CN115096538B - Pulse discharge ignition system for coaxial cylindrical deflagration driving device - Google Patents

Abstract

The invention discloses a pulse discharge ignition system for a coaxial cylinder deflagration driving device, comprising a delay pulse generator, an ignition circuit relay, an unloading circuit relay, an ignition wire, a high-voltage capacitor and a power frequency withstand voltage test device; a high-voltage capacitor The positive electrode, the ignition circuit relay, the ignition wire and the negative electrode of the high-voltage capacitor constitute the ignition circuit, the positive electrode of the high-voltage capacitor, the unloading circuit relay and the negative electrode of the high-voltage capacitor constitute the unloading circuit, and the ignition circuit and the unloading circuit are connected in parallel; the ignition circuit relay and the unloading circuit relay are respectively It is electrically connected with the delay pulse generator; the power frequency withstand voltage test device is electrically connected with the high voltage capacitor. The invention can realize the ignition mode of the deflagration driving technology, that is, the high-voltage discharge whose duration is on the order of milliseconds. Time drops to a very low value, so that the voltage across the ignition wire is not enough to cause breakdown.

Description

Pulse Discharge Ignition System for Coaxial Cylindrical Deflagration Driver

technical field

The present invention relates to the technical field of high-temperature high-speed gas dynamics, high-speed aircraft and other experimental research, and more specifically, relates to a pulse discharge ignition system for a coaxial cylindrical deflagration drive device.

Background technique

The shock tube/wind tunnel is a kind of experimental equipment widely used in the fields of high-temperature and high-speed aerodynamics, high-speed aircraft, etc. The basic principle is: the high-pressure driving gas compresses the low-pressure test gas through the shock wave to make it reach the required test state. As shown in Figure 1, a typical shock tube/wind tunnel includes a driving section 1', a driven section 2', a nozzle 3' and a test section 4'; before the test, the driving section 1' and the driven section 2' are The diaphragm 5' is separated, and the driving section 1' is filled with high-pressure driving gas, and the driven section 2' is filled with low-pressure test gas; during the test, the diaphragm 5' ruptures, and the high-pressure gas expands and enters the driven section 2'. At the same time, a fast-moving shock wave is generated in the driven section 2'; if the gas after the shock wave is directly used to carry out the test, the equipment operates in the shock tube mode; if the gas accelerated by the nozzle 3' is used The test gas is used to carry out the test, and the equipment operates in the shock tunnel mode.

The total temperature and total pressure range of the test gas are the main indicators to measure the capability of the equipment, both of which depend on the driving ability of the high-pressure driving gas. Normal temperature and high pressure gas can no longer meet the increasingly demanding test requirements. Therefore, three high-performance drive technologies have been developed at home and abroad: piston drive, heated light gas drive and detonation drive. Among them, the detonation drive technology has the characteristics of low cost, simple structure and relatively safe, and is currently the mainstream technology in China.

The detonation-driven shock tube was first proposed by Bird in 1957. Mr. Yu Hongru from the Institute of Mechanics, Chinese Academy of Sciences built a 13.3m long detonation-driven shock tube in 1981 and put it into use in 1983. The Institute of Mechanics of the Chinese Academy of Sciences developed the JF-10 detonation-driven high-enthalpy shock tunnel in 1994 [see Yu Hongru, Zhao Wei, Yuan Shengxue, Performance of Hydrogen-Oxygen Detonation-Driven Shock Tunnel - Aerodynamic Test and Measurement Control, 1993, 7(3):38-42]. With the help of Mr. Yu Hongru, Gronig and others built a high-enthalpy shock tunnel (TH2-D) driven by reverse detonation at RWTH Aachen University in Germany in 1993. In 1994, NASA modified the original free-piston-driven design, and built a forward detonation-driven high-enthalpy shock tunnel (HYPULSE) in GASL. The wind tunnel can work in both reflection shock tunnel mode and expansion tube Mode [see ChueRSM, Tsai C-Y, Bakos RJ, Erdos JI, Rogers RC (2002) NASA's HYPULSE Facility at GASL-A Dual Mode, Dual Driver Reflected-Shock/Expansion Tunnel. In: LuF, Marren D (eds), Advanced Hypersonic Test Facilities, Progress in Astronautics and Aeronautics, Vol.198, AIAA, Chapter 3, pp29-71].

The detonation drive needs to form a detonation wave propagating in the axial direction in the driving section, and the uneven flow field behind the detonation wave causes the following problems in this drive technology: First, the gas mixing ratio range that can be detonated is lower than that of the gas that can be detonated. The range of the test gas is much narrower, and the range of temperature and sound velocity of the driving gas is correspondingly narrower, thus limiting the total temperature range of the test gas that the detonation drive can provide; second, the effective driving pressure provided by the detonation drive does not exceed the pressure limit of the equipment 40% limits the total pressure range of the test gas.

Due to the above-mentioned problems in the detonation drive, the above-mentioned problems need to be overcome, and the coaxial cylindrical deflagration drive technology needs to be introduced. Arrange an ignition wire along the center line of the driving section axis, and use the discharge system to supply power to the ignition wire. Among them, the required high-voltage pulse power supply uses a high-voltage capacitor as an energy storage element, and the time required for the charge in the high-voltage capacitor to be completely released The duration (on the order of 10 ms) is long, and the combustion products contain a large amount of ions and water, which is very prone to breakdown. In order to ensure the safety of equipment and personnel, it is necessary to control the duration of power-on to the order of milliseconds.

Existing document 1 (CN113483982A) discloses a biological shock tube experimental system for simulating different scenarios, including a gas distribution system, an ignition system, a shock wave pipeline system and a data acquisition system, wherein the ignition system includes a trigger, a divider switch , high-voltage capacitor group, high-voltage power supply and igniter. The drive technology does not involve the ignition wire, so there is no solution for the ignition circuit and the unloading circuit.

Existing document 2 (CN102407947A) discloses a shock tunnel detonation double drive device, comprising: a shock tunnel, the shock tunnel has a detonation driving section, and one end of the detonation driving section is provided with a detonation section, The other end is provided with a driven section; a first diaphragm is arranged between the detonation unloading section and the detonation driving section, and a second diaphragm is arranged between the driven section and the detonation driving section; A section of the detonation drive section close to the detonation section is provided with a forward detonation drive ignition device, and a section of the detonation drive section close to the driven section is provided with a reverse detonation drive ignition device; A controllable delay trigger device is connected between the forward detonation driven ignition device and the reverse detonation driven ignition device, and the method is as follows: 1) near the detonation unloading section of the shock wave wind tunnel detonation drive section A positive detonation ignition device is arranged at one end, and a reverse detonation driving ignition device is arranged at the end of the detonation driving section close to the driven section; 2) ignition is performed by the forward detonation ignition device to form a forward driving detonation wave; 3) After the forward detonation wave propagates along the detonation driving section for a predetermined time, the ignition device is driven by the reverse detonation to ignite to form a reverse drive detonation wave; 4) The reverse drive detonation wave will be set at the driven The diaphragm between the detonation driving section and the detonation driving section is torn, and the forward detonation wave intersects with the reverse detonation wave to form a moving shock wave, which enters the driven section to conduct a Compression, the above scheme is only applicable to the detonation drive technology, since the detonation drive technology does not involve the ignition wire, so there is no scheme for the ignition circuit and the unloading circuit.

In order to overcome the above-mentioned problems of detonation drive, the present invention proposes a kind of pulse discharge ignition system for coaxial cylindrical deflagration drive device, and this pulse discharge ignition system for coaxial cylindrical deflagration drive device is a person skilled in the art Not easy to think of.

Contents of the invention

In view of this, the present invention provides a pulse discharge ignition system for a coaxial cylindrical deflagration driving device, including a delay pulse generator, an ignition circuit relay, an unloading circuit relay, an ignition wire, a high voltage capacitor and a power frequency resistance Pressure test device;

The positive pole of the high-voltage capacitor, the ignition circuit relay, the ignition wire and the negative pole of the high-voltage capacitor constitute an ignition circuit, and the positive pole of the high-voltage capacitor, the relay of the unloading circuit and the negative pole of the high-voltage capacitor constitute an unloading circuit. The ignition circuit is connected in parallel with the unloading circuit, and the high voltage capacitor is used to store high voltage and discharge to the ignition wire;

The ignition circuit relay and the unloading circuit relay are respectively electrically connected to the delay pulse generator;

The power frequency withstand voltage test device is electrically connected to the high voltage capacitor, and the power frequency withstand voltage test device is used to charge the high voltage capacitor.

Optionally, the ignition wire is made of metal.

Optionally, the metal material is any one of copper, silver, nickel-chromium, tungsten and alloys.

Optionally, the delayed pulse generator adopts DG535 four-channel digital delayed pulse generator.

Optionally, both the ignition circuit relay and the unloading circuit relay are JPK-58A gas-filled high-voltage relays.

Optionally, the high-voltage capacitor is a DAWNCAPDTH-20000 high-voltage pulse capacitor.

Compared with the prior art, the pulse discharge ignition system for the coaxial cylindrical deflagration driving device provided by the present invention at least achieves the following beneficial effects:

In this embodiment, an ignition circuit is formed by connecting an ignition circuit relay, the ignition wire and the high-voltage capacitor in series, and the high-voltage capacitor and the unloading circuit relay are connected in series to form an unloading circuit. The circuit relay and the unloading circuit relay are respectively electrically connected to the delay pulse generator, which can realize the ignition mode of the deflagration drive technology, that is, the high-voltage discharge with a duration of milliseconds. After a predetermined time, the unloading circuit is used to make the high-voltage capacitor The positive and negative poles of the ignition wire are short-circuited, so that the voltage of the high-voltage capacitor drops to a very low value in milliseconds, so that the voltage at both ends of the ignition wire is not enough to cause breakdown.

Of course, any product implementing the present invention does not necessarily need to achieve all the above-mentioned technical effects at the same time.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

Fig. 1 is a structural schematic diagram of a shock tube/wind tunnel provided in the prior art;

Fig. 2 is a schematic structural diagram of a pulse discharge ignition system for a coaxial cylindrical deflagration drive device provided by an embodiment of the present invention;

Fig. 3 is a schematic structural view of a coaxial cylindrical deflagration driving device for a shock tube/wind tunnel provided by an embodiment of the present invention;

Figure 4 is an enlarged view of the structure at B in Figure 3;

Fig. 5 is an enlarged view of the structure of the pulse discharge ignition system used for the coaxial cylindrical deflagration driving device in Fig. 3;

Fig. 6 is a logic block diagram of a pulse discharge ignition system for a coaxial cylindrical deflagration driving device provided by an embodiment of the present invention;

Fig. 7 is a schematic structural diagram of a shock tube/wind tunnel provided by an embodiment of the present invention.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and in no way taken as limiting the invention, its application or uses.

Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, techniques, methods and devices should be considered part of the description.

In all examples shown and discussed herein, any specific values should be construed as exemplary only, and not as limitations. Therefore, other instances of the exemplary embodiment may have different values.

It should be noted that like numerals and letters denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

Fig. 2 is a schematic structural diagram of a pulse discharge ignition system for a coaxial cylindrical deflagration driving device provided by an embodiment of the present invention; referring to Fig. 2, this embodiment provides a kind of pulse discharge ignition system for a coaxial cylindrical deflagration The pulse discharge ignition system of the driving device, including a delay pulse generator 100, an ignition circuit relay 720, an unloading circuit relay 730, an ignition wire 13, a high voltage capacitor 71 and a power frequency withstand voltage test device 200;

The positive pole of the high-voltage capacitor 71, the ignition circuit relay 720, the ignition wire 13 and the negative pole of the high-voltage capacitor 71 constitute an ignition circuit, the positive pole of the high-voltage capacitor 71, the unloading circuit relay 730 and the negative pole of the high-voltage capacitor 71 constitute an unloading circuit, and the ignition circuit and the unloading circuit are connected in parallel. The high-voltage capacitor 71 is used to store high-voltage electricity and discharge it to the ignition wire 13;

The ignition circuit relay 720 and the unloading circuit relay 730 are electrically connected with the delay pulse generator 100 respectively;

The power frequency withstand voltage test device 200 is electrically connected to the high voltage capacitor 71 , and the power frequency withstand voltage test device 200 is used to charge the high voltage capacitor 71 .

Specifically, the pulse discharge ignition system for a coaxial cylindrical deflagration drive device includes a delay pulse generator 100, an ignition circuit relay 720, an unloading circuit relay 730, an ignition wire 13, a high voltage capacitor 71 and a power frequency withstand voltage test The device 200 and the delayed pulse generator 100 can be the DG535 four-channel digital delayed pulse generator 100, which provides four independent delayed channels and two complete pulse outputs. Its delay resolution is as high as 5ps, and the jitter between channels is less than 50ps; the ignition circuit relay 720 and unloading circuit relay 730 can use JPK-58A gas-filled high-voltage relay, and the wiring method of JPK-58A gas-filled high-voltage relay is simple and replaceable Coils diversify product functions; high-voltage capacitor 71 can use DAWNCAPDTH-20000 high-voltage pulse capacitor, DAWNCAPDTH-20000 high-voltage pulse capacitor can generate 20000V high voltage, DAWNCAPDTH-20000 high-voltage pulse capacitor can withstand large current and high voltage; low loss, High stability; the ignition wire 13 can be any metal material in copper, silver, nickel-chromium, tungsten and alloy, as long as it can conduct electricity; certainly the above-mentioned delay pulse generator 100, ignition circuit relay 720, unloading circuit relay 730 , the models of the high voltage capacitor 71 and the power frequency withstand voltage test device 200 can also be adjusted appropriately according to the actual situation.

High-voltage capacitor 71 positive pole, ignition circuit relay 720, ignition wire 13 and high-voltage capacitor 71 negative pole constitute an ignition circuit, that is, ignition circuit relay 720, ignition wire 13 and high-voltage capacitor 71 are connected in series to form an ignition circuit; high-voltage capacitor 71 positive pole, unloading circuit relay 730 And the negative pole of the high-voltage capacitor 71 forms an unloading circuit, that is, the high-voltage capacitor 71 and the unloading circuit relay 730 are connected in series to form an unloading circuit, the ignition circuit and the unloading circuit are connected in parallel, and the high-voltage capacitor 71 is used to store high-voltage electricity and discharge to the ignition wire 13 ;

The ignition circuit relay 720 and the unloading circuit relay 730 are electrically connected with the delay pulse generator 100 respectively, and the two output signals of the delay pulse generator 100 control the opening and closing of the ignition circuit relay 720 and the unloading circuit relay 730 respectively;

The power frequency withstand voltage test device 200 is electrically connected to the high voltage capacitor 71. The power frequency withstand voltage test device 200 is used to charge the high voltage capacitor 71. The power frequency withstand voltage test device 200 is a commercial product and can be purchased in the market.

The specific principle is as follows: when the pulse discharge ignition system used for the coaxial cylindrical deflagration driving device is in operation, the high-voltage capacitor 71 is first charged to the voltage required for the experiment through the power frequency withstand voltage test device 200, and then the power frequency withstand voltage test device 200 is charged to the voltage required for the experiment, and then the power frequency withstand voltage test device 200 is disconnected from the high-voltage capacitor 71; the delay pulse generator 100 outputs a high level to the ignition circuit relay 720 at first, and drives the ignition circuit relay 720 to close, so that the ignition circuit is conducted, and the ignition wire 13 is energized and heated; after a predetermined period of time, delay When the pulse generator 100 outputs a high level to the unloading circuit relay 730 again, the driving unloading circuit relay 730 is closed, and the unloading circuit is also conducted. At this time, the voltage of the positive electrode of the ignition wire is not enough to break down the combustion products, wherein the predetermined time is 5-30 milliseconds.

It can be known from the above embodiments that the pulse discharge ignition system used in the coaxial cylindrical deflagration driving device provided by this embodiment at least achieves the following beneficial effects:

In this embodiment, the ignition circuit is formed by connecting the ignition circuit relay 720, the ignition wire 13 and the high-voltage capacitor 71 in series, and the high-voltage capacitor 71 and the unloading circuit relay 730 are connected in series to form an unloading circuit. The circuit relays are respectively electrically connected with the delay pulse generator, which can realize the ignition mode of the deflagration drive technology, that is, the high-voltage discharge with a duration of milliseconds. After a predetermined time, the positive and negative electrodes of the high-voltage capacitor are short-circuited by the unloading circuit. , so that the voltage of the high-voltage capacitor drops to a very low value within milliseconds, so that the voltage across the ignition wire is not enough to cause breakdown.

Fig. 3 is a structural schematic diagram of a coaxial cylindrical deflagration driving device for a shock tube/wind tunnel provided by an embodiment of the present invention; Fig. 4 is an enlarged view of the structure at B in Fig. 3; Fig. 5 is a pulse in Fig. 3 An enlarged view of the structure of the discharge ignition system; FIG. 6 is a logical block diagram of a pulse discharge ignition system provided by an embodiment of the present invention. As shown in Figures 3-6, this embodiment provides a coaxial cylindrical deflagration driving device for shock tubes/wind tunnels, including a deflagration driving section 1, a driven section 2, and a deflagration driving section 1 The diaphragm 5, the blind plate 14 and the pulse discharge ignition system 7 separated from the driven section 2, wherein one end of the deflagration driving section 1 is connected to the driven section 2, and the other end is connected to the blind plate 14;

The deflagration driving section 1 is a straight tube with equal cross-section. The first electrode 11 and the second electrode 12 extending along the radial direction Y are inserted into the deflagration driving section 1. The first electrode 11 is located on the side of the deflagration driving section close to the blind plate 14. The two electrodes 12 are located on the side of the deflagration driving section 1 close to the driven section 2, and the ignition wire 13 extending along the axial direction X is electrically connected between the first electrode 11 and the second electrode 12, and the axial direction X is directed by the deflagration driving section 1. The direction of the shaft centerline of the driven section 2, where the radial direction Y intersects the axial direction X;

Along the axis X, the length between the first electrode 11 and the blind plate 14 is L1, the length between the second electrode 12 and the diaphragm 5 is L2, and the lengths of L1 and L2 are limited to 0.5cm-20cm;

The deflagration driving section 1 is provided with an opening 8 matching the first electrode 11 and the second electrode 12, and a sealing ring 81 is provided on the contact surface of the first electrode 11, the second electrode 12 and the opening 8;

The deflagration driving section 1 is filled with combustible gas mixture;

The pulse discharge ignition system 7 comprises a time-delay pulse generator 100, a high-voltage capacitor 71, an ignition circuit relay 720, an unloading circuit relay 730, and a power frequency withstand voltage test device 200. The positive electrode of the high-voltage capacitor 71, the ignition circuit relay 720, and the first electrode 11. The ignition wire 13, the second electrode 12, and the negative pole of the high-voltage capacitor 71 constitute the ignition circuit 72; the positive pole of the high-voltage capacitor 71, the unloading circuit relay 730 and the negative pole of the high-voltage capacitor 71 constitute the unloading circuit 73; the ignition circuit 72 and the unloading circuit 73 In parallel, the high-voltage capacitor 71 is used to store high-voltage electricity and discharge to the ignition wire; the ignition circuit relay 720 and the unloading circuit relay 730 are electrically connected to the delay pulse generator 100 respectively; the power frequency withstand voltage test device 200 and the high-voltage capacitor 71 Electrically connected, the power frequency voltage withstand test device 200 is used to charge the high voltage capacitor 71 .

Specifically, the coaxial cylindrical deflagration driving device for a shock tube/wind tunnel includes a deflagration driving section 1 and a driven section 2. One end of the deflagration driving section 1 is connected to the driven section 2, and the other end is connected to a blind plate 14. A diaphragm 5 is set between the driving section 1 and the driven section 2, the driven section 2 is connected to the test section 4 through the nozzle 3, the blind plate 14 is a flange cover, and the end of the deflagration driving section 1 is blocked by the blind plate 14, It is no longer necessary to use the traditional deflagration section and to set a diaphragm between the deflagration section and the deflagration driving section, which not only helps to reduce the occupied space, but also reduces the cost;

A first electrode 11 and a second electrode 12 extending in the radial direction Y are plugged into the deflagration driving section 1. The first electrode 11 is located on the side of the deflagration driving section 1 close to the blind plate 14, and the second electrode 12 is located on the side of the deflagration driving section 1 close to the blind plate 14. One side of the driven section 2, that is to say, the first electrode 11 and the second electrode 12 are plugged into the two ends of the deflagration driving section 1; between the first electrode 11 and the second electrode 12 is electrically connected a The ignition wire 13, the axial direction X is the direction from the blind plate 14 to the axis centerline of the driven section 2, and the radial direction Y intersects the axial direction X. Optionally, the ignition wire 13 can be made of copper, silver, nickel chromium, Any metal material in tungsten and alloy, the length of the ignition wire 13 can be adjusted according to the length of the deflagration driving section 1;

The axial distance between the first electrode 11 and the blind plate 14 is L1, and the axial distance between the second electrode 12 and the diaphragm 5 is L2. If the length of L1 and L2 is less than 0.5 cm, breakdown may occur, resulting in equipment damage or Dangerous to personnel safety; if the length of L1 and L2 is greater than 20cm, it may lead to unstable combustion of the combustible gas mixture in the deflagration driving section 1. Therefore, the length of L1 and L2 is limited to 0.5cm-20cm, not only the ignition wire 13 is arranged longer in the axial direction in the deflagration driving section, which can further make the combustion of the combustible gas mixture in the deflagration driving section 1 more complete, and can avoid the gap between the first electrode 11 and the end of the deflagration driving section and the second electrode. The distance between 12 and diaphragm 5 is too short to avoid breakdown and ensure the safety of equipment and personnel;

Fig. 4 is an enlarged view of the structure at B in Fig. 3; wherein, the enlarged view at C in Fig. 3 is the same as the enlarged view at B, and the deflagration driving section 1 is provided with the first electrode 11 and the second electrode 12 to cooperate In order to show the opening 8 on the figure in Fig. 4, the aperture of the opening 8 is drawn larger than the actual one, the opening 8 is matched with the first electrode 11, and the second electrode 12 is matched with the opening 8 Cooperate, it is convenient to insert the first electrode 11 and the second electrode 12 in the combustion driving section 1 through the opening 8, in order to ensure the sealing in the deflagration driving section 1, after the first electrode 11 is plugged into the deflagration driving section 1, A sealing ring 81 is arranged on the contact surface of the deflagration driving section 1 where the first electrode 1 is in contact with the opening 8, and a sealing ring 81 is arranged on the contact surface of the deflagration driving section 1 where the second electrode 12 contacts the opening 8;

The deflagration driving section 1 is filled with combustible gas mixture, which can include fuel, oxidant and inert gas, wherein the fuel is hydrogen, carbon monoxide or alkenyne, and can also be other combustible gases; the oxidant is oxygen or dioxide Nitrogen can also be other oxidizing gases, inert gases can be nitrogen, rare gases or carbon dioxide, or other gases that do not participate in combustion reactions; the ratio of fuel: oxidant: inert gas can be 1:1:1, fuel : The ratio between oxidant: inert gas can also be 2:1:1, the ratio between fuel: oxidant: inert gas can also be 2:1:7, of course, about the ratio of fuel, oxidant and inert gas The relationship is set according to specific equipment and experimental requirements;

Also includes pulse discharge ignition system 7, pulse discharge ignition system 7 includes delay pulse generator 100, high voltage capacitor 71, ignition circuit relay 720, unloading circuit relay 730 and power frequency withstand voltage test device 200, high voltage capacitor 71 positive pole, ignition The circuit relay 720, the first electrode 11, the ignition wire 13, the second electrode 12, and the negative pole of the high-voltage capacitor 71 constitute the ignition circuit 72; 72 is connected in parallel with the unloading circuit 73, and the high-voltage capacitor 71 is used to store high-voltage electricity; about the models of the delay pulse generator 100, the high-voltage capacitor 71, the ignition circuit relay 720, the unloading circuit relay 730 and the power frequency withstand voltage test device 200 Same as the models of the delay pulse generator 100, the high-voltage capacitor 71, the ignition circuit relay 720, the unloading circuit relay 730 and the power frequency withstand voltage test device 200 in the above-mentioned pulse discharge ignition system for the coaxial cylindrical deflagration drive device, No more details here;

The working principle of the pulse discharge ignition system 7 is as follows: first charge the high-voltage capacitor 71 to the voltage required for the experiment through the power frequency withstand voltage test device 200, and then disconnect the power frequency withstand voltage test device 200 from the high-voltage capacitor 71; The device 100 first outputs a high level to the ignition circuit relay 720, drives the ignition circuit relay 720 to close, and makes the ignition circuit 72 conductive, and a high voltage of several thousand to tens of thousands of volts is applied to both ends of the ignition wire 13. , the ignition wire 13 heats up violently; after a predetermined time, the delay pulse generator 100 outputs a high level to the unloading circuit relay 730 to drive the unloading circuit relay 730 to close, so that the unloading circuit 73 is also turned on. At this time, the high voltage The positive and negative poles of the capacitor 71 are short-circuited, and the voltage of the high-voltage capacitor 71 drops to a very low value within milliseconds. At this time, the voltage at both ends of the ignition wire 13 is not enough to cause breakdown. The predetermined time is 5-30 milliseconds.

The assembly sequence for this Coaxial Cylindrical Deflagration Drive for Shock Tube/Wind Tunnel is as follows:

Provide deflagration driving section 1;

First, the opening 8 for placing the first electrode 11 and the second electrode 12 is provided on the deflagration driving section 1; secondly, a sealing ring 81 is installed on the contact surface between the first electrode 11 and the second electrode 12 and the opening 8, and the Insert the first electrode 11 and the second electrode 12 in the opening 8, the first electrode 11 is located on the side of the deflagration driving section close to the blind plate 14, and the second electrode 12 is located on the side of the deflagration driving section 1 close to the driven section 2; An ignition wire 13 extending along the axis X is connected between the first electrode 11 and the second electrode 12;

A diaphragm is installed between the deflagration driving section 1 and the driven section 2, and one end of the deflagration driving section 1 close to the diaphragm 5 is connected to the driven section 2, and the other end is connected to a blind plate 14;

The deflagration driving section 1 is filled with combustible gas mixture;

Connect the pulse discharge ignition system 7, form the ignition circuit 72 with the positive pole of the high voltage capacitor 71, the ignition circuit relay 720, the first electrode 11, the ignition wire 13, the second electrode 12, and the negative pole of the high voltage capacitor 71; connect the positive pole of the high voltage capacitor 71, the unloading circuit The relay 730 and the negative pole of the high-voltage capacitor 71 form an unloading circuit 73; the ignition circuit 72 and the unloading circuit 73 are connected in parallel.

Assembling the coaxial cylindrical deflagration driving device for the shock tube/wind tunnel according to the above assembly sequence can not only better insert the first electrode and the second electrode, but also make the position of the ignition wire 13 more accurate, Moreover, it can avoid leakage of combustible gas mixture, ensure personal safety, and is convenient for operation.

Of course, without considering the discharge of the high-voltage capacitor to the ignition wire, the above-mentioned assembly sequence can be adjusted appropriately. After the driven section 2 or the blind plate 14 is installed, the pulse discharge ignition system can be connected first, and then the deflagration drive section 1 is filled with combustible gas mixture, as follows:

First, provide a deflagration driving section 1;

Second, at first, on the deflagration driving section 1, there are openings 8 for placing the first electrode 11 and the second electrode 12; secondly, a sealing ring is installed on the contact surface between the first electrode 11 and the second electrode 12 and the opening 8 81, insert the first electrode 11 and the second electrode 12 in the opening 8, the first electrode 11 is located on the side of the deflagration driving section close to the blind plate 14, and the second electrode 12 is located on the side of the deflagration driving section 1 close to the driven section 2 ; An ignition wire 13 extending along the axis X is connected between the first electrode 11 and the second electrode 12 ;

Thirdly, a diaphragm is installed between the deflagration driving section 1 and the driven section 2, and one end of the deflagration driving section 1 close to the diaphragm 5 is connected to the driven section 2, and the other end is connected to a blind plate 14;

The 4th, connect pulse discharge ignition system 7, form ignition circuit 72 with high-voltage capacitor 71 positive pole, ignition circuit relay 720, first electrode 11, ignition wire 13, second electrode 12, high-voltage capacitor 71 negative pole; High-voltage capacitor 71 positive pole, The unloading circuit relay 730 and the negative pole of the high voltage capacitor 71 constitute the unloading circuit 73; the ignition circuit 72 and the unloading circuit 73 are connected in parallel;

Fifth, the deflagration driving section 1 is filled with combustible gas mixture.

It should be noted that: first, a deflagration driving section 1 is provided; secondly, firstly, openings 8 for placing the first electrode 11 and the second electrode 12 are provided on the deflagration driving section 1; secondly, the first electrode 11 and the A sealing ring 81 is installed on the contact surface between the second electrode 12 and the opening 8, and the first electrode 11 and the second electrode 12 are inserted in the opening 8. The first electrode 11 is located at the side of the deflagration driving section close to the blind plate 14, and the second The electrode 12 is located on the side of the deflagration driving section 1 close to the driven section 2; the ignition wire 13 extending along the axial direction X is connected between the first electrode 11 and the second electrode 12; thirdly, between the deflagration driving section 1 and the driven section Install a diaphragm between the two, connect the driven segment 2 to the end of the deflagration driving segment 1 close to the diaphragm 5, and connect the blind plate 14 to the other end; the assembly sequence of the above three steps is irreversible, that is, the above assembly sequence cannot be reversed. It cannot be implemented after being reversed.

The working principle is as follows: in the deflagration driving section 1, there is an ignition wire 13 arranged along the axial direction X, and the high-voltage capacitor 71 is charged to the voltage required for the experiment through the power frequency withstand voltage test device 200, and then the power frequency withstand voltage test device 200 Disconnect with the high-voltage capacitor 71; the delay pulse generator 100 first outputs a high level to the ignition circuit relay 720, drives the ignition circuit relay 720 to close, and makes the ignition circuit conduction, and applies thousands to tens of thousands of volts to both ends of the ignition wire 13 High voltage, at the moment when the ignition circuit relay 720 is energized, the ignition wire 13 heats up violently, ignites the combustible gas mixture near the ignition wire 13 within milliseconds, forms a columnar flame surface after ignition, and expands in the radial direction; by making the ignition The wire 13 is strictly coaxial with the pipeline of the deflagration driving section 1 to ensure simultaneous combustion everywhere in the axial direction; since the discharge process of the high-voltage capacitor 71 is longer than the combustion process, it is necessary to discharge the remaining charge in the high-voltage capacitor 71 before the end of combustion. Therefore, after a predetermined time, the delay pulse generator 100 outputs a high level to the unloading circuit relay 730 to drive the unloading circuit relay to close, so that the unloading circuit is also turned on. At this time, the positive and negative poles of the high voltage capacitor 71 Short circuit, the voltage of the high-voltage capacitor 71 drops to a very low value within milliseconds. It can be understood that the charge in the high-voltage capacitor 71 returns to the high-voltage capacitor 71 instantly through the unloading circuit to complete the unloading, thereby preventing the positive electrode of the high-voltage capacitor 71 from Nearby breakdown combustion products, resulting in safety accidents.

It should be noted that the detonation drive needs to form a detonation wave propagating axially in the pipeline of the driving section, while the deflagration drive is to ignite the gas in the pipeline of the deflagration driving section 1 simultaneously in the axial direction, so as to detonate instead of detonate. The combustion is completed in a bombing manner, and the combustion is simultaneously completed along the axis X.

Generally, the effective working time of the shock tube/wind tunnel is on the order of a few milliseconds to 100 milliseconds. In order to provide accurate test conditions, it is necessary to strictly ensure that the combustible gas mixture in the deflagration driving section is ignited and burned out at the same time.

It can be seen from the above embodiments that the coaxial cylindrical deflagration driving device for shock tube/wind tunnel provided by the present invention at least achieves the following beneficial effects:

First, in the prior art, the detonation drive forms a detonation wave propagating axially in the pipeline of the driving section. Since the extremely high pressure peak of the detonation wave cannot be used for driving, the effective pressure provided by the detonation drive is much lower. Due to the pressure limit of the equipment, detonation is replaced by detonation in the present invention, there is no pressure peak in detonation, and the combustion pressure can be 100% used to compress the test gas, thus increasing the pressure of the test gas;

Second, the mixture ratio limit of deflagration is much wider than that of detonation, the temperature and sound velocity range of the driving gas is larger, and the corresponding total temperature range of the test gas is therefore larger than that of detonation driving;

Third, the ignition method of deflagration drive technology can be realized through the pulse discharge ignition system, that is, the high-voltage discharge with a duration of milliseconds. The voltage drops to a very low value in milliseconds, so that the positive voltage of the ignition wire is not enough to cause breakdown.

Fig. 7 is a schematic structural diagram of a shock tube/wind tunnel provided by an embodiment of the present invention; an embodiment of the present invention also has a shock tube/wind tunnel, including a shock tube/wind tunnel provided by an embodiment of the present invention The coaxial cylindrical deflagration drive device.

It can be known from the above embodiments that the pulse discharge ignition system for the coaxial cylindrical deflagration driving device provided by the present invention at least achieves the following beneficial effects:

In the present invention, an ignition circuit is formed by connecting an ignition circuit relay, an ignition wire and a high-voltage capacitor in series; the high-voltage capacitor and an unloading circuit relay are connected in series to form an unloading circuit; the ignition circuit and the unloading circuit are connected in parallel; The electrical connection of the pulse generator can realize the ignition method of the deflagration drive technology, that is, the high-voltage discharge with a duration of milliseconds. Within milliseconds it drops to such a low value that the voltage across the ignition wire is insufficient to cause breakdown.

Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and not intended to limit the scope of the present invention. Those skilled in the art will appreciate that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (4)

1. A pulse discharge ignition system for a coaxial cylinder deflagration drive unit, characterized in that it comprises a time-delay pulse generator, an ignition circuit relay, an unloading circuit relay, an ignition wire, a high voltage capacitor and a power frequency withstand voltage test device; The positive pole of the high-voltage capacitor, the ignition circuit relay, the ignition wire and the negative pole of the high-voltage capacitor constitute an ignition circuit, and the positive pole of the high-voltage capacitor, the relay of the unloading circuit and the negative pole of the high-voltage capacitor constitute an unloading circuit. The ignition circuit is connected in parallel with the unloading circuit, and the high voltage capacitor is used to store high voltage and discharge to the ignition wire; The ignition circuit relay and the unloading circuit relay are respectively electrically connected to the delay pulse generator, and both the ignition circuit relay and the unloading circuit relay are JPK-58A gas-filled high-voltage relays; The power frequency withstand voltage test device is electrically connected to the high-voltage capacitor, and the power frequency withstand voltage test device is used to charge the high-voltage capacitor. The high-voltage capacitor adopts a DAWNCAPDTH-20000 high-voltage pulse capacitor, and the DAWNCAPDTH-20000 The high-voltage pulse capacitor generates a high voltage of 20000V; The delay pulse generator first outputs a high level to the ignition circuit relay, drives the ignition circuit relay to close, makes the ignition circuit conduction, and the ignition wire is energized and heated. After a predetermined time, the delay When the pulse generator outputs a high level to the unloading circuit relay, it drives the unloading circuit relay to close, so that the unloading circuit is also turned on, and the positive and negative poles of the high-voltage capacitor are short-circuited, wherein the predetermined time 5-30 milliseconds. 2. The pulse discharge ignition system for a coaxial cylindrical deflagration driving device according to claim 1, wherein the ignition wire is made of metal. 3. The pulse discharge ignition system for a coaxial cylindrical deflagration drive device according to claim 2, wherein the metal material is any one of copper, silver, nickel-chromium, tungsten and alloys. 4. The pulse discharge ignition system for a coaxial cylindrical deflagration drive device according to claim 1, wherein the delay pulse generator is a DG535 four-channel digital delay pulse generator.