中性子ラジオグラフィを用いた新型ヒートパイプ内部流動の可視化

抄録

Today’s society, self-heating of electric devices or machineries becomes serious problem, so the novel cooling device called Low Filling Rate-Pulsating Heat Pipe (LFR-PHP) has been invented. LFR-PHP is consisted of meandering flow path made from aluminum alloy and water as the working fluid. When the one side of LFR-PHP is heated, the working fluid start flowing through the flow path, and the heat is transported from the heating area with the flowing of working fluid. According to past investigation, the heat transfer coefficient of LFR-PHP is greater than conventional cooling devices. However, its mechanism of working fluid flowing and heat transportation is not clear. So, we conducted the neutron radiography experiment to LFR-PHP. The neutron radiography is a visualization technique using the neutron beam. In this paper, we introduce the result of neutron radiography experiment and consider the mechanism of LFR-PHP. According to the experiment, we observed the flowing of liquid slugs from heating zone to cooling zone, and the moving speed got faster when the heating power raised. Also, we observed some liquid slugs in the cooling zone or insulating zone had become shorter and eventually been faded with time passing. However, we had not observed the flux of working fluid from cooling zone to heating zone while the experiment.