JPH10205932A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of performing the defrosting operation while keeping the heating operation. SOLUTION: An air conditioner comprises a compressor 1, an indoor side heat exchanger 5, a pressure reducing device 7, and an outdoor side heat exchanger 9 which are successively connected to each other through a refrigerant pipe. A heat exchanger 11 for defrosting is provided on the upstream side of the outdoor side heat exchanger 9, a change-over valve 13 is provided between the indoor side heat exchanger 5 and the pressure reducing device 7, and the refrigerant can be fed to the indoor side heat exchanger 5, the heat exchanger 11 for defrosting, the pressure reducing device 7, and the outdoor side heat exchanger 9 in this order by switching the change-over valve 13 to the defrosting position during the defrosting operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of performing a defrosting operation while maintaining a heating operation in winter, for example.

[0002]

2. Description of the Related Art In general, there is known an air conditioner in which a compressor, an indoor heat exchanger, a decompression device, and an outdoor heat exchanger are sequentially connected by refrigerant piping. In this type of air conditioner, there is a problem in that if the frost is formed on the outdoor heat exchanger during the heating operation at a low outside air temperature, the capacity during the heating operation is reduced. In order to solve this, conventionally, in the case where the operation switching between the cooling and heating is possible, by temporarily switching from the heating operation to the cooling operation cycle by switching the four-way valve, the high temperature of the outdoor heat exchanger is transferred to the outdoor heat exchanger. Defrosting is performed by supplying a refrigerant, or hot gas from a compressor is directly supplied to an outdoor heat exchanger to perform defrosting.

[0003]

However, in the case of temporarily switching from the heating operation to the cooling operation cycle, the heating operation cannot be continued during the defrosting operation even though it is temporary. There is. In the case of directly supplying hot gas from the compressor to the outdoor heat exchanger, there is a problem that the entire energy efficiency is reduced by the amount of the hot gas returned to the outdoor heat exchanger.

[0004] Therefore, an object of the present invention is to provide an air conditioner capable of performing a defrosting operation while continuing a heating operation.

[0005]

According to the first aspect of the present invention, there is provided an air conditioner in which a compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger are sequentially connected by refrigerant piping. A heat exchanger for defrosting is provided on the windward side of the heat exchanger, and a switching valve is provided between the indoor heat exchanger and the pressure reducing device. During the defrosting operation, the switching valve is switched to a defrosting operation position. Thereby, the refrigerant can be supplied in the order of the indoor heat exchanger, the defrosting heat exchanger, the pressure reducing device, and the outdoor heat exchanger.

According to a second aspect of the present invention, in an air conditioner in which a compressor, an indoor heat exchanger, a decompression device, and an outdoor heat exchanger are connected in order by a refrigerant pipe, the windward of the outdoor heat exchanger is provided. A defrosting heat exchanger, and a switching valve between the indoor heat exchanger and the decompression device. During defrosting operation, the switching valve is switched to a defrosting operation position so that indoor heat exchange is performed. The defrosting heat exchanger is bypassed by switching the switching valve to the heating operation position during normal heating operation by enabling the supply of refrigerant in the order of the heat exchanger, the defrosting heat exchanger, the pressure reducing device, and the outdoor heat exchanger. Thus, the refrigerant can be supplied in the order of the indoor heat exchanger, the decompression device, and the outdoor heat exchanger, and excess refrigerant can be stored in the defrosting heat exchanger. .

According to a third aspect of the present invention, in the first or second aspect, the switching valve comprises a four-way valve.

According to a fourth aspect of the present invention, in the first aspect, the defrosting heat exchanger and the outdoor heat exchanger are integrally formed. It is characterized by the following.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, this air conditioner includes a compressor 1, a four-way valve (hereinafter, referred to as a "first four-way valve") 3, an indoor heat exchanger 5, a pressure reducing device 7, And an outer heat exchanger 9. A defrosting heat exchanger 11 is provided on the windward side of the outdoor heat exchanger 9, and a switching valve (hereinafter, referred to as a "second four-way valve") 13) are provided. The defrosting heat exchanger 11 is connected to the second four-way valve 13, and these constitute a closed loop 15 when the second four-way valve 13 is switched to the position indicated by the solid line.

FIG. 2 shows a specific configuration of the outdoor heat exchanger 9, and the defrost heat exchanger 11 and the outdoor heat exchanger 9 are integrally formed. By being integrally formed, compactness is achieved and installation space is reduced.

Next, the operation will be described. During heating operation,
The first four-way valve 3 is switched to the position indicated by the solid line, and the second four-way valve 13 is switched to the position indicated by the solid line (“heating operation position”). Then, the refrigerant flows into the compressor 1, the first four-way valve 3, the indoor heat exchanger 5, the second four-way valve 13, the pressure reducing device 7, the outdoor heat exchanger 9, and the first Circulated in the order of the four-way valve 3 and returned to the compressor 1. According to this, heating operation is performed by the indoor side heat exchanger 5 functioning as a condenser.

When the outside air temperature decreases, the outdoor heat exchanger 9
When the outlet temperature of the air passing through the air becomes 0 ° C. or less, frost formation is predicted or frost formation occurs, so the operation is switched to the defrosting operation. In this case, the second four-way valve 13 is switched to the position indicated by the dotted line (“defrosting operation position”). Then the refrigerant
As shown by the dotted arrows, the compressor 1, the first four-way valve 3, the indoor heat exchanger 5, the second four-way valve 13, the defrosting heat exchanger 1
1, the second four-way valve 13, the pressure reducing device 7, the outdoor heat exchanger 9, and the first four-way valve 3 are circulated in this order and returned to the compressor 1. According to this, since the defrosting heat exchanger 11 functions as a condenser ("reheater"), the outdoor heat exchanger 9
Is heated by the air supplied to the
Frost formation on the outdoor heat exchanger 9 is prevented.

That is, the defrost heat exchanger 11 functions to raise the temperature of the outside air to a temperature (0 ° C.) at which frost formation on the outdoor heat exchanger 9 can be prevented. According to this embodiment, the defrosting operation can be performed while the heating operation is continued. If a compressor whose rotational frequency can be controlled by an inverter, for example, is used as the compressor 1, even if the outside air temperature is considerably reduced, the outside air temperature can be reduced to 0 while maintaining the necessary heating capacity.
Since the reheating can be performed up to the temperature of not less than ° C., it is possible to avoid such a disadvantage that the heating operation is temporarily stopped as in the conventional defrosting operation.

During the cooling operation, the first four-way valve 3 is switched to the position indicated by the dotted line, and the second four-way valve 13 is switched to the position indicated by the solid line ("cooling operation position"). Then, after the first four-way valve 3, the refrigerant flows in the direction opposite to the solid line arrow, and the outdoor heat exchanger 9, the pressure reducing device 7, and the second four-way valve 1
3, circulating in the order of the indoor heat exchanger 5 and the first four-way valve 3 and returned to the compressor 1. According to this, the indoor heat exchanger 5
Functions as an evaporator, thereby performing a cooling operation.

FIG. 3 shows another embodiment. In this air conditioner, a radiant panel is used for the indoor heat exchanger 5. The radiant panel 5 has a refrigerant pipe 21 arranged, for example, meandering inside the panel. In this type, since the internal volume of the refrigerant tube of the radiant panel 5 is significantly larger than the internal volume of the refrigerant tube of the outdoor heat exchanger 9, the optimal amount of refrigerant during the heating operation is smaller than that during the cooling operation. Remarkably many. In such an air conditioner, it is desirable to store excess refrigerant during cooling operation in, for example, a receiver tank (not shown). However, installation of the receiver tank is not preferable because it causes an increase in space and cost.

Therefore, according to this embodiment, the point A between the second four-way valve 13 and the defrosting heat exchanger 11,
And point B between the pressure reducing device 7 and the outdoor heat exchanger 9
Are connected by a pipe 23, and an electromagnetic valve 25 is connected to the pipe 23.

During the heating operation, the first four-way valve 3 is switched to the position indicated by the solid line, the second four-way valve 13 is switched to the position indicated by the solid line, and the solenoid valve 25 is opened. Then, the refrigerant is compressed by the compressor 1, the first four-way valve 3, the indoor heat exchanger 5, the second four-way valve 13, the pressure reducing device 7, the outdoor heat exchanger 9, and the first Circulating in the order of the four-way valve 3 is returned to the compressor 1. The indoor heat exchanger 5 functions as a condenser, and a heating operation is performed. In this case, the low-pressure side (“point B”) of the refrigerant circuit communicates with the closed loop 15 via the solenoid valve 25.
The refrigerant is stored in a gaseous state. To the extent that the refrigerant is stored in a gaseous state, the mass of the stored refrigerant is small, and most of the refrigerant circulates in the refrigerant circuit.

When the outside air temperature decreases, the outdoor heat exchanger 9
When the outlet temperature of the air passing through the air becomes 0 ° C. or lower, frost formation is predicted or frost formation occurs, and the operation is switched to the defrosting operation. In this case, the second four-way valve 13 is switched to the position indicated by the dotted line (“defrosting operation position”) and the electromagnetic valve 2
5 is closed.

Then, the refrigerant flows into the compressor 1, the first four-way valve 3, the indoor heat exchanger 5, the second four-way valve 13, the defrosting heat exchanger 11, and the second The four-way valve 13, the pressure reducing device 7, the outdoor heat exchanger 9, and the first four-way valve 3 circulate in this order and return to the compressor 1. According to this, since the air supplied to the outdoor heat exchanger 9 is heated by the defrosting heat exchanger 11 functioning as a condenser ("reheater"), the heat is applied to the room. Frost formation on the outer heat exchanger 9 is prevented.

That is, the defrost heat exchanger 11 functions to raise the temperature of the outside air to a temperature (0 ° C.) at which frost formation on the outdoor heat exchanger 9 can be prevented. According to this embodiment, the defrosting operation can be performed while the heating operation is continued.

During the cooling operation, the first four-way valve 3 is switched to the position indicated by the dotted line, the second four-way valve 13 is switched to the position indicated by the solid line ("cooling operation position"), and the solenoid valve 25 is opened. Then, after the first four-way valve 3, the refrigerant flows in the direction opposite to the solid line arrow, and the outdoor heat exchanger 9, the pressure reducing device 7, the second four-way valve 13, the indoor heat exchanger 5, Circulated in the order of the four-way valve 3 and returned to the compressor 1.

During the cooling operation, as described above, the refrigerant is excessive, and the surplus refrigerant is stored in the closed loop 15, so that the conventional receiver tank becomes unnecessary. In this case, the high pressure side ("point B") of the refrigerant circuit communicates with the closed loop 15 via the solenoid valve 25, so that the excess refrigerant flowing into the closed loop 15 is condensed and completely stored as liquid refrigerant. Is done. According to this, since the optimum amount of refrigerant circulates in the refrigerant circuit, efficient cooling operation is performed.

Although the present invention has been described based on an embodiment, it is apparent that the present invention is not limited to this. For example, the second four-way valve 13 is not limited to a four-way valve. That is, it is only necessary that the flow path can be switched.

[0024]

According to these inventions, during the defrosting operation, the switching valve is switched to the defrosting operation position, so that the indoor heat exchanger, the defrost heat exchanger, the pressure reducing device and the outdoor heat exchanger are arranged in this order. Since the refrigerant can be supplied, the air passing through the defrosting heat exchanger is heated, and the heated air is supplied to the outdoor heat exchanger, so that the defrosting operation is performed while the heating operation is continued. be able to.

In the normal heating operation, the switching valve is switched to the heating operation position to bypass the defrosting heat exchanger and supply the refrigerant in the order of the indoor heat exchanger, the pressure reducing device, and the outdoor heat exchanger. In addition, since the excess refrigerant can be stored in the defrosting heat exchanger, the indoor heat exchanger is, for example, a radiant panel, and the optimal refrigerant amount in the heating operation is significantly larger than that in the cooling operation. Even at the time, the excess refrigerant during the cooling operation can be stored without using a receiver tank or the like.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of an outdoor heat exchanger.

FIG. 3 is a circuit diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Four-way valve ("first four-way valve") 5 Indoor heat exchanger 7 Decompression device 9 Outdoor heat exchanger 11 Defrosting heat exchanger 13 Switching valve ("Second four-way valve") 15 Closed loop

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor's Agency Masayuki 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (4)

[Claims] 1. An air conditioner in which a compressor, an indoor heat exchanger, a decompression device, and an outdoor heat exchanger are connected in order by a refrigerant pipe, wherein a heat exchanger for defrosting is provided upstream of the outdoor heat exchanger. And a switching valve is provided between the indoor heat exchanger and the decompression device. During the defrosting operation, the switching valve is switched to a defrosting operation position, so that the indoor heat exchanger and the heat exchange for defrosting are provided. An air conditioner characterized in that a refrigerant can be supplied in the order of a vessel, a decompression device, and an outdoor heat exchanger. 2. An air conditioner in which a compressor, an indoor heat exchanger, a decompression device, and an outdoor heat exchanger are connected in order by a refrigerant pipe, wherein a heat exchanger for defrosting is located upstream of the outdoor heat exchanger. And a switching valve is provided between the indoor heat exchanger and the decompression device. During the defrosting operation, the switching valve is switched to a defrosting operation position, so that the indoor heat exchanger and the heat exchange for defrosting are provided. , The refrigerant can be supplied in the order of the decompression device and the outdoor heat exchanger, and during normal heating operation, the defrosting heat exchanger is bypassed by switching the switching valve to the heating operation position,
An air conditioner, wherein a refrigerant can be supplied in the order of an indoor heat exchanger, a decompression device, and an outdoor heat exchanger, and excess refrigerant can be stored in the defrosting heat exchanger. 3. The air conditioner according to claim 1, wherein the switching valve comprises a four-way valve. 4. The air conditioner according to claim 1, wherein the heat exchanger for defrosting and the outdoor heat exchanger are integrally formed.