Numerical study on saturated pool boiling heat transfer in presence of a uniform electric field using lattice Boltzmann method

Abstract

For the industrial equipment with boiling, critical heat flux (CHF) is an important parameter that determines its upper limit of heat load for safe operation. Therefore, increasing CHF is of great importance in engineering field. Previous studies proved that it’s an effective way to enhance boiling heat transfer and CHF by electrohydrodynamics (EHD). However, it is difficult to investigate the influence mechanism of the electric field on the bubble dynamics and boiling heat transfer because of the limit of experimental technical methods. Thus, in this paper, a two-dimensional lattice Boltzmann model was established by coupling the pseudopotential model with phase-change model and electric field model to meet the lack of studies on simulating the pool boiling in presence of an electric field. After validating the rationality of the two-dimensional lattice Boltzmann model established at present study, the heat transfer during nucleate boiling and film boiling under a uniform electric field were studied in detail. In addition, the influence of electric field intensity on boiling curves and CHF was investigated quantitatively. In the partial nucleate boiling regime, a uniform electric field had limited influence on bubble dynamics and boiling heat transfer. In the fully developed nucleate boiling regime, increasing electric field intensity could enhance boiling heat transfer obviously. In the film boiling regime, increasing electric field intensity could slightly enhance averaged heat flux at first. After the electric field intensity reached a certain value, averaged heat flux increased rapidly. Increasing electric field intensity could expand the nucleate boiling regime, and enhance CHF and the wall temperature at CHF point.