JP2003287311A - Air-conditioner, and air-conditioner control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of the defrosting operation, to shorten the period of the defrosting operation, and to suppress generation of refrigerant noise. <P>SOLUTION: In an air-conditioner to perform the reverse cycle defrosting operation to allow the refrigerant discharged from a compressor in an outdoor heat exchanger by the cycle reverse to the heating operation cycle, the difference between the input temperature and the output temperature of the refrigerant in the indoor heat exchanger is detected, and the opening of an indoor electric-driven expansion valve is controlled based on the detected difference between the input temperature and the output temperature. In addition, when performing the reverse cycle defrosting operation with the heat accumulated in a heat accumulation tank as a heat source in an air-conditioner having a heat accumulation unit to perform the reverse cycle defrosting operation, the difference between the input temperature and the output temperature of the refrigerant is detected in a heat accumulation heat exchanger, and the opening of the heat accumulation electric-driven expansion valve is controlled based on the detected difference between the input temperature and the output temperature. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage type air conditioner for storing heat energy by ice or hot water and utilizing the stored heat energy for heating and cooling operation, and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, as an air conditioner, an outdoor unit containing a compressor, an outdoor heat exchanger, an accumulator, etc., a heat storage unit containing a heat storage coil in a heat storage tank, and an indoor heat exchanger have been housed. A heat storage type air conditioner in which an indoor unit is connected by a refrigerant pipe is known.

In this heat storage type air conditioner, cold heat (ice) is stored in the heat storage tank by using the late-night power, which has a relatively low power charge.
Alternatively, warm heat (hot water) is stored, and heat (heat energy) in the heat storage tank is used during the daytime to perform cooling / heating operation or improve cooling / heating operation capacity.

In such a heat storage type air conditioner, during heating operation, the four-way valve is switched to a position opposite to that during normal heating operation, so that the refrigerant discharged from the compressor is reversed from the heating operation cycle. In some cycles, the defrosting operation is performed by flowing the heat through the outdoor heat exchanger.

The conventional defrosting operation will be described below.

During the heating operation, the compressor is driven, the four-way valve is switched to the heating position, the outdoor electric valve is controlled according to the heating load, and the indoor electric valve is fully opened. On the other hand, when the defrosting operation is required, the compressor is stopped for a predetermined time (for example, 1 minute) and the outdoor electric valve is fully closed. After the elapse of a predetermined time, the compressor is driven, and at the same time, the four-way valve is switched to the position opposite to the normal heating operation, the outdoor electric valve is fully opened, and the indoor electric valve is opened at a predetermined opening degree (for example, , About half open) and the defrosting operation is performed.

After completion of the defrosting operation, the compressor is stopped again for a predetermined time (for example, 1 minute), and both the outdoor electric valve and the indoor electric valve are controlled to be fully closed. After that, the compressor is driven, the four-way valve is switched to the position for normal heating operation, the outdoor electric valve is controlled according to the heating load, the indoor electric valve is controlled to fully open, and the original heating operation is restored. It was.

[0008]

In the conventional heat storage type air conditioner described above, the opening degree of the indoor motor-operated valve during the defrosting operation is set to a constant predetermined opening degree. There were cases where the defrosting time became long and refrigerant noise was generated from the indoor unit side.

That is, when the opening degree of the indoor electric valve is too narrow for the defrosting condition, there is a problem that the defrosting time becomes long. on the other hand,
When the opening degree of the indoor electric valve is too open for the defrosting condition, the refrigerant becomes a gas-liquid mixed state due to incomplete heat exchange, and on the indoor unit side, There has been a problem that a refrigerant noise is generated.

Therefore, an object of the present invention is to improve the efficiency of defrosting operation, shorten the defrosting operation period, and suppress the generation of refrigerant noise, and an air conditioner control method. To provide.

[0011]

In order to solve the above-mentioned problems, a compressor, an outdoor heat exchanger, an indoor electric expansion valve and an indoor heat exchanger are provided, and a four-way valve during heating operation is reverse to that during heating operation. Switching to the position, the refrigerant discharged from the compressor, an air conditioner that performs a reverse cycle defrosting operation in which the heating operation cycle is passed through the outdoor heat exchanger in the reverse cycle,
When performing the reverse cycle defrosting operation using air as a heat source, an indoor temperature difference detection unit that detects the input / output temperature difference of the refrigerant in the indoor heat exchanger, and the refrigerant of the indoor heat exchanger based on the input / output temperature difference. And an indoor valve opening degree control unit that controls the opening degree of the indoor electric expansion valve that adjusts the pressure.

According to the above construction, the indoor temperature difference detecting section is
When performing the reverse cycle defrosting operation using air as a heat source, the difference in input / output temperature of the refrigerant in the indoor heat exchanger is detected.

The indoor valve opening control section controls the opening of the indoor electric expansion valve based on the input / output temperature difference.

In this case, the indoor valve opening degree control unit controls the opening degree of the indoor electric expansion valve to increase when the input / output temperature difference is larger than a predetermined reference temperature, When the difference is less than or equal to a predetermined reference temperature, the opening degree of the indoor electric expansion valve may be controlled to be decreased.

Further, an outdoor unit having a compressor and an outdoor heat exchanger, a heat storage electric expansion valve, a heat storage unit having a heat storage tank and a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger are provided. During operation, the four-way valve is switched to the position opposite to that during heating operation, and the reverse cycle defrosting operation is performed in which the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger in a cycle opposite to the heating operation cycle. The air conditioner, when performing the reverse cycle defrosting operation using the heat stored in the heat storage tank as a heat source, an indoor temperature difference detection unit that detects the input / output temperature difference of the refrigerant in the heat storage heat exchanger, and And a heat storage valve opening control unit that controls the opening of the heat storage electric expansion valve based on the written output temperature difference.

According to the above configuration, the indoor temperature difference detecting section is
When performing the reverse cycle defrosting operation using the heat stored in the heat storage tank as a heat source, the input / output temperature difference of the refrigerant in the heat storage heat exchanger is detected.

The heat storage valve opening control unit controls the opening of the heat storage electric expansion valve based on the input / output temperature difference.

In this case, the heat storage valve opening control unit controls the heat storage electric expansion valve so as to increase the opening when the input / output temperature difference is larger than a predetermined reference temperature, When the difference is less than or equal to a predetermined reference temperature, the opening degree of the heat storage electric expansion valve may be controlled to be decreased.

Further, it has a compressor, an outdoor heat exchanger, an indoor electric expansion valve, and an indoor heat exchanger, and switches the four-way valve to a position opposite to that during the heating operation during the heating operation and discharges from the compressor. Refrigerant is a heating operation cycle, the control method of the air conditioner performing a reverse cycle defrosting operation to flow in the outdoor heat exchanger in a cycle opposite to the heating operation cycle, when performing the reverse cycle defrosting operation using air as a heat source, the indoor Indoor temperature difference detection process for detecting the input / output temperature difference of the refrigerant in the heat exchanger, and indoor for controlling the opening degree of the indoor electric expansion valve that adjusts the refrigerant pressure of the indoor heat exchanger based on the input / output temperature difference And a valve opening control process.

In this case, the indoor valve opening degree control step is a valve opening control step in which the opening degree of the indoor electric expansion valve is controlled to increase when the input / output temperature difference is larger than a predetermined reference temperature. And a valve closing control step of controlling the opening degree of the indoor electric expansion valve to be decreased when the input / output temperature difference is equal to or lower than a predetermined reference temperature.

An outdoor unit having a compressor and an outdoor heat exchanger, a heat storage electric expansion valve, a heat storage unit having a heat storage tank and a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger are provided. During operation, the four-way valve is switched to the position opposite to that during heating operation, and the reverse cycle defrosting operation is performed in which the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger in a cycle opposite to the heating operation cycle. The control method of the air conditioner, when performing the reverse cycle defrosting operation using the heat stored in the heat storage tank as a heat source, an indoor temperature difference detection process of detecting the input / output temperature difference of the refrigerant in the heat storage heat exchanger. And a heat storage valve opening degree control process for controlling the opening degree of the heat storage electric expansion valve for adjusting the refrigerant pressure of the heat storage heat exchanger based on the input / output temperature difference.

In this case, the heat storage valve opening control process is a valve opening control process for controlling the heat storage electric expansion valve to increase its opening when the input / output temperature difference is larger than a predetermined reference temperature. And a valve closing control step of controlling the opening degree of the heat storage electric expansion valve to decrease when the input / output temperature difference is equal to or lower than a predetermined reference temperature.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a refrigerant circuit of the air conditioner of this embodiment.

An outdoor heat exchanger 5 is connected to the compressor 1 via a four-way valve 3. A receiver tank 7 is connected to the outdoor heat exchanger 5 via an outdoor electric expansion valve (hereinafter, referred to as an outdoor electric valve) 6 whose valve opening can be adjusted linearly. The receiver tank 7 has a heat storage electric expansion valve (hereinafter referred to as a heat storage electric valve) 11, a subcool valve 13, a check valve 14, and a linear valve opening whose valve opening can be linearly adjusted via a pipe 9. An adjustable indoor electric expansion valve (hereinafter referred to as indoor electric valve) 15 is connected. Indoor motor operated valve 1
5 is connected to the indoor heat exchanger 19 of the indoor unit 17 via the pipe 20. The indoor heat exchanger 19 of the indoor unit 17 is connected to the four-way valve 3 via a pipe 20, and the four-way valve 3 is connected to the accumulator 21 and the compressor 1.

In this air conditioner, the subcool valve 13, the check valve 14, the indoor motor-operated valve 15 and the indoor unit 17 described above are used.
The conduit 22 is connected so as to bypass the
A heat storage coil 23 and a two-way valve 24 are connected to 2. The heat storage coil 23 is installed in the heat storage tank 25 in a submerged state.

The receiver tank 7 is connected to a pipe line 22 connecting the heat storage coil 23 and the two-way valve 24 via a pipe line 28 having a thaw valve 26 and a check valve 27. Further, the receiver tank 7 is connected to a pipe line 9 connecting the check valve 14 and the indoor electric valve 15 via a pipe line 30 having a liquid line valve 29. A liquid valve 31 and a capillary tube 3 are provided between the outdoor electric valve 6 and the receiver tank 7.
A line 32 with 2 is connected, which line 32 is connected to the suction of the compressor 21.

During the ice making operation, the four-way valve 3 is switched to the solid line position, and the refrigerant discharged from the compressor 1 is transferred to the four-way valve 3,
The outdoor heat exchanger 5 and the outdoor electric valve 6 flow in this order and enter the receiver tank 7. Further, the refrigerant flows from the receiver tank 7 into the heat storage coil 23 in the heat storage tank 25 via the pipe 9, the heat storage motor-operated valve 11, and the pipe 22. Then, the refrigerant evaporates in the heat storage coil 23 to make ice in the heat storage tank 25, and the two-way valve 2
4, the four-way valve 3, and the accumulator 21 are returned to the compressor 1.

During the normal cooling operation cycle, the four-way valve 3 is switched to the solid line position, and the refrigerant discharged from the compressor 1 flows to the receiver tank 7 in the order of the four-way valve 3, the outdoor heat exchanger 5 and the outdoor electric valve 6. enter. Subsequently, the refrigerant flows from the receiver tank 7 to the pipe line 30 and the liquid line valve 29. Further, it passes through the indoor motor-operated valve 15 and flows into the indoor heat exchanger 19 of the indoor unit 17, where it is evaporated and vaporized, and the pipeline 20, the four-way valve 3,
It is returned to the compressor 1 via the accumulator 21.

During the heat storage cooling operation cycle, the four-way valve 3 is switched to the solid line position, and the refrigerant discharged from the compressor 1 flows to the receiver tank 7 in the order of the four-way valve 3, the outdoor heat exchanger 5, and the outdoor electric valve 6. After entering, through the pipe 28, the thaw valve 26, and the check valve 27, the refrigerant flows into the heat storage coil 23 in the heat storage tank 25, and the refrigerant is supercooled by the ice in the heat storage tank 25.

On the other hand, a part of the refrigerant in the receiver tank 7 merges with the refrigerant passing through the pipe line 22 which is supercooled by the opening degree of the expansion valve 11 and reaches the subcool valve 13 and the check valve 14. . Further, through the indoor electric valve 15, the indoor unit 17
Flows into the indoor heat exchanger 19 of, where it evaporates and vaporizes,
It is returned to the compressor 1 via the pipe line 20, the four-way valve 3, and the accumulator 21.

During the heating operation cycle, the four-way valve 3 is switched to the broken line position, and the refrigerant discharged from the compressor 1 flows into the indoor heat exchanger 19 of the indoor unit 17 via the four-way valve 3. After being condensed in the indoor heat exchanger 19, the refrigerant enters the receiver tank 7 via the indoor electric valve 15 and the liquid line valve 29. Further, the refrigerant flows from the receiver tank 7 to the outdoor electric valve 6
Flow into the outdoor heat exchanger 5, where it is evaporated and vaporized, and then passes through the four-way valve 3 and the accumulator 21 to the compressor 1
Returned to.

Next, the general operation of the defrosting operation cycle will be described.

When frost formation on the outdoor heat exchanger 5 is detected during the heating operation cycle, the four-way valve 3 is in the reverse position (solid line position).
And the refrigerant discharged from the compressor 1 flows along a cycle (a normal cooling operation cycle or a heat storage cooling operation cycle) opposite to the heating operation cycle described above,
So-called hot gas flows into the outdoor heat exchanger 5, and the outdoor heat exchanger 5 is defrosted by performing a reverse cycle defrosting operation (air defrosting operation). Note that a hot water defrosting operation using hot water in the heat storage tank 25 is also possible. In this case, the refrigerant from the outdoor heat exchanger 5 enters the heat storage tank 25 through the expansion valve 11 and uses the hot water heat source. Then, it returns to the four-way valve 3, the accumulator 21, and the compressor 1 via the two-way valve 24.

Next, regarding the valve opening control during the defrosting operation, FIG.
Will be described with reference to.

When frost formation on the outdoor heat exchanger 5 is detected during the heating operation cycle, the controller 7 of the air conditioner.
Based on the output of the temperature sensor 53, 0 determines whether or not the hot water temperature in the heat storage tank 25 is equal to or higher than the hot water defrosting reference temperature Tw sufficient for performing hot water defrosting (step S1).

In the determination of step S1, the heat storage tank 25
When the hot water temperature inside is lower than the hot water defrosting reference temperature Tw sufficient to perform hot water defrosting (step S1; No),
Since it is considered that the outside temperature is higher than the warm water,
The air defrosting operation is started (step S2).

That is, the four-way valve 3 is switched to the position indicated by the solid line, and the refrigerant discharged from the compressor 1 flows in the order of the four-way valve 3, the outdoor heat exchanger 5, and the outdoor electric valve 6 to receive the receiver tank 7.
to go into. Subsequently, the refrigerant flows from the receiver tank 7 to the pipe 30,
It reaches the liquid line valve 29. Furthermore, via the indoor motor-operated valve 15,
It flows into the indoor heat exchanger 19 of the indoor unit 17, where it is evaporated and vaporized, and returned to the compressor 1 via the pipe 20, the four-way valve 3, and the accumulator 21. Then, it again flows into the four-way valve 3 and the outdoor heat exchanger 5 to start defrosting.

By the way, in the present embodiment, in the reverse cycle defrosting operation, the fan 19A of the indoor heat exchanger 19 is stopped and the fan 19A of the indoor heat exchanger 19 is operated in a slight wind. Either of the breeze defrosting operation is selectively performed (step S3). That is, when the defrosting operation is finished in a short time, the breeze defrosting operation is selected. However, in the breeze defrosting operation, the cold air is blown into the room to be conditioned, so that the indoor temperature decreases. If it is not desired to lower the indoor temperature, the windless defrosting operation is selected.

Next, the controller 70 controls the indoor electric valve 15
The opening of is set to the intermediate opening (step S4). Specifically, the fully closed state of the indoor motor-operated valve 15 is set to 0 pulse (the number of pulses of the valve driving step motor), and the fully opened state is set to 480 pulses, and is set to about 200 pulses.

Subsequently, the controller 70 controls the temperature sensor 4
1 and the output of the temperature sensor 42, the input / output temperature difference ΔT1 of the refrigerant in the indoor heat exchanger 19 is detected (step S5). That is, assuming that the temperature corresponding to the output of the temperature sensor 41 is T11 and the temperature corresponding to the output of the temperature sensor 42 is T12, the input / output temperature difference ΔT1 is ΔT1 = | T
11-T12 |

Next, the controller 70 controls the input / output temperature difference Δ.
It is determined whether or not T1 is higher than a reference temperature Tref11 determined by the capacity of the indoor heat exchanger 19, that is, whether or not the indoor electric valve 15 is excessively throttled (step S6).

In the determination in step S6, if the input / output temperature difference ΔT1 is higher than the reference temperature Tref11 determined by the capacity of the indoor heat exchanger 19, that is, if the indoor electric valve 15 is excessively throttled (step S6). ; Ye
s), the opening degree of the indoor motor-operated valve 15 is controlled to increase (step S7). In the case of the above example, control is performed so that the pulse number of the valve driving step motor becomes larger than the current pulse number, and the process proceeds to step S8.

In the determination of step S6, if the input / output temperature difference ΔT1 is equal to or lower than the reference temperature Tref11 determined by the capacity of the indoor heat exchanger 19, that is, if the indoor electric valve 15 is opened too much (step S6). ; N
o), the opening degree of the indoor motor-operated valve 15 is controlled to decrease (step S9). In the case of the above example, control is performed so that the pulse number of the valve driving step motor becomes smaller than the current pulse number, and the process proceeds to step S8.

Subsequently, the controller 70 controls the temperature sensor 6
Based on the output of No. 1, the refrigerant temperature T in the outdoor heat exchanger 5
It is determined whether OUT is equal to or higher than the defrosting end reference temperature TEND sufficient to determine that defrosting is completed (step S8).

If it is determined in step S8 that the refrigerant temperature TOUT in the outdoor heat exchanger 5 is lower than the defrosting termination reference temperature TEND, it is necessary to continue the defrosting operation, and thus the process proceeds to step S5 again. And step S5
The process of step S8 is repeated.

When it is determined in step S8 that the refrigerant temperature TOUT in the outdoor heat exchanger 5 is equal to or higher than the defrosting termination reference temperature TEND based on the output of the temperature sensor 61, the controller 70 terminates the defrosting operation. .

Then, the controller 70 keeps the four-way valve 3 in a state similar to the defrosting operation for a predetermined time (for example, 60 seconds).
Is maintained, the outdoor electric valve 6 is fully opened, and the indoor electric valve 15 is approximately half opened, and the operation of the compressor 1 is stopped.

After the elapse of a predetermined time, the outdoor electric valve 6 is fully opened, the indoor electric valve 15 is left in a half open state, and the four-way valve 3 is switched to the heating operation position (indicated by a wavy line in FIG. 1). After waiting for a predetermined time (for example, 10 seconds), the compressor 1 is activated and the original heating operation is restored.

On the other hand, when it is determined in step S1 that the hot water temperature in the heat storage tank 25 is equal to or higher than the hot water defrosting reference temperature Tw (step S1; Yes), the hot water defrosting operation (the indoor unit 17 is supplied with a refrigerant). A non-flow operation) is started (step S10).

That is, the four-way valve 3 is switched to the position indicated by the solid line, and the refrigerant discharged from the compressor 1 flows in the order of the four-way valve 3, the outdoor heat exchanger 5, and the outdoor electric valve 6 to receive the receiver tank 7.
to go into. Further, the refrigerant flows from the receiver tank 7 to the expansion valve 1
1, through the pipe line 22, flows into the heat storage coil 23 in the heat storage tank 25. This heat storage coil 23 acts as an evaporator to heat the refrigerant, and the refrigerant is supplied to the pipe 22, the two-way valve 24, and the pipe 2.
0, four-way valve 3 and accumulator 21 and then compressor 1
Returned to. Then, the refrigerant again flows into the four-way valve 3 and the outdoor heat exchanger 5 to start defrosting.

Next, the controller 70 selectively performs either the windless defrosting operation or the breeze defrosting operation (step S11).

Next, the controller 70 causes the heat storage motor-operated valve 11 to operate.
The opening is set to the intermediate opening as in the case of the indoor motor-operated valve 15 (step S12).

Subsequently, the controller 70 controls the temperature sensor 5
Based on the outputs of 1 and the temperature sensor 52, the input / output temperature difference ΔT2 of the refrigerant in the heat storage tank 25 is detected (step S13). That is, the temperature corresponding to the output of the temperature sensor 51 is T21, and the temperature corresponding to the output of the temperature sensor 52 is T21.
22, the input / output temperature difference ΔT1 is ΔT2 = | T21−
T22 |

Next, the controller 70 controls the input / output temperature difference Δ.
Whether T2 is higher than a reference temperature Tref21 determined by the capacity of the heat storage tank 25, that is, the heat storage motor-operated valve 11
It is determined whether the aperture is too narrow (step S1).
4).

In the determination of step S14, the input / output temperature difference ΔT2 is higher than the reference temperature Tref21 determined by the capacity of the heat storage tank 25, that is, the heat storage electrically operated valve 11
If the aperture is too narrow (step S14; Ye
s), the heat storage motor-operated valve 11 is controlled to increase the opening degree (step S15). In the case of the above example, control is performed so that the pulse number of the valve driving step motor becomes larger than the current pulse number, and the process proceeds to step S16.

In the determination of step S14, the input / output temperature difference ΔT1 is equal to or lower than the reference temperature Tref21 determined by the capacity of the heat storage tank 25, that is, the heat storage electrically operated valve 11
If is too open (step S14; No), the opening degree of the heat storage motor-operated valve 11 is controlled to be decreased (step S17). In the case of the above example, control is performed so that the pulse number of the valve driving step motor becomes smaller than the current pulse number, and the process proceeds to step S16.

Subsequently, the controller 70 controls the temperature sensor 6
Based on the output of No. 1, the refrigerant temperature T in the outdoor heat exchanger 5
It is determined whether OUT is equal to or higher than the defrosting termination reference temperature TEND sufficient to determine that defrosting is completed (step S1).
6).

In the determination in step S16, the refrigerant temperature TOUT in the outdoor heat exchanger 5 is determined to be the defrosting end reference temperature TEND.
If it is lower than the above, it is necessary to continue the defrosting operation, and therefore, the process proceeds to step S13 again, and step S1
The processing from 3 to step S16 is repeated.

When it is determined in step S16 that the refrigerant temperature TOUT in the outdoor heat exchanger 5 is equal to or higher than the defrosting termination reference temperature TEND based on the output of the temperature sensor 61,
The controller 70 ends the defrosting operation and returns to the original heating operation in the same procedure as described above.

As described above, according to the present embodiment, during the air defrosting operation, by keeping the opening degree of the indoor motor-operated valve 15 at the optimum opening degree, the indoor heat exchanger 19 is made more efficient. Can be operated in a high temperature state, the defrosting time can be shortened, and the generation of refrigerant noise from the indoor unit can be suppressed.

Similarly, during the hot water defrosting operation, by keeping the opening degree of the heat storage motor-operated valve 11 at the optimum opening degree, the heat storage tank 25 can be operated in a state of higher thermal efficiency, and the outside air temperature can be maintained. In addition, since the defrosting capacity is not affected, the defrosting time can be shortened, and the refrigerant does not flow into the indoor unit, so that the generation of refrigerant noise from the indoor unit can be suppressed.

In the above description, an air conditioner having a heat storage tank has been described as an example, but the compressor has an outdoor heat exchanger, an indoor electric expansion valve, and an indoor heat exchanger, and a four-way valve is provided during heating operation. Is switched to the position opposite to the heating operation, the refrigerant discharged from the compressor is an air conditioner that performs a reverse cycle defrosting operation in which the refrigerant is discharged to the outdoor heat exchanger in the cycle opposite to the heating operation cycle. Indoor electrically operated valve that detects the input / output temperature difference of the refrigerant in the indoor heat exchanger when performing reverse cycle defrosting operation using air as the heat source and adjusts the refrigerant pressure in the indoor heat exchanger based on the detected input / output temperature difference. It suffices to control the opening degree of.

In this case, when controlling the opening degree of the indoor motor-operated valve, when the input / output temperature difference is larger than a predetermined reference temperature, the opening degree of the indoor motor-operated valve is controlled so as to increase. When the difference is less than or equal to the predetermined reference temperature, the opening degree of the indoor motor-operated valve may be controlled to be decreased.

[0065]

According to the present invention, the efficiency of defrosting operation can be improved, the defrosting time can be shortened, and the generation of refrigerant noise due to the flow of gas-liquid mixed refrigerant to the indoor unit side can be suppressed. You can

[Brief description of drawings]

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

FIG. 2 is a processing flowchart during a reverse cycle defrosting operation.

[Explanation of symbols]

1 compressor 3 four-way valve 5 outdoor heat exchanger 6 Outdoor electric expansion valve (outdoor electric valve) 11 Heat storage electric expansion valve (heat storage electric valve) 15 Indoor electric expansion valve (indoor electric valve) 19 Indoor heat exchanger 25 heat storage tank 41, 42, 51, 52, 61 Temperature sensor 70 controller

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F24F 11/02 F24F 11/02 101Z F25B 47/02 550 F25B 47/02 550F (72) Inventor Kazunori Ouchi Sanyo Denki Air Conditioning Co., Ltd., 1 Otsuki-cho, Ashikaga City, Tochigi Prefecture (72) Inventor Takao Shiina 1 Otsuki-cho, Ashikaga-shi, Tochigi Sanyo Denki Air Conditioning Co., Ltd. F-term (reference) 3L092 AA09 DA02 EA03 FA02 WA25

Claims (8)

[Claims] 1. A compressor, an outdoor heat exchanger, an indoor electric expansion valve, and an indoor heat exchanger are provided, and during heating operation, a four-way valve is switched to a position opposite to that during heating operation and discharged from the compressor. In the air conditioner that performs the reverse cycle defrosting operation in which the refrigerant that flows through the outdoor heat exchanger in a cycle opposite to the heating operation cycle, the indoor heat exchanger is used when performing the reverse cycle defrosting operation using air as a heat source. And an indoor valve opening control section that controls the opening degree of the indoor electric expansion valve based on the input / output temperature difference. Air conditioner. 2. The air conditioner according to claim 1, wherein the indoor valve opening control section increases the opening of the indoor electric expansion valve when the input / output temperature difference is larger than a predetermined reference temperature. The air conditioner is controlled so that the opening degree of the indoor electric expansion valve is reduced when the input / output temperature difference is equal to or lower than a predetermined reference temperature. 3. An outdoor unit having a compressor and an outdoor heat exchanger, a heat storage electric expansion valve, a heat storage unit having a heat storage tank and a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger, and heating. During operation, the four-way valve is switched to the position opposite to that during heating operation, and the reverse cycle defrosting operation is performed in which the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger in a cycle opposite to the heating operation cycle. In the air conditioner, when performing the reverse cycle defrosting operation using the heat stored in the heat storage tank as a heat source, an indoor temperature difference detection unit that detects the input / output temperature difference of the refrigerant in the heat storage heat exchanger, and An air conditioner comprising: a heat storage valve opening control unit that controls the opening of the heat storage electric expansion valve based on a written output temperature difference. 4. The air conditioner according to claim 3, wherein the heat storage valve opening control section increases the opening degree of the heat storage electric expansion valve when the input / output temperature difference is larger than a predetermined reference temperature. The air conditioner is controlled so that the opening degree of the heat storage electric expansion valve is reduced when the input / output temperature difference is equal to or lower than a predetermined reference temperature. 5. A compressor, an outdoor heat exchanger, an indoor electric expansion valve, and an indoor heat exchanger are provided, and the four-way valve is switched to a position opposite to that during heating operation during heating operation and discharged from the compressor. In a method of controlling an air conditioner that performs a reverse cycle defrosting operation in which a refrigerant that flows through the outdoor heat exchanger in a cycle opposite to the heating operation cycle, in performing the reverse cycle defrosting operation using air as a heat source, An indoor temperature difference detection step of detecting an input / output temperature difference of the refrigerant in the heat exchanger; and an indoor valve opening degree control step of controlling an opening degree of the indoor electric expansion valve based on the input / output temperature difference. A method for controlling an air conditioner, comprising: 6. The method for controlling an air conditioner according to claim 5, wherein in the indoor valve opening control process, the opening of the indoor electric expansion valve is adjusted when the input / output temperature difference is larger than a predetermined reference temperature. A valve opening control step of controlling in a direction of increasing the temperature, and a valve closing control step of controlling in a direction of decreasing the opening degree of the indoor electric expansion valve when the input / output temperature difference is equal to or lower than a predetermined reference temperature. A method for controlling an air conditioner characterized by the above. 7. An outdoor unit having a compressor and an outdoor heat exchanger, a heat storage electric expansion valve, a heat storage unit having a heat storage tank and a heat storage heat exchanger, and an indoor unit having an indoor heat exchanger, and heating. During operation, the four-way valve is switched to the position opposite to that during heating operation, and the reverse cycle defrosting operation is performed in which the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger in a cycle opposite to the heating operation cycle. In the control method of an air conditioner, when performing the reverse cycle defrosting operation using the heat stored in the heat storage tank as a heat source, an indoor temperature difference detection process of detecting an input / output temperature difference of the refrigerant in the heat storage heat exchanger And a heat storage valve opening degree control process of controlling the opening degree of the heat storage electric expansion valve based on the input / output temperature difference, the control method of the air conditioner. 8. The method for controlling an air conditioner according to claim 7, wherein the heat storage valve opening control step adjusts the opening of the heat storage electric expansion valve when the input / output temperature difference is larger than a predetermined reference temperature. A valve opening control step of controlling in a direction of increasing the temperature, and a valve closing control step of controlling in a direction of decreasing the opening degree of the heat storage electric expansion valve when the input / output temperature difference is equal to or lower than a predetermined reference temperature. A method for controlling an air conditioner characterized by the above.