WO2013118308A1 - Turbocharger excess power recovery device for internal combustion engine - Google Patents

Turbocharger excess power recovery device for internal combustion engine Download PDF

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Publication number
WO2013118308A1
WO2013118308A1 PCT/JP2012/053197 JP2012053197W WO2013118308A1 WO 2013118308 A1 WO2013118308 A1 WO 2013118308A1 JP 2012053197 W JP2012053197 W JP 2012053197W WO 2013118308 A1 WO2013118308 A1 WO 2013118308A1
Authority
WO
WIPO (PCT)
Prior art keywords
hydraulic pump
turbocharger
hydraulic
internal combustion
displacement
Prior art date
Application number
PCT/JP2012/053197
Other languages
French (fr)
Inventor
Motoyuki TAKAHASHI
Original Assignee
Mitsui Engineering & Shipbuilding Co.,Ltd.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsui Engineering & Shipbuilding Co.,Ltd. filed Critical Mitsui Engineering & Shipbuilding Co.,Ltd.
Priority to PCT/JP2012/053197 priority Critical patent/WO2013118308A1/en
Priority to JP2012511471A priority patent/JP5886188B2/en
Publication of WO2013118308A1 publication Critical patent/WO2013118308A1/en

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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
    • F02B41/00—Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power
    • F02B41/02—Engines with prolonged expansion
    • F02B41/10—Engines with prolonged expansion in exhaust turbines
    • 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
    • F02B37/105—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 exhaust drive and pump being both connected through gearing to engine-driven shaft
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H39/00—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution
    • F16H39/02—Rotary fluid gearing using pumps and motors of the volumetric type, i.e. passing a predetermined volume of fluid per revolution with liquid motors at a distance from liquid pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
    • 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

  • the present invention relates to a turbocharger excess power recovery device for an internal combustion engine having a turbocharger.
  • an internal combustion engine such as a diesel engine or a gas engine
  • the turbocharger includes a turbine and a compressor.
  • the turbine is rotationally driven by an exhaust gas of the engine.
  • the compressor is rotated by the turbine to provide an increased charge density for engine output enhancement purposes.
  • Documents 1 and 2 makes effective use of the excess exhaust energy of an engine.
  • This technology is used so that a power generator coupled to a turbocharger ' s compressor through a clutch is rotationally driven by the turbocharger to generate electrical power.
  • the excess exhaust energy of the engine is directly converted to electrical energy and used, for instance, for inboard equipment .
  • a system disclosed, for instance, in Patent Documents 3 and 4 can effectively use nearly all the excess exhaust energy of the engine.
  • a hydraulic pump is coupled to an internal combustion engine's turbocharger through a transmission and rotationally driven by the turbocharger to recover the excess exhaust energy from hydraulic pressure.
  • combustion engine's crankshaft is connected through an oil passage to a hydraulic pump coupled to a turbocharger.
  • Patent Document 3 The invention disclosed in Patent Document 3 is configured so that a hydraulic pump coupled to the internal combustion engine's crankshaft is connected through an oil passage to a hydraulic pump coupled to a turbocharger, and that when the load on the internal combustion engine is low, the hydraulic pressure generated by the hydraulic pump coupled to the crankshaft rotationally drives the
  • turbocharger side hydraulic pump as a hydraulic motor for the purpose of enhancing the turbocharging capability of the turbocharger.
  • either the crankshaft side hydraulic pump or the turbocharger side hydraulic pump needs to be of a variable displacement type in order to let the two hydraulic pumps control the hydraulic flow rate between the two hydraulic pumps, thereby controlling the rotation speed of the turbocharger side hydraulic pump.
  • variable-displacement hydraulic pump integrally includes not only a pump main body for hydraulic pressure generation but also an adjustment mechanism for varying its hydraulic discharge rate. Therefore, the variable-displacement hydraulic pump is extremely larger in size and weight than a fixed-displacement hydraulic pump. In some cases, for example, the variable-displacement hydraulic pump has 2.5 times the weight of a fixed- displacement hydraulic pump.
  • variable-displacement hydraulic pump is of a variable displacement type, it is extremely difficult to install the variable-displacement hydraulic pump in an area around the internal combustion engine, which is crowded, for instance, with many
  • variable-displacement hydraulic pump turns out to be extremely expensive.
  • An object of the present invention is to provide a turbocharger excess power recovery device for an internal combustion engine that makes it possible to install a hydraulic pump in an area around the internal combustion engine with extreme ease, provide significant weight reduction, and reduce the manufacturing cost of the device .
  • a turbocharger excess power recovery device for an internal combustion engine as follows.
  • the device includes: a turbocharger which is rotationally driven by exhaust gas from the internal combustion engine to supply charge air to the internal combustion engine; a first hydraulic pump which is a fixed-displacement hydraulic pump that is coupled to a rotating shaft of the turbocharger and rotates together with the turbocharger; a second hydraulic pump which is a fixed-displacement hydraulic pump that is coupled to a crankshaft of the internal combustion engine and rotates together with the crankshaft; a hydraulic circuit which connects the first hydraulic pump to the second hydraulic pump; a third hydraulic pump which is a variable-displacement hydraulic pump that is provided for the hydraulic circuit to make mutual hydraulic flow rate adjustments between the first and second hydraulic pumps; and an electric motor which is coupled to a rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump.
  • hydraulic pumps can be installed around the internal
  • first and second hydraulic pumps are inexpensive because they are of a fixed-displacement type. Therefore, the manufacturing cost of the device can be reduced.
  • the third hydraulic pump which is a variable- displacement hydraulic pump provided in addition to the first and second hydraulic pumps.
  • a small-size, variable- displacement hydraulic pump may be employed as the third hydraulic pump because the role of the third hydraulic pump is to make the mutual hydraulic flow rate adjustments between the first and second hydraulic pumps.
  • the third hydraulic pump is connected to the first and second hydraulic pumps through the hydraulic circuit, that is, hydraulic piping alone. Therefore, the third hydraulic pump can be installed with an extremely high degree of freedom. This makes it easy to arrange, for instance, accessories around the internal combustion engine.
  • the electric motor which is coupled to the rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump, is included.
  • the hydraulic flow rate can be increased by allowing the electric motor to rotationally drive the third hydraulic pump. Meanwhile, when it is necessary to decrease the hydraulic flow rate, excess power of the turbocharger can be recovered as electrical power by operating the electric motor as a power generator.
  • the turbocharger excess power recovery device as described in the first aspect, further including a controller, which is connected to a displacement adjuster of the third hydraulic pump to vary the displacement of the third hydraulic pump.
  • the controller varies the
  • the mutual hydraulic flow rate adjustments between the first and second hydraulic pumps can be optimally made in accordance with the ever-changing loads on the internal combustion engine.
  • turbocharger excess power recovery device as described in the second aspect, wherein, when the load on the internal combustion engine is low, the
  • controller varies the displacement of the third hydraulic pump in such a manner that the second and third hydraulic pumps cooperate to rotationally drive the first hydraulic pump .
  • the turbocharger coupled to the first hydraulic pump increases its torque so as to optimally turbocharge the internal combustion engine.
  • the first hydraulic pump operates as a hydraulic motor
  • the second and third hydraulic pumps operate as a hydraulic pump.
  • turbocharger excess power recovery device as described in the second or third aspect, wherein, when the load on the internal combustion engine is between medium and substantially normal, the controller varies the displacement of the third hydraulic pump in such a manner that the first and third hydraulic pumps cooperate to rotationally drive the second hydraulic pump.
  • the torque of the second hydraulic pump can be increased to apply additional force to the crankshaft of the internal combustion engine when the load on the
  • the first and third hydraulic pumps operate as a hydraulic pump, whereas the second hydraulic pump operates as a hydraulic motor.
  • turbocharger excess power recovery device as described in any one of the second to fourth aspects, wherein, when the load on the internal combustion engine is between substantially normal and rated, the controller varies the displacement of the third hydraulic pump in such a manner that the first hydraulic pump
  • the controller varies the displacement of the third hydraulic pump in such a manner that the first hydraulic pump rotationally drives the second and third hydraulic pumps while the load on the internal combustion engine is between substantially normal and rated, it is possible to let the electric motor generate electrical power by allowing the third hydraulic pump to rotationally drive the electric motor and apply additional force to the crankshaft of the internal combustion engine when the load on the internal combustion engine is between substantially normal and rated so that the exhaust gas energy for the turbocharger becomes more excess.
  • the excess power of the turbocharger can be optimally recovered.
  • the first hydraulic pump operates as a hydraulic pump
  • the second and third hydraulic pumps operate as a hydraulic motor.
  • turbocharger excess power recovery device as described in any one of the second to fifth aspects, wherein the controller controls the fuel injection to the internal combustion engine.
  • the displacement of the third hydraulic pump can be optimally controlled in accordance with the amount of fuel injection to the internal combustion engine.
  • system simplification can be achieved by integrating the two controllers into a unified whole.
  • turbocharger excess power recovery device as described in any one of the first to sixth aspects, further including a fourth hydraulic pump which supplies hydraulic oil from a tank to the hydraulic circuit.
  • the fourth hydraulic pump is mounted on the rotating shaft of the third hydraulic pump and rotationally driven by the third hydraulic pump.
  • the excess power of the turbocharger can be recovered at a higher level.
  • turbocharger excess power recovery device as described in any one of the second to seventh aspects, wherein the electric motor is connected to a central power distribution unit for a mounting object in which the internal combustion engine is mounted, and receives or supplies electrical power.
  • the turbocharger excess power recovery device includes: a turbocharge which is rotationally driven by exhaust gas from the internal combustion engine to supply charge air to the internal combustion engine; a first hydraulic pump which i a fixed-displacement hydraulic pump that is coupled to a rotating shaft of the turbocharger and rotates together with the turbocharger; a second hydraulic pump which is a fixed-displacement hydraulic pump that is coupled to a crankshaft of the internal combustion engine and rotates together with the crankshaft; a hydraulic circuit which connects the first hydraulic pump to the second hydraulic pump; a third hydraulic pump which is a variable- displacement hydraulic pump that is provided for the hydraulic circuit to make mutual hydraulic flow rate adjustments between the first and second hydraulic pumps; and an electric motor which is coupled to a rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump.
  • the turbocharge excess power recovery device is advantageous in that it makes it extremely easy to dispose the hydraulic pumps around the internal combustion engine, provides significant weight reduction, and reduces the manufacturing cost of the device.
  • Fig. 1 is a block diagram illustrating an example of a turbocharger excess power recovery device for an internal combustion engine according to the present invention.
  • Fig. 2 is a circuit diagram illustrating how a fluid flows in a hydraulic circuit during a normal rotation of the engine shown in Fig. 1.
  • Fig. 3 is a graph illustrating the relationship between the rotation speed of the engine shown in Fig. 1 and the rotation speed of a turbocharger.
  • Fig. 4 is a diagram illustrating the relationship between the operation modes of a first hydraulic pump and the load on the engine shown in Fig. 1.
  • Fig. 5 is a circuit diagram illustrating how the fluid flows in the hydraulic circuit during a reverse rotation of the engine shown in Fig. 1.
  • Fig. 6 is a graph illustrating the relationship between the load on the engine shown in Fig. 1 and
  • Hydraulic pump first hydraulic pump
  • Hydraulic pump (third hydraulic pump)
  • the reference numeral 1 in Fig. 1 denotes a two-cycle propulsion diesel engine (internal combustion engine) that is mounted, for instance, in a vessel (mounting object) .
  • the engine 1 includes a turbocharger 5 which is
  • the turbocharger 5 includes a compressor 6 and a turbine 7.
  • the compressor 6 is coupled to the turbine 7 through a rotating shaft 8.
  • the exhaust gas from the engine 1 rotationally drives the turbine 7, which then rotates the compressor 6. This increases the charge density of the engine, thereby providing an increased engine output.
  • the turbocharger 5 is not always limited to a single- stage type.
  • the engine 1 is not limited to a vessel's engine.
  • the type of the engine 1 is not limited to a two- cycle diesel engine, either.
  • the engine 1 may be a fourcycle diesel engine, a gas engine fueled, for instance, by natural gas or city gas, or any other internal combustion engine.
  • a transmission 9 is coupled to the rotating shaft 8 of the turbocharger 5, and a fixed- displacement hydraulic pump (first hydraulic pump) 10 is coupled to the transmission 9.
  • a transmission 3 is coupled to a crankshaft 2 of the engine 1, and a fixed-displacement hydraulic pump (second hydraulic pump) 11 is coupled to the transmission 3.
  • the hydraulic pump 11 may be directly connected to the crankshaft 2 of the engine 1 without installing the transmission 3.
  • the aforementioned two hydraulic pumps 10 and 11 are incorporated into a hydraulic circuit 20.
  • the output end of the hydraulic pump 10 is connected to the hydraulic pump 11 through an oil passage 21.
  • the input end of the hydraulic pump 10 is connected to the hydraulic pump 11 through an oil passage 21.
  • hydraulic pump 10 is connected to the hydraulic pump 11 through an oil passage 22.
  • a small-size, variable-displacement hydraulic pump (third hydraulic pump) 12 is connected between the two oil passages 21 and 22 through oil passages 23 and 24.
  • the oil passage 23 connects the hydraulic pump 12 to the oil passage 21, whereas the oil passage 24 connects the
  • hydraulic pump 12 to the oil passage 22.
  • the hydraulic pump 12 is connected in parallel to the hydraulic pump 10 and hydraulic pump 11.
  • hydraulic pumps 10, 11 and 12 each operate as a hydraulic pump when rotationally driven by a pump shaft, and operate as a hydraulic motor when rotationally driven by hydraulic pressure.
  • these pumps are simply referred to as the
  • An electric motor 13 is coupled to the variable- displacement hydraulic pump 12.
  • the electric motor 13 not only functions as an electric motor to rotationally drive the hydraulic pump 12, but also functions as a power generator when it is rotationally driven by the hydraulic pump 12. For the sake of naming simplicity, however, it is simply referred to as the electric motor.
  • the electric motor 13 is electrically connected to a central power distribution unit 14 of the vessel. As described later, electrical power can be obtained from the central power distribution unit 14 when the electric motor 13 operates as an electric motor, and the excess power of the turbocharger 5 can be used as the electrical power for the vessel when the electric motor 13 operates as a power generator. If the turbocharger excess power recovery device according to the present invention is used with a vehicle's internal combustion engine, the excess power of the turbocharger 5 can be used as the electrical power for the vehicle (mounting object) .
  • a displacement adjuster for the hydraulic pump 12 may use various adjustment mechanisms such as an inclined plate type or an inclined axis type.
  • a controller 15 is
  • the controller 15 controls the adjustment mechanism to vary the displacement of the hydraulic pump 12.
  • a cooling hydraulic pump 35 is coupled to the
  • hydraulic pump 12 and rotationally driven by the hydraulic pump 12 or by the electric motor 13 coupled to the
  • the cooling hydraulic pump 35 is connected between the two check valves 29 and 30 through a filter 36.
  • a cooling pump safety valve 32 and a heat exchanger 33 are connected between the two check valves 29, 30 and a tank 34 through an oil passage 37.
  • the outlet of the hydraulically-operated changeover valve 25 is connected to the tank 34 through a safety valve 31, the oil passage 37, and the heat exchanger 33.
  • the turbocharger excess power recovery device uses the hydraulic pressure generated by the hydraulic pump 11 coupled to the crankshaft 2 of the engine 1 to
  • turbocharger 5 is higher than that generated by the exhaust gas alone. As a result, the turbocharger 5 increases its speed and provides increased turbocharging for the engine 1.
  • Fig. 3 shows the relationship between the rotation speed of the engine 1 and the rotation speed of the
  • the solid line in this graph represents a virtual operation curve that is exhibited by the hydraulic pump 10 and hydraulic pump 11 when the hydraulic pump 12 is not installed.
  • the virtual operation curve is almost
  • the broken line represents the actual rotation speed of the turbocharger 5 that prevails at various rotation speeds of the engine 1 when the hydraulic pump 12 is installed.
  • Point A in Fig. 3 indicates a state where no flow rate adjustment is made by the hydraulic pump 12 in its actual operation state.
  • the two fixed- displacement hydraulic pumps 10 and 11 have the same flow rate in their actual operation states.
  • the hydraulic pump 12 is electrically driven by the
  • point A is set close to a normal-load operation region within which the engine load ranges from 75% to 85%. Obviously, point A need not always be set close to the normal-load operation region.
  • the controller 15 which regulates the fuel injection amount of the engine 1 shown in Fig. 1, varies the displacement of the variable- displacement hydraulic pump 12 to let the electric motor 13 rotationally drive the hydraulic pump 12. This causes the two hydraulic pumps 11 and 12 to increase the torque for the turbocharger 5 as needed during a low-load operation including a startup.
  • the hydraulic pump 10 operates as a hydraulic motor during a low-load operation as shown in Fig. 4.
  • the central power distribution unit 14 of the vessel shown in Fig. 1 supplies electrical power to the electric motor 13.
  • the cooling hydraulic pump 35 is rotationally driven by the electric motor 13 to suction hydraulic oil from the tank 34 and supply cooled hydraulic oil to the oil passages 21 and 22 through the two check valves 29 and 30. If the
  • hydraulically-operated changeover valve 25 and the safety valve 31 allow the hydraulic fluid to be cooled by the oil passage 37 and heat exchanger 33 and then returned to the tank 34.
  • the controller 15 shown in Fig. 1 varies the displacement of the variable-displacement hydraulic pump 12, thereby causing the hydraulic pump 11 coupled to the crankshaft 2 to be rotationally driven by hydraulic pressure that is delivered from the hydraulic pump 10 due to the torque of the turbocharger 5.
  • the hydraulic pump 10 changes its operation mode to operate as a hydraulic pump when the load is 40 to 50% or higher, as shown in Fig. 4. Meanwhile, the hydraulic pump 12 is rotationally driven by the electric motor 13 until the load is near a normal level, as shown in Fig. 3.
  • hydraulic pump 12 then increases the rotation speed of the hydraulic pump 11 coupled to the crankshaft 2. It should be noted that the hydraulic pump 10 does not always have to switch from a motor mode to a pump mode when the load is between 40% and 50% as is the case with the engine 1.
  • the controller 15 shown in Fig. 1 varies the displacement of the variable-displacement hydraulic pump 12 in such a manner that the two hydraulic pumps 11 and 12 are
  • the hydraulic pump 11 provides auxiliary drive for the engine 1 through the crankshaft 2, while the hydraulic pump 12 operates as a hydraulic motor and rotationally drives the electric motor 13 as a power generator. Electrical power generated by the electric motor 13 is supplied to the vessel's central power
  • the controller 15 shown in Fig. 1 opens the open/close solenoid valve 28 when the engine 1 rotates in the reverse direction.
  • the hydraulic circuit 20 therefore, a hydraulic circuit for circulation between the hydraulic pump 10 and the open/close solenoid valve 28 and a hydraulic circuit for circulation between the
  • the controller 15 varies the displacement of the variable-displacement hydraulic pump 12 in such a manner that the two hydraulic pumps 11 and 12 are rotationally driven by the hydraulic pressure delivered from the hydraulic pump 10 due to the torque of the turbocharger 5, as is the case with the aforementioned normal operation.
  • the hydraulic pump 11 provides auxiliary drive for the engine 1 through the crankshaft 2, while the hydraulic pump 12 rotationally drives the electric motor 13 and supplies motor-generated electrical power to the vessel's central power distribution unit 14 shown in Fig. [0059]
  • Fig. 6 the solid line shows the relationship between the load on the engine 1 in which the turbocharger excess power recovery device according to the present invention is incorporated and the scavenging air-pressure, whereas the broken line is a virtual curve showing the relationship between the load on the engine 1 in which the turbocharger excess power recovery device according to the present invention is not incorporated and the scavenging air-pressure .
  • the engine 1 in which the turbocharger excess power recovery device according to the present invention is incorporated differs from the engine 1 in which the turbocharger excess power recovery device according to the present invention is not incorporated in that the scavenging air-pressure is reduced in the whole engine load region.
  • the engine in which the turbocharger excess power recovery device is not incorporated discards excess exhaust gas which is not consumed by the
  • turbocharger by discharging it to the atmosphere through a bypass valve or the like.
  • the engine 1 in which the turbocharger excess power recovery device according to the present invention is incorporated allows the hydraulic pump 10 to generate hydraulic pressure in accordance with the decrease in the scavenging air-pressure. It means that excess exhaust gas energy is effectively used.
  • the hydraulic pump 10 coupled to the rotating shaft 8 of the turbocharger 5 and the hydraulic pump 11 coupled to the crankshaft 2 of the engine 1 are both of the fixed-displacement type. This makes it possible to reduce the sizes of the hydraulic pumps 10 and 11, make it easy to dispose the other
  • the mutual hydraulic flow rate adjustments between the hydraulic pump 10 and the hydraulic pump 11 are made by the hydraulic pump 12 which is a variable-displacement hydraulic pump employed in addition to the fixed- displacement hydraulic pumps 10 and 11.
  • the hydraulic pump 12 merely makes the mutual hydraulic flow rate adjustments between the hydraulic pumps 10 and 11. Therefore, a small- size, variable-displacement hydraulic pump is used as the hydraulic pump 12. It is extremely advantageous in terms, for instance, of cost as compared to conventional, large- size and variable-displacement hydraulic pumps.
  • variable-displacement hydraulic pump 12 can be installed with an extremely high degree of freedom. This makes it easy to arrange, for instance, accessories around the engine 1.
  • the included electric motor 13 rotates together with the hydraulic pump 12 as it is coupled to the rotating shaft of the hydraulic pump 12. Therefore, when it is necessary to increase the hydraulic flow rate in an oil passage with the hydraulic pump 12, the hydraulic flow rate can be increased by allowing the electric motor 13 to rotationally drive the hydraulic pump 12. When, on the other hand, it is necessary to decrease the hydraulic flow rate, the electric motor 13 can be operated as a power generator to recover the excess power of the turbocharger 5 as electrical power.
  • the included controller 15 is connected to the displacement adjuster of the hydraulic pump 12 to vary the displacement of the hydraulic pump 12.
  • the controller 15 varies the displacement of the hydraulic pump 12 in
  • the controller 15 varies the displacement of the hydraulic pump 12 in such a manner that the hydraulic pump 11 rotationally driven by the crankshaft 2 of the engine 1 and the
  • variable-displacement hydraulic pump 12 rotationally driven by the electric motor 13 cooperate to rotationally drive the hydraulic pump 10 coupled to the turbocharger 5.
  • the two hydraulic pumps 11 and 12 increase the torque of the hydraulic pump 10 coupled to the turbocharger 5. This makes it possible to provide optimum turbocharging for the engine 1.
  • the controller 15 varies the displacement of the variable-displacement hydraulic pump 12 in such a manner that the hydraulic pump 11 coupled to the crankshaft 2 of the engine 1 and the variable- displacement hydraulic pump 12 are rotationally driven by the hydraulic pump 10 coupled to the turbocharger 5.
  • the hydraulic pump 12 can rotationally drive the electric motor 13 to let the electric motor 13 generate electrical power. This makes it possible to optimally recover the excess power of the turbocharger 5.
  • controller 15 controls the fuel injection of the engine 1. Therefore, the displacement of the variable-displacement hydraulic pump 12 can be
  • simplification can be achieved by allowing the single controller 15 to control the fuel injection of the engine 1 and the operation of the hydraulic pump 12.
  • variable-displacement hydraulic pump 12 and rotationally driven by the hydraulic pump 12. Therefore, it is not necessary to additionally install a power source for the cooling hydraulic pump 35. In addition, the excess power of the turbocharger 5 can be recovered at a higher level.

Abstract

The turbocharger excess power recovery device for an internal combustion engine includes a turbocharger (5) which supplies charge air to the internal combustion engine (1); a first hydraulic pump (10) which is a fixed- displacement hydraulic pump coupled to a rotating shaft of the turbocharger; a second hydraulic pump (11) which is a fixed-displacement hydraulic pump coupled to a crankshaft (2) of the internal combustion engine; a hydraulic circuit (20) which connects the first hydraulic pump to the second hydraulic pump; a third hydraulic pump (12) which is a variable-displacement hydraulic pump that is provided for the hydraulic circuit to make mutual hydraulic flow rate adjustments between the first hydraulic pump and the second hydraulic pump; and an electric motor (13) which is coupled to a rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump.

Description

Description
Turbocharger Excess Power Recovery Device for Internal
Combustion Engine
Technical Field
[0001]
The present invention relates to a turbocharger excess power recovery device for an internal combustion engine having a turbocharger.
Background Art
[0002]
Conventionally, an internal combustion engine, such as a diesel engine or a gas engine, uses a turbocharger to increase the engine's output. The turbocharger includes a turbine and a compressor. The turbine is rotationally driven by an exhaust gas of the engine. The compressor is rotated by the turbine to provide an increased charge density for engine output enhancement purposes.
[0003]
However, even in a situation where the turbocharger is installed to make effective use of exhaust energy, the exhaust energy becomes excessive when, for instance, the load on the engine is high. Therefore, it is strongly demanded, from the viewpoint of fuel economy and
environmental protection, that the excess exhaust energy be effectively used.
[0004]
A technology disclosed, for instance, in Patent
Documents 1 and 2 makes effective use of the excess exhaust energy of an engine. This technology is used so that a power generator coupled to a turbocharger ' s compressor through a clutch is rotationally driven by the turbocharger to generate electrical power. In this instance, the excess exhaust energy of the engine is directly converted to electrical energy and used, for instance, for inboard equipment .
[0005]
However, when, for instance, inboard power
consumption is low, the engine's exhaust energy cannot be fully utilized simply by coupling the power generator to the turbocharger for using the resultant electrical energy. Thus, it is imperative, from the viewpoint of fuel economy and environmental protection, that all the excess exhaust energy of the engine be effectively used.
[0006]
A system disclosed, for instance, in Patent Documents 3 and 4 can effectively use nearly all the excess exhaust energy of the engine. In this system, a hydraulic pump is coupled to an internal combustion engine's turbocharger through a transmission and rotationally driven by the turbocharger to recover the excess exhaust energy from hydraulic pressure.
[0007]
In an invention disclosed in Patent Document 3, in particular, a hydraulic pump coupled to an internal
combustion engine's crankshaft is connected through an oil passage to a hydraulic pump coupled to a turbocharger.
When the load on the internal combustion engine is low, the hydraulic pressure generated by the hydraulic pump coupled to the crankshaft rotationally drives the turbocharger side hydraulic pump as a hydraulic motor for the purpose of enhancing the turbocharging capability of the turbocharger. [Prior Art Documents]
[Patent Document 1] JP-UM-A-61-200423
[Patent Document 2] JP-A-2004-346803
[Patent Document 3] JP-A-2006-242051
[Patent Document 4] JP-A-2008-111384
Disclosure of Invention
Technical Problem [0008]
The invention disclosed in Patent Document 3 is configured so that a hydraulic pump coupled to the internal combustion engine's crankshaft is connected through an oil passage to a hydraulic pump coupled to a turbocharger, and that when the load on the internal combustion engine is low, the hydraulic pressure generated by the hydraulic pump coupled to the crankshaft rotationally drives the
turbocharger side hydraulic pump as a hydraulic motor for the purpose of enhancing the turbocharging capability of the turbocharger. In the invention, either the crankshaft side hydraulic pump or the turbocharger side hydraulic pump needs to be of a variable displacement type in order to let the two hydraulic pumps control the hydraulic flow rate between the two hydraulic pumps, thereby controlling the rotation speed of the turbocharger side hydraulic pump.
[0009]
However, the variable-displacement hydraulic pump integrally includes not only a pump main body for hydraulic pressure generation but also an adjustment mechanism for varying its hydraulic discharge rate. Therefore, the variable-displacement hydraulic pump is extremely larger in size and weight than a fixed-displacement hydraulic pump. In some cases, for example, the variable-displacement hydraulic pump has 2.5 times the weight of a fixed- displacement hydraulic pump.
[0010]
In the invention disclosed in Patent Document 3, in particular, one hydraulic pump is mechanically coupled to the crankshaft of the internal combustion engine whereas the other hydraulic pump is mechanically coupled to the turbocharger of the internal combustion engine through a transmission. Therefore, no matter which of the two
hydraulic pumps is of a variable displacement type, it is extremely difficult to install the variable-displacement hydraulic pump in an area around the internal combustion engine, which is crowded, for instance, with many
accessories. In addition, the total weight is extremely increased as described earlier. Further, when a variable- displacement hydraulic pump is used, its adjustment
mechanism is sized to match its discharge rate.
Consequently, the variable-displacement hydraulic pump turns out to be extremely expensive.
[0011]
The present invention has been made to solve the above problem. An object of the present invention is to provide a turbocharger excess power recovery device for an internal combustion engine that makes it possible to install a hydraulic pump in an area around the internal combustion engine with extreme ease, provide significant weight reduction, and reduce the manufacturing cost of the device .
Technical Solution
[0012]
In solving the above problem, according to a first aspect of the present invention, there is provided a turbocharger excess power recovery device for an internal combustion engine as follows. The device includes: a turbocharger which is rotationally driven by exhaust gas from the internal combustion engine to supply charge air to the internal combustion engine; a first hydraulic pump which is a fixed-displacement hydraulic pump that is coupled to a rotating shaft of the turbocharger and rotates together with the turbocharger; a second hydraulic pump which is a fixed-displacement hydraulic pump that is coupled to a crankshaft of the internal combustion engine and rotates together with the crankshaft; a hydraulic circuit which connects the first hydraulic pump to the second hydraulic pump; a third hydraulic pump which is a variable-displacement hydraulic pump that is provided for the hydraulic circuit to make mutual hydraulic flow rate adjustments between the first and second hydraulic pumps; and an electric motor which is coupled to a rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump.
[0013]
When the first hydraulic pump which is coupled to the rotating shaft of the turbocharger, and the second
hydraulic pump which is coupled to the crankshaft of the internal combustion engine, are of a fixed-displacement type as described above, the sizes of the first and second hydraulic pumps can be made small. Therefore, the
hydraulic pumps can be installed around the internal
combustion engine with extreme ease. Further, significant weight reduction can be provided. In addition, the first and second hydraulic pumps are inexpensive because they are of a fixed-displacement type. Therefore, the manufacturing cost of the device can be reduced.
[0014]
Furthermore, the mutual hydraulic flow rate
adjustments between the first and second hydraulic pumps are made by the third hydraulic pump which is a variable- displacement hydraulic pump provided in addition to the first and second hydraulic pumps. A small-size, variable- displacement hydraulic pump may be employed as the third hydraulic pump because the role of the third hydraulic pump is to make the mutual hydraulic flow rate adjustments between the first and second hydraulic pumps. This
provides a significant advantage in terms of cost. In addition, the third hydraulic pump is connected to the first and second hydraulic pumps through the hydraulic circuit, that is, hydraulic piping alone. Therefore, the third hydraulic pump can be installed with an extremely high degree of freedom. This makes it easy to arrange, for instance, accessories around the internal combustion engine.
[0015]
Moreover, the electric motor which is coupled to the rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump, is included.
Therefore, when it is necessary to increase the hydraulic flow rate in an oil passage with the third hydraulic pump, the hydraulic flow rate can be increased by allowing the electric motor to rotationally drive the third hydraulic pump. Meanwhile, when it is necessary to decrease the hydraulic flow rate, excess power of the turbocharger can be recovered as electrical power by operating the electric motor as a power generator.
[0016]
According to a second aspect of the present invention, there is provided the turbocharger excess power recovery device as described in the first aspect, further including a controller, which is connected to a displacement adjuster of the third hydraulic pump to vary the displacement of the third hydraulic pump. The controller varies the
displacement of the third hydraulic pump in accordance with loads on the internal combustion engine.
[0017]
When the controller connected to the displacement adjuster of the third hydraulic pump varies the
displacement of the third hydraulic pump in accordance with the loads on the internal combustion engine as described above, the mutual hydraulic flow rate adjustments between the first and second hydraulic pumps can be optimally made in accordance with the ever-changing loads on the internal combustion engine.
[0018]
According to a third aspect of the present invention, there is provided the turbocharger excess power recovery device as described in the second aspect, wherein, when the load on the internal combustion engine is low, the
controller varies the displacement of the third hydraulic pump in such a manner that the second and third hydraulic pumps cooperate to rotationally drive the first hydraulic pump .
[0019]
When the displacement of the third hydraulic pump is varied as described above so that the second and third hydraulic pumps cooperate to rotationally drive the first hydraulic pump in a situation where exhaust gas energy is insufficient while the load on the internal combustion engine is low, the turbocharger coupled to the first hydraulic pump increases its torque so as to optimally turbocharge the internal combustion engine. In this instance, the first hydraulic pump operates as a hydraulic motor, whereas the second and third hydraulic pumps operate as a hydraulic pump.
[0020]
According to a fourth aspect of the present invention, there is provided the turbocharger excess power recovery device as described in the second or third aspect, wherein, when the load on the internal combustion engine is between medium and substantially normal, the controller varies the displacement of the third hydraulic pump in such a manner that the first and third hydraulic pumps cooperate to rotationally drive the second hydraulic pump.
[0021]
As far as the controller varies the displacement of the third hydraulic pump in such a manner that the first and third hydraulic pumps cooperate to rotationally drive the second hydraulic pump while the load on the internal combustion engine is between medium and substantially normal, the torque of the second hydraulic pump can be increased to apply additional force to the crankshaft of the internal combustion engine when the load on the
internal combustion engine is medium or higher so that the exhaust gas energy begins to become excess. This results in improved fuel economy. In this instance, the first and third hydraulic pumps operate as a hydraulic pump, whereas the second hydraulic pump operates as a hydraulic motor. [0022]
According to a fifth aspect of the present invention, there is provided the turbocharger excess power recovery device as described in any one of the second to fourth aspects, wherein, when the load on the internal combustion engine is between substantially normal and rated, the controller varies the displacement of the third hydraulic pump in such a manner that the first hydraulic pump
rotationally drives the second and third hydraulic pumps.
[0023]
As far as the controller varies the displacement of the third hydraulic pump in such a manner that the first hydraulic pump rotationally drives the second and third hydraulic pumps while the load on the internal combustion engine is between substantially normal and rated, it is possible to let the electric motor generate electrical power by allowing the third hydraulic pump to rotationally drive the electric motor and apply additional force to the crankshaft of the internal combustion engine when the load on the internal combustion engine is between substantially normal and rated so that the exhaust gas energy for the turbocharger becomes more excess. This results in
improved fuel economy. In the above-described manner, the excess power of the turbocharger can be optimally recovered. In this instance, the first hydraulic pump operates as a hydraulic pump, whereas the second and third hydraulic pumps operate as a hydraulic motor.
[0024]
According to a sixth aspect of the present invention, there is provided the turbocharger excess power recovery device as described in any one of the second to fifth aspects, wherein the controller controls the fuel injection to the internal combustion engine. When the controller's function of controlling the third hydraulic pump is
incorporated into a controller that controls the fuel injection to the internal combustion engine, the displacement of the third hydraulic pump can be optimally controlled in accordance with the amount of fuel injection to the internal combustion engine. In addition, system simplification can be achieved by integrating the two controllers into a unified whole.
[0025]
According to a seventh aspect of the present
invention, there is provided the turbocharger excess power recovery device as described in any one of the first to sixth aspects, further including a fourth hydraulic pump which supplies hydraulic oil from a tank to the hydraulic circuit. The fourth hydraulic pump is mounted on the rotating shaft of the third hydraulic pump and rotationally driven by the third hydraulic pump.
[0026]
When the fourth hydraulic pump which supplies
hydraulic oil from the tank to the hydraulic circuit is rotationally driven by the third hydraulic pump as
described above, it is not necessary to additionally install a power source for the fourth hydraulic pump.
Further, the excess power of the turbocharger can be recovered at a higher level.
[0027]
According to an eighth aspect of the present
invention, there is provided the turbocharger excess power recovery device as described in any one of the second to seventh aspects, wherein the electric motor is connected to a central power distribution unit for a mounting object in which the internal combustion engine is mounted, and receives or supplies electrical power.
[0028]
When the input and output of the electric motor are connected to the central power distribution unit for a vessel, a vehicle, or other mounting object in which the internal combustion engine is mounted, it is possible to acquire electrical power from the central power distribution unit when the electric motor operates as a motor, and use the excess power of the turbocharger as electrical power for the mounting object when the electric motor operates as a power generator.
Advantageous Effects
[0029]
The turbocharger excess power recovery device according to the present invention includes: a turbocharge which is rotationally driven by exhaust gas from the internal combustion engine to supply charge air to the internal combustion engine; a first hydraulic pump which i a fixed-displacement hydraulic pump that is coupled to a rotating shaft of the turbocharger and rotates together with the turbocharger; a second hydraulic pump which is a fixed-displacement hydraulic pump that is coupled to a crankshaft of the internal combustion engine and rotates together with the crankshaft; a hydraulic circuit which connects the first hydraulic pump to the second hydraulic pump; a third hydraulic pump which is a variable- displacement hydraulic pump that is provided for the hydraulic circuit to make mutual hydraulic flow rate adjustments between the first and second hydraulic pumps; and an electric motor which is coupled to a rotating shaft of the third hydraulic pump and rotates together with the third hydraulic pump.
[0030]
Being configured as described above, the turbocharge excess power recovery device according to the present invention is advantageous in that it makes it extremely easy to dispose the hydraulic pumps around the internal combustion engine, provides significant weight reduction, and reduces the manufacturing cost of the device.
Brief Description of Drawings
[0031] Fig. 1 is a block diagram illustrating an example of a turbocharger excess power recovery device for an internal combustion engine according to the present invention.
Fig. 2 is a circuit diagram illustrating how a fluid flows in a hydraulic circuit during a normal rotation of the engine shown in Fig. 1.
Fig. 3 is a graph illustrating the relationship between the rotation speed of the engine shown in Fig. 1 and the rotation speed of a turbocharger.
Fig. 4 is a diagram illustrating the relationship between the operation modes of a first hydraulic pump and the load on the engine shown in Fig. 1.
Fig. 5 is a circuit diagram illustrating how the fluid flows in the hydraulic circuit during a reverse rotation of the engine shown in Fig. 1.
Fig. 6 is a graph illustrating the relationship between the load on the engine shown in Fig. 1 and
scavenging air-pressure.
Explanation of Reference
I ... Engine
2... Crankshaft
3... Transmission
5... Turbocharger
6... Compressor
7... Turbine
8... Rotating shaft
9... Transmission
10... Hydraulic pump (first hydraulic pump)
II... Hydraulic pump (second hydraulic pump)
12... Hydraulic pump (third hydraulic pump)
13... Electric motor
14... Central power distribution unit
15... Controller
20... Hydraulic circuit
21, 22, 23, 24... Oil passage 25... Changeover valve
26, 27... Safety valve
28... Open/close solenoid valve
29, 30... Check valve
31... Safety valve
32... Safety valve
33... Heat exchanger
34... Tank
35... Cooling hydraulic pump (fourth pump)
36... Filter
37... Oil passage
Best Mode for Carrying Out the Invention
[0032]
An embodiment of a turbocharger excess power recovery device for an internal combustion engine according to the present invention will now be described in detail with reference to Figs. 1 to 6.
[0033]
The reference numeral 1 in Fig. 1 denotes a two-cycle propulsion diesel engine (internal combustion engine) that is mounted, for instance, in a vessel (mounting object) . The engine 1 includes a turbocharger 5 which is
rotationally driven by exhaust gas from the engine 1 to supply charge air to the engine 1.
[0034]
The turbocharger 5 includes a compressor 6 and a turbine 7. The compressor 6 is coupled to the turbine 7 through a rotating shaft 8. The exhaust gas from the engine 1 rotationally drives the turbine 7, which then rotates the compressor 6. This increases the charge density of the engine, thereby providing an increased engine output.
[0035]
The turbocharger 5 is not always limited to a single- stage type. The engine 1 is not limited to a vessel's engine. The type of the engine 1 is not limited to a two- cycle diesel engine, either. The engine 1 may be a fourcycle diesel engine, a gas engine fueled, for instance, by natural gas or city gas, or any other internal combustion engine.
[0036]
As shown in Fig. 1, a transmission 9 is coupled to the rotating shaft 8 of the turbocharger 5, and a fixed- displacement hydraulic pump (first hydraulic pump) 10 is coupled to the transmission 9. A transmission 3 is coupled to a crankshaft 2 of the engine 1, and a fixed-displacement hydraulic pump (second hydraulic pump) 11 is coupled to the transmission 3. Obviously, the hydraulic pump 11 may be directly connected to the crankshaft 2 of the engine 1 without installing the transmission 3.
[0037]
The aforementioned two hydraulic pumps 10 and 11 are incorporated into a hydraulic circuit 20. The output end of the hydraulic pump 10 is connected to the hydraulic pump 11 through an oil passage 21. The input end of the
hydraulic pump 10 is connected to the hydraulic pump 11 through an oil passage 22.
[0038]
A small-size, variable-displacement hydraulic pump (third hydraulic pump) 12 is connected between the two oil passages 21 and 22 through oil passages 23 and 24. The oil passage 23 connects the hydraulic pump 12 to the oil passage 21, whereas the oil passage 24 connects the
hydraulic pump 12 to the oil passage 22. As described above, the hydraulic pump 12 is connected in parallel to the hydraulic pump 10 and hydraulic pump 11.
[0039]
These hydraulic pumps 10, 11 and 12 each operate as a hydraulic pump when rotationally driven by a pump shaft, and operate as a hydraulic motor when rotationally driven by hydraulic pressure. For the sake of naming simplicity, however, these pumps are simply referred to as the
hydraulic' pumps.
[0040]
An electric motor 13 is coupled to the variable- displacement hydraulic pump 12. The electric motor 13 not only functions as an electric motor to rotationally drive the hydraulic pump 12, but also functions as a power generator when it is rotationally driven by the hydraulic pump 12. For the sake of naming simplicity, however, it is simply referred to as the electric motor.
[0041]
The electric motor 13 is electrically connected to a central power distribution unit 14 of the vessel. As described later, electrical power can be obtained from the central power distribution unit 14 when the electric motor 13 operates as an electric motor, and the excess power of the turbocharger 5 can be used as the electrical power for the vessel when the electric motor 13 operates as a power generator. If the turbocharger excess power recovery device according to the present invention is used with a vehicle's internal combustion engine, the excess power of the turbocharger 5 can be used as the electrical power for the vehicle (mounting object) .
[0042]
A displacement adjuster for the hydraulic pump 12 may use various adjustment mechanisms such as an inclined plate type or an inclined axis type. A controller 15 is
installed in the device to regulate the fuel injection amount of the engine 1. Being electrically connected to the adjustment mechanism for the hydraulic pump 12, the controller 15 controls the adjustment mechanism to vary the displacement of the hydraulic pump 12.
[0043]
As shown in Fig. 2, a hydraulically-operated
changeover valve 25, a proportional solenoid safety valve 26 controlled by the controller 15, a safety valve 27, an open/close solenoid valve 28 controlled by the controller 15, and two opposing series-connected check valves 29 and 30 are sequentially connected in the order named between the two oil passages 21 and 22 and in parallel to the hydraulic pumps 11 and 12.
[0044]
A cooling hydraulic pump 35 is coupled to the
hydraulic pump 12 and rotationally driven by the hydraulic pump 12 or by the electric motor 13 coupled to the
hydraulic pump 12. The cooling hydraulic pump 35 is connected between the two check valves 29 and 30 through a filter 36.
[0045]
A cooling pump safety valve 32 and a heat exchanger 33 are connected between the two check valves 29, 30 and a tank 34 through an oil passage 37. The outlet of the hydraulically-operated changeover valve 25 is connected to the tank 34 through a safety valve 31, the oil passage 37, and the heat exchanger 33.
[0046]
An operation of the turbocharger excess power
recovery device according to the present invention will now be described. During a normal rotation of the engine 1, the controller 15 shown in Fig. 1 keeps the open/close solenoid valve 28 closed as shown in Fig. 2. In the hydraulic circuit 20, therefore, a unidirectional hydraulic circulation path is formed by the two hydraulic pumps 11 and 12 and the two oil passages 21 and 22.
[0047]
Meanwhile, while the load on the engine 1 is between low, for instance, at engine startup, and medium, that is, within a range of 40 to 50%, the amount of exhaust gas from the engine 1 is insufficient so that adequate turbocharging cannot be provided for the load on the engine 1 by the turbocharger 5 alone. Therefore, while the load on the engine 1 is between low and medium, the turbocharger excess power recovery device according to the present invention uses the hydraulic pressure generated by the hydraulic pump 11 coupled to the crankshaft 2 of the engine 1 to
rotationally drive the hydraulic pump 10 coupled to the turbocharger 5, thereby increasing the torque for the turbocharger 5. This ensures that the torque for the
turbocharger 5 is higher than that generated by the exhaust gas alone. As a result, the turbocharger 5 increases its speed and provides increased turbocharging for the engine 1.
[0048]
Fig. 3 shows the relationship between the rotation speed of the engine 1 and the rotation speed of the
turbocharger 5. The solid line in this graph represents a virtual operation curve that is exhibited by the hydraulic pump 10 and hydraulic pump 11 when the hydraulic pump 12 is not installed. The virtual operation curve is almost
linear because the hydraulic pump 10 and hydraulic pump 11 are both of the fixed-displacement type. The broken line, on the other hand, represents the actual rotation speed of the turbocharger 5 that prevails at various rotation speeds of the engine 1 when the hydraulic pump 12 is installed.
[0049]
Point A in Fig. 3 indicates a state where no flow rate adjustment is made by the hydraulic pump 12 in its actual operation state. At point A, the two fixed- displacement hydraulic pumps 10 and 11 have the same flow rate in their actual operation states. As shown in Fig. 3, the hydraulic pump 12 is electrically driven by the
electric motor 13 between a low-load operation region which includes a startup, and point A, and the hydraulic pump 12 hydraulically drives the electric motor 13 between point A and a rated-load operation region. For the engine 1, point A is set close to a normal-load operation region within which the engine load ranges from 75% to 85%. Obviously, point A need not always be set close to the normal-load operation region. [0050]
In the turbocharger excess power recovery device according to the present invention, the controller 15, which regulates the fuel injection amount of the engine 1 shown in Fig. 1, varies the displacement of the variable- displacement hydraulic pump 12 to let the electric motor 13 rotationally drive the hydraulic pump 12. This causes the two hydraulic pumps 11 and 12 to increase the torque for the turbocharger 5 as needed during a low-load operation including a startup. In other words, the hydraulic pump 10 operates as a hydraulic motor during a low-load operation as shown in Fig. 4. The central power distribution unit 14 of the vessel shown in Fig. 1 supplies electrical power to the electric motor 13.
[0051]
In the hydraulic circuit 20 shown in Fig. 2, the cooling hydraulic pump 35 is rotationally driven by the electric motor 13 to suction hydraulic oil from the tank 34 and supply cooled hydraulic oil to the oil passages 21 and 22 through the two check valves 29 and 30. If the
hydraulic oil supplied from the two check valves 29 and 39 is under excessive pressure, the lubricating oil returns to the tank 34 through the cooling pump safety valve 32 and heat exchanger 33. When either of the two oil passages 21 or 22 is placed under increased pressure, the proportional solenoid safety valve 26 and the safety valve 27 both open to prevent the entire circuit from being overloaded.
Further, the hydraulically-operated changeover valve 25 and the safety valve 31 allow the hydraulic fluid to be cooled by the oil passage 37 and heat exchanger 33 and then returned to the tank 34.
[0052]
When the load on the engine 1 exceeds a medium level, the amount of exhaust gas from the engine 1 begins to become excess for the turbocharger 5. In this instance, the controller 15 shown in Fig. 1 varies the displacement of the variable-displacement hydraulic pump 12, thereby causing the hydraulic pump 11 coupled to the crankshaft 2 to be rotationally driven by hydraulic pressure that is delivered from the hydraulic pump 10 due to the torque of the turbocharger 5.
[0053]
More specifically, the hydraulic pump 10 changes its operation mode to operate as a hydraulic pump when the load is 40 to 50% or higher, as shown in Fig. 4. Meanwhile, the hydraulic pump 12 is rotationally driven by the electric motor 13 until the load is near a normal level, as shown in Fig. 3. The hydraulic pressure delivered from the
hydraulic pump 12 then increases the rotation speed of the hydraulic pump 11 coupled to the crankshaft 2. It should be noted that the hydraulic pump 10 does not always have to switch from a motor mode to a pump mode when the load is between 40% and 50% as is the case with the engine 1.
[0054]
As shown in Fig. 3, while the load on the engine 1 is between substantially normal (point A in Fig. 3) and rated, which is high, the amount of exhaust gas from the engine 1 is more excess for the turbocharger 5. In this instance, the controller 15 shown in Fig. 1 varies the displacement of the variable-displacement hydraulic pump 12 in such a manner that the two hydraulic pumps 11 and 12 are
rotationally driven by the hydraulic pressure delivered from the hydraulic pump 10 due to the torque of the
turbocharger 5.
[0055]
More specifically, the hydraulic pump 11 provides auxiliary drive for the engine 1 through the crankshaft 2, while the hydraulic pump 12 operates as a hydraulic motor and rotationally drives the electric motor 13 as a power generator. Electrical power generated by the electric motor 13 is supplied to the vessel's central power
distribution unit 14 shown in Fig. 1. This ensures that the excess power of the turbocharger 5 can be recovered as motive power for the engine 1 and electrical power for the vessel .
[0056]
An operation performed by the turbocharger excess power recovery device according to the present invention when the vessel performs a crash astern operation, that is, the engine 1 rotates in a reverse direction, will now be described .
[0057]
As shown in Fig. 5, the controller 15 shown in Fig. 1 opens the open/close solenoid valve 28 when the engine 1 rotates in the reverse direction. In the hydraulic circuit 20, therefore, a hydraulic circuit for circulation between the hydraulic pump 10 and the open/close solenoid valve 28 and a hydraulic circuit for circulation between the
hydraulic pump 11 and the open/close solenoid valve 28 are formed. In this instance, in the hydraulic circuit for circulation between the hydraulic pump 10 and the
open/close solenoid valve 28, the hydraulic pump 11
operates under no-load conditions while the hydraulic pump 10 is isolated from the operation of the hydraulic pump 11.
[0058]
If, in this instance, the amount of exhaust gas from the engine 1 is in excess for the exhaust gas energy required for the turbocharger 5, the controller 15 varies the displacement of the variable-displacement hydraulic pump 12 in such a manner that the two hydraulic pumps 11 and 12 are rotationally driven by the hydraulic pressure delivered from the hydraulic pump 10 due to the torque of the turbocharger 5, as is the case with the aforementioned normal operation. The hydraulic pump 11 provides auxiliary drive for the engine 1 through the crankshaft 2, while the hydraulic pump 12 rotationally drives the electric motor 13 and supplies motor-generated electrical power to the vessel's central power distribution unit 14 shown in Fig. [0059]
In Fig. 6, the solid line shows the relationship between the load on the engine 1 in which the turbocharger excess power recovery device according to the present invention is incorporated and the scavenging air-pressure, whereas the broken line is a virtual curve showing the relationship between the load on the engine 1 in which the turbocharger excess power recovery device according to the present invention is not incorporated and the scavenging air-pressure .
[0060]
As is obvious from Fig. 6, the engine 1 in which the turbocharger excess power recovery device according to the present invention is incorporated differs from the engine 1 in which the turbocharger excess power recovery device according to the present invention is not incorporated in that the scavenging air-pressure is reduced in the whole engine load region.
[0061]
Meanwhile, the engine in which the turbocharger excess power recovery device is not incorporated discards excess exhaust gas which is not consumed by the
turbocharger, by discharging it to the atmosphere through a bypass valve or the like. On the other hand, the engine 1 in which the turbocharger excess power recovery device according to the present invention is incorporated allows the hydraulic pump 10 to generate hydraulic pressure in accordance with the decrease in the scavenging air-pressure. It means that excess exhaust gas energy is effectively used.
[0062]
In the turbocharger excess power recovery device according to the present invention, the hydraulic pump 10 coupled to the rotating shaft 8 of the turbocharger 5 and the hydraulic pump 11 coupled to the crankshaft 2 of the engine 1 are both of the fixed-displacement type. This makes it possible to reduce the sizes of the hydraulic pumps 10 and 11, make it easy to dispose the other
accessories around the engine 1, and achieve significant weight reduction. In addition, inexpensive fixed- displacement pumps can be introduced to reduce the
manufacturing cost of the device.
[0063]
The mutual hydraulic flow rate adjustments between the hydraulic pump 10 and the hydraulic pump 11 are made by the hydraulic pump 12 which is a variable-displacement hydraulic pump employed in addition to the fixed- displacement hydraulic pumps 10 and 11. The hydraulic pump 12 merely makes the mutual hydraulic flow rate adjustments between the hydraulic pumps 10 and 11. Therefore, a small- size, variable-displacement hydraulic pump is used as the hydraulic pump 12. It is extremely advantageous in terms, for instance, of cost as compared to conventional, large- size and variable-displacement hydraulic pumps.
[0064]
The two fixed-displacement hydraulic pumps 10 and 11 are connected with hydraulic piping alone. Therefore, the variable-displacement hydraulic pump 12 can be installed with an extremely high degree of freedom. This makes it easy to arrange, for instance, accessories around the engine 1.
[0065]
The included electric motor 13 rotates together with the hydraulic pump 12 as it is coupled to the rotating shaft of the hydraulic pump 12. Therefore, when it is necessary to increase the hydraulic flow rate in an oil passage with the hydraulic pump 12, the hydraulic flow rate can be increased by allowing the electric motor 13 to rotationally drive the hydraulic pump 12. When, on the other hand, it is necessary to decrease the hydraulic flow rate, the electric motor 13 can be operated as a power generator to recover the excess power of the turbocharger 5 as electrical power. [0066]
The included controller 15 is connected to the displacement adjuster of the hydraulic pump 12 to vary the displacement of the hydraulic pump 12. The controller 15 varies the displacement of the hydraulic pump 12 in
accordance with the load on the engine 1. Therefore, the mutual hydraulic flow rate adjustments between the two fixed-displacement hydraulic pumps 10 and 11 can be
optimally made in accordance with the ever-changing load on the engine 1.
[0067]
Further, while the load on the engine 1 is between low, for instance, at engine startup, and medium, the controller 15 varies the displacement of the hydraulic pump 12 in such a manner that the hydraulic pump 11 rotationally driven by the crankshaft 2 of the engine 1 and the
variable-displacement hydraulic pump 12 rotationally driven by the electric motor 13 cooperate to rotationally drive the hydraulic pump 10 coupled to the turbocharger 5.
[0068]
Consequently, while the exhaust gas energy is
insufficient, that is, while the load on the engine 1 is between low, for instance, at engine startup, and medium, the two hydraulic pumps 11 and 12 increase the torque of the hydraulic pump 10 coupled to the turbocharger 5. This makes it possible to provide optimum turbocharging for the engine 1.
[0069]
While the load on the engine 1 is between medium and substantially normal, the controller 15 varies the
displacement of the hydraulic pump 12 in such a manner that the two hydraulic pumps 10 and 12 cooperate to rotationally drive the hydraulic pump 11 coupled to the crankshaft 2. Therefore, when the load on the engine 1 is medium or higher so that the exhaust gas energy begins to become excess, the torque of the hydraulic pump 11 can be increased to apply additional force to the crankshaft 2 of the engine 1. This results in improved fuel economy.
[0070]
While the load on the engine 1 is between
substantially normal and rated, the controller 15 varies the displacement of the variable-displacement hydraulic pump 12 in such a manner that the hydraulic pump 11 coupled to the crankshaft 2 of the engine 1 and the variable- displacement hydraulic pump 12 are rotationally driven by the hydraulic pump 10 coupled to the turbocharger 5.
[0071]
Consequently, when the load on the engine 1 is between substantially normal and rated, that is, when the exhaust gas energy becomes more excess, the hydraulic pump 12 can rotationally drive the electric motor 13 to let the electric motor 13 generate electrical power. This makes it possible to optimally recover the excess power of the turbocharger 5.
[0072]
Furthermore, the controller 15 controls the fuel injection of the engine 1. Therefore, the displacement of the variable-displacement hydraulic pump 12 can be
optimally controlled in accordance with the amount of fuel injection of the engine 1. In addition, system
simplification can be achieved by allowing the single controller 15 to control the fuel injection of the engine 1 and the operation of the hydraulic pump 12.
[0073]
Moreover, the cooling hydraulic pump 35 which
supplies hydraulic oil from the tank 34 to the hydraulic circuit 20 is mounted on the rotating shaft of the
variable-displacement hydraulic pump 12 and rotationally driven by the hydraulic pump 12. Therefore, it is not necessary to additionally install a power source for the cooling hydraulic pump 35. In addition, the excess power of the turbocharger 5 can be recovered at a higher level. [0074]
The turbocharger excess power recovery device
according to the present invention has been described by way of example only. The invention is not limited to the above-described embodiment, but extends to various
modifications that nevertheless fall within the scope of the appended claims.
Industrial Applicability
[0075]
The turbocharger excess power recovery device
according to the present invention can not only be applied to the above-described two-cycle propulsion diesel engine mounted in a vessel, but can be widely applied to all kinds and types of internal combustion engines having a
turbocharger .

Claims

Claims
1. A turbocharger excess power recovery device for an internal combustion engine, the device comprising:
a turbocharger (5) which is rotationally driven by exhaust gas from the internal combustion engine (1) to supply charge air to the internal combustion engine;
a first hydraulic pump (10) which is a fixed- displacement hydraulic pump that is coupled to a rotating shaft of the turbocharger and rotates together with the turbocharger;
a second hydraulic pump (11) which is a fixed- displacement hydraulic pump that is coupled to a crankshaft (2) of the internal combustion engine and rotates together with the crankshaft;
a hydraulic circuit (20) which connects the first hydraulic pump (10) to the second hydraulic pump (11);
a third hydraulic pump (12) which is a variable- displacement hydraulic pump that is provided for the hydraulic circuit to make mutual hydraulic flow rate adjustments between the first hydraulic pump (10) and the second hydraulic pump (11); and
an electric motor (13) which is coupled to a rotating shaft of the third hydraulic pump (12) and rotates together with the third hydraulic pump (12) .
2. The turbocharger excess power recovery device according to claim 1, further comprising:
a controller (15) which is connected to a
displacement adjuster of the third hydraulic pump (12) to vary the displacement of the third hydraulic pump (12), wherein the controller varies the displacement of the third hydraulic pump (12) in accordance with loads on the internal combustion engine.
3. The turbocharger excess power recovery device according to claim 2,
wherein, when the load on the internal combustion engine (1) is low, the controller (15) varies the
displacement of the third hydraulic pump (12) in such a manner that the second hydraulic pump (11) and the third hydraulic pump (12) cooperate to rotationally drive the first hydraulic pump (10).
4. The turbocharger excess power recovery device according to claim 2 or 3,
wherein, when the load on the internal combustion engine (1) is between medium and substantially normal, the controller (15) varies the displacement of the third hydraulic pump (12) in such a manner that the first hydraulic pump (10) and the third hydraulic pump (12) cooperate to rotationally drive the second hydraulic pump (11) .
5. The turbocharger excess power recovery device according to any one of claims 2 to 4,
wherein, when the load on the internal combustion engine (1) is between substantially normal and rated, the controller (15) varies the displacement of the third hydraulic pump (12) in such a manner that the first hydraulic pump (10) rotationally drives the second
hydraulic pump (11) and the third hydraulic pump (12) .
6. The turbocharger excess power recovery device according to any one of claims 2 to 5,
wherein the controller (15) controls the fuel
injection to the internal combustion engine (1).
7. The turbocharger excess power recovery device according to any one of claims 1 to 6, further comprising: a fourth hydraulic pump (35) which supplies hydraulic oil from a tank (34) to the hydraulic circuit (20),
wherein the fourth hydraulic pump is mounted on the rotating shaft of the third hydraulic pump (12) and rotationally driven by the third hydraulic pump (12) .
8. The turbocharger excess power recovery device according to any one of claims 2 to 7,
wherein the electric motor (13) is connected to a central power distribution unit (14) for a mounting object in which the internal combustion engine (1) is mounted, and receives or supplies electrical power.
PCT/JP2012/053197 2012-02-06 2012-02-06 Turbocharger excess power recovery device for internal combustion engine WO2013118308A1 (en)

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JP2012511471A JP5886188B2 (en) 2012-02-06 2012-02-06 Supercharger surplus power recovery device for internal combustion engine

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JP2015090103A (en) * 2013-11-06 2015-05-11 三井造船株式会社 Supercharger surplus power recovery device of internal combustion engine
US20160032817A1 (en) * 2014-08-04 2016-02-04 Jeffrey J. Buschur Power conversion device
US9709065B2 (en) 2014-11-06 2017-07-18 Ford Global Technologies, Llc System and method for a turbocharger driven coolant pump

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JP2015090103A (en) * 2013-11-06 2015-05-11 三井造船株式会社 Supercharger surplus power recovery device of internal combustion engine
WO2015068706A1 (en) * 2013-11-06 2015-05-14 三井造船株式会社 Supercharger surplus power recovery device for internal combustion engine
CN105705743A (en) * 2013-11-06 2016-06-22 三井造船株式会社 Supercharger surplus power recovery device for internal combustion engine
US20160032817A1 (en) * 2014-08-04 2016-02-04 Jeffrey J. Buschur Power conversion device
US9915192B2 (en) * 2014-08-04 2018-03-13 Jeffrey J. Buschur Power conversion device
US9709065B2 (en) 2014-11-06 2017-07-18 Ford Global Technologies, Llc System and method for a turbocharger driven coolant pump

Also Published As

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JP5886188B2 (en) 2016-03-16

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