JP7427567B2 - Fuel cell system and method of operating the fuel cell system - Google Patents

Description

The present invention relates to a fuel cell system and a method of operating the fuel cell system.

Gas microcomputer meters, which are usually installed in pipes that supply gas to general households, have the main monitoring functions of monitoring abnormal gas outflows, seismic sensing, pressure monitoring, and long-term use monitoring, as well as gas pipe leakage (particularly It is equipped with a safety function (hereinafter referred to as "minor leak detection function") that detects small leaks.

The micro leak detection function issues an alarm (blinking of an alarm lamp, etc.) when gas supply continues for a certain period of time, for example, 30 days (when the alarm counter exceeds a threshold value). The definition of "continuous" is, for example, that gas is flowing without an interval of 20 minutes or more. In other words, a flow interruption of less than 20 minutes (eg, 19 minutes) is recognized as "continuation."

Here, unlike other gas consuming devices, a fuel cell system has a normal specification that it continues to consume gas for the purpose of generating electricity.

For this reason, in fuel cell systems installed in gas piping equipment equipped with microcomputer meters, a certain period of power generation suspension should be established before 30 days have passed to prevent the above-mentioned minute leakage detection function from working. (See Patent Document 1).

However, in a fuel cell system, when power generation is stopped, the number of startups and stops increases, which may reduce the durability of the device. Therefore, Patent Document 2 focuses on the pilot flame registration function of the gas microcomputer meter, and when the continuous supply of gas at a predetermined fixed flow rate does not reach a reference time, continuous operation is performed in a predetermined fixed flow rate operation mode. .

Japanese Patent Application Publication No. 2005-353292 Patent No. 5580237

Incidentally, in a fuel cell system, the flow rate of gas used for operation may be controlled at a normal flow rate. On the other hand, the gas flow rate measured by the gas microcomputer meter is the actual volumetric flow rate. When the gas flow rate (actual volumetric flow rate) measured by the gas microcomputer meter changes due to changes in the outside air (outside temperature, outside pressure), the difference between the gas flow rate and the gas flow rate controlled by the fuel cell system becomes large, and a spark is registered. It is also possible that the flow rate is not within the range and the micro leak detection function is activated.

Patent Document 2 does not describe how to set the fixed flow rate range. Further, there is no mention of the case where the fixed flow rate range is controlled by the normal flow rate. In Patent Document 2, even if the engine is operated within a fixed flow rate range, it is not assumed that the flow rate does not fall within the registered pilot flow rate.

An object of the present invention is to avoid abnormality determination of the micro-leakage detection function by using the spark registration function of the gas microcomputer meter.

The fuel cell system according to claim 1 of the present invention includes a fuel cell unit that is operated using gas that has passed through a gas microcomputer meter, and in which the gas flow rate used for power generation operation is controlled at a normal flow rate; a correction unit that corrects the pilot registered flow rate registered in the meter to a pilot operation flow rate that approaches a normal flow rate based on at least one of the temperature inside the fuel cell unit, the outside temperature, the outside pressure, the gas temperature, and the gas pressure; , an igniter response operation switching unit that switches the operation of the fuel cell unit to an ignition response operation operated at the pilot ignition operation flow rate at the time of determination during a predetermined minute leakage detection determination period; and a predetermined continuous gas detection unit. and a pilot fire operation maintenance unit that continues the pilot fire response operation for a period of time.

A fuel cell system according to a first aspect of the present invention includes a fuel cell unit, a correction section, a pilot fire compatible operation switching section, and a pilot fire operation maintenance section. The fuel cell unit is operated using gas passed through a gas microcomputer meter, and the gas flow rate used for power generation operation is controlled at a normal flow rate. The correction unit adjusts the registered pilot flow rate registered in advance in the gas microcomputer meter to a pilot pilot operation that approaches a normal conversion value based on at least one of the temperature inside the fuel cell unit, the outside temperature, the outside pressure, the gas temperature, and the gas pressure. Correct to flow rate. Thereby, the normal flow rate controlled by the fuel cell unit can be corrected to a value (pilot operation flow rate) corresponding to the actual volumetric flow rate of gas that changes depending on outside temperature, outside pressure, gas temperature, and gas pressure.

The pilot fire compatible operation switching unit switches the operation of the fuel cell unit to the pilot fire compatible operation in which the fuel cell unit is operated at the pilot fire operating flow rate at the time of determination during a predetermined minute leakage detection determination period. This makes it possible to keep the gas flow rate via the gas microcomputer meter within the pre-registered pilot register flow rate while continuing to operate the fuel cell unit in response to at least one of the outside temperature and outside pressure. can.

The pilot fire operation maintenance unit continues the pilot fire response operation for a predetermined continuous gas detection time. Normally, when gas is supplied through a gas microcomputer meter that has a micro-leakage detection/judgment function, if the operation continues for a predetermined period of time within the pre-registered pilot flow rate range, the micro-leakage detection/judgment function is activated. warnings can be avoided. Therefore, if pilot fire response operation continues during the continuous gas detection time, the gas microcomputer meter will determine that gas has been used continuously within the range of pilot fire registration, thereby avoiding the abnormality determination of the micro leak detection function. can do.

The fuel cell system according to claim 1 , wherein the pilot fire operation maintenance unit includes a continuous pilot fire operation determination unit that determines whether or not the pilot fire response operation is maintained during the continuous gas detection time; The fuel cell unit further includes a load following operation switching section that switches the fuel cell unit to load following operation according to the electric power load when the judgment by the determining section is affirmative.

In the fuel cell system according to the first aspect , the pilot operation maintenance section includes a continuous pilot operation determination section and a load following operation switching section. The continuous pilot operation determination section determines whether pilot operation corresponding to the pilot fire has been maintained during the continuous gas detection time, and if the determination is affirmative, the load following operation switching section switches the fuel cell unit to the electric power load. Switch to load following operation accordingly.

This allows the fuel cell system to return to normal operation without causing an alarm on the gas microcomputer meter.

In the fuel cell system according to a second aspect of the present invention , the pilot registration flow rate is a gas flow rate corresponding to a base power generation maintenance output of the fuel cell unit.

According to the fuel cell system according to claim 2 , gas consumption is reduced while maintaining the base power generation of the fuel cell unit, so that the actual gas consumption flow rate and the gas flow rate used for power generation operation controlled by the normal flow rate are The error can be reduced.

In the fuel cell system according to claim 3 , during the pilot spark response operation, a plurality of different pilot spark adjustments are performed in which the pilot spark operation flow rate is corrected by an adjustment value for a stage continuous time longer than a continuous judgment time of the gas microcomputer meter. Continuous operation at each flow rate.

According to the fuel cell system according to claim 3 , even if there is an error due to instrumental error of the gas microcomputer meter or the fuel cell unit, by operating at a plurality of different pilot adjustment flow rates in which the pilot operation flow rate is corrected by the adjustment value, It is possible to operate within the range of the pilot flame registered flow rate.

The method for operating a fuel cell system according to claim 4 is a method for operating a fuel cell system in which the fuel cell system is operated using gas passed through a gas microcomputer meter, and the gas flow rate used for power generation operation is controlled at a normal flow rate. , the pilot registered flow rate registered in the gas microcomputer meter in advance is changed to a pilot operating flow rate that approaches a normal flow rate based on at least one of the temperature inside the fuel cell unit, the outside temperature, the outside pressure, the gas temperature, and the gas pressure. Then, during a predetermined minute leakage detection determination period, the fuel cell unit continues to operate at the pilot fire operation flow rate for a predetermined continuous gas detection time.

The operating method of a fuel cell system according to claim 4 is a method for controlling a pilot registered flow rate registered in advance in a gas microcomputer meter by at least one of the temperature inside the fuel cell unit, the outside temperature, the outside pressure, the gas temperature, and the gas pressure. Based on this, the pilot operation flow rate is corrected to approach the normal equivalent value. Thereby, the normal flow rate used in the fuel cell unit can be corrected so that the actual gas volumetric flow rate, which varies depending on outside temperature, outside pressure, gas temperature, and gas pressure, becomes the same.

Further, during the predetermined minute leakage detection determination period, the pilot fire response operation operated at the pilot fire operation flow rate is continued for a predetermined continuous gas detection time. Thereby, the gas flow rate via the gas microcomputer meter can be kept within the range of the pre-registered pilot flame registration flow rate while continuing the operation of the fuel cell unit in accordance with the outside temperature and outside pressure. Normally, when gas is supplied through a gas microcomputer meter that has a micro-leakage detection/judgment function, if the operation continues for a predetermined period of time within the pre-registered pilot flow rate range, the micro-leakage detection/judgment function is activated. warnings can be avoided. Therefore, if pilot fire response operation continues during the continuous gas detection time, the gas microcomputer meter will determine that gas has been used continuously within the range of pilot fire registration, thereby avoiding the abnormality determination of the micro leak detection function. can do.

In the method for operating a fuel cell system according to a fourth aspect of the invention , after the pilot flame response operation is maintained during the continuous gas detection time, the fuel cell unit is switched to a load following operation according to the electric power load.

According to the method for operating a fuel cell system according to the fourth aspect , it is possible to avoid the alarm from the gas microcomputer meter and return the fuel cell system to normal operation.

In the fuel cell system operating method according to claim 5 , the pilot registration flow rate is a gas flow rate corresponding to a base power generation maintenance output of the fuel cell unit.

According to the operating method of a fuel cell system according to claim 5 , gas consumption is reduced while maintaining the base power generation of the fuel cell unit, so that the gas used for power generation operation is controlled by the actual gas consumption flow rate and the normal flow rate. The error with the flow rate can be reduced.

The method for operating a fuel cell system according to claim 6 provides a method of operating a fuel cell system in which, during the pilot operation, the pilot operation flow rate is corrected by an adjustment value during a continuous stage time longer than a continuous judgment time of the gas microcomputer meter. Continuous operation is performed at different pilot flame adjustment flow rates.

According to the fuel cell system according to claim 6 , even if there is an error due to instrumental error of the gas microcomputer meter or the fuel cell unit, by operating at a plurality of different pilot adjustment flow rates in which the pilot operation flow rate is corrected by the adjustment value, It is possible to operate within the range of the pilot flame registered flow rate.

According to the present invention, it is possible to avoid abnormality determination of the micro leak detection function by using the spark registration function of the microcomputer meter.

1 is a schematic diagram of a fuel cell system according to a first embodiment. FIG. 2 is a block diagram showing the configuration of a controller according to the first embodiment. It is a graph showing the relationship between the output of the fuel cell system and the amount of gas consumed at each outside temperature. FIG. 2 is a front view of the operation remote control according to the first embodiment. FIG. 2 is a flowchart of pilot fire response operation processing according to the first embodiment. FIG. 7 is a flowchart of correction processing according to the first embodiment. FIG. 2 is a schematic diagram of a fuel cell system according to a modification of the first embodiment. It is a flow chart of fluctuating operation processing corresponding to pilot fire according to a second embodiment. It is a flowchart of pilot flame fluctuation operation processing concerning a 2nd embodiment. It is an example which showed the relationship between the gas consumption amount and driving time in the fluctuating operation process corresponding to the pilot flame according to the second embodiment.

[First embodiment]
DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a mode for carrying out the present invention, a first embodiment, will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic diagram of a fuel cell system 10 according to this embodiment.

The fuel cell system 10 includes a fuel cell unit 12. A hot water storage tank 14 is attached to the fuel cell unit 12, and the fuel cell system 10 is a so-called cogeneration system.

In addition, in this embodiment, although the fuel cell unit 12 is provided with the hot water storage tank 14 as an example, the fuel cell unit 12 and the hot water storage tank 14 may be separate units.

The fuel cell unit 12 includes a controller 16, a desulfurizer 20, a mass flow controller (MFC) 24, a fuel cell (FC) module 22, an inverter 28, a heat exchanger 30, a hot water tank 14, a temperature sensor 26, and an outside pressure sensor 27. We are prepared.

The desulfurizer 20 removes sulfur and sulfur compounds contained in the gas supplied from the gas supply pipe 18. In this embodiment, city gas 13A is used as the gas.

The fuel cell module 22 has a reforming section and a power generation section inside. The gas that has passed through the desulfurizer 20 is supplied to the fuel cell module 22 via a mass flow controller 24 . The mass flow controller 24 is adjusted by the gas density of the city gas 13A, and supplies the desulfurized gas to the fuel cell module 22 at a normal flow rate. The gas flow rate to the fuel cell module 22 is controlled at a normal flow rate, and power generation operation is performed based on the normal flow rate.

In the reforming section of the fuel cell module 22, the gas that has passed through the desulfurizer 20 is reformed into a gas whose main component is hydrogen. The power generation section uses hydrogen to generate electricity. Electric power from the power generation section of the fuel cell module 22 is converted into alternating current by the inverter 28, and then consumed by power loads such as home appliances 42 (home appliances and lighting).

Hot water is stored in the hot water tank 14. The hot water is heated by heat exchange with the high temperature exhaust gas discharged from the fuel cell module 22 in the heat exchanger 30. The hot water in the hot water storage tank 14 can be used for hot water supply to hot water equipment 44 (shower, bath, sink, etc.) via a backup heat source device (BB) 32 through direct or indirect heat exchange, as well as for floor heating and air conditioning. Used for heat exchange in equipment, etc. By using the hot water stored in the hot water storage tank 14 in this way, the heat generated during power generation can be used, so compared to the case where hot water is heated separately using fuel for hot water supply and heat exchange. , resulting in energy savings.

Although FIG. 1 shows an example in which clean water is directly supplied to the hot water storage tank 14, the clean water is supplied to a clean water heat exchanger that exchanges heat with hot water from the hot water storage tank 14 to generate heat. Exchanges may be made.

The backup heat source device 32 includes a combustor and a heat exchange section inside. The backup heat source device 32 heats the hot water from the hot water storage tank 14 and supplies it to the hot water supply equipment 44 when the hot water desired by the user cannot be supplied from the hot water storage tank 14 (when the hot water temperature is lower than the desired hot water temperature). .

(Configuration of controller 16)
As shown in FIG. 2, the controller 16 includes a CPU 50, a RAM 51, a ROM 52, a storage 54, an I/O 56, and a bus 58 such as a data bus or a control bus that connects these. The storage 54 stores data such as a program for a pilot fire corresponding operation process to be described later, a pilot spark registration flow rate Q0, a micro leakage detection determination period counter C, and a continuous gas detection time T1.

A mass flow controller 24, a fuel cell module 22, an inverter 28, and a backup heat source device 32 are connected to the I/O 56. The controller 16 controls the operations of the mass flow controller 24, the fuel cell module 22, the inverter 28, and the backup heat source (BB) 32. Further, a temperature sensor 26, an external pressure sensor 27, and a remote control panel 34 are connected to the I/O 56.

The temperature sensor 26 is provided in a portion of the fuel cell unit 12 near the outside air, and measures the outside air temperature. The measured outside temperature data K is transmitted to the controller 16. The outside air pressure sensor 27 measures outside air pressure. The measured external pressure data P is transmitted to the controller.

The remote control panel 34 is installed inside the house where the fuel cell system 10 is installed, and has a function for the user to input commands regarding the fuel cell system 10 and a function for displaying the status of the fuel cell system 10. have

As shown in FIG. 1, a gas microcomputer meter 48 (hereinafter referred to as "microcomputer meter 48") is attached to the gas supply pipe 18. A branch part B1 is provided downstream of the microcomputer meter 48, and its branch pipe 18A supplies gas to the fuel cell unit 12, the branch pipe 18B supplies gas to the backup heat source device 32, and the branch pipe 18C supplies gas to the home. Gas is supplied to indoor gas equipment 40 (stove, etc.).

The microcomputer meter 48 measures the actual volumetric flow rate of gas to be supplied, and also has multiple functions for monitoring abnormalities in gas supply (abnormal outflow monitoring function, seismic sensing function, pressure monitoring function, long-term use monitoring function, minute leakage function). detection function, etc.). It also has a spark registration function associated with a small leakage detection function.

The micro leakage detection function issues an alarm (by flashing an alarm lamp, etc.) when the gas supply continues for a certain period of time (for example, 30 days) (when the alarm counter exceeds a threshold value). This fixed period registered in the microcomputer meter 48 is hereinafter referred to as a "minor leak detection determination period T." The definition of "continuous" is that gas is flowing without an interval of one hour or more. In other words, a flow interruption of less than one hour (eg, 59 minutes) is recognized as "continuing." In this embodiment, as an example, the minute leakage detection determination period T is 30 days, and the continuation definition time is 1 hour.

The pilot flame registration function detects a small leakage detection function when gas consumption continues for a continuous judgment time C0 within a predetermined error range of the pilot flame registration flow rate Q0 registered in advance (hereinafter referred to as "pilot flame registration flow rate range QW"). It does not issue a warning. The continuous determination time C0 is shorter than the time defined as "continuation" described above in the minute leakage detection determination period, and is set to, for example, 10 minutes.

The fuel cell system 10 of the present embodiment switches the power generation operation from the load following operation to the pilot fire response operation at the time of determination that is set to occur in a period shorter than the minute leakage detection determination period T. Load following operation is operation that follows the required load. The pilot fire compatible operation is an operation at a gas flow rate (hereinafter referred to as "pilot spark operation flow rate Q1") obtained by correcting the pilot flame registered flow rate Q0 by normal conversion based on the outside temperature and atmospheric pressure.

Here, the minute leak detection determination period counter C, the pilot registration flow rate Q0, the pilot operation flow rate Q1, and the continuous gas detection time C1, which are related to the pilot fire response operation, will be explained.

The pilot flame registration flow rate Q0 is a gas flow rate that is registered in advance in the microcomputer meter 48 because the pilot flame registration function of the microcomputer meter 48 is used as described above. The registered pilot flow rate Q0 is registered as a flow rate corresponding to the actual volume flow rate of gas, and this registered pilot flow rate Q0 is also registered in the controller 16 of the fuel cell system 10.

The pilot operation flow rate Q1 is a gas flow rate obtained by correcting the pilot registration flow rate Q0 to a normal flow rate based on the outside temperature data K and the outside pressure data P. The normal flow rate can be corrected using the following equation (1).

FIG. 3 shows the relationship between the output [W] of the fuel cell system 10 and the actual gas consumption [L/h] when the outside temperature is low temperature KL and high temperature KH. For example, the low temperature KL is the lowest possible outside temperature, and can be assumed to be -10° C., for example. The high temperature KH is the highest possible outside temperature, and can be assumed to be 30° C. as an example. The pilot flame registration flow rate Q0 is set to the actual gas consumption amount during base load operation (minimum output operation that can maintain the power generation function) at high temperature KH. The range of adjustment values ΔD0 above and below the pilot flame registered flow rate Q0 is set as the pilot flame registration flow rate range QW.

At both the outside temperature, low temperature KL and high temperature KH, the actual gas consumption is almost constant from 0 to output W1. At high temperature KH, the gas consumption is within the pilot flame registration flow rate range QW between output 0 and output W2. At low temperature KL, the gas consumption is lower than the pilot register flow rate range QW from output 0 to output W3. Between the output W3 and the output W5, the gas consumption falls within the pilot flame registered flow rate range QW, and at the output W4, the gas consumption amount becomes the pilot flame registration flow rate Q0.

The operation of the fuel cell system 10 at an output corresponding to the pilot flame registered flow rate Q0 (pilot flame operating flow rate Q1: normal flow rate) is referred to as pilot flame compatible operation. In this embodiment, the pilot flame registered flow rate Q0 is set to the gas consumption amount during base load operation (minimum output operation that can maintain the power generation function) at high temperature KH. It is possible to avoid being unable to perform power generation operation. The pilot registered flow rate Q0 does not necessarily need to be set to the gas consumption amount during base load operation at high temperature KH, but it should be set so that the maximum value of the pilot registration flow rate range QW is greater than the gas consumption amount during base load operation. Must be set.

The minute leak detection determination period counter C is for counting the time until the determination time which is set to arrive in a shorter period than the minute leak detection determination period registered in the microcomputer meter 48. In this embodiment, as an example, the minute leakage detection determination period counter C counts 25 days.

The continuous determination time C0 is the time registered in the microcomputer meter 48, and if gas consumption continues within the pilot register flow rate range QW for the continuous determination time C0, the alarm is not issued in the minute leak detection function. . In this embodiment, 10 minutes is set as an example.

The continuous gas detection time C1 is set to be longer than the continuous determination time C0 registered in the microcomputer meter 48, and is a time related to the continuation of the pilot fire response operation, which will be described later. In this embodiment, 90 minutes is set as an example.

FIG. 4 is a front view of the remote control panel 34 according to this embodiment. The remote control panel 34 has a rectangular appearance, and a touch panel section 34B is arranged on the top of the main panel 34A.

The touch panel section 34B displays the time, driving status, set numerical values, etc., and also has a touch pad section that overlaps part or all of the display surface and can recognize the user's touch operations. It looks like this. In FIG. 4, the display on the main panel 34A is an example of a driving status screen, and the main panel 56 can be switched to various different screens by touching the "screen switch" button on the touch pad. In FIG. 4, the words "Initiator ignition response operation in progress", which will be described later, are displayed.

Further, the main panel 34A below the touch panel section 34B is an arrangement area 34C for a plurality of operation switch groups. The operation switch group is a so-called hard switch, and includes an array of operation switches related to hot water supply and power generation.

In the remote control panel 34 shown in FIG. 4, the arrangement position, number, function, shape, etc. of the touch panel section 34B and the operation switch group may be changed depending on the model, year, version, etc. The shape of the panel 34 is not limited.

Next, the pilot fire response operation process in the fuel cell system 10 of this embodiment will be described. During operation of the fuel cell system 10, the pilot fire response operation process is continuously performed by the controller 16 based on the flowchart shown in FIG.

First, in step S12, it is determined whether the count on the minute leakage detection determination period counter C is 25 days or more. If the determination is negative, the process waits in step S12 until the count reaches 25 days or more. If the determination is affirmative, it can be determined that the determination date has arrived, so a correction process is performed in step S14.

In the correction process, as shown in FIG. 6, outside air temperature data K is acquired in step S14A, and outside air pressure data P is acquired in step S14B. Then, in step S14C, the pilot operating flow rate Q1 is calculated from the pilot registered flow rate Q0 based on the outside temperature data K and the outside pressure data P using equation (1).

Next, in step S16, the fuel cell system 10 is controlled to operate at the pilot operation flow rate Q1. That is, the normal flow rate of gas supplied to the fuel cell module 22 via the mass flow controller 24 is controlled to be the pilot operation flow rate Q1. As a result, the gas consumption amount in the fuel cell system 10 becomes the pilot registered flow rate Q0, and the microcomputer meter 48 measures the gas flow rate of the pilot registered flow rate Q0.

In step S18, it is determined whether the continuous gas detection time T1 (90 minutes in this embodiment) has elapsed. If the determination is negative, the process waits in step S18 until the continuous gas detection time T1 has elapsed. If the judgment is affirmative, gas consumption continues for the continuous gas detection time T1 within the pilot register flow rate range QW, so it is possible that the microcomputer meter 48's micro-leakage detection function could have avoided issuing an alarm. expensive. Therefore, in step S20, the minute leakage detection determination period counter C is reset, and in step S22, the operation is returned to load following operation, and the process returns to step S12.

As described above, in the fuel cell system 10 of the present embodiment, the pilot flame registration flow rate Q0 is corrected to the pilot flame operating flow rate Q1 and the pilot flame corresponding operation is performed. It is possible to avoid issuing a warning.

In addition, in this embodiment, when correcting the pilot flame registration flow rate Q0 to the pilot flame operation flow rate Q1, both the outside temperature and the outside pressure are used, but the correction is performed using only either the outside temperature or the outside pressure. Good too. Further, the outside temperature and the outside pressure do not necessarily need to be equipped with a measuring device (temperature sensor or atmospheric pressure sensor) within the fuel cell system 10, and data obtained from external equipment or communication may be used.

Furthermore, in addition to the outside temperature and atmospheric pressure, the pilot registration flow rate Q0 may be corrected to the pilot operation flow rate Q1 based on gas pressure and gas temperature. Furthermore, the pilot registered flow rate Q0 may be corrected to the pilot operating flow rate Q1 based on the internal temperature of the fuel cell unit 12 instead of the outside temperature. As shown in FIG. 7, a pressure gauge 29A and a thermometer 29B are installed in the branch pipe 18A that is sent to the desulfurizer 20, and the gas pressure and gas temperature can be measured. The obtained gas pressure data PG and gas temperature KG are output to the controller 16. In addition, instead of the outside temperature and atmospheric pressure, the pilot registration flow rate Q0 may be corrected to the pilot operation flow rate Q1 based on the gas pressure or gas temperature, or it may be corrected based on only either the gas pressure or the gas temperature. It's okay.

Further, in the present embodiment, in the pilot fire response operation process, the operation at the pilot fire operation flow rate Q1 (pilot fire response operation) is continued only once during the continuous gas detection time T1, and the minute leak detection determination period counter C is reset. The minute leakage detection determination period counter C may be reset on the condition that the process continues multiple times. Furthermore, communication may be performed with the backup heat source device 32, and the case where no ignition occurs in the backup heat source device 32 may be added to the reset conditions.

[Second embodiment]
Next, a second embodiment of the present invention will be described. In this embodiment, parts similar to those in the first embodiment are illustrated with the same reference numerals, and detailed description thereof will be omitted.

The configuration of the fuel cell system of this embodiment is the same as that of the fuel cell system 10 of the first embodiment shown in FIGS. 1 and 2, and the contents of the pilot fire response operation are different. In this embodiment, this is referred to as pilot spark response fluctuation operation processing.

The storage 54 includes data such as a program for fluctuating operation processing for pilot sparks, which will be described later, pilot pilot flow rate Q1 similar to the first embodiment, micro leakage detection determination period counter C, and continuous gas detection time T1, as well as stage continuous time. T2 and step change flow rate ΔQ are stored.

The stage continuous time T2 is a time period during which operation at the same flow rate is maintained when changing the pilot fire operation flow rate Q1 in stages in the fluctuating operation process corresponding to the pilot fire. The stage continuous time T2 is set to be longer than the continuous determination time C0 registered in the microcomputer meter 48.

The step change flow rate ΔQ is the amount by which the gas flow rate is changed when shifting to the next flow rate after maintaining operation at the same flow rate for the step continuous time T2 in the fluctuating operation process corresponding to the pilot fire. The step-change flow rate ΔQ can be set, for example, within the range of the adjustment value D0, which is a half value of the pilot flame registered flow rate range QW.

Next, the fluctuating operation process corresponding to the pilot flame in the fuel cell system 10 of this embodiment will be explained. During the operation of the fuel cell system 10, the pilot spark corresponding fluctuation operation process is continuously performed by the controller 16 based on the flow shown in FIG.

Step S12 and step S14 are executed in the same manner as in the first embodiment. In step S26, pilot flame fluctuation operation processing is executed. As shown in FIG. 9, in the pilot flame fluctuation operation process, in step S30, the fuel cell system 10 is operated with gas consumption at a flow rate that is ΔQ smaller than the pilot flame operation flow rate Q1. As a result, even if the gas flow rate measured by the microcomputer meter 48 is higher than the pilot register flow rate range QW due to the instrumental error of the microcomputer meter 48 and each part of the fuel cell system 10, if it is within the range of ΔQ, the microcomputer meter 48 Therefore, it is recognized that the operation is within the pilot flame registered flow rate Q0.

In step S31, it is determined whether a continuous stage time T2 (10 minutes in this embodiment) has elapsed. If the determination is negative, the process waits in step S31 until the continuous stage time T2 has elapsed. If the determination is affirmative, the process advances to step S32.

In step S32, the fuel cell system 10 is operated with gas consumption of the pilot operation flow rate Q1, and in step S33, it is determined whether the step continuous time T2 has elapsed. If the determination is negative, the process waits in step S33 until the continuous stage time T2 has elapsed. If the determination is affirmative, the process advances to step S34.

In step S34, the fuel cell system 10 is operated with gas consumption at a flow rate ΔQ greater than the pilot operation flow rate Q1. As a result, even if the gas flow rate measured by the microcomputer meter 48 is lower than the pilot register flow rate range QW due to instrumental error in the microcomputer meter 48 and each part of the fuel cell system 10, if it is within the range of ΔQ, the microcomputer meter 48 Therefore, it is recognized that the operation is within the pilot flame registered flow rate Q0.

In step S35, it is determined whether the continuous stage time T2 has elapsed. If the determination is negative, the process waits in step S35 until the continuous stage time T2 has elapsed. If the determination is affirmative, the process advances to step S36.

In step S36, it is determined whether the continuous gas detection time T1 has elapsed. If the determination is negative, the process waits in step S36 until the continuous gas detection time T1 has elapsed. If the judgment is affirmative, gas consumption continues for the continuous gas detection time T1 at the pilot operation flow rate Q1±ΔQ, so it is possible that the microcomputer meter 48 could have avoided issuing an alarm with its micro leak detection function. expensive. Therefore, in step S20, the minute leakage detection determination period counter C is reset, and in step S22, the process returns to load following operation, and the process returns to step S12.

As an example, FIG. 10 shows the relationship between gas consumption and operating time when the fuel cell system 10 is operated at the pilot operating flow rate Q1 but the gas consumption is slightly less than the pilot registered flow rate range QW. relationship is shown. In the fluctuating operation process corresponding to the pilot flame of this embodiment, when the gas consumption amount controlled by the fuel cell system 10 is Q1-ΔQ, Q1, the gas consumption amount does not fall within the pilot flame registration flow rate range QW, and the fuel cell system 10 When the controlled gas consumption amount is Q1+ΔQ, the gas consumption amount falls within the pilot flame registration flow rate range QW.

In the fuel cell system 10 of this embodiment, the pilot flame registration flow rate Q0 is corrected to the pilot flame operation flow rate Q1 to perform the pilot flame compatible operation. It is possible to avoid issuing an alarm in the leakage detection function.

Furthermore, in this embodiment, the flow rate of the pilot operation flow rate Q1 is varied up and down to continue gas consumption within the range of ±ΔQ for the continuous stage time T2. Therefore, even if there is an instrumental error between the microcomputer meter 48 and each device of the fuel cell system 10, the gas flow rate measured by the microcomputer meter 48 can be kept within the pilot flame registration flow rate range QW, and the pilot flame registration function of the microcomputer meter 48 By using this, it is possible to avoid issuing an alarm in the micro leakage detection function.

In this embodiment, the pilot fire response operation was performed in three stages of gas flow rate: pilot fire operation flow rate Q1 - ΔQ, pilot fire operation flow rate Q1, pilot fire operation flow rate Q1 + ΔQ, but the pilot fire response operation is divided into more stages. You may do so.

10 Fuel cell system 12 Fuel cell unit 16 Controller (correction section, pilot spark operation switching section, continuous pilot operation judgment section, load following operation switching section)
24 Mass flow controller 48 Gas microcomputer meter ΔQ Step change flow rate C0 Continuous judgment time C1 Continuous gas detection time C Minute leak detection judgment period counter Q0 Pilot flame registered flow rate Q1 Pilot flame operation flow rate QW Pilot flame registered flow rate range K Outside temperature data P Outside pressure data PG Gas pressure data KG Gas temperature data T Micro leak detection judgment period T1 Continuous gas detection time T2 Continuous stage time D0 Adjustment value

Claims (6)

A fuel cell unit that is operated using gas passed through a gas microcomputer meter and whose gas flow rate used for power generation operation is controlled at a normal flow rate;
The pilot registered flow rate registered in the gas microcomputer meter in advance is corrected to a pilot operation flow rate that approaches the normal flow rate based on at least one of the temperature inside the fuel cell unit, the outside temperature, the outside pressure, the gas temperature, and the gas pressure. a correction section to
a pilot fire response operation switching unit that switches the operation of the fuel cell unit to a pilot fire response operation in which the fuel cell unit is operated at the pilot fire operation flow rate at the time of determination during a predetermined minute leakage detection determination period;
a pilot fire operation maintenance unit that continues the pilot fire response operation for a predetermined continuous gas detection time;
Equipped with
The pilot operation maintenance unit is
a continuous pilot fire operation determination unit that determines whether the pilot fire response operation is maintained during the continuous gas detection time;
a load following operation switching section that switches the fuel cell unit to a load following operation according to the electric power load when the judgment by the continuous pilot operation judgment section is affirmative;
has,
fuel cell system. A fuel cell unit that is operated using gas passed through a gas microcomputer meter and whose gas flow rate used for power generation operation is controlled at a normal flow rate;
The pilot registered flow rate registered in the gas microcomputer meter in advance is corrected to a pilot operation flow rate that approaches the normal flow rate based on at least one of the temperature inside the fuel cell unit, the outside temperature, the outside pressure, the gas temperature, and the gas pressure. a correction section to
a pilot fire response operation switching unit that switches the operation of the fuel cell unit to a pilot fire response operation in which the fuel cell unit is operated at the pilot fire operation flow rate at the time of determination during a predetermined minute leakage detection determination period;
a pilot fire operation maintenance unit that continues the pilot fire response operation for a predetermined continuous gas detection time;
Equipped with
The pilot registration flow rate is a gas flow rate corresponding to the base power generation maintenance output of the fuel cell unit,
fuel cell system. 2. The gas microcontroller according to claim 1, wherein during the pilot operation, continuous operation is performed at a plurality of different pilot adjustment flow rates in which the pilot operation flow rate is corrected by an adjustment value for a continuous stage time longer than a continuous judgment time of the gas microcomputer meter. The fuel cell system according to claim 2 . A method of operating a fuel cell system, which is operated using gas passed through a gas microcomputer meter, and in which the gas flow rate used for power generation operation is controlled at a normal flow rate,
The pilot registration flow rate registered in advance in the gas microcomputer meter is changed to a pilot operation flow rate that approaches a normal flow rate based on at least one of the temperature inside the fuel cell unit, the outside air temperature, the outside pressure, the gas temperature, and the gas pressure. Correct,
During a predetermined minute leakage detection determination period, the pilot fire response operation operated at the pilot fire operation flow rate continues the operation of the fuel cell unit for a predetermined continuous gas detection time;
After the pilot fire response operation is maintained during the continuous gas detection time, switching the fuel cell unit to a load following operation according to the electric power load;
How to operate a fuel cell system. A method of operating a fuel cell system, which is operated using gas passed through a gas microcomputer meter, and in which the gas flow rate used for power generation operation is controlled at a normal flow rate,
The pilot registration flow rate registered in advance in the gas microcomputer meter is changed to a pilot operation flow rate that approaches a normal flow rate based on at least one of the temperature inside the fuel cell unit, the outside air temperature, the outside pressure, the gas temperature, and the gas pressure. Correct,
During a predetermined minute leakage detection determination period, the pilot fire response operation operated at the pilot fire operation flow rate continues the operation of the fuel cell unit for a predetermined continuous gas detection time;
The pilot registration flow rate is a gas flow rate corresponding to the base power generation maintenance output of the fuel cell unit,
How to operate a fuel cell system. 5. During the pilot fire corresponding operation, the gas microcomputer meter continuously operates at a plurality of different pilot pilot adjustment flow rates, each of which is corrected by an adjustment value, for a continuous stage time longer than the continuous judgment time of the gas microcomputer meter. A method of operating a fuel cell system according to claim 5 .