Pressure Harvesting - from ocean depths

[Q-reeus]

at the moment I am attempting to work out what 10 cubic meters of 350000 kPa air pressure provides in Joules...
but my math skills are hopeless.

Don't bother, the underlying hope is hopeless.

 

[Quantum Quack]

Let's cut to the chase QQ. Seven pages.....

yes 7 pages dealing with people chasing a Perpetual energy claim that doesn't exist.

 

[Quantum Quack]

But at rock bottom, what I wrote in #128/#134 is the inescapable fundamental prohibition against realizing your idea(s). Time to admit that, yes?

what idea was that exactly?

 

[Quantum Quack]

Don't bother, the underlying hope is hopeless.

why not?
I am attempting to work out how much bang I will get for my buck if I do sink a variable pressure vessel big enough to hold 10 cubic meters of 35000 kPa of compressed air...

Don't worry the laws of thermo dyamics are not in any way threatened...

Mind you ... if I couldn't sink a variable volume vessel to gain pressurized air the laws of thermodynamics would be in trouble....

 

[Q-reeus]

yes 7 pages dealing with people chasing Perpetual energy .claim that doesn't exist.

But that's exactly what your proposed scheme(s) claim. Whether you realize it or not. Sorry but I detect you have dug in hard so no point in further discussion. There are sites devoted to 'over unity' ideas including hydrostatic ones - just search for them.

 

[Quantum Quack]

But that's exactly what your proposed scheme(s) claim. Whether you realize it or not. Sorry but I detect you have dug in hard so no point in further discussion. There are sites devoted to 'over unity' ideas including hydrostatic ones - just search for them.

8 pages and counting....
never discussed over unity in the OP... or under unity... that is on you...

 

[Quantum Quack]

But that's exactly what your proposed scheme(s) claim. Whether you realize it or not.

Maybe I should put a message at the bottom that states:
This is not about perpetual energy nor conflicting with the laws of thermodynamics.
It is merely an invite for people to consider the resources of a deep ocean that is a natural compressor and how that natural compressor can be exploited.

So to get back on topic:
Do you have any ideas about how this pressure resource offered by deep oceans can be exploited?

 

[Write4U]

As others have pointed out, just stick say a plastic drinking straw in a glass of water. Obviously there is no siphon fountain to be had.

Actually there is, albeit very small. Stick a straw in a glass of water and the water level inside the straw is higher than the mean. This is not a siphon function, but a capillary function, no?
I believe the term is "capillary action"

Capillary action (sometimes capillarity, capillary motion, capillary effect, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity.

It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid

https://en.wikipedia.org/wiki/Capillary_action

 

[exchemist]

I thought the air was about increasing displacement... which is primarily about over all size not weight. ( object fully submerged)

If the sub increases it's displacement (Size) it increases it's buoyancy

Listen: for the sub to blow its tanks it need to blast in a considerable amount of compressed air, in order to displace enough water to get its buoyancy to exceed its weight enough to lift it.

One litre of 10bar air requires about 2500Joules to compress it. This is quite a lot. Any many litres will be needed. See?

So any energy balance for the entire process MUST take account of the energy needed to compress the air the sub relies on to surface.

 

[exchemist]

Actually there is, albeit very small. Stick a straw in a glass of water and the water level inside the straw is higher than the mean. This is not a siphon function, but a capillary function, no?
I believe the term is "capillary action" https://en.wikipedia.org/wiki/Capillary_action

Just in case any reader is wondering about this, this does NOT produce a siphon.

The water may rise a little way up the tube if there is an attraction of its molecules towards the molecules of the straw. With a glass tube this is a strong effect. With a plastic drinking straw, it does not happen, because the water molecules are repelled by the plastic, not attracted to it.

However, even with glass, the water will never fountain out of the top, because once the water gets to the top the attraction is is no longer upward.

So there is no siphon.

Here endeth the red herring.

 

[Quantum Quack]

Listen: for the sub to blow its tanks it need to blast in a considerable amount of compressed air, in order to displace enough water to get its buoyancy to exceed its weight enough to lift it.

One litre of 10bar air requires about 2500Joules to compress it. This is quite a lot. Any many litres will be needed. See?

So any energy balance for the entire process MUST take account of the energy needed to compress the air the sub relies on to surface.

absolutely... I agree.
Do you have any ideas about how this pressure resource offered by deep oceans can be exploited?

 

[Write4U]

absolutely... I agree.
Do you have any ideas about how this pressure resource offered by deep oceans can be exploited?

No......

But I believe there is an alternate theory (woo?) which professes that heated water under pressure maybe used in the generation of a flammable fuel.

The Science Behind Dioxytetrahydride Gas

The production of the Dioxytetrahydride Gas is created using relatively low energy heat in an electromagnetic process. The resulting gas is flammable and the only combustible by-product of this Gas reverts back to the lower energy state of liquid water.....more

https://www.wateriontechnologies.com/science.asp

As to the science, I have no clue.

 

[exchemist]

Of what??

What weighs 1kg and fills 1 litre? Water. Incompressible water.

Not gas. A litre of gas weighs considerably less than 1kg.

A half litre of gas with a half litre of steel? Steel will not compress. You now only have a half litre of storage.

You will find - not matter how you cut it - you can't do this without either putting energy into the system somewhere, or having zero net effect. (Just like perpetual motion machines - which also fail due to inviolable thermodynamics).

Dave this is quite funny because you seem to be mixing me up with QQ.

I was looking for a simple scenario to illustrate to QQ what happens quantitatively. So I thought we could have a closed, empty container (or rather, one full of air at atmospheric pressure) with a mass of 1kg and a volume of 1 litre - a bit like his bike pump but with easier numbers.

This would have neutral buoyancy when immersed, no work would need to be done , by it or by any lowering mechanism, for it to sink 100m, to a depth at which the water pressure is ~10atm. (Its weight is 10N and the buoyancy force is that of the weight of the water displaced, i.e. also 10N.)

QQ then remotely opens a valve to allow the seawater to rush in and pressurise the air to 10 atm, at which point it will occupy 10% of the former volume, i.e. 0.1 litres. This will mean the buoyancy force is reduced to 10% of what it was, so now it requires a force of 9N to overcome its net immersed weight. Hence pulling it back 100m to the surface requires 900N of work to be done on it.

 

[Quantum Quack]

No......

it is currently being exploited. The deep pressure is being used to maintain constant pressure in submerged bulk variable pressure storage systems. Only to maintain constant pressure not provide compressed air. That is done by a surface pump.
see wiki: https://en.wikipedia.org/wiki/Compressed-air_energy_storage
Heading: Constant volume storage.

 

[exchemist]

absolutely... I agree.
Do you have any ideas about how this pressure resource offered by deep oceans can be exploited?

Obviously not, since, as everyone has been pointing out to you from the start, there is no pressure "resource" in the oceans. There is a pressure, but this is not stored energy and it is not a resource.

 

[exchemist]

it is currently being exploited. The deep pressure is being used to maintain constant pressure in submerged bulk variable pressure storage systems.
see wiki: https://en.wikipedia.org/wiki/Compressed-air_energy_storage
Heading: Constant volume storage.

Nope. It is a proposal. Nothing has been built.

And you are referring to the wrong heading. This would be a constant pressure system, not a constant volume system.

 

[Quantum Quack]

Nope. It is a proposal. Nothing has been built.

And you are referring to the wrong heading. This would be a constant pressure system, not a constant volume system.

yeah you may be right on both counts...

 

[Quantum Quack]

Obviously not, since, as everyone has been pointing out to you from the start, there is no pressure "resource" in the oceans. There is a pressure, but this is not stored energy and it is not a resource.

Do you deny that sinking a variable volume vessel can pressurize air (Potential energy) that can be exported to the surface?

 

[exchemist]

Do you deny that sinking a variable volume vessel can pressurize air that can be exported to the surface?

Obviously not.

What I deny - and this has now been said you five or six times, by at least four different people but seems not to have got through - is that you can do this without expending as much energy in the process as the energy you obtain.

So it is NOT a source of energy.

 

[Quantum Quack]

Obviously not.

What I deny - and this has now been said you five or six times, by at least four different people but seems not to have got through - is that you can do this without expending as much energy in the process as the energy you obtain.

So it is NOT a source of energy.

so a hose attached to the Variable volume pressure vessel down at depth, with say 35000kPa of pressure inside it would not provide 35000Kpa at the surface?