CN115155681A

CN115155681A - Membrane-free shock tube and sampling system

Info

Publication number: CN115155681A
Application number: CN202210767410.3A
Authority: CN
Inventors: 王昆; 白世杰; 沈位; 梁兴雨; 罗逸伦
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2022-10-11
Anticipated expiration: 2042-06-30
Also published as: CN115155681B

Abstract

The invention provides a film-free shock tube, comprising: a first pipe extending in a first direction and adapted to be filled with a first gas; at least one second duct extending in a second direction orthogonal to the first direction, adapted to be filled with a second gas and communicating with the first duct; a shut-off mechanism comprising: a shut-off assembly, at least a portion of the shut-off assembly being configured to move in a first direction between a first position extending into the first conduit and a second position disengaged from the first conduit; and an actuating assembly connected to the stopping assembly and adapted to hold the stopping assembly in or out of the first position; when the cut-off assembly is located at the second position, the first pipeline and the second pipeline are conducted to form shock waves in the first pipeline based on the pressure difference of the second gas and the first gas. The invention also provides a sampling system which comprises the membrane-free shock tube and the gas chromatography-mass spectrometer.

Description

Membrane-free shock tube and sampling system

Technical Field

The invention relates to the technical field of non-contact spectrum test research of gas temperature in a combustor, in particular to a membrane-free shock tube and a sampling system.

Background

Shock tubes, as an approximate zero-dimensional reactor, have been considered as the first equipment to study the kinetics of high temperature chemical reactions. The conventional shock tube is a stainless steel vessel of circular or square cross-section divided into two parts, high pressure and low pressure, by a thin polyester membrane. At room temperature, the low pressure section was filled with the test mixture and the drive section was filled with inert gas to high pressure until the diaphragm ruptured. When the diaphragm ruptures, the large pressure differential causes a series of compression waves to propagate from the high pressure side to the low pressure side; these compressional waves add together to form the incident shock wave.

The non-ideal rupture of the diaphragm of the traditional shock tube can cause small diaphragm particles to enter a test area along with driving gas, serious errors are generated on an experimental result, and the diaphragm can generate non-negligible influence on the front edge of the expansion flame when the flame speed is tested. Moreover, due to the limited opening time of the diaphragm, the speed of the incident shock wave deviates from a theoretical value, and the boundary layer is remarkably increased, so that the attenuation of the incident shock wave is serious; meanwhile, due to the fact that incident shock waves are reflected from the end wall in an imperfect mode, temperature gradients exist in the area after the shock waves are reflected, temperature and pressure changes tend to be serious along with the increase of observation time, and the temperature and pressure changes are represented as the fact that the temperature and pressure fields are not distributed uniformly.

Therefore, the traditional shock tube has the problems of low repeatability, interference experiment of fragments of the diaphragm, long experiment period, large measurement uncertainty and the like.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a membrane-free shock tube and a sampling system, wherein a stop component is kept at a relative position extending into or separating from a first pipeline through an actuating component so as to realize the closing or the conduction of the first pipeline and a second pipeline, so that a second gas enters the first pipeline to form a shock wave under the state that the first pipeline and the second pipeline are conducted.

In order to achieve the above object, there is provided as the present disclosure a membrane-free shock tube including: a first pipe extending in a first direction and adapted to be filled with a first gas; at least one second duct extending in a second direction orthogonal to said first direction, suitable for being filled with a second gas and communicating with said first duct; a shut-off mechanism comprising: a stop assembly, at least a portion of the stop assembly configured to move in a first direction between a first position extending into the first conduit and a second position disengaged from the first conduit; and an actuating assembly connected to the stopping assembly and adapted to hold the stopping assembly in or out of the first position; when the cut-off assembly is located at the second position, the first pipeline and the second pipeline are communicated to form shock waves in the first pipeline based on the pressure difference of the second gas and the first gas.

In an exemplary embodiment, the method further comprises: the third pipeline is arranged at the end part of the first pipeline, which is opposite to the second pipeline, and is communicated with the first pipeline; the fourth pipeline is arranged at the end part of the third pipeline, which is opposite to the first pipeline, and is communicated with the third pipeline; the inner diameter of the third pipeline is gradually reduced from the end close to the first pipeline to the end far away from the first pipeline; and a detection window and a sampling channel are arranged in the fourth pipeline.

In an exemplary embodiment, the actuating assembly is configured to apply an adjustable pressure to the stop assembly, the stop assembly is maintained in the first position in a state where the pressure applied by the actuating assembly is greater than or equal to the pressure applied by the first and second gases to the stop assembly, and the stop assembly is moved from the first position to the second position in a state where the pressure applied by the actuating assembly is less than the pressure applied by the first and second gases to the stop assembly.

In an exemplary embodiment, the cutoff assembly includes: the fixing part is arranged on the first pipeline and/or the second pipeline; the movable part is sleeved in the fixed part, the other movable parts are sleeved in the adjacent movable parts step by step, at least one movable part extends into the first pipeline to seal the first pipeline and the second pipeline in the state of the first position, and each movable part is separated from the first pipeline to conduct the first pipeline and the second pipeline in the state of the second position; the fixing part comprises a first end cover, and the first end cover is arranged on the second pipeline; the multistage moving section includes: a first sleeve sleeved in the first end cover, wherein a first end of the first sleeve, which is configured to face the second pipeline, moves between a third position extending from the first end cover and a fourth position retracting into the first end cover; the second end of the first piston is sleeved in the first sleeve, the third end, opposite to the second end, of the first piston is configured to move between the first position and the second position, the second end extends outwards along the circumferential direction to form a first flange, the first flange abuts against the opposite end face of the first sleeve in the state that the first sleeve is located at the third position so as to keep the first piston at the first position, the first piston and the first sleeve move synchronously in the state that the first sleeve is moved from the third position to the fourth position, and the first flange is separated from the first sleeve and the first piston moves to the second position in the state that the first sleeve is kept at the fourth position; the radial middle part of the end part of the third end extends towards the first direction to form a first protruding part, and an arc-shaped surface is formed between the first protruding part and the outer edge of the third end so as to guide the second gas to enter the first pipeline along the arc-shaped surface.

In an exemplary embodiment, a plurality of first air guide holes are circumferentially arranged on the side wall of the first end cover at one axial position, a plurality of second air guide holes are circumferentially arranged on the side wall of the first end cover at the other axial position, and a plurality of third air guide holes are circumferentially arranged on the side wall of the first sleeve at the axial position corresponding to the second air guide holes; wherein the first sleeve and the first end cap define a first chamber therebetween, the first chamber being in communication with the second conduit through the first gas vent adapted to direct the second gas into the first chamber to apply a portion of the first pressure to the first sleeve, the first piston and the first sleeve defining a second chamber therebetween, the second gas vent being in communication with the third gas vent in a state in which the first sleeve is in the fourth position, the second gas vent being adapted to direct the second gas into the second chamber to apply a portion of the first pressure to the first piston.

In one illustrative embodiment, the actuation assembly comprises: the pressure applying part is arranged on the first end cover and is suitable for being filled with third gas so as to apply second pressure to the first sleeve and the first piston through the third gas; and a releasing portion provided on the pressing portion and configured to move between a fifth position closing the pressing portion and a sixth position opening the pressing portion; when the releasing portion is in the fifth position, the third gas is enclosed among the pressing portion, the first sleeve and the first piston to apply a second pressure higher than the first pressure to the first sleeve and the first piston, and when the releasing portion is in the sixth position, the third gas is exhausted to the air environment to make the second pressure lower than the first pressure.

In an exemplary embodiment, the pressing part includes: a fourth sleeve of the second sleeve, which faces the first end cover, is sleeved in the first end cover, and a plurality of first exhaust holes are circumferentially arranged on a side wall of the second sleeve, so that the inside of the second sleeve is communicated with the external gas environment; the second end cover is arranged at the end part of the second sleeve, which is opposite to the first end cover, and a third chamber is defined among the second end cover, the second sleeve, the first end cover, the first sleeve and the first piston; the second piston is sleeved in the second sleeve and moves between a seventh position for sealing the first exhaust hole and an eighth position for opening the first exhaust hole, the third cavity is divided into a first sub cavity and a second sub cavity by the second piston, and the second piston is provided with a pressure equalizing hole which is suitable for communicating the first sub cavity and the second sub cavity; the end part of the fourth end, which faces the first sleeve, extends towards the first sleeve to form a first limiting part, and the inner diameter of the first limiting part is larger than or equal to the outer diameter of the first piston, so that the first sleeve is limited to the fourth position, the first piston is allowed to pass through the first limiting part, and the first limiting part is abutted to the fourth end when the first piston moves to the second position; the second end cover is provided with an air inlet communicated with the third chamber, the third chamber is suitable for being introduced with the third gas through the air inlet, and a first valve is arranged in the air inlet and is suitable for conducting or closing the air inlet.

In an exemplary embodiment, the second end cap is provided with at least one fourth air vent along an axial direction, and the releasing portion includes: a third sleeve disposed over the second end cap, the third sleeve and the second end cap defining a fourth chamber therebetween; the third piston is sleeved in the third sleeve and is configured to move between a fifth position where the fourth air guide hole is closed and a sixth position where the fourth air guide hole is opened; the third piston divides the fourth chamber into a third sub-chamber and a fourth sub-chamber, a second exhaust hole is formed in the side wall of the third sleeve in the third sub-chamber, a third exhaust hole is formed in the side wall of the third sleeve in the fourth sub-chamber, and second valves are arranged in the second exhaust hole and the third exhaust hole and are suitable for communicating or closing the second exhaust hole and/or the third exhaust hole with the external air environment.

In an exemplary embodiment, an inner surface of the sidewall of the third sleeve extends radially inward to form a second stopper adapted to hold the third piston in the sixth position; wherein, when the third piston is in the sixth position, the second and third exhaust ports are both in an open state communicating the fourth chamber with the outside air environment.

The sampling system comprises a membrane-free shock tube and a gas chromatography-mass spectrometer, and is communicated with a sampling channel of the membrane-free shock tube.

According to the membrane-free shock tube and the sampling system disclosed by the invention, the first pipeline is communicated with the second pipeline, and the actuating assembly is suitable for driving the stopping assembly to move between the first position and the second position. When the cut-off assembly is in the first position, the first pipeline and the second pipeline are closed. When the cut-off component is in the second position state, the first pipeline is communicated with the second pipeline, and second gas in the second pipeline enters the first pipeline so as to form shock waves in the first pipeline through the pressure difference of the second gas and the first gas.

Drawings

FIG. 1 is a cross-sectional view of a membraneless shock tube according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic view of the exemplary embodiment of FIG. 1 with the shutoff assembly in a first position;

FIG. 3 is a schematic view of the exemplary embodiment of FIG. 1 with the shutoff assembly in a second position;

FIG. 4 is a cross-sectional view of a fourth pipe section of the illustrative embodiment shown in FIG. 1; and

FIG. 5 is a block diagram of a sampling system according to an exemplary embodiment of the present invention.

In the above figures, the reference numerals have the following meanings:

1. a first conduit;

2. a second conduit;

3. a third pipeline;

4. a fourth conduit;

41. a second pair of windows;

42. a sampling port;

43. a first pair of windows;

44. a window;

45. a sampling channel;

46. a pressure sensor;

5. unloading the tank;

6. a cut-off mechanism;

61. a shut-off assembly;

611. a first sleeve;

6111. a third air guide hole;

612. a first piston;

613. a first end cap;

6131. a first air guide hole;

6132. a second air-guide hole;

62. a pressing part;

621. a second sleeve;

6211. a first exhaust port; 6212. a fourth end;

6213. a first limiting part; 6214. a damping exhaust hole;

622. a second piston;

6221. a pressure equalizing hole;

623. a second end cap;

6231. an air inlet;

6232. a fourth air guide hole;

63. a releasing section;

631. a third sleeve;

6311. a second vent hole; 6312. a third exhaust hole; 6313. a second limiting part;

64. a first chamber;

65. a second chamber;

66. a third chamber;

67. a fourth chamber;

7. a gas chromatograph-mass spectrometer;

8. a first gas mixing tank;

9. a vacuum pump; and 10, a second gas mixing tank.

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The terms "comprises," "comprising," and the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components. All terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.

In this document, unless otherwise specifically stated, directional terms such as "upper", "lower", "left", "right", "inside", "outside", and the like are used to indicate orientations or positional relationships based on the illustrated drawings, and are merely for convenience in describing the present invention, and do not indicate or imply that the referenced device, element, or component must have a particular orientation, be constructed or operated in a particular orientation. It should be understood that when the absolute positions of the described objects are changed, the relative positional relationships they represent may also change accordingly. Accordingly, these directional terms should not be construed as limiting the present invention.

Where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). Where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.).

FIG. 1 is a cross-sectional view of a membraneless shock tube according to an exemplary embodiment of the invention.

An exemplary embodiment of the present invention provides a membrane-less shock tube, as shown in fig. 1, including a first tube 1, at least one second tube 2, and a stopping mechanism 6. The first duct 1 extends in a first direction and is adapted to be filled with a first gas. The second duct 2 extends in a second direction orthogonal to the first direction, is suitable for being filled with a second gas and communicates with the first duct 1. The shut-off mechanism 6 includes a shut-off assembly 61 and an actuating assembly, at least a portion of the shut-off assembly 61 being configured to move in a first direction between a first position extending into the first conduit 1 and a second position disengaged from the first conduit 1. The actuating assembly is coupled to the stop assembly 61 and is adapted to hold the stop assembly 61 in or out of the first position. When the cut-off module 61 is at the first position, the first pipe 1 and the second pipe 2 are closed, and when the cut-off module 61 is at the second position, the first pipe 1 and the second pipe 2 are connected to form a shock wave in the first pipe 1 based on the pressure difference between the second gas and the first gas.

In such an embodiment, the actuating assembly is adapted to drive the blocking assembly 61 to the first position or to the second position, and the first pipe 1 and the second pipe 2 are conducted in the process of moving from the first position to the second position. Therefore, a diaphragm does not need to be arranged between the first pipeline 1 and the second pipeline 2, and the influence of non-ideal fragmentation of the diaphragm on the test of the traditional shock tube can be effectively prevented.

In an exemplary embodiment, the first direction is characterized as a horizontal direction (up and down as shown in fig. 1) and the second direction is characterized as a vertical direction (left and right as shown in fig. 1).

In an exemplary embodiment, the first conduit 1 comprises, but is not limited to, a cylindrical conduit.

In detail, the first pipe 1 is constructed with an inner diameter including, but not limited to, 210 mm and a wall thickness including, but not limited to, 50 mm.

Further, the first pipeline 1 is provided with at least one gas inlet suitable for introducing the first gas and at least one gas outlet suitable for discharging at least a part of the first gas.

Further, as shown in fig. 1, the first pipe 1 is provided with an unloading tank 5 adapted to absorb the reflected shock wave. Such an embodiment can effectively prevent secondary heating of the shock wave.

In an exemplary embodiment, six second tubes 2 are included, and each second tube 2 includes, but is not limited to, a ring tube.

In detail, each toroidal tube is configured 1500 mm long, with an inner diameter including but not limited to 210 mm and a wall thickness including but not limited to 50 mm.

Further, the outlet sides of the six second pipelines 2 are collected at the inlet side of the first pipeline 1.

Further, the roughness of the inner wall of the second pipe 2 is configured to Ra (surface roughness unit) <0.8, a pressure-bearing capacity of 1000atm (one standard atmosphere) or more, and a temperature of 2000K (kelvin) or more.

In an exemplary embodiment, the second pipe 2 is provided with at least one inlet for the second gas and a pressure relief opening for pressure relief.

Further, a pressure sensor 46 and/or a vacuum gauge are provided on the second pipe 2.

In an exemplary embodiment, the first gas includes, but is not limited to, a mixture of one or more of oxygen, nitrogen, air, carbon monoxide, carbon dioxide, nitric oxide, and water vapor.

Further, the second gas includes, but is not limited to, one or more of acetylene, hydrogen, oxygen, nitrogen, argon, helium, and other inert gases.

Furthermore, the pressure of the second gas in the second pipeline 2 is greater than the pressure of the first gas in the first pipeline 1, so that the second gas can enter the first pipeline 1 to form a shock wave with the first gas in the state that the second pipeline 2 is communicated with the first pipeline 1.

In such an embodiment, shock waves with mach numbers greater than 1.6 can be generated during the test by setting the above parameters (including, but not limited to, the first conduit 1, the second conduit 2, the first gas, and the second gas).

Fig. 4 is a cross-sectional view of a fourth pipe section of the illustrative embodiment shown in fig. 1.

According to an embodiment of the present disclosure, as shown in fig. 1 and 4, the membrane-less shock tube further includes a third tube 3 and a fourth tube 4. The third pipeline 3 is disposed at an end (an upper end as shown in fig. 1) of the first pipeline 1 opposite to the second pipeline 2, and is communicated with the first pipeline 1. The fourth pipe 4 is disposed at an end (an upper end as shown in fig. 1) of the third pipe 3 opposite to the first pipe 1, and is communicated with the third pipe 3. The inner diameter of the third pipe 3 gradually decreases from an end portion close to the first pipe 1 (a lower end as viewed in fig. 1) to an end portion remote from the first pipe 1 (an upper end as viewed in fig. 1). A detection window and a sampling channel 45 are arranged in the fourth pipeline 4.

In an exemplary embodiment, the inner diameter of the end of the third conduit 3 facing the first conduit 1 (the lower end as viewed in fig. 1) is configured to conform to the inner diameter of the first conduit 1.

In detail, as shown in fig. 1, the inner diameter of the upper end of the third tube 3 is configured to be 105 mm, and the inner diameter of the lower end of the third tube 3 is configured to be 210 mm.

Further, the wall thickness of the upper end of the third pipe 3 is configured to be 30 mm, and the wall thickness of the lower end of the third pipe 3 is configured to be 50 mm. In such an embodiment, the third conduit 3 is used to enhance the intensity of the laser.

In an exemplary embodiment, the fourth conduit 4 is provided with a plurality of pressure sensors 46 spaced along the first direction and adapted to acquire pressure signals at different axial locations within the fourth conduit 4.

In detail, including but not limited to three pressure sensors 46, the three pressure sensors 46 are disposed on the same side of the fourth pipe 4.

In an exemplary embodiment, the end of the fourth tube 4 remote from the third tube 3 is provided with a third end cap.

In detail, the third end cap is provided with a viewing window 44 and a sampling channel 45.

Further, the window 44 cooperates with a photomultiplier tube (PMT) for ignition delay time measurement for high speed imaging of the end wall surface. The sampling channel 45 is combined with a gas chromatography-mass spectrometer 7 (GC-MS) flight mass spectrometer (TOF-MS) to perform online sampling measurement on species intermediate product distribution and the like.

In an exemplary embodiment, the radial sidewall of the fourth pipe 4 is further provided with a sampling port 42 adapted to sample the sidewall for comparative analysis of species distribution in the vertical axial direction.

In an exemplary embodiment, the detection windows comprise a first pair of windows 43 disposed on the radial sidewalls of the fourth conduit 4 and adapted to perform atomic resonance absorption spectroscopy, laser absorption spectroscopy, high-speed imaging, and the like.

In an exemplary embodiment, the inspection windows further comprise a second pair of windows 41 disposed on the radial sidewall of the fourth conduit 4, adapted to perform schlieren imaging, interferometry, and high-speed imaging in cooperation with the first pair of windows 43 to construct a three-dimensional flame shape.

In such an embodiment, the schlieren method diagnoses through the second pair of windows 41 downstream of the fourth tube 4, the inline laser diagnoses through the first pair of windows 43, and a photomultiplier tube (PMT) test diagnoses through the window 44 of the third end cap such that the sampling forms both side wall face sampling and end wall face sampling.

FIG. 2 is a schematic view of the exemplary embodiment of FIG. 1 with the shut-off assembly in a first position. FIG. 3 is a schematic view of the exemplary embodiment of the shutoff assembly shown in FIG. 1 in a second position.

According to the embodiment of the present disclosure, as shown in fig. 1 to 3, the actuating assembly is configured to apply an adjustable pressure to the stopping assembly 61, the stopping assembly 61 is maintained at the first position in a state where the pressure applied by the actuating assembly is greater than or equal to the pressure applied by the first gas and the second gas to the stopping assembly 61, and the stopping assembly 61 is moved from the first position to the second position in a state where the pressure applied by the actuating assembly is less than the pressure applied by the first gas and the second gas to the stopping assembly 61.

According to an embodiment of the present disclosure, as shown in fig. 1 to 3, the cut-off assembly 61 includes a fixed part and a multi-stage moving part. The fixing portion is provided on the first pipe 1 and/or the second pipe 2. The one-level moving part of multistage moving part is located in the fixed part in the cover, and other moving part cup joints in adjacent moving part step by step, and under the state of first position, at least one-level moving part stretches into in first pipeline 1, in order to seal first pipeline 1 and second pipeline 2, and under the state of second position, every stage moving part all breaks away from with first pipeline 1, in order to switch on first pipeline 1 and second pipeline 2.

In such an embodiment, the actuating assembly is adapted to apply a pressure to the shut-off assembly 61 in a direction opposite to the pressure applied by the first and second gases. The multistage moving part moves to a side close to the pressure applying component in sequence under the condition that the pressure is smaller than the pressure applied by the first gas and the second gas. At the initial stage of the moving process, the moving part close to the fixed part drives the next-stage moving part to move synchronously, so that the whole multi-stage moving part has a larger stress area and is quicker to accelerate. In the middle and later stages of the moving process, when the first-stage moving part moves to the limited position, the next-stage moving part moves continuously away from the first-stage moving part, and the mass of the subsequent multi-stage moving part is gradually reduced, so that the moving part extending into the first pipeline 1 is accelerated more, and the first-stage moving part is separated from the first pipeline 1 within a very small time (including but not limited to 1.56 milliseconds) so as to realize the conduction of the first pipeline 1 and the second pipeline 2, wherein in the projection in the axial direction, the bottom surface of the first bulge passes through the edge of the first pipeline 1 (such as the lower end part of the second pipeline 2 shown in fig. 3) to the vertex of the first bulge passes through the edge of the first pipeline 1. In this way, the formation of the shock wave is facilitated.

According to an embodiment of the present disclosure, as shown in fig. 1 to 3, the fixing portion includes a first end cap 613, and the first end cap 613 is disposed on the second pipe 2.

In an exemplary embodiment, the outlet side of the second pipe 2 is configured as a cylindrical joint.

In detail, the first end cap 613 is disposed on a cylindrical joint, and an extending direction of an axis of the first end cap 613 and an axis of the joint coincides.

According to an embodiment of the present disclosure, as shown in fig. 1 to 3, the multistage moving part includes a first sleeve 611 and a first piston 612. The first sleeve 611 is sleeved in the first end cap 613, and is configured to move a first end of the first sleeve 611 facing the second pipe 2 between a third position protruding from the first end cap 613 and a fourth position retracted into the first end cap 613. The second end of the first piston 612 is sleeved in the first sleeve 611, the third end of the first piston 612, which is opposite to the second end, is configured to move between the first position and the second position, the second end extends outward in the circumferential direction to form a first flange, when the first sleeve 611 is located at the third position, the first flange abuts against the facing end surface of the first sleeve 611 to hold the first piston 612 at the first position, when the first sleeve 611 moves from the third position to the fourth position, the first piston 612 and the first sleeve 611 move synchronously, when the first sleeve 611 is located at the fourth position, the first flange is separated from the first sleeve 611, and the first piston 612 moves to the second position.

In an exemplary embodiment, with the first sleeve 611 in the third position, the first end of the first sleeve 611 abuts against an opposite end face of the first pipe 1.

In an exemplary embodiment, the outer diameter of the third end of the first piston 612 is substantially the same as the inner diameter of the first tube 1.

In such an embodiment, the first sleeve 611 and the first piston 612 are fitted to close the first tube 1 and the second tube 2. This is favorable to promoting the gas tightness between first pipeline 1 and the second pipeline 2, can be more effectual prevent that the second gas from leaking to in the first pipeline 1.

According to the embodiment of the present disclosure, a radial middle of an end of the third end of the first piston 612 extends to the first direction to form a first protrusion, and an arc-shaped surface is formed between the first protrusion and an outer edge of the third end to guide the second gas to enter the first pipe 1 along the arc-shaped surface.

In such an embodiment, it is beneficial to guide the second gas so that the second gas enters the first pipeline 1 in a direction approximately tangential to the arc-shaped surface, and the second gas can be effectively prevented from being reflected in a direction orthogonal to the first pipeline 1.

According to the embodiment of the disclosure, as shown in fig. 1 to 3, a plurality of first air guide holes 6131 are circumferentially arranged at one axial position on the sidewall of the first end cover 613, a plurality of second air guide holes 6132 are circumferentially arranged at another axial position on the sidewall of the first end cover 613, and a plurality of third air guide holes 6111 are circumferentially arranged at an axial position on the sidewall of the first sleeve 611 corresponding to the second air guide holes 6132. The first sleeve 611 and the first end cap 613 define a first chamber 64 therebetween, the first chamber 64 communicates with the second conduit 2 through a first gas vent 6131 adapted to introduce a second gas into the first chamber 64 to apply a portion of the first pressure to the first sleeve 611, the first piston 612 defines a second chamber 65 with the first sleeve 611, and the second gas vent 6132 communicates with a third gas vent 6111 in a state where the first sleeve 611 is in the fourth position, adapted to introduce the second gas into the second chamber 65 to apply a portion of the first pressure to the first piston 612.

In such an embodiment, during the process of moving the first sleeve 611 from the third position to the fourth position, the first pressure provided by the second gas acts on the first sleeve 611, and the first pressure provided by the first gas acts on the first piston 612, so that the first sleeve 611 and the first piston 612 have a larger force-bearing area, which is beneficial to accelerating the first sleeve 611 and the first piston 612. After the first piston 612 has a certain speed, the first sleeve 611 is limited to the fourth position, and in this state, the second gas is conducted through the second gas hole 6132 and the third gas hole 6111, so that the first pressure provided by the first gas only acts on the first piston 612 to further accelerate the first piston 612.

According to an embodiment of the present disclosure, as shown in fig. 1 to 3, the actuating assembly includes a pressing portion 62 and a releasing portion 63. The pressure applying portion 62 is disposed on the first end cap 613 and is adapted to be filled with a third gas to apply a second pressure to the first sleeve 611 and the first piston 612 by the third gas. The releasing portion 63 is provided on the pressing portion 62, and is configured to move between a fifth position at which the pressing portion 62 is closed and a sixth position at which the pressing portion 62 is opened. In the state where the releasing portion 63 is at the fifth position, the third gas is enclosed among the pressing portion 62, the first sleeve 611, and the first piston 612 to apply a second pressure, which is greater than the first pressure, to the first sleeve 611 and the first piston 612, and in the state where the releasing portion 63 is at the sixth position, the third gas is discharged to the air atmosphere so that the second pressure is less than the first pressure.

In an exemplary embodiment, the third gas includes, but is not limited to, a mixture of one or more of oxygen, nitrogen, air, carbon monoxide, carbon dioxide, nitric oxide, and water vapor.

In such an embodiment, the pressing portion 62 is adapted to be filled with a third gas, and the third gas is sealed in the sealed space formed by the pressing portion 62, the first sleeve 611 and the first piston 612 to provide a second pressure to the first sleeve 611 and the first piston 612. In a state where the to-be-released portion 63 is moved to the sixth position, the pressure applying portion 62 is conducted to the outside air environment, and the second pressure is instantaneously close to zero. Thus, the first sleeve 611 and the first piston 612 can be relatively rapidly accelerated toward the releasing portion 63 by the first pressure.

According to an embodiment of the present disclosure, as shown in fig. 1 to 3, the pressure applying portion 62 includes a second sleeve 621, a second end cap 623, and a second piston 622. The fourth end 6212 of the second sleeve 621 facing the first end cap 613 is sleeved in the first end cap 613, and the sidewall of the second sleeve 621 is circumferentially provided with a plurality of first exhaust holes 6211 adapted to communicate the inside of the second sleeve 621 with the external gas environment. The second end cap 623 is disposed at an end of the second sleeve 621 opposite to the first end cap 613, and the third chamber 66 is defined between the second end cap 623, the second sleeve 621, the first end cap 613, the first sleeve 611 and the first piston 612. The second piston 622 is sleeved in the second sleeve 621 and configured to move between a seventh position where the first exhaust hole 6211 is closed and an eighth position where the first exhaust hole 6211 is opened, the third chamber 66 is divided into a first sub-chamber and a second sub-chamber by the second piston 622, and the second piston 622 is provided with a pressure equalizing hole 6221 adapted to communicate the first sub-chamber and the second sub-chamber.

In an exemplary embodiment, as shown in fig. 2 and 3, the middle portion of the second sleeve 621 is configured as a cylinder-like portion, and the end of the second sleeve 621 that faces away from the fourth end 6212 is configured as a truncated cone-like portion.

In detail, the cylindrical portion is provided with a first exhaust hole 6211.

Further, in a state where the second piston 622 is at the seventh position, the second piston 622 coincides with the first exhaust hole 6211 in a projection in the radial direction to seal the first exhaust hole 6211. When the second piston 622 is in the eighth position, the second piston 622 retracts into the truncated cone-like portion, and the second piston 622 and the first exhaust hole 6211 are displaced, so that the first exhaust hole 6211 is communicated with the external air environment, and the third gas can be rapidly exhausted to the external air environment.

According to an embodiment of the present disclosure, as shown in fig. 2 and 3, an end of the fourth end 6212 facing the first sleeve 611 extends in a direction of the first sleeve 611 to form a first stopper 6213, and an inner diameter of the first stopper 6213 is greater than or equal to an outer diameter of the first piston 612, and is adapted to restrict the first sleeve 611 to the fourth position and allow the first piston 612 to pass through until the first piston 612 moves to the second position abutting against the fourth end 6212.

In an exemplary embodiment, an annular gap is formed between the outer edge of the first stopper 6213 and the inner edge of the first end cap 613, and the width of the gap is substantially the same as the thickness of the first sleeve 611.

In detail, an inner edge of the first stopper 6213 has substantially the same outer diameter as the second end of the first piston 612.

Further, the inner edge of the first stopper portion 6213 is configured as an inwardly projecting stepped portion.

In such an embodiment, in a state where the first sleeve 611 moves to the fourth position, the first sleeve 611 fits in the gap, and the first stopper portion 6213 abuts against the first sleeve 611, so that the first sleeve 611 is restricted to the fourth position. At this time, the first piston 612 may continue to pass through the inner edge of the first stopper 6213 until the first piston 612 abuts against the stepped portion to restrict the first piston 612 to the second position.

In one exemplary embodiment, the second sleeve 621 is provided with a damping vent hole 6214, and a vent end of the damping vent hole 6214 is provided at a position opposite to the gap of the second endcap 623.

In such an embodiment, since the first sleeve 611 blocks the gap in the state where the first sleeve 611 is inserted into the gap, most of the gas in the original gap is discharged only through the damping gas discharge hole 6214, and the movement of the first sleeve 611 from the third position to the fourth position is blocked, so that the first sleeve 611 is damped. This cushions the first sleeve 611 to reduce the impact of the first sleeve 611 moving to the fourth position.

According to the embodiment of the present disclosure, as shown in fig. 2 and 3, the second end cap 623 is provided with an air inlet hole 6231 communicated with the third chamber 66, and adapted to introduce the third gas into the third chamber 66 through the air inlet hole 6231, and a first valve is disposed in the air inlet hole 6231 and adapted to open or close the air inlet hole 6231.

In an exemplary embodiment, the first valve includes, but is not limited to, a solenoid valve.

According to an embodiment of the present disclosure, as shown in fig. 2 and 3, at least one fourth air-guide hole 6232 is axially provided in the second endcap 623. The release portion 63 includes a third sleeve 631 and a third piston. A third sleeve 631 is disposed on the second end cap 623, the third sleeve 631 and the second end cap 623 defining a fourth chamber 67 therebetween. The third piston is sleeved in the third sleeve 631 and configured to move between a fifth position where the fourth air-guide hole 6232 is closed and a sixth position where the fourth air-guide hole 6232 is opened. The third piston divides the fourth chamber 67 into a third sub-chamber and a fourth sub-chamber, a second exhaust hole 6311 is formed on the sidewall of the third sleeve 631 located in the third sub-chamber, a third exhaust hole 6312 is formed on the sidewall of the third sleeve 631 located in the fourth sub-chamber, and second valves are disposed in the second exhaust hole 6311 and the third exhaust hole 6312, and are adapted to connect or disconnect the second exhaust hole 6311 and/or the third exhaust hole 6312 to the external air environment.

In an exemplary embodiment, the second valve includes, but is not limited to, a solenoid valve.

In an exemplary embodiment, a plurality of fourth gas holes 6232 are provided in the second endcap 623.

In detail, the plurality of fourth air holes 6232 provided in the second endcap 623 is symmetrical with respect to the center.

In an exemplary embodiment, the end surface of the third piston facing the second end cap 623 is provided with a plurality of second protrusions corresponding to the positions of the fourth air holes 6232.

In detail, the number of the second protrusions coincides with the number of the fourth air-guide holes 6232.

Further, the second projection has a shape and a size corresponding to the fourth air-guide hole 6232. In a state where the third piston is in the fifth position, each second protrusion is fitted into the opposing fourth air-guide hole 6232 to close each fourth air-guide hole 6232.

In such an embodiment, the third piston and the second end cap 623 are engaged to provide a better sealing property for the fourth chamber 67.

According to an embodiment of the present disclosure, as shown in fig. 2 and 3, an inner surface of the sidewall of the third sleeve 631 extends radially inward to form a second stopper 6313 adapted to hold the third piston in the sixth position. When the third piston is at the sixth position, both the second exhaust hole 6311 and the third exhaust hole 6312 are in an open state in which the fourth chamber 67 is communicated with the outside air atmosphere.

In an exemplary embodiment, as shown in fig. 2, the first piston 612 is in the first position (the first piston 612 extends into the first pipe 1), the first end (upper end) of the first sleeve 611 is in the third position (extending from the first end cap 613 and abutting against the first pipe 1), and the second piston 622 is in the seventh position (upper part of the third chamber 66).

In this state, the third piston is in the fifth position (upper portion of the fourth chamber 67), and the fourth chamber 67 is filled with compressed gas and is in a sealed state. At this time, the sum of the pressure (P1) applied to the first piston 612 by the first gas and the pressure (P2) applied to the first sleeve 611 by the second gas is less than or equal to the sum of the pressure (P3) applied to the first piston 612 and the first sleeve 611 by the third gas and the frictional force (Pf) between the first sleeve 611 and the first end cap 613 and between the first sleeve 611 and the first piston 612.

After the second valve is turned on, as shown in fig. 3, under the action of P1 and P2, the compressed air in the fourth chamber 67 is discharged along the second gas discharge hole 6311 and the third gas discharge hole 6312, respectively, so that the pressure in the first sub-chamber of the third chamber 66 is reduced (since the second piston 622 is provided with the pressure equalizing hole 6221, the pressure in the second sub-chamber is also reduced but the reduction speed is slower than that in the first sub-chamber), so that the second piston 622 moves to the eighth position (the lower portion of the third chamber 66), and when the second piston 622 and the first gas discharge hole 6211 are dislocated, the third gas is rapidly discharged to the external air environment under the action of P1 and P2. At this time, the sum of P1 and P2 is greater than the sum of P3 and Pf, and the second gas sequentially enters the first chamber 64 and the second chamber 65 to move the first sleeve 611 to the fourth position and the first piston 612 to the second position until the first sleeve 611 is in the fourth position and the first piston 612 is in the second position.

The exemplary embodiment of the present invention further provides a sampling system, as shown in fig. 5, including a membrane-less shock tube and a gas chromatograph-mass spectrometer 7 connected to a sampling channel 45 of the membrane-less shock tube.

In an exemplary embodiment, the sampling system further includes a first gas mixing tank 8 adapted to mix at least two of the gases including, but not limited to, oxygen, nitrogen, air, carbon monoxide, carbon dioxide, nitric oxide, and water vapor to form a first gas.

In an exemplary embodiment, the sampling system further includes a second gas mixing tank 10 adapted to mix at least two of one or more gases including, but not limited to, acetylene, hydrogen, oxygen, nitrogen, argon, helium, and other inert gases to form a second gas.

In an exemplary embodiment, the sampling system further comprises a vacuum pump 9, disposed between the first gas mixing tank 8 and the first pipeline 1 and/or between the second gas mixing tank 10 and the second pipeline 2, adapted to input or output the first gas into or out of the first pipeline 1 and the second gas into or out of the second pipeline 2.

It will be understood by those skilled in the art that various embodiments of the present disclosure and/or features recited in the claims may be combined in several ways and/or combinations, even if such combinations or combinations are not explicitly recited in the present disclosure. In particular, features recited in various embodiments of the disclosure and/or in the claims may be combined and/or coupled in several ways without departing from the spirit and teachings of the disclosure. All such combinations and/or associations are within the scope of the present disclosure.

The above embodiments are further described in detail for illustrating the purpose, technical solutions and advantages of the present invention, and it should be understood that the above embodiments are only examples of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A membraneless shock tube, comprising:

a first duct (1) extending in a first direction, suitable for being filled with a first gas;

-at least one second duct (2) extending along a second direction orthogonal to said first direction, suitable for being filled with a second gas and communicating with said first duct (1);

a shut-off mechanism (6) comprising:

a shut-off assembly (61), at least a portion of the shut-off assembly (61) being configured to move in a first direction between a first position projecting into the first conduit (1) and a second position disengaged from the first conduit (1); and

an actuating assembly connected to the shut-off assembly (61) and adapted to hold the shut-off assembly (61) in or out of the first position;

wherein, when the cut-off component (61) is at the first position, the first pipeline (1) and the second pipeline (2) are closed, and when the cut-off component (61) is at the second position, the first pipeline (1) and the second pipeline (2) are communicated to form shock waves in the first pipeline (1) based on the pressure difference of the second gas and the first gas.

2. The membraneless shock tube of claim 1, further comprising:

the third pipeline (3) is arranged at the end part of the first pipeline (1) opposite to the second pipeline (2) and communicated with the first pipeline (1); and

the fourth pipeline (4) is arranged at the end part of the third pipeline (3) opposite to the first pipeline (1) and is communicated with the third pipeline (3);

preferably, the inner diameter of the third pipeline (3) is gradually reduced from the end close to the first pipeline (1) to the end far away from the first pipeline (1);

preferably, a detection window and a sampling channel (45) are arranged in the fourth pipeline (4).

3. The membrane-less shock tube of claim 1 or 2, wherein the actuation assembly is configured to apply an adjustable pressure to the shut-off assembly (61), the shut-off assembly (61) being maintained in the first position in a state where the pressure applied by the actuation assembly is greater than or equal to the pressure applied by the first and second gases to the shut-off assembly (61), the shut-off assembly (61) being moved from the first position to the second position in a state where the pressure applied by the actuation assembly is less than the pressure applied by the first and second gases to the shut-off assembly (61).

4. The membraneless shock tube according to claim 1 or 2, wherein the shut-off assembly (61) comprises:

a fixing portion provided on the first duct (1) and/or the second duct (2); and

the multi-stage moving part is sleeved in the fixed part, the other moving parts are sleeved in the adjacent moving parts stage by stage, at least one stage of moving part extends into the first pipeline (1) to seal the first pipeline (1) and the second pipeline (2) in the state of the first position, and each stage of moving part is separated from the first pipeline (1) to conduct the first pipeline (1) and the second pipeline (2) in the state of the second position;

preferably, the fixing portion comprises a first end cap (613), the first end cap (613) being disposed on the second pipe (2);

preferably, the plurality of stages of moving parts include:

a first sleeve (611) housed in said first end cap (613), the first end of the first sleeve (611) being configured to face said second duct (2) moving between a third position, in which it protrudes from said first end cap (613), and a fourth position, in which it is retracted inside the first end cap (613); and

a first piston (612), a second end of the first piston (612) being sleeved in the first sleeve (611), a third end of the first piston (612), opposite to the second end, being configured to move between the first position and a second position, the second end extending circumferentially outward to form a first flange, the first flange abutting against an opposite end surface of the first sleeve (611) in a state where the first sleeve (611) is in the third position to hold the first piston (612) in the first position, the first sleeve (611) moving from the third position to a fourth position, the first piston (612) moving synchronously with the first sleeve (611), the first sleeve (611) remaining in the fourth position, the first flange disengaging from the first sleeve (611), and the first piston (612) moving to the second position;

preferably, a radial middle part of the end part of the third end extends towards the first direction to form a first protruding part, and an arc-shaped surface is formed between the first protruding part and the outer edge of the third end so as to guide the second gas to enter the first pipeline (1) along the arc-shaped surface.

5. The membraneless shock tube according to claim 4, wherein the sidewall of the first end cap (613) is circumferentially provided with a plurality of first air-guide holes (6131) at one axial position, the sidewall of the first end cap (613) is circumferentially provided with a plurality of second air-guide holes (6132) at another axial position, and the sidewall of the first sleeve (611) is circumferentially provided with a plurality of third air-guide holes (6111) at an axial position corresponding to the second air-guide holes (6132);

wherein the first sleeve (611) and the first end cap (613) define between them a first chamber (64), the first chamber (64) communicating with the second duct (2) through the first gas vent (6131), adapted to introduce the second gas into the first chamber (64) to exert a portion of the first pressure on the first sleeve (611), the first piston (612) and the first sleeve (611) defining between them a second chamber (65), the second gas vent (6132) communicating with the third gas vent (6111) in the state in which the first sleeve (611) is in the fourth position, adapted to introduce the second gas into the second chamber (65) to exert a portion of the first pressure on the first piston (612).

6. The membraneless shock tube of claim 5, wherein the actuation assembly comprises:

a pressure applying part (62) disposed on the first end cap (613) and adapted to be filled with a third gas to apply a second pressure to the first sleeve (611) and the first piston (612) by the third gas; and

a releasing portion (63) provided on the pressing portion (62) and configured to move between a fifth position where the pressing portion (62) is closed and a sixth position where the pressing portion (62) is opened;

wherein the third gas is enclosed between the pressure applying portion (62), the first sleeve (611), and the first piston (612) to apply a second pressure higher than the first pressure to the first sleeve (611) and the first piston (612) in a state where the releasing portion (63) is at the fifth position, and the third gas is exhausted to the air atmosphere in a state where the releasing portion (63) is at the sixth position to make the second pressure lower than the first pressure.

7. The membrane-less shock tube according to claim 6, wherein the pressing portion (62) includes:

a second sleeve (621), a fourth end (6212) of the second sleeve (621) facing the first end cap (613) is sleeved in the first end cap (613), and a plurality of first exhaust holes (6211) are circumferentially arranged on a side wall of the second sleeve (621), so as to conduct the inside of the second sleeve (621) with the external gas environment;

a second end cap (623) disposed at an end of the second sleeve (621) opposite to the first end cap (613), the second end cap (623), the second sleeve (621), the first end cap (613), the first sleeve (611), and the first piston (612) defining a third chamber (66) therebetween;

the second piston (622) is sleeved in the second sleeve (621) and is configured to move between a seventh position for closing the first exhaust hole (6211) and an eighth position for opening the first exhaust hole (6211), the third chamber (66) is divided into a first sub-chamber and a second sub-chamber by the second piston (622), and the second piston (622) is provided with a pressure equalizing hole (6221) suitable for communicating the first sub-chamber with the second sub-chamber;

preferably, the end of the fourth end (6212) facing the first sleeve (611) extends in the direction of the first sleeve (611) to form a first stopper (6213), and the inner diameter of the first stopper (6213) is greater than or equal to the outer diameter of the first piston (612), adapted to limit the first sleeve (611) to the fourth position and allow the first piston (612) to pass through until the first piston (612) moves to a second position abutting against the fourth end (6212);

preferably, the second end cover (623) is provided with an air inlet hole (6231) communicated with the third chamber (66), the third chamber (66) is filled with the third gas through the air inlet hole (6231), and a first valve is arranged in the air inlet hole (6231) and is suitable for conducting or closing the air inlet hole (6231).

8. The membraneless shock tube according to claim 7, wherein the second end cap (623) is provided with at least one fourth gas-guiding hole (6232) in the axial direction, and the releasing portion (63) comprises:

a third sleeve (631) disposed over the second end cap (623), the third sleeve (631) and the second end cap (623) defining a fourth chamber (67) therebetween; and

a third piston, which is sleeved in the third sleeve (631) and is configured to move between a fifth position where the fourth air vent (6232) is closed and a sixth position where the fourth air vent (6232) is opened;

wherein, the third piston will fourth chamber (67) is separated for third subchamber and fourth subchamber, is located form second exhaust hole (6311) on the lateral wall of third sleeve (631) in the third subchamber, is located form third exhaust hole (6312) on the lateral wall of third sleeve (631) in the fourth subchamber, all be provided with the second valve in second exhaust hole (6311) and the third exhaust hole (6312), be applicable to with second exhaust hole (6311) and/or third exhaust hole (6312) with outside air circumstance switches on or closes.

9. The membraneless shock tube according to claim 8, wherein the inner surface of the sidewall of the third sleeve (631) extends radially inward forming a second stop (6313) adapted to retain the third piston in the sixth position;

wherein, in a state where the third piston is in the sixth position, the second exhaust hole (6311) and the third exhaust hole (6312) are both in an open state that communicates the fourth chamber (67) with the outside air environment.

10. A sampling system, comprising:

the membraneless shock tube of any one of claims 1-9; and

and the gas chromatography-mass spectrometer (7) is communicated with the sampling channel (45) of the membrane-free shock tube.