核电厂应急柴油机橡胶膨胀节破裂原因分析

Analysis of the Causes of Rubber Expansion Joint Rupture in Emergency Diesel Engines in Nuclear Power Plant

针对核电厂应急柴油机冷却水回路橡胶膨胀节破裂问题,采用宏观与微观检查、成分分析、力学性能测试、化学分析等技术手段,探究了其失效机制。结果表明,该橡胶膨胀节材料选择存在一定问题,内层丁腈橡胶材料在较高温度下的含乙二醇冷却液中长期使用,产生了溶胀与渗入问题。乙二醇与钢丝编织层直接接触而出现腐蚀,最终导致橡胶膨胀节在内部压力下发生破裂。

Based on macroscopic and microscopic examination,composition analysis,mechanical property testing,and chemical analysis,the failure mechanism of the rubber expansion joint rupture in the emergency diesel engine cooling water loop of a nuclear power plant was investigated.The results indicate that there were certain issues with the material selection for the rubber expansion joint.The inner layer of nitrile rubber material,when exposed to a glycol-containing cooling fluid at high temperatures over an extended period,experienced swelling and permeation.Direct contact between the glycol and the steel wire braided layer led to corrosion,ultimately resulting in the rupture of the rubber expansion joint under internal pressure.