Energy Saving and Conversion(MSJ0200)

2011. Autumn semester

1.and 2. lectures

Introduction

Course content (1)

• Energy classification• Sources and utilization • Energy Conversion• Buildings– Thermal energy conversion in buildings, low energy and passive

houses, eco materials. – Different heating systems, appliance of heating and ventilations

systems, district heating and local heating. – Electrical management of buildings. Heating and ventilation

control systems.

Course content (2)

• Industry– Thermal energy management of industry, utilization of waste

heat. – Process energy efficiency (logistics, electrical power

management).

• Transportation– Energy consumption of transportation.– Emissions from transportations, directives, regulations.

• Different type of internal combustion engines, hybrid and hydrogen cars.

Course content (3)• Power Plants. – Fuels for generating power (fossil, nuclear, renewable). – Steam power plants. – Gas turbines power plants. – Hydraulic power plants. – Advance fossil fuel power plants. – Combined-cycle power plant. – Solar power plant.

• Wind energy conversion. Waste to energy conversion. Biomass conversion process for energy recovery. Nuclear power technologies

Course plan (1)29.08: 1, 2 lectures: •Description of the course•Introduction, history of energy conversion•Energy classification, sources30.08: 3, 4 lectures:•Transportation. Energy consumption of transportation. •Emissions from transportations, directives, regulations. •Different type of internal combustion engines, hybrid and hydrogen cars

Course plan (2)

31.08: 5, 6 lectures:- Energy conversion. Buildings. Thermal energy conversion in buildings, low energy and passive houses. - Different heating systems, district heating and local heating. 01.09: 7, 8 lectures:• Nuclear power technologies

Course plan (3)

02.09: 9, 10 lectures:• Fuels for generating power (fossil, nuclear,

renewable). •Shale gas•Steam power plants.

05.09: 11, 12 lectures:•Combined-Cycle Power Plants•Advance fossil fuel power plants.

Course plan (4)06.09: 13, 14 lectures:• Wind energy• Solar power plants

07.09: 15, 16 lectures:•CHP using gas fired Internal combustion engine•Stirling engine•Industry– Thermal energy management of industry,

utilization of waste heat. – Process energy efficiency (logistics, electrical

power management).

Course plan (6)

08.09: Excursion:•Narva power plants

09.09: 17, 18 lectures:•Gas turbines•Biomass conversion process for energy recovery•Waste to energy conversion.

Course plan (7)

12.09: SEMINAR:•SEMINAR (1-st part)

13.09: SEMINAR:•SEMINAR (2-nd part)

xxx.09: EXAM

SEMINAR

Topic:Environmental problems, which appear due to the energy conversion (everyone makes a presentation, length ca 15min)

Deadline: 09.sept (by e-mail asiirde@staff.ttu.ee)

Oral speech: 12. and 13. sept

References• „Energy Efficiency“, F.Kreith, R.E.West; CRC Press

• „Sustainable Energy Systems Engineering“, P.Gevorkian; McGraw-Hill book company

• „Principles of Energy Conversion“, A.W.Culp jr; McGraw-Hill book company

• „Energy Systems and Sustainability“, G.Boyle, B.Everett, J.Ramage; Oxford University Press

• „Energy Conversion“, D.Y.Goswani, F.Keith; CRC Press

1. and 2. Lectures (29.08)

Description of the courseIntroduction, history of energy conversionEnergy classification, sources

• Global energy consumption in the last half-century has increased very rapidly and is expected to continue to grow over the next 50 years.

• In is expected to see significant differences between the last 50 years and the next.

• The past increase was stimulated by relatively “cheap” fossil fuels and increased rates of industrialization in North America, Europe and Japan, yet wile energy consumption in these countries continues to increase, additional factors have entered the equation making the picture for the next 50 years more complex.

• Additional complicating factors include the very rapid increase in energy intensity of China and India (countries representing about a third of the world’s population).

• On the positive side, the renewable energy technologies are finally showing maturity and the ultimate promise of cost competitiveness.

Introduction

• Energy conversion engineering (or heat-power engineering) has been one of the central themes in the development of the engineering profession.

• Energy conversion can and must play an important role in future energy use and te consequent impact on the environment.

• It is concerned with the transformation of energy from sources such as fossil and nuclear fuels and the sun into conveniently used forms such as electrical energy, rotational and propulsive energy, and heating and cooling.

Introduction (II)• Then came the oil embargo of the 1970s, high fuel

prices…..

• The limitations of the Earth’s resources and environment started to come into clearer focus.

• The public and legislatures began to recognize that air pollution produced by factories, power plants, and automobiles and other forms of environmental pollution were harmful.

Introduction (III)

• These and other influences have been helping to create a more favorable climate for consideration, if not total acceptance, of energy conversion alternatives and new concepts.

• Examples are combined steam and gas turbine cycles, rotary combustion engines, solar and windmill power farms, stationary and vehicular gas turbine power plants, cogeneration, photovoltaic solar power, turbocharged engines, fluidized-bed combustors, and coal-gasification power plants.

• Since oil comprises the largest share of world energy consumption and may remain so for a while, its depletion will cause a major disruption unless other resources can fill the gap.

• Natural gas and coal production may be increased to fill the gap, with the natural gas supply increasing more rapidly than coal.

• The increase in coal consumption will worsen the global climate change situation.

• Although research is going on in CO2 sequestration, it is doubtful that there will be any large-scale application of this technology anytime in the next 20-30 years.

• It is clear that in order to meet the ever growing energy needs of the world, we will need to use all of the available resources including fossil fuels, nuclear and RE sources for the next 20-40 years.

• However, we will need to convert these energy resources more efficiently.

• It is also clear that renewable resources will have to continue to increase their share of the total energy consumption.

Some Significant Events in the History of Energy Conversion

• The historical progress of industry and technology was slow until the fundamentals of thermodynamics and electromagnetism were established in the ninteenth century.

Conclusion

• Since energy conversion engineering is deeply rooted in thermodynamics, fluid mechanics, and heat transfer, these disciplines are necessary for understanding, analysis, and design in the field of energy conversion.

Energy:

Forms and Changes

What is energy

• Energy is the power to change things. It is the ability to do work.

• Energy lights our cities, powers our vehicles, and runs machinery in factories. It warms and cools our homes, cooks our food, plays our music, and gives us pictures on television.

• Joule - A unit of energy. One joule equals 0.2388 calories

Nature of Energy

• Energy is all around you!

–You can hear energy as sound.

–You can see energy as light.

–And you can feel it as wind.

Nature of energy

• You use energy when you:–hit a softball.– lift your book bag.-…………...

Living organisms need energy for growth and movement

Nature of energy• What is energy that it can be involved in so

many different activities?

– Energy can be defined as the ability to do work.

– If an object or organism does work (exerts a force over a distance to move an object) the object or organism uses energy.

Energy and Work

• Because of the direct connection between energy and work, energy is measured in the same unit as work: joules (J).

• In addition to using energy to do work, objects gain energy because work is being done on them.

Heat and WorkHeat and Work Are Not Properties

Mechanics teaches that work can change the kinetic energy of mass and can change the elevation or potential energy of mass in a gravitational field. Thus work performed by an outside agent on the system boundary can change the energy associated with the particles that make up the system. Likewise, heat is energy crossing the boundary of a system, increasing or decreasing the energy of the molecules within.

Thus heat and work are not properties of state but forms of energy that are transported across system boundaries to or from the environment. They are sometimes referred to as energy in transit. Energy conversion engineering is vitally concerned with devices that use and create energy in transit.

Heat is not energy

2 kJ thermal energy

2 kJheat

2 kJ thermal energy

Heat and Work

• In addition to using energy to do work, objects gain energy because work is being done on them.

• Because of the direct connection between energy and work, energy is measured in the same unit as work: joules (J).

Energy forms

The five main forms of energy are:

–Heat ?

–Chemical

–Electromagnetic

–Nuclear

–Mechanical

Heat Energy- (internal energy)

• The internal motion of the atoms is called heat energy, because moving particles produce heat.

• Heat energy can be produced by friction.

• Heat energy causes changes in temperature and phase of any form of matter.

Chemical Energy

• Chemical Energy is required to bond atoms together.

• And when bonds are broken, energy is released.

Fuel and food are forms of stored chemical energy.

Electromagnetic Energy• Power lines carry electromagnetic energy into your home

in the form of electricity.

• Electromagnetic Energy

• Light is a form of electromagnetic energy.

• Each color of light (Roy G Bv) represents a different

amount of electromagnetic energy.

• Electromagnetic Energy is also carried by X-rays, radio

waves, and laser light.

Mechanical Energy

• When work is done to an object, it acquires energy. The energy it acquires is known as mechanical energy.

• When you kick a football, you give mechanical energy to the football to make it move

Energy Conversion

• Energy can be changed from one form to another. Changes in the form of energy are called energy conversions.

Conversion

All forms of energy can be converted into other forms.– The sun’s energy through solar cells can be converted

directly into electricity.– Green plants convert the sun’s energy (electromagnetic) into

starches and sugars (chemical energy).– In an automobile engine, fuel is burned to convert chemical

energy into heat energy. The heat energy is then changed into mechanical energy.

Chemical Heat Mechanical

Other energy conversions

– In an electric motor, electromagnetic energy is converted to mechanical energy.

– In a battery, chemical energy is converted into electromagnetic energy.

– The mechanical energy of a waterfall is converted to electrical energy in a generator.

States of Energy

• The most common energy conversion is the conversion between potential and kinetic energy.

• All forms of energy can be in either of two states:– Potential– Kinetic

States of Energy

Kinetic and Potential Energy:

• Kinetic Energy is the energy of motion.

• Potential Energy is stored energy.

Kinetic Energy

• The energy of motion is called kinetic energy.

• The faster an object moves, the more kinetic energy it has.

• The greater the mass of a moving object, the more kinetic energy it has.

• Kinetic energy depends on both mass and velocity.

KE

KE= (mass x veocity2) x 0.5

• What has a greater affect of kinetic energy, mass or velocity

Potential Energy• Potential Energy is stored energy.

– Stored chemically in fuel, the nucleus of atom, and in foods.

–Or stored because of the work done on it:• Stretching a rubber band.•Winding a watch.• Pulling back on a bow’s arrow.• Lifting a brick high in the air.

Gravitational Potential Energy

• Potential energy that is dependent on height is called gravitational potential energy.

The Law of Conservation of Energy

Energy can be neither created nor destroyed by ordinary means.

– It can only be converted from one form to another.– If energy seems to disappear, then scientists

look for it – leading to many important discoveries.

Law of Conservation of Energy• In 1905, Albert Einstein said that mass and

energy can be converted into each other.

• He showed that if matter is destroyed, energy is created, and if energy is destroyed mass is created.

E = MC2

where E is energy, M is mass, and C is the speed of light in a vacuum

4-meter-tall sculpture of Einstein's 1905 E = mc2 formula at the 2006 Walk of

Ideas, Berlin, Germany

The different sources of energy

The different sources are:-

1.Fossil fuels 2.Hydro power plant3.Biomass4.Wind energy5.Solar energy6.Geo thermal energy 7.Ocean thermal energy8.Tidal energy9.Wave energy10.Nuclear energy

RENEWABLE- NON-RENEWABLE

• RENEWABLE: --CAN BE REGENERATED IN A RELATIVELY SHORT PERIOD OF TIME; UNLIMITED

• NON-RENEWABLE: --CAN NOT BE REPLACED IN A SHORT AMOUNT OF TIME; LIMITED

Fossil fuels• Coal, oil and gas are called "fossil fuels" because they have been

formed from the organic remains of prehistoric plants and animals.• Crude oil (called "petroleum") is easier to get out of the ground

than coal, as it can flow along pipes. This also makes it cheaper to transport.

• Natural gas provides around 20% of the world's consumption of energy, and as well as being burnt in power stations, is used by many people to heat their homes. It is easy to transport along pipes, and gas power stations produce comparatively little pollution.

• Fossil fuels are not a renewable energy resource. Once we've burned them all, there isn't any more, and our consumption of fossil fuels has nearly doubled every 20 years since 1900. This is a particular problem for oil, because we also use it to make plastics and many other products.

Biomass• Biomass is a renewable energy resource derived from the

carbonaceous waste of various human and natural activities. It is derived from numerous sources, including the by-products from the timber industry, agricultural crops, raw material from the forest, major parts of household waste and wood.

• Biomass does not add carbon dioxide to the atmosphere as it absorbs the same amount of carbon in growing as it releases when consumed as a fuel. Its advantage is that it can be used to generate electricity with the same equipment or power plants that are now burning fossil fuels.

• At present, biogas technology provides an alternative source of energy in rural India for cooking. It is particularly useful for village households that have their own cattle. Through a simple process cattle dung is used to produce a gas, which serves as fuel for cooking. The residual dung is used as manure.

Wind energy• Wind energy is the kinetic energy associated with the

movement of atmospheric air. It has been used for hundreds of years for sailing, grinding grain, and for irrigation. Wind energy systems convert this kinetic energy to more useful forms of power.

• Wind turbines transform the energy in the wind into mechanical power, which can then be used directly for grinding etc. or further converting to electric power to generate electricity. Wind turbines can be used singly or in clusters called ‘wind farms’. Small wind turbines called aero-generators can be used to charge large batteries.

Solar

• A solar cell or photovoltaic cell is a machine that converts sunlight directly into electricity by the photovolts effect.

• Photovoltaics is the field of technology and research related to the application of solar cells in producing electricity for practical use.

• The photovoltaic effect, which causes the cell to convert light directly into electrical energy, occurs in the three energy-conversion layers.

Solar heating• Solar heating systems are generally composed of

solar thermal collectors, a fluid system to move the heat from the collector to its point of usage.

• The system may use electricity for pumping the fluid, and have a reservoir or tank for heat storage and subsequent use.

• The systems may be used to heat water for a wide variety of uses, including home, business and industrial uses.

• In many climates, a solar heating system can provide up to 85% of domestic hot water energy.

• In many northern European countries, combined hot water and space heating systems are used to provide 15 to 25% of home heating energy.

Ocean Thermal Energy• The main objective of ocean thermal energy or Ocean Thermal Energy

Conversion (OTEC) is to turn the solar energy trapped by the ocean into useable energy.

• This kind of energy is found in tropical oceans where the water temperature differs from surface to deeper into the sea. On the ocean surface it can be at least 20 C hotter or cooler than the temperature at a deeper sea level.

• Three approaches, open cycle OTEC, closed cycle OTEC and hybrid cycle OTEC have been created in the past fifty years.

• The variety of products and services are the major advantage of OTEC plants. Ocean thermal is also relatively clean and will not produce more pollutants that contribute to global warming.

• OTEC plants are most suitable for islands around the tropical region of the east Pacific Ocean. This is because OTEC plants can provide both energy and pure water at the same time with a relatively low cost. It is also because the ocean in that region has greater temperature differences, which is about 24 oC.

Wave energy• In many areas of the world, the wind blows with enough

consistency and force to provide continuous waves. There is tremendous energy in the ocean waves.

• WAVE POWER DEVICES extract energy directly from the surface motion of ocean waves or from pressure fluctuations below the surface.

• Wave technologies have been designed to be installed in nearshore, offshore, and far offshore locations.

• While all wave energy technologies are intended to be installed at or near the water's surface, they differ in their orientation to the waves with which they are interacting and in the manner in which they convert the energy of the waves into other energy forms, usually electricity.

Geothermal energy

• Geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity.

• Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth

Nuclear energy

• Changes can occur in the structure of the nuclei of atoms. These changes are called nuclear reactions. Energy created in a nuclear reaction is called nuclear energy, or atomic energy.

• When the nucleus splits (fission), nuclear energy is released in the form of heat energy and light energy.

• Nuclear energy is also released when nuclei collide at high speeds and join (fuse).

Vocabulary Wordsenergymechanical energyheat- thermal energychemical energyelectromagnetic energynuclear energykinetic energypotential energygravitational potential energyenergy conversionLaw of Conservation of EnergyRENEWABLENON-RENEWABLEFossil

THANK YOU FOR YOUR ATTENTION!

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