System and method for non-stop wind reversing of single air door hydraulic adjustable fan in coal mine

Abstract

The present invention relates to a coal mine single damper hydraulically adjustable fan non-stop wind reversing system, comprising a 1# fan system, a 2# fan system, and a 1# PLC and a 2# PLC respectively connected to the 1# fan system and the 2# fan system through control lines, wherein the 1# fan system and the 2# fan system are respectively connected to a high-voltage cabinet and a low-voltage cabinet for power supply; the high-voltage cabinet and the low-voltage cabinet are respectively connected to the 1# PLC and the 2# PLC through control lines; the whole system forms a small Ethernet local area network, adopts a dual redundant system structure, and through a switch, these picture windows, data and alarm information can be transmitted to a remote display screen via Ethernet, so that management personnel can understand the system operation status in the fan room at any time, and realize remote monitoring and control. A method for non-stop wind reversing of a coal mine single damper hydraulically adjustable fan is also provided.

Description

Technical Field

[0001] The invention relates to the field of coal mine ventilation equipment, in particular to a non-stop wind reversing system and method for a coal mine single-throttle hydraulically adjustable fan. Background Art

[0002] Each ventilation shaft in a coal mine usually has two fans, one in use and one as a backup. The fans are normally switched once a month. If there are faults such as overheating, excessive vibration, high-voltage power outage, etc. during operation, the backup fan is usually switched.

[0003] At present, there are mainly the following monthly inspection methods for coal mine fans:

[0004] 1) Stop before starting: first stop the running fan, close its damper, then open the damper of the standby fan and other auxiliary equipment, and wait until the damper of the standby fan is fully opened before starting the standby fan. (This method is most commonly used);

[0005] 2) Start-before-stop method 1: The damper of the standby fan is in the closed state. Start the standby fan first. After the standby fan starts normally, stop the running fan, open the damper of the standby fan, and adjust its operating frequency or blade angle to the preset value (this method is suitable for variable frequency or hydraulic adjustable fans);

[0006] 3) Start-before-stop method 2: When the damper of the standby fan is in the closed state, start the standby fan first. After the standby fan starts normally, adjust the frequency or blade angle of the running fan to the minimum, close the damper of the running fan, and open the damper of the standby fan. When the damper of the running fan is fully closed and the damper of the standby fan is fully opened, adjust the operating frequency or blade angle of the standby fan to the preset value. At this time, the roles of the two fans have been exchanged. When the fan that is started later runs normally, stop the fan that was running before. At this time, the whole reversing process is completed (this method is suitable for variable frequency or hydraulic adjustable fans, and is a safe supplement to the second reversing method);

[0007] 4) Double dampers for non-stop wind-down: This method requires that each fan be equipped with at least two dampers, one of which is a test damper, which is used for fan performance testing or to take in air from the atmosphere when the fan is reversed without stopping the fan; the other is a fan damper, which is used for normal ventilation of the fan. When reversing the fan without stopping the fan, first open the damper of the standby fan, and then start the standby fan. After the standby fan starts normally, open the test damper of the operating fan, open the fan damper of the standby fan, close the fan damper of the operating fan, and close the test damper of the standby fan. At this time, the four dampers of the two fans act simultaneously. When the test damper of the previously operating fan is fully opened and the fan damper is fully closed, the fan damper of the previously standby fan is fully opened and the test damper is fully closed, the roles of the two fans are exchanged. When the switched fan is operating normally, stop the previous operating fan, and the entire reversal process is completed. Adjust the frequency or blade angle of the running fan to the minimum, close the damper of the running fan, and open the damper of the standby fan. When the damper of the running fan is fully closed and the damper of the standby fan is fully opened, adjust the operating frequency or blade angle of the standby fan to the preset value. At this time, the roles of the two fans have been exchanged. When the fan that was started later runs normally, stop the previously running fan. At this time, the entire reversing process is completed (this method is the most commonly used reversing method without stopping the wind).

[0008] In the production process of coal mines, gas over-limit accidents caused by stopping the main ventilation fan when switching fans are extremely common. Because the main ventilation fan follows the traditional "stop and reverse" operation mode, the reversal time is too long or the standby fan cannot be started as expected due to an accident, especially in high-gas mines, the ventilation of the coal mine will lose its function in a short time, which is easy to cause gas over-limit accidents. Therefore, it is particularly important to reverse the machine without stopping the wind, which is also a trend. However, since the air ducts of some old wind shafts are too short, it is not easy to install a test damper. Even if a test damper is reluctantly added, the cost will be very high. Therefore, in some old wind shafts or other reasons where the ventilator cannot be equipped with a test damper, how to safely and reliably reverse the machine with one button without stopping the wind has become a thorny new issue by using the convenient conditions of variable frequency speed regulation or hydraulic adjustment. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a coal mine single-throttle hydraulically adjustable fan non-stop wind reversing system to solve the defects existing in the prior art.

[0010] The technical solution of the present invention to solve the above technical problems is as follows:

[0011] A coal mine single damper hydraulic adjustable fan non-stop wind reversing system includes a 1# fan system, a 2# fan system, and a 1#PLC and a 2#PLC respectively connected to the 1# fan system and the 2# fan system through control lines, wherein the 1# fan system and the 2# fan system are respectively connected to a high-voltage cabinet and a low-voltage cabinet for power supply; the high-voltage cabinet and the low-voltage cabinet are respectively connected to the 1#PLC and the 2#PLC through control lines; the 1# fan system and the 2# fan system have a 1# fan and a 2# fan respectively; the high-voltage cabinet supplies power to the 1# fan and the 2# fan; the 1#PLC and the 2#PLC are respectively connected to a protocol bus bridge through a Profibus bus, and the protocol bus bridge is connected to the high-voltage cabinet through an RS-485 bus for collecting electrical parameters such as motor voltage, current, power, and power factor; the 1#PLC and the 2#PLC are respectively connected to an industrial switch 1 and an industrial switch 2 through a network cable, and the industrial switch 1 and the industrial switch 2 are respectively connected to a display SCAD1 and a display SCAD2; 1#PLC and 2#PLC are connected through bus and network cable, and there are two communication methods, Profibus and S7, to exchange data.

[0012] Furthermore, the 1# ventilator and the 2# ventilator are both hydraulically adjustable fans;

[0013] Further, the 1# ventilator includes the 1# main motor and the fan damper connected thereto, and the hydraulic station connected thereto; the 2# ventilator includes the 2# main motor and the fan damper connected thereto, and the hydraulic station connected thereto; the fan dampers are respectively connected to a fan damper local box; the hydraulic stations are respectively connected to a hydraulic station local box; the fan damper local box and the hydraulic station local box are respectively connected to the 1# PLC and the 2# PLC through control lines at the same time;

[0014] Furthermore, the 1# fan bearing, 1# main motor bearing, and 1# main motor winding are provided with temperature sensors and vibration sensors for detecting the bearing and winding temperatures and bearing vibration signals respectively and transmitting them to the 1# PLC; the 2# fan bearing, 2# main motor bearing, and 2# main motor winding are provided with temperature sensors and vibration sensors for detecting the bearing and winding temperatures and bearing vibration signals respectively and transmitting them to the 2# PLC;

[0015] Further, the 1# ventilator has a vane actuator, a torque switch, a stall switch, and an oil level switch connected to the 1# PLC via a control line; the 2# ventilator has a vane actuator, a torque switch, a stall switch, and an oil level switch connected to the 2# PLC via a control line;

[0016] Furthermore, pressure sensors are provided at the inlet, outlet and impeller of the 1# fan to detect the inlet pressure, outlet pressure and impeller pressure; pressure sensors are provided at the inlet, outlet and impeller of the 2# fan to detect the inlet pressure, outlet pressure and impeller pressure; the negative pressure, total pressure, wind speed and air volume of each fan can be calculated through the inlet pressure, outlet pressure and impeller pressure of each fan and the fan cross section;

[0017] The hydraulic station is provided with an oil pump, a heater, a cooling fan, an oil pressure switch, a filter and a liquid level switch connected with the PLC.

[0018] The present invention also provides a method for a coal mine single-throttle hydraulically adjustable fan to keep the fan in operation, wherein the 1# fan is an in-service fan and the 2# fan is a hot standby fan, which are used to connect to the shaft for exhaust, and specifically include the following steps:

[0019] 1) 1# ventilator operates normally, 2# ventilator is on standby;

[0020] 2) The damper of the 2# fan is closed, and the 2# fan starts running at the minimum angle;

[0021] 3) When the delay time of the 2# fan is up, the blades of the 1# fan are adjusted to the reverse angle for operation;

[0022] 4) The blades of the 1# fan are delayed in the reverse operation, the damper of the 2# fan is opened, and the damper of the 1# fan is closed;

[0023] 5) Open the damper of the 2# fan to the full extent, close the damper of the 1# fan to the full extent, adjust the blades of the 1# fan to the minimum angle, and adjust the blades of the 2# fan to the reverse angle;

[0024] 6) The blades of the 1# fan run at the minimum angle, the blades of the 2# fan run at the reverse angle, and the damper of the 1# fan is closed;

[0025] 7) The damper of the 1# fan is fully closed and the blades of the 2# fan are adjusted to the normal angle for operation;

[0026] 8) The damper of the 1# fan is fully closed, the blades of the 1# fan are running at the minimum angle, and the blades of the 2# fan are running at the normal angle;

[0027] 9) The blades of the 2# fan are delayed in running at normal angles, and the 1# fan is stopped;

[0028] Each fan has a damper, which opens when the fan is running normally and closes when the fan stops. The "normal angle" refers to the angle when the fan is running under normal conditions, which can be set on the position machine. The "reverse angle" refers to the angle at which the blades are appropriately lowered during the reverse process without stopping the wind. The value is the normal angle multiplied by a coefficient, which can be set on the position machine.

[0029] The beneficial effects of the present invention are: it solves the problem that each fan has only one damper, and can realize non-stop wind reversal, greatly improving the rapidity and safety of the switching process of the coal mine fan. In addition, the entire system forms a small Ethernet local area network to share all collected data information; with a dual redundant system structure, the system configuration software on the 1#PLC or 2#PLC will reflect the operating status of the entire system to the user through the picture window, and the user can also control the system through the picture window. Through the switch, these picture windows, data and alarm information can be transmitted to a distant display screen via Ethernet, so that the management personnel can understand the system operating status in the fan room at any time and realize remote monitoring and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structural principle of the present invention;

[0031] Figure 2 This is step 1 of the inversion method of the present invention;

[0032] Figure 3 This is step 2 of the inversion method of the present invention;

[0033] Figure 4 This is step 3 of the inversion method of the present invention;

[0034] Figure 5 This is step 4 of the inversion method of the present invention;

[0035] Figure 6 This is step 5 of the inversion method of the present invention;

[0036] Figure 7 This is step 6 of the inversion method of the present invention;

[0037] Figure 8 This is step seven of the inversion method of the present invention;

[0038] Fig. 9 This is step eight of the inversion method of the present invention;

[0039] Fig.10 This is step nine of the inversion method of the present invention; DETAILED DESCRIPTION

[0040] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0041] like Figure 1 As shown, a coal mine single damper hydraulic adjustable fan non-stop wind reversing system includes a 1# fan system, a 2# fan system, and a 1#PLC and a 2#PLC respectively connected to the 1# fan system and the 2# fan system through control lines, wherein the 1# fan system and the 2# fan system are respectively connected to a high-voltage cabinet and a low-voltage cabinet for power supply; the high-voltage cabinet and the low-voltage cabinet are respectively connected to the 1#PLC and the 2#PLC through control lines; the 1# fan system and the 2# fan system have a 1# fan and a 2# fan respectively; the high-voltage cabinet supplies power to the 1# fan and the 2# fan; the 1#PLC and the 2#PLC are respectively connected to a protocol bus bridge through a Profibus bus, and the protocol bus bridge is connected to the high-voltage cabinet through an RS-485 bus for collecting electrical parameters such as motor voltage, current, power, and power factor; the 1#PLC and the 2#PLC are respectively connected to an industrial switch 1 and an industrial switch 2 through a network cable, and the industrial switch 1 and the industrial switch 2 are respectively connected to a display SCAD1 and a display SCAD2 connect;

[0042] Specifically, the 1# ventilator and the 2# ventilator are both hydraulically adjustable fans;

[0043] The whole system consists of 2 sets of PLC cabinets (S7-300), 2 industrial computers, 2 Ethernet switches, etc., that is, it adopts the typical PLC plus host control mode. The control core PLC adopts Siemens S7-300 series, which has multiple communication functions such as Profibus, Modbus, Ethernet and OPC. The system adopts PLC (including Ethernet module) processing control machine monitoring mode, and forms a local area network through the switch. The monitoring system provides visualization, data collection and data monitoring of the production process, and realizes the networking of measurement and control functions. It can realize the "one-key switching" functions such as non-stop wind reversal, fault reversal, power outage reversal, one-key reverse wind, etc., and can remotely and manually control various on-site equipment in the control cabinet; the whole system adopts a dual redundant structure to ensure the advancement, stability and reliability of the entire control system;

[0044] As a further improvement of the technical solution of the present invention, the 1# ventilator includes the 1# main motor and the damper connected thereto, and the hydraulic station connected thereto; the 2# ventilator includes the 2# main motor and the damper connected thereto, and the hydraulic station connected thereto; the dampers are respectively connected to a damper local box; the hydraulic stations are respectively connected to a hydraulic station local box; the damper local box and the hydraulic station local box are respectively connected to the 1# PLC and the 2# PLC through control lines at the same time;

[0045] By setting up the local box, the system control mode can be switched to manual mode, which is an emergency start-up mode when the PLC or system fails and cannot be controlled by the automatic program. The operator must have a full understanding of the fan operating conditions and switch the corresponding equipment mode conversion switch required for the fan operation to the "local" position through the local box. Each device can be started and stopped at the remote button on the PLC control cabinet or the equipment site and the upper computer single control screen.

[0046] In order to further enhance the reliability of the entire system, as a further improvement of the technical solution of the present invention, the 1# fan bearing, the 1# main motor bearing, and the 1# main motor winding are provided with a temperature sensor and a vibration sensor for detecting the bearing, the winding temperature and the bearing vibration signal respectively and transmitting them to the 1# PLC; the 2# fan bearing, the 2# main motor bearing, and the 2# main motor winding are provided with a temperature sensor and a vibration sensor for detecting the bearing, the winding temperature and the bearing vibration signal respectively and transmitting them to the 2# PLC;

[0047] Through the above settings, the temperature and vibration of the fan can be monitored in real time. Once the set value is exceeded, an alarm will be issued and displayed on the monitor;

[0048] More specifically, the 1# ventilator has a vane actuator, a torque switch, a stall switch, and an oil level switch connected to the 1# PLC via a control line; the 2# ventilator has a vane actuator, a torque switch, a stall switch, and an oil level switch connected to the 2# PLC via a control line;

[0049] More specifically, pressure sensors are provided at the inlet, outlet and impeller of the 1# fan to detect the inlet pressure, outlet pressure and impeller pressure; pressure sensors are provided at the inlet, outlet and impeller of the 2# fan to detect the inlet pressure, outlet pressure and impeller pressure; the negative pressure, total pressure, wind speed and air volume of each fan can be calculated through the inlet pressure, outlet pressure and impeller pressure of each fan and the fan cross section;

[0050] More specifically, the hydraulic station is provided with an oil pump, a heater, a cooling fan, an oil pressure switch, a filter, and a liquid level switch connected to the PLC;

[0051] The system of the present invention controls the operation and switching of the oil pump motor, heater, and cooling fan of the hydraulic station through PLC, and monitors the oil temperature, oil level, oil pressure, filter status and other signals of the hydraulic station. The electric actuator of the damper is controlled to realize the opening and closing of the damper, and its remote control, over-torque, operation, and in-place signals are monitored. The fan stall signal can be monitored, and the blade angle is automatically reduced when stalled to deviate from the surge zone; when the stall exceeds 120S, the main motor trips; the motor brake device is controlled to realize the rapid braking of the fan, and the position and status of the fan brake are monitored. The control console can be centrally controlled on the display in the monitoring room to control the main equipment such as the fan. Important operation signals and group alarm signals should be displayed on the display, and there should be an alarm. In the case of PLC system failure or no graphic display system, it can still be operated on the power distribution cabinet. The PLC control cabinet should ensure good ventilation and cooling, and have dust prevention measures; all electronic control equipment can work normally for a long time in the ambient temperature range of -5℃-+40℃. The fan start and stop require one-button operation; at the same time, the most original manual control function is retained to ensure that when the PLC system fails, the high and low voltage power supplies and switches are normal, and the on-site manual start function is available.

[0052] At the same time, the system has an automatic switching function, which is described as follows:

[0053] a) Fault shutdown: When the running fan trips due to high voltage power outage or over-temperature, excessive vibration or other tripping signals, the running fan stops and the standby fan is automatically turned on.

[0054] b) One-key reverse operation: When the fan needs to be switched, the system has the functions of one-key reverse operation without stopping the fan and one-key reverse operation.

[0055] Among them, the non-stop wind reversing system: if the reversing process is stalled due to mechanical or electrical reasons of any equipment, the system will automatically determine the fault and give a set recovery time. If the fault is not restored within the specified time, the system will stop the reversing process and restore the state before the reversing.

[0056] In order to prevent the occurrence of "wind grabbing" phenomenon when two fans are connected in parallel, Figure 2-10 As shown, the present invention also discloses a method for non-stopping of a coal mine single-throttle hydraulically adjustable fan, wherein the 1# fan is an operating fan and the 2# fan is a hot standby fan, which are used to connect to the shaft for exhaust, and specifically include the following steps:

[0057] 1) 1# ventilator operates normally, 2# ventilator is on standby;

[0058] 2) The damper of the 2# fan is closed, and the 2# fan starts running at the minimum angle;

[0059] 3) When the delay time of the 2# fan is up, the blades of the 1# fan are adjusted to the reverse angle for operation;

[0060] 4) The blades of the 1# fan are delayed in the reverse operation, the damper of the 2# fan is opened, and the damper of the 1# fan is closed;

[0061] 5) Open the damper of the 2# fan to the full extent, close the damper of the 1# fan to the full extent, adjust the blades of the 1# fan to the minimum angle, and adjust the blades of the 2# fan to the reverse angle;

[0062] 6) The blades of the 1# fan run at the minimum angle, the blades of the 2# fan run at the reverse angle, and the damper of the 1# fan is closed;

[0063] 7) The damper of the 1# fan is fully closed and the blades of the 2# fan are adjusted to the normal angle for operation;

[0064] 8) The damper of the 1# fan is fully closed, the blades of the 1# fan are running at the minimum angle, and the blades of the 2# fan are running at the normal angle;

[0065] 9) The blades of the 2# fan are delayed in running at normal angles, and the 1# fan is stopped;

[0066] Each fan has a damper, which opens when the fan is running normally and closes when the fan stops. The "normal angle" refers to the angle when the fan is running under normal conditions, which can be set on the PLC. The "reverse angle" refers to the angle at which the blades are appropriately lowered during the reverse process without stopping the wind. Its value is the normal angle multiplied by a coefficient, which can be set on the host computer.

[0067] If the machine is stalled due to mechanical or electrical problems in any device during the reversing process, the system will automatically determine the fault and give a set recovery time. If the fault is not restored within the specified time, the system will stop the reversing process and restore the normal ventilation state of the single motor.

[0068] At the same time, in the process of further improvement, we can also refer to the performance curve of the fan, and establish a model based on parameters such as wind pressure, air volume, wind resistance, vibration, etc., and use fuzzy control theory to achieve smooth control of the percentage of switches such as each damper and blade angle.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Coal mine single damper hydraulic adjustable fan non-stop wind reverse system, Features: The invention comprises a 1# fan system, a 2# fan system and a 1#PLC and a 2#PLC respectively connected to the 1# fan system and the 2# fan system through control lines, wherein the 1# fan system and the 2# fan system are respectively connected to a high-voltage cabinet and a low-voltage cabinet for power supply; the high-voltage cabinet and the low-voltage cabinet are respectively connected to the 1#PLC and the 2#PLC through control lines; the 1# fan system and the 2# fan system respectively have a 1# fan and a 2# fan; the high-voltage cabinet supplies power to the 1# fan and the 2# fan; the 1#PLC and the 2#PLC are respectively connected to a protocol bus bridge through a Profibus bus, and the protocol bus bridge is connected to the high-voltage cabinet through an RS-485 bus for collecting electrical parameters of motor voltage, current, power and power factor; the 1#PLC and the 2#PLC are respectively connected to an industrial switch 1 and an industrial switch 2 through a network cable to form a ring network; the industrial switch 1 and the industrial switch 2 are respectively connected to a display SCAD1 and a display SCAD2, wherein the system realizes the non-stop wind reversing operation through the following method: The 1# fan is the operating fan, and the 2# fan is the hot standby fan, which is used to connect to the shaft for exhaust. 1) 1# ventilator operates normally, 2# ventilator is on standby; 2) The damper of the 2# fan is closed, and the 2# fan starts running at the minimum angle; 3) When the delay time of the 2# fan is up, the blades of the 1# fan are adjusted to the reverse angle for operation; 4) The blades of the 1# fan are delayed in the reverse operation, the damper of the 2# fan is opened, and the damper of the 1# fan is closed; 5) Open the damper of the 2# fan to the full extent, close the damper of the 1# fan to the full extent, adjust the blades of the 1# fan to the minimum angle, and adjust the blades of the 2# fan to the reverse angle; 6) The blades of the 1# fan run at the minimum angle, the blades of the 2# fan run at the reverse angle, and the damper of the 1# fan is closed; 7) The damper of the 1# fan is fully closed and the blades of the 2# fan are adjusted to the normal angle for operation; 8) The damper of the 1# fan is fully closed, the blades of the 1# fan are running at the minimum angle, and the blades of the 2# fan are running at the normal angle; 9) The blades of the 2# fan are delayed in running at normal angles, and the 1# fan is stopped; Each fan has a damper, which opens when the fan is running normally and closes when the fan stops. The "normal angle" refers to the angle when the fan is running under normal conditions, which can be set on the PLC. The "reverse angle" refers to the angle at which the blades are appropriately lowered during the reverse process without stopping the wind. Its value is the normal angle multiplied by a coefficient, which can be set on the PLC.

2. According to claim 1, the coal mine single damper hydraulic adjustable fan non-stop wind reverse machine system, Features: The 1# ventilator and the 2# ventilator are both hydraulically adjustable fans.

3. The coal mine single damper hydraulic adjustable fan non-stop wind reversing system according to claim 2, Features: The 1# ventilator includes a 1# main motor and a fan damper connected thereto, and a hydraulic station connected thereto; the 2# ventilator includes a 2# main motor and a fan damper connected thereto, and a hydraulic station connected thereto; the fan dampers are respectively connected to a damper local box; the hydraulic stations are respectively connected to a hydraulic station local box; the fan damper local box and the hydraulic station local box are respectively connected to the 1# PLC and the 2# PLC through control lines at the same time.

4. According to claim 3, the coal mine single damper hydraulic adjustable fan non-stop wind reverse machine system, Features: The 1# fan bearing, 1# main motor bearing, and 1# main motor winding are provided with temperature sensors and vibration sensors for detecting the bearing and winding temperatures and bearing vibration signals respectively and transmitting them to the 1# PLC; the 2# fan bearing, 2# main motor bearing, and 2# main motor winding are provided with temperature sensors and vibration sensors for detecting the bearing and winding temperatures and bearing vibration signals respectively and transmitting them to the 2# PLC.

5. According to claim 4, the coal mine single damper hydraulic adjustable fan non-stop wind reverse machine system, Features: The 1# ventilator has a blade actuator, a torque switch, a stall switch, and an oil level switch connected to the 1# PLC via a control line; the 2# ventilator has a blade actuator, a torque switch, a stall switch, and an oil level switch connected to the 2# PLC via a control line.

6. The coal mine single damper hydraulic adjustable fan non-stop wind reversing system according to claim 5, Features: Pressure sensors are provided at the inlet, outlet and impeller of the 1# fan for detecting the inlet pressure, outlet pressure and impeller pressure; pressure sensors are provided at the inlet, outlet and impeller of the 2# fan for detecting the inlet pressure, outlet pressure and impeller pressure; the negative pressure, total pressure, wind speed and air volume of each fan can be calculated through the inlet pressure, outlet pressure and impeller pressure of each fan and the fan cross-section.

7. The coal mine single damper hydraulic adjustable fan non-stop wind reversing system according to claim 6, Features: The hydraulic station is provided with an oil pump, a heater, a cooling fan, an oil pressure switch, a filter and a liquid level switch connected with the PLC.

8. Method for turning back the machine with single damper hydraulic adjustable fan without stopping in coal mine. Features: The 1# ventilator is the operating ventilator and the 2# ventilator is the hot standby ventilator, which are used to connect to the shaft for exhaust, specifically including the following steps: 1) 1# ventilator operates normally, 2# ventilator is on standby; 2) The damper of the 2# fan is closed, and the 2# fan starts running at the minimum angle; 3) When the delay time of the 2# fan is up, the blades of the 1# fan are adjusted to the reverse angle for operation; 4) The blades of the 1# fan are delayed in the reverse operation, the damper of the 2# fan is opened, and the damper of the 1# fan is closed; 5) Open the damper of the 2# fan to the full extent, close the damper of the 1# fan to the full extent, adjust the blades of the 1# fan to the minimum angle, and adjust the blades of the 2# fan to the reverse angle; 6) The blades of the 1# fan run at the minimum angle, the blades of the 2# fan run at the reverse angle, and the damper of the 1# fan is closed; 7) The damper of the 1# fan is fully closed and the blades of the 2# fan are adjusted to the normal angle for operation; 8) The damper of the 1# fan is fully closed, the blades of the 1# fan are running at the minimum angle, and the blades of the 2# fan are running at the normal angle; 9) The blades of the 2# fan are delayed in running at normal angles, and the 1# fan is stopped; Each fan has a damper, which opens when the fan is running normally and closes when the fan stops. The "normal angle" refers to the angle when the fan is running under normal conditions, which can be set on the PLC. The "reverse angle" refers to the angle at which the blades are appropriately lowered during the reverse process without stopping the wind. Its value is the normal angle multiplied by a coefficient, which can be set on the PLC.

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