Showing papers on "Concentric tube heat exchanger published in 2013"
TL;DR: In this paper, the melting process in a triplex-tube heat exchanger with phase-change material (PCM) RT82.26 was numerically investigated using the Fluent 6.3.
363 citations
TL;DR: In this article, an experimental study on the forced convective heat transfer and flow characteristics of a nanofluid consisting of water and different volume concentrations of Al 2 O 3 (0.3-2)% flowing in a horizontal shell and tube heat exchanger counter flow under turbulent flow conditions is investigated.
219 citations
TL;DR: In this article, the effect of fluid flow and geometrical parameters on heat transfer rate in shell and coiled tube heat exchangers has been investigated experimentally using Wilson plots.
180 citations
TL;DR: In this article, the effect of different nanoparticle shapes (such as cylindrical, bricks, blades, platelets, and spherical) on the performance of a shell and tube heat exchanger operating with nanofluid analytically was studied.
134 citations
TL;DR: In this paper, the authors deduced the formula of entransy dissipation-based thermal resistance (EDTR) for different types of heat exchangers, analyzed the factors influencing heat exchanger performance and, more importantly, developed an alternative EDTR method for the design and optimization of heat exchange.
111 citations
TL;DR: In this paper, an experimental investigation was carried for measuring tube-side heat transfer coefficient, friction factor, heat transfer enhancement efficiency of water for turbulent flow in a circular tube fitted with rectangular-cut twisted tape insert.
105 citations
TL;DR: In this paper, the authors compared the performance of a double U-tube and a helical-shaped ground heat exchanger with an equivalent electrical circuit of thermal resistances and capacitances.
98 citations
TL;DR: In this paper, an experimental study was carried out in order to find out the effects of Al2O3 nanofluid with a mean diameter of 20nm on heat transfer, pressure drop and thermal performance of a double tubes heat exchanger.
92 citations
TL;DR: In this article, the authors presented the thermodynamic second law analysis of a helical coil heat exchanger using three different types of nanofluids (e.g. CuO/water, Al2O3/water and ZnO/Water).
87 citations
TL;DR: In this paper, the effect of nano-particles in heat transfer augmentation for smooth tube and helically corrugation tubes (HCT) was discussed and their relative Nusselt number was compared.
85 citations
TL;DR: In this paper, the thermal properties of three types of nanoparticles (Al2O3, TiO2, and SiO2) dispersed in water as a base fluid were measured experimentally.
Abstract: The additives of solid nanoparticles to liquids are significant enhancement of heat transfer and hydrodynamic flow. In this study, the thermal properties of three types of nanoparticles (Al2O3, TiO2, and SiO2) dispersed in water as a base fluid were measured experimentally. Forced convection heat transfer turbulent flow inside heated flat tube was numerically simulated. The heat flux around flat tube is 5000 W/m2 and Reynolds number is in the range of 5×103 to 50×103. CFD model by finite volume method used commercial software to find hydrodynamic and heat transfer coefficient. Simulation study concluded that the thermal properties measured and Reynolds number as input and friction factor and Nusselt number as output parameters. Data measured showed that thermal conductivity and viscosity increase with increasing the volume concentration of nanofluids with maximum deviation 19% and 6%, respectively. Simulation results concluded that the friction factor and Nusselt number increase with increasing the volume concentration. On the other hand, the flat tube enhances heat transfer and decreases pressure drop by 6% and -4%, respectively, as compared with circular tube. Comparison of numerical analysis with experimental data available showed good agreement with deviation not more than 2%.
TL;DR: In this paper, the air side thermal hydraulic performance of the wavy fin and flat tube aluminum heat exchanger was studied and the experimental correlation equations were developed for the heat transfer and pressure drop performances of a wavy-fin heat exchange by the multiple regression method.
TL;DR: In this article, the authors analyzed the influence of twisted pitch length P and aspect ratio A/B on the performance of the shell side of twisted oval tube heat exchanger and found that the intensity of spiral flow becomes more and more drastic with the increasing of A and decreasing of P.
TL;DR: In this paper, the heat transfer and pressure drop performance of a twisted oval tube heat exchanger has been experimentally studied and compared with a rod baffle and a smooth round tube.
TL;DR: In this article, the effects of using various types of nanofluids and rotation on heat transfer and fluid flow characteristics in a helically coiled tube heat exchanger (HCTHE) are numerically investigated.
TL;DR: In this article, an experimental and numerical study on the heat transfer of α-Al2O3/water nanofluid flowing through the double pipe and shell and tube heat exchangers, under laminar flow conditions, is presented.
Abstract: This research presents an experimental and numerical study on the heat transfer of α-Al2O3/water nanofluid flowing through the double pipe and shell and tube heat exchangers, under laminar flow conditions. Effects of important parameters such as hot and cold volume flow rates, nanofluid temperature, and nanoparticles concentration on the heat transfer characteristics are investigated. The results indicated that the heat transfer performance of both double pipe and shell and tube heat exchangers increases with increasing the hot and cold volume flow rates, as well as the particle concentrations and nanofluid inlet temperature. Compared with pure water, the results indicated that the heat transfer coefficients of nanofluid in the double pipe and shell and tube heat exchangers are higher than those of water by 13.2% and 21.3%, respectively. Also, the heat transfer performance of nanofluid in a shell and tube heat exchanger is 26.2% higher than the double pipe heat exchanger. A computational fluid dynamics (C...
TL;DR: In this paper, the authors describe the results of tube bundle replacement of a segmental shell and tube heat exchanger with a helical heat exchange, which was conducted in Tabriz Petroleum Company.
TL;DR: In this paper, an experimental study on concentric tube heat exchanger for water to nanofluids heat transfer with various concentrations of nanoparticles in to base fluids and application of nano-fluids as working fluid was conducted.
TL;DR: In this paper, the heat transfer characteristics of Al 2 O 3 -water nanofluids as a coolant used in concentric tube heat exchanger are presented, which is fabricated from copper concentric inner tube with a length of 1000mm.
TL;DR: In this paper, the performance of a triple concentric pipe heat exchanger is studied experimentally under steady state conditions for two different flow arrangements, called N-H -C and C-H-N, and for insulated as well as non-insulated conditions of the heat exchange.
TL;DR: In this article, the lattice Boltzmann method was used to investigate the heat transfer enhancement in a ventilated porous media plate heat exchanger, which is modeled by a square cavity with inlet and outlet thermally insulated ports and three hot fins with constant temperature.
Abstract: In this paper, the lattice Boltzmann method was used to investigate the heat transfer enhancement in a ventilated porous media plate heat exchanger. The heat exchanger is modeled by a square cavity with inlet and outlet thermally insulated ports and three hot fins with constant temperature. The Brinkman–Forchheimer model was used to simulate the porous domain. The effect of porosity and second fin position on heat transfer enhancement was studied at different Reynolds and Prandtl numbers. By decreasing the porosity, the heat transfer rate increases and the mean outlet temperature of the fluid increases for different Reynolds and Prandtl numbers. The result indicated that the porous medium has higher effect in Nusselt number at high Reynolds and Prandtl number. Also the fin position has a sensible effect on Nusselt number.
TL;DR: In this article, the experimental analysis of a titanium brazed plate-fin heat exchanger with offset strip fins in liquid-liquid heat transfer processes is presented, where the Wilson plot method is applied to the reduction of the experimental heat transfer data.
TL;DR: In this article, the authors investigate the shell-side thermo-hydraulic performance of a shell-and-tube heat exchanger with trefoil-hole baffles (THB-STHXs) under turbulent flow regime.
TL;DR: In this paper, a non-linear regression method was used to determine heat transfer coefficients in cross-flow heat exchangers with extended heat exchange surfaces, and the uncertainty in estimated parameters was determined using the error propagation rule by Gauss.
Abstract: This paper presents an experimental–numerical method for determining heat transfer coefficients in cross-flow heat exchangers with extended heat exchange surfaces. Coefficients in the correlations defining heat transfer on the liquid- and air-side were determined based on experimental data using a non-linear regression method. Correlation coefficients were determined from the condition that the weighted sum of squared liquid and air temperature differences at the heat exchanger outlet, obtained by measurements and those calculated, achieved minimum. Minimum of the sum of the squares was found using the Levenberg–Marquardt method. The uncertainty in estimated parameters was determined using the error propagation rule by Gauss. The outlet temperature of the liquid and air leaving the heat exchanger was calculated using an analytical model of the heat exchanger.
TL;DR: In this article, the effect of pressure on the average and local heat transfer coefficients between a submerged horizontal tube (25.4mm-O) and a fluidized bed has been determined.
TL;DR: In this paper, the heat transfer performance of inhomogeneous parallel plate heat exchangers in transient operation is investigated using an established model, and a performance parameter denoted the Nusselt scaling factor is used as benchmark and calculated using a well-established single blow technique.
TL;DR: In this article, the authors investigated the performance of a circular tube fitted with conical cut-out turbulator integrated with internal fins for three pitch ratios (PR) 3, 4, 5 and tested with two different arrangements as convergent mode and divergent mode (D-turbulators).
TL;DR: In this article, a multipole model based on the multipole theory is developed inside the borehole with a cylindrical heat source outside, considering the working fluid temperature variety along the U-tube and its heat convection.
TL;DR: In this article, numerical simulations for helical baffles heat exchanger with different Prandtl number (Pr) fluids and the comparison for heat exchangers with different helical tilt angle (β) were presented.