JP2000055495A - Air conditioner provided with ice heat storage tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform good cooling operation utilizing cold heat of ice in an ice heat storage tank. SOLUTION: In an air conditioner 20 comprising a heat source side unit 21 provided with a compressor 28 and a heat source side heat exchanger 30, an ice heat storage unit 22 with a coil 34 arranged in submerged state in an ice heat storage tank 35, and a using side unit 23 provided with a using side heat exchanger 32, and provided with the ice heat storage tank for ice making operation and cooling operation, surge tanks 43A and 43B for storing refrigerant are arranged in parallel between the coil in the ice heat storage tank and the using side heat exchanger, liquid refrigerant condensed in the coil is stored in the above tank, the stored liquid refrigerant is force-fed to the using side heat exchanger by high pressure gas refrigerant alternately supplied into the tank, and the alternate supply of the high pressure gas refrigerant is switched over based on the temperature of the refrigerant flowing out from the inside of the above tank detected by a third temperature sensor 63.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having an ice heat storage tank, and more particularly to an air conditioner having an ice heat storage tank for performing cooling and cooling operation by radiating cold stored in an ice heat storage unit. Related to the device.

[0002]

2. Description of the Related Art Generally, as shown in FIG.
A heat source side unit 5 including a heat source side heat exchanger 2, a four-way valve 3 and an electric expansion valve 4, and an ice capable of forming ice on the outer periphery of the coil 7 with a coil 7 disposed in a submerged state in an ice heat storage tank 6. An air conditioner 11 having a heat storage unit 8 and a use side unit 10 including a use side heat exchanger 9 and capable of performing an ice making operation, a cooling / cooling operation, and a normal cooling operation is known.

[0003] In the ice making operation, the gas refrigerant from the compressor 1 passes through the heat source side heat exchanger 2 to become a liquid refrigerant, and then flows through the electric expansion valve 4 into the coil 7 in the ice heat storage tank 6 to evaporate. After the ice making operation is performed in the ice heat storage tank 6, the gas refrigerant is returned to the compressor 1 for execution.

In the cooling / cooling operation, the compressor 1 of the heat source side unit 5 is stopped, and a circulating pump 12 such as a liquid pump or a gas pump installed in the ice heat storage unit 8 for pumping the refrigerant.
(In FIG. 3, the liquid pump for pumping the liquid refrigerant is operated). That is, by the operation of the circulation pump 12, the liquid refrigerant that has absorbed and condensed the cold stored in the ice in the coil 7 of the ice heat storage tank 6 of the ice heat storage unit 8 is pumped to the use-side heat exchanger 9, User side heat exchanger 9
, The liquid refrigerant evaporates, and the cooling / cooling operation is performed by the latent heat of evaporation and the heat radiation of the cold heat of ice.

In the normal cooling operation, the refrigerant that has been guided from the compressor 1 to the heat source side heat exchanger 2 and becomes a liquid refrigerant flows to the use side heat exchanger 9 without flowing into the coil 7 of the ice heat storage tank 6. The liquid refrigerant is supplied to evaporate the liquid refrigerant, and the operation is performed by the latent heat of evaporation.

[0006]

In the cooling / cooling operation described above, cavitation may occur in the circulation pump 12, particularly when the circulation pump 12 is a liquid pump. Therefore, without using this liquid pump, a plurality of condensed liquid refrigerants in the coil 7 of the ice heat storage tank 6 (for example, 2
), And the high-pressure gas refrigerant is alternately supplied into these tanks, whereby the liquid refrigerant condensed in the tank is pressure-fed to the use side heat exchanger 9 to perform a cooling / cooling operation. Can be implemented.

However, in this case, if the timing for alternately supplying the high-pressure gas refrigerant into the plurality of tanks is shifted, the liquid refrigerant in the tank is continuously pressure-fed to the use-side heat exchanger 9 without any delay. Therefore, the cooling / cooling operation using the cold heat of the ice may not be satisfactorily performed.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and provides an air conditioner having an ice heat storage tank capable of performing a cooling operation using the cold heat of ice in the ice heat storage tank. To provide.

[0009]

According to the first aspect of the present invention,
A heat source side unit including a compressor and a heat source side heat exchanger,
An ice heat storage unit in which a coil is disposed in a submerged state in an ice heat storage tank and ice can be formed on the outer periphery of the coil, and a use-side unit having a use-side heat exchanger, and perform an ice making operation and a cooling operation. In an air conditioner having an ice heat storage tank to be enabled, a plurality of tanks capable of storing a refrigerant are arranged in parallel between the coil and the use side heat exchanger in the ice heat storage tank. The liquid refrigerant condensed in the coil is stored in the tank, and is configured to be able to be pressure-fed to the use side heat exchanger by a high-pressure gas refrigerant alternately supplied into these tanks. The alternate supply into the tank is switched based on the temperature of the refrigerant flowing out of the tank.

According to a second aspect of the present invention, in the first aspect of the present invention, the alternate supply of the high-pressure gas refrigerant into the tank is based on the temperature of the refrigerant flowing out of the tank and the supply of the refrigerant into the tank. The switching is performed when the absolute value of the difference from the temperature of the high-pressure gas refrigerant becomes equal to or lower than a predetermined temperature.

According to a third aspect of the present invention, in the first aspect of the present invention, the alternate supply of the high-pressure gas refrigerant into the tank is such that a temporal change rate of the temperature of the refrigerant flowing out of the tank is a predetermined rate. It is characterized in that it is configured to be switched when the value becomes equal to or more than the value.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the high-pressure gas refrigerant alternately supplied to the plurality of tanks has a larger capacity than the compressor of the heat source side unit. It is a high-pressure gas refrigerant supplied from a small small capacity compressor.

The first to fourth aspects of the present invention have the following effects.

When the temperature of the refrigerant flowing out of the tank is close to the temperature of the condensed liquid refrigerant flowing out of the coil of the ice heat storage tank, the liquid refrigerant exists in the tank, and the refrigerant flowing out of the tank also exists. Is substantially equal to the temperature of the high-pressure gas refrigerant supplied into the tank, it can be determined that no liquid refrigerant exists in the tank. Therefore, by managing the temperature of the refrigerant flowing out of the tank, the liquid level of the liquid refrigerant in the tank can be grasped, and when the liquid refrigerant in one of the tanks does not exist, or immediately before or immediately after the liquid refrigerant no longer exists. Immediately, by pumping the liquid refrigerant from the other tank to the use-side heat exchanger, the liquid refrigerant in the tank can be continuously and reliably pumped to the use-side heat exchanger. Cooling operation using cold heat can be performed well.

In addition, a temperature sensor for detecting the refrigerant temperature is installed on the outflow side of the tank or the like, and a liquid level sensor, which is more expensive than the temperature sensor and directly detects the liquid level of the liquid refrigerant in the tank, is not installed in the tank. Therefore, the cost can be reduced.

[0016]

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

FIG. 1 is a pipeline diagram showing an embodiment of an air conditioner having an ice heat storage tank according to the present invention.

The air conditioner 20 shown in FIG. 1 includes a heat source unit 21, an ice heat storage unit 22, and a use unit 23. The refrigerant pipes 24 of the heat source side unit 21 are connected to the refrigerant pipes 25, 26 of the ice heat storage unit 22.
Is connected to the refrigerant pipe 27 of the use-side unit 23 via the.

The heat source side unit 21 is configured such that a compressor 28, a four-way valve 29, a heat source side heat exchanger 30 and an electric expansion valve 31 are sequentially connected to a refrigerant pipe 24. Further, the use side unit 23 is configured such that the use side heat exchanger 32 and the electric expansion valve 33 are disposed in the refrigerant pipe 27, and the degree of opening of the electric expansion valve 33 is adjusted according to the air conditioning load.

The ice heat storage unit 22 includes an ice heat storage tank 35 accommodating a coil 34,
An on-off valve 36 is provided, and a second on-off valve 37 is provided on the refrigerant pipe 26. Further, the first on-off valve 3 is connected to the refrigerant pipe 25.
One end of the coil 34 is connected to the use side unit 23 side from the disposition position 6 via a connection pipe 38, and an electric expansion valve 39 is disposed on the connection pipe 38. In addition, coil 3
The other end of 4 is connected via a connection pipe 41 provided with a third on-off valve 40 to the use side unit 23 side of the refrigerant pipe 26 where the second on-off valve 37 is provided.

The ice heat storage tank 35 is filled with water and the coil 3
4 is provided in the ice heat storage tank 35 in a state of being submerged. During the ice making operation of the air conditioner 20, the liquid refrigerant flows from the heat source side heat exchanger 30 and evaporates in the coil 34, whereby ice adheres to the outer periphery of the coil 34 and is formed.

Two surge tanks 43A and 43B are connected in parallel to the connection pipe 38 between the electric expansion valve 39 and the coil 34 via a branch pipe 42 that branches into two branches. These surge tanks 43 </ b> A and 43 </ b> B are connected via a merging pipe 44 between the position where the first on-off valve 36 is disposed in the refrigerant pipe 25 and the position where the connection pipe 38 is connected. Thereby, the surge tanks 43A and 43B are disposed between the coil 34 in the ice heat storage tank 35 and the use side heat exchanger 32, and are condensed by the cold stored in the ice in the ice heat storage tank 35. The liquid refrigerant is provided so as to be able to be stored.

In the branch pipe 42, a surge tank 43A,
Inflow side check valves 45A and 45B are provided on the inflow side of 43B, and outflow side check valves 46A and 46B are provided on the merging pipe 44 on the outflow side of the surge tanks 43A and 43B, respectively. These inflow side check valves 45A, 45B are connected to the surge tanks 43A, 43A from the coil 34 of the ice heat storage tank 35.
B, and allows the flow of the refrigerant flowing only to
A and 46B allow the flow of the refrigerant flowing only from the surge tanks 43A and 43B to the use-side heat exchanger 32 side.

The surge tanks 43A and 43B are connected to a first pipe 51, a second pipe 52, a third pipe 53, and a fourth pipe 54.
Is connected to the four-way valve 55 and the small capacity compressor 56. One end of each of the first pipe 51, the second pipe 52, the third pipe 53, and the fourth pipe 54 is connected to each port of the four-way valve 55, and the other ends of the first pipe 51 and the second pipe 52 are connected. It is connected to the discharge port and the suction port of the small capacity compressor 56, respectively. The other ends of the third pipe 53 and the fourth pipe 54 are connected to surge tanks 43A and 43B, respectively.

By the switching operation of the four-way valve 55, the communication between the first pipe 51 and the third pipe 53, the communication between the second pipe 52 and the fourth pipe 54 (switching on the A side), the first pipe 51 and the fourth pipe 54 are performed. And the second pipe 52 and the third pipe 5
3 (B side switching) is selectively switched. The small capacity compressor 56 is a compressor having a smaller capacity (1/10 to 1/20) than the compressor 28 in the heat source side unit 21 and is operated only during the cooling / cooling operation of the air conditioner 20. . The refrigerant discharged from the small capacity compressor 56 has the same composition as the refrigerant discharged from the compressor 28 of the heat source side unit 21.

By switching the four-way valve 55 to the A-side switching or the B-side switching, the high-pressure gas refrigerant from the small capacity compressor 56 can be alternately supplied into the surge tank 43A or 43B. Thus, the liquid refrigerant stored in the surge tanks 43A and 43B is configured to be able to be pressure-fed to the use-side heat exchanger 32.

The surge tanks 43A, 43B are connected to the upstream and downstream pipes of the surge tanks 43A, 43B, respectively.
A first temperature sensor 61, a second temperature sensor 62, a third temperature sensor 63, and a fourth temperature sensor 64 for indirectly detecting the liquid level of the liquid refrigerant in B are provided.

That is, the first temperature sensor 6 is connected to the third pipe 53.
1 is installed, and the surge tank 4
The temperature T1 (FIG. 2) of the high-pressure gas refrigerant discharged into 3A or the low-pressure gas refrigerant sucked from the surge tank 43A into the small capacity compressor 56 is detected. Further, a second temperature sensor 62 is installed in the fourth pipe 54, and the high-pressure gas refrigerant discharged from the small capacity compressor 56 into the surge tank 43B or the small capacity compressor 5 from the surge tank 43B.
The temperature T2 (FIG. 2) of the low-pressure gas refrigerant sucked into 6 is detected.

The junction pipe 44 is provided with a third temperature sensor 63 at its junction to detect the temperature T3 (FIG. 2) of the refrigerant flowing out of the surge tank 43A or 43B. This temperature T3 is the temperature of the condensed liquid refrigerant stored in the surge tank 43A or 43B and pumped to the use side heat exchanger 32, or from the small capacity compressor 56 to the surge tank 43A or 43B. This is the temperature of the high-pressure gas refrigerant that is discharged and flows out.

Further, a fourth temperature sensor 64 is installed at the junction of the branch pipe 42 and the temperature of the condensed liquid refrigerant guided from the coil 34 of the ice heat storage tank 35 into the surge tank 43A or 43B. T4 (FIG. 2) is detected.

The control device 60 shown in FIG. 1 controls the temperatures detected by the first temperature sensor 61, the second temperature sensor 62, the third temperature sensor 63, and the fourth temperature sensor 64 (each temperature T
1, T2, T3, T4) and surge tank 43
The switching of the four-way valve 55 is controlled by detecting the liquid level of the liquid refrigerant in the tanks A and 43B, in particular, the state in which the liquid refrigerant hardly or completely does not exist in the surge tanks 43A and 43B.

That is, when the four-way valve 55 is switched to the A side, the small capacity compressor 5 is installed in the surge tank 43A.
Since the high-pressure gas refrigerant from 6 is discharged and T1> T2, it is necessary to detect the liquid level of the surge tank 43A. While the stored liquid refrigerant is being satisfactorily pumped from the surge tank 43A to the use-side heat exchanger 32, the liquid refrigerant exists in the surge tank 43A, and as shown in FIG. The temperature T3 detected at 63 is
The temperature is close to the temperature T4 detected by the fourth temperature sensor 64. However, when the liquid refrigerant in the surge tank 43A becomes insufficient, the temperature T3 detected by the third temperature sensor 63
Rises, and when the liquid refrigerant no longer exists, the temperature T3 becomes the first temperature.
It becomes almost equal to the temperature T1 detected by the temperature sensor 61. Here, the symbol A in FIG. 2 indicates the liquid level of the liquid refrigerant in the surge tank 43A, and the symbol B indicates the surge tank 43B.
The liquid surface level of the liquid refrigerant in each of them is shown.

Therefore, when the absolute value of the temperature difference (T3-T1) between the temperature T3 and the temperature T1 becomes equal to or lower than the predetermined temperature, the controller 60 determines that almost no liquid refrigerant is present in the surge tank 43A. Alternatively, it is determined that the small-capacity compressor 5 has completely disappeared, and the four-way valve 55
The high-pressure gas refrigerant discharged from 6 is guided into the surge tank 43B, and the liquid refrigerant stored in the surge tank 43B is pumped to the use-side heat exchanger 32.

When the liquid refrigerant is being pumped from the surge tank 43B to the use side heat exchanger 32, the controller 60 determines the temperature between the temperature T3 and the temperature T2 detected by the second temperature sensor 62. The difference (T3-T2) is calculated, and when the absolute value falls below the predetermined temperature, the surge tank 43
It is determined that the liquid refrigerant has hardly or completely no longer existed in B, and the four-way valve 55 is switched to the A side. As a result, the liquid refrigerant stored in the surge tank 43A is pumped to the use-side heat exchanger 32.

The control device 60 switches the four-way valve 55 as described above to alternately pump the liquid refrigerant stored in the surge tank 43A or 43B to the use side heat exchanger 32.

Next, the ice making operation, the cooling / cooling operation, and the normal cooling operation of the air conditioner 20 will be described.

[A] Ice Making Operation The ice making operation of the air conditioner 20 is performed, for example, in a time period when power rates are low from 10:00 at night to 8:00 in the next morning, when the liquid refrigerant from the heat source side heat exchanger 30 is stored in an ice storage tank. In this operation, the ice is supplied into the coil 34 of FIG.

In this case, the electric expansion valve 33 is closed, and the first on-off valve 36, the second on-off valve 37, the third on-off valve 40
The electric expansion valve 39 is opened.

In this state, when the compressor 28 of the heat source side unit 21 is operated, the gas refrigerant discharged from the compressor 28 is condensed in the heat source side heat exchanger 30 and the electric expansion valves 31 and 39 , And flows into the coil 34 of the ice heat storage tank 35. The refrigerant that has flowed into the coil 34 evaporates and forms with ice adhered to the outer periphery of the coil 34. Thereafter, the gas refrigerant in the coil 34 is connected to the connection pipe 41.
And a refrigerant pipe 26 to a four-way valve 29, and a compressor 28
Is returned to.

[B] Cooling / cooling operation The cooling / cooling operation of the air conditioner 20 is performed, for example, in a time zone when the temperature rises in the daytime by liquefaction by the cold heat of the ice in the coil 34 of the ice storage tank 35 and the surge tank. The liquid refrigerant stored in 43A, 43B is supplied to the surge tanks 43A, 43B.
This is performed by pumping from B to the use side heat exchanger 32.

In this case, the first on-off valve 36, the second on-off valve 37 and the electric expansion valve 39 are closed, and the electric expansion valve 33
And the third on-off valve 40 is operated to open. Further, the compressor 28 of the heat source side unit 21 is in a stopped state after the ice making operation is completed.

In this state, the small capacity compressor 56 is operated, and the first temperature sensor 61, the second temperature sensor 62, and the third
Based on the temperature signal from the temperature sensor 63, the control device 60
Performs the switching between the A side and the B side of the four-way valve 55 alternately. For example, the temperature T detected by the third temperature sensor 63
When the absolute value of the temperature difference (T3−T2) between the third temperature T3 and the temperature T2 detected by the second temperature sensor 62 becomes equal to or less than the predetermined temperature, the control device 60 switches the four-way valve 55 from B side switching to A As the side switching, the high-pressure gas refrigerant discharged from the small capacity compressor 56 is guided into the surge tank 43A via the first pipe 51 and the third pipe 53. Thereby, this surge tank 4
The stored liquid refrigerant in 3A flows out of the check valve 46A on the outflow side,
4. The refrigerant flows into the use-side heat exchanger 32 through the refrigerant pipes 25 and 27. The liquid refrigerant stored in the surge tank 43A passes through the coil 34 of the ice heat storage tank 35,
Since it is a liquid refrigerant condensed by the cold heat stored in the ice inside, it evaporates in the use-side heat exchanger 32, thereby efficiently radiating the cold heat of the ice (cooling) and the latent heat of evaporation to make the room more efficient. Cool.

The gas refrigerant evaporated in the use-side heat exchanger 32 passes through the connection pipe 41 and the third on-off valve 40 and is stored in the ice heat storage tank 3.
5 and into the ice heat storage tank 35 as described above.
Is condensed by the ice inside to become a liquid refrigerant, and the inflow-side check valve 4
It flows into the surge tank 43B via 5B.

At this time, since the pressure in the surge tank 43A is high, the liquid refrigerant in the coil 34 of the ice heat storage tank 35 does not flow into the surge tank 43A,
Flows inside. Similarly, since the pressure inside the surge tank 43B is lower than that of the surge tank 43A,
The stored refrigerant in B does not flow out to the use side heat exchanger 32 via the outflow side check valve 46B.

The temperature T detected by the third temperature sensor 63
When the absolute value of the temperature difference (T3−T1) between the third temperature 3 and the temperature T1 detected by the first temperature sensor 61 becomes equal to or lower than the predetermined temperature, the control device 60 switches the four-way valve 55 to the B side to switch The high-pressure gas refrigerant discharged from the displacement compressor 56 is guided into the surge tank 43B via the first pipe 51 and the fourth pipe 54. Then, the liquid refrigerant stored in the surge tank 43B is discharged to the outflow-side check valve 46B, the merging pipe 44, the refrigerant pipe 2
5 and 27 and the use side heat exchanger 32 via the electric expansion valve 33
Then, as described above, the room is efficiently cooled by cooling and latent heat of vaporization. This use side heat exchanger 32
Is condensed by the cold heat of ice in the coil 34 of the ice heat storage tank 35 through the connection pipe 41 and the third on-off valve 40 to become a liquid refrigerant, and is branched into the branch pipe 42 and the inflow-side check valve 4.
It flows into the surge tank 43A via 5A.

The controller 60 switches the four-way valve 55 to the A side when the absolute value of the temperature difference (T3-T2) between the temperatures T3 and T2 becomes equal to or less than the predetermined temperature, and sets the temperature difference between the temperatures T3 and T1. When the absolute value of (T3−T1) becomes equal to or lower than the predetermined temperature, the four-way valve is switched to the B side, and the above operation is repeated to continue the cooling / cooling operation.

[C] Normal Cooling Operation The normal cooling operation of the air conditioner 20 is a cooling operation that is performed without using the cold heat stored in the ice in the ice heat storage tank 35, and includes the electric expansion valve 39 and the third cooling operation. The on-off valve 40 is closed, and the first on-off valve 36, the second on-off valve 37, and the electric expansion valves 31 and 33 are opened.

In this state, when the compressor 28 is operated,
The gas refrigerant discharged from the compressor 28 is condensed in the heat source side heat exchanger 30, and the electric expansion valve 31, the refrigerant pipe 25
After flowing into the use-side heat exchanger 32 through the electric expansion valve 33 and evaporating in the use-side heat exchanger 32 to cool the room by the latent heat of evaporation, the compressor passes through the refrigerant pipe 26 and the four-way valve 29. Returned to 28.

The air conditioner 20 of the above embodiment has the following effects 1 to 3 because it is configured as described above.

First temperature sensor 61, second temperature sensor 6
2. By controlling the temperature of the refrigerant flowing out of the surge tanks 43A, 43B using the third temperature sensor 63 and the fourth temperature sensor 64, the surge tanks 43A, 43B
The level of the liquid refrigerant in the chamber can be ascertained, the temperature T3 detected by the third temperature sensor 63, the second temperature sensor 62
The absolute value of each of the temperature difference (T3-T1) and the temperature difference (T3-T2) is equal to or less than a predetermined temperature based on the temperature T2 detected by the control unit and the temperature T1 detected by the first temperature sensor 61. When it is determined that the liquid refrigerant has completely disappeared in one of the tanks (surge tank 43A or 43B) or immediately before or immediately after it has completely disappeared, the other tank (surge tank 43B or 43A) ), The liquid refrigerant is immediately pressure-fed to the use-side heat exchanger 32. As a result, the liquid refrigerant in the surge tanks 43A and 43B can be continuously and reliably pumped to the use-side heat exchanger 32 without stagnation, and therefore, cooling / cooling using the cold heat of the ice in the ice heat storage tank 35 can be performed. Operation can be performed well.

First temperature sensor 6 for detecting refrigerant temperature
1, the second temperature sensor 62, the third temperature sensor 63, and the fourth
The temperature sensors 64 are installed on the outflow side and the inflow side of the tank, and the liquid level sensors of the liquid refrigerant in the surge tanks 43A and 43B are directly detected. Because we do not install,
Cost can be reduced.

The first temperature sensor 61 and the second temperature sensor 6
2, the temperature of the discharge gas refrigerant and the suction gas refrigerant from the small capacity compressor 56 can be managed, and the temperature of the refrigerant pressure-fed from the surge tank 43A or 43B to the use side heat exchanger 32 can be controlled by the third temperature sensor 63. Can be managed.

Although the present invention has been described based on one embodiment, the present invention is not limited to this.

For example, in the above embodiment, the control device 6
Although 0 is described as managing the absolute value of the temperature difference between the temperature difference (T3-T1) and the temperature difference (T3-T2) and switching the four-way valve 55, the control device 60 ,
When the time rate of change of the temperature T3 (time derivative of the temperature T3) detected by the third temperature sensor 63 becomes equal to or greater than a predetermined value, it is determined that the gas refrigerant, not the liquid refrigerant, has begun to flow into the junction pipe 44. Then, the four-way valve 55 may be switched immediately.

The inflow-side check valves 45A and 45B and the outflow-side check valves 46A and 46B are connected to the inflow-side on-off valves 70A and 70B.
B, may be replaced with the outflow side on-off valves 71A and 71B, respectively. In this case, these inflow-side on-off valves 70A, 70A
B, the outflow side on-off valves 71A and 71B are all closed during the ice making operation and the normal cooling operation. Further, during the cooling / cooling operation, the inflow-side on-off valve 70A and the outflow-side on-off valve 71B open and close in conjunction with each other, and the inflow-side on-off valve 70B and the outflow-side on-off valve 71A operate in conjunction with each other to form the inflow-side on-off valve 70A and the outflow-side Opening / closing operation is performed in reverse to the opening / closing valve 71B. Furthermore, surge tank 4
3A and 43B may be three or more.

[0056]

As described above, a plurality of tanks capable of storing the refrigerant are arranged in parallel between the coil in the ice heat storage tank and the use side heat exchanger, and condensed in the coil. A liquid refrigerant is stored in the tank, and high-pressure gas refrigerant alternately supplied into these tanks is configured to be able to be pressure-fed to the use-side heat exchanger, and alternate supply of the high-pressure gas refrigerant into the tank Is switched based on the temperature of the refrigerant flowing out of the tank, so that at the time when the liquid refrigerant in one of the tanks does not exist or immediately before or immediately after the liquid refrigerant does not exist, immediately from the other tank, the use side heat exchanger Since the liquid refrigerant can be pumped to the cooling medium, the cooling operation using the cold heat of the ice in the ice heat storage tank can be favorably performed.

[Brief description of the drawings]

FIG. 1 is a pipeline diagram showing an embodiment of an air conditioner including an ice heat storage tank according to the present invention.

FIG. 2 is a graph showing a relationship between a refrigerant temperature detected by a temperature sensor and a liquid level of a liquid refrigerant in a surge tank.

FIG. 3 is a pipeline diagram showing an air conditioner provided with a conventional ice heat storage tank.

[Explanation of symbols]

 Reference Signs List 21 heat source side unit 22 ice heat storage unit 23 use side unit 28 compressor 29 four-way valve 32 use side heat exchanger 34 coil 35 ice heat storage tank 43A, 43B surge tank 55 four-way valve 56 small capacity compressor 60 control device 61 first temperature Sensor 62 Second temperature sensor 63 Third temperature sensor 64 Fourth temperature sensor

Claims (4)

[Claims] 1. A heat source unit including a compressor and a heat source side heat exchanger, an ice heat storage unit having a coil disposed in a submerged state in an ice heat storage tank and capable of forming ice on the outer periphery of the coil, A use side unit having a side heat exchanger,
In an air conditioner including an ice heat storage tank capable of performing an ice making operation and a cooling operation, a plurality of tanks capable of storing a refrigerant are provided between the coil and the use side heat exchanger in the ice heat storage tank. The liquid refrigerant condensed in the coil is disposed in a parallel state, is stored in the tank, and is configured to be capable of being pumped to the use side heat exchanger by a high-pressure gas refrigerant supplied alternately into these tanks. An air conditioner having an ice heat storage tank, wherein alternate supply of the high-pressure gas refrigerant into the tank is switched based on the temperature of the refrigerant flowing out of the tank. 2. The method according to claim 1, wherein the alternate supply of the high-pressure gas refrigerant into the tank is performed by setting an absolute value of a difference between a temperature of the refrigerant flowing out of the tank and a temperature of the high-pressure gas refrigerant supplied into the tank to a predetermined value. The air conditioner provided with the ice heat storage tank according to claim 1, wherein the air conditioner is configured to be switched when the temperature becomes lower than the temperature. 3. The method according to claim 1, wherein the alternate supply of the high-pressure gas refrigerant into the tank is switched when a temporal change rate of the temperature of the refrigerant flowing out of the tank becomes a predetermined value or more. An air conditioner comprising the ice heat storage tank according to claim 1. 4. The high-pressure gas refrigerant alternately supplied to the plurality of tanks is a high-pressure gas refrigerant supplied from a small-capacity compressor having a smaller capacity than a compressor of the heat source side unit. Item 4. An air conditioner comprising the ice heat storage tank according to any one of Items 1 to 3.