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tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,365

Re: Vacuum plus Water Gravity plus Air Compression Energy Storage

For SpaceNut re topic ....

Thank you for your continuing interest in and support of this topic...

We don't need to think about output at this point.  All we need is the actual energy to be stored.

The diameter of the pipe is not important, except that is is large enough so accommodate the movement of water from the base to the top.

Let's provide a time frame for this operation: 8 hours of sunlight.

In 8 hours we will move our ton of water from the bottom to the top of the structure.

You can compute the rate of water movement from this number.

You have a ton to move in 8 hours.

Let's try to nail down that single number.

Please do NOT use a turbine. Use a simple piston pump so you can size the load chamber correctly.

Each stroke of the piston will push X amount of water up the pipe.

With any luck, in the very next post, you should be able to give our readers a precise size for the pump.

We don't need any more tools.

We don't need any more background information.

It is time to nail down one number, or at most two or three relating to the pump.

(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,365

Re: Vacuum plus Water Gravity plus Air Compression Energy Storage

for SpaceNut re topic ...

We've established 8 hours as the time during which we can expect solar power to be available to move water from the lower tank to the upper one. Since we are working with metric units, and we are using a piston pump, let's size the pump to push one liter of water per stroke.

There are 480 minutes in 8 hours, so there are 28800 seconds.  Taking the average we would need 28.8 seconds to perform the cycle. In actuality the performance will depend upon the strength of the solar energy delivered to the motor driving the pump, but for now let's stay with 28.8 seconds per cycle.

Can you design (or find available) a piston pump that meets these requirements?

For sizing of the pipe, for convenience we can make the diameter of the pipe identical to the bore of the pump.

A detail for design of the system is that the vertical pipe can be filled with water, so the mass of that water can be added to the  work to be done lifting water from the lower tank.

For the energy computation, it seems to me reasonable to ignore the water in the pipe, and just focus upon the water that is moved out of the lower tank and the water delivered to the upper tank. The water is not the same, but the net effect is the same.

It should be possible to put that lift into the finished column.

Can you compute the work needed to lift a ton 10 meters?

The stored energy should follow.

Please show your work, instead of just results, which someone else would have to verify.

(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,365

Re: Vacuum plus Water Gravity plus Air Compression Energy Storage

For All....

ChatGPT4o wrote a little Python program that seems to capture the essential ideas I've been trying to develop ...

The program is intended to simulate a mechanical energy storage system that uses gravity and compression in a compact form. The study is limited to using one ton of water as the working fluid, and two cubic feet of ordinary air as the compression fluid. In the initial version of the program, we have a 10 meter elevation between the upper and lower tanks. The system is sealed, so there is no access to or influence from the external environment.

Python Program: Energy Storage System Simulation

Program Overview:
This Python program calculates the total work done in a sealed energy storage system, where water is moved between two chambers, one under vacuum and the other under compression. The key factors include gravitational work and compression of air in the upper tank as water is introduced over time.

Key Configuration Values:

• Initial Pressure (P_initial): 101.325 kPa (1 atmosphere)

• Upper Tank Volume (V_upper_initial): 2 cubic meters

• Pipe Diameter: 0.04 meters (4 cm)

• Pipe Length: 10 meters

• Water Density: 1000 kg/m³

• Piston Volume: 500 ml (0.0005 cubic meters per stroke)

• Total Runtime: 8 hours (28,800 seconds)

• Final Pressure (P_final): 202.65 kPa (2 atmospheres)

Important Derived Values:

• Pipe Cross-sectional Area: Calculated as [math] \pi * (diameter / 2)^2 [/math]

• Volume of Water in Pipe: Cross-sectional area multiplied by pipe length

• Gravitational Work: Force to lift water in riser pipe (using [g] = 9.81 m/s²)

• Compression Work: Work to compress air in the upper tank (isothermal compression)

Python Code

Imports and Configuration:

import math

P_initial = 101.325  # Initial pressure in kPa (1 atmosphere)
V_upper_initial = 2  # Upper tank volume in cubic meters
g = 9.81  # Gravitational acceleration (m/s²)
pipe_diameter = 0.04  # Pipe diameter in meters
pipe_length = 10  # Pipe height in meters
water_density = 1000  # Water density in kg/m³
piston_volume = 0.0005  # Piston stroke volume (m³)
total_runtime = 8 * 3600  # Runtime in seconds (8 hours)
P_final = 202.65  # Final pressure (2 atmospheres)

Calculations and Simulation:

pipe_area = math.pi * (pipe_diameter / 2) ** 2  # Pipe cross-sectional area
pipe_volume = pipe_area * pipe_length  # Water volume in the pipe
mass_water_pipe = water_density * pipe_volume  # Water mass in the pipe

def work_compression(p_initial, v_initial, v_final):
    return p_initial * v_initial * math.log(v_initial / v_final)

def work_gravity(mass, height):
    return mass * g * height

total_work = 0
time_elapsed = 0
P_upper = P_initial
V_upper = V_upper_initial

while time_elapsed < total_runtime and V_upper > piston_volume:
    work_gravity_stroke = work_gravity(mass_water_pipe, pipe_length)
    V_upper -= piston_volume
    work_compression_stroke = work_compression(P_upper, V_upper + piston_volume, V_upper)
    total_work += work_gravity_stroke + work_compression_stroke
    time_per_stroke = (work_gravity_stroke + work_compression_stroke) / 100
    time_elapsed += time_per_stroke

print(f"Total work done over 8 hours: {total_work / 1000:.2f} kJ")

Output:

• Total work done over 8 hours: {total_work / 1000:.2f} kJ

I have run this program using Python3, and the output shows .78 kilowatt hour of storage.

Python is a language that is accessible to almost anyone who is able to access the Internet with a computer.

It might even run on smart phones although I have no experience with that.

Python runs on Linux (where I spend most of my time), on Windows and on Apple.

I understand it can run on Android with the Linux extension.

In future posts I hope to work with ChatGPT4o to improve performance of the program.

This first attempt was just to see if we could get any results at all.

(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,365

Re: Vacuum plus Water Gravity plus Air Compression Energy Storage

I asked ChatGPT4o to convert the little Python program to a form that allows the operator to change the input variables. The resulting program produces results that I don't fully understand, so I'll be investigating those. However, the part of the program that computes work based upon water in the riser pipe seems to be working properly. By adjusting the length of the riser pipe to 400 meters, I was able to gain a report of 1 kilowatt hour of storage.  Here is the program. I invite all NewMars who have access to a computer to run the program. You'll  need to install some additional features for Python, but those normally install without difficulty.

# 2024/09/22 This is the official Version 2  of the Tkinter version of Energy Storage program

OK ... The Apache Internal Server error blocked the program.

Hopefully the AISE error will go away soon, now that kbd512 has the database installed in a test folder, and the new software is unpacked and ready for service. The only remaining tasks (that I know about)  had to do with placing the correct text into a file, and a table in the database.

Hopefully these steps will happen soon!
(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,365

Re: Vacuum plus Water Gravity plus Air Compression Energy Storage

The version of the Mechanical Energy Storage simulation that is available at the link below offers the ability to change some input parameters.

By far the parameter that has the greatest effect is the riser pipe height. 

https://www.dropbox.com/scl/fi/no55179o … 9gdsi&dl=0

I hope that someone in the current NewMars membership will download the program and attempt to run it.

The program requires adding features to Python, but for most operating systems that appears to be relatively easy to do.

I'm definitely interested in feedback on the design of the program and it's operation.

My guess is that there must be at least one design flaw present. This is an early version.

(th)

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,365

Re: Vacuum plus Water Gravity plus Air Compression Energy Storage

This version of the little Energy Storage calculator shows the contributions of the gravity component and the compression component separately.

I'll attempt to paste the code here. If that fails (as I expect) I'll put the code on Dropbox and offer a link for anyone who might like to run this version (#04)

# 2024/09/25 if all has gone well, this is Version 04
# Version 03 was provided, and code was added to show two new outputs

As expected AISE occurred. The new version of FluxBB should be able to handle this kind of request.
We are very close to having the new version running on the Mars Society servers.

Here is a link to the new version on Dropbox:
https://www.dropbox.com/scl/fi/8zheesih … kdpxo&dl=0

The program has been modified to show output fields to the right of the input fields. 

(th)