JP4949818B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus, and more particularly, to a hot water supply apparatus including a hot water storage tank that enables immediate hot water supply.

  Conventionally, many hot water supply apparatuses using a heat pump have been proposed. Hot water storage water heaters using heat pumps are generally small for home use, but in recent years, they have also been adopted for commercial use in public baths and so-called spas (relaxation facilities centered on hot springs). Has been.

  In commercial hot water supply, immediate hot water supply is required. Therefore, for example, a circulation type hot water supply apparatus including a heat pump, a hot water storage tank that stores hot water heated by the heat pump, and a circulation channel that circulates between the hot water storage tank and the hot water supply unit is employed (for example, , See Patent Document 1).

  However, in the case of such a circulation type, the hot water in the circulation flow path is radiated while being circulated and the temperature is lowered, so that it is necessary to heat it and keep it in a predetermined temperature range.

  Therefore, in the hot water supply apparatus of Patent Document 1, a heat exchange unit for heating the hot water circulating through the circulation channel is disposed in the hot water storage tank. With this configuration, the hot water circulating through the circulation channel is heated by receiving heat supply from the hot water in the tank in the heat exchange unit.

  However, in the configuration of Patent Document 1, the heat exchange unit disposed in the hot water storage tank exchanges heat between the hot water in the hot water storage tank and the hot water constantly circulating in the circulation channel. In addition, in the configuration of Patent Document 1, it is extremely troublesome and complicated to adjust the flow rate of hot water or water flowing into the circulation flow path. There was a risk of increased costs.

  On the other hand, like the hot water supply apparatus shown in FIG. 9, it can be considered that a heating apparatus such as a temperature rising heater is provided in the circulation flow path to prevent a temperature drop.

  As shown in FIG. 9, such a hot water supply apparatus has a heat pump unit 200 connected in communication with a hot water storage tank 100 connected to the raw water supply passage 110 through a circulation channel 210 for hot water storage, and is heated by the heat pump unit 200. Hot water is stored in the hot water storage tank 100, and a hot water supply circulation path 400 in which various hot water discharge terminals 300 such as a faucet and a shower head are attached to the hot water supply path 120 connected in communication with the hot water storage tank 100. The hot water supply terminal 300 can supply hot water.

  In the figure, 410 is a circulation flow path pump, and 420 is a mixing valve. The hot water supply path 120 and the hot water supply circulation path 400 are connected to each other via the mixing valve 420. Then, raw water is allowed to flow into the circulation channel 400 through the mixing valve 420, and the hot water temperature in the circulation channel 400 is appropriately reduced to make it suitable for use.

In the conventional hot water supply apparatus having the above-described configuration, as shown in the drawing, in order to prevent a decrease in hot water temperature in the hot water supply circulation channel 400, an electric heater 500 as a heating device is provided in the middle of the circulation flow channel 400, The heat dissipation loss in the circulation channel 400 is heated using the electric heater 500.
JP 2005-30642 A

However, as has been described above, in the conventional commercial water heater using a heat pump, in order to prevent a decrease hot water temperature in the circulation flow path, in addition to the heat pump, comes the use of an electric heater shown in FIG. 9 However, instead of adjusting the flow rate, the running cost is remarkably increased.

  In particular, since the cost reduction of a hot water supply apparatus used for business use is a major issue, a hot water supply apparatus that is advantageous in terms of both initial cost and running cost of the entire apparatus is desired from the market.

  An object of the present invention is to provide a hot water supply apparatus that can solve the above-described problems.

( 1 ) In the present invention, a heat pump is connected in communication with a hot water storage tank connected to the raw water supply path through a hot water storage circulation channel, and hot water heated by the heat pump is stored in the hot water storage tank. In a hot water supply apparatus in which a circulating hot water supply circuit having a hot water terminal attached is connected to a hot water supply path that is connected to the tank so that hot water can be supplied from the hot water terminal, the hot water supply path and the circulating hot water circuit are communicated via a mixing valve. A sub-tank that temporarily stores hot water is provided in the middle of the hot water return path that is connected to and connected to the bottom side of the hot water tank by branching from the middle of the circulating hot water supply circuit. The hot water stored in the hot water storage tank is made to flow into the circulating hot water supply circuit by the amount of returned hot water that has flowed from the hot water supply device, and the hot water in the circulating hot water supply circuit can be maintained within a predetermined temperature range.

( 2 ) Further, the present invention is characterized in that, in the hot water supply apparatus according to (1), a heater using fuel is connected to the hot water storage tank via an auxiliary circulation channel for hot water storage.

  According to the present invention, it is not necessary to provide other dedicated heat source equipment for preventing a decrease in hot water temperature in the hot water circulation circuit, and the flow path configuration is simple and the flow rate can be easily adjusted. Therefore, increase in initial cost and running cost can be prevented, and low-cost equipment becomes possible.

  In addition, when a heater using fuel is connected to a hot water storage tank via an auxiliary circulation channel for hot water storage, a heat pump that uses low-cost night electricity and a heater that uses fuel that can supply a large volume of hot water It is possible to provide a hot water supply apparatus that takes advantage of both advantages.

  The hot water supply apparatus according to the present embodiment is connected to a hot water storage tank connected in communication with the raw water supply path via a hot water circulation channel, and stores hot water heated by the heat pump in the hot water storage tank. In a hot water supply apparatus in which a hot water supply circuit connected to the hot water storage tank is connected to a circulating hot water supply circuit attached with a hot water discharge terminal, and hot water can be supplied from the hot water discharge terminal, the hot water supply path and the circulating hot water supply circuit are connected via a mixing valve. In addition, the hot water supply path is branched from the middle of the circulating hot water supply circuit and connected to the hot water storage tank, and the amount of water flowing from the hot water return path into the hot water storage tank is stored in the hot water storage tank. Hot water is allowed to flow into the circulating hot water supply circuit so that the hot water in the circulating hot water supply circuit can be maintained within a predetermined temperature range.

  The heat pump is a system that is more efficient than a heating device such as a boiler that burns and heats fossil fuel, and has a low environmental load, and an energy saving effect can be expected. That is, according to the heat pump, high-temperature hot water can be stored using cheap nighttime electric power, and circulating hot water is supplied at a temperature lower than the hot water temperature using the heat stored and stored, thereby reducing running costs. It is possible to provide a hot water supply device that can achieve the above.

  Then, the hot water stored in the hot water storage tank is allowed to flow into the circulating hot water supply circuit, and the hot water in the circulating hot water supply circuit can be kept in a predetermined temperature range. There is no need to provide other dedicated heat source equipment to prevent the deterioration. Therefore, the initial cost and running cost of the dedicated heat source device are prevented from increasing, and maintenance costs are not required. Therefore, the cost is reduced, and the installation space for the dedicated heat source device does not need to be considered. At the same time, the degree of design freedom for the equipment is improved.

  The hot water storage circulation flow path has a start end connected to the bottom of the hot water storage tank, a terminal end connected to the heat pump, a start pipe connected to the heat pump, and a terminal end connected to the ceiling of the hot water tank. What is necessary is just to set it as the structure provided with the pouring pipe connected to the part in communication.

  An upper cylindrical shape that once receives the hot water flowing from the hot water circulation passage and the hot water flowing from the return hot water passage to the ceiling side in the hot water storage tank and guides it to the ceiling side in the hot water storage tank while decelerating. A configuration in which a rectifying member is provided and a lower cylindrical rectifying member is provided on the bottom side of the hot water storage tank, which once receives water flowing from the raw water supply path and guides it to the bottom side of the hot water storage tank while decelerating. It is good to do.

  That is, since the upper cylindrical rectifying member and the lower cylindrical rectifying member are provided in the hot water storage tank, it is possible to prevent stirring and convection from occurring in the hot water storage tank as much as possible. The hot water that is heated up to and injected through the hot water storage circulation channel is stored in such a manner that it is sequentially stacked from the ceiling to the bottom of the hot water tank, that is, while maintaining the interface with the raw water.

  In addition, the hot water is supplied from the raw water supply path to the inside of the hot water tank, and the hot water tank is always filled, but the added raw water is stirred in the hot water tank by the lower cylindrical rectifying member.・ In order to prevent convection as much as possible, it stays at the bottom of the hot water tank, and the interface between the hot water and raw water remains undisturbed. Although hot water and raw water are stored in layers, heat is exchanged between high temperature hot water and raw water, so a small but medium temperature layer is also formed between high temperature hot water and raw water. Become.

  In the hot water storage tank according to the present embodiment, as described above, when hot water is stored by heating with a heat pump using nighttime electric power, the low-temperature raw water circulates in the hot water circulation flow path to become hot water in the hot water storage tank. Therefore, most of the area in the hot water tank can be used as hot water, and a large amount of hot water having an effective temperature can be stored in the hot water tank having the same volume as the conventional one.

  Therefore, even when the hot water supply facility of the present embodiment is applied to the spa described above and used for business purposes, a hot water storage tank having a smaller capacity can be used, and the cost of parts required for the hot water storage tank is reduced. It can be installed in a narrower installation space.

  By the way, the cross-sectional area of the flow path in the upper cylindrical rectifying member is larger than the cross-sectional area of the pouring port provided in the hot water storage tank and communicating with the pouring channel, and the flow path in the lower cylindrical rectifying member It is desirable that the cross-sectional area is larger than the cross-sectional area of the water supply port provided in the hot water storage tank and communicating with the raw water supply path.

  With this configuration, the hot water poured into the hot water storage tank from the pouring port is reduced in flow rate when it flows into the upper cylindrical rectifying member, and is led to the ceiling in the hot water tank as a gentle flow. When the raw water supplied from the water supply port flows into the lower cylindrical rectifying member, the flow velocity thereof is reduced, and the raw water is led to the bottom of the hot water tank in a gentle flow. Therefore, it can suppress more effectively that stirring and a convection arise in a hot water storage tank, and the boundary between high temperature hot water and low temperature water becomes difficult to be disturbed.

  Furthermore, the hot water supply apparatus according to the present embodiment is provided with a plurality of the above-described circulating hot water supply circuits, and can also discharge hot water to different hot water supply locations at different circulating hot water supply temperatures. Therefore, it is suitable for relaxation facilities where bathing facilities such as spas are enhanced.

  In addition, the mixing valve interposed between the hot water supply path and the circulating hot water supply circuit may be connected to the end of the branch supply path branched from the raw water supply path.

  That is, the hot water in the hot water storage tank heated and stored by the heat pump is high temperature (for example, about 90 ° C.), and the hot water required for tapping is about 40 ° C. for bathing, for example. The hot water in the hot water supply circuit may be maintained at a predetermined temperature of about 65 ° C. Then, mass consumption of the hot water in a hot water storage tank can be suppressed by mixing low temperature raw | natural water in a circulating hot-water supply circuit and using it by making it into predetermined temperature.

  Further, in order to keep the hot water in the circulating hot water supply circuit in a predetermined temperature range, a temperature detector for detecting the temperature in the circulating hot water supply circuit, and the temperature of the mixing valve based on the temperature detected by the temperature detector. It is desirable to have a configuration including a controller that controls the valve opening. In other words, the hot water temperature in the circulating hot water supply circuit is automatically kept substantially constant by the controller.

  Further, as another embodiment of the hot water supply apparatus, the circulating hot water supply circuit and the return hot water passage can be connected to each other via a three-way valve. At this time, the opening degree of the three-way valve may be automatically controlled by the controller.

  Furthermore, other forms of controlling the amount of hot water returned from the hot water return path to the hot water storage tank include, for example, an electromagnetic valve provided in the hot water return path for ON-OFF control, or a flow rate adjusting valve provided in the hot water return path. It is conceivable that the flow rate adjustment is automatically controlled, or that a manual valve is provided in the hot water return path to adjust to a certain amount.

  As still another embodiment of the hot water supply apparatus, a heater using fuel can be connected to the hot water storage tank via an auxiliary circulation channel for hot water storage.

  In other words, in addition to the heat pump, for example, an atmospheric pressure heater (pressureless heater) can be used. With such a heater, a large amount of hot water can be filled in the hot water tank in a short time, and a large amount of hot water is consumed. It is possible to cope with the case where a power failure occurs.

  As described above, according to the present embodiment, the running cost can be reduced with the heat pump, and the lack of capability at low temperatures and the fear of running out of hot water can be solved, which is suitable for business use.

  Further, in the case of a heat pump, it is difficult to heat from a medium temperature to a high temperature, such as raising the temperature of hot water in a bathtub, but it can be easily handled by using an atmospheric pressure heater.

  Here, the atmospheric pressure heater (pressureless heater) means that a can body is opened to the atmosphere, a circulation passage for circulating can water is provided in the can body, and a heating device is provided in the middle of the circulation passage. In this embodiment, a decompression boiler (vacuum heater) and the like are included. Since these do not in principle exceed 100 ° C. and do not exceed atmospheric pressure, they do not require special handling qualifications such as general boilers. Such an atmospheric pressure heater is described in detail, for example, in Japanese Patent Application Laid-Open No. 2002-267266 filed and published by the present applicant.

  Furthermore, as another embodiment of the hot water supply apparatus for making both the initial cost and the running cost of the entire apparatus advantageous, the following configuration can be adopted.

  That is, a heat pump is connected to a hot water tank connected to the raw water supply path via a hot water circulation channel, and hot water heated by the heat pump is stored in the hot water tank and is connected to the hot water tank. In a hot water supply apparatus that allows a hot water supply circuit to communicate with a circulating hot water supply circuit having a hot water supply terminal attached thereto, and enables hot water supply from the hot water discharge terminal, the hot water supply path and the circulating hot water supply circuit are connected to each other via a mixing valve, and A sub-tank for temporarily storing the hot water is provided in the middle of the hot water path branched from the middle of the circulating hot water circuit and connected to the bottom side of the hot water storage tank, and the hot water flowing into the sub tank from the circulating hot water circuit. Accordingly, the hot water stored in the hot water storage tank is allowed to flow into the circulating hot water supply circuit so that the hot water in the circulating hot water supply circuit can be maintained within a predetermined temperature range.

  With such a configuration, the hot water whose temperature has decreased in the circulating hot water supply circuit due to heat dissipation or the like does not directly return to the hot water storage tank, but is temporarily stored in the sub tank, and the medium hot water flowing into the sub tank from the circulating hot water supply circuit. Therefore, hot water is sent from the hot water storage tank to the circulating hot water supply circuit, and is kept warm, for example, as circulating hot water at about 65 ° C.

  That is, since the hot water stored in the hot water tank is not directly mixed with the hot water from the circulating hot water supply circuit, the hot water and the hot water are mixed and the medium temperature region is occupied by the hot water. An increase in the ratio can be prevented.

  Therefore, it is not affected by the temperature of hot water usage or heat radiation load, and the amount of heat stored by hot water can be secured in the hot water tank, and the hot water tank capacity can be fully utilized while reliably supplying the hot water volume circulation hot water supply circuit. It becomes possible to supply hot water. In addition, when heating with a heat pump, COP (Coefficient Of Performance) decreases due to the characteristics of the water temperature, but by providing a sub tank, the production of medium temperature hot water in the hot water tank is prevented, and as a result COP It is possible to prevent a decrease in the above.

  The configuration of the sub tank is not particularly limited as long as it has a necessary volume. The necessary volume may be determined in consideration of a hot water supply load, a heat radiation load, a hot water supply pattern, and the like, but normally it may be about 10 to 20% with respect to the volume of the hot water tank. In addition, the above-described cylindrical rectifying member can be provided in the sub tank as necessary.

Hereinafter, an embodiment of a hot water supply apparatus according to the present invention will be described more specifically based on the drawings.
(First embodiment)
FIG. 1 is a schematic explanatory view showing a configuration of a hot water supply apparatus according to the first embodiment, and FIG. 2 is an explanatory view showing an outline of an internal structure of a hot water storage tank 1 provided by the hot water supply apparatus according to this embodiment.

  In FIG. 1, reference numeral 1 denotes a hot water storage tank, which includes a bowl-shaped tank body 10 sealed with a ceiling part 10b and a bottom part 10c in which the upper and lower ends of a cylindrical body part 10a are curved outward. Although schematically shown in FIG. 1, the bottom portion 10c is provided with a plurality of legs, and the hot water tank 1 is arranged upright.

  Further, a water supply pipe 50 which is a raw water supply path for supplying raw water such as tap water is connected to a position near the bottom 10c of the main body 10a, and the raw water is pressurized from the water supply pipe 50 into the hot water tank 1. Supplied. Thereby, the inside of the hot water tank 1 is maintained in a pressurized state.

  The bottom 10c of the hot water tank 1 is connected to the start end of a water intake pipe 53 that takes water in order to raise the temperature of the stored water in the hot water tank 1, and the end of the water intake pipe 53 is the inlet of the heat pump unit 40. It is linked to. Further, the heat pump unit 40 is provided with a water outlet for discharging hot water heated and heated, and this water outlet is connected to a start end of a pouring pipe 54 for injecting hot water into the hot water tank 1. The end of the hot water pipe 54 communicates with the ceiling portion 10 b of the hot water tank 1. That is, a hot water supply pipe 51 serving as a hot water supply path for supplying hot water stored in the hot water storage tank 1 to a place of use is connected to the center of the ceiling portion 10 b of the hot water storage tank 1. The ends of the pipe 54 are connected in communication. Note that the hot water supply pipe 51 and the pouring pipe 54 may be independently connected to the hot water tank 1.

  The heat pump unit 40 includes a well-known heat pump and a hot water storage circulation pump. The hot pump circulation, which heats and raises the temperature of the stored water in the hot water tank 1 by the heat pump unit 40, the water intake pipe 53, and the pouring pipe 54. A flow path is formed. Therefore, for example, in the middle of the night, while there is no need to supply hot water, the water in the hot water tank 1 circulates in the hot water tank 1 → the intake pipe 53 → the heat pump unit 40 → the hot water pipe 54 → the hot water pipe 51 → the hot water tank 1. However, it can be stored as hot water up to about 90 ° C. by cheap late-night power.

  The hot water supply pipe 51 connected to the center of the ceiling portion 10b of the hot water storage tank 1 is connected to a circulating hot water supply pipe 30 through a mixing valve 2 composed of an electromagnetic valve or the like to constitute a circulating hot water supply circuit 3. The circulating hot water pipe 30 is connected to various hot water terminals 4 such as a faucet and a shower head, and hot water in the hot water tank 1 is discharged into the hot water pipe 51 by the internal pressure of the hot water tank 1. It will be supplied to the circulating hot water supply pipe 30 via the mixing valve 2.

  By the way, the mixing valve 2 is also connected to the end of a branch water supply pipe 52 that is connected to the water supply pipe 50 described above. By mixing the high temperature hot water and the raw water that is cold water through the mixing valve 2, the mixing valve 2 circulates. The hot water supply circuit 3 is always filled with hot water in a temperature range of 60 to 70 ° C., for example. The mixing valve 2 can control the inflow amount from the hot water supply pipe 51 to the circulating hot water supply pipe 30 and the inflow amount of raw water from the branch water supply pipe 52 by valve driving.

  As shown in FIG. 1, the circulating hot water supply circuit 3 is provided with a circulating hot water supply circuit pump 31, and the circulating hot water supply circuit 3 is driven to drive hot water in the circulating hot water supply circuit 3. 3 can be circulated. Therefore, it is possible to supply hot water immediately in response to a request from the hot water terminal 4. Although not shown in the drawings, the hot water terminal 4 is provided with a hot water mixing mechanism capable of taking raw water into the intake channel inside the hot water terminal 4, and the user can take hot water at a desired temperature at any time.

  In the configuration described above, the characteristic configuration in the present embodiment is that the hot water supply pipe 51 and the circulating hot water pipe 30 are connected to each other via the mixing valve 2, and from the middle of the circulating hot water pipe 30. A hot water pipe 32 that serves as a hot water return path is branched and connected to the hot water tank 1, and the hot water stored in the hot water tank 1 is circulated through the hot water tank as much as it flows into the hot water tank 1 from the hot water pipe 32. The hot water in the circulating hot water supply circuit 3 can be maintained in the temperature range of 60 to 70 ° C. described above.

  That is, the hot water in the circulating hot water supply circuit 3 is obtained by mixing raw water with hot water (for example, 90 ° C.) in the hot water tank 1 to obtain hot water of a predetermined temperature. is there. And, as shown in the figure, the hot water in the circulating hot water supply circuit 3 was circulated because the hot water pipe 32 which is a hot water return path was branched from the middle of the circulating hot water supply pipe 30 and connected to the hot water storage tank 1. In some cases, a part of the hot water can be returned to the hot water tank 1, and unless the mixing valve 2 that connects the hot water supply pipe 51 and the circulating hot water supply pipe 30 is closed, the amount of returned hot water is determined. The amount of hot water in the hot water storage tank 1 can be made to flow into the circulating hot water supply pipe 30.

  Therefore, even if the temperature of the hot water in the circulating hot water supply circuit 3 is lowered due to heat dissipation or the like, it is possible to raise the temperature without providing a separate dedicated heating device.

  In this embodiment, the temperature detector 6 that detects the temperature in the circulating hot water supply circuit 3 and the controller 7 that controls the valve opening of the mixing valve 2 based on the temperature detected by the temperature detector 6. It is set as the structure provided.

  That is, as shown in the figure, the temperature detector 6 is disposed at a predetermined location of the circulating hot water supply pipe 30, and the temperature detector 6 and the controller 7 are electrically connected to each other. While detecting the hot water temperature in the hot water supply circuit 3, the controller 7 executes drive control of the mixing valve 2 based on the detected temperature, the return flow rate from the hot water return pipe 32 into the hot water storage tank 1, It is possible to continuously control the ratio of the recirculation amount in the circulating hot water supply circuit 3 to keep it within a predetermined temperature range.

  For example, when the hot water temperature detected by the temperature detector 6 becomes 60 ° C. or less, the controller 7 increases the return flow rate from the hot water return pipe 32 to the hot water tank 1, and accordingly, in the hot water tank 1. As the amount of hot water flowing into the circulating hot water supply pipe 30 increases, the hot water temperature in the circulating hot water supply circuit 3 rises. At this time, in the hot water tank 1, high-temperature hot water is supplied to the circulating hot water supply circuit 3 and decreases, so the temperature in the hot water tank 1 gradually decreases, but the temperature is the set temperature of the circulating hot water circuit 3. As long as a state higher than (60 to 70 ° C.) is maintained, the hot water in the circulating hot water supply circuit 3 can be heated and the set temperature can be maintained.

  Further, as shown in FIG. 2, the hot water storage tank 1 according to the present embodiment once receives hot water flowing in from the pouring pipe 54 and hot water flowing in from the hot water returning pipe 32 on the ceiling portion 10b side. An upper cylindrical rectifying member 8 that leads to the ceiling 10b side in the hot water tank 1 while being decelerated is disposed, and the water 10 flowing in from the water supply pipe 50 is once received on the bottom 10c side of the hot water tank 1 and decelerated. A lower cylindrical rectifying member 9 is disposed to guide the bottom 10c of the hot water tank 1 to the bottom 10c side.

  The upper and lower cylindrical rectifying members 8 and 9 are each formed in a bottomed cylindrical shape, with their openings directed to the ceiling portion 10b and the bottom portion 10c, respectively, and their central axes substantially coincide with the central axis of the hot water tank 1 Are arranged. Note that gaps of appropriate dimensions are formed between the opening end of the upper cylindrical rectifying member 8 and the inner surface of the ceiling portion 10b and between the opening end of the lower cylindrical rectifying member 9 and the inner surface of the bottom portion 10c. is there.

  And the 1st penetration pipe 81 which has a diameter smaller than the diameter of the upper side cylindrical rectification member 8 in the position near the ceiling part 10b in the main-body part 10a of the hot water storage tank 1, and also the bottom part (hot water storage) of the lower side cylindrical rectification member 9 A second through pipe 91 having a smaller diameter than that of the lower cylindrical rectifying member 9 is installed in the vicinity of the surface of the tank 1 on the ceiling 10b side, and is attached to the first through pipe 81. The water supply pipe 50 is connected in communication with the second through pipe 91.

  In addition, the tip portions of the first and second through pipes 81 and 91 are obliquely cut and penetrate the peripheral surfaces near the bottoms of the upper and lower cylindrical rectifying members 8 and 9, respectively. The hot water in the circulating hot water supply circuit 3 discharged from 81 collides with the peripheral surface of the upper cylindrical rectifying member 8 and then gradually rises. On the other hand, the raw water discharged from the second through pipe 91 falls gently after colliding with the peripheral surface of the lower cylindrical rectifying member 9. Therefore, cold raw water is stored in layers on the bottom 10c side of the hot water tank 1 without mixing the raw water and other hot water with stirring.

  Moreover, the hot water from the pouring pipe 54 flowing in from the ceiling portion 10b of the hot water tank 1 once flows into the upper cylindrical rectifying member 8 from the upper opening, collides with the bottom, and then rises gently. It moves into the hot water tank 1. Then, the hot water flowing into the upper cylindrical rectifying member 8 from the first through pipe 81 is mixed and raised in the upper cylindrical rectifying member 8 and stirred and mixed with other hot water in the hot water tank 1. However, it is stored in a layered manner on the ceiling 10b side of the hot water tank 1.

  In particular, in the present embodiment, the diameter of the upper cylindrical rectifying member 8 is set such that the flow rate of the upper cylindrical rectifying member 8 is about 1/4 to 1/10 of the flow rate of the first through pipe 81. . Therefore, the flow rate of the hot water discharged from the first through pipe 81 is reduced, rises more gently while being sufficiently mixed with the high temperature hot water from the pouring pipe 54, and is stored in the hot water storage tank from the opening of the upper cylindrical rectifying member 8. 1 is prevented from occurring in the hot water storage tank 1 as much as possible, and mixed hot water from the circulating hot water supply circuit 3 and the hot water is supplied to the hot water storage tank 1. From the ceiling 10b to the bottom 10c, they are stored in a stacked manner.

  On the other hand, also for the diameter of the lower cylindrical rectifying member 9, the flow rate of the lower cylindrical rectifying member 9 is set to be about ¼ to 1/10 of the flow rate of the second through pipe 91. The raw water will gently flow into the lower cylindrical rectifying member 9 and the generation of convection will be further suppressed, and the state of maintaining the interface between hot water and water relatively can be maintained. it can.

  Since the hot water storage tank 1 in the present embodiment is configured as described above, when a part of the hot water in the circulating hot water supply circuit 3 is returned to the hot water storage tank 1, the returned hot water is returned to the hot water return pipe 32 → first. Through the through pipe 81 → the upper cylindrical rectifying member 8, the hot water from the hot water supply pipe 51 is mixed. As described above, the hot water returned from the circulating hot water supply circuit 3 and the high-temperature hot water pass through the upper tubular rectifying member 8 and are stored in layers in the hot water tank 1. The hot water layer corresponding to the formed temperature is not disturbed, for example, convection or stirring phenomenon occurs, and the hot water temperature is lowered by rapidly mixing with the low temperature water stored in the lower part of the hot water tank 1. There is no fear of doing so. Therefore, relatively high-temperature hot water can be constantly supplied to the circulating hot water supply circuit 3, so that efficient hot water supply can be performed as a hot water supply device.

(First modification)
FIG. 3 is an explanatory diagram of a hot water supply apparatus according to a first modification. The present embodiment is different from the first embodiment in that the circulating hot water supply circuit 3 and the hot water return pipe 32 are connected in communication via a three-way valve 2 ′.

  In this modification, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted. Although not shown in the figure, it is assumed that upper and lower cylindrical rectifying members 8 and 9 are disposed in the hot water tank 1 as in the first embodiment.

  As shown in the figure, the three-way valve 2 'is configured such that valve drive control is performed by a controller 7' electrically connected to a temperature detector 6 that detects the temperature in the circulating hot water supply circuit 3. Based on the temperature detected by the detector 6, the valve of the three-way valve 2 'is driven.

  According to this modification, the amount of hot water returned from the hot water return pipe 32 into the hot water tank 1, that is, the amount of hot water flowing into the circulating hot water supply circuit 3 from the hot water tank 1 can be precisely controlled. In addition, the control for maintaining the hot water temperature in the circulating hot water supply circuit 3 within a predetermined range can be performed more accurately.

(Second modification)
FIG. 4 is an explanatory diagram of a hot water supply apparatus according to a second modification. In this modification, the difference from the first embodiment described above is that a pressureless heater 41 using fuel is connected to the hot water storage tank 1 through an auxiliary circulation channel for hot water storage. Here, the illustrated non-pressure heater 41 includes a decompression boiler (vacuum heater), and as the fuel, for example, fossil fuels such as kerosene and heavy oil can be used.

  In this modification, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Although not shown, it is assumed that the upper and lower cylindrical rectifying members 8 and 9 are disposed inside the hot water tank 1 as in the first and second embodiments.

  That is, as shown in the figure, the start end of an emergency intake pipe 42 for taking in the stored water in the hot water tank 1 is connected to the bottom 10c side of the main body 10a of the hot water tank 1, and the end of the emergency intake pipe 42 is connected. Is connected to the water inlet of the pressureless heater 41. Further, the pressureless heater 41 is provided with a hot water outlet for pouring hot water that has been heated and heated, and to this hot water outlet, a starting end of an auxiliary pouring pipe 45 for injecting hot water into the hot water tank 1 is connected, The terminal end of the auxiliary pouring pipe 45 is connected in communication with the ceiling 10b side of the main body 10a of the hot water tank 1.

  Further, a flow path switching valve 43 is attached in the middle of the emergency water intake pipe 42, and the flow path switching valve 43 is located at the upper end of the hot water storage tank 1 at the lower position of the auxiliary pouring pipe 45. The tip of the auxiliary intake pipe 44 that is connected in communication is connected in communication.

  46 is a circulation pump provided on the downstream side of the flow path switching valve 43 of the emergency water intake pipe 42. When the circulation pump 46 is driven, the flow path switching by the flow path switching valve 43 causes the inside of the hot water storage tank 1 to Hot water is stored in the hot water storage tank 1 → the emergency water intake pipe 42 → the pressureless heater 41 → the auxiliary hot water supply pipe 45 → the hot water storage tank 1 and the emergency auxiliary circulation channel, and the hot water storage tank 1 → the auxiliary water intake pipe 44 → the pressureless heater 41 → The auxiliary pouring pipe 45 → the hot water storage tank 1 and the normal auxiliary circulation channel that flows are formed.

  The emergency auxiliary circulation channel is applied, for example, when storing the entire amount of hot water in the event of an emergency when the heat pump unit 40 fails or during maintenance, and the raw water supplied from the water supply pipe 50 is heated to a high temperature. It can be heated to store hot water in a short time.

  On the other hand, the normal auxiliary circulation flow path is applied when securing a shortage of hot water in the upper part of the hot water tank 1 when the amount of hot water supply is remarkably increased (for example, in the winter or busy season for business use). Yes, it is possible to prevent running out of hot water.

  As described above, in the present embodiment, hot water is normally stored in the heat pump unit 40 using cheap nighttime electric power, and when the amount of hot water supply is remarkably increased, the non-pressure heater 41 is used as an auxiliary to ensure the amount of hot water. In the event of an emergency such as failure of the heat pump unit 40, hot water can be stored using the non-pressure heater 41, which is suitable for business use such as public baths and spas.

  By the way, the emergency water intake pipe 42 is communicated with the inside of the lower cylindrical rectifying member 9 through a penetration pipe similar to the second penetration pipe 91 described in the first embodiment, for example, and the auxiliary pouring pipe 45. Can be configured to communicate with the inside of the upper cylindrical rectifying member 8 through a through-tube similar to the first through-tube 81. With this configuration, even when the pressureless heater 41 is used, the hot water storage tank Since stirring and convection in 1 can be prevented as much as possible, efficient hot water can be stored.

  From the embodiment described above, the following hot water supply apparatus is realized.

  A hot water storage tank 1 communicated with a raw water supply path (for example, a water supply pipe 50) is connected to a hot water storage circulation path (for example, a water intake pipe 53, a pouring pipe 54, and a hot water supply pipe 51, and the hot water tank 1 → the water intake pipe 53 → A heat pump (for example, a heat pump unit 40) is connected in communication via a heat pump unit 40, a pouring pipe 54, a hot water supply pipe 51, a hot water tank 1, and a hot water tank 1, and the hot water heated by the heat pump is stored in the hot water tank 1. And a circulating hot water supply circuit 3 having a hot water supply terminal 4 (for example, a faucet or a shower head) attached to the hot water supply path (for example, a hot water supply pipe 51) connected to the hot water storage tank 1 in communication with the hot water storage tank 1. In the hot water supply apparatus that can supply hot water from the terminal 4, the hot water supply path and the circulating hot water supply circuit are connected to each other via the mixing valve 2, and a return hot water path (for example, a return hot water) is provided in the middle of the circulating hot water supply circuit 3. 32) is branched and connected to the hot water storage tank 1 so that hot water (hot water) stored in the hot water storage tank 1 is supplied to the circulating hot water supply circuit 3 by the amount that flows into the hot water storage tank 1 from the return hot water passage. A hot water supply apparatus that can flow into the hot water in the circulating hot water supply circuit 3 and keep the hot water in a predetermined temperature range (for example, 65 to 70 ° C.).

  The hot water flowing in from the hot water circulation channel and the hot water flowing in from the hot water return channel are once received on the ceiling 10b side in the hot water tank 1 and then decelerated to the ceiling 10b side in the hot water tank 1. An upper cylindrical flow straightening member 8 is provided, and the bottom cylinder 10c of the hot water storage tank 1 receives water flowing in from the raw water supply path and temporarily guides it to the bottom side of the hot water storage tank 1 while decelerating. Water heater provided with a flow straightening member 9.

  The hot water supply apparatus which connected to the said mixing valve 2 the terminal of the branch supply path (branch water supply pipe | tube 52) branched from the said raw | natural water supply path.

  A hot water supply apparatus in which the circulating hot water supply circuit 3 and the hot water return pipe 32 are connected in communication via a three-way valve 2 '.

  The cross-sectional area of the flow path in the upper cylindrical rectifying member 8 is larger than the cross-sectional area of the pouring port provided in the hot water storage tank 1 and communicating with the pouring channel, and the flow in the lower cylindrical rectifying member 9 is A hot water supply apparatus having a cross-sectional area larger than a cross-sectional area of a water supply port provided in the hot water storage tank 1 and communicating with the raw water supply path.

  A water heater comprising a temperature detector 6 for detecting the temperature in the circulating hot water supply circuit 3 and a controller 7 for controlling the valve opening of the mixing valve 2 based on the temperature detected by the temperature detector 6. .

  In the hot water storage tank 1, an auxiliary circulation flow path for hot water storage (for example, an emergency auxiliary circulation flow path including an emergency water intake pipe 42 and an auxiliary pouring pipe 45, a normal auxiliary circulation flow including an auxiliary water intake pipe 44, and an auxiliary pouring pipe 45. A hot water supply apparatus in which a heater (for example, a non-pressure heater 41) using fuel is connected in communication via a channel. Note that the non-pressure heater 41 exemplified as the heater using fuel includes a decompression boiler (vacuum heater).

(Second Embodiment)
Hereinafter, a hot water supply apparatus according to a second embodiment of the present invention will be described with reference to FIGS. In addition, the code | symbol used for description of this 2nd Embodiment uses the same code | symbol about the same component as 1st Embodiment, The description may be abbreviate | omitted. FIG. 5 is a schematic explanatory view showing the configuration of the hot water supply apparatus according to the second embodiment, and FIGS. 6 and 7 are graphs showing the results of simulating the transition of the remaining hot water amount and the remaining hot water temperature in the hot water tank.

  As shown in FIG. 5, the hot water tank 1 used in the present embodiment has the same configuration as that of the first embodiment, and has a ceiling portion 10b and a bottom portion in which the upper and lower ends of the cylindrical main body portion 10a are curved outward. A bowl-shaped tank body 10 sealed with 10c is provided. Of course, the hot water storage tank 1 may be a horizontal type.

  And the water supply pipe | tube 50 which is a raw | natural water supply path is connected with the bottom part 10c of the main-body part 10a of the hot water storage tank 1, raw water is pressurized and supplied in the hot water storage tank 1 from this water supply pipe 50, and the inside of the hot water storage tank 1 is pressurized. Maintained in a state.

  In addition, the bottom end 10 c of the hot water tank 1 is connected to the start end of a water intake pipe 53 that takes water to raise the temperature of the stored water in the hot water tank 1, and the end is connected to the water inlet of the heat pump unit 40. Further, the heat pump unit 40 is provided with a water outlet for discharging hot water heated and heated, and this water outlet is connected to a start end of a pouring pipe 54 for injecting hot water into the hot water tank 1. The end of the hot water pipe 54 communicates with the ceiling portion 10 b of the hot water tank 1. That is, a hot water supply pipe 51 serving as a hot water supply path for supplying hot water stored in the hot water storage tank 1 to a place of use is connected to the center of the ceiling portion 10 b of the hot water storage tank 1. The ends of the pipe 54 are connected in communication. Note that the hot water supply pipe 51 and the pouring pipe 54 may be independently connected to the hot water tank 1.

  The heat pump unit 40 has the same configuration as that of the first embodiment, and the water in the hot water storage tank 1 is stored in the hot water storage tank 1 → the intake pipe 53 → the heat pump unit 40 → while it is not necessary to supply hot water at midnight or the like. Hot water is stored as hot water up to about 90 ° C. by inexpensive late-night power while circulating through the hot water supply pipe 51 → the hot water supply pipe 51 → the hot water tank 1 and the hot water storage circulation channel.

  The hot water supply pipe 51 connected to the center of the ceiling portion 10b of the hot water tank 1 is connected to a circulating hot water supply pipe 30 through a thermo valve 20 serving as a mixing valve to constitute a circulating hot water supply circuit 3. The circulating hot water pipe 30 is connected to various hot water terminals 4 such as a faucet and a shower head, and hot water in the hot water tank 1 is discharged into the hot water pipe 51 by the internal pressure of the hot water tank 1. It will be supplied to the circulating hot water supply pipe 30 via the thermo valve 20.

  In this configuration, the present embodiment is characterized in that the return hot water is temporarily placed in the middle of the return hot water pipe 33 branched from the middle of the circulating hot water supply circuit 3 and connected to the bottom 10c side of the hot water storage tank 1. The sub-tank 34 is stored in the hot water tank 1 and the hot water stored in the hot water storage tank 1 is caused to flow into the sub-tank 34 by the amount of returned hot water flowing from the circulating hot water supply circuit 3. The hot water in 3 can be kept in a predetermined temperature range.

  That is, in the hot water supply apparatus according to the first embodiment described above, it is necessary to provide the circulating hot water supply circuit 3 with other dedicated heat source devices for preventing a decrease in the hot water temperature in the circulating hot water supply circuit 3. In addition, since the initial cost and running cost are prevented from increasing and maintenance costs are not required, low-cost facilities are possible, but medium-temperature hot water from the circulating hot water supply circuit 3 flows directly into the hot water tank 1. Therefore, depending on the use conditions, a lot of medium temperature regions are formed in the hot water storage tank 1, and it becomes difficult to make the temperature high due to the characteristics of the heat pump. As a result, the amount of heat storage (hot water storage efficiency) is reduced. There was a fear.

Here, the characteristics of the heat pump will be briefly described. The heat pump normally uses a CO ₂ refrigerant, which is heated from a low temperature (for example, 20 ° C. or less) to a high temperature (for example, 90 ° C.) on the refrigerant cycle. Although possible, warming from medium temperatures (eg, 50-65 degrees) to high temperatures is considered extremely inefficient.

  Therefore, as long as such a heat pump is used, the temperature of the remaining hot water in the hot water tank 1 may drop below 65 ° C. as shown in FIG. Then, the temperature of the hot water circulating in the circulating hot water supply circuit 3 cannot be maintained at 65 ° C. That is, the hot water use situation affects the nighttime heat storage amount, which is repeatedly affected the next day, leading to a decrease in the temperature of the remaining hot water.

  In order to avoid such a situation, restrictions such as making the restriction of the heat radiation amount more strict or keeping the hot water in the hot water storage tank 1 as much as possible are generated. Therefore, when installing a hot water supply device, it is necessary to determine the scale of the hot water supply device in advance by taking into consideration these factors and assuming the circulation heat radiation load, the amount of hot water supply used, and the like.

  However, for business use, the load fluctuation is large and its prediction is difficult, so it cannot be said that it is convenient to use. You will have to deal with whispering.

  In this respect, in the present embodiment, the hot water from the circulating hot water supply circuit 3 whose temperature has been lowered is stored in the sub tank 34 and does not flow directly into the hot water tank 1, so that the intermediate temperature region is formed large as shown in FIG. Since the amount of heat stored by the high-temperature hot water can be ensured, the remaining hot water temperature does not decrease to 65 ° C. or lower.

  More specifically, when hot water flows from the hot water storage tank 1 through the hot water supply pipe 51 into the circulating hot water supply circuit 3 in order to heat the hot water in the circulating hot water supply circuit 3, hot water is circulated by that amount. Part of the water flows into the upper portion of the sub tank 34 from the hot water return pipe 33, and accordingly, the water stored in the lower portion of the sub tank 34 flows into the vicinity of the bottom 1 c of the hot water tank 1. By these continuous flows, the hot water temperature in the circulating hot water supply circuit 3 is maintained at a predetermined temperature (for example, 65 ° C.). Thus, according to the present embodiment, it is possible to maintain a high COP compared to the previous embodiment in which the sub tank 34 is not provided.

  When hot water is used after being discharged from the hot water terminal 4, the medium temperature hot water from the sub-tank 34 and the high temperature hot water from the hot water storage tank 1 are appropriately mixed through the thermovalve 20, and are entered into the circulating hot water supply circuit 3. Since it flows in, the hot water in the sub tank 34 is consumed, and the consumed amount is replenished from the water supply pipe 50. That is, here, the sub tank 34 functions as a water supply pipe having a high water temperature.

  The capacity of the sub-tank 34 may be determined in consideration of a hot water supply load, a heat radiation load, a hot water supply pattern, and the like, but is usually about 10 to 20% of the volume of the hot water tank 1. In the present embodiment, the sub tank 34 has a capacity of 450 L with respect to the capacity 3000 L of the hot water tank 1.

  Thus, according to this embodiment, the necessary heat storage amount in the hot water storage tank 1 can be secured without being affected by the amount of hot water used, and the hot water stored using the nighttime power by the heat pump unit 40 can be efficiently used. Since it can be used, the capacity of the hot water storage tank 1 can be kept to the minimum necessary, and a hot water supply device capable of sufficiently responding to a large hot water supply load or hot water supply load fluctuation while reducing initial costs and running costs is provided. it can.

  In the hot water tank 1 according to the present embodiment, the upper cylindrical rectifying member 8 and the lower cylindrical rectifying member 9 described in the first embodiment can be arranged as necessary.

  In that case, while receiving the hot water flowing in from the pouring pipe 54 at the upper cylindrical rectifying member 8 disposed on the ceiling portion 10b side of the interior, and guiding it to the ceiling portion 10b side in the hot water tank 1 while decelerating, The lower cylindrical rectifying member 9 provided on the bottom 10c side of the hot water tank 1 may receive the water flowing from the water supply pipe 50 once and guide it to the bottom 10c side in the hot water tank 1 while decelerating. Further, the lower tubular rectifying member 9 may be made to pass through the tip of the hot water return pipe 33 that is downstream of the sub tank 34 to temporarily receive the low-temperature water flowing from the sub tank 34.

(Modification)
FIG. 8 is a schematic explanatory view showing a modification of the hot water supply apparatus according to the second embodiment, and a modification of the present embodiment will be described with reference to FIG.

  As shown in the figure, in this modification, the hot water tank 1 is not configured as a single tank structure, but a plurality of small hot water tanks 11 are connected in series.

  That is, in this embodiment, since the hot water from the circulating hot water supply circuit 3 is not directly returned to the hot water storage tank 1 but stored in the sub tank 34 as in the first embodiment, the degree of freedom in designing the hot water supply device is increased. It is possible to use a plurality of small hot water tanks 11a to 11e.

  In this modification, when hot water from the circulating hot water supply circuit 3 flows into the sub tank 34, as shown in FIG. 8, the low temperature water at the lower side of the sub tank 34 flows into the final small hot water tank 11e and is stored. The hot water is gradually pushed up, and high-temperature hot water flows into the circulating hot water supply circuit 3 from the small hot water tank 11a at the top stage.

  With this configuration, the following effects are produced.

  That is, since the hot water supply device using a heat pump is often used in a small-scale system such as home use, the small hot water tank 11 has already been mass-produced. If a necessary number of small-sized hot water storage tanks 11 that are mass-produced are connected to ensure the required capacity, the cost can be reduced as compared with the construction of a large hot water tank each time according to the scale of the equipment. .

  By the way, although a thermo valve is used as a mixing valve in the present embodiment, an electric valve may be used. In that case, a temperature detector for detecting the temperature in the circulating hot water supply circuit 3 and a controller for controlling the valve opening of the electric valve based on the temperature detected by the temperature detector are provided. Is natural.

  Moreover, the heater which used the fuel via the auxiliary | assistant circulation flow path for hot water storage to the said hot water storage tank 1 (including what connected multiple small hot water storage tank 11) similarly to the 2nd modification of Embodiment 1 (refer FIG. 4). Can be connected in communication.

  The following hot water supply apparatus is realized from the second embodiment described above.

  That is, a hot water storage tank 1 connected to a raw water supply path (for example, a water supply pipe 50) is connected to a hot water storage circulation channel (for example, a water intake pipe 53, a pouring pipe 54, and a hot water supply pipe 51. 53 → heat pump unit 40 → pour pipe 54 → hot water pipe 51 → flow path that circulates with hot water storage tank 1) A heat pump (for example, heat pump unit 40) is connected in communication, and the hot water heated by the heat pump is stored in the hot water storage tank. 1 and a circulating hot water supply circuit 3 having a hot water discharge terminal 4 (for example, a faucet or a shower head) attached to a hot water supply path (for example, a hot water supply pipe 51) connected to the hot water storage tank 1 in communication. In the hot water supply apparatus capable of supplying hot water from the hot water terminal 4, the hot water supply path and the circulating hot water supply circuit are connected in communication via a mixing valve (for example, a thermo valve 20), and the circulation A sub tank 34 for temporarily storing the hot water is provided in the middle of the hot water pipe 33 branched from the middle of the hot water circuit 3 and connected to the bottom portion 10c of the hot water tank 1 and connected to the circulating hot water circuit. The hot water (high temperature hot water) stored in the hot water storage tank 1 is caused to flow into the circulating hot water supply circuit 3 by the amount of returned hot water flowing in from the hot water tank 3, and the hot water in the circulating hot water supply circuit 3 is kept within a predetermined temperature range (for example, 65 A hot water supply device that can be maintained at a temperature of ~ 70 ° C.

  As mentioned above, although this invention was demonstrated through each embodiment, only the specific example was illustrated in embodiment, and this invention is not specifically limited.

  That is, the design of the shape of the hot water tank 1, the piping of each flow path, the specific structure of the mixing valve 2, and the like can be changed as appropriate.

  Further, for example, the mixing valve 2 is a thermo element that senses temperature, such as the one that is electrically controlled as described in the first embodiment, or the thermo valve 20 described in the second embodiment. The thermoelement may be appropriately determined, such as a configuration in which the thermoelement expands and contracts due to temperature and automatically adjusts the opening degree of the valve body.

  Furthermore, in order to adjust the ratio of high-temperature hot water from the hot water tank 1 that flows into the circulating hot water supply circuit 3 or raw water that flows from the water supply pipe 50, for example, an electromagnetic valve, a flow path switching valve, a constant flow valve, etc. It is also possible to adopt a configuration in which these are appropriately combined.

  In addition, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the above-described embodiments.

It is typical explanatory drawing which shows the structure of the hot water supply apparatus which concerns on 1st Embodiment. It is explanatory drawing which shows the outline of the internal structure of the hot water storage tank shown in FIG. It is typical explanatory drawing which shows the structure of the hot water supply apparatus which concerns on a 1st modification. It is typical explanatory drawing which shows the structure of the hot water supply apparatus which concerns on a 2nd modification. It is typical explanatory drawing which shows the structure of the hot water supply apparatus which concerns on 2nd Embodiment. It is a graph which shows the result of having simulated change of the amount of remaining hot water and the remaining hot water temperature of the hot water storage tank concerning a 1st embodiment. It is a graph which shows the result of having simulated change of the amount of remaining hot water of the hot water storage tank concerning a 2nd embodiment, and remaining hot water temperature. It is typical explanatory drawing which shows the modification of the hot water supply apparatus which concerns on the 2nd Embodiment. It is typical explanatory drawing which shows the structure of the conventional hot water supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Mixing valve 3 Circulating hot water supply circuit 4 Terminal for intake 6 Temperature detector 7, 7 'Controller 8 Upper cylindrical rectification member 9 Lower cylindrical rectification member 20 Thermo valve 32, 33 )
40 Heat pump unit 44 Pressureless heater 50 Water supply pipe (raw water supply path)
51 Hot water supply pipe (hot water supply path)

Claims (2)

A hot water tank connected in communication with the raw water supply path is connected to a heat pump through a hot water circulation channel, and hot water heated by the heat pump is stored in the hot water tank and connected to the hot water tank. In a hot water supply apparatus that allows a circulating hot water supply circuit attached with a hot water terminal to communicate with the hot water terminal,
The hot water supply passage and the circulating hot water supply circuit are connected and connected through a mixing valve, and the return hot water is temporarily placed in the middle of the return hot water passage branched from the middle of the circulating hot water supply circuit and connected to the bottom side of the hot water storage tank. A sub-tank for storing the water is provided, and hot water stored in the hot water storage tank is caused to flow into the circulating hot water supply circuit by the amount of returned hot water flowing into the sub tank from the circulating hot water supply circuit. A hot water supply apparatus characterized in that it can be maintained in a predetermined temperature range. The hot water supply apparatus according to claim 1, wherein a heater using fuel is connected to the hot water storage tank through an auxiliary circulation channel for hot water storage.

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