AbstractSquare-ribbed coolant channels with helium gas for fusion power reactors were designed to enhance the turbulent heat transfer in comparison with smooth coolant channels. Heat transfer coefficients and friction factors in the square-ribbed annular channels were investigated quantitatively under high pressure. The turbulent heat transfer coefficients in the square-ribbed annulus, with a ratio of the rib pitch to a height of ten, were 200–300% higher than those in the smooth annulus and then the thermal–hydraulic empirical correlations were derived. The average heat fluxes from the heated wall were predicted using the present empirical correlations and the maximum heat flux at p/h=10 reached ≈1.5 MW/m2 at Re=65 000. From the results of the present study, it can be expected that the proposed rib-roughened coolant channels are available to remove surface heat fluxes at the first wall and blanket in the fusion power reactors.
核融合動力炉用の角リブ付き冷却流路は、滑らかな冷却流路と比較して乱流熱伝達を向上させるために設計された。角リブ付き環状流路における熱伝達係数と摩擦係数を、高圧条件下で定量的に調査した。リブピッチとリブ高さの比が10である角リブ付き環状流路における乱流熱伝達係数は、滑らかな環状流路のそれよりも200〜300%高く、その後、熱流動の経験的相関式が導出された。加熱壁からの平均熱流束は、本経験的相関式を用いて予測され、p/h=10における最大熱流束は、Re=65 000で約1.5 MW/m²に達した。本研究の結果から、提案されたリブ粗面化冷却流路は、核融合動力炉における第一壁およびブランケットの表面熱流束を除去するために利用可能であることが期待できる。