液力透平机械密封泄漏的原因分析及改进

Cause Analysis and Improvement of Mechanical Seal Leakage of Hydraulic Turbine

某柴油加氢改质装置液力透平采用旋转式串联机械密封和基于API标准的PLAN 53B冲洗方案的辅助密封系统,在试运行时发现机械密封泄漏严重。通过对机械密封结构和辅助密封冲洗系统的分析,指出机械密封泄漏的主要原因是,泵送环扬程不足及换热器管路阻力过大,旋转式串联密封动环波动影响摩擦热和介质传导热的排出,高温下隔离液会气化等。通过对换热器和泵送环的改造,降低了隔离液腔和密封腔温度;将旋转式串联密封改为静止式双端面密封,提高了换热效率;采用高沸点隔离液,解决了隔离液的气化问题。机械密封改造后,取得了较好的密封效果,且降低了液力透平电机的负荷。

The serious mechanical seal leakage is found ior the hydrauhc turbine o~ a mesel nyarogenanon moumcauon device during the test run. The hydraulic turbine uses the rotating tandem mechanical seal and the auxiliary sealing system with PLAN 53B irrigation scheme based on API standard. Through the analysis on the mechanical seal structure and the auxiliary flushing system, the main causes of the mechanical seal leakage were pointed out, which was that the pump ring head of the mechanical seal was insufficient and the heat exchanger pipe resistance was too large, the fluctuation of the ro- tary series sealing ring affected the dynamic discharge of friction heat and medium transfer heat, and the spacer fluid was vaporized at high temperature. Through the transformation of heat exchanger and pump ring, the temperature in the liquid separation chamber and the sealing cavity is reduced. By transforming the rotary series sealing into double end face static seal, the heat exchange efficiency is improved. By using high boiling point spacer fluid, the problem of gasification of spacer fluid is solved. The transformed mechanical seal achieves a better sealing effect, and the load of hydraulic turbine motor is reduced.