短脉冲激光加热下液氮爆发沸腾实验观测

21世纪的超导研究将步入实用化阶段。在超导体工作中,其所处的低温环境(液氮、液氦)有可能受到瞬时高热流的冲击,从而导致爆发沸腾的发生,甚至影响到超导体的安全、稳定工作。对此,有必要进行系统的实验和理论研究,揭示低温工质的爆发沸腾现象与过程特征。本文就是基于这一目的,首次从实验角度观察液氮的爆发沸腾行为,拍摄到液氮爆发沸腾时的系列照片,并测量了脉冲加热期间以及之后的温度变化。发现了一些新颖并值得关注的现象。

THE OBSERVATION OF EXPLOSIVE BOILING IN LIQUID NITROGEN SUBJECTED SHORT-PULSED LASER HEATING

The superconducting technology will step into practice in 21st century. During the working period of superconductor, the necessary low-temperature environment (liquid nitrogen, liquid helium) may undergo the transient high heatflux. This sudden heat impulse thus would induc?the explosive boiling, even result in the unsafe working condition. So the systematical study on this kind of boiling behavior is very useful and important, and the related experimental research should be done to reveal the explosive boiling phenomenon and characters throughout entire process happened within low-temperature liquid. For this reason, this paper performed the first observation of explosive boiling in liquid nitrogen (LN2), took the series photographs which showed the interesting boiling behavior, and recorded the temperature variation of heating surface during and after the laser puls? This paper illustrated the novel and meaningful phenomenon.