報告書番号

U01065

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2) --数値モデルによる壁面擦過効果の推定手法の開発--

タイトル（英文）

Study on a Mesure of Reducing Biofouling with Solid Body Abrasion (Part2) - Development of an Estimation Method of Effectiveness of Solid Body Abrasion using Numerical Model -

概要 （図表や脚注は「報告書全文」に掲載しております）

前報では，火力・原子力発電所の冷却水路系の付着生物防除技術に関連して，管路内の旋回流流速分布を推定する手法を提案した．しかし，固形物擦過法を実際の冷却水路系に適用するには，旋回流中の粒子挙動を明らかにする必要がある．本研究では，旋回流中の粒子挙動に関する数値モデルを開発するとともに水理実験を行い，解析結果と実験結果の比較・検討を行った．その結果，旋回流中の粒子挙動は粒径や粒子密度，流速，旋回強さに影響を受けることが分かった．また，流速変動を考慮した数値モデルはそれらを適切に表せることが分かった．さらに，冷却水路系における固形物擦過法の適用性を調べるため，数値モデルによる付着生物防除効果の評価手法を開発した．そして，その評価手法を用いて管内径3.0mの冷却水路系を対象に固形物擦過法の適用性を調べた．

概要 （英文）

In a companion report (Part1) regarding a measure of reducing biofouling in a cooling water channel of a power plant, the estimation method for velocity profiles of swirling flows generated in a pipe was proposed. However, it is necessary to clarify the 3-D behavior of particles injected in swirling flows, in order to apply this solid body abrasion method to actual cooling water channels. In this report, a numerical model was proposed on the basis of the theoretical equations of motion and rotation for a particle considering the empirical equations for swirling flows proposed in the report (Part1). In order to verify the proposed numerical model, hydraulic experiments were conducted and the 3-D behavior of particles in swirling flows were measured using imaging processing techniques, and it was clarified that the particle diameter and density, the swirl intensity and the average flow velocity strongly affect the particle's motion. Also the validity of the numerical model which considers velocity fluctuations was confirmed through the comparison with the experimental results. Furthermore, the estimation method of effectiveness of the solid body abrasion in actual cooling water channels was developed using the proposed numerical model, and an applicability of the solid body abrasion to a channel of 3.0 m in diameter was examined using this estimation method.

報告者

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