Steam Turbine's power production vs steam temperature

[Jarcionek]

I am studying Steam Turbine's and building various setups, but I cannot find an answer to a very simply question:

With the Aquatuner setup, if I am low on power, should I consume the steam at 125C or at 200C?

I have a number of setups like this volcano cooler:
https://steamcommunity.com/sharedfiles/filedetails/?id=2996011930

I am constantly low on power, burning wood and coal. I don't have the issue with heat deletion, each of these coolers gets the job done. However, to get the most power out of the steam, what temperature should the steam be?

I know that to get 850W I need at least 200C, below that the turbine will output less power, however it will work more often. At 226C and higher, I would have to start closing inlets.

[cswiger]

The most power-efficient temperature is 200 C.

However, trying to use an AT to cool a metal volcano is a remarkable waste of power. You can use the heat from the volcano output to heat steam to a usable temperature directly and gain lots of power without using an AT.

[JasonS]

200 C is optimal for power production, provided all 5 steam inlets are unblocked and the turbine can get the full 2kg of steam per second.

As far as this setup is concerned, is your aquatuner cooling the Volcano room? That's very energy inefficient. Instead you can fill the volcano room with Steam, attach the Turbine to the volcano room and directly cool the volcano with the Steam Turbine's output water. Depending on the type of metal that the volcano is producing, you may need additional steam turbines (Gold makes the least heat, Aluminum the most). With this setup, the only thing the aquatuner has to do is cool the Steam Turbines, which will save a lot of power.

As a bonus, for more efficient heat transfer (and less duplicant labor), you can have an auto sweeper place the hot metal on a conveyor rail before it leaves the steam room. A conveyor shutoff and conveyor rail thermal sensor can be used to regulate when the metal is allowed to leave the steam room.

https://steamcommunity.com/profiles/76561198010785405/screenshot/2036238705667866735/

[Jarcionek]

I was planning something like this, but without a buffer with cold water, I need to take care of how much water to put into this system (I want it to be closed, without a steady supply of water).

Take for example Magma Volcano: 268.8kg/s of Magma at 1726.9C for 63s - that's almost 17t of magma. If I want to cool it down to around 200C, I would need at least 75t of water. (at temperature 125C). The turbine is consuming 2kg/s, the time between eruptions is 8710s, so it will process only ~17.5t of water... I would need 4 turbines to handle that.

No end-game materials yet, the best I can do is steel, so the temperature limit is 275C. If I exceed that, sweeper, miner, aquatuner and whatever else or gonna get damaged.

EDIT: Ok, I think I should have looked at a resource volcano. Aluminium volcano erupts not only 600kg at once, but also has a lower SHC. 2-2.5t of steam at temperature 125C will be enough to cool that amount to 200C. Eruption is more frequent, every 1053s, but 2t of water is just about what one turbine can process. With two turbines there should be no problem.

[XceptOne]

I get your definition of efficient here is get every J of power from the produced heat available. This means your answer is:
Any steam temperature is fine, as long as it never exceeds 200℃.
Going above 200 wastes power, keeping below it does not.

200℃ / 850W is not really the optimal production point for a steam turbine. It is the upper limit of what a steam turbine can produce.
Within that range the turbine will produce with the same efficiency no matter the current output power/input temperature. You will get a constant 0.969W per kDTU heat that gets removed when condensing the input steam to 95℃ water.

Running a turbine at its' peak output actually has the risk of slightly exceeding the temperature window and thus losing a few Watts. So a peak output turbine is in danger of actually running less efficient than it would at any lower temperature.


About Aquatuners and Volacnoes: the others already told you ;) (For just getting it done, it definitely works, i've done worse. But it's probably a part of the answer to the question of why you have power problems to begin with)


Edit
Funfact about (the large) magma volcanoes: Over their whole active/dormancy cycle they will produce slightly more heat than what is needed to run two steam turbines nonstop. (You will want to store excess magma while the volcano is active, in order to use it to run your turbines while the volcano is dormant)

[cswiger]

Most metal volcanoes can be handled with two turbines; high-volume iron volcanoes and maybe a few rare edge cases will need three. Try for 20 kg / tile of steam and 50+ kg / tile of petrol on the floor.

Somewhat more might be safer for metals with a higher SHC like iron.

[Jarcionek]

Thank you all for the hints. It turns out that I was doing it all wrong <facepalm>

I have just tried out this little setup, and it works like a dream. There are some improvements to be made, especially around getting access to the Volcano (that gas pump that would be pumping out hot steam outside...)

https://steamcommunity.com/sharedfiles/filedetails/?id=2996669213

8 ton water buffer to maintain around 18C to cool the Steam Turbine and the produced Iron. Works only when needed.

https://steamcommunity.com/sharedfiles/filedetails/?id=2996669279

Iron from the steam chamber is taken only when temperature drops below 127C (i.e. I can initially cool it with 95C water coming from the Steam Turbine, and only when the turbine cannot work anymore, I move that iron through the water buffer that is cooled by Aquatuner).

https://steamcommunity.com/sharedfiles/filedetails/?id=2996669360

And as a test I have put it on the separate power network, so the whole system is self-powered and only gives excess energy to the main network. It has managed to cool that 8 tons of water from 27C to 18C, and now the Aquatuner rarely turns on.

https://steamcommunity.com/sharedfiles/filedetails/?id=2996669409

[Bobucles]

Temperature sensors and automated doors can open or close a steam turbine's inputs on demand. The 850W temperature is...
5 inlets: 200C
4 inlets: 226C
3 inlets: 270C
2 inlets: 357C
1 inlet : Don't, ever. There is an extra penalty with only 1, losing efficiency. The wiki also has wrong information on when it can be viable, because it doesn't register the % of heat being used.