浅水新型FPSO张紧式多点系泊系统时域分析

Time Domain Analysis of Taut Multi-point Mooring System for New Concept FPSO in Shallow Waters

为了确定新型圆角倒棱台形FPSO(IQFP)的系泊系统方案,进一步研究浅水张紧式多点系泊系统的基本特性,考虑风、浪、流的联合作用,对IQFP张紧式多点系泊系统进行了作业工况和生存工况下的时域耦合运动响应分析,得到了浮体运动和系缆张力的时历曲线。研究结果表明,浮体的水平偏移和系缆的张力都符合规范要求,系泊性能优良。在此基础上,通过谱密度分析,从能量角度对浅水张紧式系泊特性进行分析。分析结果表明,与悬链线式系泊相比,采用张紧式多点系泊的浅水IQFP的浮体低频运动响应很微小,而系缆张力中波频力和低频力所占比例几乎相同,从而进一步验证了张紧式多点系泊系统适用于浅水海域的优越性。

To determine the final solution of mooring system applied to the new concept FPSO?IQFP ( Invert?ed Fillet Quadrangular Frustum Pyramid Shaped FPSO) and further evaluate the characteristics of the taut multi?point mooring system in shallow waters, the time domain dynamic simulation has been conducted under the opera?tion condition and the survival condition combined with the simultaneous effect of the wind, wave and current?The time history responses of the motions of the vessel and the tensions of the mooring lines are obtained?The analyses indicate that both the vessel offsets and the mooring line tensions satisfy the code requirements and the mooring sys?tem present excellent performance as well?The corresponding spectral density distributions were calculated, and then the preliminary research on the mooring characteristics was conducted from energy perspective?The results show that obvious difference from the catenary mooring system is demonstrated that the vessel produces small low frequency motion responses while the mooring line tensions possess the approximately same proportion in both the wave frequency responses and the low frequency ones?The study provides further evidence that the taut mooring sys?tem is more superior in the shallow water compared to the catenary mooring system.