CAJ | 학술논문

基于API581的风险评估技术（ RBI）是近年来石化行业逐渐采用并得到认可的一种新的评估设备经济可行性和安全性的技术。但是由于LNG的温度一般低至－162℃，使得LNG设备在应用API581时受到了限制。低温脆性断裂是LNG设备需考虑的一项主要的失效模式，API在评估脆断损伤因子时的温度范围是－73～38℃。为了能够评估LNG设备在低温环境下的风险，通过遗传算法将温度扩展至－209℃。扩展得到的脆断损伤因子曲线同夏比冲击试验的冲击功随温度变化曲线的趋势基本一致，因此扩展的损伤因子可以满足低温环境下LNG设备的风险评估。
기우API581적풍험평고기술（ RBI）시근년래석화행업축점채용병득도인가적일충신적평고설비경제가행성화안전성적기술。단시유우LNG적온도일반저지－162℃，사득LNG설비재응용API581시수도료한제。저온취성단렬시LNG설비수고필적일항주요적실효모식，API재평고취단손상인자시적온도범위시－73～38℃。위료능구평고LNG설비재저온배경하적풍험，통과유전산법장온도확전지－209℃。확전득도적취단손상인자곡선동하비충격시험적충격공수온도변화곡선적추세기본일치，인차확전적손상인자가이만족저온배경하LNG설비적풍험평고。
Recently, Risk-Based Inspection ( RBI) technology based on API 581 has been gradually adopted and become a new technology to determine economic feasibility and safety of equipment in petrochemical plants.Howev-er, there are limitations of applying API 581 to LNG equipment because the temperature of LNG is usually under-162℃.Low temperature brittle fracture is a major failure mode of LNG equipment need to be considered, but API code considers the temperature range of about -73~38℃to evaluate the brittle fracture damage factor.To evalu-ate the risk of LNG equipment in low temperature environment, the temperature region was extended to about -209℃with genetic algorithm.The tendency of extended brittle fracture damage factor ( BFDF) curve was similar with the curve of impact energy against temperature change in Charpy impact tests.Therefore, the extend BFDF can satisfy the risk assessment of LNG equipment in cryogenic environment.