The Research on Effects of the Medium Blocking on Motion Performances of Main Steam and Feed Water Isolation Valves With its Driving Device

This article presents the study of the medium block effects on the driving device performances of main steam and feed water isolation valves, which are typical electromechanical equipment in nuclear power plants. The equipment simulation model is established, which can calculate motion performances under all working situations. The medium blocking force models during the motion of valves are established and the blocking effects on the driving device performances are calculated and analyzed. The simulation results show that the medium block has little effects on the opening performances of the driving device, while it has important effects on the closing performances, especially on the quick closing, which suggests that the equipment should be lubricated to reduce resistance coefficients and the main parameters of electromechanical equipment should be tuned and calibrated to guarantee the quick closing time.