JP2011185520A - Cogeneration system - Google Patents

Abstract

Provided is a cogeneration system capable of operating a combined heat and power supply device so as to suppress excess and deficiency of heat even when heat is recovered from a heat medium in a heat medium circulation path to hot water in a hot water tank.
SOLUTION: A heat medium heating circulation means U2, a heat recovery means U3, and a recovered heat quantity acquisition means 43 are provided, and the operation control means 5 is based on the acquired information of the recovered heat quantity measurement means 43, and the heat recovery means U3. The time-series actual recovery heat quantity data that can be recovered by the management is managed, and the time-series prediction that is predicted to be recovered by the heat recovery means U3 based on the managed time-series actual recovery heat quantity data Recovered heat quantity data is configured to be obtained by dividing every operation cycle, and based on time-series predicted recovered heat quantity data in addition to time-series predicted load power data and time-series predicted load heat quantity data Thus, the driving conditions are set so as to increase driving merit.
[Selection] Figure 1

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 by heat generated by the combined heat and power supply device, and operation control means for controlling operation,
The operation control means manages the time-series predicted load power data and the time-series predicted load calorie data separately for each operation cycle, and at the start of the operation cycle, the time-series predicted load The present invention relates to a cogeneration system configured to determine the operation condition of the combined heat and power supply device in the operation cycle based on electric power data and the time-series predicted load heat quantity data so that the operation merit is increased.

  Such a cogeneration system is installed in, for example, a general household, consumes the generated power of the combined heat and power device in an electric device, etc., stores hot water in the hot water storage tank with heat generated from the combined heat and power supply apparatus, and the hot water storage tank The hot water stored in the hot water is consumed in the kitchen or bath. Incidentally, the combined heat and power device is composed of a fuel cell, an engine-driven generator, and the like.

In such a cogeneration system, time-series predicted load power data and time-series predicted load calorie data are managed separately for each operation cycle, and the time-series predicted load power at the start of the operation cycle. Based on the data and time-series predicted load calorie data, the operation condition of the combined heat and power device is determined in the operation cycle so that the operation merit is high, and the combined heat and power device is operated under the determined operation condition. (For example, refer to Patent Document 1).
As the operating conditions of the combined heat and power device, for example, the operating time zone of the combined heat and power device during the operation cycle and the output power of the combined heat and power device are determined.
By the way, as the operation time zone, for example, when it is assumed that the output power of the cogeneration device is adjusted to the main output that follows the predicted load power data, the main output and the cogeneration device are operated at the main output. Thus, a time period during which the operation merit obtained based on the amount of heat generated, time-series predicted load power data, and time-series predicted load heat data is high is determined.

JP 2006-127867 A

By the way, the heat medium heating circulation means for circulating the heat medium for supplying heat through the heat medium circulation path passing through the heat consumption part and supplying the heat consumption part, and the heat of the heat medium circulation path There may be provided a heat recovery means capable of recovering heat from the medium to the hot water in the hot water tank.
Specific examples of the heat consuming unit include a bathtub, a floor heating device, a bathroom heating drying device, and the like. And when the bathtub as a heat consumption part is applied, the heat medium of a heat-medium circulation path is the hot water of a bathtub, and heat | fever is collect | recovered from the hot water of a bathtub to the hot water of a hot water tank.
However, in the conventional cogeneration system, when heat is recovered from the heat medium in the heat medium circulation path to the hot water in the hot water tank, the operation merit is based on the time-series predicted load power data and the time-series predicted load heat quantity data. When the combined heat and power unit is operated under operating conditions determined to be high, the amount of heat in the hot water storage tank is greater than the amount of load heat covered by the heat stored in the hot water storage tank (hereinafter sometimes referred to as hot water supply load heat amount). It was easy to generate excess heat.
In other words, the conventional cogeneration system is based on storing heat in the hot water in the hot water tank, but for example, when the hot water remains in the bathtub, the heat medium circulation path via the heat consuming part is used. When the heat medium has available heat, the operating conditions of the combined heat and power unit are not defined from the viewpoint of using the retained heat, and as a result, there is room for improvement in terms of effective use of heat. was there.

  The present invention has been made in view of such circumstances, and its purpose is to provide both heat and electricity so as to suppress excessive and insufficient heat even when heat is recovered from the heat medium in the heat medium circulation path to the hot water in the hot water tank. The object is to provide a cogeneration system capable of operating an apparatus.

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. Provided, and the operation control means divides and manages time-series predicted load power data and time-series predicted load heat quantity data for each operation cycle, and at the start of the operation cycle, On the basis of the predicted load power data and the time-series predicted load calorie data, the operation condition of the combined heat and power device in the operation cycle is determined so as to increase the operation merit,
The first characteristic configuration is a heating medium heating and circulating means capable of supplying heat to the heat consuming part by circulating a heat medium for supplying heat through a heat medium circulation path passing through the heat consuming part, Heat is exchanged between the heat medium in the heat medium circulation path and the hot water in the hot water tank or water supplied to the hot water tank from the outside, and heat is recovered from the heat medium in the heat medium circulation path to the hot water in the hot water tank. A heat recovery means capable of recovering, and a heat quantity that can be recovered by the heat recovery means or a heat recovery quantity acquisition means for acquiring heat quantity related information for obtaining the heat quantity,
The operation control means is
Based on the acquired information of the recovered heat quantity acquisition means, manages the time-series actual recovered heat quantity data that can be recovered by the heat recovery means, and based on the managed time-series actual recovered heat quantity data It is configured to obtain the time-series predicted recovered heat quantity data predicted to be recovered by the heat recovery means, divided for each operation cycle, and
In addition to the time-series predicted load power data and the time-series predicted load calorie data, the operating conditions are determined based on the time-series predicted recovered heat amount data so that the operation merit is increased. It is in the point which is comprised.

According to the above characteristic configuration, when the heat recovery means operates, heat is recovered from the heat medium in the heat medium circulation path to the hot water in the hot water tank. Further, the amount of heat that can be recovered by the heat recovery means or the amount-of-heat related information for obtaining the amount of heat is acquired by the recovered heat amount acquisition means.
The operation control means manages the time-series actual recovered heat quantity data that can be recovered by the heat recovery means based on the acquired information of the recovered heat quantity acquisition means, and converts it into the time-series actual recovered heat quantity data that is managed. Based on this, time-series predicted heat recovery data is obtained by dividing each operation cycle.
And the operation control means is a combined heat and power unit so that the operation merit is increased based on the time-series predicted recovered heat quantity data in addition to the time-series predicted load power data and the time-series predicted load heat quantity data. Define the operating conditions.

In other words, based on the past time-series actual recovered heat quantity data being managed, how much heat is transferred from the heat medium in the heat medium circulation path to the hot water storage tank at what time zone of the target operation cycle for which the operating conditions are determined. Whether it can be recovered in hot water can be predicted.
In the time zone in which the amount of hot water in the hot water tank is expected to be recovered from the heat medium in the heat medium circulation path, the amount of heat stored in the hot water tank is the amount recovered from the heat medium in the heat medium circulation path. Since the operating conditions of the combined heat and power supply device in the operation cycle are determined so that the operating merit is increased, the operating conditions can be determined so as to store heat in the hot water storage tank so as to suppress excess and deficiency with respect to the hot water supply load heat amount. it can.
Therefore, even when heat is recovered from the heat medium in the heat medium circulation path to the hot water in the hot water storage tank, it is possible to provide a cogeneration system that can operate the combined heat and power supply device so as to suppress excessive or insufficient heat. It was.

In addition to the first feature configuration, the second feature configuration is
Heat consumption end input means for inputting heat consumption end information indicating that the heat consumption in the heat consumption unit has ended by human operation is provided,
The operation control means is configured to operate the heat recovery means when the heat consumption end information is input by the heat consumption end input means.

According to the above characteristic configuration, when the user inputs the heat consumption end information by the heat consumption end input means, the heat recovery means automatically operates, and the amount of heat is transferred from the heat medium in the heat medium circulation path to the hot water in the hot water tank. Collected.
That is, it is preferable to recover the heat from the heat medium circulation path by the heat recovery means after the heat consumption in the heat consumption unit is completed.
On the other hand, for example, when an example of the heat consuming unit is a bathtub, the timing at which the use of the bathtub ends, that is, the timing at which the heat consumption in the heat consuming unit ends is determined by the user's intention.
Therefore, by adopting a configuration such as this characteristic configuration, for example, when the end of heat consumption in the heat consuming unit is determined by the user's intention, such as the end of bathing, the heat consumption in the heat consuming unit is accurately terminated. After that, the heat recovery means can be operated to recover the amount of heat from the heat medium in the heat medium circulation path to the hot water in the hot water tank.

The third feature configuration is in addition to the second feature configuration,
The operation control means has a temperature relationship between the heat medium in the heat medium circulation path exchanged in the heat recovery means and hot water in the hot water storage tank or water supplied to the hot water storage tank from the outside. The heat recovery means is configured to operate under conditions where the temperature of the heat medium in the circulation path is higher.

According to the above characteristic configuration, the temperature relationship between the heat medium in the heat medium circulation path exchanged in the recovery means and the hot water in the hot water storage tank or the water supplied from the outside to the hot water storage tank is determined by the heat medium in the heat medium circulation path. The heat recovery means is activated only when the temperature is higher and the amount of heat from the heat medium in the heat medium circulation path to the hot water in the hot water tank can be recovered.
Therefore, as much heat as possible from the heat medium in the heat medium circulation path can be accurately recovered in the hot water in the hot water tank.

In addition to the third feature configuration, the fourth feature configuration is
Freezing prevention means for preventing freezing of the heating medium in the heating medium circulation path is provided,
The operation control means is
When the temperature of the heat medium in the heat medium circulation path is equal to or lower than the processing start set temperature, the freeze prevention means is configured to be operated, and
When the heat recovery means is in operation, the heat recovery means is stopped when the temperature of the heat medium in the heat medium circulation path becomes equal to or lower than the process avoidance set temperature range than the process start set temperature. It is in the point comprised as follows.

According to the above characteristic configuration, when the temperature of the heat medium in the heat medium circulation path becomes equal to or lower than the processing start set temperature, the freeze prevention means operates, so that the heat medium in the heat medium circulation path is prevented from freezing.
Incidentally, the processing start set temperature is set to a temperature slightly higher than the temperature at which the heat medium in the heat medium circulation path may freeze, for example.
Then, when the heat recovery means is operating, the heat recovery means is stopped when the temperature of the heat medium in the heat medium circulation path becomes equal to or lower than the process avoidance set temperature range than the process start set temperature. By setting the processing avoidance set temperature range appropriately, even if the temperature of the heat medium in the heat medium circulation path drops after the heat recovery means stops, it should not become lower than the set temperature for process start. Is possible.
Therefore, even when the amount of heat is recovered from the heat medium in the heat medium circulation path to the hot water in the hot water tank when the temperature is low enough that the heat medium in the heat medium circulation path may freeze, the heat medium in the heat medium circulation path It is possible to prevent wasteful energy from being consumed by preventing the freeze prevention means from operating while preventing freezing.

In addition to any one of the first to fourth feature configurations described above, the fifth feature configuration is
The heat medium heating circulation means is configured to circulate through the heat medium circulation path using hot water in the bathtub as the heat consuming part as a heat medium.

According to the above characteristic configuration, the heat medium heating and circulating means is configured to circulate the hot water in the bathtub as the heat consuming part through the heat medium circulation path as the heat medium, so that the hot water in the bathtub is recovered by the heat recovery means. The amount of heat is collected in the hot water in the hot water tank.
That is, since a large amount of hot water is stored in the bathtub and a large amount of heat is stored by the hot water, a large amount of heat can be recovered in the hot water in the hot water tank.
Therefore, it is possible to reduce the energy consumed for the operation of the combined heat and power supply apparatus while sufficiently covering the hot water supply load heat amount, and the energy saving can be further improved.

In addition to any one of the first to fourth feature configurations described above, the sixth feature configuration is
The heat medium heating circulation means is configured to circulate the heat medium through the heat medium circulation path via a heat consumption terminal as the heat consumption unit.

According to the above characteristic configuration, the heat recovery means recovers heat from the heat medium in the heat medium circulation path via the heat consuming terminal to the hot water in the hot water storage tank.
That is, examples of the heat consuming terminal include a heating medium circulation heating device such as a floor heating device and a bathroom heating / drying device.
And after stopping operation | movement of such a heat-medium circulation type heating apparatus, the calorie | heat amount remaining in the heat medium of a heat-medium circulation path | route can be collect | recovered in the hot water of a hot water storage tank.

In addition to any one of the first to sixth feature configurations described above, the seventh feature configuration is
The recovered heat quantity acquisition means is constituted by a recovered heat quantity measuring means for measuring heat quantity recovered by the heat recovery means or heat quantity related information for obtaining the heat quantity.

According to the above characteristic configuration, the heat quantity actually measured by the heat recovery means or the heat quantity related information for obtaining the heat quantity is measured by the recovered heat quantity measurement means.
The operation control means manages the time-series actual recovered heat quantity data actually recovered by the heat recovery means based on the measurement information of the recovered heat quantity measuring means, and manages the time-series actual Based on the recovered heat data, time-series predicted recovered heat data is determined for each operation cycle.
That is, since the time-series predicted recovered heat quantity data is obtained based on the heat quantity data actually recovered by the heat recovery means, the amount of hot water in the hot water tank is recovered from the heat medium in the heat medium circulation path. The prediction accuracy of the predicted time zone and the amount of recovered heat can be increased.
Therefore, since the operating conditions are determined based on the predicted recovered heat quantity data with high prediction accuracy, the combined heat and power supply apparatus can be operated so as to further suppress the excess and deficiency of heat.

In addition to any one of the first to seventh feature configurations described above, the eighth feature configuration is
The operation control means is a continuous operation mode in which the cogeneration device is operated over the entire time period of the operation cycle, an intermittent operation mode in which the cogeneration device is operated in a part of the operation cycle, and the entire operation cycle. The time-series predicted load power data, the time-series predicted load heat amount data, and the time-series predicted recovered heat amount data from at least two of the standby modes for stopping the heat and power supply device over time. It is the point which is comprised so that the said driving | running condition may be determined by selecting the thing with the driving | operation merit calculated | required based on.

According to the above characteristic configuration, the time-series predicted load power data, the time-series predicted load heat amount data, and the time-series predicted recovery from at least two of the continuous operation mode, the intermittent operation mode, and the standby mode. The thing with the high operation merit calculated | required based on calorie | heat amount data is selected as an operation | movement form of a combined heat and power supply apparatus.
That is, the load power and load heat amount of the operation cycle vary depending on the season and the like.
And since a continuous operation form operates a heat-and-electric power supply apparatus over the whole time slot | zone of an operation cycle, when load electric power and load calorie | heat amount are quite large, an operation merit becomes high, suppressing the excess and deficiency with respect to load calorie | heat amount. Thus, the combined heat and power device can be operated.
The intermittent operation mode operates the combined heat and power supply device in a part of the operation period, so when the load power and the load heat amount are relatively small, the operation merit is high while suppressing excess and deficiency with respect to the load heat amount. Thus, the cogeneration apparatus can be operated.
Furthermore, when the load power and load heat amount are considerably small, it is better to stop the combined heat and power unit and wait for the operation in the entire time period of operation than to operate the combined heat and power unit in the continuous operation mode or intermittent operation mode. The benefits may be higher.
Therefore, by adopting a configuration such as this characteristic configuration, it is possible to operate the combined heat and power supply device so as to increase the operation merit even when the load power and the load heat amount of the operation cycle fluctuate.

Block diagram showing the overall configuration of the cogeneration system Block diagram showing control configuration of cogeneration system Block diagram showing configurations of heating medium heating circulation unit and heat recovery unit The figure explaining the process which calculates | requires prediction energy reduction amount The figure which shows the flowchart of control operation of the cogeneration system The figure which shows the flowchart of control operation of the cogeneration system

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the cogeneration system includes a fuel cell 1 as a cogeneration device that generates electric power and heat, and hot water is stored in a hot water tank 2 by heat generated by the fuel cell 1, It comprises a hot water storage unit U1 as hot water storage means for heating the heat medium circulated and supplied to the consumption terminal 3, and an operation control unit 5 as operation control means for controlling the operation of this cogeneration system.
The cogeneration system further includes a heating medium heating capable of supplying heat to the heat consumption section B by circulating a heat medium for supplying heat through the heat medium circulation path R via the heat consumption section B. Heat is exchanged between the heating medium heating circulation unit U2 as the circulation means and the heating medium in the heating medium circulation path R and the hot water in the hot water tank 2 to heat the hot water in the hot water tank 2 from the heating medium in the heating medium circulation path R. A heat recovery unit U3 as heat recovery means that can be recovered and a freeze prevention means D for preventing the heat medium in the heat medium circulation path R from freezing are provided.

Since the fuel cell 1 is well known, the detailed description and illustration thereof will be omitted. Briefly, the fuel cell 1 includes a cell stack that generates power by being supplied with a fuel gas containing hydrogen and an oxygen-containing gas. A fuel gas generation unit that generates fuel gas to be supplied to the stack, a blower that supplies air as an oxygen-containing gas to the cell stack, and the like are provided.
The fuel gas generation unit is separate from a desulfurizer that desulfurizes hydrocarbon-based raw fuel gas such as city gas (for example, natural gas-based city gas) supplied, and desulfurized raw fuel gas supplied from the desulfurizer. A reformer that generates a reformed gas mainly composed of hydrogen by reforming the supplied steam, and carbon monoxide in the reformed gas supplied from the reformer is converted into carbon dioxide with steam. It is composed of a transformer for transformation treatment, a carbon monoxide remover that selectively oxidizes carbon monoxide in the reformed gas supplied from the transformer with selective oxidation air supplied separately, and transforms carbon monoxide. The reformed gas reduced by the treatment and the selective oxidation treatment is supplied to the cell stack as the fuel gas.

And it is comprised so that the output electric power of the fuel cell 1 may be adjusted by adjusting the supply amount of the raw fuel gas to a fuel gas production | generation part.
As shown in FIG. 1, a grid interconnection inverter 6 is provided on the power output side of the fuel cell 1, and the inverter 6 receives the output power of the fuel cell 1 from a commercial power supply 7. It is comprised so that it may become the same voltage and the same frequency.
The commercial power source 7 is electrically connected to a power load 9 such as a television, a refrigerator, and 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 of the fuel cell 1 is supplied to the power load 9 via the inverter 6 and the generated power supply line 10. It is configured as follows.

The received power supply line 8 is provided with load power measuring means 11 for measuring the load power of the power load 9, and this load power measuring means 11 determines whether or not a reverse flow occurs in the current flowing through the received power supply line 8. Is also configured to detect this.
The electric power supplied from the fuel cell 1 to the received power supply line 8 is controlled by the inverter 6 so that no reverse power flow occurs, and the surplus power of the output 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 that flows through the cooling water circulation path 14 by the operation of the cooling water circulation pump 15, and is connected to the output side of the inverter 6. The ON / OFF switch is individually switched by the actuated switch 13.
The operation switch 13 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.
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 U1 stores the hot water for hot source through the hot water storage tank 2 for storing hot water in a state in which temperature stratification is formed, the hot water circulation pump 17 for circulating hot water in the hot water tank 2 through the hot water circulation path 16, and the heat source circulation path 20. Heat source circulation pump 21 for circulation, terminal heat medium circulation pump 23 for circulating supply of the heat medium to the heat consuming terminal 3 through the terminal heat medium circulation path 22, and heat for hot water storage for heating the hot water flowing through the hot water circulation path 16 Exchanger 24, heat source heat exchanger 25 that heats hot water for heat source flowing through heat source circulation path 20, and heat medium heating heat exchanger 26 that heats the heat medium flowing through terminal heat medium circulation path 22. A hot water source that is taken out from the hot water storage tank 2 and flows through the hot water supply passage 27 and a hot water source for heat source that flows through the heat source circulation passage 20 are provided with a combustion type auxiliary heater 28 and the like.

  The hot water circulation path 16 is connected to the bottom and top of the hot water tank 2 so that hot water taken out from the bottom of the hot water tank 2 is returned to the top of the hot water tank 2 by the hot water circulation pump 17. The hot water is circulated through the hot water circulation path 16, and the hot water circulated through the hot water circulation path 16 is heated by the hot water storage heat exchanger 24, so that hot water is stored in a state where temperature stratification is formed in the hot water tank 2. It is configured as follows.

The hot water supply path 27 is connected to the hot water storage tank 2 through a location downstream of the hot water storage heat exchanger 24 in the hot water circulation path 16, and hot water in the hot water storage tank 2 is connected to the bathtub 33 and the hot water tap 34 through the hot water supply path 27. A hot water supply path 35 is connected to the bottom of the hot water tank 2 so as to supply hot water to the hot water tank 2 as the hot water is supplied.
The heat source circulation path 20 is provided so as to form a circulation path in a state where a part of the hot water supply path 27 is shared, and the heat source circulation path 20 is provided with an intermittent valve for heat source that interrupts the flow of hot water for the heat source. 29 is provided.

The cooling water circulation path 14 is branched into a hot water storage heat exchanger 24 side and a heat source heat exchanger 25 side, and the flow rate of cooling water and heat source heat to be passed to the hot water storage heat exchanger 24 side at the branch point. A diversion valve 30 is provided for adjusting the ratio of the flow rate of the cooling water to be passed to the exchanger 25 side.
The diversion valve 30 allows the entire amount of cooling water in the cooling water circulation path 14 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 14 to flow to the heat source heat exchanger 25 side. It is comprised so that it can also be made.

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 in the cooling water circulation path 14 that has recovered the heat generated by the fuel cell 1. . The heat source heat exchanger 25 is configured to heat the heat source hot water flowing through the heat source circulation path 20 by flowing the cooling water in the cooling water circulation path 14 that has recovered the heat generated by the fuel cell 1. Has been.
In the heat exchanger for heat medium heating 26, the heat medium flowing through the terminal heat medium circulation path 22 by passing hot water for the heat source heated by the heat exchanger for heat source 25 or the auxiliary heater 28 is passed through. Is configured to be heated. Incidentally, a heating terminal such as a floor heating device, a bathroom heating / drying device, or a fan convector is provided as the heat consuming terminal 3.

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

As shown in FIG. 3, a bath circulation path 36 is provided so as to circulate hot water in the bathtub 33 across the bathtub 33 and the auxiliary heater 28.
The bath circulation path 36 includes a return path 36r for returning hot water from the bathtub 33 to the auxiliary heater 28, and a forward path 36f for supplying hot water from the auxiliary heater 28 to the bathtub 33. The return path 36r includes A bath circulation pump 37 for circulating hot water through the bath circulation path 36 is provided.
The hot water supply branch 27 is branched from the hot water supply passage 27, the hot water supply branch 27 d is connected to the return path 36 r of the bath circulation path 36, and the hot water in the hot water tank 2 is supplied to the hot water supply branch 27 d and the bath. It is configured to be supplied to the bathtub 33 through the circulation path 36.
The hot water filling branch 27d is provided with a hot water interrupting valve 38 for interrupting hot water filling to the bathtub 33, a check valve 39 for preventing a reverse flow from the bathtub 33 side, and a vacuum breaker 40.

  The hot water circulation path 16 is provided with a parallel portion that is divided into two channels and then joined again, and a three-way valve 41 is provided at the junction of the parallel portions, and one of the two channels is provided. On the side, a heat recovery heat exchanger 42 for exchanging heat between hot water in the hot water tank 2 taken out from the bottom of the hot water tank 2 and hot water flowing through the return path 36r of the bath circulation path 36 is provided. Yes.

In this embodiment, the bathtub 33 is applied as the heat consuming part B, the bath circulation path 36 is applied as the heating medium circulation path R, and the heating medium heating circulation unit U2 heats the hot water in the bathtub 33 with the auxiliary heater 28. While being circulated through the bath circulation path 36, heat is supplied to the bathtub 33.
The heat recovery unit U3 includes a hot water circulation path 16, a hot water circulation pump 17, a bath circulation path 36, a bath circulation pump 37, a heat recovery heat exchanger 42, and the like.
That is, with the three-way valve 41 switched to a state in which hot water flows through the heat recovery heat exchanger 42 (hereinafter sometimes referred to as a heat exchange state), the hot water circulation pump 17 is operated to store hot water. The hot water in the tank 2 is circulated through the hot water circulation path 16 and the bath circulation pump 37 is operated to circulate the hot water in the bathtub 33 through the bath circulation path 36 so that the hot water tank 2 is stored in the heat recovery heat exchanger 42. Heat is exchanged between the hot water in the bathtub 33 and the hot water in the bathtub 33 to recover heat from the hot water in the bathtub 33 to the hot water in the hot water tank 2.

A recovered heat amount measuring means 43 for measuring heat amount related information for determining the amount of heat recovered by the heat recovery unit U3 is provided.
The recovered heat quantity measuring means 43 is provided on the upstream side of the heat exchanger 42 for heat recovery in the return path 36r and on the downstream side of the heat exchanger 42 for heat recovery in the return path 36r. A post-heat exchange temperature sensor 45 and a bath circulation flow sensor 46 for detecting the flow rate of hot water flowing through the return path 36r are provided.
And the operation control part 5 is based on the detection information of the temperature sensor 44 before heat exchange, the temperature sensor 45 after heat exchange, and the bath circulation flow sensor 46, respectively, and the hot water from the bathtub 33 is stored in the heat exchanger 42 for heat recovery. It is comprised so that the calorie | heat amount collect | recovered by 2 hot water may be calculated | required.
That is, the recovered heat quantity acquisition means for acquiring the heat quantity recoverable by the heat recovery unit U3 or the heat quantity related information for obtaining the heat quantity is constituted by the recovered heat quantity measuring means 43.

A water level sensor 47 for detecting the water level of the bathtub 33 and a water flow switch 48 are provided on the return path 36r.
Furthermore, an electric heater 49 for preventing freezing that prevents freezing of hot water inside the flow path is provided in each of the return path 36r and the forward path 36f.

The auxiliary heater 28 will be described below. As shown in FIG. 3, the auxiliary heater 28 is for hot water supply for heating hot water flowing through the hot water supply path 27 and hot water for heat source flowing through the heat source circulation path 20. A heating unit 28A and a bath heating unit 28B for heating hot water in the bathtub 33 flowing through the bath circulation path 36 are provided, and the operation of the auxiliary heater 28 is controlled by the operation control unit 5.
The hot water supply heating unit 28A and the bath heating unit 28B have the same configuration, a heat exchanger e, a burner b for heating the heat exchanger e, a fan f for supplying combustion air to the burner b, and a heat exchanger. An inflow temperature sensor (not shown) for detecting the inflow temperature of hot water flowing into e, an outflow temperature sensor (not shown) for detecting the outflow temperature of hot water flowing out from the heat exchanger e, and the hot water flowing into the heat exchanger e A flow rate sensor (not shown) for detecting the flow rate is provided.
Incidentally, the heat exchanger e of the hot water supply heating section 28 </ b> A is provided in a shared portion of the hot water supply path 27 with the heat source circulation path 20.

The operation control of the auxiliary heater 28 by the operation control unit 5 will be briefly described.
As shown in FIG. 2, the cogeneration system is provided with a main remote controller 50 and a bath remote controller 51.
The main remote controller 50 is provided with a hot water supply temperature setting unit (not shown) for setting a target hot water supply temperature to be supplied to the hot water tap.
In addition, the bath remote controller 51 indicates that the use of the bathtub 33 has been completed by turning on the hot water filling switch 51a for commanding the hot water filling to the bathtub 33 and the hot water switch 51b for commanding the hot water for the bathtub 33. A bath use end switch 51c for inputting bath use end information, a hot water temperature setting unit 51d for setting a target hot water temperature for the bathtub 33, a water level setting unit 51e for setting a target water level for the bathtub 33, and the like are provided.

The operation control unit 5 burns the burner b when the inflow temperature detected by the inflow temperature sensor becomes lower than a target heating temperature in a state where the flow rate sensor detects a flow rate equal to or higher than a set flow rate, and The combustion amount of the burner b is adjusted so that the outflow temperature detected by the outflow temperature sensor becomes the target heating temperature. When the detected flow rate of the flow sensor becomes less than the set flow rate during the burner b combustion, the burner b is turned off. Extinguish fire.
Incidentally, the target heating temperature corresponding to the hot water supply heating unit 28A is set based on the target hot water supply temperature set by the hot water supply temperature setting unit of the main remote controller 50 when the operation of the heat consuming terminal 3 is stopped. When a hot water filling operation is commanded by the hot water filling switch 51a, the hot water filling temperature is set based on the target hot water filling temperature set by the hot water filling temperature setting unit 51d of the bath remote controller 51, and when the heat consuming terminal 3 is in operation. , Is set to a predetermined temperature set in advance.
The target heating temperature corresponding to the bath heating unit 28B is set based on the target hot water temperature set by the hot water temperature setting unit 51d of the bath remote controller 51.

As shown in FIGS. 1 and 3, the temperature of hot water supplied to the hot water tank 2 by being heated by the hot water heat exchanger 24 at a location downstream of the hot water heat exchanger 24 in the hot water circulation path 16. A hot water storage temperature sensor Sh is provided.
Further, the hot water tank 2 has an upper temperature sensor S1 for detecting the temperature of hot water at the upper end of the hot water tank 2, and an intermediate layer of an equally divided portion obtained by roughly dividing the hot water tank 2 into three equal parts in the vertical direction. An intermediate upper temperature sensor S2 that detects the temperature of hot water at the upper end of the hot water tank, an intermediate lower temperature sensor S3 that detects the temperature of hot water at the lower edge of the middle layer of the hot water tank 2, and the temperature of hot water at the lower end of the hot water tank 2 Is provided, and a water supply temperature sensor Si for detecting a water supply temperature of water supplied to the hot water tank 2 is provided in the water supply channel 35.

A method for calculating the amount of stored hot water in the hot water tank 2 by the operation control unit 5 will be described.
The hot water temperature in the hot water tank 2 detected by the upper end temperature sensor S1, the intermediate upper temperature sensor S2, the intermediate lower temperature sensor S3, and the lower end temperature sensor S4 is T1, T2, T3, and T4, respectively. The water supply temperature detected by Si is Ti, and the capacities of the upper layer portion, the middle layer portion, and the lower layer portion are V (liters).
Also, 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 calorie (kcal) can be calculated by the following equation 1. it can. In this embodiment, the unit of calorie may be indicated by the unit of kcal, but by dividing each value by the coefficient α set to 860 based on the relationship of 1 kWh = 860 kcal, the unit of kWh Can be obtained as

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

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

Next, operation control of the hot water storage unit U1 by the operation control unit 5 will be described.
The operation control unit 5 controls the operation of the fuel cell 1 in a state where the cooling water circulation pump 15 is operated during the operation of the fuel cell 1, and the hot water circulation pump 17, the heat source circulation pump 21, the terminal heat medium. By controlling the operation of the circulation pump 23, the diversion valve 30 and the heat source intermittent valve 29, a hot water storage operation for storing hot water in the hot water storage tank 2 and a heat medium supply operation for supplying a heat medium to the heat consuming terminal 3 are performed. Configured to do.

  The operation control unit 5 performs hot water storage operation when no operation command is issued from the terminal remote controller (not shown) for the heat consuming terminal 3, and in the hot water storage operation, the diverter valve 30 supplies the entire amount of cooling water to the hot water storage heat. The temperature of hot water supplied to the hot water storage tank 2 is preset based on the detection information of the hot water storage temperature sensor Sh in a state where the state is switched to the flow through the exchanger 24 and the heat source intermittent valve 29 is closed. The operation of the hot water circulation pump 17 is controlled so as to adjust the hot water circulation amount so as to reach the target hot water storage temperature (for example, 60 ° C.).

When the operation is instructed from the terminal remote controller, the operation control unit 5 performs a heat medium supply operation. In the heat medium supply operation, the heat source intermittent valve 29 is opened, and the heat source circulation pump 21 is set in advance. The flow dividing valve 30 is configured to control the amount of cooling water corresponding to the terminal load heat amount at the heat consuming terminal 3 to flow through the heat source heat exchanger 25 in a state where the heat consumption terminal 3 is operated at the set rotational speed. In such a state that the heat medium supply operation is performed, when the diverter valve 30 is controlled to flow the cooling water to the hot water storage heat exchanger 24 side, the hot water circulation pump 17 is operated as described above. The hot water storage operation is executed in parallel with the heat medium supply operation.
The operation control unit 5 switches the diverter valve 30 to a state in which the entire amount of the cooling water is allowed to flow to the hot water storage heat exchanger 24 side when an instruction to stop the operation is given from the terminal remote controller during the heat medium supply operation. At the same time, the heat source intermittent valve 29 is closed, the heat source circulation pump 21 is stopped, and the hot water circulation pump 17 is operated to switch from the heat medium supply operation to the hot water storage operation.
The operation control unit 5 sets the three-way valve 41 to the heat exchange state when the bath use end switch 51c of the bath remote controller 51 is turned on and the heat recovery operation described later is executed during the hot water storage operation. When switching and heat recovery operation are not being executed, the three-way valve 41 is switched to a state in which hot and cold water flows around the heat recovery heat exchanger 42 (hereinafter sometimes referred to as a non-heat exchange state). It is configured as follows.

  Then, when hot water in the hot water tank 2 is supplied to the hot water supply destination through the hot water supply passage 27 and during execution of the heat medium supply operation, the operation control unit 5 is supplied to the hot water supply heating unit 28A of the auxiliary heater 28. When the temperature of the hot water is lower than the target heating temperature, the amount of gas fuel supplied to the burner c is adjusted so that the hot water supplied to the hot water supply heating unit 28A is heated to the target heating temperature and discharged. It will be.

Next, operation control of the heat medium heating unit U2 and the heat recovery unit U3 by the operation control unit 5 will be described.
The operation control unit 5 executes a hot water filling operation when the hot water filling switch 51a of the bath remote controller 51 is turned on, performs a hot water driving operation when the hot water switch 51b is turned on, and the bath use end switch 51c is turned on. When turned on, the heat recovery operation for operating the heat recovery unit U3 is executed.
In addition, the operation control unit 5 performs the freeze prevention operation when the temperature detected by the pre-heat exchange temperature sensor 44 is equal to or lower than a preset processing start temperature. Incidentally, the processing start set temperature is set to 5 ° C., for example.

First, a description will be given of the hot water filling operation.
In the filling operation, the operation control unit 5 first opens the filling valve intermittent valve 38, and when the water level detected by the water level sensor 47 reaches the target water level set by the water level setting unit 51e, The intermittent valve 38 is closed.
Subsequently, the bath circulation pump 37 is operated to read the detected temperature of the inflow temperature sensor in the bath heating section 28B of the auxiliary heater 28, and the detected temperature of the inflow temperature sensor is set by the hot water temperature setting section 51d. When the temperature is higher than the target hot water temperature, the bath circulation pump 37 is immediately stopped to end the hot water operation, and when the temperature detected by the inflow temperature sensor is lower than the target hot water temperature, the auxiliary heater 28 is used for the bath. The burner b of the heating unit 28B is burned and the amount of burner b is adjusted as described above. When the detected temperature of the inflow temperature sensor becomes equal to or higher than the target hot water temperature, the bath circulation pump 37 is stopped and the hot water operation is ended. To do.

Next, explanation is added about the memorial operation.
In the memory operation, the operation control unit 5 first operates the bath circulation pump 37, and when the water flow switch 48 is turned on, reads the detected temperature of the inflow temperature sensor in the bath heating unit 28B of the auxiliary heater 28, When the detected temperature of the inflow temperature sensor is equal to or higher than the target hot water temperature set by the hot water temperature setting unit 51d, the bath circulation pump 37 is immediately stopped and the detected temperature of the inflow temperature sensor is lower than the target hot water temperature. When the burner b of the bath heating section 28B of the auxiliary heater 28 is combusted and the amount of combustion of the burner b is adjusted as described above, and the detected temperature of the inflow temperature sensor becomes equal to or higher than the target hot water temperature, the bath circulation pump 37 is stopped and the memorial operation is ended.

Next, a description will be given of the freeze prevention operation.
The operation control unit 5 operates the bath circulation pump 37 to circulate hot water through the bath circulation path 36, thereby preventing the hot water circulation type freezing prevention operation for preventing freezing of the hot water in the bath circulation path 36 and the electric heater 49. By operating and heating the hot water in the bath circuit 36, one of hot water heating type freezing prevention operation for preventing freezing of the hot water in the bath circuit 36 can be selected and executed.
Then, when the temperature detected by the pre-heat exchange temperature sensor 44 is equal to or lower than the processing start set temperature, the operation control unit 5 first operates the bath circulation pump 37, and when the water flow switch 48 is turned on, Therefore, the operation of the bath circulation pump 37 is continued and the hot water circulation type freezing prevention operation is executed. On the other hand, when the water flow switch 48 is not turned on, hot water is accumulated in the bathtub 33. Therefore, the bath circulation pump 37 is immediately stopped and the electric heater 49 is operated to execute a hot water heating type freezing prevention operation.

In addition, when performing the hot water circulation type freezing prevention operation, the operation control unit 5 performs the hot water circulation type freezing prevention operation under the condition that the temperature detected by the temperature sensor 44 before heat exchange is equal to or lower than the processing start set temperature. When the anti-freezing operation of the hot / cold water heating type is executed in the anti-freezing period and the anti-freezing operation of the hot / cold water type is performed, The heating type anti-freezing operation is executed for the anti-freezing set time.
Incidentally, the freeze prevention cycle is set to, for example, 5 minutes, and the freeze prevention set time is set to, for example, 1 minute.
That is, each of the bath circulation pump 37 and the electric heater 49 corresponds to the antifreezing means D for preventing the heat medium in the heat medium circulation path R from freezing.

Next, explanation is added about heat recovery operation.
When the bath use end switch 51c is turned on, the operation control unit 5 performs hot heat exchange in the heat recovery unit U3 (specifically, the heat recovery heat exchanger 42) and hot water and a hot water tank in the bath circulation path 36. 2 is a condition in which the burner b of the bath heating section 28B of the auxiliary heater 28 is not burned under the condition that the temperature of the hot water in the bath circulation path 36 is higher than that of the hot water in the bath 2, that is, the bath heating section 28B. In a state where the heating operation is stopped, the heat recovery unit U3 is operated to perform a heat recovery operation.
Incidentally, the temperature detected by the pre-heat exchange temperature sensor 44 is used as the temperature of the hot water in the bath circuit 36, and the temperature detected by the lower end temperature sensor S4 is used as the temperature of the hot water in the hot water tank 2.
In the heat recovery operation, the operation control unit 5 switches the three-way valve 41 to the heat exchange state and operates the bath circulation pump 37 and the hot water circulation pump 17.

In addition, when the operation control unit 5 operates the heat recovery unit U3, if the temperature of the hot water in the bath circulation path 36 is equal to or lower than the processing start set temperature width higher than the process start set temperature, the heat recovery is performed. The unit U3 is configured to stop.
The set temperature range for avoiding the process is set so as to increase as the time interval increases in accordance with the time interval from the time when the process is executed to a predetermined set time, and is stored in the memory of the operation control unit 5. Has been.
For example, the set time is set to a time at which the temperature is expected to be lowest (for example, 6:00 am). Further, the set temperature range for avoiding the treatment is determined by taking into consideration natural heat radiation from the bath circulation path 36, and the hot water in the bath circulation path 36 is left until the set time without being circulated and heated. Even if the temperature decreases, the temperature is set according to the time interval so as not to decrease to the processing start set temperature.
And the operation control part 5 calculates | requires the setting temperature width for process avoidance corresponding to the time interval from the present time to setting time from the memory | storage information regarding the setting temperature width for process avoidance, and sets the calculated setting temperature width for process avoidance. By adding to the process start set temperature, a process stop set temperature corresponding to the time interval between the current time and the set time is obtained, and whether or not the temperature detected by the temperature sensor 44 before heat exchange is higher than the process stop set temperature. Thus, it is determined whether or not the heat recovery operation can be continued.

  The bath use end information input by the bath use end switch 51c of the bath remote controller 51 corresponds to the heat consumption end information indicating that the heat consumption in the heat consuming unit B has ended, and the bath use end switch 51c is This corresponds to heat consumption end input means for inputting heat consumption end information by human operation.

Next, control of the operation of the fuel cell 1 by the operation control unit 5 will be described.
The operation control unit 5 manages the time-series predicted load power data and the time-series predicted load calorie data separately for each operation cycle, and at the start of the operation cycle, the time-series predicted load Based on the power data and the time-series predicted load heat quantity data, the operation condition of the fuel cell 1 in the operation cycle is determined so that the operation merit is high.
In the present invention, the operation control unit 5 manages and manages the time-series actual recovered heat amount data recovered by the heat recovery unit U3 based on the measurement information of the recovered heat amount measuring means 43. The time series predicted recovery heat quantity data predicted to be recovered by the heat recovery unit U3 on the basis of the time series actual recovery heat quantity data is divided and determined for each operation cycle. In addition to the predicted load power data and the time-series predicted load heat quantity data, the operation condition of the fuel cell 1 is determined based on the time-series predicted recovered heat quantity data so as to increase the operation merit. Yes.

  In this embodiment, the operation control unit 5 operates in a continuous operation mode in which the fuel cell 1 is operated over the entire time period of the operation cycle, in an intermittent operation mode in which the fuel cell 1 is operated in a part of the operation cycle, and in operation. Operation obtained based on time-series predicted load power data, time-series predicted load heat amount data, and time-series predicted recovered heat amount data from among standby modes in which the fuel cell 1 is stopped over the entire time period of the cycle By selecting the one having the highest merit, the operation condition of the fuel cell 1 is determined.

  Here, in this embodiment, the operation cycle is set to 1 day, and a plurality of unit times constituting the operation cycle are set to 1 hour. Further, the operation control unit 5 is configured to obtain a predicted energy reduction amount predicted to be obtained by operating the fuel cell 1 as an operation merit.

A description will be given of processing for obtaining time-series predicted load power data, time-series predicted load heat quantity data, and time-series predicted recovered heat quantity data by the operation control unit 5. Incidentally, the load heat amount data includes hot water supply load heat amount data when hot water is supplied to the hot water supply destination and terminal load heat amount data at the heat consuming terminal 3.
The operation control unit 5 stores the actual load power data, the actual hot water supply load heat amount data, the actual terminal load heat amount data, and the actual recovered heat amount data in the memory of the operation control unit 5 in association with the operation cycle and unit time, so that the past Time-series load power data, past time-series load heat energy data, and past time-series recovered heat energy data for each operation period over a set period (for example, 4 weeks before the operation day) Are configured to be managed in association with each other.
Incidentally, the actual load power is measured based on the measured value of the load power measuring means 11 and the output value of the inverter 6, the actual hot water supply load heat quantity is measured by the hot water supply load heat quantity measuring means 31, and the actual terminal load heat quantity is It is measured by the terminal load heat quantity measuring means 32, and the actual recovered heat quantity is measured by the recovered heat quantity measuring means 43.

  Then, the operation control unit 5 manages the management data of the time-series past load power data, the time-series past load heat amount data, and the time-series past recovered heat amount data at the start point of the operation cycle (for example, 3 am). Based on the above, time-series predicted load calorie data, time-series predicted load power data of the first operation cycle of the operation condition setting target period consisting of a plurality of (three in this embodiment) operation cycles arranged in time series Time-series predicted recovery heat quantity data, and time-series predicted load heat quantity data and time-series predicted recovery heat quantity data of all the operation periods subsequent to the first operation period in the operation condition setting target period. It is configured so as to be obtained by dividing every unit time. Incidentally, the time-series predicted load heat quantity data is data obtained by adding the time-series predicted hot water supply load heat quantity data and the time-series predicted terminal load heat quantity data, but in this embodiment, the heat load state Will be described assuming that no terminal load heat amount is generated at the heat consuming terminal 3 and only hot water load heat amount data is generated.

For example, as shown in FIG. 4, at the start of the operation cycle, as shown in FIG. 4, time-series predicted load power data, time-series predicted hot water supply load heat amount data, and time series of the first operation cycle in the operation condition setting target period Predictive heat recovery data is obtained every unit time, and all of the operation cycles subsequent to the first operation cycle in the operation condition setting target period (in FIG. 4, only a part of the second operation cycle is shown) Time series predicted hot water supply load heat quantity data and time series predicted recovered heat quantity data are obtained. Incidentally, the unit of predicted load power data is kWh, and the unit of predicted hot water supply load heat amount data and predicted recovered heat amount data is kcal / h.
In the result shown in FIG. 4, the amount of heat of 3000 kcal / h is recovered in each of the 21st unit time in the first operation cycle and the 20th unit time in the second operation cycle. It is predicted.

The operation mode of the fuel cell 1 will be described.
The continuous operation mode is an operation mode in which the output power of the fuel cell 1 is adjusted to the main output that follows the actual load power over the entire time period of the operation cycle.
In the intermittent operation mode, the predicted energy reduction amount (based on the operational merit) calculated based on the time-series predicted load power data, the time-series predicted load heat data, and the time-series predicted recovered heat data within the operation cycle. Corresponding time) is set as the operation time zone, and the operation of the fuel cell 1 is started at the start of the set operation time zone, and the output power of the fuel cell 1 is changed to the actual load power during the operation. This is an operation mode in which the operation of the fuel cell 1 is stopped when the electric power output to be followed is adjusted and the stop condition is satisfied.

  In the intermittent operation mode, when it is assumed that the fuel cell 1 is operated in a time zone within the first operation cycle of the operation condition setting target period, time series predicted load power data of the first operation cycle, time series Single cycle-compatible intermittent operation mode that determines the operation time zone in the time zone in which the predicted energy reduction amount obtained based on the typical predicted load heat amount data and time-series predicted recovered heat amount data is maximized, and operation condition setting When it is assumed that the fuel cell 1 is operated in a time zone within the first operation cycle of the target period, time-series predicted load power data, time-series predicted load calorie data, and time-series data of the first operation cycle Based on predicted heat recovery data and time-series predicted load heat data and time-series predicted heat recovery data of the operation cycle following the first operation cycle in the operation condition setting target period Predicted energy reductions are required to include intermittent operation mode of the plural-cycle corresponding type of setting the operation time zone to the time zone of maximum.

In the intermittent operation mode corresponding to the multiple cycles, the prediction is based on the time-series predicted load heat amount data and the time-series predicted recovered heat amount data of the first and second operation cycles in the operation condition setting target period. A two-cycle compatible type for obtaining an energy reduction amount, and a predicted energy reduction amount based on time-series predicted load heat amount data and time-series predicted recovered heat amount data for all operation cycles in the operation condition setting target period 3 There is a cycle correspondence type.
In this embodiment, since the operation cycle is set to one day, in the following description, the single-cycle compatible type, the two-cycle compatible type, and the three-cycle compatible type intermittent operation mode are respectively referred to as a one-day compatible type, It is described as an intermittent operation mode of a two-day correspondence type or a three-day correspondence type.

  In this embodiment, the amount of heat generated by operating the fuel cell 1 with the stop condition adjusting the output power based on the actual load power adjusts the output power based on the time-series predicted load power. In such a form, the condition is set so as to reach the amount of heat that is expected to be generated when the fuel cell 1 is assumed to be operated during the operation time period.

By the way, 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 determined in advance by experiments or the like as standby energy consumption Z and stored in the memory of the operation control unit 5. For example, the standby energy consumption Z is obtained by the following equation.
Z = power consumption during standby × standby time / power generation efficiency of commercial power supply 7

The predicted energy reduction amount in the continuous operation mode and the predicted energy reduction amount in the intermittent operation mode may be obtained as negative values.
For example, when the predicted energy reduction amount in the continuous operation mode obtained as a negative value is larger than the negative value of the standby energy consumption Z, the fuel cell 1 is operated in the continuous operation mode. When the predicted energy reduction amount in the continuous operation mode obtained as a negative value is smaller than the negative value of the standby energy consumption Z, the fuel cell 1 is continuously operated. It is energy saving to wait for driving rather than driving at.

  The operation control unit 5 executes an operation mode selection process at the start of each operation cycle. In the operation mode selection process, the continuous operation mode, the 1-day type intermittent operation mode, the 2-day type intermittent operation mode, and Obtaining the predicted energy reduction amount for each of the three-day type intermittent operation modes, a continuous operation mode, a one-day type intermittent operation mode, a two-day type intermittent operation mode, a three-day type intermittent operation mode, and Among the standby modes, the most excellent one in terms of energy saving is configured as the operation mode of the fuel cell 1.

  That is, the operation control unit 5 calculates the predicted energy reduction amount for each of the continuous operation mode, the 1-day intermittent operation mode, the 2-day intermittent operation mode, and the 3-day intermittent operation mode obtained as described above. If the largest one of them is larger than the negative value of standby energy consumption Z, the continuous operation mode, the 1-day type intermittent operation mode, the 2-day type intermittent operation mode and the 3-day type Of the intermittent operation modes, the fuel cell 1 having the largest amount of predicted energy reduction is determined as the operation mode of the fuel cell 1, and the continuous operation mode, the one-day type intermittent operation mode, the two-day type intermittent operation mode, and the three-day type. When the largest of the predicted energy reduction amounts of the intermittent operation modes is equal to or less than the negative value of the standby energy consumption Z, the standby mode is determined as the operation mode of the fuel cell 1.

Next, a description will be given of processing for obtaining the predicted energy reduction amount for each of the plurality of types of operation modes by the operation control means 5.
As shown in the following formula 2, the predicted energy reduction amount in each operation mode is the predicted energy consumption amount when the fuel cell 1 is operated in each operation mode from the predicted energy consumption amount when the fuel cell 1 is not operated. Calculate by subtracting.

  Predicted energy reduction amount P = predicted energy consumption amount E1 when the fuel cell 1 is not operated E1-predicted energy consumption amount E2 when the fuel cell 1 is operated (equation 2)

  The predicted energy consumption E1 (kWh) when the fuel cell 1 is not operated is the commercial energy when all of the predicted load power in the first operation cycle is supplemented with the received power from the commercial power supply 7, as shown in the following formula 3. It is obtained as the sum of the predicted energy consumption in the power source 7 and the predicted energy consumption when all of the predicted load heat amount in the first operation cycle is supplemented with the heat generated by the auxiliary heater 28.

  E1 = predicted load power / commercial power generation efficiency + predicted load calorie / auxiliary heater thermal efficiency (Equation 3)

However,
The predicted load heat amount is a value converted into kWh.
The auxiliary heater thermal efficiency is the heat generation efficiency of the auxiliary heater 28 and is the ratio of the amount of generated heat to the unit energy consumption in the auxiliary heater 28.

  On the other hand, the predicted energy consumption E2 (kWh) when the fuel cell 1 is operated is calculated by using the predicted load power and the predicted load heat amount of the first operation cycle as the predicted output power of the fuel cell 1 and Receiving from the commercial power supply 7 all of the predicted energy consumption of the operation cycle, which is the energy consumed by the fuel cell 1 when supplemented with the predicted heat output, and the predicted insufficient power corresponding to the predicted load power minus the predicted output power. It is obtained by the sum of the predicted energy consumption in the commercial power source 7 when supplemented with electric power and the predicted energy consumption when all of the predicted insufficient heat is supplemented with the heat generated by the auxiliary heater 28.

  E2 = Operating cycle predicted energy consumption + predicted insufficient power amount / commercial power generation efficiency + predicted insufficient heat amount / auxiliary heater thermal efficiency + energy consumption at start-up (Equation 4)

  The operation cycle predicted energy consumption of the above equation 4 is obtained by calculating the predicted energy consumption per unit time obtained by calculating the predicted energy consumption per unit time for operating the fuel cell 1 in each operation mode in the following equation 5. Obtained by integrating consumption.

Predicted energy consumption = Predicted output power ÷ Battery power generation efficiency ......... (Formula 5)
However, the battery power generation efficiency indicates the ratio of the output power (kWh) to the unit energy consumption (kWh) in the fuel cell 1, is set according to the output power, and is stored in the memory of the operation control unit 5.

  The predicted insufficient heat quantity of the above equation 4 is obtained by subtracting the predicted hot water storage heat quantity of the hot water tank 2 in the unit time immediately before the unit time from the predicted hot water supply load heat quantity of the unit time for which the predicted insufficient heat quantity is obtained, and is in units of kWh. Is converted to

The predicted amount of stored hot water in the hot water tank 2 is the amount of heat that is predicted to be stored in the hot water tank 2 with hot water, and the predicted amount of stored hot water (kcal / h) for each unit time is obtained by the following equations 6 and 7. It is done. That is, it is obtained by subtracting the predicted hot water supply load heat amount of the unit time for obtaining the predicted hot water storage amount from the predicted heat output and the predicted recovered heat amount of the unit time for obtaining the predicted hot water heat amount to the predicted hot water storage amount of the immediately preceding unit time. . However, heat dissipation from the hot water tank 2 is taken into consideration.
In each equation, the subscript “n” indicates the order of unit times in the operation cycle. For example, when n = 1, the first unit time in the operation cycle is indicated.
However, the predicted hot water storage amount ₀ as the predicted hot water storage amount _n-1 in equation 6 when n = 1 is the predicted hot water storage amount at the start of the operation cycle, and is a value obtained based on the above equation 1. The

Predicted hot water storage amount _n = (Predicted hot water storage amount _n-1 −Predicted hot water supply heat amount _n + Predicted heat output _n + Predicted recovered heat amount _n ) × (1−tank heat dissipation rate) (Equation 6)
Predicted thermal output _n = α × {(predicted output power _n ÷ battery power generation efficiency) × battery thermal efficiency} + surplus power × α × β-base heat dissipation amount (equation 7)

However,
The tank heat dissipation rate of the above formula 6 is the heat dissipation rate from the hot water storage tank 2, and is preset to 0.012, for example, and stored in the memory of the operation control unit 5.
The battery thermal efficiency of Equation 7 indicates the ratio of the generated heat amount (kWh) to the unit energy consumption (kWh) in the fuel cell 1, is set according to the output power, and is stored in the memory of the operation control unit 5.
In this cogeneration system, the base heat release amount is the amount of heat radiated without being used for hot water storage in the hot water storage tank 2 and heating by the heat consuming terminal 3 out of the generated heat amount of the fuel cell 1. .
The surplus power is obtained by subtracting the predicted load power from the predicted output power when the predicted output power is larger than the predicted load power.
For example, when the predicted load power is smaller than the minimum output in the output power adjustment range of the fuel cell 1, the surplus power can be obtained by subtracting the predicted load power from the minimum output of the fuel cell 1.
α is a coefficient set to 860 as described above.
β is a heater efficiency that is an efficiency when the electric heater 12 converts surplus power (kWh) into heat (kWh), and is set in advance.

  The energy consumption at start-up of the above equation 4 includes energy required for warming up the reformer, the transformer, and the like constituting the fuel cell 1 to temperatures set so as to enable the respective processes. These are obtained in advance by experiments or the like and stored in the memory of the operation control unit 5.

Hereinafter, the process for obtaining the predicted energy reduction amount by the operation control unit 5 will be described for each operation mode.
The predicted energy reduction amount Pc1 in the continuous operation mode is obtained as follows.
That is, the predicted energy consumption E1 when the fuel cell 1 is not operated is obtained from Equation 3, and the startup energy consumption is not consumed (ie, startup energy consumption = 0) according to Equation 4, so that the fuel cell 1 The predicted energy consumption amount E2 when the vehicle is operated is obtained, and the predicted energy reduction amount Pc1 is obtained from Equation E2 using E1 and E2.
Note that the predicted energy consumption for each unit time is obtained as the main output by using Equation 5 as the predicted output power, and the predicted energy consumption for each unit time is integrated to obtain the predicted operation period energy consumption. Then, based on the operation cycle predicted energy consumption obtained as described above, the predicted energy consumption E2 when the fuel cell 1 is operated is obtained by Expression 4.

The predicted energy reduction amount Pi1 in the one-day type intermittent operation mode is obtained as follows.
That is, out of a plurality of unit times of the operation cycle, the selected one or a plurality of continuous unit times are set as unit times constituting the operation time zone, and the remaining unit time of the operation cycle is stopped to stop the fuel cell 1 By changing the unit time selected as the unit time constituting the operation time zone in the form of the unit time constituting the time zone, all temporary operation patterns are formed, and among all the temporary operation patterns, the operation is performed. All the temporary operation patterns except for the pattern in which the entire unit time of the cycle is an operation time zone are stored in the memory of the operation control unit 5 as temporary operation patterns for one-day type intermittent operation.

  That is, as a pattern for starting operation from the first unit time, a pattern having the first unit time as an operation time zone, a pattern having first and second unit times as an operation time zone, There are 23 types of patterns in which the third unit time is used as an operating time zone: patterns in which the first to 23rd unit times are used as operating time zones. In addition, as a pattern for starting operation from the second unit time, a pattern using the second unit time as an operation time zone, a pattern using the second and third unit times as an operation time zone, etc. There are 23 types of patterns in which the second to 24th unit time is an operation time zone. As described above, there are 299 types of temporary operation patterns for one-day intermittent operation up to a pattern in which the last 24th unit time of the operation cycle is an operation time zone.

  It is assumed that the fuel cell 1 is operated in a state where the output power is adjusted to the main output in the operation time zone set in each temporary operation pattern for each of the temporary operation patterns for all the one-day intermittent operation. Thus, the predicted energy consumption E1 when the fuel cell 1 is not operated is obtained from the equation 3, the estimated energy consumption E2 when the fuel cell 1 is operated is obtained from the equation 4, and the equation E1 and E2 is used to obtain the equation 2 to obtain a predicted energy reduction amount P. Further, the predicted heat output and the predicted hot water storage amount are obtained for each unit time of the first operation cycle.

  However, when the fuel cell 1 is operated according to Equation 4, when the fuel cell 1 is stopped at the start of the operation cycle, the startup energy consumption is calculated for all temporary operation patterns. When the fuel cell 1 is in operation at the start of the operation cycle, the predicted energy consumption E2 is determined to be consumed, and the startup energy consumption is consumed for the temporary operation pattern in the operation time period starting from the start of the operation cycle. The predicted energy consumption amount E2 is calculated as not being performed (that is, the startup energy consumption amount = 0), and the startup energy consumption amount is predicted for the operation pattern in the operation time period starting with an interval from the start point of the operation cycle. The energy consumption E2 is obtained.

Further, the predicted energy consumption of unit time included in the operation time zone is obtained by calculating the predicted output power as the main output by Equation 5, and the predicted energy consumption amount of unit time not included in the operation time zone is set to 0. By integrating the predicted energy consumption of time, the operation cycle predicted energy consumption is obtained.
Further, the predicted heat output of unit time not included in the operation time zone is 0, and the predicted hot water storage amount of unit time not included in the operation time zone is obtained by using Equation 6 with the predicted heat output _n being 0.

  Then, a temporary operation pattern having the maximum predicted energy reduction amount is obtained from all the temporary operation patterns for the one-day type intermittent operation, and the temporary operation pattern is set to the one-day type intermittent operation mode operation pattern. Then, the predicted energy reduction amount of the temporary operation pattern is obtained as the predicted energy reduction amount Pi1 of the one-day type intermittent operation mode.

The predicted energy reduction amount of the two-day load following intermittent operation mode is obtained as follows.
That is, among all the temporary operation patterns obtained by adding the temporary operation pattern with all unit times of the operation cycle as the operation time zone to the temporary operation pattern for all-day intermittent operation, as described above, the operation time zone When the output power is adjusted to the main output in step 1, the temporary operation pattern in which the predicted hot water storage heat amount in the last unit time in the first operation cycle is greater than 0 is selected as the two-day temporary operation pattern.
Then, for all of the two-day tentative temporary operation patterns, assuming that the predicted hot water storage amount for the last unit time of the first operation cycle is used as the predicted hot water supply load heat amount for the second operation cycle, For each of a plurality of unit times, a predicted heat use amount used as a predicted hot water storage heat amount and a predicted hot water supply load heat amount is obtained.
The predicted amount of stored hot water for each unit time is obtained from the above equation 6 with the predicted heat output _{n set} to zero.
Further, the predicted amount of heat used for each unit time is obtained by the following equations 8 to 10.

When the predicted hot water storage amount _n-1 ≧ predicted hot water supply load heat amount _n ,
Predicted use heat quantity _n = Predicted hot water supply load heat quantity _n ............... (Formula 8)
Predicted hot water storage calorie _n-1 <predicted hot water supply heat calorie _n ,
Predicted heat consumption _n = Predicted hot water storage amount _n-1 (Equation 9)
When the predicted amount of stored hot water _n-1 = 0,
Predicted heat consumption _n = 0 ... (Equation 10)

For each of the two-day tentative temporary operation patterns, the predicted energy reduction amount of the one-day responsive intermittent operation mode obtained as described above is converted into the predicted use heat amount (converted to kWh) in the second operation cycle. The predicted energy reduction amount is obtained by adding the predicted energy consumption (total predicted use heat amount / auxiliary heater thermal efficiency) when the total is supplemented with the heat generated by the auxiliary heater 28, and the calculated predicted energy reduction amount is 2 The energy reduction amount per operation cycle (one day) is divided into the predicted energy reduction amount of the 2-day correspondence type temporary operation pattern.
Then, among all the two-day tentative operation patterns, the two-day tentative temporary operation pattern having the maximum predicted energy reduction amount is set as the operation pattern of the two-day responsive intermittent operation mode, and the two days The predicted energy reduction amount of the corresponding temporary operation pattern is obtained as the predicted energy reduction amount Pi2 of the two-day intermittent operation mode.

FIG. 4 shows an example of a temporary operation pattern in which the unit time from the fifth to the 23rd unit is an operation time zone, and predicts a one-day intermittent operation using a temporary operation pattern for a one-day intermittent operation. When obtaining the energy reduction amount, the result of obtaining the predicted heat output and the predicted hot water storage amount for each unit time of the first operation cycle, and when obtaining the predicted energy reduction amount of the 2-day type intermittent operation, 2 The result of having calculated | required hot water storage heat quantity and use heat quantity for each unit time of the operation period of the 1st time is shown.
However, the portion of the column in which the operation cycle in FIG. 4 is “first” (that is, the portion of the upper table in FIG. 4) is the predicted heat output and prediction when the predicted energy reduction amount of the one-day type intermittent operation is obtained. The calculation result of the amount of stored hot water is shown. Further, the portion of the column in which the operation cycle is “second” in FIG. 4 (that is, the portion of the lower table in FIG. 3) is the predicted amount of stored hot water when obtaining the predicted energy reduction amount of the 2-day type intermittent operation. And the calculation result of predicted use heat quantity is shown.

The predicted energy reduction amount Pi3 in the 3-day type intermittent operation mode is obtained as follows.
That is, out of all the two-day provisional operation patterns, the temporary operation pattern in which the predicted hot water storage heat amount in the final unit time in the second operation cycle is larger than 0 is selected as the three-day correspondence temporary operation pattern, Assuming that the predicted hot water storage amount of the last unit time of the second operation cycle is used as the predicted hot water supply load heat amount of the third operation cycle for all the three-day provisional operation patterns, the second operation cycle described above As in the above, the predicted hot water storage amount and the predicted use heat amount are obtained for each of a plurality of unit times in the third operation cycle.

For each of the three-day tentative temporary operation patterns, the predicted energy reduction amount of the one-day responsive intermittent operation mode obtained as described above was converted into the predicted heat consumption (kWh) in the second and third operation cycles. The predicted energy reduction amount is calculated by adding the predicted energy consumption (total of the predicted use heat amount / auxiliary heater thermal efficiency) in the case of supplementing the total of the heat) with the generated heat of the auxiliary heater 28, and the calculated predicted energy reduction amount Is divided by 3 to obtain an energy reduction amount per one operation cycle (one day), which is a predicted energy reduction amount of the temporary operation pattern corresponding to the three days.
Then, among all the three-day provisional operation patterns, the three-day correspondence temporary operation pattern having the maximum predicted energy reduction amount is set as the operation pattern of the three-day correspondence intermittent operation form, and the three days The predicted energy reduction amount of the responsive temporary operation pattern is obtained as the predicted energy reduction amount Pi3 of the 3-day compatible intermittent operation mode.

The stop condition will be described.
The operation controller 5 assumes that the fuel cell 1 is operated during the operation time period in a form in which the output power is adjusted to the predicted load power. The target heat generation amount is obtained by integrating the predicted heat output for each hour.
Further, the operation control unit 5 operates the fuel cell 1 in such a manner that the output power is adjusted to the main output that follows the actual load power from the start time of the operation time period, and the following equation 11 is used for each unit time. The actual heat output is obtained, and the accumulated actual heat output is obtained by integrating the obtained actual heat output per unit time.

  Actual heat output = α × {(main power output ÷ battery power generation efficiency) × battery heat efficiency} + surplus power × α × β−base heat dissipation amount (Equation 11)

  Then, the operation control unit 5 compares the accumulated actual generated heat amount with the target generated heat amount during the operation of the fuel cell 1, and determines that the stop condition is satisfied when the accumulated actual generated heat amount is equal to or greater than the target generated heat amount. 1 is stopped.

Hereinafter, the control operation of the operation control unit 5 will be described based on the flowcharts shown in FIGS. 5 and 6.
First, based on FIG. 5, the control operation in the operation mode setting process will be described.
When the operation control unit 5 reaches the start point of the operation cycle (for example, 3:00 am), the operation control unit 5 executes a predicted load data calculation process to calculate time-series predicted load power data, time-series predicted load heat amount data, and Then, time-series predicted recovery heat amount data is obtained, and then the predicted energy reduction amount calculation process is executed to predict the predicted energy reduction amount Pc in the continuous operation mode and the predicted energy reduction amount Pi1 in the one-day type intermittent operation mode. The predicted energy reduction amount Pi2 of the 2-day type intermittent operation mode and the predicted energy reduction amount Pi3 of the 3-day type intermittent operation mode are obtained (steps # 1 to # 3).

Subsequently, in Step # 4, the predicted energy reduction amount Pi of the 1-day type intermittent operation mode, the predicted energy reduction amount Pi2 of the 1-day type intermittent operation mode, and the predicted energy of the 3-day type intermittent operation mode. The largest reduction amount Pi3 is set as the predicted energy reduction amount Pi of the intermittent operation mode.
Subsequently, in step # 5, the larger one of the predicted energy reduction amount Pc in the continuous operation mode and the predicted energy reduction amount Pi in the intermittent operation mode is larger than the negative value “−Z” of the standby energy consumption Z. If it is larger (step # 5: Yes), the process proceeds to step # 7. If it is not larger (step # 5: No), the operation mode of the fuel cell 1 is set to the standby mode (step # 5). # 6).

In step # 7, the predicted energy reduction amount Pc in the continuous operation mode is compared with the predicted energy reduction amount Pi in the intermittent operation mode. If Pc ≧ Pi (step # 7: Yes), in step # 8, The operation mode of the fuel cell 1 is set to the continuous operation mode.
If it is determined in step # 7 that Pc ≧ Pi is not satisfied (step # 7: No), the thermal load coverage rate U / L is obtained in step # 9, and in step # 10, the obtained thermal load coverage is obtained. When the rate U / L is compared with the set value K and the thermal load coverage rate U / L is greater than the set value K (step # 10: Yes), the operation mode of the fuel cell 1 is determined at step # 6. Is set to the standby mode, and the thermal load coverage ratio U / L is equal to or smaller than the set value K (step # 10: No), the predicted energy reduction amount is maximized in step # 11. Set to intermittent operation mode.

Incidentally, L of the thermal load coverage ratio U / L is the predicted hot water supply load heat amount of the operation cycle obtained by summing the predicted hot water supply load heat amount of each unit time of the first operation cycle.
Further, U of the thermal load cover rate U / L can be covered by the amount of stored hot water at the start of the first operation cycle out of the predicted hot water supply load heat amount of the first operation cycle, assuming the predicted output heat amount of the fuel cell 1 as 0. This is the predicted amount of heat used in the predicted operation cycle.
That is, assuming that the hot water storage heat amount at the start of the first operation cycle is used as the predicted hot water supply load heat amount of the operation cycle, the predicted hot water storage amount and the predicted use heat amount are obtained for each of a plurality of unit times of the operation cycle. By summing the predicted usage heat amount of time, the predicted usage heat amount U of the operation cycle is obtained.
The set value K is set to 0.4, for example.

Then, the operation control means 5 operates the fuel cell 1 in the operation mode determined by the operation mode selection process.
When the operation mode of the fuel cell 1 is set to the standby mode, the fuel cell 1 is stopped over the entire time period of the operation cycle.
When the operation mode of the fuel cell 1 is set to the continuous operation mode, an actual load power follow-up operation is performed in which the output power of the fuel cell 1 follows the actual load power over the entire time period of the operation cycle.
In the actual load power follow-up operation, the actual load power is obtained at a relatively short predetermined output adjustment cycle such as one minute, and the main output that continuously follows the actual load power within the range from the minimum output to the maximum output is obtained. The operation is performed in such a manner that the output power of the fuel cell 1 is adjusted to the determined main output.
The actual load power is measured based on the measured value of the load power measuring means 11 and the output value of the inverter 6, and the actual load power is measured at a predetermined sampling time (for example, 5 seconds) in the previous output adjustment period. Calculated as the average value of sampled data.

  When the operation mode of the fuel cell 1 is set to the intermittent operation mode, the actual load power follow-up operation is started at the start time of the operation time zone set in the operation mode selection process, and the actual load power follow-up operation is being executed. Determines whether or not the stop condition is satisfied by determining whether or not the accumulated actual generated heat quantity is equal to or greater than the target generated heat quantity, and if the stop condition is satisfied by the start of the next operation cycle, the fuel When the battery 1 is stopped and the stop condition is not satisfied, the operation mode selection process is executed when the next operation cycle starts.

That is, the operation mode selection process is executed every time the operation cycle starts, and in the operation mode selection process, as described above, when the thermal load coverage rate U / L is larger than the set value K, the fuel cell 1 operation mode is set to the standby mode.
Therefore, in the previous operation mode selection process, the operation mode of the fuel cell 1 is set to the 2-day correspondence type or the 3-day correspondence type intermittent operation mode, and the time when the current operation mode selection process is performed is the 2-day correspondence type or When it corresponds to the start time of the second operation cycle in the three-day type intermittent operation mode and is set to the standby mode as described above in the operation mode selection process, the entire operation period of the operation cycle The fuel cell 1 is stopped, and the two-day or three-day intermittent operation mode is continued.

  In the 2-day or 3-day intermittent operation mode, the actual hot water supply load heat amount in the first operation cycle is larger than the predicted hot-water supply load heat amount, or in the 3-day type intermittent operation mode. When the actual hot water supply load heat amount in the second operation cycle becomes larger than the predicted hot water supply load heat amount, and the heat load coverage rate U / L becomes equal to or less than the set value K, the operation mode of the fuel cell 1 is newly set to 1 day. The predicted energy reduction amount in the intermittent operation mode of the correspondence type, the two-day correspondence type, and the three-day correspondence type is determined to be the maximum intermittent operation mode.

Next, a control operation in the heat recovery operation will be described based on FIG.
When the bath use end switch 51c is turned on (step # 21: Yes), the operation control unit 5 operates the bath circulation pump 37, the water flow switch 48 is turned on (step # 23: Yes), and heat The detected temperature Tb of the pre-exchange temperature sensor 44 is higher than the detected temperature T4 of the lower end temperature sensor S4 (Step # 24: Yes), and the detected temperature Tb of the pre-exchange temperature sensor 44 is the time interval between the current time and the set time. If the temperature is higher than the processing stop set temperature Ts obtained according to the above (step # 25: Yes), the heat recovery operation can be executed, so the process proceeds to the next step # 26 for executing the heat recovery operation. .
On the other hand, when the water flow switch 48 is off (step # 23: No), even when the water flow switch 48 is on, the detected temperature Tb of the temperature sensor 44 before heat exchange is equal to or lower than the detected temperature T4 of the lower end temperature sensor S4 (step # 24). : No), and even if the water flow switch 48 is ON and the detected temperature Tb of the pre-heat exchange temperature sensor 44 is higher than the detected temperature T4 of the lower end temperature sensor S4, the detected temperature Tb of the pre-heat exchange temperature sensor 44 is If the temperature is equal to or lower than the processing stop set temperature Ts obtained according to the time interval up to the set time (step # 25: No), the heat recovery operation cannot be executed, and the process returns.

In step # 26, the three-way valve 41 is switched to the heat exchange state, and the heat recovery operation is started. However, it is determined in step # 27 whether or not the hot water storage operation is being executed. If not, the hot water circulation pump 17 is operated in step # 28.
Thereafter, the detected temperature Tb of the pre-heat exchange temperature sensor 44 is higher than the detected temperature T4 of the lower end temperature sensor S4, and the detected temperature Tb of the pre-heat exchange temperature sensor 44 is obtained according to the time interval between the current time and the set time. The heat recovery operation is continued while the state (step # 29: Yes, step # 30: Yes) higher than the set processing stop temperature Ts is satisfied.
On the other hand, whether the detected temperature Tb of the pre-heat exchange temperature sensor 44 is equal to or lower than the detected temperature T4 of the lower end temperature sensor S4 (step # 29: No), or the detected temperature Tb of the pre-heat exchange temperature sensor 44 is lower end temperature sensor S4. Even if the detected temperature T4 is higher than the detected temperature T4, if the detected temperature Tb of the pre-heat exchange temperature sensor 44 is equal to or lower than the set temperature Ts for processing stop determined according to the time interval between the current time and the set time (step # 30: No) Then, the bath circulation pump 37 is stopped, the three-way valve 41 is switched to the non-heat exchange state (steps # 31 and 32), the heat recovery operation is terminated, and whether the current hot water storage operation is to be executed or not. If it is not in a state to be executed (step # 33: No), the hot water circulation pump 17 is also stopped (step # 34) and the process returns.

[Another embodiment]
Next, another embodiment will be described.
(A) The specific configuration of the heat medium heating circulation unit U2 is not limited to the configuration described in the above embodiment.
For example, in the configuration of the cogeneration system described in the above embodiment, the heat consumption terminal 3 is applied as the heat consumption unit B, and the heat medium heating circulation unit U2 is connected to the heat medium circulation path R via the heat consumption terminal 3. The terminal heating medium circulation path 22, the terminal heating medium circulation pump 23 that circulates the heating medium through the terminal heating medium circulation path 22, and the heating medium that flows through the terminal heating medium circulation path 22 are heated. You may comprise and comprise a heating means. That is, a floor heating device or a bathroom heating / drying device is applied as the heat consuming part B. In this case, the heating unit may have the same configuration as in the above embodiment, or a heat source device may be provided so as to directly heat the heat medium flowing through the terminal heat medium circulation path 22.
Moreover, when the bathtub 33 is applied as the heat consuming part B as in the above embodiment, the hot water in the bathtub 33 flowing through the bath circulation path 36 is used not only in the auxiliary heater 28 but also in the hot water storage tank 2. You may comprise so that it may heat by.
Further, the heat medium heating circulation unit U2 is configured to circulate and supply hot water in the hot water tank 2 to the heat consuming part B through the heat medium circulation path R, and heats the heat medium flowing through the heat medium circulation path R. The heating means may be omitted.
Furthermore, the hot water extracted from the bottom of the hot water tank 2 is passed through the fuel cell 1 and then returned to the top of the hot water tank 2, and the battery for circulating the hot water in the hot water tank 2 through the hot water circulating path via the battery. An intermediate circulation pump is provided, and the hot water storage unit U1 is configured by including the intermediate battery hot water circulation path and the intermediate battery circulation pump.
The heat recovery unit U3 may be configured to exchange heat between the heat medium in the heat medium recirculation path R and the hot water flowing through the battery upstream hot water circulation path upstream of the fuel cell 1. good.

(B) In the above embodiment, the heat recovery unit U3 is configured to exchange heat between the heat medium in the heat medium circulation path R and the hot water in the hot water tank 2, but in the heat medium circulation path R, You may comprise so that heat exchange and the water (water which flows through the water supply path 35 in said embodiment) supplied to the hot water storage tank 2 from the outside may be heat-exchanged.
In this case, the temperature relationship between the heat medium in the heat medium circulation path R exchanged in the heat recovery unit U3 and the water supplied to the hot water tank 2 from the outside is the temperature of the heat medium in the heat medium circulation path R. The heat recovery unit U3 is configured to operate under a high condition.

(C) The specific configuration of the heat consumption end input means is limited to the configuration described in the above embodiment, that is, the bath use end switch 51c for inputting bath use end information as heat consumption end information by human operation. Instead, the configuration may be such that the heat consumption end information is automatically input.
For example, when timer means for automatically stopping when the operation of the heating medium heating circulation unit U2 such as a floor heating device or a bathroom heating / drying device is timed up is provided, heat consumption end information is input to time up. In this manner, the timer means may function as a heat consumption end input means.

(D) The specific configuration of the recovered heat quantity measuring means 43 is limited to the configuration of the above embodiment, that is, the configuration including the temperature sensor 44 before heat exchange, the temperature sensor 45 after heat exchange, and the bath circulation flow sensor 46. is not.
For example, a water level sensor 47 and a pre-heat exchange temperature sensor 44 are provided, and the water level detected by the water level sensor 47 and the temperature of the hot water in the bathtub 33 detected by the pre-heat exchange temperature sensor 44 are heated. It may be configured to measure the heat quantity related information for obtaining the heat quantity recovered by the recovery means U3. Incidentally, the amount of hot water in the bathtub 33 is obtained based on the water level detected by the water level sensor 47, and the amount of heat recovered by the heat recovery means U3 based on the amount of hot water and the temperature detected by the temperature sensor 44 before heat exchange. Will be asked.

(E) In the above embodiment, the processing avoidance set temperature range is set so as to increase as the time interval becomes longer according to the time interval up to the set time, but it may be set to a predetermined constant value. good.

(F) In the hot water circulation type freezing prevention operation, the bath heating section 28B of the auxiliary heater 28 is heated and operated through the bath circulation path 36 while being heated by the bath heating section 28B of the auxiliary heater 28. The freeze prevention means D may be configured by the bath circulation pump 37 and the auxiliary heater 28 so as to prevent the heat medium from freezing by circulating the heat.

(G) The specific configuration of the recovered heat quantity acquisition means is not limited to the recovered heat quantity measurement means 43 exemplified in the above embodiment. For example, the amount of heat held by the heat medium in the heat medium circulation path R is determined. It is also possible to obtain the amount of heat that can be recovered by the heat recovery unit U3 from the determined amount of heat. Incidentally, since the capacity of the heat medium stored in the heat medium recirculation path R is known in advance, the temperature of the heat medium in the heat medium recirculation path R is measured, and the measured temperature and the capacity of the heat medium known in advance are calculated. The amount of heat possessed by the heat medium in the heat medium circulation path R can be obtained.
In this case, regardless of whether or not the heat amount is actually recovered from the heat medium in the heat medium circulation path R, the predicted recovered heat amount data is obtained using the heat amount that can be recovered from the heat medium in the heat medium circulation path R. Therefore, the heat possessed by the heat medium in the heat medium circulation path R can be used more effectively.

(H) When the heat consuming terminal 3 is applied as the heat consuming part B and the antifreeze liquid is used as the heat medium in the heat medium circulation path R, the freeze prevention means D is not necessary.
Therefore, in this case, until the temperature relationship between the heat medium in the heat medium circulation path R exchanged in the heat recovery unit U3 and the hot water in the hot water tank 2 or the water supplied to the hot water tank 2 from the outside becomes equal to each other. The heat recovery unit U3 can be activated.

(I) The operation merit is not limited to the energy reduction amount described in the above embodiment, but the estimated energy cost reduction amount by operating the fuel cell 1 or by operating the fuel cell 1 The predicted amount of carbon dioxide reduction can be used.
Incidentally, the predicted energy cost reduction amount can be obtained by subtracting the energy cost when the fuel cell 1 is operated from the energy cost when the fuel cell 1 is not operated.
The energy cost when the fuel cell 1 is not operated includes the cost when purchasing all of the predicted load power from the commercial power source 7 and the energy cost (fuel cost) when supplying the predicted load heat amount with the auxiliary heater 28. It is calculated as the sum of
On the other hand, the energy cost when the fuel cell 1 is operated is predicted to be the energy cost (fuel cost) of the fuel cell 1 when the predicted load power and the predicted load heat amount are supplemented with the predicted generated power of the fuel cell 1 and the predicted generated heat. It is obtained as the sum of the cost for purchasing the amount of insufficient power from the commercial power source 7 and the energy cost (fuel cost) for supplementing the predicted insufficient heat amount with the heat generated by the auxiliary heater 28.

The predicted carbon dioxide reduction amount can be obtained by subtracting the carbon dioxide generation amount when the fuel cell 1 is operated 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 all of the predicted load power is purchased from the commercial power source 7 and the amount of predicted load heat is covered by the auxiliary heater 28. Calculated as the sum of carbon dioxide generation.
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 load power and the predicted load heat amount are supplemented with the predicted generated power and the predicted generated heat of the fuel cell 1, and It is obtained as the sum of the carbon dioxide generation amount when purchasing the predicted insufficient power amount from the commercial power supply 7 and the carbon dioxide generation amount when the predicted insufficient heat amount is supplemented with the heat generated by the auxiliary heater 28.

(Nu) The method for determining the operating conditions of the fuel cell 1 is determined by selecting the one described in the above embodiment, that is, among the continuous operation mode, the intermittent operation mode, and the standby mode, which has high driving merit. It is not limited to how to determine the conditions.
For example, you may comprise so that driving | running conditions may be defined by selecting a thing with a high driving | operation merit from any two of a continuous driving | running mode, an intermittent driving | running mode, and a standby mode.
Or when performing only an intermittent operation form, you may comprise so that driving | running conditions may be defined by setting the time slot | zone with the driving | operation merit which was excellent in the driving | operation period to the driving | operation time slot | zone.

(L) In the above embodiment, the fuel cell 1 is applied as the combined heat and power supply device, but various other devices such as a configuration in which a generator is driven by an engine can be applied.

  As described above, it is possible to provide a cogeneration system capable of operating a combined heat and power supply device so as to suppress excess and deficiency of heat even when heat is recovered from the heat medium in the heat medium circulation path to hot water in the hot water tank. it can.

DESCRIPTION OF SYMBOLS 1 Cogeneration apparatus 2 Hot water storage tank 5 Operation control means 33 Bathtub 43 Recovery heat amount measurement means, Recovery heat amount acquisition means 51c Heat consumption end input means B Heat consumption part D Freezing prevention means R Heat medium circulation path U1 Hot water storage means U2 Heat medium heating circulation Means U3 Heat recovery means

Claims (8)

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 manages the time-series predicted load power data and the time-series predicted load calorie data separately for each operation cycle, and at the start of the operation cycle, the time-series predicted load Based on the power data and the time-series predicted load calorie data, a cogeneration system configured to determine the operating conditions of the combined heat and power device in the operating cycle so that the operating merit is high,
A heat medium heating circulation unit capable of circulating a heat medium for supplying heat through a heat medium circulation path passing through the heat consumption part to supply heat to the heat consumption part, and heat of the heat medium circulation path Heat recovery means capable of recovering heat from the heat medium in the heat medium circulation path to the hot water in the hot water tank by exchanging heat between the medium and hot water in the hot water tank or water supplied to the hot water tank from the outside And a recovered heat quantity acquisition means for acquiring heat quantity related information for obtaining the heat quantity recoverable by the heat recovery means or the heat quantity, and
The operation control means is
Based on the acquired information of the recovered heat quantity acquisition means, manages the time-series actual recovered heat quantity data that can be recovered by the heat recovery means, and based on the managed time-series actual recovered heat quantity data It is configured to obtain the time-series predicted recovered heat quantity data predicted to be recovered by the heat recovery means, divided for each operation cycle, and
In addition to the time-series predicted load power data and the time-series predicted load calorie data, the operating conditions are determined based on the time-series predicted recovered heat amount data so that the operation merit is increased. Constructed cogeneration system. Heat consumption end input means for inputting heat consumption end information indicating that the heat consumption in the heat consumption unit has ended by human operation is provided,
The cogeneration system according to claim 1, wherein the operation control means is configured to operate the heat recovery means when the heat consumption end information is input by the heat consumption end input means.   The operation control means has a temperature relationship between the heat medium in the heat medium circulation path exchanged in the heat recovery means and hot water in the hot water storage tank or water supplied to the hot water storage tank from the outside. The cogeneration system according to claim 2, wherein the heat recovery unit is configured to operate under a condition where the temperature of the heat medium in the circulation path is higher. Freezing prevention means for preventing freezing of the heating medium in the heating medium circulation path is provided,
The operation control means is
When the temperature of the heat medium in the heat medium circulation path is equal to or lower than the processing start set temperature, the freeze prevention means is configured to be operated, and
When the heat recovery means is in operation, the heat recovery means is stopped when the temperature of the heat medium in the heat medium circulation path becomes equal to or lower than the process avoidance set temperature range than the process start set temperature. The cogeneration system according to claim 3 configured as described above.   The cogeneration system according to any one of claims 1 to 4, wherein the heat medium heating and circulation means is configured to circulate through the heat medium circulation path using hot water in a bathtub as the heat consuming unit as a heat medium. system.   The heat medium heating and circulating means is configured to circulate the heat medium through the heat medium circulation path via a heat consumption terminal as the heat consumption unit. Cogeneration system.   The recovery heat quantity acquisition means is configured by a recovery heat quantity measurement means that measures heat quantity recovered by the heat recovery means or heat quantity related information for obtaining the heat quantity. The described cogeneration system.   The operation control means is a continuous operation mode in which the cogeneration device is operated over the entire time period of the operation cycle, an intermittent operation mode in which the cogeneration device is operated in a part of the operation cycle, and the entire operation cycle. The time-series predicted load power data, the time-series predicted load heat amount data, and the time-series predicted recovered heat amount data from at least two of the standby modes for stopping the heat and power supply device over time. The cogeneration system according to any one of claims 1 to 7, wherein the cogeneration system is configured to determine the operating condition by selecting a driving merit obtained based on the above.

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