An overview of the methods for transient control and of the effectiveness of the protection equipment and device specifications: cases and accidents

摘要

The analysis of transients in hydraulic systems is now well established and various codes, mostly based on the method of characteristics (MOC), provide engineers with the necessary tools to understand the transient phenomena. Unfortunately, boundary conditions normally related to the dynamic behavior of the protective devices such as cavitation and choked phenomena in control valves, transient flow and closing conditions of air and check valves, inertia effects of surge chambers such as air vessels, one way surge tanks and other, do not always correspond to the device specifications. Some installations have failed, as described in this paper, due to the misunderstanding of the real protective devices operation. During the last decade some new dynamic devices were designed to control transients in hydraulic installations and to protect their components. The purpose of this paper is to present and discuss such innovative ideas in order to identify their operational effectiveness.