Numerical Simulation Of Erosion In Inlet Channel Of Helico-axial Multiphase Pump

Due to the advantages of large displacement and insensitivity towards sand particles,helico-axial multiphase pump is widely used in the field of oil and gas industries.However,the erosion phenomena caused by the impacts of sand particles in the inlet channel of this kind of pump are very common,which result in potential damages for the normal operation of pump and safety production.Based on computational fluid dynamics(CFD),this problem is investigated by the numerical simulation method in this work.The results obtained from the present work have important values in engineering applications.An erosion prediction model based on Eulerian-Lagrangian approach under one-way coupling is established,including the three modules of flow model,particle transport model and erosion equation.The accuracy of those three modules is verified and validated by the exact solutions and existing experimental results.Based on the CFD simulation,the above validated model is applied for the inlet channel of the multiphase pump in order to study its erosion rule.The maximum erosion rate of liquid-solid increases exponentially with the inflow velocity and this index is 2.76.It is also linearly correlated with mass flow rate of the particles.With the increase of particle size,it is first reduced and then increased and the critical particle size is about 100?m.Then,the influence degree of three main parameters on erosion is studied by adopting the orthogonal design method.The results show that solid particle erosion in this case is the most affected by the mass flow rate,the speed is the second and particle size is the least.In addition,it is found that there is no vortex in the flow field of the gradual expansion inlet channel and the pressure drop is smaller than the other two types of inlet channels.More importantly,its maximum erosion rate is 1/2 of the sudden expansion channel.These observations show that the gradual expansion channel with expansion angle of 5? has the advantages in reducing the energy loss and erosion as well as ensuring the pump working in high performance.Therefore,it is recommended to adopt this gradual expansion channel as the inlet channel of the helico-axial multiphase pump.