JP2009276033A - Hot water supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply apparatus 11 capable of reducing a boiling-up time and power consumption by sufficiently reducing the loss of the quantity of heat ejected to the outside from a relief valve 33 in a boiling-up time. <P>SOLUTION: Take-out pipelines 25, 26 connected to an upper part and an intermediate part of a hot water storage tank 17 respectively are connected to a mixing valve 28, and a hot water supply pipeline 29 for supplying hot water is connected to the mixing valve 28. The hot water supply pipeline 29 is provided with the relief valve 33 opened to release pressure when the inside of the hot water storage tank 17 reaches a predetermined pressure or higher in the boiling-up time. In the boiling-up time, it is adjusted to take out hot and cold water from the take-out pipeline 26 at the intermediate part by the mixing valve 28. Expanded water discharged to the outside from the relief valve 33 is not hot water of high temperature boiled up and stored on the upper side in the hot water storage tank 17 but water or warm water of low temperature at the intermediate part in the hot water storage tank 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus provided with a relief valve that discharges the expansion of hot water generated when boiling water in a hot water storage tank.

  Conventionally, in a water heater using a heat pump unit to boil hot water stored in a hot water storage tank, during boiling operation, water is taken out from the lower part of the hot water tank and heated to a predetermined boiling temperature by the heat pump unit. By circulating the raised hot water into the upper part of the hot water tank, the hot water formed between the hot water on the upper side and the lower side of the hot water tank due to the specific gravity difference between the hot water and water at different temperatures. Hot water is stored in order from the upper side in the hot water storage tank without being mixed with water through the mixed layer of water.

  In addition, when hot water stored in the hot water storage tank is supplied, the ratio of hot water extraction from the extraction pipes connected to the upper and middle parts of the hot water storage tank, depending on the hot water temperature and amount of remaining hot water in the hot water storage tank. It is taken out by adjusting with a regulating valve and hot water is supplied.

In addition, when the water in the hot water tank rises, the hot water expands in a sealed pipe including the hot water tank, and the gas generated as a result of boiling rises in the upper part of the hot water tank. A relief valve is used to discharge the amount of expansion and the gas accumulated in the upper part of the hot water storage tank to the outside. This relief valve uses a pipe connected to the hot water storage tank and is installed in a pipe that returns the hot water boiled by the heat pump unit to the hot water storage tank, or when it is provided in the upper extraction pipe that takes out hot water from the upper part of the hot water storage tank (For example, refer to Patent Document 1).
JP 2007-333337 A (page 9, FIG. 1)

  However, if the relief valve is installed in a pipe that returns the hot water boiled by the heat pump unit to the hot water storage tank, a part of the hottest hot water immediately after boiling by the heat pump unit is discharged from the relief valve as expansion water. Therefore, there is a problem that the loss of heat is large, and the boiling time is increased correspondingly and the power consumption increases.

  In addition, when the relief valve is provided in the upper extraction pipe for extracting hot water from the upper part of the hot water storage tank, the amount of heat is lost compared with the case where the escape valve is provided in the pipe for returning the hot water heated by the heat pump unit to the hot water storage tank. However, since some of the hottest water in the hot water storage tank is discharged as expansion water from the relief valve to the outside, there is still a large loss of heat, which increases the boiling time and consumption. There is a problem that electric power increases.

  The present invention has been made in view of the above points, and provides a hot water supply apparatus that can sufficiently reduce the loss of heat discharged from the relief valve to the outside during boiling, shorten the boiling time, and reduce power consumption. The purpose is to do.

  The hot water supply apparatus according to claim 1 has a hot water storage tank, a water supply path for supplying water into the hot water storage tank, and a heat pump unit, and takes out water from the lower part of the hot water storage tank and boiles it up to the heat pump unit. A boiling circuit for returning hot water to the upper part of the hot water storage tank, a plurality of extraction pipes connected to different height positions in the vertical direction of the hot water storage tank, and adjusting means for adjusting the extraction of hot water from the plurality of extraction pipes And a hot water supply path having a hot water supply pipe for supplying hot water taken out from the adjusting means, and a relief valve provided in the hot water supply pipe and opened when the pressure inside the hot water storage tank exceeds a predetermined pressure to release the pressure. It is equipped.

  The hot water supply device according to claim 2 is the hot water supply device according to claim 1, wherein the adjusting means closes the upper extraction pipe side among the plurality of extraction pipes during the boiling by the boiling means, and the upper extraction pipe. Open the extraction piping side below the piping side.

  The hot water supply apparatus according to claim 3 is the hot water supply apparatus according to claim 2, wherein the adjusting means is the uppermost extraction pipe until reaching a predetermined hot water supply amount or a predetermined time at the time of hot water supply after completion of boiling. The opening degree on the side is made smaller than the opening degree on the extraction pipe side below the uppermost extraction pipe, and both the upper extraction pipe side and the lower extraction pipe side are opened.

  According to a fourth aspect of the present invention, there is provided the hot water supply apparatus according to the first aspect, wherein the adjustment means sets the opening degree on the uppermost extraction pipe side lower than the uppermost extraction pipe at the time of boiling by the boiling means. Opening both the uppermost extraction piping side and the lower extraction piping side is made less than the opening on the extraction piping side.

  The hot water supply apparatus according to claim 5 is the hot water supply apparatus according to claim 4, wherein the adjusting means closes the uppermost extraction pipe side and opens only the lower extraction pipe side, and the uppermost extraction pipe side. The opening of the uppermost extraction piping side and the lower extraction piping side are both opened while the opening of the lower is less than the opening of the extraction piping side below the uppermost extraction piping. To switch to.

The hot water supply device according to claim 6 is the hot water supply device according to any one of claims 1 to 5, wherein the plurality of extraction pipes are respectively connected to positions of an upper portion, a middle portion and a lower portion of the hot water storage tank,
The adjusting means is for opening the lower take-out piping at the time of boiling by the boiling means.

  According to the hot water supply apparatus of claim 1, since the relief valve is provided in the hot water supply pipe for supplying hot water taken out by the adjusting means from a plurality of extraction pipes connected to different height positions in the vertical direction of the hot water storage tank, By adjusting so that hot water is taken out from the lower take-out piping by this adjusting means, as the expansion water discharged to the outside from the relief valve at the time of boiling, it is heated to the upper side in the hot water tank and stored at a high temperature. Hot water having a temperature lower than that of hot water can be used, loss of heat amount discharged from the relief valve to the outside can be sufficiently reduced, boiling time can be shortened, and power consumption can be reduced.

  According to the hot water supply device of the second aspect, in addition to the effect of the hot water supply device of the first aspect, at the time of boiling, the adjustment means closes the upper extraction pipe side among the plurality of extraction pipes, Since the outlet piping side below the outlet piping side of the hot water is opened, the hot water heated up and stored in the upper part of the hot water storage tank is not discharged from the relief valve, but the amount of heat discharged from the relief valve to the outside Can be reduced sufficiently.

  According to the hot water supply device according to claim 3, in addition to the effect of the hot water supply device according to claim 2, the hot water after completion of boiling is adjusted by the adjusting means until reaching a predetermined hot water supply amount or a predetermined time. In order to open both the uppermost extraction piping side and the lower extraction piping side by opening the opening on the uppermost extraction piping side smaller than the opening on the extraction piping side below the uppermost extraction piping. The hot water heated up and stored in the upper part of the hot water storage tank is prevented from being discharged from the relief valve, while the gas accumulated in the upper part of the hot water storage tank during the boiling is discharged from the relief valve together with the expansion water. It can be discharged to the outside.

  According to the hot water supply apparatus of claim 4, in addition to the effect of the hot water supply apparatus of claim 1, the opening degree on the uppermost extraction pipe side is lowered below the uppermost extraction pipe by the adjusting means during boiling. Open the upper extraction pipe side and the lower extraction pipe side at a smaller opening than the opening on the side extraction pipe side. The amount of heat that is discharged from the relief valve to the outside can be reduced sufficiently, and the gas that accumulates in the upper part of the hot water storage tank during boiling is discharged from the relief valve to the outside together with the expansion water. can do.

  According to the hot water supply device of claim 5, in addition to the effect of the hot water supply device of claim 4, the adjustment means closes the uppermost extraction pipe side and opens only the lower extraction pipe side, Opening both the uppermost extraction piping side and the lower extraction piping side with the opening on the uppermost extraction piping side being smaller than the opening on the extraction piping side below the uppermost extraction piping. Is switched to boiling, the hot water heated up and stored in the upper part of the hot water tank is prevented from being discharged from the relief valve, and is stored in the upper part of the hot water tank at the time of boiling. The discharged gas can be discharged together with the expansion water from the relief valve.

  According to the hot water supply device according to claim 6, in addition to the effect of the hot water supply device according to any one of claims 1 to 5, when the extraction pipe is connected to the upper, middle and lower positions of the hot water storage tank, Since the bottom extraction pipe is opened by the adjusting means at the time of boiling, the lowest temperature hot water in the hot water storage tank can be used as the expansion water, and the loss of heat discharged from the relief valve to the outside can be sufficiently reduced. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a first embodiment.

  The hot water supply device 11 includes a tank unit 12 for storing hot water and a heat pump unit 13 for boiling the hot water.

  The tank unit 12 includes a hot water storage tank 17 for storing hot water. The hot water storage tank 17 includes an upper position of the hot water storage tank 17 and a 1/5 position and a 2/5 position corresponding to the capacity from the upper portion of the hot water storage tank 17. The thermistors 18a to 18f as temperature detecting means for detecting the hot water temperature in the hot water storage tank 17 are disposed at the 3/5 position, the 4/5 position, and the lower position of the hot water storage tank 17, respectively.

  A water supply path 20 connected to a water supply source such as a water pipe is connected to the lower part of the hot water storage tank 17. The water supply path 20 is provided with a pressure reducing valve 21 for reducing the water supply pressure and a check valve 22 for preventing backflow.

  An upper extraction pipe 25 is connected to the upper part of the hot water storage tank 17, and an intermediate extraction pipe is located between the thermistor 18b at the 1/5 position and the thermistor 18c at the 2/5 position, which is an intermediate position in the vertical direction of the hot water storage tank 17. 26 is connected. The upper take-out pipe 25 and the intermediate take-out pipe 26 are connected to a mixing valve 28 which is an electric valve as the adjusting means 27. By this mixing valve 28, the hot water taken out from the upper take-out pipe 25 and the middle take-out pipe The mixing ratio with hot water taken out from the pipe 26 is adjusted. The mixing ratio that can be adjusted by the mixing valve 28 includes the case where either one is 100% and the other is 0%.

  The mixing valve 28 is connected to a hot water supply pipe 29 for supplying hot water taken out. The hot water supply pipe 29 is provided with an extraction temperature detection sensor 30 as an extraction temperature detection means for detecting the temperature of the hot water.

  The extraction pipes 25 and 26, the mixing valve 28, and the hot water supply pipe 29 constitute a hot water supply path 31 for supplying hot water taken out from the hot water storage tank 17.

  The hot water supply pipe 29 is provided with a relief valve 33 for discharging the expanded water during boiling and the gas accumulated in the hot water storage tank 17 to the outside, and a drain passage 34 for discharging the expanded water and gas discharged by the relief valve 33 to the outside. It is connected.

  The hot water storage tank 17 of the tank unit 12 and the heat pump unit 13 are connected by a boiling circuit 40. The boiling circuit 40 has an outgoing path 41 that connects the hot water storage tank 17 and the inlet side of the heat pump unit 13, and a return path 42 that connects the hot water storage tank 17 and the outlet side of the heat pump unit 13. The forward path 41 is configured by connecting a pipe 41a in the tank unit 12 and a pipe 41b in the heat pump unit 13 by a pipe 41c. The return path 42 is configured by connecting a pipe 42a in the tank unit 12 and a pipe 42b in the heat pump unit 13 by a pipe 42c.

  A pipe 41a of the outgoing path 41 is connected to the lower part of the hot water storage tank 17, and a drain valve 43 for draining the water in the hot water storage tank 17 to the outside is disposed in the pipe 41a.

  A switching valve 45 as a switching means is connected to the piping 42a of the return path 42. The hot water storage tank 17 is connected to the switching valve 45 through an upper return piping 46 connected to the upper part of the hot water storage tank 17 and a piping 41a of the outgoing path 41. A lower return pipe 47 connected to the lower part of the pipe is connected. Then, the switching valve 45 switches so that either the upper return pipe 46 or the lower return pipe 47 is connected to the heat pump unit 13 side.

  The heat pump unit 13 includes a refrigerant circuit including a compressor, a heat exchanger 50 that functions as a condenser, an expansion valve, an evaporator, and the like. A boiling circuit 40 is connected to the heat exchanger 50 of the heat pump unit 13. In the pipe 41b on the inlet side of the heat exchanger 50 of the heat pump unit 13, a circulation pump 51 that circulates the water in the lower part of the hot water storage tank 17 from the forward path 41 side to the return path 42 side is disposed. Further, a water supply temperature sensor 52 for detecting the temperature of the water taken into the outgoing path 41 is provided in the pipe 41b on the inlet side of the heat exchanger 50, and the heat exchanger 50 is provided in the pipe 42b on the outlet side of the heat exchanger 50. A boiling temperature sensor 53 that detects the temperature of hot water that has passed 50 is provided.

  In addition, the hot water supply device 11 has a control unit 60 that controls the operation of the hot water supply device 11. The controller 60 controls the mixing valve 28 at the time of boiling, and performs first relief control for controlling the mixing valve 28 so as to close the upper extraction pipe 25 side and open the intermediate extraction pipe 26 side. Function or mixing valve to open both the upper extraction pipe 25 side and the intermediate extraction pipe 26 side with the opening degree on the upper extraction pipe 25 side being smaller than the opening degree on the intermediate extraction pipe 26 side A second escape control function for controlling 28 is provided.

  In the case of the first escape control, when the hot water is supplied after the completion of boiling, the opening on the upper outlet pipe 25 side is set to the intermediate outlet pipe 26 side until reaching either a predetermined hot water supply amount or a predetermined time. The opening has a function of opening both the upper extraction pipe 25 side and the lower extraction pipe 26 side.

  In the case of the second escape control, the upper outlet pipe 25 side is closed and only the intermediate outlet pipe 26 side is opened, and the opening degree on the upper outlet pipe 25 side is set to the intermediate outlet pipe 26 side. It has a function of switching the state in which both the upper extraction pipe 25 side and the intermediate extraction pipe 26 side are open to the boiling state with less than the opening degree.

  Next, the operation of the present embodiment will be described.

  When the water in the hot water storage tank 17 is boiled up, the heat pump unit 13 and the circulation pump 51 are operated.

  As shown by black piping and arrows in FIG. 1, the water in the lower part of the hot water storage tank 17 is caused by the operation of the circulation pump 51 so that the pipes 41 a, 41 c, 41 b of the outgoing path 41, the circulation pump 51 of the heat pump unit 13 and the heat It flows into the hot water storage tank 17 through the exchanger 50, the pipes 42b, 42c, 42a of the return path 42, the switching valve 45, the upper return pipe 46 or the lower return pipe 47. Water flowing in the boiling circuit 40 is boiled by the heat pump unit 13.

  Since the boiling temperature is low in the initial operation of the heat pump unit 13 and the temperature detected by the boiling temperature sensor 53 is lower than the predetermined boiling temperature, the temperature at which the switching valve 45 switches to the lower return pipe 47 and passes through the heat pump unit 13 The low boiling water is returned to the lower part of the hot water storage tank 17, but since the boiling temperature becomes high after the initial operation of the heat pump unit 13, if the temperature detected by the boiling temperature sensor 53 is higher than the predetermined boiling temperature, switching is performed. The valve 45 is switched to the upper return pipe 46 and the hot water heated by the heat pump unit 13 is returned to the upper part of the hot water storage tank 17.

  By returning the hot water boiled by the heat pump unit 13 to the upper part of the hot water storage tank 17, there is a difference in specific gravity between hot water and water having different temperatures in the hot water storage tank 17, so that Hot water is stored in order from the upper side in the hot water storage tank 17 without being mixed with water through the mixed layer of hot water and water formed between the water.

  Further, at the time of boiling, the hot water expands in a sealed pipe including the inside of the hot water storage tank 17 due to the rise in the temperature of the hot water, and further, the gas in the vaporized liquid enters the hot water storage tank 17 due to the boiling by the heat pump unit 13. The water is sent and collected in the upper part of the hot water storage tank 17, but the expanded water and gas are released from the relief valve 33 to the outside through the drainage path 34.

  In order to allow the expanded water and gas to escape from the relief valve 33, either the first relief control or the second relief control is used.

  In the first escape control, during the boiling operation, the upper outlet pipe 25 side is closed and the intermediate outlet pipe 26 side is opened by the mixing valve 28 in advance, so that the intermediate part in the hot water storage tank 17 is opened. Or hot water whose temperature has been lowered without being used for hot water supply is discharged as expanded water through the extraction pipe 26 in the intermediate portion.

  Therefore, hot water having a temperature lower than that of hot water heated up and stored in the upper portion of the hot water storage tank 17 can be used as the expansion water discharged to the outside from the relief valve 33 at the time of boiling, that is, the hot water storage tank. The hot water boiled and stored in the upper part of 17 is not discharged from the relief valve 33, and the loss of the amount of heat discharged from the relief valve 33 to the outside can be reduced sufficiently, shortening the boiling time and power consumption Can be reduced.

  Further, when the hot water is supplied after the completion of boiling, the opening on the side of the upper extraction pipe 25 is controlled by the mixing valve 28 until either a predetermined hot water supply amount (for example, 50 L) or a predetermined cumulative time (for example, 10 minutes) is reached. The opening on the side of the extraction pipe 26 in the middle is made smaller than that, and both the extraction pipes 25 and 26 are opened.

  As a result, as shown by the black piping and the arrow in FIG. 2, the hot water storage tank 17 is restrained from discharging the hot water heated up and stored in the hot water storage tank 17 from the relief valve 33. The gas accumulated in the upper part of 17 can be discharged to the outside from the relief valve 33 together with the expansion water.

  It should be noted that the gas accumulated in the upper part of the hot water storage tank 17 can be reliably discharged by the opening degree of the upper part of the mixing valve 28 on the outlet pipe 25 side, a predetermined hot water supply amount (for example, 50 L) or a predetermined cumulative time (for example, 10 minutes). Thus, it is set as appropriate. In particular, since the gas flows out together with the hot water discharged from the faucet by hot water supply, the opening on the outlet pipe 25 side above the mixing valve 28 is prevented so that no sound is generated or scattered due to the gas discharged from the faucet. Is set.

  On the other hand, in the second relief control, during the boiling operation, the opening degree on the upper extraction pipe 25 side is made smaller than the opening degree on the intermediate extraction pipe 26 side by the mixing valve 28, and the extraction pipe 25 is added thereto. Open both sides.

  As a result, as shown by black piping and arrows in FIG. 2, mainly from the relief valve 33, water in the intermediate portion in the hot water storage tank 17 or hot water whose temperature has dropped without being used for hot water supply is taken out from the intermediate portion. It is discharged as expanded water through the pipe 26, and the gas accumulated in the upper portion of the hot water storage tank 17 is discharged, and a small amount of hot water in the upper portion of the hot water storage tank 17 is discharged.

  Therefore, it is possible to suppress the loss of the amount of heat discharged from the relief valve 33 to the outside by suppressing the high temperature hot water boiled and stored in the hot water storage tank 17 from the relief valve 33, In addition, the gas accumulated in the upper part of the hot water storage tank 17 can be discharged from the relief valve 33 together with the expansion water.

  In this second relief control, the mixing valve 28 normally closes the upper extraction pipe 25 side and opens only the intermediate extraction pipe 26 side, and periodically (for example, every 5 minutes for 5 minutes). Ratio) or just before completion of boiling, the opening on the upper extraction pipe 25 side is made smaller than the opening on the intermediate extraction pipe 26 side, so that both the extraction pipes 25 and 26 are opened. If so, the gas accumulated in the upper part of the hot water tank 17 is released while the hot water heated up and stored in the upper part of the hot water tank 17 is suppressed from being discharged from the escape valve 33 as much as possible. Can be discharged to the outside.

  The opening of the upper part of the mixing valve 28 on the outlet pipe 25 side and the opening time thereof are set as appropriate so that the gas accumulated in the upper part of the hot water storage tank 17 can be discharged reliably.

  Next, FIG. 3 shows a second embodiment.

  In the first embodiment, a lower take-out pipe 71 is connected to the lower part of the hot water storage tank 17, and the intermediate take-out pipe 26 and the lower take-out pipe 71 constitute a part of the adjusting means 27. To the mixing valve. The switching valve 72 switches so that one of the intermediate extraction pipe 26 and the lower extraction pipe 71 is closed and the other is opened.

  The control unit 60 controls to open the lower extraction pipe 71 during boiling.

  Thus, when the extraction pipes 25, 26, 71 are connected to the upper, intermediate and lower positions of the hot water storage tank 17, respectively, the intermediate extraction pipe 26 is closed by the switching valve 72 during boiling, Since the lower extraction pipe 71 is opened, the water in the hot water storage tank 17 and the hottest water at the lowest temperature can be used as the expansion water until the boiling is nearly completed, and the loss of heat discharged from the relief valve 33 to the outside is sufficient. Can be less.

  Also in the case of the second embodiment, the first relief control and the second relief described above are performed except that the intermediate outlet pipe 26 is closed by the switching valve 72 and the lower outlet pipe 71 is opened. Control can be applied.

  When hot water is supplied, the lower take-out pipe 71 is closed by the switching valve 72 and the intermediate take-out pipe 26 is opened, so that hot water can be taken out from the intermediate part of the hot water storage tank 17 and hot water can be supplied.

  If priority is given to the reduction of the medium-temperature water remaining in the intermediate part of the hot water storage tank 17, the switching pipe 72 opens the intermediate extraction pipe 26, and the amount of heat discharged to the outside from the relief valve 33 is lost. In the case where priority is given to reducing the amount, it may be possible to select and set the switching valve 72 so that the lower extraction pipe 71 is opened.

  Next, FIG. 4 shows a third embodiment.

  In the second embodiment, the lower take-out piping 71 is connected to the water supply path 20 so that the water in the lower part of the hot water storage tank 17 can be taken out via the water supply path 20. The effect is the same as in the second embodiment.

It is a block diagram which shows the boiling-up operation | movement of the hot-water supply apparatus which shows the 1st Embodiment of this invention. It is a block diagram which shows the other boiling operation of a hot-water supply apparatus same as the above. It is a block diagram which shows the boiling-up operation | movement of the hot-water supply apparatus which shows the 2nd Embodiment of this invention. It is a block diagram which shows the boiling-up operation | movement of the hot-water supply apparatus which shows the 3rd Embodiment of this invention.

Explanation of symbols

11 Water heater
13 Heat pump unit
17 Hot water storage tank
20 Water supply route
25, 26 Extraction piping
27 Adjustment means
29 Hot water supply piping
31 Hot water supply route
33 Relief valve
40 Boiling circuit
71 Extraction piping

Claims (6)

A hot water storage tank,
A water supply path for supplying water into the hot water storage tank,
A heating circuit having a heat pump unit, taking out water from the lower part of the hot water storage tank and boiling it with the heat pump unit, and returning the heated hot water to the upper part of the hot water storage tank;
A plurality of outlet pipes respectively connected to different height positions in the vertical direction of the hot water storage tank, an adjusting means for adjusting the extraction of hot water from the plurality of outlet pipes, and a hot water supply pipe for supplying hot water taken out from the adjusting means A hot water supply path having
A hot water supply apparatus, comprising: a relief valve that is provided in the hot water supply pipe and opens to release the pressure when the inside of the hot water storage tank becomes a predetermined pressure or higher. The adjustment means closes the upper extraction pipe side among the plurality of extraction pipes and raises the lower extraction pipe side from the upper extraction pipe side when boiling by the boiling means. 1. A hot water supply apparatus according to 1. The adjustment means adjusts the opening on the uppermost extraction pipe side below the uppermost extraction pipe side until reaching either a predetermined hot water supply amount or a predetermined time at the time of hot water supply after completion of boiling. The hot water supply apparatus according to claim 2, wherein both the uppermost extraction pipe side and the lower extraction pipe side are opened with an opening smaller than the opening degree. The adjusting means is configured to reduce the opening degree on the uppermost extraction pipe side lower than the opening degree on the lower extraction pipe side from the uppermost extraction pipe side when raising by the boiling means. The hot water supply apparatus according to claim 1, wherein both the lower extraction pipe side are opened. The adjustment means closes the uppermost extraction piping side and opens only the lower extraction piping side, and adjusts the opening of the uppermost extraction piping side to the extraction piping side below the uppermost extraction piping. The hot water supply apparatus according to claim 4, wherein a state in which both the uppermost extraction pipe side and the lower extraction pipe side are opened less than the opening degree is switched during boiling. A plurality of outlet pipes are connected to the upper, middle and lower positions of the hot water storage tank,
The hot water supply apparatus according to any one of claims 1 to 5, wherein the adjusting means opens the lower take-out pipe when boiling by the boiling means.

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