JP2011146208A - Operation control device for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation control device for fuel cell capable of operating a fuel cell in a desirable manner from the viewpoint of energy saving, economy, and environment protection while avoiding deterioration of the cells of the fuel cell. <P>SOLUTION: The operation control device 5 for fuel cell is used for a plurality of kinds of fuel cells FC which have different easiness of rising of oxygen concentration near the cathode of the fuel cell FC during operation stop. The operation control device 5 is provided with a memory means 5a which obtains and stores a time indicator information unique to the fuel cell FC that shows an allowable stop period that is a period in which the fuel cell FC can be allowed to continue to maintain in an operation stop condition, and which is defined shorter the more the oxygen concentration near the cathode of the fuel cell FC during operation stop tends to rise, and a control means 5b which controls operation of the fuel cell FC according to the stored time indicator information obtained, so that the frequency in which the fuel cell is operation stopped continuously for a period longer than the allowable stop period may be fewer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an operation control device for a fuel cell that is used for a plurality of types of fuel cells that have different oxygen concentration easiness in the vicinity of the cathode of the fuel cell during operation stop.

  There are continuous operation and intermittent operation as the operation mode of the fuel cell. For example, the operation control device described in Patent Document 1 has an operation merit (continuous operation merit) when it is assumed that the fuel cell is continuously operated, and an operation merit (intermittent operation merit) when the fuel cell is assumed to be intermittently operated. To determine whether to operate the fuel cell continuously or intermittently. In Patent Document 1, the above operating merits are energy savings indicated by an energy reduction amount by operating a fuel cell, economic efficiency indicated by an energy cost reduction cost by operating the fuel cell, etc. The environmental property indicated by the amount of carbon dioxide reduction by operating the battery. Therefore, by switching between continuous operation and intermittent operation using the operation merit as an index, a preferable operation can be performed from the viewpoint of energy saving, economic efficiency, environmental performance, and the like.

JP 2008-185316 A

Fuel cells include a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode is likely to increase during operation stop, and a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode is difficult to increase during operation stop. When the oxygen concentration in the vicinity of the cathode becomes high during shutdown, for example, as described in Japanese Patent Application No. 2008-225326, oxygen in the vicinity of the cathode enters the anode through the electrolyte, and the anode is oxidized ( May deteriorate).
The former fuel cell is, for example, a fuel cell having a large gas phase volume in a gas (gas containing oxygen such as air) supply path connected to a cathode. In the fuel cell having such a structure, even if the operation of the fuel cell is stopped and the supply of oxygen to the cathode is stopped, the oxygen concentration in the vicinity of the cathode is likely to increase thereafter. Specifically, since the amount of oxygen remaining in the gas supply path is increased according to the size of the gas phase volume, even if the oxygen concentration in the vicinity of the cathode is low immediately after the operation is stopped, Thereafter, oxygen concentration from the gas supply path side becomes relatively easy to increase in the vicinity of the cathode.
On the other hand, the latter fuel cell is, for example, a fuel cell having a structure in which the gas volume of the gas supply path connected to the cathode is small. In the fuel cell having such a structure, when the operation of the fuel cell is stopped and the supply of oxygen to the cathode is stopped, the oxygen concentration in the vicinity of the cathode hardly increases thereafter. Specifically, since the amount of oxygen remaining in the gas supply path is reduced according to the gas phase volume, even if oxygen diffuses from the gas supply path side to the vicinity of the cathode, The degree of increase in oxygen concentration is low.
Further, as a means for preventing the diffusion of oxygen to the vicinity of the cathode, it is conceivable to adopt a configuration in which the cathode is isolated by providing a valve upstream of the cathode or both upstream and downstream of the cathode. When measures are taken, there arises a problem that the apparatus cost increases.

  Even if oxygen is present in the vicinity of the cathode during shutdown, the gas containing hydrogen is filled in the vicinity of the anode (that is, the pressure of the gas containing hydrogen such as the remaining reformed gas is applied to the anode. In this case, oxygen in the vicinity of the cathode does not enter the anode via the electrolyte, or conversely, hydrogen in the vicinity of the anode enters the cathode through the electrolyte, so that oxidation (deterioration) of the anode occurs. Is suppressed. Alternatively, even if oxygen in the vicinity of the cathode enters the anode through the electrolyte, it is consumed by reacting with hydrogen existing in the vicinity of the anode, so that oxidation (deterioration) of the anode is suppressed. For example, when a fuel gas generation device for generating hydrogen used as a fuel gas for a fuel cell is connected to the fuel cell, the space between the fuel gas generation device and the fuel cell anode is integrally sealed during shutdown. If stopped, the state in which hydrogen remains in the vicinity of the anode for a long period can be maintained. As a result, the oxidation of the anode is prevented.

  However, when the fuel cell is intermittently operated as described above, if the fuel cell is stopped for a long period of time, hydrogen remaining between the fuel gas generator and the anode of the fuel cell enters the cathode side. Or by using it to consume oxygen that has entered the anode. Accordingly, if the fuel cell has a structure in which the oxygen concentration in the vicinity of the cathode is likely to increase during the operation stop, the oxygen concentration in the vicinity of the cathode cannot be lowered sufficiently and oxygen enters the anode from the cathode. As a result, oxidation (deterioration) of the anode may occur.

In addition, if it is the operation control apparatus which performs the operation control which does not stop a fuel cell for a long period of time, that is, when performing the intermittent operation of a fuel cell, the operation control which performs control which shortens the period when an operation stop state continues If it is an apparatus, the above-mentioned problem does not arise.
However, since the operation control device is a general-purpose device used for various fuel cells, it is a problem to uniformly perform operation control on all fuel cells so that the fuel cell is not stopped for a long period of time. is there. For example, in the case of a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode does not easily increase during the operation stop as described above, the oxygen concentration in the vicinity of the cathode can be kept sufficiently low for a long period of time, so that energy saving is achieved. Intermittent operation that keeps the operation stopped for a long time should be selected in consideration of safety, economy, and environmental characteristics. However, if the operation control is performed uniformly on all fuel cells so as to limit the operation stop state of the fuel cell to a short time, the fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode hardly increases during the operation stop. Since the stop state is limited to be shorter than necessary, there is a possibility that energy saving, economic efficiency, environmental performance and the like are deteriorated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a fuel cell according to the characteristics of the fuel cell while avoiding deterioration of the cell of the fuel cell composed of the anode and the cathode. The object is to provide an operation control device for a fuel cell that can be operated in a preferred mode from the viewpoint of energy saving, economy, environmental friendliness, and the like.

In order to achieve the above object, the characteristic configuration of the operation control device for a fuel cell according to the present invention is different from that for a plurality of types of fuel cells in which the oxygen concentration easily increases in the vicinity of the cathode of the fuel cell during operation stop. A fuel cell operation control device used,
The fuel representing a permissible stop period that is allowed to continue to maintain the fuel cell in a shutdown state, and is set to be short enough to increase the oxygen concentration in the vicinity of the cathode of the fuel cell during the shutdown. Storage means for acquiring and storing time index information specific to the battery;
Control means for controlling the operation of the fuel cell so that the frequency of occurrence of a long-term stop state in which the operation is stopped continuously for a period longer than the allowable stop period is reduced according to the time index information acquired and stored. In the point provided with.

According to the above characteristic configuration, the operation control device is a general-purpose device that is used for various fuel cells. However, the operation control device is configured according to the allowable stop period that is inherently determined for the fuel cell that is actually controlled. Operate according to the conditions. The permissible stop period has a relationship that is set shorter as the oxygen concentration in the vicinity of the cathode of the fuel cell is likely to increase during operation stop. In other words, the allowable stop period becomes shorter as the oxygen concentration near the cathode of the fuel cell during operation stop increases, so that the operation control device stops the fuel cell continuously for a longer period than the allowable stop period. By reducing the appearance frequency of the period stop state, it is possible to reduce the frequency of oxygen entering the anode from the cathode when the oxygen concentration in the vicinity of the cathode of the fuel cell increases. As a result, the oxidation (deterioration) of the anode can be suppressed as compared with the case where such frequency adjustment is not performed. In addition, by performing the operation according to the allowable stop period for each fuel cell, the period during which the operation stop state continues is not shortened more than necessary for the fuel cell, and energy saving when operating the fuel cell, It is ensured that economic efficiency and environmental performance do not deteriorate more than necessary.
Therefore, it is possible to operate the fuel cell in a preferable mode from the viewpoints of energy saving, economy, environment and the like according to the characteristics of the fuel cell while avoiding the deterioration of the fuel cell. A control device can be provided.

Another characteristic configuration of the operation control device for a fuel cell according to the present invention relates to determination of the operation mode of the fuel cell capable of supplying both heat and electric power within the operation mode determination target period,
The control means, at the start of the operation mode determination target period set to a length of the allowable stop period or less,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. The operation time is determined on the assumption that the fuel cell is intermittently operated with a part of the operation mode determination target period as an operation time period and the remaining time period as a non-operation time period. The driving merit that increases when driving merit is derived while changing the combination of the belt and the non-driving time zone is determined as the intermittent driving merit,
Based on the determined continuous operation merit and the intermittent operation merit, the operation mode of the fuel cell is determined to be either the continuous operation mode or the intermittent operation mode.
In the present invention, as the operation merit, the energy saving shown by the energy reduction amount by operating the cogeneration device, the economy shown by the energy cost reduction cost by operating the cogeneration device, or In addition, there are environmental characteristics indicated by the amount of carbon dioxide reduction by operating the combined heat and power supply device.

According to the above characteristic configuration, the operation control apparatus sets the operation mode determination target period of the fuel cell to a length equal to or shorter than the allowable stop period, so that the operation stop state is the longest continuous during at least the operation mode determination target period. Even if it does, the length for which the operation stop state continues is equal to or shorter than the allowable stop period. In other words, although there is a possibility that the fuel cell may be continuously stopped for two or more continuous operation mode determination target periods, the continuous operation mode or the intermittent operation mode is selected. However, a long-term stop state in which the operation is continuously stopped for a period longer than the allowable stop period does not appear within at least one operation form determination target period. As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.
In addition, in consideration of the above operating merits, the fuel cell operation mode is determined as either a continuous operation mode or an intermittent operation mode, so that the fuel cell is preferable from the viewpoints of energy saving, economic efficiency, environmental friendliness, etc. It can be operated in a manner.

Still another characteristic configuration of the operation control device for a fuel cell according to the present invention relates to determination of the operation mode of the fuel cell capable of supplying both heat and electric power within the operation mode determination target period.
The control means, at the start of the operation mode determination target period set to a length of the allowable stop period or less,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. The operation time is determined on the assumption that the fuel cell is intermittently operated with a part of the operation mode determination target period as an operation time period and the remaining time period as a non-operation time period. Driving merit that increases when driving merit is derived while changing the combination of the non-operating time zone and the non-operating time zone is determined as an intermittent driving merit, and the fuel cell is stopped in all time zones of the operation mode determination target period The operation merit when assuming that the operation is on standby is determined as the standby merit,
Based on the determined continuous operation merit, the intermittent operation merit, and the standby merit, the operation mode of the fuel cell is determined to be any one of the continuous operation mode, the intermittent operation mode, and the standby mode.

According to the above characteristic configuration, the operation control apparatus sets the operation mode determination target period of the fuel cell to a length equal to or shorter than the allowable stop period, so that the operation stop state is the longest continuous during at least the operation mode determination target period. Even if it does, the length for which the operation stop state continues is equal to or shorter than the allowable stop period. In other words, although there is a possibility that the fuel cell is continuously stopped for a length equal to or longer than the allowable stop period over two continuous operation mode determination target periods, any of the continuous operation mode, the intermittent operation mode, and the standby mode is Even if selected, a long-term stop state in which the operation is continuously stopped for a period longer than the allowable stop period does not appear within at least one operation mode determination target period. As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.
In addition, in consideration of the above operating merits, the operation mode of the fuel cell is determined as one of the continuous operation mode, the intermittent operation mode, and the standby mode. It can be operated in a preferred mode from the viewpoint.

Still another characteristic configuration of the operation control device for a fuel cell according to the present invention relates to determination of the operation mode of the fuel cell capable of supplying both heat and electric power within the operation mode determination target period.
The control means, at the start time of the operation mode determination target period,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. Determined as a merit, and a part of the operation mode determination target period is set as an operation time period and the remaining time period is set as a non-operation time period and is continuously before and after the operation time period. Assuming that the fuel cell is intermittently operated by limiting the continuous stop period that is generated to be less than or equal to the allowable stop period, it becomes larger when the operation merit is derived while changing the combination of the operation time period and the non-operation time period. It is assumed that the operation merit is determined as an intermittent operation merit and that the fuel cell is stopped and the operation is waited in the entire time period of the operation mode determination target period. Determining the operating benefits when a waiting merit,
Based on the determined continuous operation merit, the intermittent operation merit, and the standby merit, the operation mode of the fuel cell is determined to be any one of the continuous operation mode, the intermittent operation mode, and the standby mode.

According to the above characteristic configuration, the operation control device limits the continuous stop period that continuously occurs before and after the operation time period in the intermittent operation mode to the allowable stop period or less, so the intermittent operation mode is implemented. Even if the operation stop state continues for the longest, the length of the operation stop state continues is equal to or shorter than the allowable stop period. That is, when the continuous operation mode and the intermittent operation mode among the continuous operation mode, the intermittent operation mode, and the standby mode are selected, the long-term stop state in which the operation is continuously stopped for a period longer than the allowable stop period does not appear. As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.
In addition, in consideration of the above operating merits, the operation mode of the fuel cell is determined as one of the continuous operation mode, the intermittent operation mode, and the standby mode. It can be operated in a preferred mode from the viewpoint.

  Still another characteristic configuration of the operation control device for a fuel cell according to the present invention is that the control means determines the continuous operation merit to a value larger than the value of the actually derived operation merit.

When intermittent operation is performed, there may be a problem of oxidation (deterioration) of the anode due to oxygen entering from the cathode to the anode while the fuel cell is stopped.
However, according to this feature configuration, the continuous operation is more easily selected than the intermittent operation, and thus the above-described problem that may occur when the intermittent operation is performed can be avoided.

Still another characteristic configuration of the operation control device for a fuel cell according to the present invention relates to determination of the operation mode of the fuel cell capable of supplying both heat and electric power within the operation mode determination target period.
The control means, at the start of the operation mode determination target period set to a length of the allowable stop period or less,
Based on the time-series predicted power load and the time-series predicted heat load, a part of the operation mode determination target period is an operation time period and the remaining time period is a non-operation time period Assuming that the fuel cell is intermittently operated, an operation merit that increases when an operation merit is derived while changing a combination of the operation time zone and the non-operation time zone is determined as an intermittent operation merit, and the operation mode determination The operation merit when assuming that the fuel cell is stopped and the operation is waited in the entire time period of the target period is determined as the standby merit,
Based on the determined intermittent operation merit and the standby merit, the operation mode of the fuel cell is determined to be either the intermittent operation mode or the standby mode.

According to the above characteristic configuration, the operation control apparatus sets the operation mode determination target period of the fuel cell to a length equal to or shorter than the allowable stop period, so that the operation stop state is the longest continuous during at least the operation mode determination target period. Even if it does, the length for which the operation stop state continues is equal to or shorter than the allowable stop period. That is, regardless of whether the intermittent operation mode or the standby mode is selected, a long-term stop state in which the operation is stopped continuously for a period longer than the allowable stop period does not appear within at least one operation mode determination target period. As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.
In addition, in consideration of the above operating merits, the fuel cell operation mode is determined to be either the intermittent operation mode or the standby mode, so that the fuel cell is preferable from the viewpoints of energy saving, economic efficiency, environmental friendliness, etc. You can drive in.

  When the fuel cell is continuously operated, heat is continuously generated, so that there is a possibility that the heat is excessive. For this reason, it may be necessary to provide a heat radiating means such as a radiator for discarding excess heat so that the control means performs a heat radiating operation at an appropriate timing. On the other hand, when the fuel cell is intermittently operated, heat is also generated intermittently, so that the possibility of excess heat is lower than in the case of continuous operation. That is, if the fuel cell is not continuously operated as in this feature configuration, it is possible not to provide a heat dissipating means for discarding excess heat. There is also no need to control the heat release operation. Therefore, the function of the operation control device can be simplified.

Still another characteristic configuration of the operation control device for a fuel cell according to the present invention relates to determination of the operation mode of the fuel cell capable of supplying both heat and electric power within the operation mode determination target period.
The control means, at the start time of the operation mode determination target period,
Based on the time-series predicted power load and the time-series predicted heat load, a part of the operation mode determination target period is set as an operation time period, and the remaining time period is set as a non-operation time period. Assuming that the fuel cell is intermittently operated with the continuous stop period continuously generated before and after the operation time period being limited to the allowable stop period or less, the operation time period and the non-operation time period When driving merit is derived when driving merit is changed while changing the combination, it is determined as intermittent driving merit, and when the fuel cell is stopped in all time zones of the operation mode determination target period and the operation is put on standby The driving merit when assumed is determined as the standby merit,
Based on the determined intermittent operation merit and the standby merit, the operation mode of the fuel cell is determined to be either the intermittent operation mode or the standby mode.

According to the above characteristic configuration, the operation control device limits the continuous stop period that continuously occurs before and after the operation time period in the intermittent operation mode to the allowable stop period or less, so the intermittent operation mode is implemented. Even if the operation stop state continues for the longest, the length of the operation stop state continues is equal to or shorter than the allowable stop period. That is, when the intermittent operation mode is selected from the intermittent operation mode and the standby mode, the long-term stop state in which the operation is stopped continuously for a period longer than the allowable stop period does not appear. As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.
In addition, in consideration of the above operating merits, the fuel cell operation mode is determined to be either the intermittent operation mode or the standby mode, so that the fuel cell is preferable from the viewpoints of energy saving, economic efficiency, environmental friendliness, etc. You can drive in.

  When the fuel cell is continuously operated, heat is continuously generated, so that there is a possibility that the heat is excessive. For this reason, it may be necessary to provide a heat radiating means such as a radiator for discarding excess heat so that the control means performs a heat radiating operation at an appropriate timing. On the other hand, when the fuel cell is intermittently operated, heat is also generated intermittently, so that the possibility of excess heat is lower than in the case of continuous operation. That is, if the fuel cell is not continuously operated as in this feature configuration, it is possible not to provide a heat dissipating means for discarding excess heat. There is also no need to control the heat release operation. Therefore, the function of the operation control device can be simplified.

  Still another characteristic configuration of the operation control apparatus for a fuel cell according to the present invention is that the control means controls the operation of the fuel cell so that the long-term stop state does not appear.

  According to the above characteristic configuration, a long-term stop state in which the fuel cell is continuously stopped for a period longer than the allowable stop period does not appear. That is, the oxidation (deterioration) of the anode can be suppressed by preventing oxygen from entering the anode from the cathode.

Still another characteristic configuration of the operation control device for a fuel cell according to the present invention relates to determination of the operation mode of the fuel cell capable of supplying both heat and electric power within the operation mode determination target period.
The control means, at the start time of the operation mode determination target period,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. Determined as a merit, and a part of the operation mode determination target period is set as an operation time period and the remaining time period is set as a non-operation time period and is continuously before and after the operation time period. Assuming that the fuel cell is intermittently operated by limiting the continuous stop period that is generated to be less than or equal to the allowable stop period, it becomes larger when the operation merit is derived while changing the combination of the operation time period and the non-operation time period. The driving merit is determined as the intermittent driving merit,
Based on the determined continuous operation merit and the intermittent operation merit, the operation mode of the fuel cell is determined to be either the continuous operation mode or the intermittent operation mode.

According to the above characteristic configuration, the operation control device limits the continuous stop period that continuously occurs before and after the operation time period in the intermittent operation mode to the allowable stop period or less, so the operation stop in the intermittent operation mode. Even if the state continues for the longest time, the length of the continuous operation stop state is equal to or shorter than the allowable stop period. In other words, even if either the continuous operation mode or the intermittent operation mode is selected, a long-term stop state in which the fuel cell is continuously stopped for a period longer than the allowable stop period within the operation mode determination target period does not appear. It is possible to prevent oxygen from entering the anode. As a result, the oxidation (deterioration) of the anode can be suppressed.
In addition, in consideration of the above operating merits, the fuel cell operation mode is determined as either a continuous operation mode or an intermittent operation mode, so that the fuel cell is preferable from the viewpoints of energy saving, economic efficiency, environmental friendliness, etc. It can be operated in a manner.

Still another characteristic configuration of the operation control device for a fuel cell according to the present invention is that, among the continuous stop periods, the first continuous stop period that occurs continuously before the operation time period is an operation mode determination target. A period in which the fuel cell is continuously stopped before the start of the period, and a period in which the fuel cell is continuously stopped after the start of the operation mode determination target period and before the operation time period. Is sum,
The second continuous stop period that continuously occurs after the operation time period in the continuous stop period is during the operation mode determination target period and the fuel cell is continuously stopped after the operation time period. It is a point to be a period to do.

  According to the above characteristic configuration, the first continuous stop period continuously generated before the operation time period is not only the period in which the fuel cell continuously stops after the start of the operation form determination target period, but also the operation form. It includes a period in which the fuel cell is continuously stopped before the start of the determination target period. Further, the second continuous stop period that continuously occurs after the operation time period is a period during which the fuel cell is continuously stopped after the operation mode determination target period. Therefore, it is possible to appropriately determine the continuous stop period that continuously occurs before and after the operation time period of the operation form determination target period.

It is a block diagram which shows the whole structure of the cogeneration system of 1st Embodiment. It is a figure which shows the structure of a fuel cell system. It is a block diagram which shows the control structure of a cogeneration system. It is a figure which shows a prediction electric power load and a prediction heat load. It is explanatory drawing which shows the driving | running state and heat utilization state of a fuel cell with respect to the prediction electric power load and prediction heat load in an operation period. It is a figure explaining a temporary driving pattern. It is a figure which shows the flowchart of the control action of 1st Embodiment. It is a figure which shows the relationship between a prediction heat load and a prediction energy reduction amount. It is a figure explaining the relationship between the temporary operation pattern in 2nd Embodiment, the continuous stop period before starting, and the continuous stop period after stop. It is a block diagram which shows the whole structure of the cogeneration system of 3rd Embodiment. It is a figure which shows the flowchart of the control action of 3rd Embodiment.

A configuration of a cogeneration system provided with an operation control device according to the present invention, which is common to each embodiment, will be described first with reference to the drawings. Subsequently, operation control of the fuel cell by the operation control device of the first to fourth embodiments will be described separately.
FIG. 1 is a block diagram showing the overall configuration of the cogeneration system. FIG. 2 is a diagram schematically showing a configuration of a fuel cell system included in the cogeneration system. FIG. 3 is a block diagram showing a control configuration of the cogeneration system.
As shown in the figure, the cogeneration system 1 includes a fuel cell system 50 having a fuel cell FC that generates both heat and electricity, and an operation control device 5 for the fuel cell that controls the operation of the fuel cell system 50. Prepare. Further, the cogeneration system 1 collects heat generated by the fuel cell FC with cooling water, and uses the cooling water to store hot water in the hot water tank 2 and a heat medium to the hot water supply unit 3A and the heat consuming terminal 3B. A hot water storage unit 4 that supplies water is provided, and the operation of the hot water storage unit 4 is controlled by an operation control device 5. The electric power generated in the fuel cell FC is supplied to the power load device 9, and the heat generated in the fuel cell FC is supplied to the heat load device 3 (the hot water supply unit 3A, the heat consuming terminal 3B).

  The fuel cell system 50 includes a fuel cell FC and a fuel gas generation device 51 that generates a fuel gas mainly composed of hydrogen as a fuel of the fuel cell FC. The fuel cell operation control device 5 according to the present invention is a general-purpose device for controlling the operation of the fuel cell system 50. Therefore, the operation of various types of fuel cells FC can be controlled. Specifically, the operation control device 5 responds to the memory 5a as storage means for receiving and storing information about the characteristics of the fuel cell FC, and the information about the characteristics of the fuel cell FC stored in the memory 5a. And a control unit 5b as control means for controlling the operation of the fuel cell FC.

Information about the characteristics of the fuel cell FC described above is automatically transferred from the fuel cell FC to the operation control device 5 when the fuel cell FC and the operation control device 5 are communicably connected to the memory 5a. The installer operates the input device (not shown) provided in the fuel cell FC or the operation control device 5 when the fuel cell FC and the operation control device 5 are communicably connected to each other. By doing so, it is transferred from the fuel cell FC to the operation control device 5 and stored in the memory 5a.
In the embodiment described below, the information on the characteristics of the fuel cell FC is specific to the fuel cell FC that represents an allowable stop period in which the fuel cell FC can be continuously maintained in the operation stop state, as will be described later. Time index information.

  A grid interconnection inverter 6 is provided on the power output side of the fuel cell FC. The inverter 6 sets the generated power of the fuel cell FC to the same voltage and the same frequency as the received power received from the commercial power source 7. The inverter 6 is electrically connected to the received power supply line 8 via the generated power supply line 10, and the generated power from the fuel cell FC is supplied to the power load device 9 via the inverter 6 and the generated power supply line 10. Supplied. A received power supply line 8 that supplies power to a power load device 9 such as a television, a refrigerator, or a washing machine is connected to a commercial power source 7.

  The received power supply line 8 is provided with power load measuring means 11 for measuring the load power of the power load device 9. The power load measuring means 11 also detects whether or not a reverse power flow occurs in the current flowing through the received power supply line 8. The power supplied from the fuel cell FC to the received power supply line 8 is controlled by the inverter 6 so that a reverse power flow does not occur. The surplus power of the power generated by the fuel cell FC is obtained by replacing the surplus power with heat. The electric heater 12 to be recovered is supplied.

  The electric heater 12 is composed of a plurality of resistance heaters, and heats the cooling water of the fuel cell FC flowing through the cooling water circulation path 13 by the operation of the cooling water circulation pump 15. The electric heater 12 is turned ON / OFF by an operation switch 14 connected to the output side of the inverter 6. The operation switch 14 is switched so that the power consumption of the electric heater 12 increases as the surplus power of the fuel cell FC increases.

  Hereinafter, the configuration of the fuel cell system, the stop transition process of the fuel cell FC, the stop state maintaining step of the fuel cell FC, the configuration of the hot water storage unit, and the operation control of the fuel cell by the operation control device will be described in order.

[Configuration of fuel cell system]
As shown in FIG. 2, the fuel cell system 50 includes a fuel cell FC and a fuel gas generation device 51 that generates a fuel gas containing hydrogen as a main component as a fuel of the fuel cell FC. The fuel gas generator 51 steam-reforms the raw fuel gas containing hydrocarbons such as methane in the reformer 51a to generate a fuel gas mainly composed of hydrogen. In addition to the reformer 51a shown in FIG. 2, the fuel gas generator 51 includes a desulfurizer, a steam generator, and a gas obtained by steam reforming for removing sulfur compounds contained in the raw material gas. The carbon monoxide remover etc. which remove the carbon monoxide contained in are provided, but those descriptions are omitted.

  The fuel cell FC includes a cell 52 that generates power. The cell 52 is configured by providing an electrolyte 52c between an anode 52a to which a fuel gas containing hydrogen is supplied and a cathode 52b to which an oxidant gas is supplied. A fuel gas generation device 51 is connected to the gas supply path 53 to the anode 52a. The fuel gas generated by the fuel gas generation device 51 is supplied to the fuel cell FC via the gas supply path 53.

In the middle of the gas supply path 53 to the anode 52a, a fuel gas humidifier 54 having a fuel gas storage water tank 54a is provided. In the fuel gas humidifier 54, the fuel gas is supplied from the fuel gas generation device 51 through the gas supply path 53 into the stored water stored in the fuel gas storage water tank 54a, and is supplied to the surface of the stored water. While coming out, humidify the fuel gas in contact with the stored water. The space on the surface of the stored water inside the fuel gas storage water tank 54a is connected to the anode 52a. In the middle of the gas supply path 53 from the fuel gas generation device 51 to the anode 52a, a valve V2 for blocking or allowing the gas flow in the gas supply path 53 is provided.
The gas used for the power generation reaction in the anode 52 a is discharged to the outside of the fuel cell FC through the gas discharge path 57. The exhausted gas is recovered in exhaust heat in a heat exchanger (not shown) and then provided to an exhaust process such as burning in a burner (not shown). In the middle of the gas discharge path 57, a valve V <b> 3 that blocks or allows the gas flow in the gas discharge path 57 is provided.

Air as an oxidant gas is supplied to the cathode 52b through the gas supply path 55 by the blower 59. In the middle of the gas supply path 55, an oxidant gas humidifier 56 having an oxidant gas storage water tank 56a is provided. In the oxidant gas humidifier 56, the air supplied from the blower 59 is supplied to the stored water stored in the oxidant gas storage water tank 56a through the gas supply path 55, and the surface of the stored water. While coming out, the oxidant gas is brought into contact with the stored water and humidified. A space on the surface of the stored water inside the oxidant gas storage water tank 56a is connected to the cathode 52b.
The gas used for the power generation reaction at the cathode 52 b is discharged to the outside of the fuel cell FC through the gas discharge path 58. The exhausted gas is recovered as exhaust heat by a heat exchanger (not shown). Since the exhausted gas is originally air present in the surroundings, no special exhaust treatment is required.

  In addition, the fuel cell FC has a water amount regulator 60. The water amount adjuster 60 includes a water level adjusting tank 62 that stores stored water supplied to the fuel gas storage water tank 54a and the oxidant gas storage water tank 56a, and the fuel gas storage water tank 54a and the oxidant gas storage tank. A water level control unit 61 for adjusting the water level of the stored water in the stored water tank 56a is provided. The water level adjustment tank 62 and the fuel gas storage water tank 54a are connected by a flow path 63, and the water level adjustment tank 62 and the oxidant gas storage water tank 56a are connected by a flow path 64.

  On the inner side wall of the fuel gas storage water tank 54a, a level sensor 54b that can detect whether or not the stored water is above the maximum water level, and a level that can detect whether or not the stored water is below the minimum water level. A sensor 54c is provided. Similarly, on the inner side wall of the oxidant gas storage water tank 56a, a level sensor 56b that can detect whether or not the stored water is at or above the maximum water level, and whether or not the stored water is below the minimum water level. A detectable level sensor 56c is provided. Then, the water level controller 61 of the water amount adjuster 60 is configured such that during the power generation of the fuel cell FC, the stored water levels in the fuel gas storage water tank 54a and the oxidant gas storage water tank 56a are the highest and lowest water levels described above. It is adjusted to be between.

[Fuel cell FC stop transition process]
The stop transition step of stopping the operation of the fuel cell FC is a step of releasing the electrical connection between the inverter 6 and the cell 52 of the fuel cell FC and stopping the output of the electric power obtained by the power generation in the fuel cell FC. It is. Therefore, the supply amount of the raw material gas and the supply amount of the oxidant gas (air) to the fuel cell FC are reduced before the output of the electric power obtained by the power generation in the fuel cell FC is stopped. As a result, the amount of gas generated inside the reformer 51a decreases, and the pressure of the reformer 51a also decreases. Further, the temperature of the fuel cell FC (that is, the temperature of the anode 52a and the cathode 52b) gradually decreases.

  Thereafter, the blower 59 is stopped and the supply of air to the cathode 52b is stopped. At this time, the raw material gas is supplied to the fuel gas generation device 51, and the supply of the fuel gas from the fuel gas generation device 51 to the anode 52a is continued. Therefore, in the cell 52, the supply amount of air is very small as compared with the supply amount of fuel gas, and the cell voltage rapidly decreases. The cell voltage can be detected by the voltage sensor 34. That is, here, the air (oxygen) remaining on the cathode 52b reacts with the fuel gas (hydrogen) remaining on the anode 52a in a state where the supply of air to the cathode 52b is stopped. Then, the electrical connection between the inverter 6 and the cell 52 of the fuel cell FC is released, and the output of the electric power obtained by the power generation in the fuel cell FC is stopped.

[Fuel cell FC stopped state maintenance process]
In the stopped state maintaining step of maintaining the stopped state of the fuel cell FC, the hydrogen-containing gas supply process for supplying the hydrogen-containing gas to the anode 52a at the set timing is performed in a state where the supply of the gas to the cathode 52b is stopped. The hydrogen-containing gas supply process closes a predetermined part of the gas distribution system that leads to the anode 52a inside the fuel gas generation device 51 in a state where the gas flow between the fuel gas generation device 51 and the anode 52a is allowed. In addition, it is performed at a set timing during the anode isolation process for closing the gas discharge path 57 from the anode 52a. Specifically, in the stopped state maintaining step, the valve V2 is opened to allow the gas to flow between the fuel gas generation device 51 and the anode 52a, and the valve V1 and the valve V3 are closed to generate the fuel gas. An anode isolation process for closing the apparatus 51 to the gas discharge path 57 of the anode 52a is performed. Then, while the anode isolation process is continuously performed, at the set timing, the valve V1 is opened and the raw material gas is caused to flow into the fuel gas generator 51. In other words, by opening the valve V1 at a set timing while the anode isolation process in which the valve V1 and the valve V3 are closed is continuously performed (ie, the isolation state of the anode in which the anode isolation process is being performed) The hydrogen-containing gas supply process is performed (by opening the valve V1 temporarily to release the valve V1), and then the anode isolation process is performed to set the anode isolation state again. By flowing the gas from the fuel gas generating device 51 to the anode 52a, a hydrogen-containing gas supply process is performed in which the hydrogen-containing gas remaining upstream of the anode 52a is supplied to the anode 52a.

  As described above, the pressure of the anode 52a can be maintained with the hydrogen-containing gas, so that intrusion of air from the outside to the anode 52a can be suppressed, and there is no invasion of oxygen from the cathode 52b to the anode 52a. Even so, the invaded oxygen reacts with the hydrogen-containing gas supplied to the anode 52a and is consumed, so that the anode 52a can be prevented from being oxidized by the oxygen.

  After performing the hydrogen-containing gas supply process for a predetermined period, the hydrogen-containing gas supply process is stopped. For example, when the time from the start of the stop state maintaining process reaches a predetermined time, or when the temperature of the anode 52a is lowered to a predetermined temperature (for example, the outside air temperature + 5 ° C.), the hydrogen-containing gas supply process Is determined to have been implemented for a predetermined period. Then, after stopping the hydrogen-containing gas supply process, in the state where the gas flow between the fuel gas generation device 51 and the anode 52a is allowed (the valve V2 is opened), the inside of the fuel gas generation device 51 The fuel cell FC is stored in such a manner that a predetermined part of the gas flow system leading to the anode 52a is closed (valve V1 is closed) and the gas discharge path 57 from the anode 52a is closed (valve V3 is closed).

  As described above, by supplying the hydrogen-containing gas to the anode 52a and increasing the pressure of the anode 52a, it becomes difficult for gas (for example, oxygen) to enter the anode 52a from the outside (for example, the cathode 52b). Therefore, since the oxidation of the anode 52a is suppressed, the deterioration of the anode 52a can be suppressed.

[Configuration of hot water storage unit]
The hot water storage unit 4 circulates hot water for heat source through a hot water tank 2 for storing hot water in a state where temperature stratification is formed, a hot water circulation pump 17 for circulating hot water in the hot water tank 2 through the hot water circulation path 16, and a heat source circulation path 20. A heat source circulation pump 21, a heat medium circulation pump 23 that circulates and supplies the heat medium to the heat consuming terminal 3B through the heat medium circulation path 22, a hot water storage heat exchanger 24 that heats the hot water flowing through the hot water circulation path 16, and a heat source. The heat source heat exchanger 25 for heating the hot water for the heat source flowing through the circulation path 20, the heat exchanger 26 for heating the heating medium for heating the heat medium flowing through the heating medium circulation path 22, and the hot water storage tank 2 are taken out. And an auxiliary heater 28 for heating the hot water flowing through the hot water supply passage 27 and the hot water flowing through the heat source circulation passage 20.

  The hot water circulation path 16 is connected to the bottom and top of the hot water tank 2 so that hot water taken out from the bottom of the hot water tank 2 is returned to the top of the hot water tank 2 by the hot water circulation pump 17. Then, it is circulated through a hot water storage heat exchanger 24 provided on the way. Hot water circulated through the hot water circulation path 16 is heated by the hot water storage heat exchanger 24, whereby hot water is stored in a state where a temperature stratification is formed in the hot water storage tank 2. The hot water circulation path 16 is branched and connected so that a part thereof is in parallel, and a three-way valve 18 is provided at the connection location. A radiator 19 is provided in one of the branched flow paths. Then, by switching the three-way valve 18, the hot water taken out from the lower part of the hot water tank 2 is circulated so as to pass through the radiator 19, and the hot water taken out from the lower part of the hot water tank 2 is circulated so as to bypass the radiator 19. The state is switched to

  The hot water supply passage 27 is connected to the hot water storage tank 2 through a location downstream of the hot water storage heat exchanger 24 in the hot water circulation passage 16. Accordingly, the hot water in the hot water tank 2 is supplied to the hot water supply section 3A such as a bathtub, a hot water tap and a shower through the hot water supply path 27. A water supply channel 29 is connected to the bottom of the hot water storage tank 2, and hot water in the hot water storage tank 2 is supplied through the hot water supply channel 27 to supply water to the hot water storage tank 2 through the water supply channel 29.

  The heat source circulation path 20 is provided so as to form a circulation path in a state where a part of the hot water supply path 27 is shared. In the middle of the heat source circulation path 20, a heat source interrupting valve 40 for interrupting the flow of the heat source hot water is provided.

  The auxiliary heater 28 combusts in the auxiliary heating heat exchanger 28a provided in the hot water supply passage 27 shared with the heat source circulation path 20, the burner 28b for heating the auxiliary heating heat exchanger 28a, and the burner 28b. It comprises a fan 28c for supplying working air, a combustion control unit (not shown) for controlling the operation of the auxiliary heater 28, and the like. The combustion control unit adjusts the amount of gas fuel supplied to the burner 28b so that the hot water supplied to the auxiliary heating heat exchanger 28a is heated to the target hot water temperature and discharged.

  The coolant circulation path 13 is branched into a hot water storage heat exchanger 24 side and a heat source heat exchanger 25 side. At the branch point, a diversion valve 30 is provided that adjusts the ratio of the flow rate of the cooling water that flows to the hot water storage heat exchanger 24 side and the flow rate of the cooling water that flows to the heat source heat exchanger 25 side. The diversion valve 30 can flow the entire amount of cooling water in the cooling water circulation path 13 to the hot water storage heat exchanger 24 side, and allows the entire amount of cooling water in the cooling water circulation path 13 to flow to the heat source heat exchanger 25 side. It can also be made.

  The hot water storage heat exchanger 24 heats the hot water flowing through the hot water circulation path 16 by flowing the cooling water in the cooling water circulation path 13 that has recovered the heat generated by the fuel cell FC. The heat source heat exchanger 25 heats the heat source hot water flowing through the heat source circulation path 20 by flowing the cooling water of the cooling water circulation path 13 that has recovered the heat generated by the fuel cell FC. The heat medium heating heat exchanger 26 heats the heat medium flowing through the heat medium circulation path 22 by flowing hot water for the heat source heated by the heat exchanger 25 for heat source or the auxiliary heater 28. . The heat consuming terminal 3B is composed of a heating terminal such as a floor heating device or a bathroom heating device.

  The hot water supply passage 27 is provided with a hot water supply heat load measuring means 31 for measuring a hot water supply heat load when hot water is supplied to the hot water supply section 3A, and a terminal heat load measurement for measuring a terminal heat load at the heat consuming terminal 3B. Means 32 are also provided. In addition, although illustration is abbreviate | omitted, these hot water supply thermal load measurement means 31 and the terminal thermal load measurement means 32 are the temperature sensor which detects the temperature of the flowing hot water and heat medium, and the flow volume which detects the flow volume of hot water and a heat medium. And a sensor, and configured to detect a thermal load based on a detected temperature of the temperature sensor and a detected flow rate of the flow sensor.

A hot water storage temperature sensor Sh that detects the temperature of the hot water heated by the hot water storage heat exchanger 24 and supplied to the hot water tank 2 is provided at a location downstream of the hot water storage heat exchanger 24 in the hot water circulation path 16. ing.
The hot water tank 2 has an upper end temperature sensor S1 for detecting the temperature of hot water at the upper end of the upper layer of the hot water tank 2, and hot water at the boundary between the upper layer and middle layer of the hot water tank 2 for detecting the amount of stored hot water. An intermediate upper temperature sensor S2 for detecting the temperature of the hot water tank, an intermediate lower temperature sensor S3 for detecting the temperature of hot water at the boundary between the middle layer and the lower layer of the hot water tank 2, and hot water at the lower end of the lower layer of the hot water tank 2 A lower end temperature sensor S4 for detecting the temperature of the hot water tank 2 is provided, and a water supply temperature sensor Si for detecting the temperature of the water supplied to the hot water tank 2 is provided in the water supply passage 29.

Next, a method for calculating the amount of stored hot water in the hot water tank 2 by the operation control unit 5 will be described.
The hot water temperature in the hot water tank 2 detected by the upper end temperature sensor S1, the intermediate upper temperature sensor S2, the intermediate lower temperature sensor S3, and the lower end temperature sensor S4 is T1, T2, T3, and T4, respectively. The water supply temperature detected in Si is Ti, and the capacities of the upper layer portion, the middle layer portion, and the lower layer portion are V.
The weighting factor in the upper layer is A1, the weighting factor in the middle layer is A2, the weighting factor in the lower layer is A3, and the coefficient for converting the unit of energy between watts and calories is α (for example, “860”). Is set), the hot water storage amount (W) can be calculated by the following (Equation 1).

Hot water storage heat amount = {(A1 × T1 + (1-A1) × T2-Ti) × V
+ (A2 * T2 + (1-A2) * T3-Ti) * V
+ (A3 × T3 + (1-A3) × T4-Ti) × V} ÷ α (Equation 1)

  The weighting factors A1, A2, A3 are empirical values considering past temperature distribution data in each layer of the hot water tank 2. Here, as A1, A2, A3, for example, A1 = A2 = 0.2 and A3 = 0.5. A1 = A2 = 0.2 indicates that the influence of the temperature T2 is larger than the influence of the temperature T1 in the upper layer portion. This indicates that 80% of the upper layer is close to the temperature T2, and 20% is close to the temperature T1. The same applies to the middle layer portion. In the lower layer part, it shows that the influence of temperature T3 and T4 is the same.

  The operation control device 5 controls the operation of the fuel cell FC in a state where the cooling water circulation pump 15 is operated during the operation of the fuel cell FC, and the hot water circulation pump 17, the heat source circulation pump 21, the heat medium circulation pump. 23, the hot water storage operation for storing hot water in the hot water storage tank 2 and the heat medium supply operation for supplying the heat medium to the heat consuming terminal 3B are performed by controlling the operations of the diversion valve 30 and the heat source intermittent valve 40, respectively.

  The operation control device 5 performs a hot water storage operation in a state where no operation command is given from a terminal remote controller (not shown) for the heat consuming terminal 3B. In the hot water storage operation, the operation control device 5 switches the diversion valve 30 to a state in which the entire amount of cooling water is allowed to flow to the hot water storage heat exchanger 24 side, and closes the heat source intermittent valve 40, and the hot water storage temperature sensor. Based on the detection information of Sh, the hot water circulation pump 17 is operated to adjust the hot water circulation amount so that the temperature of the hot water supplied to the hot water tank 2 becomes a preset target hot water temperature (for example, 60 ° C.). To control. And by this hot water storage operation, the hot water of the target hot water temperature is stored in the hot water tank 2.

When the operation is commanded from the terminal remote controller, the operation control device 5 performs the heat medium supply operation. In the heat medium supply operation, the operation control device 5 opens the heat source intermittent valve 40 and operates the heat source circulation pump 21 at a preset rotational speed, so that the terminal heat at the heat consuming terminal 3B is reached. The flow dividing valve 30 is controlled so that the amount of cooling water corresponding to the load flows through the heat source heat exchanger 25. When the operation control device 5 controls the state where the diverter valve 30 allows the cooling water to flow also to the hot water storage heat exchanger 24 side in a state where the heat medium supply operation is performed, the hot water circulation pump 17 of the hot water circulation pump 17 is operated as described above. The hot water storage operation is executed in parallel with the heat medium supply operation by controlling the operation.
When the operation control device 5 is instructed to stop the operation from the terminal remote controller during the heat medium supply operation, the operation control device 5 switches the diversion valve 30 to a state in which the entire amount of the cooling water is allowed to flow to the hot water storage heat exchanger 24 side. Then, the heat source intermittent pump 40 is closed, the heat source circulation pump 21 is stopped, and the hot water circulation pump 17 is operated to switch from the heat medium supply operation to the hot water storage operation.

  When the hot water in the hot water tank 2 is supplied to the hot water supply unit 3A through the hot water supply passage 27 and during the execution of the heat medium supply operation, the combustion control unit of the auxiliary heater 28 is connected to the auxiliary heating heat exchanger 28a. When the temperature of the supplied hot water is lower than the target hot water temperature, the amount of gas fuel supplied to the burner 28b is adjusted so that the hot water supplied to the auxiliary heating heat exchanger 28a is heated to the target hot water temperature and discharged. To do.

  Further, the operation control device 5 stores hot water up to the bottom of the hot water tank 2 when the temperature detected by the lower end temperature sensor S4 is equal to or higher than a preset temperature for heat radiation operation during the hot water storage operation. Judge that the amount of hot water storage is full. Then, the operation control device 5 switches the three-way valve 18 to a state in which the hot water taken out from the lower part of the hot water tank 2 is circulated so as to pass through the radiator 19 and operates the radiator 19, thereby taking the hot water taken out from the lower part of the hot water tank 2. After being radiated by the radiator 19, it is heated by passing through the hot water storage heat exchanger 24 and supplied to the hot water tank 2.

<First Embodiment>
Hereinafter, operation control of the fuel cell by the operation control apparatus of the first embodiment will be described.
The operation control device 5 of the present embodiment avoids deterioration of the cell 52 of the fuel cell FC, and continuously operates or intermittently operates the fuel cell FC in a manner preferable from the viewpoint of energy saving, economy, environment, and the like. Operation control of the fuel cell FC is performed so as to be operated.

First, the problem of deterioration of the cell 52 of the fuel cell FC will be described below.
The fuel cell FC includes a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b is likely to increase during operation stop, and a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b is difficult to increase during operation stop. is there. If the oxygen concentration at the cathode 52b becomes high during the operation stop, oxygen near the cathode 52b may enter the anode 52a through the electrolyte 52c, and the anode 52a may be oxidized (deteriorated).
In the former fuel cell, for example, the gas volume of the gas supply path 55 connected to the cathode 52b is large (in the case of this embodiment, from the surface of the stored water inside the oxidant gas storage water tank 56a to the cathode 52b. This is a fuel cell with a large gas phase volume. In the fuel cell having such a structure, even if the operation of the fuel cell is stopped and the supply of the oxidant gas to the cathode 52b is stopped, the oxygen concentration in the vicinity of the cathode 52b is likely to increase thereafter. Specifically, since the amount of oxygen remaining in the gas supply path 55 increases according to the volume of the gas phase, the oxygen concentration in the vicinity of the cathode 52b is low immediately after the operation is stopped. However, thereafter, the oxygen concentration in the vicinity of the cathode 52b is relatively likely to occur due to the diffusion of oxygen from the gas supply path 55 side and the backflow of air from the gas discharge path 58.
On the other hand, the latter fuel cell has a structure in which the gas supply path 55 connected to the cathode 52b has a small gas phase volume or a gas discharge path 58 provided with a valve for preventing air backflow. It is a battery. In the fuel cell having such a structure, when the operation of the fuel cell is stopped and the supply of oxygen to the cathode 52b is stopped, the oxygen concentration in the vicinity of the cathode 52b hardly increases thereafter. Specifically, since the amount of oxygen remaining in the gas supply path 55 is reduced according to the gas phase volume, even if oxygen diffusion from the gas supply path 55 side to the vicinity of the cathode 52b occurs. The degree of increase in oxygen concentration in the vicinity of the cathode 52b is low.

  Even if oxygen is present in the vicinity of the cathode 52b during shutdown, the oxygen in the vicinity of the cathode 52b is transferred to the anode 52a through the electrolyte 52c as long as the hydrogen-containing gas is filled in the vicinity of the anode 52a. However, since the hydrogen in the vicinity of the anode 52a enters the cathode 52b through the electrolyte 52c, the oxidation (deterioration) of the anode 52a is suppressed. Alternatively, even if oxygen in the vicinity of the cathode 52b enters the anode 52a through the electrolyte 52c, it is consumed by reacting with hydrogen existing in the vicinity of the anode 52a, so that oxidation (deterioration) of the anode 52a is suppressed. The For example, when the fuel gas generation device 51 for generating hydrogen used as the fuel gas of the fuel cell FC is connected to the fuel cell FC, the fuel gas generation device 51 to the anode 52a of the fuel cell FC during the operation stop. If the gaps are sealed together, a large amount of hydrogen is present in the sealed space, so that it is possible to maintain a state in which hydrogen remains in the vicinity of the anode 52a for a long period of time. As a result, oxidation of the anode 52a is prevented.

  However, when the fuel cell FC is intermittently operated as described above, when the fuel cell FC is stopped for a long period of time, hydrogen remaining between the fuel gas generation device 51 and the anode 52a of the fuel cell FC It gradually decreases by entering the cathode 52b side or by consuming oxygen that has entered the anode 52a side. Therefore, if the fuel cell has a structure in which the oxygen concentration in the vicinity of the cathode 52b is likely to increase during the operation stop, the oxygen concentration in the vicinity of the cathode 52b cannot be lowered sufficiently, and the cathode 52b to the anode 52a. Oxidation (deterioration) of the anode 52a due to oxygen intrusion may occur.

Note that if the operation control device 5 performs operation control so that the fuel cell FC is not stopped for a long period of time, that is, when the intermittent operation of the fuel cell FC is performed, control for shortening the period during which the operation stop state continues is performed. If it is the operation control apparatus 5 to perform, the above problems will not arise.
However, since the operation control device 5 is a general-purpose device used for various fuel cells, it is problematic to uniformly perform operation control for all fuel cells so that the fuel cell is not stopped for a long period of time. It is. For example, if the fuel cell has a structure in which the oxygen concentration in the vicinity of the cathode 52b does not easily increase during the operation stop as described above, the oxygen concentration in the vicinity of the cathode 52b can be maintained sufficiently lowered for a long period of time. Intermittent operation should be selected so that the operation stop state continues for a long time in consideration of energy saving, economic efficiency, environmental performance, and the like. However, if all fuel cells are uniformly controlled so that the operation stop state of the fuel cell is limited to a short time, a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b hardly increases during the operation stop. In addition, since the operation stop state is limited to be shorter than necessary, there is a possibility that energy saving, economic efficiency, environmental performance and the like are deteriorated.

Therefore, in the present embodiment, the operation control device 5 controls the operation of fuel cells having various structures in a preferable manner from the viewpoints of energy saving, economic efficiency, environment, and the like while avoiding deterioration of the cells 52. In addition, operation control is performed according to information on the characteristics of the fuel cell.
Here, whether or not the deterioration of the cell 52 can be avoided depends on how the operation control device 5 operates the fuel cell. For example, in the case of a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b is likely to increase during the stop of operation, when a long time elapses after the operation of the fuel cell is stopped, the fuel gas generating device 51 changes the fuel cell FC. The hydrogen remaining until the anode 52a enters the cathode 52b side or is used to consume oxygen that has entered the anode 52a side, and gradually decreases and is near the cathode 52b. As the amount of oxygen increases at this point, oxygen easily enters the anode 52a from the cathode 52b. That is, in order to achieve the purpose of avoiding the deterioration of the cell 52, in the case of a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b is likely to increase during operation stop, the continuous operation stop period of the fuel cell is The shorter one is preferable.
On the other hand, in the case of a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b is difficult to increase during the operation stop, the oxygen in the vicinity of the cathode 52b even after a long time has passed since the operation of the fuel cell was stopped. Since the amount is small, oxygen hardly enters the anode 52a from the cathode 52b. In other words, in order to achieve the purpose of avoiding the deterioration of the cell 52, in the case of a fuel cell having a structure in which the oxygen concentration in the vicinity of the cathode 52b is difficult to increase during the shutdown, the continuous shutdown period of the fuel cell FC The length is not a big problem.

In the present embodiment, when the fuel cell FC is installed, the operation control device 5 acquires information indicating what characteristics the fuel cell FC has and stores the information in the memory 5a as a storage unit.
Specifically, when the operation control device is installed together with the fuel cell FC, the operation control device obtains time index information specific to the fuel cell FC that represents an allowable stop period in which the fuel cell FC can be continuously maintained in the operation stop state. And stored in the memory 5a. This permissible stop period is set in such a relationship that it is set shorter as the oxygen concentration in the vicinity of the cathode 52b of the fuel cell FC during operation stop tends to increase. And the control part 5b of the driving | operation control apparatus 5 has few appearance frequency of the long-term stop state continuously stopped for a period longer than the said permissible stop period according to the time index information acquired and memorize | stored in the memory 5a. Thus, the operation of the fuel cell FC is controlled. In the present embodiment, the control unit 5b of the operation control device 5 sets the operation mode determination target period of the fuel cell FC, which will be described later, to a length equal to or shorter than the allowable stop period.
The allowable stop period as the time index information may vary depending on the device configuration of the fuel cell FC, but is information in a form for specifying a time such as 36 hours. In the present embodiment, the allowable stop period is determined based on the period until the oxygen concentration in the vicinity of the cathode 52b becomes equal to or higher than the set level, which is obtained in advance by experimental results.

  With such a setting, even if the operation of the fuel cell FC is stopped during the entire operation mode determination target period, the operation stop period that continuously occurs within one operation mode determination target period is equal to or less than the allowable stop period. . Note that there is a possibility that the fuel cell FC is continuously stopped for a length equal to or longer than the allowable stop period over two continuous operation mode determination target periods. However, even if the intermittent operation mode is selected, a long-term stop state in which the operation is continuously stopped for a period longer than the allowable stop period does not appear within at least one operation mode determination target period (or at least even if the standby mode is selected). Within a single operation mode determination target period, a long-term stop state in which the operation is continuously stopped for a period longer than the allowable stop period does not appear). As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.

  Then, the operation control device 5 has a time-series predicted power load, a time-series predicted heat load, a time-series predicted power load at the start of the operation mode determination target period of the fuel cell FC set to a length equal to or shorter than the allowable stop period. Energy consumption due to operation of the fuel cell FC (hereinafter sometimes referred to as energy consumption during operation), energy consumption during startup when the fuel cell FC is started, and energy consumption during stop when the fuel cell FC is stopped On the basis of the power consumption during standby and the operating mode determination target period, the operating merit derived when the fuel cell FC is assumed to be continuously operated is determined as the continuous operation merit, and the operation mode determining target Assuming that the fuel cell FC is intermittently operated with a part of the period as an operation period and the remaining period as a non-operation period, the above operation period and Executing the operating benefits arithmetic processing to determine the most larger operating benefits when deriving the operating benefits while changing the combination of the non-operating time period as intermittent operation benefits. In addition, in the driving merit calculation process, the driving control device 5 can determine the driving merit when it is assumed that the fuel cell FC is stopped and the driving is waited in the entire time period of the driving mode determination target period as the standby merit. In the present embodiment, the largest driving merit is determined as the intermittent driving merit, but it is not limited to determining the largest driving merit as the intermittent driving merit. For example, the second largest or the third largest driving merit may be modified so as to be determined as the intermittent driving merit.

  Then, the operation control device 5 sets the operation mode (corresponding to the operation mode) of the fuel cell FC based on the selection conditions based on the continuous operation merit and the intermittent operation merit determined in the operation merit calculation process. The operation mode setting process defined in either the operation mode) or the intermittent operation mode (corresponding to the intermittent operation mode) is executed. In the present embodiment, the selection condition is set to a condition that sets the operation mode of the fuel cell FC to the operation mode corresponding to the higher one of the continuous operation merit and the intermittent operation merit. The operation control device 5 operates the fuel cell FC in the operation mode determined by the operation mode setting process. Further, when considering the above-described standby merit in the operation mode setting process, the operation control device 5 sets the operation mode of the fuel cell FC to the standby mode (standby mode) based on the standby merit, the continuous operation merit, and the intermittent operation merit as described later. (Corresponding to the form), and can be set to either a continuous operation mode or an intermittent operation mode.

  The startup energy consumption is required to warm up the reformer 51a and the carbon monoxide remover (not shown) constituting the fuel gas generation device 51 to temperatures set so that they can be processed respectively. Includes energy. The energy consumption at the time of stop is the energy required for sealing the gas flow path of the fuel gas generation device 51 with a gas containing hydrogen when stopping the fuel cell FC, specifically, a fan, a pump, a valve, etc. Including energy for driving.

  In the following description, the operation cycle is set to one day, the operation mode determination target period is composed of two consecutive operation cycles, and the operation cycle is composed of a plurality of unit times, and the unit time Is set to 1 hour. The operation merit is the amount of energy reduction by operating the fuel cell FC. The operation mode determination target period is set to a length equal to or shorter than the allowable stop period as described above.

  In the present embodiment, the control unit 5b indicates the continuous operation merit when it is assumed that the fuel cell FC is continuously operated in the operation merit calculation process. The fuel cell FC is in operation at the start time of the operation mode determination target period. Regardless of whether or not there is a driving merit when it is configured to be calculated in a form that does not consume energy at startup, and the time period following the start point of the period for determining the driving mode is assumed as the driving time zone Regardless of whether or not the fuel cell FC is in operation at the start of the operation mode determination target period, the time period in which the driving merit is greatest is determined in the form in which the energy consumption at startup is maximized. Find the merit of intermittent operation when assumed as a belt.

  Further, when the control unit 5b is configured to manage the predicted power load and the predicted heat load by dividing each of a plurality of operation cycles constituting the operation mode determination target period, and when the fuel cell FC is continuously operated, It is configured to obtain the continuous operation merit when assumed based on the predicted power load and the predicted heat load of the first operation cycle of the plurality of operation cycles in a form that does not consume the energy consumption at the time of the stop, and In the form of setting one operation time zone in the first operation cycle, it is determined in the first operation cycle so that the operation merit obtained based on the predicted power load and the predicted heat load in the first operation cycle is the highest. Operating merits for the different operating hours, and predicted power load and predicted heat load of the first operation cycle, and predicted heat negative of the operation cycle following the first operation cycle of the plurality of operation cycles. The driving merit of the higher driving merit for the driving time zone determined in the first driving cycle so that the driving merit obtained based on the highest driving merit is the driving time zone when the driving merit is highest It is calculated as the merit of intermittent operation.

  Further, when the control unit 5b sets the operation mode of the fuel cell FC to the intermittent operation mode at the start of the operation mode determination target period, an operation time zone setting process for setting the operation time zone of the intermittent operation mode is executed. The operation time zone setting process is configured to set one operation time zone in the intermittent operation mode within the first operation cycle, and continues to the start time of the operation mode determination target period. The operating merit when assuming the time zone as the driving time zone is that the fuel cell FC is not operating when the fuel cell FC is operating at the start of the operation mode determination target period, and the fuel cell FC is stopped. In some cases, the energy consumption at startup is required to be consumed, and the operation merit obtained based on the predicted power load and predicted heat load in the first operation cycle is used. Operating merits determined based on the highest operating hours, the predicted power load and predicted thermal load of the first operating cycle, and the predicted thermal load of the operating cycle following the first operating cycle of the multiple operating cycles The driving time zone with the highest driving merit is set as the driving time zone in the intermittent operation mode.

  That is, since the operation time zone in the intermittent operation mode is set to one in the first operation cycle among the plurality of operation cycles constituting the operation mode determination target period, in the intermittent operation mode, the operation mode determination target period is set. During this period, the fuel cell FC is stopped once, so that the intermittent operation merit is required in the form of consuming energy at the time of stop.

  In the intermittent operation mode, a mode in which the operation time zone is determined within the first operation cycle so that the operation merit obtained based on the predicted power load and predicted heat load of the first operation cycle is the highest is intermittent operation every day. The operation merit obtained based on the predicted power load and predicted heat load of the first operation cycle and the predicted heat load of the operation cycle subsequent to the first operation cycle of the plurality of operation cycles is the highest. In some cases, the mode in which the operation time zone is determined within the first operation cycle is described as an intermittent operation mode every two days.

  Further, the operation control device 5 updates the operation mode determination target period configured by a plurality of operation cycles at each start point of the operation cycle, and executes the operation mode setting process at each start point of the operation cycle. It is configured as follows.

  Further, the operation control device 5 manages the standby merit when it is assumed that the fuel cell FC is stopped and the operation is waited in the entire time period of the operation mode determination target period, and the managed standby merit and continuous Based on the operation merit and the intermittent operation merit, the operation mode of the fuel cell FC is determined to be any one of the standby mode (corresponding to the standby mode), the continuous operation mode, and the intermittent operation mode.

[Operation mode setting process]
Below, the detail of the operation mode setting process which the control part 5b of the operation control apparatus 5 performs is demonstrated.
First, time-series past power load data and time-series past heat load data are managed, and time-series predicted power load data and time-series predicted heat load data are obtained based on the management data. Data management processing will be described. In the present embodiment, the heat load is obtained as a combination of the hot water supply heat load when hot water is supplied to the hot water supply unit 3A and the terminal heat load at the heat consuming terminal 3B.
The control unit 5b stores the actual power load data, the actual hot water supply thermal load data, and the actual terminal thermal load data in association with the operation cycle and unit time in the nonvolatile memory 5a. Accordingly, the control unit 5b stores the past time-series power load data and the past time-series heat load data for each unit time for each operation cycle over a set period (for example, four weeks before the operation day). A plurality of operations that constitute the operation form determination target period based on the past time-series power load data and the management data of the heat load data, and the predicted power load data and the predicted heat load data. It can be managed by dividing each period.

  However, in the present embodiment, the predicted power load data is managed only for the first operation cycle of the plurality of operation cycles constituting the operation form determination target period, and the predicted heat load data is a plurality of pieces constituting the operation form determination target period. All of the operation cycles are divided into operation cycles and managed. The actual power load is measured based on the measured value of the power load measuring means 11 and the output value of the inverter 6, the actual hot water supply thermal load is measured by the hot water supply thermal load measuring means 31, and the actual terminal thermal load is measured by the terminal thermal load measurement. It is measured by means 32.

Then, at the start time of the operation mode determination target period (corresponding to the start time of each operation cycle (for example, 3 am)), the control unit 5b performs time-series past power load data and time-series past heat load. Based on the management data of the data, time-series predicted power load data and time-series predicted heat load data of the first operation cycle of the plurality of operation cycles constituting the operation mode determination target period, and a plurality of operation cycles Time-series predicted thermal load data of an operation cycle (hereinafter, sometimes referred to as a second operation cycle) subsequent to the first operation cycle is obtained for each unit time and stored in the memory 5a. It is configured as follows.
For example, as illustrated in FIG. 4, the control unit 5 b is configured to obtain the predicted power load data and the predicted heat load data of the first operation cycle every unit time at the start of the operation mode determination target period. .

[Operation merit calculation processing]
Next, an operation merit calculation process for calculating the predicted energy reduction amount in the continuous operation mode as the continuous operation merit and the predicted energy reduction amount in the intermittent operation mode as the intermittent operation merit will be described. The controller 5b obtains a predicted energy reduction amount in the load following continuous operation mode and a predicted energy reduction amount in the suppression continuous operation mode as the predicted energy reduction amount in the continuous operation mode.
The predicted energy reduction amount in the load following continuous operation mode is predicted when it is assumed that the main operation for causing the generated power of the fuel cell FC to follow the predicted power load is executed in all time periods of the operation mode determination target period. It is energy saving amount.
The predicted energy reduction amount in the suppression continuous operation mode is the generation of the fuel cell FC with respect to the predicted heat load when it is assumed that the main operation is performed to follow the predicted power load in all time periods of the operation mode determination target period. When a surplus heat state with excess heat is predicted, it is assumed that the output of the fuel cell FC is set to a suppressed output smaller than the main output following the predicted power load in a part of the operation mode determination target period. This is the predicted energy reduction amount.

  The surplus heat state is, for example, a state where hot water stored in the hot water tank 2 is full and the radiator 19 is operated, or the heat output from the fuel cell FC during the heat medium supply operation is the heat consuming terminal 3B. The hot water stored in the hot water tank 2 is full, and the radiator 19 is in operation. The control unit 5b obtains the predicted power load and the predicted heat load in the operation cycle, and assumes that the main operation is continuously performed in response to the predicted power load, and the generated heat of the fuel cell FC is predicted heat. It is determined whether or not a surplus heat state occurs with respect to the load, and a time zone in which the surplus heat state occurs is determined as a surplus heat time zone.

When the fuel cell FC is operated, the control unit 5b obtains the current power load currently requested at a relatively short predetermined output adjustment period such as 1 minute or less, and the maximum output (for example, 300 W) to the maximum output (for example, 300 W). For example, within a range of 1000 W), the main output that continuously follows the current power load is determined, and the generated power of the fuel cell FC is adjusted to the determined main output so that the power that follows the current power load is adjusted. Perform main operation. The current power load is measured based on the measured value of the power load measuring means 11 and the output value of the inverter 6, and the current power load is sampled at a predetermined sampling time (for example, 5 seconds) in the previous output adjustment period. Is obtained as an average value of the measured data.
In the intermittent operation mode, the control unit 5b performs the main operation when operating the fuel cell FC.

The control unit 5b is configured to be able to calculate a predicted energy reduction amount that is an energy reduction amount for the predicted power load and the predicted heat load with respect to a temporary operation pattern of a certain fuel cell FC.
That is, the control unit 5b assumes that the main operation is performed with respect to the predicted power load in a mode in which the fuel cell FC is operated in the operation time period in the preset temporary operation pattern, and the time series of the fuel cell FC is performed. Calculate the predicted generated power and the predicted generated heat. Then, as shown in Equation 2 below, the control unit 5b uses the energy consumption amount when the fuel cell FC is not operated as a reference, and the reduction amount of the energy consumption amount when the fuel cell FC is operated in the temporary operation pattern. Calculated as the predicted energy reduction amount.

Predicted energy reduction amount P = energy consumption amount E1 when the fuel cell FC is not operated E1-energy consumption amount E2 when the fuel cell FC is operated (formula 2)

  The energy consumption E1 when the fuel cell FC is not operated is predicted as the energy consumption in the commercial power supply 7 when all of the predicted power load is covered by the received power from the commercial power supply 7, as shown in the following formula 3. It is obtained as the sum of the energy consumption when all the heat load is covered by the heat generated by the auxiliary heater 28.

E1 = predicted power load / power generation efficiency of commercial power supply 7 + predicted heat load / heat generation efficiency of auxiliary heater 28 (Equation 3)

  On the other hand, the energy consumption E2 when the fuel cell FC is operated is the consumption during operation that is the energy consumption of the fuel cell FC when the predicted power load and the predicted heat load are covered by the predicted generated power and the predicted generated heat of the fuel cell FC. Of energy and energy consumption in the commercial power source 7 when the received power from the commercial power source 7 covers an insufficient power load corresponding to the subtraction of the predicted generated power from the predicted power load, and the predicted heat generated from the predicted heat load When energy consumption at start-up is consumed in addition to the energy consumption in the case where an insufficient heat load corresponding to the amount obtained by subtracting the predicted heat amount used as the predicted heat load is covered by the heat generated by the auxiliary heater 28 Is calculated by adding the energy consumption at the time of stoppage and adding the energy consumption at the time of stoppage.

  That is, in the present embodiment, the predicted energy reduction amount in the continuous operation mode as the merit of continuous operation is related to whether or not the fuel cell FC is in operation at the start of the operation mode determination target period, as described above. Therefore, the energy consumption amount E2 when the fuel cell FC is operated in the continuous operation mode is obtained by the following equation 4 so that the energy consumption at the start is not consumed and the energy consumption at the stop is not consumed. As shown in FIG. 4, the energy consumption is calculated by a calculation formula for non-consumption of both the starting and stopping energy without adding both the starting energy consumption and the stopping energy consumption.

E2 = Energy consumption during operation + Insufficient power load / Power generation efficiency of commercial power supply 7 + Insufficient heat load / Heat generation efficiency of auxiliary heater 28 (Equation 4)

  In the present embodiment, as described above, the predicted energy reduction amount in the intermittent operation mode as the merit of the intermittent operation is related to whether or not the fuel cell FC is in operation at the start of the operation mode determination target period. First, it is calculated in such a manner that energy consumption at startup is consumed and energy consumption at stop is consumed. Accordingly, the energy consumption amount E2 when the fuel cell FC is operated in the intermittent operation mode is obtained by adding both the starting energy consumption and the stopping energy consumption, as shown in Equation 5 below. It is obtained by a calculation formula for consumption.

E2 = Energy consumption during operation + Insufficient power load / Power generation efficiency of commercial power supply 7 + Insufficient heat load / Heat generation efficiency of auxiliary heater 28 + Energy consumption at start-up + Energy consumption at stop ... (Formula 5)

  The starting energy consumption and stopping energy consumption of the fuel cell FC are values inherent to the fuel cell FC, and are obtained in advance by experiments or the like and stored in the memory 5a. For example, the starting energy consumption is set to 1900 Wh, and the stopping energy consumption is set to 200 Wh.

[Calculation of predicted energy reduction amount P]
Next, a method for obtaining the above-described predicted energy reduction amount P will be described.
As shown in FIG. 6, all of the temporary operation patterns for setting one operation time zone within the first operation cycle among the plurality of operation cycles constituting the operation form determination target period are stored in the memory 5 a. The temporary operation pattern includes an operation time zone and a non-operation time zone.

  For example, if the starting point of the driving mode determination target period (driving mode setting processing timing) is 3:00 am, the pattern starting operation from 3:00 am to 4:00 am (unit time 1) is 3:00 am Pattern 1 (start-up time is 3:00 am, stop time is 4:00 am) and time zone from 3:00 am to 5:00 am (unit time) with the time of 4 am (unit time “1”) as the operation time zone “2”) is a driving time zone pattern 2 (start-up time is 3 am, stop time is 5 am), time zone from 3 am to 6 am (unit time “1”, “ 2 ”and“ 3 ”) as a driving time zone 3... Pattern from 3 am to 3 am the next day as a driving time zone (unit time“ 1 ”to“ 24 ”) There are 24 types of 24. In addition, as a pattern for starting operation from 4:00 am to 5:00 am (unit time “2”), a pattern 25 having this unit time “2” as an operation time zone, a time zone from 4 am to 6 am Pattern 26 with operation time zone (unit time “2” and “3”)... 4:00 am to 3 am on the next day (unit time “2” to “24”) There are 23 types of patterns 47 as bands. In this way, up to the pattern 300 using the time zone (unit time “24”) from 2:00 am to 3:00 am at the end of the driving cycle as the driving time zone, there are 300 types of temporary driving patterns from the pattern 1 to the pattern 300. There are things.

  As shown in FIG. 5, the predicted power load (a) and the predicted heat load (m) are obtained for each of 24 unit times in the first operation cycle in the operation mode determination target period, and further, the operation mode determination target period. Is calculated for each unit time in the operation period subsequent to the first operation period, and the fuel cell FC is calculated for each unit time included in the operation time zone set in the temporary operation pattern. Is obtained in a form that follows the predicted power load (a). When the predicted power load is less than or equal to the minimum output of the fuel cell FC, the main output (b) is set to the minimum output and the difference is obtained as the surplus power (i). On the other hand, when the predicted power load is greater than or equal to the maximum output of the fuel cell FC, the main output (b) is set to the maximum output and the difference is obtained as the insufficient power amount (c).

By dividing the main output (b) by the power generation efficiency (e) of the fuel cell FC in each unit time included in the operation time zone, the operating energy consumption (the primary energy consumption amount of the fuel cell FC) ( g) and the amount of generated heat (d) of the fuel cell FC is obtained by multiplying the energy consumption during operation (g) and the heat generation efficiency (f) of the fuel cell FC.
In each unit time other than the operation time zone, the main output (b) is set to 0, so that the operating energy consumption (g) and the generated heat quantity (d) are 0.

  Furthermore, in each unit time of the first operation cycle, within the range not more than the maximum capacity of the hot water tank 2, the amount of heat generated (d) minus the exhaust heat loss (h) is integrated, Further, the amount of heat generated by the electric heater 12 obtained from the surplus electric energy (i) is added to the hot water storage heat dissipation amount (l) radiated in the hot water storage tank 2 and the predicted use used as the predicted heat load (m). The amount obtained by subtracting the amount of heat (n) is determined as the amount of stored hot water (k) stored in the hot water tank 2, and the amount of heat exceeding the maximum capacity of the hot water tank 2 is surplus heat (j ) However, the amount of stored hot water at the start of the operation mode determination target period is based on the detected temperatures of the upper end temperature sensor S1, the intermediate upper temperature sensor S2, the intermediate lower temperature sensor S3, the lower end temperature sensor S4, and the feed water temperature sensor Si. It is calculated | required based on Formula 1 of these.

  Further, for each unit time of the operation cycle subsequent to the first operation cycle, a state in which the amount of stored hot water (k) in the final unit time in the first operation cycle is continuously used as the predicted heat load (m). Assuming that the amount of hot water stored in the previous unit time (k) is subtracted from the amount of heat released from the hot water (l) and the predicted amount of heat used (n) used as the predicted heat load (m), the next unit Calculated as the amount of hot water stored in time (k).

[Predicted energy reduction amount P in load following continuous operation mode]
The predicted energy reduction amount P in the load following continuous operation mode is obtained as follows.
First, the energy consumption E2 when the fuel cell FC is operated in the load following continuous operation mode is assumed to be the operation in the first operation cycle, assuming that the main operation is performed to follow the predicted power load over the entire time period of the operation cycle. The sum of the hourly energy consumption (g), the sum of the shortage electric energy (c), and the sum of the shortage heat load obtained as the difference between the predicted heat load (m) and the predicted heat consumption (n) It is obtained by substituting into the calculation formula for non-consumption of both energy at start / stop.
Further, based on the predicted power load and the predicted heat load of the first operation cycle, the energy consumption E1 when the fuel cell FC is not operated is obtained by Expression 3.
Then, by substituting the energy consumption amount E1 when the fuel cell FC is not operated and the energy consumption amount E2 when the fuel cell FC is operated, which are obtained as described above, into Formula 2, prediction in the load following continuous operation mode is performed. An energy reduction amount P is obtained.

[Predicted energy reduction amount P in the suppression continuous operation mode]
The predicted energy reduction amount P in the suppressed continuous operation mode is obtained as follows.
First, the energy consumption amount E2 when the fuel cell FC is operated in the suppression continuous operation mode is obtained as follows.
In the form of setting one suppression time zone in which the output of the fuel cell FC is set to a suppression output smaller than the main output following the predicted power load before the heat surplus time zone in the first operation cycle, in multiple stages As described above, the sum of the energy consumption during operation (g) and the sum of the deficient electric energy (c) for each of all the temporary operation patterns for suppression formed with different set suppression outputs and suppression time zones. And the sum of the shortage heat load obtained as the difference between the predicted heat load (m) and the predicted heat consumption (n) is substituted into the equation for non-energy consumption at both start and stop of Equation 4. As a result, the energy consumption amount E2 is obtained for each of the temporary operation patterns for suppression, and it is determined whether or not there is a surplus heat time zone in which a surplus heat state occurs.
Further, based on the predicted power load and the predicted heat load in the first operation cycle, the energy consumption E1 when the fuel cell FC is not operated is obtained by Equation 3.
The energy consumption amount E1 when the fuel cell FC is not operated and the energy consumption amount when the fuel cell FC is operated are obtained as described above for each of the suppression temporary operation patterns in which no excess heat time zone occurs. By substituting E2 into Equation 2, the predicted energy reduction amount P is obtained, and the largest of the obtained predicted energy reduction amounts P is set as the predicted energy reduction amount P in the suppression continuous operation mode.

[Predicted energy reduction P in intermittent operation mode]
The predicted energy reduction amount P in the intermittent operation mode is obtained as follows.
For each of all the temporary operation patterns stored in the memory 5a, the fuel cell FC was operated on the assumption that the main operation was performed to follow the predicted power load in the operation time zone set in each temporary operation pattern. Energy consumption amount E2 in the case, the difference between the total energy consumption (g) during operation and the total shortage power amount (c) in the first operation cycle, and the predicted heat load (m) and the predicted usage heat amount (n) Is calculated by substituting the sum of the insufficient heat loads obtained as follows into the calculation formula for energy consumption at both start and stop in Equation 5.
Based on the predicted power load and the predicted heat load of the first operation cycle, the energy consumption E1 when the fuel cell FC is not operated is obtained by Equation 3.
For each of the temporary operation patterns, prediction is performed by substituting the energy consumption amount E1 when the fuel cell FC is not operated and the energy consumption amount E2 when the fuel cell FC is operated as described above into Equation 2. The energy reduction amount P is obtained, and the largest of the obtained predicted energy reduction amounts P is set as the predicted energy reduction amount in the daily intermittent operation mode.

Further, for all of the temporary operation patterns stored in the memory 5a, the predicted energy reduction amount P obtained for each of the temporary operation patterns is calculated by adding the total of the predicted use heat amount (n) in the operation cycle subsequent to the first operation cycle to the auxiliary heater 28. By dividing the value obtained by adding the energy consumption when covered by the generated heat by 2 which is the number of operation cycles constituting the operation mode determination target period, the predicted energy reduction amount per operation cycle (one day) is obtained. The largest of the calculated predicted energy reduction amounts is set as the predicted energy reduction amount P in the intermittent operation mode every two days.
Then, the larger one of the predicted energy reduction amount P in the daily intermittent operation mode and the predicted energy reduction amount P in the 2-day intermittent operation mode is obtained as the predicted energy reduction amount P in the intermittent operation mode.

By the way, even if the fuel cell FC is stopped, energy (electric power) is consumed, for example, to keep it in a state where power generation is possible, and the fuel cell FC is used in all time zones within the operation cycle. The energy consumed in the cogeneration system 1 when the power is stopped is determined as the standby energy consumption Z in advance through experiments or the like.
The predicted energy reduction amount in the load following continuous operation mode, the predicted energy reduction amount in the suppression continuous operation mode, and the predicted energy reduction amount in the intermittent operation mode may be obtained as negative values.
For example, when the predicted energy reduction amount in the load following continuous operation mode obtained as a negative value is larger than the negative value of the standby energy consumption Z, the fuel cell FC is set in the load following continuous operation mode. Driving is more energy-saving than waiting for driving, and conversely, the predicted energy reduction amount in the load following continuous operation mode obtained as a negative value is smaller than the negative value of standby energy consumption Z Since it is more energy saving to wait for the operation than to operate the fuel cell FC in the load following continuous operation mode, the standby energy consumption Z can be used as a standby merit.
Therefore, the standby energy consumption Z is stored in the memory 5a of the operation control device 5 as a standby merit. That is, the control unit 5b is configured to manage the standby energy consumption Z as a standby merit.

In the present embodiment, the standby energy consumption Z can be obtained by the following equation, for example.
Z = power consumption during standby × standby time / power generation efficiency of commercial power supply 7

  And the control part 5b is the largest among the prediction energy reduction amount in the load follow-up continuous operation mode calculated | required as mentioned above, the prediction energy reduction amount in the suppression continuous operation mode, and the prediction energy reduction amount in the intermittent operation mode. If the energy consumption is larger than the negative value of the standby energy consumption Z, the predicted energy reduction amount in the load following continuous operation mode, the predicted energy reduction amount in the suppression continuous operation mode, and the predicted energy reduction amount in the intermittent operation mode The operation mode of the fuel cell FC is determined in the operation mode corresponding to the one with the maximum predicted energy reduction amount, or the predicted energy reduction amount in the load following continuous operation mode, the predicted energy reduction amount in the suppression continuous operation mode If the maximum of the predicted energy reduction amount in the intermittent operation mode is less than the negative value of the standby energy consumption Z, the fuel cell FC Rolling determines the mode to the standby mode.

FIG. 8 shows the results of obtaining the predicted energy reduction amount in the continuous operation mode and the predicted energy reduction amount in the intermittent operation mode in accordance with the thermal load in a state where the power load is a set amount.
In FIG. 8, Lc1 is obtained by calculating the predicted energy reduction amount in the continuous operation mode as not consuming the starting energy consumption and the stopping energy consumption, and Lc2 is activated the estimated energy reduction amount in the continuous operation mode. This is obtained by consuming the time consumption energy and the stop time energy consumption.
In FIG. 8, Li1 is obtained by calculating the predicted energy reduction amount in the intermittent operation mode as not consuming the starting energy consumption and the stopping energy consumption, and Li2 is the predicted energy reduction amount in the intermittent operation mode. Is calculated as consuming energy consumption at start-up and energy consumption at stop.

As shown by Lc1 and Li2 in FIG. 8, the predicted energy reduction amount in the continuous operation mode is obtained as not consuming the starting energy consumption and the stopping energy consumption, and the predicted energy reduction amount in the intermittent operation mode is calculated as the starting energy consumption. If the predicted heat load is Q or more, the predicted energy reduction amount in the continuous operation mode becomes equal to or more than the predicted energy reduction amount in the intermittent operation mode, and the fuel cell FC When the operation mode is set to the continuous operation mode and the predicted heat load is smaller than Q, the predicted energy reduction amount in the intermittent operation mode becomes larger than the predicted energy reduction amount in the continuous operation mode, and the fuel cell FC The operation mode is set to the intermittent operation mode.
However, as can be seen from Lc1, Lc2, Li1, and Li2 in FIG. 8, when the predicted energy reduction amount in the continuous operation mode is determined as consuming the energy consumption at startup and the energy consumption at stop, the predicted energy in the intermittent operation mode is obtained. Regardless of whether the energy consumption at startup and energy consumption at stop are calculated or not, the predicted energy reduction in the continuous operation mode is the predicted energy reduction in the intermittent operation mode. The operation mode of the fuel cell FC is not set to the continuous operation mode.

  Accordingly, the merit of continuous operation when assuming that the fuel cell FC is continuously operated is that energy consumption at start-up is not consumed regardless of whether or not the fuel cell FC is operating at the start of the operation mode determination target period. Whether or not the fuel cell FC is in operation at the start of the operation form determination target period, assuming that the operation time period is assumed to be the time period following the start time of the operation form determination target period. Regardless of whether or not it is assumed that the energy consumption at start-up is consumed, the expected power load is calculated by determining the intermittent operation merit when the operation time zone is assumed as the time when the driving merit is highest. When the predicted heat load is in a state where the operation mode of the fuel cell FC should be set to the continuous operation mode, the operation mode of the fuel cell FC is The will be able to as defined in the continuous operation mode, the operation mode of the fuel cell FC can appropriately determine that any of the continuous operation mode and intermittent operation mode.

  In this embodiment, Lc1 in FIG. 8 shows the result of obtaining continuous operation merit as not consuming energy at stop, and Li2 shows the result of obtaining intermittent operation merit as consuming energy at stop. The energy consumption at the time of stop is considerably smaller than the energy consumption at the time, and the influence on the calculated value of the driving merit is small depending on whether the energy consumption at the time of stop is consumed or not. Therefore, in obtaining each of the benefits of continuous operation and intermittent operation, even if the handling of energy consumption during stoppage is changed, the continuous operation merit obtained in the form that the energy consumption during startup is not consumed and the energy consumption during startup are calculated. The relationship with the intermittent operation merit obtained in the form of consumption is similar to the relationship between Lc1 and Li2 in FIG. Therefore, as described above, when the predicted power load and the predicted heat load are in a state where the operation mode of the fuel cell FC should be set to the continuous operation mode, the operation mode of the fuel cell FC can be set to the continuous operation mode.

[Operation time zone setting process]
Next, an operation time zone setting process that is executed when the operation mode of the fuel cell FC is set to the intermittent operation mode will be described.
That is, as a calculation formula for obtaining the energy consumption amount E2 when the fuel cell FC is operated, as shown in the following formula 6, the startup consumption energy is not added and the startup consumption energy is not added / stopped. An arithmetic expression for consumption is set.

E2 = Energy consumption during operation + Insufficient power load / Power generation efficiency of commercial power source 7 + Insufficient heat load / Heat generation efficiency of auxiliary heater 28 + Energy consumption during stop (Equation 6)

When the fuel cell FC is in operation at the start of the operation mode determination target period, a unit time equal to or greater than the set number N1 (for example, 2) in the temporary operation pattern stored in the memory 5a is set as the operation time zone. Of all the temporary operation patterns, for each of the temporary operation patterns that assume the time period following the start time of the operation mode determination target period as the operation time period, the energy consumption amount E2 when the fuel cell FC is operated is expressed by Equation 6. The energy consumption amount E2 when the fuel cell FC is operated is calculated by the calculation formula for non-consumption at start-up / consumption at stop, and for each of the temporary operation patterns. Obtained by the following equation.
Further, when the fuel cell FC is stopped at the start of the operation mode determination target period, all the temporary operation patterns in which the unit time of the set number N1 or more in the temporary operation pattern stored in the memory 5a is the operation time zone. For each of the above, the energy consumption amount E2 when the fuel cell FC is operated is obtained by the calculation formula for both energy consumption at startup / stop of Equation 5.
Based on the predicted power load and the predicted heat load of the first operation cycle, the energy consumption E1 when the fuel cell FC is not operated is obtained by Equation 3.

  When the fuel cell FC is not operated and the energy consumption amount E1 and the fuel cell FC are operated as described above for each of the temporary operation patterns in which the unit time of the set number N1 or more is the operation time zone. The estimated energy reduction amount P is obtained by substituting the energy consumption amount E2 into Equation 2, and the operation time zone of the maximum temporary operation pattern among the obtained predicted energy reduction amounts P is the operation time zone of the daily intermittent operation mode. And

Further, for each of all the temporary operation patterns in which the unit time equal to or greater than the set number N1 is the operation time zone, the predicted energy reduction amount P obtained for each of the temporary operation patterns is calculated as the predicted use heat amount (n ) Is added to the amount of energy consumed when the heat generated by the auxiliary heater 28 is used to divide the value by 2 which is the number of operation cycles constituting the operation mode determination target period, thereby predicting energy per operation cycle. The reduction amount P is obtained, and the operation time zone of the temporary operation pattern in which the obtained predicted energy reduction amount P is the maximum is set as the operation time zone of the intermittent operation mode every two days.
Of the operation time zone in the daily intermittent operation mode and the operation time zone in the 2-day intermittent operation mode, the operation time zone with the larger predicted energy reduction amount P is set as the operation time zone in the intermittent operation mode.

Next, the operation mode selection process will be described based on the flowchart shown in FIG.
As will be described in detail below, the control unit 5b of the operation control device 5 sets the operation mode set to a length equal to or shorter than the allowable stop period in steps # 1 to # 6, # 9, and # 16 of FIG. Derived when it is assumed that the fuel cell FC is continuously operated in all time periods of the operation mode determination target period based on the time-series predicted power load and the time-series predicted heat load at the start of the determination target period. When the fuel cell FC is intermittently operated with the operation time zone being determined as the operation time zone and the remaining time zone being set as the non-operation time zone. Assuming that the driving merit becomes the largest when the driving merit is derived while changing the combination of the driving time zone and the non-driving time zone, the intermittent driving merit is determined. Based on the determined continuous operation advantage, intermittent operation advantage, and standby advantage, the operation merit when it is assumed that the fuel cell FC is stopped and the operation is waited in all time periods of the target period is determined. The operation mode of the FC is determined as one of a continuous operation mode, an intermittent operation mode, and a standby mode. Here, even if the operation mode of the fuel cell FC is determined as the standby mode and the fuel cell FC is stopped in the entire time period of the operation mode determination target period, the operation mode determination target period is set to be equal to or less than the allowable stop period. Therefore, oxidation (deterioration) of the anode is suppressed.

The flowchart shown in FIG. 7 will be specifically described below.
The control unit 5b updates the driving mode determination target period so as to be configured with two driving cycles subsequent to the starting point every time the driving cycle starts (for example, 3:00 am). Executes mode selection processing.
In other words, each time the operation cycle starts, the data management process is executed as described above to obtain the predicted power load data and the predicted heat load data, and the operation merit calculation process is executed as described above to perform load tracking. The predicted energy reduction amount Pc1 in the continuous operation mode, the predicted energy reduction amount Pc2 in the suppression continuous operation mode, and the predicted energy reduction amount Pi in the intermittent operation mode are calculated, and the largest one of them is consumed during standby. By determining whether or not the energy Z is larger than the negative value “−Z”, it is possible to operate one of the load following continuous operation mode, the suppression continuous operation mode, and the intermittent operation mode. It is determined whether or not energy is saved as compared with the execution of the standby mode in which the fuel cell FC is stopped in all time periods of the cycle (steps # 1 to # 4).

  That is, when the load following continuous operation mode, the suppression continuous operation mode, and the intermittent operation mode are executed, the energy consumption is larger than the energy consumption when the fuel cell FC is not operated, and the prediction in the load following continuous operation mode is performed. The energy reduction amount Pc1, the predicted energy reduction amount Pc2 in the suppression continuous operation mode, and the predicted energy reduction amount Pi in the intermittent operation mode may be obtained as negative values. The largest of the predicted energy reduction amount Pc1 in the continuous operation mode, the predicted energy reduction amount Pc2 in the suppressed continuous operation mode, and the predicted energy reduction amount Pi in the intermittent operation mode is the negative value of the standby energy consumption Z “ When it is larger than “−Z”, it is better to execute one of the load following continuous operation mode, the suppression continuous operation mode, and the intermittent operation mode. Become energy-saving than to run the machine mode.

  When it is determined in step # 4 that the execution of any one of the load following continuous operation mode, the suppression continuous operation mode, and the intermittent operation mode saves energy compared to executing the standby mode, the process proceeds to step # 5. Of the predicted energy reduction amount Pc1 in the load following continuous operation mode, the predicted energy reduction amount Pc2 in the suppression continuous operation mode, and the predicted energy reduction amount Pi in the intermittent operation mode, the predicted energy reduction amount Pi in the intermittent operation mode If the predicted energy reduction amount Pi in the intermittent operation mode is not the maximum, the operation mode of the fuel cell FC is changed to the predicted energy reduction amount Pc1 and the suppression continuous operation mode in the load following continuous operation mode. Is set to the operation mode corresponding to the larger energy reduction amount of the predicted energy reduction amount Pc2 at the time, that is, continuous operation Will be set to over-de (Step # 6).

  Although details will be described later, among the predicted energy reduction amount Pc1 in the load following continuous operation mode, the predicted energy reduction amount Pc2 in the suppression continuous operation mode, and the predicted energy reduction amount Pi in the intermittent operation mode, in the intermittent operation mode. When the predicted energy reduction amount Pi is determined to be the maximum, the operation mode of the fuel cell FC is set to the intermittent operation mode, and the selection condition is set to the one having the higher operation advantage among the continuous operation advantage and the intermittent operation advantage. It is defined in the conditions defined in the corresponding operation mode.

  In step # 5, among the predicted energy reduction amount Pc1 in the load following continuous operation mode, the predicted energy reduction amount Pc2 in the suppression continuous operation mode, and the predicted energy reduction amount Pi in the intermittent operation mode, the predicted energy in the intermittent operation mode When it is determined that the reduction amount Pi is the maximum, in step # 7, a heat load coverage rate U / L indicating the extent to which the predicted heat load of the operation cycle can be covered by the amount of stored hot water at the start of the operation cycle is obtained, and step # 8 compares the obtained thermal load coverage rate U / L with the lower set value K, and determines that the standby condition is satisfied when the thermal load coverage rate U / L is greater than the lower set value K; When the thermal load coverage ratio U / L is lower than the lower set value K, it is determined that the standby condition is not satisfied.

In this embodiment, L of the thermal load coverage ratio U / L is the predicted thermal load of the first operation cycle obtained by summing the predicted thermal loads (m) of each unit time of the first operation cycle.
Further, U of the thermal load coverage rate U / L can be covered by the amount of stored hot water at the start of the first operation cycle out of the predicted heat load of the first operation cycle with the generated heat amount (d) of the fuel cell FC being 0. Is the predicted amount of heat used.
For example, assuming that the start time of the first operation cycle is in the state of the start time of the operation cycle shown in FIG. 5B, L is the total unit time of the operation cycle as shown in FIG. 5B. The predicted heat load (m) of (time 0 to 23) is a total value, and U is the predicted amount of heat used (n) for the entire unit time (time 0 to 23) of the operation cycle as shown in FIG. 5 (b). Is the total value.
The lower set value K is set to 0.4, for example.

  That is, since there is heat radiation from the hot water tank 2, when obtaining the heat load coverage rate indicating the extent to which the predicted heat load in the first operation cycle can be covered by the amount of hot water stored in the hot water tank 2 at the start of the first operation cycle. Rather than using the amount of hot water stored in the hot water tank 2 at the start of the first operation cycle, it is predicted that the predicted heat load of the first operation cycle can be covered by the amount of stored hot water at the start of the first operation cycle. Since the direction which uses the utilization heat amount U can consider the heat radiation from the hot water storage tank 2, it can obtain | require a heat load coverage rate appropriately.

  When it is determined in step # 8 that the standby condition is not satisfied, the operation mode of the fuel cell FC is set to the intermittent operation mode, the operation time zone setting process is executed as described above, and the operation in the intermittent operation mode is performed. A time zone is set (step # 9, step # 10).

  If it is determined in step # 8 that the standby condition is satisfied, it is determined in step # 11 whether or not the fuel cell FC is in operation. If it is in operation, in step # 12, the heat load is covered. When it is determined whether the rate U / L is larger than the upper set value M (for example, 0.9) that is larger than the lower set value K and not larger, in step # 13, the fuel cell FC is determined. It is determined whether or not the operation continuation condition for continuing the operation is satisfied.

  That is to say, all the temporary operations that are assumed to be the operation time zone in the temporary operation pattern stored in the memory 5a, which continues from the start time point and includes a unit time of 1 to the set number N2 (for example, 10). For each of the patterns, assuming that the main operation for following the predicted power load is performed during the operation time period, it is determined whether or not the amount of stored hot water in the final unit time in the first operation cycle is 0, and the amount of stored hot water is When there is a temporary operation pattern that becomes zero, it is possible to continue the operation of the fuel cell FC without entering a heat surplus state in which the amount of stored hot water in the final unit time of the first operation cycle is greater than zero. Yes, it is determined that the operation continuation condition is satisfied, and when there is no provisional operation pattern in which the amount of stored hot water becomes 0, it is determined that the operation continuation condition is not satisfied.

  If it is determined in step # 13 that the operation continuation condition is satisfied, in step # 14, the operation mode of the fuel cell FC is set to the operation continuation mode in which the operation of the fuel cell FC is continued for the operation duration time. In 15, the operation duration setting process for setting the operation duration is executed.

In the operation continuation time setting process, the operation of the temporary operation pattern in which the predicted energy reduction amount P is the maximum among the temporary operation patterns determined in step # 13 that the amount of stored hot water in the final unit time in the first operation cycle becomes zero. Set the time zone to the operation duration.
In other words, the energy consumption amount E2 when the fuel cell FC is operated for each of the temporary operation patterns determined in step # 13 that the amount of stored hot water in the final unit time in the first operation cycle becomes 0 is calculated when Equation 6 is started. The predicted energy is obtained by substituting the calculated energy consumption E2 and the energy consumption E1 when the fuel cell FC is not operated obtained by Equation 3 into the equation 2 for the non-consumption / stop-time operation. The reduction amount P is obtained, and the operation time zone of the temporary operation pattern in which the obtained predicted energy reduction amount P is maximum is set as the operation continuation time.

  When it is determined in step # 4 that the execution of the standby mode saves energy, in step # 11, when it is determined that the fuel cell FC is stopped, in step # 12, the thermal load coverage rate When it is determined that U / L is larger than the upper set value M, in step # 13, when it is determined that the operation continuation condition is not satisfied, the standby mode is set (step # 16).

  When the operation mode of the fuel cell FC is set to the load following continuous operation mode in the operation mode setting process, the operation control device 5 executes the main operation for following the current power load over the entire time period of the operation cycle. When the suppression continuous operation mode is set, the main operation for adjusting the power generation output of the fuel cell FC to the set suppression output in the suppression time zone and following the current power load in the other time zone is set. When the operation mode is set to the intermittent operation mode, the main operation is performed to follow the current power load in the operation time zone set in the operation time zone setting process. When the operation of the fuel cell FC is continued and set to the standby mode in the form of executing the main operation to follow the current power load for the operation continuation time set in the setting process, the next operation cycle Stopping the operation of the fuel cell FC over the time period.

  That is, the operation mode setting process is executed every time the operation cycle starts, and in the operation mode execution process, as described above, the thermal load coverage ratio U / L is larger than the lower set value K and the standby condition is set. When it is determined that the fuel cell FC is stopped, when it is determined that the fuel cell FC is in operation, when it is determined that the fuel cell FC is in operation and the thermal load coverage ratio U / L is greater than the upper set value M, and In any case where it is determined that the fuel cell FC is in operation and the thermal load coverage ratio U / L is lower than the upper set value M and does not satisfy the operation continuation condition, the standby mode is set. Therefore, when the operation mode setting process is set to the 2-day intermittent operation mode and the time point when the current operation mode setting process is performed corresponds to the start time of the second operation cycle in the 2-day intermittent operation mode. ,That When the standby mode is set as described above in the rotation mode determination process, the fuel cell FC is stopped over the entire time period of the second operation cycle in the 2-day intermittent operation mode, and the 2-day intermittent operation is performed. The mode is executed.

In addition, in the intermittent operation mode every two days, the actual thermal load in the first operation cycle is greater than the predicted thermal load, and it is determined that the thermal load coverage rate U / L is lower than the lower set value K and does not satisfy the standby condition. Then, the intermittent operation mode is newly set.
When it is determined that the thermal load coverage rate U / L is greater than the lower set value K and the standby condition is satisfied, the fuel cell FC is in operation and the thermal load coverage rate U / L is less than or equal to the upper set value M. When it is determined that the operation continuation condition is satisfied, the fuel cell FC continues to operate so that the heat does not remain excessive even when the final unit time in the first operation cycle is reached, and thus consumes energy at startup. Therefore, it is possible to sufficiently cover the heat load of the first operation cycle, and energy saving can be further improved.

Second Embodiment
The operation control apparatus of the second embodiment is different from the first embodiment in the method for determining the intermittent operation merit. Although the content of the control performed by the operation control apparatus of 2nd Embodiment is demonstrated below, description is abbreviate | omitted about the structure similar to 1st Embodiment.

  In the first embodiment, the operation mode determination target period is set to be equal to or less than the allowable stop period in which the fuel cell can be continuously maintained in the operation stop state. However, in the present embodiment, the operation mode determination target period is limited. Is not provided. However, in this embodiment, when determining the combination of the operation time zone and the non-operation time zone of the intermittent operation pattern, the continuous stop period that continuously occurs before and after the operation time period is set to be equal to or less than the allowable stop period. Restrict. By doing so, at least in the intermittent operation mode, the fuel cell is not continuously stopped for a length longer than the allowable stop period.

  That is, the control unit 5b of the operation control device 5 determines the operation mode determination target based on the time-series predicted power load and the time-series predicted heat load at the start of the operation mode determination target period of the fuel cell FC. The operation merit derived when the fuel cell FC is assumed to be continuously operated in all time periods of the period is determined as the continuous operation merit, and a part of the operation mode determination target period is set as the operation time period. Assuming that the fuel cell FC is intermittently operated by setting the remaining time zone as a non-operation time zone and limiting the continuous stop period that occurs continuously before and after the operation time period to be equal to or less than the allowable stop period. When the driving merit is derived while changing the combination of the belt and the non-driving time zone, the driving merit that becomes the largest is determined as the intermittent driving merit, and the operation mode judgment target period The operation merit when it is assumed that the fuel cell FC is stopped and the operation is waited in all the time zones is determined as the standby merit, and based on the determined continuous operation merit, intermittent operation merit and standby merit, The operation mode is determined as one of a continuous operation mode, an intermittent operation mode, and a standby mode. In the present embodiment, the largest driving merit is determined as the intermittent driving merit, but it is not limited to determining the largest driving merit as the intermittent driving merit. For example, the second largest or the third largest driving merit may be modified so as to be determined as the intermittent driving merit.

An example in which the continuous stop period continuously generated before and after the operation time period is limited to the allowable stop period or less will be described below.
FIG. 9 is a diagram illustrating the relationship between the temporary operation pattern, the continuous stop period before startup, and the continuous stop period after stop in the second embodiment. In FIG. 9, as in FIG. 6, the temporary operation pattern (temporary operation pattern in the first operation cycle within the operation mode determination target period) from the start point of the operation mode determination target period (that is, the operation mode setting processing timing) is shown. Illustrated. In addition, FIG. 9 shows a continuous stop period T1 before the start of the fuel cell FC (corresponding to the “first continuous stop period” of the present invention) and a continuous stop period T2 after the stop of the fuel cell FC (the “first An example of “two continuous stop periods” is also illustrated.

  The continuous stop period T1 before start-up is a continuous stop period that occurs continuously before the operation time period set in the temporary operation pattern. The control unit 5b of the operation control device 5 includes a continuous stop period T1 before start-up, a period during which the fuel cell FC has been continuously stopped before the start of the current operation mode determination target period, and a current operation mode determination target period. This is determined by the sum of the period in which the fuel cell FC is continuously stopped before the start of the operation and before the operation time period. In other words, the pre-start continuous stop period T1 is the actual time t1 that was continuously stopped until the current operation mode setting processing timing, and the time that is stopped before the start of operation within the current temporary operation pattern. And the sum of In FIG. 9, t1 indicates the actual time that has been continuously stopped until the operation mode setting processing timing. Since the control unit 5b of the operation control device 5 controls the operation of the fuel cell FC by itself, it knows the value of t1. In FIG. 9, t2 indicates a time obtained by subtracting a time corresponding to the first driving cycle from a time corresponding to the driving mode determination target period. For example, when the operation cycle is set to one day and the operation mode determination target period is set to two consecutive operation cycles (that is, two days), t2 is 24 hours (= 48 hours-24 hours). In the example shown in FIG. 9, when paying attention to the temporary operation pattern 1, the time during which the operation is stopped before the start of operation in the temporary operation pattern of this time is 0 hour. (T1 + 0). Further, when paying attention to the temporary operation pattern 35, since the time during which the operation is stopped within the temporary operation pattern of this time is one hour, the pre-start continuous stop period T1 is (t1 + 1).

  The continuous stop period T2 after the stop is a continuous stop period that continuously occurs after the operation time period set in the temporary operation pattern. The control unit 5b of the operation control device 5 determines the continuous stop period T2 after the stop in a period during which the fuel cell FC continuously stops after the current operation mode determination target period and after the operation time period. In other words, the continuous stop period T2 after the stop is determined by the sum of the time after the stop in the current temporary operation pattern and the time t2. In the example shown in FIG. 9, when paying attention to the temporary operation pattern 1, the time after the operation stop in the current temporary operation pattern is 23 hours, so the continuous stop period T2 after the stop is (23 + t2). Further, when paying attention to the temporary operation pattern 35, since the time after the operation stop in the temporary operation pattern of this time is 12 hours, the post-stop continuous stop period T2 is (12 + t2).

  As described above, when the fuel cell FC is operated according to a specific temporary operation pattern, the pre-start continuous stop period T1 represents a continuous stop period that is predicted to occur before the operation time period in the temporary operation pattern. The continuous stop period T2 after stop represents a continuous stop period that is predicted to occur after the operation time period in the temporary operation pattern when the fuel cell FC is operated according to the specific temporary operation pattern. The operation control device 5 extracts a temporary operation pattern in which both the continuous stop period T1 before start and the continuous stop period T2 after stop do not exceed the allowable stop period from the temporary operation patterns. Select one with high merit as the operation pattern for intermittent operation.

  Therefore, even if the fuel cell FC is intermittently operated, the continuous stop period continuously generated before and after the operation time period is limited to the allowable stop period or less. Even if the operation stop state of the battery FC continues for the longest, the length of the operation stop state continues is equal to or shorter than the allowable stop period. Therefore, if either the continuous operation mode or the intermittent operation mode is selected (that is, if the standby mode is not selected), the fuel cell FC is continuously operated for a period longer than the allowable stop period within the operation mode determination target period. Therefore, there will be no long-term stoppage that causes the operation to stop. If there is a possibility that the standby mode may be selected, for example, the intermittent operation mode is selected in a certain operation mode determination target period, the fuel cell FC is continuously stopped, and the operation mode determination target immediately thereafter is selected. When the standby mode is selected in the period, there is a possibility that the fuel cell FC is continuously stopped for a length equal to or longer than the allowable stop period over two consecutive operation mode determination target periods. However, if at least the continuous operation mode and the intermittent operation mode are selected, the long-term stop state in which the fuel cell FC is continuously stopped for a period longer than the allowable stop period does not appear. As a result, the possibility of oxygen entering the anode 52a from the cathode 52b is low, that is, the oxidation (deterioration) of the anode can be suppressed.

<Third Embodiment>
The operation control device of the third embodiment is different from the first embodiment in that the continuous operation mode is not selected. Although the content of the control performed by the operation control apparatus of 3rd Embodiment is demonstrated below, description is abbreviate | omitted about the structure similar to 1st Embodiment.

FIG. 10 is a block diagram illustrating an overall configuration of a cogeneration system provided with the operation control device of the third embodiment. FIG. 11 is a diagram illustrating a flowchart of the control operation of the third embodiment.
As shown in FIG. 10, the cogeneration system provided with the operation control device 5 of the third embodiment does not include a radiator. In other words, in the first embodiment, when the operation control device 5 determines that the amount of hot water stored in the hot water tank 2 is full, the hot water taken out from the lower portion of the hot water tank 2 is circulated so as to pass through the radiator 19 and the radiator. 19 was operated, and the hot water taken out from the lower part of the hot water storage tank 2 was radiated by the radiator 19. On the other hand, in this embodiment, since the radiator for radiating the hot water when the hot water storage amount of the hot water storage tank 2 becomes full is not provided, the hot water storage amount of the hot water storage tank 2 is not easily filled. That is, control is performed in advance so as not to select the continuous operation mode.

  That is, as in the first embodiment, when the fuel cell FC is continuously operated, heat is generated continuously, so that the amount of heat stored in the hot water tank 2 may be excessive. When the amount of heat stored in the hot water tank 2 becomes excessive, it is necessary to dissipate heat with a radiator. On the other hand, when the fuel cell FC is intermittently operated, heat is also generated intermittently, so the possibility that the amount of heat stored in the hot water tank 2 will be excessive is lower than when the fuel cell FC is continuously operated. . Therefore, if the fuel cell FC is not continuously operated, it is possible not to provide a radiator that is necessary when the amount of heat stored in the hot water tank 2 becomes excessive. Accordingly, since the control unit 5b of the operation control device 5 does not need to control the radiator to dissipate heat, the function of the control unit 5b can be simplified.

  Specifically, in the first embodiment, the operation control device 5 sets the operation mode (corresponding to the operation mode) of the fuel cell FC to the continuous operation mode (corresponding to the continuous operation mode) and the intermittent operation mode (intermittent operation mode). Or the operation mode (corresponding to the operation mode) of the fuel cell FC to the continuous operation mode (corresponding to the continuous operation mode) and the intermittent operation mode (intermittent operation mode). In this embodiment, the operation control device 5 is in either the intermittent operation mode or the standby mode. The specified operation mode setting process is executed.

  That is, the control unit 5b of the operation control device 5 sets the operation mode determination target period of the fuel cell FC set to a length equal to or shorter than the allowable stop period in steps # 1 to # 4, # 9, and # 16 of FIG. At the start time, based on the time-series predicted power load and the time-series predicted heat load, a part of the operation mode determination target period is set as the operation time period and the remaining time period is not set. Assuming that the fuel cell FC is operated intermittently as the operating time zone, the driving merit that becomes the largest when the operating merit is derived while changing the combination of the operating time zone and the non-operating time zone is determined as the intermittent operating merit, The operating merit when it is assumed that the fuel cell FC is stopped and the operation is made to stand by in the entire period of the form determination target period is determined as the standby merit, and the determined intermittent operation merit is determined. And based on the waiting benefits, to determine the operating mode of the fuel cell FC to any of the intermittent operation mode and the standby mode. In the present embodiment, the largest driving merit is determined as the intermittent driving merit, but it is not limited to determining the largest driving merit as the intermittent driving merit. For example, the second largest or the third largest driving merit may be modified so as to be determined as the intermittent driving merit.

  Hereinafter, based on the flowchart shown in FIG. 11, the operation mode selection process of 3rd Embodiment is demonstrated. The flowchart shown in FIG. 11 is obtained by omitting processing related to the continuous operation mode from the flowchart of FIG. 7 described in the first embodiment.

  The control unit 5b of the operation control device 5 configures the operation mode determination target period with two operation cycles subsequent to the start time every time the operation cycle starts (for example, 3 am). Update and execute the operation mode selection process.

  First, in steps # 1 to # 4, the control unit 5b of the operation control device 5 obtains predicted power load data and predicted heat load data each time the operation cycle starts, and executes operation merit calculation processing. Then, the predicted energy reduction amount Pi in the intermittent operation mode is calculated, and it is determined whether or not the maximum one of them is larger than the negative value “−Z” of the standby energy consumption Z. It is determined whether performing the mode saves energy compared to executing the standby mode in which the fuel cell FC is stopped in the entire time period of the operation cycle. That is, the energy consumption amount when the intermittent operation mode is executed is larger than the energy consumption amount when the fuel cell FC is not operated, and the predicted energy reduction amount Pi in the intermittent operation mode may be obtained as a negative value. However, when the predicted energy reduction amount Pi in the intermittent operation mode is larger than the negative value “−Z” of the standby energy consumption Z regardless of the positive / negative, it is better to execute the intermittent operation mode. It becomes energy saving rather than performing.

  If it is determined in step # 4 that the intermittent operation mode is more energy-saving than the standby mode is executed, in step # 7, the operation cycle is determined by the amount of stored hot water at the start of the operation cycle. The thermal load coverage rate U / L indicating the extent to which the predicted thermal load can be covered is obtained, and in step # 8, the obtained thermal load coverage rate U / L is compared with the lower set value K to obtain the thermal load coverage rate U When / L is larger than the lower set value K, it is determined that the standby condition is satisfied, and when the thermal load coverage rate U / L is equal to or lower than the lower set value K, it is determined that the standby condition is not satisfied.

  When it is determined in step # 8 that the standby condition is not satisfied, the operation mode of the fuel cell FC is set to the intermittent operation mode, the operation time zone setting process is executed as described above, and the operation in the intermittent operation mode is performed. A time zone is set (step # 9, step # 10).

  If it is determined in step # 8 that the standby condition is satisfied, it is determined in step # 11 whether or not the fuel cell FC is in operation. If it is in operation, in step # 12, the heat load is covered. When it is determined whether the rate U / L is larger than the upper set value M (for example, 0.9) that is larger than the lower set value K and not larger, in step # 13, the fuel cell FC is determined. It is determined whether or not the operation continuation condition for continuing the operation is satisfied.

  If it is determined in step # 13 that the operation continuation condition is satisfied, in step # 14, the operation mode of the fuel cell FC is set to the operation continuation mode in which the operation of the fuel cell FC is continued for the operation duration time. In 15, the operation duration setting process for setting the operation duration is executed.

  In the operation continuation time setting process, the operation of the temporary operation pattern in which the predicted energy reduction amount P is the maximum among the temporary operation patterns determined in step # 13 that the amount of stored hot water in the final unit time in the first operation cycle becomes zero. Set the time zone to the operation duration.

  When it is determined in step # 4 that the execution of the standby mode saves energy, in step # 11, when it is determined that the fuel cell FC is stopped, in step # 12, the thermal load coverage rate When it is determined that U / L is larger than the upper set value M, in step # 13, when it is determined that the operation continuation condition is not satisfied, the standby mode is set (step # 16).

  As described above, since the control unit 5b of the operation control device 5 sets the operation mode determination target period of the fuel cell FC to a length equal to or shorter than the allowable stop period, the operation is stopped during the one operation mode determination target period. Even if the state continues for the longest time, the length of the continuous operation stop state is equal to or shorter than the allowable stop period. Note that there is a possibility that the fuel cell FC is continuously stopped for a length equal to or longer than the allowable stop period over two continuous operation mode determination target periods. However, regardless of whether the intermittent operation mode or the standby mode is selected, a long-term stop state in which the operation is continuously stopped for a period longer than the allowable stop period does not appear within at least one operation mode determination target period. As a result, the frequency of appearance of a stopped state for a long period of time can be reduced, so that the possibility of oxygen entering from the cathode to the anode is low, that is, oxidation (deterioration) of the anode can be suppressed.

<Fourth embodiment>
The operation control apparatus of the fourth embodiment is different from the third embodiment in the method for determining the intermittent operation merit. Although the content of the control performed by the operation control apparatus of 4th Embodiment is demonstrated below, description is abbreviate | omitted about the structure similar to 3rd Embodiment.

In the third embodiment, the operation mode determination target period is set to be equal to or less than the allowable stop period in which the fuel cell can be continuously maintained in the operation stop state. However, in this embodiment, the operation mode determination target period is limited. Is not provided. However, in this embodiment, when determining the combination of the operation time zone and the non-operation time zone of the intermittent operation pattern, the continuous stop period that continuously occurs before and after the operation time period is set to be equal to or less than the allowable stop period. Restrict. By doing so, at least in the intermittent operation mode, the fuel cell is not continuously stopped for a length longer than the allowable stop period.
That is, the control unit 5b of the operation control device 5 at the start of the operation mode determination target period, based on the time-series predicted power load and the time-series predicted heat load, A fuel cell in which a part of the time zone is set as an operating time zone and the remaining time zone is set as a non-operating time zone, and the continuous stop period continuously generated before and after the operation time period is limited to an allowable stop period or less. Assuming that the FC is operated intermittently, the driving merit that becomes the largest when the driving merit is derived while changing the combination of the operating time zone and the non-operating time zone is determined as the intermittent operating merit, The operating merit when it is assumed that the fuel cell FC is stopped in the time zone and the operation is put on standby is determined as the standby merit, and the determined intermittent operation merit and standby merit are determined. Based on, to determine the operating mode of the fuel cell FC to any of the intermittent operation mode and the standby mode. In the present embodiment, the largest driving merit is determined as the intermittent driving merit, but it is not limited to determining the largest driving merit as the intermittent driving merit. For example, the second largest or the third largest driving merit may be modified so as to be determined as the intermittent driving merit.

  Therefore, even if the fuel cell FC is intermittently operated, the continuous stop period continuously generated before and after the operation time period is limited to the allowable stop period or less. Even if the operation stop state of the battery FC continues for the longest, the length of the operation stop state continues is equal to or shorter than the allowable stop period. For example, when the intermittent operation mode is selected in a certain operation mode determination target period and the fuel cell FC is continuously stopped, and when the standby mode is selected in the operation mode determination target period immediately after that, the continuous operation mode is selected. There is a possibility that the fuel cell FC is continuously stopped for a length equal to or longer than the allowable stop period over two operation form determination target periods. However, if the intermittent operation mode is selected, a long-term stop state in which the fuel cell FC is continuously stopped for a period longer than the allowable stop period does not appear. As a result, the possibility of oxygen entering the anode 52a from the cathode 52b is low, that is, the oxidation (deterioration) of the anode can be suppressed.

<Another embodiment>
<1>
In the said embodiment, when the control part 5b of the driving | operation control apparatus 5 determines a continuous driving merit, you may modify | change so that it may determine to a value larger than the value of the driving merit actually derived | led-out. That is, the problem of oxygen intrusion from the cathode 52b to the anode 52a is a problem that occurs during an operation stop period during intermittent operation, and such a problem occurs during continuous operation. Does not occur. Therefore, the control unit 5b of the operation control device 5 can easily select the continuous operation mode in step # 5 described above by determining the continuous operation merit to a value larger than the actually derived operation merit value. To do.
Or you may modify | change so that the control part 5b of the driving | operation control apparatus 5 may select a continuous driving mode, if a continuous driving merit is not a negative value in step # 5 mentioned above.
As long as the fuel cell FC is operated in the continuous operation mode, the problem of oxygen intrusion from the cathode 52b to the anode 52a does not occur. Therefore, in any of the above-described modifications, the oxidation (deterioration) of the anode 52a can be suppressed.

<2>
In the above embodiment, the example in which the fuel cell FC is not continuously operated in the cogeneration system not including the radiator as illustrated in FIG. 10 has been described. However, in the cogeneration system not including the radiator as illustrated in FIG. The fuel cell FC may be continuously operated. In that case, for example, when the operation control device 5 determines that the amount of hot water stored in the hot water tank 2 is full based on the detection result of the temperature sensor provided in the hot water tank 2, the operation control device 5 stops the generation of heat by stopping the fuel cell FC. You can do it.

<3>
In the above embodiment, the cogeneration system 1 includes a determination unit that determines whether or not the oxygen concentration in the vicinity of the cathode 52b when the fuel cell FC is in the operation stop state is equal to or higher than the set level, and the operation control device. 5 may be configured to cancel the maintenance of the operation stop state of the fuel cell FC when the determination unit determines that the oxygen concentration in the vicinity of the cathode 52b is equal to or higher than the set level.

  For example, the determination unit includes an oxygen information detection sensor that detects information related to the oxygen concentration in the vicinity of the cathode 52b, and the fuel cell FC is in a shutdown state based on the detection result of the oxygen information detection sensor. The apparatus includes a device that determines whether or not the oxygen concentration in the vicinity of the cathode 52b is equal to or higher than the set level. Specifically, the determination unit includes a voltage sensor 34 that detects an output voltage (cell voltage) of the fuel cell FC.

The reason why the voltage sensor 34 can function as a determination unit is as follows.
When the fuel cell FC is in the shutdown state, when the oxygen concentration in the vicinity of the cathode 52b rises and exceeds the set level, oxygen enters the anode 52a through the electrolyte 52c and hydrogen present on the anode 52a side. As a result, the cell voltage rises. On the other hand, when the hydrogen concentration on the anode 52a side is high, the hydrogen on the anode 52a side reacts with oxygen near the cathode 52b through the electrolyte, so the oxygen concentration near the cathode 52b is less than the set level and the cell voltage is also low. Does not rise.
Therefore, the voltage sensor 34 functioning as the determination unit and the oxygen information detection sensor is based on the detection result (that is, the detection result of the cell voltage), and the cathode 52b when the fuel cell FC is in the operation stop state. It is possible to determine whether or not the oxygen concentration in the vicinity of is above a set level.

  Alternatively, the determination unit is configured by a device that determines that the oxygen concentration in the vicinity of the cathode 52b is equal to or higher than the set level when the maintenance time of the operation stop state of the fuel cell FC reaches the allowable stop period. The Specifically, this determination unit is realized by a timer function provided in the operation control device 5. For example, the operation control device 5 functioning as the determination unit measures an elapsed time after the fuel cell FC is stopped, and when the elapsed time reaches the allowable stop period, the fuel cell FC is in an operation stop state. It is determined that the oxygen concentration in the vicinity of the cathode 52b at that time is equal to or higher than the set level.

As described above, when it is determined that the oxygen concentration in the vicinity of the cathode 52b when the fuel cell FC is in the operation stop state is equal to or higher than the set level, the control unit 5b of the operation control device 5 performs the fuel cell FC. The maintenance of the operation stop state is canceled. For example, the control unit 5b cancels the maintenance of the stopped state of the fuel cell FC by starting up the entire fuel cell system 50. Or control part 5b cancels maintenance of the stop state of fuel cell FC by starting only fuel gas generating device 51 and supplying hydrogen to anode 52a.
Thus, even if the oxygen concentration in the vicinity of the cathode 52b becomes equal to or higher than the set level when the fuel cell FC is in the operation stop state, the anode 52a can be maintained by eliminating the maintenance of the operation stop state of the fuel cell FC. It can be prevented from being oxidized by oxygen entering from the cathode 52b side.

<4>
In the first embodiment, the control unit 5b of the operation control device 5 has described the example in which the operation mode of the fuel cell FC is determined as any one of the continuous operation mode, the intermittent operation mode, and the standby mode. The type of FC operation mode may be changed. For example, the control unit 5b of the operation control device 5 converts the time-series predicted power load and the time-series predicted heat load at the start time of the operation mode determination target period set to a length equal to or shorter than the allowable stop period. Based on this, the operation merit derived when it is assumed that the fuel cell FC is continuously operated in all time periods of the operation mode determination target period is determined as the continuous operation merit, and a part of the operation mode determination target period is determined. Assuming that the fuel cell FC is intermittently operated with the time zone as the operating time zone and the remaining time zone as the non-operating time zone, it is the largest when the operating merit is derived while changing the combination of the operating time zone and the non-operating time zone Is determined as the intermittent operation advantage, and the operation mode of the fuel cell FC is continuously operated based on the determined continuous operation advantage and intermittent operation advantage. It may be modified so as to determine either the state and intermittent operation mode.

Similarly, in the second embodiment, the example in which the control unit 5b of the operation control device 5 determines the operation mode of the fuel cell FC to any one of the continuous operation mode, the intermittent operation mode, and the standby mode has been described. The type of operation mode of the fuel cell FC to be performed may be changed. For example, the control unit 5b of the operation control apparatus 5 determines the operation mode determination target based on the time-series predicted power load and the time-series predicted heat load at the start of the operation mode determination target period of the fuel cell FC. The operation merit derived when the fuel cell FC is assumed to be continuously operated in all time periods of the period is determined as the continuous operation merit, and a part of the operation mode determination target period is set as the operation time period. The remaining time zone is set as a non-operating time zone, and the continuous stop period that occurs continuously before and after the operating time period is limited to an allowable stop period or less to operate the fuel cell FC intermittently. When the driving merit is derived while changing the combination of the time zone and the non-operating time zone, the driving merit that becomes the largest is determined as the intermittent driving merit, and the determined continuous driving merit And based on the intermittent operation benefits, it may be modified to determine the operating mode of the fuel cell FC to any one of the continuous operation mode and intermittent operation mode.
In these examples, the largest driving merit is determined as the intermittent driving merit, but it is not limited to determining the largest driving merit as the intermittent driving merit. For example, the second largest or the third largest driving merit may be modified so as to be determined as the intermittent driving merit.

<5>
In the above-described embodiment, the fuel cell FC may be modified to include only the intermittent operation mode as the operation mode. For example, when the fuel cell FC is operated only in the intermittent operation mode in the second embodiment, the fuel cell FC is continuously stopped for a length equal to or longer than the allowable stop period over two continuous operation mode determination target periods. Will never be done. Therefore, it is possible to reliably eliminate the appearance of the above-described long-term stop state.

  The present invention makes it possible to continuously or intermittently operate a fuel cell in a preferable manner from the viewpoint of energy saving, economy, environment and the like according to the characteristics of the fuel cell while avoiding deterioration of the cell of the fuel cell. It can be used for a fuel cell operation control device.

5 Operation control device 5a Memory (storage means)
5b Control unit (control means)
52b Cathode FC fuel cell

Claims (10)

An operation control device for a fuel cell that is used for a plurality of types of fuel cells that have different oxygen concentration easiness in the vicinity of the cathode of the fuel cell during shutdown,
The fuel representing a permissible stop period that is allowed to continue to maintain the fuel cell in a shutdown state, and is set to be short enough to increase the oxygen concentration in the vicinity of the cathode of the fuel cell during the shutdown. Storage means for acquiring and storing time index information specific to the battery;
Control means for controlling the operation of the fuel cell so that the frequency of occurrence of a long-term stop state in which the operation is stopped continuously for a period longer than the allowable stop period is reduced according to the time index information acquired and stored. An operation control device for a fuel cell comprising: Regarding the determination of the operation mode of the fuel cell that can supply both heat and power within the operation mode determination target period,
The control means, at the start of the operation mode determination target period set to a length of the allowable stop period or less,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. The operation time is determined on the assumption that the fuel cell is intermittently operated with a part of the operation mode determination target period as an operation time period and the remaining time period as a non-operation time period. The driving merit that increases when driving merit is derived while changing the combination of the belt and the non-driving time zone is determined as the intermittent driving merit,
The operation control apparatus for a fuel cell according to claim 1, wherein the operation mode of the fuel cell is determined as either a continuous operation mode or an intermittent operation mode based on the determined continuous operation merit and the intermittent operation merit. Regarding the determination of the operation mode of the fuel cell that can supply both heat and power within the operation mode determination target period,
The control means, at the start of the operation mode determination target period set to a length of the allowable stop period or less,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. The operation time is determined on the assumption that the fuel cell is intermittently operated with a part of the operation mode determination target period as an operation time period and the remaining time period as a non-operation time period. Driving merit that increases when driving merit is derived while changing the combination of the non-operating time zone and the non-operating time zone is determined as an intermittent driving merit, and the fuel cell is stopped in all time zones of the operation mode determination target period The operation merit when assuming that the operation is on standby is determined as the standby merit,
2. The fuel cell according to claim 1, wherein the operation mode of the fuel cell is determined as one of a continuous operation mode, an intermittent operation mode, and a standby mode based on the determined continuous operation merit, the intermittent operation merit, and the standby merit. Operation control device. Regarding the determination of the operation mode of the fuel cell that can supply both heat and power within the operation mode determination target period,
The control means, at the start time of the operation mode determination target period,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. Determined as a merit, and a part of the operation mode determination target period is set as an operation time period and the remaining time period is set as a non-operation time period and is continuously before and after the operation time period. Assuming that the fuel cell is intermittently operated by limiting the continuous stop period that is generated to be less than or equal to the allowable stop period, it becomes larger when the operation merit is derived while changing the combination of the operation time period and the non-operation time period. It is assumed that the operation merit is determined as an intermittent operation merit and that the fuel cell is stopped and the operation is waited in the entire time period of the operation mode determination target period. Determining the operating benefits when a waiting merit,
2. The fuel cell according to claim 1, wherein the operation mode of the fuel cell is determined as one of a continuous operation mode, an intermittent operation mode, and a standby mode based on the determined continuous operation merit, the intermittent operation merit, and the standby merit. Operation control device.   The operation control device for a fuel cell according to any one of claims 2 to 4, wherein the control means determines the continuous operation merit to a value larger than the value of the actually derived operation merit. Regarding the determination of the operation mode of the fuel cell that can supply both heat and power within the operation mode determination target period,
The control means, at the start of the operation mode determination target period set to a length of the allowable stop period or less,
Based on the time-series predicted power load and the time-series predicted heat load, a part of the operation mode determination target period is an operation time period and the remaining time period is a non-operation time period Assuming that the fuel cell is intermittently operated, an operation merit that increases when an operation merit is derived while changing a combination of the operation time zone and the non-operation time zone is determined as an intermittent operation merit, and the operation mode determination The operation merit when assuming that the fuel cell is stopped and the operation is waited in the entire time period of the target period is determined as the standby merit,
The operation control apparatus for a fuel cell according to claim 1, wherein the operation mode of the fuel cell is determined as either an intermittent operation mode or a standby mode based on the determined intermittent operation merit and the standby merit. Regarding the determination of the operation mode of the fuel cell that can supply both heat and power within the operation mode determination target period,
The control means, at the start time of the operation mode determination target period,
Based on the time-series predicted power load and the time-series predicted heat load, a part of the operation mode determination target period is set as an operation time period, and the remaining time period is set as a non-operation time period. Assuming that the fuel cell is intermittently operated with the continuous stop period continuously generated before and after the operation time period being limited to the allowable stop period or less, the operation time period and the non-operation time period When driving merit is derived when driving merit is changed while changing the combination, it is determined as intermittent driving merit, and when the fuel cell is stopped in all time zones of the operation mode determination target period and the operation is put on standby The driving merit when assumed is determined as the standby merit,
The operation control apparatus for a fuel cell according to claim 1, wherein the operation mode of the fuel cell is determined as either an intermittent operation mode or a standby mode based on the determined intermittent operation merit and the standby merit.   The operation control device for a fuel cell according to claim 1, wherein the control means controls the operation of the fuel cell so that the long-term stop state does not appear. Regarding the determination of the operation mode of the fuel cell that can supply both heat and power within the operation mode determination target period,
The control means, at the start time of the operation mode determination target period,
Based on the time-series predicted power load and the time-series predicted heat load, the operation merits derived when the fuel cell is assumed to be continuously operated in the entire time zone of the operation mode determination target period are continuously operated. Determined as a merit, and a part of the operation mode determination target period is set as an operation time period and the remaining time period is set as a non-operation time period and is continuously before and after the operation time period. Assuming that the fuel cell is intermittently operated by limiting the continuous stop period that is generated to be less than or equal to the allowable stop period, it becomes larger when the operation merit is derived while changing the combination of the operation time period and the non-operation time period. The driving merit is determined as the intermittent driving merit,
9. The operation control device for a fuel cell according to claim 8, wherein the operation mode of the fuel cell is determined as either a continuous operation mode or an intermittent operation mode based on the determined continuous operation merit and the intermittent operation merit. Of the continuous stop period, the first continuous stop period that occurs continuously before the operation time period is a period in which the fuel cell is continuously stopped before the start of the operation mode determination target period, It is the sum of the period in which the fuel cell is continuously stopped after the start of the operation mode determination target period and before the operation time period,
The second continuous stop period that continuously occurs after the operation time period in the continuous stop period is during the operation mode determination target period and the fuel cell is continuously stopped after the operation time period. The operation control device for a fuel cell according to claim 4, wherein the operation control device is a period to be operated.

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