• Gan, T. H.
• Selcuk, C.
• Kogia, M.
• Balachandran, W.
• Cheng, L.
• Mohimi, A.
• Kappatos, Vassilis

Abstract

<p>Solar thermal industry is a promising renewable energy source and an environmentally friendly mean of power generation, which converts sunlight into electric power. Parabolic Trough Concentrated Solar Plants (CSPs) is the most widely used type of CSP and its main components are the parabolic trough shaped reflectors and the absorber tubes. The absorber tubes have a complex structure and operate at high temperatures (400°C-500°C); as a result, they are likely to suffer from creep, thermo-mechanical fatigue, hot corrosion etc. Hence, both their inspection and monitoring is of crucial importance and very challenging tasks as well. Electromagnetic Acoustic Transducers (EMATs) are a promising, non-contact technology that can be used for the inspection of large structures at high temperatures by exciting Guided Waves. In this paper, a study regarding the basic principles of EMATs, their potential use in this application and their performance at high temperature is presented. In addition, a Periodic Permanent Magnet (PPM) EMAT with racetrack coil, exciting Shear Horizontal waves, has been experimentally evaluated both at room and high temperatures. During the experiments these EMATs were tested on a stainless steel plate so that an experimental characterization of their ultrasonic potentials would be accomplished. Additionally, the EMATs were tested regarding the impact of shielding on their performance, their power supply requirements, their lift-off limitations and their performance at high temperatures as well.</p>

Topics

• impedance spectroscopy
• stainless steel
• corrosion
• experiment
• fatigue
• ultrasonic
• creep