since the energy analysis considers the quantity of energy, it cannot show the performance of the cooling tower. therefore, in order to optimize the performance of the tower and also the process which the cooling tower is a part of it, it is necessary to analyze the energy and exergy of the tower simultaneously. in this paper, the energy and exergy of one of the cooling towers of khuzestan stee...

This paper presents a numerical study of local mass transfer coefficients in a 90° bend using the RNG version of k–e model to include the influence of curvature on the turbulent transport. Simulations were performed for flow through a 90°, 3-D bend for Reynolds numbers of 13500, 90000, and 390000, Schmidt numbers of 2.53 and 700 and curvature ratios of 1.5, 2, and 2.5. The differences betwe...

In this paper, we have considered the problem of rotating, magnetohydrodynamic heat and mass transfer by free convective flow past an exponentially accelerated isothermal vertical plate in the presence of variable mass diffusion. While the temperature of the plate is constant, the concentration at the plate is considered to be a linear function with respect to time t. The plate is assumed to be...

In the present study, the effect of various nanofluids on mass transfer coefficients in an irregular packed liquid-liquid extraction column was investigated. The chemical system of toluene–acetic acid–water was used. 10 nm SiO2, TiO2 and ZrO2 nanoparticles with various concentrations were dispersed in toluene-acid acetic to provide nanofluids. The influence of concentration and hydrophobicity/h...

In order to improve the efficiency and rate of heat transfer in heat exchangers, various techniques such as increasing the heat transfer coefficient are proposed. This study is devoted to the investigation of heat transfer coefficient variations due to the addition of CuO, TiO2 and CuO/TiO2 nanoparticles into a shell and tube heat exchanger. CuO/TiO2 nanocomposite was synthesized using mechanic...

In this research, the thermodynamics and mass transfer of CO2 absorption has been studied in a mixture of MDEA-MEA amines. A relation is presented for mass transfer flux in the reactive-absorption process. For this purpose, the effective parameters on the mass transfer flux were investigated in both liquid and gas phases. Then, using dimensional analysis with the Pi-Buckingham theorem, the effe...

Membrane contactor using amine based absorbents is an efficient technology for CO2 separation from gaseous mixtures. A novel porous polysulfone (PSF) flat membrane was prepared via non-solvent phase inversion method. The PSF membrane was modified by adding polyvinyl pyrrolidone (PVP) to the dope solution. The fabricated membrane was used in the serpentine flow field contactor module for CO2 abs...

an investigation on the thermal performance of the soil as geothermal heat energy storage medium has been conducted. the thermal characteristics of the soil storage and the heat transfer from a heat exchanger in the soil, surrounding and bottom surface will be discussed. this investigation forms a contribution to a project to realize such storage to be charged from a solar heating system. this ...

liquid membrane processes have attracted many interests in recent years for removal of heavy metals such as cadmium from industrial wastewaters. in this study, a modified hybrid liquid membrane system is introduced. the setup is worked by applying the water-insoluble dioctyl phthalate as the organic solvent. n-octanol and tetra butyl ammonium bromide are added to the organic phase to increase t...