WO2013137428A1

WO2013137428A1 - Fuel cell system

Info

Publication number: WO2013137428A1
Application number: PCT/JP2013/057384
Authority: WO
Inventors: 晋前嶋; 市川　靖; 池添　圭吾
Original assignee: 日産自動車株式会社
Priority date: 2012-03-15
Filing date: 2013-03-15
Publication date: 2013-09-19
Also published as: JP2015109137A

Abstract

This fuel cell system is provided with: a fuel cell which supplies a fuel gas to an anode, supplies an oxidant gas to a cathode and generates power corresponding to a load; a pressure regulating valve disposed in the supply passage for supplying fuel gas to said fuel cell; and a purge valve provided in the discharge channel for discharging the anode off-gas containing impurities from the fuel cell. This fuel cell system is provided with a pulse operation control unit which controls the pressure regulating valve so as to pulse the fuel gas pressure of the fuel cell stack and such that the fuel gas pressure assumes a prescribed pressure increase speed. Compared with when the moisture state of the power generation region in the fuel cell is low, the pulse operation control unit increases the aforementioned prescribed pressure increase speed when said moisture state is high.

Description

Fuel cell system

This invention relates to a fuel cell system.

JP2010-123501A discloses a fuel cell system in which the pressure of the anode gas pulsates by repeatedly supplying / stopping the high-pressure anode gas. In JP2010-123501A, the first pressure fluctuation pattern in which the pressure fluctuation is performed with the first pressure width ΔP1 and the second pressure fluctuation pattern in which the pressure fluctuation is performed with the second pressure width ΔP2 are periodically changed. Is done.

In JP2010-123501A, the width of pulsation is increased due to drainage, but the present inventors have found that the pressure increase rate of pulsation affects drainage.

Therefore, an object of the present invention is to provide a fuel cell system capable of draining liquid water generated in the power generation amount region of the anode of the fuel cell by a method different from JP2010-123501A.

One aspect of a fuel cell system according to the present invention is to supply a fuel gas to an anode and an oxidant gas to a cathode to generate power according to a load, and to supply the fuel gas to the fuel cell. The fuel cell system is provided with a pressure regulating valve provided in the supply passage and a purge valve provided in the discharge passage for discharging the anode off gas containing impurities from the fuel cell. The fuel cell stack includes a pulsation operation control unit that pulsates the fuel gas pressure of the fuel cell stack and controls the pressure adjustment valve so as to achieve a predetermined pressure increase speed, and the pulsation operation control unit includes a power generation amount of the fuel cell. The predetermined pressure increase rate is increased when the wet state is high as compared to when the wet state is low.

Embodiments of the present invention and advantages of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an outline of a first embodiment of a fuel cell system according to the present invention. FIG. 2A is an external perspective view illustrating a fuel cell stack. FIG. 2B is an exploded view showing the structure of the power generation cell of the fuel cell stack. FIG. 3A is a schematic diagram for explaining the reaction of the electrolyte membrane in the fuel cell stack. FIG. 3B is a schematic diagram for explaining the reaction of the electrolyte membrane in the fuel cell stack. FIG. 4 is a control flowchart executed by the controller of the first embodiment of the fuel cell system. FIG. 5 is a correlation diagram between the wetness of the fuel cell stack and the pressure increase rate. FIG. 6 is a correlation diagram between the anode gas supply flow rate and the pressure increase rate. FIG. 7 is a timing chart for explaining the operation when the control flowchart of the first embodiment is executed. FIG. 8A is a timing chart when changing the upper limit pressure or the lower limit pressure during the drainage operation. FIG. 8B is a timing chart when changing the upper limit pressure or the lower limit pressure during the drainage operation. FIG. 9 is a diagram for explaining the operation of the purge valve of the second embodiment of the fuel cell system according to the present invention. FIG. 10 is a diagram for explaining the variation of the fuel gas pressure in the third embodiment of the fuel cell system according to the present invention. FIG. 11 is a diagram for explaining the fluctuation of the fuel gas pressure in the fourth embodiment of the fuel cell system according to the present invention. FIG. 12 is a correlation diagram between the wetness of the fuel cell stack and the pressure increase rate. FIG. 13 is a diagram for explaining the operation of the purge valve.

(First embodiment)
FIG. 1 is a diagram showing an outline of a first embodiment of a fuel cell system according to the present invention.

The fuel cell system includes a fuel cell stack 100, a hydrogen tank 200, a pressure adjustment valve 300, a buffer tank 400, a purge valve 500, and a controller 600.

The fuel cell stack 100 is supplied with reaction gas (anode gas H ₂ , cathode gas O ₂ ) to generate power. Details will be described later.

The hydrogen tank 200 is a high-pressure gas tank that stores the anode gas H ₂ in a high-pressure state. The hydrogen tank 200 is provided in the uppermost stream of the anode line.

The pressure adjustment valve 300 is provided downstream of the hydrogen tank 200. The pressure adjustment valve 300 adjusts the pressure of the anode gas H ₂ that is newly supplied from the hydrogen tank 200 to the anode line. The pressure of the anode gas H ₂ is adjusted by the opening degree of the pressure adjustment valve 300.

The buffer tank 400 is provided downstream of the fuel cell stack 100. The buffer tank 400 stores the anode gas H ₂ discharged from the fuel cell stack 100.

The purge valve 500 is provided downstream of the buffer tank 400. When the purge valve 500 is opened, the anode gas H ₂ is purged from the buffer tank 400.

The controller 600 controls the operation of the pressure regulating valve 300 and the purge valve 500 based on signals from the pressure sensor 71 provided in the anode line and the current / voltage sensor 72 provided in the fuel cell stack 100. Specific control contents will be described later.

FIG. 2A is an external perspective view illustrating a fuel cell stack. FIG. 2B is an exploded view showing the structure of the power generation cell of the fuel cell stack.

As shown in FIG. 2A, the fuel cell stack 100 includes a plurality of stacked power generation cells 10, a current collecting plate 20, an insulating plate 30, an end plate 40, and four tension rods 50.

The power generation cell 10 is a unit power generation cell of a fuel cell. Each power generation cell 10 generates an electromotive voltage of about 1 volt (V). Details of the configuration of each power generation cell 10 will be described later.

The current collecting plate 20 is disposed outside each of the stacked power generation cells 10. The current collecting plate 20 is formed of a gas impermeable conductive member, for example, dense carbon. The current collecting plate 20 includes a positive electrode terminal 211 and a negative electrode terminal 212. The fuel cell stack 100 takes out and outputs electrons e ⁻ generated in each power generation cell 10 by the positive electrode terminal 211 and the negative electrode terminal 212.

The insulating plates 30 are respectively arranged outside the current collecting plate 20. The insulating plate 30 is formed of an insulating member such as rubber.

The end plate 40 is disposed outside the insulating plate 30. The end plate 40 is made of a rigid metal material such as steel.

One end plate 40 (the left front end plate 40 in FIG. 2A) has an anode supply port 41a, an anode discharge port 41b, a cathode supply port 42a, a cathode discharge port 42b, and a cooling water supply port 43a. A cooling water discharge port 43b is provided. In the present embodiment, the anode supply port 41a, the cooling water supply port 43a, and the cathode discharge port 42b are provided on the right side in the drawing. Further, the cathode supply port 42a, the cooling water discharge port 43b and the anode discharge port 41b are provided on the left side in the drawing.

The tension rods 50 are arranged near the four corners of the end plate 40, respectively. The fuel cell stack 100 has a hole (not shown) penetrating therethrough. The tension rod 50 is inserted through the through hole. The tension rod 50 is formed of a rigid metal material such as steel. The tension rod 50 is insulated on the surface in order to prevent an electrical short circuit between the power generation cells 10. A nut (not shown because it is in the back) is screwed into the tension rod 50. The tension rod 50 and the nut tighten the fuel cell stack 100 in the stacking direction.

As a method of supplying hydrogen as the anode gas to the anode supply port 41a, for example, a method of directly supplying hydrogen gas from a hydrogen storage device or a hydrogen-containing gas reformed by reforming a fuel containing hydrogen is supplied. There are methods. Examples of the hydrogen storage device include a high-pressure gas tank, a liquefied hydrogen tank, and a hydrogen storage alloy tank. Examples of the fuel containing hydrogen include natural gas, methanol, and gasoline. In FIG. 1, a high pressure gas tank is used. Air is generally used as the cathode gas supplied to the cathode supply port 42a.

As shown in FIG. 2B, in the power generation cell 10, an anode separator (anode bipolar plate) 12a and a cathode separator (cathode bipolar plate) 12b are disposed on both surfaces of a membrane electrode assembly (MEA) 11. Is the structure.

MEA 11 has electrode catalyst layers 112 formed on both surfaces of an electrolyte membrane 111 made of an ion exchange membrane. A gas diffusion layer (gas diffusion layer: GDL) 113 is formed on the electrode catalyst layer 112.

The electrode catalyst layer 112 is formed of carbon black particles carrying platinum, for example.

The GDL 113 is formed of a member having sufficient gas diffusibility and conductivity, for example, carbon fiber.

The anode gas supplied from the anode supply port 41a flows through this GDL 113a, reacts with the anode electrode catalyst layer 112 (112a), and is discharged from the anode discharge port 41b.

The cathode gas supplied from the cathode supply port 42a flows through this GDL 113b, reacts with the cathode electrode catalyst layer 112 (112b), and is discharged from the cathode discharge port 42b.

The anode separator 12a is stacked on one side of the MEA 11 (back side in FIG. 2B) via the GDL 113a and the seal 14a. The cathode separator 12b is overlaid on one side (the surface in FIG. 2B) of the MEA 11 via the GDL 113b and the seal 14b. The seal 14 (14a, 14b) is a rubber-like elastic material such as silicone rubber, ethylene-propylene rubber (EPDM), or fluorine rubber. The anode separator 12a and the cathode separator 12b are formed by press-molding a metal separator base such as stainless steel so that a reaction gas channel is formed on one surface and alternately arranged with the reaction gas channel on the opposite surface. A cooling water flow path is formed. As shown in FIG. 2B, the anode separator 12a and the cathode separator 12b are overlapped to form a cooling water flow path.

The MEA 11, the anode separator 12a, and the cathode separator 12b are formed with

holes

41a, 41b, 42a, 42b, 43a, 43b, respectively, which are stacked to form an anode supply port (anode supply manifold) 41a, an anode discharge port. (Anode discharge manifold) 41b, cathode supply port (cathode supply manifold) 42a, cathode discharge port (cathode discharge manifold) 42b, cooling water supply port (cooling water supply manifold) 43a and cooling water discharge port (cooling water discharge manifold) 43b Is formed.

3A and 3B are schematic diagrams for explaining the reaction of the electrolyte membrane in the fuel cell stack.

As described above, the fuel cell stack 100 is supplied with the reaction gas (cathode gas O ₂ , anode gas H ₂ ) to generate power. The fuel cell stack 100 is configured by stacking hundreds of membrane electrode assemblies (MEA) in which a cathode electrode catalyst layer and an anode electrode catalyst layer are formed on both surfaces of an electrolyte membrane. One of them is shown in FIG. 3A. Here, the cathode gas is supplied to the MEA (cathode in) and discharged from the diagonal side (cathode out), while the anode gas is supplied (anode in) and discharged from the diagonal side (anode out). An example is shown.

In each membrane electrode assembly (MEA), the following reaction proceeds in the cathode electrode catalyst layer and the anode electrode catalyst layer according to the load to generate power.

As shown in FIG. 3B, as the reaction gas (cathode gas O ₂ ) flows through the cathode flow path, the reaction of the above equation (1-1) proceeds and water vapor is generated. Then, the relative humidity increases on the downstream side of the cathode channel. As a result, the relative humidity difference between the cathode side and the anode side increases. With this relative humidity difference as the driving force, water is back-diffused and the anode upstream side is humidified. This moisture further evaporates from the MEA to the anode channel, and humidifies the reaction gas (anode gas H ₂ ) flowing through the anode channel. Then, it is transported downstream of the anode and humidifies the MEA downstream of the anode.

In order to generate power efficiently by the above reaction, the electrolyte membrane needs to be in an appropriate wet state. If there is too much water in the electrolyte membrane, excess water overflows into the reaction gas flow path and the gas flow is hindered. In such a case, the above reaction is not promoted. Therefore, power is efficiently generated when the electrolyte membrane is in a moderately wet state.

Therefore, the inventors came up with the following control.

FIG. 4 is a control flowchart executed by the controller of the first embodiment of the fuel cell system. The controller repeatedly executes this flowchart every minute time (for example, 10 milliseconds).

In step S1, the controller determines whether or not the drainage operation is in progress. The drainage operation is executed in step S3 described later. If the determination result is negative, the controller proceeds to step S2, and if the determination result is positive, the controller proceeds to step S4.

In step S2, the controller determines whether or not drainage operation is necessary. Specifically, the voltage of the power generation cell is detected, and if the voltage is smaller than the threshold value, it may be determined that the drainage operation is necessary. For example, if the wetness of the electrolyte membrane is larger than the reference value, it may be determined that the drainage operation is necessary. The wetness of the electrolyte membrane varies depending on the impedance (internal resistance) of the electrolyte membrane. That is, the lower the wetness of the electrolyte membrane (the less dry the electrolyte membrane is, the more dry it is), the greater the impedance. The greater the wetness of the electrolyte membrane (the more moisture in the electrolyte membrane, the more wet it is), the lower the impedance. Therefore, using this characteristic, for example, the generated current of the fuel cell stack is changed with a sine wave of 1 kHz, for example, and the change in voltage is observed. Then, the impedance is obtained by dividing the AC voltage amplitude of 1 kHz by the AC current amplitude. Based on this impedance, the wetness of the electrolyte membrane can be obtained. If the determination result is affirmative, the controller proceeds to step S3, and if the determination result is negative, the controller proceeds to step S6.

In step S3, the controller sets the drain operation. Specifically, for example, a map as shown in FIG. 5 is prepared in advance through experiments or the like. Then, the wetness of the electrolyte membrane is applied to the map, and the pressure increase rate when the fuel gas pressure is supplied in a pulsating manner is set larger than that during normal operation. Note that the pressure increase rate correlates with the supply flow rate as shown in FIG. Therefore, in order to increase the pressure increase speed, it is only necessary to increase the supply flow rate by increasing the opening of the pressure regulating valve 300.

In step S4, the controller determines whether or not drainage operation is unnecessary. Specifically, for example, if the wetness of the electrolyte membrane is smaller than the reference value, it may be determined that the drainage operation is necessary. The reference value may be the same as or different from the reference value for determining that the drainage operation is necessary. If the determination result is positive, the controller proceeds to step S5, and if the determination result is negative, the controller proceeds to step S6.

In step S5, the controller sets normal operation. Specifically, for example, the wetness of the electrolyte membrane is applied to a map as shown in FIG. 5, and the pressure increase rate when the fuel gas pressure is supplied in a pulsating manner is set smaller than that in the drainage operation.

In step S6, the controller determines whether or not the pressure is currently increasing. If the determination result is affirmative, the controller proceeds to step S7, and if the determination result is negative, the controller proceeds to step S9.

In step S7, the controller determines whether or not the current pressure is smaller than the target upper limit pressure. If the determination result is negative, the controller temporarily exits the process. If the determination result is positive, the controller proceeds to step S8.

In step S8, the controller stops supplying the reaction gas.

In step S9, the controller determines whether or not the current pressure is greater than the target lower limit pressure. If the determination result is negative, the controller temporarily exits the process, and if the determination result is positive, the controller proceeds to step S10.

In step S10, the controller starts supplying the reaction gas.

FIG. 7 is a timing chart for explaining the operation when the control flowchart of the first embodiment is executed.

In addition, in order to make it easy to understand the correspondence with the above flowchart, S is added to the step number of the flowchart.

The above control flowchart is executed and operates as follows.

In FIG. 7, before time t14, the cell voltage is greater than the threshold value, and drainage operation is not required. Therefore, until time t11, the process of steps S1, S2, S6, and S7 is repeated. As a result, the anode pressure rises as shown in FIG.

When the anode pressure reaches the target upper limit pressure at time t11, steps S7 → S8 are processed. As a result, as shown in FIG. 7, the anode pressure starts to decrease.

After time t11, steps S1 → S2 → S6 → S9 are repeated. Even while the supply of the anode gas is stopped, the anode gas is consumed by the power generation reaction, so that the anode pressure continues to decrease as shown in FIG.

When the anode pressure reaches the target lower limit pressure at time t12, steps S9 → S10 are processed. As a result, as shown in FIG. 7, the anode pressure starts to increase.

The same control is repeated until time t14.

At time t14, the cell voltage becomes lower than the threshold value and drainage operation is required. Therefore, steps S1 → S2 → S3 are processed to set the pressure increasing speed for drainage operation. Then, after the next cycle, the processes of steps S 1 → S 4 → S 6 → S 7 are repeated. As a result, the anode pressure rises as shown in FIG.

When the anode pressure reaches the target upper limit pressure at time t15, steps S7 → S8 are processed. As a result, as shown in FIG. 7, the anode pressure starts to decrease.

After time t15, steps S1 → S4 → S6 → S9 are repeated. Even while the supply of the anode gas is stopped, the anode gas is consumed by the power generation reaction, so that the anode pressure continues to decrease as shown in FIG.

When the anode pressure reaches the target lower limit pressure at time t16, steps S9 → S10 are processed. As a result, as shown in FIG. 7, the anode pressure starts to increase.

The same control is repeated until time t17.

At time t17, the cell voltage becomes higher than the threshold value, and drainage operation is not necessary. Therefore, steps S1 → S4 → S5 are processed to set the boosting speed for normal operation. After the next cycle, the processes of steps S1, S2, S6, and S7 are repeated. As a result, the anode pressure rises as shown in FIG.

As described above, in the present embodiment, when it is determined that the drainage operation is necessary because the voltage of the power generation cell is smaller than the threshold value, the pressure increase rate when the fuel gas pressure is supplied in pulsation is the normal operation. Is set larger than As the pressure increase rate increases, the flow rate of the anode gas flowing through the anode supply manifold increases rapidly, and the liquid water remaining in the anode flow path is discharged. This secures the hydrogen partial pressure and stabilizes the power generation performance. Further, it is possible to prevent deterioration caused by the lack of fuel in the cell. Further, when the cell voltage is restored, the boosting speed is restored to the original value. This also secures the hydrogen partial pressure in the cell and stabilizes the power generation performance.

In this embodiment, since it is determined whether or not the drainage operation is necessary based on the cell voltage, it can be accurately determined.

Further, the control of the pressure regulating valve described in the present embodiment may be the following control.

The upper limit pressure and the lower limit pressure set according to the fuel cell supply load (current) are read from the map. Both the upper limit pressure and the lower limit pressure increase as the load increases. At the same time, the differential pressure between the upper limit pressure and the lower limit pressure increases as the load increases.

Such a map increases the anode pressure on the high load side rather than the low load, and increases the pulsation width at the high load as compared with the pulsation width at the low load.

Then, when increasing the pressure, the pulsation control unit performs pressure feedback control by the pressure regulating valve with reference to the value of the pressure sensor provided at the anode inlet of the fuel cell stack with the upper limit pressure as the target value.

When the actual pressure is close to the target pressure by feedback control, the pulsation control unit performs feedback control again with the lower limit pressure as the target pressure.

繰り返す By repeating this control, pulsation operation is performed at the upper and lower limit pressure by the pressure regulating valve.

In particular, the pressure increase speed may be set such that the pressure increase speed increases as the wet state of the power generation amount region (electrolyte membrane) of the fuel cell increases.

Specifically, in the above feedback control, when the target pressure is switched from the lower limit pressure to the upper limit pressure, the target pressure of the pressure increase speed corresponding to the wet state may be set. Further, the gain of feedback control may be set so that the target pressure is switched stepwise from the lower limit pressure to the upper limit pressure while the actual pressure increase rate of the anode pressure becomes a speed corresponding to the wet state.

As shown in FIG. 8A, the lower limit pressure may be lowered as the pressure increase rate is increased. Since the pressure is increased from the place where the lower limit pressure is low, the gas flow rate tends to be high even if the pressure increase rate is the same. Therefore, if it does in this way, the drainage performance of the liquid water which remained in the anode channel will further improve.

Also, as shown in FIG. 8B, the upper limit pressure may be increased as the pressure increase rate is increased. In this way, since the pressure further increases, the gas flow rate tends to increase even if the pressure increase rate is the same. Therefore, even if it does in this way, the discharge performance of the liquid water which remained in the anode flow path improves.

(Second Embodiment)
FIG. 9 is a diagram for explaining the operation of the purge valve of the second embodiment of the fuel cell system according to the present invention.

In the first embodiment, when it is determined that the drainage operation is necessary, the pressure increase speed when the fuel gas pressure is supplied in a pulsating manner is set large.

In contrast, in this embodiment, when it is determined that the drainage operation is necessary, the valve opening time of the purge valve 500 is lengthened in addition to the control of the first embodiment.

As described above, when the opening time of the purge valve 500 is increased, the flow rate of the anode gas is further increased, so that the liquid water remaining in the anode channel is more easily discharged. If the control of the purge valve 500 is also executed in accordance with the control of the first embodiment as described above, the pressure increase speed is not increased as compared with the first embodiment, and may be the same as that in the normal operation. However, even if the pressure increase rate is the same as that in the normal operation, the flow rate of the anode gas is higher than that in the normal operation, so that the discharge performance of the liquid water remaining in the anode channel is improved.

(Third embodiment)
FIG. 10 is a diagram for explaining the variation of the fuel gas pressure in the third embodiment of the fuel cell system according to the present invention.

In the first embodiment, it is determined that the drainage operation is necessary when the voltage of the power generation cell becomes smaller than the threshold value.

On the other hand, in this embodiment, it is determined that the drainage operation is necessary for every predetermined cycle. In FIG. 10, the drainage operation is executed every three cycles.

In this way, since it is not necessary to measure the cell voltage, it can be carried out easily.

(Fourth embodiment)
FIG. 11 is a diagram for explaining the fluctuation of the fuel gas pressure in the fourth embodiment of the fuel cell system according to the present invention.

In the third embodiment, it is determined that the drainage operation is necessary every certain cycle.

In contrast, in the present embodiment, the timing of the drainage operation is determined in a shorter period than the time when the drainage operation is necessary. In FIG. 11, the time when the drainage operation is necessary comes in three cycles. In FIG. 11, the drainage time may be determined by two cycles shorter than the three cycles, or the drainage time may be determined by one cycle (that is, continuous cycle).

Even in this case, since it is not necessary to measure the cell voltage, it can be easily carried out.

The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

For example, in the first embodiment, the pressure increase rate when the fuel gas pressure is supplied in a pulsating manner is set to be binary larger or smaller depending on whether or not the drainage operation is necessary. However, it is not limited to such a method. For example, instead of FIG. 5, a map as shown in FIG. 12 may be used to set the pressure increase rate according to the stack wetness.

In the second embodiment, when it is determined that the drainage operation is necessary, the opening time of the purge valve 500 is increased in addition to the control of the first embodiment. However, it is not limited to such a method. For example, instead of FIG. 9, the valve closing time of the purge valve 500 may be shortened as shown in FIG. Even if it does in this way, the same effect can be acquired.

Further, the above embodiments can be appropriately combined.

This application claims priority based on Japanese Patent Application No. 2012-59261 filed with the Japan Patent Office on March 15, 2012, the entire contents of which are incorporated herein by reference.

Claims

A fuel cell that supplies fuel gas to the anode and oxidant gas to the cathode to generate electric power according to a load; and a pressure regulating valve provided in a supply passage for supplying the fuel gas to the fuel cell; In a fuel cell system comprising a purge valve provided in a discharge channel for discharging anode offgas containing impurities from the fuel cell,
A pulsation operation control unit that pulsates the fuel gas pressure of the fuel cell stack and controls the pressure adjustment valve so as to achieve a predetermined pressure increase speed,
The pulsation operation control unit increases the predetermined pressure increase speed when the wet state is high, as compared to when the wet state of the power generation amount region of the fuel cell is low.
Fuel cell system.
The fuel cell system according to claim 1, wherein
An anode gas pressure detector for detecting the anode gas pressure in the power generation region of the fuel cell;
The pulsation operation control unit sets an upper limit pressure and a lower limit pressure for pulsation, and at the time of pressure increase, switches the target pressure for pulsation from the lower limit pressure to the target pressure to the target pressure and the actual anode gas pressure. Feedback control of the pressure regulating valve based on the value,
The pressure increase speed is gradually set to the upper limit pressure as the target pressure at the time of switching, or is set by the gain of feedback control,
Fuel cell system.
The fuel cell system according to claim 2, wherein
It has an internal resistance detector that detects the resistance of the fuel cell electrolyte membrane,
The pulsation operation control unit increases the predetermined pressure increase rate when the internal resistance is equal to or lower than a predetermined value in order to determine a wet state.
Fuel cell system.
The fuel cell system according to claim 3, wherein
A purge adjusting unit that increases the predetermined pressure increase rate when the internal resistance is less than or equal to a predetermined value and makes the opening of the purge valve larger than the opening set when the internal resistance is less than or equal to a predetermined value; Including,
Fuel cell system.
In the fuel cell system according to any one of claims 1 to 4,
The pulsation operation control unit increases the predetermined boosting speed when the cell voltage is a predetermined value or less.
Fuel cell system.
In the fuel cell system according to any one of claims 1 to 4,
The pulsation operation control unit increases the predetermined pressure increase rate every predetermined cycle.
Fuel cell system.