Determination of Pressure Drop of Pure Water Flowing Upward Direction in a Double Tube Heat Exchanger Having Smooth and Microfin Tubes

Single phase friction factor and pressure drop behavior of smooth and microfin tubes are studied experimentally. The vertical test section was working as a counter flow double tube heat exchanger with water flowing in the inner smooth and microfin tubes having varying inner diameters and cooling water flowing in the annulus. Pressure drop of water due to cooling in upward flow in inner tubes is determined by experiments. Inner tube mass flow rate was between 0.023 kg/s to 0.100 kg/s while test section inlet temperatures were 40°C and 60°C. Effect of Reynolds number on pressure drop is also investigated and Blasius type friction factor correlations are developed for both smooth and microfin tubes.

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Thermal-Hydraulic Performance and Optimization of Tube Ellipticity in a Plate Fin-And-Tube Heat Exchanger

Journal of Electronic Packaging ◽

10.1115/1.4043482 ◽

2019 ◽

Vol 141 (3) ◽

Author(s):

Hua Zhu ◽

Zhuo Yang ◽

Tariq Amin Khan ◽

Wei Li ◽

Zhijian Sun ◽

...

Keyword(s):

Heat Exchanger ◽

Pressure Drop ◽

Friction Factor ◽

Hydraulic Performance ◽

Pareto Optimal ◽

Maximum Heat ◽

Tube Heat Exchanger ◽

Simulation And Optimization ◽

Colburn Factor ◽

Overall Performance

The flow field inside the heat exchangers is associated with maximum heat transfer and minimum pressure drop. Designing a heat exchanger and employing various techniques to enhance its overall performance has been widely investigated and is still an active research. The application of elliptic tube is an effective alternative to circular tube which can reduce the pressure drop significantly. In this study, numerical simulation and optimization of variable tube ellipticity is studied. The three-dimensional numerical analysis and a multi-objective genetic algorithm (MOGA) with surrogate modeling are performed. Tubes in staggered arrangement in fin-and-tube heat exchanger are investigated for combination of various elliptic ratios and Reynolds numbers. Results show that increasing elliptic ratio increases the friction factor due to increased flow blocking area, however, the effect on the Colburn factor is not significant. Moreover, tube with lower elliptic ratio followed by higher elliptic ratio tube has better thermal-hydraulic performance. To achieve the best overall performance, the Pareto optimal strategy is adopted for which the computational fluid dynamics (CFD) results, artificial neural network (ANN), and MOGA are combined. The tubes elliptic ratio and Reynolds number are the design variables. The objective functions include Colburn factor (j) and friction factor (f). The CFD results are input into ANN model. Once the ANN is computed, it is then used to estimate the model responses as a function of inputs. The final trained ANN is used to drive the MOGA to obtain the Pareto optimal solution. The optimal values of these parameters are finally presented.

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Experimental determination of shell side heat transfer coefficient and pressure drop for an oil cooler shell-and-tube heat exchanger with three different tube bundles

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2006.07.023 ◽

2007 ◽

Vol 27 (5-6) ◽

pp. 1001-1008 ◽

Cited By ~ 15

Author(s):

R. Hosseini ◽

A. Hosseini-Ghaffar ◽

M. Soltani

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Heat Exchanger ◽

Pressure Drop ◽

Shell Side ◽

Tube Heat Exchanger ◽

Oil Cooler ◽

Tube Bundles ◽

Shell And Tube

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Investigation and Development of Proposed General Pressure Drop and Heat Transfer Correlations for Laminar Flow in a Toroidal Coiled Tube System

Process Industries ◽

10.1115/imece2004-59872 ◽

2004 ◽

Author(s):

Anthony J. Bowman ◽

Hyunjae Park

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Pressure Drop ◽

Laminar Flow ◽

Friction Factor ◽

Radius Of Curvature ◽

Straight Tube ◽

Coiled Tube ◽

Tube Heat Exchanger ◽

Curved Tube

In this paper, the laminar flow pressure drop and heat transfer correlations published and applied to plain, coiled tube heat exchanger systems are extensively investigated. It was found that most correlations obtained for toroidal geometric systems have been applied to the analysis of helical and spiral tube systems. While toroidal (and helical) coils have a constant radius of curvature about the coil center-point (and center-line), spiral coils have a continuously varying radius of curvature, in which the flow does not reach a typical fully developed flow condition. The centrifugal forces, arising from the curved flow path, contribute to the enhancement of heat transfer (at the cost of additional pressure drop) over straight tube heat exchangers of the same length. In this paper, using published correlations and available experimental test data for pressure drop and heat transfer in toroidal tube systems, the proposed general correlations are developed by using a filtered-mean multiple regression method. The Coiling Influence Factors for the friction factor and heat transfer, CIFf and CIFh, respectively; defined and used in the authors’ previous works [1,2,3] it was found that the deviations between the proposed and published correlations are within about 3% for friction factor and 5–20% for heat transfer, depending on working fluid. In order to assess the validity of applying the generalized correlations developed in this work for toroidal tube systems, onto other curved tube systems, a numerical analysis of toroidal coil systems, using the commercially available CFD package (Fluent 6) has been explicitly performed. A comparison is made between the CFD result for average heat transfer (CIFh) with that predicted by the proposed general correlation for toroidal coils and available experimental data. As an extension of this work, a comparison of curved tube over straight tube heat exchanger effectiveness is made to highlight its use as a design optimization parameter and motivation for additional coiled tube heat exchanger research.

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Thermal-Hydraulic Performance and Optimization of Tube Ellipticity in a Plate Fin-and-Tube Heat Exchanger

ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems ◽

10.1115/ipack2018-8448 ◽

2018 ◽

Author(s):

Zhuo Yang ◽

Tariq Amin Khan ◽

Wei Li ◽

Hua Zhu ◽

Zhijian Sun ◽

...

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Heat Exchanger ◽

Pressure Drop ◽

Friction Factor ◽

Pareto Optimal ◽

Maximum Heat ◽

Tube Heat Exchanger ◽

Maximum Heat Transfer ◽

Colburn Factor

The flow field inside the heat exchangers is associated with maximum heat transfer and minimum pressure drop. Designing a compact heat exchanger and employing various techniques to enhance its overall performance has been widely investigated and still an active research field. However, few researches deal with thermal optimization. The application of elliptic tube is an effective alternative to circular tube which can reduce the pressure drop significantly. In this study, numerical simulation and optimization of variable tube ellipticity is studied at low Reynolds numbers. The three-dimensional numerical analysis and a multi-objective genetic algorithm (MOGA) with surrogate modelling is performed. Two row tubes in staggered arrangement in fin-and-tube heat exchanger is investigated for combination of various elliptic ratio (e = minor axis/major axis) and Reynolds number. Tube elliptic ratio ranges from 0.2 to 1 and Reynolds number ranges from 150 to 750. The tube perimeters are kept constant while changing the elliptic ratio. The numerical model is derived based on continuum flow approach and steady-state conservation equations of mass, momentum and energy. The flow is assumed as incompressible and laminar due to low inlet velocity. Results are presented in the form of Colburn factor, friction factor, temperature contours and streamline contours. Results show that increasing elliptic ratio increases the friction factor due increased flow blocking area, however, the effect on the Colburn factor is not significant. Moreover, tube with lower elliptic ratio followed by higher elliptic ratio tube has better thermal-hydraulic performance. To achieve maximum heat transfer enhancement and minimum pressure drop, the Pareto optimal strategy is adopted for which the CFD results, Artificial neural network (ANN) and MOGA are combined. The tubes elliptic ratio (0.2 ⩽ e ⩽ 1.0) and Reynolds number (150 ⩽ Re ⩽ 750) are the design variables. The objective functions include Colburn factor (j) and friction factor (f). The CFD results are input into ANN model. Once the ANN is computed and its accuracy is checked, it is then used to estimate the model responses as a function of inputs. The final trained ANN is then used to drive the MOGA to obtain the Pareto optimal solution. The optimal values of these parameters are finally presented.

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NUMERICAL INVESTIGATION OF THE EFFECT OF BAFFLE ORIENTATION AND BAFFLE CUT ON HEAT TRANSFER AND PRESSURE DROP OF A SHELL AND TUBE HEAT EXCHANGER

Equipment ◽

10.1615/ihtc13.p18.230 ◽

2006 ◽

Cited By ~ 1

Author(s):

K. Mohammadi ◽

H. Muller-Steinhagen ◽

W. Heidemann

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Pressure Drop ◽

Numerical Investigation ◽

Tube Heat Exchanger ◽

Shell And Tube

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Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

Chemical Product and Process Modeling ◽

10.1515/cppm-2020-0033 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Swanand Gaikwad ◽

Ashish Parmar

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Heat Exchanger ◽

Pressure Drop ◽

Transfer Coefficient ◽

Numerical Results ◽

Shell Side ◽

Tube Heat Exchanger ◽

Shell And Tube ◽

Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

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Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.832.160 ◽

2013 ◽

Vol 832 ◽

pp. 160-165 ◽

Cited By ~ 16

Author(s):

Mohammad Alam Khairul ◽

Rahman Saidur ◽

Altab Hossain ◽

Mohammad Abdul Alim ◽

Islam Mohammed Mahbubul

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Heat Exchanger ◽

Pressure Drop ◽

Transfer Coefficient ◽

Friction Factor ◽

Heat Exchangers ◽

Heat Transfer Performance ◽

Volume Concentration ◽

Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

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