: 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 ?
WORKS A SPRATL ENGINE AND WHAT ARE THE ADVANTAGES
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.
ARE THE FIELDS OF APPLICATION OF A SPRATL ENGINE
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.
ARE THE GENESIS AND THE MAIN IDEAS OF THE SPRATL CONCEPT
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
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
been deposited at the Paris INPI in August 22th,
The Sycomoreen's works have put to the light the existence of
theoretical polylobic versions with odd numbers (with 5, 7,
lobes). Nevertheless, the proposed
Sycomoreen's configurations for the trilobic version bring
all the improvements in order to well respect the Stirling's
o perfect achievement of the isochoric
o better follow-up of the
isothermal evolutions by an intense convection of fluid inside the
o blocking of the direct thermal
transfers between the hot and cold parts of a SPRATL engine,
with continuous crossed fluxes of fluid with rates of regeneration
which are more than 95%.
THE IMMENSE VOLUMES OF GAS USELESSLY BURNT IN THE FLARES BE
The 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
According to the GGFR,
in 2004 *, 150
billions m³ 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
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).
a gas turbine, all trilobic
engines contains simple parts
expensive to maintain and build ),
have slow rotating
motions and strong torque (no need of reducing gearings : direct coupling on the alternator)
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
CAN THE SPRATL
TRIPLE THE CALORIFIC ENERGY OF A COMBUSTIBLE ?
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
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
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
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).
QS = (1 - X) . QI
; Wel =
X . QI
; QP = COP . Wel
= 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 .
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.
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.
* SYCOMOREEN recalls here that
its SPRATL engines can work as well in Stirling's motor that in pump of heat.
STIRLING's ENGINE AND WHAT TO DO ?
among the most effective and versatile devices to
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.
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
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 www.moteurstirling.com
AGRICULTURAL STAKES OF THE 21st CENTURY ?
Sycomoreen invites you to read the radio broadcast Contre-Expertise
France Culture please
wait a few minutes for the download (in French)
- 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
France", geochimist and petrologist of soils and the tropical
- Philippe Chalmin
; Professor of economy, specialist of the market of the raw materials,
the founder of the "Cercle Cyclope"
about getting simultaneously :
- financial means,
- massive supply of soft water to increase the agricultural
production in dry soils while limiting the weariness of the
- the reduction of the worldwide poverty through a technological
economic growth, then economic,
- fuels extracted from biomass and clean energies.