A regulating system and method for dynamically stabilizing the working negative pressure of a drainage pump

Abstract

The present invention relates to a regulating system and method for dynamically stabilizing the working negative pressure of a pumping unit, belonging to the technical field of coal mine gas drainage control. The regulating system mainly includes a shunt pipe, a branch regulating pipe, a branch regulating valve, a collecting pipe, a negative pressure sensor, and a main control unit. One end of the shunt pipe is connected to the main water inlet pipe, and the other end is connected to the collecting pipe through the branch regulating pipe. The other end of the collecting pipe is connected to the pumping unit. The branch regulating valve is arranged on the branch regulating pipe. The negative pressure sensor is arranged on the air inlet pipe. The branch regulating valve and the negative pressure sensor are respectively connected to the main control unit. The regulating method is to adjust the opening degree of the branch regulating valve by comparing the negative pressure value detected by the negative pressure sensor with the preset negative pressure value, so as to control the working liquid flow rate and adjust the negative pressure of the pumping unit. The present invention can quickly and dynamically stabilize the working negative pressure of the pumping unit and ensure the safety of the drainage system.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine gas drainage control, and relates to a regulating system and method for dynamically stabilizing the working negative pressure of a drainage pump. Background Technique

[0002] Gas drainage is the fundamental measure for coal mine gas control. Equipment such as drainage pumps, electric valves, and drainage pipe networks are used to transport the gas stored in the underground coal seams to the ground for utilization or evacuation, ensuring the safe production of coal mines. In order to ensure a constant orifice negative pressure underground in the coal mine and prevent the drainage negative pressure from fluctuating greatly, which may cause safety hazards such as borehole collapse or coal seam spontaneous combustion, a stable drainage negative pressure needs to be provided by a ground power source (drainage pump). When the underground drainage pipe network is adjusted or water accumulates in the pipeline, the working negative pressure of the drainage pump will fluctuate. At this time, the working negative pressure needs to be adjusted to the expected value.

[0003] The working negative pressure of the drainage pump is related to both the rotational speed and the water supply volume of the drainage pump. Some coal mines use frequency converters to adjust the rotational speed of the drainage pump, thereby adjusting the working negative pressure of the drainage pump. However, most coal mines do not use frequency converter control and still use direct high-voltage starting and soft starters to control the drainage pump. The drainage negative pressure cannot be adjusted by adjusting the working rotational speed of the drainage pump. Therefore, it is necessary to adjust the water supply volume of the drainage pump to adjust the drainage negative pressure. The water supply volume of the drainage pump is generally designed according to the maximum working load during factory production, and the water supply pipe diameter is relatively large, approximately between DN50 - DN150. However, during actual use, the drainage pump does not work under full load, and at this time, the required water supply volume is relatively small. The water inflow is adjusted by adjusting the valve on the water inlet pipe of the drainage pump. However, since the opening degree of the inlet valve and the water flow rate passing through the valve are not linearly related, a small valve opening degree will cause a large increase in the water inflow, resulting in the working negative pressure of the drainage pump fluctuating greatly, and the negative pressure of the drainage pump cannot be quickly stabilized, posing a safety hazard and affecting the safe drainage underground. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a regulating system and method for dynamically stabilizing the working negative pressure of a drainage pump, which can quickly and dynamically stabilize the working negative pressure of the drainage pump when negative pressure disturbances occur during the operation of the drainage pump.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] Solution 1: A regulating system for dynamically stabilizing the working negative pressure of a drainage pump, the system includes a shunt pipe 2, a branch regulating pipe 3, a branch regulating valve 4, a collecting pipe 5, a negative pressure sensor 7, and a main control unit 18;

[0007] One end of the shunt pipe 2 is connected to the main water inlet pipe 1, and the other end is connected to the collecting pipe 5 through the branch regulating pipe 3. The other end of the collecting pipe 5 is connected to the extraction pump 17. The branch regulating valve 4 is arranged on the branch regulating pipe 3. The negative pressure sensor 7 is arranged on the air inlet pipe 8. The branch regulating valve 4 and the negative pressure sensor 7 are respectively connected to the main control unit 18 in a signal connection.

[0008] Preferably, the branch regulating pipe 3 includes a first branch regulating pipe to an Nth branch regulating pipe; the branch regulating valve 4 includes a first branch regulating valve to an Nth branch regulating valve; the N branch regulating valves are correspondingly arranged on the N branch regulating pipes one by one.

[0009] Optionally, the system further includes a water flow sensor 6, an air inlet electric valve 9, a steam-water separator 12, a return water regulating valve 13, a high-voltage cabinet / soft starter 14 and a speed reducer 16;

[0010] The water flow sensor 6 is arranged on the collecting pipe 5; the air inlet electric valve 9 is arranged on the air inlet pipe 8; the steam-water separator 12 is respectively connected to the extraction pump 17 and the return water regulating valve 13; the speed reducer 16 is respectively connected to the extraction pump 17 and the motor 15, and the motor 15 is connected to the high-voltage cabinet / soft starter 14; the water flow sensor 6, the air inlet electric valve 9, the return water regulating valve 13 and the high-voltage cabinet / soft starter 14 are all respectively connected to the main control unit.

[0011] Optionally, the main control unit includes a PLC controller and an embedded controller.

[0012] Solution 2: A method for regulating the working negative pressure of a dynamic stable extraction pump, and the method is specifically as follows:

[0013] 1) When the negative pressure of the extraction pump 17 fluctuates, the regulating system starts to regulate the working negative pressure of the extraction pump 17. The main control unit 18 controls to open the first branch regulating valve, and at the same time obtains the negative pressure value P of the negative pressure sensor 7 S , and compares it with the preset negative pressure set value P P ;

[0014] If P S > P P , then regulate the first branch regulating valve to reduce the opening degree;

[0015] If P S < P P , then adjust the opening degree of the first branch regulating valve to the maximum, and at the same time open the second branch regulating valve to adjust its opening degree;

[0016] 2) The main control unit 18 compares P S and P P again:

[0017] If P S > P P, then reduce the opening degree of the second branch regulating valve, or close the second branch regulating valve and return to the regulation of the first branch regulating valve;

[0018] If P S <P P , then adjust the opening degrees of the first and second branch regulating valves to the maximum, and at the same time open the third branch regulating valve for regulation;

[0019] 3) The main control unit 18 compares P S and P P again:

[0020] If P S >P P , then reduce the opening degree of the third branch regulating valve, or close the third branch regulating valve and return to the regulation of the second branch regulating valve;

[0021] If P S <P P , then adjust the opening degrees of the first to third branch regulating valves to the maximum, and at the same time open the fourth branch regulating valve for regulation;

[0022] 4) The main control unit 18 compares P S and P P again:

[0023] If P S >P P , then reduce the opening degree of the (n - 1)-th branch regulating valve, or close the (n - 1)-th branch regulating valve and return to the regulation of the (n - 2)-th branch regulating valve;

[0024] If P S <P P , then adjust the opening degrees of the first to (n - 1)-th branch regulating valves to the maximum, and at the same time open the n-th branch regulating valve for regulation;

[0025] Among them, n represents the serial number of the branch regulating valve, 1 < n ≤ N, and N represents the number of branch regulating valves.

[0026] Furthermore, for the regulation of each branch regulating valve, the method constructs a regulation model for each branch regulating valve by combining proportional, integral, and differential operations:

[0027]

[0028] In the formula, u(k) represents the output of the main control unit; k p represents the proportional coefficient, k i represents the integral coefficient, k d represents the differential coefficient, k d =k p T d, where T represents the sampling period, and T i represents the integration time, and T d represents the differentiation time. k is the sampling sequence number, k = 1, 2, …. e(k) and e(k - 1) respectively represent the deviation signals obtained at the k-th moment and the (k - 1)-th moment, and e(k) = P p -P S ; e(n) = e(k) + e(k - 1) + … + e(0). The adjustment model is implanted into the main control unit through programming, and the branch regulating valve is automatically adjusted through the main control unit.

[0029] The beneficial effects of the present invention are as follows: By dividing the water inlet pipe into multiple branches, the present invention reduces the diameter of the water inlet pipe to improve the linear correlation between the valve opening and the water flow rate passing through, controls the water inflow of the extraction pump, thereby precisely adjusting the working negative pressure of the extraction pump, and can quickly and dynamically stabilize the working negative pressure of the extraction pump when negative pressure disturbances occur during the operation of the extraction pump, ensuring the safety of the extraction system; in addition, based on the signal connection between the control unit and the water flow sensor, the present invention can also be used to dynamically stabilize the working liquid flow rate of the extraction pump.

[0030] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail and preferably with reference to the accompanying drawings, where:

[0032] Figure 1 is a schematic structural diagram of the negative pressure side of the adjustment system;

[0033] Figure 2 is a schematic diagram of the negative pressure control principle of the extraction pump;

[0034] Figure 3 is a schematic diagram of the control principle of the branch regulating valve.

[0035] Reference numerals: 1 - main water inlet pipe; 2 - shunt pipe; 3 - branch regulating pipe; 4 - branch regulating valve; 5 - collecting pipe; 6 - water flow sensor; 7 - negative pressure sensor; 8 - intake pipe; 9 - intake electric valve; 10 - circulation electric valve; 11 - outlet electric valve; 12 - steam-water separator; 13 - return water regulating valve; 14 - high-voltage cabinet / soft starter; 15 - motor; 16 - reducer; 17 - extraction pump; 18 - main control unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the 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. Various details in this specification can also 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 drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0037] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0038] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] The regulation system for the working negative pressure of the dynamic stability extraction pump provided by the present invention is as Figure 1 and Figure 2As shown in the figure, the system includes a main inlet pipe 1, a shunt pipe 2, a branch regulating pipe 3, a branch regulating valve 4, a collecting pipe 5, a water flow sensor 6, a negative pressure sensor 7, an inlet air pipe 8, an inlet air electric valve 9, a circulating electric valve 10, an outlet air electric valve 11, a steam-water separator 12, a return water regulating valve 13, a high-voltage cabinet / soft starter 14, a motor 15, a speed reducer 16, a gas extraction pump 17, and a main control unit 18. One end of the shunt pipe 2 is connected to the main inlet pipe 1, and the other end is connected to the collecting pipe 5 through the branch regulating pipe 3. The other end of the collecting pipe 5 is connected to the gas extraction pump 17. The branch regulating valve 4 is arranged on the branch regulating pipe 3. The negative pressure sensor 7 is arranged on the inlet air pipe 8. The branch regulating valve 4 and the negative pressure sensor 7 are respectively connected to the main control unit 18 by signals. The water flow sensor 6 is arranged on the collecting pipe 5. The inlet air electric valve 9 is arranged on the inlet air pipe 8. The steam-water separator 12 is respectively connected to the gas extraction pump 17 and the return water regulating valve 13, and is also respectively connected to the circulating electric valve 10 and the outlet air electric valve 11. The speed reducer 16 is respectively connected to the gas extraction pump 17 and the motor 15, and the motor 15 is connected to the high-voltage cabinet / soft starter 14. The water flow sensor 6, the inlet air electric valve 9, the return water regulating valve 13, and the high-voltage cabinet / soft starter 14 are all respectively connected to the main control unit.

[0040] Among them, the branch regulating pipe 3 includes a first branch regulating pipe to an Nth branch regulating pipe; the branch regulating valve 4 includes a first branch regulating valve to an Nth branch regulating valve. The N branch regulating valves are arranged on the N branch regulating pipes in one-to-one correspondence. N generally takes a value of 2 to 6, and the range of the branch pipe diameter is DN25 to DN80. By reducing the inlet pipe diameter, the linear correlation between the valve opening and the passing water flow is improved, and the water intake of the gas extraction pump is controlled, so as to accurately adjust the working negative pressure of the gas extraction pump.

[0041] The main control unit 18 includes a PLC controller and an embedded controller, which are mainly responsible for collecting on-site sensor data and controlling devices such as regulating valves and gas extraction pumps; and according to the working negative pressure requirement, controlling the branch regulating valve to automatically enter the next-level regulating valve or automatically return to the previous-level regulating valve for logical operation, and processing the adjustment algorithm of each level to accurately adjust the water supply volume of the gas extraction pump, so as to dynamically stabilize the working negative pressure of the gas extraction pump.

[0042] In the regulating system, the inlet air side (negative pressure side) of the gas extraction pump 17 is connected to the underground boreholes and drill sites to extract the gas stored in the coal seam. The outlet air side (positive pressure side) of the gas extraction pump 17 is connected to the utilization system to provide a gas source for the utilization equipment. The inlet pipe of the gas extraction pump is used to extract the working fluid; the outlet pipe of the gas extraction pump is connected to the working fluid return tank to recycle the working fluid. A negative pressure sensor 7 is installed on the negative pressure pipeline of the gas extraction pump to detect the working negative pressure of the gas extraction pump; a water flow sensor 6 is installed on the inlet pipe of the gas extraction pump near the pump body to detect the water supply flow of the gas extraction pump.

[0043] The method for dynamically adjusting the negative pressure of the extraction pump in the present invention is as follows: When the negative pressure of the extraction pump 17 fluctuates, the adjustment system starts to enter the adjustment state to adjust the working negative pressure of the extraction pump 17. In the branch regulating valve, the regulation of each regulating valve consists of two parts: switch selection and automatic regulation. The switch selection process for each regulating valve is as Figure 3 shown.

[0044] First, the main control unit 18 controls to open the first branch regulating valve, and at the same time obtains the negative pressure value P detected by the negative pressure sensor 7 S , and compares it with the preset negative pressure set value P P ;

[0045] If P S < P P , it indicates that the current water supply volume has met the extraction load demand. At this time, adjust the first branch regulating valve to reduce its opening degree;

[0046] If P S < P P , it indicates that the current system water supply volume cannot meet the extraction load demand. At this time, adjust the opening degree of the first branch regulating valve to the maximum, and at the same time open the second branch regulating valve to adjust its opening degree.

[0047] The main control unit 18 collects the detection value P of the negative pressure sensor 7 again S , and compares P S and P P :

[0048] If P S > P P , it indicates that the current water supply volume has met the extraction load demand. Lower the opening degree of the second branch regulating valve. If the second branch regulating valve has been adjusted to the lowest opening degree, that is, when its valve opening degree is 0, then close the second branch regulating valve and return to the regulation of the first branch regulating valve;

[0049] If P S < P P , it indicates that the current water supply volume is insufficient. Adjust the opening degrees of the first and second branch regulating valves to the maximum, and at the same time open the third branch regulating valve for regulation;

[0050] The main control unit 18 collects the detection value P of the negative pressure sensor 7 again S , and compares P S and P P :

[0051] If P S > P P , lower the opening degree of the third branch regulating valve. If the third branch regulating valve has been adjusted to the lowest opening degree, that is, when its valve opening degree is 0, then close the third branch regulating valve and return to the regulation of the second branch regulating valve;

[0052] If P S <P P , adjust the opening degrees of the first to third branch regulating valves to the maximum, and at the same time open the fourth branch regulating valve for adjustment;

[0053] The main control unit 18 collects the detection value P of the negative pressure sensor 7 again S , and compare P S and P P :

[0054] If P S >P P , then reduce the opening degree of the (n - 1)-th branch regulating valve, or close the (n - 1)-th branch regulating valve and return to the adjustment of the (n - 2)-th branch regulating valve;

[0055] If P S <P P , then adjust the opening degrees of the first to (n - 1)-th branch regulating valves to the maximum, and at the same time open the n-th branch regulating valve for adjustment; where n represents the serial number of the branch regulating valve, 1 < n ≤ N, and N represents the number of branch regulating valves.

[0056] And so on, select to open the next branch regulating valve according to the comparison result of P S and P P , or close the current regulating valve and return to the adjustment of the previous branch regulating valve.

[0057] For the adjustment of each branch regulating valve, the method constructs an adjustment model for each branch regulating valve by combining proportional, integral, and derivative operations:

[0058]

[0059] In the formula, u(k) represents the output of the main control unit; k p represents the proportional coefficient, k i represents the integral coefficient, k d represents the derivative coefficient, k d =k p T d , T represents the sampling period, T i represents the integral time, T d represents the derivative time, k is the sampling serial number, k = 1, 2,...; e(k) and e(k - 1) respectively represent the deviation signals obtained at the k-th moment and the (k - 1)-th moment, e(k) = P p -P S ; e(n) = e(k) + e(k - 1) +... + e(0). The adjustment model is implanted into the main control unit, and the branch regulating valve is automatically adjusted through the main control unit.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A regulating system for dynamically stabilizing the working negative pressure of a drainage pump, characterized in that: The system includes a shunt pipe (2), a branch regulating pipe (3), a branch regulating valve (4), a collecting pipe (5), a negative pressure sensor (7) and a main control unit (18); One end of the shunt pipe (2) is connected to the main water inlet pipe (1), and the other end is connected to the collecting pipe (5) through the branch regulating pipe (3). The other end of the collecting pipe (5) is connected to the extraction pump (17); the branch regulating valve (4) is arranged on the branch regulating pipe (3); the negative pressure sensor (7) is arranged on the air inlet pipe (8); the branch regulating valve (4) and the negative pressure sensor (7) are respectively connected to the main control unit (18); The branch regulating pipe (3) includes a first branch regulating pipe to an Nth branch regulating pipe; the branch regulating valve (4) includes a first branch regulating valve to an Nth branch regulating valve; N branch regulating valves are arranged on N branch regulating pipes in one-to-one correspondence; The system further includes a water flow sensor (6), an air inlet electric valve (9), a steam-water separator (12), a return water regulating valve (13), a high-voltage cabinet / soft starter (14) and a speed reducer (16); The water flow sensor (6) is arranged on the collecting pipe (5); the air inlet electric valve (9) is arranged on the air inlet pipe (8); the steam-water separator (12) is respectively connected to the extraction pump (17) and the return water regulating valve (13); one end of the speed reducer (16) is connected to the extraction pump (17), and the other end is connected to the high-voltage cabinet / soft starter (14) through a motor (15); The water flow sensor (6), the air inlet electric valve (9), the return water regulating valve (13) and the high-voltage cabinet / soft starter (14) are all respectively connected to the main control unit (18).

2. The adjustment system according to claim 1, wherein: The main control unit (18) includes a PLC controller and an embedded controller.

3. A method for adjusting the working negative pressure of a dynamic stable drainage pump for the adjustment system according to claim 1 or 2, characterized in that: The method is specifically as follows: When the negative pressure of the extraction pump (17) fluctuates, the regulation system starts to regulate the working negative pressure of the extraction pump (17). The main control unit (18) controls the opening of the first branch regulating valve and simultaneously obtains the negative pressure value P of the negative pressure sensor (7). S , and compares it with the preset negative pressure set value P P ; If P S > P P , then adjust the first branch regulating valve to reduce the opening degree; If P S <P P , then adjust the opening of the first branch regulating valve to the maximum, and at the same time open the second branch regulating valve to adjust its opening; The main control unit (18) compares P again S and P P : If P S > P P , then reduce the opening degree of the second branch regulating valve, or close the second branch regulating valve and return to the regulation of the first branch regulating valve; If P S <P P , the opening degrees of the first and second branch regulating valves are adjusted to the maximum, and at the same time, the third branch regulating valve is opened for adjustment; The main control unit (18) compares P again S and P P : If P S > P P , then reduce the opening degree of the third branch regulating valve, or close the third branch regulating valve and return to the regulation of the second branch regulating valve; If P S <P P , the opening degrees of the first to third branch regulating valves are adjusted to the maximum, and at the same time, the fourth branch regulating valve is opened for regulation; The main control unit (18) compares P again S and P P : If P S > P P , then reduce the opening of the regulating valve of the (n - 1)-th branch, or close the regulating valve of the (n - 1)-th branch and return to the regulation of the regulating valve of the (n - 2)-th branch; If P S <P P , the opening degrees of the first to (n - 1)th branch regulating valves are adjusted to the maximum, and at the same time, the nth branch regulating valve is opened for regulation; Wherein, n represents the serial number of the branch regulating valve, 1 < n ≤ N, and N represents the number of branch regulating valves.

4. The adjustment method according to claim 3, wherein: For the regulation of each branch regulating valve, the method constructs an adjustment model for each branch regulating valve by combining proportional, integral and differential operations: where \(u(k)\) represents the output of the main control unit; \(k\) p represents the proportional coefficient, \(k\) i represents the integral coefficient, \(k\) d represents the differential coefficient, \(k\) d \(=k\) p \(T\) d where \(T\) represents the sampling period, \(T\) i represents the integral time, \(T\) d represents the differential time, \(k\) is the sampling sequence number, \(k = 1, 2, \cdots\); \(e(k)\) and \(e(k - 1)\) respectively represent the deviation signals obtained at the \(k\)-th moment and the \((k - 1)\)-th moment, \(e(k)=P\) p \(-P\) S ; \(e(n)=e(k)+e(k - 1)+\cdots+e(0)\); The adjustment model is implanted into the main control unit, and the branch regulating valve is automatically adjusted by the main control unit.

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