Calculation methods of diagnostics for tube constructions elements of power equipment destruction

The report is devoted to analysis of increasing vibro-reliability of power equipment elements namely heat exchanger and steam generators. According to statistics, power equipment destruction is a result of heat exchanger tubes intense vibrations in tube bundles, as the most loaded elements. Therefore, the problem of mathematical models creation which allow assessment and analysis of hydrodynamic forced vibrations in tube bundles becomes actual. For this, forces acting on the tube bundles in flow and hydrodynamic connections between them are determined. By means of obtained hydrodynamic connections matrices the behavior of tube bundle depending on the velocity of approach flow is studied, the boundary of system transition to an unstable state is determined, i.e. the corresponding values of cross flow critical velocity for different types of tube bundles. Based on obtained hydrodynamic connections matrices amplitude-frequency characteristics for a particular tube bundle were determined. (C) 2019 The Authors. Published by Elsevier B.V.