海洋平台上部组块往复式压缩机支撑结构振动评估

Vibration Evaluation of Support Structure for Offshore Platform Topside Excited Under Reciprocating Compressor

针对某海洋平台新增往复式压缩机结构改造振动评价问题,提出压缩机支撑结构的振动评价准则,并对分析使用的模型尺度进行探讨。采用ANSYS软件对该平台上部组块进行有限元建模,并截取2种不同尺度的局部模型,进而开展压缩机支撑结构频率、振动水平评价,分析设计方案的可行性,并给出不同局部模型的计算效率和精度。结果表明:新增压缩机改造方案可行,支撑结构频率和振动水平均满足评价准则;局部模型1具有良好的精度,可大幅提高计算效率,可在结构基础设计时替代整体模型用于振动评估分析;局部模型2的计算误差较大,即在进行平台振动评估时不能采用过小的局部模型进行分析。

Aiming at the vibration evaluation of the support structure for a new reciprocating compressor installed on an offshore platform topside,the vibration evaluation criteria of the compressor support structure are proposed and the size of the model used in the analysis is discussed.The whole finite element model of the platform topside is established using ANSYS software and two partial models around the reciprocating compressor with different sizes are intercepted from the overall model,named PM1and PM2.The evaluation of the frequency and vibration response of the compressor support structure is carried out to analyze the feasibility of the design scheme,and the calculation efficiency and accuracy of the two partial models are discussed.The results show that:the frequency and vibration levels of the supporting structure meet the evaluation criteria,that is,the design scheme is feasible;PM1is of good accuracy and can greatly improve the calculation efficiency and can be used for vibration evaluation instead of the overall model during the structural foundation design;PM2causes a larger calculation error,which is not recommended to use in the vibration evaluation of the offshore platform.