JP2011252648A - Water heater of hot water storage type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater of hot water storage type capable of executing water quality improvement treatment under such condition as disadvantage in the point of operation efficiency is suppressed.SOLUTION: There are provided a hot water storage tank 2 to which water is supplied through a water supply path 16 connected to the bottom part while hot water is sent out through a hot water supply path 17 connected to an upper part, a hot water circulation unit 19 which circulates hot water of the hot water storage tank 2 through a circulation path 18 for hot water storage in such a mode where the hot water taken out of a tank bottom part is returned to a tank upper part, a heating unit H for heating the hot water that flows through the circulation path 18 for hot water storage, and a heating unit 24 for hot water supply that heats the hot water flowing through the hot water supply path 17. When discriminating a water quality improvement timing for coping with degradation in water quality of the hot water storage tank 2, an operation control unit 5 performs, as water quality improving treatment, a hot water heating process which actuates the heating unit 24 for hot water supply so as to heat the hot water flowing the hot water supply path 17 up to a heating reference temperature for improvement of water quality until an improvement in water quality of the hot water storage tank 2 is recognized.

Description

The present invention relates to a hot water storage tank in which water is supplied through a water supply path connected to the bottom and hot water is sent out through a hot water supply path connected to the upper part, and a hot water circulation in a form in which the hot water taken out from the tank bottom is returned to the upper part of the tank. Hot water circulating means for circulating hot water in the hot water storage tank through the passage, heating means for heating hot water flowing through the hot water storage circulation path, heating means for hot water supply heating hot water flowing through the hot water supply path, and operation Operation control means for controlling
The said operation control means is related with the hot water storage type hot water supply apparatus comprised so that a water quality improvement process may be performed, if the water quality improvement timing which copes with the water quality fall of the said hot water storage tank is discriminate | determined.

Such a hot water storage type hot water supply device is installed in, for example, a general household, and circulates hot water in a hot water tank through a hot water circulation path in such a manner that hot water taken out from the bottom of the tank is returned to the upper part of the tank by hot water circulation means. By heating the hot water flowing through the hot water storage circulation path by the heating means, the hot water is stored in a state where temperature stratification is formed in the hot water storage tank.
Then, hot water is sent out from the upper part of the hot water tank 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 low, the heating means for hot water supply is hot water. Will be heated. Moreover, with the delivery of the hot water, water is supplied to the bottom of the hot water tank through the water supply channel.
Incidentally, the heating means is constituted by a combined heat and power supply device such as a fuel cell that generates heat and electricity, for example.

Further, in such a hot water storage type hot water supply apparatus, when the operation control means determines the water quality improvement timing to cope with the water quality deterioration of the hot water storage tank, the water quality improvement process is executed.
That is, conventionally, hot water at the upper part of the hot water tank or a hot water temperature detecting means for detecting the temperature of hot water existing in the hot water supply path without being adjusted by being sent from the upper part of the hot water tank is provided and operated. When the control means is supplied to the hot water tank through the water supply channel and is not heated by the heating means but is present in the hot water tank, the temperature within the set low temperature range predicted as the temperature of the hot water is detected. When the non-low temperature duration time for continuing the state not detected by the temperature exceeds the allowable time for low temperature, it is determined that it is the water quality improvement timing, and the water quality improvement processing for suppressing the water quality deterioration of the hot water tank is executed (For example, refer to Patent Document 1).

As a configuration for determining the water quality improvement timing, there are various configurations in addition to the above configuration, as described in Patent Document 1.
For example, a plurality of hot water temperature detecting means for detecting the temperature of hot water in the hot water tank are provided at intervals from the bottom to the upper part of the hot water tank, and the operation control means is supplied to the hot water tank through the water supply channel. A state in which a temperature higher than a set low temperature range predicted as the temperature of hot water when it is present in the hot water tank without being heated by the heating means is detected by at least one of the hot water temperature detecting means is continued. There is a configuration in which it is determined that it is the water quality improvement timing when the non-low temperature duration is equal to or greater than the low temperature setting allowable time.

  In addition, a bath bottom hot water temperature detecting means for detecting the temperature of hot water present in the hot water circulation circuit without being adjusted by the temperature adjustment being sent from the hot water at the bottom of the hot water bath or the temperature of the hot water storage tank is provided, and operation control is provided. Non-high temperature continuation in which the temperature in the set high temperature range predicted as the temperature of hot water when the means is present in the hot water tank after being heated by the heating means is not detected by the bath bottom hot water temperature detecting means There is a configuration in which when the time is equal to or higher than the set allowable time for high temperature, it is determined that it is the water quality improvement processing timing.

  Furthermore, a plurality of hot water temperature detecting means for detecting the temperature of the hot water in the hot water tank are provided at a distance from the bottom to the top of the hot water tank, and the operation control means is heated by the heating means and then stored in hot water. Non-high temperature continuation time in which a state in which a temperature lower than the set high temperature range predicted as the temperature of hot water when it is present in the tank is detected by at least one of a plurality of hot water temperature detection means is allowed for high temperature setting There is a configuration in which it is determined that it is the water quality improvement processing timing when the time is over.

As a water quality improvement process, as described in Patent Document 1, there are various configurations.
For example, all of the plurality of hot water temperature detecting means provided at intervals from the bottom to the upper part of the hot water tank are set to the set low temperature range until the operation control means detects the set low temperature range by the tank upper hot water temperature detecting means. The hot water circulation means is controlled so as to control the operation of the hot water circulation means so that the amount of hot water circulation in the hot water circulation circuit is less than normal or until the hot water circulation circuit is stopped. There is a configuration for performing hot water replacement promotion processing to be controlled.
As another example, when the operation control means reaches the water quality improvement timing and the heating means is in operation and the hot water circulation means is in operation, the operation stop condition for stopping the operation of the heating means is When the operation stop condition is satisfied and the operation of the heating means and the operation of the hot water circulation means are stopped, the hot water temperature detecting means detects the set low temperature range or from the bottom of the hot water tank. There is a configuration in which a standby hot water replacement process for stopping the operation of the heating means and the operation of the hot water circulation means is executed until all of the plurality of hot water temperature detection means provided at intervals over the upper part detect the set low temperature range. .

Furthermore, as another example, there is provided hot water delivery stop means that can be switched to a hot water delivery stop state that stops delivery of hot water from the hot water tank through the hot water supply path, and the operation control means is set by the bath bottom hot water temperature detection means. Until the high temperature range is detected, or until all of the plurality of hot water temperature detection means provided at intervals from the bottom to the top of the hot water tank detect the set high temperature range, the hot water delivery stop means is put into the hot water delivery stop state. There is a configuration in which a hot water supply stop state heating process for operating the hot water circulating means and heating the heating means in the switched state is executed.
When this hot water delivery stop state heating process is executed, hot water from the water supply path is supplied to the hot water supply heating means by bypassing the hot water tank and supplied from the water supply path by the hot water heating means. Hot water is heated and supplied as hot water requested by the user.

Incidentally, the set high temperature range for determining the water quality improvement timing is set to 60 ° C., for example, and the set low temperature range for determining the water quality improvement timing is the temperature of hot water supplied to the hot water tank through the water supply channel. It was determined based on.
That is, a water supply temperature detection means for detecting the temperature of water supplied to the hot water tank through the water supply passage is provided, and the operation control means adds a set margin temperature (for example, 5 ° C.) to the detected temperature of the water supply temperature detection means. The temperature range below the set temperature is set to the set low temperature range.

That is, when the water supplied through the water supply channel is present in the hot water storage tank without being heated by the heating means, the heat transfer from the upper hot water or the hot water storage tank is stored in the hot water storage tank. If the temperature rises due to heat transfer from the peripheral wall, and the degree of temperature rise increases due to, for example, a longer time in the hot water storage tank, the water quality tends to deteriorate.
Therefore, even if hot water supplied in the hot water tank without being heated by the heating means is supplied through the water supply channel, even if the temperature rises, an elevated temperature capable of maintaining the water quality in a good state is tested. Thus, the obtained temperature is set as the set margin temperature, and the temperature range equal to or lower than the temperature obtained by adding the set margin temperature to the detected temperature of the feed water temperature detecting means is set as the set low temperature range.

JP 2009-133608 A

However, in the case where the hot water replacement promotion process or the standby hot water replacement process described above is executed as the water quality improvement process, until the tank upper hot water temperature detecting means detects the set low temperature range in a household where the amount of hot water used is small Or the time until all of the hot water temperature detecting means provided at intervals from the bottom to the top of the hot water tank detect the set low temperature range takes a long time. There is a disadvantage that the configured heating means is stopped for a long time.
In other words, when the heating means is a combined heat and power supply device, the time during which the combined heat and power supply device is stopped causes inconvenience that operation merits such as energy saving, economic efficiency, and environmental performance cannot be obtained. It was.

In addition, in the case where the hot water delivery stop state heating process described above is executed as the water quality improvement process, hot water is stored in the entire hot water storage tank by the water quality improvement process. When a part of the total amount of hot water stored is used, the water quality improvement timing is determined again, and the water quality improvement process is repeated again.
That is, even if hot water is stored in the entire hot water tank by the water quality improvement process, only a part of the total amount of the stored hot water is effectively used, and the water quality improvement process is executed. In some cases, extra energy must be used in order to heat and supply hot water from the water supply channel using the hot water supply heating means.

  In short, as a water quality improvement process, both hot water replacement promotion process and standby hot water replacement process and hot water delivery stop state heating process are performed in households where the amount of hot water used is low. There was a disadvantage in efficiency and improvement was desired.

  This invention is made | formed in view of this situation, The objective is to provide the hot water storage type hot-water supply apparatus which can perform a water quality improvement process in the state which suppressed the disadvantage of the operation efficiency.

The hot water storage type hot water supply apparatus of the present invention is a hot water storage tank in which water is supplied through a water supply path connected to the bottom part and hot water is sent through a hot water supply path connected to the upper part,
Hot water circulation means for circulating hot water in the hot water storage tank through the hot water circulation path in the form of returning the hot water taken out from the tank bottom to the upper part of the tank;
Heating means for heating hot water flowing through the hot water circulation circuit;
Heating means for hot water supply for heating hot water flowing through the hot water supply path;
Operation control means for controlling operation is provided,
The operation control means is configured to execute a water quality improvement process when determining a water quality improvement timing to cope with a water quality deterioration of the hot water tank, and the first characteristic configuration is
The operation control means performs, as the water quality improvement process, a hot water heating process for operating the hot water supply heating means to heat the hot water flowing through the hot water supply path to a heating reference temperature that improves water quality. It is characterized by being configured to execute until it is determined that the water quality has been improved.

That is, when the operation control means discriminates the water quality improvement timing to cope with the water quality deterioration of the hot water tank, the hot water flowing through the hot water supply path is heated to the heating reference temperature (for example, 60 ° C.) that improves the water quality as the water quality improvement processing. Thus, the hot water heating process for operating the hot water supply heating means is executed, and the hot water heating process is continued until it is determined that the water quality of the hot water tank is improved.
By the way, the water quality improvement state where the water quality of the hot water tank is improved is, for example, that the hot water tank is filled with hot water existing in the hot water tank without being heated by the heating means after being supplied to the hot water tank through the water supply channel. The tap water supplied through the water supply channel is kept in a good state by containing chlorine and the water quality is maintained in a good state when not heated by the heating means. When the hot water storage tank is filled with such hot water, the water quality of the hot water storage tank is improved.

As described above, the water quality improvement process is performed by heating the hot water flowing through the hot water supply path to a heating reference temperature (for example, 60 ° C.) for improving the water quality. There is no need to stop the heating means constituted by a co-feeder or the like.
Therefore, for example, when the heating means is a combined heat and power supply device, operating merits such as energy saving, economic efficiency, and environmental performance can be obtained by operating the combined heat and power supply device even when performing the water quality improvement process. It will be.

  In addition, since the water quality improvement treatment is performed by heating hot water flowing through the hot water supply path to a heating reference temperature (for example, 60 ° C.) that improves the water quality, it is used for the water quality improvement treatment. There is no need to store a large amount of hot water in a hot water tank.

  In short, according to the first characteristic configuration of the present invention, it is possible to provide a hot water storage type hot water supply apparatus that can execute water quality suppression processing in a state where disadvantages in terms of operation efficiency are suppressed.

In addition to the first feature configuration, the second feature configuration of the hot water storage type hot water supply apparatus of the present invention includes:
A bath upper hot water temperature detecting means for detecting the temperature of hot water present in the hot water supply path without being adjusted by being sent from the upper hot water of the hot water tank or the upper temperature of the hot water tank is provided,
The operation control means includes
Detecting the temperature of the hot water temperature in the upper portion of the tank as a temperature within a set low temperature range that is predicted as the temperature of the hot water when the hot water is supplied to the hot water tank through the water supply channel and is not heated by the heating means. When the non-low temperature continuation time for continuing the state not detected by the means is equal to or higher than the low temperature setting allowable time, it is determined that it is the water quality improvement timing, and
As the water quality improvement process, when the hot water heating process is being performed, if the temperature in the set low temperature range is detected by the tank upper hot water temperature detection means, it is determined that the water quality improvement state of the hot water tank is present. It is characterized by being configured as follows.

That is, the temperature of the hot water at the upper part of the hot water tank or the temperature of the hot water existing in the hot water supply path without being adjusted by the temperature adjustment is detected by the hot water temperature detecting means at the upper part of the hot water tank. A state in which the temperature in the set low temperature range, which is predicted as the temperature of the hot water when it is present in the hot water tank without being heated by the heating means after being supplied to the hot water tank through the water supply channel, is not detected by the hot water temperature detecting means at the upper part of the tank When the non-low-temperature duration time during which the temperature is maintained is equal to or greater than the set allowable time for low temperature, it is determined that the timing is for improving the water quality. The hot water heating process is performed to operate the hot water supply heating means so as to heat the hot water.
Then, when performing the hot water heating process as the water quality improving process, if the temperature in the set low temperature range is detected by the tank upper hot water temperature detecting means, it is determined that the hot water tank is in the water quality improving state, and the hot water heating process is performed. Will stop running.

In addition, when hot water in the hot water tank is circulated through the hot water storage circuit, the hot water taken out from the bottom of the hot water tank to the hot water storage circuit is heated by the heating means and then returned to the upper part of the hot water tank. Therefore, in a state where temperature stratification is formed, in other words, hot water heated by the heating means is stored in the upper part and hot water which is not heated by the heating means is stored in the lower part in the hot water storage tank. Hot water will be stored.
And since the water supply path is connected to the bottom of the hot water tank and the hot water supply path is connected to the upper part of the hot water tank, the amount of hot water not heated by the heating means stored in the lower part of the hot water tank is used for hot water storage. When the amount of hot water delivered from the upper part of the hot water storage tank through the hot water supply passage is larger than the amount of hot water circulated through the circulation passage, it increases, and when it is opposite, it decreases.
In other words, the state in which the amount of hot water sent from the upper part of the hot water tank through the hot water supply passage continues to be larger than the amount of hot water circulated through the hot water circulation circuit, or the hot water circulation in the hot water tank through the hot water circulation circuit If the state where hot water is sent from the upper part of the hot water storage tank through the hot water supply passage in a state where the hot water is stopped, hot water which is not heated by the heating means is stored in the entire hot water storage tank.

In this way, when hot water that has not been heated by the heating means is stored in the entire hot water tank, the temperature of the entire hot water tank or substantially the entire hot water is within the set low temperature range. The temperature of the hot water in the upper part of the tank or the temperature of the hot water that is sent out from the upper part of the hot water tank and is not adjusted in temperature is within the set low temperature range.
Therefore, when the temperature in the set low temperature range is detected by the tank upper hot water temperature detecting means, the whole or substantially the entire hot water tank is supplied to the hot water tank through the water supply channel and then filled with hot water not heated by the heating means. On the contrary, if the temperature in the set low temperature range is not detected by the tank upper hot water temperature detecting means, the entire hot water tank is supplied to the hot water tank through the water supply channel and then the heating means. Therefore, it can be determined that the state is not filled with unheated hot water.

  And even if the state where the entire temperature of the hot water storage tank is supplied to the hot water storage tank through the water supply channel and is not filled with hot water that is not heated by the heating means continues, the water quality is good. If the non-low temperature duration that keeps the temperature within the set low temperature range from being detected by the tank upper hot water temperature detection means exceeds the set allowable time for low temperature, the water quality improvement timing is set. It is determined that there is water quality improvement processing, and before the quality of the hot water in the hot water tank is lowered, the hot water heating treatment is appropriately performed as the water quality improvement processing, so that It is possible to suppress the hot water supply.

Also, if the temperature within the set low temperature range is detected by the bath upper hot water temperature detecting means, it is determined that the hot water storage tank is in a water quality improved state, and the hot water heating process is stopped. When the whole is supplied to the hot water tank through the water supply channel and filled with hot water that is not heated by the heating means, the hot water heating process as the water quality improvement process can be appropriately stopped. .
By the way, the tap water supplied through the water supply channel is kept in a good state by containing chlorine, etc., and is maintained in a good state when not heated by the heating means. When the hot water storage tank is filled with such hot water, the water quality of the hot water storage tank is improved.

  In short, according to the second characteristic configuration of the present invention, in addition to the operational effects of the first characteristic configuration, it is possible to provide a hot water storage type hot water supply apparatus capable of accurately performing water quality improvement processing.

The third feature configuration of the hot water storage type hot water supply apparatus of the present invention is in addition to the first feature configuration described above,
A plurality of hot water temperature detection means for detecting the temperature of the hot water in the hot water tank located at an interval from the bottom to the top of the hot water tank is provided,
The operation control means includes
The temperature of the plurality of hot water is higher than a preset low temperature range predicted as the temperature of hot water when the hot water is supplied to the hot water tank through the water supply channel and is not heated by the heating means. When the non-low temperature continuation time for continuing the state detected by at least one of the detection means is equal to or higher than the low temperature setting allowable time, it is determined that it is the water quality improvement processing timing, and
When the temperature within the set low temperature range is detected by all of the plurality of hot water temperature detecting means, it is determined that the water quality of the hot water tank is improved.

That is, the temperature of the hot water in the hot water tank is detected by a plurality of hot water temperature detecting means located at intervals from the bottom to the top of the hot water tank, and the operation control means is supplied to the hot water tank through the water supply passage and then the heating means The state where the temperature detected by the at least one of the plurality of hot water temperature detecting means is continuously detected is higher than the set low temperature range predicted as the temperature of the hot water when it is not heated in the hot water storage tank. When the low temperature duration exceeds the set allowable time for low temperature, it is determined that the water quality improvement timing is reached, and the hot water flowing through the hot water supply path is heated to a heating reference temperature (for example, 60 ° C.) that improves the water quality as a water quality improvement process. Thus, a hot water heating process for operating the hot water supply heating means is performed.
When the temperature within the set low temperature range is detected by all of the plurality of hot water temperature detecting means, it is determined that the water quality of the hot water tank is improved, and the hot water heating process is stopped.

In addition, as described in the description of the second characteristic configuration, when hot water that is not heated by the heating means is stored in the entire hot water tank, the entire hot water tank or substantially the entire hot water is stored. The temperature is within the set low temperature range.
Therefore, when all of the plurality of hot water temperature detecting means detect the temperature within the set low temperature range, the whole hot water tank is supplied to the hot water tank through the water supply channel and then heated with hot water that is not heated by the heating means. If the temperature in the set low temperature range is not detected by any one of a plurality of hot water temperature detecting means, the entire hot water tank or almost the entire hot water tank passes through the water supply channel to the hot water tank. After being supplied, it can be determined that the state is not filled with hot water not heated by the heating means.

  And even if the state where the entire temperature of the hot water storage tank is supplied to the hot water storage tank through the water supply channel and is not filled with hot water that is not heated by the heating means continues, the water quality is good. Set to a time that can be maintained in a stable state, and a non-low temperature duration time for continuing a state in which a temperature higher than a temperature within the set low temperature range is detected by at least one of a plurality of hot water temperature detecting means is set for low temperature When the time is longer than the allowable time, it is determined that it is time to improve the water quality, and by executing the water quality improvement process, the hot water heating process is appropriately performed as the water quality improvement process before the quality of the hot water in the hot water tank decreases. By doing so, it is possible to prevent hot water having a deteriorated water quality from being supplied.

  Moreover, if the temperature within the set low temperature range is detected by all of the plurality of hot water temperature detecting means, it is determined that the water quality of the hot water tank is improved, and the hot water heating process is stopped. Or, when almost the whole is supplied to the hot water storage tank through the water supply channel and is filled with hot water that is not heated by the heating means, the hot water heating process as a water quality improvement process is appropriately stopped. Can do.

  In short, according to the third characteristic configuration of the present invention, it is possible to provide a hot water storage type hot water supply apparatus capable of accurately performing the water quality improvement process in addition to the operational effects of the first characteristic configuration.

In addition to the second or third characteristic configuration described above, the fourth characteristic configuration of the hot water storage type hot water supply apparatus of the present invention includes:
The operation control means is configured to heat the hot water to the heating reference temperature when the temperature of the hot water supplied to the heating means for hot water supply or the temperature of the hot water at the upper part of the hot water storage tank is lower than the judgment reference temperature. And, as the water quality improvement process, either when the temperature of the hot water supplied to the heating means for hot water supply or the temperature of the hot water at the upper part of the hot water tank is less than the judgment reference temperature or when the temperature is higher than the judgment reference temperature Also, it is configured to execute the hot water heating process,
The set low temperature range is a range lower than the determination reference temperature.

  That is, when the temperature of the hot water supplied to the heating means for hot water supply or the temperature of the hot water in the upper part of the hot water storage tank is lower than the judgment reference temperature, the operation control means can improve the quality of the hot water (for example, 60 ° C.). When the temperature of the hot water supplied to the hot water supply heating means or the temperature of the hot water in the upper part of the hot water tank is lower than the judgment reference temperature, and the judgment reference temperature. In any of the above cases, the hot water heating process is performed.

  In other words, when the hot water supply is not determined to be the water quality improvement timing, the temperature of the hot water supplied to the heating means for hot water supply or the temperature of the hot water in the upper part of the hot water tank is lower than the judgment reference temperature, that is, When the temperature of the hot water supplied from the hot water storage tank is lower than the determination reference temperature, the hot water heating means is heated to a heating reference temperature (for example, 60 ° C.) that can improve the quality of the hot water. .

The determination reference temperature can be set to, for example, the lowest temperature (for example, 32 ° C.) of hot water required by the user.
In other words, hot water heated to the heating reference temperature or hot water from a hot water storage tank, if the temperature is higher than the temperature required by the user, mix the water from the water supply channel with the hot water and adjust the temperature. The temperature is adjusted by the mixing means to be performed and the hot water is discharged. That is, the mixing means adjusts the temperature of hot water heated to the heating reference temperature or hot water from the hot water storage tank to the hot water supply target temperature commanded by the hot water supply target temperature command means operated by the user. The determination reference temperature can be set to, for example, the lower limit (for example, 32 ° C.) of the temperature range that can be commanded by the hot water supply target temperature command means.
By the way, the mixing means will generally be provided in the hot water supply device, but if the hot water supply location such as the kitchen or bathroom is equipped with an automatic adjustment type mixing tap as the mixing means, it is provided in the hot water supply device. There is no need to let

In the case where hot water heated by the heating means for hot water supply is adjusted to a hot water supply target temperature (for example, 42 ° C.) set in advance as a fixed value by the mixing means, the determination reference temperature Can be determined as a hot water supply target temperature set in advance as a fixed value.
Incidentally, in the case of this form, generally, a hot water supply point is equipped with an automatic adjustment type or a manually operated type mixing plug.

  When the non-low temperature continuation time is equal to or higher than the set allowable time for low temperature, the operation control means determines that it is the water quality improvement timing, but the set low temperature range is lower than the determination reference temperature to be determined as described above. Therefore, the non-low temperature duration time is suppressed from exceeding the set allowable time for low temperature, and the frequency at which it is determined that the water quality improvement timing is reached decreases. The frequency of performing the heat treatment will decrease.

  That is, since the set low temperature range can be set, for example, to a range lower than the minimum temperature (for example, 32 ° C.) of the hot water temperature requested by the user, the detected temperature (usually normal) 20 ° C or less), and the upper limit value of the set low temperature range is higher than when the temperature range is equal to or less than the temperature obtained by adding the set margin temperature (for example, 5 ° C). It is suppressed that it becomes more than allowable time, and the frequency with which a water quality improvement process is performed will be reduced.

In this way, the set low temperature range is set to a range lower than the determination reference temperature to reduce the frequency at which the water quality improvement process is executed, but it is possible to avoid the supply of hot water having a deteriorated water quality.
In other words, while hot water is circulated by the hot water circulation means, hot water heated by the heating means is stored in the hot water storage tank, and hot water is stored in the hot water storage tank in a state where a temperature stratification is formed. And when the hot water in the hot water tank is used, the water from the water supply channel is supplied to the bottom of the hot water tank, so that the hot water in the hot water tank is heated from the bottom to the top. Will be stored.

  Therefore, if the temperature of the hot water detected by the tank upper hot water temperature detecting means (in the case of the second characteristic configuration) or all of the plurality of hot water temperature detecting means (in the case of the third characteristic configuration) is less than the determination reference temperature. After that, the temperature of hot water supplied from the hot water storage tank to the hot water supply path becomes lower than the judgment reference temperature, so that the tank upper hot water temperature detection means (in the case of the second feature configuration) or a plurality of hot water temperature detection means If the temperature of hot water detected in all cases (in the case of the third characteristic configuration) is lower than the determination reference temperature, the hot water supplied from the hot water tank to the hot water supply path after that is heated by the hot water heating means. Because it will be heated to the heating reference temperature that can improve the water quality of the water, by setting the set low temperature range to a range lower than the judgment reference temperature, it is possible to improve the water quality while avoiding the supply of hot water with reduced water quality Processing It is possible to reduce the frequency to be rows.

  In addition, since hot water circulated by the hot water circulating means and heated by the heating means is supplied to the upper part of the hot water storage tank, the hot water temperature detecting means (in the case of the second characteristic configuration) or a plurality of hot water temperatures is supplied. After the temperature of the hot water detected by all of the detection means (in the case of the third characteristic configuration) becomes lower than the determination reference temperature, high-temperature hot water heated by the heating means exists above the hot water tank. The hot water circulated by the hot water circulation means is heated to a state where the water quality is improved by the heating means, and the hot water is heated so that the water quality can be improved. There is no need.

  In short, according to the fourth characteristic configuration of the present invention, in addition to the operational effects of the second or third characteristic configuration, a hot water storage type hot water supply apparatus capable of reducing the frequency of executing the water quality improvement processing is provided. It came.

In addition to the fourth characteristic configuration described above, the fifth characteristic configuration of the hot water storage type hot water supply apparatus of the present invention includes:
A hot water supply target temperature command means for changing and setting the hot water supply target temperature is provided,
Mixing means for mixing hot water from the water supply path with hot water flowing through the hot water supply path to adjust to the hot water supply target temperature is provided,
The determination reference temperature is a lower limit value of a temperature range that can be commanded by the hot water supply target temperature command means.

That is, the hot water supplied from the hot water tank or the hot water heated to the heating reference temperature by the hot water heating means is adjusted to the hot water target temperature commanded by the hot water target temperature command means by the mixing means and hot water is supplied. It will be.
Then, the determination reference temperature is set to the lower limit value of the temperature range that can be commanded by the hot water supply target temperature command means, and the temperature of the hot water supplied to the hot water heating means or the temperature of the hot water in the upper part of the hot water tank is determined as the determination standard. When the temperature is lower than the temperature, the operation control means operates the hot water supply heating means to heat the hot water to a heating reference temperature that can improve the quality of the hot water.

  In this way, the determination reference temperature is set to the lower limit value of the temperature range that can be commanded by the hot water supply target temperature command means, so that the hot water supply heating means avoids performing the heating operation as much as possible while avoiding the hot water supply target temperature. Hot water of the hot water supply target temperature commanded by the command means can be supplied.

Incidentally, in the fifth characteristic configuration, the set low temperature range is such that the hot water supply heating means is also set when the hot water supply target temperature is set to the lower limit (determination reference temperature) of the temperature range that can be commanded by the hot water supply target temperature command means. However, the upper limit temperature of the hot water supplied to the heating means for hot water supply or hot water in the upper part of the hot water storage tank is heated to the heating reference temperature that can improve the quality of the hot water. When the temperature of the hot water supplied to the hot water supply heating means or the hot water in the hot water storage tank is within the set low temperature range, the hot water supply heating means can be used regardless of the target hot water supply temperature. However, the hot water is heated to a heating reference temperature that can improve the quality of the hot water.
And hot water is stored in the hot water storage tank in a state in which temperature stratification is formed, and hot water is stored in the hot water storage tank in a form of high temperature from the bottom to the top. When the temperature of the hot water supplied to the heating means or the hot water in the hot water storage tank is within the set low temperature range, the temperature of the hot water supplied to the heating means for hot water supply or the hot water in the hot water tank is within the set low temperature range thereafter. Therefore, the hot water supply heating means accurately heats the hot water to the heating reference temperature at which the quality of the hot water can be improved, and it is a matter of course that the hot water supply without improving the water quality is suppressed.

  It should be noted that the operation control means is configured such that the temperature of the hot water supplied to the hot water supply heating means or the temperature of the hot water supplied to the hot water supply heating means even when the temperature of the hot water supplied to the hot water supply heating means or the temperature of the hot water in the upper part of the hot water tank is equal to or higher than the determination reference temperature Alternatively, when the temperature of the hot water in the upper part of the hot water tank is lower than the target hot water temperature, the hot water heating means is operated to heat the hot water, and the temperature for heating the hot water is a heating standard that can improve the water quality. Although the temperature can be set, the hot water supply target temperature or a temperature higher than the hot water supply target temperature by a set value can also be set.

  In short, according to the fifth characteristic configuration of the present invention, in addition to the operational effects of the fourth characteristic configuration, the hot water supply heating means is instructed by the hot water supply target temperature command means while avoiding the heating operation as much as possible. It is possible to provide a hot water storage type hot water supply apparatus that can supply hot water at a target hot water supply temperature.

In addition to the fourth characteristic configuration, the sixth characteristic configuration of the hot water storage type hot water supply apparatus of the present invention is:
A hot water supply target temperature command means for changing and setting the hot water supply target temperature is provided,
Mixing means for mixing the hot water from the water supply path with hot water flowing through the hot water supply path after being heated by the heating means for hot water supply and adjusting to the hot water supply target temperature is provided,
The determination reference temperature is a temperature obtained by adding a set increase temperature to a lower limit value of a temperature range that can be commanded by the hot water supply target temperature command means.

That is, the hot water supplied from the hot water tank or the hot water heated to the heating reference temperature by the hot water heating means is adjusted to the hot water target temperature commanded by the hot water target temperature command means by the mixing means and hot water is supplied. It will be.
The determination reference temperature is set to a temperature obtained by adding a set increase temperature to the lower limit value of the temperature range that can be commanded by the hot water supply target temperature command means, and the temperature of the hot water supplied to the hot water heating means or the hot water storage tank When the temperature of the upper hot water is lower than the judgment reference temperature, the operation control means operates the hot water supply heating means to heat the hot water to a heating reference temperature that can improve the quality of the hot water.

  In this way, the determination reference temperature is set to a temperature obtained by adding the set temperature to the lower limit value of the temperature range that can be commanded by the hot water supply target temperature command means, so that the hot water heating means performs the heating operation as much as possible. While avoiding, the hot water at the hot water supply target temperature commanded by the hot water supply target temperature command means can be accurately supplied.

  That is, if the determination reference temperature is set to the lower limit value of the temperature range that can be commanded by the hot water supply target temperature command means, the temperature of the supplied hot water or the temperature of the hot water in the hot water tank is in a minute range but fluctuates. In addition, a state in which the heating operation of the heating means for hot water supply is executed and a state in which the heating operation is stopped may be repeated. However, by setting the reference temperature to the lower limit of the temperature range that can be commanded by the hot water supply target temperature command means, the temperature is extremely low. It is possible to prevent hot water from being supplied.

Incidentally, in the sixth feature configuration, when the set low temperature range is set to a temperature (determination reference temperature) obtained by adding the set temperature to the lower limit value of the temperature range that can be commanded by the hot water supply target temperature command means. Moreover, the upper limit temperature of the temperature range of the hot water supplied to the heating means for hot water supply or hot water to the hot water storage tank, where the heating means for hot water supply heats the hot water to the heating reference temperature that can improve the quality of the hot water, Since this corresponds to the range of the upper limit temperature, when the temperature of the hot water supplied to the hot water supply heating means or the hot water in the hot water storage tank is within the set low temperature range, the hot water supply target temperature is changed to any temperature. However, the hot water supply heating means heats the hot water to a heating reference temperature that can improve the quality of the hot water.
And hot water is stored in the hot water storage tank in a state in which temperature stratification is formed, and hot water is stored in the hot water storage tank in a form of high temperature from the bottom to the top. When the temperature of the hot water supplied to the heating means or the hot water in the hot water storage tank is within the set low temperature range, the temperature of the hot water supplied to the heating means for hot water supply or the hot water in the hot water tank is within the set low temperature range thereafter. Therefore, the hot water supply heating means accurately heats the hot water to the heating reference temperature at which the quality of the hot water can be improved, and it is a matter of course that the hot water supply without improving the water quality is suppressed.

  Note that the operation control means is configured such that the temperature of the hot water supplied to the hot water supply heating means or the hot water storage tank even if the temperature of the hot water supplied to the hot water supply heating means or the temperature of the hot water in the upper part of the hot water storage tank is equal to or higher than the reference temperature. When the temperature of the hot water at the top of the water is lower than the target hot water supply temperature, the hot water is heated, and the temperature at which the hot water is heated can be set to a heating reference temperature that can improve the water quality, It can also be set to a temperature that is higher than the temperature or hot water supply target temperature by a set value.

  In short, according to the sixth feature configuration of the present invention, in addition to the operational effect of the fourth feature configuration, the hot water supply heating means is instructed by the hot water supply target temperature command means while avoiding the heating operation as much as possible. The present invention has provided a hot water storage type hot water supply device capable of accurately supplying hot water at a target hot water supply temperature.

In addition to any of the first to third characteristic configurations described above, the seventh characteristic configuration of the hot water storage type hot water supply apparatus of the present invention is:
A hot water supply target temperature command means for changing and setting the hot water supply target temperature is provided,
Mixing means for mixing hot water from the water supply path with hot water flowing through the hot water supply path to adjust to the hot water supply target temperature is provided,
When the temperature of hot water supplied to the heating means for hot water supply or the temperature of hot water in the upper part of the hot water storage tank is lower than the target hot water supply temperature, the operation control means flows the hot water supply passage to the hot water supply target temperature. A hot water supply heating process for operating the hot water supply heating means to heat the hot water is performed, and as the water quality improvement process, either hot water flowing through the hot water supply path is lower or higher than the hot water supply target temperature. Is also configured to perform the hot water heating process.

  That is, when the temperature of the hot water supplied to the hot water supply heating means or the temperature of the hot water in the upper part of the hot water storage tank is lower than the target hot water supply temperature, the operation control means heats the hot water flowing through the hot water supply path to the hot water supply target temperature. The hot water supply heating process for operating the heating means for hot water supply is performed as described above, and as the water quality improvement process, the water quality is high both when the hot water flowing through the hot water supply path is lower and higher than the target hot water supply temperature. A hot water heating process for operating hot water heating means to heat the hot water flowing through the hot water supply path to a heating reference temperature (for example, 60 ° C.), and the hot water heating process, It will continue until the water quality improvement of the hot water tank is determined.

  Moreover, when the temperature of the hot water from the hot water storage tank becomes higher than the target hot water supply temperature, and as a water quality improvement process, the hot water flowing through the hot water supply passage is heated to a heating reference temperature (for example, 60 ° C.) that improves the water quality. When the hot water heating process for operating the hot water supply heating means is executed and the temperature of the hot water becomes higher than the hot water supply target temperature, the mixing means adjusts the temperature of the hot water to be supplied to the hot water supply target temperature. Become.

  In short, according to the seventh characteristic configuration of the present invention, in addition to the operational effects of any of the first to third characteristic configurations, the water quality improvement process can be performed while appropriately supplying hot water at the hot water supply target temperature. A hot water storage device can be provided.

Schematic diagram showing the overall configuration of the cogeneration system The figure which shows the flowchart which shows the control action of the whole system The figure which shows the flowchart of duration measurement processing The figure which shows the flowchart of the duration measurement process of another embodiment.

[First Embodiment]
Hereinafter, a first embodiment when a hot water storage type hot water supply apparatus of the present invention is applied to a cogeneration system will be described with reference to the drawings.
As shown in FIG. 1, the cogeneration system recovers the heat generated by the fuel cell 1 as a combined heat and power generation apparatus that generates electric power and heat, and the heat generated by the fuel cell 1 with cooling water. A hot water storage / heating unit 4 that stores hot water in the hot water tank 2 and supplies a heat medium to the heat consuming terminal 3, an operation control unit 5 as operation control means for controlling the operation of the fuel cell 1 and the hot water storage / heating unit 4, etc. It is composed of
Incidentally, the heat consuming terminal 3 is provided with a floor heating device, a bathroom heating dryer, a fan convector, or the like.

The fuel cell 1 is configured so that the power generation output can be adjusted by adjusting the supply amount of the fuel gas (hydrogen gas), and is the same as the received power that receives the generated power of the fuel cell 1 from the commercial power supply 7. An inverter 6 for grid connection having the same voltage and the same frequency is provided.
That is, the commercial power supply 7 is electrically connected to the power load 9 such as a television, a refrigerator, a washing machine, etc. via the received power supply line 8, and the inverter 6 supplies the received power via the generated power supply line 10. The electric power is electrically connected to the line 8, and the electric power generated by the fuel cell 1 is supplied to the electric power load 9 via the inverter 6 and the generated electric power supply line 10.

The received power supply line 8 is provided with power load measuring means 11 for measuring the load power of the power load 9, and this power load measuring means 11 determines whether or not a reverse power flow occurs in the current flowing through the received power supply line 8. It is also configured to detect.
The electric power supplied from the fuel cell 1 to the received power supply line 8 is controlled by the inverter 6 so that a reverse power flow does not occur, and the surplus power of the power generation output is recovered by replacing the surplus power with heat. 12 is configured to be supplied.

A cooling water circulation path 13 for circulating the cooling water of the fuel cell 1 by the operation of the cooling water circulation pump 15 is provided, and an electric heater 12 is provided to heat the cooling water of the fuel cell 1 flowing through the cooling water circulation path 13. ,
The electric heater 12 is composed of a plurality of electric heaters, and is configured to be switched ON / OFF separately by an operation switch 14 connected to the output side of the inverter 6. In order to increase the power consumption of the electric heater 12 as the size increases, the electric heater 12 is operated according to the amount of surplus power.
The configuration for adjusting the power consumption of the electric heater 12 is a configuration for adjusting the output of the electric heater 12 by, for example, phase control or the like in addition to the configuration for switching ON / OFF of the plurality of electric heaters 12 as described above. It may be adopted.

The above-described hot water storage tank 2 provided in the hot water storage / heating unit 4 is configured so that water is supplied through a water supply path 16 connected to the bottom, and hot water is sent out through a hot water supply path 17 connected to the top.
In addition to the hot water storage tank 2, the hot water storage heating unit 4 is connected to the hot water storage tank 2 at the bottom and the top thereof, and is connected to the hot water storage circuit 18 (indicated by a thick line in FIG. 1). Hot water extracted from the hot water circulation pump 19 circulates and supplies the heat medium to the heat consuming terminal 3 through the hot water circulation pump 19 and the heat medium circulation path 20 as hot water circulation means for circulating the hot water in the hot water tank 2 in the form of returning to the upper part of the tank. A hot water storage heat exchanger 22 that heats hot water flowing through the pump 21, the hot water circulation path 18, and a heat medium heating heat exchanger 23 that heats the heat medium flowing through the heat medium circulation path 20; Furthermore, the hot water supply auxiliary heater 24 serving as a hot water supply heating means for heating hot water sent from the hot water storage tank 2 and flowing through the hot water supply passage 17, and the heating medium flowing through the heating medium circulation passage 20 are heated. A heating medium auxiliary heater 25 is provided.

  In the hot water storage heat exchanger 22, the cooling water of the fuel cell 1 is circulated through the above-described cooling water circulation path 13. Therefore, the hot water storage heat exchanger 22 exchanges heat between the cooling water of the fuel cell 1 flowing through the cooling water circulation path 13 and the hot water flowing through the hot water circulation path 18, and flows through the hot water circulation path 18. The hot and cold water to be heated is heated by the exhaust heat of the fuel cell 1.

  A radiator 33 that cools the cooling water that returns to the fuel cell 1 is provided in a return flow path portion that returns the cooling water from the hot water storage heat exchanger 22 toward the fuel cell 1 in the cooling water circulation path 13. A cooling water return temperature sensor Sr for detecting the temperature of the cooling water returning to the fuel cell 1 is provided at a location between the radiator 33 and the fuel cell 1 in the road portion.

After branching from the circulation path portion connecting the hot water storage heat exchanger 22 and the upper part of the hot water tank 2 in the hot water circulation circuit 18, it is connected to the circulation path portion connecting the bottom of the hot water tank 2 and the hot water circulation pump 19. The heating medium heating flow path portion 18b is provided in a form that bypasses the hot water tank 2.
A heat exchanger 23 for heat medium heating is provided so as to exchange heat between the hot water flowing through the heat medium heating flow path portion 18 b and the heat medium flowing through the heat medium circulation path 20. The heating medium heating state in which hot and cold water is passed through the heating medium heating flow path portion 18b and the hot water in the branch portion of the heating medium heating flow path portion 18b in the circulation path 18 and hot water are passed through the heating medium heating flow path portion 18b. A heating switching three-way valve 26 is provided for switching to a non-heated heating medium non-heating state.

  Therefore, with the heating switching three-way valve 26 switched to the heating medium non-heated state, the cooling water recovered from the heat generated by the fuel cell 1 passes through the cooling water circulation path 13 and the hot water storage heat exchanger 22 by the cooling water circulation pump 15. The hot water in the hot water storage tank 2 can be stored in the hot water storage tank 2 by circulating the hot water in the hot water storage tank 2 through the hot water circulation circuit 18 and passing through the hot water storage heat exchanger 22. Moreover, since the hot water taken out from the bottom of the hot water tank 2 is heated by the hot water storage heat exchanger 22 and then supplied to the upper part of the hot water tank 2, the hot water is stored in the hot water tank 2 in a state where temperature stratification is formed. Will be.

  Further, with the heating switching three-way valve 26 switched to the heating medium heating state, the cooling water recovered from the heat generated by the fuel cell 1 is passed through the cooling water circulation path 13 by the cooling water circulation pump 15 through the hot water storage heat exchanger 22. The hot water heated by the hot water storage heat exchanger 22 is circulated through the heat medium heating flow path portion 18b, and the heat medium heating heat exchanger 23 passes the heat medium circulation path 20 through the heat medium heating flow path portion 18b. The flowing heat medium can be heated.

  Incidentally, in the present embodiment, the heating unit H as a heating means for heating the hot water flowing through the hot water storage circuit 18 includes the fuel cell 1, the cooling water circuit 13, the cooling water circulation pump 15, the hot water circuit 18, The hot water circulation pump 19 and the hot water storage heat exchanger 22 are configured as main parts.

  The heat medium circulation path 20 is provided with a terminal bypass circuit 29 that bypasses the heat consuming terminal 3 and allows the heat medium to flow, and further, a connection portion between the heat medium circulation path 20 and the terminal bypass circuit 29 has a heat There is provided a heat medium circulation switching three-way valve 30 that can be switched between a normal flow state in which the medium is circulated through the heat consuming terminal 3 and a terminal detour flow state in which the medium is circulated through the terminal detour 29 to bypass the heat consuming terminal 3. It has been.

The hot water supply auxiliary heater 24 and the heat medium auxiliary heater 25 have the same configuration, and both of them include a heat exchanger h for heating hot water or a heat medium, a burner b for heating the heat exchanger h, and a burner for the heat exchanger h. a fan f for supplying combustion air to 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 the outflow temperature of hot water or heat medium flowing out of the heat exchanger h And an outflow temperature sensor (not shown) for detecting the flow rate, a flow rate sensor (not shown) for detecting the flow rate of hot water or heat medium flowing into the heat exchanger h, and the like.
The operation of the auxiliary heater for hot water supply 24 and the auxiliary heater for heat medium 25, that is, the heating operation is configured to be controlled by the operation control unit 5.

  The operation control of the hot water supply auxiliary heater 24 by the operation control unit 5 will be described. In the operation control unit 5, the flow rate sensor that detects the flow rate of hot water flowing into the heat exchanger h detects a flow rate that is equal to or higher than the set flow rate. In this state, when the inflow temperature detected by the inflow temperature sensor (the temperature of hot water supplied to the hot water supply auxiliary heater 24) is lower than the determination reference temperature (for example, 37 ° C.), the burner b is used to heat the hot water. And based on the feed-forward control based on the flow rate detected by the flow rate sensor and the inflow temperature detected by the inflow temperature sensor, and the outflow temperature detected by the outflow temperature sensor By the feedback control, the combustion amount of the burner b is adjusted in order to heat the hot water to the heating reference temperature (for example, 60 ° C.), and the flow rate sensor during the burner b combustion. When the detected flow is less than the set flow rate, thereby to extinguish the burner b.

  The operation control unit 5 also detects the inflow temperature (for hot water supply) detected by the inflow temperature sensor in a state where the flow rate sensor that detects the flow rate of hot water flowing into the heat exchanger h detects a flow rate that is equal to or higher than the set flow rate. Even if the temperature of the hot water supplied to the auxiliary heater 24 is equal to or higher than the determination reference temperature (for example, 37 ° C.), the hot water is heated when the inflow temperature detected by the inflow temperature sensor is lower than the hot water supply target temperature. Therefore, the burner b is burned, and detected by the feedforward control based on the flow rate detected by the flow rate sensor and the inflow temperature detected by the inflow temperature sensor, and the outflow temperature sensor. According to feedback control based on the outflow temperature, the amount of combustion of the burner b is adjusted to heat the hot and cold water to the heating reference temperature (for example, 60 ° C.). When detecting the flow rate sensor is less than the set flow rate, thereby to extinguish the burner b.

That is, when the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is lower than the determination reference temperature (for example, 37 ° C.), the operation control unit 5 heats the hot water to the heating reference temperature (for example, 60 ° C.). In addition, the hot water supply auxiliary heater 24 is heated and operated. In addition, even if the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is equal to or higher than the reference temperature, the hot water supply auxiliary heater 24 is supplied. When the temperature of the hot water to be performed is lower than the target hot water supply temperature, the hot water supply auxiliary heater 24 is heated so as to heat the hot water to the heating reference temperature (for example, 60 ° C.).
In the following description, this control operation is referred to as hot water supply heating processing.

And the mixing means which mixes the hot water from 16 A of water supply paths branched from the water supply path 16 mentioned above with respect to the hot water from the hot water supply path 17 in the downstream part of the hot water supply auxiliary heater 24 in the hot water supply path 17. A mixing valve 34 is provided.
This mixing valve 34 is supplied from the hot water supply passage 17 so that the temperature of the hot water discharged from the hot water supply passage 17 becomes the target hot water supply temperature set by the operation remote controller R that commands various information to the operation control unit 5. Hot water from the water supply channel portion 16A is mixed with hot water, and the operation control unit 5 performs mixing based on detection information such as a mixed hot water temperature sensor (not shown) that detects the mixed hot water temperature. The hot water mixing operation of the valve 34 is controlled.

Incidentally, in this embodiment, the operation remote controller R functions as a hot water supply target temperature command means for changing and setting the hot water supply target temperature, and the operation remote controller R has a temperature range between 32 ° C. and 60 ° C., for example. The hot water supply target temperature is commanded.
Then, the determination reference temperature is set to a temperature obtained by adding a set increase temperature (for example, 5 ° C.) to the lower limit value of the temperature range that can be commanded by the operation remote controller R.
Incidentally, the determination reference temperature can be set to the lower limit value of the temperature range that can be commanded by the operation remote controller R.

Briefly describing the operation control of the heating medium auxiliary heater 25 by the operation control unit 5, the operation control unit 5 is detected by the inflow temperature sensor in a state where the flow sensor detects a flow rate equal to or higher than the set flow rate. When the inflow temperature is lower than the target temperature, the burner b is burned to heat the heating medium, and based on the inflow temperature detected by the inflow temperature sensor and the flow rate detected by the inflow temperature sensor. , Feed-forward control, and feedback control based on the outflow temperature detected by the outflow temperature sensor, the amount of combustion of the burner b is adjusted to heat the heating medium to the target temperature, and the burner b If the detected flow rate of the flow rate sensor becomes less than the set flow rate during combustion, the burner b is extinguished.
The target temperature in the auxiliary heater for heat medium 25 is set to a high temperature target temperature (for example, 80 ° C.) when the heat consuming terminal 3 requires a high temperature, and the heat consuming terminal 3 does not require a high temperature. In this case, it is set to a low temperature target temperature (for example, 60 ° C.).

  The water supply path 16 is provided with a water supply temperature sensor Si for detecting the temperature of the water supplied to the hot water tank 2 through the water supply path 16, and a hot water storage heat exchanger 22 and a heating switching three-way valve in the hot water storage circulation path 18. A hot water storage temperature sensor Sh that detects the temperature of the hot water heated by the hot water storage heat exchanger 22 is provided at a location between the hot water storage unit 26 and the hot water storage unit 26.

  The hot water storage tank 2 includes a tank upper hot water temperature sensor St as a tank upper hot water temperature detecting means for detecting the temperature of the hot water in the upper part thereof, and an upper end of the middle layer portion of the hot water storage tank 2 divided into three equal parts in the vertical direction. An intermediate upper hot water temperature sensor Sm for detecting the temperature of the hot water of the portion, an intermediate lower hot water temperature sensor Sn for detecting the temperature of the hot water at the lower end portion of the middle layer of the hot water tank 2, and the temperature of the hot water at the bottom of the hot water tank 2 A tank bottom hot water temperature sensor Sb is provided as a tank bottom hot water temperature detection means for detection.

Further, a hot water supply heat load measuring means 31 for measuring a hot water supply heat load when hot water is supplied to the hot water supply destination is provided at a location downstream of the mixing valve 34 in the hot water supply passage 17. Terminal thermal load measuring means 32 for measuring the terminal thermal load is also provided.
The hot water supply thermal load measuring means 31 and the terminal thermal load measuring means 32 are a load detection temperature sensor (not shown) for detecting the temperature of flowing hot water and heat medium, and a load for detecting the flow rate of hot water and heat medium. The operation control unit 5 includes a detection flow sensor (not shown) and a feed water temperature sensor Si, and the operation control unit 5 detects the detection temperature of the load detection temperature sensor, the detection flow rate of the load detection flow sensor, and the detection temperature of the feed water temperature sensor Si. Is configured to detect a hot water supply heat load and a terminal heat load.

  As will be described later, the operation control unit 5 obtains an operation time zone for operating the fuel cell 1 and operates the fuel cell, and operates the cooling water circulation pump 15 during the operation of the fuel cell 1. In this state, the operation of the fuel cell 1 is controlled, and the hot water circulating pump 19, the heat medium circulating pump 21, and the heating switching three-way valve 26 are controlled to store hot water in the hot water tank 2. The operation and the heat medium supply operation for supplying the heat medium to the heat consuming terminal 3 are performed.

  In other words, the operation control unit 5 performs a hot water storage operation when no operation command is issued from a terminal remote controller (not shown) for the heat consuming terminal 3, and in the hot water storage operation, the heating switching three-way valve 26 is turned off. In the state of switching to the heating state, the operation of the hot water circulation pump 19 is controlled so as to adjust the hot water circulation amount so that the detected temperature of the hot water temperature sensor Sh becomes a preset target hot water storage temperature (for example, 60 ° C.). It is configured as follows.

In addition, when the operation is commanded from the terminal remote controller, the operation control unit 5 performs a heat medium supply operation. In the heat medium supply operation, the heating switching three-way valve 26 is switched to the heat medium heating state. The operation of the hot water circulation pump 19 is controlled so that the heat medium circulation pump 21 is operated at a preset rotational speed and the hot water circulation amount is adjusted so that the detected temperature of the hot water temperature sensor Sh becomes the target hot water temperature. Is configured to do. The operation control unit 5 is configured to switch the heat medium circulation switching three-way valve 30 to a normal flow state while executing the heat medium supply operation.
Further, when the operation control unit 5 is instructed to stop the operation from the terminal remote controller during the execution of the heat medium supply operation, the operation control unit 5 switches the heating switching three-way valve 26 to the heat medium non-heated state, It is configured to stop and switch from the heat medium supply operation to the hot water storage operation.

The operation control unit 5 monitors the detected temperature of the cooling water return temperature sensor Sr during the operation of the fuel cell 1, and when the detected temperature becomes higher than the set return allowable temperature, the operation control unit 5 operates the radiator 33 to perform cooling. It is configured to cool the water.
That is, for example, when the amount of hot water stored in the hot water tank 2 is full and the hot water storage heat exchanger 22 cannot cool the cooling water to the set return allowable temperature by heat exchange with the hot water from the hot water tank 2. The radiator 33 is actuated so that the cooling water returning to the fuel cell 1 can be cooled to the set return allowable temperature.

Next, control of the operation of the fuel cell 1 by the operation control unit 5 will be described.
The operation control unit 5 stores time-series power load past data and time-series heat load (hot water supply heat load and terminal heat load), and based on the stored data, at the start of the operation cycle, A time-series predicted power load and a time-series predicted heat load are obtained, and an operation time zone in which the fuel cell 1 is operated is determined based on the obtained time-series predicted power load and time-series predicted heat load. The operation merit for each of a plurality of operation modes with different and different power output forms of the fuel cell 1 with respect to the predicted power load is obtained, and the operation mode with the highest obtained operation merit is determined as the operation of the fuel cell 1. The fuel cell 1 is configured to operate in the determined operation mode.
For example, the operation cycle is set to 1 day, a plurality of operation unit times constituting the operation cycle is set to 1 hour, and the start point of the operation cycle is set to 3 o'clock. And as the said operation merit, it is comprised so that the prediction energy reduction amount estimated to be obtained by operating the fuel cell 1 is calculated | required.

As a plurality of types of operation modes, a continuous operation mode in which the fuel cell 1 is continuously operated during the operation cycle, and the fuel cell 1 is operated in the operation time zone during the operation cycle, and the operation is performed in other time zones. There are intermittent operation modes to stop.
As a continuous operation mode, in a load following continuous operation mode in which the power generation output of the fuel cell 1 follows the predicted power load in the entire time period of the operation cycle, in some unit times of the plurality of unit times of the operation cycle A suppression continuous operation mode in which the power generation output of the fuel cell 1 is set to a setting suppression output smaller than the predicted power load and the power generation output of the fuel cell 1 follows the predicted power load in the remaining unit time, and a plurality of unit times of the operation cycle A forced continuous operation mode in which the power generation output of the fuel cell 1 is set to be a set increase output larger than the predicted power load in a part of the unit time and the power generation output of the fuel cell 1 follows the predicted power load in the remaining unit time. is there.

  In addition, as an intermittent operation mode, a unit time in which the predicted energy reduction amount is the largest among a plurality of unit times of the operation cycle, where a unit time for causing the power generation output of the fuel cell 1 to follow the predicted power load is an operation time zone. The load following intermittent operation mode defined in the above, the unit time for adjusting the power generation output of the fuel cell 1 to a setting suppression output smaller than the predicted power load is the operation time zone, and the predicted energy reduction is the most among a plurality of unit times of the operation cycle A plurality of unit times of the operation cycle, with the suppression intermittent operation mode determined as the unit time in which the amount increases and the unit time for adjusting the power generation output of the fuel cell 1 to a set increase output larger than the predicted power load as the operation time zone Among them, there is a forced intermittent operation mode that is determined in a unit time in which the predicted energy reduction amount is the largest.

  Further, in the intermittent operation mode, the single cycle correspondence type for obtaining the operation merit for each of the load following intermittent operation mode, the suppression intermittent operation mode and the forced intermittent operation mode for the operation cycle for one day, and the operation cycle for two days The two-day response type that is required for the three-day operation type and the three-day response type that is required for the three-day driving cycle are included.

  In short, the operation control unit 5 varies the operation time zone in which the fuel cell 1 is operated and the predicted power load based on the time-series predicted power load and the time-series predicted heat load at the start of the operation cycle. The operation merit for a plurality of types of operation modes with different power output modes of the fuel cell 1 is obtained, and the operation mode with the highest obtained operation merit is determined as the operation mode of the fuel cell 1, and the determination is made. The fuel cell 1 is operated in the same operation mode, but in the present embodiment, detailed description thereof is omitted.

  The operation control unit 5 is configured to determine the water quality improvement timing for suppressing the water quality deterioration of the hot water tank 2 and execute the water quality improvement processing when the water quality improvement timing is determined, and as the water quality improvement processing, The water quality of the hot water storage tank 2 is improved by the hot water heating process that operates the hot water supply auxiliary heater 24 so as to heat the hot water flowing through the hot water supply passage 17 to a heating reference temperature (for example, 60 ° C.) that improves the water quality. It is configured to execute until it is determined that the water quality is improved.

  That is, the operation control unit 5 uses the first duration as the non-low temperature duration for continuing the state where the temperature in the set low temperature range, which will be determined as described later, is not detected by the tank upper hot water temperature sensor St, for the low temperature. When it becomes more than the first set allowable time as the allowable time, it is determined that it is the water quality improvement timing, and as the water quality improvement processing, the hot water flowing through the hot water supply path 17 to the heating reference temperature (for example, 60 ° C.) that improves the water quality. When the temperature in the set low temperature range is detected by the tank upper hot water temperature sensor St, the hot water storage tank 2 is in a water quality improved state. It is determined that there is, and the hot water heating process is stopped.

In other words, the operation control unit 5 starts measuring the first duration when the detected temperature of the tank upper hot water temperature sensor St becomes higher than the set low temperature range, and the detected temperature of the tank upper hot water temperature sensor St becomes the set low temperature. In a state where the first duration time is reset to 0 when the temperature falls within the range, the first duration time is measured, and when the first duration time exceeds the first set allowable time, it is determined that it is the water quality improvement timing, Water quality improvement processing will be executed.
And the operation control part 5 will perform the above-mentioned hot-water heating process as a water quality improvement process until the temperature in a setting low temperature range is detected by the tank upper hot-water temperature sensor St.

  Incidentally, in the present embodiment, as described later, the second continuation time as a non-high temperature continuation time during which the tank bottom hot water temperature sensor Sb does not detect the temperature within the set high temperature range determined as described below is high. When the time is equal to or longer than the second set allowable time as the allowable time for use, the water quality improvement processing is executed as the water quality improvement timing. For this reason, the detection temperature of the tank upper hot water temperature sensor St is set. In addition to resetting the first duration to 0 when the temperature falls within the low temperature range, the second duration is reset. And when performing hot water heating processing as water quality improvement processing, in addition to stopping hot water heating processing by detecting temperature in a set low temperature range with tank upper hot water temperature sensor St, a tank bottom part Even when the hot water temperature sensor Sb detects a temperature within the set high temperature range, it is determined that the water quality of the hot water tank 2 is improved, and the hot water heating process is stopped.

  Further, in the present embodiment, as described above, when the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is lower than the determination reference temperature (for example, 37 ° C.), the operation control unit 5 For example, the operation control unit 5 is configured such that the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is lower than the determination reference temperature in the water quality improvement process. The hot water heating process is executed both when the temperature is equal to or higher than the determination reference temperature.

  That is, in the present embodiment, when the operation control unit 5 performs the hot water supply heating process, when the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is lower than the determination reference temperature (for example, 37 ° C.), The hot water supply auxiliary heater 24 is heated so as to be heated to a heating reference temperature (for example, 60 ° C.). In addition, the temperature of hot water supplied to the hot water supply auxiliary heater 24 is equal to or higher than the determination reference temperature. However, when the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is lower than the hot water supply target temperature, the hot water supply auxiliary heater 24 is heated so as to heat the hot water to the heating reference temperature (for example, 60 ° C.). However, in the water quality improvement process, the operation control unit 5 sets the heating reference temperature (for example, 60 ° C.) to whatever temperature the hot water supplied to the hot water supply auxiliary heater 24 is. Heating hot water It becomes Rukoto.

The set low temperature range is set to a range lower than the determination reference temperature at which the hot water supply auxiliary heater 24 performs the heating operation. As described above, the determination reference temperature is set to a temperature obtained by adding a set increase temperature (for example, 5 ° C.) to the lower limit value (for example, 32 ° C.) of the temperature range that can be commanded by the operation remote controller R.
That is, when the temperature of the hot water is in the range below the determination reference temperature, the hot water is heated to the heating reference temperature (for example, 60 ° C.) by the hot water supply auxiliary heater 24 to improve the water quality. The low temperature range is set to a range lower than the determination reference temperature at which the hot water supply auxiliary heater 24 performs the heating operation.

  Further, the operation control unit 5 determines the temperature within the set high temperature range, which is predicted as the temperature of the hot water when heated in the hot water storage heat exchanger 22 and then exists in the hot water storage tank 2, as a bath bottom hot water temperature sensor Sb. When the second continuation time in which the state not detected is continued is equal to or longer than the second set allowable time, it is determined that it is the water quality improvement timing, and the water quality improvement process is executed, and the water quality improvement process is executed. Accordingly, the first duration time and the second duration time are reset to zero.

In other words, the operation control unit 5 starts measuring the second duration when the temperature detected by the bath bottom hot water temperature sensor Sb is lower than the set high temperature range, and the temperature detected by the bath bottom hot water temperature sensor Sb is the set high temperature. In a state where the second duration is reset to 0 when the temperature is within the range, the second duration is measured, and when the second duration exceeds the second set allowable time, it is determined that it is the water quality improvement timing, It is comprised so that a water quality improvement process may be performed.
And as the water quality improvement process, the operation control unit 5 performs the above-described hot water heating process until the temperature in the set high temperature range is detected by the tank bottom hot water temperature sensor Sb, or the temperature in the set low temperature range is set to the bath upper hot water. The process is executed until it is detected by the temperature sensor St.

The set high temperature range is set to a temperature range of 60 ° C. or more, for example.
Further, the first setting allowable time is set to 96 hours, for example, and the second setting allowable time is also set to 96 hours, for example.

  As described above, in the present embodiment, when the water quality improvement timing is determined, as the water quality improvement process, hot water is supplied so that the hot water flowing through the hot water supply passage 17 is heated to a heating reference temperature (for example, 60 ° C.) that improves the water quality. Since the hot water heating process for operating the auxiliary heater 24 is performed until the improvement in the water quality of the hot water tank 2 is determined, it is possible to suppress the supply of hot water with reduced water quality.

Hereinafter, the control operation of the operation control unit 5 will be described based on a flowchart.
First, the control operation for the entire system will be described based on the flowchart shown in FIG.
In the following description, among the devices equipped in the cogeneration system, the control operation related to the fuel cell 1 and the auxiliary hot water heater 24 for hot water supply will be described, and the cooling water circulation pump 15 and the hot water circulation pump will be described. A description of the control operation for other devices such as 19 will be omitted.

First, it is determined whether or not it is the start time of the operation cycle (# 1), and if it is determined that it is the start time of the operation cycle, an operation mode setting process is executed (# 2). A fuel cell operation process for operating the fuel cell 1 in the determined operation mode is executed (# 3).
When it is determined in the process of # 1 that it is not the start point of the operation cycle, the process proceeds to the fuel cell operation process of # 3.
The operation mode setting process, as described above, varies the operation time zone in which the fuel cell 1 is operated based on the time-series predicted power load and the time-series predicted heat load, and the fuel cell for the predicted power load. This is a process for obtaining the operation merit for a plurality of types of operation forms with different power output forms of 1 and determining the operation form having the highest obtained operation merit as the operation form of the fuel cell 1.

Next, it is determined whether or not the water quality improvement process is being executed (# 4). When it is determined that the water quality improvement process is not being executed, the duration time for measuring the first duration time t1 and the second duration time t2 is determined. When the measurement process is executed (# 5) and then it is determined that the first duration t1 is smaller than the first set allowable time L1 and the second duration t2 is smaller than the second set allowable time L2 (# 6, 7) After performing the hot water supply heating process (# 8), the process proceeds to the process of # 1.
In the hot water supply heating process, when the temperature of the hot water supplied to the auxiliary hot water heater 24 is lower than the determination reference temperature (for example, 37 ° C.), the hot water is heated to the heating reference temperature (for example, 60 ° C.). The temperature of hot water supplied to the hot water supply auxiliary heater 24 is increased even when the temperature of the hot water supplied to the hot water supply auxiliary heater 24 is equal to or higher than the determination reference temperature. When the temperature is lower than the target hot water supply temperature, the hot water supply auxiliary heater 24 is heated so as to heat the hot water to the heating reference temperature (for example, 60 ° C.).

When it is determined in the processes of # 6 and 7 that the first duration t1 is equal to or longer than the first set allowable time L1, or the second duration t2 is equal to or longer than the second set allowable time L2, (# 9)
The hot water heating process is a process of operating the hot water supply auxiliary heater 24 so as to heat the hot water flowing through the hot water supply path 17 to a heating reference temperature (for example, 60 ° C.) that improves the water quality as the water quality improving process. is there.
Also, when it is determined in the process of # 4 that the water quality improvement process is being executed, the process proceeds to the hot water heating process of # 9.

After the # 9 hot water heating process is executed, the tank upper hot water temperature sensor St detects the temperature within the set low temperature range, or the tank bottom temperature sensor Sb detects the set high temperature range. It is determined whether or not the hot water storage tank 2 is in a water quality improved state (# 10). If it is determined that the water quality is in an improved state, stop of the water quality improving process is set (# 11).
If it is determined in the process of # 10 that the hot water tank 2 is not in a state of improving the water quality, or after the stop of the water quality improvement process of # 11 is set, the process proceeds to the process of # 1.

Next, the duration measurement process will be described based on the flowchart shown in FIG.
First, it is determined whether or not the first duration measurement timer that measures the first duration t1 is operating (# 21).
The first duration measurement timer is in a state where the temperature in the set low temperature range is not detected by the tank upper hot water temperature sensor St, that is, the detected temperature Tt of the tank upper hot water temperature sensor St is higher than the upper limit temperature Rt in the set low temperature range. Is a timer that measures the first duration t1 that continues.
When it is determined at # 21 that the first duration measurement timer is not operating, it is determined whether or not the detected temperature Tt of the tank upper hot water temperature sensor St is higher than the upper limit temperature Rt of the set low temperature range (# 22). ).

When it is determined at # 22 that the detected temperature Tt of the tank upper hot water temperature sensor St is higher than the upper limit temperature Rt of the set low temperature range, the operation of the first duration measurement timer is started (# 23).
Subsequently, it is determined whether or not the detected temperature Tt of the tank upper hot water temperature sensor St is equal to or lower than the upper limit temperature Rt of the set low temperature range (# 24). The time t1 and the second duration t2 are reset to 0 (# 25).

  When it is determined at # 22 that the detected temperature Tt of the tank upper hot water temperature sensor St is not higher than the upper limit temperature Rt of the set low temperature range, the detected temperature Tt of the tank upper hot water temperature sensor St is set lower at # 24. When it is determined that the temperature is not lower than the upper limit temperature Rt of the range, and after the process of # 25 is executed, the process proceeds to # 26.

The process of # 26 is a process of determining whether or not the second duration measurement timer that measures the second duration t2 is operating.
In the second duration measurement timer, the state in which the temperature within the set high temperature range is not detected by the tank bottom temperature sensor Sb, that is, the state where the detection temperature Tb of the tank bottom temperature sensor Sb is lower than the lower limit temperature Rb of the set high temperature range continues. This is a timer for measuring the second duration t2.
When it is determined at # 26 that the second duration measurement timer is not operating, it is determined whether or not the detected temperature Tb of the tank bottom temperature sensor Sb is lower than the lower limit temperature Rb of the set high temperature range (# 27). .

When it is determined at # 27 that the detected temperature Tb of the tank bottom temperature sensor Sb is lower than the lower limit temperature Rb of the set high temperature range, the operation of the second duration measurement timer is started (# 28).
Subsequently, it is determined whether or not the detected temperature Tb of the tank bottom temperature sensor Sb is equal to or higher than the lower limit temperature Rb of the set high temperature range (# 29). The time t1 and the second duration t2 are reset to zero.

  When it is determined at # 27 that the detected temperature Tb of the tank bottom temperature sensor Sb is not lower than the lower limit temperature Rb of the set high temperature range, at # 29, the detected temperature Tb of the tank bottom temperature sensor Sb is the lower limit of the set high temperature range. When it is determined that the temperature is not equal to or higher than the temperature Rb, and after executing the process of # 30, the process returns to the process of # 6.

That is, in this duration measurement process, when the detected temperature Tt of the tank upper hot water temperature sensor St is equal to or lower than the upper limit temperature Rt of the set low temperature range, the heating reference temperature that can improve the water quality by the heating operation of the hot water supply auxiliary heater 24. Since the hot water in the hot water storage tank 2 can be heated, the first continuous time t1 and the second continuous time t2 are set to 0 when the detected temperature Tt of the hot water temperature sensor St below the upper limit temperature Rt of the set low temperature range. Reset.
Further, when the detection temperature Tb of the tank bottom temperature sensor Sb is equal to or higher than the lower limit temperature Rb of the set high temperature range, the entire hot water tank 2 or substantially the whole is filled with hot water heated by the hot water storage heat exchanger 22. Since the hot water quality of the hot water storage tank 2 is in a good state, when the detected temperature Tb of the tank bottom temperature sensor Sb is equal to or higher than the lower limit temperature Rb of the set high temperature range, the first duration t1 and the second duration are continued. Reset time t2 to zero.

[Second Embodiment]
Hereinafter, although 2nd Embodiment is described, this 2nd Embodiment demonstrates another embodiment of the process which discriminate | determines water quality improvement timing, Comprising: The other structure is the same as that of 1st Embodiment. Therefore, the process for determining the water quality improvement timing will be mainly described, and the other description will be omitted.

  In the second embodiment, the tank upper hot water temperature sensor St, the intermediate upper hot water temperature sensor Sm, the intermediate lower hot water temperature sensor Sn and the tank bottom hot water temperature sensor Sb described in the first embodiment are connected to the bottom of the hot water tank 2. Are provided in a state of being spaced apart from the top to be used as a plurality of hot water temperature detecting means for detecting the temperature of the hot water in the hot water tank 2.

  The operation control unit 5 has a first continuation time in which a temperature higher than the set low temperature range is detected by at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb for a first set allowable time or more. Then, it is determined that it is the water quality improvement timing, and the same water quality improvement processing as that of the first embodiment is executed.

In other words, the operation control unit 5 starts measuring the first duration when at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb detects a temperature higher than the set low temperature range. When the detected temperatures of all the hot water temperature sensors St, Sm, Sn, Sb are within the set low temperature range, the first duration is measured in a state where the first duration is reset to 0, and When the first duration time is equal to or longer than the first set allowable time, the water quality improvement process is executed.
Moreover, when the hot water heating process is executed as the water quality improvement process, the hot water heating process is stopped by detecting the temperatures within the set low temperature range by all of the plurality of hot water temperature sensors St, Sm, Sn, and Sb. To do.

  Incidentally, in the present embodiment, as described below, the second duration time in which the state in which the temperature lower than the set high temperature range is detected by at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is continued. Is set to be the water quality improvement timing when the second set allowable time or more, the water quality improvement process is configured to be executed. For this reason, all of the plurality of hot water temperature sensors St, Sm, Sn, Sb are configured. When the detected temperature reaches a temperature within the set low temperature range, the second duration is reset in addition to resetting the first duration to 0. Then, when the hot water heating process is being executed as the water quality improvement process, the hot water heating process is stopped by detecting the temperature within the set low temperature range by all of the plurality of hot water temperature sensors St, Sm, Sn, Sb. In addition, when all of the plurality of hot water temperature sensors St, Sm, Sn, Sb detect temperatures within the set high temperature range, it is determined that the water quality of the hot water tank 2 is improved, and the hot water heating process is performed. Is configured to stop running.

  As described above, the operation control unit 5 sets the temperature lower than the set high temperature range predicted as the temperature of the hot water when heated in the hot water storage heat exchanger 22 and then present in the hot water tank 2 to a plurality of hot water. When the second duration time as the non-high temperature duration duration for continuing the state detected by at least one of the temperature sensors St, Sm, Sn, and Sb is equal to or longer than the second set allowable time, it is determined that it is the water quality improvement timing. And it is comprised so that the water quality improvement process similar to 1st Embodiment may be performed, and it is comprised so that 1st continuation time and 2nd continuation time may be reset to 0 with execution of water quality improvement processing. ing.

  In other words, the operation control unit 5 starts measuring the second duration when at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb detects a temperature lower than the set high temperature range. When the detected temperatures of all the hot water temperature sensors St, Sm, Sn, and Sb are within the set high temperature range, the second duration time is measured with the first duration time and the second duration time reset to zero. When the second continuation time is equal to or longer than the second set allowable time, the water quality improving process is executed.

  The first setting allowable time, the second setting allowable time, the setting low temperature range, and the setting high temperature range are set in the same manner as in the first embodiment.

Hereinafter, based on the flowchart shown in FIG. 4, the duration measurement process will be described in the second embodiment.
First, it is determined whether or not the first duration measurement timer that measures the first duration t1 is operating (# 51).
The first duration measurement timer measures a first duration t1 in which at least one detected temperature of the plurality of hot water temperature sensors St, Sm, Sn, Sb continues to be higher than the upper limit temperature of the set low temperature range. It is a timer.
When it is determined in # 51 that the first duration measurement timer is not operating, at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is detected higher than the upper limit temperature of the set low temperature range Or not (# 52).

If it is determined in # 52 that at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is higher than the upper limit temperature of the set low temperature range, the first duration measurement timer is activated. Start (# 53).
Subsequently, it is determined whether or not all the detected temperatures of the plurality of hot water temperature sensors St, Sm, Sn, Sb are equal to or lower than the upper limit temperature of the set low temperature range (# 54). At 55, the first duration t1 and the second duration t2 are reset to zero.

  When it is determined at # 52 that at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is not higher than the upper limit temperature of the set low temperature range, at # 54, the plurality of hot water temperatures When it is determined that all the detected temperatures of the sensors St, Sm, Sn, and Sb are not less than or equal to the upper limit temperature of the set low temperature range, and after the process of # 55 is executed, the process proceeds to # 56.

The process of # 56 is a process of determining whether or not the second duration measurement timer that measures the second duration t2 is operating.
The second duration measurement timer measures a second duration t2 in which a state where at least one detected temperature of the plurality of hot water temperature sensors St, Sm, Sn, Sb is lower than the lower limit temperature of the set high temperature range continues. It is a timer.
When it is determined at # 56 that the second duration measurement timer is not operating, at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is detected lower than the lower limit temperature of the set high temperature range Or not (# 57).

If it is determined in # 57 that at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is lower than the lower limit temperature of the set high temperature range, the second duration measurement timer is activated. Start (# 28).
Subsequently, it is determined whether or not all the detected temperatures of the plurality of hot water temperature sensors St, Sm, Sn, Sb are equal to or higher than the lower limit temperature of the set high temperature range (# 29). In # 60, the first duration t1 and the second duration t2 are reset to zero.

  When it is determined at # 57 that at least one of the plurality of hot water temperature sensors St, Sm, Sn, Sb is not lower than the lower limit temperature of the set high temperature range, at # 59, the plurality of hot water temperature sensors When it is determined that all the detected temperatures of St, Sm, Sn, and Sb are not equal to or higher than the lower limit temperature of the set high temperature range, and after the process of # 60 is executed, the process returns to the process of # 6.

That is, in this duration measurement process, when all the detected temperatures of the plurality of hot water temperature sensors St, Sm, Sn, Sb are equal to or lower than the upper limit temperature Rt of the set low temperature range, the heating operation of the hot water supply auxiliary heater 24 Since it can be heated to a heating reference temperature that can improve the quality of the hot water in the hot water tank 2, when all the detected temperatures of the plurality of hot water temperature sensors St, Sm, Sn, Sb are below the upper limit temperature Rt of the set low temperature range, The first duration time t1 and the second duration time t2 are reset to zero.
When all the detected temperatures of the plurality of hot water temperature sensors St, Sm, Sn, Sb are equal to or higher than the lower limit temperature Rb of the set high temperature range, the entire hot water tank 2 is heated by the hot water storage heat exchanger 22. The hot water in the hot water tank 2 is in a good state, and all the detected temperatures of the hot water temperature sensors St, Sm, Sn, Sb are within the set high temperature range. When the temperature becomes lower than the lower limit temperature Rb, the second duration t2 is reset to zero.

[Third Embodiment]
Hereinafter, although 3rd Embodiment is described, this 3rd Embodiment demonstrates another embodiment of the control action | operation about the auxiliary heater 24 for hot water supply, Comprising: Other structure is 1st Embodiment. Since this is the same, the control operation for the hot water supply auxiliary heater 24 will be mainly described, and the other description will be omitted.

  In the third embodiment, when the temperature of hot water supplied to the hot water supply auxiliary heater 24 is lower than the target hot water temperature set by the remote controller R as the hot water heating process, The hot water supply auxiliary heater 24 is operated so as to heat the hot water flowing through the passage 17 to the hot water supply target temperature, and the hot water flowing through the hot water supply passage 17 is less than the hot water supply target temperature as a water quality improvement process. The hot water heating process is executed both at the time and when the temperature is equal to or higher than the hot water supply target temperature.

  In other words, in the hot water heating process, the operation control unit 5 detects the flow rate of hot water flowing into the heat exchanger h while the flow rate sensor detects a flow rate higher than the set flow rate. If the inflow temperature detected (the temperature of hot water supplied to the hot water supply auxiliary heater 24) is lower than the hot water supply target temperature, the burner b is burned to heat the hot water, and the flow rate sensor The hot water is heated to the target hot water temperature by feedforward control based on the flow rate detected by the inflow temperature sensor and the inflow temperature detected by the inflow temperature sensor and feedback control based on the outflow temperature detected by the outflow temperature sensor. Therefore, the amount of combustion of the burner b is adjusted, and if the detected flow rate of the flow sensor becomes less than the set flow rate during combustion of the burner b, the burner b is extinguished.

  In addition, in the hot water heating process in the water quality improvement process, the operation control unit 5 detects the flow rate of the hot water flowing into the heat exchanger h while the flow rate sensor detects a flow rate higher than the set flow rate. If the inflow temperature (temperature of the hot water supplied to the hot water supply auxiliary heater 24) detected at is lower than the heating reference temperature (for example, 60 ° C.), the burner b is burned to heat the hot water. And feed-forward control based on the flow rate detected by the flow sensor and the inflow temperature detected by the inflow temperature sensor, and feedback control based on the outflow temperature detected by the outflow temperature sensor, In order to heat the hot water to the heating reference temperature (for example, 60 ° C.), the combustion amount of the burner b is adjusted, and the detected flow rate of the flow sensor during the combustion of the burner b is the set flow rate. It becomes fully, thereby to extinguish the burner b.

  By the way, when the hot water heating process in the water quality improvement process is executed, the temperature of the hot water supplied from the hot water supply path 17 is adjusted to the hot water supply target temperature by the mixing valve 34 as in the first embodiment. Become.

  In addition, the operation control unit 5 determines that the first duration as the non-low temperature duration for continuing the state in which the temperature within the set low temperature range is not detected by the tank upper hot water temperature sensor St is the first setting allowance as the low temperature allowable time. If it is over time, it is determined that it is time to improve the water quality, and as a water quality improvement process, the hot water supply auxiliary so as to heat the hot water flowing through the hot water supply path 17 to a heating reference temperature (for example, 60 ° C.) that improves the water quality. The hot water heating process for operating the heater 24 is executed, and when the temperature within the set low temperature range is detected by the tank upper hot water temperature sensor St, it is determined that the water quality of the hot water storage tank 2 is improved, and the hot water heating process is performed. Is configured to stop running.

In other words, the operation control unit 5 starts measuring the first duration when the detected temperature of the tank upper hot water temperature sensor St becomes higher than the set low temperature range, and the detected temperature of the tank upper hot water temperature sensor St becomes the set low temperature. In a state where the first duration time is reset to 0 when the temperature falls within the range, the first duration time is measured, and when the first duration time exceeds the first set allowable time, it is determined that it is the water quality improvement timing, Water quality improvement processing will be executed.
And the operation control part 5 will perform the above-mentioned hot-water heating process as a water quality improvement process until the temperature in a setting low temperature range is detected by the tank upper hot-water temperature sensor St.

  Incidentally, in the present embodiment, as described later, the second duration time as the non-high temperature duration time during which the tank bottom hot water temperature sensor Sb does not detect the temperature within the set high temperature range is set as the high temperature allowable time. When the time is equal to or longer than the second set allowable time, it is configured to execute the water quality improvement process as the water quality improvement timing. For this reason, the temperature detected by the tank upper hot water temperature sensor St is a temperature within the set low temperature range. Then, in addition to resetting the first duration to 0, the second duration is reset. And when performing hot water heating processing as water quality improvement processing, in addition to stopping hot water heating processing by detecting temperature in a set low temperature range with tank upper hot water temperature sensor St, a tank bottom part Even when the hot water temperature sensor Sb detects a temperature within the set high temperature range, it is determined that the water quality of the hot water tank 2 is improved, and the hot water heating process is stopped.

The set low temperature range is set to a temperature obtained by adding an allowable set temperature (for example, 5 ° C.) to the temperature of hot water flowing through the water supply passage 16 detected by the water supply temperature sensor Si.
That is, when hot water supplied through the water supply channel 16 is present in the hot water storage tank 2 without being heated by the hot water storage heat exchanger 22, heat from the hot water stored in the hot water storage tank 2 is stored. Even if the temperature rises due to conduction or the like, an allowable temperature increase value capable of maintaining the quality of the hot water in a good state is obtained by experiment, and the allowable temperature increase value is determined as an allowable set temperature (for example, 5 ° C.).

  In addition, as described above, the operation control unit 5 sets the temperature within the set high temperature range, which is predicted as the temperature of the hot water when heated in the hot water storage heat exchanger 22 and then exists in the hot water storage tank 2, to the bottom of the tank. When the second duration time for continuing the state not detected by the hot water temperature sensor Sb is equal to or longer than the second set allowable time, it is determined that it is the water quality improvement timing, and the water quality improvement process is executed. The first duration time and the second duration time are reset to 0 as the improvement process is executed.

In other words, the operation control unit 5 starts measuring the second duration when the temperature detected by the bath bottom hot water temperature sensor Sb is lower than the set high temperature range, and the temperature detected by the bath bottom hot water temperature sensor Sb is the set high temperature. In a state where the second duration is reset to 0 when the temperature is within the range, the second duration is measured, and when the second duration exceeds the second set allowable time, it is determined that it is the water quality improvement timing, It is comprised so that a water quality improvement process may be performed.
And as the water quality improvement process, the operation control unit 5 performs the above-described hot water heating process until the temperature in the set high temperature range is detected by the tank bottom hot water temperature sensor Sb, or the temperature in the set low temperature range is set to the bath upper hot water. The process is executed until it is detected by the temperature sensor St.

The set high temperature range is set to a temperature range of 60 ° C. or more, for example.
Further, the first setting allowable time is set to 96 hours, for example, and the second setting allowable time is also set to 96 hours, for example.

  As described above, in the present embodiment, when the water quality improvement timing is set, as the water quality improvement process, the hot water flowing through the hot water supply passage 17 is heated to the heating reference temperature (for example, 60 ° C.) that improves the water quality. Since the hot water heating process for operating the auxiliary heater 24 is performed until it is determined that the water quality of the hot water storage tank 2 has been improved, it is possible to prevent hot water having a lowered water quality from being supplied.

Incidentally, the control operation of the third embodiment is the same as the control operation of the first embodiment and has the same contents as the flowcharts of FIGS.
In addition, when implementing 3rd Embodiment, the structure of said 2nd Embodiment can be used for the structure which discriminate | determines a water quality improvement timing. Incidentally, in the case of using the configuration of the second embodiment, the set low temperature range is equal to the temperature of hot water flowing through the water supply path 16 detected by the water supply temperature sensor Si, as described above, and an allowable set temperature (for example, 5 ℃) plus the temperature.

[Another embodiment]
Next, another embodiment will be described.
(B) In each of the above-described embodiments, the tank upper hot water temperature sensor St is provided so as to detect the temperature of the hot water in the upper part of the hot water tank 2, but the temperature is adjusted by being sent from the upper part of the hot water tank 2. It may be provided in a flow path portion connecting the upper portion of the hot water tank 2 and the hot water supply auxiliary heater 24 in the hot water supply passage 17 so as to detect the temperature of the hot water existing in the hot water supply passage 17 without any problem.
Further, in each of the above embodiments, the bath bottom hot water temperature sensor Sb is provided so as to detect the temperature of the hot water at the bottom of the hot water tank 2, but the temperature is adjusted by being sent from the bottom of the hot water tank 2. Alternatively, it may be provided in a flow path portion connecting the bottom of the hot water storage tank 2 and the hot water storage heat exchanger 22 in the hot water storage circuit 18 so as to detect the temperature of the hot water existing in the hot water storage circuit 18.

(B) In the first and second embodiments described above, the determination reference temperature at which the hot water supply auxiliary heater 24 as the hot water supply heating means is heated can be commanded by the operation remote controller R as the hot water supply target temperature command means. In this example, the temperature is set to a value obtained by adding a set increase temperature (for example, 5 ° C.) to the lower limit value of the correct temperature range, but the determination reference temperature is set to the lower limit value of the temperature range that can be commanded by the operation remote controller It is also possible to implement.
Moreover, the hot water target temperature which is set as a fixed value in advance by the mixing valve 34 as the mixing means for the hot water heated to the heating reference temperature by the auxiliary heater 24 for hot water supply without providing the hot water target temperature command means. In the case of hot water supply adjusted to (for example, 42 ° C.), the determination reference temperature is set to a hot water supply target temperature set in advance as a fixed value. The reference temperature may be set to a temperature obtained by adding a set temperature (for example, 5 ° C.) to a hot water supply target temperature set in advance as a fixed value.

(C) In the above embodiment, the operation mode having the maximum predicted energy reduction amount among the plurality of types of operation modes is determined as the operation mode of the fuel cell 1, and the fuel cell 1 is operated in the determined operation mode. However, the fuel cell 1 may be operated in a preset operation mode, for example, a current power load following operation. Further, among the plurality of types of operation modes, an operation mode in which the predicted carbon dioxide reduction amount is high or the predicted utility cost merit is increased is defined as the fuel cell 1 operation mode, and the fuel cell 1 is operated in the determined operation mode. You may comprise so that it may drive | operate.

(D) In the above embodiment, the case where the heating unit H is configured to use the heat generated from the fuel cell 1 as an example of the combined heat and power supply as a heat source is exemplified. However, the gas burner, the electric heater, and the electric type A dedicated heat source such as a heat pump may be provided, and heat generated from an engine-driven heat pump that drives a compressor by a gas engine, a gasoline engine, or the like may be used as a heat source.
When the heating unit H is configured to use heat generated from the combined heat and power supply as a heat source, the combined heat and power supply is not limited to the fuel cell 1 illustrated in the above embodiment, for example, an engine driven rotary type. A power generation device can be applied.

(E) In the above embodiment, the case where the plurality of hot water temperature sensors St to Sb are configured by using both the tank upper portion hot water temperature sensor St and the tank bottom portion hot water temperature sensor Sb is illustrated. Instead of the tank bottom hot water temperature sensor Sb, a plurality of hot water temperature sensors may be configured by separately providing an upper hot water temperature sensor and a tank bottom temperature sensor.
And in the said embodiment, although the case where four sensors were juxtaposed as a some hot water temperature sensor St-Sb was illustrated, three sensors may be juxtaposed and five or more sensors are juxtaposed. It can also be implemented.

(F) The mixing means constituted by the mixing valve 34 or the like does not necessarily have to be provided as a component of the hot water supply device, for example, when the automatic adjustment type mixing tap is provided at the hot water supply location.

(G) In the above embodiment, the hot water storage tank 2 is sealed, and hot water is supplied to the hot water supply path 17 by the water supply pressure of the water supply path 16, but the hot water storage tank 2 is open to the atmosphere and the hot water supply of the hot water supply pump is used. You may comprise so that hot water supply may be carried out by force.

(H) In the first and second embodiments, the heating reference temperature that can improve the quality of hot water when the temperature of the hot water supplied as the heating means 24 for hot water supply is lower than the determination reference temperature. However, when the temperature of the hot water in the upper part of the hot water tank 2 is lower than the judgment reference temperature, the hot water is heated to a heating reference temperature that can improve the quality of the hot water. It may be configured and implemented.

(L) In the above embodiment, the case where the hot water supply heating means 24 as the hot water supply heating means is provided as a dedicated hot water supply heating means for heating the hot water flowing through the hot water supply passage 17 is illustrated. However, you may implement in the form combined with the heating means for the heating of the heat-consuming terminal 3.
That is, for example, a heating circulation path that connects a location upstream and downstream of the hot water supply heating means in the hot water supply channel 17 is provided via the heat consuming terminal 3, and hot water is provided in the heating circulation path. By arranging a circulation pump that circulates, the heating means for hot water supply can be used also as the heating means for heating the heat consuming terminal 3.

(Nu) The configuration for determining the water quality improvement timing is not limited to the configuration described in the above embodiment, and various configurations can be used.
For example, a flow sensor that detects the amount of hot water supplied to the hot water tank in the water supply channel, a flow sensor that detects the flow rate of hot water circulated from the bottom of the hot water tank to the upper part of the hot water tank, and the upper part of the hot water tank Of the hot water supplied from the bottom of the hot water tank, it is circulated from the bottom of the hot water tank to the top of the hot water tank using the time-series detection information of each flow sensor that detects the amount of hot water supplied. Without the hot water being supplied from the upper part of the hot water tank, the hot water remaining in the hot water tank is determined to determine the storage overtime in the hot water tank, and when the storage time exceeds the allowable time, You may make it discriminate | determine that it is a water quality improvement timing.

(L) Water quality improvement timing is determined based on detection information from the bath top hot water temperature detection means, the bath bottom hot water temperature detection means, and a plurality of hot water temperature detection means located at intervals from the bottom to the top of the hot water storage tank. The specific values of the set values to be used for the first setting allowable time, the second allowable setting time, the set high temperature range, and the set low temperature range are the same as the set values exemplified in the above embodiment. It is not limited and can be set to various values.
In the above embodiment, the first setting allowable time and the second setting allowable time are set to the same time, but may be set to different times.

(E) In the above embodiment, based on the detection information of the bath top hot water temperature detection means, the bath bottom hot water temperature detection means, and a plurality of hot water temperature detection means located at intervals from the bottom to the top of the hot water tank, In determining the water quality improvement timing, the first embodiment exemplifies a case where a tank upper hot water temperature detecting means for detecting the set low temperature range and a tank bottom hot water temperature detecting means for detecting the set high temperature range are used. In the second embodiment, the case where a plurality of hot and cold water temperature detection means are used to detect the set low temperature range and the set high temperature range is exemplified, but various changes can be made.

For example, it may be implemented so as to include only the tank upper hot water temperature detecting means for detecting the set low temperature range, or only including the tank bottom hot water temperature detecting means for detecting the set high temperature range. You may implement.
In addition, it may be implemented in such a manner that only a set low temperature range is detected by a plurality of hot water temperature detection means, or is a set high temperature range determined by a plurality of hot water temperature detection means? You may implement in the form which makes it detect only whether it is no.
Furthermore, detecting the set low temperature range by the tank upper hot water temperature detecting means, detecting the set high temperature range by the tank bottom hot water temperature detecting means, detecting the set low temperature range by a plurality of hot water temperature detecting means, And, the set high temperature range may be detected by a plurality of hot and cold water temperature detecting means in a combined form.

  When the description is added, in the above embodiment, for example, in the first embodiment, the first continuation time t1 in which the tank upper hot water temperature sensor St continues the state where the temperature in the set low temperature range is not detected is the first set allowable time L1. If it becomes above, it will discriminate | determine that it is a water quality improvement timing, and also when the 2nd continuation time t2 in which the tank bottom part warm water temperature sensor Sb continues the state which does not detect the temperature in a setting high temperature range will become more than 2nd setting permissible time L2. In the second embodiment, the first continuation time t1 during which the plurality of hot water temperature sensors St to Sb continue to detect no temperature within the set low temperature range is the first setting. When the allowable time L1 is exceeded, it is determined that it is a water quality improvement timing, and further, the state where the plurality of hot water temperature sensors St to Sb do not detect the temperature within the set high temperature range is continued. When the second duration t2 is equal to or longer than the second set allowable time L2, the case where the second duration t2 is measured in addition to the measurement of the first duration t1 is exemplified, for example, it is determined that it is the water quality improvement timing. The configuration for measuring the second duration t2 can be omitted, and the configuration for executing the water quality improvement process can be omitted when the second duration t2 is equal to or longer than the second set allowable time L1.

As described above, in the case where the second duration t2 is omitted and the second duration t2 is equal to or longer than the second set allowable time L1, the configuration for executing the water quality improvement process is omitted. You may make it increase the structure which resets 1 continuation time t1.
That is, for example, when the first continuation time t1 during which the tank upper hot water temperature sensor St does not detect the temperature within the set low temperature range is equal to or greater than the first set allowable time L1, the water quality improvement process is executed. When the tank bottom portion hot water temperature sensor Sb detects a temperature within the set high temperature range before the first duration t1 becomes equal to or longer than the first set allowable time L1, the first duration t1 is reset to 0. Similarly, the plurality of hot water temperature sensors St to Sb detect temperatures within the set low temperature range or the set high temperature range until the first duration t1 becomes equal to or longer than the first set allowable time L1. When the temperature inside is detected, the first duration t1 can be reset to zero.

  When the first continuation time t1 in which the plurality of hot water temperature sensors St to Sb do not detect the temperature within the set low temperature range is equal to or longer than the first set allowable time L1, the water quality improvement process is executed. When the tank bottom hot water temperature sensor Sb detects a temperature within the set high temperature range, the first duration t1 can be reset to 0. Similarly, the first duration t1 is the first duration t1. When the plurality of hot water temperature sensors St to Sb detect the temperature within the set high temperature range or the tank upper temperature water temperature sensor St detects the temperature within the set low temperature range before the set allowable time L1 or more, the first The duration t1 can be configured to be reset to zero.

(W) In performing the hot water heating process as the water quality improvement process, the heating reference temperature is exemplified as a specific value in the above embodiment, but the heating reference temperature is set to 65 ° C., for example. Various changes can be made.

2 Hot water storage tank 5 Operation control means 16 Water supply path 17 Hot water supply path 18 Hot water supply circulation path 19 Hot water circulation means 34 Mixing means H Heating means R Hot water supply target temperature command means Sb Bath bottom hot water temperature detection means, hot water temperature detection means Si Hot water temperature detection means Means Sm Hot water temperature detection means Sn Hot water temperature detection means St Tank upper hot water temperature detection means, hot water temperature detection means

Claims (7)

A hot water storage tank in which water is supplied through a water supply path connected to the bottom and hot water is sent out through a hot water supply path connected to the top;
Hot water circulation means for circulating hot water in the hot water storage tank through the hot water circulation path in the form of returning the hot water taken out from the tank bottom to the upper part of the tank;
Heating means for heating hot water flowing through the hot water circulation circuit;
Heating means for hot water supply for heating hot water flowing through the hot water supply path;
Operation control means for controlling operation is provided,
The operation control means is a hot water storage type hot water supply apparatus configured to execute a water quality improvement process when determining a water quality improvement timing to cope with a water quality deterioration of the hot water storage tank,
The operation control means performs, as the water quality improvement process, a hot water heating process for operating the hot water supply heating means to heat the hot water flowing through the hot water supply path to a heating reference temperature that improves water quality. A hot water storage type hot water supply apparatus configured to be executed until it is determined that the water quality has been improved. A bath upper hot water temperature detecting means for detecting the temperature of hot water present in the hot water supply path without being adjusted by being sent from the upper hot water of the hot water tank or the upper temperature of the hot water tank is provided,
The operation control means includes
Detecting the temperature of the hot water temperature in the upper portion of the tank as a temperature within a set low temperature range that is predicted as the temperature of the hot water when the hot water is supplied to the hot water tank through the water supply channel and is not heated by the heating means. When the non-low temperature continuation time for continuing the state not detected by the means is equal to or higher than the low temperature setting allowable time, it is determined that it is the water quality improvement timing, and
As the water quality improvement process, when the hot water heating process is being performed, if the temperature in the set low temperature range is detected by the tank upper hot water temperature detection means, it is determined that the water quality improvement state of the hot water tank is present. The hot water storage type hot water supply apparatus according to claim 1, which is configured as described in claim 1. A plurality of hot water temperature detection means for detecting the temperature of the hot water in the hot water tank located at an interval from the bottom to the top of the hot water tank is provided,
The operation control means includes
The temperature of the plurality of hot water is higher than a preset low temperature range predicted as the temperature of hot water when the hot water is supplied to the hot water tank through the water supply channel and is not heated by the heating means. When the non-low temperature continuation time for continuing the state detected by at least one of the detection means is equal to or higher than the low temperature setting allowable time, it is determined that it is the water quality improvement processing timing, and
As the water quality improvement process, when the hot water heating process is being performed and the temperature within the set low temperature range is detected by all of the plurality of hot water temperature detection means, the water storage tank is in the water quality improvement state. The hot water storage type hot water supply apparatus according to claim 1, wherein the hot water storage apparatus is configured to discriminate. The operation control means is configured to heat the hot water to the heating reference temperature when the temperature of the hot water supplied to the heating means for hot water supply or the temperature of the hot water at the upper part of the hot water storage tank is lower than the judgment reference temperature. And, as the water quality improvement process, either when the temperature of the hot water supplied to the heating means for hot water supply or the temperature of the hot water at the upper part of the hot water tank is less than the judgment reference temperature or when the temperature is higher than the judgment reference temperature Also, it is configured to execute the hot water heating process,
The hot water storage type hot water supply apparatus according to claim 2 or 3, wherein the set low temperature range is a range lower than the determination reference temperature. A hot water supply target temperature command means for changing and setting the hot water supply target temperature is provided,
Mixing means for mixing hot water from the water supply path with hot water flowing through the hot water supply path to adjust to the hot water supply target temperature is provided,
The hot water storage type hot water supply apparatus according to claim 4, wherein the determination reference temperature is a lower limit value of a temperature range that can be commanded by the hot water supply target temperature command means. A hot water supply target temperature command means for changing and setting the hot water supply target temperature is provided,
Mixing means for mixing hot water from the water supply path with hot water flowing through the hot water supply path to adjust to the hot water supply target temperature is provided,
The hot water storage type hot water supply apparatus according to claim 4, wherein the determination reference temperature is a temperature obtained by adding a set increase temperature to a lower limit value of a temperature range that can be commanded by the hot water supply target temperature command means. A hot water supply target temperature command means for changing and setting the hot water supply target temperature is provided,
Mixing means for mixing hot water from the water supply path with hot water flowing through the hot water supply path to adjust to the hot water supply target temperature is provided,
When the temperature of hot water supplied to the heating means for hot water supply or the temperature of hot water in the upper part of the hot water storage tank is lower than the target hot water supply temperature, the operation control means flows the hot water supply passage to the hot water supply target temperature. A hot water heating process is performed to operate the hot water heating means so as to heat the hot water, and as the water quality improvement process, when the hot water flowing through the hot water supply path is lower than the hot water supply target temperature and above the hot water supply target temperature. The hot water storage type hot water supply apparatus according to any one of claims 1 to 3, wherein the hot water heating process is performed at any time.

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