JP2011127543A - Gas engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas engine control device capable of controlling an air-fuel mixture to a proper air-fuel ratio, even if the outside air temperature varies. <P>SOLUTION: This gas engine control device includes an engine speed control part 111b for determining an engine speed command value NeO from a load Ld input to a load device and controlling the opening of a throttle valve based on the deviation between an engine speed Ne and the engine speed command value NeO, and an air-fuel mixture flow rate control part 111c for determining an air-fuel mixture flow rate command value QmixO from the load Ld and the engine speed command value NeO, calculating air-fuel mixture viscosity μ<SB>T1</SB>based on the air-fuel mixture temperature T1 and air-fuel mixture viscosity μ<SB>0</SB>at 0°C, calculating a viscosity corrected actual air-fuel mixture flow rate QmixR based on the air-fuel mixture temperature T1, the air-fuel mixture viscosity μ<SB>T1</SB>, air-fuel mixture pressure P1, an engine speed Ne, filling efficiency η<SB>c</SB>and the stroke volume V<SB>s</SB>and controlling opening of a fuel gas control valve based on the deviation between the air-fuel mixture flow rate command value QmixO and the viscosity corrected actual air-fuel mixture flow rate QmixR. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas engine control device.

  Conventionally, a gas engine that is burned and operated using a fuel gas such as natural gas or city gas maintains an optimal combustion state in which knocking or misfire does not occur and suppresses NOx contained in exhaust gas. The ratio of the flow rate of the outside air (air) and the flow rate of the fuel gas (outside air flow rate / fuel gas flow rate) (hereinafter simply referred to as “air-fuel ratio”) is adjusted according to the characteristics of the fuel gas used. Gas engine control devices are known.

In such a configuration, as disclosed in Patent Document 1, for example, the gas engine is optimized for the flow rate of the fuel gas determined from the target rotation speed and output (hereinafter simply referred to as “fuel gas flow rate command value”). Calculates the flow rate (hereinafter simply referred to as “mixture flow rate command value”) of the supply air (hereinafter simply referred to as “mixture”) mixed with outside air at an air-fuel ratio, and is calculated from the mixture temperature and mixture pressure. Some have an air-fuel ratio control process for setting a target opening of the throttle valve based on a deviation between the flow rate of the air-fuel mixture (hereinafter simply referred to as “actual air-fuel flow rate”) and the air-fuel mixture flow rate command value. In this gas engine, the actual mixed gas flow rate Qmix (1 / sec) is determined by the following: supply air temperature (manifold temperature) T1 (K), supply air pressure (manifold pressure) P1 (kPa), charging efficiency ηc, stroke volume V _s , Further, based on the engine speed Ne (1 / sec), it is calculated from the following formula 3.

However, the above method has the following problems.
In general, the flow rate Q of a fluid flowing in a circular tube having a radius R and a length L is calculated from the following equation 4 derived from Hagen-Poiseuille's law based on the fluid viscosity μ _T and the pressure loss ΔP. Here, the fluid viscosity μ _T is calculated based on the fluid viscosity μ _{0 at} 0 ° C. and the fluid temperature T from the following formula 5 derived from Sutherland's empirical formula. Therefore, when the fluid temperature T varies, the flow rate Q flowing through a predetermined Pipe varies due to the influence of the fluid viscosity mu _T calculated from the fluid temperature T. Thereby, the knowledge is obtained that the flow rate of the air-fuel mixture, which is a fluid, is influenced by the air-fuel mixture viscosity calculated from the air-fuel mixture temperature.

On the other hand, the actual mixture flow rate Qmix calculated by Equation 3 does not take into account the influence of the mixture viscosity μ _T1 determined by the mixture temperature (manifold temperature) T1. However, in the air-fuel mixture actually supplied, the air-fuel mixture temperature (manifold temperature) T1 varies depending on the temperature of the outside air. That is, since the air-fuel mixture viscosity μ _T1 varies, an error occurs between the actual air-fuel mixture flow rate Qmix and the actually supplied air-fuel mixture flow rate. As a result, even when the opening degree of the throttle valve is set to the target opening degree that is set based on the deviation between the actual air-fuel mixture flow rate Qmix and the air-fuel mixture flow rate command value, the air-fuel mixture having an appropriate air-fuel ratio is supplied. There was a problem that could not be.

JP 2009-57873 A

  The present invention has been made in view of such problems, and an object of the present invention is to provide a gas engine control device capable of controlling the air-fuel mixture to an appropriate air-fuel ratio even when the temperature of the outside air varies.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, the invention of claim 1 is a mixture temperature detecting means for detecting the mixture temperature T1, a mixture pressure detecting means for detecting the mixture pressure P1, and an engine speed detecting means for detecting the engine speed Ne. An engine that determines an engine speed command value from a load applied to a load device driven by the engine, and controls an opening degree of the throttle valve based on a deviation between the engine speed Ne and the engine speed command value The mixture flow rate command value is calculated from the rotation number control means, the load, and the engine rotation number command value, and is shown in the following _equation 1 based on the mixture temperature T1 and the mixture viscosity μ ₀ at 0 ° C. calculating the mixture viscosity _{mu T1,} the gas mixture temperature T1, the mixture viscosity _{mu T1,} the air-fuel mixture pressure P1, the engine speed Ne, the charging efficiency eta _c, and stroke volume _{V s} based on The viscosity corrected actual mixture flow rate QmixR shown in the following equation 2 is calculated, and the opening degree of the fuel gas control valve is controlled based on the deviation between the mixture flow rate command value and the viscosity corrected actual mixture flow rate QmixR. And a mixture flow rate control means.

  As effects of the present invention, the following effects can be obtained.

According to the first aspect of the present invention, an error between the mixture flow rate calculated by the engine control device and the actually supplied mixture flow rate can be reduced. As a result, it is possible to control the air-fuel mixture in the appropriate air-fuel ratio, the O ₂ concentration that O ₂ concentration in the ambient air by variations in the temperature of the outside air contained in the mixed gas be varied does not change. That is, the NOx concentration discharged from the gas engine is not affected by the temperature of the outside air.

The figure which shows the structure of the gas engine which concerns on one Embodiment of this invention. The flowchart figure which shows the control process of the gas engine control apparatus which concerns on one Embodiment of this invention. The flowchart figure which shows the air-fuel | gaseous mixture flow rate control process of the gas engine control apparatus which concerns on one Embodiment of this invention. The flowchart figure which shows the air-fuel | gaseous mixture flow rate control process of the gas engine control apparatus which concerns on one Embodiment of this invention. The figure which shows the graph showing the effect by the air-fuel | gaseous mixture flow rate control process of the gas engine control apparatus which concerns on one Embodiment of this invention. (A) shows a graph representing the O ₂ concentration in the mixture by the gas engine control apparatus according to an embodiment of the present invention. (B) The figure which shows the graph showing the NOx density | concentration contained in the exhaust_gas | exhaustion by the gas engine control apparatus which concerns on one Embodiment of this invention.

  Hereinafter, a gas engine control apparatus 100 according to an embodiment of the gas engine control apparatus of the present invention and a gas engine 1 that is an internal combustion engine to which the gas engine control apparatus 100 is applied will be described with reference to FIG. In this embodiment, “upstream side” indicates the upstream side in the flow direction of the air-fuel mixture, and “downstream side” indicates the downstream side in the flow direction of the air-fuel mixture. Further, the upper and lower directions are defined with the direction in which the piston 13 compresses the air-fuel mixture as the upward direction.

  As shown in FIG. 1, the gas engine 1 is a single-cylinder engine or a multi-cylinder engine, and performs a combustion operation using a fuel gas such as natural gas. The gas engine 1 mainly includes an engine body 10, an air supply path 20, an exhaust path 30, and a fuel gas supply path 40. The gas engine 1 is configured such that an output shaft (not shown) is connected to a generator 50 that is a load device, and the generator 50 is operated. In addition, the load apparatus which the gas engine 1 operates is not limited to the generator 50 in this embodiment.

  The engine main body 10 has a cylinder head 12 fixed to an upper portion of a cylinder block 11 which is a main constituent member. In the engine main body 10, a piston 13 is slidably housed in a cylinder 10 a formed in a cylinder block 11, and a combustion chamber 14 is formed above the piston 13 in the cylinder. The cylinder head 12 includes an air supply valve 15 that communicates or blocks the air supply path 20 and the combustion chamber 14, an ignition plug 16 that ignites the air-fuel mixture supplied to the combustion chamber 14, and an exhaust path 30 and the combustion chamber 14. Is provided with an exhaust valve 17 for communicating or shutting off. A crankshaft 19 connected to the engine body 10 via a piston 13 and a connecting rod 18 is rotatably supported. The engine body 10 is configured to convert the reciprocating motion of the piston 13 into a rotational motion by the crankshaft 19 and to output to the generator 50 via an output shaft (not shown).

  The air supply path 20 supplies the engine body 10 with a mixture of outside air (air) and fuel gas. The air supply path 20 includes an air supply pipe 21, a venturi 22, a throttle valve 23, and the like.

  The air supply pipe 21 is a main structural member of the air supply path 20. One of the air supply pipes 21 communicates with the combustion chamber 14 of the engine body 10 via the air supply valve 15 and the other is released to the atmosphere. Therefore, the supply pipe 21 is configured to be able to supply outside air into the combustion chamber 14. A fuel gas supply path 40 is connected to the supply pipe 21 in the middle thereof.

  The venturi 22 generates a differential pressure between the fuel gas in the fuel gas supply path 40 and the air in the air supply pipe 21. The venturi 22 is provided at a connection portion of the fuel gas supply path 40 in the air supply pipe 21. The venturi 22 is configured to be able to supply the fuel gas in the fuel gas supply path 40 into the air supply pipe 21 by the differential pressure generated in the air supply pipe 21.

  The throttle valve 23 changes the flow rate of the air-fuel mixture. The throttle valve 23 is provided on the downstream side of the venturi 22 in the air supply pipe 21. The throttle valve 23 is an automatic valve that can be opened and closed by an actuator such as an electric motor. The throttle valve 23 can change the flow rate of the air-fuel mixture supplied to the engine body 10 by adjusting the opening thereof.

  The exhaust path 30 is for exhausting the exhaust discharged from the engine body 10 to the outside after performing a NOx reduction process or the like. The exhaust path 30 includes an exhaust pipe 31, a filter (not shown), an oxidation catalyst, and the like.

  The exhaust pipe 31 is a main structural member of the exhaust path 30. One of the exhaust pipes 31 communicates with the combustion chamber 14 of the engine body 10 via the exhaust valve 17, and the other is released to the atmosphere via a filter, an oxidation catalyst, etc. (not shown). Therefore, the exhaust pipe 31 is configured to be able to exhaust the exhaust gas in the combustion chamber 14 to the outside.

  The fuel gas supply path 40 supplies fuel gas to the air supply path 20. The fuel gas supply path 40 includes a fuel gas supply pipe 41, a fuel gas control valve 42, and the like.

  The fuel gas supply pipe 41 is a main structural member of the air supply path 20. One of the fuel gas supply pipes 41 is connected to the air supply pipe 21 of the air supply path 20, and the other is connected to a fuel gas tank (not shown) that stores fuel gas. Therefore, the fuel gas supply pipe 41 is configured to be able to supply fuel gas in a fuel gas tank (not shown) into the air supply pipe 21.

  The fuel gas control valve 42 supplies or stops the supply of the fuel gas, and changes the supply amount of the fuel gas. The fuel gas control valve 42 is provided in the middle of the fuel gas supply pipe 41. The fuel gas control valve 42 is an automatic valve that can be opened and closed by an actuator such as an electric motor. The fuel gas control valve 42 can change the flow rate of the supplied fuel gas by supplying or stopping the supply of the fuel gas to the air supply path 20 by opening and closing the valve and adjusting the opening of the valve.

  As shown in FIG. 1, the gas engine control device 100 controls the operation of the gas engine 1. The gas engine control apparatus 100 mainly includes an ECU 110, an engine speed detection sensor 120 as an engine speed detection means, a temperature detection sensor 130 as a mixture temperature detection means, and a pressure detection sensor 140 as a mixture pressure detection means. To do.

The ECU 110 stores various programs for controlling the gas engine 1 and data such as the air-fuel ratio map M1, the charging efficiency η _c , the stroke volume V _s of the gas engine 1, and develops these programs. It is possible to perform predetermined calculations according to these programs and the like, and it is possible to store the results of the calculations.

  The ECU 110 may actually have a configuration in which a CPU, a ROM, a RAM, an HDD, and the like are connected by a bus, or may be configured by a one-chip LSI or the like. In the present embodiment, it can be achieved by using a dedicated product or by storing the above-described program in a commercially available personal computer or workstation. The ECU 110 mainly includes a control unit 111, an input unit 112, an output unit 113, and the like.

  Functionally, the control unit 111 includes a storage unit 111a, an engine speed control unit 111b which is an engine speed control unit, and an air-fuel mixture flow control unit 111c which is an air-fuel mixture flow control unit. Substantially, the control unit 111 performs functions such as a storage unit 111a, an engine speed control unit 111b, and an air-fuel mixture flow rate control unit 111c by performing predetermined calculations and the like according to a program stored in the storage unit 111a. Fulfill.

Of the control unit 111, the storage unit 111a and the engine speed control unit 111b cooperate to perform each process constituting one embodiment of the gas engine control device 100 according to the present invention. Of the control unit 111, the storage unit 111a and the air-fuel mixture flow rate control unit 111c cooperate to perform each process constituting one embodiment of the gas engine control device 100 according to the present invention.
Specific functions of the storage unit 111a, the engine speed control unit 111b, and the mixture flow rate control unit 111c will be described later.

  The input unit 112 is connected to the control unit 111, and the engine speed detection sensor 120, the temperature detection sensor 130, the pressure detection sensor 140, and signals and command values from the generator 50 that is a load device are input to the control unit 111. It is what is done.

  The output unit 113 is connected to the control unit 111, and outputs signals from the control unit 111 to the fuel gas control valve 42, the throttle valve 23, and the spark plug 16.

  The engine speed detection sensor 120 detects the engine speed Ne. The engine speed detection sensor 120 includes a rotary encoder or the like, and is provided on the crankshaft 19 of the gas engine 1 or the like. The engine speed detection sensor 120 is a rotary encoder in the present embodiment, but is not particularly limited to this, and any sensor that can detect the engine speed Ne may be used.

  The temperature detection sensor 130 detects the mixture temperature T1. The temperature detection sensor 130 is disposed in the middle of the air supply pipe 21 and downstream of the throttle valve 23. Note that the positions where the temperature detection sensors 130 are arranged and the number of the temperature detection sensors 130 are not particularly limited in the present embodiment, and may be any configuration as long as the mixture temperature T1 can be appropriately detected.

  The pressure detection sensor 140 detects the air-fuel mixture pressure P1. The pressure detection sensor 140 is disposed in the middle of the air supply pipe 21 and in the vicinity of the temperature detection sensor 130. Note that the positions at which the pressure detection sensors 140 are arranged and the number of the pressure detection sensors 140 are not particularly limited in the present embodiment, and any configuration that can appropriately detect the air-fuel mixture pressure P1 may be used.

  As shown in FIG. 1, the input unit 112 of the ECU 110 is connected to the engine speed detection sensor 120 and can acquire the engine speed Ne detected by the engine speed detection sensor 120.

  The input unit 112 of the ECU 110 is connected to the temperature detection sensor 130, and can acquire the mixture temperature T1 detected by the temperature detection sensor 130.

  The input unit 112 of the ECU 110 is connected to the pressure detection sensor 140, and can acquire the air-fuel mixture pressure P1 detected by the pressure detection sensor 140.

  The input unit 112 of the ECU 110 is connected to a generator 50 that is a load device, and can acquire a load Ld that is input to the generator 50.

  The output unit 113 of the ECU 110 is connected to the ignition plug 16 via an ignition device (not shown), and can transmit an ignition signal of the ignition plug 16.

  The output unit 113 of the ECU 110 is connected to the throttle valve 23 and can transmit a setting signal for the opening degree of the throttle valve 23.

  The output unit 113 of the ECU 110 is connected to the fuel gas control valve 42 and can transmit a setting signal for the opening degree of the fuel gas control valve 42.

  Below, the control aspect of the gas engine control apparatus 100 which concerns on this invention is demonstrated using FIG.2, FIG.3 and FIG.4.

  As shown in FIG. 2, the control mode of the gas engine control apparatus 100 according to the present invention includes an engine speed control process A and a mixture flow rate control process B.

  In the engine speed control process A, the engine speed command value NeO is determined from the load Ld by the cooperation of the storage section 111a and the engine speed control section 111b in the control section 111, and the engine speed Ne and This is a stroke for controlling the opening degree of the throttle valve 23 based on the deviation from the engine speed command value NeO.

In the mixture flow rate control step B, the mixture portion flow rate command value QmixO is calculated from the load Ld and the engine speed command value NeO by the cooperation of the storage unit 111a and the mixture flow rate control unit 111c in the control unit 111. decide. Next, based on the mixture temperature T1 and the mixture viscosity μ ₀ at 0 ° C., the mixture viscosity μ _T1 shown in the following Equation ₁ is calculated. Further, based on the calculated mixture viscosity μ _T1 , mixture temperature T1, mixture pressure P1, engine speed Ne, charging efficiency η _c , and stroke volume V _s , the viscosity corrected actual mixture flow rate shown in the following equation 2 QmixR is calculated. Then, the opening degree of the fuel gas control valve 42 is controlled based on the deviation between the mixture flow rate command value QmixO and the viscosity corrected actual mixture flow rate QmixR.

  Below, the control aspect of the throttle valve 23 and the fuel gas control valve 42 by ECU110 is demonstrated.

  In step S100, the ECU 110 starts an engine speed control process A and shifts the control stage to step S110 (see FIG. 3).

  As shown in FIG. 3, in step S <b> 110, the ECU 110 acquires the load Ld input to the generator 50 that is the load device and the engine speed Ne detected by the engine speed detection sensor 120 through the input unit 112. . ECU110 memorize | stores the load Ld and the engine speed Ne which the input part 112 acquired in the memory | storage part 111a of the control part 111, and transfers a control step to step S120.

  In step S120, the ECU 110 determines the engine speed command value NeO by the engine speed control unit 111b of the control unit 111 based on the load Ld and the air-fuel ratio map M1 stored in the storage unit 111a of the control unit 111. To do. The ECU 110 stores the engine speed command value NeO determined by the engine speed control unit 111b of the control unit 111 in the storage unit 111a of the control unit 111, and then shifts the control stage to step S130.

In step S130, the ECU 110 determines whether the engine speed Ne stored in the storage unit 111a of the control unit 111 is equal to the engine speed command value NeO by the engine speed control unit 111b of the control unit 111.
As a result, when it is determined that the engine speed Ne is equal to the engine speed command value NeO, the ECU 110 ends the engine speed control process A and shifts the control stage to step S200 (see FIG. 2).
If it is determined that the engine rotational speed Ne is not equal to the engine rotational speed command value NeO, the ECU 110 proceeds to a control step to step S140.

In step S140, the ECU 110 determines whether the engine speed Ne stored in the storage unit 111a of the control unit 111 is larger than the engine speed command value NeO by the engine speed control unit 111b of the control unit 111.
As a result, when it is determined that the engine speed Ne is larger than the engine speed command value NeO, the ECU 110 proceeds to a control step to step S150.
If it is determined that the engine rotational speed Ne is smaller than the engine rotational speed command value NeO, the ECU 110 proceeds to a control step to step S160.

  In step S150, the ECU 110 controls the throttle valve based on the difference between the engine speed Ne stored in the storage unit 111a of the control unit 111 and the engine speed command value NeO by the engine speed control unit 111b of the control unit 111. An opening correction amount SvH of 23 is calculated. The ECU 110 controls the engine speed control unit 111b of the control unit 111 so that the opening degree of the throttle valve 23 is decreased by the opening correction amount SvH via the output unit 113, and then ends the engine speed control process A. Then, the control stage proceeds to step S200 (see FIG. 2).

  In step S160, the ECU 110 controls the throttle valve based on the deviation between the engine speed Ne stored in the storage unit 111a of the control unit 111 and the engine speed command value NeO by the engine speed control unit 111b of the control unit 111. An opening correction amount SvH of 23 is calculated. The ECU 110 controls the engine speed control unit 111b of the control unit 111 to increase the opening of the throttle valve 23 by the opening correction amount SvH via the output unit 113, and then ends the engine speed control process A. Then, the control stage proceeds to step S200 (see FIG. 2).

  As shown in FIG. 2, in step S200, the ECU 110 starts an air-fuel mixture flow rate control step B, and the control stage proceeds to step S210 (see FIG. 4).

  As shown in FIG. 4, in step S210, the ECU 110 causes the mixture flow rate control unit 111c of the control unit 111 to store the load Ld, the engine speed command value NeO, and the air-fuel ratio that are stored in the storage unit 111a of the control unit 111. A mixture flow rate command value QmixO is determined based on the map M1. The ECU 110 stores the mixture flow rate command value QmixO determined by the mixture flow rate control unit 111c of the control unit 111 in the storage unit 111a of the control unit 111, and then shifts the control stage to step S220.

  In step S220, the ECU 110 causes the input unit 112 to detect the engine speed Ne detected by the engine speed detection sensor 120, the mixture temperature T1 detected by the temperature detection sensor 130, and the mixture pressure P1 detected by the pressure detection sensor 140. To get. The ECU 110 stores the engine speed Ne, the mixture temperature T1, and the mixture pressure P1 acquired by the input unit 112 in the storage unit 111a of the control unit 111, and then shifts the control step to step S220.

In step S230, the ECU 110 causes the mixture flow rate control unit 111c of the control unit 111 to store the engine speed Ne, the mixture temperature T1, and the mixture viscosity μ _{0 at} 0 ° C. stored in the storage unit 111a of the control unit 111. Based on the above, the air-fuel mixture viscosity μ _T1 shown in the above equation ₁ is calculated. ECU110 After storing the mixture viscosity _{mu T1} of the gas mixture flow rate control unit 111c is calculated in the control unit 111 in the storage unit 111a of the control unit 111 shifts the control step to a step S240.

In step S240, the ECU 110 causes the mixture flow rate control unit 111c of the control unit 111 to store the mixture viscosity μT1, the engine speed Ne, the mixture temperature T1, the mixture pressure P1 stored in the storage unit 111a of the control unit 111. Based on the charging efficiency η _c and the stroke volume V _s , the viscosity-corrected actual mixed gas flow rate QmixR shown in the above-described equation 2 is calculated. The ECU 110 stores the viscosity corrected actual mixture flow rate QmixR calculated by the mixture flow rate control unit 111c of the control unit 111 in the storage unit 111a of the control unit 111, and then shifts the control step to step S250.

In step S250, the ECU 110 determines whether the viscosity correction actual mixture flow rate QmixR stored in the storage unit 111a of the control unit 111 is equal to the mixture flow rate command value QmixO by the mixture flow rate control unit 111c of the control unit 111. judge.
As a result, when it is determined that the viscosity corrected actual mixture flow rate QmixR is equal to the mixture flow rate command value QmixO, the ECU 110 ends the mixture flow rate control step B, and the control stage is repeatedly transferred to step S100 (see FIG. 2). To do.
If it is determined that the viscosity-corrected actual mixture flow rate QmixR is not equal to the mixture flow rate command value QmixO, the ECU 110 shifts the control step to step S260.

In step S260, the ECU 110 determines whether or not the viscosity corrected actual mixture flow rate QmixR stored in the storage unit 111a of the control unit 111 is larger than the mixture flow rate command value QmixO by the mixture flow rate control unit 111c of the control unit 111. judge.
As a result, when it is determined that the viscosity corrected actual mixture flow rate QmixR is larger than the mixture flow rate command value QmixO, that is, the ratio (air-fuel ratio) between the flow rate of the fuel gas constituting the mixture and the flow rate of the outside air (air) is When it is too small (lean side) with respect to the appropriate value and the air-fuel mixture flow rate is increasing in order to maintain the necessary fuel gas flow rate, the ECU 110 shifts the control stage to step S270.
Further, when it is determined that the viscosity-corrected actual mixture flow rate QmixR is smaller than the mixture flow rate command value QmixO, that is, the ratio (air-fuel ratio) between the flow rate of the fuel gas constituting the mixture and the flow rate of the outside air (air) is appropriate. If the value is excessive (rich side) with respect to the value and the air-fuel mixture flow rate is decreasing in order to maintain the required fuel gas flow rate, the ECU 110 shifts the control step to step S280.

  In step S270, the ECU 110 controls the mixture flow rate control unit 111c of the control unit 111 based on the deviation between the viscosity corrected actual mixture flow rate QmixR and the mixture flow rate command value QmixO stored in the storage unit 111a of the control unit 111. Then, the opening correction amount FvH of the fuel gas control valve 42 is calculated. The ECU 110 controls the air-fuel mixture flow rate control step B after the air-fuel flow rate control unit 111c of the control unit 111 controls the opening degree of the fuel gas control valve 42 to be increased by the opening correction amount FvH via the output unit 113. Is finished, and the control stage is repeatedly transferred to step S100 (see FIG. 2).

  In step S280, the ECU 110 controls the mixture flow rate control unit 111c of the control unit 111 based on the deviation between the viscosity corrected actual mixture flow rate QmixR and the mixture flow rate command value QmixO stored in the storage unit 111a of the control unit 111. Then, the opening correction amount FvH of the fuel gas control valve 42 is calculated. The ECU 110 controls the air-fuel mixture flow rate control step B after the air-fuel mixture flow rate control unit 111c of the control unit 111 controls the output of the fuel gas control valve 42 to be decreased by the opening correction amount FvH via the output unit 113. Is finished, and the control stage is repeatedly transferred to step S100 (see FIG. 2).

As described above, the gas engine control apparatus 100 according to the present embodiment, as shown in FIG. 5, actually supplied by being mixed airflow (air-fuel mixture flow rate measured value) and the mixture viscosity correction viscosity mu _T1 Considering The error with the actual mixture flow rate QmixR can be made smaller than the error between the actual mixture flow rate measured value and the actual mixture flow rate Qmix (without correction). As a result, as shown in FIG. 6, even if the O ₂ concentration contained in the outside air fluctuates due to fluctuations in the temperature of the outside air at each net average effective pressure (each engine output), the amount of fuel gas and Since the air-fuel mixture flow rate is changed, the NOx concentration discharged from the gas engine 1 does not fluctuate. That is, the NOx concentration discharged from the gas engine 1 is not affected by the temperature of the outside air.

As described above, the gas engine control apparatus 100 according to the present embodiment is the temperature detection sensor 130 that is a mixture temperature detection means that detects the mixture temperature T1, and the mixture pressure detection means that detects the mixture pressure P1. From the pressure detection sensor 140, the engine speed detection sensor 120 that is an engine speed detection means for detecting the engine speed Ne, and the load Ld that is input to the generator 50 that is a load device driven by the gas engine 1, the engine An engine speed control unit 111b, which is an engine speed control means that determines an engine speed command value NeO and controls the opening of the throttle valve 23 based on a deviation between the engine speed Ne and the engine speed command value NeO; The mixture flow rate command value QmixO is determined from the load Ld and the engine speed command value NeO, and the mixture temperature T1 and 0 based on mixture viscosity mu ₀ at ℃ calculates the mixture viscosity mu _T1 shown in the following equation (1), gas mixture temperature T1, the air-fuel mixture viscosity mu _T1, the air-fuel mixture pressure P1, the engine speed Ne, the charging efficiency η _The viscosity corrected actual mixture flow rate QmixR shown in the following equation 2 is calculated based on _c and the stroke volume V _s , and the fuel gas control is performed based on the deviation between the mixture flow rate command value QmixO and the viscosity corrected actual mixture flow rate QmixR. And an air-fuel mixture flow rate control unit 111c, which is an air-fuel mixture flow rate control means for controlling the opening degree of the valve 42.

By comprising in this way, the difference | error of the gas mixture flow volume which the gas engine control apparatus 100 calculates and the gas mixture flow volume actually supplied can be made small. As a result, it is possible to maintain the air-fuel mixture in the appropriate air-fuel ratio, the O ₂ concentration of O ₂ concentration in the ambient air by variations in the temperature of the outside air contained in the mixed gas be varied does not change. That is, the NOx concentration discharged from the gas engine 1 is not affected by the temperature of the outside air.

DESCRIPTION OF SYMBOLS 1 Gas engine 23 Throttle valve 42 Fuel gas control valve 50 Generator 120 Engine rotation speed detection sensor 130 Mixture temperature detection sensor 140 Mixture pressure detection sensor μ ₀ Mixture viscosity at 0 ° C. μ _T Fluid viscosity Ne Engine rotation speed T1 Mixing Air temperature P1 Mixture pressure η _c Charging efficiency V _s Stroke volume Ld Load NeO Engine speed command value QmixO Mixture flow rate command value QmixR Viscosity corrected actual mixture flow rate

Claims (1)

A mixture temperature detecting means for detecting the mixture temperature T1, and
A mixture pressure detecting means for detecting the mixture pressure P1, and
Engine speed detecting means for detecting the engine speed Ne;
An engine speed which determines an engine speed command value from a load applied to a load device driven by the engine, and controls the opening of the throttle valve based on a deviation between the engine speed Ne and the engine speed command value Number control means;
An air-fuel mixture flow rate command value is determined from the load and the engine speed command value, and based on the air-fuel mixture temperature T1 and the air-fuel mixture viscosity μ ₀ at 0 ° C., an air-fuel mixture viscosity μ _T1 shown in the following _{equation 1} is obtained. Based on the calculated mixture temperature T1, the mixture viscosity μ _T1 , the mixture pressure P1, the engine speed Ne, the charging efficiency η _c , and the stroke volume V _s , the viscosity correction actuality shown in the following equation 2 is obtained. An air-fuel mixture flow rate control means for calculating an air-fuel mixture flow rate QmixR and controlling the opening of the fuel gas control valve based on a deviation between the air-fuel mixture flow rate command value and the viscosity-corrected actual air-fuel mixture flow rate QmixR;
A gas engine control device comprising:

Images