Buoyancy-Based Power Generation - Full Disclosure

[quantumtangles]

Interesting work. Thanks for sharing it Smokey.

Systems such as the system you propose (using buoyancy and gravity) are fascinating.

I made a modest stab at such a system myself, but abandoned it because the mathematics of the system indicated it could not constitute a useful machine.

Specifically, I once considered using castor oil as a working fluid in two linked tanks (the primary tank containing seawater so essentially buoyancy and gravity as with your invention).

I abandoned the idea because oil was to fall onto a turbine in a mostly empty cylinder, and then float up to the surface of a connected neighbouring cylinder filled with seawater (due to its relatively lower density...961 kg/m3 for castor oil and 1020 kg/m3 for seawater).

However the energy 'gained' through oil floating to the surface of the seawater was 'lost' later on because castor oil (compared to seawater) is a less dense working fluid and therefore the same flow rate provided less Force in Newtons to the turbine.

It all seemed to balance out even before taking into account system inefficiencies and flow rate/viscosity issues, so I abandoned the idea completely.

In passing, I had planned to use compressed air to move castor oil from the turbine tank back into the base of the primary tank where it would float to the surface and be 'siphoned' into the turbine tank.

Turning again to your invention, Low-Q makes an interesting objection that may have traction, namely the idea that work must be done to swing the buoyant objects into the primary tank from beneath. That makes some sense as a candidate objection and I would be most interested in your views on this.

Certainly we must take into account all forces and torques, even forces we may not want to take into account 

Thanks so much for sharing your work.

Interesting and thoughtful.

[sm0ky2]

ok, we shall now adress the concerns noted during the Reload Phase of the cycle. I have seen mentioned a few times now, the energy requirements to pass the B-unit into the lower portion of the large tank ; this leads me to believe that i was not clear about the state of the device during this phase.

Reload Phase:::

    After all B-units have risen to the top of the bouyancy chamber, generated power on their "rise" and "fall" cycles, and returned to the bottom of the small tank, the B-units are returned to their "0-state".
Meaning, that within the working fluid (water) they are at a state of weightlessness.
This is achieved by depressing the inner solenoid and compressing the halves of the B-unit, such that the verticle bouyant force = 0

Both tank lids are sealed during the reloading phase, therefore the tank pressure is equalized between both large and small tanks, prior to the inner door opening.
With pressure sabalized, the inner door open, and all B-units at their "0-state", the energy required to pass the B-units from the reloading chamber, into their starting position is negligible. There is no resisting force required to move them.

Once the B-units are in place, the inner door is sealed again, and the tank lids are opened - During this stage, as the tank lids are opened the large tank will be at a slightly less-than normal pressure, and "repressurize" to atmospheric pressure. The lower tank will be at a slightly higher than normal pressure, and de-pressurize back to ambient pressure. This is where a small ammount of water is transfered between the two tanks.
This is caused by the compressability of air at the top of the lower tank while the lid is closed, and the inner door opened. (Reload phase)


This takes the system back to the initial "starting" phase.
B-units are at the "0-State", virtual weightlessness.
The first units' solenoid causes the B-unit to expand, becomming bouyant and the generation process begins once again.

-----------------------------------------------------------------


So, to clarifiy, there is no significant energy requirements to force the bouyant chambers under the water,
because they are at a zero-bouyancy state during the reloading phase.

[quantumtangles]

Thanks for explaining the reload phase Smoky.

I would find it easier to understand the reload phase and indeed the entire system if we had a mathematical model.

A hypothetical machine of specified dimensions. This would enable us to calculate all forces acting on the system and also, we would know the power output in watts of the system.

I know comprehensive mathematical models of thermodynamic systems can be difficult to construct, but if you were to provide us with the dimensions (the size of each component), we could have a go at preparing a mathematical model for discussion and analysis.

It is an interesting system and it would be a thousand pities if we failed to examine it carefully using well established equations of motion and fluid dynamics.

So please let us have some system specifications (how big do you want this machine to be) so we can prepare a mathematical model taking into account gravity, buoyancy, viscosity, B unit relative smoothness, temperature, density, air resistance at operating temperature, power output in watts and power input in watts for any parts that require assistance during the power generating cycle.

This is not to say that our mathematical model will be absolutely correct right away (often there are forces one has failed to take into account) but it should be a good starting point for a more detailed analysis of the machine.

Over to you Smoky. Please provide dimensions for your system (simply the size of each component and the materials from which the components are constructed).

For example, water may have various densities in kg/m3. Would you like us to assume it uses fresh water of density 1000 kg/m3 or seawater of density 1020 or 1030 kg/m3?

It can be as big or small as you like, but mathematical focus requires us to have dimensions and materials information.

Thanks for explaining the reload phase of the cycle.

Kind regards,

[quantumtangles]

By way of example of required specifications, please let me know:

1. The diameter and height in metres of the primary tank and lower vessels.
2. The density in kg/m3 of the water in the primary/lower vessels. Also the flow rate in m3/s of any water lost from the unit (during phase transition) which will have to be replaced.
3. The material from which the B units are made (particularly the density and elasticity of the material) as well as their dimensions when 'inflated' and 'deflated', so we can calculate area in square metres and volume in cubic metres during each phase and the pressure in Pascals (= Newtons per square metre) and therefore the force in Newtons required to 'inflate' them.
4. The precise specifications of the motor powering the robot arm (power consumption in watts, angular velocity in radians per second or RPM, high torque or low torque, stepper motor, conventional motor etc).
5. The material from which the robot arm is manufactured so as to calculate forces applied to the robot arm motor during operation when moving B units and when repositioning itself to move other B units when not under full load. By what mechanism is the inner door opened and closed?
6. The speed in m/s of the B units during their up and down cycles.
7. The materials from which the connecting track (the track on which the B units travel) is made and the dimensions of the connecting track (to calculate weight when in and out of the water).
8. The total length of the track on which the B units will travel.
9. The mechanism by which the B units will be attached to the track on which they travel (eg are there any metal parts whose weight must be taken into account).
10. If the B units travel at different speeds (during the up and down cycles) how is this achieved by way of a single connecting track to which the B units are attached? Is there more than one track, in which event what are the specifications of the second track.
11. If the track is a loop, what is the estimated angular velocity of the loop (or in RPM how many times does the circuit of B units complete a full rotation in one minute?).
11. How is the motive force of the B units transferred to a shaft, pulley or other power transfer mechanism?
12. For the dimensions of the machine you will select, what type of alternator motor would you like to connect to the system (in terms of operating RPM, required torque in N.m and output in kW?

There will be other questions, but this is a preliminary list to give an idea of the information we will need to calculate the power output in watts of the machine.

The power output can then be compared with power consumed by the robot arm motor, air resistance, water resistance, other friction etc to check whether we can make a net gain in energy output (which is the whole point of the machine).

With full disclosure this may be calculated and discussed. If you can only provide some of this information, please provide as much as you can and I will do the calculations based on the information provided and best estimates for the missing parameters.

Kind regards,

[sm0ky2]

Nicely said QT,

i will do my best to define as many of those things as possible.

The "test unit" B-Units have all been roughly the same
the interior low-pressure chamber has a volume of
~0.07 Cubic Meters - this is based solely on test units, which have been constructed with a set parameter of low-pressure chamber-seals and inner hydraulic cylinders
The exterior size of the B-unit affects its mass, but not its relative bouyancy. The reason for this, is that the working fluid acts directly on the low-pressure chamber by design. This allows for an unrestricted freedom when choosing an exterior housing.

The most promising of these housings, will be composed of 3 layers of hexagon-plates, that interlock in a way that the entire casing becomes smaller as the B-Unit contracts, and becomes larger as it expands. i'll post the info on that as it progresses.

The size and dimensions of the Two tanks are determined by several system requirements, but are completely variable to suit the needs of the system.

There are certain perameters that must be met. The tank lids must seal at or below the specified water level, to minimize water transfer.
and the tank lids and inner door must meet the safety standards of the pressure imparted onto the lower tank when the inner door is opened.

The individual B-units ride along guide-rails that form a track through the system. the top of these rails are disengaged to accomodate the tank sealing. - this action can be a part of the tank-lid closing.

the interface for power generation might take one of several different forms.
a Coil / Magnet interface would allow for direct power generation, or possibly a geared mechanism to drive a rotary generator, connectimg arms that could attach to the B-Units during their entire cycle or at selected times for power generation. There are advantages and disadvantages to each or other approaches, depending on the needs of the system, and each will have its own associated energy costs and electrical production rates.

The phsycal force available, from gravity should be a simple calculation.
the Bouyant force, however, is completely variable, and user defined.

Displacement of the low-pressure chamber is roughly 85% of the ideal state under tap-water, and 82% in air.
giving us an underwater displacement of 0.0595 cubic meters at full expansion.
this may vary slightly with the density of the working fluid.
and potentially increase with technological advancement, such as the aforementioned exterior casing changes.

the inner pressure of the chamber can be calculated by the force to mass ratio that was used to determine the "effective displacement" .
essentially, even though the B-unit takes up more volume,. it is only displacing 0.0595 m^3 of water-mass. if that makes sense....
this is due to the design, that allows the exterior of the low-pressure chanber to "breathe", regardless of the exterior casing design.

even in the flying-hovercraft models, the B-unit still must breathe in this manner for the displaced-mass-bouyancy mechanics to function as intended.

The low-pressure chamber is not a true "vacuum". and the inner pressure is a function of the change in inner volume, and the elasticity of the low-pressure chamber seal. (rubber is used currently)

As far as the function of the opening/closing of the tanks and inner door, these can be the physical operation of the last B-unit during its'  ascent, or decent, or a portion of the energy generated can be used for these functions.

the total power generated will be a function of the bouyancy force used in the b=units, and the height of the large tank.
the height of the small tank is a fuction of the total number of B-units being used, and the space requirements needed to accomodate them.

The B-units will be at a Full-Negative Bouyant State during their descent, and thus gravity has its maximum acceleration force available, dissapated as a function of the downward power generation aperatus and linking mechanism.

To increase the speed and/or power of the upwards generation, you simple raise the B-unit to a higher bouyant state.

The aperatus to move B-units from the smaller chamber to the larger one, while the tanks are sealed (reload), has not been defined yet. But as a comparative example, we could use the stepper motor and arm mechanism found in a commercial Dishwashing Machine (resturant)
although our actual power requirements to move the B-units may be somewhat less than those standards.

The parameters of the actual system, are likely to be defined after selecting the power generation system and linking mechanisms.

from there you can determine your power requirements on the up and down strokes, and well as any additional moving track components that may add more drain  on the system.

from there you can determine the bouyant force required with the given working-fluid, and subsequent Positive-Bouyant-State that you must program the B-unit to change to during the start of the "rise" cycle.

Also, the physical size of the B-unit can be scaled to meet virtualy any requirements.
hovercraft will carry a much larger B-unit than the test models.
--------------------------------------------------------------

the energy available vs the energy required to initiate a bouyant state are two entirely different systems.

Examine the mass of a diver, fully strapped with gear, soaking wet, submerged under 80 feet of ocean water. and how much energy it would require to launch this diver to the surface at ~12 feet per second. This can be easily converted into a value of "displaced mass" needed to accomplish this task.

This value is then used to determine the size of the emergency life-vest, and its associated standard-pressure CO2 cartridge.
now,. compare the energy-value of the CO2 cartridge, to the energy of lifting the diver you just calculated a minute ago....

I understand the importance of hammering out all of the known energy values at each stage of this type of system,
but you must know what values you are attempting to compare.
because just like the diver and his pull-chord vest, that he hopes he never has to use....
The Bouyancy-Based Power Generation technology uses this vast difference in energy to produce a positive gain.
-----------------------------------------------------------------
Heres another example, place a rubber-bulbed eyedropped full of air into a plastic bottle full of water and screw on the cap.
now set-up a lever system to push on te side of the bottle with equal force each time.
and you push and the eye dropped sinks, not just sinks, but sinks with force, kerklunk on the bottom.
release the pressure and it shoots up to the top, again with force.

you are pressing lightly and only for a short time, after that you just hold the lever still and it maintains the pressure change in the bottle.

but the eye-dropper is able to produce usable energy both down and up, hitting the bottom with force, and bobbing at the top with force.

plus the pressure in the bottle returns your input energy back through the lever when you release it.

This shows that the two energy systems are not related, although they are interlinked.

one changes the pressure, and thereby the displacement
and the other is the bouyant result of that displacement.

Two entirely different systems. energy in and out does not correlate.

--------------------------------------------------------

Now with this in mind,. we can select arbitrary dimensions, fluid densities, Generator resistances, ect.
the mass of the B-unit can be defined as needed, the only restraint is that its mass must correspond to the range of B-states.
meaning the from the  Zero-B-state to the Maximum displacement, within the given fluid pressures. If the total-mass of the B-unit exceeds the displaced mass, it will not reach a Zero-B-State.

Height of the lower tank, number of B-units, ect. will determine maximum system capabilities, but the for calculations, one B-unit will suffice.

physics implies that the linear translation of the B-unit costs no energy, but in practice we must account for water-resistance, gravitational effects of its bouyant-state as friction on the track-rails.
so through the reloading process, as well as the linear-translation necessary at the top of the track, we must account for this as resistance (load) on our robotic arms, this will define the parameters of the motors needed, ect.

to make it simple, you could theorize a 5-volt generation system, that directly drives all the components in the system, the small motors, the controller circuits, any meters, sensors, timers, ect.

energy costs to move, seal, and lock the upper tank lids is a big unknown... there are not many systems like this in use to use as an example. i have seem some that use this principle, but the only one that comes to mind, is an aquatic reserve, that has an upper-pool linked to a lower pool. and to transfer animals from one to another the tanks must be sealed.

theres the weight of the lids, thickness, tensil-strength, ect. and rubber seal? pressurized locking mechanisms??
friction, resistance from the water.. so many unknowns there..

we can start with just defining the outlying parametres and requirements, then build this thing from there, adding / altering each component in the system and its energy drain on the total generating power available to us.