备用天然气管道剩余寿命研究

Study on Residual Life of Spare Natural Gas Pipeline

采用美国改进的B31G准则对腐蚀备用管道剩余强度进行了计算,腐蚀管道的最大安全压力为14.14 MPa,腐蚀管道的爆破压力18.63MPa,最大腐蚀深度为8.636 mm,最小允许剩余壁厚1.364 mm。根据改进的B31G准则最大腐蚀深度应修正为8 mm,最小允许剩余壁厚2 mm。腐蚀管道剩余寿命计算采用局部腐蚀计算模型,最大允许缺陷深度H_(max)=6.1 mm,最小允许剩余壁厚为5.49 mm,管道设计压力为7.0 MPa腐蚀管道的剩余寿命为4.84年。若设计压力降至5.0 MPa和3.0 MPa时,在现场堆放年限为6.91和7.5年就完全报废。根据最大腐蚀深度将管道降级为实际壁厚8.3 mm来使用,则计算出降级使用后的管道使用年限为15.8年。

The residual pressure of the corrosion spare pipe is calculated by the improved B31G criterion ofthe United States. The maximum safety pressure of the corrosion spare pipe is 14.14 MPa, the burst pressure of the corrosion spare pipe is 18.63 MPa, the maximum corrosion depth is 8.636 ram, and the minimum allowable residual wall thickness is 1.364 mm. According to the improved B3 IG guidelines, the maximum corrosion depth should be corrected to 8ram, with a minimum allowable residual wall thickness of 2 mm. The remaining life of the corrosion spare pipe is calculated using the local corrosion calculation model, the maximum allowable detect depth Hmax=6.1 ram, the minimum allowable residual wall thickness is 5.49 mm, and the pipeline design pressure is 7.0 MPa The remaining life of the corrosion pipe is 4.84 years. If the design pressure drops to 5.0MPa and 3.0MPa, the on-site stacking time is 6.91 and 7.5 years is completely scrapped. According to the maximum corrosion depth of the pipeline down to the actual wall thickness of 8.3 mm to use, then calculate the use of pipeline after the use of downgraded to 15.8 years.