Fuel cell system and control methods for fuel cell systems

Abstract

A fuel cell system (100) comprises: a high-pressure tank (200) with a resin lining (210) and a reinforcing layer (220); a receiving section configured to receive a value for an internal pressure and an internal temperature of the high-pressure tank (200); a notification section (84); and a control section (80). The control section (80) sets a boundary line in a characteristic map of internal temperature and internal pressure, which divides the map into a first region and a second region, wherein the first region indicates the possibility that a stress induced in the resin lining (210) could damage the resin lining (210), and wherein the second region corresponds to a region with a higher temperature and pressure than the first region.When the internal temperature and internal pressure values ​​reach the limit line, the control section (80) causes the notification section (84) to report that the high-pressure tank (200) needs to be filled with fuel gas.

Description

Background of the invention 1. Field of the invention

[0001] This disclosure relates to a fuel cell system and a control method for a fuel cell system. 2. Description of the related prior art

[0002] A method for detecting a residual amount in a high-pressure hydrogen tank so that a residual amount of hydrogen is estimated from a pressure inside the high-pressure hydrogen tank is well known (for example, Japanese Unexamined Patent Publication No. JP 2011-137545 A).

[0003] Furthermore, the subsequently published DE 10 2016 217 341 A1 discloses a method for determining the restartability of a vehicle, in particular when the vehicle is parked, wherein the vehicle has a pressure vessel system with a pressure vessel for storing a fuel, comprising the following steps: detecting the pressure and the temperature of the fuel in the pressure vessel, determining an end pressure value of the fuel in the pressure vessel, wherein the end pressure value is the expected pressure of the fuel in the pressure vessel after a parking period of the vehicle, comparing the determined end pressure value with a minimum pressure value to determine whether the vehicle is restartable after the parking period, and generating an indication signal if the determined end pressure value is lower than the minimum pressure value.

[0004] Furthermore, DE 10 2011 111 609 A1 discloses a method and system for preventing a gas pressure in a pressure vessel from falling below a permissible minimum pressure. Pressure readings from a pressure sensor downstream of a pressure regulator are monitored by a processor as they change within a constant fluctuation band under normal, regulated pressure conditions. When the pressure regulator reaches a fully open position under low vessel pressure conditions, the processor detects a decrease in the pressure reading to a value below the last fluctuation band and recognizes that the pressure has fallen below the regulated pressure value.The processor can use this information to shut off gas flow from the vessel to prevent the vessel from falling below its minimum allowable pressure, regardless of the actual magnitude of the pressure reading from the sensor - which can vary over a wide range due to tolerances. Summary of the invention

[0005] In a case where a tank with a resin liner and a reinforcing layer formed around the resin liner is used as a high-pressure hydrogen tank, it is known that the resin liner expands or contracts due to changes in the operating environment, such as the temperature of the tank or the internal pressure of the tank. The present inventors have found that if an extremely contracted state of the resin liner and an extremely expanded state of the resin liner are repeated, excessive stress is induced in the resin liner, and the resin liner may be damaged.

[0006] This revelation is attainable in the following aspects. (1) A first aspect of this disclosure provides a fuel cell system. The fuel cell system includes a fuel cell stack, a high-pressure tank, an acquiring section, a notification section, and a control section. The fuel cell stack is configured to generate electric power by consuming a fuel gas. The high-pressure tank includes a resin liner and a reinforcing layer configured to cover an outer surface of the resin liner. The high-pressure tank is filled with the fuel gas. The acquiring section is configured to acquire an internal pressure value of the high-pressure tank and an internal temperature value corresponding to a temperature inside the high-pressure tank. The notification section is configured to notify that the high-pressure tank needs to be filled with the fuel gas.The control section is configured to control an operation of the notification section using the internal temperature value and the internal pressure value. The control section sets a boundary line in a map of the internal temperature and the internal pressure, dividing the map into a first region and a second region. The first region indicates a possibility that stress induced in the resin liner due to contraction of the resin liner will damage the resin liner. The second region has a higher temperature and pressure than the first region. When the internal temperature value and the internal pressure value reach the boundary line, the control section causes the notification section to notify that the high-pressure tank needs to be filled with the fuel gas.In the fuel cell system of this aspect, when the internal temperature and pressure drop and reach the boundary line, the control section causes the notification section to notify that the high-pressure tank needs to be filled with fuel gas. This can reduce the possibility of the resin liner being damaged due to a difference in the contraction amount between the resin liner and the reinforcement layer. Here, "the internal temperature and pressure reach the boundary line" means that, in the internal temperature-pressure map, a point formed by the internal temperature value and the internal pressure value reaches the boundary line. Specifically, the point corresponds to one of the points forming the boundary line or one of the points located on either side of the first range from the boundary line. (2) In the fuel cell system of the above aspect, when the internal pressure value reaches a predetermined threshold, the control section may cause the notification section to notify that the high-pressure tank needs to be filled with the fuel gas, regardless of whether the internal temperature value and the internal pressure value reach the limit line or not. In the fuel cell system of this aspect, when an internal pressure condition is met, the notification is executed regardless of whether the internal temperature and the internal pressure reach the limit line or not. This makes it possible to restrict a situation such that the internal pressure decreases sharply from the predetermined threshold. For this reason, the possibility that the fuel cell stack cannot generate electric power due to a shortage of the fuel gas can be reduced. (3) In the fuel cell system of the above aspect, the resin liner may include a bonded portion provided at a central portion of the resin liner in the longitudinal direction of the resin liner to be bonded to the reinforcing layer. Stress due to contraction of the resin liner may be induced in the resin liner at the bonding portion. With the fuel cell system of this aspect, it is possible to reduce the possibility of the resin liner being damaged by stress due to contraction of the resin liner at the bonding portion. (4) In the fuel cell system of the above aspect, the obtaining section may include any one of the following elements (i) to (iii): (i) a pressure sensor configured to obtain the value of the internal pressure and a temperature sensor configured to obtain the value of the internal temperature; (ii) the pressure sensor configured to obtain the value of the internal pressure and a temperature estimating section configured to estimate the value of the internal temperature using the value of the internal pressure; and (iii) the temperature sensor configured to obtain the value of the internal temperature and a pressure estimating section configured to estimate the value of the internal pressure using the value of the internal temperature.With the fuel cell system of this aspect, it is possible to provide a fuel cell system provided with the obtaining section comprising any one of the above-described elements (i) to (iii). (5) In the fuel cell system of the above aspect, the high-pressure tank may be constructed of a plurality of high-pressure tanks. When the internal temperature and internal pressure of at least one of the high-pressure tanks reach the limit, the control section may cause the notification section to notify that at least one of the high-pressure tanks needs to be filled with the fuel gas. (6) In the fuel cell system of the above aspect, when each of the internal pressure values ​​of the high-pressure tanks reaches the predetermined threshold, the control section may cause the notification section to notify that the at least one of the high-pressure tanks needs to be filled with the fuel gas, regardless of whether the internal temperature value and the internal pressure value reach the boundary line or not. (7) In the fuel cell system of the above aspect, the high-pressure tanks may be connected to the fuel cell stack via a fuel gas supply passage. The fuel gas supply passage may be provided with opening and closing valves. The control section may control the opening and closing valves at the time of power generation of the fuel cell stack so that the high-pressure tanks have the same internal pressure. (8) In the fuel cell system of the above aspect, the high-pressure tanks may be connected to the fuel cell stack via a fuel gas supply passage. The fuel gas supply passage may be provided with opening and closing valves. At a time of power generation of the fuel cell stack, the control section may control the opening and closing valves so that the internal pressure of a second high-pressure tank among the high-pressure tanks does not decrease until the internal pressure of a first high-pressure tank among the high-pressure tanks drops to a predetermined pressure value. When the internal pressure value and the internal temperature value of the second high-pressure tank reach the limit line, the control section causes the notification section to notify that at least the second high-pressure tank needs to be filled with the fuel gas. (9) In the fuel cell system of the above aspect, when the value of the internal pressure of the second high-pressure tank reaches the predetermined threshold, the control section may cause the notification section to notify that at least the second high-pressure tank needs to be filled with the fuel gas, regardless of whether the value of the internal temperature and the value of the internal pressure reach the boundary line or not. (10) A second aspect of this disclosure provides a control method for a fuel cell system. The control method includes: obtaining a value of an internal pressure of a high-pressure tank and a value of an internal temperature corresponding to a temperature inside the high-pressure tank, the high-pressure tank including a resin liner and a reinforcing layer configured to cover an outer surface of the resin liner, the high-pressure tank being filled with a fuel gas to be consumed for power generation by a fuel cell stack;Setting a boundary line in a map of internal temperature and internal pressure, dividing the map into a first region and a second region, the first region indicating a possibility that stress induced in the resin liner due to contraction of the resin liner will damage the resin liner, the second region corresponding to a region with a higher temperature and a higher pressure than the first region; and initiating a notification section to notify that the high-pressure tank needs to be filled with the fuel gas when the internal temperature value and the internal pressure value reach the boundary line;

[0007] This disclosure may be implemented in various aspects different from the fuel cell system described above. For example, this disclosure may be implemented in the form of the control method for the fuel cell system, a mobile body such as a fuel cell vehicle, a ship, or an aircraft having the fuel cell system, or a fixed facility such as a house or a building having the fuel cell system. Short description of the figures

[0008] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like reference numerals designate like elements, and wherein: Fig. 1 is a schematic view of a fuel cell system according to a first embodiment; Fig. 2 is a schematic view of a high-pressure tank according to the first embodiment; Fig. 3 is a diagram illustrating a data map of an internal temperature and an internal pressure of a resin liner in the first embodiment; Fig. 4 is a flowchart illustrating the procedure at the time when notification is executed in the fuel cell system according to the first embodiment; Fig. 5 is a schematic view of a high-pressure tank according to a second embodiment; Fig. 6 is a diagram illustrating a data map of an internal temperature and an internal pressure of a resin liner in the second embodiment; and Fig. 7 is a schematic view for describing a state of a joint part in a case where the internal temperature and internal pressure of the resin liner fall within a range where stress occurs. Detailed Description of Embodiments A. First Embodiment

[0009] Fig. 1 is a schematic view of a fuel cell system 100 according to the first embodiment. The fuel cell system 100 includes a fuel cell stack 20, a fuel gas supply / discharge mechanism 50, an oxidizing gas supply / discharge mechanism 60, a refrigerant circulation mechanism 70, a control section 80, a storage section 82, and a notification section 84. The fuel cell system 100 generates electric power through a reaction between a fuel gas (anode gas) and an oxidizing gas (cathode gas). In the present embodiment, the fuel gas corresponds to hydrogen gas, and the oxidizing gas corresponds to air.

[0010] The refrigerant circulation mechanism 70 is connected to the fuel cell stack 20 and includes a refrigerant circulation passage 71 through which a refrigerant (for example, water) circulates, and a pump 72 configured to discharge the refrigerant. The oxidizing gas supply / discharge mechanism 60 includes an oxidizing gas supply passage 61 through which the oxidizing gas is supplied to the fuel cell stack 20, and an oxidizing gas discharge passage 62 through which the oxidizing gas is discharged to the outside. An air compressor 63 configured to convey the oxidizing gas is located inside the oxidizing gas supply passage 61. The oxidizing gas supply / discharge mechanism 60 supplies air to the fuel cell stack 20 and discharges air from the fuel cell stack 20.In the present embodiment, the fuel cell system 100 is provided in a fuel cell vehicle and is used as a power generator for driving a drive motor.

[0011] The fuel cell stack 20 has a stacked structure in which a plurality of single fuel cells (not shown) are laminated. In the present embodiment, the single fuel cell constituting the fuel cell stack 20 is a solid polymer fuel cell configured to generate electrical power through an electrochemical reaction between oxygen and hydrogen. The fuel cell stack 20 is adjusted to an appropriate temperature by the coolant circulation mechanism 70.

[0012] The fuel gas supply / discharge mechanism 50 includes a fuel gas filling passage 32, a fuel gas supply passage 34, a fuel gas circulation passage 36, and two high-pressure tanks 202, 204. The high-pressure tanks 202, 204 correspond to tanks in which the fuel gas is stored and which are connected to the fuel gas filling passage 32 and the fuel gas supply passage 34 via main stop valves 421, 422 corresponding to opening and closing valves. The high-pressure tanks 202, 204 supply the fuel gases stored therein to the fuel cell stack 20 via the fuel gas supply passage 34. Temperature sensors 93, 94 are provided within the high-pressure tanks 202, 204 as an acquiring section configured to acquire internal temperature values ​​corresponding to temperatures within the high-pressure tanks 202, 204.When a common property or structure of the two high-pressure tanks 202, 204 is described in the following description, these are also referred to as one high-pressure tank 200.

[0013] The fuel gas filling passage 32 corresponds to a passage communicating with the high-pressure tanks 202, 204 and is configured such that a fuel gas filled from a fuel gas filling device, such as a hydrogen station, circulates through the fuel gas filling passage 32. One end of the fuel gas filling passage 32 is provided with a container 30, which serves as a communication port when the fuel gas filling passage 32 is connected to the fuel gas filling device.

[0014] The fuel gas supply passage 34 corresponds to a passage through which the fuel gases filled in the high-pressure tanks 202, 204 are supplied to the fuel cell stack 20. The fuel gas supply passage 34 is provided with opening and closing valves 432, 434, a regulator 44, and an injector 45. Furthermore, the fuel gas circulation passage 36 is connected in the center of the fuel gas supply passage 34.

[0015] The fuel gas supply passage 34 is provided with pressure sensors 91, 92 as the acquisition portion, such that the pressure sensor 91 is disposed between the opening and closing valve 432 and the high-pressure tank 202, and the pressure sensor 92 is disposed between the opening and closing valve 434 and the high-pressure tank 204. At the position where the pressure sensor 91, 92 is located, no pressure-changing component, such as a pressure regulating valve, is disposed between the high-pressure tank 202, 204 and the pressure sensor 91, 92. For this reason, a pressure value acquired by the pressure sensor 91, 92 is approximately equal to an internal pressure value of the high-pressure tank 202, 204.

[0016] The fuel gas circulation passage 36 corresponds to a passage through which unreacted fuel gas passing through the fuel cell stack 20 is collected and resupplied to the fuel cell stack 20. Disposed in the center of the fuel gas circulation passage 36 are a hydrogen pump 46 configured to circulate the fuel gas and a gas / liquid separator 47 configured to separate the fuel gas from liquid water contained in the fuel gas. The liquid water contained in the fuel gas corresponds to generated water generated by an electrochemical reaction in the fuel cell stack 20. The liquid water separated by the gas / liquid separator 47 is discharged to the outside by opening an opening and closing valve 48.

[0017] In the present embodiment, the fuel gases in the two high-pressure tanks 202, 204 are adjusted to be consumed so that the internal pressures of the high-pressure tanks 202, 204 become equal. Here, "the internal pressures are equal" means that the internal pressures of the high-pressure tanks 202, 204 have the same value or that the internal pressures of the high-pressure tanks 202, 204 fall within a predetermined allowable range in which the internal pressures are considered equal. In this case, the respective decrease rates of the fuel gases in the high-pressure tanks 202, 204 are reduced compared to a case where the fuel gas from only one high-pressure tank is consumed. This prevents sudden decreases in the internal temperatures of the high-pressure tanks 202, 204 due to adiabatic expansion of the fuel gases in the high-pressure tanks 202, 204.

[0018] The control section 80 includes a central processing unit (CPU), which controls the operation of the notification section 84 using information acquired by various sensors 91 to 94 and information stored in the storage section 82. Details of the control of the notification section 84 by the control section 80 will be described later.

[0019] The storage section 82 includes a storage medium such as a hard disk. Various programs used when the control is executed by the control section 80 and the information acquired from the various sensors 91 to 94 are stored in the storage section 82.

[0020] In response to an instruction from the control section 80, the notification section 84 notifies a user of the fuel cell system 100 that the high-pressure tank 200 needs to be filled with the fuel gas. In the present embodiment, the user of the fuel cell system 100 corresponds to an occupant of a fuel cell vehicle equipped with the fuel cell system 100. The notification section 84 executes the notification by, for example, issuing an alarm, playing an audio signal, displaying an image, or illuminating a light source.

[0021] Fig. 2 is a schematic view of the high pressure tank 200 according to the first embodiment. Fig. 2 illustrates a cross-sectional structure obtained when the high-pressure tank 200 is cut along a central axis CX of the high-pressure tank 200. The high-pressure tank 200 includes a resin liner 210 and a reinforcing layer 220. A first mouthpiece 222 and a second mouthpiece 224 are attached to opposite ends of the high-pressure tank 200 in its longitudinal direction (a direction along the central axis CX). The first mouthpiece 222 has a through-hole through which the interior of the high-pressure tank 200 communicates with the exterior thereof. The filling of the high-pressure tank 200 with the fuel gas and the supply of the fuel gas from the high-pressure tank 200 to the fuel cell stack 20 are performed through the through-hole of the first mouthpiece 222. The second mouthpiece 224 has no through-hole and is used, for example, for heat exchange between the interior of the high-pressure tank 200 and the exterior thereof.

[0022] The resin liner 210 includes a cylindrical portion 211 having a cylindrical shape and hemispherical dome portions 212, 214 arranged at opposite ends of the cylindrical portion 211. The resin liner 210 corresponds to a hollow container having an interior space 216 corresponding to a space to be filled with gas. The resin liner 210 is used as a tank element assembly of the high-pressure tank 200. Resin with low permeability to the fuel gas (hydrogen gas) is used for the resin liner 210. For example, polyamide 6, ethylene vinyl alcohol, or fully saponified polyvinyl alcohol can be used as the resin for forming the resin liner 210. In the present embodiment, the resin liner 210 is composed of a synthetic resin mainly containing polyamide 6.

[0023] The reinforcement layer 220 corresponds to a fiber-reinforced resin layer obtained by impregnating fibers with thermosetting resin, and the reinforcement layer 220 is formed to cover an outer surface of the resin liner 210. In the present embodiment, a mold release agent (not shown) is applied to an entire interface between the resin liner 210 and the reinforcement layer 220. The fiber-reinforced resin layer includes a carbon fiber-reinforced resin layer comprising carbon fibers and thermosetting resin, and a glass fiber-reinforced resin layer comprising glass fibers and thermosetting resin. For the thermosetting resin, for example, epoxy resin or unsaturated polyester resin can be used. In the present embodiment, epoxy resin is used.

[0024] The resin liner 210 contracts or expands according to changes in the internal temperature and pressure. For example, in a case where the internal temperature is low, the resin liner 210 contracts compared to a case where the internal temperature is high. This is because the resin liner 210 contracts according to a linear expansion coefficient of the resin constituting the resin liner 210 due to a low internal temperature. Also, for example, in a case where the internal pressure is small, the resin liner 210 contracts compared to a case where the internal pressure is high. Furthermore, the viscosity of the resin constituting the resin liner 210 increases with decreasing internal temperature. In view of this, for the same applied internal pressure, an expansion or expansion degree of the resin liner 210 is smaller at a low internal temperature than at a high internal temperature.

[0025] Meanwhile, in a case where the internal temperature or internal pressure changes, a degree of contraction or expansion of the reinforcing layer 220 is smaller than a degree of contraction or expansion of the resin liner 210. This is because a linear expansion coefficient of the resin constituting the reinforcing layer 220 is smaller than the linear expansion coefficient of the resin constituting the resin liner 210. Since the reinforcing layer 220 has a larger or higher elastic modulus than the resin liner 210, the degree of contraction or expansion of the reinforcing layer 220 is smaller than the degree of contraction or expansion of the resin liner 210 in the case where the internal pressure changes.

[0026] As a result, the resin liner 210 contracts greatly in a case where the internal temperature is low and the internal pressure is low. Meanwhile, even in a case where the internal temperature is low and the internal pressure is low, the degree of contraction of the reinforcing layer 220 is smaller than the degree of contraction of the resin liner 210. For this reason, at a low internal temperature and low internal pressure, a gap may be formed between the resin liner 210 and the reinforcing layer 220 due to a difference in the amount of contraction between the resin liner 210 and the reinforcing layer 220. At a boundary between the resin liner 210 and the reinforcing layer 220, the gap is easily formed at a boundary between the dome portion 212, 214 and the reinforcing layer 220.In a region where the gap is formed between the resin liner 210 and the reinforcing layer 220, tensile stress induced by the internal pressure of the resin liner 210 occurs. For example, in a case where the gap is formed at the time of filling the fuel gas into the high-pressure tank 200, large stress may occur in the resin liner 210. Note that the stress induced in the resin liner 210 at the time of filling the fuel gas tends to increase as the gap formed between the resin liner 210 and the reinforcing layer 220 becomes larger.

[0027] The gap between the resin liner 210 and the reinforcement layer 220 is easily formed as a length L of the high-pressure tank 200 in the longitudinal direction is longer. More specifically, as the length L of the high-pressure tank 200 in the longitudinal direction is longer, the internal temperature at which the gap between the resin liner 210 and the reinforcement layer 220 starts to form becomes higher. Furthermore, as the length L of the high-pressure tank 200 in the longitudinal direction is longer, the internal pressure at which the gap between the resin liner 210 and the reinforcement layer 220 starts to form becomes higher. Furthermore, as a diameter R of the cylindrical portion 211 on a plane perpendicular to the central axis CX is smaller, the internal pressure at which the gap between the resin liner 210 and the reinforcement layer 220 starts to form becomes higher.

[0028] Fig. 3 is a diagram illustrating a data map of the internal temperature and internal pressure of the resin liner 210 in the first embodiment. In Fig. 3, a first region a1 and a second region a2 are shown. The first region a1 corresponds to a region indicating that a stress induced in the resin liner 210 by the contraction of the resin liner 210 could damage the resin liner 210. In Fig. 3, the first region a1 corresponds to a region represented by line hatching and cross-hatching. The second region a2 corresponds to a region with a higher temperature and a higher pressure than the first region a1. The first region a1 and the second region a2 are separated by a boundary line Th.

[0029] A region indicated by cross-hatching in the first region a1 corresponds to a stress occurrence region a11, or a region a11 where stress occurs. The stress occurrence region a11 corresponds to a region where stress induced in the resin liner 210 due to a difference in the contraction amount between the resin liner 210 and the reinforcing layer 220 becomes stress that damages the resin liner 210, the difference being caused by changes in the internal temperature and internal pressure. In the present embodiment, the stress occurrence region a11 is determined based on a result of simulating a relationship between the gap formed between the resin liner 210 and the reinforcing layer 220 and the stress induced in the resin liner 210 at the time of fuel gas filling.Furthermore, the boundary line Th is defined by a combination of a predetermined reference internal temperature and a predetermined reference internal pressure before the stress induced in the resin liner 210 becomes a stress that damages the resin liner 210. This combination is determined by adding a safety ratio to the stress occurrence range a11. In the following description, the combination of the reference internal temperature and the reference internal pressure that defines the boundary line Th is also referred to as a reference condition. Note that a range indicated by line hatching in the first range a1 corresponds to a range where the safety ratio is considered.

[0030] Here, the size of the gap formed between the resin liner 210 and the reinforcement layer 220 is calculated according to the contraction or expansion of the resin liner 210 due to a change in the internal temperature and the contraction or expansion of the resin liner 210 due to a change in the internal pressure. The contraction or expansion of the resin liner 210 due to the change in the internal temperature is calculated using the length L of the resin liner 210 in the longitudinal direction, the diameter R of the resin liner 210, the linear expansion coefficient, and the internal temperature.The contraction or expansion of the resin liner 210 due to the change in internal pressure is calculated using the length L of the resin liner 210 in the longitudinal direction, the diameter R of the resin liner 210, a wall thickness of the resin liner 210, a Young's modulus, a Poisson's ratio, and a tensile stress induced by the internal pressure. Note that the Young's modulus changes according to the temperature (internal temperature) of the resin liner 210. For example, when the temperature decreases, the Young's modulus increases. Further, when the temperature increases, for example, the Young's modulus decreases. Furthermore, the simulation also considers an amount of change in the gap size when a positional relationship between the resin liner 210 and the reinforcing layer 220 changes due to the expansion or contraction of the resin liner 210.In the present embodiment, the data map including the voltage occurrence range a11 and the boundary line Th is stored in the storage section 82 (. Fig. 1). It should be noted that a predetermined threshold P1 (described later) in Fig. 3, however, in the present embodiment, the threshold P1 is stored in the storage section 82 separately from the data map. The threshold P1 corresponds to an internal pressure threshold.

[0031] Fig. 4 is a flowchart illustrating notification control executed by the fuel cell system 100 according to the first embodiment. The notification control is started when a power supply of the fuel cell system 100 is turned on. Turning on the power supply of the fuel cell system 100 corresponds, for example, to a case where a start switch is pressed by the occupant of the fuel cell vehicle equipped with the fuel cell system 100, so that power generation by the fuel cell stack 20 is started. Here, the start switch corresponds to a switch configured to switch the fuel cell system 100 between startup and stop.

[0032] At the start of the notification control, the control section 80 determines whether an internal pressure condition that a respective value of the internal pressures of the high-pressure tanks 202, 204 exceeds the predetermined threshold P1 ( Fig. 3) is met or not (step S101). In the present embodiment, the internal pressure condition corresponds to a value at which a travel distance based on a total residual fuel gas amount of the two high-pressure tanks 202, 204 is not more than or greater than a predetermined distance (for example, 3 km), and an example of the value is 0.8 MPa. The pressure values ​​measured by the pressure sensors 91, 92 ( Fig. 1) measured pressure values ​​are used as the internal pressures of the high-pressure tanks 202, 204. If, at step S101, the internal pressures of the two high-pressure tanks 202, 204 are both less than the threshold P1, it is determined that the internal pressure condition is met (step S101: Yes).

[0033] If the internal pressure condition is not satisfied (step S101: No), the control section 80 then determines whether the reference condition that values ​​of the internal pressures and values ​​of the internal temperatures of the high-pressure tanks 202, 204 reach the boundary line Th ( Fig. 3) is satisfied or not (step S102). If, at step S102, the internal pressure value and the internal temperature value of at least one of the high-pressure tanks 202, 204 reach the boundary line Th, it is determined that the internal pressures and the internal temperatures of the high-pressure tanks 202, 204 satisfy the reference condition (step S102: Yes). The temperatures measured with the temperature sensors 93, 94 are used as the internal temperatures of the high-pressure tanks 202, 204. If the internal pressures and the internal temperatures of the high-pressure tanks 202, 204 do not satisfy the reference condition (step S102: No), the control section 80 again determines whether the respective residual amounts of hydrogen in the high-pressure tanks 202, 204 are below the predetermined threshold P1 or not (step S101).

[0034] If the internal pressures and temperatures of the high-pressure tanks 202, 204 satisfy the reference condition (step S102: Yes), the control section 80 instructs the notification section 84 to execute notification (step S103). Here, the case where the internal pressures and temperatures satisfy the reference condition may correspond, for example, to a case where the vehicle continuously runs at an internal temperature of -40°C or less, so that the internal pressures decrease due to the consumption of the gases in the high-pressure tanks 202, 204, and the internal temperatures further decrease due to adiabatic expansion. The notification may be executed, for example, to notify that one of the high-pressure tank 202 and the high-pressure tank 204 that satisfies the reference condition needs to be filled with the fuel gas.Furthermore, even in a case where only one of the high-pressure tank 202 and the high-pressure tank 204 meets the reference condition, notification may be executed to notify that both the high-pressure tank 202 and the high-pressure tank 204 need to be filled with the fuel gas. The notification control is terminated when the notification is executed. Note that the notification by the notification section 84 may continue until the fuel gas is filled into the high-pressure tanks 202, 204, or may be terminated after a predetermined period of time has elapsed.

[0035] Meanwhile, if the internal pressure condition that the internal pressures of the high-pressure tanks 202, 204 reach the predetermined threshold P1 is met at step S101 (step S101: Yes), the control section 80 instructs the notification section 84 to execute the notification without referring to the data map (step S103). That is, in this case, the control section 80 causes the notification section 84 to execute the notification regardless of whether the internal temperatures and internal pressures of the high-pressure tanks 202, 204 satisfy the reference condition or not.

[0036] For example, the internal pressure of the high pressure tank 200 at a Fig. 3, the internal pressure and temperature of the high-pressure tank 200 do not meet the reference condition (step S102: No). For this reason, at the combination point A shown in FIG. 3, the control section 80 determines that the high-pressure tank 200 does not need to be filled with the fuel gas, so the control section 80 does not instruct the notification section 84 to execute the notification.

[0037] In a case where the fuel gas is started from the Fig. 3, when the fuel gas is consumed rapidly, the fuel gas in the high-pressure tank 200 expands adiabatically with the consumption of the fuel gas, and the internal temperature drops sharply, so that the combination point A can be shifted to a combination point B. In this case, the internal pressure of the high-pressure tank 200 is equal to or higher than the threshold P1 (step S101: No), but the internal pressure and temperature of the high-pressure tank 200 satisfy the reference condition (step S102: Yes). For this reason, at the combination point B, the control section 80 determines that the high-pressure tank 200 needs to be filled with the fuel gas, so the control section 80 instructs the notification section 84 to execute the notification (step S103).

[0038] However, in a case where the fuel gas is supplied from the Fig. 3, when the fuel gas is consumed slowly, the high-pressure tank 200 is heated by, for example, an outside temperature, so that the decrease in the internal temperature of the high-pressure tank 200 is reduced, resulting in the combination point A being able to shift to a combination point C. In this case, the internal pressure of the high-pressure tank 200 has the same value as the internal pressure at the combination point B, but since the internal temperature is high, the internal pressure and the internal temperature of the high-pressure tank 200 do not satisfy the reference condition (step S102: No). For this reason, the control section 80 does not instruct the notification section 84 at the combination point C to execute the notification.Further, in a case where the fuel gas continues to be consumed from the combination point C and the combination point C is shifted to a combination point D, the internal pressure of the high-pressure tank 200 is smaller than the threshold P1 (step S101: Yes), and therefore the control section 80 instructs the notification section 84 to execute the notification (step S103).

[0039] In the first embodiment described above, the control section 80 determines whether the stress induced in the resin liner 210 due to the difference in the contraction amount between the resin liner 210 and the reinforcing layer 220 satisfies the reference condition. The difference is caused by changes in the internal temperature and pressure. Here, the reference condition is that the internal temperature and pressure of the resin liner 210 reach the boundary line Th indicating a combination of a predetermined reference internal temperature and a predetermined reference internal pressure before the stress induced in the resin liner 210 becomes a stress that damages the resin liner 210.When the reference condition is satisfied, the control section 80 determines that the high-pressure tank 200 needs to be filled with the fuel gas, and the control section 80 causes the notification section 84 to notify that the high-pressure tank 200 needs to be filled with the fuel gas. For this reason, even in a case where there is a difference in the contraction amount between the resin liner 210 and the reinforcing layer 220, the fuel cell system 100 can reduce the possibility of damage to the resin liner 210. Here, even under a low-temperature environment where a gap is easily formed between the resin liner 210 and the reinforcing layer 220, the fuel cell system 100 can reduce the possibility of damage to the resin liner 210. Accordingly, the fuel cell system 100 can achieve a higher fuel consumption compared to a case where the difference in the contraction amount shown in FIG. Fig. 4 is not performed, it can be used in a low-temperature environment. Furthermore, even in a case where a shape in which a gap is easily formed between the resin liner 210 and the reinforcing layer 220, such as an elongated shape with a small diameter, is adopted as the shape of the high-pressure tanks 202, 204, the possibility of the resin liner 210 being damaged can be reduced by the control at the time of use. Accordingly, a degree of freedom in selecting the shape of the high-pressure tanks 202, 204 is improved.

[0040] Further, in the first embodiment described above, the control section 80 determines whether the internal pressure condition that the internal pressure exceeds the predetermined threshold P1 ( Fig. 3) is met or not. When the internal pressure condition is met, the control section 80 determines that the high-pressure tank 200 needs to be filled with the fuel gas, regardless of whether the reference condition is met or not, and the control section 80 causes the notification section 84 to notify that the high-pressure tank 200 needs to be filled with the fuel gas. For this reason, in the fuel cell system 100, it is possible to restrict a situation such that a residual amount of the fuel gas is greatly reduced from a predetermined amount. Accordingly, the possibility that the fuel cell system 100 cannot generate electric power due to a shortage of the fuel gas can be reduced.

[0041] Furthermore, in the first embodiment described above, the control section 80 executes the notification control using both the internal temperature and the internal pressure. For example, in a case where the notification is executed when the internal temperature is a predetermined value or less, the notification can also be executed at an internal pressure at which stress that damages the resin liner 210 is not generated. Also, for example, in a case where the notification is executed when the internal pressure is a predetermined value or less, the notification can also be executed at an internal temperature at which stress that damages the resin liner 210 is not generated.Meanwhile, in the fuel cell system 100, a combination of the internal temperature and pressure at which a gap might be formed between the resin liner 210 and the reinforcing layer 220 can be more accurately controlled. Accordingly, the possibility of notification being executed at a combination of the internal temperature and pressure that does not generate stress that damages the resin liner 210 can be reduced. Accordingly, in a fuel cell vehicle equipped with the fuel cell system 100, it is possible to improve a travel distance compared to a case where notification control is executed using only one of the internal temperature and pressure.

[0042] Further, in the first embodiment described above, the control section 80 executes the notification control using the data map stored in advance in the storage section 82, so that a time required for processing in the notification control can be reduced. B. Second embodiment:

[0043] Fig. 5 is a schematic view of a high-pressure tank 400 according to the second embodiment. Fig. 5 illustrates a cross-sectional structure obtained when the high-pressure tank 400 is cut along a central axis CX of the high-pressure tank 400. The high-pressure tank 400 used in the fuel cell system 100 of the second embodiment differs from the high-pressure tank 200 of the first embodiment in that a central part of the high-pressure tank 400 in the longitudinal direction thereof is provided with a connecting part 410 in which the resin liner 210 and the reinforcing layer 220 are connected to each other via the circumferential direction of the resin liner 210. In the following description, the same component as that in the first embodiment bears the same reference numeral as in the first embodiment, and a detailed description thereof is omitted.

[0044] The resin liner 210 and the reinforcing layer 220 at the connecting part 410 are bonded to each other, for example, so that a mold release agent is not applied to a portion of the resin liner 210 that will become the connecting part 410 at the time of manufacturing the high-pressure tank 400. In this case, the epoxy resin contained in the reinforcing layer 220 serves as an adhesive that bonds the reinforcing layer 220 to the resin liner 210. Further, projections and recesses may be formed by performing a grinding process or the like on the portion that will become the connecting part 410 to increase a bonding area. In this case, a stronger bond is achieved at the connecting part 410.

[0045] Since the connecting part 410 is provided, the high-pressure tank 400 can prevent a change in the position of the resin liner 210 with respect to the reinforcing layer 220 even when the resin liner 210 repeatedly contracts and expands. This correspondingly reduces the amount of change in the size of a gap at the dome portion 212, 214 when the positional relationship between the resin liner 210 and the reinforcing layer 220 changes due to expansion and contraction of the resin liner 210. Accordingly, a stress induced in the resin liner 210 can be easily calculated compared to a case where the position of the resin liner 210 with respect to the reinforcing layer 220 might change.

[0046] Fig. 6 is a diagram illustrating a data map of the internal temperature and internal pressure of the resin liner 210 in the second embodiment. Fig. 7 is a schematic view for describing a state of the connecting part 410 in a case where the internal temperature and pressure of the resin liner 210 fall within a stress occurrence range A11. A data map in the present embodiment includes a first range A1, a second range A2, the stress occurrence range A11, and a boundary line TH, which are defined by a different condition from the first embodiment. In the present embodiment, the first range A1 corresponds to a range indicating that stress induced in the connecting part 410 due to contraction of the resin liner 210 may damage the resin liner 210. Fig. 6, the first region A1 corresponds to a region indicated by line hatching and cross hatching. The second region A2 corresponds to a region having a higher temperature and a higher pressure than the first region A1. A region indicated by line hatching in the first region A1 corresponds to the stress occurrence region A11. The stress occurrence region A11 in the present embodiment indicates a combination of the internal temperature and the internal pressure at which a stress caused in the joint part 410 by a difference in the contraction amount between the resin liner 210 and the reinforcing layer 220 becomes a stress that damages the resin liner 210. The difference is caused by changes in the internal temperature and the internal pressure.In the present embodiment, the stress occurrence area A11 is determined based on a result of simulation of the stress induced in the connecting part 410 at the time of contraction of the resin liner 210.

[0047] In the present embodiment, when the resin liner 210 contracts in the radial direction, a stress corresponding to a contraction force is generated because the connecting part 410 is connected to the reinforcing layer 220. When the contraction of the resin liner 210 in the radial direction is large, a part of the connection between the connecting part 410 and the reinforcing layer 220 is released, so that a connection area between the connecting part 410 and the reinforcing layer 220 decreases, as shown in Fig. 7. In this case, stress is concentrated at a portion connected to the reinforcing layer 220 at the connecting part 410 of the resin liner 210, resulting in a stress induced at the connecting part 410 becoming a stress that damages the resin liner 210. Note that a gap between the resin liner 210 and the smaller-diameter R reinforcing layer 220 of the high-pressure tank 400 tends to be easily formed due to contraction in the radial direction.

[0048] The boundary line TH, which separates the first area A1 and the second area A2, as shown in Fig. 6, is defined by a combination of a predetermined reference internal temperature and a predetermined reference internal pressure before the stress induced in the connecting part 410 becomes the stress that damages the resin liner 210. The limit line TH can be determined, for example, by adding a safety ratio to the stress occurrence range A11. For example, the limit line TH can also correspond to a combination of the internal temperature and the internal pressure at which a contraction or expansion of the resin liner 210 due to a change in the internal temperature is balanced by a contraction or expansion of the resin liner 210 due to a change in the internal pressure.In this case, at the combination of the internal temperature and pressure on the boundary line TH, no gap is formed between the resin liner 210 and the reinforcement layer 220, and no pressure caused by expansion of the resin liner 210 is applied to the reinforcement layer 220. As the combination of the internal temperature and pressure approaches the stress event area A11 across the boundary line TH, a gap begins to form between the resin liner 210 and the reinforcement layer 220.

[0049] The second embodiment described above has a similar configuration to the first embodiment, thereby achieving an effect similar to the first embodiment. Furthermore, in the second embodiment, the control section 80 performs notification control ( Fig. 4) When the internal temperature and internal pressure fall within the first range A1, which indicates a combination where stress concentration may occur at the connecting part 410 (step S102: Yes), the notification is executed (step S103). For this reason, the fuel cell system 100 can execute the notification before the stress induced at the connecting part 410 becomes the stress that damages the resin liner 210. This prevents breakage of the resin liner 210, particularly a part near the connecting part 410, due to stress applied to the connecting part 410. C. Further embodiments:C1. First of the further embodiments:

[0050] In the above embodiment, the fuel cell system 100 includes two high-pressure tanks 202, 204, but the fuel cell system 100 is not limited thereto. For example, the fuel cell system 100 may include one high-pressure tank or three or more high-pressure tanks. In a case where the fuel cell system 100 includes three or more high-pressure tanks, if the internal pressures of all the high-pressure tanks provided in the fuel cell system 100 are lower than the threshold P1, it is determined that the internal pressure condition is met at step S101 in the notification control ( Fig. 4) is satisfied (step S101: Yes). Further, at step S102, when the internal pressure and internal temperature of at least one of the high-pressure tanks provided in the fuel cell system 100 reach the boundary line Th, it is determined that the internal pressures and internal temperatures of the high-pressure tanks satisfy the reference condition (step S102: Yes). C2. Second of the further embodiments:

[0051] In the above embodiments, the fuel gases in the two high-pressure tanks 202, 204 are adjusted to be consumed so that the internal pressures of the high-pressure tanks 202, 204 become equal. However, the consumption of the fuel gases is not limited to this. For example, the fuel gas may be consumed only from one of the high-pressure tanks, and when the remaining amount of the fuel gas of one of the high-pressure tanks becomes less than a predetermined amount, the consumption of the fuel gas from one of the high-pressure tanks may be stopped and the consumption of the fuel gas from the other of the high-pressure tanks may be started. In this case, at step S101 in the notification control ( Fig.4), if the internal pressure of the high-pressure tank from which the fuel gas is finally consumed is less than the threshold P1, it is determined that the internal pressure condition is met (step S101: Yes). Further, at step S102, if the internal pressure and internal temperature of the high-pressure tank from which the fuel gas is finally consumed reach the boundary line Th, it is determined that the internal pressures and internal temperatures of the high-pressure tanks 202, 204 satisfy the reference condition (step S102: Yes). C3. Third of the further embodiments:

[0052] In the above embodiments, the control section 80 executes the notification control using the data map stored in advance in the storage section 82. However, the control section 80 is not limited to this. For example, combinations of a predetermined reference internal temperature and a predetermined reference internal pressure may be stored as a list in the storage section 82, and the control section 80 may determine whether or not the thus stored list includes a combination corresponding to the internal temperature and the internal pressure. In this case, if the internal temperature and the internal pressure correspond to one of the combinations in the list, the control section 80 may determine that the reference condition is satisfied. Further, the data map may not be stored in the storage section 82, for example.In this case, the control section 80 may execute notification control using a data map stored on a server provided externally to the fuel cell system 100. A contraction amount of the resin liner 210 may be calculated using the internal temperature and pressure, and when the contraction amount becomes a predetermined value or greater, notification may be executed. Furthermore, the data map may include the threshold P1. C4. Fourth of the further embodiments:

[0053] In the above embodiments, the high-pressure tanks 202, 204 provided in the fuel cell system 100 may have different lengths L and different diameters R. In this case, at the time when determining the stress occurrence range, it is preferable to use as the reference a high-pressure tank among the high-pressure tanks 202, 204 in which stress is most easily induced at the resin liner 210. For example, in the case of the first embodiment, it is preferable to use as the reference a high-pressure tank in which a gap is easily formed between the resin liner 210 and the reinforcing layer 220. Also, for example, in the case of the second embodiment, it is preferable to use as the reference a high-pressure tank in which stress concentration is most easily induced at the connecting part 410, that is, a high-pressure tank with a smallest diameter R.In this case, in a case where the high-pressure tanks 202, 204 provided in the fuel cell system 100 have different lengths L and different diameters R, for example, a degree of freedom in the arrangement of the high-pressure tanks 202, 204 in the fuel cell vehicle equipped with the fuel cell system 100 improves. C5. Fifth of the further embodiments:

[0054] In the above embodiments, the fuel cell system 100 includes temperature sensors 93, 94 as internal temperature acquisition sections and pressure sensors 91, 92 as internal pressure acquisition sections. However, the fuel cell system 100 is not limited to this. For example, the fuel cell system 100 may include, as the acquisition section, the pressure sensors 91, 92 and a temperature estimation section configured to estimate the internal temperature using the internal pressure. The fuel cell system 100 may also include, as the acquisition section, a pressure estimation section configured to estimate the internal pressure using the internal temperature, and the temperature sensors 93, 94 configured to measure the internal temperatures.The estimation of the internal temperature using the internal pressure and the estimation of the internal pressure using the internal temperature can be performed, for example, using a gas equation. In a case where the internal pressure or the internal temperature is estimated using the gas equation, the volume of the internal space 216 of the high-pressure tank 200 can be assumed to be a constant volume even if the internal pressure or the internal space changes. For example, the internal pressure or the internal temperature can be estimated by applying the volume of the internal space 216 of the high-pressure tank 200 under a predetermined condition (for example, a normal state) to the gas equation.Further, in this case, the fuel cell system 100 may estimate a remaining fuel gas amount in the high-pressure tank 200 using a filling amount of the fuel gas and a consumed amount of the fuel gas, and use the remaining fuel gas amount to estimate the internal pressure or the internal temperature. C6. Sixth of the further embodiments:

[0055] In the above embodiments, the temperature sensor 93, 94 is arranged in the high-pressure tank 202, 204, and the pressure sensor 91, 92 is provided in the fuel gas supply passage 34. However, the temperature sensor 93, 94 and the pressure sensor 91, 92 are not limited to this. For example, the temperature sensor 93, 94 may be provided in the fuel gas supply passage 34, and the control section 80 may acquire the internal temperature so that a correction of a temperature acquired by the temperature sensor 93, 94 is performed to remove a temperature change after the fuel gas is discharged from the high-pressure tank 202, 204. Furthermore, the pressure sensor 91, 92 may be arranged in the high-pressure tank 202, 204, for example. C7. Seventh of the further embodiments:

[0056] In the above embodiments, in a case where the internal pressures and temperatures of the high-pressure tanks 202, 204 satisfy the reference condition, the fuel cell system 100 may perform a process for restricting a power generation amount in addition to the notification by the notification section 84. The process for restricting the power generation amount may be performed, for example, by limiting an amount of fuel gas to be supplied to the fuel cell stack 20 to a predetermined amount or less. In this case, the fuel cell system 100 may reduce a consumption rate of the fuel gas after the reference condition is satisfied. Here, the fuel cell system 100 may reduce the decrease in the internal pressure and the decrease in the internal temperature in the high-pressure tank 200 due to the consumption of the fuel gas.In a case where the power generation amount limiting process is performed, the control section 80 may control the operation of each component (for example, at least one of the regulator 44, the injector 45, and the hydrogen pump 46) of the fuel gas supply / discharge mechanism 50 in addition to the operation of the notification section 84. Note that in a case where the internal pressures of the high-pressure tanks 202, 204 satisfy the internal pressure condition, the fuel cell system 100 may also perform the power generation amount limiting process.

[0057] The first to seventh of the further embodiments have a configuration similar to the first embodiment and the second embodiment, thereby achieving an effect similar to the first embodiment and the second embodiment. C8. Eighth of the further embodiments:

[0058] In the second embodiment, the connecting part 410 is formed at the central part of the high-pressure tank 400 in the longitudinal direction. However, the connecting part 410 is not limited to this. For example, the resin liner 210 and the reinforcing layer 220 may be connected to each other at other regions in addition to or instead of the central part in the longitudinal direction. Further, in the connecting part 410, the resin liner 210 and the reinforcing layer 220 are connected to each other across the circumferential direction of the resin liner 210. However, the connecting part 410 is not limited to this. For example, in the connecting part 410, the resin liner 210 and the reinforcing layer 220 may be partially connected to each other across the circumferential direction of the resin liner 210.

[0059] This disclosure is not limited to the above embodiments and can be implemented with various configurations within a range that does not deviate from the gist of the disclosure. For example, the technical features of the embodiments can be appropriately replaced or combined with the technical features of the aspects described in the summary of the invention to solve some or all of the problems described above or to achieve some or all of the above effects. Furthermore, the technical features can be appropriately deleted if the technical features have not been described as essential in this specification.

Claims

[1] Fuel cell system (100), comprising: a fuel cell stack (20) configured to generate electrical power by consuming a fuel gas; a high-pressure tank (200) having a resin liner (210) and a reinforcing layer (220) configured to cover an outer surface of the resin liner (210), the high-pressure tank (200) being filled with the fuel gas; an acquisition section configured to acquire a value of an internal pressure of the high-pressure tank (200) and a value of an internal temperature corresponding to a temperature inside the high-pressure tank (200); a notification section (84) configured to notify that the high-pressure tank (200) needs to be filled with the fuel gas; and a control section (80) configured to control an operation of the notification section (84) using the value of the internal temperature and the value of the internal pressure, wherein: the control section (80) sets a boundary line in a map of the internal temperature and the internal pressure, which boundary line divides the map into a first region and a second region, the first region indicating a possibility that a stress induced in the resin liner (210) due to a contraction of the resin liner (210) will damage the resin liner (210), the second region having a higher temperature and a higher pressure than the first region; and the control section (80), when the value of the internal temperature and the value of the internal pressure reach the limit line, causes the notification section (84) to report that the high-pressure tank (200) needs to be filled with the fuel gas. [2] The fuel cell system (100) according to claim 1, wherein the control section (80), when the value of the internal pressure reaches a predetermined threshold, causes the notification section (84) to notify that the high-pressure tank (200) needs to be filled with the fuel gas, regardless of whether the value of the internal temperature and the value of the internal pressure reach the limit line or not. [3] Fuel cell system (100) according to claim 1 or 2, wherein: the resin liner (210) comprises a connecting part (410) provided at a central part of the resin liner (210) in a longitudinal direction of the resin liner (210) to be connected to the reinforcing layer (220); and the stress in the resin lining (210) at the connecting part (410) is caused due to a contraction of the resin lining (210). [4] The fuel cell system (100) according to any one of claims 1 to 3, wherein the acquisition section comprises one of the following elements (i) to (iii): (i) a pressure sensor (91, 92) configured to obtain the value of the internal pressure and a temperature sensor (93, 94) configured to obtain the value of the internal temperature; (ii) the pressure sensor (91, 92) configured to obtain the value of the internal pressure, and a temperature estimation section configured to estimate the value of the internal temperature using the value of the internal pressure; and (iii) the temperature sensor (93, 94) configured to acquire the value of the internal temperature, and a pressure estimating section configured to estimate the value of the internal pressure using the value of the internal temperature. [5] Fuel cell system (100) according to claim 2, wherein: the high-pressure tank (200) is constructed by a plurality of high-pressure tanks (202, 204); and when the value of the internal temperature and the value of the internal pressure of at least one of the high-pressure tanks (202, 204) reach the boundary line, the control section (80) causes the notification section (84) to report that the at least one of the high-pressure tanks (202, 204) needs to be filled with the fuel gas. [6] The fuel cell system (100) according to claim 5, wherein, when the respective value of the internal pressures of the high-pressure tanks (202, 204) reaches the predetermined threshold, the control section (80) causes the notification section (84) to notify that the at least one of the high-pressure tanks (202, 204) needs to be filled with the fuel gas, regardless of whether the value of the internal temperature and the value of the internal pressure reach the boundary line or not. [7] Fuel cell system (100) according to claim 5, wherein: the high-pressure tanks (202, 204) are connected to the fuel cell stack (20) via a fuel gas supply passage (34); the fuel gas supply passage (34) is provided with opening and closing valves (432, 434); and the control section (80) controls the opening and closing valves (432, 434) at a time of power generation of the fuel cell stack (20) so that the high-pressure tanks (202, 204) have the same internal pressure. [8] Fuel cell system (100) according to claim 5, wherein: the high-pressure tanks (202, 204) are connected to the fuel cell stack (20) via a fuel gas supply passage (34); the fuel gas supply passage (34) is provided with opening and closing valves (432, 434); the control section (80) controls the opening and closing valves (432, 434) at a time of power generation of the fuel cell stack (20) so that the internal pressure of a second high-pressure tank among the high-pressure tanks (202, 204) does not decrease until the internal pressure of a first high-pressure tank among the high-pressure tanks (202, 204) decreases to a predetermined pressure value; and when the value of the internal pressure and the value of the internal temperature of the second high-pressure tank reach the limit line, the control section (80) causes the notification section (84) to report that at least the second high-pressure tank needs to be filled with the fuel gas. [9] The fuel cell system (100) according to claim 8, wherein, when the value of the internal pressure of the second high-pressure tank reaches the predetermined threshold, the control section (80) causes the notification section (84) to notify that at least the second high-pressure tank needs to be filled with the fuel gas, regardless of whether the value of the internal temperature and the value of the internal pressure reach the boundary line or not. [10] A control method for a fuel cell system (100), the control method comprising: Obtaining a value of an internal pressure of a high-pressure tank (200) and a value of an internal temperature corresponding to a temperature inside the high-pressure tank (200), wherein the high-pressure tank (200) comprises a resin liner (210) and a reinforcing layer (220) configured to cover an outer surface of the resin liner (210), wherein the high-pressure tank (200) is filled with a fuel gas to be consumed for power generation by a fuel cell stack (20); Setting a boundary line in a map of the internal temperature and the internal pressure, which divides the map into a first region and a second region, wherein the first region indicates a possibility that a stress induced in the resin liner (210) due to a contraction of the resin liner (210) will damage the resin liner (210), wherein the second region corresponds to a region having a higher temperature and a higher pressure than the first region; and Initiating a notification section (84) to notify that the high pressure tank (200) needs to be filled with the fuel gas when the internal temperature value and the internal pressure value reach the limit line.

Images