JP2010276208A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in a hot water storage type water heater that it takes a long time to perform sterilization treatment when the sterilization treatment is performed by a fuel cell or an electric heater of a low heating capacity, and comprehensive energy efficiency is deteriorated since warm water in the hot water storage tank cannot be supplied during the sterilization treatment, and the hot water is supplied by heating the tap water and the like by a heat source machine. <P>SOLUTION: The warm water distributed from the hot water storage tank 2 is heated by the heat source machine 3, and the warm water is returned to the hot water storage tank 2 after consuming the warm water necessary for hot water supply. The warm water in the hot water storage tank can be heated by the heating performance of the heat source machine in the sterilization treatment, and the warm water in the hot water storage tank can be sterilized in a short time. Thus the warm water stored in the hot water storage tank can be used in hot water supply and the like at an early point, a time for directly heating the tap water and the like by the heat source machine to be used for hot water supply can be shortened, and energy efficiency can be improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the present invention, exhaust heat generated by power generation in a power generation unit such as gas power generation and fuel cell is stored in a hot water storage tank, and the hot water stored in the hot water storage tank is used for reheating hot water and baths, and further for heating. With regard to the intended hot water storage type hot water supply device, in particular, when the hot water in the hot water storage tank has not been used for a long time, the hot water storage type hot water containing the Legionella bacteria from the hot water storage tank is prevented from being supplied to the hot water supply or bathtub. It relates to the device.

  Hot water storage water heaters have been developed for the purpose of storing exhaust heat generated by the power generation of gas generators, fuel cells, etc. in hot water storage tanks, replenishing hot water and bathing, and heating. . This type of hot water storage type hot water supply device uses the exhaust heat generated by the power generation of the power generation unit for hot water supply, etc., so it is more energy efficient than a system that uses a burner or the like to directly heat tap water and supply hot water. . However, since the waste heat generated by the power generation unit is once stored in the hot water storage tank, if the hot water stored in the hot water storage tank is not used for a long time, germs may propagate in the hot water inside the hot water storage tank, which is particularly harmful to the human body. When there is a possibility that miscellaneous bacteria have propagated, there is a demand for a hot water storage type hot water supply apparatus in which the hot water in the hot water storage tank is used for hot water supply after being sterilized. An example of such a hot water storage type hot water supply apparatus is described in Patent Document 1.

  As shown in FIG. 4, a conventional hot water storage type hot water supply apparatus includes a fuel cell 5, a hot water storage tank 10, an electric heater 27, a hot water supply passage 30, a heat source unit 31, a hot water supply side three-way valve 32, and a hot water supply. The waste heat generated by the power generation of the fuel cell 5 is stored in the hot water storage tank 10 as hot water. Hot water stored in the hot water storage tank 10 flows through the hot water supply path 30 and is supplied through the hot water supply side three-way valve 32 and the heat source unit 31. When the hot water stored in the hot water storage tank 10 has not been used for a long time, the hot water stored in the hot water storage tank 10 is prevented from flowing into the hot water supply path 30 by operating the hot water supply side three-way valve 32. In addition, the hot water stored in the hot water storage tank 10 is heated by the fuel cell 5 or the electric heater 27 so that fresh water supplied from the hot water supply flow channel 51 side can flow into the hot water supply passage 30 and is heated. Sterilize warm water. At this time, hot water is used by heating fresh water flowing into the hot water supply path 30 from the hot water supply water supply path 51 side by the heat source unit 31.

  According to this form, the hot water stored in the hot water storage tank 10 can be reliably sterilized, and hot water can be supplied even during the sterilization process.

JP 2006-349323 A

  However, in the conventional configuration, the means for reheating the hot water in the hot water storage tank at the time of sterilization is a fuel cell or an electric heater. Generally, these heating means have a heating capability lower than that of a heat source machine that directly heats with a burner or the like. . Therefore, it takes a considerable amount of time to complete the sterilization process. During that time, not only can the hot water in the hot water storage tank be used for hot water supply, but also tap water is heated by a heat source machine and used for hot water supply. There was a problem that energy efficiency deteriorated.

  The present invention solves the above-described conventional problems, and uses hot water stored in a hot water storage tank or hot water heated by a heat source machine for a plurality of purposes such as hot water supply, bathing, and heating. It is an object of the present invention to provide a hot water storage type hot water supply apparatus that enables sterilization in a short time and has improved energy efficiency.

  In order to solve the above-described conventional problems, the hot water storage type hot water supply apparatus according to the present invention is configured such that hot water sent from a hot water storage tank is heated by a heat source unit, and the hot water consumes the hot water required for hot water supply. It is set as the structure returned to.

  According to the above invention, since the hot water supplied from the hot water storage tank is heated by the heat source machine and then returned to the hot water storage tank, it is possible to heat the hot water in the hot water storage tank with the heating capacity of the heat source machine during the sterilization process. Thus, the hot water inside the hot water storage tank can be sterilized in a short time. Thus, the hot water stored in the hot water storage tank can be used for hot water supply at an early stage, and the time for directly heating tap water or the like by the heat source device to use it for hot water supply can be reduced, so that energy efficiency can be improved.

  According to the hot water storage type hot water supply apparatus of the present invention, the overall energy efficiency can be enhanced by sterilizing the hot water storage tank in a short time.

The block diagram of the hot water storage type hot water supply apparatus in Embodiment 1 of this invention The block diagram of the hot water storage type hot water supply apparatus in Embodiment 2 of this invention The block diagram of the hot water storage type hot water supply apparatus in Embodiment 3 of this invention Configuration diagram of a conventional hot water storage hot water supply system

  According to a first aspect of the present invention, during the sterilization process, the hot water heated from the lower part of the hot water storage tank is heated to the upper part of the hot water storage tank after the hot water required for the hot water supply is consumed. By sterilizing the hot water in the hot water storage tank using the machine, the sterilization can be performed in a short time, and the energy efficiency can be increased. In addition, by diverting the path for guiding the hot water to the hot water supply on the path for returning the hot water heated by the heat source device to the hot water storage tank, the hot water supply can be used even during sterilization, and convenience may be impaired. Absent.

  In the second invention, a path for returning the hot water heated by the heat source machine of the first invention to the upper part of the hot water tank is added to the middle part of the hot water tank, and the hot water passing through the heat source machine is returned to the upper part of the hot water tank. It is possible to maintain the temperature stratification state of the hot water tank even when the temperature of the hot water passing through the heat source device is low, by selecting whether to return to the middle part of the hot water tank or hot water tank. It is possible to supply hot water having a stable temperature.

  In the third invention, a path for returning the hot water heated by the heat source machine of the first invention to the upper part of the hot water storage tank is added to the heat source machine, and the hot water passing through the heat source machine is returned to the upper part of the hot water tank. Even if the temperature of the hot water passing through the heat source device is low, the temperature stratified state of the hot water storage tank can be maintained even when the temperature of the hot water passing through the heat source device is low, and the temperature is stable for hot water supply, bath or heating. Hot water can be supplied.

According to a fourth aspect of the present invention, in particular, the amount of heat used for sterilization in any one of the first to third aspects is increased or decreased according to a change in the amount of heat used for hot water supply during sterilization. Even in a state where the heat source is used, the heating capacity of the heat source machine can be used to the maximum, and the sterilization process can be performed in a short time, thereby improving the energy efficiency.

  According to a fifth aspect of the present invention, in particular, in any one of the first to fourth aspects of the present invention, a means for determining the end of the sterilization process is provided. The hot water is blocked from being supplied to the heat source tank, and the hot water is supplied from the upper part of the hot water storage tank to the heat source machine, so that the hot water in the hot water storage tank can be used for hot water supply. Thereby, a sterilization process can be completed without excess and deficiency of heat amount, and energy efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a configuration diagram of a hot water storage type hot water supply apparatus according to Embodiment 1 of the present invention. As a basic configuration, a power generation unit 1 that generates power such as gas power generation or a fuel cell, a hot water storage tank 2 that recovers and stores exhaust heat generated by power generation, and hot water stored in the hot water storage tank 2 is lower than the hot water temperature required for hot water supply In this case, a heat source device 3 for heating the hot water stored is provided.

  The power generation unit 1 includes an exhaust heat recovery heat exchanger 20 and an exhaust heat circulation pump 21. The power generation unit 1 drives the exhaust heat circulation pump 21 to transfer the hot water in the hot water storage tank 2 to the exhaust heat recovery heat exchanger 20 via the exhaust heat recovery circulation path 22 connected to the lower part of the hot water storage tank 2. send. The hot water sent to the exhaust heat recovery heat exchanger 20 is heated by the exhaust heat recovery heat exchanger 20 using the exhaust heat generated by the power generation unit 1 generating power. The hot water heated by the exhaust heat recovery heat exchanger 20 is returned to the upper part of the hot water storage tank 2 via the exhaust heat recovery circulation return path 23.

  The heat source unit 3 includes a burner 31 and a heat exchanger 32 as in a conventionally known water heater, and heats hot water by burning fuel such as gas or petroleum. High heating capacity.

  When the hot water tap 6 is opened in order to perform hot water supply when the user is not in a special operation state such as during sterilization, the feed water amount sensor 10 serving as the feed water amount detection means connected to the water supply path 8. Detects the flow of water and sends a signal to the hot water storage unit controller 11. Here, it is determined by the hot water storage unit controller 11 whether hot water is being used.

  When the hot water storage unit controller 11 determines that hot water is being used, the hot water stored in the hot water storage tank 2 passes through the heat source water supply path 7, the heat source unit 3, and the hot water circulation path 16 connected to the upper part of the hot water storage tank 2. The hot water circulation path 16 is routed to the hot water supply path 17, and the hot water supply path 9 branched from the water supply path 8 and connected to the hot water supply path 17 is mixed with tap water and led to the hot water tap 6. .

  At this time, the heat source water supply shut-off valve 40, which is an openable and closable heat source water supply passage shut-off means provided in the heat source water supply passage 7 in order to shut off the hot water supplied from the upper part of the hot water storage tank 2 to the heat source machine 3, is open. In this state, it is possible to supply hot water from the upper part of the hot water storage tank 2 to the heat source unit 3. Further, the heating / water supply path 15 for supplying hot water from the lower part of the hot water storage tank 2 to the heat source apparatus 3 and the heating / water supply path blocking means that can be opened and closed provided to interrupt the hot water supplied from the lower part of the hot water storage tank 2 to the heat source apparatus 3. The hot water supply shutoff valve 41 is closed, and the supply of hot water from the lower part of the hot water storage tank 2 to the heat source unit 3 is shut off.

The ratio of the amount of hot water mixed to the hot water tap 6 is determined by the hot water storage unit controller 11, a hot water temperature signal requested by the user sent from the remote controller 12, and a temperature signal of the first hot water thermistor 50 attached to the hot water supply path 17, The temperature signal of the water supply thermistor 51 attached to the water supply path 8, the temperature signal of the hot water circulation thermistor 52 attached to the hot water circulation path 16, and the detected water amount of the water supply water quantity sensor 10 are within the maximum heating capacity range of the heat source unit 3. Thus, the hot water supply amount control 13 and the hot water supply amount control 14 are controlled so that the mixed hot water temperature guided to the hot water tap 6 becomes the hot water supply temperature required by the user, and the distribution of the mixed water amount is adjusted.

  Here, the temperature of the hot water supplied from the upper part of the hot water storage tank 2 to the heat source unit 3 is detected by the heat source water supply thermistor 60 attached to the heat source water supply path 7, and the temperature of the hot water supplied from the upper part of the hot water storage tank 2 to the heat source unit 3 is Since the hot water at the hot water temperature required by the user can be supplied to the hot-water tap 6 without heating the hot water by the heat source device 3 if the hot water temperature is higher than that required by the user, the heat source device 3 does not perform the heating operation. It is controlled by the hot water storage unit controller 11. On the contrary, the hot water storage unit controller 11 controls to perform the heating operation of the heat source device 3 when the temperature of the hot water put from the upper part of the hot water storage tank 2 to the heat source device 3 is lower than the hot water supply temperature requested by the user.

  The sterilization process is performed when the hot water stored in the hot water storage tank 2 is not used for hot water supply or the like for a long time after the use of the hot water supply is completed. The hot water storage unit controller 11 determines based on the conditions, and the sterilization process is started.

  When the sterilization process is started, the heat source water cutoff valve 40 provided in the heat source water supply path 7 is closed, and the heating water supply cutoff valve 41 provided in the heating water supply path 15 is opened. This cuts off the supply of hot water from the upper part of the hot water storage tank 2 to the heat source unit 3 and allows the supply of hot water from the lower part of the hot water storage tank 2 to the heat source unit 3. Next, a hot water circulation pump 18 that is hot water circulation means for circulating hot water in the hot water circulation path 16 provided in the hot water circulation path 16 in a predetermined direction is driven by a signal from the hot water storage unit controller 11.

  When the hot water circulation pump 18 is driven, the hot water in the hot water storage tank 2 is supplied from the lower part of the hot water storage tank 2 to the heat source device 3 and is heated by the heat source device 3. The hot water heated by the heat source device 3 is returned to the upper part of the hot water storage tank 2 via the hot water circulation path 16. At this time, the heat source unit 3 is in a state of performing a heating operation by a signal from the hot water storage unit controller 11, and is set to perform heating to a temperature (for example, 85 ° C.) at which miscellaneous bacteria such as Legionella bacteria are instantly killed. . Thereby, the hot water sterilized via the heat source device 3 is gradually accumulated from the upper part of the hot water storage tank 2, and finally all the hot water in the hot water storage tank 2 is sterilized.

  When the hot water tap 6 is opened by the user during the sterilization process and hot water is used, hot water sterilized by the heat source unit 3 flowing through the hot water circulation path 16 is placed in the hot water supply path 17 to supply hot water. Even when hot water is being used by the user, the hot water circulation pump 18 is driven, whereby the hot water heated by the heat source unit 3 and sterilized is placed on the hot water storage tank 2, and the hot water in the hot water storage tank 2 is sterilized. Do hot water supply at the same time.

  According to this form, since the sterilization process of the hot water stored in the hot water storage tank 2 can be performed using the heating capacity of the heat source unit 3 having a higher heating capacity than the power generation unit 1, the sterilization process is performed using the power generation unit 1. Sterilization can be completed faster than it can. As a result, the hot water stored in the hot water storage tank 2 can be used for hot water supply at an early stage, and the time for directly heating tap water or the like by the heat source unit 3 to use it for hot water supply can be reduced, so that energy efficiency can be improved. . Further, even during the sterilization process, the user can use the hot water supply without impairing the convenience of the user.

(Embodiment 2)
FIG. 2 is a configuration diagram of a hot water storage type hot water supply apparatus according to Embodiment 2 of the present invention. In FIG. 2, the same components as those in FIG.

  The hot water storage type hot water supply apparatus of FIG. 2 uses hot water stored in the hot water storage tank 2 and uses the hot water flowing in the hot water circulation path 16 and the hot water for the bath heat exchanger 4 for heat exchange with the hot water tank 4 for the hot water storage tank 2. A circulation three-way valve 26 is provided as a switching means for selecting whether to return to the intermediate part or to return to the upper part of the hot water storage tank 2.

  When the user performs a bath retreat when the user is not in a special operation state such as during sterilization, a signal is sent to the hot water storage unit controller 11 when the user operates the remote controller 12 to retreat the bath. When the hot water storage unit controller 11 receives a bath reheating signal from the remote controller 12, the hot water circulating pump 18 is driven and the bath electromagnetic valve 25 provided in the bath hot water circulation path 19 is opened, so that the hot water in the hot water storage tank 2 becomes a heat source. It is placed in the heat source unit 3 via the water supply path 7.

  The hot water supplied to the heat source unit 3 is not heated by the heat source unit 3 if the temperature is higher than the temperature required for bathing by the temperature detected by the heat source water supply thermistor 60 attached to the heat source water supply path 7. The hot water storage path controller 16 controls the hot water storage unit controller 11 so that it is heated by the heat source unit 3 and sent to the hot water circulation path 16 if the temperature is lower than the temperature required for bathing. The hot water supplied to the hot water circulation path 16 is guided to the bath hot water circulation path 19 branched from the hot water circulation path 16 and is heat-exchanged by the bath heat exchanger 4. The hot water heat-exchanged by the bath heat exchanger 4 is returned to the hot water storage tank 2 via the hot water circulation path 16.

  At this time, whether the hot water flowing through the hot water circulation path 16 via the bath heat exchanger 4 is returned to the upper part of the hot water tank 2 or to the intermediate part of the hot water tank 2 is selected depending on the temperature detected by the hot water circulation thermistor 52. The Specifically, if the temperature detected by the hot water circulation thermistor 52 is higher than the temperature required for hot water supply or bathing, the circulating three-way valve 26 is driven by a signal from the hot water storage unit controller 11 and the hot water tank 2 is heated above the hot water tank 2. When the temperature detected by the hot water circulation thermistor 52 is lower than the hot water temperature required for hot water supply or bathing, the circulation three-way valve 26 is driven and the hot water storage tank is connected via the tank side hot water circulation path 27. 2 Warm water is returned to the middle part.

  When bathing is performed during sterilization, the heat source water supply shutoff valve 40 is closed and the heating water supply shutoff valve 41 is open, and hot water is supplied from the lower part of the hot water storage tank 2 to the heat source unit 3. The hot water heated to a temperature (for example, 85 ° C.) at which miscellaneous bacteria such as Legionella bacteria are instantly killed by the heat source device 3 is guided to the bath hot water circulation path 19 by opening the bath electromagnetic valve 25. The hot water guided to the bath hot water circulation path 19 is subjected to heat exchange by the bath heat exchanger 4 and returned to the hot water storage tank 2 via the hot water circulation path 16. At this time, when the temperature detected by the hot water circulation thermistor 52 is higher than that of the hot water storage thermistor 62 as temperature detection means attached to the hot water storage tank 2, the circulation three-way valve 26 is driven and the hot water is returned to the upper part of the hot water storage tank 2. When the temperature detected by the hot water circulation thermistor 52 is lower than the hot water storage thermistor 62, the circulation three-way valve 26 is driven and the hot water is returned to the intermediate portion of the hot water storage tank 2.

  According to this form, even if the temperature of the hot water returned to the hot water storage tank 2 via the hot water circulation path 16 is low, the temperature stratification state of the upper layer portion of the hot water storage tank 2 is not destroyed, and the upper layer of the hot water storage tank 2 The hot water in the section is stable and does not fall below the hot water temperature required for hot water supply or bathing. As a result, it is possible to continue supplying hot water having a stable temperature to hot water supply or bathing.

(Embodiment 3)
FIG. 3 is a configuration diagram of a hot water storage type hot water supply apparatus according to Embodiment 3 of the present invention. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted.

  The hot water storage type hot water supply apparatus of FIG. 3 includes a circulation three-way valve 26 which is a switching means for selecting whether to return the hot water flowing through the hot water circulation path 16 to the heat source water supply path 7 or to the upper part of the hot water storage tank 2.

  In FIG. 3, as in the second embodiment, when the user retreats the bath when not in a special operation state such as during sterilization, the hot water storage unit controller 11 drives the hot water circulation pump 18 and bath hot water circulation path. The hot water in the hot water storage tank 2 is placed in the heat source unit 3 via the heat source water supply path 7 by opening the electromagnetic valve 25 for bath provided in 19.

  If the hot water put in the heat source machine 3 is higher than the temperature required for bathing, the hot water is put in the hot water circulation path 16 without being heated by the heat source machine 3, and is lower than the temperature required for bathing. If it is a temperature, it is heated by the heat source device 3 and sent to the hot water circulation path 16.

  The hot water supplied to the hot water circulation path 16 is guided to the bath hot water circulation path 19 branched from the hot water circulation path 16 and is heat-exchanged by the bath heat exchanger 4. The hot water heat-exchanged by the bath heat exchanger 4 is returned to the hot water storage tank 2 via the hot water circulation path 16.

  At this time, whether the hot water flowing through the hot water circulation path 16 via the bath heat exchanger 4 is returned to the upper part of the hot water tank 2 or the heat source water supply path 7 is selected depending on the temperature detected by the hot water circulation thermistor 52. . Specifically, if the temperature detected by the hot water circulation thermistor 52 is higher than the temperature required for hot water supply or bathing, the circulating three-way valve 26 is driven by a signal from the hot water storage unit controller 11 and the hot water tank 2 is heated above the hot water tank 2. When the temperature detected by the hot water circulation thermistor 52 is lower than the hot water temperature required for hot water supply or bathing, the circulation three-way valve 26 is driven and the heat source water supply is made via the circulation bypass path 28. Hot water is returned to the path 7.

  Even in the case of performing bath replenishment during the sterilization process, similarly to the second embodiment, hot water is supplied from the lower part of the hot water storage tank 2 to the heat source unit 3. The hot water heated by the heat source device 3 is guided to the bath hot water circulation path 19 by opening the bath electromagnetic valve 25 and is heat-exchanged by the bath heat exchanger 4. The hot water exchanged by the bath heat exchanger 4 is returned to the hot water storage tank 2 via the hot water circulation path 16. At this time, when the temperature detected by the hot water circulation thermistor 52 is higher than that of the hot water storage thermistor 62 as temperature detection means attached to the hot water storage tank 2, the circulation three-way valve 26 is driven and the hot water is returned to the upper part of the hot water storage tank 2. When the temperature detected by the hot water circulation thermistor 52 is lower than that of the hot water storage thermistor 62, the circulation three-way valve 26 is driven and the hot water is returned to the heat source water supply path 7.

  According to this form, even if the temperature of the hot water returned to the hot water storage tank 2 via the hot water circulation path 16 is low, the temperature stratification state of the upper layer portion of the hot water storage tank 2 is not destroyed, and the upper layer of the hot water storage tank 2 The hot water in the section is stable and does not fall below the hot water temperature required for hot water supply or bathing. As a result, it is possible to continue supplying hot water having a stable temperature to hot water supply or bathing.

(Embodiment 4)
Next, the effect of increasing energy efficiency by changing the amount of heat used for sterilization in accordance with the amount of heat used for hot water supply during sterilization during the sterilization will be described with reference to FIG.

  In FIG. 1, when the sterilization process is started, the heat source water cutoff valve 40 is closed and the heating water cutoff valve 41 is opened. Hot water is supplied from the lower part of the hot water storage tank 2 to the heat source unit 3, and the hot water heated to a temperature (for example, 85 ° C.) at which various germs such as Legionella bacteria are instantly killed by the heat source unit 3 is returned to the upper part of the hot water storage tank 2. At this time, the amount of heat used for the sterilization treatment is set in advance within the maximum heating capacity range of the heat source unit 3. The amount of heat used for the sterilization process is obtained by subtracting the amount of heat used for hot water supply from the amount of heat heated by the heat source unit 3.

  Specifically, the amount of heat heated by the heat source unit 3 is determined by the heat source water thermistor 42 that is the temperature detection unit for the hot water flowing into the heat source unit 3 installed in the heat source unit 3 and the heat source that is the temperature detection unit for the heated hot water. It is determined by a signal from a heat source flow sensor 44 which is a means for detecting the amount of hot water flowing through the hot water thermistor 43 and the heat source unit 3.

  Further, the amount of heat used for hot water supply includes a hot water temperature signal requested by a user sent from the remote controller 12, a temperature signal of the first hot water supply thermistor 50 attached to the hot water supply path 17, and a water supply thermistor 51 attached to the water supply path 8. , The temperature signal of the hot water circulation thermistor 52 attached to the hot water circulation path 16, and the detected water amount of the feed water amount sensor 10.

  During the sterilization process, the amount of heat used for the sterilization process is controlled to be maximum within the maximum heating capacity range of the heat source unit 3. Specifically, the amount of heat used for sterilization is changed so that the sum of the amount of heat used for sterilization and the amount of heat used for hot water supply becomes the maximum heating capacity of the heat source unit 3. When hot water is not used during the sterilization process, the circulation pump 18 is driven by a signal from the hot water storage unit controller 11 so that the amount of heat used for the sterilization process becomes the maximum heating capacity of the heat source apparatus 3 and flows through the heat source apparatus 3. When the amount of hot water is adjusted and hot water is used during sterilization, the circulation pump 18 is driven so that the total amount of heat used for hot water and sterilization is the maximum heating capacity of the heat source unit 3. The amount of hot water flowing through the machine 3 is adjusted. That is, during the sterilization process, if the amount of heat used for hot water supply increases, the amount of heat used for sterilization process decreases, and if the amount of heat used for hot water supply decreases, the amount of heat used for sterilization process increases. To do.

  According to such a form, during the sterilization process, the amount of heat used for the sterilization process is adjusted so that the heating capacity of the heat source unit 3 is used to the maximum extent. Thereby, even when hot water is used during the sterilization process, the sterilization process can be performed in a short time, and the sterilization process can be completed faster than the sterilization process using the power generation unit 1. The hot water stored in the tank 2 can be used for hot water supply at an early stage, and the heat source device 3 directly heats tap water or the like to reduce the time used for hot water supply or the like, thereby improving the energy efficiency.

(Embodiment 5)
Next, when the end of the sterilization process is determined using FIG. 1, the hot water is blocked from being supplied from the lower part of the hot water storage tank to the heat source unit, and the hot water is supplied from the upper part of the hot water storage tank to the heat source unit. The effect of increasing the level will be described.

  In FIG. 1, the hot water storage type hot water supply apparatus of the present embodiment includes a sterilization end determination unit. Further, a plurality of hot water storage thermistors 61 to 64 for detecting the temperature of hot water stored in the hot water storage tank 2 are attached to the hot water storage tank 2.

The end of the sterilization process is determined by the hot water storage unit controller 11 based on the temperature of the hot water in the hot water storage tank 2 detected by the hot water storage thermistors 61 to 64 and the total amount of heat used for the sterilization process after the start of the sterilization process. Specifically, the total amount of heat used for sterilization after the start of sterilization is the minimum amount of heat required to sterilize all hot water stored in the hot water storage tank 2 at the start of sterilization. When the temperature detected by the hot water storage thermistors 61 to 64 reaches a preset temperature that allows the end of the sterilization process (for example, 80 ° C.), the hot water storage unit controller 11 determines that the sterilization process has ended. To do.

  The minimum amount of heat required for the sterilization process at the start of the sterilization process is the temperature detected by the hot water storage thermistor 64 at the start of the sterilization process, and a preset temperature (for example, determined to be surely sterilized) 80 ° C.) and the capacity of the hot water storage tank, the minimum amount of heat necessary to sterilize all the hot water stored in the hot water storage tank 2 can be obtained.

  When it is determined by the hot water storage unit controller 11 that the sterilization process has been completed, the heat source water supply shutoff valve 40 provided in the heat source water supply path 7 is opened by a signal from the hot water storage unit controller 11, and the heating provided in the heating water supply path 15. The water supply shutoff valve 41 is closed. Thereby, the hot water is supplied from the upper part of the hot water storage tank to the heat source machine, and the hot water in the hot water storage tank can be used for hot water supply or the like.

  According to such a form, since the determination of the end of the sterilization process is determined by the minimum amount of heat required for the sterilization process and the hot water temperature in the hot water storage tank 2, the hot water stored in the hot water storage tank is Sterilized reliably. Furthermore, since the hot water in the upper part of the hot water storage tank 2 is automatically switched to the form that uses the hot water tank 2 after completion of the sterilization process, the sterilization process can be completed without excess or shortage of heat necessary for the sterilization process, and energy efficiency can be improved. it can.

  The hot water storage type hot water supply apparatus of the present invention can be sterilized in a short time, and can be applied to a hot water supply apparatus that can use hot water or a bath even during sterilization.

1 Power generation section (gas power generation, fuel cell)
2 Hot water storage tank 3 Heat source machine 4 Bath heat exchanger 6 Hot water tap 7 Heat source water supply path 8 Water supply path 9 Hot water supply water supply path 10 Water supply amount sensor (Water supply amount detection means)
DESCRIPTION OF SYMBOLS 11 Hot water storage unit controller 12 Remote control 13 Hot water supply amount control 14 Hot water supply amount control 15 Heating water supply route 16 Hot water circulation route 17 Hot water supply route 18 Hot water circulation pump (hot water circulation means)
DESCRIPTION OF SYMBOLS 19 Bath warm water circulation path 20 Heat exchanger for waste heat recovery 21 Waste heat circulation pump 22 Waste heat recovery circulation path 23 Waste heat recovery circulation return path 25 Bath solenoid valve 26 Circulation three-way valve (switching means)
27 Tank side hot water circulation path 28 Circulation bypass path 31 Burner 32 Heat exchanger 40 Heat source water supply shutoff valve (heat source water supply path shutoff means)
41 Heating water supply passage cutoff valve (Heating water supply passage cutoff means)
42 Heat input water thermistor (temperature detection means)
43 Heat source hot water thermistor (temperature detection means)
44 Heat source flow sensor (Water volume detection means)
50 First hot water supply thermistor 51 Water supply thermistor 52 Hot water circulation thermistor 60 Heat source water supply thermistor 61-64 Hot water storage thermistor

Claims (5)

A hot water storage tank, a heat source device for heating the hot water supplied from the hot water storage tank, a heat source water supply route for supplying the hot water in the upper part of the hot water storage tank to the heat source device, and the heat source water supply route are provided in the heat source water supply passage so as to be openable and closable The heat source water supply path blocking means, the hot water circulation path for returning the hot water heated by the heat source device to the upper part of the hot water storage tank, the hot water circulation means for circulating the hot water in the hot water circulation path in a predetermined direction, and the hot water A hot water supply path branched from the hot water circulation path upstream of the circulation means to supply hot water to the hot water tap, and heating to supply the hot water (or water) below the hot water storage tank to the heat source water supply path downstream from the heat source water supply path blocking means Sterilization comprising a water supply path and a heating water supply path blocking means provided in the heating water supply path so that the heating water supply path can be opened and closed, and sterilizing the entire hot water storage tank with hot water When performing the physical operation, the heating / water supply path blocking means is opened to heat the hot water (or water) below the hot water storage tank with the heat source unit, and when performing the normal hot water storage operation, the heating supply path blocking means is A hot water storage type hot water supply device that closes and circulates hot water in the upper part of the hot water storage tank. The tank-side hot water circulation path branched from the hot water circulation path downstream from the hot water circulation means and returning the hot water heated by the heat source machine to the intermediate portion of the hot water storage tank, and the hot water heated by the heat source machine, The switching means for selecting whether to return to the said hot water storage tank intermediate part using a tank side hot water circulation path, or to return to the said hot water storage tank upper part without using the said tank side hot water circulation path. Hot water storage water heater. A circulation bypass path that branches from the hot water circulation path downstream from the hot water circulation means and passes the hot water heated by the heat source apparatus to the water supply path, and the hot water heated by the heat source apparatus is passed through the circulation bypass path. 2. The hot water storage type hot water supply apparatus according to claim 1, further comprising switching means for selecting whether to use the heat source water supply path or return to the upper part of the hot water storage tank without using the circulation bypass path. The amount of heat used for the sterilization process falls within the maximum heating capacity range of the heat source machine and decreases when the amount of heat used for hot water supply during the sterilization process increases, and the amount of heat used for hot water supply during the sterilization process decreases. The hot water storage type hot water supply apparatus according to any one of claims 1 to 3, wherein the hot water storage apparatus increases. The sterilization process end means for determining the end of the sterilization process is provided, and when the sterilization process end determination means determines the end of the sterilization process, the heat source water supply path blocking means is opened and the heated water supply path blocking means is closed. The hot water storage type hot water supply apparatus according to any one of claims 1 to 4, wherein the hot water storage type hot water supply apparatus is provided.