【摘要】 低比转速离心泵由于叶轮直径大,出口宽度小,流道扩散严重等原因,导致其效率偏低且很难改善.在计算流体动力学数值模拟和模型泵性能试验基础上,分析了低比转速离心泵效率与内部流动特性之间的关系,为改善泵内流动结构和提高效率提供依据.基于以控制边界层分离为目的的流动控制技术,提出了两种新型的离心泵叶片结构,研制了新的叶轮.为便于比较分析,对新叶轮在保证原模型泵叶轮直径、出口宽度和安装尺寸等主要几何参数不变的前提下进行加工制造,并分别将常规设计的叶片、分流叶片和两种新型叶片的叶轮在同一泵体内进行试验.试验结果表明:分流叶片提高了泵在大流量区域的效率但不能拓宽流量范围,引流叶片使水泵在更大流量范围内运行,并且在整个流量范围内都显著地提高了泵效率.流动控制技术成功地改善了低比转速离心泵内部流动结构并提高了泵性能.更多还原

【Abstract】 The efficiency of a low specific-speed centrifugal pump is low,it is very difficult to improve its efficiency due to the large impeller diameter,narrowed blade width and severe diffusion in the flow passages.Based on CFD numerical simulations and performance tests,a relationship between efficiency and internal flow characteristics of a low specific-speed centrifugal pump was analyzed to establish a basis for improving the flow structure in impeller and increasing the pump efficiency.The updated impellers,which were respectively with two types of blade structure proposed by using boundary layer control techniques,were developed.In order to analyze and compare easily,the main geometric parameters of the new impellers,such as diameter,width and installation size,were consistent with the original impeller.All the experiments on pump performance were conducted in the same casing.The experimental results show that the efficiency of pumps with splitter blades is improved in large capacity region,but the flow range is not extended.The efficiency of the pump with drainage blades is improved significantly at every flow rate.Further,the maximum flow rate is extended.The flow control techniques have been applied successfully to improve the flow pattern in impellers and the pump efficiency.更多还原