|
Application advantages could be as
precious as intrinsic engine ones.
Engine efficient is just the beginning of a saving cascade.
Quasiturbine offers optimum efficiency with a variety of fuels and modes.
Quasiturbine Efficiency
Where is the Energy Wasted?
Engines do not create energy, they only transform it
into mechanical energy with some inevitable losses. Physics imposes
thermodynamic losses to
energy transformation which cannot be circumvent, but engine losses
are more important than the minimum the physics is telling us...
In internal combustion engine, the energy is lost in
several ways. Vacuum intake of the gas engine is responsible for
about half of the gas consumption in today vehicle (hybrid concepts are
trying to harvest some of that, while detonation engine could eliminate
this loss). Inhomogeneous diesel fuel mixture is catastrophic to
combustion. Partial combustion in gas engine is also a lost.
Internal engine accessories like cam shaft and valve train are
reducing the net available engine power. Thermodynamic imperfect machine cycle is also
a substantial lost.
Lubrication friction is taking an other 3%. Scaling down engine is not
helping either...
Large utility plants convert energy more efficiently
than small distributed units and should be favored when possible. The
detonation Quasiturbine engine is one of the very few long term means to match
utility efficiency the distributed way, while being as chemistry clean as
possible.
Engine Exhaust Heat Recovery:
By placing a hot Quasiturbine into or around an engine exhaust pipe, and
injecting pressurized hot water (steam keep in the liquid state for better
heat transfer), some heat can be recovered into mechanical energy.
Stirling and short steam circuit Quasiturbine could do similarly!
Relative to the pressure flow energy conversion role
of the Quasiturbine, the efficiency (not an absolute efficiency) is given
by the (power or torque obtained) divided by the (power or torque which
could be obtained according to formula), which is typically between in the
80 % efficiency as of 2009.
A Cascade of Savings Engine efficiency is a large
domain of activity which extends far behind engines. The presence of an
engine in a vehicle adds accessories and weights which have to be carried
by the power of that same engine (the net usable power is reduced by the
presence of the engine itself). The presence of the engine is a necessity,
but also a factor of inefficiency. The ideal vehicle would not bother to
have an onboard engine! This shows that not only engine efficiency is
important on the bench test, but must also reduce to the minimum its
self-inefficiency in application. It would be worthless to have a 70%
efficiency gas engine for mobile application, if such a 30 HP engine would
weight 3 tons! This is one of the paradox of today hybrid vehicle concept:
How much additional equipment can be added to a vehicle to reach the
point where this equipment has worthless net saving effect in actual
application?
Because the Quasiturbine
reduces the weight of typical vehicle power train by over 50%, it does not
have to claim any extra efficiency on the test bench to be most valuable.
Such a reduction of weight on the lifetime of a vehicle means substantial
reduction in power demand, and consequently in fuel.
However, the Quasiturbine has several intrinsic efficiency characteristics
which add up, and reduce the engine energy lost in several ways:
- Because it does not have internal accessories to drive, like the
piston cam shaft and valve train, additional energy is available to the
end users.
- Because of the shaping of the volume pressure pulse, the
thermodynamic of the Quasiturbine can be far superior.
- Because the engine weight is about 1/4 that of a piston, energy
saving can be substantial in many applications.
- Because the Quasiturbine is a high torque low rpm engine, much less
or no transmission gears ratio are needed with corresponding efficiency
increase.
- Because the Quasiturbine can be of large size, it is an
efficient alternative to utilities for efficient energy conversion
(steam) in
electricity or from co-generation.
- Because the Quasiturbine (AC model with carriages) has the potential
to run in detonation mode, it will not have the low power penalty of the
Beau de Rocha (Otto) cycle, which can provide a 50% energy saving in
transportation application (much superior to hybrid concepts).
Multi-fuel capability is also an important efficiency factor permitting
to use the most pertinent local combustible. Hydrogen high compatibility
is also of consideration for the future.
Applications
Such small and efficient Quasiturbine steam engine makes mobility possible.
Thermal solar steam could drive a Quasiturbine. Solar concentrator could
directly heat up a Quasiturbine engine bloc, which would act as evaporator,
super-heater and motor! It could also be used for small geothermal or industrial heat process.
At home, combine electricity and heating would be possible from several
sources, sometimes with complementary higher temperature source.
Quasiturbine Stirling could be made cylindrical and be inserted directly into
the chimney for optimum heat recovery.
Engine Exhaust Heat Recovery:
By placing a hot Quasiturbine into or around an engine exhaust pipe, and
injecting pressurized hot water (steam keep in the liquid state for better heat
transfer), some heat can be recovered into mechanical energy. Stirling and short
steam circuit Quasiturbine could do similarly! Same technology could apply to:
Industrial exhaust gases heat recovery
industrial furnace heat recovery
Industrial process heat recovery
Chimney or stack heat recovery
Waste heat recovery
Solar heat recovery
Geothermal heat recovery
Thermal nuclear heat
ORC (Organic Rankine Cycle)
Engine suitable for ORC (Organic Rankine Cycle) in Solar, Geothermal and Waste
Heat Recovery.
Efficient at All Loads
The benefit of power modulation is precious. Pneumatic, steam or
combustion turbine engines all have one major limitation: Their efficiency
depends of the load, the rpm, the power... They have to be operated at
their design condition to meet their optimum efficiency at a given working
power. Because the Quasiturbine is not an aero- or hydro- dynamic engine,
but a static pressure type of engine, it has an optimum efficiency on a
large range of power, load and rpm. This allows for efficient uses in power
modulation applications with optimum energy saving and efficiency. The
Quasiturbine is consequently a superior gas expander and most suitable for
efficiency difficult steam co-generation projects.
Piston Beau de Rocha (Otto) gas engine and the diesel engine have
similar optimum power regime limitation. Only the detonation engine has
not.
Quasiturbine as an Immediate Solution
Engines are at the end of the energy chain and they affect the most the
energy users. More efficient engines not only save fuel, but any bit of
saving has direct
amplified impacts on all anterior stages of the energy cascade and
industry.
Click here for a 2000 pixels
high resolution image
The Quasiturbine in Beau de Rocha (Otto)
cycle is a relatively simple technology which could be widely used within
a few years with substantial efficiency benefits over the piston engines
in many applications. Other claimed
advantages include high torque at low rpm, combustion of hydrogen and
compatibility with detonation mode. A lot of research are going on to increase the
efficiency on the long term with piston, hydrogen, fuel cell... Hybrid
concepts are ways to harvest part of the "low power efficiency penalty" of
the piston engine used in vehicle, but counter-productive measures limit
the long term perspective until they could efficiently fuel from the
electrical grid. None of these solutions are short term stable and
competitive. By opposition to dozens of new engine designs, the most important at this
time about the Quasiturbine is not the actual machine, but the fact that
it does unknot a new field of development and offers means to achieve what
no other engine design has suggested or is able to, and specially for
detonation where piston engine has failed for over 40 years...
Efficiency as Rotary Expander
Gas Pipeline Pressure Energy Recovery - Rotary Pressure Expander
What about an "energy recovery rotary pressure regulator" ? An
interesting application of the pneumatic Quasiturbine is to recover the
pipeline high pressure energy at local distribution stations. Instead of
using a conventional pressure regulator (an energy dissipative device), a
pneumatic Quasiturbine will rotate under the pressure differential and the
flow will be controlled by the rpm, i.e. the torque applied on the
Quasiturbine shaft. It does act as a dynamic active rotary valve. This
way, the Quasiturbine can transform the pressure differential into useful
mechanical work to run pump, compressor, ventilator, electricity generator or locally convert the energy in high
grade heat (better than pre-heating the gas before that
same "rotary expander", to avoid any residual condensation as done with conventional regulators).
Substantial heat is now given to conventional expansion valve in pure
lost, while heat given to the gas at the intake of a rotary expander is
essentially all recovered in mechanical energy or electricity. Because conventional turbines can not be widely
modulated in rpm and load, they are not suitable for gas flow and pressure
control, while the Quasiturbine is essentially a closed valve at zero rpm,
and has high efficiency at all torque and all flow rpm. With such a system, any heat added before the
Quasiturbine expands the gas and increases the available volumetric flow
with the result that this heat is converted in mechanical energy with a
very high efficiency. All experimental demonstration has to be done only by gas
experts and under all current rules and regulations. Ignoring gas
expansion and considering only the gas pressure flow, a 36 inches diam.
gas pipeline at 700 psi carry typically a pressure power in excess of 30
MW - 25 millions of pound-ft/sec - of zero pollution pure mechanical
energy almost totally recoverable through Quasiturbines in the heart of
cities and industrial parks. This is tens of giant windmills on kW-h basis!.
A survey (M. Dehli, GWF Gas-Erdgas 137/4, p.196, 1996) showed that in
Germany alone, the potential for utilizing this pressure in 1996 was
200-700 MW, and the gas consumption has increased since then... See the
conceptual diagram and a
pipeline technical paper.
Economics: Take any similar fossil fuel electric generation station, and
set the fuel cost to zero, as the pressure energy recovery does not consume any
fuel. It is even better than renewable, it is free energy, until the utilities
start to charge for it, and make an easy extra income!
Refrigeration: Conventional pressure regulators make all the gas to
expand from the constant high pressure side, and the gas pressure-kinetic energy
at the needle is converted into undesirable heat, reducing accordingly the
amount of cold produced. The Quasiturbine rotary expander allow for individual
chamber to expand at a variable reduced pressure during expansion, and such
reduces the gas kinetic energy transformation into destructive heat.
Furthermore, the Quasiturbine recuperates mechanically the gas differential
pressure energy, which can be used to run more compressors and make more cold...
A double energy efficiency gains! A single Quasiturbine in tubo-pump (tubo-compressor)
mode could have one circuit used as rotary expander while the other is used to compress back some of the expanded gas. This offers great enhancement of thermodynamic
cooling machine, and specially in high power LNG - Liquid Natural Gas
liquefaction stations. Of course, this efficiency enhancement is also available
for more modest cooling system and air conditioning equipments. With
Quasiturbine rotary expander, the efficiency of a gaseous only (like dry
air) system reaches almost the efficiency of a phase change liquid-gaseous
system, and
sophisticated phase change chemical products often environmentally unwelcome are
not anymore needed.
More Technical
www.quasiturbine.www/QTperformance.html
Quasiturbine Rotary Expander
Intake cut off valve
|
