基于偏保守原则的大型LNG子母罐的合于使用评价

The fit-for-service evaluation of large LNG sub mother tanks based on a relatively conservative principle

参照GB/T 19624—2019《在用含缺陷压力容器安全评定》的相关要求,对某大型LNG子母罐进行合于使用评价,基于偏保守原则,运用简化评定的方法选择合适的评价参数,对LNG子母罐放空管异径三通裂纹部位的应力进行分析,对其尖端张开位移(CTOD)值δ和平面缺陷简化评定断裂比δr进行计算后,绘制出裂纹失效评定图,并与异径三通理化检验结果进行对比分析,确定了合于使用评价的结论。

According to the relevant requirements of GB/T 19624—2019 Safety Assessment of Pressure Vessel with Defects in Use,the fit-for-service evaluation of a large LNG sub mother tanks is carried out.Based on the relatively conservative principle,using the simplified assessment method,the appropriate assessment parameters are selected to analyze the stress at the crack position of the reducing tee,and the CTOD valueδand plane defect simplified assessment are carried out.After the fracture ratioδr is calculated,the failure assessment diagram of the crack is drawn,and is compared with the conventional test results,the test conclusion is determined.