報告書番号

U01047

タイトル（和文）

固形物擦過法による付着生物防除対策に関する研究 (その1) --旋回流流速分布の推定手法の開発--

タイトル（英文）

Study on a Mesure of Reducing Biofouling with Solid Body Abrasion (Part1) - Development of an Estimation Method for Velocity Profiles of Swirling Flows in a Pipe -

概要 （図表や脚注は「報告書全文」に掲載しております）

火力・原子力発電所の冷却水路系にはムラサキイガイ等の生物が付着し，取水量の減少などの原因になる．付着生物を防除する方法には様々な方法があり，そのひとつとして当所から固形物擦過法が提案されている．固形物擦過法とは，人為的にスポンジボールなどの固形物を旋回させながら水路内を通過させ，配管への接触擦過によりスライムや付着直後の幼体を除去して付着生物の成長を防ぐ方法である．これは，模擬海水配管(管内径0.10m)と2分割弁型旋回流発生装置，スポンジボールを用いた基礎実験において付着量が約1/10になることが確かめられている．しかし，旋回流の水理特性は調べられていない．本研究では，2種類の旋回流発生装置を対象に水理実験を行い，旋回流の流速分布や旋回強さ，エネルギー損失を調べた．さらに，旋回流発生装置直上流でのエネルギー損失増加量から任意断面の旋回流流速分布を推定する手法を開発した．

概要 （英文）

A flow rate of a cooling water channel in a power plant tends to be reduced by biofouling, for example, mussel fouling, which adheres to the inner wall of the water channel. There are many measures of reducing biofouling. A solid body abrasion is one of their measures and has been proposed previously by one of the authors. The concepts of the solid body abrasion method are briefly described as follows: Swirling flow is generated in the channel; Particles are feeded into it and roll and slide on the wall; Juvenile organisms are abraded by the particles. Although an experiment using a model conduit of 0.10 m in diameter was conducted, the problem still remains that the hydraulic mechanism of the solid body abrasion and the characteristics of the swirling flows should be solved. In this report, the hydraulic experiments with two swirl generators, one of which is a guide-vane type and the other is a two-divided valve type, were conducted to examine the velocity profiles of swirling flows characteristics. The energy loss were measured using the manometer. The velocity fields were measured using the LDV and the swirl intensities were calculated from these results. The relation between the swirl intensity and the energy loss was examined. Furthermore, an estimation method for velocity profiles of swirling flows in a pipe was developed.

報告者

キーワード