Engine power generation system control device

Abstract

To suppress exhaust deterioration and improve an operation rate, in a power generation system composed of a plurality of engines capable of supplying RE fuel.SOLUTION: An engine power generation system controller applied to a power generation system that generates power by a plurality of engines that are supplied with two or more types of fuel and enable co-firing, comprises engine state detection means of detecting a current state of each engine. The engine power generation system controller controls at least one type of fuel supply amount for each engine based on a comparison result of each engine state detected by the engine state detection means.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a control device for an engine power generation system compatible with fuel derived from renewable energy. [Background technology]

[0002] As renewable energy expands in an effort to decarbonize energy, the importance of balancing power generation systems that use renewable energy-derived fuels (hereinafter referred to as RE fuels) such as hydrogen to respond to power fluctuations is increasing.

[0003] While large-scale gas-fired power plants can be used as adjustable power, their output adjustment range is limited to 30% to 100% of rated operation, which does not provide sufficient adjustment power. In addition, since the installation location of the facilities is fixed, it is necessary to reinforce the power lines, which increases the facility costs. Furthermore, since the procurement range of fuel to be used is limited for large-scale thermal power plants, it is difficult to effectively utilize RE fuels that are ubiquitous in the region.

[0004] Distributed power generation systems using engine generators compatible with RE fuel are promising as systems that can respond to fluctuations in renewable energy while utilizing RE fuel, which is ubiquitous in the region. In particular, by utilizing mass-produced engines such as existing automobile engines and industrial engines and combining multiple of them as stationary power generation systems, it is possible to minimize initial equipment costs.

[0005] Regarding such an engine power generation system control device, Patent Document 1 is known. Patent Document 1 discloses a hydrogen fuel supply device including: a hydrogen engine; a supply amount determination means for determining a target fuel supply amount according to an operating state of the hydrogen engine so that the amount of NOx discharged from the hydrogen engine is close to zero and the air-fuel ratio is close to an optimum point for fuel efficiency; a fuel supply means for supplying hydrogen fuel to the hydrogen engine based on the target fuel supply amount determined by the supply amount determination means; a NOx detection means for detecting the NOx emissions; and a deterioration determination means for determining deterioration of the fuel supply means based on a detection value of the NOx detection means under a predetermined execution condition, wherein the deterioration determination means sets a deterioration determination supply amount obtained by adding a preset additional amount to the target fuel supply amount determined by the supply amount determination means, causes the fuel supply means to supply hydrogen fuel based on the deterioration determination supply amount, and determines that the fuel supply means is deteriorated when the NOx emissions become equal to or greater than a predetermined value due to the hydrogen fuel supply based on the deterioration determination supply amount. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-250056 A Summary of the Invention [Problem to be solved by the invention]

[0007] When existing automobile engines or industrial engines are used for stationary power generation using RE fuels such as hydrogen, they are more susceptible to breakdowns and deterioration than when conventional fuels such as gasoline are used. In a power generation module that uses multiple engines, since they are composed of engines with different operating conditions or engine specifications and performance, when using RE fuels such as hydrogen (single-fuel combustion of RE fuel or mixed combustion of conventional fuel and RE fuel), some engines may experience problems such as deterioration of exhaust emissions or abnormal combustion, which can lead to a problem of reduced availability of the power generation system for maintenance.

[0008] In this regard, the technology described in Patent Document 1 has difficulty dealing with failures and deterioration of engine parts other than the fuel injection device, and does not take into consideration measures to suppress engine deterioration and exhaust deterioration in generator systems that utilize multiple engines.

[0009] The present invention has been made in view of the above circumstances, and has an object to suppress deterioration of exhaust emissions and improve the availability rate in a power generation system composed of multiple engines to which RE fuel can be supplied. [Means for solving the problem]

[0010] In view of the above, the present invention provides an engine power generation system control device that is applied to a power generation system that generates power using a plurality of engines capable of mixed combustion when supplied with two or more types of fuel, the engine power generation system control device comprising engine means for detecting the current state of each engine, and controlling the amount of at least one type of fuel supplied to each engine based on the comparison results of each engine state detected by the engine state detection means. Effect of the Invention

[0011] According to the present invention, when multiple engines are driven, it is possible to adjust the supply amount of RE fuel such as hydrogen depending on the condition of each engine, including its deterioration. This makes it possible to avoid exhaust deterioration and abnormal combustion from a specific engine, and by adjusting the deterioration state of each engine, it is possible to extend the maintenance period for the power generation system and improve the operating rate.

[0012] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0013] [Figure 1]1 is a schematic configuration diagram showing an example in which a power generation system control device according to a first embodiment of the present invention is applied to a power generation system including a plurality of engine generators fueled by hydrogen and gasoline. [Diagram 2] FIG. 2 is a block diagram showing an example of a hardware configuration of the power generation system control device according to the first embodiment. [Diagram 3] FIG. 1 is a diagram showing an example of an engine configuration according to a first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing another example of the engine configuration according to the first embodiment of the present invention. [Diagram 5] FIG. 4 is a diagram showing the relationship between the hydrogen-mixed combustion ratio and the combustion pressure according to the first embodiment of the present invention. [Figure 6] FIG. 4 is a diagram showing the relationship between the hydrogen-mixed combustion ratio and the maximum in-cylinder pressure, NOx emissions, and engine deterioration progression speed according to the first embodiment of the present invention. [Figure 7] FIG. 4 is a diagram showing changes in maximum in-cylinder pressure and NOx emissions during deterioration according to the first embodiment of the present invention. [Figure 8] 4 is a flowchart showing an example of engine generator control according to the first embodiment of the present invention. [Figure 9] FIG. 4 is a diagram for explaining the relationship between the deterioration degree, hydrogen resistance, and hydrogen ratio set value of the engine according to the first embodiment of the present invention. [Figure 10] FIG. 2 is a diagram showing a time chart of the deterioration degree of the engine according to the first embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing an example of a catalyst temperature and a deterioration degree of an engine according to a second embodiment of the present invention. [Figure 12] 6 is a flowchart showing an example of engine generator control according to a second embodiment of the present invention. [Figure 13] 5 is a time chart showing an example of engine generator control according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functions or configurations are designated by the same reference numerals, and redundant description will be omitted.

[0015] At least one of the fuels in the mixed combustion carried out in the present invention is a renewable energy-derived fuel (hereinafter referred to as RE fuel), and hydrogen is used in the following examples. Although gasoline is used as an example of the other fuel in the mixed combustion in the examples, it may be diesel or natural gas (liquefied natural gas or compressed natural gas). This combination can be selected as appropriate. EXAMPLES

[0016] First Embodiment FIG. 1 is a schematic configuration diagram showing an example in which a power generation system control device according to a first embodiment of the present invention is applied to a power generation system including a plurality of engine generators that use hydrogen and gasoline as fuel.

[0017] The power generation system 100 is configured by connecting multiple sets of power generation modules GM (GM1 to GMn) in parallel, each set being made up of an engine 11, a generator 12, and a power converter 13, and the engine 11 is equipped with an electronic control unit (ECU) 15 for controlling each engine. The engine 11 is connected to a hydrogen generator 2 via a hydrogen supply device 14, so that hydrogen fuel can be supplied. The engine 11 is also connected to a gasoline tank (not shown) so that gasoline can be supplied, so that hydrogen fuel, gasoline, or a mixture of hydrogen and gasoline can be burned. The output of these power generation modules GM is electrically connected to a load side device 3.

[0018] The minimum configuration of the power generation module GM applicable to the present invention is that it is necessary to include an engine 11 and a generator 12, and depending on whether the load is an AC load or a DC load, an appropriate power converter 13 may be included. The generator 12 may be either an AC generator or a DC generator.

[0019] The power generation system control device 1 is mounted on the power generation system 100. The power generation system control device 1 calculates the required load of the power generation system based on load information Sg1 from the load side device 3. It also receives supplyable hydrogen amount information Sg2 from the hydrogen generation device 2. It also receives information (engine state) Sg3 of the sensors and actuators of each engine from the engine 11. Based on this information (Sg1, Sg2, Sg3), the power generation system control device 1 sends the engine required output and a command on whether to drive (hereinafter simply referred to as required output) Sd1 to the ECU 15 of each engine 11, and controls each hydrogen supply device 14 to realize a desired hydrogen supply amount (target hydrogen supply amount) Sd2.

[0020] The ECU 15 controls the output of the engine 11 based on the required output Sd1 from the power generation system control device 1. Specifically, the ECU 15 controls a gasoline fuel injection unit, an ignition unit, a throttle valve, and a starter. The engine 11 is, for example, a four-cylinder engine that uses spark ignition combustion, and is an example of an internal combustion engine. The generator 12 generates power using the driving force of the engine 11 to achieve a desired power load. The power converter 13 adjusts the voltage and phase of the power generated by the generator 12 and supplies the power to the load side equipment.

[0021] Next, a description will be given of an internal configuration example of the power generation system control device 1 according to the embodiment 1. Fig. 2 is a block diagram showing a hardware configuration example of the power generation system control device 1. The power generation system control device 1 is configured using a computer device.

[0022] In Fig. 2, the required load Sg1, the supplyable hydrogen amount Sg2, and the engine state Sg3 output from the load side device 3, the hydrogen generator 2, and the ECU 15, respectively, are input to the input circuit 1a of the power generation system control device 1. However, the input signals are not limited to these. Each signal input to the input circuit 1a is sent to an input port (not shown) in the input / output port 1b. The values ​​sent to the input port are stored in the RAM (1c) and processed by the CPU (1e). A control program describing the contents of the processing is written in advance in the ROM (1d).

[0023] Values ​​indicating the operating amounts of the controlled objects (engine 11, hydrogen supply device 14, etc.) calculated according to the control program are stored in RAM (1c), and then sent to an output port (not shown) in input / output port 1b, and sent to each device (ECU 15, hydrogen supply device 14) via each output section (engine torque control output section 1f, hydrogen supply amount control output section 1g) as a required output Sd1 and a desired hydrogen supply amount (target hydrogen supply amount) Sd2. Note that in FIG. 2, the control devices (ECU 15) for each engine are provided separately from the power generation system control device 1, but this is not limited to the configuration, and functional sections corresponding to the control devices of each device may be provided within the power generation system control device 1.

[0024] 3 is a diagram showing an example of the configuration of an engine 11 according to the first embodiment. The engine 11 is a four-cylinder gasoline engine for an automobile that performs spark ignition combustion and has been modified so that hydrogen can be supplied to the engine. An air flow sensor 21 that measures the amount of intake air and an electronically controlled throttle 20 that adjusts the intake pipe pressure are provided at appropriate positions in each intake pipe 19. In addition, the engine 11 is provided with a spark plug 18 for each cylinder that supplies ignition energy into the combustion chamber 17 of each cylinder, and a coolant temperature sensor 25 that measures the temperature of the engine coolant is provided at an appropriate position in the cylinder head.

[0025] A gasoline fuel injection device 22 for injecting gasoline as fuel is provided inside the combustion chamber 17, and a high-pressure fuel pump 23 for supplying high-pressure fuel to the gasoline fuel injection device 22 is connected to the gasoline fuel injection device 22 by a fuel pipe. The high-pressure fuel pump 23 is connected to a gasoline tank by a fuel pipe. Furthermore, a flow path for supplying hydrogen into the intake pipe 19 is provided, and is connected to a hydrogen supply device 14 that controls the amount of hydrogen supplied. The hydrogen supply device 24 is connected to the hydrogen generation device 2 by a hydrogen pipe.

[0026] Furthermore, a three-way catalyst 27 that purifies the exhaust gas, a catalyst temperature sensor 28 that measures the temperature of the three-way catalyst 27, and an air-fuel ratio sensor 29 which is one form of an air-fuel ratio detector and detects the air-fuel ratio of the exhaust gas upstream of the three-way catalyst 27 are provided at appropriate positions in the exhaust pipe 26.

[0027] With the above configuration, it is possible to switch between engine operation using gasoline (single-fuel gasoline combustion), engine operation using hydrogen (single-fuel hydrogen combustion), and engine operation using both hydrogen and gasoline at the same time (gasoline-hydrogen mixed combustion).

[0028] 4 is a diagram showing another example of the configuration of the engine 11 according to the first embodiment. The engine 11 is a four-cylinder gasoline engine for an automobile that performs spark ignition combustion and has been modified so that hydrogen can be supplied to the engine. An air flow sensor 21 that measures the amount of intake air and an electronically controlled throttle 20 that adjusts the intake pipe pressure are provided at appropriate positions in each intake pipe 19. In addition, the engine 11 is provided with a spark plug 18 for each cylinder that supplies ignition energy into the combustion chamber 17 of each cylinder, and a coolant temperature sensor 25 that measures the temperature of the engine coolant is provided at an appropriate position in the cylinder head.

[0029] A gasoline fuel injection device 22 for injecting gasoline as fuel is provided in the intake pipe 19. The gasoline fuel injection device 22 is connected to a gasoline tank by a fuel pipe. Furthermore, a flow path for supplying hydrogen into the combustion chamber 17 is provided, and is connected to a hydrogen supply device 14 that controls the amount of hydrogen supplied. The hydrogen supply device 24 is connected to the hydrogen generation device 2 by a hydrogen pipe.

[0030] Furthermore, a three-way catalyst 27 that purifies the exhaust gas, a catalyst temperature sensor 28 that measures the temperature of the three-way catalyst 27, and an air-fuel ratio sensor 29 which is one form of an air-fuel ratio detector and detects the air-fuel ratio of the exhaust gas upstream of the three-way catalyst 27 are provided at appropriate positions in the exhaust pipe 26.

[0031] With the above configuration, it is possible to switch between engine operation using gasoline (single-fuel gasoline combustion), engine operation using hydrogen (single-fuel hydrogen combustion), and engine operation using both hydrogen and gasoline at the same time (gasoline-hydrogen mixed combustion).

[0032] FIG. 5 is a diagram showing the relationship between the hydrogen-mixed combustion ratio and the combustion pressure (horizontal axis: crank angle, vertical axis: cylinder pressure) according to the first embodiment of the present invention. The hydrogen-mixed combustion ratio is the ratio of the amount of hydrogen to the total amount of fuel (gasoline and hydrogen combined) supplied to each engine. The figure shows the history of cylinder pressure near the compression top dead center during the compression-expansion stroke. As the hydrogen-mixed combustion ratio is increased, the combustion timing is advanced and the maximum cylinder pressure is increased. Although not shown here, further increasing the hydrogen-mixed combustion ratio may cause abnormal combustion such as knocking or pre-ignition, which may lead to reduced engine performance or engine failure.

[0033] FIG. 6 is a diagram showing the relationship between the hydrogen-mixed combustion ratio and the maximum cylinder pressure, NOx emissions, and engine deterioration progression speed according to the first embodiment of the present invention. As shown in FIG. 5, as the hydrogen-mixed combustion ratio on the horizontal axis increases, the combustion timing advances and the maximum cylinder pressure increases. If it exceeds a certain value, abnormal combustion occurs and stable operation becomes impossible. When the maximum cylinder pressure increases, the cylinder temperature also increases, and the amount of NOx generated in the exhaust (especially thermal NOx, which is strongly affected by the combustion temperature) increases. Furthermore, the increase in the maximum pressure and the occurrence of abnormal combustion due to the increase in the hydrogen-mixed combustion ratio promotes wear and deterioration of each part (piston, intake and exhaust valve, fuel injection device, spark plug) inside the engine combustion chamber. In other words, the engine deterioration progression speed increases.

[0034] FIG. 7 is a diagram showing the change in maximum cylinder pressure and NOx emissions during deterioration according to the first embodiment of the present invention. When an engine deteriorates, even if it is operated at the same hydrogen-mixed combustion ratio as before deterioration, deposits and deposits are generated inside the engine due to wear and deterioration of parts inside the engine combustion chamber as described above, and the maximum cylinder pressure increases and the frequency of abnormal combustion increases accordingly. In addition, the increase in maximum cylinder pressure also increases the cylinder temperature, and NOx emissions also increase compared to before deterioration. In other words, the optimal hydrogen-mixed combustion ratio for stable operation and satisfying exhaust performance changes due to engine deterioration. Therefore, in order to maintain stable and high-performance operation of the power generation system, it is necessary to detect the deterioration degree of each engine in real time and control each engine to the optimal hydrogen-mixed combustion ratio.

[0035] Fig. 8 is a flowchart showing an example of engine generator control according to the first embodiment of the present invention. The power generation system control device 1 first reads information Sg1 from the connected load device 3 (processing step S1). The information Sg1 from the load device 3 is, for example, the current power consumption (voltage and current) of the device on the load side and a future predicted value. Also, when the output of the power generation system is connected to a power grid, the information Sg1 is the current or future power request value from the grid side.

[0036] Next, the power generation system control device 1 reads information Sg3 of each engine from each ECU 15 and the engine 11 (processing step S2). The information Sg3 from the ECU 15 and the engine 11 includes, for example, engine conditions such as the current engine speed, torque, and engine temperature (catalyst temperature, coolant temperature, intake temperature, etc.) and engine specifications (displacement, compression ratio, fuel supply position, etc.).

[0037] Next, the power generation system control device 1 reads hydrogen generation information Sg2 from the hydrogen generator 2 (processing step S3). Here, the hydrogen generator is, for example, a water electrolytic cell that generates hydrogen from renewable energy, and information such as the power that can be input to the water electrolytic cell and output efficiency is read into the power generation system 1.

[0038] Next, the power generation system control device 1 calculates the load required for the power generation system based on the information Sg1 from the load device 3 (processing step S4). Here, the total required output for the engine is calculated taking into account losses in the power converter 13 and the generator 12, etc.

[0039] Next, the power generation system control device 1 distributes the calculated total required output Sd1 to each engine power generation module to obtain individual required outputs Sd11, Sd12, ... Sd1n (processing step S5). For example, the number of engine power generation modules required to be driven is calculated from the total required output Sd1 and the rated output of each engine power generation module, and the total required output Sd1 is evenly distributed among the driven engine power generation modules.

[0040] Next, the power generation system control device 1 calculates the deterioration degree of the engine based on the information Sg3 from the ECU 15 and the engine 11 (processing step S6). For example, the deterioration degree of each engine is calculated from the cumulative engine driving time and cumulative output, or the engine combustion state (combustion timing, combustion stability, exhaust performance).

[0041] Next, the power generation system control device 1 calculates the hydrogen mixing ratio for each engine based on the calculated deterioration level of each engine and the hydrogen generation information Sg2 from the hydrogen generation device 2 (processing step S7). As shown in Fig. 7, the higher the deterioration level, the higher the probability of abnormal combustion occurring due to an increase in maximum cylinder pressure even under the same hydrogen mixing ratio conditions, and the amount of NOx emissions increases. Therefore, the power generation system control device 1 compares the deterioration levels of each engine and sets the hydrogen mixing ratio so that the hydrogen mixing ratio is lower for engines with a higher deterioration level. Here, the total amount of hydrogen required by the power generation system is set to be equal to or not exceed the amount of hydrogen that can be generated from the hydrogen generation device.

[0042] Next, the power generation system control device 1 sends the torque command values ​​(individual required outputs Sd11, Sd12, . . . Sd1n) for each engine calculated in process step S5 to each ECU 15 (process step S8).

[0043] Next, the power generation system control device 1 executes hydrogen supply amount control so as to realize the hydrogen mixed combustion ratio for each engine calculated in process step S7 (process step S9). Individual hydrogen supply amount command values ​​(Sd21, Sd22, ... Sd2n) are sent to each engine (process step S9), and the series of controls is terminated.

[0044] 9 is a diagram for explaining the relationship between the deterioration degree, hydrogen tolerance, and hydrogen ratio set value of an engine according to the first embodiment of the present invention. Here, the explanation is given assuming a power generation system in which five different engines, engine A, engine B, engine C, engine D, and engine E, are connected in parallel. Engines A, B, and C are in-cylinder injection type engines that supply hydrogen directly into the cylinders and have high hydrogen tolerance (engine configuration shown in FIG. 3). On the other hand, engines D and E are intake manifold injection type engines that supply hydrogen into the intake manifold and have low hydrogen tolerance (engine configuration shown in FIG. 4).

[0045] 9 shows the deterioration degree of each engine obtained by the power generation system control device 1. Here, engine A has the lowest deterioration degree, followed by engine C and engine E, and engines B and D have the highest deterioration degrees.

[0046] The bottom of Figure 9 shows the hydrogen mixing ratio for each engine, set by the power generation system control device 1 based on the engine deterioration level and hydrogen tolerance of the engine. The hydrogen mixing ratio for engine A, which has the lowest deterioration level, is set to the highest, and as the deterioration level increases, the hydrogen mixing ratios for the other engines are set to lower. In the case of engines with the same deterioration level (for example, engines B and D, or engines C and E), the engine with higher hydrogen tolerance is set to a higher hydrogen mixing ratio. The dotted line shows the required average hydrogen mixing ratio. The required average hydrogen mixing ratio is the average hydrogen mixing ratio for each engine calculated based on the amount of hydrogen generated by the hydrogen generation device 2, and the amount of hydrogen supply is controlled so that the average of the actual hydrogen mixing ratios for each engine matches the required average hydrogen mixing ratio.

[0047] FIG. 10 is a diagram showing a time chart of the deterioration degree of the engine according to the first embodiment of the present invention. From the top, the deterioration degree of engine A, the deterioration degree of engine B, the deterioration degree of engine C, the deterioration degree of engine D, and the deterioration degree of engine E change over time (time scale in months and years). The solid line indicates the deterioration degree when the present invention is applied, and the dotted line indicates the conventional deterioration degree. When the deterioration degree reaches the deterioration limit value (Limit), it means that maintenance or repair is required. The initial value of the deterioration degree of each engine at time 0 is based on the assumption in FIG. 9.

[0048] Conventionally, because there is variation in the initial deterioration level of each engine, if the engines are operated at the same frequency of use, there is also variation in the time at which the deterioration level limit is reached. In this example, engine B, which has the highest initial deterioration level, reaches its deterioration limit earliest at time ta, and maintenance of the power generation system 100 is required.

[0049] On the other hand, in the system to which the present invention is applied, the hydrogen co-firing ratio is controlled and adjusted based on the deterioration level of each engine. For example, in engine B, which has a high initial deterioration level, the hydrogen co-firing ratio is set low, so that the pressure inside the cylinder is kept low as shown in FIG. 6, and the deterioration rate is reduced. As a result, it is possible to delay the time when the deterioration limit is reached. Conversely, in engine A, which has a low initial deterioration level, the hydrogen co-firing ratio is set high, so that the deterioration rate increases and the time when the deterioration limit is reached is advanced. Through the above control, the deterioration limit reaching times of all engines (A to E) are concentrated around time tb, which extends the maintenance period of the power generation system 100 and allows maintenance to be performed on each engine at the same time, making it possible to reduce the maintenance frequency and costs and improve the operating rate.

[0050] In this embodiment, a method has been described for standardizing the deterioration limit time based on the deterioration level of each engine, thereby efficiently carrying out simultaneous maintenance of the power generation system 100. However, in a power generation system 100 in which maintenance can be performed on each engine-power generation module, the deterioration limit reaching time of each engine may be intentionally varied to continue operation of the power generation system 100 even during maintenance of each power generation module (preventing a complete shutdown of the power generation system), thereby improving the operating rate.

[0051] In addition, in this embodiment, the hydrogen tolerance of each engine is evaluated based on the hydrogen supply position, but it may also be evaluated based on the specifications of each engine (compression ratio, displacement) or the combustion state during hydrogen co-combustion.

[0052] As is clear from the above description, the present invention is an engine power generation system control device 1 applied to a power generation system 100 that generates power using multiple engines 11 to which two or more types of fuel can be supplied, characterized in that it includes a state detection means (e.g., ECU) that detects the current state of each engine, and controls the amount of at least one type of fuel supplied to each engine based on a comparison result of each engine state (e.g., deterioration degree in FIG. 9) detected by the state detection means ECU. In other words, in the present invention, the fuel for each engine is determined based on the relative state of the engines. EXAMPLES

[0053] A second embodiment of the present invention will be described. In this embodiment, engine start and stop control is performed. The system configuration and hardware configuration are the same as those of the first embodiment. The system configuration and hardware configuration according to this embodiment are the same as those of the first embodiment.

[0054] FIG. 11 is a diagram showing an example of the catalyst temperature and deterioration degree of an engine according to the second embodiment of the present invention. The assumed deterioration degree of each engine (A to E) shown in the bottom of FIG. 11 is the same as that shown in FIG. 9. The top of FIG. 11 shows the three-way catalyst temperature in the exhaust gas obtained from the ECU 15 or the engine 11 of each engine. The three-way catalyst can realize its original purification performance when it exceeds a certain temperature (catalytic activation temperature), but below the catalyst activation temperature, the purification performance is insufficient, and NOx and the like cannot be purified and are discharged from the engine. Since the three-way catalyst is heated by the exhaust gas of the engine, the catalyst temperature increases with the engine operation time. When the engine stops, the catalyst temperature gradually decreases due to heat dissipation to the surrounding gas. In this example, the catalyst temperatures of engines B, D, and E are equal to or higher than the catalyst activation temperature, and those of engines A and C are lower than the catalyst activation temperature.

[0055] FIG. 12 is a flowchart showing an example of start and stop control of the engine generator according to the second embodiment of the present invention.

[0056] The power generation system control device 1 first reads information Sg1 from the connected load device 3 (processing step S11). The information Sg1 from the load device 3 is, for example, the current power consumption (voltage and current) of the device on the load side and a future predicted value. Also, when the output of the power generation system is connected to a power grid, the information Sg1 is the current or future power request value from the grid side.

[0057] Next, the power generation system control device 1 calculates a load Sd1 required for the power generation system based on the information Sg1 from the load device 3 (processing step S12). Here, the total required output Sd1 for the engine is calculated taking into account losses in the power converter 13 and the generator 12, etc.

[0058] Next, the power generation system control device 1 reads information Sg3 of each engine from each ECU 15 and the engine 11 (processing step S13). The information Sg3 from the ECU 15 and the engine 11 includes, for example, engine conditions such as the current engine speed, torque, and engine temperature (catalyst temperature, coolant temperature, intake temperature, etc.) and engine specifications (displacement, compression ratio, fuel supply position, etc.).

[0059] Next, the power generation system control device 1 calculates the deterioration degree of the engine based on the information Sg3 from the ECU 15 and the engine 11 (processing step S14). For example, the deterioration degree of each engine is calculated from the cumulative engine driving time and cumulative output, or the engine combustion state (combustion timing, combustion stability, exhaust performance).

[0060] Next, the power generation system control device 1 determines the start order of each engine based on the catalyst temperature of the engine and the deterioration degree of the engine (processing step S15), and then sends a start command to each engine (processing step S16), and ends the series of controls.

[0061] Fig. 13 is a time chart showing an example of start and stop control of an engine generator according to the second embodiment of the present invention. From the top of Fig. 13, changes in the required output of the power generation system, the output of engine A, the output of engine B, the output of engine C, the output of engine D, the output of engine E, and the integrated value of NOx emissions from the power generation system when starting from a system stopped state are shown. The case where the present invention is applied is shown with a solid line, and the conventional control is shown with a dotted line.

[0062] In conventional control shown by the dotted line, when a request to generate electricity begins at time ta, engine A starts and begins generating electricity based on a predetermined hierarchy. When the required output increases further and reaches time tb, engine B starts, and then engine C starts at time tc. Then, as the required power generation output decreases, engine C stops at time td and engine B stops at time te. Here, as shown in Figure 12, the catalyst temperatures of engines A and C are below the catalyst activation temperature, so they are unable to purify exhaust components immediately after starting (at times ta and tc), and so end up producing a large amount of NOx.

[0063] On the other hand, when this control is applied, when a request for power generation begins at time ta, engine E, whose catalyst temperature is above the catalyst activation temperature and has a low level of degradation, is given priority for starting. When the required output increases further and reaches time tb, engine D, whose catalyst temperature is also above the catalyst activation temperature, starts, and then engine B starts at time tc. Then, as the required power generation output decreases, engine B stops at time td and engine D stops at time te. Because the catalyst temperatures of all of the engines used for power generation are above the catalyst activation temperature, the exhaust purification efficiency is high even immediately after engine start (times ta, tb, and tc), and NOx can be significantly reduced compared to conventional control.

[0064] In this embodiment, the power generation system control device 1 determines the engine start order using the catalyst temperature as the engine temperature, but the instruction order may be determined based on the engine coolant temperature.

[0065] The present invention is not limited to the above-described embodiments, and it goes without saying that various other applications and modifications are possible without departing from the gist of the present invention as set forth in the claims.

[0066] For example, the above-mentioned embodiments have described the configuration of the device and system in detail and specifically in order to explain the present invention in an easily understandable manner, and are not necessarily limited to those including all of the configurations described. In addition, it is possible to replace part of the configuration of the embodiments described here with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0067] In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are connected to each other. [Explanation of symbols]

[0068] 1: Power generation system control device 1a: Input circuit 1b: Input / Output port 1c:RAM 1d:ROM 1e:CPU 1f: Engine torque control output section 1g: Hydrogen supply amount control output section 2: Hydrogen generator 3: Load side equipment 11: Engine 12: Generator 13: Power converter 14: Hydrogen supply device 15: ECU 17: Combustion chamber 18: Spark plug 19: Intake pipe 20:Throttle 21: Air flow sensor 22: Gasoline fuel injection system 23: High pressure fuel pump 24: Gas fuel supply device 25: Coolant temperature sensor 26: Exhaust pipe 27:Three-way catalyst 28: Catalyst temperature sensor 29: Air-fuel ratio sensor

Claims

1. An engine power generation system control device that is applied to a power generation system that generates power using a plurality of engines that are supplied with two or more types of fuel and are capable of co-firing the fuel, An engine power generation system control device comprising engine state detection means for detecting the current state of each engine, and controlling at least one type of fuel supply amount to each engine based on a comparison result of each engine state detected by the engine state detection means.

2. The engine power generation system control device according to claim 1, 2 is a block diagram showing an engine power generation system control apparatus according to the first embodiment of the present invention;

3. The engine power generation system control device according to claim 2, 2 is a block diagram showing an engine state detection means for detecting a temperature of each engine;

4. The engine power generation system control device according to claim 2, 2. An engine power generation system control device, comprising: a control unit for controlling a ratio of amounts of two or more types of fuel supplied to each engine according to a deterioration level of each engine detected by said engine state detection means.

5. The engine power generation system control device according to claim 2, 1. An engine power generation system control device comprising: a control unit for controlling an engine state of an engine that is supplied with hydrogen; and a control unit for controlling an engine state of an engine that is supplied with hydrogen;

6. The engine power generation system control device according to claim 2, 2. An engine power generation system control device, wherein the engine condition detection means detects a degree of engine deterioration from at least one of an operating time, an in-cylinder pressure, a rotation speed, and an ignition signal of the engine.

7. The engine power generation system control device according to claim 3, The engine temperature is the temperature of an exhaust purification catalyst provided in the exhaust pipe of each engine, and an engine having a temperature of the exhaust purification catalyst equal to or higher than a predetermined temperature is started preferentially.

8. The engine power generation system control device according to claim 2, the power generation system is composed of a plurality of engines capable of supplying two or more types of fuel including hydrogen; An engine power generation system control device comprising a hydrogen adaptability evaluation means for evaluating the hydrogen fuel adaptability of each engine, and setting a higher ratio of hydrogen to the total fuel supply amount for an engine having a higher hydrogen adaptability obtained from said hydrogen adaptability evaluation means.

9. The engine power generation system control device according to claim 8, 2. An engine power generation system control device, wherein the hydrogen adaptability evaluation means determines hydrogen adaptability from a fuel supply method of the engine, a compression ratio of the engine, and a displacement of the engine.

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