JP2003120351A - Internal combustion engine and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine and an operation control method therefor that solves various disadvantages resulting from uneven compositions of a fuel mixture. SOLUTION: The internal combustion engine, where a fuel mixture storing means 4 is supplied with each of a plurality of fuels F1 to F4 different in calorific value per unit quantity, comprises a fuel supplying means (a fuel valve) 6 interposed in a region of an intake system 2 between a mixer 3 and a throttle valve 5 and supplying the fuel to the intake system 2, a flow regulating means (a fuel valve travel regulating means 7 and a pump 8) for regulating the fuel flow rate supplied from the fuel supplying means 6 to the intake system 2, and a controlling means 9. The controlling means 9 executes control of regulating the fuel flow rate supplied from the fuel supplying means 6 to the intake system 2, in response to a detection result from a detecting means (an exhaust pressure sensor 11, a speed sensor 12, a power sensor, a cylinder pressure sensor and an acceleration sensor) for detecting disadvantages in an operation of the internal combustion engine 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an internal combustion engine that uses a mixed fuel of a plurality of fuels (for example, gaseous fuels) having different calorific values as fuel.

[0002]

2. Description of the Related Art There is an internal combustion engine that uses a plurality of fuels (mixed fuels) having different calorific values as fuels, and as the plurality of fuels, for example, four kinds of gaseous fuels (F1 to F4) are used conventionally. An example of the technique is shown in FIG.

In FIG. 13, the four types of gaseous fuel F
1 to F4 are mixed and stored in the mixed fuel storage tank T, are charged into the mixer 3 via the fuel supply line Lf, are mixed with the air supplied from the air supply line La by the mixer 3, and the intake pipe 20 Is sucked into the combustion chamber of the gas engine 1. In the figure, reference numeral 5 indicates a throttle valve, and E indicates an exhaust pipe.

On the other hand, in recent years, so-called "biogas" (for example, containing methane gas as a main component) is often used as one of the plurality of fuels in response to the demand for energy saving and the increasing awareness of environmental problems. . However, low calorific fuel gases such as biogas have a non-uniform composition, and therefore
The composition of the mixed fuel gas itself stored in the mixed fuel storage tank T is also non-uniform. Then, the mixer 3 alone cannot cope with the composition variation of the mixed fuel gas,
When the internal combustion engine 1 is operated, various inconveniences may occur, such as fluctuations in the air-fuel ratio, deterioration in operation stability, deterioration in follow-up performance during sudden load changes, and the like.

More specifically, due to the non-uniform composition of the fuel supplied to the internal combustion engine, misfire, insufficient output, knocking,
Various inconveniences such as deterioration of load responsiveness occur.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed to address the above-mentioned problems of the prior art, and uses an internal combustion engine that uses a mixed fuel in which a plurality of fuels having different calorific values are mixed as a fuel. It is an object of the present invention to provide an operation control method for the internal combustion engine and an operation control method for the internal combustion engine that can eliminate various inconveniences caused by the nonuniform composition of the mixed fuel.

[0007]

In the internal combustion engine of the present invention, a mixer (3) is provided in the intake system (2), and the mixer (3) has an air supply line (La) and a fuel supply line (Lf). )
Are connected to each other, the fuel supply line (Lf) communicates with the mixed fuel storage means (4), and the mixed fuel storage means (4) has a plurality of fuels (F1 to F1) having different calorific values per unit amount.
4) are respectively supplied, and are provided in a region of the intake system (2) between the mixer (3) and the throttle valve (5) and supply fuel to the intake system (2). Valve) (6) and the fuel supply means (6) to the intake system (2)
A flow rate adjusting means (fuel valve opening adjusting means 7, pump 8) for adjusting the flow rate of fuel supplied to the engine and a control means (9) are provided, and the control means (9) operates the internal combustion engine (1). From the fuel supply means (6) to the intake system (2) in response to the detection results from the detection means (exhaust pressure sensor 11, rotation sensor 12, electric power sensor 13, cylinder pressure sensor 14, acceleration sensor 15) for detecting the inconvenience. It is configured to perform control for adjusting the flow rate of the fuel supplied to the cylinder (claim 1: FIG. 1, FIG. 3, FIG. 6, FIG. 12).

Here, the fuel supply means (6) preferably communicates with the mixed fuel storage means (4) via a bypass line (Lb) branched from the fuel supply line (Lf). (Claim 2: FIG. 1, FIG. 3, FIG. 6). When such a configuration is adopted, the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine (1) is the bypass of the fuel mixture “a plurality of fuels (gas F1 to gas F4) having different heat generation amounts per unit amount”. The amount, that is, the amount of the mixed fuel supplied through the bypass line (Lb). In such a configuration, it is preferable to interpose a pump (8) for fuel supply in the bypass line (Lb). The pump (8) is preferably configured so that the discharge amount thereof can also be controlled. When the fuel supply pump (8) is provided in the bypass line (Lb), the pressure in the region between the pump (8) and the fuel valve (6) is measured,
When the pressure exceeds a predetermined value, it is necessary to stop the pump (8).

Alternatively, the fuel supply means (6) supplies a second fuel which communicates with a second fuel source (not shown) (which is constructed separately from the mixed fuel storage means 4 or the tank T4). It is preferably connected to the line (Lf2) (claim 3: FIG. 12). With such a configuration, the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine (1) is the fuel supplied from the “second fuel source” via the “second fuel supply line” (Lf2). It is determined by the supply amount of.

Here, when supplying liquid fuel, a pump is provided at the tip of the "second fuel supply line" (Lf2), and a head is added to the liquid fuel by the pump to control the supply amount. Is also good. In that case, the controlled physical quantities are the pressure of the pump, the (valve) opening of the fuel supply means (6) and the (valve) opening timing period.

The operation control method of the internal combustion engine (1) of the present invention having the above-mentioned structure is provided with the detecting means (exhaust pressure sensor 1
1, rotation sensor 12, power sensor 13, in-cylinder pressure sensor 1
4. Detection step (S1, S11, S21, S3) of detecting the operating state of the internal combustion engine (1) by the acceleration sensor 15)
1) and a determination step (S2, S12, S22, S3) for determining the suitability of the operating state from the state detected in the detection step.
3; S4, S14, S24, S36) and a supply amount control step (S3, S13, S3, S13, which adjusts the flow rate of the fuel supplied from the fuel supply means (6) to the intake system (2) based on the determination in the determination step. S23, S34; S5, S15, S2
5, S37), and (claim 4: FIGS. 1 to 1).
2).

For example, the detection sensor is an exhaust pressure sensor (11) or a rotation sensor (12), the presence / absence of a misfire is determined in the determination step (S2), and the exhaust pressure is determined in the supply amount control step (S3). When it is determined from the detection result of the sensor (11) or the rotation sensor (12) that misfire occurs (S2), control for increasing the flow rate of fuel supplied from the fuel supply means (6) to the intake system (2) ( S3) is performed (FIGS. 1 and 2).

Alternatively, the detection sensor is a power sensor (1
3), it is determined in the determination step (S12) whether or not the output of the internal combustion engine (1) is insufficient, and in the supply amount control step (S13), it is output from the detection result of the power sensor (13). When it is determined that the fuel consumption is insufficient (S12), control (S13) for increasing the flow rate of the fuel supplied from the fuel supply means (6) to the intake system is performed (FIGS. 3 and 4).

Alternatively, the detection sensor is a cylinder pressure sensor (1
4) or the acceleration sensor (15), the presence or absence of knocking is determined in the determination step (S22), and the detection result of the cylinder pressure sensor (14) or the acceleration sensor (15) in the supply amount control step (S23). When it is determined that knocking occurs more (S22), control (S23) for reducing the flow rate of the fuel supplied from the fuel supply means (6) to the intake system (2) is performed (FIGS. 6 and 7).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the accompanying drawings FIGS. Incidentally, FIG.
12A to 12C, the same parts are designated by the same reference numerals to avoid duplication of description.

In FIG. 1, which shows an outline of the configuration of the first embodiment, an internal combustion engine 1 has an intake system including an intake pipe 20 indicated by reference numeral 2 and an exhaust system E. The intake system 2 is provided with a mixer 3 at the tip of an intake pipe 20, and the mixer 3 communicates with an air supply line La and a fuel supply line Lf. The fuel supply line Lf communicates with the mixed fuel storage means 4, and the mixed fuel storage means 4 is supplied with a plurality of fuels having different calorific values per unit amount.

The mixed fuel storage means 4 supplies and mixes a plurality of fuels (four kinds of gaseous fuels F1 to F4 in the illustrated embodiment) having different calorific values to the tank T for storage. It is configured like.

A throttle valve 5 is provided on the internal combustion engine side of the intake pipe 20, and fuel is supplied to an intake system 2 in a region between the throttle valve 5 and the mixer 3. Is installed. The fuel supply means 6 branches from the fuel supply line Lf and communicates with a bypass line Lb having a fuel supply pump 8 interposed therebetween. Further, the fuel supply means 6 is equipped with a flow rate adjusting means 7 for adjusting the flow rate of fuel supplied from the fuel supply means 6 to the intake system 2.

On the other hand, an exhaust pressure sensor 11 is provided in the exhaust system E of the internal combustion engine 1, and a rotation speed sensor 12 is provided around the crank, and input signal lines LI are provided in the order of reference numerals.
1, control means via LI2, so-called "controller"
(Hereinafter, the control means is referred to as a controller) 9 is connected.

The controller 9 is the exhaust pressure sensor 1
1. Based on the input information from the rotation speed sensor 12, it is determined whether or not there is a misfire, and the flow rate adjusting means 7 provided in the fuel supplying means 6 is connected to the intake system 2 from the fuel supplying means 6 via the output signal line Lo. To regulate the flow rate of fuel supplied to
It is configured to send a control signal.

The control of the first embodiment will be described with reference to FIG. 2 and also to FIG. In step S1,
The exhaust pressure sensor 11 detects the exhaust pressure, and the rotation sensor 12 detects the rotation speed.

In step S2, the controller 9 determines whether the misfire or the operation is unstable based on the detection result of the exhaust pressure sensor or the rotation meter of the engine. When the controller 9 determines that the misfire or the operation is unstable (YES in step S2), the process proceeds to step S3,
When it is determined that the engine is not misfiring or the driving is not unstable (NO in step S2), the process returns to step S1.

In step S3, the controller 9 sends a signal via the output signal line Lo to the fuel adjusting means 7 provided in the fuel supply means 6 to control so as to increase the opening degree of the fuel valve.

Next, in step S4, the controller 9
Determines whether the misfire or the unstable driving condition has been resolved. If the misfire or the unstable driving condition is eliminated (YES in step S4), the process proceeds to step S5. If not eliminated (NO in step S4), the process returns to step S3.

In step S5, the controller 9 sends a signal to the fuel adjusting means 7 via the output signal line Lo, controls so as to maintain the opening of the fuel valve of the fuel supply means 6, and ends the processing.

According to the first embodiment having such a configuration and control method, the exhaust pressure sensor 11 or the engine rotation meter 12 constantly monitors the degree of misfire or the instability of the operation, and the misfire or the operation is performed. The gas engine can be controlled to avoid instability.

The second embodiment will be described with reference to FIGS. 3 and 4. In the second embodiment, for example, the output of the gas engine is measured by measuring the power generation amount (power generation) of a generator connected to the gas engine, and the power generation amount is stably controlled. The outline of the control is configured such that the power generation amount is detected by the power sensor 13 and the fuel valve opening is increased when the output is insufficient (until the insufficient output is resolved).

The configuration shown in FIG. 3 is obtained by only replacing the exhaust pressure sensor 11 and the engine rotation sensor 12 of the first embodiment shown in FIG. 1 with a power sensor 13, and other configurations and operational effects are shown in FIG. This is similar to the first embodiment of FIG.

The control of the second embodiment will be described in detail with reference to FIG. 4 and also to FIG. In step S11, the power sensor 13 detects the amount of power generation.

In step S12, the controller 9 determines from the detection result of the electric power sensor 13 whether or not the gas engine 1 is operating at a required output. When it is determined that the controller 9 is operating at the required output (OK in step S12), the process returns to step S11 and the detection of the power generation amount is repeated. When the gas engine 1 determines that the output is insufficient (insufficient in step S12), the process proceeds to step S13.

In step S13, the controller 9
Sends a signal via the output signal line Lo to the fuel adjusting means 7 provided in the fuel supply means 6 to control so as to increase the opening of the fuel valve.

In step S14, the controller 9 determines again whether the output is the required output. When it is determined that the controller 9 is operating with the required output (OK in step S14), the process proceeds to step S15, and when it is determined that the output is insufficient (insufficiency in step S14)
Returns to step S13 and continues to increase the opening degree of the fuel valve.

In step S15, the controller 9
Sends a signal to the fuel adjusting means 7 through the output signal line Lo, controls so as to maintain the opening degree of the fuel valve of the fuel supply means 6, and ends.

According to the second embodiment having such a configuration and control, the power sensor 13 monitors the power generation state of the generator G operated by the gas engine 1, and the controller 9 controls the fuel of the fuel supply means 6. By appropriately controlling the opening degree of the valve 7, it is possible to cope with the insufficient output of the gas engine 1 required for power generation.

Although the case where the output of the gas engine 1 is insufficient is dealt with in FIG. 4, the case where the output of the gas engine 1 is exceeded can also be dealt with in the second embodiment of FIG. The control when the output of the gas engine 1 exceeds will be described with reference to FIG.

In the control (flow chart) shown in FIG. 5, steps S11 and S15 are substantially the same as those in FIG. However, in the meantime (steps S12A to S12S)
14A) is different. That is, step S12A
In, the controller 9 determines from the detection result of the power sensor 13 whether the output of the gas engine 1 is proper (in other words, whether the gas engine 1 exceeds the proper output). When it is determined that the vehicle is operating at an appropriate output (OK in step S12A)
Returns to step S11 and repeats the detection of the power generation amount. On the other hand, when it is determined that the output of the gas engine 1 exceeds the appropriate range (excess in step S12A),
In step S13A, a signal is sent via the output signal line Lo to the fuel adjusting means 7 provided in the fuel supply means 6 to control the opening of the fuel valve.

If the opening degree of the fuel valve is reduced (step S13A), the controller 9 determines again in step S14A whether the output of the gas engine 1 is proper or not. If it is determined that the output of the gas engine 1 is appropriate (OK in step S14A), step S
If it is determined that the output exceeds the proper output (excess in step S14A), the process proceeds to step S1.
Return to 3A and continue to decrease the opening of the fuel valve. Others are the same as in the case of insufficient output described in FIG.

The third embodiment will be described with reference to FIGS. 6 and 7. In the third embodiment, knocking is detected by the in-cylinder pressure sensor 14 and the acceleration sensor 15, and if knocking is detected, control is performed to reduce the fuel valve opening degree (until knocking is suppressed). Is.

The configuration shown in FIG. 6 differs from that of FIG. 1 showing the configuration of the first embodiment in that an exhaust pressure sensor 11, an engine rotation sensor 12, an in-cylinder pressure sensor 14 and an acceleration sensor 15 are provided.
The configuration is the same as that of the first embodiment shown in FIG. 1.

The control of the third embodiment will be described in detail with reference to FIG. 7 and also with reference to FIG. In step S21, the in-cylinder pressure sensor 14 detects the in-cylinder pressure, and the acceleration sensor 15 detects the abnormal vibration of the cylinder.

In step S22, the controller 9 determines from the detection result of the in-cylinder pressure sensor 14 or the acceleration sensor whether knocking has occurred. If the controller 9 determines that knocking has occurred (YES in step S22), the process proceeds to step S23, and if it determines that knocking has not occurred (NO in step S22), the process returns to step S21 and steps S21, S22. repeat.

In step S23, the controller 9
Sends a signal via the output signal line Lo to the flow rate adjusting means 7 provided in the fuel supply means 6, and controls so as to reduce the opening degree of the fuel valve.

In step S24, the controller 9 determines whether knocking has been eliminated. If the controller 9 determines that knocking has been eliminated (YES in step S24), the process proceeds to step S25, and if it is determined that knocking has not been eliminated (NO in step S24), returns to step S23 and steps S23 and S24. repeat.

In step S25, the controller 9
Sends a signal to the flow rate adjusting means 7 through the output signal line Lo, controls so as to maintain the opening degree of the fuel valve of the fuel supply means 6, and ends.

According to the third embodiment having such a configuration and control, the cylinder pressure sensor 14 or the acceleration sensor 1
The abnormal vibration of the cylinder is monitored at 5, and if knocking occurs, it is possible to quickly respond to knocking and maintain smooth operation.

The fourth embodiment will be described with reference to FIGS. 8 and 9. In the fourth embodiment, the responsiveness to a load change is determined from the outputs of a sensor that detects a load on the load side and a sensor that measures a parameter indicating the responsiveness of the engine. The outline of the control is to increase the fuel valve opening degree so that when the load response is deteriorated, the deteriorated additional response is normalized.

In the configuration shown in FIG. 8, the exhaust pressure sensor 11 is omitted as compared with FIG. 1 showing the configuration of the first embodiment, but the generator G is provided with a power sensor 13.
Information is connected to the controller 9 via a signal transmission line L13. Further, a clock means (clock) 21 is coupled to the controller 9 via a clock pulse or a clock signal transmission line L18. The point that an engine rotation sensor 12 that measures the number of rotations of the engine is provided and other configurations are the same as those in the first embodiment of FIG. 1. Although not shown, the generator G may be provided with an ammeter, a voltmeter, or a frequency sensor instead of the engine rotation sensor 12.

The control of the fourth embodiment using the configuration shown in FIG. 8 will be described in detail with reference to FIG. Step S of FIG.
In 31, the physical quantity corresponding to the load on the load side or another load is detected, and the process proceeds to step S32. Step S
In 32, the controller examines the load responsiveness and proceeds to step S33. In step S33, the controller determines whether the load response has deteriorated.

Here, the examination / judgment of the load responsiveness (steps S32 and S33) will be described. In examining and judging the load responsiveness, first, the fluctuation of the load is detected by the fluctuation of the measurement result of the power sensor 13. When a load change is detected, the timekeeping means is started from that point. Here, if the load changes, the engine rotation sensor 1
The engine speed detected by 2 also changes. Measure the time from load fluctuation and examine the fluctuation amount of engine speed. Then, the time until the fluctuation of the engine speed becomes equal to that before the load fluctuation and becomes stable is measured. That is, the examination / judgment of the load responsiveness (steps S32 and S33) is performed based on the time (measured by the timing means 21) from the time of load fluctuation until the engine speed stabilizes.

When the load response is examined / determined (steps S32 and S33) by using an ammeter, a voltmeter, or a frequency sensor (not shown) (provided in the generator G), when the load changes. From this, the time until the current, voltage, or frequency of the generator G stabilizes (measured by the time measuring means 21) is obtained, and the examination / judgment is performed based on the time.

If it is determined that the load response is deteriorated (YES in step S33), step S34
And when it is determined that the situation has not deteriorated (step S3
3) returns to step S31 and NO in step S31.
31 to step S33 are repeated.

In step S34, the controller sends a signal through the output signal line to the fuel adjusting means provided in the fuel supply means to control the fuel valve so as to increase the opening degree of the fuel valve. Proceeding to the next step S35, the controller
The load is detected again, the load response is examined, and step S36 is performed.
Proceed to.

In step S36, the controller 9
Determines whether the load responsiveness has returned to normal, and when it has determined that the load responsiveness has returned to normal (YES in step S36).
S) proceeds to step S37, and when it is determined that it has not returned to normal (NO in step S37), the process returns to step S34 and steps S34 to S36 are repeated.
Regarding the examination of the load responsiveness (step S35) and the determination (step S36), as described above, the time from the change of the load until the engine speed stabilizes, or the current and the voltage of the generator G from the change of the load. Alternatively, it is performed based on the time until the frequency stabilizes.

In step S37, the controller sends a signal to the flow rate adjusting means through the output signal line, controls so as to maintain the opening degree of the fuel valve of the fuel supply means, and ends the processing.

According to the fourth embodiment having such a configuration and control, the load fluctuation is constantly monitored by the load sensor on the load side, and a sudden change in the load is detected promptly and the fuel valve is appropriately controlled. It is possible to improve the controllability of the internal combustion engine when the load changes suddenly.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 10 shows the configuration of the fifth embodiment. In the fifth embodiment, for example, the nitrogen oxide (NOx) concentration of the exhaust system E of the gas engine 1 is measured and the NOx concentration is controlled to a predetermined value (or an allowable limit value) or less. The outline of control is to set the NOx concentration to N
When the NOx concentration is detected by the Ox sensor 23 and exceeds the predetermined value, the fuel valve opening degree is decreased (until the concentration becomes equal to or lower than the predetermined value).

In the configuration shown in FIG. 10, the engine speed sensor 12 of the first embodiment shown in FIG. 1 is omitted, and the exhaust system E is provided with a NOx sensor 23 instead of the exhaust pressure sensor 11. Other configurations and operational effects are the same as those of the first embodiment shown in FIGS. 1 and 2.

The control of the fifth embodiment having the configuration shown in FIG. 10 will be described in detail with reference mainly to FIG. First, in step S41, the NOx sensor 23 detects the NOx concentration. Then, the controller 9 detects whether or not the detected NOx concentration exceeds a predetermined value (limit allowable value) (step S42). NO detected
When it is determined that the x concentration does not exceed the predetermined value (NO in step S42), the process returns to step S41 and steps S41 and S42 are repeated. On the other hand, the detected N
If it is determined that the Ox concentration exceeds the predetermined value (YES in step S42), the process proceeds to step S43.

In step S43, the controller 9
Sends a signal via the output signal line Lo to the flow rate adjusting means 7 provided in the fuel supply means 6, and controls so as to reduce the opening degree of the fuel valve. Then, in step S44, the controller 9 determines whether or not the detected NOx concentration is equal to or lower than a predetermined value. If the detected NOx concentration is less than or equal to the predetermined value, the process proceeds to step S45, and the detected Nx is still detected.
If it is determined that the Ox concentration exceeds the predetermined value (NO in step S44), the process returns to step S43 and steps S43 and S44 are repeated.

In step S45, the controller 9
Sends a signal to the flow rate adjusting means 7 through the output signal line Lo, controls so as to maintain the opening degree of the fuel valve of the fuel supply means 6, and ends.

Next, a sixth embodiment of the present invention will be described with reference to FIG. 1st Embodiment-5th Embodiment (FIG. 1)
11 to 11), a bypass line Lb, which is provided with a pump 8 branched from a fuel supply line Lf communicating with the tank 3 of the mixed fuel storage means 4 and communicates with the mixer 3, communicates with a fuel valve of the fuel supply means 6. The fuel valve opening is adjusted to control the bypass amount of the fuel gas (mixed gas). That is, the mixed fuel gas supplied to the mixer and the mixed fuel gas supplied from the fuel valve are the same.

On the other hand, in the embodiment of FIG. 12, the fuel valve of the fuel supply means 6 communicates with the fuel gas supply system (having the second fuel supply line Lf2) provided separately from the tank T. ing.

When the amount of fuel gas is insufficient (for example, misfire, insufficient output, deterioration of load responsiveness, etc.), the fuel valve opening is increased and the fuel gas from the system Lf2 different from the tank T is supplied. Increase supply.

When the amount of fuel gas is excessive (for example,
Knocking occurs), the fuel valve opening degree of the fuel supply means 6 is decreased, and the fuel gas supply amount from the system Lf2 different from the tank T is decreased.

Regarding the control, the same control as in the first to fifth embodiments can be performed. Other configurations and effects are similar to those of the embodiment shown in FIGS.

The illustrated embodiment is merely an example,
It does not limit the technical scope of the present invention. For example,
In the illustrated embodiment, "plural fuels having different calorific values"
Although all are gas fuels, they may be liquid fuels or the like.

[0067]

The effects of the present invention are listed below. (A) A gas engine can be controlled by an exhaust pressure sensor or an engine rotation meter so as to avoid misfire or unstable operation. (B) The power generation state of the generator is monitored by the power sensor, and it is possible to cope with insufficient output or excessive output of the gas engine required for power generation. (C) In-cylinder pressure sensor 14 or acceleration sensor 15
Abnormal vibration of the cylinder is constantly monitored by, and if knocking occurs, it is possible to quickly respond to knocking and maintain smooth operation. (D) The load fluctuation is monitored by the load sensor on the load side, so that the controllability at the time of a sudden change in load can be improved. (E) When the NOx concentration of the exhaust system exceeds a limit value (allowable value), this can be detected and control can be performed to reduce the NOx concentration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control flow of the first embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of a second embodiment of the present invention.

FIG. 4 is a flowchart showing control when the output is insufficient according to the second embodiment of the present invention.

FIG. 5 is a flowchart showing control at the time of excessive output according to the second embodiment of the present invention.

FIG. 6 is a block diagram showing the configuration of a third embodiment of the present invention.

FIG. 7 is a flowchart showing a control flow of a third embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 9 is a flowchart showing the flow of control of the fourth embodiment of the present invention.

FIG. 10 is a block diagram showing the configuration of a fifth embodiment of the present invention.

FIG. 11 is a flowchart showing a control flow of the fifth embodiment of the present invention.

FIG. 12 is a block diagram showing the configuration of a sixth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a conventional technique.

[Explanation of symbols]

1 ... Internal combustion engine 2 ... Intake system 3 ... mixer 4 ... Mixed fuel storage means 5 ... Throttle valve 6 ... Fuel supply means 7 ... Flow rate adjusting means 8 ... Fuel supply pump 9 ... Controller 11 ... Exhaust pressure sensor 12 ... Rotation sensor 13 ... Power sensor 14 ... In-cylinder pressure sensor 15 ... Acceleration sensor Lf ... Fuel supply line

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 21/02 F02M 21/02 301Q 311 311B (72) Inventor Teruhiro Sakurai 1-chome, Kaigan, Minato-ku, Tokyo No. 5-20 Tokyo Gas Co., Ltd. F term (reference) 3G092 AB12 BB20 DE11S FA03 HB01X HE01Z HE06Z HF01Z 3G301 HA24 JA03 MA01 PE01Z PF12Z

Claims (4)

[Claims] 1. A mixer is provided in an intake system, and an air supply line and a fuel supply line are connected to the mixer, the fuel supply line is connected to a mixed fuel storage means, and the mixed fuel storage means is connected to the mixed fuel storage means. A plurality of fuels having different calorific values per unit amount are respectively supplied, and a fuel supply means is provided in a region between the mixer and the throttle valve of the intake system and supplies the fuel to the intake system, and the fuel. A flow rate adjusting means for adjusting the flow rate of the fuel supplied from the supply means to the intake system and a control means are provided, and the control means responds to the detection means from the detection means for detecting the inconvenience of the operation of the internal combustion engine. An internal combustion engine configured to perform control for adjusting a flow rate of fuel supplied from a supply means to an intake system. 2. The internal combustion engine according to claim 1, wherein the fuel supply unit communicates with the mixed fuel storage unit via a bypass line branched from the fuel supply line. 3. The fuel supply means is connected to a second fuel supply line communicating with a second fuel source.
Internal combustion engine. 4. A method for controlling an internal combustion engine according to any one of claims 1 to 3, comprising a detection step of detecting an operating state of the internal combustion engine by a detection means, and a state detected in the detection step. And a supply amount control process for adjusting the flow rate of the fuel supplied from the fuel supply means to the intake system based on the judgment in the judgment process. Internal combustion engine operation control method.