车用压缩天然气全复合材料气瓶缺陷分析

Defect Analysis on Compressed Natural Gas All-Composite Materials Cylinder

在对车用压缩天然气全复合材料气瓶进行定期检验过程中,发现气瓶内胆出现鼓包和裂纹等缺陷。为了确定缺陷产生的原因,对复合气瓶内胆材质进行力学性能、微观分析、缠绕层和内胆材料线膨胀系数测试。在此基础上,采用工业CT方法分析了气瓶内压与缺陷产生的关系。分析认为,缠绕层与内胆材料线膨胀系数不同是复合气瓶产生鼓包和裂纹的根本原因,同时,充放气过程中的内压和温度的低周循环也是气瓶产生缺陷的重要因素。

During regular inspections on compressed natural gas all-composite materials cylinder,prone to defects such cracks and convex were found in cylinder.In order to determine the causes of defects,the mechanical properties of liner layer materials,micro-analysis,linear expansion coefficient of winding layer and liner layer were tested.On this basis,relationship between cylinder pressure and the defects was analyzed using industrial methods of CT.The results show that the different of linear expansion coefficient between winding layer and the liner material of composite cylinders is most fundamental reason.At the same time,at process of filling and deflating gas,low-frequency changes in temperature and pressure is an important factor to have defects.