This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. Computational fluid dynamics (CFD) was used to analyze the effect of varying parameters like inner tube diameter, mass flow rates, and flow configuration (parallel vs. counter flow). The results show that overall heat transfer coefficients increase with increasing inner Dean number and mass flow rates. Heat transfer rates also increase with higher inner mass flow rates. Counter flow configuration provides better heat transfer than parallel flow. Increasing the inner tube size decreases the total heat transfer rate due to a reduction in annulus cross-sectional area. Measured inner Nusselt numbers agree reasonably well with existing correlations.
Parallel flow heat exchanger is analysed with CFD tool. A comparative study of the analytical and experimental data is carried out to better understand the temperature profile, surface heat flux and heat transfer co-efficient parameters of the heat exchanger
This document describes a heat exchanger design project. It provides theory on heat exchanger design including heat transfer rate calculations. It then details the CFD simulation process used to model and analyze different heat exchanger designs. This included an initial 2D model, mesh refinement studies to determine optimal mesh size, and modeling variations in pipe spacing, flow direction, and a 3D design. Results were analyzed using temperature, turbulence, and velocity contours to evaluate design performance.
Experimental Study of Heat Transfer Enhancement of Pipe-inPipe Helical Coil H...iosrjce
This document presents an experimental study of heat transfer enhancement in a pipe-in-pipe helical coil heat exchanger. Experiments were conducted with two different inner coil diameters (6mm and 8mm) under varying mass flow rates in the inner coil and annulus. The overall heat transfer coefficient and inner Nusselt number were found to increase with increasing mass flow rates. Counter-flow configuration resulted in higher heat transfer rates than parallel flow due to the larger log mean temperature difference, though overall heat transfer coefficients were similar between the two flow arrangements. Experimental results for inner Nusselt number agreed with established correlations in parallel flow but were higher in counter-flow.
CFD ANALYSIS OF DOUBLE PIPE HEAT EXCHANGEREzhil Raj s
This document summarizes a CFD analysis of a double pipe heat exchanger. It describes the geometry of the heat exchanger with an inner copper tube and outer aluminum tube. It also discusses the meshing and boundary conditions used in the CFD model. The results show that counter-current flow has a more uniform temperature distribution and higher heat transfer rate compared to parallel flow. The conclusion is that counter-current flow is more effective for heat transfer in a double pipe heat exchanger.
This document summarizes a research paper that analyzed heat transfer in an economizer using computational fluid dynamics (CFD). It discussed how fins can be added to economizer tubes to increase the heat transfer surface area between flue gases and boiler feedwater. The document reviewed previous research on economizer design optimization and failures. It described the working of CFD analysis using equations of continuity, momentum, and energy to model fluid flow. The study used the k-ε turbulence model in CFD software to analyze heat transfer with and without fins on an economizer.
Analysis of Coiled-Tube Heat Exchangers to Improve Heat Transfer Rate With Sp...IJMER
Steady heat transfer enhancement has been studied in helically coiled-tube heat exchangers. The outer side of the wall of the heat exchanger contains a helical corrugation which makes a helical rib on the inner side of the tube wall to induce additional swirling motion of fluid particles. Numerical calculations have been carried out to examine different geometrical parameters and the impact of flow and thermal boundary conditions for the heat transfer rate in laminar and transitional flow regimes. Calculated results have been compared to existing empirical formula and experimental tests to investigate the validity of the numerical results in case of common helical tube heat exchanger and additionally results of the numerical computation of corrugated straight tubes for laminar and transition flow have been validated with experimental tests available in the literature. Comparison of the flow and temperature fields in case of common helical tube and the coil with spirally corrugated wall configuration are discussed. Heat exchanger coils with helically corrugated wall configuration show 80–100% increase for the inner side heat transfer rate due to the additionally developed swirling motion while the relative pressure drop is 10–600% larger compared to the common helically coiled heat exchangers. New empirical Co-relation has been proposed for the fully developed inner side heat transfer prediction in case of helically corrugated wall configuration.
An experimental study of heat transfer in a corrugated plate heat exchangerIAEME Publication
1. The document discusses an experimental study of heat transfer in a corrugated plate heat exchanger. Experiments were conducted to analyze heat transfer characteristics for different flow arrangements of hot and cold fluids through the heat exchanger.
2. The effectiveness and exergy loss of the heat exchanger were calculated for parallel and counter flow arrangements. The average effectiveness was found to be 48% higher and exergy loss 33% lower in the counter flow arrangement compared to the parallel flow arrangement.
3. Maximum heat transfer was observed at the highest hot fluid inlet temperature of 70°C, being 5% greater in the parallel flow arrangement. However, the non-dimensional exergy loss and log mean temperature difference were both lower in the
Heat exchangers are used widely in industrial application such as chemical,
food processing, power production, refrigeration and air-conditioning
industries. Helical coiled heat exchangers are used in order to obtain a large
heat transfer per unit volume and to enhance the heat transfer rate on the inside
surface. In the present study, CFD simulations are carried out for a counter
flow tube in tube helical heat exchanger where hot water flows through the
inner tube and cold water flows through the outer tube. From the simulation
results heat transfer coefficient, pressure drop and nusselt number are
calculated. The heat transfer characteristics of the same are compared with that
of a counter flow tube in tube straight tube heat exchanger of same length
under same temperature and flow conditions. CFD simulation results showed
that the helical tube in tube heat exchanger is more effective than the straight
tube in tube heat exchanger.
This design project aims to propose a plate type heat exchanger that can meet given heat duty and find the number of plates required. Plate type heat exchanger uses metal plates to transfer heat between two fluids. Starting point of this design is to define given properties
Design and experimental analysis of pipe in pipe heat exchangerIJMER
Pipe in pipe heat exchanger are used in industrial process to recover heat between two
process fluids. The project carried out design of pipe in pipe heat exchanger having tube with fin and
without fin. The fins were taken in the form of semi-circular type arranged in altenating way with
spacing of 50mm.The fins were only provided on the inner tube for creating turbulence of cold water.
The number of fin were 18 and its height and thickness 10 and 1.6mm respectively. Experiment were
performed for heat exchanger with fins and without fins. The experiment were performed for different
flow rates of hot and cold fluid Different parameters like Overall heat transfer,Nusselt
number,Convective heat transfer coefficient,Pressure drop,friction factor were obtained and compared
for simple inner tube and finned tube.
THE EFFECT OF GEOMETRICAL PARAMETERS ON HEAT TRANSFER AND HYDRO DYNAMICAL CHA...ijmech
Compact size and high heat transfer coefficient of helical coil heat exchangers causes them to have an
important role in various industrial applications. This paper investigate numerically on the influence of
different parameters such as coil radius, coil pitch and diameter of tube on the hydrodynamic and
heat transfer characteristics of helical double tube heat exchangers using the CFD software which is
based on the principles of heat transfer, fluid mechanics and thermodynamics. The results indicated that
heat transfer augmentation occurs by increasing of the inner Dean Number, inner tube diameter, curvature
ratio and by the reduction of the pitch of heat exchanger coil. By increasing the radius of coils, the
secondary flow effects due to centrifugal forces diminishes and flow of fluid through the coils tends to flow
in a straight path and as a result, the friction coefficient decreases consequently.
The document summarizes the fabrication and testing of a heat exchanger test rig. Key points:
- The test rig was designed and built to study a counter-flow tube heat exchanger using aluminum sheets and tubes.
- Finite element analysis was performed on the rig design to analyze stresses. Water was heated to 40°C and pumped through one side while tap water entered the other side.
- Effectiveness-NTU method was used to calculate theoretical outlet temperatures which were compared to experimental readings to determine error percentages.
Design and analysis of plate heat exchanger with co2 and r134a as working fIAEME Publication
This document describes the design and analysis of a plate heat exchanger using CO2 and R134a as working fluids. The authors modeled the plate heat exchanger in Solidworks and analyzed it using computational fluid dynamics in ANSYS. They calculated the heat transfer coefficients, Nusselt number, Reynolds number, and overall heat transfer coefficient. The results from the CFD analysis matched closely with the theoretical calculations. The analysis showed a low pressure drop and the optimal design achieved a small temperature difference between the inlet and outlet of both fluids.
The document summarizes an experiment to determine heat transfer coefficients in a cross-flow plate heat exchanger under both continuous and batch operations. For continuous operation, the heat transfer rate and coefficient increased with increasing cold water flow rate. The heat transfer coefficient was highest at around 5 gallons per minute. For batch operation, the heat transfer coefficient was determined to be 7490 ± 300 W/m2K using linear regression modeling, which was higher than continuous operation. Heat losses to the environment likely contributed to the lower coefficient in continuous operation compared to batch.
This document presents an experimental study of heat transfer enhancement in a pipe-in-pipe helical coil heat exchanger. Experiments were conducted with two different inner coil diameters (6mm and 8mm) under varying mass flow rates in the inner coil and annulus. The overall heat transfer coefficient and inner Nusselt number were found to increase with increasing mass flow rates. Counter-flow configuration resulted in higher heat transfer rates than parallel flow due to the larger log mean temperature difference, though overall heat transfer coefficients were similar between the two flow arrangements. Experimental results for inner Nusselt number agreed with established correlations in parallel flow but were higher in counter-flow.
This document presents an experimental study of heat transfer enhancement in a pipe-in-pipe helical coil heat exchanger. Experiments were conducted with two different inner coil diameters (6mm and 8mm) under varying mass flow rates in the inner coil and annulus. The overall heat transfer coefficient and inner Nusselt number were found to increase with increasing mass flow rates. Counter-flow configuration resulted in higher heat transfer rates than parallel flow due to the larger log mean temperature difference, though overall heat transfer coefficients were similar between the two flow arrangements. Experimental results for inner Nusselt number agreed with established correlations in parallel flow but were higher in counter-flow.
Analysis of Heat Transfer in Spiral Plate Heat Exchanger Using Experimental a...ijsrd.com
Heat transfer is the key to several processes in industrial application. In a present days maximum efficient heat transfer equipment are in demand due to increasing energy cost. For achieving maximum heat transfer, the engineers are continuously upgrading their knowledge and skills by their past experience. Present work is a skip in the direction of demonstrating the use of the computational technique as a tool to substitute experimental techniques. For this purpose an experimental set up has been designed and developed. Analysis of heat transfer in spiral plate heat exchanger is performed and same Analysis of heat transfer in spiral plate heat exchanger can be done by commercially procurable computational fluid dynamic (CFD) using ANSYS CFX and validated based on this forecasting. Analysis has been carried out in parallel and counter flow with inward and outward direction for achieving maximum possible heat transfer. In this problem of heat transfer involved the condition where Reynolds number again and again varies as the fluid traverses inside the section of flow from inlet to exit, mass flow rate of working fluid is been modified with time. By more and more analysis and experimentation and systematic data degradation leads to the conclusion that the maximum heat transfer rates is obtained in case of the inward parallel flow configuration compared to all other counterparts, which observed to vary with small difference in each section. Furthermore, for the increase heat transfer rate in spiral plate heat exchanger is obtain by cascading system.
This document summarizes a study that investigated the thermal and hydrodynamic characteristics of a shell-helical coiled tube heat exchanger used for solar water heating. Experiments were conducted with circulating flow rates of 1.8, 3, 6, and 9 L/min on clear days in Baghdad. Results showed that heat transfer inside the helical coils increased with higher flow rates and coil diameter ratios. Collector efficiency also increased with flow rate. Pressure drop decreased as solar radiation increased, and friction factor decreased with higher flow rates. The shell-triple concentric helical coil design performed more effectively than previous shell-single coil designs.
Analysis of Double Pipe Heat Exchanger With Helical FinsIRJET Journal
This document analyzes a double pipe heat exchanger with helical fins through computational fluid dynamics (CFD). It aims to study the flow and temperature fields inside the tubes for different helical fin angles. The geometry of the double pipe heat exchanger is modeled in CATIA V5 and meshed in Hypermesh. CFD simulations are performed in ANSYS Fluent to analyze the flow and temperature distributions for fin angles of 0, 5, 10, 15, 20, and 25 degrees. The results determine that heat transfer rate and overall heat transfer coefficient increase with helical fins compared to a smooth tube, with fins providing additional surface area to enhance heat transfer.
EXPERIMENTAL STUDY ON THE ANALYSIS OF HEAT ENHANCEMENT IN CORRUGATED TWISTED ...P singh
In heat exchanger, the enthalpy is transferred between two or more fluids, at different temperatures. The major challenge in designing a heat exchanger is to make the equipment more compact and achieve a high heat transfer rate using minimum pumping power. In recent years, the high cost of energy and material has resulted in an increased effort aimed at producing more efficient heat exchange equipment. Furthermore, as a heat exchanger becomes older, the resistance to heat transfer increases owing to fouling or scaling. The heat transfer rate can be improved by introducing a disturbance in the fluid flow thereby breaking the viscous and thermal boundary layer. However, in the process pumping power may increase significantly and ultimately the pumping cost becomes high. Therefore, to achieve a desired heat transfer rate in an existing heat exchanger at an economic pumping power, several techniques have been proposed in recent years and are discussed under the classification section.
In this work, a study of transient heat transfer in double tube heat exchanger has enhanced. The inner tube of the setup was made with corrugation on both inner and outer walls by twisting the pipe from one end, which gives the more swirling motion to the fluid particles flowing over it. The flow inside the pipe was considered as turbulent, and the analysis was done experimentally and theoretically by using the ANSYS workbench. The experimental results were compared with the experimental values taken in the setup done by considering the inner tube as normal pipe. In both heat exchangers the values were taken and compared with the theoretical analysis. Temperature distribution and heat transfer rate were calculated and the details of the study have been discussed in this paper.
Study on Effect of Twisted Tape Insert Geometry in Heat Exchangerijtsrd
The heat exchanger is a device used to transfer heat from hot fluid to cold fluid. The current research reviews existing work conducted in improving performance of heat exchanger by varying geometric profile, baffling space, baffling inclination and use of helical inserts. The existing researches were conducted using both experimental and numerical techniques. The effect of operational parameters on performance of heat exchanger is also presented. Deepak Bhoi | Sudhir Singh Rajput "Study on Effect of Twisted Tape Insert Geometry in Heat Exchanger" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-2 , February 2022, URL: https://www.ijtsrd.com/papers/ijtsrd49163.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/49163/study-on-effect-of-twisted-tape-insert-geometry-in-heat-exchanger/deepak-bhoi
Heat Transfer Enhancement of Shell and Tube Heat Exchanger Using Conical Tapes.IJERA Editor
This paper provides heat transfer and friction factor data for single -phase flow in a shell and tube heat exchanger fitted with a helical tape insert. In the double concentric tube heat exchanger, hot air was passed through the inner tube while the cold water was flowed through the annulus. The influences of the helical insert on heat transfer rate and friction factor were studied for counter flow, and Nusselt numbers and friction factor obtained were compared with previous data (Dittus 1930, Petukhov 1970, Moody 1944) for axial flows in the plain tube. The flow considered is in a low Reynolds number range between 2300 and 8800. A maximum percentage gain of 165% in heat transfer rate is obtained for using the helical insert in comparison with the plain tube.
Cfd and conjugate heat transfer analysis of heat sinks with different fin geo...eSAT Journals
This document discusses a computational fluid dynamics (CFD) and conjugate heat transfer analysis of different fin geometries for heat sinks used in electronics cooling. Five fin geometries - zigzag, fluted, slanted mirror, custom pin fin, and staggered array - were analyzed under different heat loads and air velocity. The results show that the slanted mirror geometry provided the best thermal performance with the lowest thermal resistance and highest heat transfer coefficient, while maintaining a relatively low pressure drop. CFD simulations using ANSYS Fluent were conducted to analyze fluid flow, heat transfer, temperature distribution, and thermal performance of the different heat sink designs.
Biodiesel, Brake thermal efficiency, Brake specific fuel consumption Honge, J...IJMER
Steady heat transfer enhancement has been studied in helically coiled-tube heat exchangers. The outer side of the wall of the heat exchanger contains a helical corrugation which makes a helical rib on the inner side of the tube wall to induce additional swirling motion of fluid particles. Numerical calculations have been carried out to examine different geometrical parameters and the impact of flow and thermal boundary conditions for the heat transfer rate in laminar and transitional flow regimes. Calculated results have been compared to existing empirical formula and experimental tests to investigate the validity of the numerical results in case of common helical tube heat exchanger and additionally results of the numerical computation of corrugated straight tubes for laminar and transition flow have been validated with experimental tests available in the literature. Comparison of the flow and temperature fields in case of common helical tube and the coil with spirally corrugated wall configuration are discussed. Heat exchanger coils with helically corrugated wall configuration show 80–100% increase for the inner side heat transfer rate due to the additionally developed swirling motion while the relative pressure drop is 10–600% larger compared to the common helically coiled heat exchangers. New empirical Co-relation has been proposed for the fully developed inner side heat transfer prediction in case of helically corrugated wall configuration.
Comparative Study and Analysis between Helical Coil and Straight Tube Heat Ex...IJERA Editor
The purpose of this study is to determine the relative advantage of using a helically coiled heat exchanger against a straight tube heat exchanger. It is found that the heat transfer in helical circular tubes is higher as compared to Straight tube due to their shape. Helical coils offer advantageous over straight tubes due to their compactness and increased heat transfer coefficient. The increased heat transfer coefficients are a consequence of the curvature of the coil, which induces centrifugal forces to act on the moving fluid, resulting in the development of secondary flow. The curvature of the coil governs the centrifugal force while the pitch (or helix angle) influences the torsion to which the fluid is subjected to the centrifugal force results in the development of secondary flow. Due to the curvature effect, the fluid streams in the outer side of the pipe moves faster than the fluid streams in the inner side of the pipe. In current work the fluid to fluid heat exchange is taken into consideration. Most of the investigations on heat transfer coefficients are for constant wall temperature or constant heat flux. The effectiveness, overall heat transfer coefficient, effect of cold water flow rate on effectiveness of heat exchanger when hot water mass flow rate is kept constant and effect of hot water flow rate on effectiveness when cold water flow rate kept constant studied and compared for parallel flow, counter flow arrangement of Helical coil and Straight tube heat exchangers. All readings were taken at steady state condition of heat exchanger. The result shows that the heat transfer coefficient is affected by the geometry of the heat exchanger. Helical coil heat exchanger are superior in all aspect studied here.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
A Review on Study of Heat Transfer Analysis of Helical Coil Heat Exchangersijtsrd
Now a day’s a geometrically modified Helical coil heat exchangers are widely using in industrial applications like cryogenic state processes, air conditioning, thermal nuclear reactors and waste heat recovery due to their compact size and high heat transfer coefficient. Advantage of using helical coils over straight tubes is that the residence time spread is reduced, allowing helical coils to be used to reduce axial dispersion in tubular reactors. In this study, numerical investigation of the influence of geometrical parameters such as tube diameter d , coil radius R , and coil pitch p on overall heat transfer coefficient in helical double tube heat exchangers are performed using a professional CFD software FLUENT. In recent years, numerous styles were introduced for heat exchangers that apply to completely different applications sadly, their heat transfer co efficient wasnt reliable at different operational conditions. the standard of the heat changed rate wasnt optimized and there have been many deficiencies and errors in styles. The heat transfer of the copper material is enhanced in comparison with other material unfortunately thermal resistance is reduced with an increase in pressure drop thus enhancing the heat transfer on the heat exchanger. Helical architecture is often designed with a clear motive of compact size and also address heat transfer co efficient and other ancillary attributes efficiently and effectively. So the better material is suggested for an industrial heat exchanger according to the applications is Copper with the basis of simulation results. The geometry and different dimension parameter of the helical coil show that the proposed study in different material properties and different mass flow rates to heat transfer are maximum in different parameter helical coil heat exchangers. Finally, the heat transfer increase for the copper material compared to another material but with the increase in pressure drop the corresponding thermal resistance decreases which allow the improved heat transfer rate and the rate increases from Aluminum to Bronze to Copper. With the drop in temperature, the thermal resistance is reduced which enhances the heat transfer rate. The simulation results show that the copper has a high heat transfer coefficient than Aluminum and Bronze while operating in identical conditions. Due to the extensive use of helical coils in various applications, knowledge about the flow patterns and heat transfer characteristics are important. Atul Vats | Sunil Kumar Chaturvedi | Abhishek Bhandari "A Review on Study of Heat Transfer Analysis of Helical Coil Heat Exchangers" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd43650.pdf Paper URL: https://www.ijtsrd.comengineering/mechanical-engineering/43650/a-review-on-study-of-heat-transfer-analysis-of-helical-coil-heat-exchangers/atul-vats
CFD Analysis of Concentric Tube Heat Exchanger Using Twisted TapesIJARIIT
In this paper, the three dimensional CFD modeling studies on heat transfer, friction factor and thermal performance
of concentric tube heat exchanger using twisted tapes (Plain, V-cut, , Jagged V-cut) with different twist ratios (y=2.0, 4.0) are
used. Twisted tapes are used to augment the heat transfer by creating turbulence in the fluid flow. Various methods are applied
to increase thermal performance of heat transfer devices such as treated surfaces, rough surfaces, swirling flow devices, coiled
tubes, and surface tension devices. Out of these twisted tape method is used to increase the thermal performance. Twisted tape
inserts on effectiveness of heat exchanger has analyzed for different Reynolds Number. The maximum thermal performance
factor was obtained by the Jagged V-cut twisted tape (H=50) insert compare to other twisted tapes. Simultaneously the friction
factor has been analyzed
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes a study on the thermal performance of a shell and tube heat exchanger using nanofluids. Finite volume modeling was used to analyze heat transfer and flow characteristics. Various nanofluids including Ag, Al2O3, CuO, SiO2, and TiO2 suspensions in water were tested and compared to pure water. The objectives were to analyze temperature profiles, heat transfer coefficients, pressure drops, and effectiveness. Results showed nanofluids had higher overall temperatures indicating more heat transfer compared to water alone. This study analyzed the potential for nanofluids to enhance heat exchanger performance.
A Review on Comparison between Shell And Tube Heat Exchanger And Helical Coil...ijiert bestjournal
The curved shape of the tube causes the flowing fluid to experience centrifugal force. The
extent of centrifugal force experienced depends on the local axial velocity of the fluid particle
and radius of curvature of the coil. The fluid particles flowing at the core of the pipe have
higher velocities than those flowing near to the pipe wall. Thus the fluid particles flowing
close to the tube wall experience a lower centrifugal force than the fluid particles flowing in
the tube core. This causes the fluid from the core region to be pushed towards the outer wall.
This stream bifurcates at the wall and drives the fluid towards the inner wall along the tube
periphery, causing generation of counter-rotating vortices called secondary flows which
produce additional transport of the fluid over the cross section of the pipe. This additional
convective transport increases heat transfer and the pressure drop when compared to that in a
straight tube.
iaetsd Heat transfer enhancement of shell and tube heat exchanger using conic...Iaetsd Iaetsd
This document discusses heat transfer enhancement in a shell and tube heat exchanger using a conical tape insert. It provides heat transfer and friction factor data from experiments using the heat exchanger fitted with a helical tape insert. Hot air was passed through the inner tube while cold water flowed in the annulus. The helical insert increased heat transfer rate by up to 165% compared to the plain tube, with some increase in pressure drop. Equations and calculations are provided for determining heat transfer coefficients, pressure drops, and other parameters on both the shell and tube sides of the heat exchanger. Graphs of results are also presented.
Numerical Analysis of Header Configuration of the Plate-Fin Heat ExchangerIJMER
Numerical analysis of a plate fin heat exchanger accounting for the effect of fluid flow
maldistribution onthe inlet header configuration of the heat exchanger is investigated. In this analysis , it
was found that flow maldistribution has effect on the flow perpendicular to its velocity direction. The peak
velocity occurs in the central zone of the header while the velocityalong the perpendicular direction of the
inlet flow diminishes more and more. By this investigation,the results of the flow maldistribution are
presented for a plate fin heat exchangerwhich is reduced as compare to theexisting configuration of the
plate fin heat exchanger.
Similar to Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled Heat Exchangers (20)
An Examination of Effectuation Dimension as Financing Practice of Small and M...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Does Goods and Services Tax (GST) Leads to Indian Economic Development?iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Childhood Factors that influence success in later lifeiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Emotional Intelligence and Work Performance Relationship: A Study on Sales Pe...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Customer’s Acceptance of Internet Banking in Dubaiiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
A Study of Employee Satisfaction relating to Job Security & Working Hours amo...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Consumer Perspectives on Brand Preference: A Choice Based Model Approachiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Student`S Approach towards Social Network Sitesiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Broadcast Management in Nigeria: The systems approach as an imperativeiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
A Study on Retailer’s Perception on Soya Products with Special Reference to T...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
A Study Factors Influence on Organisation Citizenship Behaviour in Corporate ...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Consumers’ Behaviour on Sony Xperia: A Case Study on Bangladeshiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Design of a Balanced Scorecard on Nonprofit Organizations (Study on Yayasan P...iosrjce
1. The document describes a study that designed a balanced scorecard for a nonprofit organization called Yayasan Pembinaan dan Kesembuhan Batin (YPKB) in Malang, Indonesia.
2. The balanced scorecard translated YPKB's vision and mission into strategic objectives across four perspectives: financial, customer, internal processes, and learning and growth.
3. Key strategic objectives included donation growth, budget effectiveness, customer satisfaction, reputation, service quality, innovation, and employee development. Customers perspective had the highest weighting, suggesting a focus on public service over financial growth.
Public Sector Reforms and Outsourcing Services in Nigeria: An Empirical Evalu...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Media Innovations and its Impact on Brand awareness & Considerationiosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Customer experience in supermarkets and hypermarkets – A comparative studyiosrjce
- The document examines customer experience in supermarkets and hypermarkets in India through a survey of 418 customers.
- It finds that in supermarkets, previous experience, atmosphere, price, social environment and experience in other channels most influence customer experience, while in hypermarkets, previous experience, product assortment, social environment and experience in other channels are most influential.
- The study provides insights for retailers on key determinants of customer experience in each format to help them improve strategies and competitive positioning.
Social Media and Small Businesses: A Combinational Strategic Approach under t...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Secretarial Performance and the Gender Question (A Study of Selected Tertiary...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Implementation of Quality Management principles at Zimbabwe Open University (...iosrjce
This document discusses the implementation of quality management principles at Zimbabwe Open University's Matabeleland North Regional Centre. It begins with background information on ZOU and the importance of quality management in open and distance learning institutions. The study aimed to determine if quality management and its principles were being implemented at the regional centre. Key findings included that the centre prioritized customer focus and staff involvement. Decisions were made based on data analysis. The regional centre implemented a quality system informed by its policy documents. The document recommends ensuring staffing levels match needs and providing sufficient resources to the regional centre.
Organizational Conflicts Management In Selected Organizaions In Lagos State, ...iosrjce
IOSR Journal of Business and Management (IOSR-JBM) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Distillation basic knowledge is given in this PPT for the vapour liquid equilibrium in which we can understand the basic knowledge for the separation of the two miscible liquid which is being separation by the vapour temperature is it separated by the more related to this again the structure of structure
FINE-TUNING OF SMALL/MEDIUM LLMS FOR BUSINESS QA ON STRUCTURED DATAkevig
Enabling business users to directly query their data sources is a significant advantage for organisations.
The majority of enterprise data is housed within databases, requiring extensive procedures that involve
intermediary layers for reporting and its related customization. The concept of enabling natural language
queries, where a chatbot can interpret user questions into database queries and promptly return results,
holds promise for expediting decision-making and enhancing business responsiveness. This approach
empowers experienced users to swiftly obtain data-driven insights. The integration of Text-to-SQL and
Large Language Model (LLM) capabilities represents a solution to this challenge, offering businesses a
powerful tool for query automation. However, security concerns prevent organizations from granting direct
database access akin to platforms like OpenAI. To address this limitation, this Paper proposes developing
fine-tuned small/medium LLMs tailored to specific domains like retail and supply chain.These models
would be trained on domain-specific questions and Queries that answer these questions based on the
database table structures to ensure efficacy and security. A pilot study is undertaken to bridge this gap by
fine-tuning selected LLMs to handle business-related queries and associated database structures, focusing
on sales and supply chain domains. The research endeavours to experiment with zero-shot and fine-tuning
techniques to identify the optimal model. Notably, a new dataset is curated for fine-tuning, comprising
business-specific questions pertinent to the sales and supply chain sectors. This experimental framework
aims to evaluate the readiness of LLMs to meet the demands for business query automation within these
specific domains. The study contributes to the progression of natural language query processing and
database interaction within the realm of business intelligence applications.
Presentation slide on DESIGN AND FABRICATION OF MOBILE CONTROLLED DRAINAGE.pptxEr. Kushal Ghimire
To address increased waste dumping in drains, a low-cost drainage cleaning robot controlled via a mobile app is designed to reduce human intervention and improve automation. Connected via Bluetooth, the robot’s chain circulates, moving a mesh with a lifter to carry solid waste to a bin. This project aims to clear clogs, ensure free water flow, and transform society into a cleaner, healthier environment, reducing disease spread from direct sewage contact. It’s especially effective during heavy rains with high water and garbage flow.
WhatsApp: +852 56142185
Buy a fake University of Washington diploma. Get a fake UW diploma. Get a fake University of Washington degree. UW degree.
Skype: adolph.863
QQ/WeChat: 648998850
Email: buydocument1@gmail.com
https://www.buydocument.net
https://www.buyfastdegree.com
https://www.getadiploma9.com
https://www.diploma999.com
If we're running two pumps, why aren't we getting twice as much flow? v.17Brian Gongol
A single pump operating at a time is easy to figure out. Adding a second pump (or more) makes things a bit more complicated. That complication can deliver a whole lot of additional flow -- or it can become an exercise in futility.
I am Dr. T.D. Shashikala, an Associate Professor in the Electronics and Communication Engineering Department at University BDT College of Engineering, Davanagere, Karnataka. I have been teaching here since 1997. I prepared this manual for the VTU MTech course in Digital Communication and Networking, focusing on the Advanced Digital Signal Processing Lab (22LDN12). Based on, 1.Digital Signal Processing: Principles, Algorithms, and Applications by John G. Proakis and Dimitris G. Manolakis, Discrete-Time Signal Processing by Alan V. Oppenheim and Ronald W. Schafer, 3.Digital Signal Processing: A Practical Guide for Engineers and Scientists" by Steven W. Smith. 4.Understanding Digital Signal Processing by Richard G. Lyons. 5.Wavelet Transforms and Time-Frequency Signal Analysis" by Lokenath Debnath . 6. MathWorks (MATLAB) - MATLAB Documentation
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled Heat Exchangers
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 12, Issue 6 Ver. II (Nov. - Dec. 2015), PP 70-75
www.iosrjournals.org
DOI: 10.9790/1684-12627075 www.iosrjournals.org 70 | Page
Numerical Analysis of Heat Transfer Enhancement in Pipe-in-
Pipe Helical Coiled Heat Exchangers
Ritesh Kumar1
, Dr. Manish S. Deshmukh2
, Kamal K. Ghosh3
1,2
(Department of Mechanical Engg, JSPM’S Rajarshi Shahu College of Engg, S. P. Pune University, India)
3
(Department of Mechanical Engg, College of Military Engg, J. N. University Delhi, India)
Abstract: These paper focuses on the effect of the inside tubes at constant value of mass flow rate and variation
of annulus mass flow rate on effect of Dean Number and overall heat transfer coefficient with constant wall
temperature, CFD analysis of a helically coiled heat exchanger. Also deals with the effect of Dean Number with
respect to Reynolds Number and Nusselt Number and Overall Heat Transfer coefficient on change of coil
configuration of helically coiled tube. The particular difference in this study in comparison with the other
similar studies was the boundary conditions for the helical coils. The results indicate that with the decrease the
inner coil diameter, the overall heat transfer coefficient is increased.
Keywords: Computational Fluid Dynamics, Dean Number, Heat Transfer Correlation. , Helical Coil Heat
Exchanger, Nusselt Number.
I. INTRODUCTION
Helical coils heat exchangers are the most innovative and important types of heat exchanger, because
of compact in area and high heat transfer rate. If we are comparing to other types of heat exchanger likes shell
and tubes, plate types, etc., but in helical coil heat exchanger have compact in area and they resists high
pressure. So many researchers are research on helical coil heat exchanger, they also comparing with other types
of heat exchanger; they found helical coil heat exchangers are higher heat transfer coefficient.
Eustice was observed in curved pipe on fluid motion in 1911. Since then numerous studies have been
arises on the flow fields in curved pipe by many researchers like Dean (1927, 1928), White (1929), Horlock
(1956), Barua (1962), Austin and Seader (1973). Rustum and Soliman were observed the investigation the
performance of heat exchanger through CFD in 1990. Shah (2000) was also analyzed vertical mantle types of
heat exchanger. Heat transfer coefficients for parallel and counter flow arrangement in a double pipe helical
coil heat exchanger were determined experimentally and numerically by Timothy et. al. (2006). they have used
ANSYS CFD package PHOENICS 3.3 to carry out the numerical studies. There are so many researches
research on fluid flow over helical coil tubes heat exchanger. Fakoor, et.al, has analyzed on coil configuration of
vertical helical coil under pressure drop characteristics of Nano fluid flow, they found that helical tubes instead
of straight tubes increases the pressure drop exponentially. Pramod Purandare, et al, has carried out at different
correlations given by different researchers for helical coil. They found that the helical coil tubes are efficient for
low Re. J.S Jayakumar, et. al, also carried out an experimental study and CFD studies on fluid to fluid heat
transfer coefficient though a helical coiled tube. They found that CFD predictions values are much reasonably
with experimental results for all operating conditions. CFD analysis for turbulent flow and heat transfer on
curved pipes has done by Ivaan Di Piazza, et. al. .
After studies on CFD and literatures we found that K- model in turbulent; gave better results as
compared to the other models in the prediction of nusselt number and overall heat transfer coefficient (OHTC).
Basically a study on helical coil tubes has been carried out on heat transfer characteristics of fluid-to-fluid
flowing in pipe-in-pipe helical coil heat exchanger (PPHCHE). In helical coil have lot of variation in coil
configurations such as pitch circle diameter, coil diameter and pitch variations, curvature ratio so on. The
objective of this work is to effect of dean number and surface heat transfer coefficient at different flow
parameters at different temperature.
II. NUMERICAL SIMULATION OF PIPE-IN-PIPE HELICAL COIL HEAT EXCHANGER
1.1. Physical model
The heat exchanger was constructed from copper. The outer tube of the heat exchanger has an inner
diameter of 16 mm and a wall thickness of 1 mm. The inner tube has a 6 mm and 8 mm diameter and wall
thicknesses of 1 mm, which were constructed from standard copper tees and reducers. Coil has a radius of
curvature (measured from the center of the inner tube) of 170 mm. Small holes were drilled in the outer tube
and tapped so that set screws could be used to ensure that the inner tube was centered prior to the final
soldering of the end connections, which then held the inner tube in place.
2. Numerical Analysis of Heat Transfer Enhancement in Pipe-in-Pipe Helical Coiled Heat Exchangers
DOI: 10.9790/1684-12627075 www.iosrjournals.org 71 | Page
After soldering the set screws were removed and the holes covered so that the fluid flow in the
annulus would not be disturbed. The heat exchanger consisted of one loop. The objective of this work was to
determine the heat transfer characteristics for a pipe-in-pipe helical heat exchanger by varying the size of
the inner tube and the mass flow rates in both the annulus and in the inner tube. These objectives were
carried out for both parallel flow and counter-flow heat exchangers. A computational fluid dynamics package
(fluent 14.0) was used to predict the flow and temperature profiles in a double-pipe helical heat exchanger.
1.2. Geometry Creation and Mesh generation
A helical pipe of inner tubes diameter 6 mm and 8 mm and annulus inner diameter 16 mm with 1 mm
thickness and 6 turns was used as the geometry. A 3-D geometry is created by using ANSYS workbench and
schematic view is shown in the Fig. 2. Structured meshing method is used for meshing the geometry. It is
meshed into 507740 nodes and 485982 elements as shown in figure 3;
Figure: 2– Pipe-in-pipe helical coil tubes geometry
created in Ansys workbench
Figure: 3 – Meshing of pipe-in-pipe helical coil
tubes geometry
1.3 Fluent Setup
Numerical simulations were carried out using the Commercial CFD software package ANSYS
FLUENT 14.0. The first step taken after importing the mesh geometry into FLUENT involves checking the
mesh/grid for errors. Checking the grid assures that all zones are present and all dimensions are correct. Once
the grid was set, the solver and boundary conditions of the system were then set and cases were run and
analyzed.
1.4. Defining the Material Properties
This section of the input contains the options for the materials to be chosen. Water is passing in the
pipe-in-pipe helical coil tubes under constant wall temperature condition in the present work. Under materials
Tab in FLUENT, fluid considered is water -liquid. Solid (tube wall) material considered for analysis is copper.
The selection of material is done. Material selected is water-liquid. The properties of water- liquid is
taken as follows:
S.No. properties Value
1 Density, ρ
998.2 kg/m
3
2 Specific heat, Cp 4182 J/kg K
3 Thermal conductivity 0.6 W/m K
4 Viscosity, µ
1.003 x 10
-3
kg/m s
S.No
.
properties Value
1 Density, ρ
8978 kg/m
3
2 Specific heat, Cp 381 J/kg K
3 Thermal conductivity 387.6 W/m K
4 Viscosity, µ 0.001kg/m s
Table.1. properties of water Table.2. properties of Copper
1.5. Boundary Conditions
Water at 333K was used as the working fluid at inlet temperature of inner tubes. The numerical
studies were carried out with uniform mass flow rate at the inlet of the pipeline.
Outflow boundary condition was used at pressure-out let boundary. The wall of the helical coils was
assumed to be perfectly smooth with zero roughness height and stationary wall, no slip condition. A constant
wall temperature has define through the inlet temperature of hot water in inner pipe, 333K was used at the wall
3. Numerical Analysis of Heat Transfer Enhancement in Pipe-in-Pipe Helical Coiled Heat Exchangers
DOI: 10.9790/1684-12627075 www.iosrjournals.org 72 | Page
boundary.
Mass flow rate- Inlet Boundary: Inlet condition was taken for the pipe-in-pipe helically coil tubes
in inner pipe and the mass flow rate values are varying as 0.028 to 0.112 kg/s. Initial gauge pressure was
taken as zero Pascal. Inlet temperature of hot water was taken as 333K at all mass flow rate condition. Inlet
section of annulus was also varying the mass flow rate as 0.028 kg/s to 0.112 kg/s at same temperature of
inner section inlet temperature. Those conditions were taken parallel flow as well as counter flow.
1.6. Numerical Solution Strategy
The commercial CFD solver FLUENT 14.0 was used to perform the simulations, based on finite
volume approach to solve the governing equations with a segregated solver. The second-order upwind scheme
was used for discretization of convection terms, energy, and turbulent kinetic and turbulent dissipation
energy. This scheme ensures, in general especially for tri or tetrahedral mesh flow domain, satisfactory
accuracy, stability and convergence.
Simple algorithm was used to resolve the coupling between mass flow and pressure fields. The
convergence criterion is based on the residual value of calculated variables such as mass, velocity components,
turbulent kinetic (k), turbulent dissipation energies (ε), and energy. In the present calculations, the initial
residual values were set to 10
-6
for all variables is used. The under-relaxation factors used for the stability of
the converged solutions are set at their default values. The numerical simulation was decided as
converged when the sum of normalized residuals for each conservation equation and variables was less than
the set residual values. The total number of simulations performed was 6 4 (2 tube diameters x 4 inner
flow rates x 4 annulus flow rates x 2 flow directions). The output of the simulations included the inlet
and outlet velocities, mass flow rates and enthalpy rates, as well as velocity, pressure, and temperature fields at
30 specified cross-sections.
1.7. Executing the FLUENT Code
Each case must be initialized before the FLUENT code begins iterating towards a converged solution.
In this study, the option chosen for initialization was to compute from inlet zones. The number of iterations
ranged between 500 and 1000 depending on the case being run and how long it took to converge. Iterations
were performed with the default under- relaxation factors for all parameters.
III. RESULTS AND DISCUSSION
From fig. 4 and 5 shows that in both cases have overall heat transfer coefficients that are nearly similar,
for the same given flow rates. The ratio of the overall heat transfer coefficients (parallel flow divided by
counter-flow) for a give case range from 0.25 to 1, with the majority of the ratios slightly unity, in favor of the
counter-flow. The overall heat transfer coefficients increase with increasing inner Dean Number. However,
the significance of the increase is a function of the ratio of the mass flow rates. As can be seen in Figure 6,
the ratio of the mass flow rates has a significant effect on the overall heat transfer coefficient, raising the overall
heat transfer coefficient when the flow rate in the annulus is increased.
Fig.: 4 Overall heat transfer coefficient versus the inner
Dean number in parallel flow.
Fig.: 4. Overall heat transfer coefficient versus the
inner Dean number in Counter flow.
From above figure, it can be shown that increasing the inner Dean number has a greater effect on the
overall heat transfer coefficients when the inner flow rate is higher. When flow rates are increased, the overall
heat transfer rate will also increase, but the significance of the increase is highly dependent on the annulus
flow rates. There is a difference between the overall heat transfer coefficients for the two different tube
4. Numerical Analysis of Heat Transfer Enhancement in Pipe-in-Pipe Helical Coiled Heat Exchangers
DOI: 10.9790/1684-12627075 www.iosrjournals.org 73 | Page
sizes. There are a couple of reasons why this difference has been observed.
Fig. - 6 Heat transfer rate verses Inner mass flow rate in
parallel Flow
Fig.-7 Heat transfer rate verses Inner mass flow rate
in Counter Flow
Fig.- 8 Figure: Heat transfer rate verses Inner mass
flow rate
Fig.-9 Percentage increases in heat transfer when
comparing parallel and counter flow verses inner
Dean Number
Figure 8 and figure 9 shows the relationship between the heat transfer rate and the mass flow rate in
the inner tube for the case of parallel flow and counter flow. The data points are also indicated into the four
different mass flow ratios and the two different tube sizes. This allows for a more intuitive understanding
of the effectiveness of the different mass flow ratios and tube sizes on the heat transfer rate than the plots of
heat transfer coefficients versus the inner Dean number. For any given inner mass flow rate, there are eight
different values, corresponding to the different combinations of mass flow rates and tube sizes.
Increasing the tube size resulted in a decrease in the total heat transfer rate. Furthermore, increasing the tube
size decreases the cross-sectional area for fluid flow in the annulus, resulting in an increased flow velocity,
opposite to that found in the inner tube.
1.2. Inner Nusselt numbers
The inner Nusselt numbers are presented in Figure 10 and figure 11. These values are the average
inner Nusselt number at each Dean number (average of parallel flow and counter-flow values). The data
are compared to the correlation of Manlapaz- Churchill correlation (1981). Manlapaz- Churchill correlation
(1981) developed their correlation based on numerical data with a constant wall temperature. In order to
calculate these correlations, Prandtl numbers were essential for the flow. These were evaluated using the
arithmetic mean temperature of the corresponding fluid (average of inlet and outlet temperatures). Decent
agreement between the experimental and literature values indicate that the use of existing correlations for
heat transfer in helical coils could be used to estimate inner heat transfer rate in a pipe-in-pipe helical
coil heat exchanger.
5. Numerical Analysis of Heat Transfer Enhancement in Pipe-in-Pipe Helical Coiled Heat Exchangers
DOI: 10.9790/1684-12627075 www.iosrjournals.org 74 | Page
Fig.-10 Inner Nusselt Number verses Inner Dean
Number of Small coil
Fig.-11 Inner Nusselt Number verses Inner Dean
Number of Large coil
IV. CONCLUSION
A computational fluid dynamics package (Fluent-14.0) was used to numerically investigation to the
heat transfer characteristics of a pipe-in-pipe helical heat exchanger for both parallel flow and counter-flow.
Validation runs were performed with the boundary conditions of constant wall temperature. After the analysis of
pipe-in-pipe helical coil heat exchanger; some conclusion are found:
1. Overall heat transfer coefficients were calculated for inner Dean Numbers. The results show an increasing
overall heat transfer coefficients as the inner Dean number is increased; however, flow conditions in the
annulus had a stronger influence on the overall heat transfer coefficient.
2. Overall heat transfer coefficient of the small coil diameter is higher in both flow (parallel and counter
flow) conditions with high velocity.
3. Increasing the tube size result is to be found decrease in the total heat transfer rate.
4. The inner Nusselt numbers are shows that the slightly difference between the parallel flow condition of the
large coil but in small coil condition the value is very high.
5. All the studies have found in counter flow configuration is much better then in parallel flow configuration.
6. Further work needs to be done to quantify this effect on coil configurations.
REFERENCES
Journal Papers:
[1] Rahul Kharat, Nitin Bhardwaj, R.S. Jha ”Development of heat transfer coefficient correlation for concentric helical coil heat
exchanger”International Journal of Thermal Sciences 48 (2009) 2300–2308.
[2] Kapil Dev, Kuldeep Singh Pal, Suhail A. Siddiqui , “An Empirical Study of Helical Coil Heat Exchanger Used in Liquid
Evaporization and Droplet Disengagement for a Laminar Fluid Flow” International Journal of Engineering Sciences & Research
Technology April, 2014, ISSN: 2277-9655.
[3] Pablo Coronel, K.P. Sandeep “Heat Transfer Coefficient in Helical Heat Exchangers under Turbulent Flow Conditions”
International Journal of Food Engineering, Volume 4, Issue 1 2008 Article 4.
[4] Aly Wael I.A., Numerical study on turbulent heat transfer and pressure drop of nanofluid in coiled tube-in-tube heat
exchangers, Energy Conversion and Management, vol.-79 (2014)
[5] Eiamsa-ard Smith., Promvonge Pongjet., Enhancement of heat transfer in a tube with regularly- spaced helical tape swirl
generators, Solar Energy, vol.-78 (2005) 483–494.
[6] Eiamsa-ard Smith., Promvonge Pongjet., Heat transfer characteristics in a tube fitted with helical screw-tape with/without
core-rod inserts,International Communications in Heat and Mass Transfer, vol.-34 (2007) 176–185.
[7] Ferng Y.M., Lin W.C., Chieng C.C., Numerically investigated effects of different Dean number and pitch size on flow and heat
transfer characteristics in a helically coil-tube heat exchanger, Applied Thermal Engineering, vol.-36 (2012) 378-385.
[8] Genic Srbislav B., Jacimovic Branislav M., Jaric Marko S., Budimir Nikola J., Dobrnjac Mirko M., Research on the shell-side
thermal performances of heat exchangers with helical tube coils, International Journal of Heat and Mass Transfer, vol.-55 (2012)
4295–4300.
[9] Ghorbani Nasser., Taherian Hessam., Gorji Mofid., Mirgolbabaei Hessam., An experimental study of thermal performance of
shell-and-coil heat exchangers, International Communications in Heat and Mass Transfer, vol.-37 (2010) 775–781.
[10] Huminic Gabriela., Huminic Angel., Heat transfer characteristics in double tube helical heat exchangers using nanofluids,
International Journal of Heat and Mass Transfer, vol.-54 (2011).
[11] Jahanmir Gh.S., Farhadi F., Twisted bundle heat exchangers performance evaluation by CFD, International Communications
in Heat and Mass Transfer, vol.-39 (2012) 1654–1660.
[12] Timothy J. Rennie, Vijaya G.S. Raghavan, “Numerically studies of a double-pipe helical heat exchanger”, IOSR,January 2005.
[13] Pramod S. Purandarea, Mandar M. Leleb, Rajkumar Gupta “ Parametric analysis of helical coil heat exchanger”. International
Journal of Engineering Research & Technology (IJERT),ISSN: 2278-0181,Vol. 1 Issue 8, October – 2012.
[14] B. Chinna Ankanna, B. Sidda Reddy, “ Performance analysis of fabricated helical coil heat exchanger”. International Journal of
Engineering Research ISSN:2319-6890)(online),2347-5013 Volume No.3 Issue No: Special 1, pp: 33-39 22nd March 2014.
[15] Ashok Reddy K, Bhagvanth Rao M. Ram Reddy. “ Effect of dean number on heating transfer coefficients in an flat bottom agitated
vessel. IOSR Journal of Engineering May. 2012, Vol. 2(5) pp: 945-951.
6. Numerical Analysis of Heat Transfer Enhancement in Pipe-in-Pipe Helical Coiled Heat Exchangers
DOI: 10.9790/1684-12627075 www.iosrjournals.org 75 | Page
[16] Neeraj Kumar Nagayach, Dr.Alka Bani Agrawal. “ Review of heat transfer augmentation in circular and non circular tube”.
International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5,
September- October 2012, pp.796-802
[17] H. S. Patel, R.N.Makadia, “ A review on performance evaluation and cfd analysis of double pipe heat exchanger”. PARIPEX -
INDIAN JOURNAL OF RESEARCH. Volume : 2 | Issue : 4 | April 2013 ISSN - 2250-1991.
[18] Mofid Gorji Bandpy, Hasan Sajjadi “An Experimental Study of the Effect of Coil Step on Heat Transfer Coefficient in Shell- Side of
Shell-and-Coil Heat Exchanger”. World Academy of Science, Engineering and Technology Vol:4 2010-11-24, International Science
Index Vol:4, No:11, 2010 waset.org/Publication/11538.
[19] Alok Vyas, Mr. Prashant Sharma, “An Experimental Analysis Study to Improve Performance of Tubular Heat Exchangers”. Journal
of Engineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1804-1809.
[20] S. Laohlertdecha,A.S. Dalkilic and S. Wongwises, “A Review on the heat transfer equipments and pressure-drop characteristics of
various enhanced tubes” International Journal of Air-Conditioning and Refrigeration Vol. 20, No. 4 (2012) 1230003 (20 pages) .
[21] Pardeep Kumar,Vijay Kumar,Sunil Nain“ Experimental Study on Heat Enhancement of Helix-changer with Grooved Tubes”.
International Journal of Latest Trends in Engineering and Technology (IJLTET) Vol. 3 Issue 4 March 2014 ISSN: 2278-621X.
[22] N. D. Shirgire, P. Vishwanath Kumar. “Review on Comparative Study between Helical Coil and Straight Tube Heat Exchanger”.
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 8, Issue 2 (Jul.
- Aug. 2013),
Books:
[23] Fundamentals of Heat and Mass Transfer, Incropera, Dewitt, John Wiley and sons.
[24] Heat transfer - A basic approach, M.N. Ozisik, Mc Graw Hill Int.
[25] Heat transfer, J.P. Holman, Mc Graw Hill
[26] Fundamentals of Heat Exchanger Design -Ramesh K. Shah, Dusan P. Sekulic,Wiley-India
[27] Process Heat Transfer – Donald Q. Kern, Tata McGraw-Hill
[28] T. J. Chung, Computational Fluid Dynamics, Cambridge University Press.
[29] Anderson,D.A., Tannehill,J.C. and Pletcher,R.H., Computational Fluid Dynamics and Heat Transfer, McGraw Hill, 1984.
[30] Versteeg, H. K. and Malalasekara, W. (2008). Introduction to Computational Fluid Dynamics: The Finite Volume Method. Second
Edition (Indian Reprint) Pearson Education.
[31] Pradip Niyogi, S.K. Chakraborty, M.K. Laha, Introduction to Computational Fluid.