JP7357568B2 - Fuel cell system inspection method and installation target determination method - Google Patents

Description

The present invention relates to a method of inspecting a fuel cell system including a fuel cell section and a method of determining a target to which a filter is attached.

The above fuel cell system supplies air to the cathode of the fuel cell section, and supplies fuel gas containing hydrogen as a main component to the anode, and generates electricity through a chemical reaction between hydrogen and oxygen. .

In this type of fuel cell system, it is known that the power generation performance of the fuel cell decreases due to various factors. For example, Patent Document 1 states that when an alkaline earth metal such as Sr is present in the air electrode layer of a solid oxide fuel cell, sulfur contained in the air decreases in power generation efficiency in a fuel cell system. It is stated that oxides adhere to alkaline earth metals in the air electrode layer, poisoning the air electrode layer, increasing the reaction resistance of the air electrode layer, and reducing the power generation performance of the fuel cell. There is.

JP2014-26926A

By the way, if the power generation performance of the fuel cell decreases, the power generation efficiency of the fuel cell system will decrease, and therefore the fuel cell stack/module will need to be replaced. Deterioration in the power generation performance of fuel cells in a fuel cell system is caused not only by the accumulation of sulfur oxides contained in the air in the air electrode layer, but also by physical damage to the fuel cells due to external stimuli. It is also caused by diffusion of elements at the interface of the air electrode layer material, deterioration and alteration of the material itself, etc. If the cause of the decline in power generation performance can be identified, the fuel cell stack/module should be replaced. You will be able to take appropriate action when the situation arises.

A conventional method for identifying the factors that reduce the power generation performance of fuel cells is to remove and disassemble the fuel cell stack/module from the fuel cell system and analyze the components of the fuel cells. . However, in a fuel cell system, once the fuel cell stack/module is removed and disassembled, it cannot be restored, so the fuel cell stack/module cannot be replaced regardless of whether the cause has been identified. This is unavoidable, and the cost of disassembly and analysis is extremely high.

The present invention has been made in view of the above-mentioned circumstances, and provides a method for testing a fuel cell system that can easily test for factors that reduce the power generation performance of a fuel cell in a fuel cell system, and a test method obtained by the testing method. The purpose of the present invention is to provide a method for determining objects to which sulfur oxide removal filters are installed based on test results.

For fuel cell systems in which a sulfur compound removal filter is not installed in the supply path that supplies air to the fuel cell section, the inventor of the present application has proposed that when the power generation performance of the fuel cell section decreases, a sulfur compound removal filter is installed in the supply path. It was discovered that the power generation performance of the fuel cell may be restored when the fuel cell is installed, and furthermore, when the power generation performance is restored in this way, the power generation performance of the fuel cell is reduced due to the accumulation of sulfur compounds contained in the air in the fuel cell. The present invention was completed based on the new finding that it is possible to identify a decrease in

That is, the characteristic configuration of the fuel cell system inspection method according to the present invention for achieving the above object is as follows:
A method for inspecting a fuel cell system including a fuel cell section, the method comprising:
A first index for operating the fuel cell system by supplying fuel gas and air at a predetermined flow rate to the fuel cell section, and measuring an index value indicating power generation performance of the fuel cell section at a predetermined inspection timing. a value measurement process;
If the index value measured in the first index value measurement step is less than a predetermined reference index value, a sulfur compound removal filter is installed in the supply path that supplies air to the fuel cell section for removing sulfur compounds. The filter installation process,
After the filter attachment step, a second index value measurement step of supplying fuel gas and air to the fuel cell unit at a predetermined flow rate to operate the fuel cell system and measure the index value;
When the index value measured in the second index value measurement step is greater than or equal to the index value measured in the first index value measurement step, the fuel cell is reduced by accumulation of the sulfur compound in at least the fuel cell section. The point is that a judgment step is carried out to determine that the power generation performance of the section is decreasing.

In the above characteristic configuration, the index value is measured at a predetermined inspection timing during operation by supplying fuel gas and air at a predetermined flow rate to the fuel cell section, and if the measured index value is less than the reference index value, the fuel After determining that the power generation performance of the battery has deteriorated, a sulfur compound removal filter is installed in the air supply path. Thereafter, fuel gas and air are supplied to the fuel cell section at a predetermined flow rate to operate the fuel cell system and measure the index value.
According to new findings discovered by the inventor of the present application, when a fuel cell system is operated with a sulfur compound removal filter attached, the amount of sulfur compounds in the air supplied to the fuel cell section decreases. If sulfur compounds have accumulated in the fuel cell section, the accumulated sulfur compounds will be desorbed by air flow, so if the power generation performance of the fuel cell section has decreased due to the accumulation of sulfur compounds, The power generation performance of the fuel cell section is restored.
Therefore, in the above characteristic configuration, the index values measured before and after the installation of the sulfur compound removal filter are compared, and if the index value measured after the installation of the sulfur compound removal filter is greater than or equal to the index value measured before installation, the sulfur Since the power generation performance of the fuel cell section has been restored by installing the compound removal filter, it is determined that the power generation performance of the fuel cell section has decreased at least due to the accumulation of sulfur compounds in the fuel cell section.
As described above, according to the above characteristic configuration, it is possible to identify that the power generation performance of the fuel cell section is reduced due to the accumulation of sulfur compounds in the fuel cell section, simply by installing the sulfur compound removal filter, and to remove the fuel. Compared to a method in which the battery cell stack/module is taken out and disassembled to analyze the components of the fuel cell, it is possible to identify the cause of the decline in power generation performance easily and at low cost.

Further, a characteristic configuration of another method for testing a fuel cell system according to the present invention for achieving the above object is a method for testing a fuel cell system including a fuel cell section, comprising:
Index value measurement of supplying fuel gas and air to the fuel cell unit at a predetermined flow rate to operate the fuel cell system, and measuring an index value indicating power generation performance of the fuel cell unit at a predetermined inspection timing. process and
A filter in which a sulfur compound removal filter for removing sulfur compounds is attached to a supply path that supplies air to the fuel cell section when the index value measured in the index value measurement step is less than a predetermined reference index value. Installation process and
After the filter attachment step, the fuel cell system is operated by supplying fuel gas and air at a predetermined flow rate to the fuel cell unit, and the index value is measured, and the index value is measured at a predetermined rate from the start of operation after the filter attachment step. An index value decrease rate calculation step of calculating the decrease rate of the index value during the measurement period until time elapses;
If the rate of decrease in the index value regarding the fuel cell system calculated in the index value decrease rate calculation step is smaller than the reference index value decrease rate in the period corresponding to the measurement period, at least the The present invention also includes a determination step of determining that the power generation performance of the fuel cell unit is degraded due to accumulation of sulfur compounds.

In the above characteristic configuration, the index value is measured at a predetermined inspection timing during operation by supplying fuel gas and air at a predetermined flow rate to the fuel cell section, and if the measured index value is less than the reference index value, the fuel After determining that the power generation performance of the battery section has deteriorated, a sulfur compound removal filter is installed in the air supply path. After that, the fuel cell system is operated by supplying fuel gas and air at a predetermined flow rate to the fuel cell section, and the index value is measured. Calculate the rate of decline in the index value.
Here, the rate of decrease in the index value of the fuel cell system calculated as described above is calculated based on whether the decrease in power generation performance is due to the accumulation of sulfur compounds in the fuel cell or if the sulfur compounds are removed. than if the sulfur compounds were not removed. Therefore, for equipment in which sulfur compounds have not been removed, the rate of decrease in the index value during the period corresponding to the above measurement period is calculated, and this rate of decrease in the index value is taken as the standard index value decrease rate, and in the index value decrease rate calculation step. By comparing the calculated decrease rate of the index value regarding the fuel cell system with the reference index value decrease rate, it can be determined whether the decrease in power generation performance is due to accumulation of sulfur compounds in the fuel cell section.
That is, in the above characteristic configuration, when the rate of decrease in the index value regarding the fuel cell system calculated in the index value decrease rate calculation step is smaller than the predetermined standard index value decrease rate, the sulfur compound removal filter is installed. Since the power generation performance of the fuel cell section is on a recovery trend, it is determined that the power generation performance of the fuel cell section is decreasing at least due to the accumulation of sulfur compounds in the fuel cell section.
As described above, according to the above characteristic configuration, it is possible to identify that the power generation performance of the fuel cell section is reduced due to the accumulation of sulfur compounds in the fuel cell section, simply by installing the sulfur compound removal filter, and to remove the fuel. Compared to a method in which the battery cell stack/module is taken out and disassembled to analyze the components of the fuel cell, it is possible to identify the cause of the decline in power generation performance easily and at low cost.

Further, a further feature of the fuel cell system inspection method according to the present invention is that the reference index value reduction rate is determined by the rate of decrease in the reference index value when the fuel cell system is installed in an area including the installation location and the sulfur compound removal filter is installed. It is the rate of decline of the index value in a period corresponding to the measurement period of other fuel cell systems.

Note that the above-mentioned inspection timing is preferably a timing at which the cumulative operating time of the fuel cell system becomes long to some extent and the power generation performance of the fuel cell section may deteriorate.

That is, a further feature of the fuel cell system inspection method according to the present invention is that the inspection timing is a timing at which the cumulative operating time of the fuel cell system reaches a predetermined time.

A further feature of the fuel cell system inspection method according to the present invention is that the index value is an output voltage of the fuel cell unit.

According to the characteristic configuration described above, since the output voltage of the fuel cell section can be measured by the function provided in a general fuel cell system, there is no need to provide a separate measurement means to measure the index value, and the fuel cell system can be prevented from becoming complicated.

Furthermore, among various sulfur compounds, the accumulation of SO ₂ , SO ₃ and H ₂ S in particular is thought to have a large effect on the power generation performance of the fuel cell, and it is necessary to remove at least one of these with a sulfur compound filter. If it is confirmed that the power generation performance has recovered in this case, it can be determined that the decrease in the power generation performance of the fuel cell section is due to the accumulation of sulfur compounds.

That is, a further feature of the fuel cell system inspection method according to the present invention is that the sulfur compound is one or more selected from the group consisting of SO ₂ , SO ₃ and H ₂ S.

Further, a further characteristic configuration of the fuel cell system inspection method according to the present invention is that the fuel cell system is provided with an impurity removal filter for removing impurities in the supply path,
In the filter attachment step, the sulfur compound removal filter is attached closer to the fuel cell section than the impurity removal filter.

In the fuel cell system inspection method according to the present invention, index values are measured before and after installing the sulfur compound removal filter, and a judgment step is performed based on the measured index values. Since the index value after the sulfur compound removal filter is installed varies depending on the performance of the sulfur compound removal filter, it is important to maintain the performance of the sulfur compound removal filter above a certain level in order to improve inspection accuracy.
According to the above characteristic configuration, since the air from which relatively large impurities such as dust and dust have been removed by the impurity removal filter flows through the sulfur compound removal filter, the performance of the sulfur compound removal filter is affected by the impurities such as dust and dirt. The performance of the sulfur compound removal filter can be maintained above a certain level without being easily damaged, and the inspection accuracy can be improved.

Further, the characteristic configuration of the attachment target determination method according to the present invention is such that the fuel cell system inspection method determines that the power generation performance of the fuel cell section is degraded due to at least the accumulation of the sulfur compound in the fuel cell section. The present invention includes an installation target determining step of determining another fuel cell system installed in an area including the installation location of the fuel cell system that has been installed as a target for installing the sulfur compound removal filter.

Areas including areas where fuel cell systems have been installed where it has been determined that the power generation performance of the fuel cell unit has deteriorated due to the accumulation of sulfur compounds in the fuel cell unit using the fuel cell system inspection method described above must be This area is thought to have a relatively large amount of sulfur compounds. Therefore, for other fuel cell systems installed in such areas, the power generation performance of the fuel cell section will decrease due to the accumulation of sulfur compounds in the fuel cell section, although the degree of change will vary depending on the operating time etc. There is a possibility that
Therefore, in the characteristic configuration described above, these other fuel cell systems are determined to be the target for attaching the sulfur compound removal filter.
As described above, according to the above characteristic configuration, other fuel cell systems in which there is a possibility that the power generation performance of the fuel cell section may be degraded due to the accumulation of sulfur compounds in the fuel cell section are determined to be the target for installing the sulfur compound removal filter. Therefore, for example, by attaching the sulfur compound removal filter to other fuel cell systems determined to be attached, the power generation performance of the fuel cell section can be restored.

1 is a diagram illustrating a schematic configuration of a fuel cell system that is an inspection target of an inspection method according to an embodiment. FIG. 2 is a functional block diagram showing an operation control section of the fuel cell system. It is a graph showing experimental results. 2 is a flowchart for explaining a series of flows of an inspection method and an attachment target determination method according to an embodiment. FIG. 2 is a diagram showing a schematic configuration of a fuel cell system after a sulfur compound removal filter is attached. It is a graph showing experimental results.

Hereinafter, a method for inspecting a fuel cell system and a method for determining an installation target according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a fuel cell system, and FIG. 2 is a functional block diagram showing an operation control section 20. As shown in FIG. The fuel cell system F includes a fuel gas generation device 1 that generates fuel gas by reforming raw fuel gas (for example, city gas containing methane, etc.) as a raw fuel, and a fuel gas generation device 1 that generates fuel gas by reforming raw fuel gas (for example, city gas containing methane). It includes a fuel cell power generation device 10 that generates electricity using gas as fuel, and an operation control unit 20 that controls the operation of these devices.

The fuel gas generation device 1 includes a vaporization section 2 that vaporizes reformed water to generate a mixed gas of water vapor and raw fuel gas, and a vaporization section 2 that vaporizes reformed water to generate a mixed gas of water vapor and raw fuel gas, and a vaporizer 2 that reformes the raw fuel gas to generate a fuel gas containing hydrogen as a main component. A reforming section 3 that generates fuel components, a combustion section 4 that heats the vaporizing section 2 and the reforming section 3 by burning fuel components, and a raw fuel supplying raw fuel gas to the vaporizing section 2 through the raw fuel supply path L1. A first on-off valve 6 that can freely open and close the raw fuel supply path L1, and a reformed water pump 9 for supplying reformed water to the vaporization section 2 through the reformed water supply path L2 are provided. ing. Further, the raw fuel supply path L1 is provided with a raw fuel flow meter 8 that measures the flow rate of the raw fuel gas supplied by the raw fuel blower 5.

The reforming section 3 is supplied with the mixed gas generated in the vaporizing section 2, reforming the raw fuel gas in the presence of water vapor, and producing a fuel gas containing hydrogen as a main component. Specifically, in the reforming section 3, the raw fuel gas is steam-reformed using the heat generated in the combustion section 4 provided adjacent to it, so that hydrogen is the main component and hydrogen is produced as a by-product. A reformed gas containing carbon monoxide and carbon dioxide is produced. The fuel gas generated by the reformer 3 is supplied to the fuel cell power generation device 10 through the fuel gas supply path L3.

The supply amount of the raw fuel gas supplied through the raw fuel supply path L1 is measured by the raw fuel flow meter 8, and the operation control unit 20 controls the raw fuel gas so that the measured flow rate becomes a preset target flow rate. Adjust the output of the blower 5. When the raw fuel blower 5 is not operating, such as when the operation is stopped, the first on-off valve 6 is closed. Further, the operation control unit 20 operates the reforming water pump 9 so that the amount of reforming water supplied through the reforming water supply path L2 becomes a predetermined supply amount.

The combustion section 4 burns combustible gas to generate heat. As the combustible gas, exhaust gas containing hydrogen that has not been consumed in the power generation reaction in the fuel cell power generation device 10, raw fuel gas, or a mixture of both can be used as the combustible gas. In addition, the combustion section 4 is supplied with air that is not consumed in the fuel cell power generation device 10, as will be described later, as air (oxygen) for combustion of the combustible gas.

The fuel cell power generation device 10 includes a fuel cell section 11 which is supplied with the above-mentioned fuel gas and oxygen gas for power generation to generate electricity, and a fuel cell section 11 that supplies oxygen gas for power generation to the fuel cell section 11 through an oxygen supply path L4 for power generation. a second on-off valve 13 that can open and close the power-generating oxygen supply path L4; and an impurity removal filter for removing impurities in the power-generating oxygen gas supplied by the power-generating oxygen blower 12. 14, and a voltage detection section 15 that detects the output voltage of the fuel cell section 11. Further, the power generation oxygen supply path L4 is provided with a power generation oxygen flow meter 16 that measures the flow rate of the power generation oxygen gas supplied by the power generation oxygen blower 12.

The fuel cell unit 11 is a solid oxide fuel cell, and is configured by stacking a plurality of cells each including an anode 11a, a cathode 11b, and an electrolyte membrane 11c sandwiched therebetween. In this fuel cell section 11, the fuel gas generated in the reforming section 3 is supplied to the anode 11a through the fuel gas supply path L3, and the oxygen gas (air) for power generation is supplied to the cathode 11b through the power generation oxygen supply path L4. A power generation reaction takes place. The output power (that is, the index value indicating power generation performance) of the fuel cell unit 11 is adjusted by the operation control unit 20 using an inverter (not shown), and the power is supplied to the power consumption device (not shown). Supplied.

In this fuel cell section 11, of the hydrogen contained in the fuel gas supplied to the anode 11a, excess hydrogen that is not consumed in the power generation reaction in the fuel cell section 11 is discharged from the anode 11a and flows through the exhaust gas flow path L5. The gas is then supplied to the combustion section 4, where it is burned as a combustible gas.
Further, of the oxygen contained in the air supplied to the cathode 11b, excess oxygen that is not consumed in the power generation reaction in the fuel cell section 11 is discharged from the cathode 11b and passes through the exhaust gas flow path L5 to the combustion section 4. Supplied.

In this fuel cell system F, the amount of power generation oxygen gas supplied to the cathode 11b through the power generation oxygen supply path L4 is measured by the power generation oxygen flowmeter 16, and the measured flow rate is set in advance. The operation control unit 20 adjusts the output of the power generation oxygen blower 12 so that the target flow rate is reached. Note that when the power generation oxygen blower 12 is not operating, such as when the operation is stopped, the second on-off valve 13 is in a closed state.

In this embodiment, the vaporizing section 2, reforming section 3, combustion section 4, fuel cell section 11, etc. are housed inside a high-temperature housing M that is configured using a heat insulating material or the like to prevent internal heat from escaping to the outside. is set up.

As shown in FIG. 2, the operation control unit 20 includes a blower output adjustment unit 21, an information acquisition unit 22, a valve control unit 23, a pump control unit 24, an operation time determination unit 25, a voltage determination unit 26, a determination unit 27, and It includes a storage section 28 and a display section 30 that displays various information. The operation control unit 20 also receives various signals from the raw fuel flowmeter 8 and the power generation oxygen flowmeter 16.

Then, the operation control unit 20 outputs predetermined signals to the raw fuel blower 5, the power generation oxygen blower 12, the first on-off valve 6, and the second on-off valve 13 based on the input various signals.

The blower output adjustment section 21 is configured to control the outputs of the raw fuel blower 5 and the power generation oxygen blower 12.

The information acquisition unit 22 is configured to acquire the flow rate measured by the raw fuel flowmeter 8 and the power generation oxygen flowmeter 16 and the voltage detected by the voltage detection unit 15.

The valve control unit 23 is configured to perform opening/closing control of the first on-off valve 6 and the second on-off valve 13.

The pump control unit 24 is configured to control the operation of the reformed water pump 9.

The operating time determining unit 25 appropriately refers to the cumulative operating time of the fuel cell system F stored in the storage unit 28 and determines whether or not the cumulative operating time has reached a predetermined time (inspection timing). do. Note that the predetermined time is, for example, a time when maintenance is required (for example, 10,000 hours).

The voltage determination unit 26 determines whether the voltage detected by the voltage detection unit 15 at the test timing, which is stored in the storage unit 28, is less than a predetermined reference voltage (reference index value). Note that the reference voltage is a voltage that can be determined in advance based on the correlation between the operating time of the fuel cell system and the output voltage of the fuel cell unit 11 when the output voltage of the fuel cell unit 11 gradually decreases due to long-term use. It is.

Here, as a result of extensive research, the inventor of the present application found that when a sulfur compound removal filter is attached to a fuel cell system F in which the power generation performance of the fuel cell section 11 has decreased, the power generation performance of the fuel cell section 11 is restored. In this case, new knowledge was obtained that it is possible to identify that the power generation performance of the fuel cell section 11 is reduced due to the accumulation of sulfur compounds contained in the air in the fuel cell section 11.

Incidentally, the inventor of this application reproduced the case where a sulfur compound removal filter was installed and the case where the sulfur compound removal filter was not installed after a certain period of power generation operation, and determined the difference in the power generation performance of the fuel cell section between the two. We conducted an experiment to verify whether such a difference appears. Specifically, after 10,000 hours of power generation operation for two fuel cell systems, power generation operation was performed by continuously supplying air containing 20 ppb of SO ₂ to the cathode; An experiment was conducted in which the addition of SO ₂ was stopped approximately 2,000 hours after the start of addition of fuel cell system _{No. 2} , and the other fuel cell system was operated for power generation for 4,000 hours with continued addition of SO ₂ . FIG. 3 is a graph showing the results of this experiment, with the horizontal axis representing the power generation operation time and the vertical axis representing the voltage change rate (immediately after the start of SO ₂ addition is taken as 100%). As can be seen from the figure, in a device where SO ₂ addition is stopped mid-operation (that is, a state _in which a sulfur compound removal filter is installed mid-operation), the voltage change rate is was higher than before the addition of SO ₂ was stopped, confirming that the power generation performance of the fuel cell section had recovered. For example, in a device in which SO ₂ addition was stopped during operation, the voltage change rate was 99.3% at 1999 hours after starting SO ₂ addition, and recovered to 99.7% at 2289 hours. . On the other hand, in the case of the device in which SO ₂ addition was not stopped during operation, the voltage change rate was 98.8% at 1999 hours after the start of SO ₂ addition, and 98.6% at 2289 hours. , and there is no sign of recovery.

In the present embodiment, the determining unit 27 uses the voltage detected by the voltage detecting unit 15 at the above-mentioned inspection timing and thereafter performs the operation of the fuel cell system in which the sulfur compound removal filter is attached to the fuel cell system. The voltage detected by the voltage detection unit 15 during operation after the sulfur compound removal filter was installed is higher than the voltage detected by the voltage detection unit 15 at the inspection timing. If the voltage is higher, it is determined that the power generation performance of the fuel cell unit 11 is degraded due to the accumulation of sulfur compounds.

In this fuel cell system F, when performing a power generation operation in which the fuel cell section 11 performs a power generation reaction, the valve control section 23 causes the first on-off valve 6 and the second on-off valve 13 to be in the open state. The operation of each on-off valve 6, 13 is controlled, the raw fuel gas supply amount is measured by the raw fuel flowmeter 8, the measurement result is acquired by the information acquisition unit 22, and the acquired flow rate is set in advance. The blower output adjustment unit 21 adjusts the output of the raw fuel blower 5 so that the target flow rate is reached, and the pump control unit 24 adjusts the reformed water pump so that the supplied amount of reformed water reaches a predetermined amount. Controls the operation of 9. Similarly, the supply amount of oxygen for power generation is measured by the power generation oxygen flow meter 16, and the information acquisition unit 22 acquires the measurement result, so that the obtained flow rate becomes a preset target flow rate. , the blower output adjustment section 21 adjusts the output of the power generating oxygen blower 12.

Next, a method of inspecting the fuel cell system F and a method of determining a subject to which a sulfur compound removal filter is to be attached based on the inspection results will be explained with reference to FIG. In the following, an example will be explained in which a fuel cell system F is inspected while it is in power generation operation.

First, in step #1, the operating time determination unit 25 determines whether the cumulative operating time up to now has reached a predetermined time, in other words, whether it is inspection timing, and if the inspection timing has come, The process moves to process #2, and if the inspection timing has not come, process #1 is repeated.

Next, in step #2, the information acquisition section 22 acquires the voltage detected by the voltage detection section 15 at the inspection timing (first index value measurement step), and the process moves to step #3.

In step #3, the voltage determination unit 26 determines whether the voltage acquired by the information acquisition unit 22 is less than the reference voltage stored in the storage unit 28, and if it is determined that the voltage is less than the reference voltage, The process moves to step #4, and if it is determined that the voltage is equal to or higher than the reference voltage, the process returns to step #1. Note that when it is determined in step #3 that the voltage is equal to or higher than the reference voltage and the process returns to step #1, in step #1, the operating time determination unit 25 determines whether the test timing is later than the above-mentioned test timing. do.

In step #4, a display notifying that the output voltage of the fuel cell section 11 is less than the reference voltage is displayed on the display section 30 of the operation control section 20, and the process moves to step #5.

In step #5, as shown in FIG. 5, a sulfur compound removal filter for removing sulfur compounds is installed between the power generation oxygen blower 12 and the impurity removal filter 14 of the fuel cell power generation device 10 in the fuel cell system F. 17 (filter installation process) and move on to process #6. Examples of the sulfur compounds removed by the sulfur compound removal filter 17 include SO ₂ , SO ₃ , and H ₂ S, which are considered to have a relatively large influence on the power generation performance of the fuel cell section 11 . Further, the sulfur compound removal filter 17 is preferably capable of removing sulfur compounds so that the concentration of sulfur compounds in the air is 1 ppb or less.

Subsequently, as shown in FIG. 4, in step #6, the fuel cell system F performs a power generation operation, and the output voltage of the fuel cell unit 11 during the power generation operation is obtained (second index value measurement step). That is, in step #6, the valve control unit 23 controls the operation of the first on-off valve 6 and the second on-off valve 13 so that they are in the open state. Further, the blower output adjustment unit 21 adjusts the output of the raw fuel blower 5 and the power generation oxygen blower 12 so that the supply amount of the raw fuel gas and the power generation oxygen reaches the preset target flow rate, and The pump control unit 24 controls the operation of the reforming water pump 9 so that the amount of reformed water supplied is a predetermined amount. As a result, power generation operation is performed under the same conditions as during the first index value measurement step. Then, while the fuel cell system F is performing power generation operation, the information acquisition section 22 acquires the voltage detected by the voltage detection section 15 (second index value measurement step), and the process moves to step #7.

In step #7, the determining unit 27 compares the voltage measured in the first index value measurement step (first voltage) and the voltage measured in the second index value measurement step (second voltage), and determines the second It is determined whether the voltage is higher than the first voltage, and if it is determined that the second voltage is higher than the first voltage (that is, when the power generation performance of the fuel cell section 11 has been recovered), the process moves to step #8. However, in step #8, the determining section 27 determines that the power generation performance of the fuel cell section 11 is reduced due to the accumulation of sulfur compounds (determination step), and this fact is displayed on the display section 30, and step #10 to move to.

On the other hand, in step #7, if the determining section 27 determines that the second voltage is lower than the first voltage, the process moves to step #9, and the determining section 27 determines that the power generation performance of the fuel cell section 11 is lower than that of the sulfur compound. It is determined that the decrease is due to a factor other than accumulation, a message to that effect is displayed on the display unit 30, and the series of flows ends.

Here, under the same environment as the fuel cell system F in which it was determined that the power generation performance of the fuel cell section 11 has decreased due to the accumulation of sulfur compounds, in other words, the amount of sulfur compounds contained in the air is the same. Regarding other fuel cell systems installed in a similar environment, although there are some differences depending on the length of operation time, similar to the tested fuel cell system F, the power generation performance of the fuel cell section 11 is affected by the accumulation of sulfur compounds. There is a high possibility that it is decreasing.

Therefore, in step #10, other fuel cell systems installed in the area including the installation location of the fuel cell system F in which it was determined that the power generation performance of the fuel cell unit 11 has decreased due to the accumulation of sulfur compounds, It is determined that the sulfur compound removal filter 17 is to be installed (installation target determination step). The area including the installation location of the fuel cell system F where it has been determined that the power generation performance of the fuel cell unit 11 has decreased due to the accumulation of sulfur compounds is considered to be an area where the amount of sulfur compounds contained in the air is large. Therefore, by determining other fuel cell systems installed in the area to be installed with the sulfur compound removal filter 17, the sulfur compound removal filter 17 can be installed on the other fuel cell systems determined as the installation target, and the sulfur compound removal filter 17 can be installed. It becomes possible to recover the power generation performance of the fuel cell section 11 in other fuel cell systems.

Note that the attachment target determination step can be performed in various ways. For example, the fuel cell system F transmits information that the power generation performance of the fuel cell unit 11 is decreasing due to the accumulation of sulfur compounds to the server device via the network, and the server device receives information from the government, private companies, etc. With reference to the provided sulfur compound concentration map, etc., the fuel cell unit 11 is installed in an area with a similar sulfur compound concentration as the fuel cell system F in which the power generation performance is determined to be degraded due to accumulation of sulfur compounds. Other fuel cell systems can be determined as installation targets. Alternatively, a person performing maintenance work may check the display on the display unit 30 and operate an appropriate external device that can communicate with the server device via the network to ensure that the power generation performance of the fuel cell unit 11 is Other fuel cell systems installed in areas where the concentration of sulfur compounds is similar to that of fuel cell system F, which has been determined to have decreased due to accumulation of compounds, can be determined as installation targets.

As described above, according to the fuel cell system inspection method according to the present embodiment, simply by attaching the sulfur compound removal filter 17, the power generation performance of the fuel cell section 11 is improved due to the accumulation of sulfur compounds in the fuel cell section 11. It is possible to identify the decline.

Further, according to the installation target determination method according to the present embodiment, there is a possibility that the power generation performance of the fuel cell section 11 is reduced due to the accumulation of sulfur compounds, similar to the fuel cell system F inspected by the above inspection method. The power generation performance of the fuel cell unit 11 can be restored by attaching the sulfur compound removal filter to other fuel cell systems that have been determined to be the target of installation. It becomes possible.

[Another embodiment]
[1] In the above embodiment, the inspection timing is the timing when the cumulative operating time of the fuel cell system F reaches a predetermined time, but the inspection timing is not limited to this.

[2] In the above embodiment, the output voltage of the fuel cell unit 11 is used as the index value from the viewpoint that it can be measured using the functions provided in a general fuel cell system, but the index value is not limited to this, and for example, The electromotive force of the fuel cell unit 11 may be used as the index value. Further, the index value is not limited to one that can be measured by a function provided in a general fuel cell system, and is not particularly limited as long as it indicates the power generation performance of the fuel cell unit 11.

[3] In the above embodiment, SO ₂ , SO ₃ , and H ₂ S are exemplified as sulfur compounds to be removed by the sulfur compound removal filter 17, but the sulfur compounds to be removed by the sulfur compound removal filter 17 are not limited to these. do not have.

[4] In the above embodiment, the determination unit 27 determines that the voltage detected by the voltage detection unit 15 during operation after the sulfur compound removal filter is installed is higher than the voltage detected by the voltage detection unit 15 at the inspection timing. If the voltage is high, it is determined that the power generation performance of the fuel cell unit 11 is reduced due to the accumulation of sulfur compounds, but if the voltage detected by the voltage detection unit 15 during operation after the sulfur compound removal filter is It may be determined that the power generation performance of the fuel cell unit 11 is reduced due to the accumulation of sulfur compounds when the voltage is equal to or higher than the voltage detected by the voltage detection unit 15 at the inspection timing.

[5] In the above embodiment, the determination unit 27 compares the voltage detected at a predetermined inspection timing with the voltage detected after the sulfur compound removal filter 17 is attached, and determines whether the power generation performance of the fuel cell unit 11 is sulfur Although it is determined whether or not the decrease is due to accumulation of compounds, the present invention is not limited to this.
For example, when power generation operation is performed for a predetermined time after installing the sulfur compound removal filter 17, the rate of decrease in voltage (index value) during the period from the start of operation after installation until the elapse of a predetermined time is determined by the decrease in power generation performance of the fuel cell. If the problem is due to the accumulation of sulfur compounds in the part 11, it is better to install the sulfur compound removal filter 17 (the sulfur compounds are removed) than to install the sulfur compound removal filter 17 (the sulfur compounds are removed). (if not removed).
Therefore, for example, after installing the sulfur compound removal filter 17, power generation operation is performed while detecting the voltage, and the rate of decrease in voltage is calculated during the measurement period from the start of operation until a predetermined time (for example, 1000 hours) has elapsed (index The calculated voltage decrease rate is compared with a predetermined reference voltage decrease rate (standard index value decrease rate) to determine whether the power generation performance of the fuel cell unit 11 has decreased due to the accumulation of sulfur compounds. Alternatively, it may be determined whether the
Note that the reference voltage drop rate corresponds to the above measurement period for other fuel cell systems that are installed in the area that includes the installation location of the fuel cell system F that is the subject of inspection, and that do not have the sulfur compound removal filter 17 installed. period (for example, if the sulfur compound removal filter 17 is installed for fuel cell system F, which is the subject of inspection, when the cumulative operating time reaches 10,000 hours, and the sulfur compound removal filter 17 has been operated for 1,000 hours after that, other fuel cell systems The rate of decrease in voltage during a period in which the cumulative operating time of 10,000 hours to 11,000 hours can be exemplified.
Incidentally, the inventor of the present application conducted an experiment to verify how the power generation performance of the fuel cell section changes when a sulfur compound removal filter is attached to an actual fuel cell system. Specifically, an experiment was conducted in which power generation operation was performed for a certain period of time with air being supplied to the cathode, and then a sulfur compound removal filter was attached and power generation operation was performed for a certain period of time. FIG. 6 is a graph showing the results of this experiment, where the horizontal axis is the power generation operation time and the vertical axis is the voltage change rate (the predetermined time before the sulfur compound removal filter is attached is 100%). As can be seen from the figure, by installing the sulfur compound removal filter, the change in the voltage change rate is reduced. Specifically, the change in voltage change rate per 1000 hours before installing the sulfur compound removal filter was -0.217%, whereas the change in voltage change rate per 1000 hours after installing the sulfur compound removal filter was -0.217%. -0.032%. Therefore, by installing a sulfur compound removal filter on a normally operating fuel cell system that does not take measures such as removing sulfur compounds from the air with a filter, it is possible to reduce the performance deterioration of the fuel cell system. It was confirmed that this can be suppressed.

[6] In the above embodiment, from the viewpoint of preventing the performance of the sulfur compound removal filter from deteriorating by circulating the air from which relatively large impurities such as dust and dirt have been removed by the impurity removal filter 14 to the sulfur compound removal filter 17, In the filter installation process, the sulfur compound removal filter 17 is installed between the power generation oxygen blower 12 and the impurity removal filter 14, but this is not limited to this. The mounting position is not particularly limited as long as sulfur compounds can be removed from oxygen.

[7] The configurations disclosed in the above embodiments (including other embodiments) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction, and this specification The embodiments disclosed in this book are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the purpose of the present invention.

INDUSTRIAL APPLICATION This invention can be utilized for the method of inspecting the fuel cell system provided with the fuel cell part, and the method of determining the object to which a sulfur compound removal filter is attached using an inspection result.

11 Fuel cell section 14 Impurity removal filter 17 Sulfur compound removal filter L4 Oxygen supply path for power generation (supply path)
F Fuel cell system

Claims (8)

A method for inspecting a fuel cell system including a fuel cell section, the method comprising:
A first index for operating the fuel cell system by supplying fuel gas and air at a predetermined flow rate to the fuel cell section, and measuring an index value indicating power generation performance of the fuel cell section at a predetermined inspection timing. a value measurement process;
If the index value measured in the first index value measurement step is less than a predetermined reference index value, a sulfur compound removal filter is installed in the supply path that supplies air to the fuel cell section for removing sulfur compounds. The filter installation process,
After the filter attachment step, a second index value measurement step of supplying fuel gas and air to the fuel cell unit at a predetermined flow rate to operate the fuel cell system and measure the index value;
When the index value measured in the second index value measurement step is greater than or equal to the index value measured in the first index value measurement step, the fuel cell is reduced by accumulation of the sulfur compound in at least the fuel cell section. A fuel cell system inspection method includes a determination step of determining that the power generation performance of a portion of the fuel cell system is degraded. A method for inspecting a fuel cell system including a fuel cell section, the method comprising:
Index value measurement of supplying fuel gas and air to the fuel cell unit at a predetermined flow rate to operate the fuel cell system, and measuring an index value indicating power generation performance of the fuel cell unit at a predetermined inspection timing. process and
A filter in which a sulfur compound removal filter for removing sulfur compounds is attached to a supply path that supplies air to the fuel cell section when the index value measured in the index value measurement step is less than a predetermined reference index value. Installation process and
After the filter attachment step, the fuel cell system is operated by supplying fuel gas and air at a predetermined flow rate to the fuel cell unit, and the index value is measured, and the index value is measured at a predetermined rate from the start of operation after the filter attachment step. An index value decrease rate calculation step of calculating the decrease rate of the index value during the measurement period until time elapses;
If the rate of decrease in the index value regarding the fuel cell system calculated in the index value decrease rate calculation step is smaller than the reference index value decrease rate in the period corresponding to the measurement period, at least the A method for inspecting a fuel cell system, comprising a step of determining that the power generation performance of the fuel cell unit is degraded due to accumulation of sulfur compounds. The reference index value decline rate is the rate of decrease of the index value in a period corresponding to the measurement period of another fuel cell system installed in the area including the installation location of the fuel cell system and to which the sulfur compound removal filter is not installed. 3. The method for inspecting a fuel cell system according to claim 2, wherein the method is a rate of decrease. 4. The method for inspecting a fuel cell system according to claim 1, wherein the inspection timing is a timing at which the cumulative operating time of the fuel cell system reaches a predetermined time. 5. The method for inspecting a fuel cell system according to claim 1, wherein the index value is an output voltage of the fuel cell section. The method for inspecting a fuel cell system according to any one of claims 1 to 5, wherein the sulfur compound is one or more selected from the group consisting of SO ₂ , SO ₃ and H ₂ S. The fuel cell system is provided with an impurity removal filter for removing impurities in the supply path,
7. The method for inspecting a fuel cell system according to claim 1, wherein in the filter attachment step, the sulfur compound removal filter is attached closer to the fuel cell unit than the impurity removal filter. The fuel cell system inspection method according to any one of claims 1 to 7, wherein it is determined that the power generation performance of the fuel cell unit is reduced due to accumulation of the sulfur compound in at least the fuel cell unit. An installation target determination method that performs an installation target determination step of determining another fuel cell system installed in an area including an installation location of the fuel cell system as an installation target of the sulfur compound removal filter.

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