Cooling Saltwater or Saltierwater

[Bosh]

I have cold brine geyser rather close to a hot salt water geyser and I want to use one to get cool water for bristle blossoms, oxyferns, and maybe sleet wheat. Would it be better to cool down the salt water (92kg/s at 95°C, 196s every 380s) with the brine (kg/s at -10°C, 193s every 461s) or to heat the brine, assuming it's even viable?

[Talo]

Can you have both run through a few metal tiles with radiant pipes? that will even them out. You can also have a loop with automation to make sure they leave at the right temp.

[Zuao]

Salt water SHC: 4.1 J/g K
Brine SHC: 3.5 J/g K
Salt SHC: 0.7J/g K

Inputing 5kg/s salt water (20,5 kW/K) results in 4.65kg/s of Water + 0.35kg/s of Salt.
(19.432 + 0.245 = 19,677 kW/K), that means ~4% of heat is deleted.

Now, 5kg/s Brine (17kW/K) results in 3.5kg/s of Water + 1.5 kg/s of Salt
(14.626 + 1.05 = 15,675 kW/K), about 7.8% of heat deleted.

I'd go with Brine, just because it deletes more heat when you run it through a Desalinator.
Also, it's way easier to get it to ~ -3 - 5 °C than it is to get the Salt Water if you want to use it for Wheat. Assuming your heat exchanger can even out the temperature and both have the same flow rate (you didn't type the rate of Brine), the equilibrium temperature is 44.4 °C, way too hot for any of the applications you mentioned. You'd need nearly 30kg/s of Brine to cool 10kg/s of hot water to less than 20°C.

Formula:
T = (m1*SHC1*t1 + m2*SHC2*t2)/(m1*SHC1 + m2*SHC2)
Use this to calculate the flow of Salt Water you need to get the Brine to a certain temperature. Strangle the flow of Salt Water by building a box of Insulation around it, then a Flow Valve.

[Boyks]

You can pump them out with the radiant pipes running along side each other through metal tiles to even out the temp. Stick liquid shut off valves controlled by the pipe thermo sensor at the end of the run of radiant pipes and this will deal with the fact that the salt water geyser is always going to be out producing the cool slush geyser.
If however you need all of that salt water as well as the brine then you will need to siphon it off in a manner which always ensures that the heat ex-changer is supplied first (otherwise the brine will just sit there waiting to be heated up) and then find some other way of cooling it down.

[Draconis]

I don't even use radiant pipes for this.

Usually I build three chambers next to each other, each 3 tiles wide and with metal tiles on the inner borders.
The outer two are filled with cold brine or cold slush (depends on the geysers available) and the middle one with hot water (from a cold steam vent) or saltwater from a satlwater geyser.

Each chamber has a thermal sensor, a pump and an outlet (to get the liquids in) (I tend to also use a sensor to close the outlet once the chamber is full enough)

The termal sensors in the outer basins activate their pumps when the liquid gets above 10°C, the middle one activates below 25.

Usually the three chambers equalize each other's termperatures, so you can have polluted water and brine at 10°C and water at 25°C - but usually the temperatures are somewhere within that range.
And if you process brine and polluted water to water and fill a tank from all three sources, the termperatures mix anyway, so you get water with a temperature somewhere in the middle. And all without radiant pipes and all the hassle.

Perfect for bristleberries and anything else that needs water below 30°. Might need a few cycles to get running properly, but once it runs it won't stop.

[Curiousfellow]

Originally posted by Draconis:

I don't even use radiant pipes for this.

Usually I build three chambers next to each other, each 3 tiles wide and with metal tiles on the inner borders.
The outer two are filled with cold brine or cold slush (depends on the geysers available) and the middle one with hot water (from a cold steam vent) or saltwater from a satlwater geyser.

Each chamber has a thermal sensor, a pump and an outlet (to get the liquids in) (I tend to also use a sensor to close the outlet once the chamber is full enough)

The termal sensors in the outer basins activate their pumps when the liquid gets above 10°C, the middle one activates below 25.

Usually the three chambers equalize each other's termperatures, so you can have polluted water and brine at 10°C and water at 25°C - but usually the temperatures are somewhere within that range.
And if you process brine and polluted water to water and fill a tank from all three sources, the termperatures mix anyway, so you get water with a temperature somewhere in the middle. And all without radiant pipes and all the hassle.

Perfect for bristleberries and anything else that needs water below 30°. Might need a few cycles to get running properly, but once it runs it won't stop.

I feel like this solution takes more energy than just using radiant pipes, since you have to get the water back into the pipes after it equalizes in the chamber.

[Draconis]

Originally posted by Curiousfellow:

Originally posted by Draconis:

I don't even use radiant pipes for this.

....

I feel like this solution takes more energy than just using radiant pipes, since you have to get the water back into the pipes after it equalizes in the chamber.

Possibly. It's 720W for the three pumps instead of 30W for three valves if I would use radiant pipes instead.

On the other hand it balances more water than the radiant pipes would, and the three pumps are not always online.

[Curiousfellow]

Originally posted by Draconis:

On the other hand it balances more water than the radiant pipes would, and the three pumps are not always online.

If you're not constantly drawing water from the setup, liquid valves actually become more efficient: A pump can only drain 5 kg of water at a time, but a valve can let 10 kg through provided your pipes are full. So that's 48 W/kg for a pump, and 1W/kg for a valve.

Edit: Wait, that's completely wrong, sorry. I could swear that liquid pumps filled pipes to half capacity, like gas pumps do, but aparantly I misremembered.

[Draconis]

Originally posted by Curiousfellow:

Originally posted by Draconis:

On the other hand it balances more water than the radiant pipes would, and the three pumps are not always online.

If you're not constantly drawing water from the setup, liquid valves actually become more efficient: A pump can only drain 5 kg of water at a time, but a valve can let 10 kg through provided your pipes are full. So that's 48 W/kg for a pump, and 1W/kg for a valve.

Edit: Wait, that's completely wrong, sorry. I could swear that liquid pumps filled pipes to half capacity, like gas pumps do, but aparantly I misremembered.

I actually used radiant pipes in the past, but always at some point that just stopped working properly because one or more of the pipes just did not get into the desired temperature range.
Maybe I'll give it a try on my next asteroid or rebuild my current one to see how this works out. I don't really know what I did wrong last time.

And by the way - energy actually never was a problem for me, that's whay the exra 720W did not hurt.