回流孔面积大小对自吸泵性能影响的研究

Study on Reflux Hole Size′s Influence on the Self-priming Pump Performance

为了研究自吸泵回流孔面积对自吸泵性能的影响,以ZX80-65型外混式自吸泵为研究对象,设计5种不同回流孔面积方案,通过计算流体力学的分析方法对自吸泵内部流动进行数值模拟,对其回流孔两侧压差、回流孔回流量及外特性曲线进行分析。研究结果表明,回流孔的存在对泵正常工作时的流动特性影响较大。在自吸阶段,适当增大回流孔的面积,可增大蜗壳回流量,在不改变泵基本性能的前提下有助于提升泵的自吸性能。在大流量工况下,增大回流孔的面积导致泄漏量增加,从而增大了泵的容积损失,导致自吸泵效率下降。在额定工况下,回流孔面积越大,回流孔两侧压差越趋近于0,其泄漏损失越小。对于特定的自吸泵,存在一个最佳的回流孔开孔位置。

In order to study on the self-priming pump reflux hole size′s influence on the self-priming pump performance,the author will take ZX80-65 self-sucking pump as the research subject to design five kinds of different reflux hole size schemes,then,adopt he computational fluid mechanics method to simulate the numerical value of internal flow in the self-priming pump,finally,analyze the pressure difference between two sides of reflux hole,reflux hole backflow and external characteristic curve.According to the research results,the reflux hole has a large influence on the flow characteristics during the normal operation of the pump.In the self-priming phase,it is good for increasing the volute reflux quantity and enhance the self-priming performance of the pump in the premise of not changing the basic performance of pump when the reflux hole size is increased appropriately.In case of heavy traffic conditions,the leakage rate will be increased by the enlarged reflux hole size,as a result,the volumetric loss of pump is increased and the self-priming pump efficiency is decreased.Under the rated working conditions,the pressure difference between two sides of reflux hole will increasingly get close to zero when the reflux hole size is larger and larger,in such case,the leakage loss will be accordingly small.When it comes to the specific self-priming pump,there is an optimal opening position for reflux hole.