The document summarizes phase change materials (PCMs) and their applications for latent heat storage. It discusses:
1. PCMs store and release large amounts of heat energy during phase transitions from solid to liquid or vice versa. This allows for high energy storage density compared to sensible heat storage.
2. PCMs can be classified as organic, inorganic, or eutectic materials. Common organic PCMs include paraffin and fatty acids which have high latent heats but low thermal conductivity. Inorganic PCMs like salt hydrates do not supercool and have stable phase change properties over cycling.
3. PCMs are promising for applications in solar energy storage and
A review on phase change materials & their applicationsiaemedu
The document is a review article on phase change materials (PCMs) and their applications. It discusses that PCMs can store large amounts of heat or cold in the form of latent heat during phase transition from solid to liquid or vice versa. This allows PCMs to store 2-3 times more energy per unit volume compared to sensible heat storage. The article then reviews different types of PCMs including organic, inorganic, and eutectic PCMs. Organic PCMs are further divided into paraffin and non-paraffin materials. Several properties of ideal PCMs for thermal energy storage applications are also outlined.
This document discusses thermal energy storage using phase change materials (PCMs). PCMs can effectively store thermal energy during phase transitions from solid to liquid or vice versa, providing high energy storage density. Some commonly used PCMs are salt hydrates and hydrocarbons. Thermal energy stored as latent heat during phase changes can be 5-10 times more dense than thermal energy stored sensibly through temperature changes alone. The document outlines applications of PCM thermal storage in building insulation and solar energy systems.
Investigation of solar cooker with pcm heat storageiaemedu
This document summarizes an experimental investigation of a solar cooker with phase change material (PCM) heat storage for use in high altitude places like Taif City, Saudi Arabia. The solar cooker system consists of evacuated tube solar collectors connected to a hot water storage tank. The base of the solar cooker box is connected to a copper tube heat exchanger inside a cylindrical pot filled with paraffin PCM. Hot water from the solar collectors is circulated through the heat exchanger to store thermal energy in the PCM and heat the cooking pot. Parameters like solar radiation, humidity, cooker orientation, and ambient temperature were evaluated. The study shows this system can effectively cook and heat food under high altitude conditions with partial cloud cover and moderate
A phase change material (PCM) is a substance with a high heat of fusion which, melting and solidifying at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa; thus, PCMs are classified as latent heat storage (LHS) units.
This document discusses using phase changing materials (PCMs) for thermal energy storage. PCMs absorb heat when melting from solid to liquid at a certain temperature range, and release heat when solidifying from liquid to solid. The author proposes storing PCMs in building walls and HVAC systems to help maintain comfortable indoor temperatures and reduce energy usage. Various PCM options are described, along with encapsulation methods to control volume changes and prevent reactivity. Techniques for increasing PCM thermal conductivity, like adding metallic fillers or fins, are also summarized. The conclusion reiterates that further PCM research and system design optimization could improve energy storage efficiency.
Phase change materials or PCMs are compounds which store and release latent heat by changing chemical bonds through a phase alteration. These materials absorb energy during the heating and release energy to the surroundings through a reverse cooling process. The integration of PCM in textiles by coating, encapsulation or any other means has grown concentration to the scientist. In this paper; characteristics, classification, working principle of PCMs and its versatile application in textiles are mainly discussed.
This document discusses phase change materials (PCMs) which can store and release large amounts of thermal energy during phase transitions between solid and liquid states. PCMs provide high energy storage density with small temperature changes. Thermal energy storage methods include sensible heat storage based on temperature change and latent heat storage using phase change. PCMs are classified as organic, inorganic, or eutectic and are selected based on properties like melting temperature and thermal stability. Applications of PCMs include construction materials, textiles, food/medical packaging, and automobiles.
A review on phase change materials & their applicationsiaemedu
The document is a review article on phase change materials (PCMs) and their applications. It discusses that PCMs can store large amounts of heat or cold in the form of latent heat during phase transition from solid to liquid or vice versa. This allows PCMs to store 2-3 times more energy per unit volume compared to sensible heat storage. The article then reviews different types of PCMs including organic, inorganic, and eutectic PCMs. Organic PCMs are further divided into paraffin and non-paraffin materials. Several properties of ideal PCMs for thermal energy storage applications are also outlined.
This document discusses thermal energy storage using phase change materials (PCMs). PCMs can effectively store thermal energy during phase transitions from solid to liquid or vice versa, providing high energy storage density. Some commonly used PCMs are salt hydrates and hydrocarbons. Thermal energy stored as latent heat during phase changes can be 5-10 times more dense than thermal energy stored sensibly through temperature changes alone. The document outlines applications of PCM thermal storage in building insulation and solar energy systems.
Investigation of solar cooker with pcm heat storageiaemedu
This document summarizes an experimental investigation of a solar cooker with phase change material (PCM) heat storage for use in high altitude places like Taif City, Saudi Arabia. The solar cooker system consists of evacuated tube solar collectors connected to a hot water storage tank. The base of the solar cooker box is connected to a copper tube heat exchanger inside a cylindrical pot filled with paraffin PCM. Hot water from the solar collectors is circulated through the heat exchanger to store thermal energy in the PCM and heat the cooking pot. Parameters like solar radiation, humidity, cooker orientation, and ambient temperature were evaluated. The study shows this system can effectively cook and heat food under high altitude conditions with partial cloud cover and moderate
A phase change material (PCM) is a substance with a high heat of fusion which, melting and solidifying at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa; thus, PCMs are classified as latent heat storage (LHS) units.
This document discusses using phase changing materials (PCMs) for thermal energy storage. PCMs absorb heat when melting from solid to liquid at a certain temperature range, and release heat when solidifying from liquid to solid. The author proposes storing PCMs in building walls and HVAC systems to help maintain comfortable indoor temperatures and reduce energy usage. Various PCM options are described, along with encapsulation methods to control volume changes and prevent reactivity. Techniques for increasing PCM thermal conductivity, like adding metallic fillers or fins, are also summarized. The conclusion reiterates that further PCM research and system design optimization could improve energy storage efficiency.
Phase change materials or PCMs are compounds which store and release latent heat by changing chemical bonds through a phase alteration. These materials absorb energy during the heating and release energy to the surroundings through a reverse cooling process. The integration of PCM in textiles by coating, encapsulation or any other means has grown concentration to the scientist. In this paper; characteristics, classification, working principle of PCMs and its versatile application in textiles are mainly discussed.
This document discusses phase change materials (PCMs) which can store and release large amounts of thermal energy during phase transitions between solid and liquid states. PCMs provide high energy storage density with small temperature changes. Thermal energy storage methods include sensible heat storage based on temperature change and latent heat storage using phase change. PCMs are classified as organic, inorganic, or eutectic and are selected based on properties like melting temperature and thermal stability. Applications of PCMs include construction materials, textiles, food/medical packaging, and automobiles.
An Assessment of Phase Change Materials for Domestic ApplicatonsEditorIJAERD
Thermal Energy storage has been the significant area of research over the last many decades. Various methods
and materials are developed for storing heat energy. Yet a main obstacle to modern methods is its lack of thermal mass.
Phase change materials are one of the optimized alternate to various energy storing methods and materials. They have
high energy storage capacity. In any case, despite the fact that the data is quantitatively tremendous, it is moreover
spread generally in the writing, and hard to discover. This report contrasts on the properties of phase change materials
and also reveals their significant applications. Furthermore, the discussion includes main benefits and drawbacks of
phase change materials over the different renewable energy sources. It also carries various types of PCMs and
performance analysis of PCMs for selecting the best required PCM for the purpose of heating and cooling of building.
This document discusses phase change materials (PCMs) for energy storage applications. It begins with an introduction to PCMs and their characteristics like high energy storage density and ability to store/release energy at a constant temperature. It then covers classifications of organic and inorganic PCMs and compares their properties. Challenges like low thermal conductivity of organic PCMs are discussed along with solutions like adding thermal conductivity enhancers. The document concludes that PCMs are promising for energy storage due to their high storage density and ability to store/release energy at constant temperatures.
Review of magnetic refrigeration system as alternative to conventional refrig...Naji Abdullah
The refrigeration system is one of the most important systems in industry.
Developers are constantly seeking for how to avoid the damage to the environment. Magnetic
refrigeration is an emerging, environment-friendly technology based on a magnetic solid that
acts as a refrigerant by magneto-caloric effect (MCE). In the case of ferromagnetic materials,
MCE warms as the magnetic moments of the atom are aligned by the application of a magnetic
field. There are two types of magnetic phase changes that may occur at the Curie point: first
order magnetic transition (FOMT) and second order magnetic transition (SOMT). The
reference cycle for magnetic refrigeration is AMR (Active Magnetic Regenerative cycle),
where the magnetic material matrix works both as a refrigerating medium and as a heat
regenerating medium, while the fluid flowing in the porous matrix works as a heat transfer
medium. Regeneration can be accomplished by blowing a heat transfer fluid in a reciprocating
fashion through the regenerator made of magnetocaloric material that is alternately magnetized
and demagnetized. Many magnetic refrigeration prototypes with different designs and software
models have been built in different parts of the world. In this paper, the authors try to shed
light on the magnetic refrigeration and show its effectiveness compared with conventional
refrigeration methods.
Balucan et al_2014_Energy cost of heat activating serpentinites for CO2 stora...Reydick D Balucan
This document discusses the energy cost of heat activating serpentinites for CO2 storage through mineralization. It finds that directly combusting natural gas to heat serpentinite to 700°C, achieving 20% residual hydroxyl content, and recovering 80% of sensible heat, requires 574 MJ per tonne of serpentinite with only 7% CO2 penalty. This practical heating strategy results in 0.93 tonnes of available active serpentine per tonne of feedstock at a cost of $1.25 per tonne. In comparison to previous estimates using electric heating, this approach reduces costs and secondary CO2 emissions.
IRJET- Effect of Volume Concentration on Various Thermo-Physical Properties o...IRJET Journal
This document presents a theoretical analysis of the effect of volume concentration on various thermo-physical properties of copper oxide (CuO) nanofluid used in a flat plate solar collector. A mathematical model and MATLAB code were developed to calculate properties like density, specific heat, thermal conductivity, viscosity, and Nusselt number. The results showed that density, viscosity, and thermal conductivity increased with higher nanoparticle volume concentration, while specific heat decreased. The Nusselt number also increased with higher volume concentration and larger nanoparticle diameter. In conclusion, CuO nanofluid can enhance the efficiency of flat plate solar collectors due to improved thermo-physical properties at higher nanoparticle concentrations and diameters.
Sensible heat energy storage technology using low cost locally available ther...Husain Mehdi
Thermal energy storage in packed beds is increasing attention due to necessary component for efficient utilization of solar energy. A one dimensional thermal model for the behavior of a packed bed is presented for low cost thermal energy sensible heat energy storage materials (i.e. stone, glass, rocks, bricks, and granite) and air as the heat transfer fluid. This model predicts successfully during storage are presented for brick and rock in a cylindrical packed bed storage unit. Explicit expression for time variation of storage material temperature and air flowing in the system have been developed and performance parameters have been computed for five storage materials.
IRJET- A Review on Utilization of Phase Change Material in Solar Water Heatin...IRJET Journal
This document reviews the use of phase change materials (PCMs) in solar water heating systems. It discusses how PCMs can provide thermal energy storage to improve system efficiency by storing solar energy for use when sunlight is unavailable. The document examines different types of PCMs used, including paraffin and sodium acetate trihydrate. It also explores applications of PCMs in building walls, roofs, and windows to stabilize indoor temperatures. The review finds that solar water heaters equipped with PCMs can provide hot water at night, improving on conventional systems only able to heat water during the day.
Simulation Studies Of Premixed N-Pentane/Air Liquid Micro CombustionIJERA Editor
With latest improvements in MEMS, combustion based Micro-Power generation devices are seen as alternatives for conventional batteries because of the high energy densities of Hydrogen and other hydrocarbon fuels. An important feature of micro-power system is to utilize the combustion of fuel or propellant in the micro-burner to produce the gas with high temperature and high pressure to drive turbines or other power units, which convert chemical into energy directly or indirectly other forms of energy, for example heat or power. We have concentrated on the usage of Micro combustion as a substitute for conventional batteries .In our study, a Micro Combustor of 1mm x 10mm is taken for Numerical Study. Combustion characteristics of N Pentane-Air mixture in a planar micro-channel is studied numerically. We have performed the liquid fuel combustion of n-Pentane and air to study the effects of liquid fuel combustion in a micro channel. The effect of axial velocity inlet, on exhaust gas temperature and Hydrogen Peroxide addition on exhaust gas concentration was analyzed respectively. We also investigated numerically the combustion characteristics under different conditions such as by varying the DPM, Number of Fuel Streams, and Spray Angle and so on. For this numerical analysis, an experimental model is considered as reference, and the geometry and the boundary conditions are taken from it for the purpose of simulation. In this study, n-Pentane is introduced as liquid droplets at the centerline and the liquid combustion is simulated numerically.
Experimental Study on Phase Change Material based Thermal Energy Storage SystemIRJET Journal
1) The document describes an experimental study on using phase change materials (PCMs) like calcium chloride hexahydrate and sodium carbonate decahydrate to store thermal energy.
2) The experiment involved charging two PCMs by flowing hot water through a copper tube containing the PCMs, and discharging by flowing cold water, measuring temperatures over time.
3) The results showed that increasing the flow rate of the heat transfer fluid during charging and discharging increased the heat storage and release capacity of both PCMs.
Thermal energy storage materials and systems for solar energy applicationsSivanjaneya Reddy
How to enhance thermal conductivity for phase change materials and selection of phase change material and about systems for solar energy application has been presented
The document discusses using carbon nanotubes (CNTs) for hydrogen storage through chemisorption. CNTs are promising for hydrogen storage due to their high surface area and ability to form strong carbon-hydrogen bonds. Experimental results using X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) showed hydrogen could bond to CNTs at a level of 5.1% by weight, close to the theoretical maximum capacity, though challenges with kinetics and reversibility at room temperature remain.
Performance analysis of packed bed sensible heat thermal energy storage with...Ganesh Warkhade
This document summarizes research on the performance of a packed-bed thermal energy storage system using small-sized concrete material. The researchers tested different shapes of concrete material - spheres, cubes, and cylinders - in an experimental setup and analyzed temperature distribution, energy storage quantity, charging and discharging times, and pressure drop. Their results showed that cylinders provided better energy storage performance than spheres or cubes. Void fraction also affected energy storage quantity and pressure drop, with higher void fractions allowing more storage but also greater pressure drop. Faster flow rates led to shorter charging times but also faster discharging.
The hydrogen economy has been under rapid growth and development in recent years. Metal hydride based hydrogen storage systems deserve attention as they offer higher storage densities compared to high-pressure gas storage. It is the most compatible and economic method to store hydrogen. In these metal hydride storage devices, low heat transfer has been a key issue. The heat transfer rate can be enhanced by using various techniques.
A two-dimensional numerical analysis of coupled heat and mass transfer processes in a cylindrical metal hydride reactor containing MmNi4·6Al0·4 is presented. Performance studies on MmNi4·6Al0·4 based hydrogen storage device are carried out by varying the hydrogen supply pressure, absorption (cooling fluid) temperature and hydride bed thickness.
This document discusses the use of phase change materials (PCMs) for storing solar thermal energy. PCMs can store large amounts of heat without a large temperature change when melting and releasing heat during solidification. Common PCMs include salt hydrates, paraffins, and non-paraffin organics. PCMs provide advantages over sensible heat storage materials like higher energy density and ability to store and release heat isothermally. The document explores different types of PCMs and their heat storage capacities, concluding that PCMs are a wise alternative for solar energy storage applications.
Phase change materials (PCMs) can store and release large amounts of heat energy as they change phase between solid and liquid states. There are three main types of thermal energy storage: sensible heat, latent heat, and thermochemical heat. Latent heat storage uses PCMs, which absorb or release heat during phase changes without changing temperature. Common PCMs include salt hydrates, paraffin waxes, and fatty acids. PCMs can be encapsulated in small spheres or other shapes to improve heat transfer properties and prevent leakage. Encapsulated PCMs have applications in building insulation, solar energy storage, textiles, and more.
This document presents an experimental study comparing the performance of two box-type solar cookers: one with a plain absorber plate and one with a finned absorber plate. The cookers were tested under conditions in Allahabad, India. It was found that the solar cooker with the finned base performed better, with a higher first figure of merit (F1) of 0.145 compared to 0.106 for the plain base cooker. Exergy efficiency was also higher for the finned base cooker. The study concludes that the finned base design improves the thermal performance of the box-type solar cooker.
This term paper examines momentum and energy exchange between suspended phase change material (PCM) particles and fluid flowing in a pipe. The student proposes to model turbulent flow and consider the effects of gravity, unlike previous studies that assumed laminar flow. The governing equations for the two-phase fluid-particle system are presented, including the continuity, momentum, energy, and turbulence kinetic energy equations. The trajectory of discrete PCM particles will be determined by integrating the particle force balance equation. The goal is to show that adding PCM particles can increase the thermal capacity of the fluid.
This document presents 14 case studies evaluating the techno-economic performance of solid sorbent-based carbon capture and storage (CCS) at pulverized coal power plants. The case studies find that a solid sorbent CCS system can achieve comparable efficiency to liquid amine systems but with a levelized cost of electricity around $161/MWh. High capital costs, particularly for heat exchangers, contribute significantly to the cost. Additional cases explore the potential effects of sorbent degradation and identify heat exchanger design as an area for cost reduction.
World Renewable Energy Congress (WREC) was held at Linkoping, Sweden in May 2011.
Under the broad classification of Solar Thermal Heating (STH) applications, the topic of this paper is "An exergy based unified test protocol for solar cookers of different geometries".
Adaptive load balancing techniques in global scale grid environmentiaemedu
The document discusses various adaptive load balancing techniques for distributed applications in grid environments. It first describes adaptive mesh refinement algorithms that partition computational domains using space-filling curves or by distributing grids independently or at different levels. It also discusses dynamic load balancing using tiling and multi-criteria geometric partitioning. The document then covers repartitioning algorithms based on multilevel diffusion and the adaptive characteristics of structured adaptive mesh refinement applications. Finally, it discusses adaptive workload balancing on heterogeneous resources by benchmarking resource characteristics and estimating application parameters to find optimal load distribution.
A novel approach for satellite imagery storage by classifyiaemedu
This document presents a novel approach for classifying and storing satellite imagery by detecting and storing only non-duplicate regions. It uses kernel principal component analysis to reduce the dimensionality and extract features of satellite images. Fuzzy N-means clustering is then used to segment the images into blocks. A duplication detection algorithm compares blocks to identify duplicate and non-duplicate regions. Only the non-duplicate regions are stored in the database, improving storage efficiency and updating speed compared to completely replacing existing images. Support vector machines are used to categorize the non-duplicate blocks into the appropriate classes in the existing images.
An Assessment of Phase Change Materials for Domestic ApplicatonsEditorIJAERD
Thermal Energy storage has been the significant area of research over the last many decades. Various methods
and materials are developed for storing heat energy. Yet a main obstacle to modern methods is its lack of thermal mass.
Phase change materials are one of the optimized alternate to various energy storing methods and materials. They have
high energy storage capacity. In any case, despite the fact that the data is quantitatively tremendous, it is moreover
spread generally in the writing, and hard to discover. This report contrasts on the properties of phase change materials
and also reveals their significant applications. Furthermore, the discussion includes main benefits and drawbacks of
phase change materials over the different renewable energy sources. It also carries various types of PCMs and
performance analysis of PCMs for selecting the best required PCM for the purpose of heating and cooling of building.
This document discusses phase change materials (PCMs) for energy storage applications. It begins with an introduction to PCMs and their characteristics like high energy storage density and ability to store/release energy at a constant temperature. It then covers classifications of organic and inorganic PCMs and compares their properties. Challenges like low thermal conductivity of organic PCMs are discussed along with solutions like adding thermal conductivity enhancers. The document concludes that PCMs are promising for energy storage due to their high storage density and ability to store/release energy at constant temperatures.
Review of magnetic refrigeration system as alternative to conventional refrig...Naji Abdullah
The refrigeration system is one of the most important systems in industry.
Developers are constantly seeking for how to avoid the damage to the environment. Magnetic
refrigeration is an emerging, environment-friendly technology based on a magnetic solid that
acts as a refrigerant by magneto-caloric effect (MCE). In the case of ferromagnetic materials,
MCE warms as the magnetic moments of the atom are aligned by the application of a magnetic
field. There are two types of magnetic phase changes that may occur at the Curie point: first
order magnetic transition (FOMT) and second order magnetic transition (SOMT). The
reference cycle for magnetic refrigeration is AMR (Active Magnetic Regenerative cycle),
where the magnetic material matrix works both as a refrigerating medium and as a heat
regenerating medium, while the fluid flowing in the porous matrix works as a heat transfer
medium. Regeneration can be accomplished by blowing a heat transfer fluid in a reciprocating
fashion through the regenerator made of magnetocaloric material that is alternately magnetized
and demagnetized. Many magnetic refrigeration prototypes with different designs and software
models have been built in different parts of the world. In this paper, the authors try to shed
light on the magnetic refrigeration and show its effectiveness compared with conventional
refrigeration methods.
Balucan et al_2014_Energy cost of heat activating serpentinites for CO2 stora...Reydick D Balucan
This document discusses the energy cost of heat activating serpentinites for CO2 storage through mineralization. It finds that directly combusting natural gas to heat serpentinite to 700°C, achieving 20% residual hydroxyl content, and recovering 80% of sensible heat, requires 574 MJ per tonne of serpentinite with only 7% CO2 penalty. This practical heating strategy results in 0.93 tonnes of available active serpentine per tonne of feedstock at a cost of $1.25 per tonne. In comparison to previous estimates using electric heating, this approach reduces costs and secondary CO2 emissions.
IRJET- Effect of Volume Concentration on Various Thermo-Physical Properties o...IRJET Journal
This document presents a theoretical analysis of the effect of volume concentration on various thermo-physical properties of copper oxide (CuO) nanofluid used in a flat plate solar collector. A mathematical model and MATLAB code were developed to calculate properties like density, specific heat, thermal conductivity, viscosity, and Nusselt number. The results showed that density, viscosity, and thermal conductivity increased with higher nanoparticle volume concentration, while specific heat decreased. The Nusselt number also increased with higher volume concentration and larger nanoparticle diameter. In conclusion, CuO nanofluid can enhance the efficiency of flat plate solar collectors due to improved thermo-physical properties at higher nanoparticle concentrations and diameters.
Sensible heat energy storage technology using low cost locally available ther...Husain Mehdi
Thermal energy storage in packed beds is increasing attention due to necessary component for efficient utilization of solar energy. A one dimensional thermal model for the behavior of a packed bed is presented for low cost thermal energy sensible heat energy storage materials (i.e. stone, glass, rocks, bricks, and granite) and air as the heat transfer fluid. This model predicts successfully during storage are presented for brick and rock in a cylindrical packed bed storage unit. Explicit expression for time variation of storage material temperature and air flowing in the system have been developed and performance parameters have been computed for five storage materials.
IRJET- A Review on Utilization of Phase Change Material in Solar Water Heatin...IRJET Journal
This document reviews the use of phase change materials (PCMs) in solar water heating systems. It discusses how PCMs can provide thermal energy storage to improve system efficiency by storing solar energy for use when sunlight is unavailable. The document examines different types of PCMs used, including paraffin and sodium acetate trihydrate. It also explores applications of PCMs in building walls, roofs, and windows to stabilize indoor temperatures. The review finds that solar water heaters equipped with PCMs can provide hot water at night, improving on conventional systems only able to heat water during the day.
Simulation Studies Of Premixed N-Pentane/Air Liquid Micro CombustionIJERA Editor
With latest improvements in MEMS, combustion based Micro-Power generation devices are seen as alternatives for conventional batteries because of the high energy densities of Hydrogen and other hydrocarbon fuels. An important feature of micro-power system is to utilize the combustion of fuel or propellant in the micro-burner to produce the gas with high temperature and high pressure to drive turbines or other power units, which convert chemical into energy directly or indirectly other forms of energy, for example heat or power. We have concentrated on the usage of Micro combustion as a substitute for conventional batteries .In our study, a Micro Combustor of 1mm x 10mm is taken for Numerical Study. Combustion characteristics of N Pentane-Air mixture in a planar micro-channel is studied numerically. We have performed the liquid fuel combustion of n-Pentane and air to study the effects of liquid fuel combustion in a micro channel. The effect of axial velocity inlet, on exhaust gas temperature and Hydrogen Peroxide addition on exhaust gas concentration was analyzed respectively. We also investigated numerically the combustion characteristics under different conditions such as by varying the DPM, Number of Fuel Streams, and Spray Angle and so on. For this numerical analysis, an experimental model is considered as reference, and the geometry and the boundary conditions are taken from it for the purpose of simulation. In this study, n-Pentane is introduced as liquid droplets at the centerline and the liquid combustion is simulated numerically.
Experimental Study on Phase Change Material based Thermal Energy Storage SystemIRJET Journal
1) The document describes an experimental study on using phase change materials (PCMs) like calcium chloride hexahydrate and sodium carbonate decahydrate to store thermal energy.
2) The experiment involved charging two PCMs by flowing hot water through a copper tube containing the PCMs, and discharging by flowing cold water, measuring temperatures over time.
3) The results showed that increasing the flow rate of the heat transfer fluid during charging and discharging increased the heat storage and release capacity of both PCMs.
Thermal energy storage materials and systems for solar energy applicationsSivanjaneya Reddy
How to enhance thermal conductivity for phase change materials and selection of phase change material and about systems for solar energy application has been presented
The document discusses using carbon nanotubes (CNTs) for hydrogen storage through chemisorption. CNTs are promising for hydrogen storage due to their high surface area and ability to form strong carbon-hydrogen bonds. Experimental results using X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) showed hydrogen could bond to CNTs at a level of 5.1% by weight, close to the theoretical maximum capacity, though challenges with kinetics and reversibility at room temperature remain.
Performance analysis of packed bed sensible heat thermal energy storage with...Ganesh Warkhade
This document summarizes research on the performance of a packed-bed thermal energy storage system using small-sized concrete material. The researchers tested different shapes of concrete material - spheres, cubes, and cylinders - in an experimental setup and analyzed temperature distribution, energy storage quantity, charging and discharging times, and pressure drop. Their results showed that cylinders provided better energy storage performance than spheres or cubes. Void fraction also affected energy storage quantity and pressure drop, with higher void fractions allowing more storage but also greater pressure drop. Faster flow rates led to shorter charging times but also faster discharging.
The hydrogen economy has been under rapid growth and development in recent years. Metal hydride based hydrogen storage systems deserve attention as they offer higher storage densities compared to high-pressure gas storage. It is the most compatible and economic method to store hydrogen. In these metal hydride storage devices, low heat transfer has been a key issue. The heat transfer rate can be enhanced by using various techniques.
A two-dimensional numerical analysis of coupled heat and mass transfer processes in a cylindrical metal hydride reactor containing MmNi4·6Al0·4 is presented. Performance studies on MmNi4·6Al0·4 based hydrogen storage device are carried out by varying the hydrogen supply pressure, absorption (cooling fluid) temperature and hydride bed thickness.
This document discusses the use of phase change materials (PCMs) for storing solar thermal energy. PCMs can store large amounts of heat without a large temperature change when melting and releasing heat during solidification. Common PCMs include salt hydrates, paraffins, and non-paraffin organics. PCMs provide advantages over sensible heat storage materials like higher energy density and ability to store and release heat isothermally. The document explores different types of PCMs and their heat storage capacities, concluding that PCMs are a wise alternative for solar energy storage applications.
Phase change materials (PCMs) can store and release large amounts of heat energy as they change phase between solid and liquid states. There are three main types of thermal energy storage: sensible heat, latent heat, and thermochemical heat. Latent heat storage uses PCMs, which absorb or release heat during phase changes without changing temperature. Common PCMs include salt hydrates, paraffin waxes, and fatty acids. PCMs can be encapsulated in small spheres or other shapes to improve heat transfer properties and prevent leakage. Encapsulated PCMs have applications in building insulation, solar energy storage, textiles, and more.
This document presents an experimental study comparing the performance of two box-type solar cookers: one with a plain absorber plate and one with a finned absorber plate. The cookers were tested under conditions in Allahabad, India. It was found that the solar cooker with the finned base performed better, with a higher first figure of merit (F1) of 0.145 compared to 0.106 for the plain base cooker. Exergy efficiency was also higher for the finned base cooker. The study concludes that the finned base design improves the thermal performance of the box-type solar cooker.
This term paper examines momentum and energy exchange between suspended phase change material (PCM) particles and fluid flowing in a pipe. The student proposes to model turbulent flow and consider the effects of gravity, unlike previous studies that assumed laminar flow. The governing equations for the two-phase fluid-particle system are presented, including the continuity, momentum, energy, and turbulence kinetic energy equations. The trajectory of discrete PCM particles will be determined by integrating the particle force balance equation. The goal is to show that adding PCM particles can increase the thermal capacity of the fluid.
This document presents 14 case studies evaluating the techno-economic performance of solid sorbent-based carbon capture and storage (CCS) at pulverized coal power plants. The case studies find that a solid sorbent CCS system can achieve comparable efficiency to liquid amine systems but with a levelized cost of electricity around $161/MWh. High capital costs, particularly for heat exchangers, contribute significantly to the cost. Additional cases explore the potential effects of sorbent degradation and identify heat exchanger design as an area for cost reduction.
World Renewable Energy Congress (WREC) was held at Linkoping, Sweden in May 2011.
Under the broad classification of Solar Thermal Heating (STH) applications, the topic of this paper is "An exergy based unified test protocol for solar cookers of different geometries".
Adaptive load balancing techniques in global scale grid environmentiaemedu
The document discusses various adaptive load balancing techniques for distributed applications in grid environments. It first describes adaptive mesh refinement algorithms that partition computational domains using space-filling curves or by distributing grids independently or at different levels. It also discusses dynamic load balancing using tiling and multi-criteria geometric partitioning. The document then covers repartitioning algorithms based on multilevel diffusion and the adaptive characteristics of structured adaptive mesh refinement applications. Finally, it discusses adaptive workload balancing on heterogeneous resources by benchmarking resource characteristics and estimating application parameters to find optimal load distribution.
A novel approach for satellite imagery storage by classifyiaemedu
This document presents a novel approach for classifying and storing satellite imagery by detecting and storing only non-duplicate regions. It uses kernel principal component analysis to reduce the dimensionality and extract features of satellite images. Fuzzy N-means clustering is then used to segment the images into blocks. A duplication detection algorithm compares blocks to identify duplicate and non-duplicate regions. Only the non-duplicate regions are stored in the database, improving storage efficiency and updating speed compared to completely replacing existing images. Support vector machines are used to categorize the non-duplicate blocks into the appropriate classes in the existing images.
A survey of mitigating routing misbehavior in mobile ad hoc networksiaemedu
This document summarizes existing methods to detect misbehavior in mobile ad hoc networks (MANETs). It discusses how routing protocols assume nodes will cooperate fully, but misbehavior like packet dropping can occur. It describes several techniques to detect misbehavior, including watchdog, ACK/SACK, TWOACK, S-TWOACK, and credit-based/reputation-based schemes. Credit-based schemes use virtual currencies to provide incentives for nodes to forward packets, while reputation-based schemes track nodes' past behaviors. The document aims to survey approaches for mitigating the impact of misbehaving nodes in MANET routing.
A self recovery approach using halftone images for medical imageryiaemedu
This document summarizes a proposed approach for securely transferring medical images over the internet using visual cryptography and halftone images. The approach uses error diffusion techniques to generate a halftone host image from the grayscale medical image. Shadow images are then created from the halftone host image using visual cryptography algorithms. When stacked together, the shadow images reveal the secret medical image. The halftone host image also contains an embedded logo that can be extracted to verify the integrity of the reconstructed image without a trusted third party.
1) The document discusses the Cyclic Model Analysis (CMA) technique for sequential pattern mining which aims to predict customer purchasing behavior.
2) CMA calculates the Trend Distribution Function from sequential patterns to model purchasing trends over time. It then uses Generalized Periodicity Detection and Trend Modeling to identify periodic patterns and construct an approximating model.
3) The Cyclic Model Analysis algorithm is applied to further analyze the patterns, dividing the domain into segments where the distribution function is increasing or decreasing and applying the other techniques recursively to fully model the cyclic behavior.
The document discusses semantic web services and their challenges. It provides an overview of semantic web technologies like WSDL, SOAP, UDDI, and OIL which are used to build semantic web services. The semantic web architecture adds semantics to web services through ontologies written in OWL and DAML+OIL. Key approaches to semantic web services include annotation, composition, and addressing privacy and security. However, semantic web services still face challenges in achieving their full potential due to issues in representation, reasoning, and a lack of real-world applications and data.
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The document discusses the key elements of magazine front covers, including the masthead, tagline, central image, cover lines, and other visual components. The masthead captures the magazine's name and brand identity. The tagline adds depth and essence. The central image is meant to attract readers with celebrities or eye-catching photos. Cover lines and additional images promote internal articles concisely. Together these elements aim to entice audiences to purchase the magazine based on the cover alone.
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The document discusses new interpretive signs being installed at Lake Wabukayne, including a new lookout overlooking the lake and informational plaques providing details about the area. Tree planting is also mentioned as occurring.
This document provides a review of thermal energy storage, with a focus on phase change materials (PCMs). It begins by discussing different types of thermal energy storage, including sensible heat, latent heat, and thermochemical storage. Latent heat storage using PCMs is identified as particularly promising due to its high energy storage density. The document then reviews literature on various PCMs and composites that have been studied, including their properties. Challenges with PCMs like poor thermal conductivity and leakage are mentioned. The review identifies needs for more accurate material property data and improved thermal energy storage test rigs. It concludes by discussing research gaps and directions for future work, such as material durability testing and developing low-cost
Experimental investigation of a double slope solar still with a latentIAEME Publication
The document summarizes an experimental study on a double slope solar still with and without a latent heat storage medium. Zinc nitrate hexahydrate was used as the phase change material (PCM) in the still's basin. Key findings include:
- The double slope solar still with PCM observed a 33.5% increase in distillate collection compared to the still without PCM.
- PCMs like zinc nitrate hexahydrate can effectively store thermal energy during its phase change process, utilizing both sensible and latent heat.
- The study aims to improve the productivity of double slope solar stills for fresh water production by incorporating a PCM-based thermal energy storage system.
Experimental investigation of a double slope solar still with a latent heatiaemedu
This document summarizes an experimental investigation of a double slope solar still with a latent heat storage medium. Key findings include:
1) Adding zinc nitrate hexahydrate, a phase change material, to the still's basin increased total daily distillate output by 33.5% compared to the still without PCM.
2) The glass covers of the still with PCM maintained higher temperatures than without PCM, especially in the afternoon, due to the thermal inertia of the PCM tubes.
3) Hourly output measurements found 34.7% higher daytime production and 31.7% higher nocturnal production with the PCM, demonstrating its ability to continue providing thermal energy after sunset
Fabrication of new ceramics nanocomposites for solar energy storage and releasejournalBEEI
The carbides nanostructures have huge applications in renewable energy fields such as the saving of solar energy and release which attributed to the good their properties (thermal, electrical, mechanical, optical and chemical). So, in this paper, the solar energy storage and release of carbides nanoparticles/water for building heating and cooling applications have been investigated with different concentrations of metals carbides nanoparticles (tantalum carbide-silicon carbide). The results showed that the melting and solidification times for thermal energy storage and release decrease with an increase (TaC-SiC) nanoparticles concentrations. From the obtained results, the TaC/SiC nanostructures/ water nano-system are considered as promising materials for solar energy storage and release with high efficiency and high gain (more than 50% compare with the water). Also, the TaC/SiC may be used for heating and cooling fields with good performance and high gain.
This document reviews developments in organic solid-liquid phase change materials (PCMs) and their applications in thermal energy storage. It discusses three main aspects: materials, encapsulation, and applications of organic PCMs. Organic PCMs have benefits like congruent melting and narrow melting/freezing temperature ranges, but also have low thermal conductivity. The document explores techniques to enhance thermal conductivity and discusses applications of organic PCMs in areas like buildings, electronics, refrigeration, and solar energy. It is noted that organic PCMs are widely used in applications with low to medium temperature requirements but less common in high temperature applications.
Enhancement of Latent Heat Thermal Energy Storage using Embedded Heat PipeIRJET Journal
This document discusses using heat pipes to enhance latent heat thermal energy storage. Heat pipes can increase heat transfer rates in latent heat thermal energy storage systems by reducing thermal resistance in phase change materials. The document presents an experiment that validates using heat pipes in latent heat thermal energy storage to lower thermal resistance. It also models a large-scale latent heat thermal energy storage system with gravity-assisted heat pipes and conducts a cost analysis. The results show that including heat pipes can increase phase change material melting rates by around 60% compared to configurations without heat pipes.
REVIEW OF THERMAL ENERGY STORAGE SYSTEMS AND THEIR APPLICATIONSijiert bestjournal
Nowadays,the worldwide worry about a global climat e change pushes to develop new energetic strategies. And more,after the recent energetic cr isis due to the increase of oil price,or the gas crisis arisen between Russia and Ukraine This paper reviews the Thermal energy storage systems which have the potential for increasing the effecti ve use of thermal energy equipment and for facilitating large-scale switching. They are normal ly useful for correcting the mismatch between the supply and demand of energy. There are different me thods in thermal storage systems.
IRJET- Analysis of the Heat Transfer During Energy Storage in a Triplex Conce...IRJET Journal
This document analyzes heat transfer during energy storage in a triplex concentric tube using a phase change material (PCM). It discusses modeling the triplex concentric tube in Creo 2.0 and simulating heat transfer using computational fluid dynamics (CFD) in ANSYS. The study examines the impact of water temperature and heat transfer fluid flow on thermal energy storage. It analyzes heat transfer coefficient, heat transfer rate, and skin friction coefficient under different conditions. The main objective is to evaluate heat transfer during the charging and discharging processes of the PCM thermal energy storage unit.
IRJET- Design and Fabrication of Thermo Acoustic RefrigeratorIRJET Journal
This document describes the design and fabrication of a thermoacoustic refrigerator. Some key points:
1. Thermoacoustic refrigeration uses sound waves to alternately compress and relax gas particles in a tube, transferring heat without moving parts.
2. The refrigerator consists of a resonator tube containing a stack of closely spaced surfaces through which a sound wave oscillates. Heat is transferred between the gas and stack surfaces.
3. Experiments investigated different stack geometries and materials to optimize heat transfer and the refrigerator's performance. Temperature sensors measured the temperature difference created.
Waste Heat Recovery From Refrigeration PlantIRJET Journal
This document summarizes waste heat recovery from a refrigeration plant condenser. It discusses how the waste heat from a condenser, which is currently released into the environment, can instead be captured and used for applications like water heating. The document then provides technical details on heat transfer methods, refrigerants, and vapor compression refrigeration systems. It analyzes using the condenser waste heat from a 30-ton refrigeration plant to heat water up to 50°C, which could then be used for low-temperature household or industrial purposes. Capturing this waste heat improves overall system efficiency and reduces environmental impacts.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on using a Fresnel lens to concentrate solar rays and transfer heat to a phase change material (paraffin wax) for thermal energy storage. The integrated collector storage system was experimentally tested for charging and discharging performance. Results showed the paraffin wax was able to store heat in the 50-65°C range suitable for domestic hot water applications. During discharge, different heat transfer fluid tube configurations were tested and a multiple pass design provided faster thermal response times but a steeper temperature drop compared to a single pass design. In conclusion, paraffin wax was found to be a promising phase change material for low temperature thermal energy storage applications.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on using a Fresnel lens to concentrate solar rays and transfer heat to a phase change material (paraffin wax) for thermal energy storage. The study tested different configurations of heat transfer tubes for charging and discharging the storage system to provide domestic hot water. Testing showed the paraffin wax was able to store heat in the 50-65°C range needed for hot water. Multiple pass heat transfer tubes provided faster thermal response during discharge but with a steeper temperature drop compared to single pass tubes. The Fresnel lens was able to efficiently charge the storage system during peak solar hours to provide hot water during non-solar periods.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on a solar integrated collector storage system using a Fresnel lens for domestic hot water applications. The system uses paraffin wax as a phase change material (PCM) for thermal energy storage. Experimental results showed that the PCM was able to store sufficient thermal energy from the sun concentrated by the Fresnel lens to maintain water temperatures around 50-60°C for hot water needs for over 50 minutes without direct sunlight. Graphs of temperature over time demonstrated stable water outlet temperatures during discharge of the stored thermal energy after charging by concentrated solar radiation. The study confirms the technical feasibility of using a Fresnel lens and paraffin wax PCM for an efficient solar thermal energy storage system for
Studies on Impact of Phase Changing Material on Concrete for Enhancing Therma...IRJET Journal
This document discusses a study on the impact of incorporating phase change materials (PCMs) into concrete to enhance thermal comfort. The study tested concrete mixtures with different percentages of paraffin wax PCM (0%, 10%, 20%, 30%) to evaluate compressive strength and temperature regulation properties. The key findings were:
1) Compressive strength was minimally reduced with 10% PCM replacement but decreased more significantly at higher replacement levels.
2) Concrete cubes coated with a PCM-enhanced plaster maintained a more constant internal temperature when exposed to sunlight compared to untreated cubes.
3) Thermal conductivity of concrete decreased with increasing PCM content, indicating improved thermal insulating properties.
Review on Design and Theoretical Model of Thermoelectricijsrd.com
This paper presents the theoretical development of the equations that allow to evaluate the performance of an air conditioning system based on the thermoelectric effect. The cooling system is based on a phenomena discovered by Jean Charles Athanase Peltier, in 1834. According to this when electricity runs through a junction between two semiconductors with different properties, heat is dissipated or absorbed. Thus, thermoelectric modules are made by semiconductors materials sealed between two plates through which a continuous current flows and keeps one plate hot and the other cold. The most important parameters to evaluate the performance of the device thermoelectric refrigeration are the coefficient of performance, the heat pumping rate and the maximum temperature difference between the hot side and the cold side of the thermoelectric module.
The document describes experimental studies of two cylindrical latent heat energy storage systems (LHESS) using lauric acid as the phase change material (PCM). The first is a horizontal cylinder with one finned copper pipe passing through the center. The second is a vertical cylinder with two finned copper pipes allowing for simultaneous charging and discharging. Experiments were conducted to study the phase change behavior of the PCM and heat transfer processes during charging, discharging, and simultaneous charging/discharging. Results show natural convection plays an important role in melting and simultaneous charging/discharging but less so in solidification.
IRJET- Critical Analysis of Thermoelectric Cycle (Tri-Cycle)IRJET Journal
1) The document describes the critical analysis of a thermoelectric air conditioning system called a tri-cycle that can provide comfortable transport and delivery of goods.
2) It uses thermoelectric modules instead of harmful refrigerants like ammonia or CFCs that pollute the atmosphere and damage the ozone layer.
3) The thermoelectric air conditioning system has advantages over conventional systems like being compact, lightweight, having no moving parts so it does not wear out or leak refrigerants.
IRJET- Nano Enhanced Phase Change Material for Thermal Energy Storage App...IRJET Journal
This document discusses using nano-enhanced phase change materials (PCMs) for thermal energy storage. Specifically, it analyzes adding alumina nanoparticles to paraffin wax to increase its thermal conductivity and storage capacity. The results show that a composite of paraffin wax and alumina nanoparticles has improved thermal storage performance compared to paraffin wax alone in a shell and tube heat exchanger. Adding nanoparticles is an effective way to enhance the thermal properties and performance of PCMs for thermal energy storage applications.
Review on Thermoelectric materials and applicationsijsrd.com
In this paper thermoelectric materials are theoretically analyzed. The thermoelectric cooler device proposed here uses semiconductor material and uses current to transport energy (i.e., heat) from a cold source to a hot source via n- and p-type carriers. This device is fabricated by combining the standard n- and p-channel solid-state thermoelectric cooler with a two-element device inserted into each of the two channels to eliminate the solid-state thermal conductivity. The heat removed from the cold source is the energy difference, because of field emitted electrons from the n-type and p-type semiconductors. The cooling efficiency is operationally defined as where V is the anode bias voltage The cooling device here is shown to have an energy transport (i.e., heat) per electron of about500 me V depending on concentration and field while, in good thermoelectric coolers, it is about 50-60 me V at room temperature.
Numerical and Experimental investigation of packed bed thermal energy storage...IRJET Journal
This document presents a numerical investigation of a packed bed thermal energy storage system using Al2O3 nanofluids. The storage material consists of tightly packed glass beads and pebbles. A two-phase one-dimensional model is used to analyze the temperature distribution over time within the storage system during charging. The enhancement ratio and advantage ratio of the storage system are calculated using nanofluids and compared to using water. The objective is to analyze the performance benefits of using nanofluids in packed bed thermal energy storage.
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Tech transfer making it as a risk free approach in pharmaceutical and biotech iniaemedu
Tech transfer is a common methodology for transferring new products or an existing
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The document discusses agile programming and proposes a new methodology. It provides an overview of existing agile methodologies like Scrum and Extreme Programming. Scrum uses short sprints to define tasks and deadlines. Extreme Programming focuses on practices like test-first development, pair programming, and continuous integration. The document notes drawbacks like an inability to support large or multi-site projects. It proposes designing a new methodology that combines the advantages of existing methods while overcoming their deficiencies.
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