Impact of heater thermal properties on nucleate pool boiling: Insights from a multiscale automata simulation

Abstract

This study investigates the influence of heater material properties on nucleate pool boiling using a comprehensive simulation model. Copper and silicon oxide are selected as reference materials due to their properties as excellent and poor heat conductors, respectively. The model integrates well-known heat transfer mechanisms, allowing for the assessment of the effects of these distinct heater materials. The results show that materials with superior thermal diffusivity,such as copper, significantly enhance cooling efficiency during nucleate boiling. Moreover, the study provides insights into the relationship between bubble growth, microlayer recovery beneath a bubble, temperature fluctuations, and heater properties. Comparisons between copper and silicon oxide underscore variations in bubble frequency, attributed to differences in bubble growth time, microlayer recovery time, and material-dependent behavior. The influence of neighboring boiling sites is especially pronounced in silicon oxide due to itslow thermal conductivity and diffusivity values. Temperature variations in this material become highly visible due to its very slow response to temperature changes. Simulation results align well with semi-empirical correlations, confirming the model’s success in capturing the intricate phenomena of nucleate pool boiling. In summary, the model reveals that changes in the thermal properties of the heater affect not only boiling performance but also key characteristics of the process, including bubble frequency, boiling patterns, regularity, and cavity reactivation speed.