This paper focuses on the relationship between bubble behavior and bumping of aging oil. A visualization boiling vessel is built and relevant mathematical model is established according to the generation

growth

departure and rising of single bubbles

recorded by a high-speed camera. Results show that

with the increase of driving force ΔTs (degree of superheating)

the water on the heat transfer surface boils

forming vapor-in-oil bubbles. The departure time of bubbles decreases with the increase of heat flux

while the density of nucleation sites on the heat transfer surface increases. As ΔTs increases continuously

a bubble layer forms when the rupturing rate of bubble is lower than their producing rate. Accumulation of a large number of bubbles will make the bubble layer amplify to the entire container space rapidly to form bumping.