Pipeless Counterflow Liquid Heat Exchanger -- 90 kg/s Petroleum Boiler

[Zarquan]

I don't think anything in the game compares with the sheer asymptotic power of the flaking/boiling bug.  The heat energy in 36 kg of insulation at 500 C can boil about 5000 kg of water from 6.9 C to 100 C and still have some fuel to go on (being around 200 C).  I bet I can create a setup where a single aquatuner can power enough steam turbines to power an entire high level colony.  Granted, such a finely tuned machine would be tricky to actually create, but it is certainly doable.

[Zarquan]

As preliminary evidence, I present one aquatuner powering 7 turbines.  And the heat sink is getting hotter.  I need more turbines to keep this system cool.  And, while the boiling is happening, the aquatuner is producing more heat than the supercoolant can take, so the aquatuner spends some of its time offline.  I actually ran out of supercoolant in my boiler area, as I can't process the heat fast enough.

Don't mind the dev generator, it is just there to start the aquatuner.  The turbines are easily creating enough energy to power this.

The boiling medium in this example is chlorine at precisely 2547824.9 grams.  The smallest amount to the 1/10th of a gram that will boil 150 C supercoolant.

  The reason the mass has to be so high is that chlorine has an extremely low specific heat compared to supercoolants extremely high specific heat.

The aquatuner is submerged in around 10,000 kg/tile lead. 

I will make a new thread about this tomorrow (If nothing comes up).

[wachunga]

Has anyone figured out the exact math behind the flash boiling bug? Beyond the general sense of something is flipped somewhere.

I'm gathering data and will attempt to fit an equation to that data. But maybe it has already been done? Or perhaps partially done and I can build upon that?

[Zarquan]

As to the math, all I know is that is appears that high mass objects lose their heat very fast and low mass things lose their heat very slowly.  There also appears to be a hard cutoff point where the liquid can't boil anymore.  This can be easily identified if there is a large amount of the liquid and you ever see it touching the hot surface.  I may have also observed that the amount of heat lost increases with the starting temperature of the liquid, but I could be wrong about that.

[mathmanican]

2 hours ago, wachunga said:

Has anyone figured out the exact math behind the flash boiling bug?

@Zarquan's threads are the most detail I've seen on the forums.  I have no idea if discord has explored this fully, but I'm currently searching. PeterHan seems to have lots to say about "flaking" which is what he calls "boiling". 

 

27 minutes ago, Zarquan said:

There also appears to be a hard cutoff point where the liquid can't boil anymore.

At least one cutoff point is the liquid must be more than 3K below the vaporization point. Petro's vaporization point is 812K. If you place 809K petro on a tile that would have boiled, it won't. Drop the temp to 808.99, and it boils. 

[wachunga]

I think I got it.

I didn't explore the hard cutoff, just how much heat is lost from the donor cell to the flash boiled material. Or to rearrange things a bit, what the final temperature of a donor cell will be after it flash boils something.

When something is flash boiled, 5kg of it instantly jumps to 3C above it's boiling point (402.9C for petroleum). This is a bit different from regular boiling where the material loses 1.5C after it phase changes (410C crude changes to 408.5C petroleum).

 

Terminology:

FlashedSHC = Specific Heat Capacity of the material being flash boiled.

FlashedDelta = Difference in temperature between the flashed material's initial state and the post boiling state (including the extra 3C).

DonorSHC = Specific Heat Capacity of the cell that is causing the flash boiling.

DonorMass = Mass of that cell in kg.

DonorOldTemp = Temperature of that cell before it flash boils something.

 

Heat Lost From Donor Cell (kJ) = (10 * DonorSHC * DonorMass) - (5 * FlashedSHC * FlashedDelta)

Donor Cell's New Temperature = DonorOldTemp + ((5 * FlashedSHC * FlashedDelta) / (DonorSHC * DonorMass)) - 10

 

Note I only tested Insulation as the Donor and Crude as the Flashed. I suspect this is accurate for all materials, but I didn't check.

I have no idea how the math is actually implemented in the code. This is just an equation that accurately predicts what happens as far as my testing goes.

Please advise if your testing finds a case where this is not true.

[Zarquan]

I think I have an optimal design for a test chamber for this.  If you seal of the inlet and make everything 3 tiles thick, you can put such a large amount of supercoolant (like 1000000000 kg) and it will stay a constant temperature.  The airflow tile under the aquatuner can be filled with almost any gas or replaced with a solid natural tile of your choice. 

This setup (including the bead pump) allows the gas to be formed in one place and whisked away about as quickly as possible.  This is part of a functional setup.

I also have some hard numbers in this post, but I hadn't built this form yet.

Also, since the original build specifically attempts to avoid this bug, I am currently writing a new post about it.  I'll mention you in it.

 

[mathmanican]

1 hour ago, wachunga said:

I have no idea how the math is actually implemented in the code. This is just an equation that accurately predicts what happens as far as my testing goes.

It accurately predicts what I'm seeing too.  And it can be used to determine the cut off points (all my testing is with crude and abys.)

Basically, when you calculate Donor Cell's New Temperature, a check is made.  If the new temperature is less than the current temperature, the change is allowed to happen. Otherwise, no flaking occurs. 

I used to this find out exactly how large a tile of Abys. needs to be to boil 350K crude. If you set DonorCellsNewTemp = DonorCellsOldTemp, and then solve for DonorMass, you get the simple equation 

• DonorMass = FlashedSHC*FlashDelta/(2*DonorSHC).

With 350K crude, and the donor being abysallite at 700K, This means I need a mass of 68.876kg or greater to cause flaking/boiling/sweating to happen. Sure enough. 68.8 fails to flake, but 68.9 does. Oh, and the closer you are to this number, the more you can boil.  If you could keep a tile at exactly this number, and the flashed delta exact as well,  without it ever exchanging heat with the surroundings, I'm pretty sure you could it as an eternal heat source (though the flashed delta makes this kinda hard to achieve). 

Thanks @wachunga for the find. I'm pretty sure at this point we can easily design lots of contraptions, predict their behavior perfectly, and hopefully even help the devs find a feasible alternative. 

[Zarquan]

@wachunga@mathmanican, I don't suppose you would mind posting that math on the new thread I just created: 

I attached this thread to my original bug report.

 

[mathmanican]

3 minutes ago, Zarquan said:

I don't suppose you would mind posting that math on the new thread I just created:

I put in a link. I'll let @wachunga add the actual details to your other thread. I'll move the rest of my comments to that discussion, rather than this one about heat exchangers.  I'll probably also make a thread soon about my new heat exchanger, as otherwise I'll probably loose track of the post it in a few months. 

9 hours ago, Zarquan said:

The boiling medium in this example is chlorine at precisely 2547824.9 grams.  The smallest amount to the 1/10th of a gram that will boil 150 C supercoolant.

The formula I gave above seems to be pretty spot on. 

8.44* 286.85/0.48/2 = 2521.889583kg, or  2521889.583g. 

We can probably use your results to find what their error tolerance is. 

[Glassyfo]

On 4/18/2020 at 2:41 AM, Zarquan said:

Pros:

• Broken pipes can no longer happen, so significantly reduced maintenance requirements if something goes wrong.
• Minor errors in the liquid flows correct themselves.

By itself is already enough incentive for me to try it.