JP2020009544A - Fuel cell system and fuel cell ship - Google Patents

Abstract

To provide a technology of enabling a fuel cell system and a fuel cell ship comprising the same to safely and securely stop supply of fuel gas to a fuel cell device at the time of operation stop and prevent performance reduction caused by supplying air to the fuel cell device at the time of actuation.SOLUTION: A fuel cell system comprises: an upstream cutoff valve 11A and a downstream cutoff valve 11B provided in series on a supply path 10 to be capable of cutting off the supply path 10; a bleed valve 21 connected to a space 10B formed between the upstream cutoff valve 11A and downstream cutoff valve 11B on the supply path 10 to be capable of opening the space 10B to the outside; and valve control means 60 for controlling actuation of the bleed valve 21 in a form of closing the bleed valve 21 at the time of supplying fuel gas G1 and opening the bleed valve 21 at the time of stopping supply of fuel gas G1 and executing purge processing of supplying purge gas PG to the space 10B before starting supply of fuel gas G1 to purge the space 10B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel cell system that supplies fuel gas to a fuel cell device through a fuel gas supply path, and a fuel cell ship provided with the same.

  In a fuel cell system including a fuel cell device having a fuel cell stack that generates power by an electrochemical reaction of a fuel gas, hydrogen gas supplied to the fuel cell stack or hydrocarbon gas that becomes the hydrogen gas through reforming is used. Fuel gas is supplied from a fuel gas storage unit such as a cylinder to the anode side of the fuel cell device through a fuel gas supply path. In such a fuel cell system, the supply of the fuel gas to the fuel cell device is stopped by closing a shut-off valve provided in the fuel gas supply passage, and the operation is stopped (for example, Patent Document 1). See).

  When the operation of the fuel cell system is stopped, it is necessary to surely stop the supply of the fuel gas to the fuel cell device. In particular, since high safety standards are required for ships, fuel cell ships equipped with a fuel cell system as a power source reliably prevent leakage of fuel gas to the fuel cell device side due to poor shut-off of shut-off valves, etc. Is required.

  In a system for supplying a fuel gas from a fuel gas supply source to a fuel gas supply destination through a fuel gas supply path, a double block and bleed (hereinafter, referred to as “DBB”) is used as a configuration for reliably and safely shutting off the supply of the fuel gas. Is known. Such a DBB is provided with two shut-off valves in series with the fuel gas supply path, and is connected to a space between the two shut-off valves formed between the two shut-off valves, and is provided with a bleed valve capable of opening the space to the outside. It is provided and configured. The valve control means for controlling the operation of the two shut-off valves and the bleed valve closes the two shut-off valves and opens the bleed valve when the supply of fuel gas to the fuel cell device is stopped. Let it.

JP 2010-287320 A

  However, when the DBB is adopted in the above-described fuel cell system, the above-described bleed valve is closed and the two shut-off valves are opened to start supplying the fuel gas to the fuel cell device. Oxygen in the air existing in the space between the shut-off valves is supplied to the anode side of the fuel cell device. Then, there is a concern that the performance of the fuel cell device is reduced due to the deterioration of the reforming catalyst of the reformer, the generation of corrosion current of the fuel cell stack, and the like.

  In view of this situation, in a fuel cell system that supplies fuel gas to a fuel cell device through a fuel gas supply path and a fuel cell ship equipped with the same, the supply of fuel gas to the fuel cell device is stopped safely and reliably when the operation is stopped. It is another object of the present invention to provide a technique capable of preventing performance degradation due to air supply to a fuel cell device at the time of startup.

A first characteristic configuration of the fuel cell system according to the present invention includes a fuel cell device having a fuel cell stack that generates power by an electrochemical reaction of a fuel gas;
A fuel gas supply path for supplying fuel gas to the fuel cell device;
A shutoff valve provided in the fuel gas supply path and capable of shutting off the supply path;
The operation of the shut-off valve in a form in which the shut-off valve is closed to stop supplying fuel gas to the fuel cell device, and the shut-off valve is opened to start supplying fuel gas to the fuel cell device. And a valve control means for controlling the fuel cell system,
An upstream shutoff valve and a downstream shutoff valve that are provided in series with the fuel gas supply passage and that can shut off the supply passage are provided as the shutoff valve,
A bleed valve that is connected to a space between shutoff valves formed between the upstream shutoff valve and the downstream shutoff valve in the fuel gas supply path and can open the space to the outside,
The valve control means closes the bleed valve when fuel gas is supplied to the fuel cell device, and opens the bleed valve when supply of fuel gas to the fuel cell device is stopped. Controlling the operation and supplying a purge gas, which is at least one of a fuel gas and an inert gas, to the space between the shut-off valves before starting the supply of the fuel gas to the fuel cell device to purge the space between the shut-off valves. The purging process is performed.

Further, the characteristic configuration of the fuel cell ship according to the present invention includes a fuel cell system according to the present invention,
A fuel gas storage unit for storing fuel gas supplied to the fuel cell system,
The point is that the power generated by the fuel cell system is supplied to the power load in the ship.

According to this configuration, in a fuel cell system mounted on a fuel cell ship or the like that requires a high safety standard, an upstream shutoff valve and a downstream shutoff valve provided in series with a fuel gas supply path, and both the shutoff valves And a bleed valve connected to the inter-shut-off valve space formed between them.
When the operation of the fuel cell system is stopped, the upstream shutoff valve and the downstream shutoff valve are closed and the bleed valve is opened by valve control means for controlling the operation of the upstream shutoff valve and the downstream shutoff valve and the bleed valve. In the valve form, the supply of the fuel gas from the fuel gas supply source such as the fuel gas storage unit to the fuel cell device is stopped. By stopping the supply of the fuel gas in this way, even if a shut-off failure occurs in any of the upstream shut-off valve and the downstream shut-off valve, the fuel gas supply path and the fuel gas supply source side are not connected. The fuel cell device side can be isolated by the space between the shut-off valves opened to the outside such as the atmosphere. Therefore, it is possible to reliably prevent the leakage of the fuel gas from the fuel gas supply source to the fuel cell device due to the failure of the shut-off valve. Furthermore, the fuel gas that has flowed into the space between the shut-off valves when the supply of the fuel gas is stopped can be released to the outside via the bleed valve which is in an open state, and safety can be maintained.

  On the other hand, when the fuel cell system is started, the valve control means opens the upstream shut-off valve and the downstream shut-off valve and closes the bleed valve. The supply of fuel gas to the device can be started. Before the start of the supply of the fuel gas to the fuel cell device, the purge process is performed by the valve control unit. In this purging process, the purge gas containing substantially no air (oxygen) is supplied to the inter-shut-valve space to purge the inter-shut-valve space. Then, when the supply of the fuel gas is stopped, the air that has entered the space between the shut-off valves from the outside via the bleed valve that is open from the outside is appropriately removed by performing the above-described purge processing. Gas supply is started. As a result, it is possible to prevent performance degradation due to the supply of air to the anode side of the fuel cell device.

  Therefore, according to the present invention, in a fuel cell system for supplying a fuel gas to a fuel cell device through a fuel gas supply path, the fuel cell system can be safely and reliably stopped when the operation is stopped while the fuel cell It is possible to provide a technique capable of preventing performance degradation caused by supply of air to the device.

  According to a second characteristic configuration of the fuel cell system according to the present invention, in addition to the first characteristic configuration, the valve control unit performs the purge process for a fuel gas to the fuel cell device after performing a predetermined set purge time. The point is to start supplying.

  According to this configuration, the supply of the fuel gas to the fuel cell device is started after the purge process is performed by the valve control unit for the predetermined set purge time. Therefore, with a simple configuration, the supply of the fuel gas to the fuel cell device can be started after removing the air staying in the space between the shut-off valves. Further, the set purge time for executing the purge process can be appropriately set as a time during which air staying in the space between the shut-off valves can be almost completely removed. For example, the opening degree of each valve and the cutoff of each flow path can be set. The area, the supply pressure of the purge gas, and the like can be appropriately determined by experiments, simulations, and the like using the parameters.

  In a third characteristic configuration of the fuel cell system according to the present invention, in addition to any one of the first characteristic configuration and the second characteristic configuration, the valve control unit may open the bleed valve in the purge process. The purge gas supplied to the inter-shutoff valve space is discharged to the outside via the bleed valve.

  According to this configuration, the bleed valve that is opened when the supply of the fuel gas is stopped is maintained in the open state when the purge process is performed before the supply of the fuel gas to the fuel cell device is started. That is, in this purging process, the space between the shut-off valves can be purged in such a manner that the purge gas supplied to the space between the shut-off valves is discharged to the outside via the bleed valve in an open state. Thus, the supply of the fuel gas to the fuel cell device can be started after the air remaining particularly in the vicinity of the bleed valve in the space between the shutoff valves is almost completely removed.

  A fourth characteristic configuration of the fuel cell system according to the present invention, in addition to the third characteristic configuration, wherein the valve control unit opens the downstream side shut-off valve when the supply of the fuel gas to the fuel cell device starts. The point is that the bleed valve is closed later.

  According to this configuration, when the bleed valve is maintained in the open state during the execution of the purge process, the supply of the fuel gas to the fuel cell device is started by opening the downstream side shutoff valve after the execution of the purge process. After the downstream cutoff valve is opened, the bleed valve is closed. Then, since the downstream cutoff valve is in the open state when the bleed valve is closed, it is possible to suppress an excessive rise in the pressure of the fuel gas supply passage at the time of switching between opening and closing of the valve. Further, immediately after the downstream cutoff valve is opened, the purge gas supplied to the inter-shutoff valve space can be passed through both the bleed valve and the downstream cutoff valve. With this, it is possible to start the supply of the fuel gas to the fuel cell device after pushing out the air stagnating particularly in the vicinity of the bleed valve or the vicinity of the downstream side shutoff valve in the space between the shutoff valves with the purge gas from the space between the shutoff valves. it can.

  In a fifth aspect of the fuel cell system according to the present invention, in addition to any one of the first to fourth aspects, the valve control means may open the upstream shutoff valve in the purge process. The point is that fuel gas is supplied as the purge gas to the space between the shut-off valves via the upstream shut-off valve.

  According to this configuration, in the purge process performed before the supply of the fuel gas to the fuel cell device is started, the fuel gas can be used as the purge gas to be supplied to the space between the shut-off valves. That is, since the upstream shut-off valve is opened in the purging process, the fuel gas supplied to the fuel gas supply path is caused to flow into the inter-shut-valve space via the upstream shut-off valve as the purge gas, and the shut-off valve is opened. The interspace can be purged with fuel gas. With this, the supply of the fuel gas to the fuel cell device is started through the fuel gas supply path including the space between the shut-off valves in a state where the space between the shut-off valves is filled with the fuel gas by performing the purge process. It is possible to appropriately prevent performance degradation due to supply of air to the anode side of the fuel cell device.

A sixth characteristic configuration of the fuel cell system according to the present invention includes, in addition to the fifth characteristic configuration, a flow rate adjusting unit that can adjust a flow rate of the fuel gas in the fuel gas supply path,
The valve control means controls the flow rate adjusting means to change the flow rate of the fuel gas in the fuel gas supply path at the time of the purging process to the fuel gas flow rate in the fuel gas supply path during the normal operation of the fuel cell device. The point is that it is set smaller than the gas flow rate.

  According to this configuration, the purge process performed before the start of the supply of the fuel gas to the fuel cell device uses the fuel gas supplied to the fuel gas supply path via the upstream-side shut-off valve as the purge gas in the space between the shut-off valves. In the case of the inflow processing, the flow rate of the fuel gas in the fuel gas supply path during the execution of the purging processing is controlled by the flow rate adjustment means by the valve control means, so that the fuel gas supply path during the normal operation of the fuel cell device is controlled. Is set to be smaller than the flow rate of the fuel gas at. This suppresses an increase in fuel gas consumption due to the purging process, minimizes the amount of fuel gas released to the outside as the purge gas, and ensures that the concentration of fuel gas outside is kept below the explosion limit. Therefore, safety can be ensured.

A seventh characteristic configuration of the fuel cell system according to the present invention is the fuel cell system according to the fifth characteristic configuration or the sixth characteristic configuration, further comprising a downstream side provided on the fuel gas supply path downstream of the downstream side shutoff valve. An on-off valve,
A downstream relief valve that is connected to a downstream inter-valve space formed between the downstream shut-off valve and the downstream on-off valve in the fuel gas supply path and that can open the space to the outside,
In the purging process, the valve control unit closes the downstream open / close valve and opens the downstream shutoff valve and the downstream relief valve, thereby allowing the fuel gas supplied to the space between the shutoff valves to be opened. The point is that the fuel gas supplied to the downstream inter-valve space is supplied to the downstream inter-valve space via the downstream shut-off valve, and the fuel gas supplied to the downstream inter-valve space is discharged to the outside via the downstream relief valve.

  According to this configuration, in the purge process executed before the start of the supply of the fuel gas to the fuel cell device, the downstream open / close valve is closed, and the downstream shutoff valve and the downstream relief valve are opened. Therefore, in the purging process, the fuel gas that has flowed into the inter-valve space as a purge gas through the upstream side shut-off valve flows into the downstream inter-valve space through the downstream side shut-off valve, and then is discharged through the relief valve. The space between the shutoff valve and the space between the downstream valves can be purged by the fuel gas. Thus, the supply of the fuel gas to the fuel cell device can be started after the air staying particularly in the vicinity of the downstream side shutoff valve in the inter-shutoff valve space is almost completely removed.

  According to an eighth aspect of the fuel cell system according to the present invention, in addition to the seventh aspect, the valve control means opens the downstream side on-off valve when the supply of fuel gas to the fuel cell device is started. The point is that the downstream relief valve is closed later.

  According to this configuration, in a case where the purge process is performed in such a manner that the downstream-side on-off valve is closed and the downstream-side shutoff valve and the downstream-side relief valve are opened, the downstream-side on-off valve is opened after the purge process is performed. In starting the supply of the fuel gas to the fuel cell device by opening the valve, the downstream side on-off valve is opened, and then the downstream side relief valve is closed. Then, immediately after the downstream on-off valve is opened, the fuel gas serving as the purge gas supplied to the downstream inter-valve space can be passed through the downstream relief valve and the downstream on-off valve. With this, air remaining in the downstream inter-valve space, particularly near the downstream relief valve and the downstream on-off valve, is pushed out from the downstream inter-valve space by the fuel gas, and then the fuel gas is supplied to the fuel cell device. Can be started.

According to a ninth feature of the fuel cell system according to the present invention, in addition to any one of the first to eighth features, an inert gas is connected to the fuel gas supply passage and is connected to the fuel gas supply passage. An inert gas supply path capable of supplying
An inert gas supply valve provided in the inert gas supply path,
The valve control means is characterized in that, in the purging process, the inert gas supply valve is opened to supply an inert gas as the purge gas from the inert gas supply passage to the inter-shutoff valve space.

  According to this configuration, by providing the inert gas supply path and the inert gas supply valve, the purge gas is supplied to the space between the shut-off valves in the purge process performed before the start of the supply of the fuel gas to the fuel cell device. An inert gas such as a nitrogen gas can be used as the purge gas. That is, since the inert gas supply valve is opened in the purging process, the inert gas flows from the inert gas supply path into the fuel gas supply path as a purge gas through the inert gas supply valve, and the inert gas is supplied to the inert gas supply valve. The active gas can be caused to flow into the space between the shut-off valves, and the space between the shut-off valves can be purged with the inert gas. Accordingly, the supply of the fuel gas to the fuel cell device through the fuel gas supply path including the space between the shut-off valves is started in a state where the space between the shut-off valves is filled with the inert gas by performing the purge process. In addition, it is possible to appropriately prevent performance degradation due to supply of air to the anode side of the fuel cell device.

According to a tenth feature of the fuel cell system according to the present invention, in addition to the ninth feature, the inert gas supply passage is formed downstream of the fuel gas supply passage on a downstream side of the downstream shutoff valve. It is connected to the side space,
In the purge process, the valve control unit opens the inert gas supply valve and the downstream shutoff valve to inactivate the inert gas supply passage through the downstream space to the space between the shutoff valves. The point is to supply gas.

  According to this configuration, the inert gas supply path is connected to the downstream space formed on the downstream side of the downstream cutoff valve in the fuel gas supply path, and before the start of supply of the fuel gas to the fuel cell device, In the purge process to be executed, the inert gas supply valve and the downstream cutoff valve provided in the inert gas supply path are opened. Therefore, in the purging process, the inert gas supplied from the inert gas supply path to the downstream space as the purge gas is caused to flow into the inter-shut valve space via the downstream-side shut-off valve. It can be purged with an inert gas. Thus, the supply of the fuel gas to the fuel cell device can be started after the air staying particularly in the vicinity of the downstream side shutoff valve in the shutoff valve space is almost completely removed.

  According to an eleventh characteristic configuration of the fuel cell system according to the present invention, in addition to the tenth characteristic configuration, the valve control unit opens the upstream-side shut-off valve in the purging process to open the upstream-side shut-off valve. And supplying a fuel gas as the purge gas to the space between the shut-off valves via the intermittent valve.

  According to this configuration, in the purge process performed before the start of the supply of the fuel gas to the fuel cell device, the inert gas supplied to the downstream space as the purge gas is used as the purge gas as the purge gas via the downstream shutoff valve and the space between the shutoff valves. At the same time, the fuel gas supplied to the fuel gas supply path is caused to flow as a purge gas into the inter-shut valve space via the upstream side shut-off valve, and the inter-shut valve space is purged with both the inert gas and the fuel gas. can do. With this, air remaining in the vicinity of the upstream side shutoff valve and the vicinity of the downstream side shutoff valve in the space between the shutoff valves is almost completely removed with the fuel gas and the inert gas, and then the supply of the fuel gas to the fuel cell device is performed. You can start.

FIG. 2 is a block diagram illustrating a schematic configuration and an operation state of the fuel cell system according to the first embodiment. FIG. 2 is a block diagram showing a schematic configuration and an operation state of a fuel cell system according to a second embodiment. FIG. 2 is a block diagram showing a schematic configuration and an operation state of a fuel cell system according to a second embodiment. FIG. 6 is a block diagram showing a schematic configuration and an operating state of a fuel cell system according to a third embodiment FIG. 4 is a block diagram illustrating a schematic configuration and an operating state of a fuel cell system according to a fourth embodiment. Block diagram showing a schematic configuration of a fuel cell system according to another embodiment. Diagram showing a schematic configuration of a fuel cell ship

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIG.
The fuel cell system 50 shown in FIG. 1 includes a fuel cell device 40 having a fuel cell stack 41 that generates power by an electrochemical reaction of hydrogen gas (an example of a fuel gas), and a fuel that supplies hydrogen gas G1 to the fuel cell device 40. It is provided with a gas supply path 10, an operation control device 60 for controlling operation, and the like.
In the present embodiment, the fuel cell device 40 includes the fuel cell stack 41, and the hydrogen gas G1 is supplied from the fuel gas supply path 10 to the anode 41A of the fuel cell stack 41.

  The fuel gas supply path 10 is configured as a pipe connecting the hydrogen cylinder 1 (an example of a fuel gas storage unit) that stores the hydrogen gas G1 and the anode 41A of the fuel cell stack 41 of the fuel cell device 40. The fuel gas supply path 10 is provided with shutoff valves 11A and 11B, which are shutoff valves capable of shutting off the supply path 10. A flow control valve 25 (an example of a flow control unit) that can control the flow rate of the hydrogen gas G1 in the fuel gas supply path 10 is provided upstream of the shutoff valves 11A and 11B in the fuel gas supply path 10. Is provided.

  Then, the operation control device 60 closes the shutoff valves 11A and 11B to stop the supply of the hydrogen gas G1 to the fuel cell device 40, and opens the shutoff valves 11A and 11B to supply hydrogen to the fuel cell device 40. In a mode in which the supply of the gas G1 is started, it functions as a valve control unit that controls the operation of the shutoff valves 11A and 11B.

  That is, when the operation of the fuel cell system 50 is stopped, the power generation in the fuel cell stack 41 is stopped, and the shutoff valves 11A and 11B are closed by the operation control device 60, for example, as shown in FIG. The supply of the hydrogen gas G1 to the anode 41A of the fuel cell stack 41 is stopped. On the other hand, when the fuel cell system 50 is started, for example, as shown in FIG. 1D, the shutoff valves 11A and 11B are opened by the operation control device 60, so that hydrogen gas is supplied to the anode 41A of the fuel cell stack 41. The supply of G1 is started, and the power generation in the fuel cell stack 41 is started. Further, when the hydrogen gas G1 is supplied to the fuel cell device 40, the operation control device 60 adjusts the opening of the flow control valve 25 so that the flow rate of the hydrogen gas G1 in the fuel gas supply passage 10, in other words, the fuel cell device The supply amount of hydrogen gas G1 to 40 is set to a desired set supply amount during normal operation.

  As shown in FIG. 7, the fuel cell system 50 in the present embodiment is mounted on a fuel cell ship 100 as a power source. That is, the fuel cell ship 100 includes the fuel cell system 50 and the hydrogen cylinder 1 that stores the hydrogen gas G1 supplied to the fuel cell system 50, such as an electric motor 55 that rotationally drives a propeller 56 for propulsion. It is configured to supply the generated power of the fuel cell system 50 to the power load in the ship. In addition to the electric motor 55 for driving, the on-board auxiliary equipment (illustration omitted) such as lighting and a pump is used as the electric power load in the ship. Then, the fuel cell system 50 can be installed in the ship so as to supply the generated electric power to at least a part of the electric motor 55 and the incidental facilities. For example, the electric power generated by the fuel cell system 50 can be supplied to only the electric motor 55, only the auxiliary equipment, or both the electric motor 55 and the auxiliary equipment.

As described above, in the fuel cell system 50 mounted on the fuel cell ship 100, it is required to surely prevent the leakage of the hydrogen gas G1 to the fuel cell device 40 due to the failure of the shutoff valves 11A and 11B. You.
Therefore, in the fuel cell system 50 of the present embodiment, when supplying the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 through the fuel gas supply path 10, a configuration for reliably and safely shutting off the supply of the hydrogen gas G1. DBB (Double Block and Bleed) is adopted as an example.

  In the DBB, an upstream shutoff valve 11A and a downstream shutoff valve 11B that are provided in series with the fuel gas supply passage 10 and that can shut off the supply passage 10 are provided as the shutoff valves 11A and 11B. Further, a bleed which is connected to a space 10B between the shutoff valves formed between the upstream shutoff valve 11A and the downstream shutoff valve 11B in the fuel gas supply passage 10 and can open the space 10B to the atmosphere (an example of the outside). A valve 21 is provided. That is, the bleed valve 21 is configured as an on-off valve provided in the branch passage 20 that branches from the inter-valve space 10B of the fuel gas supply passage 10 and communicates with the atmosphere.

  Then, the operation control device 60 supplies the hydrogen gas G1 to the fuel cell device 40 by opening the shut-off valves 11A and 11B to generate power in the fuel cell device 40, as shown in FIG. During normal operation, the bleed valve 21 is kept closed. On the other hand, as shown in FIG. 1A, the operation control device 60 closes the shutoff valves 11A and 11B to stop the supply of the hydrogen gas G1 to the fuel cell device 40, and When the operation is stopped to stop the power generation, the bleed valve 21 is opened.

  That is, when the operation is stopped, the upstream cutoff valve 11A and the downstream cutoff valve 11B are closed with the inter-cutoff valve space 10B opened to the atmosphere, and the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped. You. Thus, even if a failure in shut-down occurs in any of the upstream shut-off valve 11A and the downstream shut-off valve 11B, the side of the hydrogen cylinder 1 and the side of the fuel cell device 40 in the fuel gas supply passage 10 are connected. The space between the shutoff valves 10B opened to the atmosphere is isolated. Therefore, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 due to the poor shutoff of the shutoff valves 11A and 11B is reliably prevented. Further, the hydrogen gas G1 that has flowed into the inter-shut valve space 10B when the operation is stopped is released to the atmosphere via the bleed valve 21 which is in an open state, so that safety is maintained.

  In the fuel cell system 50 employing the DBB, as shown in FIG. 1A, when the operation is stopped, air enters the inter-valve space 10B through the branch passage 20. Then, when the fuel cell system 50 starts to supply the hydrogen gas G1 to the fuel cell device 40, when oxygen in the air existing in the inter-shut valve space 10B is supplied to the anode 41A side of the fuel cell device 40. In addition, there is a problem that the performance of the fuel cell device 40 is deteriorated due to the occurrence of corrosion current of the fuel cell stack 41 and the like.

  Thus, in the fuel cell system 50 of the present embodiment, at the time of start-up in which the operation shifts from the operation stop state to the normal operation, performance degradation due to the supply of air to the fuel cell device 40 is prevented. To this end, a purge gas PG substantially containing no air (oxygen) is supplied to the inter-shut-valve space 10B before the supply of the hydrogen gas G1 to the fuel cell device 40 is started. A purge process for purging the space 10B is executed by the operation control device 60. That is, if such a purge process is performed before the supply of the hydrogen gas G1 to the fuel cell device 40 is started, the air that has entered the inter-valve space 10B is appropriately removed from the fuel gas supply passage 10. Then, the supply of the hydrogen gas G1 to the fuel cell device 40 is started. This prevents performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41.

The detailed configuration of the purging process in the present embodiment will be described below together with the details of the state change in the fuel gas supply path 10 at the time of starting the operation of the fuel cell system 50 of the present embodiment.
In the fuel cell system 50 of the present embodiment, at the time of startup, the state of the fuel gas supply path 10 is changed to a supply stopped state (see FIG. 1A), a purge state by valve control performed by the operation control device 60. (See FIG. 1B), the transition state (see FIG. 1C), and the supply continuation state (see FIG. 1D). Hereinafter, each state will be described in detail.

(Supply stopped)
FIG. 1A shows a supply stopped state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped when the operation of the fuel cell system 50 is stopped.
In this supply stop state, the upstream shutoff valve 11A and the downstream shutoff valve 11B are closed, and the bleed valve 21 is opened.

Then, with respect to the upstream space 10A formed on the fuel gas supply path 10 upstream of the upstream cutoff valve 11A and leading to the hydrogen cylinder 1, the hydrogen gas flowing in the supply continuation state before the supply was stopped is stopped. G1 is satisfied. Also, the downstream space 10C formed downstream of the downstream shutoff valve 11B in the fuel gas supply passage 10 and leading to the fuel cell device 40 also flows in the supply continuation state before the supply was stopped. The gas G1 is filled. On the other hand, the space 10B between the shutoff valves formed between the upstream shutoff valve 11A and the downstream shutoff valve 11B in the fuel gas supply passage 10 is opened to the atmosphere through the bleed valve 21 in the open state. As a result, air entering from the atmosphere is present.
By stopping the supply of the hydrogen gas G1 to the fuel cell device 40 in this manner, as described above, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 is reliably prevented, and the safety is improved. Nature is maintained.

(Purge state)
The operation control device 60 executes a purge process before starting supply of the hydrogen gas G1 to the fuel cell device 40. FIG. 1B shows a purge state, which is a state of the fuel gas supply path 10 when the purge process is performed. That is, when the fuel cell system 50 is activated, the purge process is executed, so that the state of the fuel gas supply path 10 is changed from the supply stop state to the purge state.

  In transition from the supply stop state to the purge state, the downstream side shutoff valve 11B is maintained in the closed state, and the upstream side shutoff valve 11A is opened while the bleed valve 21 is maintained in the open state. . Then, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied as the purge gas PG to the inter-shut-valve space 10B via the opened upstream-side shut-off valve 11A. At the same time, the hydrogen gas G1 supplied to the inter-shut valve space 10B is discharged to the outside through the branch passage 20 via the bleed valve 21 maintained in the open state. Then, in such a manner, the inter-shut-valve space 10B is purged by the hydrogen gas G1. That is, in the present embodiment, the hydrogen gas G1 is used as the purge gas PG to be supplied to the inter-shut valve space 10B, and the inter-shut valve space 10B is purged by the hydrogen gas G1.

  When such a purging process is performed, air that has entered the inter-valve interspace 10B from the atmosphere through the bleed valve 21 in the supply stopped state is released to the atmosphere through the bleed valve 21 of the branch passage 20. , From the fuel gas supply path 10. Then, by starting to supply the hydrogen gas G1 to the fuel cell device 40 following this state, performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41 is prevented.

  The operation control device 60 controls the flow control valve 25 to change the flow rate of the hydrogen gas G1 in the fuel gas supply passage 10 during the purge process to the hydrogen gas G1 in the fuel gas supply passage 10 during the normal operation of the fuel cell device 40. It is set smaller than the flow rate of the gas G1. In other words, the supply amount of the hydrogen gas G1 to the shutoff valve space 10B in the purge state and the transition state described later is set to be smaller than the set supply amount of the hydrogen gas G1 to the fuel cell device 40 in the supply continuation state described later. Is done. This suppresses an increase in the consumption of the hydrogen gas G1 consumed as the purge gas PG by the purge process. Further, the amount of the hydrogen gas G1 released into the atmosphere through the branch passage 20 is reduced, and the concentration of the hydrogen gas G1 in the atmosphere is reliably maintained below the explosion limit, thereby ensuring safety.

  In addition, the operation control device 60 sets the execution time of the purge process to an appropriate set purge time as a time during which air staying in the inter-shut valve space 10B can be almost completely removed. The appropriate set purge time can be determined as appropriate by experiments, simulations, or the like using, for example, the opening degree of each valve, the cross-sectional area and flow path length of each flow path, the supply pressure of the hydrogen gas G1, and the like as parameters. Also, an oxygen concentration sensor for measuring the oxygen concentration in the inter-shut-valve space 10B is provided, and the purge process is performed until the oxygen concentration measured by the oxygen concentration sensor becomes 0 or a fixed value or less. No problem.

  In the fuel cell system 50 of the present embodiment, the position of the downstream side shutoff valve 11 </ b> B in the fuel gas supply path 10 is disposed close to the branch to the branch path 20. That is, the downstream shutoff valve 11B is arranged so that the space between the branch to the branch passage 20 and the downstream shutoff valve 11B in the inter-shutoff valve space 10B is as small as possible. Accordingly, in the purge process, when the hydrogen gas G1 as the purge gas PG flows through the inter-shut-valve space 10B in the form of flowing into the branch passage 20 from the upstream-side shut-off valve 11A side, the vicinity of the downstream-side shut-off valve 11B Residual air is suppressed.

(Transition state)
At the start of the supply of the hydrogen gas G1 to the fuel cell device 40 at the end of the purging process, the operation control device 60 closes the bleed valve 21 after opening the downstream cutoff valve 11B. FIG. 1C shows a transition state, which is the state of the fuel gas supply path 10 at this time. That is, when the purge process is completed at the time of starting the fuel cell system 50, the state of the fuel gas supply path 10 transitions from the purge state to this transition state.

  In transition from the purge state to the transition state, the downstream side shutoff valve 11B is opened while the upstream side shutoff valve 11A and the bleed valve 21 are maintained in the open state. Then, the hydrogen gas G1 supplied to the inter-shut-valve space 10B via the upstream-side shut-off valve 11A passes through both the bleed valve 21 and the downstream-side shut-off valve 11B immediately after the downstream-side shut-off valve 11B is opened. become. Thus, the supply of the hydrogen gas G1 to the fuel cell device 40 in a state in which the air staying particularly in the vicinity of the bleed valve 21 or in the vicinity of the downstream side shutoff valve 11B in the space 10B between the shutoff valves is pushed out from the space 10B between the shutoff valves. Will be started. Further, when the bleed valve 21 is closed in the subsequent supply continuation state, since the downstream side shutoff valve 11B is in the open state, the excessive pressure increase in the fuel gas supply passage 10 when the bleed valve 21 is closed. Is suppressed.

(Supply continued)
FIG. 1D illustrates a supply continuation state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is continued during the normal operation in which the fuel cell system 50 is operated. That is, when the fuel cell system 50 is started, the state of the fuel gas supply path 10 changes from the transition state to the supply continuation state.

  When transitioning from the transition state to the supply continuation state, the bleed valve 21 is closed while the upstream cutoff valve 11A and the downstream cutoff valve 11B are maintained in the open state. Then, the release of the hydrogen gas G1 to the atmosphere via the bleed valve 21 is stopped. In this state, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied to the fuel cell device 40 via the upstream-side shutoff valve 11A and the downstream-side shutoff valve 11B, and the fuel cell device 40 performs desired power generation. Will be Then, at the time of the transition to the supply continuation state, since the purge processing has been executed in advance, the fuel gas supply path 10 is in a state filled with hydrogen gas G1 without air. Therefore, performance degradation due to the supply of air to the fuel cell device 40 is suitably prevented.

  In this embodiment, at the end of the purge process at the start of the supply of the hydrogen gas G1 to the fuel cell device 40, the bleed valve 21 is closed after the downstream side shutoff valve 11B is opened, and the fuel gas supply path 10 Was changed from the purge state (see FIG. 1 (b)) to the supply continuation state (see FIG. 1 (d)) via the transition state (see FIG. 1 (c)). However, the opening / closing timing of the downstream side shutoff valve 11B, the bleed valve 21, and the like can be appropriately changed. For example, by closing the bleed valve 21 at the same time as or immediately before the opening of the downstream side shutoff valve 11B, the state of the fuel gas supply path 10 is directly changed from the purge state (see FIG. 1B) to the continuous supply state. (See FIG. 1D).

[Second embodiment]
A second embodiment of the present invention will be described with reference to FIGS.
In addition, about the structure similar to embodiment mentioned above, detailed description may be omitted.
The fuel cell system 50 shown in FIGS. 2 and 3 includes a fuel cell device 40, a fuel gas supply path 10, an operation control device 60, and the like, similarly to the above-described embodiment. The hydrogen gas G1 is supplied to the anode 41A of the 41.
Further, the fuel cell system 50 of the present embodiment employs a DBB (double block and bleed) composed of an upstream shutoff valve 11A, a downstream shutoff valve 11B, and a bleed valve 21, similarly to the above-described embodiment. ing.

  Further, the fuel gas supply passage 10 is provided with a downstream opening / closing valve 13 downstream of the downstream shutoff valve 11B. Further, a downstream relief valve 23 connected to a downstream inter-valve space 10C1 formed between the downstream shutoff valve 11B and the downstream on-off valve 13 in the fuel gas supply passage 10 to open the space 10C to the outside. Is provided. That is, the downstream relief valve 23 is configured as an on-off valve provided in the branch passage 22 that branches off from the downstream inter-valve space 10C1 of the fuel gas supply passage 10 and communicates with the atmosphere.

  Then, the operation control device 60 supplies the hydrogen gas G1 to the fuel cell device 40 by opening the shut-off valves 11A and 11B to generate power in the fuel cell device 40, as shown in FIG. During normal operation, the downstream on-off valve 13 is opened, and the bleed valve 21 and the downstream relief valve 23 are closed. On the other hand, the operation control device 60 closes the shutoff valves 11A and 11B to stop the supply of the hydrogen gas G1 to the fuel cell device 40 as shown in FIG. When the operation for stopping the power generation is stopped, the bleed valve 21 is opened, the downstream opening / closing valve 13 is closed, and the downstream relief valve 23 is closed. At this time, even if the shut-off valve 11B fails and air in the inter-shut-valve space 10B leaks to the downstream side of the shut-off valve 11B, if the downstream on-off valve 13 is in the closed state, air flows into the fuel cell device 40. Is prevented. Further, even if the bleed valve 23 fails and air flows into the downstream inter-valve space 10C1 from the atmosphere side, if the downstream on-off valve 13 is in the closed state, air is prevented from flowing into the fuel cell device 40. You. When the operation is stopped, the downstream opening / closing valve 13 may be opened.

  That is, when the operation is stopped, the upstream cutoff valve 11A and the downstream cutoff valve 11B are closed with the inter-cutoff valve space 10B opened to the atmosphere, and the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped. You. Thus, even if a failure in shut-down occurs in any of the upstream shut-off valve 11A and the downstream shut-off valve 11B, the side of the hydrogen cylinder 1 and the side of the fuel cell device 40 in the fuel gas supply passage 10 are connected. The space between the shutoff valves 10B opened to the atmosphere is isolated. Therefore, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 due to the poor shutoff of the shutoff valves 11A and 11B is reliably prevented. Further, the hydrogen gas G1 that has flowed into the inter-shut valve space 10B when the operation is stopped is released to the atmosphere via the bleed valve 21 which is in an open state, so that safety is maintained.

  Furthermore, in the fuel cell system 50 according to the present embodiment, at the time of start-up in which the operation shifts from the operation stop state to the normal operation, performance degradation due to the supply of air to the fuel cell device 40 is prevented. To this end, a purge gas PG substantially containing no air (oxygen) is supplied to the inter-shut-valve space 10B before the supply of the hydrogen gas G1 to the fuel cell device 40 is started. A first purge process and a second purge process as purge processes for purging the space 10B are executed by the operation control device 60. That is, if such a purge process is performed before the supply of the hydrogen gas G1 to the fuel cell device 40 is started, the air that has entered the inter-valve space 10B is appropriately removed from the fuel gas supply passage 10. Then, the supply of the hydrogen gas G1 to the fuel cell device 40 is started. This prevents performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41.

The detailed configuration of the purging process in the present embodiment will be described below together with the details of the state change in the fuel gas supply path 10 at the time of starting the operation of the fuel cell system 50 of the present embodiment.
Note that, in the fuel cell system 50 of the present embodiment, the state of the fuel gas supply passage 10 is changed to a supply stopped state (see FIG. 2A) by the valve control performed by the operation control device 60 at the time of startup. Purge state (see FIG. 2B), second purge state (see FIG. 2C), transition state (see FIG. 3D), supply continuation state (see FIG. 3E) It changes in order. Hereinafter, each state will be described in detail.

(Supply stopped)
FIG. 2A shows a supply stopped state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped when the operation of the fuel cell system 50 is stopped.
In this supply stop state, the upstream shutoff valve 11A and the downstream shutoff valve 11B are closed, and the bleed valve 21 is opened. Further, in the supply stop state, the downstream opening / closing valve 13 is closed, and the downstream relief valve 23 is closed.

Then, with respect to the upstream space 10A formed on the fuel gas supply path 10 upstream of the upstream cutoff valve 11A and leading to the hydrogen cylinder 1, the hydrogen gas flowing in the supply continuation state before the supply was stopped is stopped. G1 is satisfied. Further, the downstream spaces 10C1 and 10C2 formed downstream of the downstream cutoff valve 11B in the fuel gas supply passage 10 and leading to the fuel cell device 40 also flow in the supply continuation state before the supply is stopped. The hydrogen gas G1 is filled. On the other hand, the space 10B between the shutoff valves formed between the upstream shutoff valve 11A and the downstream shutoff valve 11B in the fuel gas supply passage 10 is opened to the atmosphere through the bleed valve 21 in the open state. As a result, air entering from the atmosphere is present.
By stopping the supply of the hydrogen gas G1 to the fuel cell device 40 in this manner, as described above, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 is reliably prevented, and the safety is improved. Nature is maintained.

(First purge state)
The operation control device 60 executes a first purge process and a second purge process in order as a purge process before starting supply of the hydrogen gas G1 to the fuel cell device 40. FIG. 2B illustrates a first purge state, which is a state of the fuel gas supply path 10 when the first purge process is performed. That is, when the fuel cell system 50 is started, the state of the fuel gas supply path 10 is changed from the supply stop state to the first purge state by executing the first purge process.

  In transition from the supply stop state to the first purge state, the downstream shutoff valve 11B and the downstream relief valve 23 are maintained in the closed state, and the bleed valve 21 and the downstream on / off valve 13 are maintained in the open state. The upstream shut-off valve 11A and the downstream shut-off valve 13 are opened while being kept. Then, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied as the purge gas PG to the inter-shut-valve space 10B via the opened upstream-side shut-off valve 11A. At the same time, the hydrogen gas G1 supplied to the inter-shut valve space 10B is discharged to the outside through the branch passage 20 via the bleed valve 21 maintained in the open state. Then, in such a manner, the inter-shut-valve space 10B is purged by the hydrogen gas G1. That is, in the present embodiment, the hydrogen gas G1 is used as the purge gas PG to be supplied to the inter-shut valve space 10B, and the inter-shut valve space 10B and the like are purged by the hydrogen gas G1.

  When the first purge process is performed, the air that has entered the inter-shut valve space 10B from the atmosphere via the bleed valve 21 in the supply stopped state is released to the atmosphere via the bleed valve 21 of the branch passage 20. Then, it is removed from the inter-shut valve space 10B.

  In addition, the operation control device 60 sets the execution time of the first purge process to a first set purge time that is appropriate as a time during which the air staying in the inter-shut valve space 10B can be almost completely removed. The appropriate set first purge time can be determined as appropriate by experiments, simulations, or the like using, for example, the opening degree of each valve, the cross-sectional area and length of each flow path, the supply pressure of the hydrogen gas G1, and the like as parameters. Also, an oxygen concentration sensor for measuring the oxygen concentration in the inter-shut-valve space 10B is provided, and the purge process is performed until the oxygen concentration measured by the oxygen concentration sensor becomes 0 or a fixed value or less. No problem.

(Second purge state)
FIG. 2C shows a purge state, which is a state of the fuel gas supply passage 10 when the second purge process is performed. That is, when the fuel cell system 50 is started up, the state of the fuel gas supply passage 10 changes from the first purge state to the second purge state by executing the second purge processing.

  In the transition from the first purge state to the second purge state, the downstream relief valve 23 is maintained in the closed state, and the downstream shutoff valve 11A and the bleed valve 21 are maintained in the open state. After the side opening / closing valve 13 is closed and the downstream side relief valve 23 is opened, the downstream side shutoff valve 11B is opened. Then, the hydrogen gas G1 as the purge gas PG is supplied from the inter-shut-valve space 10B to the downstream inter-valve space 10C1 via the opened downstream side shut-off valve 11B. At the same time, the hydrogen gas G1 supplied to the downstream inter-valve space 10C1 is discharged outside through the branch passage 22 via the downstream relief valve 23 maintained in the open state. In this manner, the inter-shut-valve space 10B and the downstream inter-valve space 10C1 are purged by the hydrogen gas G1.

  When the second purge process is performed, the air remaining near the downstream side shutoff valve 11B in the inter-shut valve space 10B even after the execution of the first purge process is reduced to the downstream inter-valve space 10C1. The fuel gas is released to the atmosphere through the downstream relief valve 23 of the branch passage 22 and is removed from the fuel gas supply passage 10. Then, by starting to supply the hydrogen gas G1 to the fuel cell device 40 following this state, performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41 is prevented.

  In addition, the operation control device 60 sets the execution time of the second purge process to an appropriate set second purge time as a time during which air staying in the downstream inter-valve space 10C1 can be almost completely removed. The appropriate setting second purge time can be determined as appropriate by experiments, simulations, and the like using, for example, the opening degree of each valve, the cross-sectional area and length of each flow path, the supply pressure of the hydrogen gas G1, and the like as parameters. Further, an oxygen concentration sensor for measuring the oxygen concentration in the downstream inter-valve space 10C1 is provided, and the purge process is executed until the oxygen concentration measured by the oxygen concentration sensor becomes 0 or a fixed value or less. It does not matter.

(Transition state)
At the start of the supply of the hydrogen gas G1 to the fuel cell device 40 at the end of the second purge process, the operation control device 60 closes the downstream relief valve 23 after the downstream on-off valve 13 is opened. FIG. 3D shows a transition state, which is the state of the fuel gas supply path 10 at this time. That is, when the purge process is completed at the time of activation of the fuel cell system 50, the state of the fuel gas supply path 10 transitions from the second purge state to this transition state.

  In the transition from the second purge state to the transition state, the downstream shut-off valve 13 is opened while the upstream shut-off valve 11A, the downstream shut-off valve 11B, and the downstream relief valve 23 are kept open. At the same time, the bleed valve 21 is closed. Then, the hydrogen gas G1 supplied to the downstream inter-valve space 10C1 via the upstream cut-off valve 11A and the downstream cut-off valve 11B immediately after the downstream cut-off valve 11B is opened, the downstream relief valve 23 and the downstream It passes through both of the on-off valves 13. As a result, the air remaining in the downstream inter-valve space 10C1 particularly near the downstream relief valve 23 and the downstream on-off valve 13 is pushed out of the downstream inter-valve space 10C1 and the hydrogen is transferred to the fuel cell device 40. The supply of the gas G1 is started. Further, when the downstream side relief valve 23 is closed in the subsequent supply continuation state, since the downstream side on-off valve 13 is in the open state, the fuel gas supply path 10 when the downstream side relief valve 23 is closed is closed. Excessive pressure rise is suppressed.

(Supply continued)
FIG. 3E illustrates a supply continuation state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is continued during the normal operation in which the fuel cell system 50 is operated. That is, when the fuel cell system 50 is started, the state of the fuel gas supply path 10 changes from the transition state to the supply continuation state.

  In the transition from the transition state to the supply continuation state, the downstream release valve 23 is closed while the upstream cutoff valve 11A, the downstream cutoff valve 11B, and the downstream on-off valve 13 are maintained in the open state. . Then, the release of the hydrogen gas G1 to the atmosphere via the downstream relief valve 23 is stopped. In this state, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied to the fuel cell device 40 via the upstream cutoff valve 11A, the downstream cutoff valve 11B, and the downstream open / close valve 13, and the fuel cell device 40 At 40, the desired power generation is performed. Since the first purge process and the second purge process are performed in advance at the time of transition to the supply continuation state, the fuel gas supply path 10 is filled with the hydrogen gas G1 without air. Has become. Therefore, performance degradation due to the supply of air to the fuel cell device 40 is suitably prevented.

  In the present embodiment, when the purge process at the start of the supply of the hydrogen gas G1 to the second fuel cell device 40 is completed, the downstream relief valve 23 is closed after the downstream on-off valve 13 is opened, and the fuel is discharged. The state of the gas supply path 10 is changed from the second purge state (see FIG. 2C) to a supply continuation state (see FIG. 3E) through a transition state (see FIG. 3D). . However, the opening / closing timing of the downstream side opening / closing valve 13 and the downstream side relief valve 23 can be appropriately changed. For example, the state of the fuel gas supply path 10 is changed from the second purge state (see FIG. 2C) by closing the downstream relief valve 23 at the same time as or immediately before the opening of the downstream on-off valve 13. It may be configured to make a transition directly to the continuous supply state (see FIG. 3E).

[Third embodiment]
A third embodiment of the present invention will be described with reference to FIG.
In addition, about the structure similar to embodiment mentioned above, detailed description may be omitted.
The fuel cell system 50 illustrated in FIG. 4 includes the fuel cell device 40, the fuel gas supply path 10, the operation control device 60, and the like, as in the above-described embodiment. Hydrogen gas G1 is supplied to 41A.
Further, the fuel cell system 50 of the present embodiment employs a DBB (double block and bleed) composed of an upstream shutoff valve 11A, a downstream shutoff valve 11B, and a bleed valve 21, similarly to the above-described embodiment. ing.
Further, the fuel gas supply passage 10 is provided with a downstream opening / closing valve 13 downstream of the downstream shutoff valve 11B.

  A nitrogen gas supply path 31 (an example of an inert gas supply path) connected to the fuel gas supply path 10 and capable of supplying a nitrogen gas NG (an example of an inert gas) is provided in the fuel gas supply path 10. The nitrogen gas supply passage 31 is formed in a downstream space formed downstream of the downstream cutoff valve 11B in the fuel gas supply passage 10, specifically, with the downstream cutoff valve 11B in the fuel gas supply passage 10 and the downstream opening / closing. It is connected to a downstream inter-valve space 10C1 formed between the valve 13 and the valve 13. In other words, the nitrogen gas supply path 31 is configured as a pipe connecting the nitrogen gas cylinder 30 that stores the nitrogen gas NG and the downstream inter-valve space 10C1 in the fuel gas supply path 10. In this embodiment, the nitrogen gas NG is used as the inert gas, but another inert gas may be used.

  The nitrogen gas supply path 31 is provided with a nitrogen gas supply valve 32 (an example of an inert gas supply valve). The operation control device 60 controls the opening and closing operation of the nitrogen gas supply valve 32 to interrupt the supply of the nitrogen gas NG from the nitrogen gas supply path 31 to the downstream inter-valve space 10C1 of the fuel gas supply path 10. Can be.

  Then, as shown in FIG. 4C, the operation control device 60 opens the shut-off valves 11A and 11B to supply the hydrogen gas G1 to the fuel cell device 40 to generate power in the fuel cell device 40. During normal operation, the downstream side on-off valve 13 is opened, and the bleed valve 21 and the nitrogen gas supply valve 32 are closed. On the other hand, the operation control device 60 closes the shutoff valves 11A and 11B to stop the supply of the hydrogen gas G1 to the fuel cell device 40 as shown in FIG. When the operation for stopping power generation is stopped, the bleed valve 21 is opened, the downstream opening / closing valve 13 is opened, and the nitrogen gas supply valve 32 is closed.

  That is, when the operation is stopped, the upstream cutoff valve 11A and the downstream cutoff valve 11B are closed with the inter-cutoff valve space 10B opened to the atmosphere, and the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped. You. Thus, even if a failure in shut-down occurs in any of the upstream shut-off valve 11A and the downstream shut-off valve 11B, the side of the hydrogen cylinder 1 and the side of the fuel cell device 40 in the fuel gas supply passage 10 are connected. The space between the shutoff valves 10B opened to the atmosphere is isolated. Therefore, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 due to the poor shutoff of the shutoff valves 11A and 11B is reliably prevented. Further, the hydrogen gas G1 that has flowed into the inter-shut valve space 10B when the operation is stopped is released to the atmosphere via the bleed valve 21 which is in an open state, so that safety is maintained.

  Furthermore, in the fuel cell system 50 according to the present embodiment, at the time of start-up in which the operation shifts from the operation stop state to the normal operation, performance degradation due to the supply of air to the fuel cell device 40 is prevented. To this end, a purge gas PG substantially containing no air (oxygen) is supplied to the inter-shut-valve space 10B before the supply of the hydrogen gas G1 to the fuel cell device 40 is started. A purge process for purging the space 10B is executed by the operation control device 60. That is, if such a purge process is performed before the supply of the hydrogen gas G1 to the fuel cell device 40 is started, the air that has entered the inter-valve space 10B is appropriately removed from the fuel gas supply passage 10. Then, the supply of the hydrogen gas G1 to the fuel cell device 40 is started. This prevents performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41.

The detailed configuration of the purging process in the present embodiment will be described below together with the details of the state change in the fuel gas supply path 10 at the time of starting the operation of the fuel cell system 50 of the present embodiment.
In the fuel cell system 50 according to the present embodiment, at the time of startup, the state of the fuel gas supply path 10 is changed to a supply stopped state (see FIG. 4A) and a purge state by valve control performed by the operation control device 60. (See FIG. 4B) and the supply continuation state (see FIG. 4C). Hereinafter, each state will be described in detail.

(Supply stopped)
FIG. 4A shows a supply stopped state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped when the operation of the fuel cell system 50 is stopped.
In this supply stop state, the upstream shutoff valve 11A and the downstream shutoff valve 11B are closed, and the bleed valve 21 is opened. Further, in this supply stopped state, the downstream opening / closing valve 13 is opened and the nitrogen gas supply valve 32 is closed.

Then, with respect to the upstream space 10A formed on the fuel gas supply path 10 upstream of the upstream cutoff valve 11A and leading to the hydrogen cylinder 1, the hydrogen gas flowing in the supply continuation state before the supply was stopped is stopped. G1 is satisfied. Further, the downstream spaces 10C1 and 10C2 formed downstream of the downstream cutoff valve 11B in the fuel gas supply passage 10 and leading to the fuel cell device 40 also flow in the supply continuation state before the supply is stopped. The hydrogen gas G1 is filled. On the other hand, the space 10B between the shutoff valves formed between the upstream shutoff valve 11A and the downstream shutoff valve 11B in the fuel gas supply passage 10 is opened to the atmosphere through the bleed valve 21 in the open state. As a result, air entering from the atmosphere is present.
By stopping the supply of the hydrogen gas G1 to the fuel cell device 40 in this manner, as described above, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 is reliably prevented, and the safety is improved. Nature is maintained.

(Purge state)
The operation control device 60 executes a purge process before starting supply of the hydrogen gas G1 to the fuel cell device 40. FIG. 4B shows a purge state, which is a state of the fuel gas supply path 10 when the purge process is performed. That is, when the fuel cell system 50 is activated, the purge process is executed, so that the state of the fuel gas supply path 10 is changed from the supply stop state to the purge state.

  When transitioning from the supply stop state to the purge state, the downstream shut-off valve 13 is closed while the upstream shutoff valve 11A is kept closed and the bleed valve 21 is kept open. In addition, the downstream side shutoff valve 11B and the nitrogen gas supply valve 32 are opened. Then, the nitrogen gas NG supplied from the nitrogen gas cylinder 30 is supplied as the purge gas PG to the downstream side inter-valve space 10C1 via the opened nitrogen gas supply valve 32, and the nitrogen gas NG is supplied to the downstream opening valve. The purge gas PG is supplied to the inter-shutoff valve space 10B via the side shutoff valve 11B. At the same time, the nitrogen gas NG supplied to the inter-shut valve space 10B is discharged to the outside through the branch passage 20 via the bleed valve 21 maintained in the open state. And in such a form, the space 10B between the shutoff valves is purged by the nitrogen gas NG. That is, in the present embodiment, the nitrogen gas NG is used as the purge gas PG supplied to the inter-shut valve space 10B, and the inter-shut valve space 10B and the like are purged by the nitrogen gas NG.

  When such a purging process is performed, air that has entered the inter-valve interspace 10B from the atmosphere through the bleed valve 21 in the supply stopped state is released to the atmosphere through the bleed valve 21 of the branch passage 20. , Are removed from the inter-shutoff valve space 10B. Then, by starting to supply the hydrogen gas G1 to the fuel cell device 40 following this state, performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41 is prevented.

(Supply continued)
FIG. 4C shows a supply continuation state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is continued during the normal operation in which the fuel cell system 50 is operated. That is, when the fuel cell system 50 is started, the state of the fuel gas supply path 10 changes from the purge state to the continuous supply state.

  In the transition from the purge state to the supply continuation state, the nitrogen gas supply valve 32 and the bleed valve 21 are closed while the downstream cutoff valve 11B is maintained in the open state, and the upstream cutoff valve 11A and the downstream The side opening / closing valve 13 is opened. Then, the supply of the nitrogen gas NG to the fuel gas supply path 10 and the release of the nitrogen gas NG to the atmosphere via the bleed valve 21 are stopped. In this state, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied to the fuel cell device 40 via the upstream cutoff valve 11A, the downstream cutoff valve 11B, and the downstream open / close valve 13, and the fuel cell device 40 At 40, the desired power generation is performed. Then, at the time of transition to the supply continuation state, since the purge processing has been performed in advance, the fuel gas supply path 10 is in a state filled with the hydrogen gas G1 or the nitrogen gas NG without air. . Therefore, performance degradation due to the supply of air to the fuel cell device 40 is suitably prevented.

  In the present embodiment, when the purging process at the start of the supply of the hydrogen gas G1 to the fuel cell device 40 is completed, the nitrogen gas supply valve 32 and the bleed valve 21 are closed, the upstream shutoff valve 11A and the downstream The on-off valve 13 is opened, but the opening and closing timing of each valve can be changed as appropriate. For example, after the downstream on-off valve 13 is opened, the closing of the nitrogen gas supply valve 32 and the bleed valve 21 and the opening of the upstream shut-off valve 11A may be performed.

[Fourth embodiment]
A fourth embodiment of the present invention will be described with reference to FIG.
In addition, about the structure similar to embodiment mentioned above, detailed description may be omitted.
The fuel cell system 50 shown in FIG. 5 includes the fuel cell device 40, the fuel gas supply path 10, the operation control device 60, and the like, similarly to the above-described embodiment. Hydrogen gas G1 is supplied to 41A.
Further, the fuel cell system 50 of the present embodiment employs a DBB (double block and bleed) composed of an upstream shutoff valve 11A, a downstream shutoff valve 11B, and a bleed valve 21, similarly to the above-described embodiment. ing.
Further, the fuel gas supply passage 10 is provided with a downstream opening / closing valve 13 downstream of the downstream shutoff valve 11B.

  A nitrogen gas supply path 31 (an example of an inert gas supply path) connected to the fuel gas supply path 10 and capable of supplying a nitrogen gas NG (an example of an inert gas) is provided in the fuel gas supply path 10. The nitrogen gas supply passage 31 is formed in a downstream space formed downstream of the downstream cutoff valve 11B in the fuel gas supply passage 10, specifically, with the downstream cutoff valve 11B in the fuel gas supply passage 10 and the downstream opening / closing. It is connected to a downstream inter-valve space 10C1 formed between the valve 13 and the valve 13. In other words, the nitrogen gas supply path 31 is configured as a pipe connecting the nitrogen gas cylinder 30 that stores the nitrogen gas NG and the downstream inter-valve space 10C1 in the fuel gas supply path 10.

  The nitrogen gas supply path 31 is provided with a nitrogen gas supply valve 32 (an example of an inert gas supply valve). The operation control device 60 controls the opening and closing operation of the nitrogen gas supply valve 32 to interrupt the supply of the nitrogen gas NG from the nitrogen gas supply path 31 to the downstream inter-valve space 10C1 of the fuel gas supply path 10. Can be.

  Then, the operation control device 60 supplies the hydrogen gas G1 to the fuel cell device 40 by opening the shutoff valves 11A and 11B to generate power in the fuel cell device 40, as shown in FIG. 5C. During normal operation, the downstream side on-off valve 13 is opened, and the bleed valve 21 and the nitrogen gas supply valve 32 are closed. On the other hand, the operation control device 60 closes the shutoff valves 11A and 11B to stop the supply of the hydrogen gas G1 to the fuel cell device 40 as shown in FIG. When the operation for stopping power generation is stopped, the bleed valve 21 is opened, the downstream opening / closing valve 13 is opened, and the nitrogen gas supply valve 32 is closed.

  That is, when the operation is stopped, the upstream cutoff valve 11A and the downstream cutoff valve 11B are closed with the inter-cutoff valve space 10B opened to the atmosphere, and the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped. You. Thus, even if a failure in shut-down occurs in any of the upstream shut-off valve 11A and the downstream shut-off valve 11B, the side of the hydrogen cylinder 1 and the side of the fuel cell device 40 in the fuel gas supply passage 10 are connected. The space between the shutoff valves 10B opened to the atmosphere is isolated. Therefore, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 due to the poor shutoff of the shutoff valves 11A and 11B is reliably prevented. Further, the hydrogen gas G1 that has flowed into the inter-shut valve space 10B when the operation is stopped is released to the atmosphere via the bleed valve 21 which is in an open state, so that safety is maintained.

  Furthermore, in the fuel cell system 50 according to the present embodiment, at the time of start-up in which the operation shifts from the operation stop state to the normal operation, performance degradation due to the supply of air to the fuel cell device 40 is prevented. To this end, a purge gas PG substantially containing no air (oxygen) is supplied to the inter-shut-valve space 10B before the supply of the hydrogen gas G1 to the fuel cell device 40 is started. A purge process for purging the space 10B is executed by the operation control device 60. That is, if such a purge process is performed before the supply of the hydrogen gas G1 to the fuel cell device 40 is started, the air that has entered the inter-valve space 10B is appropriately removed from the fuel gas supply passage 10. Then, the supply of the hydrogen gas G1 to the fuel cell device 40 is started. This prevents performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41.

The detailed configuration of the purging process in the present embodiment will be described below together with the details of the state change in the fuel gas supply path 10 at the time of starting the operation of the fuel cell system 50 of the present embodiment.
In the fuel cell system 50 according to the present embodiment, at startup, the state of the fuel gas supply path 10 is changed to a supply stopped state (see FIG. 5A), a purge state by valve control performed by the operation control device 60. (See FIG. 5B) and the supply continuation state (see FIG. 5C). Hereinafter, each state will be described in detail.

(Supply stopped)
FIG. 5A illustrates a supply stopped state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is stopped when the operation of the fuel cell system 50 is stopped.
In this supply stop state, the upstream shutoff valve 11A and the downstream shutoff valve 11B are closed, and the bleed valve 21 is opened. Further, in this supply stopped state, the downstream opening / closing valve 13 is opened and the nitrogen gas supply valve 32 is closed.

Then, with respect to the upstream space 10A formed on the fuel gas supply path 10 upstream of the upstream cutoff valve 11A and leading to the hydrogen cylinder 1, the hydrogen gas flowing in the supply continuation state before the supply was stopped is stopped. G1 is satisfied. Further, the downstream spaces 10C1 and 10C2 formed downstream of the downstream shutoff valve 11B in the fuel gas supply passage 10 and leading to the fuel cell device 40 also flow in the supply continuation state before the supply is stopped. The hydrogen gas G1 is filled. On the other hand, the space 10B between the shutoff valves formed between the upstream shutoff valve 11A and the downstream shutoff valve 11B in the fuel gas supply passage 10 is opened to the atmosphere through the bleed valve 21 in the open state. As a result, air entering from the atmosphere is present.
By stopping the supply of the hydrogen gas G1 to the fuel cell device 40 in this manner, as described above, the leakage of the hydrogen gas G1 from the hydrogen cylinder 1 to the fuel cell device 40 is reliably prevented, and the safety is improved. Nature is maintained.

(Purge state)
The operation control device 60 executes a purge process before starting supply of the hydrogen gas G1 to the fuel cell device 40. FIG. 5B shows a purge state, which is a state of the fuel gas supply passage 10 when the purge process is performed. That is, when the fuel cell system 50 is activated, the purge process is executed, so that the state of the fuel gas supply path 10 is changed from the supply stop state to the purge state.

  In transition from the supply stop state to the purge state, the downstream side on-off valve 13 is closed while the bleed valve 21 is maintained in the open state, and the upstream side shutoff valve 11A, the downstream side shutoff valve 11B, and The nitrogen gas supply valve 32 is opened. Then, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied as the purge gas PG to the inter-shut-valve space 10B via the opened upstream-side shut-off valve 11A. Further, the nitrogen gas NG supplied from the nitrogen gas cylinder 30 is supplied as a purge gas PG to the downstream side inter-valve space 10C1 via the opened nitrogen gas supply valve 32, and the nitrogen gas NG is supplied to the downstream opened valve. The purge gas PG is supplied to the inter-shutoff valve space 10B via the side shutoff valve 11B. At the same time, the hydrogen gas G1 and the nitrogen gas NG supplied to the inter-shut valve space 10B are discharged to the outside through the branch passage 20 via the bleed valve 21 maintained in the open state. Then, in this manner, the inter-shutoff valve space 10B is purged by the hydrogen gas G1 and the nitrogen gas NG. That is, in the present embodiment, the hydrogen gas G1 and the nitrogen gas NG are used as the purge gas PG supplied to the inter-shut valve space 10B, and the inter-shut valve space 10B and the like are purged by the hydrogen gas G1 and the nitrogen gas NG.

  When such a purging process is performed, air that has entered the inter-valve interspace 10B from the atmosphere through the bleed valve 21 in the supply stopped state is released to the atmosphere through the bleed valve 21 of the branch passage 20. , Are removed from the inter-shutoff valve space 10B. Then, by starting to supply the hydrogen gas G1 to the fuel cell device 40 following this state, performance degradation due to the supply of air to the anode 41A of the fuel cell stack 41 is prevented.

  In the present embodiment, in the purging process, the upstream side shutoff valve 11A, the downstream side shutoff valve 11B, and the nitrogen gas supply valve 32 are simultaneously opened, and the hydrogen gas G1 as the purge gas PG to the inter-cutoff valve space 10B is opened. And the supply of nitrogen gas NG is performed simultaneously. However, the opening timing of the upstream cutoff valve 11A and the opening timing of the downstream cutoff valve 11B and the nitrogen gas supply valve 32 may be set to different timings. For example, the hydrogen gas G1 is supplied to the inter-shut valve space 10B as the purge gas PG by setting the opening timing of the upstream shut-off valve 11A earlier than the opening timing of the downstream shut-off valve 11B and the nitrogen gas supply valve 32. Later, the nitrogen gas NG can be supplied to the inter-shut valve space 10B as the purge gas PG. Conversely, by setting the opening timing of the downstream side shutoff valve 11B and the nitrogen gas supply valve 32 earlier than the opening timing of the upstream side shutoff valve 11A, the nitrogen gas NG is supplied as the purge gas PG to the inter-shut-valve space 10B. After that, the hydrogen gas G1 can be supplied as the purge gas PG to the inter-shut valve space 10B. Further, regarding the supply of the hydrogen gas G1 as the purge gas PG to the inter-shut valve space 10B and the supply of the nitrogen gas NG as the purge gas PG to the inter-shut valve space 10B, one is terminated and then the other is started. The opening / closing timing of the upstream cutoff valve 11A, the downstream cutoff valve 11B, and the nitrogen gas supply valve 32 may be set.

(Supply continued)
FIG. 5C shows a supply continuation state in which the supply of the hydrogen gas G1 to the fuel cell device 40 is continued during the normal operation in which the fuel cell system 50 is operated. That is, when the fuel cell system 50 is started, the state of the fuel gas supply path 10 changes from the purge state to the continuous supply state.

  When transitioning from the purge state to the supply continuation state, the nitrogen gas supply valve 32 and the bleed valve 21 are closed while the upstream shut-off valve 11A and the downstream shut-off valve 11B are kept open, and The side opening / closing valve 13 is opened. Then, the supply of the nitrogen gas NG to the fuel gas supply passage 10 and the release of the hydrogen gas G1 and the nitrogen gas NG to the atmosphere via the bleed valve 21 are stopped. In this state, the hydrogen gas G1 supplied from the hydrogen cylinder 1 is supplied to the fuel cell device 40 via the upstream cutoff valve 11A, the downstream cutoff valve 11B, and the downstream open / close valve 13, and the fuel cell device 40 At 40, the desired power generation is performed. Then, at the time of transition to the supply continuation state, since the purge processing has been performed in advance, the fuel gas supply path 10 is in a state filled with the hydrogen gas G1 or the nitrogen gas NG without air. . Therefore, performance degradation due to the supply of air to the fuel cell device 40 is suitably prevented.

  In the present embodiment, when the purge process at the start of the supply of the hydrogen gas G1 to the fuel cell device 40 is completed, the downstream side on-off valve 13 is opened simultaneously with the closing of the nitrogen gas supply valve 32 and the bleed valve 21. However, the opening / closing timing of each valve can be appropriately changed. For example, after the downstream on-off valve 13 is opened, the nitrogen gas supply valve 32 and the bleed valve 21 may be closed.

[Another embodiment]
Another embodiment of the present invention will be described. The configuration of each embodiment described below is not limited to being applied independently, and may be applied in combination with the configuration of another embodiment.

(1) In the above embodiment, the fuel cell device 40 is configured to include the fuel cell stack 41 in which the hydrogen gas G1 is supplied from the fuel gas supply path 10 to the anode 41A. However, as shown in FIG. 6, a fuel cell device 40 is provided with a reformer 42 that reforms a hydrocarbon gas G2 such as methane gas or propane gas to generate a hydrogen-containing gas including a hydrogen gas G1. And a fuel cell stack 41 that generates electric power by the electrochemical reaction of the hydrogen gas G1. In this case, the hydrocarbon gas G2 flows through the fuel gas supply path 10, and the hydrocarbon gas G2 is supplied as a fuel gas from the fuel gas supply path 10 to the reformer 42, and The reformer of the purifier 42 becomes a hydrogen-containing gas including the hydrogen gas G1. Then, before the supply of the hydrocarbon gas G2 to the fuel cell device 40 is started, a purge process can be performed in the fuel gas supply passage 10. In this case, the hydrocarbon gas G2 can be used as the purge gas PG in the purge process.

(2) In the above embodiment, the example in which the fuel cell system 50 is mounted as a power source of the fuel cell ship 100 has been described. However, the present invention is not limited to such a configuration, and other transportation machines or energy may be used. The present invention can also be applied to a fuel cell system mounted on a device.

1 hydrogen cylinder (fuel gas storage section)
10 Fuel gas supply path 10B Shut-off valve space 10C Downstream space 10C1 Downstream valve space (downstream space)
11A Upstream side shutoff valve 11B Downstream side shutoff valve 13 Downstream side on-off valve 21 Bleed valve 23 Downstream side relief valve 25 Flow rate regulating valve (flow rate regulating means)
31 Nitrogen gas supply path (inert gas supply path)
32 Nitrogen gas supply valve (inert gas supply valve)
40 fuel cell device 41 fuel cell stack 50 fuel cell system 55 electric motor (electric load on board)
60 Operation control device (valve control means)
100 Fuel cell ship G1 Hydrogen gas (fuel gas)
G2 Hydrocarbon gas (fuel gas)
NG Nitrogen gas (inert gas)
PG purge gas

Claims (12)

A fuel cell device having a fuel cell stack that generates power by an electrochemical reaction of fuel gas,
A fuel gas supply path for supplying fuel gas to the fuel cell device;
A shutoff valve provided in the fuel gas supply path and capable of shutting off the supply path;
The operation of the shut-off valve in a form in which the shut-off valve is closed to stop supplying fuel gas to the fuel cell device, and the shut-off valve is opened to start supplying fuel gas to the fuel cell device. And a valve control means for controlling the fuel cell system,
An upstream shutoff valve and a downstream shutoff valve that are provided in series with the fuel gas supply passage and that can shut off the supply passage are provided as the shutoff valve,
A bleed valve connected to an inter-shut-valve space formed between the upstream-side shut-off valve and the downstream-side shut-off valve in the fuel gas supply path to open the space to the outside;
The valve control means closes the bleed valve when fuel gas is supplied to the fuel cell device, and opens the bleed valve when supply of fuel gas to the fuel cell device is stopped. Controlling the operation and supplying a purge gas, which is at least one of a fuel gas and an inert gas, to the space between the shut-off valves before starting the supply of the fuel gas to the fuel cell device to purge the space between the shut-off valves. Fuel cell system that performs a purge process.   2. The fuel cell system according to claim 1, wherein the valve control unit starts supplying fuel gas to the fuel cell device after performing the purge process for a predetermined set purge time. 3.   3. The valve control unit according to claim 1, wherein, in the purging process, the bleed valve is maintained in an open state, and the purge gas supplied to the inter-shutoff valve space is discharged to the outside via the bleed valve. 3. The fuel cell system according to item 1.   4. The fuel cell system according to claim 3, wherein the valve control unit closes the bleed valve after opening the downstream shutoff valve at the time of starting supply of fuel gas to the fuel cell device. 5.   5. The fuel supply system according to claim 1, wherein the valve control unit opens the upstream shutoff valve in the purge process and supplies fuel gas as the purge gas to the space between the shutoff valves via the upstream shutoff valve. The fuel cell system according to claim 1. The fuel gas supply path has a flow rate adjusting means capable of adjusting the flow rate of the fuel gas,
The valve control means controls the flow rate adjusting means to change the flow rate of the fuel gas in the fuel gas supply path at the time of the purging process to the fuel gas flow rate in the fuel gas supply path during the normal operation of the fuel cell device. The fuel cell system according to claim 5, wherein the flow rate is set to be smaller than the gas flow rate. A downstream open / close valve provided downstream of the downstream shutoff valve in the fuel gas supply path;
A downstream relief valve that is connected to a downstream inter-valve space formed between the downstream shut-off valve and the downstream on-off valve in the fuel gas supply path and that can open the space to the outside,
In the purging process, the valve control unit closes the downstream open / close valve and opens the downstream shutoff valve and the downstream relief valve, thereby allowing the fuel gas supplied to the space between the shutoff valves to be opened. 7. The fuel supply system according to claim 5, wherein the fuel gas supplied to the downstream inter-valve space is discharged to the outside through the downstream relief valve while being supplied to the downstream inter-valve space via the downstream shut-off valve. The fuel cell system as described.   8. The fuel cell system according to claim 7, wherein the valve control means closes the downstream relief valve after opening the downstream on-off valve at the start of supply of the fuel gas to the fuel cell device. An inert gas supply path connected to the fuel gas supply path and capable of supplying an inert gas to the fuel gas supply path;
An inert gas supply valve provided in the inert gas supply path,
The said valve control means opens the said inert gas supply valve in the said purge process, and supplies an inert gas as said purge gas from the said inert gas supply path to the said inter-shut valve space. The fuel cell system according to claim 1. The inert gas supply path is connected to a downstream space formed on the fuel gas supply path on the downstream side of the downstream cutoff valve,
In the purge process, the valve control unit opens the inert gas supply valve and the downstream shutoff valve to inactivate the inert gas supply passage through the downstream space to the space between the shutoff valves. The fuel cell system according to claim 9, which supplies a gas.   11. The fuel according to claim 10, wherein the valve control unit opens the upstream shutoff valve in the purging process and supplies fuel gas as the purge gas to the space between the shutoff valves via the upstream shutoff valve. 12. Battery system. A fuel cell system according to any one of claims 1 to 11,
A fuel gas storage unit for storing fuel gas supplied to the fuel cell system,
A fuel cell ship for supplying electric power generated by the fuel cell system to an electric load on the ship.

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