Flow And Structural Analysis Of Double-suction Pump Unit With Double-channel Impeller

Due to its strong flow capacity and anti-clogging properties,double-channel with double-suction pump has been widely applied to wastewater treatment and petrochemical industry etc,mainly used to pump the multiphase flow.This kind of pump not only is greatly different in flow channel and structure features to conventional centrifugal pump,but also in flow and structural mechanical properties.Up to now,the design for double-channel with double-suction pump is mainly based on experience and model test.Taking the WQ32-11-2.2 submersible pump as the research object,this paper has an in-depth discussion on the structural mechanical properties and flow field distribution.The detailed contents and conclusions are as follows:(1)The analysis of single-phase flow field.It tries to verify the feasibility of the numerical modeling and work out the speed-pressure and turbulence distribution of double-channel with double-suction pump.It can predict the external characteristic curve of pump by numerical modeling of running double-channel with double-suction pump in rinsing.The results show that: the impeller passage flow has flow separation and vortex areas.There is a certain negative pressure zone in the impeller head.The flow separation and vortex region is significant near the hub and shroud cross section.(2)The analysis of sandy two-phase flow field.It tries to predict the total pressure difference curves of the pump imports and exports and compare that with the single-flow pump.It calculates the pump velocity-pressure distribution and solid phase particle trajectory under different sand diameters and different concentrations as well as different flow conditions.The results show that in two-flow condition,the outlet total pressure is bigger and the pressure gradient is greater as well as the flow separation loss and whirlpool area is more serious.(3)The intensity analysis of pump rotor system.The paper uses fluid-solid coupling method to calculate the stress and deformation of the pump rotor system.The results show that impeller appears to curve and deform because of field pressure at the outer edge of the impeller but the tensile deformation is not obvious due to centrifugal force.The basic trend of stress distribution is similar,the maximum appears in the axle while the minimum in the axletree.(4)The strength analysis of motor part.The paper uses static method to calculate the stress and deformation of the motor part.The results show that under different load of temperature,due to the thermal stress resulting from thermal expansion,the axle is the largest while rotor is the smallest and the upper end cover is the largest while the lower cover is the smallest as for thermal deformation.But the stress all in the permitted range of the material,the intensity damage won't happen.And it is rather safe because the strain is within the allowable range of project.On one hand,the research achievements of this paper have a certain guiding significance and practical engineering values to improve the flow state,perfect the flow design and improve the reliability of this kind of pump.On the other hand,the research method can provide some theoretical support and the further structure optimization for the safe operation of this kind of pump.