Cavitation Characteristics during Startup Process of a Condensate Pump with Splitter Blades

The present study aim s to describe characteristics of cavitation du ring the startup process of a condensate pump. The pump is featured by an impeller equipped with five splitter blades. A computational fluid dynamics (CFD) work w as conducted to plumb the evolution of cavitation in the pump. Effect of the volumetric flow r ate on instantaneous cavitation patterns as the rotational speed of the pump increase d was analyzed . The results show that high resistance to cavitation of the pump depends greatly on large area of the impeller eye, which i s related to the deployment of th e splitter blades . The splitter blades are insignificantly affected by cavitation. During the startup process, both the pump head and the pump efficiency vary drastically , which is insensitive to the flow rate . A t a net positive suction head NPSH of 2.0 m , high flow rates are responsible for intensified cavitation. H igh volume fraction of cavitation arises near the inlet of long blades . As the rotational speed increases, the evolution of cavitation is featured by intermittency and diversified cavity patte rns. Furthermore, t he sum of the volume fraction of cavitation fluctuates with continuously increasing rotational speed.