U.S. patent application number 09/982686 was filed with the patent office on 2003-01-09 for internal combustion engine energy extraction devices.
Invention is credited to Wilson, Benjamin Raymond.
Application Number | 20030005696 09/982686 |
Document ID | / |
Family ID | 26933860 |
Filed Date | 2003-01-09 |
United States Patent
Application |
20030005696 |
Kind Code |
A1 |
Wilson, Benjamin Raymond |
January 9, 2003 |
Internal combustion engine energy extraction devices
Abstract
The "Internal Combustion Engine Energy Extractor" is a device
that is extracts otherwise wasted heat from both the engine exhaust
system and it's cooling system. This heat is converted into
mechanical energy, which is 1) used to power the "Extractor" and 2)
may be used for auxiliary engine devices, such as an intake air
supercharger or an electrical generator. The Energy Extractor by
itself 1) increases engine efficiency and power by decreasing
exhaust back pressure and 2) decreases engine wear by decreasing
the cylinder and engine temperature.
Inventors: |
Wilson, Benjamin Raymond;
(Salem, OR) |
Correspondence
Address: |
BENJAMIN RAYMOND WILSON
SUITE 290
700 BELLEVUE STREET
SALEM
OR
97301
US
|
Family ID: |
26933860 |
Appl. No.: |
09/982686 |
Filed: |
October 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60240959 |
Oct 18, 2000 |
|
|
|
Current U.S.
Class: |
60/618 |
Current CPC
Class: |
F01N 5/02 20130101; Y02T
10/144 20130101; Y02T 10/12 20130101; F01K 23/065 20130101; F02B
37/00 20130101; Y02T 10/16 20130101; F01K 21/04 20130101 |
Class at
Publication: |
60/618 |
International
Class: |
F01K 023/10 |
Claims
What I claim for my invention is:
1. The Coolant Based Energy Extractor implementation. (See FIG.
1)
2. The Exhaust based Energy Extractor Implementation (see FIG.
2).
3. The Combination Energy Extractor Implementation (see FIG.
3).
4. The Gas Mix Energy Extractor (see FIG. 4).
5. The Exhaust Boiler Energy Extractor (see FIG. 5).
6. The Rankine Exhaust Energy Extractor (see FIG. 6).
7. The Steam Injector Energy Extractor (see FIG. 7).
Description
[0001] Reference: Provisional Patent Application 60/240,959
BACKGROUND OF INVENTION
[0002] It is well known that the efficiency of internal combustion
engines ranges between 25% and 40%. Spark ignition engines ("gas
engines") will have efficiencies between 25% and 35%, while
compression ignition engines ("diesel engines") will have
efficiencies between 30% and 40%.
[0003] The portion of the fuel that is not converted into
mechanical energy will be converted into excess heat and dissipated
either by the cooling system (roughly one-half of the heat) or
expelled into the environment in the form of hot exhaust gas
(roughly the other half of the heat). A smaller amount of heat will
be loss via convection from the engine itself. The proportion of
the energy dissipated by the various routes varies with the type of
engine and the type of cooling system employed.
[0004] Since shortly after the birth of the internal combustion
engine attempts have been made to improve the efficiency of the
internal combustion engine by recovering some of the dissipated
heat and converting it into mechanical energy. The first patent on
such a device was awarded in 1882; since then some 200 patents on a
variety of inventions of this type have been awarded. None have
functioned well enough to enjoy commercial success.
[0005] While some devices do provide a slight increase in internal
combustion engine efficiency, all possess significant drawbacks.
Some devices will cause the internal combustion engine to overheat
and will shorten engine life; many devices will increase the cost
of the engine far in excess of the economy gained from fuel
savings, and most devices will not perform according to the claims
of the patent.
[0006] The "Energy Extractor", as described in this patent
application, incorporates a new and unique approach to recover heat
energy from the internal combustion engine which results in a
significant increase in engine efficiency. The device reduces the
operating temperature of the engine and will prolong engine life.
Energy Extractor technology, which may be implemented using readily
available engine components, would increase the construction cost
of an engine by only ten or twenty percent.
BRIEF SUMMARY OF INVENTION
[0007] Capsule Summary:
[0008] The "Energy Extractor" uses excess engine heat that is
normally dissipated into the environment to produce steam. The
steam powers a steam turbine: the turbine, in turn, drives a
suction Pump which is used to suck the exhaust out of the cylinder
when the exhaust valve is open. This increases the engine
efficiency and also results in a greater amount of heat energy
being recovered than would otherwise be possible. Power from the
turbine may also be used for other devices. A second suction pump
can be used to extract steam from the cooling system which may be
superheated and used to Power auxiliary devices.
[0009] The "Energy Extractor" does just what the name implies; it
extracts energy from the internal combustion engine. The extraction
is done in two ways; 1) a "vacuum pump" is used to literally suck
the exhaust out of the cylinders when the exhaust valve opens and
2) a second "vacuum pump" may be used to extract vapor from the
engine coolant system. The heat energy present in the extracted
exhaust and coolant vapor may then be converted to mechanical
energy using a thermodynamic cycle, such as the Rankine cycle.
[0010] The "vacuum pumps" described here may be fabricated using
the compressor sections of a typical turbocharger.
[0011] The "vacuum pumps" utilized by the "Energy Extractor" have
the effect of lowering the pressure and temperature of 1) the
cylinder in the exhaust phase and 2) the coolant system. The
advantages of a lowered exhaust pressure and temperature are
readily apparent; a) less mechanical work is required by the engine
to expel exhaust gas from the cylinder, and b) lower temperatures
in the exhaust system will lead to longer component life.
[0012] There is also a more subtle advantage to exhaust evacuation;
as exhaust is aspirated from the cylinder, the temperature of the
remaining gas in the cylinder drops. The lower of the temperature
of the residual gas, the less amount of heat will be transferred to
the cylinder walls and coolant system, and more heat will be
transferred to the exhaust gas that is aspirated. The heat that is
recovered from the exhaust system is high quality heat; i.e., the
temperature is quite high and the amount of energy available for
conversion to mechanical work is high. In contrast, the heat that
may recovered from coolant system is "low quality" heat; the
temperature is low, and the energy available for conversion to
mechanical work is low. Thus more energy is made available as "high
quality heat"--from the exhaust--as opposed to "low quality
heat"--from the cooling system. This is in direct contrast to a
normal turbocharger, in which increased pressure and temperature in
the exhaust system converts "high quality heat" into "low quality
heat" in the cooling system.
DESCRIPTION OF DRAWINGS
[0013] FIG. 1: Coolant based Energy Extractor; Drawing of the
manner in which steam is aspirated from the engine cooling system
and then superheated to drive sequential steam turbines.
[0014] FIG. 2: Exhaust based Energy Extractor; Drawing
demonstrating the manner in which the Energy Extractor can be used
without involving a engine water cooling system.
[0015] FIG. 3: Combined Energy Extractor: Drawing demonstrating the
manner in which the coolant based and exhaust based systems may be
combined.
[0016] FIG. 4: Gas Mix Energy Extractor: Technique in which steam
from an engine cooling system is combined with exhaust gas in to
provide the "charge" that is used to drive a turbine after
superheating.
[0017] FIG. 5: Exhaust Boiler Energy Extractor: Simplified system
for exhaust evacuation; requires a constant supply of water,
however.
[0018] FIG. 6: Rankine Exhaust Energy Extractor: System using a
Rankine Steam Cycle to recover exhaust heat and power an exhaust
evacuator.
[0019] FIG. 7: Steam Injection Energy Extractor: Another technique
for recovering exhaust heat. In this technique steam produced by
steam heat is injected into a turbocharger to speed up the exhaust
turbine and decrease the amount of exhaust back pressure.
SPECIFIC DETAILS ON ENERGY EXTRACTOR OPERATION
[0020]
1 Specific Details on Energy Extractor Operation As the name
implies, the Energy Extractor actively removes heat from the
engine. Heat energy is extracted from the cooling system and from
the exhaust system. This heat energy is then converted to
mechanical energy to 1) power the extraction process, 2) provide
energy for supercharging the intake manifold, and 3) provide power
for other uses. The energy extraction process itself results in
cooler engine operation and increased fuel efficiency. 1
[0021] As the name implies, the Energy Extractor actively removes
heat from the engine. Heat energy is extracted from the cooling
system and from the exhaust system. This heat energy is then
converted to mechanical energy to 1) power the extraction process,
2) provide energy for supercharging the intake manifold, and 3)
provide power for other uses. The energy extraction process itself
results in cooler engine operation and increased fuel
efficiency.
[0022] The Energy Extractor produces mechanical energy in two
forms:
[0023] 1. The energy extractor aspirates exhaust gas from the
engine cylinders. Instead of a positive pressure, the exhaust
manifold will develop a partial vacuum. Instead of pistons forcing
exhaust gas out against back pressure from the exhaust valves, the
exhaust manifold, a turbocharger turbine, the catalytic converter,
the muffler, and exhaust pipe, the exhaust gas will literally be
sucked out of the engine. The engine no longer uses energy to
function as an air pump.
[0024] 2. The energy extractor also aspirates steam from the engine
cooling system. This ensures excellent engine cooling, and provides
steam vapor for superheating from exhaust manifold heat.
[0025] 3. The energy extractor uses exhaust heat to pressurize both
the exhaust gas and the steam to drive small turbines. This is
similar to the manner in which a jet engine pressurizes air in the
combustion chamber and forces it out through a turbine. This
pressurized gas or steam can be used to:
[0026] a. Power a turbine that pressurizes the intake manifold air,
i.e., provide the energy for a supercharger. Note that while this
would superficially resemble a turbocharger, the source of the
energy to compress the incoming air would be coming from the energy
extractor and not from the pressure of the exhaust manifold, which
would be under a vacuum.
[0027] b. Power a turbine that propels a belt drive replacing the
normal crankshaft driven belt drive in an engine.
[0028] c. Power a turbine that is connected to and augments that
drive shaft. This is superficially similar to the use of "exhaust
turbines" in many patents over the past thirty years.
[0029] It may be useful to review the operation of a gas turbine
(jet engine) to help understand the operation of the Energy
Extractor. Understanding the operation of a jet turbine is
absolutely essential to understanding the operation of either the
coolant or exhaust based systems.
[0030] The basic jet turbine is actually a very simple engine. It
consists of essentially three parts; a compressor, a combustion
chamber, and a turbine. The operation is relatively simple:
[0031] 1. Air that enters the engine is compressed (by the
compressor, naturally) to a pressure of 300400 pounds per square
inch. As the gas is compressed the temperature rises to over 10000
Fahrenheit.
[0032] 2. As the heated gas enters the combustion chamber it is
mixed with jet fuel and spontaneous combustion occurs. The volume
of the combustion chamber is greater then the volume of the
compressor, and a constant pressure volume expansion of the
combustion mixture occurs. Temperatures at this point may be well
over 3000.degree. F.
[0033] 3. The mixture is then expelled through the turbine stage.
As the hot, pressurized gas rushes out it turns the blades of the
turbine and produces rotational energy. The turbine then provides
power to the compressor via the turbine shaft. A second shaft that
exits out the back can be used to power various accessories. If the
shaft is connected to a propeller, the engine is referred to as a
turboprop. If it is connected to a helicopter rotor, it is known as
a turboshaft engine.
[0034] There are two observations about jet engines that are
essential to the understanding of the Energy Extractor. The first
is this:
[0035] The Sole Function of the Duel is to Add Heat Energy to the
Combustion Chamber.
[0036] It would be possible, though certainly impractical, to
operate a jet turbine with electrical heating elements. This could
be done by placing heating elements in the combustion chamber and
heating the air from the compressor with electricity instead of
burning petroleum products. It would also be possible, but wildly
impractical and dangerous, to heat the air in the combustion
chamber with nuclear energy, such as by controlled fission. In
neither of these cases would actual petroleum fuel be required.
[0037] The second vital observation about jet engines is:
[0038] If the Combustion Chamber does not Require Oxygen, then the
Jet Engine could Operate in any Gaseous Environment.
[0039] The previously mentioned mythical electric and nuclear
turbines could operate in a nitrogen, carbon dioxide, or neon
atmosphere. Since the heat added to the combustion chamber comes
from either the electrical elements or a nuclear reaction, there
would be no need to have oxygen in the compressed atmosphere.
Here's the important point; the engine could also operate with an
air intake consisting of exhaust from an internal combustion engine
or with steam from a boiler.
[0040] The final piece, missing so far, is the heat source for the
combustion chamber. A very hot, reliable, and cheap source is
readily available for the Energy Extractor. It is heat extracted
from the exhaust system. This heat is supplied to the "combustion
chamber" in two ways. First, there is an exhaust
manifold/pressurization chamber heat exchanger. Second, exhaust
heat is pumped into the chamber by the action of the
compressor.
[0041] For purposes of further discussion, it may be helpful to
visualize the coolant based Energy Extractor as a jet turbine
engine that runs in a steam atmosphere. It sucks this steam out of
the engine cooling system and heats it in the combustion chamber
with heat from the exhaust system. The steam is expelled through a
turbine, which operates the compressor and is routed to the
radiator, which acts as a condenser.
[0042] The exhaust based Energy Extractor may be regarded as a jet
turbine that sucks exhaust out of the engine and through a heat
exchanger. The cooled exhaust gas is pumped into the combustion
chamber and reheated with the heat from the heat exchanger. The
reheated gas is routed through the EE exhaust turbine and then
expelled to the environment.
[0043] Mechanical energy may be recovered from the turbine shafts
of both of these "jet turbines." It is also possible to add a
freewheeling exhaust turbine, much in the same manner that a
turboshaft is powered by a jet turbine.
[0044] The energy extractors literally do what their name implies;
they extract energy from both the exhaust and coolant systems.
Exhaust is literally aspirated from the piston cylinder when the
exhaust valve opens, with "exhaust back pressure" becoming "exhaust
back vacuum".
[0045] Likewise, heat in the form of vapor is aspirated from the
engine cooling system. The heat recovered in this manner is
converted to mechanical energy by use of a turbine which 1) drives
the "aspirators," and 2) provides power to engine accessories.
[0046] Both of these aspirating actions results in lower engine
operating temperatures and maximum recovery of engine waste
heat.
[0047] At this point it should be noted that for forty or fifty
years there has been a large market for devices that decrease
exhaust back-pressure. The astute reader will, of course, recognize
that I am referring to exhaust headers. There is good reason for
this; mechanical engineering textbooks estimate that for increase
in back-pressure of one psi there will be a decrease in gas mileage
of two percent. Any device that decreases back-pressure will
increase gas mileage.
[0048] At this point there are probably some thoughtful readers who
are pondering the balance sheet associated with equipping an
internal combustion engine with even a modest jet turbine or two.
The starting price for the smallest commercially available new jet
engine has been somewhere around $40,000. Bolting one on the side
of even a good size Diesel engine will likely produce significant
sticker shock on the part of most buyers.
[0049] Fortunately, there is a readily available work-around to
this monetary problem. A normal turbocharger can be converted into
a small gas-turbine by adding a combustion chamber connecting its
compressor and exhaust turbine sections. And as the reader is
undoubtedly well aware, new turbochargers for either cars or large
trucks may be purchased retail starting for around $500.
[0050] With the concept of the non-fuel jet turbine firmly in mind,
let's look at the individual parts of the Energy Extractor. For
accuracy and convenience we will give new names to the parts of the
"turbine". Depending upon the implementation, the compressor will
be renamed either the exhaust evacuator or the charge aspirator.
The combustion chamber will be dubbed either the exhaust
pressurization chamber or the coolant pressurization chamber. The
turbine will be referred to as the EE exhaust turbine or the EE
coolant turbine.
[0051] Although the Energy Extractor has a variety of
implementations, the basic building blocks consist of the following
components:
[0052] Basic Components:
[0053] 1. An exhaust chamber
[0054] 2. An exhaust evacuator
[0055] 3. A charge aspirator
[0056] 4. An evaporation chamber
[0057] 5. A pressurization chamber
[0058] 6. An EE power turbine
[0059] Depictions of the various connections between the components
will be found in FIGS. 1, 2, 3, and 4.
[0060] 1. Exhaust Chamber:
[0061] The exhaust gas will go to a one or two-stage exhaust
chamber upon exiting the exhaust valves. The chamber is mounted to
the engine heads in the same manner as an exhaust manifold and
contains either one or two heat exchangers.
[0062] The first stage of the heat exchanger transfers heat to the
exhaust pressurization chamber (5e) or the coolant pressurization
chamber (5c). The chamber functions similarly in both the exhaust
and coolant implementations. The pressurization chamber is
analogous to a combustion chamber in a turbine engine, in that
thermal energy is added to the gas that is delivered from the
compressor stage. This stage of the exchanger drops the temperature
of the exhaust gas to 300.degree.-400.degree. F.
[0063] Since there is a temperature drop of
600.degree.-1600.degree. F. across the heat exchanger, there will
be a corresponding decrease in the volume and pressure of the
exhaust gas--although not in the mass of the gas. This decrease in
volume and pressure will contribute partially to the chamber
operating in a partial vacuum.
[0064] In an ignition combustion engine (gas) engine under load,
the temperature of the exhaust gas at this stage is normally about
1600.degree.-1800.degree. Fahrenheit. The exhaust temperature of a
compression combustion (diesel) engine under load will only be
about 800.degree. Fahrenheit; however, because the diesel engine
does not "throttle" the intake air the exhaust gas will have
greater mass. With this in consideration, it can be seen that the
heat content of the diesel exhaust, while perhaps not as great as a
corresponding ignition exhaust, will certainly be greater than what
exhaust gas temperatures would suggest.
[0065] An appropriate question to ask at this point is "How big do
the primary and secondary heat exchangers have to be?" The answer
may be a bit surprising, and can be roughly approximated from
observations about heat dissipation in the cooling system.
[0066] As previously noted, at full load about one third of the
energy of the fuel is converted to mechanical motion, one third is
converted to heat and exhausted out the tailpipe, and the remaining
one-third is dissipated as heat through the cooling system. As a
rough approximation it can be seen that the amount of heat expelled
in exhaust gas is about equal to the amount of heat dissipated
through the radiator.
[0067] Under normal conditions the maximal coolant system
temperature will be about 220.degree. Fahrenheit. The highest
ambient temperature will be no more than 120.degree. F. Therefore,
the minimal temperature gradient across which the radiator heat
exchanger will operate is (220-120)=100.degree. Fahrenheit.
[0068] In contrast, the exhaust chamber primary heat exchanger will
be transferring heat across a temperature gradient that will be
400.degree. F. at the absolute minimum and may be much higher. With
a gradient of 400.degree. F., only one-fourth as much heat
exchanger surface area will be needed to transfer the same amount
of heat. Thus, the size of the exhaust chamber heat exchanger will
only need to be about one-fourth the size of the cooling system
radiator.
[0069] A second stage heat exchanger may or may not be used,
depending upon the particular embodiment. Various options will be
discussed in a later section; for the time being, we will discuss
the "air-charged" option.
[0070] 2. Exhaust Evacuator:
[0071] Another description of this stage might be the "exhaust heat
pump," inasmuch as it pumps hot exhaust gas from the cylinder (when
the exhaust valve is open) and exhaust gas passages. It will
generally consist of a centrifugal compressor much like that used
in the compressor section of a turbocharger. The evacuator may, but
does not necessarily have to be powered by the EE exhaust turbine.
It may aspirate exhaust gas directly from the engine, or may
aspirates the gas from the exhaust chamber after it has traversed
the primary and secondary heat exchanger. Depending on the
implementation, it either pumps it into the exhaust pressurization
chamber (preferred implementation), through a secondary or tertiary
heat exchanger, or expels the gas to the exhaust system.
[0072] The presence of a relative negative pressure at the inlet of
the exhaust evacuator causes a drop in the temperature of the gas
in the exhaust chamber. The relative positive pressure at the
outlet of the exhaust aspirator causes a rise in the temperature of
the gas in the pressurization chamber. In this manner exhaust gas
and heat is pumped from the exhaust chamber to the pressurization
chamber, where it can be used without increasing exhaust back
pressure.
[0073] Several questions may be posed at this point. The first
would be "how big does the exhaust evacuator have to be?" The
approximate answer to this may be obtained merely by observation of
a problem that has plagued small aircraft pilots for years.
[0074] The phenomena of carburetor icing is well understood and
feared by piston aircraft pilots. The condition results because the
piston engine aspirates air through the carburetor and intake
manifold. This action causes a partial vacuum in the manifold.
[0075] As air rushes through the carburetor to fill the vacuum it
expands and its pressure decreases. As the pressure decreases, the
temperature of the air decreases. If there is water vapor present,
it is possible for the temperature drop enough to actually cause
vapor to condense and then to freeze on the carburetor passage way.
As the ice accumulates it may choke off the carburetor and cause
engine failure.
[0076] Most piston engine aircraft with carburetors will have a
special control marked carburetor heat. When this is activated air
heated by the engine is diverted through the carburetor to melt the
ice. In spite of this, there are a number of small aircraft
accidents each year from engine failure due to carburetor
icing.
[0077] In this particular situation it is the engine acting as an
air pump that produces the partial vacuum in the manifold and
resultant drop in temperature. It should be noted, however, that
the typical turbocharger can pump far more air than the pistons are
able to aspirate; the result is that the intake manifold is under
pressure instead of under a vacuum.
[0078] An exhaust evacuator with perhaps twice the capacity of a
turbocharger that normally accompanies an engine should be able to
evacuate enough exhaust to produce a marked decrease in pressure
and temperature.
[0079] 3. Charge Aspirator:
[0080] Depending upon the type of "charge" that the Energy
Extractor uses, this aspirator pumps either air, steam from a
coolant water evaporation chamber, or an air/alcohol mixture from
the second stage heat exchanger of the exhaust chamber. The charge
is then ported to the pressurization chamber.
[0081] Similar to the exhaust aspirator, the charge aspirator may
be driven by the EE coolant turbine, although it certainly could be
powered by another source. The easiest implementation using a
turbine could be done using a separate turbocharger with a turbine
and compressor. The simplest implementation would involve a single
turbine that powers both the exhaust evacuator and the charge
aspirator.
[0082] 4. Evaporation Chamber:
[0083] The evaporation chamber partially takes the place of the
cooling system radiator. It may based upon either a nozzle design
or a heat exchanger design. The charge aspirator places the
evaporation chamber under a partial vacuum, which decreases the
boiling point of water. The steam (or working liquid) aspirated
from the evaporation chamber is routed to the coolant
pressurization chamber, where it is heated by the primary heat
exchanger.
[0084] Nozzle Based Design:
[0085] It is well known that water that boils in cooling system
water passages will compromise the absorption of heat from the
water passage walls. This is because steam, with its greatly
diminished density, will not absorb heat as efficiently as liquid
water.
[0086] Because of this, water that is routed to the evaporation
chamber from the engine will be fed into the chamber via pressure
reduction nozzles. This will have two effects; it will keep the
pressure of the water in the engine water passages significantly
higher than the pressure in the evaporation chamber, which will
prevent water vaporization boiling in the engine. With this design,
there will be no need to redesign an engine's coolant passages.
Secondly, the use of a water nozzle with an appropriate spray
pattern will facilitate evaporation and cooling and minimize the
sometime violent action of boiling water.
[0087] It should be noted that the water pump will require
additional power to pump the water through the evaporation nozzles.
However, at least a part of this power will be recovered in the
form of the extra water vaporized by the nozzle action.
[0088] Heat Exchanger Design:
[0089] Instead of using a common working liquid for both engine
cooling and operation of a "thermodynamic engine," it is possible
to use separate circuits which exchange heat through an evaporation
chamber heat exchanger. With this design engine coolant would
circulate through the engine and a heat exchanger which would
function like a typical engine radiator. Instead of transferring
heat to air, the heat would be transferred to a "working liquid" to
power the thermodynamic engine. The working liquid in the
evaporation chamber would also be placed under a partial vacuum by
the charge aspirator. Like the nozzle based design, the charge
aspirator would prevent "heat reflection" from the vapor
superheater and would facilitate working liquid evaporation by
lowering the vaporization temperature with the partial vacuum. Also
like the nozzle based design, the charge aspirator will pump the
vaporized working liquid into the coolant pressurization chamber.
While the working liquid may be a water/coolant mixture, other
liquids could be used, such as an ammonia/water mixture or a
refrigerant.
[0090] 5. Pressurization Chamber:
[0091] This is somewhat analogous to the combustion chamber of a
jet engine. Mixing and heating of the various gases occur,
depending upon the Energy Extractor implementation. As the mixture
absorbs heat from the primary heat exchanger the effective volume
of the gas increases, forcing it through the associated EE
turbine.
[0092] For the coolant based implementation (5c), the only gas
introduced into the pressurization chamber is steam aspirated from
the evaporation chamber. After heating and pressurization, the
steam is ported to the EE coolant turbine, possibly to a power
turbine, and then to the condenser, or radiator.
[0093] For the exhaust based implementation (5e), the cooled
exhaust gas and possibly a second cooling charge is ported into the
chamber and then ported to the EE exhaust turbine and then to the
environment.
[0094] 6. Energy Extractor (EE) Turbine Section:
[0095] This is analogous to the turbine on a jet engine or a
turbocharger. It may be either axial or centrifugal, although the
most common configuration will probably be centrifugal like the
typical turbocharger turbine. The energy extractor turbine will
receive steam from the coolant pressurization chamber (5c) or hot
gas from the exhaust pressurization chamber (5e). The turbine will
extract a portion of the kinetic energy from the exhaust/steam
mixture and turn a shaft to power the exhaust or steam aspirator
sections. Following its exit from the Energy Extractor turbine, the
gas/steam mixture could be routed through a power turbine
section.
[0096] One significant difference between the Energy Extractor
turbine and the turbine on a jet engine or turbocharger is the
working temperatures the unit encounters. The EE turbine will work
at much lower temperatures. Temperatures will probably not exceed
800.degree. F. for the exhaust turbine and 300.degree. F. for the
coolant turbine. With less thermal stress, closer tolerances should
be possible than for a jet turbine or turbocharger.
[0097] 7. Power Turbine.
[0098] This would be analogous to the "free turbine" in a jet
engine which provides power to either a propeller or a turboshaft.
It is used to recover excess pressure power not utilized by the EE
turbine. A typical application would be a turbocharger or an
exhaust turbine. The turbocharger would return energy to the engine
by pressurization of the air going to the intake manifold. An
exhaust turbine setup could power an auxiliary generator or
directly return power to the crankshaft through some type of
coupling apparatus.
Energy Extractor Arrangements
[0099] The various Energy Extractor components may be assembled in
a variety of arrangements. All of these arrangements have several
common features; 1) an exhaust evacuator is used to aspirate
exhaust gas from an exhaust heat exchanger and/or from the engine,
2) exhaust heat is used to power the exhaust evacuator using
various techniques. In general, the more complex the system, the
greater the energy recovery that may be expected.
[0100] Coolant Based System:
[0101] Please refer to FIG. #1. The coolant based Energy Extractor
functions as follows:
[0102] 1. Coolant (most likely water and antifreeze) is pumped from
a coolant reservoir through the engine coolant jacket. Leaving the
cooling jacket, it is routed to the evaporation chamber (4). Note
that this is a nozzle based evaporation chamber. The water/coolant
mixture is introduced into the chamber through spray nozzles, which
has the effect of a) keeping the coolant jacket pressure higher
than that in the evaporation chamber, and b) facilitating
evaporation by the use of a spray. The high pressure of the coolant
in the engine jacket prevents localized coolant boiling with its
attendant heating problems.
[0103] 2. Evaporation is driven by the charge aspirator (3), which
sucks coolant vapor out of the evaporation chamber and into the
coolant pressurization chamber (5C). The vaporization causes
cooling of the remaining coolant, which drains into a
reservoir.
[0104] 3. The vapor pumped into the coolant pressurization chamber
by the charge aspirator is heated by the primary heat exchanger
from the exhaust chamber (1). This has the effect of superheating
the vapor. Since the vapor is pumped into the pressurization
chamber by the charge aspirator, increased pressure and temperature
are not reflected back to the cooling system.
[0105] 4. From the pressurization chamber the vapor passes through
the EE coolant turbine (6c). This is analogous to the turbine on a
jet engine. Although it is not mandatory that the charge aspirator
be powered by the turbine, it will probably be the most convenient
implementation.
[0106] 5. After exiting the Energy Extractor turbine, the vapor
passes to the power turbine (7). This turbine will probably be used
to power the exhaust evacuator, a supercharger, and possibly a
auxiliary generator. It is also possible to direct this power to
other applications.
[0107] 6. Vapor which leaves the power turbine is passed to the
condensing radiator (8) which is similar to a typical engine
radiator. Here heat rejected from the system is discharged into the
environment.
[0108] 7. The condensed vapor is routed back to the coolant
reservoir. A small pump may or may not be necessary to accomplish
this.
[0109] 8. Exhaust leaving the piston cylinders is introduced into
the exhaust chamber (1). The primary heat exchanger transfers heat
to the coolant pressurization chamber (5c) which contains coolant
vapor from the charge aspirator.
[0110] 9. Exhaust is aspirated from the exhaust chamber by the
exhaust evacuator (2). This has the effect of "pumping" heat out of
the cylinder and possibly to a secondary heat exchanger.
[0111] Exhaust Based System
[0112] Please refer to FIG. 2. The exhaust based Energy Extractor
operates as follows:
[0113] 1. Exhaust leaving the piston cylinders is introduced into
the exhaust chamber (1). The exhaust chamber contains a primary and
secondary heat exchanger. The primary heat exchanger, which first
receives the exhaust gas and is therefore the hottest, transfers
heat to the pressurization chamber. The secondary heat exchanger
transfers heat to a cooling charge, which will be non-coolant
water, air, or an air/fuel mixture. This ancillary fuel may be an
alcohol such as methanol or ethanol. The cooling charge further
lowers the exhaust gas temperature and pressure.
[0114] 2. The exhaust gas is aspirated from the exhaust chamber by
the exhaust evacuator (2), which pumps it into the exhaust
pressurization chamber (4e). The evacuator, which resembles a
compressor on a turbocharger, will generally be powered by the EE
exhaust turbine (6e), although it may be powered by other methods.
The aspiration of the gas from the exhaust chamber and by
extension, the cylinder during the exhaust stroke, lowers the
temperature of the exhaust gas all the way from the cylinder to the
evacuator. If water is used as a cooling charge for the secondary
heat exchanger, the resulting steam may be injected into the
exhaust evacuator in a manner to augment its aspiration
characteristics.
[0115] 3. The charge aspirator (3) pumps air from the secondary
heat exchanger. If desired, the aspirated air may also contain fuel
vaporized by the secondary heat exchanger.
[0116] 4. Upon leaving the exhaust evacuator the gas enters the
exhaust pressurization chamber (5E). Here it is mixed with the
cooling charge which is pumped into the chamber by the charge
aspirator (3). The mixture is allowed to expand and receives heat
via the primary heat exchanger from the exhaust chamber. Depending
upon the implementation, there may be a catalytic converter or even
a ignition device to ensure complete combustion of exhaust gas
byproducts.
[0117] 5. From the pressurization chamber the heated, pressurized
gas is ported to the "EE Exhaust Turbine (6e)." This turbine, which
resembles an exhaust turbine on a turbocharger, will probably
provide shaft power for the exhaust evacuator and the charge
aspirator.
[0118] 6. After leaving the EE Exhaust Turbine (6e), the gas may
pass through a power turbine (7). This may be used to drive a
turbocharger, an auxiliary generator, or some other device that
uses shaft power.
[0119] 7. Upon leaving the power turbine the gas is discharged to
the exhaust system.
[0120] Combined Exhaust and Coolant Implementation
[0121] Both the exhaust and coolant Energy Extractor systems may be
combined (refer to FIG. 3). This more complex configuration will
result in the most energy recovery possible. The primary heat
exchanger must be modified to allow heat transfer to both the
coolant pressurization chamber and the exhaust pressurization
chamber.
[0122] With this implementation there would be two basic Energy
Extractor units; one would be driven by the exhaust EE turbine and
power the exhaust aspirator; the other would be driven by the
coolant steam EE turbine and power the charge aspirator. Auxiliary
power from a power turbine could be taken from either the exhaust
circuit or the coolant circuit.
[0123] In the Combined Energy Extractor detailed in FIG. 3, the
primary heat exchanger first transfers heat to the exhaust
pressurization chamber (5e); the next section of the exchanger
transfers heat to the coolant pressurization chamber (5c). Leaving
the primary heat exchanger, the exhaust gas is further cooled by
the secondary heat exchanger, which in this implementation
circulates water from the evaporation chamber. This has the effect
of increasing the amount of water vaporized for heating in the
coolant pressurization chamber.
[0124] Note that this particular design uses the nozzle based
evaporation chamber. This same implementation could be done with
the heat exchanger based evaporation chamber.
[0125] In this implementation the power turbine (7) is part of the
coolant EE circuit. While this will probably be the source of most
of the energy recovery, it would also be possible to also install a
power turbine following the EE exhaust turbine in an attempt to
recovery more exhaust gas energy.
[0126] Gas Mix Energy Extractor
[0127] Another method of implementing the Energy Extractor
principles is illustrated in FIG. 4. With this technique steam
aspirated from the evaporation chamber (4) by the charge aspirator
(3) is mixed with exhaust gas which has passed through the exhaust
chamber and the exhaust evacuator. This steam/exhaust gas mixture
is routed to the exhaust pressurization chamber (5e) for
superheating from the primary heat exchanger. The gas mixture is
directed through the EE exhaust turbine and then the power turbine.
In this particular example the power turbine is used to drive the
charge aspirator.
[0128] There are a few advantages to this approach. One feature is
the "water scrubbing" effect on the exhaust gas when it is mixed
with steam aspirated from the evaporation chamber. As the steam
condenses from the mixture, water soluble pollutants such as
nitrous oxide should be removed in the condensate. A second
advantage is that there are less components; no condensing radiator
is used with this arrangement.
[0129] There are several disadvantages to this approach, though.
First, a considerable amount of water will be required to make up
for the loss of steam. As previously noted, about one-third of the
energy released by fuel eventually is dissipated through the engine
cooling system. One gallon of gasoline contains sufficient energy
to vaporize about 15 gallons of water. If the energy normally
dissipated by the cooling system is used to vaporize water, then
five gallons of water will be vaporized for each gallon of gas.
This would require that five gallons of water be available for each
gallon of gasoline that is used.
[0130] It should be possible to recover some of the water from the
exhaust condensate. Burning one gallon of gasoline will normally
produce about one gallon of water. After mixing with the steam, it
would be theoretically possible to recover six gallons of water
from the exhaust for every gallon of gasoline that would be
used.
[0131] Thermodynamic considerations also suggest that this
particular approach probably won't result in as much energy
recovery as with the Energy Extractor Coolant system
implementation. Energy will have to be used to warm water from the
ambient temperature to the temperature of vaporization, as opposed
to the "closed loop system" in which water returned to the
evaporation chamber will be close to the temperature of
vaporization.
[0132] Exhaust Boiler Energy Extractor
[0133] The simplest installation of an Energy Extractor would
involve just the exhaust system components. This approach forfeits
any energy recovery from the cooling system. As previously noted,
though, the exhaust extractor will have the effect of transferring
some of the heat normally dissipated through the cooling system to
be pumped into the exhaust Energy Extractor system. Because of
this, the amount of energy recovered may be greater than what would
be predicted just from typical heat dissipation figures.
[0134] FIG. 5 diagrams an "exhaust boiler" Energy Extractor
implementation. As with the gas mix Energy Extractor, exhaust gas
is mixed with steam in the exhaust pressurization chamber.
Additionally, the system requires water makeup; the water that is
vaporized is loss through the exhaust system. A separate water tank
would be required for use of this system. This particular type of
installation might find application in recreational vehicles which
normally have a good size water reservoir for domestic use.
[0135] This system is different than the previously mentioned
implementations, though, in that the water is vaporized solely by
the exhaust system. There is no separate superheating section.
Because of this, the exhaust heat exchanger is appropriately
described as a boiler.
[0136] The main advantage of this system is its simplicity.
Complete installation will only require an exhaust heat exchanger
boiler, a turbocharger, and a pressurization chamber. The engine
cooling system will remain unchanged. As with the other
implementations, the exhaust that leaves the Energy Extractor
turbine may be routed through a power turbine for further energy
recovery.
[0137] Rankine Exhaust Energy Extractor
[0138] FIG. 6 demonstrates the manner in which a Rankine Steam
circuit could be used with an exhaust heat exchanger boiler and an
exhaust evacuator. In this system there is no mixing of the exhaust
gases and steam. An exhaust heat exchanger boiler is used to
produce hot steam that is routed to a "Rankine power turbine." In
this particular illustration a turbocharger turbine is used to
recover power from the hot steam. The power turbine powers the
exhaust evacuator (2). Exhaust aspirated through the evacuator may
be routed through a second heat exchanger, a power turbine, or to
the exhaust system.
[0139] Steam that exits the Rankine power turbine condenses in a
condensing radiator (8). Condensate water is pumped back to the
exhaust heat exchanger boiler by a feedwater pump. If so desired,
the water could be routed through a secondary exhaust/feedwater
heat exchanger to recover more energy.
[0140] Since heat exchangers are used instead of direct exhaust gas
and steam mixing, it would be expected that this system would be
somewhat less efficient in energy recovery than the corresponding
exhaust boiler energy extractor. The obvious advantage is that
since steam is not loss out the exhaust, no water reservoir is
required for operation.
[0141] Steam Injection Energy Extractor
[0142] The absolute simplest Energy Extractor implementation is
depicted in FIG. 7. As can be seen, this system can be constructed
with just an exhaust heat exchanger boiler and an already installed
turbocharger. High pressure steam from the exhaust boiler is
introduced through the turbocharger turbine casing via a steam
injector. The injector is positioned so the steam strikes the
turbine impellers at nearly a tangential angle. This action causes
the turbine to spin faster and decreases the exhaust back pressure
normally seen with turbochargers.
[0143] Like the exhaust boiler Energy Extractor systems, this
particular system is limited by its dependence on a water
reservoir.
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