Article ID Journal Published Year Pages File Type
7055927 International Journal of Heat and Mass Transfer 2016 18 Pages PDF
Abstract
This paper presents an investigation of transient pool boiling heat transfer phenomena in water at atmospheric pressure under exponentially escalating heat fluxes on plate-type heaters. Exponential power escalations with periods ranging from 5 to 100 ms, and subcooling of 0, 25 and 75 K were explored. What makes this study unique is the use of synchronized state-of-the-art diagnostics such as infrared (IR) thermometry and high-speed video HSV, which enabled accurate measurements and provided new and unique insight into the transient boiling heat transfer phenomena. The onset of nucleate boiling (ONB) conditions were identified. The experimental data suggest that ONB temperature and heat flux increase monotonically with decreasing period and increasing subcooling, in accordance with the predictions of a model based on transient conduction and a nucleation site activation criterion. Various boiling regimes were observed during the transition from ONB to fully developed nucleate boiling (FDNB). Onset of the boiling driven (OBD) heat transfer regime and overshoot (OV) conditions were identified, depending on the period of the power escalation and the subcooling. Forced convection effects have also been investigated and are discussed in the companion paper (Part II).
Related Topics
Physical Sciences and Engineering Chemical Engineering Fluid Flow and Transfer Processes
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