High-Pressure Transition Boiling in Internal Flows

Transition boiling heat transfer was studied for the case of internal flow of high-pressure water. Transition boiling results were determined from measurements from 138 steady-state tests conducted in a temperature-controlled facility. Water flowed vertically upward inside a tube with inside diameter = 10.1 mm and vertical length = 13.1 m, as it was heated by liquid sodium flowing countercurrent in a surrounding annulus. The water parameter range of the experiments was pressure 7–15.3 MPa and mass flux 0.7–3.2 Mg/m²•s. A mathematical model was developed that predicted the transition boiling heat transfer coefficient well over the entire parameter range.