Film boiling heat transfer around a very high temperature thin wire immersed into water at pressure from 1 to 210 bar: Experimental results and analysis

When a hot liquid comes in contact with a more volatile one, we may observe a vapor explosion. This is due to the intense vapor production caused by the high heat transfer between micronic fragments (resulting from the fine fragmentation of the hot liquid) and the coolant. An experimental apparatus called TREPAM investigates this heat transfer. In this experiment, the coolant level rises at a constant velocity over a fixed high temperature tungsten wire. Measurement of wire electric resistivity, which is related to the wire temperature, enables the calculation of the heat transfer. This heat transfer is studied in the ranges of:-wire diameter from 10 to 250 μm-wire temperature from 1350 to 2900 K-water subcooling from 0 to 350 K-water velocity from 0.2 to 46 m/s-pressure from 1 to 210 bar.Scaling analysis considers two extreme cases. In the first one, most of the heat lost by the wire is used to heat the water while, in the second one, it is used for vaporization. As the majority of the tests correspond to the first case, a correlation is established for these cases of high subcooling. Differences with other similar type correlations are discussed and explained by different film boiling configurations.