Much attention should be paid to a large FPSO moored permanently in an oil field with water depth of only about 20 m, since shallow water effects on the hydrodynamics may bring about collision and damage. A 160kDWT FP...Much attention should be paid to a large FPSO moored permanently in an oil field with water depth of only about 20 m, since shallow water effects on the hydrodynamics may bring about collision and damage. A 160kDWT FPSO with a permanent soft yoke mooring system is investigated with various shallow water depths and focuses are the low frequency surge motion and mooring load. Computation for the FPSO system is made based on linear 3-D potential fluid theory and time-domain numerical simulation method. Corresponding model test is carried out in the ocean engineering basin of Shanghai Jiao Tong University. It is shown that, in the surge natural period, low frequency surge motion and mooring force increase remarkably with the decrease of water depth. Especially, the smaller the ratio of water depth and draught is, the quicker the increase is. The shallow water effects should be taken into account carefully for determining the design load of a single point mooring system.展开更多
A three-dimensional method of calculating wave loads of turret moored FPSO (Flo ating Production Storage and Offloading) tankers is presented. The linearized restoring forces acting on the ship hull by the mooring sys...A three-dimensional method of calculating wave loads of turret moored FPSO (Flo ating Production Storage and Offloading) tankers is presented. The linearized restoring forces acting on the ship hull by the mooring system are calculated according to the catenary theory, which are expressed as the function of linear stiffness coefficients and the displacements of the upper ends of mooring chains. The hydrodynamic coefficients of the ship are calculated by the three-dimensional potential flow theory of the linear hydrodynamic problem for ships with a low forward speed. The equations of ship motions are established with the effect of the restoring forces from the mooring system included as linear stiffness coefficients. The equations of motions are solved in frequency domain, and the responses of wave-induced motions and loads on the ship can be obtained. A computer pro gram based on this method has been developed,and some calculation examples are illustrated. Analysis results show that the method can give satisfying prediction of wave loads.展开更多
Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs（Floating Production Storage and Offloading） suffer from the ...Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs（Floating Production Storage and Offloading） suffer from the environment loads, including the freak wave. The freak waves were generated based on the improved phase modulation model, and the coupling model of FPSO-SPM（Single Point Mooring） was established by considering internal-turret FPSO and its mooring system. The dynamic response characteristics of both FPSO and SPM affected by the freak wave were analyzed in the time domain. According to the results, the freak waves generated by original phase modulation model mainly affect the 2nd-order wave loads. However, the freak waves which are generated by random frequencies phase modulation model affect both 1st-order and 2nd-order wave loads on FPSO. What is more, compared with the irregular waves, the dynamic responses of mooring system are larger in the freak waves, but its amplitude lags behind the peak of the freak wave.展开更多
为研究浮式生产储卸油船(Floating Production Storage and Offloading, FPSO)在码头舾装期间系泊系统的安全性,对某30万吨级FPSO的码头系泊系统在台风条件下单系泊缆破断后的安全性进行分析。基于模拟结果,分别计算了受力最大和受力第...为研究浮式生产储卸油船(Floating Production Storage and Offloading, FPSO)在码头舾装期间系泊系统的安全性,对某30万吨级FPSO的码头系泊系统在台风条件下单系泊缆破断后的安全性进行分析。基于模拟结果,分别计算了受力最大和受力第二大的缆绳破断后,码头系泊系统中剩余缆绳的张力和安全系数。结果表明:缆绳破断后,剩余缆绳的安全系数总体是减小的,但有部分剩余缆绳的最小安全系数有明显的上升;在系泊系统完整和破断条件下,安全系数最小的缆绳均为同一组缆绳;在一根缆绳破断后,码头系泊系统仍具有足够安全性。研究成果可为FPSO码头系泊系统安全评估提供一定参考。展开更多
利用水动力分析软件AQWA研究了内转塔式单点系泊参数对海上浮式生产储油船FPSO(floating production,storage and affcoading system)系统动力效应的影响特性,定量分析了内转塔位置、系泊缆材料分布、系泊缆预张力、系泊缆数量、系泊缆...利用水动力分析软件AQWA研究了内转塔式单点系泊参数对海上浮式生产储油船FPSO(floating production,storage and affcoading system)系统动力效应的影响特性,定量分析了内转塔位置、系泊缆材料分布、系泊缆预张力、系泊缆数量、系泊缆布置形式等参数对FPSO系统动力效应的影响,对每个系泊参数采取多个特征量进行比较分析,计算结果表明:转塔位置距船艏柱25%Lpp时风标效应及定位效果最好,多成分系泊缆材料分布采取下端钢链9%、聚酯缆90%、上端钢链1%时,系泊缆数量取9根且为3组×3根/组布置时定位效果最好,缆绳受力最小.以FPSO水平偏移量与系泊缆的安全系数为目标,提出了一套系泊系统的优选方案,计算结果表明系泊性能优良,与初步设计方案相比有了显著地提高.文中的计算及分析结果对内转塔式FPSO系泊系统的设计具有一定指导意义.展开更多
基金This work was financially supported bythe National High Technology and Development Programof China (Grant No.2004AA616180)
文摘Much attention should be paid to a large FPSO moored permanently in an oil field with water depth of only about 20 m, since shallow water effects on the hydrodynamics may bring about collision and damage. A 160kDWT FPSO with a permanent soft yoke mooring system is investigated with various shallow water depths and focuses are the low frequency surge motion and mooring load. Computation for the FPSO system is made based on linear 3-D potential fluid theory and time-domain numerical simulation method. Corresponding model test is carried out in the ocean engineering basin of Shanghai Jiao Tong University. It is shown that, in the surge natural period, low frequency surge motion and mooring force increase remarkably with the decrease of water depth. Especially, the smaller the ratio of water depth and draught is, the quicker the increase is. The shallow water effects should be taken into account carefully for determining the design load of a single point mooring system.
文摘A three-dimensional method of calculating wave loads of turret moored FPSO (Flo ating Production Storage and Offloading) tankers is presented. The linearized restoring forces acting on the ship hull by the mooring system are calculated according to the catenary theory, which are expressed as the function of linear stiffness coefficients and the displacements of the upper ends of mooring chains. The hydrodynamic coefficients of the ship are calculated by the three-dimensional potential flow theory of the linear hydrodynamic problem for ships with a low forward speed. The equations of ship motions are established with the effect of the restoring forces from the mooring system included as linear stiffness coefficients. The equations of motions are solved in frequency domain, and the responses of wave-induced motions and loads on the ship can be obtained. A computer pro gram based on this method has been developed,and some calculation examples are illustrated. Analysis results show that the method can give satisfying prediction of wave loads.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51279130 and 51479134)
文摘Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs（Floating Production Storage and Offloading） suffer from the environment loads, including the freak wave. The freak waves were generated based on the improved phase modulation model, and the coupling model of FPSO-SPM（Single Point Mooring） was established by considering internal-turret FPSO and its mooring system. The dynamic response characteristics of both FPSO and SPM affected by the freak wave were analyzed in the time domain. According to the results, the freak waves generated by original phase modulation model mainly affect the 2nd-order wave loads. However, the freak waves which are generated by random frequencies phase modulation model affect both 1st-order and 2nd-order wave loads on FPSO. What is more, compared with the irregular waves, the dynamic responses of mooring system are larger in the freak waves, but its amplitude lags behind the peak of the freak wave.
文摘为研究浮式生产储卸油船(Floating Production Storage and Offloading, FPSO)在码头舾装期间系泊系统的安全性,对某30万吨级FPSO的码头系泊系统在台风条件下单系泊缆破断后的安全性进行分析。基于模拟结果,分别计算了受力最大和受力第二大的缆绳破断后,码头系泊系统中剩余缆绳的张力和安全系数。结果表明:缆绳破断后,剩余缆绳的安全系数总体是减小的,但有部分剩余缆绳的最小安全系数有明显的上升;在系泊系统完整和破断条件下,安全系数最小的缆绳均为同一组缆绳;在一根缆绳破断后,码头系泊系统仍具有足够安全性。研究成果可为FPSO码头系泊系统安全评估提供一定参考。
文摘利用水动力分析软件AQWA研究了内转塔式单点系泊参数对海上浮式生产储油船FPSO(floating production,storage and affcoading system)系统动力效应的影响特性,定量分析了内转塔位置、系泊缆材料分布、系泊缆预张力、系泊缆数量、系泊缆布置形式等参数对FPSO系统动力效应的影响,对每个系泊参数采取多个特征量进行比较分析,计算结果表明:转塔位置距船艏柱25%Lpp时风标效应及定位效果最好,多成分系泊缆材料分布采取下端钢链9%、聚酯缆90%、上端钢链1%时,系泊缆数量取9根且为3组×3根/组布置时定位效果最好,缆绳受力最小.以FPSO水平偏移量与系泊缆的安全系数为目标,提出了一套系泊系统的优选方案,计算结果表明系泊性能优良,与初步设计方案相比有了显著地提高.文中的计算及分析结果对内转塔式FPSO系泊系统的设计具有一定指导意义.
