JP4875387B2 - Cogeneration system - Google Patents

Description

The present invention is provided with a combined heat and power device that generates both electric power and heat, hot water storage means for storing hot water in a hot water storage tank with heat generated by the combined heat and power supply device, and operation control means for controlling operation,
The present invention relates to a cogeneration system configured such that the operation control means repeats an intermittent operation in which an operation time zone is determined within an operation cycle consisting of a plurality of hours and the heat and power supply device is operated intermittently for each operation cycle.

  Such a cogeneration system is installed in a general household, and can use the power generated by the combined heat and power supply device, store hot water in the hot water storage tank using the heat generated from the combined heat and power supply device as a heat source, and supply hot water from the hot water storage tank Since it can be used, it is effective in improving energy saving, economic efficiency, and environmental performance. Incidentally, the combined heat and power device is composed of a fuel cell, an engine-driven generator, and the like.

  And in such a cogeneration system, it is comprised so that the intermittent operation which sets an operation time slot | zone and operates the heat / electricity supply apparatus intermittently within the operation cycle which consists of multiple hours, such as 24 hours, may be repeated for every operation cycle. ing. By the way, in the operation time zone, in consideration of the predicted power load and predicted heat load of the operation cycle, the heat generation generated by the combined heat and power supply device is insufficient for the predicted heat load, and the generated heat amount of the combined heat and power supply device is predicted heat. It is determined so as to suppress the excessive heat with respect to the load and to improve the operation merit of energy saving, economical efficiency or environmental performance.

  By the way, about the power load when the combined heat and power unit is stopped and the insufficient power for the power load during operation of the combined heat and power unit, it is covered by purchasing power from the commercial power source, and the heat generated by the combined heat and power unit with respect to the thermal load. Then, the shortage of heat is covered by the heat generated by the auxiliary heating means such as a gas combustion type.

  In such a cogeneration system, conventionally, at the start of the operation time zone, the operation of the combined heat and power device is started, and the operation is continued unconditionally until the end of the operation time zone. When the end time is reached, the combined heat and power supply device is unconditionally stopped (see, for example, Patent Document 1).

JP 2004-6217 A

  By the way, the actual heat load of each household varies greatly depending on the season. For example, the actual heat load may vary greatly depending on the operation cycle such as 24 hours, such as decreasing when going out and increasing when there is a visitor. is there.

  However, since the conventional cogeneration system is configured to operate the cogeneration device unconditionally during the operation time period, the actual thermal load of the operation cycle in which the intermittent operation is performed is the operation cycle. If the actual heat load of the operation cycle in which the intermittent operation is performed is smaller than the predicted heat load of the operation cycle, there is a possibility that excess heat may be generated. Therefore, in either case, there is a problem that the driving merit may be reduced.

  The present invention has been made in view of such circumstances, and its purpose is to provide a code that can be operated so as to improve operation merit by suppressing heat shortage or excess heat regardless of fluctuations in actual heat load. To provide a generation system.

The cogeneration system of the present invention includes a combined heat and power device that generates both electric power and heat, hot water storage means for storing hot water in a hot water storage tank using heat generated by the combined heat and power supply device, and operation control means for controlling operation. Is provided,
The operation control means is configured to repeat an intermittent operation for intermittently operating the combined heat and power device by setting an operation time zone within an operation cycle consisting of a plurality of hours, and for each operation cycle,
The precondition is that the operation control means is configured to continue the operation of the combined heat and power unit when an operation continuation condition is satisfied when a stop condition for stopping the combined operation of the combined heat and power unit is satisfied. It is assumed that

  That is, when the stop condition for stopping the operation of the cogeneration device is satisfied, the operation of the cogeneration device is continued if the operation continuation condition is satisfied.

In other words, if the actual heat load is greater than the predicted heat load and it is predicted that heat shortage will occur if the combined heat and power unit is stopped when the stop condition is satisfied, the operation continuation condition is satisfied. Therefore, it becomes possible to continue the operation without stopping the combined heat and power supply device, so that the heat shortage can be suppressed and the operation merit can be improved.
Therefore, it has become possible to provide a cogeneration system that can be operated so as to improve the operation merit by suppressing heat shortage regardless of actual fluctuations in heat load.

In addition to the above premise configuration, the first feature configuration is
The operation control means is configured so that, at the start of the operation cycle, the operation time zone is within the first operation cycle among a plurality of continuous operation cycles, and the predicted power load and the first operation in the first operation cycle. The time zone in which the operating merit obtained based on the predicted thermal load of the cycle is excellent, and the time zone in which the operating merit obtained based on the predicted power load of the first operating cycle and the predicted thermal load of the plurality of operating cycles is excellent. Among these, it is characterized in that it is configured to be set in a time zone in which driving merits are more excellent.

  In other words, the operation merit obtained is based on the predicted power load of the first operation cycle and the predicted heat load of the first operation cycle within the first operation cycle of a plurality of continuous operation cycles. Set to a time zone with better operating merits out of excellent time zones and time zones with superior operating merits obtained based on the predicted power load of the first operating cycle and the predicted thermal loads of the multiple operating cycles. Then, the cogeneration apparatus is operated in the set operation time zone.

That is, when the heat load is considerably small, a plurality of operating cycles are obtained depending on the amount of stored hot water obtained by the operation of the combined heat and power unit in the first operating cycle among a plurality of consecutive operating cycles (for example, two or three times). In some cases, it is possible to cover the heat load of the operation cycle other than the first operation cycle.
In such a case, the operation time zone is set to the time zone in which the operation merit obtained based on the predicted power load of the first operation cycle and the predicted heat load of the plurality of operation cycles is excellent, and the set Since the combined heat and power supply device is operated in the operation time zone, it is possible to improve the operation merit even when the heat load is considerably small. The operation time zone is preferably set to a time zone with the best driving merit, such as a time zone with the best driving merit.

When the actual heat load in the first operation cycle becomes larger than the predicted heat load, the operation continuation condition is satisfied, and the operation of the combined heat and power supply device can be continued. Therefore, heat deficiency can be suppressed and operating merit can be improved even in operating cycles other than the first operating cycle among the plurality of operating cycles.
Therefore, even when the heat load is relatively small, it is possible to operate so as to improve the operation merit by suppressing the shortage of heat regardless of the actual fluctuation of the heat load.

In addition to the first feature configuration, the second feature configuration is
When the cogeneration device is operating at the start of the operation cycle when the stop condition is, the amount of hot water stored in the hot water storage tank at the start time and the predicted heat load in the next operation cycle are It is characterized in that it is a condition that satisfies a waiting condition for waiting for driving.

  That is, when the combined heat and power device is in operation at the start of the operation cycle, the standby condition in which the amount of stored hot water in the hot water storage tank at the start time and the predicted heat load in the next operation cycle waits for the operation of the combined heat and power device. When satisfied, the stop condition is satisfied.

In other words, the combined heat and power supply device is operated in the first operation cycle among a plurality of continuous operation cycles, and the first of the plurality of operation cycles is determined by the amount of hot water stored in the hot water storage tank by the operation in the first operation cycle. When operating to cover the thermal load of the operating cycle other than the operating cycle, determine the extent to which the predicted thermal load in the next operating cycle can be covered by the amount of hot water stored in the hot water tank at the start of the operating cycle Therefore, based on the amount of stored hot water in the hot water tank at the start time and the predicted heat load in the next operation cycle, the combined heat and power supply device is stopped during the next operation cycle, that is, the operation of the combined heat and power supply device is stopped. It is possible to determine whether or not a standby condition for waiting is satisfied.
Then, when the combined heat and power device is operating at the start of the operation cycle, the stop condition is a condition in which the amount of stored hot water in the hot water storage tank at the start time and the predicted heat load in the next operation cycle satisfy the standby condition. Accordingly, it is possible to accurately determine whether or not the stop condition is satisfied in a state where the operation merit is not impaired regardless of the actual fluctuation of the heat load.
Therefore, it is possible to accurately determine whether or not the stop condition is satisfied, so that it is possible to accurately continue the operation of the combined heat and power supply when the operation continuation condition is satisfied. The driving merit can be improved.

The third feature configuration is in addition to the second feature configuration,
Among the operation merits for each operation continuation time that the operation continuation condition is obtained by varying the operation continuation time based on the predicted power load and predicted heat load of the next operation cycle, the operation of the cogeneration device is stopped. It is characterized in that it is a condition that there is an operation continuation time that is better than that.

  That is, it is superior to stopping the operation of the combined heat and power supply device among the operation merits for each operation continuation time obtained by varying the operation continuation time based on the predicted power load and the predicted heat load of the next operation cycle. The operation continuation condition is satisfied when the operation continuation time exists.

That is, based on the predicted power load and predicted heat load of the next operation cycle, the operation merit when the operation of the combined heat and power supply device is continued is obtained for each operation duration in a state where the operation duration is different.
And, among the operation merits for each calculated operation continuation time, the operation continuation condition is satisfied when there is an operation continuation time that is superior to stopping the operation of the combined heat and power supply device. In view of the predicted power load and the predicted heat load of the operation cycle, it can be determined whether or not the operation merit can be improved by continuing the operation of the combined heat and power supply device. It is possible to accurately determine whether or not.
Therefore, since it is possible to accurately determine whether or not the operation continuation condition is satisfied, it is possible to appropriately continue the operation of the combined heat and power unit for improving the operation merit. The driving merit can be improved.

In addition to the third feature configuration, the fourth feature configuration is
The different driving continuation times for obtaining the driving merit are shorter than the driving cycle.

In other words, since the different operation continuation time for calculating the operation merit is shorter than the operation cycle, even if the operation continuation time for continuing the operation of the cogeneration device is set, the operation time zone of the cogeneration device is set. Therefore, it is possible to avoid setting the heat load of the operation cycle ahead of a plurality of continuous operation cycles, which is a target, to such a long time that the hot water is stored in the hot water tank.
Therefore, the operation of the combined heat and power device in the first operation cycle among a plurality of continuous operation cycles is performed while continuing the operation of the combined heat and power device so as to suppress the heat shortage regardless of the actual heat load fluctuation. As a result, the intermittent operation in the form of covering the heat load of the operation cycle other than the first operation cycle can be performed accurately.

In addition to the third or fourth feature configuration, the fifth feature configuration includes:
The operation control means operates the cogeneration device by operating the cogeneration device for an operation continuation time in which the amount of heat generated from the cogeneration device due to continuation of operation of the cogeneration device is the best operation merit. When the amount of heat predicted to be generated from the apparatus is reached, the combined heat and power supply apparatus is stopped.

  That is, the amount of heat generated from the combined heat and power unit due to the continued operation of the combined heat and power unit is changed to the amount of heat that is expected to be generated from the combined heat and power unit by operating the combined heat and power unit for the duration of operation where the operation merit is the best. When it reaches, the combined heat and power supply is stopped.

In other words, the timing of stopping the combined heat and power unit when the combined operation of the combined heat and power unit is not managed by time, but the amount of heat generated from the combined heat and power unit due to the continued operation of the combined heat and power unit is the most advantageous for operation. By operating the combined heat and power unit for an excellent operating duration, it is managed by whether or not the amount of heat that is expected to be generated from the combined heat and power unit is reached. Can be done to improve.
Therefore, it has become possible to drive so as to further improve the driving merit.

In addition to any of the second to fifth feature configurations described above, the sixth feature configuration is
When the operation control means does not satisfy the standby condition at the start of the operation cycle, the operation time zone is within the first operation cycle of a plurality of consecutive operation cycles, and the first operation cycle Obtained based on the predicted power load and the predicted heat load of the first operation cycle, the time zone in which the operation merit is excellent, and the predicted power load of the first operation cycle and the predicted heat load of the plurality of operation cycles. It is characterized in that it is configured to perform setting in a time zone in which the driving merit is more excellent among the time zones in which the driving merit is excellent.

  That is, when the standby condition for waiting for the operation of the combined heat and power supply device is not satisfied at the start of the operation cycle, the operation time period is within the first operation cycle of the plurality of consecutive operation cycles, Based on the time period in which the operation merit obtained based on the predicted power load of the operation cycle and the predicted heat load of the first operation cycle is excellent, and the predicted power load of the first operation cycle and the predicted heat load of the plurality of operation cycles Of the time periods in which the driving merit is excellent, the time period in which the driving merit is more excellent is set.

That is, the actual heat load in the operation cycle is greater than the predicted heat load, and the heat load of the operation cycle other than the first operation cycle among the plurality of operation cycles is determined by the amount of hot water stored in the hot water tank at the start of the operation cycle. May not be sufficient.
Therefore, even if intermittent operation is performed in a form in which the heat load of the operation cycle other than the first operation cycle is covered by the operation of the combined heat and power device in the first operation cycle among a plurality of continuous operation cycles, the operation cycle At each start time, based on the amount of stored hot water in the hot water tank at the start time and the predicted heat load in the next operation cycle, it is determined whether or not the standby condition is satisfied. Since the operation time zone is reset and the intermittent operation is performed as the first operation cycle among the plurality of operation cycles in which the cycle is continuous, excess heat and insufficient heat can be suppressed.
Therefore, the intermittent operation in the form of covering the heat load of the operation cycle other than the first operation cycle by the operation of the combined heat and power device in the first operation cycle among the plurality of continuous operation cycles is changed to the fluctuation of the actual heat load. Regardless, it has become possible to suppress excess heat and insufficient heat.

In addition to the sixth feature configuration, the seventh feature configuration is
In the case where the standby condition is not satisfied at the start of the operation cycle, the operation control means stops the combined heat and power unit during the next operation cycle, and operates in an operation time zone in which the operation merit is excellent. When the operation merit is superior to that, the heat and power supply device is configured to stop in the next operation cycle.

  In other words, if the standby condition is not satisfied at the start of the operation cycle, stopping the combined heat and power unit during the next operation cycle has better operation merit than operating in the operation time zone where operation merit is better. The combined heat and power supply device is stopped in the next operation cycle.

In other words, if the power load or heat load in the next operation cycle is quite small, rather than operating in the operation time zone where the operation merit is excellent, the cogeneration system is stopped and the power load is purchased from the commercial power source. In some cases, it is better to cover the heat load with the heat stored in the hot water storage tank at that time and the heat generated by the auxiliary heating means.
Therefore, when it is determined that the standby condition is not satisfied, the combined heat and power unit is stopped during the next operation cycle instead of operating in the operation time zone where the operation merit is excellent. If it is determined that the driving merit is superior to driving in the driving time period when the driving merit is excellent, and it is determined that the driving merit is superior, the thermoelectric power is The co-feeding device is stopped.
Therefore, the cogeneration apparatus can be operated so as to further improve the operation merit.

Eighth characterizing feature, in addition to the first feature structure,
The amount of heat that the stop condition is predicted to be generated from the combined heat and power device by operating the combined heat and power device during the operation time period is the amount of heat generated from the combined heat and power device when the combined heat and power device is operated. It is characterized in that the condition is reached.

  That is, when the amount of heat generated from the combined heat and power unit by operating the combined heat and power unit reaches the amount of heat that is expected to be generated from the combined heat and power unit by operating the combined heat and power unit during the operation time period, the stop condition is set. It is filled.

In other words, the amount of heat generated from the combined heat and power supply device may vary due to, for example, fluctuations in temperature or the like, even if the amount of fuel consumed is the same.
Therefore, when the amount of heat generated from the combined heat and power unit by operating the combined heat and power unit reaches the amount of heat expected to be generated from the combined heat and power unit by operating the combined heat and power unit during the operation time period, the combined heat and power unit The amount of heat that can improve the operation merit can be generated more accurately than when the combined heat and power unit is unconditionally stopped at the end of the operation time period. it can.
Therefore, intermittent operation can be performed accurately in order to improve driving merit.

In addition to the eighth feature configuration, the ninth feature configuration is
The operation continuation condition is characterized in that a thermal coverage index indicating a degree to which a predicted heat load after that can be covered by the amount of stored hot water in the hot water storage tank when the stop condition is satisfied is a condition that is equal to or less than a set value. To do.

That is, the operation continuation condition is satisfied when the thermal coverage index indicating the extent to which the predicted thermal load thereafter can be covered by the amount of hot water stored in the hot water storage tank when the stop condition is satisfied is equal to or less than the set value.
In other words, since the degree of heat shortage can be accurately determined using the thermal coverage index, it is possible to determine whether or not to continue operating the combined heat and power system using the thermal coverage index. The operation of the combined heat and power supply device can be continued so as to suppress it appropriately.
Therefore, it has become possible to appropriately improve the operation merit by appropriately suppressing the heat shortage regardless of the actual fluctuation of the heat load.

In addition to any of the first to ninth feature configurations described above, the tenth feature configuration is
The driving merit is energy saving, economical or environmental.

That is, the operation time zone is set so that energy saving, economic efficiency, or environmental performance is improved.
Incidentally, the environmental property is, for example, a reduction amount of carbon dioxide gas.
Therefore, the combined heat and power supply apparatus can be operated so that energy saving, economical efficiency, and environmental performance are improved.

In addition to any of the first to tenth feature configurations, the eleventh feature configuration is
In determining the operation merit used for determining whether or not the operation continuation condition is satisfied, it is characterized in that the energy loss at the startup of the combined heat and power supply apparatus is determined as zero.

That is, when continuing the operation of the combined heat and power device, there is no energy loss at the time of start-up, so by determining whether or not the operation continuation condition is satisfied, the energy loss at the start of the combined heat and power device is made zero. It is possible to accurately determine whether or not the operation continuation condition is satisfied.
Therefore, since it is possible to accurately determine whether or not the operation continuation condition is satisfied, it is possible to appropriately continue the operation of the combined heat and power unit for improving the operation merit. The driving merit can be improved.

In addition to the first feature configuration , the twelfth feature configuration is
When the operation control means determines that the predicted heat load is not generated or the actual heat load is smaller than the predicted heat load during the operation of the cogeneration device, the hot water storage in the hot water storage tank at the time of the determination The heat and power cogeneration apparatus is configured to be forcibly stopped when a heat coverage index indicating a degree to which the predicted heat load after that time can be covered by the amount of heat is a set value or more.

  That is, when it is determined that the predicted heat load has not occurred or the actual heat load is smaller than the predicted heat load during the operation of the combined heat and power supply device, the amount of hot water stored in the hot water storage tank at that time is determined thereafter. When the thermal coverage index indicating the degree of coverage of the predicted thermal load is equal to or greater than the set value, the combined heat and power supply device is forcibly stopped.

In other words, when the predicted heat load is not generated or the actual heat load is smaller than the predicted heat load, there is a possibility that excess heat may be generated when the combined heat and power supply device is operated over the entire operation time period.
Therefore, when the setting value is set to a value that may cause excess heat if the thermal coverage index is equal to or greater than the set value, it is determined whether the thermal coverage index is equal to or greater than the set value. Therefore, it is possible to accurately determine whether or not the heat residue is generated.
Then, when it is determined that the predicted heat load has not occurred or the actual heat load is smaller than the predicted heat load, the combined heat and power device is forcibly stopped if the thermal coverage index at the time of the determination is equal to or greater than the set value. As a result, the heat surplus can be suppressed and the operating merit can be improved.
Therefore, it has become possible to provide a cogeneration system that can be operated so as to improve the operating merit by suppressing excess heat regardless of actual fluctuations in heat load.

In addition to any of the first to twelfth feature configurations, the thirteenth feature configuration is the operation mode of the combined heat and power supply device. In addition to the intermittent operation, the combined heat and power supply device is used in all time zones within the operation cycle. With continuous operation,
When the operation control means is configured to select one of the intermittent operation and the continuous operation based on an operation determination condition at the start of the operation cycle, and when the intermittent operation is selected. When the stop condition is satisfied, it is configured to determine whether or not the operation continuation condition is satisfied.

  That is, at the start of the operation cycle, either intermittent operation or continuous operation is selected based on the operation determination condition, and when the intermittent operation is selected, when the stop condition is satisfied, When it is determined whether or not the operation continuation condition is satisfied and continuous operation is selected, the continuous operation is executed.

In other words, the heat load of each household increases greatly during the cold season and decreases during the warm season, and varies greatly depending on the season, and may vary greatly depending on the day of the week.
Therefore, since heat generated from the combined heat and power device by intermittent operation may not be able to sufficiently cover a large heat load, continuous operation is provided in addition to intermittent operation as an operation mode of the combined heat and power device. May be.

As the operation determination condition, for example, the intermittent operation is selected when the predicted thermal load is small, and the continuous operation is selected when the predicted thermal load is large.
For example, based on the predicted power load and the predicted heat load, when it is assumed that intermittent operation is performed and when it is assumed that continuous operation is performed, the respective energy savings (for example, predicted energy reduction amount) are evaluated, Adopt the condition to select the one that excels in energy saving.
That is, by operating the combined heat and power device so as to suppress excess heat and insufficient heat, it is possible to improve the energy saving by operating the combined heat and power device. As a result, intermittent operation is selected when the predicted thermal load is small, and continuous operation is selected when the predicted thermal load is large. Will be.

As described above, when either the intermittent operation or the continuous operation is selected based on the operation determination condition and the intermittent operation is selected, the operation continuation condition is satisfied when the stop condition is satisfied. If it is determined whether or not the operation continuation condition is satisfied, the operation of the combined heat and power supply device is continued. Therefore, even if the actual heat load fluctuates, You can drive.
Therefore, the operation mode of the combined heat and power supply apparatus is set so that both excess heat and insufficient heat can be suppressed even if the predicted heat load varies greatly, and the combined heat and power supply apparatus is operated in the set operation form. However, it became possible to suppress the heat shortage regardless of the actual fluctuation of the heat load.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIGS. 1 and 2, the cogeneration system recovers the heat generated by the fuel cell 1 as a combined heat and power generation apparatus that generates electric power and heat with cooling water, and cools the cooling. Hot water storage unit 4 as hot water storage means for storing hot water in hot water tank 2 and supplying heat medium to heat consuming terminal 3 using water, and operation control means for controlling the operation of fuel cell 1 and hot water storage unit 4 It is comprised from the operation control part 5 grade | etc.,.

The fuel cell 1 is configured such that its output can be adjusted. An inverter 6 for grid connection is provided on the power output side of the fuel cell 1, and the inverter 6 generates power generated by the fuel cell 1. It is configured to have the same voltage and the same frequency as the received power received from the commercial power source 7.
The commercial power source 7 is, for example, a single-phase three-wire system 100/200 V, and is electrically connected to a power load 9 such as a television, a refrigerator, or a washing machine via a received power supply line 8.
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 1 is supplied to the power load 9 via the inverter 6 and the generated power supply line 10. Is configured to do.

The received power supply line 8 is provided with power load measuring means 11 for measuring the load power of the power load 9, and the power load measuring means 11 generates a reverse power flow in the current flowing through the received power supply line 8. It is also configured to detect whether or not.
The electric power supplied from the fuel cell 1 to the received power supply line 8 is controlled by the inverter 6 so that a reverse power flow does not occur, and the surplus power of the generated power is recovered by replacing the surplus power with heat. 12 is configured to be supplied.

The electric heater 12 is composed of a plurality of electric heaters, and is provided so as to heat the cooling water of the fuel cell 1 flowing through the cooling water circulation path 13 by the operation of the cooling water circulation pump 15, and is connected to the output side of the inverter 6. ON / OFF is switched by the actuated switch 14.
The operation switch 14 is configured to adjust the power consumption of the electric heater 12 according to the amount of surplus power so that the power consumption of the electric heater 12 increases as the amount of surplus power increases. Yes.
The configuration for adjusting the power consumption of the electric heater 12 is a configuration for adjusting the output of the electric heater 12 by, for example, phase control or the like in addition to the configuration for switching ON / OFF of the plurality of electric heaters 12 as described above. You may adopt.

  The hot water storage unit 4 supplies hot water for hot water 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 to be circulated, a heat medium circulation pump 23 to circulate and supply the heat medium to the heat consuming terminal 3 through the heat medium circulation path 22, a hot water storage heat exchanger 24 to heat the hot water flowing through the hot water circulation path 16, The heat source heat exchanger 25 for heating the hot water for heat source flowing through the heat source circulation path 20, the heat exchanger for heat medium heating 26 for heating the heat medium flowing through the heat medium circulation path 22, and the fan 27 are operated. In this state, an auxiliary heating heat exchanger 29 for heating the hot water taken out from the hot water storage tank 2 by the combustion of the burner 28 and the heat source hot water flowing through the heat source circulation path 20 is provided.

  The hot water circulation path 16 is branched and connected so that a part thereof is in parallel, a three-way valve 18 is provided at the connection location, and a radiator 19 is provided in the branched flow path. Yes. 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. It is comprised so that it may switch to the state to be made to.

  The hot water storage heat exchanger 24 is configured to heat the hot water flowing through the hot water circulation path 16 by flowing the cooling water of the cooling water circulation path 13 that has recovered the heat output from the fuel cell 1. Has been. In the heat source heat exchanger 25, the hot water for the heat source flowing through the heat source circulation path 20 is heated by flowing the cooling water in the cooling water circulation path 13 that has recovered the heat generated by the fuel cell 1. It is configured. The auxiliary heating means M includes a fan 27, a burner 28, and an auxiliary heating heat exchanger 29. Further, the heat source circulation path 20 is provided with a heat source intermittent valve 40 for intermittently flowing the heat source hot water.

The cooling water circulation path 13 is branched into a hot water storage heat exchanger 24 side and a heat source heat exchanger 25 side, and the flow rate of the cooling water to be passed to the hot water storage heat exchanger 24 side and the heat source use are branched at the branch points. A diversion valve 30 is provided that adjusts the ratio of the flow rate of the cooling water that flows to the heat exchanger 25 side.
The diversion valve 30 allows the entire amount of cooling water in the cooling water circulation path 13 to flow to the hot water storage heat exchanger 24 side, or 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 is comprised so that it can also be made.

In the heat exchanger for heat medium heating 26, the hot water for the heat source heated by the heat exchanger for heat source 25 and the heat exchanger for auxiliary heating 29 is allowed to flow, thereby flowing through the heat medium circulation path 22. The heating medium is configured to be heated. The said heat consumption terminal 3 is comprised by heating terminals, such as a floor heating apparatus and a bathroom heating apparatus.

  Further, a hot water supply load measuring means 31 for measuring the hot water supply heat load when supplying hot water taken out from the hot water tank 2 is provided, and a terminal thermal load measuring means 32 for measuring the terminal heat load at the heat consuming terminal 3 is also provided. ing. In addition, a heat load means a load calorie | heat amount.

The hot water tank 2 stores hot water in a state where temperature stratification is formed, and for detecting the amount of hot water stored in the hot water tank 2, an upper end temperature sensor S1 for detecting the temperature of hot water at the upper end position of the upper layer portion, Middle upper temperature sensor S2 for detecting the temperature of hot water at the boundary position between the upper layer portion and the middle layer portion, middle lower temperature sensor S3 for detecting the temperature of hot water at the boundary position between the middle layer portion and the lower layer portion, and the lower end of the lower layer portion A lower end temperature sensor S4 for detecting the temperature of the hot water at the position is provided.
Furthermore, a feed water temperature sensor Si for detecting the feed water temperature of the water supplied to the hot water tank 2 is also provided.

  The operation control unit 5 controls the operation of the fuel cell 1 and the operation state of the cooling water circulation pump 15 while operating the cooling water circulation pump 15 during the operation of the fuel cell 1, as well as the hot water circulation pump 17 and the heat source. By controlling the operating state of the circulation pump 21 and the heat medium circulation pump 23, a hot water storage operation for storing hot water in the hot water storage tank 2 and a heat medium supply operation for supplying the heat medium to the heat consuming terminal 3 are performed. Has been.

By the way, when hot water is supplied, the hot water taken out from the hot water tank 2 with the heat source intermittent valve 40 closed is configured to supply hot water, and the hot water taken out from the hot water tank 2 is heated by the auxiliary heating means M, Water is mixed with hot water taken out from the hot water storage tank 2, and hot water at a hot water supply set temperature set by a remote controller (not shown) is supplied.
Therefore, in the hot water tank 2, hot water is stored within the capacity of the hot water tank 2 by subtracting the hot water taken out for hot water supply from the hot water added according to the output of the fuel cell 1. become.

  The operation control unit 5 manages past power load data and past heat load data, and performs the planned operation of the fuel cell 1 based on the past power load data and past heat load data. It is configured.

Next, a description will be given of the control of the operation of the fuel cell 1 by the operation control unit 5.
The operation control unit 5 defines an intermittent operation mode (corresponding to an intermittent operation) in which the fuel cell 1 is intermittently operated by setting an operation time zone within an operation cycle (24 hours in this embodiment) consisting of a plurality of hours. It is configured to repeat every operation cycle.

And the operation control part 5 is comprised so that the said operation time slot | zone may be set to the time slot | zone which becomes the most energy saving in the said operation period based on the prediction electric power load and prediction heat load of the said operation period. .
Hereinafter, the intermittent operation mode in which the operation time period is set in this way may be referred to as a first intermittent operation mode.

In addition, the operation control unit 5 has an operation time zone within a first operation cycle among a plurality of continuous (for example, two or three) operation cycles, and the predicted power load of the first operation cycle and the plurality On the basis of the predicted heat load of the operation cycle, it is configured to set the time zone in which energy is saved most.
Hereinafter, the intermittent operation mode in which the operation time zone is set in this way may be referred to as a second intermittent operation mode.

In the first embodiment, as the operation mode of the fuel cell 1, that is, the operation mode, in addition to the intermittent operation mode, a continuous operation mode in which the fuel cell 1 is operated in all time zones within the operation cycle is provided. ing.
Further, a standby mode is provided in which the fuel cell 1 is stopped in all time zones within the operation cycle without executing any of the intermittent operation mode and the continuous operation mode.

  Then, the operation control unit 5 stops the fuel cell 1 at the start of the operation cycle based on the amount of hot water stored in the hot water tank 2 at the start time and the predicted heat load in the next operation cycle, that is, standby. It is determined whether or not a standby condition for executing the mode is satisfied, and when it is determined that the standby condition is satisfied, the standby mode is executed in the next operation cycle.

  In the first embodiment, the operation control unit 5 is configured to select either the intermittent operation mode or the continuous operation mode based on the operation determination condition at the start of the operation cycle, and When the intermittent operation mode is selected, it is configured to determine whether or not the standby condition is satisfied.

  Furthermore, when the stop condition for stopping the operation of the fuel cell 1 is satisfied during the execution of the intermittent operation mode, the operation control unit 5 continues the operation of the fuel cell 1 when the operation continuation condition is satisfied. It is configured as follows.

The operation control unit 5 is configured to track the output of the fuel cell 1 with respect to the currently requested current power load during the operation of the fuel cell 1 in both the intermittent operation mode and the continuous operation mode. Executes the main operation control set to the main output.
Specifically, the operation control unit 5 obtains the current power load for each relatively short predetermined output adjustment period such as one minute in the main operation control, and from the minimum output (for example, 250 W) to the maximum output (for example, 1000 W). ) Within the range, the main output following the current power load is determined continuously as shown in FIG. 3A or stepwise as shown in FIG. Set the output of 1 to the determined main output. The minimum output may be set to 0 W or an extremely small output close to it within an allowable range.

  The current power load is obtained 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 obtained as an average value of the power load in the previous output adjustment cycle. Further, the main output set as the output of the fuel cell 1 is set to be at least a predetermined margin smaller than the current power load.

Further, the operation control unit 5 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 an operation pattern of a certain fuel cell 1.
In the first embodiment, it is assumed that the operation control unit 5 executes the intermittent operation mode in the next operation cycle based on the predicted power load and the predicted heat load of the next operation cycle at the start of the operation cycle. Calculating the predicted energy reduction amount, which is the energy reduction amount when the operation is performed, and the predicted energy reduction amount, which is the energy reduction amount when it is assumed that the continuous operation mode is executed in the next operation cycle, It is configured to select either the intermittent operation mode or the continuous operation mode, with the condition for selecting the better one of the predicted energy reduction amounts of the continuous operation mode as the operation determination condition.

Hereinafter, a method of calculating the predicted energy reduction amount by the operation control unit 5 will be described.
The operation control unit 5 first calculates the time-series predicted power load and the predicted heat load after the start of the operation cycle as shown in FIG. 4 based on the time-series past power load data and heat load data. Predict. Next, assuming that the main operation control is executed for the predicted power load in a mode in which the fuel cell 1 is operated in the operation time zone in the preset temporary operation pattern, the time series prediction of the fuel cell 1 is performed. Calculate generated power and predicted heat generation.

  Then, as shown in the following [Equation 1], the operation control unit 5 uses the energy consumption amount when the fuel cell 1 is not operated as a reference, and the energy consumption amount when the fuel cell 1 is operated in the temporary operation pattern. Can be calculated as the predicted energy reduction amount.

[Equation 1]
Predicted energy reduction amount P = energy consumption amount E2 when the fuel cell 1 is not operated E1-energy consumption amount E2 when the fuel cell 1 is operated

  The energy consumption E1 when the fuel cell 1 is not operated is as shown in the following [Equation 2] in the commercial power source 7 when all of the predicted power load is supplemented with the received power from the commercial power source 7. It is obtained as the sum of the energy consumption amount and the energy consumption amount when all of the predicted heat load is supplemented with the heat generated by the auxiliary heating means M.

[Equation 2]
E1 = predicted power load / power generation efficiency of commercial power source 7 + standby power of cogeneration system / power generation efficiency of commercial power source 7 + predicted heat load / heat generation efficiency of auxiliary heating means M

  On the other hand, the energy consumption E2 when the fuel cell 1 is operated is a case where the predicted power load and the predicted heat load are supplemented with the predicted generated power and the predicted generated heat of the fuel cell 1 as shown in [Formula 3] below. Energy consumption (fuel consumption) in the fuel cell 1 and energy consumption in the commercial power source 7 when the shortage load corresponding to the predicted power load minus the predicted generated power is supplemented with the received power from the commercial power source 7 As the sum of the amount of energy consumed when supplementing the heat generated by the auxiliary heating means M with the insufficient heat load corresponding to the amount obtained by subtracting the predicted generated heat from the predicted heat load, and the energy loss at the start of the fuel cell 1 Desired.

[Equation 3]
E2 = fuel consumption when the fuel cell 1 is operated + insufficient power load / power generation efficiency of the commercial power source 7 + insufficient heat load / heat generation efficiency of the auxiliary heating means M + energy loss at startup + standby power of the cogeneration system / Power generation efficiency of commercial power supply 7

Incidentally, the standby power of the cogeneration system in Equations 2 and 3 is the power consumed by the cogeneration system when the fuel cell 1 is stopped, and the standby power of the cogeneration system in the continuous operation mode is zero. The standby power of the cogeneration system in the intermittent operation mode is power obtained by multiplying the standby power per hour by the time obtained by subtracting the operation time zone from the operation cycle.
The standby power of the cogeneration system may be standby power of the fuel cell 1.

  A method for obtaining the energy consumption E2 when the fuel cell 1 as described above is operated will be described.

  As shown in FIG. 5 (a), the predicted power load (a) and the predicted heat load (m) were obtained at each hour in the 24-hour operation cycle from the determination timing, and the operation time zone was set. The main output (b) of the fuel cell 1 set in the operation time zone set in the temporary operation pattern is obtained in a form that follows the predicted power load (a). At this time, if the predicted power load is less than or equal to the minimum output of the fuel cell 1, the main output (b) is set to the minimum output and the difference is obtained as the surplus power (i). It is done. On the other hand, when the predicted power load is equal to or greater than the maximum output of the fuel cell 1, the main output (b) is set to the maximum output and the difference is obtained as the insufficient power amount (c).

  At each time, the fuel consumption (g), which is the primary energy consumption of the fuel cell 1, is obtained from the main output (b) and the power generation efficiency (e) of the fuel cell 1, and the fuel consumption (g). The amount of heat generated (d) of the fuel cell 1 is obtained from the heat generation efficiency (f) of the fuel cell 1.

  Furthermore, in each time, within the range below the maximum capacity of the hot water tank 2, the amount of heat generated (d) minus the exhaust heat loss (h) is integrated, and the surplus power ( From the amount of heat generated by the electric heater 12 obtained from i), the stored heat dissipation amount (l) radiated in the hot water tank 2, and the predicted usage heat amount (n) used as the predicted heat load (m), The amount of hot water stored in the hot water tank 2 (k) is obtained as the amount obtained by subtracting the amount of heat, and the amount of heat exceeding the maximum capacity of the hot water tank 2 is obtained as the surplus heat amount (j) radiated by the radiator 19.

  And the shortage calculated | required as the difference when the sum total of the said fuel consumption (g) in the determination object period, the sum of shortage electric energy (c), and hot water storage calorie | heat amount (k) are smaller than prediction use calorie | heat amount (n) By substituting the total heat load and the energy loss at startup into the above [Equation 3], the energy consumption amount E2 when the fuel cell 1 as described above is operated can be obtained.

  Incidentally, the energy loss at the time of startup of the fuel cell 1 is unique to the fuel cell 1 and is obtained in advance by experiments or the like and stored in the operation control unit 1.

  It should be noted that the sum of the total heat generation amount (d) of the fuel cell 1 and the total heat generation amount of the electric heater 12 obtained from the surplus power amount (i) is recognized as the total heat generation amount of the fuel cell 1. Further, the sum of each of the exhaust heat loss (h), the surplus heat amount (j), and the hot water storage heat dissipation amount (l), preferably the start-up loss, is recognized as the total heat loss of the fuel cell 1. can do. When all of the heat amount obtained by subtracting the total heat loss from the total heat generation amount can be used as a heat load, the predicted energy reduction amount is maximized, and the use heat amount that maximizes the predicted energy reduction amount is peaked. Called heat utilization.

  The operation control unit 5 stores the load data for a plurality of unit periods obtained by dividing one day into a plurality of unit periods in a non-volatile memory 34 as a storage unit for a plurality of past days in a state where each day is divided in order of time passage. The data storage process is executed.

  That is, the operation control unit 5 uses, for example, a thermal load as a hot water supply thermal load and a terminal thermal load, and converts an actual power load per unit time, an actual hot water load, and an actual terminal thermal load into the power load measuring unit 11 and Measurement is performed by the output value of the inverter 6, the hot water supply thermal load measuring means 31, and the terminal thermal load measuring means 32. Then, the output values of the power load measuring means 11 and the inverter 6, the hot water supply thermal load measuring means 31, and the values measured by the terminal thermal load measuring means 32 for the past three weeks (21 days) By storing in the memory 34 in a state of being sorted for each day in order, the time-series power load and the time-series heat load are managed every hour as an example of a unit period.

Next, a description will be given of a method of calculating the amount of stored hot water in the hot water tank 2 by the operation control unit 5.
The hot water temperatures 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 are T1, T2, T3, and T4, respectively. Let the water supply temperature detected by the water supply temperature sensor Si be Ti.
Further, assuming that the weighting coefficient in the upper layer part is A1, the weighting coefficient in the middle layer part is A2, and the weighting coefficient in the lower layer part is A3, the stored hot water heat quantity Q can be calculated by the following [Equation 4]. it can.

[Equation 4]
Q = {(A1 * T1 + (1-A1) * T2-Ti) * 50
+ (A2 * T2 + (1-A2) * T3-Ti) * 50
+ (A3 * T3 + (1-A3) * T4-Ti) * 50} * 4186.05

  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.

Next, the continuous operation mode will be described.
As described above, the operation control unit 5 sets the output of the fuel cell 1 to the main output that follows the current power load currently requested, that is, executes the main operation control as the continuous operation mode. When the load surplus continuous operation mode and the load follow continuous operation mode are executed to predict a surplus heat state in which the generated heat of the fuel cell 1 is excessive with respect to the heat load, the output of the fuel cell 1 is The suppression continuous operation mode is set such that the suppression output is set to be smaller than the main output following the current power load.

  Incidentally, the excess heat state means, for example, that 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 1 during the heat medium supply operation is consumed. The hot water stored in the hot water tank 2 is larger than the terminal thermal load required at the terminal 3 and the radiator 19 is in operation.

Next, explanation will be given on the prediction of the excess heat state.
The operation control unit 5 obtains the predicted power load and the predicted heat load in the operation cycle, and generates the fuel cell 1 on the assumption that the main operation control is continuously performed so as to compensate for the predicted power load. It is determined whether or not a surplus heat state occurs with respect to the predicted heat load, and a time zone in which the heat surplus state occurs is obtained as a heat surplus time zone.
In addition, about the structure which estimates a heat surplus state, for example, the amount of hot water supply in the state which actuated the auxiliary heating means M, and the heat dissipation in the radiator 19 are integrated | accumulated, and a heat surplus is obtained by the integrated value becoming more than a setting value. Changes can be made as appropriate, such as predicting the state.

  When the suppression continuous operation mode is described further, the operation control unit 5 performs the suppression continuous operation mode so that the remaining heat state is in a time zone before the remaining heat time zone in which the remaining heat state is predicted. In the suppression operation time zone set so as to be eliminated, the output of the fuel cell 1 is set to a suppression output smaller than the main output.

  Further, the suppression output is set to the maximum output within the range below the main output among the outputs that exhibit the power generation merit superior to the power generation merit when the output of the fuel cell 1 is set to the main output. It is desirable.

  That is, the operation control unit 5 uses the energy consumption when all the current power load is supplemented with the received power from the commercial power supply 7 and the energy consumption when at least a part of the current power load is supplemented with the generated power of the fuel cell 1. The above power generation merit corresponding to the amount obtained by subtracting the amount is calculated when the output of the fuel cell 1 is set to the main output and lower, and the power generation merit sets the output of the fuel cell 1 to the main output. The maximum output among the outputs superior to the case is set as the suppression output. The power generation merit is desirably a value obtained by subtracting energy loss due to generation of surplus power. Note that the suppression output may be a minimum output of the fuel cell 1 or an output that is a predetermined set amount smaller than the main output.

  Further, the suppression output may be set as an output that exhibits an overall power generation merit that is superior to the total merit that is the sum of the power generation merit and the heat generation merit when the output of the fuel cell 1 is set to the main output. .

Next, a method for setting an operation time zone in the intermittent operation mode will be described.
In the first intermittent operation mode, a predicted energy reduction amount of each of a plurality of temporary operation patterns having different operation time zones of the fuel cell 1 within the operation cycle is calculated based on the predicted power load and the predicted heat load in the operation cycle. The start time and stop time of the fuel cell 1 are set within the operation cycle so that the predicted energy reduction amount is maximized.

That is, as shown in FIG. 6, the temporary operation pattern is a pattern in which the fuel cell 1 is operated once within an operation cycle (24 hours in this embodiment).
For example, assuming that the starting point of the driving cycle is 3:00 am, as a pattern for starting driving from 3:00 am to 4:00 am (time zone 1), the time from 3:00 am to 4:00 am (time zone “1” )) Only in pattern 1 (starting time is 3:00 am, stopping time is 4:00 am) and driving only from 3 am to 5 am (time zones “1” and “2”) Pattern 2 (Start-up time is 3:00 am, stop time is 5:00 am), and only the time zone from 3:00 am to 6:00 am (time zones “1”, “2” and “3”) is operated. There are 24 types of patterns 24 that are operated in the time zone from 3 am to 3 am on the next day (time zones “1” to “24”). Further, as a pattern for starting operation from 4:00 am to 5:00 am (time zone “2”), a pattern 25 for driving only this time zone “2”, a time zone from 4 am to 6 am ( Pattern 26 for driving time zones “2” and “3”) 23 of pattern 47 for driving the time zone from 4 am to 3 am on the next day (time zones “2” to “24”) There are types. In this way, from the last 2 am to 3 am of the driving cycle (time zone “24”) to the pattern 300 of the pattern for starting operation, the temporary operation patterns are 300 types from pattern 1 to pattern 300. There are things.
Such 300 kinds of temporary operation patterns are stored in the memory 34.

  Then, the operation control unit 5 performs prediction by executing the main operation control on the fuel cell 1 in the operation time period from the start time to the stop time for all the temporary operation patterns stored in the memory 34. The energy reduction amount is calculated using the above-described [Equation 1] to [Equation 3].

  Then, among the plurality of temporary operation patterns, the temporary operation pattern having the best predicted energy reduction amount obtained as described above, that is, the maximum temporary operation pattern is determined as a formal operation pattern in the operation cycle, and the operation pattern is The start time and stop time of the fuel cell 1 within the operation cycle are set so that the fuel cell 1 is operated in the defined operation time zone.

  In the second intermittent operation mode, the predicted energy reduction amount of each of the plurality of temporary operation patterns in which the operation time zones of the fuel cell 1 are different within the operation cycle, the predicted power load in the operation cycle, and the heat load that is the plurality of operation cycles. The start time and stop time of the fuel cell 1 are set within the operation cycle so that the predicted energy reduction amount is maximized by calculation based on the predicted heat load in the determination target period.

  That is, the operation control unit 5 performs prediction by executing the main operation control on the fuel cell 1 in the operation time period from the start time to the stop time for all the temporary operation patterns stored in the memory 34. Calculate energy savings.

  The predicted energy reduction amount calculated in the second intermittent operation mode is, for example, a thermal load determination target period including the operation cycle as shown in the heat utilization state after the first operation cycle in FIG. Assuming the case where the amount of stored hot water (k) is continuously used as the predicted heat load (m), the first operation cycle calculated using the above-described [Equation 1] to [Equation 3] etc. The amount of heat that is calculated by subtracting the total amount of stored hot water (1) from the total amount of predicted usage heat (n) after the first operation cycle for the predicted energy reduction calculated based on the power load and the predicted heat load Can be obtained as a value obtained by adding the energy consumption when supplementing with the heat generated by the auxiliary heating means M.

The operation control unit 5 is configured to execute an operation mode selection process for selecting one of the intermittent operation mode and the continuous operation mode or the standby mode at the start of the operation cycle.
The operation mode selection process will be described below based on the flowchart shown in FIG.
Even if the fuel cell 1 is stopped, energy (electric power) is consumed, for example, to keep it in a state where power generation is possible, and the fuel cell 1 in all time zones within the operation cycle. The energy consumed in the cogeneration system when the operation is stopped is obtained in advance by experiments or the like and stored in the operation control unit 5 as standby energy consumption Z.

  When the operation control unit 5 reaches the start point of the operation cycle (for example, 3:00 am), the predicted energy reduction amount Pc (hereinafter, predicted energy in the continuous operation mode) when it is assumed that the fuel cell 1 is operated in the continuous operation mode. And may be described as a predicted energy reduction amount Pi when the fuel cell 1 is operated in the intermittent operation mode (hereinafter referred to as a predicted energy reduction amount Pi in the intermittent operation mode). ) And determining whether the larger one of them is larger than the negative value “−Z” of the standby energy consumption Z, so that one of the continuous operation mode and the intermittent operation mode is determined. It is determined whether or not the person who executed is energy saving rather than executing the standby mode (steps # 1 to # 3).

Incidentally, the predicted energy reduction amount Pc in the continuous operation mode is calculated for each of the load following continuous operation mode and the suppression continuous operation mode, and the larger one of them is used as the predicted energy reduction amount Pc in the continuous operation mode. The predicted energy reduction amount Pi in the intermittent operation mode is calculated for each of the first intermittent operation mode and the second intermittent operation mode, and the larger one of them is calculated as the predicted energy reduction amount Pi in the intermittent operation mode. Is configured to do.

  That is, the energy consumption amount when the continuous operation mode or the intermittent operation mode is executed is larger than the energy consumption amount when the fuel cell 1 is not operated, and the predicted energy reduction amount Pc in the continuous operation mode or the intermittent operation mode The predicted energy reduction amount Pi may be obtained as a negative value, but the continuous operation mode is not dependent on whether the predicted energy reduction amount Pc in the continuous operation mode or the predicted energy reduction amount Pi in the intermittent operation mode is positive or negative. When the larger one of the predicted energy reduction amount Pc and the predicted energy reduction amount P in the intermittent operation mode is larger than the negative value “−Z” of the standby energy consumption Z, the continuous operation mode and the intermittent operation mode When one of the above is executed, energy is saved rather than when the standby mode is executed.

  If it is determined in step # 3 that energy saving is greater when executing either the continuous operation mode or the intermittent operation mode than when executing the standby mode, the operation is performed during the intermittent operation mode in step # 4. The predicted energy reduction amount Pi in the continuous operation mode is compared with the predicted energy reduction amount Pc in the continuous operation mode to determine whether the predicted energy reduction amount Pc in the continuous operation mode is equal to the predicted energy reduction amount Pi in the intermittent operation mode. When it is larger than the predicted energy reduction amount Pi in the mode, the continuous operation mode is selected (step # 5), and the predicted energy reduction amount Pi in the intermittent operation mode is more than the predicted energy reduction amount Pc in the continuous operation mode. Is larger, the intermittent operation mode is selected, and as will be described later, it is determined whether or not the standby condition is satisfied (steps # 6 and # 7). At step # 3, when a person who executes the standby mode than to perform any of the continuous operation mode and the intermittent operation mode is determined to be the energy saving selects the standby mode (step # 11).

  That is, any one of the intermittent operation mode, the continuous operation mode, and the standby mode is selected with the condition for selecting the one having an excellent predicted energy reduction amount among the intermittent operation mode, the continuous operation mode, and the standby mode as the operation determination condition. Will choose one.

  In step # 6, as shown in FIG. 5B, the predicted thermal load (m) of each time of the next operation cycle is summed to obtain the predicted thermal load L of the next operation cycle, and FIG. As shown in (b), the predicted use heat amount (n) of each time of the next operation cycle is summed and used as the predicted heat load of the next operation cycle out of the hot water storage amount of the hot water storage tank 2 at the start time. In addition to obtaining the predicted use heat amount U, the ratio U / L is obtained as a heat load coverage rate that indicates the extent to which the predicted heat load of the next operation cycle can be covered by the hot water storage heat amount at the start time. The thermal load coverage rate U / L and the upper set value K are compared, and if the thermal load coverage rate U / L is greater than the upper set value K, it is determined that the standby condition is satisfied, and the thermal load coverage rate U When / L is equal to or lower than the upper set value K, it is determined that the standby condition is not satisfied. Incidentally, the upper set value K is set to 0.6, for example.

  In other words, since there is heat dissipation from the hot water tank 2, in obtaining the thermal load bridging rate, the amount of hot water stored in the hot water tank 2 at the start of the next operation cycle is used instead of the amount of hot water stored in FIG. As shown in the figure, the heat usage from the hot water storage tank 2 is taken into account by using the predicted use heat amount U that is used as the predicted heat load of the next operation cycle out of the hot water storage amount of the hot water storage tank 2 at the start of the next operation cycle. Therefore, it is possible to appropriately obtain the thermal load bribery rate.

  If it is determined in step # 7 that the standby condition is satisfied, it is determined in step # 8 whether or not the fuel cell 1 is in operation. 9 out of the operation merits for each operation duration obtained by varying the operation duration based on the predicted power load and predicted heat load of the next operation cycle, which is superior to stopping the operation of the fuel cell 1. It is determined whether or not the operation continuation condition, which is a condition for which the operation continuation time exists, is satisfied. When the operation continuation condition is satisfied, the operation of the fuel cell 1 is continued (step # 10) and the operation continuation condition is satisfied. If not, the standby mode is selected (step # 11).

That is, when the fuel cell 1 is in operation at the start time of the operation cycle, the stop condition is that the amount of stored hot water in the hot water tank 2 at the start time and the predicted heat load in the next operation cycle are This is a condition that satisfies the waiting condition for waiting for driving.
The standby condition is set such that the thermal load coverage rate indicating the extent to which the amount of stored hot water at the start time can cover the predicted thermal load in the next operation cycle is larger than a set value.

  In Step # 9, all the operation durations (including 0 hours) in the unit of 1 hour within the set maximum operation duration shorter than the operation cycle are based on the predicted power load and the predicted heat load of the next operation cycle. , [Equation 1] to [Equation 3] are used to calculate the predicted energy reduction amount, and the operation duration time is 0 hour, that is, the predicted energy reduction amount is larger than the predicted energy reduction amount when the fuel cell 1 is not operated. When the operation continuation time exists, it is determined that the operation continuation condition is satisfied, and when it does not exist, it is determined that the operation continuation condition is not satisfied.

  When the operation of the fuel cell 1 is continued, the startup energy is not consumed. Therefore, in step # 9, when calculating the predicted energy reduction amount for each operation continuation time of 1 hour or more, the startup energy is not calculated. Zero energy loss.

For example, if the set maximum operation duration is set to 3 hours, the predicted energy reduction amount is calculated for each of the operation durations of 1 hour, 2 hours, and 3 hours.
When the operation continuation time is 1 hour, the main operation control that follows the predicted power load of the first hour in the next operation cycle is executed. When the operation continuation time is 2 hours, 1 in the next operation cycle Assuming that the main operation control that follows the predicted power load at the second and second hours is executed, when the operation duration is three hours, the prediction at the first, second, and third hours in the next operation cycle Assuming that the main operation control that follows the power load is executed, the predicted energy reduction amount is calculated.

  In step # 10, the amount of heat generated from the fuel cell 1 due to the continuation of the operation of the fuel cell 1 is operated by operating the fuel cell 1 during the operation continuation time in which the predicted energy reduction amount is the largest in step # 9. The operation of the fuel cell 1 is continued until the amount of heat predicted to be generated from the fuel cell 1 is reached, and when the amount of heat is reached, the fuel cell 1 is stopped.

  The amount of heat generated from the fuel cell 1 and the amount of heat predicted to be generated from the fuel cell 1 may include the amount of heat generated from the electric heater 12.

In other words, the operation of the fuel cell 1 is stopped among the operation merits for each operation continuation time obtained by the operation continuation condition being determined by changing the operation continuation time based on the predicted power load and predicted heat load of the next operation cycle. It is a condition that there is an operation duration that is better than
The different driving continuation times for obtaining the driving merit are shorter than the driving cycle.

  Further, the operation control unit 5 operates from the fuel cell 1 by operating the fuel cell 1 during the operation continuation time in which the amount of heat generated from the fuel cell 1 due to the continuation of the operation of the fuel cell 1 is the best in the operation merit. The fuel cell 1 is configured to stop when the amount of heat expected to be generated is reached.

  Even if it is determined in step # 7 that the standby condition is satisfied, if the fuel cell 1 is not in operation in step # 8, the standby mode is selected (step # 11).

When it is determined in step # 7 that the standby condition is not satisfied, in step # 12, the thermal load coverage ratio U / L is compared with the lower set value M smaller than the upper set value K, and the heat load is covered. When the rate U / L is larger than the lower set value M, the standby mode is selected (step # 11), and when the thermal load coverage rate U / L is lower than the lower set value M, the first intermittent operation mode and the first The operation time zone is set so that the predicted energy reduction amount is maximized for each of the two intermittent operation modes, and the intermittent operation mode with the larger predicted energy reduction amount is selected (step # 13).
Incidentally, the lower setting value M is set to 0.4, for example.

That is, when the thermal load coverage rate U / L is larger than the upper set value K, the fuel cell 1 can be improved when the operation of the fuel cell 1 is continued. When the operation continuation condition is satisfied, the operation of the fuel cell 1 is continued.
Further, when the thermal load coverage rate U / L is lower than the upper set value K and does not satisfy the operation continuation condition, and the thermal load coverage rate U / L is greater than the lower set value M, the operation of the fuel cell 1 is continued. Although there is little possibility of improving energy saving even if it is made, it is assumed that the thermal load of the next operation cycle can be covered to some extent, and the operation of the fuel cell 1 is put on standby in the next operation cycle.
Further, when the thermal load coverage rate U / L is less than the upper set value K and does not satisfy the operation continuation condition, and when the thermal load coverage rate U / L is less than the lower set value M, the next operation cycle Assuming that there is a possibility that excessive heat shortage may occur when the fuel cell 1 is put on standby, the operation time zone is newly reset and the intermittent operation is executed.

  That is, when the standby condition is not satisfied at the start point of the operation cycle, the operation control unit 5 sets the operation time zone within the first operation cycle among the plurality of continuous operation cycles, Based on the time period in which the operation merit obtained based on the predicted power load of the operation cycle and the predicted heat load of the first operation cycle is excellent, and the predicted power load of the first operation cycle and the predicted heat load of the plurality of operation cycles Among the time zones in which the driving merit is excellent, the time zone in which the driving merit is more excellent is set.

  When the intermittent operation mode is selected in the operation mode selection process, the operation control unit 5 operates the fuel cell 1 during the operation time period in the next operation cycle, and continuously operates in the operation mode selection process. When the mode is selected, the fuel cell 1 is operated in all time zones within the next operation cycle, and when the standby mode is selected in the operation mode selection process, the fuel cells are operated in all time zones within the next operation cycle. Stop 1 without driving.

And when performing the 2nd intermittent operation mode, it judges whether a standby condition is satisfied for every starting time of an operation cycle, for example, in the first operation cycle in a plurality of continuous cycles. If the actual heat load is greater than the predicted heat load and it is determined that the standby condition is not satisfied at the start of the second operation cycle among a plurality of continuous operation cycles, the thermal load coverage rate U / L is When it is larger than the lower set value M, the second operation cycle executes the standby mode. When the thermal load coverage ratio U / L is lower than the lower set value M, the second operation cycle is set to the standby mode. Is set, and a fuel cell is newly set in the operation time zone in which the predicted energy reduction amount is superior in the first intermittent operation mode and the second intermittent operation mode. 1 will be driven.

  On the other hand, the actual heat load in the first operation cycle is equal to or less than the predicted heat load, and the fuel cell 1 is operated at the start of the second operation cycle among a plurality of continuous operation cycles. If the stop condition is satisfied when the standby condition is satisfied while the vehicle is in operation, it is determined whether or not the operation continuation condition is satisfied. If the operation continuation condition is satisfied, the operation of the fuel cell 1 is continued. Is not satisfied, the operation of the fuel cell 1 is put on standby in the next operation cycle.

Similarly, when executing the first intermittent operation mode, it is determined whether or not the standby condition is satisfied at each start point of the operation cycle, but in most cases, it is determined that the standby condition is not satisfied. Moreover, in most cases, since the thermal load coverage ratio U / L is equal to or lower than the lower set value M, the next operation cycle is the predicted energy reduction amount in the first intermittent operation mode and the second intermittent operation mode. The operation time zone of which is better is set, and the fuel cell 1 is operated in the operation time zone.

In addition, when the first intermittent operation mode is executed, if it is determined that the actual thermal load is considerably less than the predicted thermal load and the standby condition is satisfied at the start of the operation cycle, the second intermittent operation as described above is performed. The same processing as in the operation mode is performed.

  When the intermittent operation mode is selected by the operation mode selection process, the operation control unit 5 performs the intermittent operation with the predicted energy reduction amount that is superior between the first intermittent operation mode and the second intermittent operation mode. The operation mode is selected and the fuel cell 1 is operated intermittently. For example, when the second intermittent operation mode is selected preferentially, the predicted energy reduction amount of the second intermittent operation mode is: You may comprise so that 2nd intermittent operation mode may be selected when it is larger than the part which deducted a fixed amount from the prediction energy reduction amount of 1st intermittent operation mode.

  Further, when the operation control unit 5 selects the continuous operation mode in the operation mode selection process, the continuous operation mode in which the predicted energy reduction amount is superior between the load following continuous operation mode and the suppression continuous operation mode. Then, the fuel cell 1 is operated.

  Further, when it is more energy saving to execute the standby mode than to execute either the continuous operation mode or the intermittent operation mode, the standby mode is selected and the fuel cell 1 in the entire time period of the next operation cycle. Therefore, the inconvenience that the fuel cell 1 is operated and the excess heat is generated although the heat load is considerably small is avoided.

  Hereinafter, although each of the second to fourth embodiments of the present invention will be described, these embodiments describe other embodiments of the control operation of the operation control unit 5 and are configured of a cogeneration system. Since this is the same as in the first embodiment, description of the configuration of the cogeneration system is omitted, and the control operation of the operation control unit 5 will be mainly described.

[Second Embodiment]
In the second embodiment, the operation determination condition for selecting either the intermittent operation mode or the continuous operation mode in the mode selection process is different from that in the first embodiment.
That is, based on the predicted power load and predicted heat load of the next operation cycle, the predicted energy reduction amount, which is the amount of energy reduction when it is assumed that the continuous operation mode is executed in the next operation cycle, is calculated. If the predicted energy reduction amount in the operation mode is greater than zero, the continuous operation mode is set to a condition that is given priority over the intermittent operation mode.

  In addition, when the operation control unit 5 determines that the standby condition is not satisfied in the mode selection process, it is in a time zone in which the operation merit is most excellent when the fuel cell 1 is stopped during the next operation cycle. The fuel cell 1 is configured to stop in the next operation cycle when it is determined whether or not the energy is saved rather than the operation.

Hereinafter, based on the flowchart shown in FIG. 8, an operation mode selection process for selecting either the intermittent operation mode or the continuous operation mode or the standby mode will be described.
The operation control unit 5 calculates the predicted energy reduction amount Pc1 in the load following continuous operation mode and the predicted energy reduction amount Pc2 in the suppression continuous operation mode when the operation cycle starts (for example, 3:00 am). (Steps # 21 and 22), in Step # 23, it is determined whether or not the predicted energy reduction amount Pc1 in the load following continuous operation mode is equal to or greater than zero. However, when the predicted energy reduction amount Pc1 in the load following continuous operation mode is smaller than zero, in step # 25, it is determined whether or not the predicted energy reduction amount Pc2 in the suppression continuous operation mode is zero or more. If it is determined that the value is greater than or equal to zero, the suppression continuous operation mode is selected (step # 24), and the predicted energy reduction amount Pc2 in the suppression continuous operation mode is less than zero. When small, would select intermittent operation mode, as described later, it determines whether the standby condition is satisfied (step # 26, 27).

  That is, if the predicted energy reduction amount in the continuous operation mode is larger than zero, the condition for selecting the continuous operation mode with priority over the intermittent operation mode is set as the operation determination condition, and either the intermittent operation mode or the continuous operation mode is selected. Either one will be selected.

In step # 26, the predicted heat load U used as the predicted heat load of the next operation cycle out of the predicted heat load L of the next operation cycle and the hot water storage amount of the hot water tank 2 at the start of the next operation cycle. And the ratio U / L is obtained as a heat load coverage rate indicating the extent to which the predicted heat load of the next operation cycle can be covered by the amount of stored hot water at the start time, and in step # 27, the obtained heat load Comparing the coverage ratio U / L with the upper set value K, if the thermal load coverage ratio U / L is greater than the upper set value K, it is determined that the standby condition is satisfied, and the thermal load coverage ratio U / L is When it is less than the set value K, it is determined that the standby condition is not satisfied.
If it is determined in step # 27 that the standby condition is satisfied, it is determined in step # 28 whether or not the fuel cell 1 is in operation. 29, out of the operation merits for each operation duration obtained by varying the operation duration based on the predicted power load and the predicted heat load of the next operation cycle, it is superior to stopping the operation of the fuel cell 1. It is determined whether or not the operation continuation condition, which is a condition for which the operation continuation time exists, is satisfied, and when the operation continuation condition is satisfied, the operation of the fuel cell 1 is continued (step # 30), If not, the standby mode is selected (step # 31).

  In step # 29, as in the first embodiment described above, the predicted power load and prediction for the next operation cycle for all the operation durations (including 0 hours) in the unit of one hour within the set longest operation duration time. When the predicted energy reduction amount is calculated based on the thermal load and the operation duration time is 0 hour, that is, when the operation duration time becomes a predicted energy reduction amount larger than the predicted energy reduction amount when the fuel cell 1 is not operated, It is determined that the driving continuation condition is satisfied, and when it does not exist, it is determined that the driving continuation condition is not satisfied.

  Note that, when the operation of the fuel cell 1 is continued, the startup energy is not consumed. Therefore, in step # 29, when calculating the predicted energy reduction amount for each operation continuation time of 1 hour or more, the startup energy is not calculated. Zero energy loss.

  In step # 30, the amount of heat generated from the fuel cell 1 due to the continuation of the operation of the fuel cell 1 is determined by operating the fuel cell 1 during the operation continuation time in which the predicted energy reduction amount is the largest in step # 29. The operation of the fuel cell 1 is continued until the amount of heat predicted to be generated from the fuel cell 1 is reached, and when the amount of heat is reached, the fuel cell 1 is stopped.

  The amount of heat generated from the fuel cell 1 and the amount of heat predicted to be generated from the fuel cell 1 may include the amount of heat generated from the electric heater 12.

  Even if it is determined in step # 27 that the standby condition is satisfied, if the fuel cell 1 is not in operation in step # 28, the standby mode is selected (step # 31).

When it is determined in step # 27 that the standby condition is not satisfied, in step # 32, the thermal load coverage rate U / L is compared with the lower set value M that is smaller than the upper set value K. When the rate U / L is larger than the lower set value M, the standby mode is selected (step # 31), and when the thermal load coverage rate U / L is lower than the lower set value M, the predicted energy in the intermittent operation mode is selected. The reduction amount Pi is calculated (step # 33), and it is determined whether or not the predicted energy reduction amount Pi in the intermittent operation mode is smaller than the negative value “−Z” of the standby energy consumption Z (step # 34). ) When the predicted energy reduction amount Pi in the intermittent operation mode is smaller than the negative value “−Z” of the standby energy consumption Z, it is preferable to stop the fuel cell 1 during the next operation cycle. (I.e. driving advantage) The standby mode is selected (step # 31), and the predicted energy reduction amount Pi in the intermittent operation mode is negative of the standby energy consumption Z. When the value is equal to or greater than “−Z”, it is determined that performing the intermittent operation mode in the next operation cycle saves energy than stopping the fuel cell 1, and the intermittent operation mode is selected (step # 35). .
That is, the operation time zone is set so that the predicted energy reduction amount is maximized for each of the first intermittent operation mode and the second intermittent operation mode, and the intermittent operation mode with the larger predicted energy reduction amount is selected. .

  When the intermittent operation mode is selected in the operation mode selection process, the operation control unit 5 operates the fuel cell 1 during the operation time period in the next operation cycle, and continuously operates in the operation mode selection process. When the mode is selected, the fuel cell 1 is operated in all time zones within the next operation cycle, and when the standby mode is selected in the operation mode selection process, the fuel cells are operated in all time zones within the next operation cycle. Stop 1 without driving.

That is, when the second intermittent operation mode is being executed, it is determined whether or not the standby condition is satisfied at each start point of the operation cycle, for example, in the first operation cycle of a plurality of consecutive cycles. If the actual heat load is greater than the predicted heat load and it is determined that the standby condition is not satisfied at the start of the second operation cycle among a plurality of continuous operation cycles, the thermal load coverage rate U / L is When it is larger than the lower set value M, the second operation cycle executes the standby mode, and when the thermal load coverage rate U / L is lower than the lower set value M, the fuel cell 1 is operated during the next operation cycle. In the case where the stopped person is more energy saving than in the intermittent operation mode, the standby mode is executed, and in the next operation cycle, the intermittent operation mode is more energy efficient than the fuel cell 1 is stopped. If it becomes new To, by setting the operation time period of the person who predicted energy reductions are good among the first intermittent operation mode and the second intermittent operation mode, thereby operating the fuel cell 1 at the operation time zone.

  On the other hand, the actual heat load in the first operation cycle is equal to or less than the predicted heat load, and the fuel cell 1 is operated at the start of the second operation cycle among a plurality of continuous operation cycles. If the stop condition is satisfied when the standby condition is satisfied while the vehicle is in operation, it is determined whether or not the operation continuation condition is satisfied. If the operation continuation condition is satisfied, the operation of the fuel cell 1 is continued. Is not satisfied, the operation of the fuel cell 1 is put on standby in the next operation cycle.

Similarly, when executing the first intermittent operation mode, it is determined whether or not the standby condition is satisfied at each start point of the operation cycle, but in most cases, it is determined that the standby condition is not satisfied. Moreover, in most cases, since the thermal load coverage ratio U / L is lower than the lower set value M, it is more energy saving to stop the fuel cell 1 during the next operation cycle than to execute the intermittent operation mode. In the case where the fuel cell 1 is saved, the standby mode is executed and the intermittent operation mode is executed in the next operation cycle. In this case, the first intermittent operation mode and the second Of the intermittent operation mode, an operation time zone with a better predicted energy reduction amount is set, and the fuel cell 1 is operated in the operation time zone.

In addition, when the first intermittent operation mode is executed, if it is determined that the actual thermal load is considerably less than the predicted thermal load and the standby condition is satisfied at the start of the operation cycle, the second intermittent operation as described above is performed. The same processing as in the operation mode is performed.

[Third Embodiment]
In the third embodiment, only the second intermittent operation mode is provided as the operation mode of the fuel cell 1, that is, the operation mode.
As in the first embodiment, the operation control unit 5 satisfies the operation continuation condition when the stop condition for stopping the operation of the fuel cell 1 is satisfied during the execution of the intermittent operation mode. In this case, the fuel cell 1 is continuously operated.

  In the third embodiment, the stop condition is that the actual amount of heat generated from the fuel cell 1 by operating the fuel cell 1 is changed from the fuel cell 1 by operating the fuel cell 1 during the operation time period. This is a condition that reaches the predicted heat generation amount that is predicted to be generated.

  The amount of heat generated from the electric heater 12 may be included in the actual heat generation amount and the predicted heat generation amount.

Further, the operation continuation condition is a condition in which a thermal coverage index indicating a degree to which a predicted thermal load after that can be covered by a hot water storage amount of the hot water storage tank 2 when the stop condition is satisfied is a set value or less.
In the third embodiment, the predicted predicted use heat amount H1 that is the heat amount after the current time in the predicted use heat amount used as the predicted heat load among the heat amounts generated by operating the fuel cell 1 during the operation time period. And the ratio H2 (i) / H1 of the current predicted use heat amount H2 (i), which is the predicted use heat amount used as the predicted heat load after the present time, of the stored hot water amount of the hot water storage tank 2 as the current heat coverage rate The present thermal coverage rate H2 (i) / H1 is used as the thermal coverage rate index.
When the current coverage ratio H2 (i) / H1 is equal to or less than the continuation determination setting value C (for example, 0.85), the operation continuation condition is determined to be satisfied.

Incidentally, i is incremented by 1 every time 1 hour has elapsed from 0, and every time the operation of the fuel cell 1 is continued for 1 hour, the current predicted use heat amount H2 (i) is calculated, and the current heat coverage rate H2 (I) It is configured to compare / H1 with the set value C for continuation determination and determine whether to stop the fuel cell 1 or not.
Therefore, the current predicted utilization heat amount when the stop condition for determining whether or not the operation continuation condition is satisfied is H2 (0).

The control operation of the operation control unit 5 will be described below based on the flowchart shown in FIG.
When the variable i is set to 0 and the start point of the operation cycle is reached, the operation time zone is set so that the predicted energy reduction amount is maximized, and the fuel cell 1 is predicted to be generated by operating during the operation time zone. The predicted heat generation amount is calculated (steps # 41 to # 44).
Subsequently, when the start time of the operation time zone comes, the operation of the fuel cell 1 is started. Thereafter, the current power load is calculated, and the output of the fuel cell 1 is set to the main output corresponding to the current power load. The main operation control is executed, the actual heat generation amount is calculated by integrating the heat output of the fuel cell 1, and the predicted heat generation amount and the actual heat generation amount are compared (steps # 45 to 50).

  Subsequently, in step # 51, it is determined whether or not the actual heat generation amount is equal to or greater than the predicted heat generation amount. If the actual heat generation amount is equal to or greater than the predicted heat generation amount before the next operation cycle starts, the process is stopped. When it is determined that the condition is satisfied, and in step # 52, when the stop condition is satisfied, that is, when the current predicted use heat amount H2 (0) when i = 0, the current heat coverage rate H2 (0) / H1 Is compared with the setting value C for continuation determination, and when the current heat coverage rate H2 (0) / H1 is equal to or less than the setting value C for continuation determination, it is determined that the operation continuation condition is satisfied and If the current heat coverage rate H2 (0) / H1 is larger than the set value C for continuation determination, the fuel cell 1 is stopped because the operation continuation condition is not satisfied (step # 53), and the next operation At the start of the cycle (step # 54), i = To to (step # 55), the flow returns to step # 43.

  On the other hand, in step # 51, when the next operation cycle starts before the actual heat generation amount exceeds the predicted heat generation amount (step # 56), the fuel cell 1 is stopped (step # 57), and i = 0. (Step # 55), the process returns to Step # 43.

  When it is determined in step # 52 that the operation continuation condition is satisfied and the operation of the fuel cell 1 is continued, i is incremented by 1 every hour until the start of the next operation cycle. (Steps # 58 and 59) Each time the operation of the fuel cell 1 is continued for 1 hour, the current heat coverage rate H2 (i) / H1 is compared with the set value C for continuation determination (Steps # 47 to 52). When the current heat coverage rate H2 (i) / H1 is larger than the continuation determination setting value C, the fuel cell 1 is stopped (step # 53), and when the next operation cycle starts (step # 54). , I = 0 (step # 54), the process returns to step # 43, and before the current heat coverage rate H2 (i) / H1 becomes larger than the set value C for continuation determination, at the start of the next operation cycle. (Step # 58), the fuel cell 1 is stopped Step # 60), in the i = 0 (step # 45), the flow returns to step # 43.

  That is, the operation of the fuel cell 1 is continued until the current thermal coverage ratio H2 (i) / H1 becomes larger than the set value C for continuation determination, and the predicted thermal load of the next operation cycle can be sufficiently covered. It will be.

A specific example will be described with reference to FIGS.
Each of FIGS. 10 to 12 shows the predicted power load (a), the main output (b), the generated heat amount (d) of the fuel cell 1, the fuel consumption (g), the exhaust heat loss (h), the surplus The fuel cell operation status and heat usage status obtained by determining the electric energy (i), hot water storage amount (k), hot water heat release amount (l), predicted heat load (m) and predicted usage heat amount (n) every hour. FIG. 10 shows a case where the operation time zone is set, FIG. 11 shows a case where the actual heat load fluctuates, and FIG. 12 shows a case where the operation of the fuel cell 1 is continued.

As shown in FIGS. 10 and 11, the actual heat load at 18:00, 19:00, and 20:00 increased from the predicted heat load.
Then, as shown in FIG. 11, if the actual heat generation amount is equal to or greater than the predicted heat generation amount at 23:00 and the stop condition is satisfied, the current predicted use heat amount H2 (0) is 2633, as shown in FIG. Since the predicted use heat amount H1 at the time of setting is 4115, the current heat coverage rate H2 (0) / H1 is 0.64, which is less than or equal to 0.85 of the set value C for continuation determination. The fuel cell 1 is continuously operated.

  Then, as shown in FIG. 12, when the operation of the fuel cell 1 is continued for 2 hours at 23:00 and 24:00, the current predicted use heat amount H2 (2) becomes 3843, and the current heat coverage rate H2 (2) / H1. Becomes 0.93, which is larger than the continuation determination setting value C of 0.85, and the fuel cell 1 is stopped.

[Fourth Embodiment]
In the fourth embodiment, only the second intermittent operation mode is provided as the operation mode of the fuel cell 1, that is, the operation mode.
And when the said operation control part 5 judges that the prediction heat load did not generate | occur | produce during the driving | operation of the said fuel cell 1, or the actual heat load was smaller than the prediction heat load, the said hot water storage at the time of the judgment was made. The fuel cell 1 is forcibly stopped when the heat coverage index indicating the degree to which the predicted heat load after that time can be covered by the amount of stored hot water in the tank 2 is equal to or greater than a set value.

In the fourth embodiment, a predicted predicted use heat amount H1 that is a heat amount after the current time in a predicted use heat amount that is used as a predicted heat load among heat amounts generated by operating the fuel cell 1 during the operation time period. And the ratio H2 / H1 to the current predicted heat quantity H2 that is the predicted heat quantity to be used as the predicted heat load after the current time in the hot water storage heat quantity of the current hot water tank 2 is obtained as the current heat cover rate, and the current heat cover The rate H2 / H1 is used as the heat coverage rate index.
The fuel cell 1 is forcibly stopped when the current heat coverage ratio H2 / H1 is equal to or greater than a set value S for determining stop (for example, 1.00).

Hereinafter, the control operation of the operation control unit 5 will be described based on the flowchart shown in FIG.
At the start of the operation cycle, an operation time zone is set so that the predicted energy reduction amount is maximized, and a predicted generated heat amount that is predicted to be generated from the fuel cell 1 by operating during the operation time zone is calculated. (Steps # 71-73).
Subsequently, when the start time of the operation time zone comes, the operation of the fuel cell 1 is started. Thereafter, the current power load is calculated, and the output of the fuel cell 1 is set to the main output corresponding to the current power load. The main operation control is executed, the actual heat generation amount is calculated by integrating the heat output of the fuel cell 1, and the predicted heat generation amount and the actual heat generation amount are compared (steps # 74 to 79).

  Subsequently, in step # 80, it is determined whether or not the actual heat load has become smaller than the predicted heat load. If it is determined that the actual heat load has not decreased, the predicted heat generation amount and the actual heat generation amount are compared (step # 81). In step # 82, it is determined whether the actual heat generation amount is equal to or greater than the predicted heat generation amount. If the actual heat generation amount is equal to or greater than the predicted heat generation amount before the next operation cycle starts, the stop condition is set. It is determined that the fuel cell is satisfied, the fuel cell 1 is stopped (step # 83), and when the next operation cycle starts (step # 84), the process returns to step # 72.

  On the other hand, at step # 82, if the actual heat generation amount becomes equal to or greater than the predicted heat generation amount and the start point of the next operation cycle is reached (step # 85), the fuel cell 1 is stopped (step # 86), and step # 86. Return to 72.

  If it is determined in step # 80 that the actual heat load has become smaller than the predicted heat load, it is determined in step # 87 whether or not the current heat coverage rate H2 / H1 is equal to or greater than the set value S for determining stoppage. When the coverage ratio H2 / H1 is equal to or greater than the stop determination set value S, the fuel cell 1 is forcibly stopped (step # 88), and when the next operation cycle starts (step # 89), the process returns to step # 72. When the current thermal coverage rate H2 / H1 is smaller than the stop determination set value S, the process returns to step # 76 and the subsequent processing is repeated.

A specific example will be described with reference to FIGS. 14 and 15.
14 and 15 show the predicted power load (a), the main output (b), the amount of heat generated (d), the fuel consumption (g), the exhaust heat loss (h), the surplus, respectively. The fuel cell operation status and heat usage status obtained by determining the electric energy (i), hot water storage amount (k), hot water heat release amount (l), predicted heat load (m) and predicted usage heat amount (n) every hour. FIG. FIG. 14 shows a case where the operation time zone is set, and FIG. 15 shows a case where the fuel cell 1 is forcibly stopped when the current heat coverage rate H2 / H1 is equal to or greater than the stop determination set value S. It is.

As shown in FIGS. 14 and 15, the predicted heat load at 18:00 disappeared, and the actual heat load became smaller than the predicted heat load.
Then, as shown in FIG. 15, at 22:00, it was determined that the actual heat load was smaller than the predicted heat load at 18:00 on that day. Then, the predicted predicted use heat amount H1 at the time of 22:00 is 3885, the current predicted use heat amount H2 is 3910, the current heat coverage rate H2 / H1 is 1.006, and the set value for stop determination Since C is 1.00 or more, the fuel cell 1 is forcibly stopped.

[Another embodiment]
Next, another embodiment will be described.
(A) As the standby condition, the condition exemplified in the above embodiment, that is, the thermal load coverage rate indicating the extent to which the predicted thermal load in the next operation cycle can be covered by the amount of stored hot water in the hot water storage tank 2 at the start time is set. It is not limited to conditions larger than the value, and various conditions can be applied.
For example, a condition in which the difference between the amount of stored hot water in the hot water storage tank 2 at the start time and the predicted heat load in the next operation cycle is larger than the set amount can be applied.
Moreover, according to the amount of hot water stored in the hot water storage tank 2, the thermal load coverage rate and the difference may be changed.

(B) OPERATION time zone, instead of setting only one time in the operation cycle, may be set more than once.

(C) The driving merit to be evaluated when setting the driving time zone is not limited to the energy saving such as the predicted energy reduction amount exemplified in each of the above-described embodiments. You may use economies, such as a forehead, and environmental features, such as a predicted amount of carbon dioxide reduction.
Incidentally, the predicted energy cost reduction amount can be obtained by subtracting the energy cost when the fuel cell 1 is operated in the temporary operation pattern from the energy cost when the fuel cell 1 is not operated.
The energy cost when the fuel cell 1 is not operated is the cost of purchasing all of the predicted power load and the standby power of the cogeneration system from the commercial power source 7 and all of the predicted heat load by the auxiliary heating means M. It is calculated as the sum of energy costs (fuel costs) when providing.
On the other hand, the energy cost when the fuel cell 1 is operated is estimated as the energy cost (fuel cost) of the fuel cell 1 when the predicted power load and the predicted heat load are supplemented with the predicted generated power and the predicted generated heat of the fuel cell 1. Cost for purchasing power from the commercial power source 7 for the cogeneration system standby power if the shortage power load corresponding to the amount obtained by subtracting the predicted generated power from the power load and the intermittent operation mode, and the predicted heat consumption from the predicted heat load Is obtained as the sum of the energy cost (fuel cost) in the case where the insufficient heat load corresponding to the amount obtained by subtracting is supplemented with the heat generated by the auxiliary heating means M.

The predicted carbon dioxide reduction amount can be obtained by subtracting the carbon dioxide generation amount when the fuel cell 1 is operated in the temporary operation pattern from the carbon dioxide generation amount when the fuel cell 1 is not operated.
The amount of carbon dioxide generated when the fuel cell 1 is not operated is the amount of carbon dioxide generated when purchasing all of the predicted power load and the standby power of the cogeneration system from the commercial power source 7 and all of the predicted heat load. It is calculated | required as the sum with the carbon dioxide generation amount when it covers with the auxiliary heating means M.
On the other hand, the amount of carbon dioxide generated when the fuel cell 1 is operated is the amount of carbon dioxide generated from the fuel cell 1 when the predicted power load and the predicted heat load are supplemented with the predicted generated power and the predicted generated heat of the fuel cell 1, and The amount of carbon dioxide generated when the power is purchased from the commercial power supply 7 and the estimated thermal load when the cogeneration system standby power is consumed in the intermittent power mode and the insufficient power load equivalent to the predicted power load minus the predicted generated power It is obtained as the sum of the carbon dioxide generation amount when the insufficient heat load corresponding to the amount obtained by subtracting the predicted use heat amount from the heat generated by the auxiliary heating means M is supplemented.

(D) In each of the above third and fourth embodiments, the thermal coverage index is not limited to the current thermal coverage rate H2 / H1 exemplified in each embodiment. The ratio itself between the amount of stored hot water in the hot water tank 2 and the predicted heat load after the present time may be used.

(E) In the above embodiment, when the fuel cell 1 is operated, the main operation control is executed. However, when the fuel cell 1 is operated, the output of the fuel cell 1 is set to a certain level. You may comprise so that the rated operation control set to an output may be performed.

(F) Although the fuel cell 1 is applied in the above-described embodiment as the combined heat and power supply apparatus, in addition to this, for example, various devices such as a configuration in which a generator is driven by a gas engine may be applied. it can.

The block diagram which shows the whole structure of the cogeneration system which concerns on embodiment The block diagram which shows the control structure of the cogeneration system which concerns on embodiment Diagram explaining electric main operation control Diagram showing predicted power load and predicted heat load 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 cycle Diagram explaining temporary operation pattern The figure which shows the flowchart of the control action which concerns on 1st Embodiment. The figure which shows the flowchart of the control action which concerns on 2nd Embodiment. The figure which shows the flowchart of the control action which concerns on 3rd Embodiment. 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 the operation period which concern on 3rd Embodiment. 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 the operation period which concern on 3rd Embodiment. 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 the operation period which concern on 3rd Embodiment. The figure which shows the flowchart of the control action which concerns on 4th Embodiment. 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 which concern on 4th Embodiment. 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 which concern on 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cogeneration apparatus 2 Hot water tank 4 Hot water storage means 5 Operation control means

Claims (13)

A combined heat and power device that generates electric power and heat, a hot water storage device that stores hot water in a hot water storage tank using heat generated by the combined heat and power device, and an operation control device that controls operation, are provided.
The operation control means is a cogeneration system configured to repeat an intermittent operation of intermittently operating the combined heat and power unit by setting an operation time zone within an operation cycle consisting of a plurality of hours at each operation cycle. And
When the operation control means satisfies the operation continuation condition when the stop condition for stopping the operation of the cogeneration device is satisfied, the operation of the cogeneration device is continued , and further, the start point of the operation cycle In the above, the operation time zone is within the first operation cycle among a plurality of continuous operation cycles, and the operation merit obtained based on the predicted power load of the first operation cycle and the predicted heat load of the first operation cycle In the time zone where the operating merit was superior, and the time zone in which the operating merit was determined based on the predicted power load of the first operating cycle and the predicted thermal load of the plurality of operating cycles, the time zone in which the operating merit was more excellent A cogeneration system that is configured to set up. When the cogeneration device is operating at the start of the operation cycle when the stop condition is, the amount of hot water stored in the hot water storage tank at the start time and the predicted heat load in the next operation cycle are The cogeneration system according to claim 1 , wherein the cogeneration system is a condition that satisfies a waiting condition for waiting for driving. Among the operation merits for each operation continuation time that the operation continuation condition is obtained by varying the operation continuation time based on the predicted power load and predicted heat load of the next operation cycle, the operation of the cogeneration device is stopped. The cogeneration system according to claim 2 , wherein the cogeneration system is in a condition that there is an operation continuation time that is superior to the above. The cogeneration system according to claim 3 , wherein the different operation continuation times for obtaining the operation merit are shorter than the operation cycle. The operation control means operates the cogeneration device by operating the cogeneration device for an operation continuation time in which the amount of heat generated from the cogeneration device due to continuation of operation of the cogeneration device is the best operation merit. The cogeneration system according to claim 3 or 4 , wherein the cogeneration system is configured to stop when the amount of heat expected to be generated from the apparatus is reached. When the operation control means does not satisfy the standby condition at the start of the operation cycle, the operation time zone is within the first operation cycle of a plurality of consecutive operation cycles, and the first operation cycle Obtained based on the predicted power load and the predicted heat load of the first operation cycle, the time zone in which the operation merit is excellent, and the predicted power load of the first operation cycle and the predicted heat load of the plurality of operation cycles. The cogeneration system according to any one of claims 2 to 5 , wherein the cogeneration system is configured to perform setting in a time zone in which driving merit is more excellent among time zones in which driving merit is excellent. In the case where the standby condition is not satisfied at the start of the operation cycle, the operation control means stops the combined heat and power unit during the next operation cycle, and operates in an operation time zone in which the operation merit is excellent. The cogeneration system according to claim 6 , wherein the cogeneration system is configured to stop the combined heat and power supply device in the next operation cycle when the operation merit is superior to the operation. The amount of heat that the stop condition is predicted to be generated from the combined heat and power device by operating the combined heat and power device during the operation time period is the amount of heat generated from the combined heat and power device when the combined heat and power device is operated. cogeneration system according to claim 1, wherein the condition is reached. The continuous operation conditions, claim 8, wherein the heat catering degree index indicating the degree to which can cover the subsequent predicted heat load in the hot water storage heat of the hot water storage tank is less condition setting values at the time of the stop condition is satisfied Cogeneration system. The cogeneration system according to any one of claims 1 to 9 , wherein the operation merit is energy saving, economic efficiency, or environmental performance. Wherein when the seek operation advantages of using the continuous operation condition is satisfied is determined whether any one of claim 1 to 10 which is configured to determine the energy loss at the start of the cogeneration unit as a zero Cogeneration system described in 1. Before SL operation control means, during the operation of the cogeneration device, if the predicted heat load is not or actual heat load generated is determined to smaller than expected heat load, the hot water tank at the time the determination was The cogeneration system according to claim 1 , wherein the cogeneration system is configured to forcibly stop the heat and power supply device when a heat coverage index indicating a degree of coverage of a predicted heat load after that time is greater than or equal to a set value. system. As an operation mode of the combined heat and power device, in addition to the intermittent operation, a continuous operation for operating the combined heat and power device in all time zones within the operation cycle is provided,
When the operation control means is configured to select one of the intermittent operation and the continuous operation based on an operation determination condition at the start of the operation cycle, and when the intermittent operation is selected. The cogeneration system according to any one of claims 1 to 12 , wherein the cogeneration system is configured to determine whether or not the operation continuation condition is satisfied when the stop condition is satisfied.

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