Avoiding Steam Bubble Collapse-Induced Water Hammer in the Auxiliary Piping of Steam Power Plants

The mechanisms of steam bubble collapse-induced water hammer are identified for nominally horizontal or inclined pipes. On the basis of these observations, two methods of preventing steam bubble collapse-induced water hammer in nominally horizontal pipes are proposed. They are inclining them and injecting the water at a controlled rate at either the lowest point or injecting the water at several locations. The success of these methods is demonstrated for horizontal pipes and for pipes of other orientations. These ways of preventing steam bubble collapse-induced water hammer are then used to test filling strategies for “L”-shaped pipes oriented in practically every way. Both methods are found to work though the application of multiple injection ports and has complications when applied to a complex piping system. The use of the recommended design guidelines for avoiding steam bubble collapse-induced water hammer is demonstrated in an example problem.