Scale detecting instrument in tube on high-temperature heating surface of supercritical boiler and detection method

Abstract

The invention discloses a scale detecting instrument in a tube on a high-temperature heating surface of a supercritical boiler and a detection method. The detecting instrument comprises a measuring probe, a reference probe, an amplifying circuit, a subtracter, an A / D converter, a singlechip and a display. In the detection method, magnetic signals from a position to be detected and a scale-free position of the detected tube are respectively converted into voltage signals by the measuring probe and the reference probe; after the two voltage signals are amplified by the amplifying circuit, differential voltage signals are acquired through the subtracter and converted into digital signals by the A / D converter; and the digital signals are sent to the display for displaying after being processed by the singlechip. According to the difference value of magnetic flux density detected by the measuring probe and the reference probe, the scale detecting instrument can detect the thickness of scales in the tube on the heating surface quantitatively, and thus the scale detecting instrument can perform quantitative detection quickly and conveniently on the accumulation thickness of the scales in the tube on the high-temperature heating surface of the boiler.

Description

technical field [0001] The invention belongs to the technical field of magnetic non-destructive testing, and provides a supercritical boiler high-temperature heating surface tube internal oxide skin detector and a detection method, which are used for non-destructive testing of supercritical boiler high-temperature heating surface tube internal oxide skin, especially for large super ( Detect the accumulation of oxide scales at the pipe bends in supercritical power plant boilers. Background technique [0002] In recent years, with the continuous improvement of technical parameters and capacity of thermal power plants, austenitic stainless steel pipes have become more and more widely used on the heating surface of super (super) critical boilers. At present, the grades of austenitic stainless steel materials used in China mainly include Super304H, TP316H, TP347H and Russian 12Cr18Ni12Ti etc. Although the oxidation resistance temperature of austenitic stainless steel can reach a...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, to provide a supercritical boiler high-temperature heating surface tube oxide skin detector and detection method, to realize the accurate judgment of the thickness of the oxide scale accumulation in the tube, which is convenient, fast and accurate , safety and other characteristics, it solves the problems in the prior art because of the bulky detection instrument, long measurement time, and harm to the measurement personnel.

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