An investigation of transient boiling heat transfer with conjugate nature

Abstract

Temperature controlled transient boiling experiments have been performed to study the effects of mass flux on boiling of F-113 in a vertical annular channel. At higher velocities transient effects have been suppressed. It is also found that quenching may start from both ends of the heated tube and that quenching starting at the downstream end may result in a lower critical heat flux. Transient convective boiling heat transfer could be of conjugate nature with respect to the solid wall. However, the behavior of a transient conjugate heat transfer problem can be primarily characterized by the parameter: d T i/d t (the interface temperature rate). This is confirmed by the analysis of a conduction problem, a single phase convection problem, and the data of the present experiments. The transient critical heat flux increases as d T i/d t increases for heat-up processes but decreases as |d T i/d t| increases for cool-down processes.