JP5275172B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type hot water supply apparatus installed via an antifreeze water drain plug.

  Conventionally, in this type of hot water storage type hot water supply apparatus, as shown in FIG. 5, a hot water storage tank 101 for storing hot water, heating means 102 for heating hot water in the hot water storage tank 101, and water supply for supplying water to the lower part of the hot water storage tank 101. A pipe 103, an upper hot water discharge pipe 104 discharged from the upper part of the hot water storage tank 101, an intermediate hot water discharge pipe 105 discharged from the intermediate part of the hot water storage tank 101, and a three-way valve 106 for selecting one of the upper hot water discharge pipe 104 and the intermediate hot water discharge pipe 105. A hot water supply pipe 107 connected to the hot water outlet side of the three-way valve 106, and a negative pressure intake valve 108 that sucks air when the hot water storage tank 101 reaches a predetermined negative pressure state. When there was hot water, there was one that tried to pour all or part of the hot water from the intermediate tapping pipe 105 (see Patent Document 1).

  In cold regions, an antifreeze drain plug 109 for draining hot water in the water supply pipe 103 and the hot water supply pipe 107 is provided in order to prevent freezing of the water supply pipe 103 and the hot water supply pipe 107 near the ground surface or in the house. In some cases, a hot water storage type hot water supply apparatus is installed. The antifreezing water drain plug 109 is buried below the freezing depth determined for each region, and can be manually or electrically switched to a drained state or a water supply state, as shown in Patent Document 2 and Patent Document 3. Things are known.

JP 2003-240342 A Japanese Utility Model Publication No. 60-175963 JP 2001-4056 A

  However, in such a hot water storage type hot water supply apparatus, when the three-way valve 106 is in communication with the intermediate hot water discharge pipe 105 side, the hot water from the water supply pipe 103 and the hot water supply pipe 107 is drained with the antifreeze water drain plug 109 drained. Alternatively, when the three-way valve 106 communicates with the intermediate hot water pipe 105 side when the antifreeze water draining plug 109 is in a drained state, the water from the hot water supply pipe 107 is drained from the intermediate portion of the hot water storage tank 101 by siphon phenomenon. The hot water in the hot water storage tank 101 is drained until the hot water in the upper part is sucked out from the intermediate hot water discharge pipe 105 and air is introduced from the negative pressure intake valve 108 until the water level drops to the connection position of the intermediate hot water discharge pipe 105. was there.

  In order to solve the above problems, the present invention provides a hot water storage tank for storing hot water, heating means for heating the hot water in the hot water storage tank, a water supply pipe for supplying water to the lower part of the hot water storage tank, and the water supply pipe. Any one of a feed water pressure detecting means for detecting a feed water pressure, an upper hot water discharge pipe for discharging hot water from the upper part of the hot water storage tank, an intermediate hot water discharge pipe for discharging hot water from an intermediate part of the hot water storage tank, and the upper hot water discharge pipe and the intermediate hot water discharge pipe In a hot water storage type hot water supply apparatus comprising switching means for selecting one of these, a hot water pipe connected to the hot water outlet side of the switching means, and a hot water flow rate detecting means provided in the hot water pipe, the operation of the antifreeze water drain plug There is provided a water draining operation detecting means for detecting drainage of the hot water supply pipe by the water draining operation detecting means, wherein the hot water supply flow rate detecting means detects a predetermined flow rate, and the water supply pressure detecting means detects a predetermined pressure or less. Then, before By detecting the operation of the non-freezing water vent plug, said switching means communicating the upper hot water pipe side, and so as to close the intermediate tapping pipe side.

  Further, in claim 2, a hot water storage tank for storing hot water, a heating means for heating the hot water in the hot water storage tank, a water supply pipe for supplying water to the lower part of the hot water storage tank, and a water flow detection provided in the water supply pipe for detecting a water flow. Switching means for selecting any one of the upper tapping pipe discharging from the upper part of the hot water storage tank, the intermediate tapping pipe discharging from the middle part of the hot water storage tank, and the upper tapping pipe and the intermediate tapping pipe. In a hot water storage type hot water supply apparatus comprising a hot water supply pipe connected to the hot water supply side of the means and a hot water supply flow rate detection means provided in the hot water supply pipe, a drain for detecting drainage of the hot water supply pipe due to the operation of an antifreeze water drain plug An operation detecting means is provided, and when the hot water flow rate detecting means detects a predetermined flow rate and the water flow detecting means detects no water flow, it detects the operation of the antifreeze drain plug. , Switching The stage communicates the upper hot water pipe side, and so as to close the intermediate tapping pipe side.

  According to a third aspect of the present invention, after the switching means is connected to the upper tapping pipe side and the intermediate tapping pipe side is closed by detecting the operation of the draining action detecting means, the draining action detecting means is When the return of the feed water pressure is detected based on the feed water pressure detected by the feed water pressure detecting means, the switching means is closed on the upper hot water discharge pipe side and communicated with the intermediate hot water discharge pipe side.

  According to a fourth aspect of the present invention, the switching means is communicated with the upper tapping pipe side and the intermediate tapping pipe side is closed by detecting the operation of the water draining action detecting means, and then the hot water supply flow rate detecting means performs a predetermined operation. When a flow rate equal to or higher than the flow rate is detected, the switching means is closed on the upper hot water discharge pipe side and communicated with the intermediate hot water discharge pipe side.

  Thus, even when the antifreeze drain plug is in a drained state, the hot water drainage in the hot water storage tank can be minimized, so that waste of water resources and waste of energy by heating the hot water can be eliminated.

The schematic block diagram of one Embodiment of this invention. The flowchart for demonstrating the action | operation of the same embodiment. The schematic block diagram of other embodiment of this invention. The flowchart for demonstrating the action | operation of the other embodiment. The schematic block diagram of the conventional hot water storage type hot-water supply apparatus.

  Next, a hot water storage type hot water supply apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a hot water storage tank for storing hot water, 2 is a water supply pipe connected to the bottom of the hot water storage tank 1, 3 is an upper hot water discharge pipe connected to the top of the hot water storage tank 1, and 4 is an intermediate hot water discharge pipe connected to the intermediate part of the hot water storage tank 1. Reference numeral 5 denotes a three-way valve as a switching means for switching hot water from the upper hot water discharge pipe 3 and hot water from the intermediate hot water discharge pipe 4, 6 is a water supply bypass pipe branched from the water supply pipe 2, and 7 is a three-way valve. 5 is a mixing valve capable of mixing the hot water from 5 and the water from the water supply bypass pipe 6 and changing the mixing ratio, and 8 is a hot water supply for supplying hot water mixed by the mixing valve 7 to a hot water supply terminal (not shown). A pipe 9 is a circulation circuit in which hot and cold water is connected to the lower and upper portions of the hot water storage tank 1, and 10 is a circulation pump which is provided in the middle of the circulation circuit 9 and whose rotation speed can be varied.

  Reference numeral 11 denotes a compressor that compresses and discharges refrigerant and has a variable number of revolutions. Reference numeral 12 denotes that the refrigerant from the compressor 11 is circulated on the primary side and water in the circulation circuit 9 is circulated on the secondary side to dissipate heat from the high-temperature and high-pressure refrigerant. A water-refrigerant heat exchanger for heating water, 13 is a variable-pressure decompressor that decompresses and expands the refrigerant from the water-refrigerant heat exchanger 7, 14 is an evaporator that evaporates the refrigerant decompressed by the decompressor 13, Reference numeral 15 denotes a blower having a variable number of revolutions for supplying atmospheric heat to the evaporator 14, and the compressor 11, the water / refrigerant heat exchanger 12, the decompressor 13, and the evaporator 14 constitute a heating means 16.

  A water supply pressure reducing valve 17 is provided in the middle of the water supply pipe 2 and reduces the city water to a constant water pressure (for example, a set pressure value of 170 kPa). The water supply pressure reducing valve 17 supplies hot water in the hot water storage tank 1 upstream of the water supply pressure reducing valve 17. It also has the function of a check valve that does not flow back to the side. A pressure sensor 18 is provided in the middle of the water supply pipe 2 and downstream of the water supply pressure reducing valve 17 as a water supply pressure detecting means for detecting a water supply pressure, and 19 is provided in communication with the upper part of the hot water storage tank 1. Is a negative pressure intake valve that opens when the air pressure becomes negative, and introduces air into the hot water storage tank 1, and 20 is interposed between the primary side of the water supply pressure reducing valve 17 and a position branched from the hot water supply pipe 8, and below the freezing depth. The antifreeze drain plug for stopping water supply and draining the water supply pipe 2 and the hot water supply pipe 8, 20a is an operation handle for the antifreeze drain pipe 20, and 20b is antifreeze water. A drain port 20 c of the drain plug 20 is a hot water outlet of the antifreeze water drain plug 20.

  A plurality of hot water storage sensors 21a to e are provided on the upper and lower sides of the hot water storage tank 1 to detect the hot water storage temperature in the hot water storage tank 1, and 22 is provided in the middle of the hot water supply pipe 8 to detect the hot water supply flow rate based on the rotational speed of the internal impeller. A hot water flow rate sensor as hot water flow rate detection means, 23 is a hot water temperature sensor for detecting the hot water temperature, 24 is a hot water temperature sensor for detecting the hot water temperature, and 25 is provided in the middle of the circulation circuit 9 and flows into the water / refrigerant heat exchanger 12. An incoming water temperature sensor 26 detects the temperature of the hot water (incoming water temperature), and 26 is a boiling temperature sensor which is provided in the middle of the circulation circuit 9 and detects the temperature (boiling temperature) of the hot water returning from the water / refrigerant heat exchanger 12 to the hot water storage tank 1. , 27 is a discharge temperature sensor that detects the temperature (discharge temperature) of the refrigerant flowing from the compressor 11 into the water refrigerant heat exchanger 12.

  Reference numeral 28 denotes a remote controller having a hot water supply temperature setting switch 28a for setting a desired hot water supply temperature (hot water supply set temperature), another setting switch 28b, and a display 28c for displaying the hot water supply set temperature.

  29 is input with detection values of the pressure sensor 18, hot water storage temperature sensors 21 a to 21 e, hot water flow rate sensor 22, hot water supply temperature sensor 23, water supply temperature sensor 24, incoming water temperature sensor 25, boiling temperature sensor 26, and discharge temperature sensor 27. A controller that is communicably connected to the remote controller 28 and controls operations of the three-way valve 5, the mixing valve 7, the circulation pump 10, the compressor 11, the decompressor 13, and the blower 15 according to a program stored in advance.

  The controller 29 is provided with a water draining operation detecting means 29a, which detects that the antifreeze water draining plug 20 has been drained and communicates the three-way valve 5 with the upper hot water discharge pipe 3 side and the intermediate hot water discharge pipe 4 side. To block. Further, the drainage operation detecting means 29a detects the return of the water supply pressure based on the water supply pressure detected by the pressure sensor 18 after the antifreeze water drain plug 20 is drained, and the antifreeze water drain plug 20 performs the water supply operation. When this is detected, the three-way valve 5 is closed on the upper hot water discharge pipe 3 side and communicated with the intermediate hot water discharge pipe 4 side.

  Next, the operation of this embodiment will be described.

  When the hot water supply terminal is opened and hot water supply is started, when the amount of hot water detected by the hot water storage temperature sensors 21a to 21e is large and there is hot water below the vicinity of the middle portion of the hot water storage tank 1, the control unit 29 has a three-way valve. 5 is connected to the intermediate hot water discharge pipe 4 side and the upper hot water discharge pipe 3 side is closed, hot water is discharged from the intermediate portion of the hot water storage tank 1, and the hot water supply temperature detected by the hot water supply temperature sensor 23 is set to the hot water supply temperature. Adjust the water temperature so that it is hot. On the other hand, when the amount of hot water stored in the hot water storage tank 1 is reduced and there is no hot water in the vicinity of the intermediate portion of the hot water storage tank 1, the control unit 29 closes the three-way valve 5 on the intermediate hot water discharge pipe 4 side. As the state of communication, the hot water is discharged from the upper part of the hot water storage tank 1.

  As described above, when the amount of hot water in the hot water storage tank 1 is sufficient, the hot water is discharged from the intermediate portion of the hot water storage tank 1, and when the amount of hot water is not sufficient, the hot water is discharged from the upper portion of the hot water storage tank 1. The hot water whose temperature has decreased can be consumed before the hot water in the upper part of the hot water storage tank 1, so hot hot water remains in the upper part of the hot water storage tank 1, and the hot water in the lower part of the hot water storage tank 1 is not supplied from the hot water. You can leave a cold water supply.

  Then, when the midnight time zone in which the power unit price is low is reached, the control unit 29 detects the rated heating capacity of the heating means 16 with the boiling target temperature and the hot water storage temperature sensor 21e at the bottom, and the heated water at the bottom of the hot water storage tank 1 The target circulation amount of water to be heated that is allowed to pass through the heating means 16 by dividing by the temperature difference from the temperature of the above is calculated, and from the relationship (formula or data map) between the target circulation amount and the target rotation speed stored in advance, The target rotational speed of the circulation pump 10 corresponding to the target circulation amount is set, the operation of the compressor 11, the decompressor 13 and the blower 15 is started to drive the heating means 16 and the circulation pump 10 is driven at the target rotational speed. Then start boiling operation.

  At this time, in the hot water storage tank 1, hot water that can be used as hot water the next day and cold water supply are left, and hot water at an intermediate temperature is discharged as much as possible, so that it remains in the heat pump heating means 16. When raising the temperature, the boiling operation can be performed in a state where the COP (heating efficiency) is good.

  When the hot water storage temperature sensor 21e at the lowermost part of the hot water storage tank 1 detects that the temperature has reached a predetermined temperature or when the current time reaches the end time of the midnight time zone, the control unit 29 causes the compressor 11 and the decompressor 13 to The operation of the blower 15 is stopped to stop the heating means 16 and the circulation pump 10 is stopped to end the boiling operation.

  At this time, when the controller 29 performs a boiling operation so that the amount of hot water stored in the hot water storage tank 1 is lower than the position where the intermediate hot water discharge pipe 4 is attached, this is detected by the hot water storage temperature sensors 21a to 21e. The valve 5 is connected to the intermediate hot water discharge pipe 4 side and the upper hot water discharge pipe 3 side is closed so that hot water can be discharged from the intermediate portion of the hot water storage tank 1 simultaneously with the start of hot water supply.

  Next, the case where the antifreeze drain plug 20 is opened and drained by the user when there is a risk of freezing in winter in the hot water storage type hot water supply apparatus shown in FIG. 1 will be described based on the flowchart shown in FIG.

  When the operation handle 20a of the antifreeze water drain plug 20 is operated by the user and the drainage operation is started, the water in the water supply pipe 2 and the hot water in the hot water pipe 8 are respectively connected to the drain outlet 20b of the antifreeze water drain plug 20. Air is introduced into the hot water storage tank 1 from the negative pressure intake valve 19 discharged from the hot water outlet 20 c and communicated with the upper part of the hot water storage tank 1.

  Along with this drainage operation, the hot water supply flow rate sensor 22 provided in the hot water supply pipe 8 detects a predetermined flow rate (for example, about 2 pps to 10 pps) lower than that during normal hot water supply (step S1), and the pressure sensor 18 Predetermined pressure (for example, a pressure value that can be regarded as being drained by the operation of the antifreeze water drain plug 20 or a set pressure value 170 kPa of the feed water pressure reducing valve 17 that is detected in a normal use state. When a low pressure value (for example, 50 kPa) or less is detected (step S2) and this state is continued for a certain period of time, the water draining operation detecting means 29a is used as drainage of the hot water supply pipe 8 by the operation of the antifreezing water draining plug 20. The three-way valve 5 is connected to the upper hot water discharge pipe 3 side, and the intermediate hot water discharge pipe 4 side is closed (step S3).

  Then, the operation handle 20a of the antifreeze water drain plug 20 is closed by the user, and the water supply is resumed. The water supply pressure detected by the pressure sensor 18 rises to 170 kPa, which is the set pressure value of the water supply pressure reducing valve 17, and the water is drained. When the operation detection unit 29a detects the return of the water supply pressure based on the water supply pressure detected by the pressure sensor 18, that is, detects that the antifreeze water drain plug 20 has changed from the drained state to the water supply state (step S4). Then, the three-way valve 5 is closed on the upper hot water discharge pipe 3 side, and the intermediate hot water discharge pipe 4 side is in communication (step S5).

  In this way, when drainage from the hot water supply pipe 8 is detected, the three-way valve 5 is closed on the intermediate hot water discharge pipe 4 side and communicated with the upper hot water discharge pipe 3 side. The air from the negative pressure intake valve 19 is introduced to the hot water drainage of the hot water storage tank 1 due to the siphon phenomenon, so that the hot water drainage from the hot water storage tank 1 can be minimized. It is possible to eliminate waste of energy by heating hot water.

  Further, when the water supply pressure is restored, the three-way valve 5 is returned to the state where the intermediate hot water discharge pipe 4 is communicated, so that hot water having an intermediate temperature in the hot water storage tank 1 can be preferentially discharged. When raising the temperature, the boiling operation can be performed in a state where the COP (heating efficiency) is good.

  Further, conventionally, the amount of hot water is reduced due to the removal of hot water in the hot water storage tank 1, and if the hot water supply is used as it is, there has been a shortage of hot water that has disappeared. Since no hot water can be removed, it is possible to prevent this hot water from occurring. Conventionally, since a large amount of air is contained in the hot water storage tank 1, it is necessary to remove this large amount of air before hot water supply, but this is also unnecessary.

  Note that the present invention is not limited to the above-described embodiment, and in this embodiment, the water draining operation detection unit 29a detects the return of the feed water pressure based on the feed water pressure detected by the pressure sensor 18, that is, The three-way valve 5 is switched to the intermediate side when it is detected that the antifreeze water drain plug 20 has changed from the drained state to the water supply state. However, the hot water supply terminal is opened, hot water supply is started, and the hot water supply flow rate sensor 22 is When a flow rate higher than the predetermined flow rate (for example, 15 pps or more) is detected, the water drain operation detecting means 29a detects that the antifreeze water drain plug 20 has changed from the drained state to the water supply state, and the three-way valve 5 May be switched to the intermediate side. By doing so, when hot water supply is resumed, the three-way valve 5 is returned to the state where the intermediate hot water discharge pipe 4 is communicated, so that hot water at an intermediate temperature in the hot water storage tank 1 can be discharged preferentially. When boiling at 16, the boiling operation can be performed in a state where the COP (heating efficiency) is good.

  Moreover, although the said predetermined pressure was 50 kPa, it is not limited to this, The said predetermined pressure may be set to 10 kPa or 0 kPa, and as above-mentioned, it is a draining state by the action | operation of the antifreezing water drain plug 20 A pressure value that can be considered or a pressure value that is smaller than the set pressure value 170 kPa of the feed water pressure reducing valve 17 and that is not detected in a normal use state may be set in advance as the predetermined pressure.

  Further, although the pressure sensor 18 is provided on the downstream side of the water supply pressure reducing valve 17, the pressure sensor 18 may be provided on the water supply pipe 2 between the water supply pressure reducing valve 17 and the antifreezing water drain plug 20 on the upstream side of the water supply pressure reducing valve 17. Even if it is disposed at this position, if the operation handle 20a of the antifreeze water drain plug 20 is open and drained, the position where the pressure sensor 18 is disposed is drained and the pressure sensor 18 is 0 kPa. If the operation handle 20a of the antifreeze water drain plug 20 is closed and water is supplied, the pressure sensor 18 detects the water supply pressure of city water. Based on the detected value to be detected, it is possible to detect a decrease or return of the feed water pressure.

  Further, although the three-way valve 5 has been described as a switching means for switching between the upper tap pipe 3 and the intermediate tap pipe 4, the ratio of the amount of hot water from the upper tap pipe 3 and the amount of hot water from the intermediate tap pipe 4 is determined. An adjustable mixing valve or an open / close valve provided in each of the upper hot water discharge pipe 3 and the intermediate hot water discharge pipe 4 may be used as a switching means, and when the antifreezing water drain plug 20 is drained, the intermediate hot water discharge pipe Any structure may be used as long as it can block 4 and communicate with the upper discharge pipe 3.

  In the present embodiment, the heating means 16 for heating the hot water in the hot water storage tank 1 has been described using a heat pump type. However, the heating means 16 is disposed in the hot water storage tank 1 and is provided in the hot water storage tank 1. An electric heater that heats the hot water may be used as long as the hot water in the hot water storage tank 1 can be heated.

Next, another embodiment of the present invention will be described. The same components as those of the previous embodiment are denoted by the same reference numerals and description thereof is omitted.
In this embodiment, the pressure sensor 18 is removed, and in the middle of the water supply pipe 2 downstream of the water supply pressure reducing valve 17, the water supply flow rate is detected by the number of rotations of the internal impeller and the water flow of the water supplied through the water supply pipe 2 is detected. A water supply flow rate sensor 30 is provided as water flow detecting means.

  Next, in the hot water storage type hot water supply apparatus shown in FIG. 3, the case where the antifreeze drain plug 20 is opened and drained by the user when there is a risk of freezing in winter will be described based on the flowchart shown in FIG.

  When the operation handle 20a of the antifreeze water drain plug 20 is operated by the user and the drainage operation is started, the water in the water supply pipe 2 and the hot water in the hot water pipe 8 are respectively connected to the drain outlet 20b of the antifreeze water drain plug 20. Air is introduced into the hot water storage tank 1 from the negative pressure intake valve 19 discharged from the hot water outlet 20 c and communicated with the upper part of the hot water storage tank 1.

  Along with this drainage operation, the hot water supply flow rate sensor 22 provided in the hot water supply pipe 8 detects a predetermined flow rate (for example, about 2 pps to 10 pps) lower than that during normal hot water supply (step S6), and the water supply flow rate sensor 30 Detects no water flow, that is, 0 pps indicating that water is not flowing and there is no flow rate (step S7), and when this state is continued for a certain time, the water draining operation detecting means 29a It is detected as drainage of the hot water supply pipe 8 by operation, and the three-way valve 5 is connected to the upper hot water discharge pipe 3 side and the intermediate hot water discharge pipe 4 side is closed (step S8). In step S6, the water supply flow rate sensor 30 detects that there is no water flow because the water supply upstream of the water supply pressure reducing valve 17 is drained by the draining operation of the antifreeze water drain plug 20, and the water supply pressure is applied to the hot water storage tank 1 side. This is because water does not flow from the water supply pipe 2 to the hot water storage tank 1 side.

  After the process of step S8 is completed, the operation handle 20a of the antifreeze water drain plug 20 is closed by the user to restart the water supply, the hot water supply terminal is opened, and the hot water supply is started. Detects a flow rate higher than the predetermined flow rate (for example, 15 pps or more) (step S9), the water drain operation detecting means 29a detects that the antifreeze water drain plug 20 has changed from a drained state to a water supply state, The three-way valve 5 is closed on the upper hot water discharge pipe 3 side, and the intermediate hot water discharge pipe 4 side is in communication (step S10).

  In this way, when drainage from the hot water supply pipe 8 is detected, the three-way valve 5 is closed on the intermediate hot water discharge pipe 4 side and communicated with the upper hot water discharge pipe 3 side. The air from the negative pressure intake valve 19 is introduced to the hot water drainage of the hot water storage tank 1 due to the siphon phenomenon, so that the hot water drainage from the hot water storage tank 1 can be minimized. It is possible to eliminate waste of energy by heating hot water.

  In addition, when hot water supply is resumed, the three-way valve 5 is returned to the state where the intermediate hot water discharge pipe 4 is communicated, so that hot water at an intermediate temperature in the hot water storage tank 1 can be preferentially discharged. When raising the temperature, the boiling operation can be performed in a state where the COP (heating efficiency) is good.

  Further, conventionally, the amount of hot water is reduced due to the removal of hot water in the hot water storage tank 1, and if the hot water supply is used as it is, there has been a shortage of hot water that has disappeared. Since no hot water can be removed, it is possible to prevent this hot water from occurring. Conventionally, since a large amount of air is contained in the hot water storage tank 1, it is necessary to remove this large amount of air before hot water supply, but this is also unnecessary.

  The present invention is not limited to the other embodiments described above. In this embodiment, the water flow rate sensor 30 that detects the flow rate of the feed water flowing through the water supply pipe 2 is used as the water flow detection means. As a means, a water flow switch that detects the presence or absence of the water flow of the feed water flowing through the feed water pipe 2 may be used.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Water supply pipe 3 Upper hot water discharge pipe 4 Intermediate hot water supply pipe 5 Three-way valve (switching means)
8 Hot water supply pipe 16 Heating means 18 Pressure sensor (feed water pressure detecting means)
20 Non-freezing water drain plug 22 Hot water flow rate sensor (hot water flow rate detection means)
29a Drainage operation detection means 30 Water supply flow rate sensor (water flow detection means)

Claims (4)

  A hot water storage tank for storing hot water, a heating means for heating the hot water in the hot water storage tank, a water supply pipe for supplying water to the lower part of the hot water storage tank, a water supply pressure detecting means for detecting the water supply pressure provided in the water supply pipe, and the hot water storage An upper tapping pipe for tapping from the upper part of the tank, an intermediate tapping pipe for tapping from the intermediate portion of the hot water storage tank, switching means for selecting one of the upper tapping pipe and the intermediate tapping pipe, and a tapping side of the switching means In a hot water storage type hot water supply apparatus provided with a connected hot water supply pipe and a hot water supply flow rate detection means provided in the hot water supply pipe, provided with a drain operation detecting means for detecting drainage of the hot water pipe due to the operation of an antifreeze drain plug The drainage detection means detects the operation of the antifreeze drain plug when the hot water flow rate detection means detects a predetermined flow rate and the feed water pressure detection means detects a predetermined pressure or less. Above switching means Communicates hot water pipe side, the hot-water storage type hot water supply apparatus is characterized in that so as to close the intermediate tapping pipe side.   A hot water storage tank for storing hot water, a heating means for heating the hot water in the hot water storage tank, a water supply pipe for supplying water to the lower part of the hot water storage tank, a water flow detection means for detecting a water flow provided in the water supply pipe, and an upper part of the hot water storage tank An upper discharge pipe for discharging from the hot water, an intermediate discharge pipe for discharging from the intermediate portion of the hot water storage tank, switching means for selecting one of the upper discharge pipe and the intermediate discharge pipe, and a discharge side of the switching means. In the hot water storage type hot water supply apparatus provided with the hot water supply pipe and the hot water flow rate detection means provided in the hot water supply pipe, there is provided a water drain operation detection means for detecting drainage of the hot water pipe due to the operation of the antifreeze water drain plug. When the hot water supply flow detecting means detects a predetermined flow rate and the water flow detecting means detects no water flow, the water draining operation detecting means detects the operation of the antifreeze water drain plug, and the switching means Tube side Through, hot water storage type hot water supply apparatus is characterized in that so as to close the intermediate tapping pipe side.   After the switching means is connected to the upper tapping pipe side and the intermediate tapping pipe side is closed by detecting the operation of the draining action detecting means, the draining action detecting means is detected by the feed water pressure detecting means. 2. The hot water storage type hot water supply apparatus according to claim 1, wherein when the return of the feed water pressure is detected based on the feed water pressure to be performed, the switching means is closed on the upper tapping pipe side and communicated with the intermediate tapping pipe side. .   When the switching means is connected to the upper tapping pipe side and the intermediate tapping pipe side is closed by detecting the operation of the draining action detecting means, and then the hot water supply flow rate detecting means detects a flow rate equal to or higher than a predetermined flow rate. The hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the switching means is closed on the upper hot water discharge pipe side and communicated with the intermediate hot water discharge pipe side.

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