Some years ago Vignati (refs. 1, 2, 3) showed that, under some particular circumstances (inter alia : isobaric processes connected through internal heat exchangers), the efficiency of an Ericsson cycle involving a real gas can exceed the Carnot limit ηC , in contradiction with the second principle of thermodynamics. However, the convergence of Vignati’s algorithm, giving the temperature differe...

The present study investigated the effect of distilled-water/ silver nanofluid on heat transfer in a closed cooling system of one of the electrical energy generation units at Isfahan power plant. The difference between this study and previous researches refers to silver properties which have a high thermal conductivity and is non-toxic, hydrophilic and eco-friendly. Distilled water/ silver ...

heat exchangers are one of the most important devices of mechanical systems in modernsociety. most industrial processes involve the transfer of heat and more often they requirethe heat transfer process to be controlled. a heat exchanger is the heat exchanged betweentwo media, one being cold and the other being hot. there are different types of heatexchanger, but the type which is widely used in...

The excellent performance of fluidized bed heat exchangers is due to the interaction between particles and heat transfer surface and to the mixing effects in the viscous sublayer. In this paper, the results of experimental investigations on heat transfer for a wide range of Newtonian and non-Newtonian (shear-thinning power law) fluids are presented. New design equations have been developed ...

The heat transfer model of vertical ground heat exchangers for ground-source heat pump systems is discussed. An explicit solution of a finite line-source model has been derived to better describe temperature response of boreholes for long time steps, which can be easily incorporated into computer programs for thermal analysis of ground heat exchangers. A quasi-three-dimensional model is also pr...

the excellent performance of fluidized bed heat exchangers is due to the interaction between particles and heat transfer surface and to the mixing effects in the viscous sublayer. in this paper, the results of experimental investigations on heat transfer for a wide range of newtonian and non-newtonian (shear-thinning power law) fluids are presented. new design equations have been developed for ...

A-Type heat exchangers are used to meet required heat load with minimum duct dimensions in air-conditioning applications. This greatly reduces the air-conditioning system footprint in residential and commercial applications. The angle and tube spacing of the A-type heat exchangers should be optimized for minimum duct size and maximum heat load. However, existing air side heat transfer and press...

fouling is one of the main parameters in design of any exchanger. ignoring this parameter causes problems such as overheating or under- heating of process streams. in this article a heat exchanger network was designed using process streams data in cdu of tehran refinery. then using tema fouling factors, network exchangers were designed and area and cost were estimated. by changing fouling facto...

In this study, effect of adding in SiO2 nanoparticle in base fluid (water) in car radiator is investigated experimentally. Radiators are compact heat exchangers that optimized and evaluated by considering different working conditions. Car\'s cooling system, plays an important role in vehicle\'s performance, consists of two main parts, known as radiator and fan. Radiators are compact heat exchan...