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Post by bigbombr on Nov 13, 2016 21:54:45 GMT
 If you can have a reactor this small why bother with RTGs This thing has to be breaking physics somehow, right? Otherwise, I mean, Fallout-style nuclear cars would not be a problem. Forget cars, I'm thinking more along the lines of power armour and man-portable (anti-tank) railguns. This would make active defenses moot, as kinetic projectiles like said railguns are a lot harder to negate/disrupt than missiles. |
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Post by jonen on Nov 13, 2016 22:05:43 GMT
If you can have a reactor this small why bother with RTGs This thing has to be breaking physics somehow, right? Otherwise, I mean, Fallout-style nuclear cars would not be a problem. Keep in mind, the game uses the equations and don't have to bother with the actual plumbing to make it work. ... A one centimeter pump moving at 500 rpm, this thing isn't a snickers bar - it's a vibrator. |
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Post by Pttg on Nov 13, 2016 22:38:14 GMT
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Post by tessfield on Nov 13, 2016 22:51:53 GMT
Does anyone actually understand how different coolants interact with the reactors? Any thermocouple-based reactor have a hard limit based on the dimensions of the thermocouple. However, changing coolants internal coolant changes things dramatically. Using Hydrogen, for instance, you get horrible results vs. Sodium:
Sodium Coolant
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Hydrogen Coolant
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I don't quite understand why this happens? As far as I know, the temperature difference in the thermocouple is the only things that actually contributes to the voltage difference, yet when there's only a tiny difference in temperature (5°K) from changing the coolant, the actual power output changes dramatically. I'm assuming this has something to do with the thermal conductivity of each material ( 142W/m K on Sodium, 108mW/m K on Hydrogen), although this is not shown on the temperature graph. |
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Post by jonen on Nov 13, 2016 22:52:13 GMT
mmm. Probably not. This one vibrates rather less intensively, and runs rather hotter.
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Post by kaiserwilhelm on Nov 13, 2016 23:07:54 GMT
The reason the reactor runs at 500 rpm is so that it can be esentially smaller than a snickers.
On a side note why are there even RTGs in this game Iget that they have a longer livespan in real live but the game only models this kind of stuff for 6 monts dosent it.
So why implement RTGs when they are a lot hevier and a lot more expensive and have virtually no upsides
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Post by tessfield on Nov 13, 2016 23:38:44 GMT
While I haven't quite figured out why changing coolant changes everything so much, I think it has something to do with how much coolant passes through everything or something like that... Anyway, here's a Small As F**k (SAF) 1MW Open Sourced Reactor:
SAF 1 MW Mk.1
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Comparison with stock 1.04 MW Reactor
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I really wish we could have these kind of reactors mass produced and have everyone have one of these at home. Imagine a civilization which distributed power generation to every household through standarized nuclear reactors and fuel. I mean, would it change things much? Nope, other than move the economy away from centralized power generation companies to nuclear fuel pellet generation. Well, as long as they were safe. But that's usually why nuclear power for the masses is not a thing.  |
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Post by jonen on Nov 13, 2016 23:58:15 GMT
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Post by someusername6 on Nov 14, 2016 1:31:50 GMT
Thanks to khenderson and tessfield for the 1 MW reactors. Here's the version I am currently working with, from looking at yours -- both smaller radius and cheaper (though only razor thin safety margins):  |
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erin
Junior Member
Smash Mouth Plays From The Depths Of Hell As You Traverse A Deep, Rat-Infested Cave
Posts: 57 
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Post by erin on Nov 14, 2016 5:37:33 GMT
This thing has to be breaking physics somehow, right? Otherwise, I mean, Fallout-style nuclear cars would not be a problem. Keep in mind, the game uses the equations and don't have to bother with the actual plumbing to make it work. ... A one centimeter pump moving at 500 rpm, this thing isn't a snickers bar - it's a vibrator. Also most if not all of these micro-reactor designs (at least the ones I've seen) are using weapons-grade enriched nuclear fuel. That'd... probably keep these things from taking off even if they are viable IRL. |
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Post by n2maniac on Nov 14, 2016 6:59:09 GMT
Does anyone actually understand how different coolants interact with the reactors? Any thermocouple-based reactor have a hard limit based on the dimensions of the thermocouple. However, changing coolants internal coolant changes things dramatically. Using Hydrogen, for instance, you get horrible results vs. Sodium:
Sodium Coolant
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Hydrogen Coolant
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I don't quite understand why this happens? As far as I know, the temperature difference in the thermocouple is the only things that actually contributes to the voltage difference, yet when there's only a tiny difference in temperature (5°K) from changing the coolant, the actual power output changes dramatically. I'm assuming this has something to do with the thermal conductivity of each material ( 142W/m K on Sodium, 108mW/m K on Hydrogen), although this is not shown on the temperature graph. Sodium allows substantially greater heat fluxes through the same thermocouple area, which increases the current it can drive. This normally only comes up on efficient thermopiles or thermoelectric generators (such as what the game ends up simulating). The higher thermal conductivity of the fluid makes sodium a substantially better option. If you are curious to read more, look up the equations for heat transfer for a fluid under forced convection (this could easily take up a whole afternoon). A few starting points online: Heat transfer coefficientNusselt number
There is also a dependence on the flow rate achievable for the fluid, which depends on its viscosity, density, how much power you are willing to dump into the turbopumps, and (eventually) its speed of sound (though rarely is that a good regime to be hitting in standard heat transfer contexts). Hydrogen's 3 orders of magnitude lower thermal conductivity is somewhat offset by this, but sodium still wins out. |
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Post by n2maniac on Nov 14, 2016 7:26:58 GMT
While I haven't quite figured out why changing coolant changes everything so much, I think it has something to do with how much coolant passes through everything or something like that... Anyway, here's a Small As F**k (SAF) 1MW Open Sourced Reactor:
SAF 1 MW Mk.1
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Comparison with stock 1.04 MW Reactor
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I really wish we could have these kind of reactors mass produced and have everyone have one of these at home. Imagine a civilization which distributed power generation to every household through standarized nuclear reactors and fuel. I mean, would it change things much? Nope, other than move the economy away from centralized power generation companies to nuclear fuel pellet generation. Well, as long as they were safe. But that's usually why nuclear power for the masses is not a thing. Also, don't be shy on increasing the coolant pump power. I am dumping almost 10% of the electrical output into the inner pump. I am about 90% sure this thing has real-life practicality problems from both running everything up to its limit and the stability of the reactor, but it passes here:  |
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Post by n2maniac on Nov 14, 2016 7:41:46 GMT
If you can have a reactor this small why bother with RTGs Huh, TIL ethane in-game is a good coolant due to an absurdly high thermal conductivity (18W/mK vs comparable fluids in the 1 - 0.1 W/mK range). That should be a bug. In the meantime, I'll tuck that away. |
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Post by kaiserwilhelm on Nov 14, 2016 14:29:11 GMT
So I managed to make a semi efficent RTG and for the same power produced it stil cost double the cost of the snickers reactor alttough the RTG is a bit smaller  |
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Post by wafflestoo on Nov 14, 2016 16:13:01 GMT
So I managed to make a semi efficent RTG and for the same power produced it stil cost double the cost of the snickers reactor alttough the RTG is a bit smaller Ughh... that outlet temperature though. Just out of curiosity, how many m^2 of radiators does it need? In game, the only advantage that an RTG really offers over TEF is it doesn't require additional crew to operate (and there are mass savings to be had with that, at the expense of credits). In reality, it should also be several orders of magnitude more reliable and potentially longer-lived (factors that don't show up in game, when I use them it's usually for RP reasons). To be honest, sometimes I wish the 6-month life-limit were an enforced (and displayed) metric because I know of at least three campaign missions that would screw with that if you're designing right to the razor's edge (guilty as charged). |
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