Enhancement of R123 pool boiling by addition of hydrocarbons

Abstract

ABSTRACT

Effect of surfactant additives on nucleate pool boiling heat transfer of refrigerant-based nanofluid

“…The decrease of surface tension causes the decrease of the superheat degree of the bubble nucleation, the decrease of bubble departure diameter, and the increase of bubble departure frequency. (2) The surfactants accumulate at the heating surface and form the excess layer, reducing the surface-energy between the liquid and the heating surface [13], thus the active nucleation sites increase. (3) The surfactants may aggregate in the fluid and form the large particles [28].…”

“…For the effect of surfactant on the nucleate pool boiling heat transfer of pure water, organic fluids or water-organic fluid mixtures, most of the researches indicated that the presence of surfactant enhances the nucleate pool boiling heat transfer [6][7][8][9][10][11][13][14][15], but some researches indicated that the surfactant deteriorates the nucleate pool boiling heat transfer or has little effect on the nucleate pool boiling heat transfer [5,12]. For the effect of surfactant on the nucleate pool boiling heat transfer of water-based nanofluid, the research reported by Chopkar et al [16] showed that the presence of surfactant deteriorates the nucleate pool boiling heat transfer, but the research reported by Kathiravan et al [17] showed that the presence of surfactant enhances the nucleate pool boiling heat transfer.…”

“…Until now, the researches related to the effect of surfactant on the nucleate pool boiling heat transfer are focused on pure water [5][6][7][8][9][10][11], organic fluids [12,13], water-organic fluid mixtures [14,15] or water-based nanofluid [16,17], and there is no published research on refrigerant-based nanofluid. For the effect of surfactant on the nucleate pool boiling heat transfer of pure water, organic fluids or water-organic fluid mixtures, most of the researches indicated that the presence of surfactant enhances the nucleate pool boiling heat transfer [6][7][8][9][10][11][13][14][15], but some researches indicated that the surfactant deteriorates the nucleate pool boiling heat transfer or has little effect on the nucleate pool boiling heat transfer [5,12].…”

The effect of a boiling additive on R123 condensation on a vertical integral-fin surface

“…In other words, rather than using the boundary conditions to solve for the interior temperatures, the interior temperatures were used to solve for the boundary conditions following a backward stepwise procedure given in Kedzierski (1995 Kedzierski (1998) Figure 9 shows that the heat transfer coefficient increases with decreasing AT S due to decreasing condensate film thickness with decreasing AT S , As expected, most of the heat transfer coefficients for the R 123/isopentane mixture are less than that of pure R123. The heat transfer coefficients for R 123/isopentane (99.5/0.5) for AT S < 1 are significantly less than that of pure R123.…”

“…However, the economic benefit of additives that enhance boiling heat transfer can be realized only when the additive does not significantly degrade the condensation heat transfer. Kedzierski (1999) In another boiling additive study, Kedzierski (1998) Kedzierski and Worthington (1993), the size and arrangement of the thermocouple wells were designed to minimize the errors in the wall temperature and temperature gradient measurement.…”