並列タイトル等Study on the main design parameters of large scale FBR,3; Study on optimization of tube size for intermediate heat exchanger
一般注記1次熱輸送系の主要機器である中間熱交換器(IHX)構造の小型化を図るため、IHX伝熱管の小径化、及び薄肉化の可能性を追求し、伝熱管寸法緒元の最適化に係わる検討を行った。本検討においてIHX伝熱管の薄肉化限界を設計、製作、検査等の観点から明らかにし、また伝熱管口径、板厚、ピッチ比等のパラメータ・サーベイを実施して最適構造案を導き出した。更に構造上、応力的に厳しいと予想される部位について評価した。ここでIHX内流路構成としては、1次管側、及び胴側の2ケースを対象とした。以上の検討により次の結論を得た。(1)伝熱管の板厚限界は、管-管板の現状技術における溶接の信頼性から求まり、その板厚は、0.8mmである。(2)伝熱管板厚、口径、ピッチ比(P/D)を小さくすることは、必要伝熱面積を小さくする上で最も有効である。(3)IHX1次管内の場合、1次胴側と比較して管束部体積で同一材料の条件のもとで、約40\%の小型化が達成できる見通しを得た。(4)構造健全性の観点からは、1次管内の場合、1次胴側に比べて管板部の発生応力が低減される傾向にあることが明らかとなった。総合的に判断して、伝熱管直径19mm、板厚0.8mmおよび適切なピッチ比を目標仕様とした場合、従来のIHXに比べ管束部体積で1次管内の場合40\%以上、また1次胴側の場合10\%以上の小型化の達成が可能となる。
A study on the optimization of the tube size for Intermediate Heat Exchanger (IHX), which is one of the main components of LMFBR primary heat transport system, through an investigation of the reduction in the diameter and thickness of the tube was carried out to make the structure of an IHX compact. In this study, a limitation of the tube thickness was clarified from the viewpoint of design, manufacturing, inspection, etc., and the optimum, structure of an IHX was derived from the parametric survey of the diameter, thickness and pitch ratio, etc., of the tube. Also, stress was evaluated for all portions where stress is considered to be hard structurally. The primary coolant flow paths of IHXs supposed in this study are both in the tubes and in the shell around tubes. The results gained from the study are as follows: (1)The reliability on the welding technique of the joint of tubes and tube sheet leads to the thickness limitation of 0.8mm. (2)It is most effective to reduce the thickness, diameter and pitch ratio of the tube for reduction of the active heat transfer surface. (3)The volume of the tube bundle for an IHX with the primary coolant flow path in the tubes is expected to reduce by 40\% compared with that for an IHX with the primary coolant flow path in the shell around tubes. (4)It was clarified froi the viewpoint of the structure integrity that the stress occurring in the tube sheet for an IHX with the primary coolant flow path in the tubes has a tendency to be reduced compared with that for an IHX with the primary coolant flow path in the shell around tube. It was concluded from the above mentioned results that the volume of the tube bundle for an IHX with the desired specification of tubes of 19mm diameter, 0.8mm thickness and proper pitch ratio is estimated to be reduced more than 40\% for an IHX with the primary coolant flow path in the tubes, and more than 10\% for the primary coolant flow path in the shroud around tube compared with the usual one.
一次資料へのリンクURL/PNC-TN9410-89-059.pdf (fulltext)
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース(IRDB)(機関リポジトリ)
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