A detection method of boiler heating surface tube thinning

Abstract

The invention discloses a detection method for the thinning amount of the heating surface tube of a boiler, comprising: step 1: obtaining the standard wall thickness d of the heating surface tube of the Lamb wave in the boiler to be detected 1 The dispersion curve below; Step 2: Obtain the optimal detection frequency f according to the group velocity dispersion curve in the dispersion curve 1 ;Step 3: Obtain the best detection frequency f in step 2 1 corresponds to the phase velocity c of the Lamb wave in the phase velocity dispersion curve p , and determine the sound beam incident angle α according to Snell’s law; Step 4: According to the sound beam incident angle α in step 3, the variable-angle probe is connected to the ultrasonic flaw detector and maintained at the optimum detection frequency f 1 and collect the echo signals of S0 mode and A0 mode; Step 5: Obtain the transit time difference of the S0 mode and A0 mode end face echo according to the echo signal, and conduct the heating surface tube according to the transit time difference thinning calculation. The present invention can complete the detection conveniently and quickly through the method, and improves the reliability of the detection result as above.

Description

technical field [0001] The invention belongs to the field of non-destructive testing of containers, in particular to a method for detecting the thinning amount of tubes on the heating surface of boilers. Background technique [0002] The safe operation of the heating surface of boilers in thermal power plants is the most important work of metal technical supervision in thermal power plants. For high-parameter and large-capacity units, especially ultra-critical (ultra)critical units, the units are affected by soot blowers and flue gas during operation, and the heating surface tubes are prone to blowing damage and thinning. At present, the inspection of the boiler heating surface is mainly based on macroscopic inspection. This method has low inspection efficiency and requires a high sense of responsibility for the inspectors, and there will be missed inspections in places that cannot be seen. Therefore, this inspection method is very important for the stable operation of the b...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the defects of low inspection efficiency in the existing detection method of boiler heating surface tube thinning, and the detection results of ultrasonic thickness gauge detection have random and accidental problems, it is necessary to provide a boiler heating surface tube The detection method can complete the detection conveniently and quickly. Based on the Lamb wave detection, it overcomes the randomness and contingency of the detection results brought about by the midpoint measurement method of the existing ultrasonic thickness gauge, and improves the reliability of the detection results.

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