## 0.15 Reactor Ratio

Post all other topics which do not belong to any other category.
Rage
Long Handed Inserter
Posts: 90
Joined: Sat Aug 09, 2014 2:08 am
Contact:

### 0.15 Reactor Ratio

First off, I've been up too long so someone should double check it.
Second, I need to explain the neighbor system.

The neighbor system is a way by which you can boost the effectiveness of a reactor by putting it next to another one.
Note, they must be adjacent and fully aligned with one another.
Aligning the heat system contacts woun't work.
reference a
For a reactor to get a neighbor boost a reactor has to be adjacent to it and online (fueled).
For our purposes a reactor is going to have a base value of one, meaning it's worth one reactor.
That would be one reactor, on it's own, not touching any other online reactors.
If you add the neighbor bonus to a reactors base value, you get it's effective value.
A neighbor bonus of 100% (1) give you an effective value of 2, or effectively two reactors in one.
The first image in Reference A is two reactors adjacent to each other, giving them each a neighbor value of 100% (1), giving you effectively 4 reactors for the price of two.
Note: The neighbor system only affects the heat output of a reactor, not the fuel usage rate.
Note: Neighbor bonus is only achieved from the N S E W neighbors, the diagonals don't count.
Note: The max effective value a reactor could have is 5, this would require a reactor on all 4 sides, this would also make it impossible to full automate.
Note: This is a linear bonus, a reactor with an effective value of 3 is worth 3 reactors alone as far as output is concerned.

Now on to ratios:
First, reactor to heat exchanger.
A reactor value of one, or a lone reactor, can support 4 heat exchangers in a stable manner.
When I say stable i mean you can run it 24/7 and it'll just keep on kicking so long as you can keep it fed.
You can run 5, possibly even 6, if it's a secondary system to support your main system at night or during power spikes.
Just realise if you're doing that, you'll want to let it get up to max heat (1000 C) before connecting it, that way you'll have the maximum buffer.
IMPORTANT NOTE: Heat exchangers do NOT produce any steam below 500C. If it's temperature is below that, it does nothing.
example
Now for heat exchanger to steam turbine.
The ratio here is a very annoying 60 heat exchangers to 103 steam turbines.
This is because the heat exchanger produces 103 units of 500C steam per second, and a steam turbine uses 60 of that.
For most smaller scale purposes, 1 heat exchanger to 2 steam turbines should work fine.
4 heat exchangers to 7 turbines will also work.
Note: When I say they'll work, I mean you woun't waste any steam.

Now to put it together.
For the full scale you'll need, a reactor value of 15, for 60 heat exchangers, for 103 steam turbines.
I say reactor value because you can get away with only 5 reactors.
I know because I'm tired after spending 4 hours figuring this all out and at least an hour setting up this mess:
the mess
I'm able to use only 5 reactors because of the neighbor system.
This system has the potential to output 597.4MW of power, my base doesn't use that much....

On the subject of heat pipes.
As far as i can tell, there's no inherent heat loss by using them.
They mainly make it take longer to get the system up to operating and max temperatures.
They can at times contribute to squirrely numbers and may have the potential to be used as a heat capacitor.

That is a system with two reactors, with a reactor value of 4, running 16 exchangers, running 32 turbines.
This has a stable output of 159.3MW, and a burst output of 185.6MW
I think I'm forgeting something....
oh yeah, they don't blow up at max heat.
exchangers don't mind being dry.
still think i'm forgetting something....

MeduSalem
Smart Inserter
Posts: 1407
Joined: Sun Jun 08, 2014 8:13 pm
Contact:

### Re: 0.15 Reactor Ratio

Interesting topic...

Somehow the neighbour system is kinda weird already. Makes it quite hard to actually find usable configurations because you basically want to have at least 2x2 blocks everywhere with 2 neighbours, but better would be 3 neighbours everywhere... to make the most out of it... but due to the way you have to input the fuel and also output the heatpipes there as well and lead them somehow out of the reactor layout it renders a lot of configurations unusable.

I have been playing around a bit as well and it feels like playing with Tetris Blocks.

Basically it's "make it a rectangle" or it doesn't really work. The fractal stuff the devs were talking about when introducing the Nuclear stuff doesn't really work out... like not at all.

But then again whatever... The power plant takes only a fifth or sixth of the space it would require for an equally performant Coal/Solidfuel powered plant.
Last edited by MeduSalem on Tue Apr 25, 2017 11:56 am, edited 1 time in total.

Rhamphoryncus
Fast Inserter
Posts: 119
Joined: Tue Jul 14, 2015 10:57 pm
Contact:

### Re: 0.15 Reactor Ratio

Reactors are 40 MW, heat exchangers are 10 MW, turbines are 5.8 MW. The lowest common multiple I could find is 1160 MW meaning 29 reactors, 116 heat exchangers, and 200 turbines. Twice your big example.

Some thoughts:
• 1160 MW is way too large for most bases. It wonder if it's chosen to avoid any obvious optimal layouts.
• Boilers and steam engines have some rounding bug so rather than a 1:2 ratio it's more like 1:1.99. Likely turbines do as well which could be why your big example was smaller than mine.
• Reactors are always at 100% fuel consumption, unlike boilers, so oversizing could be incredibly expensive for a small base.
• You could throttle back reactors by not providing fuel. They have to go from 15°C up to 500°C before they produce any power, however heat pipes (and adjacent reactors) average out the temperature and keep the extra reactors in a "ready to go" state even without fuel.
• I had one reactor stuck at 983°C even with 0 W of load. Seemed like something was draining off heat. After rebuilding it went away. Weird.

Ubertwink
Long Handed Inserter
Posts: 71
Joined: Sun Oct 18, 2015 5:47 pm
Contact:

### Re: 0.15 Reactor Ratio

Rage wrote:The ratio here is a very annoying 60 heat exchangers to 103 steam turbines.
29 heat exchangers to 50 turbines is an exact ratio.
290 MW is a little more than 7 base reactor values. Meaning you can go with 1x3 with a slight underpowering or 2x2 to saturate your OCD at a cost of extra uranium.

saturn7
Long Handed Inserter
Posts: 88
Joined: Wed Apr 27, 2016 6:14 pm
Contact:

### Re: 0.15 Reactor Ratio

Thanks for your post! I kinda needed a basic explanation how to set up reactors, and this provides it nicely.

werelord
Burner Inserter
Posts: 7
Joined: Tue Apr 25, 2017 6:17 pm
Contact:

### Re: 0.15 Reactor Ratio

Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Code: Select all

``````X  X  X
X  0  X
X  X  X
``````
In this case, the "O" reactor would be wasted; even though it would have 4 neighbors, there are no spots for heat pipe output, correct? (besides the fact that it couldn't be fueled)..

Cobrikhan
Burner Inserter
Posts: 9
Joined: Wed Apr 19, 2017 1:10 am
Contact:

### Re: 0.15 Reactor Ratio

werelord wrote:Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Code: Select all

``````X  X  X
X  0  X
X  X  X
``````
In this case, the "O" reactor would be wasted; even though it would have 4 neighbors, there are no spots for heat pipe output, correct? (besides the fact that it couldn't be fueled)..
Reactors do have 3 build in heat pipes connections on each side. The problem with your "dead reactor" is that it serves no purpose. If it's not fueled it doesn't add to the neighbor bonus of the 4 non-diagonal reactors. I'll use numbers to illustrate the multipliers

No Center Reactor- all get 2x neighbor bonus
Unfueled center reactor all get 2x Neighbor Bonus
2 2 2
2 - 2
2 2 2

Same output potential as bulding
2 2 2 2
2 2 2 2

Either way you have the effective output of 16 reactors
If you manually fuel and empty the center it becomes

2 3 2
3 4 3
2 3 2

This would produce a LOT of power at the cost of needing the player to baby-sit the whole setup. Also be very careful when over-building Nuclear because even if a reactor is not needed, heat is maxed across the system at 1000 degrees etc it is still burning Uranium at full speed. Reactors do not stop consuming fuel the way boilers do. This also raises the point that you would not want Nuclear as a backup power system. If you use SR Latches to control Emergency Power systems you would have your priority as Nuclear > Solar > Accumulators > Boilers.

Rage
Long Handed Inserter
Posts: 90
Joined: Sat Aug 09, 2014 2:08 am
Contact:

### Re: 0.15 Reactor Ratio

Rhamphoryncus wrote: A: Reactors are 40 MW, heat exchangers are 10 MW, turbines are 5.8 MW. The lowest common multiple I could find is 1160 MW meaning 29 reactors, 116 heat exchangers, and 200 turbines. Twice your big example.
B: You could throttle back reactors by not providing fuel. They have to go from 15°C up to 500°C before they produce any power, however heat pipes (and adjacent reactors) average out the temperature and keep the extra reactors in a "ready to go" state even without fuel.
C: I had one reactor stuck at 983°C even with 0 W of load. Seemed like something was draining off heat. After rebuilding it went away. Weird.[/list]
A: That would work if it was a simple power transfer system, but unfortunately (or fortunately) it's not. For reactor to heat exchanger it is, a reactor value of 1 produces 40MW of heat energy per second, and a heat exchanger uses 10MW of heat energy per second. The thing is, a heat exchanger output a specific amount of 500C steam every second, 103 units from my testing. This result in a exchanger to turbine ratio of 60:103. If you're looking for a 24/7 stable ratio, that's what you're after.
B: That is a possibility, though you're other reactors will loose their neighbor bonus, neighbor bonus requires and adjacent AND online neighbor, and they'll have trouble keeping everything at temp under load. It's something you'll have to keep an eye one. That being said, the system woun't loose heat if there's no load, and the only thing that can add load is a heat exchanger converting water to 500C steam.
C: The heat system is still a little squirely, I would presume that it'll become a bit more stable and predictable with time and updates. At the moment it works, it's just a little weird at time.
Ubertwink wrote:
Rage wrote:The ratio here is a very annoying 60 heat exchangers to 103 steam turbines.
29 heat exchangers to 50 turbines is an exact ratio.
290 MW is a little more than 7 base reactor values. Meaning you can go with 1x3 with a slight underpowering or 2x2 to saturate your OCD at a cost of extra uranium.
For most people that should work, but what I was going for in my testing was the exact ratio. Heat exchangers output 103 units of 500C steam per second and turbines use that at a rate of 60 units per second. 29 exchangers ouput 2,987 unit per second, and 50 turbines use 3000 per second. It'll work perfectly fine, but it's not what I was looking for in my testing.
werelord wrote:Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Code: Select all

``````X  X  X
X  0  X
X  X  X
``````
In this case, the "O" reactor would be wasted; even though it would have 4 neighbors, there are no spots for heat pipe output, correct? (besides the fact that it couldn't be fueled)..
In my big balanced example I set everything up so that each reactor supported it's fair share of heat exchangers, that being said, it may not be necessary. Reactors have a massive heat transfer rate, so long as you don't bottleneck in your steam pipes or your heat pipes, using a 3x3 should be entirely doable, you'll just have to fuel the center one by hand.
Cobrikhan wrote:
quote
You can reach the center reactor by hand in a 3x3 system. Also, the 8 reactor hollow box setup has a reactor value of 24, the 8 reactor 2x4 rectangle setup has a reactor value of 28, 3x3 has a value of 33. You're forgetting to include the base value, the neighbor system adds on. A neighbor system value of 200% (2) adds a reactor value of 2 to the base value of 1, getting you an effective value of 3. You are right though, they would all produce a lot of power, and would require a lot of support equipment to run and utilize. It would help if we had an in game way of managing the power priorities, but we don't, at least not in vanilla. At the moment it's Solar>Steam(both types)>Accumulators. Ideally we would have control, but hopefully the devs will at least change it to Steam Turbines>Solar>Steam Engines>Accumulators.

nak0604
Manual Inserter
Posts: 3
Joined: Thu Dec 31, 2015 11:32 pm
Contact:

### Re: 0.15 Reactor Ratio

How many centrifuges (probably spelled that wrong) do you have working on fuel. Out of the 20-30 minutes i spent messing around in sandbox I never got a single usable fuel chunk of uranium.

DOSorDIE
Fast Inserter
Posts: 248
Joined: Sat Oct 11, 2014 3:43 pm
Contact:

### Re: 0.15 Reactor Ratio

Cobrikhan wrote:
werelord wrote:Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Same output potential as bulding
2 2 2 2
2 2 2 2
Its not
2 2 2 2
2 2 2 2

its
2 3 3 2
2 3 3 2

Just saying

Dimanper
Inserter
Posts: 47
Joined: Sat Sep 17, 2016 9:50 am
Contact:

### Re: 0.15 Reactor Ratio

Cobrikhan wrote:This also raises the point that you would not want Nuclear as a backup power system. If you use SR Latches to control Emergency Power systems you would have your priority as Nuclear > Solar > Accumulators > Boilers.
I disagree. I think nuclear power is the best power system in the game right now to fulfill shortages in your main power production. It's just that everyone is talking about producing power immediately from the steam right after it is produced in heat exchangers, when in reality you can store that steam in storage tanks and produce as much power as you need at any given time later.
For example, one can use setup like this:
- 8 nuclear reactors (2x4, 3.5 efficiency)
- 112 heat exchangers (4x12 + 4x16)
- 47+ storage tanks (for storage of 1153600 steam produced from 1 cycle of system with 8 nuclear reactors)
and then as much steam turbines as one would want. You can use like 10 of them to get your required 58 MW and not missing that sweet nuclear energy efficiency at the same time, since your reactors in this case will only be active ~10% of the time. Just don't forget to give only 1 fuel cell to reactor at a time and disable inserters and heat exchangers to not waste any cells and temperature.

hoosh
Burner Inserter
Posts: 17
Joined: Tue May 17, 2016 7:49 pm
Contact:

### Re: 0.15 Reactor Ratio

DOSorDIE wrote:
Cobrikhan wrote:
werelord wrote:Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Same output potential as bulding
2 2 2 2
2 2 2 2
Its not
2 2 2 2
2 2 2 2

its
2 3 3 2
2 3 3 2

Just saying
I haven't had the chance to get to this point yet but couldnt you offset them by half and make it.....
3 4 4 2
2 4 4 3

This would be 6 units more effective with the same reactors.

inteljoe
Burner Inserter
Posts: 19
Joined: Wed Apr 20, 2016 9:04 pm
Contact:

### Re: 0.15 Reactor Ratio

1.21 GIGGAWATTS!!!

Koub
Global Moderator
Posts: 6447
Joined: Fri May 30, 2014 8:54 am
Contact:

### Re: 0.15 Reactor Ratio

inteljoe wrote:1.21 GIGGAWATTS!!!
Holly cow ! In French, it's 2.21 Gigowatts
Koub - Please consider English is not my native language.

Rhamphoryncus
Fast Inserter
Posts: 119
Joined: Tue Jul 14, 2015 10:57 pm
Contact:

### Re: 0.15 Reactor Ratio

FFS, I figured out why the turbines have that odd 5.8 MW rating. You can feed the heat exchangers with steam from boilers (1.8 MW each) and this simply adds to the 10 MW each heat exchanger normally outputs!

Total output is ~57.6 MW. Final ratio is 0.5:10:1:4:10.

hoosh
Burner Inserter
Posts: 17
Joined: Tue May 17, 2016 7:49 pm
Contact:

### Re: 0.15 Reactor Ratio

hoosh wrote:
DOSorDIE wrote:
Cobrikhan wrote:
werelord wrote:Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Same output potential as bulding
2 2 2 2
2 2 2 2
Its not
2 2 2 2
2 2 2 2

its
2 3 3 2
2 3 3 2

Just saying
I haven't had the chance to get to this point yet but couldnt you offset them by half and make it.....
3 4 4 2
2 4 4 3

This would be 6 units more effective with the same reactors.
Didnt format right. I meant it to look like this...

.3 4 4 2
2 4 4 3

MeduSalem
Smart Inserter
Posts: 1407
Joined: Sun Jun 08, 2014 8:13 pm
Contact:

### Re: 0.15 Reactor Ratio

Rhamphoryncus wrote:FFS, I figured out why the turbines have that odd 5.8 MW rating. You can feed the heat exchangers with steam from boilers (1.8 MW each) and this simply adds to the 10 MW each heat exchanger normally outputs!

Total output is ~57.6 MW. Final ratio is 0.5:10:1:4:10.
That works? o_O

Sounds like something I'll try.

Rage
Long Handed Inserter
Posts: 90
Joined: Sat Aug 09, 2014 2:08 am
Contact:

### Re: 0.15 Reactor Ratio

hoosh wrote:
hoosh wrote:
DOSorDIE wrote:
Cobrikhan wrote:
werelord wrote:Do reactors have to have dedicated heat pipe output lines I assume?? I'm thinking this sort of setup:

Same output potential as bulding
2 2 2 2
2 2 2 2
Its not
2 2 2 2
2 2 2 2

its
2 3 3 2
2 3 3 2

Just saying
I haven't had the chance to get to this point yet but couldnt you offset them by half and make it.....
3 4 4 2
2 4 4 3

This would be 6 units more effective with the same reactors.
Didnt format right. I meant it to look like this...

.3 4 4 2
2 4 4 3
That woun't work, you'll end up with
2 3 3 2
. 2 3 3 2
To get the bonus it has to be fully aligned, you can't off set.

MeduSalem
Smart Inserter
Posts: 1407
Joined: Sun Jun 08, 2014 8:13 pm
Contact:

### Re: 0.15 Reactor Ratio

Something must be wrong about the calculation in the first post of the thread... Or maybe I just didn't get it yet.

... because I'm able to output at least 217 MW out of 2 Reactors (with neighbour bonus). Maybe even more if I increase the amount of exchangers. Currently I have 24 connected and the 217 MW output and it remains stable as far as I have been checking here and then.

In the spreadsheet it says 159.3 MW maximum with 16 Exchangers.

Somehow I don't really get how the game internally determines how many Exchangers a single reactor can feed. Does every exchanger act as a drain for the heat generated and the heat dries to balance itself out flowing from the sources (reactors) to the drains (exchangers) using the heatpipes? I don't know.

Ah, I see the temperature at the reactors started to drop very slowly ever since I've connected 24 Exchangers... I guess it will continue to drop until it reached a sustainable amount of exchangers, which probably is the 16 as mentioned in the spreadsheet. The delay is just very long, which is why I thought it remained stable at 24.

[Edit 2]

When using Rhamphoryncus setup with using Boilers before the Exchangers then the power output may rise extremely... like by 80MW in my 2 Reactor Design... from 150-160 MW up to 230-240 MW.

That said the ratio is more likely:

Code: Select all

``Pump : Boiler : Reactor : Exchanger : Steam Turbine = 0.5 : 10 : 1 : 5 : 10``
While the 5th Exchanger might not be fully utilizied... like 75% or something... at least in my 2 Reactor design where I have 20 Exchangers there 2 of them aren't utilized because below 500°C.

I think if one is designing the layout in a smart way then there could be a short circuit from the Boilers to the Steam Turbines using a Pump that only works when you are out of Uranium Fuel Cells, basically abusing the Pre-Heating Boilers and Steam Turbines as an additional backup.

What I also noticed is that heat never spreads euqally even if the design is entirely symmetric in every direction. That makes it also hard to do some things... the Devs definitely need to improve the heatspread code because there seem to be some funky things going on.

After testing myself I still don't fully understand certain behaviour but well...

Pavgran
Burner Inserter
Posts: 11
Joined: Sat Apr 09, 2016 8:09 am
Contact:

### Re: 0.15 Reactor Ratio

Rhamphoryncus wrote:FFS, I figured out why the turbines have that odd 5.8 MW rating. You can feed the heat exchangers with steam from boilers (1.8 MW each) and this simply adds to the 10 MW each heat exchanger normally outputs!
The turbines have that odd 5.8 MW rating because it's actually 5.82 MW.

The math is as follows:
Steam turbines use 60 units of water per second (60u/s)
Each unit of water is heated to 500 Celsius degree (500 °C)
Each unit of water is heated from 15 Celsius degree (15 °C)
Water heat capacity is 0.2 kJ per unit per Celsius degree (0.2 kJ/u/°C)

So, final power output is:
60u/s*(500°C-15°C)*0.2 kJ/u/°C = 5820 kJ/s = 5.82 MW.

Regular steam engines output 900 kW just because water is heated to 165 °C and they use 30 units per second:
30u/s*(165°C-15°C)*0.2 kJ/u/°C = 900 kW

The heat exchanger to steam turbine ratio is 291:500