Flow measurement of high temperature liquid metal using ultrasonic doppler profiling

超音波流速分布測定法による高温液体金属流動計測

大林 寛生  

Obayashi, Hironari

高温液体金属流動場中の流速計測は極めて難しく、実機配管等での速度分布計測を可能とする手法は超音波流速分布測定法(UVP)に限られる。本研究では、溶融鉛ビスマス流動場へUVPを適用した実験計測結果と、高温対応化に向けた音響ガイドシステムの開発,多次元計測化を目的とした新たな計測システムの開発について紹介する。

Measurement of Lead Bismuth Eutectic (LBE) flow velocity profile was successfully realized in the spallation target model loop of Accelerator Driven System (ADS) by the Ultrasonic Velocity Profiler (UVP) technique. UVP is a powerful tool to measure an instantaneous space-time velocity profile especially on a velocity measurement of an opaque liquid flow, such as liquid metal. We performed velocity measurement along the centerline of the loop and confirmed basic performance of the loop. It was found that there were periodical releases of eddy from the re-circulation region formed near the wall surface of the inner cylinder. We made then a measurement for non-parallel directions with the centerline and observed 3-dimensional structure of LBE flow configuration. On the other hand, there is not the ultrasonic transducer which can apply to high temperature at more than 300 degrees Celsius. Therefore, the development of the high-temperature transducer that can be used at the high temperature condition is a pressing need because it establishes the velocity measurement techniques for LBE flow. Thus we adopted the acoustic wave guide method and conducted a survey of the suitable guide material for LBE flow by using the wave equation.