JP2018152179A - Fuel cell system and method for operating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system arranged so that a start-up allowable frequency of a fuel cell can be utilized completely.SOLUTION: A fuel cell system (10) comprises a fuel cell (101) and a controller (116). The controller (116) controls the operation of the fuel cell (101). The controller (116) decides a start-up allowable frequency based on a predetermined start-up frequency of the fuel cell(101) per unit time, a cumulative energization time from the start of energization of the fuel cell(101) to a present moment, and a number of cumulative start-ups of the fuel cell (101) up to now. When the start-up allowable frequency is less than a predetermined value, the controller (116) decides that the fuel cell (101) stays in such a start-up protection state that the start-up of the fuel cell(101) should be banned. When it is decided that the fuel cell is in the start-up protection state in a period during which the fuel cell (101) remains stopped, the controller (116) bans the start-up of the fuel cell 101.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a fuel cell system and a method for operating the fuel cell system.

  Conventionally, a service life (for example, 10 years) is determined for a fuel cell system. In addition, a technique for operating a fuel cell system in consideration of the service life is known.

  For example, Patent Document 1 describes a fuel cell power generator that can realize a cumulative operation time corresponding to a service life in an operation elapsed period corresponding to a service life and satisfy a planned device life. The fuel cell power generator includes a fuel cell, exhaust heat recovery means, operation means, and control means. The control means controls the fuel cell and the heat recovery means in either the automatic operation mode or the manual operation mode to operate the fuel cell power generator. In the automatic operation mode, the fuel cell power generator according to the operation start time and the stop time planned in consideration of at least one of power demand and heat demand, the durable operation time of the fuel cell, and the planned service life Is operated. In the manual operation mode, the operation of the fuel cell power generator is started or stopped according to an instruction from the operation unit of the operation means. In the automatic operation mode, the control means causes the operation to limit the operation time per unit time within a predetermined allowable operation time for each predetermined period. Further, the control means outputs a warning to refrain from driving in the manual operation mode when the ratio of the cumulative operation time to the operation elapsed period from the start of the operation is equal to or higher than the first predetermined level.

  Further, Patent Document 2 describes a fuel cell system capable of ensuring a life up to the useful life even when starting and stopping are frequently performed for reasons such as user convenience. This fuel cell system includes a fuel cell and a control unit. The control unit includes a measurement unit, a calculation unit, a determination unit, and an activation restriction unit. The measuring means measures the current cumulative number of stops of the fuel cell as the current cumulative number of stops. As the cumulative operation time of the fuel cell increases until it reaches a predetermined useful cumulative operation time, the allowable stop count that is the allowable upper limit value of the cumulative stop count is gradually increased to the predetermined allowable allowable stop count, The relationship with the allowable number of stops is shown. Based on this relationship, the calculation means generates a current allowable stop count that is the allowable stop count of the fuel cell from the current cumulative operation time that is the current cumulative operation time of the fuel cell. The determination means sets the current allowable stop count as the reference stop count, and determines that the current cumulative stop count is equal to or greater than the reference stop count as an abnormal stop count. The start restriction unit prohibits the restart of the fuel cell until a predetermined reset operation is performed after it is determined that the number of stops is abnormal.

JP 2011-170985 A Japanese Patent No. 5911366

  According to the techniques described in Patent Document 1 and Patent Document 2, there is room for improvement from the viewpoint of fully utilizing the allowable number of times of starting the fuel cell. Therefore, an object of the present disclosure is to provide a fuel cell system that can fully use the allowable number of times the fuel cell can be activated.

This disclosure
A fuel cell that generates electricity using an oxidant gas and a hydrogen-containing gas;
A controller for controlling the operation of the fuel cell,
The controller is
The allowable number of activations based on the relationship between the predetermined number of activations of the fuel cell per unit time, the cumulative energization time from the start of energization of the fuel cell to the present, and the cumulative number of activations of the fuel cell up to the present Decide
When the allowable number of activations is less than a predetermined value, it is determined that the fuel cell is in an activation protection state in which activation of the fuel cell should be prohibited,
Prohibiting startup of the fuel cell when it is determined that the fuel cell is in the startup protection state during the stop period of the fuel cell;
A fuel cell system is provided.

  According to the fuel cell system of the present disclosure, the allowable number of times of starting the fuel cell can be fully utilized.

FIG. 1 is a configuration diagram of a fuel cell system according to an embodiment of the present disclosure. FIG. 2 is a functional block diagram of the controller of the fuel cell system shown in FIG. FIG. 3 is a diagram showing a hardware configuration of the controller of the fuel cell system shown in FIG. FIG. 4A is a flowchart showing an example of the operation of the fuel cell system. FIG. 4B is a flowchart showing an example of the operation of the fuel cell system. FIG. 4C is a flowchart illustrating an example of the operation of the fuel cell system.

(Knowledge that became the basis of this disclosure)
The fuel cell system includes, for example, a hydrogen production device, a fuel cell, and a heat recovery device. The hydrogen production apparatus has a reformer that generates a hydrogen-containing gas from a raw material gas such as natural gas or liquefied petroleum gas (LPG). The fuel cell generates power using a hydrogen-containing gas. The heat recovery device includes a hot water storage tank for recovering heat generated during power generation. In such a fuel cell system, if starting and stopping are frequently repeated, deterioration of equipment such as a reformer may progress due to a heat cycle or the like, and the service life of the fuel cell may not be satisfied. Further, in a fuel cell stack having a solid polymer membrane, when the fuel cell system is operated continuously for a long time, there is a possibility that performance degradation may occur due to accumulation of contaminants and the like.

  Such a fuel cell system is operated according to various operation modes such as an energy saving power generation mode, a reserved power generation mode, a manual power generation mode, and a hot water storage power generation mode. In the energy saving power generation mode, loads such as a power load and a hot water supply load are measured, an operation plan is made using the measured loads, and power is automatically generated according to the operation plan. In the reserved power generation mode, power generation is started at a time specified by the user. In the manual power generation mode, power generation is performed according to an instruction input by the user. In the hot water storage power generation mode, priority is given to securing a predetermined heat storage amount in the hot water storage tank. In the fuel cell system, for example, an operation plan in which an allowable operation time per predetermined time is determined in advance based on the service life so as to satisfy the service life (for example, 10 years) is determined. Driven. However, in the operation modes such as the reserved power generation mode, the manual power generation mode, and the hot water storage power generation mode, the fuel cell system is operated without following this operation plan. For this reason, when operation modes such as the reserved power generation mode, manual power generation mode, and hot water storage power generation mode are selected, depending on the size of the power load and hot water supply load, the fuel cell system may be operated more than expected and There is a possibility that the number of years cannot be satisfied. On the other hand, in the fuel cell system, the operation is significantly less than expected, and the allowable operation time corresponding to the service life may not be fully utilized, and the service life may be reached in a state where there is a margin in the device life.

  According to the technique described in Patent Document 1, a warning is output so as to refrain from the operation in the manual operation mode when the ratio of the accumulated operation time to the operation elapsed period is equal to or higher than the first predetermined level. Thereby, the user recognizes a warning that refrains from driving in the manual operation mode, and is more likely to refrain from manual operation or to shorten the operation time than in the automatic operation mode. As a result, while properly using the two operation modes of the automatic operation mode and the manual operation mode, the accumulated operation time corresponding to the service life can be realized in the operation elapsed time corresponding to the service life, and the planned device life can be satisfied. However, in the technique described in Patent Document 1, even when there is a margin in the allowable number of times of activation of the fuel cell, the operation time per unit time is limited to a predetermined operation allowable time for each predetermined period. For this reason, there may be a state in which the amount of exhaust heat recovered by the exhaust heat recovery means is small when heat demand is generated. In this case, it is necessary to meet heat demand using heat other than exhaust heat, which is not desirable from the viewpoint of energy saving. In addition, there is a surplus in the allowable number of activations of the fuel cell, and even when the user desires to generate power, there is a possibility that the user may refrain from driving in the manual operation mode.

  According to the technique described in Patent Document 2, the current allowable stop count is generated in consideration of the durable cumulative operation time, and even if there is a margin in the allowable start count of the fuel cell, the cumulative operation time is the durable cumulative operation time. If this value is reached, activation of the fuel cell is not permitted.

  Accordingly, the present inventors have studied the technology that can fully utilize the allowable number of times of starting the fuel cell in the fuel cell system, and devised the fuel cell system of the present disclosure.

The first aspect of the present disclosure is:
A fuel cell that generates electricity using an oxidant gas and a hydrogen-containing gas;
A controller for controlling the operation of the fuel cell,
The controller is
The allowable number of activations based on the relationship between the predetermined number of activations of the fuel cell per unit time, the cumulative energization time from the start of energization of the fuel cell to the present, and the cumulative number of activations of the fuel cell up to the present Decide
When the allowable number of activations is less than a predetermined value, it is determined that the fuel cell is in an activation protection state in which activation of the fuel cell should be prohibited,
Prohibiting startup of the fuel cell when it is determined that the fuel cell is in the startup protection state during the stop period of the fuel cell;
A fuel cell system is provided.

  According to the first aspect, the controller includes a predetermined number of start times of the fuel cell per unit time, a cumulative energization time from the start of energization of the fuel cell to the present, a cumulative number of times of start of the fuel cell up to the present, The allowable number of activations is determined based on the relationship. In addition, when the allowable number of activations is less than a predetermined value, the activation of the fuel cell is prohibited. For this reason, if the allowable number of activations is equal to or greater than a predetermined value, the fuel cell is permitted to be activated. In addition, since the allowable number of times of activation is determined regardless of the durable accumulated operation time, the fuel cell is permitted to be activated if the permitted number of activations is equal to or greater than a predetermined value even after the durable accumulated operation time has elapsed. As a result, in the fuel cell system, the allowable number of times of starting the fuel cell can be fully utilized.

  According to a second aspect of the present disclosure, in addition to the first aspect, a heat recovery device that recovers and stores exhaust heat during power generation of the fuel cell, and an operation panel having at least one of a notification device and a display device are further provided. And the controller is responsive to an automatic operation mode in which the fuel cell is operated according to an exhaust heat recovery level indicating a level of heat stored in the heat recovery device and an instruction input to the operation panel. A fuel cell system is provided that operates the fuel cell and the heat recovery device in accordance with any one of a manual operation mode in which the operation of the fuel cell is started or stopped. According to the second aspect, the exhaust heat at the time of power generation of the fuel cell can be recovered and stored by the heat recovery device, and the fuel cell system can be operated according to one of the automatic operation mode and the manual operation mode.

  In addition to the second aspect, the third aspect of the present disclosure further includes a sensor that detects a physical quantity for determining the exhaust heat recovery level, and the controller operates the fuel cell system in the automatic operation mode. The exhaust heat recovery level is determined based on information indicating a detection result of the sensor, and the fuel cell is in the start-up protection state when the exhaust heat recovery level is higher than a first level. And determines that the fuel cell is in the startup protection state when the exhaust heat recovery level is equal to or lower than the first level and the allowable startup count is less than the predetermined value. Provide a system. According to the third aspect, in the automatic operation mode, when the exhaust heat recovery level is higher than the first level, the start of the fuel cell is prohibited, so that the exhaust heat recovery level reaches the upper limit immediately after the start of the fuel cell. Can be prevented. Further, when the exhaust heat recovery level is equal to or lower than the first level, the fuel cell is permitted to be activated if the allowable number of times of activation is equal to or greater than a predetermined value.

  In addition to the second aspect, the fourth aspect of the present disclosure further includes a sensor that detects a physical quantity for determining the exhaust heat recovery level, and the controller operates the fuel cell system in the manual operation mode. When the activation instruction is input to the operation panel, the exhaust heat recovery level is determined based on information indicating the detection result of the sensor, and the exhaust heat recovery level is higher than the second level. Determining that the fuel cell is in the startup protection state, the exhaust heat recovery level is less than or equal to the second level, and the allowable number of startups is less than the predetermined value, the fuel cell is Provided is a fuel cell system that determines that it is in a startup protection state. According to the fourth aspect, when the exhaust heat recovery level is equal to or lower than the second level, the fuel cell is allowed to start if the allowable start count is equal to or greater than a predetermined value. For this reason, the fuel cell system is easily operated in a state where the user's intention is prioritized by appropriately determining the second level.

  According to a fifth aspect of the present disclosure, in addition to any one of the second aspect to the fourth aspect, when the controller determines that the fuel cell is in the start-up protection state, the fuel cell A fuel cell system is provided that causes at least one of the notification device and the display device to output information indicating that it is in the activation protection state. According to the fifth aspect, it is possible to notify the user that the fuel cell is in the startup protection state.

The sixth aspect of the present disclosure is:
A method for operating a fuel cell system, comprising:
The permissible number of activations is determined based on the relationship between the predetermined number of fuel cell activations per unit time, the cumulative energization time from the start of energization of the fuel cell to the present, and the cumulative number of activations of the fuel cell up to the present. Decide
When the allowable number of activations is less than a predetermined value, it is determined that the fuel cell is in an activation protection state in which activation of the fuel cell should be prohibited,
Prohibiting activation of the fuel cell when it is determined that the fuel cell is in the activation protection state during the stop period of the fuel cell;
Provide a method.

  According to the sixth aspect, similar to the first aspect, the allowable number of activations of the fuel cell can be fully utilized in the fuel cell system.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the following embodiment.

  As shown in FIG. 1, the fuel cell system 10 includes a fuel cell 101 (fuel cell unit) and a controller 116. The fuel cell 101 generates power using an oxidant gas and a hydrogen-containing gas. The controller 116 controls the operation of the fuel cell 101. The controller 116 has a relationship between a predetermined number of activations of the fuel cell 101 per unit time, a cumulative energization time from the start of energization of the fuel cell 101 to the present, and a cumulative number of activations of the fuel cell 101 up to the present. Based on this, the allowable number of activations is determined. The controller 116 determines that the fuel cell 101 is in an activation protection state in which the activation of the fuel cell 101 should be prohibited when the allowable number of activations is less than a predetermined value. When the controller 116 determines that the fuel cell is in the start protection state during the stop period of the fuel cell, the controller 116 prohibits the start of the fuel cell 101.

  In the fuel cell system 10, activation of the fuel cell 101 is prohibited when the allowable number of activations is less than a predetermined value, and activation of the fuel cell 101 is permitted when the allowable number of activations is greater than or equal to a predetermined value. Since the allowable number of times of activation is determined regardless of the durable accumulated operation time, the fuel cell 101 is permitted to be activated if the permitted number of activations is equal to or greater than a predetermined value even after the durable accumulated operation time has elapsed. As a result, the fuel cell 101 can be fully utilized in the fuel cell system 10 with the allowable number of activations.

  As shown in FIG. 1, the fuel cell 101 includes, for example, an oxidant gas supply device 103, a hydrogen-containing gas supply device 104, a fuel cell stack 105, an inverter 106, a heat exchanger 107, and a first pump 108. The second pump 109 is provided. The oxidant gas supply device 103 sends an oxidant gas such as air toward the fuel cell stack 105. The oxidant gas supply device 103 is a blower, for example. The oxidant gas supply device 103 and the fuel cell stack 105 are connected by a flow path of oxidant gas. The hydrogen-containing gas supply device 104 includes a reformer that generates a hydrogen-containing gas from a raw material gas such as natural gas or LPG, and the hydrogen-containing gas generated by the reformer is directed toward the fuel cell stack 105. send. The hydrogen-containing gas supply device 104 may be, for example, a combination of a pressure vessel in which a hydrogen-containing gas is stored at a high pressure and a regulator attached to the pressure vessel. The hydrogen-containing gas supply device 104 and the fuel cell stack 105 are connected by a hydrogen-containing gas flow path. The cells constituting the fuel cell stack 105 are, for example, solid polymer fuel cells.

  The fuel cell stack 105 generates power by reacting, for example, an oxidant gas supplied from the oxidant gas supply device 103 and a hydrogen-containing gas supplied from the hydrogen-containing gas supply device 104. The fuel cell stack 105 is electrically connected to the inverter 106. The inverter 106 converts DC power generated by power generation in the fuel cell stack 105 into AC power. The inverter 106 is electrically connected to a power load 115 such as an electric lamp or an electric appliance, and power is consumed by the power load 115.

  Heat is generated by power generation in the fuel cell stack 105. Therefore, for example, the cooling water circuit is configured by connecting the fuel cell stack 105, the heat exchanger 107, and the first pump 108 in a ring shape by piping or the like. The first pump 108 supplies cooling water toward the fuel cell stack 105. The cooling water supplied to the fuel cell stack 105 is supplied to the heat exchanger 107 after cooling the fuel cell stack 105. In the heat exchanger 107, the cooling water is cooled by heat exchange with another heat medium (for example, water), and the cooled cooling water is sent again to the fuel cell stack 105 by the first pump 108. The second pump 109 sends a heat medium for cooling the cooling water of the fuel cell stack 105 to the heat exchanger 107 in the heat exchanger 107. Thereby, the temperature of the fuel cell stack 105 is maintained in a desired range.

  As shown in FIG. 1, the fuel cell system 10 further includes, for example, a heat recovery device 102 (heat recovery unit) and an operation panel 117. The heat recovery device 102 recovers and stores the exhaust heat generated when the fuel cell 101 generates power. The operation panel 117 includes at least one of the alarm device 120 and the display device 118. The controller 116 operates the fuel cell 101 and the heat recovery apparatus 102 according to one of the automatic operation mode and the manual operation mode. The automatic operation mode is an operation mode in which the fuel cell 101 is operated in accordance with the exhaust heat recovery level indicating the level of the amount of heat stored in the heat recovery apparatus 102. The manual operation mode is an operation mode in which the operation of the fuel cell 101 is started or stopped in accordance with an instruction input to the operation panel 117.

  As shown in FIG. 1, the heat recovery apparatus 102 includes, for example, a three-way valve 110, a hot water storage tank 111, a mixing valve 112, and a heater 113. The hot water storage tank 111 is connected to, for example, city water 130, and water is supplied from the city water 130 to the hot water storage tank 111. The hot water storage tank 111 is connected to the inlet of the second pump 109 by piping. When the second pump 109 is activated, the water stored in the hot water storage tank 111 is supplied to the heat exchanger 107. In the heat exchanger 107, the water supplied from the hot water storage tank 111 and the cooling water of the fuel cell stack 105 exchange heat to heat the water supplied from the hot water storage tank 111. The water heated in the heat exchanger 107 returns to the hot water storage tank 111 through the three-way valve 110. In this way, the heat recovery apparatus 102 recovers and stores the exhaust heat generated when the fuel cell 101 generates power. When heat demand such as hot water is generated, the water stored in the hot water storage tank 111 is mixed with water supplied from city water as necessary and passes through the mixing valve 112. The water that has passed through the mixing valve 112 is heated by the heater 113 as necessary, and then passes through the hot water tap 135 to be supplied with hot water.

  As shown in FIG. 1, the controller 116 is connected to a specific component of the fuel cell 101 by wire or wireless so that predetermined signals such as a control signal and a detection signal can be transmitted and received. For example, the controller 116 is connected to a specific component of the heat recovery apparatus 102 by wire or wireless so that predetermined signals such as a control signal and a detection signal can be transmitted and received. For example, the controller 116 can perform transmission / reception of a predetermined signal such as a signal for outputting predetermined information to the display device 118 or the alarm device 120 and a signal indicating an instruction input to the operation panel 117 by wired or wireless operation. Connected to the panel 117. The operation panel 117 further includes, for example, operation keys 119 for inputting instructions. The operation key 119 may be a physical key or a software key displayed on the display device 118.

  As shown in FIG. 2, the controller 116 includes an operation control unit 202, an operation plan calculation unit 203, an activation protection determination unit 204, an allowable activation number calculation unit 205, an accumulated activation number storage unit 206, and an accumulated energization time. The storage unit 207 is configured. The operation control unit 202 can communicate with each of the operation mode input unit 208, the display device 118, the fuel cell 101, and the heat recovery device 102. For example, a signal indicating the operation mode input by the operation mode input unit 208 is input to the operation control unit 202. Further, the operation control unit 202 outputs a signal indicating information to be displayed on the display device 118 toward the display device 118.

  The cumulative activation number storage unit 206 stores the cumulative activation number of the fuel cell 101 up to the present time. The accumulated energization time storage unit 207 stores the accumulated energization time up to the present time of the fuel cell 101. The allowable startup number calculation unit 205 calculates the allowable startup number of the fuel cell 101 using the cumulative startup number obtained from the cumulative startup number storage unit 206 and the cumulative energization time obtained from the cumulative energization time storage unit 207. The activation protection determination unit 204 is based on the permitted number of activations of the fuel cell 101 obtained from the permitted number-of-activations calculation unit 205 and information indicating the operation state of the fuel cell 101 obtained through the operation control unit 202. It is determined whether is in the activation protection state. The operation plan calculation unit 203 creates an operation plan according to the determination result in the activation protection determination unit 204. The accumulated energization time is preferably counted after the fuel cell system 10 is set and delivered to the user, and is counted even when the fuel cell 101 is stopped while the power load or the hot water supply load is small. For example, the counting of the cumulative energization time may be started when an activation instruction is input through the operation panel 117.

  As shown in FIG. 3, from another viewpoint, the controller 116 includes a bus 300, a CPU 301, a RAM 302, a ROM 303, an interface 304, and an external storage device 305. The CPU 301, RAM 302, ROM 303, and interface 304 are connected to each other via a bus 300 so that they can communicate with each other. The external storage device 305 is connected to the interface 304, and the CPU 301 can read and write data with the external storage device 305 via the interface 304. For example, the ROM 303 stores a predetermined program. The above operations in the operation control unit 202, the operation plan calculation unit 203, the activation protection determination unit 204, and the allowable activation number calculation unit 205 are performed, for example, by the CPU 301 executing a predetermined program stored in the ROM 303. . As described above, the operations of the operation control unit 202, the operation plan calculation unit 203, the activation protection determination unit 204, and the allowable activation number calculation unit 205 are realized by, for example, cooperation between hardware and software. Each of the cumulative activation number storage unit 206 and the cumulative energization time storage unit 207 is configured by an external storage device 305, for example.

  As shown in FIG. 1, the fuel cell system 10 further includes a sensor 114. The sensor 114 detects a physical quantity for determining the exhaust heat recovery level. The sensor 114 is connected to the controller 116 by wire or wireless so that the detection signal of the sensor 114 is input to the controller 116. The sensor 114 detects the temperature of the water stored in the hot water storage tank 111, for example. For example, when the fuel cell system 10 is operating in the automatic operation mode, the controller 116 determines the exhaust heat recovery level based on information indicating the detection result of the sensor 114. In this case, the controller 116 determines that the fuel cell 101 is in the startup protection state when the exhaust heat recovery level is higher than the first level. On the other hand, the controller 116 determines that the fuel cell 101 is in the startup protection state when the exhaust heat recovery level is equal to or lower than the first level and the allowable startup count is less than a predetermined value.

  The exhaust heat recovery level is expressed, for example, as a percentage. When the exhaust heat recovery level is 100%, the heat recovery apparatus 102 stores an amount of heat corresponding to the upper limit value of the heat storage amount that can be stored. On the other hand, when the exhaust heat recovery level is 0%, the hot water storage tank 111 is filled with water at a reference temperature (for example, 20 ° C.) or less. The first level is 20%, for example.

  For example, when the fuel cell system 10 is operated in the manual operation mode and a start instruction is input to the operation panel 117, the controller 116 sets the exhaust heat recovery level based on information indicating the detection result of the sensor 114. decide. In this case, the controller 116 determines that the fuel cell 101 is in the startup protection state when the exhaust heat recovery level is higher than the second level. On the other hand, the controller 116 determines that the fuel cell 101 is in the startup protection state when the exhaust heat recovery level is equal to or lower than the second level and the allowable startup count is less than a predetermined value.

  For example, the second level is set higher than the first level. The second level is, for example, 80%. When an activation instruction is input to the operation panel 117 in the manual operation mode, it is desirable to activate the fuel cell 101 with priority given to the user's intention as much as possible. For this reason, the condition for determining that the fuel cell 101 is in the startup protection state in the manual operation mode is more relaxed than the condition for determining that the fuel cell 101 is in the startup protection state in the automatic operation mode. For example, in the case where a solar power generation device is provided, by generating power with the fuel cell system 10 during the daytime when the solar power generation is maximized, the power load consumed in the solar power generation is reduced. Electricity sales can be increased.

  When the controller 116 determines that the fuel cell 101 is in the startup protection state, the controller 116 outputs information indicating that the fuel cell 101 is in the startup protection state to at least one of the notification device 120 and the display device 118. Thereby, it is possible to notify the user that the fuel cell 101 is in the activation protection state.

  The controller 116 displays information including at least one of the allowable number of activations, the cumulative energization time from the start of energization of the fuel cell 101 to the present, and the cumulative number of activations of the fuel cell 101 up to the present with the alarm 120 and the display. At least one of the devices 118 may be output.

  With reference to FIGS. 4A, 4B, and 4C, an example of processing performed in the controller 116 to determine whether or not the fuel cell 101 is in the startup protection state will be described. The processing illustrated in FIGS. 4A, 4B, and 4C is triggered by a predetermined condition such as a user touching the operation panel 117, for example. This condition includes, for example, that an activation instruction is input to the operation panel 117 in the manual operation mode.

  As shown in FIG. 4A, in step S410, the controller 116 determines whether or not the fuel cell 101 is generating power. If the determination result in step S410 is affirmative, it is not necessary to determine whether or not the fuel cell 101 is in the startup protection state, and thus the process ends. When the determination result in step S410 is negative, the process proceeds to step S420, and the controller 116 determines whether or not the operation mode of the fuel cell system 10 is the automatic power generation mode. The automatic power generation mode includes, for example, an energy saving operation mode and a hot water storage power generation mode, and is automatically operated from the operation history of the fuel cell 101 and the heat recovery device 102 and the current operation state without specifying operation conditions by the user. This means a mode in which a plan is created and operated. The energy saving operation mode is realized by, for example, determining an operation plan that can reduce the energy used in the fuel cell system 10 as much as possible from loads such as an electric power load and a hot water supply load by learning control. The hot water storage power generation mode is a mode for, for example, increasing the amount of exhaust heat recovered by the heat recovery device as much as possible and storing hot water in the hot water storage tank 111 as much as possible.

  If the determination result in step S420 is affirmative, the process proceeds to step S421, and the controller 116 determines the exhaust heat recovery level LHR. Next, proceeding to step S422, the controller 116 determines whether or not the exhaust heat recovery level LHR is higher than the first level. When the determination result in step S422 is negative, the controller 116 proceeds to step S423, and acquires the number of times Ts of activation of the fuel cell 101 today. The number of activations Ts of the fuel cell 101 today is counted by, for example, a predetermined counter that is incremented every time the fuel cell 101 is activated, and the counting result of the counter is reset every day. For example, the controller 116 refers to the count result of the counter to obtain the activation count Ts.

Next, proceeding to step S424, the controller 116 determines the allowable number of activations Ta. The allowable number of activations Ta is, for example, a predetermined number of activations of the fuel cell 101 per unit time, an accumulated energization time from the start of energization of the fuel cell 101 to the present, and an accumulated number of activations of the fuel cell 101 to the present. Is determined based on the following relationship between: The unit time is, for example, one day. For example, the controller 116 reads the number of activations of the fuel cell 101 per unit time determined in advance from the ROM 303. In addition, the controller 116 reads, for example, the cumulative energization time from the start of energization of the fuel cell 101 to the present and the cumulative number of activations of the fuel cell 101 from the present from the external storage device 305.
Ta = (cumulative energization time to date ÷ 24 hours) × number of times fuel cell 101 is activated per day−accumulated number of times fuel cell 101 has been activated + number of initial marginal activation times

  For example, it is assumed that the service life of the fuel cell system 10 is 10 years and that the fuel cell system 10 has a service life of 4000 times. Further, according to the basic design of the fuel cell system 10, it is assumed that the predetermined number of activations of the fuel cell 101 per day is one. The initial margin activation number is determined as follows, for example. Assuming that the fuel cell system 10 is operated according to the basic design, the fuel cell 101 is activated once per day, which is determined in advance. Therefore, if the leap year is not taken into consideration, the fuel cell 101 at the service life of 10 years is considered. Is activated 3650 times. Since the fuel cell system 10 has a service life of 4000 times, the basic design has a margin of 350 times (= 4000 times-3650 times) with respect to the number of times the fuel cell 101 is started. For example, this value is set as the initial margin start-up count.

  For example, if the cumulative energization time to date is 1000 hours and the cumulative number of activations is 30, the allowable number of activations Ta is (1000 hours ÷ 24 hours) × 1−30 times + 350 times = 361. Determined once.

  When the allowable number of activations Ta is determined by the controller 116, the process proceeds to step S440. As shown in FIG. 4B, in step S440, the controller 116 determines whether or not the number of activations Ts for today is N or more. N is typically the number of activations of the fuel cell 101 per day (for example, once) predetermined in the basic design. N may be an integer greater than or equal to 2 in some cases. In this case, depending on conditions, it is allowed to start the fuel cell 101 a plurality of times a day. N may take a different value depending on, for example, the power generation mode. In the automatic operation mode, N is typically 1 from the viewpoint of energy saving, output performance, and durability while considering adapting to the lifestyle of the user. If N = 0, that is, if the fuel cell 101 continues to operate continuously, the stack voltage decreases in the fuel cell stack 105, and a desired output (for example, 700 W) cannot be maintained. On the other hand, when N = 1, the fuel cell 101 stops once a day, so that a decrease in output performance can be suppressed. In addition, when N = 1, it is possible to suppress the generation of an excessive amount of hot water while ensuring the amount of hot water consumed by the user per unit time (for example, one day), thereby improving energy saving. it can. On the other hand, in the manual power generation mode, N may be 2 or more. If the determination result in step S440 is affirmative, the controller 116 proceeds to step S441, determines that the fuel cell 101 is in the startup protection state, and causes the display device 118 to display information indicating that. As a result, a series of processing ends. The controller 116 may cause the notification device 120 to notify information indicating that the fuel cell 101 is in the startup protection state. In this case, the controller 116 may cause the display device 118 or the alarm device 120 to output information indicating the number of activations Ts of today.

  When the determination result in step S440 is negative, the process proceeds to step S442, and the controller 116 determines whether the activation allowable number Ta is less than a predetermined value. The predetermined value is, for example, once. If the determination result in step S442 is affirmative, the controller 116 proceeds to step S443, determines that the fuel cell 101 is in the startup protection state, and causes the display device 118 to display information indicating that. As a result, a series of processing ends. The controller 116 may cause the notification device 120 to notify information indicating that the fuel cell 101 is in the startup protection state. In this case, the controller 116 may cause the display device 118 or the alarm device 120 to output information indicating the allowable activation number Ta.

  If the determination result in step S442 is negative, the controller 116 proceeds to step S444, determines that the fuel cell 101 is in a startable state, and ends the series of processes. When information indicating that the fuel cell 101 is in the activation protection state is output to the display device 118 or the alarm device 120, the controller 116 stops outputting the information. The controller 116 may cause the display device 118 or the notification device 120 to output information indicating that the fuel cell 101 is in a startable state. In this case, the controller 116 may cause the display device 118 or the alarm device 120 to output information indicating the allowable activation number Ta.

  If the determination result in step S422 is affirmative, the controller 116 proceeds to step S450. As shown in FIG. 4C, in step S450, the controller 116 acquires the number of times Ts of activation of the fuel cell 101 today. Next, proceeding to step S451, the controller 116 determines whether or not the number of times Ts of activation of the fuel cell 101 today is N or more. If the determination result in step S451 is affirmative, the controller 116 proceeds to step S452, determines that the fuel cell 101 is in the startup protection state, and causes the display device 118 to display information indicating that. As a result, a series of processing ends. The controller 116 may cause the notification device 120 to notify information indicating that the fuel cell 101 is in the startup protection state. In this case, the controller 116 may cause the display device 118 or the alarm device 120 to output information indicating the number of activations Ts of today.

  If the determination result in step S451 is negative, the controller 116 proceeds to step S453, determines that the fuel cell 101 is in a startable state, and displays information indicating that the fuel cell 101 is in a start protection state. When the information is output to the device 118 or the alarm device 120, the output of the information is stopped. As a result, a series of processing ends. The controller 116 may cause the display device 118 or the notification device 120 to output information indicating that the fuel cell 101 is in a startable state. In this case, the controller 116 may cause the display device 118 or the alarm device 120 to output information indicating the allowable activation number Ta.

  If the exhaust heat recovery level LHR is higher than the first level, the amount of heat stored in the heat recovery device 102 is sufficient, and even if the fuel cell 101 is started, a large amount of exhaust heat cannot be recovered by the heat recovery device 102. Probability is high. In this case, when the fuel cell 101 is activated, the energy saving performance of the fuel cell system 101 may be sacrificed. Therefore, if the determination result in step S422 is affirmative, the process proceeds to step S450, and the controller 116 allows the fuel cell 101 to be activated only when the activation count Ts is less than N.

  If the determination result in step S420 is negative, the controller 116 proceeds to step S430, and the controller 116 determines whether or not the operation mode of the fuel cell system 10 is the manual power generation mode. If the determination result in step S430 is negative, the process proceeds to step S450. If the determination result in step S430 is affirmative, the process proceeds to step S431, and the controller 116 determines the exhaust heat recovery level LHR. Next, proceeding to step S432, the controller 116 determines whether or not the exhaust heat recovery level LHR is higher than the second level. If the determination result in step S432 is negative, the controller 116 proceeds to step S433, and acquires the number of times Ts of activation of the fuel cell 101 today. Next, proceeding to step S434, the controller 116 determines the allowable number of activations Ta, and proceeds to step S440. If the determination result in step S432 is affirmative, the controller 116 proceeds to step S450.

  If the determination result in step S422 is affirmative and the determination result in step S432 is affirmative, instead of proceeding to step S450, the controller 116 determines that the fuel cell 101 is in the startup protection state. The information indicating that may be displayed on the display device 118 and the series of processing may be terminated.

  According to the fuel cell system 10, the allowable startup number Ta is determined without using the service life. Therefore, if the fuel cell system 10 can be continuously operated by appropriate maintenance or replacement of parts even after the service life (for example, 10 years) has elapsed, the program stored in the ROM 303 of the controller 116 is updated. The fuel cell 101 can be started without As a result, the allowable number of activations of the fuel cell 101 can be fully utilized.

  According to the fuel cell system 10, the accumulated energization time is counted even when the power load or the hot water supply load is small and the fuel cell 101 is stopped. Therefore, the stop time of the fuel cell 101 is determined for the allowable number of activations Ta. Reflected appropriately. For this reason, when the number of start-ups of the fuel cell 101 is small, the possibility that the fuel cell system 10 can be continuously operated increases even if the service life (for example, 10 years) is exceeded.

  According to the fuel cell system 10, when the power load or the hot water supply load is large and it is advantageous from the viewpoint of energy saving to operate the fuel cell system 10 for more than 24 hours, the allowable number of activations Ta tends to increase. . Thus, even if the load is generated in various patterns such as when the load is small and when the load is large, the allowable number of activations of the fuel cell 101 can be fully utilized.

  The operation mode of the fuel cell system 10 includes various power generation modes such as an energy saving operation mode, a power generation main operation mode, a hot water storage power generation mode, a reserved power generation mode, and an immediate power generation mode. The energy saving operation mode is a mode for minimizing the primary energy consumption by comprehensively considering the power load and the hot water supply load. The power generation main operation mode is a mode mainly for power generation. The hot water storage power generation mode is a mode for the purpose of maximizing the heat storage amount. In the hot water storage power generation mode, in order to maximize the heat storage amount, it is also possible to increase the heat storage amount by not supplying the electric power load to the heater for heating the heat medium without supplying the power load. The reserved power generation mode is a mode for generating power at a time specified by the user. In the reserved power generation mode, N is typically 1. The immediate power generation mode is a mode in which power generation is started immediately in accordance with a user instruction. When such various operation modes are included in the operation mode of the fuel cell system 10, it is possible to satisfy various needs of users.

  According to the fuel cell system 10, for example, when the number of activations Ts today is N or more, the display device 118 displays that the fuel cell 101 is in the activation protection state. Further, when the operation mode of the fuel cell system 10 is an automatic power generation mode such as a hot water storage power generation mode, the exhaust heat recovery level is higher than the first level (for example, 20%), and the allowable startup number Ta is less than one, The display device 118 displays that the fuel cell 101 is in the startup protection state. Further, when the operation mode of the fuel cell system 10 is the manual power generation mode, the exhaust heat recovery level is higher than the second level (for example, 80%), and the allowable startup number Ta is less than 1, the fuel cell 101 is started. The display device 118 displays that it is in the protected state. When the user tries to start the fuel cell 101, the user can be warned by voice or a message that the fuel cell 101 is in the start-up protection state.

  In this way, by notifying the user that the fuel cell 101 is in the activation protection state, it is possible to suppress a decrease in the allowable number of activations of the fuel cell 101 due to a large number of activation instructions issued by the user during a predetermined period. Further, if the exhaust heat recovery level is relatively high, the fuel cell 101 may be in a start-up protection state, so that the user can be prompted to consume the hot water stored in the hot water storage tank 111. In a cogeneration system such as the fuel cell system 10, consumption of stored hot water often leads to energy saving.

  The technology disclosed in the present specification includes a predetermined number of start times of the fuel cell per unit time, a cumulative energization time from the start of energization of the fuel cell to the present, and a cumulative number of times of start of the fuel cell up to the present. Since the allowable number of activations is determined based on the relationship, it is possible to provide a fuel cell system that can be re-operated after inspection even when the service life has been reached. Further, according to the technology disclosed in the present specification, the fuel cell can be increased in the allowable number of times of activation with the “cumulative energization time” in the long-term stop state or the long-time power generation continuation state, and is suitable for the actual operation state Can be activated.

DESCRIPTION OF SYMBOLS 10 Fuel cell system 101 Fuel cell 102 Heat recovery apparatus 114 Sensor 116 Controller 117 Operation panel 118 Display apparatus 120 Alarm

Claims (6)

A fuel cell that generates electricity using an oxidant gas and a hydrogen-containing gas;
A controller for controlling the operation of the fuel cell,
The controller is
The allowable number of activations based on the relationship between the predetermined number of activations of the fuel cell per unit time, the cumulative energization time from the start of energization of the fuel cell to the present, and the cumulative number of activations of the fuel cell up to the present Decide
When the allowable number of activations is less than a predetermined value, it is determined that the fuel cell is in an activation protection state in which activation of the fuel cell should be prohibited,
Prohibiting startup of the fuel cell when it is determined that the fuel cell is in the startup protection state during the stop period of the fuel cell;
Fuel cell system. A heat recovery device for recovering and storing waste heat generated during power generation of the fuel cell;
An operation panel having at least one of a notification device and a display device,
The controller includes an automatic operation mode in which the fuel cell is operated according to an exhaust heat recovery level indicating a level of heat stored in the heat recovery device, and the fuel according to an instruction input to the operation panel. Operating the fuel cell and the heat recovery device according to any one of the manual operation modes in which the operation of the battery is started or stopped.
The fuel cell system according to claim 1. A sensor for detecting a physical quantity for determining the exhaust heat recovery level;
The controller is
When the fuel cell system is operated in the automatic operation mode, the exhaust heat recovery level is determined based on information indicating a detection result of the sensor,
When the exhaust heat recovery level is higher than the first level, the fuel cell is determined to be in the startup protection state;
When the exhaust heat recovery level is equal to or lower than the first level and the allowable number of activations is less than the predetermined value, the fuel cell is determined to be in the activation protection state;
The fuel cell system according to claim 2. A sensor for detecting a physical quantity for determining the exhaust heat recovery level;
The controller is
When the fuel cell system is operated in the manual operation mode and a start instruction is input to the operation panel, the exhaust heat recovery level is determined based on information indicating a detection result of the sensor,
When the exhaust heat recovery level is higher than a second level, the fuel cell is determined to be in the startup protection state;
When the exhaust heat recovery level is less than or equal to the second level and the allowable number of activations is less than the predetermined value, the fuel cell is determined to be in the activation protection state;
The fuel cell system according to claim 2.   When the controller determines that the fuel cell is in the startup protection state, the controller outputs information indicating that the fuel cell is in the startup protection state to at least one of the notification device and the display device. The fuel cell system according to any one of claims 2 to 4. A method for operating a fuel cell system, comprising:
The permissible number of activations is determined based on the relationship between the predetermined number of fuel cell activations per unit time, the cumulative energization time from the start of energization of the fuel cell to the present, and the cumulative number of activations of the fuel cell up to the present. Decide
When the allowable number of activations is less than a predetermined value, it is determined that the fuel cell is in an activation protection state in which activation of the fuel cell should be prohibited,
Prohibiting activation of the fuel cell when it is determined that the fuel cell is in the activation protection state during the stop period of the fuel cell;
Method.

Images