Self-adaptive control method for operating condition of coal mine gas extraction pump

Abstract

The present application relates to a kind of coal mine gas extraction pump operating condition self-adaptive control method, belong to coal mine gas disaster prevention technical field.The method includes the following steps: S1: the quantitative relationship of three working condition parameters of coal mine gas extraction pump extraction flow, extraction negative pressure, pump speed is built;S2: real-time monitoring gas extraction pump operating parameter;S3: calculate the matching degree of gas extraction pump extraction capacity and actual extraction amount;S4: according to the quantitative relationship model, calculate the target speed of gas extraction pump adjustment and the target power frequency of adjustment;S5: adjust the power frequency of gas extraction pump motor gradually close to the target power frequency of adjustment.The coal mine gas extraction pump operating condition self-adaptive control method provided by the present application provides a technical path for the automatic control technology of gas extraction pump operation with extraction demand, supports the realization of coal mine gas extraction pump station unmanned management and control.

Description

Technical Field

[0001] This invention belongs to the field of coal mine gas disaster prevention and control technology, and relates to an adaptive control method for the operating conditions of coal mine gas extraction pumps. Background Technology

[0002] Coal and gas outbursts and gas explosions are among the most serious accidents in coal production. Regulations require that high-gas and outburst-prone coal seams must undergo gas drainage, and coal mining can only commence after the drainage process meets standards. Gas drainage pumps are a crucial component of coal mine gas drainage systems, providing power for the extraction and transport of underground gas.

[0003] The "GB50471-2018 Design Standard for Coal Mine Gas Drainage Engineering" requires that the capacity of gas drainage equipment should meet the maximum gas drainage volume and maximum negative pressure requirements within the service range or service life of the drainage system for 10 to 15 years. Furthermore, the "Interim Provisions on Compliance of Coal Mine Gas Drainage Standards" stipulates that the installed capacity of the operating drainage pump should not be less than twice the flow rate corresponding to the gas drainage volume required to meet standards. According to these regulations, during normal drainage periods before a coal mine reaches full production capacity or before the gas drainage system fully covers its service area, the drainage capacity of the gas drainage pump has a significant margin exceeding the underground gas drainage demand, resulting in a situation of "overcapacity." Currently, the power of gas drainage pumps is often hundreds of kilowatts, and in large mines, the power of gas drainage pumps even exceeds 1000 kilowatts. If the actual operating conditions of the gas drainage pump exceed the actual gas drainage volume, it will not only cause abnormal operating conditions such as "pump stalling" but also result in a large amount of energy waste. Currently, most coal mines use water ring vacuum pumps as gas extraction pumps. Equipped with variable frequency motors and frequency converters, the pump speed can be adjusted to control the pump's operating conditions. However, due to the lack of relevant adjustment guidelines and methods, technicians find it difficult to accurately determine the reasonable speed range of the gas extraction pump. Therefore, automatic control of the gas extraction pump according to extraction needs has not yet been achieved. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an adaptive control method for the operating conditions of a coal mine gas extraction pump, which automatically adjusts the pump speed according to the actual gas extraction volume underground, so that the pumping capacity of the pump matches the extraction demand, thereby ensuring the normal operation of the pump and saving energy and reducing consumption.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An adaptive control method for the operating conditions of coal mine gas extraction pumps, comprising the following steps:

[0007] S1: Construct the quantitative relationship between three operating parameters of coal mine gas extraction pump: extraction flow rate, extraction negative pressure, and pump speed;

[0008] S2: Real-time monitoring of gas extraction pump operating parameters;

[0009] S3: Calculate the matching degree between the gas extraction pump capacity and the actual extraction volume;

[0010] S4: Calculate the target rotational speed and target power supply frequency of the gas extraction pump based on the quantitative relationship model;

[0011] S5: Adjust the power supply frequency of the gas extraction pump motor to gradually approach the target power supply frequency.

[0012] Optionally, S1 specifically includes the following steps:

[0013] S11: Based on the characteristic curves of the extraction flow rate Q and extraction negative pressure P under typical pump speeds, a cubic polynomial is used for numerical fitting to obtain the QP relationship model under different pump speeds r:

[0014] Q = AP 3 +BP 2 +CP+D

[0015] Where A, B, C, and D are coefficients obtained from numerical fitting. Coefficients A, B, and C do not change with rotational speed, while coefficient D is a variable related to rotational speed.

[0016] S12: Perform a linear fit between the coefficient D and the corresponding rotational speed r to obtain the Dr relationship model:

[0017] D = Er + F

[0018] Where E and f are the coefficients obtained from linear fitting;

[0019] S13: By combining the QP relationship model and the Dr relationship model, we obtain the QPr relationship model, which characterizes the relationship between the three parameters of gas extraction pump: extraction flow rate Q, extraction negative pressure P, and pump speed r.

[0020] Q = AP 3 +BP 2 +CP+Er+F

[0021] Optionally, S2 specifically includes the following steps:

[0022] Sensors capable of measuring extraction flow rate and extraction negative pressure in real time are installed on the inlet side pipeline of the gas extraction pump, and sensors capable of measuring pump speed in real time are installed at the impeller shaft of the gas extraction pump to monitor the operating parameters of the gas extraction pump.

[0023] Optionally, S3 specifically includes the following steps:

[0024] S31: Set the matching threshold δ' for determining whether to start adjustment, where δ' is a percentage less than 1, set to 80% to 90%;

[0025] S32: Substitute the measured negative pressure value and pump speed value in S2 into the QPr relationship model to calculate the gas extraction capacity η of the gas extraction pump;

[0026] S33: Calculate the matching degree δ of the actual extraction volume:

[0027] δ=Q / η

[0028] S34: Compare δ and δ'. If δ ≥ δ', return to S2. If δ < δ', proceed to S4.

[0029] Optionally, S4 specifically includes the following steps:

[0030] S41: Substitute the measured extraction flow rate and the required negative pressure value into the QPr relationship model to calculate the target speed r' of the gas extraction pump.

[0031] S42: Calculate and adjust the target power supply frequency according to the fr relationship model between power supply frequency and motor speed:

[0032] f′=r′×i×p / 60

[0033] Where f' is the target power supply frequency, P is the number of pole pairs of the rotating magnetic field of the pump motor, and i is the transmission ratio of the pump reducer. If there is no reducer, then i = 1.

[0034] Optionally, S5 specifically includes the following steps:

[0035] S51: Substituting the minimum and maximum allowable speeds of the gas extraction pump into the fr relationship model, respectively, yields the minimum allowable power supply frequency f that guarantees the normal operation of the gas extraction pump. min-1 and maximum allowable power supply frequency f max-1 ;

[0036] S52: Calculate the adjustable range of the power supply frequency {f min f max}:

[0037] f min =max{f min-1 ,f min-2 ,f min-3}

[0038] f max =min{f max-1 ,f max-2 ,f max-3}

[0039] Where f min-2 and f max-2 These are the minimum and maximum variable frequencies of the gas extraction pump motor, respectively; f min-3 and f max-3 These are the minimum and maximum adjustable frequencies of the frequency converter, respectively.

[0040] S53: If f' < f min Then set f' to f min Then proceed to S6; if f'>f max Then set f' to f max Then proceed to S6; if f min ≤f'≤f max , directly enter S6.

[0041] Optionally, S6 specifically includes the following steps:

[0042] S61: Set the adjustment step Δf of the power supply frequency of the gas extraction pump motor to 1~5Hz;

[0043] S62: Adjust the power supply frequency of the gas extraction pump motor to be close to the target power supply frequency according to the adjustment step Δf, and maintain the power supply frequency stable for a certain period of time. If the stable operation time is greater than 2 hours, return to S3 and continue to execute S3 to S6 until δ≥δ' and then end this adjustment.

[0044] The beneficial effects of this invention are as follows: Based on the operating characteristics of gas drainage pumps, this invention provides a quantitative method for determining the matching degree between the pumping capacity and drainage demand, and for determining a reasonable operating speed of the pump. It also provides a process flow for gradually adjusting the pump speed and power supply frequency, avoiding large fluctuations in drainage parameters caused by over-adjustment, and further improving the reliability of the adjustment. The adaptive control method for the operating conditions of coal mine gas drainage pumps provided by this invention offers a technical path for the automatic control technology of gas drainage pump operation according to drainage demand, supporting the realization of unmanned management and control of coal mine gas drainage pump stations.

[0045] 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

[0046] 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:

[0047] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0048] 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.

[0049] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures, and should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0050] In the accompanying 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 terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0051] Please see Figure 1 An adaptive control method for the operating conditions of coal mine gas extraction pumps is provided, comprising the following steps:

[0052] S1: Construct the quantitative relationship between three operating parameters of coal mine gas extraction pump: extraction flow rate Q, extraction negative pressure P, and pump speed r.

[0053] S2: Real-time monitoring of gas extraction pump operating parameters;

[0054] S3: Calculation of the matching degree δ between the gas extraction pump capacity and the actual extraction volume;

[0055] S4: Calculate the target rotational speed and target power supply frequency of the gas extraction pump based on the quantitative relationship model;

[0056] S5: Adjust the power supply frequency of the gas extraction pump motor to gradually approach the target power supply frequency.

[0057] S1: Construct a quantitative relationship model for the drainage flow rate, drainage negative pressure, and pump speed of coal mine gas extraction pumps.

[0058] S11: Based on the characteristic curves of the extraction flow rate Q and extraction negative pressure P under typical speed of the gas extraction pump, a cubic polynomial is used for numerical fitting to obtain the QP relationship model under different speed r conditions.

[0059] Q = AP 3 +BP 2 +CP+D

[0060] Where A, B, C, and D are coefficients obtained from numerical fitting. Coefficients A, B, and C do not change with rotational speed, while coefficient D is a variable related to rotational speed.

[0061] S12: Linearly fit the coefficient D with the corresponding rotational speed r to obtain the Dr relationship model D=Er+F, where E and f are the coefficients obtained from the linear fitting.

[0062] S13: By combining the QP relationship model and the Dr relationship model, we can obtain the QPr relationship model, which characterizes the relationship between the three parameters of gas extraction pump: extraction flow rate Q, extraction negative pressure P, and pump speed r.

[0063] Q = AP 3 +BP 2 +CP+Er+F

[0064] S2: Real-time monitoring of gas extraction pump operating parameters

[0065] Sensors that can measure the extraction flow rate and extraction negative pressure in real time are installed on the inlet side pipeline of the gas extraction pump, and sensors that can measure the pump speed in real time are installed at the impeller shaft of the gas extraction pump, so as to monitor the operating parameters of the gas extraction pump in real time.

[0066] S3: Calculation and Judgment of the Matching Degree δ between Gas Extraction Pump Capacity and Actual Extraction Volume

[0067] S31: Set the matching threshold δ' for determining whether to initiate adjustment. δ' is a percentage less than 1, typically set to 80%–90%.

[0068] S32: Substitute the measured negative pressure value and pump speed value in S2 into the QPr relationship model to calculate the gas extraction capacity η of the gas extraction pump;

[0069] S33: Calculate the matching degree δ according to the following formula.

[0070] δ=Q / η

[0071] S34: Compare δ and δ'. If δ ≥ δ', return to S2. If δ < δ', proceed to S4.

[0072] S4: Calculate the target speed and target power supply frequency for adjusting the gas extraction pump.

[0073] S41: Substitute the measured extraction flow rate and the required negative pressure value into the QPr relationship model to calculate the target speed r' of the gas extraction pump.

[0074] S42: Calculate and adjust the target power supply frequency according to the fr relationship model between power supply frequency and motor speed.

[0075] f′=r′×i×p / 60

[0076] Where f' is the target power supply frequency, P is the number of pole pairs of the rotating magnetic field of the pump motor, and i is the transmission ratio of the pump reducer. If there is no reducer, then i = 1.

[0077] S5: Determine whether the target power supply frequency exceeds the adjustable range of the gas extraction pump.

[0078] S51: Substituting the minimum and maximum allowable speeds of the gas extraction pump into the fr relationship model, respectively, yields the minimum allowable power supply frequency f that guarantees the normal operation of the gas extraction pump. min-1 and maximum allowable power supply frequency f max-1 ;

[0079] S52: Calculate the adjustable range of the power supply frequency {f min f max}

[0080] f min =max{f min-1 ,f min-2 ,f min-3}

[0081] f max =min{f max-1 ,f max-2 ,f max-3}

[0082] Where f min-2 and f max-2 These are the minimum and maximum variable frequencies of the gas extraction pump motor, respectively; f min-3 and f max-3 These are the minimum and maximum adjustable frequencies of the frequency converter, respectively.

[0083] S53: If f' < f min Then set f' to f min Then proceed to S6; if f'>f max Then set f' to f max Then proceed to S6; if f min ≤f'≤fmax Enter S6 directly;

[0084] S6: Adjust the step distance according to the power supply frequency to bring the power supply frequency of the gas extraction pump motor close to the target power supply frequency.

[0085] S61: Set the step size Δf for adjusting the power supply frequency of the gas extraction pump motor, which is generally 1 to 5 Hz;

[0086] S62: Adjust the power supply frequency of the gas extraction pump motor to be close to the target power supply frequency according to the adjustment step Δf, and maintain the power supply frequency to run stably for a certain period of time. The stable running time is generally greater than 2 hours. Then return to S3 and continue to execute S3 to S6 until δ≥δ' and then end this adjustment.

[0087] 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. An adaptive control method for the operating conditions of a coal mine gas extraction pump, characterized in that: The method includes the following steps: S1: Construct a quantitative relationship model for three operating parameters of a coal mine gas extraction pump: extraction flow rate, extraction negative pressure, and pump speed; specifically including the following steps: S11: Extraction flow rate based on typical speed of gas extraction pump Q and extraction negative pressure P The characteristic curves were numerically fitted using a cubic polynomial to obtain the results for different pump speeds. r Under the conditions Q - P Relational model: in a, b, c, d The coefficients are obtained from numerical fitting. a, b, c The coefficient does not change with rotational speed. D For variables related to rotational speed; S12: [The coefficient is...] D With the corresponding speed r Perform linear fitting to obtain D-r Relational model: in E, f These are the coefficients obtained from linear fitting; S13: Will QP Relational Model and D-r By combining the relational models, we can obtain the characteristic of the gas extraction pump flow rate. Q Extraction negative pressure P Pump speed r The relationship between the three parameters QPr Relational model: S2: Real-time monitoring of gas extraction pump operating parameters; S3: Calculate the matching degree between the gas extraction pump's extraction capacity and the actual extraction volume; specifically including the following steps: S31: Set the matching degree threshold for determining whether to initiate adjustment. , For percentages less than 1, set to 80%–90%; S32: Substitute the measured extraction negative pressure value and pump speed value from S2 into... QPr In the relational model, the gas extraction capacity of the gas extraction pump is calculated. ; S33: Calculate the matching degree of actual sampling volume : S34: Comparison and ,like If, then return S2, if Then proceed to S4; S4: Calculate the target speed and target power supply frequency of the gas extraction pump based on the quantitative relationship model of gas extraction flow rate, extraction negative pressure, and pump speed. ; S5: Gradually adjust the power supply frequency of the gas extraction pump motor to approach the target power supply frequency; specifically, this includes the following steps: S51: Substitute the minimum and maximum permissible speeds of the gas extraction pump into... In the relational model, the minimum allowable power supply frequency to ensure the normal operation of the gas extraction pump is obtained. and maximum allowable power supply frequency ; S52: Calculate the adjustable range of the power supply frequency. : in and These are the minimum and maximum variable frequencies of the gas extraction pump motor, respectively. and These are the minimum and maximum adjustable frequencies of the frequency converter, respectively. S53: If Then Set as Then enter S6; if Then Set as Then enter S6; if Enter S6 directly; S6 specifically includes the following steps: S61: Set the step size for adjusting the power supply frequency of the gas extraction pump motor. The frequency range is 1–5 Hz. S62: Press to adjust step distance Adjust the power supply frequency of the gas extraction pump motor to be close to the target power supply frequency, and maintain the power supply frequency stable for a certain period of time, with the stable operating time being greater than 2. h Then return to S3 and continue executing S3 to S6 until... This adjustment will then be concluded.

2. The adaptive control method for the operating conditions of a coal mine gas extraction pump according to claim 1, characterized in that: S2 specifically includes the following steps: Sensors capable of measuring extraction flow rate and extraction negative pressure in real time are installed on the inlet side pipeline of the gas extraction pump, and sensors capable of measuring pump speed in real time are installed at the impeller shaft of the gas extraction pump to monitor the operating parameters of the gas extraction pump.

3. The adaptive control method for the operating conditions of a coal mine gas extraction pump according to claim 1, characterized in that: S4 specifically includes the following steps: S41: Substitute the measured extraction flow rate and the required negative pressure value into the input. QPr In the relational model, the target rotational speed of the gas extraction pump is calculated. ; S42: According to the power supply frequency and motor speed f-r The relational model calculates the adjustment of the target power supply frequency: in, To adjust the target power supply frequency, P Let be the number of pole pairs of the rotating magnetic field of the extraction pump motor. i This refers to the transmission ratio of the pump reducer; if there is no reducer, then... i =1.

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