The seismic response of an isolated vertical, cylindrical, extra-large liquefied natural gas （LNG） tank by a multiple friction pendulum system （MFPS） is analyzed. Most of the extra-large LNG tanks have a fundament...The seismic response of an isolated vertical, cylindrical, extra-large liquefied natural gas （LNG） tank by a multiple friction pendulum system （MFPS） is analyzed. Most of the extra-large LNG tanks have a fundamental frequency which involves a range of resonance of most earthquake ground motions. It is an effective way to decrease the response of an isolation system used for extra-large LNG storage tanks under a strong earthquake. However, it is difficult to implement in practice with common isolation bearings due to issues such as low temperature, soft site and other severe environment factors. The extra-large LNG tank isolated by a MFPS is presented in this study to address these problems. A MFPS is appropriate for large displacements induced by earthquakes with long predominant periods. A simplified finite element model by Malhotra and Dunkerley is used to determine the usefulness of the isolation system. Data reported and statistically sorted include pile shear, wave height, impulsive acceleration, convective acceleration and outer tank acceleration. The results show that the isolation system has excellent adaptability for different liquid levels and is very effective in controlling the seismic response of extra-large LNG tanks.展开更多
The total storage of full containment LNG storage tanks is very huge. Once the tank rupture or leakage, the consequence will be unimaginable. Therefore it is necessary to perform the risk-based inspection （RBI） and ...The total storage of full containment LNG storage tanks is very huge. Once the tank rupture or leakage, the consequence will be unimaginable. Therefore it is necessary to perform the risk-based inspection （RBI） and evaluation on LNG storage tanks, and the analysis on LNG storage tanks failure possibility is especially important in the RBI. Recently, Risk-based inspection （RBI） technology based on API 581 is gradually adopted and has become a new technology to determine economic feasibility and safety of equipment in petrochemical plants. However, there are limitations of applying API 581 to LNG equipment because of the unique structure of LNG storage tank （the metal inner tank and concrete outer tank）. Therefore, a failure probability calculation model suitable for full containment LNG storage tanks is proposed. The domestic inner tank is usually made of 9%Ni, and its failure possibility can be calculate based on API581; the outer tank is usually made of pre-stressed concrete, and the failure possibility of structure durability can be calculated by the method of fuzzy mathematics ; Then the failure possibility of the inner tank and the outer tank will be comprehensive considered by using cellulose model. Finally, by citing a real example, it also detailedly introduces the application of this proposed calculation model in the failure possibility analysis of full containment LNG storage tanks. This study provides a new approach for the evaluation of failure possibility on full containment LNG storage tanks.展开更多
基金Foundation of Basic Research Program of State Key Laboratory from Ministry of Science and Technology of China Under Grant No. SLDRCE10-D-01Foundation of Shanghai Engineering Technical Research Centre Under Grant No. 10DZ2252000
文摘The seismic response of an isolated vertical, cylindrical, extra-large liquefied natural gas （LNG） tank by a multiple friction pendulum system （MFPS） is analyzed. Most of the extra-large LNG tanks have a fundamental frequency which involves a range of resonance of most earthquake ground motions. It is an effective way to decrease the response of an isolation system used for extra-large LNG storage tanks under a strong earthquake. However, it is difficult to implement in practice with common isolation bearings due to issues such as low temperature, soft site and other severe environment factors. The extra-large LNG tank isolated by a MFPS is presented in this study to address these problems. A MFPS is appropriate for large displacements induced by earthquakes with long predominant periods. A simplified finite element model by Malhotra and Dunkerley is used to determine the usefulness of the isolation system. Data reported and statistically sorted include pile shear, wave height, impulsive acceleration, convective acceleration and outer tank acceleration. The results show that the isolation system has excellent adaptability for different liquid levels and is very effective in controlling the seismic response of extra-large LNG tanks.
文摘The total storage of full containment LNG storage tanks is very huge. Once the tank rupture or leakage, the consequence will be unimaginable. Therefore it is necessary to perform the risk-based inspection （RBI） and evaluation on LNG storage tanks, and the analysis on LNG storage tanks failure possibility is especially important in the RBI. Recently, Risk-based inspection （RBI） technology based on API 581 is gradually adopted and has become a new technology to determine economic feasibility and safety of equipment in petrochemical plants. However, there are limitations of applying API 581 to LNG equipment because of the unique structure of LNG storage tank （the metal inner tank and concrete outer tank）. Therefore, a failure probability calculation model suitable for full containment LNG storage tanks is proposed. The domestic inner tank is usually made of 9%Ni, and its failure possibility can be calculate based on API581; the outer tank is usually made of pre-stressed concrete, and the failure possibility of structure durability can be calculated by the method of fuzzy mathematics ; Then the failure possibility of the inner tank and the outer tank will be comprehensive considered by using cellulose model. Finally, by citing a real example, it also detailedly introduces the application of this proposed calculation model in the failure possibility analysis of full containment LNG storage tanks. This study provides a new approach for the evaluation of failure possibility on full containment LNG storage tanks.
