JP2017174750A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system that performs operation and stop of a solid oxide-type fuel cell at appropriate timing to suppress reduction in an operation merit.SOLUTION: A fuel cell system comprises: a load measurement unit S for measuring load energy requested by an energy load unit L; a load arithmetic unit 51 for calculating the average arithmetic value of load measurement values of the load measurement unit S, the load measurement values being measured in a predetermined determination target period; an operation determination unit 53 for determining operation continuation or operation stop on the basis of a determination threshold value and either the average arithmetic value or a substitution value derived from the average arithmetic value; a threshold value setting unit 52 for setting the determination threshold value; and an operation control unit 54 for giving an operation continuation command or an operation stop command for a solid oxide-type fuel cell on the basis of a determination result of the operation determination unit 53.SELECTED DRAWING: Figure 2

Description

  The present invention relates to 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.

  Fuel cells, particularly solid oxide forms, are highly efficient but have low resistance to start and stop and are suitable for continuous operation. Of course, in the fuel cell, it is possible to follow the power load so as to change the generated power according to the size of the power load of the power load section, but 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 minimum output, the power and heat generated in the fuel cell are left, so the operating merit that should have been obtained by operating the fuel cell (for example, primary energy consumption reduction, 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 Document 1, which describes a fuel cell system including a solid oxide fuel cell, automatically detects when power supply from a solid oxide fuel cell to a load continues for a certain time or longer. In addition, the solid oxide fuel cell is automatically stopped and the solid oxide fuel cell is automatically activated when the power supply from the grid power to the load continues for a certain period of time. It is disclosed that control is performed. Further, DSS operation (daily start / stop operation) in which power generation is stopped at night and power generation is stopped and started in the morning is also disclosed.

JP 2011-198768 A

  However, the solid oxide fuel cell, in particular, has a very high operating temperature and takes a long time to start and stop as compared with the solid polymer fuel cell, so that there is a problem in performing the DSS operation substantially. Furthermore, since the temperature of the member moves up and down from the high temperature state during operation to the normal temperature during stoppage, if such start and stop are repeated, the durability of the component and Reliability may be reduced.

  The present invention has been made in view of the above circumstances, and its object is to prevent the solid oxide fuel cell from being frequently started and stopped, and to perform the solid oxide fuel cell at an appropriate timing. The object is to provide a fuel cell system in which a decrease in operating merits (for example, energy saving, energy saving, and carbon dioxide saving) is suppressed by operating and stopping.

  In order to achieve the above object, a fuel cell system according to the present invention 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 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 a predetermined determination target period; and the average calculation A determination unit for determining whether to continue or stop the operation of the solid oxide fuel cell based on either a value or an alternative value derived from the average calculation value and a determination threshold; and the determination threshold Based on the determination result of the threshold setting unit and the operation determination unit, the operation continuation command or the operation stop command is given to the solid oxide fuel cell. And a that operation control unit.

  In this configuration, whether to continue the operation of the solid oxide fuel cell or whether to stop the operation is determined based on the average calculation value calculated from the load measurement value acquired in the predetermined determination target period, or the average calculation This is performed by comparing and evaluating an alternative value derived from the value, which is an alternative to the average calculation value, and a determination threshold value set in advance by the threshold value setting unit. When the determination result that the operation is 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, an operation stop command is given to the operation control unit, and the operation of the solid oxide fuel cell is stopped. The average calculation 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 an arithmetic average value is usually used.

  Since the average calculation value of the load in a predetermined determination target period is used, an increase or decrease in load due to an unexpected event is flattened, and a robust determination result is obtained. The determination threshold value used in the determination is the average operation value of the past continuous load measurement group and the operation brought about by the operation of the solid oxide fuel cell when such an average operation value is obtained. It can be obtained by statistically processing the relationship with the actual value of merit (for example, energy saving, energy saving, carbon dioxide saving, etc.). Instead of using the average calculation value as it is for the determination, an alternative value obtained by converting the average calculation 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 calculation value of the load into a numerical value (alternative value) that represents the driving merit. Therefore, the substitute value is a function value of an operation merit function that derives the operation merit of the solid oxide fuel cell from the average calculation value, and the threshold value setting unit is converted into the operation merit. The determination threshold value, that is, the merit determination threshold value can be set. Such a driving merit function assigns an average calculation value group of loads generated in a predetermined determination target period as a first variable, and assigns a driving merit actual value corresponding to each average calculation value as a second variable, It can be determined 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. It is like a lookup table in which each average operation value and the corresponding actual driving merit value are made into a matrix and interpolated between them. It may be a thing. As a result, the substitute value becomes a value that embodies the driving merit, and the driving determination using the alternative value generates a determination result in consideration of the driving merit.

  The amount used as the operating merit of the solid oxide fuel cell is the amount of primary energy reduction, energy cost reduction or emission carbon dioxide reduction obtained by the operation of the solid oxide fuel cell, or a combination thereof. Amount. The primary energy consumption reduction is the primary energy consumption that can be reduced by operating the solid oxide fuel cell. When the solid oxide fuel cell is not operated to supply load energy to the load section It is obtained by subtracting from the consumed primary energy amount, the consumed primary energy amount when the solid oxide fuel cell is operated to supply load energy to the load section. The energy cost reduction amount is the energy cost that can be reduced by operating the solid oxide fuel cell. Similar to the primary energy consumption reduction amount, the solid oxide fuel cell is used to supply load energy to the load section. It is obtained by subtracting the energy cost when the solid oxide fuel cell is operated in order to supply the load energy to the load portion from the energy cost when not operating. The amount of CO2 emission reduction is the amount of CO2 emission that can be reduced by operating the solid oxide fuel cell. 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 discharged carbon dioxide when the solid oxide fuel cell is operated to supply load energy to the load portion from the amount of discharged carbon dioxide. Therefore, as an operating merit of the solid oxide fuel cell, considering the cost and environment by handling any one of the primary energy consumption reduction, energy cost reduction, emission carbon dioxide reduction, or a combination thereof, Appropriate operation of the solid oxide fuel cell is realized.

  The average calculation value in a predetermined determination target period may be almost the same value even if the variation (variance) of the load measurement value that is the basis thereof is greatly different. That is, when determining whether to continue or stop driving based on the average calculated value of load or an alternative value calculated based on this average calculated value, it is not possible to take into account variations in load measurement values during the determination target period. In order 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 calculation value from the average calculation value. A first value that is a function value derived from the driving merit function using a lower value obtained by subtracting a standard deviation, and an upper value obtained by adding the standard deviation to the substitute value, and derived from the driving merit function A value between the second value which is a function 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 value. It can be configured to determine continuation or shutdown. In other words, the lower limit of the alternative value range corresponding to the densely calculated average calculated value is used as the alternative value of the average calculated value minus the standard deviation, and the upper limit of the range is added to the average calculated value by the standard deviation. As an alternative value, a value selected from such a range, preferably the midpoint of the range, is calculated as the evaluation merit value. As a result, the calculation of the substitute value to be evaluated for driving determination takes into account the variation (dispersion) of the load measurement value that is the basis of the alternative value, so that a more reliable driving determination can be made. It becomes possible.

  Furthermore, in the driving determination, in order to consider the variation (distribution) of the load measurement value that is the source of the alternative value, the determination target period based on the load measurement value included in each section into which the determination target period is divided It is also possible to calculate the standard deviation at, 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. Therefore, in the operation determination using the merit determination threshold value, variation (dispersion) of the load measurement value is taken into consideration. It will be. The threshold function that derives the merit determination threshold value using the standard deviation of the average operation value as a variable is an increasing function that increases the merit determination threshold value as the standard deviation increases, but it is not necessarily a monotonically increasing function. Alternatively, it may be a function that increases step by step.

  The driving merit function for deriving the driving merit from the average operation value is generally obtained by a statistical method based on experimental values, experience values, etc., and may have to be changed (versioned up) later. is there. In order to make such a change smoothly and reliably, the calculation algorithm or lookup table of the driving merit function is configured to be updatable through installation from outside the system.

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

It is a figure which shows the basic composition of the installation containing a fuel cell system. It is a figure which shows the flow of the information in control which selects the driving | operation continuation of a solid oxide fuel cell in a fuel cell system, and an operation stop. It is a figure explaining the various calculation values calculated based on a load measurement value. It is a graph which shows the relationship between the standard deviation of a load measurement value, and a merit determination threshold value. It is a functional block diagram showing an example of an embodiment of a fuel cell system. It is a flowchart explaining the operation example of a fuel cell system. It is a flowchart explaining the operation example of a fuel cell system. It is a flowchart explaining the operation example of a fuel cell system. It is a flowchart explaining the operation example of a fuel cell system. It is a flowchart explaining the operation example of a fuel cell system. It is a flowchart explaining the operation example of a fuel cell system.

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

[Supplying power to the 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 control device 100 controls the operation of the inverter 12. The inverter 12 is electrically connected to the received power supply line 14 via the 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 received 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.

  In the received power supply line 14, a power load measuring unit 16 that measures the power load of the power load unit 3 is provided as a load measuring 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 consumption electric heater 9 that collects the 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 path 6 by the operation of 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 in the solid oxide fuel cell 1 increases. The operation of the operation switch 10 is controlled by the operation control device 100.

  In addition, what kind of apparatus is included in the power load unit 3 can be set as appropriate. For example, an auxiliary machine used for operating the solid oxide fuel cell 1 and a freezing prevention heater for preventing freezing of hot water supplied to the heat load unit 4 are excluded from the power load unit 3 of the present embodiment. Such a setting is also possible. 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 the heat load section 4]
The hot water storage tank 2 stores heat generated in the solid oxide fuel cell 1 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 temperature stratification is formed. That is, the hot water storage tank 2 is configured such that a relatively low temperature hot water is stored in the lower part thereof and a relatively high temperature hot water is stored in the upper part 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.
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, when it becomes necessary to start operation of the solid oxide fuel cell 1 and to cool the solid oxide fuel cell 1, the operation control device 100 operates the exhaust heat recovery pump 7 to store hot water. The relatively low temperature hot water stored in the lower part of the tank 2 is passed through the exhaust heat recovery path 6. That is, the hot water circulating through the exhaust heat recovery path 6 is used as cooling water for the solid oxide fuel cell 1. The relatively low temperature hot water flowing through the exhaust heat recovery path 6 recovers the 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 flows into the upper part of the hot water storage tank 2.

  In addition, in the middle of the exhaust heat recovery path 6, a radiator 8 for dissipating 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 installed. Yes. 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 operation control device 100 cools the solid oxide fuel cell 1 with hot water). If this is not possible, the radiator 8 is radiated to reduce the temperature of the hot water. Further, 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 middle of the exhaust heat recovery path 6.

The relatively hot water stored in the upper part of the hot water storage tank 2 is supplied to the heat load part 4 through the hot water supply path 5 connected to the upper part 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, the 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 held by 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 the hot water flowing through the hot water supply path 5. When the temperature of the hot water flowing out from the upper part of the hot water storage tank 2 is lower than the temperature of the hot water required by the heat load unit 4, the operation control device 100 operates the auxiliary heat source device 11 and supplies it to the heat load unit 4. Control is performed so that the temperature of the hot and cold water becomes a desired temperature. A thermal load measuring means 17 for measuring the amount of heat consumed by the thermal load unit 4 is provided as a load measuring unit S in the middle of the hot water supply path 5.

  An operator of the fuel cell system can use the information input / output device IOD that exchanges information with the operation control device 100. The information input / output device IOD generally includes a communication terminal installed with a name such as a bathroom remote controller or a kitchen remote controller. Such a remote controller 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 operation continuation and the operation stop 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 inputs a load measurement value (indicated by Lo in FIG. 2) from the load measurement unit S, and a solid oxide fuel cell (hereinafter simply abbreviated as a fuel cell). 1) outputs an operation continuation command or an operation stop command. The load measuring unit S measures the load energy required by the energy load unit L over a predetermined determination target period (for example, one month) at a predetermined sampling interval (for example, 1 hour to several hours), and the load measurement value Is repeated to the operation control device 100.

  In the example shown 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 calculation value, an arithmetic average value, a weighted average value, an intermediate value, a mode value, etc., which are representative of the load measurement value group in a predetermined period, can be adopted, but in general, the arithmetic average value Is used. When the operation control apparatus 100 handles not only the average calculated value but also the alternative value derived from the average calculated value, the load calculating unit 51 calculates the alternative value. The substitute value is a function value derived by using the average operation value as a variable, a so-called conversion value. Here, the substitute value is a function value of an operation merit function that derives the operation merit of the fuel cell 1 from the average calculated value. That is, if the average operation value is E and the alternative value (driving merit value) is M, the functional expression can be expressed as M = h (E). The operating merit is the amount of primary energy reduction, energy cost reduction, emission carbon dioxide reduction obtained by operating the fuel cell 1, or a combination thereof, and the driving merit increases as the load increases. . However, since there is a limit to the amount of load that the fuel cell 1 can cover, the increase in driving merit gradually reaches its peak in a region where the load is large. For example, if the load is on the horizontal axis and the driving merit is on the vertical axis, the graph shape of the driving merit function is similar to a logarithmic function. In practice, the driving merit function can be obtained by statistical processing using experimental values, experience values, and the like.

  The driving determination unit 53 compares the average calculation value or the alternative value (driving merit value) with the corresponding determination threshold value. If the determination threshold value is exceeded, the driving determination unit 53 continues driving (including driving start), determination If it is below the threshold value, the operation stop judgment result is output. The operation control unit 54 outputs an operation continuation command or an operation stop command 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, the threshold value setting unit 52, when an average calculation value is used for operation determination, is an average calculation value that is considered to be better when the fuel cell 1 is operated. And a boundary value between the area of the average calculation value that is considered to be better when the fuel cell 1 is suspended is calculated in advance as a determination threshold value. When an alternative value (driving merit value) that is a function value of the driving merit function is used for driving determination, an alternative value region in which it is considered better to operate the fuel cell 1 and the fuel cell 1 are suspended. The boundary value of the alternative value area that is considered to be better is calculated in advance as a merit determination threshold (determination threshold for driving merit value).

  Simply, when an average calculation value or an alternative value is used for operation determination, variations in load measurement values as original data when calculating the average calculation value are not taken into consideration. There is a possibility that the same operation determination is 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 near a specific value. According to the knowledge of the inventor of the present application, it is known that the driving merit is larger in a state where load measurement values are distributed and distributed than in a state where load measurement values are densely distributed.

A method of incorporating the 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 a load measurement value included in each section into which the determination target period is divided. An average calculation value of the load measurement values sampled in the determination target period is indicated by E, and an average calculation value of the load measurement values in each section is indicated by ei (i is a subscript for identifying the section). The standard deviation: σ is calculated by using a well-known formula from the k average calculation values: ei. 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 variation in the load measurement value. A value between the first value and 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 substitute value, for example, the first value and the second value And the average value is calculated. Expressing this evaluation merit value with a formula,
MV = (1/2) × (h (E−σ) + h (E + σ))
It becomes. Here, MV is an evaluation merit value, σ is the standard deviation, E is the average calculation value, and h () is an operation merit function.
The evaluation merit value calculated in this manner is compared with the merit determination threshold value by the operation determination unit 53, and the determination result of operation continuation (including operation start) or operation stop of the fuel cell 1 is output. .

  A method for incorporating the degree of variation in the load measurement value into the driving determination will be described below in addition to the method of using the evaluation merit value calculated with the standard deviation of the load measurement value as a variable for the driving determination. In this method, the threshold value setting unit 52 sets a function value derived using the standard deviation calculated by the load calculation unit 51 as described above as the merit determination threshold value. That is, the merit determination threshold value is changed according to the degree of variation in the load measurement value. Specifically, the merit determination threshold value is a function value of the standard deviation of the load measurement value (daily load), and the merit determination threshold value increases as the standard deviation increases. An example of such a function is shown in the form of a graph in FIG. 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 variation in the load measurement value into the operation determination. When the energy load measured by the load measuring unit S and used for operation determination is both the thermal load energy and the power load energy, the load measurement value of the thermal load energy and the load measurement value of the power load energy are obtained. A function that derives an integrated load measurement value as a variable can be used. By making this integrated load measurement value a load measurement value, the above-described operation determination can be performed.

  If this operation control apparatus 100 is used, based on the determination result of the operation determination unit 53, operation of the fuel cell 1 is continued (including operation start) or operation is automatically stopped. However, in the case of entrusting the user with the final determination of continuation or stoppage of operation, the determination result of the operation determination unit 53 is generally transmitted via a remote controller or the like installed under the name of a bathroom remote controller or a kitchen remote controller. An operation continuation instruction or an operation stop instruction is given according to a user instruction using a remote controller.

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

Here, the load calculation unit 51, the threshold setting unit 52, the operation determination unit 53, and the operation control unit 54, which have built the function of the operation control device 100, have the contents described with reference to FIG. Diverted. In addition to the above, the driving 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 is described with reference to FIG. 2 and FIG. 3, and the driving merit value (value indicating driving merit from the average calculated value E calculated by the load calculating unit 51) ( A kind of alternative value): Driving merit function for deriving M: M = h (E) is stored in the form of a lookup table. Further, in the driving merit function storage unit 55, an equation 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))
Are stored in the form of a lookup table. Also in this equation, since the driving merit function is used, the above two look-up 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. The operating devices to be controlled include the fuel cell operating device D1 for operating the fuel cell 1, the power operating device D2 for supplying power to the power load unit 3, and the heat load unit 4 such as a water heater. A hot water supply system operating device D3 for supplying hot water is included. Further, the output data processing unit 56 transmits a notification signal to the 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. The notification data is generated by the 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 them to the load calculation unit 51. Furthermore, the input data processing unit 57 is also connected to the remote controller LC, processes an operation signal sent through the touch panel 64 of the remote control, and gives it to the operation control unit 54 and the like, and manually manages this fuel cell system. And allow control.

  The management center (management computer) 200 includes an operation merit function management unit 201 and a fuel cell operation information management unit 202. In the management center 200, the driving merit function is corrected based on fluctuations in various costs. The driving merit function management unit 201 accesses the driving control device 100 at each user's house 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. In addition, the operation example demonstrated below picks up only the operation part regarding determination of whether the driving | operation (power generation) by the fuel cell 1 is performed. In operation example 0, the value to be determined is an average calculation value based on the measured power load value. In operation example 1 to operation example 4, the value to be determined is an evaluation merit value that is further obtained from the power load measurement value using an operation merit function.

(Operation Example 0): Refer to FIG. 6 First, it is checked whether or not it is a timing for driving determination, that is, whether or not it is a date for determining driving / stopping (# 01). For example, if the operation determination timing is set once a month and the end of the month, and the current time is regarded as the end of the month using the calendar function (Yes branch at # 01), the load calculation unit 51 Then, the power load measurement value accumulated in the determination period (one month) is read, and for example, an average calculation value that is a power load measurement value per day is calculated by, for example, arithmetic average (# 02). The driving determination unit 53 compares the calculated average calculated value with the determination threshold set by the threshold setting unit 52, for example, 4.1 kWh / day (# 03), and the average calculated value is determined. If it is equal to or greater than the threshold value (Yes branch at # 03), the operation determination unit 53 gives the operation control unit 54 a determination result of operation start or operation continuation (# 04). If the average calculation value is below the determination threshold value (No branch at # 03), the operation determination unit 53 gives the operation control unit 54 the determination result of operation stop or stop continuation (# 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): Refer to FIG. 7 First, it is checked whether or not it is a timing for driving determination, that is, whether or not it is a date for determining driving / stopping (# 11). For example, if the operation determination timing is set once a month and the end of the month, and the current time is regarded as the end of the month using the calendar function (Yes in # 11), the load calculation unit 51 , Read the power load measurement value accumulated in the judgment period (1 month), calculate the average calculated value (for example, arithmetic average value), and derive the evaluation merit value from the average calculated value using the driving merit function (# 12). The driving determination unit 53 compares the derived evaluation merit value with the merit determination threshold set by the threshold setting unit 52 (# 13), and if the evaluation merit value is equal to or greater than the merit determination threshold. If (Yes branch at # 13), the operation determination unit 53 gives the operation control unit 54 the determination result of operation start or operation continuation (# 14). If the evaluation merit value is below the merit determination threshold value (No branch at # 13), the operation determination unit 53 gives the operation control unit 54 the determination result of operation stop or stop continuation (# 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): Steps # 21 to # 24 of FIG. 8 are the same as steps # 11 to # 14 of Operation Example 1 shown in FIG. If the evaluation merit value is lower than the merit determination threshold value in the check at step # 23 (No branch at # 23), the user is notified of the operation stop through the display 61 of the remote controller LC (# 25). The user's response to the advance notice of operation stop through the touch panel 64 of the remote controller LC is urged (# 26). If the user 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 the driving start or driving continuation to the driving control unit 54. When the user answer is “stop operation”, “continuation of stop”, or “no answer” within a predetermined time (for example, one day), the operation determination unit 53 gives the determination result of operation stop or stop stop to the operation control unit 54 (# 27). .

(Operation Example 3): See FIG. 9 This operation example uses the average operation value handled in the above-described operation example 0 in place of the evaluation merit value in the above-described operation example 2. First, it is checked whether it is a day for determining operation / stop (# 121). For example, if the operation determination timing is set once a month and the end of the month, and the current time is regarded as the end of the month using the calendar function (Yes in # 121), the load calculation unit 51 Then, the power load measurement value accumulated in the determination period (one month) is read, and for example, an average calculation value (arithmetic average value) which is a power load measurement value per day is calculated (# 122). The driving determination unit 53 compares the calculated average calculated value with the determination threshold set by the threshold setting unit 52, for example, 4.1 kWh / day (# 123), and the average calculated value is determined. If it is equal to or greater than the threshold value (Yes in # 123), the operation determination unit 53 gives the operation control unit 54 the determination result of operation start or operation continuation (# 124). If the average calculation value is below the determination threshold value (No branch at # 123), the user is notified of the operation stop through the display 61 of the remote controller LC (# 125). The user's response to the advance notice of operation stop through the touch panel 64 of the remote controller LC is urged (# 126). If the user 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 driving control unit 54 the determination result of the driving start or driving continuation. If the user answer is “stop operation”, “continuation of stop”, or “no answer” within a predetermined time (for example, one day), the operation determination unit 53 gives the determination result of operation stop or stop stop to the operation control unit 54 (# 127). .

(Operation Example 4): Refer to FIG. 10. First, it is checked whether or not it is a timing for driving determination, that is, whether or not it is a date for determining driving / stopping (# 31). For example, if the operation determination timing is set once a month and the end of the month, and the current time is considered to be the end of the month using the calendar function (Yes branch at # 31), the load calculation unit 51 Then, the daily power load measurement value accumulated in the determination period (one month) is read out, and the average operation value (for example, arithmetic average value) for one month and its standard deviation are calculated (# 32). Further, an evaluation merit value is calculated from the average operation 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), and the evaluation merit value is equal to or greater than the merit determination threshold. If there is (Yes in # 34), the operation determination unit 53 gives the operation control unit 54 the determination result of operation start or operation continuation (# 35). If the evaluation merit value is below the merit determination threshold value (No branch at # 34), the operation determination unit 53 gives the operation control unit 54 the determination result of operation stop or stop continuation (# 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): Refer to FIG. 11 First, it is checked whether or not it is the timing for driving determination, that is, whether or not it is the date for determining driving / stopping (# 41). For example, if the operation determination timing is set once a month and the end of the month, and the current time is considered to be the end of the month using the calendar function (Yes in # 41), the load calculation unit 51 Reads the daily power load measurement value accumulated in the determination period (1 month), calculates the average operation value (for example, arithmetic average value) for one month and its standard deviation, and from the average operation value The evaluation merit value is derived using the driving merit function (# 42). Further, the threshold value setting unit 52 uses the function for deriving the merit determination threshold value from the standard deviation described with reference to FIG. 3, and merit determination that dynamically changes according to the standard deviation in units of months. A threshold value is obtained and set as a merit determination threshold value (# 43). The driving 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 dynamic. If it is equal to or greater than the merit determination threshold value (Yes in # 44), the operation determination unit 53 gives the operation control unit 54 the determination result of operation start or operation continuation (# 45). If the evaluation merit value is below the dynamic merit determination threshold value (No branch at # 44), the operation determination unit 53 gives the operation control unit 54 the determination result of operation stop or stop continuation (# 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 shows an operation reference example 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 operation examples described above, delete partial functions, or add partial functions.

  In the above-described embodiment, each functional unit constructed in the operation control apparatus 100 is divided for emphasis in order to make the explanation of the control easy to understand. The division can be performed freely within the framework of the present invention.

  Note that the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in this specification is an exemplification, and the embodiment of the present invention is not limited to this. The embodiment can be appropriately modified without departing from the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a fuel cell system in which the solid oxide fuel cell is operated and stopped at an appropriate timing while avoiding frequent start and stop.

1: Solid oxide fuel cell (fuel cell)
16: Power 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 for supplying 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 that measures load energy required by the energy load unit;
A load calculation unit that calculates an average calculation value of the load measurement values of the load measurement unit measured over a predetermined determination target period;
An operation determination unit that determines whether the solid oxide fuel cell is continuously operated or stopped based on either the average calculated value or an alternative value derived from the average calculated value and a determination threshold;
A threshold setting unit for setting the determination threshold;
Based on the determination result of the operation determination unit, an operation control unit that gives an operation continuation command or an operation stop command to the solid oxide fuel cell;
A fuel cell system comprising:   The substitute value is a function value of an operation merit function for deriving an operation merit of the solid oxide fuel cell from the average calculated value, and the threshold value setting unit is a determination threshold converted into the operation merit. The fuel cell system according to claim 1, wherein the value is set as a merit determination threshold value.   The said operation merit is the consumption primary energy reduction amount or energy cost reduction amount or emission carbon dioxide reduction amount obtained by the operation of the solid oxide fuel cell, or a combination thereof. 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 into which the determination target period is divided, and calculates 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 substitute value; The value between is calculated as an evaluation merit value,
The fuel cell system according to claim 2 or 3, wherein the operation determination unit determines whether the solid oxide fuel cell is continuously operated or stopped based on the evaluation merit value and the merit determination threshold value.   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,
The fuel cell system according to claim 2 or 3, wherein the threshold value setting unit sets a function value derived using the standard deviation as the merit determination threshold value.   The fuel cell system according to any one of claims 2 to 6, wherein the calculation algorithm or 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 the heat load energy and the power load energy are handled, the load energy is an integration derived from the heat load energy and the power load energy. The fuel cell system according to any one of claims 1 to 7, wherein energy is used.

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