Transcript processes

UNIT 7
Vocabulary
• Conventional Power Plants:
– Thermal power plant
– Nuclear power plant
Grammar and functions
•
•
•
•
Describing processes: Method&purpose(U6)
Active vs. Passive
Revision of vb tenses (regular & irregular vbs)
Revision of grammar structures
DESCRIBING PROCESSES
IMPORTANT EXPRESSIONS
COMMON VERBS
•
•
•
•
•
Use of the PASSIVE
To carry out / develop a process
The process takes place / occurs / happens
This ALLOWS / CAUSES it TO occur (U5)
PREVENTS it FROM occurring (U5)
METHOD (U6) (HOW?)
•
•
•
PASSIVE + BY = por
by means of ... / (by) using ... / With the help of ... Through … mediante, por
medio de, con ….
One method for /way of ... (+ verb –ING) .... is to ....
PURPOSE (U6) (WHAT FOR?)
In order to, so as to, to + INF = Para + Inf
TRANSLATION
• GREAT/LARGE AMOUNTS OF ELECTRICITY CANNOT BE
GENERATED UNLESS ) a coil rotates in a magnetic field
• that IS DONE BY MEANS OF/WITH A TURBINE (that is) connected to a
generator
•
The turbine converts the kinetic or thermal energy of a flowing fluid INTO useful
rotational energy
•
A generator contains the stator, WHICH IS THE MAGNET and a rotor, WHICH
IS THE COIL
• WHEN/AS THE ROTOR TURNS the wires cut the lines of force in the magnetic
field of the stator
• PRODUCING AN ALTERNATING CURRENT
•
The enormous size of modern generators and the speed AT WHICH the rotor can
turn mean that electric power of very high voltage can be produced
• AS MUCH AS HALF A MILLION VOLTS can be transmitted over high
voltage lines to substations
• IN WHICH THE VOLTAGE IS REDUCED WITH / BY ( BY MEANS OF) /
BY USING TRANSFORMERS
TRANSLATION
• The rotor is turned BY/ BY MEANS OF / WITH a turbine,
• a huge machine (that is ) moved by water or STEAM IN POWER
PLANTS
• ACCORDING TO/DEPENDING ON THE SOURCE OF ENERGY (that
is) USED to move the turbine
• By far, the most important sources of power are those (sources) (which
are) produced by THE CHEMICAL ENERGY OF/FROM FOSSIL
FUELS, LIKE/SUCH AS OIL OR COAL , nuclear energy and the
potential energy of waterfalls.
• Fossil-fueled power plants contain a boiler WHICH WORKS LIKE a big
kettle.
• AFTER BEING HEATED (UP) TO A CERTAIN TEMPERATURE, the
steam is passed through small holes, increasing the speed of the
water molecules
• The fast moving molecules hit the blades of the turbine and MAKE IT
(THEM) TURN / CAUSE THEM TO TURN.
VIDEO: Coal PP (Utube 0-1:50)
1. Where is half of world’s electricity generated? By coal power plants
2. How many are there in the world? Close to 3,000 large coal PP
3. How this controversial yet indispensable PP works, i.e. how to convert the
energy stored in the COAL to ELECTRICITY
4. To increase burning efficiency a POWDERED COAL and air MIXTURE
enters the furnace
5. During the burning process the chemical energy stored in the coal is
released as heat to create high temperatures inside the furnace.
6. This heat passes to the water inside the coils located in the furnace.
7. The hot water is then forced to move to the boiler where it evaporates
and generates high-pressure steam.
8. The high-pressure steam is taken to the steam turbine
9. The energy inside the steam is converted into mechanical energy.
10. This mechanical energy is then transferred to the generator where it will
be converted into electricity
11. The generated electricity is finally transferred to the grid through a
transformer and is ready to be consumed by the public
ACTIVE vs PASSIVE
Passive voice:
Typical in TECNICAL ENGLISH, particularly when describing processes.
The pyramids were built thousands of years ago.
The samples were analysed in the laboratory
The mixture is fed into the pulveriser.
NOTE:
- Some verbs have NO PASSIVE (intransitive, impersonal) =
e.g. RAIN, AGREE, APPEAR, ARRIVE, OCCUR, HAPPEN, BECOME,
RISE, BELONG, CONSIST (of), DEPEND, EXIST, DIE, FALL, LIVE,
WAIT, HAVE, modals (CAN, MAY, MUST)
– Be careful with Spanish expression “se + vb”:
e.g. se lava las manos = he washes his hands;
Polos opuestos se atraen = unlike poles attract each other
The reaction spreads out very quickly
AGENT => BY (por) = The system was developed BY the engineers of the plant
• if an object = BY / BY MEANS OF / USING / WITH / THROUGH
e.g. : The system was developed BY / BY MEANS OF / USING a new technique
PASSIVE VOICE
TO BE (changing verb) + Past Part of MAIN VERB.
The system …..
•
•
•
•
•
•
•
•
•
PRESENT = IS
PRESENT CONT= IS BEING
PAST = WAS (WERE)
PRESENT PERFECT = HAS (HAVE) BEEN
+ DEVELOPED
PAST PERFECT = HAD BEEN
WITH MODAL VB = CAN/MUST BE
WILL / SHOULD = BE
GERUND = BEING
PAST PARTICIPLE = BEEN
PASSIVE VOICE
FOR = PREPOSITION (+ NOUN)= usually PARA
•
•
•
•
•
•
•
•
indicating a goal: PARA, DE, POR
the food for the party,
clothes for children,
to study for a test
cure for cancer
for more information, call …
time for dinner
to travel for pleasure
indicating a recipient : PARA
a gift for you
Indicating cause = BECAUSE OF : POR for fear of
en beneficio de : POR
he fought for his country
I did it for you
indicating duration : POR, DURANTE
he's going for two years
indicating a particular time : PARA, POR
the wedding is planned for April
that's enough for now
indicating amount or value : POR, DE a check for $100
EXPRESSIONS: FOR example; FOR instance, responsible FOR …,
suitable FOR ….., need FOR …, reason FOR …
FOR IS NOT USED TO INTRODUCE THE AGENT in THE PASSIVE
PASSIVE VOICE
POR
•
•
•
•
•
•
•
•
•
•
•
•
•
Por causa de => because of, due to I arrived late because of the traffic
Transito por un lugar = by, along through we went through the city center
I stopped by your house; along the coast
durante ( tiempo) => for, during they stayed there for a week
por medio de => by means of Voltage is changed by means of transformers
a través de => through Water flows through the pipes
AGENT OF THE PASSIVE=> BY The pyramids were built by the Egipcians
PARA: PARA + NOUN (usually FOR)
For somebody=> for
a present for you
For some purpose => for
the food is for the party what for?
indicating comparison => for
it's good for what it costs
Time => for, by, around an appointment for Monday it’ll be ready by April
Direction => to, towards they're heading towards the river to the right/left
PARA + INFINITIVO (Purpose) = To, In order to, so as to + INFINITIVE
he does it to annoy you ; in order not to be seen too young to understand
PARA QUE+ SENTENCE (Purpose) = so that
Position the test tube so that the metal is below the wáter
VERB TENSES
Nuclear energy is the energy (that is) RELEASED through the
fission or fusion of atomic nuclei.
In the process (that is) KNOWN AS nuclear fusion two light
atoms join together UNDER conditions of extreme HEAT
and PRESSURE (at LEAST 50,000,000 degrees Celsius)
until they merge, forming a new nucleus WHOSE mass is
only slightly smaller THAN the total masses of the nuclei
that FUSE together.
The opposite process is nuclear FISSION which MEANS
“splitting apart” or “dividing”.
If either nuclear fusion or fission TAKES place quickly, the
result is a sudden release of ENERGY but so far the only
one THAT can BE SLOWED down and CONTROLLED is
fission.
VERB TENSES
• However, only A FEW elements are suitable FOR use.
• When one of THESE elements is STRUCK/STRIKEN by a free
neutron, IT SPLITS / BREAKS/ IS BROKEN down INTO two
lighter nuclei, WHICH fly apart AT high speeds, colliding WITH
surrounding atoms.
• This kinetic energy IS CONVERTED INTO heat.
• AT the same time, two or three more neutrons ARE
RELEASED and one of THEM enters the nucleus of a
neighbouring atom, causing fission TO OCCUR again,….
• The reaction SPREADS very quickly with more and more
energy (that is) RELEASED.
• This IS REFERRED to as A “chain” reaction because the
splitting of each nucleus IS LINKED to another.
VERB TENSES
• If this reaction IS UNCONTROLLED, the result is an
atomic explosion like THAT (the explosion) (which was)
CAUSED by the atomic bombs of Hiroshima and
Nagasaki.
• However, the reaction can BE SLOWED down and that
is WHAT happens in a nuclear reactor or pile.
• Here the highly fissile material IS SURROUNDED BY a
substance that is non-fissile, FOR instance, graphite.
• This material IS CALLED A moderator.
• The neutrons LOSE some of THEIR energy through
COLLIDING with the atoms of the moderator and no
expansion IS PRODUCED .
• by SLOWING down the speed of the free neutrons, IT
makes it …. collide WITH the nucleus of a neighbouring
atom to continue the chain REACTION
VERB TENSES
• The major advantage of nuclear energy is that it DOES
NOT DEPEND ON any local factors.
• A nuclear reactor, UNLIKE conventional power plants,
DOES not have TO BE BUILT near a fossil-fuel source,
nor does it depend ON a large flow of water WHICH may
BE REDUCED during some seasons of the year.
VERBS (regular&irregular)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
TO DRAW
DREW DRAWN
TO SPREAD
SPREAD SPREAD
TO RAISE
RAISED
TO BUILD
BUILT BUILT
TO SPEND
SPENT SPENT
TO FIND
FOUND FOUND
TO MAKE
MADE MADE
TO SUPPLY
SUPPLIED
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
TO THROW
THREW THROWN
TO WRITE
WROTE WRITTEN
TO RISE
ROSE RISEN
TO HOLD
HELD HELD
TO BREAK
BROKE BROKEN
TO PUT
PUT PUT
TO BRING
BROUGHT BROUGHT
TO GIVE
GAVE GIVEN
VERBS (regular&irregular)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
TO TAKE
TOOK TAKEN
TO SPLIT
SPLIT SPLIT
TO WIND
WOUND WOUND
TO FEED
FED FED
TO SET
SET SET
TO DRIVE
DROVE DRIVEN
TO ALLOW
ALLOWED
TO FLOW
FLOWED
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
TO KNOW
KNEW KNOWN
TO SHOW
SHOWED SHOWN
TO LEAVE
LEFT LEFT
TO STRIKE
STRUCK STRUCK/STRIKEN
TO LET
LET LET
TO SEE
SAW SEEN
TO CUT
CUT CUT
TO LEAD
LED LED
VIDEO: Nuclear reactor
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
URANIUM
the exact SIZE that is USED in the fuel rods.
This TINY pellet CONTAINS more ENERGY than 6 car loads of coal.
We have 20 MILLION of these pellets INSIDE the reactor vessel.
We call it the CORE.
Around the core, of course, there is WATER.
WATER is used as a COOLANT.
Now, … another set of rods called the CONTROL RODS.
These rods actually control the NUCLEAR REACTION.
What happens is this: …. that is when it is ACTIVATED,
with them gone, the NUCLEAR FUEL sets up a CHAIN REACTION
that PRODUCES a tremendous AMOUNT of HEAT,
that BOILS the WATER,
that turns to STEAM,
that TURNS the TURBINE,
that turns the GENERATOR, that PRODUCES ELECTRICITY.
GRAMMAR REVISION: THE NUCLEAR REACTOR
•
•
•
•
•
•
•
•
•
•
… place IN which a fission NUCLEAR reaction TAKES place.
It contains …in THE form of rods to produce the appropriate result.
The reactor consists OF a fuel, a moderator and A cooling system.
An instrument …neutron WHICH strikes the nucleus of an atom of
U-235.
The nucleus … which collide WITH other nuclei and split, and so on.
However, if no explosion occurs IT is because …is moderated BY a
non-fissionable material such AS graphite or heavy water.
This absorbs most OF the free neutrons and prevents them FROM
splitting too MANY nuclei too quickly.
The process releases great AMOUNTS of energy in the form of
heat.
This heat ….produced can be USED to generate electric power.
As the fuel … during ITS use inside the reactor, when IT is taken
…, IT is stored in the fuel pools, …, in general more THAN a year,
before sending IT to the processing plant.
LISTENING: comparison of fuels
•
•
•
•
•
•
•
•
•
•
•
•
•
•
about different fuels and processes. We’ve been told that nuclear power is
more efficient than conventional fossil fuels and we know that fossil fuels
are limited.
-Conventional fossil fuels, i.e., oil, coal and gas, and nuclear fuels, i.e.,
uranium and plutonium.
-different nuclear reactors and different conventional processes.
-Say a bucket holds 10 kg
Let’s look at the 2 million Kw power station.
2 million kw make 2,000 megawatts
That’s nuclear fuel
which converts all the matter in this fuel into energy.
it may last 8 ½ years. In fact, ….. with the hydrogen fusion reactor.
Only two weeks
- The next process is a fast reactor. …. natural uranium.
After three days. Now let’s look at conventional fossil fuels, shall we? ….
One hour?
-it will last 1/18th of a second. And the same goes with coal.
-In Europe, France, and then West Germany.
EXTRA VIDEO: HOW POWER PLANTS WORK
http://www.youtube.com/watch?v=GI7AhajfhWE
1. Most power plants produce what? Heat in order to generate steam to drive
turbines that generate electricity
2. Which are the main fuels? Nuclear fission, natural gas and coal
3. Which fuel is used in W C plant? Coal to produce heat
4. Furnace boiler: How does the system capture the heat? Using a system of
circulating water and steam
5. Process: Step 1
1. Which process takes place in the boiler? Combustion
2. Step 2: pulverized COAL is injected with a stream of AIR into the FURNACE through a
BURNER
3. Step 3: Burners IGNITE THE COAL-AIR MIXTURE -> maximum possible heat = AS MUCH
AS 1500ºC
6. The steam turbine generator: converts THE HEAT captured BY THE
STEAM INTO ELECTRICIAL ENERGY
1. Intense HEAT coming FROM THE FURNACE turns WATER RUNNING THROUGH THE
PIPES around the boiler INTO STEAM
2. Steam travels THROUGH MORE PIPES to THE TURBINE causing it TO SPIN and turn the
shaft of A GENERATOR, which CREATES ELECTRICITY
3. Another series of pipes ALLOWS THE STEAM TO COOL condensing back INTO WATER
heading back to THE BOILER where THE PROCESS BEGINS AGAIN in a continuous cycle