Control device, engine system, control method and program

Abstract

To provide a control device that has a function of compensating for delay from when a mixed fuel is produced until the mixed fuel reaches a combustion chamber of an engine when a mixture ratio of the mixed fuel in which multiple fuels are mixed is used for control.SOLUTION: A control device controls an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe based on a mixing ratio of the plurality of gases, and includes: means for calculating the mixing ratio at the mixing point by compensating for delay from the mixing point until the mixed fuel reaches a combustion chamber of the engine; and means for controlling the engine based on the mixing ratio after compensation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a control device, an engine system, a control method, and a program. [Background technology]

[0002] As part of the CO2 reduction, a system has been proposed that uses a gas engine to drive and generate electricity using a fuel that is a mixture of hydrogen and fuel gas such as city gas (natural gas). In a gas engine that mixes and switches between multiple fuels, it is necessary to change the air-fuel ratio and ignition timing depending on the fuel properties and calories, and to correct the density and calorie information of the fuel used for control. When using a fuel that is a mixture of multiple fuels, the mixture ratio is controlled to a desired value by providing a valve at the position where the fuel is mixed (called the mixing point), and the value of the mixture ratio is sometimes used to control the engine. In such an engine, it is necessary to change the mixture ratio and switch between the presence and absence of mixing, but if the distance from the mixing point to the combustion chamber in the engine cylinder is long, a situation occurs in which the mixture ratio at the mixing point differs from the actual mixture ratio in the combustion chamber. For example, in a situation in which the fuel mixture ratio must be switched instantly due to a sudden change in load or detection of an abnormality in the engine, the difference between the mixture ratio at the fuel mixing point and the combustion chamber becomes large.

[0003] Patent Document 1 discloses a control that detects an abnormal state of combustion by the cylinder pressure of a hydrogen-mixed engine and eliminates the abnormal state by appropriately controlling the hydrogen mixture ratio. However, Patent Document 1 does not assume a premixing method in which there is a distance between the mixing point and the combustion chamber, and does not disclose a mechanism for compensating for the difference between the mixture ratio at the mixing point and the actual mixture ratio in the combustion chamber, in other words, the time (delay) until the mixed fuel controlled to the desired mixture ratio at the mixing point reaches the combustion chamber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 259771 Summary of the Invention [Problem to be solved by the invention]

[0005] In an engine that uses a mixed fuel in which a plurality of fuels are mixed, there is a demand for control that takes into consideration the delay in the arrival of the fuel mixed at a desired mixture ratio from the mixing point to the combustion chamber.

[0006] The present disclosure provides a control device, an engine system, a control method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0007] The control device disclosed herein is a control device that controls an engine to which mixed fuel produced by mixing multiple gases at a mixing point is supplied through a pipe, based on a mixing ratio of the multiple gases, and includes a means for calculating the mixing ratio at the mixing point by compensating for a delay until the mixed fuel reaches a combustion chamber of the engine from the mixing point, and a means for controlling the engine based on the mixing ratio after compensation.

[0008] The engine system of the present disclosure includes an engine, a fuel mixing device that mixes a plurality of gases at a mixing point, piping that connects the mixing point and the engine, and the above-mentioned control device.

[0009] The control method disclosed herein is a control method for controlling an engine to which mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe, based on a mixing ratio of the plurality of gases, and includes a step of calculating a mixing ratio at the mixing point by compensating for a delay in the mixed fuel reaching a combustion chamber of the engine from the mixing point, and a step of controlling the engine based on the mixing ratio after the compensation.

[0010] The program disclosed herein causes a computer of a control device that controls an engine to which mixed fuel produced by mixing multiple gases at a mixing point is supplied through a pipe based on a mixing ratio of the multiple gases to execute the following steps: calculating a mixing ratio at the mixing point by compensating for a delay until the mixed fuel reaches a combustion chamber of the engine from the mixing point; and controlling the engine based on the mixing ratio after compensation. Effect of the Invention

[0011] According to the above-described control device, engine system, control method, and program, the delay between when the mixed fuel is produced and when it is supplied to the combustion chamber can be compensated for, thereby enabling the engine to be operated stably. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing an example of an engine system according to an embodiment; [Diagram 2] 11A and 11B are diagrams illustrating a delay compensation process according to an embodiment. [Diagram 3] 11A to 11C are diagrams illustrating examples of setting dead time and the like according to a flow rate range according to the embodiment. [Figure 4] 4 is a flowchart illustrating an example of engine control according to the embodiment. [Diagram 5] 10 is a flowchart illustrating an example of mixing / non-mixing switching control according to the embodiment. [Figure 6] FIG. 2 is a schematic diagram illustrating an example of a hardware configuration of a controller according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <Embodiment> Hereinafter, the configuration and control of an engine system 1 according to the present disclosure will be described with reference to FIGS. FIG. 1 is a block diagram showing an example of an engine system according to an embodiment. The engine system 1 includes a hydrogen mixing device 2, an engine 3, a generator 4, a circuit breaker 5, a hydrogen mixing device controller 20 which is a control device for the hydrogen mixing device 2, an engine controller 30 which is a control device for the engine 3, and a generator controller 40 which is a control device for the generator 4, etc.

[0014] The hydrogen mixing device 2 generates a mixed fuel by mixing hydrogen with a fuel gas such as city gas (natural gas), and supplies the generated mixed fuel to the engine 3. The ratio of hydrogen in the mixed fuel is called the mixing ratio. The mixing ratio is controlled between 0 and several tens of percent. For example, when the engine 3 starts and reaches a stable operating state, the mixing ratio is gradually increased from 0%, and when it reaches a predetermined value, the mixing ratio is maintained. Then, when a sudden change in load or an abnormality in the engine 3 is detected, the mixing ratio is immediately reduced to 0%. In a situation where the mixing ratio is gradually increased to a predetermined value, the change in the mixing ratio per unit time is small, so the delay until the mixed fuel reaches the combustion chamber is not a big problem. However, in a situation where the mixing ratio is changed significantly in a short time (for example, when the mixing ratio is immediately reduced to 0%), the mixing ratio at the mixing point and the combustion chamber is likely to deviate, and if control is performed using the control value of the mixing ratio (the mixing ratio at the mixing point), it may result in erroneous control based on a mixing ratio that is different from the actual one. Therefore, in this embodiment, the actual mixture ratio in the combustion chamber is estimated from the mixture ratio of the mixed fuel produced by the hydrogen mixer 2, and the estimated value is used for controlling the engine 3.

[0015] The hydrogen mixing device 2 includes a pipe 2A through which fuel gas (hereinafter referred to as city gas) is supplied, a pipe 2B through which hydrogen gas is supplied, and a pipe 2C through which the mixed fuel is supplied. The pipes 2A and 2B are connected to the pipe 2C at a mixing point 2D. A flow control valve 2a is provided in the pipe 2A, and a flow control valve 2b is provided in the pipe 2B. Pressure gauges (not shown) are provided in the pipes 2A and 2B, and the hydrogen mixing device controller 20 controls the opening of the flow control valves 2a and 2b based on the flow rates of hydrogen gas and city gas calculated from the measured pressure values ​​of the pipes 2A and 2B, thereby controlling the mixing ratio at the mixing point 2D to a desired value. The value of the mixing ratio may be set in the hydrogen mixing device controller 20, or may be instructed from the engine controller 30 or the generator controller 40.

[0016] The engine 3 is a gas engine that uses city gas as fuel, and generates a mixture by mixing the mixed fuel supplied from the hydrogen mixing device 2 with intake air (air) supplied through a pipe 3a, and rotates and drives the output shaft 3b by burning the generated mixture. The engine controller 30 mainly performs combustion control and air-fuel ratio control to operate the engine 3. In the combustion control, feedback control is performed to keep the rotation speed and load of the engine 3 constant. In the air-fuel ratio control, feedback control is performed so that the air-fuel ratio becomes a target value by controlling a throttle valve (not shown) or the like provided in the pipe system of the mixture flowing into the combustion chamber in order to keep the air-fuel ratio in the combustion chamber of the engine 3 constant. The configuration of the engine 3, the combustion control, and the air-fuel ratio control are known, so detailed explanations are omitted. The function of the engine controller 30 related to the delay compensation process of this embodiment will be described later.

[0017] The generator 4 is connected to the engine 3 via the output shaft 3b, and generates electricity using the rotational driving force transmitted from the output shaft 3b. The generator 4 is connected to an electric power system (not shown) via a circuit breaker 5. The electric power generated by the generator 4 is supplied to a load 6 through the electric power system by opening and closing the circuit breaker 5. A generator controller 40 controls the generator 4, the circuit breaker 5, and auxiliary equipment (not shown), etc.

[0018] The hydrogen mixing device controller 20, the engine controller 30, and the generator controller 40 are connected to each other via a network such as a LAN and signal lines. The control state of the engine system 1 is transmitted and received via the network, and fault information (fault contact signal) and the like are transmitted and received via signal lines, and these pieces of information are shared among the three controllers 20, 30, and 40. For example, the hydrogen mixing device controller 20 transmits the hydrogen mixing ratio at the mixing point 2D to the engine controller 30. The engine controller 30 transmits to the hydrogen mixing device controller 20 and the generator controller 40 a determination result as to whether or not mixed combustion control (operation of the engine 3 using a mixed fuel mixed with hydrogen) is possible. The hydrogen mixing device controller 20 or the generator controller 40 transmits an instruction signal to start mixed combustion to the engine controller 30. The generator controller 40 also detects the magnitude of the load 6 and transmits a load signal indicating the magnitude of the load 6 to the engine controller 30.

[0019] The engine controller 30 includes a signal acquisition unit 31 , a multi-fuel combustion permission determination unit 32 , and a control unit 33 . The signal acquisition unit 31 acquires a load signal indicating the magnitude of the load 6 from the generator controller 40. The signal acquisition unit 31 makes decisions such as load shedding and load application based on the load signal. The signal acquisition unit 31 also acquires the mixing ratio at the mixing point 2D from the hydrogen mixer controller 20. The signal acquisition unit 31 acquires an instruction signal to start mixed combustion control from the hydrogen mixer controller 20 or the generator controller 40.

[0020] The mixed combustion possibility determination unit 32 determines whether mixed combustion control, that is, operation of the engine 3 with mixed fuel obtained by mixing hydrogen with fuel gas, is possible. For example, the mixed combustion possibility determination unit 32 determines that mixed combustion control is possible when the magnitude of the load 6 is equal to or greater than a predetermined reference value or when the engine 3 is in a stable operating state. In addition, for example, the mixed combustion possibility determination unit 32 determines that mixed combustion control is impossible when it detects a sudden change in the load or an abnormal state. The mixed combustion possibility determination unit 32 transmits the determination result to the hydrogen mixing device controller 20 and the generator controller 40. When it is determined that mixed combustion control is possible, for example, an operator or the like instructs the hydrogen mixing device controller 20 or the generator controller 40 to start mixed combustion control, and based on this instruction, the hydrogen mixing device controller 20 starts generating mixed fuel. When it is determined that mixed combustion control is impossible, the hydrogen mixing device controller 20 supplies city gas with a mixture ratio of 0% to the engine 3 by fully closing the flow control valve 2b and fully opening the flow control valve 2a.

[0021] The control unit 33 controls the engine 3. For example, the control unit 33 controls the air-fuel ratio by targeting an air-fuel ratio according to the mixture ratio of hydrogen. For example, the control unit 33 has a table in which the mixture ratio corresponds to the air-fuel ratio, and calculates the air-fuel ratio according to the mixture ratio based on this table and the mixture ratio acquired from the hydrogen mixing device controller 20, and performs feedback control so that the air-fuel ratio in the combustion chamber becomes the calculated air-fuel ratio. At this time, the control unit 33 compensates for the delay until the mixed fuel controlled to the desired mixture ratio reaches the combustion chamber of the engine 3 from the mixing point 2D, and calculates the target air-fuel ratio based on the compensated mixture ratio. FIG. 2 shows an example of the delay compensation process in this embodiment. The control unit 33 acquires the mixture ratio r(t) at the mixture point 2D at time t from the hydrogen mixing device controller 20 through the signal acquisition unit 31. The control unit 33 calculates the target air-fuel ratio based on the transfer function G(s)=e shown in the block diagram of FIG. 2. -LsThe mixture ratio rc(t) after delay compensation is calculated using / Tb·s+1. Here, L is the dead time and Tb is the time constant of the first-order lag. The dead time L can be expressed as L=V / Q. The time constant Tb of the first-order lag can be expressed as Tb=1 / (PV / RT·Q·σ). V is the volume (m 3 ), Q is the flow rate of the mixed fuel (m 3 / sec), P is the pressure of the mixed fuel (Pa), R is the gas constant, and σ is the density of the mixed fuel (kg / m 3 ), T is the temperature of the mixed fuel (℃), and s is the Laplace operator. For example, the above transfer function G(s) can be used to determine the delay with which the mixed fuel with the mixing ratio r(t0) is supplied to the combustion chamber from the mixing ratio r(t0) at the mixing point 2D at time t0. The mixing ratio of the mixed fuel that reaches the combustion chamber at each time can be estimated by constantly calculating the mixing ratio rc(t) after delay compensation from the mixing ratio r(t) at each time using the transfer function G(s). This allows the control unit 33 to control the engine 3 using the mixing ratio rc(t0) of the mixed fuel that was supplied to the pipe 2C from the hydrogen mixing device 2 a little earlier and reaches the combustion chamber at time t0, rather than the mixing ratio r(t0) of the mixed fuel generated by the hydrogen mixing device 2 at time t0.

[0022] The delay due to the piping from the mixing point 2D to the cylinder of the engine 3 is considered to be only the dead time L (i.e., Tb=0), and the time constant Tb of the first-order delay is used for adjustment. When the first-order delay time constant Tb is used, the dead time L is also taken into consideration for adjustment so that the delay does not become too large. The control unit 33 may obtain measured values ​​of the flow rate Q of the mixed fuel, the pressure P of the mixed fuel, the density σ of the mixed fuel, the temperature T of the mixed fuel, etc., calculate the first-order delay time constant Tb and the dead time L each time, and calculate the mixture ratio after delay compensation using the transfer function G(s). Alternatively, values ​​of the flow rate Q and density σ in the flow rate range of the mixed fuel that is frequently used or in the flow rate range when the mixture ratio is switched may be obtained by measuring or calculating, and the first-order delay time constant Tb and the dead time L calculated in advance using these values ​​may be set in the control unit 33, and the mixture ratio after delay compensation may be calculated using Tb and L in the corresponding flow rate range according to the operating state and load 6 of the engine 3. 3 shows an example of the time constant Tb of the first-order lag and the dead time L according to the flow rate range. For example, the control unit 33 may have a table as shown in FIG. 3, and may determine which flow rate range the flow rate of the mixed fuel belongs to according to the operating state of the engine 3 and the magnitude of the load 6 at each time (for example, a table that defines the correspondence between the operating state of the engine 3 and the flow rate range is prepared), obtain the time constant Tb of the first-order lag and the dead time L according to the flow rate of the mixed fuel by referring to the table in FIG. 3, and calculate the mixture ratio after the delay compensation by the transfer function G(s) described above. Alternatively, a table that defines the values ​​of the time constant Tb of the first-order lag and the dead time L for each operating state of the engine 3 and the magnitude of the load 6 may be set in the control unit 33, and the mixture ratio after the delay compensation may be calculated based on this table and the operating state of the engine 3 at each time.

[0023] (Engine control operation taking into account the delay in supply of mixture ratio) Next, with reference to FIG. 4, a process for engine control that takes into account a supply delay in the mixture ratio according to this embodiment will be described. FIG. 4 is a flowchart showing an example of engine control according to the embodiment. The hydrogen mixing device controller 20 controls the flow control valves 2a and 2b so that the hydrogen mixing ratio at the mixing point 2D becomes a desired value. The hydrogen mixing device controller 20 transmits the controlled value of the mixing ratio to the engine controller 30. In the engine controller 30, the signal acquisition unit 31 acquires the value of the mixing ratio (step S1). The signal acquisition unit 31 outputs the acquired value of the mixing ratio to the control unit 33. The control unit 33 calculates the mixing ratio after the delay compensation process using the transfer function (G(s)) illustrated in FIG. 2 (step S2). The control unit 33 stores the calculated mixing ratio after the delay compensation process. By constantly executing steps S1 to S2 while the engine 3 is in operation, the control unit 33 stores the time-series mixing ratio after the delay compensation process. Next, the control unit 33 controls the engine 3 based on the mixing ratio in the combustion chamber, not on the mixing point 2D acquired from the hydrogen mixing device controller 20 (step S3). The control unit 33 determines the mixture ratio of the mixed fuel in the combustion chamber at the current time from the mixture ratios after the delay compensation process in the time series calculated in the process of step S2, and performs control according to the determined mixture ratio.

[0024] (effect) In conventional control, the time it takes for the mixed fuel to reach the cylinder from the mixing point 2D was not taken into consideration. Therefore, in a situation where the mixture ratio suddenly changes, a discrepancy occurs between the mixture ratio at the mixing point 2D and the mixture ratio in the combustion chamber, and if the engine is controlled using the control value of the mixture ratio (the mixture ratio at the mixing point 2D), the operating state of the engine 3 may become unstable. In contrast, according to the present embodiment, the arrival delay of the mixed fuel is taken into consideration and control is performed according to the actual mixture ratio in the combustion chamber, so that the engine 3 can be operated stably.

[0025] (Switching of mixed combustion control) Next, we will explain how to change the mixture ratio and switch between mixing and not mixing. In order to operate the engine 3 stably, the multi-fuel feasibility determination unit 32 determines that multi-fuel control is possible only when stable operation is possible even with mixed fuel, and selects operation with city gas only if stable operation is not possible.

[0026] FIG. 5 is a flowchart illustrating an example of mixing / non-mixing switching control according to the embodiment. The multi-firing feasibility determination unit 32 determines whether multi-firing control is possible based on the state of the load 6 or the engine 3, and the presence or absence of an abnormality (step S11). The multi-firing feasibility determination unit 32 determines whether to perform multi-firing control or to stop mixing based on whether stable operation is possible. For example, if stable operation is possible even if the mixing ratio is increased, the mixing ratio is increased so that CO2 emissions can be reduced (multi-firing control is possible), but if stable operation is difficult with multi-firing control, it determines to stop mixing. For example, the multi-firing feasibility determination unit 32 determines whether to change the mixing ratio or to stop mixing based on the following criteria (1) to (4).

[0027] (1) Judgment based on load To ensure stable combustion, for example, the multi-firing feasibility determination unit 32 determines that multi-firing control should be performed when the magnitude of the load 6 acquired by the signal acquisition unit 31 is equal to or greater than a certain value. For example, the multi-firing feasibility determination unit 32 may determine that multi-firing control is possible when the magnitude of the load 6 is equal to or greater than a predetermined load, and may determine that multi-firing control should be stopped when the magnitude of the load 6 is less than the predetermined load. Alternatively, the multi-firing feasibility determination unit 32 may have map information that associates the magnitude of the load with the fuel mixture ratio, and may determine whether or not to perform multi-firing control or whether or not to change the fuel mixture ratio based on the magnitude of the load 6 and the map information.

[0028] (2) Judgment based on other engine conditions The multi-fuel compatibility determination unit 32 may determine that the engine 3 has been warmed up if the temperatures of the lubricating oil and cooling water are equal to or higher than a predetermined threshold, and may determine that the engine 3 is in a stable operating state if the engine 3 has been warmed up, and may determine that the fuels should be mixed (multi-fuel control is possible), and may determine that the fuel mixing should be stopped if the engine 3 is not in that state. Also, for example, the multi-fuel compatibility determination unit 32 may determine that the operating state is stable when a certain period of time has passed since the start of the engine 3, and may determine that multi-fuel control is possible.

[0029] (3) Judgment based on abnormal conditions The mixed fuel combustion possibility determination unit 32 immediately determines to stop the mixed fuel combustion when an abnormality in the engine 3 is detected.

[0030] (4) Load shedding and loading When the signal acquisition unit 31 detects a load dump, the multi-fuel combustion feasibility determination unit 32 determines that mixing should be immediately stopped. Load dump is detected by detecting an "open" at the circuit breaker 5 or a sudden drop in load. When the signal acquisition unit 31 detects a load connection, the multi-fuel combustion feasibility determination unit 32 determines that mixing should be immediately stopped. Load connection is detected by detecting a "close" at the circuit breaker 5 or a sudden increase in load.

[0031] When the mixed combustion possibility determination unit 32 determines that mixed combustion control is possible based on the above determination criteria (1) to (4) (step S11; Yes), the mixed combustion possibility determination unit 32 notifies the hydrogen mixing device controller 20 that mixed combustion control is possible (step S12). When this signal is transmitted and the start of mixed combustion control is instructed by the operator who confirmed that mixed combustion control is possible, the hydrogen mixing device controller 20 increases the hydrogen mixing ratio to a predetermined mixing ratio at a predetermined speed, for example. In addition, when the mixing ratio is continuously changed based on map information of the load and the mixing ratio, for example, the mixed combustion possibility determination unit 32 may determine the mixing ratio according to the load based on the magnitude of the load 6 and the map information, and notify the hydrogen mixing device controller 20 of the determined mixing ratio, and the hydrogen mixing device controller 20 may control the flow control valves 2a and 2b to change the hydrogen mixing ratio to the determined mixing ratio at a predetermined speed. When the hydrogen mixing device controller 20 changes the mixing ratio, it notifies the engine controller 30 of the changed mixing ratio.

[0032] If the mixed combustion possibility determination unit 32 determines that mixed combustion control is not possible (step S11; No), the mixed combustion possibility determination unit 32 notifies the hydrogen mixing device controller 20 that mixed combustion control is not possible (step S13). For example, if load shedding is detected during mixed combustion control, the mixed combustion possibility determination unit 32 sends a signal to instruct the mixing to be stopped. The hydrogen mixing device controller 20 immediately reduces the hydrogen mixing ratio to 0%. When the hydrogen mixing device controller 20 changes the mixing ratio, it notifies the engine controller 30 of the changed mixing ratio. If fuel mixing was not performed originally, the hydrogen mixing device controller 20 does not change the mixing ratio and supplies only city gas to the engine 3.

[0033] In the engine controller 30, the signal acquisition unit 31 acquires the mixing ratio from the hydrogen mixing device controller 20, and the control unit 33 controls the engine 3 (step S14). The process of step S14 is as described with reference to FIG. 4. The control unit 33 calculates the mixing ratio taking into account the delay, and controls the engine 3 using the calculated mixing ratio after the delay compensation. At this time, the control unit 33 may calculate the mixing ratio after the delay compensation process using a first-order delay time constant Tb and a dead time L according to the flow rate range. For example, the control unit 33 has a table in which the first-order delay time constant Tb and the dead time L are set for each flow rate range illustrated in FIG. 3, and determines L and Tb according to this table and the flow rate Q of the mixed fuel. Then, the control unit 33 calculates the mixing ratio after the delay compensation process using the determined L and TB and the transfer function of FIG. 2. Then, the control unit 33 controls the engine 3 using the mixing ratio after the delay compensation process.

[0034] Next, the control unit 33 determines whether or not to terminate the operation of the engine 3 (step S15). For example, when a command to stop the engine 3 is input by the user, the control unit 33 determines to terminate the operation of the engine 3 (step S15; Yes), and terminates the processing of the flowchart in Fig. 5. If the operation is not to be terminated (step S15; No), the processing from step S11 is repeatedly executed.

[0035] (effect) 5, the mixture ratio is changed depending on the operating state of the engine 3, whether there is an abnormality, whether there is a sudden load change, etc., thereby enabling stable operation without stopping the engine 3. In addition, since the engine 3 is controlled using a mixture ratio that takes into account the arrival delay of the mixed fuel, the mixture ratio in the combustion chamber can be used for control even in situations where the mixture ratio at the mixing point D2 and the mixture ratio in the combustion chamber are likely to deviate from each other, such as when mixing is stopped immediately, and therefore stable operation of the engine 3 is possible.

[0036] In the above embodiment, city gas and hydrogen gas are mixed, but the types of gases to be mixed are not limited to these. In addition, three or more types of gases may be mixed.

[0037] FIG. 6 is a schematic block diagram showing a hardware configuration of a controller according to an embodiment. A computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The above-mentioned hydrogen mixing device controller 20, the engine controller 30, and the generator controller 40 are implemented in the computer 90. The operations of the above-mentioned processing units are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, expands it in the main memory 92, and executes the above-mentioned processing according to the program. The processor 91 also secures a storage area corresponding to each of the above-mentioned storage units in the main memory 92 according to the program. Examples of the processor 91 include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), and a microprocessor.

[0038] The program may be for realizing a part of the functions to be performed by the computer 90. For example, the program may be for realizing the functions by combining with other programs already stored in the storage or by combining with other programs implemented in other devices. In another embodiment, the computer 90 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to the above configuration or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions to be realized by the processor 91 may be realized by the integrated circuit. Such an integrated circuit is also included in an example of a processor.

[0039] Examples of the storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a semiconductor memory. The storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via an interface 94 or a communication line. In addition, when the program is distributed to the computer 90 via a communication line, the computer 90 that receives the program may load the program into the main memory 92 and execute the above-mentioned process. In at least one embodiment, the storage 93 is a non-transitory tangible storage medium.

[0040] The program may be for realizing part of the above-mentioned functions. Furthermore, the program may be a so-called differential file (differential program) that realizes the above-mentioned functions in combination with another program already stored in the storage 93.

[0041] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and gist of the invention.

[0042] <Additional Notes> The control device, engine system, control method, and program described in each embodiment can be understood, for example, as follows.

[0043] (1) A control device according to a first aspect is a control device that controls an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe, based on a mixing ratio of the plurality of gases, and includes a means (control unit 33, step S2) for calculating the mixing ratio at the mixing point by compensating for a delay in the mixed fuel reaching the combustion chamber of the engine from the mixing point, and a means (control unit 33, step S3) for controlling the engine based on the mixing ratio after the compensation. This compensates for the delay between when the fuel mixture is produced and when it is supplied to the combustion chamber, enabling the engine to operate stably.

[0044] (2) A control device according to a second aspect is the control device of (1), wherein the means for calculating the mixing ratio is expressed by a transfer function G(s)=e where L is a dead time, Tb is a first-order time constant, L=V / Q, Tb=1 / (PV / RT·Q·σ), V is a volume of the piping from the mixing point to the cylinder of the engine, Q is a flow rate of the mixed fuel, P is a pressure of the mixed fuel, R is a gas constant, σ is a density of the mixed fuel, T is a temperature of the mixed fuel, and s is a Laplace operator. -Ls The mixing ratio at the mixing point is input to / Tb·s+1 to calculate the mixing ratio with the delay compensated for. This makes it possible to compensate for the delay in the mixing rate.

[0045] (3) A control device according to a third aspect is the control device of (2), wherein the means for calculating the mixing ratio has a table that corresponds the flow rate of the mixed fuel to the L and the Tb, and determines the L and the Tb using the flow rate of the mixed fuel flowing through the piping and the table, and calculates the mixing ratio with the delay compensated for according to the flow rate of the mixed fuel flowing through the piping using the determined L, Tb and the transfer function G(s). This can reduce the calculation load when calculating the delay-compensated mixture ratio.

[0046] (4) A control device according to a fourth aspect is a control device according to any one of (1) to (3), further comprising a means for determining whether or not to change the mixing ratio (multi-fuel combustion feasibility determination unit 32, step S11), and the determination means determines that, when the magnitude of the engine load is equal to or greater than a predetermined threshold, the multiple gases are mixed, and, when the magnitude of the engine load is less than the threshold, the multiple gases are not mixed. By allowing the mixture only when the operating load is above a certain level, stable engine operation can be achieved.

[0047] (5) A control device according to a fifth aspect is a control device of (1) to (4), further comprising a means for determining a change in the mixing ratio, the means for determining whether to mix the multiple gases when the engine is in a stable operating state, and whether to not mix the multiple gases when the engine is not in a stable operating state. By permitting the mixture only when the engine operating condition is stable, stable engine operation can be achieved.

[0048] (6) A control device according to a sixth aspect is a control device of (1) to (5), further comprising a means for determining a change in the mixing ratio, and when an abnormality in the engine is detected, the means for determining determines to stop mixing the multiple gases. When an engine abnormality is detected, mixing is stopped immediately, thereby realizing stable engine operation.

[0049] (7) A control device according to a seventh aspect is a control device of (1) to (6), further comprising a means for determining a change in the mixing ratio, and when a load interruption or load introduction is detected, the means for determining determines to stop mixing the multiple gases. By stopping the mixing when the load suddenly changes, stable engine operation can be achieved.

[0050] (8) An engine system according to an eighth aspect includes an engine, a fuel mixing device that mixes multiple gases at a mixing point, piping that connects the mixing point to the engine, and a control device described in any one of (1) to (7).

[0051] (9) A control method according to a ninth aspect is a control method for controlling an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe, based on a mixing ratio of the plurality of gases, and includes a step of calculating the mixing ratio at the mixing point by compensating for a delay in the mixed fuel reaching a combustion chamber of the engine from the mixing point, and a step of controlling the engine based on the mixing ratio after the compensation.

[0052] (10) A program according to a tenth aspect causes a computer of a control device that controls an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe based on a mixing ratio of the plurality of gases to execute the steps of: calculating a mixing ratio at the mixing point by compensating for a delay in the mixed fuel reaching a combustion chamber of the engine from the mixing point; and controlling the engine based on the mixing ratio after the compensation. [Explanation of symbols]

[0053] 1. Engine System 2. Hydrogen mixing device 3. Engine 4. Generator 5. Circuit breaker 6. Load 20...Hydrogen mixing device controller 30 Engine controller 31 Signal acquisition unit 32...Co-firing possibility determination section 33 Control section 40 Generator controller 90. Computer 91. Processor 92 Main memory 93. Storage 94 Interface

Claims

1. A control device for controlling an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe, based on a mixing ratio of the plurality of gases, a means for calculating the mixing ratio by compensating for a delay in the mixed fuel reaching a combustion chamber of the engine from the mixing point, with respect to the mixing ratio at the mixing point; means for controlling the engine based on the compensated mixture ratio; A control device comprising:

2. The means for calculating the mixing ratio is When L is a dead time, Tb is a first-order time constant, L=V / Q, Tb=1 / (PV / RT·Q·σ), V is the volume of the pipe from the mixing point to the engine cylinder, Q is the flow rate of the mixed fuel, P is the pressure of the mixed fuel, R is a gas constant, σ is the density of the mixed fuel, T is the temperature of the mixed fuel, and s is a Laplace operator, the transfer function G(s)=e －Lｓ The mixing ratio at the mixing point is input to / Tb·s+1 to calculate the mixing ratio with the delay compensated for. The control device according to claim 1 .

3. The means for calculating the mixing ratio is a table in which the flow rate of the mixed fuel is associated with the L and the Tb; determining L and Tb using a flow rate of the mixed fuel flowing through the piping and the table, and calculating the mixing ratio in which the delay is compensated for, according to the flow rate of the mixed fuel flowing through the piping, using the determined L and Tb and the transfer function G(s); The control device according to claim 2.

4. The mixing ratio change determining means further includes: The determining means determines to mix the plurality of gases when the magnitude of the load on the engine is equal to or greater than a predetermined threshold, and determines not to mix the plurality of gases when the magnitude of the load on the engine is less than the threshold. The control device according to claim 1 or 2.

5. The mixing ratio change determining means further includes: The determining means determines to mix the plurality of gases when the engine is in a stable operating state, and not to mix the plurality of gases when the engine is not in a stable operating state. The control device according to claim 1 or 2.

6. The mixing ratio change determining means further includes: The determining means determines to stop mixing the plurality of gases when an abnormality in the engine is detected. The control device according to claim 1 or 2.

7. The mixing ratio change determining means further includes: The determining means determines to stop mixing the plurality of gases when a load rejection or a load introduction is detected. The control device according to claim 1 or 2.

8. The engine, a mixing device for mixing a plurality of gases at a mixing point; A pipe connecting the mixing point and the engine; The control device according to claim 1 or 2; An engine system comprising:

9. 1. A control method for an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe, the method comprising the steps of: calculating a mixing ratio obtained by compensating for a delay in the mixed fuel reaching a combustion chamber of the engine from the mixing point with respect to the mixing ratio at the mixing point; controlling the engine based on the compensated mixture ratio; The control method includes:

10. A computer of a control device controls an engine to which a mixed fuel produced by mixing a plurality of gases at a mixing point is supplied through a pipe based on a mixture ratio of the plurality of gases, calculating a mixing ratio obtained by compensating for a delay in the mixed fuel reaching a combustion chamber of the engine from the mixing point with respect to the mixing ratio at the mixing point; controlling the engine based on the compensated mixture ratio; A program that executes the following.

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