Thermal Performance With Entropy Generation Analysis of Fluid Flow in a Heat Exchanger Pipe With Single and Double Strip Helical Screw Tape Inserts

2020 ◽  
Author(s):  
Shashank Ranjan Chaurasia ◽  
R. M. Sarviya
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Entropy Generation ◽  
Thermal Performance ◽  
Twisted Tape ◽  
Maximum Enhancement ◽  
Twist Ratio ◽  
Single Strip

Abstract In heat exchangers, twisted tape insert is a technique to enhance heat transfer. In this paper, the experimental investigation is arranged to analyse thermal performance and entropy generation analysis on fluid flow in helical screw inserts with number of strips. The Nusselt number is achieved enhancement with double strip as compared to single strip helical screw inserts at decreased values of twist ratio and increased values of flow rates. The Nusselt number is achieved maximum enhancement of 112% with double strip helical screw insert than plain tube at 4000 of Reynolds number, whereas it is found higher value at Reynolds number of 16000. The common correlations of Nusselt number and friction factor with repect of Reynolds number, number of the strips and twist ratio are generated. The entropy generation analysis is also performed. The thermal performance factor is found increment with double strip than single strip helical screw inserts at twist ratio of 2.5 and 3, whereas, it is attained maximum value of 1.5 at twist ratio 2.5 and Reynolds number of 16000 with double strip helical screw insert. The double strip helical screw inserts are suitable for reducing the size of heat exchanger, which could dercrease the size of many thermal applications as solar water heater, radiator, electronic cooling systems.

Numerical and experimental thermal performance with entropy generation analysis on tube with helical screw tape inserts at number of strips in turbulent flow

2020 ◽  
pp. 095440622093773
Author(s):  
Shashank Ranjan Chaurasia ◽  
RM Sarviya
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Entropy Generation ◽  
Thermal Performance ◽  
Twisted Tape ◽  
Maximum Enhancement ◽  
Twist Ratio ◽  
Plain Tube ◽  
Volume Method ◽  
Single Strip

In the heat exchangers, twisted tape insert is a technique to enhance heat transfer. In this paper, the experimental and numerical investigations are arranged to analyze thermal performance with entropy generation analysis on single and double strip helical screw tape inserts. The finite volume method is used with shear stress transport K-ω model to analyze fluid flow in tube with inserts. The Nusselt number attained enhancement with double strip as compared to single strip helical screw inserts at decreased values of twist ratio and increased values of Reynolds number. However, the Nusselt number attained maximum enhancement of 112% with double strip helical screw insert than plain tube at 4000 of Reynolds number (Re). The common correlations for Nusselt number and friction factor are generated with respect to Reynolds number, number of the strips and twist ratio. Entropy generation analysis is also performed. The thermal performance factor attained its enhancement with double strip than single strip helical screw inserts at twist ratio of 2.5 and 3; whereas, double strip helical screw insert attained maximum value of 1.5 at twist ratio of 2.5 and Reynolds number of 16000. The double strip helical screw inserts are suitable for miniaturization of heat exchanger.

Thermal-Hydraulic Performance Analysis of Fluid Flow in Tube With Helical Screw Inserts in Transition Flow

2020 ◽  
Author(s):  
Shashank Ranjan Chaurasia ◽  
R. M. Sarviya
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Fluid Flow ◽  
Performance Analysis ◽  
Hydraulic Performance ◽  
Transition Flow ◽  
Maximum Enhancement ◽  
Transition Flow Regime ◽  
Twist Ratio ◽  
Single Strip

Abstract An experimental analysis is arranged to evaluate thermal hydraulic performance analysis on fluid flow in helical screw inserts in tube with number of strips and different twist ratios in Transition flow regime. Single strip insert is also compared with double strip inserts of helical screw inserts with three values of twist ratios. Heat transfer enhancement is achieved with fluid flow in double strip as compared to single strip helical screw insert at decreases values of twist ratios and increases values of Reynolds number (Re). Maximum enhancement in the value of Nusselt number is achieved with double strip inserts at low value of twist ratio and Reynolds number as compared to Single strip inserts. Common correlations of Nusselt number and friction factor are generated. Thermal performance factor (TPF) is achieved maximum values with double strip insert at all flow rates at 2.5 of twist ratio than single strip inserts. Double strip inserts show suitability of helical screw insert in heat exchangers to compact the size of thermal applications.

Experimental and numerical thermal performance analysis with exergy destruction on nanofluid flow in tube with double strip helical screw inserts

2021 ◽  
pp. 095765092098214
Author(s):  
Shashank Ranjan Chaurasia ◽  
RM Sarviya
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Thermal Performance ◽  
Power Plants ◽  
Exergy Destruction ◽  
Water Heater ◽  
Nanofluid Flow ◽  
Maximum Enhancement ◽  
Twist Ratio ◽  
Single Strip

Experimental and numerical analysis is arranged with exergy destruction to evaluate thermal performance of system on nanofluid flow in tube with single and double strip helical screw inserts at different values of twist ratio in laminar flow regime. CFD analysis has occurred on the fluent workbench of ANSYS software. The Nusselt number attained enhancement with the flow of nanofluid in double strip helical screw inserts as compared with single strip helical screw inserts at decreasing values of twist ratio and increasing values of Reynolds number. Maximum enhancement of 421% is found with Nusselt number in the flow of nanofluid in tube with double strip helical screw insert at 1.5 of twist ratio and lower value of Reynolds number as compared with the flow of water in plain tube. Common correlations of Nusselt number and friction factor are generated. Exergy destruction number is attained less than one value for both types of inserts at different values of twist ratio and Reynolds number, whereas attained lower value with the flow of nanofluid in tube with double strip helical screw insert at twist ratio of 1.5 and low value of Reynolds number. Heat transfer enhancement number is attained more than one value for both types of inserts with different values of twist ratio and Reynolds number, whereas double strip helical screw inserts attained maximum value at twist ratio of 1.5 in the range of Reynolds number. Therefore, double strip helical screw inserts are the best inserts as compared with single strip helical screw inserts to compact the size of heat exchangers, whereby size of many thermal applications could be compact such as solar water heater, electronic cooling devices, automobile radiator, power plants etc.

Comparative Thermal Performance Analysis on Helical Screw Insert in Tube With Number of Strips With Nanofluid at Laminar Flow Regime

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Shashank Ranjan Chaurasia ◽  
R. M. Sarviya
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Laminar Flow ◽  
Flow Regime ◽  
Thermal Performance ◽  
Power Plants ◽  
Nanofluid Flow ◽  
Laminar Flow Regime ◽  
Twist Ratio ◽  
Single Strip

Abstract The experimental analysis is arranged to evaluate the thermal hydraulic performance on nanofluid flow in helical screw insert with tube at a number of strips and different twist ratios in laminar flow regime. The single strip (SS) helical screw inserts are also compared with the double strip (DS) helical screw inserts. The heat transfer enhancement is achieved with nanofluid flow in double strip as compared with single strip helical screw insert at decreased values of twist ratio and increased values of Reynolds number. A maximum enhancement of 421% is found in the value of Nusselt number with double strip helical screw insert at twist ratio of 1.5 and low value of Reynolds number in the flow of nanofluid than water in plain tube. The common correlations of Nusselt number and friction factor are generated. The thermal performance factor (TPF) is achieved at a maximum value of 2.42 with double strip than single strip helical screw inserts at twist ratio of 2.5 and low value of Reynolds number. The present analysis shows suitability of the double strip helical screw insert to enable miniaturization of the heat exchangers. A compact heat exchanger decreases the size of thermal application such as solar water heater, solar power plants, electronic cooling systems, radiator, etc., which could save environment by pollution reduction with utilization of energy.

Experimental analysis on thermal and friction factor characteristics of fluid flow in tube with novel double strip helical screw tape

2019 ◽  
Vol 234 (6) ◽  
pp. 874-886
Author(s):  
Shashank R Chaurasia ◽  
RM Sarviya
Keyword(s):  
Nusselt Number ◽  
Fluid Flow ◽  
Friction Factor ◽  
Experimental Analysis ◽  
Flow Characteristics ◽  
Performance Ratio ◽  
Working Fluid ◽  
Flow Rates ◽  
Twist Ratio ◽  
Single Strip

An experimental analysis has been carried out to investigate the thermal and friction factor characteristics of fluid flow in a tube with double strip helical screw tape (DS-HST) inserts with different values of twist ratio and compared with single strip helical screw tape inserts and plain tube. Water is used as a working fluid at different flow rates with constant heat flux conditions. CFD analysis is also carried out to visualize thermal and fluid flow characteristics of fluid flow in tube with inserts. Experimental results have showed that Nusselt number and friction factor have attained excellent enhancement with double strip helical screw tape inserts in the range of flow rates than single strip helical screw tape inserts at the value of twist ratio 1.5. Correlation is also developed for Nusselt number with a range of Reynolds number, twist ratio and number of strips. Moreover, the performance ratio has attained maximum value at twist ratio of 2.5 with high values of flow rate. It is concluded that DS-HST is able to attain enhancement in the efficiency of heat exchanger, causing a reduction in size for thermal applications.

scholarly journals Evaluation of Multiple Semi-Twisted Tape Inserts in a Heat Exchanger Pipe Using Al2O3 Nanofluid

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1570
Author(s):  
Yongfeng Ju ◽  
Tiezhu Zhu ◽  
Ramin Mashayekhi ◽  
Hayder I. Mohammed ◽  
Afrasyab Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Base Fluid ◽  
Average Nusselt Number ◽  
Three Dimensions ◽  
Twisted Tape ◽  
Twisted Tapes

The hydrothermal performance of multiple semi-twisted tape inserts inside a heat exchanger pipe is numerically examined in three-dimensions. This study aims to find the optimum case for having the highest heat transfer enhancement with the lowest friction factor using nanofluid (Al2O3/water). A performance evaluation criterion (PEC) is defined to characterize the performance based on both friction factor and heat transfer. It was found that increasing the number of semi-twisted tapes increases the number of swirl flow streams and leads to an enhancement in the local Nusselt number as well as the friction factor. The average Nusselt number increases from 15.13 to 28.42 and the average friction factor enhances from 0.022 to 0.052 by increasing the number of the semi-twisted tapes from 0 to 4 for the Reynolds number of 1000 for the base fluid. By using four semi-twisted tapes, the average Nusselt number increases from 12.5 to 28.5, while the friction factor reduces from 0.155 to 0.052 when the Reynolds number increases from 250 to 1000 for the base fluid. For the Reynolds number of 1000, the increase in nanofluid concentration from 0 to 3% improves the average Nusselt number and friction factor by 6.41% and 2.29%, respectively. The highest PEC is equal to 1.66 and belongs to the Reynolds number of 750 using four semi-twisted tape inserts with 3% nanoparticles. This work offers instructions to model an advanced design of twisted tape integrated with tubes using multiple semi-twisted tapes, which helps to provide a higher amount of energy demand for solar applications.

scholarly journals Thermo-Hydraulic Performance Analysis on the Effects of Truncated Twisted Tape Inserts in a Tube Heat Exchanger

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1652
Author(s):  
Mehdi Ghalambaz ◽  
Ramin Mashayekhi ◽  
Hossein Arasteh ◽  
Hafiz Muhammad Ali ◽  
Pouyan Talebizadehsardari ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Tube Heat Exchanger ◽  
Twisted Tapes ◽  
Plain Tube

This paper investigates the convective heat transfer in a heat exchanger equipped with twisted tape elements to examine effects of the twisted tape truncation percentage, pitch value, position and Reynolds number using 3D numerical simulation. A symmetric heat flux is applied around the tube as the studied heat exchanger. Based on the influences in both heat transfer enhancement and pressure drop, the performance evaluation criterion (PEC) is utilized. Inserting twisted tape elements and reducing the pitch value significantly augment the Nusselt number, friction coefficient and PEC number compared to the plain tube. For the best case with a Reynolds number of 1000, the average Nusselt number increases by almost 151%, which is the case of fully fitted twisted tape at a pitch value of L/4. Moreover, increasing the twisted tape truncation percentage reduces both heat transfer and pressure drop. Furthermore, the highest heat transfer rate is achieved when the truncated twisted tape is located at the entrance of the tube. Finally, it is concluded that for P = L, L/2, L/3 and L/4, the optimum cases from the viewpoint of energy conservation are twisted tapes with truncation percentages of 75, 50, 50 and 0%, in which the related PEC numbers at a Reynolds number of 1000 are almost equal to 1.08, 1.24, 1.4 and 1.76, respectively.

scholarly journals Comparative Studies on Thermal Performance of Conic Cut Twist Tape Inserts with SiO2and TiO2Nanofluids

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Sami D. Salman ◽  
Abdul Amir H. Kadhum ◽  
Mohd S. Takriff ◽  
Abu Bakar Mohamad
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Thermal Performance ◽  
Volume Concentration ◽  
Twisted Tape ◽  
Maximum Heat ◽  
Performance Factor ◽  
Thermal Performance Factor ◽  
Maximum Heat Transfer ◽  
Twist Ratio

This paper presents a comparison study on thermal performance conic cut twist tape inserts in laminar flow of nanofluids through a constant heat fluxed tube. Three tape configurations, namely, quadrant cut twisted tape (QCT), parabolic half cut twisted tape (PCT), and triangular cut twisted (VCT) of twist ratioy= 2.93 and cut depthde= 0.5 cm were used with 1% and 2% volume concentration of SiO2/water and TiO2/water nanofluids. Typical twist tape with twist ratio ofy= 2.93 was used for comparison. The results show that the heat transfer was enhanced by increasing of Reynolds number and nanoparticles concentration of nanofluid. The results have also revealed that the use of twist tape enhanced the heat transfer coefficient significantly and maximum heat transfer enhancement was achieved by the presence of triangular cut twist tape insert with 2% volume concentration of SiO2nanofluid. Over the range investigated, the maximum thermal performance factor of 5.13 is found with the simultaneous use of the SiO2nanofluid at 2% volume concentration VCT at Reynolds number of 220. Furthermore, new empirical correlations for Nusselt number, friction factor, and thermal performance factor are developed and reported.

scholarly journals STUDI EKSPERIMENTAL PENINGKATAN PERPINDAHAN PANAS ALIRAN TURBULEN PADA PENUKAR KALOR PIPA KONSENTRIK DENGAN PERFORATED TWISTED TAPE INSERT WITH PARALLEL WINGS

ROTASI ◽  
2015 ◽  
Vol 17 (3) ◽  
pp. 120
Author(s):  
Indri Yaningsih ◽  
Tri Istanto ◽  
Wibawa Endra Juwana
Keyword(s):  
Nusselt Number ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Thermal Performance ◽  
Working Fluid ◽  
Twisted Tape ◽  
Depth Ratio ◽  
Performance Factor ◽  
Thermal Performance Factor ◽  
Pipe Heat

Heat transfer, flow friction and thermal performance factor characteristics in a concentric pipe heat exchanger fitted perforated twisted tape insert with parallel wings (PTPW), using water as working fluid are investigated experimentally. The design of PTPW involves the following concepts: (1) wings induce an extra turbulence near tube wall and thus efficiently disrupt a thermal boundary layer (2) holes existing along a core tube, diminish pressure loss within the tube. The experiments are conducted using the PTPW with the three wing depth ratio (w/W = 0.16, 0.24 and 0.32) and constant the hole diameter ratio (d/W) of 0.24 over a Reynolds number range of 5800–18,500. A typical twisted tape insert (TT) was also tested for a comparison. The results show that both mean Nusselt number and mean friction factor associated by all twisted tape are consistently higher than those without twisted tape (plain tube). It is also found that Nusselt number, friction factor and thermal performance factor increase with increasing wing depth ratio. Over the range considered, Nusselt number and friction factor in a concentric pipe heat exchanger with the PTPW are, respectively, 1.14–1.42 and 1.12–1.40 times of those in the tube with typical twisted tape (TT).

Sensitivity Analysis of a Heat Exchanger Tube Fitted With Cross-Cut Twisted Tape With Alternate Axis

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
M. E. Nakhchi ◽  
J. A. Esfahani
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Diameter Ratio ◽  
Design Parameters ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Numerical simulations are used to analyze the thermal performance of turbulent flow inside heat exchanger tube fitted with cross-cut twisted tape with alternate axis (CCTA). The design parameters include the Reynolds number (5000<Re<15,000), cross-cut width ratio (0.7<b/D<0.9), cross-cut length ratio (2<s/D<2.5), and twist ratio (2<y/D<4). The objective functions are the Nusselt number ratio (Nu/Nus), the friction factor ratio (f/fs), and the thermal performance (η). Response surface method (RSM) is used to construct second-order polynomial correlations as functions of design parameters. The regression analysis shows that heat transfer ratio decreased with increasing both the Reynolds number and the width to diameter ratio of the twisted tape. This means that the twisted tape has more influence on heat transfer at smaller inlet fluid velocities. Sensitivity analysis reveals that among the effective input parameters, the sensitivity of Nu/Nus to the Reynolds number is the highest. The results reveal that thermal performance enhances with increasing the width to diameter ratio of the twisted tape (b/D). The maximum thermal performance factor of 1.531 is obtained for the case of Re=5000, b/D=0.9, s/D=2.5, and y/D=4.

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