Introduction to Mechanical Engineering PDF

INTRODUCTION TO MECHANICAL ENGINEERING Subject Code: BESCK104D Prof. Dushyanthkumar G L Assistant Professor...

INTRODUCTION TO MECHANICAL ENGINEERING Subject Code: BESCK104D Prof. Dushyanthkumar G L Assistant Professor Dept. of Mechanical Engg. VVCE, Mysuru Prof. Dushyanthkumar, Dept. of M.E, VVCE  Textbooks and References Prof. Dushyanthkumar, Dept. of M.E, VVCE TEXTBOOKS- 1. A textbook of Elements of Mechanical Engineering by K. R. Gopalakrishna, Subhash Publishers, Bangalore, 2018. 2. Electric Vehicle Technology Explained by James Larminie and John Lowry, John Wiley & Sons Ltd, 2003. 3. An Introduction to Mechanical Engineering, Jonathan Wickert and Kemper Lewis, Third Edition, 2012. REFERENCE BOOKS- 1. Material Science and Engineering by R K Rajput, S K Kataria & Sons-New Delhi, 2013. 2. Workshop Technology, Volume I & II, - by S K Hajra Choudhury, A K Hajra Choudhury, Nirjhar Roy, 11th edition, Media Promotors and Publishers, Mumbai, 2001. 3. Automation, Production Systems and Computer Integrated Manufacturing by Mikell P Grover, Prentice hall of India Pvt. Ltd, 2002. 4. Modern Electric, Hybrid Electric and Fuel Cell Vehicles by Mehrdad Ehsani, Yimin Gao, Sebastien E. Gay and Li Emadi, CRC Press LLC, 2005. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Thermodynamics in engineering is the Thermodynamics has several types of All these work based on the study of energy and its various applications in our daily life. governing laws of interconversions from one form to thermodynamics. another. Fossil-fuelled steam power IC engines Jet engines Cars Motorcycles Trucks plants Air Ships Aeroplanes Refrigerators Etc. conditioners Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE Mechanical Engineering also involves study of various types of power plants. Thermal Nuclear Hydroelectric Solar power Wind power power plants power plants power plants plants plants Ocean Geothermal Biomass Tidal power Thermal power plants power plants plants power plants Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE CAN YOU SEE THE DIFFERNCE??? Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE  MECHANICAL ENGINEERING Mechanical Engineering is said to be the pioneer for all branches of engineering. It is also known as the evergreen Engineering branch. It primarily deals with mechanics, thermodynamics, robotics and aerospace. One of the oldest branch of engineering. Mechanical Engineering Emerged in 18th century during Industrial Revolution at Europe. Mechanical Engineering subject is the base or the foundation of the today’s society where every professionals need to study no matter whichever branch they belong to. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Objective and Connectivity Explain the principles, operations and processes of mechanical engineering. Develop Basics of Mechanical the ability to solve engineering problems. To Engineering (BME) familiarize the impact of mechanical engineering practices on environment Turbines, Hydro electric Power Plant Develops strong basics to study Thermal/Refrigeration & air conditioning higher semester. Pumps Manufacturing Industry, Lathes, Cutting tools & joining processes Prof. Dushyanthkumar, Dept. of M.E, VVCE  Module-1 Chapter – 1 Introduction to Energy and Its Conversion Prof. Dushyanthkumar, Dept. of M.E, VVCE MODULE 1: Introduction to Energy and its Conversion Introduction: Role of Mechanical Engineering in Industries and Society- Emerging Trends and Technologies in different sectors such as Energy, Manufacturing, Automotive, Aerospace, and Marine sectors. Energy: Introduction, types of energy sources like fossil fuels and bio-fuels. Environmental issues like global warming and ozone depletion. Power Plants: Basic working principles of hydel power plant, thermal power plant and nuclear power plant. Self-Study Component: Solar cells Prof. Dushyanthkumar, Dept. of M.E, VVCE  Role of Mechanical Engineering in Industries and Society A Mechanical engineer creates / designs and manufactures components / structures / machines / vehicles useful for mankind. An engineer is responsible for feasibly and optimally utilizing available sources of energy and converting it into useful product or process or services. Mechanical engineering plays a critical role in manufacturing from pins to rockets. Mechanical engineers work in various manufacturing industries, in building and designing various power plants, automobiles, railway equipment, spacecraft, etc. These mechanical engineers are sometimes called nuclear engineers, automotive engineers, railway engineers, aerospace engineers, etc. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Role of Mechanical Engineering in Industries and Society Mechanical Engineers play a vital role in the sustainable development of the industry and the society. Starting from the conceptualization of the product to the design, manufacturing, sales and service to the end of life of a product. Studying the design, laying out the tooling for the production and optimizing the raw material consumption in the manufacturing a component requires high skills. Mechanical Engineer also place a vital role in the logistics. Procuring the materials for the production, maintaining the adequate material in the stores, dispatching the finished products to the consumer is the role of a Logistic Engineer. Mechanical Engineer also works as a Safety Engineer in an Industry. Taking care of the human resources, machineries, equipment’s and planning out the safer working conditions and ensuring the safety of the operations is the responsibility of the safety engineer. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Role of Mechanical Engineering in Industries and Society Mechanical Engineer plays a vital role in the overall growth of the economy as well as the Society. Designing a product for longer product life cycle and reutilization/ recycling the product reduces the dependency of the materials by the industry. Also, developing newer equipment’s, devices for harnessing the renewable sources of energy reduces the dependencies on the fossil fuels. This in turn contribute to the green energy, low or no emission of carbon and its compounds. Following are few of the areas where in Mechanical Engineer play his role in an industry: Design Engineer, Production Manager, Safety Engineer, QA Engineer, Logistic Manager, Data analyst, Sales Executive/Manager, HRM, etc., Prof. Dushyanthkumar, Dept. of M.E, VVCE Emerging trends and technologies in different sectors Prof. Dushyanthkumar, Dept. of M.E, VVCE  Trends in Renewable Energy Renewable is one of the emerging trends in energy sector. This Renewable energy trend helps to safeguard the environment by emitting little to no harmful pollutants. The fundamental premise of renewable energy is to obtain it from a consistent source in the environment, such as the Sun, Wind, Tides, Or Geothermal sources. The source is then converted into useful power or fuel. A variety of technologies that address various facets of generating power and heat from renewable sources is one of the latest technology trends in renewable energy. This involves lowering the cost of building renewable infrastructure and enhancing the efficiency of power generation. Sources available in Sun, Wind, Tides, etc are utilized for useful power generation & other works. Prof. Dushyanthkumar, Dept. of M.E, VVCE  RENEWABLE ENERGY SOURCES Prof. Dushyanthkumar, Dept. of M.E, VVCE  Aerospace Sector Aerospace collectively refers to the atmosphere and outer space; it's a diverse industry with a multitude of commercial, industrial, and military applications. Aerospace engineering consists of aeronautics (Building and flying aircrafts) and astronautics (Space travel and exploration) and the research, design, production, operation, or maintenance of aircraft and spacecraft. The trending sectors in Aerospace engineering technology are; 1. Zero-Fuel Aircraft 2. Structural Health Monitoring (SHM) 3. Advanced Materials 4. Additive Manufacturing (3D Printing) 5. Supersonic Flights 6. More Resilient and Dynamic Aerospace & Defence (A&D) Supply Chains 7. Artificial intelligence (Al) 8. Autonomous Flight Systems Prof. Dushyanthkumar, Dept. of M.E, VVCE  YouTube Link https://youtu.be/5Fi65k2K3Mw VVCE Prof. Dushyanthkumar, Dept. of M.E, Automotive Sector Electric and Autonomous vehicles are the two important areas witnessed nowadays. The automotive industry has been experiencing a great deal of change. Software is being added to vehicles, along with a greater number of electric and autonomous vehicles. These are in production and on the road. Some of the most common automotive trends are; A Greater Amount of Al/Machine Learning and Connectivity An increase ln Electric and Autonomous Vehicles Software Security Has Become a Top Concern Electrification Human-Machine-interface Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE  Manufacturing Sector YouTube Link https://youtu.be/EiLVzOLMj9g Robotics and 3-D printing are the domains which are in demand. Al, robots, 3D printing are all the latest trends in manufacturing technology. Robots on the factory floor are growing at warp speed, thanks to their declining cost and increasing capabilities Prof. Dushyanthkumar, Dept. of M.E, VVCE  Energy Storage Energy systems offer diverse set of technological solutions for improving power supply methods like batteries, thermal, mechanical and hydrogen energy. Energy storage permits steady pricing by proactively maintaining demand from consumers. ln response to shifting energy demands and technological advancements, the energy storage business has evolved, adapted, and innovated during the last century. Energy storage systems offer a diverse set of technological solutions for improving the power supply to build more resilient energy infrastructure and save money for utilities and customers. Energy storage methods can be classified into five categories based on their technology; Batteries Thermal Mechanical Pumped hydro Hydrogen It has the potential to save consumers money while also improving dependability and resilience, integrating power sources, and reducing environmental impacts. Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE  Marine sector Advances in ship building, propulsion, smart shipping, advanced materials, big data and analytics, robotics, sensors and communications are the areas in Marine sector which demands more focus currently. In conjunction with an increasingly skilled workforce, having monumental shifts in how the maritime industry is approaching new challenges and opportunities. Prof. Dushyanthkumar, Dept. of M.E, VVCE MODULE 1: Introduction to Energy and its Conversion Introduction: Role of Mechanical Engineering in Industries and Society- Emerging Trends and Technologies in different sectors such as Energy, Manufacturing, Automotive, Aerospace, and Marine sectors. Energy: Introduction, types of energy sources like fossil fuels and bio-fuels. Environmental issues like global warming and ozone depletion. Power Plants: Basic working principles of hydel power plant, thermal power plant and nuclear power plant. Self-Study Component: Solar cells Prof. Dushyanthkumar, Dept. of M.E, VVCE INTRODUCTION Most of the energy that we use is mainly derived from conventional/ non-renewable energy sources. Due to the vast demand of energy, the rate of depletion of these resources have reached alarmingly low levels. This situation has directed us to seek alternate energy sources such as solar, wind, ocean, biomass, Hydel etc. Prof. Dushyanthkumar, Dept. of M.E, VVCE  ENERGY AND POWER ENERGY Energy is the capacity to do work in various forms. Energy is a property that must be transferred to an object in order to perform work on, or to heat, the object. It can be converted from one form to another but cannot be created or destroyed. The SI unit of energy is joule, which is the energy transferred to an object by the work of moving it a distance of 1 meter against a force of 1 newton Prof. Dushyanthkumar, Dept. of M.E, VVCE  Energy and power are related but totally different concepts. A tank of petrol contains a certain amount of energy. We can combust this petrol in a certain time period, that is, we convert the energy of the petrol into mechanical energy, perhaps to power a car. The power is Prof. Dushyanthkumar, Dept. of M.E, the energy produced per unit of time. VVCE CHARACTERISTICS OF GOOD SOURCE OF ENERGY A source of energy is one which can provide adequate amount of energy in a convenient form over a long period of time. Large amount of work per unit mass Cheap and easily available Easy to store and transport Safe to handle and use No pollution Prof. Dushyanthkumar, Dept. of M.E, VVCE NON RENEWABLE SOURCE OF ENERGY It is a source of energy which cannot be renewed. E.g.: Coal, fossil fuels like petroleum and natural gas, Nuclear fuels-uranium Exhaustible source of energy RENEWABLE SOURCE OF ENERGY E.g.: Wood, wind energy, hydro energy, solar energy Inexhaustible source of energy Prof. Dushyanthkumar, Dept. of M.E, VVCE  Non-Renewable Energy Factor Renewable Energy Sources Sources Exhaustibility/ Inexhaustibility Inexhaustible Exhaustible Availability Abundantly and freely available Not abundantly available Replenishment Replenished Naturally Cannot be replenished Environment friendly except in Environmental Friendliness Not environment friendly case of biomass Building Systems cost is high, Cost Factor Production cost is high running cost is low Nature of Availability Intermittently available Continuously available Regional restriction and No regional restriction Available in certain countries dependency factor Prof. Dushyanthkumar, Dept. of M.E, VVCE Types of Fossil Fuels: 1) Solid fuels (Coal) 2) Liquid fuels (Crude oil) 3) Gaseous fuels (Natural Gas)  Solid fuels Coal is the major fuel used for thermal power plants. Coal occurs in nature, which was formed by the decay of vegetable matters buried under the earth millions of years ago under pressure and heat. This phenomenon of transformation of vegetable matter into coal under earth’s crust is known as Metamorphism. The major constituents in coal is moisture (5-40%), volatile matter (combustible & or incombustible substances about 50%) and ash (20-50%). The chemical substances in the coal are carbon, hydrogen, nitrogen, oxygen and sulphur. Prof. Dushyanthkumar, Dept. of M.E, VVCE Liquid Fuels All types of liquid fuels used are derived from crude petroleum and its by- products. The petroleum or crude oil consists of 80-85% Carbon, 10-15% hydrogen, and varying percentages of sulphur, nitrogen, oxygen and compounds of vanadium. The crude oil is refined by fractional distillation process to obtain fuel oils, for industrial as well as for domestic purposes. The fractions from light oil to heavy oil are naphtha, gasoline, kerosene, diesel and finally heavy fuel oil. The heavy fuel oil is used for generation of steam in power plants.  Gaseous Fuels For generation of steam in gas fired thermal plants, either natural gas or manufactured gaseous fuels (artificial gas) are used. However, manufactured gases are costlier than the natural gas. Generally, natural gas is used for power plants as it is available in abundance. The natural gas is generally obtained from gas wells and petroleum wells. The major constituent in natural gas is methane, about 60-65%, and also contains small amounts of other hydrocarbons such as ethane, naphthene and aromatics, carbon dioxide and nitrogen. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Natural gas is transported from the source to the place of use through pipes, for distances upto several hundred kilometers. The natural gas is colourless, odourless and non-toxic. Its calorific value ranges from 25,000 to 50,000 kJ/m3, in accordance with the percentage of methane in the gas. The artificial gases are producer gas, coke oven gas; and the Blast furnace gas. The gaseous fuels have advantages similar to those of liquid fuels, except for the storage problems. The major disadvantage of power plant using natural gas is that it should be setup near the source; otherwise the transportation losses are too high. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Calorific values of fuels: ✓The calorific value is the measurement of heat or energy produced and is measured either as gross calorific value or net calorific value. ✓Calorific value of fuel is the amount of heat liberated during complete combustion of unit quantity of the fuel. ✓ The Calorific value of solid and liquid fuel is the amount of heat liberated during complete combustion of unit mass of fuel. It is expressed in kJ/kg ✓The Calorific value of gaseous fuel is the amount of heat liberated during complete combustion of unit volume of fuel. It is expressed in kJ/ m3 Prof. Dushyanthkumar, Dept. of M.E, VVCE RENEWABLE ENERGY SOURCES Prof. Dushyanthkumar, Dept. of M.E, VVCE  Biomass is any material made by plants and animals that can be converted into energy. Biological renewable energy source from living or dead organisms. Animals feed on plants, and plants grow through the photosynthesis process using solar energy. Thus, photosynthesis process is primarily responsible for generation of biomass energy. CO2 + H2O -------( Light) ------→ CH2O +O2 (Carbohydrate) 6CO2 + 12H2O -------( Light) ------→ C6H12O6 + 6H2O + 6O2.(Sugar) Biomass is organic matter produced by plants, both terrestrial and aquatic. Biomass Energy is stored in the form of complex organic compounds of carbon, hydrogen, oxygen, nitrogen, etc. Biomass is organic carbon-based material that reacts with oxygen in combustion and natural metabolic processes, to release heat. The biomass can be converted to useful energy forms such as – Heat, Gaseous fuel, Solid fuel, Organic chemical, Liquid fuels (Bio-fuels) Prof. Dushyanthkumar, Dept. of M.E, VVCE Biomass sources Forestry Crops & Residues Agricultural Crops & Residues Sewage waste Industrial Residues Animal Residues Municipal solid waste Prof. Dushyanthkumar, Dept. of M.E, VVCE  Biomass conversion Technologies 1. Incineration: It is direct combustion of biomass for immediate useful heat. The heat produced are used to generate electricity, cooking, space heating or Industrial processing. Ex. Waste wood, saw waste, cow dung, etc. 2. Thermo-chemical: The thermo-chemical process to convert biomass into more valuable or convenient product is known as pyrolysis. Biomass is heated either in absence of oxygen or partial supply of oxygen to produce producer gas, liquid oil and carbon char. 3. Bio-chemical: The process make use of metabolic action of microbial organism on biomass to produce liquid and gaseous fuels. This process take place in the absence of oxygen known as anaerobic fermentation. Decaying wet biomass Anaerobic Prof. Dushyanthkumar, Dept. of M.E, fermentation VVCE Bio-gas production from organic waste Prof. Dushyanthkumar, Dept. of M.E, VVCE  Bio-fuels The term ‘Bio-fuel’ refers to liquid or gaseous fuels that are predominantly produced from biomass like plants and crops. A variety of fuels can be produced from biomass resources including liquid fuels, such as ethanol, methanol, biodiesel and gaseous fuels such as hydrogen and methane. The biomass resource base for bio-fuel production is composed of a wide variety of forestry and agricultural resources, industrial processing residues, and municipal solid and urban wood residues. A variety of regionally significant crops, such as cotton, sugarcane, rice, and fruit can also be a source of crop residues. The forest resources include residues produced during the harvesting of forest products, fuel wood extracted from forestlands. Residues generated at primary forest product processing mills, and forest resources that could become available through initiatives to reduce fire hazards and improve forest health. Prof. Dushyanthkumar, Dept. of M.E, VVCE  Biodiesel: Extraction with or without esterification of vegetable oils from seeds of plants like soybean, oil palm, oilseed, rapseed and sunflower or residues including animal fats derived from rendering applied as fuel in diesel engines Bio-ethanol: Fermentation of simple sugars from sugar crops like sugarcane or from starch crops like maize and wheat applied as fuel in petrol engines. Bio-oil: Thermo-chemical conversion of biomass. A process still in the development phase. Biogas: Anaerobic fermentation or organic waste, animal manures, crop residues an energy crops applied as fuel in engines suitable for compressed natural gas. Prof. Dushyanthkumar, Dept. of M.E, VVCE Applications of Biofuels Problems Associated Biogas is cheap and sustainable fuel Some types of biodiesel have exhibited used in lighting, cooking or storage instability that could lead to generating electricity. engine problems. Biodiesel finds use in automotive Sometimes, vegetable oils create adverse industry mainly in cars and trucks. effects on engine components which may be due to their different volatility and Small engines, of the kind seen in molecular structure from diesel fuel as lawn mowers and chainsaw. well as high viscosity compared with The marine industry finds diesel fuel. application of biodiesel in suitable blend mixtures to be used in boats Currently, this problem is being eliminated and ships. by applying different chemical processes such as trans-esterification, catalyst-free process etc., on vegetable oils to convert Prof. Dushyanthkumar, Dept. of M.E, into biodiesel. VVCE Comparison of bio-fuels with Petroleum Biofuels Petroleum fuels Do not release as much carbon as Petroleum fuels gives off toxic 1 petroleum fuels and are less toxic emissions and green house gases. 2 Renewable source of energy Non-renewable source of energy Biodegradable as they are made out Not biodegradable and affect 3 of organic substances environment badly. Low calorific value, vary from 30 to Higher calorific value vary between 43 4 38 MJ/kg. to 48MJ/kg For instance, to find oil reserves, 5 It is safer to produce biofuels dangerous drilling and mining activities prove to be unsafe. 6 Efficiency is less Prof. Dushyanthkumar, Dept. of M.E, VVCE Efficiency is more  Global warming (Climate Change) refers to the rise in Global Warming average surface temperature on earth. The primary cause for global warming is burning of Global warming is a gradual increase in fossil fuels, which emits green house gases. the overall temperature of the earth's atmosphere generally attributed to the Green house gases are also caused by Animals, greenhouse effect caused by increased Livestock, Fertilizers, etc. levels of carbon dioxide, cfcs, and other Effects of Global Warming: pollutants. Climate change Remedial Measures: Rise in sea level Reduce the use of fossil fuels by Decreased food production adopting clean energy Higher temperatures/ Heat waves Reduce nitrogen fertilizers Heavier storms Prevent deforestation by growing plants Shrinking sea ice/ Shrinking glaciers Recycle extensively Shifting species Prof. Dushyanthkumar, Dept. of M.E, VVCE Causes of Global Warming Greenhouse Effect Carbon dioxide emissions from fossil Greenhouse effect is the process by fuel burning power plants which radiation from a planet's atmosphere warms the planet's Carbon dioxide emissions from surface to a temperature above burning gasoline for transportation what it would be. Methane emissions from animals, Earth’s natural greenhouse effect is agriculture such as rice paddies, and critical to supporting life. from arctic seabed's Human activities, mainly the burning Deforestation, especially tropical of fossil fuels and clearing of forests for wood, pulp, and farmland forests, have strengthened the Increase in usage of chemical greenhouse effect and caused fertilizers on croplands global warming. Prof. Dushyanthkumar, Dept. of M.E, VVCE How can you stop global warming “Change only happens when individuals take action and there’s no other way, if it doesn’t start with people” 1. Awareness 2. Power your home with solar energy 3. Weatherize, weatherize, weatherize. 4. Invest in energy-efficient appliances. 5. Reduce water waste. 6. Eat the food you buy 7. Buy better bulbs. 8. Drive a fuel-efficient vehicle. Etc.. Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE  Ozone (O3) layer A layer in the earth's stratosphere at an altitude of about 20 km (12 miles) containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun. The production of ozone in the stratosphere results primarily from the breaking of the chemical bonds within oxygen molecules (O2) by high- energy solar photons. This process, called photodissociation, results in the release of single oxygen atoms, which Prof. Dushyanthkumar, later join with intact oxygen molecules to form ozone. Dept. of M.E, VVCE  Ozone (O3) is a natural, colorless gas that is present in our atmosphere. It is found in two regions, namely Troposphere (10%) and Stratosphere (90%) This layer blocks the suns harmful ultraviolet rays from reaching the earth’s surface. Ozone The layer is destroyed by ODS, like chlorofluorocarbons (CFC’s), halons, methyl chloroform, carbon tetrachloride, methyl bromide, etc. depletion These substances are found in Refrigerators, AC’s, fire extinguishers, agricultural fumigants, aerosols, etc. Depletion of ozone layer results in; ▪ Skin cancer and cataracts ▪ Genetic disorder in living organisms Prof. Dushyanthkumar, Dept. of M.E, ▪ Reduced reproduction rates in young fish, shrimp, crabs, frogs, etc. VVCE  Causes For Ozone Effects of ozone Layer Depletion layer depletion Chlorofluorocarbons (CFCs) Skin cancer Hydro-chloro-fluoro-carbons (HCFCs) Effects on aquatic ecosystems Halons Effects on terrestrial ecosystems Methyl bromide (CH3Br) Animals Plants Carbon tetra-chloride (CCl4) Prof. Dushyanthkumar, Dept. of M.E, VVCE  How to avoid Ozone depletion Buy air-conditioning and refrigeration equipment that do not use CFCs as refrigerant. (The interim replacement for CFC are HCFC) Buy aerosol products that do not use CFCs as propellants. Conduct regular inspection and maintenance of air-conditioning and refrigeration appliances to prevent and minimize refrigerant leakage. Use of Natural refrigerants. HFCs with lower GWP (Global Warming Potential), such as R32. Hydrofluoroolefins (HFOs) and HFC-HFO blends. Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE MODULE 1: Introduction to Energy and its Conversion Introduction: Role of Mechanical Engineering in Industries and Society- Emerging Trends and Technologies in different sectors such as Energy, Manufacturing, Automotive, Aerospace, and Marine sectors. Energy: Introduction, types of energy sources like fossil fuels and bio-fuels. Environmental issues like global warming and ozone depletion. Power Plants: Basic working principles of hydel power plant, thermal power plant and nuclear power plant. Self-Study Component: Solar cells Prof. Dushyanthkumar, Dept. of M.E, VVCE Power Plants A power plant may be defined as a machine or assembly of equipment that generates and delivers a flow of mechanical or electrical energy. The main equipment for the generation of electric power is generator, when coupling it to a prime mover runs the generator, the electricity is generated. Different types of Conventional Power Plants are; Thermal Power Plant (Steam Power Plant, Diesel Power Plant, Gas Turbine Power Plant and Nuclear Power Plants) – Convert heat into electrical energy. Hydroelectric Power Plant – Hydraulic energy into electrical energy. The Non-conventional Power Plants are Solar system, Wind energy power system, Geothermal energy, OTEC, Wave and Tidal Energy, Biogas and Biomass energy power system. Prof. Dushyanthkumar, Dept. of M.E, VVCE  “Aprime mover is a self moving device which converts the available natural source of energy into mechanical energy of motion to drive other machines.” "Prime mover is device, which use the energy from natural sources and converts it into mechanical energy”. Introduction to Sources of energy used by prime movers – Fossil fuels, River water, Prime movers Nuclear, Wind, Solar, etc. Types of Prime Movers: 1. Thermal Prime Movers – Heat engines, Steam Turbines, Gas Turbines, Nuclear power plant, Geothermal, Bio-gas, Solar energy, etc. 2. Non-Thermal Prime Movers – Hydraulic Turbines, Wind Power (Wind turbine), Tidal power. Prof. Dushyanthkumar, Dept. of M.E, VVCE Hydel Power Plant Prof. Dushyanthkumar, Dept. of M.E, VVCE  Hydro Electric Power Station Prof. Dushyanthkumar, Dept. of M.E, VVCE Reservoir: This is used to store large amount of water during rainy season & supply water during other seasons. Water is not only used for power generation, but also for flood control, irrigation, water supply, navigation, etc. Dam: Dam is a structure of considerable height built across the reservoir. Trash rack: It is provided for preventing the entry of debris (dirt, dust) from dam, because any debris into the intake water pipe may damage the turbine blades or choke up the flow. It is generally made of steel. Gate: It is provided to control the flow of water from reservoir to the turbine. According to the requirement, Prof. Dushyanthkumar, Dept. of M.E, gate opening can be changed. VVCE Penstock: It is a pipeline which carries water from reservoir to the turbine. Generally, to withstand high pressures, it is made of concrete and of 1m to 2m in diameter. Control room: Control room or power-house consists of turbine, generator and other electric equipment to convert mechanical energy of turbine into electrical energy Turbine: Turbine is used to convert kinetic energy of water into mechanical energy. Generally used hydraulic turbines are Pelton wheel turbine, Kaplan turbine & Francis turbine. Tail race: It is a path to lead the water discharged from the turbine to the river. Prof. Dushyanthkumar, Dept. of M.E, VVCE WORKING PRINCIPLE The water flowing in the river possesses two type of energy: (1) Kinetic energy due to flow of water and (2) Potential energy due to the height of water. During operation, the water is supplied to the turbine through the penstock, which is located at much lower level than the height of water reservoir. Then the water is impinged on the turbine blades which drives the turbine shaft to generator power. The total power generation capacity of the hydroelectric power plant depends on the head of water and volume of water flowing towards the water turbine The hydroelectric power plant hydro power plant, is used for generation of electricity from water on large scale basis. The dam is built across the large river that has enough water throughout the river. In certain cases where the river is very large, more than one dam can build across the river at different locations. Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE Advantages: Disadvantages: Water source is easily and readily Power generation is dependent on the available. quantity of water available, which may No fuel is to be burnt to generate the vary from season to season. power. These power plants are located far The running cost of these power plants from the load center which requires is very low as compared to thermal long transmission lines. power plants. The cost of transmission lines & losses These power plants are more reliable. are more. There is no disposal problem of ash, The time required for set up of plant is emission of polluting gases and more. particulates. Initial cost of set up is very high. Life expectancy of these power plants is higher. Prof. Dushyanthkumar, Dept. of M.E, VVCE Nuclear Power Plant Prof. Dushyanthkumar, Dept. of M.E, VVCE Nuclear Power Plant Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE A generating station in which nuclear energy is converted into electrical energy is known as nuclear power station. The commonly used nuclear fuels are unsteady atoms like uranium(U235), thorium (Th232) and plutonium(Pu239) The main components of this station are nuclear reactor, heat exchanger or steam generator, steam or gas turbine, ac generator and condenser. The reactor of a nuclear power plant is like the furnace in a steam power plant. The heat liberated in the reactor due to the nuclear fission of the fuel is taken up by the coolant circulating in the reactor. A hot coolant leaves the reactor at top and then flows through the tubes of heat exchanger and transfers its heat to the feed water on its way. The steam produced in the heat exchanger is passed through the turbine and after the work has done by the expansion of steam in the turbine, steam leaves the turbine and flows to the condenser. Pumps are provided to maintain the flow of coolant, condensate, and feed water The mechanical or rotating energy developed by the turbine is transferred to the generator which in turn generates the electrical energy. Prof. Dushyanthkumar, Dept. of M.E, VVCE Advantages: Disadvantages: Nuclear power plant does not Initial cost of plant set up is high. require fossil fuels like coal, coke, natural gas which can be used in Nuclear fuels are not available other areas. easily. Less space required as compared to steam power plants. There is problem of disposal of radioactive waste. Large amount of energy is generated by burning small amount of fuel. Prof. Dushyanthkumar, Dept. of M.E, VVCE Steam Power Plant Prof. Dushyanthkumar, Dept. of M.E, VVCE Steam Power Plant Prof. Dushyanthkumar, Dept. of M.E, VVCE  The basic components (and their function) of a steam power plant are : 1. Steam boiler : In the boiler, the fuel (coal or oil) is burnt in presence of air. The heat energy released due to combustion of fuel is utilized for conversion of feed water into steam. 2. Steam turbine : The steam generated in the boiler is supplied to steam turbine where it expands adiabatically upto the condenser pressure or exhaust pressure. It produces mechanical work, which is further converted into electrical energy by the generator. 3. Condenser : The exhaust steam from steam turbine is passed through a heat transfer device called condenser. The steam is condensed in the condenser by rejecting heat to cooling water circulated in the condenser. Condensed steam is called condensate. 4. Feed pump : The feed pump increases the pressure of condensate upto boiler pressure on the expense of work done on the pump. Thus a thermodynamic cycle is completed. Prof. Dushyanthkumar, Dept. of M.E, VVCE  A steam power plant is a thermal power station where the heat energy of the fuel is converted into electricity. The fuel used can be coal, oil, gas, etc. In a steam power plant, the boiler utilizes the heat of fossil fuel combustion to raise steam at high pressure and temperature. The generated steam is used to drive a steam turbine and produce electricity. A steam power plant consists of a boiler, steam turbine and generator, and other auxiliaries. The boiler generates steam at high pressure and high temperature. Rankine cycle The steam turbine converts the heat energy of steam into mechanical energy. The generator then converts the mechanical energy into electric power. Rankine cycles describe the operation of steam heat engines. In such vapor power plants, power is generated by alternately vaporizing and condensing a working fluid Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE  Advantages of steam power plant Disadvantages of steam power plant 1. Requirement of space for the erection of power plant is the 1.The maintenance and operating cost of the steam lesser compared to hydroelectric power plant. power plant is high. 2. Comparing with other plants steam power plant requires less 2.Pollution caused due to a steam power plant is high initial cost for the same capacity. due to fumes and residues from pulverized fuel. 3. Steam power plants can be installed anywhere despite the availability of fuel. However, in the case of the hydroelectric 3.The requirement of water to convert the heat into power plant, it should be installed near the water source. steam is very high. 4. Such plants can be located near the load center, and the 4.Disposal of ash and handling of coal is difficult. required transmission cost of electricity will be low. Still, in 5.The steam power plant produces a huge amount of the case of a hydroelectric power plant where water is heat and smoke, which sometimes causes trouble to available, these plants are installed only despite the load center. the neighbouring environment. 5. Can respond to the rapid change in load conditions without 6.The plant cost increases with an increase in operating any difficulty. temperature. 6. The overload capacity of the steam power plant is higher 7.Costly in operating cost in comparison with a hydro than other plants. Steam turbines and steam engines can and nuclear power plant. work under overload continuously. 7. Some portion of steam raised can also be used in textile mills,Prof. paper mills, refineries, chemical work, etc. Dushyanthkumar, Dept. of M.E, VVCE  Self Study Topic- Solar Cells Prof. Dushyanthkumar, Dept. of M.E, VVCE SOLAR CELL / PHOTOVOLTAIC CELL Solar energy can be directly converted to electrical energy by means of photovoltaic effect. Photovoltaic effect is defined as the generation of an electromotive force (EMF) as a result of the absorption of ionizing radiation. Devices which convert sunlight to electricity are known as solar cells or photovoltaic cells. Solar cells are based on semi-conductor technology. Solar cell consists of combination of p-type and n-type semiconductors. N- type semiconductor has excess number of electrons , where as p-type semiconductor has deficiency of electrons. Prof. Dushyanthkumar, Dept. of M.E, VVCE  N-Type semiconductor: It is created by adding pentavalent impurities like phosphorus (P), arsenic (As), antimony (Sb), or bismuth (Bi). A pentavalent impurity is called a donor atom because it is ready to give a free electron to a semiconductor P-Type Semiconductor: The addition of trivalent impurities such as boron, aluminium or gallium to an intrinsic semiconductor creates deficiencies of valence electrons called "holes". Such a piece of semiconductor with one side of the p-type and the other of the n-type is called a p-n junction. In this junction after the photons are absorbed , the free electrons of the n- side will tend to flow to the p-side , and the holes of p-side will tend to flow to the n region to compensate for their respective deficiencies. Prof. Dushyanthkumar, Dept. of M.E, VVCE  P-V Cell construction Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE Advantages Disadvantages: High cost. No need to work at higher temperature Energy storage required as the solar No moving parts energy is unavailable at night. Solar energy conversion is without pollution Applications: Higher power handling capacity. Street lighting & railway signaling. Rapid response to changes in input Electrical power generation in space craft. radiation. In small or large power plants. No requirement of fuel as solar energy is free. Automatic weather monitoring. They have high power to weight ratio. Used to operate irrigation pump & drinking water supply. Long life. Prof. Dushyanthkumar, Dept. of M.E, VVCE Prof. Dushyanthkumar, Dept. of M.E, VVCE Additional Information- Beyond the Syllabus Prof. Dushyanthkumar, Dept. of M.E, VVCE Steam Turbine Prof. Dushyanthkumar, Dept. of M.E, VVCE  Fire Tube Boiler Water Tube Boiler Prof. Dushyanthkumar, Dept. of M.E, VVCE  Impulse Turbine Pelton Wheel Prof. Dushyanthkumar, Dept. of M.E, VVCE  Francis Turbine Kaplan Turbine Prof. Dushyanthkumar, Dept. of M.E, VVCE Sharavathi Penstocks Prof. Dushyanthkumar, Dept. of M.E, VVCE  Varahi Generator station Prof. Dushyanthkumar, Dept. of M.E, VVCE