Method for detecting source of oxide scale peeled off from inner wall of heated surface of boiler

Abstract

The invention relates to a method for detecting a source of a piece of oxide scale peeled off from the inner wall of a heated surface of a boiler. The method comprises the steps of selecting a piece of oxide scale with a light grey surface and a black or dark grey surface, observing the black or dark grey surface of the oxide scale by utilizing a scanning electronic microscope with an X-ray energy dispersive spectrometer, finding out residues on an inner layer of the oxide scale, and carrying out X-ray energy spectral analysis on the residues on the inner layer of the oxide scale so as to obtain an X-ray energy spectral analysis result; and comparing the X-ray energy spectral analysis result of the residues on the inner layer of the oxide scale with an alloy steel element in a tubular screen of the heated surface, and determining the source of the peeled oxide scale. By adopting the method, the oxide scale peeled off from the tubular screen can be easily and conveniently determined to be peeled from the inner wall of which material, so that the peel-off and pipe blockage problem of the oxide scale can be treated in a targeted manner in a power plant.

Description

technical field [0001] The invention belongs to the field of material detection and analysis, and in particular relates to a method for inspecting the source of scale peeled off on the inner wall of a heating surface of a boiler. Background technique [0002] The thermal power generation unit operates in a long-term high-temperature environment. The boiler superheater and reheater tubes are oxidized by high-temperature water vapor to form scales. Due to the large difference between the linear expansion coefficients of the scales and the matrix, it is easy Peeling is blocked at the lower elbow. At present, the peeling and blocking of pipes on the high-temperature heating surface of coal-fired generator sets has become the most important reason for unplanned shutdown of the unit. [0003] The medium temperature of the boiler superheater and reheater gradually increases from the inlet to the outlet. In order to reduce the cost, the manufacturer generally combines a variety of a...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a method for inspecting the origin of scale peeling off on the inner wall of the heating surface of the boiler. The detection method is simple and convenient, and overcomes the defects that the traditional method is time-consuming, laborious, and causes a great waste of steel pipes that can still be used.

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