A system and method for measuring the opening characteristics of a quick-opening valve based on PDV

Abstract

The application provides a system and method for measuring the opening characteristics of a quick-opening valve based on PDV, which is used to solve the problem that the high-pressure and high-speed airflow during the opening of the quick-opening valve interferes with and destroys the contact type test element, resulting in the reduction of the measurement accuracy and the short service life of the test element. The application mainly uses the PDV system to non-contact measure the movement of the valve core in the quick-opening valve, discharges the air outside through the exhaust cavity in the quick-opening valve, and makes the valve core move under the action of the air pressure difference. The laser provided by the laser on the optical fiber probe is incident on the central position of the valve core through the light transmission hole. The incident laser is reflected and transmitted to the optical fiber probe. Then, the optical fiber probe transmits the collected valve core movement information to the laser. The oscilloscope connected with the laser collects and records the valve core opening movement information. The application can effectively avoid the damage of the high-pressure and high-speed airflow generated during the opening movement of the quick-opening valve to the measurement system, prolong the service life of the measurement system, and improve the measurement accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of valve opening characteristics measuring device and method, specifically to a kind of system and method based on PDV measurement fast opening valve opening characteristics. BACKGROUND

[0002] Fast opening valve has the advantages such as quick action, reliable operation, remote control, and is widely used in the switch control of pipeline system, and the driving control of strong impact simulation device such as shock tube, light gas gun, combustion wind tunnel.The measurement of fast opening valve opening characteristics is the main content and method of fast opening valve performance research.

[0003] At present, the published literature on fast opening valve opening characteristic measurement basically uses accelerometer or displacement sensor and other conventional contact type test elements, and then the valve speed, displacement is obtained by integration or differentiation.Because the opening speed of fast opening valve is fast, strong drag force or shear force will be generated on the lead wire of test element during the movement of valve core.In addition, when the driving source is high pressure medium, strong interference and impact will be generated on the test element during the opening action of fast opening valve, thereby affecting the measurement accuracy and service life of test element, and even directly destroying the structure of test element, leading to unable to obtain experimental data.Therefore, it is necessary to find a new method for measuring the opening characteristics of fast opening valve.

[0004] Photonic Doppler velocimetry (PDV) is a new type of laser interferometric velocimetry technology, which has the advantages of high measurement accuracy and fast dynamic response, and is mainly composed of laser and optical fiber probe, and is widely used in the measurement of detonation wave, shock wave and other short-time high-speed motion.But there is no related report on the application of photonic Doppler velocimetry (PDV) technology in the test research of fast opening valve opening characteristics. SUMMARY

[0005] The purpose of the present application is to solve the technical problems that the lead wire of test element will generate strong drag force or shear force during the movement of valve core when fast opening valve opens, and when the driving source is high pressure medium, high pressure and high speed fluid will generate strong interference and impact on contact type test element, resulting in low measurement accuracy and short service life of test element, and to provide a system and method for measuring the opening characteristics of fast opening valve based on PDV.

[0006] To achieve the above-mentioned purpose of the present application, the technical solution provided by the present application is:

[0007] A system for measuring the opening characteristics of a quick-opening valve based on PDV, comprising a quick-opening valve, the quick-opening valve comprising a valve body, a high-pressure air chamber arranged in the valve body, a cylinder located in the high-pressure air chamber, a valve core, an overflow valve arranged at the bottom of the cylinder for communicating the exhaust cavity in the cylinder with the high-pressure air chamber, a valve seat arranged at the front end of the valve body, and an inlet / exhaust pipe arranged on the valve body and communicating with the cylinder, characterized in that it further comprises a probe fixing unit, a protection unit, a valve core movement measuring unit and a pressure monitoring unit.

[0008] The probe fixing unit comprises a fiber probe mounting flange, connecting screws and a pipe body, the fiber probe mounting flange is fixedly connected with the valve seat through at least two connecting screws uniformly arranged along the circumference thereof, and the fiber probe mounting flange is mounted on the pipe body.

[0009] The valve core movement measuring unit comprises a fiber probe and a laser, the fiber probe is connected with the laser through a measuring cable, and the laser is connected with a first oscilloscope and a second oscilloscope in sequence through a measuring cable; the fiber probe is arranged on the fiber probe mounting flange at a position coaxial with the valve core; the fiber probe is used for collecting the movement information of the valve core, i.e., the movement speed and displacement information of the valve core; the fiber probe is arranged on the center of the fiber probe mounting flange at a position coaxial with the valve core.

[0010] The protection unit comprises a protective cover arranged on the fiber probe mounting flange and located between the valve core and the fiber probe, and the protective cover is provided with a light-transmitting hole coaxial with the fiber probe and the valve core; the fiber probe makes the laser emitted by the laser enter the central position of the valve core through the light-transmitting hole.

[0011] The pressure monitoring unit comprises a first pressure sensor arranged on the inlet / exhaust pipe and a second pressure sensor arranged on the valve body, and the first pressure sensor and the second pressure sensor are connected to the second oscilloscope through a measuring cable.

[0012] Further, the fiber probe is fixedly arranged on the fiber probe mounting flange at a position coaxial with the valve core through a probe mounting seat, the probe mounting seat is provided with a mounting hole, the hole diameter of the mounting hole is greater than the outer diameter of the fiber probe, the fiber probe is fixed in the mounting hole of the probe mounting seat through an adjusting screw radially mounted on the probe mounting seat, and the adjusting screw is used for adjusting the coaxiality of the fiber probe and the valve core.

[0013] Further, the adjusting screw is four, which are uniformly arranged along the circumference of the fiber probe. The four adjusting screws can adjust the fiber probe up, down, left and right, so that the fiber probe is located at a coaxial position with the valve core, and the laser echo loss is reduced.

[0014] Further, the connecting screw is 4, and is uniformly arranged along the circumference of the fiber probe mounting flange; the stability of the valve body and the fiber probe mounting flange is ensured by the fixing connection of the valve seat at the front end of the valve body and the fiber probe mounting flange by the connecting screw. According to actual needs, 6 connecting screws can also be arranged, wherein the advantage of arranging 4 connecting screws is that the installation structure is relatively simple and convenient, and the advantage of arranging 6 connecting screws is that the connection between the fiber probe mounting flange and the valve seat at the front end of the valve body is more stable, and the impact of the high-speed high-pressure gas on the measurement opening characteristic system of the quick-opening valve when rapidly releasing is reduced.

[0015] Further, the fiber probe mounting flange is connected to the pipe body by screwing. Since the pipe body and the quick-opening valve are both fixed to the support base in the vertical direction, the coaxiality between the two is good. Therefore, the fiber probe mounting flange is connected to the pipe body by screwing, which can effectively ensure the coaxiality between the fiber probe and the valve core, reduce the echo loss of the PDV system, and thus improve the measurement accuracy of the opening characteristic of the quick-opening valve.

[0016] Further, a nut is arranged on the connecting screw, so that the quick-opening valve is fixed to the fiber probe mounting flange and the pipe body in the axial direction. The influence of the high-pressure high-speed airflow on the quick-opening valve structure during the opening movement of the valve core can be reduced.

[0017] Further, the light-transmitting hole is in the shape of a truncated cone, with the large-diameter end opposite the fiber probe and the small-diameter end opposite the valve core.

[0018] The light-transmitting hole can also be an optical light-transmitting piece. Since the laser will produce a certain refraction angle when it is incident on the valve core through the optical light-transmitting piece, the measurement accuracy is affected, and therefore the light-transmitting hole is preferably used.

[0019] Meanwhile, the application also provides a method for measuring the opening characteristic of a quick-opening valve based on PDV, which adopts the above-mentioned system for measuring the opening characteristic of a quick-opening valve based on PDV, and the special feature thereof lies in comprising the following steps:

[0020] Step 1: Adjust the valve core movement measurement unit, the fiber probe and the light-transmitting hole on the protection unit to the coaxial position of the valve core in the quick-opening valve, so that the laser provided by the laser device is incident on the central position of the valve core through the light-transmitting hole.

[0021] Step 2: Fill the high-pressure gas into the exhaust cavity in the cylinder through the inlet / exhaust pipe, drive the piston in the cylinder to move the valve core to the side close to the valve seat, and close the valve core; the high-pressure gas in the exhaust cavity flows into the high-pressure chamber through the overflow valve, and when the gas pressure in the high-pressure chamber rises to a specified value, stop filling gas.

[0022] Step three, the high pressure gas in the exhaust cavity is released through the inlet / exhaust pipe, so that the gas pressure in the exhaust cavity is reduced, when the gas pressure in the exhaust cavity is reduced to a state that can make the valve core open, the piston in the cylinder drives the valve core to start moving, and the valve core opens; the high pressure gas in the high pressure chamber rushes out, so that the gas pressure in the high pressure chamber starts to drop;

[0023] Step four, the gas pressure signals in the exhaust cavity and the high pressure chamber are collected through the first pressure sensor on the inlet / exhaust pipe and the second pressure sensor on the valve body respectively, and the collected gas pressure signals in the exhaust cavity and the high pressure chamber are transmitted to the second oscilloscope through the measurement cable, so that the gas pressure change data in the exhaust cavity and the high pressure chamber are obtained and saved;

[0024] Step five, the falling edge of the gas pressure signal in the high pressure chamber collected by the second oscilloscope is used as the negative delay trigger signal of the first oscilloscope, the first oscilloscope starts recording, the optical fiber probe transmits the collected valve core movement data to the first oscilloscope through the laser, and the valve core opening movement speed and displacement curve are obtained through data processing software processing the valve core movement signal recorded by the first oscilloscope, so that the opening characteristic of the quick opening valve is measured.

[0025] Further, the steps one and two further comprise the following steps:

[0026] The coaxial position of the optical fiber probe, the light transmission hole and the valve core is verified by measuring the return loss of the optical fiber probe to the central position of the valve core, and if the return loss is greater than the verification value, the installation position of the optical fiber probe is adjusted through the adjusting screw on the probe mounting seat, so that the optical fiber probe, the light transmission hole and the valve core are in the coaxial position.

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] 【1】The optical fiber probe is installed on the optical fiber probe mounting flange to non-contact measure the valve core movement of the quick opening valve, so that the valve core opening movement speed and displacement are obtained, and the damage of the high pressure and high speed gas flow generated in the valve core opening movement process to the measurement system is avoided, and the service life of the measurement system is prolonged.

[0029] 【2】The gas pressure in the quick opening valve is monitored by the first pressure sensor and the second pressure sensor, the falling edge of the gas pressure signal of the high pressure chamber in the quick opening valve is used for negative delay trigger of the first oscilloscope recording the valve core movement information, and the collection of the zero point data of the valve core movement is effectively ensured.

[0030] 【3】The present application designs the optical fiber probe to be arranged in the central position of the optical fiber probe mounting flange plate and to be coaxial with the valve core, and then is fixed with the pipe body through the threaded connection, which can effectively guarantee the coaxiality between the optical fiber probe and the valve core, reduce the echo loss of the PDV system, and improve the measurement accuracy of the opening characteristics of the quick-opening valve.

[0031] 【4】The present application connects the valve seat and the optical fiber probe mounting flange plate with multiple connecting screws, which can effectively reduce the influence of the high-pressure gas rapid release on the quick-opening valve, and enhance the stability of the system.

[0032] 【5】The present application installs a protective cover between the optical fiber probe and the valve core, and the protective cover is provided with a light transmission hole, which can effectively avoid the impact and damage of high-pressure high-speed gas flow on the optical fiber probe, improve the service life of the optical fiber probe, and improve the measurement accuracy.

[0033] 【6】The present application fixes the optical fiber probe on the optical fiber probe mounting flange plate through the probe mounting seat, and sets adjusting screws on the probe mounting seat for fine adjustment of the installation position of the optical fiber probe, which further guarantees the coaxiality of the optical fiber probe and the valve core, and improves the measurement accuracy of the system. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a structure sectional view of the system embodiment of the present application for measuring the opening characteristics of the quick-opening valve based on PDV.

[0035] Figure 2 It is an enlarged view of I in the present application. Figure 1

[0036] Figure 3 It is a structure schematic view of the quick-opening valve in the embodiment of the present application.

[0037] Figure 4 It is an experimental waveform diagram of the opening movement of the quick-opening valve under the driving condition of 2.4MPa nitrogen gas in the embodiment of the present application, wherein (a) is a high-pressure gas chamber pressure-time history curve diagram, (b) is an exhaust cavity pressure-time history curve diagram, (c) is a valve core opening movement speed curve diagram, and (d) is a valve core opening movement displacement curve diagram.

[0038] Wherein, the reference signs are explained as follows:

[0039] ​1-fast opening valve; 2-protective cover; 3-optical fiber probe; 4-optical fiber probe mounting flange; 5-nut; 6-connecting screw; 7-tube body; 8-measuring optical cable; 9-laser; 10-first oscilloscope; 11-second oscilloscope; 12-first pressure sensor; 13-second pressure sensor; 14-measuring cable; 15-light transmission hole; 16-probe mounting seat; 161-adjusting screw; 17-valve body; 18-high pressure air chamber; 19-exhaust cavity; 20-cylinder; 21-valve core; 22-valve seat; 23-inlet / outlet pipe; 24-overflow valve; 25-piston. DETAILED DESCRIPTION

[0040] Example One

[0041] By Figure 1 It can be seen that the optical fiber probe 3 is fixedly installed at the center of the optical fiber probe mounting flange 4 through the probe mounting seat 16, the measuring optical cable 8 is led out from the sidewall opening of the tube body 7, then the measuring optical cable 8 is connected with the laser 9, and finally the optical fiber probe mounting flange 4 is fixedly connected on the tube body 7 through the threaded connection.

[0042] The optical fiber probe mounting flange 4 is fixedly connected with the valve seat 22 at the front end of the valve body 17 through two or more connecting screws 6. In this embodiment, six connecting screws 6 are used for connection according to the specific circumstances. The six connecting screws 6 are uniformly distributed along the circumference of the optical fiber probe mounting flange 4. Nuts 5 are installed at the connection between the optical fiber probe mounting flange 4 and the connecting screws 6, so that the fast opening valve 1 is fixedly connected on the optical fiber probe mounting flange 4 and the tube body 7, thereby reducing the influence of the recoil force generated by the rapid release of high pressure gas on the fast opening valve 1 during the opening movement of the valve core 21, and further ensuring the stability of the measuring system.

[0043] The optical fiber probe 3 is installed on the central position of the optical fiber probe mounting flange 4 through the probe mounting seat 16 and is arranged in the coaxial position with the valve core 21. The probe mounting seat 16 is provided with a mounting hole, the hole diameter of which is larger than the outer diameter of the optical fiber probe 3. The optical fiber probe 3 is fixed in the mounting hole of the probe mounting seat 16 through the adjusting screw 161 installed along the radial direction of the probe mounting seat 16. The probe mounting seat 16 is provided with the adjusting screw 161 for fine adjustment of the installation position of the optical fiber probe 3.

[0044] The four adjusting screws 161 on the probe mounting seat 16 are uniformly arranged along the circumference of the optical fiber probe 3 for fine adjustment of the installation position of the optical fiber probe 3. The four adjusting screws 161 can adjust the installation position of the optical fiber probe 3 up, down, left and right, so that the optical fiber probe 3 is in the coaxial position with the valve core 21, thereby reducing the laser echo loss.

[0045] The protective cover 2 is installed on the optical fiber probe mounting flange 4, and the protective cover 2 is arranged between the optical fiber probe 3 and the valve core 21. The central position of the protective cover 2 is provided with a light transmission hole 15. The light transmission hole 15, the optical fiber probe 3 and the valve core 21 are coaxially arranged. The light transmission hole 15 is in the shape of a truncated cone, and the large-diameter end of the light transmission hole 15 is opposite to the optical fiber probe, and the small-diameter end of the light transmission hole 15 is opposite to the valve core 21.

[0046] The return loss of the optical fiber probe 3 to the central position of the valve core 21 is measured. When the return loss is lower than 45 dB, it indicates that the performance of the optical fiber probe 3 and the measuring optical cable 8 is normal, the optical fiber probe 3 is coaxially arranged with the light transmission hole 15 and the valve core 21, and the measuring system can work normally. When the return loss is not lower than 45 dB, the quality of the optical fiber probe 3 and the measuring optical cable 8 is checked first. If there is a quality problem, the optical fiber probe 3 and the measuring optical cable 8 are replaced in time. If there is no quality problem, the installation position of the optical fiber probe 3 is adjusted up, down, left and right through the four adjusting screws 161 on the probe mounting seat 16, so that the optical fiber probe 3 is adjusted to be coaxial with the light transmission hole 15 and the valve core 21, and the measuring system can work normally.

[0047] The optical fiber probe 3 is connected with the laser 9 through the measuring optical cable 8. The laser 9 is connected with the first oscilloscope 10 and the second oscilloscope 11 in sequence through the measuring cable 14. The laser provided by the laser 9 is incident on the central position of the valve core 21 through the light transmission hole 15.

[0048] As shown in Figure 1 , Figure 2 , the first pressure sensor 12 and the second pressure sensor 13 are respectively installed on the side wall of the inlet / exhaust pipe 23 and the bottom end of the valve body 17, so as to measure the gas pressure in the exhaust cavity 19 in the cylinder 20 and the high-pressure gas chamber 18 in the valve body 17 of the quick-opening valve 1. The first pressure sensor 12 and the second pressure sensor 13 are connected to the second oscilloscope 11 through the measuring cable 14.

[0049] The falling edge of the gas pressure signal of the high-pressure gas chamber 18 collected by the second oscilloscope 11 is used to trigger the first oscilloscope 10 negatively.

[0050] After the debugging of the quick-opening valve opening characteristic measuring system is completed, high-pressure gas is filled into the exhaust cavity 19 in the cylinder 20 through the inlet / exhaust pipe 23. The piston 25 in the cylinder 20 drives the valve core 21 to move to the side close to the valve seat 22, and the valve core 21 is closed. The high-pressure gas in the exhaust cavity 19 flows into the high-pressure gas chamber 18 through the overflow valve 24. When the gas pressure in the high-pressure gas chamber 18 rises to a specified value, the filling of the gas into the exhaust cavity 19 and the high-pressure gas chamber 18 in the quick-opening valve 1 is stopped.

[0051] The high-pressure gas in the exhaust chamber 19 is released through the inlet / exhaust pipe 23, causing the gas pressure in the exhaust chamber 19 to drop. When the gas pressure in the exhaust chamber 19 drops to a state that allows the valve core 21 to open, the piston 25 in the cylinder 20 drives the valve core 21 to start moving, and the valve core 21 opens; the high-pressure gas in the high-pressure gas chamber 18 flows out, causing the gas pressure in the high-pressure gas chamber 18 to start dropping;

[0052] The gas pressure signals in the exhaust chamber 19 and the high-pressure gas chamber 18 are collected by the first pressure sensor 12 on the inlet / exhaust pipe 23 and the second pressure sensor 13 on the valve body 17, respectively. The collected gas pressure signals in the exhaust chamber 19 and the high-pressure gas chamber 18 are transmitted to the second oscilloscope 11 through the measuring cable 14, thereby obtaining and storing the gas pressure change data in the exhaust chamber 19 and the high-pressure gas chamber 18;

[0053] The falling edge of the gas pressure signal of the high-pressure gas chamber 18 collected by the second oscilloscope 11 is used as the negative delay trigger signal of the first oscilloscope 10. The first oscilloscope 10 starts recording, and the optical fiber probe 3 transmits the collected valve core 21 movement data to the first oscilloscope 10 through the laser 9. The valve core 21 opening movement signal recorded by the first oscilloscope 10 is processed by data processing software to obtain the speed and displacement curve of the valve core 21 opening movement, thereby completing the measurement of the opening characteristics of the quick-opening valve 1.

[0054] like Figure 3 As shown, high-pressure nitrogen is filled into the exhaust chamber 19 and the high-pressure gas chamber 18 through the inlet / exhaust pipe 23, so that the gas pressure in the exhaust chamber 19 and the high-pressure gas chamber 18 rises to the specified value of 2.4MPa, and the piston 25 in the cylinder 20 drives the valve core 21 to move toward the side close to the valve seat 22, and the valve core 21 is closed, and the charging of gas into the exhaust chamber 19 and the high-pressure gas chamber 18 in the quick-opening valve 1 is stopped; then, the gas is exhausted to the ambient air through the inlet / exhaust pipe 23. When the gas pressure in the exhaust chamber 19 drops to 0.54MPa, the valve core 21 is in a near-open state. As the gas pressure in the exhaust chamber 19 increases, the valve core 21 is in a near-open state. When the pressure of the gas in the exhaust chamber 19 further decreases, that is, when the pressure of the gas in the exhaust chamber 19 decreases to a state where the valve core 21 can be opened, the piston 25 in the cylinder 20 drives the valve core 21 to start moving to the left, and the valve core 21 opens; the high-pressure gas in the high-pressure gas chamber 18 flows outward, causing the gas pressure in the high-pressure gas chamber 18 to begin to decrease. The second oscilloscope 11 uses the falling edge of the gas pressure signal in the high-pressure gas chamber 18 as the negative delay trigger signal of the first oscilloscope 10, and the first oscilloscope 10 starts recording. The optical fiber probe 3 transmits the collected data on the movement of the valve core 21 to the first oscilloscope 10 via the laser 9;

[0055] Depend on Figure 3It can be seen that, the gas pressure change signal in the exhaust cavity 19 and the high-pressure chamber 18 collected by the second oscilloscope 11 is processed, and the time history curve of the gas pressure in the exhaust cavity 19 and the high-pressure chamber 18 can be obtained; the valve core 21 opening movement signal collected by the first oscilloscope 10 is processed by the data processing software, and the speed and displacement curve of the valve core 21 opening movement is obtained, so that the related data of the opening characteristic of the quick-opening valve 1 is obtained.

Claims

1. A system for measuring the opening characteristics of a quick-opening valve based on PDV, comprising a quick-opening valve (1), wherein the quick-opening valve (1) comprises a valve body (17), a high-pressure gas chamber (18) arranged in the valve body (17), a cylinder (20) located in the high-pressure gas chamber (18), a valve core (21), a relief valve (24) arranged at the bottom of the cylinder (20) for connecting an exhaust chamber (19) in the cylinder (20) with the high-pressure gas chamber (18), a valve seat (22) arranged at the front end of the valve body (17), and an inlet / exhaust pipe (23) arranged on the valve body (17) and connected to the cylinder (20), characterized in that: It also includes a probe fixing unit, a protection unit, a valve core movement measurement unit and a pressure monitoring unit; The probe fixing unit comprises an optical fiber probe mounting flange (4), a connecting screw (6) and a pipe body (7); the optical fiber probe mounting flange (4) is fixedly connected to the valve seat (22) via at least two connecting screws (6) uniformly arranged along its circumference; and the optical fiber probe mounting flange (4) is mounted on the pipe body (7); The valve core motion measurement unit comprises an optical fiber probe (3) and a laser (9), wherein the optical fiber probe (3) is connected to the laser (9) via a measuring optical cable (8), and the laser (9) is sequentially connected to a first oscilloscope (10) and a second oscilloscope (11) via a measuring cable (14); the optical fiber probe (3) is arranged on a position coaxial with the valve core (21) on an optical fiber probe mounting flange (4); and the optical fiber probe (3) is used to collect motion information of the valve core (21); The protection unit comprises a protection cover (2), which is arranged on a fiber optic probe mounting flange (4) and is located between a valve core (21) and a fiber optic probe (3). The protection cover (2) is provided with a light-transmitting hole (15) coaxial with the fiber optic probe (3) and the valve core (21); the fiber optic probe (3) transmits laser light emitted by a laser (9) to the center of the valve core (21) through the light-transmitting hole (15); The pressure monitoring unit comprises a first pressure sensor (12) arranged on an intake / exhaust pipe (23) and a second pressure sensor (13) arranged on a valve body (17); the first pressure sensor (12) and the second pressure sensor (13) are connected to a second oscilloscope (11) via a measuring cable (14).

2. The system for measuring the opening characteristics of a quick-opening valve based on PDV according to claim 1, characterized in that: The optical fiber probe (3) is fixedly mounted on the optical fiber probe mounting flange (4) at a position coaxial with the valve core (21) via a probe mounting seat (16); a mounting hole is provided on the probe mounting seat (16); the aperture of the mounting hole is larger than the outer diameter of the optical fiber probe (3); the optical fiber probe (3) is fixed in the mounting hole of the probe mounting seat (16) via an adjusting screw (161) radially mounted along the probe mounting seat (16); the adjusting screw (161) is used to adjust the coaxiality of the optical fiber probe (3) and the valve core (21).

3. The system for measuring the opening characteristics of a quick-opening valve based on PDV according to claim 2, characterized in that: There are four adjusting screws (161), which are evenly arranged along the circumference of the optical fiber probe (3).

4. A system for measuring the opening characteristics of a quick-opening valve based on PDV according to any one of claims 1 to 3, characterized in that: There are four connecting screws (6), which are evenly arranged along the circumference of the optical fiber probe mounting flange (4).

5. The system for measuring the opening characteristics of a quick-opening valve based on PDV according to claim 4, characterized in that: The optical fiber probe mounting flange (4) is connected to the pipe body (7) via threads.

6. The system for measuring the opening characteristics of a quick-opening valve based on PDV according to claim 5, characterized in that: It also includes a nut (5) which is mounted on a connecting screw (6) so that the quick-opening valve (1) is fixed axially to the optical fiber probe mounting flange (4) and the tube body (7).

7. The system for measuring the opening characteristics of a quick-opening valve based on PDV according to claim 6, characterized in that: The light-transmitting hole (15) is arranged in a truncated cone shape, with its large-diameter end facing the optical fiber probe (3) and its small-diameter end facing the valve core (21).

8. A method for measuring the opening characteristics of a quick-opening valve based on PDV, using the system for measuring the opening characteristics of a quick-opening valve based on PDV according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: The optical fiber probe (3) of the valve core movement measurement unit and the light-transmitting hole (15) on the protection unit are arranged in a coaxial position with the valve core (21) in the quick-opening valve (1), so that the laser light provided by the laser (9) to the optical fiber probe (3) is incident on the central position of the valve core (21) through the light-transmitting hole (15); Step 2: High-pressure gas is charged into the exhaust chamber (19) in the cylinder (20) through the inlet / exhaust pipe (23); the piston (25) in the cylinder (20) drives the valve core (21) to move toward the side close to the valve seat (22), and the valve core (21) is closed; the high-pressure gas in the exhaust chamber (19) flows into the high-pressure gas chamber (18) through the relief valve (24); when the gas pressure in the high-pressure gas chamber (18) rises to a specified value, the charging is stopped; Step 3: The high-pressure gas in the exhaust chamber (19) is released through the inlet / exhaust pipe (23), so that the gas pressure in the exhaust chamber (19) decreases. When the gas pressure in the exhaust chamber (19) decreases to a state where the valve core (21) can be opened, the piston (25) in the cylinder (20) drives the valve core (21) to start moving, and the valve core (21) opens; the high-pressure gas in the high-pressure gas chamber (18) flows outward, so that the gas pressure in the high-pressure gas chamber (18) begins to decrease; Step 4: The gas pressure signals in the exhaust chamber (19) and the high-pressure gas chamber (18) are collected respectively by the first pressure sensor (12) on the inlet / exhaust pipe (23) and the second pressure sensor (13) on the valve body (17), and the collected gas pressure signals in the exhaust chamber (19) and the high-pressure gas chamber (18) are transmitted to the second oscilloscope (11) through the measuring cable (14), thereby obtaining the gas pressure change data in the exhaust chamber (19) and the high-pressure gas chamber (18), and saving the data; Step 5: The falling edge of the gas pressure signal in the high-pressure gas chamber (18) collected by the second oscilloscope (11) is used as the negative delay trigger signal of the first oscilloscope (10). The first oscilloscope (10) starts recording. The optical fiber probe (3) transmits the collected valve core (21) motion data to the first oscilloscope (10) through the laser (9). The valve core (21) motion signal recorded by the first oscilloscope (10) is processed by data processing software to obtain the speed and displacement curve of the valve core (21) opening movement, thereby completing the measurement of the opening characteristics of the quick-opening valve (1).

9. The method for measuring the opening characteristics of a quick-opening valve based on PDV according to claim 8, characterized in that: The following steps are also included between step 1 and step 2: By measuring the laser return loss from the optical fiber probe (3) to the center of the valve core (21), it is checked whether the optical fiber probe (3), the light transmission hole (15), and the valve core (21) are in a coaxial position; if the return loss is greater than the test value, the installation position of the optical fiber probe (3) is adjusted by the adjustment screw (161) on the probe mounting seat (16) so that the optical fiber probe (3), the light transmission hole (15), and the valve core (21) are in a coaxial position.

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