Experimental investigation of CHF in temperature-controlled transient boiling systems

Experimental analysis on critical heat flux (CHF) in a temperature-controlled natural convective boiling system was examined in this work. The purpose of this study was to investigate the power transient and gap distance effects on CHF in narrow, vertical, rectangular parallel-plate flow. The time rate of the wall temperature (dT{sub w}/dt) was introduced to investigate the power transient effects during the heating and cooling modes. The results show that the transient effect during the heating process is more significant than that during the cooling process, and the CHF values increased as the gap distance increased during the heating process. The results also show that the new parameter, wall temperature rate, should be a good characteristic in transient boiling systems.