Bubble curtain device based on gas pressure feedback

Abstract

The invention provides a bubble curtain device based on gas pressure feedback, which comprises a gas distribution pipe with one end of a closed structure, the other end of the gas distribution pipe is connected with a gas pump through a gas delivery pipe, and a plurality of flow control units are mounted on the gas distribution pipe along the length extension direction; the flow control unit comprises a body, a plurality of first hole channels are formed in the body, the first ends of the first hole channels extend to the top end of the body, the second ends of the first hole channels penetrate through the side wall of an inner cavity of the body, an elastic unit is fixedly installed at the top of the inner cavity, and a sliding block installed in the inner cavity in a sliding mode is arranged below the elastic unit. The sliding block is of a cylindrical structure with a cover plate at the top, and a plurality of air guide grooves matched with the first hole channels to work are formed in the side wall of the sliding block. According to the invention, flow deviation caused by pressure fluctuation at different positions on the gas distribution pipe is effectively compensated, so that the flow of gas discharged by each flow control unit is approximately constant.

Description

Technical Field

[0001] This invention relates to the field of engineering construction technology, and in particular to a bubble curtain device based on gas pressure feedback. Background Technology

[0002] Underwater blasting is a key technology in modern engineering for dealing with hard rock masses and underwater structures. It is widely used in scenarios such as submarine tunnel excavation and port and waterway dredging. However, the underwater shock waves generated by the explosion are prone to damage to surrounding underwater buildings, marine life and monitoring facilities due to their high overpressure peak and slow propagation attenuation, which has become a prominent issue for engineering safety and ecological protection.

[0003] To address this issue, bubble curtain technology has become the mainstream protective method due to its economic efficiency and eco-friendliness. It involves introducing high-pressure gas into a predetermined underwater area through gas distribution pipes, forming a two-phase gas-liquid bubble barrier. When a shock wave passes through the barrier, the bubbles undergo a "compression-expansion-collapse" process, converting some of the shock wave's kinetic energy into internal and thermal energy, thus achieving energy reduction. This is a key solution for balancing blasting efficiency and safety. However, existing bubble curtain technology has three major drawbacks, making it difficult to adapt to complex engineering needs: Firstly, it often uses uniformly distributed perforated gas distribution pipes, see... Figure 9 When gas flows through the gas distribution pipe, gas molecules continuously escape from the outlet holes along the way. Under isothermal conditions with a constant volume of the gas distribution pipe, according to the ideal gas law... The number of gas molecules in the gas distribution pipe The pressure decreases as the flow distance increases, directly affecting the pressure inside the air distribution pipe. The flow rate decreases in a stepwise manner from the inlet to the outlet; and the gas flow in the underwater gas distributor meets the conditions of low-speed, small-pressure-difference adiabatic flow, making the gas orifice flow rate formula applicable. (in This represents the gas volumetric flow rate. For flow coefficient, The area of ​​the air outlet. The pressure difference between the inside and outside of the vent. (Gas density), because the pressure inside the pipe decreases along the pipe, the pressure difference at the outlet. The flow rate decreases with increasing distance from the intake end, resulting in a sharp reduction in the flow rate at the distal exhaust port compared to the proximal end, and the bubble coverage rate drops from over 90% at the proximal end to below 50% at the distal end; combined with the shock wave attenuation efficiency formula ( The actual attenuation efficiency is only 30%-45%, far lower than the ideal value of 60%-70%, indicating low shock wave attenuation efficiency. Secondly, there is no effective anti-backflow structure (which can be addressed using Bernoulli's equation). = Analysis shows that backflow is likely when the water flow velocity is greater than 0.5 m / s. Under typical operating conditions, the gas supply pressure needs to be increased from 0.6 MPa to over 0.9 MPa, combined with the gas supply power formula ( The operating power increased from approximately 428kW to 642kW, resulting in a 50% increase in energy consumption, and problems such as water backflow and high energy consumption were identified. Summary of the Invention

[0004] This application provides a bubble curtain device based on gas pressure feedback. The second end opening of the first channel and the air guide groove form a fluid channel cross-section based on pressure feedback, effectively compensating for flow deviations caused by pressure fluctuations at different locations on the air distribution pipe. This ensures that the gas flow rate discharged from each flow control unit is approximately constant, thereby achieving balanced flow control of the bubble curtain device. The objective of this invention is achieved as follows: A bubble curtain device based on gas pressure feedback includes a gas distribution pipe with a closed structure at one end, and the other end of the gas distribution pipe is connected to a gas pump through a gas delivery pipe. Multiple flow control units are installed on the gas distribution pipe along its length extension direction. The flow control unit includes a body with multiple first channels. The first end of each first channel extends to the top of the body, and the second end of each first channel penetrates the inner wall of the body. An elastic unit is fixedly installed at the top of the inner cavity. Below the elastic unit is a slider that is slidably installed in the inner cavity. The slider is a cylindrical structure with a cover plate at the top. The side wall of the slider has multiple air guide grooves that cooperate with the first channels. The top and bottom of the body have second and third channels, respectively. The second channel communicates with a longitudinal channel on the elastic unit, and the inner cavity communicates with the air distribution pipe through the third channel. When the lower end of the slider moves downward to abut against the bottom end face of the inner cavity, the first channel is isolated from the air guide groove. When the upper end of the slider moves upward and abuts against the lower end of the elastic unit, the first channel and the air guide groove are in a connected state; and as the slider continues to move upward, the elastic unit is compressed, and the effective connection area between the first channel and the air guide groove gradually shrinks.

[0005] The elastic unit is a rubber pad with a central hole.

[0006] The elastic unit includes a spring, one end of which is connected to the body and the other end of which is connected to a pressure plate. The pressure plate has a through hole that communicates with the second channel.

[0007] The flow control unit is connected to the air distribution pipe by welding or threaded connection.

[0008] The slider is a cylindrical structure adapted to the inner cavity, and an annular groove is provided on the side wall of the inner cavity directly opposite the entrance of the first channel.

[0009] The slider is a polygonal prism structure adapted to the inner cavity.

[0010] The first channel includes an axial hole perpendicular to the upper end face of the body and a radial hole communicating with the axial hole, the radial hole communicating with the inner cavity.

[0011] A seal is provided between the slider and the body, and the seal is located below the radial hole.

[0012] A working method for a bubble curtain device based on gas pressure feedback: When working, first place the air distribution pipe at the bottom of the water; When the air pump is not supplying air, water flows from the second channel into the inner cavity of the body through the longitudinal channel on the elastic unit. Under the action of its own weight and water pressure, the slider keeps its lower end face in contact with the bottom end face of the inner cavity. The air guide groove is sealed by the inner cavity side wall of the body, thereby isolating the first channel from the air guide groove, preventing water from entering the inner cavity of the slider from the air guide groove, and avoiding water backflow into the air distribution pipe. When the air pump starts supplying air, the gas flows into the inner chamber of the slider through the air supply pipe, air distribution pipe, and third channel. The air pressure pushes the slider to slide upward. Then the first channel connects with the air guide groove until the top of the slider abuts against the lower end face of the elastic unit. The second end opening of the first channel remains connected to the air guide groove. When the air intake pressure of the third channel increases further, the elastic unit is deformed by pressure, and the effective connection area between the second end opening of the first channel and the air guide groove gradually decreases.

[0013] The present invention has the following beneficial effects: 1. The second end opening of the first channel forms a fluid channel cross section based on pressure feedback between itself and the air guide groove, which effectively compensates for the flow deviation caused by pressure fluctuations at different positions on the air distribution pipe, making the gas flow rate discharged by each flow control unit approximately constant, thereby achieving balanced control of the flow rate of the bubble curtain device; avoiding the problem of sharp reduction in the far-end exhaust flow rate caused by the pressure decreasing along the path in the air distribution pipe in the existing technology.

[0014] 2. The lower end of the slider moves downward to abut against the bottom end of the inner cavity. The air guide groove is sealed by the inner cavity sidewall of the body, thereby isolating the first channel from the air guide groove, preventing water from entering the inner cavity of the slider from the air guide groove, and avoiding backflow of water. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 A schematic diagram of a bubble curtain device based on gas pressure feedback provided in an embodiment of the present invention; Figure 2This is a structural diagram of the slider of the flow control unit provided in the embodiment of the present invention when it is in the first state; Figure 3 This is a structural diagram of the slider of the flow control unit provided in an embodiment of the present invention when it is in the second state; Figure 4 A cross-sectional view of the body provided in an embodiment of the present invention; Figure 5 A schematic diagram of the installation structure of the spring and the pressure plate provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the body provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the first type of slider provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the second type of slider provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the bubble curtain device in the prior art involved in this invention; In the diagram: 1. Air distribution pipe, 1a. Air outlet, 2. Air pump, 3. Flow control unit, 4. Body, 41. First channel, 42. Axial hole, 42a. Radial hole, 42b. Second end opening, 42c. Inner cavity, 43. Bottom end face, 43a. Elastic unit, 44. Spring, 44a. Pressure plate, 44b. Through hole, 44c. Longitudinal channel, 44d. Slider, 45. Air guide groove, 46. Second channel, 47. Third channel, 48. Annular groove, 49. Seal, 5. Air pipe connector, 6. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figure 1-8 The present invention provides a technical solution: A bubble curtain device based on gas pressure feedback includes a gas distribution pipe 1 with one end closed, and the other end of the gas distribution pipe 1 connected to an air pump 3 via a gas delivery pipe 2. Multiple flow control units 4 are installed along the length of the gas distribution pipe 1. Each flow control unit 4 includes a body 41 with multiple first channels 42. The first end of each first channel 42 extends to the top of the body 41, and the second end of each first channel 42 penetrates the side wall of the inner cavity 43 of the body 41. An elastic unit 44 is fixedly installed at the top of the inner cavity 43. Below the elastic unit 44, a slider 45 is slidably installed within the inner cavity 43. The slider 45 is a cylindrical structure with a cover plate at the top, and multiple components on the side wall of the slider 45 cooperate with the first channels 42. The working air guide groove 46 has a second channel 47 and a third channel 48 at the top and bottom of the body 41, respectively. The second channel 47 is connected to the longitudinal channel 44c on the elastic unit 44, and the inner cavity 43 is connected to the air distribution pipe 1 through the third channel 48. When the lower end of the slider 45 moves downward to abut against the bottom end face 43a of the inner cavity 43, the first channel 42 is isolated from the air guide groove 46. When the upper end of the slider 45 moves upward to abut against the lower end face of the elastic unit 44, the first channel 42 is connected to the air guide groove 46. As the slider 45 continues to move upward, the elastic unit 45 is compressed, and the effective connection area between the first channel 42 and the air guide groove 46 gradually decreases.

[0019] In the prior art, during the process of gas passing through the porous gas distribution pipe 1, see Figure 9 Because the gas flows out through the outlet 1a, some gas molecules are lost, resulting in a gradual decrease in the number of gas molecules passing through each pore. Since the gas is inside a long straight conduit and there are no external forces acting upon it, it can be approximated as an ideal gas, based on the ideal gas law. It can be concluded that under isothermal conditions, when the volume of the gas distribution tube... When kept constant, the number of gas molecules The reduction will directly lead to pressure The number density of molecules per unit volume decreases as the gas passes through each pore sequentially, resulting in a stepwise decrease in pressure within the gas distribution pipe from near to far. This is due to the pressure inside the device... The pressure decreases gradually along the ventilation direction, while the entire device is on the same plane and the external environmental pressure is constant, resulting in pressure differences across each pore. It also gradually decreases with increasing distance. Since the entire device is underwater, it can be considered as adiabatic flow, satisfying conditions such as low velocity and small pressure difference, making the small orifice flow formula applicable. (The remaining text appears to be incomplete and requires further context.) ) and gaseous physical properties (density) Flow coefficient Under the condition of keeping constant flow, according to the orifice flow formula Gas volume flow rate With pressure difference The square root is directly proportional. Therefore, as the distance from the vent increases, the pressure difference increases. The continuous decrease leads to a decrease in gas flow rate through each pore. It exhibits a gradual attenuation trend. This makes the bubble curtain unable to be uniform, continuous, and stable, significantly reducing its effect in weakening the shock wave.

[0020] The device of this application includes an air distribution pipe 1 with one end closed, and the other end of the air distribution pipe 1 connected to an air pump 3 via an air delivery pipe 2. Multiple flow control units 4 are installed on the air distribution pipe 1 along its length. During operation, the air distribution pipe 1 is first placed at the bottom of the water. When the air pump 3 is not started, a portion of the water flows from the second channel 47 through the longitudinal channel 44d on the elastic unit 44 into the inner cavity 43 of the body 41, and another portion of the water flows from the first channel 42 into the inner cavity 43 of the body 41. Under the action of its own weight and water pressure, the lower end of the slider 45 moves downwards until it abuts against the bottom end face 43a of the inner cavity 43. Figure 2 The air guide groove 46 is sealed by the side wall of the inner cavity 43 of the main body 41, thereby isolating the first channel 42 from the air guide groove 46 and preventing water from entering the inner cavity 45a of the slider 45 from the air guide groove 46, thus preventing water from flowing back into the air distribution pipe 1. When the air pump 3 starts to supply air, the gas flows into the inner cavity 45a of the slider 45 through the air supply pipe 2, the air distribution pipe 1, and the third channel 48. The air pressure pushes the slider 45 to slide upward, and then the first channel 42 connects with the air guide groove 46 until the top of the slider 45 abuts against the lower end face of the elastic unit 44. The effective communication area between the second end opening 42c of the first channel 42 and the air guide groove 46 is at its maximum value. Figure 3 Water is discharged from the inner cavity 43 and the first channel 42 of the body 41. When the air inlet pressure of the third channel 48 increases further, the elastic unit 44 is deformed under pressure, and the effective communication area between the second end opening 42c of the first channel 42 and the air guide groove 46 gradually decreases. This mechanism realizes the dynamic adjustment of the cross-sectional area of ​​the fluid channel based on pressure feedback. This application installs multiple flow control units 4 at different length positions of the air distribution pipe 1, so that the gas pressure at different positions acts on the corresponding elastic unit 44, so that a fluid channel cross-section based on pressure feedback is formed between the second end opening 42c of the first channel 42 and the air guide groove 46, effectively compensating for the flow deviation caused by pressure fluctuations at different positions on the air distribution pipe 1, so that the gas flow rate discharged by each flow control unit 4 is increased. The flow rate is approximately constant, thus achieving balanced control of the bubble curtain device and avoiding the problem of sharp reduction in the exhaust flow rate at the far end caused by the pressure decreasing along the air distribution pipe in the existing technology.

[0021] As one implementation method, in this embodiment, see... Figure 2 , Figure 3 The elastic unit 44 is a rubber pad with a central hole.

[0022] As one implementation method, in this embodiment, see... Figure 6 The elastic unit 44 includes a spring 44a, one end of which is connected to the body 41, and the other end of which is connected to the pressure plate 44b. The pressure plate 44b is provided with a through hole 44c that communicates with the second channel 47.

[0023] In one implementation, in this embodiment, the flow control unit 4 is connected to the air distribution pipe 1 by welding or threaded connection.

[0024] As one implementation method, in this embodiment, see... Figure 2-7 The slider 45 is a cylindrical structure adapted to the inner cavity 43. An annular groove 49 is provided on the side wall of the inner cavity 43 opposite to the entrance of the first channel 42. The annular groove is provided to avoid the problem of reduced effective communication area caused by the misalignment of the second end opening 42c of the first channel 42 and the air guide groove 46 in the circumferential direction.

[0025] In one embodiment, the slider 45 is a polygonal prism structure adapted to the inner cavity 43, see [link to relevant documentation]. Figure 8 During operation, the slider 45 can only move up and down and cannot rotate, thus preventing the second end opening 42c of the first channel 42 from being misaligned with the air guide groove 46 in the horizontal direction.

[0026] As one implementation method, in this embodiment, see... Figure 2-4 The first channel 42 includes an axial hole 42a perpendicular to the upper end face of the body 41 and a radial hole 42b communicating with the axial hole 42a. The radial hole 42b communicates with the inner cavity 43.

[0027] As one implementation method, in this embodiment, see... Figure 2 , Figure 3 A sealing element 5 is provided between the slider 45 and the body 41. The sealing element 5 is located below the radial hole 42b, which increases the airtightness between the slider 45 and the body 41 and improves the anti-backflow performance.

[0028] A working method for a bubble curtain device based on gas pressure feedback: During operation, first place the air distribution pipe 1 at the bottom of the water; When the air pump 3 is not supplying air, a portion of the water flows from the second channel 47 through the longitudinal channel 44d on the elastic unit 44 into the inner cavity 43 of the body 41, and another portion of the water flows from the first channel 42 into the inner cavity 43 of the body 41. Under the action of its own gravity and water pressure, the lower end of the slider 45 moves downward to abut against the bottom end face 43a of the inner cavity 43. The air guide groove 46 is sealed by the side wall of the inner cavity 43 of the body 41. Figure 2 This isolates the first channel 42 from the air guide groove 46, preventing water from entering the inner chamber 45a of the slider 45 from the air guide groove 46, and avoiding water backflow into the air distribution pipe 1.

[0029] When the air pump 3 starts supplying air, the gas flows into the inner chamber 45a of the slider 45 through the air supply pipe 2, the air distribution pipe 1, and the third channel 48. The air pressure pushes the slider 45 upward, and then the first channel 42 connects with the air guide groove 46 until the top of the slider 45 abuts against the lower end face of the elastic unit 44. The second end opening 42c of the first channel 42 remains connected to the air guide groove 46, and the water in the inner cavity 43 of the body 41 and the first channel 42 is discharged. When the air intake pressure of the third channel 48 further increases, the elastic unit 44 is deformed under pressure, and the effective communication area between the second end opening 42c of the first channel 42 and the air guide groove 46 gradually decreases.

Claims

1. A bubble curtain device based on gas pressure feedback, characterized in that: It includes a gas distribution pipe with a closed structure at one end, and the other end of the gas distribution pipe is connected to a gas pump through a gas delivery pipe. Multiple flow control units are installed on the gas distribution pipe along its length extension direction. The flow control unit includes a body with multiple first channels. The first end of each first channel extends to the top of the body, and the second end of each first channel penetrates the inner wall of the body. An elastic unit is fixedly installed at the top of the inner cavity. Below the elastic unit is a slider that is slidably installed in the inner cavity. The slider is a cylindrical structure with a cover plate at the top. The side wall of the slider has multiple air guide grooves that cooperate with the first channels. The top and bottom of the body have second and third channels, respectively. The second channel communicates with a longitudinal channel on the elastic unit, and the inner cavity communicates with the air distribution pipe through the third channel. When the lower end of the slider moves downward to abut against the bottom end face of the inner cavity, the first channel is isolated from the air guide groove. When the upper end of the slider moves upward and abuts against the lower end of the elastic unit, the first channel and the air guide groove are in a connected state; and as the slider continues to move upward, the elastic unit is compressed, and the effective connection area between the first channel and the air guide groove gradually shrinks.

2. The bubble curtain device based on gas pressure feedback according to claim 1, characterized in that: The elastic unit is a rubber pad with a central hole.

3. The bubble curtain device based on gas pressure feedback according to claim 1, characterized in that: The elastic unit includes a spring, one end of which is connected to the body and the other end of which is connected to a pressure plate. The pressure plate has a through hole that communicates with the second channel.

4. The bubble curtain device based on gas pressure feedback according to claim 1, characterized in that: The flow control unit is connected to the air distribution pipe by welding or threaded connection.

5. The bubble curtain device based on gas pressure feedback according to claim 1, characterized in that: The slider is a cylindrical structure adapted to the inner cavity, and an annular groove is provided on the side wall of the inner cavity directly opposite the entrance of the first channel.

6. The bubble curtain device based on gas pressure feedback according to claim 1, characterized in that: The slider is a polygonal prism structure adapted to the inner cavity.

7. The bubble curtain device based on gas pressure feedback according to claim 1, characterized in that: The first channel includes an axial hole perpendicular to the upper end face of the body and a radial hole communicating with the axial hole, the radial hole communicating with the inner cavity.

8. The bubble curtain device based on gas pressure feedback according to claim 7, characterized in that: A seal is provided between the slider and the body, and the seal is located below the radial hole.

9. The working method of the bubble curtain device based on gas pressure feedback according to any one of claims 1-6, characterized in that: When working, first place the air distribution pipe at the bottom of the water; When the air pump is not supplying air, water flows from the second channel into the inner cavity of the body through the longitudinal channel on the elastic unit. Under the action of its own weight and water pressure, the slider keeps its lower end face in contact with the bottom end face of the inner cavity. The air guide groove is sealed by the inner cavity side wall of the body, thereby isolating the first channel from the air guide groove, preventing water from entering the inner cavity of the slider from the air guide groove, and avoiding water backflow into the air distribution pipe. When the air pump starts supplying air, the gas flows into the inner chamber of the slider through the air supply pipe, air distribution pipe, and third channel. The air pressure pushes the slider to slide upward. Then the first channel connects with the air guide groove until the top of the slider abuts against the lower end face of the elastic unit. The second end opening of the first channel remains connected to the air guide groove. When the air intake pressure of the third channel increases further, the elastic unit is deformed by pressure, and the effective connection area between the second end opening of the first channel and the air guide groove gradually decreases.

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