JP2850811B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus capable of performing a cold storage operation.

[0002]

2. Description of the Related Art An uncomfortable indoor environment in a hot and humid summer can be made comfortable by cooling and dehumidifying using an air conditioner. For this reason, the spread of air conditioners is remarkable, but on the other hand, there is a case where power demand reaches a peak in the daytime in the middle of summer due to cooling, and there is a problem that power supply is limited in large factories and the like. In such a case, if cold energy can be stored by using inexpensive electricity at night and used to reduce the cooling load of the air conditioner during the day, it would be economical as well as alleviate the peak of power demand. Will be helpful.

[0003] In order to solve the above problem from such a viewpoint, there is a hot water supply apparatus described in Japanese Patent Application Laid-Open No. 6-159845. FIG. 15 is a circuit diagram showing a water system of the conventional hot water supply apparatus. This hot water supply apparatus has a heating tank 31 having a built-in electric heater 30 as heating means.
And a first hot water storage tank 32 for storing hot water and a second hot water storage tank 33 for storing hot or cold water.
A hot water supply pipe 35 is connected to the tops of the first and second hot water storage tanks 32 and 33, and a water supply pipe 36 is connected to the bottoms of the heating tank 31 and the second hot water storage tank 33 via a second three-way valve 42, respectively. The bottom of the tank 32 and the second hot water storage tank 3
3 is connected by a pipe 37. In addition, one end 38a of a circulation pipe 38 provided with a pump 40 and a double-pipe heat exchanger 39 which is switched to a condenser or an evaporator of a heat pump system is connected to the bottom of the heating tank 31, while a first three-way valve is provided. Circulation pipe 3 branching into two via 41
8 are connected to the bottoms of the heating tank 31 and the second hot water storage tank 33, respectively.

The second three-way valve 42 and the second hot water storage tank 33
A fourth three-way valve 44 for branching a water supply branch pipe 47 connected to the bottom of the first hot water storage tank 32 is provided in the water supply pipe 36 between the heat exchanger 39 and the heating tank 31. The pipe 38 is provided with a third three-way valve 43 for branching a circulation first branch pipe 48 connected to the top of the second hot water storage tank 33, and a circulation between the first three-way valve 41 and the second hot water storage tank 33. The pipe 38 is provided with a fifth three-way valve 45 for branching a circulation second branch pipe 49 connected to the bottom of the first hot water storage tank 32. Further, based on various command signals from a control device (not shown), the heat exchanger 39 is switched to one of a condenser and an evaporator, and the three-way valves 41 to 45 are switched and the pump 10 is switched. A controller 50 for controlling start and stop is provided. The inlet side of the water supply pipe 36 is connected to the water supply port 34, while the outlet side of the hot water supply pipe 35 has a distal end provided with a water supply port 37 a.
It is also connected to the water supply pipe 36 by the.

Next, when the controller 50 receives a cold storage operation command, for example, at night in summer, the controller 50 causes the heat exchanger 39 to function as an evaporator, and at the same time, causes the first and fifth three-way valves 41 and 45 to switch to (3) The three-way valve 43 is switched to the solid line side, and the pump 40 is driven in reverse. Then, the circulation pipe 38 communicates only with the second hot water storage tank 33, and only the water in the second hot water storage tank 33 circulates through the heat exchanger 39 as shown by the dashed arrow in FIG. Will be stored. Subsequently, when the controller 50 receives the cooling operation command, the controller 50 causes the heat exchanger 39 to function as a condenser, and
1 to 45 are switched to the same state as when the cold storage operation command is received, and the pump 40 is driven to rotate forward. The cold water thus stored in the second hot water storage tank 33 is circulated in the direction of the solid line arrow through the heat exchanger 39, and is cooled in the heat exchanger 39 functioning as a condenser. Thus, when the heat pump system is applied as an air conditioner, it becomes possible to perform indoor cooling without activating the outdoor heat exchanger (not shown), so that the cooling load can be reduced. Has become.

In order to supply hot water with cold water stored in the second hot water storage tank 33 as described above, the controller 5
0, when the hot water supply operation command is received, the heat exchanger 39 functions as a condenser, and at the same time, the first and third three-way valves 41 and 43 are switched to the broken line side and the fifth three-way valve 45 is switched to the solid line side.
0 is driven forward. Then, the hot and cold water in the heating tank 31 and the first hot water storage tank 32 can be circulated through the heat exchanger 39, and the hot and cold water in both tanks 31, 32 can be boiled. Then, by switching the communication state of the second and fourth three-way valves 42 and 44 and applying a water supply pressure from the water supply pipe 36, hot water can be supplied from the hot water supply port 37a. The automatic mixer tap 46 is connected to the heating tank 31 and the first hot water storage tank 32.
This is provided to prevent a user from being burned when switching the hot water tank between. Thus, in the above-described conventional hot water supply apparatus, cold storage for reducing the cooling load and hot water supply or hot water storage are possible.

[0007]

However, in the above conventional example, the cold storage tank 33 is replaced with the hot water storage tanks 31 and 3.
2 must be provided separately. Along with this, a water system such as a branch circuit becomes complicated, and the number of parts such as a three-way valve also increases. Therefore, there is a problem that the apparatus becomes complicated, which causes an increase in cost, and that the control becomes complicated and it is difficult to easily obtain a stable operation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and has as its object to provide a hot water supply apparatus capable of storing and supplying cold water or hot water with a simple configuration using a single hot water storage tank. Is to do.

[Means for Solving the Problems]

Therefore, the hot water supply apparatus according to claim 1 has a first hot water supply port 2 at a lower end portion through which city water to be supplied flows, and a hot water supply tank 1 having a hot water supply port 3 at an upper end portion through which hot water flows out. And a heat exchange path 5 provided so as to be capable of exchanging heat with the heat exchanger 4 functioning as a condenser or an evaporator of the heat pump system and having a circulation pump 15 interposed therebetween. 5 is connected to a hot water outlet 6 provided at an intermediate portion of the hot water storage tank 1, while its inlet side 5b is connected to a water intake 7 provided at a lower end of the hot water storage tank 1, Circulation pump 1
In the hot water supply device for controlling the temperature of the hot water in the hot water storage tank 1 by operating the hot water storage tank 5, a water outlet 8 is provided in the hot water storage tank 1 at a position lower than the hot water outlet 6, and the hot water storage tank 5 The first flow path switching means 26 switches between a first switching state in which the hot water flows into the main unit 1 mainly through the tap hole 6 and a second switching state in which the inflow mainly flows through the water outlet 8. And a control means 14 provided by the first flow path switching means 2 so as to be in a first switching state when a hot water supply operation command is issued.
6 and the heat exchanger 4 functions as a condenser to supply hot water. When a cold storage operation command is issued, the first flow path switching means 26 is switched so as to be in the second switching state, and the heat exchange is performed. The heat exchanger 4 functions as a condenser and is cooled by the heat exchange passage 5 when the cooling operation is commanded. It is characterized by:

In the hot water supply apparatus of the first aspect, the supply of hot water to the hot water storage tank 1 at the time of hot water supply is performed from the hot water outlet 6, and the supply of cold water to the hot water storage tank 1 at the time of cold storage is below the hot water outlet 6. From the water outlet 8 provided at the position. Therefore, the hot water heated by the heat exchanger 4 is located on the upper end side of the hot water storage tank 1 near the outlet 6 and the lower end is located on the lower end side of the vicinity of the outlet 8 without being mixed by the supply of hot or cold water. The cold water cooled by the heat exchanger 4 is stably separated and stored. Since the water inlet 7 for cooling water is provided at the lower end of the hot water storage tank 1 and the hot water supply port 3 for hot water is provided at the upper end thereof, the hot water supply dedicated to hot water storage using the single hot water storage tank 1 is provided. Cold storage and hot water supply or hot water storage can be performed by a simple device with only a few components added to the device.

In the hot water supply apparatus of the second aspect, the control means compares the city water temperature Ts with the return water temperature Tm at the outlet side 5a of the heat exchange path 5 during the cooling operation. When the water temperature Tm is higher than the city water temperature Ts, the first flow path switching unit 26 is set to the first switching state. On the other hand, when the water temperature Tm is lower than the city water temperature Ts. It is characterized in that the first flow path switching means 26 is controlled to be in the second switching state.

In the hot water supply apparatus of the second aspect, the water which has become higher in temperature than the city water due to cooling is returned to the upper end side from the vicinity of the tap 6, and the water which is still lower in temperature than the city water is The water is returned to the lower end side from the vicinity of the water outlet 8. Therefore, it is possible to prevent the temperature of the stored cold water from rising due to the return from the heat exchange path 5, and to improve the efficiency of the cooling operation.

Further, in the hot water supply apparatus according to the third aspect, a hot water inlet 9 is provided near an intermediate portion between the hot water outlet 6 and the water outlet 8 of the hot water storage tank 1.
A first switching state in which hot water flows out of the hot water storage tank 1 to the heat exchange path 5 mainly through the water intake port 7 and a second switching state in which the water flow out mainly flows through the hot water inlet 9. A second flow path switching means 27 for switching between a switching state and a switching state is provided, and the control means 14 controls the second flow path switching means 2 so as to be in the second switching state when a hot water supply operation command is issued.
7 and the heat exchanger 4 functions as a condenser to supply hot water. When a cold storage operation command is issued, the second flow path switching means 27 is switched to the first switching state and the heat exchange is performed. The cooling device is made to function as an evaporator to store cold water, and when a cooling operation command is issued, the second flow path switching means 27 is switched so as to be in the first switching state, and the heat exchanger 4 is condensed. It is characterized in that it is made to function as a vessel and controls to cool down in the heat exchange path 5.

In the hot water supply apparatus of the third aspect, a hot water inlet 9 is provided near an intermediate portion between the hot water outlet 6 and the water outlet 8, and hot water to be heated at the time of hot water supply is taken out from the hot water outlet 9. Therefore, even if cold water is stored, it is possible to circulate hot water for heating without affecting this, and to heat relatively hot water, thereby improving the heating efficiency. It is possible to do.

In the hot water supply apparatus of the fourth aspect, a second water supply port 10 is provided at a position where city water can be supplied to the vicinity of an intermediate portion between the hot water supply port 9 and the water discharge port 8, so that the water supply to the hot water storage tank 1 can be performed. The third flow path switching means 28 for switching between a first switching state in which the supply of water is mainly performed through the first water supply port 2 and a second switching state in which the supply is mainly performed through the second water supply port 10 is provided. The control means 14 is characterized in that when cold water is stored in the hot water storage tank 1, control is performed to switch the third flow path switching means 28 so as to be in the second switching state. .

In the hot water supply device of the fourth aspect, the supplied city water is stored between the hot water and the cold water stored in the hot water storage tank 1 to form a boundary layer. Therefore, it is possible to avoid direct heat exchange between the hot water and the cold water, and it is possible to further improve the efficiency of the cold storage and hot water supply operation. In addition, by applying a water supply pressure to the second water supply port 10 at the time of tapping, it is possible to tap the hot water via the water supply port 3 without affecting the stored cold water.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of the hot water supply apparatus of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing a water system in the water heater. In FIG. 1, reference numeral 1 denotes a hot water storage tank containing an electric heater 16, and reference numeral 4 denotes a double-pipe heat exchanger functioning as a condenser or an evaporator of a heat pump system to be described later. And this heat exchanger 4
A heat exchange path 5 is provided so as to be able to exchange heat with water, and hot water flows from its inlet side 5b to its outlet side 5a by the operation of a circulation pump 15 interposed therebetween. The outlet side 5a of the heat exchange path 5 branches into a tapping pipe 17 and a tapping pipe 18 via a first three-way valve 11, and the tapping pipe 17 is provided at a tapping port 6 provided at an intermediate portion of the hot water storage tank 1. On the other hand, the water outlet pipe 18 is connected to the water outlet 8 provided in the hot water storage tank 1 at a position below the water outlet 6. And these first three-way valve 11, tapping pipe 1
The first channel switching means 26 is constituted by the drainage pipe 7 and the water outlet pipe 18. On the other hand, the inlet side 5b of the heat exchange path 5
It branches into a hot water pipe 19 and a water intake pipe 20 via the three-way valve 12. The hot water supply pipe 19 is connected to the hot water supply port 9 provided in the hot water storage tank 1 at an intermediate position between the hot water supply port 6 and the water discharge port 8, while the water supply port 7 provided at the lower end of the hot water storage tank 1 is connected to An intake pipe 20 is connected. The second three-way valve 12, the hot water pipe 19, and the water intake pipe 20 constitute second flow path switching means 27. In the same figure, reference numeral 22 denotes a water supply pipe for supplying city water to the hot water storage tank 1 while applying a water supply pressure, and the hot water storage tank 1 side is the third water supply pipe.
A first water supply port 2 provided at a lower end of the hot water storage tank 1 is branched into a first water supply pipe 24 and a second water supply pipe 25 via the three-way valve 13.
The first water supply pipe 24 is connected to the
The second water supply pipe 25 is connected to the second water supply port 10 provided in the hot water storage tank 1 at an intermediate position between the water supply port 8 and the water supply port 8. The third three-way valve 13 and the first water supply pipe 24
And the second water supply pipe 25 constitutes a third flow path switching means 28. A hot water supply port 3 is provided at the upper end of the hot water storage tank 1.
Is provided, a hot water supply pipe 23 is connected, and a drain pipe 21 for draining hot water stored in the hot water storage tank 1 is provided at a lower end portion. The above water system circuit is controlled by the control means 14.
The control means 14 is configured using a microcomputer having a CPU, a memory, an input / output interface, and the like. A water temperature sensor 5c for detecting the temperature Tm of the water returned from the heat exchange path 5 to the hot water storage tank 1 is provided at the outlet side 5a of the heat exchange path 5.
On the other hand, the second water supply pipe 25 is provided with a city water temperature sensor 25a for detecting the temperature Ts of city water supplied to the hot water storage tank 1. Then, the water temperature Tm and the city water temperature Ts detected by the respective sensors 5c and 25a.
Is input to the control means 14.

FIG. 2 is a circuit diagram showing a refrigerant system of a heat pump system provided with the heat exchanger 4. This heat pump system includes an outdoor heat exchanger 5 having a compressor 51, a four-way switching valve 52, and an outdoor fan 54 as shown in FIG.
3, expansion valve 60, and indoor expansion valves 68a to 68, respectively.
indoor heat exchanger 56a connected in parallel with each other
56c are sequentially connected by conduits 69a to 69f, and a liquid shutoff valve 62 and a receiver 5 are connected to a conduit 69d toward the expansion valve 60.
5 and a gas shut-off valve 63 in the line 69e. Also, the discharge line 69 of the compressor 51
a, a first electromagnetic valve 58 is interposed, a first conduit 70a having a second electromagnetic valve 59 and a first shut-off valve 65 interposed is branched from the first electromagnetic valve 58, and the end thereof is connected to one end of the heat exchanger 4. While the other end of the heat exchanger 4 and the liquid receiver 55 are connected to the second closing valve 64.
And a second conduit 7 interposed with a first capillary tube 67
0b. And the compressor 5 of the first closing valve 65
The first pipe 70a on the first side is connected to a suction pipe 69f of the compressor 51 by a third pipe 70c provided with a third solenoid valve 61, and provided on the liquid receiver 55 and the suction pipe 69f. The accumulator 57 is connected to the accumulator 57 by a fourth conduit 70d including the second capillary tube 66.

Next, the operation of the hot water supply apparatus having the above configuration will be described. First, a control device (not shown) for the entire hot water supply device
, The control means 14 performs the following control on the refrigerant system circuit. That is, FIG.
Is switched to the passage side indicated by the solid line,
The first solenoid valve 58, the third solenoid valve 61, and the expansion valve 60 are opened, while the second solenoid valve 59 and the liquid closing valve 62 in the line 69d are opened.
Is closed, and the refrigerant discharged from the compressor 51 is circulated as indicated by the dashed arrow in the figure, and the heat exchanger 4 functions as an evaporator. On the other hand, for the water system circuit, the circulating pump 15 is operated by switching the first three-way valve 11 and the third three-way valve 13 shown in FIG. 1 to the broken line side and switching the second three-way valve 12 to the solid line side. . Then, as shown in FIG. 3, the stored water inside flows out of the water intake port 7 provided at the lower end of the hot water storage tank 1, and flows through the heat exchange path 5 via the water intake pipe 20.
At this time, this water is used as a heat exchanger 4 functioning as an evaporator.
Then, the water is cooled and becomes cold water, and is returned to the inside of the hot water storage tank 1 again from the water outlet 8 through the water discharge pipe 18. By continuing such an operation, the cold water is stored at the lower end side of the hot water storage tank 1 near the water outlet 8.

Next, a case where the cooling operation is performed using the cold water stored as described above will be described. The control means 14 performs control for performing the cooling operation using the cold water in response to a cooling operation command from a control device (not shown) of the entire hot water supply apparatus. The four-way switching valve 52 shown is switched to the side shown by the solid line to close the first solenoid valve 58, the third solenoid valve 61, and the expansion valve 60, while the second solenoid valve 59, the liquid shut-off valve 62, and the gas shut-off valve are closed. 63
Is opened, and the refrigerant discharged from the compressor 51 is circulated as indicated by the dashed line in FIG. And the indoor heat exchanger 56a ~
56c functions as an evaporator, and the heat exchanger 4 functions as a condenser without operating the outdoor heat exchanger 53. On the other hand, for the water system circuit, the second three-way valve 12 shown in FIG. 1 is switched to the solid line side, and the third three-way valve 13 is switched to the broken line side. The first three-way valve 11 is controlled based on the city water temperature Ts detected by the city water temperature sensor 25a and the return water temperature Tm detected by the water temperature sensor 5c. This control will be described with reference to a flowchart shown in FIG. 14. In step S1, the water temperature Tm and the city water temperature T
s and if the water temperature Tm is equal to or lower than the city water temperature Ts, the process proceeds to step S2 to switch the first three-way valve 11 to the broken line side. On the other hand, when the water temperature Tm is higher than the city water temperature Ts, the process proceeds from step S1 to step S3, and switches the first three-way valve 11 to the solid line side. Then, the process proceeds from step S2 and step S3 to step S4, in which it is determined whether the cooling operation is continuing. If the cooling operation is continuing, the flow returns to step S1 again, and the above-described routine is repeated. When the circulating pump 15 is operated by switching the three-way valves 11, 12, and 13 by the above control, the cold water stored in response to the cold storage operation command is transferred to the lower end of the hot water storage tank 1 as shown in FIG. And flows through the heat exchange path 5 via the water intake pipe 20. Then, the cold water is allowed to cool down to the heat exchanger 4 functioning as a condenser, and is returned to the hot water storage tank 1 again. At this time, the temperature of the cold water rises by absorbing heat in the heat exchange path 5, but when the temperature is still lower than that of the city water, the cold water returns to the lower end side near the water outlet 8 while When the temperature is already higher than the city water, the water is returned to the upper end side from the vicinity of the tap 6. Therefore, it is possible to prevent the temperature of the stored cold water from being raised by hot water having a higher temperature than city water, and to perform a cooling operation with high efficiency. Also, instead of the above control for the first three-way valve 11, the first three-way valve 11 shown in FIG.
The circulation pump 15 may be operated while fixing the position on the broken line side. In this case, if the return flow temperature becomes high, there is a possibility that the stored cold water may have some influence. However, since the city water temperature sensor 25a and the water temperature sensor 5c become unnecessary, the configuration and the control are not required. Can be simplified and cost can be reduced.

Further, a hot water supply operation performed in a state where cold water is stored at the lower end side of the hot water storage tank 1 as described above will be described. When receiving a hot water supply operation command from a control device (not shown) of the entire hot water supply device, the control means 14 switches the four-way switching valve 52 shown in FIG. , The first solenoid valve 58, the third solenoid valve 61, and the liquid shut-off valve 62 in the pipe 69d are closed, while the second solenoid valve 5 is closed.
9 and the expansion valve 60 are opened, and the refrigerant discharged from the compressor 51 is circulated as shown by the solid line in the figure, so that the heat exchanger 4 functions as a condenser. On the other hand, for water system circuits,
The circulating pump 15 is operated by switching the first three-way valve 11 shown in FIG. 1 to the solid line side, and switching the second three-way valve 12 and the third three-way valve 13 to the broken line side. Then, as shown in FIG. 5, stored water flows out of hot water inlet 9 provided in hot water storage tank 1 at a position above water outlet 8, and this flows into hot water pipe 19.
Through the heat exchange path 5. At this time, the stored water is heated by the heat exchanger 4 functioning as a condenser, and is again supplied from the hot water outlet 6 through the hot water pipe 17 to the hot water storage tank 1.
Will be returned within. By continuing such an operation, the heated hot water is stored on the upper end side of the hot water storage tank 1 rather than near the hot water inlet 9 without affecting the stored cold water. At this time, hot water is supplied from the hot water supply port 3 as shown in FIG. 6 by supplying water into the hot water storage tank 1 while applying water supply pressure from the second water supply port 10 via the second water supply pipe 25. However, since the cold water is stored at the lower end side of the water outlet 8, the stored cold water can be supplied without affecting the temperature rise due to mixing with city water.

FIGS. 7 and 8 show a hot water storage operation in which hot water is stored in the hot water storage tank 1 without storing cold water. The hot water storage operation is performed when the control means 14 receives a hot water storage operation command from a control device (not shown) of the entire hot water supply apparatus. In this case, control of the refrigerant system circuit is performed when the hot water supply operation command is received. Since they are the same, the description here is omitted. For the water system circuit, the first
The three-way valve 11 is switched to the dashed line, the second three-way valve 12 is switched to the solid line, and the third three-way valve 23 is switched to the solid line.
Activate 5 By performing such control, hot water can be stored in the entire hot water storage tank 1 and a large amount of hot water can be supplied. At this time, if heating only in the heat exchange path 5 is not sufficient, the electric heater 16 can be used for further heating.

As described above, the hot water storage tank 1 of this hot water supply device
, Cold water is stored at a lower end side of the vicinity of the water outlet 8, and warm water is stored at an upper end side of the vicinity of the hot water inlet 9. And at this time, city water is supplied from the second water supply port 10,
As shown in FIG. 9A, a city water layer is formed between the hot water and the cold water. In the hot water supply device of the present embodiment, heat transfer does not occur directly between hot water and cold water due to the presence of such an intermediate layer of city water, and both are stably stored for a long time. be able to. FIG. 2B is a graph showing a change in temperature of the hot water and the cold water with the passage of time. As shown in the figure, since heat transfer is performed only between hot water and city water and between city water and cold water, a boundary layer is formed between hot water and cold water as indicated by arrows. Therefore, even with a simple configuration of the single hot water storage tank 1, the cold water generated by the cold storage operation can be effectively stored and used without heat loss.

When the conventional hot water supply apparatus shown in FIG. 15 is compared with the above hot water supply apparatus, it is clear that the structure is simplified. For example, in the conventional example, the number of hot water storage tanks was three, but in the above-described hot water supply device, only one was used. In the conventional case, five three-way valves were conventionally required. I have. Further, since a single hot water storage tank 1 is used, an automatic mixer tap which is necessary for preventing a burn when switching the hot water storage tank is unnecessary in the hot water supply apparatus of the above embodiment. Moreover, since the number of members requiring control is reduced in this way, not only can the cost be reduced,
Since the control itself can be simplified, stable operation can be easily ensured.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the present invention. For example, in the above hot water supply apparatus, as shown in FIG. 10A, the first flow path switching means 26 is configured by the first three-way valve 11, the hot water pipe 17 and the water discharge pipe 18, which is shown in FIG.
As shown in (2), a two-way valve 29, a tapping pipe 17 and a tapping pipe 18 may be used. However, at this time, the maximum flow rate of the water discharge pipe 18 is assumed to be sufficiently smaller than the maximum flow rate of the water discharge pipe 17, and when the two-way valve 29 is opened, the water discharge pipe 17
It is necessary to allow hot water to flow into the hot water storage tank 1 from the hot water outlet 6 through the hot water outlet 6.

FIGS. 11 to 13 show flow paths of the hot and cold water when each operation is performed by another embodiment of the hot water supply apparatus thus configured. At this time, there is no problem during the cold storage operation shown in FIG.
When the temperature Tm of the water returned from the water is higher than the city water temperature Ts) and during the hot water supply operation shown in FIG. 13, even when the two-way valve 29 is opened, a small amount of hot water is discharged from the water outlet 8 into the hot water storage tank 1 even when the two-way valve 29 is opened. Flow, which may cause a problem that this affects the stored cold water. In the hot water supply operation shown in FIG. 13, there is a possibility that heated hot water that slightly flows in from the water outlet 8 may immediately flow out of the water outlet 9 to the heat exchange path 5 again, so that the hot water supply efficiency is reduced. May cause problems. However, the three-way valve 11 is replaced with the two-way valve 2
Since a significant cost reduction effect can be obtained by setting it to 9, the above-described configuration may be advantageous if necessary, even if the above problem is subtracted. Such a configuration may be adopted for the second and third flow path switching means 27 and 28.

[0028]

According to the hot water supply apparatus of the first aspect, since cold storage and hot water supply or hot water storage can be performed with a simple configuration, cost can be reduced, and control can be simplified and stable operation can be easily obtained. It becomes possible.

Further, in the hot water supply apparatus according to any one of claims 2 to 4, it is possible to improve energy efficiency with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a water system circuit diagram of a hot water supply apparatus according to an embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram of the hot water supply apparatus.

FIG. 3 is a circuit diagram showing a cold storage operation of the water heater.

FIG. 4 is a circuit diagram showing a cooling operation of the water heater.

FIG. 5 is a circuit diagram showing a hot water supply operation of the hot water supply apparatus.

FIG. 6 is a circuit diagram showing a tapping operation of the hot water supply apparatus.

FIG. 7 is a circuit diagram showing a hot water storage operation of the hot water supply apparatus.

FIG. 8 is a circuit diagram showing a tapping operation of the hot water supply apparatus.

FIG. 9 shows a state of storing hot water in the hot water supply device,
(A) is a schematic cross-sectional view of a hot water storage tank, and (b) is a graph showing a temperature change of hot water.

10A and 10B are circuit diagrams illustrating a first flow path switching unit, in which FIG. 10A is a circuit diagram in the case of the above embodiment, and FIG. 10B is a circuit diagram in another embodiment.

FIG. 11 is a circuit diagram showing a cold storage operation of a water heater according to another embodiment.

FIG. 12 is a circuit diagram showing a cooling operation of a water heater according to another embodiment.

FIG. 13 is a circuit diagram showing a hot-water supply operation of a hot-water supply apparatus according to another embodiment.

FIG. 14 is a flowchart showing a cooling operation control of the water heater.

FIG. 15 is a water system circuit diagram of a conventional hot water supply apparatus.

[Description of Signs] 1 Hot water storage tank 2 First water supply port 3 Hot water supply port 4 Heat exchanger 5 Heat exchange path 5a Heat exchange path outlet side 6 Outlet port 7 Intake port 8 Outlet port 9 Inlet port 10 Second supply port 14 Control means 15 Circulation pump 26 First flow switching means 27 Second flow switching means 28 Third flow switching means Ts City water temperature Tm Water temperature

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-69646 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25B 13/00 F24F 5/00 F25B 29 / 00 F25B 30/02

Claims (4)

(57) [Claims] 1. A hot water storage tank (1) provided with a first water supply port (2) at a lower end portion for flowing city water to be supplied, and a hot water supply port (3) at an upper end portion for discharging hot water to be supplied.
And a heat exchange path (5) which is provided so as to be able to exchange heat with the heat exchanger (4) functioning as a condenser or an evaporator of the heat pump system and is provided with a circulation pump (15). The outlet side (5a) of the heat exchange path (5) is connected to a tap hole (6) provided at an intermediate portion of the hot water storage tank (1), while the inlet side (5b) is connected to the hot water storage tank. In the hot water supply device connected to the water intake port (7) provided at the lower end of (1) and operating the circulation pump (15) to control the temperature of hot water in the hot water storage tank (1), A water outlet (8) is provided in the hot water storage tank (1) at a position lower than 6), and inflow of hot water from the heat exchange path (5) to the hot water storage tank (1) is mainly performed by the hot water outlet (6). A first switching state performed through the A first flow path switching means (26) for switching between a second switching state via (8) and a control means (14) are provided. The control means (14) receives a hot water supply operation command when a hot water supply operation command is issued. In this case, the first flow path switching means (26) is switched so as to be in the first switching state, and the heat exchanger (4) functions as a condenser to supply hot water. When the first flow path switching means (26) is switched so as to be in the second switching state and the heat exchanger (4) is made to function as an evaporator to store chilled water, A hot water supply apparatus characterized in that the heat exchanger (4) functions as a condenser to perform cooling control by allowing the heat exchanger (4) to cool in the heat exchange path (5). 2. The control means (14) determines the city water temperature (Ts) and the return water temperature (Tm) at the outlet side (5a) of the heat exchange path (5) during the cooling operation. In comparison, when the water temperature (Tm) is higher than the city water temperature (Ts), the first flow path switching means (26) is set to the first switching state, while the city water temperature (Ts) is lower than the city water temperature (Ts). The above water temperature (T
2. The hot water supply apparatus according to claim 1, wherein when the value of m) is lower, the first flow path switching means is controlled to be in the second switching state. 3. A hot water inlet (9) is provided near an intermediate portion between the hot water outlet (6) and the water outlet (8) of the hot water storage tank (1),
A first switching state in which the outflow of hot water from the hot water storage tank (1) to the heat exchange path (5) is mainly performed through the intake port (7), and the outflow is mainly performed through the intake port (9). A second flow path switching means (27) for switching between a second switching state and a second switching state, wherein the control means (14) sets the second switching state so as to be in the second switching state when a hot water supply operation command is issued.
The flow path switching means (27) is switched and the heat exchanger (4) functions as a condenser to supply hot water. When a cold storage operation command is issued, the second flow path switching is performed so as to be in the first switching state. The means (27) is switched and the heat exchanger (4) is made to function as an evaporator to store cold water, and when a cooling operation command is issued, the second flow path is switched to the first switching state. 3. A method according to claim 1, wherein the means is switched so that the heat exchanger functions as a condenser and cools the heat in the heat exchange path. Water heater. 4. A second water supply port (10) is provided at a position where city water can be supplied near an intermediate portion between the hot water supply port (9) and the water discharge port (8), and the second water supply port (10) is provided to the hot water storage tank (1). A third switching state in which the supply of city water is mainly performed through the first water supply port (2) and a second switching state in which the supply is mainly performed through the second water supply port (10). Channel switching means (2
8), the control means (14) controls the switching of the third flow path switching means (28) so as to be in the second switching state when the cold water is stored in the hot water storage tank (1). 4. The hot water supply apparatus according to claim 3, wherein the hot water supply is performed.