U.S. patent application number 11/851734 was filed with the patent office on 2008-01-31 for energy recovery system in an engine.
Invention is credited to Triantafyllos P. Tafas.
Application Number | 20080022682 11/851734 |
Document ID | / |
Family ID | 38002376 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080022682 |
Kind Code |
A1 |
Tafas; Triantafyllos P. |
January 31, 2008 |
ENERGY RECOVERY SYSTEM IN AN ENGINE
Abstract
A energy recovery system for an internal combustion engine which
dynamically allocates heat energy to multiple vehicle accessory
systems
Inventors: |
Tafas; Triantafyllos P.;
(Rocky Hill, CT) |
Correspondence
Address: |
KELLEY DRYE & WARREN LLP
400 ALTLANTIC STREET , 13TH FLOOR
STAMFORD
CT
06901
US
|
Family ID: |
38002376 |
Appl. No.: |
11/851734 |
Filed: |
September 7, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11266948 |
Nov 4, 2005 |
|
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11851734 |
Sep 7, 2007 |
|
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Current U.S.
Class: |
60/618 ;
60/39.093 |
Current CPC
Class: |
F01K 23/10 20130101;
B60L 50/16 20190201; F01N 5/02 20130101; F01N 5/04 20130101; B60L
3/0023 20130101; B60L 2240/36 20130101; Y02T 10/70 20130101; F01K
23/065 20130101; Y02T 10/7072 20130101; F02G 2260/00 20130101 |
Class at
Publication: |
060/618 ;
060/039.093 |
International
Class: |
F01N 5/02 20060101
F01N005/02 |
Claims
1. An internal combustion engine system comprising: an internal
combustion engine producing heated emissions from one or more
combustion chamber(s), a gaseous matter generator connected
proximal to said combustion chamber(s), said gaseous matter
generator operatively configured to receive said heated emissions
from said one or more combustion chamber(s) and to apply the heat
from said heated emissions to produce gaseous matter; a turbine,
driven by said gaseous matter, having a compartment with a shaft
extending therethrough, said compartment housing an impeller on
said shaft; an exhaust gas conduit configured to direct exhaust gas
into said compartment in a manner to impel said impeller; and a
gaseous matter conduit from said gaseous matter generator
configured to direct exhaust gas into compartment in a manner to
impel said impeller.
2. An internal combustion engine system, in accordance with claim
1, wherein said gaseous matter is steam.
3. An internal combustion engine system, in accordance with claim
1, wherein said gaseous matter generator comprises a condenser,
operatively connected to said turbine by a first conduit and a
boiler, operatively connected to said condenser by a second
conduit; said condenser and said first and second conduits enclosed
in a fluid jacket operatively configured to circulate heated
coolant.
4. An internal combustion engine system, in accordance with claim
1, further comprising a fluid reservoir heater having a gaseous
matter conduit, said gaseous matter conduit operatively connected
to said gaseous matter generator by conduits.
5. A heated engine fluid reservoir comprising: a heat source,
containing a fluid, comprising an input source fluid port and an
output source fluid port; a distribution allocator, containing said
fluid, connected to said heat source by a fluid conduit, comprising
electrically operable fluid valves operatively configured to
interconnect a plurality of input fluid ports and output fluid
ports; a fluid pump operatively, containing said fluid, connected
to said distribution allocator, said fluid pump capable of pumping
fluid through said heat source and into said distribution
allocator; and an engine fluid reservoir having a fluid conduit
thermally coupled to the internal surface of said engine fluid
reservoir, said fluid conduit operatively connected to said input
port and said output port of said distribution allocator.
6. A heated engine fluid reservoir, in accordance with claim 5,
where said heat source further comprises a temperature sensor.
7. A heated engine fluid reservoir, in accordance with claim 5,
where said fluid reservoir heater further comprises a temperature
sensor.
8. A heated engine fluid reservoir, in accordance with claim 5,
where said heat source is a heat-exchanger.
9. A heated engine fluid reservoir, in accordance with claim 5,
where said heat source is a battery powered electrical heater.
10. A heated engine fluid reservoir, in accordance with claim 5,
where said beat source is an electrical heater powered by
electricity generated from engine heat.
11. A heated engine fluid reservoir, in accordance with claim 5,
wherein said heat source is powered by electricity produced by a
turbine-generator.
12. A heated engine fluid reservoir, in accordance with claim 11,
wherein the turbine-generator is a steam powered
turbine-generator.
13. A heated engine fluid reservoir, in accordance with claim 5,
wherein said fluid is anti-freeze fluid.
14. A heated engine fluid reservoir, in accordance with claim 13,
wherein said anti-freeze fluid is alcohol.
15. A heated engine fluid reservoir, in accordance with claim 13,
wherein said anti-freeze fluid is methanol.
16. A heated engine fluid reservoir, in accordance with claim 13,
wherein said anti-freeze fluid is ethylene glycol.
17. A heated engine fluid reservoir, in accordance with claim 13,
wherein said anti-freeze fluid is propylene glycol.
18. A heated engine fluid reservoir, in accordance with claim 13,
wherein said anti-freeze fluid is a mixture of ethylene glycol and
propylene glycol.
19. A heated engine fluid reservoir, in accordance with claim 13,
wherein said anti-freeze fluid is organic acid technology
anti-freeze.
20. A heated engine fluid reservoir, in accordance with claim 5,
where said heat source is chosen, on a priority basis, from the
prioritized group consisting of an electrical heater powered by
electricity generated from engine heat and a battery powered
electrical heater.
21. An energy recovery system in a vehicle comprising: a heat
source, containing a fluid, comprising an input source fluid port
and an output source fluid port; a distribution allocator,
containing said fluid, connected to said heat source by a fluid
conduit, comprising electrically operable fluid valves operatively
configured to interconnect a plurality of input fluid ports and
output fluid ports; a fluid pump operatively, containing said
fluid, connected to said distribution allocator, said fluid pump
capable of pumping fluid through said heat source and into said
distribution allocator; a controller electrically connected to said
distribution allocator and operatively configured to control the
position of said electrically operable fluid valves; and a
plurality of temperature sensors configured to perform temperature
measurements of said fluid at diverse locations; and a controller
logic unit comprising a processor and an electronic memory
containing executable code to generate controller commands, said
controller logic unit operatively configured to receive said
temperature measurements from said plurality of temperature
sensors, perform said executable code, and transmit said generated
commands to said controller.
22. An energy recovery system, in accordance with claim 21, where
said heat source is a heat-exchanger.
23. An energy recovery system, in accordance with claim 21, where
said heat source is a battery powered electrical heater.
24. An energy recovery system, in accordance with claim 21, where
said heat source is an electrical heater powered by electricity
generated from engine heat.
25. An energy recovery system, in accordance with claim 21, wherein
said heat source is powered by electricity produced by a
turbine-generator.
26. An energy recovery system, in accordance with claim 25, wherein
the turbine-generator is a steam powered turbine-generator.
27. An energy recovery system, in accordance with claim 21, wherein
said fluid is anti-freeze fluid.
28. An energy recovery system, in accordance with claim 27, wherein
said anti-freeze fluid is alcohol.
29. An energy recovery system, in accordance with claim 27, wherein
said anti-freeze fluid is methanol.
30. An energy recovery system, in accordance with claim 27, wherein
said anti-freeze fluid is ethylene glycol.
31. An energy recovery system, in accordance with claim 27, wherein
said anti-freeze fluid is propylene glycol.
32. An energy recovery system, in accordance with claim 27, wherein
said anti-freeze fluid is a mixture of ethylene glycol and
propylene glycol,
33. An energy recovery system, in accordance with claim 27, wherein
said anti-freeze fluid is organic acid technology anti-freeze.
34. An energy recovery system, in accordance with claim 21, where
said heat source is chosen, on a priority basis, from the
prioritized group consisting of an electrical heater powered by
electricity generated from engine heat and a battery powered
electrical heater.
35. A vehicle brake de-icing system comprising: a heat source,
containing a fluid, comprising an input source fluid port and an
output source fluid port; a distribution allocator, containing said
fluid, connected to said heat source by a fluid conduit, comprising
electrically operable fluid valves operatively configured to
interconnect a plurality of input fluid ports and output fluid
ports; a fluid pump operatively, containing said fluid, connected
to said distribution allocator, said fluid pump capable of pumping
fluid through said heat source and into said distribution
allocator; and a fluid conduit thermally coupled to at least one
vehicle brake system component, said fluid conduit operatively
connected to said input port and said output port of said
distribution allocator.
36. A vehicle brake de-icing system, in accordance with claim 35,
where said heat source further comprises a temperature sensor.
37. A vehicle brake de-icing system, in accordance with claim 35,
where said brake system component further comprises a temperature
sensor.
38. A vehicle brake de-icing system, in accordance with claim 35,
where said heat source is a heat-exchanger.
39. A vehicle brake de-icing system, in accordance with claim 35,
where said heat source is a battery powered electrical heater.
40. A vehicle brake de-icing system, in accordance with claim 35,
where said heat source is an electrical heater powered by
electricity generated from engine heat.
41. A vehicle brake de-icing system, in accordance with claim 35,
wherein said heat source is powered by electricity produced by a
turbine-generator.
42. A vehicle brake de-icing system, in accordance with claim 41,
wherein the turbine-generator is a steam powered
turbine-generator.
43. A vehicle brake de-icing system, in accordance with claim 35,
wherein said fluid is anti-freeze fluid.
44. A vehicle brake de-icing system, in accordance with claim 43,
wherein said anti-freeze fluid is alcohol.
45. A vehicle brake de-icing system, in accordance with claim 43,
wherein said anti-freeze fluid is methanol.
46. A vehicle brake de-icing system, in accordance with claim 43,
wherein said anti-freeze fluid is ethylene glycol.
47. A vehicle brake de-icing system, in accordance with claim 43,
wherein said anti-freeze fluid is propylene glycol.
48. A vehicle brake de-icing system, in accordance with claim 43,
wherein said anti-freeze fluid is a mixture of ethylene glycol and
propylene glycol.
49. A vehicle brake de-icing system, in accordance with claim 43,
wherein said anti-freeze fluid is organic acid technology
anti-freeze.
50. A vehicle brake de-icing system, in accordance with claim 35,
where said heat source is chosen, on a priority basis, from the
prioritized group consisting of an electrical heater powered by
electricity generated from engine heat and a battery powered
electrical heater.
Description
[0001] This application is a continuation-in-part application of
U.S. patent application Ser. No. 11/266,948, filed Nov. 4, 2005.
All references cited in this specification, and their references,
are incorporated by reference herein where appropriate for
teachings of additional or alternative details, features, and/or
technical background.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention includes an energy capture system and
method for recovering heat energy from the exhaust gases of an
internal combustion engine.
[0004] 2. Description of Related Art
[0005] In conventional internal combustion engines, a mixture of
air and fuel is introduced into the engine, where it is compressed
and then ignited. The burning gases expand, do work, and then are
expelled from the engine. The actual amount of kinetic energy or
mechanical work that is extracted from the internal combustion
generally depends upon the thermal efficiency of the internal
combustion engine. What is not extracted is expended as waste
heat.
[0006] Thermal efficiency is the percentage of energy taken from
the combustion which is actually converted to mechanical work. In a
typical low compression engine, the thermal efficiency may be only
about 26%. In a highly modified engine, such as a race engine, the
thermal efficiency may be about 34%.
[0007] In a generic internal combustion engine, only 20% of the
total energy available may be converted to useful energy. Of the
remaining 80% of the total energy, approximately 38% may be lost
through exhaust heat, 36% through water heating in the cooling
system and 6% through motor friction.
[0008] There have been various schemes to capture energy from the
exhaust gases and heated engine cooling water.
[0009] U.S. Pat. No. 4,439,999, Mori, et aL., discloses an internal
combustion engine and an absorption type refrigeration system which
makes use of both the engine exhaust gas and the heated engine
cooling water. The internal combustion engine and the absorption
type refrigeration system are combined in such a manner that the
exhaust gas of the internal combustion engine is utilized as the
heat source for a first gaseous refrigerant generator having the
highest operating temperature in the system, while heated engine
cooling water is utilized as the heat source for another generator
which operates at a temperature lower than the operating
temperature of the first gaseous refrigerant generator.
[0010] U.S. Pat. No. 6,119,457 to Kawamura describes a heat
exchange apparatus having high and low temperature heat sources
comprising porous material provided in an exhaust passage from a
ceramic engine in communication with a supercharger connected to
the ceramic engine. The heat exchange apparatus comprises a high
temperature heat exchanger having a steam passage provided in an
exhaust gas passage through which an exhaust gas passes whereby
steam is heated, and a low temperature heat exchanger provided in
the portion of the exhaust gas passage on the downstream side of
the high temperature heat exchanger which has a water passage for
heating water by the exhaust gas. The ceramic engine has a steam
turbine type supercharger provided with a steam turbine driven by
the steam from the high temperature heat exchanges, a compressor,
and a condenser which separates a fluid discharged from the steam
turbine into water and low temperature steam. Pressurized air from
the compressor is supplied to the combustion chamber, which presses
down a piston to carry out compression work during an intake
stroke. Thus, the supercharger is driven by the thermal energy
recovered from an exhaust gas by the same heat exchanger
apparatus.
[0011] An example of an energy recovery system is also disclosed in
Japanese Patent Laid-Open No. 1799721993. This energy recovery
system has an energy recovery unit provided with a first turbine
installed in an exhaust passage and a generator operated by the
first turbine, a turbocharger provided with a second turbine
connected to an outlet-side passage of the first turbine and a
supercharging compressor operated by the second turbine, and a
waste gate provided in the outlet-side passage of the first
turbine. The energy recovering operation is carried out by the
energy recovery unit when the temperature of the exhaust gas is
high.
[0012] Exhaust gas energy from an internal combustion engine may
also be used to provide a heated water source, for example, while
the mechanical power of the engine may be used simultaneously to
generate electricity. In Japanese Patent Laid-Open No. 33707/1994,
there is disclosed a system making use of exhaust gas energy from a
turbocharger attached to a heat insulation type gas engine to
produce steam that is used to drive a steam turbine so as to
produce electric energy and heated water. A turbocharger is driven
by the exhaust gas energy from the heat insulating gas engine and
the generator/energy recovery unit is driven by the exhaust gas
energy from the turbocharger. The thermal energy of the exhaust gas
directed to the energy recovery unit is converted into steam by a
first heat exchanger, and recovered as electric energy by driving a
steam turbine. Heated water is generated by the high-temperature
steam from the steam turbine by an operation of a second heat
exchanger, and utilized as a hot water supply source.
[0013] In U.S. Pat. No. 4,803,958 to Erickson, there is disclosed
an open-cycle absorption apparatus for compressing steam from a low
pressure to a higher pressure. The apparatus is used for upgrading
low-temperature jacket-cooling heat from an internal combustion
engine to useful pressure steam. A simple heat-exchange apparatus
is involved, using the extra temperature availability of the hot
exhaust gas as the driving medium.
[0014] There have recently been higher efficiency vehicles powered
using hybrid concepts that involve internal combustion engines in
combination with an electric generator that powers an electric
motor. The generator utilizes some of the kinetic energy that would
otherwise be converted into heat by friction in the vehicle is
braking system. While systems such as described above in
combination with such hybrid systems may further improve energy
storage in such cars, the loss of energy through the emission
system would remain high. What is needed is a system that would
convert a significant percentage of the power lost as heat to
electrical power and create a more efficient hybrid vehicle.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a drawing showing the integration of components of
an embodiment energy recovery system, including a heat collection
subsystem and a heat expending exhaust subsystem, as well as a
two-stage turbine that interfaces with the two subsystems
simultaneously;
[0016] FIG. 2 is a drawing showing the incorporation of the energy
recovery system of FIG. 1 in an automobile, according to an
embodiment of the present invention.
[0017] FIG. 3 is a drawing schematically showing an energy recovery
system which derives heat from various engine components and
allocates the energy to a plurality of accessories. For purposes of
clarity, the figure shows only the forward paths from the heat
sources to the accessories. A complete presentation would also
include the corresponding return paths returning from the
accessories to the heat sources.
SUMMARY OF THE INVENTION
[0018] The disclosed system comprises an energy recovery system in
internal combustion engines.
[0019] In a first embodiment, the energy recovery system comprises
a steam generating chamber located proximal to the engine, such as
immediate contact with the exhaust manifold, that is operatively
configured to receive exhaust fumes from one or more combustion
chambers in the internal combustion engine and one or more fluids
from a fluid reserve and to convert such fluid into steam. In such
embodiment, the steam generated in the steam chamber is directed
through a steam inlet to an electrical generator component
comprising a turbine and electrical generator. The electrical
generator component is operatively configured with respect to the
steam inlet such that the steam turns the turbine which in turn
causes the generator to generate electricity. The electricity
produced may be used by the engine contemporaneously or stored for
later use, for example, when the engine is not using combustion to
generate rotation of the wheels on a hybrid vehicle.
[0020] In one embodiment, the system involves a heat collection
system proximal to an internal combustion engine block, the heat
collection system configured to transfer heat to a steam generating
boiler. Both the steam and exhaust gases simultaneously drive a
turbine of an electric generator which in turn is connected to an
electric motor. The power from the electric motor supplants the
power from the internal combustion engine to propel a vehicle, for
example. In one embodiment, the heat collection system is
immediately proximal to the engine, such as connected to the
manifold.
[0021] Aspects disclosed herein include:
[0022] An internal combustion engine system comprising an internal
combustion engine producing heated emissions from one or more
combustion chamber(s); a steam generator connected proximal to the
combustion chamber(s), the steam generator operatively configured
to receive the heated emissions from the one or more combustion
chamber(s) and to apply the heat from the heated emissions to
produce steam, and configured to direct the steam towards a turbine
in a manner to cause the turbine to turn; an electric generator
operatively connected to the turbine, the electric generator
operatively configured to produce electricity upon turning of the
turbine.
[0023] An energy recovery, system comprising an engine having a
combustion chamber; a coolant subsystem communicating with the
combustion chamber; an exhaust subsystem integral to the combustion
chamber; a boiler in communication with the coolant subsystem, the
boiler operatively configured to generate steam in cooperation with
the coolant subsystem, an energy converter operatively configured
to simultaneously receive the steam from the boiler and to receive
the exhaust gases from the exhaust subsystem and to convert energy
associated with the steam and exhaust gases into mechanical energy;
an electric generator in communication with the energy converter
operatively configured to convert the mechanical energy from the
energy converter to electrical energy, wherein the engine and the
electric generator are cooperatively configured to propel a
vehicle.
[0024] An energy recovery system comprising an engine having a
combustion chamber producing hot pressured exhaust gases; an energy
collection subsystem housing a liquid energy carrier medium, the
energy collection subsystem operatively configured to allow heat
from the hot pressured exhaust gases of the combustion chamber to
pass into the liquid energy carrier medium; an energy chamber
connected to the energy collection subsystem operatively configured
to convert the energy carrier medium from a liquid to a gaseous
state; a combustion exhaust subsystem integral to the combustion
chamber, the combustion exhaust subsystem operatively configured to
receive hot pressured exhaust gases from the combustion chamber; an
energy converter operatively configured to communicate
simultaneously with the energy chamber and with the combustion
exhaust subsystem, the energy converter having a shaft operatively
configured to be rotated by the energy carrier medium in a gaseous
state and to convert pressure energy from the exhaust gases in the
combustion exhaust system into mechanical power; a converter
attached to the energy converter operatively configured to convert
the mechanical power of the energy converter to electrical power;
wherein the engine and the converter are configured to provide
energy to propel a vehicle.
[0025] A method of recovering waste heat energy from exhaust gases
produced by combustion in an internal combustion engine, the method
comprising the steps of: transferring heat from the engine to a
primary coolant loop; directing exhaust gases from the engine to a
first impeller in a first chamber connected to a shaft operatively
connected to an electric generator; directing the exhaust gases
from the first chamber to an exhaust conduit; transferring heat
from the exhaust conduit to a heat conducting member connected to a
secondary cooling loop; transferring heat from the primary and
secondary cooling loops to a second chamber operatively configured
to produce steam; directing steam from the second chamber to a
second impeller operatively connected to the shaft operatively
connected to the first impeller, the second chamber being
positioned in a third chamber: directing the steam from the third
chamber to a condenser operatively configured to condense the steam
to liquid; directing the liquid from the condenser to the primary
cooling circuit.
[0026] In a further embodiment, heat from the engine and exhaust
system may be used to heat a working fluid that may then be used to
operate, or heat, a variety of passenger compartment and engine
accessories. Examples of such accessories include windshield
de-icers, windshield wiper heaters, locks, door handles, windshield
wiper fluid tank heaters, electric motor bearing heaters, battery
heaters, passenger compartment contact heaters, fuel tank heaters,
and brake system component heaters.
[0027] The capacity of the energy recovery system may not be
sufficient to simultaneously operate the full suite of accessories.
In addition, the duty cycle of some of the accessories may depend
on environmental conditions. The distribution of the available
heated working fluid may therefore be selectively controllable on a
prioritized basis. Such distribution may be manually selected or
automatically selected by means of a feedback system employing
sensors on one or more of the accessories.
[0028] In another embodiment, various engine components have
different temperature and heat capacity characteristics. As an
example, a catalytic converter produces extremely high temperatures
while the engine water jacket has a high heat capacity. The dynamic
behavior of temperature of these engine components additionally
exhibits different time responses, especially on engine starting.
An aspect of this embodiment is the matching of the temperature and
heat capacity characteristics of the individual heat sources,
coupled to the various engine components, to the accessory heat
demands.
[0029] In an embodiment herein disclosed, the working fluid is
heated by means of a plurality of heat-sources in contact with
suitable engine and exhaust system components. The heated working
fluid is pumped, by means of insulated conduits, to a distribution
allocator which, in turn, routes appropriate flows of working fluid
to selected accessories and accessory heaters. The energy-expended
working fluid is returned, via the distribution allocator, to the
heat-sources.
[0030] The distribution allocator comprises, in one embodiment, a
matrix of electrically actuated valves that can perform the
necessary routing. A controller that actuates the valves may be
based on manual inputs, dynamically established priorities and
sensor detected environmental conditions, or a combination of the
same, to control each valve in the matrix. The controller may
include a computer which executes stored programs to set the
correct valve settings. A network of sensors may be distributed at
appropriate monitoring sites and provide real time measurements to
the controller. When heated fluid is used to effectuate heating of
the working fluid, one or more working fluid pumps may be located
at various points in the insulated conduit network to power
circulation. Of course, accessories described herein may be heated
by means of electrical input rather than heated fluid; that is,
accessories may include electrical heaters, rather than, or in
addition to, fluid conduits.
[0031] In a further embodiment, it is recognized that different
engine and exhaust system components can provide differing
temperatures and quantities of heat and have different time-heat
profiles relative to engine starting and operating cycles. The
associated heat-sources can therefore supply working fluids having
differing dynamically varying characteristics. The distribution
allocator, to the extent possible, matches supply characteristics,
of the various sources, to the individual accessory demands.
[0032] Embodiments herein disclosed include a temperature
maintaining compartment in a vehicle comprising: a heat source,
containing a fluid, comprising an input source fluid port and an
output source fluid port; a distribution allocator, containing the
fluid, connected to the heat source by a fluid conduit, comprising
electrically operable fluid valves operatively configured to
interconnect a plurality of input fluid ports and output fluid
ports; a fluid pump operatively, containing the fluid, connected to
the distribution allocator, the fluid pump capable of pumping fluid
through the heat source and into the distribution allocator; and a
gas-absorption refrigerator comprised of a closed-loop flow-through
heated fluid conduit connected to at least one input port and one
output port of the distribution allocator and a cooled fluid
conduit connected to at least one input port and one output port of
the distribution allocator; and a sealable compartment
incorporating temperature sensors and a closed-loop flow-through
fluid conduit connected to at least one input port and one output
port of the distribution, the sensors electrically connected to the
controller.
[0033] Embodiments herein disclosed further include an energy
recovery system in a vehicle comprising: a heat source, containing
a fluid, comprising an input source fluid port and an output source
fluid port; a distribution allocator, containing the fluid,
connected to the heat source by a fluid conduit, comprising
electrically operable fluid valves operatively configured to
interconnect a plurality of input fluid ports and output fluid
ports: a fluid pump operatively, containing the fluid, connected to
the distribution allocator, the fluid pump capable of pumping fluid
through the heat source and into the distribution allocator; and a
rechargeable battery heater, containing the fluid, and having a
closed-loop flow-through conduit connected to at least one input
port and one output port of the allocator.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In an embodiment shown in FIG. 1, there is illustrated an
energy recovery system 10 for an internal combustion engine 20.
Internal combustion engine 20 is powered by the expansion of hot
combustion products of fuel directly combusted within the engine.
As is known, a piston internal combustion engine works by burning
hydrocarbon or hydrogen fuel that presses on a piston, which does
work, such as propelling an automobile; and a jet engine works as
the hot combustion products press on the interior parts of the
nozzle and combustion chamber, directly accelerating the engine
forwards. The engine of such embodiment may be a gasoline or diesel
engine, for example, a two-cycle, four-cycle or a rotary Wankle
engine. Energy recovery system 10 shown in FIG. 1 is configured to
capture and convert specific energy, that is, the amount of energy
per unit mass of the fuel burned in engine 20 into useful work that
is otherwise wasted, for example, in the form of heat that escapes
into the environment.
[0035] In certain internal combustion engines, only a portion
(about 20%) of the total available specific energy in the consumed
fuel is directly converted to mechanical work by the action of the
hot combustion products on engine components such as pistons (which
maybe connected to a shaft, which in turn may do work such as
rotating the wheels on a car--shown in FIG. 2). Of the remaining
portions of energy lost through exhaust gases 30 and through water
heating in the radiator 40 are converted to useful work through the
use of a two-stage turbine 50 as shown in FIG. 1.
[0036] In an aspect of an embodiment, the two-stage turbine 50 is
configured to operate with impellers 57 that are mounted onto a
common shaft 59 which spans two chambers 53 and 55, and which
drives an electric generator 90 as shown in FIG. 1. The impellers
are rotatable by gaseous matter such as the exhaust gases issuing
from exhaust subsystem 30 and steam issuing from exhaust heat
conductor 80, as explained further below. Alternatively, only one
impeller may be employed with rotation by gaseous inflow or steam
alone, or both gaseous inflow and steam. The electricity generated
by generator 90 provides additional energy recovered from the
otherwise would-be wasted heat energy to be put into useful work.
It will be appreciated by those skilled in the art that this
additional energy recovered from waste heat alone can supplant the
energy recovered from kinetic energy dissipated in the braking
system of an automobile, and hence, can be used to enhance the
current hybrid technologies for automobiles. The efficiency of
current internal combustion engines may be significantly improved
thereby, for example, by a factor of two or more.
[0037] Another embodiment of the present invention involves pick-up
of heat and exhaust gas from engine block 22 and engine head 24
(shown separate from the engine block for purposes of illustration)
at points closest to the heat source generated by the combusting
fuel in combustion chambers of engine block 22 in FIG. 1. The main
cooling circuit comprises a primary loop 60 (shown in solid line
arrows) which circulates a coolant (such as water). Exhaust heat
conductor 80 generates steam which enters chamber 53 of the
two-stage turbine 50 to turn shaft 59 connected to electric
generator 90. In one aspect, the electricity from generator 90 may
be used to increase steam production from exhaust heat conductor
80. The expended steam is then collected at condenser 85 where
another phase change occurs from steam to liquid, thus completing
the first cooling loop 60, as shown in FIG. 1. The components and
conduits of the first cooling loop 60, including the condenser 85
and the boiler, containing the condensate may be enclosed by a
liquid jacket through which is circulated heated engine coolant.
During steady state engine operation the coolant temperature is
typically maintained between 90 and 95 degrees C. by means of
thermostatically controlled circulation valves. The steam
condensate will thereby be maintained at approximately 90 degrees
C. before its reintroduction to the boiler. This preheating of the
fluid will improve energy recovery efficiency.
[0038] In another aspect, a secondary loop 65 picks up condensed
steam from condenser 85 (shown in FIG. 1). Exhaust 30 from internal
combustion engine 20 is directed to chamber 55 where the
high-pressure hot gases perform work on the turbine shaft 59, and
leave the system through exhaust conduit 35. A shroud over exhaust
conduit 35 may be configured to augment (using highly thermal
conductive ceramic heat sinks, for example) heat conduction from
the exhaust gases to the secondary loop 65. In one aspect,
secondary loop 65 is connected ultimately to exhaust heat conductor
80. Valves may be used to adjust and balance the coolant flow
through loops 60 and 65.
Relatively cool and low speed exhaust gases may leave the system
through exhaust conduit 35 as shown in FIG. 1.
[0039] Various aspects of certain embodiments of the present
invention may be superimposed schematically over the various known
components of an automobile 100 as depicted in FIG. 2 and the
labeled known components are not described here so as to not
obscure the key aspects of the present invention. The cooling loops
are not shown as they can be arranged in any number of ways to
connect the components of embodiments, for example, engine block
22, exhaust heat conductor 80, condenser 85, radiator 40, two-stage
turbine 50, electric generator 90 and exhaust conduit 35.
Electricity generated by electric generator 90 can be used to power
the drive of the car, or power any component of the car, or the
electricity can be stored in the car battery or secondary, storage
battery 37. It will be understood that the placement of the
disclosed new components can be varied dependent upon factors
affecting space, and safety considerations of an automobile. It
will also be obvious to those skilled in the art that the energy
recovery system disclosed herein can be applied to improve the
efficiency of any engine used to produce useful work.
[0040] In operation, an embodiment of a method of recovering waste
heat energy in an internal combustion engine 20 involves
transferring the heat developed in internal combustion engine 20 to
primary cooling loop 60 at the closest points to the combusting
fuel in the chambers (as, for example, receiving emissions directly
from the exhaust manifold) (see, FIG. 1). The heat carrying coolant
fluid, for example, water in loop 60 is directed to a suitably
designed exhaust heat conductor 80 where the fluid is heated to
generate advantageously pressured steam. Steam is next allowed to
enter two-stage turbine 50 to drive impeller 57 mounted on shaft
59, which in turn drives electric generator 90. The expended steam
is then condensed into liquid through a second phase change in
condenser 85. The coolant liquid then completes the circuit back to
engine block 22 joining primary cooling loop 60. The method may
involve circulating the coolant through the engine block 22 as well
as the engine head 24 to promote most efficient energy recovery
from the combusting fuel in combustion engine 20.
[0041] In an aspect of an embodiment, the method also involves
directing the exhaust gases 30 to the two-stage turbine 50 as shown
in FIG. 1. The high speed exhaust gases are directed to impart
energy to another impeller 57 of the turbine which further enhances
the rotation of shaft 59, which in turn drives the electric
generator 90. Before the expended gases are ejected out into the
environment via an exhaust conduit 35, any remaining heat energy
may be extracted by means of further heat conducting elements and
then transferred appropriately into the system as, for example,
into secondary loop 65. In another embodiment, exhaust gas may pass
first from the turbine exhaust stage and subsequently be channeled
to exhaust heat conductor 80.
EXAMPLE 1
[0042] The exhaust from the exhaust manifold of a single piston
outboard motor is directed to a water jacketed chamber. The
temperature of the exhaust and the water in the jacket is measured
by way of thermocouples during the combustion of 100 ml of regular
gasoline. Steam is generated with maximum temperatures over
400.degree.C. measured in the gas exhaust.
[0043] Other embodiments of the energy recovery system embodiment
of the present invention utilize the heat generated in an internal
combustion engine directly or from components of the exhaust
system. In an embodiment, the heat energy may be efficiently
transported from the various heat sources and the heat loads by
means of a working fluid flowing through insulated conduits.
[0044] There are a variety of heat sources available from the
vehicles engine and associated support components other than heat
generated by, or subsequent to, firing of the internal combustion
engine. For example, a heat source may be an electrical heater
powered by the steam turbine driven generator described above or by
the battery of the vehicle itself. It is also possible to heat the
working fluid directly with the generated steam.
[0045] In a system analogous to a hybrid vehicle propulsion system,
the electrical heater may obtain its power from the steam turbine
driven generator when sufficient steam is available. When steam is
not available to drive the generator, the electrical power for the
heater may be derived from a rechargeable battery. This hybrid
approach permits the system to operate before the engine is
started. Other heat sources may be employed such as heat exchangers
thermally coupled to various engine and exhaust system components
which heat during normal engine operation.
[0046] Referring to FIG. 3, an energy recovery system embodiment
105 is schematically diagrammed and includes a plurality of heat
sources 110 affixed to engine and exhaust system components, a
network of interconnecting insulated conduits 115, a distribution
allocator 120, a working fluid distribution pump 130, and a
plurality of accessory heaters 150 thermally affixed to vehicle
accessories. The heat sources 110 may, include one or more engine
and exhaust system mounted heat exchangers 111, steam
turbine-generator powered electrical fluid heaters 112, battery
powered fluid heaters 113, and steam heated heat exchangers 114.
The distribution allocator 120 includes a matrix of electrically
actuated valves 130 and a controller 140. The working fluid is
heated in the plurality of heat sources 110 and is then pumped to
the distribution allocator 120. The distribution allocator 120
routes the heated working fluid to the appropriate conduits 115 to
supply the plurality of accessories 150. The expended fluid is then
returned from the plurality of accessories 150, back to the
distribution allocator 120, from which it is returned to the heat
sources 110. Each of the distribution allocator valves 130,
operated by the controller 140, may be adjusted within the range
from fully open to fully closed.
[0047] In an embodiment, sensors 160 may be thermally coupled to
the heat sources 110, accessories, and accessory heaters 150 and
operatively connected to report temperatures to the controller 140.
Additional sensors (not shown) may be used to report environmental
temperatures and other conditions to the controller 140
[0048] In an embodiment, as shown in FIG. 4, the controller 140,
may include a controller logic unit 170. The controller logic unit
170 comprises a processor 175, to perform stored control
algorithms, an electronic memory 180 to store executable software
or firmware, and the necessary interfaces 185 to receive
measurements from temperature sensors 160 dispersed throughout the
system and to transmit the computed commands to the controller.
Thus the energy recovery system may be dynamically managed using
closed loop feedback techniques.
[0049] During cold weather operation of vehicles employing internal
combustion engines, liquid fuels, hydraulic and lubrication fluids,
may experience undesirable changes in viscosity and other
properties. The temperature of these fluids also may vary in
response to the variation in engine starting and operating
conditions. In an embodiment, the engine fluids may be heated to
the desirable temperature by means of heating coils located at the
respective fluid supply reservoirs and their supply lines. The
heating coils may be fed by the heated working fluid provided by
the disclosed energy recovery system. As shown in FIG. 5, a fluid
reservoir 300 is shown with its input port 310 and output port 320.
A heating coil 330 is shown affixed to the wall of the fluid
reservoir 300. Heated fluid may be pumped through the heating coil
330 thereby warming the fluid reservoir 300. Temperature sensors
340 may be located at key points of the fluid distribution system
and may telemeter temperatures to the distribution allocator
thereby maintaining the working fluid in its desired temperature
range. Separate heaters may be located at different points in a
given fluid distribution pathway permitting differential heating
input as determined by the distribution allocator.
[0050] Operation of vehicles at temperatures below freezing can
result in the formation of ice on brake system components. Highway
driving, characterized by infrequent application of the brakes, is
especially conducive to brake system icing. In an embodiment a
vehicle brake de-icing system where heated working fluid may be
circulated through conduits thermally coupled to brake shoes and/or
pads and other brake system components thereby reducing the
probability of ice formation. In FIG. 6, a disk brake system 240 is
shown. A brake rotor 200 is fastened to the wheel axle 250. A disk
brake pad 210 is held by a brake caliper mechanism 220. A conduit
230, which may be supplied with heated fluid from the energy
recovery system, is thermally coupled to the caliper 220 whereby
the caliper 220 and the attached disk pad 210 may be heated or
de-iced. Additionally, when brakes are applied, in a manner
analogous to regenerative braking, the frictionally generated heat
may warm the working fluid thereby serving as an additional source
of heat for the energy recovery system.
Statement Regarding Preferred Embodiments
[0051] While the invention has been described with respect to
preferred embodiments, those skilled in the art will readily
appreciate that various changes and/or modifications can be made to
the invention without departing from the spirit or scope of the
invention as defined by the appended claims.
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