Stirling with Rotary Annular Trilobic Pistons (SPRATL)

[Remundo]

Create the movement from one energy source, convert it into another more useful thanks to a suitable device, while having a good performance and respecting the environment,

these are the challenges facing SYCOMOREEN.


SYCOMOREEN is a family company which develops a whole family of inventions focused on renewable energies.

Today is a great day since I invite you to discover the third baby of SYCOMOREEN:

Stirling machines with Annular Rotary Trilobic Pistons (SPRATL)

adapted by Remundo from the original invention of Pascal HA PHAM

The patent was deposited on August 22, 2008 at the INPI.

In the immediate future, we do not publish the claims of this patent for legal and intellectual property reasons.

Nevertheless, you have access to all the figures, animated and descriptive gifs.

You can also consult the address http://sycomoreen.free.fr/
especially http://sycomoreen.free.fr/syco_francais ... ation.html


We await your reactions on this new machine with multiple uses: production of thermal, mechanical, electrical power, cogeneration, thermolysis, hydrolysis for various productions (hydrogen, metals ...) from clean energy and / or recycling of organic waste ...

For now, we are only developing our machines, but are open to any industrial partnership proposal.

Good reading and discovery!

Remundo for SYCOMOREEN

[Remundo]

Stirling thermodynamic cycles in Pressure / volume and Temperature / Entropy diagrams

[Remundo]

Annular trilobic rotary piston machines
with Stirling thermodynamic cycles

The invention relates to a device (1) constructed with machines with a trilobic annular piston, thanks to the two-stage character with unequal volumetries which they offer. in their generic version; a peripheral casing (CAR), a bi-arc core (NBA) and a trilobic annular piston (PRA) which rotates and slides between the core (NBA) and the casing (CAR), as described in PCT applications 03.3921, and INPI 07.5990 and 07.6157 filed by Pascal HA PHAM.
With at least two machines with a polylobic, and mainly trilobic (2,2F, 2C) annular rotary piston, Stirling thermomechanical conversions can be carried out with high efficiency thanks to the qualities of these machines, judiciously exploited:
1. The maximum and minimum volumes of the Stirling cycle are simply obtained by the volume of the chambers of the external stage larger than that of the chambers of the internal stage.
2. The isothermal phases of the cycle are much better respected thanks to the convection allowed by the movements and transfers of the heat transfer fluid within a machine.(2,2F, 2C) of uniform temperature.
3. The isochore phases of the cycle are perfectly respected by connections of chambers of the same type and movement between the hot machines (2C) and the cold machines (2F).
4. One or more regenerators (RGN), implantable between the machines (2,2F, 2C), allow, thanks to opposite and unidirectional flows of heat transfer fluid, an excellent level of internal heat recycling between isochoric cooling and warming of the Stirling cycle.

[Remundo]

Mechanical work and thermal transfer of the fluid on a cycle by a graphic approach

[Remundo]

The device (1) can operate with any hot source originating in particular:
- of the concentration of solar radiation, geothermal reserves, exo-energetic chemical reactions (combustion of biomass, waste, hydrocarbons…), nuclear fissions or fusions…
- industrial waste heat (ovens, foundries, various heat transfer fluids, dissipative effects in machines and installations),

and any natural cold source (ambient air, river lakes, basements, ice / snow, etc.) or obtained by artificial refrigeration.

The invention will be particularly well integrated into "Hyperthermic Traps of Direct Solar Radiation (PHRSD)" described in patent application 08.00627 from SYCOMOREEN (France) to develop solar electricity.

The following abbreviations will be used:
- " Tf " and " Tc "Respectively denote the absolute temperature in Kelvin of cold and hot sources,
- " SPRATL machine "Will designate a Stirling Annular Rotary Tri-Lobic Piston machine", according to the invention (1).

Many details will be given in the description below, dealing chronologically with the following themes: Stirling thermodynamic cycles, state and limits of the current art, proposed solutions (reminder of the characteristics of PRATL machines, leading to their exploitation in the Stirling, serial and parallel connection of several PRATL machines, movement conversion, thermal insulation precautions, principle and advantages of the regenerator, sealing of the chambers, extension to polylobic annular rotary pistons), dimensions and applications of the present invention, followed from its detailed description.

[Remundo]

Left column: imperfect cycle of current machines

Right column in strong line: cycle optimized by the SPRATL machine, smaller than the ideal cycle, but larger than the cycle of current machines

[Remundo]

Stirling thermodynamic cycles

The invention exploits, preferably with a gaseous heat transfer fluid, the Stirling thermodynamic cycle. A Stirling engine cycle performs the following steps, as illustrated in FIGS. 1A and 1B (P: pressure; V volume; T: temperature; S: entropy of the fluid)
- 1-> 2: Isothermal compression in contact with the cold source of temperature Tf, the fluid passing from a maximum volume Vmax to a minimum volume Vmin,
- 2-> 3: Isochoric heating at volume Vmin, with increase in fluid pressure,
- 3-> 4: Isothermal relaxation in contact with the hot source of temperature Tc, the fluid passing from the volume Vmin to Vmax,
- 4-> 1: Isochoric cooling at volume Vmax, with decrease in fluid pressure.

Steps 2-> 3 and 4-> 1 are isochoric and do not take or provide any work for the gas: 2-> 3 passes the gas from Tf to Tc and 4-> 1 from Tc to Tf.

On the other hand, the exchanges of mechanical work take place during stages 1-> 2 and 3-> 4:
- in step 1-> 2, the isothermal nature of the compression communicates a heat transfer from the fluid to the cold source and requires the supply of mechanical work to the fluid.
- in step 3-> 4, the isothermal nature of the expansion requires heat transfer from the hot source to the fluid: the latter thus yields a greater mechanical work than that which it received during compression 1- > 2, hence the motor character of the cycle.

Robert Stirling quickly chose to improve his machine by equipping it with a regenerator.

[Remundo]

Typical SPRATL machine

[Remundo]

This regenerator allows the fluid to recover during its isochoric 2-> 3 heating the heat that it deposited there during its 4-> 1 isochoric cooling. Thanks to this internal heat recycling, the thermodynamic efficiency of the Stirling cycle with regenerator is equal to that of the Carnot engine cycle:
RC = 1 - Tf / Tc

mechanical work produced by the fluid
with RC = ____________________________________
heat taken from the hot source by the fluid

For a receiving cycle, as illustrated in FIGS. 1C and 1D, the direction of travel of the cycle is reversed:
- 1-> 4: Isochoric heating at volume Vmax, with increase in fluid pressure,
- 4-> 3: Isothermal compression in contact with the hot source of temperature Tc, the fluid passing from a maximum volume Vmax to a minimum volume Vmin,
- 3-> 2: Isochoric cooling at volume Vmin, with decrease in fluid pressure,
- 2-> 1: Isothermal relaxation in contact with the cold source of temperature Tf, the gas passing from the volume Vmin to Vmax.

Steps 1-> 4 and 3-> 2 are isochoric and do not take or provide any work to the fluid. These are heat transfer steps only: 1-> 4 passes the fluid from Tf to Tc and 3-> 2 from Tc to Tf.
In step 4-> 3, the isothermal nature of the compression communicates a heat transfer from the fluid to the hot source and requires the provision of mechanical work to the fluid.
In step 2-> 1, the isothermal nature of the expansion requires heat transfer from the cold source to the fluid and forces the fluid to yield less mechanical work than that which it received during compression 4-> 3, hence the receptor character of the cycle.
The machine can then be used either in a refrigerator or as a heat pump, provided that mechanical work is communicated to it..

When the machine is equipped with a regenerator, allowing the fluid to recover during its heating 4-> 1 the heat that it deposited during its cooling 3-> 2, the thermodynamic efficiencies of the cycle are equal to those of Carnot, more precisely:

Heat taken from the cold source by the fluid
EF = __________________________________
mechanical work communicated to the fluid

EFC = Tf / (Tc - Tf) is the Refrigeration Efficiency

EFC is the efficiency of an ideal Carnot refrigerator.

Heat transferred to the hot spring by the fluid
EC = __________________________________
mechanical work communicated to the fluid

ECC = Tc / (Tc - Tf) is the Heat Efficiency.

ECC is Carnot's ideal heat pump efficiency.

These few fundamental reminders of thermodynamics will allow us to better understand the limits of the current art of Stirling machines and the multiple advantages of the present invention (1).

[Remundo]

Regenerator (RGN) and thermal insulation precautions