JP2011158161A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress variation of temperature of hot water supplied to a hot water supply terminal. <P>SOLUTION: In a water heater, after mixing hot water flowing out of an intermediate outflow part (a second outflow part) of a hot water storage tank and water supplied from a water supply source at a first mixing valve, the mixed water is mixed to hot water flowing out of an upper outflow part (a first outflow part) of the hot water storage tank at a second mixing valve to be supplied to the first hot water supply terminal. A determinator of the water heater determines whether it allows the hot water flowing out of the intermediate outflow part to pass the first mixing valve or not based on flow rate of hot water supply to the first hot water supply terminal. When the determinator determines that it does not allow the hot water flowing out of the intermediate outflow part to pass the first mixing valve during supplying hot water to the hot water supply terminal, a controller of the water heater controls the first mixing valve so as to pass a decreased amount of the hot water which has flowed out of the intermediate outflow part through the first mixing valve. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus that uses hot water flowing out from an intermediate portion of a hot water storage tank for hot water supply.

  2. Description of the Related Art Conventionally, as a hot water supply apparatus, there is one that mixes hot water taken out from an upper part of a hot water storage tank and water supplied from a water supply source and supplies the mixture to a hot water supply terminal. In such a hot water supply apparatus, normally, the temperature of the hot water in the hot water storage tank is high in the upper part, low in the lower part, and intermediate in the intermediate part.

  Moreover, in this hot water supply apparatus, in order to improve thermal efficiency, the hot water supply apparatus which takes out warm water from the intermediate part of a hot water storage tank and uses it for hot water supply is proposed. Specifically, the hot water taken out from the intermediate part of the hot water storage tank and the water supplied from the water supply source are mixed by the first mixing valve, and then the mixed hot water and the hot water taken out from the upper part of the hot water storage tank are mixed together. There is a hot water supply device that mixes with two mixing valves and supplies the hot water supply terminal (for example, see Patent Document 1).

JP 2006-226593 A

  However, in the hot water supply apparatus mentioned above, there exists a problem that the temperature of the hot water supplied to a hot water supply terminal changes with the fluctuation | variation of the flow volume of the hot water supplied to a hot water supply terminal. For example, in a hot water supply apparatus in which a check valve is arranged closer to the water supply source than the first mixing valve, when the flow rate of hot water supplied to the hot water supply terminal is considerably reduced, water flowing into the check valve from the water supply source Since the flow rate is considerably reduced, the check valve cannot be completely opened, and the flow rate of water passing through the check valve may be further reduced. In this case, even if the opening degree of the first mixing valve is constant, the mixing ratio varies so that the ratio of the water supplied from the water supply source decreases, and the temperature of the hot water mixed by the first mixing valve is changed. As a result, the temperature of the hot water supplied to the hot water supply terminal rises.

Further, the hot water supply apparatus described above is provided with another outflow part (hereinafter referred to as a third outflow part) in the hot water storage tank in addition to the upper outflow part and the intermediate outflow part described above, and is mixed by the second mixing valve. The hot water flowing out from the third outflow section is supplied to a hot water supply terminal (hereinafter referred to as a second hot water supply terminal) different from the hot water supply terminal (hereinafter referred to as a first hot water supply terminal) to which hot water is supplied. There may be.
In this hot water supply device, when the flow rate of hot water supplied to the second hot water supply terminal decreases during hot water supply to the first hot water supply terminal, the flow rate flowing out from the hot water storage tank through the third outflow part decreases, The flow rate flowing out from the hot water storage tank through the intermediate outflow portion and the upper outflow portion may increase. And if the flow volume which flows out from an intermediate outflow part increases, even if the opening degree of a 1st mixing valve is constant, the ratio of the warm water which flowed out from the intermediate outflow part in the 1st mixing valve will increase, and the 1st mixing valve The problem arises that the temperature of the mixed hot water rises.

  Then, this invention is made | formed in order to solve the above subjects, and it aims at providing the hot-water supply apparatus which can suppress the fluctuation | variation of the temperature of the hot water supplied to a hot-water supply terminal.

  In order to solve the above problems, a hot water supply apparatus according to a first aspect of the present invention includes a heating means for heating hot water, a hot water storage tank for storing hot water heated by the heating means, and hot water flowing out from an upper portion of the hot water storage tank. And a first mixing valve for mixing the hot water flowing out from the second outflow portion and the water supplied from the water supply source. A second mixing valve that mixes the hot water mixed by the first mixing valve and the hot water flowing out from the first outflow portion; and a first hot water supply terminal to which the hot water mixed by the second mixing valve is supplied Determining means for determining whether or not the hot water flowing out from the second outflow part is allowed to pass through the first mixing valve based on a hot water supply flow rate to the first hot water supply terminal; And a control means for controlling the mixing valve and the second mixing valve. When the determination means determines that the passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted in the determination means, the first mixing valve of the hot water flowing out from the second outflow portion The first mixing valve is controlled so as to reduce the amount of passage of the gas.

In this hot water supply apparatus, the first mixing valve is switched so as to reduce the passage amount of the hot water flowing out from the second outflow portion in accordance with the hot water supply flow rate to the first hot water supply terminal. When the check valve is arranged closer to the water supply source than the first mixing valve, the check valve is switched by switching the first mixing valve as described above when the hot water supply flow rate to the first hot water supply terminal is low. Even if the hot water supply flow rate to the first hot water supply terminal decreases so that the valve cannot be completely opened, it is possible to suppress the temperature of the hot water mixed by the first mixing valve from fluctuating. Therefore, the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.
In addition, by switching the first mixing valve as described above when the hot water supply flow rate to the first hot water supply terminal is low, the first hot water supply terminal becomes more difficult to control the first mixing valve with high accuracy. Even if the hot water supply flow rate is small, fluctuations in the temperature of the hot water mixed by the first mixing valve can be suppressed.

  A hot water supply apparatus according to a second aspect of the present invention is the hot water supply apparatus according to the first aspect of the present invention, wherein water flows only in the direction from the water supply source toward the second mixing valve on the water supply source side of the second mixing valve. A stop valve is provided.

  In this hot water supply device, even if the hot water supply flow rate to the first hot water supply terminal decreases so that the check valve cannot be completely opened, the temperature of the hot water mixed by the first mixing valve is suppressed from fluctuating. can do.

  A hot water supply apparatus according to a third aspect of the present invention is the hot water supply apparatus according to the first or second aspect of the invention, wherein a third outflow portion for flowing out hot water from the hot water storage tank and hot water flowing out from the third outflow portion are supplied. A second hot water supply terminal is provided.

  In this hot water supply apparatus, hot water in the hot water storage tank can be supplied to the second hot water supply terminal in addition to the first hot water supply terminal, and fluctuations in the temperature of the hot water supplied to the first hot water supply terminal can be suppressed.

  A hot water supply apparatus according to a fourth aspect of the present invention is a heating means for heating hot water, a hot water storage tank for storing hot water heated by the heating means, a first outflow portion for discharging hot water from an upper portion of the hot water storage tank, A second outflow portion for flowing hot water from an intermediate portion of the hot water storage tank; a first mixing valve for mixing hot water flowing out from the first outflow portion and hot water flowing out from the second outflow portion; and the first mixing valve A second mixing valve that mixes the hot water mixed in the water supplied from the water supply source, a first hot water supply terminal to which the hot water mixed by the second mixing valve is supplied, and the first hot water supply terminal Determining means for determining whether or not the hot water flowing out from the second outflow portion is allowed to pass through the first mixing valve based on a hot water supply flow rate, the first mixing valve and the second mixing valve; Control means for controlling the control means, wherein the control means is the judgment means. When it is determined that passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted, the passing amount of the hot water flowing out from the second outflow portion through the first mixing valve is decreased. The first mixing valve is controlled as described above.

  In this hot water supply device, when the hot water supply flow rate to the first hot water supply terminal is low, the first mixing valve is switched so as to reduce the passage amount of the hot water flowing out from the second outflow part. Even if the hot water supply flow rate to the first hot water supply terminal is so small that it is difficult to perform the control with high accuracy, it is possible to suppress the temperature of the hot water mixed by the first mixing valve from fluctuating. Therefore, the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.

  A hot water supply apparatus according to a fifth invention is the hot water supply apparatus according to any one of the first to fourth inventions, wherein the control means is the first mixing of the hot water flowing out from the second outflow portion in the determination means. When it is determined that the passage of the valve is not permitted, the first mixing valve is brought into the water supply source side fully opened state.

  In this hot water supply apparatus, since the first mixing valve is switched to the water supply source side fully opened state when the determination means determines not to allow passage of the first mixing valve of the hot water flowing out from the second outflow portion, Variations in the temperature of the hot water mixed by the mixing valve can be reliably suppressed.

  A hot water supply apparatus according to a sixth aspect of the present invention is the hot water supply apparatus according to any one of the first to fifth aspects of the invention, wherein the determining means is configured such that when the hot water supply flow rate to the first hot water supply terminal is a predetermined amount or less, When it is determined that passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted and the hot water supply flow rate to the first hot water supply terminal is larger than a predetermined amount, the outflow from the second outflow portion It is determined that the passage of the hot water having passed through the first mixing valve is permitted.

  In this hot water supply device, when the hot water supply flow rate to the first hot water supply terminal is equal to or less than a predetermined amount, the first mixing valve is switched so as to reduce the passage amount of the hot water flowing out from the second outflow portion. Therefore, when the check valve is arranged closer to the water supply source than the first mixing valve, even if the hot water supply flow rate to the first hot water supply terminal decreases so that the check valve cannot be completely opened, Variations in the temperature of the hot water mixed by the first mixing valve can be suppressed. Moreover, even if there is little warm water supply flow volume to a 1st hot water supply terminal so that it is difficult to control a 1st mixing valve accurately, it suppresses that the temperature of the warm water mixed with the 1st mixing valve fluctuates. Can do.

  A hot water supply apparatus according to a seventh aspect of the present invention is the hot water supply apparatus according to any one of the first to sixth aspects of the invention, wherein the control means causes the second outflow in the determination means when hot water is supplied to the first hot water supply terminal. It is determined that passage of the hot water flowing out from the first mixing valve is not permitted, and the first mixing valve is controlled so as to reduce the passing amount of the hot water flowing out from the second outflow portion through the first mixing valve. After the control, while the hot water is being supplied, even if it is determined that the passage of the first mixing valve of the hot water flowing out from the second outflow portion is permitted in the determination means, while the hot water supply is continued, The opening degree of the first mixing valve is maintained.

  In this hot water supply device, even if the judgment by the judging means changes during hot water supply, the temperature fluctuation that occurs when the opening of the first mixing valve is changed during hot water supply by maintaining the opening of the first mixing valve. Can be prevented.

  A hot water supply apparatus according to an eighth aspect of the present invention is a heating means for heating hot water, a hot water storage tank for storing hot water heated by the heating means, a first outflow portion for discharging hot water from the upper part of the hot water storage tank, Mixing the second outflow part for flowing out hot water from the intermediate part of the hot water storage tank, the third outflow part for flowing out hot water from the hot water storage tank, and the hot water flowing out from the second outflow part and the water supplied from the water supply source The first mixing valve, the second mixing valve for mixing the hot water mixed by the first mixing valve and the hot water flowing out from the first outflow portion, and the hot water mixed by the second mixing valve are supplied. First hot water supply terminal, second hot water supply terminal supplied with hot water flowing out from the third outflow part, and hot water flowing out from the second outflow part based on the hot water supply flow rate to the second hot water supply terminal Determine whether to allow passage through the first mixing valve Determining means, and control means for controlling the first mixing valve and the second mixing valve, wherein the control means is the first mixing valve for hot water flowing out from the second outflow portion in the determining means. When it is determined that the passage of the first mixing valve is not permitted, the first mixing valve is controlled so as to reduce the passing amount of the hot water flowing out from the second outflow portion through the first mixing valve.

  In this hot water supply apparatus, when the hot water supply flow rate to the second hot water supply terminal decreases, the flow rate of hot water flowing out from the third outflow portion decreases, and thus the flow rate out of the second outflow portion increases. When the hot water supply flow rate to the second hot water supply terminal decreases, the hot water supply flow rate to the second hot water supply terminal is changed by switching the first mixing valve so as to reduce the amount of hot water flowing out from the second outflow part. It can suppress that the temperature of the warm water mixed with the 1st mixing valve fluctuates due to the decrease. Therefore, the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.

  A hot water supply apparatus according to a ninth aspect of the invention is the hot water supply apparatus according to the eighth aspect of the invention, wherein the control means does not permit the judgment means to pass the first mixing valve of the hot water flowing out from the second outflow portion. If it is determined, the first mixing valve is set to the water supply source side fully open state.

  In this hot water supply apparatus, the first mixing valve is switched to the water supply source side fully open state, whereby the temperature fluctuation of the hot water mixed by the first mixing valve can be reliably suppressed.

  A hot water supply apparatus according to a tenth aspect of the invention is the hot water supply apparatus according to the eighth or ninth aspect of the invention, wherein the determining means has a decrease amount per unit time of the hot water supply flow rate to the second hot water supply terminal being a predetermined amount or more. In some cases, it is determined that passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted.

  In this hot water supply apparatus, when the amount of decrease in the hot water supply flow rate to the second hot water supply terminal per unit time is greater than or equal to a predetermined amount, the first mixing valve is configured to reduce the passage amount of the hot water flowing out from the second outflow portion. Can be switched to. Therefore, it can suppress that the temperature of the warm water mixed with the 1st mixing valve fluctuates due to the decrease in the flow rate of the warm water supply to the second hot water supply terminal.

  A hot water supply apparatus according to an eleventh aspect of the invention is the hot water supply apparatus according to any of the eighth to tenth aspects of the invention, wherein the judging means is configured to supply the second outflow portion based on a hot water supply flow rate to the first hot water supply terminal. It is determined whether or not to allow the hot water flowing out from the first mixing valve to pass through.

  In this hot water supply apparatus, the determination means makes a determination based on the hot water supply flow rate to the first hot water supply terminal in addition to the determination based on the hot water supply flow rate to the second hot water supply terminal. When the check valve is arranged closer to the water supply source than the first mixing valve, the passage of the hot water flowing out from the second outflow portion when the hot water supply flow rate to the first hot water supply terminal is low Even if the hot water supply flow rate to the first hot water supply terminal is reduced so that the check valve cannot be completely opened by switching so as to reduce the amount, the temperature of the hot water mixed by the first mixing valve is reduced. Fluctuation can be suppressed. In addition, by switching the first mixing valve as described above when the hot water supply flow rate to the first hot water supply terminal is low, the first hot water supply terminal becomes more difficult to control the first mixing valve with high accuracy. Even if the hot water supply flow rate is small, fluctuations in the temperature of the hot water mixed by the first mixing valve can be suppressed.

  A hot water supply apparatus according to a twelfth aspect of the present invention is the hot water supply apparatus according to the eleventh aspect of the present invention, wherein water flows only in the direction from the water supply source toward the second mixing valve on the water supply source side of the second mixing valve. A stop valve is provided.

  In this hot water supply device, even if the hot water supply flow rate to the first hot water supply terminal decreases so that the check valve cannot be completely opened, the temperature of the hot water mixed by the first mixing valve is suppressed from fluctuating. can do.

  A hot water supply apparatus according to a thirteenth aspect of the present invention is the hot water supply apparatus according to any of the eighth to twelfth aspects of the invention, wherein the control means is the determination means when supplying the hot water to the first hot water supply terminal. It is determined that passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted, and the passage amount of the hot water flowing out from the second outflow portion through the first mixing valve is reduced. After the control of one mixing valve, even if it is determined in the determination means that the warm water flowing out from the second outflow portion is allowed to pass through the first mixing valve during the warm water supply, the warm water supply is continued. During the time, the opening degree of the first mixing valve is maintained.

  In this hot water supply device, even if the judgment by the judging means changes during hot water supply, the temperature fluctuation that occurs when the opening of the first mixing valve is changed during hot water supply by maintaining the opening of the first mixing valve. Can be prevented.

  A hot water supply apparatus according to a fourteenth invention is the hot water supply apparatus according to any one of the second and eighth to twelfth inventions, wherein the third outflow portion is provided in an upper part of the hot water storage tank, and the third outflow A third mixing valve that mixes the hot water flowing out from the section and the water supplied from the water supply source, the second hot water supply terminal is supplied with hot water mixed by the third mixing valve, and the control means includes: In addition to controlling the first mixing valve and the second mixing valve, the third mixing valve is also controlled.

  In this hot water supply apparatus, the hot water flowing out from the third outflow part provided in the upper part of the hot water storage tank and the water supplied from the water supply source are mixed in the third mixing valve and supplied to the second hot water supply terminal. The temperature of the hot water supplied to the second hot water supply terminal can be adjusted.

  As described above, according to the present invention, the following effects can be obtained.

In 1st invention, according to the warm water supply flow volume to a 1st hot-water supply terminal, a 1st mixing valve is switched so that the passage amount of the warm water which flowed out from the 2nd outflow part may be decreased. When the check valve is arranged closer to the water supply source than the first mixing valve, the check valve is switched by switching the first mixing valve as described above when the hot water supply flow rate to the first hot water supply terminal is low. Even if the hot water supply flow rate to the first hot water supply terminal decreases so that the valve cannot be completely opened, it is possible to suppress the temperature of the hot water mixed by the first mixing valve from fluctuating. Therefore, the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.
In addition, by switching the first mixing valve as described above when the hot water supply flow rate to the first hot water supply terminal is low, the first hot water supply terminal becomes more difficult to control the first mixing valve with high accuracy. Even if the hot water supply flow rate is small, fluctuations in the temperature of the hot water mixed by the first mixing valve can be suppressed.

  In the second invention, even if the hot water supply flow rate to the first hot water supply terminal decreases so that the check valve cannot be completely opened, the temperature of the hot water mixed by the first mixing valve varies. Can be suppressed.

  In 3rd invention, while adding the hot water in a hot water storage tank to a 1st hot water supply terminal, it can supply to a 2nd hot water supply terminal, and the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.

  In the fourth invention, when the hot water supply flow rate to the first hot water supply terminal is low, the first mixing valve is switched so as to reduce the passing amount of the hot water flowing out from the second outflow part, thereby Even if the hot water supply flow rate to the first hot water supply terminal is so small that it is difficult to perform the control with high accuracy, it is possible to suppress the temperature of the hot water mixed by the first mixing valve from fluctuating. Therefore, the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.

  In the fifth invention, when the judging means judges that the passage of the first mixing valve of the hot water flowing out from the second outflow portion is not permitted, the first mixing valve is switched to the water supply source side fully open state, The fluctuation of the temperature of the hot water mixed by one mixing valve can be reliably suppressed.

  In the sixth aspect of the invention, when the hot water supply flow rate to the first hot water supply terminal is equal to or less than a predetermined amount, the first mixing valve is switched so as to reduce the passage amount of the hot water flowing out from the second outflow portion. Therefore, when the check valve is arranged closer to the water supply source than the first mixing valve, even if the hot water supply flow rate to the first hot water supply terminal decreases so that the check valve cannot be completely opened, Variations in the temperature of the hot water mixed by the first mixing valve can be suppressed. Moreover, even if there is little warm water supply flow volume to a 1st hot water supply terminal so that it is difficult to control a 1st mixing valve accurately, it suppresses that the temperature of the warm water mixed with the 1st mixing valve fluctuates. Can do.

  In the seventh aspect of the invention, the temperature generated when the opening of the first mixing valve is changed during hot water supply by maintaining the opening of the first mixing valve even if the judgment by the judging means changes during hot water supply. Variations can be prevented.

  In the eighth aspect of the invention, when the hot water supply flow rate to the second hot water supply terminal decreases, the flow rate of hot water flowing out from the third outflow portion decreases, so the flow rate out of the second outflow portion increases. When the hot water supply flow rate to the second hot water supply terminal decreases, the hot water supply flow rate to the second hot water supply terminal is changed by switching the first mixing valve so as to reduce the amount of hot water flowing out from the second outflow part. It can suppress that the temperature of the warm water mixed with the 1st mixing valve fluctuates due to the decrease. Therefore, the fluctuation | variation of the temperature of the hot water supplied to a 1st hot water supply terminal can be suppressed.

  In 9th invention, the fluctuation | variation of the temperature of the warm water mixed with the 1st mixing valve can be reliably suppressed by switching a 1st mixing valve to a water supply source side full open state.

  In a tenth aspect of the invention, when the amount of decrease in the hot water supply flow rate to the second hot water supply terminal per unit time is greater than or equal to a predetermined amount, the first mixing valve decreases the amount of warm water flowing out from the second outflow portion. Are switched as follows. Therefore, it can suppress that the temperature of the warm water mixed with the 1st mixing valve fluctuates due to the decrease in the flow rate of the warm water supply to the second hot water supply terminal.

  In the eleventh aspect of the invention, the determination means makes a determination based on the hot water supply flow rate to the first hot water supply terminal in addition to the determination based on the hot water supply flow rate to the second hot water supply terminal. When the check valve is arranged closer to the water supply source than the first mixing valve, the passage of the hot water flowing out from the second outflow portion when the hot water supply flow rate to the first hot water supply terminal is low Even if the hot water supply flow rate to the first hot water supply terminal is reduced so that the check valve cannot be completely opened by switching so as to reduce the amount, the temperature of the hot water mixed by the first mixing valve is reduced. Fluctuation can be suppressed. In addition, by switching the first mixing valve as described above when the hot water supply flow rate to the first hot water supply terminal is low, the first hot water supply terminal becomes more difficult to control the first mixing valve with high accuracy. Even if the hot water supply flow rate is small, fluctuations in the temperature of the hot water mixed by the first mixing valve can be suppressed.

  In the twelfth invention, even if the hot water supply flow rate to the first hot water supply terminal decreases so that the check valve cannot be completely opened, the temperature of the hot water mixed by the first mixing valve varies. Can be suppressed.

  In the thirteenth invention, even if the judgment by the judging means changes during hot water supply, the temperature generated when the opening degree of the first mixing valve is changed during hot water supply by maintaining the opening degree of the first mixing valve. Variations can be prevented.

  In the fourteenth invention, the hot water flowing out from the third outflow portion provided at the upper part of the hot water storage tank and the water supplied from the water supply source are mixed in the third mixing valve and supplied to the second hot water supply terminal. Therefore, the temperature of the hot water supplied to the second hot water supply terminal can be adjusted.

1 is a piping system diagram of a hot water supply device according to a first embodiment of the present invention. It is a block diagram of a hot water supply apparatus. It is a flowchart which shows the process sequence of a 1st mixing valve control part (control means). It is a flowchart which shows the process sequence at the time of a hot water supply driving | operation. It is a piping system diagram of the hot water supply apparatus according to the second embodiment of the present invention. It is a piping system diagram of the hot-water supply apparatus which concerns on 3rd Embodiment of this invention. (A) is a schematic diagram of the hot water supply apparatus of 1st Embodiment. (B)-(f) is the figure which showed the circuit formed between two different places of a hot water storage tank. (A) is a schematic diagram of the hot water supply apparatus of the modification 1 of 1st Embodiment. (B)-(f) is the figure which showed the circuit formed between two different places of a hot water storage tank. (A) is a schematic diagram of the hot water supply apparatus of the modification 2 of 1st Embodiment. (B)-(f) is the figure which showed the circuit formed between two different places of a hot water storage tank. (A) is a schematic diagram of the hot water supply apparatus of the modification 3 of 1st Embodiment. (B)-(f) is the figure which showed the circuit formed between two different places of a hot water storage tank. (A) is a schematic diagram of the hot water supply apparatus of the modification 4 of 1st Embodiment. (B)-(d) is the figure which showed the circuit formed between two different places of a hot water storage tank. (A) is a schematic diagram of the hot water supply apparatus of 2nd Embodiment. (B)-(f) is the figure which showed the circuit formed between two different places of a hot water storage tank.

  Hereinafter, a first embodiment of a hot water supply apparatus according to the present invention will be described.

<Configuration of hot water supply device>
As shown in FIG. 1, a hot water supply apparatus 1 according to the first embodiment supplies hot water to a currant (first hot water supply terminal) A, a shower (first hot water supply terminal) B, and a bath (second hot water supply terminal) C. The apparatus includes a heat pump unit (heating means) 2, a hot water storage unit 3 having a hot water storage tank 20, a remote controller 5 (see FIG. 2), and a control unit 4. In the following description, the currant A, the shower B, and the bath C are collectively referred to as a “hot water supply terminal”.

[Heat pump unit]
The heat pump unit 2 is for heating the hot water in the hot water storage tank 20. The heat pump unit 2 has a refrigerant circuit 10, which is connected to the compressor 11, the water heat exchanger 12, the electric expansion valve 13, and the air heat exchanger 14 in an annular shape. The refrigerant | coolant piping 15 to be provided is provided. The refrigerant circuit 10 also includes a gas heat exchanger 17 for exchanging heat between the high-temperature and high-pressure refrigerant that exits from the water heat exchanger 12 and the cold and low-pressure refrigerant that exits from the air heat exchanger 14. .

[Hot water storage unit]
The hot water storage unit 3 includes a hot water storage tank 20, a boiling circulation circuit 30, and a hot water supply / remedy circuit 40.

(Hot water storage tank)
An upper inflow portion 20 a, an upper outflow portion (first outflow portion) 20 b, and an upper outflow portion (third outflow portion) 20 c are provided at the upper portion of the hot water storage tank 20. An outflow portion (second outflow portion) 20 d is provided, and a lower outflow portion 20 e and lower inflow portions 20 f, 20 g, and 20 h are provided in the lower portion of the hot water storage tank 20.

  The upper inflow portion 20a, the lower outflow portion 20e, and the lower inflow portion 20f of the hot water storage tank 20 are connected to the boiling circulation circuit 30, and hot water taken out from the lower outflow portion 20e of the hot water storage tank 20 is transferred by the heat pump unit 2. After being heated, the hot water storage tank 20 is returned to the upper inflow portion 20a or the lower inflow portion 20f. Further, the upper outflow portions 20 b and 20 c, the intermediate outflow portion 20 d, and the lower inflow portions 20 g and 20 h of the hot water storage tank 20 are connected to the hot water supply / remedy circuit 40. When performing hot water supply to the hot water supply terminal or reheating the bath C, hot hot water flows out from the upper outflow portion 20b or the upper outflow portion 20c of the hot water storage tank 20, and the hot water storage tank 20 from the lower inflow portion 20g or the lower inflow portion 20h. Low-temperature water flows into the inside. Therefore, except for the case where all the hot water in the hot water storage tank 20 is heated by the heat pump unit 2 and becomes hot, the hot water in the hot water storage tank 20 has a high temperature in the upper part, a low temperature in the lower part, and an intermediate part in the middle. It is temperature.

  Six tank thermistors 21 a to 21 f are attached to the outer surface of the hot water storage tank 20 side by side in the vertical direction. The tank thermistors 21 a to 21 f are for detecting the temperature of hot water in the hot water storage tank 20. The tank thermistor 21d is attached at the same height as the position where the later-described intermediate outlet pipe 42 of the hot water storage tank 20 is connected. Further, the temperature detected by the tank thermistors 21a to 21f is used to detect how much hot water remains in the hot water storage tank 20 (detection of remaining hot water amount).

(Boiling circuit)
The boiling circulation circuit 30 is a circuit for taking out hot water in the lower part of the hot water storage tank 20, heating it in the hydrothermal exchanger 12 of the heat pump unit 2, and then returning it to the upper part in the hot water storage tank 20. The boiling circulation circuit 30 includes pipes 31 to 35, a boiling three-way valve 36, and a drainage three-way valve 38.

  The pipe 31 is a pipe that connects the lower outflow portion 20 e of the hot water storage tank 20 and the three-way valve 38 for drainage. In addition to the pipe 31, the drainage three-way valve 38 is connected to a pipe 32, which will be described later, provided with the water heat exchanger 12, and a pipe 35 toward the drain outlet D <b> 1. The drainage three-way valve 38 is normally switched to a state in which hot water (including water) flowing out from the lower outflow portion 20e of the hot water storage tank 20 flows toward the heat pump unit 2, and the hot water storage tank 20 and hot water supply. -When draining the piping in the memorial circuit 40, the water flowing out from the lower outflow portion 20e of the hot water storage tank 20 is switched to the state of flowing into the drain D1.

  The pipe 32 is a pipe that connects the drainage three-way valve 38 and the boiling three-way valve 36 via the water heat exchanger 12 described above. A boiling pump 37 is arranged in the middle of the pipe 32. The boiling pump 37 is for drawing hot water (including the case of water) in the hot water storage tank 20 into the pipe 32 via the lower outflow portion 20e, the pipe 31, and the drainage three-way valve 38. In addition, the incoming water thermistor 18 is disposed at a position upstream of the water heat exchanger 12 in the pipe 32, and the hot water thermistor 19 is disposed at a position downstream of the water heat exchanger 12 in the pipe 32. Yes.

  The pipe 33 is a pipe that connects the boiling three-way valve 36 and the upper inflow portion 20 a of the hot water storage tank 20. The pipe 34 is a pipe that connects the boiling three-way valve 36 and the lower inflow portion 20 f of the hot water storage tank 20. The The outlet side of the boiling three-way valve 36 is switched to either the pipe 33 or the pipe 34 by the control unit 4 according to the temperature detected by the incoming water thermistor 18.

(Hot water / memorial circuit)
The hot water supply / remembrance circuit 40 mixes the hot water in the hot water storage tank 20 and the water supplied from the water supply source S and supplies the mixed water to the hot water supply terminals (Kallang A, shower B, bath C). This is a circuit for retreating the bath C using hot water as a heat source. Further, the hot water supply / remembrance circuit 40 is configured to supply water into the hot water storage tank 20 at the same time when supplying hot water in the hot water storage tank 20 to the hot water supply terminal.

  The hot water supply / remembrance circuit 40 includes a water supply pipe 41, an intermediate outlet pipe 42, a connection pipe 43, an upper outlet pipe 44, a hot water supply pipe 45, a heat exchange circulation pipe 46, a connection pipe 47, and a hot water pipe. 48, a bath circulation pipe 49, a first mixing valve 51, a second mixing valve 52, and a third mixing valve 53.

  The water supply pipe 41 is a pipe that connects the water supply source S to the first mixing valve 51 and the third mixing valve 53. A check valve 65 is disposed in the vicinity of the first mixing valve 51 of the water supply pipe 41. The check valve 65 is configured such that water flows only in the direction from the water supply source toward the second mixing valve 52.

  A water supply branch pipe 41 a is connected to the water supply source S side of the branch point of the water supply pipe 41. The water supply branch pipe 41 a is a pipe for supplying water in the water supply pipe 41 to the lower inflow portion 20 g of the hot water storage tank 20. Further, a water temperature thermistor 63 and a check valve 64 are arranged in the water supply branch pipe 41a. The water temperature thermistor 63 is for detecting the temperature of the water supplied from the water supply source S.

  Further, a check valve 61 and a pressure reducing valve 62 are arranged in the order closer to the water supply source S on the side of the water supply source S than the position where the water supply branch pipe 41a of the water supply pipe 41 is connected. A branch pipe 41 b provided with a drain plug 66 is connected to a position between the check valve 61 and the pressure reducing valve 62 of the water supply pipe 41. The drain plug 66 is normally closed and is opened when draining water in the hot water storage tank 20 or the pipe. The branch pipe 41b is for discharging the water in the pipe to the drain D2 when draining water.

  The intermediate outlet pipe 42 is a pipe for supplying hot water flowing out from the intermediate outlet 20 d of the hot water storage tank 20 to the first mixing valve 51. The first mixing valve 51 is for mixing hot water flowing out from the intermediate outflow portion 20d of the hot water storage tank 20 with water supplied from the water supply source S.

  The connection pipe 43 is a pipe for supplying the hot water mixed by the first mixing valve 51 to the second mixing valve 52. An intermediate mixing thermistor 71 for detecting the temperature of the hot water mixed by the first mixing valve 51 is disposed in the connection pipe 43. In addition, a check valve 72 is disposed in the vicinity of the second mixing valve 52 of the connection pipe 43.

  The upper outlet pipe 44 is a pipe for supplying hot water flowing out from the upper outlet 20 b of the hot water storage tank 20 to the second mixing valve 52. A check valve 73 is disposed in the vicinity of the second mixing valve 52 in the upper outlet pipe 44. The second mixing valve 52 is for mixing the hot water flowing out from the upper outlet 20 b of the hot water storage tank 20 and the hot water mixed by the first mixing valve 51.

  The hot water supply pipe 45 is a pipe for supplying the hot water mixed by the second mixing valve 52 to the currant (first hot water supply terminal) A and the shower (first hot water supply terminal) B. A hot water supply flow sensor 74 and a hot water supply thermistor 75 are arranged in the middle of the hot water supply pipe 45. The hot water flow rate sensor 74 is for detecting the flow rate per unit time of hot water flowing through the hot water supply pipe 45. The hot water supply thermistor 75 is for detecting the temperature of hot water mixed by the second mixing valve 52 and supplied to the curan A and the shower B.

  The heat exchange circulation pipe 46 is a pipe for supplying hot water flowing out from the upper outflow portion 20 c of the hot water storage tank 20 to the lower outflow portion 20 e of the hot water storage tank 20. In the middle of the heat exchange circulation pipe 46, a memory heat exchanger 81 and a heat exchange circulation pump 82 are arranged. The heat exchange circulation pump 82 is for drawing hot hot water from the upper outflow portion 20 c of the hot water storage tank 20 into the heat exchange circulation pipe 46. The memorial heat exchanger 81 is for exchanging heat between hot hot water flowing through the heat exchange circulation pipe 46 and water flowing through a bath circulation pipe 49 described later.

  Further, a connection pipe 47 connected to the third mixing valve 53 is connected to the heat exchange circulation pipe 46 at a position closer to the upper outflow portion 20 c than the reheating heat exchanger 81. The third mixing valve 53 is for mixing hot water flowing out from the upper outflow portion 20 c of the hot water storage tank 20 and water supplied from the water supply source S.

  A parallel circuit in which a check valve 83 and a check valve 84 are connected in parallel is disposed at a position closer to the upper outflow portion 20c than a location where the connection pipe 47 of the heat exchange circulation pipe 46 is connected. Further, a bypass pipe 85 is connected to the heat exchange circulation pipe 46 so as to bypass this parallel circuit. In addition, a relief valve 86 is connected to the connection piping 47 side of the parallel circuit. The relief valve 86 has a role of exhausting the air in the hot water storage tank 20 and the piping to the outside at normal times. The relief valve 86 also has a role of supplying air into the pipe when performing the water draining operation in the hot water storage tank 20 and the pipe.

  Both ends of the bath circulation pipe 49 are connected to the bath (second hot water supply terminal) C. In the middle of the bath circulation piping 49, the above-mentioned regenerative heat exchanger 81, the bath circulation pump 96, the bath thermistor 97, the water level A sensor 98 is arranged. The bath thermistor 97 and the water level sensor 98 are arranged on the upstream side of the remedy heat exchanger 81 with respect to the flow direction of the hot water in the bath circulation pipe 49 when the bath circulation pump 96 is operated. The water level sensor 98 is for detecting the water level of the bath C.

  The hot water pipe 48 is a pipe that connects the third mixing valve 53 and a midway part of the bath circulation pipe 49 (specifically, a downstream portion of the additional heat exchanger 81). A hot water solenoid valve 91, a check valve 92, a hot water flow sensor 93, a check valve 94, and a hot water thermistor 95 are arranged in the hot water pipe 48. The hot water thermistor 95 is for detecting the temperature of hot water mixed by the third mixing valve 53 and supplied to the bath C. The hot water flow rate sensor 93 is for detecting the flow rate of hot water supplied to the bath C per unit time. The hot water solenoid valve 91 is switched to a valve open state when hot water is applied to the bath C.

[Remote controller]
The remote controller 5 is provided with an operation unit (not shown) and a display unit (not shown). The operation unit of the remote controller 5 includes a hot water supply temperature setting button for setting the hot water supply temperature in the currant A and the shower B, a bath temperature setting button for setting the hot water and reheating temperature of the bath C, a bath It has a hot water button for starting C hot water, a reheating button for starting reheating of the bath C, a menu button for changing various settings, and the like. On the display unit of the remote controller 5, a hot water supply set temperature, a bath set temperature, a remaining hot water amount in the hot water storage tank 20, and the like are displayed.

  The hot water supply temperature set by the hot water supply temperature setting button is set as the hot water supply set temperature. An upper limit and a lower limit (for example, 37 ° C.) are provided for the hot water set temperature that can be set by the hot water temperature setting button. The temperature set by the bath temperature setting button is set as the bath set temperature.

[Control unit]
The control unit 4 is composed of a microcomputer, a memory, and the like. As shown in FIG. 2, the control unit 4 includes a remote controller 5, thermistors 18, 19, 21 a to 21 f, 63, 71, 75, 97, 95, flow rate sensors 74, 93, a water level sensor 98, pumps 37, 82, 96. , The boiling three-way valve 36, the mixing valves 51 to 53, the hot water solenoid valve 91, the compressor 11 and the like are communicably connected by wire or wirelessly. In FIG. 2, some of the components connected to the control unit 4 are omitted. The control unit 4 controls a pump, a mixing valve, and the like based on a signal sent from the remote controller 5, the thermistor, a flow sensor, or the like. The control unit 4 includes a hot water supply determination unit 4a, a first mixing valve control unit 4b that controls the first mixing valve 51, a second mixing valve control unit 4c that controls the second mixing valve 52, and an intermediate mixing determination unit ( Determination means) 4d. In addition, the 1st mixing valve control part 4b and the 2nd mixing valve control part 4c are equivalent to the control means of this invention.

(Hot-water supply judgment part)
Based on the flow rate F1 detected by the hot water supply flow sensor 74, the hot water supply determination unit 4a determines whether hot water is supplied to either or both of the currant A and the shower B. Specifically, when the flow rate F1 detected by the hot water supply flow rate sensor 74 is equal to or higher than a predetermined minimum flow rate Q1, it is determined that hot water is being supplied, and the flow rate F1 is lower than the minimum flow rate Q1. Determines that no hot water is being supplied.

(Intermediate mixing judgment section)
The intermediate mixing determination unit 4d is based on the flow rate F1 supplied to the currant A or shower B detected by the hot water supply flow rate sensor 74 and the flow rate F2 supplied to the bath C detected by the hot water flow rate sensor 93. It is determined whether or not the hot water flowing out from the intermediate outlet 20d of the hot water storage tank 20 is allowed to pass through the first mixing valve 51. This determination is made only when hot water is supplied to Karan A or shower B. In the following description, judging that the hot water flowing out from the intermediate outflow part 20d is allowed to pass through the first mixing valve 51 may be judged as performing hot water removal, and judging not allowing passage through, It is said that it does not take hot water.

  As shown in the flowchart of FIG. 3, a specific determination method is performed when the hot water supply determination unit 4a determines that hot water is being supplied, that is, when the flow rate F1 ≧ the minimum flow rate Q1 (step S10). : Yes), when the flow rate F1 detected by the hot water supply flow rate sensor 74 is equal to or less than the predetermined flow rate Q2 (step S11: Yes), it is determined that hot water removal is not performed (step S14). The predetermined flow rate Q2 is larger than the minimum flow rate Q1. In addition, when the displacement amount ΔF2 per unit time of the flow rate F2 detected by the hot water flow rate sensor 93 is negative and the absolute value thereof is equal to or larger than the predetermined displacement amount ΔQ (step S12: Yes), the hot water is removed. It is determined not to be performed (step S14). Further, when both of the above two conditions are not satisfied (step S11: No, step S12: No), it is determined that the hot water removal is performed (step S13). The displacement amount ΔQ is set to a value smaller than the supply flow rate per unit time to the bath C during hot water operation. Further, the flow rate Q2 and the displacement amount ΔQ may be constant, but may be changed by operating the remote controller 5.

(Second mixing valve controller)
The 2nd mixing valve control part 4c controls the opening degree of the 2nd mixing valve 52 so that the temperature of the hot water mixed by the 2nd mixing valve 52 may turn into hot water supply preset temperature at the time of hot water supply to Karan A or shower B To do. Specifically, the feedforward control based on the temperature T3 detected by the intermediate mixing thermistor 71 and the temperature T4 detected by the tank thermistor 21a and the feedback control based on the temperature T5 detected by the hot water supply thermistor 75 The opening degree of the second mixing valve 52 is controlled so that the temperature of the hot water mixed by the two mixing valves 52 becomes the hot water supply set temperature.

  The second mixing valve control unit 4c starts the control of the second mixing valve 52 when the hot water supply to the curan A or the shower B is started and the hot water supply determination unit 4a determines that the hot water supply is being performed. To do.

  In addition, the second mixing valve control unit 4c controls the second mixing valve 52 when the hot water supply to the currant A and the shower B is finished and the hot water supply determination unit 4a determines that no hot water is being supplied. After the hot water supply is completed, after a predetermined time has elapsed, the opening degree of the second mixing valve 52 is initialized, the connection pipe 43 side is fully opened, and maintained until the next hot water supply. Thereby, when the next hot water supply is started, hot hot water from the hot water is prevented from being discharged from the currant A or the shower B.

  Further, the second mixing valve control unit 4c is configured such that the temperature T5 detected by the hot water supply thermistor 75 is a temperature within the hot water supply set temperature range (for example, the hot water supply set temperature ± 0.5 ° C.) close to the hot water supply set temperature (that is, When the temperature difference from the hot water supply set temperature is within a predetermined range), the temperature of the hot water mixed by the second mixing valve 52 is regarded as the hot water supply set temperature.

(First mixing valve controller)
The 1st mixing valve control part 4b controls the opening degree of the 1st mixing valve 51 so that the temperature of the warm water mixed with the 1st mixing valve 51 may turn into target temperature at the time of hot water supply to Karan A or shower B. Hereinafter, this control is referred to as target temperature control. However, if the intermediate mixing determination unit 4d determines that the hot water removal is not performed during hot water supply, the first mixing valve control unit 4b opens the first mixing valve 51 in the water supply source S side fully open state (water supply piping) 41 side full open state), while the hot water supply continues, this opening state is maintained. Therefore, after it is determined that hot water is not taken during hot water supply, even if it is determined that hot water is taken during hot water supply, the first mixing valve control unit 4b maintains the water supply source S side fully open state. .

  The first mixing valve control unit 4b performs the target temperature control by the second mixing valve 52 in the second mixing valve control unit 4c after the hot water supply is started and the control of the second mixing valve 52 is started. It starts after it is considered that the heated water has been set to hot water supply.

  Further, the first mixing valve control unit 4b ends the opening of the first mixing valve 51 when the hot water supply to the curan A and the shower B is finished and the hot water supply determination unit 4a determines that no hot water is being supplied. Is stopped at the opening at the end of hot water supply and maintained until the next hot water supply. Therefore, when the intermediate mixing determination unit 4d determines that the hot water removal is not performed, the first mixing valve 51 is maintained in the fully open state on the water supply source S side until the next hot water supply.

  Further, when performing the target temperature control, the first mixing valve control unit 4b performs feedforward control based on the temperature T1 detected by the water temperature thermistor 63 and the temperature T2 detected by the tank thermistor 21d, and the intermediate mixing thermistor 71. The opening degree of the first mixing valve 51 is controlled so that the temperature of the hot water mixed by the first mixing valve 51 becomes the target temperature by the feedback control based on the temperature T3 detected by the above.

  Further, the first mixing valve control unit 4b determines that the temperature T3 detected by the intermediate mixing thermistor 71 is a temperature within a target temperature range (for example, target temperature ± 2 ° C.) near the target temperature (that is, the target temperature and The temperature of the hot water mixed by the first mixing valve 51 is regarded as the target temperature.

  The target temperature is a constant temperature (eg, 31 ° C.) regardless of the hot water supply set temperature. As described above, a lower limit (for example, 37 ° C.) is provided for the hot water supply set temperature that can be set by the remote controller 5, and the target temperature is set in advance to a temperature lower than the lowest hot water set temperature that can be set. Yes. Accordingly, hot water flowing out from the upper outlet 20b of the hot water storage tank 20 is always used for hot water supply to the caran A or the shower B.

<Operation of water heater>
Next, the operation of the hot water supply apparatus 1 will be described.
The operation of the hot water supply apparatus 1 includes a boiling operation for heating hot water stored in the hot water storage tank 20, a hot water supply operation for supplying hot water to the Karan A or the shower B, and hot water for supplying hot water to the bath C (hot water). There are a beam operation and a memorial operation for retreating the bath C. These can be performed simultaneously.

[Boiling operation]
The boiling operation is automatically started in the late night hours when the electricity bill is cheap. Further, even during the daytime period, when the amount of remaining hot water in the hot water storage tank 20 becomes less than a predetermined value, the boiling operation is started. When the boiling operation start condition based on the time or the amount of remaining hot water is satisfied, the control unit 4 drives the compressor 11 and the boiling pump 37. Then, the hot water in the hot water storage tank 20 flows out from the lower outflow portion 20 e into the pipe 31 and flows into the pipe 32 through the drainage three-way valve 38. This hot water is heated by exchanging heat with the refrigerant in the water heat exchanger 12. When the temperature of the hot water heated by the water heat exchanger 12 is sufficiently high (when the temperature detected by the incoming thermistor 18 is equal to or higher than a predetermined temperature), the control unit 4 connects the outlet side of the boiling three-way valve 36 to the piping. The hot water flows into the hot water storage tank 20 from the upper inflow portion 20a. By continuously performing this operation, hot hot water is stored in the hot water storage tank 20. On the other hand, when the temperature of the hot water heat-exchanged by the water heat exchanger 12 is not sufficiently high, such as immediately after the drive of the compressor 11 is started (when the temperature detected by the incoming water thermistor 18 is less than a predetermined temperature). The outlet side of the boiling three-way valve 36 is switched to the pipe 34, and this hot water flows into the hot water storage tank 20 from the lower inflow portion 20f.

[Memorial operation]
The chasing operation is started when the chasing button of the remote controller 5 is pressed. The control unit 4 that has received the memory start signal from the remote controller 5 drives the heat exchange circulation pump 82 and the bath circulation pump 96. Then, the hot water flowing out from the bath C to the bath circulation pipe 49 and the hot water flowing out from the upper outflow portion 20 c of the hot water storage tank 20 to the heat exchange circulation pipe 46 are heat-exchanged by the memory heat exchanger 81. The hot water flowing through the bath circulation pipe 49 is heated by heat exchange and flows into the bath C. The hot water flowing through the heat exchange circulation pipe 46 flows into the hot water storage tank 20 from the lower inflow portion 20h after the temperature is lowered by heat exchange. Thereafter, when the temperature detected by the bath thermistor 97 becomes the bath set temperature set by the remote controller 5, the memorial operation ends.

[Hot water driving]
The hot water operation is started when the hot water button on the remote controller 5 is pressed. Upon receiving the hot water start signal from the remote controller 5, the control unit 4 switches the hot water electromagnetic valve 91 to the open state. Then, water flows into the hot water storage tank 20 from the lower inflow portion 20g due to the water supply pressure of the water supply source S, and at the same time, hot hot water flows out from the upper outflow portion 20c of the hot water storage tank 20 to the heat exchange circulation pipe 46 and the connection pipe 47. . This hot water is mixed with the water supplied from the water supply source S in the third mixing valve 53 and then supplied to the bath C via the hot water pipe 48 and the bath circulation pipe 49. At this time, the opening degree of the third mixing valve 53 is controlled by the control unit 4 so that the hot water mixed by the third mixing valve 53 becomes the bath set temperature set by the remote controller 5. Thereafter, when the total amount of water supplied to the bath C calculated based on the detection result of the hot water flow rate sensor 93 reaches a predetermined value, the hot water operation is ended.

[Hot water operation]
The hot water supply operation is started or ended by operating the levers of the currant A and the shower B or the like. Hereinafter, the flow of water during the hot water supply operation will be described.

  When the levers of the curan A and the shower B are switched to the flowing water state, water flows into the hot water storage tank 20 from the lower inflow portion 20g due to the water supply pressure of the water supply source S, and the upper outflow portion 20b and the intermediate outflow portion of the hot water storage tank 20 Hot water flows out from 20d. The warm water flowing out from the intermediate outlet 20d to the intermediate outlet pipe 42 is mixed with the water supplied from the water supply source S in the first mixing valve 51, and then in the second mixing valve 52, the upper outlet of the hot water storage tank 20. It is mixed with hot hot water that has flowed from 20 b to the upper outlet pipe 44 and supplied to Karan A or Shower B.

  In addition, when the 1st mixing valve 51 is in the water supply source S side full open state, the water supplied from the water supply source S and the hot hot water which flowed out from the upper part of the hot water storage tank 20 are the 2nd mixing valve. At 52, they are mixed and supplied to Karan A or Shower B. In addition, when the first mixing valve 51 is in the fully opened state on the intermediate outlet pipe 42 side, the hot water flowing out from the intermediate portion of the hot water storage tank 20 to the intermediate outlet pipe 42 and the hot water flowing out from the upper portion of the hot water storage tank 20 Hot water is mixed in the second mixing valve 52 and supplied to the curan A or the shower B.

  Next, operation | movement of the control part 4 at the time of hot-water supply driving | operation is demonstrated using the flowchart of FIG.

  When the hot water supply is started by switching the lever of the currant A or the shower B to the flowing water state and the hot water supply determination unit 4a determines that the hot water supply is being performed, the second mixing valve control unit 4c Control of the mixing valve 52 is started (step S1). Specifically, the mixing ratio of the second mixing valve 52 is adjusted so that the temperature of the hot water mixed by the second mixing valve 52 becomes the hot water supply set temperature set by the remote controller 5.

  By controlling the opening degree of the second mixing valve 52 by the second mixing valve control unit 4c, the temperature T5 detected by the hot water supply thermistor 75 approaches the hot water supply set temperature. The temperature T5 detected by the hot water supply thermistor 75 becomes a temperature within the hot water supply set temperature range (step S2: Yes), and the temperature of the hot water mixed by the second mixing valve 52 in the second mixing valve control unit 4c. Is regarded as having reached the hot water supply set temperature, the first mixing valve control unit 4b starts target temperature control of the first mixing valve 51 (step S3). Specifically, the mixing ratio of the first mixing valve 51 is adjusted so that the temperature of the hot water mixed by the first mixing valve 51 becomes the target temperature.

  When the mixing ratio of the first mixing valve 51 is adjusted and the temperature T2, which is the temperature of the hot water mixed by the first mixing valve 51, changes, the mixing ratio of the second mixing valve 52 is also adjusted accordingly. When the temperature T2 reaches a temperature within the target temperature range, the opening degree of the first mixing valve 51 is maintained and the temperature T2 is stabilized. Thereafter, the opening degree of the second mixing valve 52 adjusted based on the temperature T2 is also stabilized, and the temperature T5 that is the temperature of the hot water mixed by the second mixing valve 52 is also stabilized.

  When the hot water supply is terminated in the hot water supply determination unit 4a, the first mixing valve control unit 4b and the second mixing valve are switched. The control unit 4c stops the control of the first mixing valve 51 and the second mixing valve 52, respectively. In the first mixing valve 51, the opening at the end of hot water supply is maintained until the next hot water supply. The second mixing valve 52 is initialized (switched to the connection pipe 43 side fully open state) after a predetermined time has elapsed from the end of hot water supply, and the opening thereof is maintained until the next hot water supply time.

  The flow rate detected by the hot water supply flow sensor 74 when the hot water flow rate to the currant A or the shower B is set to be considerably small by a lever or the like at the start of hot water supply to the currant A or the shower B or during hot water supply. F1 may be a predetermined flow rate Q2 or less. In addition, when one hot water supply is terminated from a state where hot water is being supplied in both the currant A and the shower B, the flow rate F1 detected by the hot water supply flow rate sensor 74 may become a predetermined flow rate Q2 or less. In such a case, the intermediate mixing determination unit 4d determines that the hot water removal is not performed, and the first mixing valve 51 is switched to the water supply source S side fully opened state by the first mixing valve control unit 4b. The opening state is maintained during hot water supply.

When the hot water operation is terminated or stopped during hot water supply, the displacement amount ΔF2 per unit time of the flow rate F2 detected by the hot water flow rate sensor 93 is negative and the absolute value thereof is equal to or greater than the displacement amount ΔQ. In addition, when the hot water operation is performed simultaneously with the hot water supply, the hot water flow rate sensor for the bath C is reduced by operating the remote controller 5 during the hot water supply, thereby reducing the hot water flow rate sensor per unit time. The displacement amount ΔF2 per unit time of the flow rate F2 detected by 93 may be negative and the absolute value thereof may be greater than the displacement amount ΔQ.
In such a case, the intermediate mixing determination unit 4d determines that the hot water removal is not performed, and the first mixing valve 51 is switched to the water supply source S side fully opened state by the first mixing valve control unit 4b. The opening state is maintained during hot water supply.

<Characteristics of the hot water supply apparatus of the first embodiment>
The hot water supply apparatus 1 of the present embodiment has the following characteristics.

  When the hot water supply flow rate F1 to the currant A and the shower B decreases, the flow rate of water flowing from the water supply source S toward the check valve 65 and the first mixing valve 51 also becomes considerably small. Since the check valve 65 is configured to open according to the pressure of the inflowing water, if the flow rate of the inflowing water is extremely small, the check valve 65 cannot be completely opened. The flow rate of water passing through the check valve 65 may be further reduced. In this case, if the first mixing valve 51 is mixed with warm water that has flowed out from the intermediate outlet 20d and water supplied from the water supply source S in the first mixing valve 51, The mixing ratio varies so that the ratio of the water supplied from the water supply source S decreases, and the temperature T3 of the hot water mixed by the first mixing valve 51 increases.

  In the hot water supply device 1 of the first embodiment, when the flow rate F1 that is the hot water supply flow rate to the currant A or the shower B is reduced to a predetermined flow rate Q2 or less, the first mixing valve 51 is switched to the water supply source S side fully open state. Therefore, even if the flow rate F1 decreases so that the check valve 65 cannot be completely opened, the temperature T3 of the hot water that has passed through the first mixing valve 51 can be suppressed from increasing. Therefore, an increase in the temperature T5 of the hot water supplied to the currant A or the shower B can be suppressed.

  In addition, when the hot water supply flow rate F1 to the currant A and the shower B is considerably small, it is difficult to accurately perform the target temperature control of the first mixing valve 51. Therefore, when the target temperature control of the first mixing valve 51 is performed, The temperature of the hot water mixed by the first mixing valve 51 varies, and the temperature of the hot water supplied to the currant A or the shower B varies.

  In the hot water supply apparatus 1 according to the first embodiment, when the flow rate F1 is equal to or less than the predetermined flow rate Q2, the first mixing valve 51 is switched to the fully-opened state on the water supply source S side, so that the target temperature control of the first mixing valve 51 is accurately performed. Even if the flow rate F1 is small enough to be difficult to perform, fluctuations in the temperature T3 of the hot water that has passed through the first mixing valve 51 can be suppressed. Therefore, the fluctuation | variation of the temperature T5 of the warm water supplied to Karan A or the shower B can be suppressed.

  Further, when the hot water operation is terminated or stopped during the hot water supply to Karan A or the shower B and the hot water supply flow rate F2 to the bath C is reduced, the flow rate of the hot water flowing out from the upper outflow portion 20c is reduced. The flow rate of hot water flowing out from the intermediate outflow portion 20d and the upper outflow portion 20b increases. In this case, if the first mixing valve 51 is mixed with warm water that has flowed out from the intermediate outlet 20d and water supplied from the water supply source S in the first mixing valve 51, The mixing ratio varies so that the ratio of warm water flowing out from the intermediate outlet 20d increases, and the temperature T3 of warm water mixed by the first mixing valve 51 increases.

  In the hot water supply apparatus 1 of the first embodiment, during the hot water supply to the curan A or the shower B, when the displacement amount ΔF2 per unit time of the flow rate F2 is negative and the absolute value thereof is equal to or larger than the predetermined displacement amount ΔQ, Since the 1st mixing valve 51 is switched to the water supply source S side full open state, it can control that temperature T3 of warm water which passed the 1st mixing valve 51 rises. Therefore, an increase in the temperature T5 of the hot water supplied to the currant A or the shower B can be suppressed.

Further, as described above, when the hot water is supplied to the currant A or the shower B, it is determined that the intermediate mixing determination unit 4d does not perform hot water removal, and the first mixing valve control unit 4b causes the first mixing valve 51 to supply water. After switching to the S-side fully open state, during the warm water supply, even if it is determined that the intermediate mixing determination unit 4d performs hot water removal, while the warm water supply is continued, the first mixing valve 51 is opened. Keep the degree.
As described above, even when the determination by the intermediate mixing determination unit 4d changes during hot water supply, the opening degree of the first mixing valve 51 is changed during hot water supply by maintaining the opening degree of the first mixing valve 51. Can be prevented from occurring.

  Next, a second embodiment of the hot water supply apparatus according to the present invention will be described. The same elements as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the hot water supply device 1001 of the second embodiment is different from the hot water supply device 1 of the first embodiment in the following points. The hot water supply device 1001 is configured to mix the hot water mixed by the first mixing valve 51 and the hot water flowing out from the upper outlet 20c of the hot water storage tank 20 with the third mixing valve 153 and supply the hot water to the bath C. ing. This hot water supply apparatus 1001 has the same effect as that of the hot water supply apparatus 1 described in the first embodiment.

  Next, a third embodiment of the hot water supply apparatus according to the present invention will be described. The same elements as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the hot water supply apparatus 2001 of the third embodiment is different from the hot water supply apparatus 1 of the first embodiment in the following points. The hot water supply apparatus 2001 mixes the hot water flowing out from the upper outflow portion 20b of the hot water storage tank 20 and the hot water flowing out from the intermediate outflow portion 20d by the first mixing valve 251, and is then supplied from the mixed hot water and the water supply source S. The water is mixed in the second mixing valve 252 and supplied to the curan A or the shower B. In addition, the intermediate mixing determination unit (determination unit) of the hot water supply apparatus 2001 includes the intermediate outflow unit 20d only when the flow rate F1 of hot water supplied to the currant A and the shower B detected by the hot water supply flow rate sensor 74 is equal to or less than a predetermined flow rate. It is determined that the hot water flowing out from the first mixing valve 251 is not allowed to pass (no hot water is removed).

  In the hot water supply apparatus 2001 of the third embodiment, when the flow rate F1 of hot water supplied to the currant A and the shower B is less than or equal to a predetermined flow rate, the first mixing valve 251 is switched to the fully open state on the water supply source S side. Even if the flow rate F1 is so small that it is difficult to perform the target temperature control of the mixing valve 251 with high accuracy, fluctuations in the temperature of the hot water that has passed through the first mixing valve 251 can be suppressed. Therefore, the fluctuation | variation of the temperature of the hot water supplied to Karan A or the shower B can be suppressed.

  Although the first to third embodiments of the present invention have been described above, it should be considered that the specific configuration of the present invention is not limited to the first to third embodiments. The scope of the present invention is shown not only by the description of the first to third embodiments but also by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, in the first and second embodiments, the intermediate mixing determination unit 4d determines whether or not to remove hot water based on the flow rate F1 detected by the hot water supply flow rate sensor 74, and detects by the hot water flow rate sensor 93. However, the present invention is not limited to this, and it is determined whether or not to perform hot water removal only based on the flow rate F1. May be. Conversely, based on only the flow rate F2 detected by the hot water flow rate sensor 93, it may be determined whether or not to perform hot water removal.

  Moreover, in the said 1st-3rd embodiment, when it is judged that the intermediate mixing judgment part 4d does not perform hot water removal, the 1st mixing valve control part 4b makes the 1st mixing valve 51 the water supply source S side full open state However, the present invention is not limited to this. For example, the opening degree of the first mixing valve 51 may be switched so that the passing amount of the hot water flowing out from the intermediate outflow portion 20d through the first mixing valve 51 decreases. In this case, as in the first to third embodiments, the temperature of the hot water supplied to the currant A and the shower B varies as compared with the case where the first mixing valve 51 is switched to the water supply source S side fully open state. Can be more reliably suppressed. In this respect, the first to third embodiments are more preferable.

  By the way, in the hot water supply apparatus of the first embodiment, the hot water stored in the upper part of the hot water storage tank 20 or the differential pressure due to the specific gravity difference between the hot water stored in the upper part of the hot water storage tank 20 and the hot water stored in the intermediate part. And the intermediate pressure from the upper outlets 20b and 20c of the hot water storage tank 20 inside the pipe in the hot water supply / remembrance circuit 40, due to the differential pressure caused by the difference in specific gravity due to the temperature difference with the hot water stored in the lower part. Convection may occur in the direction toward the outflow portion 20d or the lower inflow portion 20g. Therefore, hereinafter, the function of each check valve provided to prevent this convection will be described with reference to FIG.

  Fig.7 (a) is a schematic diagram of the hot water supply apparatus 1 of 1st Embodiment shown in FIG. FIG. 7B to FIG. 7F are diagrams showing circuits formed between two places of the hot water storage tank 20 having different heights.

[First to fifth circuits]
Of the hot water supply / remembrance circuit 40 of the hot water storage unit 3 shown in FIG. 7A, the circuits shown in bold lines in FIGS. 7B to 7F are the first circuit to the fifth circuit, respectively. . In addition, the branch point B1 in the figure is a connection point that connects the lower inflow portion 20g of the hot water storage tank 20 and the water supply source S, and the branch point B2 is a connection point that connects the branch point B1 and the first mixing valve 51. The branch point B3 indicates a connection point that connects the branch point B2 with the upper outlet 20c of the hot water storage tank 20 and the relief valve 86.

[First circuit]
The first circuit shown in FIG. 7B is from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d of the hot water storage tank 20 via the second mixing valve 52 and the first mixing valve 51. Circuit. In the first circuit, a check valve 73 is provided between the upper outlet 20b of the hot water storage tank 20 and the second mixing valve 52 so that hot water flows only in the direction from the upper outlet 20b to the second mixing valve 52. ing. The check valve 73 is a spring-type check valve and is configured to open by a pressure equal to or higher than the differential pressure P. Here, the differential pressure P is set so as not to open with a differential pressure caused by convection from the upper outflow portion 20b to the intermediate outflow portion 20d. Accordingly, in the first circuit, the check valve 73 is arranged, thereby preventing convection in the direction from the upper outlet 20b of the hot water storage tank 20 toward the intermediate outlet 20d.

  The check valve 72 disposed between the first mixing valve 51 and the second mixing valve 52 is a flow of hot water only in the direction from the first mixing valve 51 to the second mixing valve 52, It is also used to prevent convection from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d and the lower inlet 20g.

  The “differential pressure due to convection” is stored in the portion corresponding to the two places where the hot water storage tank 20 is different in the circuit formed between the two places where the height of the hot water storage tank 20 is different. It means the pressure difference generated by the specific gravity difference due to the temperature difference of hot water. The “differential pressure due to convection” increases as the difference in height increases, and increases as the difference in specific gravity of hot water increases. As described above, the check valve 73 is configured to open by a pressure equal to or higher than the differential pressure P, and this differential pressure P is caused by convection from the upper outflow portion 20b to the intermediate outflow portion 20d. It is set not to open the valve at the differential pressure. Accordingly, since the difference in height between the upper outflow portion 20b and the intermediate outflow portion 20d is constant, the differential pressure P is different from the warm water stored near the upper outflow portion and the hot water stored near the intermediate outflow portion. It is set to be larger than the differential pressure when the specific gravity difference is maximum.

  In addition, when a circuit is formed between the upper outflow portion provided on the upper surface of the hot water storage tank 20 and the lower inflow portion provided on the lower surface (the difference in height is maximum), the circuit is close to the upper outflow portion. When the specific gravity difference between the hot water stored in the water and the water stored near the lower inflow portion is maximized, the “differential pressure due to convection” is considered to be the largest. Therefore, in the hot water supply apparatus of the first embodiment, the differential pressure P of the check valve that prevents convection is prevented from opening due to the differential pressure even when the “differential pressure due to convection” becomes the largest. Is set. In the first embodiment, since the specific gravity difference (density difference) of the hot water in the hot water storage tank 20 is 3.6% at maximum in the range of 0 to 90 ° C., the height of the hot water storage tank 20 is set to about 2 m and the check is not performed. The valve differential pressure P is set to 0.72 kPa.

[Second circuit]
The second circuit shown in FIG. 7C is configured so that the hot water storage tank 20 is connected to the hot water tank 20 from the upper outlet 20c of the hot water storage tank 20 through the branch point B3, the hot water mixing valve 53, the branch point B2, and the first mixing valve 51. This is a circuit up to the intermediate outflow portion 20d. In the second circuit, a check is made such that hot water flows between the upper outlet 20c of the hot water storage tank 20 and the branch point B3 only in the direction from the upper outlet 20c to the hot water mixing valve 53 via the branch point B3. A valve 83 is arranged. The check valve 83 is configured not to open with a differential pressure caused by convection from the upper outlet 20c to the intermediate outlet 20d and the lower inlet 20g. Therefore, in the second circuit, the check valve 83 is arranged to prevent convection in the direction from the upper outlet 20c of the hot water storage tank 20 toward the intermediate outlet 20d. The check valve 84 connected in parallel to the check valve 83 flows hot water only in the direction from the branch point B3 toward the upper outflow portion 20c, and is used for draining work described later. It is also used to prevent convection from the upper outlet 20c of the hot water storage tank 20 to the intermediate outlet 20d and the lower inlet 20g.

[Third circuit]
The third circuit shown in FIG. 7 (d) is the lower inflow of the hot water storage tank 20 from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the hot water mixing valve 53, the branch point B2 and the branch point B1. This is a circuit up to the part 20g. In the third circuit, the above-described check valve 83 is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3. Therefore, in the third circuit, convection in the direction from the upper outlet 20c of the hot water storage tank 20 toward the lower inlet 20g is prevented.

[Fourth circuit]
The fourth circuit shown in FIG. 7 (e) is configured such that the hot water storage tank 20 has an upper outlet 20b through the second mixing valve 52, the first mixing valve 51, the branch point B2, and the branch point B1. This is a circuit up to the lower inflow portion 20g. In the fourth circuit, the above-described check valve 73 is disposed between the upper outlet 20 b of the hot water storage tank 20 and the second mixing valve 52. Therefore, in the fourth circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the lower inlet 20g is prevented.

[Fifth circuit]
The fifth circuit shown in FIG. 7F reaches the lower inflow portion 20g of the hot water storage tank 20 from the intermediate outflow portion 20d of the hot water storage tank 20 via the first mixing valve 51, the branch point B2, and the branch point B1. It is a circuit up to. In the fifth circuit, a check valve 65 is provided between the first mixing valve 51 and the branch point B2 so that hot water flows only in the direction from the water supply source S to the first mixing valve 51 via the branch point B2. Has been. Thereby, warm water does not flow in the direction from the first mixing valve 51 toward the branch point B2. Therefore, in the fifth circuit, convection in the direction from the intermediate outflow portion 20d of the hot water storage tank 20 toward the lower inflow portion 20g is prevented.

[Draining work]
Next, the water draining operation at the time of maintenance of the hot water storage unit 3 will be described. In the hot water storage unit 3, when water is drained from the hot water storage tank 20 or the piping in the hot water supply / remembrance circuit 40, the drainage three-way valve 38 allows the hot water in the hot water storage tank 20 to be drained from the drain outlet D 1. At the same time, the pressure reducing valve 62 and the drain plug 66 are opened. As a result, air is sucked into the hot water storage tank 20 and the pipe from the relief valve 86, and water in the hot water storage tank 20 and the pipe is drained from the drains D1 and D2, so that water is supplied from the hot water storage tank 20 and the pipe. Unplugging is performed.

  More specifically, for example, the drainage path f1 (from the relief valve 86, the branch point B3, the hot water mixing valve 53, the branch point B2, the branch point B1, the pressure reducing valve 62, and the drain plug 66) Drainage path f2 (from the relief valve 86, through the branch point B3, the check valve 84, the upper outlet 20c of the hot water tank 20, the lower outlet 20e, and the drainage three-way valve 38). Path in the direction toward the mouth D1), drainage path f3 (from the relief valve 86, branch point B3, hot water mixing valve 53, branch point B2, check valve 65, first mixing valve 51, intermediate outlet 20d, lower part The water is drained from the hot water storage tank 20 and the piping by flowing the water through the outflow portion 20e and the drainage three-way valve 38 in the direction toward the drain outlet D1. Here, since each of the drainage channels f1 to f3 is not provided with a check valve through which hot water flows only in the direction from the drainage port D1 or the drainage port D2 to the relief valve 86, the drainage port D1 or the drainage port. Water can flow toward D2.

  As described above, in the hot water supply device 1, convection can be prevented in the first circuit to the fifth circuit formed between two places of the hot water storage tank 20 having different heights. Moreover, the water inside the hot water storage tank 20 and the hot water supply / remembrance circuit 40 can be drained from the drains D1 and D2.

<Modification 1>
Fig.8 (a) is a schematic diagram of the hot water supply apparatus 101 of the modification 1 of 1st Embodiment. In Modification 1, the same elements as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown to Fig.8 (a), the hot water supply apparatus 101 of the modification 1 is different from the hot water supply apparatus 1 which concerns on the said 1st Embodiment by the following points. That is, the hot water supply apparatus 101 according to the first modified example is different from the upper outflow portion 20b of the hot water storage tank 20 in that the check valve 84 is not disposed between the upper outflow portion 20c of the hot water storage tank 20 and the branch point B3. The check valve 73 is not disposed between the mixing valves 52, and the check valve 64 is not disposed between the branch point B1 and the lower inflow portion 20g of the hot water storage tank 20. It differs from the hot water supply apparatus 1 which concerns on.

  FIG. 8B to FIG. 8F are diagrams showing circuits formed between two different locations of the hot water storage tank 20.

[First Circuit 1 to Fifth Circuit 5]
Among the hot water supply / remembrance circuits of the hot water supply apparatus 101 shown in FIG. 8 (a), the circuits indicated by bold lines in FIGS. 8 (b) to 8 (f) are the first circuit 1 to the fifth circuit 5, respectively. To do.

[First circuit 1]
The first circuit 1 shown in FIG. 8B extends from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d of the hot water storage tank 20 via the second mixing valve 52 and the first mixing valve 51. Circuit. In the first circuit 1, a check valve 72 through which hot water flows only in the direction from the first mixing valve 51 to the second mixing valve 52 is disposed between the second mixing valve 52 and the first mixing valve 51. Yes. Thereby, warm water does not flow in the direction from the second mixing valve 52 toward the first mixing valve 51. Therefore, in the first circuit 1, convection in the direction from the upper outlet 20b of the hot water storage tank 20 toward the intermediate outlet 20d is prevented.

[Second circuit 2]
The second circuit 2 shown in FIG. 8C is configured so that the hot water storage tank 20 passes from the upper outlet 20c of the hot water storage tank 20 through the branch point B3, the hot water mixing valve 53, the branch point B2, and the first mixing valve 51. This is a circuit up to the intermediate outflow portion 20d. In the second circuit 2, the check valve 83 described above is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3. Accordingly, in the second circuit 2, convection in the direction from the upper outlet 20c of the hot water storage tank 20 toward the intermediate outlet 20d is prevented.

[Third circuit 3]
The third circuit 3 shown in FIG. 8 (d) has a lower part of the hot water storage tank 20 from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the hot water mixing valve 53, the branch point B2 and the branch point B1. This is a circuit up to the inflow portion 20g. In the third circuit 3, the check valve 83 described above is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3. Accordingly, in the third circuit 3, convection in the direction from the upper outlet 20c of the hot water storage tank 20 to the lower inlet 20g is prevented.

[Fourth circuit 4]
The fourth circuit 4 shown in FIG. 8 (e) is connected to the hot water storage tank 20 from the upper outlet 20b of the hot water storage tank 20 via the second mixing valve 52, the first mixing valve 51, the branch point B2, and the branch point B1. This is a circuit up to the lower inflow portion 20g. In the fourth circuit 4, the check valve 72 described above is disposed between the second mixing valve 52 and the first mixing valve 51. Therefore, in the 4th circuit 4, the convection of the direction which goes to the lower inflow part 20g from the upper outflow part 20b of the hot water storage tank 20 is prevented.

[Fifth circuit 5]
The fifth circuit 5 shown in FIG. 8 (f) passes from the intermediate outflow portion 20d of the hot water storage tank 20 to the lower inflow portion 20g of the hot water storage tank 20 via the first mixing valve 51, the branch point B2, and the branch point B1. It is a circuit up to. In the fifth circuit 5, the check valve 65 described above is disposed between the first mixing valve 51 and the branch point B3. Accordingly, in the fifth circuit 5, convection in the direction from the intermediate outflow portion 20d of the hot water storage tank 20 toward the lower inflow portion 20g is prevented.

[Draining work]
Next, the water draining operation at the time of maintenance of the hot water supply apparatus 101 will be described. In the hot water supply apparatus 101, when water is drained from the inside of the hot water storage tank 20 or the piping in the hot water supply / remembrance circuit 40, the drainage three-way valve 38 drains the hot water in the hot water storage tank 20 from the drain D1. In addition, the pressure reducing valve 62 and the drain plug 66 are opened. As a result, air is sucked into the hot water storage tank 20 and the pipe from the relief valve 86, and water in the hot water storage tank 20 and the pipe is drained from the drains D1 and D2, so that water is supplied from the hot water storage tank 20 and the pipe. Unplugging is performed.

  More specifically, for example, the drainage path f11 (from the relief valve 86, the branch point B3, the hot water mixing valve 53, the branch point B2, the branch point B1, the pressure reducing valve 62, and the drain plug 66) Or a drainage path f12 (from the relief valve 86, branch point B3, hot water mixing valve 53, branch point B2, check valve 65, first mixing valve 51, intermediate outlet 20d of the hot water storage tank 20) When the water flows through the lower outlet 20e and the drainage three-way valve 38 in the direction toward the drain outlet D1, the hot water tank 20 and the pipe are drained. Here, since each of the drainage paths f11 and f12 is not provided with a check valve through which hot water flows only in the direction from the drainage ports D1 and D2 toward the relief valve 86, the drainage channels D1 and D2 are directed toward the drainage ports D1 and D2. Water can flow.

  As described above, in the hot water supply apparatus 101, convection can be prevented in the first circuit 1 to the fifth circuit 5 formed between two different locations of the hot water storage tank 20. Moreover, the water inside the hot water storage tank 20 and the hot water supply / remembrance circuit 40 can be drained from the drains D1 and D2.

<Modification 2>
Fig.9 (a) is a schematic diagram of the hot water supply apparatus 201 of the modification 2 of the said 1st Embodiment. In Modification 2, the same elements as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown to Fig.9 (a), the hot water supply apparatus 201 of the modification 2 differs from the hot water supply apparatus 1 which concerns on the said 1st Embodiment by the following points. That is, in the hot water supply apparatus 201 of the second modification, the check valve 84 is not disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3, and between the branch point B3 and the hot water mixing valve 53. The check valve 83 is disposed at the same point, the check valve 73 is not disposed between the upper outlet 20b of the hot water storage tank 20 and the second mixing valve 52, the branch point B1 and the lower inflow of the hot water storage tank 20 It differs from the hot water storage unit 3 in that the check valve 64 is not disposed between the portion 20g.

  FIG. 9B to FIG. 9F are diagrams showing circuits formed between two different locations of the hot water storage tank 20.

[First to fifth circuits]
Among the hot water supply / remembrance circuits of the hot water supply apparatus 201 shown in FIG. 9A, the circuits indicated by bold lines in FIGS. 9B to 9F are referred to as a first circuit to a fifth circuit, respectively.

[First circuit]
The first circuit shown in FIG. 9B is from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d of the hot water storage tank 20 via the second mixing valve 52 and the first mixing valve 51. Circuit. In the first circuit, the check valve 72 described above is disposed between the second mixing valve 52 and the first mixing valve 51. Thereby, warm water does not flow in the direction from the second mixing valve 52 toward the first mixing valve 51. Therefore, in the first circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d is prevented.

[First circuit]
The second circuit shown in FIG. 9C is from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the check valve 83, the hot water mixing valve 53, the branch point B2, and the first mixing valve 51. This is a circuit up to the intermediate outlet 20d of the hot water storage tank 20. In the second circuit, the above-described check valve 83 is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3. Therefore, in the second circuit, convection in the direction from the upper outlet 20c of the hot water storage tank 20 toward the intermediate outlet 20d is prevented.

[Third circuit]
The third circuit shown in FIG. 9 (d) is the lower inflow of the hot water storage tank 20 from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the hot water mixing valve 53, the branch point B2 and the branch point B1. This is a circuit up to the part 20g. In the third circuit, the above-described check valve 83 is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B2. Accordingly, in the third circuit, convection in the direction from the upper outflow portion 20c toward the lower inflow portion 20g is prevented.

[Fourth circuit]
The fourth circuit shown in FIG. 9 (e) is configured to supply the hot water storage tank 20 from the upper outlet 20b of the hot water storage tank 20 via the second mixing valve 52, the first mixing valve 51, the branch point B2, and the branch point B1. This is a circuit up to the lower inflow portion 20g. In the fourth circuit, the above-described check valve 72 is disposed between the second mixing valve 52 and the first mixing valve 51. Therefore, in the fourth circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the lower inlet 20g is prevented.

[Fifth circuit]
The fifth circuit shown in FIG. 9 (f) reaches from the intermediate outflow portion 20d of the hot water storage tank 20 to the lower inflow portion 20g of the hot water storage tank 20 via the first mixing valve 51, the branch point B2, and the branch point B1. It is a circuit up to. In the fifth circuit, the check valve 65 described above is disposed between the first mixing valve 51 and the branch point B2. Thereby, warm water does not flow in the direction from the first mixing valve 51 toward the branch point B3. Therefore, in the fifth circuit, convection in the direction from the intermediate outflow portion 20d of the hot water storage tank 20 toward the lower inflow portion 20g is prevented.

[Draining work]
Next, the water draining operation at the time of maintenance of the hot water supply apparatus 201 will be described. In the hot water supply apparatus 201, when water is drained from the inside of the hot water storage tank 20 or the piping in the hot water supply / remedy circuit 40, the drainage three-way valve 38 drains hot water in the hot water storage tank 20 from the drain D1. The pressure reducing valve 62 and the drain plug 66 are opened. As a result, air is sucked into the hot water storage tank 20 and the pipe from the relief valve 86, and water in the hot water storage tank 20 and the pipe is drained from the drains D1 and D2, so that water is supplied from the hot water storage tank 20 and the pipe. Unplugging is performed. As described above, the check valve 83 is set so as not to open with the differential pressure P. However, the differential pressure P is smaller than the water pressure inside the pipe from the relief valve 86 to the check valve 83. Is set. Therefore, the check valve 83 is opened by this water pressure, and water can be drained from the hot water storage tank 20 and the inside of the pipe.

  More specifically, for example, the drainage path f21 (from the relief valve 86, through the branch point B3, the check valve 83, the hot water mixing valve 53, the branch point B2, the branch point B1, the pressure reducing valve 62, and the drain plug 66). And the drainage path f22 (from the relief valve 86 to the branch point B3, the check valve 83, the hot water mixing valve 53, the branch point B2, the check valve 65, the first mixing valve). 51, a route in the direction toward the drain port D1 via the intermediate outflow portion 20d, the lower outflow portion 20e of the hot water storage tank 20 and the drainage three-way valve 38), a drainage route f23 (from the relief valve 86, the branch point B3, the hot water storage The water is drained inside the hot water storage tank 20 and the pipe by flowing water through the upper outlet 20c, the lower outlet 20e of the tank 20 and the drainage three-way valve 38 in the direction toward the drain D1). Is done. Here, since each of the drainage paths f21 to f23 is not provided with a check valve through which hot water flows only in the direction from the drainage ports D1 and D2 to the relief valve 86, the drainage channels D21 and f23 are directed toward the drainage ports D1 and D2. Water can flow.

  As described above, the hot water supply apparatus 201 can prevent convection in the first to fifth circuits formed between two different locations of the hot water storage tank 20. Moreover, the water inside the hot water storage tank 20 and the hot water supply / remembrance circuit 40 can be drained from the drains D1 and D2.

<Modification 3>
Fig.10 (a) is a schematic diagram of the hot water supply apparatus 301 of the modification 3 of the said 1st Embodiment. In the modification 3, the same code | symbol is attached | subjected about the element same as the element demonstrated in the said embodiment, and detailed description is abbreviate | omitted.

  As shown to Fig.10 (a), the hot water supply apparatus 301 of the modification 3 is different from the hot water supply apparatus 1 which concerns on the said 1st Embodiment by the following points. That is, the hot water supply apparatus 301 of the third modification is that the check valve 84 is not disposed between the upper outlet portion 20c of the hot water storage tank 20 and the branch point B2, and the upper outlet portion 20b of the hot water storage tank 20 and the second outlet portion 20b. The check valve 73 is not disposed between the mixing valves 52, the check valve 64 is not disposed between the branch point B1 and the lower inflow portion 20g of the hot water tank 20, the branch point B2 and the first point. The check valve 65 is not disposed between the mixing valves 51, and the check valve 365 is disposed between the intermediate outlet 20d of the hot water storage tank 20 and the first mixing valve 51. It is different from the hot water supply apparatus 1 according to the embodiment.

  FIG. 10B to FIG. 10F are diagrams showing circuits formed between two different locations of the hot water storage tank 20.

[First to fifth circuits]
Among the hot water supply / remembrance circuits of the hot water supply apparatus 301 shown in FIG. 10 (a), the circuits indicated by bold lines in FIGS. 10 (b) to 10 (f) are referred to as first circuit to fifth circuit, respectively.

[First circuit]
The first circuit shown in FIG. 10B is from the upper outlet 20b of the hot water tank 20 to the intermediate outlet 20d of the hot water tank 20 via the second mixing valve 52 and the first mixing valve 51. Circuit. In the first circuit, the check valve 72 described above is disposed between the second mixing valve 52 and the first mixing valve 51. Accordingly, in the first circuit, convection in the direction from the first upper outlet 20b of the hot water storage tank 20 toward the intermediate outlet 20d is prevented.

[Second circuit]
The second circuit shown in FIG. 10 (c) is configured such that the hot water storage tank 20 is connected to the hot water tank 20 through the branch point B 3, the hot water mixing valve 53, the branch point B 2, and the first mixing valve 51. This is a circuit up to the intermediate outflow portion 20d. In the second circuit, the above-described check valve 83 is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3. Therefore, in the second circuit, convection in the direction from the upper outlet 20c of the hot water storage tank 20 toward the intermediate outlet 20d is prevented.

[Third circuit]
The third circuit shown in FIG. 10D is a lower inflow of the hot water storage tank 20 from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the hot water mixing valve 53, the branch point B2 and the branch point B1. This is a circuit up to the part 20g. In the third circuit, the above-described check valve 83 is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B3. Accordingly, in the third circuit, convection in the direction from the upper outflow portion 20c toward the lower inflow portion 20g is prevented.

[Fourth circuit]
The fourth circuit shown in FIG. 10 (e) is connected to the hot water storage tank 20 from the upper outlet 20b of the hot water storage tank 20 via the second mixing valve 52, the first mixing valve 51, the branch point B2, and the branch point B1. This is a circuit up to the lower inflow portion 20g. In the fourth circuit, the above-described check valve 72 is disposed between the second mixing valve 52 and the first mixing valve 51. Therefore, in the fourth circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the lower inlet 20g is prevented.

[Fifth circuit]
The fifth circuit shown in FIG. 10 (f) reaches the lower inflow portion 20g of the hot water storage tank 20 from the intermediate outflow portion 20d of the hot water storage tank 20 via the first mixing valve 51, the branch point B2 and the branch point B1. It is a circuit up to. In the fifth circuit, a check valve 365 is disposed between the intermediate outlet 20d of the hot water storage tank 20 and the first mixing valve 51 so that hot water flows only in the direction from the intermediate outlet 20d toward the first mixing valve 51. ing. The check valve 365 is a spring type check valve and is configured to open by a pressure equal to or higher than the above-described differential pressure P. As a result, the check valve 365 does not open with a differential pressure caused by convection from the intermediate outflow portion 20d to the lower inflow portion 20g. Therefore, in the fifth circuit, convection in the direction from the intermediate outflow portion 20d of the hot water storage tank 20 toward the lower inflow portion 20g is prevented.

[Draining work]
Next, the water draining operation at the time of maintenance of the hot water supply apparatus 301 will be described. In the hot water supply apparatus 301, when draining water from the inside of the hot water storage tank 20 or the piping in the hot water supply / remedy circuit 40, the three-way valve for drainage 38 drains hot water in the hot water storage tank 20 from the drain D1. The pressure reducing valve 62 and the drain plug 66 are opened. As a result, air is sucked into the hot water storage tank 20 and the pipe from the relief valve 86, and water in the hot water storage tank 20 and the pipe is drained from the drains D1 and D2, so that water is supplied from the hot water storage tank 20 and the pipe. Unplugging is performed.

  More specifically, for example, the drainage path f31 (from the relief valve 86 to the branch point B3, the hot water mixing valve 53, the branch point B2, the branch point B1, the pressure reducing valve 62, and the drain plug 66) ) Or drainage path f32 (from the relief valve 86, branch point B3, hot water mixing valve 53, branch point B2, first mixing valve 51, check valve 72, second mixing valve 52, hot water storage tank) 20 through the upper outlet 20b, the lower outlet 20e, and the drainage three-way valve 38 to the drain outlet D1), thereby draining water in the hot water storage tank 20 and the piping. Done. Here, since each of the drainage channels f31 and f32 is not provided with a check valve through which hot water flows only in the direction from the drainage ports D1 and D2 to the relief valve 86, the drainage channels D1 and D2 are directed toward the drainage ports D1 and D2. Water can flow.

  As described above, the hot water supply apparatus 301 can prevent convection in the first to fifth circuits formed between two different locations of the hot water storage tank 20. Moreover, the water inside the hot water storage tank 20 and the hot water supply / remembrance circuit 40 can be drained from the drains D1 and D2.

<Modification 4>
Fig.11 (a) is a schematic diagram of the hot water supply apparatus 401 of the modification 4 of the said 1st Embodiment. In the modification example 4, the same elements as those described in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown to Fig.11 (a), the hot water supply apparatus 401 of the modification 4 is different from the hot water supply apparatus 1 which concerns on the said embodiment by the following points. That is, the hot water supply apparatus 401 of the modification 4 is different from the hot water supply apparatus 1 according to the above embodiment in that it does not have an apparatus for supplying hot water to the bath C. Moreover, the hot water supply apparatus 401 of the modification 4 is the hot water supply apparatus 1 which concerns on the said embodiment by the point in which the relief valve 86 is connected to the piping which connects the upper outflow part 20b of the hot water storage tank 20, and the non-return valve 73. Is different.

  FIG. 11B to FIG. 11D are diagrams showing circuits formed between two different locations of the hot water storage tank 20.

[First circuit to third circuit]
Among the hot water supply / remembrance circuits of the hot water supply apparatus 401 shown in FIG. 11 (a), the circuits indicated by bold lines in FIGS. 11 (b) to 11 (d) are referred to as first circuit to third circuit, respectively.

[First circuit]
The first circuit shown in FIG. 11B is from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d of the hot water storage tank 20 via the second mixing valve 52 and the first mixing valve 51. Circuit. In the first circuit, the above-described check valve 73 is disposed between the upper outlet 20b of the hot water tank 20 and the second mixing valve 52. Therefore, in the first circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d is prevented.

[Second circuit]
The second circuit shown in FIG. 11 (c) has a lower inlet 20g of the hot water storage tank 20 from the upper outlet 20b of the hot water storage tank 20 via the second mixing valve 52, the first mixing valve 51 and the branch point B1. It is a circuit up to. In the second circuit, the above-described check valve 73 is disposed between the upper outlet 20 b of the hot water tank 20 and the second mixing valve 52. Accordingly, in the second circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 toward the lower inlet 20g is prevented.

[Third circuit]
The third circuit shown in FIG. 11 (d) is a circuit from the intermediate outflow portion 20d of the hot water storage tank 20 to the lower inflow portion 20g of the hot water storage tank 20 via the first mixing valve 51 and the branch point B1. is there. In the third circuit, the check valve 65 described above is disposed between the first mixing valve 51 and the branch point B3. Accordingly, in the third circuit, convection in the direction from the intermediate outflow portion 20d of the hot water storage tank 20 toward the lower inflow portion 20g is prevented.

[Draining work]
Next, the water draining operation at the time of maintenance of the hot water supply apparatus 401 will be described. When the water heater 401 drains water from the hot water storage tank 20 or the piping in the hot water supply / remembrance circuit 40, the drainage three-way valve 38 drains hot water in the hot water storage tank 20 from the drain D1. In addition, the pressure reducing valve 62 and the drain plug 66 are opened. As a result, air is sucked into the hot water storage tank 20 and the pipe from the relief valve 86, and water in the hot water storage tank 20 and the pipe is drained from the drain D1, thereby draining water from the hot water storage tank 20 and the pipe. Done.

  More specifically, for example, a drainage path f51 (a path in a direction from the relief valve 86 to the drainage port D1 via the upper outlet 20b, the lower outlet 20e of the hot water storage tank 20, and the drainage three-way valve 38). As the water flows through the hot water storage tank 20, the water in the hot water storage tank 20 and the piping is drained. Here, since the above-mentioned drainage path f51 is not provided with a check valve through which hot water flows only in the direction from the drainage port D1 to the relief valve 86, water can flow toward the drainage port D1.

  As described above, the hot water supply apparatus 401 can prevent convection in the first to third circuits formed between two different locations of the hot water storage tank 20. Moreover, the water inside the hot water storage tank 20 and the hot water supply / remembrance circuit 40 can be drained from the drain D1.

  Fig.12 (a) is a schematic diagram of the hot water supply apparatus 1001 of 2nd Embodiment shown in FIG. FIG. 12B to FIG. 12F are diagrams showing a circuit formed between two different locations of the hot water storage tank 20.

[First to fifth circuits]
Among the hot water supply / remembrance circuits of the hot water supply apparatus 1001 shown in FIG. 12 (a), the circuits indicated by bold lines in FIGS. 12 (b) to 12 (f) are referred to as the first circuit to the fifth circuit, respectively.

[First circuit]
The first circuit shown in FIG. 12B is an intermediate outflow portion 20d of the hot water storage tank 20 from the upper outflow portion 20b of the hot water storage tank 20 via the second mixing valve 52, the branch point B102 and the first mixing valve 51. It is a circuit up to. In the first circuit, a check valve 72 through which hot water flows only in the direction from the branch point B102 toward the second mix valve 52 is disposed between the second mix valve 52 and the branch point B102. Thereby, warm water does not flow in the direction from the second mixing valve 52 toward the branch point B102. Therefore, in the first circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the intermediate outlet 20d is prevented.

[Second circuit 2]
The second circuit 2 shown in FIG. 12C is configured so that the hot water storage tank 20 passes from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the hot water mixing valve 53, the branch point B102, and the first mixing valve 51. This is a circuit up to the intermediate outflow portion 20d. In the second circuit 2, the above-described check valve 83 is disposed between the upper outlet 20 c of the hot water storage tank 20 and the branch point B <b> 102. Therefore, in the second circuit 2, the check valve 83 is disposed, thereby preventing convection in the direction from the upper outlet 20 c of the hot water storage tank 20 toward the intermediate outlet 20 d.

[Third circuit]
The third circuit shown in FIG. 12 (d) stores hot water from the upper outlet 20c of the hot water storage tank 20 via the branch point B3, the hot water mixing valve 53, the branch point B102, the first mixing valve 51 and the branch point B1. This is a circuit up to the lower inflow portion 20 g of the tank 20. In the third circuit, the above-described check valve 83 is disposed between the upper outlet 20c of the hot water storage tank 20 and the branch point B102. Therefore, in the third circuit, the check valve 83 is arranged to prevent convection in the direction from the upper outflow portion 20c toward the lower inflow portion 20g.

[Fourth circuit]
The fourth circuit shown in FIG. 12 (e) is configured so that the hot water storage tank 20 has an upper outlet 20b through the second mixing valve 52, the branch point B102, the first mixing valve 51, and the branch point B1. This is a circuit up to the lower inflow portion 20g. In the fourth circuit, the check valve 72 described above is disposed between the second mixing valve 52 and the branch point B102. Therefore, in the fourth circuit, convection in the direction from the upper outlet 20b of the hot water storage tank 20 to the lower inlet 20g is prevented.

[Fifth circuit]
The fifth circuit shown in FIG. 12 (f) is a circuit from the intermediate outflow part 20d of the hot water storage tank 20 to the lower inflow part 20g of the hot water storage tank 20 via the first mixing valve 51 and the branch point B1. is there. In the fifth circuit, the above-described check valve 365 is disposed between the intermediate outlet portion 20 d of the hot water storage tank 20 and the first mixing valve 51. As a result, the check valve 365 does not open with a differential pressure caused by convection from the intermediate outflow portion 20d to the lower inflow portion 20g. Therefore, in the fifth circuit, by arranging the check valve 365, convection in the direction from the intermediate outlet 20d of the hot water storage tank 20 toward the lower inlet 20g is prevented.

[Draining work]
Next, the water draining operation at the time of maintenance of the hot water supply apparatus 1001 will be described. In the hot water supply device 1001, when water is drained from the hot water storage tank 20 or the piping in the hot water supply / remembrance circuit 40, the drainage three-way valve 38 drains the hot water in the hot water storage tank 20 from the drain D1. The pressure reducing valve 62 and the drain plug 66 are opened. As a result, air is sucked into the hot water storage tank 20 and the pipe from the relief valve 86, and water in the hot water storage tank 20 and the pipe is drained from the drains D1 and D2, so that water is supplied from the hot water storage tank 20 and the pipe. Unplugging is performed.

  More specifically, for example, the drainage path f41 (from the relief valve 86 to the branch point B3, the hot water mixing valve 53, the branch point B102, the first mixing valve 51, the branch point B1, the pressure reducing valve 62, and the drain plug 66). Route to the drain outlet D2) and drainage route f42 (from the relief valve 86, branch point B3, hot water mixing valve 53, branch point B102, check valve 72, second mixing valve 52, hot water storage tank) 20 through the upper outlet 20b, the lower outlet 20e, and the drainage three-way valve 38 to the drain outlet D1), thereby draining water in the hot water storage tank 20 and the piping. Done. Here, since each of the drainage channels f41 and 42 is not provided with a check valve through which hot water flows only in the direction from the drainage ports D1 and D2 to the relief valve 86, the drainage channels D41 and 42 are directed toward the drainage ports D1 and D2. Water can flow.

  As described above, the hot water supply apparatus 1001 can prevent convection in the first to fifth circuits formed between two different locations of the hot water storage tank 20. Moreover, the water inside each piping in the hot water storage tank 20 and the hot water supply / remembrance circuit 40 can be drained from the drain outlets D1 and D2.

  In the first and second embodiments and the first to fourth modifications of the first embodiment, the differential pressures P of all the check valves are provided on the upper outlet portion and the lower surface provided on the upper surface of the hot water storage tank 20. When the circuit is formed between the lower inflow part (maximum difference in height), the hot water stored near the upper outflow part and the water stored near the lower inflow part Although an example has been described in which the valve is not opened by the differential pressure even when the “differential pressure due to convection” becomes the largest, such as when the specific gravity difference becomes maximum, the present invention describes this. However, the check valve differential pressure can be set according to the height of the hot water storage tank 20 between two different locations, or the specific gravity difference between hot water and water stored near the two different locations.

  Moreover, in the said 1st, 2nd embodiment and the modification 1-4 of 1st Embodiment, it is piping provided in the upper part of the hot water storage tank 20, and is the circuit from the upper outflow part 20c to the hot water mixing valve 53. The relief valve 86 is connected to the piping or the piping of the circuit from the upper outlet 20b to the second mixing valve 52, but the relief valve 86 may be connected to the upper part of the hot water storage tank 20, It may be connected to a pipe communicating with the space above the hot water storage tank 20.

  In the hot water supply device 401 according to the fourth modification of the first embodiment described above, the example in which the check valve 73 is disposed between the upper outlet 20b of the hot water storage tank 20 and the second mixing valve 52 has been described. Instead of the valve 73, the check valve 72 described above may be disposed between the first mixing valve 51 and the second mixing valve 52. Thus, convection in the direction from the upper outlet 20b of the hot water storage tank 20 toward the intermediate outlet 20d or the lower inlet 20g is prevented. Moreover, in the hot water supply apparatus 401 of the modification 4, the check valves 72 and 73 may be provided side by side.

  In the above-described hot water supply apparatus 401 of the fourth modification, the example in which the check valve 65 is disposed between the branch point B1 and the first mixing valve 51 has been described, but instead of the check valve 65, an intermediate outflow portion is provided. The check valve 365 described above may be disposed between 20d and the first mixing valve 51. This prevents convection in the direction from the intermediate outlet 20d of the hot water storage tank 20 toward the lower inlet 20g. Moreover, in the hot water supply apparatus 401 of the modification 4, check valves 65 and 365 may be provided side by side.

  If the present invention is used, a hot water supply apparatus capable of suppressing fluctuations in the temperature of hot water supplied to a hot water supply terminal can be obtained.

1 Hot-water supply device 2 Heat pump unit (heating means)
3 Hot Water Storage Unit 4 Control Unit 20 Hot Water Storage Tank 20b Upper Outlet (First Outlet)
20c Upper outflow part (third outflow part)
20d Intermediate outflow part (second outflow part)
51 1st mixing valve 52 2nd mixing valve 53 3rd mixing valve 65 check valve 4a hot water supply judgment part 4b 1st mixing valve control part (control means)
4c 2nd mixing valve control part (control means)
4d Intermediate mixing judgment unit (judgment means)
A Karan (1st hot water supply terminal)
B shower (1st hot water supply terminal)
C bath (second hot water supply terminal)

Claims (14)

Heating means for heating hot water;
A hot water storage tank for storing hot water heated by the heating means;
A first outflow part for flowing out hot water from an upper part of the hot water storage tank;
A second outflow part for flowing out warm water from an intermediate part of the hot water storage tank;
A first mixing valve for mixing hot water flowing out from the second outflow portion and water supplied from a water supply source;
A second mixing valve for mixing the hot water mixed by the first mixing valve and the hot water flowing out of the first outflow part;
A first hot water supply terminal to which hot water mixed by the second mixing valve is supplied;
A judging means for judging whether or not the hot water flowing out from the second outflow portion is allowed to pass through the first mixing valve based on the hot water supply flow rate to the first hot water supply terminal;
Control means for controlling the first mixing valve and the second mixing valve;
When the determination means determines that the passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted in the determination means, the first mixing of the hot water flowing out from the second outflow portion A hot water supply apparatus that controls the first mixing valve so as to reduce a passing amount of the valve.   The hot water supply apparatus according to claim 1, wherein a check valve is provided on the water supply source side of the second mixing valve so that water flows only in a direction from the water supply source toward the second mixing valve. . A third outflow part for discharging hot water from the hot water storage tank;
The hot water supply apparatus according to claim 1, further comprising a second hot water supply terminal to which hot water flowing out from the third outflow portion is supplied. Heating means for heating hot water;
A hot water storage tank for storing hot water heated by the heating means;
A first outflow part for flowing out hot water from an upper part of the hot water storage tank;
A second outflow part for flowing out warm water from an intermediate part of the hot water storage tank;
A first mixing valve for mixing the hot water flowing out from the first outflow portion and the hot water flowing out from the second outflow portion;
A second mixing valve for mixing hot water mixed by the first mixing valve and water supplied from a water supply source;
A first hot water supply terminal to which hot water mixed by the second mixing valve is supplied;
A judging means for judging whether or not the hot water flowing out from the second outflow portion is allowed to pass through the first mixing valve based on the hot water supply flow rate to the first hot water supply terminal;
Control means for controlling the first mixing valve and the second mixing valve;
When the determination means determines that the passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted in the determination means, the first mixing of the hot water flowing out from the second outflow portion A hot water supply apparatus that controls the first mixing valve so as to reduce a passing amount of the valve.   The control means sets the first mixing valve to the water supply source side fully opened state when the judging means judges that the passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted. The hot-water supply apparatus in any one of Claims 1-4 characterized by the above-mentioned.   The determination means determines that passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted when the hot water supply flow rate to the first hot water supply terminal is equal to or less than a predetermined amount, The hot water supply flow rate to one hot water supply terminal is determined to permit passage of the first mixing valve of hot water flowing out from the second outflow portion when the flow rate is larger than a predetermined amount. The hot water supply apparatus in any one.   The control means determines that the determination means does not permit passage of the first mixing valve of the hot water flowing out from the second outflow portion when supplying hot water to the first hot water supply terminal, and the second outflow portion After the first mixing valve is controlled so as to reduce the passage amount of the hot water flowing out from the first mixing valve, the hot water flowing out from the second outflow portion in the determination means during the hot water supply The opening degree of the first mixing valve is maintained while the hot water supply is continued even if it is determined that the passage of the one mixing valve is permitted. Water heater. Heating means for heating hot water;
A hot water storage tank for storing hot water heated by the heating means;
A first outflow part for flowing out hot water from an upper part of the hot water storage tank;
A second outflow part for flowing out warm water from an intermediate part of the hot water storage tank;
A third outflow part for discharging hot water from the hot water storage tank;
A first mixing valve for mixing hot water flowing out from the second outflow portion and water supplied from a water supply source;
A second mixing valve for mixing the hot water mixed by the first mixing valve and the hot water flowing out of the first outflow part;
A first hot water supply terminal to which hot water mixed by the second mixing valve is supplied;
A second hot water supply terminal to which hot water flowing out from the third outflow portion is supplied;
A judging means for judging whether or not the hot water flowing out from the second outflow part is allowed to pass through the first mixing valve based on the hot water supply flow rate to the second hot water supply terminal;
Control means for controlling the first mixing valve and the second mixing valve;
When the determination means determines that the passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted in the determination means, the first mixing of the hot water flowing out from the second outflow portion A hot water supply apparatus that controls the first mixing valve so as to reduce a passing amount of the valve.   The control means sets the first mixing valve to the water supply source side fully opened state when the judging means judges that the passage of the hot water flowing out from the second outflow portion through the first mixing valve is not permitted. The hot water supply apparatus according to claim 8.   The determination means permits passage of the hot water flowing out from the second outflow portion through the first mixing valve when a decrease amount per unit time of the hot water supply flow rate to the second hot water supply terminal is a predetermined amount or more. The hot water supply device according to claim 8, wherein it is determined that the hot water supply device is not used.   The determination means determines whether or not to allow the hot water flowing out from the second outflow portion to pass through the first mixing valve based on a hot water supply flow rate to the first hot water supply terminal. The hot water supply device according to any one of claims 8 to 10.   The hot water supply device according to claim 11, wherein a check valve is provided on the water supply source side of the second mixing valve so that water flows only in a direction from the water supply source toward the second mixing valve. .   The control means is determined that the control means does not permit passage of the first mixing valve of the hot water flowing out from the second outflow portion in the determination means at the time of supplying hot water to the first hot water supply terminal, After the first mixing valve is controlled so as to reduce the passage amount of the hot water flowing out from the second outflow portion through the first mixing valve, the determining means causes the outflow from the second outflow portion during the hot water supply. 13. The opening degree of the first mixing valve is maintained while the supply of the hot water is continued even if it is determined that the first mixing valve is allowed to pass through. The hot-water supply apparatus in any one of. The third outflow part is provided in an upper part of the hot water storage tank,
A third mixing valve that mixes the hot water flowing out from the third outflow portion and the water supplied from the water supply source;
The second hot water supply terminal is supplied with hot water mixed by the third mixing valve,
The said control means performs control of the said 3rd mixing valve in addition to control of the said 1st mixing valve and the said 2nd mixing valve, The Claim 2 and any one of Claims 8-13 characterized by the above-mentioned. Water heater.

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