JPH11280500A - Gas engine having turbocharger provided with motor generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gas engine having a turbocharger provided with a motor generator which adopts natural gas as fuel, properly controls an actual compression ratio while controlling opening/closing timings of an intake valve. SOLUTION: This type of gas engine has an intake valve lift control device 30 which varies an opening/closing timing of an intake valve 11 which opens and closes an intake port 9. An actual compression ratio is varied by varying an opening period of the intake port 9 of the intake valve 11 by the intake valve lift control device 30. The intake valve lift control device 30 is so operated that the closing timing of the intake port 9 of the intake valve 11 is advanced to close the port 9 near a bottom dead center in a compression process, when an intake temperature and/or combustion chamber wall temperature is lower than a specified value, and the closing timing of the port 9 is retarded to counter-flow a part of intake to the intake port 9 when the combustion chamber wall temperature is the specified value or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas engine having a turbocharger with an electric / generator using natural gas supplied to a sub-chamber as a fuel.

[0002]

2. Description of the Related Art Conventionally, a gas engine using natural gas as a main fuel has been developed as a cogeneration system. In a cogeneration system, power is extracted as electric energy by a generator, and heat of exhaust gas energy is heated by a heat exchanger to heat water to make hot water, and the hot water is used for hot water supply. Conventionally, as an engine using natural gas as a fuel, for example, Japanese Unexamined Patent Publication No.
No. 65, and Japanese Patent Application Laid-Open No. 6-101495.

A cogeneration type gas engine disclosed in Japanese Patent Application Laid-Open No. Hei 6-108865 reduces the temperature of exhaust gas through a turbocharger, an energy recovery device and a steam generator, and reduces the temperature of low-temperature exhaust gas to E.
It is used for GR to reduce NO _x , and a turbocharger is driven by exhaust gas from a heat shielding gas engine, and an exhaust gas from the turbocharger drives an energy recovery device including a generator. The cogeneration type gas engine sends exhaust gas from an energy recovery device to a steam generator of a heat exchanger, converts water into steam by the steam generator, and drives a steam turbine with the steam to recover electric energy. I do.

[0004]

By the way, natural gas is used as fuel, the gaseous fuel is supplied to the sub-chamber, the control valve is opened in the compression stroke of the engine, and compressed air flows from the combustion chamber into the sub-chamber. In the system in which gas fuel and air are mixed and burned, while natural gas is present in the sub-chamber, natural gas receives heat from the sub-chamber wall surface and activation is progressing. Depending on the conditions of the air entering the chamber, the compressed natural gas (CNG) ignites easily and ignites before the air has fully penetrated the subchamber. That is, since compressed natural gas is a gaseous fuel, not a liquid fuel like light oil, there is no need for a change in which the liquid is vaporized and decomposed, there is no required ignition delay time, and the compressed natural gas comes into contact with high-temperature compressed air. I ignite immediately,
The time for natural gas and air to mix sufficiently is too short, so ignition and combustion occur immediately near the communication port, knocking occurs, generating a pressure wave, transferring heat to the combustion chamber and destroying the combustion chamber. There is a problem of reaching.

However, ignition combustion of natural gas does not readily occur when the temperature of a control valve provided in a combustion chamber or a communication port connecting a combustion chamber and a sub-chamber is low, so that a gas engine is usually used in a compression ratio. Is set higher. Gas engines have higher compression ratios, which increase thermal efficiency.
We want to increase the compression ratio, but if the compression ratio is high, abnormal combustion, that is, knocking, is likely to occur. Therefore, it is important to set the compression ratio to improve the thermal efficiency and prevent abnormal combustion. It is.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and pays attention to the fact that knocking in a combustion chamber is caused by a high compression ratio.
In the first half of the compression stroke, the intake air flows back to the intake port to reduce the maximum pressure at the compression end, so that ignition near the entrance of the communication port is unlikely to occur at the same time that the control valve is opened, and sufficient intake air is supplied to the sub-chamber. In addition to preventing knocking from occurring, the boost pressure is increased to eliminate the shortage of intake air volume. When the intake air temperature is low or the combustion chamber wall temperature is low, the intake valve is closed. When the temperature of the combustion chamber wall is high, the closing timing of the intake valve is delayed to ignite the compressed natural gas 5 ° before compression top dead center (crank angle).
Ignited combustion at all times, and does not reduce the amount of air supplied to the combustion chamber even when the intake valve closing timing is delayed. An object of the present invention is to provide a gas engine provided with a turbocharger with an electric / generator, which is configured to operate a compressor of a turbocharger by operating a motor of the electric / generator to increase intake air pressure.

According to the present invention, there is provided a combustion chamber member formed with a main chamber and a sub-chamber communicating with the main chamber through a communication port and arranged in a cylinder head, a combustion chamber member communicating with the main chamber, and the cylinder head and the combustion chamber. An intake port and an exhaust port formed in the member, an intake valve arranged at the intake port to open and close the intake port, an exhaust valve arranged at the exhaust port to open and close the exhaust port, and opening and closing the communication port A turbocharger provided with a control valve disposed at the communication port, fuel supply means for supplying compressed natural gas to the sub-chamber, and a motor / generator provided in an exhaust pipe communicating with the exhaust port. And an intake valve lift control device for changing the opening / closing timing of the intake port of the intake valve, wherein the intake valve lift control device closes the intake port of the intake valve. A gas engine with electric generating turbocharger consisting of changing the actual compression ratio by changing the timing.

When the intake air temperature and / or the combustion chamber wall temperature is lower than a predetermined temperature, the intake valve lift control device sets the intake port of the intake valve to a closed period so as to shorten the compression stroke. Control is performed so as to close near the point, and when the temperature of the combustion chamber wall is higher than a predetermined temperature, the closing period of the intake port of the intake valve is delayed so that a part of intake air flows back to the intake port. It is controlled so as to make it.

When the intake valve lift control device delays the closing period of the intake port of the intake valve, the turbocharger controls the pressure of the intake air to increase.

In the gas engine provided with the turbocharger with a motor / generator, when the partial load of the combustion is unstable, the motor / generator provided in the turbocharger is operated by the motor to increase the pressure of the intake air. It is controlled so as to make it.

The motor / generator is a motor / generator comprising a permanent magnet rotor fixed to a shaft of the turbocharger and a stator arranged with respect to the rotor.

A gas engine provided with a turbocharger with a motor / generator is driven by a battery or a generator attached to an engine output shaft when the motor / generator is operated by a motor.

The combustion chamber member includes the main chamber, the sub-chamber, the communication port for communicating the main chamber with the sub-chamber, the intake port having a valve seat on which the intake valve is seated, and the exhaust port. Said exhaust port with a valve seat on which the valve sits,
And a fuel supply port opened to the sub-chamber for supplying the compressed natural gas from the fuel supply means to the sub-chamber.

As described above, the gas engine provided with the turbocharger with a motor / generator is configured to control the opening / closing timing of the intake valve in accordance with the intake air temperature and the combustion chamber wall temperature. Regardless of the temperature conditions, sufficient intake air can be supplied to the sub-chamber, and gas fuel can be ignited and burned at about 5 ° before compression top dead center. In order to reduce the differential pressure at the compression end, in the latter half of the compression stroke, the control valve opens the control valve slightly to start the intake air into the sub-chamber to start mixing the intake air and fuel. The control valve is greatly opened near the top dead center to ignite and burn in the sub chamber. In this gas engine, for example, even if the combustion chamber wall is raised and the gas fuel in the sub-chamber is activated, the maximum pressure at the compression end is reduced and the compression ratio is reduced. Even if it flows into the chamber, ignition combustion does not occur until a predetermined amount of air is supplied, knocking can be prevented, and an appropriate amount of air flows into the sub-chamber to suppress the generation of HC and soot.
Since the compression ratio is appropriately controlled, a predetermined thermal efficiency can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas engine having a turbocharger with a motor / generator according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a gas engine provided with a turbocharger with a motor / generator according to the present invention, and FIG. 2 shows a turbocharger having a motor / generator provided in an exhaust pipe of the gas engine of FIG. FIG. 3 is a diagram showing valve timings of an intake valve, an exhaust valve, a control valve, and a fuel valve in the gas engine of FIG. 1, and FIG. 4 is a PV line showing an example of a Miller cycle of the gas engine of FIG. FIG.

A gas engine provided with a turbocharger with a motor / generator according to the present invention uses natural gas mainly composed of CH ₄ as fuel, and is, for example, a single cylinder type or a multi cylinder type applicable to a cogeneration system or a vehicle. Sub-chamber type gas engine. In this gas engine, a generator 46 for converting engine rotational force into electric power is provided on an engine crankshaft, that is, an engine output shaft 47. This gas engine includes, for example, a cylinder liner 26 forming a cylinder 27 disposed in a hole 39 formed in a cylinder block 24, a cylinder head 4 attached to the cylinder block 24 via a gasket 32, and a cylinder head 4. The combustion chamber member 3 is disposed in the cavity 14 formed with the gasket 29 therebetween. The main chamber 1 and the sub-chamber 2 of the combustion chamber formed in the combustion chamber member 3 and the piston 6 reciprocating in the cylinder 27 are provided. It is configured. The piston 6 is attached by a coupling ring 38 via a gasket 48 so as to form a heat shielding air layer 37 on the piston head 22 in which a concave portion 45 forming a part of the main chamber 1 is formed. The piston skirt 23 is formed.

This gas engine is mainly formed in a main chamber 1 formed in a combustion chamber member 3, a sub chamber 2 communicating with the main chamber 1 through a communication port 25, and a combustion chamber member 3 communicating with the main chamber 1. An intake port 7 formed in a cylinder head 4 communicating with the intake port 9, an exhaust port 10 formed in a combustion chamber member 3 communicating with the main chamber 1, and a cylinder head 4 communicating with the exhaust port 10. In order to open and close the exhaust port 8 and the intake port 9, an intake valve 11 arranged in the intake port 9, to open and close the exhaust port 10, an exhaust valve 12 arranged in the exhaust port 10, and to open and close the communication port 25. The control valve 5 disposed on the valve seat 36 of the port 25, fuel supply means for supplying compressed natural gas to the sub-chamber 2, and the motor / generator 18 provided on the exhaust pipe 31 communicating with the exhaust port 8. Turbocharger 15 was example, and is composed of the intake valve lift control device 30 for changing the opening and closing timing of the intake ports 9 of the intake valve 11.

The fuel supply means includes a fuel supply passage 33 formed in the cylinder head 4 connected to the fuel supply source, a fuel supply opening 43 in which the fuel supply passage 33 opens to the sub chamber 2, and a fuel supply opening 43. It comprises a fuel valve 13. When the fuel valve 13 opens the fuel supply port 43, compressed natural gas is supplied from the fuel supply source to the sub-chamber 2 through the fuel supply path 33. The combustion chamber member 3 includes a main chamber 1, a sub chamber 2, a communication port 25 for communicating the main chamber 1 and the sub chamber 2, an intake valve 1
The intake port 9 having a valve seat 34 on which the exhaust valve 1 is seated, and the exhaust port 1 having a valve seat 35 on which the exhaust valve 12 is seated.
0 and a fuel supply port 43 opened to the sub-chamber 2.

When this gas engine is formed as a single cylinder type, as shown in FIG.
In the case where the exhaust pipe 31 and the intake pipe 40 are directly attached to each other and are formed in a multi-cylinder type, though not shown, the exhaust pipe 31 and the intake pipe 40 are connected to the cylinder head 4 via a manifold. Each is attached. The turbine 16 of the turbocharger 15 is arranged in the exhaust pipe 31. The intake pipe 40 is connected to the compressor 17 of the turbocharger 15, and the intake air from the compressor 17 is sent into the intake pipe 40.

As shown in FIG. 2, the turbocharger 15 is a turbine 16 driven by exhaust gas, connected to the turbine 16 by a shaft 21 and provided with a turbine 1.
6 comprises a compressor 17 driven by the motor 6 and an electric / generator 18 provided for the shaft 21. The compressor 17 is driven by the turbine 16 to pressurize air into compressed air, and supply the compressed air from the intake ports 7 and 9 to the main chamber 1 of the cylinder through the intake pipe 40. The generator 18 can take out the rotational force of the turbine 16 as electric power, store it in a power supply device such as a battery, and recover it. The motor / generator 18 is a motor / generator including a permanent magnet rotor 19 fixed to a shaft 21 and a stator 20 composed of a coil arranged with respect to the rotor 19.

The gas engine has a temperature sensor 5
1 according to a command from the controller 50 in accordance with the detected value of the intake air temperature or the combustion chamber wall temperature.
0, and the actual compression ratio is changed by changing the valve closing timing of the intake port 9 of the intake valve 11 by the intake valve lift control device 30. The intake valve lift control device 30 is provided on the valve stem 49 of the intake valve 11 and is driven by an electromagnetic force acting on the valve stem 49 or a hydraulic pressure controlled by the electromagnetic valve acts on the valve stem 49. It can be constituted by a hydraulic drive device or the like that is driven in a driven manner. The adjustment of the opening / closing timing of the intake valve 11 controls the amount of intake air to the main chamber 1, and the compression ratio is determined according to the amount of intake air supplied to the main chamber 1. Therefore, this gas engine is controlled by the controller 50 so that the compression ratio does not become too high and the compression ratio does not become too low.

In the gas engine, when the intake valve lift control device 30 delays the closing period of the intake port 9 of the intake valve 11, the turbocharger 15 controls the pressure of the intake air to increase. In this gas engine, when the partial load of the combustion is unstable, the motor / generator 18 provided in the turbocharger 15 can be controlled so as to operate the electric motor to increase the pressure of the intake air. When the motor / generator 18 is driven by a motor, it can be driven by a battery or a generator 46 attached to an engine output shaft 47.

In this gas engine, the turbocharger 1 is opened by opening the intake valve 11 with the control valve 5 closed.
The air from the compressor 17 is supplied to the main chamber 1 from the intake ports 7 and 9 through the intake pipe 40. The air in the main chamber 1 is compressed in the compression stroke with the control valve 5 closed. On the other hand, the natural gas fuel is supplied from the gas fuel supply source to the sub-chamber 2 from the fuel supply port 43 through the natural gas supply passage 33. The combustion chamber member 3 that forms the main chamber 1 and the sub chamber 2 is S
The main chamber 1 and the sub-chamber 2 are made of ceramics such as i ₃ N ₄ and are disposed in the cavity 14 of the cylinder head 4 with a gasket 29 interposed therebetween so as to form a heat-insulating air layer 28.
Is configured as a heat shield structure.

Next, referring to FIGS. 3 and 4, the operation of the gas engine provided with the turbocharger with the electric motor / generator will be described. This gas engine is operated by a Miller cycle as shown in FIG. 4, which includes an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. Further, in the Miller cycle shown in FIG. 4, the cylinder pressure differs between the full load and the partial load of the engine, and the pressure is high at the full load and low at the partial load. And operating conditions of partial load are not separately described.

In this gas engine, as shown in the diagram of FIG. 3, the exhaust valve 12 is connected to the exhaust port 1 near the bottom dead center of the expansion stroke.
0 is opened and the control valve 5 opens the communication port 25, so that the exhaust gas existing in the main chamber 1 and the sub-chamber 2 is exhausted through the exhaust ports 10, 8 and the exhaust pipe 31 in the exhaust stroke, and the exhaust gas is discharged. Turbocharger 15 provided in exhaust pipe 31
And discharged from the exhaust gas outlet 42. At this time, the fuel valve 13 closes the fuel supply port 43 and the gas fuel is not supplied to the sub chamber 2. When the turbine 16 of the turbocharger 15 is driven by the exhaust gas, the compressor 17 is driven through the shaft 21, and the air taken in from the air inlet 41 by the drive of the compressor 17 is pressurized by the compressor 17 and is then compressed by the intake pipe 40. The air is supplied from the intake ports 7 and 9 to the main chamber 1 through the intake port. In addition, the rotation of the shaft 21 rotates the rotor 19 of the permanent magnet fixed to the shaft 21, and the motor / generator 18 operates as a generator. The electric power generated by the motor / generator 18 is stored in the battery. Or consumed by auxiliary equipment.

In this gas engine, in particular, the intake valve 11
Is controlled by the intake valve lift control device 30, and when the intake air temperature and / or the combustion chamber wall temperature is lower than a predetermined temperature, as shown by a solid line in FIG. Control is performed so that the valve closing period of the intake port 9 is closed near the bottom dead center of the compression stroke by a normal lift. When the combustion chamber wall temperature is higher than a predetermined temperature, the closing period of the intake port 9 of the intake valve 11 is delayed (delayed) in the first half of the compression stroke as shown by the dotted line in FIG. It is controlled so that it is closed and a part of the intake air of the main chamber 1 flows back to the intake ports 9 and 7. In this gas engine, the intake air temperature and the combustion chamber wall temperature are detected by a temperature sensor 51. The detection signals of the intake air temperature and the combustion chamber wall temperature detected by the temperature sensor 51 are determined by the controller 50, and the opening / closing timing of the intake valve 11 by the intake valve lift control device 30 is controlled.

In this gas engine, near the top dead center H of the exhaust stroke, the intake valve 11 opens the intake port 9 and shifts to the top dead center I of the intake stroke, and the control valve 5 closes the communication port 25 to close the main port. The chamber 1 and the sub chamber 2 are shut off, and the intake air supercharged from the compressor 17 of the turbocharger 15 is supplied to the main chamber 1. At this time, the in-cylinder pressure during the exhaust stroke and the intake stroke hardly changes. After the control valve 5 closes the communication port 25, the fuel valve 13 opens the fuel supply port 43, and natural gas fuel is supplied to the sub chamber 2 through the fuel supply path 33. In this gas engine, when the opening and closing timing of the intake valve 11 is controlled by the intake valve lift control device 30 and the intake air temperature and / or the combustion chamber wall temperature is lower than a predetermined value, as shown by a solid line in FIG. Next, control is performed such that the closing period of the intake port 9 of the intake valve 11 is closed by the normal lift near the bottom dead center E of the compression stroke. In the case of natural gas, since the adiabatic compression and expansion are performed, the compression starts at a point E ′ where the pressure does not coincide with the bottom dead center E and the pressure slightly decreases. At that time, the compression stroke is the pressure in the main chamber 1 is increased in accordance with PV line passing through the point C, become pressure P ₃ in the compression stroke top dead center in a state where the compression ratio is up.

When the combustion chamber wall temperature is higher than a predetermined temperature, the closing period of the intake port 9 of the intake valve 11 is delayed so as to close in the first half A of the compression stroke, as shown by the dotted line in FIG. Then, control is performed so that a part of the intake air in the main chamber 1 flows back to the intake ports 9 and 7. At this time, in the compression stroke, the pressure in the cylinder reaches point A without increasing until the intake valve 11 closes the intake port 9 until the intake valve 11 closes the intake port 9. It becomes the pressure P ₁ in stroke top dead center, a state condition the pressure is reduced, thus the compression ratio is reduced. In this state, since the intake air amount is insufficient, the boost pressure is increased by operating the turbocharger 15 (top dead center I → IB of the intake stroke, bottom dead center E → E of the compression stroke).
B), to shift from point A to point B, the pressure in the main chamber 1 is increased in accordance with PV line passing through the point B shown by the dotted line, it becomes on the dead point pressure P ₂ in the TDC compression stroke, the proper compression ratio Become,
Knocking does not occur and a sufficient amount of intake air can be supplied. In some cases, when the temperature of the combustion chamber wall is higher than a predetermined temperature, the lift of the intake valve 11 is controlled to be small within the range shown by hatching in FIG. 3 or FIG. Is controlled in a range from the bottom dead center BDC of the compression stroke to the first half of the compression stroke (corresponding to the position of the point A) to backflow a part of the intake air of the main chamber 1 to the intake ports 9 and 7. In this case, the pressure in the main chamber 1 increases in accordance with the PV line passing through a point in the range of the points A to C in the compression stroke, and the pressures P _{1 to} P _{3 at} the top dead center TDC of the compression stroke. The pressure falls within the range, and the compression ratio is reduced.

In this gas engine, the intake air in the main chamber 1 does not flow back to the intake ports 9 and 7 when the intake valve 11 is closed in the state shown by the solid line in FIG. It is compressed in the main chamber 1. When the intake valve 11 is closed with a delay in the state shown by the dotted line in FIG. 3, a part of the intake air in the main chamber 1 flows back to the intake ports 9 and 7, so that the predetermined air in the main chamber 1 In order to secure the amount, the boost pressure is increased by the compressor 17 of the turbocharger 15, or the boost pressure cannot be increased when the combustion is an unstable partial load.
In response to a command from the controller 50, the motor / generator 18 is controlled to operate as a motor to increase the intake air pressure. That is, when following the PV line passing through the point A or the point C in the compression stroke, if the boost pressure is increased, the PV passing through the point B or the point D
The boost pressure in the main chamber 1 increases according to the line, and at the top dead center of the compression stroke, the pressure P ₁ → pressure P ₂ or pressure P ₃ → pressure P ₄
To a state where a predetermined intake air amount can be secured.

In the compression stroke after the intake valve 11 closes the intake port 9, the intake air in the main chamber 1 is compressed to become high-temperature compressed air. Therefore, near the top dead center of the compression stroke, the control valve 5
Opens the communication port 25, and the high-temperature compressed air is supplied from the main chamber 1 to the sub-chamber 2 through the communication port 25 in the main chamber 1. Main room 1
When the high-temperature compressed air is supplied to the sub-chamber 2 through the communication port 25, the high-temperature compressed air is quickly mixed with the gas fuel in the sub-chamber 2 to ignite and burn, and the pressure in the sub-chamber 2 reaches the maximum pressure J. Up from the sub chamber 2 to the main chamber 1 through the communication port 25,
Gas such as unburned air-fuel mixture is blown out and shifts to the expansion stroke.
The piston 6 is pushed down from the vicinity K at the top dead center of the expansion stroke toward the bottom dead center G of the expansion stroke to perform work on the piston 6. In this gas engine, the engine output shaft 47 is rotated by the lowering of the piston 6, and the engine output shaft 47 is
To generate electricity. Exhaust valve 1 near bottom dead center G in expansion stroke
2 is opened, the cylinder pressure slightly decreases, and the exhaust stroke bottom dead center F
Then, the exhaust stroke progresses and progresses to the top dead center of the exhaust stroke.

[0031]

The gas engine provided with the turbocharger with a motor / generator according to the present invention is constructed as described above, and changes the opening / closing timing of the intake valve in accordance with the intake air temperature and the combustion chamber wall temperature. When the actual compression ratio can be changed, and the valve closing timing of the intake valve is delayed, the turbocharger is driven to secure the amount of intake air supplied to the main chamber. Since the intake air pressure is increased by operating the motor / generator provided in the turbocharger by the electric motor, an appropriate intake air amount is always supplied to the main chamber, the actual compression ratio can always be set appropriately, and the thermal efficiency can be improved. Can be. In addition, the actual compression ratio is always set appropriately regardless of the temperature conditions of the intake air temperature and the combustion chamber wall temperature. Therefore, sufficient intake air is supplied from the main chamber to the sub chamber, and the compression ratio is too high to knock. And the appropriate ignition and combustion is performed in the sub-chamber, so that the generation of HC and soot can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a gas engine provided with a turbocharger with an electric / generator according to the present invention.

FIG. 2 is an explanatory view showing a turbocharger having a motor / generator provided in an exhaust pipe of the gas engine of FIG.

FIG. 3 shows an intake valve, an exhaust valve, and the like in the gas engine of FIG.
FIG. 3 is a diagram illustrating valve timings of a control valve and a fuel valve.

FIG. 4 is a schematic explanatory view of a PV line showing an example of a mirror cycle of the gas engine of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main chamber 2 Sub-chamber 3 Combustion chamber member 4 Cylinder head 5 Control valve 7, 9 Intake port 8, 10 Exhaust port 11 Intake valve 12 Exhaust valve 13 Fuel valve 15 Turbocharger 18 Electric / generator 19 Rotor 20 Stator 21 Shaft 25 Connection port 30 Intake valve lift control device 31 Exhaust pipe 33 Fuel supply path 34, 35, 36 Valve seat 40 Intake pipe 43 Fuel supply port 46 Generator 47 Engine output shaft

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI F02D 19/02 F02D 19/02 Z 23/00 23/00 K F02M 21/02 301 F02M 21/02 301L

Claims (7)

[Claims] 1. A combustion chamber member formed with a main chamber and a sub-chamber communicating with the main chamber through a communication port, and disposed in a cylinder head, communicating with the main chamber and being connected to the cylinder head and the combustion chamber member. Intake and exhaust ports formed in
An intake valve arranged at the intake port to open and close the intake port, an exhaust valve arranged at the exhaust port to open and close the exhaust port, and a control valve arranged at the communication port to open and close the communication port Fuel supply means for supplying compressed natural gas to the sub-chamber, a turbocharger having a motor / generator provided in an exhaust pipe communicating with the exhaust port, and opening / closing timing of the intake port of the intake valve A turbocharger with an electric / generator, comprising: changing an actual compression ratio by changing a closing timing of the intake port of the intake valve by the intake valve lift control device. With a gas engine. 2. The intake valve lift control device according to claim 1, wherein when the intake air temperature and / or the combustion chamber wall temperature is lower than a predetermined temperature, a closing period of the intake port of the intake valve is shortened to increase a compression stroke. When the wall temperature of the combustion chamber is higher than a predetermined temperature, the closing period of the intake port of the intake valve is delayed so that a part of the intake air is reduced to the intake port. The gas engine provided with the turbocharger with an electric / generator according to claim 1, wherein the gas engine is controlled to flow backward. 3. The intake valve lift control device controls the intake air pressure to be increased by the turbocharger when the closing period of the intake port of the intake valve is delayed. A gas engine equipped with the turbocharger with an electric / generator according to the above. 4. The system according to claim 3, wherein when the partial load of the combustion is unstable, the motor / generator provided in the turbocharger is operated by an electric motor so as to increase the pressure of the intake air. Gas engine equipped with a turbocharger with an electric / generator. 5. A motor / generator comprising a permanent magnet rotor fixed to a shaft of the turbocharger and a stator arranged with respect to the rotor. Item 5. A gas engine comprising the turbocharger with an electric / generator according to any one of Items 1 to 4. 6. The motor / generator according to claim 1, wherein the motor / generator is driven by a battery or a generator attached to an engine output shaft.
A gas engine provided with the turbocharger with an electric / generator according to item 9. 7. The combustion chamber member, wherein the main chamber, the sub-chamber, the communication port for communicating the main chamber with the sub-chamber, the intake port including a valve seat on which the intake valve is seated, The exhaust port including a valve seat on which the exhaust valve is seated,
7. An electric motor according to claim 1, further comprising a fuel supply port opened to said sub-chamber for supplying compressed natural gas from said fuel supply means to said sub-chamber. Gas engine with turbocharger with generator.