【摘要】 针对燃气轮机的高速密封工况，基于磁性液体的密封原理，设计一种高速磁性液体密封结构。对4种不同酯基磁性液体的流变性能进行表征，选择合适的磁性液体。基于一般磁性液体的伯努利方程，推导出同时考虑转速和温度的磁性液体密封的理论耐压公式，并采用有限元分析软件数值模拟密封装置间隙内的磁场分布。搭建高速磁性液体密封试验台，研究高速磁性液体密封结构在有无冷却模块作用下的密封性能。结果表明，磁性液体旋转密封装置加装冷却模块后，极靴处温度下降了31℃,耐压值提高了33%。根据试验结果设计了将极齿开在轴上的优化结构，并与极齿开在极靴上的结构的密封性能进行对比。结果表明：极齿开在轴上且有冷却模块作用的密封结构具有优异的密封性能，可以有效平衡高速时的离心力和温度影响，在转速8 500 r/min(折合线速度17.79 m/s)的高速工况下，仍能保持167 kPa的耐压值。更多还原

【Abstract】 A high-speed magnetic liquid sealing structure was designed based on the sealing principle of magnetic liquids to address the high-speed sealing conditions in gas turbines.The rheological properties of four different ester-based magnetic fluids were characterized, and the most suitable ones were selected.Using the general Bernoulli equation of magnetic liquids, a theoretical pressure resistance formula for the magnetic liquid rotary seal was derived considering both speed and temperature.The magnetic field distribution in the clearance of the sealing device was numerically simulated by finite element analysis software.A high-speed magnetic liquid seal test bench was set up to evaluate the sealing performance of the structure both with and without the cooling module.The result shows that after installing a cooling module on the magnetic liquid rotary seal device, the temperature at the pole shoe decreases by 31 ℃,and the pressure resistance value increases by 33%.Based on the experimental results, an optimized structure featuring pole teeth on the shaft was designed, and its sealing performance was compared compared to that of a structure with pole teeth on the pole shoe.It is found that the sealing structure with pole teeth on the shaft and a cooling module achieves a superior sealing effect, which can effectively balance the centrifugal force and temperature effects at high speed.It can still maintain a pressure resistance value of 167 kPa under high-speed conditions of 8 500 r/min(equivalent linear velocity of 17.79 m/s).更多还原