Method and system for judging disconnection of air duct of local fan based on working condition analysis

Abstract

The invention relates to a method for judging disconnection of an air duct of a local fan based on working condition analysis, and belongs to the technical field of mine ventilation. The method comprises the following steps: firstly, performing performance measurement on the ventilator according to a standard, fitting a local ventilator integrity performance curve after multiple groups of data are measured, and calculating a current fan operation condition according to real-time monitored air volume and static pressure; secondly, recording historical operation working conditions and working condition change fluctuation intervals, judging whether an air duct disjunction fault occurs or not according to monitored fan real-time operation working condition points and monitored air volume, and finally positioning the air duct disjunction position according to linkage of the air duct operation working conditions, air duct static pressure and air volume monitoring values. Therefore, the disconnection fault diagnosis of the mine local fan air duct is realized, the air supply quantity of an air using place is ensured, the working environment of a working face is adjusted, gas accumulation is prevented, and an automatic monitoring tool is provided for mine emergency management and control.

Description

Technical Field

[0001] This invention belongs to the field of mine ventilation technology, and relates to a method and system for judging the disconnection of local ventilation fan ducts based on working condition analysis. Background Technology

[0002] The primary function of local ventilation fans in mines is to provide directional and stable fresh airflow to ventilation dead zones such as working faces and chambers. This effectively dilutes and removes harmful substances like methane and dust, while supplying sufficient oxygen to create a safe working environment. Their operation is directly linked to safety systems such as wind-powered interlocks, making them core ventilation equipment for preventing methane accumulation beyond limits and ensuring safe mine production. Currently, intelligent variable frequency local ventilation fans are gradually being adopted by coal mining enterprises. Localized optimized air supply and fault self-diagnosis systems are beginning to be integrated into mine management systems, significantly improving the automation level of mine ventilation systems.

[0003] Currently, the most common method for checking ventilation duct disconnection in coal mines is on-site inspection by personnel. The core objective is to promptly detect ventilation duct abnormalities, ensure smooth ventilation at the tunneling face, and prevent safety accidents such as gas accumulation. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method and system for judging the disconnection of a local ventilation fan duct based on working condition analysis.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for determining the disconnection of a local ventilation fan duct based on operating condition analysis includes the following steps: S1: After changing the fan resistance by adjusting the gate, measure the operating points of each local ventilation fan in multiple groups; S2: Use the least squares method to fit the measurement points and draw the complete performance characteristic curve of the wind turbine; S3: Calculate the air volume at the fan outlet based on the roadway pressure difference and the fan performance characteristic curve, and install pressure sensors and air duct speed sensors; S4: Set the normal fluctuation range of the target wind turbine operating point in the operating environment; S5: Based on real-time operating point monitoring, if the operating point is abnormal, the duct disconnection fault diagnosis program will be started, the fan outlet air volume will be calculated, and the duct outlet air volume will be linked. If the fan outlet air volume and the duct outlet air volume exceed the normal air leakage rate of the duct, the duct disconnection fault has occurred; if they do not exceed the normal air leakage rate of the duct, the duct is deformed or the duct resistance changes due to an accident. S6: If a duct disconnection fault occurs, based on the static pressure at the fan outlet, use the static pressure monitoring sensor in the duct relay to locate the approximate location of the duct disconnection, issue an alarm and indicate that the section of the duct is abnormal.

[0006] Furthermore, in step S1, after changing the fan resistance using the regulating gate, a single-tube inclined barometer, a vertical U-shaped water column gauge, and a compensated micro-manometer are arranged according to the standard, and the performance of the local ventilation fan is measured according to the specific conditions and measurement accuracy requirements.

[0007] Furthermore, in step S2, the least squares method is used to perform nonlinear curve fitting to obtain the performance characteristic curve of the local ventilation fan at a fixed frequency. Q i = f ( H i If different frequencies are required, repeat the measurement after frequency conversion.

[0008] Furthermore, in step S3, the specific method for deploying the wind speed sensor in the wind duct is as follows: wind speed sensors are set at key nodes to ensure that the sensor deployment position can accurately reflect changes in airflow status; the key nodes include bends, branch points, and the fan outlet.

[0009] Furthermore, the troubleshooting steps for the duct disconnection fault diagnosis procedure in step S5 include: The sum of the air resistance of the multiple sections of the fan duct after the fan is regarded as the equivalent air resistance. R i Changes in the condition of the ventilation duct caused R i Changes have occurred; according to H=R i Q 2 The relationship is used to plot the duct resistance curve; the fan operating point is the intersection of the fan performance curve and the duct resistance curve, and is determined by monitoring the fan outlet static pressure. H j Calculate the real-time air volume at the fan outlet. Q j ， It provides real-time feedback on the operating conditions of the fan, indirectly reflecting the current operating status of the fan; it determines whether a fan duct disconnection fault has occurred, that is, it determines whether the fan static pressure is affected by the fan operating point deviation. H i Sudden increase, fan outlet air volume Q j A sudden increase, and the air volume at the duct outlet Q c A sudden decrease.

[0010] Furthermore, step S6, which involves using the static pressure monitoring sensor in the duct relay to locate the approximate location of the duct disconnection, specifically includes the following steps: According to the real-time monitoring value of static pressure of the fan H j and the performance characteristic curve of the fan Q i =f ( H i Calculate the outlet air volume after the fan operating point offset. Q c and according to H=R i Q 2 The equivalent total drag after offset is calculated using the formula. R h ; The formula for calculating the air resistance of a section of the ventilation duct is:

[0011] in α Friction resistance coefficient, unit N·s² / m 4 or Kg / m³ It depends on the material, roughness, and diameter of the duct. L This is the original length of the ventilation duct, in units of... m , U The perimeter of the ventilation duct cross-section, in units of m , S The cross-sectional area of ​​the ventilation duct is expressed in units of... m²； The above formula is transformed into the estimated length after the duct disconnection:

[0012] Now compare the original duct length L and L h Locate the disconnection point of the air duct: distance from the original air duct outlet ( LL h ) meters.

[0013] On the other hand, the present invention provides a local ventilation fan duct disconnection judgment system based on operating condition analysis, including a storage module, a monitoring module, and a calculation and judgment module, wherein: The storage module is used to fit and store the performance characteristic curve of the wind turbine at the measured frequency. The monitoring module is used to monitor the static pressure at the fan outlet and the air volume at the duct outlet in real time, and transmit the data to the calculation and judgment module. The static pressure at the fan outlet is obtained by the pressure sensor installed, and the air volume at the duct outlet is obtained by the air volume sensor installed at the duct outlet. The calculation and judgment module is used to determine whether the change in the monitored value exceeds the historical normal fluctuation range, and to calculate and locate the location of the duct disconnection fault.

[0014] The beneficial effects of this invention are as follows: Based on the constructed characteristic curve of the local ventilation fan and integrating real-time monitoring of the fan outlet static pressure, this invention adds a duct outlet airflow sensor to measure the fan operating conditions in real time and calculate the fan outlet airflow. It innovatively uses real-time monitoring to determine whether a duct disconnection fault has occurred, transforming manual inspection into online automated judgment, providing a rapid and effective means for the management of local ventilation fans in mines. This invention also innovatively uses a resistance inversion method to calculate the duct resistance change based on the actual airflow and actual pressure difference, providing a rough location of the duct disconnection fault and offering an effective technical means for mine ventilation professionals to quickly locate and repair it. Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0015] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 The flowchart shows the method for judging the disconnection of a local ventilation fan duct based on working condition analysis proposed in this invention. Figure 2 The present invention provides the fan characteristic curve and the duct resistance curve. Figure 3 This is a schematic diagram illustrating the calculation of the fan operating point based on the fan characteristic curve and the fan duct resistance curve proposed in this invention. Figure 4 This is a schematic diagram of the arrangement of measuring points for the proposed ventilation fan parameter measurement. Figure 5 This is a schematic diagram of the fault location calculation for air duct disconnection proposed in this invention; Figure 6 This is a schematic diagram of the duct disconnection fault identification system module proposed in this invention. Detailed Implementation

[0016] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0017] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0018] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0019] Example 1: like Figure 1 As shown, this invention provides a method for determining the disconnection of a local ventilation fan duct based on operating condition analysis, comprising the following steps: After changing the fan resistance by adjusting the gate valve, equipment such as a single-tube inclined barometer, a vertical U-shaped water column gauge, and a compensated micromanometer are used, following national standards. GB-1236-85 The "Test Method for Ventilation Fan Performance" is followed, and the performance of local ventilation fans is tested according to specific conditions and measurement accuracy requirements. The test is conducted on each local ventilation fan. 8~12 The working conditions of the group; the measured data are shown in Table 1.

[0020] Table 1

[0021] The performance characteristic curve of the local ventilation fan at a fixed frequency was obtained by using the least squares method for nonlinear curve fitting. Q i = f ( H i If different frequencies are required, repeat the measurement after frequency conversion; consider the sum of the air resistance of multiple sections of the fan duct after the fan as the equivalent air resistance. R i Changes in the condition of the ventilation duct caused R i Changes have occurred; according to H=R i Q 2 The relationship can be used to plot the duct resistance curve; the fitted curve is shown in the figure. Figure 2 As shown, the fitted equation for the wind turbine characteristic curve is: .

[0022] like Figure 3As shown, based on the actual simulated operating conditions of the ventilation duct, the calculation method is as follows: the fan operating point is the intersection of the fan performance curve and the ventilation duct resistance curve, and is determined by monitoring the static pressure at the fan outlet. H j Calculate the real-time air volume at the fan outlet. Q j ， The system provides real-time feedback on operating conditions, indirectly reflecting the current operating status of the fan. During the normal operation of the ductwork: the intersection of the fan curve and the ductwork resistance curve during the normal operation period is shown in the figure, corresponding to the operating point. P 正， Fan operating conditions fan outlet static pressure H i Approximately 7200Pa Calculate the air volume at the fan outlet. Q j Approximately 650m³ / min ; like Figure 4 As shown, the air volume at the fan outlet is calculated based on the roadway pressure difference and the fan performance characteristic curve. A pressure sensor is installed at the fan outlet, and a wind speed sensor is installed at the air duct outlet. The steps for determining the air duct disconnection fault are as follows: (1) Set the normal fluctuation range of the target wind turbine operating point in the operating environment; (2) Ventilation duct disconnection failure is a phenomenon in the ventilation system of a mine tunneling face where the flexible ventilation duct used to transport fresh air becomes detached or disconnected at the connection point. This will lead to R i Reduce, operating point due R i The shift in operating point causes changes in the fan's static pressure and airflow; determining whether a fan duct disconnection fault has occurred is equivalent to determining whether the fan's static pressure is affected by the shift in the fan's operating point. H i Sudden increase, fan outlet air volume Q j A sudden increase, and the air volume at the duct outlet Q c Sudden decrease, setting the range of change δ 0 >30% The indicator shows a sudden change. A disconnection fault occurred in the ventilation duct: the intersection of the fan curve and the ventilation duct resistance curve during the abnormal period is as follows... Figure 3 As shown, the corresponding operating point is P 异常， Fan operating conditions fan outlet static pressure H i Approximately 5400Pa Calculate the air volume at the fan outlet. Q j Approximately 770m³ / min Monitoring the air volume at the ventilation duct outlet Q cThe sudden decrease exceeded 30% .

[0023] (3) If the operating point is abnormal, start the duct disconnection fault diagnosis program, calculate the fan outlet air volume, and link the duct outlet air volume. If the fan outlet air volume and the duct outlet air volume exceed the normal air leakage rate of the duct, the duct disconnection fault has occurred; if they do not exceed the normal air leakage rate of the duct, the duct is deformed or the duct resistance changes due to accident.

[0024] The approximate location of the duct disconnection is determined by using real-time static pressure monitoring sensor values, such as... Figure 5 As shown, the specific steps are as follows: (1) Based on the real-time monitoring value of static pressure of the fan H j and the performance characteristic curve of the fan Q i = f ( H i The outlet air volume after the fan operating point shift can be calculated. Q c and according to H=R i Q 2 The equivalent total drag after offset is calculated using the formula. R h .

[0025] (2) Calculate the diameter of a segment 800mm The formula for the air resistance of a gel-type air duct is: ;where α The coefficient of friction resistance is taken as: 0.0032 N·s² / m 4 duct length L for 1000m The connector is a plug-in or reverse-side connector. Based on changes in operating conditions, the technical specifications are determined according to the air resistance coefficient of the outlet duct. R h The change is 32.36. Based on the change in resistance, the estimated length of the duct after disengagement can be calculated using the above formula: Now compare the original duct length L and L h Locate the disconnection point of the air duct: approximately [distance from the original air duct outlet]. LL h =1000-434=566m Place; Example 2: This embodiment provides a system for identifying disconnection of a local ventilation fan duct, such as... Figure 6 As shown, it includes a storage module, a monitoring module, and a calculation and judgment module, wherein: The storage module is used to fit and store the performance characteristic curve of the wind turbine at the measured frequency. The monitoring module is used to monitor the static pressure at the fan outlet and the air volume at the duct outlet in real time, and transmit the data to the calculation and judgment module. The static pressure at the fan outlet is obtained by the pressure sensor installed, and the air volume at the duct outlet is obtained by the air volume sensor installed at the duct outlet. The calculation and judgment module is used to determine whether the change in the monitored value exceeds the historical normal fluctuation range, and to calculate and locate the location of the duct disconnection fault.

[0026] Example 3: An electronic device, comprising a memory and a processor; The memory is used to store computer programs; The processor is configured to implement the method described in Embodiment 1 when executing the computer program.

[0027] Example 4: A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0028] Example 5: A computer program product includes a computer program that, when executed by a processor, implements the method described in Example 1.

[0029] In the above embodiments, the reference to "this embodiment" in the specification indicates that a specific feature, structure, or characteristic described in connection with the embodiment is included in at least some embodiments, but not necessarily all embodiments. Multiple appearances of "this embodiment" do not necessarily refer to the same embodiment.

[0030] In the above embodiments, although the invention has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory structures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed. The embodiments of the invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims.

[0031] As will be understood by those skilled in the art, the computer-readable storage medium described in this embodiment allows for the implementation of all or part of the steps in the above method embodiments by computer program-related hardware. The aforementioned computer program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0032] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver, and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication between them. The memory is used to store computer programs, the communication interface is used to perform communication, and the processor and the transceiver are used to run the computer programs, so that the electronic terminal performs the steps of the above method.

[0033] In this embodiment, the memory may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device.

[0034] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0035] This invention can be used in a wide range of general-purpose or special-purpose computing system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0036] This invention can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This invention can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0037] 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 it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for determining the disconnection of a local ventilation fan duct based on operating condition analysis, characterized in that: Includes the following steps: S1: After changing the fan resistance by adjusting the gate, measure the operating points of each local ventilation fan in multiple groups; S2: Use the least squares method to fit the measurement points and draw the complete wind turbine performance characteristic curve; S3: Calculate the air volume at the fan outlet based on the roadway pressure difference and the fan performance characteristic curve, and install pressure sensors and air duct speed sensors; S4: Set the normal fluctuation range of the target wind turbine operating point in the operating environment; S5: Based on real-time operating point monitoring, if the operating point is abnormal, the duct disconnection fault diagnosis program will be started, the fan outlet air volume will be calculated, and the duct outlet air volume will be linked. If the fan outlet air volume and the duct outlet air volume exceed the normal air leakage rate of the duct, the duct disconnection fault has occurred; if they do not exceed the normal air leakage rate of the duct, the duct is deformed or the duct resistance changes due to an accident. S6: If a duct disconnection fault occurs, based on the static pressure at the fan outlet, use the static pressure monitoring sensor in the duct relay to locate the approximate location of the duct disconnection, issue an alarm and indicate that the section of the duct is abnormal.

2. The method for determining the disconnection of a local ventilation fan duct based on operating condition analysis according to claim 1, characterized in that: In step S1, after changing the fan resistance by adjusting the gate, a single-tube inclined barometer, a vertical U-shaped water column gauge, and a compensated micro-manometer are arranged according to the standard, and the performance of the local ventilation fan is measured according to the specific conditions and measurement accuracy requirements.

3. The method for determining the disconnection of a local ventilation fan duct based on operating condition analysis according to claim 1, characterized in that: In step S2, the least squares method is used to perform nonlinear curve fitting to obtain the performance characteristic curve of the local ventilation fan at a fixed frequency. Q i = f ( H i If different frequencies are required, repeat the measurement after frequency conversion.

4. The method for determining the disconnection of a local ventilation fan duct based on operating condition analysis according to claim 1, characterized in that: In step S3, the specific method for deploying the wind speed sensor in the duct is as follows: set the wind speed sensor in the duct at key nodes to ensure that the sensor deployment position can accurately reflect the changes in airflow status; the key nodes include bends, branch points and fan outlets.

5. The method for determining the disconnection of a local ventilation fan duct based on operating condition analysis according to claim 1, characterized in that: The troubleshooting steps for the air duct disconnection fault diagnosis procedure in step S5 include: The sum of the air resistance of the multiple sections of the fan duct after the fan is regarded as the equivalent air resistance. R i Changes in the condition of the ventilation duct caused R i Changes have occurred; according to H= R i Q 2 The relationship is used to plot the duct resistance curve; the fan operating point is the intersection of the fan performance curve and the duct resistance curve, and is determined by monitoring the fan outlet static pressure. H j Calculate the real-time air volume at the fan outlet. Q j ， It provides real-time feedback on the operating conditions of the fan, indirectly reflecting the current operating status of the fan; it determines whether a fan duct disconnection fault has occurred, that is, it determines whether the fan static pressure is affected by the fan operating point deviation. H i Sudden increase, fan outlet air volume Q j A sudden increase, and the air volume at the duct outlet Q c A sudden decrease.

6. The method for determining the disconnection of a local ventilation fan duct based on operating condition analysis according to claim 1, characterized in that: Step S6, which involves using the static pressure monitoring sensor in the duct relay to locate the approximate location of the duct disconnection, specifically includes the following steps: According to the real-time monitoring value of static pressure of the fan H j and the performance characteristic curve of the fan Q i = f ( H i Calculate the outlet air volume after the fan operating point offset. Q c and according to H=R i Q 2 The equivalent total drag after offset is calculated using the formula. R h ; The formula for calculating the air resistance of a section of the ventilation duct is: in α Friction resistance coefficient, unit N·s² / m 4 or Kg / m³ It depends on the material, roughness, and diameter of the duct. L This is the original length of the ventilation duct, in units of... m , U The perimeter of the ventilation duct cross-section, in units of m , S The cross-sectional area of ​​the ventilation duct is expressed in units of... m²； The above formula is transformed into the estimated length after the duct disconnection: At this point, compare the original duct length. L and L h Locate the disconnection point of the air duct: distance from the original air duct outlet ( LL h ) meters.

7. A system for determining the disconnection of a local ventilation fan duct based on operating condition analysis, characterized in that: The method for determining local ventilation fan duct disconnection based on operating condition analysis according to any one of claims 1-6 includes a storage module, a monitoring module, and a calculation and determination module, wherein: The storage module is used to fit and store the performance characteristic curve of the wind turbine at the measured frequency. The monitoring module is used to monitor the static pressure at the fan outlet and the air volume at the duct outlet in real time, and transmit the data to the calculation and judgment module. The static pressure at the fan outlet is obtained by the pressure sensor installed, and the air volume at the duct outlet is obtained by the air volume sensor installed at the duct outlet. The calculation and judgment module is used to determine whether the change in the monitored value exceeds the historical normal fluctuation range, and to calculate and locate the location of the duct disconnection fault.

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