基于载荷分布的潜水轴流泵叶轮与导叶水力设计

对潜水轴流泵进行三维反问题设计,以水力效率为设计目标,提出叶轮、导叶适合的载荷分布形式。通过正交试验设计、单因素分析和数值模拟的方法研究载荷参数对潜水轴流泵内外特性的影响,得到水力效率较优的载荷分布形式:叶轮叶片为前载型,导叶叶片为轮毂中载、轮缘前载型。具体的载荷参数取值范围:对于叶轮,斜率取值范围为-1~0,前载点取值范围为0.25~0.45,后载点取值范围为0.55~0.75;对于导叶,轮毂斜率在0附近取值,轮缘斜率取值范围为0~0.75,轮毂前载点取值范围为0.25~0.45,轮缘前载点在0.25附近取值,轮毂后载点取值范围为0.55~0.75。叶轮设计中发现:前载型叶片对原泵叶根尾缘的二次流有改善作用。导叶设计中发现:由于潜水轴流泵导叶的扩散式结构特点,导叶近壁面易出现分离涡,轮毂中载、轮缘前载型叶片能够有效地抑制导叶近壁面的涡分离。

Hydraulic Design of Submersible Axial-flow Pump Based on Blade Loading Distributions

A three-dimensional inverse design of a submersible axial-flow pump was performed and the loading distributions of both the impeller and guide vane were studied. The hydraulic efficiency was set as the design objective, the optimized loading distributions of the impeller and the guide vane were attained based on numerical simulation results. The orthogonal experimental design, univariate analysis and the numerical simulation were used to study the influence of the loading distribution parameters on both the flow characteristics and hydraulic performance of the submersible axial-flow pump. In order to get superior hydraulic efficiency, the impeller should be fore loaded on both the hub and the shroud, and the guide vane should be mid loaded for the hub and fore loaded for the shroud. Specifically, the range of the loading parameters were as follows: for the impeller blades, the loading slope was in the range of -1~0, which was a front loaded kind, the front loading point was in the range of 0.25~0.45, and the after loading point was in the range of 0.55~0.75;for the guide vane, the hub slope was close to 0 which was a mid loaded kind, the shroud slope was ranged from 0 to 0.75 which was after loaded kind, the hub front loading point was in the range of 0.25~0.45, the shroud front loaded point was close to 0.25, the hub after loading point was in the range of 0.55~0.75. In the impeller design, it was found that the front loaded blade can suppress secondary flows in the blade outlet near the hub. Due to the diffusion structure of the guide vane, the seperation vortex near the wall was inclined to happen. In the design of guide vane, it was found that the separation vortex near the wall was suppressed in the hub-mid-loaded and shroud-fore-loaded diffuser. The impeller and guide vane with the above loading distributions were matched with each other, which can give a better design outcome for the submersible axial-flow pump.