JP2006029745A - Hot water storage type hot water supplying heat source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type hot water supplying heat source device capable of suitably executing water quality keeping operation for keeping water quality of hot water in a hot water storage tank. <P>SOLUTION: This device is provided with a heating auxiliary heating means 19w for heating a heat medium circulating in a heat medium circulating passage 21 having a heat radiating terminal 6, and a heating heat exchanger 11 for executing heat exchange between hot water supplied from a heating means H to the hot water storage tank 5 and the heat medium circulating in the heat medium circulating passage 21. A control means C executes operation for operating the heating means H as water quality keeping operation so that the state wherein a temperature of a whole of the hot water in the hot water storage tank 5 is equal to or higher than a set water quality keeping temperature is maintained for a set water quality keeping time period, and executes auxiliary temperature raising operation for operating the heating auxiliary heating means 19w in the state wherein the heat medium is circulated in the heat medium circulating passage 21 at least before the temperature of the whole of the hot water in the hot water storage tank 5 is equal to or higher than the set water quality keeping temperature during execution of water quality keeping operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention includes a hot water storage tank that is supplied with water through a water supply channel and that is supplied with hot water through the hot water supply channel.
Heating means for heating the hot water in the hot water storage tank;
Auxiliary heating means for heating hot water flowing through the hot water supply path to a target hot water temperature;
The present invention relates to a hot water storage type hot water supply heat source device provided with a control means for controlling the operation of the heating means so that hot water is stored in the hot water storage tank at a target hot water storage temperature.

Such a hot water storage type hot water supply heat source device (hereinafter sometimes simply referred to as a hot water supply heat source device) is installed mainly in each general household, such as in each detached house or in each apartment house. The operation of the heating means is controlled by the control means so that the hot water is stored in the tank at the target hot water temperature, and the hot water in the hot water storage tank is sent through the hot water supply path and supplied to hot water supply places such as kitchens and baths. When the temperature of the hot water flowing through the hot water supply path is lower than the target hot water temperature, the auxiliary heating means heats the hot water to the target hot water temperature.
In such a hot water supply heat source device, since there is a possibility that the quality of the hot water in the hot water storage tank may be deteriorated, a water quality maintenance operation for maintaining the quality of the hot water in the hot water storage tank is executed. ing.

  As a technique for preventing the deterioration of the hot water quality of the hot water storage tank in this way, conventionally, in the morning, etc., as a water quality maintenance operation, the hot water storage from the hot water storage tank to the hot water supply passage is continued. There has been a technique for performing an operation of heating the hot water of a tank to a water quality maintenance temperature (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 10-141585

  However, conventionally, as the water quality maintenance operation, the operation of heating the hot water in the hot water storage tank to the water quality maintenance temperature in a state in which hot water is continuously sent from the hot water storage tank to the hot water supply passage is executed. In other words, even during the water quality maintenance operation, if there is a demand for hot water supply, the hot water in the hot water storage tank will be sent through the hot water supply passage, and accordingly, the hot water storage tank will be supplied through the water supply passage. There has been a problem that the water quality maintenance operation cannot be performed properly, such as being unable to quickly heat the hot water in the hot water storage tank to the water quality maintenance temperature.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hot water storage type hot water supply heat source device capable of appropriately performing a water quality maintenance operation for maintaining the quality of hot water in a hot water storage tank. is there.

A hot water storage type hot water supply heat source device of the present invention includes a hot water storage tank that is supplied with water through a water supply channel and to which hot water is sent through the water supply channel,
Heating means for heating the hot water in the hot water storage tank;
Auxiliary heating means for heating hot water flowing through the hot water supply path to a target hot water temperature;
Control means for controlling the operation of the heating means so that hot water is stored in the hot water storage tank at a target hot water temperature,
The first characteristic configuration is an auxiliary heating means for heating that heats the heat medium circulating in the heat medium circuit provided with the terminal for heat dissipation,
A heating heat exchanger for exchanging heat between hot water supplied from the heating means to the hot water storage tank and a heat medium circulating in the heat medium circulation path is provided;
As the water quality maintenance operation for maintaining the quality of the hot water in the hot water storage tank, the control means controls the heating means so as to continue the state in which the hot water in the entire hot water storage tank is equal to or higher than the preset water quality maintenance temperature. While performing the operation to be operated, in a state in which the heat medium is circulated through the heat medium circulation path at least until the hot water in the entire hot water storage tank becomes equal to or higher than the set water quality maintenance temperature during the water quality maintenance operation. It is characterized by the point comprised so that the auxiliary | assistant temperature rising operation which operates the said auxiliary heating means for heating may be performed.

That is, the water quality maintenance operation is at least the entire hot water storage tank during execution of the water quality maintenance operation for operating the heating means so that the hot water in the entire hot water storage tank is at or above the set water quality maintenance temperature for a set water quality maintenance time. In the heating heat exchanger, the water supplied from the heating means to the hot water storage tank is transferred to the heating medium circulation path by performing the auxiliary heating operation until the hot water of the hot water reaches or exceeds the set water quality maintenance temperature. Then, the heating medium is further heated by the heating medium heated by the auxiliary heating means for heating.
That is, during the execution of the water quality maintenance operation, the hot water in the hot water storage tank is heated by the heating auxiliary heating means in accordance with the heating by the heating means until at least the hot water in the entire hot water storage tank reaches the set water quality maintenance temperature. Since heating is performed using a heated heating medium, it is possible to shorten the time until the hot water in the entire hot water storage tank reaches the set water quality maintenance temperature or more, and the time required for the water quality maintenance operation can be shortened. Become.

In addition to the first feature configuration described above, the second feature configuration can freely switch the heating medium circulating in the heating medium circulation path to a terminal bypassing state in which the heat dissipation terminal is bypassed through the terminal bypass. Heat medium circulation state switching means is provided,
The operation control means is configured to switch the heat medium circulation state switching means to the terminal device bypass state during execution of the water quality maintenance operation.

  That is, the operation control means is heated by the auxiliary heating means for heating in the heat medium circulation path by switching the heat medium circulation state switching means to the terminal device bypass state during execution of the auxiliary temperature raising operation. It is possible to prevent the heating medium from being supplied to the heating terminal device and unexpectedly performing heating in the heating terminal device. Further, since the heat medium circulation state switching means is switched to the terminal device detour state, the heat medium is not radiated from the heating terminal, so that the heating heat exchanger can be efficiently heated by the high-temperature heat medium. The water supplied from the means to the hot water storage tank can be heated.

In addition to the first or second characteristic configuration described above, the third characteristic configuration is more than the auxiliary heating means in the hot water supply path, with the water supplied in the water supply path bypassing the hot water storage tank through the tank bypass water supply path. A water supply state switching means is provided that can be switched to a tank bypass water supply state that supplies the upstream side and stops sending hot water from the hot water storage tank to the hot water supply path,
The control means determines whether or not it is the water quality maintenance operation timing that needs to perform the water quality maintenance operation, and when the water quality maintenance operation timing is reached, the water supply state switching means is set as the water quality maintenance operation. It is configured to switch to a tank bypass water supply state, and to perform an operation for operating the heating means so as to continue a state in which the hot water in the entire hot water storage tank is equal to or higher than a set water quality maintenance temperature for a set water quality maintenance time. It is characterized by.

  That is, the control means determines whether or not it is the water quality maintenance operation timing, and when the water quality maintenance operation timing is reached, the water supply state switching means is switched to the tank bypass water supply state, and the entire hot water storage tank A water quality maintenance operation is performed to operate the heating means so that the hot water is at or above the set water quality maintenance temperature for a set water quality maintenance time.

  That is, in the water quality maintenance operation, the water supplied in the water supply path is supplied to the upstream side of the hot water storage tank by bypassing the hot water storage tank through the tank bypass water supply path and the hot water storage tank. The heating means is operated so that the state in which the hot water in the entire hot water storage tank is equal to or higher than the set water quality maintenance temperature is continued for the set water quality maintenance time in a state where the supply of hot water to the hot water supply channel is stopped. Even when there is a demand for hot water supply during the water quality maintenance operation, water supplied from the hot water storage tank to the hot water supply path is stopped and water supplied from the hot water supply path is not supplied to the hot water storage tank. Since it is detoured and supplied to the upstream side of the auxiliary heating means in the hot water supply passage, hot water in the hot water storage tank is added by the heating means with the water supply to the hot water storage tank stopped. Therefore, the hot water in the hot water storage tank can be quickly heated to the water quality maintenance temperature, and the water of good quality supplied through the water supply channel is heated to the target hot water supply temperature by the auxiliary heating means. Can be supplied to hot water supply points.

In addition to the case where the heating means is configured with a dedicated heat source such as a burner or an electric heater, for example, a fuel cell, a rotary power generation device in which a generator is driven by an engine, etc. In some cases, the exhaust heat of the exhaust heat generation type processing device is used as a heat source so as to improve energy saving.
Such a waste heat generation type processing device is not operated independently of the hot water supply heat source device, the operation is stopped independently, the output is changed and adjusted, and the operation state is changed. Such a change in the operation state causes no exhaust heat or the amount of generated exhaust heat fluctuates. Therefore, there is a possibility that the temperature of the hot water in the hot water storage tank becomes low and the water quality may deteriorate. Although it is relatively easy to occur, when the water quality maintenance operation timing comes, such as when the temperature of the hot water in the hot water storage tank becomes low and there is a possibility that the water quality may deteriorate, by performing the water quality maintenance operation as described above, This makes it possible to maintain the water quality of the hot water storage tank.

  In short, even if there is a demand for hot water supply during the water quality maintenance operation, the hot water in the hot water storage tank can be quickly brought to the water quality maintenance temperature while enabling appropriate hot water supply in a state where high-quality water is heated to the target hot water temperature. Since it becomes possible to heat, it has become possible to provide a hot water storage type hot water supply heat source device capable of appropriately performing the water quality maintenance operation.

In addition to the third feature configuration, the fourth feature configuration is
The control means is configured to determine a hot water replacement state in which hot water in the hot water storage tank is replaced in a form in which water is supplied to the hot water storage tank through the water supply passage and hot water in the hot water storage tank is sent out through the hot water supply passage. The hot water storage tank is configured such that the temperature of the hot water is lower than the set water quality maintenance temperature and the state in which the hot water replacement state is not discriminated continues for the set time for timing discrimination and the water quality maintenance operation timing is determined. Features a point.

  That is, the control means monitors the time during which the temperature of the hot water in the hot water storage tank is lower than the set water quality maintenance temperature and does not determine the hot water replacement state, and the duration is set for the timing determination. When the time is reached, it is determined that the water quality maintenance operation timing is reached.

In other words, if the hot water temperature in the hot water storage tank is lower than the set water quality maintenance temperature and the hot water in the hot water storage tank is not replaced for a long time, the water quality may deteriorate.
Therefore, as the set time for timing determination, the hot water in the hot water storage tank continues to be in a state where the hot water in the hot water storage tank is not replaced when the temperature of the hot water in the hot water storage tank is lower than the set water quality maintenance temperature. When there is a fear, it is set to a time as short as possible while it is the time for the water quality maintenance operation to be executed. When the state in which the temperature of the hot water in the hot water storage tank is lower than the set water quality maintenance temperature and the hot water replacement state is not determined continues for the timing determination set time, it is determined that the water quality maintenance operation timing has been reached, and the water quality is determined. By performing the maintenance operation, it is necessary to execute the water quality maintenance operation in which the water quality of the hot water storage tank may be deteriorated while avoiding frequent execution of the water quality maintenance operation. It is possible to carry out water quality maintenance operation at the right time.

  Therefore, even if hot water having a temperature lower than the water quality maintenance temperature is continuously stored in the hot water storage tank without being replaced while avoiding frequent water quality maintenance operation, When there is a possibility that the quality of the hot water will deteriorate, the water quality maintenance operation can be appropriately executed to maintain the quality of the hot water in the hot water storage tank.

In addition to any of the first to fourth feature configurations described above, the fifth feature configuration is
The heating means is configured to heat the hot water in the hot water storage tank with heat generated from the combined heat and power supply device;
The control means generates electric power according to the electric power load during execution of normal operation, and generates electric power larger than the electric power load to generate surplus electric power during execution of the water quality maintenance operation. Configured to control the operation of the co-feeder;
An electric heater for converting the surplus power into heat for storing hot water in the hot water storage tank is provided at least until the hot water in the entire hot water storage tank reaches the set water quality maintenance temperature or higher during execution of the water quality maintenance operation. It is characterized by that.

That is, the control means generates electric power according to the electric power load during execution of normal operation, and generates electric power larger than the electric power load to generate surplus electric power during execution of the water quality maintenance operation. Controls the operation of the cogeneration device.
During the execution of the normal operation, the heating means heats the hot water in the hot water storage tank with heat generated from the combined heat and power supply device, and at least the hot water in the entire hot water storage tank during the water quality maintenance operation is performed. The hot water in the hot water storage tank is heated by the heat generated from the combined heat and power supply device by the heating means until the temperature reaches the set water quality maintenance temperature or higher, and the hot water storage device uses the electric heater to generate excess power from the combined heat and power supply device The hot water in the tank is heated.
That is, during the execution of the water quality maintenance operation, the hot water in the hot water storage tank is combined with the heating by the heating means until the hot water in the entire hot water storage tank reaches or exceeds the set water quality maintenance temperature, and the combined heat and power supply device with the electric heater is used. Therefore, it is possible to shorten the time required for the hot water in the entire hot water storage tank to reach the set water quality maintenance temperature or more, and the time required for the water quality maintenance operation can be shortened.
In addition, the hot water in the hot water storage tank is heated by using the surplus power of the combined heat and power device with an electric heater in accordance with the heating by the heating means. It is possible to heat the hot water in the entire hot water storage tank to a temperature higher than the set water quality maintenance temperature, and thus the set water quality maintenance time can be set short. As a result, the time required for the water quality maintenance operation can be shortened.
Accordingly, it is possible to shorten the required time while appropriately executing the water quality maintenance operation.

In addition to any of the first to fifth feature configurations described above, the sixth feature configuration is
The hot water storage tank is configured in a sealed manner, the water supply path is connected to a tank bottom, and the hot water supply path is connected to an upper part of the tank;
The heating means is configured to circulate the hot water in the hot water storage tank through the hot water storage circulation path in such a manner that the hot water taken out from the bottom of the tank is returned to the upper portion of the tank via the heating action portion.

That is, the hot water in the hot water storage tank is taken out from the bottom of the tank, heated by the heating action part, and then returned to the upper part of the tank, and is circulated through the hot water storage circulation path so that the temperature of the hot water storage tank is increased. Hot water is stored in a state of forming a stratification.
And when there is a demand for hot water supply, hot water with a high temperature in the upper layer is sent through the hot water supply channel, and water is supplied to the bottom of the hot water storage tank through the water supply channel, while suppressing disturbance of temperature stratification, Hot water with high temperature can be supplied to the hot water supply location.

  That is, when the hot water is stored in a state where temperature stratification is formed in the hot water storage tank, hot water having a high temperature in the upper layer is sent out through the hot water supply passage so that hot water at the target hot water temperature is supplied to the hot water supply location. It is possible to eliminate the heating by the means, or to reduce the amount of heating, and to reduce the energy consumption of the auxiliary heating means, thereby improving the energy saving performance.

  Therefore, it has become possible to provide a hot water storage type hot water supply heat source device that can appropriately execute the water quality maintenance operation while being excellent in energy saving.

[First Embodiment]
Hereinafter, based on drawing, 1st Embodiment at the time of applying the hot-water supply heat source apparatus concerning this invention to a cogeneration system is described.
FIG. 1 shows a cogeneration system provided with a hot water supply heat source device A according to the present invention. This cogeneration system includes, in addition to the hot water supply heat source device A, a fuel cell G as an example of a combined heat and power supply device, and its An inverter 2 or the like that interconnects the fuel cell G to the commercial power source 1 is provided, and the hot water supply source A is supplied with water through the water supply channel 4 and hot water through the hot water supply channel 3 using heat generated in the fuel cell G. Is configured to store hot water in the hot water storage tank 5 to which the water is discharged.

The commercial power source 1 is connected to a power consuming device 8 such as a television, a refrigerator, or a washing machine via a commercial power supply line 7.
The inverter 2 is configured to convert the output power of the fuel cell G into the same voltage and the same frequency as the power supplied from the commercial power source 1, and the commercial power supply line via the cogeneration supply line 9. 7, the power generated by the fuel cell G is converted into alternating current by the inverter 2, and is supplied to the power consuming device 8 via the cogeneration supply line 9 and the commercial power supply line 7. It is configured to be supplied.

Based on FIG. 1, the hot water supply heat source apparatus A will be described.
The hot water supply heat source device A includes the hot water storage tank 5, a heating unit H as a heating means for heating hot water in the hot water storage tank 5, and auxiliary heating means for heating hot water flowing through the hot water supply passage 3 to a target hot water temperature. A normal water supply state in which water is supplied to the hot water storage tank 5 through the water supply passage 4 and the hot water supply from the hot water storage tank 5 to the hot water supply passage 3 is allowed. Is supplied to the upstream side of the auxiliary heater 19 in the hot water supply path 3, bypassing the hot water storage tank 5 through the tank bypass water supply path 24, and from the hot water storage tank 5 to the hot water supply path 3. A water supply switching three-way valve 25 as a water supply state switching means that can be switched to a tank bypass water supply state that stops the delivery of hot water, a heat source control unit 20 that performs various controls of the hot water supply source A, and the like. A.

In the present embodiment, the hot water storage tank 5 is configured in a sealed manner, the water supply path 4 for supplying tap water is connected to the bottom of the tank, the hot water supply path 3 is connected to the upper part of the tank, and hot water supply (not shown) As hot water is sent from the upper part of the hot water storage tank 5 to the hot water supply path 3 through the hot water supply path 3 by opening the stopper, the water is supplied to the bottom of the hot water storage tank 5 through the water supply path 4. The hot water storage tank 5 is configured to store hot water in a full state.
The heating unit H is configured to circulate hot water in the hot water storage tank 5 through the hot water storage circulation path 12 and return the hot water taken out from the tank bottom to the upper part of the tank, and the hot water storage circulation path 12. An exhaust heat source heat exchanger 14 is provided as a heating portion for heating the flowing hot water with heat generated from the fuel cell G, and hot water is stored in a state where temperature stratification is formed in the hot water storage tank 5. It is constituted as follows.

  Further, in the hot water supply heat source apparatus A, a heat medium is circulated by the heat medium circulation pump 22 through the heat medium circulation path 21 over the heat exchanger 11 for heating and the terminal device 6 for heat radiation, and the terminal device 6 for heat radiation. The heat-dissipating part W for performing the heat-dissipating operation for heating the object to be heated and the heating heat exchanger 11 for the hot water heated by the exhaust heat source heat exchanger 14 and flowing through the hot-water storage circulation path 12 A heating flow path 15 that is supplied to the upper part of the hot water storage tank 5 after passing through, and a heating state in which hot water heated by the exhaust heat source heat exchanger 14 is passed through the heating flow path 15; A heating switching three-way valve 16 that can be switched to a non-heating state that does not flow is provided, and the auxiliary heater 19 is also configured to heat the heat medium circulating in the heat medium circulation path 21 to a target heat medium temperature. It is. Incidentally, as the heat radiating terminal 6, for example, there is a floor heating panel or the like, and in that case, a heating target area as a heating target is heated by the floor heating panel.

  Further, the heat medium circulation path 21 is provided with a terminal bypass circuit 50 for circulating the heat medium by bypassing the heat dissipation terminal 6, and further, the heat dissipation terminal 6 is connected to the heat medium through the terminal bypass circuit 50. A heat medium circulation state switching three-way valve 51 is provided at a connection portion between the heat medium circulation path 21 and the terminal device bypass circuit 50 as a heat medium circulation state switching means that can be switched to a terminal device bypass state to be bypassed.

Hereinafter, each part of the hot water supply heat source apparatus A will be described.
A vacuum breaker 26 is provided above the hot water storage tank 5 to open when the pressure in the hot water storage tank 5 becomes equal to or lower than the set tank internal pressure to prevent a decrease in the pressure in the hot water storage tank 5.
The hot water storage tank 5 is provided with four hot water storage temperature sensors Tt for detecting the temperature of the hot water in the hot water storage tank 5 in a state of being distributed over substantially the entire length in the vertical direction. The temperature of hot water is detected.

  The water supply path 4 is provided with a water supply pressure sensor 27 for detecting the water supply pressure. Incidentally, when the water supply is cut off and the water supply to the hot water storage tank 5 by the water supply channel 4 is stopped, the vacuum breaker 26 is activated, and external air may enter the hot water storage tank 5. The fact that the vacuum breaker 26 is activated and the outside air intrusion state in which the outside air enters the hot water storage tank 5 has occurred is based on the fact that the detected pressure of the feed water pressure sensor 27 is lower than a predetermined set tank feed water pressure. Can be determined.

When the heat radiating portion W is described, the heat radiating portion W operates over the heating heat exchanger 11 and the heat radiating terminal 6 as described above by operating the heat medium circulation pump 22. The heat medium is circulated through the heat medium circulation path 21 and is radiated from the heat medium by the heat radiating terminal 6 so that the heat radiation operation for heating the heating target is performed. The heat dissipating part W is provided with a heat dissipating operation part 23 for instructing start and stop of the heat dissipating operation. When the start of operation is instructed from the heat dissipating operation part 23, the heat medium circulation pump 22 is The heat radiation operation is started by operating, and when the operation stop is commanded from the heat radiation operation operation unit 23, the heat medium circulation pump 22 is stopped and the heat radiation operation is stopped.
Further, a heat medium return temperature sensor Tm for detecting a heat medium return temperature that flows out from the heat radiating terminal 6 and returns to the heating heat exchanger 11 is provided.

  When the auxiliary heater 19 is described further, the auxiliary heater 19 circulates through the hot water supply auxiliary heating portion 19 s for heating the hot water flowing through the hot water supply passage 3 and the heating medium circulation passage 21. A heating auxiliary heating unit 19w (heating auxiliary heating means) for heating the heat medium is provided. The hot water supply auxiliary heating unit 19s and the heating auxiliary heating unit 19w include a heat exchanger h that allows hot water or a heating medium to flow through, a gas burner b that heats the heat exchanger h, and combustion air to the gas burner b. , An inflow temperature sensor (not shown) for detecting the inflow temperature of hot water or heat medium flowing into the heat exchanger h, and detecting the outflow temperature of hot water or heat medium flowing out of the heat exchanger h. An outflow temperature sensor (not shown), a flow rate sensor (not shown) for detecting the flow rate of hot water or heat medium flowing into the heat exchanger h, a combustion control unit (not shown), and the like are configured similarly. In addition, the combustion control units are controlled independently of each other.

The control operation of the combustion control unit of the hot water supply auxiliary heating unit 19s will be briefly described. The detection information of the inflow temperature sensor and the outflow temperature sensor in a state where the flow rate sensor detects a flow rate higher than a set flow rate. When the inflow temperature becomes lower than the target hot water supply temperature, the burner b is combusted, and the combustion amount of the burner b is adjusted so that the outflow temperature becomes the target hot water supply temperature. Even if the combustion amount is adjusted, the burner b is extinguished when the outflow temperature becomes equal to or higher than the target hot water supply temperature. Further, if the flow rate detected by the flow sensor becomes less than the set flow rate during combustion of the burner b, the burner b is extinguished.
The control operation of the combustion control unit of the heating auxiliary heating unit 19w is that the target temperature for heating by the burner b changes from the target hot water supply temperature in the hot water supply auxiliary heating unit 19s to the target heat medium temperature. Except for the difference, the operation is the same as the control operation of the combustion control unit of the hot water supply auxiliary heating unit 19 s, and the description thereof will be omitted.

The tank bypass water supply path 24 is connected to the water supply path 4 and a location upstream of the auxiliary heater 19 in the hot water supply path 3, and the water supply switching three-way valve 25 is connected to the tank bypass water supply path 24 and the A hot water path communication flow path state in which the hot water storage tank 5 side portion and the auxiliary heater 19 side portion of the hot water supply path 3 are connected to the connecting portion with the hot water supply path 3, the tank bypass water supply path 24 and the It is provided so as to be switchable to a tank bypass circuit communication flow path state that communicates with the auxiliary heater 19 side portion in the hot water supply path 3.
That is, switching the water supply switching three-way valve 25 to the hot water supply channel communication channel state corresponds to switching to the normal water supply state, and switching the water supply switching three-way valve 25 to the tank bypass circuit communication channel state. This corresponds to switching to the tank bypass water supply state.

In the state where the water supply switching three-way valve 25 is switched to the normal water supply state, as shown by the thick solid line in FIG. 1, hot water is supplied from the upper part of the hot water storage tank 5 as the hot water tap is opened. While being sent out through the hot water supply path 3, water is supplied to the bottom of the hot water storage tank 5 through the water supply path 4. In that case, when the temperature of the hot water from the upper part of the hot water storage tank 5 is lower than the target hot water supply temperature, the hot water is heated to the target hot water temperature by the hot water auxiliary heating unit 19 s of the auxiliary heater 19. become.
Further, in the state where the water supply switching three-way valve 25 is switched to the tank bypass water supply state, as the hot water tap is opened, the water from the water supply path 4 flows as shown by a thick solid line in FIG. The hot water storage tank 5 is bypassed through the tank bypass water supply passage 24 and supplied to the hot water supply passage 3 so that the water reaches the target hot water supply temperature in the auxiliary heating section 19s for hot water supply of the auxiliary heater 19. Will be heated.

  Instead of the water supply switching three-way valve 25, an opening / closing valve capable of opening / closing the tank bypass water supply passage 24 and an opening / closing capable of opening / closing the upstream side of the connecting portion of the hot water supply passage 3 with the tank bypass water supply passage 24. A water supply state switching means for switching between the hot water supply channel communication channel state and the tank bypass circuit communication channel state by providing a valve and opening one of the on-off valves and closing the other valve; I do not care.

Both ends of the hot water storage circulation path 12 are connected to the bottom and top of the hot water storage tank 5, and the hot water storage circulation path 12 sucks the hot water storage circulation pump 13 against the bottom of the hot water storage tank 5. In addition, the exhaust heat source heat exchanger 14 is provided.
The heat-switching three-way valve 16 having one inlet and two outlets is used to exchange the exhaust heat source heat in the hot water storage circuit 12 using the inlet and one of the two outlets. The heating channel 15 is connected at one end to the remaining outlet of the heating switching three-way valve 16, and is interposed in a portion downstream of the vessel 14 and upstream of the hot water storage tank 5. The other end is connected to the downstream side of the heating switching three-way valve 16 in the hot water storage circulation path 12 and the heating heat exchanger 11 is provided in the middle of the heating flow path 15. is there.

  The heating switching three-way valve 16 has the heating state in which the entire amount of hot water flowing into the inflow port is caused to flow out of the outflow port to which the heating flow channel 15 is connected and passed through the heating flow channel 15; The entire amount of hot water flowing into the inlet is made to flow out of the outlet to which the hot water storage circulation path 12 is connected and can be switched to the non-heated state where it is not passed through the heating passage 15. It is.

That is, when the heating switching three-way valve 16 is switched to the non-heating state, a hot water storage independent operation mode in which the entire amount of hot water heated by the exhaust heat source heat exchanger 14 is stored in the hot water storage tank 5 is executed. it can.
In the hot water storage single operation mode, as shown by a thick solid line in FIG. 1, hot water taken out from the bottom of the hot water storage tank 5 is heated by the exhaust heat source heat exchanger 14, and then the entire amount is stored in the hot water storage. The hot water in the hot water storage tank 5 is circulated through the hot water storage circulation path 12 in a form returned to the upper part of the tank 5, and is stored in the hot water storage tank 5.

Further, when the heating switching three-way valve 16 is switched to the heating state, the entire amount of hot water heated by the exhaust heat source heat exchanger 14 is passed through the heating flow path 15 and the heat exchange for heating. A parallel operation mode is performed in which the heat medium circulating in the heat medium circulation path 21 is heated in the vessel 11 and hot water that has passed through the exhaust heat source heat exchanger 14 is supplied to the hot water storage tank 5 to store hot water. be able to.
In the parallel operation mode, although not shown, the hot water taken out from the bottom of the hot water storage tank 5 is heated by the exhaust heat source heat exchanger 14, and the entire amount passes through the heating heat exchanger 11. After exchanging heat with the heat medium, the hot water in the hot water storage tank 5 is circulated through the hot water storage circulation path 12 and the heating flow path 15 in a form that is returned to the upper part of the hot water storage tank 5. The heat medium circulating in the medium circulation path 21 is heated and stored in the hot water storage tank 5.

The fuel cell G will be further described.
As shown in FIG. 3, the fuel cell G includes a cell stack 30 that generates power by supplying a fuel gas containing hydrogen and an oxygen-containing gas, and a fuel gas generator R that generates fuel gas to be supplied to the cell stack 30. A blower 31 for supplying air as an oxygen-containing gas to the cell stack 30; a cooling water circulation pump 33 for circulating cooling water for cooling the cell stack 30 through a cooling water circulation path 32; and a fuel electrode side discharged from the cell stack 30 The first heat exchanger 34 for recovering exhaust heat that recovers the retained heat of the exhaust gas into the cooling water flowing through the cooling water circulation path 32, the retained heat of the oxygen electrode side exhaust gas discharged from the cell stack 30, and the generation of the fuel gas A second heat recovery heat exchanger 35 for recovering the retained heat of the combustion exhaust gas discharged from the part R into the cooling water flowing through the cooling water circulation path 32, and the front It includes a fuel cell controller 36 or the like that governs various controls of the fuel cell G are constituted.

Hereinafter, each part constituting the fuel cell G will be described.
Since the cell stack 30 is well known, detailed description and illustration are omitted, and briefly described. The cell stack 30 is arranged by distributing an oxygen electrode and a fuel electrode on both sides of a polymer film as an electrolyte layer. A plurality of solid polymer cells are provided in a stacked state, and the supplied fuel gas is distributed and supplied to the fuel electrode of each cell, and the supplied reaction air is distributed to the oxygen electrode of each cell. In this configuration, power is generated by an electrochemical reaction between hydrogen and oxygen in each cell.

The fuel gas generation unit R includes a desulfurizer 37 that desulfurizes a hydrocarbon-based raw fuel gas such as a supplied city gas (for example, a natural gas-based city gas), and a desulfurization source that is supplied from the desulfurizer 37. A reformer 38 for generating a reformed gas mainly composed of hydrogen by reforming the fuel gas and steam supplied from a steam generator (not shown) by heating the reforming burner 38b. The carbon monoxide in the reformed gas supplied from the reformer 38 is converted to carbon dioxide with steam, and the carbon monoxide in the reformed gas supplied from the shifter 39 is supplied separately. A carbon monoxide remover 40 that selectively oxidizes with selective oxidization air is provided, and the carbon monoxide in the reformed gas is reduced by the conversion treatment and the selective oxidation treatment. Below) reformed gas It is arranged to formed.
Then, the reformed gas obtained by reducing carbon monoxide by the modification process and the selective oxidation process is supplied to the cell stack 30 as the fuel gas.
The supply of the raw fuel gas to the desulfurizer 37 is interrupted, and a raw material gas control valve 43 for adjusting the supply amount is provided, and the supply amount of the raw fuel gas is adjusted by the raw material gas control valve 43. Thus, the amount of fuel gas supplied to the cell stack 30 is adjusted to adjust the output power of the cell stack 30.

After the fuel electrode side exhaust gas discharged from the fuel electrode of each cell of the cell stack 30 passes through the first exhaust heat recovery heat exchanger 34 through the fuel electrode side exhaust gas passage 41, the reforming The combustion air is supplied to the burner 38b, the combustion air is supplied to the reforming burner 38b by the blower 31, and the fuel electrode side exhaust gas is burned by the reforming burner 38b. Heating is performed so that the reforming reaction is possible.
The oxygen electrode exhaust gas discharged from the oxygen electrode of each cell of the cell stack 30 is mixed with the combustion exhaust gas discharged from the reforming burner 38b, and the mixed exhaust gas is mixed with the second exhaust heat recovery heat exchanger. The mixed exhaust gas passage 42 is connected to the reforming burner 38b, the cell stack 30, and the second exhaust heat recovery heat exchanger 35 so as to be discharged outside the apparatus after passing through the apparatus 35.

  As shown in FIG. 1, the cooling water circulation path 32 cools the cell stack 30 and discharges the cooling water discharged from the cell stack 30 to the exhaust heat source heat exchanger 14 and the second exhaust. The heat recovery heat exchanger 35 and the first exhaust heat recovery heat exchanger 34 are passed through in this order to be returned to the cell stack 30, and as the heat generated from the fuel cell G, the combustion exhaust gas, The retained heat of each of the oxygen electrode side exhaust gas and the fuel electrode side exhaust gas and the power generation reaction heat generated from the cell stack 30 are recovered in cooling water, and the cooling water is passed to the exhaust heat source heat exchanger 14. In the exhaust heat source heat exchanger 14, the cooling water recovered from the heat generated from the fuel cell G and the hot water flowing through the hot water storage circuit 12 are heat-exchanged to cool the cooling water. And add the hot water It is arranged to.

Further, in the cooling water circulation path 32, a radiator that cools the flowing cooling water at a location downstream of the exhaust heat source heat exchanger 14 and upstream of the second exhaust heat recovery heat exchanger 35. 44 is provided.
Furthermore, it is heated by the cooling water temperature sensor Tw for detecting the temperature of the cooling water discharged from the cell stack 30 and flowing through the cooling water circulation path 32, and the exhaust heat source heat exchanger 14 for the hot water storage. A tank supply temperature sensor Te for detecting the temperature of hot water flowing through the circulation path 12 is provided.

Next, the fuel cell control unit 36 will be described.
When the start of operation is commanded from a fuel cell operation unit (not shown), the fuel cell control unit 36 opens the raw fuel gas control valve 43 to supply the raw fuel gas to the fuel gas generation unit R, and The blower 31 is operated to start the operation of the fuel cell G. When the stop of the operation is instructed from the fuel cell operation unit, the raw fuel gas control valve 43 is closed to generate the fuel gas. The supply of the raw fuel gas to the part R is stopped, and the blower 31 is stopped to stop the operation of the fuel cell G.
The fuel cell control unit 36 performs a power load following operation that changes and adjusts the output power according to the power consumption of the power consuming device 8, that is, the power load, during the operation of the fuel cell G. It is configured. In the power load following operation, the fuel cell control unit 36 determines that the supply amount of the raw fuel gas corresponds to the detected power of a power measurement unit (not shown) that measures the power output through the cogeneration supply line 9. In order to adjust the cooling water circulation amount so that the detected temperature of the cooling water temperature sensor Tw becomes the set cooling water temperature, the opening degree of the raw fuel gas control valve 43 is adjusted so that the set supply amount becomes equal. The operation of the water circulation pump 33 is controlled, and the hot water circulation pump 13 is controlled to adjust the hot water circulation amount so that the temperature detected by the tank supply temperature sensor Te becomes a preset target hot water storage temperature. It is. Incidentally, the target hot water storage temperature is set to 65 ° C., for example.
The fuel cell control unit 36 adjusts the radiator fan of the radiator 44 when the detected temperature of the cooling water temperature sensor Tw exceeds the set cooling water temperature with the cooling water circulation flow rate adjusted to the set maximum flow rate. The radiator 44 is operated to dissipate heat, and the operation of the radiator fan 44f is controlled so that the detected temperature becomes the set coolant temperature.

Hereinafter, the heat source control unit 20 will be described.
The heat source control unit 20 is configured to perform a water quality maintenance operation for maintaining the quality of the hot water in the hot water storage tank 5. Furthermore, the heat source control unit 20 determines whether or not it is a water quality maintenance operation timing at which it is necessary to perform a water quality maintenance operation, and performs a normal operation until the water quality maintenance operation timing is reached. At the operation timing, the water quality maintenance operation is executed.

In the normal operation, the heat source control unit 20 maintains the water supply switching three-way valve 25 in the normal water supply state and supplies water to the bottom of the hot water storage tank 5 through the water supply path 4. While the heat dissipating part W is stopped, the heating switching three-way valve 16 is set in the non-heated state and operated in the hot water storage single operation mode. During operation of the heat dissipating part W, the heating switching three-way valve 16 is operated in the heated state. Thus, it is configured to operate in the parallel operation mode.
As shown by a thick solid line in FIG. 1, when the hot water tap is opened during the normal operation, hot water is sent from the upper part of the hot water storage tank 5 through the hot water supply passage 3 and through the water supply passage 4. Water is supplied to the bottom of the hot water storage tank 5.

  Further, in the water quality maintenance operation, the heat source control unit 20 is in a state where the hot water in the entire hot water storage tank 5 is equal to or higher than the set water quality maintenance temperature in a state where the water supply switching three-way valve 25 is switched to the tank bypass water supply state, for example. Is operated to operate the heating unit H so as to continue the set water quality maintenance time.

The water quality maintenance operation will be explained.
The set holding temperature is set to the same temperature as the set water quality maintenance temperature or a temperature higher than the set water quality maintenance temperature. In the water quality maintenance operation, the hot water heated to the target hot water storage temperature in the exhaust heat source heat exchanger 14 in the state where the water supply switching three-way valve 25 is switched to the tank bypass water supply state, the hot water storage tank 5, and when all of the four hot water storage temperature sensors Tt detect a temperature not lower than the set holding temperature, the hot water in the entire hot water storage tank 5 is not lower than the set water quality maintenance temperature. As described above, the water supply switching three-way valve 25 is turned on until the state where all of the four hot water storage temperature sensors Tt detect the temperature equal to or higher than the set holding temperature continues for the set water quality maintenance time. The state where the tank bypass water supply state is maintained. Incidentally, the set water quality maintenance temperature is set to 60 ° C., for example, and in this embodiment, the set retention temperature is set to 60 ° C. which is the same temperature as the set water quality maintenance temperature. Is set to 60 ° C., the set water quality maintenance time is set to about 5 minutes, for example.

  That is, during the water quality maintenance operation, as shown by a thick solid line in FIG. 2, the hot water taken out from the bottom of the hot water storage tank 5 is heated by the exhaust heat source heat exchanger 14, and then the total amount is The hot water in the hot water storage tank 5 is circulated through the hot water storage circulation path 12 in a form returned to the upper part of the hot water storage tank 5, and hot water heated to the target hot water storage temperature is stored in the hot water storage tank 5. When the hot water tap is opened during the water quality maintenance operation, the water from the water supply channel 4 is supplied to the hot water supply channel 3 by bypassing the hot water storage tank 5 through the tank bypass water supply channel 24, and Water is heated so as to reach the target hot water supply temperature in the hot water supply auxiliary heating section 19 s of the auxiliary heater 19.

The heat source control unit 20 assists heating in a state in which the heat medium is circulated through the heat medium circulation path 21 at least until the hot water in the entire hot water storage tank 5 reaches or exceeds the set water quality maintenance temperature during execution of the water quality maintenance operation. The auxiliary heating operation for operating the heating unit 19w is performed.
That is, in the auxiliary temperature raising operation, the heating switching three-way valve 16 is set in the heating state in the hot water storage circuit 12, and hot water heated by the heating unit H is supplied to the hot water storage tank 5 through the heating heat exchanger 11. On the other hand, the heating medium circulating in the heating medium circulation path 21 by the heating medium circulation pump 22 in the heating medium circulation path 21 is heated by the heating auxiliary heating unit 19w and supplied to the heating heat exchanger 11. Like that.

  Therefore, in the auxiliary heating operation, in the heating heat exchanger 11, the hot water circulating in the hot water storage circuit 12 is heated by heat exchange with the high-temperature heat medium circulating in the heat medium circuit 21, and the target hot water storage is performed. Hot water heated to the temperature is stored in the hot water storage tank 5.

  Further, the heat source control unit 20 may be configured to always perform the auxiliary temperature raising operation during the water quality maintenance operation, but the temperature detected by the tank supply temperature sensor Te is less than the water quality maintenance temperature. The auxiliary heating operation is executed only during the period of time, and while the temperature detected by the tank supply temperature sensor Te is equal to or higher than the water quality maintenance temperature, the heating switching three-way valve 16 is set in the non-heated state in the hot water storage circuit 12 As described above, the hot water heated to the target hot water storage temperature by the exhaust heat source heat exchanger 14 may be supplied to the hot water storage tank 5 as it is.

  Furthermore, the heat medium operation control unit 20 is configured to switch the heat medium circulation state switching three-way valve 51 to the terminal device bypass state during the execution of the auxiliary temperature raising operation. Therefore, during the execution of the auxiliary heating operation, the heating medium heated by the auxiliary heating unit 19w for heating in the heating medium circulation path 21 is not supplied to the heating terminal 6. There is no unexpected heating.

Hereinafter, the structure for discriminating whether or not the heat source control unit 20 is the water quality maintenance operation timing will be described.
That is, the heat source control unit 20 supplies hot water to the hot water storage tank 5 through the water supply passage 4 and hot water in the hot water storage tank 5 is replaced with hot water from the hot water storage tank 5 in a form in which hot water from the hot water storage tank 5 is sent out through the hot water supply passage 3. It is configured to determine the state.
And when the state where the temperature of the hot water in the hot water storage tank 5 is lower than the set water quality maintenance temperature and the hot water replacement state is not discriminated continues for the set time for timing judgment, the heat source control unit 20 becomes the water quality maintenance operation timing. It is configured to discriminate.

Incidentally, the detected flow rate of the flow rate sensor of the hot water supply auxiliary heating portion 19s of the auxiliary heater 19 in a state where the water supply switching three-way valve 25 is in the normal water supply state is integrated, and the integrated flow rate is previously stored in the hot water storage. While the set tank capacity set as the total capacity of the tank 5 is not reached, it is determined that the hot water is not changed, and when the integrated flow rate reaches the set tank capacity, it is determined that the hot water is changed. It is configured.
On the basis of the detection information of the four hot water storage temperature sensors Tt, when the temperature detected by at least one hot water storage temperature sensor Tt is lower than the set water quality maintenance temperature, the temperature of the hot water in the hot water storage tank 5 is It is comprised so that it may discriminate | determine that it is the low hot water storage temperature state lower than preset water quality maintenance temperature.
Then, when the low hot water storage temperature state is reached, the integration of the detected flow rate of the flow sensor is started, and simultaneously, the measurement of the low hot water storage temperature state duration in which the low hot water storage temperature state continues is started, and the measurement time is If the integrated flow rate reaches the set tank capacity before reaching the timing determination set time, the integrated detection flow rate and measurement time are reset, and the detection flow rate integration and measurement of the low hot water storage temperature state duration time are newly started. Alternatively, when all the detected temperatures of the four hot water storage temperature sensors Tt are equal to or higher than the set water quality maintenance temperature, the integrated detection flow rate and measurement time are reset, and when the low hot water storage temperature state is reached, the detection flow rate is newly integrated and Accumulation of the detected flow rate and measurement of the low hot water temperature state duration are repeated in the form of starting the measurement of the low hot water temperature state duration. And when resetting the measurement time of the low hot water storage temperature state time until the timing determination set time is reached, the hot water temperature in the hot water storage tank 5 is lower than the set water quality maintenance temperature and the hot water replacement state is set. If the state not determined does not continue for the timing determination set time, it is determined that it is not the water quality maintenance operation timing, and when the measurement time of the low hot water storage temperature state duration reaches the timing determination set time, the hot water storage tank 5 If the hot water temperature is lower than the set water quality maintenance temperature and the state in which the hot water replacement state is not discriminated continues for the set time for timing discrimination, it is discriminated that the water quality maintenance operation timing is reached.

  By the way, the set time for the timing determination is about half of the shortest time that the water quality is considered to be deteriorated by storing the hot water at a temperature lower than the set water quality maintenance temperature in the hot water storage tank 5 without being replaced. Set the time. By setting the timing determination setting time in this manner, the water quality maintenance operation in which the quality of the hot water in the hot water storage tank 5 may be lowered while avoiding frequent execution of the water quality maintenance operation. It is possible to perform water quality maintenance operation when it is necessary to perform the operation.

That is, for example, due to travel or the like, the operation of the fuel cell G and the hot water supply heat source device A is stopped, the hot water in the hot water storage tank 5 is not heated, and hot water is not sent from the hot water storage tank 5 through the hot water supply passage 3. If the state continues, it may be determined that the water quality maintenance operation timing is reached.
Further, when the normal operation is executed in the parallel operation mode, hot water having a temperature lower than the set water quality maintenance temperature may be supplied to the hot water storage tank 5, so the normal operation is performed in the parallel operation mode. If the operation is executed and the state where hot water is not sent from the hot water storage tank 5 through the hot water supply passage 3 continues, it may be determined that the water quality maintenance operation timing is reached.
In addition, when the fuel cell G is operated at a low load with a small output power, the amount of generated heat is small and the hot water may not be heated to the target hot water temperature in the exhaust heat source heat exchanger 14. As described above, when the fuel cell G is operated at a low load and no hot water is sent from the hot water storage tank 5 through the hot water supply passage 3, it may be determined that the water quality maintenance operation timing is reached.

In addition, when the vacuum breaker 26 is actuated in response to the water cut off and an outside air intrusion state occurs in which the outside air enters the hot water storage tank 5, the quality of the hot water in the hot water storage tank 5 may be deteriorated.
Therefore, when the heat source control unit 20 determines that the outside air intrusion state has occurred based on the detected pressure of the feed water pressure sensor 27 being lower than the set tank feed water pressure, the water quality maintenance operation timing is reached. It is configured to discriminate.

When the hot water supply heat source device A is installed and the hot water storage tank 5 is filled with water for the first time, or when the water in the hot water storage tank 5 is replaced by maintenance or the like, the temperature of the hot water in the hot water storage tank 5 is changed. The water quality is likely to be low.
Therefore, a water quality maintenance operation command switch (not shown) for commanding execution of the water quality maintenance operation is provided, and the heat source control unit 20 is commanded to execute the water quality maintenance operation by the water quality maintenance operation command switch. And the water quality maintenance operation timing is determined.

Next, a description will be given of a control operation in which the heat source control unit 20 operates by switching the operation state to the normal operation in the hot water storage single mode, the normal operation in the parallel operation mode, and the water quality maintenance operation.
The heat source control unit 20 is based on the heat medium return temperature detected by the heat medium return temperature sensor Tm, and when the heat medium return temperature is equal to or lower than the set heat medium return temperature, the heat radiating unit W is stopped. When it is determined that there is a heat medium return temperature higher than the set heat medium return temperature, it is determined that the heat dissipating part W is in a heat dissipating operation.
That is, when an operation start is instructed from the heat radiation operation operation unit 23 and the heat medium circulation pump 22 is operated and the heat medium circulates in the heat medium circulation path 21, the temperature of the heat medium becomes the target heat medium temperature. Is lower than the heating medium, the heating medium is heated to the target heating medium temperature in the heating auxiliary heating unit 19w of the auxiliary heater 19, and the detected temperature of the heating medium return temperature sensor Tm is set to the set heating medium return. It becomes higher than temperature and it is discriminate | determined that the driving | operation of the said thermal radiation part W was started. Further, when the operation stop is instructed from the heat radiation operation operation unit 23 and the heat medium circulation pump 22 is stopped and the circulation of the heat medium in the heat medium circulation path 21 is stopped, the temperature of the heat medium is decreased, It is determined that the detected temperature of the heat medium return temperature sensor Tm is equal to or lower than the set heat medium return temperature and the operation of the heat radiating unit W is stopped.

  Then, in a state where the heat source control unit 20 determines that it is not the water quality maintenance operation timing, the heat medium return temperature detected by the heat medium return temperature sensor Tm is equal to or lower than the set heat medium return temperature. While it is determined that the heat dissipating part W is stopped, the normal operation is performed in the hot water storage single operation mode in which the water supply switching three-way valve 25 is in the normal water supply state and the heating switching three-way valve 16 is in the non-heating state. And during the normal operation in the hot water storage single operation mode, the heat medium return temperature detected by the heat medium return temperature sensor Tm becomes higher than the set heat medium return temperature, and the heat radiating unit When it is determined that the heat release operation of W has been started, the heating switching three-way valve 16 is switched to the heating state, the hot water storage single operation mode is switched to the parallel operation mode, and the communication in the parallel operation mode is performed. If it is determined that the heat medium return temperature detected by the heat medium return temperature sensor Tm is equal to or lower than the set heat medium return temperature and the heat release operation of the heat radiating unit W is stopped during the operation, the heating The switching three-way valve 16 is switched to the non-heating state to switch from the parallel operation mode to the hot water storage single operation mode.

When determining that the water quality maintenance operation timing has been reached, the heat source control unit 20 switches the water supply switching three-way valve 25 to the tank bypass water supply state, and when the heating switching three-way valve 16 is in the non-heating state, When the heating switching three-way valve 16 is in the heating state, the heating switching three-way valve 16 is switched to the non-heating state, and all the four hot water storage temperature sensors Tt detect a temperature equal to or higher than the set holding temperature. Further, the heating switching three-way valve 16 is maintained in the non-heated state until the state continues for the set water quality maintenance time, and when the set water quality maintenance time has elapsed, the water supply switching three-way valve 25 is switched to the normal water supply. Depending on whether or not the heat dissipating part W is in a heat dissipating operation, the heating switching three-way valve 16 continues to be in the non-heating state or the heating switching three-way valve 16 is It switched to the heat state.
When the water quality maintenance operation timing is reached while the fuel cell G is stopped, the operation of the fuel cell G is started and the hot water storage circulation pump 13 is operated. Hot water storage will be started.

  When the water quality maintenance operation is executed in this way, all the hot water in the hot water storage tank 5 and the hot water storage circuit 12 is maintained at the set water quality at a temperature equal to or higher than the set water quality maintenance temperature (for example, 60 ° C.). Since the time is maintained (for example, 5 minutes), the quality of the hot water can be maintained.

  That is, as shown in FIG. 1, the heat source control unit 20 and the fuel cell control unit 36 constitute a control means C, and the control means C stores hot water in the hot water storage tank 5 at a target hot water storage temperature. Control for controlling the operation of the heating unit H, control of the operation of the water supply switching three-way valve 25, determination of whether or not it is the water quality maintenance operation timing, and the heating unit H to execute the water quality maintenance operation Control to be operated, determination of whether or not the hot water is changed, and the like are executed.

  In order to continue the operation of the fuel cell G during the water quality maintenance operation in which the hot water in the hot water storage circuit 12 is maintained at the set water quality maintenance temperature or higher, the radiator 44 is operated and the cooling water circuit 32 is caused to flow. It is necessary to cool the cooling water sufficiently.

Furthermore, in the above-described embodiment, the radiator 44 is provided in the cooling water circulation path 32 on the fuel cell G side. Separately, the radiator 44 is provided in the hot water storage circulation path 12 more than the exhaust heat source heat exchanger 14. You may provide in the location downstream from the said hot water storage tank 5 in the upstream.
When the radiator 44 is provided in the hot water storage circuit 12 as described above, in order to continue the operation of the fuel cell G during the water quality maintenance operation, all the hot water in the hot water storage circuit 12 is set to the set water quality. In such a case, during the water quality maintenance operation, the operation of the fuel cell G and the radiator 44 is stopped and all the hot water in the hot water storage circuit 12 is set to the set water quality. You may comprise so that it may hold | maintain above maintenance temperature.

[Second Embodiment]
Hereinafter, based on drawing, 2nd Embodiment at the time of applying the hot-water supply heat source apparatus concerning this invention to a cogeneration system is described.
In the second embodiment, the same components as those in the first embodiment and the components having the same functions are denoted by the same reference numerals in order to avoid redundant description, and the description thereof is mainly omitted. A different configuration will be described.
As shown in FIG. 4, in the second embodiment, in addition to the first embodiment, during the execution of the water quality maintenance operation, at least the hot water in the entire hot water storage tank 5 is equal to or higher than the set water quality maintenance temperature. In the meantime, an electric heater 28 is provided for converting surplus electric power, which will be described later, of the fuel cell G into heat for storing hot water in the hot water storage tank 5.

The electric heater 28 will be further described.
The electric heater 28 is composed of a plurality of electric heaters, and is downstream of the fuel cell G (specifically, the cell stack 30) in the cooling water circulation path 32 and more than the exhaust heat source heat exchanger 14. The cooling water of the fuel cell G flowing through the upstream portion is provided to be heated, and is connected to the cogeneration supply line 9 via an operation switch 29 corresponding to each electric heater.
The power consumption of the electric heater 28 is adjusted by adjusting the number of the operation switches 29 to be turned on.

Next, the heat source control unit 20 and the fuel cell control unit 36 will be described.
The heat source control unit 20 and the fuel cell control unit 36 are configured to be able to communicate control information with each other, and the fuel cell control unit 36 is performing the normal operation from the heat source control unit 20 or Information indicating whether the water quality maintenance operation is being performed is communicated. The target hot water storage temperature, the set water quality maintenance temperature, the set holding temperature, and the set water quality maintenance time are set in the same manner as in the first embodiment.

The heat source control unit 20 is configured in the same manner as in the first embodiment except that the switching control of the heat switching three-way valve 16 in the first embodiment is omitted.
That is, the heat source control unit 20 determines whether or not it is a water quality maintenance operation timing at which it is necessary to perform a water quality maintenance operation in order to maintain the quality of the hot water in the hot water storage tank 5, and the water quality maintenance operation timing is determined. During this period, normal operation is performed, and when the water quality maintenance operation timing comes, the water quality maintenance operation is executed.

  When the control operation of the heat source control unit 20 is described, the heat source control unit 20 maintains the water supply switching three-way valve 25 in the normal water supply state in the normal operation, and when the water quality maintenance operation timing is reached, The water supply switching three-way valve 25 is switched to the tank bypass water supply state, and all of the four hot water storage temperature sensors Tt are in a state of detecting a temperature equal to or higher than the set holding temperature. When the time continues, the water supply switching three-way valve 25 is configured to switch to the normal water supply state.

In addition, since the structure for discriminating whether the said heat source control part 20 is the said water quality maintenance operation timing is the same as that of said 1st Embodiment, the description is abbreviate | omitted.
That is, in the second embodiment, the operation of the fuel cell G and the hot water supply heat source device A is stopped due to travel or the like, the hot water in the hot water storage tank 5 is not heated, and the hot water supply path 3 is connected to the hot water supply path 3. When the state where hot water is not sent through continues or when the fuel cell G is operated at a low load with low output power and the state where hot water is not sent from the hot water storage tank 5 through the hot water supply passage 3 continues, the water quality maintenance operation is performed. It may be determined that it is time.
Further, it is determined that the outside air intrusion state has occurred based on the detected pressure of the water supply pressure sensor 27 being lower than the set tank water supply pressure, and it is determined that the water quality maintenance operation timing is reached. When execution of the water quality maintenance operation is commanded by the maintenance operation command switch, it is determined that the water quality maintenance operation timing is reached.

  While the information indicating that the normal operation is being performed is communicated from the heat source control unit 20, the fuel cell control unit 36 performs a power load following operation for changing and adjusting the output power according to the power load. While the information indicating that the water quality maintenance operation is being performed is communicated from the heat source control unit 20, the output power of the fuel cell G is set to the maximum value in the adjustment range. A maximum output operation for controlling the operation of the switch 29 is executed so as to adjust the output power and to consume the surplus power of the fuel cell G by the electric heater 28.

Incidentally, in the load following operation, when the power load exceeds the set maximum output power, the output power of the fuel cell G is adjusted to the set maximum output power, and the fuel cell G of the power load is out of the power load. Insufficient output power will be supplied from the commercial power source 1, and during execution of the maximum output operation, if the power load is smaller than the set maximum output power, surplus power will be generated. Become.
That is, the fuel cell control unit 36 is configured to control the operation of the fuel cell G so as to generate electric power larger than the electric power load so as to generate surplus electric power during the execution of the water quality maintenance operation. It is.

The control operation of the fuel cell control unit 36 will be described.
While the information indicating that the normal operation is being performed is communicated from the heat source control unit 20, the supply amount of the raw fuel gas becomes a set supply amount corresponding to the detected power of the power measurement unit. The raw fuel gas control valve 43 is controlled to execute the power load following operation.
When information indicating that the water quality maintenance operation is being performed is communicated from the heat source control unit 20 during the power load following operation, the supply amount of the raw fuel gas is set to the set maximum output power. The raw fuel supply amount adjustment valve 43 is controlled so as to obtain a set supply amount according to the control, and the operation of the switch 29 is controlled so that surplus power of the fuel cell G is consumed by the electric heater 28. When the information indicating that the normal operation is being executed is transmitted from the heat source control unit 20 during the execution of the maximum output operation, the operation is switched to the power load following operation. . The cooling water circulation pump 33 and the hot water circulation pump 13 are controlled in the same manner as in the first embodiment, and the description thereof is omitted.

  That is, as shown in FIG. 4, in the water quality maintenance operation, the cooling water of the fuel cell G is heated by the heat generated by the fuel cell G and is heated by the electric heater 28 using the surplus power of the fuel cell G. However, the hot water that was passed through the exhaust heat source heat exchanger 14 and circulated through the cooling water circulation path 32 and was taken out from the bottom of the hot water storage tank 5 was heated by the exhaust heat source heat exchanger 14. Thereafter, the hot water in the hot water storage tank 5 is circulated through the hot water storage circulation path 12 in a form returned to the upper part of the hot water storage tank 5, and the hot water heated to the target hot water storage temperature is stored in the hot water storage tank 5. The When the hot water tap is opened during the water quality maintenance operation, the water from the water supply channel 4 is supplied to the hot water supply channel 3 by bypassing the hot water storage tank 5 through the tank bypass water supply channel 24, and Water is heated so as to reach the target hot water supply temperature in the hot water supply auxiliary heating section 19 s of the auxiliary heater 19.

  In the second embodiment, in the water quality maintenance operation, it becomes possible to give a larger amount of heat to the cooling water of the fuel cell G than in the first embodiment. It becomes possible to shorten the time until the temperature is higher than the temperature, that is, the time until the temperature is higher than the set water quality maintenance temperature, and the time required for the water quality maintenance operation can be shortened.

  As shown in FIG. 4, also in the second embodiment, the heat source control unit 20 and the fuel cell control unit 36 constitute a control means C, and the control means C is used as a target for the hot water storage tank 5. Control for controlling the operation of the heating unit H so as to store hot water at the hot water storage temperature, control of the operation of the water supply switching three-way valve 25, determination of whether or not it is the water quality maintenance operation timing, and water quality maintenance operation are executed. Control for operating the heating unit H, determining whether or not the hot water is switched, and generating electric power according to the power load during execution of normal operation, and surplus power during execution of the water quality maintenance operation Control for controlling the operation of the fuel cell G so as to generate electric power larger than the electric power load is performed.

[Another embodiment]
Next, another embodiment will be described.
(A) In each of the above embodiments, the case where the hot water storage tank 5 is configured to be sealed is illustrated, but the hot water storage tank 5 is opened and the hot water in the hot water storage tank 5 is sent out through the hot water supply passage 3. A hot water supply pump may be provided. In this case, the water supply state switching means is configured to include the hot water supply pump in addition to the water supply switching three-way valve 25, and the hot water storage tank 5 can switch the hot water supply by switching the operation and stop of the hot water supply pump. The state is switched between a state in which hot water is allowed to be sent to the passage 3 and a state in which the hot water is stopped.

(B) In the first embodiment, the control of the hot water circulation pump 13 for adjusting the hot water circulation amount so as to heat the hot water to the target hot water temperature in the exhaust heat source heat exchanger 14; That is, the fuel cell control unit 36 is configured to control the operation of the heating unit H, but may be configured to be performed by the heat source control unit 20. In this case, the control means C is configured only by the heat source control unit 20.
In said 2nd Embodiment, although illustrated about the case where the heat source control part 20 which controls the driving | operation of the said hot water supply heat source apparatus A and the fuel cell control part 36 which controls the driving | operation of the said fuel cell G were each comprised separately, One controller for controlling the operation of each of the hot water supply heat source device A and the fuel cell G may be provided. In this case, the control means C is configured by the one control unit.

(C) In the first embodiment described above, the combustion controller of each of the auxiliary hot water heater 19s and the auxiliary heater 19w for heating is omitted in each of the combustion controllers. The control means C may be configured to control the operations of the hot water supply auxiliary heating unit 19s and the heating auxiliary heating unit 19w.

(D) In each of the above embodiments, the installation location of the water supply switching three-way valve 25 can be changed to a connection portion between the water supply channel 4 and the tank bypass water supply channel 24.

(E) The target hot water storage temperature and the set water quality maintenance temperature can be changed in various ways other than those exemplified in the above embodiments under the condition that the set water quality maintenance temperature is set to be equal to or lower than the target hot water storage temperature.
Further, in each of the above embodiments, the case where the set holding temperature is set to the same temperature as the set water quality maintenance temperature is exemplified, but the set holding temperature may be set to a temperature higher than the set water quality maintenance temperature. And, as the set retention temperature is set higher, the water quality of the hot water storage tank 5 can be maintained, but the set water quality maintenance time can be set shorter and the time required for the water quality maintenance operation is shortened. It becomes possible to do.
When the set holding temperature is set to a temperature higher than the set water quality maintenance temperature, it is necessary to supply hot water to the hot water storage tank 5 during the water quality maintenance operation, which is higher than that during normal operation. The target hot water storage temperature for operation and the target hot water storage temperature for water quality maintenance operation are set in a state where the water temperature maintenance operation becomes higher.
For example, when the set holding temperature is set to 70 ° C., the target hot water storage temperature for normal operation is set to 65 ° C. as in the above embodiments, and the target hot water storage temperature for water quality maintenance operation is For example, the temperature is set to about 72 ° C. so that hot water of 70 ° C. or higher can be supplied to the tank 5.
Incidentally, when the set holding temperature is set to 70 ° C., the set water quality maintenance time can be set to a short time of about 1 minute, for example.
In the second embodiment, in the water quality maintenance operation, it becomes possible to give more heat to the cooling water of the fuel cell G than in the first embodiment. Therefore, the embodiment in which the set holding temperature is set to a temperature higher than the set water quality maintenance temperature is preferably applied in the second embodiment.

(F) There are various ways of determining the water quality maintenance operation timing other than those exemplified in the above embodiment.
For example, when the time during which the operation of the fuel cell G is stopped reaches a predetermined set time, or the low output operation state in which the output power of the fuel cell G is lower than the set output continues for the predetermined set time, the water quality maintaining operation timing You may make it discriminate | determine.
Or you may make it discriminate | determine that it becomes a water quality maintenance driving | operation timing regularly.

(G) The generated heat of the fuel cell G to be recovered in the hot water by the exhaust heat source heat exchanger 14 is the combustion exhaust gas, the oxygen electrode side exhaust gas, and the fuel electrode as exemplified in the above embodiment. It is not limited to the retained heat of each side exhaust gas and the power generation reaction heat generated from the cell stack 30.
For example, any one, any two, or all of the retained heat of the combustion exhaust gas, the oxygen electrode side exhaust gas, and the fuel electrode side exhaust gas may be removed.
In addition, the retained heat of the reformed gas supplied from the transformer 39 to the carbon monoxide remover 40 and the retained heat of the fuel gas supplied from the fuel gas generation unit R to the cell stack 30 are also obtained. It is possible to use.

(H) In each of the above embodiments, the operation mode of the fuel cell G by the fuel cell control unit 36 is the power load following operation in which the actual power load is measured and the output power is changed and adjusted according to the measured power load. However, the operation mode of the fuel cell G is not limited to the power load follow-up operation. For example, the power load is predicted based on the actual power load measurement data, and the prediction is performed. The output power may be changed and adjusted according to the power load.

(I) In the second embodiment, the fuel cell control unit 36 is configured to control the operation of the fuel cell G so as to generate electric power larger than the electric power load so as to generate surplus electric power. Is not limited to the configuration in which the output power of the fuel cell G is adjusted to the set maximum output power. For example, the output power of the fuel cell G is set to a power that is larger than the power load. The structure to adjust may be sufficient.

(Nu) The installation form of the electric heater 28 that converts surplus power of the fuel cell G into heat for storing hot water in the hot water storage tank 5 is the form illustrated in the second embodiment, that is, the cooling water circulation path. It is not limited to the form which provides so that the cooling water which flows through 32 may be heated. For example, the hot water flowing through the upstream side of the temperature detection position of the tank supply temperature sensor Te in the hot water storage circuit 12 may be provided so as to be heated.

(L) In the second embodiment, the case where the maximum output operation is continued even after the hot water in the entire hot water storage tank 5 becomes equal to or higher than the set water quality maintenance temperature during the water quality maintenance operation is illustrated. When the hot water in the entire hot water storage tank 5 reaches the set water quality maintenance temperature, the maximum output operation may be stopped and switched to the power load following operation.

(W) In the first embodiment, as in the second embodiment, the electric heater 28 is provided, and the output power of the fuel cell G is set to the set maximum output power during the water quality maintenance operation. A maximum output operation for controlling the operation of the switch 29 so as to adjust and consume the surplus power of the fuel cell G by the electric heater 28 may be executed.

(W) In the first embodiment described above, the case where the heating flow path 15 is provided so as to return the hot water that has passed through the heating heat exchanger 11 to the hot water storage tank 5 is illustrated. The hot water having passed through the heat exchanger 11 may be provided so as to return to the upstream side of the exhaust heat source heat exchanger 14 in the hot water circulation circuit 12 by bypassing the hot water storage tank 5.

(F) In each of the above embodiments, the case where the heating unit H is configured to use heat generated from the combined heat and power supply as a heat source has been described, but a dedicated heat source such as a gas burner or an electric heater is provided. It is possible to configure such that heat generated from an engine-driven heat pump device in which a compressor is driven by a gas engine, a gasoline engine, or the like is used as a heat source. When heat generated from an engine-driven heat pump device is used as a heat source, heat generated from the heat pump itself or exhaust heat recovered by engine cooling water is used as a heat source.
In the case where the heat generated from the combined heat and power unit is used as a heat source, as a specific example of the combined heat and power unit, when the fuel cell G is applied as in the above embodiment, the model is the above embodiment. It is not limited to the solid polymer type illustrated in FIG. 1, and various types such as a phosphoric acid type and a solid electrolyte type can be used. In addition to the fuel cell G, a gas engine or gasoline can be used. It is possible to apply a rotary power generator configured to drive a generator by an engine or the like. In this case, exhaust heat recovered by engine cooling water is used as a heat source.

The block diagram which shows the flow of the hot water in the structure of the cogeneration system provided with the hot water storage type hot-water supply heat source apparatus concerning 1st Embodiment, and hot water storage independent operation mode The block diagram which shows the flow of the hot water in the water quality maintenance operation | movement of the cogeneration system provided with the hot water storage type hot-water supply heat source apparatus concerning 1st Embodiment. Block diagram showing the configuration of the fuel cell The block diagram which shows the flow of the hot water in the structure of the cogeneration system provided with the hot water storage type hot-water supply heat source apparatus concerning 2nd Embodiment, and water quality maintenance operation | movement.

Explanation of symbols

3 Hot-water supply path 4 Hot-water supply path 5 Hot-water storage tank 12 Hot-water supply circulation path 14 Heating action part 19 Auxiliary heater (auxiliary heating means)
19w Auxiliary heating unit for heating (auxiliary heating means for heating)
24 Tank bypass water supply path 25 Water supply switching three-way valve (Water supply state switching means)
28 Electric heater 50 Terminal bypass circuit 51 Heat medium circulation state switching three-way valve (heat medium circulation state switching means)
C Control means H Heating means G Cogeneration device

Claims (6)

A hot water storage tank which is supplied with water through a water supply channel and to which hot water is sent out through the water supply channel;
Heating means for heating the hot water in the hot water storage tank;
Auxiliary heating means for heating hot water flowing through the hot water supply path to a target hot water temperature;
A hot water storage type hot water supply heat source device provided with control means for controlling the operation of the heating means so that hot water is stored in the hot water storage tank at a target hot water storage temperature,
An auxiliary heating means for heating that heats the heat medium circulating in the heat medium circuit provided with the terminal for heat dissipation;
A heating heat exchanger for exchanging heat between hot water supplied from the heating means to the hot water storage tank and a heat medium circulating in the heat medium circulation path is provided;
As the water quality maintenance operation for maintaining the quality of the hot water in the hot water storage tank, the control means controls the heating means so as to continue the state in which the hot water in the entire hot water storage tank is equal to or higher than the preset water quality maintenance temperature. While performing the operation to be operated, in a state in which the heat medium is circulated through the heat medium circulation path at least until the hot water in the entire hot water storage tank becomes equal to or higher than the set water quality maintenance temperature during the water quality maintenance operation. A hot water storage type hot water supply heat source apparatus configured to execute an auxiliary temperature raising operation for operating the auxiliary heating means for heating. A heating medium circulating state switching means is provided that can freely switch the heating medium circulating in the heating medium circulation path to a terminal bypassing state that bypasses the heat radiating terminal through a terminal bypass.
The hot water storage hot water supply heat source apparatus according to claim 1, wherein the operation control means is configured to switch the heat medium circulation state switching means to the terminal device bypass state during execution of the auxiliary temperature raising operation. Water supplied from the hot water supply channel is supplied to the upstream side of the auxiliary heating means in the hot water supply channel, bypassing the hot water storage tank through the bypass water supply channel, and sent from the hot water storage tank to the hot water supply channel. A water supply state switching means is provided that can be switched to a tank bypass water supply state that stops the operation,
The control means determines whether or not it is the water quality maintenance operation timing that needs to perform the water quality maintenance operation, and when the water quality maintenance operation timing is reached, the water supply state switching means is set as the water quality maintenance operation. It is configured to switch to a tank detour water supply state, and to perform an operation for operating the heating means so as to continue a state in which the hot water in the entire hot water storage tank is equal to or higher than a set water quality maintenance temperature for a set water quality maintenance time. Item 3. A hot water storage heat source device according to item 1 or 2.   The control means is configured to determine a hot water replacement state in which hot water in the hot water storage tank is replaced in a form in which water is supplied to the hot water storage tank through the water supply passage and hot water in the hot water storage tank is sent out through the hot water supply passage. The hot water storage tank is configured such that the temperature of the hot water is lower than the set water quality maintenance temperature and the state in which the hot water replacement state is not discriminated continues for the set time for timing discrimination and the water quality maintenance operation timing is determined. The hot-water storage type hot water supply heat source device according to claim 3. The heating means is configured to heat the hot water in the hot water storage tank with heat generated from the combined heat and power supply device;
The control means generates electric power according to the electric power load during execution of normal operation, and generates electric power larger than the electric power load to generate surplus electric power during execution of the water quality maintenance operation. Configured to control the operation of the co-feeder;
An electric heater for converting the surplus power into heat for storing hot water in the hot water storage tank is provided at least until the hot water in the entire hot water storage tank reaches the set water quality maintenance temperature or higher during execution of the water quality maintenance operation. The hot water storage type hot water supply heat source device according to any one of claims 1 to 4. The hot water storage tank is configured in a sealed manner, the water supply path is connected to a tank bottom, and the hot water supply path is connected to an upper part of the tank;
The said heating means is comprised so that the hot water of the said hot water storage tank may be circulated through the circulation path for hot water storage in the form which returns the hot water taken out from the tank bottom part to a tank upper part via a heating action part. The hot water storage type hot water supply heat source device according to any one of the preceding claims.

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