摘要
为了研究泥沙特性与NaCl浓度对45#钢材料磨蚀的影响及机理,采用超声振动空化装置配合自主研发的泥沙搅拌装置作为磨蚀试验设备,对45#钢材料进行磨蚀性能试验。运用失重法对比分析了相同磨蚀条件下有、无NaCl时的磨蚀量大小,并探讨了各自的磨蚀机理。研究结果表明:NaCl的加入对于45#钢材料磨蚀性能有较大的影响,且其磨蚀影响存在某个特定的门槛浓度。当NaCl浓度小于3. 5%时,材料磨蚀量增加速率较大,超过3. 5%后增加速率趋缓。45#钢磨蚀过程存在的临界泥沙粒径在0. 05~0. 07 mm之间。NaCl的加入引起的泥沙颗粒对金属的力学磨蚀作用与NaCl对金属的电化学腐蚀之间的协同作用大于由于水体黏滞性引起的细颗粒泥沙对金属磨蚀的抑制作用。研究成果能够为优化设计水轮机体型提供依据,对电站在合适的工况下正常运行和维修具有指导意义。
In order to study the impacts from sediment behavior and concentration of NaCl on the abrasion of the No.45 steel and the relevant mechanism,an abrasion performance experiment is made on the No.45 steel by means of taking the ultrasonic vibration cavitation device integrated with an independently-developed sediment mixer.The abrasion degrees under the same abrasion condition with and without NaCl are compared with weight-loss method,and then the mechanisms of both of them are discussed.The study result show that larger impact from adding NaCl is there on the abrasion performance of the No.45 steel material,meanwhile,a specific threshold concentration of NaCl is there for the impact on the abrasion.When the concentration of NaCl is less than 3.5%,the increasing rate of the abrasion on the material is larger,which tend to slowdown when the concentration of NaCl is over 3.5%.The critical particle size of sediment within the abrasion process of No.45 steel is between 0.05~0.07 mm.The cooperative effect between the mechanical abrasion effect from sediment on metal cause by adding NaCl and the electrochemical corrosion from NaCl on metal is larger than the restricting effect from fine sediment caused by viscosity of water body on the abrasion of metal.This study can provide a basis foroptimizing the design of the shape of hydro-turbine and has a guiding significance for the normal operation and maintenance of hydropower station under an appropriate operation condition.
作者
张辉
缑文娟
ZHANG Hui;GOU Wenjuan(Key Laboratory of Water Conservancy and Water Resources of Anhui Province,Anhui&Huaihe River Institute of Hydrautic Research,Bengbu 233000,Anhui,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University,Tianjin 300072,China)
出处
《水利水电技术》
CSCD
北大核心
2018年第10期186-191,共6页
Water Resources and Hydropower Engineering
基金
国家自然科学基金青年科学基金项目(51409187)
关键词
两相流
门槛浓度
临界泥沙粒径
协同作用
抑制作用
two-phase flow
threshold concentration
critical particle size of sediment
cooperative effect
restricting effect
