Material testing device under high-pressure hydrogen environment based on ionic liquids and operation method

Abstract

The invention relates to a testing technique of mechanical properties of materials, in order to provide a material testing device under a high-pressure-hydrogen environment based on ionic liquids and an operation method. A high-pressure hydrogen environment box of the device is internally provided with a cylindrical sample support; the lower end of a loading rod is connected with a power output device of a host machine, and the upper end of the loading rod penetrates through an end cover, and extends into the sample support to be connected with a sample fixture; the ionic liquids are filled in an internal space below an open pore in the top of the sample support; a balance cavity is arranged at the bottom of the end cover, and is composed of an extending section of the tail end of the end cover, a piston connected with the loading rod and a seal bottom cover of the balance cavity; and the loading rod is provided with a load sensor. According to the invention, the balancing cavity and the high-pressure hydrogen environment box transfer pressure by utilizing the ionic liquids, and the hydrogen leakage hazard generated when the pressure is transferred by using hydrogen is prevented; and high-pressure dynamic seal elements, rather than high-pressure hydrogen, in the device, are all in contact with the ionic liquids, thus hydrogen leakage is prevented, and the device safety is improved.

Description

technical field [0001] The invention belongs to the field of material mechanical property testing equipment development, and in particular relates to a material testing device and an operation method based on ionic liquid in a high-pressure hydrogen environment. Background technique [0002] With the increasingly prominent energy crisis and the continuous aggravation of environmental pollution, countries all over the world have stepped up the pace of exploration of new energy sources. With the advantages of diverse sources, clean and environmentally friendly, storable and renewable, hydrogen energy can meet the requirements of resources, environment and sustainable development at the same time, and it is a secondary energy source with great development potential in the future. In the process of hydrogen energy application, hydrogen is mostly stored and transported in the form of high pressure. In order to meet the needs of the vehicle's driving range, the pressure of high-p...

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Problems solved by technology

However, as the rated maximum outlet pressure of this type of booster pump increases, the corresponding flow rate gradually decreases. It usually takes several hours to pressurize the high-pressure hydrogen environment box to the test pressure (100~200 MPa), and the test efficiency is low.

[0005] (2) The real load applied to the sample cannot be measured more accurately

The sensitive components of the built-in load sensor will be affected by high-pressure hydrogen, and their resistance and other properties will change after a period of use, resulting in distortion of the measurement results

The value measured by the external load sensor includes the influence of the friction force at the high dynamic seal (between the loading rod and the O-ring seal), and the friction force changes with time, so it cannot be simply eliminated numerically

[0006] (3) The high-pressure dynamic seal cannot ensure that hydrogen gas does not leak, causing potential safety hazards

During the material fatigue performance test, the loading rod must constantly reciprocate relative to the O-ring seal, and the high-pressure hydrogen in direct contact with the O-ring seal is prone to leakage, posing a major safety hazard

[0007] (4) The hydrogen in the high-pressure hydrogen environment box will generate a force of up to several tons on the loading rod. When the sample breaks, this part of the force will have a huge impact on the host of the test device, reducing its control accuracy and life.

However, due to the small deformation of the loading rod during the test, the measurement sensitivity of the load-sensitive element is low; and this patch method needs to be completed on site, and the versatility and accuracy are relatively poor

The test machine proposed in the patent [201110259252.2] has the problems of slow hydrogen filling, long time consumption, and high-pressure hydrogen that is in direct contact with the O-ring seal is prone to leakage

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