Estimate of scale thickness for iron pipes in geothermal power generation using acoustic emission sensor [Metoda określania grubości rury stosowanej w geotermalnych źródłach energii bazująca pomiarze emisji akustycznej]

Journal article

Authors/Editors

Strategic Research Themes

Publication Details

Author list: Yuji T., Kinoshita H., Bouno T., Thungsuk N., Tati S., Tanaram T., Mungkung N.

Publisher: Wydawnictwo SIGMA - N O T Sp. z o.o.

Publication year: 2020

Volume number: 96

Issue number: 9

Start page: 133

End page: 137

Number of pages: 5

ISSN: 0033-2097

URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85093508932&doi=10.15199%2f48.2020.09.28&partnerID=40&md5=246160924924e3f7b616c6c8189161a1

Languages: English-Great Britain (EN-GB)

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Abstract

Currently, geothermal power generation is attracting attention in Japan as the next renewable energy source. However, tapping of this energy requires substantial equipment and entails enormous maintenance costs for this equipment. In particular, in the steel pipes connected to steam wells in geothermal power generation stations, when water vapor is collected from steam wells, the hot spring component known as yunohana (mineral encrustations left by hot springs) precipitates and forms into scale and adheres to the steel pipes. This causes clogging and deterioration of pipes by metal corrosion due to the sulfur content, which requires periodic maintenance and other measures to be taken for most equipment. Consequently, a remaining life assessment technique for maximizing the life of steel pipes connected to geothermal power generation steam wells is required as a continual improvement measure for enabling stable usage of equipment over a long period of time. As a non-destructive test, we used ultrasonic sensors to measure the ultrasonic waves generated from changes in the water flow due to changes in the thickness of the scale adhering to the inside of the pipes and the ultrasonic waves propagated from the change locations of the metal surface, and this enabled us to confirm the buildup of scale using an acoustic emission (AE) sensor for successfully assessing the remaining life. © 2020 Wydawnictwo SIGMA-NOT. All rights reserved.

Keywords

Acoustic emission sensor, Fast fourier transform method, Geothermal generation, Maharanobis distance, Scale