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structure observation of pyroelectric ceramics during power generation cycle川崎 卓郎; 福田 竜生; 山中 暁*; 坂本 友和*; 村山 一郎*; 加藤 孝典*; 馬場 将亮*; 橋本 英樹*; Harjo, S.; 相澤 一也; et al.
Journal of Applied Physics, 131(13), p.134103_1 - 134103_7, 2022/04
被引用回数：1 パーセンタイル：17.38(Physics, Applied)The microscopic origin of the pyroelectric power generation using ferroelectric ceramics for energy harvesting from time-varying waste heat can be understood by conducting 
neutron diffraction measurements. The behavior of the domain orientation and lattice strain in the lead zirconate titanate (PZT)-based ceramics with a tetragonal structure during the novel power generation cycle combining electric field and temperature change were investigated. The [001] domains and the lattice strain of the (111) plane in the direction of parallel to the electric field increase in the process of simultaneous rise in the electric field and temperature, and rapidly decrease in the process of the field drop. The alignment of the domain orientation by the electric field and its randomization by the higher temperature during the cycle are critical features of the current power generation system.
Kim, J.*; 山中 暁*; 村山 一郎*; 加藤 孝典*; 坂本 友和*; 川崎 卓郎; 福田 竜生; 関野 徹*; 中山 忠親*; 武田 雅敏*; et al.
Sustainable Energy & Fuels (Internet), 4(3), p.1143 - 1149, 2020/03
被引用回数：16 パーセンタイル：64.8(Chemistry, Physical)Waste heat is a potentially exploitable energy source but remains a problem awaiting a solution. To explore solutions for automobile applications, we investigate pyroelectric power generation from the temperature variation of exhaust gas using a novel electro-thermodynamic cycle. Niobium-doped lead zirconate titanate stannate (PNZST) ceramics were applied as pyroelectric materials, and their structural characteristics were investigated. In the driving cycle assessments (JC-08) using real exhaust gas, the maximum power generated was identified as 143.9 mW cm
(777.3 J L
per 1 cycle) over a temperature range of 150-220 
C and an electric field of 13 kV cm-1. The net mean generating power of the total driving cycle was 40.8 mW cm, which is the most enhanced result in our power generating systems to date and 314 times greater than our first report. Materials with sharp transition behaviors with the temperature and electric field are worthy of study with regard to pyroelectric energy harvesting materials, and their corresponding crystal and domain structures were investigated to optimize performance.
村川 英樹*; 橋本 迪矩*; 杉本 勝美*; 浅野 等*; 竹中 信幸*; 持木 幸一*; 安田 良
日本機械学会論文集,B, 77(784), p.2255 - 2262, 2011/12
A dynamic CT system was developed for visualization of consecutive three-dimensional water behavior in a PEFC stack for neutron radiography. The system is composed of a neutron image intensifier and a C-MOS high speed videocamera. An operating stack with three cells based on the Japan Automobile Research Institute standard was visualized using the neutron radiography system at a research reactor JRR-3 in Japan Atomic Energy Agency. The dynamic water behavior in channels in the operating PEFC stack was clearly visualized every 15 seconds by using the system. The water amount in each cell was evaluated by the CT reconstructed images. It was shown that a cell voltage decreased gradually when the water increased and increased rapidly when the water was evacuated. It was estimated that the power generation stopped when the channel of a cell was partly filled with the water because the air supply was blocked to a cell in the stack.
竹中 信幸*; 浅野 等*; 杉本 勝美*; 村川 英樹*; 橋本 迪矩*; 進藤 徳高*; 持木 幸一*; 安田 良
Nuclear Instruments and Methods in Physics Research A, 651(1), p.277 - 281, 2011/09
被引用回数：5 パーセンタイル：38.65(Instruments & Instrumentation)Visualization of dynamic three-dimensional water behavior in a polymer electrolyte fuel cell (PEFC) stack was carried out by neutron CT using a neutron image intensifier. The neutron radiography system at JRR-3 in Japan Atomic Energy Agency was used. An operating stack with three cells based on Japan Automobile Research Institute standard was visualized. A consecutive CT reconstruction method by rotating the fuel stack continuously was developed using a neutron image intensifier and a C-MOS high speed video camera. The dynamic water behavior in channels in the operating PEFC stack was clearly visualized in 15 s intervals by the present dynamic neutron CT system.
森山 清史; 丸山 結; 中村 秀夫; 橋本 和一郎; 加茂 英樹*; 大貫 晃; 秋本 肇
第7回動力・エネルギー技術シンポジウム講演論文集 (00-11), p.451 - 456, 2000/11
JASMINE-preは、軽水炉シビアアクシデント時の水蒸気爆発における粗混合過程を解析するための伝熱流動シミュレーションコードである。本コードは、新たに開発した溶融物モデルを二相流解析コードACE-3Dと結合したものである。溶融物モデルは、溶融物ジェット、プール、液滴という3成分から成り、ジェットとプールは各々垂直方向及び半径方向の1次元モデル、液滴は粒子群を1つのラグランジュ粒子で表すグループ粒子モデルで記述している。本コードを用いて、低融点金属の溶融物ジェットを水プール中に落下させた実験(非沸騰条件)、及び、アルミナ溶融物ジェットを水プール中に落下させた実験(沸騰を伴う条件)のシミュレーションを行い、本コードがこれらの条件で溶融物ジェットの水プール中での分裂、粗混合領域の形成、デブリベッドの堆積を扱えることを確認した。
