The technology behind the GREC
Simple concept, amazing potential
The technology behind the GREC has a simple concept
yet so innovative and powerful. The GREC is a Carnot engine using an
electric motor to move its "Work Generating Volume" between a hot and
a cold reservoir. This generates pressure pulses that in turn generate
work (connecting to a piston, a turbine, a pump, an electricity generator…).
- The larger the volume of air, the more energy.
- The greater the temperature difference, the more energy.
In thermodynamic terms, the GREC acts as “a closed system with a moving
boundary” that transforms an existing given temperature difference
into movement (kinetic energy).
Today's external heat engines are very limited in power due to limited
(small) cylinder volumes but not the GREC. The GREC uses very large
sliced heat transfer areas allowing a very large cylinder volume (Work
Generating Volume - WGV) which can benefit even from lower temperature
differences and be built for much higher power output.
The GREC is a closed system that heats up and cools down
a large sliced volume "WGV" efficiently, fast and repetitively, resulting
in internal pressure changes.
The illustration below shows a cross-sectional view of the GREC and
its internal parts.
An inside view of the GREC with the hot and cold blocks and their
respectively conducting fins in red and blue, and the electric operated
"Revolving Shutter - RS" in brown with its quarter openings which contain
the slices of the Work Generating Volume - WGV.
The hot and the cold blocks are separated by two insulating nil
blocks in transparent beige. The nil block with insulating nil-fins
situated closest to the viewer has been removed in order to see the RS
The closed GREC uses an internal “Revolving Shutter” (RS),
a pack of discs, to move the sliced gaseous volume column which is
held within a quarter of an opening called the Work Generating Volume
(WGV). The RS rotates the WGV between the conductive fins of a hot
and a cold block where they heat up/cool down quickly. This results
in internal pressure changes. Note that these are thin slices with
large area as they heat up and cool down faster than thick volumes.
- The more revolutions per minute, the more energy.
To prevent unwanted efficiency leaks, the GREC contains
two “nil blocks” with insulating fins placed in-between the hot and
the cold blocks. These insulating blocks prevent the simultaneous
heating up and cooling down of the Work Generation Volume allowing
a perfect Carnot cycle for every revolution.
The RS is not in contact with the fins and is free wheel
turned by a controller with logics and an electric stepper motor.
Although the purpose of the RS is only to move around gas, its revolution
is constantly controlled. This is done by the “Revolution Dynamic
Link” (RDL). The RDL software continuously adjusts the RS speed
according to input from the running application. It’s designed for
variable speed as well as a varying work load.
Here’s how the GREC works, step by step:
1. The Revolution Dynamic Link (RDL) positions the opening of the RS (the WGV)
to overlap with the hot block (red) of the GREC.
2. Conductive heat-transfer from the hot fins into the slices of the moving
gaseous volume (WGV) takes place.
3. The internal pressure of the GREC increases to actuate a connected device.
Like for example to force a piston to move a certain distance.
4. The RDL turns the gaseous slices of the Work Generating Volume over to the fins
of the cold block (blue), where the WGV will dump its heat.
5. The internal pressure drops and in the case of a connected piston, it
returns to its original position, i.e., pushed back the traveled distance.
6. To conclude a full Carnot cycle, the revolving process continues to
the hot block where it restarts from step 1.
Still a bit of a blur?
Check out the video animation of the GREC cycle: