Visualization of the Structure of Vapor-Liquid Flow During Subcooled R113 Refrigerant Boiling Under Preburnout Conditions

Boiling of dielectric liquids subcooled to the saturation temperature is a promising method for cooling modern electronic devices. This method makes it possible to remove sufficient heat flux densities (q), maintain the temperature of chip interfaces at the required level, and not create undesirable conditions leading to electrical breakdown in the event of a leak in the coolant circuit. The safe use of the boiling process of subcooled liquid is limited by heat flow densities, at which large agglomerates of the vapor phase appear in the core of the coolant flow, which carries the risk of hydraulic expansion of the applied cooling systems from parallel channels. In this work, using visualization through high-speed video recording (with a frequency of 5–10 kHz), an experimental study of the evolution of the structure of a two-phase flow during boiling of subcooled dielectric liquid R113 under preburnout conditions was carried out. It has been shown that, also characteristic of water, at q close to critical, the formation of large vapor agglomerates in the R113 flow. It has been established that an increase in the degree of subcooling and mass velocity leads to an increase in q at the moment vapor agglomerates appear. The influence of the heating rate of the heat-transfer plate on the structure of the two-phase flow in preburnout conditions and on the value of q at the moment of burnout is shown.