Non-metal liner composite gas cylinder in the application process of the plastic liner composite gas cylinder

Anhui Clean Energy Co., Ltd. is a company that produces and sells various seamless cylinders and composite inner cylinders such as compressed natural gas cylinders for vehicles, industrial gas cylinders, fire cylinders, etc. The company is committed to providing automotive green energy solutions and related environmental protection supporting services.

In China, high-pressure hydrogen storage cylinders are gradually developing from all-metal cylinders (type I cylinders) to non-metal inner liner fiber full-wound cylinders (Type IV cylinders). Type III bottles and type IV bottles belong to the gas cylinders made of fiber composite winding materials, which mainly contain the inner liner and carbon fiber winding layer. The inner liner of type III bottles is aluminum alloy or steel, while the inner liner of type IV bottles is polymer. The fiber composite material will be wound around the outer edge of the inner liner in the form of spiral and hoop, thereby enhancing the structural strength of the inner liner.

  High pressure hydrogen storage cylinder is the key technology for the wide use of compressed hydrogen. With the increasing application demand of the application end, lightweight high pressure is the unremitting pursuit of the development of high pressure hydrogen storage cylinder. At present, high-pressure hydrogen storage vessels have gradually developed from all-metal cylinders (type I bottles) to non-metal inner liner fiber full-wound cylinders (type IV bottles). Anhui Clean  Energy will start CHG4 cylinder research and development in 2022, and cooperate with a number of domestic universities and scientific research institutions. Up to the present position, the sample development of 35MPa hydrogen storage four-type gas cylinder has been completed, and evidence is being obtained. 70Mpa hydrogen storage cylinder Type 4 is under development.

  The key technology of non-metal cylinder is the selection of plastic cylinder material and the design of cylinder structure. The choice of liner material will directly affect the head connection form of the liner, the permeability of the medium and the forming process.

However, in the application process of the plastic liner composite gas cylinder, because the connection strength of the liner and the valve seat is not enough, the modulus and thermal expansion rate of the two materials are greatly different, and the stiffness is discontinuous, under the action of cyclic load, the connection part of the two materials will produce cracks; At the same time, the air leakage in repeated filling and use is also because of the existence of thermal stress, affected by the ambient temperature, the appearance of heat treatment will cause cracks in the joint part. Although domestic and foreign technicians have carried out many research tests for the combination of metal bottle mouth and plastic liner, how to seal between the metal part and the plastic liner is still an urgent problem that needs to be solved.