JPH1038327A - Ice heat storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To thaw ice flowing to a circulating passage from a heat storage tank with a simple structure and improve the efficiency of ice making operation. SOLUTION: An ice making device is provided with a refrigerant circulating circuit and a water circulating circuit B. In the ice making device, water taken out of a heat storage tank T by driving a pump P is supercooled by a supercooling heat exchanger 42, and ice nucleus formed in an ice nucleus forming device 46 is mixed into the water to cancel a supercooling state and make ice. The ice making device is provided with a preheater 40 for heating water in the downstream side of the pump P and a return pipeline for returning half of water supplied from the preheater 40 to the upstream side of the pump P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice heat storage device provided in an air conditioner or the like, and more particularly to the introduction of ice into a supercooling heat exchanger for cooling a liquid heat storage medium taken out of a heat storage tank. The improvement to suppress

[0002]

2. Description of the Related Art Conventionally, as an ice heat storage device provided in an ice storage type air conditioner or the like, in view of reducing power demand during peak cooling load and expanding power demand during off-peak time. In addition, there is known an apparatus in which slurry-like ice to be used as cooling heat at the time of a cooling load peak is generated at the time of a cooling load off-peak and stored in a heat storage tank.

As one example of this type of ice heat storage device, as disclosed in Japanese Patent Application Laid-Open No. Hei 4-251177, a compressor, a condenser, an expansion mechanism and a refrigerant heat exchange section are sequentially connected by refrigerant piping. And a water circulation circuit in which a heat storage tank, a heat storage medium heat exchange unit capable of exchanging heat with the refrigerant heat exchange unit, and a supercooling elimination unit are sequentially connected by a water pipe. Are known.

[0004] In the ice making operation of this type of ice heat storage device, water (heat storage medium) taken out from a heat storage tank to a water pipe is heat-exchanged with a refrigerant in a refrigerant heat exchange unit in a heat storage medium heat exchange unit. Cooling is performed to a cooling state, and the supercooled state is eliminated in the supercooling elimination section to generate slurry ice. Then, the ice is supplied to and stored in the heat storage tank.

[0005]

However, in such an ice heat storage device, during the ice making operation, ice in the heat storage tank may flow out to the circulation path due to the action of the suction force from the outlet of the heat storage tank. . Then, when such a situation occurs, the ice that has flowed into this circulation path reaches the heat storage medium heat exchange unit, and the supercooling elimination operation of water is performed around the ice,
Ice is generated in portions other than the subcooling elimination portion, and not only the ice making operation is not performed stably, but also the ice is attached to the wall surface of the heat exchange portion and grows, so that the heat exchange portion freezes. In addition, there is a possibility that the ice making operation becomes impossible.

In this type of apparatus, when the heat exchange section freezes, the ice making operation is stopped and the thawing operation for melting the ice is performed, but the heat exchange section is frozen. Occurs frequently, the frequency of the thawing operation also increases, leading to a decrease in the efficiency of the ice making operation as a whole.

[0007] The present invention has been made in view of the above, and an object of the present invention is to make it possible to melt ice flowing out of a heat storage tank into a circulation path with as simple a structure as possible.
It is to improve the ice making operation efficiency.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, the heat storage medium taken out from the heat storage tank into the circulation path is not directly introduced into the supercooling means, but is stored in the supercooling means. By returning a part of the medium to the pumping means,
The melting of the ice contained in the returned heat storage medium can be promoted.

Specifically, a heat storage tank (T) capable of storing a heat storage medium, a pumping means (P), and a supercooling means (42) are sequentially circulated by a circulation pipe (45) so that the heat storage medium can be circulated. A heat storage circulation circuit (B) connected to the heat storage tank
The liquid-phase heat storage medium taken out from (T) is pumped toward the supercooling means (42) by the pumping means (P), and cooled to a supercooled state in the supercooling means (42), which is then supercooled. After being derived from the means (42), it is assumed that the supercooled state is eliminated, ice in the form of slurry is generated, and the ice is stored in the heat storage tank (T) for storage. And the above-mentioned pressure feeding means
(P) is connected upstream and downstream, and a part of the heat storage medium pumped from the pumping means (P) toward the supercooling means (42) is returned to the upstream side of the pumping means (P). The configuration is such that a pipe (49) is provided. With this configuration, the operation during ice making
The heat storage medium taken out of the heat storage tank (T) is
To the supercooling means (42). Then, it is cooled to a supercooled state by the supercooling means (42), and after being derived from the supercooling means (42), the supercooled state is eliminated and the phase changes to ice. Then, this ice is collected in the heat storage tank (T) and stored as cold storage heat. In such an ice making operation, a part of the heat storage medium pumped from the pumping means (P) toward the supercooling means (42) is returned by the return pipe (49).
Returned upstream of (P). Therefore, when ice is contained in the heat storage medium, the ice can be flown again upstream of the pumping means (P) before being introduced into the supercooling means (42). This ice can be melted before it is introduced into the supercooling means (42) due to an internal stirring action or the like.

According to a second aspect of the present invention, in the ice heat storage device according to the first aspect, a heating means for heating the heat storage medium pumped from the pumping means (P) downstream of the pumping means (P).
(40) is provided. The upstream end of the return pipe (49) is connected to the downstream side of the heating means (40).

With this configuration, the heat storage medium pumped from the pumping means (P) is heated by the heating means (40), and the melting of ice in the heat storage medium is promoted. Then, a part of the heated heat storage medium is supplied by a return pipe (49) by a pumping means.
After being returned to the upstream side of (P), it is heated again by the heating means (40), and the melting of ice is further promoted. In the apparatus, a pipe (45A) connecting the heating means (40) and the supercooling means (42) is connected to a first pipe (45a) upstream of a connection position of the return pipe (49) and a first pipe (45a) downstream. It consists of two pipes (45b).
The passage area of the second pipe (45b) is substantially equal to the passage area of the return pipe (49).

With this configuration, about half of the heat storage medium that has been pressure-fed from the pressure feeding means (P) and has flowed through the first pipe (45a) is supplied to the supercooling means (42), and the other half is supplied to the pressure feeding means (P). Will be flown to the upstream side respectively. That is, the actual circulation amount in the heat storage circulation circuit (B) is set to about half of the pumping amount of the pumping means (P).

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a refrigerant circuit (A) provided in an ice storage type air conditioner according to this embodiment. FIG. 2 shows a water circulation circuit as a heat storage circulation circuit.
(B) is shown.

The refrigerant circuit (A) includes a compressor (1), an outdoor heat exchanger (3), a first outdoor electric expansion valve (5), and a subcooling system comprising a vertical shell and tube heat exchanger. A supercooling heat exchanger (42) as a means, a second outdoor electric expansion valve (52a), a preheater (40) comprising a double-pipe heat exchanger, and an indoor electric expansion valve (6)
And an indoor heat exchanger (7) are connected by a refrigerant pipe (8). The compressor (1) is operated by the four-way switching valve (2).
With the discharge side connected to the outdoor heat exchanger (3) and the suction side connected to the indoor heat exchanger (7) (the state shown by the solid line in FIG. 1)
And a state in which the discharge side of the compressor (1) is connected to the indoor heat exchanger (7) and the suction side is connected to the outdoor heat exchanger (3) (the state shown by the broken line in FIG. 1). Has become.

Further, first and second three-way solenoid valves are provided at two places between the first outdoor electric expansion valve (5) and the heat storage heat exchanger (42).
(CRV-1, CRV-2). Each solenoid valve (CRV-1, CRV
Explaining -2), the first three-way solenoid valve (CRV-1) located on the side of the first outdoor electric expansion valve (5) has the first port (P-1) of the three ports connected to the outdoor heat exchanger. On the (3) side, the second port (P-2) is on the second three-way solenoid valve (CRV-2) side, and on the third port (P-2).
-3) are connected between the preheater (40) and the indoor electric expansion valve (6) via the first bypass pipe (8a). The second three-way solenoid valve (CRV-2) located on the side of the heat storage heat exchanger (42)
The first port (P-1) of the three ports is the first three-way solenoid valve
On the (CRV-1) side, the second port (P-2) is on the heat storage heat exchanger (42) side, and the third port (P-3) is on the indoor heat exchanger via the second bypass pipe (8b). Each is connected between (7) and the four-way switching valve (2).

Next, the water circulation circuit (B) according to this embodiment will be described. As shown in FIG. 2, the water circulation circuit (B) according to the present embodiment includes a heat storage tank (T), a pump as a pumping means.
(P), preheater (40) as heating means, subcooling heat exchanger (4
2) and the supercooler (43) are connected in order by a water pipe (45) so that water circulation (see solid arrows in FIG. 2) is possible. Further, an ice nucleus generator (46) is provided integrally with the subcooling canceller (43). The ice nucleus generator (46) removes part of the refrigerant flowing through the refrigerant pipe (8) (for example, part of the refrigerant depressurized by the second outdoor electric expansion valve (52a)) during a cold heat storage operation described later. Introduced this refrigerant and supercooler
By exchanging heat with the water in (43), the water is cooled to generate ice nuclei in the form of small particles, and the operation of eliminating supercooling of the supercooled water is performed around the ice nuclei. In other words, the supercooler (43)
Inside, the formation of ice nuclei and the elimination of supercooling are both performed.

Further, a preheater (40) and a supercooling heat exchanger (42)
In this configuration, heat exchange is performed between the refrigerant in the refrigerant circuit (A) and the water in the water circuit (B). For more information,
The preheater (40) is a heat exchanger having a double tube structure as described above, and water flows inside the double tube and refrigerant flows outside the double tube, so that heat can be exchanged between the two. Subcooling heat exchanger (4
In (2), a plurality of heat transfer tubes (42b) are provided in a casing, water flows inside the heat transfer tubes, and the refrigerant flows in a space outside the space (42a) in a full state. Heat tube (42b)
Heat can be exchanged between the two via the wall surface.

Incidentally, (48) in FIG. 2 is a subcooling heat exchanger.
Supercooler (43) and heat storage tank for water flowing out of (42)
This is a bypass pipe that bypasses (T) and upstream of the pump (P). A three-way switching valve (CRV), which is a proportional control valve, is provided at a portion of the bypass pipe (48) connected to the water pipe (45) at the downstream end. This three-way switching valve (CRV) connects the upstream side of the pump (P) with the heat storage tank (T).
And a second switching state communicating with the bypass pipe (48) (a switching state bypassing the subcooling canceller (43) and the heat storage tank (T)). I have.

As a feature of this embodiment, a preheater (40)
A return pipe (49) is provided for returning a part of the water flowing out of the pump to the upstream side of the pump (P). The return pipe (49) has an upstream end located between the preheater (40) and the supercooling heat exchanger (42).
The downstream end is connected between the connection position of the downstream end of the bypass pipe (48) in the water pipe (45) and the pump (P). A water pipe (45A) connecting the preheater (40) and the subcooling heat exchanger (42) is connected to a first pipe (45a) upstream of the connection position of the return pipe (49) and a downstream pipe. And the second pipe (45b). The flow path area of these pipes (45a, 45b) and return pipe (49) will be described.
And the flow path area of the return pipe (49) are set to be substantially the same. The flow passage area of the first pipe (45a) is substantially equal to the sum of the flow passage area of the second pipe (45b) and the flow passage area of the return pipe (49). With this, the preheater (40)
Water flowing out of the first pipe (45a) and flowing through the second pipe (45a).
b) and the return pipe (49) is almost equally diverted. That is, about half of the water flowing out of the preheater (40) is returned to the upstream side of the pump (P) by the return pipe (49).

In order to obtain the above-described water circulation state and the refrigerant circulation state as in each operation described later, an electromagnetic valve is provided as necessary, or the pipe diameter of each pipe is reduced. Is set.

-Operation- Next, the operation of the air conditioner configured as described above will be described. The operation modes of the present air conditioner include a normal cooling operation, a cold storage operation, a thawing operation, and a cooling operation using cold storage.

Hereinafter, the refrigerant circulation operation in each operation mode will be described.

-Normal Cooling Operation- During the normal cooling operation, the four-way switching valve (2) is switched to the solid line side in FIG. 3, and the first three-way solenoid valve (CRV-1) is connected to the first port.
(P-1) is switched to the third port (P-3). In addition, the first outdoor electric expansion valve (5) is controlled to a fully opened state, and the indoor electric expansion valve (6) is controlled to a predetermined opening (the indoor heat exchanger (7)).
The superheat degree control at the outlet side is performed.

When the compression mechanism (1) is driven in this state, the refrigerant discharged from the compressor (1) passes through the four-way switching valve (2) and passes through the outdoor heat exchanger (3) as shown by an arrow in FIG. ), And exchanges heat with the outside air in the outdoor heat exchanger (3) to condense. Thereafter, the refrigerant is supplied to the first bypass pipe (8
After a), the pressure is reduced by the indoor electric expansion valve (6), and heat is exchanged with the indoor air in the indoor heat exchanger (7) to evaporate and cool the indoor air. Then, this gas refrigerant is returned to the suction side of the compressor (1) via the four-way switching valve (2). By performing such a circulation operation of the refrigerant, indoor cooling is performed.

-Cold heat storage operation- In this cold heat storage operation, in the water circulation circuit (B), a three-way solenoid valve (CRV) connects the upstream side of the pump (P) to the heat storage tank (T).
In a first switching state. And the pump
(P) is driven to circulate water in the water circulation circuit (B) (see the arrow indicated by the solid line in FIG. 2). On the other hand, the refrigerant circuit
In (A), the four-way switching valve (2) switches to the solid line side in FIG.
The first three-way solenoid valve (CRV-1) is in a switching state in which the first port (P-1) and the third port (P-3) are connected, and the second three-way solenoid valve (CRV-2) is in the switching state. 2 port (P-2) and 3rd port (P-
3) A switching state is established to communicate with. The second outdoor electric expansion valve (52a) is controlled to a predetermined opening. The indoor electric expansion valve (6) is fully closed, and the first outdoor electric expansion valve (5) is closed.
Is fully opened. As a result, as indicated by the arrow in FIG. 4, the refrigerant discharged from the compressor (1) is supplied to the four-way switching valve.
It is introduced into the outdoor heat exchanger (3) via (2), and heat exchanges with the outside air in the outdoor heat exchanger (3) to condense.
Thereafter, the refrigerant is introduced into the preheater (40) through the first bypass pipe (8a), and heats the water circulating in the water circulation circuit (B). Thereafter, the pressure of the refrigerant is reduced by the second outdoor expansion valve (52a). Then, the low-pressure refrigerant is introduced into the supercooling heat exchanger (42), performs heat exchange with water,
Cool the water and evaporate. Thereafter, the evaporated gas refrigerant is returned to the suction side of the compressor (1) via the second bypass pipe (8b).

The feature of the present embodiment resides in the water circulation operation in the water circulation circuit (B) in the cold heat storage operation. Hereinafter, the water circulation operation will be described. The water extracted from the heat storage tank (T) as the pump (P) is driven is introduced into the preheater (40) via the pump (P), where heat is exchanged with the refrigerant to obtain the temperature. Rises. As a result, even if ice is mixed in the water taken out of the heat storage tank (T), the melting of the ice is promoted.
Then, water derived from the preheater (40) is supplied to the first pipe (4
After passing through 5a), it is divided into the second pipe (45b) and the return pipe (49). Then, the water flowing through the return pipe (49) flows again upstream of the pump (P), is mixed with water derived from the heat storage tank (T), and is introduced into the pump (P).
At this time, the water and ice are stirred by the stirring action in the pump (P), and the melting of the ice is promoted here as well. Then, the water derived from the pump (P) is again introduced into the preheater (40), and the temperature rises. Since such an operation is repeatedly performed on the upstream side of the subcooling heat exchanger (42),
The amount of ice in the water introduced into the supercooling heat exchanger (42) can be extremely small, or almost no ice can be obtained.

Thereafter, the water introduced into the subcooling heat exchanger (42) is cooled to a supercooled state,
Supercooling is eliminated around the ice nuclei generated by the ice nucleus generator (46) in the step (3), and the ice is turned into a slurry. This ice is
It is sent from the supercooling elimination section (43) to the heat storage tank (T) and stored in the heat storage tank (T) as a cold heat source.

-Thawing operation-In the above-mentioned cold heat storage operation, when the supercooling heat exchanger (42) is free from supercooling of water in the supercooling heat exchanger (42), This cold storage operation is temporarily interrupted and switched to the thawing operation. In this thawing operation, the refrigerant circulation circuit
In (A), the four-way switching valve (2) switches to the broken line side in FIG.
The second three-way solenoid valve (CRV-2) is in a switching state for communicating the third port (P-3) and the second port (P-2), and the first three-way solenoid valve (CRV-1) is 3 ports (P-3) and 1st port (P-
1) A switching state is established to communicate with. When the second outdoor electric expansion valve (52a) is fully opened, the first outdoor electric expansion valve is opened.
(5) is controlled to a predetermined opening degree (constant superheat degree control on the outlet side of the outdoor heat exchanger (3)). As a result, as shown by the arrow in FIG. 5, the refrigerant discharged from the compressor (1)
(8b) and the second three-way solenoid valve (CRV-2)
(42) is introduced into the subcooled heat exchanger (42)
Thaw the ice inside. Then, the refrigerant is returned to the suction side of the compressor (1) through the preheater (40), the first bypass pipe (8a), the first three-way solenoid valve (CRV-1), and the outdoor heat exchanger (3). It becomes a circulation state.

On the other hand, in the water circulation circuit (B), the three-way solenoid valve (CRV) is operated simultaneously with or before the supply of the discharged refrigerant (hot gas) to the subcooling heat exchanger (42). The first switching state is switched to the second switching state.

The three-way solenoid valve (CRV)
Is switched to the second switching state, the circulating water flows by bypassing the supercooling canceller (43) and the heat storage tank (T) (see the arrow shown by the broken line in FIG. 2), and the heat storage tank
The supply and discharge of water to (T) is not performed, and the ice in the subcooling heat exchanger (42) is efficiently melted.

-Cooling operation utilizing cold storage-In this operation mode, indoor cooling is performed while utilizing the cold heat of ice stored in the heat storage tank (T) in the above-described cold storage operation.

In the cooling operation utilizing the cold storage heat, in the water circulation circuit (B), the pump (P) is driven to operate the water circulation circuit (B).
Water circulates in (B). At this time, a three-way solenoid valve (CRV)
Is in a first switching state in which the upstream side of the pump (P) communicates with the heat storage tank (T). On the other hand, in the refrigerant circuit (A), the four-way switching valve (2) is switched to the solid line side in FIG. 6, and the first three-way solenoid valve (CRV-1) is connected to the first port (P-1) and the second port. Port (P
-2) is switched to communicate with the second three-way solenoid valve.
(CRV-2) is in a switching state in which the first port (P-1) and the second port (P-2) communicate with each other. Also, the indoor electric expansion valve
(6) is a predetermined opening degree, and the first outdoor electric expansion valve (5) and the second outdoor electric expansion valve (52a) are fully opened. This allows
As shown by the arrows in FIG. 6, the refrigerant discharged from the compressor (1) is introduced into the outdoor heat exchanger (3) via the four-way switching valve (2), where it is passed through the outdoor heat exchanger (3). Condenses by performing heat exchange with the outside air. This refrigerant is then passed to a subcooling heat exchanger
It is introduced into (42) and cooled by the cold water circulating in the water circulation circuit (B). Then, after the refrigerant is decompressed by the indoor electric expansion valve (6), the refrigerant exchanges heat with the indoor air in the indoor heat exchanger (7) to evaporate, cools the indoor air, and then cools the compressor ( It is returned to the suction side of 1).

The refrigerant circulation operation in each operation mode as described above is performed.

As described above, according to the present embodiment, during the cold storage operation, a part of the water flowing out of the preheater (40) is pumped (P).
By returning to the upstream side of the subcooling heat exchanger (42)
Since the inflow of ice into the water is suppressed, the freezing of the supercooling heat exchanger (42) can be suppressed, and a stable ice making operation can be performed. In other words, the thawing operation frequency can be reduced only by providing one pipe such as the return pipe (49), and the ice making operation efficiency can be improved with a simple configuration.

In each of the embodiments, water is used as the heat storage medium for heat storage. However, a brine solution or the like may be used.

Although the case where the present invention is applied to an ice heat storage device for an air conditioner has been described, the present invention is also applicable to other devices utilizing cold storage heat.

[0038]

As described above, according to the present invention, the following effects can be obtained. According to the first aspect of the present invention, the heat storage medium taken out from the heat storage tank is pressure-fed to the supercooling means by the pressure feeding means to be in a supercooled state, and the supercooled state is eliminated to generate a slurry-like ice. For the apparatus, since a return pipe is provided to return a part of the heat storage medium pumped from the pumping means toward the supercooling means to the upstream side of the pumping means, ice is contained in the heat storage medium taken out from the heat storage tank. In this case, the melting of the ice by the stirring action or the like inside the pumping means is repeated again, so that the ice can be melted before being introduced into the supercooling means. Therefore, freezing of the supercooling means can be suppressed, a stable ice making operation can be performed, and the ice making operation efficiency can be improved with a simple configuration.

According to the second aspect of the present invention, the heating means for heating the heat storage medium is provided downstream of the pressure feeding means, and the heat storage medium derived from the heating means is returned to the upstream side of the pressure feeding means. The heat storage medium can be circulated through the heating means a plurality of times, so that the melting of the ice can be further promoted, and the reliability of avoiding freezing of the supercooling means can be improved.

According to the third aspect of the invention, since about half of the heat storage medium led out of the heating means is returned to the upstream side of the pumping means (P), it is sufficient to melt the ice in the heat storage medium. A large amount of reconstitution can be obtained, and the ice can be reliably melted.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a refrigerant circulation circuit provided in an air conditioner according to an embodiment.

FIG. 2 is a diagram showing a configuration of a water circulation circuit.

FIG. 3 is a circuit diagram showing a refrigerant circulation operation in a normal cooling operation.

FIG. 4 is a circuit diagram showing a refrigerant circulation operation of the cold storage operation.

FIG. 5 is a circuit diagram showing a refrigerant circulation operation of a thawing operation.

FIG. 6 is a circuit diagram showing a refrigerant circulation operation in a cooling operation utilizing cold storage heat.

[Explanation of symbols]

 (40) Preheater (heating means) (42) Subcooling heat exchanger (supercooling means) (45,45A) Water pipe (circulation pipe) (45a) First pipe (45b) Second pipe (49) Return pipe (B) Water circulation circuit (heat storage circuit) (T) Heat storage tank (P) Pump (pumping means)

Claims (3)

[Claims] 1. A heat storage tank (T) capable of storing a heat storage medium.
And the pumping means (P) and the supercooling means (42)
A heat storage circuit (B) is connected in order so that the heat storage medium can be circulated by the heat storage medium, and the liquid-phase heat storage medium taken out of the heat storage tank (T) is supercooled by a pressure-feeding means (P). ) And cooled to a supercooled state in the supercooling means (42), and after being led out from the supercooling means (42), the supercooled state is eliminated to produce slurry ice. In the ice heat storage device for collecting and storing the ice in the heat storage tank (T), the upstream side and the downstream side of the pumping means (P) are connected, and the supercooling means (42) is connected to the pumping means (P). )) Is provided with a return pipe (49) for returning a part of the heat storage medium pumped toward the upstream side of the pumping means (P). 2. The ice heat storage device according to claim 1, wherein: Downstream of the pumping means (P), heating means (40) for heating the heat storage medium pumped from the pumping means (P) is provided,
An ice heat storage device, wherein an upstream end of the return pipe (49) is connected to a downstream side of the heating means (40). 3. A pipe (45A) for connecting a heating means (40) and a supercooling means (42) in the ice heat storage device according to claim 2.
Is the first pipe (4) upstream of the connection position of the return pipe (49).
5a) and a downstream second pipe (45b), wherein the flow area of the second pipe (45b) and the flow area of the return pipe (49) are substantially the same. apparatus.