大梯度温度扰动下深海连接器密封性能研究及多目标结构优化

Connection and seal between the equipment of deep-sea production system is an internationally acknowledged technological difficulty, the existing major problems of deep-sea connecter are giant size of structure, difficulties of precise guidance and centering, fatigue wear of sealing structures caused by drastic temperature fluctuation. A sealing solution of metal and rubber combination is proposed in this project, microscopic contact mechanical model of the combined sealing is built, microscope leaking behavior is analyzed, and then lack of temperature compensation ability of all-metal sealing and contact pressure degradation of all-rubber sealing are solved. Equivalent stress model of deep-sea connector in temperature filed is built, stress distribution and contact pressure change rule of the sealing structure under the drastic temperature fluctuations are investigated, relation between wear of the sealing surface and the temperature fluctuation is obtained, that the problem of fatigue wear of the sealing surface is solved; Multi-objective optimization model of deep-sea connector is built, relations among the structure parameters of the combined sealing, contact pressure and microscopic compression are analyzed, by this mean, the optimal parameters of the sealing structure and optimal angle of the sealing surface are acquired, thus the overall structure parameters of deep-sea connector is reduced; Mathematical model of parameters’ relationship of the guidance and centering structure under multiple boundary conditions is built, by which the configurations of the guidance and centering structure are determined. Therefore, the problems of the guidance and centering are solved, the reliable connection between deep-sea equipment is achieved.

深海油气田水下生产系统装备之间的精准连接及密封是国际公认的技术难题。目前深海连接器存在结构尺寸大、精准引导对中难、密封结构在大梯度温度扰动下易产生疲劳磨损等问题。提出一种在金属密封面上设有异形橡胶结构的复合密封方案，建立复合密封微观接触力学模型，分析微观泄露行为，解决金属密封温度补偿能力不足，橡胶密封接触压力低、易失效等问题。建立深海连接器温度场等效应力模型，研究密封结构在大梯度温度扰动下的应力分布和接触应力变化规律，得到密封面磨损与温度扰动之间的关系，解决密封面的疲劳磨损问题。建立深海连接器结构多目标优化模型，分析复合密封结构、接触应力与微观压缩量之间的关系，得出深海连接器最优结构参数和最佳密封面角度，从而减小深海连接器整体结构尺寸；建立深海连接装备引导对中结构在多重边界条件下结构尺寸关系的数学模型，确定引导结构构型，解决深海装备之间的精准引导对中和可靠连接的问题。

深海油气田水下生产系统装备之间的精准连接和密封是国际公认的技术难题。针对目前深海连接器密封能力弱、结构尺寸大、连接困难、海底环境下的大梯度温度扰动等问题。基于径向金属静密封原理，提出了复合卡套式、金属包覆式以及锚定式等三种在密封面上设有异形非金属结构的复合式密封结构构型。基于各构型的特点，建立复合密封微观接触力学模型，分析微观泄露行为和泄漏率；建立深海连接器结构多目标优化模型，分析复合密封结构、接触应力与微观压缩量之间的关系，得出深海连接器最优结构参数和最佳密封面角度，从而减小深海连接器整体结构尺寸；为解决金属密封温度补偿能力不足、非金属密封接触压力低易失效等问题，建立深海连接器温度场等效应力模型，得到密封结构在大梯度温度扰动下的应力分布和接触应力变化规律。通过分析影响连接器连接精度的误差影响因素，为消除最为敏感的管道的径向偏差的影响，基于以弹性力学和薄壳力学，获得了改进的连接器和管道结构在多重边界条件下径向应力和变形的关系，解决了深海装备之间的精准连接的关键问题。本研究所提出的径向金属静密封结构构型及理论分析有助于径向金属静密封技术在深海连接器领域的发展，为我国开展具有自主知识产权的深海连接装备研究提供了新的发展方向。