Primary air powder concentration measuring device and heat supply system

Abstract

The utility model provides a primary air powder concentration measuring device and a heat supply system, and belongs to the technical field of concentration measurement, and the device comprises an electrostatic loading system which is used for carrying out charge loading treatment on electrostatic ions on the surfaces of all pulverized coal particles when a power plant is in a low load state, so that all the electrostatic ions reach a saturated state; each electric charge quantity measuring sensor is used for measuring the total electric charge quantity of the static ions reaching the saturation state; each signal detection sensor is used for detecting charges generated when the static ions reaching the saturation state flow through and generating electric signals; and the controller is used for calculating the pulverized coal mass flow according to the electric signal generated by the signal detection sensor, and calculating the primary pulverized coal concentration in the pulverized coal pipeline according to the total charge quantity of the electrostatic ions and the pulverized coal mass flow. According to the scheme, the primary air powder concentration can be accurately measured under the condition of low load of the power plant.

Description

Technical Field

[0001] The present application relates to the technical field of concentration measurement, and in particular to a primary air powder concentration measuring device and a heating system. Background Art

[0002] In thermal power plant boiler operation, the uniformity of primary air and pulverized coal flow in pulverized coal burners plays a crucial role in ensuring safe and economical boiler operation. Maintaining primary and secondary air speeds is essential for achieving optimal aerodynamic conditions within the furnace and ensuring stable combustion. Currently, the primary air pulverized coal concentration measurement method primarily relies on the sensor charge method.

[0003] However, this measurement method cannot accurately measure the primary air-powder concentration under low-load conditions in power plants. The state of boiler combustion cannot be adjusted, and pulverized coal cannot be evenly distributed in each air-powder pipe. The air-powder in the boiler burner is too small or too large, resulting in low burnout or excessive oxygen combustion in some burners, causing overheating of the superheater or coking of the water-cooled wall.

[0004] Therefore, how to accurately measure the primary air dust concentration under low load conditions in power plants has become a problem that needs to be solved. Utility Model Content

[0005] The purpose of this application is to provide a primary air dust concentration measuring device and a heating system, which can solve the problem in the prior art that the primary air dust concentration cannot be accurately measured under low load conditions in power plants.

[0006] In a first aspect, an embodiment of the present application provides a primary air-powder concentration measurement device, which is disposed on the inner wall of an air-powder duct, wherein the primary air-powder is a mixture of primary air and a plurality of pulverized coal particles; the device comprises: an electrostatic loading system, a plurality of charge measurement sensors, a plurality of signal detection sensors, and a controller;

[0007] The electrostatic loading system is connected to the first charge measurement sensor, and a signal detection sensor is provided between every two charge measurement sensors. The electrostatic loading system is used to load the electrostatic ions on the surface of each pulverized coal particle with charge when the power plant is under low load, so that each electrostatic ion reaches a saturated state.

[0008] Each charge measurement sensor is used to measure the total charge of the electrostatic ions that have reached a saturated state; each signal detection sensor is used to detect the charge of the electrostatic ions that have reached a saturated state when flowing through, and generate an electrical signal;

[0009] The controller is used to calculate the coal powder mass flow rate based on the electrical signal generated by the signal detection sensor, and calculate the primary air-powder concentration in the air-powder pipeline based on the total charge of the electrostatic ions and the coal powder mass flow rate.

[0010] In a possible implementation of the first aspect, the electrostatic loading system includes: a first electrode plate and a second electrode plate;

[0011] The first electrode plate is arranged on the first side of the inner wall of the air-powder duct, and the second electrode plate is arranged on the second side of the inner wall of the air-powder duct. The first electrode plate and the second electrode plate constitute an electrostatic loading capacitor; the first side of the first electrode plate is connected to the first side of the first charge measurement sensor, and the second side of the second electrode plate is connected to the second side of the first charge measurement sensor.

[0012] In a possible embodiment of the first aspect, the electrostatic loading system includes an electrostatic loading ring; the electrostatic loading ring is nested on the inner wall of the air-powder duct, the first side of the electrostatic loading ring is connected to the first side of the first charge measurement sensor, and the second side of the electrostatic loading ring is connected to the second side of the first charge measurement sensor.

[0013] In one possible implementation of the first aspect, each charge measurement sensor includes a first type metal ring sensor;

[0014] Each first-class metal ring sensor is nested on the inner wall of the air-powder duct, the first side of the first first-class metal ring sensor is connected to the first side of the electrostatic loading system, the second side of the first first-class metal ring sensor is connected to the second side of the electrostatic loading system, and a signal detection sensor is arranged between every two first-class metal ring sensors.

[0015] In a possible implementation of the first aspect, each signal detection sensor includes a second-type metal ring sensor; each second-type metal ring sensor is nested on the inner wall of the air-powder duct, and each second-type metal ring sensor is arranged between two charge measurement sensors.

[0016] In a possible implementation of the first aspect, the device further includes an electrostatic unloading system;

[0017] Each charge measurement sensor and each signal detection sensor is arranged between the electrostatic loading system and the electrostatic unloading system; the first side of the electrostatic unloading system is connected to the first side of the last charge measurement sensor, and the second side of the electrostatic unloading system is connected to the second side of the last charge measurement sensor;

[0018] The electrostatic unloading system is used to unload the charge of the electrostatic ions on the surface of each coal powder particle so that each electrostatic ion reaches an unsaturated state.

[0019] In a possible embodiment of the first aspect, the electrostatic unloading system includes: a third electrode plate and a fourth electrode plate; the third electrode plate is arranged on the first side of the inner wall of the air-powder duct, and the fourth electrode plate is arranged on the second side of the inner wall of the air-powder duct, and the first side of the third electrode plate is connected to the first side of the last charge measurement sensor, and the second side of the fourth electrode plate is connected to the second side of the last charge measurement sensor.

[0020] In a possible implementation manner of the first aspect, the device further includes a carbon content detection sensor, which is used to detect the carbon content in each pulverized coal particle.

[0021] In a possible implementation manner of the first aspect, the device further includes a water content detection sensor, which is used to detect the water content in each pulverized coal particle.

[0022] In a second aspect, an embodiment of the present application provides a heating system, comprising: a raw coal bunker, a coal feeder, a coal mill, an air-powder duct, a pulverized coal burner, a boiler, a heating duct, and the primary air-powder concentration measuring device according to any one of the first aspects;

[0023] The raw coal bunker is used to store coal; the coal feeder is used to transport the coal in the raw coal bunker to the coal mill; the coal mill is used to grind the coal to obtain coal powder; the air-powder duct is used to transport the primary air and coal powder to the coal powder burner;

[0024] The boiler is used to heat the supply water based on the pulverized coal burner to obtain hot water; the heating pipeline is used to transport the hot water to the user; the measuring device is used to measure the primary air powder concentration in the air powder pipeline when the power plant is under low load.

[0025] In the present application, the electrostatic loading system charges the electrostatic ions on the surface of each coal powder particle when the power plant is under low load, so that each electrostatic ion is saturated. Each charge measurement sensor measures the total charge of the electrostatic ions that have reached the saturated state, and each signal detection sensor generates an electrical signal. The controller calculates the coal powder mass flow rate based on the electrical signal, and then calculates the primary air powder concentration based on the total charge of the electrostatic ions and the coal powder mass flow rate.

[0026] The application scheme can accurately measure the primary air dust concentration under low load conditions of the power plant and has strong ease of use and practicality.

[0027] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 This is a schematic diagram of the overall structure of the primary air powder concentration measuring device provided in an embodiment of the present application;

[0030] Figure 2 This is a schematic diagram of the specific structure of the primary air powder concentration measuring device provided in an embodiment of the present application;

[0031] Figure 3 It is a schematic diagram of the overall structure of the heating system provided in the embodiment of the present application. DETAILED DESCRIPTION

[0032] In the following description, specific details such as specific system structures and technologies are provided for illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obstructing the description of the present application with unnecessary details.

[0033] It will be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0034] It should also be understood that the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should be further understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0036] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0037] In addition, in the description of the present application, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0038] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present invention. Thus, phrases such as "in one embodiment," "in some embodiments," "in some other embodiments," and "in some other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0039] In the present application description, unless otherwise specified, directional words such as "up, down, left, right" generally refer to the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the invented product is usually placed when in use.

[0040] It should also be noted that, in this specification, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] In thermal power plant boiler operation, the uniformity of primary air and pulverized coal flow in pulverized coal burners plays a crucial role in ensuring safe and economical boiler operation. Maintaining primary and secondary air velocities is essential for establishing favorable aerodynamic conditions within the furnace and stable combustion. Under low plant load conditions, significant deviations from design values ​​can cause the boiler to lose its combustion state, leading to overheating of the superheater and coking of the water-cooled wall.

[0042] Currently, there are two methods for measuring and calculating primary air dust concentration: the thermal balance method and the photoelectric measurement method. The thermal balance method requires the following assumptions: the system is adiabatic before and after mixing, the temperature of the mixture after mixing is consistent, and the specific heat capacity of the pulverized coal is unaffected by changes in its composition within a certain range. The photoelectric measurement method uses a fiber optic probe to direct a light beam into the measurement area, measuring the light-induced signal from the moving particles. This signal is then converted from photoelectric to analog and then to digital, and then calculated to obtain the particle concentration value.

[0043] Currently, charge-based sensors are used, primarily in three types: insertion-type, full-section annular, and E+C space-enclosed. Insertion-type sensors, however, suffer from uneven distribution of pulverized coal concentration across the pipe cross section. For the same cross section, different insertion positions can produce different measured pulverized coal concentration data.

[0044] The annular full-section measurement sensor, due to the distribution of coal powder in the pipeline cross section, once the central flow is not in the center of the pipeline, and the annular precision measurement principle is the maximum charge potential, if the central flow deviates too much, measurement errors will also occur.

[0045] However, the measurement methods in the existing technology cannot accurately measure the primary air-powder concentration under low-load conditions in power plants. The state of boiler combustion cannot be adjusted, and coal powder cannot be evenly distributed in each air-powder pipe. The air-powder in the boiler burner is too small or too large, resulting in low burnout or excessive oxygen combustion in some burners, causing overheating of the superheater or coking of the water-cooled wall.

[0046] Therefore, how to accurately measure the primary air dust concentration under low load conditions in power plants has become a problem that needs to be solved.

[0047] In response to the above-mentioned defects, an embodiment of the present application provides a primary air-powder concentration measuring device. When the power plant is under low load, the electrostatic loading system charges the electrostatic ions on the surface of each coal powder particle to saturate each electrostatic ion. Each charge measurement sensor measures the total charge of the electrostatic ions that have reached the saturated state. Each signal detection sensor generates an electrical signal. The controller calculates the coal powder mass flow rate based on the electrical signal, and then calculates the primary air-powder concentration based on the total charge of the electrostatic ions and the coal powder mass flow rate.

[0048] The application scheme can accurately measure the primary air dust concentration under low load conditions of the power plant and has strong ease of use and practicality.

[0049] The structure of the primary air powder concentration measuring device provided in the embodiment of the present application is described below through specific examples.

[0050] See Figure 1 , Figure 1Schematic diagram of the overall structure of the primary air powder concentration measuring device 100 provided in the embodiment of the present application. Figure 1 As shown, the device 100 includes: an electrostatic charging system 110 , a plurality of charge measurement sensors 120 , a plurality of signal detection sensors 130 and a controller 140 .

[0051] In some embodiments, the electrostatic charging system 110 is connected to the first charge measurement sensor 120, and a signal detection sensor 130 is provided between every two charge measurement sensors 120. The electrostatic charging system 110 is used to charge the electrostatic ions on the surface of each pulverized coal particle when the power plant is under low load, so that each electrostatic ion reaches a saturated state.

[0052] Exemplarily, the device 100 has three charge measurement sensors 120 , and a signal detection sensor 130 is provided between the first and second charge measurement sensors 120 and between the second and third charge measurement sensors 120 .

[0053] In some embodiments, each charge measurement sensor 120 is configured to measure the total charge of saturated electrostatic ions therein, and each signal detection sensor 130 is configured to detect the charge of saturated electrostatic ions flowing therethrough, thereby generating an electrical signal.

[0054] In some embodiments, the controller 140 is used to calculate the coal powder mass flow rate based on the electrical signal generated by the signal detection sensor 130, and then calculate the primary air-powder concentration in the air-powder duct based on the total charge of the electrostatic ions and the coal powder mass flow rate.

[0055] See Figure 2 , Figure 2 This is a schematic diagram of the specific structure of the primary air powder concentration measuring device provided in the embodiment of the present application. Figure 2 As shown, the electrostatic loading system 110 includes: a first electrode plate and a second electrode plate.

[0056] In some embodiments, a first electrode plate is disposed on a first side of an inner wall of the air-powder duct, and a second electrode plate is disposed on a second side of the inner wall of the air-powder duct. The first electrode plate and the second electrode plate constitute an electrostatic loading capacitor. A first side of the first electrode plate is connected to a first side of the first charge measurement sensor 120, and a second side of the second electrode plate is connected to a second side of the first charge measurement sensor 120.

[0057] According to one embodiment of the present application, the electrostatic loading system 110 includes an electrostatic loading ring. The electrostatic loading ring is nested on the inner wall of the air-powder duct, with a first side of the electrostatic loading ring connected to a first side of a first charge measurement sensor 120, and a second side of the electrostatic loading ring connected to a second side of the first charge measurement sensor 120.

[0058] According to one embodiment of the present application, each charge measurement sensor 120 includes a first-type metal ring sensor. Each first-type metal ring sensor is nested on the inner wall of the air-powder duct. The first side of the first first-type metal ring sensor is connected to the first side of the electrostatic charging system 110, and the second side of the first first-type metal ring sensor is connected to the second side of the electrostatic charging system 110. A signal detection sensor 130 is disposed between every two first-type metal ring sensors.

[0059] In one embodiment, the first type of metal ring sensor is a wider metal ring sensor.

[0060] According to one embodiment of the present application, each signal detection sensor 130 includes a second type metal ring sensor. Each second type metal ring sensor is nested on the inner wall of the air-powder duct and is disposed between two charge measurement sensors 120.

[0061] In one embodiment, the second type of metal ring sensor is a narrow ring sensor.

[0062] According to one embodiment of the present application, the device further includes an electrostatic unloading system 150. Each charge measurement sensor 120 and each signal detection sensor 130 is disposed between the electrostatic loading system 110 and the electrostatic unloading system 150, with a first side of the electrostatic unloading system 150 connected to a first side of the last charge measurement sensor 120, and a second side of the electrostatic unloading system 150 connected to a second side of the last charge measurement sensor 120.

[0063] In some embodiments, the electrostatic unloading system 150 is used to unload the charge of the electrostatic ions on the surface of each coal powder particle so that each electrostatic ion reaches an unsaturated state.

[0064] According to one embodiment of the present application, the electrostatic unloading system 150 includes a third electrode plate and a fourth electrode plate. The third electrode plate is disposed on a first side of the inner wall of the air-powder duct, and the fourth electrode plate is disposed on a second side of the inner wall of the air-powder duct. The first side of the third electrode plate is connected to the first side of the last charge measurement sensor 120, and the second side of the fourth electrode plate is connected to the second side of the last charge measurement sensor 120.

[0065] like Figure 2 As shown, according to one embodiment of the present application, the device 100 further includes a carbon content detection sensor 160, which is used to detect the carbon content in each coal powder particle.

[0066] like Figure 2As shown, according to one embodiment of the present application, the device 100 further includes a water content detection sensor 170, which is used to detect the water content in each coal powder particle.

[0067] See Figure 3 , Figure 3 Schematic diagram of the overall structure of the heating system 200 provided in the embodiment of the present application. Figure 3 As shown, the system 200 includes: a raw coal bin 210, a coal feeder 220, a coal mill 230, an air-powder duct, a pulverized coal burner 240, a boiler 250, a heating duct and a primary air-powder concentration measuring device 100.

[0068] In some embodiments, the raw coal bin 210 is used to store coal, the coal feeder 220 is used to transport the coal in the raw coal bin 210 to the pulverizer 230, the pulverizer 230 is used to grind the coal to obtain coal powder, and the air-powder pipeline is used to transport the primary air-powder to the coal powder burner 240.

[0069] In some embodiments, the boiler 250 is used to heat the supply water to obtain hot water based on the pulverized coal burner 240. The heating pipe is used to transport the hot water to the user. The measuring device 100 is used to measure the primary air powder concentration in the air powder pipe when the power plant is under low load.

[0070] This application utilizes electrostatic charging enhancement technology. Based on the flow characteristics of air-coal mixtures, the electrostatic ions on the surface of the pulverized coal are in an unsaturated state after two-phase flow (air-powder mixing). Electrodes are installed before device 100. Based on the capacitance principle of electrostatic charging technology, a spatially contained sensor can be used to detect the flow rate, concentration, mass flow rate, particle fineness, calorific value, and moisture content of the pulverized coal.

[0071] After measuring the specific value, the particle surface electrostatic unloading technology is used to convert the pulverized coal into a normal two-phase flow state. When the unit is under low load, the actual characteristics such as the air-pulverized coal concentration are reflected, so that the power plant operators can observe the actual state and make leveling adjustments.

[0072] This application solution is primarily designed to accurately measure the carbon content, moisture content, particle concentration, and flow rate of coal at low power plant loads. Higher carbon content reduces electrostatic binding; higher moisture content reduces electrostatic charge; larger coal particle surface areas increase charge; and higher capacitance diaphragm insulation increases the signal.

[0073] Different factors can affect the amount of charge carried by coal powder particles, leading to inaccurate measurement results. To ensure accurate measurement, two electrode plates are installed in front of the measuring device 100. Electrostatic loading technology can effectively ensure that the charge carried by coal powder particles is full.

[0074] In the present application, the electrostatic loading system 110 charges the electrostatic ions on the surface of each coal powder particle when the power plant is under low load, so that each electrostatic ion is saturated. Each charge measurement sensor 120 measures the total charge of the electrostatic ions that have reached the saturated state. Each signal detection sensor 130 generates an electrical signal. The controller 140 calculates the coal powder mass flow rate based on the electrical signal, and then calculates the primary air-powder concentration based on the total charge of the electrostatic ions and the coal powder mass flow rate.

[0075] The application scheme can accurately measure the primary air dust concentration under low load conditions of the power plant and has strong ease of use and practicality.

[0076] This application solution can accurately reflect the real-time parameters of the pulverized coal pipeline at low load, helping operators to make better adjustments.

[0077] This application solution can solve the following problems:

[0078] (1) When operating at low load, the power plant boiler does not measure the primary air flow rate, flow velocity, and pulverized coal particle concentration, and the combustion heat and kinetic energy of each burner is unknown. This results in the burner state being unadjustable under various load conditions, leading to combustion problems such as overheating and coking that cannot be solved. Furthermore, the frequent load adjustments required to adapt the boiler to the load result in poor low-load stable combustion capabilities.

[0079] (2) In the current dilute phase transport of pulverized coal particles, tiny solid particles are unevenly distributed in the transport pipeline, resulting in inaccurate electrostatic potential. The concentration of pulverized coal particles in dilute phase transport is too low to measure the low potential of ordinary electrostatic potentiometers. The particle concentration that can be measured by this application scheme is less than 50kg / m3.

[0080] (3) Low particle concentration or high moisture content in the dilute phase transport of pulverized coal reduces the ability of the particle surface to carry electrostatic charges, resulting in low potentials that cannot be measured by ordinary electrostatic potentiometers. This application scheme can improve detection capabilities, with the lowest measurable particle temperature in the dilute phase transport of pulverized coal as low as 50°C and the highest measurable raw coal moisture content up to 45%.

[0081] This application solution uses electrostatic loading enhancement technology to solve the problem of inaccurate measurement of pulverized coal concentration and flow rate in the dilute phase. Under low load conditions of the power plant, the pulverized coal concentration can be accurately measured, allowing the power plant to make precise adjustments based on actual conditions.

[0082] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0083] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0084] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A primary air powder concentration measuring device, characterized in that: It is installed on the inner wall of the air-powder duct, and the primary air-powder is a mixture of primary air and multiple coal powder particles; the device includes: an electrostatic loading system, multiple charge measurement sensors and multiple signal detection sensors; The electrostatic loading system is connected to the first charge measurement sensor, and a signal detection sensor is provided between every two charge measurement sensors. The electrostatic loading system is used to load the electrostatic ions on the surface of each pulverized coal particle with charge when the power plant is under low load, so that each electrostatic ion reaches a saturated state. Each charge amount measuring sensor is used to measure the total charge amount of the electrostatic ions that have reached a saturated state; each signal detecting sensor is used to detect the charge when the electrostatic ions that have reached a saturated state flow through it and generate an electrical signal.

2. The primary air powder concentration measuring device according to claim 1, characterized in that: The electrostatic loading system includes: a first electrode plate and a second electrode plate; The first electrode plate is arranged on a first side of the inner wall of the air-powder duct, and the second electrode plate is arranged on a second side of the inner wall of the air-powder duct, and the first electrode plate and the second electrode plate constitute an electrostatic loading capacitor; A first side of the first electrode plate is connected to a first side of the first charge amount measurement sensor, and a second side of the second electrode plate is connected to a second side of the first charge amount measurement sensor.

3. The primary air powder concentration measuring device according to claim 1 or 2, characterized in that: The electrostatic loading system includes an electrostatic loading ring; The electrostatic loading ring is nested on the inner wall of the air powder duct, the first side of the electrostatic loading ring is connected to the first side of the first charge measurement sensor, and the second side of the electrostatic loading ring is connected to the second side of the first charge measurement sensor.

4. The primary air powder concentration measuring device according to claim 1, characterized in that: Each charge quantity measurement sensor includes a first type metal ring sensor; Each first-class metal ring sensor is nested on the inner wall of the air-powder duct, the first side of the first first-class metal ring sensor is connected to the first side of the electrostatic loading system, the second side of the first first-class metal ring sensor is connected to the second side of the electrostatic loading system, and a signal detection sensor is arranged between every two first-class metal ring sensors.

5. The primary air powder concentration measuring device according to claim 1, characterized in that: Each signal detection sensor includes a second type metal ring sensor; Each second type metal ring sensor is nested on the inner wall of the air-powder duct, and each second type metal ring sensor is arranged between two charge measurement sensors.

6. The primary air powder concentration measuring device according to claim 1 or 4, characterized in that: The device also includes a static unloading system; Each charge measurement sensor and each signal detection sensor is arranged between the electrostatic loading system and the electrostatic unloading system; the first side of the electrostatic unloading system is connected to the first side of the last charge measurement sensor, and the second side of the electrostatic unloading system is connected to the second side of the last charge measurement sensor; The electrostatic unloading system is used to unload the charge of the electrostatic ions on the surface of each coal powder particle, so that each electrostatic ion reaches an unsaturated state.

7. The primary air powder concentration measuring device according to claim 6, characterized in that: The electrostatic unloading system includes: a third electrode plate and a fourth electrode plate; The third electrode plate is arranged on the first side of the inner wall of the air-powder duct, the fourth electrode plate is arranged on the second side of the inner wall of the air-powder duct, the first side of the third electrode plate is connected to the first side of the last charge measurement sensor, and the second side of the fourth electrode plate is connected to the second side of the last charge measurement sensor.

8. The primary air powder concentration measuring device according to claim 1, characterized in that: The device further comprises a carbon content detection sensor, which is used to detect the carbon content in each pulverized coal particle.

9. The primary air powder concentration measuring device according to claim 1 or 8, characterized in that: The device further comprises a water content detection sensor, which is used to detect the water content in each coal powder particle.

10. A heating system, characterized in that: The system comprises: a raw coal bunker, a coal feeder, a coal mill, an air-powder duct, a pulverized coal burner, a boiler, a heating duct, and a primary air-powder concentration measuring device according to any one of claims 1 to 9; The raw coal bunker is used to store coal; the coal feeder is used to transport the coal in the raw coal bunker to the coal mill; the coal mill is used to grind the coal to obtain coal powder; the air-powder duct is used to transport the primary air and coal powder to the coal powder burner; The boiler is used to heat the supply water based on the pulverized coal burner to obtain hot water; the heating pipeline is used to transport the hot water to the user; the measuring device is used to measure the primary air powder concentration in the air powder pipeline when the power plant is under low load.

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