The document discusses refrigeration systems used in aircraft. It describes several types of air refrigeration systems:
1) Simple systems use compressed air cooled by a turbine-driven fan for ground cooling.
2) Bootstrap systems add a secondary compressor driven by the turbine to increase cooling capacity for high-speed aircraft.
3) Regenerative systems further cool air in a secondary heat exchanger using bled refrigerated air.
4) Reduced ambient systems use two turbines, one for cabin air and one for cooling air, driven by a single fan to cool air below ambient temperatures for supersonic aircraft.
Need for cooling of an aircraft. types of air-refrigeration system, DART, Advantages of air refrigeration system, Open and closed cycle air refrigeration,
Aircraft refrigeration system (air cooling system)Ripuranjan Singh
Aircraft air refrigeration systems are required due to heat transfer from many external and internal heat sources (like solar radiation and avionics) which increase the cabin air temperature. With the technological developments in high-speed passenger and jet aircraft's, the air refrigeration systems are proving to be most efficient, compact and simple. Various types of aircraft air refrigeration systems used these days are.
Simple air cooling system
Simple air evaporative cooling system
Boot strap air cooling system
Boot strap air evaporative cooling system
Reduced ambient air cooling system
Regenerative air cooling system
COMPRESSOR EFFICIENCY AND TURBINE EFFICIENCY.
Comparison of Various Air Cooling Systems used for Aircraft ON basis of dart
The document summarizes the key components and process of a vapor compression refrigeration system. It consists of 4 main components: an evaporator, compressor, condenser, and expansion valve. The refrigerant is evaporated in the evaporator, compressed to high pressure in the compressor, condensed to liquid in the condenser, then expanded to low pressure through the expansion valve before repeating the cycle. The system uses the phase change of refrigerants to absorb heat in the evaporator and reject heat in the condenser to achieve refrigeration. Common refrigerants used include chlorofluorocarbons.
The document describes the key components of a boiler system. It discusses 7 essential boiler mountings: 1) water level indicator, 2) main steam stop valve, 3) pressure gauge, 4) feed check valve, 5) fusible plug, 6) blow down valve, and 7) safety valve. It then provides more detailed descriptions and diagrams of the blow down valve, fusible plug, feed check valve, water level indicator, main steam stop valve, pressure gauge, and safety valve, explaining their purposes and functions within the boiler system.
The ppt contains detailed study of Vapor Absorption Refrigeration System with neat sketches and description. It is well formed as per the syllabus of GTU
Subcooling is cooling liquid refrigerant below its saturation temperature at constant pressure in the condenser, which keeps it fully liquid and improves cycle efficiency. Superheating heats the vapor in the evaporator so it enters the compressor as a vapor rather than liquid-vapor mixture, but increases compressor work and reduces capacity. Both processes impact the refrigeration cycle efficiency and capacity.
Refrigerators and heat pumps transfer heat from a low-temperature medium to a high-temperature medium. They differ only in their objectives - refrigerators remove heat (cooling), while heat pumps supply heat.
The vapor-compression cycle is the most common refrigeration cycle. It involves four main components: evaporator, compressor, condenser, and expansion valve. Heat is absorbed in the evaporator and rejected in the condenser. The compressor raises the refrigerant pressure and temperature between these components.
The performance of vapor-compression refrigeration systems depends on factors like evaporator/condenser temperatures and pressures. Actual cycles are less efficient than ideal cycles due to irreversibilities like heat transfer across a temperature
The document discusses refrigeration systems used in aircraft. It describes several types of air refrigeration systems:
1) Simple systems use compressed air cooled by a turbine-driven fan for ground cooling.
2) Bootstrap systems add a secondary compressor driven by the turbine to increase cooling capacity for high-speed aircraft.
3) Regenerative systems further cool air in a secondary heat exchanger using bled refrigerated air.
4) Reduced ambient systems use two turbines, one for cabin air and one for cooling air, driven by a single fan to cool air below ambient temperatures for supersonic aircraft.
Need for cooling of an aircraft. types of air-refrigeration system, DART, Advantages of air refrigeration system, Open and closed cycle air refrigeration,
Aircraft refrigeration system (air cooling system)Ripuranjan Singh
Aircraft air refrigeration systems are required due to heat transfer from many external and internal heat sources (like solar radiation and avionics) which increase the cabin air temperature. With the technological developments in high-speed passenger and jet aircraft's, the air refrigeration systems are proving to be most efficient, compact and simple. Various types of aircraft air refrigeration systems used these days are.
Simple air cooling system
Simple air evaporative cooling system
Boot strap air cooling system
Boot strap air evaporative cooling system
Reduced ambient air cooling system
Regenerative air cooling system
COMPRESSOR EFFICIENCY AND TURBINE EFFICIENCY.
Comparison of Various Air Cooling Systems used for Aircraft ON basis of dart
The document summarizes the key components and process of a vapor compression refrigeration system. It consists of 4 main components: an evaporator, compressor, condenser, and expansion valve. The refrigerant is evaporated in the evaporator, compressed to high pressure in the compressor, condensed to liquid in the condenser, then expanded to low pressure through the expansion valve before repeating the cycle. The system uses the phase change of refrigerants to absorb heat in the evaporator and reject heat in the condenser to achieve refrigeration. Common refrigerants used include chlorofluorocarbons.
The document describes the key components of a boiler system. It discusses 7 essential boiler mountings: 1) water level indicator, 2) main steam stop valve, 3) pressure gauge, 4) feed check valve, 5) fusible plug, 6) blow down valve, and 7) safety valve. It then provides more detailed descriptions and diagrams of the blow down valve, fusible plug, feed check valve, water level indicator, main steam stop valve, pressure gauge, and safety valve, explaining their purposes and functions within the boiler system.
The ppt contains detailed study of Vapor Absorption Refrigeration System with neat sketches and description. It is well formed as per the syllabus of GTU
Subcooling is cooling liquid refrigerant below its saturation temperature at constant pressure in the condenser, which keeps it fully liquid and improves cycle efficiency. Superheating heats the vapor in the evaporator so it enters the compressor as a vapor rather than liquid-vapor mixture, but increases compressor work and reduces capacity. Both processes impact the refrigeration cycle efficiency and capacity.
Refrigerators and heat pumps transfer heat from a low-temperature medium to a high-temperature medium. They differ only in their objectives - refrigerators remove heat (cooling), while heat pumps supply heat.
The vapor-compression cycle is the most common refrigeration cycle. It involves four main components: evaporator, compressor, condenser, and expansion valve. Heat is absorbed in the evaporator and rejected in the condenser. The compressor raises the refrigerant pressure and temperature between these components.
The performance of vapor-compression refrigeration systems depends on factors like evaporator/condenser temperatures and pressures. Actual cycles are less efficient than ideal cycles due to irreversibilities like heat transfer across a temperature
There are 5 main methods of supercharging internal combustion engines:
1) The compressor is driven directly by the engine using a belt or gears.
2) The compressor is driven by an exhaust gas turbine, with no direct mechanical connection to the engine. This is known as a turbocharger.
3) The compressor is driven by an external power source separate from the engine.
4) The engine drives both the compressor and a free turbine, with the turbine power used for an external load. This is known as a generator type supercharging.
5) The engine, compressor, and turbine are all directly coupled together using gears, with the turbine helping to drive the compressor under part load conditions on the engine
The document discusses the history and principles of vapor absorption refrigeration systems. Some key points:
- Vapor absorption was first discovered in 1824 by Michael Faraday and the first machine was built in 1860. It uses a refrigerant (ammonia) that is absorbed into a solvent (water) for compression.
- Unlike vapor compression, it uses heat rather than mechanical energy to change the refrigerant's state. This allows it to be powered by waste heat or solar energy.
- The first domestic refrigerator using this technology was invented in 1925 and used ammonia, hydrogen, and water in a "three-fluid" system to eliminate the need for a pump.
Refrigeration and air conditioning systems work by removing heat from an enclosed space to lower its temperature below the surrounding environment. There are two main types of refrigeration systems - vapor compression cycles and vapor absorption cycles. Vapor compression cycles use a compressor, condenser, expansion valve, and evaporator to remove heat. Vapor absorption cycles use heat to drive the refrigeration process rather than electricity. Air conditioning systems build on refrigeration principles to simultaneously control temperature, humidity, air motion, and quality within an enclosed space.
This document discusses multi-pressure refrigeration systems. It explains that single-stage systems have limitations at very low evaporator or high condenser temperatures due to increased losses. Multi-stage systems address this by using multiple compression stages to reduce the temperature lift in each stage. Types of multi-stage systems include multi-compression, multi-evaporator, and cascade systems. Flash gas removal and intercooling can further improve the performance of multi-stage systems. Cascade systems use multiple refrigerants matched to different temperature ranges.
The document provides information about thermodynamics and various types of power plants. It discusses key concepts in thermodynamics including systems, properties, laws of thermodynamics, and heat engines. It also describes different power plant technologies like thermal, hydroelectric, nuclear, solar, and wind power plants. Their basic working principles and components are explained along with the advantages and disadvantages of each type of power plant.
The document discusses refrigeration and air conditioning systems for automobiles. It is divided into 5 units and covers topics like refrigeration cycles, HVAC systems, and their applications. The objectives are to understand different refrigeration systems and apply the knowledge to design suitable air conditioning systems for vehicles. The assessment includes mid-exams, assignments, and an external exam. Students are expected to be able to apply concepts like refrigeration principles, HVAC design, and troubleshooting of air conditioners in automobiles.
Different types of expansion device used in refrigerator - tharmal II - 11601...Satish Patel
Different types of expansion devices used in refrigerators include hand operated valves, low-side floats, high-side floats, automatic expansion valves, thermostatic expansion valves, electronic expansion valves, capillary tubes, and solenoid valves. Automatic expansion valves automatically open when evaporator pressure drops and close when pressure rises to maintain a constant superheat. Thermostatic expansion valves similarly maintain a constant evaporator superheat using a temperature sensor. Capillary tubes provide a fixed restriction but do not control superheat.
The document discusses the properties of ideal refrigerants and absorbents for absorption refrigeration systems. An ideal refrigerant should boil between 2-10°C and condense above 40°C with a large latent heat of vaporization. An ideal absorbent should have a greater affinity for the refrigerant and release minimal heat during absorption with a high boiling point and chemical stability. Commonly used combinations are ammonia-water and lithium bromide-water which are described and compared in terms of their operating pressures and temperatures.
It is basic information about what is critical thickness and why we should we know this. Then there is critical thickness formula for cylindrical pipe and spherical shell.
The document discusses the simple vapor compression refrigeration system. It begins by defining what a vapor compression refrigeration system is and why they are needed over other refrigeration systems. It then outlines the basic mechanism and components of a simple vapor compression refrigeration cycle, including the compressor, condenser, expansion device, and evaporator. Finally, it discusses factors that affect the system's coefficient of performance and lists some advantages and disadvantages.
The document discusses different types of steam boilers. It describes steam generators/boilers as closed vessels that transfer heat from fuel combustion to water to generate steam. It then summarizes the key components and classifications of boilers, including fire tube vs water tube designs. Specific boiler types are then outlined in more detail, such as the Cochran, Lancashire and Cornish boilers, describing their designs, specifications and working principles.
1. A steam generator or boiler is a closed vessel made of steel that transfers heat from fuel combustion to water to generate steam.
2. Boilers should be safe, accessible for maintenance, efficient in absorbing heat, simple in construction, and have low initial and maintenance costs.
3. There are many types of boilers classified by factors like the contents in tubes (fire tube or water tube), furnace position, and circulation method. Proper consideration of factors like steam needs, area, and costs is important for boiler selection.
This document summarizes two types of brakes: simple band brakes and band and block brakes. For simple band brakes, it provides equations for calculating operating force based on parameters like tangential force, radius, and friction. Band and block brakes add wooden or other material blocks that further increase friction between the drum and brake. The document includes an example calculation for each brake type.
The document discusses centrifugal compressors. It begins with an introduction to air compressors in general, then describes the two main types: positive-displacement and dynamic-displacement. It focuses on centrifugal compressors, which use a rotating impeller to impart kinetic energy to air and compress it. The key components of a centrifugal compressor are the inlet, impeller, diffuser, and collector. Centrifugal compressors are commonly used in applications like gas turbines, turbochargers, pipelines, and HVAC due to benefits like fewer parts and higher efficiency compared to reciprocating compressors. However, they have a lower maximum compression ratio than reciprocating compressors.
This document discusses vapor compression refrigeration systems from Sana'a University in Yemen. It covers topics like coefficient of performance, the basic refrigeration cycle with four main components (evaporator, compressor, condenser, expansion valve), processes within the cycle, effects of evaporator and condenser temperatures, examples of cycle analysis, use of flash tanks and accumulators, and multistage compression systems. The document is presented by Dr. Abduljalil Al-Abidi from the Mechanical Engineering department and focuses on vapor compression refrigeration taught to students.
This document discusses refrigeration systems and their components. It describes the Carnot cycle and how it applies to refrigerators and heat pumps. The vapor compression cycle is explained in detail, including the functions of the compressor, condenser, expansion valve, and evaporator. Factors that affect system performance are outlined. Various refrigeration system configurations are presented, such as multipressure and cascade systems.
This document provides an overview of properties of pure substances and the steam power cycle. It begins by defining a pure substance and describing the three phases of matter: liquid, gas and vapor. It then explains the phase change process that water undergoes from compressed liquid to superheated vapor. Property diagrams like P-V, P-T, T-V and h-s diagrams are introduced to illustrate the thermodynamic properties. The ideal Rankine cycle and its processes are described along with methods to improve cycle efficiency like regeneration and reheat. Finally, it discusses other cycles like binary vapor cycles and combined cycles.
There are 5 main methods of supercharging internal combustion engines:
1) The compressor is driven directly by the engine using a belt or gears.
2) The compressor is driven by an exhaust gas turbine, with no direct mechanical connection to the engine. This is known as a turbocharger.
3) The compressor is driven by an external power source separate from the engine.
4) The engine drives both the compressor and a free turbine, with the turbine power used for an external load. This is known as a generator type supercharging.
5) The engine, compressor, and turbine are all directly coupled together using gears, with the turbine helping to drive the compressor under part load conditions on the engine
The document discusses the history and principles of vapor absorption refrigeration systems. Some key points:
- Vapor absorption was first discovered in 1824 by Michael Faraday and the first machine was built in 1860. It uses a refrigerant (ammonia) that is absorbed into a solvent (water) for compression.
- Unlike vapor compression, it uses heat rather than mechanical energy to change the refrigerant's state. This allows it to be powered by waste heat or solar energy.
- The first domestic refrigerator using this technology was invented in 1925 and used ammonia, hydrogen, and water in a "three-fluid" system to eliminate the need for a pump.
Refrigeration and air conditioning systems work by removing heat from an enclosed space to lower its temperature below the surrounding environment. There are two main types of refrigeration systems - vapor compression cycles and vapor absorption cycles. Vapor compression cycles use a compressor, condenser, expansion valve, and evaporator to remove heat. Vapor absorption cycles use heat to drive the refrigeration process rather than electricity. Air conditioning systems build on refrigeration principles to simultaneously control temperature, humidity, air motion, and quality within an enclosed space.
This document discusses multi-pressure refrigeration systems. It explains that single-stage systems have limitations at very low evaporator or high condenser temperatures due to increased losses. Multi-stage systems address this by using multiple compression stages to reduce the temperature lift in each stage. Types of multi-stage systems include multi-compression, multi-evaporator, and cascade systems. Flash gas removal and intercooling can further improve the performance of multi-stage systems. Cascade systems use multiple refrigerants matched to different temperature ranges.
The document provides information about thermodynamics and various types of power plants. It discusses key concepts in thermodynamics including systems, properties, laws of thermodynamics, and heat engines. It also describes different power plant technologies like thermal, hydroelectric, nuclear, solar, and wind power plants. Their basic working principles and components are explained along with the advantages and disadvantages of each type of power plant.
The document discusses refrigeration and air conditioning systems for automobiles. It is divided into 5 units and covers topics like refrigeration cycles, HVAC systems, and their applications. The objectives are to understand different refrigeration systems and apply the knowledge to design suitable air conditioning systems for vehicles. The assessment includes mid-exams, assignments, and an external exam. Students are expected to be able to apply concepts like refrigeration principles, HVAC design, and troubleshooting of air conditioners in automobiles.
Different types of expansion device used in refrigerator - tharmal II - 11601...Satish Patel
Different types of expansion devices used in refrigerators include hand operated valves, low-side floats, high-side floats, automatic expansion valves, thermostatic expansion valves, electronic expansion valves, capillary tubes, and solenoid valves. Automatic expansion valves automatically open when evaporator pressure drops and close when pressure rises to maintain a constant superheat. Thermostatic expansion valves similarly maintain a constant evaporator superheat using a temperature sensor. Capillary tubes provide a fixed restriction but do not control superheat.
The document discusses the properties of ideal refrigerants and absorbents for absorption refrigeration systems. An ideal refrigerant should boil between 2-10°C and condense above 40°C with a large latent heat of vaporization. An ideal absorbent should have a greater affinity for the refrigerant and release minimal heat during absorption with a high boiling point and chemical stability. Commonly used combinations are ammonia-water and lithium bromide-water which are described and compared in terms of their operating pressures and temperatures.
It is basic information about what is critical thickness and why we should we know this. Then there is critical thickness formula for cylindrical pipe and spherical shell.
The document discusses the simple vapor compression refrigeration system. It begins by defining what a vapor compression refrigeration system is and why they are needed over other refrigeration systems. It then outlines the basic mechanism and components of a simple vapor compression refrigeration cycle, including the compressor, condenser, expansion device, and evaporator. Finally, it discusses factors that affect the system's coefficient of performance and lists some advantages and disadvantages.
The document discusses different types of steam boilers. It describes steam generators/boilers as closed vessels that transfer heat from fuel combustion to water to generate steam. It then summarizes the key components and classifications of boilers, including fire tube vs water tube designs. Specific boiler types are then outlined in more detail, such as the Cochran, Lancashire and Cornish boilers, describing their designs, specifications and working principles.
1. A steam generator or boiler is a closed vessel made of steel that transfers heat from fuel combustion to water to generate steam.
2. Boilers should be safe, accessible for maintenance, efficient in absorbing heat, simple in construction, and have low initial and maintenance costs.
3. There are many types of boilers classified by factors like the contents in tubes (fire tube or water tube), furnace position, and circulation method. Proper consideration of factors like steam needs, area, and costs is important for boiler selection.
This document summarizes two types of brakes: simple band brakes and band and block brakes. For simple band brakes, it provides equations for calculating operating force based on parameters like tangential force, radius, and friction. Band and block brakes add wooden or other material blocks that further increase friction between the drum and brake. The document includes an example calculation for each brake type.
The document discusses centrifugal compressors. It begins with an introduction to air compressors in general, then describes the two main types: positive-displacement and dynamic-displacement. It focuses on centrifugal compressors, which use a rotating impeller to impart kinetic energy to air and compress it. The key components of a centrifugal compressor are the inlet, impeller, diffuser, and collector. Centrifugal compressors are commonly used in applications like gas turbines, turbochargers, pipelines, and HVAC due to benefits like fewer parts and higher efficiency compared to reciprocating compressors. However, they have a lower maximum compression ratio than reciprocating compressors.
This document discusses vapor compression refrigeration systems from Sana'a University in Yemen. It covers topics like coefficient of performance, the basic refrigeration cycle with four main components (evaporator, compressor, condenser, expansion valve), processes within the cycle, effects of evaporator and condenser temperatures, examples of cycle analysis, use of flash tanks and accumulators, and multistage compression systems. The document is presented by Dr. Abduljalil Al-Abidi from the Mechanical Engineering department and focuses on vapor compression refrigeration taught to students.
This document discusses refrigeration systems and their components. It describes the Carnot cycle and how it applies to refrigerators and heat pumps. The vapor compression cycle is explained in detail, including the functions of the compressor, condenser, expansion valve, and evaporator. Factors that affect system performance are outlined. Various refrigeration system configurations are presented, such as multipressure and cascade systems.
This document provides an overview of properties of pure substances and the steam power cycle. It begins by defining a pure substance and describing the three phases of matter: liquid, gas and vapor. It then explains the phase change process that water undergoes from compressed liquid to superheated vapor. Property diagrams like P-V, P-T, T-V and h-s diagrams are introduced to illustrate the thermodynamic properties. The ideal Rankine cycle and its processes are described along with methods to improve cycle efficiency like regeneration and reheat. Finally, it discusses other cycles like binary vapor cycles and combined cycles.
This document provides an overview of properties of pure substances and steam power cycles. It defines a pure substance as having a fixed chemical composition and discusses the three phases of matter. It describes the phase change process that water undergoes from compressed liquid to superheated vapor. Key concepts covered include saturation temperature and pressure, property diagrams, use of steam tables and Mollier charts, dryness fraction determination methods, and the ideal Rankine cycle. Variations of the Rankine cycle like reheat, regenerative, binary vapor, and combined cycles are also summarized.
Engineering Thermodynamics: Properties of Pure SubstancesMAYURDESAI42
Engineering thermodynamics is a branch of thermodynamics that deals with the practical application of thermodynamic principles and concepts. One of the fundamental topics in engineering thermodynamics is the properties of pure substances.
A pure substance is a material that has a fixed and constant chemical composition, regardless of its physical state. This means that a pure substance cannot be separated into two or more different substances by physical means. Examples of pure substances include water, oxygen, and carbon dioxide.
The properties of a pure substance are critical in thermodynamics because they are used to calculate important thermodynamic parameters, such as enthalpy, entropy, and internal energy. These parameters are used to understand the behavior of systems and predict their response to changes in temperature, pressure, and other conditions.
One of the key properties of a pure substance is its temperature-pressure phase diagram, which provides information about the physical state of the substance under different conditions. For example, water can exist as a solid (ice), a liquid (water), or a gas (steam) depending on the temperature and pressure conditions. This information is critical for understanding the behavior of a substance in different thermodynamic systems, such as power plants, refrigeration and air-conditioning systems, and chemical processes.
Another important property of a pure substance is its enthalpy of vaporization, which is the amount of energy required to convert a unit mass of the substance from a liquid to a gas at a constant temperature. This property is critical in many applications, such as the design of steam power plants, which use the energy stored in steam to generate electricity.
The specific heat capacity of a pure substance is another critical property. It represents the amount of energy required to raise the temperature of a unit mass of the substance by a unit temperature. This property is used to calculate the heat transfer in thermodynamic systems, such as refrigeration and air-conditioning systems.
Another important property of a pure substance is its thermal conductivity, which represents its ability to transfer heat. This property is critical in the design of heat exchangers, where heat is transferred from one fluid to another.
In conclusion, the properties of pure substances play a critical role in engineering thermodynamics. They provide valuable information about the behavior of a substance under different conditions and are used to calculate important thermodynamic parameters, such as enthalpy, entropy, and internal energy. This information is critical for the design and operation of a wide range of thermodynamic systems, such as power plants, refrigeration and air-conditioning systems, and chemical processes.
This document provides an overview of propulsion systems. It discusses different types of propulsion including liquid, solid, electric propulsion and others. It also covers key concepts in propulsion performance including specific impulse, thrust, nozzle design and equations. The document uses examples and diagrams to illustrate concepts in propulsion systems and their applications in launch vehicles and spacecraft.
Scotsman ice machine refrigeration training 101 - 0218.pptssuser0c24d5
This document provides an overview of refrigeration concepts and Scotsman equipment. It defines basic refrigeration terminology and components of a vapor compression system including the compressor, condenser, expansion device, evaporator and refrigerants. It explains the refrigeration cycle of freezing and harvesting ice. Key concepts are also summarized such as superheat, subcooling, pressure-temperature relationships and common units of measurement. The document outlines Scotsman ice making equipment and refrigeration systems for batch cubers and continuous flakers/nuggets. It introduces Scotsman refrigeration training courses that provide further details on equipment design and engineering processes.
Scotsman ice machine refrigeration training 101 - 0218.pptMaskiNano
This document provides an overview of refrigeration concepts and Scotsman equipment. It defines the basic refrigeration cycle and components including the compressor, condenser, expansion device, and evaporator. It explains key refrigeration terms like superheat and subcooling. It also outlines Scotsman ice maker models, their refrigeration systems, control sensors, freeze and harvest cycles, and engineering training courses. The document serves as an introduction to refrigeration systems and Scotsman equipment operations.
Scotsman ice machine refrigeration training 101 - 0218.pptJigneshChhatbar1
This document provides an overview of refrigeration concepts and Scotsman refrigeration systems. It defines common refrigeration terms and components of a basic vapor compression cycle. These include the compressor, condenser, thermal expansion valve, evaporator, and refrigerants. The document explains refrigeration units of measure and the refrigeration cycle processes of freezing and harvesting ice. It also covers refrigeration principles such as superheat, subcooling, and crankcase differential pressure. Finally, it introduces more advanced topics that will be covered in Scotsman Refrigeration 201, including different ice maker configurations and control systems.
This document discusses vapor compression refrigeration systems. It begins by defining air conditioning and refrigeration. It then lists common refrigerants used in vapor compression cycles along with their boiling points. The document outlines the ideal Carnot refrigeration cycle but notes limitations in practical applications. It describes the standard vapor compression refrigeration cycle used in practice. The document provides an analysis of vapor compression refrigeration systems and discusses concepts like throttling, superheating, subcooling, and cascade systems.
Project report on vcr system with liquid suction heat exchangerSant Lal Patel
vapour compression refrigeration system with liquid suction heat exchanger is benificial for engineering students .it is a final year project of mechanical engineering.
Simple vapour compression cycle and transcritical cycle are same but only Difference in Heat rejection Process.
In the transcritical cycle process, the heat rejection takes place at pressures and temperatures above the critical point – that is, in the fluid region.
A condition in the fluid region is often referred to as a gas condition.
For the transcritical cycle process, the heat rejection is therefore called gas cooling and subsequently the heat exchanger used is called a gas cooler.
This document defines key concepts in thermodynamics over 16 pages. It discusses systems and boundaries, open and closed systems, different types of processes like isothermal and adiabatic processes. It also defines properties of pure substances like saturated liquid and vapor. The first law of thermodynamics is explained as well as concepts like heat, work, internal energy. Devices like nozzles, diffusers, turbines and compressors are covered. The document also discusses entropy, the Carnot heat engine principle, and efficiency of compressors and turbines.
Presentation Outline:-
The Principles of Basic Refrigeration
Basic Refrigeration Cycle
There are countless applications for refrigeration plants now.
How do things get colder
Main Components
Accessories
Pressure
Pressure And Temperature
Refrigerator used for Cooling
Analysis of the Carnot Refrigerator
Terminology
The Vapor Compression Refrigeration Cycle
The Pressure-Enthalpy Diagram
Vapor Compression Refrigeration Analysis
VCR Cycle Irreversibilities
This document provides an overview of thermodynamics concepts including:
1. Thermodynamics is the study of energy, work, and heat transfer between systems and their surroundings.
2. Examples of thermodynamic systems include engines and refrigerators which involve heat transfer and work.
3. The two laws of thermodynamics establish the limits of energy transfer and conversion between thermal reservoirs.
Seven students presented a detailed approach on thermodynamics. They restated the first law of thermodynamics and defined enthalpy. Common enthalpy changes were discussed, including enthalpy of vaporization. The characteristics and physical model of enthalpy of vaporization were described. An experiment was conducted to determine the enthalpy of vaporization of water at different pressures using a Clausius-Clapeyron analysis of temperature and pressure readings. The results were within 5% of accepted values. Applications of enthalpy of vaporization include steam power generation and distillation.
This document discusses refrigeration and air conditioning systems. It covers topics like vapor compression systems, advanced vapor compression systems, vapor absorption systems, refrigerants and their properties, and applications of refrigeration systems.
Specifically, Unit 2 discusses vapor compression refrigeration systems in detail, including the basic vapor compression cycle, types of vapor compression cycles, theoretical cycles with dry/wet/superheated vapor, pressure-enthalpy diagrams, and examples calculating coefficient of performance. Unit 3 covers vapor absorption systems and different refrigerants used in refrigeration. The document also lists various refrigeration applications.
1. The document discusses actual and ideal thermodynamic cycles used in engines. It covers the Carnot, Otto, Diesel, and Dual cycles.
2. It then discusses fuel-air cycles which more accurately model the working fluid compared to ideal cycles. Fuel-air cycles account for variable specific heats, molecular effects, and dissociation losses.
3. The key differences between ideal, air standard, and actual engine cycles are analyzed. Actual cycles more accurately model processes and working fluids compared to ideal cycles but are more complex.
This document summarizes different techniques for solar cooling, including absorption cooling, desiccant cooling, and adsorption cooling. It provides details on the underlying physics and thermodynamic cycles involved. Absorption cooling uses lithium bromide or water/ammonia as working fluids. Adsorption cooling uses a solid adsorbent material to remove vapor from a gas in a reversible process, cycling between heating/pressurization and cooling/depressurization phases. While solar cooling technologies show potential, the document concludes they still require further technological development, performance data from real installations, and subsidies to improve market penetration and achieve significant energy savings compared to conventional cooling.
This document discusses energy analysis of steady-flow systems such as turbines, compressors, and nozzles. It provides the definitions and equations for steady-flow mass and energy balances in control volumes. Examples are also given to demonstrate how to use these equations to analyze steady-flow devices and calculate properties like mass flow rate and power. Key concepts covered include the steady-flow assumption of constant properties, the forms of the mass and energy balance equations, and examples of calculations for diffusers, compressors and turbines.
Similar to Performance Enhancement of a simple VCR Cycle (20)
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1. Hydroelectric power plants harness the potential energy of falling or fast-running water and convert it to electrical energy.
2. They require a water source, usually a dammed river or reservoir, to create water head and a hydroelectric turbine to convert the kinetic energy of flowing water into mechanical power to drive an electrical generator.
3. Hydroelectric power plants can be classified as high-head, medium-head, or low-head depending on the height of water fall, and as run-of-river, pondage, storage, or pumped storage depending on how water is stored and used.
This document provides details about a power plant engineering course, including course code, books, outcomes, and contents. The course aims to help students understand different power generation sources and apply concepts to measure performance. Key topics include thermal, hydroelectric, gas turbine, nuclear, solar, geothermal, wind, and tidal power plants, as well as electrical systems and economics.
This document discusses food preservation methods with a focus on refrigeration and cold storage. It defines food preservation as treating and handling food to slow or stop spoilage while maintaining nutrients. Refrigeration is used for food processing, preservation in cold storages, and distribution. Proper refrigeration temperatures are recommended for different foods. Cold storage facilities use vapor compression refrigeration cycles to circulate chilled air and cool produce. Domestic refrigerators and water coolers also use vapor compression cycles, circulating refrigerant through evaporator coils surrounding food compartments or water tanks to absorb heat and cool their contents.
This document provides an overview of air pollution. It defines pollution and describes different types including air, water, noise, soil, and radioactive pollution. Major sources of air pollution are described such as industries, vehicles, and the burning of fuels. Specific air pollutants like carbon monoxide, sulfur dioxide, nitrogen oxides, lead, and particulate matter are examined in terms of their sources and effects. Methods to control vehicle and industrial emissions like catalytic converters and regulations like emission standards in the US, Europe, and over time are summarized. The health and environmental impacts of air pollution are also reviewed.
This document discusses different types of condensation including filmwise condensation and dropwise condensation. Filmwise condensation occurs when a continuous film of condensate forms on a surface. Dropwise condensation occurs when droplets form instead of a continuous film, allowing for higher heat transfer rates. The document also provides equations to calculate heat transfer coefficients, mass flow rates, and film thickness for laminar condensation on vertical plates and horizontal tubes. Additionally, it describes how non-condensable gases can reduce heat transfer during condensation by forming a barrier between the vapor and condensing surface.
This document discusses different modes of boiling and pool boiling regimes. It explains that boiling occurs at the solid-liquid interface when the liquid is heated above its saturation temperature. There are different types of boiling including pool, flow, saturated, and subcooled boiling. Pool boiling occurs when the heated surface is submerged in stagnant liquid and features five distinct regimes: free convection, unstable nucleate, stable nucleate, unstable film, and stable film boiling, which are defined by the temperature excess above the liquid's saturation temperature. Flow boiling involves forced liquid motion from an external source in addition to natural convection.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
2. Introduction to VCRS
• As mentioned in the previous chapter, in a typical gas
cycle, the working fluid (a gas) does not undergo phase
change, consequently the operating cycle will be away
from the vapour dome.
• In gas cycles, heat rejection and refrigeration take place
as the gas undergoes sensible cooling and heating.
• In a vapour cycle the working fluid undergoes phase
change and refrigeration effect is due to the
vaporization of refrigerant liquid.
• If the refrigerant is a pure substance then its
temperature remains constant during the phase
change processes
Ankur Sachdeva, Assistant Professor, ME
3. Introduction to VCRS
• Vapour compression refrigeration systems are the most
commonly used among all refrigeration systems.
• As the name implies, these systems belong to the general
class of vapour cycles, wherein the working fluid
(refrigerant) undergoes phase change at least during one
process.
• In a vapour compression refrigeration system, refrigeration
is obtained as the refrigerant evaporates at low
temperatures.
• The input to the system is in the form of mechanical
energy required to run the compressor.
• Hence these systems are also called as mechanical
refrigeration systems.
Ankur Sachdeva, Assistant Professor, ME
5. Carnot Refrigeration Cycle on
T-s Diagram
Component Process
Compressor Isentropic
Compression (1-2)
Heat sink (Condenser) Heat Rejection at
Constant Temperature
(2-3)
Turbine Isentropic Expansion
(3-4)
Heat Source
(Evaporator)
Heat Extraction at
Constant Temperature
(2-3)
Ankur Sachdeva, Assistant Professor, ME
6. Components of a VCR System
Component Process
Compressor Isentropic
Compression (1-2)
Heat sink
(Condenser)
Heat Rejection at
Constant Pressure
(2-3)
Expansion Device Isenthalpic
Expansion (3-4)
Heat Source
(Evaporator)
Heat Extraction at
Constant Pressure
(4-1)
Ankur Sachdeva, Assistant Professor, ME
7. Low and High Pressure Sides
(VCR System)
Ankur Sachdeva, Assistant Professor, ME
8. Components of a Simple VCRS
Ankur Sachdeva, Assistant Professor, ME
13. Types of VCR cycle
Name of VCR
cycle
Condition at Inlet of
Compressor
Condition at Outlet of
Compressor
Wet Compression Wet (Dryness fraction , xr <1)
(L+V)
Wet (Dryness fraction , xr <1)
(L+V)
Wet Compression Wet (Dryness fraction , xr <1)
(L+V)
Dry, saturated Vapour
(Dryness fraction , xr =1)
Dry saturated Dry Saturated Vapour
(Dryness fraction , xr =1)
Superheated Vapour
(Dryness fraction , xr >1)
Superheated Superheated Vapour
(Dryness fraction , xr >1)
Superheated Vapour
(Dryness fraction , xr >1)
Ankur Sachdeva, Assistant Professor, ME
14. Wet VCR cycle
(Case-A: Refrigerant’s condition is “Wet” After Compression)
Point No. State of refrigerant
1 LT, LP, (Liquid + Vapour)
(x<1)
2 HT, HP,
(Liquid + Vapour) (x<1)
3 HT, HP, Saturated Liquid
(x=0)
4 LT, LP (Liquid +Vapour)
(x<1)
Ankur Sachdeva, Assistant Professor, ME
15. Wet VCR cycle
(Case-B: Refrigerant’s condition is “Dry & Saturated”
After Compression)
Point No. State of refrigerant
1 LT, LP, (Liquid + Vapour)
(x<1)
2 HT, HP,
(Saturated Vapour) (x=1)
3 HT, HP, Saturated Liquid
(x=0)
4 LT, LP (Liquid +Vapour)
(x<1)
Ankur Sachdeva, Assistant Professor, ME
16. Dry-Saturated VCR Cycle
(Refrigerant’s condition is “Superheated”
After Compression)
Point No. State of refrigerant
1 LT, LP, Dry & Saturated
Vapour (x=1)
2 HT, HP, Superheated Vapour
(x>1)
3 HT, HP, Saturated Liquid
(x=0)
4 LT, LP (Liquid +Vapour) (x<1)
Note: It is called dry saturated cycle because
refrigerant is in dry and saturated condition
at inlet to compressor
Ankur Sachdeva, Assistant Professor, ME
17. Superheated VCR Cycle
Point No. State of refrigerant
1 LT, LP, SH Vapour (x>1)
2 HT, HP, Superheated
Vapour (x>1)
3 HT, HP, Saturated Liquid
(x=0)
4 LT, LP (Liquid +Vapour)
(x<1)
Note: It is called superheated cycle because
refrigerant is in superheated condition at inlet
to compressor
Ankur Sachdeva, Assistant Professor, ME
18. Analysis of Simple VCRS
Ankur Sachdeva, Assistant Professor, ME
SFEE for a control volume
19. Analysis of Simple VCRS
• Compressor
– Neglecting the changes in K.E and P.E., Q = 0
• Work done by compressor (kW)
• Condenser
• Neglecting the changes in K.E and P.E., W = 0
– Heat Rejected in condenser
Ankur Sachdeva, Assistant Professor, ME
20. Analysis of Simple VCRS
• Expansion Device,
– Neglecting the changes in K.E and P.E., Q = 0, W =
0
• Evaporator
– Neglecting the changes in K.E and P.E., W = 0
– Heat Extracted by refrigerant in evaporator (kJ/s)
or refrigeration effect
Ankur Sachdeva, Assistant Professor, ME
21. Analysis of Simple VCRS
• Coefficient of Performance, 𝐶𝑂𝑃 =
𝑄𝑒
𝑊𝑐
Ankur Sachdeva, Assistant Professor, ME
22. Methods to improve Performance
of VCRS
(a) Sub-cooling of refrigerant leaving the
condenser
Ankur Sachdeva, Assistant Professor, ME
23. Methods to improve Performance
of VCRS
(b) Superheating of refrigerant entering the
compressor
Ankur Sachdeva, Assistant Professor, ME
26. Effect of Decrease in Evaporator
Pressure on VCR Cycle
Ankur Sachdeva, Assistant Professor, ME
27. Effect of Increase in Condenser
Pressure on VCR Cycle
Ankur Sachdeva, Assistant Professor, ME
As the condenser pressure decreases,
• Refrigerating effect decreases
• Compressor Work increases
• COP decreases