JP7345338B2 - Combined heat and power system - Google Patents

Description

The present invention is directed to a power generation section that operates by supplying fuel gas, a closed hot water storage tank that stores hot water, and an exhaust heat recovery heat exchange section that recovers waste heat of the power generation section, and the hot water storage tank a circulation path for flowing hot water that connects the bottom and top of the hot water storage tank; a circulation pump that circulates hot water through the circulation path in a form that returns the hot water taken out from the bottom of the hot water storage tank to the top of the hot water storage tank; and an operation control system. A department has been established,
The operation control unit controls the temperature of the hot water supplied to the upper part of the hot water tank through the circulation path to reach a target temperature in order to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is in operation. The present invention relates to a combined heat and power supply system configured to perform an exhaust heat recovery type hot water storage process that controls the operation of the circulation pump by adjusting the circulating amount of hot water flowing through the circulation path.

Such combined heat and power generation systems are installed in ordinary homes, etc., and store hot water by supplying electric power generated in a power generation section to an electrical load, and recovering waste heat from the power generation section to heat hot water in a hot water storage tank. The hot water in the tank can be supplied to hot water consumption parts such as hot water taps.
Incidentally, the power generation section includes a generator driven by a fuel cell or an engine.

As a conventional example of such a combined heat and power system, an antifreeze heater is provided to heat the hot water flowing through the circulation path, and the operation control section performs antifreeze prevention measures such as when the outside temperature drops below the set temperature when the power generation section is stopped. Some devices are configured to perform an antifreeze operation in which when operating conditions are met, an antifreeze heater and a circulation pump are activated to heat hot water flowing through a circulation path (for example, see Patent Document 1). .

Incidentally, in Patent Document 1, a water heater that heats hot water dispensed from a hot water storage tank is provided, and when the temperature of the hot water dispensed from the hot water storage tank is low, etc., it is possible to heat the hot water with the water heater. It is configured so that it can be done.
In addition, in order to operate the antifreeze heater and circulation pump to perform antifreeze operation when the power generation unit is stopped, the antifreeze heater and circulation pump must be configured so that they can be driven by an external power source such as a commercial power source. I will do it.

Patent No. 4838654

In conventional combined heat and power systems, for example, when the power generation unit and water heater are operated using city gas as fuel gas, the power generation unit may If fuel gas is not supplied, such as when both the power generation section and the water heater become inoperable, both the power generation section and the water heater become inoperable, and the heated hot water is transferred to the hot water consumption section. There was a risk that the supply would not be possible, and improvements were desired.

Therefore, the antifreeze heater and the circulation pump are driven by an external power source such as a commercial power source, and the circulation pump is operated in the same driving state (drive output) as when executing the exhaust heat recovery type hot water storage process. Therefore, it is conceivable to configure the system so that hot water heated by an antifreeze heater is stored in a hot water storage tank.
By the way, for the circulation pump, it is possible to set the same drive state (drive output) as when executing the exhaust heat recovery type hot water storage process, for example, to set the drive state (drive output) where the circulation pump has high drive efficiency. It will be done.
However, this configuration was not convenient to use.

In other words, since the antifreeze heater has a small heat capacity (amount of heating), the temperature rise when the hot water taken out from the bottom of the hot water storage tank passes once through the installation location of the antifreeze heater is, for example, 5. Because the temperature is quite low, about ℃, the time required to heat the entire hot water tank to a state where temperature stratification is formed at the target temperature (to boil the hot water tank) is, for example, 20 hours in winter. This will take a considerable amount of time.

Moreover, the temperature of the hot water stored in the hot water storage tank will drop due to heat radiation over time, so check the temperature of the hot water at appropriate intervals and, if the temperature of the hot water has decreased, The pump and anti-freeze heater are activated to store hot water as a heat-retaining operation, but when this type of hot-water storage operation is performed as a heat-retaining operation, the hot water stored in the hot water storage tank cannot be dispensed. becomes.

In other words, if hot water is dispensed during hot water storage operation as a heat retention operation, water will be supplied to the bottom of the hot water storage tank as hot water is dispensed, and the temperature of the supplied hot water will rise by approximately 55°C by the antifreeze heater. As a result, hot water whose temperature has been raised by about 5 degrees Celsius (hot water at a temperature much lower than the target temperature) is supplied to the upper part of the hot water storage tank, resulting in a state in which the temperature stratification of the hot water in the storage tank is disturbed. Therefore, when performing hot water storage operation as heat retention operation, hot water cannot be tapped.

This kind of problem occurs when a portion of the hot water in the hot water storage tank is consumed when the entire hot water in the hot water storage tank is heated to the target temperature, and the circulation pump and freezing heater are activated to stop the hot water storage operation. The same thing will happen when you do.

Therefore, when configuring the circulation pump to operate in the same drive state (drive output) as when executing the exhaust heat recovery type hot water storage process and store hot water heated by the antifreeze heater in the hot water storage tank, For example, after heating the entire hot water in the hot water storage tank to a state where temperature stratification is formed at the target temperature (boiling up the hot water storage tank), for example, once the hot water is dispensed, the hot water storage operation as a heat retention operation is not performed. It is necessary to make sure that all the hot water in the hot water storage tank is used up, and when a hot water storage operation is started as a heat retention operation, hot water cannot be dispensed until the hot water storage operation is finished, which is inconvenient for use.
Moreover, when all the hot water in the hot water storage tank is used up, the entire hot water in the hot water storage tank will be heated to a state where temperature stratification is formed at the target temperature (the hot water storage tank will be boiled), but the time for this will be, for example, It takes a considerable amount of time, such as 20 hours in winter, and is not convenient to use.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to be able to store hot water in a hot water tank in a state where temperature stratification is formed in a state where fuel gas is not supplied, and also to enable hot water to be stored in a hot water storage tank even during hot water storage operation. The point is that it provides a combined heat and power system that can produce hot water.

The combined heat and power generation system of the present invention includes a power generation section that operates by supplying fuel gas, a closed hot water storage tank that stores hot water, and an exhaust heat recovery heat exchange section that recovers waste heat from the power generation section. , a circulation path for flowing hot water that connects the bottom and the top of the hot water storage tank, and a circulation pump that circulates hot water through the circulation path, the hot water taken out from the bottom of the hot water storage tank being returned to the top of the hot water storage tank. and an operation control section,
The operation control unit controls the temperature of the hot water supplied to the upper part of the hot water tank through the circulation path to reach a target temperature in order to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is in operation. A combined heat and power generation system configured to perform an exhaust heat recovery type hot water storage process that controls the operation of the circulation pump by adjusting the circulating amount of hot water flowing through the circulation path, the characteristic configuration of which is as follows:
An antifreeze heater that heats hot water flowing through the circulation path and the circulation pump are provided in a state where they are driven by an external power source,
The operation control unit operates the antifreeze heater to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is stopped, and supplies water to the upper part of the hot water storage tank through the circulation path. The circulating pump adjusts the circulating amount of hot water flowing through the circulation path to be smaller than the circulating amount of hot water in the exhaust heat recovery hot water storage process so that the temperature of the hot water reaches the target temperature. The heater is configured to perform a heat recovery hot water storage process to control the operation of the heater .
A temperature sensor is provided to detect the temperature of hot water taken out from the bottom of the hot water storage tank,
The operation control unit sets the target temperature based on the detection information of the temperature sensor, the temperature difference between the temperature of the hot water taken out from the bottom of the hot water storage tank and the target temperature, and the heating of the antifreeze heater. temperature difference flow rate relationship information indicating a relationship between the target flow rate of hot water flowing through the circulation path and a drive for driving the circulation pump to bring the target flow rate and hot water flowing through the circulation path to the target flow rate; The present invention is configured to control the operation of the circulation pump based on flow rate drive condition relationship information indicating a relationship with conditions.

That is, by executing the heater heat recovery type hot water storage process, the operation control means can thermally stratify the hot water in the hot water storage tank at the target temperature even in a stopped state where the power generation section is stopped due to no fuel gas being supplied. This means that hot water can be stored appropriately in a state where it will form.

In other words, the anti-freeze heater, which is installed to prevent freezing and is driven by an external power source such as a commercial power source, has a small heat capacity (heating amount), but it is used to circulate hot water through the circulation path. Temperature stratification is created by adjusting the amount of hot water to be less than the amount of hot water circulating in the hot water storage process with exhaust heat recovery so that the temperature of the hot water supplied to the upper part of the hot water storage tank through the circulation path reaches the target temperature. Under this condition, hot water can be appropriately stored in the hot water tank.

In this heater heat recovery type hot water storage process, the temperature of the hot water supplied to the upper part of the hot water storage tank through the circulation path is the target temperature, so the hot water is not discharged during the hot water storage operation for boiling or keeping warm. Also, since hot water at the target temperature is supplied to the upper part of the hot water storage tank and the temperature stratification is not disturbed, hot water can be dispensed even during hot water storage operation.

In short, according to the characteristic configuration of the combined heat and power system of the present invention, hot water can be stored in the hot water storage tank in a state where temperature stratification is formed in a state where fuel gas is not supplied, and hot water can be discharged even during hot water storage operation.

In addition, the operation control unit determines the driving conditions of the circulation pump according to the detection information of the temperature sensor that detects the temperature of the hot water taken out from the bottom of the hot water storage tank, based on the temperature difference flow rate related information and the flow rate drive condition related information. (drive output and drive speed) and operate the circulation pump under the determined drive conditions, hot water at or close to the target temperature is supplied immediately after heater heat recovery type hot water storage processing is started. This means that the water can be supplied to the upper part of the hot water storage tank.

In other words, compared to the case where the temperature of the hot water heated by the antifreeze heater is detected and the driving conditions of the circulation pump are set based on the difference between the detected temperature and the target temperature, the temperature difference flow rate is Based on the related information and the flow rate drive condition related information, the drive conditions (drive output and drive speed) of the circulation pump are determined according to the detection information of a temperature sensor that detects the temperature of hot water taken out from the bottom of the hot water storage tank. By doing this, the driving conditions of the circulation pump can be quickly adjusted to the driving conditions that bring the temperature of the hot water heated by the antifreeze heater to the target temperature, so the target temperature can be reached immediately after starting heater heat recovery type hot water storage processing. Hot water at the temperature or at a temperature close to the target temperature can be supplied to the upper part of the hot water storage tank.

In short, according to the characteristic configuration of the combined heat and power system of the present invention, hot water at the target temperature can be supplied to the upper part of the hot water storage tank immediately after starting the heater heat recovery type hot water storage process.

A further characteristic configuration of the combined heat and power system of the present invention is that when the anti-freeze operation condition is satisfied when the power generation unit is stopped and the heater heat recovery type hot water storage process is not executed, The present invention is configured to execute an antifreeze operation process in which the antifreeze heater and the circulation pump are operated.

That is, when the operation control unit is in a stopped state of the power generation unit and a state in which the heater heat recovery type hot water storage process is not executed, when the antifreeze operation conditions are satisfied, the operation control unit performs the antifreeze operation process to operate the antifreeze heater and the circulation pump. will be executed.
The anti-freezing operation conditions include conditions such as the outside temperature falling below the set temperature or the temperature of the pipe line forming the circulation path falling below the set temperature.

That is, in the antifreeze operation process, the antifreeze heater and the circulation pump are operated to raise the temperature of the hot water flowing through the circulation path, thereby appropriately preventing freezing of the hot water in the circulation path.

In short, according to the further characteristic configuration of the combined heat and power generation system of the present invention, freezing of hot water in the circulation path can be appropriately prevented.

A further characteristic configuration of the combined heat and power system of the present invention is that the operation command unit for the operation control unit is configured to instruct execution of the heater heat recovery type hot water storage process,
The operation control unit is configured to execute the heater heat recovery type hot water storage process when the operation command unit issues a command to execute the heater heat recovery type hot water storage process while the power generation unit is in a stopped state. It is in the point where it is.

That is, when the power generation section is in a stopped state, if the operation command section for the operation control section instructs execution of the heater heat recovery type hot water storage process, the operation control section will execute the heater heat recovery type hot water storage process.

In this way, when the power generation unit is stopped and the operation command unit instructs execution of heater heat recovery type hot water storage processing, the operation control unit executes the heater heat recovery type hot water storage processing, which is unnecessary. The heater heat recovery type hot water storage process can be executed only when necessary while avoiding execution of the heater heat recovery type hot water storage process.

In short, according to a further characteristic configuration of the combined heat and power generation system of the present invention, the heater heat recovery type hot water storage process can be appropriately executed only when necessary.

A further characteristic configuration of the combined heat and power system of the present invention is that when the total amount of hot water in the hot water storage tank reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit starts the heater heat recovery type hot water storage process. Subsequently, in order to heat the hot water in the hot water storage tank to a higher temperature than the target temperature, the heater heat recovery type high temperature heating treatment is performed in which the antifreeze heater and the circulation pump are continuously operated. It is in the point where it is.

That is, when the total amount of hot water in the hot water storage tank reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit heats the hot water in the hot water storage tank to a higher temperature than the target temperature following the heater heat recovery type hot water storage process. In order to achieve this, a heater heat recovery type high-temperature heating process is performed in which the antifreeze heater and circulation pump are continuously operated, so hot water with a temperature higher than the target temperature is stored in the hot water tank. This will increase the amount of heat stored in the area.

Therefore, in an emergency when both the power generation unit and the water heater are inoperable due to a lack of fuel gas supply, hot water stored in the hot water storage tank can be used to increase the amount of hot water supplied to the hot water consumption unit. be able to.

In short, according to a further characteristic configuration of the combined heat and power system of the present invention, it is possible to increase the amount of hot water supplied to the hot water consumption section using hot water stored in the hot water storage tank.

A further feature of the combined heat and power system of the present invention is that the operation control unit is configured to stop the heater heat recovery high-temperature heating treatment when the entire amount of hot water in the hot water storage tank reaches a set upper limit temperature. At the point.

In other words, the operation control unit stops the heater heat recovery type high-temperature heating process when the total amount of hot water in the hot water storage tank reaches the set upper limit temperature, thereby avoiding the temperature of hot water in the hot water storage tank from becoming extremely high. can.

In short, according to the further characteristic configuration of the combined heat and power system of the present invention, it is possible to prevent the temperature of the hot water in the hot water tank from becoming extremely high.

A further feature of the combined heat and power system of the present invention is that the operation control unit is configured to stop the heater heat recovery high-temperature heating treatment when the rate of increase in the temperature of hot water in the hot water storage tank becomes equal to or less than a set rate. It is in the point that it is.

In other words, the operation control unit will stop the heater heat recovery type high-temperature heating treatment when the rate of increase in the temperature of hot water in the hot water storage tank falls below the set rate. By avoiding operating the freeze prevention heater, wasteful power consumption can be suppressed.

In other words, the heating efficiency of hot water by the antifreeze heater decreases as the temperature of hot water increases, so if the rate of increase in the temperature of hot water in the hot water storage tank falls below the set rate, the heater heat recovery high temperature By stopping the heat treatment, it is possible to avoid operating the antifreeze heater in a state where the heating efficiency of the antifreeze heater has decreased, thereby suppressing wasteful power consumption.

In short, according to the further characteristic configuration of the combined heat and power generation system of the present invention, wasteful power consumption can be suppressed.
Another combined heat and power system of the present invention operates through a power generation section that operates by supplying fuel gas, a closed hot water storage tank that stores hot water, and an exhaust heat recovery heat exchange section that recovers waste heat from the power generation section. A circulating path for flowing hot water connects the bottom and top of the hot water storage tank, and a form in which hot water taken out from the bottom of the hot water storage tank is returned to the top of the hot water storage tank, and the hot water is circulated through the circulation path. A circulation pump and an operation control section are provided,
The operation control unit controls the temperature of the hot water supplied to the upper part of the hot water tank through the circulation path to reach a target temperature in order to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is in operation. A combined heat and power generation system configured to perform exhaust heat recovery type hot water storage processing that controls the operation of the circulation pump in a form that adjusts the amount of hot water circulating through the circulation path, the characteristic configuration of which is as follows:
An antifreeze heater that heats hot water flowing through the circulation path and the circulation pump are provided in a state where they are driven by an external power source,
The operation control unit operates the antifreeze heater to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is stopped, and supplies water to the upper part of the hot water storage tank through the circulation path. The circulation pump adjusts the amount of hot water circulating through the circulation path to be smaller than the amount of hot water circulating in the exhaust heat recovery hot water storage process so that the temperature of the hot water reaches the target temperature. The heater is configured to perform a heat recovery hot water storage process to control the operation of the heater.
When the total amount of hot water in the hot water storage tank reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit controls the hot water in the hot water storage tank to be lower than the target temperature following the heater heat recovery type hot water storage process. In order to heat to a high temperature, the antifreeze heater and the circulation pump are continuously operated to perform a heater heat recovery type high temperature heating process.
That is, by executing the heater heat recovery type hot water storage process, the operation control means can thermally stratify the hot water in the hot water storage tank at the target temperature even in a stopped state where the power generation section is stopped due to no fuel gas being supplied. This means that hot water can be stored appropriately in a state where it will form.
In other words, the anti-freeze heater, which is installed to prevent freezing and is driven by an external power source such as a commercial power source, has a small heat capacity (heating amount), but it is used to circulate hot water through the circulation path. Temperature stratification is created by adjusting the amount of hot water to be less than the amount of hot water circulating in the hot water storage process with exhaust heat recovery so that the temperature of the hot water supplied to the upper part of the hot water storage tank through the circulation path reaches the target temperature. Under this condition, hot water can be appropriately stored in the hot water tank.
In this heater heat recovery type hot water storage process, the temperature of the hot water supplied to the upper part of the hot water storage tank through the circulation path is the target temperature, so the hot water is not discharged during the hot water storage operation for boiling or keeping warm. Also, since hot water at the target temperature is supplied to the upper part of the hot water storage tank and the temperature stratification is not disturbed, hot water can be dispensed even during hot water storage operation.
In short, according to the characteristic configuration of the combined heat and power system of the present invention, hot water can be stored in the hot water storage tank in a state where temperature stratification is formed in a state where fuel gas is not supplied, and hot water can be discharged even during hot water storage operation.
In addition, when the total amount of hot water in the hot water storage tank reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit heats the hot water in the hot water storage tank to a higher temperature than the target temperature following the heater heat recovery type hot water storage process. In order to achieve this, a heater heat recovery type high-temperature heating process is performed in which the antifreeze heater and circulation pump are continuously operated, so hot water with a temperature higher than the target temperature is stored in the hot water tank. This will increase the amount of heat stored in the area.
Therefore, in an emergency when both the power generation unit and the water heater are inoperable due to a lack of fuel gas supply, hot water stored in the hot water storage tank can be used to increase the amount of hot water supplied to the hot water consumption unit. be able to.
In short, according to the characteristic configuration of the combined heat and power system of the present invention, it is possible to increase the amount of hot water supplied to the hot water consumption section using hot water stored in the hot water storage tank.

FIG. 1 is a schematic configuration diagram of a combined heat and power generation system. It is a graph showing temperature difference flow rate relationship information. It is a graph showing flow rate drive condition related information. 5 is a flowchart illustrating control operations of additional embodiments.

[Embodiment]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a combined heat and power generation system of the present invention will be described based on the drawings.
(Overall configuration of combined heat and power system)
As shown in FIG. 1, a commercial power transmission line 4A from a commercial power source 4 that supplies commercial power is connected to an indoor distribution board 3 to which power supply lines 2 for a plurality of electrical loads 1 are connected. A power transmission line 5 from the fuel cell power generation module M is connected to an indoor distribution board 3.

The power transmission line 5 from the fuel cell power generation module M is equipped with an inverter or the like for grid connection that adjusts the power generated by the fuel cell power generation module M to the same voltage and frequency as the power supplied from the commercial power source 4. A power conversion unit 6 is equipped.
Therefore, the configuration is such that commercial power from the commercial power source 4 and power generated by the fuel cell power generation module M are supplied to the plurality of electrical loads 1.

A system casing K is provided, and the system casing K includes a fuel cell power generation module M, a closed hot water storage tank 8 for storing hot water, and the heat of the exhaust gas discharged from the fuel cell power generation module M is recovered as waste heat. The hot water circulation path 9 connects the bottom and top of the hot water storage tank 8 through the exhaust heat recovery heat exchange unit N, the hot water circulation path 9 that connects the bottom and the top of the hot water storage tank 8, and the hot water taken out from the bottom of the hot water storage tank 8. A circulation pump 10 that circulates hot water through a circulation path 9 and an operation control unit H are housed in a form that returns the hot water to the upper part of the hot water storage tank 8 .

Incidentally, although not shown, a storage battery is provided that stores the power from the commercial power source 4 and the power from the fuel cell power generation module M, and the power from this storage battery is used for various control system devices such as the operation control unit H. is configured to be supplied to
Further, a remote control R is provided as an operation command section that commands various information to the operation control section H.

The operation control unit H sets the temperature of hot water supplied to the upper part of the hot water tank 8 through the circulation path 9 to a target temperature in order to store hot water in a state where temperature stratification is formed in the hot water storage tank 8 when the fuel cell power generation module M is in operation. (for example, 65° C.), and is configured to execute an exhaust heat recovery type hot water storage process that controls the operation of the circulation pump 10 by adjusting the amount of hot water circulating through the circulation path 9 so that the temperature is 65° C. (for example, 65° C.).
Incidentally, the above target temperature may be automatically set to a different temperature depending on the season, such as summer, winter, or intermediate season, or the temperature may be set to the user's preference using the remote control R. You may.

Therefore, the hot water stored in the hot water storage tank 8 is configured to be able to be delivered to a hot water consumption point such as a hot water faucet through a hot water outlet 11 connected to the upper part of the hot water storage tank 8.
Incidentally, when the hot water stored in the hot water storage tank 8 is dispensed, water is supplied from a water supply source such as a water supply through the water supply channel 12 connected to the lower part of the hot water storage tank 8.

(Details of circulation route)
The circulation path 9 includes an outgoing path 9a that connects the bottom of the hot water storage tank 8 and the exhaust heat recovery heat exchange section N, and a return path 9b that connects the exhaust heat recovery heat exchange section N and the top of the hot water storage tank 8.
The outgoing path 9a includes, along the flow direction of the hot water, the above-mentioned circulation pump 10, a freeze prevention heater 13 that heats the hot water flowing through the circulation path 9, and a radiator 14 that cools the hot water flowing through the circulation path 9. It is provided.
The radiator 14 is provided to cool the hot water circulating in the circulation path 9 when hot water at a target temperature (for example, 65° C.) is stored throughout the hot water storage tank 8 (in a boiling state). ing.

Incidentally, although not shown, the pump drive circuit 10A of the circulation pump 10 and the heater drive circuit 13A of the antifreeze heater 13 are supplied with commercial power from the commercial power source 4 or power from the power converter 6. It is composed of
In other words, the circulation pump 10 and the antifreeze heater 13 are driven by the power of the commercial power source 4 as an external power source when the combined heat and power system is stopped, and when the combined heat and power system is generating electricity, It is provided in a state where it is driven by electric power from the converter 6.

A cold water sensor 15 serving as a temperature sensor for detecting the temperature of hot water taken out from the bottom of the hot water tank 8 is provided at a location on the upstream side of the circulation pump 10 in the outgoing path 9a.
Further, the return path 9b is provided with a hot water side sensor 16 as a temperature sensor that detects the temperature of hot water heated in the exhaust heat recovery heat exchange section N.

Further, a bypass path 9c is provided to connect a flow path portion corresponding to between the cold water side sensor 15 and the circulation pump 10 in the outgoing path 9a and the incoming path 9b.
A three-way switching type bypass valve 17 switches between a hot water tank flow state in which the hot water flowing through the return path 9b flows to the upper part of the hot water storage tank 8 and a bypass flow state in which the hot water flowing in the return path 9b flows into the bypass path 9c. It is provided.
When the antifreeze heater 13 is activated, the flow state can be switched to a bypass flow state.

(Details of hot water configuration)
The hot water outlet path 11 is provided with a mixing valve 18 that mixes hot water (cold water) supplied from a branch path 12A branched from the water supply channel 12 and hot water (warm water) flowing through the hot water outlet path 11. It is being
For example, in order to dispense hot water at a target hot water supply temperature (for example, 40°C, etc.) commanded by the remote controller R, hot water (cold water) from the branch path 12A and hot water (warm water) flowing through the hot water tap path 11 are combined. are configured so that they can be mixed by a mixing valve 18.

An instantaneous water heater D that operates using fuel gas such as city gas is provided to process hot water from the outlet path 11 and dispense the hot water.
Further, a cold water channel 19 is provided for supplying hot water (cold water) from the branch channel 12A to a location on the downstream side of the mixing valve 18 in the outlet channel 11, and an on-off valve 19A for opening and closing this cold water channel 19 is provided.
Then, for example, in a case where the hot water in the hot water tank 8 cannot be used due to sterilization measures for the hot water tank 8, etc., the cold water channel 19 is opened and the hot water (cold water) from the cold water channel 19 is supplied to the water heater D and heated. As a result, hot water at a target hot water supply temperature (for example, 40° C., etc.) can be dispensed.

(Details of fuel cell module)
The fuel cell type power generation module M includes a reforming processing section 21 to which fuel gas such as city gas is supplied through a fuel gas supply path 20, a cell stack 22 including a plurality of solid oxide fuel cells, and a high temperature container 23. It is configured to be stored inside the.

The reforming processing unit 21 is configured to subject fuel gas to a steam reforming process to generate reformed gas containing a large amount of hydrogen, and is configured such that the generated reformed gas is supplied to the cell stack 22. ing.
Incidentally, water vapor is supplied to the reforming processing section 21 in addition to fuel gas, but since its configuration is well known, detailed explanation will be omitted in this embodiment.

Although not shown, air (oxygen-containing gas) is supplied into the high temperature container 23.
The cell stack 22 is configured to generate electricity by passing the reformed gas through the fuel electrode and passing the air (oxygen-containing gas) supplied into the high temperature container 23 through the oxygen electrode. has been done.

In addition, the reformed gas that has passed through the fuel electrode is combusted using the air (oxygen-containing gas) that has passed through the oxygen electrode or the air (oxygen-containing gas) that has been supplied to the inside of the high-temperature container 23. , and is configured to heat the reforming processing section 21 with the combustion heat.
Furthermore, an exhaust gas passage 24 for discharging exhaust gas obtained by burning the reformed gas from the high-temperature container 23 is provided so as to pass through the aforementioned exhaust heat recovery heat exchange section N. In other words, the exhaust heat recovery heat exchange section N is configured to recover the exhaust heat of the exhaust gas produced by burning the reformed gas after passing through the fuel electrode.

Further, the fuel gas supply passage 20 is provided with a fuel gas supply valve 25 that opens and closes the fuel gas supply passage 20 to intermittent the supply of fuel gas, and a pressure sensor 26 that detects the supply pressure of the fuel gas. There is.

(Summary of operation control of operation control unit)
When the operation control unit H receives an operation command from the remote controller R, it opens the fuel gas supply valve 25 and executes an operation process to operate the fuel cell power generation module M, and when the operation control unit H receives an operation stop command from the remote controller R. Then, the fuel gas supply valve 25 is closed and a stop process is executed to stop the fuel cell power generation module M.
The operation control unit H is configured to execute the above-mentioned exhaust heat recovery type hot water storage process during execution of the operation process.

In addition, when the supply pressure of fuel gas detected by the pressure sensor 26 becomes lower than the set pressure, the operation control unit H controls the fuel cell power generation module M even if an operation command is issued from the remote control R. A stop process will be executed to stop the process.
In other words, if fuel gas at a pressure higher than the set pressure is not supplied through the fuel gas supply path 20 due to the occurrence of an earthquake or the like, the fuel cell type power generation module M is configured to be maintained in a stopped state.

Then, when the execution of the heater heat recovery type hot water storage process is commanded by the remote controller R during the execution of the stop process of stopping the fuel cell type power generation module M, the operation control unit H controls the freezing prevention heater 13 and the circulation pump. 10 to execute heater heat recovery type hot water storage processing.

In addition, the operation control unit H operates the antifreeze heater 13 and the circulation pump 10 when the antifreeze condition is satisfied when the fuel cell power generation module M is stopped and the heater heat recovery type hot water storage process is not executed. The system is configured to execute anti-freezing operation processing to prevent freezing.

(Details of antifreeze operation processing)
In this embodiment, an outside air temperature sensor (not shown) is provided to detect the outside air temperature, and when the outside air temperature detected by the outside air temperature sensor becomes less than a set temperature (for example, 3°C), the antifreeze conditions are activated. When the condition is satisfied, the operation control unit H is configured to execute an antifreeze operation process in which the antifreeze heater 13 and the circulation pump 10 are operated.

Specifically, the heater drive circuit 13A is operated to drive the antifreeze heater 13 at the rated output, and the circulation pump 10 is driven at a drive output (pump output) of about 60% of the rated output. , and is configured to operate the pump drive circuit 10A.

In addition, in the antifreeze operation process, the bypass valve 17 is switched to the bypass flow state, and hot water flowing through the circulation path 9 is caused to flow through the bypass path 9c.

(Details of heater heat recovery type hot water storage processing)
When the fuel cell type power generation module M is in a stopped state, when execution of the heater heat recovery type hot water storage process is commanded by the remote control R, the operation control unit H causes the hot water storage tank 8 to store hot water in a state where temperature stratification is formed. The antifreeze heater 13 is activated, and the amount of hot water circulating through the circulation path 9 is controlled so that the temperature of the hot water supplied to the upper part of the hot water storage tank 8 through the circulation path 9 reaches the target temperature (for example, 65° C.). It is configured to execute the heater heat recovery hot water storage process that controls the operation of the circulation pump 10 in such a manner that the hot water circulation amount is adjusted to be smaller than the hot water circulation amount in the exhaust heat recovery hot water storage process.

Specifically, the heater drive circuit 13A is operated to drive the antifreeze heater 13 at the rated output, and the drive output (pump output) of the circulation pump 10 is adjusted so that the amount of hot water circulating through the circulation path 9 is adjusted. The pump drive circuit 10A is configured to operate so that the temperature of the hot water supplied to the upper part of the hot water storage tank 8 becomes a circulating amount of hot water at a target temperature (for example, 65° C.).

In this embodiment, the operation control unit H determines the target drive output (target pump output) of the circulation pump 10 based on the detection information of the cold water side sensor 15, the temperature difference flow rate relationship information, and the flow rate drive condition relationship information. The pump drive circuit 10A is operated so that the drive output (pump output) of the circulation pump 10 becomes the target drive output (target pump output), and the temperature of the hot water detected by the hot water side sensor 16 is The target drive output (target pump output) is configured to be corrected so as to reach the target temperature (for example, 65° C.).

To explain, the temperature difference flow rate relationship information, as shown in FIG. This is information indicating the relationship between the target flow rate of hot water flowing through the circulation path 9 in order to reach the target temperature (for example, 65° C.) by heating the water.
For example, if the temperature detected by the cold water sensor 15 is 5° C. and the target temperature is 65° C., the temperature difference will be 60° C., and the target flow rate will be 71.7 cc/min.

Further, as shown in FIG. 3, the flow rate drive condition related information includes the target flow rate determined by the temperature difference flow rate related information and the drive output for driving the circulation pump 10 in order to achieve the target flow rate of hot water flowing through the circulation path 9. (pump output).
Incidentally, in this embodiment, the drive condition of the circulation pump 10 determined from the flow rate drive condition related information is the pump output (drive output) as a ratio when the rated output of the circulation pump 10 is set to 100% pump output. However, the drive speed (drive rotational speed) of the circulation pump 10 may be determined as the drive condition of the circulation pump 10 determined from the flow rate drive condition related information.

For example, when the target flow rate determined from the temperature difference flow rate relationship information is 71.7 cc/min, in this embodiment, the pump output is determined as 47.5%, which means that the pump output is 47.7 cc/min. The pump drive circuit 10A will be activated to achieve 5%.

In this way, the operation control unit H determines the target drive output (target pump output) of the circulation pump 10 based on the detection information of the cold water side sensor 15, the temperature difference flow rate relationship information, and the flow rate drive condition relationship information. If the pump drive circuit 10A is operated so that the drive output (pump output) of the circulation pump 10 becomes the target drive output (target pump output), the temperature of the hot water supplied to the hot water tank 8 becomes the target temperature (e.g. , 65°C), but if the temperature of the hot water supplied to the hot water storage tank 8 deviates from the target temperature (for example, 65°C) due to a control error, the operation control unit H The target drive output (target pump output) is corrected so that the temperature of hot water detected by the hot water side sensor 16 becomes the target temperature (for example, 65° C.).

Incidentally, when performing exhaust heat recovery type hot water storage processing, the operation control unit H controls the circulation pump so that the temperature of the hot water detected by the hot water side sensor 16 reaches the target temperature (for example, 65° C.). Control is executed to adjust the drive output (pump output) of 10.
The drive output (pump output) of the circulation pump 10 required when performing the heater heat recovery type hot water storage process is determined from the drive output (pump output) of the circulation pump 10 required when performing the exhaust heat recovery type hot water storage process. will also be smaller.

The operation control unit H determines that when the temperature detected by the cold water side sensor 15 reaches the target temperature (for example, 65°C), the entire amount of hot water in the hot water tank 8 has reached the target temperature (for example, 65°C). When detected, the heater heat recovery type hot water storage process is stopped.
By the way, by providing a temperature sensor that detects the temperature of the hot water at the bottom side of the hot water storage tank 8, and this temperature sensor detecting the target temperature (for example, 65°C), the total amount of hot water in the hot water storage tank 8 reaches the target temperature. It may also be possible to detect what has happened.

In addition, after stopping the heater heat recovery type hot water storage process, the operation control unit H controls the hot water storage tank by detecting the flow of hot water with a flow sensor (not shown) provided in the hot water outlet path 11 after stopping the heater heat recovery type hot water storage process. When it is determined that hot water No. 8 has been consumed, the heater heat recovery hot water storage process is restarted to maintain the state in which the entire amount of hot water in hot water storage tank 8 reaches the target temperature (for example, 65° C.).

Furthermore, after stopping the heater heat recovery type hot water storage process, the operation control unit H controls the circulation pump 1 When it is determined that the temperature detected by the cold water side sensor 15 is lower than the target temperature (e.g. 65°C) by the set temperature (for example, 5°C), the heater heat recovery type hot water storage process is restarted. , a heat retention operation is performed in which the entire amount of hot water in the hot water storage tank 8 is maintained at the target temperature (for example, 65° C.).

(Additional Embodiments)
In the embodiment described above, the operation control unit H determines that the temperature detected by the cold water side sensor 15 reaches the target temperature (for example, 65° C.), so that the entire amount of hot water in the hot water tank 8 has reached the target temperature. Although the embodiment has been exemplified in which the heater heat recovery type hot water storage process is stopped when detected, it may be configured as described below.

That is, in this additional embodiment, when the entire (total amount) of hot water in the hot water storage tank 8 reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit H, following the heater heat recovery type hot water storage process, In order to heat the hot water in the hot water storage tank 8 to a higher temperature than the target temperature, it is configured to perform a heater heat recovery type high temperature heating process in which the antifreeze heater 13 and the circulation pump 10 are continuously operated.

In this additional embodiment, the target drive output (target pump output) of the circulation pump 10 for the heater heat recovery type high-temperature heating treatment is set to, for example, a set output with which the drive efficiency of the circulation pump 10 is high. It is configured to gradually increase the temperature of hot water.
Incidentally, when gradually increasing the temperature of hot water in the hot water storage tank 8 using the heater heat recovery type high-temperature heating process, the target drive output (target drive output) of the circulation pump 10 suitable for raising the set temperature (for example, 10° C.) from the current temperature is determined. The target pump output) may be determined based on the detection information of the cold water side sensor 15, the temperature difference flow rate relationship information, and the flow rate drive condition relationship information.
In addition, the final target temperature (for example, 90°C) to be heated in the heater heat recovery type high-temperature heating treatment is determined, and the target drive output (target pump output) of the circulation pump 10 for the heater heat recovery type high-temperature heating treatment is set on the cold water side. It is also conceivable to carry out the calculation based on the detection information of the sensor 15, the temperature difference flow rate relationship information, and the flow rate drive condition relationship information.

Further, the operation control unit H is configured to stop the heater heat recovery type high-temperature heating process when the entire amount of hot water in the hot water storage tank 8 reaches a set upper limit temperature (for example, 90° C.).
In other words, when the detected temperature of the cold water side sensor 15 reaches the set upper limit temperature (for example, 90°C), it is detected that the entire amount of hot water in the hot water storage tank 8 has reached the set upper limit temperature (for example, 90°C). , the heater heat recovery type high-temperature heating process is stopped.
By the way, by providing a temperature sensor that detects the temperature of the hot water at the bottom of the hot water storage tank 8 and detecting the set upper limit temperature (for example, 90°C), the total amount of hot water in the hot water storage tank 8 reaches the set upper limit. It may also be possible to detect that the temperature has reached 90° C., for example.

Note that during the execution of the heater heat recovery type high-temperature heating process, if the cold water side sensor 15 detects a high temperature equal to or higher than the high-temperature error temperature (for example, 95 °C) that is higher than the set upper limit temperature (for example, 90 °C), In order to ensure safety, the operation control unit H is configured to stop the heater heat recovery type high-temperature heating process.

Further, the operation control unit H is configured to stop the heater heat recovery type high-temperature heating process when the rate of increase in the temperature of hot water in the hot water storage tank 8 becomes equal to or less than a set rate.
In other words, the heating efficiency of the hot water by the antifreeze heater 13 decreases as the temperature of the hot water increases, so when the rate of increase in the temperature of the hot water in the hot water storage tank 8 falls below the set rate, the heater heat recovery By stopping the high-temperature heat treatment, the anti-freezing heater 13 is prevented from operating in a state where the heating efficiency of the anti-freezing heater 13 is reduced, thereby suppressing wasteful power consumption. There is.

The rate of increase in the temperature of the hot water in the hot water tank 8 can be detected from the change in temperature detected by the cold water side sensor 15 and the elapsed time.
For example, immediately after the heater heat recovery type hot water storage process is followed by the heater heat recovery type high temperature heating process, the temperature of the cold water side sensor 15 is set until the temperature of the entire hot water (total amount) in the hot water storage tank 8 is raised (heated). The detected temperature will be maintained at the target temperature (for example, 65°C).

After that, when hot water whose temperature has been raised (heated) by the heater heat recovery type high-temperature heating process flows from the bottom of the hot water storage tank 8, the cold water side sensor 15 detects that the heater heat is higher than the target temperature (for example, 65 degrees Celsius). The temperature of the hot water heated in the recovery-type high-temperature heating process (hereinafter referred to as heating temperature) will be detected.
Therefore, by dividing the temperature difference between the heating temperature and the target temperature (e.g. 65°C) by the elapsed time from the target temperature (e.g. 65°C) to the heating temperature, the temperature of the hot water in the hot water tank 8 can be calculated. The rate of increase (time required to raise unit temperature) can be determined.

Note that the heating temperature increases in stages every time the entire amount of hot water in the hot water storage tank 8 is heated, so the heating temperature before the increase is the heating temperature after the increase and the heating temperature before the increase. By dividing by the elapsed time from the temperature to the heating temperature after the increase, the rate of increase in the temperature of the hot water in the hot water tank 8 (the time required to increase the unit temperature) can be determined.

In this way, by performing the heater heat recovery type high temperature heating process following the heater heat recovery type hot water storage process, hot water with a temperature higher than the target temperature is stored in the hot water storage tank 8. As a result, the amount of heat stored in the hot water storage tank 8 increases, and the amount of hot water supplied to the hot water consumption section can be increased using the hot water stored in the hot water storage tank 8.

Next, the control operation of the operation control section H in this additional embodiment will be explained based on the flowchart of FIG. 4.
First, it is determined whether execution of the heater heat recovery type hot water storage process has been commanded by the remote control R (#1), and if it has not been commanded, the process waits until it is commanded.
If it is determined in the process #1 that a command has been issued, the next step is to determine whether the fuel cell power generation module M is in a stopped state, that is, whether the fuel gas supply is stopped. It is determined whether or not (#2), and if the supply of fuel gas has not stopped, the process moves to #1.

If it is determined in the process #2 that the supply of fuel gas is stopped, a heater heat recovery type hot water storage process is executed (#3).
After that, it is determined whether the entire hot water (all amount) in the hot water storage tank 8 is at the target temperature (e.g., 65°C) (#4), and the entire hot water (all amount) is not at the target temperature (e.g., 65° C.). If so, continue the heater heat recovery type hot water storage process.

In the process of #4, if it is determined that the entire amount of hot water in the hot water storage tank 8 is at the target temperature (for example, 65°C), then a heater heat recovery type high-temperature heating process is performed (# 5).
Thereafter, it is determined whether the entire hot water (total amount) in the hot water storage tank 8 is higher than the set upper limit temperature (for example, 90°C or higher) (#6), and the entire hot water (total amount) is higher than the set upper limit temperature (for example, , 90° C. or higher), the operation of the antifreeze heater 13 and the circulation pump 10 is stopped in order to stop the heater heat recovery type high-temperature heating treatment (#8).

If it is determined in the process #6 that the total amount of hot water is not higher than the set upper limit temperature (for example, 90°C or higher), then it is determined whether the rate of increase in the temperature of hot water in the hot water tank 8 is lower than the set speed. If the rate of rise in the temperature of the hot water is less than the set rate, the process moves to step #8 and the antifreeze heater 13 and circulation pump 10 are stopped.

If it is determined in the process #7 that the rate of increase in the temperature of the hot water in the hot water storage tank 8 is not lower than the set rate, the heater heat recovery type high-temperature heating process in #5 is continued.

Incidentally, although the description is omitted in the above flowchart, in this additional embodiment, after the heater heat recovery type high-temperature heating treatment is stopped, a flow sensor (not shown) provided in the outlet path 11 controls the flow of hot water. When it is determined that the hot water in the hot water storage tank 8 has been consumed by detecting the flow, etc., the heater heat recovery type high temperature treatment may be restarted.

Further, after stopping the heater heat recovery type high-temperature heating treatment, the circulation pump 10 is operated every time the elapsed time in which the hot water in the hot water storage tank 8 is not consumed exceeds a set time (for example, 3 hours). When it is determined that the detected temperature of the cold water side sensor 15 is lower than the set start temperature (e.g., 80°C) which is higher than the target temperature (e.g., 65°C) and lower than the set upper limit temperature (e.g., 90°C), the heater The heat recovery type high temperature heating treatment may be restarted.

In addition, during the execution of the heater heat recovery type high-temperature heating process, the flow of hot water is detected by a flow sensor (not shown) provided in the hot water outlet path 11, so that the consumption of hot water in the hot water storage tank 8 is reduced. If it is determined that the heater heat recovery type high-temperature heating process has been started, the execution of the heater heat recovery type high-temperature heating process may be temporarily stopped, and when the hot water in the hot water storage tank 8 has been consumed, the heater heat recovery type high-temperature heating process may be restarted. Even while the hot water in the hot water storage tank 8 is being consumed, the heater heat recovery type high temperature heating treatment may be continued.

[Another embodiment]
Next, other embodiments will be listed.
(1) In the above embodiment, the fuel cell type power generation module M is illustrated as the power generation section, but the power generation section may be implemented in a form in which a gas engine that drives the generator is provided.

(2) In the above embodiment, a fuel cell type power generation module M equipped with a solid oxide fuel cell is illustrated as a fuel cell type power generation unit, but a solid polymer type power generation unit is used as a fuel cell type power generation unit. The present invention may be implemented in a form in which a fuel cell-type power generation unit including a fuel cell is provided.

(3) In the above embodiment, when executing the heater heat recovery type hot water storage process, the antifreeze heater 13 is driven at the rated output, but the output of the antifreeze heater 13 may be increased or decreased. Alternatively, if the output of the antifreeze heater 13 can be increased above the rated output, the antifreeze heater 13 may be driven at the maximum output.

(4) In the above embodiment, when the outside air temperature becomes lower than the set temperature, it is determined that the anti-freeze operation conditions for executing the anti-freeze operation process are satisfied. It may be implemented in such a manner that when the temperature becomes lower than the set temperature, it is determined that the antifreeze operation conditions for executing the antifreeze operation process are satisfied.

Note that the configurations disclosed in the above embodiments (including other embodiments) can be applied in combination with configurations disclosed in other embodiments, as long as there is no contradiction, and this specification The embodiments disclosed in the above are merely examples, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the purpose of the present invention.

4 External power supply 8 Hot water storage tank 9 Circulation path 10 Circulation pump 13 Freeze prevention heater 15 Temperature sensor H Operation control section M Power generation section N Exhaust heat recovery heat exchange section R Operation command section

Claims (7)

The system includes a power generation section that operates by supplying fuel gas, a closed hot water storage tank that stores hot water, and an exhaust heat recovery heat exchange section that recovers waste heat from the power generation section. a circulation path for flowing hot water that connects the hot water storage tank, a circulation pump that circulates hot water through the circulation path in a form that returns the hot water taken out from the bottom of the hot water storage tank to the top of the hot water storage tank, and an operation control unit. is,
The operation control unit controls the temperature of the hot water supplied to the upper part of the hot water tank through the circulation path to reach a target temperature in order to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is in operation. A combined heat and power supply system configured to perform an exhaust heat recovery type hot water storage process that controls the operation of the circulation pump by adjusting the circulating amount of hot water flowing through the circulation path,
An antifreeze heater that heats hot water flowing through the circulation path and the circulation pump are provided in a state where they are driven by an external power source,
The operation control unit operates the antifreeze heater to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is stopped, and supplies water to the upper part of the hot water storage tank through the circulation path. The circulation pump adjusts the amount of hot water circulating through the circulation path to be smaller than the amount of hot water circulating in the exhaust heat recovery hot water storage process so that the temperature of the hot water reaches the target temperature. The heater is configured to perform a heat recovery hot water storage process to control the operation of the heater .
A temperature sensor is provided to detect the temperature of hot water taken out from the bottom of the hot water storage tank,
The operation control unit sets the target temperature based on the detection information of the temperature sensor, the temperature difference between the temperature of hot water taken out from the bottom of the hot water storage tank and the target temperature, and the heating of the antifreeze heater. temperature difference flow rate relationship information indicating a relationship between the target flow rate of hot water flowing through the circulation path and a drive for driving the circulation pump in order to make the target flow rate and the hot water flowing through the circulation path the target flow rate; A combined heat and power generation system configured to control operation of the circulation pump based on flow rate drive condition relationship information indicating a relationship with conditions. The system includes a power generation section that operates by supplying fuel gas, a closed hot water storage tank that stores hot water, and an exhaust heat recovery heat exchange section that recovers waste heat from the power generation section. a circulation path for flowing hot water that connects the hot water storage tank, a circulation pump that circulates hot water through the circulation path in a form that returns the hot water taken out from the bottom of the hot water storage tank to the top of the hot water storage tank, and an operation control unit. is,
The operation control unit controls the temperature of the hot water supplied to the upper part of the hot water tank through the circulation path to reach a target temperature in order to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is in operation. A combined heat and power supply system configured to perform an exhaust heat recovery type hot water storage process that controls the operation of the circulation pump by adjusting the circulating amount of hot water flowing through the circulation path,
An antifreeze heater that heats hot water flowing through the circulation path and the circulation pump are provided in a state where they are driven by an external power source,
The operation control unit operates the antifreeze heater to store hot water in a state where temperature stratification is formed in the hot water storage tank when the power generation unit is stopped, and supplies water to the upper part of the hot water storage tank through the circulation path. The circulation pump adjusts the amount of hot water circulating through the circulation path to be smaller than the amount of hot water circulating in the exhaust heat recovery hot water storage process so that the temperature of the hot water reaches the target temperature. The heater is configured to perform a heat recovery hot water storage process to control the operation of the heater.
When the total amount of hot water in the hot water storage tank reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit controls the hot water in the hot water storage tank to be lower than the target temperature following the heater heat recovery type hot water storage process. A combined heat and power supply system configured to perform a heater heat recovery type high-temperature heating process in which the antifreeze heater and the circulation pump are continuously operated in order to heat the water to a high temperature. When the anti-freeze operation conditions are satisfied when the power generation unit is stopped and the heater heat recovery hot water storage process is not executed, the operation control unit operates the anti-freeze heater and the circulation pump. The combined heat and power system according to claim 1 or 2, wherein the combined heat and power system is configured to perform processing. An operation command unit for the operation control unit is configured to command execution of the heater heat recovery type hot water storage process,
The operation control unit is configured to execute the heater heat recovery type hot water storage process when the operation command unit issues a command to execute the heater heat recovery type hot water storage process while the power generation unit is in a stopped state. The combined heat and power generation system according to any one of claims 1 to 3. When the total amount of hot water in the hot water storage tank reaches the target temperature in the heater heat recovery type hot water storage process, the operation control unit controls the hot water in the hot water storage tank to be lower than the target temperature following the heater heat recovery type hot water storage process. 2. The combined heat and power system according to claim 1 , wherein the combined heat and power system is configured to perform a heater heat recovery type high-temperature heating process in which the antifreeze heater and the circulation pump are continuously operated in order to heat the water to a high temperature. The combined heat and power supply system according to claim 2 or 5, wherein the operation control unit is configured to stop the heater heat recovery type high-temperature heating treatment when the total amount of hot water in the hot water storage tank reaches a set upper limit temperature. 7. The operation control unit according to claim 2 , wherein the operation control unit is configured to stop the heater heat recovery type high-temperature heating treatment when the rate of increase in the temperature of hot water in the hot water storage tank becomes equal to or less than a set rate. Combined heat and power system.

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