Problems of sodium using in pulsating heat pipe made from fused silica

You Heat pipe is a high efficiency heat transfer element, depends on the evaporation, condensation and circulation of inside working fluid. The working fluid of a high temperature pulsating heat pipe is generally alkali metals, and sodium heat pipe can operate in range of 500-1100°C. In order to investigate terminal velocity of working fluid, the glass pulsating heat pipe was produced for experimental purposes. The experiment was carried out, in order to simulate real operating conditions in range of 500-1100°C. Sudden boiling of liquid sodium (b.p. = 883°C at 1 atm) inside the all quartz-made heat pipe results in high-temperature reaction of sodium vapour with the inner wall surface. The reaction became more aggressive with increasing vapour temperature and resulted in heat pipe explosion. The evaluation of damage character is analysed in this paper