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Specific Heat, Electrolizers, and Costs to cool


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I will start this conversation with "I am not a physicist, but I play one on TV".  I know the basics, and *think* I know what I'm talking about.  With that in mind, if one of the more conversant folks would be willing to double check my logic on this, that'd be appreciated.

The conversations starts with building an electrolizer rig in one of my typical builds, using two electrolizers in a typical Hydrogen/Oxygen cage to make sure they separate themselves.  Then the questions get interesting as I'm trying different techniques to get the heating problems in my base under control.  I know you can stick them into anti-entropy and cold biomes, but I want to try to enforce cooling them directly in the middle of my base.

So, I've built myself a happy little coolant room filled with cooled Hydrogen, cooled water, or other combinations in different techniques and I'm just not getting the amount of cooling I keep expecting to get, so I decided to sit down with the math.

So, basic problem is I'm trying to get 70C O2/H2 down to (for roundish numbers) a 25C result.  Ends up with a 45C delta change.

Specific Heat of O2 is 1.005 J/g/K, so I should require 45.225 j/g

Specific Heat of H is 2.4 J/g/K, so that would require 108 J/g

For a single electrolizer (for a second), those figures come out to:

  • 888 g O2 |  40,159.8 J
  • 112 g H   |  12,096 J
  • Total: 52,255 J

For two electrolizers, that means I'd be needing 104,510 W (J/s) to upkeep the heat removal of two full time (I know, they don't, but let's keep it semi-simple) electrolizers sharing a heat removal technique (Tempshift Plates in this case).

Trying a few techniques including wheezeworts and Temperature Regulators, I've found I just don't really have the throughput for cooling that I'd thought, and want to figure out if I've at least got the premise right for the heat to energy calculations before I (enjoyably) bang my head on my other mistakes. 

For those interested, one build I trashed was due to not cooling down the ducts in the ventilation first and not wanting to wait for them to stabilize.  It's been a mishmash of different things.  I should mention that I'm NOT in the preview build, though it shouldn't matter for this conversation.

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image.thumb.png.32cbd73ff9c84522e39ec0496a5326c0.png

 

Right now we are running a bit hot with 4 full time electrolyzers  to 4 wheezeworts in hydrogen/granite.

But I added a liquid oxygen vent throwing around 50kg of -192 degrees direct on the pipes and got the output to around 25-28 degrees.

In the picture above the polluted O2 vent providing liquid oxygen is dormant, so.. we have no coolant right now :-).

But snaking the pipes through hydrogen wheezeworts is a good start, the wheeze also cool the pipes when there is no gas in them, so they pre-cool sort of.

Also, you don't really need to cool the hydrogen, just run it inside an insulated room into the generators. They settle at 70 degrees and require no outside coolant.

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32 minutes ago, Carnis said:

Right now we are running a bit hot with 4 full time electrolyzers  to 4 wheezeworts in hydrogen/granite.

But I added a liquid oxygen vent throwing around 50kg of -192 degrees direct on the pipes and got the output to around 25-28 degrees.

Thanks, but can you explain to me how that confirms (or denies) my understanding of specific heat and cooling costs? 

I have favorite techniques that *do* work for base cooling, including LOX.  I'm trying to get into the nitty gritty of exactly why certain things do and don't work, and that all begins with the discussion of "How Much Cooling do you need, exactly?", which is measured in Watts.  Telling me to pour LOX onto the problem doesn't help me understand the exact mechanics.

Perhaps I need to be more explicit:

For example: A Thermo Regulator provides 14C of cooling.  If you take an average 500g Hydrogen packet through that process, ignoring the Regulator overheating into a fine mist eventually, you produce (from what I understand) a net change of 16,800 J of cooling for the packet.  Bring that up to a 1kg packet, and you end up with 33,600 J of change.  Apply that to your single Electrolizer output (via isolated systems and Tempshift plates) and you don't have the cooling change to bring down your output by itself.  With two Thermo Regulators running 1kg packets however, you'd have 67,200 J of difference to apply, enough to bring your single electrolizer down with room to spare.  A two electrolizer process would require 3 Thermos (100,800 J) to adjust the output from the electorlizer down just shy of the target temperature.

I'm trying to make sure I've got the math and the mechanics straight.

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41 minutes ago, WanderingKid said:

Perhaps I need to be more explicit:

For example: A Thermo Regulator provides 14C of cooling.  If you take an average 500g Hydrogen packet through that process, ignoring the Regulator overheating into a fine mist eventually, you produce (from what I understand) a net change of 16,800 J of cooling for the packet.  Bring that up to a 1kg packet, and you end up with 33,600 J of change.  Apply that to your single Electrolizer output (via isolated systems and Tempshift plates) and you don't have the cooling change to bring down your output by itself.  With two Thermo Regulators running 1kg packets however, you'd have 67,200 J of difference to apply, enough to bring your single electrolizer down with room to spare.  A two electrolizer process would require 3 Thermos (100,800 J) to adjust the output from the electorlizer down just shy of the target temperature.

I'm trying to make sure I've got the math and the mechanics straight.

Then I change my answer to:

Yes, you have your numbers right, but you still do not want to cool the hydrogen.

edit: But you cant cool pipe contents with tempshift plates.. So you would have to cool them before you pipe them.

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19 minutes ago, Carnis said:

edit: But you cant cool pipe contents with tempshift plates.. So you would have to cool them before you pipe them.

It was on a vent/Gas Pump system on the isolated temperature adjustment side, so the Hydrogen was being exposed by diffusing it and then pumping up the heated results, along with some temperature control automation.

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Better build a room with thermo regulators and heat the hydrogen while cooling your oxygen down.

(Asuming the hydrogen is 1/8 of the oxygen the hydrogen and we asume we could heat your hydrogen till 120 degree (+50K). It would  counter the heat of a bit more than one thermo regulator running full time.)

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in my open-air system four wheezeworts is almost enough to cool my two electrolyzers. I'm not quite getting 25C but my bristle berry farm hasn't broken yet.

 

Remember that the cooling needs have nothing to do with how many electrolyzers you build - it's determined by how much air your dupes consume. Your electrolyzers can only make exactly this much oxygen, and no more.

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2 hours ago, WanderingKid said:

(snip) 

For two electrolizers, that means I'd be needing 104,510 W (J/s) to upkeep the heat removal of two full time (I know, they don't, but let's keep it semi-simple) electrolizers sharing a heat removal technique (Tempshift Plates in this case).

Trying a few techniques including wheezeworts and Temperature Regulators,

(snip) 

I can't comment on the amount of cooling needed as I'm at work and don't have the necessary numbers to look at your math, but 2 things jump out at me. 

1) Wheezeworts in a sealed room with enough hydrogen in it that they always do their full 1kg package cooling "only" provides 12kW/s of cooling. So you'd need 9 Wheezeworts to hit your calculated 104kJ/s cooling target. 

2) Thermo regulators only move heat from the material in the pipes to the machine itself so you still need to find 104kW of cooling somewhere. 1 Thermo Regulator running at max efficiency (full 1kg packets from merging 2 pumps) on Hydrogen moves approximately 34kW of heat (2.4 specific heat * 1kg packets * 14 degree change) from the hydrogen to whatever it is surrounded by.

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I'm really trying to avoid this becoming a base engineering question and keep it on what the values and mechanics of heat exchange are in the game, but since this is apparently becoming a technique discussion instead of a math discussion briefly:

Electrolizer production is being supported by Algae Deoxydizers that have cooled Algae to ~25C when pressure in the base falls too low.  Electrolizer Hydrogen is being shunted as quickly as possible into Hydrogen Generators, so it's not staying long.  External Hydrogen (or whatever else I'm using in the cooling chambers) aren't part of the Electrolizer process, so they're independent of raw cooling functionality I'm trying to manipulate.  This started with a massive Aquatuner boiler that works fine for my purposes.  I am now trying to reduce its complexity and size as well as research requirement impact by diving into the specifics.  I have a base that has a save point at 35 cycles in that I'm experimenting with techniques on.  I have plenty of alternatives to deal with the resultant thermal mess afterwards if I can dial this in as tightly as I want.

@beowulf2010 

Thanks.  12kW for Wheezeworts is what I understood via other tests and information.  That helps.  The Thermo Regulators in question were shoved off to another heat problem area and was simply used to try to control the Hydrogen for the cooling chamber only.  They were going to eventually either boil off the PH2O or explode due to their heat, but that wasn't what I cared about when I began experimenting on this. XD  34kW as a rough number makes sense to me, as the straight math came up with 33.6kW.   Thank ye.

 

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1 hour ago, WanderingKid said:

 

@beowulf201034kW as a rough number makes sense to me, as the straight math came up with 33.6kW.   Thank ye.

 

No problem. I mostly mentioned those 2 things as I've overlooked them myself in the past. Both in overestimating the effects of the Wheezeworts and of forgetting about the waste heat of the Thermo Regulators and Aquatuners.

But having the sunmary numbers available is always nice cause I now know that 3 Wheezeworts will easily keep a Thermo Regulator cool and that 4 Wheezeworts do a decent job at cooling down oxygen from hydrolyzers in about 16 tile long pipe radiators through high pressure hydrogen. (Well, they used to. I actually haven't tried it in the newest preview patch so it might have changed, hail SPOM). 

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20180427093540_1.thumb.jpg.794f9429dbab3d05cb24fd0955d7b10c.jpg

Seeing as pipe radiators are not working as intended (ignore R2, I built this in R1), this is how I cool my oxygen production. I'm lucky to have slush geyser on my map, however bare in mind that Aquatuning liquids is WAY more efficient at transferring heat than Thermoregulating them.

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18 hours ago, WanderingKid said:

I will start this conversation with "I am not a physicist, but I play one on TV".  I know the basics, and *think* I know what I'm talking about.  With that in mind, if one of the more conversant folks would be willing to double check my logic on this, that'd be appreciated.

The conversations starts with building an electrolizer rig in one of my typical builds, using two electrolizers in a typical Hydrogen/Oxygen cage to make sure they separate themselves.  Then the questions get interesting as I'm trying different techniques to get the heating problems in my base under control.  I know you can stick them into anti-entropy and cold biomes, but I want to try to enforce cooling them directly in the middle of my base.

So, I've built myself a happy little coolant room filled with cooled Hydrogen, cooled water, or other combinations in different techniques and I'm just not getting the amount of cooling I keep expecting to get, so I decided to sit down with the math.

So, basic problem is I'm trying to get 70C O2/H2 down to (for roundish numbers) a 25C result.  Ends up with a 45C delta change.

Specific Heat of O2 is 1.005 J/g/K, so I should require 45.225 j/g

Specific Heat of H is 2.4 J/g/K, so that would require 108 J/g

For a single electrolizer (for a second), those figures come out to:

  • 888 g O2 |  40,159.8 J
  • 112 g H   |  12,096 J
  • Total: 52,255 J

For two electrolizers, that means I'd be needing 104,510 W (J/s) to upkeep the heat removal of two full time (I know, they don't, but let's keep it semi-simple) electrolizers sharing a heat removal technique (Tempshift Plates in this case).

Trying a few techniques including wheezeworts and Temperature Regulators, I've found I just don't really have the throughput for cooling that I'd thought, and want to figure out if I've at least got the premise right for the heat to energy calculations before I (enjoyably) bang my head on my other mistakes. 

For those interested, one build I trashed was due to not cooling down the ducts in the ventilation first and not wanting to wait for them to stabilize.  It's been a mishmash of different things.  I should mention that I'm NOT in the preview build, though it shouldn't matter for this conversation.

My favorite solution to this is my waterfall build.  It works great, and once the initial cooling is done, the entire system powers itself -- providing you have 10 dupes OR a method of storing excess oxygen.  Just make sure you vent your coolant into the left side first to fill up the channel underneath, or you get into weird pressure problems.

Spoiler

oxygen1.thumb.JPG.fc14fdc195ab2b5a8d6f3bfb2fd714d4.JPGoxygen2.thumb.JPG.1ca831b06c86da07517c91f8d732e0ca.JPGoxygen3.thumb.JPG.387abcc05fc463a28f1e8daa04d50c37.JPGoxygen4.thumb.JPG.f8265bf4645f3007b8f75d37fbffaca1.JPG

Set the pressure sensor for the hydrogen pump to 'above 800' or something like that and the other two to 'above zero,' then set the temperature sensors to about 2 degrees colder than your desired temp.  Mine are set to 16c and the air comes out the vents around 18c.

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