Study On The Erosion Of Hedge-Type Energy Dissipation Device In High-Pressure Desander

In order to reduce the energy of the high-pressure sand-carrying liquid flow discharged from the bottom flow port of the desander,the bottom flow port is chosen to be equipped with a hedgetype dissipator to achieve the purpose of effective pressure reduction.As the flow of high-pressure fluid in the hedge-type dissipator is more complex,the high-speed flow of sand particles on the wall of the dissipator pipe causes a huge i MPact,thus producing the phenomenon of erosion and wear deformation of the wall of the bend,which will lead to cracking of the pipe wall,perforation leakage and other hazards when serious,so that the dissipator fails.In view of this problem,it is important to investigate the erosion behaviour of the sand-carrying liquid flow with a hedge-type energy dissipator as the research object for safe production.In this paper,based on the solid-liquid two-phase flow theory and the theory of erosion and wear,a simulation model of the erosion of sand-carrying liquid flow in a hedge-type dissipator is established.The effect of time on the erosion is considered with the help of dynamic grid technology and transient simulation to investigate the changes in the erosion flow field of the dissipator and the deformation of the pipeline within 1100 s.The results show that with the changes of the influencing factors,the erosion pattern of the wall surface of the hedge-type energy dissipator also changes differently;with the increase of the flow velocity,particle size and particle mass flow rate,the erosion wear of the wall surface of the energy dissipator tends to increase;with the expansion of the size of the spherical inlet hedge zone,the overall change of the maximum erosion rate of the hedge-type energy dissipator tends to decrease first and then increase,and the optimum radius of the spherical inlet hedge zone is 45 mm.The optimum radius of the spherical inlet hedge zone is 45mm;with the increase of the tube diameter,the optimum tube diameter of the energy dissipator is 60mm;at 600 s,the internal erosion flow field of the energy dissipator gradually stabilises;due to the turbulence,the erosion deformation of the energy dissipator at the inlet main stream tube and the spherical inlet hedge zone is more obvious.Considering the hedge zone as the core working part of the dissipator,it directly affects the internal flow field and the erosion situation.The square hedge zone structure is used instead of the spherical hedge zone,and the distribution of the flow field in the tube of the square hedge type dissipator under solid-liquid two-phase flow erosion is analysed by numerical simulation.As the size of the square inlet hedge zone becomes larger,the erosion zone moves along the edge towards the centre and the erosion rate gradually decreases and the maximum erosion rate of the square hedge type dissipator is minimised at a prism length of 85 mm.The conclusions obtained are an important theoretical guide for the future design of the structure of the dissipator and the optimisation of the dissipator against erosion.