- Historically, the Chinese were the first to store ice and snow for cooling. Jacob Perkins developed the first modern vapor-compression refrigeration system in 1834 using ether as the refrigerant. Ammonia and other refrigerants were used in the 1850s-1900s before halocarbon refrigerants like R-12 and R-22 became dominant in the 1930s.
- Modern refrigeration systems use the reverse Carnot cycle with a refrigerant changing phases during the cooling process. The type of refrigerant selected affects the system design, costs, safety, and environmental impacts.
This document discusses refrigerants and their properties. It begins with a brief history of refrigeration and then discusses key concepts like the refrigeration principle, what constitutes a refrigerant, chlorofluorocarbons (CFCs) and their impact on ozone depletion. It also summarizes the Montreal Protocol which phased out ozone depleting substances. Finally, it describes the basic vapor compression refrigeration system and important criteria for selecting refrigerants, including thermodynamic and environmental impact considerations.
The document discusses the history and principles of refrigeration and refrigerants. It describes how early refrigeration methods used natural ice and evaporation of liquids before Jacob Perkins developed the first vapor compression refrigeration system using ether as the refrigerant. Modern refrigeration is dominated by vapor compression cycles using halocarbon refrigerants. However, CFC refrigerants were found to deplete the ozone layer, leading to the Montreal Protocol that phased out their production. Selection of new refrigerants must consider thermodynamic properties as well as environmental safety.
This slide is about some new green cooling system (refrigeration system) and green refrigerant. For the Ozone layer depletion and green house effect, it is high time to find new refrigerant and refrigeration system.
Refrigerants are substances used in refrigeration cycles to absorb and remove heat from the space being refrigerated. The main types are primary and secondary refrigerants. Primary refrigerants directly cool spaces through phase change processes. Common primary refrigerants include ammonia, hydrocarbons, halocarbons like Freon, and inorganic substances. Secondary refrigerants indirectly cool spaces by transferring heat between the evaporator and load. Brines are commonly used secondary refrigerants. Refrigerants are designated by "R" numbers to identify their chemical composition and properties. Desirable properties include thermodynamic efficiency, safety, and minimal environmental impact as measured by ODP and GWP.
This document discusses refrigerants, including their classification, properties, environmental impacts, and alternatives. Refrigerants are heat carrying fluids that absorb heat from a low temperature system and release it to a high temperature system. Natural substances like ice were early refrigerants, followed by ether, ammonia, and sulfur dioxide in the 19th century. Chlorofluorocarbons (CFCs) became popular but were later banned due to ozone depletion and global warming. Current alternatives include hydrocarbons, ammonia, carbon dioxide, and hydrofluorocarbons. An ideal refrigerant has desirable properties like high critical temperature, low boiling point, non-toxicity, stability, and being environmentally friendly.
This document discusses refrigerants and their properties. It begins with a brief history of refrigeration and then discusses key concepts like the refrigeration principle, what constitutes a refrigerant, chlorofluorocarbons (CFCs) and their impact on ozone depletion. It also summarizes the Montreal Protocol which phased out ozone depleting substances. Finally, it describes the basic vapor compression refrigeration system and important criteria for selecting refrigerants, including thermodynamic and environmental impact considerations.
The document discusses the history and principles of refrigeration and refrigerants. It describes how early refrigeration methods used natural ice and evaporation of liquids before Jacob Perkins developed the first vapor compression refrigeration system using ether as the refrigerant. Modern refrigeration is dominated by vapor compression cycles using halocarbon refrigerants. However, CFC refrigerants were found to deplete the ozone layer, leading to the Montreal Protocol that phased out their production. Selection of new refrigerants must consider thermodynamic properties as well as environmental safety.
This slide is about some new green cooling system (refrigeration system) and green refrigerant. For the Ozone layer depletion and green house effect, it is high time to find new refrigerant and refrigeration system.
Refrigerants are substances used in refrigeration cycles to absorb and remove heat from the space being refrigerated. The main types are primary and secondary refrigerants. Primary refrigerants directly cool spaces through phase change processes. Common primary refrigerants include ammonia, hydrocarbons, halocarbons like Freon, and inorganic substances. Secondary refrigerants indirectly cool spaces by transferring heat between the evaporator and load. Brines are commonly used secondary refrigerants. Refrigerants are designated by "R" numbers to identify their chemical composition and properties. Desirable properties include thermodynamic efficiency, safety, and minimal environmental impact as measured by ODP and GWP.
This document discusses refrigerants, including their classification, properties, environmental impacts, and alternatives. Refrigerants are heat carrying fluids that absorb heat from a low temperature system and release it to a high temperature system. Natural substances like ice were early refrigerants, followed by ether, ammonia, and sulfur dioxide in the 19th century. Chlorofluorocarbons (CFCs) became popular but were later banned due to ozone depletion and global warming. Current alternatives include hydrocarbons, ammonia, carbon dioxide, and hydrofluorocarbons. An ideal refrigerant has desirable properties like high critical temperature, low boiling point, non-toxicity, stability, and being environmentally friendly.
Here from this presentation we will be getting an ample knowledge to know about Refrigerants, Classification of Refrigerants, different types of Refrigerants, different properties regarding refrigerants, different types of temperatures and all
Refrigerants___purpose and nomenclature with recent innovationsHashim Hasnain Hadi
The document discusses refrigerants used in refrigeration systems. It defines a refrigerant as a heat carrying medium that absorbs heat from a low temperature system and transfers it to a high temperature system through phase changes like evaporation and condensation. Refrigerants are classified as primary or secondary based on whether they undergo direct phase changes or transport energy indirectly. Common primary refrigerants discussed include halocarbons, hydrocarbons, azeotropes and inorganic refrigerants. Properties of ideal refrigerants and various refrigerant types are also outlined.
The document discusses refrigerants and their properties. It defines refrigerants as the primary working fluids used in refrigeration systems that absorb heat at low temperatures and release it at higher temperatures. Key properties of refrigerants include low boiling point, high latent heat, non-toxicity, and non-corrosiveness. The document also covers classifications of refrigerants such as halocarbon, azeotrope, inorganic, and hydrocarbons. Environmental impacts and economics are additional factors in refrigerant selection.
“Refrigerant is the media (fluid) used for heat transfer in a refrigerating system that absorbs heat during evaporation from the region of low temperature and pressure, and releases heat during condensation at a region of higher temperature and pressure.”
Alternative refrigerants are being developed to replace hydrofluorocarbons which have high global warming potential. Alternative refrigerants have significantly lower global warming potential and include ammonia, carbon dioxide, propane, and isobutane. Common alternative refrigerants are inorganic refrigerants like ammonia and carbon dioxide, hydrocarbon refrigerants like propane and butane, and azeotropic or zeotropic refrigerant blends. Ammonia has excellent thermodynamic properties and is a leading alternative, while carbon dioxide is useful for vehicles due to its high pressure and hydrocarbons are flammable but have good efficiency. Natural refrigerants like ammonia, hydrocarbons and carbon dioxide are better long term
The ppt contains detailed study of refrigerants used in refrigeration and air conditioning system with description. It is well formed as per the syllabus of GTU.
This document discusses heat transfer fluids used in concentrated solar power plants. It describes the main types of concentrated solar power plants including parabolic troughs, power towers, linear Fresnel technology, and dish Sterling systems. It then discusses ideal properties, types, and applications of commonly used heat transfer fluids. The main fluids discussed are water, hydrocarbons (oils), molten salts, glycol/water mixtures, and silicones. Ongoing research aims to develop heat transfer fluids with improved thermal stability at higher temperatures and lower freezing points.
Successive improvement of refrigerants in vapour compression refrigeration sy...Rahul Singh
This document discusses the history and development of refrigerants. It outlines how early refrigerants like CFCs and HCFCs were phased out due to their ozone depletion and global warming potential. Newer refrigerants like HFCs like R-134a were introduced but still have high GWP. Current natural refrigerants like ammonia, carbon dioxide, and hydrocarbons have zero ODP and low GWP making them more sustainable options. The document also examines future refrigerants like R-410A, R-424A, and R-426A which have no ozone depletion and are being widely adopted as replacements for past refrigerants.
This document discusses alternative refrigerants to halocarbons that deplete the ozone layer and contribute to global warming. It describes five main types of refrigerants - halocarbons, azeotropic, zeotropic, inorganic, and hydrocarbon refrigerants - and provides examples of each. The document recommends natural refrigerants like ammonia, hydrocarbons like propane, and carbon dioxide as more environmentally-friendly alternatives to halocarbons.
This document discusses the history of refrigerant and compressor development. It describes the early use of natural refrigerants like water and how synthetic refrigerants like Freon were developed in the 1920s. It also discusses the key issues with early refrigerants like toxicity and flammability that synthetic refrigerants solved. However, synthetic refrigerants like CFCs were later found to deplete the ozone layer, prompting a search for new non-ozone depleting refrigerants. The document provides a high-level overview of the major developments and issues in both refrigerants and compressor technology over time.
Refrigerants are substances that are used in heat transfer equipment to absorb and remove heat from the space being cooled. An ideal refrigerant has favorable thermodynamic properties, is non-toxic and non-corrosive. Common refrigerants include ammonia, hydrocarbons like propane, and fluorocarbons. Refrigerants work by undergoing phase changes in a vapor compression or absorption refrigeration cycle. They absorb heat in the evaporator and reject heat in the condenser. Properties like low boiling point, high heat of vaporization, and moderate pressures allow efficient heat transfer. [/SUMMARY]
HCl manufacturing salt sulphuric acid processjmrobert987
This document discusses the production and manufacturing of hydrochloric acid (HCl). HCl exists as a solution of hydrogen chloride gas in water and can exist in solid, liquid, and gas states. It has been produced since the 15th century through various methods. Today, the most common method is absorbing the hydrogen chloride by-product from other chemical manufacturing processes, such as chlorinating hydrocarbons. HCl is manufactured through processes like reacting salt and sulfuric acid, synthesizing from hydrogen and chlorine gas, absorbing by-products, and more. When produced from salt and sulfuric acid, the reactants are heated in a furnace to produce HCl gas and sodium sulfate as a byproduct. The hot H
Applications of Refrigeration and Air Conditioning & RefrigerantsNITIN AHER
This document discusses refrigeration and air conditioning. It describes how refrigeration cools products or spaces below the surrounding temperature, while air conditioning controls temperature, moisture, cleanliness, odor, and air circulation for occupants or processes. Common applications are listed such as room air conditioners, refrigerators, evaporative coolers, and commercial refrigeration/air conditioning. The document then focuses on evaporative cooling systems, automotive air conditioners, refrigerants used, and criteria for selecting refrigerants including thermodynamic properties, environmental impact, and safety.
Experimental Performance Evaluation of R152a to replace R134a in Vapour Compr...IJMER
The performance of heat transfer is one of the most important research areas in the field
of thermal engineering. There are a large number of refrigerants, which are used to transfer heat from
low temperature reservoir to high temperature reservoir by using vapour compression refrigeration
system. There are various obstacles faced in working of different refrigerants due to their environmental
impact (CFC, HCFC), toxicity (NH3), flammability (HC) and high pressure (CO2); which makes them
more hazardous than other working fluids according to safety and environmental issues.
Experimentation is conducted to observe the performance of Hydro-fluorocarbon (HFC) refrigerants
(R134a and R152a) in vapour compression refrigeration. Value of average refrigerating effect for R152a
is about 57% more than that of R134a . Average pressure ratio for R152a was 18.92% higher than that of
R134a. In this result, R152a has emerged as the most energy efficient refrigerant among both the
investigated refrigerants being the one that exhibited the lowest power consumption per ton of
refrigeration with the average value of 13.23% less than that of R134a.The COP of R152a obtain is
higher than R134a by 3.769% .As a result, R152a could be used as a drop-in replacement for R134a in
vapour compression refrigeration system. R152a offers the best desirable environmental requirements;
zero Ozone Depleting Potential (ODP) and 120 Global Warming Potential (GWP).
This document discusses replacing the refrigerant R134a with R152a in a vapor compression refrigeration system. It first provides background on vapor compression refrigeration systems and refrigerants such as R134a. It then summarizes an experiment comparing the performance of R134a and R152a. The results found that R152a had 57% higher refrigerating effect, 18.92% higher pressure ratio, and 13.23% lower power consumption than R134a. R152a also had a 3.769% higher COP than R134a. Therefore, the document concludes that R152a can be used as a drop-in replacement for R134a in vapor compression refrigeration systems as it has better environmental
Refrigeration is the process of removing heat from an object or space to lower its temperature below the surrounding environment. It uses refrigerants and works by continuously absorbing heat and rejecting it at higher temperatures. There are two main types of refrigeration systems - vapor compression, which uses a compressor, and vapor absorption, which uses heat to power the refrigeration process. Air conditioning builds on refrigeration to condition air for human comfort by controlling temperature and humidity levels. There are various types of air conditioning units and cooling towers that reject waste heat to cool water or air.
The document discusses refrigerants used in refrigeration systems. It defines a refrigerant as the medium that transfers heat by evaporating at a low temperature and pressure, and condensing at a higher temperature and pressure. The history of commonly used refrigerants is provided, from early experiments in the 1830s to modern refrigerants developed in the 1920s. Refrigerants are classified as primary or secondary, where primary refrigerants undergo phase changes directly in the system and secondary refrigerants transport thermal energy between locations. Key properties for refrigerants include chemical stability, safety, cost, efficiency and compatibility with system materials. Selection of a refrigerant depends on its thermodynamic, environmental and safety properties as well as economic
Geothermal energy can be used to generate electricity through binary cycle power plants. These plants utilize a secondary working fluid with a low boiling point, such as an organic fluid, that is heated by hot geothermal water or steam in a heat exchanger. The working fluid evaporates and drives a turbine that generates electricity. Binary cycle plants produce less emissions than traditional steam plants and can operate at lower geothermal reservoir temperatures. The selection of the working fluid considers factors like temperature range, density, viscosity, and environmental impact.
Experimental Study of R134a, R406A and R600a Blends as Alternative To Freon 12IOSR Journals
: In the vent of chlorofluorocarbons (CFCs) phase-out, identify long term alternative to meet
requirements in respect of system performance and service is an important area of research in the refrigeration
and are conditioning industry. This work focuses on experimental study of the performance of eco-friendly
refrigerant mixtures. Mixtures of three existing refrigerants namely: R600a (n-butane), R134a (1,1,
1,2,tetrafluoroethane) and R406A (55%R22/4%R600a/41%R142b)were considered for this research. These
refrigerants were mixed in various ratios, studied and compared with R-12 (dichlorodifluoromethane) which
was used as the control for the experimentation. The rig used in the experimentation is a 2 hp (1.492 kW)
domestic refrigerator, designed based on condensing and evaporating temperatures. The rig was
tested with R-12, and blends of the three refrigerants. During the experimentation, both evaporator and
condenser temperatures were measured. These were used to determine the heat absorbed in evaporator
and the heat rejected incondenser . The results show that R134a/R600a mixture in the ratio 50:50 can
be used as alternative to R-12 in domestic refrigerators, without the necessity of changing the compressor
lubricating oil. At and , R-12 gives a COP of 2.08 while 50:50 blend of R134a/R600a
gives a COP of 2.30 under the same operating conditions
Revolutionizing the Digital Landscape: Web Development Companies in Indiaamrsoftec1
Discover unparalleled creativity and technical prowess with India's leading web development companies. From custom solutions to e-commerce platforms, harness the expertise of skilled developers at competitive prices. Transform your digital presence, enhance the user experience, and propel your business to new heights with innovative solutions tailored to your needs, all from the heart of India's tech industry.
Here from this presentation we will be getting an ample knowledge to know about Refrigerants, Classification of Refrigerants, different types of Refrigerants, different properties regarding refrigerants, different types of temperatures and all
Refrigerants___purpose and nomenclature with recent innovationsHashim Hasnain Hadi
The document discusses refrigerants used in refrigeration systems. It defines a refrigerant as a heat carrying medium that absorbs heat from a low temperature system and transfers it to a high temperature system through phase changes like evaporation and condensation. Refrigerants are classified as primary or secondary based on whether they undergo direct phase changes or transport energy indirectly. Common primary refrigerants discussed include halocarbons, hydrocarbons, azeotropes and inorganic refrigerants. Properties of ideal refrigerants and various refrigerant types are also outlined.
The document discusses refrigerants and their properties. It defines refrigerants as the primary working fluids used in refrigeration systems that absorb heat at low temperatures and release it at higher temperatures. Key properties of refrigerants include low boiling point, high latent heat, non-toxicity, and non-corrosiveness. The document also covers classifications of refrigerants such as halocarbon, azeotrope, inorganic, and hydrocarbons. Environmental impacts and economics are additional factors in refrigerant selection.
“Refrigerant is the media (fluid) used for heat transfer in a refrigerating system that absorbs heat during evaporation from the region of low temperature and pressure, and releases heat during condensation at a region of higher temperature and pressure.”
Alternative refrigerants are being developed to replace hydrofluorocarbons which have high global warming potential. Alternative refrigerants have significantly lower global warming potential and include ammonia, carbon dioxide, propane, and isobutane. Common alternative refrigerants are inorganic refrigerants like ammonia and carbon dioxide, hydrocarbon refrigerants like propane and butane, and azeotropic or zeotropic refrigerant blends. Ammonia has excellent thermodynamic properties and is a leading alternative, while carbon dioxide is useful for vehicles due to its high pressure and hydrocarbons are flammable but have good efficiency. Natural refrigerants like ammonia, hydrocarbons and carbon dioxide are better long term
The ppt contains detailed study of refrigerants used in refrigeration and air conditioning system with description. It is well formed as per the syllabus of GTU.
This document discusses heat transfer fluids used in concentrated solar power plants. It describes the main types of concentrated solar power plants including parabolic troughs, power towers, linear Fresnel technology, and dish Sterling systems. It then discusses ideal properties, types, and applications of commonly used heat transfer fluids. The main fluids discussed are water, hydrocarbons (oils), molten salts, glycol/water mixtures, and silicones. Ongoing research aims to develop heat transfer fluids with improved thermal stability at higher temperatures and lower freezing points.
Successive improvement of refrigerants in vapour compression refrigeration sy...Rahul Singh
This document discusses the history and development of refrigerants. It outlines how early refrigerants like CFCs and HCFCs were phased out due to their ozone depletion and global warming potential. Newer refrigerants like HFCs like R-134a were introduced but still have high GWP. Current natural refrigerants like ammonia, carbon dioxide, and hydrocarbons have zero ODP and low GWP making them more sustainable options. The document also examines future refrigerants like R-410A, R-424A, and R-426A which have no ozone depletion and are being widely adopted as replacements for past refrigerants.
This document discusses alternative refrigerants to halocarbons that deplete the ozone layer and contribute to global warming. It describes five main types of refrigerants - halocarbons, azeotropic, zeotropic, inorganic, and hydrocarbon refrigerants - and provides examples of each. The document recommends natural refrigerants like ammonia, hydrocarbons like propane, and carbon dioxide as more environmentally-friendly alternatives to halocarbons.
This document discusses the history of refrigerant and compressor development. It describes the early use of natural refrigerants like water and how synthetic refrigerants like Freon were developed in the 1920s. It also discusses the key issues with early refrigerants like toxicity and flammability that synthetic refrigerants solved. However, synthetic refrigerants like CFCs were later found to deplete the ozone layer, prompting a search for new non-ozone depleting refrigerants. The document provides a high-level overview of the major developments and issues in both refrigerants and compressor technology over time.
Refrigerants are substances that are used in heat transfer equipment to absorb and remove heat from the space being cooled. An ideal refrigerant has favorable thermodynamic properties, is non-toxic and non-corrosive. Common refrigerants include ammonia, hydrocarbons like propane, and fluorocarbons. Refrigerants work by undergoing phase changes in a vapor compression or absorption refrigeration cycle. They absorb heat in the evaporator and reject heat in the condenser. Properties like low boiling point, high heat of vaporization, and moderate pressures allow efficient heat transfer. [/SUMMARY]
HCl manufacturing salt sulphuric acid processjmrobert987
This document discusses the production and manufacturing of hydrochloric acid (HCl). HCl exists as a solution of hydrogen chloride gas in water and can exist in solid, liquid, and gas states. It has been produced since the 15th century through various methods. Today, the most common method is absorbing the hydrogen chloride by-product from other chemical manufacturing processes, such as chlorinating hydrocarbons. HCl is manufactured through processes like reacting salt and sulfuric acid, synthesizing from hydrogen and chlorine gas, absorbing by-products, and more. When produced from salt and sulfuric acid, the reactants are heated in a furnace to produce HCl gas and sodium sulfate as a byproduct. The hot H
Applications of Refrigeration and Air Conditioning & RefrigerantsNITIN AHER
This document discusses refrigeration and air conditioning. It describes how refrigeration cools products or spaces below the surrounding temperature, while air conditioning controls temperature, moisture, cleanliness, odor, and air circulation for occupants or processes. Common applications are listed such as room air conditioners, refrigerators, evaporative coolers, and commercial refrigeration/air conditioning. The document then focuses on evaporative cooling systems, automotive air conditioners, refrigerants used, and criteria for selecting refrigerants including thermodynamic properties, environmental impact, and safety.
Experimental Performance Evaluation of R152a to replace R134a in Vapour Compr...IJMER
The performance of heat transfer is one of the most important research areas in the field
of thermal engineering. There are a large number of refrigerants, which are used to transfer heat from
low temperature reservoir to high temperature reservoir by using vapour compression refrigeration
system. There are various obstacles faced in working of different refrigerants due to their environmental
impact (CFC, HCFC), toxicity (NH3), flammability (HC) and high pressure (CO2); which makes them
more hazardous than other working fluids according to safety and environmental issues.
Experimentation is conducted to observe the performance of Hydro-fluorocarbon (HFC) refrigerants
(R134a and R152a) in vapour compression refrigeration. Value of average refrigerating effect for R152a
is about 57% more than that of R134a . Average pressure ratio for R152a was 18.92% higher than that of
R134a. In this result, R152a has emerged as the most energy efficient refrigerant among both the
investigated refrigerants being the one that exhibited the lowest power consumption per ton of
refrigeration with the average value of 13.23% less than that of R134a.The COP of R152a obtain is
higher than R134a by 3.769% .As a result, R152a could be used as a drop-in replacement for R134a in
vapour compression refrigeration system. R152a offers the best desirable environmental requirements;
zero Ozone Depleting Potential (ODP) and 120 Global Warming Potential (GWP).
This document discusses replacing the refrigerant R134a with R152a in a vapor compression refrigeration system. It first provides background on vapor compression refrigeration systems and refrigerants such as R134a. It then summarizes an experiment comparing the performance of R134a and R152a. The results found that R152a had 57% higher refrigerating effect, 18.92% higher pressure ratio, and 13.23% lower power consumption than R134a. R152a also had a 3.769% higher COP than R134a. Therefore, the document concludes that R152a can be used as a drop-in replacement for R134a in vapor compression refrigeration systems as it has better environmental
Refrigeration is the process of removing heat from an object or space to lower its temperature below the surrounding environment. It uses refrigerants and works by continuously absorbing heat and rejecting it at higher temperatures. There are two main types of refrigeration systems - vapor compression, which uses a compressor, and vapor absorption, which uses heat to power the refrigeration process. Air conditioning builds on refrigeration to condition air for human comfort by controlling temperature and humidity levels. There are various types of air conditioning units and cooling towers that reject waste heat to cool water or air.
The document discusses refrigerants used in refrigeration systems. It defines a refrigerant as the medium that transfers heat by evaporating at a low temperature and pressure, and condensing at a higher temperature and pressure. The history of commonly used refrigerants is provided, from early experiments in the 1830s to modern refrigerants developed in the 1920s. Refrigerants are classified as primary or secondary, where primary refrigerants undergo phase changes directly in the system and secondary refrigerants transport thermal energy between locations. Key properties for refrigerants include chemical stability, safety, cost, efficiency and compatibility with system materials. Selection of a refrigerant depends on its thermodynamic, environmental and safety properties as well as economic
Geothermal energy can be used to generate electricity through binary cycle power plants. These plants utilize a secondary working fluid with a low boiling point, such as an organic fluid, that is heated by hot geothermal water or steam in a heat exchanger. The working fluid evaporates and drives a turbine that generates electricity. Binary cycle plants produce less emissions than traditional steam plants and can operate at lower geothermal reservoir temperatures. The selection of the working fluid considers factors like temperature range, density, viscosity, and environmental impact.
Experimental Study of R134a, R406A and R600a Blends as Alternative To Freon 12IOSR Journals
: In the vent of chlorofluorocarbons (CFCs) phase-out, identify long term alternative to meet
requirements in respect of system performance and service is an important area of research in the refrigeration
and are conditioning industry. This work focuses on experimental study of the performance of eco-friendly
refrigerant mixtures. Mixtures of three existing refrigerants namely: R600a (n-butane), R134a (1,1,
1,2,tetrafluoroethane) and R406A (55%R22/4%R600a/41%R142b)were considered for this research. These
refrigerants were mixed in various ratios, studied and compared with R-12 (dichlorodifluoromethane) which
was used as the control for the experimentation. The rig used in the experimentation is a 2 hp (1.492 kW)
domestic refrigerator, designed based on condensing and evaporating temperatures. The rig was
tested with R-12, and blends of the three refrigerants. During the experimentation, both evaporator and
condenser temperatures were measured. These were used to determine the heat absorbed in evaporator
and the heat rejected incondenser . The results show that R134a/R600a mixture in the ratio 50:50 can
be used as alternative to R-12 in domestic refrigerators, without the necessity of changing the compressor
lubricating oil. At and , R-12 gives a COP of 2.08 while 50:50 blend of R134a/R600a
gives a COP of 2.30 under the same operating conditions
Revolutionizing the Digital Landscape: Web Development Companies in Indiaamrsoftec1
Discover unparalleled creativity and technical prowess with India's leading web development companies. From custom solutions to e-commerce platforms, harness the expertise of skilled developers at competitive prices. Transform your digital presence, enhance the user experience, and propel your business to new heights with innovative solutions tailored to your needs, all from the heart of India's tech industry.
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- Clean Energy Plans?!
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- The business case for Passive House real estate
- Tools to quantify the value of Passive House
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ARENA - Young adults in the workplace (Knight Moves).pdfKnight Moves
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CapCut is an easy-to-use video editing app perfect for beginners. To start, download and open CapCut on your phone. Tap "New Project" and select the videos or photos you want to edit. You can trim clips by dragging the edges, add text by tapping "Text," and include music by selecting "Audio." Enhance your video with filters and effects from the "Effects" menu. When you're happy with your video, tap the export button to save and share it. CapCut makes video editing simple and fun for everyone!
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2. History Of Refrigeration
• Most evidence indicate that the Chinese were the first to store
natural ice and snow to cool wine and other delicacies.
• Ancient people of India and Egypt cooled liquids in porous earthen
jars.
• In 1834, Jacob Perkins, an American, developed a closed
refrigeration system using liquid expansion and then compression to
produce cooling.
He used Ether as refrigerant, in a hand- operated compressor, a
water-cooled condenser and an evaporator in liquid cooler.
1850’s – 1870’s: ammonia, ammonia/water, CO2
Early 1900’s: SO2, methyl chloride used for domestic refrigerators
1930’s: halocarbon refrigerants (R-12, R-22, R-114, R-22)
Halocarbon advantages – stable compounds, favorable thermodynamic
properties, safer than existing refrigerants.
3. Refrigeration Principle
• Modern refrigeration and air-conditioning
equipment is dominated by vapour compression
refrigeration technology built upon the
thermodynamic principles of the reverse Carnot
cycle.
• Refrigerant Changes phase during cooling and used
again and again.
4. Importance of Refrigerant
• The thermodynamic efficiency of a refrigeration
system depends mainly on its operating temperatures.
• However, important practical issues such as the
system design, size, initial and operating costs,
safety, reliability, and serviceability etc. depend very
much on the type of refrigerant selected for a given
application.
• Due to several environmental issues such as ozone
layer depletion and global warming and their relation
to the various refrigerants used, the selection of
suitable refrigerant has become one of the most
important issues in recent times.
5. What is a Refrigerant
• Working substances
• Primary and Secondary refrigerants.
• Primary refrigerants are those fluids, which are used directly
as working fluids.
Ex.-refrigerant used in VCC and VAR systems.
These fluids provide refrigeration by undergoing a phase
change process in the evaporator.
• Secondary refrigerants are those liquids, which are used for
transporting thermal energy from one location to other.
•
Secondary refrigerants are also known under the name
brines or antifreezes.
6. • The refrigerants which are directly used to
obtain the cooling effect in evaporator by
undergoing a phase change process are referred
as Primary refrigerants.
• Halocarbon Refrigerants
• Azeotropes Refrigerants
• Inorganic Refrigerants
• Hydro-carbon Refrigerants
Primary Refrigerant
7. • Used for transporting thermal energy from one
location to other.
• Does not undergo phase change process.
• Used when refrigeration is required at sub-zero
temperatures.
• Known as Brines or Antifreezes.
• Used in large refrigeration units.
• Commonly used secondary refrigerants are:-
Solution of water & ethylene glycol, propylene
glycol etc.
Secondary Refrigerant
8. • If working temperature is above 30C, Water is used as SR.
• Brine is aqueous solution of NaCl and CaCl2 in water and used
at temperature below freezing point of water 00C.
Used in cooling of fish, meat & ice plant.
• Ethylene glycol & Propylene glycol mixes with water and gives
colorless & odourless solutions.
These have capacity to lower freezing temperatures and
hence used as antifreeze mixtures for I.C. engine cooling
systems.
These solutions become corrosive after some use, hence
corrosive treatment is necessary.
Secondary Refrigerant
9. • Different rooms of building can be cooled up to
different temperatures by adjusting the flow
rates of secondary refrigerants.
• SR can be easily handled.
• SR can be easily controlled.
• Eliminates long refrigeration lines and thus
reduces pressure drops.
Advantages of Secondary
Refrigerant
10. • Low freezing point.
• High heat transfer coefficients.
• High specific heat.
• Low vapour pressure.
• Good stability.
• Non-flammable and non-toxic.
Desirable Properties of
Secondary Refrigerant
12. • CFC’s
First developed by General Motor’s researchers in the 1920’s
and commercialized as Freon‘s.
Most stable – remain in atmosphere for many years, allowing them
to diffuse to high altitudes
Contains Chlorine, Fluorine, Carbon.
CFC’s break down, and Cl combines with and consumes some ozone
• HCFC’s
Hydrogenated
Not as stable – most of it breaks down before reaching high
altitudes
Contains Hydrogen, Chlorine, Fluorine, Carbon.
Less damaging to ozone
• HFC’s
Contains Hydrogen, Fluorine, Carbon.
Contains no Cl (Chlorine)
Causes no depletion of ozone
Primary Refrigerant
13. Halocarbon Refrigerants
• Synthetically produced (Derived from Methane , Ethane) and were
developed as the Freon family of refrigerants.
• Commonly used in Domestic, Commercial and Industrial Purposes due to
their wide range of boiling points at atmospheric pressure.
• Presence of fluorine makes it Non-toxic.
• Ozone unfriendly refrigerants.
15. • A stable mixture of two or several refrigerants whose
vapour and liquid phases retain identical compositions over a
wide range of temperatures.
• Thermodynamic properties remains fixed.
• Code starts with digit 5.
Examples
R500 – mixture of 73.8% of R12 and 26.2% of R152
R502 – Mixture of 49% of R22 and 51% of R115
Azeotrope (Mixed)
Refrigerants
16. Zeotropic Refrigerants
• A zeotropic mixture is one whose composition in liquid phase
differs to that in vapour phase.
• Zeotropic refrigerants therefore do not boil at constant
temperatures unlike azeotropic refrigerants.
Examples :
R404a : R125/143a/134a (44%,52%,4%)
R407c : R32/125/134a (23%, 25%, 52%)
R410a : R32/125 (50%, 50%)
R413a : R600a/218/134a (3%, 9%, 88%)
17. • Before Halocarbons, Natural refrigerants are extensively
used.
• Designated by R followed by Number.
Number = 700 + M
Example
Carbon Dioxide , Water , Ammonia , Air , Sulphur dioxide
R717 - (NH3)Ammonia
717 = 700 + 17
Inorganic (Natural)
Refrigerants
18. • Satisfactory Thermodynamic properties.
• Extraordinary reliability- The most convincing argument is the reliability of
the hydrocarbon system because of fewer compressor failures.
• .
• Virtually no refrigerant losses.
• Hydrocarbons have been used since the beginning of the century and now
being considered as long term solutions to environmental problems.
• But most of the hydrocarbons are highly flammable and require additional
safety precaution during its use as refrigerants
• Not used in Industry and commercial installations.
• Dominant in domestic market like household refrigerators and freezers
• Growing use in very small commercial systems like car air-conditioning
system.
Examples:
R170 – Ethane (C2H6)
R600 – Butane (C4H10)
R600a – Isobutane (C4H10)
Hydro-carbon Refrigerants
19. Current/Future
Refrigerants
• R-134a has emerged as the primary substitution for
many CFC’s.
• HCFC-22 and HCFC–123 are viable alternatives for
now but will eventually be phased out.
• In Europe, natural refrigerants such as ammonia,
CO2, propane, and water are being used more.
• Our legal system makes flammable refrigerants
questionable in the US.
20. Environmental Effects of
Refrigerants
Global warming :
Refrigerants directly contributing to global warming when
released to the atmosphere.
Indirect contribution based on the energy consumption of
among others the compressors ( CO2 produced by power
stations ).
Ozone Depletion:
NOTE THAT GLOBAL WARMING AND
OZONE DEPLETION ARE DIFFERENT
PROBLEMS WITH DIFFERENT
CAUSES. (A lot of people mess up on
this on exams.)
21. What is Ozone Layer
• Ozone (O3) is an isotope of oxygen with three atoms instead of
normal two.
• It is naturally occurring gas which is created by high energy
radiation from the Sun.
• The greatest concentration of ozone are found from 12 km to 50
km above the earth forming a layer in the stratosphere which is
called the ozone layer.
• This layer, which forms a semi-permeable blanket, protects the
earth by reducing the intensity of harmful ultra-violet (UV)
radiation from the sun.
22. Ozone Layer Depletion
• In the early70’s,scientists Sherwood Roland and
Mario Molina at the University of California at
Irvine were the first to discover the loss of ozone
in stratosphere while investigating the ozone layer
from highflying aircraft and spacecraft.
• They postulated the theory that exceptionally
stable chlorine containing fluorocarbons could,
overtime, migrate to the upper reaches of the
atmosphere and be broken by the intense
radiation and release chlorine atoms responsible
for catalytic ozone depletion.
23. OZONE LAYER DEPLETION
N0RMAL REACTION
O2 = O + O
O2 + O = O3
• But CFC refrigerants leaked during the manufacturing and normal
operation or at the time of servicing or repair, mix with
surrounding air and rise to troposphere and then into stratosphere
due to normal wind or storm.
• The Ultraviolet rays act on CFC releasing Cl atom, which retards the
normal reaction:
RETARDED REACTION
O3 = O2 + O
CCL2F2 = CCLF2 + CL
O3 + CL = CLO + O2
24. Harmful consequences of
ozone depletion
• For Humans
– Increase in skin cancer
– slow blindness
– Cataracts
• Less immunity to
– infectious diseases - malaria -herpes
• For plants
– smaller size -lower yield -increased toxicity
– altered form
• For marine life
– Reduced plankton -juvenile fish
– larval crabs and shrimps
25. Refrigerant selection
criteria
• Selection of refrigerant for a particular application
is based on the following requirements:
– Thermodynamic and thermo-physical properties
– Environmental and safety properties
– Economics
26. Thermodynamic and
thermo-physical properties
The requirements are:
a) Suction pressure:
At a given evaporator temperature, the saturation pressure should be
above atmospheric for prevention of air or moisture ingress into the
system and ease of leak detection.
Higher suction pressure is better as it leads to smaller compressor
displacement.
b) Discharge pressure:
At a given condenser temperature, the discharge pressure should be as
small as possible to allow light-weight construction of compressor,
condenser etc.
c) Pressure ratio:
Should be as small as possible for high volumetric efficiency and low
power consumption.
27. Thermodynamic and
thermo-physical properties
d) Latent heat of vaporization:
Should be as large as possible so that the required mass flow rate per
unit cooling capacity will be small.
In addition to the above properties; the following properties are
also important:
e) Isentropic index of compression:
Should be as small as possible so that the temperature rise during
compression will be small.
f) Liquid specific heat:
Should be small so that degree of sub cooling will be large leading to
smaller amount of flash gas at evaporator inlet.
g) Vapour specific heat:
Should be large so that the degree of superheating will be
small.
28. h) Thermal conductivity:
Thermal conductivity in both liquid as well as vapour phase should be
high for higher heat transfer coefficients .
i) Viscosity:
Viscosity should be small in both liquid and vapour phases for smaller
frictional pressure drops.
• The thermodynamic properties are interrelated and
mainly depend on normal boiling point, critical
temperature, molecular weight and structure.
Thermodynamic and
thermo-physical properties
29. Environmental and safety
properties
• At present the environment friendliness of the refrigerant is
a major factor in deciding the usefulness of a particular
refrigerant.
• The important environmental and safety properties are:
• a) Ozone Depletion Potential (ODP):
According to the Montreal protocol, the ODP of refrigerants should be
zero, i.e., they should be non-ozone depleting substances.
Refrigerants having non-zero ODP have either already been phased-out
(e.g. R 11, R 12) or will be phased-out in near-future(e.g. R22).
Since ODP depends mainly on the presence of chlorine or bromine in
the molecules, refrigerants having either chlorine (i.e., CFCs and
HCFCs) or bromine cannot be used under the new regulations.
30. Environmental and safety
properties
b) Global Warming Potential (GWP):
Refrigerants should have as low a GWP value as possible to minimize the
problem of global warming.
Refrigerants with zero ODP but a high value of GWP (e.g. R134a) are
likely to be regulated in future.
c) Total Equivalent Warming Index (TEWI):
The factor TEWI considers both direct (due to release into atmosphere)
and indirect (through energy consumption) contributions of refrigerants
to global warming.
Naturally, refrigerants with as a low a value of TEWI are preferable
from global warming point of view.
31. d) Toxicity:
Ideally, refrigerants should be non-toxic.
Toxicity is a relative term, which becomes meaningful only when the
degree of concentration and time of exposure required to produce
harmful effects are specified.
In general the degree of hazard depends on:
- Amount of refrigerant used vs total space
- Type of occupancy
- Presence of open flames
- Odor of refrigerant, and
– - Maintenance condition
Environmental and safety
properties
32. e) Flammability:
The refrigerants should preferably be non-flammable and non-explosive.
For flammable refrigerants special precautions should be taken to avoid
accidents.
f) Chemical stability:
The refrigerants should be chemically stable as long as they are inside
the refrigeration system.
g) Compatibility with common materials of construction (both metals
and non-metals)
Environmental and safety
properties
33. h) Miscibility with lubricating oils:
Oil separators have to be used if the refrigerant is not miscible with
lubricating oil (e.g. ammonia).
Refrigerants that are completely miscible with oils are easier to
handle(R12).
i) Ease of leak detection:
In the event of leakage of refrigerant from the system, it
should be easy to detect the leaks.
Environmental and safety
properties
34. • The refrigerant used should preferably be
inexpensive and easily available.
Economic Properties
36. Application of New Eco-friendly
Refrigerants
• Application HFCs used Possible
Eco-friendly refrigerant
•
• Domestic refrigeration R134a,R152a HC600a and blends
• Commercial refrigeration R134a,R404A,R407C HC blends,NH3 ,CO2 **
• Cold storage ,food processing
• And industrial refrigeration R134a,R404A,R507A NH3 ,HCs,CO2 **
• Unitary air conditioners R410A,R407C CO2 , HC s
• Centralized AC (chillers) R134a,R410A,R407C NH3 ,HCs,CO2, water **
• Transport refrigeration R134a,R404A CO 2,
• Mobile air conditioner R134a CO2 ,HCs
• Heat pumps R134a,R152a,R404A NH3 ,HCs,CO2, water **
• R407C,R410A
37. R22
• ODP-0.05, GWP-1700
• R22 has 40% more refrigerating capacity
• Higher pressure and discharge temp and not
suitable for low temp application
• Extensively used in commercial air-conditioning
and frozen food storage and display cases
38. R123
• ODP-0.02,GWP-90
• As a replacement for R11 as similar
thermodynamic properties.
• Very short atmospheric life
• Retrofit alternative to R11
39. R134a
• ODP-0, GWP-1300
• Used as a substitute for R12 and to a limited
range for R22
• Good performance in medium and high temp
application
• Toxicity is very low
• Not miscible with mineral oil
40. R152a
• ODP-0,GWP-140
• R152a is another attractive HFC with similar
properties to R12.
• GWP is one order less than HFC134a but it is
slightly flammable.
• Also it has lower energy consumption. Hence the
Environmental Protection Agency of Europe
prefers HFC152a to HFC134a
41. R290
• ODP-0,GWP-3
• Compatible with copper.
• Miscible with mineral oil
• Highest latent heat and largest vapour density
• A third of original charge only is required when
replacing halocarbons refrigerant in existing
equipment
• Energy saving : up to 20% due to lower molecular
mass and vapour pressure
42. R 600a
• ODP-0,GWP-3
• Higher boiling point hence lower evaporator
pressure
• Discharge temp is lowest
• Very good compatibility with mineral oil
43. Carbon Dioxide
• Zero ODP & GWP
• Non Flammable, Non toxic
• Inexpensive and widely available
• Its high operating pressure provides potential for system
size and weight reducing potential.
Drawbacks:
• Operating pressure (high side) : 80 bars
• Low efficiency
44. Ammonia – A Natural Refrigerant
Ammonia is produced in a natural way by human
beings and animals; 17 grams/day for humans.
Natural production 3000 million tons/year
Production in factories 120 million tons/year
Used in refrigeration 6 million tons/year
Ammonia as Refrigerant
45. Ammonia as Refrigerant
• ODP = 0 and GWP = 0
• Excellent thermodynamic characteristics: small molecular
mass, large latent heat, large vapour density and excellent
heat transfer characteristics
• High critical temperature (132C) : highly efficient cycles at
high condensing temperatures
• Its smell causes leaks to be detected and fixed before
reaching dangerous concentration
• Relatively Low price
46. Some Drawbacks of
Ammonia as Refrigerant
• Toxic
• Flammable ( 16 – 28% concentration )
• Not compatible with copper
• Temperature on discharge side of compressor is higher
compared to other refrigerants
47. Water
• Zero ODP & GWP
• Water as refrigerant is used in
absorption system .New developing
technology has created space for it
for use in compression cycles also.
• But higher than normal working
pressure in the system can be a
factor in restricted use of water as
refrigerant
48. Freon Group Refrigerants Application and ODP
Values
Refrigerant Areas of Application ODP
CFC 11(R11)
CFC 12 ( R 12 )
CFC 13 (R 13)
CFC113 (R113 )
CFC114 (R114 )
Blend of R22
and R115
(R502)
Air-conditioning Systems ranging from 200 to
2000 tons in capacity. It is used where low
freezing point and non-corrosive properties are
important.
It is used for most of the applications. Air-
conditioning plants, refrigerators, freezers, ice-
cream cabinets, water coolers, window air-
conditioners, automobile air conditioners.
For low temp refrigeration up to – 90 C in
cascade system
Small to medium air-conditioning system and
industrial cooling
In household refrigerators and in large industrial
cooling
Frozen food ice-cream display cases and
warehouses and food freezing plants. An
excellent general low temp refrigerant
1.0
1.0
1.0
1.07
0.8
0.34
49. General Safety measures for
refrigerating plants
• Reduction of refrigerant contents:
– Components with reduced contents
– Indirect systems with secondary refrigerant: distinction
between generation and transport of cold
• Scheduled maintenance and leak testing
• Governmental surveillance – Refrigerant Audits for
systems operating with HFC’s. Recovery, Stock of used
refrigerants, Recycling of refrigerants.
• For the Netherlands, the combined measures resulted in a
leak rate reduction of 35% (1995) to 8% (2001) for R22-
systems
50.
51. MONTREAL PROTOCOL
• SIGNED IN 1987 UNDER THE ‘UNEP’(United nations
environment programme ), AFTER MUCH DISCUSSIONS
• MORE THAN 170 COUNTRIES HAVE RATIFIED
• INDIA RATIFIED ON SEPT 17,1992
• ONE OF MOST SUCCESSFUL EXAMPLE OF
INTERNATIONAL COOPERATION IN UN HISTORY
52. Montreal protocol- Control
Schedule
Ozone depleting
substance
Developed countries Developing countries
CFCs phased out end of
1995
total phase out by
2010
halons phased out end of
1993
total phase out by
2010
HCFCs total phase out by
2020
total phase out by
2040