汽轮机进汽阀U型密封高温强度与密封性能分析  

Analysis on High Temperature Strength and Sealing Behavior of U-type Seal in Steam Turbine Valves

作　　者：毛剑峰[1] 张军辉 王炜哲[1] 陈汉平[1] 

机构地区：[1]上海交通大学机械与动力工程学院动力机械与工程教育部重点实验室,上海市闵行区200240 [2]上海电气电站集团,上海汽轮机厂设计处,上海市闵行区200240

出　　处：《中国电机工程学报》2013年第20期104-110,18,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50906049);机械系统与振动国家重点实验室基金项目(MSV201115)~~

摘　　要：U型密封因其优越的密封性能而被广泛应用在超超临界汽轮机进汽阀门中。随着运行参数(温度,压力)不断提升,U型密封承受的蠕变越发严重。为了研究U型密封在高参数运行条件下的蠕变强度与密封性能,引用经过时间硬化修正的Norton-Bailay蠕变本构方程和基于孔洞长大理论的多轴蠕变模型,分析计算了汽轮机进气阀U型密封2 105 h工作时域内接触面位置、接触应力和蠕变多轴度因子的变化规律。结果表明:随蠕变时间增加,U型密封的接触应力下降明显;U型密封的关键部位受到较大多轴应力影响,并产生较大的Cocks-Ashby蠕变等效应变,试验结果与预测结果一致。U-type seal has been widely used in the inlet valves of ultra-supercritical steam turbines due to its superior sealing performance.However,the U-type seal bears greater creep deformation with the increase of the operational parameters（T,P）.In order to investigate the creep strength and sealing performance of the U-type seal,the modified time-hardening Norton-Bailay constitutive equation and multiaxial cavity growth model were employed in the calculation.Furthermore,the variation of contact position,contact stress and multiaxial factor of U-type seal of steam turbine valve were analyzed under 0.2 million creep hours.The results illustrate that the contact stress of U-type seal significantly reduces with the creep hours increases.Some key areas of U-type seal suffer great multi-axial state of stress,and then huge Cock-Ashby equivalent strain is produced.The experimental result is consistent with predicted result.

关 键 词：汽轮机 进汽阀 U型密封 高温蠕变 

分 类 号：TH140[一般工业技术—材料科学与工程]