JPH08189686A - Air conditioner - Google Patents

Abstract

PURPOSE: To provide an air conditioner in which the transmission of a heterogeneous sound into a room at the time of defrosting can be prevented. CONSTITUTION: When an outdoor heat exchanger is frozen during heating or the exchanger is frozen at the time of starting the heating, a defrosting operation for circulating refrigerant in reverse direction to that of the original heating between an indoor unit 1 and an outdoor unit. Flaps 7A, 7B provided at the air outlet 6 of the unit 1 are closed by flap control means while the defrosting is conducted, and at the time of transferring to the original heating, the flaps 7A, 7B are opened. After the freezing of the exchange is released, it is transferred to the original heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner.
More specifically, the present invention relates to an air conditioner that performs a defrosting operation by circulating a refrigerant between an indoor unit and an outdoor unit in a direction opposite to the original heating operation.

[0002]

2. Description of the Related Art In an air conditioner of this type, an outdoor unit 20 and an indoor unit 1 are connected to refrigerant pipes 11, 12 as shown in FIG.
Are connected with. The outdoor unit 20 includes an outdoor heat exchanger 22.
, A compressor 23, and an accumulator 24 for separating gas and liquid
And a four-way switching valve 25 for switching the direction of the refrigerant. Generally, when the outdoor heat exchanger freezes (frost) during heating operation, defrosting operation (defrosting) is performed to defrost the outdoor heat exchanger, and then control to shift to the original heating operation is performed. To do.

During the heating operation, the compressor 23 and the outdoor fan are operated, and the compressor 23 is set by the switching setting of the four-way switching valve 25 as shown by the broken line in FIG.
The refrigerant discharged by the four-way switching valve 25, the pipe 11
To the indoor heat exchanger 2, and is returned from the indoor heat exchanger 2 to the compressor 23 through the pipe 12, the outdoor heat exchanger 22, the four-way switching valve 25, and the accumulator 24. Indoor unit 1
On the (see FIG. 1) side, the indoor fan 3 is operated, and the flaps 7A and 7B of the air outlet 6 are opened and directed downward. As a result, the heat taken in by the outdoor heat exchanger 22 is carried to the indoor heat exchanger 2 by the refrigerant, and is discharged indoors through the air outlet 6 by the air blown by the indoor fan 3.

When the outdoor heat exchanger 22 is frozen, the defrosting operation is started. That is, the outdoor fan and the indoor fan are stopped, and the four-way switching valve 25 is switched to circulate the refrigerant in the direction indicated by the solid line (the same direction as in the cooling operation). That is, the refrigerant discharged by the compressor 23 is sent to the indoor heat exchanger 2 through the four-way switching valve 25, the outdoor heat exchanger 22, and the pipe 12, and the indoor heat exchanger 2 pipes 11, the four-way switching valve 25, It returns to the compressor 23 through the accumulator 24. Thereby, the outdoor heat exchanger 22 is heated by the heat carried by the refrigerant from the indoor side. conventionally,
While performing the defrosting operation, the flaps 7A and 7B of the air outlet 6 of the indoor unit 1 (see FIG. 1) are opened and directed downward in the original heating operation state.

When the freezing of the outdoor heat exchanger 22 is released, the defrosting operation is terminated and the original heating operation is started.

[0006]

However, in the above conventional air conditioner, during the defrosting operation, the refrigerant flows in the indoor unit 1 with the indoor fan stopped, and the air outlet is open. There is a problem that a different sound (sound of refrigerant flowing) from the original operation sound during the heating operation (mainly the sound of the indoor fan) is transmitted to the room, causing the user to feel discomfort.

Therefore, an object of the present invention is to provide an air conditioner capable of preventing the transmission of foreign noise into the room during the defrosting operation.

[0008]

In order to achieve the above object, the air conditioner according to claim 1 has an outdoor heat exchanger when the outdoor heat exchanger is frozen during heating operation or at the time of starting heating operation. When it is frozen, defrosting operation is performed between the indoor unit and the outdoor unit to circulate the refrigerant in the opposite direction to the original heating operation to release the freezing of the outdoor heat exchanger, and then the original heating operation. In the air conditioner that shifts to, while the defrosting operation is performed, the flap provided at the outlet of the indoor unit is closed, and a flap control means that opens the flap at the time of shifting to the original heating operation is provided. Is characterized by.

The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, in which a fan provided in the indoor unit for sucking in indoor air and blowing it out from the air outlet is provided. It is characterized in that it has a fan control means that is operated during the defrosting operation.

[0010]

In the air conditioner according to the present invention, the flap provided at the air outlet of the indoor unit is closed by the flap control means during the defrosting operation, so that the sound of the refrigerant flowing inside the indoor unit (the foreign sound) is generated. Hard to reach. Therefore, the discomfort of the user is reduced. Since the flap is opened by the flap control means at the time of shifting to the original heating operation, the original heating operation is not hindered.

In the air conditioner of the second aspect, the fan provided in the indoor unit for sucking the indoor air and blowing it out from the outlet is further operated by the fan control means during the defrosting operation. The sound of the refrigerant flowing is masked by the normal operating sound of the fan. Therefore, the user does not feel any foreign sound and feels no discomfort.

[0012]

EXAMPLES The air conditioner of the present invention will be described in detail below with reference to examples.

The air conditioner to which the present invention is applied is similar to the air conditioner shown in FIG. 3, in which the outdoor unit 20 and the indoor unit 1 are connected by refrigerant pipes 11 and 12. Outdoor unit 20
An outdoor heat exchanger 22, a compressor 23, an accumulator 24 for separating gas and liquid, and a four-way switching valve 25 for switching the direction of the refrigerant are provided in the. On the other hand, indoor unit 1
As shown in FIG. 1, the indoor heat exchanger 2 and the fan 3 are
Is provided. By operating the fan 3, the air in the room can be sucked in through the suction louver 4, and the sucked air can be blown out into the room through the indoor heat exchanger 2, the fan 3, the air flow path 5, and the air outlet 6. The blowout flap 6 is provided with blowout flaps 7A and 7B which are rotatable around shafts 8A and 8B. This blow flap 7
A and 7B are designed to be automatically opened and closed according to the operation mode under the control of a central processing unit (CPU) (not shown). The CPU functions as a flap control unit and a fan control unit. Generally, the blow-out flaps 7A and 7B are directed upward (approximately horizontal direction) during cooling operation in order to improve the efficiency of air conditioning.
It is designed to be directed downward (substantially vertically) during heating operation.

This air conditioner is controlled by the CPU according to the flow shown in FIG.

First, when the heating operation is switched on,
The compressor 1 and the outdoor fan are operated (S1). At the same time, by setting the switching of the four-way switching valve 25, the refrigerant discharged by the compressor 23 is sent to the indoor heat exchanger 2 through the four-way switching valve 25 and the pipe 11 as shown by the broken line in FIG. The indoor heat exchanger 2 is returned to the compressor 23 through the pipe 12, the outdoor heat exchanger 22, the four-way switching valve 25, and the accumulator 24 (S1). Indoor unit 1 (see Figure 1)
On the side, in order to prevent the cool air from suddenly blowing toward the person in the room, the indoor fan 3 is once operated at a low level (LL) (S2), and the flap 7 of the air outlet 6 is provided.
Open A and 7B and turn them upward (S3). CPU above
Monitors the temperature of the indoor heat exchanger 2 by a temperature sensor (not shown) attached to the indoor heat exchanger 2 and keeps this state (S2, S) until the temperature becomes a certain value or more (S4).
Continue 3). Then, when the temperature of the indoor heat exchanger 2 exceeds a certain value (S4), the operation level of the indoor fan 3 is adjusted with reference to the indoor designation tap that designates the operation mode (S5), and the flaps 7A and 7B are also adjusted. At the specified position,
Since it is in the heating operation here, it is turned downward (S6).
As a result, the original heating operation is performed.

When the outdoor heat exchanger 22 freezes, the defrosting operation is started (S7). That is, the CPU monitors the temperature of the outdoor heat exchanger 22 by a temperature sensor (not shown) attached to the outdoor heat exchanger 22, and determines that the outdoor heat exchanger 22 has frozen when the temperature becomes a certain value or less. To do. Then, the outdoor fan and the indoor fan are stopped, and the four-way switching valve 25 shown in FIG. 3 is switched to circulate the refrigerant in the direction indicated by the solid line (the same direction as during the cooling operation). That is, the refrigerant discharged from the compressor 23 is sent to the indoor heat exchanger 2 through the four-way switching valve 25 and the accumulator 24 through the outdoor heat exchanger 22 and the pipe 12, and the indoor heat exchanger 2 is connected to the pipe 11 and the four-way switching. Return to compressor 23 through valve 25. Thereby, the outdoor heat exchanger 22 is heated by the heat carried by the refrigerant from the indoor side. At the same time when the defrosting operation is entered, the flaps 7A and 7B provided on the air outlet 6 of the indoor unit 1 are closed (S8). And
This state (S8) is maintained until the freezing of the outdoor heat exchanger 22 is released and the defrosting operation ends (S9). As described above, since the flaps 7A and 7B are controlled to be closed during the defrosting operation, the sound of the refrigerant flowing inside the indoor unit 1 (heterogeneous sound) is less likely to be transmitted to the room. Therefore, the discomfort of the user can be reduced.

When the temperature of the outdoor heat exchanger 22 rises and exceeds a certain value, the CPU determines that the defrosting operation has ended. Then, the operation proceeds to the original heating operation (S1
0). At this time, the flaps 7A and 7B provided at the air outlet 6 of the indoor unit 1 are opened and directed downward. Therefore,
It does not interfere with the original heating operation.

Although the indoor fan 3 is stopped during the defrosting operation in the above example, the indoor fan 3 may be operated during the defrosting operation as shown in FIG. 2 (b). That is, at the same time when the defrosting operation is entered, the air outlet 6 of the indoor unit 1
The flaps 7A and 7B provided in the above are closed (S18), and the indoor fan 3 is operated at a low level (S19).
Then, until the outdoor heat exchanger 22 is defrosted and the defrosting operation is completed (S20), this state (S18, S1)
Continue 9). In this way, since the indoor fan 3 is further operated during the defrosting operation, the sound of the refrigerant flowing is masked by the operation sound of the fan. Therefore, the user does not feel any foreign sound, and the discomfort of the user can be eliminated.

Further, in this embodiment, the case where the outdoor heat exchanger 22 is frozen during the heating operation has been described. However, the present invention also relates to the case where the outdoor heat exchanger 22 is frozen at the start of the heating operation. It can be applied similarly.

[0020]

As is clear from the above, the air conditioner according to the first aspect of the present invention controls the flap provided at the outlet of the indoor unit by the flap control means during the defrosting operation. The sound of the refrigerant flowing inside the machine (heterogeneous sound) is less likely to be transmitted to the room. Therefore, the discomfort of the user can be reduced.

In the air conditioner of the second aspect, since the fan provided in the indoor unit for sucking in the indoor air and blowing it out from the outlet is further operated by the fan control means during the defrosting operation, The sound of the refrigerant flowing is masked by the operating sound of the fan. Therefore, the user does not feel any foreign sound, and the discomfort of the user can be eliminated.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of an indoor unit of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a diagram showing a control flow of the air conditioner of one embodiment of the present invention.

FIG. 3 is a diagram showing a schematic configuration of an air conditioner.

[Explanation of symbols]

 1 Indoor unit 2 Indoor heat exchanger 3 Indoor fan 6 Outlet 7A, 7B Outlet flap 20 Outdoor unit

Claims (2)

[Claims] 1. The original heating operation between the indoor unit (1) and the outdoor unit when the outdoor heat exchanger is frozen during the heating operation or when the outdoor heat exchanger is frozen at the start of the heating operation. In the air conditioner that performs the defrosting operation in which the refrigerant is circulated in the opposite direction to cancel the freezing of the outdoor heat exchanger, and then shifts to the original heating operation, while performing the defrosting operation, the indoor unit The flaps (7A, 7B) provided at the air outlet (6) of (1) are closed, and the flap (7
An air conditioner having a flap control means for opening A, 7B). 2. The air conditioner according to claim 1, further comprising a fan (3) provided in the indoor unit (1) for sucking indoor air and blowing the air out of the air outlet (6). An air conditioner having a fan control unit that operates during the defrosting operation.