Experimental investigation of quench phenomena and two-phase flow behavior for hot horizontal tubes well above the limiting temperature for solid-liquid contact

Quench cooling of a hot dry surface involves the rapid decrease in surface temperature by a sudden contact with a coolant. Situations involving quenching are encountered in a number of postulated accidents in Canada Deuterium Uranium (CANDU) reactors, such as quenching of a hot calandria tube in certain Loss of Coolant Accidents (LOCA). In this study, an experimental setup has been built and a series of experiments were conducted to investigate quenching of hot horizontal tubes by a water multi-jet system. The effects of key role parameters on the re-wetting delay time, the re-wetting front velocity and the quench and re-wetting temperatures were investigated. These variables were found to be strongly dependent on water subcooling. The effects of initial surface temperature, jet velocity and surface curvature were also investigated. (author)