热网循环泵机械密封冲洗水源改造过程的研究

Research on the Water Source Transformation Process for Mechanical Seal Flushing of the Heat Supply Network Circulating Pump

我司热网循环泵密封为机械密封,型号为M74N-140,在轴间与旋转环构成极薄的液态膜,以避免介质发生泄漏。机械密封设计了机封冲洗水,用于冲洗、冷却机械密封,冲洗水由电厂闭式水提供。但设计参数与实际运行状况不符,实际运行时热网循环泵入口压力大于闭式水泵出口压力,导致热网循环水反串回闭式水系统,造成闭式水水质的恶化,以及机封冲洗水的作用失效。经多次整改,将机封冲洗水水源引自热网循环泵出口,改为自密封形式,彻底解决了机封冲洗水设计不合理的问题。

The heat supply network circulating pump seal of our company is a mechanical seal with the model of M74N-140,which forms an extremely thin liquid film between the shafts and the rotating ring to avoid medium leakage.The mechanical seal is designed with organic seal flushing water to flush and cool the mechanical seal.The flushing water is provided by the closed water of the power plant.However,the design parameters do not confonn to the actual operating conditions.In the actual operation,the inlet pressure of the heat supply network circulating pump is higher than the outlet pressure of the closed water pump,resulting in the reverse flow of the heat supply network circulating water back to the closed water system,resulting in the deterioration of the closed water quality,and the failure of the role of the mechanical seal flushing water.After many times of rectification,the water source for washing the mechanical seal was introduced from the oudet of the circulating pump of the heat supply network to the self sealing form,which completely solved the problem of unreasonable design of the washing water for the mechanical seal.