Fuel cell device, operation control method and program

Abstract

To accurately respond to users' desires and suppress a reduction in driving merits.SOLUTION: The present invention comprises a driving state determination unit 34 that determines continuation of driving under merit reduction suppression or reactivation for normal driving, on the basis of an average value and a set merit determination threshold, and a driving control unit 35 that executes control for continuation of driving under merit reduction suppression or reactivation for normal driving, on the basis of the determination result. The merit determination threshold is such that the threshold in initial driving state determination is highest after driving is stopped under merit reduction suppression, and the threshold decreases thereafter. The driving state determination unit 34 determines continuation of driving under merit reduction suppression or reactivation for normal driving at a predetermined timing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fuel cell device, an operation control method, and a program. [Background technology]

[0002] Recently, as a next-generation energy source, a fuel cell device that includes a fuel cell capable of generating electric power using hydrogen gas and an oxygen-containing gas, and auxiliary equipment for operating the fuel cell housed in an outer case, and an operating method thereof have been proposed.

[0003] Fuel cells are highly convenient as a system that directly converts chemical energy contained in fuel into electrical energy. Furthermore, fuel cells generate electricity directly through an electrochemical reaction between hydrogen, which serves as a fuel, and oxygen, which serves as an oxidant. This allows for highly efficient generation of electrical energy, while also offering the advantages of being quiet and not emitting harmful exhaust gases, making them an environmentally friendly system.

[0004] On the other hand, fuel cells are capable of power load following operation, which changes the power generation output depending on the magnitude of the power load. However, when the power load or heat load is very small, even when the fuel cell is operated at minimum output, surplus power and heat are generated in the fuel cell, and the operational benefits that would be obtained by operating the fuel cell (for example, reduction in primary energy consumption, reduction in energy costs, reduction in carbon dioxide emissions, etc.) are reduced. Therefore, when the power load or the heat load is very small, it is necessary to stop the operation of the fuel cell.

[0005] In response to the above-mentioned problems, a technology has been disclosed that prevents a decline in the benefits of operation by operating and stopping a solid oxide fuel cell at appropriate times.The technology includes a load measurement unit that measures the load energy required by the energy load unit, a load calculation unit that calculates an average calculated value of the load measurement values ​​of the load measurement unit measured over a specified judgment period, an operation judgment unit that determines whether to continue operation or stop operation based on either the average calculated value or an alternative value derived from the average calculated value and a judgment threshold value, a threshold setting unit that sets the judgment threshold value, and an operation control unit that issues an operation continuation command or an operation stop command to the solid oxide fuel cell based on the judgment result of the operation judgment unit (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-174750 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the technology described in Patent Document 1, the average calculated value of the household load measurement values ​​or a substitute value derived from the average calculated value is compared with a merit determination threshold once a month to determine whether to continue operating the fuel cell system or stop operation.Furthermore, since the determination threshold is fixed, once the fuel cell system is stopped, it will not operate for at least one month. This creates a problem in that the operating merits are actually lost, especially during periods when user load demands increase sharply, such as from autumn to winter.

[0008] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide a fuel cell device, an operation control method, and a program that accurately meets user needs and suppresses a decrease in operating benefits. [Means for solving the problem]

[0009] Form 1: One or more embodiments of the present invention propose a fuel cell device capable of performing merit reduction suppression, comprising: a load measurement unit that measures the amount of load energy required as an energy load; a load calculation unit that calculates the average value of the load measurement values ​​measured by the load measurement unit over a predetermined judgment period; a threshold setting unit that sets a merit determination threshold; an operating state determination unit that determines whether to continue operation during merit reduction suppression or restart to normal operation based on the average value and the merit determination threshold; and an operating control unit that executes control to continue operation during merit reduction suppression or restart to normal operation based on the judgment result of the operating state determination unit, wherein the merit determination threshold is the highest for the first operating state determination after operation is stopped during merit reduction suppression, and the threshold decreases thereafter, and the operating state determination unit determines whether to continue operation during merit reduction suppression or restart to normal operation at a predetermined timing.

[0010] Form 2: One or more embodiments of the present invention propose a fuel cell device characterized in that the merit determination threshold has a period of time during which it decreases at a predetermined slope from the threshold for the initial operating state determination after operation is stopped during the merit reduction suppression.

[0011] Form 3: One or more embodiments of the present invention propose a fuel cell device characterized in that the merit determination threshold becomes a constant value after a period of time has passed in which the merit determination threshold decreases at a predetermined slope from the threshold for the initial operating state determination after operation is stopped to suppress the merit reduction.

[0012] Mode 4: One or more embodiments of the present invention are an operation control method for a fuel cell device that includes a load measurement unit, a load calculation unit, a threshold setting unit, an operation state determination unit, and an operation control unit, and that can perform merit operation reduction suppression, the method including a first step in which the load measurement unit measures a load energy amount required as an energy load, a second step in which the load calculation unit calculates an average value of load measurement values ​​measured by the load measurement unit over a predetermined determination period, a third step in which the threshold setting unit sets a merit determination threshold, and a third step in which the operation state determination unit performs merit reduction suppression based on the average value and the merit determination threshold. The proposed operation control method comprises a fourth step of determining whether to continue operation under merit reduction suppression or restart to normal operation, and a fifth step in which the operation control unit executes control to continue operation under merit reduction suppression or restart to normal operation based on the determination result in the fourth step, wherein the merit determination threshold set in the third step is the highest threshold for the first operating state determination after operation is stopped under merit reduction suppression, and the threshold decreases thereafter, and a determination is made in the fourth step to continue operation under merit reduction suppression or stop operation at a predetermined timing.

[0013] Form 5: One or more embodiments of the present invention propose an operation control method characterized in that the merit determination threshold set in the third step has a period of time during which it decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped in the merit reduction suppression.

[0014] Mode 6: One or more embodiments of the present invention propose an operational control method characterized in that the merit determination threshold set in the third step becomes a constant value after a period of time has passed during which the merit determination threshold decreases at a predetermined slope from the threshold in the initial operational state determination after operation is stopped in the merit reduction suppression.

[0015] Mode 7: One or more embodiments of the present invention are a program for causing a computer to execute an operation control method for a fuel cell device that includes a load measurement unit, a load calculation unit, a threshold setting unit, an operating state determination unit, and an operation control unit, and that is capable of suppressing a merit operation degradation, the program including a first step in which the load measurement unit measures a load energy amount required as an energy load, a second step in which the load calculation unit calculates an average value of load measurement values ​​measured by the load measurement unit over a predetermined determination target period, a third step in which the threshold setting unit sets a merit determination threshold, and a third step in which the operating state determination unit calculates a merit determination value based on the average value and the merit determination threshold. Based on this, we propose a program that includes a fourth step of determining whether to continue operation while suppressing merit reduction or to restart to normal operation, and a fifth step in which the operation control unit executes control to continue operation while suppressing merit reduction or to restart to normal operation based on the determination result in the fourth step, wherein the merit determination threshold set in the third step is the highest threshold for the first operating state determination after operation is stopped while suppressing merit reduction, and the threshold decreases thereafter, and in the fourth step, a determination is made at a predetermined timing to continue operation while suppressing merit reduction or to stop operation.

[0016] Form 8: One or more embodiments of the present invention propose a program characterized in that the merit determination threshold set in the third step has a period of time during which it decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped in the merit reduction suppression.

[0017] Form 9: One or more embodiments of the present invention propose a program characterized in that the merit determination threshold set in the third step becomes a constant value after a period of time has passed in which the merit determination threshold decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped in the merit reduction suppression. [Effects of the Invention]

[0018] According to one or more embodiments of the present invention, it is possible to accurately meet the needs of users and to suppress a decrease in driving benefits. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing the configuration of a fuel cell device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram illustrating a configuration of a control unit according to the present embodiment. [Figure 3] FIG. 10 is a diagram showing the transition of the merit determination threshold when there is a merit according to the present embodiment. [Figure 4] FIG. 4 is a diagram illustrating processing by a control unit according to the present embodiment. [Figure 5] FIG. 4 is a diagram illustrating processing by a control unit according to the present embodiment. [Figure 6] FIG. 4 is a diagram illustrating processing by a control unit according to the present embodiment. [Figure 7] FIG. 4 is a diagram illustrating processing by a control unit according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] <Embodiment> A fuel cell device 1 according to this embodiment will be described with reference to FIGS.

[0021] <Configuration of fuel cell device 1> As shown in Figure 1, the fuel cell device 1 is composed of a fuel cell module 11, a hot water storage tank 12, a power load section 13, a heat load section 14, a hot water supply path 15, an exhaust heat recovery path 16, an exhaust heat recovery pump 17, a radiator 18, an auxiliary heat source section 21, an inverter 22, a commercial power source 25, and a control unit 30.

[0022] The fuel cell module 11 is configured by housing a cell stack and a reformer inside a box-shaped housing container. The fuel cell module 11 has a stack structure in which a plurality of fuel cell units are stacked one on top of the other. The fuel cell may be of any known type, such as a flat plate type, a hollow flat plate type, a cylindrical type, a horizontal stripe type, etc. The fuel cell stack is configured, for example, by arranging hollow flat plate type fuel cells, each having a fuel gas flow path (not shown) through which fuel gas flows in the longitudinal direction (vertical direction during operation), in a line in an upright position, with adjacent fuel cells being electrically connected in series via current collecting members.

[0023] The hot water storage tank 12 stores the hot water generated in the heat exchanger 19. A circulation pipe including the hot water storage tank 210 and the exhaust heat recovery path 16 described later is provided, and the temperature of the hot water stored in the hot water storage tank 12 is controlled by circulating the hot water through the circulation pipe.

[0024] The power load section 13, together with the heat load section 14, constitutes an energy load. Electrical energy generated by the operation of the fuel cell module 11 is supplied to a power load section 13, and thermal energy generated by the operation of the fuel cell module 11 is supplied to a thermal load section . The power load unit 13 can also consume power supplied from a commercial power source 25, and the heat load unit 14 can also consume heat supplied from an auxiliary heat source unit 21 that generates heat by burning fuel, for example.

[0025] The exhaust heat recovery pump 17 causes hot and cold water to flow in the exhaust heat recovery path 16 . The operation of the exhaust heat recovery pump 17 is controlled by the control unit 30. For example, the control unit 30 operates the exhaust heat recovery pump 17 to generate hot water, causing the relatively low-temperature hot water stored in the lower part of the hot water storage tank 12 to flow into the exhaust heat recovery path 16.

[0026] The radiator 18 is provided in the exhaust heat recovery path 16 and radiates heat from the hot water that flows through the exhaust heat recovery path 16 from the hot water storage tank 12 to the heat exchanger 19 . The control unit 30 stops the operation of the radiator 18 when the temperature of the hot water flowing from the hot water storage tank 12 to the heat exchanger 19 is lower than a set upper limit temperature. On the other hand, when the temperature of the hot water flowing from the hot water storage tank 12 to the heat exchanger 19 is equal to or higher than the set upper limit temperature, the control unit 30 operates the radiator 18 to radiate heat, thereby lowering the temperature of the hot water.

[0027] The inverter 22 converts DC power, which is the power generated by the fuel cell module 11, into AC power. The inverter 22 is electrically connected to the received power supply line L2 via the generated power supply line L1, and the generated power from the fuel cell module 11 is supplied to the power load section 13 via the inverter 22, the generated power supply line L1, and the received power supply line L2.

[0028] The control unit 30 controls the overall operation of the fuel cell device 1 according to a control program stored in a ROM (Read Only Memory) or the like (not shown). The control unit 30 executes normal operation control as well as control related to suppression of merit reduction. Here, "suppressing reduction in benefits" means determining whether there is a benefit to operating the fuel cell device 1 and controlling whether to operate or stop the fuel cell device 1 in a situation where the balance between the consumption of fuel gas and water and the amount of power generated is disrupted when there is little electricity demand from users, and it is more advantageous from the perspective of running costs, etc. to stop the operation of the fuel cell device 1 than to operate it normally. In this embodiment, the control unit 30 sets a merit determination threshold, and determines whether to continue operation while suppressing merit decline or to restart to normal operation based on the average value of power demand and the merit determination threshold, and based on the determination result, executes control to continue operation while suppressing merit decline or to restart to normal operation. Here, the "merit determination threshold" is a threshold for determining whether to continue operation or restart to normal operation while suppressing merit reduction.

[0029] <Configuration of control unit 30> As shown in FIG. 2, the control unit 30 according to this embodiment includes a load measurement unit 31, a load calculation unit 32, a threshold setting unit 33, an operating state determination unit 34, and an operating control unit 35.

[0030] The load measuring unit 31 measures the amount of load energy required as an energy load. The load measurement unit 31 measures the load energy required as the energy load (electrical power load and thermal load) at a predetermined sampling interval (e.g., one to several hours) over a predetermined judgment period (e.g., 14 days), and repeats the measurement process to obtain the load measurement value.

[0031] The load calculation unit 32 calculates a moving average value of the load measurement values ​​measured by the load measurement unit 31 over a predetermined determination period. Although a moving average value is exemplified, it may be an arithmetic average value, a weighted average value, a median value, a mode value, or the like, which is a value that represents a group of load measurement values ​​over a predetermined period.

[0032] The threshold setting unit 33 sets a merit determination threshold. The merit determination threshold is set so that the threshold for the first operating state determination after operation is stopped in suppression of merit reduction is the highest, and the threshold thereafter decreases. Furthermore, the merit determination threshold has a period in which it decreases at a predetermined slope from the threshold used in the initial operating state determination after operation is stopped in the merit reduction suppression. Furthermore, the merit determination threshold value becomes a constant value after a period of time has passed during which the merit determination threshold value decreases at a predetermined slope from the threshold value used in the initial operating state determination after the operation is stopped in the merit reduction suppression.

[0033] The operating state determination unit 34 determines whether to continue operation while suppressing merit decline or to restart normal operation based on the moving average value and the merit determination threshold. Specifically, the merit determination thresholds include a stop threshold for determining whether to continue operation during normal operation, and a restart threshold for determining whether to restart normal operation when operation is stopped. The operating state determination unit 34 determines whether to stop operation from normal operation (transition to suppression of merit reduction) based on the moving average value of the load measurement value and the merit determination threshold set in the threshold setting unit 33, for example, when the moving average value falls below the stop threshold, as shown in Figure 3. After the operating state determination unit 34 determines whether to stop operation from normal operation, when the moving average value exceeds the restart threshold set by the threshold setting unit 33, it determines whether to restart operation to normal operation. The timing of the determination can be, for example, every 24 hours. The restart threshold value becomes a constant value after a predetermined period of time has elapsed, and this constant value is set to a value higher than the stop threshold value.

[0034] The operation control unit 35 executes control to continue operation while suppressing merit reduction or restart to normal operation based on the determination result of the operation state determination unit 34.

[0035] <Process 1 of the control unit 30> The flow up to the measurement process of the moving average value in the control unit 30 according to this embodiment will be described with reference to FIG.

[0036] First, the control unit 30 determines whether or not the fuel cell device 1 has entered the normal operation mode in response to a user's remote control operation (step S110). If the control unit 30 determines that the fuel cell device 1 has not been put into the normal operation mode by the user's remote control operation ("NO" in step S110), the process ends.

[0037] On the other hand, if the control unit 30 determines that the fuel cell device 1 has entered normal operation mode due to the user's remote control operation ("YES" in step S110), the control unit 30 determines whether a predetermined power demand calculation period (e.g., 24 hours) has elapsed (step S120). If the control unit 30 determines that the predetermined power demand calculation period has not elapsed ("NO" in step S120), the control unit 30 ends the process.

[0038] Furthermore, when the control unit 30 determines that the predetermined power demand calculation period has elapsed ("YES" in step S120), it causes the load measurement unit 31 to execute a process for calculating the power demand (step S130). The power demand measured by the load measuring unit 31 is then sent to the load calculating unit 32 .

[0039] Next, the control unit 30 causes the load calculation section 32 to execute a process of calculating the average power demand (moving average value) (step S140). The average power demand calculated by the load calculation unit 32 is then sent to the operating state determination unit 34.

[0040] The control unit 30 determines whether the determination period has elapsed in the load calculation section 32 (step S150). Then, when the load calculation section 32 determines that the determination period has not elapsed ("NO" in step S150), the control unit 30 ends the process and starts the process again.

[0041] On the other hand, if the load calculation unit 32 determines that the determination period has elapsed ("YES" in step S150), the control unit 30 shifts the processing to the merit reduction suppression determination processing by the operating state determination unit 34 and ends the processing.

[0042] <Process 2 in Control Unit 30> The flow up to the process of setting the merit determination threshold in the control unit 30 according to this embodiment will be described with reference to FIG.

[0043] The control unit 30 determines whether or not the fuel cell device 1 has stopped operation due to suppression of merit reduction (step S210). If the control unit 30 determines that the fuel cell device 1 has not stopped operation due to suppression of merit reduction ("NO" in step S210), it sets the merit determination threshold to an initial value (step S220) and ends the process.

[0044] On the other hand, when the control unit 30 determines that the fuel cell device 1 has stopped operation due to suppression of merit decline ("YES" in step S210), it executes a timing process (step S230). The timing process measures the time until the next determination of suppression of merit decline (determination timing).

[0045] The control unit 30 determines whether a predetermined time has elapsed in the timing process (step S240). In this embodiment, a determination is made every 24 hours as to whether to continue operation or restart to normal operation, and therefore, it is determined whether 24 hours have passed since the operation was stopped. Then, when the control unit 30 determines in the timing process that the predetermined time has not elapsed ("NO" in step S240), it continues the timing process.

[0046] The control unit 30 executes a merit determination threshold subtraction process such that the merit determination threshold decreases with time at a predetermined gradient with respect to the initial value of the merit determination threshold (step S250).

[0047] Next, the control unit 30 receives the result of the merit determination threshold subtraction process and executes a merit determination threshold setting process for setting the process result to the merit determination threshold at a predetermined determination timing (step S260). Then, the timer is initialized (step S270).

[0048] Then, the control unit 30 compares the merit determination threshold set in the merit determination threshold setting calculation process with the predetermined lower limit value of the merit determination threshold, and determines whether the merit determination threshold obtained in the merit determination threshold calculation process is equal to or greater than the predetermined lower limit value of the merit determination threshold (step S280). At this time, if the control unit 30 determines that the merit determination threshold obtained in the merit determination threshold calculation process is equal to or greater than the predetermined lower limit value of the merit determination threshold ("YES" in step S280), the process ends.

[0049] On the other hand, if the control unit 30 determines that the merit determination threshold obtained in the merit determination threshold calculation process is not equal to or greater than the predetermined lower limit value of the merit determination threshold ("NO" in step S280), it sets the merit determination threshold obtained in the merit determination threshold calculation process as the lower limit value (step S280) and terminates the processing.

[0050] When the process is completed, the merit determination threshold set in any one of steps S220, S260, and S290 is stored, and the process is restarted.

[0051] <Process 3 in Control Unit 30> The merit reduction suppression process in the control unit 30 according to this embodiment will be described with reference to FIGS.

[0052] The control unit 30 determines whether the merit determination threshold is greater than the average power demand (step S310). Then, when the control unit 30 determines that the merit determination threshold is greater than the average power demand ("YES" in step S310), the control unit 30 transitions the process to step S320.

[0053] The control unit 30 determines whether the fuel cell device 1 is in operation (step S320). If the control unit 30 determines that the fuel cell device 1 is not in operation ("NO" in step S320), the process returns to step S310.

[0054] On the other hand, when the control unit 30 determines that the fuel cell device 1 is in operation ("YES" in step S320), it notifies the user that the operation of the fuel cell device 1 will be stopped (step S330).

[0055] Next, the control unit 30 determines whether or not there has been an input from the user to disallow the stop of normal operation accompanying the transition to merit operation (step S340). If the control unit 30 determines that there has been an input from the user disallowing the stop of normal operation associated with the transition to merit operation ("YES" in step S340), it performs processing to continue normal operation without executing the stop of normal operation associated with the transition to merit operation (step S350), and terminates the processing.

[0056] On the other hand, if the control unit 30 determines that there has been no input from the user to disallow the suspension of normal operation due to the transition to merit operation ("NO" in step S340), it determines whether a predetermined timing has elapsed (step S380). If the control unit 30 determines that the predetermined timing has not elapsed ("NO" in step S380), it continues the determination in step S380.

[0057] On the other hand, if the control unit 30 determines that the predetermined timing has elapsed ("YES" in step S380), it executes processing to stop operation of the fuel cell device 1 by suppressing merit reduction (step S390), and ends the processing.

[0058] Furthermore, if the control unit 30 determines in step S310 that the merit determination threshold is smaller than the average demand power ("NO" in step S310), it determines whether the current state of the fuel cell device 1 is a shutdown state due to suppression of merit reduction (step S360).

[0059] If the control unit 30 determines that the operation of the fuel cell device 1 is not stopped due to suppression of merit reduction ("NO" in step S360), the control unit 30 ends the process. On the other hand, if the control unit 30 determines that the operation of the fuel cell device 1 has been stopped due to merit reduction suppression ("YES" in step S360), it performs a process to restart the fuel cell device 1 from its current stopped state due to merit reduction suppression (step S370) and then terminates.

[0060] <Actions and Effects> As explained above, the fuel cell device 1 according to this embodiment is equipped with an operating state determination unit 34 that determines whether to continue operation or restart to normal operation when merit reduction is suppressed based on the moving average value of the control unit 30 and the merit determination threshold, and an operating control unit 35 that executes control to continue operation or restart to normal operation when merit reduction is suppressed based on the determination result of the operating state determination unit. The merit determination threshold is highest for the first operating state determination after operation is stopped when merit reduction is suppressed, and the threshold decreases thereafter, and the operating state determination unit 34 determines whether to continue operation or restart to normal operation when merit reduction is suppressed at a predetermined timing. In other words, the benefit determination threshold is set to be the highest for the first operating state determination after operation is stopped to suppress benefit reduction, and the threshold decreases thereafter, allowing for a flexible response to sudden increases in electricity demand. Therefore, it is possible to accurately respond to the user's requests and prevent a decrease in the driving benefits. In addition, the load calculation section 32 of the control unit 30 in the fuel cell device 1 according to this embodiment calculates a moving average value of the load measurement values ​​measured by the load measurement section 31 over a predetermined target period of determination. By optimizing this predetermined target period of determination, it is possible to accurately respond to the user's requests and prevent a decrease in the operating benefits.

[0061] Furthermore, the merit determination threshold of the control unit 30 in the fuel cell device 1 according to this embodiment has a period in which it decreases at a predetermined gradient from the threshold for the initial operating state determination after operation is stopped to suppress merit decline. In other words, when transitioning to merit reduction suppression, there is a period during which the merit determination threshold decreases at a predetermined slope from the threshold at the initial operating state determination after operation is stopped during merit reduction suppression, i.e., a period during which the merit determination threshold decreases in proportion to the elapsed time after transitioning to merit reduction suppression. In other words, after shifting to merit reduction suppression, the hurdle for switching from merit reduction suppression to normal operation becomes lower as time passes. Therefore, even if the demand for electricity increases due to various factors, it is possible to flexibly respond to the user's requests.

[0062] In addition, the merit determination threshold of the control unit 30 in the fuel cell device 1 according to this embodiment becomes a constant value that is higher than the predetermined threshold for determining the stoppage of operation during normal operation after a period of time during which the threshold decreases at a predetermined slope from the threshold for the initial operating state determination after the operation is stopped to suppress the merit decrease. In other words, if a considerable amount of time has passed since the transition to merit reduction suppression, the merit determination threshold is set to be able to balance the user's desire to enjoy the benefits of merit reduction suppression with the user's desire to be able to respond flexibly to sudden increases in electricity demand. Therefore, it is possible to accurately respond to the user's requests and prevent a decrease in the driving benefits.

[0063] <Variation 1> In this embodiment, the load energy required as the energy load is used as a predetermined judgment period of 14 days, but the period may be set flexibly by taking into account parameters such as seasonal and regional differences. By doing so, it is possible to accurately respond to the user's requests and prevent a decrease in the driving benefits.

[0064] <Variation 2> In this embodiment, the merit determination threshold is illustrated as decreasing at a predetermined slope from the value at the time of the initial operation shutdown judgment in suppressing merit decline, but the slope of the merit determination threshold may be set flexibly by taking into account parameters such as seasonal and regional differences. By doing so, it is possible to accurately respond to the user's requests and prevent a decrease in the driving benefits.

[0065] <Variation 3> In this embodiment, the judgment timing of the operating state judgment unit 34 is exemplified as 24 hours, but if the trend in power demand turns upward and is fluctuating between values ​​close to the merit judgment threshold, the judgment timing may be changed to a shorter interval. By doing so, it is possible to accurately respond to the user's requests and prevent a decrease in the driving benefits.

[0066] The fuel cell device 1 of the present invention can be realized by recording the processing of the control unit 30, etc. on a recording medium that can be read by a computer system, and having the control unit 30, etc. read and execute the program recorded on this recording medium. The computer system here includes hardware such as an OS and peripheral devices.

[0067] Furthermore, if a WWW (World Wide Web) system is used, the "computer system" also includes the homepage providing environment (or display environment). The program may also be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

[0068] The program may also be a program for implementing some of the above-mentioned functions, or may be a so-called differential file (differential program) that can implement the above-mentioned functions in combination with a program already stored in the computer system.

[0069] The above describes in detail an embodiment of the present invention with reference to the drawings, but the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention. [Explanation of symbols]

[0070] 1;Fuel cell device 11; Fuel cell module 12. Hot water tank 13;Power load section 14;Heat load section 15;Hot water supply channel 16: Exhaust heat recovery channel 17: Exhaust heat recovery pump 18; Heat sink 21;Auxiliary heat source section 22; Inverter 25;Commercial power supply 30;Control unit 31: Load measurement section 32;Load calculation section 33: Threshold setting unit 34: Driving state determination unit 35: Operation control unit

Claims

1. A fuel cell device capable of suppressing merit reduction, a load measuring unit that measures an amount of load energy required as an energy load; a load calculation unit that calculates an average value of the load measurement values ​​measured by the load measurement unit over a predetermined determination period; a threshold setting unit that sets a merit determination threshold; an operating state determination unit that determines whether to continue operation while suppressing merit reduction or to restart normal operation based on the average value and a merit determination threshold; an operation control unit that executes control of continuing operation or restarting to normal operation in the suppression of merit reduction based on a determination result of the operation state determination unit; Equipped with The fuel cell device is characterized in that the benefit determination threshold is the highest threshold for the first operating state determination after operation is stopped during the benefit reduction suppression, and the threshold decreases thereafter, and the operating state determination unit determines at a predetermined timing whether to continue operation during the benefit reduction suppression or restart to normal operation.

2. 2. The fuel cell device according to claim 1, wherein the merit determination threshold has a period during which it decreases at a predetermined gradient from the threshold for the initial operating state determination after operation is stopped during the merit reduction suppression.

3. 3. The fuel cell device according to claim 2, wherein the merit determination threshold becomes a constant value after a period of time has passed during which the merit determination threshold decreases at a predetermined gradient from the threshold used in the initial operating state determination after operation is stopped during the merit reduction suppression.

4. An operation control method for a fuel cell device that is equipped with a load measurement unit, a load calculation unit, a threshold setting unit, an operation state determination unit, and an operation control unit, and is capable of suppressing a decrease in merit operation, comprising: a first step in which the load measuring unit measures an amount of load energy required as an energy load; a second step in which the load calculation unit calculates an average value of the load measurement values ​​measured by the load measurement unit over a predetermined determination period; a third step in which the threshold setting unit sets a merit determination threshold; a fourth step in which the operating state determination unit determines whether to continue operation while suppressing merit reduction or to restart normal operation based on the average value and a merit determination threshold; A fifth step in which the operation control unit executes control to continue operation in the suppression of merit reduction or restart to normal operation based on the determination result in the fourth step; Equipped with The merit determination threshold set in the third step is the highest threshold for the first operating state determination after operation is stopped during merit reduction suppression, and the threshold decreases thereafter, and in the fourth step, a determination is made at a predetermined timing to continue operation or stop operation during merit reduction suppression.

5. The operation control method according to claim 4, characterized in that the merit determination threshold set in the third step has a period in which it decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped in the merit reduction suppression.

6. The operation control method according to claim 5, characterized in that the merit determination threshold set in the third step becomes a constant value after a period of time has passed in which the merit determination threshold decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped in the merit reduction suppression.

7. A program for causing a computer to execute an operation control method for a fuel cell device that includes a load measurement unit, a load calculation unit, a threshold setting unit, an operation state determination unit, and an operation control unit, and that is capable of suppressing a decline in merit operation, a first step in which the load measuring unit measures an amount of load energy required as an energy load; a second step in which the load calculation unit calculates an average value of the load measurement values ​​measured by the load measurement unit over a predetermined determination period; a third step in which the threshold setting unit sets a merit determination threshold; a fourth step in which the operating state determination unit determines whether to continue operation while suppressing merit reduction or to restart normal operation based on the average value and a merit determination threshold; A fifth step in which the operation control unit executes control to continue operation in the suppression of merit reduction or restart to normal operation based on the determination result in the fourth step; Equipped with The merit determination threshold set in the third step is the highest threshold for the first operating state determination after operation is stopped during merit reduction suppression, and the threshold decreases thereafter, and in the fourth step, a program is characterized in that it determines whether operation should continue or be stopped during merit reduction suppression at a predetermined timing.

8. The program according to claim 7, characterized in that the merit determination threshold set in the third step has a period in which it decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped in the merit reduction suppression.

9. The program described in claim 8, characterized in that the merit determination threshold set in the third step becomes a constant value after a period of time has passed in which the merit determination threshold decreases at a predetermined slope from the threshold in the initial operating state determination after operation is stopped during the merit reduction suppression.

Images