This document discusses three methods of refrigeration: thermoelectric refrigeration using the Peltier effect, vortex tube refrigeration using compressed air, and cooling by adiabatic demagnetization. Thermoelectric refrigeration uses the temperature difference created when applying a voltage to semiconductor materials to pump heat. Vortex tube refrigeration separates compressed air flows to produce hot and cold air without moving parts. Cooling by adiabatic demagnetization exploits the magnetocaloric effect where exposing magnetic materials to changing magnetic fields causes temperature changes, allowing cooling below absolute zero temporarily. Examples of each method and their advantages/disadvantages are provided.
The document summarizes a student mini project on developing a thermoelectric air conditioning system. The system uses a thermoelectric Peltier module based on the Peltier effect to provide cooling without moving parts. It consists of a 12V Peltier device sandwiched between two heat sinks to dissipate heat, powered by a 12V battery. Fans are used to aid heat transfer. The document discusses thermoelectric principles, components used including specifications, assembly, advantages and limitations. The system was able to lower temperature by 2.11°C with a coefficient of performance of 0.8064 for cooling.
This document summarizes a student project report on designing a mini compressor-less Peltier refrigerator. It begins with acknowledgements to the student's project guide and department head for their support and guidance. It then provides a project certificate signed by the internal and external guides. The document outlines the objectives of studying Peltier cooling technology and designing a refrigerator. It describes the materials used, including an aluminum evaporator box and a 12V water pump for cooling the hot side of the Peltier module. The remaining chapters will cover the refrigerator's construction, working principle, cost analysis, and conclusions.
Solid cooling and heating with help of peltier plate by using solar energy with the help of a micro controller. The cop of this refrigeration effect is always less than 1 because we in intake low grade thermal energy.
Estimation of cooling requirement of magnets in the multi cusp plasma deviceeSAT Journals
Abstract The need for energy generation from clean sources like nuclear fusion has given rise to increased research in the Plasma and its characteristic properties. Multi-cusp Plasma Device installed at the IPR is one of the device used to study the plasma characteristics wherein quiescent plasma is generated. An optimized design of water cooling system is necessary to ensure the removal of heat losses and keep the electromagnets of the plasma device under the safe operating conditions of temperature and thermal stresses by passage of flow of water, thereby increasing the life cycle of the device. The project focuses on the fluid flow analysis for the heat transfer of generated heat in the magnet due to the continuous supply of electricity. The aim of this project is to determine the performance and working attributes of the cooling system used. The design and evaluation of the cooling system are executed on the basis of analytical calculations and actual experimentation work on the device. Key Words: Chiller requirement, cooling requirement, electromagnet cooling, fluid flow analysis, Multi-cusp plasma device, pressure drop, pump requirement, water cooling
Solar Energy based Refrigeration System using Peltier Device 18 ABHISHEK.pdfkeshavkumar403723
This document summarizes a research paper on a solar energy-based refrigeration system using Peltier devices. The system utilizes solar energy to power thermoelectric modules that provide refrigeration without the need for refrigerants or mechanical devices like compressors. The system is intended to provide refrigeration to remote areas without reliable power sources. It describes the construction of the refrigeration system, including the thermoelectric module, refrigeration chamber, battery, solar cells, and frame. It also provides background on thermoelectric effects like the Peltier effect that allow the system to operate.
Electric heating has several advantages over other heating systems, including cleanliness, ease of control, and higher efficiency. There are three main modes of heat transfer: conduction through solids, convection in liquids and gases, and radiation through empty space. Electric heating works through either direct resistance heating by passing current through a material, or indirect heating where a resistive element transfers heat via convection or radiation. Electric arc heating produces very high temperatures by generating an electric arc between electrodes, and is used in electric arc furnaces for melting metals.
Fabrication of Thermo Electric Solar Fridgeiosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
The document summarizes a student mini project on developing a thermoelectric air conditioning system. The system uses a thermoelectric Peltier module based on the Peltier effect to provide cooling without moving parts. It consists of a 12V Peltier device sandwiched between two heat sinks to dissipate heat, powered by a 12V battery. Fans are used to aid heat transfer. The document discusses thermoelectric principles, components used including specifications, assembly, advantages and limitations. The system was able to lower temperature by 2.11°C with a coefficient of performance of 0.8064 for cooling.
This document summarizes a student project report on designing a mini compressor-less Peltier refrigerator. It begins with acknowledgements to the student's project guide and department head for their support and guidance. It then provides a project certificate signed by the internal and external guides. The document outlines the objectives of studying Peltier cooling technology and designing a refrigerator. It describes the materials used, including an aluminum evaporator box and a 12V water pump for cooling the hot side of the Peltier module. The remaining chapters will cover the refrigerator's construction, working principle, cost analysis, and conclusions.
Solid cooling and heating with help of peltier plate by using solar energy with the help of a micro controller. The cop of this refrigeration effect is always less than 1 because we in intake low grade thermal energy.
Estimation of cooling requirement of magnets in the multi cusp plasma deviceeSAT Journals
Abstract The need for energy generation from clean sources like nuclear fusion has given rise to increased research in the Plasma and its characteristic properties. Multi-cusp Plasma Device installed at the IPR is one of the device used to study the plasma characteristics wherein quiescent plasma is generated. An optimized design of water cooling system is necessary to ensure the removal of heat losses and keep the electromagnets of the plasma device under the safe operating conditions of temperature and thermal stresses by passage of flow of water, thereby increasing the life cycle of the device. The project focuses on the fluid flow analysis for the heat transfer of generated heat in the magnet due to the continuous supply of electricity. The aim of this project is to determine the performance and working attributes of the cooling system used. The design and evaluation of the cooling system are executed on the basis of analytical calculations and actual experimentation work on the device. Key Words: Chiller requirement, cooling requirement, electromagnet cooling, fluid flow analysis, Multi-cusp plasma device, pressure drop, pump requirement, water cooling
Solar Energy based Refrigeration System using Peltier Device 18 ABHISHEK.pdfkeshavkumar403723
This document summarizes a research paper on a solar energy-based refrigeration system using Peltier devices. The system utilizes solar energy to power thermoelectric modules that provide refrigeration without the need for refrigerants or mechanical devices like compressors. The system is intended to provide refrigeration to remote areas without reliable power sources. It describes the construction of the refrigeration system, including the thermoelectric module, refrigeration chamber, battery, solar cells, and frame. It also provides background on thermoelectric effects like the Peltier effect that allow the system to operate.
Electric heating has several advantages over other heating systems, including cleanliness, ease of control, and higher efficiency. There are three main modes of heat transfer: conduction through solids, convection in liquids and gases, and radiation through empty space. Electric heating works through either direct resistance heating by passing current through a material, or indirect heating where a resistive element transfers heat via convection or radiation. Electric arc heating produces very high temperatures by generating an electric arc between electrodes, and is used in electric arc furnaces for melting metals.
Fabrication of Thermo Electric Solar Fridgeiosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document describes the fabrication of a thermoelectric solar fridge. It contains the following key points:
1. A thermoelectric module uses the Seebeck and Peltier effects to generate electrical power from a temperature gradient or convert electrical energy into a temperature gradient for cooling. A solar panel charges a battery through photovoltaic effect, and the battery powers the thermoelectric module.
2. The thermoelectric module is composed of P-type and N-type semiconductors, usually bismuth telluride, between ceramic substrates. When current passes through, it absorbs heat on one side and releases heat on the other, allowing one side to be used for cooling.
This document describes the fabrication of a thermoelectric solar fridge. It contains the following key points:
1. A thermoelectric module uses the Seebeck and Peltier effects to generate electrical power from a temperature gradient or convert electrical energy into a temperature gradient for cooling. A solar panel charges a battery through photovoltaic effect, and the battery powers the thermoelectric module.
2. The thermoelectric module is composed of P-type and N-type semiconductors, usually bismuth telluride, between ceramic substrates. When current passes through, it absorbs heat on one side and releases heat on the other, allowing one side to be used for cooling.
This document provides an overview of thermoelectric cooling, including:
- Why thermoelectric coolers are used for applications requiring precise temperature control and no moving parts.
- The basic principles of the Peltier effect and semiconductor doping to create N-type and P-type materials.
- Key factors that determine thermoelectric performance like thermal and electrical conductivity.
- Common thermoelectric materials like Bi2Te3 and design considerations and methods.
- Applications of thermoelectric cooling in electronics, medical, aerospace and other industries.
Thermoelectric coolers use the Peltier effect to provide precise temperature control without moving parts. They are commonly used for electronics cooling, though their efficiency is lower than vapor compression systems. Design considerations include semiconductor type and materials, thermal insulation, heat sinks, and multistage configurations to improve performance. Optimization aims to maximize heat pumping capacity within voltage and temperature constraints.
This document summarizes a seminar presentation on thermoelectric cooling systems. It introduces thermoelectric coolers and their basic principles, including the Peltier effect whereby applying a voltage creates a heat pump effect. Common materials used are bismuth telluride semiconductors. Multistage cooler designs can improve performance by decreasing the minimum cold side temperature. Thermoelectric coolers have advantages over vapor compression systems like no moving parts, quick response time, and lower power usage. Applications include electronics cooling, refrigeration, medical and laboratory equipment.
Direct energy conversion (DEC) converts a charged particle's kinetic energy directly into electricity. It can be used to extract power from nuclear fusion. One DEC method is magnetohydrodynamic (MHD) power generation, which uses a conducting fluid moving at high speed through a magnetic field to generate electricity via Faraday's law of induction. MHD generators operate at very high temperatures, using ionized gas as the working fluid moving between electrode plates under pressure and magnetic field conditions sufficient to overcome magnetic forces and induce a current.
Ece Final Report for-"Various Types of electrical and electronic equipments a...Ninder Joshi
This document provides information on electrical and electronic devices. Electrical devices use or generate electricity to produce effects like heat or light, while electronic devices contain components that control electric currents and voltages. Examples of electrical devices include ceiling fans and toasters, while electronic devices include smartphones and cameras. The document also discusses the differences between electrical and electronic devices and provides details on common household devices like ceiling fans, refrigerators, irons, microphones, and toasters, explaining their basic workings.
Testing and Validation of Thermoelectric CoolersIJERA Editor
The first Air conditioners and refrigerators employed toxic or flammable gases such as Chloro Fluoro Carbons (CFC’s), Hydro Chloro Fluorocarbons (HCFC’s), Hydro Fluoro Carbons (HFC’s) and ammonia that could result in fatal accidents when they leaked into the atmosphere. In an automobile, the AC system increases fuel consumption of the vehicle, which uses around 4HP (i.e. 3 kW) of the engine's power. Most refrigerants used for AC system contribute to global warming, and may also destroy the ozone layer. CFC’s, HCFC’s, and HFC’s are poisonous greenhouse gases when they are leaked to the atmosphere and 100 gm of HFC’s destroy 0.5 tons of O3 molecules. In recent years, demand for small size active cooling equipment has increased which includes TEC and water cooled heat sink. While on the other hand the passive cooling system includes heat sink and fan which is not effective enough to cope with task of cooling various electronic components. The active cooling system using TEC can be used where precise control of temperature is required. The energy conversion process which is carried out by active cooling system to absorb the heat from the surface to be cooled and reject that heat to the surrounding. Our project objective is testing and validation of TEC1-12706 and evaluating its capacity, limitations and performance to be used to produce cooling effect in R&AC system. Authors are presenting performance curve enabling the user to design the optimum number of thermoelectric module (TEM) for any required cooling system. In order to find out the capacity of single TEC we have made a prototype in which the existing refrigerants are replaced by newly emerging TEC which works on Peltier effect in AC system. TEC can be used as a generator to generate electricity by applying reverse engineering.
Thermoelectric Refrigeration System Running On Solar Energypaperpublications3
Abstract: The global increasing demand for refrigeration in field of refrigeration, food preservation, storages, medical services, and cooling of electronic devices, led to production of more electricity and consequently more release of CO2 all over the world which it is contributing factor of global warming on climate change. With the increase awareness towards environmental degradation due to the production, use and disposal of Chloro Fluoro Carbons (CFCs) and Hydro Chlorofluorocarbons (HCFCs) as heat carrier fluids in conventional refrigeration and air conditioning systems. Thermoelectric refrigeration is new alternative because it can convert waste electricity into useful cooling, is expected to play an important role in today's energy challenges. It does not require working fluids or any moving parts, which is friendly to the environment and it simply uses electrons rather than refrigerants as a heat carrier. Continuous efforts are given by researchers for development of thermo electric materials with increase figure of merit may provide a potential commercial use of thermoelectric refrigeration system.
In this work it has been identified that there is enormous scope to develop TER system running on solar energy and its performance evaluation along with mathematical modeling. Mathematical results can be correlate by performing experimental test set up. Present paper especially focuses on evaluation of numbers of thermoelectric cooling module; heat sink fan assembly for each module which is used to increase heat dissipation rate and time required for attaining the cooling of heat sink fan assembly after a solar power is applied.
Thermoelectric cooling for industrial enclosureserdinc klima
This white paper discusses the advantages of thermoelectric cooling compared to conventional cooling methods for industrial enclosures. Thermoelectric coolers use the Peltier effect to generate cooling by passing an electric current through semiconductors, eliminating the need for refrigerants or water cooling systems. Recent improvements have increased thermoelectric cooler efficiency up to 400% by using techniques like pulse width modulation. Thermoelectric coolers provide benefits like fewer moving parts for less noise and vibration, flexibility in installation orientation and location, and solid-state operation requiring only electricity. The paper concludes that thermoelectric cooling is emerging as a viable option for certain small-to-medium enclosure applications.
Performance Evaluation of Thermoelectric Materials: A Case Study of Orthorhom...inventionjournals
Designers often face the predicament of non-standardized and poor performing materials for thermoelectric module manufacturing. Other than analytical means, the only method to evaluate the performance of thermoelectric materials would be through experimental means. This work studies the experimental approach employed in performance investigation of thermoelectric materials using Orthorhombic SnSe crystals as a case study. The result obtained reveals the high thermoelectric conversion efficiency of orthorhombic crystals, and that they can operate as both low and high temperature thermoelectric material.
The present trend in the electronic packaging industry is to reduce the size and increase the performance of the equipment. As the power of these systems increases and the volume allowed diminishes, heat flux or density is spiraled. The cooling of modern electronic components is one of the prime areas for the application of thermal control techniques. Of the many thermal-cooling techniques, forced air-cooling being one such extensively used technique due to its simple design and easy availability of air. The present study is to design an air cooled high power electronic system to dissipate heat from selected electronic components.
1) Induction heating uses a high frequency alternating current in a coil to generate a magnetic field, inducing eddy currents in a conductive material placed within the coil. This heats the material through resistance without direct contact.
2) Common applications include sealing bottle caps, getter firing in vacuum tubes, and zone purification in semiconductor manufacturing.
3) An induction heating system requires a high frequency power source, a work coil to generate the magnetic field, and a conductive workpiece to be heated through eddy currents.
The magnetic refrigeration at room temperature is an emerging technology that has
attracted the interest of researchers around the world (Bouchekara, 2008). Such a technology
applies the magnetocaloric effect which was first discovered by Warburg (Bohigas, 2000;
Zimm, 2007).
This document presents information about heat transfer by room heaters from a group project. It introduces heat transfer and the three main modes: conduction, convection, and radiation. It then explains the principles of heat transfer in heaters. Electric heaters work by using an electrical resistor that converts electric current into heat energy. Radiant heaters use heating elements that reach a high temperature and emit infrared radiation to directly warm objects. Convection heaters heat the surrounding air, which rises and circulates to spread the warmth.
The document discusses thermoelectric cooling, which uses the Peltier effect to create a heat pump-like cooling system without moving parts. It operates by passing a current through two dissimilar conductors joined at two points maintained at different temperatures. When current is applied, heat is absorbed at one junction and expelled at the other, allowing one side to be cooled. Thermoelectric coolers use semiconductors like bismuth telluride in a series of p-n junctions to transfer heat from one side to the other in response to an applied current, providing solid-state cooling without liquids or gases.
boosting energy of solar panel using heat pipesIJCMESJOURNAL
A novel micro heat pipe array was used in solar panel cooling system, both under air-cooled and water cooled mediums, under natural convection. As compared with a ordinary solar panel (without heat pipe arrangement). The result had considerable variation in the efficiency of the energy output, it improved with the help of heat pipe installation. Therefore using a heat pipe gradually improved the efficiency by reducing the heat by cooling the system.
Thermoelectric and thermionic devices convert heat directly into electricity using solid-state phenomena.
Thermoelectric devices rely on the Seebeck effect where a temperature gradient across conductive materials produces an electric current. Common thermoelectric materials include bismuth telluride, lead telluride, and silicon-germanium alloys.
Thermionic converters boil electrons from a hot cathode across a vacuum gap to a cooler anode surface. Cesium gas filling can improve efficiency but introduces sealing and corrosion challenges.
Combining thermionic and thermoelectric principles could leverage the higher efficiency of thermionic devices with thermoelectric devices' ability to utilize lower temperature heat sources.
The document compares the experimental performance of a thermoelectric refrigerator to a vapor compression refrigerator. It finds that for 325 ml of water cooled from 32°C to below 6°C:
- In the commercial refrigerator's freezer compartment, the water temperature decreased linearly with time, taking 61 minutes to reach 6°C.
- In the thermoelectric refrigerator, the water temperature decreased exponentially with time, taking 69 minutes to reach 6°C.
- For most of the cooling time, the thermoelectric refrigerator cooled at a faster rate than the commercial refrigerator.
Direct energy conversion involves transforming one form of energy directly into another without intermediate steps. This summary will discuss three methods of direct energy conversion:
1) Thermoelectric generators directly convert heat into electricity through the Seebeck effect using semiconductors. They have no moving parts and can operate with a simple design of p-type and n-type materials.
2) Fuel cells also directly produce electricity from chemical reactions without combustion, like the Grove fuel cell developed in 1839.
3) Thermoelectric photovoltaic cells directly convert sunlight into electricity through the photovoltaic effect in semiconductor junctions.
This document describes the fabrication of a thermoelectric solar fridge. It contains the following key points:
1. A thermoelectric module uses the Seebeck and Peltier effects to generate electrical power from a temperature gradient or convert electrical energy into a temperature gradient for cooling. A solar panel charges a battery through photovoltaic effect, and the battery powers the thermoelectric module.
2. The thermoelectric module is composed of P-type and N-type semiconductors, usually bismuth telluride, between ceramic substrates. When current passes through, it absorbs heat on one side and releases heat on the other, allowing one side to be used for cooling.
This document describes the fabrication of a thermoelectric solar fridge. It contains the following key points:
1. A thermoelectric module uses the Seebeck and Peltier effects to generate electrical power from a temperature gradient or convert electrical energy into a temperature gradient for cooling. A solar panel charges a battery through photovoltaic effect, and the battery powers the thermoelectric module.
2. The thermoelectric module is composed of P-type and N-type semiconductors, usually bismuth telluride, between ceramic substrates. When current passes through, it absorbs heat on one side and releases heat on the other, allowing one side to be used for cooling.
This document provides an overview of thermoelectric cooling, including:
- Why thermoelectric coolers are used for applications requiring precise temperature control and no moving parts.
- The basic principles of the Peltier effect and semiconductor doping to create N-type and P-type materials.
- Key factors that determine thermoelectric performance like thermal and electrical conductivity.
- Common thermoelectric materials like Bi2Te3 and design considerations and methods.
- Applications of thermoelectric cooling in electronics, medical, aerospace and other industries.
Thermoelectric coolers use the Peltier effect to provide precise temperature control without moving parts. They are commonly used for electronics cooling, though their efficiency is lower than vapor compression systems. Design considerations include semiconductor type and materials, thermal insulation, heat sinks, and multistage configurations to improve performance. Optimization aims to maximize heat pumping capacity within voltage and temperature constraints.
This document summarizes a seminar presentation on thermoelectric cooling systems. It introduces thermoelectric coolers and their basic principles, including the Peltier effect whereby applying a voltage creates a heat pump effect. Common materials used are bismuth telluride semiconductors. Multistage cooler designs can improve performance by decreasing the minimum cold side temperature. Thermoelectric coolers have advantages over vapor compression systems like no moving parts, quick response time, and lower power usage. Applications include electronics cooling, refrigeration, medical and laboratory equipment.
Direct energy conversion (DEC) converts a charged particle's kinetic energy directly into electricity. It can be used to extract power from nuclear fusion. One DEC method is magnetohydrodynamic (MHD) power generation, which uses a conducting fluid moving at high speed through a magnetic field to generate electricity via Faraday's law of induction. MHD generators operate at very high temperatures, using ionized gas as the working fluid moving between electrode plates under pressure and magnetic field conditions sufficient to overcome magnetic forces and induce a current.
Ece Final Report for-"Various Types of electrical and electronic equipments a...Ninder Joshi
This document provides information on electrical and electronic devices. Electrical devices use or generate electricity to produce effects like heat or light, while electronic devices contain components that control electric currents and voltages. Examples of electrical devices include ceiling fans and toasters, while electronic devices include smartphones and cameras. The document also discusses the differences between electrical and electronic devices and provides details on common household devices like ceiling fans, refrigerators, irons, microphones, and toasters, explaining their basic workings.
Testing and Validation of Thermoelectric CoolersIJERA Editor
The first Air conditioners and refrigerators employed toxic or flammable gases such as Chloro Fluoro Carbons (CFC’s), Hydro Chloro Fluorocarbons (HCFC’s), Hydro Fluoro Carbons (HFC’s) and ammonia that could result in fatal accidents when they leaked into the atmosphere. In an automobile, the AC system increases fuel consumption of the vehicle, which uses around 4HP (i.e. 3 kW) of the engine's power. Most refrigerants used for AC system contribute to global warming, and may also destroy the ozone layer. CFC’s, HCFC’s, and HFC’s are poisonous greenhouse gases when they are leaked to the atmosphere and 100 gm of HFC’s destroy 0.5 tons of O3 molecules. In recent years, demand for small size active cooling equipment has increased which includes TEC and water cooled heat sink. While on the other hand the passive cooling system includes heat sink and fan which is not effective enough to cope with task of cooling various electronic components. The active cooling system using TEC can be used where precise control of temperature is required. The energy conversion process which is carried out by active cooling system to absorb the heat from the surface to be cooled and reject that heat to the surrounding. Our project objective is testing and validation of TEC1-12706 and evaluating its capacity, limitations and performance to be used to produce cooling effect in R&AC system. Authors are presenting performance curve enabling the user to design the optimum number of thermoelectric module (TEM) for any required cooling system. In order to find out the capacity of single TEC we have made a prototype in which the existing refrigerants are replaced by newly emerging TEC which works on Peltier effect in AC system. TEC can be used as a generator to generate electricity by applying reverse engineering.
Thermoelectric Refrigeration System Running On Solar Energypaperpublications3
Abstract: The global increasing demand for refrigeration in field of refrigeration, food preservation, storages, medical services, and cooling of electronic devices, led to production of more electricity and consequently more release of CO2 all over the world which it is contributing factor of global warming on climate change. With the increase awareness towards environmental degradation due to the production, use and disposal of Chloro Fluoro Carbons (CFCs) and Hydro Chlorofluorocarbons (HCFCs) as heat carrier fluids in conventional refrigeration and air conditioning systems. Thermoelectric refrigeration is new alternative because it can convert waste electricity into useful cooling, is expected to play an important role in today's energy challenges. It does not require working fluids or any moving parts, which is friendly to the environment and it simply uses electrons rather than refrigerants as a heat carrier. Continuous efforts are given by researchers for development of thermo electric materials with increase figure of merit may provide a potential commercial use of thermoelectric refrigeration system.
In this work it has been identified that there is enormous scope to develop TER system running on solar energy and its performance evaluation along with mathematical modeling. Mathematical results can be correlate by performing experimental test set up. Present paper especially focuses on evaluation of numbers of thermoelectric cooling module; heat sink fan assembly for each module which is used to increase heat dissipation rate and time required for attaining the cooling of heat sink fan assembly after a solar power is applied.
Thermoelectric cooling for industrial enclosureserdinc klima
This white paper discusses the advantages of thermoelectric cooling compared to conventional cooling methods for industrial enclosures. Thermoelectric coolers use the Peltier effect to generate cooling by passing an electric current through semiconductors, eliminating the need for refrigerants or water cooling systems. Recent improvements have increased thermoelectric cooler efficiency up to 400% by using techniques like pulse width modulation. Thermoelectric coolers provide benefits like fewer moving parts for less noise and vibration, flexibility in installation orientation and location, and solid-state operation requiring only electricity. The paper concludes that thermoelectric cooling is emerging as a viable option for certain small-to-medium enclosure applications.
Performance Evaluation of Thermoelectric Materials: A Case Study of Orthorhom...inventionjournals
Designers often face the predicament of non-standardized and poor performing materials for thermoelectric module manufacturing. Other than analytical means, the only method to evaluate the performance of thermoelectric materials would be through experimental means. This work studies the experimental approach employed in performance investigation of thermoelectric materials using Orthorhombic SnSe crystals as a case study. The result obtained reveals the high thermoelectric conversion efficiency of orthorhombic crystals, and that they can operate as both low and high temperature thermoelectric material.
The present trend in the electronic packaging industry is to reduce the size and increase the performance of the equipment. As the power of these systems increases and the volume allowed diminishes, heat flux or density is spiraled. The cooling of modern electronic components is one of the prime areas for the application of thermal control techniques. Of the many thermal-cooling techniques, forced air-cooling being one such extensively used technique due to its simple design and easy availability of air. The present study is to design an air cooled high power electronic system to dissipate heat from selected electronic components.
1) Induction heating uses a high frequency alternating current in a coil to generate a magnetic field, inducing eddy currents in a conductive material placed within the coil. This heats the material through resistance without direct contact.
2) Common applications include sealing bottle caps, getter firing in vacuum tubes, and zone purification in semiconductor manufacturing.
3) An induction heating system requires a high frequency power source, a work coil to generate the magnetic field, and a conductive workpiece to be heated through eddy currents.
The magnetic refrigeration at room temperature is an emerging technology that has
attracted the interest of researchers around the world (Bouchekara, 2008). Such a technology
applies the magnetocaloric effect which was first discovered by Warburg (Bohigas, 2000;
Zimm, 2007).
This document presents information about heat transfer by room heaters from a group project. It introduces heat transfer and the three main modes: conduction, convection, and radiation. It then explains the principles of heat transfer in heaters. Electric heaters work by using an electrical resistor that converts electric current into heat energy. Radiant heaters use heating elements that reach a high temperature and emit infrared radiation to directly warm objects. Convection heaters heat the surrounding air, which rises and circulates to spread the warmth.
The document discusses thermoelectric cooling, which uses the Peltier effect to create a heat pump-like cooling system without moving parts. It operates by passing a current through two dissimilar conductors joined at two points maintained at different temperatures. When current is applied, heat is absorbed at one junction and expelled at the other, allowing one side to be cooled. Thermoelectric coolers use semiconductors like bismuth telluride in a series of p-n junctions to transfer heat from one side to the other in response to an applied current, providing solid-state cooling without liquids or gases.
boosting energy of solar panel using heat pipesIJCMESJOURNAL
A novel micro heat pipe array was used in solar panel cooling system, both under air-cooled and water cooled mediums, under natural convection. As compared with a ordinary solar panel (without heat pipe arrangement). The result had considerable variation in the efficiency of the energy output, it improved with the help of heat pipe installation. Therefore using a heat pipe gradually improved the efficiency by reducing the heat by cooling the system.
Thermoelectric and thermionic devices convert heat directly into electricity using solid-state phenomena.
Thermoelectric devices rely on the Seebeck effect where a temperature gradient across conductive materials produces an electric current. Common thermoelectric materials include bismuth telluride, lead telluride, and silicon-germanium alloys.
Thermionic converters boil electrons from a hot cathode across a vacuum gap to a cooler anode surface. Cesium gas filling can improve efficiency but introduces sealing and corrosion challenges.
Combining thermionic and thermoelectric principles could leverage the higher efficiency of thermionic devices with thermoelectric devices' ability to utilize lower temperature heat sources.
The document compares the experimental performance of a thermoelectric refrigerator to a vapor compression refrigerator. It finds that for 325 ml of water cooled from 32°C to below 6°C:
- In the commercial refrigerator's freezer compartment, the water temperature decreased linearly with time, taking 61 minutes to reach 6°C.
- In the thermoelectric refrigerator, the water temperature decreased exponentially with time, taking 69 minutes to reach 6°C.
- For most of the cooling time, the thermoelectric refrigerator cooled at a faster rate than the commercial refrigerator.
Direct energy conversion involves transforming one form of energy directly into another without intermediate steps. This summary will discuss three methods of direct energy conversion:
1) Thermoelectric generators directly convert heat into electricity through the Seebeck effect using semiconductors. They have no moving parts and can operate with a simple design of p-type and n-type materials.
2) Fuel cells also directly produce electricity from chemical reactions without combustion, like the Grove fuel cell developed in 1839.
3) Thermoelectric photovoltaic cells directly convert sunlight into electricity through the photovoltaic effect in semiconductor junctions.
Similar to Fpe 613 cold storage engineering.pptx (20)
1. FPE 613 Cold Storage Engineering
Thermo electric refrigeration system
Vortex tube
Cooling by adiabatic demagnetization
Presented by
Princess Monica PS
2019671804
PhD-FPE (1st year)
Course Teacher
Dr.N.Venkatachalapathy
Professor And Head
Food Process Engineering
IIFPT
Thanjavur
2. Contents :
Thermo electric refrigeration system
Vortex tube
Cooling by adiabatic demagnetization
3. Introduction
A thermoelectric refrigerator in the same way is a refrigerator that uses the
Peltier effect to create a heat flux between the junction of two different types of
materials.
The Peltier effect is a temperature difference created by applying a voltage
between two electrodes connected to a sample of semiconductor material.
This phenomenon can be useful when it is necessary to transfer heat from one
medium to another on a small scale.
4.
5. copper connection paths to the power supply.
the heat will be moved (or 'pumped') in the direction of
charge carrier flow throughout the circuit. actually, it is the
charge carriers that transfer the heat.
6. Thermoelectric cooling devices causes the junction to either cool
down(absorbing heat) or warm up (rejecting heat), depending on
the direction of the current.
The thermo-element materials are doped semiconductors, one n-
type with a majority of negative charge carriers (electrons) and the
other p-type with a majority of positive charge carriers (holes).
Behind the thermoelectric module an Heat Sink is fitted which
enables the conduction heat transfer from the hot side of module.
7. At the cold junction side of the thermoelectric module,
convective heat transfer takes place from air.
The whole thermoelectric module is fitted in a insulated
chamber
The whole assembly is connected to DC Power Supply.
8. WORKING PRINCIPLE
two ceramic substance that serve as a foundation and electrical
insulation for P-type and N-type Bismuth Telluride
The ceramics also serve as insulation between the modules
internal electrical elements and a heat sink
Electrically conductive materials, usually copper pads attached
to the ceramics, maintain the electrical connections inside the
module
The heat pumping action is actual function of the quantity of
electrons crossing over the p-n junction.
9. Method of Heat Transport:
Electrons can travel freely in the copper conductors but not so freely in the
semiconductor.
As the electrons leave the copper and enter the hot-side of the p-type, they drop down
to a lower energy level and release heat in the process.
Then, as the electrons move from the p-type into the copper conductor on the cold side,
the electrons are bumped back to a higher energy level and absorb heat in the process.
Next, the electrons move freely through the copper until they reach the cold side of the
n-type semiconductor.
Finally, when the electrons leave the hot-side of the n-type, they can move freely in the
copper. They drop down to a lower energy level and release heat in the process.
10. Between the heat generating device and the conductor must be an
electrical insulator to prevent an electrical short circuit between the
module and the heat source.
The electrical insulator must also have a high thermal conductivity so
that the temperature gradient between the source and the conductor
is small.
Ceramics like alumina are generally used.
11. Disadvantages
the limit to their cooling capacity and coefficient of
performance which may be restrictive in the future when heat
transfer demands become much larger.
A DC power supply is needed for the TE cooler.
12. ADVANTAGES
Effective in spot cooling.
Environmentally friendly.
Generate no electrical noise.
Small size and light weight.
Compact and reliable.
No moving parts and fluids.
Durable and maintenance-free.
Very long operation life.
13. APPLICATIONS
Include equipment used by military, medical, industrial,
consumer, scientific/laboratory, and telecommunications
organizations
Uses range from simple food and beverage coolers for an
afternoon picnic to extremely sophisticated temperature
control systems in missiles and space vehicles.
15. Vortex Tube Refrigeration
It is one of the non-conventional type refrigerating systems.
The vortex tube is a device which separates a high pressure
flow entering tangentially into two low pressure flows, there
by producing a temperature change.
simple device with no moving parts
16. It consists of
1. nozzle,
2. diaphragm,
3. valve,
4. hot-air side,
5. cold-air side.
17. Chamber is a portion of nozzle that facilities the tangential entry of high
velocity air-stream into hot side.
Hot side is cylindrical in cross section and is of different lengths as per
design.
Valve obstructs the flow of air through hot side and it also controls the
quantity of hot air through vortex tube.
Diaphragm is a cylindrical piece of small thickness and having a small hole
of specific diameter at the center.
Air stream traveling through the core of the hot side is emitted through the
diaphragm hole.
Cold side is a cylindrical portion through which cold air is passed.
18. Working:
Compressed air is passed through the nozzle. Here, air expands
and acquires high velocity due to particular shape of the nozzle.
A vortex flow is created in the chamber and air travels in spiral
like motion along the periphery of the hot side.
This flow is restricted by the valve.
partly closing the valve, a reversed axial flow through the core of
the hot side starts.
By controlling the opening of the valve, the quantity of the cold
air and its temperature can be varied.
19.
20. Advantages:
It uses air as refrigerant, so there is no leakage problem.
Vortex tube is simple in design and it avoids control systems.
There are no moving parts in vortex tube.
It is light in weight and requires less space.
Initial cost is low and its working expenses are also less, where
compressed air is readily available.
Maintenance is simple and no skilled labors are required.
Disadvantages:
Its low COP, limited capacity and only small portion of the compressed
air appearing as the cold air limits its wide use in practice.
21. Applications:
Vortex tubes are extremely small and as it produce hot as well as
cold air. It may be of use in industries where both are
simultaneously required.
Temperature as low as –50°C can be obtained without any
difficulty, so it is very much useful in industries for spot cooling of
electronic components.
It is commonly used for body cooling of the workers in mines.
23. Magnetic refrigeration is based on the magnetocaloric effect,
discovered by E. Warburg in 1881.
in which a temperature change of a suitable material is caused
by exposing the material to a changing magnetic field.
Similar to mechanical compression and expansion of gases,
there are some materials that raise their temperatures when
adiabatically magnetised, and drop their temperature when
adiabatically demagnetised.
24. Temperature very near the absolute zero may be obtained by
adiabatic demagnetization of certain paramagnetic salts.
Each atom of the paramagnetic salt may be considered to be
a tiny magnet.
If the salt is not magnetized then all its atoms or the magnets
are randomly oriented.
25.
26. If it is exposed to a strong magnetic field, the atoms will align themselves
to the direction of magnetic field.
the heat will be absorbed by Helium.
Now if the magnetic field is suddenly removed, the atoms will come back
to the original random orientation.
If there is no heat transfer from surroundings, the internal energy of the
salt will decrease as it does work. Consequently the salt will be cooled.
27. The substance is returned to adiabatic (insulated) condition
so the total entropy remains constant
the magnetic field is decreased, the thermal energy causes
the magnetic moments to overcome the field, and thus the
sample cools, i.e., an adiabatic temperature change.
Energy (and entropy) transfers from thermal entropy to
magnetic entropy, measuring the disorder of the magnetic
dipoles.
28. Paramagnetic salts like gadolinium sulphate are used.
This gives lower temperatures for a brief instant of time.
29. Advantages
No compressor and refrigerant gas
Low running cost
Less environment impact
Disadvantages
Initial investment is high
Protection of electronic components from magnetic fields
30. Applications
Cryogenic engine
Magnetic domestic refrigerator , magnetic air conditioning in
building and houses
Refrigeration in medicine
Bevarage coolers
Ice cream cabinets
31. References
Diana Enescu.2018.Thermoelectric Refrigeration Principles
Prashant Gour .2012. Experimental Encountering of Major Problems
Associated with Thermoelectric Refrigeration
Rajendra. P. Patil .2017. Thermoelectric Refrigeration Using Peltier Effect
Tejshree Bornare Vortex tube refrigeration system Based on Compressed air.
Chapter 15 Adiabatic Demagnetization
Lesson 8 Methods of producing Low Temperatures 1 Version 1 ME, IIT
Kharagpur