Control of the condition of heat exchange surfaces by free vibration method

Abstract

In power system the main heat carrier is the fresh water received from natural sources, and containing a large amount of various impurity – from the dissolved mineral salts to organic compounds. In housing and communal services and the industry cases of operation of heat-exchange devices and package boilers without special preparation of water aren’t rare. During the operation of the heat-exchange equipment of impurity are allocated in a firm phase both in the form of deposits and in the form of slime. Sediments cause deterioration in a heat transfer that leads to decrease in overall performance of the equipment (to an excessive consumption of fuel, metal overheating, etc.). The radiation surfaces of modern steam generators heating are intensively warmed with a furnace torch. Density of a thermal stream in them reaches 600-700 kW/sq.m, and local thermal streams can be even higher. Therefore even short-term deterioration in coefficient of a thermolysis from a wall to the boiling water leads to significant increase in temperature of a wall of a pipe (500-600 °C and above), durability of metal can it is insufficient to sustain tension which has arisen in him. The metal damages which are characterized by emergence of blisters, fistulas are a consequence of it, and it is frequent also a rupture of pipes. The scum reduces the useful section of pipes, increasing the hydraulic resistance of pipes of the heat exchanger. Everything together it involves an excessive consumption of fuel, and according to expert data the layer of scale up to 0.2 mm thick increases fuel consumption by 3%, and a layer in 1 mm for 7%.