U.S. patent application number 12/061401 was filed with the patent office on 2008-10-02 for combination exhaust gas turbine-catalytic converter.
Invention is credited to Ronald Kyle.
Application Number | 20080236149 12/061401 |
Document ID | / |
Family ID | 39791978 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080236149 |
Kind Code |
A1 |
Kyle; Ronald |
October 2, 2008 |
COMBINATION EXHAUST GAS TURBINE-CATALYTIC CONVERTER
Abstract
An exhaust turbine for an internal combustion engine, which may
either serve as a compressor for turbocharging or a turbogenerator
for a hybrid vehicle, has its turbine surfaces and the internal
surfaces of the exhaust turbine housing coated with a catalyst so
the exhaust gases are treated to catalytic conversion as they pass
through the exhaust turbine. The turbine wheel is equipped with a
disk-like slinger at its input end that carries particulate matter
in the exhaust outward radially into a particulate trap and
combustion chamber formed on the interior of the turbine housing.
The combustion chamber is heated by the exhaust gases and
artificial heating such as electrical heating may be used to
preheat the chamber. The combustion products from the burned
particulate matter are added to the exhaust.
Inventors: |
Kyle; Ronald; (Akron,
OH) |
Correspondence
Address: |
GIFFORD, KRASS, SPRINKLE,ANDERSON & CITKOWSKI, P.C
PO BOX 7021
TROY
MI
48007-7021
US
|
Family ID: |
39791978 |
Appl. No.: |
12/061401 |
Filed: |
April 2, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60909549 |
Apr 2, 2007 |
|
|
|
Current U.S.
Class: |
60/299 |
Current CPC
Class: |
F01N 3/2882 20130101;
F05D 2300/611 20130101; F01N 3/037 20130101; F05D 2300/143
20130101; F05D 2220/40 20130101; Y02T 10/6295 20130101; Y02A
50/2322 20180101; Y02T 10/144 20130101; F01N 5/04 20130101; Y02T
10/20 20130101; F02B 37/00 20130101; F01D 5/048 20130101; Y02T
10/12 20130101; Y02T 10/16 20130101; Y02T 10/62 20130101 |
Class at
Publication: |
60/299 |
International
Class: |
F01N 3/10 20060101
F01N003/10 |
Claims
1. An exhaust turbine driven by the exhaust of an internal
combustion engine, having a catalytic coating on the turbine
surface which contacts the exhaust gases to catalytically reduce
noxious products in the gases.
2. The turbine of claim 1 wherein the catalyst includes metal from
the group consisting of platinum, palladium, rhodium, and
vanadium.
3. The exhaust gas turbine of claim 1 wherein the catalyst
constitutes a zeolite.
4. The exhaust gas turbine of claim 1 having a radially extending
slinger disposed at its input end and a radially inward directed
particulate trap formed in the turbine housing in opposition to the
radially outward end of the slinger, whereby particulate matter
combined with the exhaust is directed radially outward into the
trap where it is combusted and added to the input exhaust gases.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional Patent
Application Ser. No. 60/909,549 filed Apr. 2, 2007, which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to an exhaust turbine for an internal
combustion engine and more particularly to an exhaust turbine
having coatings of catalytic converting material so that the
turbine acts as a catalytic converter.
BACKGROUND OF THE INVENTION
[0003] The densely populated regions of the world typically
regulate the permitted levels of several pollutants, or unwanted
emissions, in the exhaust gases generated by transportation
vehicles powered with internal combustion engines (ICE). These
engines are usually fueled by diesel fuel(s), motor gasoline(s),
other reasonable hydrocarbon fuels, alternative fuels from other
than petroleum sources, and combinations thereof.
[0004] Currently diesel-fueled ICE have to comply with regulations
for the amount of non-methane hydrocarbons (NMHC) or non-methane
organic gases (NMOG), carbon monoxide (CO), nitrogen oxides (NOx),
and particulate matter (PM). Controlling these unwanted emissions
to the regulated levels usually requires the use of special
equipment such as catalytic converters and particulate traps to
remove these unwanted emissions from the exhaust. Engine
manufacturers and their customers are continually seeking better
solutions for controlling these unwanted emissions.
[0005] Diesel engines typically are equipped with a turbocharger,
which consists of an exhaust gas turbine (EGT) coupled to and
driving an intake air compressor. This turbocharger is used to
increase the air flow to the engine so that more fuel can be burned
whenever extra power is needed. This typically permits the use of a
smaller ICE (displacement and weight) for the same power
requirements.
SUMMARY OF THE INVENTION
[0006] This invention combines the operations of the catalytic
converter, particulate trap, and turbocharger in one device. As the
exhaust passes through the EGT, catalysts coating the rotor and
housing will provide the same functions as they do in a catalytic
converter. In order to ensure removal of all the PM, a slinger will
be used to direct the PM to a trap in the housing where it will be
oxidized. Energy from these reactions will increase the power
output of the EGT, recovering energy that was once lost to the
atmosphere.
[0007] The EGT typically spins at high speeds in the range of
50,000 rpm to 150,000 rpm or even higher. This turbine wheel acts
as a slinger which slings the PM to the circumference of the
interior of the EGT housing. A strong oxidation catalyst and
electrically-powered resistors can be placed in the housing in the
location where the PM is directed as required to ensure that all of
the PM is oxidized. Any other reasonable heat source may also be
used for this purpose. Energy from the oxidation of the PM will add
to the total energy that is used to power the exhaust gas turbine,
thus recovering some of the energy which would normally be lost to
the atmosphere. The turbine wheel and the EGT housing can be
designed to improve the efficiency of the slinger function and the
PM trap. For example, the diameter of the solid facing of the
turbine wheel can be increased so that it is slightly greater that
the outer diameter of the turbine blades as shown in FIG. 1. This
will provide for a stronger centrifugal separation of the heavier
PM from the exhaust gas.
[0008] Broad application of catalyzed diesel particulate filter
(CDPF) systems for the control or PM began with the introduction of
2007 model year heavy-duty diesel trucks in the United States.
These systems typically operate as a trap for the PM with periodic
oxidation of the PM. An advantage of the EGTCC is that it would
provide for continuous removal of the PM in a passive system. The
EPA reports that there are more than 1.2 million diesel-powered
vehicles were operating with some type of CDPF system in Europe
prior to 2007.
[0009] A catalyst(s) can be added to the EGT housing and turbine
wheel to enhance the oxidation of the PM. Catalyst(s) can also be
added to the EGT turbine wheel and housing to reduce the NOx and
other targeted pollutants to regulated levels. The catalysts
typically used for this purpose are the precious group metals
platinum, palladium, rhodium, vanadium, etc. These catalysts are
typically deposited using a washcoat (typically a mixture of
silicon and aluminum) onto a ceramic, stainless steel, or other
suitable substrate. For example, the housing and turbine wheel of
the EGT might also use such materials as heat resistant cast steel,
titanium, titanium aluminide (TiAl), high strength ceramics,
aluminum, or other suitable materials.
[0010] The most important component of the catalytic reaction is
usually the "loading" of the washcoat with the catalysts (in
suspension) that is applied to the substrate. The washcoat, when
added to the core, forms a rough, irregular surface which has a far
greater surface area than the flat core surfaces. This gives the
converter core a larger surface area, and therefore more places for
active precious metal sites. Heavier concentrations, or loadings,
of the precious metals that cause catalytic reactions typically
increase the effectiveness of the process, with no increase in
substrate surface area. Rhodium, platinum, palladium, vanadium,
etc. which are used in various concentrations in the washcoat are
relatively expensive metals, so it is important to achieve the
proper balance of cost and effectiveness for each EGTCC
application.
[0011] The use of the zeolite family of catalysts may be very well
suited for this EGTCC. Zeolite catalysts are currently used in some
applications in combination with reductants such as ammonia/urea,
especially for the removal of NOx from flue gases, diesel exhausts,
etc. This is commonly referred to as selective catalyst reduction
(SLR). Vanadium catalysts are also used for these SLR applications
and several other catalysts are under consideration. The EPA has
noted that vanadium and base-metal (Cu or Fe) SCR catalysts can
achieve significant NOx reduction in heavy duty diesel engines. The
EPA notes that SCR is a mature, cost-effective solution for NOx
reduction on heavy-duty diesel engines.
[0012] Studies done by Argonne National Laboratory, Sandia National
Laboratory, Adherent Technologies, Degussa Aktiengesellschaft,
Toyota, and others show that these zeolite catalysts are effective
at controlling exhaust emissions of ICE. For example, Argonne has
demonstrated that a zeolite-based catalyst such as Cu-ZSM-5 with a
cerium oxide coating can be very effective for reducing NOx as well
as other unwanted emissions from the exhaust gases. This catalyst,
similar zeolite catalysts, and/or other suitable current and future
catalysts or combinations of these catalysts could be very
effective for this EGTCC application.
[0013] Currently ammonia/urea is the most commonly used reductant
for the SLR of the NOx in the exhaust gases. Argonne proposes that
an alternative method is to use a hydrocarbon in place of the
ammonia/urea reductant. In the case of the exhaust from ICE,
Argonne proposes that the hydrocarbon fuel used for the engine be
used as the reductant. This could reduce the cost of the emission
control system and its operation. It eliminates the need to store a
separate material and ensures that the reductant is available
whenever fuel is available for the ICE. The thermal energy
resulting from the catalytic reactions which take place in the EGT
will increase the power output of the EGT.
[0014] The design and operation of the EGT can be modified to
increase the efficiency of the catalytic action without reducing
its original function. The number of turbine blades can be
increased to provide more catalyst area. If the turbine blades are
coated with a ceramic substrate, the thickness of the blade might
be decreased to keep the mass of the turbine wheel as low as
reasonable. Another option might be to make the turbine wheel from
a high-strength ceramic to reduce the mass and thus the spool-up
time for the EGT.
[0015] The EGTCC will be running for all the time that the ICE is
operating in order to ensure that total exhaust flow is presented
to the PM removal system and the catalysts. Some turbochargers are
controlled by a bypass control or wastegate which diverts a portion
or all of the exhaust flow around the EGT. While the design and
control of these turbochargers could be modified so that all of the
exhaust would flow through the EGT, other turbocharger designs are
already available that direct the entire exhaust flow through the
EGT. These turbocharger designs are more recent and tend to be
referred to as regulated, output control, or variable geometry
turbochargers (VGT).
[0016] Some of these VGT are designed with an adjustable throat
section at the inlet of the turbine wheel. The throat section can
be adjusted to provide for varying engine speeds and desired boost
pressures. Another VGT design provides the same function by using
adjustable vanes which rotate relative to the turbine wheel axis.
Examples of these designs are the Garrett.RTM. VNT.TM. turbocharger
and the Garrett.RTM. VNT.TM. Multivane turbocharger
respectively.
[0017] Borg Warner Turbo Systems has similar models of regulated
turbochargers or VGT which change the inflow angle and/or inflow
speed at the turbine wheel inlet. The advantage for using this
output control incorporated in the VGT over bypass control, which
is usually accomplished by a wastegate, is that the entire exhaust
mass flow is always directed through the EGT. The industry trend is
toward increased use of output controls and these variable geometry
turbochargers. Since for these VGT models, the entire exhaust flow
is always moving through the EGT, these current and future designs
are suitable for the proposed EGTCC.
[0018] Other turbocharger producers also have similar designs that
direct the entire exhaust flow through the EGT.
[0019] The bypass control turbochargers that are installed on
vehicles currently on the highway can easily be replaced by an
EGTCC using output control. For those vehicles produced in 2007 or
later the EGTCC could either replace the turbocharger and current
control systems for PM, NOx, and the other pollutants or those
systems could be left in place. Vehicles produced prior to 2007 can
achieve major reductions in pollutant levels in the exhaust by
replacing the current turbocharger with an EGTCC.
[0020] Combining the catalytic activity with the turbocharger
operation offers the following advantages: [0021] A significant
portion of the thermal energy produced by the oxidation and
reduction activities between the catalysts and the unwanted
emissions will be converted to mechanical energy by the EGT. [0022]
The oxidation and reduction operations are located closer to the
exhaust manifold and there will be less time required for the
catalysts to "warm up" to their optimum operating temperature.
[0023] The ceramic coating on the EGT housing will act as an
insulator and retain more of the thermal energy in the exhaust gas
which will make more power available for the EGT. [0024] A ceramic
coating can be easily added to the exhaust manifold and exhaust
connection between the exhaust manifold and the EGT for the purpose
of insulation to maintain the highest reasonable thermal energy
level at the entrance to the EGT. [0025] Equipment costs are lower
since the costs to produce, install, purchase, inventory, etc. a
separate catalytic converter are eliminated. [0026] The use of
zeolite catalysts and the hydrocarbon reductant could replace some
of the precious group metals catalysts, also saving costs. [0027]
Vehicle operating costs will be lowered since thermal energy that
is lost to the atmosphere today will be converted into mechanical
energy that can be used otherwise to reduce the overall energy
consumption of the vehicle. [0028] The problems of backpressure
created by the currently-used catalytic converters will be
eliminated, thus providing more power output and smoother engine
operation. [0029] Operating the turbocharger at all engine speeds
will provide more power at a given engine speed so that the ICE can
operate at lower rpm for the same power output permitting the
vehicle to run in a higher gear, which generally is more economical
and extends engine life and maintenance periods. [0030] Operating
the turbocharger at all engine speeds will improve oxygen
availability throughout the operational range of the engine which
will reduce the formation of elemental carbon PM. [0031] Flowing
all of the exhaust gas through the turbocharger all of the time
will reduce turbine lag during periods of acceleration. [0032] One
or more additional EGT can be installed immediately after the EGTCC
to capture and usefully employ more of the exhaust energy without
having to be concerned about maintaining proper temperatures at the
catalytic converter inlet. The additional EGT could also be of the
EGTCC form. [0033] The PM would be removed continuously rather than
collecting the PM and then burning it periodically. [0034] Using
the ICE fuel as the reductant will eliminate the concern that
ammonia may be present in the exhaust or that additional steps may
have to be taken to remove excess ammonia from the exhaust. [0035]
Major reductions in exhaust pollutants can be achieved for vehicles
already on the road by replacing the current turbocharger with an
EGTCC. [0036] If necessary, a small catalytic converter can be
placed in the discharge of the EGT housing or just after the exit
of the EGT. The design of this converter could be similar to
current catalytic converters or a reticulated substrate could be
used, in which case it would be prepared similar to the EGT rotor
and housing.
[0037] The above proposal mainly addresses the needs to meet the
regulations established for highway transportation vehicles with
diesel engines. Many of the densely populated areas of the world
have programs in place or planned that will require all diesel
engines to meet similar emission levels in the near future,
including marine, rail, all types of off-the-road equipment,
electric power generation equipment, and any other equipment
powered by diesel engines. This EGTCC could be used to reduce the
regulated emissions for the diesel engines used for all of these
applications. The EGTCC can also be used for any alternative fuels
that might be used in combination with or substituted for typical
diesel fuels in these applications.
[0038] Currently gasoline-fueled ICE have to comply with
regulations for the amount of non-methane hydrocarbons (NMHC) or
non-methane organic gases (NMOG), carbon monoxide (CO), nitrogen
oxides (NOx), and particulate matter (PM). While these regulations
are often the same or similar for ICE regardless of the fuel used
(gasoline, diesel, alternative fuels, etc.), gasoline ICE typically
do not have a problem meeting the PM regulations without the use of
special equipment such as particulate traps. Generally for
gasoline-fueled ICE, controlling these unwanted emissions to the
regulated levels is achieved by using catalytic converters to
remove these unwanted emissions from the exhaust. ICE manufacturers
and their customers are continually seeking better solutions for
controlling these unwanted emissions.
[0039] Gasoline-fueled vehicles currently on the global highways
when compared to diesel-fueled vehicles have a much lower
percentage that are equipped with turbochargers. Typically
turbochargers have been used on gasoline engines to improve
performance and a significant portion of the turbochargers have
been added as an aftermarket item. The recent emphasis on fuel
economy due to the rapid increase in energy prices and taxes and
the estimated impact of CO2 on climate changes has greatly
increased the global automotive industry's interest in the use of
turbochargers. The industry, especially in Europe, has been moving
to vehicles with smaller gasoline-fueled engines (displacement and
weight) equipped with turbochargers to provide extra power for
acceleration and as otherwise needed. This permits the use of
smaller more fuel efficient engines without sacrificing
performance. This trend is forecasted to grow rapidly for the
foreseeable future.
[0040] This proposal is to combine the operations of the catalytic
converter, and turbocharger in one device. As the exhaust passes
through the EGT, catalysts coating the rotor and housing will
provide the same functions as they do in a catalytic converter. In
the event of a need for the removal of PM for new engine designs
(for example "homogeneous charge compression ignition" or HCCI) or
new fuel developments to ensure removal of all the PM, a slinger
could be used to direct the PM to a trap in the housing where it
will be oxidized. Energy from these reactions will increase the
power output of the EGT, recovering energy that was once lost to
the atmosphere. However, currently for gasoline, alternative fuels
for gasoline-fueled engines, and combinations of those fuels, the
currently used catalytic converter is all that is required to
control the levels of the unwanted exhaust emissions to regulated
levels.
[0041] The EGTCC for these applications will be the same as for the
diesel-fueled ICE except that the special provisions to remove PM
may not be required. All of the description above for
diesel-powered vehicles also applies for gasoline-powered
vehicles.
[0042] Gasoline engines typically control the engine power output
by throttling the air available for combustion, and the fuel is
controlled to match the air flow. Power output from diesel engines
is controlled by the amount of fuel available for combustion and
the air flow is not restricted or throttled. The diesel engines
also operate over a smaller speed range than do gasoline engines.
Therefore, the volume of exhaust flow for the gasoline engines
varies much more than it does for diesel engines. Consequently,
under normal operation the gasoline engine is operating with
relatively small exhaust flows compared to full power high speed
operations. The use of variable geometry turbochargers enhances the
recovery of thermal exhaust energy at throttled conditions and can
be designed to operate more efficiently at certain targeted
operating conditions.
[0043] The hybrid operating configurations and conditions as
outlined in the Hybrid Electric Conversion LLC proposal for a
series-parallel hybrid electric drive system permits the internal
combustion to be operated at all times in a full throttle or near
full throttle condition and over a relatively narrow speed range,
which will permit the EGTCC to extract significantly more of the
thermal exhaust energy and thus reduce the fuel consumption of the
engine. An example of this application is shown in FIG. 2.
[0044] The vehicle fleets in Western Europe, Japan, Canada, and the
USA are mostly equipped with catalytic converters and not much
advantage would be gained from equipping vehicles currently in use
with an EGTCC. However, there are countries that could benefit from
such retrofits to improve the emissions control and performance of
the vehicles.
[0045] The above proposal mainly addresses the needs to meet the
regulations established for highway transportation vehicles with
gasoline engines. Many of the densely populated areas of the world
have programs in place or planned that will require all gasoline
engines to meet similar emission levels in the near future,
including marine, rail, all types of off-the-road equipment,
electric power generation equipment, and any other equipment
powered by gasoline engines. This EGTCC could be used to reduce the
regulated emissions for the current and future gasoline engines
used for all of these applications. The EGTCC can also be used for
any alternative fuels that might be used in combination with or
substituted for typical gasoline fuels in these applications.
[0046] The benefits for the use of turbochargers generally apply to
hybrid electric vehicles (HEV) as well. Both diesel powered and
gasoline powered HEV would have most or all of the same benefits as
listed above for those vehicles.
[0047] In addition, there are other benefits that can be derived
from using an EGTCC on these HEV to power an electric generator.
This EGTCC driven electrical generator (EGTDEG) may be added to an
HEV that has no turbocharger or it may be added on the exhaust flow
after a turbocharger that is already installed on the vehicle.
Power supplied by the EGTDEG could be used in the following ways as
relevant depending on the HEV design and personal preference:
[0048] 1. To provide additional recharging power to the HEV's
energy storage system(s) [0049] 2. To provide additional power to
HEV's primary drive motor(s) [0050] 3. To provide additional power
to the HEV's alternator/motor/starter system [0051] 4. To provide
additional power to operate the HEV's electrically-powered
accessories directly [0052] 5. To provide power to an electric
motor or motor/generator added to the HEV to use the power
generated by the EGTDEG to supply power to the motive drive system
at either end of the ICE crankshaft or any other reasonable
location in the drivetrain
[0053] Some mild hybrids are referred to as Stop/Start hybrids.
This system conserves energy by shutting off the ICE when the
vehicle is at rest, such as at a traffic light, and automatically
re-starting it when the driver releases the brake and/or pushes the
gas pedal to go forward. Examples of Stop/Start hybrids are the
Chevrolet Silverado, Saturn Vue, BMW 1-series, Citroen C2, etc.
While all the items listed above can be applicable for any HEV
system, items 3, 4, and 5 generally would apply to a mild
hybrid.
[0054] Medium strength hybrids, such as the current Honda Civic and
Accord hybrids, strong hybrids, such as those currently offered by
Toyota and those used for most of the current bus and other heavy
duty vehicle applications, and other current and future hybrids
also can benefit, usually more than most mild hybrids.
[0055] The Hybrid Electric Conversion LLC proposal for a
series-parallel hybrid electric drive system would derive the most
benefit from the use of the EGTDEG. In this system the ICE is
always operating unthrottled and at or near to its most efficient
operating conditions. Therefore, there is always a good opportunity
to extract significant power from the EGTDEG. Series hybrids could
have a similar benefit depending on the operating conditions for
the ICE. An example of this application is shown in FIG. 2.
[0056] Any non-hybrid, or conventionally powered vehicle could be
converted to a mild hybrid by the addition of an EGTDEG in
combination with the addition of an electric motor or
motor/generator to the vehicle to use the power generated by the
EGTDEG. The EGTDEG could supply power to the motive drive system at
either end of the ICE crankshaft; for example, through a
starter/alternator and/or an additional motor/generator, or any
other reasonable location. The addition of a battery and/or other
energy storage and other associated equipment will convert the
vehicle into an HEV to gain even greater operating efficiency.
[0057] All HEV configurations could benefit from the use of two or
more EGTDEG in series to extract the maximum amount of energy from
the exhaust. Depending on the application, most likely only one of
these locations would require the use of an EGTCC to reduce the
unwanted pollutants from the exhaust to within their regulated
levels. The other two locations could use a conventional EGT. Since
there is not a catalytic converter downstream of these EGTCCs
and/or EGTs as the case may be, it is desirable to convert as much
of the exhaust thermal energy as reasonable to power the vehicle.
Some designers might prefer to use a turbocharger to improve the
control the ICE intake air flows. Some designers may prefer to use
a turbocharger in order to use a smaller ICE. Depending on the
design of the vehicle, its designated use, and the designers'
preferences there could be several combinations of
exhaust-gas-driven equipment on the vehicle, some with EGTCC and
other with a conventional EGT.
[0058] The same benefit could be achieved by using two or more
EGTDEG in parallel and/or in series parallel combinations. The
conditions for these arrangements would be similar to those
described above for a series arrangement. At least one EGTCC must
be used in each parallel exhaust train to ensure that the unwanted
emissions are removed in accordance with the respective
regulations. An example of two EGTCC in series is shown in FIG.
2.
[0059] Currently, radial turbines are most often used to extract
the thermal energy from the ICE exhaust. However, axial turbines
can be used with good results and often are used for ICE with
larger displacements. An axial turbine would combine the functions
of using multiple radial turbines to extract more of the thermal
exhaust energy for use as motive power and could be especially
effective for powering an electrical generator to provide power for
HEV configurations.
[0060] This proposal is to combine the operations of the catalytic
converter, and turbocharger and/or an exhaust gas-turbine-driven
electrical generator in one device. As the exhaust passes through
the axial exhaust gas turbine, catalysts coating the blades of the
rotor and stator as well as the housing and turbine body will
provide the same functions as they do in a catalytic converter. The
application of these catalysts could be done in a manner similar to
that used for the radial turbines and housings. The turbine blades
of the axial turbine can be configured to provide for a stronger
centrifugal separation of the heavier PM from the exhaust gas. The
PM would be directed into traps in the housing where it can be
oxidized using a strong oxidizing catalyst and heat which can be
added to the trap as required. The slinger and trap could be
similar to that proposed for the radial turbine. Energy from these
reactions as they take place in the exhaust gas turbine will
increase the power output of the exhaust gas turbine, recovering
energy from these reactions that currently is lost to the
atmosphere.
[0061] The historic emphasis has been for the reduction of
emissions from the exhausts of internal combustion engines and for
improving the fuel economy of these engines. The recent increases
in the cost for energy, especially liquid fuels; increasing taxes
on liquid fuels, especially in Europe; further reduction of the
currently regulated exhaust emissions, non-methane hydrocarbons,
carbon monoxide, nitrogen oxides, and particulate matter; the
seasonal concern for climate changes and the potential impact of
carbon dioxide on the global atmosphere; and political instability
in the major crude oil producing regions has created a
significantly increased global interest for continued improvements
in the performance of all internal combustion engines.
[0062] The focus of these efforts, which has been on highway
transportation vehicles, is now expanding to include all internal
combustion engines for all uses. This includes the use of these
engines for small farm or home implements to the largest
earthmover, ocean vessel, or electric generators. The fuel can be
diesel, gasoline, alcohols, vegetable oils, hydrogen, natural gas,
or any other fuels that are suitable for these internal combustion
engines. The internal combustion engines may use different cycles,
different ignition techniques, and use many different operating
techniques.
[0063] The exhaust flows from these internal combustion engines,
using any of these fuels or combinations of these fuels are very
similar. Therefore, the proposed exhaust gas turbine catalytic
converter combination can be used to clean the exhausts from all of
these combinations. This device can also be used to extract the
thermal energy from the exhaust and used in various ways to
significantly reduce the fuel consumption of these internal
combustion engines.
[0064] Currently there are many uses of gas turbine engines for
industrial applications and for power generation. The exhaust from
these gas turbines, like that from internal combustion engines,
contains unwanted pollutants as well as large quantities of thermal
energy. These applications could derive the same benefits as the
other internal combustion engines by using an exhaust gas turbine
catalytic converter combination to reduce the unwanted emissions
and increase the fuel efficiency.
[0065] Currently the exhaust gases from these plants have the same
pollutants as do the internal combustion engines and contain very
large quantities of thermal energy. They also contain other
pollutants such as sulfur compounds and mercury. After the sulfur
has been removed from these exhaust gases the exhaust gas turbine
catalytic converter combination could be used to extract the
unwanted pollutants such as hydrocarbons, carbon monoxide, nitrogen
oxides, and particulate matter from these exhaust gases and recover
large quantities of thermal energy and direct that to electric
power generation at the same time. Another option could be to
remove the sulfur using an exhaust gas turbine catalytic converter
combination specially designed to remove the sulfur, followed by
those exhaust gas turbine catalytic converter combinations designed
to remove the other pollutants. As for the other applications,
energy from these reactions as they take place in the exhaust gas
turbine catalytic converter will increase the power output of the
exhaust gas turbine, recovering energy from these reactions that
currently is lost to the atmosphere.
[0066] The exhaust gas turbine catalytic converter combinations as
described above are used either to drive an air compressor to
provide additional air to the internal combustion engine or to
power an electrical generator. Another application for the use of
the power provided by the exhaust gas turbine catalytic converter
combination is to drive a hydraulic pump. This hydraulic power
could be used to drive a hydraulic motor in the same manner as the
electric generator is used to drive an electric motor. This
hydraulic system would have similar applications as described above
for the electric generator. However, a hydraulic energy storage
system would be used in place of an electrical energy storage
system and the hybrid electric vehicle system would be replaced by
current or future hydraulic hybrid vehicle systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] Other objects, advantages and applications of the present
invention will be made apparent by the following detailed
description of a preferred embodiment of the invention. The
description makes reference to the accompanying drawing in
which:
[0068] FIG. 1 is a cross-sectional view through an exhaust gas
turbine formed in accordance with the present invention for
performing a catalytic conversion function on the gases passing
through the turbine and separating and combusting the particulate
matter in the exhaust.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0069] The preferred embodiment of the invention constitutes a
turbine driven by exhaust gases from an internal combustion
vehicle, which may be gasoline or diesel type. The output shaft of
the turbine which is driven by the exhaust gases may be used to
power either a compressor, for conventional turbocharging purposes,
or an alternator/generator for providing electric power for a
hybrid vehicle.
[0070] In the cross section of the exhaust driven turbine of the
drawing, the numeral 1 represents the exhaust gas turbine wheel.
The turbine wheel is conventional with a number of vanes.
[0071] While FIG. 1 depicts a radial compressor, the invention
could be equally applicable to an axial compressor. The input end
of the compressor, which receives the exhaust, shown to the right
of FIG. 1, has a disk-like radial slinger extension 2 which
receives the incoming exhaust gases. The slinger extends radially
beyond the ends of the turbine wheels. The particulate matter in
the incoming exhaust gases, being of higher density than the gases
themselves, tends to move outward radially along the slinger 2 and
are thrown into a particulate trap and combustion chamber 4 formed
in the exhaust gas turbine housing 3. This particulate trap and
combustion chamber 4 is of course heated by the exhaust gases. It
may be preheated to reach combustion temperatures by electrical
resistive heating elements or the like. The particulate matter
slung into the trap is combusted and the combustion gases from the
particulate matter mix with the entering exhaust gases which enter
through a chamber 5 extending around the perimeter of the turbine.
The chamber 5 narrows in cross section as it extends from the
entrance of the exhaust gases to the outlet which feeds the turbine
blades.
[0072] Both the surfaces of the turbine blades and the interior
surface of the exhaust turbine housing are coated with a catalyst
of the conventional type used in catalytic converters, such as
precious group metals deposited as taught in the Summary of the
Invention. Alternatively, zeolite or vanadium catalysts may be
used, depending upon the combustion fuel.
[0073] The output shaft 6 of the turbine may be used to drive a
compressor for turbocharging applications, or a generator for
providing electrical power to a hybrid vehicle.
[0074] A supplemental catalytic converter may be provided
downstream of the converter/turbine to further reduce the
pollutants in the exhaust.
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