Experimental study and numerical analysis on electromagnetic force of direct action solenoid valve

Abstract

Control rod hydraulic drive mechanism (CRHDM) is a newly invented patent and Institute of Nuclear and New Energy Technology Tsinghua University owns CRHDM's independent intellectual property rights. The Integrated valve which is made up of three direct action solenoid valves is the key part of this technology, so the performance of the solenoid valve directly affects the function of the integrated valve and the CRHDM. Based on the operation conditions of the Control Rod Hydraulic Drive System, the electromagnetic force of the direct action solenoid valve was analyzed by experiment and numerical method. The result shows that the electromagnetic force of the solenoid valve increases with the increasing current or the decreasing the length of the air gap. In addition, the electromagnetic force is saturated when the current goes up to the threshold, so the working input current should be the threshold. What is more, the electromagnetic force of the solenoid valve with the flat contact surface is larger than the one whose contact surface is cone. Finally, the operation time of the valve with the flat contact surface is shorter than the one with the cone contact surface on the condition that the length of the air gap is longer, but the result is opposite when the length of the air gap is shorter. In order to gain big electromagnetic force and short operation time, the structure of the solenoid valve is that the contact surface is flat with the seal ring.