JP3114618B2 - Ice storage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage medium for cooling a heat storage medium such as water or an aqueous solution to a supercooled state by exchanging heat with a refrigerant, and then eliminating the supercooled state to generate slurry ice. The present invention relates to an ice thermal storage device for storing in a tank,
The present invention relates to an improvement in a refrigerant circulation state for a supercooling heat exchanger that exchanges heat between a heat storage medium and a refrigerant.

[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 an 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 refrigerant heat exchange section of a supercooling heat exchanger are used. A refrigerant circulation circuit sequentially connected by refrigerant pipes, a heat storage tank, a heat storage medium heat exchange section and a supercool elimination section of a supercooling heat exchanger capable of exchanging heat with the refrigerant heat exchange section are sequentially connected by a water pipe. There is known a device provided with a water circulation circuit formed by connection.

[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 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]

The supercooling heat exchanger constructed as described above is generally controlled so that the refrigerant derived from the refrigerant heat exchange section is in an overheated state. In other words, the refrigerant flows through the refrigerant heat exchange section and exchanges heat with water, so that the temperature rises to the evaporation temperature or higher and is derived from the refrigerant heat exchange section. That is,
In this supercooling heat exchanger, a so-called dry operation of the refrigerant is performed.

However, when a dry operation is performed in a heat exchanger for generating such supercooled water, the following problems may be caused.

I) First, when the apparatus has been stopped for a long time or when the thawing operation for eliminating freezing of the subcooling heat exchanger ends, a large amount of liquid refrigerant is stored in the refrigerant heat exchanger section. Could have been. When the ice making operation is started from this state, a part of the liquid refrigerant in the refrigerant heat exchange unit may flow out of the subcooling heat exchanger. In such a situation where the liquid refrigerant flows out, the electric expansion valve is rapidly squeezed so as to perform a predetermined dry operation (an operation state in which the superheated gas refrigerant is discharged from the supercooling heat exchanger). Control is performed such that the refrigerant evaporates reliably in the exchange unit and a degree of superheat is obtained. However, when the expansion valve is throttled in this way, the pressure of the refrigerant in the refrigerant heat exchange unit decreases, and the evaporation temperature of the refrigerant rapidly decreases. Then, since the water in the heat storage medium heat exchange section is cooled by the refrigerant whose temperature has rapidly decreased, a part of the water flowing through the heat storage medium heat exchange section has a large degree of supercooling, and There is a possibility that the cooling state is eliminated and ice is formed, which may block the water flow passage of the heat storage medium heat exchange unit. When such a situation occurs, the flow resistance of the water is significantly increased, the amount of circulating water is reduced, and the ice making efficiency is reduced.

Ii) In the heat exchanger for supercooling water as described above, since the temperature difference between the refrigerant and the water is small, the degree of superheat of the refrigerant may not be accurately detected.
More specifically, for example, when the evaporation temperature of the refrigerant in the refrigerant heat exchange unit is −3.5 ° C. and the temperature of the supercooled water is −1.7 ° C., the temperature inside the heat exchanger is reduced. If the flow direction of the refrigerant and the water is the same direction (parallel flow),
Since the temperature of the refrigerant that exchanges heat with the supercooled water does not rise above the temperature of the water, the degree of superheat of the refrigerant is 1.8 ° C (the temperature between the evaporation temperature of the refrigerant and the supercooled water). The superheat exceeding the temperature difference) will not be applied. In other words, this small temperature difference (a temperature difference that rises only by 1.8 degrees at the maximum with respect to the evaporation temperature) is detected by the sensor, and it is determined whether or not the refrigerant derived from the supercooling heat exchanger is in an overheated state. It is necessary to control the electric expansion valve. Therefore, in order to accurately detect this temperature difference, it is necessary to use an extremely high-precision sensor, and a sensor generally used in this type of device can accurately detect this temperature difference. Instead, when it is determined that the superheat degree has not yet been reached even though the refrigerant derived from the refrigerant flow space has a superheat degree, the opening of the electric expansion valve is reduced, and the evaporation temperature of the refrigerant is reduced. As described above, the supercooled state of the water is eliminated in the water flow passage of the heat storage medium heat exchange unit as described above, so that the ice blocks the passage.

As one type of this type of heat exchanger, there is a vertical liquid-filled shell-and-tube type heat exchanger.
Explaining the configuration of this heat exchanger, it is provided with a cylindrical container having a vertical axis, and a plurality of heat transfer tubes extending in the vertical direction are provided in the container, and each of the heat transfer tubes is connected to a water pipe. Connected to allow water to flow from the lower end toward the upper end, while forming a refrigerant circulation space around the heat transfer tube for allowing the refrigerant to flow in a substantially full state, and a refrigerant introduction pipe at the lower side of the container. Are connected to the refrigerant outlet pipes on the upper side, respectively.
Each pipe is communicated with the refrigerant circulation space. Thereby, in the container, heat exchange is performed between the water flowing inside the heat transfer tube and the refrigerant evaporating in the refrigerant circulation space around the tube, and the water is in a supercooled state.

In particular, when such a shell-and-tube heat exchanger is used as a subcooling heat exchanger and a dry operation is performed, the following problems may be caused in addition to the above-mentioned problems. is there.

Iii) In order to cause the superheated refrigerant to flow out of the refrigerant circulation space, the height of the gas-liquid interface of the refrigerant in the refrigerant circulation space is set low, and the gas region of the refrigerant (between the gas refrigerant and water) is set. It is necessary to secure a large area for heat exchange. The reason is that the temperature difference between the refrigerant and the water inside the subcooling heat exchanger is small. That is, for example, when the evaporation temperature of the refrigerant in the refrigerant circulation space is −3.5 ° C. and the temperature of the supercooled water is −1.7 ° C., the −1.7 ° C. It is necessary to heat the refrigerant at 3.5 ° C. until the degree of superheating is reached. In this way, the heat exchange between the two with a small temperature difference (in this case, the temperature difference is 1.8 deg) ensures that the refrigerant is overheated. In order to obtain it, it is necessary to secure a heat exchange area between the gas refrigerant and water as large as possible. In order to increase the heat exchange area, it is necessary to enlarge the gas area, that is, to set the gas-liquid interface of the refrigerant low.

However, in such a configuration, if the height dimension of the subcooling heat exchanger is restricted, the storage area of the liquid refrigerant for cooling the water to the supercooled state is originally small. That is, the heat exchange area of the region that uses the latent heat change of the refrigerant for generating the supercooled water becomes extremely small. For this reason, since it becomes necessary to cool water to a predetermined supercooled state by heat exchange in this small heat exchange region, the evaporation temperature of the refrigerant is set low to increase the amount of heat exchange per unit area. Need arises. However, if the evaporation temperature of the refrigerant is set to be low in this way, the degree of supercooling of a part of the water in the heat transfer tube becomes too large, the supercooled state is eliminated, and ice is formed, as in the above case. There is a possibility that the ice making efficiency may be reduced.

Iv) As described above, as the height of the gas-liquid interface of the refrigerant in the refrigerant circulation space decreases, the lubrication for compressor lubrication that flows into the refrigerant circulation space and stays near the gas-liquid interface. It becomes difficult for oil to return from the refrigerant outlet pipe to the compressor, and if such a state continues for a long period of time, poor lubrication of the compressor may be caused.

As described above, when the dry operation is performed in the supercooling heat exchanger that generates the supercooling water for ice making, various problems may be caused.

The present invention has been made in view of the above circumstances, and an object of the present invention is to avoid the above-mentioned various disadvantages by improving the circulation state of the refrigerant in this type of heat exchanger. is there.

[0016]

According to a first aspect of the present invention, there is provided an apparatus for controlling a dry operation by controlling a refrigerant derived from a subcooling heat exchanger to be wet steam. Bug fixes.

Specifically, a plurality of heat transfer tubes (4
9) in a container (48).
The outside of each heat transfer tube (49) is formed as a refrigerant heat exchange section (42a).
The interior of each heat transfer tube (49) constitutes a heat storage medium heat exchange section (42b).
Been supercooling heat exchanger (42), the compressor (1) and the heat source-side heat exchanger (3) and the expansion mechanism refrigerant heat exchange section of (52a) and the subcooling heat exchanger (42) (42a) DOO is a refrigerant circuit (a) comprising connected to be capable of circulating refrigerant through refrigerant piping (8), over the heat storage tank (T) and circulating means for pumping the heat storage medium (P) and for storing the heat storage medium Heat storage medium heat exchange part of cooling heat exchanger (42)
(42b) is connected by a circulation pipe (45) so that the heat storage medium can be circulated , the refrigerant flowing through the refrigerant heat exchange section (42a), and the heat storage medium heat exchange section (42b ), The heat storage medium in the liquid phase flowing therethrough is subjected to heat exchange, the heat storage medium is cooled to a supercooled state by the evaporating refrigerant, and after the heat storage medium is led out of the supercooled heat exchanger (42), the supercooled state is changed. Ice-making operation means (71) for performing ice-making operation for dissolving and generating ice and collecting the ice in the heat storage tank (T);
A wetness control means (72) for maintaining the refrigerant temperature at the evaporation temperature so that the refrigerant on the outlet side of the refrigerant heat exchange section (42a) becomes wet vapor is provided.

With this configuration, the operation during ice making is as follows.
The heat storage medium taken out of the heat storage tank (T) exchanges heat with the refrigerant flowing through the refrigerant heat exchange section (42a) in the heat storage medium heat exchange section (42b), and is cooled to a supercooled state. After being drawn out from the heat exchange section (42b), 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. During such an ice making operation, the supercooling heat exchanger (42) includes a wetness control unit.
By (72), the refrigerant temperature is maintained at the evaporation temperature so that the refrigerant on the outlet side of the refrigerant heat exchange section (42a) becomes wet vapor. For this reason, a decrease in the refrigerant evaporation temperature, which has been a problem in the dry operation, can be suppressed, and freezing of the subcooling heat exchanger (42) is avoided.

According to a second aspect of the present invention, in the ice heat storage device of the first aspect, the expansion mechanism is an expansion valve (52a) whose opening degree can be adjusted, and the wetness control means (72) includes the expansion valve (52a). The opening is adjusted.

With this configuration, when the opening degree of the expansion valve (52a) is increased, the evaporation temperature rises as the refrigerant pressure in the refrigerant heat exchange section (42a) increases, and conversely, the opening degree of the expansion valve (52a) increases. When the pressure is reduced, the evaporation temperature decreases with a decrease in the refrigerant pressure in the refrigerant heat exchange section (42a). That is, in a situation where the outlet refrigerant of the refrigerant heat exchange section (42a) evaporates and overheats, control is performed to increase the degree of opening of the expansion valve (52a) so that the outlet refrigerant becomes wet steam. Done.

According to a third aspect of the present invention, in the ice heat storage device of the second aspect, the superheat degree detecting means (Th-SH1) for detecting the degree of superheat of the refrigerant derived from the subcooling heat exchanger (42) is provided. The wetness control means (72) is provided with the superheat degree detection means (Th-
Upon receiving the output of SH1), the target value of the superheat degree of the derived refrigerant is set to 0 deg, and the opening of the expansion valve (52a) is adjusted.

With this configuration, it is possible to obtain a specific configuration for maintaining the refrigerant temperature at the evaporation temperature so that the refrigerant on the outlet side of the refrigerant heat exchange section (42a) becomes wet steam during the ice making operation.

According to a fourth aspect of the present invention, in the ice heat storage device of the second aspect, a heating means (65) for applying a predetermined amount of heat to the refrigerant derived from the subcooling heat exchanger (42) to heat the refrigerant. Superheat degree detection means (Th-SH2) for detecting the degree of superheat of the refrigerant superheated by heating, receiving the output of the superheat degree detection means (Th-SH2), the superheat degree and the heating means (65) to the refrigerant Determining means (73) for determining whether or not the refrigerant derived from the subcooling heat exchanger (42) is in a wet state based on the applied heat amount, and the wetness controlling means (72) includes the determining means Upon receiving the output of (73), the opening of the expansion valve (52a) is adjusted so that the refrigerant derived from the supercooling heat exchanger (42) is in a predetermined wet state.

With this configuration, the operation of turning the refrigerant on the outlet side of the refrigerant heat exchange section (42a) into wet vapor is to give a predetermined amount of heat to the refrigerant derived from the subcooling heat exchanger (42) by the heating means (65). . Then, the degree of superheat of the refrigerant superheated by this heating is detected by the superheat degree detection means (Th-SH2), and based on the degree of superheat and the amount of heat given to the refrigerant by the heating means (65), the supercooling heat exchanger ( The determination unit (73) determines whether the refrigerant derived from the (42) is in a wet state, and based on this, the wetness control unit (72) determines whether the refrigerant derived from the subcooling heat exchanger (42) is The opening of the expansion valve (52a) is adjusted so as to obtain a predetermined wet state.

According to a fifth aspect of the present invention, in the ice heat storage device of the fourth aspect, the heating means (65) includes an expansion valve (52a).
The high-temperature refrigerant flowing through the upstream refrigerant pipe (8) exchanges heat with the refrigerant derived from the supercooling heat exchanger (42).

According to this configuration, the configuration of the heating means (65) for giving a predetermined amount of heat to the refrigerant derived from the subcooling heat exchanger (42) can be specifically obtained, and the superheating means (65) can be cooled without requiring a special heating source. The refrigerant derived from the cooling heat exchanger (42) can be brought into an overheated state.

According to a sixth aspect of the present invention, in the ice heat storage device of the first aspect, the wetness control means (72) is provided with an expansion mechanism.
The degree of pressure reduction of the refrigerant by (52a) is made constant.

In this configuration, particularly in the device according to the present invention, the amount of circulation of the heat storage medium circulating in the heat storage circuit (B) and the required degree of supercooling hardly change.
As for (52a), no problem occurs even if the degree of pressure reduction is constant. In other words, when the expansion mechanism (52a) is an expansion valve whose opening can be adjusted, the opening control can be kept constant, and the control operation can be simplified, and a capillary tube can be used as the expansion mechanism (52a). It is also possible to apply.

[0029]

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 an embodiment of the present invention. FIG. 2 is a diagram showing a water circulation circuit (B) as a heat storage circulation circuit. As shown in FIG. 1, the present air conditioner includes an outdoor unit (X) and a plurality of indoor units (Y, Y,
Y) are connected by liquid-side and gas-side connecting pipes (RL, RG) which constitute a part of the refrigerant circuit (A). Hereinafter, the refrigerant circuit (A)
And the water circulation circuit (B).

-Description of Refrigerant Circuit-First, the main circuit configuration of the refrigerant circuit (A) will be described.

This refrigerant circuit (A) is an outdoor unit
(X), an outdoor heat exchanger (3) as a heat source side heat exchanger in which a four-way switching valve (2), an outdoor fan (F) is disposed in close proximity, and a receiver (4) And first outdoor electric expansion valve
(5), a plurality of indoor electric expansion valves (6, 6, 6) provided in the indoor unit (Y), and an indoor heat exchanger (7, 7, 7) as a use-side heat exchanger are connected with refrigerant pipes. (8) A main refrigerant circuit (A-1) sequentially connected by (8).

A detailed description will be given of the connection state of each device by the refrigerant pipe (8). A gas side pipe (10) is provided at one end on the gas side of the outdoor heat exchanger (3), and a gas side pipe (10) is provided at the other end on the liquid side. Are connected to liquid side pipes (11), respectively. Gas side piping
(10) is connected to the discharge side and the suction side of the compression mechanism (1) by a four-way switching valve (2) so as to be switchable. That is, the gas side pipe (10) is connected between the discharge side of the compression mechanism (1) and the four-way switching valve.
(2), a second discharge gas line (10b) connecting the four-way switching valve (2) and the outdoor heat exchanger (3), a four-way switching valve (2). ) And a suction gas line (10c) connecting the suction side of the compression mechanism (1). Also,
The intake gas line (10c) is provided with an accumulator (12).

On the other hand, the liquid side pipe (11) is connected to the outdoor heat exchanger (3).
A first liquid line (11a) connecting the receiver and the receiver (4), a second liquid line (11b) connecting the receiver (4) and the first outdoor electric expansion valve (5), and an outdoor electric expansion valve (5) And a third liquid line (11c) for connecting the liquid side communication pipe (RL) with the third liquid line (11c). The first liquid line (11a) has a receiver from the outdoor heat exchanger (3).
Check valve (CV1) that allows only refrigerant flow to (4)
However, in the third liquid line (11c), two check valves (CV2, CV3) each permitting only the flow of the refrigerant from the outdoor electric expansion valve (5) to the liquid side communication pipe (RL) are provided. Have been.

A check valve in the first liquid line (11a)
The fourth liquid line (11d) is connected between (CV1) and the receiver (4) and the downstream side of the check valve (CV3) in the third liquid line (11c). The fourth liquid line (11d) is provided with a check valve (CV4) that allows only the flow of the refrigerant from the third liquid line (11c) to the first liquid line (11a).

The liquid side communication pipe (RL) is connected to the liquid side of each indoor heat exchanger (7, 7, 7) via a plurality of indoor liquid pipes (7a, 7a, 7a). . Each of the indoor liquid pipes (7a, 7a, 7a) is provided with the indoor electric expansion valve (6, 6, 6).

On the other hand, the gas side communication pipe (RG) is connected to each indoor heat exchanger (7, 7, 7) through a plurality of indoor gas pipes (7b, 7b, 7b).
Is connected to the gas side. In addition, this gas side communication pipe (R
G) is connected to a four-way switching valve (2) via a gas pipe (15), and the connection state between the discharge side and the suction side of the compression mechanism (1) is switched by the four-way switching valve (2). It is possible.

The compression mechanism (1) is a variable displacement type upstream compressor whose capacity is controlled in a number of stages by inverter control.
(COMP-1) and a downstream compressor with an unloader mechanism that is controlled to switch between full load, unload and stop.
(COMP-2) in parallel with each other.

The refrigerant circuit (A) is provided with an oil return mechanism (20) for returning lubricating oil to the compression mechanism (1). The oil return mechanism (20) includes an oil separator (21, 22) and an oil return pipe (23, 24). The oil separators (21, 22) are
The upstream compressor (C) which is a part of the first discharge gas line (10a)
OMP-1) and each discharge pipe (10a-1, 10a) of the downstream compressor (COMP-2).
-2). In addition, the oil return pipe (23,
24) has a capillary tube (CP) and an oil separator (21,
22) and the suction pipe (10c-1) of the upstream compressor (COMP-1), which is a part of the suction gas line (10c),
The lubricating oil collected in the oil separators (21, 22) is transferred to the upstream compressor (COMP-
It is configured to return to 1). In addition, each discharge pipe (10a-
In the downstream side of the oil separators (21, 22) in (1, 10a-2), a reverse flow that allows only the flow of refrigerant from each compressor (COMP-1, COMP-2) to the four-way switching valve (2) is allowed. Stop valves (CV5, CV6) are provided respectively.

The suction pipe (10c-2) of the downstream compressor (COMP-2), which is a part of the suction gas line (10c), is connected to the suction pipe (10c) of the upstream compressor (COMP-1). -1) The pressure loss is set to be greater than that of the compressor (COMP-1, COMP-2), and an oil equalization pipe (25) equipped with a capillary tube (CP) is connected between both compressors (COMP-1, COMP-2).
As a result, the lubricating oil collected by the upstream compressor (COMP-1) on the high pressure side is supplied to the downstream compressor (COMP-2) on the low pressure side, and each of the compressors (COMP-1, COMP-2), lubricating oil is evenly collected.

An auxiliary heat exchanger (30) is provided adjacent to the outdoor heat exchanger (3).
The gas side of (0) is connected to the downstream side of the check valves (CV5, CV6) in the first discharge gas line (10a) by the auxiliary gas line (31). On the other hand, the liquid side of the auxiliary heat exchanger (30) is connected to the downstream side of the check valve (CV1) in the first liquid line (11a) by the auxiliary liquid line (32). The auxiliary liquid line (32) has a capillary tube (CP) and a first solenoid valve.
(SV1) is provided.

Further, a check valve in the third liquid line (11c)
Check valve (C) in the upstream side of (CV2) and the first liquid line (11a).
The heating liquid line (33) is connected to the upstream side of V1). This heating liquid line (33) has a third liquid line (11c)
A check valve (CV7) is provided to allow only the flow of the refrigerant from the outside to the outdoor heat exchanger (3).

Further, the second liquid line (11b) and the downstream side of the check valve (CV2) in the third liquid line (11c) are connected by a bypass line (34). This bypass line (3
4) is provided with a second solenoid valve (SV2) and a check valve (CV8) that allows only the flow of refrigerant from the second liquid line (11b) to the third liquid line (11c). The main circuit configuration of the refrigerant circuit (A) has been described above.

-Description of Water Circulation Circuit- Next, the configuration of the water circulation circuit (B) will be described.

As shown in FIG. 2, the water circulation circuit (B) comprises a heat storage tank (T), a pump (P) as a circulating means, a preheater (40) comprising a heat exchanger having a double pipe structure, (41), a heat storage heat exchanger (42) as a subcooling heat exchanger composed of a vertical shell and tube heat exchanger, and a subcooling eliminator (4
3) are sequentially connected by a water pipe (45) so that water circulation (see the arrow in FIG. 2) is possible. The water pipe (45a) connecting the heat storage heat exchanger (42) and the supercooling canceller (43) is provided with an ice nucleus generator (46) and an ice growth preventer (47). The preheater (40) and the heat storage heat exchanger (42) exchange heat between the refrigerant flowing in the refrigerant circuit (A) and water.

The preheater (40) and the heat storage heat exchanger (4)
The configuration of the refrigerant circuit (A) for supplying a refrigerant that exchanges heat with water in 2) will be described.

As shown in FIG. 1, the preheater (40) is provided in the middle of the third liquid line (11c). When the refrigerant in the third liquid line (11c) flows through the outer space, heat is exchanged between the two (see FIG. 2). Also, the third
The thawing bypass line (50) connects the liquid line (11c) between the preheater (40) and the connection position of the bypass gas line (34) and the upstream side of the accumulator (12).
The defrost bypass line (50) is provided with a third solenoid valve (SV3).

Next, the configuration of the heat storage heat exchanger (42) will be described. As shown in FIG. 3, the heat storage heat exchanger (42) is a closed cylindrical container (4) having an axis extending vertically.
8). At the upper and lower ends in the container (48), the water circulation spaces (48a), (48a), on the outlet side and the inlet side as the outlet and inlet spaces for the heat storage medium defined by the tube sheets (36), (37) 48
b) and the outlet water distribution space (48a)
A plurality of heat transfer tubes (49, 49,...) Are provided to extend and connect between the inlet side water circulation space (48b) in the vertical direction.
In detail, the outlet side tube sheet (36) located on the upper side
8) is disposed over the entire inner surface of the container (48) at a lower position at a predetermined distance from the upper surface of the container, and the outlet side water circulation space (48a), which is the upper space, and the lower space And a refrigerant circulation space (48c). On the other hand, the introduction-side tube sheet (37) located on the lower side is arranged over the entire inner surface of the container (48) at an upper position at a predetermined distance from the lower surface of the container (48), and A lower water flow space (48b), which is a lower space, and the refrigerant flow space (48c) are defined. A mixer is installed in the inlet water flow space (48b).
The water pipe (45c) extending from (41) is connected to the outlet water flow space (48
In (a), water pipes (45d) connected to the supercooler (43) are connected respectively. Each of the heat transfer tubes (49, 49,...) Is a straight tube provided with a radiation fin (not shown) on the outer peripheral surface, and is arranged in parallel at positions equidistant from each other. (36) and opens to the outlet side water circulation space (48a), and the lower end penetrates the inlet side tube sheet (37) to open to the inlet side water circulation space (48b). In other words, each heat transfer tube (49,49,
…) Is the water flow space from the inlet side (48b) to the water flow space on the outlet side
Water distribution to (48a) is possible.

A lower connecting pipe (52) is connected to the lower part of the refrigerant flow space (48c), and an upper connecting pipe (51) is connected to the upper part. This upper connecting pipe (51) and lower connecting pipe
(52) is a heat storage heat exchanger (42) in the case of a cold storage operation, a defrosting operation, a simultaneous cold storage / cooling operation, and a heating operation utilizing hot storage, which will be described later.
It functions as a refrigerant introduction pipe for introducing the refrigerant into the refrigerant circulation space (48c) and a refrigerant discharge pipe for extracting the refrigerant from the refrigerant circulation space (48c). With such a configuration, the heat storage medium heat exchange section (42b) is constituted by each water circulation space (48a, 48b) and the internal passage of the heat transfer tube (49), and the refrigerant heat exchange section (42c) is formed by the refrigerant circulation space (48c). 42a) is configured.

Then, in the refrigerant circulation space (48c),
By introducing or taking out the refrigerant from the upper connection pipe (51) and the lower connection pipe (52), the refrigerant has a gas-liquid interface (G) and circulates in a substantially full state in the refrigerant flow space (48c). Has become. That is, the heat storage heat exchanger (42) is
Inside, the refrigerant introduced and led by the upper connection pipe (51) and the lower connection pipe (52) flows around each heat transfer pipe (49), and this refrigerant and water flowing through each heat transfer pipe (49) Is configured to perform heat exchange. The gas-liquid interface (G) is a container
It is located below the connection position of the upper connection pipe (51) to (48). The height of the gas-liquid interface (G) is adjusted, for example, by adjusting the opening of a second outdoor electric expansion valve (52a) provided in the lower connection pipe (52). The above is the main configuration of the heat storage heat exchanger (42).

On the other hand, as shown in FIG. 1, one end of the upper connection pipe (51) is connected to the suction gas line (10c) upstream of the connection position of the defrost bypass line (50). on the other hand,
One end of the lower connection pipe (52) is connected between the preheater (40) and the check valve (CV3) in the third liquid line (11c). The upper connection pipe (51) is provided with a fourth solenoid valve (SV4), and the lower connection pipe (52) is provided with the second outdoor electric expansion valve (52a). The lower connecting pipe (52) is
When the outdoor electric expansion valve (52a) is fully open, the inner diameter is set so that the refrigerant flowing through the refrigerant heat exchange section (42a) does not overheat.

The heat storage bypass pipe (53) is provided between the upper end of the receiver (4) and the second outdoor electric expansion valve (52a) and the heat storage heat exchanger (42) in the lower connection pipe (52). Connected by The heat storage bypass pipe (53) is provided with a capillary tube (CP) and a fifth solenoid valve (SV5).

Further, between the connection position of the auxiliary gas line (31) in the first discharge gas line (10a) and the check valves (CV5, CV6), and the heat storage bypass pipe (53) in the lower connection pipe (52). )
And the second outdoor electric expansion valve (52a) are connected by a hot gas supply pipe (54). The hot gas supply pipe (54) is provided with a sixth solenoid valve (SV6).

Further, the downstream side of the sixth solenoid valve (SV6) in the hot gas supply pipe (54) and the upper side of the heat storage heat exchanger (42) are connected by a heat storage utilization supply pipe (55). I have.
The heat storage utilization supply pipe (55) is provided with a seventh solenoid valve (SV7).

By connecting the refrigerant pipes to the preheater (40) and the heat storage heat exchanger (42) in this manner, when the refrigerant is supplied from each refrigerant pipe to each device (40, 42), Heat exchange is performed between the refrigerant and the water to cool or heat the water. Specifically, for example, the water is cooled so as to generate supercooled water for ice making in the heat storage heat exchanger (42), or the ice is melted when the ice circulates through the water pipe (45). The water is heated by the preheater (40).

Next, the ice nucleus generator (46) and the ice progress preventing device (47) will be described. The ice nucleator (46) is connected to the water pipe (4
5a) A part of the water flowing through the refrigerant circulation circuit (A) is cooled and iced by the refrigerant flowing through the refrigerant circulation circuit (A), and this is used as ice nuclei to remove the supercool
Is to be supplied to The ice nucleus generator (46) has an ice nucleation refrigerant introduction pipe (58) and an ice nucleation refrigerant extraction pipe (59).
Is connected. One end of the ice nucleation refrigerant introduction pipe (58) is located between the connection position of the hot gas supply pipe (54) in the lower connection pipe (52) and the second outdoor electric expansion valve (52a), and the other end is an ice nucleus. Each is connected to a generator (46). Further, the ice nucleation refrigerant introduction pipe (58) includes a capillary tube (CP).
One end of the ice nucleation refrigerant outlet pipe (59) has one end of the downstream compressor (C
The other end is connected to the suction pipe (10c-2) of the OMP-2) and the ice nucleus generator (46). As a result, the ice nucleation refrigerant introduction pipe (5
Refrigerant and water pipe (45a) introduced from 8) to ice nucleus generator (46)
Supercooled water flowing through the water pipe (45a) by cooling the water by performing heat exchange with the water flowing through the water pipe (45a) and forming a part of this water as ice blocks on the inner wall surface of the water pipe (45a). A part of the ice is brought into contact with the ice block to eliminate the supercooling to generate an ice nucleus, and the ice nucleus is caused to flow toward the supercooling canceller (43) .

The ice progress preventing device (47) is disposed upstream of the ice nucleator (46) in the flow direction of water, and is connected to the water pipe (45a) from the ice nucleator (46). Of ice along the pipe wall. And this ice progress prevention device (47)
The anti-progression refrigerant inlet pipe (60) and the anti-progression refrigerant outlet pipe (6
1) is connected. One end of the propagation preventing refrigerant introduction pipe (60) is connected to the auxiliary gas line (31), and the other end is connected to the ice growth preventing device (47). The expansion prevention refrigerant outlet pipe (61) has one end of the capillary tube (CP) in the auxiliary liquid line (32).
The other end is connected between the first solenoid valve (SV1) and the other end of the ice prevention device (47).
Connected to each other. Also, this progress prevention refrigerant outlet pipe
(61) has a capillary tube (CP). As a result, the ice nucleus generator (4) is heated by heating the wall of the water pipe (45a) with the refrigerant introduced from the propagation prevention refrigerant introduction pipe (60).
6) to stop ice from developing.

Further, the mixer (41) and the supercooler (4)
3) is composed of a hollow cylindrical container, and water is introduced from the tangential direction of the inner peripheral surface by a water pipe (45), and the water introduced into the container is swirled. This allows the mixer
In (41), as described later, the ice discharged from the heat storage tank (T) and the water heated by the preheater (40) are mixed and stirred to promote the melting of the ice, while the supercooling is performed. Elimination device (43)
In the above, the ice nuclei generated by the ice nucleus generator (46) and the supercooled water generated by the heat storage heat exchanger (42) are mixed and stirred to promote the elimination of the supercooling.

A filter (62) in FIG. 2 is a filter for removing ice and impurities contained in the water introduced into the preheater (40).

The open / close state of the four-way switching valve (2), the solenoid valves (SV1 to SV7) and the electric expansion valves (5, 6, 52a) is controlled by the controller (70). ing.

-Configuration of Sensors- Various sensors are provided in the refrigerant circuit (A) and the water circuit (B). First, in the refrigerant circuit (A), an outdoor air temperature sensor (Th-1) for detecting the outdoor air temperature is provided near the outdoor heat exchanger (3). An outdoor liquid temperature sensor (Th-2) for detecting the liquid refrigerant temperature of the compression mechanism (1) is provided on the branch pipe side, and discharge gas temperature sensors (Th-31, Th-32) for detecting the discharge gas refrigerant temperature of the compression mechanism (1). A suction gas temperature sensor (Th-4) that detects the suction gas refrigerant temperature of the compression mechanism (1) is provided at the discharge pipe (10a-1, 10a-2) of each compressor (COMP-1, COMP-2). The suction gas lines (10c) of (1) are provided respectively. Further, a high pressure sensor (SEN-H) for detecting the refrigerant pressure discharged from the compression mechanism (1) is provided to the first discharge gas line (10a), and a low pressure pressure sensor (SEN-H) for detecting the suction refrigerant pressure of the compression mechanism (1). -L) are provided in the upper connection pipe (51) connected to the suction gas line (10c), respectively, and the high pressure protection is activated when the discharge refrigerant pressure of each compressor (COMP-1, COMP-2) reaches a predetermined high pressure. The switches (HPS, HPS) are connected to each compressor (COM
P-1, COMP-2) in the discharge pipe (10a-1,10a-2).

On the other hand, in the water circulation circuit (B), an inlet water temperature sensor (Th-W1) is provided at the water inlet at the lower end of the preheater (40).
Near the water outlet at the lower end of (41), an outlet water temperature sensor (Th-W
2) The supercooled water temperature sensor (Th-W3) is provided at the water outlet side at the upper end of the heat storage heat exchanger (42), and the ice formation detection sensor (Th-W4) is provided at the supercool eliminator (43). It detects the water temperature at each part. Further, a flow switch (SW) which is turned on when the flow rate of the water in the water inlet pipe (45b) is detected at the water inlet pipe (45b) connected to the lower end of the preheater (40) and becomes lower than a predetermined value is detected. -F) is provided.

As shown in FIG. 3, the upper connecting pipe (5) is connected to the upper connecting pipe (51) connected to the heat storage heat exchanger (42).
A superheat detection sensor (Th-SH1) is provided as superheat detection means for detecting the superheat of the refrigerant flowing in 1). As the actual superheat degree detection operation, the above low pressure pressure sensor (SEN-
The saturation temperature corresponding to the refrigerant pressure is calculated based on the suction refrigerant pressure detected in L), and the superheat is obtained by subtracting this temperature from the temperature detected by the superheat detection sensor (Th-SH1).

-Configuration of Control-The air conditioner of the present invention is configured such that each sensor (Th-1 to SEN-L, Th-
W1 to Th-W4), switch (HPS), and switch (SW-F) detection signals are input to the controller (70), and based on these detection signals, each solenoid valve (SV1 to SV7) is opened and closed. Electric expansion valve
(5, 6, 52a) and the capacity of the compression mechanism (1) are controlled.

The controller (70) is provided with an ice making operation means (71) for causing the air conditioner to perform a cold heat storage operation as an ice making operation, and a wetness control means (72).

The ice making operation means (71) makes the water in the water circulating circuit (B) in a supercooled state as in the cold heat storage operation described later, eliminates this supercooled state, generates ice, and stores the ice in the heat storage tank. (T)
In this case, a driving operation such as recovery is performed.

The wetness control means (72) includes the ice making operation means (7
During the cold storage operation according to 1), the refrigerant temperature is maintained at the evaporation temperature so that the refrigerant on the outlet side of the refrigerant heat exchange section (42a) becomes wet vapor. Specifically, the superheat detection sensor (T
h-SH1) so that the degree of superheat of the refrigerant flowing through the upper connection pipe (51) detected by the second outdoor electric expansion valve (52
The opening of a) is controlled.

-Operation- Next, the operation of the air conditioner configured as described above will be described.

The operation modes of the air conditioner include a normal cooling operation, a normal heating operation, an ice nucleation operation, a cold storage operation, a thawing operation, a simultaneous cold storage / cooling operation, a cooling operation using a cold storage operation, a hot storage operation, There are simultaneous operation of warm storage / heating and heating operation using warm storage. Hereinafter, the refrigerant circulation operation in each operation mode will be described.

-Normal cooling operation- In this operation mode, the controller (70) switches the four-way switching valve (2) to the solid line side in the figure, and the indoor electric expansion valve
(6) is adjusted to a predetermined opening (superheat control), and the other electric expansion valves are closed. On the other hand, the second solenoid valve (SV2) is opened, and the other solenoid valves are closed.

When the compression mechanism (1) is driven in this state, the refrigerant discharged from the compression mechanism (1) passes through the four-way switching valve (2) as shown by the arrow in FIG. The heat is exchanged with the outside air in the outdoor heat exchanger (3) and condensed. Thereafter, the refrigerant is introduced into the indoor unit (Y, Y, Y) via the liquid side pipe (11) and the bypass line (34), and is depressurized by the indoor electric expansion valve (6, 6, 6). The heat exchanger (7, 7, 7) exchanges heat with room air to evaporate and cool the room air. This gas refrigerant is supplied to the gas pipe (15), the four-way switching valve (2), and the suction gas line (10
Through c), it is returned to the suction side of the compression mechanism (1). By performing such a circulation operation of the refrigerant, indoor cooling is performed.

-Normal heating operation- In this operation mode, the four-way switching valve (2) is switched to the broken line side by the controller (70), and the first outdoor electric expansion valve is operated.
While (5) is adjusted to a predetermined opening, the indoor electric expansion valve (6)
Is fully opened. Also, the second outdoor electric expansion valve (52a)
And each solenoid valve is closed together.

When the compression mechanism (1) is driven in this state, the refrigerant discharged from the compression mechanism (1) passes through the four-way switching valve (2) and the gas pipe (15) as shown by arrows in FIG. After being introduced into the indoor unit (Y, Y, Y), the indoor heat exchanger (7, 7, 7) exchanges heat with the indoor air to condense and heat the indoor air. Thereafter, the refrigerant reaches the receiver (4) via the third liquid line (11c) and the fourth liquid line (11d), flows from the receiver (4) through the second liquid line (11b), and flows into the first outdoor electric line. After the pressure is reduced by the expansion valve (5), the heat is introduced into the outdoor heat exchanger (3) from the heating liquid line (33), and the outdoor heat exchanger (3) exchanges heat with the outside air to evaporate. . After that, the compression mechanism (1) passes through the four-way switching valve (2) and the suction gas line (10c).
Is returned to the suction side. The indoor heating is performed by performing such a circulation operation of the refrigerant.

-Ice nucleus generation operation-This operation mode is for generating ice nuclei for eliminating the supercooled state of the supercooled water in the cold heat storage operation described later. In this operation mode, a water cooling operation for cooling water in the water circulation circuit (B) to a predetermined temperature (for example, 2 ° C.) is performed before the start of the ice nucleation operation. Explaining the circulation operation of water and refrigerant in the water cooling operation, the second outdoor electric expansion valve (52a) is adjusted to a predetermined opening, and the first and second electromagnetic valves (SV1, SV2) are opened. Other electric expansion valves and solenoid valves are closed. Further, the four-way switching valve (2) is switched to the solid line side. In this state, the pump (P) is driven to circulate water in the water circulation circuit (B), and the compression mechanism (1) is driven. The refrigerant discharged from the compression mechanism (1)
After condensing in the outdoor heat exchanger (3), the pressure is reduced in the second outdoor electric expansion valve (52a) through the liquid side pipe (11) and the lower connecting pipe (52), and then the refrigerant in the heat storage heat exchanger (42) The heat is introduced into the circulation space (48c), where heat exchange is performed with water flowing through each heat transfer tube (49), and the water is cooled and evaporated. Thereafter, the refrigerant in the refrigerant flow space (48c) is returned to the suction side of the compression mechanism (1) by the upper connection pipe (51) and the suction gas line (10c). At this time, the upper connection pipe (51) is in the refrigerant circulation space (48c).
It functions as a refrigerant outlet pipe that leads the refrigerant inside.

When such a water cooling operation is performed for a predetermined time and the water temperature of the water circulation circuit (B) reaches a predetermined temperature,
Move to the following ice nucleation operation.

In this ice nucleation operation, the controller (70)
Accordingly, the four-way switching valve (2) is set to the solid line side, the second outdoor electric expansion valve (52a) is adjusted to a predetermined opening degree, and the other electric expansion valves are closed. In addition, the first and second solenoid valves (SV1, SV1
2) is opened while other solenoid valves are closed.

In this state, in the water circulation circuit (B),
The pump (P) is driven to circulate the water cooled by the water cooling operation in the water circulation circuit (B). on the other hand,
In the refrigerant circuit (A), only the upstream compressor (COMP-1) of the compression mechanism (1) is driven. And this compressor (COM
The refrigerant discharged from P-1) is, as indicated by the arrow in FIG.
Part of the heat is introduced into the outdoor heat exchanger (3) through the four-way switching valve (2), and heat exchanges with the outside air in the outdoor heat exchanger (3) to condense. After that, this refrigerant is
(11), the bypass line (34), the lower connection pipe (52), the second outdoor electric expansion valve (52a), and the ice nucleus generating refrigerant (46). Another part of the refrigerant discharged from the compressor (COMP-1) is introduced into the auxiliary heat exchanger (30) through the auxiliary gas line (31), and the auxiliary outdoor heat exchanger (30)
Also in the above, heat exchange is performed with the outside air to condense. Thereafter, the refrigerant joins the liquid side pipe (11). The refrigerant condensed in the outdoor heat exchanger (3) and the auxiliary outdoor heat exchanger (30) is decompressed by the second outdoor electric expansion valve (52a).
After cooling the water flowing through the water pipe (45a) inside the ice nucleus generator (46) to generate ice nuclei, the ice nucleation refrigerant outlet pipe (5)
9) and is returned to the suction side of the upstream compressor (COMP-1) via the suction pipe (10c-1).

On the other hand, a part of the refrigerant flowing through the auxiliary gas line (31) is supplied from the expansion preventing refrigerant introduction pipe (60) to the ice expansion preventing device.
Heat is supplied to the pipe (47) to heat the pipe wall of the water pipe (45a), thereby preventing ice from developing along the pipe wall from the ice nucleus generator (46). Then, the refrigerant is joined to the auxiliary liquid line (32) from the expansion prevention refrigerant outlet pipe (61). For this reason,
Even in a situation where ice grows along the wall surface upstream (toward the heat storage heat exchanger (42)), so-called ice progresses, this growing ice reaches the growth preventer (47). This progress is made possible by the heat storage heat exchanger
It does not reach (42). After such an ice nucleation operation is continuously performed for a predetermined time (for example, 5 minutes), the process proceeds to a cold heat storage operation described later.

-Cold heat storage operation- In this operation mode, supercooled water is brought into contact with ice nuclei generated by the above-described ice nucleus generation operation,
The supercooled state is eliminated around the ice nuclei to generate ice for heat storage.

In this operation mode, the four-way switching valve (2) is set to the solid line side by the controller (70), the second outdoor electric expansion valve (52a) is adjusted to a predetermined opening degree, and the other electric expansion is adjusted. The valve is closed. Also, the first, second, and fourth solenoid valves (SV1, S
V2, SV4) are opened, while the other solenoid valves are closed.

In this state, 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) is turned into a four-way switching valve as shown by an arrow in FIG.
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 supplied to the liquid side pipe (11) and the bypass line.
(34), it is introduced into the heat storage heat exchanger (42) through the lower connecting pipe (52). Further, another part of the refrigerant discharged from the compression mechanism (1) is introduced into the auxiliary heat exchanger (30) through the auxiliary gas line (31), and is connected to the outside air in the auxiliary outdoor heat exchanger (30). It exchanges heat between it and condenses. Thereafter, the refrigerant joins the liquid side pipe (11) via the auxiliary liquid line (32). Each heat exchanger (3,3
The refrigerant condensed in step (0) is reduced in pressure by the second outdoor electric expansion valve (52a). Then, the refrigerant introduced into the refrigerant flow space (48c) of the heat storage heat exchanger (42) passes through each heat transfer tube (49) in the refrigerant flow space (48c) of the heat storage heat exchanger (42). The water exchanges heat with the flowing water to evaporate, and the water is cooled to a supercooled state (for example, −2 ° C.). Then the upper connecting pipe
(51) and is returned to the suction side of the compression mechanism (1) through the suction gas line (10c). Also at this time, the upper connection pipe (51) functions as a refrigerant outlet pipe for extracting the refrigerant from the inside of the refrigerant flow space (48c).

In the present operation, the above-described ice nucleus generating operation is performed at the same time. That is, the lower connecting pipe (52)
A part of the refrigerant flowing through the ice nucleus generator (46) is introduced into the ice nucleus generator (46) through the ice nucleation refrigerant introduction pipe (58). Thereby, continuous ice making can be performed. And this ice nucleus generator (46)
In the same manner as in the ice nucleation operation described above, the refrigerant that has cooled the water to generate ice nuclei passes through the ice nucleation refrigerant outlet pipe (59) and the suction gas line (10c) to the suction side of the compression mechanism (1). Will be returned.

At the same time, an auxiliary gas line (31)
A part of the refrigerant flowing through the ice is supplied to the ice progress preventing device (47), and prevents the progress of ice in the same manner as described above. As a result, the progress of the ice reaches the heat storage heat exchanger (42), in which the supercooled state of the supercooled water is eliminated, and the heat storage heat exchanger (4) is released.
2) is prevented from freezing.

The supercooled water generated by the heat storage heat exchanger (42) by performing such water and refrigerant circulation operation includes:
In the vicinity of the ice nucleus generator (46), the ice nuclei from the ice nucleus generator (46) are mixed and introduced into the supercooling canceller (43) in this state. Then, in the supercooling canceller (43), the supercooled water is released from the supercooled state around the ice nucleus with the swirling flow, thereby producing slurry-like ice for heat storage. This ice is collected in the heat storage tank (T) and stored in the heat storage tank (T).

At this time, whether or not the supercooling elimination operation is performed in the supercooling eliminator (43) is determined by the supercooling water temperature sensor (Th-W3) and the ice formation detecting sensor (Th-W4). This is performed according to the detected water temperature. In other words, when a good ice making operation is being performed, the supercooled water temperature sensor (Th-
In W3), the supercooled water temperature (for example, -2 ° C) is detected, and in the ice formation detection sensor (Th-W4), the supercooling is eliminated and the water temperature in which ice and water are mixed (for example, 0 ° C) is detected. Then, it can be confirmed that the supercooling elimination operation is being performed by detecting these water temperatures by the respective sensors (Th-W3, Th-W4).

The compression mechanism in the cold heat storage operation
The capacity control of (1) is performed so that the water temperature detected by the supercooling water temperature sensor (Th-W3) is maintained at a predetermined temperature (for example, −2 ° C. described above). In addition, during the main operation, relatively high-temperature refrigerant flows into the preheater (40), so that ice temporarily flows out of the heat storage tank (T) into the water pipe (45), and this flows out of the preheater (40). ), The preheater (4
The ice and the water heated in (0) are stirred in the mixer (41) to melt the ice, and to prevent the ice from being mixed into the heat storage heat exchanger (42) while preventing the ice from being mixed. The operation of generating the supercooled water in (42) is performed favorably, and the supercooled water is not released from the supercooled state until it reaches the supercooled canceller (43). In other words, the heat storage heat exchanger (42)
As a result, freezing caused by eliminating supercooling is avoided.

-Thawing operation- In the cold storage operation as described above, if the supercooling of the water in the heat storage heat exchanger (42) is eliminated and the heat storage heat exchanger (42) freezes, Temporarily suspend the heat storage operation and switch to the thawing operation. In this thawing operation, the second outdoor electric expansion valve (52a), the third, fourth, and sixth solenoid valves (SV3, SV4, SV6)
Is opened, and the other electric expansion valves and solenoid valves are closed. In this state, the compression mechanism (1) is driven, and the high-temperature gas refrigerant from the compression mechanism (1) is supplied to the lower connecting pipe (52) by the hot gas supply pipe (54) as shown by an arrow in FIG. Then, a part is introduced into the refrigerant circulation space (48c) of the heat storage heat exchanger (42) through the lower connection pipe (52), and the other is introduced into the preheater (40). And the refrigerant (hot gas) introduced into the heat storage heat exchanger (42)
Melts the ice in the heat storage heat exchanger (42) by the heat. At this time, if the pump (P) of the water circulation circuit (B) is driven, the ice is slightly melted, and the ice is stored in the heat storage heat exchanger (42) by the water pressure from the pump (P). The water is easily separated from the wall surface of the water path and is washed away toward the supercooling canceller (43). Then, this refrigerant passes through the upper connection pipe (51) and the suction gas line (10c), and the compression mechanism (1)
Is returned to the suction side. On the other hand, the refrigerant introduced into the preheater (40) is supplied to the thawing bypass line (50) and the suction gas line (10
Through c), it is returned to the suction side of the compression mechanism (1). Also at this time, the upper connection pipe (51) functions as a refrigerant outlet pipe that guides the refrigerant in the refrigerant circulation space (48c) of the heat storage heat exchanger (42).

In the cold storage operation, the heat storage heat exchanger (4
The operation for detecting that the subcooling water temperature sensor (T-W3) is frozen when the water temperature detected by the supercooling water temperature sensor (Th-W3) suddenly rises from −2 ° C. to 0 ° C.
It is determined that ice has been generated by performing the supercooling elimination operation on the upstream side of h-W3), and the thawing operation described above is performed for a predetermined time (for example, 5 minutes). In addition, as an operation for starting the thawing operation, when the flow rate of the water detected by the flow switch (SW-F) becomes equal to or less than a predetermined value,
It is determined that ice blocks part of the water circulation circuit (B), and in this case also, the thawing operation is performed to melt the ice. When the thawing operation is completed, the cold storage operation is started again.

-Simultaneous operation of cooling and heat storage / cooling-This operation mode is a mode in which the heat storage tank is cooled while performing indoor cooling.
The operation of storing ice in (T) is performed in a state where the cooling load is relatively small.

In this operation mode, the operation is performed by opening the indoor electric expansion valves (6, 6, 6) in the cold storage operation described above. That is, as indicated by arrows in FIG. 9, a part of the refrigerant condensed in the outdoor heat exchanger (3) and the auxiliary heat exchanger (30) is supplied to the indoor unit (Y, Y, Y), and Expansion valve
After the pressure is reduced at (6,6,6), it is evaporated by the indoor heat exchanger (7,7,7). And this gas refrigerant is gas pipe
(15), is returned to the suction side of the compression mechanism (1) via the four-way switching valve (2) and the suction gas line (10c). The other water and refrigerant circulation operations are the same as in the cold storage operation described above.

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

In this operation mode, the four-way switching valve (2) is switched to the solid line side by the controller (70), the indoor electric expansion valves (6, 6, 6) are adjusted to a predetermined opening, and the second outdoor While the electric expansion valve (52a) is fully opened, the first outdoor electric expansion valve (5) is closed. In addition, the fifth, sixth, and seventh solenoid valves (S
V5, SV6, SV7) are opened, and the other solenoid valves are closed.

In this state, in the water circulation circuit (B),
The pump (P) is driven to circulate water in the water circulation circuit (B). As a result, the water circulation circuit (B) has a heat storage tank
The cold water cooled by the ice in (T) circulates. On the other hand, in the refrigerant circuit (A), the compression mechanism (1)
As a result, the refrigerant discharged from the compression mechanism (1) partially becomes a four-way switching valve (2) as shown by an arrow in FIG.
Is introduced into the outdoor heat exchanger (3) through the outdoor heat exchanger (3).
In the above, heat exchange is performed with the outside air to condense. Thereafter, the refrigerant is supplied to the first liquid line (11a), the receiver (4),
It flows toward the indoor unit (Y, Y, Y) via the heat storage bypass pipe (53), the lower connecting pipe (52), and the third liquid line (11c). In addition, some other refrigerant flows through the hot gas supply pipe (54) and the heat storage supply pipe (55), bypassing the four-way switching valve (2) and the outdoor heat exchanger (3), and performing heat storage heat exchange. The heat is exchanged with the cold water circulating in the water circulation circuit (B) to condense the water, and is introduced into the lower connecting pipe (52). The refrigerant introduced into the lower connecting pipe (52) joins the third liquid line (11c) and flows toward the indoor unit (Y, Y, Y). The refrigerant that has reached the indoor unit (Y, Y, Y) is depressurized by the indoor electric expansion valves (6, 6, 6), and then evaporated by the indoor heat exchanger (7, 7, 7). The gas is returned to the suction side of the compression mechanism (1) through the gas pipe (15) and the suction gas line (10c). In this manner, the indoor cooling operation using the cold heat of the ice stored in the heat storage tank (T) is performed.

In the cooling operation utilizing the cold storage heat, if the water temperature detected by the supercooling water temperature sensor (Th-W3) reaches a predetermined temperature (for example, 5 ° C.), the second outdoor electric expansion valve is operated. (52a), the fifth, sixth and seventh solenoid valves (SV5, S5
V6 and SV7) are closed, and the second solenoid valve (SV2) is opened to terminate the cold storage utilizing cooling operation and switch to normal cooling operation. In other words, after the supercooled water temperature sensor (Th-W3) detects that most of the cold heat in the heat storage tank (T) has been used, the operation is switched to the normal cooling operation.

-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, the four-way switching valve (2) is switched to the broken line side by the controller (70), the first outdoor electric expansion valve (5) is adjusted to a predetermined opening degree, and the second outdoor electric expansion valve is adjusted. The valve (52a) and the seventh solenoid valve (SV7) are opened, while the other electric expansion valves and solenoid valves are closed.

In this state, 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 the hot gas supply pipe (54) as shown by an arrow in FIG.
Then, the heat is supplied to the heat storage heat exchanger (42) through the heat storage supply pipe (55), where the heat is exchanged with water in the water circulation circuit (B) to heat and condense the water. The refrigerant is supplied to the lower connecting pipe (52), the third liquid line (11c), and the fourth liquid line (11d).
Through the second liquid line (11b) and the heating liquid line (33),
After the pressure is reduced by the first outdoor electric expansion valve (5), the outdoor heat exchanger
Introduced in (3). Then, in the outdoor heat exchanger (3), heat is exchanged with the outside air to evaporate, and then the air passes through the four-way switching valve (2) and the suction gas line (10c) to the suction side of the compression mechanism (1). Will be returned. By performing the circulation operation of the water and the refrigerant, the water flowing through the water circulation circuit (B) receives heat from the refrigerant in the heat storage heat exchanger (42), becomes high-temperature hot water, and enters the heat storage tank (T). Will be stored.

During such a heat storage operation, when the water temperature detected by the inlet water temperature sensor (Th-W1) reaches a predetermined high temperature (for example, 35 ° C.), the heat storage tank
Judging that sufficient heat has been stored in (T), the operation is terminated.

-Simultaneous operation of heat storage / heating- This operation mode is a mode in which the heat storage tank is heated while heating the room.
(T) is an operation for storing hot water, which is performed in a state where the heating load is relatively small.

In this operation mode, the operation is performed by opening the indoor electric expansion valves (6, 6, 6) in the above-mentioned warm heat storage operation. That is, as shown by the arrow in FIG. 12, a part of the refrigerant discharged from the compression mechanism (1) is introduced into the indoor heat exchanger (7, 7, 7) through the gas pipe (15), and this indoor heat exchange is performed. The heat is exchanged with the room air in the chambers (7, 7, 7) to heat and condense the room air, and then join the refrigerant in the third liquid line (11c). The other water and refrigerant circulation operations are the same as in the above-described warm heat storage operation.

-Heating Operation Utilizing Warm Heat Storage-In this operation mode, indoor heating is performed while utilizing the heat of warm water stored in the heat storage tank (T) in the above-described warm heat storage operation.

In this operation mode, the four-way switching valve (2) is switched to the broken line side by the controller (70), the first outdoor electric expansion valve (5) is adjusted to a predetermined opening, and the indoor electric expansion is adjusted. The valve (6,6,6) and the second outdoor electric expansion valve (52a) are fully opened. Further, the fourth solenoid valve (SV4) is opened, and the other solenoid valves are closed.

When the compression mechanism (1) is driven in this state, the refrigerant discharged from the compression mechanism (1) passes through the four-way switching valve (2) and the gas pipe (15) as shown by arrows in FIG. After being introduced into the indoor unit (Y, Y, Y), the indoor heat exchanger (7, 7, 7) exchanges heat with the indoor air to condense and heat the indoor air. Thereafter, the refrigerant is supplied to the third liquid line (11c).
Then, the pressure reaches the receiver (4) via the fourth liquid line (11d), and is reduced from the receiver (4) via the second liquid line (11b) by the first outdoor electric expansion valve (5). Thereafter, part of this refrigerant is introduced into the refrigerant circulation space (48c) of the heat storage heat exchanger (42) via the second liquid line (11b) and the lower connection pipe (52), where After heat exchange and evaporation, the upper connecting pipe
(51) and the suction gas line (10c), and is collected on the suction side of the compression mechanism (1). Also at this time, the upper connection pipe (51) functions as a refrigerant outlet pipe for extracting the refrigerant from the inside of the refrigerant inflow portion (48c) of the heat storage heat exchanger (42).

Then, another part of the refrigerant decompressed by the first outdoor electric expansion valve (5) is introduced into the outdoor heat exchanger (3) through the heating liquid line (33), and this outdoor heat exchanger (3) 3) After evaporating by performing heat exchange with outdoor air in
(2) and is returned to the suction side of the compression mechanism (1) through 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.

In the heating operation utilizing the heat storage energy, the water temperature detected by the inlet water temperature sensor (Th-W1) reaches the predetermined temperature (for example, 20 ° C.) as in the heating operation utilizing the cold storage energy. The second outdoor electric expansion valve (52
a) and the fourth solenoid valve (SV4) are closed to end the heating operation using the heat storage, and the operation shifts to the normal heating operation. That is,
The heat storage tank is detected by detecting the water temperature of the inlet water temperature sensor (Th-W1).
After it is determined that most of the heat in (T) has been used, the operation is switched to the normal heating operation.

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

The operation characteristic of the present embodiment is the operation inside the heat storage heat exchanger (42) during the cold storage operation and the simultaneous cold storage / cooling operation. That is, as described above, in these operating states, the superheat degree of the refrigerant flowing through the upper connection pipe (51) detected by the superheat degree detection sensor (Th-SH1) is detected by the wetness control means (72). The opening of the second outdoor electric expansion valve (52a) is controlled so as to be 0 deg. In other words, the second refrigerant is discharged from the refrigerant heat exchange section (42a) to the upper connection pipe (51) so as not to have a degree of superheat.
The opening degree of the outdoor electric expansion valve (52a) is adjusted, and control is performed so that the refrigerant on the outlet side of the refrigerant heat exchange section (42a) becomes wet steam. As a result, the refrigerant mixed with the droplets flows through the upper connection pipe (51).

By performing such a wet operation, problems such as those in the case of performing a dry operation in which a superheated refrigerant is discharged from a refrigerant heat exchanging section as in the related art are eliminated. In other words, in this dry operation, when the liquid refrigerant flows out of the subcooling heat exchanger at the start of the ice making operation or the like, the electric expansion valve is rapidly throttled, and the evaporation temperature of the refrigerant in the refrigerant heat exchange section rapidly decreases. Or the accuracy of the superheat sensor is insufficient, and although the refrigerant derived from the refrigerant circulation space has the superheat, it is determined that the superheat has not yet been obtained, and the opening of the electric expansion valve is reduced. As a result, the evaporating temperature of the refrigerant decreases, which may cause the water passage to be blocked due to the generation of ice.However, if the wet operation as in the present embodiment is performed, such a situation may occur. Can be avoided, and the reliability of the ice making operation can be improved. Further, since it is not necessary to give the superheat degree to the derived refrigerant, it is not necessary to set the gas-liquid interface of the refrigerant to be low, and it is a storage region of the liquid refrigerant that utilizes the latent heat change of the refrigerant to generate the supercooled water. A large heat exchange area for supercooling can be secured, and ice making efficiency is improved. Further, as the position of the gas-liquid interface can be raised, the lubricating oil for compressor lubrication staying in the vicinity of the gas-liquid interface can be easily returned to the compressor from the upper connection pipe (refrigerant outlet pipe). Reliability can be improved.

Also, as described above, the lower connecting pipe (52)
When the second outdoor electric expansion valve (52a) is in the fully opened state,
Since the inner diameter is set so that the refrigerant flowing through the refrigerant heat exchange section (42a) does not overheat, the expansion valve (52a) is fully opened due to, for example, failure of the second outdoor electric expansion valve (52a). In this case, the refrigerant pressure of the refrigerant heat exchange section (42a) is governed by the pipe diameter of the lower connection pipe (52), but even in such a situation, the refrigerant heat exchange section (4
The outlet side refrigerant in 2a) is maintained in a wet state.

-Experimental Example- Next, the result of an experiment performed to confirm the effect of the present embodiment will be described. In this experiment, in the case where the wet operation was performed as in the above-described embodiment and in the case where the dry operation was performed as in the related art, the superheated water generation capacity was set to be the same in the refrigerant heat exchange unit. The measurement was performed by measuring the changing state of the refrigerant evaporation temperature (42a).

FIG. 14 shows the result. In the figure, the solid line shows the result of the control of this embodiment, and the broken line shows the result of the conventional control. As can be seen from this figure, in the dry operation according to the conventional example, the evaporation temperature sharply decreases immediately after the start of the ice making operation, and the evaporation temperature is relatively low thereafter. The reason is presumed to be as described above (throttle action of the motor-operated valve). On the other hand, in the wet operation of the present embodiment, the temperature does not drop sharply as in the dry operation at the start of the ice making operation, and the temperature thereafter is higher than in the dry operation. That is, according to this wet operation, a predetermined ice making capacity can be maintained even at a relatively high evaporation temperature, and according to the present experiment, according to the present invention, freezing inside the heat storage heat exchanger is suppressed. This means that reliable ice making can be performed.

-Modification- Hereinafter, a modification according to the present invention will be described. Here, only differences from the above-described embodiment will be described.

As shown in FIG. 15, the configuration of this modification is such that the second outdoor electric expansion valve (52) in the lower connecting pipe (52) is provided.
a) and a part of the upper connecting pipe (51)
Heat exchange is enabled between the two. This allows the refrigerant flowing through the upper connection pipe (51) to flow into the lower connection pipe (52).
A heating means (65) for applying a predetermined amount of heat to the upper connection pipe (51) to overheat it.

The heating means (6) in the upper connection pipe (51)
On the downstream side of 5), a superheat detection sensor (Th-SH2) for detecting the superheat of the refrigerant is provided. actually,
As described above, the degree of superheat is determined by the degree of superheat detection sensor (Th-SH
It is calculated from the temperature detected by 2) and the pressure detected by the low pressure sensor (SEN-L).

As shown by the broken line in FIG. 1, the controller (70) receives the output of the superheat degree detection sensor (Th-SH2), and the superheat degree and heating means (65) connect the lower connecting pipe (Th-SH2). The heat storage heat exchanger (42) based on the amount of heat given to the refrigerant of (52)
Determining means (73) for determining whether the refrigerant derived from the above is in a wet state. The amount of heat given to the refrigerant in the lower connection pipe (52) by the heating means (65) depends on the compression mechanism.
It can be obtained from the operating capacity of (1) and the temperature difference between the pipes (51, 52). Then, based on the determination of the determination means (73), the wetness control means (72) is such that the refrigerant derived from the heat storage heat exchanger (42) is in a predetermined wet state, that is, the determination means (73)
However, the opening of the expansion valve (52a) is adjusted so as to determine that the refrigerant derived from the heat storage heat exchanger (42) is in a wet state.

As described above, according to this embodiment, the heat storage heat exchanger (4
A predetermined amount of heat is given to the refrigerant derived from 2) to bring it into a superheated state, and by detecting the degree of superheat, the heat storage heat exchanger (4
Since the dryness of the refrigerant at the outlet of (2) can be recognized, if the refrigerant at the outlet of the heat storage heat exchanger (42) is set to a wet saturated state, highly efficient supercooled water can be obtained. Can be generated.

As another modified example, a capillary tube having a predetermined flow path diameter (not shown) may be provided in place of the second outdoor electric expansion valve (52a). The reason for this is that in the apparatus according to this example, the amount of water circulated in the water circulation circuit (B) and the required degree of supercooling hardly change during the cold storage operation, so the lower connection pipe (52 Since no particular problem occurs even if the degree of decompression of the refrigerant flowing through the capillary tube is constant, such a capillary tube can be applied.

For the same reason, when the second outdoor electric expansion valve (52a) whose opening is freely adjustable as described above is used,
In the steady state of the cold heat storage operation, the expansion valve (52a) may be fixed at a fixed opening, whereby the control operation can be simplified.

In the above-described embodiments and modifications, water is used as the heat storage medium for heat storage. However, a brine solution or the like may be used. Also, the case where the present invention is applied to an ice heat storage device for an air conditioner has been described, but the present invention is also applicable to other devices utilizing cold storage heat.

[0120]

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 is supercooled by the supercooling heat exchanger, and the superheated state is eliminated. Since the refrigerant temperature is kept at the evaporation temperature so that the outlet side refrigerant of the exchange unit becomes wet vapor, it is possible to suppress a decrease in the refrigerant evaporation temperature, which has been a problem in the conventional dry operation, and to provide a subcooling heat exchanger. Is prevented, and the reliability of the ice making operation and the ice making efficiency can be improved.

According to the second aspect of the present invention, the expansion mechanism is an expansion valve whose opening can be adjusted, and the opening of the expansion valve is adjusted to maintain the refrigerant temperature at the evaporation temperature. The configuration and control operation for obtaining the effect according to the first aspect of the present invention can be embodied, and the practicality of the device can be improved.

According to the third aspect of the present invention, the opening of the expansion valve is adjusted by setting the target value of the degree of superheating of the refrigerant derived from the subcooling heat exchanger to 0 deg. The control operation for turning the side refrigerant into wet steam can be further embodied.

According to the fourth aspect of the present invention, it is determined whether or not the refrigerant derived from the supercooling heat exchanger is in a wet state by superheating the refrigerant derived from the supercooling heat exchanger. Since the degree of opening of the expansion valve is adjusted so that the refrigerant is in a predetermined wet state based on this, it is possible to perform a highly efficient operation of generating supercooled water by setting the derived refrigerant to a wet saturated state. it can.

According to the fifth aspect of the present invention, the means for superheating the refrigerant derived from the supercooling heat exchanger can be embodied, and no special heat source is required. A highly practical heating means can be obtained.

In the sixth aspect of the present invention, the degree of pressure reduction of the refrigerant by the expansion mechanism is kept constant. In particular, in the device according to the present invention, the amount of circulation of the heat storage medium circulating in the heat storage circulation circuit and the required degree of supercooling hardly change, so that even if the degree of pressure reduction is constant as the expansion mechanism, there is no problem. Since the degree of pressure reduction can be kept constant, the control operation can be simplified, and a capillary tube can be used as the expansion mechanism.

[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 cross-sectional view showing the internal structure of the heat storage heat exchanger.

FIG. 4 is a circuit diagram showing a refrigerant circulation operation in a normal cooling operation.

FIG. 5 is a circuit diagram showing a refrigerant circulation operation in a normal heating operation.

FIG. 6 is a circuit diagram showing a refrigerant circulation operation of the ice nucleus generation operation.

FIG. 7 is a circuit diagram showing a refrigerant circulation operation of the cold storage operation.

FIG. 8 is a circuit diagram showing a refrigerant circulation operation of a thawing operation.

FIG. 9 is a circuit diagram showing a refrigerant circulation operation of the cold storage / cooling simultaneous operation.

FIG. 10 is a circuit diagram showing a refrigerant circulation operation in a cooling operation utilizing cold storage heat.

FIG. 11 is a circuit diagram showing a refrigerant circulation operation of the heat storage operation.

FIG. 12 is a circuit diagram showing a refrigerant circulation operation of the simultaneous heat storage / heating operation.

FIG. 13 is a circuit diagram showing a refrigerant circulation operation of the heating operation using the heat storage.

FIG. 14 is a diagram showing the results of an experiment performed to confirm the effects of the present invention.

FIG. 15 is a diagram corresponding to FIG. 3 in a modified example.

[Explanation of symbols]

 (1) Compressor (3) Outdoor heat exchanger (heat source side heat exchanger) (8) Refrigerant piping (42) Heat storage heat exchanger (supercooling heat exchanger) (42a) Refrigerant heat exchange part (42b) Heat storage medium Heat exchange part (45) Circulation pipe (48) Vessel (48c) Refrigerant circulation space (49) Heat transfer pipe (51) Upper connection pipe (refrigerant outlet pipe) (52) Lower connection pipe (refrigerant introduction pipe) (52a) Second Outdoor electric expansion valve (expansion mechanism) (65) Heating means (71) Ice making operation means (72) Wetness control means (73) Judgment means (A) Refrigerant circulation circuit (B) Water circulation circuit (C) Floating space (P) Pump (Circulation means) (T) Heat storage tank

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F24F 5/00 F25C 1/00

Claims (6)

(57) [Claims] A plurality of heat transfer tubes (49) extending up and down are placed in a container (4).
8), each heat transfer tube in the container (48).
The outside of (49) is configured as a refrigerant heat exchange section (42a) and each heat transfer tube
(49) Subcooling inside the heat storage medium heat exchange part (42b)
Rejection heat exchanger (42), compressor (1), heat source side heat exchanger (3), expansion mechanism (52a)
When, the refrigerant circulation circuit which the refrigerant heat exchanger and a (42a) which are connected to be capable of circulating refrigerant through refrigerant piping (8) of the supercooling heat exchanger (42) (A), for storing the heat storage medium The heat storage tank (T), the circulating means (P) for pumping the heat storage medium, and the heat storage medium heat exchange section (42b) of the subcooling heat exchanger (42) circulate the heat storage medium by the circulation pipe (45). The heat exchange circuit (B), which is connected as possible, the refrigerant flowing through the refrigerant heat exchange section (42a) and the liquid phase heat storage medium flowing through the heat storage medium heat exchange section (42b) exchange heat and evaporate. After the heat storage medium is cooled to a supercooled state by the refrigerant, and the heat storage medium is led out of the subcooling heat exchanger (42), the supercooled state is eliminated to generate ice, and the ice is stored in the heat storage tank.
Ice making operation means (71) for performing ice making operation to be recovered by (T)
Ice heat storage means for maintaining the refrigerant temperature at the evaporation temperature so that the refrigerant on the outlet side of the refrigerant heat exchange section (42a) becomes wet vapor during the ice making operation. apparatus. The expansion mechanism is an expansion valve whose opening is adjustable.
2. The ice heat storage device according to claim 1, wherein the humidity control means (72) adjusts the opening of the expansion valve (52a). 3. A superheat degree detecting means (Th-SH1) for detecting a superheat degree of the refrigerant derived from the supercooling heat exchanger (42), and the wetness control means (72) includes the superheat degree detecting means (Th-SH1). -SH1) output, and the derived superheat target value of the refrigerant is set to 0deg.
3. The ice heat storage device according to claim 2, wherein the degree of opening of the expansion valve (52a) is adjusted. 4. A heating means (65) for giving a predetermined amount of heat to the refrigerant derived from the supercooling heat exchanger (42) to heat the refrigerant, and a superheat degree detecting means (Th) for detecting the degree of superheat of the refrigerant superheated by the heating. -SH2) and the output of the superheat degree detecting means (Th-SH2), and is derived from the supercooling heat exchanger (42) based on the superheat degree and the amount of heat given to the refrigerant by the heating means (65). Determination means (73) for determining whether or not the refrigerant is in a wet state, wherein the humidity control means (72) receives the output of the determination means (73),
3. The ice heat storage device according to claim 2, wherein the degree of opening of the expansion valve (52a) is adjusted so that the refrigerant derived from the supercooling heat exchanger (42) has a predetermined wet state. 5. The heating means (65) comprises: a high-temperature refrigerant flowing through a refrigerant pipe (8) upstream of the expansion valve (52a);
5. The ice heat storage device according to claim 4, wherein heat is exchanged with the refrigerant derived from 2). 6. The ice heat storage device according to claim 1, wherein the wetness control means (72) keeps the degree of pressure reduction of the refrigerant by the expansion mechanism (52a) constant.