Why would you need cooling if you are trying to heat water up. It just seems like wasted energy to me.
In: Engineering
there is a thermodynamic principle at work here.
In order to extract energy into a useable form (like to inject it into the power grid), you don’t need something hot alone. What you need is a temperature *difference*. Something hot *and* something cold.
We hear water up because it produces steam, which spins turbines. It stands to reason that if we turn water into steam, we have no more water to heat up and turn INTO steam. We need to cool that water down so that it can be in liquid form again.
Part of the reason for the cooling towers are to regulate how hot the nuclear tubes get. When the tubes get too hot the heat keeps ramping up till it causes a meltdown. Which is what happened in Chernobyl.
You’re trying to heat water, yeah. But you *don’t* want literally everything else in your power plant to heat up to the point of melting, so you circulate more water through it to cool it down — then you reject that heat through the cooling tower. You also need to cool down the water you just heated up so that you can heat it up again.
Power plants turn liquid water in to steam. This steam turns turbines, like a gassy (not really a gas, but never mind) version of a water wheel.
When we turn water in to steam, it rises and goes off in to the atmosphere. This means we need more water to heat up to turn to steam.
Instead, we use big towers to let the water cool down and turn back to liquid (see above remark in parenthesis) so we can use it again without having to get fresh water.
Many of the other answers are correct, but some reasons we prefer to cool the steam and reuse the water is that it is treated and has a higher quality we like to maintain (proper pH and such). Reusing the water saves alot of money and makes maintaining water/steam quality easier.
We dont just keep the turbine exhaust as steam due to design/efficiency issues since we try and extract as much of the steams energy as we can to spin the turbine, and having it exhuast to a relatively cool low vacuum area (condenser) is easier on the turbine.q
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