JP4810786B2 - Fuel cell cogeneration system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a household fuel cell comprising a control means for storing hot water heated by exhaust heat from a fuel cell that generates electricity and heat in a hot water storage tank and controlling the amount of power generated by the fuel cell. It is about a cogeneration system.
[0002]
[Prior art]
In this type of conventional household fuel cell cogeneration system, heat generated according to the power generated by the fuel cell is temporarily stored in a hot water storage tank and supplied in accordance with hot water supply demand. When there was a lot of hot water supply and the amount of livestock heat in the hot water storage tank was insufficient, hot water was replenished with an auxiliary heating device such as a boiler installed separately.
[0003]
[Problems to be solved by the invention]
However, in the conventional household fuel cell cogeneration system, there is a drawback in that if there is no auxiliary heating device, the user consumes the hot water in the hot water storage tank, causing the hot water to run out, resulting in poor usability. there were.
[0004]
Conventionally, so-called electric main heat slave operation is generally used to control the amount of generated power according to the electric power used, and it is not the heat main electric slave operation mainly considering hot water supply. Did not prioritize.
[0005]
The present invention solves the above-mentioned conventional problems, primarily controlling comfort for hot water supply demand and secondarily considering power demand, thereby preventing hot water shortage and improving system energy saving. An object of the present invention is to provide a fuel cell cogeneration system.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention
A power load detecting means for detecting a power load;
A fuel cell having a battery stack that generates electricity by electrochemically reacting hydrogen and oxygen; and
A hot water storage tank of a circulating stacked boiling type that stores hot water heated by the exhaust heat of the fuel cell;
A water supply channel for connecting to the lower part of the hot water storage tank and supplying city water,
A hot water storage path for circulating water in the hot water storage tank connected to the lower and upper portions of the hot water storage tank ;
A heat exchanger for transferring waste heat of the fuel cell to water in the hot water storage path;
A hot water supply path connected to the upper part of the hot water storage tank;
A hot water storage tank upper temperature detector provided in the upper part of the hot water storage tank;
A hot water storage tank lower temperature detector provided at the lower part of the hot water storage tank;
A water amount detector provided in the middle of the hot water supply path;
Thermal load detection means for detecting a thermal load from the hot water storage tank upper temperature detector and the water amount detector;
A storage unit that stores a power load for each time zone and a heat load for each time zone in a certain period over a plurality of days based on the detected information on the power load and the heat load,
A power load prediction unit and a thermal load prediction unit that average the measurement results in the predetermined period and determine the power load for each time zone and the thermal load model pattern for each time zone and store them in the storage unit,
At the beginning of operation, the operation rate of the fuel cell is controlled corresponding to the power load, and the fuel cell is operated once / day (hereinafter referred to as on / off once control), and the predetermined period of time. When the fuel cell is operated at the operating rate near the upper limit of the rated capacity for one day according to the predicted heat load model pattern for each time zone after the elapse of time, the fuel When exceeding the amount of heat generated by exhaust heat recovery calculated from the amount of power generated by the battery, when the fuel cell is operated at a constant operating rate near the upper limit of the rated capacity for one day continuously after stopping the on / off control once and below, Performs on / off control once and operates the fuel cell at a constant operating rate calculated from the amount of heat load required for one day, and the operation start time is fuel from the heat load use time of the time-dependent heat load model pattern. When the battery startup time is early Determined, the shutdown time control means adapted to determine the final thermal load working times than the fuel cell of the stop time required amount earliest time of the time zone heat load model pattern,
This is a fuel cell cogeneration system.
[0007]
According to the above-described invention, the operating rate of the fuel cell is increased (maximum power generation capacity) under conditions where the hot water supply load is maximized, such as in winter, and the hot water supply is prevented by operating regardless of the power demand. It can be used comfortably.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention is
A power load detecting means for detecting a power load;
A fuel cell having a battery stack that generates electricity by electrochemically reacting hydrogen and oxygen; and
A hot water storage tank of a circulating stacked boiling type that stores hot water heated by the exhaust heat of the fuel cell;
A water supply channel for connecting to the lower part of the hot water storage tank and supplying city water,
A hot water storage path for circulating water in the hot water storage tank connected to the lower and upper portions of the hot water storage tank ;
A heat exchanger for transferring waste heat of the fuel cell to water in the hot water storage path;
A hot water supply path connected to the upper part of the hot water storage tank;
A hot water storage tank upper temperature detector provided in the upper part of the hot water storage tank;
A hot water storage tank lower temperature detector provided at the lower part of the hot water storage tank;
A water amount detector provided in the middle of the hot water supply path;
Thermal load detection means for detecting a thermal load from the hot water storage tank upper temperature detector and the water amount detector;
A storage unit that stores a power load for each time zone and a heat load for each time zone in a certain period over a plurality of days based on the detected information on the power load and the heat load,
A power load prediction unit and a thermal load prediction unit that average the measurement results in the predetermined period and determine the power load for each time zone and the thermal load model pattern for each time zone and store them in the storage unit,
At the beginning of operation, the operation rate of the fuel cell is controlled corresponding to the power load, and the fuel cell is operated once / day (hereinafter referred to as on / off once control), and the predetermined period of time. When the fuel cell is operated at the operating rate near the upper limit of the rated capacity for one day according to the predicted heat load model pattern for each time zone after the elapse of time, the fuel When exceeding the amount of heat generated by exhaust heat recovery calculated from the amount of power generated by the battery, when the fuel cell is operated at a constant operating rate near the upper limit of the rated capacity for one day continuously after stopping the on / off control once and below, Performs on / off control once and operates the fuel cell at a constant operating rate calculated from the amount of heat load required for one day, and the operation start time is fuel from the heat load use time of the time-dependent heat load model pattern. When the battery startup time is early Determined, the shutdown time control means adapted to determine the final thermal load working times than the fuel cell of the stop time required amount earliest time of the time zone heat load model pattern,
This is a fuel cell cogeneration system.
[0009]
Therefore, the daily hot water consumption (heat load amount) is calculated from the amount of power generated by the fuel cell when the fuel cell is operated at an operating rate before the upper limit of the rated capacity for one consecutive day. If above the hot water hot water storage amount (heat) by exhaust heat recovery, since hot water is predicted to be operating time of insufficient fuel cell chronic prolonged hot water consumption (heat load) and hot water hot water storage amount (heat) is The fuel cell is operated continuously for one day by setting a constant operating rate near the upper limit of the rated capacity of the fuel cell to be equal. As a result, hot water can be used comfortably with little hot water shortage.
[0010]
Normally, on / off control is performed once, but under conditions where the hot water supply load is large, such as in winter, the number of fuel cell startups can be reduced by stopping the on / off control once and performing continuous operation throughout the day. Further, it is possible to improve the durability of the fuel cell by preventing the start-up energy loss of the fuel cell and reducing the intermittent operation that affects the deterioration of the fuel cell. Further, the daily hot water consumption (heat load amount) is calculated from the power generation amount of the fuel cell when the fuel cell is operated at the operating rate before the upper limit of the rated capacity for one day continuously. When the amount of stored hot water is less than the amount of stored hot water ( heat amount ), the fuel cell is operated at a constant operating rate calculated from the heat load required per day by controlling on / off once. Since the time required for starting the fuel cell is determined to be earlier than the heat load use time of the different heat load model pattern, and the operation stop time is determined to be earlier than the final heat load use time by the time required for stopping the fuel cell. The hot water can be used comfortably without running out of hot water from the hot water use start time to the hot water use end time.
[0011]
In addition, rather than operating the fuel cell every time with hot water consumption (thermal load) by time of day, a constant operating rate calculated based on the total hot water consumption (thermal load) per day Since the operation method of the day is determined, the setting of the on / off once control is simplified and the control can be easily performed.
[0012]
In the fuel cell cogeneration system according to claim 1, the surplus power is converted into heat by the electrothermal conversion means in the fuel cell cogeneration system according to claim 1 when the response to the thermal load is controlled with the highest priority. , Surplus power that may be generated when the fuel cell is operated with priority over the heat load can be converted into heat and used for hot water supply, giving priority to the response to the heat load, and eliminating fuel waste, Energy saving can be achieved.
[0013]
According to a third aspect of the present invention, in the fuel cell cogeneration system according to the first or second aspect, even if the fuel cell is operated at an operating rate at the upper limit of the rated capacity for several days, the power generation of the fuel cell is performed. When the amount of heat per day by exhaust heat recovery calculated from the amount is less than the amount of heat load per day predicted by the heat load model pattern by time zone, the operation is stopped or a warning is issued by the remote control Is. Then, the case where a few days, the fuel cell is less than the hot water hot water storage amount running at maximum heat load output (power generation capacity up to) (quantity of heat) hot water consumption is predicted (thermal load), When the capacity of the installed fuel cell cogeneration system does not meet the usage conditions (warm water consumption (heat load)) in the user's home, and the hot water has run down due to forgetting to close the hot water tap etc. Therefore, the operation of the fuel cell is stopped or a warning is issued by the remote controller. As a result, the user can be informed of an abnormality such as information indicating that the installed fuel cell cogeneration system has insufficient capacity and forgetting to close the hot water supply, and the operation can be stopped.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
(Example 1)
FIG. 1 is a configuration diagram of a fuel cell cogeneration system according to a first embodiment of the present invention, and FIG. 2 shows an electric power load / hot water consumption pattern in a user's home and a corresponding operation rate / exhaust heat recovery pattern of fuel cell operation. .
[0016]
In FIG. 1, reference numeral 1 denotes a fuel cell, which includes a hydrogen generator 2 and a battery stack 3. The hydrogen generator 2 reforms a fuel such as city gas into hydrogen and supplies it to the battery stack 3. The battery stack 3 generates electricity by electrochemically reacting with hydrogen and oxygen in the atmosphere supplied by a blower or the like. Generated electricity is boosted AC inverter 4 so about DC 50 V, is supplied to the power load of the appliance, such as in the home via the AC200V next power load detecting means 5. An exhaust heat recovery path 6 is connected between the fuel cell 1 and the heat exchanger 7 by a cooling water path 9 having a cooling water circulation pump 8, and between the heat exchanger 7 and the hot water storage tank 10 is a hot water storage circulation pump. 11 are connected by a hot water storage path 12 having 11. A hot water supply path 13 is connected to the lower part of the hot water storage tank 10, a hot water supply path 14 is connected to the upper part of the hot water storage tank 10, a water amount detector 15 is located in the middle of the hot water supply path 14, and a hot water tap 16 (hot water supply load) is connected to the end. Is provided. A hot water tank upper temperature detector 17 is provided at the upper part of the hot water tank 10, and a hot water tank lower temperature detector 18 is provided at the lower part. The thermal load detection means 19 detects the thermal load used in the hot water tap 16, the data is taken into the hot water consumption prediction means 20, and the power load detection means 5 detects the power load in the user's home. It is taken in by the power load prediction means 21 and input to the control means 22. Reference numeral 23 denotes a heater. Reference numeral 24 denotes a remote controller.
[0017]
Next, general operations and actions will be described. Electricity generated by the fuel cell 1 is supplied to electric appliances in the home by controlling the amount of electric power generated according to the electric power load detected by the electric power load detecting means 5. The heat generated at this time is transmitted to the heat exchanger 7 by circulation of water in the cooling water path 9 by the cooling water circulation pump 8, and further transmitted to the hot water storage tank 10 by circulation of water in the hot water storage path 12 by the hot water storage circulation pump 11. It is done. The hot water storage tank 10 is always filled with water, and when the water drawn into the heat exchanger 7 from the lower part of the hot water storage tank 10 is heated and returned to the upper part of the hot water storage tank 10, hot hot water is layered in order from the upper part of the hot water storage tank 10. The so-called laminated boiling is stored. When the hot water stored in the hot water storage tank 10 is used by the hot water tap 16, water is replenished from the water supply path 13 into the hot water storage tank 10 and the hot water layer is pushed up. Since there is hot water, a high hot water supply temperature can be secured even if the entire hot water storage tank 10 is not boiled.
[0018]
The thermal load detection means 19 can measure the temperature and instantaneous flow rate of the hot water consumed by the hot water storage tank upper temperature detector 17 and the water amount detector 15 , and can detect the thermal load. There is no need to provide means for detecting the thermal load.
[0019]
Next, a control method will be described. FIGS. 2A and 2B show the power load and heat load (hot water consumption) in the user's home for each time zone, for example, continuously detected for one week, and the power load prediction means 21 and the hot water consumption prediction. By storing and averaging in the storage unit of the means 20, the power load model pattern for each time zone and the hot water consumption model pattern for each time zone are predicted. Each model pattern is also stored in the storage unit. In addition, even when a power failure occurs, the storage unit is configured by a non-volatile memory so that no data is lost due to a power failure or the like. Therefore, even after the power failure is restored, the operation can be resumed without predicting each model pattern from the beginning. The fuel cell is operated corresponding to each model pattern, and the operation rate for each time zone is shown in FIG. 2C, and the amount of hot water recovered by exhaust heat from the operation is shown in FIG. ). In the actual fuel cell operation rate control, the operation rate is controlled with priority on the power load, and the operation rate is taken into account in consideration of the hot water consumption in the time zone of the maximum hot water consumption such as evening. The operation of the fuel cell is basically once a day, and in FIG. 2 (c), it starts at 5:00 and stops at 23:00. The start time of the fuel cell (from 6:00 using electricity / hot water) 1 hour) is added and start is started 1 hour earlier, and stop is subtracting the fuel cell stop time (0.5 hours) from 23:30 when electricity and hot water are used to 23:00 . Since the durability of ON / OFF operation is worse than continuous operation as a characteristic of the fuel cell, it is ideal to operate continuously at the rated rate as much as possible, and the most basic daily life pattern of the user. A period of one day is selected as the cycle. In addition, preheating of the hydrogen generator and battery stack is necessary at startup, which causes energy loss and takes about 1 hour from the start of operation until power generation operation is performed, and at the time of shutdown, hydrogen in the hydrogen generator, battery stack and piping is removed. Since power generation continues until it is completely consumed, the operation is stopped about 0.5 hours before the time when electricity is used.
[0020]
As described above, when the fuel cell is operated, the predicted hot water consumption A (shaded portion) on the next day at 24:00 is the hot water storage amount B (hatched portion) by the exhaust heat recovery of the fuel cell. Part)), the control giving priority to the electric power load is stopped, and the control to the heat load is given the highest priority.
[0021]
FIG. 3 shows an example of the operation mode in which the highest priority is given to the response to the heat load. FIG. 3 (a) shows the operating rate by time zone, and FIG. 3 (b) shows the hot water storage amount C (shaded portion) by exhaust heat recovery. Here, A <C is satisfied. In this example, the operating rate of the fuel cell is constant. Considering the total heat load of the day, the operating rate is not set for each time zone corresponding to the heat load, but the total heat of the day. The load is moved at the same operation rate from the start time to the stop time. Since the operation is performed at a constant operation rate, the durability of the fuel cell can be improved. Depending on the time of day, surplus power is generated, but the battery is charged with a storage battery, the power is sold to an electric power company, or converted into heat by the heater 23 disposed in the hot water storage tank 10 to be stored in the hot water storage tank 10. You may supply to water. Of course, when the power is insufficient, it is satisfied from the commercial power source.
[0022]
Thus, by controlling comfort for hot water demand first and considering power demand secondarily, it is possible to prevent hot water shortage and prepare the hot water consumption of the user's home for one day. It is possible to prevent a hot water supply system that is extremely inconvenient to use, such as running out of hot water while using hot water supply and bathing in the middle of the shower. In particular, this control method can be effective under conditions where the hot water supply load is maximized, such as in winter. In addition, it is not necessary to install an auxiliary heating device such as a boiler that must be provided separately when the amount of livestock heat in the hot water storage tank is insufficient, and the equipment cost of the user can be reduced. Further, by using the power generated by the fuel cell without waste, the energy saving performance of the system can be improved, and the durability of the fuel cell can be improved.
[0023]
(Example 2)
4 and 5 show the operation conditions and actual operation modes of another embodiment of the operation mode in which the highest priority is given to the response to the heat load. FIG. 4 shows operating conditions, FIG. 4 (a) shows a case where the operation rate is 80% continuously for one day, and FIG. 4 (b) shows a hot water storage amount D by exhaust heat recovery at an operation rate of 80%. (Shaded area) is shown. FIG. 5 shows an actual operation mode. FIG. 5 (a) shows the operation rate for each time zone, and FIG. 5 (b) shows the hot water storage amount E (shaded part) by exhaust heat recovery.
[0024]
The second embodiment is different from the first embodiment in the control method, the configuration is the same, and the description is omitted. When the hot water consumption A shown in FIG. 2B exceeds the hot water storage amount D in the exhaust heat recovery when the fuel cell is operated at an operation rate of 80% continuously for one day, or surplus power is converted into heat by the heater 23. If the hot water storage amount D converted and added to the exhaust heat recovery is exceeded, it is considered that the hot water production capacity by the fuel cell is close to the upper limit (80 to 100%). The operating rate corresponding to the hot water consumption A is set. Although one on / off control is possible, the stop time is short and the preheating energy loss of the hydrogen generator and the battery stack and the deterioration of the hydrogen generator and the battery stack, which are disadvantages of the on / off operation, can be prevented. Further, since the surplus power is used for hot water supply, there is no waste of energy.
[0025]
A specific example will be described. In the case of winter, the standard hot water consumption (heat load) for a standard family structure (two adults and two children) requires a hot water storage tank of 350 liters with an incoming water temperature of 5 ° C and a boiling temperature of 70 ° C. The heat load is (70−5) × 350 = 2227 kcal (= 26.5 kw). On the other hand, the standard rating of a household fuel cell is a power generation capacity of 1 kw / h, and the exhaust heat recovery heat quantity is 1.2 kw / h. When the control method of the present embodiment is applied to this condition, 80% of the exhaust heat recovery amount from the fuel cell per day is 1.2 × 24 × 0.8 = 23 kW, and the daily heat load 26. Less than 5kw. Therefore, on this condition, the on / off control is stopped once and continuous operation is performed for one day. The operation rate is set to 26.5 ÷ 24 ÷ 1.2 = 0.92 (92%), thereby operating continuously for one day (A = E).
[0026]
In addition, in the case of controlling on / off once, in order to be able to prepare a heat load of 26.5 kw at an operation rate of 100%, 26.5 ÷ 1.2 = 22 h, for example, starting at 2:00 and at 24:00 Will stop.
[0027]
In this embodiment, the operating rate is set to 80% as the operating condition, but it is set to an optimum value depending on the season and other conditions.
[0028]
Therefore, if the control of the present embodiment is performed, the fuel cell can be operated continuously at a high operation rate of 80 to 100% for one day, and the preheat loss of the hydrogen generator and the battery stack compared to the one-on-off control. In addition, energy can be saved without being generated, and deterioration due to on / off of the hydrogen generator and the battery stack can be prevented and durability can be enhanced. In addition, instead of operating the fuel cell each time with hot water consumption by time zone, the daily operation method is determined based on the total hot water consumption per day, so the on / off once control setting is simple. And easy control. And even under conditions where the hot water supply load is maximized as in winter, hot water can be used comfortably without running out of hot water, and there is no need to install an auxiliary heat source such as a water heater.
[0029]
Depending on the time of day, surplus power is generated, but the battery is charged with a storage battery, the power is sold to an electric power company, or converted into heat by the heater 23 disposed in the hot water storage tank 10 to be stored in the hot water storage tank 10. You may supply to water. When surplus power is supplied to the water in the hot water storage tank, the operating rate may be lowered in consideration of this amount of heat. Of course, when the power is insufficient, it is satisfied from the commercial power source.
[0030]
In addition, when the hot water consumption A shown in FIG. 2B is lower than the hot water storage amount D in the exhaust heat recovery when the fuel cell is operated at an operation rate of 80% continuously for one day, or surplus power is supplied by the heater 23. When it is below the hot water storage amount D converted into heat and added to the exhaust heat recovery, the same control as in the first embodiment is performed.
[0031]
(Example 3)
The third embodiment is different from the second embodiment in the control method, the configuration is the same, and the description is omitted. In Example 2, when the hot water consumption A shown in FIG. 2 (b) exceeds the hot water storage amount D in the exhaust heat recovery when the fuel cell is operated at an operation rate of 80% continuously for one day, or the surplus power is When the amount of hot water stored in the heater 23 exceeds the hot water storage amount D, which is added to the exhaust heat recovery, it is considered that the hot water production capacity of the fuel cell is close to the upper limit (80 to 100%). The operation rate corresponding to the hot water consumption A is set for one day, but even if the operation rate is 100%, the hot water storage amount will meet the predicted hot water consumption. If there is no case for 3 days, the operation of the fuel cell is stopped or a warning is issued by the remote controller 24. This is when the capacity of the installed fuel cell cogeneration system does not meet the usage conditions (warm water consumption) in the user's home, and when hot water is flowing down due to forgetting to close the hot water tap etc. Inform the user that the installed fuel cell cogeneration system has insufficient capacity, replace it with one with a higher rated output, or install an auxiliary heat source such as a water heater. And user convenience of hot water supply can be improved. In addition, it is possible to prevent the user from consuming wasteful energy by notifying the user of an abnormality such as forgetting to close the hot-water tap and stopping the operation.
[0032]
【The invention's effect】
As described above, according to the present invention, when it is determined that the predicted hot water consumption (heat load amount) is larger than the hot water storage amount ( heat amount ) due to the recovery of exhaust heat from the fuel cell, the response to the heat load is the best. Because priority is given to control, the operating rate of the fuel cell is increased (high power generation capacity) under conditions where the hot water supply load is maximized, such as in winter, and the hot water is prevented from running out and the hot water supply is used comfortably. be able to.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a fuel cell cogeneration system according to a first embodiment of the present invention. FIG. 2 is a diagram showing an electric power load pattern in a household using the system. FIG. (C) Diagram showing fuel cell operation rate pattern of the system (d) Diagram showing warm water amount ( heat amount ) pattern by exhaust heat recovery of the system [FIG. 3] (a) Fig. 4 shows the fuel cell operation rate pattern that gives top priority to the system's thermal load. Fig. 4 (b) shows the hot water volume ( heat amount ) pattern by exhaust heat recovery that gives the top priority to the system's thermal load. indicating the amount of hot water (heat) pattern by (a) a waste heat recovery in FIG (b) the system of a fuel cell operating rate pattern of the fuel cell cogeneration system according to a second embodiment of the present invention 5 (a) Fig. [Description of symbols] indicating the amount of hot water (heat) pattern by heat recovery in FIG (b) the system of a fuel cell operating rate pattern of the system
DESCRIPTION OF SYMBOLS 1 Fuel cell 5 Electric power load detection means 10 Hot water storage tank 12 Hot water storage path (Fuel cell going-out circuit, fuel cell return circuit)
15 water detector 17 hot water storage tank upper temperature detector 19 heat load detecting means 20 hot water consumption prediction means 21 load forecasting means 22 control means 23 a heater (electrothermal converter)
24 remote control

Claims (3)

A power load detecting means for detecting a power load;
A fuel cell having a battery stack that generates electricity by electrochemically reacting hydrogen and oxygen; and
A hot water storage tank of a circulating stacked boiling type that stores hot water heated by the exhaust heat of the fuel cell;
A water supply channel for connecting to the lower part of the hot water storage tank and supplying city water,
A hot water storage path for circulating water in the hot water storage tank connected to the lower and upper portions of the hot water storage tank ;
A heat exchanger for transferring waste heat of the fuel cell to water in the hot water storage path;
A hot water supply path connected to the upper part of the hot water storage tank;
A hot water storage tank upper temperature detector provided in the upper part of the hot water storage tank;
A hot water storage tank lower temperature detector provided at the lower part of the hot water storage tank;
A water amount detector provided in the middle of the hot water supply path;
Thermal load detection means for detecting a thermal load from the hot water storage tank upper temperature detector and the water amount detector;
A storage unit that stores a power load for each time zone and a heat load for each time zone in a certain period over a plurality of days based on the detected information on the power load and the heat load,
A power load predicting means and a thermal load predicting means for averaging the measurement results in the predetermined period and determining a power load for each time zone and a heat load model pattern for each time zone and storing them in a storage unit
At the beginning of operation, the operation rate of the fuel cell is controlled corresponding to the power load, and the fuel cell is operated once / day (hereinafter referred to as on / off once control), and the predetermined period of time. When the fuel cell is operated at the operating rate near the upper limit of the rated capacity for one day according to the predicted heat load model pattern for each time zone after the elapse of time, the fuel When exceeding the amount of heat generated by exhaust heat recovery calculated from the amount of power generated by the battery, when the fuel cell is operated at a constant operating rate near the upper limit of the rated capacity for one day continuously after stopping the on / off control once and below, Performs on / off control once and operates the fuel cell at a constant operating rate calculated from the amount of heat load required for one day, and the operation start time is fuel from the heat load use time of the time-dependent heat load model pattern. When the battery startup time is early Determined, the shutdown time control means adapted to determine the final thermal load working times than the fuel cell of the stop time required amount earliest time of the time zone heat load model pattern,
A fuel cell cogeneration system.   The fuel cell cogeneration system according to claim 1, wherein surplus power is converted into heat by electrothermal conversion means installed in a hot water storage tank.   For several days, even if the fuel cell is operated at the maximum operating capacity of the rated capacity, the amount of heat generated by exhaust heat recovery calculated from the amount of power generated by the fuel cell is predicted from the heat load model pattern for each time zone1 3. The fuel cell cogeneration system according to claim 1, wherein the operation is stopped or a warning is issued by a remote controller when the amount of heat load of the day is not reached. 4.

Images