JP7257905B2 - fuel cell system - Google Patents

Description

The present invention includes a fuel cell, a gas meter including a volumetric flow rate measuring unit for measuring the total flow rate of fuel supplied to the fuel cell and other fuel consuming equipment, and an abnormality determination unit,
The present invention relates to a fuel cell system in which the abnormality determination unit determines that there is no fuel leakage when the total flow rate is within a predetermined range around a set flow rate for a predetermined period of time.

As a conventional example of such a fuel cell system, an operation control unit that controls the operation of the fuel cell determines the accumulated time for supplying fuel to the fuel cell at a flow rate (for example, 50 L/h) corresponding to the set flow rate (pilot registration value). , If the set time (eg, 24 hours) is not reached in 29 days of the predetermined determination period (30 days), the flow rate (eg, 50 L / h) corresponding to the set flow rate (pilot registration value) fuel There is a configuration in which a fixed flow rate operation mode for supplying fuel cells is performed until the above-mentioned cumulative time reaches a set time (for example, 24 hours) (see, for example, Patent Document 1).

That is, in Patent Document 1, the operation of the fuel cell is continued by executing the fixed flow rate operation mode by utilizing the fact that the gas meter (fuel gauge) has an abnormality determination unit that functions as a pilot registration function. This is to prevent the gas meter from detecting an abnormal state of fuel leakage (gas leakage) as it is.

That is, the gas meter has a leakage detection function that issues an alarm and cuts off the supply of fuel (gas) when the fuel (gas) continues to flow for a predetermined period (for example, 30 days).
This leak detection function is designed to detect fuel (gas) leaks, for example, when a rubber pipe that supplies fuel (gas) or a fuel consuming device is damaged and a small amount of fuel (gas) continues to leak. It is the intended function.

If the fuel (gas) supply is interrupted by this leakage detection function, the fuel cell system is stopped, and the advantages obtained by continuously operating the fuel cell system are lost.
In addition, in order to cancel the alarm by the leak detection function or cancel the cutoff of the fuel supply, inspection by the gas supplier is often required. ), this release work is a heavy burden on the user.

Therefore, in Patent Document 1, even if fuel (gas) continues to flow in the gas meter, the total flow rate measured by the volumetric flow rate measuring unit is within a predetermined range centered on the set flow rate. When there is a predetermined time (for example, 1 hour) during a period (for example, 30 days), the fixed flow rate operation mode is executed in view of the fact that it has a pilot fire registration function (abnormality determination unit) that determines that there is no fuel leakage. By doing so, detection of fuel leakage (gas leakage) is prevented.

Incidentally, in Patent Document 1, when the fuel flow rate is near the predetermined range of the pilot ignition registration function during execution of the load following operation mode in which the operation is performed with the fuel flow rate (gas flow rate) that follows the power load, the fixed flow rate The fuel cell is configured to operate in the operation mode, and fuel is supplied at a flow rate (for example, 50 L/h) corresponding to the set flow rate (pilot registration value) for 29 days out of a predetermined determination period (30 days). is designed to lengthen the cumulative time supplied to the

Incidentally, Patent Document 1 describes that the amount of fuel (gas) supplied to the fuel cell is controlled by an operation control device comprising a computer by activating a control valve. Although the description of the measurement unit that performs measurement is omitted, in practice, a measurement unit that measures the amount of fuel (gas) supplied to the fuel cell is provided, and the amount of fuel (gas) supplied to the fuel cell is controlled. Conceivable.

JP 2012-209137 A

As a fuel cell, a reforming unit that steam-reforms the supplied fuel into a fuel gas for power generation, a cell stack that includes a plurality of solid oxide fuel cells, and an exhaust discharged from the cell stack BACKGROUND ART There is a so-called solid oxide fuel cell (SOFC) in which a combustor for combusting a fuel gas and an exhaust oxygen gas is housed in a container.

This solid oxide fuel cell (SOFC) uses the combustion heat of the combustion section to generate electricity while maintaining the reforming section and cell stack at high temperatures, and constitutes a highly efficient cogeneration system. is extremely effective for
However, once the operation of a solid oxide fuel cell (SOFC) is stopped, it takes a long time to bring the operation back to normal conditions, for example, to raise the temperature. , it is desired to perform continuous operation as much as possible.

By the way, in general, a fuel meter (gas meter) is provided with a volumetric flow rate measuring part to measure the total flow rate, whereas the flow rate of the fuel supplied to the solid oxide fuel cell is measured. As the measurement unit, a mass-type flow measurement unit is provided.
Therefore, the volume of the fuel (gas) expands or contracts due to the outside temperature, which fluctuates depending on the season and time of day. There is a possibility that it is different from the flow rate of fuel.
In addition, there is a possibility that the flow rate of fuel measured by the volumetric flow rate measuring unit and the flow rate of fuel measured by the mass type flow rate measuring unit may become different due to aged deterioration of the device.

Therefore, as in the fuel cell system described in Patent Document 1, by utilizing the fact that the fuel gauge (gas meter) has an abnormality determination section (pilot registration function), the flow rate corresponding to the set flow rate (pilot registration value) of fuel to be supplied to the fuel cell while the fuel is being measured by the mass flow measurement unit, and the fixed flow rate operation mode is executed to prevent fuel leakage (gas leakage) from being detected. Even if fuel is supplied to the fuel cell at a flow rate corresponding to the set flow rate (pilot registration value) while measuring the flow rate at There is a possibility that the cumulative time within the range does not exist for a predetermined time during the predetermined period, and a fuel leak (gas leak) may be detected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to detect fuel leakage by utilizing the ignition registration function of a gas meter while continuously operating a solid oxide fuel cell. The object of the present invention is to provide a fuel cell system capable of precisely avoiding the occurrence of the above and furthermore, capable of appropriately operating a solid oxide fuel cell while utilizing the pilot fire registration function of a gas meter.

A fuel cell system according to the present invention includes a fuel cell, and a gas meter having a volumetric flow rate measuring section for measuring the total flow rate of fuel supplied to the fuel cell and other fuel consuming equipment, and an abnormality determining section. ,
The abnormality determination unit determines that there is no fuel leakage when the total flow rate is within a predetermined range centered on the set flow rate for a predetermined time during a predetermined period. ,
The fuel cell includes a reforming unit that steam-reforms the supplied fuel into a fuel gas for power generation, a cell stack that includes a plurality of solid oxide fuel cells, and a discharge from the cell stack. The combustor for combusting the exhausted fuel gas and the exhausted oxygen gas is configured to be housed in a container,
A mass-type flow rate measuring unit for measuring the flow rate of fuel supplied to the fuel cell and an output adjusting unit for adjusting the output of the cell stack are provided,
An operation control unit that controls the operation of the fuel cell,
an abnormality avoidance mode in which a predetermined amount of fuel set by increasing or decreasing the set reference flow rate corresponding to the set flow rate is supplied to the fuel cell based on the detection result of the mass-type flow rate measuring unit; , during the predetermined period, it is configured to be executed for a mode execution time set longer than the predetermined time, and
When the abnormality avoidance mode is executed, the output adjustment unit is controlled so as to increase the output of the cell stack when the amount of fuel supplied to the fuel cell is large compared to when the amount of fuel is small. It is in.

That is, as a fuel cell, a reforming processing unit that steam-reforms the supplied fuel into a fuel gas for power generation, a cell stack that includes a plurality of solid oxide fuel cells, and a fuel that is discharged from the cell stack. Since it is equipped with a so-called solid oxide fuel cell in which a combustion unit for burning exhausted fuel gas and exhausted oxygen gas is stored in a container, power generation efficiency and heat recovery are improved. A highly efficient cogeneration system with excellent efficiency can be constructed.

In addition, the operation control unit executes the abnormality avoidance mode for supplying a predetermined amount of fuel to the solid oxide fuel cell for a mode execution time set longer than the predetermined time during the predetermined period. .
Then, by supplying a predetermined amount of fuel to the solid oxide fuel cell, if the total flow rate measured by the volumetric flow rate measuring unit is within a predetermined range centered on the set flow rate, an abnormality can be avoided. By executing the mode for a defined mode execution time longer than the predetermined time, it is possible to bring about a state in which the total flow rate is within the predetermined range for a predetermined time during the predetermined period. The determination unit determines that there is no fuel leakage.

Since the predetermined amount is set by increasing or decreasing the set reference flow rate corresponding to the set flow rate based on the setting change condition, the setting change condition may be changed, for example, by the outside temperature that varies depending on the season or time period. Even if the volume of the fuel expands or contracts, the flow rate measured by the volumetric flow rate measurement unit will be the set flow rate or will be close to the set flow rate. By setting conditions that can avoid the fuel flow rate measured by the volumetric flow rate measuring unit and the fuel flow rate measured by the mass type flow rate measuring unit from becoming different due to deterioration over time, etc. , can be set to a value such that the total flow rate measured by the volumetric flow rate measuring unit is within a predetermined range centering on the set flow rate.

As a result, while the solid oxide fuel cell is operated continuously, the abnormality avoidance mode is executed over the mode execution time, so that the total flow rate measured by the volumetric flow rate measuring unit is within a predetermined range. It is possible for the accumulated time within the range to exist for a predetermined time during the predetermined period, and as a result, the abnormality determination unit determines that there is no fuel leakage.

To explain the fluctuation of the outside temperature, for example, if the fuel is city gas, and the reference temperature is 20°C, if the temperature rises or falls by 20°C, the flow rate measured by the volumetric flow rate measuring unit and the mass flow rate The error with the flow rate measured by the measuring part is about 7%. Due to this error, the total flow rate measured by the volumetric flow rate measuring section despite the solid oxide fuel cell being supplied with the set flow rate while being measured by the mass type flow rate measuring section. does not fall within the predetermined range, and the abnormality determination unit may not determine that there is no fuel leakage.

In this characteristic configuration, as described above, by increasing or decreasing the predetermined amount based on the setting change condition, the predetermined amount is maintained even if the volume of the fuel expands or contracts due to the outside temperature that varies depending on the season or time zone. , the total flow rate measured by the volumetric flow rate measuring unit can be set to a value that is within a predetermined range centered on the set flow rate, so in the abnormality avoidance mode, the volumetric flow rate measuring unit measures A predetermined amount of fuel whose total flow rate is within a predetermined range around the set flow rate can be supplied to the solid oxide fuel cell while being measured by the mass-type flow rate measuring unit.

Moreover, in this characteristic configuration, when the abnormality avoidance mode is executed, the output adjustment unit is configured to increase the output (generated power) of the cell stack when the amount of fuel supplied to the fuel cell is large compared to when the amount of fuel is small. Therefore, even when the abnormality avoidance mode is executed, the solid oxide fuel cell can be operated while being maintained in an appropriate state.

In other words, when executing the abnormality avoidance mode, the output (generated power) of the cell stack is used to drive, for example, the auxiliary equipment of the fuel cell (fuel supply blower, air supply blower, etc.) regardless of the fluctuation of the predetermined amount. It is conceivable to maintain a constant value, such as setting to a value corresponding to an idling state in which power is supplied.

However, if the output (generated power) of the cell stack is maintained at a constant value when executing the abnormality avoidance mode, for example, when the predetermined amount is set to a large amount, the combustion part that burns in the container There is a risk that the solid oxide fuel cell will be damaged due to overheating of the cell stack and the reforming unit due to an excessive amount of combustion.

In this characteristic configuration, even when the abnormality avoidance mode is executed, the output current of the cell stack is increased when the amount of fuel supplied to the fuel cell is large compared to when the amount is small, so the abnormality avoidance mode is executed. Even in this case, the solid oxide fuel cell can be operated while being maintained in an appropriate state.

In short, according to the characteristic configuration of the fuel cell system of the present invention, even while the solid oxide fuel cell is operated continuously, it is possible to accurately detect fuel leakage using the ignition registration function of the gas meter. It is possible to properly operate the solid oxide fuel cell while avoiding this problem and using the pilot fire registration function of the gas meter.

A further characteristic configuration of the fuel cell system of the present invention is provided with an outside air temperature measuring unit for measuring the outside air temperature,
The setting change condition is such that the predetermined amount is set smaller as the outside air temperature increases.

That is, based on the outside temperature measured by the outside temperature measuring unit, the higher the outside temperature, the smaller the predetermined amount is set. Even if the volume of the fuel expands or contracts, the flow rate measured by the volumetric flow rate measuring unit can be accurately brought to the set flow rate or brought closer to the set flow rate.

In other words, the amount of expansion or contraction of the volume of the fuel fluctuates according to the fluctuation of the outside temperature. When the avoidance mode is executed, the flow rate measured by the volumetric flow rate measuring unit can be accurately adjusted to the set flow rate or brought closer to the set flow rate.

In short, according to a further characteristic configuration of the present invention, when executing the abnormality avoidance mode, by supplying a predetermined amount of fuel to the fuel cell, the flow rate measured by the volumetric flow rate measuring unit can be accurately measured. It can be at or close to the set flow rate.

A further characteristic configuration of the fuel cell system of the present invention is that the setting change condition is a condition that the predetermined amount is set smaller in summer than in winter based on the season.

That is, the predetermined amount is set based on the season so that it is smaller in summer than in winter, so when the abnormality avoidance mode is executed, the volume of the fuel expands or contracts depending on the outside temperature, which varies depending on the season. However, the flow rate measured by the volumetric flow rate measuring unit can be set to the set flow rate or brought closer to the set flow rate.

In other words, by setting the predetermined amount to be smaller in the summer than in the winter, in accordance with the fact that the outside air temperature is higher in the summer than in the winter, when the abnormality avoidance mode is executed, the volume The flow rate measured by the type flow rate measuring unit can be set to the set flow rate or brought closer to the set flow rate.

In addition, in order to change the predetermined amount based on the season, the predetermined amount can be changed using the calendar function provided in the operation control unit configured using a computer. In the configuration, the predetermined amount is set to be smaller in summer than in winter, and when the abnormality avoidance mode is executed, the flow rate measured by the volumetric flow rate measuring unit is set to the set flow rate. It is possible to approximate the flow rate.

In short, according to a further characteristic configuration of the fuel cell system of the present invention, when the abnormality avoidance mode is executed with a simple configuration, the flow rate measured by the volumetric flow rate measuring unit is set to the set flow rate or It can be close to the set flow rate.

A further characteristic configuration of the fuel cell system of the present invention is that the setting change condition sets a plurality of stages of the predetermined amount to be changed with the passage of time as the predetermined amount for winter, and The predetermined amount is a condition for setting a plurality of stages of the predetermined amount that are changed with the passage of time.

In other words, the outside temperature tends to be higher in the summer than in the winter. , the outside air temperature will fluctuate.

According to this characteristic configuration, as the predetermined amount for winter, a plurality of stages of predetermined amounts that change with the passage of time are set, and as the predetermined amount for summer, a plurality of stages that change with the passage of time are set. Since the fixed amount is set, when supplying the fuel cell with a predetermined amount that changes in multiple stages over time in summer or winter, it is measured by the volumetric flow rate measuring unit. The flow rate to be supplied can be set to the set flow rate or close to the set flow rate.

In other words, in summer or winter, even if the outside temperature fluctuates due to the difference in the date and time, when executing the abnormality avoidance mode, the flow rate measured by the volumetric flow rate measurement unit is appropriately set to the set flow rate. can approximate the flow rate.

In short, according to a further characteristic configuration of the fuel cell system of the present invention, when the abnormality avoidance mode is executed, the flow rate measured by the volumetric flow rate measuring unit is appropriately adjusted to the set flow rate or close to the set flow rate. be able to.

A further characteristic configuration of the fuel cell system of the present invention is that the setting change condition is a condition for setting the predetermined amount in multiple stages that is changed with the passage of time.

That is, by changing the predetermined amount in a plurality of steps with the passage of time, when the predetermined amount of any of the steps that change in the plurality of steps with the passage of time is supplied to the fuel cell, the volumetric flow rate measuring unit The flow rate measured in can be set to the set flow rate or brought closer to the set flow rate.

Therefore, with an extremely simple configuration in which the predetermined amount is changed in multiple stages with the passage of time, when the abnormality avoidance mode is executed, the flow rate measured by the volumetric flow rate measuring unit is set to the set flow rate or It can be close to the set flow rate.

In short, according to a further characteristic configuration of the fuel cell system of the present invention, when executing the abnormality avoidance mode, the flow rate measured by the volumetric flow rate measuring unit is set to the set flow rate with an extremely simple configuration. Or it can be brought close to the set flow rate.

1 is an overall configuration diagram of a fuel cell system; FIG. It is a figure which shows the relationship between a set flow volume and a predetermined range. It is a figure which shows the relationship between outside temperature and flow ratio. It is a figure which shows the relationship between time progress and flow rate in summer and winter. It is a figure which shows the relationship between predetermined amount and time progress. 4 is a flow chart showing the control operation of the operation control unit; 4 is a flow chart showing control operation of an abnormality determination unit;

Next, embodiments of the present invention will be described based on the drawings.
[Overall Configuration of Fuel Cell System]
As shown in FIG. 1, the fuel cell system includes a fuel cell device X, a fuel gauge Y that functions as a gas meter, and a heat treatment section Z that performs hot water supply processing and the like.

The fuel cell device X includes a solid oxide fuel cell (SOFC) 1 that supplies electric power generated during operation to a power load section 3 and exhaust heat generated during operation to a heat treatment section Z; An operation control device C (an example of an operation control section) that controls the operation of the fuel cell device X including the fuel cell 1, and an outside air temperature sensor T1 (an example of an outside air temperature measurement section) that measures the outside air temperature.
In addition to the power supplied from the solid oxide fuel cell 1, the power load unit 3 can consume power supplied from the commercial power supply 15 as described later.

The power generated by the solid oxide fuel cell 1 is supplied to a power converter 12 having an inverter. The power converter 12 converts the power generated by the solid oxide fuel cell 1 into the same voltage and frequency as the power received from the commercial power supply 15. By adjusting the output current of the cell stack ST provided in the fuel cell 1, it functions as an output adjustment section that adjusts the output (generated power) of the cell stack ST.
The operation control device C controls the operation of the power converter 12 .

The power conversion unit 12 is electrically connected to the power receiving power supply line 14 via the generated power supply line 13 . After the generated power from the solid oxide fuel cell 1 is converted by the power converter 12 , it is supplied to the power load section 3 via the generated power supply line 13 and the received power supply line 14 .
The power receiving power supply line 14 is connected to a commercial power source 15 . In other words, power is supplied to the power load unit 3 from at least one of the solid oxide fuel cell 1 and the commercial power source 15 .

A power load measuring unit 16 that measures the power load of the power load unit 3 is provided in the power receiving power supply line 14 , and the measurement result is transmitted to the operation control device C.
As one of the operation modes, the operation control device C detects the power supplied from the solid oxide fuel cell 1 to the power receiving power supply line 14 by the power load measuring unit 16 in order to avoid reverse power flow. control is performed to keep the power load slightly lower than the current load (load following operation mode). When reverse power flow is recognized, the power supplied from the solid oxide fuel cell 1 to the power receiving power supply line 14 may be the same as the power load detected by the power load measuring unit 16. .

In addition, the operation control device C sets the solid oxide fuel cell 1 to a rated output (a state in which the fuel flow rate supplied to the solid oxide fuel cell 1 is 120 to 130 L/h) as one of the operation modes. ) to operate (rated output operation mode).
Further, the operation control device C sets the solid oxide fuel cell 1 in an idling state (a state in which the fuel flow rate supplied to the solid oxide fuel cell 1 is 50 L/h or less) as one of the operation modes. (idling operation mode). The generated power output in this idling operation mode is used as electric power for driving auxiliary equipment of the fuel cell device X (such as an air blower 22 and a fuel blower B, which will be described later).

However, in the load following operation mode, the power load measured by the power load measuring unit 16 is the minimum power generation of the solid oxide fuel cell 1 (the minimum power generation supplied to the power receiving power supply line 14 by the power conversion unit 12). power), a surplus power occurs. Similarly, in the rated output operation mode, surplus power is also generated when the output power from the power conversion unit 12 is greater than the power load measured by the power load measurement unit 16 .
In such a case, if the reverse power flow to the commercial power supply 15 is possible, the surplus power may be supplied to the commercial power supply 15, but the reverse power flow to the commercial power supply 15 is permitted. If not, the surplus power is consumed by the electric heater 9 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 device C controls the operation of the operation switch 10 .

The heat load section 4 of the heat treatment section Z can consume heat supplied from the auxiliary heat source device 11 that generates heat by burning the fuel, in addition to the heat generated from the solid oxide fuel cell 1. .
The operation control device C is composed of hardware and software having an information processing function, an information storage function, an information communication function, and the like.

The fuel gauge Y is composed of fuel (gas) supplied to the solid oxide fuel cell 1 via a fuel flow path L1 (an example of a fuel supply path), an auxiliary heat source device 11, a gas stove GC, and the like. Total volume of fuel (gas) supplied to other fuel consuming equipment D via fuel flow path L6 (an example of fuel supply path) (an example of total flow rate, solid oxide fuel cell 1 and other fuel consumption A volumetric flowmeter Fb (an example of a volumetric flow rate measuring unit) for measuring the total value of the volumetric flow rate of fuel consumed by the device D (hereinafter simply referred to as "total volume") is provided.

The volumetric flowmeter Fb is a membrane gas meter that measures the amount of fuel used (total volume) from the number of times the movable membrane that separates the two measurement chambers operates, or measures the gas flow velocity with an ultrasonic sensor and measures the fuel flow rate. It consists of an ultrasonic gas meter that measures the amount used (total volume).
When the volumetric flowmeter Fb is configured by an ultrasonic gas meter, the apparatus can be made compact and the amount of fuel used can be measured instantaneously.

The fuel gauge Y includes an abnormality determination section H that performs a safety function to detect fuel leakage (gas leakage) based on the total volume of fuel measured by the volumetric flowmeter Fb.
As one of these safety functions, during a predetermined period of time (for example, 30 days), the cumulative time when the total volume measured by the volume flow meter Fb is a very small amount or less (total volume) is reduced for a predetermined time (for example, 1 hour), it is determined that there is a fuel leak (gas leak), and a leak detection function is provided to issue an alarm and cut off the supply of fuel (gas). By the way, when the cumulative time for which the flow rate (total volume) is very small or less reaches a predetermined time (for example, 1 hour), the cumulative time is reset assuming that there is no fuel leakage (gas leakage).

The fuel gauge Y has such a leakage detection function, and also has a pilot flame registration function as one of its safety functions.
As shown in FIG. 2, even if the accumulated flow rate (total volume) does not reach a predetermined time (for example, 1 hour) during a predetermined period (for example, 30 days), the pilot fire registration function During (for example, 30 days), the total volume measured by the volumetric flowmeter Fb is set within a range where the pilot fire can be registered. ) has reached a predetermined time (e.g., 1 hour), it determines that there is no fuel leakage (gas leakage), and there is no fuel leakage (gas leakage). If so, the accumulated time is reset, and if the accumulated time has not reached a predetermined time (for example, one hour), an alarm is issued and the supply of fuel (gas) is cut off.

In other words, when fuel (gas) is used continuously, by setting the pilot fire registration function and registering the set flow rate (pilot registration value), the leak detection function issues an alarm and the fuel (gas) supply can be deactivated.

[Details of Solid Oxide Fuel Cell]
The solid oxide fuel cell 1 includes a reforming unit K that steam-reforms the supplied fuel into a fuel gas (reformed gas) for power generation, and a plurality of solid oxide fuel cells S. A cell stack ST provided therein and a combustor 1c for burning exhausted fuel gas and exhausted oxygen gas as off-gases discharged from the cell stack ST are configured to be housed in a container 1A. The container 1A is preferably configured using a material having heat insulation properties.
Although illustration is omitted, the cell stack ST is electrically connected to the power converter 12 having an inverter.

The reforming unit K is supplied with a fuel (hydrocarbon-containing gas, for example, city gas 13A) and reforming water, and includes a vaporizer 1b for evaporating the supplied reforming water, and a reformer 1a for reforming to generate fuel gas (reformed gas with high hydrogen concentration).

The cell stack ST includes an anode 50 having a fuel passage (not shown) through which the fuel gas generated in the reformer 1a flows, and an air passage (not shown) through which oxygen (air) flows. ) are electrically connected in series. Although not shown, the fuel cell S is constructed in a solid oxide form with a solid electrolyte layer between the anode 50 and the cathode 60 . The fuel gas is supplied to the anode 50 by flowing the fuel gas through the fuel flow portion, and the oxygen is supplied to the cathode 60 by flowing the air through the air flow portion.
The cell stack ST is placed inside the container 1A in a state in which a plurality of fuel cells S are horizontally arranged with the fuel gas discharge port 50a of the fuel passage portion and the air discharge port 60a of the air passage portion facing upward. is set up.

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 plurality of fuel cells S are arranged above the gas manifold 1e in a state of being aligned as described above. ) are connected in communication.
Then, the fuel gas supplied to the gas manifold 1e is supplied to each of the fuel passages of the plurality of fuel cells S from the gas introduction port at the lower end, and the fuel gas flows downward to each fuel passage. It flows from the side to the upper side and is used for the power generation reaction. After being subjected to the power generation reaction, the discharged fuel gas is discharged as off-gas 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 flow path L5 is connected. An air filter 21, an air blower 22, and an air flow meter 23 are provided in the middle of the air supply flow path L5.
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 measurement result of the air flow meter 23 is transmitted to the operation control device C, and the operation control device C controls the operation of the air blower 22 .
The operation control device C controls the operation of the air blower 22 so that the flow rate per unit time of the air supplied into the container 1A reaches the target flow rate.

An air supply hole (not shown) that communicates the inside of the container 1A with the inside of the air circulation portion is provided in the vicinity of the lower end portion of the air circulation portion in each of the plurality of fuel cells S. The air in the container 1A is supplied through the air supply holes to the air circulation portions of the plurality of fuel cells S, and the air flows from the lower side to the upper side through the respective air circulation portions to generate power. subjected to reaction.
After being subjected to the power generation reaction, the exhaust air is discharged as off-gas from the air discharge port 60a at the upper end.

Above the cell stack ST, there is a combustion space for burning the discharged fuel gas containing hydrogen not used in the power generation reaction, which is discharged from the fuel gas discharge port 50a, and the exhaust air discharged from the air discharge port 60a. It is formed. An igniter 1d is also provided in this combustion space.
That is, the combustion space above the cell stack ST realizes a combustion section 1c that burns the off-gas from the cell stack ST.

In addition, a vaporizer 1b and a reformer 1a, which are integrally constructed, are provided above and adjacent to the combustion section 1c.
The operation control device C controls the operation of the igniter 1d. The combustion temperature sensor T4 measures the temperature of the combustion section 1c, and the measurement result is transmitted to the operation control device C. Then, it is used for determining whether or not the combustion in the combustion section 1c is properly performed.

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. That is, the exhaust part 80 is connected to the exhaust gas passage R through which the exhaust gas flows through the heat exchanger E. As shown in FIG.
A combustion catalyst unit 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 unit 80 to the outside.
The ambient temperature sensor T5 measures the temperature inside the container 1A, for example, the temperature on the side of the cell stack, and the measurement result is transmitted to the operation controller C.

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.

Fuel is also supplied to the carburetor 1b through the fuel flow path L1. A mass flow meter Fa (an example of a mass-type flow measuring unit) and a fuel blower B are provided in the middle of the fuel flow path L1. For the mass flowmeter Fa, for example, a thermal mass flowmeter that performs measurement using the thermal diffusion action of fuel is used.
Further, a desulfurizer 20 for removing sulfur compounds contained in fuel (for example, city gas, etc.) is provided in the fuel flow path L1 on the downstream side of the fuel blower B. As shown in FIG.
By operating the fuel blower B, the fuel flows through the fuel flow path L1, is desulfurized by the desulfurizer 20, and then flows into the carburetor 1b.

The mass flow meter Fa measures the flow rate per unit time of the fuel supplied to the carburetor 1b, and the measurement result is transmitted to the operation control device C. When the mass flowmeter Fa is a thermal mass flowmeter, the operation control device C refers to the stored value of the heat quantity of the supplied fuel to determine the mass flow rate of the fuel.
The operation control device C controls the operation of the fuel blower B and the operation of the opening/closing valve V1, which will be described later, so that the flow rate of fuel measured using the mass flow meter Fa reaches a target flow rate. In this way, the fuel blower B functions as a fuel flow rate adjusting section that adjusts the flow rate of fuel supplied to the reformer 1a per unit time.
As described above, in the vaporizer 1b, a mixed gas in which fuel and water vapor are mixed and whose supply amount per unit time is controlled by the operation control device C is generated. to the reformer 1a.

The reformer 1a steam reforms the 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 fuel is reformed by the catalytic action of this 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 reforming temperature sensor T3 measures the temperature of the reformer 1a (for example, the temperature of the reforming catalyst), and the measurement result is transmitted to the operation controller C. Then, it is used for determining whether or not the temperature of the reformer 1a is appropriate.

[Details of the heat treatment part]
The thermal processing section Z is provided with a closed hot water storage tank 2 . The hot water storage 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 in a state of thermal stratification.
Tap water is supplied to the lower portion of the hot water storage tank 2 through a water supply passage 17 . The water supply passage 17 is provided with a tap water temperature sensor T2 for measuring the tap water temperature.

That is, inside the hot water storage tank 2, low-temperature hot water is stored in the lower part and high-temperature hot water is stored in the upper part. The hot water stored in the hot water storage tank 2 circulates between the hot water storage tank 2 and the heat exchanger E through which the combustion exhaust gas of the solid oxide fuel cell 1 flows through the exhaust heat recovery path 6 . The flow of hot water in the exhaust heat recovery path 6 is performed by the exhaust heat recovery pump 7 .

The operation control device C controls the operation of the exhaust heat recovery pump 7 . For example, when the operation control device C starts the operation of the solid oxide fuel cell 1 and needs to recover the heat of the exhaust gas discharged from the solid oxide fuel cell 1, the exhaust heat recovery The low-temperature hot water stored in the lower part of the hot water storage tank 2 is caused to flow into the exhaust heat recovery path 6 by operating the pump 7 for the hot water. The low-temperature hot water flowing through the exhaust heat recovery path 6 recovers the heat of the exhaust gas discharged from the solid oxide fuel cell 1 (the hot water is heated by the exhaust heat of the solid oxide fuel cell 1). ), high temperature (for example, 60° C.) water flows into the upper part of the hot water storage tank 2 .

In the middle of the exhaust heat recovery path 6, a radiator 8 for releasing 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 is installed.
The operation control device C stops the operation of the radiator 8 when the temperature of the hot water flowing from the hot water storage tank 2 to the heat exchanger E is lower than the set upper limit temperature. On the other hand, when the temperature of the hot water flowing from the hot water storage tank 2 to the heat exchanger E is equal to or higher than the set upper limit temperature, the operation control device C causes the radiator 8 to release heat to lower the temperature of the hot water.
Joule heat generated by energizing the electric heater 9 is recovered by hot water flowing from the heat exchanger E to the hot water storage tank 2 .

The high-temperature hot water stored in the upper portion of the hot water storage tank 2 is supplied to the heat load section 4 through 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 operation control device C operates the auxiliary heat source device 11 to supply the hot water to the heat load unit 4 when the temperature of the hot water flowing out from the upper part of the hot water storage tank 2 is lower than the temperature of the hot water required by the heat load unit 4 . Control is performed so that the temperature of the hot water to be supplied becomes the desired temperature. The operation control device C controls the operation of the auxiliary heat source device 11 .

In the fuel flow path L1 for supplying fuel to the solid oxide fuel cell 1, an electromagnetic open/close valve V1 capable of blocking the flow of fuel is provided between the fuel gauge Y and the mass flow meter Fa. . A fuel passage L6 for supplying fuel to the auxiliary heat source device 11 is provided with an electromagnetic valve V2 capable of adjusting the amount of fuel supplied. An electromagnetic valve V3 capable of adjusting the amount of fuel supplied is provided in each fuel flow path L6 that supplies fuel to a plurality of other fuel consuming devices D such as a gas stove GC.

[About Abnormality Avoidance Mode]
As described above, the operation control device C is configured to be able to execute operation processing in a plurality of operation modes (load following operation mode, rated output operation mode, idling operation mode, etc.). Regardless of which operation mode is being executed, the operation control device C in this embodiment supplies the solid oxide fuel cell 1 via the fuel flow path L1 instead of the currently executed operation mode. An abnormality avoidance mode is forcibly executed in which a predetermined amount (for example, 45 L/h) of fuel is supplied based on the set flow rate (pilot registration value).
In this embodiment, the predetermined amount is set by increasing or decreasing the set reference flow rate corresponding to the set flow rate (pilot registration value) based on the setting change condition. By the way, the details of the setting change condition will be described later.

That is, in the abnormality avoidance mode, the operation control device C controls the operation of the fuel blower B so that the amount of fuel flowing through the fuel passage L1 becomes a predetermined amount. In setting the set flow rate (pilot registration value) corresponding to the set flow rate (pilot registration value), the user or the gas supplier can arbitrarily set it within the range that can be registered (50 L/h or less). Alternatively, it may be set by artificial intelligence obtained by machine learning based on the operating results of the solid oxide fuel cell 1 .
In the abnormality avoidance mode, the amount of air supplied is controlled in accordance with the control of the amount of fuel supplied. .

Further, the operation control device C is configured to execute the abnormality avoidance mode for a mode execution time set longer than a predetermined time (for example, 1 hour) within a predetermined period (for example, 30 days). ing.
The mode execution time can be set in various execution forms, such as, for example, setting 18 hours in the form of executing continuously for 6 hours every 10 days, or setting 15 hours in the form of executing 30 minutes every day. Various times can be set. In each day, the time period during which the abnormality avoidance mode is executed can be appropriately set to any one of morning, afternoon, nighttime, and the like.

In short, the mode execution time is centered around a set flow rate (pilot registration value) set within a range in which the total volume measured by the volumetric flowmeter Fb can be registered for a predetermined period (for example, 30 days). The accumulated time for the flow rate (total volume) to fall within a predetermined range (eg, ±5%) is set to a predetermined time (eg, 1 hour).
In addition, in setting the mode execution time, the user or the gas supplier may arbitrarily set the time. May be set.

Further, when executing the abnormality avoidance mode, the operation control device C increases the output (generated power) of the cell stack ST when the amount of fuel supplied to the fuel cell 1 is large compared to when it is small. It is configured to control 12.
That is, even if the amount of fuel supplied to the fuel cell 1 fluctuates in order to execute the abnormality avoidance mode, the amount of fuel supplied to the fuel cell 1 is kept constant or substantially the same in the combustion unit 1c. The power converter 12 is controlled so as to increase the output (generated power) of the cell stack ST when the amount of supply is large compared to when the amount of supply is small.

Specifically, for example, when the fuel supply amount to the fuel cell 1 is 1.00 L/min, the cell stack ST generated power is set to 0 W, and when the fuel supply amount is 1.10 L/min, the cell stack ST When the generated power is 10 W and the fuel supply rate is 1.20 L/min, the power conversion unit 12 adjusts the output (generated power) of the cell stack ST, such as by setting the generated power of the cell stack ST to 20 W. configured to be controlled.

[Details of the operation of the abnormality determination part]
When pilot fire registration is set, the abnormality determination unit H of the fuel gauge Y determines that the total volume of fuel measured by the volume flow meter Fb is centered on the set flow rate (pilot registration value, for example, 45 L/h). When the accumulated time within a predetermined range (for example, 45 L/h±5%) does not satisfy the condition that the predetermined time (for example, 1 hour) is longer than the predetermined period (for example, 30 days), the fuel flow path L1 , L6 of the fuel supplied through L6, and issues a fuel leak (gas leak) alarm, and closes the cutoff valve inside the fuel gauge Y. Cut off the fuel supply.

Further, the abnormality determination unit H determines that the cumulative time during which the total volume of fuel measured by the volumetric flow meter Fb is within a predetermined range (eg, 45 L/h±5%) is a predetermined time during a predetermined period (eg, 30 days). (For example, 1 hour) or more is satisfied, it is determined that there is no fuel leakage (gas leakage) of the fuel supplied through the fuel flow paths L1 and L6, and the accumulated time is reset. Then, execution of abnormality determination is stopped until the next predetermined period.

[Details of setting change conditions]
In judging the fuel leakage (gas leakage) described above, since the volumetric flow rate of the fuel fluctuates according to the temperature change, the total volume measured by the volumetric flowmeter Fb and the mass flow rate measured by the mass flowmeter Fa are different. There is a risk that they will not match.
For example, if the fuel is city gas and the reference temperature is 20°C, the error between the volumetric flow rate and the mass flow rate will be about 7% if the temperature fluctuates by 20°C. Due to this error, even if fuel is supplied to the solid oxide fuel cell 1 at a set reference flow rate (for example, 45 L/h) corresponding to the set flow rate (pilot registration value) while being measured by the mass flow meter Fa, The total volume measured by the volume flow meter Fb does not fall within a predetermined range (for example, 45 L/h ±5%), and the abnormality determination unit H erroneously determines that there is an abnormality in which fuel leakage (gas leakage) has occurred. There is a risk of judgment.

That is, as the outside air temperature rises, the fuel expands, the volumetric flow rate increases, and the measured value of the volumetric flowmeter Fb increases. If the amount of fuel supplied to the fuel cell 1 is, for example, 45 L/h, the measured value of the volumetric flowmeter Fb may be, for example, 48 L/h. As a result, even if the amount of fuel supplied to the solid oxide fuel cell 1 is controlled at 45 L/h, the total volume of the fuel measured by the volumetric flowmeter Fb does not fall within the predetermined range (45 L/h±5%). Therefore, there is a possibility that the abnormality determination unit H may erroneously determine that there is an abnormality in which fuel leakage (gas leakage) has occurred.

Therefore, in the abnormality avoidance mode, the operation control device C increases or decreases the set reference flow rate (for example, 45 L/h) corresponding to the set flow rate (pilot registration value) based on the setting change condition to set a predetermined amount. A predetermined amount of fuel is supplied to the solid oxide fuel cell 1 while being measured by a mass flow meter Fa.
In the following description, the setting change condition is set with the outside air temperature of 20° C. as the reference state, in other words, with 20° C. as the reference temperature of the outside air temperature. , a temperature other than 20° C. can be set as the reference temperature.
In addition, when setting the set flow rate (pilot registration value), the operation control device C increases or decreases the set reference flow rate (for example, 45 L/h) based on the setting change condition based on the outside temperature. A predetermined amount will be supplied.

As shown in FIG. 3, as a setting change condition, the flow rate ratio for changing the set reference flow rate (for example, 45 L/h) corresponding to the set flow rate corresponds to the change in the outside temperature, with the outside temperature being 20°C as the standard. is set as That is, it is possible to set (determine) the predetermined amount for each temperature by multiplying the set reference flow rate (for example, 45 L/h) and the flow rate ratio according to the outside air temperature.
Note that the relationship between the outside air temperature and the flow rate ratio shown in FIG. 3 is set based on the error between the volumetric flow rate and the mass flow rate for each temperature according to the composition of the fuel.

Therefore, as the outside air temperature measured by the outside air temperature sensor T1 becomes higher than 20°C, the operation control device C controls the solid oxide fuel cell 1 based on the flow rate ratio (ratio to the gas flow rate at the reference temperature of 20°C). The predetermined amount of fuel to be supplied is set to be small, and the lower the outside air temperature measured by the outside air temperature sensor T1 is below 20 ° C., the more solid fuel is supplied based on the flow rate ratio (ratio to the gas flow rate at the reference temperature of 20 ° C.). The predetermined amount of fuel to be supplied to the oxide fuel cell 1 is set to be large.

[Details of control operation]
FIG. 6 shows an example of the control operation executed by the operation control device C. As shown in FIG.
The operation control device C selects one of a plurality of operation modes (load following operation mode, rated output operation mode, idling operation mode, etc.) when an operation command is issued by an operation command unit (not shown). , a normal operation process for operating the solid oxide fuel cell 1 is executed (#1).

Next, the operation control device C determines whether or not it is time to shift to the abnormality avoidance mode (#2). That is, if the mode execution time is set to 18 hours, for example, in a form in which the mode is executed continuously for 6 hours every 10 days, it is determined whether or not the time period corresponds to 6 hours every 10 days. Alternatively, if the mode execution time is set to 15 hours, for example, in the form of execution for 30 minutes every day, it is determined whether or not the time period corresponds to 30 minutes every day.

If it is determined in the process of #2 that it is not the timing to shift to the abnormality avoidance mode, the normal operation process of #1 is continued.
When it is determined in the process of #2 that it is time to shift to the abnormality avoidance mode, the operation control device C executes the abnormality avoidance mode.
Specifically, first, the predetermined amount supplied to the solid oxide fuel cell 1 through the fuel flow path L1 is increased or decreased based on the set reference flow rate corresponding to the set flow rate (pilot registration value) based on the set change condition. The target is set by changing and maintaining the same or substantially the same state of the combustion amount in the combustion section 1c as the output (power generation output) of the solid oxide cell stack ST according to the set predetermined amount. Set the output (#3).

Next, the operation control device C controls the operation of the fuel blower B so that the measured value of the mass flow meter Fa becomes a target predetermined amount based on the measurement result of the mass flow meter Fa (#4), and then Then, the power converter 12 is controlled so that the output (generated power output) of the solid oxide cell stack ST becomes the target output (#5). After that, the process proceeds to #2.

FIG. 7 shows an example of the abnormality determination process executed by the abnormality determination section H of the fuel gauge Y. As shown in FIG.
The abnormality determination unit H determines whether or not the total volume measured by the volume flow meter Fb of the fuel gauge Y is within a predetermined range (45 L/h±5%) centered on the set flow rate (pilot registration value). Judgment is made (#11), and if the total volume is within a predetermined range (45 L/h±5%), a process of adding the accumulated time is executed (#12).

Next, it is determined whether or not the accumulated time during which the total volume is within a predetermined range (45 L/h±5%) is longer than or equal to a predetermined time (1 hour) (#13).
When the accumulated time is equal to or longer than the predetermined time (one hour), the accumulated time is reset (zeroed) (#14), and then waited until the next predetermined period (#15). When the period comes, the process moves to #11.

In the process of #11, it was determined that the total volume was not within the predetermined range (45 L / h ± 5%), or in the process of #13, it was determined that the cumulative time was less than the predetermined time (1 hour). In this case, it is determined whether or not 30 days have passed (whether or not a predetermined period has passed) (#16), and if 30 days have not passed, the process proceeds to #11. Become.

In the process of #16, when it is determined that 30 days have passed (predetermined period has passed), a fuel leak (gas leak) alarm is issued and the cutoff valve inside the fuel gauge Y is closed. An alarm process is executed to cut off the supply of fuel (#17).
By the way, when the #17 alarm processing is performed, the user will take the necessary measures to cancel the alarm and cancel the cutoff of the fuel supply, but the necessary measures are well known. Therefore, detailed description is omitted in this embodiment.

Thus, in this embodiment, the operation control device C executes the abnormality avoidance mode in which a predetermined amount of fuel is supplied to the solid oxide fuel cell 1 regardless of which operation mode is being executed. .
Since this abnormality avoidance mode supplies a predetermined amount of fuel to the solid oxide fuel cell 1, the total volume of fuel measured by the fuel gauge Y is becomes within a predetermined range centered on the set flow rate (pilot registration value), the abnormality determination unit H of the fuel gauge Y issues a fuel leakage (gas leakage) alarm, and the shutoff valve inside the fuel gauge Y is closed. Execution of an alarm procedure that closes and cuts off the supply of fuel is avoided.

That is, according to the present embodiment, while the solid oxide fuel cell 1 continues to generate power under normal operation, the abnormality avoidance mode is forcibly executed in a set time period, and the fuel Since the predetermined amount is set so that the total volume of the fuel measured by the volume flow meter Fb of the meter Y is within the predetermined range, the fuel flow can be maintained while the operation of the solid oxide fuel cell 1 is continued. It is possible to provide a fuel cell system that can avoid unnecessary detection of fuel leakage (gas leakage) of fuel supplied through paths L1 and L6.

Moreover, when the abnormality avoidance mode is executed, when the amount of fuel supplied to the fuel cell 1 is large, the output (generated power) of the cell stack ST is increased more than when the amount of fuel supplied to the fuel cell 1 is small. It is possible to operate the solid oxide fuel cell 1 while maintaining it in an appropriate state while avoiding troubles such as overheating and damage of the processing unit K.

[Other setting change conditions]
Next, another form of the setting change condition will be exemplified.
When the reference temperature is 20°C, the temperature difference at which the total volume of fuel (city gas) does not fall within a predetermined range (for example, 45 L/h ±5%) is approximately ±15°C or more. can be set as a condition that the predetermined amount is set smaller in the summer than in the winter.

That is, the operation control device C may set a predetermined amount for each season according to an internally managed calendar.
For example, there are two seasons: October to March (winter), when the temperature is estimated to be generally lower than the standard temperature (20°C), and April to September (summer), which is estimated to be generally higher than the standard temperature (20°C). A year is divided into , and a virtual reference temperature is set at ± 10 ° C. for each of winter and summer, and for each virtual reference temperature, a set reference flow rate corresponding to the set flow rate (for example, 45 L / h) Set the flow ratio to change the For example, the summer flow rate ratio is set to 0.9, and the winter flow rate ratio is set to 1.03, for example.

Then, a predetermined amount is set based on the error between the volume flow rate and the mass flow rate corresponding to the difference between the virtual reference temperature and the reference temperature. That is, in summer, the set reference flow rate (eg, 45 L/h) is multiplied by a flow rate (eg, 0.9) smaller than 1 (eg, 45 L/h × 0.97), and in winter, a flow rate greater than 1 ( For example, 1.03) is multiplied by the setting reference flow rate (eg, 45 L/h) (eg, 45 L/h×1.03) to set the predetermined amount corresponding to summer and winter.

In this way, if the predetermined amount is set based on the season, the predetermined amount is set smaller than the set reference flow rate (for example, 45 L/h) in consideration of the volume expansion of the fuel in the summer, and the volume of the fuel is reduced in the winter. In consideration of the above, it is possible to operate such that the predetermined amount is set larger than the set reference flow rate (for example, 45 L/h).

In this way, when determining the flow ratio to be multiplied by the set reference flow rate (for example, 45 L / h) for each of winter and summer, as shown in FIG. A plurality of stages of flow rate ratios may be determined.
In other words, the setting change condition is a predetermined amount for the winter season, which is a predetermined amount that varies with the passage of time, and a predetermined amount for the summer season, which is a predetermined amount that is varied with the passage of time. It may also be used as a condition for setting quantification.

FIG. 4 exemplifies three stages of flow rate ratios as flow rate ratios in summer and winter, and exemplifies a form in which a state of supplying a predetermined amount of fuel set at each flow rate ratio is maintained for one hour.
That is, in summer, the predetermined amount is set to 45 L/h×0.945, 45 L/h×0.97, and 45 L/h×0.995, and in winter, the predetermined amount is set to 45 L/h×1. .005, 45 L/h x 1.03, 45 L/h x 1.055 are set.
Then, the state of supplying the set predetermined amount of fuel is maintained for each hour (switched every hour).

In this way, when setting a plurality of stages of predetermined amounts that change with the lapse of time as the predetermined amount for winter and the predetermined amount for summer, the amount of fuel to be supplied at each of the predetermined amounts to be changed is set. , During a predetermined period (for example, 30 days), the total volume measured by the volumetric flowmeter Fb is set within a range in which pilot fire registration is possible. A predetermined range (for example, ±5%), the accumulated time is set to a predetermined time (for example, 1 hour).

Therefore, by setting a plurality of steps of predetermined amounts that change over time as the predetermined amount for winter and the predetermined amount for summer, one predetermined amount is set as the predetermined amount for winter and the predetermined amount for summer. is set, the flow rate measured by the volume flow meter Fb is appropriately set to the set flow rate when the abnormality avoidance mode is executed even if the outside temperature fluctuates due to the difference in date and time. can approximate the flow rate.

In addition, when changing the predetermined amount in multiple stages with the passage of time, it may be changed continuously. The predetermined amount may be changed.

The above-described setting change conditions have exemplified the case where the predetermined amount is changed in consideration of the change in the outside air temperature between winter and summer, but as shown in FIG. You may make it change.
In other words, the setting change condition may be a condition for setting a plurality of stages of predetermined amounts that are changed with the lapse of time.

To explain, in FIG. 5, the predetermined amount is the same value as the set reference flow rate (for example, 45 L / h), the value obtained by multiplying the set reference flow rate (for example, 45 L / h) by 1.08, the set reference flow rate (for example, 45 L /h) multiplied by 0.92, and the state of supplying the set predetermined amount of fuel is maintained for each hour (switched every hour).
A state in which the predetermined amount is set to the same value as the set reference flow rate (for example, 45 L/h) corresponds to an intermediate period such as spring and autumn, and the predetermined amount is set to the set reference flow rate (for example, 45 L/h) by 1. The state where the value is multiplied by 0.08 corresponds to winter when the outside air temperature is low, and the state where the predetermined amount is the value where the set reference flow rate (for example, 45 L/h) is multiplied by 0.92 is the state where the outside air temperature is low. It is suitable for the hot summer season.

In addition, when setting a plurality of stages of predetermined amounts that change with the passage of time as the predetermined amount, the time for supplying fuel at each of the predetermined amounts to be changed is set for a predetermined period (for example, 30 days). , The flow rate (total volume) in a predetermined range (for example, ±5%) centered on the set flow rate (pilot registration value) set within the range where the total volume measured by the volume flow meter Fb can be registered. is set to a time that can reach a predetermined time (for example, 1 hour).

Therefore, by setting a plurality of stages of predetermined amounts that change with the passage of time as the predetermined amount, even with a simple configuration, even if the outside temperature fluctuates due to seasonal changes or differences in the date and time, an abnormality can be detected. When executing the avoidance mode, the flow rate measured by the volumetric flowmeter Fb can be appropriately brought to the set flow rate or brought closer to the set flow rate.

[Another embodiment]
<1>
As shown in FIG. 1, the fuel gauge Y is a smart meter equipped with a communication interface (communication mechanism) provided in the operation control device C and a communication unit I (communication mechanism) capable of transmitting and receiving various data by wire or wirelessly. may be configured. In this case, the abnormality determination unit H detects the abnormality avoidance mode via the communication unit I. Thus, if a communication mechanism is provided between the fuel cell device X and the fuel gauge Y, it becomes possible to acquire the flow rate information of the fuel cell device X with the fuel gauge Y, and the abnormality avoidance mode can be detected in real time. . As a result, the fuel gauge Y causes the abnormality determination section H to function when the fuel cell device X is in the abnormality avoidance mode, thereby more reliably preventing fuel leakage (gas leakage) of the fuel supplied through the fuel flow paths L1 and L6. can be detected.

<2>
The operation control device C acquires the determination result by the abnormality determination unit H via the communication mechanism, and the operation control device C receives a predetermined time (for example, 1 hour) or more during a predetermined period (for example, 30 days). The anomaly avoidance mode may be canceled when a positive result that satisfies the conditions is obtained. As in the present embodiment, if the abnormality avoidance mode of the fuel cell device X is canceled when a positive result that satisfies a predetermined condition is acquired, normal operation is possible from the time of cancellation until the next determination, and fuel Efficient operation of the battery device X can be realized.

<3>
In the above embodiment, examples of control performed in the fuel cell system have been described with specific numerical values, but these numerical values are 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 is applicable to fuel cell systems having solid oxide fuel cells.

1: Solid oxide fuel cell 1A: Container 1c: Combustion unit 12: Output control unit C: Operation control unit D: Other fuel consumption equipment Fa: Mass flow rate measurement unit Fb: Volumetric flow rate measurement unit H: Abnormal Determination unit K: reforming unit S: fuel cell ST: cell stack T1: outside temperature measurement unit Y: fuel gauge

Claims (5)

A gas meter comprising a fuel cell, a volumetric flow rate measuring unit for measuring the total flow rate of fuel supplied to the fuel cell and other fuel consuming devices, and an abnormality determining unit,
The fuel cell system, wherein the abnormality determination unit determines that there is no fuel leakage when the total flow rate is within a predetermined range centered on a set flow rate for a predetermined period of time during a predetermined period,
The fuel cell includes a reforming unit that steam-reforms the supplied fuel into a fuel gas for power generation, a cell stack that includes a plurality of solid oxide fuel cells, and a discharge from the cell stack. The combustor for combusting the exhausted fuel gas and the exhausted oxygen gas is configured to be housed in a container,
A mass-type flow rate measuring unit for measuring the flow rate of fuel supplied to the fuel cell and an output adjusting unit for adjusting the output of the cell stack are provided,
An operation control unit that controls the operation of the fuel cell,
an abnormality avoidance mode in which a predetermined amount of fuel set by increasing or decreasing the set reference flow rate corresponding to the set flow rate is supplied to the fuel cell based on the detection result of the mass-type flow rate measuring unit; , during the predetermined period, it is configured to be executed for a mode execution time set longer than the predetermined time, and
The fuel configured to control the output adjustment unit so as to increase the output of the cell stack when the amount of fuel supplied to the fuel cell is large when executing the abnormality avoidance mode, compared to when the amount of fuel is small. battery system. An outside temperature measurement unit is provided to measure the outside temperature,
2. The fuel cell system according to claim 1, wherein the setting change condition is such that the predetermined amount is set smaller as the outside air temperature rises. 2. The fuel cell system according to claim 1, wherein the setting change condition is a condition that the predetermined amount is set smaller in summer than in winter based on the season. In the setting change condition, the predetermined amount for winter is set to a plurality of stages that change with time, and the predetermined amount for summer is set to a plurality of stages that change with time. 4. The fuel cell system according to claim 3, wherein the condition for setting the predetermined amount of is. 2. The fuel cell system according to claim 1, wherein said setting change condition is a condition for setting said predetermined amount to be changed in a plurality of steps over time.

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