Critical heat fluxes on vertical tube inner surface in water flowing upward (Part 1. effect of tube inner diameter)

摘要

Flow boiling critical heat fluxes (CHFs) in subcooled boiling of water in a short vertical tubes with the inner diameters of 6 and 12 mm, the thickness of 0.3 and 0.2 mm and the length of 49 mm were measured for the flow velocities ranging from 4 to 13 m/s, for the inlet subcoolings ranging from 10 to 145 K and at the pressures of 594 and 800 kPa. Test tubes made of SUS304 were heated using a steadily increasing direct current source (35 V and 3000 A). The effect of tube inner diameter ranging from 6 to 12 mm is discussed.