Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B33/00—Engines characterised by provision of pumps for charging or scavenging
  • F02B33/44—Passages conducting the charge from the pump to the engine inlet, e.g. reservoirs
  • F02B33/446—Passages conducting the charge from the pump to the engine inlet, e.g. reservoirs having valves for admission of atmospheric air to engine, e.g. at starting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/04—Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
  • F02B37/10—Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump at least one pump being alternatively or simultaneously driven by exhaust and other drive, e.g. by pressurised fluid from a reservoir or an engine-driven pump
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B33/00—Engines characterised by provision of pumps for charging or scavenging
  • F02B33/32—Engines with pumps other than of reciprocating-piston type
  • F02B33/34—Engines with pumps other than of reciprocating-piston type with rotary pumps
  • F02B33/36—Engines with pumps other than of reciprocating-piston type with rotary pumps of positive-displacement type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B33/00—Engines characterised by provision of pumps for charging or scavenging
  • F02B33/32—Engines with pumps other than of reciprocating-piston type
  • F02B33/34—Engines with pumps other than of reciprocating-piston type with rotary pumps
  • F02B33/40—Engines with pumps other than of reciprocating-piston type with rotary pumps of non-positive-displacement type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/04—Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/12—Control of the pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/12—Control of the pumps
  • F02B37/14—Control of the alternation between or the operation of exhaust drive and other drive of a pump, e.g. dependent on speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/12—Control of the pumps
  • F02B37/16—Control of the pumps by bypassing charging air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B39/00—Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
  • F02B39/02—Drives of pumps; Varying pump drive gear ratio
  • F02B39/08—Non-mechanical drives, e.g. fluid drives having variable gear ratio
  • F02B39/10—Non-mechanical drives, e.g. fluid drives having variable gear ratio electric
• • 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

Definitions

• This invention is directed to method and apparatus including both a turbocharger and an electric motor-driven compressor for delivering charge air to a four-cycle internal combustion engine.
• turbochargers to increase power output and decrease fuel consumption in four-cycle internal combustion engines is common practice today. Both spark ignition and diesel engines, use turbochargers to advantage and, in the case of diesel engines, the power output of an engine of a given cylinder displacement can easily be doubled by the addition of turbocharging with aftercooling.
• the turbocharger has gone through decades of development, and modern turbochargers used on high-speed diesel and gasoline engines are low in manufacturing cost, high in efficiency, and very durable commercial products.
• turbocharger utilizes exhaust gas energy that would otherwise be wasted, the imposition of an exhaust gas turbine in the engine exhaust system necessitates raising the average back pressure on the engine cylinders in order to generate sufficient pressure drop across the turbine to generate the power necessary to drive the turbocharger' s compressor.
• This back pressure acts against the upstroke of the piston as it forces residual products of combustion out of the cylinder through the exhaust valves and increases the pumping loss of the engine.
• the level of back pressure caused by high pressure turbocharging of four-cycle engines is very high, even with the use of turbochargers that have relatively high overall efficiency. Any means that might be employed to lower the back pressure caused by the turbocharger turbine can result in significant improvement in engine performance. For example, if a diesel engine requires a pressure ratio of 2.5 times atmospheric pressure to reach the desired rated engine power output, a single turbocharger would impose a back pressure in the exhaust system of approximately two times atmospheric pressure.
• series turbochargers The use of series turbochargers is common today on engines that are rated at high power output. If the two compressors are placed in series combination, the pressure ratio of the charge air is the product of the individual pressure ratios of the compressors. As previously described, die use of series compressors results in their pressure ratios multiplying, so that high supercharge pressure can be supplied to the engine beyond that which a single turbocharger could produce by itself. If, for instance, a highly rated engine requires 4.5 pressure ratio, which is beyond the capability of a single commercial turbocharger, series turbochargers would require the low pressure stage of 2.1 pressure ratio and the high pressure state of 2.15 pressure ratio, the product of which is 4.51 pressure ratio overall. This significantly raises the exhaust gas back pressure.
• the motor-driven compressor may deliver pressurized air to the inlet of the turbine-driven compressor or in parallel thereto to the oudet of the turbine-driven compressor to achieve higher pressure or higher flow, depending upon engine needs.
• One purpose and advantage of this invention is the lowering of engine exhaust back pressure levels by the use of a motor-driven compressor in series with the turbocharger compressor. It is another purpose and advantage of this invention to provide a motor-driven compressor which has the ability to reduce the cost of turbocharging highly rated engines by replacing one turbocharger by a motor-driven compressor, while at the same time improving engine performance due to the resulting lower exhaust back pressure.
• the pressure ratio of the motor-driven compressor need only be 1.5 if the pressure ratio of the turbocharger compressor as a second stage is 3.0.
• the product of the pressure ratios is 4.5, equalling the required pressure ratio of the highly rated engine.
• the engine can be supercharged without imposing back pressure on the exhaust system as does a turbocharger.
• an increase in charge air density is achieved, allowing fuel to be burned more efficiently, with the desirable result of less harmful pollutants emitted into the atmosphere in the engine exhaust.
• Fig. 1 shows one of d e conventional systems for series turbocharging of a four-cycle engine.
• Fig. 2 schematically shows a first preferred embodiment of a charge air system of this invention for a four-cycle engine where a motor-driven compressor is placed in series with a turbocharger compressor.
• Fig. 2A shows a second preferred embodiment of a charge air system of this invention for a four-cycle engine where a motor-driven compressor is placed in series with a motor-assisted turbocharger compressor.
• Fig. 3 shows a d ird preferred embodiment of a charge air system of diis invention for a four-cycle engine where a motor-driven compressor is used to charge die engine.
• Fig. 4 shows a fourth preferred embodiment of a charge air system of this invention for a four-cycle engine where a motor-driven compressor is placed in parallel with a turbocharger compressor.
• Fig. 5 shows a fifth preferred embodiment of a charge air system of d is invention for a four-cycle engine where a motor-driven compressor can be used either in parallel or in series with a turbocharger compressor.
• Fig. 6 shows a sixth preferred embodiment of a charge air system of this invention for a four-cycle engine where a motor-driven compressor can be used eidier in parallel or in series widi a motor-assisted turbocharger compressor.
• a conventional internal combustion engine is shown in schematic cross- section and is generally indicated at 10 in Fig. 1.
• the engine 10 has a cylinder block 12 in which is located cylinder 14.
• die cylinder has an upright axis.
• Piston 16 reciprocates up and down within the cylinder under control of crank 18.
• the crank rotates around die crankshaft axis and is connected to die piston by means of connecting rod 20.
• the crankshaft and connecting rod are housed in crankcase 22, which may contain oil for lubricating the lower part of die engine.
• crankcase 22 which may contain oil for lubricating the lower part of die engine.
• the cylinders in the cylinder block are covered by cylinder head 24.
• the cylinder head has an intake manifold 26 and carries intake valve 28, which controls flow of air or air plus fuel mix to die cylinder.
• the cylinder head 24 also has an exhaust port 30 for each cylinder.
• the exhaust port 30 is controlled by exhaust valve 32.
• the opening and closing of die intake valve and exhaust valve for each cylinder is coordinated with d e movement of the piston by mechanical interconnection of the crankshaft wid die cam shafts which control die valves.
• Fuel is introduced into die cylinder at d e appropriate time dirough fuel injection nozzle 34. In some cases, d e fuel may be delivered to die cylinder as a fuel-air mixture dirough the intake valve.
• centrifugal compressor 36 has its oudet tube 38 connected to the intake port 26.
• centrifugal compressor 40 is a first stage compressor and has an inlet 42 from atmosphere dirough a suitable air filter.
• the oudet tube 44 from compressor 40 is connected to d e inlet of compressor 36, which dius becomes die second stage compressor.
• the use of series compressors results in the multiplying of die pressure ratio.
• the low pressure stage centrifugal compressor 40 would operate at a 2.1 pressure ratio, while die high pressure stage would operate at a 2.15 pressure ratio. This would result in a 4.51 total pressure ratio.
• the series-connected centrifugal compressors are driven by serially connected exhaust gas turbines 46 and 48.
• the exhaust port 30 is connected dirough exhaust pipe 50 to die inlet of first stage turbine 46.
• the oudet of the first stage turbine 46 is connected by exhaust pipe 52 to die inlet of second stage exhaust gas turbine 48.
• the turbine 48 exhausts to atmosphere.
• These series-connected exhaust gas turbines impose a high back pressure on die exhaust port, and diis high back pressure increases d e pumping loss of die engine.
• the exhaust gas turbine 46 is direcdy coupled to drive die centrifugal compressor 36, and d e exhaust gas turbine 48 is direcdy coupled to drive die centrifugal compressor 40.
• the four-cycle internal combustion engine 54 illustrated in Fig. 2 is die same as die engine 10.
• Turbocharger 56 comprises an exhaust gas turbine 58 which is connected to receive hot exhaust gas from die engine and expand it to atmosphere.
• the turbine 58 drives centrifugal compressor 60, which delivers air under pressure to die intake port of engine 54.
• the rotor in die exhaust gas turbine is direcdy connected to drive the rotor in the centrifugal compressor.
• centrifugal compressor 62 has its compressed air oudet connected to die inlet of centrifugal compressor 60 to form a series connected compression system.
• the centrifugal compressor 62 is driven by electric motor 64.
• Electric motor 64 is controlled by a control 67, which applies power from source 69 in response to input signals (generally designated by reference no. 25), such as from a boost pressure sensor and/or a dirotde sensor.
• input signals generally designated by reference no. 25
• die compressors are arranged in series, but die first stage compressor 62 is not driven by an exhaust gas turbine and, tiius, does not raise the exhaust gas back pressure. If one of die series turbochargers is replaced wid a motor-driven compressor, die result is a less complicated mechanical arrangement since only one turbocharger is mounted on die engine exhaust system and die back pressure on die engine is substantially reduced.
• a single turbocharger would impose a back pressure in die exhaust system of approximately two times atmospheric pressure.
• die required pressure ratio of 2.5 can be achieved by producing 1.3 from die motor-driven compressor 62 and 1.92 from die turbocharger compressor 60. Reducing die charging pressure ratio of die turbocharger compressor 60 from 2.5 to 1.92 results in a reduction in exhaust back pressure to approximately 1.5 times atmospheric pressure.
• the motor-driven compressor 60 is controlled by signals from demand, intake manifold pressure, engine speed and die like to yield diese results, plus decreased exhaust gas pollution.
• Fig. 2 The operation of die system shown in Fig. 2 can be enhanced by die addition of a motor-assisted turbocharger as illustrated in Fig. 2A.
• Motor- assisted turbochargers and their operation are described in a co-pending United States patent apphcation, Serial No. 08/680,671 , filed July 16, 1996.
• the turbocharger 156 shown in Fig. 2 A (including turbine 158 and centrifugal compressor 160) has an internal motor-generator 156a mat can be energized by die control means 67 in response to appropriate input signals.
• a boost pressure sensor can be used to send a signal to die control means 67 when die engine is operating at low speed and load.
• d e boost pressure sensor or a d rotde sensor can generate an input signal to control 67 and motor-driven compressor and die motor in die turbocharger are bod energized to provide an increased air supply during die acceleration period.
• a rotor speed signal from die motor 156a in motor- assisted turbocharger 156 is delivered to control 67, and bodi motors are de-energized to eliminate die need for external power.
• the internal motor-generator 156a in d e turbocharger can be de-energized by control 67, while the motor-driven compressor remains energized. This condition corresponds to the series compressor arrangement in Fig. 2 and described previously.
• Fig. 3 shows an internal combustion engine 66 which is die same as die engine 10.
• a centrifugal compressor 68 is connected by intake manifold 70 to die inlet port.
• Compressor 68 is driven by electric motor 72 to supply charge air to the engine.
• a control system 67 is connected to d e motor and to an electric power source 69 so diat die compressor 68 is driven by die motor 72 when a quick engine acceleration is anticipated.
• the motor-driven compressor can be maintained at a pre- determined minimum speed to provide boost pressure in die engine intake manifold at engine idle, or at low load and speed conditions. Thus, a significant amount of air can be present in the cylinder before additional fuel is injected when an engine acceleration is called for.
• the motor-driven compressor 68 is controlled by signals from demand, intake manifold pressure, engine speed and die like to yield these results, plus decreased exhaust gas pollution.
• the series connection of centrifugal compressors is shown in Fig. 2.
• the employment of die compressor 62 at diat point helps, but die air drag through compressor 60 when it is running at low speed sometimes does not permit rapid engine acceleration.
• d e internal combustion engine 74 shown in Fig. 4 has its turbocompressor and its electric motor-driven compressor connected in parallel.
• Turbocompressor 76 receives exhaust gas flow from he exhaust pipe and expands die exhaust gas to atmosphere.
• centrifugal compressor 84 This drives d e centrifugal compressor which delivers air under pressure out dirough tube 78 and reed valve 80 to the intake manifold 82.
• centrifugal compressor 84 is driven by electric motor 86 to deliver air dirough reed valve 88 to manifold 82.
• This arrangement of parallel connected turbocompressor and electric motor compressor improves d e performance of a turbocharged four-cycle engine by compensating for d e time lag of the turbocharger compressor 76 upon sudden dirotde opening, by providing an electrically powered auxiliary compressor 84 which is connected direcdy to d e engine intake duct between die turbocharger compressor and d e engine.
• Backflow of compressed air from die electric compressor dirough die turbocharger is prevented by a pressure activated check valve 80.
• die turbocompressor When sufficient speed is attained by die turbocompressor, its pressure output would overcome die check valve allowing its compressed air to enter die engine manifold.
• Backflow of air from d e turbocompressor dirough the electric compressor is prevented by a second pressure activated check valve 88.
• a suitable motor controller widi pressure sensors, speed sensor and a demand sensor would be employed to provide timely motor switching.
• the engine 90 shown in Fig. 5 is die same as die engine 10.
• the use of an exhaust gas-drive turbine driving an engine driving centrifugal compressor, togedier widi an electric motor-driven compressor connected in series widi die turbocompressor has been described widi respect to Fig. 2.
• the use of an exhaust gas driven turbocompressor widi a parallel connected electric motor-driven compressor has been described widi respect to Fig. 4. It can be understood that, in some operating conditions, a series connection of die air system is desired and, in odier operating conditions, a parallel connection is desired.
• FIG. 5 shows die manner in which ducting is connected so that die output of an electric motor-driven centrifugal compressor is selectively connected in parallel to or in series wid an exhaust-driven turbocompressor.
• the exhaust pipe 92 is connected to die exhaust gas turbine portion 94 of turbocharger 96.
• the centrifugal compressor 98 of d e turbocharger has its pressurized air output connected to intake manifold 100 of engine 90.
• the intake manifold is connected to d e intake port in conventional manner.
• Reed valve 102 is positioned in the intake manifold to permit air flow from die compressor 98 only in the downstream direction toward the intake port.
• Rate sensor 104 is positioned in die manifold to determine the flow rate of air from die compressor 98.
• This rate sensor is used in die control system described below.
• Inlet air to the turbocompressor 98 comes from either of two sources.
• Wye 106 is connected to the turbocompressor inlet.
• One branch of die wye is connected from air cleaner 108 through inlet tube 110 to d e wye.
• Butterfly valve 112 is positioned in inlet tube 110 so that it may be opened and closed.
• Centrifugal compressor 114 is driven by electric motor 116.
• the compressor 114 takes its suction from air cleaner 108 mrough inlet tube 118, which is connected by a tee to inlet tube 110.
• the compressed air output of compressor 114 is directed to oudet tube 120 which has a reed valve 122 tiierein and is connected by means of a tee connection to intake manifold 100 downstream of reed valve 122.
• die compressors 98 and 114 can operate in parallel in providing dieir outputs to intake manifold 100.
• oudet tube 124 is connected as a tee to die oudet tube 120 and is connected to die other branch of d e wye 106.
• Control system 130 receives power from power supply 132 and receives signals 25 including engine speed, intake and exhaust manifold pressures, air flow rates, demands and die like to control the amount of power to motor 116 and to control air actuator 128.
• the rate sensor 104 will signal die motor control 130, and the air actuator 128 will set die synchronized valves 112, 126 to block backflow into d e electric motor- driven compressor and switch off power to d e motor 116 so diat die turbocharger will operate in a normal unassisted mode.
• an electric motor-driven compressor 114 often in combination with a turbocompressor 96, enhances d e operating conditions of a four-cycle internal combustion engine.
• d e motor-driven compressor 114 is energized from control 130 by a low engine speed signal or a low boost pressure signal to provide boost pressure to die engine intake manifold 100 dirough valve 122.
• d e turbocharger compressor oudet pressure opens valve 102 and provides high boost pressure to the engine.
• a boost pressure signal from sensor 104 tells the control 130 to de-energize die motor 116 driving compressor 114 and air back flow dirough die motor-driven compressor 114 is prevented by check valve 122.
• the butterfly valves 126 and 112 remain in die position shown in Fig. 5, depicting parallel operation of he compressors.
• An engine load signal sent to the control 130 causes die butterfly valve 126 to open and simultaneously causes butterfly valve 122 to close.
• the engine intake air flow pati is tiien from the air cleaner 108 dirough duct 118 to compressor 114.
• the compressed air from compressor 114 flows through duct 120, dirough butterfly valve 126 to die intake of the turbocharger compressor 98.
• Super-compressed air then flows from die turbocharger compressor 98 dirough check valve 102 to duct 100, leading to die engine intake manifold.
• Check valve 122 prevents backflow of die super-compressed air into duct 120.
• a low boost pressure signal from sensor 104 sends a signal to d e control 130 and moves die butterfly valves back to die position shown in Fig. 5, which places die compressors in a parallel arrangement in preparation for die next engine acceleration.
• the parallel arrangement of compressors 114 and 98 provides die engine
• Fig. 6 is die same as the system of Fig. 5 except diat turbocharger
• 196 having turbine 194 and compressor 198 has an internal motor- generator 196a diat is operable from power supply 132 by control 130 to enhance the operation of die turbocharger 196.
• control 130 For example, during periods of low engine speed and boost, a signal from sensor 104 activates control 130 to provide sufficient power to d e internal motor-generator 196a to maintain a predetermined turbocharger speed and boost pressure.
• control 130 Upon receiving an input signal indicating a demand for an acceleration in excess of some predetermined acceleration, control 130 supplies higher power to die motor 196a to increase d e turbocharger speed and boost to provide die internal combustion engine 90 with die demanded acceleration.
• Turbocharger rotor speed signals can be provided to control 130 from motor 196a to de-energize the motor 196a when d e turbocharger 196 is providing sufficient compressed air boost from d e exhaust energy of die internal combustion engine.
• die provision and operation of a motor-assisted turbocharger can further enhance, and contribute further flexibihty in die operation of die multiple compressor, series-parallel system of Fig. 5.

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Family Applications (1)

Country Status (7)

Cited By (21)

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Citations (7)

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• 1996
  • 1996-10-28 EP EP96938668A patent/EP0861370A4/en not_active Withdrawn
  • 1996-10-28 BR BR9611556A patent/BR9611556A/pt not_active Application Discontinuation
  • 1996-10-28 KR KR1019980703679A patent/KR19990067651A/ko not_active Application Discontinuation
  • 1996-10-28 JP JP9518877A patent/JP2000500544A/ja active Pending
  • 1996-10-28 AU AU75990/96A patent/AU7599096A/en not_active Abandoned
  • 1996-10-28 WO PCT/US1996/017356 patent/WO1997018388A1/en not_active Application Discontinuation
• 1997
  • 1997-05-13 TW TW086106374A patent/TW328981B/zh active

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