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[1.12.x] Kerbal Atomics: fancy nuclear engines! (January 22, 2022)


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On 12/4/2021 at 6:58 PM, EnderiumSmith said:

An issue with the trimodal engines is that the electricity generation mode consumes fuel just as fast as running the engine at minimum throttle. This rate is much higher than normal reactors making them useless for actually providing power as leaving the engine on will quickly deplete the fuel. Also the engines have radiators in the part model so they should not make waste heat.

That's how that type of engine works - effectively, you *are* running it at minimum throttle. It's higher than normal reactors, but it means you don't have to have a separate reactor for electrical generation. How much worse is it?

Re: radiators in the model - when a trimodal nuke runs, most of the heat leaves the spacecraft in the exhaust - the radiators are to deal with heat that is transferred to the frame before the propellant leaves the engine. When operating in power production mode, the "propellant" stays in the engine and isn't exhausted, so it's plausible to have heat generation in that mode.

The intent of the RL trimodal engines is to operate in power production mode long enough to charge batteries or some other energy storage device, then to be shut down until needed for the next recharge. Of course, no one has built the real thing yet, so all the numbers are approximations anyway.

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4 hours ago, panarchist said:

That's how that type of engine works - effectively, you *are* running it at minimum throttle. It's higher than normal reactors, but it means you don't have to have a separate reactor for electrical generation. How much worse is it?

Re: radiators in the model - when a trimodal nuke runs, most of the heat leaves the spacecraft in the exhaust - the radiators are to deal with heat that is transferred to the frame before the propellant leaves the engine. When operating in power production mode, the "propellant" stays in the engine and isn't exhausted, so it's plausible to have heat generation in that mode.

The intent of the RL trimodal engines is to operate in power production mode long enough to charge batteries or some other energy storage device, then to be shut down until needed for the next recharge. Of course, no one has built the real thing yet, so all the numbers are approximations anyway.

The nuclear engines consume uranium at a much faster rate than the reactors. a nerv generates 500MW of power vs 400kW for the garnet. The trimodal mode of the triton only makes 20kW. thats a loooot less than 2% of 500MW. 

The radiators are for the generator. The nerv and stubber dont have them.

From what ive seen the engine would be kept warm in trimodal mode for the entire mission as that also reduces thermal cycling. there are no transient loads that happen close to burns so theres noting to power it it doesnt run the entire time.

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21 hours ago, EnderiumSmith said:

The nuclear engines consume uranium at a much faster rate than the reactors. a nerv generates 500MW of power vs 400kW for the garnet. The trimodal mode of the triton only makes 20kW. thats a loooot less than 2% of 500MW. 

The radiators are for the generator. The nerv and stubber dont have them.

From what ive seen the engine would be kept warm in trimodal mode for the entire mission as that also reduces thermal cycling. there are no transient loads that happen close to burns so theres noting to power it it doesnt run the entire time.

When you say "Triton", you mean "Neptune", right? (Triton is the RL design and isn't in Kerbal Atomics) That sounds in the right ballpark, given the details on Triton. The generator takes 3% of the output of the reactor in propulsive mode. Also, the MW in the engine is MWt (Thermal) - for the Triton design, 10% of the MWt becomes MWe (Electrical) - so the Brayton cycle generator is only going to produce 3 tenths of a percent of that - 500MWt becomes 1.5MWe.

The devil's in the details - without knowing how closely to the designs Nertea is modelling, and without more detail on the RL Triton, it's hard to say what's realistic - but I find it plausible that a Trimodal engine is less efficient than a fission reactor dedicated solely to electrical power. You gave the production numbers, but what's the consumption difference look like?

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34 minutes ago, panarchist said:

When you say "Triton", you mean "Neptune", right? (Triton is the RL design and isn't in Kerbal Atomics) That sounds in the right ballpark, given the details on Triton. The generator takes 3% of the output of the reactor in propulsive mode. Also, the MW in the engine is MWt (Thermal) - for the Triton design, 10% of the MWt becomes MWe (Electrical) - so the Brayton cycle generator is only going to produce 3 tenths of a percent of that - 500MWt becomes 1.5MWe.

The devil's in the details - without knowing how closely to the designs Nertea is modelling, and without more detail on the RL Triton, it's hard to say what's realistic - but I find it plausible that a Trimodal engine is less efficient than a fission reactor dedicated solely to electrical power. You gave the production numbers, but what's the consumption difference look like?

yes i mean the Neptune. The 500MW is the kinetic power of the actual nerv. Thermal would be higher. and Neptune is slightly bigger.

I had to reduce the consumption by 17.5 times to get the same lifetime at the same thermal power and uranium load as the kerbopower. The Neptune is 20% efficient vs 28% for the kerbopower so you get 20kWe at 100Wt vs 60kWe at 210kWt. Garnet is 33% and the FLAT is 50%.

Edited by EnderiumSmith
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  • 4 weeks later...
On 12/7/2021 at 2:55 PM, EnderiumSmith said:

yes i mean the Neptune. The 500MW is the kinetic power of the actual nerv. Thermal would be higher. and Neptune is slightly bigger.

I had to reduce the consumption by 17.5 times to get the same lifetime at the same thermal power and uranium load as the kerbopower. The Neptune is 20% efficient vs 28% for the kerbopower so you get 20kWe at 100Wt vs 60kWe at 210kWt. Garnet is 33% and the FLAT is 50%.

This is not a realism mod and trying to tune things based on jet power is going to fail miserably every time. Things are done for balance, not realism.

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  • 3 weeks later...
On 1/20/2022 at 4:30 PM, Davi SDF said:

I am sorry if i might be bothering, but Scylla's heat production (with system heat installed) is of 85kw, is this intentional? Or is it ten times too low?

I think that's right. NTR heat production is the 'excess' and a solid core NTR doesn't create a lot of excess. It is realted to the bit where the scylla has a power generation loop.

KA 1.3.3

  • Updated CryoTanks to 1.6.4
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  • 3 weeks later...

Coming back to KSP after some time off - has this mod changed recently or can anybody tell me what I'm missing? None of the atomic engines use enriched uranium, none of them have/use reactor controls and none of them produce any electricty. Is this a known issue?

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16 minutes ago, krautbernd12 said:

Coming back to KSP after some time off - has this mod changed recently or can anybody tell me what I'm missing? None of the atomic engines use enriched uranium, none of them have/use reactor controls and none of them produce any electricty. Is this a known issue?

It should be working.  Which versions of KSP and this mod do you have?  Have you got all of the dependencies installed?

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Newest version of KSP and newest version of the mod of course. The engines just act like normal engines, they don't integrate any of the reactor options and don't have any of the resources i.e. enriched uranium. I downloaded all of the near future mods&kerbal atomics from the github repository. Going through the configs for kerbal atomics the only engine actually listing enriched uranium is the Emancipator. Any help would be appreciated.

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2 hours ago, krautbernd12 said:

Newest version of KSP and newest version of the mod of course. The engines just act like normal engines, they don't integrate any of the reactor options and don't have any of the resources i.e. enriched uranium. I downloaded all of the near future mods&kerbal atomics from the github repository. Going through the configs for kerbal atomics the only engine actually listing enriched uranium is the Emancipator. Any help would be appreciated.

Make sure you have System Heat installed along with the optional patch that integrates NTRs from KA with SH. 

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This isn't about system heat, this is about none of the engines showing up or working as reactors, let alone having any of the associated resources. Is there any additonal patch or integration-thing I'm missing to get those engines working as reactors? Again, I just downloaded the mods from the linked github repositories. Near future electrical only includes "decaying RTGs" in the extras folder, and Kerbal Atomics only inlcudes "KerbalAtomicsLH2NTRModSupport" and "KerbalAtomicsNTRsUseLF". None of these make the engine work as reactors.  How do I get KA integrated with NFE?

Edited by krautbernd12
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2 hours ago, krautbernd12 said:

How do I get KA integrated with NFE?

NFE support have been removed from KerbalAtomics in version 1.3.0 of the mod:

NearFutureElectrical NTRs Extra has been removed forever

https://github.com/post-kerbin-mining-corporation/KerbalAtomics/releases/tag/1.3.0

 

You could:

1. use earlier version of the mod,

2. or just install SystemHeat and SystemHeatFissionEngines from SystemHeat/Extras.

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7 minutes ago, Judicator81 said:

NFE support have been removed from KerbalAtomics in version 1.3.0 of the mod:

NearFutureElectrical NTRs Extra has been removed forever

Thanks for the heads-up, I wasn't aware of that. I will have a look at system heat then .

Edited by krautbernd12
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15 hours ago, krautbernd12 said:

This isn't about system heat, this is about none of the engines showing up or working as reactors, let alone having any of the associated resources. Is there any additonal patch or integration-thing I'm missing to get those engines working as reactors?

Indeed, this is exactly what System Heat does when the relevant extra(s) are installed.

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This mod apparently lacks waterfall configs for the non-restock stock NERV, so I went into the files to try and modify the restock config to the stock NERV. It crashed my entire computer. I literally only changed the position of the effects. I think I've finally figured out what "eff around and find out" means.
(Not a complaint, just a funny/frustrating observation/warning)

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  • 2 months later...

so, does this mod require system heat now? and i saw that something from near future electrical was removed, but im not clear on what near future electrical ntrs is since theres nothing i can see in the near future electrical mod that might match the contraction ntr. that stuff about having to warm up and cool down and manage propellant and reactor somethings sounds like way too much when i already get overwhelmed trying to make rockets that work

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  • 3 months later...

Is it me, or Neptune engine is just not viable? It does have better thrust than NERV, but apparently requires a small moon-sized fuel tank filled with LN2 to just have a couple km/s of delta-V.

From the point of craft size its easier to have multiple NERVs than even one neptune.

Edited by Fallor
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5 hours ago, Fallor said:

Is it me, or Neptune engine is just not viable? It does have better thrust than NERV, but apparently requires a small moon-sized fuel tank filled with LN2 to just have a couple km/s of delta-V.

From the point of craft size its easier to have multiple NERVs than even one neptune.

While it's true LH2 takes up (a lot) more volume, you should try comparing the total stage mass with the LF NERV for the same total DV. The Hydrogen Neptune stage will be a lot lighter than the 500s isp LF NERV stage. (you can't really compare it to the stock config NERV using LF at 800isp, that's hydrogen range isp with the much denser rocket fuel, so it's quite overpowered)

If you want fuel volume efficiency the Neptune also has a LOX augmented mode, with even more thrust for lower 500ish isp. In that mode the LOX it uses means it's total fuel mass is denser allowing smaller stages.

And if you just prefer using LF like the stock NERV, there's also a patch available in the Extras folder to set the KA engines to use LF instead.

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11 hours ago, Rodger said:

While it's true LH2 takes up (a lot) more volume, you should try comparing the total stage mass with the LF NERV for the same total DV. The Hydrogen Neptune stage will be a lot lighter than the 500s isp LF NERV stage. (you can't really compare it to the stock config NERV using LF at 800isp, that's hydrogen range isp with the much denser rocket fuel, so it's quite overpowered)

If you want fuel volume efficiency the Neptune also has a LOX augmented mode, with even more thrust for lower 500ish isp. In that mode the LOX it uses means it's total fuel mass is denser allowing smaller stages.

And if you just prefer using LF like the stock NERV, there's also a patch available in the Extras folder to set the KA engines to use LF instead.

I went with flying LH2 moon option. Was quite a sight launching this thing in orbit, but it did give 10 km/s of delta/V in the end. Of course its also costs a ton in comparison.

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Though I just noticed possible dealbreaker issue with LH2. I assume natural background evaporation isn't a part of the mod.

It seems that on very fast warp speeds (waiting for transfer window kind) - electric charge starts to depleet faster than it accumulates. And I have over 70000 units in different batteries specifically testing the issue.

I put in small fission reactor generating additional 60ec/s. But it seems that on high warp ec consumption for cooling the tanks calculated wrong? Loosing half the tank waiting for transfer window is kinda not OK.

https://imgur.com/a/tjFbFJc

 

Update: Nevermind on that. I found multiple forum threads confirming that power generation/consumption in warp is stock KSP issue. Which is kinda strange for finished game.

 

Edited by Fallor
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13 hours ago, Fallor said:

Though I just noticed possible dealbreaker issue with LH2. I assume natural background evaporation isn't a part of the mod.

Boiloff is done by Cryo Tanks. (There's maybe two other mods that also do that like Real Fuels but it doesnt look like you have that installed. Don't remember what the other one is)

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