Electrical breakdown mechanism of liquid nitrogen in the presence of thermally induced bubbles

✍ Scribed by M. Hara; T. Kaneko; K. Honda

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 907 KB
• Volume: 27
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(87)90148-2

✦ Synopsis

An investigation of the electrical breakdown behaviour of liquid nitrogen in the presence of a local hot spot on an electrode has been performed to determine the breakdown mechanism of liquid coolant in cryoresistive or superconducting apparatus under quenching conditions. It has been found that the vapour bubbles are generated at a hot spot and the manner of the vapour generation and the vapour structure depend strongly on the ambient pressure, the heat transfer rate at a hot spot and the applied voltage. Electrical breakdown took place through various series of composites of liquid and gas phases, depending on the pressure and the heating power applied to a hot spot. Therefore, the breakdown characteristic of liquid nitrogen under hot spot conditions depended to a marked degree on these factors.