CN104897472B - The experimental rig of multi-functional pressure differential High Pressure Hydrogen and material compatibility - Google Patents

Abstract

The present invention relates to material mechanical performance test equipment development field, it is desirable to provide the experimental rig of multi-functional pressure differential High Pressure Hydrogen and material compatibility.The experimental rig of the multi-functional pressure differential High Pressure Hydrogen and material compatibility includes experiment cavity, Pneumatic booster pump, low pressure storage tank, high pressure storage tank, vavuum pump, hydrogen cylinder group, argon bottle group and control system module, can carry out Mechanics Performance Testing to disk sample under high pressure hydrogen environment.The method that the present invention applies load using the pressure difference of disk sample upper and lower surface to disk sample, the servo test mechanism of complexity is avoided, equipment volume greatly reduces, and equipment investment reduces, easy to operate, and test efficiency improves；And during experiment, the parameter such as strain and displacement of disk sample can be measured easily, and corresponding testing element is not influenceed by high pressure hydrogen.

Description

Multifunctional differential pressure high pressure hydrogen and material compatibility test device

technical field

The invention relates to the field of development of material mechanical performance testing equipment, in particular to a multifunctional differential pressure type high pressure hydrogen and material compatibility testing device.

Background technique

Hydrogen is an important part of the clean utilization of fossil energy and the development of new energy. Hydrogen is usually stored and transported in gaseous form under high pressure. In recent years, due to the development trend of higher pressure of high-pressure hydrogen system and complex service environment, the compatibility problem of materials used in high-pressure hydrogen system and hydrogen (ie hydrogen embrittlement problem) has gradually become prominent. Hydrogen embrittlement will reduce the toughness of the material and increase the crack growth rate, which will cause a sudden and serious failure of the high-pressure hydrogen system during service, causing great hidden dangers to the safety of the people. In order to ensure the safety of the high-pressure hydrogen system, the materials used in the high-pressure hydrogen system must carry out experimental research on the compatibility with hydrogen.

In order to study the compatibility of metal materials with high-pressure hydrogen, the mechanical properties of materials should be tested in a high-pressure hydrogen environment (up to 100 MPa). This puts forward higher requirements on the corresponding test equipment. Many research institutions in the world have carried out the research and development of materials compatibility research equipment in high-pressure hydrogen environment, but the above-mentioned equipments all face the following key problems:

(1) The equipment structure is complicated, the cost is high, and the operation is complicated

Most of the hydrogen compatibility test devices currently developed are based on traditional material testing machines, plus an environment box that can provide a high-pressure hydrogen environment. The samples and their fixtures are contained inside the environment box. Therefore, the internal volume of the environment box Large, coupled with its usually high pressure (up to 100MPa), resulting in expensive equipment. In addition, a large-volume environmental chamber also needs to be equipped with a corresponding hydrogen gas supply system. The operation of the entire equipment is complicated, and the cost of hydrogen and labor is high. Such as the test device proposed in the patent [201110259252.2], not only the cost of the equipment itself is high, but each test requires multiple people to operate the equipment, and the hydrogen consumption is also large.

(2) There is a high-pressure hydrogen pneumatic sealing structure, which is prone to leakage

Existing material and hydrogen compatibility test devices all have loading rods running through the hydrogen environment chamber, so as to provide loading force for the samples inside the environment chamber. In order to maintain the pressure inside the environmental chamber, a dynamic sealing element is required at the contact between the loading rod and the environmental chamber. Practice has shown that the existing dynamic seal structure has a very short service life, and often fails suddenly due to wear and hydrogen dissolution and expansion after a short period of use, causing hydrogen leakage and posing a major safety hazard.

(3) It is difficult to measure various parameters of the sample in a high-pressure hydrogen environment

In a high-pressure hydrogen environment, due to the influence of hydrogen on the measuring elements such as sample strain and force, the signal will drift seriously, resulting in inaccurate measurement.

(4) There is a big difference between the stress state of the sample and the stress state of the actual component

Usually, the wall of the high-pressure hydrogen storage vessel is subjected to two-dimensional stress or three-dimensional stress during service. However, the existing testing machines usually test the failure behavior of samples under unidirectional stress, and there is still a certain gap between them and the actual service conditions of components.

Contents of the invention

The main purpose of the present invention is to overcome the deficiencies in the prior art and provide an experimental device that uses a disc-shaped thin slice as a sample and uses the pressure difference between the upper and lower surfaces of the disc sample to apply a load to the disc sample. In order to solve the problems of the technologies described above, the solution of the present invention is:

Provide a multifunctional differential pressure type high-pressure hydrogen and material compatibility test device, which can test the mechanical properties of disc samples in a high-pressure hydrogen environment (up to 100MPa). The test device includes a test chamber and a pneumatic booster pump , low-pressure storage tanks, high-pressure storage tanks, vacuum pumps, hydrogen cylinders, argon cylinders and control system modules;

The test cavity includes an end cover, an upper cavity, a lower cavity, and a pressure ring. The inner central cavity of the upper cavity and the lower cavity forms a connected cavity channel. Between the end cover and the upper cavity, the upper cavity The body and the lower cavity are respectively connected by end cover bolts and upper cavity bolts, and the joints are sealed with O-rings as sealing elements. After the end cover is added, the cavity channel can be sealed; the lower cavity is in the On the contact surface with the upper cavity, that is, on the upper surface of the lower cavity, there is a groove for placing the disc sample, and an O-ring is arranged between the disc sample and the groove of the lower cavity for Sealing; the pressure ring is embedded in the upper cavity and is interference fit with the upper cavity. The pressure ring is used to apply compressive stress to the disc sample placed in the groove of the lower cavity. The pressure ring and the upper cavity O-rings are provided between the pressure ring and the disc sample for sealing; the pressure ring is an annular pressure ring, the outer diameter of the pressure ring is the same as the diameter of the disc sample, and the inner diameter of the pressure ring is the same as that of the disc sample. The inner diameter of the upper cavity and the inner diameter of the lower cavity are the same; the upper cavity and the lower cavity are respectively provided with an upper cavity vent and a lower cavity vent;

The hydrogen cylinder group is used to provide hydrogen for testing, and the argon cylinder group is used to provide argon gas for replacement and testing. The air inlet of the tank, the discharge port of the low-pressure storage tank are connected to the pneumatic booster pump, the pneumatic booster pump is connected to the high-pressure storage tank, and the exhaust port of the high-pressure storage tank is connected with the upper cavity vent and the lower cavity vent respectively ;The upper cavity vent and the lower cavity vent are provided with a hydrogen discharge circuit directly connected to the low-pressure storage tank, which is used to recover the hydrogen discharged from the upper cavity or the lower cavity to the low-pressure storage tank; the upper cavity is ventilated There is a replacement pipeline directly connected to the argon gas cylinder group at the port and the vent port of the lower chamber, which is used for gas replacement of the upper chamber or the lower chamber; the vent port of the upper chamber and the vent port of the lower chamber are also connected with the vacuum pump. air inlet connection;

The hydrogen discharge circuit is provided with a hydrogen discharge circuit valve, an upper cavity flow control valve is provided at the upper cavity vent, a lower cavity flow control valve is provided at the lower cavity vent, and a vacuum pump air inlet is provided. There is a vacuum pump valve, and a high-pressure storage tank outlet valve is provided at the exhaust port of the high-pressure storage tank; the exhaust port of the hydrogen cylinder group, the exhaust port of the argon gas cylinder group, the air inlet of the low-pressure storage tank, There are valve A, valve B, valve C and valve D respectively on the replacement pipeline;

The control system module is used to control the operation of the pneumatic booster pump and the vacuum pump, and the opening degrees of all valves. Its realization can adopt hardware, software or a combination of hardware and software. Those skilled in the art can utilize existing technical means to realize relevant functions according to the functions described in the present invention. Since these contents are not the focus of the present invention, they will not be repeated here.

In the present invention, the air vent of the upper cavity and the vent of the lower cavity are also provided with vent pipelines and vent valves for control;

There is also a branch between the upper cavity vent and the lower cavity vent for communication, and a branch valve is provided on the branch; that is, there is a passage between the upper cavity vent and the lower cavity vent. The upper chamber flow control valve, the bypass valve, and the connecting pipeline of the lower chamber flow control valve;

A branch is also provided between the exhaust port of the hydrogen cylinder group and the exhaust port of the argon cylinder group for communication, and a valve E is arranged on the branch road; that is, the exhaust port of the hydrogen cylinder group, the argon cylinder group There is a connecting pipeline passing through valve A, valve E, and valve B between the exhaust ports of the hydrogen cylinder group, and the connecting pipeline between the exhaust port of the hydrogen cylinder group and the air inlet of the low-pressure storage tank passes through valve A, valve C. The connecting pipeline between the exhaust port of the argon cylinder group and the air inlet of the low-pressure storage tank passes through valve B, valve E, and valve C.

In the present invention, the test cavity, the low-pressure storage tank, and the high-pressure storage tank are all provided with pressure sensors, and can control the collection of pressure signals in the test cavity, low-pressure storage tank, and high-pressure storage tank through the control system module.

In the present invention, the design pressure of the test chamber is 35-100MPa, and both the upper chamber and the lower chamber are made of austenitic stainless steel, and the pressure ring is made of high-strength steel with a tensile strength greater than 800MPa. Manufactured rings.

A burst test method based on the test device is provided, specifically comprising the steps of:

Step A: Separate the upper cavity and the lower cavity. After installing the disk sample, use the upper cavity bolts to seal the upper cavity and the lower cavity, remove the end cover, and use the central cavity of the upper cavity to Disc sample layout displacement test device and strain test device;

Step B: Use a vacuum pump to pump out the residual air in the test device and auxiliary pipelines until the vacuum in the system reaches the set value, then use a pneumatic booster pump to fill the high-pressure storage tank with high-pressure hydrogen until the hydrogen pressure in the high-pressure storage tank reaches the set value. reach the set value;

Step C: Use the vacuum pump again to evacuate the lower cavity and its attached pipelines to the set vacuum degree, then turn off the vacuum pump, and let the hydrogen in the high-pressure storage tank enter the lower cavity at a specific rate through the flow control valve of the lower cavity In vivo, until the disk sample explodes, cut off the hydrogen source, record the burst pressure, and record the strain and displacement of the disk sample during the test;

Step D: After replacing the hydrogen in the test chamber and pipeline with argon at least once, separate the upper chamber and the lower chamber, and take out the disk sample.

Provide the variable hydrogen pressure fatigue test method based on described test device, specifically comprise the following steps:

Step E: Separate the upper cavity and the lower cavity. After installing the disk sample, use the upper cavity bolts to seal the upper cavity and the lower cavity, remove the end cover, and use the central cavity of the upper cavity to Disc sample layout displacement test device and strain test device;

Step F: Use a vacuum pump to remove the residual air in the test device and auxiliary pipelines until the vacuum in the system reaches the set value, then use a pneumatic booster pump to fill the high-pressure storage tank with high-pressure hydrogen until the hydrogen pressure in the high-pressure storage tank reaches the set value. reach the set value;

Step G: Use the vacuum pump again to evacuate the lower cavity and its attached pipelines to the set vacuum degree, then turn off the vacuum pump, and let the hydrogen in the high-pressure storage tank enter the lower cavity at a specific rate through the flow control valve of the lower cavity In the body, until the pressure reaches the upper limit of the test pressure (the upper limit of the test pressure is less than the burst pressure of the disc sample), stop filling the hydrogen, and then discharge the hydrogen in the lower cavity to the low-pressure storage tank, when the pressure in the lower cavity reaches the lower limit of the test pressure , stop dehydrogenation, and then continuously repeat the above hydrogen charging and dehydrogenation process until the disk sample is destroyed;

Step H: record the number of fatigue cycles experienced by the disk sample before failure, use argon to replace the hydrogen in the test chamber and pipeline at least once, separate the upper chamber and the lower chamber, and take out the disk sample.

A constant hydrogen pressure fatigue test method based on the test device is provided, which specifically includes the following steps:

Step I: Separate the upper cavity and the lower cavity, and after installing the disc sample, use the upper cavity bolts to seal the upper cavity and the lower cavity, and fill the upper part of the disc sample with ions with a depth of 5-10mm liquid, and then use the end cover bolts to seal the end cover and the upper cavity;

Step J: Use a vacuum pump to pump out the residual air in the test device and auxiliary pipelines until the vacuum in the system reaches the set value, then use a pneumatic booster pump to fill the high-pressure storage tank with high-pressure hydrogen until the hydrogen pressure in the high-pressure storage tank reaches the set value. reach the set value;

Step K: Use the vacuum pump again to evacuate the upper cavity, the lower cavity and the associated pipelines to the set vacuum degree, then turn off the vacuum pump, and make the hydrogen in the high-pressure storage tank flow at a specific rate through the flow control valve of the lower cavity. rate into the lower cavity, until the pressure reaches the set value, stop hydrogen charging, close the flow control valve of the lower cavity, and keep the hydrogen pressure in the lower cavity constant throughout the test process;

Step L: Make the hydrogen in the high-pressure storage tank enter the upper chamber at a specific rate through the upper chamber flow control valve until the pressure reaches the set pressure upper limit, stop hydrogen filling, and then discharge the hydrogen in the upper chamber to the low-pressure storage tank tank, when the pressure in the upper cavity reaches the lower limit of the set pressure, stop dehydrogenation, and then repeat the above hydrogen filling and dehydrogenation process continuously until the disk sample is destroyed;

Step M: Record the number of fatigue cycles experienced by the disk sample before failure, use argon to replace the hydrogen in the test chamber and pipeline at least once, separate the upper chamber and the lower chamber, and take out the disk sample.

In the present invention, the thickness of the disc sample is 0.5 to 2 mm, and the disc sample adopts a flat disc sample or a straw hat-shaped disc sample, and the straw hat-shaped disc sample refers to a central protrusion, an edge Planar disk specimens, and ensure that the diameter of the raised structure in the middle is not greater than the inner diameter of the compression ring.

In the present invention, the displacement testing device adopts a linear variable differential transformer (LVDT) displacement sensor.

In the present invention, the strain testing device adopts a resistive strain gauge.

Compared with prior art, the beneficial effect of the present invention is:

1. The present invention uses the pressure difference between the upper and lower surfaces of the disk sample to apply load to the disk sample, avoiding the complicated servo test mechanism, greatly reducing the equipment volume, reducing equipment investment, easy operation, and improving test efficiency.

2. The device of the present invention avoids the use of high-pressure dynamic sealing components, which can reduce the probability of hydrogen leakage and improve the reliability and safety of the device.

3. In the test process of the invention, parameters such as strain and displacement of the disk sample can be measured conveniently, and the corresponding test components are not affected by high-pressure hydrogen.

4. The stress state of the disk sample is two-way stress, which is more suitable for the actual service state of the component than the traditional one-way stress sample, and the shape of the disk sample can be adjusted, such as flat or convex in the middle. Straw hat shape with raised and flat edges to study the performance of materials under different stress states.

Description of drawings

Figure 1 is a schematic diagram of the overall device of the present invention.

Fig. 2 is a sectional view of the test chamber in the present invention.

Figure 3 is a schematic diagram of the structure of the displacement and strain testing device.

Figure 4 is a schematic diagram of the layout of the ionic liquid.

Fig. 5 is a schematic diagram of a planar disc sample.

Figure 6 is a schematic diagram of a straw hat-shaped disk sample.

The reference signs in the figure are: 1 hydrogen cylinder group; 2 low pressure storage tank; 3 hydrogen discharge circuit valve; 4 pneumatic booster pump; 5 high pressure storage tank; 6 hydrogen discharge circuit; 7 venting valve; 8 vacuum pump valve; 9 vacuum pump ;10 upper cavity flow control valve; 11 end cover; 12 upper cavity; 13 lower cavity; 14 lower cavity flow control valve; 15 branch valve; 16 high pressure storage tank outlet valve; 17 control system module; 18 replacement Pipeline; 19 argon cylinder group; 20 end cap bolts; 21 upper cavity bolts; 22 O-ring; 23 disk sample; 24 pressure ring; 25 upper cavity vent; 28 strain test device; 29 ionic liquid; 30 planar disk sample; 31 straw hat-shaped disk sample.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

As shown in Figure 1, the multifunctional differential pressure type high-pressure hydrogen and material compatibility test device includes a test chamber, a pneumatic booster pump 4, a low-pressure storage tank 2, a high-pressure storage tank 5, a vacuum pump 9, and a hydrogen cylinder set 1 , argon cylinder set 19 and control system module 17. The test device uses a disc-shaped thin slice as a sample, and can use the pressure difference between the upper and lower surfaces of the disc sample 23 under a high-pressure hydrogen environment (up to 100 MPa) to apply a load to the disc sample 23 for mechanical performance testing.

As shown in Figure 2, the test cavity includes an end cover 11, an upper cavity 12, a lower cavity 13, and a pressure ring 24, and the design pressure of the test cavity is 35-100 MPa; the upper cavity 12 and the lower cavity 13 Made of austenitic stainless steel with good hydrogen embrittlement resistance to ensure the life and reliability of the test chamber; the pressure ring 24 is made of high-strength steel to ensure that it can apply sufficient compressive stress to the disc sample 23 . The inner central cavity of the upper cavity 12 and the lower cavity 13 forms a connected cavity passage, and the end cover 11 and the upper cavity 12, and between the upper cavity 12 and the lower cavity 13 are respectively passed through the end cover bolts 20, The upper cavity is connected by bolts 21, and O-rings 22 are used as sealing elements for sealing at the joints. After the end cover 11 is added, the sealing of the cavity channel can be realized. In the burst test and variable hydrogen pressure fatigue test, the end cover 11 can be removed, and then the displacement test device 27 and the strain test device 28 can be arranged through the cavity channel at the center of the upper cavity body 12, and then the disc sample 23 can be measured at Corresponding parameter changes during the test.

Lower cavity 13 is on the contact surface with upper cavity 12, namely on the upper surface of lower cavity 13, is provided with the groove that is used to place disc sample 23, and the disc sample 23 and lower cavity 13 An O-ring 22 is arranged between the grooves for sealing. The pressure ring 24 is embedded in the upper cavity 12 and has an interference fit with the upper cavity 12. The pressure ring 24 is used to apply compressive stress to the disk sample 23 placed in the groove of the lower cavity 13. O-rings 22 are respectively provided between the ring 24 and the upper cavity 12 and between the pressure ring 24 and the disk sample 23 for sealing. The pressure ring 24 adopts an annular pressure ring, and the outer diameter of the pressure ring 24 is the same as the diameter of the disc sample 23, and the inner diameter of the pressure ring 24 is the same as the inner diameter of the upper cavity 12 and the inner diameter of the lower cavity 13; the upper cavity The body 12 and the lower cavity 13 are respectively provided with an upper cavity vent 25 and a lower cavity vent 26 . The thickness of the disc sample 23 is 0.5 to 2 mm, and the disc sample 23 adopts a planar disc sample 30 or a straw hat-shaped disc sample 31, and the straw hat-shaped disc sample 31 refers to a middle protrusion, an edge A flat disk sample, and ensure that the diameter of the middle raised structure is not greater than the inner diameter of the pressure ring 24.

The hydrogen cylinder group 1 is used to provide hydrogen for testing, and the argon cylinder group 19 is used to provide argon for replacement and testing. The exhaust port of the hydrogen cylinder group 1 and the exhaust port of the argon cylinder group 19 are respectively Connected to the air inlet of the low-pressure storage tank 2, the discharge port of the low-pressure storage tank 2 is connected to the pneumatic booster pump 4, the pneumatic booster pump 4 is connected to the high-pressure storage tank 5, and the exhaust port of the high-pressure storage tank 5 is respectively connected to the upper chamber The body vent 25 communicates with the lower cavity vent 26. The upper cavity vent 25 and the lower cavity vent 26 are provided with a hydrogen discharge circuit 6 directly connected to the low-pressure storage tank 2, so that in the variable hydrogen pressure fatigue test and the constant hydrogen pressure fatigue test, the upper cavity 12 or the lower The hydrogen gas discharged from the cavity 13 is recovered to the low-pressure storage tank 2, thereby avoiding the waste of hydrogen gas. The upper cavity vent 25 and the lower cavity vent 26 are provided with a replacement pipeline 18 directly connected to the argon cylinder set 19 for gas replacement of the upper cavity 12 or the lower cavity 13 . The upper cavity vent 25 and the lower cavity vent 26 are also connected to the air inlet of the vacuum pump 9 .

The upper chamber vent 25 is provided with an upper chamber flow control valve 10, and the lower chamber vent 26 is provided with a lower chamber flow control valve 14, and the two valves are used to control the rate of hydrogen charging and degassing. The hydrogen discharge circuit 6 is provided with a hydrogen discharge circuit valve 3 , a vacuum pump valve 8 is provided at the air inlet of the vacuum pump 9 , and a high pressure storage tank outlet valve 16 is provided at the exhaust port of the high pressure storage tank 5 . Valve A, valve B, valve C, valve D.

The upper cavity vent 25 and the lower cavity vent 26 are also provided with venting pipelines and vent valves 7 for control. A branch is also provided between the upper cavity vent 25 and the lower cavity vent 26 for communication, and a branch valve 15 is provided on the branch; that is, the upper cavity vent 25 and the lower cavity vent 26 There are communication pipelines passing through the upper cavity flow control valve 10, the branch valve 15, and the lower cavity flow control valve 14. A branch is also provided between the exhaust port of the hydrogen cylinder group 1 and the exhaust port of the argon cylinder group 19 for communication, and a valve E is arranged on the branch; that is, the exhaust port of the hydrogen cylinder group 1, the argon gas cylinder group 1 Between the exhaust ports of the gas cylinder group 19, there is a communication pipeline passing through valve A, valve E, and valve B, and the communication pipe between the exhaust port of the hydrogen cylinder group 1 and the air inlet of the low-pressure storage tank 2 is ensured. The pipeline passes through valve A and valve C, and the communication pipeline between the exhaust port of the argon cylinder set 19 and the air inlet of the low-pressure storage tank 2 passes through valve B, valve E and valve C.

The control system module 17 is used for the collection of pressure signals in the test chamber, the high-pressure storage tank 5 and the low-pressure storage tank 2, the operation control of the pneumatic booster pump 4 and the vacuum pump 9, and the opening control of all valves.

Using the above-mentioned test device, the main types of tests that can be completed include blasting test, variable hydrogen pressure fatigue test and constant hydrogen pressure fatigue test. The tests described below involved the use of a displacement measuring device 27 and a strain measuring device 28 . The displacement testing device 27 adopts a linear variable differential transformer type (LVDT) displacement sensor. The strain testing device 28 adopts a resistive strain gauge.

In the burst test, the pressure difference between the upper and lower surfaces of the disk sample 23 is continuously increased at a certain rate until the disk bursts, and a corresponding burst pressure is obtained. As shown in Fig. 1, Fig. 2 and Fig. 3, the blasting test test method based on the test device specifically includes the following steps:

Step A: Separate the upper cavity 12 and the lower cavity 13, install the disk sample 23, use the upper cavity bolt 21 to seal the upper cavity 12 and the lower cavity 13, remove the end cover 11, use the upper cavity Displacement testing device 27 and strain testing device 28 are arranged on disc sample 23 in the central cavity of cavity 12;

Step B: Use the vacuum pump 9 to pump out the residual air in the test device and the auxiliary pipeline until the vacuum degree in the system reaches the set value, then use the pneumatic booster pump 4 to fill the high-pressure storage tank 5 with high-pressure hydrogen until the high-pressure storage tank 5, the hydrogen pressure in reaches the set value;

Step C: Use the vacuum pump 9 again to evacuate the lower cavity 13 and its attached pipelines to the set vacuum degree, then turn off the vacuum pump 9, keep the branch valve 15 closed, and open the outlet valve 16 of the high-pressure storage tank and the lower cavity The flow control valve 14 allows the hydrogen in the high-pressure storage tank 5 to enter the lower cavity 13 at a specific rate until the disk sample 23 bursts, then cut off the hydrogen source immediately, record the burst pressure, and record the disk pressure during the test. Strain and displacement of sample 23;

Step D: After replacing the hydrogen in the corresponding pipeline with argon several times through the replacement pipeline 18, separate the upper cavity 12 and the lower cavity 13, and take out the disk sample 23.

The variable hydrogen pressure fatigue test is to apply a cyclic load to the disk by cyclically charging and degassing hydrogen only on one side of the disk sample 23. After a certain number of repetitions, the disk ruptures. During this process, the disk sample 23 is positively correlated with the hydrogen pressure it receives and the load it bears. As shown in Figure 1, Figure 2 and Figure 3, the variable hydrogen pressure fatigue test method based on the test device specifically includes the following steps:

Step E: Separate the upper cavity 12 and the lower cavity 13, install the disk sample 23, use the upper cavity bolts 21 to seal the upper cavity 12 and the lower cavity 13, remove the end cover 11, and use the upper cavity Displacement testing device 27 and strain testing device 28 are arranged on disc sample 23 in the central cavity of cavity 12;

Step F: Use the vacuum pump 9 to pump out the residual air in the test device and the auxiliary pipeline until the vacuum degree in the system reaches the set value, then use the pneumatic booster pump 4 to fill the high-pressure storage tank 5 with high-pressure hydrogen until the high-pressure storage tank 5, the hydrogen pressure in reaches the set value;

Step G: Use the vacuum pump 9 again to evacuate the lower cavity 13 and its attached pipelines to the set vacuum degree, then turn off the vacuum pump 9, keep the branch valve 15, the upper cavity flow control valve 10, and the hydrogen discharge circuit valve 3 and the vent valve 7 is closed, and the outlet valve 16 of the high-pressure storage tank and the flow control valve 14 of the lower cavity are opened, so that the hydrogen in the high-pressure storage tank 5 enters the lower cavity 13 at a specific rate until the pressure in the lower cavity 13 reaches After the upper limit of the test pressure (the upper limit of the test pressure is less than the burst pressure of the disc sample 23), close the outlet valve 16 of the high-pressure storage tank, open the branch valve 15 and the hydrogen discharge circuit valve 3, and discharge the hydrogen in the lower cavity 13 to a low pressure. In the storage tank 2, when the pressure in the lower cavity 13 reaches the lower limit of the test pressure, close the bypass valve 15 and the hydrogen discharge circuit valve 3, and then open the high-pressure storage tank outlet valve 16 again to charge the lower cavity 13 with hydrogen, repeat Repeat the above process of hydrogen filling and dehydrogenation until the disk sample 23 is destroyed;

Step H: record the number of fatigue cycles experienced by the disc sample 23 before it is destroyed, and replace the hydrogen in the corresponding pipeline with argon through the replacement pipeline 18 several times, separate the upper cavity 12 and the lower cavity 13, and take out Disc specimen 23.

During the constant hydrogen pressure fatigue test, the hydrogen pressure on the disk sample 23 is constant, but the load it bears changes cyclically. During this process, because the ionic liquid 29 has isolated the contact of the upper surface of the disk sample 23 with hydrogen, only the lower surface of the disk sample 23 is in contact with the hydrogen of constant pressure; The hydrogen pressure in the upper cavity 12 varies in cycles. As shown in Figure 1, Figure 2 and Figure 4, the constant hydrogen pressure fatigue test test method based on the test device specifically includes the following steps:

Step I: separate the upper cavity 12 and the lower cavity 13, after installing the disc sample 23, use the upper cavity bolt 21 to seal the upper cavity 12 and the lower cavity 13, and fill the upper cavity of the disc sample 23 Insert the ionic liquid 29 with a depth of 5-10mm, and then seal the end cover 11 and the upper cavity 12 with the end cover bolt 20;

Step J: Use the vacuum pump 9 to pump out the residual air in the test device and the auxiliary pipeline until the vacuum degree in the system reaches the set value, then use the pneumatic booster pump 4 to fill the high-pressure storage tank 5 with high-pressure hydrogen until the high-pressure storage tank 5, the hydrogen pressure in reaches the set value;

Step K: Use the vacuum pump 9 again to evacuate the upper cavity 12, the lower cavity 13 and their attached pipelines to the set vacuum degree, then turn off the vacuum pump 9, keep the branch valve 15, the upper cavity flow control valve 10 . The hydrogen discharge circuit valve 3 and the vent valve 7 are closed, and the high-pressure storage tank outlet valve 16 and the lower cavity flow control valve 14 are opened, so that the hydrogen in the high-pressure storage tank 5 enters the lower cavity 13 at a specific rate until the lower cavity After the pressure in the body 13 reaches the set value, close the flow control valve 14 of the lower cavity to keep the hydrogen pressure in the lower cavity 13 constant throughout the test process;

Step L: Open the branch valve 15 and the upper cavity flow control valve 10, so that the hydrogen in the high pressure storage tank 5 enters the upper cavity 12 at a specific rate, until the pressure reaches the set pressure upper limit, close the branch valve 15 , open the hydrogen discharge circuit valve 3, so that the hydrogen in the upper cavity 12 is discharged into the low-pressure storage tank 2, when the pressure in the upper cavity 12 reaches the lower limit of the test pressure, close the hydrogen discharge circuit valve 3, and then open the branch circuit again The valve 15 charges the upper cavity 12 with hydrogen, and repeats the above-mentioned process of charging and dehydrogenating the upper cavity 12 until the disk sample 23 is destroyed;

Step M: record the number of fatigue cycles experienced by the disk sample 23 before it is destroyed, and replace the hydrogen in the corresponding pipeline with argon through the replacement pipeline 18 several times, separate the upper cavity 12 and the lower cavity 13, and take out Disc specimen 23.

Among the above test methods, the results of the variable hydrogen pressure fatigue test and the constant hydrogen pressure fatigue test are quite different, and the two tests have their own corresponding application conditions. The burst pressure and fatigue life of disk sample 23 will be reduced when contacted with high-pressure hydrogen gas compared with other cases, which is caused by the damage of hydrogen gas to the material. Based on the above-mentioned test device and test method, the burst pressure and fatigue life of the disk sample 23 in a high-pressure hydrogen environment can be obtained, and the above data can be used to evaluate the compatibility of materials with a high-pressure hydrogen environment.

In the present invention, the pressure difference between the upper and lower surfaces of the disk sample 23 is used to apply load to it, which avoids the complicated servo test mechanism, greatly reduces the weight and volume of the equipment, reduces the cost, is easy to operate, and improves the test efficiency. The hydrogen consumption in the test is less; the use of high-pressure dynamic sealing components is avoided in the device, which can reduce the probability of hydrogen leakage and improve the reliability and safety of the device; during the test, the parameters such as strain and displacement of the disc sample 23 can be It is convenient to measure, and the corresponding test components are not affected by high-pressure hydrogen. For example, the traditional material and hydrogen compatibility test device proposed in the patent [201110259252.2], only the servo mechanism plus the supporting oil source system weighs several tons, the total height of the equipment usually exceeds 4 meters, and the high-pressure hydrogen environment box usually reaches several tons. Tons of weight, equipment investment of several million yuan, and more than 2 people are required for each operation, more than 5 hours of preparation work before each test, the volume of the high-pressure hydrogen environment box usually exceeds 10L, the test consumes a lot of hydrogen, and the equipment is dynamically sealed Hydrogen leakage is prone to occur in the place, and the signal of test components such as strain is easily affected by high-pressure hydrogen. In contrast, the multifunctional differential pressure high-pressure hydrogen and material compatibility test device does not require complicated supporting facilities. The diameter of the main component test chamber is 150-200 mm, the height is 200-250 mm, and the weight of the test chamber is about 50 kg. It can be greatly reduced, and the device is easy to operate; the inner volume of the test chamber is about 50mL, the test consumes a small amount of hydrogen, and the corresponding parameter requirements of the gas supply system can also be reduced; all the sealing elements in the device are static sealing O-rings 22. Hydrogen leakage is not easy to occur. The displacement test device 27 and the strain test device 28 in the device are isolated from the high-pressure hydrogen, and the signal is stable.

Finally, it should be noted that what is listed above are only specific embodiments of the present invention. Apparently, the present invention has been disclosed above with preferred implementation examples, but it is not intended to limit the present invention. Any skilled person who is familiar with this field can make use of the structure and technical content disclosed above without departing from the scope of the technical solution of the present invention. Equivalent implementations of equivalent changes without certain changes or modifications. For example, the present invention does not limit the gas in the test chamber to be high-pressure hydrogen, and it is also applicable to material compatibility tests in gas environments such as high-pressure hydrogen sulfide gas, high-pressure hydrogen and natural gas mixture. Any simple modifications, equivalent changes and modifications made to the above implementation cases according to the technical essence of the present invention, which do not deviate from the technical solution of the present invention, still fall within the scope of the technical solution of the present invention.

Claims (3)

1. The multi-functional differential pressure type high-pressure hydrogen and material compatibility test device can test the mechanical properties of disc samples in a high-pressure hydrogen environment. It is characterized in that the test device includes a test chamber, a pneumatic pressurized Pumps, low-pressure storage tanks, high-pressure storage tanks, vacuum pumps, hydrogen cylinders, argon cylinders and control system modules; The test cavity includes an end cover, an upper cavity, a lower cavity, and a pressure ring. The inner central cavity of the upper cavity and the lower cavity forms a connected cavity channel. Between the end cover and the upper cavity, the upper cavity The body and the lower cavity are respectively connected by end cover bolts and upper cavity bolts, and the joints are sealed with O-rings as sealing elements. After the end cover is added, the cavity channel can be sealed; the lower cavity is in the On the contact surface with the upper cavity, that is, on the upper surface of the lower cavity, there is a groove for placing the disc sample, and an O-ring is arranged between the disc sample and the groove of the lower cavity for Sealing; the pressure ring is embedded in the upper cavity and is interference fit with the upper cavity. The pressure ring is used to apply compressive stress to the disc sample placed in the groove of the lower cavity. The pressure ring and the upper cavity O-rings are provided between the pressure ring and the disc sample for sealing; the pressure ring is an annular pressure ring, the outer diameter of the pressure ring is the same as the diameter of the disc sample, and the inner diameter of the pressure ring is the same as that of the disc sample. The inner diameter of the upper cavity is the same as that of the lower cavity; the upper cavity and the lower cavity are respectively provided with an upper cavity vent and a lower cavity vent; the upper cavity vent and the lower cavity vent are also There is a venting pipeline and a venting valve for control; There is also a branch between the vent of the upper cavity and the vent of the lower cavity for communication, and a branch valve is set on the branch; Body flow control valves, branch valves, and connecting pipelines of lower cavity flow control valves; The hydrogen cylinder group is used to provide hydrogen for testing, and the argon cylinder group is used to provide argon gas for replacement and testing. The air inlet of the tank, the discharge port of the low-pressure storage tank are connected to the pneumatic booster pump, the pneumatic booster pump is connected to the high-pressure storage tank, and the exhaust port of the high-pressure storage tank is connected with the upper cavity vent and the lower cavity vent respectively ;The upper cavity vent and the lower cavity vent are provided with a hydrogen discharge circuit directly connected to the low-pressure storage tank, which is used to recover the hydrogen discharged from the upper cavity or the lower cavity to the low-pressure storage tank; the upper cavity is ventilated There is a replacement pipeline directly connected to the argon gas cylinder group at the port and the vent port of the lower chamber, which is used for gas replacement of the upper chamber or the lower chamber; the vent port of the upper chamber and the vent port of the lower chamber are also connected with the vacuum pump. air inlet connection; A branch is also provided between the exhaust port of the hydrogen cylinder group and the exhaust port of the argon cylinder group for communication, and a valve E is arranged on the branch road; that is, the exhaust port of the hydrogen cylinder group, the argon cylinder group There is a connecting pipeline passing through valve A, valve E, and valve B between the exhaust ports of the hydrogen cylinder group, and the connecting pipeline between the exhaust port of the hydrogen cylinder group and the air inlet of the low-pressure storage tank passes through valve A, valve C. The connecting pipeline between the exhaust port of the argon cylinder group and the air inlet of the low-pressure storage tank passes through valve B, valve E, and valve C; The hydrogen discharge circuit is provided with a hydrogen discharge circuit valve, an upper cavity flow control valve is provided at the upper cavity vent, a lower cavity flow control valve is provided at the lower cavity vent, and a vacuum pump air inlet is provided. There is a vacuum pump valve, and a high-pressure storage tank outlet valve is provided at the exhaust port of the high-pressure storage tank; the exhaust port of the hydrogen cylinder group, the exhaust port of the argon gas cylinder group, the air inlet of the low-pressure storage tank, Valve A, valve B, valve C, and valve D are respectively arranged on the replacement pipeline; The control system module is used to control the operation of the pneumatic booster pump and the vacuum pump, and the opening degrees of all valves. 2. The test device according to claim 1, characterized in that pressure sensors are arranged in the test cavity, the low-pressure storage tank and the high-pressure storage tank, and the test cavity and the low-pressure storage tank can be controlled by the control system module. , Acquisition of pressure signals in high-pressure storage tanks. 3. The test device according to any one of claims 1 to 2, characterized in that the design pressure of the test chamber is 35-100 MPa, and both the upper chamber and the lower chamber are made of austenitic stainless steel The cavity and the pressure ring are made of high-strength steel with a tensile strength greater than 800MPa.