A Semi Empirical Methodology for Performance Estimation of a Double Pipe Finned Heat Exchanger

2008 ◽  
Author(s):  
G. Arvind Rao ◽  
Yeshyahou Levy
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Operating Conditions ◽  
Performance Estimation ◽  
Wide Range ◽  
Double Pipe ◽  
Semi Empirical ◽  
Pipe Heat

Finned tubes are one of the most widely used means of passively enhancing the heat transfer in circular tubes. Many investigators have proposed different correlations for predicting the performance of such heat exchangers based on their experimental investigations. However, the practical usage of such correlations is limited because of the variety of parameters that can influence Nusselt number and friction factor. Most of the correlations either have been developed with limited databases, or are geometry specific. Using CFD for analyzing performance of such heat exchangers is very computational intensive and hence cannot practically be applied for design optimization purposes. On the other hand, empirical correlations have many limitations in terms of their applicability. The objective of the present article is to present a physically based model for evaluating heat transfer and frictional loss for an internally and / or externally finned double pipe heat exchanger that can be applied in a wide range of operating conditions of practical importance. This paper describes a simple semi-empirical-numerical methodology to evaluate heat transfer and pressure drop characteristics in a finned tube heat exchanger with internal and/or external fins. Conduction and turbulent forced convection are the prominent modes of heat transfer. In order to resolve the operational characteristics of double pipe finned heat exchangers, a numerical methodology is presented which uses well known existing correlations for flow in a smooth pipe and flow over a flat plate. The method of successive substitution is used to solve the problem numerically. The proposed methodology is applied to some simple cases and the results compare well with existing data and correlations available in the literature. It is found that the addition of fins to such double pipe heat exchangers reduce the Nusselt Number; however the corresponding heat transfer rate is enhanced owing to the increase in the overall heat transfer area.

Thermal–Hydraulic Performance Analysis of a Convergent Double Pipe Heat Exchanger

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Ahmed T. Al-Sammarraie ◽  
Kambiz Vafai
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Hydraulic Performance ◽  
Operating Conditions ◽  
Contraction Ratio ◽  
Wide Range ◽  
Prandtl Numbers ◽  
Double Pipe ◽  
The Impact ◽  
Pipe Heat

The present investigation proposes an innovative convergent double pipe heat exchanger (C-DPHE). A two-dimensional (2D) axisymmetric heat transfer model with counterflow is employed to analyze the thermal and hydraulic performance of this configuration numerically. The impact of convergence in the flow direction, using a wide range of contraction ratio (Cr), is explored. The effect of Reynolds and Prandtl numbers on the flow and heat transfer is addressed, as well. The model results were validated with available data from the literature, and an excellent agreement has been confirmed. In general, the findings of the present study indicate that increasing the contraction ratio increases heat transfer and pressure drop in the C-DPHE. Moreover, this configuration has a prominent and sustainable performance, compared to a conventional double pipe heat exchanger (DPHE), with an enhancement in heat transfer rate up to 32% and performance factor (PF) higher than one. Another appealing merit for the C-DPHE is that it is quite effective and functional at low Reynolds and high Prandtl numbers, respectively, since no high-operating pumping power is required. Further, the optimal operating conditions can be established utilizing the comprehensive information provided in this work.

scholarly journals Performance Enhancement of Double Pipe Heat Exchanger with Helical Fin and Vortex Generator using CFD

2019 ◽  
Vol 9 (2) ◽  
pp. 2677-2681
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Water Vapour ◽  
Food Processing ◽  
Heat Exchangers ◽  
Performance Enhancement ◽  
Delta Wing ◽  
Vortex Generator ◽  
Double Pipe ◽  
Pipe Heat

Transferring heat from one fluid to another fluid without losing of major energy is a challenging task in the food processing and other industries. Double Pipe Heat Exchanger (DPHE) are light capacity Heat Exchangers (HE) used for air and other gas applications. In the present work an attempt is made to enhance the heat transfer of DPHE with helical fins and vortex generator. The working fluids are air and steam (water vapour) along outer and inner pipes. The parameters considered are helix angles, i.e. 350 , 400 , & 450 and pitch size i.e. 80 mm, 75 mm and 70 mm, and a vertex generator. CATIA V5 and Autodesk CFD are used for modelling and analysis. It is found that 400 angle helix fin 70 mm pitch along Delta Wing type (Triangular) vortex generator (VG) gives best performance

scholarly journals Heat Transfer of Nanofluid in a Double Pipe Heat Exchanger

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Reza Aghayari ◽  
Heydar Maddah ◽  
Malihe Zarei ◽  
Mehdi Dehghani ◽  
Sahar Ghanbari Kaskari Mahalle
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Volume Fraction ◽  
Theoretical Data ◽  
Experimental Results ◽  
Double Pipe ◽  
Pipe Heat

This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%–0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigated. Comparison of experimental results with valid theoretical data based on semiempirical equations shows an acceptable agreement. Experimental results show a considerable increase in heat transfer coefficient and Nusselt number up to 19%–24%, respectively. Also, it has been observed that the heat transfer coefficient increases with the operating temperature and concentration of nanoparticles.

Turbulent flows in a spiral double-pipe heat exchanger

2019 ◽  
Vol 30 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Zhe Tian ◽  
Ali Abdollahi ◽  
Mahmoud Shariati ◽  
Atefeh Amindoust ◽  
Hossein Arasteh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Turbulent Flows ◽  
Heat Exchangers ◽  
Volume Fraction ◽  
Inlet Temperature ◽  
Content Type ◽  
Tube Heat Exchanger ◽  
Double Pipe ◽  
Pipe Heat

Purpose This paper aims to study the fluid flow and heat transfer through a spiral double-pipe heat exchanger. Nowadays using spiral double-pipe heat exchangers has become popular in different industrial segments due to its complex and spiral structure, which causes an enhancement in heat transfer. Design/methodology/approach In these heat exchangers, by converting the fluid motion to the secondary motion, the heat transfer coefficient is greater than that of the straight double-pipe heat exchangers and cause increased heat transfer between fluids. Findings The present study, by using the Fluent software and nanofluid heat transfer simulation in a spiral double-tube heat exchanger, investigates the effects of operating parameters including fluid inlet velocity, volume fraction of nanoparticles, type of nanoparticles and fluid inlet temperature on heat transfer efficiency. Originality/value After presenting the results derived from the fluid numerical simulation and finding the optimal performance conditions using a genetic algorithm, it was found that water–Al2O3 and water–SiO2 nanofluids are the best choices for the Reynolds numbers ranging from 10,551 to 17,220 and 17,220 to 31,910, respectively.

Numerical Investigation on the Conjugate Heat Transfer in Double-Pipe Heat Exchangers With Propane Flow Boiling

Volume 3 ◽  
2004 ◽  
Author(s):  
Xuelei Chen ◽  
Mauricio A. Sa´nchez ◽  
William H. Sutton
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Computer Program ◽  
Heat Exchangers ◽  
Conjugate Heat Transfer ◽  
Flow Boiling ◽  
Experiment Data ◽  
Composite Fuel ◽  
Double Pipe ◽  
Pipe Heat

This investigation is part of the composite fuel project in the University of Oklahoma [1]. The composite fuel is a mixture resulted from natural gas resolving in liquid propane, which has a relatively lower storage pressure compared with that of compressed natural gas. Here in this paper, a numerical investigation of conjugate heat transfer among convection, wall conduction and flow boiling in a double-pipe heat exchanger is presented. The heat exchanger has hot fluid flowing in the annular section and propane boiling in the inside tube. A computer program is developed to calculate the conjugate heat transfer of convection, conduction and boiling. In computing the convection and conduction, control volume method and SIMPLE algorithm are used to solve momentum equations and the energy equation of conjugate heat transfer. The contribution of this work is to combine the third kind (Neuman) of boundary condition with the boiling correlations for flow boiling in horizontal tubes in order to calculate the conjugate heat transfer of the whole problem. Two boiling correlations have been selected to give inside tube boiling heat transfer coefficient. Because the boiling coefficient depends on the wall temperature and local propane quality, so we have to solve the boiling correlation, the conduction and the convection governing equations simultaneously. The iteration method and TDMA are used to solve these coupled equations. The two boiling correlations are Chen’s (1966) correlation [2] and Kandlikar’s (1990) correlation [3]. Finally the results are compared with the experiment data. It has been found in low quality range, Kandlikar’s result is close to the experiment data. Because very few data of propane flow boiling can be found in literature, we use propane pool boiling data by Shen, Spindler and Hahne (1997) [4] to estimate parameter Ffl in Kandlikar’s correlation. The influence of simultaneously developing velocity and temperature field at entrance length in annular passage is considered and discussed in detail. The wall conduction resistance is also compared with convection and boiling resistance in the whole length of the heat exchanger. The completed computer program can be used to the design of shell and tube heat exchangers.

scholarly journals A CFD investigation and heat transfer augmentation of double pipe heat exchanger by employing helical baffles on shell and tube side

2021 ◽  
pp. 300-300
Author(s):  
Sobhanadri Anantha ◽  
Senthilkumar Gnanamani ◽  
Vivekanandan Mahendran ◽  
Venkatesh Rathinavelu ◽  
Ramkumar Rajagopal ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
The Other ◽  
Outlet Temperature ◽  
Shell Side ◽  
Shell And Tube ◽  
Double Pipe ◽  
Pipe Heat

The inclusion of baffles in a double pipe heat exchanger is becoming increasingly important as it improves the heat exchanger's performance. CFD analysis is used in this paper to investigate the performance of double pipe heat exchangers with and without helical baffles on both shell tube sides. The 3D Computation Fluid Dynamics (CFD) model was created in Solid Works, and the FloEFD software was used to analyze the conjugate Heat Transfer between the heat exchanger's tube and shell sides. Heat transfer characteristic like Outlet temperature of shell and tube are investigated along with pressure drop on shell and tube side. Based on CFD results of Double Pipe Heat exchanger with helical baffle on both shell side and tube side (Type 4) gives the better results than the other type of heat exchangers with an increased pressure drop than the others, results reveals that type 4 outlet temperature of shell side is 8% higher and on tube side it is 5.5% higher, also pressure drop on shell side is 12% higher and on tube side it is 42% higher than the other types.

scholarly journals Numerical Analysis of Heat transfer Enhancement in a double pipe heat exchanger with a holed twisted tape

2018 ◽  
Vol 144 ◽  
pp. 04012
Author(s):  
Akarsh Kumar ◽  
Ujjawal Sureka ◽  
Shiva Kumar
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Mass Flow ◽  
Transfer Rate ◽  
Twisted Tape ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Double Pipe ◽  
Pipe Heat

In the present study numerical analysis of enhancement in heat transfer characteristics in a double pipe heat exchanger is studied using a holed twisted tape.The twisted tape with a constant twist ratio is inserted in a double pipe heat exchanger. Holes of diameter 1mm, 3 mm and 5 mm were drilled at regular pitch throughout the length of the tape. Numerical modeling of a double pipe heat exchanger with the holed twisted tape was constructed considering hot fluid flowing in the inner pipe and cold fluid through the annulus.Simulation was done for varied mass flow rates of hot fluid in the turbulent condition keeping the mass flow rate of cold fluid being constant. Thermal properties like Outlet temperatures, Nusselt number, overall heat transfer coefficient, heat transfer rate and pressure drop were determined for all the cases. Results indicated that normaltwisted tape without holes performed better than the bare tube. In the tested range of mass flow rates the average Nusselt number and heat transfer rate were increased by 85% and 34% respectively. Performance of Twisted tape with holes was slightly reduced than the normal twisted tape and it deteriorated further for higher values hole diameter. Pressure drop was found to be higher for the holed twisted tape than the normal tape.

scholarly journals Numerical investigation on enhancement of heat transfer using rod inserts in single pipe heat exchanger

2019 ◽  
Vol 13 (4) ◽  
pp. 6112-6124
Author(s):  
M. A. Ashham ◽  
S. H. Raheemah ◽  
K. Salman
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Evaluation Criteria ◽  
Enhancement Of Heat Transfer ◽  
Slant Angle ◽  
Double Pipe ◽  
Single Pipe ◽  
Pitch Distance ◽  
Pipe Heat

The current study focused on statistically investigating nanofluids’ turbulent flow and rate of heat transfer in double pipe heat exchanger with rod inserts. Through the use of numerical simulation, the effects which the various kinds of nanofluids have on the enhancement of heat transfer using finite volume method (FVM) are studied. An application of homogeneous heat flux is made to the tube wall. More so, an examination of the effect of three varying slant angles of rod insert (α = 25°, 30°, 45°) was carried out at varying Reynolds number ranging from 7500 - 20000. The statistical results revealed that the coefficient of transferring heat in the tube containing rod inserts is higher than that of the smooth tube. In addition, results also showed that when rod insert are used in double pipe heat exchanger to augment the Nusselt number increases the slant angle. The max value of Nusselt number was demonstrated at the angle 45° of rod insert. Through the use of the rod inserts at (α=45°) and (S = 30mm), the coefficient of maximal skin friction was determined because of the resistance of larger flow. The maximal value of the Performance Evaluation Criteria (PEC) was mentioned in the case of min slant angle of (α = 25°) and the pitch distance of S = 30 mm.

scholarly journals Diamond-Shaped Extended Fins for Heat Transfer Enhancement in a Double-Pipe Heat Exchanger: An Innovative Design

2021 ◽  
Vol 11 (13) ◽  
pp. 5954
Author(s):  
Muhammad Ishaq ◽  
Amjad Ali ◽  
Muhammad Amjad ◽  
Khalid Saifullah Syed ◽  
Zafar Iqbal
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Adaptive Finite Element Method ◽  
Transfer Enhancement ◽  
Enhanced Heat Transfer ◽  
Frictional Loss ◽  
Special Cases ◽  
Double Pipe ◽  
Pipe Heat

Heat transfer enhancement in heat exchangers results in thermal efficiency and energy saving. In double-pipe heat exchangers (DPHEs), extended or augmented fins in the annulus of the two concentric pipes, i.e., at the outer surface of the inner pipe, are used to extend the surface of contact for enhancing heat transfer. In this article, an innovative diamond-shaped design of extended fins is proposed for DPHEs. This type of fin is considered for the first time in the design of DPHEs. The triangular-shaped and rectangular-shaped fin designs of DPHE, available in the literature, can be recovered as special cases of the proposed design. An h-adaptive finite element method is employed for the solution of the governing equations. The results are computed for various performance measures against the emerging parameters. The results dictate that the optimal configurations of the diamond-shaped fins in the DPHE for an enhanced heat transfer are recommended as follows: If around 4–6, 8–12, or 16–32 fins are to be placed in the DPHE, then the height of the fins should be 20%, 80%, or 100%, respectively, of the annulus width. If frictional loss of heat is also to be considered, then for fin-heights of 20–80% and 100% of the annulus width, the placement of 4 and 8 diamond-shaped fins, respectively, is recommended for an enhanced heat transfer. These recommendations are for the radii ratio (i.e., the ratio of the inner pipe radius to that of the outer pipe) of 0.25. The recommendations are be modified if the radii ratio is altered.

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