Thermal Power Research Section, and Information and Communication Engineering Research Section
As major equipment in a coal-fired power station, the boiler contains numerous tubes that are prone to abrasion from ash erosion and steam cuts. Stable continuation of power generation needs periodic measurement of the outer diameter and wall thickness of a boiler tube. In fact, conventional inspection of boiler tubes has required considerable expenses and time due to its narrow and deep position.
To solve this technological problem, the Research & Development Department has started the development of an ultrasonic wall thickness measurement apparatus for coal-fired boiler tubes including the deep part in collaboration with Nikko Inspection Service Co., Ltd (located in Muroran city, Hokkaido).
Advantageously, our compact and portable ultrasonic wall thickness measurement apparatus can scan the outer diameter and wall thickness of the tube in a continuous and three-dimensional manner (able to detect surface flaws), by moving an ultrasonic probe on the boiler tube outer surface, both circumferentially and axially. Also, a performance test was conducted in the deep part of the boiler tube in our coal-fired power station to confirm the ability of this apparatus to provide desired results.
Photo-1 Ultrasonic wall thickness measurement apparatus
Fig-1 Sample of measurement results
HEPCO will introduce this apparatus in our coal-fired power station in regular inspection periods accordingly, aimed at comprehending more accurate soundness of the boiler and also reducing maintenance costs.