JP6656040B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system that supplies energy generated from a solid oxide fuel cell that can selectively control operation continuation and operation stop to an energy load unit.

  Fuel cells, especially solid oxides, are highly efficient but have poor start-stop resistance and are suitable for continuous operation. Of course, in the fuel cell, the power load following operation in which the generated power is changed according to the magnitude of the power load of the power load unit is possible, but when the power load is very small or the heat load is very small. In some cases, even if the fuel cell is operated at the lowest output, the power and heat generated by the fuel cell remain, so the operating benefits that would have been obtained by operating the fuel cell (for example, the amount of primary energy consumption, Energy cost reduction, emission carbon dioxide reduction, etc.). Therefore, when the power load is very small or the heat load is very small, it is required to stop the operation of the fuel cell.

  For example, Patent Literature 1, which describes a fuel cell system including a solid oxide fuel cell, automatically supplies power when a power supply from the solid oxide fuel cell to a load continues for a certain period of time or less. When the power supply from the system power to the load continues for a certain time or more, the start operation of the solid oxide fuel cell is automatically performed when the power supply from the system power to the load continues for a certain time or more. Control is disclosed. Further, a DSS operation (daily start / stop operation) in which power generation is stopped at night and power generation is stopped in the morning to start the operation in the morning is also disclosed.

JP 2011-198768 A

  However, a solid oxide fuel cell has a very high operating temperature and takes a long time to start and stop as compared with a polymer electrolyte fuel cell. Therefore, there is a problem in performing the DSS operation substantially. Furthermore, since the temperature of the member fluctuates up and down from a high temperature state during operation to a normal temperature during stoppage, if such start-up and stop-up are repeated, the durability of the part is affected by the change in stress applied to the part. Reliability may be reduced.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solid oxide fuel cell at an appropriate timing while avoiding frequent start and stop of the solid oxide fuel cell. An object of the present invention is to provide a fuel cell system in which a decrease in operating merits (for example, energy saving, energy saving, and carbon saving) is suppressed by performing operation and shutdown.

A fuel cell system according to the present invention for achieving the above object is a fuel cell system that supplies energy generated from a solid oxide fuel cell capable of selectively controlling operation continuation and operation stop to an energy load unit, A load measuring unit for measuring a load energy required by the energy load unit, and a load calculating unit for calculating an average calculated value of the load measured values of the load measuring unit measured over one month as a predetermined determination target period And, based on either the average calculated value or the alternative value derived from the average calculated value and the determination threshold, at the timing of monthly operation determination, continue operating the solid oxide fuel cell or An operation determining unit that determines operation stop; a threshold setting unit that sets the determination threshold; and the solid oxide based on a determination result of the operation determining unit. And a driving control section that gives an operation continuation instruction or the operation stop instruction to the fuel cell.

  In this configuration, the determination whether to continue the operation or stop the operation of the solid oxide fuel cell is based on the average calculation value calculated from the load measurement values acquired in the predetermined determination target period, or the average calculation value. The evaluation is performed by comparing a substitute value derived from the value, which is a substitute value of the average operation value, with a judgment threshold value set in advance by the threshold value setting unit. When the result of the determination that the operation is to be continued is output, an operation continuation command is given to the operation control unit, and the operation of the solid oxide fuel cell is continued. When the determination result of the operation stop is output, the operation stop command is given to the operation control unit, and the operation of the solid oxide fuel cell is stopped. Note that the average operation value here includes an arithmetic average value, a moving average value, a weighted average value, an intermediate value, a mode value, and the like, and the arithmetic average value is usually used.

  Since the average calculated value of the load in the predetermined determination target period is used, the increase or decrease in the load due to a sudden event is flattened, so that a robust determination result is obtained. The judgment threshold value used in the judgment is determined by the average operation value of the past sequential load measurement group and the operation resulting from the operation of the solid oxide fuel cell at the time when the average operation value is obtained. It can be obtained by statistically processing the relationship between the merit (for example, energy saving, energy saving, and carbon dioxide saving) and the actual value. Instead of using the average calculated value as it is for the determination, an alternative value obtained by converting the average calculated value into a numerical value that allows a clearer determination may be used.

  In the determination by the driving unit determination unit, since the driving merit is the basis of the determination, it is preferable to convert the average calculated value of the load into a numerical value (alternative value) representing the driving merit. For this purpose, the substitute value is a function value of an operation merit function for deriving the operation merit of the solid oxide fuel cell from the average operation value, and the threshold value setting unit is converted to the operation merit. It can be configured to set the determined threshold value, that is, the merit determination threshold value. Such a driving merit function allocates a group of average calculated values of loads generated during a predetermined determination target period as a first variable, and assigns an actual value of driving merit corresponding to each average calculated value as a second variable, The determination can be made based on the correlation between the first variable and the second variable. The driving merit function does not have to be a function in the mathematical sense, but a matrix such as a lookup table filled with interpolation processing between each averaged operation value and the corresponding driving merit actual value. It may be something. As a result, the substitute value becomes a value embodying the driving merit, and the driving determination using this substitute value produces a determination result in consideration of the driving merit.

  The amount used as the operating advantage of the solid oxide fuel cell is the amount of primary energy consumption or energy cost reduction or emission carbon dioxide reduction or the combination of these that can be obtained by operating the solid oxide fuel cell. Amount. The primary energy consumption reduction is the amount of primary energy consumption that can be reduced by operating the solid oxide fuel cell, and the amount of energy consumption when the solid oxide fuel cell is not operated to supply load energy to the load unit. It is obtained by subtracting the amount of primary energy consumed when the solid oxide fuel cell is operated to supply load energy to the load unit from the amount of primary energy consumed. Energy cost reduction is the energy cost that can be reduced by operating a solid oxide fuel cell.Similar to the primary energy consumption reduction, the solid oxide fuel cell is used to supply load energy to the load. It is obtained by subtracting the energy cost when the solid oxide fuel cell is operated to supply load energy to the load unit from the energy cost when the solid oxide fuel cell is not operated. The amount of carbon dioxide emission reduction is the amount of carbon dioxide emissions that can be reduced by operating the solid oxide fuel cell, and the amount of carbon dioxide when the solid oxide fuel cell is not operated to supply load energy to the load section It is obtained by subtracting the amount of carbon dioxide emitted when the solid oxide fuel cell is operated to supply load energy to the load unit from the amount of carbon dioxide emitted. Therefore, operating costs of the solid oxide fuel cell are considered as cost or environmental considerations by treating any of primary energy consumption reduction, energy cost reduction, emission carbon dioxide reduction, or a combination thereof. Proper operation of the solid oxide fuel cell is realized.

  The average calculated value in the predetermined determination target period may be substantially the same even if the variation (variance) of the load measurement value that is the basis is significantly different. That is, when determining whether to continue or stop the operation based on the average calculated value of the load or the substitute value calculated based on the average calculated value, it is not possible to consider the variation in the measured load value in the determination target period. To solve this problem, the load calculation unit calculates a standard deviation in the determination target period based on a load measurement value included in each section obtained by dividing the determination target period, and calculates the standard deviation from the average calculation value. A first value that is a function value derived from the driving merit function using the lower value obtained by subtracting the standard deviation, and a first value that is derived from the driving merit function using an upper value obtained by adding the standard deviation to the alternative value. A value between the function value and the second value is calculated as an evaluation merit value, and the operation determination unit operates the solid oxide fuel cell based on the evaluation merit value and the merit determination threshold. It can be configured to determine continuation or shutdown. In other words, the lower limit of the alternative value range corresponding to the densely distributed average calculated value is set as the substitute value of the value obtained by subtracting the standard deviation from the average calculated value, and the upper limit of the range is added to the average calculated value by the standard deviation. As a substitute value of the value, a value selected from such a value range, preferably a midpoint of the value range is calculated as the evaluation merit value. As a result, the variation (variance) of the load measurement value that is the basis of the substitute value is taken into account in the calculation of the substitute value to be evaluated for the drive decision, and a more reliable drive decision can be made. It becomes possible.

  Furthermore, in the driving judgment, in order to consider the variation (distribution) of the load measurement value that is the basis of the substitute value, the judgment target period is determined based on the load measurement value included in each section obtained by dividing the judgment target period. , And the threshold value setting unit may set a function value derived using the standard deviation as the merit determination threshold value. In this configuration, the merit determination threshold value is calculated using the standard deviation of the average calculation value as a variable, so that in the operation determination using the merit determination threshold value, the variation (variance) of the load measurement value is considered. Will be. The threshold function that derives the merit judgment threshold using the standard deviation of the average operation value as a variable is an increasing function in which the merit judgment threshold increases as the standard deviation increases, but is not necessarily a monotonically increasing function. Or a function that increases in a stepwise manner.

  Since the driving merit function for deriving the driving merit from the average calculation value is generally obtained by a statistical method based on experimental values, empirical values, and the like, it may be necessary to change (upgrade) later. is there. In order to make such a change smoothly and reliably, the operation algorithm or the lookup table of the driving merit function is configured to be updateable through installation from outside the system.

  Since the fuel cell system generates heat when generating power, it can supply power and heat. The supply of heat is generally performed in the form of hot water supply. The load energy handled by the fuel cell system is heat load energy and / or power load energy. Therefore, when the heat load energy and the power load energy are handled, the integrated energy derived from the heat load energy and the power load energy is used as the load energy. In particular, when both the heat load energy and the power load energy are taken in for the operation determination, the load measuring unit derives the integrated load energy using the heat load energy and the power load energy as variables (look-up table). ) Is obtained in advance, the above-described arithmetic processing can be used as it is.

FIG. 1 is a diagram showing a basic configuration of equipment including a fuel cell system. It is a figure which shows the flow of information in the control which selects operation continuation and operation stop of a solid oxide fuel cell in a fuel cell system. FIG. 7 is a diagram illustrating various calculated values calculated based on a load measurement value. 9 is a graph showing a relationship between a standard deviation of a load measurement value and a merit determination threshold. It is a functional block diagram showing an example of an embodiment of a fuel cell system. 5 is a flowchart illustrating an operation example of a fuel cell system. 5 is a flowchart illustrating an operation example of a fuel cell system. 5 is a flowchart illustrating an operation example of a fuel cell system. 5 is a flowchart illustrating an operation example of a fuel cell system. 5 is a flowchart illustrating an operation example of a fuel cell system. 5 is a flowchart illustrating an operation example of a fuel cell system.

  First, a basic configuration of a facility including a fuel cell system according to the present invention will be described with reference to a functional block diagram of FIG. As shown in FIG. 1, the fuel cell system includes a solid oxide fuel cell 1 that supplies energy generated by operation to an energy load unit L, and an operation control device that controls the operation of the solid oxide fuel cell 1. 100. The energy load unit L includes a power load unit 3 and a heat load unit 4. Electric energy generated by the operation of the solid oxide fuel cell 1 is supplied to the power load unit 3, and heat energy generated by the operation of the solid oxide fuel cell 1 is supplied to the heat load unit 4. The power load unit 3 can also consume power supplied from the commercial power supply 15, and the heat load unit 4 can also consume heat supplied from the auxiliary heat source device 11 that generates heat by burning fuel, for example. it can. The operation control device 100 can be realized using a computer system having an information processing function, an information storage function, an information communication function, and the like.

[Supply of power to power load unit 3]
The power generated by the solid oxide fuel cell 1 is supplied to the inverter 12. The inverter 12 sets the generated power of the solid oxide fuel cell 1 to the same voltage and the same frequency as the received power received from the commercial power supply 15. The operation of the inverter 12 is controlled by the operation control device 100. The inverter 12 is electrically connected to a receiving power supply line 14 via a generated power supply line 13. The generated power from the solid oxide fuel cell 1 is supplied to the power load unit 3 via the inverter 12, the generated power supply line 13, and the received power supply line 14. Since the receiving power supply line 14 is connected to the commercial power supply 15, power is supplied to the power load unit 3 from at least one of the solid oxide fuel cell 1 and the commercial power supply 15.

  A power load measuring unit 16 that measures the power load of the power load unit 3 is provided on the received power supply line 14 as a load measurement unit S. The operation control device 100 performs control such that the generated power supplied from the solid oxide fuel cell 1 to the received power supply line 14 by the inverter 12 is equal to the power load detected by the power load measuring means 16. However, when the power load detected by the power load measuring means 16 is smaller than the lowest generated power of the solid oxide fuel cell 1 (that is, the lowest generated power supplied to the received power supply line 14 by the inverter 12), Surplus power is generated. In such a case, the surplus power is consumed by the surplus power consuming electric heater 9 that recovers power instead of heat.

  The electric heater 9 is composed of a plurality of resistance heaters, and heats the cooling water of the solid oxide fuel cell 1 flowing through the exhaust heat recovery passage 6 by operating the exhaust heat recovery pump 7. ON / OFF of the electric heater 9 is switched by an operation switch 10 connected to the output side of the inverter 12. The operation switch 10 is switched so that the power consumption of the electric heater 9 increases as the amount of surplus power of the solid oxide fuel cell 1 increases. The operation of the operation switch 10 is controlled by the operation control device 100.

  It should be noted that what kind of devices are included in the power load unit 3 can be set as appropriate. For example, auxiliary equipment used to operate the solid oxide fuel cell 1 and a heater for preventing freezing of hot water supplied to the heat load unit 4 from being frozen are excluded from the power load unit 3 of the present embodiment. It is also possible to make settings. Further, the standby power of the power load unit 3 may be subtracted from the power load measured in the present embodiment.

[Supply of heat to heat load unit 4]
The heat generated by the solid oxide fuel cell 1 is stored in the hot water storage tank 2 in the form of hot water.
In the present embodiment, hot water is stored in the hot water storage tank 2 in a state where a temperature stratification is formed. That is, the inside of the hot water storage tank 2 is configured such that relatively low temperature hot water is stored in a lower portion thereof, and relatively high temperature hot water is stored in an upper portion thereof. Hot water stored in the hot water storage tank 2 circulates between the solid oxide fuel cell 1 and the hot water storage tank 2 through the exhaust heat recovery path 6.
The flow of hot water in the exhaust heat recovery path 6 is performed by an exhaust heat recovery pump 7. The operation of the exhaust heat recovery pump 7 is controlled by the operation control device 100. For example, the operation control device 100 starts the operation of the solid oxide fuel cell 1 and, when it becomes necessary to cool the solid oxide fuel cell 1, operates the exhaust heat recovery pump 7 to store the hot water. The relatively low-temperature hot and cold water stored in the lower part of the tank 2 flows through the exhaust heat recovery path 6. That is, the hot and cold water circulating in the exhaust heat recovery path 6 is used as cooling water for the solid oxide fuel cell 1. The relatively low-temperature hot and cold water flowing through the exhaust heat recovery passage 6 recovers heat discharged from the solid oxide fuel cell 1 (that is, the hot water is heated by the exhaust heat of the solid oxide fuel cell 1). The hot water becomes relatively hot water and flows into the upper portion of the hot water storage tank 2.

  In addition, a radiator 8 for radiating heat from the hot water flowing from the hot water storage tank 2 to the solid oxide fuel cell 1 through the exhaust heat recovery path 6 is provided in the middle of the exhaust heat recovery path 6. I have. The operation control device 100 stops the operation of the radiator 8 when the temperature of the hot water flowing from the hot water storage tank 2 to the solid oxide fuel cell 1 is lower than the set upper limit temperature. However, when the temperature of the hot water flowing from the hot water storage tank 2 to the solid oxide fuel cell 1 is equal to or higher than the set upper limit temperature (that is, the cooling of the solid oxide fuel cell 1 by the hot water is performed). In the case where the temperature of the hot water can be lowered, the radiator 8 is radiated. The Joule heat generated by energizing the electric heater 9 is recovered by hot water flowing from the solid oxide fuel cell 1 to the hot water storage tank 2 in the exhaust heat recovery path 6.

Hot water stored at an upper portion of the hot water storage tank 2 is supplied to the heat load section 4 through a hot water supply path 5 connected to the upper portion of the hot water storage tank 2. The heat load unit 4 is used for hot water supply or heating. When the heat load unit 4 is used for hot water supply, hot water does not return to the hot water storage tank 2.
When the heat load unit 4 is used for heating, only the heat of the hot water is consumed, and the hot water may return to the hot water storage tank 2. The hot water supply path 5 is provided with an auxiliary heat source device 11 for heating hot water flowing through the hot water supply path 5. The operation control device 100 operates the auxiliary heat source device 11 to supply the hot water to the heat load unit 4 when the temperature of the hot water flowing out of the upper portion of the hot water storage tank 2 is lower than the temperature of the hot water required by the heat load unit 4. The control is performed such that the temperature of the hot and cold water reaches a desired temperature. A heat load measuring unit 17 for measuring the amount of heat consumed by the heat load unit 4 is provided in the middle of the hot and cold water supply path 5 as a load measurement unit S.

  The operator of the fuel cell system can use the information input / output device IOD for exchanging information with the operation control device 100. The information input / output device IOD generally includes a communication terminal installed under a name such as a bathroom remote control or a kitchen remote control. Such a remote control includes an operation button, an information display unit, an audio output unit, and the like. Is provided.

Next, the flow of information in the control for selecting the continuation or the stop of the operation of the solid oxide fuel cell 1 in the fuel cell system will be described with reference to FIG.
As shown in FIG. 2, the operation control device 100 receives a load measurement value (indicated by Lo in FIG. 2) from a load measurement unit S, and inputs the load measurement value to a solid oxide fuel cell (hereinafter simply referred to as a fuel cell). 1) outputs a corresponding operation continuation command or operation stop command. The load measuring unit S measures the load energy required by the energy load unit L at a predetermined sampling interval (for example, one hour to several hours) over a predetermined determination target period (for example, one month), and obtains a load measurement value. Is sent to the operation control device 100 to repeat the measurement process.

  In the example illustrated in FIG. 2, the functional units that execute the basic functions of the operation control device 100 include a load calculation unit 51, a threshold setting unit 52, an operation determination unit 53, and an operation control unit 54. It is. The load calculation unit 51 calculates an average calculation value of the load measurement values. As the average operation value, an arithmetic average value, a weighted average value, an intermediate value, a mode value, or the like, which is a value representative of a group of load measurement values in a predetermined period, can be employed. Is used. In the case where the operation control device 100 handles not only the average calculation value but also a substitute value derived from the average calculation value, the load calculation unit 51 calculates the substitute value. The substitute value is a function value derived using the average operation value as a variable, a so-called converted value. Here, the substitute value is a function value of an operation merit function for deriving the operation merit of the fuel cell 1 from the average calculation value. That is, assuming that the average calculated value is E and the substitute value (operating merit value) is M, the function formula can be represented by M = h (E). The driving merit is the amount of primary energy consumption or the amount of reduction in energy cost or the amount of emission carbon dioxide obtained by operating the fuel cell 1, or the amount of the combination thereof. . However, since there is a limit to the amount of load that the fuel cell 1 can cover, in an area where the load is large, the increase in the driving merit gradually reaches a plateau. For example, assuming that the load is on the horizontal axis and the operation merit is on the vertical axis, the graph shape of the operation merit function is similar to a logarithmic function. Actually, the driving merit function can be obtained by statistical processing using experimental values, empirical values, and the like.

  The driving determination unit 53 compares the average calculation value or the substitute value (driving merit value) with the corresponding determination threshold value, and when the calculated value exceeds the determination threshold value, continues driving (including the start of driving). If it is equal to or less than the threshold value, the operation stop determination result is output. The operation control unit 54 outputs an operation continuation instruction or an operation stop instruction for the fuel cell 1 based on the determination result of the operation determination unit 53.

  In the basic configuration of the threshold value setting unit 52, when the average operation value is used for the operation determination, the threshold value setting unit 52 determines the average operation value at which it is considered that the fuel cell 1 should be operated. And the boundary value between the region of the average calculated value considered to be better when the fuel cell 1 is taken out of service is calculated in advance as a determination threshold. When a substitute value (driving merit value), which is a function value of the driving merit function, is used for the driving determination, the region of the substitute value in which it is considered better to operate the fuel cell 1 and the operation of the fuel cell 1 are stopped. The boundary value of the area of the alternative value considered to be better is calculated in advance as a merit judgment threshold value (judgment threshold value for the driving merit value).

  When the average calculated value or the substitute value is simply used for the driving determination, the variation of the load measurement value as the original data when calculating the average calculated value is not considered. This means that the same operation determination may be performed in a state where the load measurement values are distributed over a wide range and in a state where the load measurement values are densely distributed around a specific value. According to the knowledge of the inventor of the present application, it is known that the operation merit is greater in a state where the load measurement values are distributed and distributed than in a state where the load measurement values are densely distributed.

A method of incorporating the degree of variation of the load measurement value into the driving determination will be described with reference to FIG. The load calculation unit 51 calculates a standard deviation (indicated by σ in FIG. 3) in the determination target period based on the load measurement value included in each section obtained by dividing the determination target period. The average calculated value of the load measurement values sampled in the determination target period is denoted by E, and the average calculated value of the load measurement values in each section is denoted by ei (i is a subscript identifying the section). The standard deviation: σ is calculated from the k average calculated values: ei using a well-known formula. Further, the load calculation unit 51 is a function value derived from the driving merit function using a lower value obtained by subtracting the standard deviation from the average calculation value as an evaluation merit value taking into account the degree of dispersion of the load measurement value. A value between a first value and a second value that is a function value derived from the driving merit function using the upper value obtained by adding the standard deviation to the alternative value, for example, the first value and the second value Is calculated. When the calculation of this evaluation merit value is expressed by an equation,
MV = (1/2) × (h (E−σ) + h (E + σ))
Becomes Here, MV is the evaluation merit value, σ is the standard deviation, E is the average calculation value, and h () is the driving merit function.
The evaluation merit value calculated in this way is compared with a merit judgment threshold value in the operation judgment unit 53, and a judgment result of continuation of operation (including start of operation) or operation stop of the fuel cell 1 is output. .

  In addition to the method of using the evaluation merit value calculated using the standard deviation of the load measurement value as a variable for the operation determination, a method of incorporating the degree of variation of the load measurement value into the operation determination will be described below. In this method, the threshold setting unit 52 sets a function value derived using the standard deviation calculated by the load calculation unit 51 as described above as a merit determination threshold. That is, the merit determination threshold is changed according to the degree of dispersion of the measured load value. Specifically, the merit determination threshold value is a function value of the standard deviation of the measured load value (daily load), and this function is such that the merit determination threshold value increases as the standard deviation increases. FIG. 4 shows an example of such a function in the form of a graph. As described above, by using the merit determination threshold value that dynamically changes according to the standard deviation of the load measurement value, it is possible to incorporate the degree of dispersion of the load measurement value into the operation determination. When the energy load measured by the load measurement unit S and used for the operation determination is both the heat load energy and the power load energy, the load measurement value of the heat load energy and the load measurement value of the power load energy are calculated. As a variable, a function for deriving an integrated load measurement value can be used. By using the integrated load measurement value as the load measurement value, the above-described operation determination can be performed.

  If the operation control device 100 is used, the operation continuation (including the operation start) or the operation stop of the fuel cell 1 is automatically performed based on the determination result of the operation determination unit 53. However, when entrusting the user with the final judgment of driving continuation or driving stop, the judgment result of the driving judgment unit 53 is generally transmitted through a remote control installed under the name of a bathroom remote control, a kitchen remote control, or the like. It is configured to notify the user and issue a driving continuation command or a driving stop command according to the user's instruction using the remote controller.

  Next, several operation modes of the above-described fuel cell system will be described. FIG. 5 shows an example of a common system configuration capable of realizing these operation modes. Here, the operation control device 100 includes the respective functional units described with reference to FIG. 2, and a remote control LC installed in a bathroom or a kitchen is used as the information input / output device IOD of the operation control device 100. . Further, the operation control device 100 can be connected to a remote management center (management computer) 200 operated by a management company that manages the fuel cell system through a communication unit 50 so as to exchange data.

Here, as for the load calculation unit 51, the threshold value setting unit 52, the operation determination unit 53, and the operation control unit 54, which construct the functions of the operation control device 100, the contents described with reference to FIG. Diverted. In addition to the above, the operation control device 100 includes a driving merit function storage unit 55, an output data processing unit 56, an input data processing unit 57, and a notification processing unit 58. In this embodiment, the driving merit function storage unit 55 stores the driving merit value (which is a value indicating the driving merit) from the average calculation value: E calculated by the load calculation unit 51 described with reference to FIGS. An alternative merit function): A driving merit function for deriving M: M = h (E) is stored in the form of a look-up table. Further, in the driving merit function storage unit 55, an expression for deriving an evaluation merit value from the above-described average calculation value: E and standard deviation: σ calculated by the load calculation unit 51, that is, MV = (1/2) × (H (E-σ) + h (E + σ))
Is stored in the form of a lookup table. Also in this equation, since the driving merit function is used, the above two lookup tables can be integrated and constructed.

  The output data processing unit 56 transmits a control signal for controlling various operating devices in the fuel cell system as shown in FIG. 1 based on a command from the operation control unit 54. Operating devices to be controlled include a fuel cell operating device D1 for operating the fuel cell 1, an electric power system operating device D2 for supplying power to the power load unit 3, and a heat load unit 4 such as a water heater. A hot water supply operation device D3 for supplying hot water is included. Further, the output data processing unit 56 transmits a notification signal to a notification device 60 incorporated in the remote controller LC. The notification device 60 includes a display 61 such as a liquid crystal, a buzzer 62, and a lamp 63, and the notification data is generated by a notification processing unit 58. Although not shown, the similar notification device 60 may be installed at a location different from the remote controller LC.

  The input data processing unit 57 performs signal processing on the power load measurement value sent from the power load measurement unit 16 and the heat load measurement value sent from the heat load measurement unit 17, and gives the processed signal to the load calculation unit 51. Further, the input data processing unit 57 is also connected to the remote controller LC, processes an operation signal transmitted through the touch panel 64 of the remote controller, and supplies the processed operation signal to the operation control unit 54 and the like to manually manage the fuel cell system. And control.

  In the management center (management computer) 200, an operation merit function management unit 201 and a fuel cell operation information management unit 202 are constructed. In the management center 200, the operation merit function is corrected based on the fluctuation of various costs. The driving merit function management unit 201 accesses the driving control device 100 of each user's home based on such correction of the driving merit function, and updates the lookup table stored in the driving merit function storage unit 55. . The fuel cell operation information management unit 202 records and manages the operation status (operation specifications, operation conditions, operation history, etc.) of the fuel cell system at each user's home.

  Next, a specific operation example used in the fuel cell system configured as described above will be described. This fuel cell system can be configured to operate in an operation mode selected from various operation modes according to the user's preference. In such a case, the operation mode to be used is selected through the touch panel 64 of the remote controller LC. The operation example described below focuses only on the operation related to the determination as to whether the operation (power generation) by the fuel cell 1 is performed. In the operation example 0, the value to be determined is an average calculation value based on the measured power load value. In the operation examples 1 to 4, the value to be determined is an evaluation merit value obtained from the measured power load value using the driving merit function.

(Operation Example 0): See FIG. 6 First, it is checked whether it is the timing of the operation determination, that is, whether it is the day for determining the operation / stop (# 01). For example, if the timing of this driving determination is set to once a month and the end of the month is set, if the current time is considered to be the end of the month using the calendar function (Yes branch in # 01), the load calculation unit 51 Then, the power load measurement values accumulated during the determination period (one month) are read, and an average operation value, for example, a power load measurement value per day is calculated by, for example, an arithmetic average (# 02). The driving determination unit 53 compares the calculated average calculation value with a determination threshold value set by the threshold value setting unit 52, for example, 4.1 kWh / day (# 03), and determines the average calculation value. If it is equal to or greater than the threshold value (Yes in # 03), the operation determining unit 53 gives the operation control unit 54 a result of the operation start or operation continuation determination (# 04). If the average calculation value is smaller than the determination threshold value (No in # 03), the operation determination unit 53 provides the operation control unit 54 with the determination result of the operation stop or the continuation of the stop (# 04). The operation control unit 54 transmits a command based on the received determination result to the fuel cell operating device D1.

(Operation Example 1): See FIG. 7 First, it is checked whether it is the timing of the driving determination, that is, whether it is the date for determining the driving / stop (# 11). For example, if the timing of this driving determination is set to once a month and the end of the month is set, if the current time is considered to be the end of the month using the calendar function (Yes branch in # 11), the load calculation unit 51 , Read the power load measurement value accumulated during the determination period (one month), calculate the average calculation value (eg, arithmetic average value), and derive the evaluation merit value from the average calculation value using the driving merit function. (# 12). The driving determination unit 53 compares the derived evaluation merit value with the merit determination threshold value set by the threshold value setting unit 52 (# 13), and if the evaluation merit value is equal to or greater than the merit determination threshold value. If it is (Yes branch in # 13), the operation determination unit 53 gives the operation start or operation continuation determination result to the operation control unit 54 (# 14). If the evaluation merit value is smaller than the merit determination threshold value (No branch in # 13), the operation determination unit 53 gives the operation control unit 54 a determination result of the operation stop or the continuation of the stop (# 14). The operation control unit 54 transmits a command based on the received determination result to the fuel cell operating device D1.

(Operation Example 2): Referring to FIG. 8 Steps # 21 to # 24 are the same as Steps # 11 to # 14 of Operation Example 1 shown in FIG. If it is determined in step # 23 that the evaluation merit value is less than the merit determination threshold value (No branch in # 23), the user is notified of the operation stop through the display 61 of the remote controller LC (# 25). The user is urged to respond to the notice of the operation stop via the touch panel 64 of the remote controller LC (# 26). If the user's answer is the start of driving or the continuation of driving, the process proceeds to step # 24, and the driving determination unit 53 gives the determination result of starting or continuation of driving to the driving control unit 54. When the user's answer is the operation stop or the continuation of the stop or no answer within a predetermined time (for example, one day), the operation determination unit 53 gives the operation stop or the stop continuation determination result to the operation control unit 54 (# 27). .

(Operation Example 3): See FIG. 9 This operation example uses the average calculation value handled in Operation Example 0 described above in place of the evaluation merit value in Operation Example 2 described above. First, it is checked whether it is a date for determining operation / stop (# 121). For example, if the timing of this driving determination is set to once a month and the end of the month is set, if the current time is considered to be the end of the month using the calendar function (Yes branch in # 121), the load calculation unit 51 The power load measurement value accumulated during the determination period (one month) is read, and an average operation value (arithmetic average value), for example, a power load measurement value per day is calculated (# 122). The driving determination unit 53 compares the calculated average calculation value with a determination threshold value set by the threshold value setting unit 52, for example, 4.1 kWh / day (# 123), and determines the average calculation value. If it is not less than the threshold value (Yes branch in # 123), the operation determination unit 53 gives the operation start or operation continuation determination result to the operation control unit 54 (# 124). If the average calculated value is smaller than the determination threshold value (No branch in # 123), the user is notified of the operation stop through the display 61 of the remote controller LC (# 125). The user is urged to respond to the notice of the operation stop via the touch panel 64 of the remote controller LC (# 126). If the user's answer is the start of driving or the continuation of driving, the process proceeds to step # 124, and the driving determination unit 53 gives the determination result of starting or continuation of driving to the driving control unit 54. When the user's answer is the operation stop or the continuation of the stop or no answer within a predetermined time (for example, one day), the operation determination unit 53 gives the operation stop or the continuation of the stop to the operation control unit 54 (# 127). .

(Operation Example 4): See FIG. 10 First, it is checked whether it is the timing of the driving determination, that is, whether it is the date for determining the driving / stop (# 31). For example, if the timing of this driving determination is set to once a month and the end of the month is set, and the current time is considered to be the end of the month using the calendar function (Yes branch in # 31), the load calculation unit 51 Then, the power load measurement values for each day accumulated in the determination period (one month) are read out, and an average operation value (for example, an arithmetic average value) for one month and its standard deviation are calculated (# 32). Further, an evaluation merit value is calculated from the average calculated value and the standard deviation using an evaluation merit function (# 33). The driving determination unit 53 compares the derived evaluation merit value with the merit determination threshold set by the threshold setting unit 52 (# 34). If there is (Yes branch in # 34), the operation determination unit 53 gives the operation start or operation continuation determination result to the operation control unit 54 (# 35). If the evaluation merit value is lower than the merit determination threshold value (No branch in # 34), the operation determining unit 53 gives the operation control unit 54 the result of the operation stop or stop continuation determination (# 36). The operation control unit 54 transmits a command based on the received determination result to the fuel cell operating device D1.

(Operation Example 5): See FIG. 11 First, it is checked whether it is the timing of driving determination, that is, whether it is a date for determining driving / stop (# 41). For example, if the timing of this driving determination is set to once a month and the end of the month is set, if the current time is considered to be the end of the month using the calendar function (Yes branch in # 41), the load calculation unit 51 , Read out the daily power load measurement value accumulated during the determination period (one month), calculate an average operation value (for example, an arithmetic average value) for one month and its standard deviation, and calculate the average operation value from the average operation value. Then, an evaluation merit value is derived using the driving merit function (# 42). Further, the threshold setting unit 52 uses the function for deriving the merit determination threshold from the standard deviation described with reference to FIG. 3 and dynamically determines the merit determination according to the standard deviation on a monthly basis. A threshold value is obtained and set as a merit determination threshold value (# 43). The operation determination unit 53 compares the evaluation merit value calculated in step # 42 with the dynamic merit determination threshold set by the threshold setting unit 52 (# 44), and the evaluation merit value is dynamically determined. If the threshold value is equal to or greater than the merit determination threshold value (Yes in # 44), the operation determination unit 53 gives the operation start or operation continuation determination result to the operation control unit 54 (# 45). If the evaluation merit value is less than the dynamic merit determination threshold value (No branch in # 44), the operation determining unit 53 gives the operation control unit 54 the determination result of the operation stop or the continuation of the stop (# 46). . The operation control unit 54 transmits a command based on the received determination result to the fuel cell operating device D1.

  The operation example described with reference to FIGS. 6 to 11 is a reference example of the operation of the fuel cell system, and is not limited to the operation example described above. For example, it is of course possible to combine the above-described operation examples, partially delete functions, and partially add functions.

  In the above-described embodiment, each of the functional units constructed in the operation control device 100 is divided with emphasis on the control to make the description of the control easy to understand. The division can be freely performed within the framework of the present invention.

  Note that the configuration disclosed in the above embodiment (including another embodiment, the same applies hereinafter) can be applied in combination with the configuration disclosed in another embodiment unless there is a contradiction. The embodiment disclosed in the present specification is an exemplification, and the embodiment of the present invention is not limited thereto, and can be appropriately modified without departing from the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a fuel cell system in which operation and stop are performed at appropriate timing while avoiding frequent start and stop of the solid oxide fuel cell.

1: Solid oxide fuel cell (fuel cell)
16: Electric load measurement means 17: Thermal load measurement means 50: Communication unit 51: Load calculation unit 52: Threshold setting unit 53: Operation determination unit 54: Operation control unit 55: Operation merit function storage unit 56: Output data processing Unit 57: Input data processing unit 58: Notification processing unit 60: Notification device 61: Display 64: Touch panel 100: Operation control device 200: Management center 201: Operation merit function management unit IOD: Information input / output device L: Energy load unit LC : Remote control S: Load measurement unit

Claims (8)

A fuel cell system that supplies energy generated from a solid oxide fuel cell capable of selectively controlling operation continuation and operation stop to an energy load unit,
A load measurement unit that measures load energy required by the energy load unit,
A load calculation unit that calculates an average calculation value of load measurement values of the load measurement unit measured over one month as a predetermined determination target period;
Based on either the average calculated value or an alternative value derived from the average calculated value and the determination threshold, at the timing of monthly operation determination, continue or stop operating the solid oxide fuel cell. A driving determination unit for determining
A threshold setting unit for setting the determination threshold,
A fuel cell system comprising: an operation control unit that issues an operation continuation command or an operation stop command to the solid oxide fuel cell based on a determination result of the operation determination unit.   The substitute value is a function value of an operation merit function for deriving the operation merit of the solid oxide fuel cell from the average operation value, and the threshold value setting unit determines the judgment threshold converted to the operation merit. The fuel cell system according to claim 1, wherein the value is set as a merit determination threshold.   3. The method according to claim 2, wherein the operation merit is a primary energy consumption reduction amount, an energy cost reduction amount, an emission carbon dioxide reduction amount, or a combination thereof, which is obtained by operating the solid oxide fuel cell. Fuel cell system. The load calculation unit calculates a standard deviation in the determination target period based on a load measurement value included in each section obtained by dividing the determination target period, and a lower value obtained by subtracting the standard deviation from the average calculation value. A first value that is a function value derived from the driving merit function using a second value that is a function value derived from the driving merit function using an upper value obtained by adding the standard deviation to the alternative value. Is calculated as the evaluation merit value,
4. The fuel cell system according to claim 2, wherein the operation determination unit determines whether to continue or stop the operation of the solid oxide fuel cell based on the evaluation merit value and the merit determination threshold. 5.   The fuel cell system according to claim 4, wherein the evaluation merit value is an average value of the first value and the second value. The load calculation unit calculates a standard deviation in the determination target period based on a load measurement value included in each section dividing the determination target period,
4. The fuel cell system according to claim 2, wherein the threshold value setting unit sets a function value derived using the standard deviation as the merit determination threshold value. 5.   The fuel cell system according to any one of claims 2 to 6, wherein the operation algorithm or the lookup table of the driving merit function can be updated through installation from outside the system.   The load energy is heat load energy and / or power load energy. When heat load energy and power load energy are handled, integrated load derived from heat load energy and power load energy is used as the load energy. The fuel cell system according to any one of claims 1 to 7, wherein energy is used.

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