Metal wire electric explosion shock wave collecting device

Abstract

The utility model discloses a metal wire electric explosion shock wave collecting device which comprises a shock wave generating system and a shock wave collecting system. One end of a direct-current power supply in the shock wave generation system is connected with an energy storage capacitor through a wire; the energy storage capacitor is connected to a discharge electrode through a coaxial cable; an electrode at the other end of the direct-current power supply is connected with a grounding resistor through a wire; the grounding resistor is connected to a discharge electrode through another coaxial cable; the lower ends of the discharge electrodes are connected by metal wires; the dielectric medium is used for filling a drill hole of a to-be-tested impact object for immersing the lower end of the discharge electrode; the shock wave acquisition system comprises a strain gauge and a signal acquisition device, the strain gauge is used for being pasted on the surface of a to-be-measured impact object in a 0-90-degree mode, and the pasting position and the metal wire position are located at the same horizontal height. The device can realize high-precision measurement of electric explosion shock waves, is adaptive to various dielectric media, can realize comprehensive acquisition of stress data of the shock waves in different directions, and is simple to operate, accurate in result and high in adaptability.

Description

Technical Field

[0001] The utility model relates to the technical field of metal wire point explosion shock wave energy measurement, in particular to a metal wire electric explosion shock wave acquisition device. Background Art

[0002] Wire electro-explosion technology involves injecting high-voltage pulsed current within a specific parameter range into a metal wire. Due to the Ohmic heating mechanism, Joule heating is generated, causing the wire to undergo a series of phase transitions, from solid to liquid, gaseous, and plasma states. This in turn generates high-temperature, high-pressure plasma and a powerful shock wave generated by the compression of the surrounding liquid medium. Wire electro-explosion not only plays a key role in fundamental physics research, such as in plasma physics and high-energy-density physics, but also demonstrates great potential in engineering applications, including the preparation of nanopowders, electro-forming of metal liquids, oilfield de-blocking, wastewater treatment, underwater sound generation, and green demolition of urban buildings.

[0003] Shock wave intensity is a key indicator of the effectiveness of wire electric explosions, and its controllability is crucial for experimental repeatability and application predictability. The ability to precisely control and measure shock wave energy allows for more sophisticated manipulation of material state transitions, deeper investigation of the physical and chemical reactions between the electric explosion and the surrounding liquid medium, and further improvements in shock wave energy conversion efficiency and reduction of energy loss. For example, in mining projects, controlling the shock wave intensity generated by electric explosions can optimize the rock crushing process, improving resource extraction efficiency while reducing energy waste.

[0004] According to the different physical quantities measured, shock wave measurement methods are divided into indirect method and direct method.

[0005] One is the indirect method. Indirect measurement methods mainly use optical technology, such as the shadow method, the Schlieren method, and the laser interferometry method. The shadow method and the Schlieren method are based on the non-interference laser detection polarization measurement technology of the Faraday effect and the Kerr effect. The shock wave boundary velocity is obtained by the time of flight (TOF) method, and then the shock wave peak pressure is calculated with the help of the water state equation (EOS). The laser interferometry method calculates the shock wave pressure by obtaining the spatial distribution of the density of the water body under the action of the metal wire electric explosion. These methods can measure the shock wave near the explosion source, but cannot measure the pressure characteristics that change with time, so the shock wave energy cannot be calculated.

[0006] The other method is direct. Direct measurement of shock wave pressure relies primarily on various pressure sensors, using various measurement principles, including piezoresistive, piezoelectric, capacitive, and inductive. Among these, the PCB138 series piezoelectric pressure sensors and PCB113B series acceleration-type pressure sensors from PCB Piezotronics (USA), as well as the PVDF (polyvinylidene fluoride)-based Müller-plate Needle Hydrophone pressure sensor, have been widely used to collect shock wave pressure curves generated by electrical explosions. During measurement, these sensors must be placed in a liquid medium. However, the electromagnetic field generated during an electrical explosion can cause distortion and noise in the pressure signal, affecting the accuracy of the experimental data. Furthermore, the positioning of the pressure sensor is crucial: sensors located too close to the explosion source may be damaged by the high-intensity shock wave, while sensors located further away from the explosion source may be unable to collect effective data due to significant attenuation of the shock wave signal. Utility Model Content

[0007] The purpose of the utility model is to address the deficiencies in the prior art and provide a metal wire electric explosion shock wave acquisition device with high measurement accuracy, applicable to a variety of dielectrics, and capable of acquiring stress data of shock waves in different directions.

[0008] The technical solution of this utility model is described in detail as follows:

[0009] A metal wire electric explosion shock wave collection device, comprising a shock wave generating system and a shock wave collection system;

[0010] The shock wave generating system comprises a DC power supply (1), an energy storage capacitor (2), a grounding resistor (3), a discharge ball (4), a coaxial cable (7), a discharge electrode (8) and a dielectric (12); wherein, an electrode at one end of the DC power supply (1) is connected to the energy storage capacitor (2) via a wire, and the energy storage capacitor (2) is connected to the discharge electrode (8) via a coaxial cable (7); an electrode at the other end of the DC power supply (1) is connected to the grounding resistor (3) via a wire, and the grounding resistor (3) is connected to the discharge electrode (8) via another coaxial cable (7); the lower end of the discharge electrode (8) is connected via a metal wire (13); and the dielectric (12) is used to be filled in a borehole of a to-be-tested impact object for the lower end of the discharge electrode (8) to be immersed;

[0011] The shock wave acquisition system comprises a strain gauge (10) and a signal acquisition device (14), wherein the strain gauge (10) is connected to the signal acquisition device (14) via a data transmission line, and the strain gauge (10) is used to be attached to the surface of the impact object to be measured in a manner of 0°-90°, and the attachment position is at the same horizontal height as the position of the metal wire (13) at the lower end of the discharge electrode (8).

[0012] Optionally or preferably, the shock wave generating system further comprises a current coil (5), which is mounted on a coaxial cable (7) between the discharge ball (4) and the discharge electrode (8) for measuring loop current changes.

[0013] Optionally or preferably, the shock wave generating system further comprises a voltage probe (6), which is installed between the positive and negative poles of the discharge electrode (8) and is used to measure the voltage change at both ends of the discharge electrode (8).

[0014] Optionally or preferably, the energy storage capacitor (2) matches the material of the impact object to be measured.

[0015] Optionally or preferably, the discharge electrode (8) comprises a positive electrode rod, a negative electrode rod, a metal wire (13) and a sealed end cap, the positive electrode rod and the negative electrode rod pass through the sealed end cap, and the lower ends of the positive electrode rod and the negative electrode rod are connected by the metal wire (13).

[0016] Optionally or preferably, the dielectric (12) includes one of a liquid dielectric, a solid dielectric, and a gas-liquid mixed dielectric.

[0017] Optionally or preferably, the size of the metal wire (13) matches the energy storage capacitor (2). The size includes a cross-sectional area (S) and a length (l), and the calculation formula is as follows:

[0018]

[0019] Wherein, S is the cross-sectional area of ​​the metal wire (13), l is the length of the metal wire (13), f0 is the circuit oscillation frequency, C is the energy storage capacitor, and U0 is the system charging voltage.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The utility model is based on the strain gauge measurement principle and converts the shock wave pressure signal into the strain signal generated by the impact object to be measured. It not only improves the measurement accuracy, but also effectively resists the interference of the external electromagnetic field, reduces the influence of electromagnetic interference on the measurement signal, and realizes high-precision measurement of electric explosion shock waves.

[0022] In addition, compared with the defect that traditional pressure sensors can only measure stress along a single direction and cannot realize multi-dimensional quantities, the strain gauges of the utility model can have multiple arrangements at any angle within 0°-90°. This arrangement can realize the comprehensive collection of stress data of shock waves in different directions, and provide richer information for in-depth analysis of the propagation mechanism and effect of electric explosion shock waves.

[0023] Traditional measurement platforms are typically limited to using a single type of dielectric. The design of this device allows for simultaneous use with multiple different dielectrics. This flexibility reduces experimental errors that may be introduced by limitations of the platform equipment, further improving the applicability and accuracy of the experiment.

[0024] In summary, the utility model of the metal wire electric explosion shock wave acquisition device is economical and can greatly reduce the measurement cost; it is simple to operate and easy to install; it has strong adaptability and can be used in various venues; it has strong scalability and can subsequently add factors such as temperature and vibration for research. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of the metal wire electric explosion shock wave collection device in Example 1.

[0026] Figure 2 Schematic diagram of the 0°-45°-90° strain gauge arrangement.

[0027] Figure 3 This is the X-direction linear strain waveform diagram measured by the metal wire electric explosion shock wave acquisition device in Example 2.

[0028] Figure 4 This is the U-direction linear strain waveform diagram measured by the metal wire electric explosion shock wave acquisition device in Example 2.

[0029] Figure 5 This is the Y-direction linear strain waveform diagram measured by the metal wire electric explosion shock wave acquisition device in Example 2.

[0030] Figure 6 This is the principal strain waveform diagram measured by the metal wire electric explosion shock wave acquisition device in Example 2. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the present application, the present application will be clearly and completely described below in conjunction with the embodiments and drawings. Obviously, the embodiments described are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of this application. The instruments and parts used in the embodiments are all sourced from commercial channels unless otherwise specified.

[0032] Example 1 Metal Wire Electric Explosion Shock Wave Collection Device

[0033] Please refer to Figure 1 , a metal wire electric explosion shock wave collection device, including a shock wave generating system and a shock wave collection system.

[0034] The shock wave generating system includes a DC power supply 1, an energy storage capacitor 2, a grounding resistor 3, a discharge ball 4, a current coil 5, a voltage probe 6, a coaxial cable 7, a discharge electrode 8, and a dielectric 12. The discharge electrode 8 includes a positive electrode rod, a negative electrode rod, a metal wire 13, and a sealed end cap. The positive electrode rod and the negative electrode rod pass through the sealed end cap, and the lower ends of the positive electrode rod and the negative electrode rod are connected by the metal wire 13.

[0035] The electrode (positive pole) at one end of the DC power supply 1 is connected to the energy storage capacitor 2 through a wire, and the energy storage capacitor 2 is connected to the positive electrode rod of the discharge electrode 8 through a coaxial cable 7; the electrode (negative pole) at the other end of the DC power supply 1 is connected to the grounding resistor 3 through a wire, and the grounding resistor 3 is connected to the negative electrode rod of the discharge electrode 8 through another coaxial cable 7. The grounding resistor 3 also has two terminals, one terminal is used for grounding, and the other terminal is connected to the conductive line between the energy storage capacitor 2 and the discharge electrode 8. The dielectric 12 is used to fill the drilled hole of the impact object 11 to be tested for immersion of the lower end of the discharge electrode 8. The current coil 5 is installed on the coaxial cable 7 between the discharge ball 4 and the discharge electrode 8 to measure the change in loop current. The voltage probe 6 is installed between the positive and negative poles of the discharge electrode 8 to measure the voltage change at both ends of the discharge electrode 8.

[0036] The shock wave collection system includes a strain gauge 10 connected to a collection device 14. The strain gauge 10 is used to be pasted on the surface of the impact object 11 to be measured at any one or more angles of 0°-90°, and the pasting position is at the same horizontal height as the position of the metal wire 13 at the lower end of the discharge electrode 8.

[0037] A DC power supply 1 supplies energy to the energy storage capacitor 2. When the set voltage is reached, the discharge ball 4 is triggered to break down and discharge, completing a single wire 13 electric explosion experiment. A grounding resistor 3 dissipates residual voltage in the circuit, ensuring operator safety. A current coil 5 and a voltage probe 6 measure the changes in the loop current and the voltage across the discharge electrode, respectively, to calculate the energy deposition power and energy conversion efficiency during the wire explosion process.

[0038] The impact object 11 to be tested can be made of a suitable material, such as granite, sandstone, concrete, etc., based on the initial discharge energy storage. If the energy storage does not match the rock sample material, it is easy to cause problems such as the inability to collect effective impact waveforms or the collected waveforms being distorted. A borehole 9 is opened on the free surface of the impact object 11 to be tested. The depth and diameter of the borehole 9 should match the size of the discharge electrode 8. Specifically, the depth of the borehole 9 should exceed 20% of the length of the positive and negative electrode rods extending into the borehole 9, and the aperture of the borehole 9 should be less than 80% of the diameter of the sealing end cap of the discharge electrode 8 to achieve internal sealing of the borehole 9, thereby preventing the dielectric 12 from being flushed out of the borehole 9 by the electric explosion shock wave, thereby reducing shock wave energy loss.

[0039] The dielectric 12 filled in the borehole 9 can be any material required for the experiment, including liquid materials, solid materials, gas-liquid mixtures, or other material mixtures. Liquid materials include tap water, potassium chloride solution, sodium chloride solution, and aluminum powder suspension; solid materials include nitromethane, copper oxide powder, and aluminum powder; and gas-liquid mixtures include liquid nitrogen and liquid carbon dioxide.

[0040] The metal wire 13 should be selected with a size and material that matches the initial energy storage according to the experimental requirements. If the metal wire 13 is too thin, it will overheat due to excessive resistance when current passes through it, resulting in premature breakage and failure to complete the predetermined energy transfer and conversion process. A thick metal wire 13 may not be fully converted into a plasma state during the explosion, thereby reducing the explosion effect. The appropriate size can be calculated according to formula (1).

[0041]

[0042] Where S is the cross-sectional area of ​​the metal wire in matching mode, l is the length of the metal wire in matching mode, f0 is the circuit oscillation frequency, C is the energy storage capacitor, and U0 is the system charging voltage.

[0043] The strain gauge 10 can be attached to the impact object 11 to be measured in different ways, but it needs to be at the same level as the metal wire 13 to reduce the loss of shock wave acquisition data.

[0044] The strain gauge 10 has low strength, so it should be measured with a multimeter before pasting. When its resistance is around 120Ω, it indicates that the strain gauge is not damaged.

[0045] During the process of attaching the strain gauge 10, the following steps must be followed: ① Smooth and clean the surface of the impact object 11 to be tested, ensuring that there is no dust, grease, or other impurities; ② Select a strain gauge 10 of the appropriate type and specification, and determine the sensitivity, size, and arrangement of the strain gauge 10. ③ Apply a thin layer of adhesive, such as epoxy resin, evenly on the back of the strain gauge 10. At the same time, pre-apply a thin layer of adhesive to the surface of the impact object 11 to increase adhesion; ④ Place the strain gauge 10 precisely at the predetermined position on the surface of the impact object 11 to be tested. Use appropriate tools, such as tweezers, to avoid direct contact between your fingers and the strain gauge 10. Finally, press the strain gauge 10 to ensure that it is in full contact with the surface of the impact object 11 to be tested. Avoid bubbles or wrinkles; ⑤ Follow the instructions for the adhesive and wait for sufficient time for the adhesive to completely cure.

[0046] The fully solidified strain gauge 10 is connected to the signal acquisition device 14 via a data transmission line. The signal acquisition device 14 is used to record the deformation caused by the electric explosion shock wave on the impact object, measure the strain waveform in different directions, and select the principal strain calculation formula for calculation according to the arrangement method.

[0047] This measurement method uses the strain gauge rosette method. When the direction of the principal stress is unknown, three strain gauges in different directions are pasted at the common intersection for synchronous measurement, and the principal stress value is calculated according to the existing formula.

[0048] There are two commonly used strain gauge rosette measurement methods, with strain gauge angles of 45° and 60° respectively. When measuring at 45°, it is easier to stick the strain gauge, so this method uses 45° measurement.

[0049] The following formula (2) is the calculation formula for the principal strain under the 0°-45°-90° arrangement.

[0050]

[0051] Where ε u , ε x , ε y Corresponding to the single direction line strain of u, x, y, ε max is the maximum principal strain at the measured point, ε min is the minimum principal strain at the measured point.

[0052] The principal strain waveform must also be multiplied by the elastic modulus corresponding to the impact object 11 to obtain the pressure-time curve P of a single electrohydraulic shock wave. sw The equivalent energy of a single electrohydraulic shock wave E can be calculated by formula (3): w , thereby evaluating the effect of different dielectrics on the energy enhancement of metal wire electric explosion.

[0053]

[0054] Where D is the horizontal distance from the strain gauge to the discharge channel, ρ is the density of the solid medium, and C S is the propagation speed of shock wave in solid medium, P sw is the calculated shock wave principal stress.

[0055] Example 2

[0056] The metal wire electric explosion shock wave acquisition device of Example 1 was used. In this experiment, the output voltage was set to 5kV, the energy storage capacitor was 500μF, the metal wire 13 was selected to be a copper wire with a diameter of 0.5mm and a length of 4cm. The dielectric 12 was selected to be 40mg / cm 3The impact object 11 to be tested was a concrete block made of gravel, cement, and sand in a ratio of 2.7:1:2. A hole 9 was drilled in the concrete block. Rock mechanics experiments determined the elastic modulus to be 26 GPa. After measuring the resistance of the strain gauge 10 with a multimeter, it was affixed to the outer surface of the impact object 11 as required. The device was then connected to a signal acquisition device 14 via a data cable. Before the electrical explosion experiment began, the equipment was calibrated and tested on a small scale to ensure proper functioning of the measurement system. The prepared dielectric 12, discharge electrode 8, and the metal wire 13 connected to its end were then placed sequentially into the drilled hole 9. After sealing, the electrical explosion experiment was ready to begin.

[0057] After the electric explosion experiment, the signal acquisition device 14 obtains the strain waveforms in different directions as follows Figure 3-6 The processed principal strain waveform data was applied to formula (3) for calculation. The results showed that under the condition of using potassium chloride solution as the dielectric, a single electric explosion experiment could generate a shock wave energy of 3.16 kJ, which accounts for approximately 50.5% of the initial discharge energy storage. Based on this, by comparing and analyzing the strain waveforms obtained under different dielectric environments, we can further explore the specific effects of various dielectrics on the electric explosion process and its shock wave generation mechanism.

[0058] This document uses specific examples to illustrate the inventive concept in detail. The above examples are only intended to help you understand the core concept of the present invention. It should be noted that any obvious modifications, equivalent substitutions, or other improvements made by a person skilled in the art without departing from the inventive concept should be included within the scope of protection of the present invention.

Claims

1. A metal wire electric explosion shock wave collection device, characterized in that: Including shock wave generating system and shock wave collecting system; The shock wave generating system comprises a DC power supply (1), an energy storage capacitor (2), a grounding resistor (3), a discharge ball (4), a coaxial cable (7), a discharge electrode (8) and a dielectric (12); wherein, an electrode at one end of the DC power supply (1) is connected to the energy storage capacitor (2) via a wire, and the energy storage capacitor (2) is connected to the discharge electrode (8) via a coaxial cable (7); an electrode at the other end of the DC power supply (1) is connected to the grounding resistor (3) via a wire, and the grounding resistor (3) is connected to the discharge electrode (8) via another coaxial cable (7); the lower end of the discharge electrode (8) is connected via a metal wire (13); and the dielectric (12) is used to be filled in a borehole of a to-be-tested impact object for the lower end of the discharge electrode (8) to be immersed; The shock wave acquisition system comprises a strain gauge (10) and a signal acquisition device (14), wherein the strain gauge (10) is connected to the signal acquisition device (14) via a data transmission line, and the strain gauge (10) is used to be attached to the surface of the impact object to be measured in a manner of 0°-90°, and the attachment position is at the same horizontal height as the position of the metal wire (13) at the lower end of the discharge electrode (8).

2. The device according to claim 1, characterized in that The shock wave generating system further comprises a current coil (5), which is mounted on a coaxial cable (7) between the discharge ball (4) and the discharge electrode (8) and is used to measure loop current changes.

3. The device according to claim 1, characterized in that The shock wave generating system further comprises a voltage probe (6), which is installed between the positive and negative poles of the discharge electrode (8) and is used to measure voltage changes at both ends of the discharge electrode (8).

4. The device according to claim 1, characterized in that The energy storage capacitor (2) matches the material of the impact object to be tested.

5. The device according to claim 1, characterized in that The discharge electrode (8) comprises a positive electrode rod, a negative electrode rod, a metal wire (13) and a sealed end cover. The positive electrode rod and the negative electrode rod pass through the sealed end cover, and the lower ends of the positive electrode rod and the negative electrode rod are connected by the metal wire (13).

6. The device according to claim 1, characterized in that The dielectric (12) comprises one of a liquid dielectric, a solid dielectric, and a gas-liquid mixed dielectric.

7. The device according to claim 1, characterized in that The size of the metal wire (13) matches that of the energy storage capacitor (2).

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