Steady state pool boiling heat transfer coefficients have been obtained experimentally for acetone–isopropanol–water and acetone–MEK (methyl ethyl ketone)–water ternary systems. The data show that, for a given heat flux, the heat transfer coefficients of mixtures are lower than those obtained for pure components constituting the mixture. The measured heat transfer coefficients were compared wit...

Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by volume). Since CHF is the upper limit of nucleate boiling, such enhancement offers the potential for major performance improvement in many practical applications that use nucleat...

Nanofluids are engineered colloids composed of nano-size particles dispersed in common fluids such as water or refrigerants. Using an electrically controlled wire heater, pool boiling Critical Heat Flux (CHF) of Alumina and Silica water-based nanofluids of concentration less than or equal to 0.1 percent by volume were measured. Silica nanofluids showed CHF enhancement up to 68% and there seems ...

A semi-empirical model for pool boiling over porous surfaces is presented. The pressure drop across the porous surface is estimated using Darcy 's law. The signi®cance of the latent heat ̄ux contribution for highly porous surfaces is examined. Two nucleation factors are de®ned and correlated in terms of measurable quantities using literature data. An expression for the total heat ̄ux in terms o...

Conduction and single-phase convective heat transfer are well understood phenomena: analytical models [1] and empirical correlations [2] allow capturing the thermal behavior of plate-type fuels or heaters in contact with a single-phase coolant. On the other hand, transient boiling heat transfer is a scarcely studied and much less understood phenomenon. Although, earlier studies have shown that ...

An experimental investigation of the performance of thermosyphons charged with water as well as the dielectric heat transfer liquids FC-84, FC-77 and FC-3283 has been carried out. The copper thermosyphon was 200 mm long with an inner diameter of 6 mm, which can be considered quite small compared with the vast majority of thermosyphons reported in the open literature. The evaporator length was 4...

Abstract. The article discusses the use of laser treatment to produce surfaces that enhance boiling heat transfer. beam has been applied on copper substrates generate longitudal fins regular geometry. altered morphology pattern enables dissipate higher flux values than smooth, untreated surface – in case distilled water and ethyl alcohol as agents. issue modeling nucleate pool processed is disc...

A new technique is developed to directly grow Cu nanowire (CuNW) on Si substrate with electrochemical deposition to produce height-controlled hydrophilic nanowired surfaces for enhancing pool boiling performance. For broader heat transfer applications, CuNW and Si nanowires (SiNW) with various nanowire heights were fabricated and examined under pool boiling with water. The heat transfer perform...

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The formation of deposits on heat transfer surfaces is the main hurdle in optimum operation of thermal desalination units. It is, therefore, common practice to operate these units i.e. MSF under sub-atmospheric pressure to boil saline water below saturation temperature of which depositions occurs. However this comes with high price-tag for excessive use of energy for pumping. Alternative and en...