Author(s)

A. Rogalev, A. Kocherova, I. Komarov, I. Garanin, G. Kurdiukova

Abstract

The paper explores the nature and the cause of dynamic forces exerted by the flow on the walls of energy equipment. The most loaded parts are the ones in which there is a sharp change of the working medium flow direction (steam supply system of a turbine, valves, pipeline bends). In these parts, centrifugal forces cause a transverse pressure gradient, which leads to separations of the flow. The separations cause broad frequency spectrum pressure oscillations, the amplitude of those may reach more than 10% of the initial pressure. As a result, energy equipment has to work under a heavy dynamic load.

There are some effective ways to reduce dynamic loads, and the most popular of them is the installation of a special device – a flow stabilizer – in the parts of equipment that suffer from them. The existing stabilizers are mostly the disk with different kinds of perforation, which are installed transversely to the flow direction. They dispel the separation vortexes and level uneven velocity profiles. It is obvious that they have such a high hydraulic resistance that it can nullify their economic effect. The resistance is mostly reduced by enlargement of the stabilizer’s diameter that causes some designing and exploitation difficulties.

In this paper some new designs of flow stabilizers are proposed. The most part of the new device’s surface is located streamwise, so they have the diameter of the pipeline. The comparative estimation revealed that the newly developed devices provide a comparable level of dynamic load reduction, but also have a much lower hydraulic resistance (3 and more times less) and are supposed to have a higher mechanical strength.

Keywords

power plant equipment, steam distribution system of steam turbines, non-uniform velocity profile, dynamic loads, flow stabilizer