JP6494234B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system including a solid oxide fuel cell that supplies energy generated by operation to a load unit, and an operation control device that controls the operation of the solid oxide fuel cell.

  As a fuel cell, a solid polymer fuel cell having a relatively low operating temperature (for example, room temperature to 90 ° C.) or a solid oxide type having a relatively high operating temperature (for example, 750 ° C. to 1000 ° C.). There are fuel cells. In any fuel cell, a power load following operation may be performed in which the generated power is changed in accordance with the magnitude of the power load of the power load unit.

  In cases where the power load is very small or the heat load is very small, the power and heat generated in the fuel cell will remain even if the fuel cell is operated at the minimum output. Operational merits that should have been achieved (for example, primary energy consumption reduction, energy cost reduction, emission carbon dioxide reduction, etc.) are also reduced. Therefore, when the power load is very small or the heat load is very small, it is necessary to consider stopping the operation of the fuel cell.

In the polymer electrolyte fuel cell, since the operation temperature is relatively low as described above, it does not take so long to start and stop. Therefore, it is relatively easy to operate and stop. In addition, even if the operation and the stop are repeated, a large thermal stress is not applied to the components constituting the polymer electrolyte fuel cell, and it is considered that the durability and reliability are not so much affected. For this reason, planning of the operation start timing and operation stop timing is also performed based on the power load and heat load of the load section.
As an example, in Patent Document 1, in a fuel cell system including a polymer electrolyte fuel cell, the operation starts when the load power by the power load unit becomes equal to or higher than a certain power value for a certain time or more. In the condition, the time when the above condition is satisfied is predicted by the power load predicting means, and the solid polymer is used at the timing when the power load increases by starting in advance in consideration of the start time required from the start of operation to power generation. An operation mode is described in which power can be supplied from the fuel cell.

  Patent Document 2 describes a fuel cell system including a solid oxide fuel cell. In order to obtain an effect that the time required for the start-up process can be greatly shortened, this fuel cell system stops the solid oxide fuel cell, and then the temperature of the solid oxide fuel cell is higher than room temperature. Attempting to reboot when in (paragraph 0009). As an example of such restart, DSS operation (daily start / stop operation) is described (paragraph 0087, paragraph 0091) in which power generation is stopped at night and power generation is stopped and morning start is performed (paragraph 0087, paragraph 0091). Patent Document 2 discloses that the solid oxide fuel cell is automatically stopped when power supply from the solid oxide fuel cell to the load continues for a certain period of time or longer. There is also a description that the solid oxide fuel cell is automatically started when the power supply from the power to the load continues for a certain time or longer, but this is the DSS operation described above. Seems to mean.

JP 2005-044714 A JP 2011-198768 A

  In the fuel cell system using the polymer electrolyte fuel cell described in Patent Document 1, the condition that the operation starts when the load power by the power load unit becomes equal to or greater than a certain power value for a certain time or more. Therefore, in an extreme case, there is a possibility that DSS operation in which operation and stop are repeated every day is performed. In the solid oxide fuel cell, such DSS operation cannot be substantially performed. This is because the operating temperature of a solid oxide fuel cell is very high, and it takes a long time to start and stop compared to a solid polymer fuel cell. Further, in the solid oxide fuel cell, the temperature of the member moves up and down from the high temperature state during operation to the normal temperature during stoppage. There is a possibility that the durability and reliability of the parts may be lowered due to the influence of the above.

  In Patent Document 2, an attempt is made to reduce the time required for the startup process by restarting the solid oxide fuel cell at a temperature higher than room temperature. ... and the inside of the power generation / combustion chamber 12 is described as, for example, a high temperature of about 1000 ° C. As described in “It is desirable that the temperature is, for example, 300 ° C. or higher”, a temperature difference of about 700 ° C. is generated between the operation and the stop. Therefore, when starting and stopping are repeated, there is no change in the problem that the durability and reliability of the component may be lowered due to the influence of a stress change applied to the component.

  The present invention has been made in view of the above problems, and its purpose is to allow the solid oxide fuel cell to be operated and stopped at appropriate timing while avoiding frequent start and stop. The present invention provides a fuel cell system.

The characteristic configuration of the fuel cell system according to the present invention for achieving the above object is a solid oxide fuel cell that supplies energy generated by operation to a load section, and controls the operation of the solid oxide fuel cell. a fuel cell system comprising a driving control device, the operation control device when said solid oxide fuel cell is in operation, that the period is in operation more than a predetermined lower limit operation period is made continuous The solid oxide fuel cell should be stopped based on the transition of the system state quantity that is a function of the load energy to be supplied to the load section in the past acquired during the operation determining whether to remain in operation, when said solid oxide fuel cell is stopped, the constraint that the period is being stopped more than a predetermined lower limit stop period is made continuous While the matter, on the basis of transition functions in a system state of the load energy to be supplied to the load section of the past which is obtained during the stop, the or stopped to be operated SOFC The point is to determine whether or not to leave.

  According to the above characteristic configuration, the operation control device is configured such that the period during which the solid oxide fuel cell is operating continues for a predetermined lower limit operating period or longer, and the solid oxide fuel cell is stopped. There is a constraint that allows the period to continue beyond a predetermined lower limit stop period. That is, it can be avoided that the period during which the operation of the solid oxide fuel cell continues and the period during which the stop continues are shortened. As a result, it is ensured that the operation and stop of the solid oxide fuel cell are not repeated frequently.

In addition, when the solid oxide fuel cell is in operation, the operation control device is based on the transition of the system state quantity, which is a function of the load energy to be supplied to the past load section acquired during the operation. Determine whether the solid oxide fuel cell should be stopped or left in operation. In addition, when the solid oxide fuel cell is stopped, the operation control device is based on the transition of the system state quantity that is a function of the load energy to be supplied to the past load section acquired during the stop, It is determined whether the solid oxide fuel cell should be operated or left stationary. In other words, the operation control device refers to the transition of the system state quantity that is a function of the load energy to be supplied to the past load unit. That is, the operation control device refers to constant, small and constant). As a result, the operation control device preferably operates the solid oxide fuel cell if the past load energy remains constant, for example, increasing or large, and the past load energy is constant, for example, decreasing or small. The solid oxide fuel cell tends to be operated to supply load energy, or the solid oxide fuel cell is It can be determined whether there is a tendency to stop.
Accordingly, it is possible to provide a fuel cell system in which the solid oxide fuel cell is operated and stopped at appropriate timing while avoiding frequent start and stop.

Another characteristic configuration of the fuel cell system according to the present invention is that the system state quantity is load energy to be supplied to the load unit, and the operation control device is operating the solid oxide fuel cell. when, on the basis of transition of the past of the load energy in its operation, to determine whether to leave the solid oxide or during operation should stop the fuel cell, the solid oxide fuel cell when there is stopped, on the basis of transition of the past of the load energy in the stopped lies in determining whether to leave the solid oxide or stopped to be operated fuel cell .

According to the above characteristic configuration, when the solid oxide fuel cell is in operation, the operation control device should stop the solid oxide fuel cell based on the transition of the past load energy during the operation. Or whether it should remain in operation. Further, the operation control device, when the solid oxide fuel cell is stopped, on the basis of transition of the past load energy in the stopped, or not to operate the solid oxide fuel cell or suspended Determine whether to leave. That is, the operation control apparatus can know the past trend of load energy by referring to the transition of load energy to be supplied to the load unit. As a result, the operation controller determines whether the solid oxide fuel cell tends to be operated to supply load energy or whether the solid oxide fuel cell tends to be stopped. Can do.

Yet another characterizing feature of the fuel cell system according to the present invention, the operation control device when said solid oxide fuel cell is in operation, the load energy in past predetermined period in the operation A moving average value is derived for each predetermined timing, and if the moving average value is equal to or greater than a first threshold value, it is determined that the solid oxide fuel cell should be kept in operation, and the moving average value is If it is less than the first threshold continuously for one set period or more, it is determined that the solid oxide fuel cell should be stopped, and when the solid oxide fuel cell is stopped, the past during the stop A moving average value of the load energy in a predetermined period of time is derived for each predetermined timing, and the solid oxide fuel cell is determined if the moving average value is equal to or greater than a second threshold continuously for a second set period or longer. If it is determined that the Lies in determining an average value should remain in stopping the solid oxide fuel cell is less than the second threshold value.

According to the above characteristic configuration, the operation control device derives the moving average value of the load energy in the past predetermined period for each predetermined timing, and determines the solid oxide fuel according to the magnitude of the moving average value. It is determined whether the battery should be operated or stopped. In other words, deriving and referencing the moving average value of load energy in the past predetermined period means that the load energy in the past predetermined period is changed in a short period of time in the past predetermined period (that is, short-term This is referred to as a leveled value.
Then, when the solid oxide fuel cell is in operation, the operation control device, if the moving average value of the load energy in the past predetermined period during the operation is greater than or equal to the first threshold (that is, the load energy). If the solid oxide fuel cell is to remain in operation and the moving average value is continuously less than the first threshold for the first set period or longer (that is, the load energy is It is determined that the solid oxide fuel cell should be stopped (if it is relatively small continuously for a relatively long time). In addition, when the solid oxide fuel cell is stopped, the operation control device is configured such that the moving average value of the load energy in the past predetermined period when the solid oxide fuel cell is stopped continuously exceeds the second threshold value for the second set period or longer. If (ie, if the load energy is relatively large for a relatively long time), it is determined that the solid oxide fuel cell should be operated, and if the moving average value is less than the second threshold value (ie, If the load energy is relatively small, it is determined that the solid oxide fuel cell should remain stopped. As described above, the operation control device can determine whether the solid oxide fuel cell should be operated or stopped based on the transition of the past load energy.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. Accordingly, at least one of the change to the decrease side of the first threshold and the change to the increase side of the first set period is performed.

  According to the above characteristic configuration, when the first threshold value is changed to the decreasing side and when the first setting period is changed to the increasing side, the solid oxide fuel cell in operation is It becomes easier to determine that the vehicle should remain in operation. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. Accordingly, at least one of the change to the increase side of the second threshold and the change to the increase side of the second setting period is performed.

  According to the above characteristic configuration, when the change to the increase side of the second threshold is made and when the change to the increase side of the second set period is made, the solid oxide fuel cell that is stopped is It becomes easier to determine that the vehicle should remain stopped. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

Yet another characterizing feature of the fuel cell system according to the present invention, the operation control device when said solid oxide fuel cell is in operation, the load energy in past predetermined period in the operation While deriving the moving average value a plurality of times for each predetermined timing, if the moving average value is less than the third threshold value, the operating integrated value is increased by a specified amount, and the moving average value is equal to or more than the third threshold value. And the operating integrated value is reduced by a specified amount on condition that the operating integrated value is not reduced below a predetermined minimum value. If the operating integrated value is less than the upper limit operating integrated value, the solid oxide fuel cell is being operated. If the operating integrated value is the upper limit operating integrated value, it is determined that the solid oxide fuel cell should be stopped, and the solid oxide fuel cell is stopped On one occasion, the While deriving the moving average value of the load energy for a predetermined period in the past during a stop multiple times for each predetermined timing, if the moving average value is greater than or equal to a fourth threshold value, the integrated value at the time of stoppage is a specified amount When the moving average value is less than the fourth threshold, the stop integrated value is decreased by a specified amount on condition that the stop integrated value is not decreased below a predetermined minimum value, and the stop integrated value is the upper limit stop integrated value. If it is determined that the solid oxide fuel cell should be operated, and if the integrated value at the time of stoppage is less than the integrated value at the time of stoppage, the solid oxide fuel cell should be stopped. It is in the point to judge.

  According to the above characteristic configuration, the operation control device derives the moving average value of the load energy in the past predetermined period while deriving the moving average value of the load energy in the past predetermined period for a plurality of times for each predetermined timing. While deriving a plurality of times at predetermined timings, it is determined whether the solid oxide fuel cell should be operated or stopped according to the magnitude of the moving average value. In other words, deriving and referencing the moving average value of load energy in the past predetermined period means that the load energy in the past predetermined period is changed in a short period of time in the past predetermined period (that is, short-term This is referred to as a leveled value.

Then, when the solid oxide fuel cell is in operation, the operation control device calculates an integrated value during operation when the moving average value of the load energy in the past predetermined period during the operation is less than the third threshold value. Increase by the specified amount and if the moving average value is greater than or equal to the third threshold, the operating integrated value is decreased by the specified amount on condition that the operating integrated value is not reduced below the predetermined minimum value. If it is less than the value, it is determined that the solid oxide fuel cell should remain in operation, and if the integrated value during operation is the integrated value during upper limit operation, it is determined that the solid oxide fuel cell should be stopped. That is, when the solid oxide fuel cell is in operation, the operation control device is the number of times that the moving average value is less than the third threshold (that is, the period during which the load energy is changing at a relatively small value). And the number of times that the moving average value is equal to or greater than the third threshold (that is, the period during which the load energy is changing at a relatively large value) is continuously counted as the integrated value during operation, It is possible to determine whether or not the trend is relatively large or relatively small.

In addition, when the solid oxide fuel cell is stopped, the operation control device calculates an integrated value at the time of stop when the moving average value of the load energy in the past predetermined period during the stop is equal to or more than the fourth threshold value. If the moving average value is less than the fourth threshold, the stop accumulated value is decreased by a specified amount if the moving average value is less than the fourth threshold, and the stop accumulated value is the upper limit stop accumulated value. If the value is a value, it is determined that the solid oxide fuel cell should be operated, and if the integrated value at the time of stop is less than the integrated value at the time of stop, it is determined that the solid oxide fuel cell should be stopped. That is, when the solid oxide fuel cell is stopped, the operation control device is the number of times that the moving average value is equal to or greater than the fourth threshold (that is, the period during which the load energy is changing at a relatively large value). , And the number of times that the moving average value is less than the fourth threshold (that is, the period during which the load energy is changing at a relatively small value) is continuously counted as the integrated value at the time of stoppage, It is possible to determine whether or not the trend is relatively large or relatively small.
Then, the operation control device can determine whether the solid oxide fuel cell should be operated or stopped based on the past load energy tendency.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. Accordingly, at least one of the change to the decrease side of the third threshold value and the change to the increase side of the upper limit operation integrated value is performed.

  According to the above characteristic configuration, when the change to the decrease side of the third threshold value is performed and the change to the increase side of the upper limit operation integrated value is performed, the solid oxide fuel cell in operation is It becomes easy to determine that it should remain during the operation. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. Accordingly, at least one of the change to the increase side of the fourth threshold and the change to the increase side of the upper limit stop integrated value is performed.

  According to the above characteristic configuration, when the fourth threshold value is changed to the increasing side, and when the upper limit stop-time integrated value is changed to the increasing side, the solid oxide fuel cell that is stopped is It becomes easier to determine that the vehicle should remain stopped. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

Still another characteristic configuration of the fuel cell system according to the present invention includes a solid oxide fuel cell that supplies energy generated by operation to a load unit, and an operation control device that controls the operation of the solid oxide fuel cell. a fuel cell system comprising, the operation control device when said solid oxide fuel cell is in operation, the constraint that the period is in operation more than a predetermined lower limit operation period is made continuous while derives the predicted value of the future of the load energy on the basis of transition of the past of the load energy, leaving in operation the solid oxide fuel cell if said predicted value is a fifth threshold value or more determines that it should be, the predicted value is determined to be stopping the solid oxide fuel cell is less than the fifth threshold value, when the solid oxide fuel cell is stopped, in its stopped While the constraint that period than a predetermined lower limit stop period that is made continuous, derive the predicted value of the future of the load energy on the basis of transition of the past of the load energy, the predicted value is the sixth threshold value or more the determines that it should be operating a solid oxide fuel cell, it is determined that the predicted value is to be left in stopping the solid oxide fuel cell is less than the sixth threshold value if the The operation control device changes the fifth threshold value to a decreasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. In the point.

According to the above characteristic configuration, the operation control device is configured such that the period during which the solid oxide fuel cell is operating continues for a predetermined lower limit operating period or longer, and the solid oxide fuel cell is stopped. There is a constraint that allows the period to continue beyond a predetermined lower limit stop period. That is, it can be avoided that the period during which the operation of the solid oxide fuel cell continues and the period during which the stop continues are shortened. As a result, it is ensured that the operation and stop of the solid oxide fuel cell are not repeated frequently.
In addition, according to this feature configuration, the operation control device derives a predicted value of the future load energy based on the transition of the past load energy. That is, the derived predicted value of the future load energy is a value according to the past change tendency of the load energy.
When the solid oxide fuel cell is in operation, the operation control device should leave the solid oxide fuel cell in operation if the predicted value during operation is greater than or equal to the fifth threshold value. If the predicted value during operation is less than the fifth threshold value, it is determined that the solid oxide fuel cell should be stopped. In addition, when the solid oxide fuel cell is stopped, the operation control device determines that the solid oxide fuel cell should be operated if the predicted value during the stop is equal to or greater than the sixth threshold value, and stops. If the predicted value is less than the sixth threshold value, it is determined that the solid oxide fuel cell should remain stopped. That is, the operation control device determines whether the solid oxide fuel cell should be operated or stopped by determining the magnitude of the predicted value in accordance with the past load energy change tendency. can do.
Furthermore, according to the present feature configuration, when the fifth threshold value is changed to the decreasing side, it is easy to determine that the solid oxide fuel cell that is in operation should remain in operation. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

Still another characteristic configuration of the fuel cell system according to the present invention includes a solid oxide fuel cell that supplies energy generated by operation to a load unit, and an operation control device that controls the operation of the solid oxide fuel cell. When the solid oxide fuel cell is in operation, the operation control device has a restriction condition that a period during the operation is continued for a predetermined lower limit operation period or longer. However, a predicted value of the future load energy is derived based on the transition of the load energy in the past, and the solid oxide fuel cell is kept in operation if the predicted value is equal to or greater than a fifth threshold value. If the predicted value is less than the fifth threshold value, it is determined that the solid oxide fuel cell should be stopped, and when the solid oxide fuel cell is stopped, A predicted value of the future load energy is derived based on the transition of the load energy in the past, and the predicted value is greater than or equal to a sixth threshold value. If so, it is determined that the solid oxide fuel cell should be operated, and if the predicted value is less than the sixth threshold, it is determined that the solid oxide fuel cell should be stopped, and The operation control device changes the sixth threshold value to the increasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. In the point.

According to the above characteristic configuration, the operation control device is configured such that the period during which the solid oxide fuel cell is operating continues for a predetermined lower limit operating period or longer, and the solid oxide fuel cell is stopped. There is a constraint that allows the period to continue beyond a predetermined lower limit stop period. That is, it can be avoided that the period during which the operation of the solid oxide fuel cell continues and the period during which the stop continues are shortened. As a result, it is ensured that the operation and stop of the solid oxide fuel cell are not repeated frequently.
In addition, according to this feature configuration, the operation control device derives a predicted value of the future load energy based on the transition of the past load energy. That is, the derived predicted value of the future load energy is a value according to the past change tendency of the load energy.
When the solid oxide fuel cell is in operation, the operation control device should leave the solid oxide fuel cell in operation if the predicted value during operation is greater than or equal to the fifth threshold value. If the predicted value during operation is less than the fifth threshold value, it is determined that the solid oxide fuel cell should be stopped. In addition, when the solid oxide fuel cell is stopped, the operation control device determines that the solid oxide fuel cell should be operated if the predicted value during the stop is equal to or greater than the sixth threshold value, and stops. If the predicted value is less than the sixth threshold value, it is determined that the solid oxide fuel cell should remain stopped. That is, the operation control device determines whether the solid oxide fuel cell should be operated or stopped by determining the magnitude of the predicted value in accordance with the past load energy change tendency. can do.
Furthermore, according to the present feature configuration, when the sixth threshold value is changed to the increase side, it is easy to determine that the solid oxide fuel cell that is stopped is to remain stopped. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. Accordingly, the sixth threshold value is changed to the increasing side.

  According to the above characteristic configuration, when the sixth threshold value is changed to the increasing side, it is easy to determine that the solid oxide fuel cell being stopped should remain stopped. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

Still another characteristic configuration of the fuel cell system according to the present invention is that the system state quantity is a primary energy consumption reduction amount obtained when load energy to be supplied to the load unit is supplied from the solid oxide fuel cell. Or, it is an operation merit that is an energy cost reduction amount or an emission carbon dioxide reduction amount, or a primary combination of any two or three of them, and the operation control device is operating the solid oxide fuel cell. when it derives the actual value of the operating benefits when fed past the load energy within a predetermined time period from the solid oxide fuel cell in its operation, the actual value is the seventh threshold value or more If it is determined that the solid oxide fuel cell should remain in operation, the solid oxide fuel cell is stopped if the actual value is less than the seventh threshold value. Can and judgment, when said solid oxide fuel cell is stopped, the when it is assumed that the past of the load energy within a predetermined time period at the stopped supplied from the solid oxide fuel cell A predicted value of driving merit is derived, and if the predicted value is equal to or greater than an eighth threshold, it is determined that the solid oxide fuel cell should be operated, and if the predicted value is less than the eighth threshold, the solid The point is that it is determined that the oxide fuel cell should be stopped.

According to the above characteristic configuration, when the solid oxide fuel cell is in operation, the operation control device is configured to supply load energy from the solid oxide fuel cell within a predetermined past period during the operation. Derived actual value of driving merit. In other words, the larger the actual value of the derived operation merit, the greater the merit of operating the solid oxide fuel cell because the load energy in the past predetermined period during the operation has shifted to a relatively large value. That is, it can be predicted that the merit of operating the solid oxide fuel cell is relatively large even at least in the immediate future. Therefore, when the solid oxide fuel cell is in operation, the operation control apparatus determines that the solid oxide fuel cell should remain in operation if the actual value of the operation merit is equal to or greater than the seventh threshold value. If the actual value of the operation merit is less than the seventh threshold value, it is determined that the solid oxide fuel cell should be stopped.
Further, the operation control device, when the solid oxide fuel cell is stopped, the operation benefits when assuming the past load energy within a predetermined time period at the stopped and is supplied from the solid oxide fuel cell The predicted value of is derived. In other words, the larger the predicted value of the derived operation merit, the greater the merit of operating the solid oxide fuel cell because the load energy within the past predetermined period during the stoppage was relatively large. That is, it can be predicted that the merit of operating the solid oxide fuel cell is relatively large even at least in the immediate future. Therefore, when the solid oxide fuel cell is stopped, the operation control device determines that the solid oxide fuel cell should be operated if the predicted value of the operation merit is equal to or greater than the eighth threshold, and the operation is performed. If the predicted value of merit is less than the eighth threshold, it is determined that the solid oxide fuel cell should remain stopped.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. As a result, the seventh threshold value is changed to the decreasing side.

  According to the above characteristic configuration, when the seventh threshold value is changed to the decreasing side, it is easy to determine that the solid oxide fuel cell being operated should remain in operation. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

  Still another characteristic configuration of the fuel cell system according to the present invention is that the operation controller increases the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state. As a result, the eighth threshold value is changed to the increasing side.

  According to the above characteristic configuration, when the eighth threshold value is changed to the increasing side, it is easy to determine that the solid oxide fuel cell being stopped should remain stopped. As a result, since the frequency with which the solid oxide fuel cell is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell are hardly adversely affected.

Still another characteristic configuration of the fuel cell system according to the present invention is that the load energy is heat load energy and power load energy, and the operation control device is configured such that when the solid oxide fuel cell is in operation, When the past transition of the thermal load energy during the operation satisfies the first shutdown condition, or when the past transition of the power load energy during the operation satisfies the second shutdown condition, the solid oxide form determines that should stop the fuel cell does not satisfy the trend of past the thermal load energy the first shutdown condition in its operation, the transitive past the power load energy in its operation the 2 When it is determined that the solid oxide fuel cell is to remain in operation when the shutdown condition is not satisfied, and the solid oxide fuel cell is in the first shutdown condition When is stopped by Tasa it was, driving the historical trends and the solid oxide fuel cell when transition is first operation start condition is satisfied for the power load energy of the thermal load energy in the stopped It is determined that the solid oxide fuel cell should be stopped when the first operation start condition is not satisfied, and the solid oxide fuel cell is in the second operation stop condition. Is determined that the solid oxide fuel cell should be operated when the past transition of the electric power load energy during the stop condition satisfies the second operation start condition, When the second operation start condition is not satisfied, it is determined that the solid oxide fuel cell should be stopped.

According to the above characteristic configuration, the operation control device does not monitor only one of the thermal load energy and the power load energy but monitors both of them. Then, the operation control device sets an operation stop condition (first operation stop condition and second operation stop condition) for each of the transition of the past thermal load energy and the transition of the past power load energy during the operation. Thus, it is determined whether the solid oxide fuel cell should be kept in operation or stopped. As described above, the determination of whether the solid oxide fuel cell should be kept operating or stopped should be referred to the past transition of heat load energy and the past transition of power load energy during the operation . In other words, the determination of whether the solid oxide fuel cell should be kept in operation or stopped should be performed without omission.

Further, when the solid oxide fuel cell is stopped because the first operation stop condition related to the transition of the past heat load energy is satisfied, at least the past heat load energy during the stop is determined. Whether or not the solid oxide fuel cell should be operated is determined with reference to the transition of. In addition, when the solid oxide fuel cell is stopped due to the fact that the second operation stop condition relating to the transition of the past power load energy is satisfied , the past power load energy during the stop is determined. Whether or not the solid oxide fuel cell should be operated is determined with reference to the transition of. As described above, when the operation control device determines that the solid oxide fuel cell should be stopped from the viewpoint of the transition of the thermal load energy, the operation control device also selects the solid oxide fuel cell from the viewpoint of the transition of the thermal load energy. If it is determined that the solid oxide fuel cell should be stopped from the viewpoint of the transition of the electric power load energy, the solid oxide fuel cell is similarly removed from the viewpoint of the transition of the electric power load energy. Make a decision when driving again. As a result, it is possible to make the determination results consistent after stopping the solid oxide fuel cell and operating again.

It is a figure which shows the structure of the installation containing the fuel cell system which concerns on this invention. It is a state transition diagram explaining the driving | running aspect of the fuel cell system of 1st Embodiment. It is a state transition diagram explaining the driving | running aspect of the fuel cell system of 2nd Embodiment. It is a state transition diagram explaining the driving | running aspect of the fuel cell system of 3rd Embodiment. It is a state transition diagram explaining the driving | running aspect of the fuel cell system of 4th Embodiment. It is a state transition diagram explaining the driving | running aspect of the fuel cell system of 5th Embodiment. It is a flowchart explaining the driving | running aspect of the fuel cell system of 6th Embodiment. It is a flowchart explaining the driving | running aspect of the fuel cell system of 7th Embodiment.

  A configuration of equipment including a fuel cell system according to the present invention, which is common to each embodiment, will be described first with reference to the drawings. Subsequently, the operation mode of the fuel cell system of each embodiment will be described separately.

  FIG. 1 is a block diagram showing a configuration of equipment including a fuel cell system according to the present invention. As shown in the figure, the fuel cell system includes a solid oxide fuel cell 1 that supplies energy generated by operation to a load L, and an operation control device C that controls the operation of the solid oxide fuel cell 1. Prepare. The load unit L includes an electric 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. As will be described later, the power load unit 3 can also consume the power supplied from the commercial power source 15, and the heat load unit 4 is supplied from, for example, an auxiliary heat source device 11 that generates heat by burning fuel. Heat can be consumed. The operation control device C can be realized using a device 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 of the inverter 12 is controlled by the operation control device C. The inverter 12 is electrically connected to the received power supply line 14 via the generated power supply line 13. Then, the generated power from the solid oxide fuel cell 1 is supplied to the power load unit 3 through the inverter 12, the generated power supply line 13 and the received power supply line 14. The received power supply line 14 is connected to a commercial power supply 15. As a result, 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.

  The received power supply line 14 is provided with power load measuring means 16 for measuring the power load of the power load unit 3. The operation control device C 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 C.

  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 C. For example, when it becomes necessary to start the operation of the solid oxide fuel cell 1 and to cool the solid oxide fuel cell 1, the operation control device C 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 water becomes relatively hot and 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 C 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 C 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.
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. ing.

  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. The operation control device C operates the auxiliary heat source device 11 to supply to the heat load unit 4 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. Control is performed so that the temperature of the hot and cold water becomes a desired temperature. In the middle of the hot water supply path 5, a heat load measuring means 17 for measuring the amount of heat consumed by the heat load unit 4 is provided.

  An operator of the fuel cell system can use the information input / output device 18 that exchanges information with the operation control device C. The information input / output device 18 is a device including an operation button, an information display unit, a sound output unit, and the like, and is generally installed with a name such as a bathroom remote control or a kitchen remote control.

<First Embodiment>
The fuel cell system according to the first embodiment will be described below.
FIG. 2 is a state transition diagram illustrating an operation mode of the fuel cell system according to the first embodiment. This state transition diagram shows under what conditions the operation state and the stop state of the solid oxide fuel cell 1 can be switched.

  When the solid oxide fuel cell 1 is in operation, the operation control device C uses a past condition acquired during operation while limiting the continuous operation period to a predetermined lower limit operation period or longer. Based on the transition of the system state quantity that is a function of the load energy to be supplied to the load part L, it is determined whether the solid oxide fuel cell 1 should be stopped or left in operation, and the solid oxide form When the fuel cell 1 is stopped, the load energy to be supplied to the past load portion L acquired during the stop is set as a constraint condition that the stop period is continued for a predetermined lower limit stop period or longer. Based on the transition of the system state quantity as a function, it is determined whether the solid oxide fuel cell 1 should be operated or should be stopped.

  In the present embodiment, the system state quantity is load energy to be supplied from the solid oxide fuel cell 1 to the load L, and in particular, is a power load to be supplied to the power load 3. Then, when the solid oxide fuel cell 1 is in operation, the operation control device C should stop or operate the solid oxide fuel cell 1 based on the transition of the past load energy during operation. When the solid oxide fuel cell 1 is stopped, the solid oxide fuel cell 1 should be operated based on the transition of the past load energy during the stop. Or whether it should remain stopped.

  Processes 1A, 1B, and 1C in FIG. 2 are processes performed when the solid oxide fuel cell 1 is in operation, and processes 1D, 1E, and 1F in FIG. This is a process that is performed when it is stopped. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.

〔driving〕
In the operation control device C, when the solid oxide fuel cell 1 is switched from the stopped state to the operating state, first, in the processing 1C, power generation is continued unconditionally for 240 hours. In other words, the constraint condition is that the period during operation is continued for a predetermined lower limit operation period (240 hours or more). And operation control device C will shift to processing 1B, if 240 hours pass in processing 1C.

The operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. Then, the operation control device C obtains a moving average value of load energy (average power load data for every hour) in the past predetermined period during operation (for example, continuous 12 hours) in the process 1B, for example, 1 Derived every time, it is determined whether the moving average value is, for example, 170 W or more. As long as the moving average value is 170 W or more, the determination of the process 1B is continuously performed. That is, the operation control apparatus C continues the operation of the solid oxide fuel cell 1 as long as the moving average value is 170 W or more in the process 1B.
On the other hand, in the process 1B, the operation control device C has a moving average value of load energy (average power load data for every hour) in a past predetermined period (for example, continuous 12 hours) during operation. For example, when it is less than 170 W, the processing shifts to the processing 1A.
In this way, deriving and referring to the moving average value of the power load in the past predetermined period means that the power load in the past predetermined period is changed in a short period within the past predetermined period (that is, , Short-term change trends) are referred to as leveled values.

In the process 1A, the operation control device C calculates the moving average value of the load energy (average power load data for every hour) in the past predetermined period (for example, 12 hours) during operation in the same manner as the above-described example. Derived at every predetermined timing (for example, every hour), if the moving average value is not less than the first threshold (for example, 220 W), it is determined that the solid oxide fuel cell 1 should be kept in operation, The process proceeds to process 1B.
On the other hand, the operation control device C stops the solid oxide fuel cell 1 if the moving average value is continuously longer than the first set period (for example, 240 hours) and less than the first threshold value (for example, 220 W). The solid oxide fuel cell 1 is stopped and the process 1D is started. That is, the operation control apparatus C monitors the transition of the moving average value (that is, the transition of load energy) during the first setting period. In FIG. 2, the term “low power state continuation timer” is used to indicate a state in which the power load continues while being small.

  Thus, in the present embodiment, the condition when shifting from the process 1A to the process 1B is whether or not the moving average value is 220 W or more, and the condition when shifting from the process 1B to the process 1A is The threshold value is different, such as whether the moving average value is 170 W or more. This is to avoid the possibility that the processing frequently goes back and forth between the processing 1A and the processing 1B in accordance with slight fluctuations in the moving average value when the same threshold value is set.

[Stopped]
When the solid oxide fuel cell 1 is switched from the operating state to the stopped state, the operation control device C first continues unconditionally for 24 hours in the process 1D. That is, the constraint condition is that the period during the stop is continued for a predetermined lower limit stop period (240 hours or more). And operation control device C will shift to processing 1E, if 240 hours pass in processing 1D.

The operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. In operation 1E, the operation control apparatus C obtains, for example, a moving average value of load energy (average power load data for every hour) in the past predetermined period (for example, continuous 12 hours) during stoppage, for example, 1 Derived every time, it is determined whether the moving average value is less than 220W, for example. As long as the moving average value is less than 220 W, the determination of the process 1E is continuously performed. That is, the operation control device C continues to stop the solid oxide fuel cell 1 while the moving average value is less than 220 W in the process 1E.
On the other hand, in the process 1E, the operation control device C has a moving average value of load energy (average power load data for every hour) in the past predetermined period (for example, continuous 12 hours) during the stop. For example, when the power is 220 W or more, the process proceeds to the process 1F.

In the process 1F, the operation control device C, when the solid oxide fuel cell 1 is stopped, in the same manner as the above-described example, the load energy (1 for the past predetermined period (for example, 12 hours) during the stop) A moving average value of average power load data for each hour) is derived at every predetermined timing (for example, every hour), and the moving average value continues for the second set period (for example, 24 hours) for a second threshold ( For example, if it is 170 W or more, it is determined that the solid oxide fuel cell 1 should be operated, the solid oxide fuel cell is operated, and the process proceeds to process 1C. That is, the operation control apparatus C monitors the transition of the moving average value (that is, the transition of load energy) in the second setting period. In FIG. 2, the term “high power state continuation timer” is used to indicate a state in which the power load continues while being large.
On the other hand, the operation control device C determines that the solid oxide fuel cell 1 should be stopped if the moving average value is less than the second threshold (for example, 170 W), and proceeds to processing 1E. To do.

  Thus, in the present embodiment, the condition when shifting from the process 1E to the process 1F is whether or not the moving average value is 220 W or more, and the condition when shifting from the process 1F to the process 1E is The threshold is different, such as whether the moving average value is 170 W or more. This is to avoid the possibility that the processing frequently goes back and forth between the processing 1E and the processing 1F in accordance with a slight change in the moving average value when the same threshold value is set.

  As described above, the operation control device C is configured such that the period during which the solid oxide fuel cell 1 is operating continues for a predetermined lower limit operation period or longer, and the solid oxide fuel cell 1 is stopped. There is a constraint that allows a certain period to continue for a predetermined lower limit stop period or longer. That is, it can be avoided that the period during which the operation of the solid oxide fuel cell 1 continues and the period during which the stop continues are shortened. As a result, it is ensured that the operation and stop of the solid oxide fuel cell 1 are not repeated frequently. In addition, when the solid oxide fuel cell 1 is in operation, the operation control device C changes the system state quantity that is a function of the load energy to be supplied to the past load section L acquired during operation. Based on this, it is determined whether the solid oxide fuel cell 1 should be stopped or kept in operation. In addition, when the solid oxide fuel cell 1 is stopped, the operation control device C is based on the transition of the system state quantity that is a function of the load energy to be supplied to the past load portion L acquired during the stop. Thus, it is determined whether the solid oxide fuel cell 1 should be operated or should be stopped. That is, when the operation control device C refers to the transition of the system state quantity that is a function of the load energy to be supplied to the acquired past load unit L, the trend of the past load energy (for example, an increase trend, a decrease) That is, the operation control device C refers to a tendency, constant as it is large, constant as it is small, and the like. As a result, the operation control apparatus C preferably operates the solid oxide fuel cell 1 if the past load energy remains constant, for example, increasing or large, and the past load energy remains, for example, decreasing or small. The solid oxide fuel cell 1 tends to be operated in order to supply load energy, or the solid oxide fuel cell 1 tends to be operated. It can be determined whether the fuel cell 1 tends to be stopped. Accordingly, it is possible to provide a fuel cell system in which the solid oxide fuel cell 1 is operated and stopped at appropriate timing while avoiding frequent start and stop.

  In this embodiment, the example in which the first threshold value (220 W)> the second threshold value (170 W) is described, but the relationship between the first threshold value and the second threshold value is not limited to this example and can be changed as appropriate. .

Furthermore, in the present embodiment, the first threshold value (for example, 220 W), the first setting period (for example, 240 hours), the second threshold value (for example, 170 W), and the second setting period (for example, 24 hours) are constant values. Alternatively, it may be a variable value.
When the variable value is set, for example, the operation control device C increases the first threshold value as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. At least one of the change to the decrease side and the change to the increase side of the first setting period can be performed. Further, the operation control device C changes the second threshold value to the increasing side as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. And at least any one of the change to the increase side of a 2nd setting period can be performed.

  That is, when the first threshold value is changed to the decreasing side and the first setting period is changed to the increasing side, the solid oxide fuel cell 1 remains in operation at least in the process 1A. It becomes easy to determine that it should be. Similarly, when the change to the increase side of the second threshold is performed and when the change to the increase side of the second set period is performed, at least in the process 1F, the solid oxide fuel cell 1 is stopped. It becomes easy to determine that it should be left. As a result, since the frequency with which the solid oxide fuel cell 1 is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell 1 are hardly adversely affected.

  Furthermore, in this embodiment, the example which employ | adopted the period of 240 hours as a minimum driving | running period is shown, the example which employ | adopted the period of 240 hours as a minimum stop period is shown, and each moving average value is calculated by the moving average for 12 hours An example was given. That is, although the lower limit operation period (240 hours)> the moving average value calculation period (12 hours) and the lower limit stop period (240 hours)> the moving average value calculation period (12 hours) have been described, The magnitude relationship can be changed as appropriate.

Second Embodiment
The operation mode of the fuel cell system of the second embodiment is different from that of the above embodiment. The fuel cell system of the second embodiment will be described below, but the description of the same configuration as that of the above embodiment will be omitted.

FIG. 3 is a state transition diagram illustrating an operation mode of the fuel cell system according to the second embodiment.
Also in the present embodiment, the system state quantity is the load energy to be supplied from the solid oxide fuel cell 1 to the load unit L, and in particular, the power load to be supplied to the power load unit 3. Then, when the solid oxide fuel cell 1 is in operation, the operation control device C should stop or operate the solid oxide fuel cell 1 based on the transition of the past load energy during operation. When the solid oxide fuel cell 1 is stopped, the solid oxide fuel cell 1 should be operated based on the transition of the past load energy during the stop. Or whether it should remain stopped.

  Processes 2A, 2B, and 2C in FIG. 3 are processes performed when the solid oxide fuel cell 1 is in operation, and processes 2D, 2E, and 2F in FIG. This is a process that is performed when it is stopped. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.

〔driving〕
When the solid oxide fuel cell 1 is switched from the stopped state to the operating state, the operation control device C first continues the power generation for 240 hours in the processing 2C, and at the same time an operation time integrated value (low power state continuation counter described later). ) Is reset. In other words, the constraint condition is that the period during operation is continued for a predetermined lower limit operation period (240 hours or more). And operation control device C will shift to processing 2B, if 240 hours pass in processing 2C.

The operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. In operation 2B, the operation control apparatus C obtains, for example, a moving average value of load energy (average power load data for each hour) in the past predetermined period during operation (for example, continuous 12 hours) as 1 Derived every time, it is determined whether the moving average value is, for example, 170 W or more. And if the said moving average value is 170 W or more, the driving | operation control apparatus C will perform the countdown which reduces the integrated value at the time of driving | running | working used as a parameter | index by a regulation amount (for example, "1"). The integrated value during operation is not reduced below a predetermined minimum value (for example, zero). Then, the operation control device C continuously performs the determination of the process 2B. That is, the operation control device C counts down the integrated value during operation and continues the operation of the solid oxide fuel cell 1 while the moving average value is 170 W or more in the processing 2B performed every hour. . In FIG. 3, the term “low power state continuation counter” is used to indicate a state in which the integrated value at the time of operation indicates a state in which the power load is kept small.
On the other hand, if the moving average value derived every hour is less than 170 W, the operation control device C shifts to process 2A and performs a count-up that increases the accumulated value during operation by a specified amount. .

In the process 2A, if the moving average value derived every hour is less than 220 W, the operation control device C performs a count-up to increase the operation-time integrated value by a specified amount (for example, “1”). Then, the operation control device C determines that the solid oxide fuel cell 1 should remain in operation if the operation integration value is less than the upper limit operation integration value (for example, “240 counts”), and performs processing 2B. Continue. In the present embodiment, the process 2A is performed every hour and the specified amount to be increased or decreased is “1”. Therefore, in FIG. 3, “240 count” as the upper limit operation integrated value is “240 hours”. "Count". In the process 2A, if the moving average value is 220 W or more, the operation control device C performs a countdown to decrease the operation integrated value by a specified amount (for example, “1”) and shifts to the process 2B. .
On the other hand, in the process 2B, the operation control device C determines that the solid oxide fuel cell 1 should be stopped if the integrated value at the time of operation is the upper limit integrated value at the time of operation (for example, “240 count”). Transition to 2D.

  As described above, in the present embodiment, the operation control apparatus C derives a moving average value of the load energy in the past predetermined period (12 hours) during operation a plurality of times at every predetermined timing (every hour). On the other hand, if the moving average value is less than the third threshold value (220 W), the operating integrated value is increased by a specified amount, and if the moving average value is greater than or equal to the third threshold value (220 W), the operating integrated value is reduced to a predetermined minimum. If the accumulated value during operation is less than the upper limit accumulated value (240 counts), the solid oxide fuel cell 1 is left in operation if the accumulated value during operation is less than the upper limit accumulated value (240 counts). If the integrated value during operation is the upper limit integrated value during operation (240 counts), it is determined that the solid oxide fuel cell 1 should be stopped. That is, the operation control apparatus C monitors the transition of the moving average value (that is, the transition of load energy) using a method of counting up and counting down the integrated value during operation.

  Also in this embodiment, the condition when shifting from the process 2A to the process 2B is whether or not the moving average value is 220 W or more, and the condition when shifting from the process 2B to the process 2A is the moving average value. The threshold is different, such as whether or not is 170 W or more. This is to avoid the possibility that the processing frequently goes back and forth between the processing 2A and the processing 2B in accordance with the slight fluctuation of the moving average value when the same threshold value is set.

[Stopped]
When the solid oxide fuel cell 1 is switched from the operation state to the stop state, the operation control device C first continues the stop for 240 hours in the process 2D, and also adds an integrated value at the time of stop (high power state continuation counter described later). ) Is reset. That is, the constraint condition is that the period during the stop is continued for a predetermined lower limit stop period (240 hours or more). And operation control device C will shift to processing 2E, if 240 hours pass in processing 2D.

The operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. In operation 2E, the operation control apparatus C obtains, for example, a moving average value of load energy (average power load data for every hour) in a past predetermined period (for example, continuous 12 hours) during stoppage, for example, 1 Derived every time, it is determined whether the moving average value is less than 220W, for example. And if the said moving average value is less than 220W, the operation control apparatus C will perform the countdown which reduces the integrated value at the time of a stop used as a parameter | index by a defined amount (for example, "1"). The integrated value at the time of stop is not reduced below a predetermined minimum value (for example, zero). Then, the operation control device C continuously performs the determination of the process 2E. That is, the operation control device C counts down the integrated value at the time of stop and continues the stop of the solid oxide fuel cell 1 while the moving average value is less than 220 W in the processing 2E performed every hour. . In FIG. 3, the term “power high state continuation counter” is used to indicate a state where the integrated value at the time of stoppage is continued with a large power load.
On the other hand, if the moving average value derived every hour is 220 W or more, the operation control apparatus C counts up to increase the stop integrated value by a specified amount and shifts to the process 2F. .

In the process 2F, if the moving average value is 170 W or more, the operation control device C performs a count-up that increases the stop-time integrated value by a specified amount (for example, “1”). Then, the operation control apparatus C determines that the solid oxide fuel cell 1 should remain in operation if the integrated value at stop is less than the upper limit integrated value at stop (for example, “24 counts”), and processing 2F Continue. In the present embodiment, the processing 2F is performed every hour and the specified amount to be increased or decreased is “1”. Therefore, in FIG. 3, “24 counts” as the upper limit stop integrated value is “24 hours”. "Count". In the process 2F, if the moving average value is less than 170 W, the operation control device C performs a countdown to decrease the stop integrated value by a specified amount (for example, “1”) and shifts to the process 2E. .
On the other hand, in the process 2F, the operation control device C determines that the solid oxide fuel cell 1 should be operated if the stop-time integrated value is the upper limit stop-time integrated value (for example, “24 counts”). Move to 2C. That is, the operation control apparatus C monitors the transition of the moving average value (that is, the transition of load energy) using a method of counting up and counting down the integrated value at the time of stop.

  Thus, in the present embodiment, when the solid oxide fuel cell 1 is stopped, the moving average value of the load energy in the past predetermined period (12 hours) during the stop is calculated at predetermined timings (1 When the moving average value is equal to or greater than the fourth threshold value (170 W) while being derived a plurality of times every time), the stop integrated value is increased by a specified amount, and the moving average value is less than the fourth threshold value (170 W). If the integrated value at the time of stop is reduced by a specified amount on condition that the integrated value at stop is not reduced below a predetermined minimum value (zero), and the integrated value at stop is the upper limit integrated value at stop (24 counts), the solid oxide fuel cell 1 If the integrated value at the time of stop is less than the integrated value at the time of stop (24 counts), it is determined that the solid oxide fuel cell 1 should be stopped.

  Thus, also in this embodiment, the condition when shifting from the process 2E to the process 2F is whether or not the moving average value is 220 W or more, and the condition when shifting from the process 2F to the process 2E is The threshold is different, such as whether the moving average value is 170 W or more. This is to avoid the possibility that the processing frequently goes back and forth between the processing 2E and the processing 2F in accordance with slight fluctuations in the moving average value when the same threshold value is set.

  In this embodiment, an example in which the third threshold value (220 W)> the fourth threshold value (170 W) has been described, but the relationship between the third threshold value and the fourth threshold value is not limited to this example and can be changed as appropriate. .

Furthermore, in the present embodiment, the third threshold value (for example, 220 W), the upper limit operation integrated value (for example, 240 counts), the fourth threshold value (170 W), and the upper limit stop integrated value (for example, 24 counts) are constant values. Alternatively, it may be a variable value.
When the variable value is set, for example, the operation control device C increases the third threshold value as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. At least one of the change to the decrease side and the change to the increase side of the integrated value during the upper limit operation can be performed. Further, the operation control device C changes the fourth threshold value to the increasing side as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. And at least any one of the change to the increase side of the integrated value at the time of the upper limit stop can be performed.

  That is, when the third threshold value is changed to the decreasing side and the upper limit operation accumulated value is changed to the increasing side, at least in the process 2A, the solid oxide fuel cell 1 is being operated. It becomes easy to determine that it should be left. Similarly, when the fourth threshold value is changed to the increasing side and when the upper limit stop-time integrated value is changed to the increasing side, the solid oxide fuel cell 1 is stopped at least in the process 2F. It becomes easy to determine that it should be left. As a result, since the frequency with which the solid oxide fuel cell 1 is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell 1 are hardly adversely affected.

  Furthermore, in this embodiment, the example which employ | adopted the period of 240 hours as a minimum driving | running period is shown, the example which employ | adopted the period of 240 hours as a minimum stop period is shown, and each moving average value is calculated by the moving average for 12 hours An example was given. That is, although the lower limit operation period (240 hours)> the moving average value calculation period (12 hours) and the lower limit stop period (240 hours)> the moving average value calculation period (12 hours) have been described, The magnitude relationship can be changed as appropriate.

<Third Embodiment>
The fuel cell system of the third embodiment is different in operation mode from the above embodiment. The fuel cell system of the third embodiment will be described below, but the description of the same configuration as that of the above embodiment will be omitted.

FIG. 4 is a state transition diagram illustrating an operation mode of the fuel cell system according to the third embodiment.
Also in the present embodiment, the system state quantity is the load energy to be supplied from the solid oxide fuel cell 1 to the load unit L, and in particular, the power load to be supplied to the power load unit 3. Then, when the solid oxide fuel cell 1 is in operation, the operation control device C should stop or operate the solid oxide fuel cell 1 based on the transition of the past load energy during operation. When the solid oxide fuel cell 1 is stopped, the solid oxide fuel cell 1 should be operated based on the transition of the past load energy during the stop. Or whether it should remain stopped.

  Processes 3A, 3B, and 3C in FIG. 4 are processes performed when the solid oxide fuel cell 1 is in operation, and processes 3D, 3E, and 3F in FIG. This is a process that is performed when it is stopped. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.

〔driving〕
In the operation control device C, when the solid oxide fuel cell 1 is switched from the stopped state to the operating state, first, in the processing 3C, power generation is continued for 10 days. That is, the constraint condition is that the period during operation is continued for a predetermined lower limit operation period (above 10 days). And operation control device C will transfer to processing 3B, if 10 days pass in processing 3C.

The operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. Then, for example, when the date changes at midnight, the operation control device C obtains the total value of the load energy (average power load data for every hour) in the previous day during operation in process 3B. More than the total value of the load energy (average power load data for every hour) in one day before the previous day (that is, the load energy does not tend to increase or change), or a ninth threshold value (FIG. 4). In this example, if it is larger than “2.4 kWh”), the operation integrated value as an index is reset (set to a predetermined minimum value, for example, zero). Then, for example, every time the date changes at midnight, the operation control device C continues to perform the determination of the processing 3B. That is, the operation control device C is solid in the process 3B while the total value of the load energy in the previous day is greater than or equal to the total value of the load energy in the previous day or greater than 2.4 kWh. The operation of the oxide fuel cell 1 is continued. In FIG. 4, the term “power load decreasing tendency counter” is used to indicate that the integrated value during operation indicates a state in which the power load is decreasing.
On the other hand, in the process 3B, the operation control apparatus C has a total value of the load energy for one day the previous day smaller than the total value of the load energy for one day the previous day, and a ninth threshold value (FIG. In the example of “4”, “2.4 kWh”) or less, a count-up is performed to increase the integrated value during operation by a specified amount (for example, “1”) and the process proceeds to process 3A.

In the process 3A, for example, when the date is changed at midnight, the operation control device C has a total load energy value in the previous day that is less than or equal to the total load energy value in the previous day, If it is less than 10 thresholds (“3.6 kWh” in the example of FIG. 4), the operation-time integrated value (power load decreasing tendency counter) is incremented by a prescribed amount (eg, “1”). Then, the operation control device C determines that the solid oxide fuel cell 1 should remain in operation if the operation integrated value is less than the upper limit operation integrated value (for example, “10”), and performs the process 3B. continue. In the present embodiment, the process 3A is performed every day and the specified amount to be added is “1”. Therefore, in FIG. ". In the process 3A, the operation control device C determines that the total value of the load energy (average power load data for every hour) in the previous day during operation is equal to the load energy in the previous day. If it is larger than the total value of (average power load data per hour) (that is, the load energy tends to increase) and not less than the tenth threshold value (“3.6 kWh” in the example of FIG. 4), the above processing The process proceeds to 3B, and the accumulated value during operation is reset (set to a predetermined minimum value, for example, zero).
On the other hand, in the process 3A, the operation control device C determines that the solid oxide fuel cell 1 should be stopped if the integrated value at the time of operation is the upper limit integrated value at the time of operation (for example, “10 counts”). Move to 3D. That is, the operation control apparatus C monitors the transition of load energy between the day before and the day before.

  In the processing 3A, when the load energy between the previous day and the previous day has changed only slightly, the operation-time integrated value (power load decrease tendency counter) is maintained as it is (that is, the count-up is performed). (No counting down). For example, if the difference between the total value of the load energy in the previous day and the total value of the load energy in the previous day is within a predetermined difference in the above processing 3A, It may be considered that the load is neither decreasing nor increasing, and the integrated value during operation (power load decreasing tendency counter) is maintained as it is (that is, the counter is not counted up and not counted down).

[Stopped]
When the solid oxide fuel cell 1 is switched from the operation state to the stop state, the operation control device C first stops for two days in the process 3D. That is, the restriction condition is that the period during the stop is continued for a predetermined lower limit stop period (above two days). And operation control device C will shift to processing 3E, if two days pass in processing 3D.

The operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. Then, for example, when the date changes at midnight, the operation control device C obtains a total value of load energy (average power load data for every hour) in the previous day during the stop in process 3E. Or less than the total value of the load energies (average power load data for every hour) in the previous day, or the eleventh threshold value (FIG. 4). If it is smaller than "3.6 kWh"), the stop integrated value is reset (set to a predetermined minimum value, for example, zero). Then, for example, every time the date changes at midnight, the operation control device C continues to perform the determination of the processing 3E. That is, the operation control apparatus C is solid in the process 3E while the total value of the load energy in the previous day is less than or equal to the total value of the load energy in the previous day or less than 3.6 kWh. The stop of the oxide fuel cell 1 is continued. In FIG. 4, the term “power load increase tendency counter” is used to indicate that the integrated value at the time of stop indicates a state where the power load tends to increase.
On the other hand, in the process 3E, the operation control device C has a total value of the load energy in the previous day of the previous day larger than the total value of the load energy in the previous day of the previous day, and an eleventh threshold value ( In the example of FIG. 4, if it is “3.6 kWh”) or more, count-up is performed to increase the stop integrated value by a specified amount (for example, “1”), and the process proceeds to process 3F.

In the process 3F, for example, when the date changes at midnight, the operation control device C has a total value of the load energy in the previous day of the previous day equal to or greater than the total value of the load energy in the previous day, or If it is greater than the twelfth threshold value (“2.4 kWh” in the example of FIG. 4), count-up is performed to increase the stop-time integrated value (power load increase tendency counter) by a prescribed amount (eg, “1”). Then, the operation control device C determines that the solid oxide fuel cell 1 should be stopped if the stop-time integrated value is less than the upper limit stop-time integrated value (for example, “3”), and performs the process 3F. continue. In the present embodiment, the process 3F is performed every day and the specified amount to be added is “1”. Therefore, in FIG. 4, “3 counts” as the integrated value at the upper limit stop time is “3 days”. "Count". In the process 3F, the operation control device C determines that the total load energy (average power load data for every hour) in the previous day during the stop is equal to the load energy in the previous day ( If it is less than the total value of the average power load data for every hour) and less than or equal to the twelfth threshold value (“2.4 kWh” in the example of FIG. 4), the process proceeds to the process 3E and at the time of the stop. The integrated value is reset (set to a predetermined minimum value, for example, zero).
On the other hand, in the process 3F, the operation control device C determines that the solid oxide fuel cell 1 should be operated if the stop integrated value is the upper limit stop integrated value (for example, “3 counts”). Move to 3C. That is, the operation control apparatus C monitors the transition of load energy between the day before and the day before.

  In the process 3F, if the load energy between the previous day and the previous day has changed only slightly, the stop integrated value (power load increase tendency counter) is maintained as it is (that is, count-up is performed). (No counting down). For example, if the difference between the total value of the load energy in the previous day and the total value of the load energy in the previous day is within a predetermined difference in the processing 3F, the operation control device C Assuming that the load is neither decreasing nor increasing, the stop integrated value (power load increasing tendency counter) may be maintained as it is (that is, the counter is not counted up and not counted down).

<Fourth embodiment>
The fuel cell system of the fourth embodiment is different from the above embodiment in its operation mode. Although the fuel cell system of 4th Embodiment is demonstrated below, description is abbreviate | omitted about the structure similar to the said embodiment.

FIG. 5 is a state transition diagram illustrating an operation mode of the fuel cell system according to the fourth embodiment.
In the present embodiment, the system state quantity is load energy to be supplied from the solid oxide fuel cell 1 to the load portion L, and in particular, is a heat load (hot water supply load) to be supplied to the heat load portion 4. Then, when the solid oxide fuel cell 1 is in operation, the operation control device C should stop or operate the solid oxide fuel cell 1 based on the transition of the past load energy during operation. When the solid oxide fuel cell 1 is stopped, the solid oxide fuel cell 1 should be operated based on the transition of the past load energy during the stop. Or whether it should remain stopped.

  Processes 4A, 4B, and 4C in FIG. 5 are processes performed when the solid oxide fuel cell 1 is in operation, and processes 4D, 4E, and 4F in FIG. This is a process that is performed when it is stopped. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.

〔driving〕
In the operation control device C, when the solid oxide fuel cell 1 is switched from the stopped state to the operating state, first, in the process 4C, power generation is continued for 10 days. That is, the constraint condition is that the period during operation is continued for a predetermined lower limit operation period (above 10 days). And operation control device C will shift to processing 4B, if 10 days pass in processing 4C.

The operation control device C continuously acquires and stores data on the daily hot water supply load at the heat load unit 4. Then, in the process 4B, for example, when the date changes at midnight, the operation control device C has a load energy (hot water supply load) in the past one day during operation that is greater than or equal to the second reference value (10 (MJ)). (That is, whether the load energy is in a relatively large state). Then, when the load energy (hot water supply load) in the past one day during operation is equal to or higher than the second reference value (10 (MJ)), the operation control device C resets the operation integrated value as an index. (Set to a predetermined minimum value, eg zero). Then, for example, every time the date changes at midnight, the operation control device C continuously performs the determination of the process 4B. That is, in the process 4B, the operation control device C is a solid oxide fuel cell as long as the load energy (hot water supply load) in the past one day during operation is equal to or greater than the second reference value (10 (MJ)). Continue the operation of 1. In FIG. 5, the term “hot water supply load low state continuation counter” is used to indicate a state in which the integrated value during operation indicates that the hot water supply load is kept small.
On the other hand, when the load energy (hot water supply load) in one day during operation is less than the second reference value (10 (MJ)) in operation 4B, the operation control device C performs the above operation time integration. The count is incremented to increase the value by a specified amount (for example, “1”), and the process proceeds to process 4A.

In the process 4A, for example, when the date changes at midnight, the operation control apparatus C is less than the first reference value (15 (MJ)) if the load energy (hot water supply load) in the past one day during operation is less than the first reference value (15 (MJ)). Then, a count-up is performed to increase the above operating integrated value (hot water supply load low state continuation counter) by a prescribed amount (eg, “1”). Then, the operation control device C determines that the solid oxide fuel cell 1 should remain in operation if the operation integrated value is less than the upper limit operation integrated value (for example, “10”), and performs the process 4B. continue. In the present embodiment, the process 4A is performed every day and the specified amount to be added is “1”. Therefore, in FIG. 5, “10 counts” as the upper limit operation integrated value is “10 day counts”. ". In the process 4A, the operation control device C shifts to the process 4B if the load energy (hot water supply load) in one day during operation is not less than the first reference value (15 (MJ)), and The accumulated value during operation is reset (set to a predetermined minimum value, for example, zero).
On the other hand, in the process 4A, the operation control device C determines that the solid oxide fuel cell 1 should be stopped if the integrated value at the time of operation is the upper limit integrated value at the time of operation (for example, “10 counts”). Move to 4D. That is, the operation control apparatus C monitors the transition of load energy (hot water supply load) using a method of counting up and resetting the integrated value during operation.

[Stopped]
When the solid oxide fuel cell 1 is switched from the operation state to the stop state, the operation control device C first stops for two days in the process 4D. That is, the restriction condition is that the period during the stop is continued for a predetermined lower limit stop period (above two days). And operation control device C will shift to processing 4E, if two days pass in processing 4D.

In the process 4E, for example, when the date changes at midnight, the operation control device C has a load energy (hot water supply load) in the past one day during the stoppage that is less than the first reference value (15 (MJ)). (That is, whether the load energy is relatively small). And if the load energy (hot-water supply load) in the past one day during a stop is less than a 1st reference value (15 (MJ)), the operation control apparatus C will reset the integrated value at the time of a stop. (Set to a predetermined minimum value, eg zero). Then, for example, every time the date changes at midnight, the operation control device C continues to perform the determination of the process 4E. That is, the operation control apparatus C is in the solid oxide fuel cell 1 while the load energy (hot water supply load) in the past one day during the process 4E is less than the first reference value (15 (MJ)). Continue to stop. In FIG. 5, the term “hot water supply load large state continuation counter” is used to indicate the state where the integrated value at the time of stoppage is continued while the hot water supply load is large.
On the other hand, if the load energy (hot water supply load) in one day during the stop is equal to or greater than the first reference value (15 (MJ)) in the process 4E, the operation control device C is the integrated value at the time of stop. Is incremented by a specified amount and the process proceeds to process 4F.

In the process 4F, for example, when the date changes at midnight, the operation control device C has a load energy (hot water supply load) for one day during the stoppage that is equal to or greater than the second reference value (10 (MJ)). Count-up is performed to increase the stop-time integrated value (hot water supply load large state continuation counter) by a specified amount (for example, “1”). Then, the operation control device C determines that the solid oxide fuel cell 1 should be stopped when the stop integrated value is less than the upper limit stop integrated value (for example, “3”), and performs the process 4F. continue. In this embodiment, the process 4F is performed every day and the specified amount to be added is “1”. Therefore, in FIG. 5, “3 counts” as the integrated value at the time of the upper limit stop is “3 days”. "Count". In the process 4F, the operation control device C shifts to the process 4E if the load energy (hot water supply load) in the past one day during the stop is less than the second reference value (10 (MJ)). The stop integrated value is reset (set to a predetermined minimum value, for example, zero).
On the other hand, in the process 4F, the operation control device C determines that the solid oxide fuel cell 1 should be operated if the stop integrated value is the upper limit stop integrated value ("3" above), and the process 4C. Migrate to That is, the operation control device C monitors the transition of the load energy (hot water supply load) by using a method of counting up and resetting the stop integrated value.

<Fifth Embodiment>
The fuel cell system of the fifth embodiment is different in operation mode from the above embodiment. The fuel cell system of the fifth embodiment will be described below, but the description of the same configuration as that of the above embodiment will be omitted.

FIG. 6 is a state transition diagram illustrating an operation mode of the fuel cell system according to the fifth embodiment.
Also in this embodiment, the system state quantity is the load energy to be supplied from the solid oxide fuel cell 1 to the load L, and in particular, the heat load energy to be supplied to the heat load 4 and the power load 3 to be supplied. It is the power load energy to be done. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.

〔driving〕
As long as the operation control device C continues to be in a state where no heat load energy is generated in the heat load unit 4 and there is no operation input to the remote controller (information input / output device 18) in the process 5A, the operation control device C automatically Counts up the absence stop timer. When the count of the automatic absence stop timer reaches 240 hours, it is determined that the solid oxide fuel cell 1 should be stopped, the solid oxide fuel cell is stopped, and the process proceeds to processing 5C. The operation control device C performs processing 5B when heat load energy is generated in the heat load unit 4 during operation 5A or when there is an operation input to the remote controller (information input / output device 18). Then, the count of the automatic absence stop timer is reset (i.e., set to zero), and when the reset of the count is completed, the process returns to the process 5A.

Further, the operation control device C continuously acquires and stores data on average power load every hour in the power load unit 3. Then, the operation control device C determines whether or not the average power load for the most recent hour during operation is less than 220 W, for example, in the process 5F. If the average power load for the most recent hour is less than 220 W, the small power timer is counted up. Then, when the count of the small power timer reaches 240 hours, it is determined that the solid oxide fuel cell 1 should be stopped, and the solid oxide fuel cell 1 is stopped and the process proceeds to processing 5I. If the average power load for the most recent hour is 220 W or more during the process 5F, the operation control device C shifts to process 5G and resets the count of the small power timer (that is, zero). To do). Then, in the process 5G, the process 5G is continued as long as the average power load for the most recent hour is 170 W or more. That is, the operation control device C continues the operation of the solid oxide fuel cell 1 while the average power load for the most recent one hour in the process 5G is 170 W or more. On the other hand, when the average power load for the most recent one hour is less than 170 W in the process 5G, the operation control device C shifts to the process 5F and counts up the count of the small power timer.
In operation 5H, when the operation of the solid oxide fuel cell 1 is started, the operation control device C first masks the count of the small power timer, for example, for 240 hours, and restricts the continuous operation at least during that time. As a condition.

  As described above, when the solid oxide fuel cell 1 is in operation, the operation control apparatus C determines that the transition of the past heat load energy during operation is the first operation stop condition (the heat load portion in the past 240 hours). No change in heat load energy in 4 and no remote control operation, etc., or transition of past power load energy during operation is the second operation stop condition (past 240 hours, average load power per hour is less than 220 W) ) Is satisfied, it is determined that the solid oxide fuel cell 1 should be stopped. If neither the first operation stop condition nor the second operation stop condition is satisfied, the solid oxide fuel cell 1 is left in operation. Judge that it should be.

[Stopped]
In the process 5C, when the solid oxide fuel cell 1 is stopped for 24 hours, the operation control device C resets the count of the automatic absence stop timer and waits as it is. Then, the operation control device C shifts to processing 5D when there is generation of heat load energy in the heat load unit 4 or when there is an operation input to the remote controller (information input / output device 18) during the standby. That is, the operation control device C waits as long as no heat load energy is generated in the heat load unit 4 or no operation input to the remote controller (information input / output device 18) continues in the process 5C. Therefore, the stop is continued for at least 24 hours, and the stop may be longer than that.

  In the process 5D, the operation control device C continuously acquires and stores the data of the average power load for each hour in the power load unit 3, and the past predetermined period during the stop (example shown in FIG. 6). Then, if the moving average value of the power load (average power load data for every hour) in continuous 24 hours is 220 W or more, for example, it is determined that the operation should be started, and the process proceeds to processing 5E. Then, the operation control device C operates the solid oxide fuel cell 1 after resetting the count of the small power timer in the process 5E.

  Further, the operation control device C resets the count of the small power timer when the solid oxide fuel cell 1 is stopped for 24 hours in the process 5I. Then, similarly to the above-described processing 5D, the operation control device C determines the power load (average power load data for every hour) in the past predetermined period of stoppage (24 hours in the example shown in FIG. 6). If the moving average value of) is 220 W or more, for example, it is determined that the operation should be started, and the process proceeds to Process 5J. In operation 5J, the operation control device C operates the solid oxide fuel cell 1 after resetting the count of the automatic absence stop timer.

  Further, the operation control device C is instructed to operate the solid oxide fuel cell 1 in the forced power generation mode by an operation input to the remote controller (information input / output device 18) while the solid oxide fuel cell 1 is stopped. The solid oxide fuel cell 1 is operated regardless of the above conditions. In addition, the operation control device C, while operating the solid oxide fuel cell 1, as long as the operation in the forced power generation mode of the solid oxide fuel cell 1 is commanded by an operation input to the information input / output device 18, The solid oxide fuel cell 1 is continuously operated regardless of the above conditions.

  As described above, in the operation control device C, the solid oxide fuel cell 1 satisfies the first operation stop condition (no generation of heat load energy in the heat load unit 4 and no remote control operation in the past 240 hours). The transition of the past heat load energy and the transition of the power load energy during the stop is the first operation start condition (such as the occurrence of heat load energy or remote control operation, etc. When the moving average value of the power load (average power load data for each hour) in the period (24 hours in the example shown in FIG. 6 is 220 W or more) is satisfied, the solid oxide fuel cell 1 is operated. If the first operation start condition is not satisfied, it is determined that the solid oxide fuel cell 1 should be stopped, and the solid oxide fuel cell 1 is in the second operation stop condition ( Past 2 When the vehicle is stopped due to the fact that the average load power every hour for 1 hour is less than 220 W, the transition of the past power load energy during the stop is the second operation start condition (past predetermined period (Fig. In the example shown in FIG. 6, it is determined that the solid oxide fuel cell 1 should be operated when the moving average value of the power load (average power load data for each hour) in continuous 24 hours is 220 W or more. If the second operation start condition is not satisfied, it is determined that the solid oxide fuel cell 1 should remain stopped.

<Sixth Embodiment>
The fuel cell system of the sixth embodiment is different from the above embodiment in its operation mode. Although the fuel cell system of 6th Embodiment is demonstrated below, description is abbreviate | omitted about the structure similar to the said embodiment.

FIG. 7 is a flowchart for explaining an operation mode of the fuel cell system according to the sixth embodiment.
In the present embodiment, the system state quantity is load energy to be supplied from the solid oxide fuel cell 1 to the load portion L, and in particular, is a power load to be supplied to the power load portion 3.
When the solid oxide fuel cell 1 is in operation, the operation control device C derives a predicted value of the future load energy based on the transition of the past load energy, and if the predicted value is greater than or equal to the fifth threshold value. In other words, it is determined that the solid oxide fuel cell 1 should remain in operation, and if the predicted value is less than the fifth threshold, it is determined that the solid oxide fuel cell 1 should be stopped, and the solid oxide fuel cell When the battery 1 is stopped, a predicted value of the future load energy is derived based on the transition of the past load energy, and the solid oxide fuel cell 1 is operated if the predicted value is the sixth threshold value or more. If the predicted value is less than the sixth threshold, it is determined that the solid oxide fuel cell 1 should be stopped.

  Specifically, the operation control apparatus C continuously acquires and stores data on average power load every hour in the power load unit 3. Then, the operation control apparatus C performs the process shown in the flowchart of FIG. 7 once at a predetermined timing of the day (for example, when the date changes at midnight), and the solid oxide fuel cell 1 It is determined whether the vehicle should be driven or stopped. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.

  In Step # 10, the operation control device C determines the total power load (in this embodiment, the average power load for every hour) in the power load unit 3 for one day the previous day (24 hours from 0:00 to 24:00). Derived). Further, since the operation control device C continuously derives and stores the total power load in the power load unit 3 for one day before the previous day, it also stores data of each total power load for the past 30 days. ing. In step # 11, the operation control apparatus C approximates the transition of each total power load for the past 30 days with a linear function using the least square method. That is, the linear function derived in the process # 20 indicates the tendency of the power load in the power load unit 3 for the past 30 days. In step # 12, the operation control apparatus C predicts the total power load for the next day using the approximated linear function.

  Next, in step # 13, the operation control device C determines whether the solid oxide fuel cell 1 is currently operating or stopped. The operation control device C proceeds to step # 14 when operating (in the case of “Yes” in step # 13), and proceeds to step # 14 in the case of being stopped (in the case of “No” in step # 13). Move to # 17.

  In Step # 14, the operation control apparatus C determines whether or not the next day's total power load (predicted value) derived in Step # 12 is less than a predetermined stop threshold (the fifth threshold). That is, in step # 14, the solid oxide fuel cell 1 is currently in operation, but the power load predicted on the next day is in a small state, that is, the solid oxide fuel cell 1 is stopped. It is determined whether it is appropriate. When the total power load on the next day predicted in step # 12 is less than the predetermined stop threshold value (the fifth threshold value), the operation control device C proceeds to step # 15 and the solid oxide fuel cell 1 Determine that it should be stopped. In contrast, when the total power load on the next day predicted in step # 12 is equal to or greater than a predetermined stop threshold value (the fifth threshold value), the operation control device C proceeds to step # 16 and proceeds to solid oxide fuel. It is determined that the battery 1 should continue operation.

  In Step # 17, the operation control device C determines whether or not the next day's total power load (predicted value) derived in Step # 12 is equal to or greater than a predetermined operation threshold (the sixth threshold). That is, in step # 17, the solid oxide fuel cell 1 is currently stopped, but the power load predicted on the next day is in a large state, that is, the solid oxide fuel cell 1 is operated. It is determined whether it is appropriate. Then, when the total power load on the next day predicted in step # 12 is equal to or greater than a predetermined operation threshold (the sixth threshold), the operation control device C proceeds to step # 18 and the solid oxide fuel cell 1 Determine that you should drive. On the other hand, when the total power load on the next day predicted in step # 12 is less than a predetermined operation threshold value (the sixth threshold value), the operation control device C proceeds to step # 19 and proceeds to solid oxide fuel. It is determined that the battery 1 should continue to be stopped.

  The relationship between the fifth threshold value and the sixth threshold value can be set as appropriate. For example, setting each to a value that satisfies the relationship of the fifth threshold = the sixth threshold, setting each to a value that satisfies the relationship of the fifth threshold> the sixth threshold, and the fifth threshold < Each can be set to a value that satisfies the relationship of the sixth threshold.

Furthermore, in the present embodiment, the fifth threshold value and the sixth threshold value described above may be constant values or variable values.
When the variable value is set, for example, the operation control device C increases the fifth threshold value as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. Can be changed to the decreasing side. Further, the operation control device C changes the sixth threshold value to the increasing side as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. It can be performed.

  That is, when the fifth threshold value is changed to the decreasing side, it is easy to determine in step # 14 that the solid oxide fuel cell 1 should remain in operation. Similarly, when the sixth threshold value is changed to the increase side, it is easy to determine in step # 17 that the solid oxide fuel cell 1 should remain stopped. As a result, since the frequency with which the solid oxide fuel cell 1 is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell 1 are hardly adversely affected.

<Seventh embodiment>
The fuel cell system of the seventh embodiment is different from the above embodiment in its operation mode. The fuel cell system according to the seventh embodiment will be described below, but the description of the same configuration as the above embodiment will be omitted.

FIG. 8 is a flowchart for explaining an operation mode of the fuel cell system according to the seventh embodiment. In the following example, the operation mode of the fuel cell system of the present embodiment is described with specific numerical values, but these numerical values can be changed as appropriate.
In the present embodiment, the system state quantity is a consumption primary energy reduction quantity, an energy cost reduction quantity or an emission carbon dioxide reduction quantity obtained when the load energy to be supplied to the load section L is supplied from the solid oxide fuel cell 1. Or a driving merit that is a linear combination of any two or three of them.

  When the solid oxide fuel cell 1 is in operation, the operation control device C is configured to supply load energy from the solid oxide fuel cell 1 within a predetermined period (for example, 30 days) during operation. Deriving the actual value of the operating merit, if the actual value is greater than or equal to the seventh threshold (“zero” in the following example), it is determined that the solid oxide fuel cell 1 should remain in operation, and the actual value Is less than the seventh threshold value, it is determined that the solid oxide fuel cell 1 should be stopped. When the solid oxide fuel cell 1 is stopped, the past predetermined period (for example, 30 days) during the stop The predicted value of the operating merit when it is assumed that the load energy is supplied from the solid oxide fuel cell 1 is derived, and if the predicted value is equal to or greater than the eighth threshold (“zero” in the following example), the solid It is determined that the oxide fuel cell 1 should be operated, and the predicted value Determined that should the if it is less than the eighth threshold value a solid oxide fuel cell 1 remains stopped.

  First, the driving merit will be described. The operating merit is that the primary energy reduction amount or energy cost reduction amount or emission carbon dioxide reduction amount obtained when the load energy to be supplied to the load portion L is supplied from the solid oxide fuel cell 1, or among them, Any two or three of the linear combinations. As described below, the consumed primary energy reduction amount, the energy cost reduction amount, and the emission carbon dioxide reduction amount are derived as a function of the load energy to be supplied to the load unit L.

  The consumption primary energy reduction amount is a consumption primary energy amount that can be reduced by operating the solid oxide fuel cell 1. That is, in order to supply load energy to the load part L from the amount of primary energy consumed when the solid oxide fuel cell 1 is not operated to supply load energy to the load part L, solid oxide fuel cell It is obtained by subtracting the amount of primary energy consumed when 1 is operated.

The amount of primary energy consumed when the solid oxide fuel cell 1 is operated to supply load energy to the load L is supplied from the solid oxide fuel cell 1 as a daily power load and heat load. The amount of primary energy consumed by the solid oxide fuel cell 1 when it is operated to the maximum extent with the power and heat generated, and the amount of primary energy consumed by the commercial power source 15 when the insufficient power is received from the commercial power source 15; This is the sum of the amount of primary energy consumed by the auxiliary heat source device 11 when insufficient heat is received from the auxiliary heat source device 11.
The amount of primary energy consumed when the solid oxide fuel cell 1 is not operated in order to supply load energy to the load L is the commercial power source 15 when all of the daily power load is received from the commercial power source 15. Is the sum of the consumed primary energy amount of the auxiliary heat source device 11 when all of the daily heat load is received from the auxiliary heat source device 11.

  The operation control device C uses the stored power generation efficiency value and exhaust heat efficiency value of the solid oxide fuel cell 1 to generate the primary energy consumption of the solid oxide fuel cell 1 required for supplying power by power generation, and to generate power. The amount of primary heat consumed by the commercial power source 15 required when the power plant supplies power, the stored auxiliary heat source, based on the amount of exhaust heat discharged along with the power generation efficiency value of the stored power plant (commercial power source 15) Based on the efficiency value of the device 11, the primary energy consumption of the auxiliary heat source device 11 required when supplying heat is calculated, and the primary energy reduction amount is derived with reference to those values.

The energy cost reduction amount is an energy cost that can be reduced by operating the solid oxide fuel cell 1. The energy cost reduction amount is calculated from the energy cost when the solid oxide fuel cell 1 is not operated to supply the load energy to the load portion L in the same manner as described above with respect to the primary energy consumption reduction amount. It is obtained by subtracting the energy cost when the solid oxide fuel cell 1 is operated to supply load energy to L.
The operation control device C uses the stored power generation efficiency value and exhaust heat efficiency value of the solid oxide fuel cell 1, the power generation efficiency value of the power plant, and the efficiency value of the auxiliary heat source device 11 to determine the respective fuel consumption and commercial power supply. The amount of energy cost reduction is derived based on the unit price of fuel consumed by the solid oxide fuel cell 1 and the auxiliary heat source device 11 and the unit price of power of the commercial power supply 15.

The emission carbon dioxide reduction amount is the amount of emission carbon dioxide that can be reduced by operating the solid oxide fuel cell 1. The amount of carbon dioxide emission reduced is the amount of carbon dioxide emitted when the solid oxide fuel cell 1 is not operated to supply load energy to the load portion L, as described above with respect to the amount of primary energy consumption consumed. It is obtained by subtracting the amount of carbon dioxide emitted when the solid oxide fuel cell 1 is operated in order to supply load energy to the load section L.
The operation control device C obtains the respective fuel consumption and purchase amount from the commercial power supply 15 based on the stored power generation efficiency value and exhaust heat efficiency value of the solid oxide fuel cell 1 and the efficiency value of the auxiliary heat source device 11. Based on the stored solid oxide fuel cell 1 and the auxiliary carbon dioxide emission unit of fuel consumed by the auxiliary heat source device 11 and the basic unit of carbon dioxide emission of the commercial power supply 15, the emission carbon dioxide reduction amount is derived. To do.

  Then, the operation control apparatus C performs the process shown in the flowchart of FIG. 7 once at a predetermined timing of the day (for example, when the date changes at midnight), and the solid oxide fuel cell 1 It is determined whether the vehicle should be driven or stopped.

  In step # 20, the operation control apparatus C derives the operation merit for one day on the previous day (24 hours from time 0:00 to time 24:00). In addition, since the operation control apparatus C continuously derives and stores driving merit for one day before the previous day, it also stores data of each driving merit for the past 30 days. And in process # 21, operation control device C derives the total operation merit for the past 30 days. That is, the operation control apparatus C monitors the transition of the load energy by using a method of referring to the total value of the operation merits derived as a function of the load energy to be supplied to the load unit L in the past 30 days.

  Next, in step # 22, the operation control device C determines whether the solid oxide fuel cell 1 is currently operating or stopped. The operation control device C proceeds to step # 23 when operating (in the case of “Yes” in step # 22), and proceeds to step # 23 in the case of being stopped (in the case of “No” in step # 22). Move to # 26.

  In step # 23, the operation control apparatus C determines whether or not the actual value of the total operation merit for the past 30 days during operation of the solid oxide fuel cell 1 is a negative value ("zero" as the seventh threshold value). Or less). And if the performance value of a total driving | operation merit is a negative value (less than zero (7th threshold value)), the operation control apparatus C will determine that it should transfer to process # 24 and should stop the solid oxide fuel cell 1 To do. In contrast, if the actual operation merit value is zero (seventh threshold) or more, the operation control device C proceeds to step # 25 and keeps the solid oxide fuel cell 1 in operation. Judge that it should be.

  In Step # 26, the operation control apparatus C determines whether or not the predicted value of the total operation merit for the past 30 days when the solid oxide fuel cell 1 is stopped is a negative value (the eighth threshold value is “ Whether it is less than "zero"). Then, if the predicted value of the total operation merit is a negative value (less than zero (eighth threshold)), the operation control device C proceeds to step # 28 and keeps the solid oxide fuel cell 1 being stopped. Determine that you should. On the other hand, if the predicted value of the total operation merit is zero (eighth threshold) or more, the operation control device C determines that the solid oxide fuel cell 1 should be operated by moving to step # 27. .

  In the present embodiment, the example in which both the seventh threshold value and the eighth threshold value are zero has been described. However, the seventh threshold value and the eighth threshold value are not limited to this example and can be changed as appropriate. For example, each can be set to a value that satisfies the relationship of the seventh threshold value> the eighth threshold value, and each can be set to a value that satisfies the relationship of the seventh threshold value <the eighth threshold value.

Furthermore, in the present embodiment, the seventh threshold value and the eighth threshold value described above may be constant values or variable values.
When the variable value is set, for example, the operation control device C increases the seventh threshold value as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. Can be changed to the decreasing side. Further, the operation control device C changes the eighth threshold value to the increasing side as the number of times the solid oxide fuel cell 1 is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell 1 is switched from the stopped state to the operating state increases. It can be performed.

  That is, when the seventh threshold value is changed to the decreasing side, it is easy to determine in step # 23 that the solid oxide fuel cell 1 should remain in operation. Similarly, when the eighth threshold value is changed to the increase side, it is easy to determine in step # 26 that the solid oxide fuel cell 1 should remain stopped. As a result, since the frequency with which the solid oxide fuel cell 1 is switched between the operating state and the stopped state becomes lower, the durability and reliability of the solid oxide fuel cell 1 are hardly adversely affected.

<Another embodiment>
<1>
In the above embodiment, the configuration of the fuel cell system has been described with a specific example, but the configuration can be changed as appropriate.
For example, a fuel cell system that does not include the radiator 8 may be used.
Moreover, although the auxiliary heat source device 11 of the type that generates heat by burning fuel is illustrated in the above embodiment, an electric auxiliary heat source device that generates Joule heat may be employed. In that case, the auxiliary heat source device becomes one of the device groups constituting the power load unit 3.

<2>
In the above-described embodiment, load energy, operation merit, and the like are exemplified as system state quantities. However, other values can be used as system state quantities as long as they represent values indicating the operating state of the fuel cell system.

<3>
Further, in the seventh embodiment, an example has been described in which each value of primary energy consumption, energy cost, and amount of discharged carbon dioxide is easily obtained from each efficiency value, each unit price, basic unit, and the like. In accordance with the above, heat dissipation and loss generated in each part may be set to obtain precisely.

  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 (SOFC)
3 Power load section 4 Thermal load section C Operation control device L Load section

Claims (15)

A fuel cell system comprising a solid oxide fuel cell that supplies energy generated by operation to a load unit, and an operation control device that controls the operation of the solid oxide fuel cell,
The operation control device includes:
When said solid oxide fuel cell is in operation, while the constraint condition that causes its duration is operating above a predetermined lower operating period continuously, the load of the past acquired during the operation Determining whether the solid oxide fuel cell should be shut down or left in operation based on the transition of the system state quantity as a function of the load energy to be supplied;
When said solid oxide fuel cell is stopped, while a constraint condition that is continuous its period greater than a predetermined lower limit stop period is stopped, the load of the past acquired during the stop A fuel cell system that determines whether the solid oxide fuel cell should be operated or kept stopped based on a transition of a system state quantity that is a function of load energy to be supplied. The system state quantity is load energy to be supplied to the load unit,
The operation control device includes:
When said solid oxide fuel cell is in operation, on the basis of transition of the past of the load energy in its operation, to leave the solid oxide fuel or during operation to stop battery Determine whether
When the solid oxide fuel cell is stopped, should the on the basis of transition of the past of the load energy in the stopped, leaving the solid oxide or stopped to be operated fuel cell The fuel cell system according to claim 1, wherein the determination is made. The operation control device includes:
When said solid oxide fuel cell is in operation, to derive the moving average value of the load energy in past predetermined period in the operation at every predetermined timing, the moving average value is the first threshold value If it is above, it is determined that the solid oxide fuel cell should remain in operation, and if the moving average value is continuously less than the first threshold for a first set period or longer, the solid oxide fuel cell Determine that the battery should be stopped,
When the solid oxide fuel cell is stopped, the moving average value of the load energy in the past predetermined period during the stopping is derived for each predetermined timing, and the moving average value is set to the second setting. It is determined that the solid oxide fuel cell should be operated if it is continuously greater than or equal to the second threshold for a period or more, and the solid oxide fuel cell is stopped if the moving average value is less than the second threshold The fuel cell system according to claim 2, wherein it is determined that it should be left as it is.   As the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases, the operation control device changes the first threshold value to the decreasing side and The fuel cell system according to claim 3, wherein at least one of the change to the increase side of the first setting period is performed.   As the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases, the operation control device changes the second threshold value to the increase side and The fuel cell system according to claim 3 or 4, wherein at least one of the second setting period is changed to an increase side. The operation control device includes:
When the solid oxide fuel cell is in operation, the moving average value is derived several times for each predetermined timing while the moving average value of the load energy in the past predetermined period during the operation is derived. The specified amount is obtained under the condition that the operating integrated value is increased by a specified amount if it is less than the third threshold, and the operating integrated value is not decreased below a predetermined minimum value if the moving average value is greater than or equal to the third threshold. If the integrated value during operation is less than the integrated value during upper limit operation, it is determined that the solid oxide fuel cell should remain in operation, and the integrated value during operation is the integrated value during upper limit operation If so, it is determined that the solid oxide fuel cell should be stopped,
When the solid oxide fuel cell is stopped, while derived several times the moving average of the load energy in a predetermined past period at its stopped at every predetermined timing, the moving average value The specified amount on condition that the stop integrated value is increased by a specified amount if it is greater than or equal to the fourth threshold, and the stop integrated value is not decreased below a predetermined minimum value if the moving average value is less than the fourth threshold. It is determined that the solid oxide fuel cell should be operated if the integrated value at the time of stop is an integrated value at the time of the upper limit stop, and if the integrated value at stop is less than the integrated value at the time of upper limit stop, the The fuel cell system according to claim 2, wherein it is determined that the solid oxide fuel cell should be stopped.   As the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases, the operation control device changes the third threshold value to the decreasing side and The fuel cell system according to claim 6, wherein at least one of the upper limit operation accumulated value is changed to an increase side.   As the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases, the operation control device changes the fourth threshold value to the increase side and The fuel cell system according to claim 6 or 7, wherein at least one of the change to the increase side of the upper limit stop integrated value is performed. A fuel cell system comprising a solid oxide fuel cell that supplies energy generated by operation to a load unit, and an operation control device that controls the operation of the solid oxide fuel cell,
The operation control device includes:
When the solid oxide fuel cell is in operation, the future period based on the transition of the load energy in the past, with the constraint that the period during the operation is continued for a predetermined lower limit operation period or longer. Deriving a predicted value of load energy, if the predicted value is greater than or equal to a fifth threshold, it is determined that the solid oxide fuel cell should remain in operation, and the predicted value is less than the fifth threshold If it is determined that the solid oxide fuel cell should be stopped,
When the solid oxide fuel cell is stopped, the future period based on the transition of the load energy in the past, with the constraint that the period during the stop is longer than the predetermined lower limit stop period. A predicted value of load energy is derived, and if the predicted value is greater than or equal to a sixth threshold, it is determined that the solid oxide fuel cell should be operated, and if the predicted value is less than the sixth threshold, the solid Determined that the oxide fuel cell should remain stopped ,
The operation control device changes the fifth threshold value to a decreasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. fuel cell system to perform. A fuel cell system comprising a solid oxide fuel cell that supplies energy generated by operation to a load unit, and an operation control device that controls the operation of the solid oxide fuel cell,
The operation control device includes:
When the solid oxide fuel cell is in operation, the future period based on the transition of the load energy in the past, with the constraint that the period during the operation is continued for a predetermined lower limit operation period or longer. Deriving a predicted value of load energy, if the predicted value is greater than or equal to a fifth threshold, it is determined that the solid oxide fuel cell should remain in operation, and the predicted value is less than the fifth threshold If it is determined that the solid oxide fuel cell should be stopped,
When the solid oxide fuel cell is stopped, the future period based on the transition of the load energy in the past, with the constraint that the period during the stop is longer than the predetermined lower limit stop period. A predicted value of load energy is derived, and if the predicted value is greater than or equal to a sixth threshold, it is determined that the solid oxide fuel cell should be operated, and if the predicted value is less than the sixth threshold, the solid Determined that the oxide fuel cell should remain stopped,
The operation control device changes the sixth threshold value to the increasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. fuel cell system to perform. The operation control device changes the sixth threshold value to the increasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. The fuel cell system according to claim 9 to be performed. The system state quantity is a consumption primary energy reduction amount or energy cost reduction amount or emission carbon dioxide reduction amount obtained when the load energy to be supplied to the load unit is supplied from the solid oxide fuel cell, or these Driving merit that is a linear combination of any two or three of
The operation control device includes:
When said solid oxide fuel cell is operating, to derive the actual value of the operating benefits when fed past the load energy within a predetermined time period from the solid oxide fuel cell in operation thereof If the actual value is greater than or equal to the seventh threshold value, it is determined that the solid oxide fuel cell should remain in operation, and if the actual value is less than the seventh threshold value, the solid oxide fuel Determine that the battery should be shut down,
When the solid oxide fuel cell is stopped, the predicted value of the operation merit when it is assumed that the load energy is supplied from the solid oxide fuel cell within the past predetermined period during the stop. If the predicted value is equal to or greater than an eighth threshold value, it is determined that the solid oxide fuel cell should be operated. If the predicted value is less than the eighth threshold value, the solid oxide fuel cell is determined. The fuel cell system according to claim 1, wherein the fuel cell system is determined to be left stopped.   The operation control device changes the seventh threshold value to the decreasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. The fuel cell system according to claim 12 to be performed.   The operation control device changes the eighth threshold value to the increasing side as the number of times the solid oxide fuel cell is switched from the operating state to the stopped state or the number of times the solid oxide fuel cell is switched from the stopped state to the operating state increases. The fuel cell system according to claim 12 or 13, which is performed. The load energy is heat load energy and power load energy,
The operation control device includes:
When said solid oxide fuel cell is in operation, the transition of the past of the power load energy in past the thermal transition of the load energy is first when the operation stop condition is satisfied, or during the operation in the operation There the solid oxide fuel cell when the second shutdown condition is satisfied determines that it should be stopped, not satisfy the historical transition of the thermal load energy the first shutdown condition in its operation, the operation Determining that the solid oxide fuel cell should remain in operation when the transition of the power load energy in the past does not satisfy the second shutdown condition; and
When the solid oxide fuel cell is stopped due to the first operation stop condition being satisfied, the past transition of the thermal load energy and the transition of the power load energy during the stop are the first operation. Determining that the solid oxide fuel cell should be operated when a start condition is satisfied, determining that the solid oxide fuel cell should be stopped when the first operation start condition is not satisfied, and ,
When the solid oxide fuel cell is stopped because the second operation stop condition is satisfied, when the transition of the past power load energy during the stop satisfies the second operation start condition, the solid oxide fuel cell 3. The fuel cell system according to claim 2, wherein it is determined that the oxide fuel cell is to be operated, and it is determined that the solid oxide fuel cell is to be stopped when the second operation start condition is not satisfied. .

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