WO2023139982A1

WO2023139982A1 - Engine electricity generating system control device

Info

Publication number: WO2023139982A1
Application number: PCT/JP2022/045906
Authority: WO
Inventors: 賢吾熊野; 敦史島田; 暁史高橋
Original assignee: 株式会社日立製作所
Priority date: 2022-01-21
Filing date: 2022-12-13
Publication date: 2023-07-27
Also published as: JP2023106703A

Abstract

The objective of the present invention is to suppress a deterioration in exhaust gases and to improve availability in an electricity generating system configured from a plurality of engines capable of being supplied with renewable energy-derived fuel (RE fuel). This engine electricity generating system control device, applied to an electricity generating system in which electricity is generated by a plurality of engines capable of performing co-firing by being supplied with two or more types of fuel, is characterized by being provided with an engine state detecting means for detecting a current state of each engine, wherein a supply quantity of at least one type of fuel for each engine is controlled on the basis of a comparison result of each engine state detected by the engine state detecting means.

Description

Engine power generation system controller

The present invention relates to an engine power generation system control device compatible with fuel derived from renewable energy.

With the expansion of renewable energy toward the decarbonization of energy, the importance of regulating power generation systems using renewable energy-derived fuels such as hydrogen (hereinafter referred to as RE fuel) is increasing in order to respond to power fluctuations.

While large-scale gas-fired power generation can be used as regulating power, its output adjustment range is limited to a range of 30% to 100% of rated operation, and does not provide sufficient regulating power. In addition, since the installation location of the equipment is fixed, it is necessary to reinforce the power line, increasing the equipment cost. Furthermore, since large-scale thermal power generation is limited in the range of procurement of fuel to be used, it is difficult to make effective use of RE fuel, which is ubiquitous in the region.

A distributed power generation system that utilizes engine generators compatible with RE fuel is promising as a system that can respond to fluctuations in renewable energy while utilizing RE fuel that is ubiquitous in the region. In particular, it is possible to minimize the initial equipment cost by utilizing mass-produced engines such as existing automobile engines and industrial engines and combining them into a stationary power generation system.

Patent Document 1 is known regarding such an engine power generation system control device. Patent Document 1 describes a hydrogen engine, supply amount determining means for determining a target fuel supply amount so that an air-fuel ratio in which the amount of NOx emissions emitted from the hydrogen engine is near 0 and fuel efficiency is near an optimum point according to the operating state of the hydrogen engine; fuel supply means for supplying hydrogen fuel to the hydrogen engine based on the target fuel supply amount determined by the supply amount determining means; NOx detection means for detecting the NOx emission amount; a deterioration determining means for determining the deterioration of the fuel supply means based on the above-described deterioration determination means, the deterioration determining 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 execute hydrogen fuel supply based on the deterioration determination supply amount, and determines that the fuel supply means is deteriorated when the NOx emission amount becomes a predetermined value or more due to the hydrogen fuel supply based on the deterioration determination supply amount.

JP 2006-250056 A

When existing automobile engines or industrial engines are used for stationary power generation compatible with RE fuels such as hydrogen, failures and deterioration are more likely to occur than when conventional fuels such as gasoline are used. A power generation module that utilizes multiple engines is composed of engines with different usage conditions or engine specifications and performance. Therefore, when using RE fuel such as hydrogen (single combustion of RE fuel or mixed combustion of conventional fuel and RE fuel), problems such as deterioration of exhaust gas and abnormal combustion occur from some engines, and the operation rate of the power generation system decreases due to maintenance.

Regarding this point, with the technology described in Patent Document 1, it is difficult to deal with failures and deterioration of engine parts other than the fuel injection device, and measures for suppressing engine deterioration and exhaust deterioration in a generator system that utilizes multiple engines are not considered.

The present invention has been made in view of this situation, and aims to suppress the deterioration of exhaust gas and improve the operating rate in a power generation system composed of multiple engines capable of supplying RE fuel.

Based on the above, the present invention is defined as "an engine power generation system control device that is 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 that are capable of co-firing, 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 result of the state of each engine detected by the engine state detection means."

According to the present invention, when driving multiple engines, it is possible to adjust the supply amount of RE fuel such as hydrogen according to the state of each engine, including deterioration. Therefore, it is possible to avoid deterioration of exhaust emissions and abnormal combustion from a specific engine, and to extend the maintenance period of the power generation system and improve the operating rate by adjusting the deterioration state of each engine.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

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 using hydrogen and gasoline as fuel; FIG. FIG. 2 is a block diagram showing a hardware configuration example of the power generation system control device according to the first embodiment; FIG. The figure which shows an example of the engine structure which concerns on Example 1 of this invention. The figure which shows another example of the engine structure which concerns on Example 1 of this invention. The figure which shows the relationship between the hydrogen co-firing ratio and combustion pressure which concern on Example 1 of this invention. FIG. 4 is a graph showing the relationship between the hydrogen co-firing ratio, the maximum in-cylinder pressure, the amount of NOx emissions, and the speed at which engine deterioration progresses according to the first embodiment of the present invention; FIG. 4 is a graph showing changes in maximum in-cylinder pressure and NOx emissions during deterioration according to Embodiment 1 of the present invention; 4 is a flowchart showing an example of engine generator control according to Embodiment 1 of the present invention; FIG. 4 is a diagram for explaining the relationship between the degree of deterioration of the engine, resistance to hydrogen, and hydrogen ratio setting values according to the first embodiment of the present invention; The figure which shows the time chart of the deterioration degree of the engine which concerns on Example 1 of this invention. The figure which shows an example of the catalyst temperature and deterioration degree of the engine which concern on Example 2 of this invention. FIG. 5 is a flowchart showing an example of engine generator control according to Embodiment 2 of the present invention; FIG. 6 is a time chart showing an example of engine generator control according to Embodiment 2 of the present invention;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, constituent elements having substantially the same function or configuration are denoted by the same reference numerals, thereby omitting redundant description.

It should be noted that at least one of the fuels in the mixed combustion performed in the present invention is renewable energy-derived fuel (hereinafter referred to as RE fuel), and hydrogen is taken up in the following examples. In addition, although gasoline is exemplified as the other fuel for mixed combustion in the embodiments, light oil or natural gas (liquefied natural gas or compressed natural gas) may be used. This combination can be selected as appropriate.

FIG. 1 is a schematic configuration diagram showing an example in which a power generation system control device according to Embodiment 1 of the present invention is applied to a power generation system comprising a plurality of engine generators using hydrogen and gasoline as fuel.

The power generation system 100 is configured by connecting a plurality of sets (GM1 to GMn) of power generation modules GM, each of which is composed of an engine 11, a power generator 12, and a power converter 13, in parallel. The engine 11 is equipped with an electronic control unit (ECU) 15 for controlling each engine. The engine 11 is connected to the hydrogen generator 2 via the hydrogen supply device 14 and is capable of supplying hydrogen fuel. Also, although not shown, it is connected to a gasoline tank so that gasoline can be supplied, so that hydrogen fuel, gasoline, or a mixed fuel of hydrogen and gasoline can be combusted. Outputs of these power generation modules GM are electrically connected to the load side device 3 .

It should be noted that the minimum configuration of the power generation module GM applicable to the present invention must include the engine 11 and the generator 12, and the power converter 13 may be provided as appropriate depending on whether the load is an AC load or a DC load. Also, the generator 12 may be either an AC generator or a DC generator.

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 the load information Sg1 from the load side device 3 . Further, it receives suppliable hydrogen amount information Sg2 from the hydrogen generator 2 . Further, from the engine 11, it receives information (engine state) Sg3 on sensors and actuators of each engine. Based on these pieces of information (Sg1, Sg2, Sg3), the power generation system control device 1 sends a command Sd1 regarding the required engine output and the presence or absence of driving (hereinafter simply referred to as the required output) to the ECU 15 of each engine 11, and controls each hydrogen supply device 14 so as to achieve the desired hydrogen supply amount (hydrogen supply target amount) Sd2.

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 section, an ignition section, a throttle valve, and a starter. The engine 11 is, for example, a four-cylinder engine using spark ignition combustion, and is an example of an internal combustion engine. The driving force of the engine 11 causes the generator 12 to generate power 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 device.

Next, an internal configuration example of the power generation system control device 1 according to the first embodiment will be described. FIG. 2 is a block diagram showing a hardware configuration example of the power generation system control device 1. As shown in FIG. The power generation system control device 1 is configured using a computer device.

In FIG. 2, the input circuit 1a of the power generation system control device 1 receives the required load Sg1, the suppliable hydrogen amount Sg2, and the engine state Sg3 output from the load side device 3, the hydrogen generator 2, and the ECU 15, respectively. However, the input signal is 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 value sent to the input port is stored in RAM (1c) and processed by CPU (1e). A control program describing the contents of arithmetic processing is written in the ROM (1d) in advance.

The value indicating the operating amount of the controlled object (engine 11, hydrogen supply device 14, etc.) calculated according to the control program is stored in the RAM (1c), then sent to the output port (not shown) in the 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 (hydrogen supply target amount) Sd2. In FIG. 2, a control device (ECU 15) for each engine is separately provided for the power generation system control device 1, but the present invention is not limited to this form, and the power generation system control device 1 may include a functional unit corresponding to the control device for each device.

FIG. 3 is a diagram showing an example of the configuration of the engine 11 according to the first embodiment. The engine 11 is modified to be able to supply hydrogen to a four-cylinder gasoline engine for automobiles that implements spark ignition type combustion. An airflow sensor 21 for measuring the amount of intake air and an electronically controlled throttle 20 for adjusting the intake pipe pressure are provided at appropriate positions in each of the intake pipes 19 . In addition, the engine 11 is provided with a spark plug 18 for supplying ignition energy to the combustion chamber 17 of each cylinder for each cylinder, and a cooling water temperature sensor 25 for measuring the temperature of the cooling water of the engine is provided at an appropriate position of the cylinder head.

A gasoline fuel injection device 22 for injecting gasoline as fuel is provided in 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 the gasoline tank by a fuel pipe. Furthermore, a flow path for supplying hydrogen is provided in the intake pipe 19, 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 generator 2 by a hydrogen pipe.

Furthermore, a three-way catalyst 27 that purifies the exhaust, a catalyst temperature sensor 28 that measures the temperature of the three-way catalyst 27, and an air-fuel ratio sensor 29 that detects the air-fuel ratio of the exhaust on the upstream side of the three-way catalyst 27 are provided at appropriate positions in each of the exhaust pipes 26.

With the above configuration, it is possible to switch between engine drive using gasoline (gasoline-only combustion), engine drive using hydrogen (hydrogen-only combustion), and engine drive using hydrogen and gasoline at the same time (gasoline-hydrogen mixed combustion).

FIG. 4 is a diagram showing another configuration example of the engine 11 according to the first embodiment. The engine 11 is modified to be able to supply hydrogen to a four-cylinder gasoline engine for automobiles that implements spark ignition type combustion. An airflow sensor 21 for measuring the amount of intake air and an electronically controlled throttle 20 for adjusting the intake pipe pressure are provided at appropriate positions in each of the intake pipes 19 . In addition, the engine 11 is provided with a spark plug 18 for supplying ignition energy to the combustion chamber 17 of each cylinder for each cylinder, and a cooling water temperature sensor 25 for measuring the temperature of the cooling water of the engine is provided at an appropriate position of the cylinder head.

A gasoline fuel injection device 22 for injecting gasoline as fuel is provided in the intake pipe 19 . The gasoline fuel injector 22 is connected to the gasoline tank by a fuel line.
Furthermore, a flow path for supplying hydrogen to the combustion chamber 17 is provided and connected to a hydrogen supply device 14 for controlling the amount of hydrogen supplied. The hydrogen supply device 24 is connected to the hydrogen generator 2 by a hydrogen pipe.

FIG. 5 is a diagram showing the relationship between the hydrogen co-firing ratio and the combustion pressure (horizontal axis: crank angle, vertical axis: cylinder internal pressure) according to Example 1 of the present invention. The hydrogen co-firing 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 in-cylinder pressure history near the compression top dead center in the compression-expansion stroke. As the hydrogen co-firing ratio increases, the timing of combustion advances and the maximum in-cylinder pressure rises. Although not shown here, increasing the hydrogen co-firing ratio may cause abnormal combustion such as knocking and pre-ignition, which may lead to engine performance degradation and engine failure.

FIG. 6 is a diagram showing the relationship between the hydrogen co-firing ratio, the maximum in-cylinder pressure, the amount of NOx emissions, and the speed at which engine deterioration progresses according to Example 1 of the present invention. As shown in FIG. 5, as the hydrogen co-firing ratio on the horizontal axis increases, the combustion timing advances and the maximum in-cylinder pressure rises. If it exceeds a certain value, abnormal combustion occurs and stable operation becomes impossible. When the maximum in-cylinder pressure rises, the in-cylinder temperature also rises, so the amount of NOx produced in the exhaust gas (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 co-firing ratio accelerate the wear and deterioration of each part (piston, intake and exhaust valves, fuel injection device, spark plug) inside the engine combustion chamber. In other words, the speed at which engine deterioration progresses increases.

FIG. 7 is a diagram showing changes in maximum in-cylinder pressure and NOx emissions during deterioration according to Example 1 of the present invention. When the engine deteriorates, even if the engine is operated at the same hydrogen co-firing ratio as before deterioration, the wear and deterioration of the parts inside the engine combustion chamber as described above will cause deposits and deposits to form inside the engine, resulting in an increase in the maximum cylinder pressure and the frequency of abnormal combustion that accompanies it. In addition, the increase in the maximum in-cylinder pressure causes the in-cylinder temperature to rise, and the amount of NOx emissions also increases compared to before deterioration. In other words, depending on engine deterioration, the optimum hydrogen co-firing ratio that enables stable operation and satisfies exhaust performance changes. Therefore, in order to maintain stable and high-performance operation of the power generation system, it is necessary to detect the degree of deterioration of each engine in real time and control each engine to the optimum hydrogen co-firing ratio.

FIG. 8 is a flowchart showing an example of engine generator control according to Embodiment 1 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, current power consumption (voltage and current) of the device occurring on the load side and future predicted values. Also, when the output of the power generation system is connected to the power grid, it is the current or future power demand value from the grid side.

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

Next, the power generation system control device 1 reads the hydrogen generation information Sg2 from the hydrogen generator 2 (processing step S3). Here, the hydrogen generator is, for example, a water electrolyzer that generates hydrogen from renewable energy.

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 in consideration of the losses of the power converter 13 and the generator 12, and the like.

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, from the total required output Sd1 and the rated output of each engine power generation module, the required number of engine power generation modules to be driven is calculated, and the total required output Sd1 is evenly distributed among the engine power generation modules to be driven.

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

Next, the power generation system control device 1 calculates the hydrogen co-firing ratio in each engine based on the calculated degree of deterioration in each engine and the hydrogen generation information Sg2 from the hydrogen generator 2 (processing step S7). As shown in FIG. 7, the higher the degree of deterioration, the higher the maximum in-cylinder pressure even under the same hydrogen co-firing ratio condition, the higher the probability of occurrence of abnormal combustion and the more NOx emissions. Here, the required amount of hydrogen for the power generation system as a whole is set so as to be equal to or not exceed the hydrogen-producible amount obtained from the hydrogen generator.

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

Next, the power generation system control device 1 executes hydrogen supply amount control so as to realize the hydrogen co-firing ratio of each engine calculated in processing step S7 (processing step S9). The individual hydrogen supply amount command values (Sd21, Sd22, .

FIG. 9 is a diagram for explaining the relationship between the degree of deterioration of the engine, hydrogen resistance, and the hydrogen ratio set value according to the first embodiment of the present invention. Here, for example, a power generation system in which five different engines, engine A, engine B, engine C, engine D, and engine E, are connected in parallel will be described. The engine A, engine B, and engine C are of the in-cylinder injection type in which hydrogen is directly supplied into the cylinder, and are highly resistant to hydrogen (engine configuration shown in FIG. 3). On the other hand, the engine D and the engine E are of the intake pipe injection type in which hydrogen is supplied into the intake pipe and have low resistance to hydrogen (engine configuration shown in FIG. 4).

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

The lower part of FIG. 9 shows the hydrogen co-firing ratio of each engine set by the power generation system control device 1 based on the degree of deterioration of the engine and the resistance to hydrogen of the engine. The hydrogen co-firing ratio of engine A, which has the lowest degree of deterioration, is set to be the highest, and the hydrogen co-firing ratios of the other engines are set to be low as the degree of deterioration increases. When the degree of deterioration is the same (for example, engine B and engine D, engine C and engine E), the hydrogen co-firing rate is set higher for the engine with higher resistance to hydrogen. The dotted line indicates the required average hydrogen co-firing ratio. The required average hydrogen co-firing ratio is the average hydrogen co-firing ratio of each engine calculated based on the amount of hydrogen generated by the hydrogen generator 2. The hydrogen supply amount is controlled so that the actual average of the hydrogen co-firing ratio of each engine matches the required average hydrogen co-firing ratio.

FIG. 10 is a diagram showing a time chart of the degree of deterioration of the engine according to Example 1 of the present invention. From the top, the deterioration degree of the engine A, the deterioration degree of the engine B, the deterioration degree of the engine C, the deterioration degree of the engine D, and the deterioration degree of the engine E (time scale in units of months and years). The solid line indicates the degree of deterioration when the present invention is applied, and the dotted line indicates the conventional degree of deterioration. When the deterioration degree reaches the deterioration limit value (Limit), it means that maintenance or repair is required. The initial value of the degree of deterioration of each engine at time 0 conforms to the assumption in FIG.

In the past, there were variations in the initial value of the degree of deterioration of each engine, so if they were used with the same frequency of use, there would be variations in the timing of reaching the limit of deterioration. In this example, engine B, which has the highest degree of deterioration at the earliest stage, reaches the deterioration limit earliest at time ta, requiring maintenance of power generation system 100 .

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 degree of deterioration of each engine. For example, in engine B, which has a high degree of initial deterioration, the hydrogen co-firing ratio is set low, so the pressure in the cylinder is kept low as shown in FIG. As a result, it is possible to delay the timing of reaching the deterioration limit. Conversely, for engine A with a low initial deterioration degree, the hydrogen co-firing ratio is set high, so the degree of deterioration progresses and the deterioration limit is reached earlier. With the above control, the deterioration limit reaching times of all the engines (A to E) are aggregated around the time tb, the maintenance time of the power generation system 100 is extended, and maintenance can be performed on each engine at once. Therefore, maintenance frequency and cost can be suppressed, and the operating rate can be improved.

In the present embodiment, a method of uniformizing the deterioration limit timing based on the degree of deterioration of each engine and efficiently performing simultaneous maintenance of the power generation system 100 has been described. However, in the power generation system 100 in which maintenance can be performed for each engine power generation module, the deterioration limit reaching timing of each engine may be intentionally varied to continue the operation of the power generation system 100 (to suppress the complete shutdown of the power generation system) even during the maintenance of each power generation module, thereby improving the operation rate.

Also, in this embodiment, the hydrogen resistance of each engine is evaluated by the hydrogen supply position, but it may be evaluated by the specifications of each engine (compression ratio, displacement) and the combustion state during hydrogen co-combustion.

As is clear from the above description, the present invention is an engine power generation system control device 1 that is applied to a power generation system 100 that generates power by a plurality of engines 11 capable of supplying two or more types of fuel, comprising state detection means (e.g., ECU) 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 result of each engine state (e.g., the degree of deterioration in FIG. 9) detected by the state detection means ECU. In other words, the present invention determines the fuel for each engine based on the relative condition of the engines.

Example 2 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.

FIG. 11 is a diagram showing an example of catalyst temperature and degree of deterioration of the engine according to Embodiment 2 of the present invention. The assumption of the degree of deterioration of each engine (A to E) shown in the lower part of FIG. 11 is the same as in FIG. 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 achieve its original purification performance when the temperature exceeds a certain temperature (catalyst activation temperature), but below the catalyst activation temperature, the purification performance is insufficient, and NOx etc. can not be purified and will be discharged from the engine. Since the three-way catalyst is warmed by the engine exhaust, the catalyst temperature rises as the engine runs. When the engine stops, the catalyst temperature gradually decreases due to heat radiation to the surrounding gas. In this example, the catalyst temperatures of engine B, engine D, and engine E are equal to or higher than the catalyst activation temperature, and engine A and engine C are lower than the catalyst activation temperature.

FIG. 12 is a flowchart showing an example of start and stop control of an engine generator according to Embodiment 2 of the present invention.

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, current power consumption (voltage and current) of the device occurring on the load side and future predicted values. Also, when the output of the power generation system is connected to the power grid, it is the current or future power demand value from the grid side.

Next, the power generation system control device 1 calculates the 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 in consideration of the losses of the power converter 13 and the generator 12, and the like.

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

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

Next, the power generation system control device 1 determines the starting order of each engine based on the catalyst temperature of the engine and the degree of deterioration of the engine (processing step S15). After that, a start command is sent to each engine (processing step S16), and the series of control ends.

FIG. 13 is a time chart showing an example of start and stop control of the engine generator according to Embodiment 2 of the present invention. From the top of FIG. 13, when the system is started from the stopped state, 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 NOx emission amount transition from the power generation system. A solid line indicates the case where the present invention is applied, and a dotted line indicates the conventional control.

In the conventional control indicated by the dotted line, when the power generation request starts at time ta, the engine A starts and starts power generation based on a predetermined order. When the required output further increases and reaches time tb, engine B starts, and then engine C starts at time tc. After that, the engine C stops at the time td and the engine B stops at the time te as the requested power generation output decreases. Here, as shown in FIG. 12, since the catalyst temperature of engine A and engine C is lower than the catalyst activation temperature, exhaust components cannot be purified immediately after starting (time ta and time tc), and a large amount of NOx is produced.

On the other hand, when this control is applied, when the power generation request starts at time ta, the engine E whose catalyst temperature is equal to or higher than the catalyst activation temperature and whose degree of deterioration is low is preferentially started. When the required output further increases and reaches time tb, engine D whose catalyst temperature is equal to or higher than the catalyst activation temperature is started, and then engine B is started at tc. After that, the engine B stops at the time td and the engine D stops at the time te as the requested power generation output decreases. Since the catalyst temperature of all engines used for power generation is equal to or higher than the catalyst activation temperature, the exhaust purification efficiency is high even immediately after engine start (time ta, time tb, and time tc), and NOx can be significantly reduced compared to conventional control.

In this embodiment, the power generation system control device 1 determines the engine start order using the catalyst temperature as the engine temperature, but may determine the instruction order based on the cooling water temperature of the engine.

The present invention is not limited to the above-described embodiments, and it goes without saying that various other application examples and modifications are possible as long as they do not depart from the gist of the present invention described in the claims.

For example, each of the above-described embodiments is a detailed and specific description of the configuration of the device and system in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the configurations described. Further, it is possible to replace part of the configuration of the embodiment described here with the configuration of another embodiment, and furthermore, it is possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

In addition, the control lines and information lines indicate what is considered necessary for explanation, and not all control lines and information lines are necessarily indicated on the product. In practice, it may be considered that almost all configurations are interconnected.

1: power generation system control device, 1a: input circuit, 1b: input/output port, 1c: RAM, 1d: ROM, 1e: CPU, 1f: engine torque control output unit, 1g: hydrogen supply amount control output unit, 2: hydrogen generation device, 3: load side device, 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 device 23: High pressure fuel pump 24: Gas fuel supply device 25: Cooling water temperature sensor 26: Exhaust pipe 27: Three-way catalyst 28: Catalyst temperature sensor 29: Air-fuel ratio sensor

Claims

An engine power generation system control device 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 are capable of co-firing,
An engine power generation system control device comprising engine state detection means for detecting a current state of each engine, and controlling 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.
The engine power generation system control device according to claim 1,
The engine power generation system control device, wherein the engine state detection means detects the degree of deterioration of each engine.
The engine power generation system control device according to claim 2,
The engine power generation system control device, wherein the engine state detection means detects the temperature of each engine.
The engine power generation system control device according to claim 2,
An engine power generation system control device, characterized in that the ratio of two or more types of fuel supplied to each engine is controlled according to the degree of deterioration of each engine detected by the engine state detection means.
The engine power generation system control device according to claim 2,
One of the fuels to be supplied is hydrogen, and the ratio of the amount of hydrogen to the total amount of supplied fuel is set lower for an engine with a higher deterioration degree of the engine detected by the engine state detection means.
The engine power generation system control device according to claim 2,
The engine power generation system control device, wherein the engine state detection means detects the degree of engine deterioration from at least one of an operating time of the engine, an internal cylinder pressure, a rotation speed, and an ignition signal.
The engine power generation system control device according to claim 3,
The temperature of the engine is the temperature of the exhaust purification catalyst provided in the exhaust pipe of each engine, and the engine power generation system control device characterized in that the temperature of the exhaust purification catalyst preferentially starts the engine whose temperature is equal to or higher than a predetermined temperature.
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 hydrogen adaptability evaluation means for evaluating the hydrogen fuel adaptability of each engine, wherein the higher the hydrogen adaptability of each engine obtained from the hydrogen adaptability evaluation means, the higher the ratio of the amount of hydrogen to the total amount of fuel supplied is set.
The engine power generation system control device according to claim 8,
The engine power generation system control device, wherein the hydrogen adaptability evaluation means determines the hydrogen adaptability from a fuel supply method of the engine, a compression ratio of the engine, and a displacement of the engine.