JP3802238B2 - Air conditioner with ice storage tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner including an ice heat storage tank, and more particularly to an air conditioner including an ice heat storage tank that dissipates cold heat stored in an ice heat storage unit and performs a cooling and cooling operation.
[0002]
[Prior art]
In general, as shown in FIG. 3, a coil 7 is placed in a submerged state in a heat source unit 5 including a compressor 1, a heat source side heat exchanger 2, a four-way valve 3 and an electric expansion valve 4, and an ice heat storage tank 6. It has an ice heat storage unit 8 that can be formed on the outer periphery of the coil 7 and a use side unit 10 equipped with a use side heat exchanger 9, and can perform ice making operation, cooling cooling operation, and normal cooling operation. An air conditioner 11 is known.
[0003]
In the ice making operation, the gas refrigerant from the compressor 1 becomes a liquid refrigerant through the heat source side heat exchanger 2, and then passes through the electric expansion valve 4 to flow into the coil 7 in the ice heat storage tank 6 and evaporate. After the ice making operation is carried out in the heat storage tank 6, the gas refrigerant is returned to the compressor 1 and carried out.
[0004]
In the cooling and cooling operation, the compressor 1 of the heat source side unit 5 is stopped, and the circulating pump 12 such as a liquid pump or a gas pump that is installed in the ice heat storage unit 8 and pumps the refrigerant (in FIG. 3, a liquid pump that pumps the liquid refrigerant). ). That is, the operation of the circulation pump 12 causes the liquid refrigerant condensed by absorbing the cold stored in the ice in the coil 7 of the ice storage tank 6 in the ice storage unit 8 to be pumped to the use side heat exchanger 9. The liquid refrigerant evaporates in the use side heat exchanger 9, and the cooling and cooling operation is performed by the latent heat of evaporation and the heat radiation of ice.
[0005]
In the normal cooling operation, the refrigerant that has been led from the compressor 1 to the heat source side heat exchanger 2 to become liquid refrigerant is supplied to the use side heat exchanger 9 without flowing into the coil 7 of the ice heat storage tank 6. The liquid refrigerant is evaporated, and this latent heat of vaporization is carried out.
[0006]
[Problems to be solved by the invention]
By the way, in the above-described cooling and cooling operation, cavitation may occur in the circulation pump 12 particularly when the circulation pump 12 is a liquid pump. Therefore, without using this liquid pump, the condensed liquid refrigerant in the coil 7 of the ice heat storage tank 6 is stored in a plurality of (for example, two) tanks, and the high-pressure gas refrigerant is alternately supplied into these tanks. Thus, the liquid refrigerant condensed in the tank can be pumped to the use-side heat exchanger 9 so that the cooling and cooling operation can be performed.
[0007]
However, in this case, if the timing for alternately supplying the high-pressure gas refrigerant into the plurality of tanks shifts, the liquid refrigerant in the tank can be continuously pumped to the utilization side heat exchanger 9 without stagnation. Therefore, there is a possibility that the cooling and cooling operation using the cold heat of ice cannot be carried out satisfactorily.
[0008]
The subject of this invention is made in view of the above-mentioned situation, and provides the air conditioning apparatus provided with the ice thermal storage tank which can implement the air_conditioning | cooling operation using the cold of the ice in an ice thermal storage tank favorably. It is in.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a heat source side unit including a compressor and a heat source side heat exchanger, and an ice heat storage unit in which a coil is disposed in a submerged state in an ice heat storage tank so that ice can be formed on the outer periphery of the coil. And an air-conditioning apparatus having an ice heat storage tank capable of performing ice making operation and cooling operation, and the coil in the ice heat storage tank and the utilization A plurality of tanks capable of storing refrigerant are arranged in parallel with the side heat exchanger, and liquid refrigerant condensed in the coil is stored in the tank and supplied alternately to these tanks. The high-pressure gas refrigerant is configured to be capable of being pumped to the use-side heat exchanger, and the 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. It is what.
[0010]
According to a second aspect of the present invention, in the first aspect of the invention, the alternate supply of the high-pressure gas refrigerant into the tank includes the temperature of the refrigerant flowing out of the tank and the high pressure supplied into the tank. The absolute value of the difference from the temperature of the gas refrigerant is configured to be switched when the temperature becomes equal to or lower than a predetermined temperature.
[0011]
The invention according to claim 3 is the invention according to claim 1, wherein the alternating supply of the high-pressure gas refrigerant into the tank is such that the rate of temporal change in the temperature of the refrigerant flowing out of the tank exceeds a predetermined value. It is characterized in that it is configured to be switched at a point in time.
[0012]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the high-pressure gas refrigerant supplied alternately to the plurality of tanks has a small capacity smaller than that of the compressor of the heat source unit. It is a high-pressure gas refrigerant supplied from a compressor.
[0013]
The inventions according to claims 1 to 4 have the following effects.
[0014]
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 is present in the tank, and the temperature of the refrigerant flowing out of the tank is When the temperature of the high-pressure gas refrigerant supplied into the tank is substantially equal, it can be determined that no liquid refrigerant exists in the tank. Therefore, by controlling 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 tank no longer exists, immediately before or after Immediately by pumping the liquid refrigerant from the other tank to the user side heat exchanger, the liquid refrigerant in the tank can be continuously and reliably pumped to the user side heat exchanger. Cooling operation using cold heat can be carried out satisfactorily.
[0015]
In addition, a temperature sensor that detects the refrigerant temperature is installed on the outflow side of the tank, and a liquid level sensor that directly detects the liquid level of the liquid refrigerant in the tank is not installed in the tank. Can be reduced.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a pipe line diagram showing an embodiment of an air conditioner equipped with an ice heat storage tank according to the present invention.
[0018]
The air conditioner 20 shown in FIG. 1 includes a heat source side unit 21, an ice heat storage unit 22, and a use side unit 23. The refrigerant pipe 24 of the heat source side unit 21 is connected to the refrigerant pipe 27 of the usage side unit 23 via the refrigerant pipes 25 and 26 of the ice heat storage unit 22.
[0019]
The heat source side unit 21 is configured by sequentially connecting a compressor 28, a four-way valve 29, a heat source side heat exchanger 30, and an electric expansion valve 31 to a refrigerant pipe 24. The use side unit 23 is configured by arranging a use side heat exchanger 32 and an electric expansion valve 33 in the refrigerant pipe 27, and the opening degree of the electric expansion valve 33 is adjusted according to the air conditioning load.
[0020]
The ice heat storage unit 22 includes an ice heat storage tank 35 in which a coil 34 is accommodated, and a first opening / closing valve 36 is disposed in the refrigerant pipe 25 and a second opening / closing valve 37 is disposed in the refrigerant pipe 26. Furthermore, one end of a coil 34 is connected to the refrigerant pipe 25 via a connection pipe 38 closer to the use side unit 23 side than the position where the first on-off valve 36 is disposed, and an electric expansion valve 39 is connected to the connection pipe 38. Arranged. In addition, the other end of the coil 34 is connected to the use side unit 23 side of the refrigerant pipe 26 at the position where the second on-off valve 37 is disposed via a connection pipe 41 provided with the third on-off valve 40.
[0021]
The ice heat storage tank 35 is filled with water, and the coil 34 is disposed in the ice heat storage tank 35 in a submerged state. In the coil 34, the liquid refrigerant flows from the heat source side heat exchanger 30 and evaporates during the ice making operation of the air conditioner 20, thereby forming ice attached to the outer periphery of the coil 34.
[0022]
Two surge tanks 43 </ b> A and 43 </ b> B are connected in parallel between the electric expansion valve 39 and the coil 34 to the connection pipe 38 through a bifurcated branch pipe 42. These surge tanks 43 </ b> A and 43 </ b> B are connected between the position where the first opening / closing valve 36 is disposed and the connection position of the connection pipe 38 in the refrigerant pipe 25 via the junction pipe 44. Thus, 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. A liquid refrigerant is provided so as to be stored.
[0023]
The branch pipe 42 has inflow side check valves 45A and 45B on the inflow side of the surge tanks 43A and 43B, and the junction pipe 44 has outflow side check valves 46A and 46B on the outflow side of the surge tanks 43A and 43B. Are arranged respectively. These inflow side check valves 45A and 45B allow the flow of refrigerant flowing only from the coil 34 of the ice heat storage tank 35 to the surge tanks 43A and 43B, and the outflow side check valves 46A and 46B are surge tanks 43A and 43B. The flow of the refrigerant that flows only to the use side heat exchanger 32 side is allowed.
[0024]
The surge tanks 43 </ b> A and 43 </ b> B are connected to the four-way valve 55 and the small capacity compressor 56 via the first pipe 51, the second pipe 52, the third pipe 53, and the fourth pipe 54. 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. The small capacity compressor 56 is connected to the discharge port and the suction port, respectively. The other ends of the third pipe 53 and the fourth pipe 54 are connected to the surge tanks 43A and 43B, respectively.
[0025]
By switching the four-way valve 55, communication between the first pipe 51 and the third pipe 53, communication between the second pipe 52 and the fourth pipe 54 (A-side switching), communication between the first pipe 51 and the fourth pipe 54, and Communication between the second pipe 52 and the third pipe 53 (B side switching) is selectively switched. The small capacity compressor 56 is a compressor having a capacity (1/10 to 1/20) smaller than that of the compressor 28 in the heat source side unit 21 and is operated only when the air-conditioning apparatus 20 is allowed to cool and cool. . 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.
[0026]
The high-pressure gas refrigerant from the small capacity compressor 56 can be alternately supplied into the surge tank 43A or 43B by the operation of the four-way valve 55 for switching to the A side or B side. As a result, the liquid refrigerant stored in the surge tanks 43A and 43B is configured to be capable of being pumped to the use side heat exchanger 32.
[0027]
A first temperature sensor 61, a second temperature sensor 62 for indirectly detecting the liquid level of the liquid refrigerant in the surge tanks 43A, 43B on the upstream and downstream piping of the surge tanks 43A, 43B, A third temperature sensor 63 and a fourth temperature sensor 64 are provided.
[0028]
That is, the first temperature sensor 61 is installed in the third pipe 53, and the high pressure gas refrigerant discharged from the small capacity compressor 56 into the surge tank 43A, or the low pressure sucked into the small capacity compressor 56 from the surge tank 43A. The temperature T1 (FIG. 2) of the gas refrigerant is detected. In addition, a second temperature sensor 62 is installed in the fourth pipe 54 and is sucked into the small capacity compressor 56 from the high pressure gas refrigerant discharged from the small capacity compressor 56 into the surge tank 43B or from the surge tank 43B. The temperature T2 (FIG. 2) of the low-pressure gas refrigerant is detected.
[0029]
The joining pipe 44 is provided with a third temperature sensor 63 at the joining portion 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 into the surge tank 43A or 43B. This is the temperature of the high-pressure gas refrigerant that is discharged and flows out.
[0030]
Further, the branch pipe 42 is provided with a fourth temperature sensor 64 at the joining portion thereof, and the temperature T4 of the condensed liquid refrigerant guided from the coil 34 of the ice heat storage tank 35 to the surge tank 43A or 43B (see FIG. 2) is detected.
[0031]
The control device 60 shown in FIG. 1 takes in the detected temperatures (temperatures T1, T2, T3, and T4, respectively) from the first temperature sensor 61, the second temperature sensor 62, the third temperature sensor 63, and the fourth temperature sensor 64, The switching of the four-way valve 55 is controlled by detecting the liquid level of the liquid refrigerant in the surge tanks 43A and 43B, in particular, the state in which there is almost or no liquid refrigerant in the surge tanks 43A and 43B.
[0032]
That is, when the four-way valve 55 is switched to the A side, the high-pressure gas refrigerant from the small capacity compressor 56 is discharged into the surge tank 43A and T1> T2, so the liquid level of the surge tank 43A is reduced. It needs to be detected. While the stored liquid refrigerant is being successfully pumped from the surge tank 43A to the use-side heat exchanger 32, the liquid refrigerant is present in the surge tank 43A. As shown in FIG. The temperature T3 detected at 63 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. When the liquid refrigerant does not exist, the temperature T3 is detected by the first temperature sensor 61. Is approximately equal to the temperature T1 to be applied. 2 indicates the liquid level of the liquid refrigerant in the surge tank 43A, and B indicates the liquid level of the liquid refrigerant in the surge tank 43B.
[0033]
Therefore, the control device 60 has almost no liquid refrigerant in the surge tank 43A 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, or completely. The four-way valve 55 is switched to the B side, the high pressure gas refrigerant discharged from the small capacity compressor 56 is guided into the surge tank 43B, and the liquid refrigerant stored in the surge tank 43B is used on the use side. The pressure is fed to the heat exchanger 32.
[0034]
When the liquid refrigerant is being pumped from the surge tank 43B to the use side heat exchanger 32, the control device 60 detects the temperature difference (T3) between the temperature T3 and the temperature T2 detected by the second temperature sensor 62. -T2) is calculated, and when the absolute value becomes equal to or lower than the predetermined temperature, it is determined that the liquid refrigerant is almost absent or completely absent in the surge tank 43B. A side switching. Thereby, the liquid refrigerant stored in the surge tank 43 </ b> A is pumped to the use side heat exchanger 32.
[0035]
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.
[0036]
Next, the ice making operation, the cooling and cooling operation, and the normal cooling operation of the air conditioner 20 will be described.
[0037]
[A] Ice making operation The ice making operation of the air conditioner 20 is performed by, for example, supplying the liquid refrigerant from the heat source side heat exchanger 30 to the coil of the ice heat storage tank 35 in the time zone where the electricity rate is low from 10:00 to 8:00 the next morning. In this operation, ice is supplied into the ice heat storage tank 35.
[0038]
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, and the electric expansion valve 39 are opened.
[0039]
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 decompressed through 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 is formed with ice attached to the outer periphery of the coil 34. Thereafter, the gas refrigerant in the coil 34 reaches the four-way valve 29 through the connection pipe 41 and the refrigerant pipe 26 and is returned to the compressor 28.
[0040]
[B] Cooling and cooling operation The cooling and cooling operation of the air conditioner 20 is, for example, liquefied by the cold heat of ice in the coil 34 of the ice heat storage tank 35 during the daytime when the air temperature rises, and surge tanks 43A and 43B. The liquid refrigerant stored inside is pumped from the surge tanks 43 </ b> A and 43 </ b> B to the use side heat exchanger 32.
[0041]
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 are opened. Further, the compressor 28 of the heat source side unit 21 is in a stopped state after the ice making operation is finished.
[0042]
In this state, the small capacity compressor 56 is operated, and based on the temperature signals from the first temperature sensor 61, the second temperature sensor 62, and the third temperature sensor 63, the control device 60 switches the A side of the four-way valve 55 and B Perform side switching alternately. For example, when the absolute value of the temperature difference (T3−T2) between the temperature T3 detected by the third temperature sensor 63 and the temperature T2 detected by the second temperature sensor 62 becomes equal to or lower than a predetermined temperature, the control is performed. The device 60 changes the four-way valve 55 from the B side switching to the A side switching, and guides the high-pressure gas refrigerant discharged from the small capacity compressor 56 into the surge tank 43A through the first pipe 51 and the third pipe 53. Thereby, the stored liquid refrigerant in the surge tank 43A flows into the use side heat exchanger 32 through the outflow side check valve 46A, the merging pipe 44, and the refrigerant pipes 25 and 27. The liquid refrigerant stored in the surge tank 43 </ b> A is a liquid refrigerant condensed by the cold heat stored in the ice in the ice heat storage tank 35 through the coil 34 of the ice heat storage tank 35. By evaporating inside, the room is efficiently cooled by heat radiation (cooling) of the ice and the latent heat of evaporation.
[0043]
The gas refrigerant evaporated in the use side heat exchanger 32 flows into the coil 34 of the ice heat storage tank 35 through the connection pipe 41 and the third on-off valve 40, and is condensed by the ice in the ice heat storage tank 35 as described above. The liquid refrigerant then flows into the surge tank 43B via the inflow side check valve 45B.
[0044]
At this time, since the inside of the surge tank 43A is at a high pressure, the liquid refrigerant in the coil 34 of the ice heat storage tank 35 flows into the surge tank 43B without flowing into the surge tank 43A. Similarly, since the pressure in the surge tank 43B is lower than that in the surge tank 43A, the stored refrigerant in the surge tank 43B does not flow out to the use side heat exchanger 32 through the outflow check valve 46B.
[0045]
When the absolute value of the temperature difference (T3−T1) between the temperature T3 detected by the third temperature sensor 63 and the temperature T1 detected by the first temperature sensor 61 becomes equal to or lower than a predetermined temperature, the control device 60 The high-pressure gas refrigerant discharged from the small-capacity compressor 56 is guided into the surge tank 43B through the first pipe 51 and the fourth pipe 54 by switching the four-way valve 55 to the B side. Then, the liquid refrigerant stored in the surge tank 43B flows into the use side heat exchanger 32 through the outflow side check valve 46B, the junction pipe 44, the refrigerant pipes 25 and 27, and the electric expansion valve 33 and evaporates. As described above, the room is efficiently cooled by cooling and latent heat of vaporization. The gas refrigerant from the use side heat exchanger 32 is condensed by the cold heat of the 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 the branch pipe 42 and the inflow side. It flows into the surge tank 43A through the check valve 45A.
[0046]
The control device 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 is equal to or lower than a predetermined temperature, and the temperature difference (T3-T3) between the temperatures T3 and T1. When the absolute value of 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 and cooling operation.
[0047]
[C] Normal Cooling Operation The normal cooling operation of the air conditioner 20 is a cooling operation that is performed without using the cold stored in the ice in the ice heat storage tank 35, and the electric expansion valve 39 and the third 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.
[0048]
When the compressor 28 is operated in this state, 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 and the electric expansion valve 33 are passed through. Then, it flows into the use side heat exchanger 32, evaporates in the use side heat exchanger 32, cools the room by latent heat of evaporation, and then returns to the compressor 28 through the refrigerant pipe 26 and the four-way valve 29.
[0049]
Since the air conditioning apparatus 20 of the above embodiment is configured as described above, the following effects (1) to (3) are achieved.
[0050]
(1) By using the first temperature sensor 61, the second temperature sensor 62, the third temperature sensor 63, and the fourth temperature sensor 64 to manage the temperature of the refrigerant flowing out of the surge tanks 43A, 43B, the surge tank 43A 43B, the liquid level of the liquid refrigerant in 43B can be grasped, the temperature T3 detected by the third temperature sensor 63, the temperature T2 detected by the second temperature sensor 62, and the first temperature sensor 61. When the absolute value of each of the temperature difference (T3-T1) and the temperature difference (T3-T2) is equal to or lower than a predetermined temperature from the temperature T1, the liquid refrigerant is transferred to one tank (surge tank 43A or 43B). It is determined that it is completely absent or just before or after it is completely absent, and the other tank (surge tank 43B or 43A) is directly connected to the use side heat exchanger 32. The liquid refrigerant is pumped into. 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, the cooling cooling using the cold heat of the ice in the ice heat storage tank 35. Driving can be performed well.
[0051]
(2) The first temperature sensor 61, the second temperature sensor 62, the third temperature sensor 63, and the fourth temperature sensor 64 for detecting the refrigerant temperature are installed on the outflow side and the inflow side of the tank, and in the surge tanks 43A and 43B. Since the liquid level sensor that directly detects the liquid level of the liquid refrigerant and is more expensive than the temperature sensor is not installed in the surge tanks 43A and 43B, the cost can be reduced.
[0052]
(3) The temperature of the discharge gas refrigerant and the suction gas refrigerant from the small-capacity compressor 56 can be managed by the first temperature sensor 61 and the second temperature sensor 62, and used from the surge tank 43A or 43B by the third temperature sensor 63. The temperature of the refrigerant pumped to the side heat exchanger 32 can be managed.
[0053]
As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this.
[0054]
For example, in the above-described embodiment, the control device 60 manages the absolute value of each temperature difference between the temperature difference (T3-T1) and the temperature difference (T3-T2), and switches the four-way valve 55. As described above, the control device 60 enters the joining pipe 44 when the temporal change rate of the temperature T3 detected by the third temperature sensor 63 (temporal differentiation of the temperature T3) becomes a predetermined value or more. It may be determined that not the liquid refrigerant but the gas refrigerant starts to flow, and the switching of the four-way valve 55 may be performed immediately.
[0055]
The inflow side check valves 45A and 45B and the outflow side check valves 46A and 46B may be replaced with inflow side on / off valves 70A and 70B and outflow side on / off valves 71A and 71B, respectively. In this case, the inflow side on / off valves 70A and 70B and 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 and cooling operation, the inflow side on / off valve 70A and the outflow side on / off valve 71B are opened / closed in conjunction with each other, and the inflow side on / off valve 70B and the outflow side on / off valve 71A are operated in conjunction with each other. The opening / closing operation is performed opposite to the opening / closing valve 71B. Furthermore, there may be three or more surge tanks 43A and 43B.
[0056]
【The invention's effect】
As described above, a plurality of tanks capable of storing refrigerant are arranged in parallel between the coil in the ice heat storage tank and the use side heat exchanger, and the liquid refrigerant condensed in the coil is stored in the tank. The high-pressure gas refrigerant stored in the tank and alternately supplied into the tanks can be pumped to the use-side heat exchanger, and the high-pressure gas refrigerant is alternately supplied into the tank. Since the liquid refrigerant is switched based on the temperature of the refrigerant flowing out of the tank, the liquid refrigerant is pumped from the other tank to the user side heat exchanger immediately when the liquid refrigerant in one tank is no longer present, immediately before or after it is no longer present. Therefore, the cooling operation using the cold heat of the ice in the ice heat storage tank can be carried out satisfactorily.
[Brief description of the drawings]
FIG. 1 is a pipe line diagram showing an embodiment of an air conditioner equipped with an ice heat storage tank according to the present invention.
FIG. 2 is a graph showing the relationship between the refrigerant temperature detected by the temperature sensor and the liquid level of the liquid refrigerant in the surge tank.
FIG. 3 is a pipe diagram showing an air conditioner equipped with a conventional ice heat storage tank.
[Explanation of symbols]
21 Heat source side unit 22 Ice heat storage unit 23 User side unit 28 Compressor 29 Four-way valve 32 User side heat exchanger 34 Coil 35 Ice heat storage tank 43A, 43B Surge tank 55 Four-way valve 56 Small capacity compressor 60 Controller 61 First temperature Sensor 62 Second temperature sensor 63 Third temperature sensor 64 Fourth temperature sensor

Claims (4)

A heat source side unit having a compressor and a heat source side heat exchanger, an ice heat storage unit in which a coil is placed 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 heat exchanger. In an air conditioner having an ice heat storage tank that can be used for ice making operation and cooling operation,
A plurality of tanks capable of storing refrigerant are arranged in parallel between the coil in the ice storage tank and the use side heat exchanger, and the liquid refrigerant condensed in the coil is stored in the tank. The high-pressure gas refrigerant alternately supplied into these tanks can be pumped to the use side heat exchanger,
An air conditioner equipped with an ice heat storage tank, wherein the alternating supply of the high-pressure gas refrigerant into the tank is switched based on the temperature of the refrigerant flowing out of the tank. In the alternate supply of the high-pressure gas refrigerant into the tank, the absolute value of the difference between the temperature of the refrigerant flowing out of the tank and the temperature of the high-pressure gas refrigerant supplied into the tank becomes equal to or lower than a predetermined temperature. The air conditioner having an ice heat storage tank according to claim 1, wherein the air conditioner is configured to be switched at a time. The alternating supply of the high-pressure gas refrigerant into the tank is configured to be switched when the 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 1. The high-pressure gas refrigerant supplied alternately to the plurality of tanks is a high-pressure gas refrigerant supplied from a small-capacity compressor having a capacity smaller than that of the compressor of the heat source side unit. An air conditioner comprising the ice heat storage tank according to any one of the above.

Images