Summary thermodynamics energy technology (chapters 0-4)

SUMMARY ENERGY TECHNOLOGY
1. INTRODUCTION
1.1. E NERGY CONSUMPTION

 The consumption of energy by mankind is large and increasing and is mainly driven by fossil fuels.
 There is a strong correlation between the Social Progress Index and the energy consumption per
capita.
 The tonne of oil equivalent (toe) is the amount of energy released by burning one tonne of oil.
 When considering coal there is an equilibrium between mining and consumption, when considering
oil there is not.


1.2. E NERGY AND POWER

 Work (W) is delivered to a body when a body moves over a distance (s) by applying a force (F) to
it, and W = F * s, and thus the unit 1J = 1N * 1m
o Work, energy, heat (quantity) is expressed in Joule (unit)
W
 Power (P) is the amount of work delivered in one unit of time, and P = and thus the unit =
∆t
1J
1W =
1s

Quantity Force (F) Distance (s) Work (W) Power (P)

Unit Newton (N) Meter (m) Joule (J) Watt (W)

 Consider an electrical voltage U (Volt) loaded by a resistor R (Ohm), then a current I (Ampere) is
U
flowing and I =
R
 The voltage source then generates a power (or the resistor consumes a power), and P = U * I and
thus the unit 1W = 1V * 1A
o When considering a time interval t, the voltage source sends an amount of energy:
W = P * t = U * I * t
o The energy or work is expressed in 1J = 1W * 1s
 1 kWh = 3 600 000 W * s = 3 600 000 J


1.3. E LECTRICAL ENERGY CONSUMPTION

 The electrical energy consumption is also increasing.




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, 1.4. F INITE ENERGY RESOURCES

 The steady increase of the worldwide energy consumption implies several challenges:
o Ensuring a security of supply
o Keeping the energy affordable
o Facing environmental problems and climate change
 Since mankind consumes fossil fuels much faster than nature can produce them the depletion of
the energy resources arises.
o An indication is obtained by calculating the ratio between the reserves R and the current
production P.
 The Hubbert curve approximates the production rate of a resource over time.
o Has three components: A rise from 0 production, A quick increase till
the Hubbert peak has been reached, A drop from the peak.
 Estimated Ultimate Recovery = EUR = the total amount of oil which is potentially recoverable or has
already been recovered from the reserve.


1.5. R EAL LIFE IMPACT OF ENERGY SUPPLY

 Security of supply: very often, energy is imported from foreign countries. This gives power to the
exporting countries.
 Keeping the energy affordable: in general energy prices are fluctuating and increasing.
 Environmental problems and climate changes


1.6. T HE FUTURE

 Many opinions and scenarios exist.


2. THERMODYNAMICS: INTRODUCTION & FIRST LAW
2.1. T HERMODYNAMICS : I NTRODUCTION

 Thermodynamics is the branch of physical science that deals with the relations between heat and
other forms of energy, and by extension, of the relationships between all forms of energy.
 Notice the central importance of heat.


2.2. T HERMODYNAMICS : B ASIC CONCEPTS 1

 System = a quantity of matter or a region in space chosen for study.
 Surroundings = the mass or region outside the system.
 Boundary = the real or imaginary surface that separates the system from its surroundings.
 Isolated system = neither mass nor energy can cross the selected boundary.
 Closed system = only energy can cross the selected boundary.
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