transmission and display module connected to the second data processing unit for transmitting the flow rate distribution map and the average flow rate value to the control system and displaying them in real time.

[0072] The working principle of the above technical solution is as follows: Along the height direction of the furnace, this tangential combustion boiler has 4 - 5 layers of direct - flow burners 2 arranged at corners and 2 layers of tangential - flow burners 1 arranged on the walls. The direct - flow burners 2 are used to generate swirl to strengthen the mixing and combustion in the main combustion zone, improving the combustion efficiency. The tangential - flow burners 1 are arranged above the direct - flow burners and are used to eliminate the residual rotational momentum of the flue gas generated by the lower - layer tangential combustion.

[0073] During the operation of the boiler, according to the temperature measurement system and the flow velocity measurement system, the strength of the residual rotational momentum of the flue gas at the furnace outlet is monitored. If the deviation of the flue gas flow rate or the heat transfer amount of the heating surface on the left and right sides is less than 5%, then 4 - 5 layers of direct - flow burners and 1 layer of tangential - flow burner 1 are operated, and the pulverized coal enters the furnace for combustion through the top - layer direct - flow burner 2. If the deviation of the flue gas flow rate or the heat transfer amount of the heating surface on the left and right sides is greater than 5%, then 3 - 4 layers of direct - flow burners 2 and 2 layers of tangential - flow burners 1 are operated, and the pulverized coal enters the furnace for combustion through the lower - layer tangential - flow burner 1. Whether the pulverized coal passes through the top - layer direct - flow burner 2 or the lower - layer tangential - flow burner 1 is selected and controlled by two stop valves 5 on the pulverized coal connection pipe.

[0074] The beneficial effects of the above technical solution are as follows:

[0075] Eliminating residual rotational momentum: Through the design of reverse - rotating airflows, the rotational momentum of the flue gas is effectively eliminated, improving the uniformity of flue gas flow.

[0076] Improving combustion efficiency: By optimizing the burner arrangement and operation mode, ensuring the full combustion of pulverized coal, and improving the combustion efficiency and thermal efficiency.

[0077] Flexible control: Through real - time monitoring and dynamic adjustment, flexible control and optimization of boiler operation are achieved.

[0078] Stable and safe: By reducing flue gas deviation and non - uniform flow, the stability and safety of boiler operation are improved.

[0079] Reducing costs: By reducing fuel consumption and emissions, the operation cost of the boiler and the environmental impact are reduced.

[0080] By setting up a temperature measurement system and a flow rate measurement system, it is conducive to a more comprehensive understanding of the boiler operation status, reflecting the boiler operation status from different perspectives, having a more comprehensive understanding of the boiler operation conditions, promptly discovering potential problems, and more effectively optimizing the boiler operation control. Temperature and flow rate data can provide a more comprehensive basis for the boiler operation control. By synergistically optimizing the temperature and flow rate, the combustion efficiency, thermal efficiency, and operation stability of the boiler can be more effectively improved. Through the data of the temperature measurement system and the flow rate measurement system, the strength of the residual rotational momentum of the flue gas at the furnace outlet can be more accurately judged, which helps to more precisely control the operation of the swirl burner and achieve the best swirl elimination effect, providing more comprehensive support for the energy conservation and consumption reduction of the boiler. Through the synergistic optimization of temperature and flow rate data, the flue gas temperature can be more effectively reduced and the flue gas resistance can be decreased, achieving the energy conservation and consumption reduction of the boiler.

[0081] Example 3

[0082] Based on Embodiments 1-2, for the tangentially fired boiler for eliminating the residual rotational momentum at the furnace outlet, the coal mill 3 adopts a ball mill, and further includes:

[0083] A rotational speed sensor for detecting the working rotational speed of the ball mill cylinder.

[0084] A flow rate sensor for detecting the flow rate of the air flow passing into the swirl burner 1.

[0085] A controller and an alarm. The controller is electrically connected to the rotational speed sensor, the flow rate sensor, and the alarm.

[0086] Optionally, the controller controls the operation of the alarm based on the rotational speed sensor and the flow rate sensor, including the following steps:

[0087] Step 1: According to Formula (1) and the detection value of the rotational speed sensor, calculate the actual ventilation volume Q of the ball mill:

[0088]

[0089] where M is the volume of the ball mill cylinder, S is the detection value of the rotational speed sensor, r is the inner diameter of the ball mill cylinder, μ is the fineness of the pulverized coal prepared by the ball mill, λ is the grindability index of the coal fed into the furnace of the ball mill (the value range is 0.26 - 0.73), m is the mass of the steel balls loaded in the ball mill, and ρ g is the bulk density of the steel balls in the ball mill cylinder;

[0090] Step 2: The actual ventilation volume Q of the ball mill is the same as the ventilation volume introduced into the tangential burner 1. According to the following formula (2) and the detection value of the flow velocity sensor, calculate the actual swirl intensity P of the tangential burner 1. The controller compares the actual swirl intensity P of the tangential burner 1 with the preset swirl intensity range. When the actual swirl intensity is lower than the preset swirl intensity range, the controller controls the alarm to give an alarm:

[0091]

[0092] where ρ q is the density of the air flow through the tangential burner 1, V is the detection value of the flow velocity sensor, R is the rotation radius of the rotating air flow through the tangential burner 1, D is the throat diameter of the tangential burner 1, T is the axial momentum moment of the tangential burner 1, and π is taken as 3.14.

[0093] The beneficial effects of the above technical solution are as follows: The controller calculates the actual ventilation volume of the ball mill based on the formula (1) and the detection value of the rotational speed sensor. By comprehensively considering the volume of the ball mill cylinder, the inner diameter of the ball mill cylinder, the fineness of the pulverized coal prepared by the ball mill, the grindability index of the coal entering the furnace of the ball mill, the loading mass of the steel balls in the ball mill, and the packing density of the steel balls in the ball mill cylinder, the calculation result is more accurate and reliable;

[0094] Then, according to formula (2) and the detection value of the flow velocity sensor, and comprehensively considering the density of the air flow through the tangential burner 1, the rotation radius of the rotating air flow through the tangential burner 1, the throat diameter of the tangential burner 1, and the axial momentum moment of the tangential burner 1, calculate the actual swirl intensity of the tangential burner 1.

[0095] The controller controls the operation of the rotational speed sensor and the flow velocity sensor. The controller compares the actual swirl intensity of the tangential burner 1 with the preset swirl intensity range. When the actual swirl intensity is lower than the preset swirl intensity range, the controller controls the alarm to give an alarm, reminding the staff to repair or replace the tangential burner 1 in time, thus meeting the needs of users for this kind of tangential combustion boiler that eliminates the residual rotational momentum at the furnace outlet.

[0096] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet, characterized in that: include: furnace; A multi-layer angularly arranged direct current burner (2), wherein the multi-layer angularly arranged direct current burner (2) is arranged at the lower part of the furnace; The swirl burners (1) are arranged in a wall-type manner, and the upper part of the furnace is provided with two layers of swirl burners (1) arranged in a wall-type manner; A pulverized coal communication pipe (4) for communicating the top-layer direct-flow burner (2) and the lower-layer swirl burner (1); A plurality of stop gates (5) are installed on the pulverized coal communication pipe (4) and are used to select and control the pulverized coal passing through the burner; A pulverized coal pipeline (6) for connecting each burner and a corresponding coal mill (3); A temperature measurement system, wherein the temperature measurement system is installed on the convection heating surface; A flow rate measuring system is installed in the flue at the furnace outlet.

2. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet according to claim 1, characterized in that: The stop door (5) on the pulverized coal communication pipe (4) is a pneumatic plug-in door.

3. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet according to claim 1, characterized in that: The rotation direction of the swirl burner (1) is opposite to the rotation direction of the tangential circle generated by the lower direct current burner (2); when the tangential circle of the direct current burner (2) is in the counterclockwise direction, the rotation direction of the swirl burner (1) is from left to right; when the tangential circle of the direct current burner (2) is in the clockwise direction, the rotation direction of the swirl burner (1) is from right to left.

4. A tangentially fired boiler for eliminating residual rotational momentum at a furnace outlet according to claim 1, characterized in that: The top-layer direct-current burner (2) is adjacent to the lower-layer swirl burner (1) and is located at the same elevation.

5. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet according to claim 1, characterized in that: The temperature measurement system comprises: A plurality of temperature sensors, each of which is mounted on the convection heating surface and is used to sense the temperature of the convection heating surface; a first signal conditioning circuit, electrically connected to the temperature sensor, and configured to amplify, filter and linearize the electrical signal output by the temperature sensor; a first data acquisition system, electrically connected to the first signal conditioning circuit, and configured to convert the analog signal output by the first signal conditioning circuit into a digital signal; The first data transmission and display module is electrically connected to the first data acquisition system and is used to transmit the digital signal to the control system and display it in real time.

6. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet according to claim 1, characterized in that: The flow rate measurement system comprises: A flow velocity sensor array, consisting of a plurality of Pitot tubes, which are installed on the flue section at the furnace outlet, and are used to sense the flue gas flow velocity in the flue and output a pressure difference related to the flue gas flow velocity; A differential pressure transmitter, connected to the Pitot tube in a one-to-one correspondence, for converting the pressure difference into an electrical signal; a second signal conditioning circuit, electrically connected to the differential pressure transmitter, for amplifying, filtering and linearizing the electrical signal; a second data acquisition system, electrically connected to the second signal conditioning circuit, and configured to convert the analog signal output by the second signal conditioning circuit into a digital signal; a data processing unit connected to the second data acquisition system, configured to receive the digital signal, and calculate the flue gas flow velocity, generate a flow velocity distribution diagram of the flue cross section, and calculate an average flow velocity according to the digital signal; The second data transmission and display module is connected to the second data processing unit and is used for transmitting the flow velocity distribution diagram and the average flow velocity value to the control system and displaying them in real time.

7. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet according to claim 1, characterized in that: The coal mill (3) is a steel ball coal mill, and further comprises: Speed ​​sensor, used to detect the working speed of the steel ball coal mill cylinder; A flow rate sensor, used for detecting the flow rate of the airflow entering the swirl burner (1); A controller and an alarm, wherein the controller is electrically connected with the rotation speed sensor, the flow rate sensor and the alarm.

8. A tangentially fired boiler for eliminating residual rotational momentum at the furnace outlet according to claim 7, characterized in that: The controller controls the alarm to work based on the rotation speed sensor and the flow rate sensor, including the following steps: Step 1: According to formula (1) and the speed sensor detection value, calculate the actual ventilation volume Q of the ball mill: Where M is the cylinder volume of the ball mill, S is the speed sensor detection value, r is the inner diameter of the ball mill cylinder, μ is the fineness of the coal powder prepared by the ball mill, λ is the grindability index of the coal fed into the ball mill, m is the loading mass of the steel balls in the ball mill, ρ g is the packing density of steel balls in the cylinder of the steel ball coal mill; Step 2: The actual ventilation volume Q of the steel ball mill is the same as the ventilation volume introduced into the swirl burner (1). According to the following formula (2) and the detection value of the flow velocity sensor, the actual swirl intensity P of the swirl burner (1) is calculated. The controller compares the actual swirl intensity P of the swirl burner (1) with the preset swirl intensity range. When the actual swirl intensity is lower than the preset swirl intensity range, the controller controls the alarm to sound an alarm: where ρ q is the density of the airflow passing through the swirl burner (1), V is the detection value of the flow velocity sensor, R is the rotation radius of the swirl airflow passing through the swirl burner (1), D is the throat diameter of the swirl burner (1), T is the axial momentum moment of the swirl burner (1), and π is taken as 3.14.

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