Endothermic reaction cooling without the use of thermoelectrical cooling?

[Bobgotyeeted]

Hello, people of the LTT forum, I was thinking that why don't PCs use endothermic reactions for cooling PC components? If you don't know already, an endothermic reaction is a reaction between two elements forming a compound, this reaction makes a negative temperature change by using the energy of the surrounding environment for the reaction between the two elements. This quite obviously makes the environment cooler. Now, in theory, if we made the surrounding environment say a CPU for example we could cool the CPU with the reduced temperature from the endothermic reaction. The problem with this is that we couldn't use a traditional, copper-block water cooling design. This is because the elements and the compounds produced from the reaction would react with the copper block. For instance, if we used an ammonium nitrate solution it would create copper nitrate which would corrode the block itself. We could use a nickel block but in a production and manufacturing sense, it would be expensive. My Proposition is, is it economically viable to make a cooling solution of this kind or does it already exist? 

[tkitch]

short answer:  It's 110% entirely economically infeasible to do this.

 

1) it's wasteful.  What do you do with the compound after the reaction is completed?

2) refilling your "cooler" is not going to be fun to do regularly

3) way more risks involved than with air cooling, or watercooling

4) how do you control/stop the reaction when the CPU is idle, or off?  Cuz you don't want frost forming on your cooler.

[lewdicrous]

4 minutes ago, Bobgotyeeted said:

is it economically viable to make a cooling solution of this kind

It'll already be on the market if it was viable in any way.

Reactions don't last forever. You'll need to constantly replenish the reagents and clean off the products.

[AbydosOne]

1 minute ago, Bobgotyeeted said:

My Proposition is, is it economically viable to make a cooling solution of this kind or does it already exist? 

You do realize that endothermic reactions don't run forever right? Where are we going to dump all this ammonium nitrate solution when the reaction is complete? It takes energy to create and transport endothermic reaction components, probably much moreso than just running a chiller.

 

Ammonium nitrate is not exactly something I (or a slew of three-letter organizations) want sitting around my house.

[BobVonBob]

I don't know everything needed to be certain of my answer, but I'm reasonably sure chemical computer cooling isn't possible.

 

The main issue is that you don't only need an endothermic reaction, you need a sustained endothermic reaction. That means either constantly feeding in new reagents, which is pretty obviously not viable, or reversible reactions. Reversing an endothermic reaction must necessarily be exothermic, and that reaction (or series of reactions) will either have a positive or negative temperature coefficient. In both cases the reverse reaction itself will need to be cooled to prevent the reaction from stalling (bad) or running away (very bad).

 

The final result being you've successfully moved heat from one place that needs to be cooled, to another place that also needs to be cooled. You could use chemical reactions to cool that too, but then you have the same problem. At some point you need to break the chain with a cooling method that doesn't need to be reversed (at least on an individual level), like throwing the heat out into the air with a radiator, and at that point why bother with an intermediate chemical step?

[Ryuikko]

36 minutes ago, Bobgotyeeted said:

ammonium nitrate

Considering ammonium nitrate is a 3 on the reactivity side of the fire diamond, I wouldn't be exactly prone to constantly Introduce heat into the solution 

Cough* cough* oxidizer cough* cough* main ingredient in high explosives

[BiotechBen]

Technically endothermic cooling already exists for cooling PC's it's just exotic/XOC cooling. The "use an air conditioner to cool" compresses the refrigerant in the loop and then the rapid expansion into the hot side of the loop is what carries the heat away. Easily reversible reactions that are endothermic generally don't make sense as they are only lightly endothermic and would be easily overwhelmed with the amount of heat PC components put out. You'd need something that was on the scale of hundreds of watts/mol K to be able to handle the heat transfer in the scale that PC cooling would require to have it solely be a reversible reaction cooling. 

 

Those particular reasons are why water is preferred, it has high heat capacity and then aluminum has excellent heat transferrance to be able to dissipate heat. 

[IkeaGnome]

  

42 minutes ago, Bobgotyeeted said:

ammonium nitrate

This is the base solution for a lot of explosives we use in mining and is very reactive on it's own. It's an amazing oxidizing agent. 

https://pubchem.ncbi.nlm.nih.gov/compound/Ammonium-nitrate

Quote

Stability during transport: If heated strongly, decomposes, giving off toxic gases and gases which support combustion. Undergoes detonation if heated under confinement.

U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

 

As a side effect, if you start buying enough of this to keep your computer running you will have people that work for 3 letter organizations knocking on your door. 

[Bobgotyeeted]

2 hours ago, Ryuikko said:

Considering ammonium nitrate is a 3 on the reactivity side of the fire diamond, I wouldn't be exactly prone to constantly Introduce heat into the solution 

Cough* cough* oxidizer cough* cough* main ingredient in high explosives

It was just used as a mere example of an endothermic reaction.

[Bobgotyeeted]

2 hours ago, BiotechBen said:

Technically endothermic cooling already exists for cooling PC's it's just exotic/XOC cooling. The "use an air conditioner to cool" compresses the refrigerant in the loop and then the rapid expansion into the hot side of the loop is what carries the heat away. Easily reversible reactions that are endothermic generally don't make sense as they are only lightly endothermic and would be easily overwhelmed with the amount of heat PC components put out. You'd need something that was on the scale of hundreds of watts/mol K to be able to handle the heat transfer in the scale that PC cooling would require to have it solely be a reversible reaction cooling. 

 

Those particular reasons are why water is preferred, it has high heat capacity and then aluminum has excellent heat transferrance to be able to dissipate heat. 

Thanks 

[Bobgotyeeted]

2 hours ago, IkeaGnome said:

  

This is the base solution for a lot of explosives we use in mining and is very reactive on it's own. It's an amazing oxidizing agent. 

https://pubchem.ncbi.nlm.nih.gov/compound/Ammonium-nitrate

 

As a side effect, if you start buying enough of this to keep your computer running you will have people that work for 3 letter organizations knocking on your door. 

I know haha i was just using it as an example of an endothermic reaction in context

[Bobgotyeeted]

2 hours ago, tkitch said:

short answer:  It's 110% entirely economically infeasible to do this.

 

1) it's wasteful.  What do you do with the compound after the reaction is completed?

2) refilling your "cooler" is not going to be fun to do regularly

3) way more risks involved than with air cooling, or watercooling

4) how do you control/stop the reaction when the CPU is idle, or off?  Cuz you don't want frost forming on your cooler.

I didn't state the fact that would it be feasible to create a sustained endothermic reaction mb

[SorryBella]

17 hours ago, AbydosOne said:

Ammonium nitrate is not exactly something I (or a slew of three-letter organizations) want sitting around my house.

16 hours ago, IkeaGnome said:

This is the base solution for a lot of explosives we use in mining and is very reactive on it's own. It's an amazing oxidizing agent. 

https://pubchem.ncbi.nlm.nih.gov/compound/Ammonium-nitrate

And of course, reminder that this thing is the reason why Lebanon lost its biggest port.