This document describes the development of a personal cooling system using thermoelectric cooling. It aims to maintain a stable core body temperature for workers in high heat environments. The system involves a cooling vest with water circulating tubes to remove a calculated heat load of 206W and keep skin temperature at 35°C. Heat transfer calculations are shown to determine the load from environmental, metabolic, and evaporative sources. Copper tubing is considered for its high thermal conductivity, with alternatives like PPS and LCP also evaluated. The low-cost, lightweight thermoelectric cooling vest could maintain core temperatures in situations where air conditioning is not possible.
Heat is produced in the human body through metabolism and must be dissipated to maintain a constant internal temperature. The body loses heat through convection, radiation, and evaporation from the skin and lungs. Several factors influence heat transfer such as environmental temperature, humidity, air motion, skin wettedness, and clothing. Clothing acts as insulation and reduces both sensible and latent heat loss. Understanding heat transfer mechanisms is important for designing clothing and heating/cooling systems for thermal comfort.
When the body is exposed to extreme heat conditions, the body most important mechanism to dissipate heat and prevent an increase in core temperature is sweating but when in cold conditions, in order to prevent hypothermia, the body's main objective is heat conservation predominantly through peripheral vasoconstriction
Thermoregulation [compatibility mode] (1)mohd ahmad
The document discusses thermoregulation and the physiological responses to exercise in heat and cold. It describes the mechanisms of heat loss from the body through conduction, convection, radiation, and evaporation. It explains how the hypothalamus acts as the body's thermostat to regulate temperature through cutaneous vasodilation and sweating in heat, and cutaneous vasoconstriction and shivering in cold. During exercise in heat, cardiovascular function is challenged and energy production increases to maintain homeostasis through increased sweating and blood flow to the skin.
Presentation deals with the heat transfer in human body. The working of lungs and blood vessels as heat exchanger is discusses along with thermal comfort.
Heat acclimatization occurs when repeated exercise-heat exposures are sufficiently stressful to invoke profuse sweating and elevate body temperatures. Generally, about 1-2-wk of daily exposures of 90 min are required; but highly aerobic fit athletes can heat acclimatize in half that time.
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.
The document discusses various topics related to heat and temperature. It defines different temperature scales including Fahrenheit, Celsius, and Kelvin. It explains how to convert between temperature scales using formulas. It describes concepts such as thermal capacity, specific heat capacity, phases of matter, phase changes, and latent heats. An example problem demonstrates how to calculate the heat required to change the phase of water from liquid to vapor.
Heat is produced in the human body through metabolism and must be dissipated to maintain a constant internal temperature. The body loses heat through convection, radiation, and evaporation from the skin and lungs. Several factors influence heat transfer such as environmental temperature, humidity, air motion, skin wettedness, and clothing. Clothing acts as insulation and reduces both sensible and latent heat loss. Understanding heat transfer mechanisms is important for designing clothing and heating/cooling systems for thermal comfort.
When the body is exposed to extreme heat conditions, the body most important mechanism to dissipate heat and prevent an increase in core temperature is sweating but when in cold conditions, in order to prevent hypothermia, the body's main objective is heat conservation predominantly through peripheral vasoconstriction
Thermoregulation [compatibility mode] (1)mohd ahmad
The document discusses thermoregulation and the physiological responses to exercise in heat and cold. It describes the mechanisms of heat loss from the body through conduction, convection, radiation, and evaporation. It explains how the hypothalamus acts as the body's thermostat to regulate temperature through cutaneous vasodilation and sweating in heat, and cutaneous vasoconstriction and shivering in cold. During exercise in heat, cardiovascular function is challenged and energy production increases to maintain homeostasis through increased sweating and blood flow to the skin.
Presentation deals with the heat transfer in human body. The working of lungs and blood vessels as heat exchanger is discusses along with thermal comfort.
Heat acclimatization occurs when repeated exercise-heat exposures are sufficiently stressful to invoke profuse sweating and elevate body temperatures. Generally, about 1-2-wk of daily exposures of 90 min are required; but highly aerobic fit athletes can heat acclimatize in half that time.
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.
The document discusses various topics related to heat and temperature. It defines different temperature scales including Fahrenheit, Celsius, and Kelvin. It explains how to convert between temperature scales using formulas. It describes concepts such as thermal capacity, specific heat capacity, phases of matter, phase changes, and latent heats. An example problem demonstrates how to calculate the heat required to change the phase of water from liquid to vapor.
Lec 7 tempreture regulation Physiology of Exerciseangelickhan2
This document summarizes how humans regulate body temperature through balancing heat production and heat loss. It discusses key terms like ectotherms, endotherms, and homeotherms. The body produces heat through metabolism and exercise. It loses heat through radiation, conduction, convection, and evaporation. The hypothalamus acts as the thermostat to maintain core temperature by initiating sweating or shivering responses. Precise measurements of core temperature and calculations are needed to understand heat balance during exercise.
Thermal physics discusses kinetic molecular theory and Brownian motion. Heat is defined as the flow of energy from a warm object to a cooler object. Heat energy is the result of atomic/molecular movement in solids, liquids and gases. Temperature is a measure of heat energy, with higher temperatures indicating faster particle movement. Thermometers measure temperature using various methods like liquid expansion. Thermal conduction transfers heat through particle collisions, while convection transfers heat through fluid movement. Radiation transfers heat as electromagnetic waves. The greenhouse effect occurs naturally but is enhanced by human emissions, contributing to global warming.
This document provides guidance on heat acclimatization strategies for military members attending training in hot weather. It explains that heat acclimatization improves tolerance to hot conditions and reduces risks of heat illness through biological adaptations. The document recommends starting heat acclimatization 1-2 weeks before training through daily heat exposure combined with gradually increasing physical exercise. Military members should drink sufficient fluids to replace sweat losses and maintain hydration during heat acclimatization.
Thermal qualities like temperature, heat, and heat transfer mechanisms are important for building design. Temperature is measured in degrees Celsius and heat is measured in joules. Heat transfers between objects through conduction, convection, and radiation based on temperature differences. A building's heat transfer is analyzed using factors like U-value, solar gain, ventilation rate, and time-lag. Maintaining a building's thermal balance requires considering all heat exchange between the interior and exterior environments.
This document discusses heat stress management for workers. It begins by outlining some of the dangers of heat stress, including increased mortality and reduced productivity. It then discusses factors that impact human tolerance to heat like humidity, acclimatization, clothing and health. Several heat stress indices are described, including WBGT, which is the most widely used but has limitations. Guidelines for work-rest regimes using WBGT values are provided. The document emphasizes that heat stress management requires considering both environmental and individual human factors. It suggests weather intelligence tools could help optimize planning to reduce heat risks.
Intro to thermodynamics
types of thermodynamics
1st law of thermodynamics
2nd law of thermodynamics
3rd law of thermodynamics
zeroth law of thermodynamics
types of processes
definition of heat, temperature, specific heat, thermal conductivity
system and surroundings
engineering physics- unit 3- thermal physics- thermodynamics- laws of thermodynamics- heat engine- carnot cycle- otto and diesel engine- forbes and lees disc method.
This chapter discusses temperature regulation during exercise. The body maintains core temperature through balancing heat production and heat loss. It produces heat through voluntary exercise and involuntary processes like shivering. Heat is lost via radiation, conduction, convection and evaporation. The hypothalamus acts as the body's thermostat, regulating responses like sweating and shivering. During exercise in heat, core temperature and sweat rate increase to balance heat. Acclimatization to heat enables higher sweat rates and reduced sodium loss. Cold environments enhance heat loss, while acclimatization improves non-shivering thermogenesis and intermittent blood flow.
This document provides an overview of key concepts in thermodynamics including heat, work, internal energy, and the first law of thermodynamics. It defines heat as the transfer of energy between objects due to temperature difference and work as the energy transferred when an object is moved against a force. The first law of thermodynamics states that the total energy within an isolated system remains constant; energy can be converted between heat and work but not created or destroyed. It also explains how to determine the sign of heat and work transfers based on whether energy is entering or leaving the system and how to calculate changes in internal energy using the first law of thermodynamics.
The thermoregulatory center located in the hypothalamus monitors core body temperature and activates heat-losing or heat-generating mechanisms through negative feedback loops. Heat is produced through metabolic processes and lost through radiation, conduction, convection, and evaporation. Temperature disorders occur when the body cannot maintain core temperature, such as with heat exhaustion from excessive sweating or heat stroke when the core temperature reaches dangerously high levels above 41°C. Hypothermia is a lowering of core temperature below 35°C that can be life-threatening if not treated by slowly rewarming the body.
This document discusses heat transfer and heat exchangers. It defines key units used in heat transfer such as temperature, heat, and heat capacity. It describes different types of heat including latent heat and methods of heat transfer including conduction, convection, and radiation. Specifically, it explains that heat is transferred through conduction by the movement of free electrons in metals and vibration of atoms/molecules, with the rate of conduction determined by thermal conductivity. It also provides examples of thermal conductivity values for common materials.
The document describes two experiments to measure the specific latent heat of fusion and vaporization of water. The first experiment measures the specific latent heat of fusion as ice is added to water, cooling it. Raw temperature and time data is plotted in a graph. The second experiment applies a constant power to heat water and measures the specific latent heat of vaporization. Both experiments measure how thermal energy flows when water changes phase, and the specific latent heats quantify the energy absorbed or released during these phase changes.
Basic refrigeration system & practice theory bookAmrendra Tiwari
This document provides an overview of refrigeration fundamentals and thermodynamics. It defines key refrigeration concepts like refrigeration, temperature scales, pressure, heat, latent heat and more. It also describes the types of thermodynamic systems and laws of perfect gases. Various refrigeration tools are listed, including tube cutters, flaring tools, manifold gauges, vacuum pumps and refrigerant recycling stations. Safety is emphasized as an important consideration in refrigeration work.
This experiment aimed to measure the specific latent heat of vaporization of water. The researcher measured the mass change of a kettle of boiling water over time. This was used to calculate the latent heat of vaporization, which averaged around 3140000 J/kg in trials 1-3 and 3301000 J/kg in trial 4. However, these values are much higher than the accepted literature value of 2260000 J/kg. Sources of error included uncertainty in the kettle's power rating and heat loss due to the uncovered kettle. Improving the experiment could involve directly measuring the kettle's power and using a scale able to measure the kettle with its lid on.
Ivanolegov thermodynamics serbian 4th edition test bank 1Ivan Olegov
Thermal energy is the energy a compound or system has due to its temperature, i.e., the power of moving or shaking molecules, according to the Power Education web site of the Texas Education Company. Thermodynamics involves determining this energy, which can be "exceptionally complicated," according to David McKee, a teacher of physics at Missouri Southern State University. Commonly this is idealized as the mass of the system, the stress of the system, and the quantity of the system, or some various other comparable set of numbers.
The objective was to compare cooling of peaches via free and forced convection. Peaches were submerged in ice baths with one peach stirred (forced convection) and the other stationary (free convection). Temperature was measured every minute until reaching 7.5°C. Forced convection cooled the peach faster, in 25.14 minutes with a convection coefficient of 3,105 W/(m2K), while free convection took 43.17 minutes with a coefficient of 41.38 W/(m2K). COMSOL models showed faster cooling under forced convection due to higher heat transfer rates.
This document discusses the three main modes of heat transfer: conduction, convection, and radiation.
Conduction involves the direct transfer of energy between objects in physical contact. Convection involves the transfer of energy between an object and its environment due to fluid motion. Radiation involves the transfer of energy to or from a body by means of electromagnetic waves.
The document provides examples of each mode, including how metals conduct heat via free electrons and how non-metals rely on molecular vibration. It also discusses key concepts like film coefficients, shape factors, and the Stefan-Boltzmann law governing radiation between surfaces.
The document discusses several topics related to heat and temperature, including:
1. It defines temperature as a measure of the average kinetic energy of atoms and molecules in a gas or substance, with higher temperatures corresponding to faster molecular motion.
2. It describes different devices that can be used to measure temperature, such as mercury thermometers, gas thermometers, pyrometers, and electrical resistance thermometers.
3. It explains concepts such as heat capacity, specific heat capacity, calorimetry, latent heat, phase changes, conduction, convection, radiation, and Newton's Law of Cooling.
Thermal comfort depends on factors like air temperature, humidity, air movement, metabolic rate, and clothing. The human body generates heat through metabolism, and maintains its core temperature through convection, conduction, evaporation and radiation between the body and its environment. When designing buildings, the goal is to create a thermally comfortable environment through factors like insulation, ventilation, and passive heating/cooling to balance the body's heat production and loss.
This document discusses heat stress evaluation for workers in hot environments. It presents various heat stress indices like WBGT, which is the most commonly used method. A case study describes a worker who died from heat stroke after experiencing symptoms for two hours while doing lawn work in conditions that exceeded the heat stress threshold. The document provides steps to calculate WBGT and determine if exposure exceeded limits. It recommends preventive measures like scheduling hot work during cooler times, increasing water intake, and educating workers on heat-related disorders.
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.
Lec 7 tempreture regulation Physiology of Exerciseangelickhan2
This document summarizes how humans regulate body temperature through balancing heat production and heat loss. It discusses key terms like ectotherms, endotherms, and homeotherms. The body produces heat through metabolism and exercise. It loses heat through radiation, conduction, convection, and evaporation. The hypothalamus acts as the thermostat to maintain core temperature by initiating sweating or shivering responses. Precise measurements of core temperature and calculations are needed to understand heat balance during exercise.
Thermal physics discusses kinetic molecular theory and Brownian motion. Heat is defined as the flow of energy from a warm object to a cooler object. Heat energy is the result of atomic/molecular movement in solids, liquids and gases. Temperature is a measure of heat energy, with higher temperatures indicating faster particle movement. Thermometers measure temperature using various methods like liquid expansion. Thermal conduction transfers heat through particle collisions, while convection transfers heat through fluid movement. Radiation transfers heat as electromagnetic waves. The greenhouse effect occurs naturally but is enhanced by human emissions, contributing to global warming.
This document provides guidance on heat acclimatization strategies for military members attending training in hot weather. It explains that heat acclimatization improves tolerance to hot conditions and reduces risks of heat illness through biological adaptations. The document recommends starting heat acclimatization 1-2 weeks before training through daily heat exposure combined with gradually increasing physical exercise. Military members should drink sufficient fluids to replace sweat losses and maintain hydration during heat acclimatization.
Thermal qualities like temperature, heat, and heat transfer mechanisms are important for building design. Temperature is measured in degrees Celsius and heat is measured in joules. Heat transfers between objects through conduction, convection, and radiation based on temperature differences. A building's heat transfer is analyzed using factors like U-value, solar gain, ventilation rate, and time-lag. Maintaining a building's thermal balance requires considering all heat exchange between the interior and exterior environments.
This document discusses heat stress management for workers. It begins by outlining some of the dangers of heat stress, including increased mortality and reduced productivity. It then discusses factors that impact human tolerance to heat like humidity, acclimatization, clothing and health. Several heat stress indices are described, including WBGT, which is the most widely used but has limitations. Guidelines for work-rest regimes using WBGT values are provided. The document emphasizes that heat stress management requires considering both environmental and individual human factors. It suggests weather intelligence tools could help optimize planning to reduce heat risks.
Intro to thermodynamics
types of thermodynamics
1st law of thermodynamics
2nd law of thermodynamics
3rd law of thermodynamics
zeroth law of thermodynamics
types of processes
definition of heat, temperature, specific heat, thermal conductivity
system and surroundings
engineering physics- unit 3- thermal physics- thermodynamics- laws of thermodynamics- heat engine- carnot cycle- otto and diesel engine- forbes and lees disc method.
This chapter discusses temperature regulation during exercise. The body maintains core temperature through balancing heat production and heat loss. It produces heat through voluntary exercise and involuntary processes like shivering. Heat is lost via radiation, conduction, convection and evaporation. The hypothalamus acts as the body's thermostat, regulating responses like sweating and shivering. During exercise in heat, core temperature and sweat rate increase to balance heat. Acclimatization to heat enables higher sweat rates and reduced sodium loss. Cold environments enhance heat loss, while acclimatization improves non-shivering thermogenesis and intermittent blood flow.
This document provides an overview of key concepts in thermodynamics including heat, work, internal energy, and the first law of thermodynamics. It defines heat as the transfer of energy between objects due to temperature difference and work as the energy transferred when an object is moved against a force. The first law of thermodynamics states that the total energy within an isolated system remains constant; energy can be converted between heat and work but not created or destroyed. It also explains how to determine the sign of heat and work transfers based on whether energy is entering or leaving the system and how to calculate changes in internal energy using the first law of thermodynamics.
The thermoregulatory center located in the hypothalamus monitors core body temperature and activates heat-losing or heat-generating mechanisms through negative feedback loops. Heat is produced through metabolic processes and lost through radiation, conduction, convection, and evaporation. Temperature disorders occur when the body cannot maintain core temperature, such as with heat exhaustion from excessive sweating or heat stroke when the core temperature reaches dangerously high levels above 41°C. Hypothermia is a lowering of core temperature below 35°C that can be life-threatening if not treated by slowly rewarming the body.
This document discusses heat transfer and heat exchangers. It defines key units used in heat transfer such as temperature, heat, and heat capacity. It describes different types of heat including latent heat and methods of heat transfer including conduction, convection, and radiation. Specifically, it explains that heat is transferred through conduction by the movement of free electrons in metals and vibration of atoms/molecules, with the rate of conduction determined by thermal conductivity. It also provides examples of thermal conductivity values for common materials.
The document describes two experiments to measure the specific latent heat of fusion and vaporization of water. The first experiment measures the specific latent heat of fusion as ice is added to water, cooling it. Raw temperature and time data is plotted in a graph. The second experiment applies a constant power to heat water and measures the specific latent heat of vaporization. Both experiments measure how thermal energy flows when water changes phase, and the specific latent heats quantify the energy absorbed or released during these phase changes.
Basic refrigeration system & practice theory bookAmrendra Tiwari
This document provides an overview of refrigeration fundamentals and thermodynamics. It defines key refrigeration concepts like refrigeration, temperature scales, pressure, heat, latent heat and more. It also describes the types of thermodynamic systems and laws of perfect gases. Various refrigeration tools are listed, including tube cutters, flaring tools, manifold gauges, vacuum pumps and refrigerant recycling stations. Safety is emphasized as an important consideration in refrigeration work.
This experiment aimed to measure the specific latent heat of vaporization of water. The researcher measured the mass change of a kettle of boiling water over time. This was used to calculate the latent heat of vaporization, which averaged around 3140000 J/kg in trials 1-3 and 3301000 J/kg in trial 4. However, these values are much higher than the accepted literature value of 2260000 J/kg. Sources of error included uncertainty in the kettle's power rating and heat loss due to the uncovered kettle. Improving the experiment could involve directly measuring the kettle's power and using a scale able to measure the kettle with its lid on.
Ivanolegov thermodynamics serbian 4th edition test bank 1Ivan Olegov
Thermal energy is the energy a compound or system has due to its temperature, i.e., the power of moving or shaking molecules, according to the Power Education web site of the Texas Education Company. Thermodynamics involves determining this energy, which can be "exceptionally complicated," according to David McKee, a teacher of physics at Missouri Southern State University. Commonly this is idealized as the mass of the system, the stress of the system, and the quantity of the system, or some various other comparable set of numbers.
The objective was to compare cooling of peaches via free and forced convection. Peaches were submerged in ice baths with one peach stirred (forced convection) and the other stationary (free convection). Temperature was measured every minute until reaching 7.5°C. Forced convection cooled the peach faster, in 25.14 minutes with a convection coefficient of 3,105 W/(m2K), while free convection took 43.17 minutes with a coefficient of 41.38 W/(m2K). COMSOL models showed faster cooling under forced convection due to higher heat transfer rates.
This document discusses the three main modes of heat transfer: conduction, convection, and radiation.
Conduction involves the direct transfer of energy between objects in physical contact. Convection involves the transfer of energy between an object and its environment due to fluid motion. Radiation involves the transfer of energy to or from a body by means of electromagnetic waves.
The document provides examples of each mode, including how metals conduct heat via free electrons and how non-metals rely on molecular vibration. It also discusses key concepts like film coefficients, shape factors, and the Stefan-Boltzmann law governing radiation between surfaces.
The document discusses several topics related to heat and temperature, including:
1. It defines temperature as a measure of the average kinetic energy of atoms and molecules in a gas or substance, with higher temperatures corresponding to faster molecular motion.
2. It describes different devices that can be used to measure temperature, such as mercury thermometers, gas thermometers, pyrometers, and electrical resistance thermometers.
3. It explains concepts such as heat capacity, specific heat capacity, calorimetry, latent heat, phase changes, conduction, convection, radiation, and Newton's Law of Cooling.
Thermal comfort depends on factors like air temperature, humidity, air movement, metabolic rate, and clothing. The human body generates heat through metabolism, and maintains its core temperature through convection, conduction, evaporation and radiation between the body and its environment. When designing buildings, the goal is to create a thermally comfortable environment through factors like insulation, ventilation, and passive heating/cooling to balance the body's heat production and loss.
This document discusses heat stress evaluation for workers in hot environments. It presents various heat stress indices like WBGT, which is the most commonly used method. A case study describes a worker who died from heat stroke after experiencing symptoms for two hours while doing lawn work in conditions that exceeded the heat stress threshold. The document provides steps to calculate WBGT and determine if exposure exceeded limits. It recommends preventive measures like scheduling hot work during cooler times, increasing water intake, and educating workers on heat-related disorders.
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.
The document provides learning objectives and content for a chapter on thermodynamics. It covers key concepts like the first and second laws of thermodynamics, thermal processes, and using the ideal gas law. For thermal processes using ideal gases, it defines equations for isothermal, adiabatic, isobaric and isochoric processes. Examples are provided for calculating work done during isothermal expansion of an ideal gas and adiabatic compression. The chapter sections will address thermodynamic systems, the laws of thermodynamics, thermal processes, processes for ideal gases, and applications like heat engines and entropy.
Application of Nonlinear Programming to Heat Conduction ModelDr. Amarjeet Singh
The design of high-temperature working clothes is a
process of theoretical analysis and design of all layers of
working clothes based on the premise that human body
avoids burns under the high-temperature environment.
Steady temperature mathematical model in this paper,
through the establishment of system, determine the optimal
heat work suit II layer thickness is actually an optimization
problem, has been the function relation between the
temperature and time conditions, through Fourier heat
conduction law, obtained the system ultimately a function of
temperature and material thickness, and has set up a
nonlinear programming problem, the introduction of the
simulated annealing algorithm, and joined the convection and
radiation in the algorithm the two factors affect the optimal
solution, finally satisfied under the condition of the optimal
thickness of the second floor.
Natural Climatic Control using Conceptual Elements in a Building for Human Co...YogeshIJTSRD
With respect to comfort inside the building to distinguish between thermal comfort lighting important of these effects is thermal comfort which is primarily compared by four major factors the air temperature, Maine radiant temperature, Humidity and Air flow. An extended work of the American society of heating, refrigerating and accordingly engineers ASHRE. The thermal comfort is that condition of mind which expresses satisfaction in the thermal environment. Basic physical and physiological measurements of temperature and heat flux of represent location of a human body have yielded the following results. Dr. Mukesh Kumar Lalji "Natural Climatic Control using Conceptual Elements in a Building for Human Comfort" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43783.pdf Paper URL: https://www.ijtsrd.com/other-scientific-research-area/enviormental-science/43783/natural-climatic-control-using-conceptual-elements-in-a-building-for-human-comfort/dr-mukesh-kumar-lalji
1) The document describes an experiment on radial heat conduction. Thermocouples were used to measure the temperature at different points in a brass cylinder as heat was applied to determine the thermal conductivity.
2) Thermal conductivity values were calculated at different measurement points using Fourier's law. The values ranged from 0 to 187.948 W/m°C.
3) Radial heat conduction is important in applications like heat exchangers and engines. It allows understanding how temperature varies from the center to outer surfaces of materials.
This document discusses the design and analysis of an air-conditioned tricycle that uses thermoelectric cooling. The system uses multiple thermoelectric Peltier modules to absorb heat from the air and provide cooling. Rectangular fins and fiber sheets are used to improve heat transfer from the modules. The design is intended to provide cooling without using ozone-depleting refrigerants. Experimental results showed the thermoelectric system was able to achieve a cooling power of 50W per module with a coefficient of performance between 1.5-2. The document reviews several other studies on thermoelectric cooling systems and their advantages over traditional vapor-compression air conditioners.
Thermal comfort is affected by factors like air temperature, humidity, air movement, and radiant heat. Over time, indices have been developed to quantify thermal comfort, including effective temperature and corrected effective temperature. Properly measuring factors like air temperature, humidity, air velocity, and radiant heat is necessary to evaluate thermal conditions and design appropriate heating/cooling systems. Key instruments used in measurement include dry bulb thermometers, wet bulb thermometers, psychrometers, globe thermometers, and Kata thermometers. Common heat stress indices are effective temperature and the wet bulb globe temperature index.
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.
This document discusses heat, temperature, and thermometry. It defines heat as the internal energy associated with the motion and arrangement of atoms and molecules within a body that is transferred due to a temperature difference. Temperature is defined as the degree of hotness or coldness of a body, and is measured in kelvin. Various types of thermometers are described that use the temperature-dependent properties of materials like mercury, gases, resistive metals, and thermocouples to measure temperature over different ranges.
This document discusses temperature measurement and regulation in the human body. It covers several topics:
1. It describes different techniques for measuring temperature, including mercury thermometers, resistance thermometers, thermistors, and thermocouples.
2. It explains how the human body tightly regulates its core temperature around 37°C through balancing heat production and heat loss, despite variations in environmental temperatures.
3. During anesthesia, temperature regulation can be impacted and precautions must be taken to prevent hypothermia or hyperthermia in surgical patients. External heating or cooling can also pose burn risks if temperatures at the body surface become too high or low.
study material on shell and tube heat exchagers.pdfKaustav Patnaik
This document provides an overview of shell and tube heat exchangers and basic calculations. It defines key terms related to heat transfer and energy units. The document discusses specific heat, heat exchanger calculations using the basic heat transfer equation, and outlines the overall design process for a heat exchanger. An example calculation is provided to estimate the heat exchanger area and cooling water flow rate required to cool light oil using cooling water.
1. The document discusses heat transfer through conduction in fluids and determining the thermal conductivity of water. An apparatus is used to study heat conduction in air and water without natural convection.
2. The thermal conductivity of air is known and used to calculate the heat transfer and losses in the apparatus. This allows determining the thermal conductivity of water.
3. The second part of the document discusses determining the natural convection heat transfer coefficient for a vertically oriented cylindrical tube exposed to atmospheric air and losing heat through natural convection. Different heating levels are used to study natural convection pipe flows.
Introduction to transient Heat conduction, Lamped System Analysis, Approxiamate Analytical and graphical method and Numerical method for one and two dimensional heat conduction by using Explicit and Implicit method
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document discusses objective methods for measuring heat transport properties of clothing. It begins by describing the importance of measuring heat transport and the mechanisms by which heat is transported through clothing. It then discusses three main instruments used for objective measurement: the togmeter, guarded hot plate method, and Alambeta instrument. For each, it provides details on the basic principles and procedures used to measure thermal conductivity, resistance, and transmittance of fabrics. The document aims to explain the key objective methods utilized in analyzing the heat transport behavior of clothing materials.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document discusses objective methods for measuring heat transport properties of clothing. It begins by describing the importance of measuring heat transport and the mechanisms by which heat is transported through clothing. It then discusses three main instruments used for objective measurement: the togmeter, guarded hot plate method, and Alambeta instrument. For each, it provides details on the basic principles and procedures used to measure thermal conductivity, resistance, and transmittance of fabrics. The document aims to explain the key objective methods and instruments utilized in analyzing the heat transport behavior of clothing materials.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document discusses objective methods for measuring heat transport properties of clothing. It begins by describing the importance of measuring heat transport and the mechanisms by which heat is transported through clothing. It then discusses three main instruments used for objective measurement: the togmeter, guarded hot plate method, and Alambeta instrument. For each, it provides details on the basic principles and procedures used to measure thermal conductivity, resistance, and transmittance of fabrics. The document aims to explain the various objective methods utilized to evaluate the heat transport behaviors of clothing materials.
design of passive down draft cool tower for 100 m2 auditoriumINFOGAIN PUBLICATION
A passive down draft evaporative cooling (PDEC) tower is design to capture the wind at high temperature typically at 40ο C and above the top of tower and cool the outdoor air using water which is allowed to flow through shower and due to evaporation of water out door air gets cooled. Many different types of PDEC exist. This paper explains design of PDEC tower. It is a parallel flow heat exchanger with hot and cold fluid are in direct contact with each other. The wet bulb temperature of air is the lowest possible temperature of the air leaving the tower and entering in air conditioned space. It is suitable in hot dry climate due to large difference between dry and wet bulb temperatures. The mathematical model predicted with the variation of wind speed from 1 m/s to 6 m/s with outside air temperature 35 ο C and relative humidity 20 %, a tower height of 6 m is required.
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Development of microclimate personal cooling system based on thermoelectric effect
1. International Journal For Research & Development in Technology
Volume: 1, Issue: 2, JUNE 2014 ISSN (Online):- 2349-3585
1 Copyright 2014- IJRDT www.ijrdt.org
Development of Microclimate Personal
Cooling System Based on Thermoelectric
Effect
Amal joseph1
, Alen Mathew2
,
Amal Mathew Varghese3
, Harry John4
, Francis AJ5
1234
U G Student, 5
Assistant Professor, Saintgits College of Engineering
Department Of Mechanical Engineering, Saintgits College of Engineering
Kerala.
E-Mail: 1
amalavert@gmail.com, 2
alenmathew19@yahoo.com, 3
amalmv0710@gmail.com,
4
harryj25@gmail.com, 5
francis.augustine@saintgits.org
Abstract— This article investigates the effect of a
thermoelectric assisted water cooling method for the
regulation of core body temperature of workers exposed to
high temperature environments. The global objective for this
microclimate personal cooling system is to establish a stable
core body temperature and enhance performance of
individuals in long time exposure to environments of
extreme heat. This article contains determination of the heat
load required to remove to keep the core body temperature of
individual working in specified working conditions through
calculation and data collection, design a thermoelectric
cooling (TEC) system that can meet the calculated load
considering design parameters of thermoelectric coolers,
Provide experimental and software analysis of various
components and working of whole system. Analysis involves
CFD analysis of flow through tubing for the software
confirmation of calculated values. The proposed cooling vest
with its low cost, weight, and power consumption makes
itself an excellent alternative where conventional air
conditioning systems fails.
Keywords— Thermoelectric module, Thermoelectric cooling
vest, Heat stress, Peltier effect, Heat transfer.
INTRODUCTION
There are many situations where conventional air conditioning
systems fails. Workers exposed to harsh environment are
likely to have heat stress. Providing a microclimate system for
personal cooling is the only option in those situations. This
article focuses on developing a microclimate cooling system
in the form of a cooling vest works on the principle of Peltier
effect.
The human body maintains a fairly constant core temperature,
primarily through varying the rate and amount of blood
circulation through the skin and the release of fluid onto the
skin by the sweat glands. Hot working conditions demand a
stable core body temperature. If a person is failed to achieve a
stable condition it affects adversely the peak performance of
him/her, and also possess detrimental health effects such as
heat stroke/stress, cramps, fainting, and breakdown of central
nervous system when core body temperature reaches above
41.5˚C.
Objective of this research is to demonstrate the proposed
cooling system can assist to maintain stable core body
temperature of individuals working in extreme harsh
environments. This is achieved by maintaining a constant skin
temperature of 35˚C. A thermoelectric cooler maintains
temperature of water at 21 ˚C so that when it is pumped
through cooling tubes can take a heat load of 206 W in order
to maintain body temperature to desired levels.
The critical body temperature for peak performance is
between 38.33˚C and 39˚C as stated in [1]. This temperature
represents heat stress for situations that are not encountered
for prolonged time periods. The benefit of a cooling system
would be to prevent the individuals from reaching this point,
by maintaining the core body temperature at a lower safe
temperature; one that is maintained by the body. This vest will
be designed to reduce or eliminate the detrimental effects of
heat stress and strain.
Heat strain reaches a very dangerous level at a body
temperature of 40˚C. This temperature is accepted as the onset
temperature where a human is in impending danger of
irreversible heat stroke [1]. The atmospheric temperature
alone is dangerous to the human body, but, coupled with long
periods of exercise, a fatal situation can result. The human
body itself generates heat due to its metabolic procedures; heat
is gained as well from the environment.
I. DESIGN APPROACH
The following methodology is adopted in this article for
the design of thermoelectric assisted microclimate cooling
system. Work includes designing a torso region microclimate
cooling vest to provide the necessary cooling for the worker.
2. International Journal For Research & Development in Technology
Volume: 1, Issue: 2, JUNE 2014 ISSN (Online):- 2349-3585
2 Copyright 2014- IJRDT www.ijrdt.org
Problem definition
Heat load calculations
Design of vest and cooling systems
Material and system selection
Software and experimental analysis
A. Problem Definition
Considering a person working in harsh working conditions
of 48˚C and low relative humidity 9-11% RH [3]. Personal
cooling system needed to keep skin temperature Tsk as 35˚C.
This is to keep the core body temperature, Tcore as 37˚C. Body
temperature increasing beyond 41.5˚C causes heat stroke. An
individual exposed to such elevated temperature for longer
duration is likely to have his core temperature gradually
increased.
Protective clothing minimizes the radiation heat stress on
individuals and conduction. Convection heat transfer is also
negligible because the clothing is tightly fitted on the worker,
thus reducing the air flow space between the individual. The
heat transfer from the environment heats up the clothing and
thus the core body temperature will rise. Altering the
microclimate around the individual with the help of cooling
vest will provide a stable core body temperature within
permissible limits.
B. Heat Load Calculation
Basic heat transfer mechanism governs the entire process
in this article. The total heat stress developed in human body
is the sum of metabolic heat generated in body, heat gained
from environment and heat loss from body (which is negative)
[1]. The same is expressed below,
Total Heat stress = heat generated in the body (metabolic heat)
+ heat gained from the environment (environmental heat)-heat
loss from the body
NIOSH gives the basic heat balance equation,
ΔS= (M-W) ± C ± R –E
Where ΔS is the change in body heat content, (M-W) is
Total metabolism – external work performed, C is the
convection heat exchange, R is the radiative heat exchange, E
is the evaporative heat loss.
1) Convection:The rate of convective heat exchange is a
function of the difference in temperature between the ambient
air (Ta) and the mean weighted skin temperature (Tsk) and the
rate of air movement over the skin (Va).
C= 7.0×Va
0.6
(Ta-Tsk)= 7.0×0.20.6
(48-35)=39.64 W
Where C is the convective heat exchange, Va is air
velocity in meters per second.
2) Radiation: The radiative heat exchange is primarily a
function of the temperature gradient between the mean radiant
temperature of the surroundings (Tw) and the mean weighted
skin temperature (Tsk). Radiant heat exchange is a function of
the fourth power of absolute temperature of the solid
surroundings less the skin temperature (Tw - Tsk) but an
acceptable approximation for the customary one-layer clothed
individual is
R= 6.6×( Tw - Tsk) = 6.6×(48-35)=85.8 Kcal/hr =98.2 W
Where R is the radiant heat exchange.
3) Evaporation: The evaporation of water (sweat) from
the skin surface results in a heat loss from the body.The
maximum evaporative capacity is a function of air motion (Va)
and the water vapor pressure difference between the ambient
air (Pa) and the water vapor pressure difference between the
ambient air (Pa) and the wetted skin at temperature (Psk) the
equation for this relationship is for the customary one layer
clothed worker
E=2.4×Va
0.6
×(Psk-Pa)= 14×0.20.6×(42.2-8.37) =206.37 W
Where E is the evaporative heat loss
4) Metabolic Heat: This is the heat generated in the
body due to metabolic activities. Exact calculation of this heat
content will differ from person to person. Thus a standard
procedure is followed here. Metabolic heat can be taken as 4
kcal/min for a 70 Kg male. This is the sum of 3 kcal/min for
strenuous walking, 1 kcal/m in for using arms to carry
machinery, and perform difficult tasks as stated in [1].
Metabolic heat, M=274.67 W
Total heat stress, Q˙=M+C+R-E=274.67+39.64+98.2-
206.37=206.14 W
Total heat stress is the heat load which has to be removed
from the body to maintain the core body temperature to a
constant value. External work has to be performed to nullify
the effects of external heat loads. This work is obtained in the
form of cooling effect from TEC.
C. Heat Removal Calculations
The heat load removal from the body is calculated as
follows. For the water flowing through the copper tube,
uniform heating is assumed to be provided to the flowing
water by the body at elevated temperature of 450
c and the
inlet temperature of water is 200
c [2]. Following simple heat
transfer equations it can be found that outlet temperature of
water is 21.50
c.
The Reynolds number is found as 9282.045. This implies
that the flow is laminar. From the relation between Nusselt
number and heat transfer coefficient, we can calculate the heat
transfer coefficient value as 8043.1055 W/m2
K.
D. Design of the Tube and Vest
Based on the heat load calculations suitable vest material
and tube can be selected. The water that is cooled in the
system is circulated through the body through the tubes which
are kept in contact with the body and stitched to the jacket.
The material that must be used as the tube must be suitably
selected that enables perfect heat transfer and sufficient
flexibility
3. International Journal For Research & Development in Technology
Volume: 1, Issue: 2, JUNE 2014 ISSN (Online):- 2349-3585
3 Copyright 2014- IJRDT www.ijrdt.org
TABLE I
COMPARISON OF TUBE MATERIALS
Properties Tube material
Copper Polyphenylene
Sulfide (PPS)
Liquid
Crystalline
Polymer
(LCP)
Thermal
conductivity
398 W/mK 20 W/mK 20W/mK
Density 8.96 g/cc 1.7 g/cc 1.84 g/cc
Advantages Easily
available in
loose, High
k value,
Lower
price
High flexibility High flexibility
Disadvantage
s
Less
flexibility
Available in
bulk only, low
K value
Available in
bulk only, low
K value
Table I shows copper is a potential tube material but offers
less flexibility. Thermally conducting polymers provides
better flexibility. This article investigates cooling effects when
copper is used as the tube material.
Factors taken into consideration in choosing vest material
are the cost and close fit for the wearer. It is preferable to have
less material between the tube and body to improve heat
conduction. This article suggests single layer clothing.
Materials can be used are rexin and nylon blend or mesh
fabric. Meshed fabric is preferred because of its air
permeability and light weight property. Air permeability
enables removal of heat by evaporative mode.
The vest should be light weight and comfortable. The vest
has 2 layers. The layers are the outer shell of the vest, the
inner mesh lining along with copper tubing pass in between.
Each layer serves its own purpose in the vest. The outer shell
of the jacket helped to protect the human torso from the
harmful effects of the sun. The inner mesh lining provided a
pathway allowing for tubing and a structural support.
E. Thermoelectric Module Selection
A TEC is a cooling/heating device based on
Peltier‐Seebeck effect. It can be considered a small heat
pump that contains no moveable parts, which can be
extremely advantageous. Inside is a heat flux created between
the junctions of the two metals. Two wires are attached to one
side of the TEC to allow for a power supply to run a current
into the system. This transfer of heat from one side to the
other is produced by the electric current that is supplied
through the wires.
The main process that takes place in the jacket is that
water is being circulated through the jacket through selected
tubes, and the water absorbs heat from the body producing the
cooling effect. This water then reaches the cylinder and the
thermoelectric modules attached to the cylinder cool the water
to initial condition.
The water reaching the cylinder after a circulation is
usually at a high temperature almost equal to ambient
temperature and this temperature is reduced to 21.50C with
the help of thermoelectric modules attached to the cylinders.
The heat to be removed from body to keep the body
temperature at 200C is,
Q˙ = m˙cp(Te-Ti)= 0.03317* 4178*1.5=206.14 W
TABLE II
THERMOELECTRIC MODULES AND THEIR SPECIFICATIONS
Product
Imax
(amps)
Vmax
(volts)
Qmax
(watts)
TE-127-2.0-1.15 16.1 15.7 156
VT-199-1.4-0.8 11.3 24.6 172
HP-199-1.4-0.8 11.3 24.6 172
DRIFT 06 11.3 24.9 170
The above table II shows different thermoelectric modules
which are available in market. When consider the requirement
of 206.14 W to be removed, it is preferred to use Drift 06
thermoelectric module as the heat removing capability and
also the physical parameter as mentioned in the table suits the
need. Drift 06 is known as Deltron High Effective Single
Stage Module Drift 06.
The properties of drift 06 are:
• The dimensions are usually 30 x 30mm to 48 x48mm
• The height ranges from 3.2mm to 4.1mm
• The cooling capacity 170 W
• The voltage needed is 24.9V
• The current it takes is 11.3A
• The temperature difference 69°C to 74°C
F. Schematics of Cooling System
The system consists of an aluminium cylinder on to which
the thermoelectric modules are being attached in diametrically
opposite sides. The figure 1 shows the CATIA model of the
TEC assembly which matches our prototype TEC system. The
one end of the tubing is attached to the top of the cylinder
which is the return passage and the other end is attached to a
pump which is drilled to the cylinder with no leakage of water.
Fig. 1 CATIA model of TEC assembly
The cooling system consists of the thermoelectric system
and the jacket. The thermoelectric system comprises of the
thermoelectric modules, pump, fans and the tube is attached to
the jacket, ends to the system. A schematic of the cooling
system is shown in fig 3.
4. International Journal For Research & Development in Technology
Volume: 1, Issue: 2, JUNE 2014 ISSN (Online):- 2349-3585
4 Copyright 2014- IJRDT www.ijrdt.org
Fig. 2 Cooling System schematics
Water is mainly used in the system as the refrigerant. The
water which is cooled in the cylinder using the thermoelectric
modules is pumped through the tube using a pump. The one
end of the tube is attached to the pump and the other end on
the top of the cylinder through which water circulates back to
the cylinder.
When water flows through the tubes it absorbs heat from
the body and temperature of water increases and this water
flows back into the cylinder which is cooled using the
thermoelectric modules. Thus the cooling effect takes place
and the body temperature gets reduced. Heat load calculations
are done in order to calculate the amount of water needed and
the thermoelectric cooling module.
II. ANALYSIS AND RESULTS
Software analysis using ANSYS CFD is carried for the
verification of the calculated heat load values. This software
analysis also provides a data base for future systems
considering different load conditions. Experimental analysis
are carried out in a prototype.
A. Software Analysis
Software analysis of the tube flow was carried out using
ANSYS software. The main objective of ANSYS analysis was
the software confirmation of heat load calculation and to
obtain a data base so that further studies can be carried out on
the basis of this. CFD model of tube flow is illustrated below.
ANSYS CFD software is used for the simulation of flow
through tubing and heat transfer.
Geometry for the analysis is generated using CATIA with
following dimensions,
• Length = 6 m
• Internal diameter = 5.7 mm
• Outer diameter = 6 mm
Based on thermodynamic and heat transfer principle, the
input parameters required to carry out the analysis are the inlet
velocity and temperature. From discharge calculations the
velocity is calculated. Inlet temperature is set to a constant
value based on the TEC characteristics.
• Inlet velocity = 1.3 m/s
• Inlet temperature = 303 K
• Flow type = laminar
Water flowing through the tubing is constantly under a heat
load generated by body which accounts for the heat gained
from environment as well as the heat generated due to
metabolic activities. From NIOSH data this heat load is
calculated as 206 W, i.e, surface heat load 206 W.
Following results are obtained from the software analysis.
1) Outlet temperature = 304 K: The outlet temperature
obtained from CFD analysis is close to calculated value 304.5
K. Contours of temperature is shown below in fig. 3.
Fig. 3 Contours of temperature distribution
2) Mass flow = 0.033 Kg/s:
Fig. 4 Contours of mass flow rate
Contours of mass flow rate is shown in fig. 4.
3) Velocity contours: Velocity contours shown in fig. 5
does not show much variations and are within limits. The DC
motor pump is capable to pump the water with sufficient
velocities to facilitate the heat transfer while the water comes
in contact with skin.
Fig. 5 Contours of velocity
B. Experimental Results
When experiments were done on the prototype made, the
cooling rates were noted at different conditions and the table 3
shows it.
5. International Journal For Research & Development in Technology
Volume: 1, Issue: 2, JUNE 2014 ISSN (Online):- 2349-3585
5 Copyright 2014- IJRDT www.ijrdt.org
TABLE III
RESULTS OF EXPERIMENTAL READINGS
Experimental results shown in table III are obtained by
monitoring the system against the pre-established time scale.
Readings are taken with the help of a digital thermo meter.
Cooling rate readings of single and merged modules are
compared against each other in the same time scale.
Thus it was found that when merged thermoelectric modules
were used the cooling rates have increased considerably. The
fabrication process involved trial and error use of
thermoelectric modules in merged and unmerged conditions
under various conditions. Merged modules always provides
higher heat removal rate. This will allow TEC to be made
from a number of small power modules. This will in turn
reduce the power consumption and the weight of the
assembly. Power consumption and weight are the two
governing parameters in the selection of microclimate cooling
system. Thus the proposed thermo electric cooling system is a
potential candidate in personal cooling systems.
III. CONCLUSIONS
The work carried out indicates that thermoelectric cooling
is a viable solution for controlling body core temperature for
individuals working in harsh environment. The experimental
data shows that use of more number of TEC modules
increases the rate of cooling.
As first phase a vest was designed considering the actual
situation and determined the design value. The value derived
was verified using CFD software and was found correct.
In the second phase the designed system was manufactured, in
which copper tubes are used instead of polymer and a
combination of two TEC modules are used. By carrying out
experiments on the prototype it is revealed that the prototype
is effective in lowering the temperature and the cooling rate is
increased by using merged modules. Considering the weight
and power requirements, the thermoelectric based
microclimate cooling vest is an effective alternative.
ACKNOWLEDGMENT
We place on record, our sincere gratitude to Er.
Muruganantham P, Professor & HOD, Department of
Mechanical Engineering, for his constant encourage.
We would like to express our whole hearted gratitude to Er.
Francis A J, Assistant Professor, Mechanical Engineering
Department for his valuable guidance and inspiration
throughout the course of this research. We also take this
opportunity to thank all staff members in the Mechanical
Department, Saintgits College of Engineering.
REFERENCES
(1) NIOSH, National Institution for Occupational Safety
and Health. "Occupational Exposure to Hot
Environments." U.S Department of Health and
Human Services, 1986: 1‐ 115.
(2) Yunus A. Cengel, Afshin J. Ghajar. “Heat and mass
transfer” volume 4, pp. 494-495
(3) Sophia D’Angelo. “The Cooling Vest - Evaporative
Cooling”, 2009 pp. 1-150
.
Time
Taken(Min)
Temperature Obtained (0
c)
Using Single
Module
Using Merged Module
Initially 30 30
10 28 25
15 26 22
20 24 19
25 21 17
30 19 15