Leakage flow characteristics in throttle clearance of self-balancing multistage centrifugal pump
To study the leakage characteristics and flow mechanism of throttling seal in the outlet sec-tion of self-balancing multistage pump with high head and large flow rate,a three-dimensional numeri-cal analysis models of three types of throttling seals were established under five radial throttle clearance(0.5,0.8,1.0,1.2 and 1.5 mm).The leakage flow,turbulent kinetic energy dissipation,and seal flow force of the sealed fluid in the throttle seals were calculated and analyzed.The research results in-dicate that the leakage flow characteristics of the throttle seal are influenced by the radial contraction ratio and axial turbulent kinetic energy dissipation rate.The radial throttle clearance directly affects the fluid pressure and radial contraction ratio at the inlet of the radial throttle clearance.The labyrinth teeth have significant influence on the turbulent kinetic energy dissipation rate,while the turbulent kinetic energy dissipation rate of the fluid in expansion cavity is close to zero.The fluid pressure in the radial throttle clearance generally presents a step wisel decreasing law along the axial direction.Sealing teeth can effectively reduce the pressure of the sealing fluid.Compared with the first type of seal,the contact between the sealing teeth on the rotor face and the sealing fluid,as well as the increase of the radial throttle clearance are the main reasons for the axial force on the rotor face of the second and third type seals.
万方数据
维普
