A method and system for intelligent explosion-proof control in underground mines

Abstract

The present invention relates to the technical field of electrical explosion-proofing in mining areas, and specifically to an intelligent explosion-proof control method and system for underground mining, including an electrical control device, a frequency converter, a motor, and a sensor system; the electrical control device is connected to a plurality of frequency converters, controls and dispatches the frequency converters, distributes and monitors the use of electricity, and the electricity is converted by a separate frequency converter to power each motor, and the motor provides power for a plurality of underground electrical equipment. The sensor system includes a temperature sensor for monitoring a plurality of electrical equipment. The present invention starts with the use characteristics of the equipment, conducts targeted analysis, and combines the correlation between the equipment and the use temperature to adjust the use time of the equipment and the power distribution, thereby improving the safety of underground work, making the production rhythm smooth, and improving production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical explosion-proofing in mining areas, and in particular to an intelligent underground explosion-proof control method and system for mining. Background Art

[0002] A mine is a high-risk environment with explosive substances such as flammable gas and dust. To ensure the safety of miners and the normal operation of mine equipment, the existing control system mainly monitors the environmental parameters in the mine in real time, such as gas concentration, temperature, humidity, etc. When the environmental parameters exceed the safe range, the system can automatically take countermeasures, such as shutting down electrical equipment and triggering alarms, to avoid fire and explosion accidents.

[0003] Among them, for underground explosion-proof work, an important indicator is the operating temperature of the equipment and environment. When high-power electrical equipment works for a long time, it will cause overheating and easily cause accidents such as combustion and explosion. At present, mine explosion-proof intelligent control systems have been widely used in many mines. Using technical means such as sensors, data acquisition systems, communication technology and intelligent control algorithms, the system can monitor various environmental parameters in the mine in real time, mainly temperature, and can transmit data to the remote monitoring center through the network, making the mine explosion-proof intelligent control system more efficient, accurate and reliable, and providing a more reliable safety environment for miners' safety and normal equipment production. However, there are still certain problems with the current mine explosion-proof control systems and methods, mainly including:

[0004] 1) Insufficient system reliability: Although the mine explosion-proof intelligent control system has certain monitoring and early warning functions, in actual applications, the stability and reliability of the system still have certain problems, especially in complex and harsh mine environments, it is prone to interference or failure.

[0005] 2) Diversified equipment, inconsistent control methods and standards: There are multiple high-power electrical equipment in the mine, and the working hours and power requirements of each equipment are different. Some equipment also has its own cooling system, but the heating characteristics of each equipment when in use are also different. At present, the alarm threshold is set, which can only achieve early warning or alarm when the problem occurs, and it is difficult to prevent it before it happens. And when the temperature warning threshold is reached, the equipment often needs to be shut down, which causes the work in the mine to stop, affecting production efficiency. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides an intelligent explosion-proof control system for underground mines. Starting from the use characteristics of the equipment, targeted analysis is carried out, and combined with the correlation between the equipment and the use temperature, the use time of the equipment and the power distribution are adjusted, thereby improving the safety of underground work, smoothing the production rhythm, and improving production efficiency.

[0007] The complete technical solution of the present invention includes:

[0008] A mine underground explosion-proof intelligent control system includes an electrical control device, a frequency converter, a motor, and a sensor system; the electrical control device is connected to multiple frequency converters, controls and dispatches the frequency converters, distributes and monitors the use of electricity, and the electricity is converted by a separate frequency converter to power each motor, and the motor provides power for multiple underground electrical equipment. The sensor system includes a temperature sensor for monitoring multiple electrical equipment.

[0009] Furthermore, the frequency converter is used to control the speed of the motor to achieve precise control of the lifting equipment.

[0010] Furthermore, the electrical control device adopts a programmable logic controller or a distributed control system.

[0011] Furthermore, the frequency converter is a four-quadrant three-level explosion-proof frequency converter.

[0012] Furthermore, the frequency converter includes a main control board, an I / O board, an input reactor, an input contactor, a charging resistor, a filter capacitor, a laminated busbar, a feedback unit, an inverter unit, and a keyboard display sheet metal part. The I / O board is connected to the main control board for communication via Ethernet. The main control board is connected to the feedback unit and the inverter unit via optical fiber communication, and the input three-phase power supply is connected and enters the input reactor. After passing through the input reactor, each phase of the three-phase power supply is connected through a switch, an input contactor, and a charging resistor. The wires after the input contactor and the charging resistor are merged and enter the feedback unit. The feedback unit is connected to the filter capacitor and the inverter unit, and the inverter unit is connected to the motor. The power input from the power grid enters the feedback unit, is rectified, and then outputs three-phase power to the inverter unit for motor operation. The part where the feedback unit is connected to the filter capacitor is provided with a laminated busbar. The inverter feedback unit and the filter power supply are connected by a laminated busbar, which has the function of reducing stray inductance and reducing peak voltage to protect IGBT.

[0013] Furthermore, underground electrical equipment includes conveying equipment, crushing equipment, ventilation equipment and water equipment.

[0014] Furthermore, the conveying equipment includes a belt conveyor and an elevator.

[0015] Furthermore, the crushing equipment includes a crusher and a grinding mill.

[0016] Furthermore, the ventilation equipment includes a fan.

[0017] Furthermore, the water-using equipment includes a water pump.

[0018] Furthermore, a method for underground explosion-proof intelligent control using the system comprises the following steps:

[0019] (1) Data collection

[0020] A temperature sensor is used to collect the real-time temperature of the equipment when it is in use, and combined with the equipment usage time, data is obtained, including the total time of a fixed time period, the number of times each device works within the time period, the start time of each work, the continuous working time of each work, and the cumulative working time of the equipment, and the equipment working temperature collected by the temperature sensor within the fixed time period.

[0021] (2) Data processing

[0022] The data obtained in step (1) is processed to obtain uniformity indicators of equipment use, including:

[0023] 1) Assume that the total working time is T, the number of times the equipment is used is n, and the start time of each work is t1, t2, ..., t n , get the interval time Δt of each work i =t i+1 -t i , i=1,2…n-1.

[0024] Processing to obtain the standard interval time: ;

[0025] [] indicates rounding.

[0026] Get the sample variance S of each standard time 2 , as an indicator of uniformity of equipment use.

[0027] (3) Correlation analysis

[0028] The Pearson correlation coefficient was used to analyze the correlation between the number of operations, the cumulative working time of the equipment, and the uniformity index of equipment use and the maximum temperature, and was divided into strong correlation and weak correlation.

[0029] (4) Based on the analysis results, for each device, for its parameters with strong correlation, multivariate linear regression is performed based on the collected data to obtain the relationship between each parameter and the maximum temperature of the device, and the weight coefficient is adjusted to regulate the use of the equipment.

[0030] Furthermore, in step (1), the equipment includes: a belt conveyor, an elevator, a crusher, a grinding mill, a fan and a water pump.

[0031] Furthermore, in step (3), within a given time period, the correlation between the number of working times and all equipment is weak. For fans and water pumps, the cumulative working time of the equipment and the uniformity index of equipment use are weakly correlated with their maximum temperature; for crushers and mills, the cumulative working time and the uniformity of equipment use are strongly correlated with their maximum temperature. The correlation between the cumulative working time of belt conveyors and elevators and the uniformity of equipment use is lower than that of crushers and mills.

[0032] Furthermore, in step (4), specifically for the crusher and the grinding mill, the uniformity of the equipment use is regulated, and the uniformity index S of the equipment use is set. 2 Upper limit, making the uniformity index S of crusher and mill working 2 below this limit.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] In order to solve the problem that a plurality of high-power electrical equipment underground have different working hours and power demands and significantly different heating phenomena during use, the present invention collects data and analyzes the influence of main working parameters on the operating temperature of equipment, analyzes their correlation, eliminates unimportant parameters and equipment that is not greatly affected, performs key control on key equipment, smoothes the operating frequency band of key equipment, avoids rapid increase of equipment temperature in a short period of time, ensures its safe and reliable operation, makes the operating temperature relatively gentle, does not affect the operation of underground equipment, and improves production efficiency. DETAILED DESCRIPTION

[0035] The technical solutions in the implementation modes of the present application will be described clearly and completely below. Obviously, the described implementation modes are only for illustration and are not intended to limit the present application.

[0036] The following is a schematic description of an underground explosion-proof intelligent control system for mining disclosed in the present invention.

[0037] Including electrical control devices, frequency converters, motors, and sensor systems;

[0038] The electrical control device can adopt PLC (Programmable Logic Controller) or DCS (Distributed Control System), which can accurately control and dispatch the inverter, monitor the power usage, and respond to various signals and data in the system in real time to ensure the stable and efficient operation of the whole system.

[0039] The electrical control device is connected to multiple frequency converters, and the transmitted electricity is converted by a separate frequency converter to power each motor, where the frequency converter is used to control the speed of the motor to achieve precise control of the lifting equipment.

[0040] The motors belong to a number of high-power underground electrical equipment, including transportation equipment such as belt conveyors and hoists, crushing equipment such as crushers and grinders, fans of ventilation equipment, and water pumps.

[0041] The sensing system includes temperature sensors that monitor multiple electrical devices.

[0042] The inverter is a four-quadrant three-level explosion-proof inverter, including a main control board, an I / O board, an input reactor, an input contactor, a charging resistor, a filter capacitor, a laminated busbar, a feedback unit, an inverter unit, and a keyboard display sheet metal part. The I / O board connects to the main control board for communication via Ethernet. The main control board is connected to the feedback unit and the inverter unit through optical fiber communication. The input three-phase power supply is connected and enters the input reactor. After passing through the input reactor, each phase of the three-phase power supply is connected through a switch, an input contactor, and a charging resistor. The wires after the input contactor and the charging resistor are merged and enter the feedback unit. The feedback unit is connected to the filter capacitor and the inverter unit, and the inverter unit is connected to the motor. The power input from the grid enters the feedback unit, and after rectification, it outputs three-phase power to the inverter unit for motor operation. The part where the feedback unit is connected to the filter capacitor is provided with a laminated busbar. The inverter feedback unit and the filter power supply are connected by a laminated busbar, which has the function of reducing stray inductance and reducing peak voltage to protect IGBT.

[0043] The electrical control device controls the frequency converter to adjust the operating parameters of the motor according to the preset program.

[0044] As mentioned above, due to the presence of multiple high-power electrical equipment underground, and the complex underground environment, there are combustible gases, dust and other explosive dangerous substances, it is easy to cause equipment overheating due to excessive power, thus causing danger. At present, monitoring is mainly carried out through temperature sensors or current and voltage monitoring to prevent equipment from overheating, but there are many types of equipment at present, and the rated power, standards or cooling methods of each equipment are not unified. Therefore, when working underground, due to the different characteristics of each equipment, the heating characteristics are also different. The use of sensors for monitoring can only be applied to emergency situations, and when the temperature warning threshold is reached, the equipment is often shut down for processing, causing the underground work to pause, which will make the work rhythm not smooth enough for a long time.

[0045] Therefore, in order to solve this problem, the present invention proposes a method for adjusting the power distribution of underground equipment, which collects and analyzes the usage data of underground equipment, obtains the usage characteristics of each device, and adjusts the usage of each device based on this. Specifically, it includes:

[0046] (1) Data collection

[0047] A temperature sensor is used to collect the real-time temperature of the equipment when it is in use, and combined with the equipment use time, data is obtained, including the total time of a fixed time period, which is 6 hours in this embodiment, the number of times each device works in this time period, the start time of each work, the continuous working time of each work, and the cumulative working time of the equipment, and the working temperature of the equipment collected by the temperature sensor in the fixed time period. The equipment includes: belt conveyor, elevator, crusher, mill, fan and water pump.

[0048] (2) Data processing

[0049] The data obtained in step (1) is processed to obtain uniformity indicators of equipment use, including:

[0050] 1) Assume that the total working time is T, in minutes, which is 360 in this implementation, the number of times the equipment is used is n, and the start time of each work is t1, t2...t n , get the interval time Δt of each work i =t i+1 -t i , i=1,2…n-1.

[0051] Processing to obtain the standard interval time: ;

[0052] [] indicates rounding.

[0053] Get the sample variance S of each standard time 2 , as an indicator of uniformity of equipment use.

[0054] (3) Correlation analysis

[0055] The Pearson correlation coefficient method was used to analyze the correlation between the number of working times, the cumulative working time of the equipment, and the uniformity index of equipment use and the maximum temperature, and divided them into strong correlation and weak correlation.

[0056] Through analysis, it is found that within a given time period, for fans and water pumps, the number of working times, the cumulative working time of the equipment, and the uniformity index of equipment use and their maximum temperature all show a weak correlation, and the correlation between the number of working times and the remaining equipment is not high. However, for crushers and mills, the cumulative working time and the uniformity of equipment use have a significant impact on the equipment temperature. The longer the time, the more uneven the frequency of use, and the higher the temperature will be in a short period of time, which poses a relatively obvious risk to underground explosion-proof work, so it needs to be focused on. The correlation between the cumulative working time and the uniformity of equipment use of belt conveyors and hoists is slightly lower than that of crushers and mills.

[0057] (4) Based on the analysis results, for each device, for its parameters with strong correlation, multivariate linear regression is performed based on the collected data to obtain the relationship between each parameter and the maximum temperature of the equipment, and the weight coefficient is adjusted to regulate the use of the equipment. Specifically, for crushers and mills, the uniformity of their equipment use is regulated, and the uniformity index S of the equipment use is set. 2 Upper limit, making the uniformity index S of crusher and mill working 2 Below this upper limit. The use of belt conveyors and elevators can be adjusted accordingly to the crusher and mill. There is no restriction on the operation of fans and water pumps.

[0058] Through this design, the use rhythm of each device can be effectively adjusted to ensure its safe and reliable operation and keep the use temperature relatively gentle, avoiding accidents such as gas explosions caused by overheating of equipment.

[0059] The above applications are only some implementation methods of the present application. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A method for underground explosion-proof intelligent control using an underground explosion-proof intelligent control system for mines, characterized in that: The underground explosion-proof intelligent control system for mines includes an electrical control device, a frequency converter, a motor, and a sensor system; the electrical control device is connected to multiple frequency converters, controls and dispatches the frequency converters, distributes and monitors the use of electricity, and the electricity is converted by a separate frequency converter to power each motor, and the motor provides power for multiple underground electrical equipment. The sensor system includes a temperature sensor that monitors multiple electrical equipment; the following steps are included: (1) Data collection Use temperature sensors to collect real-time temperature of the equipment when it is in use, and combine it with the equipment usage time to obtain data, including the total time of a fixed time period, the number of times each device works in the time period, the start time of each work, the continuous working time of each work, and the cumulative working time of the equipment, and the working temperature of the equipment collected by the temperature sensor in the fixed time period; (2) Data processing The data obtained in step (1) is processed to obtain uniformity indicators of equipment use, including: 1) Assume that the total time is T, the number of times the equipment works is n, and the start time of each work is t1, t2...t n , get the interval time Δt of each work i =t i+1 -t i , i=1,2,…,n-1; Processing to obtain the standard interval time: ; [ ] means rounding; Get the sample variance S of each standard interval time 2 , as an indicator of uniformity of equipment use; (3) Correlation analysis The Pearson correlation coefficient was used to analyze the correlation between the number of operations, the cumulative working time of the equipment, and the uniformity index of equipment use and the maximum temperature, and was divided into strong correlation and weak correlation; (4) Based on the analysis results, for each device, for its parameters with strong correlation, multivariate linear regression is performed based on the collected data to obtain the relationship between each parameter and the maximum temperature of the device, and the weight coefficient is adjusted to regulate the use of the equipment.

2. The method for underground explosion-proof intelligent control according to claim 1, characterized in that: The frequency converter is used to control the speed of the motor to achieve precise control of the lifting equipment.

3. The method for underground explosion-proof intelligent control according to claim 2, characterized in that: The electrical control device adopts a programmable logic controller or a distributed control system.

4. The method for underground explosion-proof intelligent control according to claim 3, characterized in that: The inverter is a four-quadrant three-level explosion-proof inverter.

5. The method for underground explosion-proof intelligent control according to claim 4, characterized in that: Underground electrical equipment includes conveying equipment, crushing equipment, ventilation equipment and water-using equipment.

6. The method for underground explosion-proof intelligent control according to claim 5, characterized in that: Conveying equipment includes belt conveyors and elevators.

7. The method for underground explosion-proof intelligent control according to claim 6, characterized in that: Crushing equipment includes crushers and mills.

8. The method for underground explosion-proof intelligent control according to claim 7, characterized in that: The ventilation equipment includes fans.

9. The method for underground explosion-proof intelligent control according to claim 8, characterized in that: Water-using equipment includes water pumps.

10. The underground explosion-proof intelligent control method according to claim 9, characterized in that: In step (4), for the crusher and the grinding mill, the uniformity index of the equipment is adjusted and the uniformity index of the equipment is set to S 2 Upper limit, making the uniformity index S of crusher and mill working 2 below this limit.

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