JP2022155267A - fuel cell system - Google Patents

Abstract

To provide a fuel cell system capable of quickly and reliably responding to a power reception point power reduction command.SOLUTION: A fuel cell system comprises a fuel cell 1, an operation controller C, and a management device. The operation controller C receives an output control command from the management device, before a power reception point power reduction execution date and time when a power reception point power of a facility is to be reduced, changes a mode from a load following mode to a rating output mode where the fuel cell 1 is controlled to operate at a rating output, and supplies a surplus power, which is a difference between the rating output mode and the load following mode, to a power consumption device 9 different from a power load unit in the load following mode until the power reception point power reduction execution date and time.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fuel cell system connected to a power system.

2. Description of the Related Art Conventionally, a fuel cell system including a fuel cell connected to a commercial system (electric power system) is known (see, for example, Patent Document 1).

The fuel cell system described in Patent Document 1 boosts the voltage of electric power generated by a fuel cell with a DC/DC converter, converts it into alternating current with an inverter, and supplies the converted electric power to household loads. Moreover, the surplus electric power exceeding the electric power consumption of the household load is supplied from the driving circuit provided in the DC/DC converter to the heater in the hot water storage tank that stores hot water. As a result, reverse power flow is prevented, and work during a power outage is prevented from being hindered.

JP-A-2007-267508

In recent years, a virtual power plant (VPP, virtual power station) that provides supply capacity and the like by bundling demand-side resources such as fuel cells provided in each facility to increase or decrease demand is becoming widespread. In this VPP, for example, a resource aggregator that controls resources such as fuel cells raises or lowers power at receiving points of each facility based on a supply command from an aggregation coordinator to supply adjustment power. For example, power can be supplied to the power system by issuing a power receiving point power reduction command from the resource aggregator to each facility.

In the fuel cell system described in Patent Document 1, by allowing the heater to consume surplus power, it is possible to prevent unintended collapse of supply and demand balance due to reverse power flow. output must be raised immediately. On the other hand, the fuel cell has a limit on the output fluctuation speed because it controls the amount of power by adjusting the amount of fuel gas, air, and water, and there is a possibility that it may not be able to respond to the power reduction command at the power receiving point.

Therefore, a fuel cell system is desired that can respond quickly and reliably to a power-receiving point power reduction command.

A characteristic configuration of the fuel cell system according to the present invention is a fuel cell installed in each of a plurality of facilities and capable of outputting electric power, an operation control unit for controlling the operation of the fuel cell, and a plurality of the fuel cells. and a management device capable of communicating from outside the facility between the fuel cell, wherein the fuel cell is capable of supplying electric power generated by operation to an electric power load unit, and supplying electric power generated by operation to the electric power system The operation control unit controls the operation of the fuel cell in a load following mode that follows the load power of the power load unit, and the management device controls the operation control unit , the operation control unit is configured to be able to transmit an output control command that determines the output power of the fuel cell, and the operation control unit receives the output control command from the management device and receives power to reduce power at the power receiving point of the facility Before the point power reduction execution date and time, the load following mode is changed to the rated output mode for controlling the operation of the fuel cell at the rated output, and the surplus power that is the difference between the rated output mode and the load following mode is reduced to the The point is that power is supplied to a power consumption device different from the power load unit in the load following mode until the power receiving point power reduction execution date and time.

In this configuration, the operation mode of the fuel cell is changed from the load following mode to the rated output mode before the power receiving point power reduction execution date and time. In other words, the output of the fuel cell is raised to the rated output, which is the maximum output, before the date and time of execution of the power reduction at the power receiving point, which is assumed in advance, to ensure the necessary amount of power to be supplied to the power system. As a result, it is possible to quickly and reliably respond to the receiving point power reduction command.

In addition, since the surplus power, which is the difference between the rated output mode and the load following mode, is supplied to a power consumption device other than the power load unit until the power receiving point power reduction execution date and time, stable power to the power load unit is supplied. Surplus power can be effectively utilized without wasting it while ensuring supply (load-following operation). Then, when the power receiving point power down execution date and time comes, it is only necessary to transfer the surplus power to the power system, so it is possible to quickly and reliably respond to the power receiving point power down command.

Another characteristic configuration is that the operation control unit increases the output of the fuel cell so that the rated output mode is set on the power receiving point power reduction execution date and time.

As in this configuration, if the output of the fuel cell is increased so as to enter the rated output mode at the power receiving point power reduction execution date and time, it is possible to reduce the amount of surplus power. Therefore, for example, even if the amount of power that can be consumed by the power consuming device is small, the surplus power is not wasted.

A characteristic configuration of the fuel cell system according to the present invention is a fuel cell installed in each of a plurality of facilities and capable of outputting electric power, an operation control unit for controlling the operation of the fuel cell, and a plurality of the fuel cells. and a management device capable of communicating from outside the facility between the fuel cell, wherein the fuel cell is capable of supplying electric power generated by operation to an electric power load unit, and supplying electric power generated by operation to the electric power system The operation control unit controls the operation of the fuel cell in a rated output mode, and the management device provides the operation control unit with the fuel It is configured to be able to transmit an output control command that determines the output power of the battery, and the operation control unit receives the output control command from the management device and reduces the power receiving point power of the facility. wherein surplus power exceeding the load power of the power load unit is supplied to a power consumption device different from the power load unit, and in the power receiving point power reduction execution period, reverse flow power for supplying power to the power system and the When an adjusted surplus power exceeding the load power of the power load unit is generated, the adjusted surplus power is supplied to the power consuming device.

In this configuration, the operation mode of the fuel cell is set to the rated output mode before the power receiving point power reduction execution date and time. In other words, the output of the fuel cell is set to the rated output, which is the maximum output, before the date and time of execution of the power reduction at the power receiving point, which is assumed in advance, to ensure the necessary amount of power to be supplied to the power system. As a result, it is possible to quickly and reliably respond to the receiving point power reduction command.

In addition, even if there is a demand-side resource that does not transfer all of the surplus power to the power grid during the power receiving point power reduction execution period, the surplus power is It can be used effectively without wasting it.

A characteristic configuration of the fuel cell system according to the present invention is a fuel cell installed in each of a plurality of facilities and capable of outputting electric power, an operation control unit for controlling the operation of the fuel cell, and a plurality of the fuel cells. and a management device capable of communicating from outside the facility between the fuel cell, wherein the fuel cell is capable of supplying electric power generated by operation to an electric power load unit, and supplying electric power generated by operation to the electric power system The operation control unit controls the operation of the fuel cell in a predetermined output mode in which a predetermined output exceeds the load power of the power load unit, and the management device controls the operation of the fuel cell. The operation control unit is configured to be able to transmit an output control command that determines the output power of the fuel cell, and the operation control unit receives the output control command from the management device and determines the power reception point power of the facility. surplus power exceeding the load power of the power load unit is supplied to a power consumption device different from the power load unit except during the power receiving point power reduction execution period, and the predetermined output mode is performed during the power reception point power reduction execution period to the rated output mode in which the operation of the fuel cell is controlled at the rated output.

In this configuration, the operation mode of the fuel cell is set to a predetermined output mode in which operation is controlled at a predetermined output that exceeds the load power of the power load section and is lower than the rated output before the receiving point power reduction execution date and time, and the receiving point power reduction is executed. During the period, the predetermined output mode is changed to the rated output mode in which the operation of the fuel cell is controlled at the rated output. In other words, a certain amount of extra fuel cell output is secured before the date and time of execution of power reduction at the power receiving point, and in preparation for the necessary amount of power to be supplied to the power system, during the power reduction execution period at the power reception point, fuel By setting the battery output to the rated output, which is the maximum output, the required amount of power to be supplied to the power system is ensured. As a result, it is possible to quickly and reliably respond to the receiving point power reduction command.

In addition, since the surplus power, which is the difference between the predetermined output mode and the load following mode, is supplied to a power consuming device other than the power load unit until the power receiving point power reduction execution date and time, stable power is supplied to the power load unit. Surplus power can be effectively used without wasting it while ensuring supply.

Another characteristic configuration is that the electric heater is arranged in the hot water circulation path between the heat exchanger through which the combustion exhaust gas of the fuel cell flows and the hot water storage tank that stores hot water.

As in this configuration, if the power consuming device is configured with an electric heater arranged in the hot water circulation path, the electric heater can be installed later. More freedom.

FIG. 2 is a diagram showing the relationship among facilities, management devices, and aggregation coordinators; 1 is a diagram showing a configuration example of a fuel cell system; FIG. 1 is an overall configuration diagram of a fuel cell device; FIG. It is a figure explaining the 1st Example of a control form. It is a figure explaining the modification of 1st Example of a control form. It is a figure explaining the 2nd Example of a control form. It is a figure explaining the 3rd Example of a control form.

An embodiment of a fuel cell system according to the present invention will be described below with reference to the drawings. In the present embodiment, as an example of a fuel cell system, a fuel cell system used in a supply and demand adjustment market, a wholesale power market, a capacity market, etc. will be described. However, without being limited to the following embodiments, various modifications are possible without departing from the scope of the invention.

[Overall overview]
FIG. 1 is a diagram showing the relationship between a facility 100 in which a fuel cell device X and a power load section 3 are installed, a management device G, and an aggregation coordinator Z. As shown in FIG. FIG. 2 is a diagram showing a configuration example of the facility 100. As shown in FIG. The fuel cell system is installed in each of a plurality of facilities 100 and is capable of outputting electric power, and communication can be performed between the plurality of fuel cell devices X from a remote location outside the facility 100. and a management device G. Note that the number of management apparatuses G and the number of facilities 100 shown in FIG. 1 can be changed as appropriate.

The management device G is also called a resource aggregator or the like, and provides the facility 100 with which the virtual power plant (VPP, virtual power plant) service contract has been concluded with the fuel cell device X and the power load section 3 as energy resources on the consumer side. It is a business operator that controls the energy resource on the consumer side by transmitting control information. Aggregation coordinator Z aggregates the amount of electric power controlled by each management device G, and conducts electric power transactions with general power transmission and distribution companies and retail power companies in the electricity trading market (supply and demand adjustment market, wholesale electricity market, capacity market, etc.). is a business operator.

As shown in FIGS. 1 and 2, the management device G receives the output power of the fuel cell device X, the load power of the power load unit 3, the receiving point power of the power meter M at the facility 100, etc. from the plurality of facilities 100. Power information is collected and stored sequentially. In this embodiment, the term “load power of the power load units 3 ” means the total load power of all the power load units 3 provided in the facility 100 . Then, the management device G predicts the power that can be supplied from each facility 100 in a predetermined time period in the future, and notifies the aggregation coordinator Z of the predicted power. This power that can be supplied is an adjustment margin such as the ability to increase or decrease the power at the receiving point of the facility 100 . In the present embodiment, when "increasing power at the receiving point" means increasing the received power (forward flow power) from the power system 15 to the power line PL, or the reverse flow power from the power line PL to the power system 15 When it is said to "reduce the power at the receiving point", the received power (forward flow power) from the power system 15 to the power line PL is reduced, or the reverse power flow from the power line PL to the power system 15 means to increase power.

For example, in order to increase the receiving point power of the facility 100, at least one of decreasing the output power of the fuel cell device X and increasing the load power of the power load unit 3 is performed. The increase adjustment margin for raising the point power indicates how much margin there is for reducing the output power of the fuel cell device X, and indicates how much margin there is for increasing the load power of the power load section 3 . In addition, in order to lower the receiving point power of the facility 100, at least one of increasing the output power of the fuel cell device X and decreasing the load power of the power load unit 3 is performed. The reduction adjustment margin for decreasing the point power indicates how much margin there is for increasing the output power of the fuel cell device X, and indicates how much margin there is for decreasing the load power of the power load section 3 .

In addition, the management device G determines baseline power reception point power in the plurality of facilities 100 managed by itself. This baseline power receiving point power is predicted when each facility 100 does not supply the adjustment capacity (that is, including the adjustment capacity provided to the power transmission and distribution business operator and the supply capacity provided to the retail business operator, etc.). It corresponds to the sum of the receiving point power of each facility 100 .

Aggregation coordinator Z aggregates the supplyable power received from each management device G and conducts bidding in trading markets such as the supply and demand adjustment market, wholesale power market, capacity market, etc. Do business with businesses. When Aggregation Coordinator Z receives a supply command for adjustment capacity, etc. in a predetermined future control target period from a general power transmission and distribution business operator or a retail electricity business operator with whom aggregation coordinator Z has traded, The adjustment force and the like are distributed and transmitted to each management device G.

When receiving a delivery command from the aggregation coordinator Z, the management device G distributes and transmits the adjustment power and the like specified in the delivery command to each facility 100 . As a result, in each facility 100, control of the fuel cell device X and the electric power load unit 3 as energy resources on the consumer side is performed during a predetermined control target period in the future. As a result, adjustment power or the like for increasing or decreasing the power at the receiving point of the facility 100 is provided.

A facility 100 is provided with a fuel cell device X and a power load section 3 . The fuel cell device X and the power load section 3 are connected to a power line PL interconnected with the power system 15 . A power meter M for measuring the power received by the facility 100 is installed on the power line PL. Although FIGS. 1 and 2 show an example in which one fuel cell device X is installed in each facility 100, the number of installed fuel cell devices X can be changed as appropriate.

Information on the power at the receiving point measured by the power meter M is transmitted to the management device G via the gateway GW and router RT. For example, information about the power at the receiving point is transmitted to the management device G at predetermined timing such as every 10 seconds.

The power load unit 3 is various devices such as a lighting device and an air conditioner, and can receive power supply from at least one of the fuel cell device X installed in the facility 100 and the power system 15 .

A fuel cell device X includes a solid oxide fuel cell 1 interconnected to a power system 15 . Further, the power generated by the solid oxide fuel cell 1 is converted into a predetermined voltage, frequency, and phase by the power converter 12 and supplied to the power line PL. The operations of the fuel cell device X and the power conversion section 12 are controlled by the operation control section C. FIG.

The operation control unit C can adjust the output power from the fuel cell device X to the power line PL between a predetermined upper limit output power and a predetermined lower limit output power. For example, the operation control unit C can maintain the output power of the fuel cell device X at the upper limit output power and cause continuous operation (rated output operation). The operation control unit C can also perform an operation (load following operation) in which the output power of the fuel cell device X follows the load power of the power load unit 3 . For example, the operation control unit C adjusts the output power of the fuel cell device X so that the power supplied from the power system 15 becomes zero or a value close to zero, thereby following the load power of the power load unit 3. can make you drive.

Since the operation control unit C has information about the output power supplied from the power conversion unit 12 to the power line PL and information about the power measured by the power meter M, the load power of the power load unit 3 (=output power + measured power) can be derived. When the sign of the power measured by the power meter M is plus (forward flow), it means that the load power is greater than the output power of the fuel cell device X, and the sign of the power measured by the power meter M is is negative (reverse power flow), it means that the output power of the fuel cell device X is greater than the load power.

The fuel cell device X is connected to a remote controller RM operated by a user of the facility 100 to issue a command to the fuel cell device X. FIG. Information about the output power of the fuel cell device X, information about the load power, and the like are transmitted to the management device G via the remote control RM and the router RT. For example, the information about the output power and the information about the load power of the fuel cell device X are transmitted to the management device G at a predetermined timing such as every minute.

As described above, the management device G can transmit to a plurality of fuel cell devices X an output control command that determines the output power of the fuel cell device X. FIG. Then, when the fuel cell device X receives the output control command from the management device G, the fuel cell device X aims to supply the output power determined based on the output control command during the control target period that is the target of the output control command. It operates in the operating mode, and operates in a second operating mode different from the first operating mode during a non-controlled period outside the controlled period.

The first operation mode is the day when an output control command (output increase/decrease request in the balancing market, activation command for the capacity market, etc.) is expected in the balancing market, wholesale power market, or capacity market This is an operation mode for adjusting the output power of a plurality of fuel cell devices X on the power increase command day. In this first operation mode, the date and time when the facility 100 is requested to lower the power at the receiving point is referred to as the "receiving point power lowering command date and time", and the date and time when the facility 100 is requested to increase the power at the receiving point is referred to as the "power receiving point Point power increase command date and time”.

The second operation mode is an operation mode preset in the plurality of fuel cell devices X. As shown in FIG. Alternatively, the management device G can transmit an operation mode control command that defines the second operation mode to the plurality of fuel cell devices X, and the fuel cell device X receives the second operation mode control command in accordance with the operation mode control command received from the management device G. Determine driving mode. For example, the second operation mode includes an operation in which the output power of the fuel cell device X is maintained at the upper limit output power (rated output operation), and an operation in which the output power of the fuel cell device X follows the load power of the power load unit 3 (load power operation). follow-up driving) and so on.

[Configuration of fuel cell system]
FIG. 3 is a diagram showing the configuration of the fuel cell device X. As shown in FIG. The fuel cell system includes the management device G, the fuel cell device X, the power conversion section 12, and the operation control section C that controls the operations of the fuel cell device X and the power conversion section 12 described above. The operation control unit C is composed of hardware and software having an information processing function, an information storage function, an information communication function, etc., and is provided in each facility 100, but part or all of it is provided in the management device G. It's okay to be.

The fuel cell device X converts the electric power generated by the operation from direct current to alternating current by the power conversion unit 12 and supplies it to the electric power load unit 3, and supplies the heat generated by the operation to the heat load unit 4 Solid oxide fuel. A battery 1 (an example of a fuel cell) is provided. The power load unit 3 can consume power supplied from the power system 15 in addition to the power supplied from the solid oxide fuel cell 1 . That is, the solid oxide fuel cell 1 can convert the electric power generated by operation from direct current to alternating current by the power conversion unit 12 and supply it to the power load unit 3, and the electric power from the power system 15 to the power load unit 3 It is interconnected with the power system 15 in a state in which it can be supplied and in a state in which it is possible to supply the power generated by the operation to the power system 15 .

In addition to the heat generated from the solid oxide fuel cell 1, the heat load unit 4 can also consume heat supplied from the auxiliary heat source device 11 that generates heat by burning the raw fuel.

The solid oxide fuel cell 1 includes a vaporizer 1b that evaporates the supplied reforming water, and a raw fuel (hydrocarbon-containing gas, for example, city gas 13A) that is steam-reformed to produce a fuel gas (hydrogen-containing gas). ), a cell stack having a plurality of fuel cells S for generating power using the fuel gas generated by the reformer 1a, a combustion unit 1c for burning off-gas from the cell stack, is provided inside the container 1A. It is preferable that the container 1A is constructed using a material having heat insulating properties. The cell stack is electrically connected to power converter 12 .

A gas manifold 1e for receiving the fuel gas supplied from the reformer 1a through the fuel gas flow path L4 is provided at the bottom of the cell stack. The fuel gas supplied to the gas manifold 1e flows upward from the lower ends of the plurality of fuel cells S and is used for power generation reaction. The discharged fuel gas after being subjected to the power generation reaction is discharged from the fuel gas discharge port 50a at the upper end.

The solid oxide fuel cell 1 is provided with an air introduction portion 70 to which an air supply channel L5 is connected. 23 are provided. By operating the air blower 22, air is supplied into the container 1A through the air supply flow path L5. The air filter 21 catches foreign matter such as dust in the air sucked into the air supply passage L5 by the air blower 22 . The air flow meter 23 measures the flow rate per unit time of the air supplied into the container 1A. The air in the container 1A flows through each of the plurality of fuel cells S from the lower side to the upper side, and is used for power generation reaction. After being subjected to the power generation reaction, the exhaust air is discharged from the upper end air discharge port 60a. The measurement result of the air flow meter 23 is transmitted to the operation control section C, and the operation control section C controls the operation of the air blower 22 .

The container 1A has an exhaust section 80 formed at its lower portion for discharging the flue gas generated in the combustion section 1c to the outside through the heat exchanger E. As shown in FIG. A combustion catalyst portion 90 (for example, a platinum-based catalyst) is provided in the container 1A for removing carbon monoxide gas and the like in the combustion exhaust gas discharged from the exhaust portion 80 to the outside.

The vaporizer 1b heats and evaporates the supplied reforming water using combustion heat transferred from the combustion section 1c. The reforming water stored in the reforming water tank 24 is supplied to the vaporizer 1 b through a reforming water flow path L2 connected to the reforming water tank 24 . Specifically, when the reforming water pump P operates, the reforming water stored in the reforming water tank 24 flows through the reforming water flow path L2 into the vaporizer 1b. An operation controller C controls the operation of the reforming water pump P. FIG. In this way, the reforming water pump P functions as a water flow rate adjusting section that adjusts the flow rate per unit time of the reforming water supplied to the reformer 1a.

The raw fuel is also supplied to the vaporizer 1b through the raw fuel flow path L1. A mass flow meter Fa and a raw fuel blower B are provided in the middle of the raw fuel flow path L1. For the mass flowmeter Fa, for example, a thermal mass flowmeter that performs measurement using the heat diffusion action of raw fuel is used. Furthermore, in the raw fuel flow path L1 on the downstream side of the raw fuel blower B, a desulfurizer 20 for removing sulfur compounds contained in the raw fuel (for example, city gas or the like) is provided. By operating the raw fuel blower B, the raw fuel flows through the raw fuel flow path L1, is desulfurized by the desulfurizer 20, and then flows into the vaporizer 1b. The mass flowmeter Fa measures the flow rate per unit time of the raw fuel supplied to the vaporizer 1b, and the measurement result is transmitted to the operation controller C. When the mass flowmeter Fa is a thermal mass flowmeter, the operation control unit C refers to the stored value of the heat quantity of the supplied raw fuel to determine the flow rate of the raw fuel. The operation control unit C controls the operations of the raw fuel blower B and the later-described opening/closing valve V1 so that the flow rate of the raw fuel measured using the mass flow meter Fa reaches a target flow rate. In this manner, the raw fuel blower B and the opening/closing valve V1 function as a raw fuel flow rate adjusting section that adjusts the flow rate of the raw fuel supplied to the reformer 1a per unit time. As described above, in the vaporizer 1b, a mixed gas in which the raw fuel and water vapor are mixed and whose supply amount per unit time is controlled by the operation control unit C is generated and reformed through the mixed gas flow path L3. supplied to the device 1a.

The reformer 1a performs a steam reforming process on the raw fuel contained in the mixed gas supplied from the vaporizer 1b. Although not shown, the interior of the reformer 1a is filled with a reforming catalyst, and the raw fuel is reformed by the catalytic action of the reforming catalyst. Combustion heat generated in the combustion section 1c is also transferred to the reformer 1a in the same manner as the vaporizer 1b.

The power generated by the solid oxide fuel cell 1 is supplied to the power converter 12 . The power converter 12 converts the power generated by the solid oxide fuel cell 1 into the same voltage, same phase, and same frequency as the power received from the power system 15 . An operation control unit C controls the operation of the power conversion unit 12 . The power conversion unit 12 is electrically connected to the power receiving power supply line 14 via the generated power supply line 13 . Then, the generated power from the solid oxide fuel cell 1 is supplied to the power load section 3 via the power conversion section 12, the generated power supply line 13 and the received power supply line 14 (corresponding to the power line PL described above). This power receiving power supply line 14 is connected to a power system 15 . That is, the solid oxide fuel cell 1 is interconnected with the power system 15 in such a state that the power generated by operation can be converted from direct current to alternating current by the power converter 12 and supplied to the power system 15 .

A power load measuring unit 16 that measures the power load of the power load unit 3 is provided on the power receiving power supply line 14 , and the measurement result is transmitted to the operation control unit C. Then, the operation control unit C adjusts the output power of the fuel cell device X so that the power supplied from the power system 15 becomes zero or a value close to zero, thereby following the load power of the power load unit 3. Operation (load following operation in the second operation mode) can be performed. This load following operation may control the generated power of the solid oxide fuel cell 1 based on the measured value of the power at the power receiving point near the power meter M described above, or may be detected by the power load measuring unit 16. Control may be performed so that the power load and the generated power supplied from the solid oxide fuel cell 1 to the power receiving power supply line 14 are equal. In addition, the operation control unit C can also operate the solid oxide fuel cell 1 at the rated output (the gas flow rate supplied to the solid oxide fuel cell 1 is 120 to 130 L / h) (second operating mode rated output operation). However, in the load following operation, the power load measured by the power load measuring unit 16 is the minimum generated power of the solid oxide fuel cell 1 (minimum generated power supplied to the power receiving power supply line 14 by the power conversion unit 12) If less than , excess power is generated. Moreover, in the rated output operation mode, surplus power is also generated when the solid oxide fuel cell 1 is operated at the rated output and the output power from the power converter 12 is greater than the power load. The surplus power is consumed by an electric heater 9 (an example of a power consumption device) for surplus power consumption that recovers the surplus power instead of heat.

The electric heater 9 is composed of a plurality of resistance heaters, and heats hot water flowing through the exhaust heat recovery path 6 by the operation of the exhaust heat recovery pump 7 . ON/OFF of the electric heater 9 is switched by an operation switch 10 connected to the output side of the power converter 12 . The operation switch 10 is switched so that the power consumption of the electric heater 9 increases as the amount of surplus power of the solid oxide fuel cell 1 increases. The operation control section C controls the operation of the operation switch 10 .

It should be noted that it is possible to appropriately set what devices are included in the power consumption devices that consume surplus power. For example, as a power consumption device different from the power load unit 3, instead of the electric heater 9 or in addition to the electric heater 9, auxiliary equipment used to operate the solid oxide fuel cell 1, a heat load unit An anti-freezing heater, a storage battery, or the like may be included to prevent the hot water supplied to 4 from freezing.

The hot water tank 2 stores the heat generated by the solid oxide fuel cell 1 in the form of hot water. That is, the hot water storage tank 2 stores hot water heated by using the heat generated by the operation of the solid oxide fuel cell 1 . Tap water is supplied to the lower portion of the hot water storage tank 2 through a water supply passage 17 . Inside the hot water storage tank 2, relatively low-temperature hot water is stored in the lower part, and relatively high-temperature hot water is stored in the upper part.

By operating the exhaust heat recovery pump 7, the hot water stored in the hot water storage tank 2 passes through the exhaust heat recovery path 6 and passes through the heat exchanger E through which the combustion exhaust gas of the solid oxide fuel cell 1 flows and the hot water storage. It circulates between tanks 2. A heat radiator 8 is installed in the middle of the exhaust heat recovery path 6 for radiating heat from the hot water flowing from the hot water storage tank 2 to the heat exchanger E through the exhaust heat recovery path 6 . The relatively high temperature hot water stored in the upper portion of the hot water storage tank 2 is supplied to the heat load section 4 via the hot water supply path 5 and the auxiliary heat source device 11 connected to the upper portion of the hot water storage tank 2 .

The heat load unit 4 is used for hot water supply, heating, and the like. When the heat load unit 4 is used for hot water supply, hot water does not return to the hot water storage tank 2 . When the heat load unit 4 is used for heating, only the heat retained by the hot water is consumed, and the hot water may return to the hot water storage tank 2 .

The fuel gauge Y indicates the raw fuel (fuel) supplied to the solid oxide fuel cell 1 through the raw fuel flow path L1, and the auxiliary heat source device 11, the gas stove, and other fuel consumption equipment K. The total volume of the raw fuel (fuel) supplied through the raw fuel flow path L6 is measured.

[Control Mode by Operation Control Unit]
Next, a control mode related to the operation control section C of the fuel cell system will be described. As described above, the management device G can transmit to a plurality of fuel cell devices X an output control command (output increase/decrease request) that determines the output power of the fuel cell device X. FIG. The fuel cell device X operates in the first operation mode aiming at supplying output power determined based on this output control command. On the other hand, when there is no output control command, it operates in a second operation mode different from the first operation mode. As the second operation mode, when an operation (load following operation) is performed in which the output power of the fuel cell device X follows the load power of the power load unit 3, a power receiving point power reduction command (request to increase the output of the fuel cell device X) is performed. ), due to the characteristics of the solid oxide fuel cell 1, surplus power cannot be immediately secured.

Therefore, as shown in FIGS. 4 to 7, the operation control unit C in the present embodiment receives a power-receiving point power reduction command from the management device G and reduces the power of the facility 100 before the power-receiving point power reduction execution date and time. Alternatively, the amount of fuel gas supplied to the solid oxide fuel cell 1, the amount of air, and A surplus power generation operation is performed to generate surplus power by adjusting at least one of the amounts of water. This surplus power is stored in the exhaust heat recovery path 6 (hot water It is consumed by an electric heater 9 (an example of a power consumption device) arranged in a circulation path). Here, the "receiving point power reduction execution date and time" is the date and time when the receiving point power is reduced after a predetermined time (for example, 45 minutes) from the "receiving point power reduction command date and time" planned in advance. . Similarly, the “receiving point power reduction execution period” is a predetermined period for reducing the receiving point power.

The operation control unit C controls the raw fuel blower B and the opening/closing valve V1 in the surplus electric power generating operation, adjusts the fuel gas amount per unit time of the raw fuel supplied to the reformer 1a, and controls the air blower 22. to adjust the amount of air per unit time supplied to the container 1A, and control the reforming water pump P to adjust the amount of reforming water supplied to the reformer 1a per unit time. do. As a result, for example, when the date and time when the power receiving point power reduction command is expected is known in advance, the power receiving point power reduction execution date and time is calculated from the power receiving point power reduction command date and time, and the necessary amount of power to be supplied to the power system 15 is calculated. Secure virtually. As a result, it is possible to quickly and reliably respond to the receiving point power reduction command.

[First embodiment]
FIG. 4 shows a first embodiment of the surplus power generation operation by the operation control section C. As shown in FIG. In the second operation mode, the fuel cell device X in this embodiment performs an operation (load following operation) in which the output power of the solid oxide fuel cell 1 follows the load power of the power load section 3 . As shown in the figure, the operation control unit C receives a power point power reduction command from the management device G and reduces the power reception point power of the facility 100 before the power reception point power reduction execution date and time. to follow the load power of the power load unit 3 (load following operation in the second operation mode) to the rated output mode (rated output in the second operation mode) in which the operation of the solid oxide fuel cell 1 is controlled at the rated output operation), and the surplus power, which is the difference between the rated output mode and the load following mode, is supplied to the electric heater 9 until the power receiving point power reduction execution date and time. In other words, the output of the solid oxide fuel cell 1 is increased to the rated output, which is the maximum output, before the date and time of execution of power reduction at the power receiving point assumed in advance, and the necessary amount of power to be supplied to the power system 15 is secured. do. As a result, it is possible to quickly and reliably respond to the receiving point power reduction command.

In this embodiment, the surplus power, which is the difference between the rated output mode and the load following mode, is supplied to the electric heater 9 different from the power load unit 3 until the power receiving point power reduction execution date and time. While ensuring a stable power supply (load following mode), it is possible to effectively utilize surplus power without wasting it. Then, when the power receiving point power down execution date and time comes, it is only necessary to transfer the surplus power to the power grid 15, so it is possible to quickly and reliably respond to the power receiving point power down command. Further, since the electric heater 9 can be installed later, the degree of freedom is high, such as changing the scale of the electric heater 9 according to the amount of surplus electric power.

[Modification of first embodiment]
As shown in FIG. 5, the operation control unit C may increase the output of the solid oxide fuel cell 1 so as to enter the rated output mode on the power receiving point power reduction execution date and time. In this way, by increasing the output of the solid oxide fuel cell 1 so as to enter the rated output mode on the date and time when the power is reduced at the power receiving point, it is possible to reduce the amount of surplus power. Therefore, for example, even if the amount of power that can be consumed by the electric heater 9 is small, the surplus power is not wasted.

[Second embodiment]
FIG. 6 shows a second embodiment of the surplus power generation operation by the operation control section C. As shown in FIG. In the second operation mode, the fuel cell device X in this embodiment is operated (rated output operation) in which the output power of the solid oxide fuel cell 1 is the rated output (maximum output). As shown in the figure, the operation control unit C reduces the load power of the power load unit 3 during periods other than the receiving point power reduction execution period to reduce the receiving point power of the facility 100 in response to a receiving point power reduction command from the management device G. surplus power is supplied to the electric heater 9, and in the power receiving point power reduction execution period, when the adjusted surplus power exceeding the output power (reverse flow power) to the power system 15 and the load power of the power load unit 3 is generated, The adjusted surplus power is supplied to the electric heater 9 . In other words, the output of the solid oxide fuel cell 1 is set to the rated output, which is the maximum output, before the date and time of execution of the power reduction at the power receiving point assumed in advance, and the required amount of power to be supplied to the power system 15 is ensured. As a result, it is possible to quickly and reliably respond to the receiving point power reduction command. Further, even if there is a demand-side resource that does not transfer all the surplus power to the power system 15 during the power receiving point power reduction execution period, since the adjusted surplus power is supplied to the electric heater 9 different from the power load unit 3, Surplus power can be used effectively without wasting it.

[Third embodiment]
FIG. 7 shows a third embodiment of the surplus power generation operation by the operation control section C. In FIG. The fuel cell device X in this embodiment sets the output power of the solid oxide fuel cell 1 to a predetermined output (output smaller than the rated output and larger than the load power of the power load unit 3) as the second operation mode. It is in operation (predetermined output operation). As shown in the figure, the operation control unit C receives a power-receiving point power reduction command from the management device G and reduces the power-receiving point power of the facility 100 except for the power-receiving point power reduction execution period. While operating in a predetermined output mode that controls operation at a predetermined output, surplus power exceeding the load power of the power load unit 3 is supplied to the electric heater 9, and in the power receiving point power reduction execution period, the solid oxide fuel is changed from the predetermined output mode. Change to the rated output mode in which the operation of the battery 1 is controlled at the rated output.

In this embodiment, the operation mode of the solid oxide fuel cell 1 is set to a predetermined output mode in which the operation is controlled at a predetermined output exceeding the load power of the power load section 3 before the receiving point power reduction execution date and time, and the receiving point power is reduced. During the lowering execution period, the predetermined output mode is changed to the rated output mode in which the operation of the solid oxide fuel cell 1 is controlled at the rated output. In other words, before the date and time of execution of power reduction at the power receiving point assumed in advance, a certain amount of extra output of the solid oxide fuel cell 1 is secured, and in preparation for the necessary amount of power to be supplied to the power system 15, the power at the power receiving point In the lowering execution period, the output of the solid oxide fuel cell 1 is set to the rated output, which is the maximum output, to secure the required amount of power to be supplied to the power system 15 . As a result, it is possible to quickly and reliably respond to the receiving point power reduction command. Since the surplus power, which is the difference between the predetermined output mode and the load following mode, is supplied to the electric heater 9 different from the power load unit 3 until the power receiving point power reduction command date and time, stable power to the power load unit 3 Surplus power can be effectively used without wasting it while ensuring supply.

As a modification of this embodiment, when the predetermined output mode is changed to the rated output mode during the execution period of the power reduction at the power receiving point, if the requested power amount for the power reduction at the power receiving point is not reached by the execution date and time of the power reduction at the power receiving point, , power may be supplied (purchased) from the power system 15, or an operation to reduce the load power of the power load unit 3 may be temporarily performed.

[Other embodiments]
<1> In the above-described embodiment, the fuel cell device X includes the solid oxide fuel cell 1, but the fuel cell device X is a polymer electrolyte fuel cell (PEFC) or a phosphoric acid fuel cell (PAFC). Alternatively, a molten carbonate fuel cell (MCFC) may be provided.

<2> In the above embodiment, an example of control performed in the fuel cell system has been described with specific numerical values, but these numerical values are described for illustrative purposes and can be changed as appropriate.

It should be noted that the configurations disclosed in the above-described embodiments (including other embodiments, the same shall apply hereinafter) can be applied in combination with configurations disclosed in other embodiments unless there is a contradiction. Moreover, the embodiments disclosed in this specification are merely examples, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be used in a fuel cell system connected to a power system.

1: Solid oxide fuel cell (fuel cell)
2: Hot water storage tank 9: Electric heater (power consumption device)
15: Power system C: Operation control unit E: Heat exchanger G: Management device

Claims (5)

A fuel cell installed in each of a plurality of facilities and capable of outputting electric power, an operation control unit for controlling the operation of the fuel cell, and a management device capable of communicating between the plurality of fuel cells from outside the facility. and in a fuel cell system comprising
The fuel cell is configured to be able to supply the power generated by the operation to the power load unit and to supply the power generated by the operation to the power system,
The operation control unit controls the operation of the fuel cell in a load following mode that follows the load power of the power load unit,
The management device is configured to be capable of transmitting an output control command that determines the output power of the fuel cell to the operation control unit,
The operation control unit receives the output control command from the management device and controls the operation of the fuel cell at the rated output from the load following mode before the receiving point power reduction execution date and time for reducing the receiving point power of the facility. After changing to the rated output mode, surplus power, which is the difference between the rated output mode and the load following mode, is supplied to a power consumption device different from the power load unit in the load following mode until the power receiving point power reduction execution date and time. fuel cell system. 2. The fuel cell system according to claim 1, wherein the operation control unit increases the output of the fuel cell so as to enter the rated output mode at the power receiving point power reduction execution date and time. A fuel cell installed in each of a plurality of facilities and capable of outputting electric power, an operation control unit for controlling the operation of the fuel cell, and a management device capable of communicating between the plurality of fuel cells from outside the facility. and in a fuel cell system comprising
The fuel cell is configured to be able to supply the power generated by the operation to the power load unit and to supply the power generated by the operation to the power system,
The operation control unit controls the operation of the fuel cell in a rated output mode in which the rated output is obtained,
The management device is configured to be capable of transmitting an output control command that determines the output power of the fuel cell to the operation control unit,
The operation control unit is
Excess power exceeding the load power of the power load unit is supplied to a different power consumption device from the power load unit during a period other than a power receiving point power reduction execution period in which the power of the power receiving point of the facility is reduced in response to the output control command from the management device. supply to
When an adjusted surplus power exceeding the load power of the power load unit and the reverse flow power for supplying power to the power system is generated during the power receiving point power reduction execution period, the adjusted surplus power is supplied to the power consuming device. fuel cell system. A fuel cell installed in each of a plurality of facilities and capable of outputting electric power, an operation control unit for controlling the operation of the fuel cell, and a management device capable of communicating between the plurality of fuel cells from outside the facility. and in a fuel cell system comprising
The fuel cell is configured to be able to supply the power generated by the operation to the power load unit and to supply the power generated by the operation to the power system,
The operation control unit controls the operation of the fuel cell in a predetermined output mode in which a predetermined output exceeds the load power of the power load unit,
The management device is configured to be capable of transmitting an output control command that determines the output power of the fuel cell to the operation control unit,
The operation control unit is
Excess power exceeding the load power of the power load unit is supplied to a different power consumption device from the power load unit during a period other than a power receiving point power reduction execution period in which the power of the power receiving point of the facility is reduced in response to the output control command from the management device. supply to
A fuel cell system that changes from the predetermined output mode to a rated output mode in which the operation of the fuel cell is controlled at a rated output during the power receiving point power reduction execution period. 5. The power consuming device according to any one of claims 1 to 4, wherein the electric heater is arranged in a hot water circulation path between a heat exchanger through which combustion exhaust gas of the fuel cell flows and a hot water storage tank that stores hot water. A fuel cell system according to any one of the preceding paragraphs.

Images