International Journal of Engineering Inventions (IJEI) provides a multidisciplinary passage for researchers, managers, professionals, practitioners and students around the globe to publish high quality, peer-reviewed articles on all theoretical and empirical aspects of Engineering and Science.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Comparison of Shell and Tube Heat Exchanger using Theoretical Methods, HTRI, ...IJERA Editor
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The aim of this article is to compare the design of Shell and Tube Heat Exchanger with baffles. Baffles used in
shell and tube heat exchanger improve heat transfer and also result in increased pressure drop. Shell and tube
heat exchanger with single segmental baffles was designed with same input parameters using 1) Kernâs
theoretical method; 2) ASPEN simulation software and 3) HTRI simulation software 4) SOLIDWORKS
simulation software. Shell side pressure drop and heat transfer coefficient are predicted. The results of all the
three methods indicated the results in a close range. The proven theoretical methods are in good agreement with
the simulation results
Numerical Analysis of Fin Side Turbulent Flow for Round and Flat Tube Heat E...IJMER
Â
Numerical three dimensional simulation of turbulent flow in round and flat tube fin heat exchangers having two rows of staggered arrangement has been carried out to investigate fluid flow and heat transfer characteristics using ANSYS Fluent 14ÂŽ software. HYPERMESH10ÂŽ Software has been
used for the creation of models as well for meshing. The cases have been simulated for different fin side Reynolds number in turbulent regime to observe the effect of various parameters like fin pitch, tube pitch and fin temperature on Colburn j factor and Friction factor f for both round and flat tubes. Fin side flow has been simulated using various steady flow models in the software for same velocity range. As simulation using k-Îľ model resulted in close agreement with that of experimental in turbulent regime, it is considered for further analysis. The performance of round tubes is compared with that of flat tubes with same flow area and geometrical parameters. For both round and flat tube domains with all the geometrical configurations simulated in this work Colburn j factor varied inversely with the inlet air velocity. The heat transfer is more with the higher fin spacing for both round and flat tubes following the above said trend. On the other hand, the pressure drop across the tubes is more with the lesser fin spacing
in contrast to the heat transfer. Due to lesser turbulent intensity in flat tubes, they exhibit slightly lesser
Colburn j factor and considerably lesser pressure drop compared to round tubes. Although flat tubes
exhibit slightly lesser Colburn j factor, due to larger exposed tube area increase in the air temperature in
the fin side is comparable with that of round tubes. Higher fin temperatures result with lesser Colburn j factor and higher pressure drop across the tubes although the fin temperature affects the pressure drop to lesser extent.
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.
Experimental Study of Heat Transfer Enhancement of Pipe-inPipe Helical Coil H...iosrjce
Â
Heat transfer enhancement in pipe in pipe helical coils has been research by many researchers.
While the many literatures available on heat transfer characteristics of helical coil heat exchangers. There is
very few published on validate experimental results through Computational Fluid Dynamics. This paper focuses
on experimental investigation of fluid-to-fluid heat transfer enhancement of pipe-in-pipe helical coil tubes. The
methodology of experimental analysis of a helical tubes heat exchanger, the effect of the inside tubes at constant
value of mass flow rate in Dean Number and also established the surface heat transfer coefficient. Heat transfer
characteristics inside pipe-in-pipe helical coils for various boundary conditions, that the specification of a
constant temperature at hot water inlet, constant mass flow rate. Hence, the pipe-in-pipe heat exchanger is
considering different mass flow rate inside and annulus. The fabrication of experimental setup is estimate the
heat transfer enhancement in inside helical coil tubes
FLUID FLOW ANALYSIS IN AIR DUCT FLOW WITH AND WITHOUT INTERNAL THREADS USING ...IAEME Publication
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Computational heat transfer flow modeling is one of the great challenges in the classical sciences. As with most problems in engineering, the interest in the heat transfer augmentation is increasing due to its extreme importance in various industrial applications. This paper deals with the analysis of heat transfer for fluid flowing through the pipe with and without internal threads using CFD. Using CFD codes for modeling the heat and fluid flow is an efficient tool for predicting equipment performance. CFD offers a convenient means to study the detailed flows and heat exchange processes, which take place inside the tube. Simulations were carried out using commercial CFD software ANSYS Fluent version 14.5. Friction factor and Nusselt number for air flowing through the specified tube (internal diameter = 0.005 m, length = 0.1 m) were obtained first for the plain tube and then for the tube with internal threads with pitch 5mm in the Reynolds number range of 2000 to 5000. Finally results will be compared to available experimental and analytical calculations. The data obtained by simulation are matching with the literature value for a plain tube with the discrepancy of less than plus or minus 5% for Nusselt number and for the friction factor.
Enhanced heat transfer for the tube with internal threads has been observed. Heat flux is more uniform all along the tube and decreases uniformly towards the center.
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.
Comparison of Shell and Tube Heat Exchanger using Theoretical Methods, HTRI, ...IJERA Editor
Â
The aim of this article is to compare the design of Shell and Tube Heat Exchanger with baffles. Baffles used in
shell and tube heat exchanger improve heat transfer and also result in increased pressure drop. Shell and tube
heat exchanger with single segmental baffles was designed with same input parameters using 1) Kernâs
theoretical method; 2) ASPEN simulation software and 3) HTRI simulation software 4) SOLIDWORKS
simulation software. Shell side pressure drop and heat transfer coefficient are predicted. The results of all the
three methods indicated the results in a close range. The proven theoretical methods are in good agreement with
the simulation results
Numerical Analysis of Fin Side Turbulent Flow for Round and Flat Tube Heat E...IJMER
Â
Numerical three dimensional simulation of turbulent flow in round and flat tube fin heat exchangers having two rows of staggered arrangement has been carried out to investigate fluid flow and heat transfer characteristics using ANSYS Fluent 14ÂŽ software. HYPERMESH10ÂŽ Software has been
used for the creation of models as well for meshing. The cases have been simulated for different fin side Reynolds number in turbulent regime to observe the effect of various parameters like fin pitch, tube pitch and fin temperature on Colburn j factor and Friction factor f for both round and flat tubes. Fin side flow has been simulated using various steady flow models in the software for same velocity range. As simulation using k-Îľ model resulted in close agreement with that of experimental in turbulent regime, it is considered for further analysis. The performance of round tubes is compared with that of flat tubes with same flow area and geometrical parameters. For both round and flat tube domains with all the geometrical configurations simulated in this work Colburn j factor varied inversely with the inlet air velocity. The heat transfer is more with the higher fin spacing for both round and flat tubes following the above said trend. On the other hand, the pressure drop across the tubes is more with the lesser fin spacing
in contrast to the heat transfer. Due to lesser turbulent intensity in flat tubes, they exhibit slightly lesser
Colburn j factor and considerably lesser pressure drop compared to round tubes. Although flat tubes
exhibit slightly lesser Colburn j factor, due to larger exposed tube area increase in the air temperature in
the fin side is comparable with that of round tubes. Higher fin temperatures result with lesser Colburn j factor and higher pressure drop across the tubes although the fin temperature affects the pressure drop to lesser extent.
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.
Experimental Study of Heat Transfer Enhancement of Pipe-inPipe Helical Coil H...iosrjce
Â
Heat transfer enhancement in pipe in pipe helical coils has been research by many researchers.
While the many literatures available on heat transfer characteristics of helical coil heat exchangers. There is
very few published on validate experimental results through Computational Fluid Dynamics. This paper focuses
on experimental investigation of fluid-to-fluid heat transfer enhancement of pipe-in-pipe helical coil tubes. The
methodology of experimental analysis of a helical tubes heat exchanger, the effect of the inside tubes at constant
value of mass flow rate in Dean Number and also established the surface heat transfer coefficient. Heat transfer
characteristics inside pipe-in-pipe helical coils for various boundary conditions, that the specification of a
constant temperature at hot water inlet, constant mass flow rate. Hence, the pipe-in-pipe heat exchanger is
considering different mass flow rate inside and annulus. The fabrication of experimental setup is estimate the
heat transfer enhancement in inside helical coil tubes
FLUID FLOW ANALYSIS IN AIR DUCT FLOW WITH AND WITHOUT INTERNAL THREADS USING ...IAEME Publication
Â
Computational heat transfer flow modeling is one of the great challenges in the classical sciences. As with most problems in engineering, the interest in the heat transfer augmentation is increasing due to its extreme importance in various industrial applications. This paper deals with the analysis of heat transfer for fluid flowing through the pipe with and without internal threads using CFD. Using CFD codes for modeling the heat and fluid flow is an efficient tool for predicting equipment performance. CFD offers a convenient means to study the detailed flows and heat exchange processes, which take place inside the tube. Simulations were carried out using commercial CFD software ANSYS Fluent version 14.5. Friction factor and Nusselt number for air flowing through the specified tube (internal diameter = 0.005 m, length = 0.1 m) were obtained first for the plain tube and then for the tube with internal threads with pitch 5mm in the Reynolds number range of 2000 to 5000. Finally results will be compared to available experimental and analytical calculations. The data obtained by simulation are matching with the literature value for a plain tube with the discrepancy of less than plus or minus 5% for Nusselt number and for the friction factor.
Enhanced heat transfer for the tube with internal threads has been observed. Heat flux is more uniform all along the tube and decreases uniformly towards the center.
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.
Numerical Analysis of Header Configuration of the Plate-Fin Heat ExchangerIJMER
Â
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.
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
Â
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
CFD Analysis of Concentric Tube Heat Exchanger Using Twisted TapesIJARIIT
Â
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
HEAT TRANSFER AUGMENTATION IN STEEL QUENCHING BY SPRAY IMPINGEMENT COOLING ME...BIBHUTI BHUSAN SAMANTARAY
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The present article discusses the experimental results on heat transfer characteristics of spray impingement cooling of a stationary steel plate. The eexperimental setup consisted of an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm, spray setup, water supply and air supply unit. The effects of various controlling parameters such as air-water pressures, water flow rate, nozzle tip to target distance and impingement density were determined and analysed. The cooling rates were computed from the time dependent temperature history and used to analyse the parametric effects. The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods available in the open literature.
Comparative Study of ECONOMISER Using the CFD Analysis IJMER
Â
This paper presents a simulation of the economizer zone, which allowsstudying the flow
patterns developed in the fluid, while it flows along the length of the economizer. The past failure
details revelsthat erosion is more in U-bend areas of Economizer Unit because of increase in flue gas
velocity near these bends. But it isobserved that the velocity of flue gases surprisingly increases near
the lower bends as compared to upper ones. The model issolved using conventional CFD techniques by
FLUENT software. In which the individual tubes are treated as sub-gridfeatures. A geometrical model
is used to describe the multiplicity of heat-exchanging structures and the interconnectionsamong them.
The Computational Fluid Dynamics (CFD) approach is utilised for the creation of a three-dimensional
modelof the economizer coil of single column tube. With equilibrium assumption applied for
description of the system chemistry. The flue gastemperature, pressure and velocity field of fluid flow
within an economizer tube using the actual bounda
A Review on Study of Heat Transfer Analysis of Helical Coil Heat Exchangersijtsrd
Â
Now a dayâs 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
THE STUDY OF THE EFFECTS OF RADIATION AND BLOWING FROM THE WALL OF A VERTICAL...ijmech
Â
This article investigates the effects of radiation and blowing from a wall on a turbulent heat transfer in vertical channels with asymmetrical heating. The equations involved were numerically solved with three turbulent models including SpalartAllmaras, R-N-G k-
with"Standard Wall Function" wall nearby model, R-N-G k- with "Enhanced Wall Treatment" wall nearby model and "Ray Tracing" radiation techniques. The results were compares with experimental data and appropriate methods were selected for turbulent modeling. The problem
of Rayleigh number, Reynolds, radiation parameters and Prandtl were solved and the effects of these parameters on the flow lines, lines of constant temperature, radiation, convection, heat transfer caused by blowing and the total heat transfer were determined.
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.
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
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.
Study on Effect of Twisted Tape Insert Geometry in Heat Exchangerijtsrd
Â
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
Numerical Analysis of Header Configuration of the Plate-Fin Heat ExchangerIJMER
Â
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.
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
Â
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
CFD Analysis of Concentric Tube Heat Exchanger Using Twisted TapesIJARIIT
Â
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
HEAT TRANSFER AUGMENTATION IN STEEL QUENCHING BY SPRAY IMPINGEMENT COOLING ME...BIBHUTI BHUSAN SAMANTARAY
Â
The present article discusses the experimental results on heat transfer characteristics of spray impingement cooling of a stationary steel plate. The eexperimental setup consisted of an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm, spray setup, water supply and air supply unit. The effects of various controlling parameters such as air-water pressures, water flow rate, nozzle tip to target distance and impingement density were determined and analysed. The cooling rates were computed from the time dependent temperature history and used to analyse the parametric effects. The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods available in the open literature.
Comparative Study of ECONOMISER Using the CFD Analysis IJMER
Â
This paper presents a simulation of the economizer zone, which allowsstudying the flow
patterns developed in the fluid, while it flows along the length of the economizer. The past failure
details revelsthat erosion is more in U-bend areas of Economizer Unit because of increase in flue gas
velocity near these bends. But it isobserved that the velocity of flue gases surprisingly increases near
the lower bends as compared to upper ones. The model issolved using conventional CFD techniques by
FLUENT software. In which the individual tubes are treated as sub-gridfeatures. A geometrical model
is used to describe the multiplicity of heat-exchanging structures and the interconnectionsamong them.
The Computational Fluid Dynamics (CFD) approach is utilised for the creation of a three-dimensional
modelof the economizer coil of single column tube. With equilibrium assumption applied for
description of the system chemistry. The flue gastemperature, pressure and velocity field of fluid flow
within an economizer tube using the actual bounda
A Review on Study of Heat Transfer Analysis of Helical Coil Heat Exchangersijtsrd
Â
Now a dayâs 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
THE STUDY OF THE EFFECTS OF RADIATION AND BLOWING FROM THE WALL OF A VERTICAL...ijmech
Â
This article investigates the effects of radiation and blowing from a wall on a turbulent heat transfer in vertical channels with asymmetrical heating. The equations involved were numerically solved with three turbulent models including SpalartAllmaras, R-N-G k-
with"Standard Wall Function" wall nearby model, R-N-G k- with "Enhanced Wall Treatment" wall nearby model and "Ray Tracing" radiation techniques. The results were compares with experimental data and appropriate methods were selected for turbulent modeling. The problem
of Rayleigh number, Reynolds, radiation parameters and Prandtl were solved and the effects of these parameters on the flow lines, lines of constant temperature, radiation, convection, heat transfer caused by blowing and the total heat transfer were determined.
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.
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
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.
Study on Effect of Twisted Tape Insert Geometry in Heat Exchangerijtsrd
Â
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
Ijri te-03-011 performance testing of vortex tubes with variable parametersIjripublishers Ijri
Â
Conventional refrigeration system is a type of refrigeration systems which are costly; noisy, harmful gases released from a machine based on application of this type of system and it is required more maintenance. So, we need to go for unconventional refrigeration systems like vortex tube refrigeration system, which produce less vibrations and which require less maintenance and which are noiseless. It is required for our mechanical engineers to look for enhancing the performance of such vortex tubes. So as a part of my project work, I have chosen various sizes of vortex tubes and test their performances for finding out optimum performance. We will be testing the performance of vortex tubes with different âl/dâ ratios and different cold fractions, with different pressures and different nozzle sizes.
CFD Analysis of Plate Fin Tube Heat Exchanger for Various Fin InclinationsIJERA Editor
Â
ANSYS Fluent software is used for three dimensional CFD simulations to investigate heat transfer and fluid flow characteristics of six different fin angles with plain fin tube heat exchangers. The numerical simulation of the fin tube heat exchanger was performed by using a three dimensional numerical computation technique. Geometry of model is created and meshed by using ANSYS Workbench software. To solve the equation for the fluid flow and heat transfer analysis ANSYS FLUENT was used in the fin-tube heat exchanger. The fluid flow and heat transfer are simulated and result compared for both laminar and turbulent flow models k-epsilon and SST k-omega, with steady state solvers to calculate heat transfer, flow velocity and temperature fields of variable inclined fin angles (Ć = 00,100 , 200, 300, 400,500). Model is validate by comparing the simulated value of velocity, temperature and colburn factor with experimental and numerical results investigated by WANG [1] and GHORI KIRAR [10]. Reasonable agreement is found between the simulations and other results, and the ANSYS Fluent software is sufficient for simulating the flow fields in tube fin heat exchanger.
Numerical Investigation of Air Cooled Condensers using Different Refrigerantsijtsrd
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Selection of Capillary Tube for Refrigeration System
1. International Journal of Engineering Inventions
e-ISSN: 2278-7461, p-ISSN: 2319-6491
Volume 2, Issue 12 (August 2013) PP: 52-55
www.ijeijournal.com Page | 52
Selection of Capillary Tube for Refrigeration System
A. S. Patil1
, Prof. A. M. Patil2
Associate Professor & vice Principal PVPIT, Budhgaon Sangli
Abstract: Proper selection of capillary tube it is essential to study the effect of capillary tube geometry on the
performance of refrigeration systems. The literature review is focused on the influence of geometrical
parameters like tube length, diameter, coil pitch, number of twist and twisted angle on pressure drop and
coefficient of performance (COP) of the system. These parameters can be optimized using mathematical
modeling, experimental methods and maintaining proper pressure between condenser and evaporator.
Keywords: Capillary Tube, Refrigeration system, Selection, Tube diameter.
I. INTRODUCTION
A capillary tube is a common expansion device used in small sized refrigeration and air conditioning
systems. A capillary tube is a constant area expansion device used in a vapor compression refrigeration system
located between the condenser and evaporator and whose function is to reduce the high pressure in the
condenser to low pressure in the evaporator. Capillary tubes are extensively used where load is fairly constant
due to its advantage such as cheap, reliable, simple to install, zero maintenance and requirement of a low
starting torque to run the compressor.
II. LITERATURE REVIEW
Several literature sources are focused on the size of capillary tubes used in refrigeration and Air
conditioning systems. The appropriate size of capillary tube can be calculated from the refrigerant effect,
coefficient of performance (COP) and others. The effects of various geometries of capillary tubes have been
investigated by many researchers. Since the capillary tube is to be folded in order to reduce the required space.
Hence the following literature is focused on the effect of capillary tube geometry on the performance of
refrigeration system.
Amr O. Elsayed (2006) studied Performance characteristics of twisted capillary tube have been
presented and compared with the original capillary tube of window type air conditioner using R-22 as a
refrigerant. Three twisted capillary tubes with the same inner diameter and length, as the original capillary tube,
have been tested experimentally. The effect of twist angle and the number of twisted points on the refrigeration
cycle performance have been investigated and discussed. From the above conclusions it can be deduced that the
control of the capillary tube length can be done by selecting the suitable number of twisted points with correct
choice for the twist angle to obtain the required pressure drop across the capillary tube. Future experimental
investigations are needed to correlate the capillary tube length and diameter with different twist angles at
various numbers of twisted points for alternative refrigerants in different refrigeration cycles.
Hirendra Kumar Paliwal and Keshav Kant (2006) developed a flow model to design and study the
performance of helical capillary tubes and to mathematically simulate a situation closer to that prevailing in
practice. Homogeneous flow of two phase fluid is assumed through the adiabatic capillary tube. The model
includes the second law restrictions. The effect variation of different parameters like condenser and evaporator
pressures, refrigerant flow rate, degree of sub cooling, tube diameter, internal roughness of the tube, pitch and
the diameter of the helix on the length of the capillary tube are included in the model. Theoretically predicted
lengths of helical capillary tube for R-134a are compared with the length of the capillary tube needed under
similar experimental conditions and majority of predictions are found to be within 10% of the experimental
value.
S. M. Sami et al. (2001) experimentally investigated capillary tube behavior using various new
alternatives under different geometrical parameters. Capillary geometrical parameters will include length,
diameter, as well as entrance conditions. The results clearly showed that the pressure drop across the capillary
tube is significantly influenced by the diameter of the capillary tube, inlet conditions to the capillary and
refrigerant type. The data demonstrated that the capillary pressure drop decreases with the increase of the
capillary diameter and that alternatives in general experience higher pressure drop than that of R-22.
Chunlu Zhang and Guoliang Ding (2004) developed two kinds of approximate analytic solutions of
adiabatic capillary tube. One is the explicit function of capillary tube length. Another is the explicit function of
refrigerant mass flow rate. In these solutions, the choked flow condition is taken into account without iterative
2. Selection of Capillary Tube for Refrigeration System
www.ijeijournal.com Page | 53
calculations. The approximate predictions are found to agree reasonably well with experimental data in open
literatures.
Akkarat Poolkrajang et al. (2009) evaluate the optimization of a capillary tube in a split type air
conditioning system and to determine the coefficient of performance (COP) of the system. The optimization was
determined by mathematical calculation to evaluate COP of a split-type air conditioning system within 5
different sizes of capillary tube. Following this, the experimental equipment was designed and constructed to
verify the COP data obtained from the calculation. The results found that from the theoretical analysis and
experiment, the COP was changing in a direction contrary to the diameter of the capillary tube. When the
capillary tube diameter is smaller, COP values tend to be higher.
Akash Deep Singh (2009) developed a mathematical model of diabatic capillary tube. The
mathematical model has been developed by using equations of conservation of mass, momentum and energy for
predicting the length of diabatic capillary tube. Moody (1944) correlation is used to calculate the friction factor.
McAdams et al. (1942) viscosity correlation has been used to evaluate the two phase viscosity of the refrigerant.
Input parameters have been taken from the data of Mendoca et al. (1998). Further, a geometric model is
developed in Pro-E and the mesh is created in Ansys ICEM CFD and analysis is carried out in Ansys CFX
which has three modules CFX-Pre, Solver and CFX-Post.
M.A. Akintunde (2008) investigated the effects of various geometries of capillary tubes based on the
coil diameters and lengths alone, with no particular attention placed on the effect of coil pitch. This paper
examined the effects of pitches of both helical and serpentine coiled capillary tubes on the performance of a
vapor compression refrigeration system. Several capillary tubes of equal lengths (2.03 m) and varying pitches,
coiled diameters and serpentine heights were used. Both inlet and outlet pressure and temperature of the test
section (capillary tube) were measured and used to estimate the COP of the system. In the case of helical coiled
geometries, the pitch has no significant effect on the system performance. In the case of serpentine geometries,
both pitch and height affects the system performance. Performance improves with both increase in the pitch and
the height. Correlations were proposed to describe relationships between straight and coiled capillary tube and
between helical coiled and serpentine coiled capillary tubes. The COP obtained was 0.9841 for mass flow rates
of helical and serpentine with straight tubes, 0.9864 and 0.9996 for mass flow rates of serpentine and helical
coiled tube respectively. This study investigated the performance of capillary tube geometries having R-134a as
the working fluid
Corberan et al. (2008) found a numerical method used to calculate mass flow rate in a capillary tube.
The proposed method solves the conservation laws (continuity, momentum and energy) in 1D mesh. An
iterative process is performed for a guessed value of the mass flow rate and it is followed until critical flow
conditions are obtained. The resulting length is compared with the capillary tube length and a new guess of the
mass flow rate is imposed. The iteration is repeated until convergence. In two phase flow, a separated flow
model is assumed. Both, two-phase friction factor and viscosity models were determined by Lin correlation and
void fraction from Zivi correlation. This model is included in âIMST-ARTâ, software for simulation and design
of refrigeration equipment. The addition of capillary tube model allows calculating the superheat at the
evaporator giving the capillary tube geometry. A simulation with different operative conditions and capillary
tube geometry is presented and the results are compared with those given by ASHRAE correlation with the
integration of the conservation equations (mass, momentum and energy) over individual control volumes. The
model includes non critical and critical flow conditions. The model assumes thermodynamic equilibrium and
one-dimensional two-phase flow. The meta stable condition is not taken into account.
Jiraporn Sinpiboon et al. (2002) developed a mathematical model to study flow characteristics in non
adiabatic capillary tubes. The theoretical model is based on conservation of mass, energy and momentum of
fluids in the capillary tube and suction line. The mathematical model is categorized into three different cases,
depending on the position of the heat exchange process. The first case is considered when the heat exchange
process start in the single-phase flow region, the second case is determined when the heat exchange process start
at the end of the single-phase flow region, and the last case is considered when the heat exchange process takes
place in the two-phase flow region. A set of differential equations is solved by the explicit method of finite
difference scheme. The model is validated by comparison with the experimental data working with alternative
refrigerants for design and optimization.
Jain et al (2004) studied the effect of capillary tube-suction line heat exchanger (ctslhx) geometry on
system performance was explored at various design and off-design conditions by embedding it in a system
model. A detailed finite-volume model of the capillary tube and suction line, capable of handling all the phase-
change complexities was used. All the ctslhx configurations considered meet the design constraints and didnât
affect the design COP very much. Capillary tubes with large inlet sections and relatively small outlets were
found to give best performance at all the simulated off-design perturbations.
Dongsoo Jung et al. (2006) studied pressure drop through a capillary tube and modeled this pressure drop in an
attempt to predict the size of capillary tubes used in residential air conditioners and also to provide simple
3. Selection of Capillary Tube for Refrigeration System
www.ijeijournal.com Page | 54
correlating equations for practicing engineers. Stoecker's basic model was modified with the consideration of
various effects due to subcooling, area contraction and different equations for viscosity and friction factor, and
finally mixture effect. McAdams' equation for the two-phase viscosity and Stoecker's equation for the friction
factor yielded the best results among various equations. With these equations, the modified model yielded the
performance data that are comparable to those in the ASHRAE handbook. After the model was validated with
experimental data for CFC12, HFC134a, HCFC22, and R407C, performance data were generated for HCFC22
and its alternatives, HFC134a, R407C, and R410A under the following conditions: condensing temperature; 40,
45, 50, 55°C, subcooling; 0, 2.5, 5°C, capillary tube diameter; 1.2â2.4 mm, mass flow rate; 5â50 g/s. These data
showed that the capillary tube length varies uniformly with the changes in condensing temperature and
subcooling. Finally, a regression analysis was performed to determine the dependence of mass flow rate on the
length and diameter of a capillary tube, condensing temperature, and subcooling. Thus in this study simple
practical equations yielded a mean deviation of 2.4% for 1488 data obtained for two pure and two mixed
refrigerants.
Mittal et al. (2009) investigated the effect of coiling on the flow characteristics of R-407C in an
adiabatic spiral capillary tube. The characteristic coiling parameter for a spiral capillary tube is the coil pitch;
hence, the effect of the coil pitch on the mass flow rate of R-407C was studied on several capillary tube test
sections. The authors observed that the coiling of the capillary tube significantly reduced the mass flow rate of
R-407C in the adiabatic spiral capillary tube. In order to quantify the effect of coiling, the experiments were also
conducted for straight a capillary tube, and observed that the coiling of the capillary tube reduced the mass flow
rate in the spiral tube in the range of 9â18% as compared with that in the straight capillary tube. A generalized
non dimensional correlation for the prediction of the mass flow rates of various refrigerants was developed for
the straight capillary tube on the basis of the experimental data of R-407C of the present study, and the data of
R-134a, R-22, and R-410A measured by other researchers. Additionally, a refrigerant-specific correlation for the
spiral capillary was also proposed on the basis of the experimental data of R-407C.
NEGRĂO C.O.R. et al. (1999) worked on a numerical model to simulate the refrigerant flow through capillary
tube-suction line heat exchangers. The refrigerant flow is modelled by the conservation laws of mass,
momentum and energy. The resulting set of equations is solved numerically, but the model is not
unconditionally convergent. It is shown that the divergence source is a discontinuity in the set of equations. The
discontinuity occurs when the slope of the refrigerant flow and saturation pressure profiles, along the capillary
length, are very similar. The results reveal that the discontinuity is fairly sensitive to the subcooling and to the
heat transfer rate to the suction line. Finally, some suggestions are provided in order to overcome the divergence
problem.
Krishna reddy Venna et al. (2012) studied and investigated the flow characteristics of R410a in coiled
non-adiabatic capillary tubes and the performance of spiral capillary tubes which simulate a situation closer to
that existing in practice. The effect of the pitch of spiral on the mass flow rate of refrigerant and the on the
length of capillary was examined in this work. A one-pass-through experiment apparatus is set up for the
experiment. Mass flow rate of R410A through the capillary is measured with different tube geometries and
under various operating conditions through coiled capillary and straight capillary tubes for adiabatic and
diabatic. The mass flow rates of the coiled capillary tubes decreased by 5 to 16% more than those of the straight
capillary tubes at the same operating conditions. The test results show that mass flow rate in a capillary tube
increases with increase of coiled pitch (P), but changes little beyond P = 120 mm.
III. CONCLUSIONS
Optimization of geometrical parameter such as diameter, length, coil pitch, twisted angle of capillary
tube is possible by using experimental methods, mathematical model and by maintaining proper pressure
between condenser and evaporator. The influence of such geometrical parameters on the coefficient of
performance (COP) of the system, pressure drop, refrigerant flow rate, degree of sub cooling is reviewed in this
paper.
REFERENCES
[1]. Amr O. Elsayed, âExperimental study on the performance of twisted capillary tube,â International Refrigeration and Air
Conditioning Conference Purdue University , 2006
[2]. Hirendra Kumar Paliwal1, Keshav Kant2 , â A model for helical capillary tubes for refrigeration systems,â International
Refrigeration and Air Conditioning Conference Purdue University , 2006
[3]. S. M. Sami, P.E., H. Maltais and D. E. Desjardins, âInfluence of Geometrical Parameters on Capillary Behavior with New
Alternative Refrigerants,â M.Tech Thesis, Department of Mechanical Engineering, School of Engineering University of Moncton,
Moncton, 2001.
[4]. Chunlu Zhang, Guoliang Ding, âApproximate analytic solutions of adiabatic capillary tube,â International Journal of Refrigeration
27 (2004) 17â24.
[5]. Akkarat Poolkrajang and Nopporn Preamjai, âOptimization of capillary tube in air conditioning system,â Asian Journal on Energy
and Environment, 2009, 10(03), 165-175.
4. Selection of Capillary Tube for Refrigeration System
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[6]. Akash Deep Singh, âFlow characteristics of refrigerant inside diabatic capillary tube,â Thapar University, Patiala, (2009), pp. 1-96.
[7]. M.A. Akintunde, Ph.D. âEffect of Coiled Capillary Tube Pitch on Vapor Compression Refrigeration System Performance,â The
Pacific Journal of Science and Technology Volume 9. Number 2. November (2008), pp. 284-294.
[8]. Jose Miguel CORBERĂN , David FUENTES , JosĂŠ GONZĂLVEZ, âNumerical calculations of mass flow rate in capillary tubes
using âARTâ an advance simulation software,â Universidad PolitĂŠcnica de Valencia, ETSII, Valencia, Valencia, Spain (2008), pp.
1-10.
[9]. Jiraporn Sinpiboon, Somchai Wongwises, âNumerical Investigation Of refriregent flow through non-adiabetic capillary tubes,â
Applied Theramal Engineering 22(2002) pp. 2015-2032.
[10]. Jain, Gaurav, Bullard, Clark, âDesign and optimization of capillary tubesuction line heat exchangers,â International Refrigeration
and Air Conditioning Conference, Purdue University,2004.
[11]. Dongsoo Jung, Chunkun Park, Byungjin Park, âCapillary tube selection for HCFC22 alternatives,â International Journal of
Refrigeration 22, (2006) pp. 604-614.
[12]. M. K. Mittal, R. Kumar, A. Gupta, âAn Experimental Study of the Flow of R-407C in an Adiabatic Spiral Capillary Tube,â Journal
of Thermal Science and Engineering Applications, Vol. 1, DECEMBER (2009), pp. 041003-041011.
[13]. C. O. R. NegrĂŁo, C. Melo, âShortcomings of the numerical modeling of capillary tubesuction line heat exchangers,â 20th
international congress of refrigeration, iir/iif, sydney, 1999.