of course there is no free lunch. That is why your rejection is nonsense...
I suppose you think that solar energy is a free lunch as well?
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Pressure Harvesting - from ocean depths
- Thread starter Quantum Quack
- Start date
I suppose you think that solar energy is a free lunch as well?
Write4U
Valued Senior Member
OK, once again, people are trying to make this much to complicated. It is no different than installing a generator in a gravity fed water flow to generate electricity. The difference is that gravity water flow is replaced with high pressure water flow. Please remember that it is simple in principle.
The problem is adapting to an environment which produces high water pressure.
a) 800 meters down ocean exists high pressure water conditions. This is the existing "potential natural energy" medium. The "headwater source".
b) In order to allow this high pressure water to flow, a low pressure area must be created which is accomplished by installing a low pressure area (tank) inside the high pressure environment. A "tailwater reservoir".
c) Between the high pressure ocean and the low pressure tank we place a regulator valve.
d) Between the valve and the low pressure tank we place a reversible turbine generator/pump.
To install the system we lower a waterfilled tank down to the bottom of the ocean. After installing the valve and reversible turbine between the ocean and the tank, the valve is opened and the water in the tank is pumped out into the ocean. The vacuum that is created is replaced with air from the surface via a ventilator pipe. When tank is empty from water, we have established a low pressure tailwater reservoir.
The completed system now has;
High pressure ocean (headwater) --->intake/exit valve --->to turbine/generator/pump--->to low pressure tank (tailwater reservoir) . In principle not much different than a gravity water fed turbine/ generator.
To operate;
We open the intake valve and water from the high pressure ocean headwater flows with force to the low pressure tailwater tank, during which the kinetic force of the inflowing water drives the turbine and generates electricity , which is distributed to the surface electrical grid.
When the tailwater tank is filled no further intake is possible and the tank must be pumped empty again to provide a low pressure tailwater reservoir again.
This is accomplished by;
Full tank---> turbine/pump ---exit/intake valve ----> back to ocean headwater. This reverse flow is accomplished by using the turbine for pumping action which does does not generate, but uses electricity in this process.
Between in-flow and out-pump the system produces a net amount of electricity, which the article estimates at 80% net gain .
Please study the illustration and compare to the above procedure.
Note the large arrow indicating high pressure environment 800 meters down (headwater).
Follow the little arrow intake from ocean to tanks past the turbine generator. This is what creates the electricity.
Note the air in the tanks being replaced by tailwater and vented to the surface.
When tanks are full with tailwater, the system reverses and the tailwater is pumped back out into the ocean. Follow the little arrow output back into the ocean.
Note the surface air replacing the water being pumped out via the ventilator pipe..
That's it folks!
Nothing mysterious or scientifically complicated. The difference is adjustment to the environment. the principle remains the same as on the surface.
The problem is adapting to an environment which produces high water pressure.
a) 800 meters down ocean exists high pressure water conditions. This is the existing "potential natural energy" medium. The "headwater source".
b) In order to allow this high pressure water to flow, a low pressure area must be created which is accomplished by installing a low pressure area (tank) inside the high pressure environment. A "tailwater reservoir".
c) Between the high pressure ocean and the low pressure tank we place a regulator valve.
d) Between the valve and the low pressure tank we place a reversible turbine generator/pump.
To install the system we lower a waterfilled tank down to the bottom of the ocean. After installing the valve and reversible turbine between the ocean and the tank, the valve is opened and the water in the tank is pumped out into the ocean. The vacuum that is created is replaced with air from the surface via a ventilator pipe. When tank is empty from water, we have established a low pressure tailwater reservoir.
The completed system now has;
High pressure ocean (headwater) --->intake/exit valve --->to turbine/generator/pump--->to low pressure tank (tailwater reservoir) . In principle not much different than a gravity water fed turbine/ generator.
To operate;
We open the intake valve and water from the high pressure ocean headwater flows with force to the low pressure tailwater tank, during which the kinetic force of the inflowing water drives the turbine and generates electricity , which is distributed to the surface electrical grid.
When the tailwater tank is filled no further intake is possible and the tank must be pumped empty again to provide a low pressure tailwater reservoir again.
This is accomplished by;
Full tank---> turbine/pump ---exit/intake valve ----> back to ocean headwater. This reverse flow is accomplished by using the turbine for pumping action which does does not generate, but uses electricity in this process.
Between in-flow and out-pump the system produces a net amount of electricity, which the article estimates at 80% net gain .
Please study the illustration and compare to the above procedure.
Note the large arrow indicating high pressure environment 800 meters down (headwater).
Follow the little arrow intake from ocean to tanks past the turbine generator. This is what creates the electricity.
Note the air in the tanks being replaced by tailwater and vented to the surface.
When tanks are full with tailwater, the system reverses and the tailwater is pumped back out into the ocean. Follow the little arrow output back into the ocean.
Note the surface air replacing the water being pumped out via the ventilator pipe..
That's it folks!
Nothing mysterious or scientifically complicated. The difference is adjustment to the environment. the principle remains the same as on the surface.
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Write4U
Valued Senior Member
I used to scuba dive and am very familiar with the sub-marine environment, ok?
Let me ask you how do submarines dive and rise underwater. Do they use little rubber hoses and everybody sucks the air and water in and out of the sub to create high and low pressure areas?
Gimme a break . Your example is hopelessly ignorant of the submarine environment. Please keep your uninformed critique to yourself.
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Xelasnave.1947
Valued Senior Member
I am trying to help you and nothing would make me happier than to be able to say that I was to some all degree involved in your discovery.
None what so ever other than ...how is your proto type progressing?
You now present as irrational and that is unfortunate for you. To lash out at me and others suggests you are ego driven and that sends a message to all that follow your progress.
Why the need to be so?
Nevertheless I sincerely hope you can show you have the goods.
It boils down to this..you make a claim, that claim had been rejected, so I now wait for you to show with a working model that your idea works.
And I will be happy if you are correct.
I am not interested in proving you wrong but you seem to think that your reputation is on the line...behaviour here may detract from your credibility in other threads..that is of a concern to me...I don't want someone like you championing the debate on climate change for example having demonstrated such sorry behaviour here.
The folk who have commented on your unsupported proposal you dismiss with calls of nonsense when all they present is established physics...rant all you like I really don't care.
Alex
Ok... nothing to discuss... thanks for your irrational egocentric rejection.
Not at all. Solar energy converts photonic energy into electrical energy. Converting one form of energy to another is common and well understood; thermodynamics does a great job of explaining that. Coal plants convert heat from coal combustion to electricity. Nuclear plants convert heat from nuclear reactions to electricity. Hydro dams convert water flow to energy.
The mistake you are making is assuming that "pressure" = "energy." You made the same mistake above. That's like thinking that you can get energy directly from hot things, so an insulated hot brick will give you all the energy you ever need. Nope. It is the FLOW of heat that can give you energy, just like a FLOW of water from a high pressure to a low pressure can give you energy. Not high pressure (or high temperature) itself.
Ok a rational post.... finally.
I'll get home later and post a retort.
Google: "is air pressure an energy" to get an idea of what i am going to respond with
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Basically yes. The long duration submarines pump air in and out of chambers inside the submarine. They use compressed air to blow water out of their ballast tanks - and then pumps to return that compressed air to the tanks when they want to descend.
Xelasnave.1947
Valued Senior Member
As I said in effect...the ball is in your court..until you physically demonstrate that your idea works you have nothing but bluster...bluster may satisfy your ego but does nothing more.
Can you demonstrate with a physical model that you have more than bluster?
Can you?
Fail here and your credibility goes to the trash can..not because of the failure but because of your ego driven attempts to create facts from unsupported claims.
I look forward to seeing your working model on YouTube..I really do.
All the best.
Alec
Write4U
Valued Senior Member
Actually they flood the tanks with high pressure water to descend! If they put a generator in that in-flow path they could generate electricity while descending. Neat, huh?
But no one is pumping air in or out at all in this system. We are only ever pumping water out to create a low pressure area, which allows for a natural high pressure in-flow of water past the generator. Were not going up or down in the water, we're creating electricity . Stay with the idea of waterflow past a generator, just like in a river. Except we are just creating a low-pressure area in the tanks to facilitate a separate high pressure waterflow under water. That'll keep things in perspective .
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Ok.. I'll let you know....
But in the mean time ......uhm...do you mind...
billvon, found this... where P=pressure
https://physics.stackexchange.com/questions/216342/what-is-pressure-energy
https://physics.stackexchange.com/questions/216342/what-is-pressure-energy
Xelasnave.1947
Valued Senior Member
I am a mug so I have no idea if what you mean but no matter the ball is in your court.
Good luck.
Alex
Absoloodle ....
Write4U
Valued Senior Member
Write4U
Valued Senior Member
Interesting question.
What does the rest of the natural world pay for solar energy?
To plant life solar energy is not only free it is profitable, correct?
Sure there's a reason - YOU specified a scenario where the piston is fixed till sudden release at full depth! I was contemplating analyzing the new arrangement before hitting on the dynamics factor ignored in original scenario. Which has a non-intuitive feature I will cover later in response to an earlier post.
Regarding the free-piston slow-lowering case, I wasted too much time doing a detailed analysis before realizing it's as simple as this:
We assume a perfectly dissipationless adiabatic compression/expansion process operates over a full cycle. Which full cycle must end in the piston position being as at the start. That last part hasn't been factored in till now afaik. Because the process is notionally adiabatic it's fully reversible. Hence no net energy change occurs after the freely moving piston reversibly resumes it's original position when hauled back up to original elevation.
In reality there are all sorts of unavoidable loss mechanisms hence one wastes useful energy to no good end.
Concerning my #286, it's correct as it reads there but there is a funny issue involved. The relative amount of KE vs PE is a function of cylinder geometry - greater for a slender cylinder (drinking straw shape) vs squat cylinder (round coin shape) of the same volume.
So despite geometry dependent peak KE, as long as only reactive i.e. conservative forces act to oppose piston motion, there must be a full energy balance.
[EDIT]:
Oops, I got something basically wrong as per strike-through text above. From the basic standing-start formula for uniform acceleration, s = 0.5t^2, yields
t = sqrt(2s),
and as v = at, peak inrush v thus peak inrush P will go as L^0.5, not L, where L is cylinder length.
There is less overall dynamic boost for stored pneumatic energy for a squat cylinder. However compression is less also so buoyancy loss is less and I'm happy to assert it all balances out as expected. Why did I ever get involved here?!
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I apologize if I have confused you.
The bicycle pump plunger was only locked down prior to retrieval after compressing the air. The point of the exercise was to show that compressed air was indeed possible using a variable volume vessel such as a bicycle pump and that compressed air could be made available on the surface after retrieval.
Again I apologize for not making my earlier post clear.
Using that cryptic text idea:
From surface to 30 meters and back to surface:
--[-----v------] 0 at surface
---[-----------] 10 meters
-----[---------] 20meters
------[--------] 30meters
-------------[-] ==>------[-------] transfer air pressure to surface. (58.34psi)
-------------[-] 30 depleted of air pressure
-------------[-] 20
-------------[-] 10
-------------[-] 0 at surface
Shows
- A collapsing volume to the depth of 30 meters. (58.34 psi)
- The transfer of pressurized air to the surface (58.34psi)
- The retrieval of the vessel with out any air volume gained or remaining.
I hope this is not confusing the issue more so.
I am curious how the above would be taught to students of Fluid mechanics or renewables.
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No I haven't made a mistake. Pressure is in fact considered as energy. KE Kinetic energy and PE Potential energy and a couple of other more obscurely labeled energies.
All we are doing is transferring the potential energy of the ocean weight and VVSS's weight by way of compression of air into the VVSS.
The compressed air in the VVSS then has the PE of the ambient PE.
That PE is then ported to the atmosphere still as Potential Energy where it can be deployed later at leisure as energy.
http://hyperphysics.phy-astr.gsu.edu/hbase/press.html
Again there is no free lunch.
If we were not able to do the above the laws of thermodynamics would fail.
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See my amendment in #337. No-one has disputed one can compress air using ocean pressure, but it doesn't amount to useful harvesting, as said many times here. Logistics and large losses make it a losing proposition. Well maybe it could feature in some theme park if jazzed up with enough sparkle and razzmatazz.
