SYstems for COnversion of MOtions and REnewable ENergies
 Frequently asked questions   
Stirling's Engines with rotary annular trilobic pistons / Machines de Stirling à Pistons Rotatifs Annulaires TriLobiques (SPRATL) / Stirling-Maschinen mit drehenden drei-Lappen ringförmingen Kolben / Máquinas de Stirling para pistones giratorios anulares tri-lobulos

Back to the FAQ's index

10/08/2010 : How works a SPRATL engine and what are the advantages ?
10/12/2009 : What are the fields of application of a SPRATL engine ?
14/05/2009 : What are the genesis and the main ideas of the SPRATL concept ?

25/01/2009 : Can the immense volumes of gas uselessly burnt in the flares be valorized ?
20/12/2008 : How can the SPRATL concept triple the calorific energy of a combustible ?
15/09/2008 : How works a Stirling's engine and what to do ?
14/09/2008 : What are the agricultural stakes of the 21st century ?

10/08/2010 __________________________________________________________

SPRATL engine : The Stirling by SYCOMOREEN sent by Sycomoreen.

The SPRATL device is divided in a heated PRATL machine and another cooled PRATL machine ; a regenerator (RGN) joins the hot and cold machines in order to recover the thermal exchanges of the fluid which occur at the isochoric Vmin and Vmax steps.

Several similar Stirling's cycles simultaneously occur in all the other chambers. Thus, a 360° round of the SPRATL engine gives 6 complete Stirling's cycles. The isochoric steps are perfectly done, the isothermal evolutions are followed to best thanks to intense convections of fluid inside the SPRATL engine, and the regenerator (RGN) is recycling more than 95% of the thermal transfers between the isochoric step at Vmin and the one at Vmax.

The SPRATL engines are therefore compact and get radically new technical features TO MOVE TOWARDS THE CARNOT's THERMODYNAMIC OPTIMA, as well as a mechanical motor than as a receptor.

10/12/2009 __________________________________________________________

Used as a motor, a SPRATL engine will valorize any renewable source of heat :
   o The Sun with low temperature collectors or high temperature ones         o Thermal energy from the seas and oceans (TES)
   o Geothermics of surface (hydrothermal) or of depth (boring/mining)        o Wood, biogas or combustible organic wastes...

But also some fossile sources of heat (hydrocarbons : gas, coal, oil..., or nuclear energies) or vestigial heats coming from industries.

Used as a receptor, a SPRATL machine will be a freezer or a heating pump with high efficiency, respectively intended for the cold industry (even cryogenics with adapted fluids and materials) and for the heating of warehouses and dwellings.

14/05/2009 __________________________________________________________

The beginnings of the Concept of Stirling engine with Rotary Annular TriLobic à Pistons (SPRATL) were designed by SYCOMOREEN in november 2007. However, the machine with Rotary Annular TriLobic piston (PRATL machine) is an original invention of Pascal HA PHAM.    
Original trilobic Design of Pascal HA PHAM showed here with bi-arched gearings

In agreement with the Inventor, the rotary and bi-stacked features with unequal volumes of the PRATL machines have lead SYCOMOREEN to turn them into a radically new design : the SPRATL engines use the thermodynamic Stirling's cycle made of 2 isothermal evolutions (the one hot and the other one cold) linked with isochoric steps (the one of minimum volume Vmin, the other one with maximum volume Vmax). A SPRATL Patent (in French), property of Sycomoreen, and its figures 1,2,3,4,5 have been deposited at the Paris INPI in August
22th, 2008.

The Sycomoreen's works have put to the light the existence of theoretical polylobic versions with odd numbers (with 5, 7, 9... lobes). Nevertheless, the proposed Sycomoreen's configurations for the trilobic version bring all the improvements in order to well respect the Stirling's  cycle :
   o perfect achievement of the isochoric steps,
   o better follow-up of the isothermal evolutions by an intense convection of fluid inside the PRATL machines,
   o blocking of the direct thermal transfers between the hot and cold parts of a SPRATL engine,
   o regenerator with continuous crossed fluxes of fluid with rates of regeneration which are more than  95%. 

25/01/2009 __________________________________________________________

Flare on an offshore extracting plant of hydrocarbonsThe industrial oil process, notably the exploration of layers, but especially the extraction and the refinement of oil or gas, free directly in the atmosphere considerable quantities of methane (CH4) or dioxide of carbon (CO2 when gas is burnt).

According to the GGFR, in 2004 *, 150 billions 
of natural gas are annually burnt into the flares or are rejected in the atmosphere without any valorization;  either the equivalent of 30% of the European yearly consumption, or 25% of the one of the United States of America.

Flare on a hydrocarbons' refinement plant
One generally justifies these wastes by the lack of gas pipelines or electric grids near the sites of extraction. Even when the connection to the electric grid is possible, the cost of purchase and maintenance of the gas turbines / alternators is judged excessive. Nevertheless, this is a total waste of natural resources of high value, doubled by a major pollution with greenhouse effect gases among the most harmful (CO2 and CH4).

The trilobic engines of Pascal HA PHAM and the SYCOMOREEN's 
motors and pumps can answer these stakes, either by combustion and relaxation of gas in the trilobic engines, either by high output Stirling's cycle  in the SPRATL, to generate in situ electricity injected on the networks, possibly by submarine cables.

Whereas a gas turbine, all trilobic engines contains simple parts  (therefore little expensive to maintain and build ), have slow rotating motions and strong torque (no need of reducing gearings : direct coupling on the alternator) and start instantaneously in any position. Finally, they don't fear to be fed irregulary with gas.

N.B. : it could be foreseen a deferred electric production, either with a reserve of compressed air (possibly injected directly in the layer), either with a thermal storage block to sell electricity to peak hours on the grid. The generation of electricity in situ is the most applicable because the electric lines are generally in place, or relatively little costly to build compared to gas pipelines. Finally, electricity is the most effective shape of  energy : polyvalency, superfast transportation with weak losses.

* Since, the tendency is to the rise with the growth of the world gas marke, notably in Russia;     illustrations from Wikipedia's article

20/12/2008 __________________________________________________________

One generally sees, in order to heat or the dwellings, various solutions which oppose and even compete themselves briskly : electric heating, heating to oil, to gas, heating pumps, wood (logs, jagged or pellets...), the micro-cogeneration, etc...

Except of a solar thermal or wind bonus, to provide
efficiently an electric and heat autonomy to a dwelling or even a big building, there is actually only one optimal combination, that needs the discriminating use of these various solutions of heating :

Coupling of a heat/power cogeneration with a heating pump to heat the dwellings with SPRATL engine by SYCOMOREEN
The Stirling's combustibles : various and abundant, all organic garbage is useful

It requires :

1. To have a combustible* (wood, gas, fuel, organic or domestic garbages (cardboard, leaves, herbs and dry matters) ),
2. To be preferably linked to an electric network,
3. To use an heating pump and its thermal exchanger air/air or air/soil,
4. To put a cogenerating device to get simultaneously heat and power from the combustible, typically a Stirling's engine.

* Ideally, a non fossile fuel.

Some calculations easy to all

1. While starting from an 
initial quantity of heat QI supplied by the combustible, the Stirling cogenerator gives :
1.a) a electrical energy Wel = X . QI
1.b) a thermal residual 
low temperature (typically 60°C) energy  : QS = ( 1 - X ) . QI

2. The electrical energy Wel is injected, via the electrical network, to the heating pump which is working with a coefficient of performance (COP) : then it produces a thermal low temperature (60°C) energy  : QP = COP . Welec

3. Then, the heats QP and QS are directed inside the building to heat, which is receiving a thermal energy  QF = QS + QP at 60°C (therefore perfectly able to heat it at around 20°C).


As :    QS = (1 - X)  . QI      ;      Wel = X . QI      ;     QP = COP . Wel     ;     QF = QS + QP

QF = [ 1 + X . ( COP - 1 ) ] QI

The multiplicative factor of the calorific energy of the combustible is : M =  1 + X (COP - 1 ) so as QF = M . QI

Currently, with X = 20% and COP = 4,  it is worth  M = 1,6,
either 100 kg of combustible equivalent to 160 kg burned inside a traditional furnace.

At middle term, with the SPRATL, M = 2,2 is quite reachable (COP = 4, X = 40%).
either 100 kg of combustible equivalent to 220 kg burned inside a traditional furnace.
With the advantages of 2 coupled SPRATL engines* (a heating pump and a motor of Stirling),
one will reach ; X = 50% , COP = 5 and M =3 ,either 100 kg of combustible equivalent to 300 kg burned inside a traditional furnace.

 * SYCOMOREEN recalls here that its SPRATL engines can work as well in
Stirling's motor that in pump of heat.

15/09/2008 __________________________________________________________
Robert STIRLING 1790-1878The Stirling's engines are among the most effective and versatile devices to achieve some thermomechanical conversions. They use a mechanical source, a hot source and a cold source ; they can behave as well like motors, refrigerators and heating pumps. Equipped once with a heat regenerator, these are the only machines able to reach the ultimate thermodynamic efficiencies of Carnot, impassable in agreement with the second principle of the thermodynamics.

Their applications are essentially the generation of electricity, of cold or of hot, and they will probably be at the crossroads of the energizing conversions of the 3rd millennium, in particular in the setting of decentralized electric networks, that is to say where each user is soon a consumer, soon producer of energy. The sources of heat to promote are organic garbage, as plant garbage, the industrial garbage or cities' garbage (or possibly of the biogas/biofuel generated from this garbage), but also an inexhaustible, clean source, and in spite of everything nearly completely untapped:  the direct solar radiance. Thus the Stirling's engines appears an approach both economic and very respectful of the environment.

To know more about Stirling's technical world, SYCOMOREEN invites you to consult the website 

14/09/2008 __________________________________________________________
Sycomoreen invites you to read the radio broadcast Contre-Expertise of Radio France Culture
please wait a few minutes for the download (in French)
with :
- Christian Troubé ; Editor-in-chief of "La Vie"
- Gilles Hirzel ; Responsible for information, regional Office of the FAO for Europe
- Daniel Nahon ; Professor "émérite" at the "Institut universitaire de France", geochimist and petrologist of soils and the tropical changes
- Philippe Chalmin ; Professor of economy, specialist of the market of the raw materials, the founder of the "Cercle Cyclope"

To listen to the broadcast "Contre Expertise" (French)

It's about getting simultaneously :
- financial means,
- massive supply of soft water to increase the agricultural production in dry soils while limiting the weariness of the arable soils,
- the reduction of the worldwide poverty through a technological economic growth, then economic
- fuels extracted from biomass and clean energies.

Are these objectives really contradictory ? Not for the PHRSD with Stirling engines...

to contact us | nous contacter | um uns zu verständigen | para contactarse con nosotros
Le Mouvement Naturellement Energique !
The Naturally Energetic Movement !
Die Natürlich Energische Bewegung !
¡ El Movimiento Naturalmente Enérgico !
SYstems for COnversion of MOtions and REnewable ENergies
 Frequently asked questions   
Stirling's Engines with rotary annular trilobic pistons / Machines de Stirling à Pistons Rotatifs Annulaires TriLobiques (SPRATL)

Back to the FAQ's index