Front | Back |
State that thermal energy may be
completely converted to work in a
single process, but that continuous
conversion of this energy into work
requires a cyclical process and the
transfer of some energy from the
system.
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Thermal energy may be
completely converted to work in a
single process, but that continuous
conversion of this energy into work
requires a cyclical process (thermodynamic cycle) and the
transfer of some energy from the
system (degraded energy).
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Explain what is meant by degraded
energy.
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Useless energy is that is transfered from a system
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Coal fired power station energy flow diagram
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Pic, |
Outline the principal mechanisms
involved in the production of
electrical power.
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(thermal, gravitational potential or wind) converting some kind of energy to kinetic energy, used to rotate a turbine. this turbine rotates the shaft of a generator to make electricity.Nuclear power stations - nuclear - chemical - kineticknow transformationsGravitational potential --> kinetic --> electric
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Construct and analyse energy
flow diagrams (Sankey diagrams)
and identify where the energy is
degraded.
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The forward arrow is the useful energy, the spliting arrows are the degraded energy, The thickness of the arrows are proportional to the scale of the energy transformation
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Coal fired power station skanky diagram
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Pic 9, 47, 3, 40 |
Identify the different world energy sources
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Fossil fuels - peat, coal, crude oil, oil shale, oil tar, natural gasnuclear energy, Geothermal, tidal, chemical energySun - primary source of world energy, directly or indirectly, due to radiant energy --> wind, ocean currents, wave action, water evaporation, precipitation, food, wood, biomass, fossil fuels (aka alternative energy source)Moon - tidesChemical energy - battery, fuel cellsNuclear energy - nuclear fission/fussion(only some) reactors
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Outline and distinguish between renewable and non renewable energy sources
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Renewable - a source of energy that could not be depleted with use, replenishes faster than you use itnon-renewable - a source of energy that could be depleted someday with use, using more of it faster than it is replenished
Coal - peat, sub-bituminous, bituminous, anthracite |
Coal (water, carbon, volatile)
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Table
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Oil shade and Oil Tar 2%
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Oil shade - kerogen found in Marl, expensiveoil tar - bitumen pyrolysed...
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Define energy density of a fuel
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Amount of potential energy stored in a fuel per unit mass or per unit volume, chemical potential energy/mass, measured in J g-1
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Energy density of fuels table
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Table
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Discuss how choice of fuel is influenced by its energy density
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- cost for production of electricity per kwh- energy density- political, social, econ issues- use and storage of the fuel (natural gas)- heating capability, rank (peat-anthracite)
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State the relative proportion of world use of hte different energy sources availabe
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Graph, oil, natural gass and coal at the top
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Outline the historical and geographical widespread use of fossil fuels
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Historical - Industrial Revolution- increase in population demands more fuel- inventions that requires fossil fuel use
Geographical - oil in Mid East and South America- lots of oil and coal reserves in every continent |