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Making liquid oxygen

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Neotuck    2319
3 minutes ago, dankusnher said:

Well, I put two aquatuners in a pool with pw, and the output was in 50ºC :/

they only drop 14 degrees each, automate them in a loop with some thermal sensors and liquid shutoffs 

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dankusnher    0
18 minutes ago, Neotuck said:

they only drop 14 degrees each, automate them in a loop with some thermal sensors and liquid shutoffs 

Thanks! I'll try to do something

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ZanthraSW    65
5 hours ago, onlineous said:

One of the problems with liquid methane is that the error margins are quite small. I've build polluted oxygen condensers in the past using an aquatuner and cooling the liquid oxygen at the bottom of the system. I couldn't get it to work safely in a closed loop so I needed an extra liquid pump (that was before the sensors on pipes were introduced though. Today it's easier to do).

Do you have an AETN you don't use? If you build your LOX producer around that I would suggest:

AETN (preferably with a heat exchanger, piping could break) --> output cold recapture --> closed loop hydrogen. In this system you have a lot of safety margin, the only thing affected by input temperature and input quantity is output quantity, you don't run the risk of freezing, breaking or otherwise damaging your system.

 

With Aquaturner cryo, I use a standing pool, a pump and an Aquatuner, all with Abyssalite insulated pipes. An open loop pump + aquatuner is 1440W for 10kg packets vs 240W for 1kg packets with closed loop thermoregulator. Remember you have a +3 and -3 degree swing between state changes, so Liquid methane will boil at -158.5 C and freeze at 185.6 which gives a decent 27.1 degree range, which is 13 degree safety margin, with a few hundred KG of methane in the pool, it's pleanty of thermal inertia. I do agree that it would be a nightmare without automation!

Here is a quick mockup of the idea. The more liquid methane the more stable the temperature, I would recommend at least 100KG per tile. Thermosensor pumps it to an aquatuner above -168, which gives 3.6 degrees of leeway after the Aquatuner as leeway in case an extra cold packet gets picked up by the pump (less likely with larger methane pool). The tempshift tiles in the methane tank cool a layer of hydrogen gas above to allow double the radiator size in the 2 tile height needed for the liquid pumps. The biggest issue I imagine with building this is the possibility of even Insulated Abyssalite tiles transfering heat to liquids near them if they are over their boiling temperature. Precooling the floor and wall tiles of the room before sealing it may be nescessary.

The methane precooling brings the input O2 down to at least -166C which leaves only 20 C to go before condensation. If you can manage to get the input gas to that temperature with a cold recapture system from the output, then the methane precooler won't do any good.

The LOX tank is held at -190 by another pump and aquaturner, and the tempshift tiles will liquify any incoming PO2. This is quite a bit larger than it needs to be in this design. The efficiency of Open Loop Aquatuned O2 vs Closed Loop Thermoregulated H2 is about 70 percent, so there is some efficiency to be gained there, but even with closed loop H2, I would recoomend the pool as a thermal buffer (with the H2 in radiant pipes behind the liquid) as it makes the temperature managment of the H2 loop easy by wiring a temosensor in the pool to the thermoregulator. The hydrosensor detects when the level rises and pumps some LOX into the room to the left. for evaporation.

The evaporator and cold recapture is the worst part of this, but the output gas is warmed to about -60 C, and input cooled to -120 C before entering the methane cooler. It needs to have more space for another pump, or be open air to let the system handle 1000g/s of PO2 cleaning, and because the radiant pipes in the evaporator and methane precooler can only handle 1000g/s, it does not scale much beyond that. Improvements would be to use high pressure gas and metal tiles to dump the heat in corridors near the evaporator and methane cooler and do away with the radiant piping.

The extra Thermosensor in each tank lead to the AND gate and gas shutoff which stops PO2 flow if the tank temps grow too high to prevent boiling.

Naturally the pool for the Aquatuners will have to have it's temperature managed by other means, but they only operate for short periods of time when the fluid pool temperatures rise above the limits.

LOX.jpg

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Carnis    122
2 hours ago, ZanthraSW said:

 

LOX.jpg

I like this.

If you encase those 2 aquatuner with mechdoor & Steam with correct presdurisation you could cool this using Po free pW boiling.

Assuming constant 1kg/s O2, could add an extra heat exchange between O2 gas leaving methane and cool methane coming from aquatuner. They could Be both on radiant pipes since incoming gas would be at highest -160, there would be no methane boiling risk. I imagine this would be more efficient with a small methane tank, could maybe Be tinkered to run rather frequently.

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ZanthraSW    65
28 minutes ago, Carnis said:

I like this.

If you encase those 2 aquatuner with mechdoor & Steam with correct presdurisation you could cool this using Po free pW boiling.

Assuming constant 1kg/s O2, could add an extra heat exchange between O2 gas leaving methane and cool methane coming from aquatuner. They could Be both on radiant pipes since incoming gas would be at highest -160, there would be no methane boiling risk. I imagine this would be more efficient with a small methane tank, could maybe Be tinkered to run rather frequently.

I was thinking about something along those lines as well, but I think a two stage methane cooler would be the right way to go.

The warm room has a thermosensor on a pump to send packets to the aquaturner at -168 C, and a hydrosensor at 100kg connected to a pump in the cold room. The cold room would have the pump to shunt the cold methane to the warm side to keep it's temp in range and maintain a good level, activated by hydrosensor in the warm room (activates when the warm methane is pumped away to the aquatuner.

The cold room has the outlet from the aquatuner, but is insulated from the warm side to keep the lower outlet temps of the methane. The PO2 passes from the warm side bringing it down to -166 C or so, then into the cold side, potentially cooling it another 10 degrees or so. This is at the cost of additional pumping, bringing the methane cooling loop to 1680W when active.

It avoids the issue of needing to maintain liquid in the pipes due to risks with tracking and managing in pipe temperatures. I much prefer to use pool based temperature sensors and management since they have much better thermal inertia.

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Carnis    122

I like simple builds. I would just precool the final room to -185 using hydrogen gas as the medium.

Then use your old build and old mechanics. Still an improvement of -10 -14 for the O2.

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ZanthraSW    65

Also, note the duty cycles for the aquatuners are too low to be useful directly in a PWater boiler (or if you do it would be a very slow boiler), but it can use a PWater feed tank for the boiler as a coolant, and any heat dumped there reduces the boiler's work. Additionally, be cautious of the length of the methane tank piping to the Aquatuner. Not only does long piping allow the methane level to get very low reducing the thermal inertia, but it also makes a longer delay between when the temperature sensor starts sending methane to be cooled and when it gets back to start lowering the temperature, so keep the methane tank as close to it's aquatuner as reasonably possible.

Or just use a lot more methane.

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Carnis    122
7 minutes ago, ZanthraSW said:

Also, note the duty cycles for the aquatuners are too low to be useful directly in a PWater boiler (or if you do it would be a very slow boiler), but it can use a PWater feed tank for the boiler as a coolant, and any heat dumped there reduces the boiler's work. Additionally, be cautious of the length of the methane tank piping to the Aquatuner. Not only does long piping allow the methane level to get very low reducing the thermal inertia, but it also makes a longer delay between when the temperature sensor starts sending methane to be cooled and when it gets back to start lowering the temperature, so keep the methane tank as close to it's aquatuner as reasonably possible.

Or just use a lot more methane.

Or prefill the methane liquidpipes, use a liquid shutoff as a trigger for the cooling cycle. Put the liquid shutoff on The cold hydrogen room. Then you always have cold methane waiting, so your piping doesnt need to Be that long Even If you add a coolroom. Costs 10kg methane per pipe, maybe extra 90kg would Be enough.

I do think it would Be a slow boiler. But it would Be maintenance free way to delete The heat. I add those boilers everywhere now.

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ZanthraSW    65

Yeah, I am just always wary of leaving cryofluids sitting in even insulated pipes, perhaps more than I should since abyssalite insulated piping seems to take so long to transfer heat, it would probably be thousands of cycles before it got to boiling point. Perhaps I will give the liquid shutoff on the cold side a try.

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onlineous    26
10 hours ago, Neotuck said:

This is why I use a hydro sensor to control the heat exchange 

When wet with oil/petroleum close the door to add heat from magma, when dry open the door

That definitely works in the vaporisation chamber (I do the same). I would however like to be able to heat up my heat exchanger chambers to just below the temperature where crude oil turns to petroleum to recapture more of the heat.

 

 

9 hours ago, dankusnher said:

It's possible to use this to cool water? If yes, how?

 

I actually would use an aquatuner only as last resort. If it's possible with wheezeworts or one or more AETN I would definitely go that way.

Another thing is to separate your (clean) water flows. Judging from the 70 degrees you're talking about I guess that water comes from a geyser. If you use the water from a water sieve you will get water from around 40 degrees. I tend to use the sieved (and quite cool) water to cool further down for my farms, whereas I use the hotter water in lavatories, showers and electrolyzers, all in which water temperature doesn't matter.

 

 

3 hours ago, ZanthraSW said:

Yeah, I am just always wary of leaving cryofluids sitting in even insulated pipes, perhaps more than I should since abyssalite insulated piping seems to take so long to transfer heat, it would probably be thousands of cycles before it got to boiling point. Perhaps I will give the liquid shutoff on the cold side a try.

I actually would go this way too. You do quite a lot of unnecessary pumping. The build indicated above by Carnis was really difficult to get working in previous build, without the gas pipe sensors, but today they can be done quite easily. I use that system in my LOX cooler as well. I could switch to cooling with liquid oxygen, but than I would include a heat exchanging chamber. I would be quite wary of putting supercooled liquids in radiant pipes, those systems tend to break without really tight control measures. Apart from that: I don't need cooling with supercooled liquid: as long as you have a good way of recapturing cold you don't need that much of cooling.

image.thumb.png.2f5bd1b6d12be183d2f5d05c4d51fa6a.png

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ZanthraSW    65

Yeah. Building heat exchangers between output and input in thermal system of ONI to recapture heat or cold, like PO2 cleaners, or PWater boilers is something I don't yet have a good feel or ideas for.

The image you posted there gives me some nice ideas for input/output heat exchangers, with the 13 temperature regions (regions strongly joined by overlapping tempshift tile influence areas), 11 buffered with PWater (or ice).

What input temperatures and output temperatures do you manage, and what is the temp of the last exchanger temperature zone (the one next to the LOX outlet for the evaporator)? Or if you could, if you count starting where the PO2 comes into the channel as 1, what's the temp of each region?

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dankusnher    0
3 hours ago, onlineous said:


Another thing is to separate your (clean) water flows. Judging from the 70 degrees you're talking about I guess that water comes from a geyser. If you use the water from a water sieve you will get water from around 40 degrees. I tend to use the sieved (and quite cool) water to cool further down for my farms, whereas I use the hotter water in lavatories, showers and electrolyzers, all in which water temperature doesn't matter.




 

For some time I used the water from sieve but now I doesn't have the pwr necessary to supply the farm, that's the problem. And I doesn't know how to use a aquatuner loop, like Neotuck suggested.

I'm with a food shortage because I don't have water to supply the farms but on the other hand I've 60t of clean water at 70ªC

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onlineous    26
2 minutes ago, dankusnher said:

For some time I used the water from sieve but now I doesn't have the pwr necessary to supply the farm, that's the problem. And I doesn't know how to use a aquatuner loop, like Neotuck suggested 

So actually the first thing you need to do is solve your power problem. Getting (a lot) more power early game to run an aquatuner tends to be difficult. I really would suggest you to look for wheezeworts or an AETN. Don't expand your base to fast, with 6-8 dupes you can already do quite a lot, especially if you start automating stuff as soon as possible. 

I prefer a petroleum tank with a contineous petroleum loop to cool down everything I need to cool in my base. This is the basic idea of such a loop.

image.thumb.png.b2f89ab33f9d822efdf83258143255e6.png

Ignore 1 and 2, those are the electrolizers and hydrogen pump system. 

4 is the petroleum tank, 3 a contineous petroleum loop (I run around 1 kg of petroleum per second through the pipes, but you could run whatever amount you like). The yellow loop is made from abbysalite insulated pipes, the part in the petroleum tank is made from tungsten radiant pipes. The green squares are made from granite (does transfer cold, but not too much so you don't loose all cold in the first few pipe sections).

Then you only have to worry about cooling the petroleum tank. I do that by making the bottom from tungsten tiles and with a room with wheezeworts supplied with enough hydrogen pressure to keep them running.

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dankusnher    0
20 minutes ago, onlineous said:

So actually the first thing you need to do is solve your power problem. Getting (a lot) more power early game to run an aquatuner tends to be difficult. I really would suggest you to look for wheezeworts or an AETN. Don't expand your base to fast, with 6-8 dupes you can already do quite a lot, especially if you start automating stuff as soon as possible. 

I prefer a petroleum tank with a contineous petroleum loop to cool down everything I need to cool in my base. This is the basic idea of such a loop.

image.thumb.png.b2f89ab33f9d822efdf83258143255e6.png

Ignore 1 and 2, those are the electrolizers and hydrogen pump system. 

4 is the petroleum tank, 3 a contineous petroleum loop (I run around 1 kg of petroleum per second through the pipes, but you could run whatever amount you like). The yellow loop is made from abbysalite insulated pipes, the part in the petroleum tank is made from tungsten radiant pipes. The green squares are made from granite (does transfer cold, but not too much so you don't loose all cold in the first few pipe sections).

Then you only have to worry about cooling the petroleum tank. I do that by making the bottom from tungsten tiles and with a room with wheezeworts supplied with enough hydrogen pressure to keep them running.

I'll try. The problem is that the cololy is on cycle 300 and i have 14 dups.

 

I think that I'll have to restart this colony. Actually, it's my record on colony life time and I learned a lot with this.

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onlineous    26
On 9-7-2018 at 3:28 PM, dankusnher said:

I'll try. The problem is that the cololy is on cycle 300 and i have 14 dups.

 

I think that I'll have to restart this colony. Actually, it's my record on colony life time and I learned a lot with this.

I would try to continue it. It would be a nice challenge!:)

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