Analysis on step action of hydraulic control rod driving

The step action of the hydraulic control rod driving (HCRD) has been achieved by experiments. The author reveals the action mechanism of the HCRD, gives detail analysis of the relationship among its dynamic feature, the control rod and combined valve performance parameters, and the combined valve operation. The results indicate that the step process of the control rod is affected by output flow pulsation of the combined valve, pressure wave, and heavily damped pressure oscillation that is produced by the step cylinder movement. The performance parameters of the step cylinder limit the flow range in its stationary balanced state and also limit the capability of absorbing flow pulsation and pressure wave in its step process. The performance parameters of the combined valve decide the quantity values of stationary balance, delay balance, flowing pulsation and pressure wave. The relation of both parameters determines the step states of the control rod