CA1183415A - Method and apparatus for reducing fuel consumption in an internal combustion engine - Google Patents
Method and apparatus for reducing fuel consumption in an internal combustion engineInfo
- Publication number
- CA1183415A CA1183415A CA000396273A CA396273A CA1183415A CA 1183415 A CA1183415 A CA 1183415A CA 000396273 A CA000396273 A CA 000396273A CA 396273 A CA396273 A CA 396273A CA 1183415 A CA1183415 A CA 1183415A
- Authority
- CA
- Canada
- Prior art keywords
- engine
- compressor
- rankine cycle
- power
- output shaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 title claims abstract description 14
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 12
- 230000001603 reducing effect Effects 0.000 title claims abstract description 8
- 230000005540 biological transmission Effects 0.000 claims description 10
- 230000001131 transforming effect Effects 0.000 claims description 6
- 230000000979 retarding effect Effects 0.000 claims description 2
- 230000003213 activating effect Effects 0.000 claims 1
- 230000001186 cumulative effect Effects 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract 1
- 238000011084 recovery Methods 0.000 description 11
- 239000012530 fluid Substances 0.000 description 6
- 239000000110 cooling liquid Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- ZQBFAOFFOQMSGJ-UHFFFAOYSA-N hexafluorobenzene Chemical compound FC1=C(F)C(F)=C(F)C(F)=C1F ZQBFAOFFOQMSGJ-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000010687 lubricating oil Substances 0.000 description 2
- 239000002918 waste heat Substances 0.000 description 2
- OCJBOOLMMGQPQU-UHFFFAOYSA-N 1,4-dichlorobenzene Chemical compound ClC1=CC=C(Cl)C=C1 OCJBOOLMMGQPQU-UHFFFAOYSA-N 0.000 description 1
- RHQDFWAXVIIEBN-UHFFFAOYSA-N Trifluoroethanol Chemical compound OCC(F)(F)F RHQDFWAXVIIEBN-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 244000144983 clutch Species 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229940117389 dichlorobenzene Drugs 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02G—HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS; USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR
- F02G5/00—Profiting from waste heat of combustion engines, not otherwise provided for
- F02G5/02—Profiting from waste heat of exhaust gases
- F02G5/04—Profiting from waste heat of exhaust gases in combination with other waste heat from combustion engines
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Supercharger (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
- Exhaust-Gas Circulating Devices (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Method and apparatus for reducing fuel consumption in an internal combustion engine.
An internal combustion engine (M) is fitted with two diffe-rent means for increasing fuel efficiency : a Rankine cycle circuit for recovering heat energy dissipated by the engi-ne ; and a supercharger (S). The recovered heat energy is transformed into mechanical energy by a turbine (T), and may be applied directly to the engine's output shaft (10).
The supercharger (S) is driven mechanically from the engi-ne's output shaft (10). This arrangement enables the effect of the means for increasing fuel efficiency to be substan-tially cumulative by preventing one of said means from redu-cing the potential gain in efficiency available from the other.
Method and apparatus for reducing fuel consumption in an internal combustion engine.
An internal combustion engine (M) is fitted with two diffe-rent means for increasing fuel efficiency : a Rankine cycle circuit for recovering heat energy dissipated by the engi-ne ; and a supercharger (S). The recovered heat energy is transformed into mechanical energy by a turbine (T), and may be applied directly to the engine's output shaft (10).
The supercharger (S) is driven mechanically from the engi-ne's output shaft (10). This arrangement enables the effect of the means for increasing fuel efficiency to be substan-tially cumulative by preventing one of said means from redu-cing the potential gain in efficiency available from the other.
Description
1 T l55n-35 Method and apparatus for reducing fuel consumption in an internal combustion engine.
Ihe present invention relates to a method and to apparatus ~or reducing fuel consumption in in-ternal combustion engines, and in particular in motor vehicle engines.
BACKGROU~D 0~ THE INVEN'~IO~
Proposals have already been made for recovering the heat energy lost or dissipated by an engine (heat in the exhau~t gasses, in a liquid coolant, or in the lubricating oil) and in transform-ing the heat into another form of energy, e~g. mechanical energy which is then delivered via a transmission to the engine's -output shaft (to increase its driving power) and/or to means for driving engine accessories (e.g. a pump or an alternator). The Rankine thermodynamic cycle has been used ~or this purpose with a working fluid which is made to boil in a boiler by the èxhaust gasses, which then drives a power-producing turbine, which is then condensed and re-heated by exchanging heat with the engine's cooling liquid and its lubricating oil, and which is then returned to the boiler to be made to boil again. Thus9 by recovering and transforming heat energy dissipated by the engine, the total power delivered by the engine for given fuel consumption is increased, or else the fuel consumption for given power output is reduced.
Internal combustion engines have also been fit-ted with means for supercharging the engine with air to greatly increase the power output. This technique ma~es it possible to use smaller cylinder capacity engines which spend a greater than usual proportion o~ running time with the engine delivering a relatively high proportion of its un-supercharged maximum power. When extra power is needed (for sudden acceleration9 overtaking, etc.), the engine is supercharged to increase its maximMm power temporarily. A turbo-compressor is generally used with a turbine that is driven by the exhaust gasses of the ;a1~33~
engine9 and which in turn drives a compressor which feeds compressed air to the engine. Performance equivalent to that of a larger cylinder capacity, un-supercharged engine is thus obtained for lower fuel consumption~ ~he use of a smaller capacity engine also gives rise reductions in cost and in weight.
In order to reduce the engine's fuel consumption still ~urther, attempts ha~e been made to combine these technique~ on the same engine, in particular by providing both a Rankine cycle circuit and a supercharging turbo-compressor driven by the exhaust gasses. However, it has b e e n observed -that the improvement obtained by both of these means ac-ting toge-ther is hardly any better -than the improvement obtained by one or other of these means acting on its own. This can be explained by the fact that each of these means operates to the detriment of the other, each of them being driven by energy that would otherwise have been available to drive the other.
Preferred embodiments of the presen-t invention provide an efficient and cost-effective solution to this problem, in which a supercharger is combined with a circuit for recovering and transforming heat energy dissipated by the engine in such a manner that the improvement obtained by each of these means on its own is cumulative when both are used together. Indeed~ the improvement due to one of the means may even be increased when the other means is used simultaneously.
SUMMARY 0~ THE INVE~TION
The present lnvention provides a method of reducing fuel coneumption in an internal combustion engine of given cylinder capacity, the method consisting in using a Rankine cycle circuit to recover at least par-t of the heat energy dissipated by the engine, to transform the recovered energy into mechanical energy, and then to deliver the mechanical energy to the engine and/or to its accessories, and in using a compressor 3~
driven mechanic~ ly by the engine to supercharge the engine with air whenever it is ~ecessarY t~ boost the maximum power and performance obtainable from the engine to levels normally corresponding to an engine of greater cylinder capacity, thereby also increasing tne heat energy available to the Rankine cycle circuit.
Thus7 according to the invention, -the compressor operates independently from the heat energy recovery circuit in the sense that the energ~ required to drive the compressor is taken from the engine output shaft and not from some point along the energy recovery circuit. The improvements provided by both of these means are cumulative, and it has even been observed that, surprisingly, the improvement available from the heat recovery circuit may actuallg increase when the supercharger is in action, since supercharging increases the exhaust temperature~
and thus increases the efficiency of the heat recovery circuit.
Advantageously, the Rankine cycle is designed to operate at maximum efficiency while the engine is operating at low power output (e.g. from 0% to 50% of full power). In contrast~ the compressor is designed to operate at maximum efficiency when the engine`is operating at high power output (e.g. from 50% to 100% of full power).
'IMaximum efficiency" is used to mean that the compressor is capable of delivering any quantitg of air called for by the engine at some given excess pressure that varies little with engine speed.
The invention also provides apparatus for implementing the method defined above9 the apparatus comprising a Rankine cycle circuit suitable for recovering at least a part of the heat energy dissipated by the engine, for transforming the recovered energy into mechanical energy, and for delivering said mechanical energy direct y to -the engine output shaft and/or to accessories of the engine, wherein the apparatus further 3~
comprises a compressor ~or supercharging the engine with air, said compressor being drlven from -the engine output shaft via a transmission including declutching and/or variable ratio means~
BRIE~ D~SCRIPTION 0~ THE DRAWING
In the following description given by way of example, reference is made to the accompanying drawing in which the sole figure is a diagram showing one embodiment of the invention.
MOR~ DE~AILED DESCRIPTION
In the embodiment shown in the figure, an internal combustion engine M is associated with a supercharger compressor S which is driven by the engine output shaft 10 via a transmission that includes a clutch and/or a reduction gear. The transmission shown in the figure comprises a drive pulley 12 capable of being driven by the engine output shaft ~7i~ a clutch 13, a driven pulley 11, a belt 14 interconnecting the two pulleys, and a reduction gear D1. ~he supercharger compressor ~ is advantageously a volumetric compressor, i.e. a compressor which delivers a quantity of gas that is ~etermined by the swept volume and the speed of rotation,such as a piston, blade or screw type compressor, or else it may be a turbo machine~ e.g.
a peripheral compressor~ The inlet to the supercharger compressor is connected, for example, to the outlet from an air filter ~, and its outlet is connected to the engine's air inle-t pipe (not shown).
A Rankine cycle heat energy recovery and transformation circuit is associated with the engine M. It comprises a boiler 15 having an outlet directly connected to the inlet of an expansion machine such as a -turbine T. The turbine T has a drive sha~t 17 connected to the engine's output shaftlO via a transmission that includee a clutch and/or a step down gear.
The ~ransmission shown in the drawing comprises a drive pulley 18 driving a driven pulley 19 by means of a bel-t 21~ and a clutch 20 3uitable for connecting the driYen pulley 19 to the engine outFut shaft lO~ Means other than the pulleys shown could be used to match the power and speed of the turbine ~ to those of the engine M.
~he outlet from the turbine T is connected to one inlet 22 of a first heat exchanger 23, having a corresponding outlet 24 connected to the inlet 25 of a condenser 26. A pump P~ is used to connect the outlet 27 from the condenser 26 to another inlet 28 of the first heat exchanger 2~ with -the corresponding outlet 29 being connected to one inlet 30 o~ a second heat exchanger 31. The correspond;ng outle-t 32 from the second heat exchanger 31 is connected to one inlet 33 of a third heat exchanger 34 whose corresponding outlet ~5 is connected to the inlet 36 of the boiler 15-A suitable working fluid, e.g~ dichlorobenzene, trifluoro-ethanol, hexafluorobenzene, e-tc.~ circulates round -the circuit which has just been described. In the second heat exchanger 31 the working fluid is heated by the cooling liquid used by the engine M~ A pump P2 pumps the cooling liquid round a circuit 37 passing through said second heat exchanger 31.
The working fluid is heated in the third heat exchanger 34 by the engine's lubricating liquid (generally oil) which includes a circuit 38 passing through the exchanger 34 as shown in the figureO ~he engine's exhaust pipe 39 exhausts into the boiler 15 which includes an outlet 40 for disposing of the exhaust gasses.
Advantageously, the Rankine cycle is designed and optimised in such a manner that it operates at maximum efficiency while the engine is operating at low load, e.g. while the engine is supplying between 0% and 50~ of its maximum power. At higher engine loads, the efficiency of the Rankine cycle drops off such that the extra power provided thereby remains substantiall;y constant, or increases slightly when the ~1~3~ ~
supercharger comes into operation.
~he heat energy recovery circuit which has just been d0scribed opera-tes as follows:
The working fluid is boiled and op-tionally superheated in the boiler 15, and is then sent to the turbine ~ ilhich it drives in rotation. Providlng the clu-tch 20 is engaged, the mechanical energy produced by the turbine T is supplied to the engine drive shaft 10 via the transmission chain comprising the gear D2, the shaft 17, -the pulley 18,the belt 21, the pulley 19 and the clutch 20. ~here are occasions when it is desireable to disengage the clutch~ e.g. when slowing down the vehicle.
~he wor~ing fluid leaving the turbine ~ is sent to the condenser 26, whence it is pumped by the pump P1; pre-heated by passing through the heat exchangers 23, 31 and 3~ in turn and is returned to the boiler 15, where the cycle begins aqain. The appa~atus for superchargil1g the engine by compression of the air admission, and the apparatus for recovering heat energy dissipated by the engine operate independently of each other, since one of them is driven directly from the engine output shaf~,while the other serves to add drive to said shaft.
It is observed that supercharging the engine increases the temperature of the exhaust gasses~ and hence increases the amount of dissipated heat energy that can be recovered by the Rankine cycle appara-tus~ This increases the energy it delivers.
In normal operation of a motor vehicle equipped with apparatus in accordance with the invention, the supercharger compressor operates only for about 5% to 10% of the total time the engine is running, or in other words, the engine is called on to deliver more than about 50% of i-ts maximum power for only abou-t 5% to 10~ o~` the -time that it is running. ~he supercharger can ~ ~ ~ 3 ~
be brou~ht into action when required in conventional manner b~
pressing down the accelerator pedal or by any other appropiate means.
If the engine has ignition tlminy control 40 as shown in the figure, a known device 41 can ke added to the supercharger apparatus to prevent "pinging". "Pinging" is observed as an abnormal rattling noise due to the fuel-air mlxture self-igniting in the ccm~ustion chamkers, anl occurs when the supercharging provides more than akout 30% to 40% excess pressure. Devices already exist for detecting the appearance of pinging an~ to avoid it by aut~,~tically retarding the ignition.
When such a device is combined with a supercharger it becomes possible to provide at least ~0% supercharging at any engine speed, The invention makes it possible for an engine of given cylinder capacity that i8 provided with a supercharger and a Rankine cy~le waste heat energy recovery circuit to provide the same perfvrmance as that which is provided by an engine of larger cylinder capacity but which is not supercharged and which is not provided with waste heat recovery apparatus. At the same time, the smaller capacit~ engine consumes noticeably less fuel.
By way of non-limiting example, reference can be made to the following fuel consumption table for driving a vehicle at a steady 90 km/h and for driving it over the standardised European cycle (ECE). The vehicle used was a private passenger car whose standard version (A) had ignition timing control and a continuously variable gear box, but does not have supercharging or heat 10BS recovery means. Version (B) had Ran~ine cycle heat 10BS recovery apparatus fitted on its own. Version (~) had a supercharger fitted on its own. Version (D) had both a supercharger and a Rankine c~cle heat loss recovery circuit fitted in accordance with the invention. The variou~ versions 3~5 had engines of different cylinder capacities in order to ensure -that all four versions had -the same performance as the s-tandard version (A). ~uel consumption is expressed in grammes per metric horse power hour (g/ch.h).
T A ~ ~ E
st steady European vesion 90 ~m/h ECE cycle ~ _ ~
C 225 3~1 The invention is particularly applicable to internal combustion engines that are used over a wide range o-~ conditions, e~g. in private cars, utility vehicles, etc. It can also be applied to stationary engines that are required to match a varying load, such as in electricity generator sets~
In either case, the engines may be spark ignition engines or compression ignition engines (Diesel cycle engines).
Ihe present invention relates to a method and to apparatus ~or reducing fuel consumption in in-ternal combustion engines, and in particular in motor vehicle engines.
BACKGROU~D 0~ THE INVEN'~IO~
Proposals have already been made for recovering the heat energy lost or dissipated by an engine (heat in the exhau~t gasses, in a liquid coolant, or in the lubricating oil) and in transform-ing the heat into another form of energy, e~g. mechanical energy which is then delivered via a transmission to the engine's -output shaft (to increase its driving power) and/or to means for driving engine accessories (e.g. a pump or an alternator). The Rankine thermodynamic cycle has been used ~or this purpose with a working fluid which is made to boil in a boiler by the èxhaust gasses, which then drives a power-producing turbine, which is then condensed and re-heated by exchanging heat with the engine's cooling liquid and its lubricating oil, and which is then returned to the boiler to be made to boil again. Thus9 by recovering and transforming heat energy dissipated by the engine, the total power delivered by the engine for given fuel consumption is increased, or else the fuel consumption for given power output is reduced.
Internal combustion engines have also been fit-ted with means for supercharging the engine with air to greatly increase the power output. This technique ma~es it possible to use smaller cylinder capacity engines which spend a greater than usual proportion o~ running time with the engine delivering a relatively high proportion of its un-supercharged maximum power. When extra power is needed (for sudden acceleration9 overtaking, etc.), the engine is supercharged to increase its maximMm power temporarily. A turbo-compressor is generally used with a turbine that is driven by the exhaust gasses of the ;a1~33~
engine9 and which in turn drives a compressor which feeds compressed air to the engine. Performance equivalent to that of a larger cylinder capacity, un-supercharged engine is thus obtained for lower fuel consumption~ ~he use of a smaller capacity engine also gives rise reductions in cost and in weight.
In order to reduce the engine's fuel consumption still ~urther, attempts ha~e been made to combine these technique~ on the same engine, in particular by providing both a Rankine cycle circuit and a supercharging turbo-compressor driven by the exhaust gasses. However, it has b e e n observed -that the improvement obtained by both of these means ac-ting toge-ther is hardly any better -than the improvement obtained by one or other of these means acting on its own. This can be explained by the fact that each of these means operates to the detriment of the other, each of them being driven by energy that would otherwise have been available to drive the other.
Preferred embodiments of the presen-t invention provide an efficient and cost-effective solution to this problem, in which a supercharger is combined with a circuit for recovering and transforming heat energy dissipated by the engine in such a manner that the improvement obtained by each of these means on its own is cumulative when both are used together. Indeed~ the improvement due to one of the means may even be increased when the other means is used simultaneously.
SUMMARY 0~ THE INVE~TION
The present lnvention provides a method of reducing fuel coneumption in an internal combustion engine of given cylinder capacity, the method consisting in using a Rankine cycle circuit to recover at least par-t of the heat energy dissipated by the engine, to transform the recovered energy into mechanical energy, and then to deliver the mechanical energy to the engine and/or to its accessories, and in using a compressor 3~
driven mechanic~ ly by the engine to supercharge the engine with air whenever it is ~ecessarY t~ boost the maximum power and performance obtainable from the engine to levels normally corresponding to an engine of greater cylinder capacity, thereby also increasing tne heat energy available to the Rankine cycle circuit.
Thus7 according to the invention, -the compressor operates independently from the heat energy recovery circuit in the sense that the energ~ required to drive the compressor is taken from the engine output shaft and not from some point along the energy recovery circuit. The improvements provided by both of these means are cumulative, and it has even been observed that, surprisingly, the improvement available from the heat recovery circuit may actuallg increase when the supercharger is in action, since supercharging increases the exhaust temperature~
and thus increases the efficiency of the heat recovery circuit.
Advantageously, the Rankine cycle is designed to operate at maximum efficiency while the engine is operating at low power output (e.g. from 0% to 50% of full power). In contrast~ the compressor is designed to operate at maximum efficiency when the engine`is operating at high power output (e.g. from 50% to 100% of full power).
'IMaximum efficiency" is used to mean that the compressor is capable of delivering any quantitg of air called for by the engine at some given excess pressure that varies little with engine speed.
The invention also provides apparatus for implementing the method defined above9 the apparatus comprising a Rankine cycle circuit suitable for recovering at least a part of the heat energy dissipated by the engine, for transforming the recovered energy into mechanical energy, and for delivering said mechanical energy direct y to -the engine output shaft and/or to accessories of the engine, wherein the apparatus further 3~
comprises a compressor ~or supercharging the engine with air, said compressor being drlven from -the engine output shaft via a transmission including declutching and/or variable ratio means~
BRIE~ D~SCRIPTION 0~ THE DRAWING
In the following description given by way of example, reference is made to the accompanying drawing in which the sole figure is a diagram showing one embodiment of the invention.
MOR~ DE~AILED DESCRIPTION
In the embodiment shown in the figure, an internal combustion engine M is associated with a supercharger compressor S which is driven by the engine output shaft 10 via a transmission that includes a clutch and/or a reduction gear. The transmission shown in the figure comprises a drive pulley 12 capable of being driven by the engine output shaft ~7i~ a clutch 13, a driven pulley 11, a belt 14 interconnecting the two pulleys, and a reduction gear D1. ~he supercharger compressor ~ is advantageously a volumetric compressor, i.e. a compressor which delivers a quantity of gas that is ~etermined by the swept volume and the speed of rotation,such as a piston, blade or screw type compressor, or else it may be a turbo machine~ e.g.
a peripheral compressor~ The inlet to the supercharger compressor is connected, for example, to the outlet from an air filter ~, and its outlet is connected to the engine's air inle-t pipe (not shown).
A Rankine cycle heat energy recovery and transformation circuit is associated with the engine M. It comprises a boiler 15 having an outlet directly connected to the inlet of an expansion machine such as a -turbine T. The turbine T has a drive sha~t 17 connected to the engine's output shaftlO via a transmission that includee a clutch and/or a step down gear.
The ~ransmission shown in the drawing comprises a drive pulley 18 driving a driven pulley 19 by means of a bel-t 21~ and a clutch 20 3uitable for connecting the driYen pulley 19 to the engine outFut shaft lO~ Means other than the pulleys shown could be used to match the power and speed of the turbine ~ to those of the engine M.
~he outlet from the turbine T is connected to one inlet 22 of a first heat exchanger 23, having a corresponding outlet 24 connected to the inlet 25 of a condenser 26. A pump P~ is used to connect the outlet 27 from the condenser 26 to another inlet 28 of the first heat exchanger 2~ with -the corresponding outlet 29 being connected to one inlet 30 o~ a second heat exchanger 31. The correspond;ng outle-t 32 from the second heat exchanger 31 is connected to one inlet 33 of a third heat exchanger 34 whose corresponding outlet ~5 is connected to the inlet 36 of the boiler 15-A suitable working fluid, e.g~ dichlorobenzene, trifluoro-ethanol, hexafluorobenzene, e-tc.~ circulates round -the circuit which has just been described. In the second heat exchanger 31 the working fluid is heated by the cooling liquid used by the engine M~ A pump P2 pumps the cooling liquid round a circuit 37 passing through said second heat exchanger 31.
The working fluid is heated in the third heat exchanger 34 by the engine's lubricating liquid (generally oil) which includes a circuit 38 passing through the exchanger 34 as shown in the figureO ~he engine's exhaust pipe 39 exhausts into the boiler 15 which includes an outlet 40 for disposing of the exhaust gasses.
Advantageously, the Rankine cycle is designed and optimised in such a manner that it operates at maximum efficiency while the engine is operating at low load, e.g. while the engine is supplying between 0% and 50~ of its maximum power. At higher engine loads, the efficiency of the Rankine cycle drops off such that the extra power provided thereby remains substantiall;y constant, or increases slightly when the ~1~3~ ~
supercharger comes into operation.
~he heat energy recovery circuit which has just been d0scribed opera-tes as follows:
The working fluid is boiled and op-tionally superheated in the boiler 15, and is then sent to the turbine ~ ilhich it drives in rotation. Providlng the clu-tch 20 is engaged, the mechanical energy produced by the turbine T is supplied to the engine drive shaft 10 via the transmission chain comprising the gear D2, the shaft 17, -the pulley 18,the belt 21, the pulley 19 and the clutch 20. ~here are occasions when it is desireable to disengage the clutch~ e.g. when slowing down the vehicle.
~he wor~ing fluid leaving the turbine ~ is sent to the condenser 26, whence it is pumped by the pump P1; pre-heated by passing through the heat exchangers 23, 31 and 3~ in turn and is returned to the boiler 15, where the cycle begins aqain. The appa~atus for superchargil1g the engine by compression of the air admission, and the apparatus for recovering heat energy dissipated by the engine operate independently of each other, since one of them is driven directly from the engine output shaf~,while the other serves to add drive to said shaft.
It is observed that supercharging the engine increases the temperature of the exhaust gasses~ and hence increases the amount of dissipated heat energy that can be recovered by the Rankine cycle appara-tus~ This increases the energy it delivers.
In normal operation of a motor vehicle equipped with apparatus in accordance with the invention, the supercharger compressor operates only for about 5% to 10% of the total time the engine is running, or in other words, the engine is called on to deliver more than about 50% of i-ts maximum power for only abou-t 5% to 10~ o~` the -time that it is running. ~he supercharger can ~ ~ ~ 3 ~
be brou~ht into action when required in conventional manner b~
pressing down the accelerator pedal or by any other appropiate means.
If the engine has ignition tlminy control 40 as shown in the figure, a known device 41 can ke added to the supercharger apparatus to prevent "pinging". "Pinging" is observed as an abnormal rattling noise due to the fuel-air mlxture self-igniting in the ccm~ustion chamkers, anl occurs when the supercharging provides more than akout 30% to 40% excess pressure. Devices already exist for detecting the appearance of pinging an~ to avoid it by aut~,~tically retarding the ignition.
When such a device is combined with a supercharger it becomes possible to provide at least ~0% supercharging at any engine speed, The invention makes it possible for an engine of given cylinder capacity that i8 provided with a supercharger and a Rankine cy~le waste heat energy recovery circuit to provide the same perfvrmance as that which is provided by an engine of larger cylinder capacity but which is not supercharged and which is not provided with waste heat recovery apparatus. At the same time, the smaller capacit~ engine consumes noticeably less fuel.
By way of non-limiting example, reference can be made to the following fuel consumption table for driving a vehicle at a steady 90 km/h and for driving it over the standardised European cycle (ECE). The vehicle used was a private passenger car whose standard version (A) had ignition timing control and a continuously variable gear box, but does not have supercharging or heat 10BS recovery means. Version (B) had Ran~ine cycle heat 10BS recovery apparatus fitted on its own. Version (~) had a supercharger fitted on its own. Version (D) had both a supercharger and a Rankine c~cle heat loss recovery circuit fitted in accordance with the invention. The variou~ versions 3~5 had engines of different cylinder capacities in order to ensure -that all four versions had -the same performance as the s-tandard version (A). ~uel consumption is expressed in grammes per metric horse power hour (g/ch.h).
T A ~ ~ E
st steady European vesion 90 ~m/h ECE cycle ~ _ ~
C 225 3~1 The invention is particularly applicable to internal combustion engines that are used over a wide range o-~ conditions, e~g. in private cars, utility vehicles, etc. It can also be applied to stationary engines that are required to match a varying load, such as in electricity generator sets~
In either case, the engines may be spark ignition engines or compression ignition engines (Diesel cycle engines).
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Method of reducing fuel consumption in an internal combustion engine of given cylinder volume and having an engine driven compressor for supercharging the engine with air, the method consisting in recovering at least part of the heat energy dissipated by the engine in a Rankine cycle circuit, transforming said recovered heat energy into mechanical energy, delivering the mechanical energy to either the engine or its mechanical accessories, and activating the compressor to supercharge the engine with air whenever it is necessary to boost maximum power and performance to levels normally corresponding to an engine of greater cylinder volume, the power boost also increasing the heat energy available to the Rankine cycle circuit, the circuit having a maximum efficiency when the engine output power is in the range of 0 to 50% of its maximum value.
2. A method according to Claim 1, wherein the engine is supercharged by at least 30%.
3. A method according to Claim 1 and further including the steps of detecting the onset of pinging and then automatically retarding the engine ignition to stop the pinging.
4. A method according to Claim 1, 2 or 3, wherein the energy recovered by the Rankine cycle circuit is delivered in the form of mechanical energy to the engine output shaft, and wherein said delivery is capable of being interrupted, for example during deceleration.
5. Apparatus for reducing the fuel consumption in an internal combustion engine of given cyclinder volume and having a mechanically driven compressor for supercharging the engine, consisting of a Rankine cycle circuit for recovering at least a part of the heat energy dissipated by the engine for transforming the recovered energy into mechanical energy, said circuit including a boiler connected to the engine exhaust, the boiler outlet being connected to and driving a turbine, and means for delivering the output drive of the turbine to either the engine output shaft and/or to engine driven accessories, said engine output shaft having a transmission provided with power interruption means for selectively driving said compressor to supercharge the engine with air, said Rankine cycle circuit having a maximum efficiency when the engine output power is in the range of 0-50% of its maximum value.
6. Apparatus according to Claim 5, wherein the supercharger compressor is a volumetric compressor.
7. Apparatus according to Claim 5, wherein the compressor is designed to match high power output from the engine, e.g. in the range 50% to 100% of the engine's maximum power.
8. Apparatus according to Claim 5, 6 or 7, comprising transmission means between the output from the Rankine cycle circuit and the engine output shaft, wherein said transmission means includes de-clutching means and/or a variable ratio means.
9. Apparatus according to Claim 5, wherein the compressor operates at maximum efficiency in the range of from 50% to 100% of the engine's maximum power.
10. Apparatus according to Claim 5, wherein the means for delivering the turbine drive output consists of a transmission having clutch means for selectively engaging or disengaging the turbine output to said engine output shaft.
11. Apparatus according to Claim 5, and further including means for detecting pinging in the engine's combustion chambers, and means responsive to said means for detecting pinging to adjust ignition advance to prevent said pinging.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8103451A FR2500536A1 (en) | 1981-02-20 | 1981-02-20 | METHOD AND DEVICE FOR REDUCING THE FUEL CONSUMPTION OF AN INTERNAL COMBUSTION ENGINE |
| FR8103451 | 1981-02-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1183415A true CA1183415A (en) | 1985-03-05 |
Family
ID=9255473
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000396273A Expired CA1183415A (en) | 1981-02-20 | 1982-02-15 | Method and apparatus for reducing fuel consumption in an internal combustion engine |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0060159B1 (en) |
| JP (1) | JPS57186008A (en) |
| AT (1) | ATE13930T1 (en) |
| BR (1) | BR8200901A (en) |
| CA (1) | CA1183415A (en) |
| DE (1) | DE3264169D1 (en) |
| ES (1) | ES8304264A1 (en) |
| FR (1) | FR2500536A1 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2540941B1 (en) * | 1983-02-14 | 1987-07-10 | Bertin & Cie | FLUID SEGMENT DEVICE FOR |
| IT1272684B (en) * | 1993-09-27 | 1997-06-26 | Gianluigi Reis | DISSIPATED ENERGY RECOVERY SYSTEM, DURING ITS RUNNING, FROM AN INTERNAL COMBUSTION MOTOR VEHICLE |
| JP2001271609A (en) * | 2000-01-18 | 2001-10-05 | Honda Motor Co Ltd | Waste heat recovery device of internal combustion engine |
| DE10355563A1 (en) * | 2003-11-28 | 2005-06-30 | Daimlerchrysler Ag | Internal combustion engine with a mechanical supercharger and a turbo compound |
| ITMI20062046A1 (en) * | 2006-10-24 | 2008-04-25 | Iveco Motorenforschung Ag | MOTOR SYSTEM WITH HEAT RECOVERY SYSTEM AND RELATIVE HEAT RECOVERY METHOD |
| FR2926598B1 (en) | 2008-01-18 | 2010-02-12 | Peugeot Citroen Automobiles Sa | INTERNAL COMBUSTION ENGINE AND VEHICLE EQUIPPED WITH SUCH ENGINE |
| FR2926599B1 (en) | 2008-01-18 | 2012-06-29 | Peugeot Citroen Automobiles Sa | INTERNAL COMBUSTION ENGINE AND VEHICLE EQUIPPED WITH SUCH ENGINE |
| FR2926600B1 (en) | 2008-01-18 | 2013-02-15 | Peugeot Citroen Automobiles Sa | INTERNAL COMBUSTION ENGINE AND VEHICLE EQUIPPED WITH SUCH ENGINE |
| FR2926601B1 (en) | 2008-01-18 | 2013-02-15 | Peugeot Citroen Automobiles Sa | INTERNAL COMBUSTION ENGINE AND VEHICLE EQUIPPED WITH SUCH ENGINE |
| JP5143056B2 (en) * | 2009-03-02 | 2013-02-13 | 日産自動車株式会社 | Waste heat regeneration system |
| DE102009028467A1 (en) * | 2009-08-12 | 2011-02-17 | Robert Bosch Gmbh | Device for using waste heat |
| JP2011214480A (en) * | 2010-03-31 | 2011-10-27 | Sanden Corp | Waste heat using device of internal combustion engine |
| DE102011013115A1 (en) * | 2011-03-04 | 2012-09-06 | Voith Patent Gmbh | Conveying system for oil and gas |
| JP5999651B2 (en) * | 2012-05-09 | 2016-09-28 | サンデンホールディングス株式会社 | Waste heat recovery device |
| CN104494424B (en) * | 2014-12-24 | 2017-03-29 | 深圳智慧能源技术有限公司 | Axle carrying device driving means, axle carrying device module and dynamical system |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB639234A (en) * | 1947-11-12 | 1950-06-21 | Richard William Bailey | Improvements in and relating to power plant |
| FR1587670A (en) * | 1968-08-08 | 1970-03-27 | ||
| US3888084A (en) * | 1974-05-20 | 1975-06-10 | Gilbert L Hawkins | Thermal recovery system |
| FR2274796A1 (en) * | 1974-06-12 | 1976-01-09 | Raffinage Cie Francaise | Engine ignition timing system based on pinking - sensitive detector on engine supplying actual pinking detector |
| US4031705A (en) * | 1974-11-15 | 1977-06-28 | Berg John W | Auxiliary power system and apparatus |
| FR2345598A1 (en) * | 1976-03-22 | 1977-10-21 | Inst Francais Du Petrole | Two speed drive for supercharger of diesel engine - uses starter motor to drive supercharger on starting engine |
| FR2424411A1 (en) * | 1978-04-26 | 1979-11-23 | Messier Sa | Fuel economiser for IC engine - has heat exchangers in exhaust and oil systems to drive expansion turbine |
-
1981
- 1981-02-20 FR FR8103451A patent/FR2500536A1/en active Granted
-
1982
- 1982-02-12 DE DE8282400255T patent/DE3264169D1/en not_active Expired
- 1982-02-12 AT AT82400255T patent/ATE13930T1/en not_active IP Right Cessation
- 1982-02-12 EP EP82400255A patent/EP0060159B1/en not_active Expired
- 1982-02-15 CA CA000396273A patent/CA1183415A/en not_active Expired
- 1982-02-18 BR BR8200901A patent/BR8200901A/en unknown
- 1982-02-19 ES ES509773A patent/ES8304264A1/en not_active Expired
- 1982-02-20 JP JP57026716A patent/JPS57186008A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57186008A (en) | 1982-11-16 |
| BR8200901A (en) | 1982-12-28 |
| ATE13930T1 (en) | 1985-07-15 |
| ES509773A0 (en) | 1983-02-16 |
| ES8304264A1 (en) | 1983-02-16 |
| FR2500536A1 (en) | 1982-08-27 |
| DE3264169D1 (en) | 1985-07-25 |
| EP0060159B1 (en) | 1985-06-19 |
| FR2500536B1 (en) | 1984-12-14 |
| EP0060159A1 (en) | 1982-09-15 |
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