Radial and axial airflow control methods for vortex dust control devices

Abstract

This invention belongs to the field of dust control devices, specifically a method for regulating radial and axial airflow in vortex dust control devices. Addressing the problem of radial and axial airflow distribution in vortex dust control devices, it proposes a method to regulate radial and axial airflow by monitoring the fan frequency. A laboratory test system consisting of a forced-flow fan, a vortex dust control device, and test piping was constructed. The radial and axial airflow distribution law was obtained by using the cross-sectional dynamic pressure method at different frequencies of the forced-flow fan and the vortex fan: Forced-flow airflow Q... 压 and axial air volume Q 轴 The airflow distribution is monotonically increasing with the frequency f1 of the forced draft fan and monotonically decreasing with the frequency f2 of the vortex fan. Based on the radial-axial airflow distribution law, airflow control models were established as a linear function of 5f1-f2 and a quadratic function of f1 / f2. Finally, experimental verification showed that the calculated values ​​of the models were basically consistent with the measured values, indicating that the control model had good accuracy.

Description

Technical Field

[0001] This invention belongs to the field of dust control devices and relates to a method for regulating radial and axial airflow in a vortex dust control device. Background Technology

[0002] With the continuous improvement of mechanization, dust hazards in fully mechanized tunneling faces are becoming increasingly prominent. Long-pressure short-extraction ventilation and dust removal is one of the most common dust control methods in coal mine fully mechanized tunneling faces. At the end of the pressurized ventilation duct, dust control devices such as wall-mounted ventilation ducts or vortex ventilation ducts are used to divert part of the airflow from the axial airflow and allow it to flow out radially, preventing the dust at the face from spreading backward. Studies have shown that when the radial and axial airflow distribution is reasonable, the dust control device has a good dust control effect.

[0003] Currently, the airflow control of wall-mounted ventilation ducts relies on manual adjustment of the radial and axial outlet sizes to distribute the radial and axial airflow. This adjustment process is time-consuming and inconvenient, making it difficult to meet the dust control goals of multi-parameter dynamic coordinated control in tunneling faces. For vortex ventilation ducts, adjusting the radial and axial airflow by changing the vortex fan frequency is a feasible method; however, the impact of vortex fan frequency changes on radial and axial airflow is unclear. Therefore, achieving precise monitoring and control of the radial and axial airflow of dust control devices is crucial for continuous and efficient dust removal in tunneling faces, and also lays the foundation for key parameter monitoring in intelligent dust removal at tunneling faces. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for regulating the radial and axial air volume of a vortex dust control device, so as to achieve accurate monitoring and regulation of the radial and axial air volume of the dust control device.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for regulating radial and axial airflow in a vortex dust control device, comprising the following steps:

[0006] S1, construct a test system consisting of a forced-in fan, an eddy current dust control device and a test pipeline, and equip it with a compensated micro-manometer and a frequency converter. The eddy current dust control device includes an eddy current duct and an eddy current fan.

[0007] S2, turn on the forced air blower at the set frequency, and then turn on the vortex blower at the set frequency. After the flow field stabilizes, use a compensated micro-manometer to test the dynamic pressure of the pipe section. The test sections are located at the front and rear test pipes respectively. The forced air volume is tested at the front test pipe and the axial air volume is tested at the rear test pipe.

[0008] S3. Collect the compressed air volume and axial air volume at different frequencies. It is found that the compressed air volume and axial air volume have a consistent increase and decrease pattern with the frequency. The compressed air volume is positively correlated with the frequency of the compressed air fan and negatively correlated with the frequency of the vortex fan. Similarly, the axial air volume is positively correlated with the frequency of the compressed air fan and negatively correlated with the frequency of the vortex fan.

[0009] S4, select the compressed air volume Q 压 and axial air volume Q 轴 As a function, a mathematical relationship is established with the frequency f1 of the forced draft fan and the frequency f2 of the vortex fan, thereby establishing a radial and axial airflow control model, namely:

[0010] Q 压 =1.68(5f1-f2)-143.66;

[0011] Q 轴 =100.73(f1 / f2)2-77.22(f1 / f2)-16.67;

[0012] Radial air volume is the compressed air volume Q 压 and axial air volume Q 轴 Difference:

[0013] Q 径 =Q 压 -Q 轴 =1.68(5f1-f2)-100.73(f1 / f2)2+77.22(f1 / f2)-126.99;

[0014] S5. The model calculation results were verified by experimental measurement. The error between the model calculation value and the measured value was compared to verify the accuracy of the air volume control model.

[0015] Optionally, two frequency converters are provided, one to control the forced-flow fan and the other to control the vortex fan.

[0016] The beneficial effects of this invention are as follows: This invention studies the distribution law of radial and axial air volume by the frequency of the vortex fan through radial and axial air distribution test of the vortex dust control device, and then establishes a radial and axial air volume control model, providing a basis and support for intelligent dust removal and air control in tunneling faces.

[0017] 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. Detailed Implementation

[0018] 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 also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0019] This invention relates to a method for regulating radial and axial airflow in a vortex dust control device, comprising the following steps:

[0020] S1, construct a test system consisting of a forced-in fan, an eddy current dust control device and a test pipeline, and equip it with a compensated micro-manometer and a frequency converter. The eddy current dust control device includes an eddy current duct and an eddy current fan.

[0021] In this embodiment, two frequency converters are provided, one to control the forced-flow fan and the other to control the vortex fan;

[0022] S2, turn on the forced air blower at the set frequency, and then turn on the vortex blower at the set frequency. After the flow field stabilizes, use a compensated micro-manometer to test the dynamic pressure of the pipe section. The test sections are located at the front and rear test pipes respectively. The forced air volume is tested at the front test pipe and the axial air volume is tested at the rear test pipe.

[0023] In this embodiment, the frequencies of the forced-flow fan are set to 50Hz, 45Hz, and 40Hz, respectively, and the frequencies of the vortex fan are set to 50Hz, 45Hz, 40Hz, 35Hz, and 30Hz, respectively.

[0024] In this embodiment, each measuring point is tested three times, and the arithmetic mean p is taken. di The average dynamic pressure value of the cross section, which serves as the dynamic pressure value at the measuring point, is calculated using the following formula:

[0025]

[0026] The air volume of the cross section is calculated using the following formula:

[0027]

[0028] In the formula, Q represents the air volume under standard conditions, expressed in meters (m). 3 / h;K p Pitot tube correction factor; p d The average dynamic pressure at the measured cross-section, Pa; B a Atmospheric pressure, kPa; Ambient temperature, °C; Average static pressure, kPa; A, cross-sectional area of ​​the measuring point, m² 2 ;

[0029] S3. Based on the compressed air volume and axial air volume at different frequencies, it is found that the compressed air volume and axial air volume have a consistent increase and decrease pattern with the frequency. The compressed air volume is positively correlated with the frequency of the compressed air fan and negatively correlated with the frequency of the vortex fan. Similarly, the axial air volume is positively correlated with the frequency of the compressed air fan and negatively correlated with the frequency of the vortex fan.

[0030] S4, while the radial air volume increases monotonically at 45Hz and 50Hz frequencies of the forced draft fan, but is not applicable at 40Hz. The radial-to-axial air volume ratio increases first and then decreases at 40Hz and 45Hz frequencies of the forced draft fan, but is not applicable at 50Hz. Therefore, the forced draft air volume Q is selected. 压 and axial air volume Q 轴 As a function, a mathematical relationship is established with the frequency f1 of the forced draft fan and the frequency f2 of the vortex fan, thereby establishing a radial and axial airflow control model, namely:

[0031] Using 5f1-f2 as the x-axis and Q as the y-axis... 压 Using the ordinate, establish a linear function Q. 压 =1.68(5f1-f2)-143.66, with a correlation coefficient of 0.89;

[0032] Using f1 / f2 as the x-axis and Q as the y-axis... 轴 Using the ordinate, establish a quadratic function Q. 轴 =100.73(f1 / f2)2-77.22(f1 / f2)-16.67, correlation coefficient 0.98;

[0033] Radial air volume is the compressed air volume Q 压 and axial air volume Q 轴 Difference:

[0034] Q 径 =Q 压 -Q 轴 =1.68(5f1-f2)-100.73(f1 / f2)2+77.22(f1 / f2)-126.99;

[0035] S5. The model calculation results were verified by experimental measurement. The error between the model calculation value and the measured value was compared to verify the accuracy of the air volume control model. See Table 1.

[0036]

[0037] Table 1 Comparison of calculated and measured values

[0038] As shown in Table 1, the maximum absolute error in the forced air volume is 7.2 m³. 3 / min, the maximum absolute error of axial airflow is 3.5m 3 / min, the maximum absolute error of radial airflow is 4.2m 3 / min, with high accuracy.

[0039] 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 regulating radial and axial airflow in a vortex dust control device, characterized in that, Includes the following steps: S1, construct a test system consisting of a forced-in fan, an eddy current dust control device and a test pipeline, and equip it with a compensated micro-manometer and a frequency converter. The eddy current dust control device includes an eddy current duct and an eddy current fan. S2, turn on the forced air blower at the set frequency, and then turn on the vortex blower at the set frequency. After the flow field stabilizes, use a compensated micro-manometer to test the dynamic pressure of the pipe section. The test sections are located at the front and rear test pipes respectively. The forced air volume is tested at the front test pipe and the axial air volume is tested at the rear test pipe. S3. Collect the compressed air volume and axial air volume at different frequencies. It is found that the compressed air volume and axial air volume have a consistent increase and decrease pattern with the frequency. The compressed air volume is positively correlated with the frequency of the compressed air fan and negatively correlated with the frequency of the vortex fan. Similarly, the axial air volume is positively correlated with the frequency of the compressed air fan and negatively correlated with the frequency of the vortex fan. S4, select the compressed air volume Q 压 and axial air volume Q 轴 As a function, a mathematical relationship is established with the frequency f1 of the forced draft fan and the frequency f2 of the vortex fan, thereby establishing a radial and axial airflow control model, namely: Q 压 =1.68(5f1-f2)-143.66; Q 轴 =100.73(f1 / f2)2-77.22(f1 / f2)-16.67; Radial air volume is the compressed air volume Q 压 and axial air volume Q 轴 Difference: Q 径 =Q 压 -Q 轴 =1.68(5f1-f2)-100.73(f1 / f2)2+77.22(f1 / f2)-126.99; S5. The model calculation results were verified by experimental measurement. The error between the model calculation value and the measured value was compared to verify the accuracy of the air volume control model.

2. The radial and axial airflow regulation method of the vortex dust control device according to claim 1, characterized in that: Two frequency converters are installed, one to control the forced-flow fan and the other to control the vortex fan.

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