JP7244950B2 - Hot water supply system, method, program and cogeneration system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat utilization technology that utilizes thermal energy generated in a gas engine or a fuel cell to heat hot water.

2. Description of the Related Art There is known a hot water supply system that uses thermal energy, such as thermal energy generated by an engine generator using gas or the like as a fuel or a fuel cell, or solar heat, to heat hot water.
In such a hot water supply system, auxiliary heating is performed when the amount of heat stored is insufficient for the amount of heat required for hot water supply. The auxiliary heat source uses, for example, gas combustion heat from a burner to supply hot water at the required temperature.
Regarding such a hot water supply system, a system in which an auxiliary heat source is arranged downstream of a solar water heater is known (Patent Document 1). As for the efficient use of the auxiliary heat source, it is known that the auxiliary heat source is activated when hot water is supplied, and heat radiation to the atmosphere and fuel consumption are reduced compared to keeping warm water in the hot water storage tank. (For example, Patent Document 2).

JP 2003-148804 A JP 2007-311036 A

By the way, in a hot water supply system, a heat storage water heater that collects and stores heat from a heat source such as an engine generator, fuel cell, or solar heat, and an auxiliary heat source that heats the hot water supplied from this heat storage water heater are independent devices. may be configured. The heat storage hot water supply device and the auxiliary heat source are connected by piping, and the auxiliary heat source heats hot water according to the state of the stored thermal energy, and can supply hot water to the hot water supply load side at a temperature that matches the hot water supply request.
However, in such a hot water supply system, the heat storage hot water supply device and the auxiliary heat source are sometimes arranged apart in order to secure an installation space, for example. In this case, the auxiliary heat source may be supplied with hot water whose temperature has changed from when the hot water was discharged from the heat storage hot water supply device due to the arrangement environment, climate, and the like. In a hot water supply system, for example, if the heat storage water heater and the auxiliary heat source are controlled at the same target temperature, even if the heat storage in the heat storage water heater is sufficient, the auxiliary heat source will perform heat treatment each time hot water is supplied. There is a problem that the heat energy of the exhaust heat source cannot be effectively used due to the increased consumption. In addition, in a hot water supply system, for example, monitoring the outside air temperature and the temperature of the piping between the heat storage hot water supply device and the auxiliary heat source, and controlling the combustion amount of the auxiliary heat source according to the temperature state will make the process complicated. I have a problem.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to effectively utilize stored thermal energy in a hot water supply system in which an auxiliary heat source is installed away from a hot water supply apparatus in order to solve such problems.

In order to achieve the above object, according to one aspect of the hot water supply system of the present invention, a heat medium that recovers heat from a heat source is stored in a heat storage tank, and heat is exchanged between the heat medium and feed water to generate hot water. a hot water supply unit, a backup heat source device that receives the hot water from the first hot water supply unit and heats the hot water as needed, and temperature detection means that detects the temperature of the hot water discharged by the first hot water supply unit. a second hot water supply unit for discharging the hot water or hot water heated by the backup heat source device; and detection temperature information of the hot water discharged by the first hot water supply unit and flowing into the second hot water supply unit. a control unit for receiving and controlling the backup heat source device, wherein when the first hot water supply unit supplies hot water to the second hot water supply unit at a set temperature, the hot water flowing into the second hot water supply unit If the temperature change from the set temperature is within the threshold, the hot water is discharged from the second hot water supply unit without operating the backup heat source equipment , and the temperature change of the hot water from the set temperature is within the threshold. If it is larger than the value, the hot water is heated to the set temperature by the backup heat source device and discharged from the second hot water supply unit, and the difference information between the hot water flowing into the second hot water supply unit and the set temperature. The temperature of hot water discharged from the first hot water supply unit is corrected based on .

In order to achieve the above object, according to one aspect of the hot water supply method of the present invention, a first hot water supply unit stores a heat medium recovered from heat from a heat source in a heat storage tank, and heat-exchanges the heat medium with feed water. a second hot water supply unit receiving the hot water from the first hot water supply unit and, if necessary, operating a backup heat source machine to supply the hot water; a step of detecting the temperature of the hot water discharged by the first hot water supply unit and flowing into the second hot water supply unit; In this case, if the temperature change from the set temperature of the hot water flowing into the second hot water supply unit is within a threshold value, the hot water supplied from the first hot water supply unit without operating the backup heat source machine. is supplied from the second hot water supply unit, and if the change in temperature of the hot water from the set temperature is greater than the threshold value, the backup heat source equipment heats the hot water to the set temperature, and the second hot water supply is performed. discharging hot water from the unit, and correcting the temperature of discharged hot water from the first hot water supply unit based on difference information between the hot water flowing into the second hot water supply unit and the set temperature.

In order to achieve the above object, according to one aspect of the program of the present invention, there is provided a hot water supply program to be executed by a computer, comprising: a function of exchanging heat between a heat medium and water supply to generate hot water; a second hot water supply unit receives the hot water from the first hot water supply unit; a function of supplying hot water, a function of acquiring detected temperature information from temperature detection means for detecting the temperature of the hot water discharged by the first hot water supply unit and flowing into the second hot water supply unit , and the first hot water supply. When the unit supplies hot water to the second hot water supply unit at a set temperature, if the change in temperature of the hot water flowing into the second hot water supply unit from the set temperature is within a threshold value, the backup heat source machine is operated. The hot water supplied from the first hot water supply unit is discharged from the second hot water supply unit , and if the temperature change of the hot water from the set temperature is greater than the threshold value, the backup heat source machine Hot water is heated to the set temperature and discharged from the second hot water supply unit, and hot water is supplied from the first hot water supply unit based on difference information between the hot water flowing into the second hot water supply unit and the set temperature. and a function of correcting the outlet heated water temperature .

In order to achieve the above object, according to one aspect of the cogeneration system of the present invention, there is provided a cogeneration system comprising at least one of an engine, a fuel cell, and a solar heat exchanger as a heat source, and recovering heat from the heat source. a first hot water supply unit that stores a heat medium in a heat storage tank and heat-exchanges the heat medium with feed water to generate hot water; receives the hot water from the first hot water supply unit and heats the hot water as necessary a second hot water supply unit comprising a backup heat source machine and temperature detection means for detecting a hot water discharge temperature of the hot water discharged by the first hot water supply unit, and discharging the hot water or hot water heated by the backup heat source machine; a controller for receiving detected temperature information of the hot water flowing from the first hot water supply unit into the second hot water supply unit by the temperature detection means and controlling the backup heat source machine, wherein the first hot water supply unit When hot water is supplied to the second hot water supply unit at a set temperature, if the change in temperature of the hot water flowing into the second hot water supply unit from the set temperature is within a threshold value, the backup heat source machine is not operated. The hot water is discharged from the second hot water supply unit, and if the change in temperature of the hot water from the set temperature is greater than the threshold value, the backup heat source equipment heats the hot water to the set temperature, and the second hot water supply unit heats the hot water to the set temperature. and corrects the temperature of hot water discharged from the first hot water supply unit based on the difference information between the hot water flowing into the second hot water supply unit and the set temperature.

According to the present invention, one of the following effects can be obtained.

(1) Exhaust heat from an exhaust heat source such as an engine, a fuel cell, or a solar heat exchanger can be stored, and this heat can be effectively used for hot water heating, so that exhaust heat can be used efficiently.

(2) By limiting the operation of the auxiliary heat source according to the heat storage state, it is possible to prevent wasteful combustion of fuel gas and save energy.

(3) It is possible to realize hot water supply processing according to the set temperature regardless of the heat storage state.

(4) The auxiliary heat source performs heating control based on the information when the heat storage is sufficient, so that the hot water supply at the same temperature can be continued regardless of the change in the heat storage state.

(5) By notifying the heat storage hot water supply device of the temperature flowing into the auxiliary heat source and adjusting the hot water supply temperature, it is possible to supply hot water at the set temperature according to the installation environment of the hot water supply system, and the auxiliary heat source. can reduce the amount of combustion.

Other objects, features and advantages of the present invention will become clearer with reference to the accompanying drawings and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structural example of the hot water supply system which concerns on 1st Embodiment. 6 is a flowchart showing an example of hot water supply control processing; FIG. 2 is a diagram showing a configuration example of a hot water supply system according to a second embodiment; FIG. 6 is a flowchart showing an example of hot water supply control processing; It is a figure which shows the structural example of the cogeneration system which concerns on 3rd Embodiment. It is a figure which shows the example of a state in a thermal storage tank. It is a figure which shows an example of the control part of a cogeneration system. 4 is a flow chart showing an outline of linked control of each device that constitutes the cogeneration system. 4 is a flowchart showing an example of heat recovery processing for a fuel cell unit; 5 is a flow chart showing an example of heat storage hot water supply processing of the heat storage hot water supply device. 4 is a flowchart showing an example of backup hot water supply processing in the auxiliary heating device; FIG. 11 is a flowchart showing an example of hot water supply control processing of a cogeneration system according to a fourth embodiment; FIG. It is a flowchart which shows an example of heat storage hot water supply processing. 6 is a flowchart showing an example of backup hot water supply processing;

[First Embodiment]

FIG. 1 shows a hot water supply system according to a first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to the configuration.

The hot water supply system 2 includes a first hot water supply unit 4-1 and a second hot water supply unit 4-2. The first hot water supply unit 4-1 has a hot water supply function of, for example, accumulating heat recovered from a heat source and using the accumulated heat to heat water and supply hot water. The second hot water supply unit is an example of an auxiliary heat source that takes in the hot water discharged from the first hot water supply unit 4-1 and heats it so that it reaches the set temperature. The first hot water supply unit 4-1 and the second hot water supply unit 4-2 are connected by a connection pipeline 5. As shown in FIG. One end of the connecting pipeline 5 is connected to the hot water supply portion of the first hot water supply unit, and the other end is connected to the water supply portion of the second hot water supply unit 4-2. The connection pipeline 5 may be a straight pipe corresponding to the arrangement interval between the first hot water supply unit 4-1 and the second hot water supply unit 4-2, or may be an obstacle such as a building (not shown) at the arrangement position of the hot water supply system 2. The shape, arrangement length, etc. should be set so as to avoid the

In the hot water supply process of the hot water supply system 2, the temperature of the hot water supplied from the first hot water supply unit 4-1 is used as a criterion for controlling whether or not auxiliary heating is to be performed in the second hot water supply unit 4-2.

<First hot water supply unit 4-1>
The first hot water supply unit 4-1 includes a heat storage tank 6 that collects and stores heat from an external heat source 8, for example. It also has a heat exchange unit 10-1 that boils hot water using the heat stored in the heat storage tank 6, and a temperature detection unit 12-1 that monitors the water supply temperature and the heat storage state in the heat storage tank 6.
The heat storage tank 6 has, for example, a circulation pipeline formed between it and the heat source 8 , and stores therein a heat medium for recovering the heat generated from the heat source 8 . The heat source 8 is, for example, a heat generating device such as an engine generator, a fuel cell, or a solar system that recovers solar heat. The heat medium is, for example, water, antifreeze liquid, or other medium in a liquid state or a state close thereto. In the heat storage process, for example, when a heat medium having a lower temperature than the exhaust heat of the heat source 8 is supplied from the heat storage tank 6 into the pipeline, the heat medium exchanges heat with the heat generating portion and is heated. The heat source 8 absorbs heat through heat exchange with a heat medium and is cooled. The heat medium that has undergone heat exchange is stored in the heat storage tank 6 from the upper side thereof.
Furthermore, as will be described later, for example, the heat storage tank 6 is formed with a circulation pipeline between it and the heat exchange section 10-1, allowing the high-temperature heat medium in the heat storage tank 6 to pass through the heat exchange section 10-1. At this time, the heat exchange unit 10-1 takes in, for example, the low-temperature water supply W according to the hot water supply request, and heats the water supply W by heat-exchanging the water supply W with the high-temperature heat medium to generate the hot water HW. The heat medium cooled by heat exchange with the feed water W is sent to the heat source 8 side again to store heat.
The first hot water supply unit 4-1 includes heat recovery processing for the heat source 8, heat storage state monitoring processing in the heat storage tank 6, processing for generating heat storage state information from the monitoring results, and hot water supply at a predetermined temperature using the heat storage. A control unit 14-1 for controlling hot water supply processing and the like is provided. The control unit 14-1 includes, for example, a storage unit 16-1, which is an example of means for storing setting temperature information set by hot water supply request, heat storage state information in the heat storage tank 6, and the like. In addition, control unit 14-1 notifies the generated heat storage state information to second hot water supply unit 4-2.

<Second hot water supply unit 4-2>
The second hot water supply unit 4-2 includes, for example, a backup heat source device 18 that heats the hot water supplied through the connection pipe 5, a control unit 14-2 that controls the second hot water supply unit 4-2, the supplied hot water and A temperature detection section 12-2 is provided for detecting the temperature of hot water discharged from the second hot water supply unit 4-2. That is, the second hot water supply unit 4-2 may use a water heater that heats the supplied water.
The backup heat source device 18 includes, for example, a combustion section 20 and a heat exchange section 10-2.
Combustion unit 20 is an example of an auxiliary heat source such as a burner that burns fuel gas to generate combustion exhaust gas. The heat exchange section 10-2 is an example of a functional section that performs heat exchange between liquids or heat exchange between liquids and gases, and may heat-exchange the supplied hot water HW with combustion exhaust gas from the combustion section 20, or The hot water HW may be heated via a heat medium that has exchanged heat with combustion exhaust gas generated in the combustion unit 20 .
The control unit 14-2 includes, for example, a storage unit 16-2, and includes hot water temperature information to be discharged from the second hot water supply unit 4-2, hot water supplied from the first hot water supply unit 4-1, and hot water supply temperature information. Threshold information and the like for the requested set temperature are stored. Also, the control unit 14-2 acquires heat storage state information from the control unit 14-1.
The control unit 14-2 uses the detected temperature of the hot water detected by the temperature detection unit 12-2 and the heat storage state information of the heat storage tank 6 to control whether or not auxiliary heating by the backup heat source device 18 is performed. This control section 14-2 performs the following control.

<Control of second hot water supply unit 4-2>
(1) When the heat storage in the first hot water supply unit 4-1 is insufficient for the hot water supply request, the set temperature set at the time of the hot water supply request or the hot water supply temperature set in the control unit 14-2 is set. Then, the backup heat source device 18 is burned to supplementally heat the hot water HW from the first hot water supply unit 4-1.
(2) When the heat storage in the first hot water supply unit 4-1 is sufficient for the hot water supply request, the temperature of the hot water HW supplied to the second hot water supply unit 4-2 is detected, and the temperature of the hot water HW reaches the set temperature T. is equal to or greater than the predetermined threshold value K range (TK), auxiliary heating is not performed, and hot water is supplied at this detected temperature. That is, the backup heat source device 18 is not operated according to the instruction from the control section 14-2. Further, storage unit 16-2 stores the detected temperature of hot water HW at this time as hot water supply temperature information. The threshold value K may be set based on, for example, the pipe length and material of the connection pipe 5, the conditions of the installation environment, and the like. is an example.
(3) In addition, when the heat storage in the first hot water supply unit 4-1 is sufficient and the temperature of the hot water HW does not reach the range (TK) of the predetermined threshold value K with respect to the set temperature T. , the backup heat source device 18 is burned to perform auxiliary heating based on the set temperature T of the hot water supply request or the stored hot water supply temperature information.

<Hot water supply control of hot water supply system 2>
FIG. 2 shows an example of hot water supply control by the hot water supply system. The processing content and processing procedure shown in FIG. 2 are examples, and the present invention is not limited to such content. In FIG. 2, process L1 is the process performed by the first hot water supply unit 4-1, and process L2 is the process performed by the second hot water supply unit 4-2.
This hot water supply control is an example of the hot water supply program of the present disclosure. In response to the hot water supply request, the first hot water supply unit 4-1 utilizes the heat in the heat storage tank 6 to exchange heat with the water supply (step S1), acquires heat storage state information in the heat storage tank 6, hot water supply unit 4-2 (step S2). The heat storage state information may be acquired when, for example, hot water supply is started in response to a hot water supply request, or when the temperature state of the heat medium in the heat storage tank 6 changes.

Next, the second hot water supply unit 4-2 receives the heat storage state information from the first hot water supply unit 4-1 and stores it in the storage unit 16-2 (step S3). is taken in (step S4). The control unit 14-2 judges whether the heat storage state information and the detected temperature are above the threshold range with respect to the set temperature (step S5), and performs auxiliary heating processing at the hot water supply temperature or stop control of the backup heat source device 18. Output (step S6). Further, the control unit 14-2 stores the detected temperature of the hot water HW as the hot water supply temperature (step S7).

<Effects of the first embodiment>

According to such a configuration, the following effects are obtained.

(1) When the first hot water supply unit 4-1 supplies hot water at the set temperature, if the temperature change is within the threshold assumed in advance due to the arrangement environment of the connection pipe 5, etc., the second hot water supply unit 4-2 Since the backup heat source device 18 is not operated, it is possible to prevent supplementary heating each time hot water is supplied, thereby suppressing fuel gas consumption.

(2) By judging whether or not to perform auxiliary heating according to the state of heat storage in the heat storage tank 6, the stored heat energy can be effectively used.

(3) The second hot water supply unit 4-2 stores the detected hot water temperature taken in from the first hot water supply unit 4-1 as the hot water supply temperature, and performs combustion control of the backup heat source device 18 based on this hot water supply temperature. Thus, stable hot water supply processing can be executed without changing the temperature of the hot water discharged from the load depending on the presence or absence of auxiliary heating.

(4) By setting the detected temperature of the hot water taken in from the first hot water supply unit 4-1 as the hot water supply temperature, the hot water is supplied at the same temperature as when using the stored heat energy, and excessive auxiliary heating is not performed. Therefore, waste of fuel gas can be prevented.

[Second embodiment]

FIG. 3 shows a configuration example of a hot water supply system according to the second embodiment. In FIG. 3, the same reference numerals are given to the same parts as in FIG.
The hot water supply system 2 is an example of the hot water supply system, the hot water supply program, and the cogeneration system of the present disclosure, and uses the temperature of the water entering the hot water supply unit 4-2 as the reference temperature for hot water supply control of the hot water supply system 2. FIG.
The hot water supply system 2 may have the same configuration as that shown in the first embodiment, and detailed description thereof will be omitted.
In the first hot water supply unit 4-1, for example, in the storage section 16-1, heat storage state information indicating the state of the heat storage tank 6 is stored, and set temperature information based on the hot water supply request is stored.
In the second hot water supply unit 4-2, for example, the storage unit 16-2 stores set temperature information acquired when hot water supply is requested, hot water supply temperature information used for operation processing of the second hot water supply unit 4-2, and threshold information. etc. are stored.
Further, the second hot water supply unit 4-2 transmits the detected detected temperature information, which is the state information of the supplied hot water HW, or the difference temperature information with respect to the set temperature, to the controller 14- of the first hot water supply unit 4-1. 1.

In such a configuration, the control unit 14-2 uses the detected temperature of the hot water HW detected by the temperature detection unit 12-2 and the heat storage state information of the heat storage tank 6 to perform auxiliary heating processing by the backup heat source device 18. At the same time, so-called feedback (FB) processing is performed to notify the first hot water supply unit 4-1 that the hot water being supplied does not match the set temperature of the hot water supply request and to prompt adjustment of the hot water supply control.
In the hot water supply system 2, for example, the following processing is performed as hot water supply control.

<Control of second hot water supply unit 4-2>
(1) In response to the hot water supply request, the control unit 14-2 adjusts the set temperature set at the time of the hot water supply request based on the detected temperature information of the hot water HW, regardless of the heat storage state of the first hot water supply unit 4-1. Auxiliary heating is performed by burning the backup heat source equipment 18 so that
(2) When the heat storage in the first hot water supply unit 4-1 is sufficient for the hot water supply request, the control unit 14-2 uses the stored detected temperature information or difference temperature information between the detected temperature information and the set temperature information. is notified to the first hot water supply unit 4-1.

<Control of first hot water supply unit 4-1>
(1) The first hot water supply unit 4-1 generates heat storage state information in the heat storage tank 6 and notifies the second hot water supply unit 4-2.
(2) Then, when the heat storage is sufficient, the control unit 14-1 adjusts the opening of a pump and an on-off valve (not shown) so that the set temperature is reached, and the high-temperature heat medium in the heat storage tank 6 and the water supply W are Hot water HW is generated by heat exchange. If the heat storage is insufficient, the control unit 14-1 heats the water supply W to a temperature as close as possible to the set temperature, and sends the water supply W to the second hot water supply unit 4-2 side.
(3) When control unit 14-1 acquires the detected temperature information or differential temperature information from second hot water supply unit 4-2, it corrects the hot water supply temperature based on the detected temperature information or differential temperature information. That is, the hot water supply temperature is set to the set temperature on the second hot water supply unit 4-2 side. Basically, hot water supply temperature≧set temperature.

<Hot water supply control of hot water supply system 2>
FIG. 4 shows an example of hot water supply control by the hot water supply system. The processing content and processing procedure shown in FIG. 4 are examples, and the present invention is not limited to such content. In FIG. 4, process L1 is the process performed by the first hot water supply unit 4-1, and process L2 is the process performed by the second hot water supply unit 4-2. This hot water supply control is an example of the hot water supply control program of the present disclosure.

In this hot water supply control, steps S11 to S14 are the same processes as steps S1 to S4 in FIG. 2, and the description thereof will be omitted.
The second hot water supply unit 4-2 refers to the acquired heat storage state information and stores the detected temperature information or differential temperature information (step S15).
Further, control unit 14-2 notifies detected temperature information or differential temperature information to first hot water supply unit 4-1 (step S16).
When the temperature of the entering hot water HW is lower than the set temperature, the control unit 14-2 operates the backup heat source device 18 to heat the hot water, and then discharges hot water to the load (step S17).

The first hot water supply unit 4-1 adjusts the hot water supply temperature based on the received detected temperature information or differential temperature information (step S18).

In this embodiment, second hot water supply unit 4-2 performs auxiliary heating when there is a difference between the detected temperature of hot water HW and the required hot water supply temperature. Not exclusively. For example, when the differential temperature value is small, the second hot water supply unit 4-2 may perform processing such as not performing auxiliary heating, or performing auxiliary heating after waiting for a predetermined period of time. In the auxiliary heating process, the amount of hot water to be supplied may be determined not only based on the detected temperature information but also by using a flow rate sensor. That is, when the amount of hot water supply is small and the differential temperature is small, auxiliary heating may not be performed based on the minimum combustion capacity of the backup heat source device 18 or the like.

<Effects of Second Embodiment>
According to such a configuration, the following effects are obtained.

(1) By correcting the hot water supply temperature in the first hot water supply unit 4-1 based on the detected temperature information on the second hot water supply unit 4-2 side, the hot water supply process can be performed in consideration of the temperature drop between the hot water supply units. It is possible to reduce the number of times the auxiliary heat treatment is performed.

(2) Fuel gas consumption can be reduced by reducing the number of times auxiliary heating is performed and preferentially using the stored thermal energy.

(3) Since the temperature of the hot water HW is adjusted according to the temperature drop of the hot water HW between the hot water supply units, the hot water supply process can be performed at the requested temperature in response to the installation environment of the hot water supply system 2 and seasonal temperature changes. It can be carried out.

[Third Embodiment]

FIG. 5 shows a configuration example of a cogeneration system according to the third embodiment. 5, the same parts as in FIG. 1 are given the same reference numerals.
This cogeneration system 30 is an example of a hot water supply system and a cogeneration system of the present disclosure. For example, as shown in FIG. An auxiliary heating device 34-2, which is an example of a hot water supply unit, is provided. The cogeneration system 30 also includes a fuel cell unit 36 as a heat source, for example.

The heat storage hot water supply device 34-1 has a heat storage function and a hot water supply function. The heat storage hot water supply device 34-1 is provided with a heat storage tank 6 in which the first heat medium HM1 is stored. The high-temperature heat medium HM<b>1 heated by cooling is returned to the upper layer of the heat storage tank 6 . As a result, heat storage is performed in a hierarchical state. For example, an open heat storage tank is used as the heat storage tank 6 . The heat medium HM<b>1 is a heat medium for cooling on the exhaust heat source side, recovers heat from the exhaust heat source, and stores the heat in the heat storage tank 6 . The heat storage tank 6 is provided with a plurality of temperature sensors for detecting the temperatures of the upper, middle and lower layers of the heat medium in the tank, and the detected temperature T1 of the temperature sensor 40-1 represents the temperature of the upper layer of the heat medium. Due to this heat storage function, in the hot water supply function, the heat of the heat medium HM1 is heat-exchanged with the water supply W, and the hot water HW is supplied.

During hot water supply, the water supply W supplied to the water supply path 38-2 flows into the heat exchanger 42-1. At this time, by driving the circulation pump 44-1, the heat medium HM1 flows from the upper layer side of the heat storage tank 6 through the heat medium circulation path 38-3 to the heat exchanger 42-1. In the heat exchanger 42-1, the heat of the heat medium HM1 is heat-exchanged to the feed water W, and the heat of the heat medium HM1 produces hot water HW from the feed water W. This hot water HW is supplied from the hot water supply passage 38-4 of the heat storage hot water supply device 34-1.

A temperature sensor 40-2 for detecting the temperature T2 of the water supply is installed on the water supply path 38-2, for example, on the inlet side of the heat storage water heater 34-1. A mixing valve 46-1 is installed in the water supply line 38-2, and a bypass line 38-5 is provided to branch a part of the water supply W via the mixing valve 46-1 and flow it to the hot water supply line 38-4 side. is set up. As a result, the hot water HW can be mixed with the feed water W at a mixing ratio corresponding to the opening degree ratio of the mixing valve 46-1. Therefore, if the amount of heat of the heat medium HM1 in the heat storage tank 6 is equal to or greater than the amount of heat required to obtain the hot water HW of the set temperature T, the hot water HW of the set temperature T is produced by using only the hot water HW or the mixed water of the hot water HW and the feed water W. Hot water can be discharged, but if the amount of heat is insufficient, the discharged hot water temperature of the hot water HW will be lower than the set temperature T. In addition, the water supply passage 38-2 is provided with a flow rate sensor 50-1 for detecting the flow rate of the water supply W, and this detected flow rate is used for the heat exchange process between the heat medium HM1 and the water supply W. The hot water supply path 38-4 is also provided with a temperature sensor 40-3 for detecting the temperature after heat exchange and a temperature sensor 40-4 for detecting the temperature of the hot water HW when the hot water is discharged.

The hot water supply path 38-7 of the auxiliary heating device 34-2 is connected to the hot water supply path 38-4 of the heat storage hot water supply device 34-1 via a supply pipe 38-6. -7 constitutes a continuous water passage. As a result, the hot water HW discharged from the heat storage hot water supply device 34-1 is supplied to the auxiliary heating device 34-2. The hot water supply path 38-7 includes, for example, a bypass path 38- branched upstream of the heat exchanger 42-2 and connected downstream of the heat exchanger 42-2 via a mixing valve 46-3. 8 is installed. At this time, if the temperature of the hot water HW flowing through the hot water supply passage 38-7 is the set temperature T, the auxiliary heating process by the auxiliary heating device 34-2 is unnecessary, and the temperature is maintained and the hot water is discharged from the auxiliary heating device 34-2. All you have to do is In addition, the hot water supply path 38-7 is provided with a flow rate sensor 50-2 for detecting the flow rate of the hot water HW flowing into the auxiliary heating device 34-2. In the auxiliary heating process, the detected flow rate may be used for combustion control of the burner 43 and operation control of the circulation pump 44-2.

The auxiliary heating device 34-2 is provided with a burner 43 for burning fuel gas, for example, as an example of a backup heat source. The heat source used for auxiliary heating may be the heat of combustion exhaust gas from the burner 43, electric heat, or solar heat. When auxiliary heating is performed, the auxiliary heating device 34-2 operates the circulation pump 44-2 to circulate the second heat medium HM2 in the heat medium circulation path 38-9, and the combustion heat of the burner 43 is transferred to the heat exchanger. At 42-3, heat is exchanged with the heat medium HM2. The combustion heat amount of the burner 43 is adjusted so that the heat transfer medium HM2 after heat exchange reaches a predetermined temperature T9, for example, 80[° C.]. The temperature of the heat medium HM2 is detected, for example, by a temperature sensor 40-9 that detects the temperature of the heat medium HM2 after heat exchange. As a result, the heat medium HM2 is heated by the burner 43 to compensate for the shortage of the heat amount of the heat medium HM1. In addition, the heat medium circuit 38-9 may be provided with an accumulator 52 for controlling the pressure of the heat medium HM2.

In the auxiliary heating process, when the detected temperature T6 of the temperature sensor 40-6 installed on the inlet side of the hot water supply passage 38-7 is lower than the set temperature T, the hot water HW is caused to flow into the heat exchanger 42-2, and heat is generated. The medium HM2 and the hot water HW are heat-exchanged to heat the hot water HW. A temperature sensor 40-7 detects the temperature T7 of the hot water HW on the outlet side of the heat exchanger 42-2. The hot water HW after heat exchange can be mixed with the hot water HW before heat exchange by the mixing valve 46-4 at a mixture ratio according to the opening degree ratio between the hot water supply passage 38-7 side and the bypass passage 38-8 side. be. That is, if the detected temperature T7 of the hot water HW after heat exchange is higher than the set temperature T, the mixed water HW at the set temperature T is mixed with the hot water HW before heat exchange from the bypass passage 38-8 at a predetermined mixing ratio. Let the water out. The temperature of the mixed water HW is detected by the temperature sensor 40-8 in the hot water supply passage 38-7, and the detected temperature T8 is used to adjust the opening of the mixing valve 46-4 that adjusts the mixed water HW to the set temperature T. Used.

<Configuration of fuel cell unit 36>
The fuel cell unit 36 is an example of an exhaust heat source of the heat storage water heater 34-1, and has a fuel cell 48 as this heat source. A heat exchanger 42-4 is installed in the fuel cell unit 36, and exhaust HM3 of the fuel cell 48 flows through an exhaust path 38-10. A heat medium circuit 38-1 is installed in the heat exchanger 42-4. By operating the circulation pump 44-3, the heat medium HM1 circulates in the heat exchanger 42-4 and is heated by exhaust heat of the high-temperature exhaust HM3 flowing through the exhaust path 38-10. In the heat medium circulation path 38-1, the temperature sensor 40-10 detects the inlet temperature T10 of the heat exchanger 42-4, and the temperature sensor 40-11 detects the outlet temperature T11.

The heat medium HM1 flows from the lower layer side of the heat storage tank 6 to the heat medium circulation path 38-1 and is returned to the upper layer side of the heat storage tank 6 after heat exchange with exhaust heat in the heat exchanger 42-4. Thereby, hierarchical heat storage of the heat medium HM1 is performed. The heat storage tank 6 is provided with a plurality of temperature sensors at different height positions from the upper layer side to the lower layer side. The temperature sensor 40 - 1 detects the temperature of the heat medium on the uppermost layer side of the heat storage tank 6 . The temperature sensor 40-5 detects the temperature of the heat medium at a position lower than the temperature sensor 40-1.

In addition, the cogeneration system 30 includes, for example, a heat storage water heater control unit 60-1 that controls the heat storage water heater 34-1, an auxiliary heating device control unit 60-2 that controls the auxiliary heating device 34-2, a fuel cell unit, 36 is provided with a fuel cell unit control section 60-3. Further, a remote control device 64 (FIG. 7) that communicates with each control unit to exchange instruction information may be provided.

<Heat storage state in heat storage tank 6>
FIG. 6 shows an example of the state inside the heat storage tank. The installation position of the temperature sensor 40-1 in the upper layer of the heat storage tank 6 may be set according to, for example, the heating capacity and heating rate of the heat medium HM2 for auxiliary heating. The position of the temperature sensor 40-1 is at least a position that detects the temperature of the heat medium HM1 at a volume level capable of ensuring time to complete the start-up of the burner 43 before the heat amount of the heat medium HM1 is used for hot water supply. If it is For example, if the regulated flow rate of 24 [liters/min] can be heated in 10 [seconds], set the volume level position corresponding to 4 [liters] or more of the heat medium amount, and set the heat medium temperature at that position. To detect. In the figure, the dashed line X indicates a watershed line between the heat medium HM1 on the upper layer side and the low-temperature heat medium LHM1 on the lower layer side.

The heat storage state of the heat storage tank 6 is determined, for example, by whether or not the temperature T1 detected by the temperature sensor 40-1 is higher than the set temperature T of the hot water supply request by a predetermined temperature β. That is, the heat storage state is determined by whether or not the heat medium HM1 stored in the heat storage tank 6 can supply hot water at the set temperature T. Accordingly, if the detected temperature T1 is T1<(T+β), it is determined that there is no heat storage, and if T1≧(T+β), it is determined that there is heat storage.

<About the control unit>
FIG. 7 shows an example of the control section of the cogeneration system 30. As shown in FIG. The control unit 62 includes a heat storage water heater control unit 60-1, an auxiliary heating device control unit 60-2, a fuel cell unit control unit 60-3, and a remote control unit 60-4, which are configured by a computer having a communication function. be
The heat storage water heater control unit 60-1 is control means for the heat storage water heater 34-1, and includes a processor 66-1, a memory unit 68-1, a system communication unit 70-1, an input/output unit (I/O) 72-. 1, and performs hot water supply control of the heat storage hot water supply device 34-1. A processor 66-1 executes an OS (Operating System) and a hot water supply program stored in a memory unit 68-1, and controls an auxiliary heating device control unit 60-2 and a fuel cell unit control unit 60-2 through a system communication unit 70-1. 3 and remote controller 60-4 to execute information processing necessary for hot water supply control. The memory unit 68-1 includes ROM (Read-Only Memory) and RAM (Random-Access Memory). A storage element such as a hard disk device or a non-volatile memory for storing data is used for this memory unit 68-1. The RAM constitutes a work area for information processing. The system communication unit 70-1 communicates with the system communication units of the auxiliary heating device control unit 60-2, the fuel cell unit control unit 60-3, and the remote control control unit 60-4 by wire or wirelessly. Send and receive information. The I/O 72-1 receives detection signals from various temperature sensors such as the temperature sensor 40-1 in the heat storage water heater 34-1 and the flow rate sensor 50-1, and controls the mixing valve 46-1 and circulation pump 44-1. Output a signal.

The auxiliary heating device control unit 60-2 is control means for the auxiliary heating device 34-2, and includes a processor 66-2, a memory unit 68-2, a system communication unit 70-2, and an I/O unit 72-2. Hot water supply control of the device 34-2 is performed. The processor 66-2 executes the OS and the hot water supply program in the memory unit 68-2, and controls the heat storage water heater control unit 60-1, the fuel cell unit control unit 60-3, and the remote controller through the system communication unit 70-2. In cooperation with the unit 60-4, information processing necessary for hot water supply control is executed. The memory unit 68-2 includes ROM and RAM. A storage element such as a hard disk device or a non-volatile memory for storing data is used for this memory unit 68-2. The RAM constitutes a work area for information processing. The system communication unit 70-2 communicates with the system communication units on the side of the heat storage water heater control unit 60-1, the fuel cell unit control unit 60-3, and the remote control unit 60-4 by wire or wirelessly, Send and receive information. The I/O 72-2 receives detection signals from various temperature sensors such as the temperature sensor 40-6 in the auxiliary heating device 34-2, and the flow rate sensor 50-2. A control signal for the combustion control unit 74 of 43 is output.

The fuel cell unit control section 60-3 is control means for the fuel cell unit 36, and includes a processor 66-3, a memory section 68-3, a system communication section 70-3, and an I/O section 72-3. drive control. The processor 66-3 executes the OS and the hot water supply program stored in the memory unit 68-3, and controls the heat storage hot water supply device control unit 60-1, the auxiliary heating device control unit 60-2, and the remote controller through the system communication unit 70-3. In cooperation with the unit 60-4, information processing necessary for hot water supply control is executed. The memory unit 68-3 includes ROM and RAM. A storage element such as a hard disk device or a non-volatile memory for storing data is used for this memory unit 68-3. The RAM constitutes a work area for information processing. The system communication unit 70-3 communicates with the system communication unit on the side of the heat storage hot water supply device control unit 60-1, the auxiliary heating device control unit 60-2, and the remote control unit 60-4 by wire or wirelessly. Send and receive information. The I/O 72-3 receives detection signals from the temperature sensors 40-10 and 40-11 in the fuel cell unit 36, and outputs control signals for the circulation pump 44-3 and others 76 related to fuel cell control.

A remote control unit 60-4 is provided in a remote control device 64, and cooperates with independent heat storage water heater control unit 60-1, auxiliary heating device control unit 60-2, and fuel cell unit control unit 60-3 by computer communication.

<Procedure for cooperative control>
FIG. 8 shows an outline of linked control of each device that constitutes the cogeneration system 30 . The processing content shown in FIG. 8 is an example of the hot water supply program of the hot water supply system of the present disclosure and the control method of the cogeneration system.
Regarding this processing procedure, the remote control device 64 performs initialization (S21), input reception processing (S22), and display output processing (S23) at startup. Initial settings are performed by the user in the input acceptance process. This initial setting includes, for example, inputting the set temperature T of the hot water supply to the heat storage hot water supply device 34-1 and the auxiliary heating device 34-2, and switching ON/OFF of the operation of the fuel cell unit 36. FIG. In the display output process, input information and output information are presented on the display section of the remote control device 64 .

In the fuel cell unit 36, initialization is performed (S31), and heat recovery processing (S32) is performed. The heat recovery process is instructed to start or end by switching operation ON/OFF from the remote control device 64 .

In the heat storage water heater 34-1, initialization is executed (S41), and heat storage hot water supply process I (S42) is executed. This heat storage hot water supply process is an example of the hot water supply process of the present disclosure, receives a set temperature T as setting information from the remote control device 64, and controls the outlet temperature of the hot water HW to the set temperature T. FIG. In this heat storage hot water supply process, the auxiliary heating device 34-2 is notified of "with heat storage" or "without heat storage" as the heat storage state information of the heat storage tank 6. FIG. In addition, the heat storage water heater 34-1 may perform maintenance or the like as management processing.

The auxiliary heating device 34-2 executes initialization (S51) and executes auxiliary heating process I (S52). In this auxiliary heating process, the set temperature T as setting information from the remote control device 64 and the heat storage state information "with heat storage" or "without heat storage" from the heat storage water heater 34-1 are received. Then, in the auxiliary heating device 34-2, whether or not there is heat storage in the heat storage tank 6 is determined based on the temperature of hot water discharged from the heat storage hot water supply device 34-1, and the temperature of the incoming hot water is a predetermined temperature difference from the set temperature T. The execution and stop of the auxiliary heat treatment are controlled depending on whether or not the In addition, the auxiliary heating device 34-2 may perform maintenance or the like as management processing.

<Heat recovery treatment>
FIG. 9 shows the procedure of the heat recovery process of the fuel cell unit 36. As shown in FIG.
The fuel cell unit 36 determines whether the operation is ON (S321), and if the operation is ON (YES in S321), drives the fuel cell 48 (S322). In driving the fuel cell 48, the rotation of the circulation pump 44-3 is controlled so that the temperature T11 detected by the temperature sensor 40-11, which detects the OUT temperature after heat recovery, becomes a constant temperature, for example, 75[°C]. S323).
If the operation is not ON (NO in S321), the driving of the fuel cell 48 is stopped or the stopped state is maintained (S324). When the driving of the fuel cell 48 is stopped, the rotation of the circulation pump 44-3 is stopped (S325).

<Heat storage hot water supply process I>
FIG. 10 shows an example of the heat storage hot water supply process (S42) of the heat storage hot water supply device 34-1.
The heat storage water heater control unit 60-1 determines whether or not heat is stored in the heat storage tank 6 based on the detected temperature state in the heat storage tank 6 (step S421). The heat storage state information indicating "with heat storage" is transmitted to the device 34-2 (step S422). If there is no heat storage (NO in step S421), the heat storage state information of "no heat storage" is transmitted to at least the auxiliary heating device 34-2 (step S423). As described above, the heat storage state may be determined using the input set temperature T and the temperatures detected by the temperature sensors 40-1 and 40-5 in the heat storage tank 6, and the like.

Heat storage hot water supply device control unit 60-1 determines whether or not hot water supply is used from the detection result of flow rate sensor 50-1 (step S424). It is exchanged (step S425). Then, heat storage hot water supply device control unit 60-1 determines whether hot water supply at set temperature T is possible by determining whether temperature T3 detected by temperature sensor 40-3 is higher than set temperature T (step S426). ). That is, this determination is a determination as to whether or not heat is stored in the heat storage tank. If hot water can be supplied at the set temperature T (YES in step S426), the opening of the mixing valve 46-1 is controlled so that the temperature detected by the temperature sensor 40-4 becomes the set temperature T (step S427).

If hot water cannot be supplied at the set temperature T (NO in step S426), the heat storage hot water supply device 34-1 can supply hot water to the auxiliary heating device 34-2 at a temperature as close to the set temperature T as possible.
If hot water supply is not used (NO in step S424), heat storage hot water supply device control unit 60-1 stops hot water supply (step S429).

The transmission of the heat storage state information of the heat storage tank 6 is triggered by a state change, such as when a hot water supply request occurs, when the state inside the heat storage tank 6 changes, or when the set temperature T for the hot water supply request changes. You can go to

Alternatively, the heat storage water heater 34-1 may transmit only temperature information detected by the temperature sensors 40-1, 40-5, etc., to the auxiliary heating device 34-2 or the remote control device 64 as heat storage state information. , the determination of whether or not heat is accumulated may be made by the auxiliary heating device 34-2 or the remote control device 64. FIG.

<Auxiliary heat treatment I>
FIG. 11 shows an example of the auxiliary heating process I of the auxiliary heating device 34-2.
In auxiliary heating device control unit 60-2, for example, set temperature T notified from remote control device 64 is set in memory unit 68-2 as the water heater set temperature (step S521). This hot water supply set temperature is an example of the hot water supply temperature of the auxiliary heating device 34-2, and is a target temperature for supplying hot water. A set temperature T is set as an initial value for the hot water supply set temperature. It is determined whether hot water supply is used (step S522), and if hot water supply is used (YES in step S522), it is determined whether or not the heat storage tank 6 is "stored heat" (step S523). The decision to use the hot water supply may be made by referring to the detection result of the flow rate sensor 50-2, for example. If there is heat storage (YES in step S523), the temperature sensor 40-6 is referred to, and the detection temperature T6, which is the incoming water temperature, is set to a predetermined threshold value K with respect to the set temperature T, for example, within a range of 2 [°C] ( TK) or not (step S524). If the incoming water temperature is equal to or higher than the range of the threshold value K (YES in step S524), the incoming water temperature (T-α), which is the detected temperature T6 at this time, is stored as the water heater set temperature in the memory unit 68-2. (Step S525). The stored "α" is the temperature difference between the set temperature T and the detected incoming water temperature T6. If the mixing valve 46-4 is fully open to the bypass 38-8 side, the detected temperature T8 of the temperature sensor 40-8 may be stored as the set temperature of the water heater.

Then, the auxiliary heating device 34-2 stops or maintains the stopped state of the heating operation, or fully opens the mixing valve 46-4 to the side of the bypass 38-8 so that the hot water HW is supplied to the hot water supply load side in the detected temperature state. Hot water is discharged (step S526).

If the heat storage tank 6 is “no heat storage” (NO in step S523) or if the incoming water temperature is outside the range of the threshold value K (NO in step S524), the incoming water temperature is equal to or higher than the water heater set temperature. (step S527), if the temperature is equal to or higher than the set temperature of the hot water heater (YES in step S527), hot water is discharged at the same temperature (step S526), and if the temperature is low (NO in step S527), the temperature sensor The mixing valve 46-3 is controlled so that 40-8 reaches the set temperature T (step S528).
Further, if hot water supply is not used (NO in step S522), hot water supply is stopped (step S529).

If the incoming water temperature T6 to the auxiliary heating device 34-2 is less than the set temperature of the hot water heater, the heating operation is performed so as to reach the set temperature of the hot water heater. However, when the set temperature of the water heater is reached, the heating operation is not performed, and the hot water is supplied at that temperature.

<Effect of the third embodiment>
According to this embodiment, the following effects are obtained.

(1) When the heat storage hot water supply device 34-1 supplies hot water at the set temperature T, if the temperature change is within the range of the presumed threshold value K in the flow of hot water, the auxiliary heating device 34-2 assists by burner combustion. Since no heat treatment is performed, it is possible to prevent the occurrence of auxiliary heat treatment each time hot water is supplied, and it is possible to suppress fuel gas consumption.

(2) By judging whether or not to perform auxiliary heating according to the state of heat storage in the heat storage tank 6, the stored heat energy can be effectively used.

(3) The auxiliary heating device 34-2 sets the detected temperature of the hot water taken in from the heat storage hot water supply device 34-1 as the hot water supply temperature, and performs combustion control of the burner 43 based on this hot water supply temperature, thereby increasing the auxiliary heating. A stable hot water supply process can be executed without changing the hot water supply temperature to the load depending on the presence or absence.

(4) By setting the detected temperature of the hot water taken in from the auxiliary heating device 34-2 to the next hot water supply temperature, hot water is supplied at the same temperature as when using the stored heat energy, and excessive auxiliary heating is not performed. Therefore, waste of fuel gas can be prevented.

[Fourth Embodiment]

FIG. 12 shows an outline of linked control of each device that constitutes the cogeneration system 30 according to the fourth embodiment. The linked control shown in FIG. 12 is an example of the hot water supply program of the present invention, and the present invention is not limited to such processing contents and processing procedures.

In the linked control shown in FIG. 12, the control processing steps S21 to S23 of the remote control device 64 and the control processing steps S31 and S32 of the fuel cell unit are the same as those shown in FIG. 8, so description thereof will be omitted.

In the heat storage water heater 34-1, initialization is executed (S41), and heat storage hot water supply process II (S42) is executed. This heat storage hot water supply process is an example of the hot water supply process of the present disclosure, receives a set temperature T as setting information from the remote control device 64, and controls the outlet temperature of the hot water HW to the set temperature T. FIG. In this heat storage hot water supply process, the auxiliary heating device 34-2 is notified of "heat storage" or "no heat storage" as the heat storage state information of the heat storage tank 6, and the temperature sensor is sent from the auxiliary heating device 34-2. Upon receipt of the incoming water temperature information detected in 40-6, the hot water supply temperature is adjusted based on this incoming water temperature.

The auxiliary heating device 34-2 performs initialization (S51) and performs auxiliary heating II (S52). In this auxiliary heating process, the set temperature T is received from the remote control device 64 as setting information, and the outlet temperature of the hot water HW is controlled to the set temperature T. FIG. Further, heating control of the hot water HW including combustion control of the burner 43 is performed according to the heat storage state information from the heat storage hot water supply device 34-1, ie, "with heat storage" or "without heat storage". Further, the temperature of the entering hot water HW supplied from the heat storage hot water supply device 34-1 is detected, and if the detected temperature does not match the set temperature T set by the remote control device 64, heat is stored to correct the temperature of the hot water supply. The temperature information of incoming water is notified to the water heater 34-1 side.

<Heat storage hot water supply process II>
FIG. 13 shows an example of the heat storage hot water supply process (S42) of the heat storage hot water supply device 34-1.
In the heat storage hot water supply device control unit 60-1, the set temperature T set by the remote controller 64 is stored as the hot water supply temperature from the heat storage water heater 34-1 (step S61), and the heat storage state in the heat storage tank 6 is stored. judgment is made. Steps S62 to S65 for judging the heat storage state and judging whether hot water is to be supplied are the same as steps S421 to S424 in FIG. However, in this case, the set temperature T, which serves as a criterion for determining the heat storage state, is the stored supply temperature.

If hot water is to be used (YES in step S65), it is checked whether incoming water temperature information has been received from the auxiliary heating device 34-2 (step S66). It is determined whether or not the temperature is lower than the set temperature T (step S67). If the incoming water temperature is lower than the set temperature T (YES in step S67), the heat storage hot water supply device control unit 60-1 performs correction to raise the supply temperature (step S68). If the incoming water temperature is higher than the set temperature T (YES in step S69), the heat storage hot water supply device control unit 60-1 performs correction to lower the supply temperature (step S70). This supply temperature is the hot water supply temperature of the heat storage hot water supply device 34-1. That is, in this heat storage hot water supply process II, the cogeneration system 30 performs auxiliary heating processing based on the temperature of hot water discharged from the heat storage hot water supply device 34-1, and feedback control based on the water temperature information detected by the auxiliary heating device 34-2. By adjusting the outlet hot water temperature of the heat storage hot water supply device 34-1, hot water is supplied at the set temperature T.

In the heat storage hot water supply device 34-1, the stored heat is heat-exchanged with the water supply W based on the corrected hot water supply temperature (step S71). Heat storage hot water supply device control unit 60-1 determines whether hot water can be supplied at set temperature T by determining whether temperature T3 detected by temperature sensor 40-3 is higher than the supply temperature (step S72). That is, this determination is a determination as to whether or not heat is stored in the heat storage tank. If hot water can be supplied at the hot water supply temperature (YES in step S72), the mixing valve 46-1 is controlled so that the detected temperature T4 of the temperature sensor 40-4 becomes the supply temperature (step S73).

If hot water cannot be supplied at the set temperature T (NO in step S72), the heat storage hot water supply device 34-1 should supply hot water to the auxiliary heating device 34-2 so that the temperature is as close as possible to the hot water supply temperature.

If the heat storage hot water supply device 34-1 has not received the incoming water temperature information (NO in step S66), the stored heat is exchanged with the water supply W at the stored supply temperature (step S71). do.

If hot water supply is not used (NO in step S65), hot water supply is stopped (step S75).

<Auxiliary heat treatment II>
FIG. 14 shows an example of the auxiliary heating process II of the auxiliary heating device 34-2.
In the auxiliary heating device control section 60-2, for example, "0" is stored as the incoming water temperature difference record in the memory section 68-2 (step S81). This incoming water temperature difference record is an example of differential temperature information of the present disclosure, and is the temperature difference between the set temperature T and the incoming water temperature of the auxiliary heating device 34-2. This is a record regarding the temperature of hot water whether or not the heat storage hot water supply device 34-1 supplies hot water in the "with heat storage" state, and whether or not the incoming water temperature is in the range of, for example, 2[°C] or more as a threshold value K with respect to the set temperature T. .

It is determined whether hot water supply is used (step S82), and if hot water supply is used (YES in step S82), it is determined whether or not the heat storage tank 6 is "stored heat" (step S83). The decision to use the hot water supply may be made by referring to the detection result of the flow rate sensor 50-2, for example. In the case of "with heat storage" (YES in step S83), the temperature sensor 40-6 is referred to, and the detected temperature T6 is set to a predetermined threshold value K with respect to the set temperature T, for example, within a range of 2[°C] (T- K) It is determined whether or not it is equal to or greater than (step S84). If the incoming water temperature is equal to or higher than the range of the threshold value K (YES in step S84), the set temperature is subtracted from the incoming water temperature, and it is determined whether or not it matches the stored incoming water temperature difference record (step S85). If the subtraction value does not match the incoming water temperature difference record (NO in step S85), this subtraction value is newly stored as an incoming water temperature difference record in the memory unit 68-2 (step S86), and the incoming water temperature difference record and the incoming water temperature are stored. is sent to the heat storage water heater 34-1 as incoming water temperature information (step S87). In other words, the temperature difference between the set temperature and the incoming water temperature is compared with the incoming water temperature difference record. The difference and the like are transmitted to the heat storage water heater 34-1.

If the incoming water temperature is equal to or higher than the set temperature (YES in step S88), the auxiliary heating operation is stopped. At this time, the mixing valve 46-4 should be set to the bypass side. If the temperature is low (NO in step S88), the mixing valve 46-4 is controlled so that the temperature sensor 40-8 reaches the set temperature T (step S90).

If no heat is stored in the heat storage tank 6 (NO in step S83), the hot water supply process may be performed without calculating the difference of the incoming water temperature. Further, if hot water supply is not used (NO in step S82), hot water supply should be stopped (step S91).

<Effects of the fourth embodiment>
According to this embodiment, the following effects are obtained.

(1) By correcting the hot water supply temperature of the heat storage hot water supply device 34-1 based on the detected temperature information of the auxiliary heating device 34-2 side, the hot water supply process can be performed in consideration of the temperature drop between the hot water supply units, and the auxiliary heating process can be performed. can be reduced.

(2) Fuel gas consumption can be reduced by reducing the number of times auxiliary heating is performed and preferentially using the stored thermal energy.

(3) Since the hot water supply temperature of the heat storage hot water supply device 34-1 is adjusted according to the state of temperature decrease, the hot water supply process is performed at the requested temperature in response to the installation environment of the hot water supply system 32 and seasonal temperature changes. be able to.

As described above, the most preferable embodiment and the like of the present invention have been described. The invention is not limited to the above description. Various modifications and changes are possible for those skilled in the art based on the gist of the invention described in the claims or disclosed in the detailed description. It goes without saying that such modifications and changes are included in the scope of the present invention.

In the hot water supply system, hot water supply program, and cogeneration system of the present invention, the execution of the auxiliary heating process is controlled based on the temperature of the water flowing into the auxiliary heating device, and the control of the hot water device is corrected to recover It is useful because it can effectively utilize the heat energy generated and reduce the waste of fuel gas.

2 Hot water supply system 4-1 First hot water supply unit 4-2 Second hot water supply unit 5 Connection pipe line 6 Heat storage tank 8 Heat source 10-1, 10-2 Heat exchange unit 12-1, 12-2 Temperature detection unit 14- 1, 14-2 control unit 16-1, 16-2 storage unit 18 backup heat source unit 20 combustion unit 30 cogeneration system 32 hot water supply system 34-1 heat storage hot water supply device 34-2 auxiliary heating device 36 fuel cell unit 38-1, 38-3, 38-9 heat medium circulation path 38-2 water supply path 38-4, 38-7 hot water supply path 38-5, 38-8 bypass path 38-6 supply pipe 38-10 exhaust path 40-1, 40- 2, 40-3, 40-4, 40-5, 40-6, 40-7, 40-8, 40-9, 40-10, 40-11 Temperature sensor 42-1, 42-2 42-3, 42-4 heat exchanger 44-1, 44-2, 44-3 circulation pump 46-1, 46-3, 46-4 mixing valve 48 fuel cell 50-1, 50-2 flow sensor 52 accumulator 60-1 heat storage Hot water supply device control section 60-2 Auxiliary heating device control section 60-3 Fuel cell unit control section 60-4 Remote control section 62 Control section 64 Remote control device

Claims (4)

a first hot water supply unit that stores a heat medium obtained by recovering heat from a heat source in a heat storage tank, and heat-exchanges the heat medium with feed water to generate hot water;
a backup heat source device that receives the hot water from the first hot water supply unit and heats the hot water as needed; and a temperature detection means that detects the temperature of the hot water discharged from the first hot water supply unit, or a second hot water supply unit for supplying hot water heated by the backup heat source machine;
a control unit for receiving detected temperature information of the hot water discharged from the first hot water supply unit and flowing into the second hot water supply unit, and for controlling the backup heat source machine;
with
When the first hot water supply unit supplies hot water to the second hot water supply unit at a set temperature, if the temperature change from the set temperature of the hot water flowing into the second hot water supply unit is within a threshold value, the The hot water is discharged from the second hot water supply unit without operating the backup heat source machine, and if the change in temperature of the hot water from the set temperature is greater than the threshold, the backup heat source machine heats the hot water to the set temperature. and hot water is discharged from the second hot water supply unit, and the temperature of hot water discharged from the first hot water supply unit is corrected based on difference information between the hot water flowing into the second hot water supply unit and the set temperature. A hot water supply system characterized by: a step in which the first hot water supply unit stores a heat medium, which has recovered heat from a heat source, in a heat storage tank, and heat-exchanges the heat medium with feed water to generate hot water;
a step in which a second hot water supply unit receives the hot water from the first hot water supply unit and supplies the hot water by operating a backup heat source machine as necessary;
a step of detecting the temperature of the hot water discharged from the first hot water supply unit and flowed into the second hot water supply unit by a temperature detection means;
When the first hot water supply unit supplies hot water to the second hot water supply unit at a set temperature, if the temperature change from the set temperature of the hot water flowing into the second hot water supply unit is within a threshold value, the The hot water supplied from the first hot water supply unit is discharged from the second hot water supply unit without operating the backup heat source machine , and if the temperature change of the hot water from the set temperature is greater than the threshold value, the The hot water is heated to the set temperature by the backup heat source machine and discharged from the second hot water supply unit, and the first hot water supply is performed based on difference information between the hot water flowing into the second hot water supply unit and the set temperature. a step of correcting the temperature of hot water discharged from the hot water supply unit ;
hot water supply method including; A hot water supply program to be executed by a computer,
a function of accumulating in a heat storage tank a heat medium obtained by recovering heat from a heat source in the first hot water supply unit and exchanging heat between the heat medium and water supply to generate hot water;
a function of receiving the hot water from the first hot water supply unit to the second hot water supply unit and discharging the hot water by operating a backup heat source machine as necessary;
a function of acquiring detected temperature information from temperature detection means for detecting the temperature of the hot water discharged from the first hot water supply unit and flowing into the second hot water supply unit ;
When the first hot water supply unit supplies hot water to the second hot water supply unit at a set temperature, if the temperature change from the set temperature of the hot water flowing into the second hot water supply unit is within a threshold value, the The hot water supplied from the first hot water supply unit is discharged from the second hot water supply unit without operating the backup heat source machine , and if the temperature change of the hot water from the set temperature is greater than the threshold value, the The hot water is heated to the set temperature by the backup heat source machine and discharged from the second hot water supply unit, and the first hot water supply is performed based on difference information between the hot water flowing into the second hot water supply unit and the set temperature. A function to correct the hot water temperature from the hot water supply unit of
A program for causing the computer to execute. A cogeneration system comprising at least one of an engine, a fuel cell, and a solar heat exchanger as a heat source,
a first hot water supply unit that stores a heat medium obtained by recovering heat from the heat source in a heat storage tank, and heat-exchanges the heat medium with feed water to generate hot water;
a backup heat source device that receives the hot water from the first hot water supply unit and heats the hot water as necessary; a second hot water supply unit for supplying hot water or hot water heated by the backup heat source machine;
a control unit that receives detected temperature information of the hot water flowing into the second hot water supply unit from the first hot water supply unit by the temperature detection means and controls the backup heat source machine;
with
When the first hot water supply unit supplies hot water to the second hot water supply unit at a set temperature, if the temperature change from the set temperature of the hot water flowing into the second hot water supply unit is within a threshold value, the The hot water is discharged from the second hot water supply unit without operating the backup heat source machine, and if the change in temperature of the hot water from the set temperature is greater than the threshold, the backup heat source machine heats the hot water to the set temperature. and hot water is discharged from the second hot water supply unit, and the temperature of hot water discharged from the first hot water supply unit is corrected based on difference information between the hot water flowing into the second hot water supply unit and the set temperature. A cogeneration system characterized by:

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