JPH0914704A - Hot water storage system - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a hot water storage type hot water supply device which is highly reliable, low cost, and efficient. [Structure] At the bottom of the first, second and third tanks 1, 2, 3
The water supply pipes 10 are sequentially connected from the hot water storage tank 3 side.
One end of the heat exchanger 4 is connected to the water supply pipe 10 at the bottom of the first hot water storage tank 1 via the first circulation pipe 11. The second circulation pipe 1 is connected to the other end of the heat exchanger 4 and the bottoms of the second and third hot water storage tanks 2 and 3 respectively.
The first three-way valve 6 for branching the circulation branch pipe 13 connected to the upper part of the first hot water storage tank 1 is provided at 2. A pump 5 is arranged between the first hot water storage tank 1 and the heat exchanger 4. Then, the hot water supply pipes 14 are connected to the tops of the second and third hot water storage tanks 2 and 3, respectively, and the hot water supply branch pipes 15 connected to the top of the first hot water storage tank 1 are branched to the hot water supply pipes 14 A valve 7 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage type hot water supply device which can reduce the cooling load by utilizing one of the hot water storage tanks as a cold storage tank.

[0002]

2. Description of the Related Art Conventionally, there is an air conditioner that stores cold heat by using inexpensive electric power at night and can use it for reducing a cooling load of an air conditioner during the daytime. This air conditioner is provided with an evaporator in parallel with the indoor heat exchanger and a water-cooled heat exchanger in parallel with the outdoor heat exchanger so that at night, only the evaporator is operated to cool the water. The outdoor heat exchanger is stopped during the daytime, while the stored cold water flows through the water-cooled heat exchanger to efficiently condense the refrigerant gas and reduce the cooling load. However, the hot water storage type hot water supply apparatus requires a cold water tank, an evaporator, a water cooling type heat exchanger, and the like in addition to a normal refrigerant circuit, resulting in high equipment cost and a large installation space. There's a problem.

Therefore, the applicant of the present application pays attention to the fact that the load of hot water supply in summer when the water temperature is high is small, and the hot water storage tank is used as a cold water tank to store cold heat by electric power at night to reduce the cooling load in the daytime. I thought about a hot water storage type hot water supply device that can be used effectively. As shown in FIG. 4, the hot water storage type hot water supply device is
Heating tank 31, first and second hot water storage tanks 32 and 33, and air conditioner (only water-cooling type heat exchanger 34 is shown in FIG. 4)
In combination, the second hot water storage tank 33 of the three tanks is used as a cold storage tank, and the cold heat of the cold storage tank is used for cooling to reduce the cooling load.

That is, the heat exchanger 34 of the heat pump type refrigerant circuit of the air conditioner is used as an evaporator, and the three-way valves 41, 43, 4 are used.
5 is switched to the switching position of the dotted line, and the water in the second hot water storage tank 33 is passed through the circulation branch pipe 62, the pump 35, the heat exchanger 34, the circulation pipe 51 and the circulation branch pipe 61 as shown by the dotted arrow in FIG. By circulating it, cold water is stored in the second hot water storage tank 33. After that, during the cooling operation of the air conditioner, the heat exchanger 3
4 is a condenser, and cold water is circulated through the heat exchanger 34 in the same manner as when the cold storage is performed, so that the refrigerant gas is efficiently condensed. Further, in the hot water storage type hot water supply device, the heat exchanger 34 is used as a condenser, the three-way valves 41, 43 are switched to the switching positions indicated by solid lines, and the water in the heating tank 31 and the first hot water storage tank 32 is heated and boiled. Tap water is supplied from the water supply pipe 50 through the three-way valves 42 and 44 and the water supply branch pipes 52 and 53, and hot water is supplied from the hot water supply pipe 65.

[0005]

By the way, in the hot water storage type hot water supply apparatus, three three-way valves 41, 43, are used to switch between the heating tank 31 and the second hot water storage tank 33 as a cold storage tank.
Since 45 is required, there are drawbacks that the structure is complicated, reliability is reduced, and cost is high.

Further, since the hot water boiled in the heating tank 31 is transferred to the first hot water storage tank 32 and the second hot water storage tank 33 (when it is not used as a cold storage tank), the hot water and the water are mixed and COP (coefficient of hot water supply) There is a problem in that the efficiency of the device is deteriorated due to the deterioration of the performance.

Therefore, an object of the present invention is to provide a hot water storage type hot water supply device which is highly reliable, low cost and efficient.

[0008]

In order to achieve the above object, a hot water storage type hot water supply apparatus according to a first aspect of the present invention is provided with a first hot water storage tank and a second hot water storage tank each having water supply pipes connected to the bottom thereof, and the first hot water storage tank. One end is connected to the water supply pipe at the bottom of the tank via the first circulation pipe, and the other end is connected to the bottom of the second hot water storage tank via the second circulation pipe, and the condenser of the heat pump type refrigerant circuit is connected. Alternatively, the heat exchanger that performs the switching operation as an evaporator and the first circulation pipe that is disposed in the second circulation pipe
It is connected to the hot water storage tank via a circulation branch pipe so that the second circulation pipe on the heat exchanger side communicates with either one of the second circulation pipe on the second hot water storage tank side and the circulation branch pipe. Connected to the first three-way valve for switching to the above, the first circulation pipe or the pump arranged in the second circulation pipe between the first three-way valve and the heat exchanger, and the top of the second hot water storage tank The hot water supply pipe on the side of the second hot water storage tank and the hot water supply branch pipe connected to the top of the first hot water storage tank via a hot water supply branch pipe. And a second three-way valve that is switched so as to communicate with either one of the above.

[0009]

According to the hot water storage type hot water supply apparatus of claim 1, when the normal operation of heat storage and hot water supply is performed, the circulation branch pipe connected to the first hot water storage tank is provided on the heat exchanger side of the second circulation pipe. While switching the first three-way valve to communicate,
By switching the second three-way valve so that the hot water supply pipe on the hot water outlet side leads to the hot water supply branch pipe and operating the pump, the water in the first hot water storage tank acts as a condenser of the heat pump type refrigerant circuit. It can be heated and boiled by circulating it in a vessel. Then, tap water is supplied from the water supply pipe to the bottom of the first hot water storage tank, and tap water is discharged from the top of the first hot water storage tank through the hot water supply branch pipe, the second three-way valve, and the hot water supply pipe. In addition, the second connected to the bottom of the second hot water storage tank
The first three-way valve is switched so that the circulation pipe communicates with the heat exchanger side, and the second three-way valve is switched so that the hot water supply pipe on the second hot water storage tank side communicates with the hot water supply pipe on the hot water outlet side to operate the pump. By doing so, the water in the second hot water storage tank circulates through the heat exchanger that functions as a condenser, and is heated and boiled. Then, tap water is supplied from the water supply pipe to the bottom of the second hot water storage tank, and tap water is discharged from the top of the second hot water storage tank via the hot water supply pipe.

On the other hand, when the cold storage operation is performed, the first three-way valve is switched so that the circulation branch pipe connected to the first hot water storage tank communicates with the second circulation pipe on the heat exchanger side, and at the same time, on the hot water outlet side. By switching the second three-way valve so that the hot water supply pipe communicates with the hot water supply branch pipe and operating the pump, the water in the first hot water storage tank is circulated through the heat exchanger serving as the evaporator and cooled, and the first hot water storage Store cold water in the tank.
Then, the first and second three-way valves are set to the switching positions as they are, the heat exchanger is operated as a condenser, and the pump is operated, whereby the cold water in the first hot water tank circulates through the heat exchanger, The heat exchanger takes away heat and promotes the condensation of the refrigerant in the condenser of the refrigerant circuit. Therefore, the cooling load of the indoor heat exchanger that cools the room is reduced.

As described above, since the hot water storage type hot water supply device can be realized with a simple structure by using the first and second three-way valves, the reliability is high and the cost can be reduced. Also, compared to the case of transferring from the heating tank to the hot water storage tank,
Since water is heated in each hot water storage tank, there is little mixing of hot water and water, and efficiency can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The hot water storage type hot water supply apparatus of the present invention will be described in detail below with reference to an embodiment.

FIG. 1 is a schematic circuit diagram of a hot water storage type hot water supply apparatus according to an embodiment of the present invention, wherein 1 is a first hot water storage tank which also serves as a cold storage tank, 2 is a second hot water storage tank having an electric heater 8 therein, and 3 Is the third hot water storage tank. Water supply pipes 10 are sequentially connected to the bottoms of the first, second and third hot water storage tanks 1, 2, 3 from the third hot water storage tank 3. Further, 4 is a heat exchanger whose one end is connected to the water supply pipe 10 on the side of the first hot water storage tank 1 via the first circulation pipe 11 and the other end is connected to the second and third hot water storage tanks 2, 3. Reference numeral 5 denotes a pump 5 arranged in the second circulation pipe 12 connected to the other end of the heat exchanger 4.
A compressor, a four-way switching valve, an outdoor heat exchanger, an expansion valve, and the heat exchanger 4 (not shown) are sequentially circulated and connected to form a heat pump type refrigerant circuit.

A first three-way valve 6 is arranged in the second circulation pipe 12 between the pump 5 and the second and third hot water storage tanks 2 and 3, and the first three-way valve 6 and the first hot water storage tank are provided. A circulation branch pipe 13 is connected between the upper part and the upper part of 1. The first three-way valve 6 allows the second circulation pipe 12 on the heat exchanger 4 side to communicate with one of the second circulation pipe 12 and the circulation branch pipe 13 on the second and third hot water storage tanks 2, 3 side. Switch to.

Further, hot water supply pipes 14 are connected to the tops of the second and third hot water storage tanks 2 and 3, respectively, and a second three-way valve 7 is arranged in the hot water supply pipe 14 and the second three-way valve 7 is provided. First
A hot water supply branch pipe 15 is connected to the top of the hot water storage tank 1. The second three-way valve 7 is a hot water supply pipe 14 on the hot water outlet side.
However, the hot water supply pipe 14 and the hot water supply branch pipe 15 on the second and third hot water storage tanks 2 and 3 are connected to each other.

In the hot water storage type hot water supply apparatus having the above structure, in the case of normal hot water supply operation, the first three-way valve 6 is set to the switching position shown by the solid line in FIG. 1, and the heat exchanger 4 is operated as a condenser to operate the pump 5. Then, the water in the first hot water storage tank 1 is supplied to the water supply pipe 1
0, the first circulation pipe 11, the heat exchanger 4, the second circulation pipe 12, the first three-way valve 6 and the circulation branch pipe 13 are circulated as shown by the solid arrow in FIG. As a result, the first
The water in the hot water storage tank 1 is boiled up. In addition, the first
The three-way valve 6 is set to the switching position shown by the dotted line in FIG.
Is operated as a condenser to operate the pump 5 to supply the water in the second and third hot water storage tanks 2 and 3 to the water supply pipe 10 and the first circulation pipe 1
1. Heat is circulated through the heat exchanger 4 and the second circulation pipe 12. As a result, the water in the second and third hot water storage tanks 2 and 3 is boiled up. In the second hot water storage tank 2, the electric heater 8 is supplied with late-night power or the like as needed to promote boiling.

Then, tap water from the water supply pipe 10 is supplied to the bottoms of the first, second and third hot water storage tanks 1, 2, 3 to bring the second three-way valve 7 to the switching position shown by the solid line, Hot water is discharged from the top of the hot water storage tank 1 through the hot water supply branch pipe 15, the second three-way valve 7 and the hot water supply pipe 14, while the second three-way valve 7 is set to the switching position shown by the dotted line to set the second and third hot water storage tanks 2 and 3. Hot water is discharged from the top through the hot water supply pipe 14. Further, in the cold storage operation for cooling, as shown in FIG. 2, after the first three-way valve 6 is set to the switching position shown by the solid line and the second three-way valve 7 is set to the switching position shown by the dotted line, By operating the pump 5 by operating the heat exchanger 4 of the refrigerant circuit as an evaporator, the water in the first hot water storage tank 1 is supplied with the water supply pipe 10, the first circulation pipe 11, the heat exchanger 4, the second circulation pipe. 12, first three-way valve 6
And circulating circulation pipe 13 to circulate as shown by a dotted arrow in FIG. As a result, the water in the first hot water storage tank 1 is cooled and stored.

Next, with the first three-way valve 6 in the switching position indicated by the solid line, the heat exchanger 4 of the refrigerant circuit is operated as a condenser to operate the pump 5. In this way, the cooling operation stored in the water in the first hot water storage tank 1 is used to perform the cooling operation of the air conditioner. For example, by performing cool storage operation using cheap late-night power at summer night, etc., and performing cooling operation using cold water at the peak of daytime power demand,
It reduces power consumption and contributes to the alleviation of peak power demand.

As described above, a hot water storage type hot water supply apparatus can be realized with a simple structure, which uses the first hot water storage tank 1 as a cold storage tank to store cold water by electric power at night and the like to reduce the cooling load in the midsummer daytime. Therefore, the reliability can be improved and the cost can be reduced. Further, as compared with a hot water storage type hot water supply device in which the hot water is transferred from the heating tank to the hot water storage tank, the mixing of the hot water and the water is less, so the efficiency can be improved.

In the above embodiment, the second hot water storage tank is 2
Although the two second and third hot water storage tanks 2 and 3 are used, the number of the second hot water storage tanks may be an appropriate number.

[0021]

As is apparent from the above, in the hot water storage type hot water supply apparatus according to the first aspect of the present invention, the water supply pipes are respectively connected to the bottom portions of the first hot water storage tank and the second hot water storage tank, and the bottom portion of the first hot water storage tank is connected. The one end of the heat exchanger is connected to the water supply pipe of the second heat exchanger through the first circulation pipe, and the second heat exchanger is connected to the bottom of the second hot water storage tank.
The other end of the heat exchanger is connected via a circulation pipe, and the heat exchanger is switched to function as a condenser or an evaporator of a heat pump type refrigerant circuit, while it is disposed in the second circulation pipe and is the first hot water storage tank. The first three-way valve connected to the second circulation pipe on the heat exchanger side is switched so that the second circulation pipe on the heat exchanger side communicates with either the second circulation pipe on the second hot water tank side or the circulation branch pipe. A pump is provided in the first circulation pipe or a second circulation pipe between the first three-way valve and the heat exchanger, and a pump is provided in the hot water supply pipe connected to the top of the second hot water storage tank; The second three-way valve, which is connected to the top of the hot water storage tank via the hot water supply branch pipe, switches the hot water supply pipe on the hot water outlet side to either the hot water supply pipe on the second hot water storage tank side or the hot water supply branch pipe. is there.

Therefore, according to the hot water storage type hot water supply apparatus of the first aspect of the present invention, the circulation branch pipe connected to the first hot water storage tank is connected to the second circulation pipe on the heat exchanger side.
By switching the three-way valve and switching the second three-way valve so that the hot water supply pipe on the hot water outlet side leads to the hot water supply branch pipe and operating the pump, the water in the first hot water storage tank is circulated to the heat exchanger that acts as an evaporator. After cooling by allowing the heat exchanger to function as a condenser, the cold water stored in the first hot water storage tank is circulated to the heat exchanger to promote the condensation of the refrigerant in the condenser of the refrigerant circuit. Thus, the first
The hot water storage tank 1 is used as a cold storage tank to store cold water with electricity at night and to reduce the cooling load of the indoor heat exchanger that cools the room of the air conditioner during the daytime in midsummer. A hot water storage type hot water supply device including a cold storage tank can be realized. Therefore, the reliability can be improved and the cost can be reduced. Further, as compared with the hot water storage type hot water supply device that transfers the hot water from the heating tank to the hot water storage tank, since the first and second hot water storage tanks can be used as the heating tanks respectively, the mixing of hot water and water is less and the efficiency is improved. it can.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a flow of water during a cold storage operation of the hot water storage type hot water supply apparatus.

FIG. 3 is a diagram showing the flow of hot water when boiling water in the second and third hot water storage tanks of the hot water storage type hot water supply device.

FIG. 4 is a circuit diagram of a conventional hot water storage type hot water supply device.

[Explanation of symbols]

1 ... 1st hot water storage tank, 2 ... 2nd hot water storage tank, 3 ... 3rd hot water storage tank, 4 ... Heat exchanger, 5 ... Pump, 6 ... First three-way valve, 7 ... Second three-way valve 8 ... Electric heater, 10 ... water supply pipe, 11 ... first circulation pipe, 12 ... second circulation pipe, 13 ... circulation branch pipe, 14 ...
Hot water supply pipe, 15 ... Hot water supply branch pipe.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Yamazaki 1000 Otani, Okamoto-cho, Kusatsu-shi, Shiga No. 2 at Shiga Works, Daikin Industries, Ltd. (72) Inventor Takayuki Sugimoto 1000 Otani, Okamoto-cho, Kusatsu-shi, Shiga No. 2 Shiga Works of Daikin Industries, Ltd.

Claims (1)

[Claims] 1. A first hot water storage tank (1) and a second hot water storage tank (2, 3) each having a water supply pipe (10) connected to the bottom, and the water supply pipe at the bottom of the first hot water storage tank (1). One end is connected to (10) through the first circulation pipe (11),
At the bottom of the second hot water storage tank (2, 3), the second circulation pipe (1
The other end is connected via 2), and the heat exchanger (4) that performs switching operation as a condenser or evaporator of a heat pump type refrigerant circuit
And the second circulation pipe (12), which is connected to the first hot water storage tank (1) via a circulation branch pipe (13), and which is connected to the second circulation pipe on the heat exchanger (4) side. The pipe (12) is the second
A first three-way valve (6) which is switched so as to communicate with either one of the second circulation pipe (12) and the circulation branch pipe (13) on the side of the hot water storage tank (2, 3), and the first circulation pipe (11). ) Or a pump (5) arranged in the second circulation pipe (12) between the first three-way valve (6) and the heat exchanger (4), and the second hot water storage tank (2, 3) ) Is connected to the hot water supply pipe (14) connected to the top of the first hot water storage tank (1) via the hot water supply branch pipe (15), and the hot water supply pipe (14) on the hot water outlet side. Is provided with a second three-way valve (7) that is switched to communicate with either one of the hot water supply pipe (14) and the hot water supply branch pipe (15) on the second hot water storage tank (2, 3) side. A characteristic hot water storage type hot water supply device.