EXPERIMENTAL STUDY ON CRITICAL HEAT FLUX OF FORCED CONVECTION BOILING IN UNIFORMLY HEATED VERTICAL TUBE

An experimental study on critical heat flux of forced convection boiling in uniformly heated vertical tube was carried out, using Freon 12 as the working fluid with critical heat flux q c measured in a 16mm diameter circular tube. The effect of steam quality and mass velocity on CHF has been investigated. The results obtained were found to be essentially consistent with the CHF data measured by other authors. However, the influence of pressure on CHF was complex and coupled with mass velocity and steam quality. In the lower steam quality region, CHF decreased with increasing pressure,while in the higher steam quality region, CHF increased with increasing pressure.