The document describes a CFD (computational fluid dynamics) analysis of heat transfer in a dry spent fuel storage cask for a pressurized heavy water reactor. The analysis found that:
1) The maximum temperature of the fuel bundles was 153°C, below the safety limit of 160°C.
2) Air flow patterns were established, with air rising through spaces between fuel bundles and descending along the basket wall and central rod.
3) Temperature increased from bottom to top of fuel bundles, ranging from 120°C to 180°C.
4) Further analysis considering conduction and radiation heat transfer could potentially lower temperatures even more.
Computational Analysis of Thermal Behavior within a Scraped Surface Heat Exch...ijtsrd
In this present work, the Computational analysis of fluid flow and heat transfer within a Scraped Surface Heat Exchanger SSHE , which is an industrial device, is reported. The 3D model of SSHE geometry is achieved with Solid Edge V18. 3D mesh model of SSHE with finite volume discretization obtained in ANSYS ICM CFD code and ANSYS CFX V15 used to solve continuity, momentum and energy equations using multiple rotating reference frame formulation. The steady, laminar, non isothermal flow of pure glycerin Newtonian fluid was investigated. The cooling process without phase change within the SSHE was studied. The different scraper blades of 3 and 2.The inlet velocity of the fluid is varied to evaluate the thermal behavior of SSHE. The different process parameters in the parametric study are rotational velocity, axial velocity and the different scraper blades 3 and 2 . When reducing the number of rotating parts, better cooling is achieved. The variations of the local heat transfer coefficient based on inner wall temperature and bulk fluid temperature as a function of the main process parameters, namely rotational velocity, axial velocity and the different scraper blades obtained. The results have shown that viscous dissipation has a significant effect on the cooling of the glycerine. The local heat transfer coefficient increases gradually when reducing the rotating parts of scraper blades improves the heat transfer rate. Larger increases of the same occurred with higher rotational velocity and axial velocity. If higher the value of rotating velocity=9rps is considered there is a viscous heating occurs and also more number of rotating parts friction is produced on the boundary layer surface and the temperature increases, so 2 scraper blades results shows the better heat transfer performance in bulk fluid temperature and local heat transfer co efficient. This is expected to be useful in the design of SSHEs handling highly viscous fluids. Rajesh S C | Gautham Krishnan | Sreehari P | Akhil Naryanan K | Sibin S Nair "Computational Analysis of Thermal Behavior within a Scraped Surface Heat Exchanger (SSHE)" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25241.pdfPaper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/25241/computational-analysis-of-thermal-behavior-within-a-scraped-surface-heat-exchanger-sshe/rajesh-s-c
Computational Analysis of Thermal Behavior within a Scraped Surface Heat Exch...ijtsrd
In this present work, the Computational analysis of fluid flow and heat transfer within a Scraped Surface Heat Exchanger SSHE , which is an industrial device, is reported. The 3D model of SSHE geometry is achieved with Solid Edge V18. 3D mesh model of SSHE with finite volume discretization obtained in ANSYS ICM CFD code and ANSYS CFX V15 used to solve continuity, momentum and energy equations using multiple rotating reference frame formulation. The steady, laminar, non isothermal flow of pure glycerin Newtonian fluid was investigated. The cooling process without phase change within the SSHE was studied. The different scraper blades of 3 and 2.The inlet velocity of the fluid is varied to evaluate the thermal behavior of SSHE. The different process parameters in the parametric study are rotational velocity, axial velocity and the different scraper blades 3 and 2 . When reducing the number of rotating parts, better cooling is achieved. The variations of the local heat transfer coefficient based on inner wall temperature and bulk fluid temperature as a function of the main process parameters, namely rotational velocity, axial velocity and the different scraper blades obtained. The results have shown that viscous dissipation has a significant effect on the cooling of the glycerine. The local heat transfer coefficient increases gradually when reducing the rotating parts of scraper blades improves the heat transfer rate. Larger increases of the same occurred with higher rotational velocity and axial velocity. If higher the value of rotating velocity=9rps is considered there is a viscous heating occurs and also more number of rotating parts friction is produced on the boundary layer surface and the temperature increases, so 2 scraper blades results shows the better heat transfer performance in bulk fluid temperature and local heat transfer co efficient. This is expected to be useful in the design of SSHEs handling highly viscous fluids. Rajesh S C | Gautham Krishnan | Sreehari P | Akhil Naryanan K | Sibin S Nair "Computational Analysis of Thermal Behavior within a Scraped Surface Heat Exchanger (SSHE)" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25241.pdfPaper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/25241/computational-analysis-of-thermal-behavior-within-a-scraped-surface-heat-exchanger-sshe/rajesh-s-c
ENERGY SAVINGS IN DOMESTIC REFRIGERATOR USING TWO THERMOELECTRIC MODULES& WAT...ijiert bestjournal
The study deals with hybrid refrigerator that combi nes thermoelectric (TER) and vapor compression refrigeration (VCR) and also entail exp erimental details of combined VCR & TER system. Objective is to configure hybrid refrig erator by introducing two Peltier modules (TER) in domestic refrigerator and to analyze compr essor cycles of conventional refrigerator with TER to increase energy efficiency of vapor com pression cycle. For this comparison of standalone VCR and Hybrid VCR+TER system is carried out. A Peltier module of size 4cm � 4cm � .4cm is introduced in the refrigerator cabinet & t he effect on energy efficiency in terms of trip time of compressor is recorded. The e ffect of Air cooled & Water cooled condenser with TER in different structures is also investigated. It is observed that by introducing thermoelectric effect,energy consumpti on of VCR is reduced by almost 10.92% annually,which accounts for 80 units per year. Thu s ultimately improving COP of the hybrid system with better control on temperature over the total run time.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Transient thermal analysis of phase change material based heat sinkseSAT Journals
Abstract Integrated circuits operate best in a limited range of temperature hence their package must be designed to remove the excessive heat. As an alternative passive cooling technique means, phase change materials or PCMs have been widely investigated for such transient cooling applications considering their advantage such as high latent heat of fusion, high specific heat, controllable temperature stability and small volume change during phase change, etc. This PCM based cooling techniques have great potential application in the devices which are not operated continuously over a long period, but in intermittently using devices like cellular phones, digital cameras, notebook etc. The PCM absorbs heat from the electronic component when it operates and melts, the molten PCM needs to be re-solidified by dissipating heat to the surroundings while the electronic device are idle, such a cooling system is applicable only for intermittent use devices and not those in continuous operation. To achieve effective cooling it is important to ensure that the operating duration of the electronic device does not exceed the time of full melting of PCM. Advanced transient analysis is required for clear understanding of the mechanism behind this method of cooling while practical implementations are considered. Controlled convective cooling techniques can be implemented for continuous operation such kind of systems. The present work is a numerical study consists of thermal analysis of various configurations of finned heat sink with PCM. The configurations considered are finned heat sink without PCM and with PCM, Half-filled PCM towards the fin tip side and cases which includes forced convection for systems with continuous operation. The unsteady analyses were performed to record the transient nature of problem. The characteristic of PCM and the design of operational time of convective cooling are estimated. By analyzing these different configurations a vivid picture of the physics of heat transfer in PCM based heat sink is figured out. Keywords: Phase change materials; Heatsink; electronics cooling; Thermal management
Various parameters affecting the performance of a regeneratorIJESFT
Main objective of this review paper is to show how various parameters affect the performance of regenerator. Performance of regenerator is very important parameter to design it. Various parameters which affect the performance of regenerator have been discussed.
Investigation of Different Types of Cement Material on Thermal Properties of ...IJERA Editor
One of the challenges in sustainable development is to optimize the energy efficiency of buildings during their
lifespan. Nowadays the applying of different types of cements in modern concretes provide low embodied CO2
with the intrinsic property called “thermal mass” that reduces the risk of overheating in the summer and
provides passive heating in the winter. Thermal mass is affected by thermal properties of concrete which it is the
ability of the element to exchange heat with the environment and is based on thermal capacity, conductivity, and
density. Laboratory experiments measured density, specific capacity and thermal conductivity of sustainable
concrete mixes with various percentages of GGBS, PFA, SF. The results contribute to the investigation of the
performance of thermal properties performance in sustainable concrete.
Optimization of Air Preheater for compactness of shell by evaluating performa...Nemish Kanwar
Designing of an Air Preheater with increased performance from an existing design through alteration in baffle placement. Analysis of 4 Baffle designs for segmented Baffle case was done using Ansys Fluent. The net heat recovery rate was computed by subtracting pump work from heat recovered. Based on the result, Air Preheater design was recommended.
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.
Analysis of A Double Spiral Counter Flow Calorimeter in Impinging Flame Jet U...IJERA Editor
Enhancement of heat transfer rates in heat exchanger and calorimeter has been reported by many researchers. However, work regarding heat transfer characteristics analysis of double spiral counter flow calorimeter is not published and this forms the objective of this work. DSCFC is a unique design where it consists of single fluid as working fluid for heat exchange. Here heat transfer takes place between solid and fluid, and hence can be called as conjugate heat transfer problem. Heat transfer characteristics DSCFC is observed at various Reynolds number and base temperature. DSCFC is analyzed considering conjugate heat transfer and temperature dependent properties of heat transport media. Computations are performed using commercially available CFD package ANSYS-CFX. It is observed that with increase in Reynolds number of the fluid, heat transfer reduces whereas increase in base temperature increases heat transfer. The Computational results are compared with the experimental.
Comparative studies on heat transfer and fluid flow in cored brick and pebble...eSAT Journals
Abstract
The article reports on comparison of transient heat transfer and fluid flow in two different sensible heat storage devices using Computational Fluid Dynamics. The candidate heat storage devices considered were cored brick and pebble bed and air was taken to be the working fluid. Same geometrical, material, porosity and boundary conditions, have been used for both the cored brick and pebble bed heaters, to compare the axial temperature history and pressure drop. The heat storage system comprises alumina, either in form of pebbles of diameter 6.5 mm, packed to a length of 0.455m in a 43mm diameter pipe, or cored brick of 43mm diameter and same length with through holes to have the same porosity (0.48) as that of the former. The conditions at inlet, outlet and lateral surface too have been taken to be same for both the systems. The fluid flow was considered to be incompressible with k-epsilon model to predict turbulence, and the thermo-physical properties of fluid and solid were assumed to remain constant. Simulations carried out for an inlet temperature of 465 K for velocities ranging from 2m/s to 5 m/s revealed that pressure drop in pebble bed to be considerably higher than those in cored brick, while the temperature history exhibited mixed trends.
Keywords: Cored Brick, Pebble Bed and Porosity
The article deals with the important characteristics required in the design process of short-term and long-term heat batteries, as well as the heat physical properties of heat-collecting materials R.М. Makhmudov, Z.I.Kholmurodova, Sh.А.Usmonov, & S.Sh.Babanazarov. (2020). Efficient principles for heat batteries. International Journal on Orange Technologies, 2(12), 14-17. https://doi.org/10.31149/ijot.v2i12.1005 Pdf Url: https://journals.researchparks.org/index.php/IJOT/article/view/1005/954 Paper Url: https://journals.researchparks.org/index.php/IJOT/article/view/1005
Esign and thermal evaluation of shell and helical coil heat exchangereSAT Journals
Abstract
Heat exchangers are the important engineering equipments used for transferring heat from one fluid to another. Heat exchangers are widely used in various kinds of application such as power plants, nuclear reactors, refrigeration and air-conditioning systems, heat recovery systems, petrochemical, mechanical, biomedical industries. Helical coil heat exchangers are gaining wide importance now-a-days because it can give high heat transfer coefficient in small footprint of surface area. This paper focuses on the designing of shell and helical coil heat exchanger and its thermal evaluation with counter flow configuration. The thermal analysis is carried out considering the various parameters such as flow rate of cold water, flow rate of hot water, temperature, effectiveness and overall heat transfer coefficient.
Keywords— Helical coil heat exchanger, Counter flow, Flow rate, effectiveness, heat transfer coefficient etc.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
VOLUME-7 ISSUE-8, AUGUST 2019 , International Journal of Research in Advent Technology (IJRAT) , ISSN: 2321-9637 (Online) Published By: MG Aricent Pvt Ltd
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
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
ENERGY SAVINGS IN DOMESTIC REFRIGERATOR USING TWO THERMOELECTRIC MODULES& WAT...ijiert bestjournal
The study deals with hybrid refrigerator that combi nes thermoelectric (TER) and vapor compression refrigeration (VCR) and also entail exp erimental details of combined VCR & TER system. Objective is to configure hybrid refrig erator by introducing two Peltier modules (TER) in domestic refrigerator and to analyze compr essor cycles of conventional refrigerator with TER to increase energy efficiency of vapor com pression cycle. For this comparison of standalone VCR and Hybrid VCR+TER system is carried out. A Peltier module of size 4cm � 4cm � .4cm is introduced in the refrigerator cabinet & t he effect on energy efficiency in terms of trip time of compressor is recorded. The e ffect of Air cooled & Water cooled condenser with TER in different structures is also investigated. It is observed that by introducing thermoelectric effect,energy consumpti on of VCR is reduced by almost 10.92% annually,which accounts for 80 units per year. Thu s ultimately improving COP of the hybrid system with better control on temperature over the total run time.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Transient thermal analysis of phase change material based heat sinkseSAT Journals
Abstract Integrated circuits operate best in a limited range of temperature hence their package must be designed to remove the excessive heat. As an alternative passive cooling technique means, phase change materials or PCMs have been widely investigated for such transient cooling applications considering their advantage such as high latent heat of fusion, high specific heat, controllable temperature stability and small volume change during phase change, etc. This PCM based cooling techniques have great potential application in the devices which are not operated continuously over a long period, but in intermittently using devices like cellular phones, digital cameras, notebook etc. The PCM absorbs heat from the electronic component when it operates and melts, the molten PCM needs to be re-solidified by dissipating heat to the surroundings while the electronic device are idle, such a cooling system is applicable only for intermittent use devices and not those in continuous operation. To achieve effective cooling it is important to ensure that the operating duration of the electronic device does not exceed the time of full melting of PCM. Advanced transient analysis is required for clear understanding of the mechanism behind this method of cooling while practical implementations are considered. Controlled convective cooling techniques can be implemented for continuous operation such kind of systems. The present work is a numerical study consists of thermal analysis of various configurations of finned heat sink with PCM. The configurations considered are finned heat sink without PCM and with PCM, Half-filled PCM towards the fin tip side and cases which includes forced convection for systems with continuous operation. The unsteady analyses were performed to record the transient nature of problem. The characteristic of PCM and the design of operational time of convective cooling are estimated. By analyzing these different configurations a vivid picture of the physics of heat transfer in PCM based heat sink is figured out. Keywords: Phase change materials; Heatsink; electronics cooling; Thermal management
Various parameters affecting the performance of a regeneratorIJESFT
Main objective of this review paper is to show how various parameters affect the performance of regenerator. Performance of regenerator is very important parameter to design it. Various parameters which affect the performance of regenerator have been discussed.
Investigation of Different Types of Cement Material on Thermal Properties of ...IJERA Editor
One of the challenges in sustainable development is to optimize the energy efficiency of buildings during their
lifespan. Nowadays the applying of different types of cements in modern concretes provide low embodied CO2
with the intrinsic property called “thermal mass” that reduces the risk of overheating in the summer and
provides passive heating in the winter. Thermal mass is affected by thermal properties of concrete which it is the
ability of the element to exchange heat with the environment and is based on thermal capacity, conductivity, and
density. Laboratory experiments measured density, specific capacity and thermal conductivity of sustainable
concrete mixes with various percentages of GGBS, PFA, SF. The results contribute to the investigation of the
performance of thermal properties performance in sustainable concrete.
Optimization of Air Preheater for compactness of shell by evaluating performa...Nemish Kanwar
Designing of an Air Preheater with increased performance from an existing design through alteration in baffle placement. Analysis of 4 Baffle designs for segmented Baffle case was done using Ansys Fluent. The net heat recovery rate was computed by subtracting pump work from heat recovered. Based on the result, Air Preheater design was recommended.
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.
Analysis of A Double Spiral Counter Flow Calorimeter in Impinging Flame Jet U...IJERA Editor
Enhancement of heat transfer rates in heat exchanger and calorimeter has been reported by many researchers. However, work regarding heat transfer characteristics analysis of double spiral counter flow calorimeter is not published and this forms the objective of this work. DSCFC is a unique design where it consists of single fluid as working fluid for heat exchange. Here heat transfer takes place between solid and fluid, and hence can be called as conjugate heat transfer problem. Heat transfer characteristics DSCFC is observed at various Reynolds number and base temperature. DSCFC is analyzed considering conjugate heat transfer and temperature dependent properties of heat transport media. Computations are performed using commercially available CFD package ANSYS-CFX. It is observed that with increase in Reynolds number of the fluid, heat transfer reduces whereas increase in base temperature increases heat transfer. The Computational results are compared with the experimental.
Comparative studies on heat transfer and fluid flow in cored brick and pebble...eSAT Journals
Abstract
The article reports on comparison of transient heat transfer and fluid flow in two different sensible heat storage devices using Computational Fluid Dynamics. The candidate heat storage devices considered were cored brick and pebble bed and air was taken to be the working fluid. Same geometrical, material, porosity and boundary conditions, have been used for both the cored brick and pebble bed heaters, to compare the axial temperature history and pressure drop. The heat storage system comprises alumina, either in form of pebbles of diameter 6.5 mm, packed to a length of 0.455m in a 43mm diameter pipe, or cored brick of 43mm diameter and same length with through holes to have the same porosity (0.48) as that of the former. The conditions at inlet, outlet and lateral surface too have been taken to be same for both the systems. The fluid flow was considered to be incompressible with k-epsilon model to predict turbulence, and the thermo-physical properties of fluid and solid were assumed to remain constant. Simulations carried out for an inlet temperature of 465 K for velocities ranging from 2m/s to 5 m/s revealed that pressure drop in pebble bed to be considerably higher than those in cored brick, while the temperature history exhibited mixed trends.
Keywords: Cored Brick, Pebble Bed and Porosity
The article deals with the important characteristics required in the design process of short-term and long-term heat batteries, as well as the heat physical properties of heat-collecting materials R.М. Makhmudov, Z.I.Kholmurodova, Sh.А.Usmonov, & S.Sh.Babanazarov. (2020). Efficient principles for heat batteries. International Journal on Orange Technologies, 2(12), 14-17. https://doi.org/10.31149/ijot.v2i12.1005 Pdf Url: https://journals.researchparks.org/index.php/IJOT/article/view/1005/954 Paper Url: https://journals.researchparks.org/index.php/IJOT/article/view/1005
Esign and thermal evaluation of shell and helical coil heat exchangereSAT Journals
Abstract
Heat exchangers are the important engineering equipments used for transferring heat from one fluid to another. Heat exchangers are widely used in various kinds of application such as power plants, nuclear reactors, refrigeration and air-conditioning systems, heat recovery systems, petrochemical, mechanical, biomedical industries. Helical coil heat exchangers are gaining wide importance now-a-days because it can give high heat transfer coefficient in small footprint of surface area. This paper focuses on the designing of shell and helical coil heat exchanger and its thermal evaluation with counter flow configuration. The thermal analysis is carried out considering the various parameters such as flow rate of cold water, flow rate of hot water, temperature, effectiveness and overall heat transfer coefficient.
Keywords— Helical coil heat exchanger, Counter flow, Flow rate, effectiveness, heat transfer coefficient etc.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
VOLUME-7 ISSUE-8, AUGUST 2019 , International Journal of Research in Advent Technology (IJRAT) , ISSN: 2321-9637 (Online) Published By: MG Aricent Pvt Ltd
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
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
This presentation attempts to talk about the current robotic scenario(market, the different applications etc), India's contribution and what the future for robotics looks like.
The Center for Thematic Environmental Networks (TEN) is a Center for education and research in the fields of environment and sustainable development.
TEN Center promotes the exchange of knowledge and information on the environmental field and offers tools and supplementary approaches in order to solve environmental issues with specific reference to sustainable development.
TEN Center:
promotes education and advanced training programs on sustainable development and environmental management;
develops research activities on the main areas of environmental protection, with specific focus on developing countries;
hosts initiatives which provide a meeting platform for the competent authorities, researchers and those who are involved in environmental and sustainable development issues.
Since 2003, TEN manages and coordinates advanced training programs devised for director generals and managers of public administrations, researchers and private sector experts from the People’s Republic of China and Eastern European countries. The aim is to augment and improve the capabilities of policy-makers and to facilitate knowledge transfer in order to promote sustainable environmental, social and economic policies.
Digital technology has made a profound impact on business: it has disrupted organisational structures, created new revenue streams and fundamentally changed the way businesses engage with their customer base. Advancements in analytics, the increasing capability of mobile and the rise of Cloud have completely disrupted traditional models - but the technology only forms half of the picture - transformation requires a change in mindset accompanied by a genuine cultural shift.
Article in Hydrocarbon Engineering September 2019 about K°BOND diffusion bonded heat exchanger, also known as Printed Circuit Heat Exchanger (PCHE).
PCHE is used as recuperator in supercritical CO2 (sCO2) Power Cycles. The Allam Fetvedt cycle is a sCO2 cycle with oxifuel combustion. After the CO2 stream has been used in the power cycle it can be stored underground in depletee oil fields as CCS.
5 heat exchanger thermal design of oil system for turbo centrifugal compresso...IJCMESJOURNAL
A thermal management is vital issues of all energy equipment such as compressor, gas turbine, and boilers etc. The compressor is generally used in power, oil & gas, air separation, and chemical plant. It is consist of air or gas compression part, gear, bearing, cooling, sealing, lube oil, and control system. In this study focused on heat exchanger for oil supply systems. Lube oil is very important to supply oil and protect bearing. Lube oil’s temperature control is vital issue to prevent system broken. Shell and tube heat exchanger is used as a cooler. In this study, HTRI Xist used to thermal design of oil cooler, with water and nanofluid. The thermal conductivity is ~9.3% higher than water. The tube side overall heat transfer coefficient of nanofluid is increased by ~9% compared to that of water.
Paper Statistics:
Transient Thermal Analysis for Heat Dissipation from Engine Cylinder Block wi...ijtsrd
The cost of fuel and materials in all sectors is rising day by day. In the IC engine, the engine fails primarily because the heat transfer from the cylinder wall to the ambient air is inadequate. Heat is derived from the cylinder wall in the engine by means of convection heat transfer through the fins. In this study, a 3 dimensional numerical 3 D transient thermal state simulation was used to investigate the heat dissipation of the engine cylinder fin with holes of different shapes hexagonal and an elliptical . ANSYS 17.0 simulation software was used to research the physiognomy of the heat transfer physiognomies of an engine cylinder fin with and without hole. The results indicate that, the fin with an elliptic hole attain a temperature of 797.94 °C at 14 seconds in comparison to other where with hexagonal hole 798.02 °C, and without hole 798.14°C. So above values clearly shows that fin with an elliptic hole dissipates more heat as compare to fin with hexagonal hole or without hole. Fin with an elliptic hole have a total heat flux of 56122 W m² comparison to other where with hexagonal hole 49967 W m², and without hole 46704 W m². From the above results it is clearly shows that, the new proposed shape fin or fin configuration will greatly improve the heat transfer rate and increase the fin efficiency. Optimum results are obtained when we provide an elliptic hole in an engine cylinder fin Sunil Kumar Bharti | Prof. Rohit Soni "Transient Thermal Analysis for Heat Dissipation from Engine Cylinder Block with Different Shaped Holes in Fins using CFD" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd35736.pdf Paper Url: https://www.ijtsrd.com/engineering/mechanical-engineering/35736/transient-thermal-analysis-for-heat-dissipation-from-engine-cylinder-block-with-different-shaped-holes-in-fins-using-cfd/sunil-kumar-bharti
The International Journal of Mechanical Engineering Research and Technology is an international online journal published Quarterly offers fast publication schedule whilst maintaining rigorous peer review. The use of recommended electronic formats for article delivery expedites the process of All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field of appropriate to ensure that they are likely to be the level of interest and importance of appropriate for the journal.
international research journal of engineering and technology 3 nov.pdfnareshkotra
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining a proper peer review and the use of recommended electronic formats for an article delivery expedites the process of All submitted research articles are subjected to an immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as assure that they are likely to be the level of interest and importance of appropriate for the journal.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule with whilst maintaining a rigorous peer review and the use of recommended electronic formats for article delivery expedites the process of All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure they are likely to be the level of interest and importance appropriate for the journal.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining rigorous peer review the use of recommended electronic formats for article delivery expedites the process All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure they are likely to be the level of interest and importance appropriate for the journal.
Design of Heat Exchanger Network for VCM Distillation Unit Using Pinch Techno...IJERA Editor
In process industries, heat exchanger networks represent an important part of the plant structure. The purpose of the networks is to maximize heat recovery, thereby lowering the overall plant costs. In process industries, during operation of any heat exchanger network (HEN), the major aim is to focus on the best performance of the network As in present condition of fuel crises is one of the major problem faced by many country & industrial utility is majorly depend on this. There is technique called process integration which is used for integrate heat within loop so optimize the given process and minimize the heating load and cooling load .In the present study of heat integration on VCM (vinyl chloride monomer) distillation unit, Heat exchanger network (HEN) is designed by using Aspen energy analyzer V8.0 software. This software implements a methodology for HEN synthesis with the use of pinch technology. Several heat integration networks are designed with different ΔT min and total annualized cost compared to obtain the optimal design. The network with a ΔT min of 90C is the most optimal where the largest energy savings are obtained with the appropriate use of utilities (Save 15.3764% for hot utilities and 47.52% for cold utilities compared with the current plant configuration). Percentage reduction in total operating cost is 18.333%. From calculation Payback Period for new design is 3.15 year. This save could be done through a plant revamp, with the addition of two heat exchangers. This improvement are done in the process associated with this technique are not due to the use of advance unit operation, but to the generation of heat integration scheme. The Pinch Design Method can be employed to give good designs in rapid time and with minimum data.
Thermodynamic Analysis of a Cascade Refrigeration System Based On Carbon Diox...IJERA Editor
Thermodynamic analysis of a cascade refrigeration system that uses carbon dioxide-ammonia (R744-R717) as refrigerant is presented in this paper to determine the optimum condensing temperature of the cascade condenser at given design parameters, to maximize the COP of the system. The design and operating parameters considered in this study include (1) condensing, sub cooling, evaporating and super heating temperatures in the ammonia (R717) high-temperature circuit, (2) temperature difference in the cascade heat exchanger, and (3) evaporating, superheating, condensing and sub cooling in the carbon dioxide (R744) low-temperature circuit. A multilinear regression analysis was employed in order to develop two useful correlations for maximum COP, and optimum condensing temperature.
Cfd modelling of the dry spent fuel storage of a pressurized
1. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
CFD Modelling of the Dry Spent Fuel Storage of a Pressurized
Heavy Water Reactor
Ahmad Hussain1* Hani Sait2
Mechanical Engineering Department, King Abdulaziz University-Rabigh,PO box 344, Rabigh 21911, Saudi Arabia
* E-mail of the corresponding author: ahmadutm@gmail.com
Abstract
Currently, concrete canisters are in use for an interim storage of spent fuels of pressurized heavy water reactors. A
major factor in spent fuel dry storage design and key thermal safety issue is the dissipation of the residual heat
generated by the spent fuel. Also the spent fuel temperature, in a dry storage canister, must be kept below
160 ° to avoid fuel oxidation. In this research, CFD modeling has been done to evaluate the temperature
C
distribution in radial and vertical directions of the spent fuel cask. The temperature distribution inside the fuel basket
is obtained using ANSYS and FLUENT for CFD analysis. The results suggest that when the effects of conduction
and convection are combined and the ambient temperature is taken as 40° then the maximum temperature of the
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fuel bundle is found out to be153° which is below the temperature limit of 160° Therefore, the proposed
C C.
indigenous design of the spent fuel storage cask is safe enough to keep the temperatures of the spent fuel well within
the limits.
Keywords:, CFD, FLUENT, fuel safety, modeling, spent fuel storage
1. Introduction
The pools that were designed initially for short-term storage have become quasi-permanent storages. Wet
storage needs special care to maintain good water chemistry pH-values, chloride and sulphate impurity
concentrations and conductivity. Furthermore it has been found that specified pool water temperature control is
essential for long term spent fuel integrity and to avoid structural damage to the facility. Several sites have
documented degradation/corrosion of the spent fuel assemblies in wet storage resulting mainly from poor water
chemistry control. This degradation of the spent nuclear fuel, in turn, produces several problems that ultimately
result in an increased cost for continued storage and management. Also, wet storing of spent nuclear fuel was
never intended to be permanent.
Therefore, dry storage of spent fuel becomes a viable option after it has cooled to the point where passive heat
transfer from encapsulated fuel to its environment is efficient enough to insure that the fuel element
temperatures are well below values which would lead to significant degradation over the long-term.
A major factor in spent fuel dry storage design and one of the key thermal safety issues for licensing a spent
fuel dry storage system is dissipation of the residual heat generated by the spent fuel. That is, the spent fuel
temperature in a dry storage canister must be kept below 160 ° to avoid fuel oxidation, Iqbal, M.,et.al, 2006.
C
The CANDU spent fuel cask is a cylindrical reinforced concrete shell with a capacity to store 9 sealed fuel
baskets, each containing 54 CANDU 19-element spent fuel bundles. The orthographic views and isometric
views of the spent fuel basket are shown in Figure 1 and Figure 2.
In this design, the atmosphere in the storage basket is air. Fuel bundles are stored in staggered arrangement in
the fuel basket. The fuel bundles are to be kept in position by two fixed perforated plates (Figure 3). The basket
is perfectly sealed to prevent any releases of radioactive material.
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2. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Spent Fuel
Type:19-element fuel bundle
Material: UO2 (natural U)
Height: 495 mm
Diameter: 81.5 mm
Fuel Basket
Material: Stainless steel (SS-304L)
Height: 546 mm
Diameter: 813 mm
Plate dia: 787 mm
Hole dia: 82.5 mm.
Also, the minimum cooling time in the spent fuel bay is 10 years. The decay heat power of 10-year cooled
spent fuel bundle is 5W at the design burnup of 9,000 MWT/MTU. In order to evaluate the maximum fuel rod
temperature in the CANDU dry storage canister under design conditions, one may need to solve a
multi-dimensional heat transfer problem with an extremely complicated geometry where three modes of heat
transfer are superimposed, Armijo, J.S., et.al,2006
There are three modes of heat transfer that are to be considered in a spent fuel storage cask: conduction,
convection and radiation. Conduction and Convection are the dominant modes of heat transfer in a cask.
Radiation heat transfer becomes significant when the temperature of the fuel is very high.
In this analysis, only convective heat transfer is taken into account. Since the fuel basket is completely sealed
therefore there is no entrance of air into the fuel basket and forced convection cannot take place inside the
basket, therefore heat is convicted out of the basket only by natural convection.
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3. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Figure 1: Isometric view of the CANDU spent fuel Figure 2: Orthographic views of spent fuel basket
cask for storing 54 bundles.
2. Methodology
2.1 Defining the Modeling Goals
Natural convection heat transfer inside the fuel basket is to be modeled incorporating the effects of buoyancy. The
boundary conditions are: constant heat flux on every fuel bundle’s surface and constant temperatures on top, side and
bottom surfaces. Boussinesq model is used for density variations and temperature dependency of thermal properties
is also taken into account.
2.2 Creating the Model Geometry and Grid
This step of the solution process requires a geometry modeler and grid generator. For this purpose, Pro-Engineer and
GAMBIT are used for geometry modeling and grid generation respectively.
Using Pro-Engineer, model geometry of the fuel basket is developed, which is then imported to GAMBIT as IGES
file where it’s meshing is done.
In GAMBIT, the top and bottom surfaces are meshed using Quadrilateral type element and the whole volume is then
meshed using Hexahedral elements of Cooper type.
Finally, following five zones are defined for applying boundary conditions:
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4. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
1. Fuel Bundles side surfaces named “const heat flux”.
2. Fuel Bundles top surfaces named “fuel rods top”.
3. Basket side wall named “const temp side”.
4. Basket top surface named “const temp top”.
5. Basket bottom surface named “const temp
These meshed drawings are saved as mesh (*.msh) files. These mesh files are then imported into FLUENT where
the CFD analysis is done.
3. Solid Modeling CFD details
3.1 Importing and Scaling the grid
In FLUENT, the mesh file generated by GAMBIT is imported and its grid is scaled.
3.2 Setting the numerical solver
First, the numerical solver is set to the following specifications:
Solver type: Pressure based
Formulation: Implicit
Space: 3D
Time: steady
Velocity formulation: Absolute
Gradient option: Green-Gauss cell based
3.3 Selecting the physical model
The Energy model is selected as the physical model.
3.4 Defining material properties
The working fluid inside the fuel basket is air. Its thermal properties like viscosity, thermal conductivity and specific
heat are taken temperature dependent. The variations of these properties with temperature are modeled by using
appropriate polynomials. The coefficients of those polynomials are then entered into FLUENT. For density variations,
Boussinesq model is used, Heng, X.,et, al. 2006.
3.5 Prescribing operating conditions
The operating pressure is set to normal atmospheric pressure (i.e.101325 Pa). The effect of gravity is incorporated
in the model by setting the gravity value equal to -9.8 along y-axis. The Boussinesq operating temperature is set to
393 K.
3.6 Applying boundary conditions
Following boundary conditions are applied to the above-defined five zones:
Set “const heat flux”: Heat Flux = 37.853 W/m2
Set “const heat flux”: Heat Flux = 37.853 W/m2
Set “fuel rods top”: Heat Flux = 37.853 W/m2
Set “const temp side”: Temperature = 393 K
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5. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Set “const temp top”: Temperature = 400 K
Set “const temp bottom”: Temperature = 393 K
3.7 Setting up solver controls
The solver controls are set to the following settings:
Equations: Flow and Energy
Pressure-velocity coupling: SIMPLE
Under-Relaxation factors:
- Pressure = 0.3
- Density = 1
- Body Forces = 1
- Momentum = 0.7
Discretization:
- Pressure = PRESTO!
- Momentum = Second Order Upwind
- Energy = Second Order Upwind
3.8 Setting up convergence monitors
The convergence monitors are set appropriately and the plotting of residuals (continuity, x-velocity, y-velocity,
z-velocity, energy) during the calculations has been enabled.
Figure 3: Convergence pattern of the residuals
3.9 Initializing the flow field
The calculations are stared by giving the number of iterations with all velocities = 0 and temperature = 395K.
3.10 Computing and Monitoring the Solution
The discretized conservation equations are solved iteratively. A number of iterations are usually required to reach a
converged solution.
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6. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Convergence is reached when:
1. Changes in solution variables from one iteration to the next are negligible. Residuals provide a mechanism to
help monitor this trend.
2. Overall property conservation is achieved.
The convergence pattern of the residuals for the given problem is shown in Figure 3.
4. Results and Discussion
After the convergence of monitored variables, the data can be displayed in the form of contours and vectors of
temperature and velocity to view the temperature distribution and flow patterns.
For the given problem, three additional planes are defined for the display of data: xy-plane, yz-plane and xz-plane.
These planes pass through the point of origin.
Figure 4 is a temperature contour diagram showing that the temperature is increasing from the bottom to the top of
the fuel bundles. This is due to the fact that, as the air is heated, it moves upward and cold air comes down, thus the
temperature at the bottom (120oC) is lower than that at the top (180oC).
Figure 4: Side view of temperature contour diagram of fuel bundles
Figure 5 and 6 shows the top view of the temperature contour diagram which reveals that temperature is very high in
those regions where the fuel bundles are more clustered. This is due to the fact that heat is highly accumulated in
those regions, thus the temperature goes very high in those regions (i.e. 180oC).
Figure 7 shows the velocity vectors at the top surface of fuel bundles while Figure 8 shows contours of y-velocity at
xy, yz and xz-planes. These figures clearly demonstrate the movement of air inside the fuel basket. Air is coming
upward with maximum velocity (i.e. 0.238m/s) from within the annular spaces of fuel bundles while it is going down
along the basket wall as well as along the central rod.
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7. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Figure 5: Top view of the temperature contour diagram of fuel bundles
Figure 6: Temperature contours at xz-plane
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8. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Figure 7: Velocity vector diagram at the top of fuel bundles
Also, it can be seen that the air above the fuel bundles is mostly static. The boundary layer formation can be
visualized from these diagrams. The xy-plane view shows the boundary layer formation at the basket wall while the
yz-plane view shows the boundary layer formation at the central portion of the fuel basket. The xz-plane view shows
that the air above the fuel bundles is static but it is coming up from the annular spaces of the fuel bundles (as shown
by red-colored portions) and going down along the basket wall (as shown by blue-colored portions).
Table 1 gives the summary of CFD analysis, as reported by FLUENT. Some quantities of major concern like heat
transfer rate, heat transfer area, flow area and fluid volume are given in the table. The maximum, minimum and
mass-weighted average values of certain major parameters are also incorporated in the same table.
5. Conclusion
The maximum fuel rod temperature at some points is about 180oC which is beyond the limit (160oC). However, in
this CFD analysis the conduction and radiation heat transfer were not given due consideration in some sections of the
dry fuel storage geometry which could have resulted in lower fuel rod temperatures. It is expected that if
conduction and radiation effects are incorporated in the analysis of all the sections of dry fuel, then heat transfer will
improve and temperature will certainly reduce because these modes also play a major role in the dissipation of heat
from the fuel bundles. However, the current CFD analysis has given an insight into the heat transfer that has given
confidence in designing such cask.
References
Armijo, J.S., Kar, P. and Misra, M. (2006) “Second generation waste package design and storage concept for the
Yucca Mountain Repository”, Nuclear Engineering & Design, 236 : 2589-2598.
Heng, X., Zuying, G. and Zhiwei, Z. (2006) “A numerical investigation of natural convection heat transfer in
horizontal spent-fuel storage cask”, Nuclear Engineering and Design,. 213: 59-65.
Holman, J.P. (2002) Heat Transfer , 9th Edition, MCGraw-Hill, USA
Iqbal, M., Khan, J. and Mirza, S.M. (2006) “Design study of a modular dry storage facility for typical PWR spent
fuel”, Progress in Nuclear Energy. 48: 487-494.
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9. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Figure 8: Contours of Y-velocity at xy, yz and xz-planes
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10. Mathematical Theory and Modeling www.iiste.org
ISSN 2224-5804 (Paper) ISSN 2225-0522 (Online)
Vol.2, No.10, 2012
Table 1: Summary of CFD analysis
FLUENT Reported Data
Heat Transfer Rate (W) 269.24
Heat Transfer Area (m2) 7.113
Total Flow Area (m2) 0.2368
Total Fluid Volume (m3) 0.1434
Maximum Minimum Mass-weighted average
Static Temperature (K) 453 393 420
X – velocity (m/s) 0.120 0.0000434 -
Y- velocity (m/s) 0.116 0.00746 -
Z – velocity (m/s) 0.119 0.00363 -
Total Velocity (m/s) 0.2376 0.000386 0.056
Prandtl Number 2.926 2.265 2.566
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