An experimental study of the rewetting of a hot surface at atmospheric conditions using sub cooled liquid at various flowrates

In this study several experiments have been carried out to investigate the effect of coolant flow-rate upon the rewetting mechanism of a vertical annular channel encircling a heated rod at atmospheric conditions. A specifically designed and constructed experimental facility has been used to simulate the two-phase water flow phenomena of the rewetting process at atmospheric conditions and different degrees of inlet sub-cooling. The facility is a two-loop water flow system with a real time computer interface for operational monitoring as well as control and data acquisition during experiments. The wet front propagation along a stainless steel cylindrical surface vertically positioned at top flow rewetting conditions has been examined in the flow-rate range of 0.5 to 1.0 L min^-1, inlet water sub-cooled in the range of 0 to 50 °C with an initial surface temperature of the rod up to 550 °C at atmospheric conditions. The result presented in this study shows that the rewetting velocity increases with an increase in liquid flow-rate and sub-cooling and decreases with an increase of the initial surface temperature.