Do pipes exchange heat when within wall tile?

[SchlauFuchs]

Hi,

at current state, do pipes that run within a wall exchange heat with the wall or surrounding gases and liquids?

[Neotuck]

yes

[martosss]

2 minutes ago, Neotuck said:

yes

That's quite ... short... and not very correct.

All comments below are for v.275206, so the latest update might be different.

Pipes are buildings and, thus, exchange heat with the cell behind them. If that cell is a tile, it depends what kind of tile it is.

• vacuum doesn't exchange heat(proven from another thread showing that cooling with pipes doesn't work in vacuum)
• Insulated abyssalite tile almost certainly doesn't exchange heat with pipes(I tested this with different pipes inside, they do heat depending on their contents, but the tile stays unchanged)
• Insulated non-abyssalite tile exchanges heat veeery slowly(just tested it, heat transfer began at 100° difference, I think it's because the insulator buff gives (2/255)² coefficient in the calculations)
• non-insulated abyssalite tiles exchange heat veeeery slowly(probably similar to the upper case)

 

• non-insulated non-abyssalite tiles exchange heat relatively fast
• other kinds of cells(e.g. gases/liquids) do exchange heat.

The exact formula? ... I'm not sure... the best I can give you is this link:

 However, it is old and some things have been changed. The changes I know of:

1. insulated pipes now use minimum thermal conductivity between the pipe and the cell.
2. other pipes use log-average between the pipe and the cell.

As a conclusion:

• any pipe in insulated and/or abyssalite tiles is fine
• insulated abyssalite pipe is fine up to ~40° difference with surroundings, then it heats up, but it exchanges heat with contents veeery slowly
• insulated non-abyssalite pipes do heat fast, but they exchange heat with contents veeery slowly(insulated ceramic pipes(@1600°) heat water(@22°) 0.1° for 4-5 tiles distance
• non-insulated abyssalite pipe heats veeery slowly, but will heat to the outside temperature, they also exchange temperature with their contents veeery slowly(Abyssalite pipes through 2000° magma heat water by 0.1°/5 tiles - not much)

 

• All other pipes aren't fine, they heat ~fast and exchange heat ~fast

 

So ... regarding the "yes" comment ... I slightly disagree

[Neotuck]

4 hours ago, martosss said:

That's quite ... short... and not very correct.

sarcasm 

[martosss]

52 minutes ago, Neotuck said:

sarcasm 

You just wrote it while I was replying... and I just had to quote you!

[Coolthulhu]

8 hours ago, martosss said:

That's quite ... short... and not very correct.

It's not a very correct response.

Technically all tiles exchange heat with pipes in them. There is no special case that makes abyssalite on abyssalite not exchange heat. The formula is most likely the same as usual. It's just that in some cases, this exchange ends up being effectively (or actually?) zero, possibly due to floating point math causing it to round down to 0. With earlier heat math, it was possible to "overpower" this by causing a sufficient heat difference.

If you could build pipes in neutronium tiles, there would actually be a special case there. Neutronium doesn't "exchange 0 heat", it doesn't participate in heat exchanges at all, like vacuum.

[martosss]

2 hours ago, Coolthulhu said:

It's not a very correct response.

So you think Neotuck's response is the proper way to answer the question? So when you make pipes you don't care if they exchange 0.1%(like abyssalite) or 99%(normal pipes) heat(0.1 and 99 are figurative numbers, but probably not far from the truth)? I'd say that 1000 times difference would make a difference worth mentioning.

2 hours ago, Coolthulhu said:

Technically all tiles exchange heat with pipes in them. There is no special case that makes abyssalite on abyssalite not exchange heat. The formula is most likely the same as usual.

I posted the link, you can see all the clamps and the "If" cases where no transfer happens(e.g. Vacuum or temperature exchanged <10^(-4)J). And the insulator buff(i.e. 0.00001 thermal conductivity) makes abyssalite quite special, just like insulated tiles are different from normal tiles.

[SchlauFuchs]

So, if I get this right, it makes sense to run pipes with hot content within insulated walls where present, and even a Radiant pipe made from Wolfram within an Abyssalite Insulated Wall would not exchange heat with the room interior in an amount worth mentioning? 

[martosss]

I haven't tested radiant pipes, but if you're building a pipe inside abyssalite wall, just build a normal one(sandstone or whatever), since it will save you the materials. If you want to test it - sandbox mode is there for you - just spam some pipes and see what happens

[erso]

On 31.7.2018 at 3:52 AM, SchlauFuchs said:

So, if I get this right, it makes sense to run pipes with hot content within insulated walls where present, and even a Radiant pipe made from Wolfram within an Abyssalite Insulated Wall would not exchange heat with the room interior in an amount worth mentioning? 

short version: The whole thing is heavily dependent on the material and the low conductivity of abyssalite is not as effective in combination as many think.

___

In my understanding, the relevant formula is: (A-B)/(ln(A)-ln(B))

for example:

• Liquid = CrudeOil (2 W per K)
• LiquidPipe = SandStone (2.9 W per K)
• Tile = Abyssalite (0.00001 W per K)
• thermal energy transfer beween liquid and pipe is ~ 2.422 W per K
• thermal energy transfer beween pipe and wall is ~ 0.231 W per K

In case of the tile is insulated (thermal conductivity * 0.03125 [from insulated]):

• thermal energy transfer beween liquid and insulated pipe is: ~ 0.6171 W per K
• thermal energy transfer beween insulated pipe and wall is: ~ 0.001 W per K

With a radiant wolframite liquid pipe (15 W per K * 2 [from radiant]) instead of an sandstone liquid pipe:

• thermal energy transfer beween liquid and radiant pipe is: ~ 10.3395 W per K
• thermal energy transfer beween radiant pipe and wall is: ~ 2.0115 W per K

With a radiant wolframite liquid pipe (15 W per K * 2 [from radiant]) and an insulated abyssalite tile (0.00001 W per K * 0.01 [from insulated]):

• thermal energy transfer beween liquid and radiant pipe is: ~ 10.3395 W per K
• thermal energy transfer beween radiant pipe and insulated wall is: ~ 1.537 W per K

[SchlauFuchs]

Okay, lets bring up a definitive example with calculations to see if we get it right. I will set up a time series google sheet for that. Tell me more about the factor 5 you mentioned, is there any source for that?

 

[Christophlette]

The wiki says insulated tiles transfer only 5% of their usual rate. So 5% of their thermal conductivity.

I guess we can make the same assumption for insulated pipes. 

For radiant I have no idea though. 

[SchlauFuchs]

I will use 5% in my spreadsheet, and maybe @Cheerio or another developer can throw in a number for Radiant pipes, please?

[martosss]

In the post that I mention above the coefficient for insulated pipes and tiles is quite different - (2/255)² ~ 0.00006 (6*10^(-5)). Not sure what is the right one, but I tend to believe that post more than the wiki.

[erso]

Radiant pipe = Element thermal conductivity * 2

Insulated pipe = Element thermal conductivity * 0.03125

Insulated tile = Element thermal conductivity * 0.01

[Christophlette]

2 hours ago, martosss said:

In the post that I mention above the coefficient for insulated pipes and tiles is quite different - (2/255)² ~ 0.00006 (6*10^(-5)). Not sure what is the right one, but I tend to believe that post more than the wiki.

I would not believe the wiki too much. It is a bit outdated and not very accurate most of the time. Maybe you can trust erso !

[martosss]

1 hour ago, erso said:

Radiant pipe = Element thermal conductivity * 2

Insulated pipe = Element thermal conductivity * 0.03125

Insulated tile = Element thermal conductivity * 0.01

So where do you get these numbers? And what formula do you plug them in? I also saw the comment about the log average and read what it means, but I'm still not 100% sure in which cases the log average is used and in which cases it isn't. 1 post that I read said that insulated pipes use minimal thermal conductivity. In this case erso's post wouldn't be true ... the 0.01 for insulated tile also isn't true if we trust the thread that I  linked, which says it's 0.00006 ... so, @erso , can you explain a bit more where you get those magic numbers?

[erso]

Just now, martosss said:

So where do you get these numbers? And what formula do you plug them in? I also saw the comment about the log average and read what it means, but I'm still not 100% sure in which cases the log average is used and in which cases it isn't. 1 post that I read said that insulated pipes use minimal thermal conductivity. In this case erso's post wouldn't be true ... the 0.01 for insulated tile also isn't true if we trust the thread that I  linked, which says it's 0.00006 ... so, @erso , can you explain a bit more where you get those magic numbers?

Ingame building properties + material info + my steam powered calculator.
Usually the numbers in the game are right, so I used the numbers in the game as a basis.

 

[martosss]

1 hour ago, erso said:

Ingame building properties + material info + my steam powered calculator.
Usually the numbers in the game are right, so I used the numbers in the game as a basis.

 

Quote

Radiant pipe = Element thermal conductivity * 2

Insulated pipe = Element thermal conductivity * 0.03125

Insulated tile = Element thermal conductivity * 0.01

So where do you see those numbers for the different type of pipes? It just says "a good insulator".

[erso]

56 minutes ago, martosss said:

So where do you see those numbers for the different type of pipes? It just says "a good insulator".

And i know Granite has 3.39 (W/m)/K. (Ingame numbers are rounded to the third decimal place)

 

[martosss]

lol Those are just the numbers from the material that the tile is made from. They are not the same if you choose a different building material. Moreover, the difference between insulated and radiant and the other pipes is hidden, you can't see it in those tip messages. And even if you see those numbers, you don't know in what formula they're plugged in(and it's not the typical physics formula!). So good luck with that.

[erso]

22 minutes ago, martosss said:

lol Those are just the numbers from the material that the tile is made from. They are not the same if you choose a different building material. Moreover, the difference between insulated and radiant and the other pipes is hidden, you can't see it in those tip messages. And even if you see those numbers, you don't know in what formula they're plugged in(and it's not the typical physics formula!). So good luck with that.

I'm not sure if you're right here. The ingame information does not seem arbitrary.

The calculated factors can be applied to all materials throughout and correspond exactly to the properties. (Granite is just an example...)

[martosss]

1 hour ago, erso said:

I'm not sure if you're right here. The ingame information does not seem arbitrary.

The calculated factors can be applied to all materials throughout and correspond exactly to the properties. (Granite is just an example...)

Oh, wow, I take it back, those messages are a bit more useful than I thought. And still, That doesn't tell you that there are hidden multipliers for "cross section area", or for building-cell transfer ...  It also doesn't say if there are cases where NO TRANSFER happens, e.g. temperature range .... I did tests where I try to heat a pipe  ... if the temperature difference is sufficiently small for abyssalite insulated pipe(40° between pipe and surroundings)the pipe will never heat. And even if it heats, it doesn't transfer heat to its contents... so the transfer pipe-contents is different from pipe-surroundings... So you can look at those numbers but they don't tell you the whole story. That unreliability is one bad thing about this game - you read that 3.39 and 0.1 and you think "hm, it'll transfer heat 30 times slower"?, but in fact it might be many times better than that ... or worse....

And I understand the rounding, but sometimes you need to know the exact value:

You look at abyssalite pipe vs insulated abyssalite and it says thermal conductivity 0.000 in both cases ... so what does that tell you? The two pipes act very, very differently.

Anyways, I really didn't see the difference in those messages, so good point there!

 

[SchlauFuchs]

I tried to generate a time series base on the numbers, to see how things would interact:

In this example I have an Insulated Tile made from Abyssalite with a temperature of 200 degrees as start value, a Radiant Liquid Pipe made from Tungsten, starting at 20 degrees, filled with 10l crude oil, 500 degrees, surrounded by 2kg of Oxygen, 20 degrees.

But I think there must be some flaw in my math, as the oxygen gains far too much heat from the abyssalite insulated tile (this is 600 seconds scale). Please review my calculations t https://docs.google.com/spreadsheets/d/1ce2DjdYOXkKqsm0kPtPgHFRaUh2VnonvKoH-tZQbjZk/edit?usp=sharing

Cheers,

SF

[wachunga]

The problem with your math is that averaging, log or otherwise, isn't a thing. Despite it being the common wisdom on these forums it doesn't exist. Or perhaps it exists in some specific circumstances, but I have yet to find evidence of it.

Edit: Also it looks like your sheet is using H2 for everything instead of H3 or H4 where appropriate.

 

Cell/Cell transfers are a lowest conductivity relationship.

Cell/Building transfers are a multiplicative relationship.

Pipe/Contents transfers are a multiplicative relationship.

No special rules for insulated/radiant vs normal, it's just a conductivity multiplier. 2x for radiant pipes, 1/32 for insulated pipes, 1/100 for insulated tiles.

 

I tested this quite extensively in the past and some brief retesting doesn't show anything has changed. But you shouldn't believe me more than anyone else. It's trivially easy to test in debug and I encourage you to do so. I'd be happy to know if I missed a change.

 

Some past explanations: