Nuclear power and accumulator priority

[Serenity]

Accumulators have the lowest priority. I still have some solar fields with accus that wouldn't get used if nuclear is running all the time. I have sets of 12 heat exchangers in a row into some tanks, then a pump and then 20 steam engines. I hooked an SR-latch to an accumulator and only turn on the pump when the accumulators run low.

It works, but I'm not sure if this is really such a good idea. I guess it depends on the amount of steam storage, so if dropping accumulators consume all the steam and thus trigger a new fuel cycle I could buffer most of the newly generated steam

Yeah, I know with Kovarex enchrichment I don't really have to worry about nuclear fuel cells and I could just run everything of nuclear. And most people probably do just that. But ignoring all those accumulators seems wrong somehow

[Alavaria]

Yeah, something like the reactors only go if the steam storage is (nearly) empty, with a large enough steam storage to basically hold the entire output of one fuel cycle. Depending on your reactors though (adjacency bonus) a round of fuel might give quite a lot of steam.

Depending on reactor # as well, the reactors/heat exchangers can store a higher-or-lower fraction of the heat in themselves across their working range of 500 to 1000 degrees.

Ok I sat down and calculated.... if you use 4 reactors, and 32 heat exchangers:
one round of fuel = 96 GJ
the above buildings will store: 36 GJ
(between 500 to 1000 degrees, so this is optimistic)

The remaining 60GJ goes to storage, which over 200 seconds means 0.3 GW.
The 32 heat exchangers will in fact be able to transfer 0.32 GW.

60GJ of stored energy as 500deg steam needs 24.74 (so 25) full storage tanks.

So something like a 4-reactor square, 32 (or more) heat exchangers and 25 (or more) tanks would be a "backup" nuclear power option. If you are primarily generating it for use then you won't need as much storage (but still need the exchangers, more if you are going to draw more than 0.32 GW*)

*As the maximum output from a 4-reactor square is .48 GW, the above set up isn't running the reactors endlessly, but 32/48 of the time, the rest of that the reactors and heat exchangers are generating steam using their own heat.

[Serenity]

I'm not too worried about capturing all of the steam in tanks really. As you said figuring out how much is stored as heat in the reactors and pipes is difficult and changes as you continue to upgrade the power plant

I also want to keep each unit of 12 heat exchangers and 20 turbines self contained. With the way the fluid system works as of now this works a lot better than connecting everything together. As soon as steam can go anywhere it wants, unpredictable things can happen, such as not all turbines running at max load (the new fluid system should be a huge improvement here). I'm using 3 tanks for such a unit at the moment, which isn't really enough. In my creative test map I have a set up 4. But it seems to store much of a cycle for now. It's a decent enough middle ground between the plant running all the time and not wasting anything.

[BlueTemplar]

I have sets of 12 heat exchangers in a row into some tanks, then a pump and then 20 steam engines. I hooked an SR-latch to an accumulator and only turn on the pump when the accumulators run low.

It works, but I'm not sure if this is really such a good idea. I guess it depends on the amount of steam storage, so if dropping accumulators consume all the steam and thus trigger a new fuel cycle I could buffer most of the newly generated steam

Why wouldn't it be a good idea ?

Besides the fact that 1 nuke steam tank can store as much energy as 485 accumulators,
and one turbine can provide as much power as 19.4 accumulators,
with a 1.67-3.33 seconds internal steam buffer for power spikes,
so those accumulators that you already have might be negligible in comparison ?

[bobucles]

The raw energy storage of nuclear components is even higher. Every degree of an exchanger/heat pipe counts for 1MJ of energy, while every degree of a reactor core counts for 10MJ. Each of those components can store heat from 500-1000C, an equivalent of 500MJ or 5000MJ of storage.

The hard part is trying to make use of all the types of energy storage to give the best density and flexibility possible without any waste.

[BlueTemplar]

Sure, but the issue is that they are not connectable to the circuit network :
viewtopic.php?f=6&t=47141

[Alavaria]

Yes, you sorta have to mess around by using the value of your steam storage (you can read that) and using it (+combinators, deciders etc) to specifically turn on or off the inserters that would feed fuel (and override stack number, so each inserter only puts in one unit).

eg: If you were using 25 storage tanks, add a 26th between them and all the turbines, with a pump draining the 25 into the 26th. Then, when you see #26 get very low on steam you know the steam storage is basically empty.

This works because if your heat exchanger is above 500, it will try to make some steam, and so on. Thus, if you've pretty much emptied all your steam, either
1. You did it slowly, such that your reactors, heat pipes, and heat exchangers have all "emptied" their heat into steam, OR
2. You're really using a ton of power, in which case no fear of any wastage.


Check to see if this one works for you: https://wiki.factorio.com/Tutorial:Circ ... lear_power

Obviously a switch set to connect that to the energy grid only when accumulators are low is needed if you want that.

[BlakeMW]

Sure, but the issue is that they are not connectable to the circuit network :
viewtopic.php?f=6&t=47141

The way I handle that is to have a single steam tank, at the end of a heat exchanger line so it will be the first to start cooling. That steam tank is hooked up to the standard number of heat exchangers and turbines, but all other heat exchangers and turbines are in a 1:2 ratio. The moment the steam tank starts depleting (well, under 24k) fuel insertion is triggered.

[Serenity]

eg: If you were using 25 storage tanks, add a 26th between them and all the turbines, with a pump draining the 25 into the 26th. Then, when you see #26 get very low on steam you know the steam storage is basically empty.

I simply add all the steam together and divide by the number of tanks. The tanks aren't all equally full, but it works. As said I have each unit of heat exchangers, tanks and steam turbines self contained. That way steam can only ever move between 3 or 4 tanks (depending on how many I put down). The ones nearer to the turbines are more empty, but the average is still the same.

Nuclear

Nuclear1.jpg (146.57 KiB) Viewed 5303 times

Obviously a switch set to connect that to the energy grid only when accumulators are low is needed if you want that.

I don't don't like power switches for the power plants. For coal power I switch the water pumps instead. And for nuclear I switch a pump between the tanks and the turbines. If I don't draw power the turbines won't run. No need to disconnect anything.

When the pumps go off because of the high accumulator charge the residual heat in the system keeps making steam, refilling the tanks. The reactor is refilled when the tanks drop to a certain value

I tried building a more complicated system in creative mode where the heat exchangers and turbines are usually directly connected and the tanks are only filled on the side, but that needs a lot more pumps. And with this few tanks running the steam directly through them doesn't cause issues