Publication at Linköpings Universitet - Digitala Vetenskapliga Arkivet - Theoretical Proof Of Concept For The Green Revolution Energy Converter
The GREC project group at Linköping University standing from left to right:
Gustav Edholm, John Malmdal, Lukas Haglund, Markus Eriksson
sitting: Oscar Magnusson
Development of a mathematical model, material analysis and physical model improvments
At Linköping University Sweden a group of students, Gustav Edholm, John Malmdal,
Lukas Haglund, Markus Eriksson and Oscar Magnusson did a full time project
"Theoretical Proof Of Concept For The Green Revolution Energy Converter" starting
beginning of February and running until the end of March 2022. They have publiched
a report with the same title describing the "Development of a mathematical model,
material analysis and physical model improvements" included below as a link to
Linköping University and the official publication :
Theoretical Proof Of Concept For The Green Revolution Energy Converter
Just follow the link above and download by clicking the document ikon in the
top right corner (Open Access in DiVA)
Alternative download in pdf format:
If we are to prevent global warming from exceeding 1,5 degrees we need innovative
solutions to be carried out in the next upcomming years. One of these potential
solutions is "The Green Revolution Energy Converter" (GREC) which has the
potential to change the future in both the sector of sustainable energy production
as well as in the sustainable transport sector.
The Green Revolution Energy Converter converts heat energy to mechanical energy
by heating up and then cooling down thin slices of an enclosed revolving "Work
Generating Volume" of a constant mass of gas (WGV). This revolution
generates mechanical energy in the form of pressure and volume waves. These
pressure/volume waves or rather pulses is in turn used to generate energy by
a piston, a pump, an electric generator...
The greater the temperature difference between heating up and cooling down,
the more energy.
The larger the work generating volume of gas, the more energy.
The more revolutions per minute, the more energy.
Inside the "Green Revolution Energy Converter" the thinly sliced enclosed
"Work Generating Volume", the WGV, is revolved in a circular motion between
a hot and a cold storage by a "Revolving Shutter" powered and controlled by
an electric motor. The electric motor consumes far less energy than what is
converted from the warm and cold storage by revolving the sliced Work
Generating Volume. In short; the heat energy from the warm and cold storage
is converted to mechanical energy by the revolving WGV.
The general gas law pv = mRt calculates the maximum power you can
get by revolving the Green Revolution Energy Converter one lap.
To get the Green Revolution Energy Converter to deliver one lap of power,
the Work Generating Volume, WGV, has to be filled by heat transfer only
with the available heat on the hot side to generate a pressure / volume
increase and then moved to the cold side where the WGV by heat transfer
drains its heat to correspondingly decrease its pressure / volume.
This wave or pulse of pressure / volume change may be used as force in a
piston and / or diaphragm, like operating a linear generator or anything
else that is able to use this movement. The power of this movement is power
per unit of time, so you want to fill and empty WGV as fast as possible.
In other words, you want as fast heat transfer as possible.
A Publication About Speed
How fast to fill up and empty the WGV with heat depends very much on the
thickness of the WGV as well as the "Heat Transfer Coefficient",
HTC, of the WGV, and in turn, the "Heat Transfer Coefficient" HTC of
the WGV depends on the turbulence in the WGV. The study done at the Linköping
University is very much about this. At a slow speed the gas in the WGV
will stay in a laminar flow with a very low HTC not able to deliver very
much power. When the revolving speed (rpm) of the WGV increases, the
flow in the WGV will, at a certain threshold, become turbulent and the
HTC will get an interesting starting value. This HTC value will increase
with the speed and will also increase with a higher temperature difference
between the hot and the cold storage.
The report reflects on the relations between
the turbulence in WGV,
the speed (rpm) of the WGV,
the volume of the WGV,
the temperature difference hot and the cold storage,
and determines how much energy different cases can deliver.
Abstract (as in the original publication)
The GREC is a new type of renewable heat engine that challenges
the current dominating combustion engines. By using renewable energy the GREC
offer a theoretical high efficiency, possibilities for large scalability and
a high power output. The GREC could therefore be a step into a better future
regarding energy production without consumption of fossil fuel. The report
has the aim to further develop the fundamental technology and present a
theoretical proof of concept of the GREC engine. This was performed by
establishing a mathematical model in order to produce realistic results
in terms of performance. As well as material analyzes and construction
improvements of crucial parts for future physical models.The mathematical
model was constructed with the help of the fundamental principals of the
Carnot-engine. With this in mind the development of the mathematical model
was formed by stating necessary thermodynamic assumptions, equations and
simplifications that focused on the heat transfer within the engine. The
material analysis focused on performing thermal and stress simulations on
selected parts with sought out material properties that would benefit the
efficiency for the GREC. With the use of a scaled Six Sigma quality approach
future construction improvements could be pinpointed and thereby give
guidance to future work. Results show that the GREC theoretically benefits
performance-wise by being constructed in larger scales and with higher
temperature differences between two heat reservoirs. Change of construction
materials also show increased performance, for example using bakelite for
isolation. The found construction improvements using Six Sigma across the
physical model show that a path to a solution of the problem could be
pinpointed. This will also contribute to GRECs development when solved.