高速炉直管型蒸気発生器解析評価システムの開発; 伝熱管プラグ条件下での構造健全性評価への適用検討

Development of simulation system for straight tube steam generator of sodium-cooled fast reactor; Application Study for structural integrity evaluation under heat transfer tube plugging condition

吉川 龍志  ; 今井 康友*; 田中 正暁  ; 大島 宏之

Yoshikawa, Ryuji; Imai, Yasutomo*; Tanaka, Masaaki; Ohshima, Hiroyuki

高速炉直管型蒸気発生器の伝熱流動設計や構造安全性評価への適用を目的として、ナトリウム側3次元解析と水側マルチチャンネル解析を組み合わせた連成解析システムTSGを整備している。本研究では、試験解析を通して蒸気発生器内熱流動評価への適用性を確認した。また、大型直管型蒸気発生器体系への適用に向け、複数本伝熱管をプラグした条件を対象とした解析を実施し、局所温度上昇を含む非対称温度分布を評価できることを確認し、伝熱管温度偏差により構造健全性を評価できる見通しを得た。

Accurate evaluation of three-dimensional temperature distribution is essentially required for the structural integrity analysis of large-sized straight tube steam generator (SG) of an advanced sodium-cooled fast reactor (SFR). Numerical simulation system TSG to analyze three-dimensional thermal-hydraulics in the straight tube SG has been developed. The three-dimensional simulation on sodium side by the CFD code FLUENT with porous body model was coupled with the multi-channel simulation on water/steam side. Fundamental validation of TSG code with the 1MWt straight tube SG test was performed. Temperature distribution of large-sized SG under the condition with plugged tubes was analyzed and the temperature deviation of heat transfer tubes was evaluated. Through the numerical simulation, local temperature increase near the plugged tubes was quantitatively evaluated, and the applicability of the simulation results to the structural integrity analysis of straight tube SG was indicated.