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:

Development_Of_The_Green_Revolution_Energy_Converter.pdf

Background

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.

Technical

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.

Theory

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.