A control method and system for preventing coal feeder return powder and a coal feeder

Abstract

The application provides a control method and system for preventing coal powder return of a coal feeder and the coal feeder. The method comprises the following steps: performing a power-on operation on a body of the coal feeder, causing the coal powder to be adsorbed on a first position of the body where the power-on operation is performed; forming a conductive loop between the coal powder and the first position according to the first position; determining a current of the loop according to the conductive loop; and performing a power-off operation on the body when the current of the loop reaches a current threshold, thereby preventing the coal powder return of the coal feeder. The current between the coal powder and the first position of the body of the coal feeder is monitored, the coal feeder is prevented from storing excessive coal powder, and a spontaneous combustion accident of the coal powder in the coal feeder is prevented. The method has the characteristics of high sensitivity and strong stability, and maximally improves the safety of a power plant device.

Description

Technical Field

[0001] This application relates to the field of coal conveying equipment application technology in thermal power plants, and in particular to a control method, system and coal feeder for preventing coal feeder backflow. Background Technology

[0002] As a crucial component of the power plant's fuel delivery system, the coal feeder is positioned between the raw coal hopper and the coal mill. By adjusting its speed according to grid load requirements, it accurately regulates the coal feed rate to the coal mill, adjusts boiler combustion, and controls the main steam temperature and pressure, thereby controlling the overall unit's power generation to meet grid system demands. In positive-pressure pulverizing systems, if the belt feeder's hopper is exposed to the atmosphere after coal supply is interrupted, pulverized coal from the coal mill will be backflowed into the feeder. If this backflow is not monitored promptly and the feeder is not isolated, a large accumulation of pulverized coal will occur, potentially leading to spontaneous combustion and a fire.

[0003] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0004] This application provides a control method, system, and coal feeder for preventing coal feeder backflow.

[0005] The first aspect of this application provides a control method for preventing coal feeder backflow, including:

[0006] The coal feeder body is energized, and the coal powder is adsorbed at the first position of the energized body according to the energizing operation.

[0007] Based on the first position, a conductive circuit is formed between the pulverized coal and the first position;

[0008] Determine the current in the circuit based on the conductive path;

[0009] When the current in the circuit reaches the current threshold, the power to the main body is cut off to prevent the coal feeder from returning to its original state.

[0010] A second aspect of this application provides a control system for preventing coal feeder backflow, comprising: a sensing module, a control module, a vibration module, a locking module, and a coal feeder body, wherein:

[0011] The sensing module is located at the first position of the coal feeder body and is used to adsorb coal powder and form a conductive circuit with the coal powder.

[0012] The control module and the sensing module are connected to monitor the current in the conductive circuit and control the power-off action of the coal feeder body.

[0013] The vibration module and the sensing module are closely fitted together and used to remove powder from the first position;

[0014] The control module is installed at the coal outlet of the coal feeder body to prevent coal powder from returning after the coal feeder body is powered off.

[0015] The third aspect of this application provides a coal feeder, including: a control system for preventing coal feeder backflow as proposed in the second aspect of this application.

[0016] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0017] By monitoring the current between the pulverized coal and the first position of the coal feeder body, excessive pulverized coal can be prevented from accumulating inside the coal feeder, thus preventing spontaneous combustion accidents caused by pulverized coal inside the coal feeder. It has the characteristics of high sensitivity and strong stability, which maximizes the safety of thermal power plant equipment.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 A schematic flowchart illustrating a control method for preventing coal feeder backflow provided in an embodiment of this application;

[0021] Figure 2 A schematic flowchart illustrating another control method for preventing coal feeder backflow provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of a control system for preventing coal feeder backflow, provided in an embodiment of this application. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a” and “the” as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0025] It should be understood that although the terms first, second, third, etc., may be used to describe various information in the embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words "if" and "suppose" as used herein can be interpreted as "when," "when," or "in response to a determination."

[0026] Embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0027] It should be noted that the control method for preventing coal feeder backflow provided in any embodiment of this application can be executed alone, or can be executed together with possible implementation methods in other embodiments, or can be executed together with any technical solution in related technologies.

[0028] The following describes, with reference to the accompanying drawings, a control method, system, and coal feeder for preventing coal feeder backflow according to embodiments of this application.

[0029] Figure 1 This is a flowchart illustrating a control method for preventing coal feeder backflow, provided as an embodiment of this application. Figure 1 As shown, the method includes, but is not limited to, the following steps:

[0030] S101, the main body of the coal feeder is energized, and according to the energization operation, the coal powder is adsorbed in the main body at the first position of the energization operation.

[0031] It should be noted that coal is pulverized into coal powder through a pulverizing process, and the coal powder is fed to the boiler by a coal feeder. Coal powder refers to coal with a particle size of less than 0.5 mm. Each unit mass of coal powder has a large surface area. During the conveying process, due to the friction between the coal powder and the air, the coal powder becomes charged, which energizes the coal feeder. According to the principle of electromagnetic induction, a magnetic field is generated at the first position of the energized operation of the coal feeder, which attracts the charged coal powder.

[0032] S102, based on the first position, a conductive circuit is formed between the pulverized coal and the first position.

[0033] It should be noted that, under the influence of electricity, pulverized coal is adsorbed at the first position. When the pulverized coal at the first position reaches a certain mass, a conductive circuit is formed between the first position and the adsorbed pulverized coal, generating a current. The more pulverized coal adsorbed at the first position, the greater the current generated.

[0034] S103, Determine the current in the circuit based on the conductive path.

[0035] It should be noted that as the mass of coal powder adsorbed at the first position increases, the current increases. By monitoring the current at the first position, the coal powder concentration inside the feeder can be alarmed. When the current exceeds the threshold, it indicates that the coal powder concentration inside the feeder has reached the critical point of coal powder return, and intervention is required on the feeder.

[0036] S104 cuts off power to the main body when the current in the circuit reaches the current threshold to prevent coal feeder from returning to its original state.

[0037] It should be noted that when the coal powder concentration inside the feeder reaches the critical point of coal powder return, the power should be cut off in time to stop the feeder's operation and perform a de-powdering operation. After the de-powdering is completed, the coal powder adsorbed at the first position is removed, and the feeder is powered back on. At the same time, the current at the first position continues to be monitored to prevent coal powder return. If a large amount of coal powder accumulates inside the feeder, it is prone to spontaneous combustion. Therefore, the control method for preventing coal powder return provided in this application can effectively improve the safety of the equipment.

[0038] Figure 2 This is a flowchart illustrating another control method for preventing coal feeder backflow provided in an embodiment of this application. Figure 2 As shown, the method includes, but is not limited to, the following steps:

[0039] S201, the main body of the coal feeder is energized, and according to the energization operation, the coal powder is adsorbed at the first position of the main body where the energization operation is performed.

[0040] Optionally, as an example, a magnetic field is generated at the first position according to the power-on operation; the pulverized coal is adsorbed at the first position according to the action of the magnetic field.

[0041] It should be noted that a catalyst can also be added to adsorb coal powder onto specific locations on the substrate, and then the coal powder concentration per unit area at that specific location can be monitored (or the gravity of the coal powder per unit area can be detected by a sensor, and the mass of the coal powder can be characterized by gravity). The specific operations will not be described in detail here.

[0042] S202, based on the first position, a conductive circuit is formed between the pulverized coal and the first position.

[0043] Optionally, pulverized coal is adsorbed at a first location, and when the mass of the pulverized coal exceeds a conductivity threshold, a conductive circuit is formed between the pulverized coal and the first location. It should be noted that when pulverized coal is adsorbed at the first location and the mass of pulverized coal at the first location reaches a certain level, a conductive circuit is formed between the first location and the pulverized coal, generating current through the conductive circuit.

[0044] S203, determine the current in the circuit based on the conductive circuit.

[0045] Optionally, as an example, the conducting current is determined based on the conductive circuit, and the characterization relationship between the current value and the particulate matter concentration is determined; the current threshold is determined based on the conducting current. It should be noted that the particulate matter concentration refers to the concentration of coal powder particles in the bulk. The conducting current is determined by the mass of coal powder adsorbed at the first position. The larger the mass of coal powder, the larger the conducting current, and the larger the concentration of particulate matter in the bulk. In other words, there is a positive correlation between the concentration of particulate matter and the conducting current.

[0046] S204, based on the current threshold, determine the concentration threshold of pulverized coal in the bulk.

[0047] It should be noted that as more and more coal powder is adsorbed at the first position, the current conduction continues to increase. When the coal powder reaches the critical point of return, the coal powder in the body reaches the concentration threshold, and the current at this time also reaches the threshold.

[0048] S205, based on the concentration threshold, performs power-off and powder removal operations on the substrate.

[0049] Optionally, as an example, when the loop current reaches a threshold, an alarm is issued by the device monitoring the loop current; based on the alarm, the power to the coal feeder body is cut off, and the coal feeder outlet is shut down. It should be noted that the device monitoring the loop current is usually an external device to the coal feeder body. This device is a component of a DCS system (Distributed Control System, a new type of computer control system developed and evolved from centralized control systems. It is a multi-level computer system composed of process control and process monitoring levels linked by a communication network, integrating computer, communication, display, and control technologies (4C technologies). Its basic principles are distributed control, centralized operation, hierarchical management, flexible configuration, and convenient configuration). The alarm issued by this device is used to shut down the coal feeder.

[0050] S206, according to the de-pulverization operation, to prevent coal feeder from returning coal dust.

[0051] Optionally, as an example, de-powdering is performed at the first position based on the power being cut off from the main body; after de-powdering is completed at the first position, the main body of the coal feeder is powered on again. It should be noted that de-powdering at the first position can be performed by vibration or by ultrasound. The method of de-powdering should be selected according to the application scenario, which will not be elaborated here.

[0052] By monitoring the current between the pulverized coal and the first position of the coal feeder body, excessive pulverized coal can be prevented from accumulating inside the coal feeder, thus preventing spontaneous combustion accidents caused by pulverized coal inside the coal feeder. It has the characteristics of high sensitivity and strong stability, which maximizes the safety of thermal power plant equipment.

[0053] Figure 3 This is a schematic diagram of a control system for preventing coal feeder backflow, according to an embodiment of this application. Figure 3 As shown, the control system 300 for preventing coal feeder backflow includes: a sensing module 301, a control module 302, a vibration module, a locking module 303, and a coal feeder body 304, wherein:

[0054] The sensing module 301 is located at the first position of the coal feeder body 304, and is used to adsorb coal powder and form a conductive circuit with the coal powder. It should be noted that the sensing module 301 includes sensing electrodes, sensors, etc., and should be set according to the application scenario, without limitation here.

[0055] The control module 302 is connected to the sensing module 301 to monitor the current in the conductive circuit and control the power-off action of the coal feeder body. It should be noted that when the coal powder concentration in the coal feeder body 304 reaches the critical point of return, the control module 302 cuts off the power to the coal feeder body 304 to stop the operation of the coal feeder.

[0056] The vibration module and the sensing module 301 are tightly fitted together for removing powder from the first location. It should be noted that the vibration module is not... Figure 3 The demonstration showed that after the power was cut off to the coal feeder body 304, the vibration operation of the vibration module caused the sensing module 301 in the first position to shed powder.

[0057] The control module 303 is installed at the coal outlet of the coal feeder body 304 to prevent coal powder from returning after the coal feeder body is powered off.

[0058] Optionally, such as Figure 3As shown, the control system 300 for preventing coal feeder backflow also includes a relay module 305. The relay module 305 is connected between the control module 302 and the coal feeder body 304, and is used to adjust the power-off action of the coal feeder body. It should be noted that the relay module 305 may also be omitted, and the power-off action of the coal feeder body may be adjusted solely by the control module 302. The setting should be based on the application scenario, and no restrictions are imposed here.

[0059] This application also provides a coal feeder, which includes a control system for preventing coal dust backflow according to this application. By monitoring the current between the coal dust and the first position of the coal feeder body, it prevents excessive coal dust from accumulating inside the coal feeder and prevents spontaneous combustion accidents of coal dust inside the coal feeder. It has the characteristics of high sensitivity and strong stability, and maximizes the safety of thermal power plant equipment.

[0060] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0061] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A control method for preventing coal feeder backflow, characterized in that, include: The coal feeder body is energized, and an electric field is generated at the first position of the energized operation. Under the action of the electric field, the coal powder is adsorbed at the first position. During the conveying process, the coal powder becomes charged due to the friction between the coal powder and the air. Based on the first position, a conductive circuit is formed between the coal powder and the first position; wherein, the coal powder is adsorbed on the first position, and when the mass of the coal powder exceeds a threshold, a conductive circuit is formed between the coal powder and the first position; The conduction current is determined based on the conductive circuit, and the characterization relationship between the current value and the particulate matter concentration is determined. The threshold of the current is determined based on the conduction current. When the loop current threshold is reached, an alarm is issued by the device monitoring the loop current. Based on the alarm, the power to the main body of the coal feeder is cut off and the coal feeder outlet is shut down to prevent coal feeder backflow.

2. The method according to claim 1, characterized in that, The method for preventing coal feeder backflow includes: Based on the power outage of the main body, the powder is removed from the first position; After the powder removal is completed at the first position, power is continued to be applied to the main body of the coal feeder.

3. The method according to claim 2, characterized in that, The process of removing powder from the first position includes: The powder is removed from the first position by vibration.

4. A control system for preventing coal feeder backflow, comprising executing the method as described in any one of claims 1-3, characterized in that, include: The system comprises a sensing module, a control module, a vibration module, a locking module, and the coal feeder body, including: The sensing module is located at the first position of the coal feeder body and is used to adsorb coal powder and form a conductive circuit with the coal powder. The control module and the sensing module are connected to monitor the current in the conductive circuit and control the power-off action of the coal feeder body. The vibration module and the sensing module are closely fitted together and used to remove powder from the first position; The control module is installed at the coal outlet of the coal feeder body to prevent coal powder from returning after the coal feeder body is powered off.

5. The control system for preventing coal feeder backflow according to claim 4, characterized in that, Also includes: A relay module is connected between the control module and the coal feeder body, and is used to adjust the power-off action of the coal feeder body.

6. A coal feeder, characterized in that, The coal feeder includes a control system for preventing coal feeder backflow as described in claim 4 or 5.

Images