I just had an idea so I need Veeky Forums to explain to me why I'm retarded...

I just had an idea so I need Veeky Forums to explain to me why I'm retarded. Why is water the only thing power plants boil to turn their turbines? If they had some other liquid with a lower boiling point (but still liquid at room temperature), would they not save significant amounts of energy in the process of converting whatever it is they're burning into electrical energy?

water has a shit ton of thermal capacity, is abundant, and is fairly non corrosive/reactive. there are other working fluids like ammonia or CO2 but nothing really tops H2O.

It's not about the boiling, it's about the pressure of steam, also water is cheap. Really cheap, compared to other stuff.

>abundant
I guess that's the name of the game, it would be too expensive to use something else in large quantities.

Funny fact is, that if you evaporate water, it goes up, and what condensates on top, goes down...

>I just had an idea

Because the rankine cycle is based on phase change, and if something with a low heat of vaporization were to be used, like alcohol, you would get lower power output for a given temperature differential.

Because large scale solid-state thermoelectric generation hasn't been done because it's less efficient than steam water, requires highly specialized materials, and isn't as easy to instantly shut off if there's an accident.

>Why is water the only thing power plants boil to turn their turbines?
it's not

Once the shit gone through the turbine you need to cool it down again. Nice thing about water is you can just return it to where you got it and forget about cooling it yourself.

Pump water from lake. Heat it to steam. Turn turbine. Condense it and send it back to lake. The lake is left with the hot water. Only side effect is that it fucks up the ecosystem but people buying electricity don't care.

It isn't a bad idea but water is cheap. It would be something to consider in space travel for nuclear power. Subs use steam because, well, why wouldn't they? Space ships? That would be something to look at.

>Why is water the only thing power plants boil to turn their turbines?
There are development projects underway to use more efficient working fluids, like helium (doesn't liquefy), mercury (boils at a higher temperature), supercritical carbon dioxide (occupies a weird state between liquid and gas), and dinitrogen tetroxide (doesn't just boil, but the molecules split in half on further heating).

>If they had some other liquid with a lower boiling point (but still liquid at room temperature), would they not save significant amounts of energy in the process of converting whatever it is they're burning into electrical energy?
At start-up, yes, but that's a trivial consideration in a closed-cycle plant. That energy's still there when they put it through again.

This practice is called thermal pollution and is highly regulated. Large facilities that do this are only allowed to dump the water back if it's within a single digit temperature difference.

what do you mean fairly?

It's not sulfuric acid, but it ain't exactly motor oil either. Water's corrosiveness is manageable.

You realize that they don't use pumped water to turn turbines, correct? They use it as a a cooling system for the water that's actually going through the reactor or boiler. Basically they have a heat exchange that makes it so during the cooling step, they cycle cold water around their cycling water to rapidly water-cool their cycling water.

water is liquid at room temperature, hello. The amount of energy put into condensing a gas to a liquid and continuing this cycle would be counterproductive.

It's not about boiling point, it's about the amount of energy contained within the fluid. Water holds more energy per unit temperature increase than any other comparable fluid.

What?
- The "Primary" (dirty loop) is "cooled" by pumping the reactor's pressurized water (doesn't boil) through a heat exchanger (steam generator)
- The secondary (clean loop) makes steam (heat exchanger / steam generator) to turn the turbines. The steam then goes through a condenser (which is also a form of heat exchanger) to turn the steam back into water. This "condensate" is cooled in the condenser by another source of water (fresh or sea water).
- in commercial reactors, this "third loop" (clean) is cooled in the cooling towers. The large surface area at the bottom of the towers (US (and others) design) allows the natural convection of heat upward in the towers.
It just takes the heat away and makes pretty non radioactive clouds (not smoke) floating away from the cooling towers (not smoke stacks).

Pretty simple really

>pic related

Supercritical CO2 as a working fluid is promising but our level of technology is not there yet.

That and safety, imagine if your university used ammonia for its boiler plants and it suffered a pipe blowout in a building heat exchanger, whoops just killed a whole building.

CO2 tops H2O, you can make much smaller turbines

>when high-functioning autistic boys grow up

Someone actually posted a genuine question for once and you just name-call? You can fuck off back to whatever subreddit you came from.