JPH10267329A - Ice heat storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a COP based on reduction of input to a compressor for a freezer device in which cold heat stored in a heat reservoir is utilized to perform an indoor cooling operation or the like. SOLUTION: An apparatus having a refrigerant circulating circuit A and a water circulating circuit B in which water is cooled at a supercooling water generating heat exchanger 20 to make a supercooled state, and this supercooled state is released to make ice is constructed such that the refrigerant circulating circuit A is provided with two compressors COMP-1 and COMP-2. During an operation utilizing cold heat, discharged refrigerant flowed out of a high pressure side compressor COMP-1 is condensed by an outdoor heat exchanger 3 and its pressure is reduced to a predetermined pressure by an expansion valve EV-1. In turn, the discharged refrigerant flowed out of a low pressure side compressor COMP-2 is bypassed the outdoor heat exchanger 3 and flowed. These refrigerants are merged and supplied to a pre-heater 21. At this pre-heater 21, cold heat of the water circulating circuit B is given to the merged refrigerant, resulting in that the refrigerant becomes a supercooled state. This refrigerant is supplied to the indoor heat exchanger 6 and contributed to an indoor cooling operation.

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, and more particularly to ice storage by cooling a heat storage medium such as water or an aqueous solution, and storing the ice as a cold heat source. The present invention relates to an improvement of an apparatus for performing indoor cooling or the like by using a computer.

[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. It is also known that slurry-like ice for use as cooling heat at the time of peak cooling load is generated during off-peak cooling load and stored in a heat storage tank.

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

[0004] In the ice making operation of the ice heat storage device, water taken out of the heat storage tank exchanges heat with the refrigerant in the water heat exchange unit in the supercooled water generation unit and is cooled to a supercooled state. Eliminates the supercooled state and produces slurry ice. This ice is supplied to a heat storage tank and stored as a cold heat source.

[0005] During the cooling operation using cold energy, the refrigerant discharged from the compressor is condensed by the cold heat of ice or the outside air, and this liquid refrigerant is supplied to the indoor unit. In the indoor unit, after the pressure of the liquid refrigerant is reduced, the liquid refrigerant evaporates by performing heat exchange with indoor air. This allows
The room will be cooled.

[0006]

By the way, in this type of ice heat storage device, there is a demand that the input of the compressor during the cooling operation utilizing the cold heat be reduced as much as possible to improve the COP.

[0007] However, the conventional ice heat storage device has not been improved in this respect, and the compressor input must be increased in order to exert a sufficient refrigeration capacity.
There was a limit to the improvement of OP.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has been described in which a compressor input is provided to a refrigeration system that performs indoor cooling operation or the like by utilizing cold stored in a heat storage tank or the like. It is intended to improve the COP by reducing it.

[0009]

In order to achieve the above object, the present invention comprises two compressors, and condenses a high-pressure refrigerant among the refrigerant discharged from each compressor by, for example, outside air.
A so-called two-temperature condensation, in which the refrigerant and the low-pressure refrigerant are combined and supercooled by cold storage heat, is performed.

[0010] Specifically, the invention according to claim 1 is a heat storage tank.
(T) and a heat storage medium circulating circuit (B) in which a heat storage medium is circulated so that a heat storage medium can be circulated, a compressor (1), a heat source side heat exchange means (3), and the heat storage supply section (B). 21B), a refrigerant circulation circuit (A) in which a heat storage heat receiving section (21A) capable of exchanging heat with the use side decompression means (EV-3), and a use side heat exchanger (6) are connected so that refrigerant can circulate. ). During cold-heat utilization operation in which the use-side heat exchange means (6) absorbs heat using the cold stored in the heat storage tank (T), the refrigerant circulating in the refrigerant circuit (A) is stored in the heat storage heat receiving section (21A). It is premised on an ice heat storage device that is cooled by the heat storage medium of the supply section (21B) and supplies the refrigerant to the use-side heat exchange means (6). The above compressor
(1) The high-pressure compressor (COMP-1) and the low-pressure compressor (COMP-2)
And When using cold heat, the high-pressure side compressor (COMP-
The refrigerant discharged from 1) is supplied to the heat source side heat exchange means (3) and condensed, while the refrigerant discharged from the low pressure side compressor (COMP-2) is exchanged by the bypass pipes (8, 9). Means (3) are bypassed and flowed, and these refrigerants are combined and heat storage heat receiving section (21A)
Then, the pressure is reduced by the use side decompression means (EV-3) and supplied to the use side heat exchange means (6).

According to this specific matter, in the refrigerant circulation operation at the time of the cold heat utilization operation, the refrigerant discharged from the high pressure side compressor (COMP-1) is first condensed by the heat source side heat exchange means (3). Thereafter, the refrigerant merges with the refrigerant discharged from the low-pressure side compressor (COMP-2) and the heat storage supply unit (21B) in the heat storage heat receiving unit (21A).
To be in a supercooled state. That is,
The high pressure side compressor (COMP-1) is cooled by both the heat source side heat exchange means (3) and the heat storage heat receiving section (21A). In this case, even if the pressure of the refrigerant discharged from the low-pressure side compressor (COMP-2) is low, a sufficient refrigerating capacity can be exhibited in the entire apparatus, and the input of the compressor (1) as a whole can be reduced.

According to a second aspect of the present invention, in the ice heat storage device of the first aspect, a decompression means (EV-1) is provided downstream of the heat source side heat exchange means (3). During the operation using cold heat, the refrigerant condensed by the heat source side heat exchange means (3) is depressurized to the refrigerant pressure in the bypass pipes (8, 9) by the decompression means during cold use (EV-1), and then the bypass pipe is used. It is made to merge with the refrigerant of (8, 9).

According to this specific matter, the refrigerant pressures of both refrigerants coincide at the merging portion of each refrigerant, and this merging operation is performed smoothly.

According to a third aspect of the present invention, in the ice heat storage device of the second aspect, the downstream side of the heat source side heat exchange means (3) is branched into branch pipes (11A, 11B), and the decompression means at the time of utilizing cold heat. (EV-
1) is installed in one branch pipe (11A). The switching means (SV-) switches to the first switching state during the heat absorbing operation in which the heat is absorbed by the use side heat exchange means (6) without using the cold heat of the heat storage tank (T), and to the second switching state during the cooling heat utilization operation. 13, EV-1). In the first switching state, the switching means (SV-13, EV-1) condenses the refrigerant discharged from the compressor (1) by the heat source side heat exchange means (3), and condenses the other branch pipe (11B ) And bypass the decompression means (EV-1) when using cold
(EV-3) and the user side heat exchanger (6). In the second switching state, the refrigerant discharged from the high pressure side compressor (COMP-1) is condensed by the heat source side heat exchange means (3), and the one branch pipe (11A)
The refrigerant is decompressed by the decompression means (EV-1) when utilizing cold heat, and this refrigerant merges with the refrigerant discharged from the low-pressure side compressor (COMP-2) and is supplied to the heat storage heat receiving unit (21A). I have.

According to this specific matter, the switching means (SV-13, E
By the switching operation of V-1), it is possible to switch between a state in which the refrigerant flows into the pressure reducing means (EV-1) during cold use and a state in which the refrigerant does not flow according to the operating state.

According to a fourth aspect of the present invention, in the ice heat storage device according to the second aspect, the pressure reducing means (EV-1) at the time of utilizing cold energy includes:
During the heat dissipation operation in which the refrigerant discharged from the compressor (1) is supplied to the use-side heat exchange means (6) and heat is radiated by the use-side heat exchange means (6), the refrigerant is condensed by the use-side heat exchange means (6). The pressure reducing unit that reduces the pressure of the refrigerant and guides the refrigerant to the heat source side heat exchange means (3) is also used.

According to this specific matter, means for depressurizing the refrigerant during the cold-heat utilization operation and means for depressurizing the refrigerant during the heat-dissipation operation are also used. The operation according to the first aspect of the present invention can be obtained.

[0018]

Next, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a case where the device according to the present invention is applied to an ice regenerative air conditioner will be described.

FIG. 1 shows the overall configuration of a refrigerant circuit (A) and a water circuit (B) as a heat storage medium circuit provided in the ice storage type air conditioner according to the present embodiment. As shown in this figure, in this air conditioner, the outdoor unit (X) and the indoor unit (Y, Y, Y) are connected by a communication refrigerant pipe (RL, RG), and the outdoor unit (X) is a heat storage tank. (T) water pipe
(WS, WR). In other words, the outdoor unit
(X) and each indoor unit (Y, Y, Y)
(A) The liquid-side and gas-side communicating refrigerant pipes (RL,
RG), the outdoor unit (X) and the heat storage tank (T) are connected to each other by connecting water pipes (WS, WR) on the supply side and the recovery side which constitute a part of the water circulation circuit (B).

Hereinafter, a refrigerant circuit (A) and a water circuit will be described.
(B) will be described. -Explanation of refrigerant circulation circuit- First, the configuration of the refrigerant circulation circuit (A) will be described. The refrigerant circulation circuit (A) includes an outdoor unit as a heat source side heat exchanger in which a compression mechanism (1), a four-way switching valve (2), and an outdoor fan (F) provided in the outdoor unit (X) are arranged in close proximity. Heat exchanger (3), receiver (4), first and second outdoor electric expansion valves (EV-1, EV-
2), accumulator (5), indoor electric expansion valves (EV-3, EV-3, EV-3) provided in each indoor unit (Y, Y, Y), and indoor heat exchangers (6, 6, 6) ).

A gas-side pipe (10) is provided at one end of the outdoor heat exchanger (3) on the gas side, and a liquid-side pipe is provided at the other end of the outdoor heat exchanger (3).
(11) are connected respectively.

The gas side pipe (10) is switchably connected to the discharge side and the suction side of the compression mechanism (1) via a four-way switching valve (2). That is, the gas side pipe (10) is connected to the first discharge gas line (10a) connecting the discharge side of the compression mechanism (1) and the four-way switching valve (2), the four-way switching valve (2) and the outdoor heat source. Exchanger (3)
The second discharge gas line (10b) connecting the
A suction gas line (10c) is provided for connecting the suction mechanism (2) to the suction side of the compression mechanism (1).

On the other hand, the liquid side pipe (11) is connected to the outdoor heat exchanger (3).
And a refrigerant passage (21A) of a preheater (21) described later. The liquid-side pipe (11) has a first check valve (CV-C) that allows only the refrigerant flow from the outdoor heat exchanger (3) to the preheater (21).
1) The receiver (4) is provided.

The downstream side of the receiver (4) is branched into first and second branch pipes (11A, 11B). The first branch pipe (11A) has a first outdoor electric expansion valve (EV-1), and a second branch pipe (11A) that allows only a refrigerant flow from the first outdoor electric expansion valve (EV-1) to the preheater (21). Two check valves (CV-2) are provided. 1st branch pipe (1
1A) is provided with a first solenoid valve (SV-1). The downstream ends of the branch pipes (11A, 11B) are joined and extend toward the refrigerant passage (21A) of the preheater (21).

One end of a third branch pipe (11C) is connected between the outdoor heat exchanger (3) and the first check valve (CV-1). Third
The other end of the branch pipe (11C) is connected between the first outdoor electric expansion valve (EV-1) and the second check valve (CV-2) in the first branch pipe (11A). The third branch pipe (11C) is provided with a third check valve (CV-3) that allows only the refrigerant flow from the first branch pipe (11A) to the liquid side pipe (11).

Each of the indoor expansion valves (EV-3, EV-3, EV-3)
Is connected to each indoor heat exchanger (6, 6a, 6a, 6a, 6a)
6,6) are connected respectively to the liquid side.

The liquid side communication refrigerant pipe (RL) is connected to the indoor liquid pipe (11a, 1
1a, 11a) to the indoor electric expansion valves (EV-3, EV-3, EV-3). This liquid side communication refrigerant pipe (RL) is connected to the liquid pipe (11b)
Via the receiver (4) of the liquid side pipe (11) and the first check valve
(CV-1). The liquid pipe (11b) is provided with a second solenoid valve (SV-2).

The gas side communication refrigerant pipe (RG) is connected to the gas side of each indoor heat exchanger (6, 6, 6) via a plurality of indoor gas pipes (6b, 6b, 6b). This gas side communication refrigerant pipe (RG) is connected to a four-way switching valve (2) via a gas pipe (10d), and is connected to the discharge side of the compression mechanism (1) by the four-way switching valve (2). It is switchably connected to the suction side.

The compression mechanism (1) has a first compressor (COMP-1) with an unloader mechanism, which is controlled to be switched between three stages of full load, unload and stop, and has an inverter-controlled multi-stage capacity control. Variable capacity second compressor (COMP
-2) are connected in parallel to form a so-called twin type.

First discharge gas line (10a) and liquid side pipe (11)
Are connected by a supply pipe (8). This supply pipe (8)
Is branched into a plurality of (three) branch pipes on the way, and each of the branch pipes is provided with third to fifth solenoid valves (SV3 to SV5). Two of the three branch tubes are provided with capillary tubes (CP, CP). This supply pipe (8) and the second
The discharge side of the compressor (COMP-2) is connected by a bypass pipe (9). The connection position of the bypass pipe (9) to the supply pipe (8) is between the connection position of the supply pipe (8) to the liquid side pipe (11) and each of the solenoid valves (SV3 to SV5). Bypass pipe
(9) is provided with a sixth solenoid valve (SV-6). By these supply pipe (8) and bypass pipe (9), the second compressor (COMP-2)
The bypass pipe referred to in the present invention is configured to flow the refrigerant discharged from the air bypassing the outdoor heat exchange means (3).

The present apparatus comprises a supercooled water generating heat exchanger (20) and a preheater (21) for exchanging heat between the refrigerant flowing in the refrigerant circuit (A) and the water flowing in the water circuit (B). ). Hereinafter, the supercooled water generating heat exchanger (20) and the preheater (2
1) will be described.

The supercooled water generating heat exchanger (20) is a shell-and-tube heat exchanger, and includes a plurality of heat transfer tubes (20B) extending in a vertical direction inside a cylindrical body. And the water of the water circulation circuit (B) is placed inside the heat transfer tube (20B).
The refrigerant in the refrigerant circulation circuit (A) flows to the outside (20A), and exchanges heat with each other. For example, during cold heat storage operation, water is cooled to a supercooled state. Meanwhile, preheater (21)
Is a heat exchanger with a double tube structure, inside the inner tube (21B)
Water in the water circulation circuit (B) and the refrigerant circulation circuit to the outside (21A)
The refrigerant of (A) flows and performs heat exchange with each other.

The configuration of the refrigerant pipe for supplying and recovering the refrigerant to and from the supercooled water generating heat exchanger (20) and the preheater (21) will be described below.

First, in the supercooled water generating heat exchanger (20), the lower part of the side surface of the cylinder is connected to the liquid pipe (11b) by the liquid side connection pipe (12).
Connected to The liquid-side connection pipe (12) is provided with the second outdoor electric expansion valve (EV-2). In the liquid connection pipe (12), a seventh solenoid valve (SV-7) is connected in series to the second outdoor electric expansion valve (EV-2). An eighth solenoid valve (SV-8) is connected in parallel to the second outdoor electric expansion valve (EV-2) and the seventh solenoid valve (SV-7). Further, in the liquid side connection pipe (12), a part is branched, and the
(SV-9) and a tenth solenoid valve (SV-10) on the other side. Also, the liquid piping (11
An eleventh solenoid valve (SV-11) is provided near the connection position to b).

The liquid-side connection pipe (12) and the liquid-side pipe (11) are connected by first and second bypass pipes (13, 14). One end of the first bypass pipe (13) has a liquid side connection pipe (1).
It is connected between the seventh solenoid valve (SV-7) and the ninth solenoid valve (SV-9) in 2). The other end is connected between the receiver (4) and the first check valve (CV-1) in the liquid side pipe (11).
The first bypass pipe (13) is provided with a twelfth solenoid valve (SV-12).

One end of the second bypass pipe (14) has a liquid side pipe.
The second branch pipe (11B) of (11) is connected to the upstream side of the first solenoid valve (SV-1). The other end is connected between the ninth solenoid valve (SV-9) and the eleventh solenoid valve (SV-11) in the liquid side connection pipe (12). The second bypass pipe (14) is provided with a thirteenth solenoid valve (SV-13).

The upper part of the side surface of the cylinder of the supercooled water generating heat exchanger (20) is connected to the suction gas line (10c) by the gas side connection pipe (15).

The preheater (21) has one end of the refrigerant passage (21A) connected to the liquid side pipe (11). On the other hand, this refrigerant passage (21A)
Is connected to the liquid side connection pipe (12) by a recovery pipe (16). The collection pipe (16) is composed of a first collection pipe (16A) and a second collection pipe.
(16B). The first recovery pipe (16A) is connected between the second outdoor electric expansion valve (EV-2) and the seventh solenoid valve (SV-7) in the liquid side connection pipe (12), and has a fourteenth solenoid valve. (SV-1
4) The second recovery pipe (16B) is connected to the liquid side connection pipe (1
It is connected between the seventh solenoid valve (SV-7) and the ninth solenoid valve (SV-9) in 2) and includes a fifteenth solenoid valve (SV-15).

-Description of Water Circulation Circuit- Next, the configuration of the water circulation circuit (B) will be described. The water circulation circuit (B) includes the above-described heat storage tank (T), a preheater (21)
Water passage (21B) and the heat transfer tube (20
B) In addition to the internal water passage, a pump as a transport means (P)
, A growth prevention unit (25), an ice nucleation unit (26), and a supercooling elimination container (27). For details, heat storage tank (T), pump (P), water passage (21B) of preheater (21), heat transfer tube (20B) of supercooled water generating heat exchanger (20), progress prevention part (25), Ice nucleation unit
(26) and the supercooling elimination container (27) are connected in sequence by a water pipe (30) as a heat storage medium flow pipe so as to circulate water as indicated by an arrow in FIG. As described above, the supercooled water generating heat exchanger (20) and the preheater (21) exchange heat between the refrigerant flowing in the refrigerant circuit (A) and water. Thereby, the refrigerant passage (2) of the preheater (21)
1A) is configured as a heat storage heat receiving unit according to the present invention, and the water passage (21B) of the preheater (21) is configured as a heat storage supplying unit according to the present invention.

The supercooling elimination container (27) is a hollow cylindrical member, into which water is introduced from the tangential direction of the inner peripheral surface of the cylindrical container, whereby the water introduced into the container is swirled. The configuration is as follows.

Next, the configuration of the ice nucleus generating unit (26) will be described. The ice nucleus generating unit (26) generates a minute ice block (hereinafter referred to as an ice nucleus) using a part of the water cooled by the supercooled water generating heat exchanger (20). Is supplied to the subcooling elimination container (27). Specifically, the ice nucleation unit (26) includes a capillary tube (CP) for depressurizing the refrigerant therein, and cools the inner wall surface of the water pipe (30) with the depressurized refrigerant. Then, ice adheres to the inner wall surface to form. Then, a part of the supercooled water flowing around the ice is subjected to a supercooling elimination operation to generate an ice nucleus composed of minute ice particles. Therefore, the ice nucleus is rotated together with the supercooled water in the supercooled elimination container (27) to perform the operation of eliminating the supercooled water.

The progress preventing portion (25) will be described. The progress preventing portion (25) is a water pipe on the upstream side of the ice nucleation portion (26).
By heating (30), the ice adhering to the wall of the ice nucleation part (26) is moved upstream (the supercooled water generating heat exchanger (20)
The ice is melted in the growth preventing part (25) when the ice grows to the side (toward the side). This enables the supercooled water generation heat exchanger
The supercooled water generating heat exchanger (20) is prevented from freezing due to the entry of ice into the (20).

Next, the ice nucleation unit (26) and the progress prevention unit
The configuration of the refrigerant pipe for supplying and recovering the refrigerant to (25) will be described. The ice nucleation unit (26) is a refrigerant supply pipe
(26a) is connected to the liquid side pipe (11) and the refrigerant recovery pipe (26b) is connected to the gas side connection pipe (15). Refrigerant supply pipe (26
The connection position of the liquid side piping (11) in (a) is
It is between the connection position to the preheater (21) of 1) and the first solenoid valve (SV-1). The refrigerant supply pipe (26a) has a 16th solenoid valve
(SV-16) and a capillary tube (CP).

The progress preventing section (25) is connected to the refrigerant supply pipe (26a) of the ice nucleation section (26) by the refrigerant supply pipe (25a).
5b) are connected to the liquid side pipes (11) respectively. The refrigerant supply pipe (25a) is provided with a seventeenth solenoid valve (SV-17) and a capillary tube (CP). The connection position of the refrigerant recovery pipe (25b) to the liquid side pipe (11) is between the connection position of the liquid side pipe (11) to the preheater (21) and the first solenoid valve (SV-1). It is.

(28) in FIG. 1 is a heat exchanger for producing supercooled water.
(20) A thawing tube that supplies a high-temperature refrigerant to the supercooled water generating heat exchanger (20) during thawing operation for melting ice when ice is generated inside. One end of the thawing pipe (28) is connected to the supercooled water generating heat exchanger (20), and the other end is connected to the refrigerant supply pipe (26a) of the ice nucleation unit (26). The thaw tube (28) is provided with an eighteenth solenoid valve (SV-18).

The above-described four-way switching valve (2), each solenoid valve (SV-1)
To SV-18) and each of the electric expansion valves (EV-1, EV-2, EV-3) are controlled to open and close by a controller (not shown). The controller also controls the capacity of each compressor (COMP-1, COMP-2) and the rotation speed of the fan (F) and the pump (P).

-Operation- Next, the operation of the air conditioner configured as described above will be described. The operation modes of the air conditioner include a cold storage operation, a cold storage utilizing cooling operation, a normal cooling operation,
There are a warm storage operation, a warm storage utilizing heating operation, and a normal heating operation.

Table 1 shows the open / closed state of each valve in each operating state.
As shown in FIG. The four-way switching valve in Table 1
The “solid line” indicating the state of (2) indicates a switching state on the solid line side in the figure, and the “dashed line” indicates a switching state on the broken line side in the figure. In the “adjustment” indicating the state of each electric expansion valve (EV-1 to EV-3), the valve opening is adjusted according to the refrigerant circulation state (for example, superheat degree control and water condensation temperature control are performed). . The "adjustment" indicating the state of the third to fifth solenoid valves (SV-3 to SV-5) is performed by controlling the number of valves opened to control the amount of preheating in the preheater (21). Indicates that

[0049]

[Table 1]

Hereinafter, the refrigerant circulation operation in each operation mode will be described. -Cold heat storage operation- In this operation mode, the water in the water circulation circuit (B) is cooled to generate ice, and the ice is stored in the heat storage tank (T) as a cold heat source.

In this operation mode, in the water circulation circuit (B), the pump (P) is driven to circulate water in the water circulation circuit (B). On the other hand, in the refrigerant circuit (A),
The compression mechanism (1) is driven, and a part of the refrigerant discharged from the compression mechanism (1) passes through the four-way switching valve (2) as shown by the solid arrow in FIG. The mixture is introduced into (3), and heat is exchanged with outside air in the outdoor heat exchanger (3) to condense. Thereafter, the liquid refrigerant flows toward the preheater (21) via the first branch pipe (11A) of the liquid side pipe (11). At this time, the liquid refrigerant is reduced to a predetermined pressure by the first outdoor electric expansion valve (EV-1).

On the other hand, the other refrigerant discharged merges with the refrigerant via the supply pipe (8) and is introduced into the preheater (21). Then, the joined refrigerants exchange heat with water in the preheater (21) to be in a supercooled state. At this time, in the preheater (21), when ice flows out of the heat storage tank (T), the ice is melted by the heat of the refrigerant, and the ice is cooled by the supercooled water generating heat exchanger ( It does not flow into 20). That is,
The generation of freezing due to the ice flowing into the supercooled water generating heat exchanger (20) is prevented. Thereafter, the refrigerant is
It flows into the liquid side connection pipe (12) via the recovery pipe (16A).

The liquid refrigerant flowing into the liquid side connection pipe (12)
After the pressure is reduced by the second outdoor electric expansion valve (EV-2), it is introduced into the supercooled water generating heat exchanger (20), and the supercooled water generating heat exchanger (2
0) Heat exchange is performed with the water flowing inside to evaporate and cool the water to a supercooled state (for example, −2 ° C.). This gas refrigerant is recovered to the suction side of the compression mechanism (1) via the gas connection pipe (15) and the suction gas line (10c).

By performing such a circulation operation of water and refrigerant, the supercooled water generated by the supercooled water generating heat exchanger (20) comes into contact with ice nuclei when flowing through the ice nucleus generating section (26). Then, the supercooled state is eliminated, and slurry-like ice for heat storage is generated, collected in the heat storage tank (T) via the supercooled elimination vessel (27), and stored in the heat storage tank (T). Will be.

At this time, a part of the liquid refrigerant flowing through the liquid side pipe (11) is supplied to the ice nucleus generating section (26) through the refrigerant supply pipe (26a) and is used for generating ice nuclei. . The refrigerant that has exchanged heat with water in the ice nucleation unit (26) is recovered by the refrigerant recovery pipe (26b) to the gas-side connection pipe (15). A part of the refrigerant flowing through the refrigerant supply pipe (26a) is supplied to the propagation prevention part (25) by the refrigerant supply pipe (25a) and used for preventing the ice from propagating. The refrigerant that has passed through the progress preventing portion (25) is recovered by the refrigerant recovery pipe (25b) to the liquid side pipe (11).

By performing the above operations continuously, slurry-like ice is continuously generated and stored in the heat storage tank (T).

-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 cold storage operation described above.

In this operation mode, in the water circulation circuit (B), the pump (P) is driven to circulate water in the water circulation circuit (B). Thereby, the cold water cooled by the ice in the heat storage tank (T) circulates in the water circulation circuit (B).
On the other hand, in the refrigerant circuit (A), the compression mechanism (1) is driven. As the driving state of the compression mechanism (1), the discharge pressure of the second compressor (COMP-2) is set smaller than the discharge pressure of the first compressor (COMP-1). As shown by the dashed arrow in FIG. 2, the refrigerant discharged from the first compressor (COMP-1) is introduced into the outdoor heat exchanger (3) through the four-way switching valve (2), and The heat is exchanged with the outside air in the vessel (3) to condense. Thereafter, the refrigerant flows into the first branch pipe (11A) via the receiver (4). This refrigerant is decompressed by the first outdoor electric expansion valve (EV-1), and then flows toward the preheater (21). The degree of pressure reduction of the first outdoor electric expansion valve (EV-1) is determined by the pressure of the refrigerant flowing toward the preheater (21) and the refrigerant flowing through a bypass pipe (9) and a supply pipe (8) described later. The pressure is set to match.

On the other hand, the refrigerant discharged from the second compressor (COMP-2) passes through the bypass pipe (9) and the supply pipe (8) to the liquid side pipe (1).
Merges with the above refrigerant in 1). This combined refrigerant is
The water is introduced into the preheater (21), where it exchanges heat with the cold water circulating in the water circulation circuit (B) to be in a supercooled state. Thereafter, the liquid refrigerant reaches the indoor unit (Y, Y, Y) via the second recovery pipe (16B) and the liquid-side connection pipe (12), and the indoor electric expansion valve (E
(V-3, EV-3, EV-3), then decompressed, then indoor heat exchanger (6, 6, 6)
Evaporates and cools the room air. This gas refrigerant is recovered to the suction side of the compression mechanism (1) via the gas pipe (10d), the four-way switching valve (2), and the suction gas line (10c).

As described above, the indoor cooling operation using the cold heat of the ice stored in the heat storage tank (T) is performed.

FIG. 4 is a Mollier diagram showing a refrigerant circulation state in the refrigerant circulation circuit (A) in the cooling operation utilizing the cold storage heat. In this diagram, point a1 is the discharge section of the first compressor (COMP-1), point a2 is the discharge section of the second compressor (COMP-2), point b is the outlet of the outdoor heat exchanger (3), Point c indicates the refrigerant confluence, d indicates the outlet of the preheater (21), point e indicates the inlet of the indoor heat exchanger (6), and point f indicates the refrigerant state at the suction of the compression mechanism (1). ing.

As can be seen from the Mollier diagram, as in the present embodiment, the discharge pressure of the second compressor (COMP-2) can be reduced while exhibiting a sufficient refrigerating capacity.
The input to the compressor (COMP-2) can be suppressed to contribute to the improvement of COP.

-Normal Cooling Operation- In this operation mode, when the compression mechanism (1) is driven, the refrigerant discharged from the compression mechanism (1) receives a four-way switching valve as shown by a dashed line arrow in FIG. After passing through (2), it is introduced into the outdoor heat exchanger (3), where heat is exchanged with outside air in the outdoor heat exchanger (3) to condense. Thereafter, the refrigerant is supplied to the liquid side pipe (1
1), introduced into the indoor unit (Y, Y, Y) via the second bypass pipe (14) and the liquid-side connection pipe (12), and the indoor electric expansion valves (EV-3, EV-3, E
After the pressure is reduced in V-3), heat is exchanged with the indoor air in the indoor heat exchanger (6, 6, 6) to evaporate and cool the indoor air. This gas refrigerant is supplied to a gas pipe (10d), a four-way switching valve (2),
It is collected at the suction side of the compression mechanism (1) via the suction gas line (10c). By performing such a circulation operation, the room is cooled.

-Heat storage operation- This operation mode is for storing hot water in the heat storage tank (T) as the heat used during the heating operation.

In this operation mode, in the water circulation circuit (B), the pump (P) is driven to circulate water in the water circulation circuit (B). On the other hand, in the refrigerant circuit (A),
The compression mechanism (1) is driven, and the refrigerant discharged from the compression mechanism (1) is supplied to a bypass pipe as shown by a solid line arrow in FIG.
The water (9) flows through the supply pipe (8) and is introduced into the preheater (21), where heat exchange is performed with water in the water circulation circuit (B) to heat and condense the water. Thereafter, the liquid refrigerant is supplied to the second recovery pipe (1
6B), liquid side connection pipe (12), liquid pipe (11b), first branch pipe (11
After the pressure is reduced to a predetermined pressure by the first outdoor electric expansion valve (EV-1) through A), the pressure is introduced into the outdoor heat exchanger (3) through the third branch pipe (11C). And this outdoor heat exchanger (3)
After evaporating by performing heat exchange with the outside air at, the compression mechanism (1) passes through the four-way switching valve (2) and the suction gas line (10c).
Collected on the suction side of By performing such a water and refrigerant circulation operation, the water flowing through the water circulation circuit (B) is
The preheater (21) receives heat from the refrigerant and becomes high-temperature hot water, which is stored in the heat storage tank (T).

-Heating operation using warm heat storage-In this operation mode, the room is heated while utilizing the heat of the warm water stored in the heat storage tank (T) in the warm heat storage operation described above.

In this operation mode, in the water circulation circuit (B), the pump (P) is driven to circulate hot water in the water circulation circuit (B). When the compression mechanism (1) is driven in this state, the refrigerant discharged from the compression mechanism (1) is supplied to the four-way switching valve (2) and the gas pipe (10d) as shown by the broken arrows in FIG.
Through the indoor unit (Y, Y, Y)
At (6,6,6), heat exchange is performed with the room air to condense and heat the room air. Then, this refrigerant is
(11b), a second branch pipe (11B) of the liquid side pipe (11), a second bypass pipe (14), and a liquid side connection pipe (12).
Depressurized in V-2) and introduced into supercooled water generating heat exchanger (20),
Here, heat exchange is performed with hot water to evaporate. afterwards,
The gas is collected on the suction side of the compression mechanism (1) through the gas connection pipe (15) and the suction gas line (10c).

In this manner, the indoor heating operation using the heat of the hot water stored in the heat storage tank (T) is performed.

-Normal Heating Operation- In this operation mode, when the compression mechanism (1) is driven, the refrigerant discharged from the compression mechanism (1) is switched four-way as indicated by a dashed line arrow in FIG. It is introduced into the indoor unit (Y, Y, Y) through the valve (2) and the gas pipe (10d), and the indoor heat exchanger (6,
At 6,6), heat is exchanged with the room air to condense and heat the room air. Thereafter, the refrigerant is supplied to the liquid pipe (1
1b), via the first branch pipe (11A), the first outdoor electric expansion valve (EV-
After the pressure is reduced in 1), heat is exchanged with the outside air in the outdoor heat exchanger (3) to evaporate. After that, four-way switching valve (2)
Then, it is collected at the suction side of the compression mechanism (1) via the suction gas line (10c). The room is heated by performing such a circulation operation.

The air conditioning in the room is performed by each operation as described above.

As described above, according to the air conditioner of the present embodiment, the cooling operation utilizing the cold storage and the first compressor (COMP-1)
The refrigerant discharged from the compressor is condensed in the outdoor heat exchanger (3) and decompressed by the first outdoor electric expansion valve (EV-1).
After merging with the refrigerant discharged from OMP-2), it is introduced into the preheater (21). For this reason, a sufficient refrigerating capacity can be exhibited while keeping the input to the second compressor (COMP-2) low, and the COP can be improved.

Further, only by providing one preheater (21), it is possible to condense the refrigerant at a so-called two temperature and to increase the degree of supercooling of the refrigerant on the first compressor side. Therefore, a sufficient refrigerating capacity can be exhibited without increasing the size of the entire apparatus or complicating the circuit.

In this embodiment, water is used as the heat storage medium for heat storage, but other aqueous brine solutions may be used.

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

The supercooled water generating heat exchanger (20) is not limited to the shell and tube type, but may be a plate type or the like. Also, the preheater (21) is not limited to the double tube type, and may be a plate type or the like.

[0076]

As described above, according to the present invention, the following effects can be obtained. According to the first aspect of the present invention, the high-pressure side compressor (6) is connected to a device that uses the cold heat stored in the heat storage tank (T) to perform the heat absorbing operation in the use side heat exchanger (6). COMP-1) and the low-pressure side compressor (COM
P-2), and at the time of cold heat operation, the high pressure side compressor (COM
The refrigerant discharged from P-1) is supplied to the heat source side heat exchange means (3) and condensed, while the refrigerant discharged from the low pressure side compressor (COMP-2) is supplied to the heat source side by bypass pipes (8, 9). The refrigerant flows by bypassing the heat exchange means (3), and the refrigerants are combined to form a heat storage heat receiving section (21).
After supply to (A), the pressure was reduced by the use-side decompression means (EV-3) and supplied to the use-side heat exchange means (6). For this reason,
The discharged refrigerant is condensed at a so-called two-temperature so that the low-pressure side compressor (C
OMP-2) can exhibit sufficient refrigeration capacity while keeping the input low, and can increase the degree of supercooling of the circulating refrigerant of the high-pressure compressor (COMP-1), thereby improving COP. Can be planned.

According to a second aspect of the present invention, there is provided a heat source side heat exchange means.
Downstream of (3), a decompression means (EV-1) at the time of utilizing cold heat is provided, so that the pressure condensed by the refrigerant condensed by the heat source side heat exchange means (3) is set to the same pressure as the refrigerant to be joined. For this reason,
This refrigerant merging operation is performed smoothly, and the refrigerant circulating operation in the refrigerant circuit (A) is performed well, so that a high refrigerating capacity can be exhibited.

According to a third aspect of the present invention, there is provided a switching means for switching a refrigerant flow in accordance with a heat absorbing operation of the use side heat exchange means (6) which does not utilize the cold heat of the heat storage tank (T) and a cold heat utilization operation.
(SV-1, SV-6). That is, in the heat absorbing operation, the first switching state is established, the refrigerant discharged from the compressor (1) is condensed by the heat source side heat exchange means (3), and the refrigerant is bypassed by the decompression means (EV-1) when utilizing cold heat. Then, it is supplied to the use side decompression means (EV-3) and the use side heat exchanger (6). On the other hand, in the cold-heat utilization operation, the second switching state is established, and the refrigerant discharged from the high-pressure side compressor (COMP-1) is condensed by the heat source side heat exchange means (3), and is branched.
(11A), and the pressure is reduced by the cold-heat utilizing pressure reducing means (EV-1). This refrigerant is combined with the refrigerant discharged from the low-pressure side compressor (COMP-2) and supplied to the heat storage heat receiving section (21A). Thereby, a refrigerant circulation operation suitable for the operation state is obtained, and the practicality of the device can be improved.

According to the fourth aspect of the present invention, during the heat dissipation operation in which heat is radiated by the use side heat exchange means (6), the use side heat exchange means is used.
The decompression unit that decompresses the refrigerant condensed in (6) and guides the refrigerant to the heat-source-side heat exchange means (3) is also used as the decompression means (EV-1) when utilizing cold heat. This makes it possible to obtain the above-described effect according to the first aspect of the present invention while reducing the number of components, thereby improving the practicality of the apparatus.

[Brief description of the drawings]

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

FIG. 2 is a diagram for describing a refrigerant circulation operation in each of a cold storage operation, a cold storage utilization cooling operation, and a normal cooling operation.

FIG. 3 is a diagram for explaining a refrigerant circulation operation in each of a warm storage operation, a heating operation using warm storage, and a normal heating operation.

FIG. 4 is a Mollier diagram showing a refrigerant circulation state during a cooling operation using cold storage.

[Description of Signs] (A) Refrigerant circuit (B) Water circuit (heat storage medium circuit) (1) Compression mechanism (compressor) (COMP-1) First compressor (high-pressure side compressor) (COMP-2 ) 2nd compressor (low pressure side compressor) (3) Outdoor heat exchanger (heat source side heat exchanger) (6) Indoor heat exchanger (use side heat exchanger) (8) Supply pipe (9) Bypass pipe ( 11A) 1st branch pipe (11B) 2nd branch pipe (21A) Refrigerant passage (21B) Water passage (EV-1) 1st outdoor electric expansion valve (decompression means when using cold heat) (EV-3) Indoor electric expansion valve (Utilization side decompression means) (T) Heat storage tank

Claims (4)

[Claims] 1. A heat storage medium circulating circuit (B) in which a heat storage tank (T) and a heat storage supply section (21B) are connected so that a heat storage medium can be circulated.
The compressor (1), the heat source side heat exchange means (3), the heat storage supply section (2
1B), a heat storage heat receiving section (21A) capable of exchanging heat, a use side pressure reducing means (EV-3), and a use side heat exchanger (6) are connected to the refrigerant circulation circuit (A The refrigerant circulation circuit (A) is used during cold-heat utilization operation where heat is absorbed by the use-side heat exchange means (6) using the cold stored in the heat storage tank (T).
Heat storage supply unit at the heat storage heat receiving unit (21A)
(21B), the compressor (1) comprises a high-pressure side compressor (COMP-1), wherein the compressor (1) is cooled by the heat storage medium of (21B) and the refrigerant is supplied to the use side heat exchange means (6). ) And a low-pressure side compressor (COMP-2), and supplies the refrigerant discharged from the high-pressure side compressor (COMP-1) to the heat source side heat exchange means (3) during the above-described cold-heat utilization operation. While condensing, the refrigerant discharged from the low-pressure compressor (COMP-2) is bypassed.
(8, 9) bypasses the heat-source-side heat exchange means (3), flows these refrigerants, supplies them to the heat storage heat receiving section (21A), and decompresses them by the use-side decompression means (EV-3). User side heat exchange means
(6) An ice heat storage device, characterized in that the heat storage device is supplied. 2. The ice heat storage device according to claim 1, wherein a pressure reducing means for utilizing cold energy is provided downstream of the heat source side heat exchange means (3).
(EV-1) is provided, and the heat source side heat exchange means
The refrigerant condensed in (3) is reduced in pressure to the refrigerant pressure in the bypass pipes (8, 9) by the decompression means (EV-1) at the time of utilizing cold heat, and then combined with the refrigerant in the bypass pipes (8, 9). An ice heat storage device, characterized in that: 3. The ice heat storage device according to claim 2, wherein the downstream side of the heat source side heat exchange means (3) is branched into branch pipes (11A, 11B), and the decompression means (EV-1) for utilizing cold energy. Is provided in one branch pipe (11A), and uses the heat exchange means on the user side without using the cold heat of the heat storage tank (T).
In the heat absorbing operation where heat is absorbed in (6), the refrigerant discharged from the compressor (1) is condensed by the heat source side heat exchange means (3), and the other branch pipe
(11B), and the first switching state in which the decompression means (EV-1) is bypassed and supplied to the utilization side decompression means (EV-3) and the utilization side heat exchanger (6) by bypassing the cold heat utilization. During operation, the refrigerant discharged from the high pressure side compressor (COMP-1) is condensed by the heat source side heat exchange means (3) and
A), and the pressure is reduced by the decompression means (EV-1) at the time of utilizing cold energy. This refrigerant is combined with the refrigerant discharged from the low-pressure side compressor (COMP-2) and supplied to the heat storage heat receiving section (21A). An ice heat storage device comprising a switching means (SV-13, EV-1) capable of switching between the switching states. 4. The ice heat storage device according to claim 2, wherein the cold-heat utilizing pressure reducing means (EV-1) supplies the refrigerant discharged from the compressor (1) to the use-side heat exchange means (6). At the time of heat dissipation operation in which heat is dissipated by the use side heat exchange means (6), the use side heat exchange means
An ice heat storage device, which also serves as a decompression unit for decompressing the refrigerant condensed in step (1) and guiding the refrigerant to a heat source side heat exchange means (3).