Numerical Analysis for Performance Evaluation of Round Tubes Inserted With Corrugated Twisted Tape

2019 ◽  
Author(s):  
Kalpana Gupta ◽  
Raj Kumar Singh ◽  
Naman Choudhary ◽  
Subham Mukhopadhyay
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Transfer Enhancement ◽  
Friction Factor ◽  
Evaluation Criteria ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Round Tube ◽  
Heat Transfer Augmentation ◽  
Plain Tube

Abstract Varieties of heat transfer enhancement techniques developed by different researchers. Heat transfer augmentation techniques refer to different methods used to increase rate of heat transfer and basically divided into active, passive and compound heat transfer enhancement technique. Use of twisted tape is one such promising passive heat transfer augmentation technique. In this work a novel design of twisted tape is introduced. An attempt has been made to analyze the effect of newly designed twisted tape on heat transfer enhancement using computational Fluid Dynamics (CFD) Techniques. Physical time and energy considered for experimentation will be more so in present work simulation has been carried out using ANSYS FLUENT software to find performance of novel twisted tape. The tape considered here is corrugated twisted tape in which corrugations are given longitudinally with fixed angle of corrugation then it is twisted. Comparison in performance of tube without tape, with plain twisted tape and twisted corrugated tape has been done. Verification of model has been done using available correlations for plain tube and tube with plain twisted tape. Range of Reynolds varied from 10,000 to 60,000. Heat transfer and pressure drop characteristics studied using computational analysis. Nusselt Number and friction factor of round tube with CTT insert is found to be 1.79–1.94 times and 2.5–3.5 times higher respectively compared to round tube without any insert. Thermal performance factor chosen as performance evaluation criteria keeping pumping power constant. Performance of tube with corrugated twisted tape insert found to be better than plain tube (improvement in TPF up to 31%) taking into account both heat transfer and friction factor.

scholarly journals Performance evaluation of tube-in-tube heat exchangers with heat transfer enhancement in the annulus

2006 ◽  
Vol 10 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Ventsislav Zimparov ◽  
Plamen Penchev ◽  
Joshua Meyer
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Evaluation Criteria ◽  
Relative Reduction ◽  
Geometrical Parameters ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Finned Tubes

Different techniques as angled spiraling tape inserts, a round tube in side a twisted square tube and spiraled tube in side the annulus have been used to enhance heat transfer in the annulus of tube-in-tube heat exchangers. The heat transfer enhancement in the shell can be supplemented by heat transfer augmentation in tubes using twisted tape inserts or micro-finned tubes. The effect of the thermal resistance of the condensing refrigerant could also be taken into consideration. To assess the benefit of using these techniques extended performance evaluation criteria have been implemented at different constraints. The decrease of the entropy generation can be combined with the relative in crease of the heat transfer rate or the relative reduction of the heat transfer area to find out the geometrical parameters of the tubes for optimal thermodynamics performance. The results show that in most of the cases considered, the angled spiraling tube insert technique is the most efficient.

scholarly journals CFD Analysis for Heat Transfer Enhancement inside a Circular Tube with Half-Length Upstream and Half-Length Downstream Twisted Tape

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
R. J. Yadav ◽  
A. S. Padalkar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Circular Tube ◽  
Swirl Flow ◽  
Twisted Tape ◽  
Turbulent Regime ◽  
Cfd Analysis ◽  
Transfer Enhancement ◽  
Plain Tube ◽  
Half Length

CFD investigation was carried out to study the heat transfer enhancement characteristics of air flow inside a circular tube with a partially decaying and partly swirl flow. Four combinations of tube with twisted-tape inserts, the half-length upstream twisted-tape condition (HLUTT), the half-length downstream twisted-tape condition (HLDTT), the full-length twisted tape (FLTT), and the plain tube (PT) with three different twist parameters (, 0.27, and 0.38) have been investigated. 3D numerical simulation was performed for an analysis of heat transfer enhancement and fluid flow for turbulent regime. The results of CFD investigations of heat transfer and friction characteristics are presented for the FLTT, HLUTT, and the HLDTT in comparison with the PT case.

scholarly journals Internal Flow Analysis of a Heat Transfer Enhanced Tube with a Segmented Twisted Tape Insert

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 207 ◽  
Author(s):  
Gan Liu ◽  
Chen Yang ◽  
Junhui Zhang ◽  
Huaizhi Zong ◽  
Bing Xu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Friction Factor ◽  
Dominant Role ◽  
Length Ratio ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Constant Wall Temperature ◽  
Advantages And Disadvantages ◽  
Twist Ratio

A heat exchanger is a device that transfers unneeded heat from one region to another, and transferred heat may be fully reused, thus improving energy efficiency. To augment this positive process, many studies and investigations on automation technologies have been performed. Inserts are widely used in pipe flow for heat transfer enhancement, since they can break the boundary layer and promote the heat exchange. Segmented twisted tape, which is applicable in 3D printing, is a novel insert and has potential in heat transfer enhancement. To clarify its advantages and disadvantages, this research presents a numerical investigation of vortex flow and heat enhancement in pipes containing one segmented twisted element. Flow state and heat transfer behaviour are obtained by simulation under constant wall temperature with different Reynolds numbers, ranging from 10,000 to 35,000. The effects of geometric parameters, including twist ratio (P/D = 2.0, 3.3 and 4.6) and length ratio (L/P = 0.3, 0.5 and 0.7), on the Nusselt number (Nu) and friction factor (f) are investigated. Streamline and temperature distribution are presented. Meanwhile, local and overall heat transfer performance is compared with those of a smooth tube, and the overall performance is evaluated by performance evaluation factor (η). The results indicate that the twist ratio (P/D) plays a dominant role in heat transfer enhancement while the length ratio (L/P) also has considerable influence. It is shown that a segmented tape insert can increase the overall heat transfer rate by 23.5% and the friction factor by 235%, while local improvement along the tube can be 2.8 times more than the plain tube.

Numerical Studies on Heat Transfer and Friction Factor Characteristics of a Tube Fitted With Helical Twisted Tape Without Core-Rod Inserts

2010 ◽  
Author(s):  
Zhichun Liu ◽  
Xiaoyu Zhang ◽  
Wei Liu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Friction Factor ◽  
High Efficiency ◽  
Three Dimensional ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Transfer Coefficients ◽  
Turbulence Analysis ◽  
Core Rod

The principles of heat transfer enhancement in the core flow of tube have been proposed to improve the temperature uniformity and reduce flow resistance, which is different from that of heat transfer enhancement in the boundary flow of tube. Helical twisted tape inserts with four different widths (w = 7.5mm, 12mm, 15mm and 20mm) have been investigated for different inlet volume-flow rates ranging from 200L/h to 500L/h. A three-dimensional turbulence analysis of heat transfer and fluid flow is performed by numerical simulation. The simulation results show that the average overall heat transfer coefficients in circular plain tubes are enhanced with helical twisted tape of different widths by as much as 220∼390% at a constant tube-side temperature and the friction factor are enhanced by as much as 50% to 790%. The PEC value of the helical twisted tape inserts of different width varies between 1.60 and 3.15. Physical quantity synergy analysis is also performed. The synergy angles α, β, γ and θ are calculated, and the numerical results verify the synergy regulation among physical quantities of fluid particle in the flow field of convective heat transfer, which can guide the optimum design for better heat transfer units and high-efficiency heat exchangers.

Performance Evaluation Criteria in Heat Transfer Enhancement

2020 ◽  
Author(s):  
Sujoy Kumar Saha ◽  
Hrishiraj Ranjan ◽  
Madhu Sruthi Emani ◽  
Anand Kumar Bharti
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Transfer Enhancement ◽  
Evaluation Criteria ◽  
Transfer Enhancement

Comparative Performance of Rippled Fin Plate Fin and Tube Heat Exchangers

1989 ◽  
Vol 111 (1) ◽  
pp. 21-28 ◽  
Author(s):  
J. D. Maltson ◽  
D. Wilcock ◽  
C. J. Davenport
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Wind Tunnel ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Evaluation Criteria ◽  
Performance Characteristics ◽  
Published Data ◽  
Transfer Enhancement ◽  
Comparative Performance

Continuous rippled fins are preferred to interrupted fins in applications where fouling by fibrous matter or insects is a problem. The performance characteristics of three rippled fin heat exchangers have been measured in a thermal wind tunnel. The results of these measurements are reported and comparisons are made with published data on similar surfaces. The performance evaluation criteria used as the basis for the comparisons were those recommended by Shah (1978). The tested rippled fin surfaces were found to have a higher performance than a similar surface reported in Kays and London (1984). The heat transfer enhancement was found to be dependent upon the profile of the fin.

scholarly journals Heat Transfer Enhancement of Laminar Nanofluids Flow in a Circular Tube Fitted with Parabolic-Cut Twisted Tape Inserts

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Sami D. Salman ◽  
Abdul Amir H. Kadhum ◽  
Mohd S. Takriff ◽  
Abu Bakar Mohamad
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Friction Factor ◽  
Cfd Simulation ◽  
Volume Fraction ◽  
Swirl Flow ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Twist Ratio ◽  
Cut Depth

Numerical investigation has been carried out on heat transfer and friction factor characteristics of copper-water nanofluid flow in a constant heat-fluxed tube with the existence of new configuration of vortex generator using Computational Fluid Dynamics (CFD) simulation. Two types of swirl flow generator: Classical twisted tape (CTT) and Parabolic-cut twisted tape (PCT) with a different twist ratio (y= 2.93, 3.91 and 4.89) and different cut depth (w= 0.5, 1.0 and 1.5 cm) with 2% and 4% volume concentration of CuO nanofluid were used for simulation. The effect of different parameters such as flow Reynolds number, twist ratio, cut depth and nanofluid were considered. The results show that the enhancement of heat transfer rate and the friction factor induced by the Classical (CTT) and Parabolic-cut (PCT) inserts increases with twist ratio and cut depth decreases. The results also revealed that the heat transfer enhancement increases with an increase in the volume fraction of the CuO nanoparticle. Furthermore, the twisted tape with twist ratio (y= 2.93) and cut depthw= 0.5 cm offered 10% enhancement of the average Nusselt number with significant increases in friction factor than those of Classical twisted tape.

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