CN207318397U - High-pressure hydrogen pipeline shock wave and static coupling measurement system - Google Patents

Abstract

The utility model discloses a high-pressure hydrogen pipeline shock wave and electrostatic coupling measurement system, which includes a hydrogen storage device, a nitrogen purging device, a release device, an electrostatic induction device, a pressure sensor array, a photoelectric sensor array, an electrostatic sensor array, a signal acquisition device and a computer. , the hydrogen storage device and the nitrogen purging device are respectively connected to the front end of the buffer tank through the intake pipe, and the end of the buffer tank is provided with an emptying device and a release device, and the discharge pipe is respectively provided with the electrostatic sensor array connected to the static detection platform And the pressure sensor array and the photoelectric sensor array connected to the signal acquisition device, the electrostatic detection platform and the signal acquisition device are connected to a computer, and the photographing device performs high-speed infrared photography. The beneficial effect of the utility model is that the coupling effects of two factors at different levels can be studied simultaneously in a set of devices; the experimental results are accurate, the experimental efficiency is improved, and the observation process is more complete.

Description

High pressure hydrogen pipeline shock wave and electrostatic coupling measurement system

technical field

The utility model relates to the technical field of hydrogen spontaneous combustion mechanism testing, in particular to a high-pressure hydrogen pipeline shock wave and electrostatic coupling measurement system.

Background technique

As a clean energy source, the use of hydrogen continues to expand. However, due to the wide explosion limit range of hydrogen itself and the low minimum ignition energy, once it leaks out of control, it will easily cause fire and explosion accidents. Different from other combustible gases, high-pressure hydrogen gas is very easy to spontaneously ignite after leakage. At present, the mechanism of high-pressure hydrogen leakage spontaneous combustion is mainly limited to the inverse Joule-Thomson effect, electrostatic ignition theory, diffusion ignition theory and other ignition theories, among which diffusion ignition theory is the most widely studied. Relevant domestic and foreign scientific research institutions represented by the University of Science and Technology of China have conducted a large number of experimental studies on the diffusion ignition theory, analyzed the compliance of the diffusion ignition theory under different shock wave intensities and different release environments, and proved the feasibility of the diffusion ignition theory. Relevant scientific research institutions represented by Sandia National Laboratory in the United States have also conducted a large number of experimental and theoretical studies on the mechanism of electrostatic ignition. They have studied the process of electrostatic discharge caused by different impurities in hydrogen pipelines, and related experiments have also confirmed the theory of electrostatic ignition. feasibility. However, in the experimental research of the diffusion ignition theory and the electrostatic ignition theory, there are some experimental phenomena that cannot be explained by each single theory, that is, the spontaneous combustion of hydrogen still occurs under the spontaneous combustion conditions that do not meet the spontaneous combustion conditions predicted by the respective theories. After theoretical analysis, it is found that there may be mutual coupling between different mechanisms, because factors such as shock wave, static electricity, inverse Joule Thomson effect and instantaneous adiabatic compression simultaneously exist in the process of hydrogen leakage, among which inverse Joule Thomson The effect exists in any hydrogen leakage and diffusion process, but the temperature rise it brings is not enough to trigger hydrogen spontaneous combustion, and instantaneous adiabatic compression only occurs in a small number of cases. In most cases, shock waves and Static electricity is the main source of energy leading to hydrogen spontaneous combustion. In the current research, only one of the factors of shock wave or static electricity is studied, and the mechanism of hydrogen spontaneous combustion cannot be fully revealed. Therefore, a comprehensive experimental platform is needed that can couple shock wave and static electricity. The main factors such as static electricity are studied at the same time, so as to comprehensively observe the spontaneous combustion process of hydrogen under the condition of all factors. However, the current various experimental devices can only achieve different levels of testing of a single factor, and it is difficult to conduct coupling experiments of multiple mechanisms. The main function of the utility model is to simultaneously measure the shock wave and static electricity generated in the process of hydrogen leakage, observe the coupling effect of the shock wave and static electricity, and analyze and study the coupling mechanism and influencing factors of the diffusion ignition theory and the electrostatic ignition theory.

Utility model content

In view of the above existing problems, the utility model aims to provide an experimental device that can test the effect of shock wave and electrostatic coupling in the process of high-pressure hydrogen gas release, which can simultaneously measure the effect of shock wave and static electricity on the hydrogen spontaneous combustion process, and realize the Quantitative analysis of multiple factors affecting the results at different levels. .

In order to achieve the above object, the technical scheme adopted in the utility model is as follows:

High-pressure hydrogen pipeline shock wave and electrostatic coupling measurement system and method, including hydrogen storage device, nitrogen purging device, release device, electrostatic induction device, pressure sensor array, photoelectric sensor array, electrostatic sensor array, signal acquisition device and computer, said The hydrogen storage device and the nitrogen purging device are respectively connected to the front end of the buffer tank through their corresponding inlet pipes, the inlet pipes are respectively provided with inlet valves, and the end of the buffer tank is provided with an emptying device and the A release device, the release device is respectively provided with the electrostatic sensor array connected to the static detection platform, the pressure sensor array and the photoelectric sensor array connected to the signal acquisition device, and the end of the release device is provided with the A static induction device and a photographing device, the photographing device, the signal acquisition device and the static monitoring platform are all connected to the computer.

As a further improvement, the release device includes a trapezoidal platform release device, a pipeline body, an upstream release device and a downstream release device, the pipeline body includes an upstream release pipe, a downstream release pipe and a nozzle arranged in sequence, and the end of the upstream release pipe passes through the The upstream release device is connected to the downstream release pipe, and the end of the downstream release pipe is connected to the nozzle through the downstream release device. switch.

As a further improvement, the release switch is a rupture disc holder or a pneumatic ball valve.

As a further improvement, the electrostatic sensor array includes No. 1 electrostatic sensor, No. 2 electrostatic sensor, No. 3 electrostatic sensor and No. 4 sensor arranged sequentially along the main body of the pipeline, and the No. 1 sensor is arranged in the main body of the pipeline and located at At the end of the upstream release device, the No. 2 electrostatic sensor and the No. 3 electrostatic sensor are located in the main body of the pipeline and are respectively arranged at both ends of the downstream release device. The nozzle end is provided with the 4 No. electrostatic sensor.

As a further improvement, the photoelectric sensor array includes three photoelectric sensors sequentially arranged on the outer wall of the pipeline main body, and the pressure sensor array includes sequentially arranged on the outer wall of the pipeline main body and corresponding to the three photoelectric sensors. Humidity sensors, For the temperature sensor and the pressure sensor, a three-way conduit is arranged below the buffer tank, and the humidity sensor, the temperature sensor, the pressure sensor and the three photoelectric sensors are respectively connected to the signal acquisition device and the three-way conduit through wires.

As a further improvement, the electrostatic induction device includes an electrostatic plate, an electrostatic probe, an insulating fixture and a support rod, the electrostatic plate is arranged at the end of the electrostatic sensor array, and the electrostatic plate is connected to the support rod below it through the insulating fixture , the end of the electrostatic plate is provided with the electrostatic probe, and the electrostatic probe is grounded.

Using the above-mentioned measurement system, the steps for measuring the shock wave and electrostatic coupling effect produced in the process of hydrogen leakage are as follows:

1) Add the measured particulate matter to either the upstream release device or the downstream release device, depending on the purpose of the test;

2) After adding the particulate matter, connect each device into a test system, and then perform an air tightness test on the assembled system to confirm that the air tightness is good;

3) Turn on the nitrogen purging device to discharge the air in the buffer tank, then turn on the hydrogen storage device to inject high-pressure hydrogen into the buffer tank, and activate the release switch after reaching the specified pressure, and the hydrogen will drive the particles along the main body of the pipeline to pass through the electrostatic sensor array and impact the electrostatic induction device to generate Spark discharge, electrostatic sensor array and pressure sensor array transmit the monitored data to the computer through the electrostatic detection platform and signal acquisition device respectively, and the shooting device transmits the observed ignition situation outside the tube to the computer;

4) Stop the supply of hydrogen, turn on the nitrogen purge device to extinguish the jet flame, and cool down the measuring system.

The beneficial effects of the utility model are: 1. The shock wave and electrostatic coupling experiment platform of the high-pressure hydrogen gas pipeline is established for the first time, and the shock wave generation, transfer process and static accumulation in the high-pressure hydrogen gas discharge process can be measured simultaneously in one experiment, During the release process, there is no need to change the device or repeat multiple measurements, which fundamentally ensures the accuracy of the experiment and improves the efficiency of the experiment; 2. Through the electrostatic sensor array inside the tube, the electrostatic sensor outside the tube, the induced static electrification device and the grounding probe The combination of the device can clearly and completely understand the process of the generation, accumulation and release of static electricity in the accompanying gas flow process. Compared with the earlier device, which can only measure the discharge energy when the static electricity is released outside the pipeline, the observation process is more complete;

3. Shock waves of different intensities can be generated through different types of release switches and release pressures; static electricity of different intensities can be generated through different adding positions and amounts of particles. Furthermore, by studying the frequency of hydrogen spontaneous combustion during the quantitative change process of the two factors, the degree of influence of different factors on hydrogen spontaneous combustion can be analyzed, and then the coupling effect of the two factors can be analyzed by comparing the experimental results of a single factor.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a structural schematic diagram of the trapezoidal platform release device.

Fig. 3 is a schematic diagram of the sectional structure of the nozzle.

Among them: 1-hydrogen storage device, 11-intake pipeline, 12-intake valve, 2-nitrogen purge device, 3-release device, 31-trapezoidal platform release device, 311-particles, 32-pipeline main body, 321- Upstream release pipe, 322-downstream release pipe, 323-nozzle, 33-upstream release device, 34-downstream release device, 35-release switch, 351-bursting disc, 4-static induction device, 41-static plate, 42-static Probe, 43-insulation fixture, 44-support rod, 5-pressure sensor array, 51-humidity sensor, 52-temperature sensor, 53-pressure sensor, 6-electrostatic sensor array, 61-1 electrostatic sensor, 62-2 No. electrostatic sensor, No. 63-3 electrostatic sensor, No. 64-sensor 4, 7-signal acquisition device, 8-buffer tank, 81-tee conduit, 82-photoelectric sensor array, 9-venting device, 10-shooting device, 101-high-speed camera, 102-infrared camera device.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the utility model, the technical solution of the utility model will be further described below in conjunction with the drawings and embodiments.

Referring to the high-pressure hydrogen pipeline shock wave and electrostatic coupling measurement system shown in Figure 1, it includes a hydrogen storage device 1, a nitrogen purge device 2, a release device 3, an electrostatic induction device 4, a pressure sensor array 5, an electrostatic sensor array 6, a signal Acquisition device 7, photoelectric sensor array 82, electrostatic detection platform, photographing device 10 and computer, described hydrogen storage device 1 and described nitrogen purging device 2 are respectively connected to the front end of buffer tank 8 through its corresponding air intake pipe 11, The intake pipe 11 is provided with an intake valve 12 for controlling the opening or closing of the intake pipe, and the end of the buffer tank 8 is provided with an emptying device 9 and the release device 3, and the release device 3 includes a trapezoidal platform release device 31 , the pipe body 32, the upstream release device 33 and the downstream release device 34, the pipe body 32 includes an upstream release pipe 321, a downstream release pipe 322 and a nozzle 323 arranged in sequence, and the end of the upstream release pipe 321 passes through the upstream release pipe Device 33 is connected with described downstream release pipe 322, and the end of described downstream release pipe 322 is connected with described nozzle 323 through described downstream release device 34, and described nozzle front end opening is big, and its diameter AB is 0.15m, and its end opening Small, with a diameter CD of 0.032m, which is used to control the jetting pattern of the air flow; the trapezoidal platform release device 31 and the release switch 35 at its end are sequentially arranged in the upstream release pipe 321 .

The nitrogen purging device is a commercial nitrogen cylinder, the cylinder pressure is 12.5MPa, the hydrogen storage device is a hydrogen cylinder, the inlet pipe and the buffer tank are both made of 304 stainless steel, and the maximum working pressure is 14MPa. The inner length of the hydrogen tank is 0.25m, the inner diameter of the tank is 0.12m, the length of the inlet pipe connected to the hydrogen cylinder is 1.5m, the inner diameter is 0.15m, the wall thickness of the inlet pipe and the tank is 0.015m, and the vent pipe is manually controlled by a ball valve When the release device fails, the high-pressure gas can be discharged to the external environment through the vent pipe; the release switch is a bursting disc holder or a pneumatic ball valve. When studying different working conditions, the downstream is connected to different The release switch; the length of the release pipe can be 0.36m or 1.2m or 3.05m, and the upstream release device and the downstream release device are respectively three-way connecting pipes with a length of 0.04m and an inner diameter of 0.015m. The protruding part of the shape can be used as a place to add particles, and the release device is also used as a fixing device connecting the upstream and downstream pipelines. When studying different working conditions, particles 311 are placed in the upstream release device or downstream release device.

The photoelectric sensor array 82 includes three photoelectric sensors arranged on the outer wall of the main body of the pipeline in turn, and the pressure sensor array 5 includes a humidity sensor 51, a temperature sensor and a temperature sensor respectively corresponding to the three photoelectric sensors and arranged on the outer wall of the main body of the pipeline 32 in turn. Sensor 52 and pressure sensor 53, the bottom of described buffer tank 8 is provided with the tee conduit 81 that communicates with it, described humidity sensor 51, described temperature sensor 52, described pressure sensor 53 and 3 described photoelectric sensors two The ends are respectively connected to the signal acquisition device 7 and the three-way conduit 10 through wires to record the state changes of the gas in the tube at all times.

The electrostatic sensor array 6 includes annular No. 1 electrostatic sensor 61, No. 2 electrostatic sensor 62, No. 3 electrostatic sensor 63, and No. 4 sensor 64 arranged sequentially along the pipeline main body 32, at 0.01 m downstream of the upstream release device The No. 1 electrostatic sensor 61 is installed, the No. 2 electrostatic sensor 62 and the No. 3 electrostatic sensor 63 are respectively arranged at the two ends of the downstream release device 34, and the No. 1-3 electrostatic sensors are all provided with There is an insulating layer, which is embedded in the inner wall of the main body of the pipeline, which ensures the smoothness and straightness of the inner wall of the release pipeline; 0.5m downstream of the nozzle 323, there is an annular No. 4 electrostatic sensor 64 with a diameter of 0.4m. No. 1 to No. 4 electrostatic sensors are all connected to the electrostatic detection platform.

The electrostatic induction device 4 includes an electrostatic plate 41, an electrostatic probe 42, an insulating fixture 43 and a support rod 44, and the electrostatic plate 41 is placed 1.5m downstream from the nozzle, and the electrostatic plate 41 is 0.25m in diameter and 0.01m in thickness. A circular tinned copper plate, which is connected to the supporting rod 44 below it through the insulating fixture 43, the electrostatic probe 42 is arranged 0.005m downstream of the center of the circular tinned copper plate, and the electrostatic probe 42 is grounded , the electrostatic probe detects the electrostatic charge generated by the tinned copper plate in the process of scouring the airflow containing impurities, and then calculates the energy released during the spark discharge process.

The photographing device 10 is set at a distance of 10 cm from the nozzle, and the photographing device 10 includes a high-speed camera 101 and an infrared camera 102 to detect the ignition situation outside the tube and analyze the ignition position.

The photographing device, the signal acquisition device and the static monitoring platform are all connected to the computer, and the model of the static monitoring platform in the utility model can be ETS-624 static monitoring platform.

Utilize above-mentioned high pressure hydrogen pipeline shock wave and the method for measuring with electrostatic coupling measuring system, its steps are:

1) Place the above-mentioned devices on a horizontal test bench, and all devices except the electrostatic induction device must be electrostatically grounded. According to the purpose of the test, add the measured particulate matter to the upstream release device or downstream release device;

2) Connect the various parts of the pipeline firmly, and then conduct an air tightness test on the assembled system. You can use soapy water to smear each connecting part to check the air tightness of the device and confirm that the air tightness is good;

In order to simulate the possible metal particles in the hydrogen pipeline, the substances that can be added include iron oxide, ferrous oxide, lead oxide, and silicon dioxide. The particle weight range of each substance is 0.1-5g, and the particle size D90<30μm. When it is necessary to measure the impact of the release switch on the electrostatic generation process, particles can be added to the trapezoidal platform upstream of the release switch; when studying the influence of the length of the main body of the pipeline and the electrostatic strength of the shock wave intensity under different release methods, the pipeline can be released downstream Upstream of the nozzle, particles can be added to the upstream release device near the release switch; when studying the generation of static electricity during the mixing of the nozzle jet with air, particles can be added to the downstream release device.

3) After adding the particles, turn on the nitrogen purge device to discharge the air in the buffer tank, close the valve of the nitrogen purge device, and then open the hydrogen storage device to inject high-pressure hydrogen into the buffer tank until the pressure gauge shows that the hydrogen in the buffer tank is about to arrive When the pressure is specified, reduce the flow of hydrogen gas; the high-pressure hydrogen gas forms a shock wave in the downstream release pipeline and is accompanied by the rapid flow of high-pressure hydrogen gas; the hydrogen gas drives the particles along the main body of the pipeline through the electrostatic sensor array to impact the electrostatic induction device to generate electric spark discharge, and the electrostatic sensor array And the pressure sensor array transmits the monitored data to the computer through the electrostatic detection platform and the signal acquisition device, and the shooting device transmits the observed ignition situation outside the tube to the computer;

4) After the ignition occurs, the valve of the hydrogen cylinder can be closed, the supply of hydrogen is stopped, the nitrogen purge device is turned on, the injection fire is extinguished, the temperature of the device is lowered, and the next round of experiments is prepared.

When the release switch is to activate the ball valve, the buffer tank can stop injecting hydrogen when it reaches the specified pressure; when the release switch is a bursting disc, it is necessary to continuously inject hydrogen until the bursting disc reaches the specified pressure and ruptures. After the pneumatic ball valve is opened or the bursting disc is ruptured, The high-pressure hydrogen jet quickly flows from the outlet of the buffer tank to the downstream of the main body of the pipeline. When passing through the upstream release device or downstream release device where the particles are placed, the particles placed in the device will be sucked into the high-speed airflow, advance along the pipeline and finally Together with the airflow, it is released to the external environment through the nozzle; the high-speed airflow rectified by the nozzle passes through the external No. 4 annular electrostatic sensor, and directly impacts the electrostatic plate (that is, the tinned copper plate) that induces electrostatic electrification, and the electrostatic plate is impacted. Electricity, because it has been insulated, it has accumulated a lot of static electricity. When the static electricity has accumulated to a certain extent, it will form a large enough potential difference with the grounding static probe on the right to cause spark discharge. At this time, the surrounding of the grounding static probe has been surrounded by hydrogen and Surrounded by a mixture of combustible gases in the air, the energy released by the spark discharge will ignite the surrounding gas, and the energy released by the spark will be recorded by the electrostatic detection platform.

In this process, the intensity and propagation speed of the shock wave can be detected by the pressure sensor array. If spontaneous combustion occurs in the tube, the pressure sensor can also be used to detect the overpressure pressure wave generated by the deflagration. position; the electrostatic sensor array can detect the charging of metal particles at different cross-sections in the pipeline, so as to analyze the accumulation and release process of static electricity; after the airflow is mixed with metal particles and released to the external space through the nozzle, it can be observed by high-speed camera and infrared imaging The action of airflow and electrostatically induced metal disc and the process of ignition by electrostatic spark discharge.

The basic principles, main features and advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (6)

1. high pressure hydrogen pipeline shock wave and electrostatic coupling measuring system, it is characterised in that including hydrogen-storing device, nitrogen purging dress Put, release device, electrostatic induction device, array of pressure sensors, photosensor arrays, electrostatic sensor array, signal are adopted Acquisition means and computer, the hydrogen-storing device and the nitrogen purging device pass through its corresponding admission line and surge tank respectively Front end connection, be respectively equipped with air intake valve in the air inlet pipe, the end of the surge tank is equipped with emptying device and described releases Device is put, the electrostatic sensor array being connected with electrostatic detection platform and the letter are respectively equipped with the release device The array of pressure sensors and photosensor arrays of number harvester connection, the end of the release device are equipped with described Electrostatic induction device and filming apparatus, the filming apparatus, the signal pickup assembly and the electrostatic monitoring platform are and institute State computer connection.

2. high pressure hydrogen pipeline shock wave according to claim 1 and electrostatic coupling measuring system, it is characterised in that described to release Putting device includes trapezoid platform release device, pipe main body, upstream release device and downstream release device, the pipe main body bag Upstream release pipe, downstream release pipe and the nozzle set gradually is included, the upstream release pipe end is discharged by the upstream to be filled To put and be connected with downstream release pipe, the downstream release pipe end is connected by the downstream release device with the nozzle, The trapezoid platform release device and the release switch positioned at its end are equipped with successively in the upstream release pipe.

3. high pressure hydrogen pipeline shock wave according to claim 2 and electrostatic coupling measuring system, it is characterised in that described to release It is rupture disk or pneumatic ball valve to decontrol pass.

4. high pressure hydrogen pipeline shock wave according to claim 3 and electrostatic coupling measuring system, it is characterised in that described quiet Electric transducer array includes No. 1 electrostatic transducer, No. 2 electrostatic transducers, No. 3 electrostatic biographies set gradually along the pipe main body Sensor and No. 4 electrostatic transducers, No. 1 electrostatic transducer are located in the pipe main body and are located at the upstream release device End, No. 2 electrostatic transducers and No. 3 electrostatic transducers are respectively positioned in the pipe main body and are respectively provided at described The both ends of downstream release device, the nozzle end are equipped with No. 4 electrostatic transducers.

5. high pressure hydrogen pipeline shock wave according to claim 2 and electrostatic coupling measuring system, it is characterised in that the light Electric transducer array includes 3 photoelectric sensors being sequentially arranged on pipe main body outer wall, and the array of pressure sensors includes It is sequentially arranged on the pipe main body outer wall and humidity sensor corresponding with 3 photoelectric sensors, temperature sensor respectively And pressure sensor, the surge tank lower section are equipped with threeway conduit, the humidity sensor, the temperature sensor, the pressure Force snesor and 3 photoelectric sensors are connected by conducting wire with signal pickup assembly and threeway conduit respectively.

6. according to claim 1-5 any one of them high pressure hydrogen pipeline shock wave and electrostatic coupling measuring system, its feature exists In the electrostatic induction device includes static board, electrostatic probe, dielectric holder and supporting rod, and static board is located at the electrostatic and passes Sensor array ends, the static board are connected by the dielectric holder with the supporting rod below, the static board End is equipped with the electrostatic probe, the electrostatic probe ground connection.