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Post by Apotheon on Sept 15, 2018 20:02:33 GMT
Can someone share a 10 kW RTG? I'm currently using 3 of the stock RTG's for my 10 kW needs, so anything more cost/mass optimised than that solution would be great stuff.
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Post by AtomHeartDragon on Sept 15, 2018 20:15:33 GMT
My RTGs are anything but cost optimized, but the are smallish, not too cold, and can sit flush with CMs.
I only have 20kW, not 10kW, though:
RadioisotopeThermoelectricGeneratorModule _DCA 20.0 kW Radioisotope Thermoelectric Generator
UsesCustomName true
FuelPellet
Fuel Curium-242
Mass_kg 0.74
Height_m 0.22
Thermocouple
PTypeComposition Nickel Chromium Iron
NTypeComposition Pyrolytic Carbon
Length_m 0.029
ExitTemperature_K 520
Coolant Sodium Potassium
Turbopump
Composition Austenitic Stainless Steel
PumpRadius_m 0.002
RotationalSpeed_RPM 860
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Post by Apotheon on Sept 17, 2018 17:08:11 GMT
My RTGs are anything but cost optimized, but the are smallish, not too cold, and can sit flush with CMs. I only have 20kW, not 10kW, though: RadioisotopeThermoelectricGeneratorModule _DCA 20.0 kW Radioisotope Thermoelectric Generator
UsesCustomName true
FuelPellet
Fuel Curium-242
Mass_kg 0.74
Height_m 0.22
Thermocouple
PTypeComposition Nickel Chromium Iron
NTypeComposition Pyrolytic Carbon
Length_m 0.029
ExitTemperature_K 520
Coolant Sodium Potassium
Turbopump
Composition Austenitic Stainless Steel
PumpRadius_m 0.002
RotationalSpeed_RPM 860Thanks! This allows me to verify that I can make one of my ships 112 tons with 40 tons of propellant instead of 113 tons with 40.16 tons of propellant, the cost 20% less, and that my big radiators don't belong so I shouldn't get attached to them. |
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Post by AtomHeartDragon on Sept 17, 2018 17:32:19 GMT
My RTGs are anything but cost optimized, but the are smallish, not too cold, and can sit flush with CMs. I only have 20kW, not 10kW, though: RadioisotopeThermoelectricGeneratorModule _DCA 20.0 kW Radioisotope Thermoelectric Generator
UsesCustomName true
FuelPellet
Fuel Curium-242
Mass_kg 0.74
Height_m 0.22
Thermocouple
PTypeComposition Nickel Chromium Iron
NTypeComposition Pyrolytic Carbon
Length_m 0.029
ExitTemperature_K 520
Coolant Sodium Potassium
Turbopump
Composition Austenitic Stainless Steel
PumpRadius_m 0.002
RotationalSpeed_RPM 860Thanks! This allows me to verify that I can make one of my ships 112 tons with 40 tons of propellant instead of 113 tons with 40.16 tons of propellant, the cost 20% less, and that my big radiators don't belong so I shouldn't get attached to them. You don't need my RTGs to detach you from your big radiators, intense sandblaster fire is usually enough. |
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Post by Apotheon on Sept 17, 2018 22:32:28 GMT
Hah... oh and by the way Satan called and my rocket's not gonna fly unless the RTG (7.35 kW output) + radiators are <2.4 2.5 kg in mass  So there's a challenge... |
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Post by someusername6 on Sept 20, 2018 13:35:04 GMT
Here's a pass at it, with mass 1.61 kg (one RTG, two radiators).
RadiatorModule 0.8x0.10 Reinforced Carbon-Carbon Radiator
UsesCustomName false
Composition Reinforced Carbon-Carbon
PanelWidth_m 0.1
Height_m 0.1
Thickness_m 0.001
ArmorThickness_m 0.001
Panels 8
FrontTaper_radians 0
BackTaper_radians 0
SurfaceFinish null
RadioisotopeThermoelectricGeneratorModule 7.42 kW Radioisotope Thermoelectric Generator
UsesCustomName false
FuelPellet
Fuel Curium-242
Mass_kg 0.61
Height_m 0.43
Thermocouple
PTypeComposition Nickel Chromium Iron
NTypeComposition Gadolinium
Length_m 0.0027
ExitTemperature_K 1175
Coolant Hydrogen
Turbopump
Composition Polyethylene
PumpRadius_m 0.028
RotationalSpeed_RPM 73
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Post by Apotheon on Sept 20, 2018 14:34:29 GMT
My efficiency is 30% and the stock is 50%, so I guess there's room for improvement.
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Post by AtomHeartDragon on Sept 20, 2018 14:53:33 GMT
My efficiency is 30% and the stock is 50%, so I guess there's room for improvement. You can get better efficiency with cooler radiators, but of course this also means waaaayyyy bigger radiators - for given a mount of waste heat they scale with -4th power of temperature.
If you want small, you'll have to deal with inefficient.
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Post by Apotheon on Sept 20, 2018 15:35:39 GMT
My efficiency is 30% and the stock is 50%, so I guess there's room for improvement. You can get better efficiency with cooler radiators, but of course this also means waaaayyyy bigger radiators - for given a mount of waste heat they scale with -4th power of temperature.
If you want small, you'll have to deal with inefficient.
Edit: after a lot of experimentation, I got down to under only 1.6 kg, but decided to go up again to just under 2.5 kg, 18.8 kc, and 7.36 kW with 40% efficiency at 800 K. I went with your material choices, except lithium turbopump and ethane coolant. I feel I understand most of the optimisation, except the P/N-type materials, which are quite counter-intuitive.
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Post by tepidbread on Sept 20, 2018 21:56:21 GMT
I don't build RTGs... So here is my entry with a small 40kW reactor. It is .01 kg over the limit with my poorly optimized radiator but produces 40kW. At 2700K it is super easy to cool it. I just hacked this together in a few minutes and it could certainly be made lighter. ![]() |
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Post by someusername6 on Sept 21, 2018 4:25:05 GMT
Reactors have crew requirements though -- RTGs don't.
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Post by tepidbread on Sept 21, 2018 14:08:36 GMT
Reactors have crew requirements though -- RTGs don't. I did not think about that. Somehow I am still able to build drones with them though. Is that a bug? |
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Post by someusername6 on Sept 21, 2018 15:28:10 GMT
Reactors have crew requirements though -- RTGs don't. I did not think about that. Somehow I am still able to build drones with them though. Is that a bug? No -- this just transfers the crew requirement to whichever module launches the drone. I bring this up because I've only seen people interested in RTGs recently when they are trying to minimize the mass of a crewed ship (or have a backup power system). In most other situations, yes, you should just use a reactor instead. |
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So there's a challenge...
