基于热流固耦合密封环-液膜多体结构的性能分析

Performance Analysis of Seal Ring-Liquid Film Multi-body Structure Based on Thermal-Fluid-Solid Coupling

机械密封的性能对海洋核心设备海底混输泵的热控效率以及稳定运行有着重要影响。针对混输泵工作状态与机械密封服役环境,建立密封环-液膜多体结构三维模型,考虑热效应、力效应和流体效应等多场协同作用,利用热流固耦合数值仿真技术,研究密封环-液膜多体结构在模拟实际工况下的性能变化规律,得到密封环-液膜多体结构在不同工况下的润滑特性、力学特性以及温度特性。结果表明:在密封环-液膜的多体结构中,密封环最大变形量和最高温度都出现在螺旋槽区域;随转速和压力的增加密封开启力和泄漏量增加,但转速的影响明显大于压力;压力对应力的影响明显大于转速,特别是在压力超过6 MPa后密封端面的接触压力较为不均匀;由于对流换热和气流黏性剪切影响,转速对密封端面温度影响大于压力,尤其在500 r/min低转速区域,密封环-液膜结构的温度突破了75℃,不同径向位置温度差异性也十分明显,对机械密封会造成损伤。

The performance of mechanical seal has an important influence on the thermal control efficiency and stable operation of marine core equipment of submarine hybrid pump.Based on the working state of the hybrid pump and the service environment of the mechanical seal, the three-dimensional model of seal ring-liquid film multi-body structure was established.Considering the multi-field synergy of thermal effect, force effect and fluid effect, the performance change law of seal ring-liquid film multi-body structure under simulated actual working conditions was studied by using thermal-fluid-solid coupling numerical simulation technology, and the lubrication characteristics, mechanical characteristics and temperature characteristics of seal ring-liquid film multi-body structure under different working conditions were obtained.The results show that in the multi-body structure of the seal ring-liquid film, the maximum deformation and maximum temperature of seal ring appear in the spiral groove area.With the increase of speed and pressure, the seal opening force and leakage increase, but the influence of speed is obviously greater than that of pressure.The influence of pressure on stress is significantly greater than that of speed, especially when the pressure exceeds 6 MPa, the contact pressure of sealing face is relatively uneven.Due to the effect of convective heat transfer and air flow viscous shear, the speed has a greater effect on the temperature of the seal end face than the pressure, especially in the low speed region of 500 r/min, the temperature of the ring-liquid film multi-body structure exceeds 75 ℃,and the temperature difference at different radial positions is also very obvious, which will cause damage to the mechanical seal.