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Post by caiaphas on Dec 30, 2016 17:49:11 GMT
jasonvance, do you know how it scales down to the 500 and 100kW range, or are RTGs more efficient at such low powers?
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Post by bigbombr on Dec 30, 2016 18:18:37 GMT
jasonvance , do you know how it scales down to the 500 and 100kW range, or are RTGs more efficient at such low powers? In this game, fission reactors are always cheaper than RTG's. RTG's only advantage is that they don't need crew. |
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Post by caiaphas on Dec 30, 2016 18:30:23 GMT
Are they always more mass-efficient too?
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Post by jasonvance on Dec 30, 2016 20:42:03 GMT
jasonvance , do you know how it scales down to the 500 and 100kW range, or are RTGs more efficient at such low powers? I have yet to find a real use for RTGs, even for really low power options like 10W fission reactors are more mass and cost effective. A few notes from building reactors: With enough fiddling you can get close to 10MW (60MW total heat) out of 100 grams of U-233 dioxide at 97% enrichment. So every value below that is going to be some lower enrichment value of 100 grams U-233 dioxide. To be min-maxed for cost the lowest possible enrichment value, with the highest possible neutron flux for that enrichment value will have to be found to generate enough heat to leech the amount of power you want. So if you want ~1MW at 2400K you need ~6.06MW waste heat. You calculate that by taking the power you want and dividing that by the max thermocoupler efficiency rating for your outlet (16.5% for 2400k so 1/.165 = ~6.06). Max sustainable Neutron Flux is a little more tricky so I just kind of eyeball it based off previous reactor results for neturon flux stability (avoiding the reactor burning through fuel too fast error is the real pain). After you get your reactor outputting the correct amount of waste heat you just need to make it not melt with turbopumps and a large enough thermocoupler. To be the highest efficiency possible you want it to be right on the brink of melt down, and thermocoupler yield str. If you find yourself more meltdown prone than yield str prone reduce the size of the thermocoupler (and vice versa). For the turbopumps simply inch the size of the turbopump up/down while tuning down/up the RPM (you will find an optimal size to RPM ratio for lowest mass or cost eventually). If you care about radiation (I usually don't but some people complain if it pumps out enough to sterilize the planet below). You can make your reactor really tall and skinny this will minimize the radiation leakage 1 cm x n cm **Note: I am still not confident 2400K outlet is optimal for cost but it is the most requested and probably not too far off (I know it isn't the most mass effective that is RCC 2272K outlet, but pretty much everyone dismisses that due to the high cost of RCC so I am messing around with cost opt atm)** |
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Post by caiaphas on Dec 31, 2016 6:34:26 GMT
jasonvance , do you know how it scales down to the 500 and 100kW range, or are RTGs more efficient at such low powers? I have yet to find a real use for RTGs, even for really low power options like 10W fission reactors are more mass and cost effective. A few notes from building reactors: With enough fiddling you can get close to 10MW (60MW total heat) out of 100 grams of U-233 dioxide at 97% enrichment. So every value below that is going to be some lower enrichment value of 100 grams U-233 dioxide. To be min-maxed for cost the lowest possible enrichment value, with the highest possible neutron flux for that enrichment value will have to be found to generate enough heat to leech the amount of power you want. So if you want ~1MW at 2400K you need ~6.06MW waste heat. You calculate that by taking the power you want and dividing that by the max thermocoupler efficiency rating for your outlet (16.5% for 2400k so 1/.165 = ~6.06). Max sustainable Neutron Flux is a little more tricky so I just kind of eyeball it based off previous reactor results for neturon flux stability (avoiding the reactor burning through fuel too fast error is the real pain). After you get your reactor outputting the correct amount of waste heat you just need to make it not melt with turbopumps and a large enough thermocoupler. To be the highest efficiency possible you want it to be right on the brink of melt down, and thermocoupler yield str. If you find yourself more meltdown prone than yield str prone reduce the size of the thermocoupler (and vice versa). For the turbopumps simply inch the size of the turbopump up/down while tuning down/up the RPM (you will find an optimal size to RPM ratio for lowest mass or cost eventually). If you care about radiation (I usually don't but some people complain if it pumps out enough to sterilize the planet below). You can make your reactor really tall and skinny this will minimize the radiation leakage 1 cm x n cm **Note: I am still not confident 2400K outlet is optimal for cost but it is the most requested and probably not too far off (I know it isn't the most mass effective that is RCC 2272K outlet, but pretty much everyone dismisses that due to the high cost of RCC so I am messing around with cost opt atm)** This is excellent, thank you. On a tangent, does anyone know how old those links for the nukes are (I was trying some of them earlier and couldn't get them to work)? If anyone's interested, I've hashed together a line of nukes from the 1 kt to 10.2 Mt range that I hope are size- and mass-optimized. |
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Post by David367th on Dec 31, 2016 7:13:56 GMT
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Post by caiaphas on Dec 31, 2016 7:31:20 GMT
...hang on, please. Right, so I screwed up an order of magnitude entry, which is why the damn things weren't working. Thanks! |
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Post by jasonvance on Dec 31, 2016 9:06:57 GMT
This is excellent, thank you. On a tangent, does anyone know how old those links for the nukes are (I was trying some of them earlier and couldn't get them to work)? If anyone's interested, I've hashed together a line of nukes from the 1 kt to 10.2 Mt range that I hope are size- and mass-optimized. Just note that my nukes were cost optimized not size / mass so they might not be quite what you are looking for (especially if you are trying to fire them from a coilgun). If you want something that is close to smallest, cheapest, and lowest mass I would recommend my 1.33Mt nuke design (as it is right in the nice fusion efficiency point of the nuke curve) It is 158 kg, 80.8kc with a 13cm radius x 52cm height (it is the nuke that I actually use for most of my missiles as it is more dense than the others with reasonably high yield ) You could make it a tad lighter with UHWMPE reflector or smaller with Osmium but the cost will go up. NuclearPayloadModule 1.33 Mt Boosted Fission Nuke
UsesCustomName false
CoreComposition U-233
ReflectorComposition Boron
SlowExplosive
CombustionReaction Silicon Nanothermite
DelayComposition Potassium
DelayCompositionMassFraction 0.682
FastExplosive Nitrocellulose
CoreMass_kg 135
Enrichment_Percent 0.97
HollowCoreRadius_m 0.06726
InnerExplosiveWidth_m 0.001
FusionBoost Deuterium Tritium
FusionFuelDensity_kg__m3 3804
Detonator
HardRange_km 0.01
ActivationRange_km 100
MinimumRange_km 1
OverrideTimer_s 0
TargetsShips true
TargetsShots false |
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Post by caiaphas on Dec 31, 2016 9:26:23 GMT
This is excellent, thank you. On a tangent, does anyone know how old those links for the nukes are (I was trying some of them earlier and couldn't get them to work)? If anyone's interested, I've hashed together a line of nukes from the 1 kt to 10.2 Mt range that I hope are size- and mass-optimized. Just note that my nukes were cost optimized not size / mass so they might not be quite what you are looking for (especially if you are trying to fire them from a coilgun). If you want something that is close to smallest, cheapest, and lowest mass I would recommend my 1.33Mt nuke design (as it is right in the nice fusion efficiency point of the nuke curve) It is 158 kg, 80.8kc with a 13cm radius x 52cm height (it is the nuke that I actually use for most of my missiles as it is more dense than the others with reasonably high yield ) You could make it a tad lighter with UHWMPE reflector or smaller with Osmium but the cost will go up. NuclearPayloadModule 1.33 Mt Boosted Fission Nuke
UsesCustomName false
CoreComposition U-233
ReflectorComposition Boron
SlowExplosive
CombustionReaction Silicon Nanothermite
DelayComposition Potassium
DelayCompositionMassFraction 0.682
FastExplosive Nitrocellulose
CoreMass_kg 135
Enrichment_Percent 0.97
HollowCoreRadius_m 0.06726
InnerExplosiveWidth_m 0.001
FusionBoost Deuterium Tritium
FusionFuelDensity_kg__m3 3804
Detonator
HardRange_km 0.01
ActivationRange_km 100
MinimumRange_km 1
OverrideTimer_s 0
TargetsShips true
TargetsShots falseYeah, taking a look at them, mine are around two to three times heavier and more expensive than yours on average, but mine are around, let's say 20% skinnier? They'd definitely help my bottom line if I could build a missile and coilgun capable of firing them, I'm working on that right now. Thanks for the help! EDIT: especially since I just field-tested my 1 kt version against a quartet of stock gunships and while it took around a dozen warheads to disable the squadron, it took around twenty times that to mission-kill all of them, so definitely going to need to make these cheaper somehow. |
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Post by jasonvance on Dec 31, 2016 9:42:06 GMT
Yeah, taking a look at them, mine are around two to three times heavier and more expensive than yours on average, but mine are around, let's say 20% skinnier? They'd definitely help my bottom line if I could build a missile and coilgun capable of firing them, I'm working on that right now. Thanks for the help! EDIT: especially since I just field-tested my 1 kt version against a quartet of stock gunships and while it took around a dozen warheads to disable the squadron, it took around twenty times that to mission-kill all of them, so definitely going to need to make these cheaper somehow. Yeah price was the big killer for use on nukes which was why I made those cost optimized boron reflector nukes. If you are looking for something to fire out of a coilgun some people have had luck with the 95t nukes. You can make them even smaller with Osmium again but I tend to think cost is the main limiting factor to nukes.  HollowCoreRadius_m 0.03504 FusionFuelDensity_kg__m3 20.09 |
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Post by caiaphas on Dec 31, 2016 9:53:44 GMT
Yeah, off the top of my head, osmium is what I've been using for the smaller ones, switching to boron for my 100 kt and 1 and 10 Mt variants.
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Post by tessfield on Dec 31, 2016 20:00:43 GMT
Okay, time to update this!
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Post by tessfield on Dec 31, 2016 20:24:36 GMT
Hiya ash19256! Added the reactors you optimized from Apophys. I'm considering starting calling reactors by its latest author, and just keep a list of the people who modified it in the author column, but I'll change that once I finish updating all this. |
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Post by tessfield on Dec 31, 2016 20:43:42 GMT
Thank you @jsonvance for the best radiator material best on temperature table! Added!
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Post by tessfield on Dec 31, 2016 20:56:24 GMT
Hiya zorbeltuss! Welcome to the forums! Added your 95t nuke optimization |
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