JP2000104977A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively stop an icemaking operation. SOLUTION: The air conditioner comprises a heat source side unit 11 having compressors 18A to 18C and a heat source side heat exchanger 21, an ice thermal storage unit 12 having a coil 35 arranged as submerged in water in an ice thermal storage tank 36, and a user side unit 13 having user side heat exchangers 24 to 26. A temperature sensor 61 for detecting a temperature in the tank 36 is provided. If the sensor 61 detects a temperature of a predetermined temperature or lower at the time of an icemaking operation, the icemaking operation is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an air conditioner provided with an ice heat storage unit.

[0002]

2. Description of the Related Art A heat source side unit having 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 a use side having a use side heat exchanger 2. Description of the Related Art There is known an air conditioner having an ice heat storage unit having a unit and capable of performing an ice making operation and a cooling operation.

In this type of air conditioner, in the ice making operation, the gas refrigerant from the compressor becomes a liquid refrigerant through a heat source side heat exchanger, and then flows through an expansion valve into a coil in an ice heat storage tank to evaporate. After the ice making operation is performed in the ice heat storage tank, the gas refrigerant is returned to the compressor. This ice making operation is performed at night, and the ice in the ice storage tank is used during the cooling operation in the daytime. That is, the refrigerant that has been guided from the compressor to the heat source side heat exchanger and has become a liquid refrigerant flows into the coil in the ice heat storage tank to be in a supercooled state, and the liquid refrigerant in the supercooled state is used in the use side heat exchanger. Thawing cooling operation is performed.

[0004]

Generally, the above ice making operation is stopped when the water level in the ice storage tank rises to a predetermined position. Figure 3 shows the detection of the water surface position
The float sensor 50 shown in FIG. The float sensor 50 has a shaft 52 fixed vertically to the water surface 51 in the ice heat storage tank, and a float that is loosely fitted to the shaft 52 and floats on the water surface 51 to move up and down along the shaft 52 as the water surface 51 moves up and down. 53 and an electrical contact (not shown) that closes when the float 53 rises to a predetermined position. When the ice making operation is started, ice is gradually formed on the outer periphery of the coil in the ice heat storage tank, and the water surface 51 rises with an increase in the amount of ice making.
Rises and reaches a predetermined position, the electrical contact is closed. This is input to the controller of the air conditioner to stop the ice making operation. The position where the float 53 closes the electrical contact is set according to the capacity of the ice heat storage tank, and an appropriate amount of ice is made in the ice heat storage tank.

In the air conditioner which detects the completion of the ice making operation by the float sensor 50, the float 53 does not follow the rise of the water surface due to the freezing of the surrounding water or the like and sinks below the water surface. There is a possibility that the operation is stopped and the completion of the ice making operation cannot be detected. Since the completion of the ice making operation is not detected if there is a malfunction of the float sensor 50 due to freezing of the float 53 or other causes, the air conditioner continues the ice making operation even after making an appropriate amount of ice in the ice heat storage tank. In the worst case, the ice storage tank will be damaged.

The present invention has been made in consideration of the above circumstances, and has as its object to provide an air conditioner capable of reliably stopping an ice making operation.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a heat source side unit having a compressor and a heat source side heat exchanger, and a coil submerged in an ice heat storage tank. An air conditioner comprising an ice heat storage unit disposed therein and a use side unit having a use side heat exchanger, capable of performing an ice making operation for making ice in an ice heat storage tank and a cooling operation using ice. A temperature sensor for detecting a temperature in the ice heat storage tank, and stopping the ice making operation when the temperature sensor detects a temperature equal to or lower than a predetermined temperature during the ice making operation.

By disposing the temperature sensor in the ice storage tank at a predetermined distance from the ice surface at the time of completion of the ice making operation, the ice making can be performed based on the detection output of the temperature sensor even when the operation is not stopped after the ice making is completed. Operation is stopped.

[0009]

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

FIG. 1 is a circuit diagram showing an embodiment of the air conditioner of the present invention.

An air conditioner 10 shown in FIG. 1 has a heat source side unit 11, an ice heat storage unit 12, and a utilization side unit 13.
Is configured. Refrigerant piping 1 of heat source side unit 11
4 and a refrigerant pipe 3 arranged in parallel with the use side unit 13
Refrigerant pipes 15A and 15B connecting 0, 31 and 32
Are connected by refrigerant pipes 16 and 17 of the ice heat storage unit 12. The refrigerant pipe 15A is connected to the refrigerant pipe 16, and the refrigerant pipe 15B is connected to the refrigerant pipe 17.

In the heat source side unit 11, compressors 18A, 18B, and 18C are arranged in parallel in a refrigerant pipe 14, and an accumulator 19 is provided on a suction side of the compressors 18A, 18B and 18C, and a four-way valve 20 is provided on a discharge side. The heat source side heat exchanger 21, the electric expansion valve 22, and the receiver tank 23 are sequentially connected to the four-way valve 20 via the refrigerant pipe 14.

The use side unit 13 includes refrigerant pipes 30, 3
1 and 32, use-side heat exchangers 24, 25 and 26, respectively.
And electric expansion valves 27, 28, 29 are arranged near the use side heat exchangers 24, 25, 26 through which the liquid refrigerant flows in the refrigerant pipes 30, 31, 32.
The degree of opening of these electric expansion valves 27, 28, 29 is adjusted according to the air conditioning load.

The ice heat storage unit 12 includes an ice heat storage tank 36 accommodating a coil 35, and a receiver tank 37, an electric expansion valve 38, and a first electric open / close valve 41 are used in the refrigerant pipe 16 from the heat source side unit 11 side. Side unit 13
It is arranged sequentially toward. One end of a coil 35 is connected to the refrigerant pipe 16 between the electric expansion valve 38 and the first electric opening / closing valve 41 via a connection pipe 39. Coil 3
5 is connected to the ice heat storage unit 12 via a connection pipe 40.
The second electric open / close valve 42 is disposed in the connection pipe 40. Further, in the refrigerant pipe 16,
One end of a connection pipe 44 having a third electric on-off valve 43 is connected between the receiver tank 37 and the electric expansion valve 38. The other end of the connection pipe 44 is connected between the second electric on-off valve 42 and the coil 35 in the connection pipe 40.

The ice heat storage tank 36 is filled with water, the coil 35 is disposed in a submerged state, and a float sensor 50 for detecting a water surface position and the same inside the ice heat storage tank 36 as shown in FIG. Is provided with a temperature sensor 61 for detecting the temperature. During the ice making operation of the air conditioner 10, the coil 3
The liquid refrigerant from the heat source side heat exchanger 21 flows into the inside 5 and evaporates, thereby adhering to the outer periphery of the refrigerant pipe 30 and forming ice. As shown in FIG. 2, the temperature sensor 61 is attached at a position separated from the ice surface 60 formed on the outer periphery of the coil 35 after the ice making operation is completed. Therefore, the temperature sensor 61 normally detects the water temperature in the ice heat storage tank 36.

During the thawing / cooling operation of the air conditioner 10, the liquid refrigerant from the heat source side heat exchanger 21 flows into the coil 35 in a full state, and the liquid refrigerant melts the ice adhered to the outer periphery of the coil 35. By doing so, a supercooled state occurs.

The operation of the air conditioner 10 configured as described above is controlled by a controller including a microcomputer (not shown) based on input signals from various sensors and the like.

Next, the ice making operation and the ice melting / cooling operation of the air conditioner 10 will be described.

The ice making operation of the air conditioner 10 shown in FIG.
For example, the liquid refrigerant from the heat source side heat exchanger 21 in the heat source side unit 11 is supplied to the coil 35 in the ice heat storage tank 36 in the ice heat storage unit 12 during a time period when the electricity rate is low from 10 am to 8 am the following morning. Then, the operation for making ice in the ice heat storage tank 36 is performed. In the same drawing, the direction in which the refrigerant flows during the ice making operation is indicated by solid arrows.

In the ice heat storage unit 12, the first electric open / close valve 41 and the third electric open / close valve 43 are closed, and the electric expansion valve 38 and the second electric open / close valve 42 are opened. Further, the electric expansion valves 27, 28 and 2 of the use side unit 13
9 closes the valve.

In this state, when the compressors 18A, 18B, 18C of the heat source side unit 11 are started, the gas refrigerant discharged from these compressors 18A, 18B, 18C is:
It is condensed in the heat source side heat exchanger 21, decompressed through the electric expansion valve 22 and the electric expansion valve 38 of the ice heat storage unit 12, and flows into the coil 35 in the ice heat storage tank 36. The refrigerant that has flowed into the coil 35 evaporates to form ice on the outer periphery of the coil 35. Thereafter, the gas refrigerant in the coil 35 reaches the four-way valve 20 via the connection pipe 40, the second electric opening / closing valve 42 and the refrigerant pipe 17, and is returned to the compressors 18A, 18B, 18C via the accumulator 19.

In the ice making operation, when ice is formed on the outer periphery of the coil 35 and the outer surface 60 of the ice is made up to the position shown by the dashed line in FIG. 2, the float sensor 50 stops as the water level of the ice heat storage tank 36 rises. Outputs a signal and stops.

In the above ice making operation, the float sensor 5
If the stop signal is not output even after the completion of ice making due to malfunction of 0, the surface of the ice moves in a direction away from the coil 35 from the position shown by the dashed line in FIG. Then, when the ice surface reaches the position where the temperature sensor 61 is provided, the temperature sensor 61 comes to be located in the ice, and when the ice around the temperature sensor 61 is in a supercooled state, the temperature sensor 61 is turned to 0 ° C. Detect low temperature. When the temperature sensor 61 detects a temperature equal to or lower than a predetermined temperature (for example, −3 ° C.) in this state, the ice making operation is stopped.

In this way, even if the float sensor 50 malfunctions, the ice making operation can be reliably stopped.

As described above, the ice formed in the ice heat storage tank 36 is used in the ice melting and cooling operation during the daytime when the temperature rises. The thaw cooling operation is performed by the heat source side unit 11.
Is supplied to the coil 35 in the ice heat storage tank 36 in the ice heat storage unit 12 to make the liquid refrigerant from the heat source side heat exchanger 21 in a supercooled state. The heat is supplied to the heat exchangers 24, 25, and 26, and is carried out. In FIG. 1, the direction in which the refrigerant flows during the deicing / cooling operation is indicated by broken arrows.

In this case, in the ice heat storage unit 12, the second electric open / close valve 42 is closed and the first electric open / close valve 4 is closed.
The first and third electric on-off valves 43 are opened, and the electric expansion valve 38 is opened.
Is closed. Further, the electric expansion valves 27, 28 and 29 of the use side unit 13 are opened.

In this state, when the compressors 18A, 18B, 18C of the heat source side unit 11 are started, the gas refrigerant discharged from these compressors 18A, 18B, 18C is:
The coil 3 is condensed in the heat source side heat exchanger 21, passes through the electric expansion valve 22, the refrigerant pipe 16 of the ice heat storage unit 12, the connection pipe 44, and the third electric open / close valve 43, and is stored in the ice heat storage tank 36.
Flow into 5. The liquid refrigerant flowing into the coil 35 is
It flows in the coil 35 in a full state, defrosts the ice adhering to the outer periphery of the coil 35, and is brought into a supercooled state by the cold stored in the ice. Thereafter, the supercooled liquid refrigerant in the coil 35 is used through the connection pipe 39, the first electric opening / closing valve 41 and the refrigerant pipe 16, the refrigerant pipe 15 </ b> A of the use side unit 13 and the electric expansion valves 27, 28, 29. Side heat exchanger 2
4, 25, and 26, respectively, and evaporates by each of these use-side heat exchangers 24, 25, and 26 to cool the room. Thereafter, the gas refrigerant is supplied to the refrigerant pipes 30, 31,
32, the refrigerant pipe 15B, the refrigerant pipe 17 of the ice heat storage unit 12, the four-way valve 20 and the accumulator 1
After passing through 9, it is returned to the compressors 18A, 18B, 18C.

When the temperature sensor 61 detects a temperature equal to or higher than the temperature at which efficient cooling operation is performed by utilizing the cooling heat in the ice heat storage tank 36 (for example, 20 ° C.), the electric opening / closing valve is operated. 42 and 43 are closed, and the electric expansion valve 38 and the electric open / close valve 41 are opened to switch to a normal cooling operation that does not use the cold heat in the ice heat storage tank 36. Thus, the temperature sensor 61 is used for preventing excessive ice making during the ice making operation and for stopping the ice melting and cooling operation.

In the above embodiment, the completion of ice making during the ice making operation is detected by the float sensor 50. However, the float sensor 50 is omitted, and the ice making is completed based on the temperature detected by the temperature sensor 61. May be detected to stop the ice making operation. In this case, the temperature sensor 61 is disposed closer to the coil 35 than the position shown in FIG.
When a lower predetermined temperature is detected, the ice making operation is stopped.
According to this, a float sensor is not required, and cost reduction and control processing can be simplified.

[0030]

As described above, according to the present invention, the completion of ice making during the ice making operation can be reliably detected and the operation can be stopped, thereby preventing the ice from being excessively made in the ice heat storage tank. .

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of an air conditioner of the present invention.

FIG. 2 is an enlarged view of a main part of the ice heat storage tank of the present invention.

FIG. 3 is a diagram showing a float sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Air conditioner 11 Heat source side unit 12 Ice heat storage unit 13 User side unit 21 Heat source side heat exchanger 24 User side heat exchanger 25 User side heat exchanger 26 User side heat exchanger 35 Coil 36 Ice heat storage tank 61 Temperature sensor

Claims (2)

[Claims] 1. A heat source side unit having 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 a use side having a use side heat exchanger. An air conditioner comprising a unit and an ice making operation for making ice in the ice heat storage tank, and a cooling operation using the ice, wherein a temperature sensor for detecting a temperature in the ice heat storage tank is provided; An air conditioner, wherein the ice making operation is stopped when the temperature sensor detects a temperature equal to or lower than a predetermined temperature during operation. 2. The air conditioner according to claim 1, wherein the temperature sensor is disposed in the ice heat storage tank at a predetermined distance from an ice surface when the ice making operation is completed.