液体窒素予冷コイルによる液体水素ランタンクの予冷時間の推算法

抄録

A development of the H-II launch vehicle, which will put the 2-ton-class payload into geosynchronous orbit, is progressed by NASDA in Japan. A 910-kN-thrust LOX/LH₂ rocket engine, LE-7 was to be developed as a first stage propulsion system of the H-II launch vehicle. In a first development phase of this engine, a short duration firing test facility feeding high pressurized propellant was needed to carry out the firing test of the combustion system components of this engine. This firing test facility has the thick wall runtanks for feeding high pressurized propellant to those components. In this paper, the cool-down time of the thick wall runtanks with a chill-down coil by using liquid nitrogen is analyzed in consideration of the heat transfer characteristics and the changes of fluid phase. Then, a calculation method estimating the cool-down time is presented. Experiments confirmed the estimating method in a relatively good agreement.