Numerical Calculation for Flow Field of Servo-Tube Guided Hydraulic Control Rod Driving System

A new-style hydraulic control rod driving mechanism was put forward by using servo-tube control elements for the design of control rod driving mechanism.The results of numerical simulation by CFD program Fluent for flow field of hydraulic driving cylinder indicate that the bigger the outer diameter of servo-tube,the smaller the resistance coefficient of variable throttle orifice.The zero position gap of variable throttle orifice could be determined on 0.2 mm in the design.The pressure difference between the upper and nether surfaces of piston was mainly created by the throttle function of fixed throttle orifice.It can be effectively controlled by changing the gap of variable throttle orifice.And the lift force of driving cylinder is able to meet the requirement on the design load.