Optimal design of a double pipe heat exchanger based on the outward helically corrugated tube

Wang, Wei; Zhang, Yaning; Lee, Kwan-Soo; Li, Bingxi

doi:10.1016/j.ijheatmasstransfer.2019.01.115

Cited by 73 publications

(21 citation statements)

References 38 publications

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“…where the subscript "0" denotes interrupted microchannel without ribs. If PEC > 1, the enhanced overall heat transfer performance is superior compared to the IMCHS-NR [23].…”

Section: Data Reductionmentioning

confidence: 99%

Analysis of laminar flow and heat transfer in an interrupted microchannel heat sink with different shaped ribs

Wang

Zhang

et al. 2019

J Therm Anal Calorim

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A numerical study was conducted to investigate the mechanism of laminar flow and heat transfer enhancement in an interrupted microchannel heat sink (IMCHS) with different shaped ribs at Reynolds number ranging from 100 to 900. The global flow features, heat transfer and friction for IMCHS with no ribs, rectangle ribs, triangle ribs and trapezoid ribs are detailed compared. The results show that the local heat transfer and friction performance of IMCHS with ribs show significant increase at the windward side of the ribs. Additionally, the smaller the chamfer of ribs, the larger average heat transfer and friction performance. For IMCHS with rectangle ribs, the maximum increment of Nu and f can reach to 1.81 and 2.59, respectively. Concerning the overall heat transfer performance (PEC), the trapezoid ribs show the best behavior with PEC = 1.65-1.38 at Re = 100-900. Keywords Interrupted microchannel heat sink • Different rib shapes • Numerical simulation • Overall heat transfer performance List of symbols Cp Specific heat (J kg −1 K −1) De Hydraulic diameter (mm) f Darcy friction factor h Heat transfer coefficient (W m −2 K −1) L Length (m) Nu Nusselt number P Pressure (Pa) PEC Overall heat transfer performance Pr Prandtl number q Average heat flux (W m −2) Re Reynolds number T Temperature (K) u Velocity (m s −1) x, y, z Three coordinates shown in Fig. 1 ΔP Pressure drop (Pa) Greek letters λ Thermal conductivity (W m −1 K −1) μ Dynamic viscosity (kg m −1 s −1) ρ Density (kg m −3) Subscripts ave Average value f Fluid i, j, k Directions of the coordinate system in Inlet local Local value out Outlet w Wall 0 Reference value * Bingxi Li

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“…where the subscript "0" denotes interrupted microchannel without ribs. If PEC > 1, the enhanced overall heat transfer performance is superior compared to the IMCHS-NR [23].…”

Section: Data Reductionmentioning

confidence: 99%

Analysis of laminar flow and heat transfer in an interrupted microchannel heat sink with different shaped ribs

Wang

Zhang

et al. 2019

J Therm Anal Calorim

Self Cite

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“…These parameters are Bejan number ( B ) and DEG ratio ( ) which are used to assess the contribution of the thermal and fictional terms in total entropy generation and defined as Eqs. (9) and (10), respectively [42][43][44].…”

Section: Thermo-hydraulic Modelingmentioning

confidence: 99%

“…Like other types of HEs, changing geometric parameters is one of the main priorities for improving the performance of DPHEs [7,8]. In one of the recently published works in this area, Wang et al [9] considered an outward helically corrugated tube as the inner pipe of a DPHE. They applied CFD method and also a multiobjective optimization targeting the heat transfer and pressure drop characteristics.…”

Section: Introductionmentioning

confidence: 99%

A comprehensive thermo-hydraulic analysis and optimization of turbulent TiO2/W-EG nano-fluid flow inside double-pipe heat exchangers with helical coil inserts

Ebrahimi‐Moghadam

Gohari

Hoseinzade

et al. 2020

J Braz. Soc. Mech. Sci. Eng.

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The main aim in current work is to optimize TiO 2 /W-EG nano-fluid (with 60 vol% of water and 40 vol% of ethylene glycol) flow within the inner tube of the double-pipe heat exchangers with helical coil inserts. The entropy generation is selected as the target function and is to be minimized. To reach this goal, at the first step, a comprehensive sensitivity analysis is carried out taking into account all of the nano-fluid flow conditions (including nanoparticle volume fraction , Reynolds number Re and Prandtl number Pr) and geometric parameters of the helical coil inserts (including thepitch-to-diameter ratio of coil Π). Afterward, the genetic algorithm (GA) is utilized in the optimization process. The results of sensitivity analysis reveal that and Π , respectively, have the highest and lowest impact on the thermodynamics characteristics. Also, the addition of up to 0.02 vol% nanoparticles leads to a maximum of 13.93% improvement in dimensionless entropy generation (DEG). The outputs of the GA are opt = 0.0198%, Re opt = 8421.173, Pr opt = 32.833, Π opt = 2.437 and DEG opt = 0.005086. Furthermore, based on the optimization results, a useful correlation is proposed to find the optimum geometry of the helical coil based on the nano-fluid flow conditions.

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“…They found that the value of JF can be up to 1.43 for all the investigated cases when the longitudinal phase-shifting of the tube is equal to 1/8. Wang et al [27] numerically studied a DPHE by employing an outward helical corrugated tube as the inner tube. They found that secondary and swirling flows are generated on the sides of the tube and shell, and the optimum geometric parameter is obtained at the shell diameter of 38 mm.…”

Section: Of 15mentioning

confidence: 99%

Heat Transfer Enhancement in a Novel Annular Tube with Outer Straight and Inner Twisted Oval Tubes

Luo,

Song,

Tagawa

et al. 2020

Symmetry

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The thermal-hydraulic performance in a novel annular tube formed by outer straight and inner twisted oval tubes is numerically investigated. An annular tube formed by two straight oval tubes is also studied for comparison. Inner twisted oval tubes with different aspect ratios and twist ratios are studied. The heat transfer is well improved by the symmetrical secondary flow in the annulus. The Nusselt number generally increases when the inner oval tube becomes flatter and the twists stronger in the studied range of geometrical parameters. The largest Nusselt number Nu of the inner twisted tube increases by 116% while the friction factor f increases by only 46% compared with that of the inner straight tube, and the largest value of the thermal performance factor (JF) can be up to 1.9. Correlations of the Nusselt number and friction factor are proposed for laminar and turbulent flows, and the deviations of the correlations are within ±5% and ±4% for Nu and f, respectively.

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Optimal design of a double pipe heat exchanger based on the outward helically corrugated tube

Cited by 73 publications

References 38 publications

Analysis of laminar flow and heat transfer in an interrupted microchannel heat sink with different shaped ribs

Analysis of laminar flow and heat transfer in an interrupted microchannel heat sink with different shaped ribs

A comprehensive thermo-hydraulic analysis and optimization of turbulent TiO2/W-EG nano-fluid flow inside double-pipe heat exchangers with helical coil inserts

Heat Transfer Enhancement in a Novel Annular Tube with Outer Straight and Inner Twisted Oval Tubes

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