Boiling crisis due to bubble interactions

The boiling crisis determines the maximum heat flux for the safe operation of boiling equipment, which is widely used in various applications including power generation, thermal management of electronics and water desalination. Here we present a mechanistic and predictive theory for the boiling crisis, combining the thermo-fluidic interaction between bubbles and the stochastic interaction of nucleation sites. Using Rayleigh and Poisson distributions, we demonstrate that the boiling crisis occurs when the population of isolated nucleation sites reaches the maximum. We identified a dimensionless boiling crisis constant 1/pi e, which universally relates the bubble base diameter to the isolated nucleate site density during the saturated pool boiling crisis. This finding is supported by our direct numerical simulation as well as by previous numerical and experimental results. Combining the thermo-fluidic and stochastic interaction, quantitative and simultaneous predictions of the critical heat flux (CHF) and the corresponding wall superheat at the CHF were achieved, which agrees with existing experimental data. Our theory thus offers a new avenue for understanding the boiling crisis, and therefore can serve as a guideline for the future boiling enhancement design. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study introduces a mechanistic and predictive theory for the boiling crisis, successfully predicting the critical heat flux (CHF) and the corresponding wall superheat by combining the thermo-fluidic and stochastic interaction. This theory offers a new avenue for understanding the boiling crisis and can serve as a guideline for future boiling enhancement design.