CoolRod - An Early Game Cooled Rodriguez SPOM

[psusi]

@Craigjw The SHC of the medium does not matter since it is maintaining a stable temperature at equilibrium.  What matters is how the heat is being conducted between the cold liquid pipe and the air duct.  You seem to be focused on the fact that the temperature of the heat exchanger is uniform.  That's nice, but that doesn't have anything to do with how long your radiant gas pipes need to be in order to get the oxygen cooled down enough.

[Craigjw]

And you just hit the nail on the head!

The only relevant information is the gas being cooled, the gas pipe material and length of gas pipe required to cool the gas, and not the medium, as this is negligible.

[psusi]

1 minute ago, Craigjw said:

And you just hit the nail on the head!

The only relevant information is the gas being cooled, the gas pipe material and length of gas pipe required to cool the gas, and not the medium, as this is negligible.

Only if radiant pipes ignore the medium TC the way insulated ones do.  If they still average the TC of the pipe with the TC of the tile, then the TC of the tile does matter.

[Craigjw]

8 minutes ago, psusi said:

Only if radiant pipes ignore the medium TC the way insulated ones do.  If they still average the TC of the pipe with the TC of the tile, then the TC of the tile does matter.

I would agree to some small percentage, and this percentage is negligible.

To be more precise:

(1/50)/100 is the agreeing percentage that I have with your statement.  I may have a gotten the maths wrong, but it's still negligible.

[psusi]

Just now, Craigjw said:

I would agree to some small percentage, and this percentage is negligible.

(1/50)/100 is the agreeing percentage that I have with your statement.

Why do you think it is negligible?  The TC of water is 0.609, and iron is 55.  That's a hell of a difference.  The TC of a copper radiant gas pipe is 9.  9 averaged with 55 is a hell of a lot higher than 9 averaged with 0.609.

[Craigjw]

That would be correct, if you were comparing 100kg of liquid vs 100kg of metal, but you aren't, there is 1000kg of liquid in a tile.

And what does multiplying the mass of water by it's TC give vs multiplying the mass of metal by it's TC?

When comparing, you should compare these two numbers, not the raw TC.

[Logiwonk]

1 hour ago, Fyrel said:

Using Ethanol liquid/vapour cooling in the steam turbine chamber would save you some cooling on the turbine and increase the overall efficiency. 

I've never used that before, are you suggesting dripping some ethanol on the steam turbine chamber and let it evaporate to cool the turbine?

[Craigjw]

I think it's something to do with the difference in TC of liquid and vapour ethanol, when it changes state it is thermally positive, ie, the ethanol increases temperature when it liquefies or vaporises, but I don't know which, it's just something I read a while ago.

[Fyrel]

58 minutes ago, Logiwonk said:

I've never used that before, are you suggesting dripping some ethanol on the steam turbine chamber and let it evaporate to cool the turbine?

You vacuum out the steam turbine chamber and empty a bottle or 2 of ethanol into the chamber.

Replace the roof with metal tiles and run the cooling pipe from your aquatuners through it then insulate it all in.

The liquid ethanol heats up with the aquatuner till it hits 81.4 C then flashes to gas.

The lower SHC gas fills the vacuum chamber hits the cold cooling bar at the top and instantly turns back to liquid.

You end up only heating the liquid and cooling the gas getting free cooling due to the difference in SHC.

[brucemo]

With aluminum it's easy to cool 3kg oxygen/second.

A room 3 wide by 4 high, that has three parallel radiant aluminum oxygen pipes moving from top to bottom, and a radiant aluminum pipe aquatuner cooled p-water zigzag going back and forth from bottom to top, and a hydrogen atmosphere, will cool oxygen by up to about 150 degrees C.

With the kind of temperatures you're going to see from that SPOM, even if you use 90 degree C water, you can cool the entire output to 10 degrees C with like 35% up-time on the aquatuner. You'd probably only need one aquatuner to cool both the oxygen and the turbine.

You could probably obtain similar results with other metals for pipes.

 

[psusi]

2 hours ago, Craigjw said:

That would be correct, if you were comparing 100kg of liquid vs 100kg of metal, but you aren't, there is 1000kg of liquid in a tile.

And what does multiplying the mass of water by it's TC give vs multiplying the mass of metal by it's TC?

When comparing, you should compare these two numbers, not the raw TC.

Except that TC for *gasses* is given dependent on mass, but liquids and solids are per meter, not per gram, so the mass of the liquid isn't supposed to matter.  Yet it does seem to work.

[Craigjw]

I call ********.

What you are saying is that 1g of liquid sitting on a tile will absorb the same amount of heat as a full tile of liquid, which is obviously wrong.

Total Thermal capacity of a tile is always Mass * Thermal Capacity.

[psusi]

15 minutes ago, Craigjw said:

I call ********.

What you are saying is that 1g of liquid sitting on a tile will absorb the same amount of heat as a full tile of liquid, which is obviously wrong.

Total Thermal capacity of a tile is always Mass * Thermal Capacity.

Capacity yes, but conductivity, at least according to the game, mass does not matter on liquids and solids.  Also even if the units are wrong, the mass of the water is only 5x the mass of the metal tile, yet the stated conductivity of the metal is far more than 5x higher than that of water, so it should still win.

 

Actually the wiki shows different units that don't involve mass for liquids and gasses, but I just checked the game and it shows the same units for both.  Still, multiplying the number for water by 5 still doesn't get it nearly as high as water.

[Logiwonk]

@Fyrel - Cool idea, will try that out. This design is meant for a Terra start early game build, but I will probably put the ethanol cooling in my Gucci CoolRod which will come next with all the bells and whistles.

 

[Craigjw]

The tile is more massive than the pipe, which in turn is a lot more massive than the gas going through it.  If you multiply the masses with Tcon & Tcap, then look at the ratio's between the gas vs pipe and then the pipe vs medium we find that the gas vs pipe has the biggest differential.  The bigger the differential, the more important Tcon matters, hence why I consider the type of medium as mostly negligible as it has a lower differential.

Basically, Gas/Pipe = 1/50 vs Pipe/Medium = 50/100.  And usually solids have about 10 times the Tcap than liquids, which is why I'm using 100 for the medium.

Another way to look at it is that, the bigger the ratio, the more work a single gram of material has to do in order to equalize the temperature difference and in this case, the work done is governed by it's Tcon.

[Logiwonk]

Updated original post with new testing results:

After 20+ cycles to reach thermal equilibrium, over a 300 sec period this thing puts out an average of 2.98 kg/sec O2 at average of 18.3 deg C

[psusi]

@Fyrel

Using ethanol to cool the turbine *reduces* your efficiency, not increases it.  You are deleting heat that could be generating power in the turbine.

[Fyrel]

4 hours ago, psusi said:

@Fyrel

Using ethanol to cool the turbine *reduces* your efficiency, not increases it.  You are deleting heat that could be generating power in the turbine.

The heat in the room with the steam turbine is always waste heat, your never generating power from it.

[psusi]

1 hour ago, Fyrel said:

The heat in the room with the steam turbine is always waste heat, your never generating power from it.

Nope... if you are cooling it using the water coming out of the turbine itself on the way back to the steam side, then that heat is captured and used for power.

 

Also I think I'm going to make one improvement to this design when I try to build it tonight: put a little recirculating loop in the vent that will only fill up when the vent is under back pressure, and use an element sensor to detect that and stop the oxygen pumps.  That way the back pressure won't cause the oxygen to sit in the heat exchanger longer and get colder.

[Logiwonk]

1 hour ago, psusi said:

Also I think I'm going to make one improvement to this design when I try to build it tonight: put a little recirculating loop in the vent that will only fill up when the vent is under back pressure, and use an element sensor to detect that and stop the oxygen pumps.  That way the back pressure won't cause the oxygen to sit in the heat exchanger longer and get colder.

Glad you're going to experiment with it! I've been messing around with replacing the metal tiles with pWater which seems like it will work but is probably going to take 5-10 cycles to get the water to goal temperature. On the upside it's been a great stress test to show the system remains power/H2 positive when running the AT at 100% uptime for prolonged periods.

I'm going into a 14 hr shift x 6 nights schedule for the next week so I won't have a lot of time to experiment, but will post additional designs when I make in them in the future.

Also was just reading the turbine heat deletion bug thread and looks like I'll have to modify the steam box in this thing to avoid that power loss.

[psusi]

1 hour ago, Logiwonk said:

I've been messing around with replacing the metal tiles with pWater which seems like it will work but is probably going to take 5-10 cycles to get the water to goal temperature.

I think you were right about the metal or water not mattering.  I'm going to try with just air and some stone stempshift plates.

1 hour ago, Logiwonk said:

Also was just reading the turbine heat deletion bug thread and looks like I'll have to modify the steam box in this thing to avoid that power loss.

Don't you just have to not put too much water in?

[KittenIsAGeek]

TC = Thermal Conductivity.
SHC = Specific Heat Capacity.

Please use the right acronyms.  

[biopon]

On 11/14/2019 at 3:06 PM, psusi said:

Yes, the radiant pipe doubles its own conductivity, but does it then use only that, or does it still average that with the TC of the tile it is in?

I hate to be the guy that says this, but... it's more complicated than that. It's not an average, they're multiplied together. And there's a constant. 

https://oxygennotincluded.gamepedia.com/Thermal_Conductivity

You want the cell-to-building formula if you're curious about pipes. 

But the short answer is: if you want the fastest heat exchange with gas, and can't afford space stuff, use steel pipes. They're the best, and unless you're trying to change the temperature of the gas by hundreds of degrees, a couple of sections is usually enough. Like @Craigjw said, the rest doesn't much matter.

On 11/14/2019 at 8:54 AM, Logiwonk said:

If you guys have some favorite builds for utilizing the waste heat from the refinery

Very simply: have a reservoir next to the refinery with coolant in it, and have a steam turbine above. Have the refinery's output go through 6-8 sections of alu pipe under the steam turbine. Use thermal buffering (dirt tempshift, igneous drywall, etc) under the turbine so you don't spike a few kilos of water way above 200C. Next have the coolant go to the reservoir. From the reservoir, have it go to the refinery's input. Depending on how many pipe sections you used for cooling, the coolant in the reservoir will, long term, average to a bit (or a fair bit) over what the steam temperature is. It doesn't really matter what that temperature is, provided the coolant exiting the refinery isn't anywhere close to boiling. Keep an eye on it, but this setup is as simple as it gets, and as long as you use enough alu pipe, enough thermal buffer, and have a reservoir fullish with petrol, it cannot go wrong.

If you want to be a bit fancier: use a thermo sensor in the steam so your turbine only turns on at 200C to maximize efficiency. If you do this, you'll probably have to find a way to cool the turbine itself. If instead you let it auto-regulate at 125C, it can probably self-cool with its own output.

[psusi]

11 hours ago, KittenIsAGeek said:

TC = Thermal Conductivity.
SHC = Specific Heat Capacity.

Please use the right acronyms.  

Who was that directed towards?

4 hours ago, biopon said:

If you want to be a bit fancier: use a thermo sensor in the steam so your turbine only turns on at 200C to maximize efficiency.

I just asked about this the other day in another thread and it seems that since they revamped the turbine, this no longer provides any benefit.

[KittenIsAGeek]

1 hour ago, psusi said:

Who was that directed towards?

There were many posts by many individuals where it wasn't clear if they were talking about the thermal conductivity or the heat capacity of a material.  It wasn't directed toward anyone specifically.  Instead, I was just reminding everyone of the acronyms and what they mean so that future posts would be more clearly understood.