Video Transcript
In a gas-fired power station,
natural gas is combusted with blank. The energy released from this
reaction is used to heat water in a boiler to produce blank. This steam is used to drive
blank, which are connected to blank. The electrical output of these
generators is transferred to the national grid.
Now, our mission, should we
choose to accept it, is to fill in the blanks in this statement. As we read the information that
is given to us, we can see that this question is about a gas-fired power station
and how it works. In our first sentence, we’re
told that natural gas, the fuel for this kind of power station, is combusted
with some other ingredient. Now, to figure out what this
other ingredient is, we can think of combustion, burning, in general.
Say that we have a candle
that’s burning. And then, we take a glass, turn
it upside down, and then put the glass over the top of the candle. If we do that and keep the
glass there, eventually the flame will die out, and the burning will stop. The reason this happens is
because we’ve removed a necessary ingredient for combustion. It comes from the air around
the candle. And that ingredient is
oxygen. Oxygen is a necessary
ingredient for combustion, or burning, to happen. So, we write that word in our
first blank. That’s what natural gas is
combusted with.
Our statement goes on to say
that the energy released from this reaction is used to heat water in a boiler to
produce blank. Alright, so, so far, what we
have is natural gas combining with oxygen and being combusted. And now, we’re told that the
energy released from this reaction is used to heat water in a boiler. Now, when water is heated
enough to the point that it leaves its liquid phase, it becomes a gas. The name for that is steam. Our statement tells us that the
water being heated is in a boiler. In other words, it’s the
intention to transfer this water from being a liquid to being a gas. And, as we said, that gas is
called steam. So, that’s what we’ll put in
our second blank.
Now, the steam in the power
station is typically produced in order to create pressure in a gigantic cylinder
known as a turbine. Pushed by the high-energy
steam, this turbine begins to rotate, or turn around its axis. This tells us how to fill in
the third blank in our statement. The steam is used to drive
turbines. It’s important to know, though,
that rotating turbines by themselves don’t produce electricity. They have to be connected,
typically by a rotating shaft, to a device called a generator.
When the turbine rotates, it
causes the central portion of the generator to spin as well. When this component is
rotating, the generator is able to produce electricity. So, then, generators are what
are connected to turbines. And that word, generators, goes
in our last blank.
Now, that all the blanks are
filled in, let’s read our statement in its finished form. In a gas fired-power station,
natural gas is combusted with oxygen. The energy released from this
reaction is used to heat water in a boiler to produce steam. This steam is used to drive
turbines, which are connected to generators. The electrical output of these
generators is transferred to the national grid.
