Helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. In this kind of heat exchangers, flowand heat transfer are complicated. This paper reports a numerical investigation of theinfluence of different parameters such as coil...

the present work is an experimental study of steady state convective heat transfer of de-ionized water with a (0.04% by volume) volume fraction of al2o3 nanoparticles dispersed to form a nanofluid that flows through an aluminium tube.laminar fully developed flow heat transfer coefficient of al2o3 nanoparticles are dispersed in water in circular tube is discussed in this paper. in order to valid...

the presence of particles in liquid-solid fluidized beds enhances the bed heat transfer, because the movement of the particles leads to an increased turbulence in the system. moreover, the violent movement of the particles has a positive effect on fouling of the heat transfer surface. the aim of this investigation was to perform systematic measurements of bed voidage and heat transfer coefficie...

This paper reported an experimental research of steady-state heat transfer behaviour of a gas flowing through a fixed bed under the different operating conditions. Studies had been carried out in a fixed-bed packed methanol synthesis catalyst percolated by air at appropriate flow rate. Both radial and axial direction temperature distribution had been investigated under the different operating c...

Using of nanofluids and ducts with corrugated walls are both supposed to enhance heat transfer, by increasing the heat transfer fluid conductivity and the heat transfer area respectively. Use of a diverging duct with a jet at inlet section may further increase heat transfer by creating recirculation zones inside the duct. In this work two-dimensional incompressible laminar flow of a nanofluid e...

the present experimental study reports on enhancement of heat transfer by addition of nanoparticles to the working fluid of commercial swimming pool heat exchangers under laminar flow condition. three different concentrations of titanium dioxide nanoparticles were added to the water as working fluid of a typical forced convective heat exchanger used to transfer heat to public swimming pools. th...

Fouling is a common, fundamental and costly problem in heat transfer systems, which reduces thermal efficiency of equipment, increases the energy loss and causes strong damage to the heat transfer equipment in various industries. The main causes of fouling on the heat transfer surfaces are salts with inverse temperature-solubility in the fluid which calcium sulfate is one of the most important ...

In the current study, reduction of nitrogen oxide from exhaust gas in the presence of NH3 as reductant on selective catalytic reductant (SCR) impregnated catalytic converter was simulated using Comsol© software. Mass transfer (one-dimensional) and heat transfer (three-dimensional) governing equations were taken into account to model the unsteady state behavior of the catalytic converter. Modeli...

in this study, bio-based carbon nanotubes (cnts) have received considerable research attention due to their comparative advantages of high level stability, simplistic use, low toxicity and overall environmental friendliness. new potentials for improvement in heat transfer applications are presented due to their high aspect ratio, high thermal conductivity and special surface area. phonons have ...

Numerical analysis of global heat transfer with coupled thermal radiation and heat conduction is investigated in Czochralski silicon crystal growth furnace with curved diffuse and specular surfaces. The ®nite element method and the radiation element method are adopted to solve the global heat transfer and the radiative heat exchange, respectively. The emphasis focuses on the discussion of the i...