JP3886949B2 - Gas engine fuel control device and fuel control method - Google Patents

Description

  The present invention is applied to a gas engine, particularly a torch ignition type gas engine, and a torch flame generated by igniting a gas charged in a sub chamber by a torch ignition device is injected into a lean mixed gas in a main combustion chamber, The present invention relates to a fuel control device and a fuel control method for a gas engine configured to burn the lean mixed gas.

  In the premixed lean combustion gas engine, the torch ignition system is installed in the sub chamber as a torch ignition method in which the torch flame generated by igniting the gas charged in the sub chamber with the torch ignition device is injected into the lean mixed gas in the main combustion chamber. Ignition plug ignition method in which a rich mixture ratio gas in the auxiliary chamber is ignited by an ignition plug and ignited, and this torch flame is injected into a lean mixed gas in the main combustion chamber to perform main combustion, and a pilot installed in the auxiliary chamber A pilot fuel injection ignition system is used in which pilot fuel is injected into a gas mixture in the auxiliary chamber by a fuel injection valve and ignited, and this torch flame is injected into a lean gas mixture in the main combustion chamber to cause main combustion. .

On the other hand, the main combustion chamber diffusion combustion system as disclosed in Non-Patent Document 1 (Journal of Japan Marine Engineering, Vol. 36, No. 9, 2001-9) is adopted for large gas engines.
The main combustion chamber diffusion combustion type gas engine disclosed in Non-Patent Document 1 includes a gas injection valve for injecting (injecting) high-pressure fuel gas into the main combustion chamber, and liquid pilot fuel of 8% or less of the total fuel. A high-pressure fuel gas from the gas injection valve and liquid pilot fuel from the pilot fuel injection valve are injected in the same direction, and into the diesel cycle by strong diffusion combustion in the main combustion chamber A near combustion cycle is achieved to improve the ignitability of the lean mixed gas and the thermal efficiency of the engine.

Journal of the Japan Marine Engineering Society Vol.36 No.9 2001-9

Among the torch ignition type gas engines, since the spark plug ignition type is spark discharge ignition of the spark plug, there is a problem that the increase of the in-cylinder effective average pressure is limited.
The pilot fuel injection ignition system can increase the effective in-cylinder pressure, but pilot fuel is injected and burned in the vicinity of TDC (top dead center). There is a problem that the amount of NOx generated increases as the fuel injection amount increases.

In the main combustion chamber diffusion combustion type gas engine disclosed in Non-Patent Document 1, high-pressure fuel gas and liquid pilot fuel are supplied from a gas injection valve and a pilot fuel injection valve that are mounted facing the main combustion chamber. Injecting in the same direction to achieve a combustion cycle close to the diesel cycle by strong diffusion combustion in the main combustion chamber, it is possible to increase the compression ratio and the maximum in-cylinder pressure to obtain high thermal efficiency, but the main combustion The flame propagation distance in the room becomes longer and the amount of NOx generated increases.
Moreover, in such a prior art, the loss of gas compression power for obtaining high-pressure fuel gas is inevitable, and the gas engine is lowered by the amount of such gas compression power loss.
And so on.

  Therefore, in view of the problems of the prior art, the present invention can increase the compression ratio and the maximum in-cylinder pressure without increasing knocking while suppressing the amount of NOx generated, and can achieve high thermal efficiency. It is an object of the present invention to provide an engine fuel control device and a fuel control method.

  The present invention achieves such an object, the first invention is to jet a torch flame generated by igniting a gas charged in a sub chamber by a torch ignition device into a lean mixed gas in a main combustion chamber, In a fuel control apparatus for a gas engine configured to combust the lean mixed gas, a pressurizing unit that pressurizes a high-concentration fuel gas to a predetermined pressure, and a pressure unit provided facing the main combustion chamber. Injection device having a gas injection valve for injecting a high concentration fuel gas toward the torch flame, and a control device for changing the injection timing of the high concentration fuel gas in the gas injection device based on operating conditions of the gas engine It is characterized by comprising.

  Here, in the first invention, as the operating condition of the gas engine, the rotational speed of the gas engine detected by the rotational speed detector and the load (output) of the gas engine detected by the load detector are used. Then, the rotational speed, load, and crank angle of the gas engine detected by the crank angle detector are input to the control device, and in the control device, the detected value of the engine speed and detection of the engine load are detected. Based on the detected value and the detected value of the crank angle, the injection timing of the high-concentration fuel gas corresponding to the detected value is calculated, and the gas injection device is driven according to the calculated value.

In the first aspect of the invention, the control device causes the high-concentration fuel gas injection start timing in the gas injection device to be the same as or delayed from the ignition timing of the sub-chamber gas by the torch ignition device. Injecting from the sub chamber toward the torch flame injected into the main combustion chamber,
Further, the control device is configured to adjust the injection amount of the high-concentration fuel gas by the gas injection device in relation to the main gas amount to the main combustion chamber controlled by the governor of the gas engine. Is good.

According to the first invention, in the intake stroke, a uniform premixed lean mixture is formed in the main combustion chamber at a concentration lower than the explosion limit gas concentration (for example, a concentration of about 3%), and the lean mixture is formed in the compression stroke. The gas in the sub chamber is ignited by the torch ignition device at an appropriate timing before the top dead center of the piston, the torch flame generated by the ignition is injected into the main combustion chamber, and the gas in the sub chamber by the torch ignition device is discharged. The gas injection device is operated by the controller so that the injection timing coincides with the ignition timing of the fuel injection or is delayed from the ignition timing, and the high-concentration fuel gas is supplied from the gas injection valve of the gas injection device into the main combustion chamber. Inject toward the torch flame.
The injection amount of the high-concentration fuel gas is changed according to the engine load in correspondence with the main gas amount to the main combustion chamber controlled by the governor, and the injection timing of the high-concentration fuel gas is determined by the engine speed and The injection amount and the injection timing are controlled so as to change depending on the engine load and prevent self-ignition in the main combustion chamber after the injection of the high-concentration fuel gas.

Therefore, according to the first invention, in the intake and compression strokes, a uniform premixed lean mixture having a concentration equal to or lower than the explosion limit gas concentration is previously formed in the main combustion chamber, and the subchamber is contained in the premixed lean mixture. A torch flame is ejected from the high-concentration fuel gas at a high speed from the gas injection valve of the gas injection device toward the torch flame.
Thus, the final premixing is performed by injecting a torch flame from the sub chamber into the premixed lean mixture formed in the main combustion chamber in the intake and compression strokes and injecting high-concentration fuel gas into the torch flame at high speed. The concentration can be formed immediately before combustion, the flame propagation distance is suppressed while avoiding the occurrence of knocking, and combustion with reduced NOx generation is performed.
In addition, the combustion mode provides a combustion cycle close to the diesel cycle, increases the compression ratio without increasing knocking, and increases the maximum in-cylinder pressure, thereby increasing the engine output. .

  In the first aspect of the invention, preferably, an in-cylinder pressure detector for detecting an in-cylinder pressure of the gas engine, and a detected value of the in-cylinder pressure input from the in-cylinder pressure detector, A combustion diagnostic device for determining a combustion abnormality, wherein the combustion diagnostic device determines a combustion abnormality in a combustion chamber based on a detected value of the in-cylinder pressure, and a combustion input from the combustion diagnostic device in the control device The injection timing of the high-concentration fuel gas is adjusted based on the abnormality determination result.

  If comprised in this way, the presence or absence of generation | occurrence | production of abnormal combustion, such as knocking and misfire, will be determined from the detected value of in-cylinder pressure by the combustion diagnostic device, and the injection timing of the high-concentration fuel gas and the torch ignition device will be based on this determination Since the ignition timing is adjusted, the amount of NOx generated is reduced while avoiding the occurrence of abnormal combustion such as knocking and misfire, and the compression ratio is increased and the maximum in-cylinder pressure is increased. High engine output is possible.

  According to a second aspect of the present invention, in the fuel control apparatus for the gas engine, a high-concentration fuel gas from the pressurizing means provided in the subchamber and a pressurizing unit that pressurizes the high-concentration fuel gas to a predetermined pressure. And a control device for delaying the gas injection start timing of the gas injection device simultaneously with or behind the ignition timing of the sub-chamber gas by the torch ignition device It is characterized by comprising.

  According to the second aspect of the present invention, the high-concentration fuel gas is ejected from the sub chamber into the main combustion chamber, and then the high-concentration fuel gas is ejected into the sub-combustion chamber. Fuel gas is dispersed and injected at high speed. As a result, as in the first aspect, the final premixed concentration can be formed immediately before combustion, the flame propagation distance is suppressed while avoiding the occurrence of knocking, and the amount of NOx generated is reduced. In addition to combustion, the compression ratio can be increased and the maximum in-cylinder pressure can be increased without causing knocking.

In the first and second aspects of the invention, the torch ignition device may be configured to inject pilot fuel from a pilot fuel injection valve into the gas in the sub chamber and torch the pilot fuel ignition type torch which is ejected to the main combustion chamber. Even if the ignition device is configured,
Alternatively, the torch ignition device may be configured as a spark ignition type torch ignition device in which the gas in the sub chamber is ignited by torch ignition by spark discharge of an ignition plug and ejected to the main combustion chamber, and the torch flame from the torch ignition device The high-concentration fuel gas is dispersed and injected at a high speed, so that the final premixed concentration can be formed immediately before combustion. This reduces the amount of NOx generated and increases the compression ratio and the cylinder. It is possible to increase the output of the engine whose internal maximum pressure has been increased.

  Furthermore, in the first and second inventions, the gas injection device is provided with a magnetostrictive actuator that opens and closes the gas injection valve by magnetostriction of a magnetostrictive material disposed in a magnetic field, and receives a control signal from the control device. It is preferable to transmit to the magnetostrictive actuator and to open and close the gas injection valve by the magnetostrictive actuator.

According to the present invention, the torch flame from the sub chamber is ejected into the premixed lean mixture formed in the main combustion chamber in the intake and compression strokes, and high concentration fuel gas is injected into the torch flame at high speed by dispersion. The final premixed concentration can be formed immediately before combustion, the flame propagation distance is suppressed, and combustion with reduced NOx generation is performed.
In addition, the combustion mode provides a combustion cycle close to the diesel cycle, increases the compression ratio without increasing knocking, and increases the maximum in-cylinder pressure, thereby increasing the engine output. At the same time, the thermal efficiency of the engine can be increased.
Further, the combustion diagnostic device determines whether or not abnormal combustion such as knocking or misfiring has occurred from the detected value of the in-cylinder pressure, and adjusts the injection timing of the high-concentration fuel gas and the ignition timing of the torch ignition device based on the determination result By doing this, while avoiding the occurrence of abnormal combustion such as knocking and misfire, the amount of NOx generated can be reduced as described above, and the compression ratio can be increased to increase the maximum in-cylinder pressure.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

  FIG. 1 is an overall configuration diagram of a fuel control device for a gas engine according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a gas injection valve and a giant magnetostrictive actuator. FIG. 3 is a cross-sectional view of the main part of the pilot fuel injection type torch ignition device, and FIG. 4 is a cross-sectional view of the main part of the spark ignition type torch ignition device. FIG. 5 is a control block diagram of the fuel control device. FIG. 6 shows a first example of a control flowchart of the fuel control device, and FIG. 7 shows a second example of the control flowchart. FIG. 8 is an injection timing diagram of the fuel control device. FIG. 9 shows a comparative example of the in-cylinder pressure diagram.

In FIG. 1 showing a fuel control apparatus according to an embodiment of the present invention, 100 is a gas engine, 45 is a piston of the gas engine 100, 46 is a crankshaft, 44 is a main combustion chamber, 41 is an intake valve, and 42 is an exhaust valve. , 43 are exhaust pipes.
Reference numeral 9 denotes an intake pipe that communicates with the intake valve 41. A gas injection device 10 that injects fuel gas into the air (intake air) flowing through the intake pipe 9 is provided in the middle of the pipe of the intake pipe 9. It has been. Reference numeral 13 denotes a gas supply pipe that connects a fuel gas tank (not shown) that stores fuel gas and the gas injection device 10. Reference numeral 7 denotes a gas supply electromagnetic valve provided at the inlet of the gas injection device 10 of the gas supply pipe 13. The gas supply electromagnetic valve 7 is opened and closed by a control signal from an electromagnetic valve control device (not shown) to increase the flow area of the gas supply pipe 13. In addition to adjustment, the flow path is blocked or the opening degree is controlled by a control signal from a combustion control device (not shown).

Reference numeral 11 denotes a torch ignition device for starting the gas engine 100, which will be described in detail later.
6 is a cylinder pressure detector that detects the gas pressure in the combustion chamber 44, that is, the cylinder pressure, 5 is a crank angle detector that detects the crank angle of the crankshaft 46, and 3 is the rotational speed of the gas engine 100. The rotation speed detector 4 detects a load (output) of the gas engine 100.
Reference numeral 60 denotes a combustion diagnostic device for determining whether or not there is a combustion abnormality in the combustion chamber 44 based on the detected value of the in-cylinder pressure input from the in-cylinder pressure detector 6.
Reference numeral 2 denotes a controller, the detected value of the engine speed from the rotational speed detector 3, the detected value of the engine load from the load detector 4, the detected value of the crank angle from the crank angle detector 5, and the combustion The determination result of the presence or absence of combustion abnormality is input from the diagnostic device 60, and arithmetic control as described later is performed based on these input signals.

A gas pressurizing pump 1 pressurizes high-concentration fuel gas fed through a fuel gas pipe 8 described later to a high pressure, and a reciprocating positive displacement high-pressure pump such as a known jerk fuel injection pump is preferable.
30 is a giant magnetostrictive actuator driven by a control signal from the controller 2, and 50 is a gas injection valve mounted facing the main combustion chamber 44, which will be described in detail later. The gas pressurizing pump 1, the giant magnetostrictive actuator 30, and the gas injection valve 50 constitute a gas injection device.
Reference numeral 8 denotes a fuel gas pipe connected from the gas pressurizing pump 1 and the giant magnetostrictive actuator 30 to the gas injection valve 50.

In FIG. 2 showing the details of the giant magnetostrictive actuator 30 and the gas injection valve 50,
The giant magnetostrictive actuator 30 is configured as follows.
A gas fuel reservoir 36 is pressurized by the gas pressurizing pump 1 and gas fuel is introduced through the gas fuel pipe 8. A valve body 31 opens and closes between the gas fuel reservoir 36 and the gas passage 8 a to the gas injection valve 50. 33 is a magnet (electromagnet), 32 is a giant magnetostrictive material that is displaced by magnetostriction, and the side is once fixed to a support portion at the base of the valve body 31, and the giant magnetostrictive material 32 is axially moved by energization of the magnet 33. The valve body 31 is reciprocated by displacing the valve body 31. Reference numeral 34 denotes a spring interposed between the support portion of the valve body 31 and the main body portion 35 of the actuator, and is biased in the direction in which the valve body 31 is closed.
The basic configuration itself of the giant magnetostrictive actuator 30 is known, and in this embodiment, the valve element 31 is connected to the giant magnetostrictive actuator 30 and is driven to open and close.

The gas injection valve 50 is configured as follows.
Reference numeral 56 denotes a valve body, 52 denotes one or more nozzle holes perforated at the tip of the valve body 56, and 55 denotes a gas reservoir communicated with the nozzle hole 52. A high concentration fuel gas from the giant magnetostrictive actuator 30 is introduced into the gas reservoir 55 through the fuel gas passage 8a.
A needle valve 51 is fitted in the valve body 56 so as to be slidable back and forth. 53 is a needle valve spring, 54 is a spring bearing for the needle valve spring 53, and the needle valve 51 is pressed in the valve closing direction via the spring bearing 54 by the spring force of the needle valve spring 53.

Next, as the torch ignition device 11, a pilot fuel injection type torch ignition device shown in FIG. 3 or a spark ignition type torch ignition device shown in FIG. 4 is used.
In FIG. 3 showing the pilot fuel injection type torch ignition device 11, 122 is a main body, 117 is a sub chamber base, and the sub chamber base 117 is fixed to the cylinder head 150 by tightening the main body 122 to the cylinder head 150. Has been.
111 is a sub chamber formed inside the sub chamber base 117, and 116 is one or a plurality of sub chamber nozzles communicating the sub chamber 111 and the main combustion chamber 44.
A pilot fuel injection valve 120 injects liquid fuel such as light oil introduced through the liquid fuel passage 121 into the sub chamber 111, and a known jerk type fuel injection valve is used.

  In the pilot fuel injection type torch ignition device 11, the pilot fuel injection valve 120 fills the sub chamber 111 with a pilot injection timing and an injection amount controlled by a pilot fuel injection control device (not shown). Liquid fuel (pilot fuel) is injected into the air-fuel mixture, and the air-fuel mixture is ignited and combusted to generate a torch flame 11a. The torch flame 11a is ejected from the sub-chamber nozzle 116 into the main combustion chamber 44.

In FIG. 4 showing the spark ignition type torch ignition device 11, 113 is a main body, 117 is a sub chamber base, and the sub chamber base 117 is fixed to the cylinder head 150 by fastening the main body 113 to the cylinder head 150. Has been.
111 is a sub chamber formed inside the sub chamber base 117, and 116 is one or a plurality of sub chamber nozzles communicating the sub chamber 111 and the main combustion chamber 44.
114 is a spark plug, and 115 is a fuel gas passage for supplying high concentration fuel gas for ignition into the sub chamber 111.
In the spark ignition type torch ignition device 11, spark discharge is performed on the high-concentration fuel gas introduced into the sub chamber 111 from the ignition plug 114 at an ignition timing controlled by an ignition control device (not shown). High-concentration fuel gas is ignited and combusted to generate a torch flame 11 a, and this torch flame 11 a is ejected from the sub-chamber nozzle 116 to the main combustion chamber 44.

Next, the fuel control apparatus for a gas engine having such a configuration is controlled by a first control method as shown in FIG. 6 and a second control method as shown in FIG.
In the first control method, based on the output signal of the governor, the supply amount of the high concentration fuel gas is calculated so as not to self-ignite in the main combustion chamber after the injection of the high concentration fuel gas (step 1).
Next, the combustion diagnostic device 60 determines whether or not abnormal combustion such as knocking or misfire has occurred for each cylinder based on the detected value of the in-cylinder pressure, and based on this determination result, for each cylinder, the abnormal combustion does not occur. The supply amount of the lean fuel gas is corrected (step 11), and the lean fuel gas is supplied during intake (step 2).

Next, at the end of the compression stroke, liquid fuel is injected from the pilot fuel injection valve 120 into the air-fuel mixture filled in the sub chamber 111 to ignite and combust the air-fuel mixture (the pilot fuel shown in FIG. 3). In the case of the injection type torch ignition device 11), a torch flame 11 a is generated, and this torch flame 11 a is ejected into the main combustion chamber 44 (step 3).
Next, at the same time as the torch ignition timing or at a timing delayed from the ignition timing, a gas jet 50a of high-concentration fuel gas passes through the fuel gas pipe 8 from the gas pressurizing pump 1 and passes through the giant magnetostrictive actuator 30. (See FIG. 1) is injected from the gas injection valve 50 toward the torch flame 11a (step 4). Even after the high-concentration fuel gas is injected, the in-cylinder pressure measurement by the in-cylinder pressure sensor is continued (step 12).
Further, as in the second control method shown in FIG. 7, combustion diagnosis based on the in-cylinder pressure detection value from the in-cylinder pressure sensor (in-cylinder pressure detector 6) in the first control method shown in FIG. It is also possible to omit this process.

Next, the operation of the first control method in the fuel control apparatus of the gas engine will be described in more detail with reference to FIG.
The detected value of the engine speed from the engine speed detector 3 and the detected value of the engine load from the load detector 4 are input to the combustion chamber gas concentration calculation unit 201 of the controller 2. The detected value of the in-cylinder pressure of each cylinder from the in-cylinder pressure detector 6 is input to the combustion diagnostic device 60.
Further, the output signal of the governor 101 is input to the main gas amount calculation unit 203 of the controller 2.

The main gas amount calculation unit 203 calculates a main gas amount that does not self-ignite in the main combustion chamber 44.
A combustion chamber gas concentration setting unit 202 sets a maximum gas concentration that does not cause knocking in the combustion chamber 44 for each engine speed and engine load.
In the combustion chamber gas concentration calculation unit 201, the maximum gas concentration corresponding to the detected values of the engine speed and engine load is selected from the combustion chamber gas concentration setting unit 202 and input to the injection gas amount calculation unit 204. .
The injection gas amount calculation unit 204 calculates the injection gas amount of the high concentration fuel gas based on the maximum gas concentration so as not to self-ignite in the main combustion chamber 44 after the injection of the high concentration fuel gas. Input to the opening / closing timing control unit 205.
207 is a pilot injection timing setting unit, and the injection timing of pilot injection in the sub chamber 111 is set for each engine speed and engine load.

In the gas injection valve opening / closing timing control unit 205, the crank angle detection value from the crank angle detector 5 and the pilot injection timing (injection start timing), that is, the ignition timing set in the pilot injection timing setting unit. As shown in FIG. 8, the high-concentration fuel gas injection timing (high-concentration fuel gas injection start timing) T ₂ from the gas injection valve 50 is set at the same time as the pilot injection timing T ₁ or pilot injection. become timing [Delta] T _G delayed from the timing T _1, and the produce a control signal such that the high concentration fuel gas injection period corresponding to the injection gas amount calculated by the injection gas amount calculating unit 204. Note that in FIG. 8, [Delta] T _P indicates a range of the pilot injection start timing.

The combustion diagnostic device 60 determines whether or not abnormal combustion such as knocking or misfiring has occurred from the detected value of the in-cylinder pressure, and inputs the determination result to the gas injection valve opening / closing timing control unit 205.
In addition to the control signal, the gas injection valve opening / closing timing control unit 205 controls the supply amount of the lean fuel gas for each cylinder so that the abnormal combustion does not occur based on the determination result of the combustion diagnostic device 60. Then, the correction control signal is output to the actuator control unit 206.
Therefore, since the supply amount of the high-concentration fuel gas is adjusted based on the determination result of the combustion diagnostic device 60, the generation amount of NOx is reduced while the occurrence of abnormal combustion such as knocking and misfire is avoided, and the compression ratio is increased. It is possible to increase the in-cylinder maximum pressure.

Wherein the actuator control unit 206, the high gas injection timing of the concentrated fuel gas (injection start timing of the high-concentration fuel gas) T ₂ and the operating timing by the magnet current super magnetostrictive actuator 30 corresponding to the high concentration fuel gas injection period And the operation period is calculated and output to the giant magnetostrictive actuator 30.
In the giant magnetostrictive actuator 30, the magnet 33 of the giant magnetostrictive actuator 30 is actuated at a magnet current value corresponding to the actuating timing and actuating period, so that the giant magnetostrictive material 32 resists the spring force of the spring 34 in the axial direction. As a result, the valve body 31 is displaced corresponding to the operation timing and operation period, and opens and closes between the gas fuel reservoir 36 and the gas passage 8a to the gas injection valve 50.
When the valve body 31 is opened, the high-concentration fuel gas in the gas fuel reservoir 36 flows into the gas reservoir 55 of the gas injection valve 50 through the gas passage 8a and overcomes the spring force of the needle valve spring 53. The needle valve 51 is opened, and a gas jet 50a is injected from the nozzle hole 52 toward the torch flame 11a formed in the main combustion chamber 44.

Therefore, according to this embodiment, in the intake and compression strokes, a uniform premixed lean mixture is previously formed in the main combustion chamber 44 at a concentration equal to or less than the explosion limit gas concentration, and the torch is formed in the premixed lean mixture. The torch flame 11 can be ejected from the sub chamber 111 of the ignition device 11, and the high-concentration fuel gas can be dispersed and injected at high speed from the gas injection valve 50 toward the torch flame 11a.
Thereby, the torch flame 11a from the sub chamber 111 is ejected into the premixed lean air-fuel mixture formed in the main combustion chamber 44 in the intake and compression strokes, and high-concentration fuel gas is dispersed and injected into the torch flame 11a at high speed. As a result, the final premixed concentration can be formed immediately before combustion, the flame propagation distance is suppressed while avoiding the occurrence of knocking, and combustion with reduced NOx generation is performed.
With this combustion mode, combustion close to the diesel cycle as shown in the in-cylinder pressure diagram of FIG. 9 (A) is changed from the conventional gas engine's Sabatate cycle as shown in the in-cylinder pressure diagram of FIG. 9 (B). A cycle is obtained, and the compression ratio can be increased and the in-cylinder maximum pressure Pmax can be increased without causing knocking. In FIG. 9, Pc is the compression pressure.

Further, in another embodiment of the present invention, as shown by a chain line in FIG. 3, a gas injection passage 70 opening to the sub chamber 111 is provided (71 is an opening end to the sub chamber 111). The passage 70 is connected to the giant magnetostrictive actuator 30 through the fuel gas pipe 8.
As in the first embodiment, the controller 2 controls the opening / closing timing of the giant magnetostrictive actuator 30 to start the injection of the high-concentration fuel gas that is injected from the gas injection passage 70 into the sub chamber 111. The ignition timing of the gas in the sub chamber 111 by the torch ignition device 11, that is, the injection timing (injection start timing) of the pilot injection is delayed or delayed from the ignition timing.
According to this embodiment, the torch flame 11a is ejected from the sub chamber 111 into the main combustion chamber 44, and then the high-concentration fuel gas is ejected into the sub chamber 111, thereby the torch flame 11a in the main combustion chamber 44. By high-speed dispersion injection of the high-concentration fuel gas from the sub chamber 111, the final premixed concentration can be formed immediately before combustion, as in the first embodiment.
As a result, the flame propagation distance in the main combustion chamber 44 is suppressed, combustion with reduced NOx generation is performed, and the compression ratio can be increased and the maximum in-cylinder pressure can be increased without observing the occurrence of knocking. It becomes.

  According to the present invention, a gas engine that suppresses the amount of NOx generated and increases the compression ratio and the in-cylinder maximum pressure while avoiding the occurrence of knocking to obtain high thermal efficiency, and enabling high output. Can be provided.

1 is an overall configuration diagram of a fuel control device for a gas engine according to an embodiment of the present invention. It is a block diagram of a gas injection valve and a giant magnetostrictive actuator. It is principal part sectional drawing of a pilot fuel injection type torch ignition device. It is principal part sectional drawing of a spark ignition type torch ignition device. It is a control block diagram of the fuel control device. It is a 1st example of the control flowchart of the said fuel control apparatus. It is a 2nd example of a control flowchart. It is an injection timing diagram of the fuel control device. The comparative example of a cylinder pressure diagram is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas pressurization pump 2 Controller 3 Rotation speed detector 4 Load detector 5 Crank angle detector 6 In-cylinder pressure detector 9 Intake pipe 10 Gas injection device 11 Torch ignition device 30 Giant magnetostriction actuator 44 Main combustion chamber 45 Piston 46 Crank Shaft 50 Gas injection valve 60 Combustion diagnostic device 100 Gas engine

Claims (11)

  Fuel control of a gas engine configured to inject a torch flame generated by igniting a gas charged in a sub chamber with a torch ignition device into a lean mixed gas in the main combustion chamber and burn the lean mixed gas In the apparatus, a pressurizing unit that pressurizes the high-concentration fuel gas to a predetermined pressure, and a gas injection valve that is provided facing the main combustion chamber and ejects the high-concentration fuel gas from the pressurization unit toward the torch flame A fuel control device for a gas engine, comprising: a gas injection device including: a control device that changes an injection timing of the high-concentration fuel gas in the gas injection device based on operating conditions of the gas engine.   The controller is configured to delay the injection start timing of the high-concentration fuel gas in the gas injection device simultaneously with or behind the ignition timing of the sub-chamber gas by the torch ignition device. The fuel control device for a gas engine according to claim 1, wherein   The control device is configured to adjust an injection amount of the high-concentration fuel gas by the gas injection device in relation to a main gas amount to the main combustion chamber controlled by a governor of the gas engine. The fuel control apparatus for a gas engine according to claim 1.   A rotation speed detector for detecting the rotation speed of the gas engine; a load detector for detecting a load (output) of the gas engine; and a crank angle detector for detecting a crank angle of the gas engine; The apparatus is based on a detection value of the engine speed input from the rotation speed detector, a detection value of the engine load input from the load detector, and a detection value of the crank angle input from the crank angle detector. 2. The fuel for a gas engine according to claim 1, wherein the fuel injection fuel gas is configured to calculate an injection timing of the high-concentration fuel gas corresponding to the detected values and drive the gas injection device according to the calculated values. Control device.   An in-cylinder pressure detector that detects an in-cylinder pressure of the gas engine, and a combustion diagnostic device that determines a combustion abnormality in the combustion chamber based on a detected value of the in-cylinder pressure input from the in-cylinder pressure detector. The control device is configured to adjust the injection timing of the high-concentration fuel gas from the gas injection device based on the determination result of the combustion abnormality input from the combustion diagnostic device. Item 2. A fuel control device for a gas engine according to Item 1.   Fuel control of a gas engine configured to inject a torch flame generated by igniting a gas charged in a sub chamber with a torch ignition device into a lean mixed gas in the main combustion chamber and burn the lean mixed gas In the apparatus, a gas having pressurizing means for pressurizing the high-concentration fuel gas to a predetermined pressure, and a gas injection valve that is provided facing the sub chamber and jets the high-concentration fuel gas from the pressurization means into the sub chamber. A fuel for a gas engine, comprising: an injection device; and a control device that delays a gas ejection start timing of the gas injection device simultaneously with or behind the ignition timing of the sub-chamber gas by the torch ignition device Control device.   The torch ignition device is configured as a pilot fuel ignition type torch ignition device that injects pilot fuel into a gas in the sub chamber from a pilot fuel injection valve, ignites the torch, and jets it to the main combustion chamber. The fuel control device for a gas engine according to any one of claims 1 and 6.   7. The torch ignition device is configured as a spark ignition type torch ignition device in which gas in the sub chamber is ignited by a torch by a spark discharge of an ignition plug and ejected to the main combustion chamber. The fuel control device for a gas engine according to any one of the above.   The gas injection device includes a magnetostrictive actuator that opens and closes the gas injection valve by magnetostriction of a magnetostrictive material disposed in a magnetic field, and the magnetostriction actuator opens and closes the gas injection valve by a control signal from the control device. The fuel control device for a gas engine according to claim 1, wherein the fuel control device is a gas engine.   Fuel control in a gas engine configured to inject a torch flame generated by igniting a gas charged in a sub chamber with a torch ignition device into a lean mixed gas in the main combustion chamber and combust the lean mixed gas In the method, high-concentration fuel gas pressurized to a predetermined pressure is jetted from the sub chamber into the main combustion chamber at the same time as or after the ignition timing of the sub chamber gas by the torch ignition device. A fuel control method for a gas engine, wherein the fuel is injected toward a torch flame.   Detecting in-cylinder pressure of the gas engine, determining combustion abnormality in the combustion chamber based on the detected value of the cylinder pressure, and adjusting the injection timing of the high-concentration fuel gas based on the determination result of the combustion abnormality The fuel control method for a gas engine according to claim 10, wherein:

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