超大型FPSO出坞靠泊环境载荷计算分析

Calculation of Environmental Load for a Large FPSO Undocking

船舶出坞是大型船舶建造过程中必不可少的工艺环节,目前国内外对于船舶出坞的问题仍然采用传统的经验方法计算出坞时的环境载荷,以确定出坞时所需的辅助拖轮功率和数量。本文根据船舶出坞标准要求,结合船坞布置形式及出坞时的气象水文条件,采用OCIMF介绍的数学模型,求解船舶在出坞时从90°到0°过程中,在不同风、浪、流组合下的环境载荷,并重点分析了风、浪、流对船舶出坞的影响。使用数值分析法对相同环境条件进行模拟计算,将计算结果和OCIMF方法计算结果进行对比分析,验证了OCIMF方法计算结果的可靠性,并以计算结果确定超大型FPSO出坞时所需辅助拖轮功率和数量。

Vessel undocking is an essential process in the construction of large vessel.Nowadays,the traditional empirical method is usually used to calculate the environmental load during large vessel undocking and to determine the power and number of assistant tug in the world shipbuilding industry.Firstly,the OCIMF mathematical model for solving the environmental load problem is established in this paper.According to the location of the dry dock and the meteorological and hydrological conditions while undocking,the environmental load of a large FPSO with the speed of the wind,wave and current combination from O°to 90°are calculated by using the OCIMF formula method,and then the influence of the wind,wave and current load on large FPSO are analyzed.Secondly,the environmental load is calculated by using numerical simulation calculation method based on the same environment conditions.Through comparing the analysis results between the two calculation methods,the reliability of using the OCIMF formula method is testified,and the maximum environmental load is determined.Lastly,as a result the undocking plan and the power and number of assistant tugs arc finally determined.