高温铅铋轴流泵叶轮冲磨蚀特性研究

Study on Erosion Characteristics of the High Temperature Lead-Bismuth Axial-Flow Pump Impeller

为研究铅铋轴流泵叶轮冲磨蚀特性,基于液态铅铋的冲磨蚀破坏机理分析,利用边界层理论建立冲磨蚀数学模型,采用SST k-ω湍流模型对0.8Q_(d)、1.0Q_(d)和1.2Q_(d)三种方案下泵内流动进行数值计算,获得了叶片冲磨蚀分布及壁面流速、流态、壁面熵产率与冲磨蚀的影响关系。结果表明:高冲磨蚀区域主要分布在叶片进口边靠近泵壳一侧;随铅铋泵入口流量增加和壁面流态紊乱加剧,叶片受冲磨蚀影响增大;当液态铅铋的最大流速不高于10m/s时,叶片受冲磨蚀影响较小,而最大流速高于10m/s时,叶片表面冲磨蚀急剧加重;叶片表面高冲磨蚀区域是高壁面熵产率主要分布区域,且液态铅铋的冲磨蚀行为与壁面熵产率呈正相关关系。

In order to study the impeller erosion characteristics of the lead-bismuth axial flow pump,based on the analysis of the erosion damage mechanism of the liquid lead-bismuth,the mathematical model of erosion was established by using the boundary layer theory,and the SST k-ω turbulence model was used to numerically calculate the flow in the pump under three scenarios of 0.8Q_(d),1.0Q_(d) and 1.2Q_(d),and the relationship between the distribution of the blade erosion and the wall flow velocity,flow pattern,wall entropy yield and erosion was obtained.The results show that the high impact erosion area is mainly distributed at the inlet edge of the blade near the pump housing.With the increase of the liquid lead-bismuth inlet flow and the increase of the wall flow disorder,the impact of the blade erosion increases.When the maximum flow velocity of the liquid lead-bismuth is not higher than 10 m/s,the impact of blade erosion is small,but when the maximum flow velocity is higher than 10 m/s,the blade surface erosion increases sharply.The high impact erosion area on the blade surface is the main distribution area of the high wall entropy yield,and the impact erosion behavior of the liquid lead-bismuth is positively correlated with the wall entropy yield.