Numerical study of pressure drop and heat transfer from circular and cam-shaped tube bank in cross-flow of nanofluid

2016 ◽  
Vol 129 ◽  
pp. 319-328 ◽  
Author(s):  
Arash Mirabdolah Lavasani ◽  
Hamidreza Bayat
2013 ◽  
Vol 315 ◽  
pp. 650-654
Author(s):  
Abobaker Mohammed Alakashi ◽  
Hamidon Bin Salleh

The purpose of this research is to investigate effect of wake splitter to pressure drop and heat transfer characteristics in a tube bank with staggered arrangements. The pressure drop and averaged heat transfer coefficient of seven rows with five tubes in each row with integral wake splitter has been determined by means of 2-D simulation using commercial computational fluid dynamics (CFD) code Fluent. Two type of integral wake splitter length have been studied, 0.5D and 1D with different location. Simulations have been carried out at Reynolds number based on tube diameter from 5000 up to 27800. The results, presented in terms of pressure drop as well as averaged heat transfer coefficient values, show the influence of wake splitter length and direction. By adding 0.5D wake splitter at downstream direction leads to higher averaged heat transfer coefficient and reduction of the pressure drop.


Author(s):  
Ahmed M. Nagib Elmekawy ◽  
Abdalrahman M. Shahin ◽  
Alaa A. Ibrahim ◽  
Sara Al-Ali

Abstract Two-dimensional simulations are carried out for a heat exchanger to study the cross-flow behavior in a circular tube bank in a staggered configuration in case of bare cylinders and cylinders with splitter plate attachment. A considerable performance evaluation of the heat exchanger with splitter plate can be achieved by studying the heat transfer and the pressure drop of the flow. Numerical simulation results carried out from this study are compared to experimental results. The numerical investigation has been established to study the effect of splitter plate on the heat exchanger thermal performance as there were no previous studies performed on the optimization of the splitter thickness. The study also illustrates the effect of splitter plate thickness variation on pressure drop and heat transfer for different Reynolds number.


2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Amin Jodaei ◽  
Kamiar Zamzamian

Tube bank heat exchangers are designed to efficiently transfer heat between two fluids. Shapes and arrangements of tubes in heat exchangers have significant effects in heat transfer and pressure drop of fluid. In this study, the three-dimensional (3D) numerical investigation is performed to determine heat transfer coefficients, friction factor, and performance evaluation criteria (PEC) of cam-shaped tube banks in aerodynamic and inverse aerodynamic directions in the cross flow air and compared with those of elliptical tube banks in heat exchanger. The arrangements of tubes are aligned and staggered with longitudinal pitch of 44.88 mm and transverse pitch of 28.05 mm. Reynolds number in the range of 11,500–18,500 was used, and the tube surface temperature was fixed and considered 352 K. Results indicate the superior heat transfer of elliptical tube bank over the cam-shaped tube banks in inverse aerodynamic and aerodynamic directions in both arrangements. Moreover, the PEC of the cam-shaped tube banks with inverse aerodynamic and aerodynamic directions and elliptical tube bank in aligned arrangement are approximately 1.4, 1.1, and 1.6, respectively. The obtained results for staggered arrangements are also 1.5, 1.3, and 1.8, respectively.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4417
Author(s):  
Tingting Xu ◽  
Hongxia Zhao ◽  
Miao Wang ◽  
Jianhui Qi

Printed circuit heat exchangers (PCHEs) have the characteristics of high temperature and high pressure resistance, as well as compact structure, so they are widely used in the supercritical carbon dioxide (S-CO2) Brayton cycle. In order to fully study the heat transfer process of the Z-type PCHE, a numerical model of traditional Z-type PCHE was established and the accuracy of the model was verified. On this basis, a new type of spiral PCHE (S-ZPCHE) is proposed in this paper. The segmental design method was used to compare the pressure changes under 5 different spiral angles, and it was found that increasing the spiral angle θ of the spiral structure will reduce the pressure drop of the fluid. The effects of different spiral angles on the thermal-hydraulic performance of S-ZPCHE were compared. The results show that the pressure loss of fluid is greatly reduced, while the heat transfer performance is slightly reduced, and it was concluded that the spiral angle of 20° is optimal. The local fluid flow states of the original structure and the optimal structure were compared to analyze the reason for the pressure drop reduction effect of the optimal structure. Finally, the performance of the optimal structure was analyzed under variable working conditions. The results show that the effect of reducing pressure loss of the new S-ZPCHE is more obvious in the low Reynolds number region.


Author(s):  
Ignacio Carvajal-Mariscal ◽  
Florencio Sanchez-Silva ◽  
Georgiy Polupan

In this work the heat transfer and pressure drop experimental results obtained in a two step finned tube bank with conical fins are presented. The tube bank had an equilateral triangle array composed of nine finned tubes with conical fins inclined 45 degrees in respect with the tube axis. The heat exchange external area of a single tube is approximately 0.07 m2. All necessary thermal parameters, inlet/outlet temperatures, mass flows, for the heat balance in the tube bank were determined for different air velocities, Re = 3400–18400, and one constant thermal charge provided by a hot water flow with a temperature of 80 °C. As a result, the correlations for the heat transfer and pressure drop calculation were obtained. The experimental results were compared against the analytical results for a tube bank with annular fins with the same heat exchange area. It was found that the proposed tube bank using finned tubes with conical fins shows an increment of heat transfer up to 58%.


Sign in / Sign up

Export Citation Format

Share Document