JP2000205673A - Refrigeration cycle for air conditioning equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration cycle of air conditioning equipment which can improve performance during the cooling operation without lowering heating performance. SOLUTION: In a refrigeration cycle of air conditioning equipment which comprises a compressor 2, a four-way valve 3, an outdoor heat exchanger 4 having two passes 4a and 4b, a throttle 5 and an auxiliary heat exchanger 6 housed in an outdoor unit 1, and a room heat exchanger 11 having two passes 11a and 11b housed in a room unit 10 and builds a refrigerant circuit by piping these components sequentially, the auxiliary heat exchanger 6 for sub cool is arranged between the outdoor heat exchanger 4 and the throttle 5, and a bypass circuit is provided across both ends of the auxiliary heat exchanger 6 to be equipped with a check valve 7 for bypassing so that the refrigerant will not flow through the auxiliary heat exchanger 6 during the heating operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle of an air conditioner, and more particularly to an auxiliary heat exchanger for improving performance during cooling.

[0002]

2. Description of the Related Art FIG. 7 is a refrigerant circuit diagram of a refrigeration cycle of an air conditioner showing an example of the related art. As shown in the drawing, a refrigerant circuit of a refrigeration cycle of a conventional air conditioner has an outdoor unit 1
, A four-way valve 3 and an outdoor heat exchanger 4
, Squeezing device 5, and two passes 11 stored in indoor unit 10
a and 11b, which are sequentially connected to form a refrigerant circuit.

In the above configuration, during the cooling operation, the refrigerant flow in the outdoor unit 1 flows from the compressor 2 to the outdoor heat exchanger 4 via the four-way valve 3 as indicated by a broken line arrow. The refrigerant flows from the outdoor heat exchanger 4 through the expansion device 5 into the indoor heat exchanger 11 of the indoor unit 10. Then, the refrigerant returns to the compressor 2 via the four-way valve 3 of the outdoor unit 1. During the heating operation, the refrigerant flow path is as indicated by the solid arrow,
The flow returns to the compressor 2 via a route reverse to that during cooling.

In the conventional refrigeration cycle of an air conditioner, an auxiliary heat exchanger 13 is provided between the indoor heat exchanger 11 of the indoor unit 10 and the expansion device 5 in order to improve the heating performance. Some are designed to ensure sufficient subcooling (supercooling) during operation. Further, there is a refrigerator having a small and improved heating capacity, such as a refrigeration cycle disclosed in Japanese Patent Application Laid-Open No. Sho 56-108062. In this case, the auxiliary heat exchanger 13 of the indoor unit 10 is connected to the indoor heat exchanger. Disposed between the exchanger 11 and the compressor 2;
When disposed at this position, it is not possible to secure subcooling (supercooling).

[0005] However, the above-mentioned indoor unit 10 is designed to sufficiently secure subcooling (supercooling) during cooling operation.
No improvement in performance during cooling operation with the same configuration as that described above is found, including only for cooling.

On the other hand, in the refrigeration cycle of a heat pump type air conditioner, if the same configuration as the above-described indoor unit 10 is provided in the outdoor unit 1 in order to improve the performance during the cooling operation, the pressure loss during heating becomes large. Therefore, it is necessary to raise the evaporating temperature to a temperature at which the outdoor heat exchanger 4 serving as an evaporator partially frosts early and the portion does not frost. As a result, the path of the outdoor heat exchanger 4 evaporates. There is a problem that the heating performance may be degraded due to the limitation.

[0007]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a refrigeration cycle of an air conditioner in which performance during cooling operation is improved without lowering heating performance.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and mainly comprises a compressor, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger. In a refrigeration cycle of an air conditioner having a refrigerant circuit constituted by connecting pipes sequentially with a refrigerant pipe, an auxiliary heat exchanger for subcooling is disposed between the outdoor heat exchanger and the expansion device. To do.

[0009] A bypass circuit having an on-off valve for bypassing refrigerant so as not to flow to the auxiliary heat exchanger during heating is provided between both ends of the auxiliary heat exchanger.

Further, the number of passes of the auxiliary heat exchanger is made smaller than the number of passes of the outdoor heat exchanger or the number of passes of the indoor heat exchanger.

Alternatively, the number of passes of the auxiliary heat exchanger is
The number of passes of the outdoor heat exchanger is equal to the number of passes of the indoor heat exchanger.

On the other hand, the on-off valve is a check valve.

Alternatively, the on-off valve is an electromagnetic valve.

The solenoid valve is opened during heating.
It is controlled to be closed during cooling.

On the other hand, the auxiliary heat exchanger is arranged on the windward side of the outdoor heat exchanger.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on embodiments with reference to the accompanying drawings. FIG.
1 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a first embodiment of the present invention. The same numbers are used for the same components.

In the figure, 1 is an outdoor unit, 2 is a compressor, 3
Is a four-way valve, 4 is an outdoor heat exchanger, 6 is an auxiliary heat exchanger, 5 is a throttle device, 10 is an indoor unit, and 11 is an indoor heat exchanger.

First, the refrigeration cycle of the air conditioner of the present invention will be described. A compressor 2 housed in an outdoor unit 1
An outdoor heat exchanger 4 having a four-way valve 3 and two paths 4a, 4b
, An expansion device 5, an auxiliary heat exchanger 6, and an indoor heat exchanger 1 having two paths 11 a and 11 b stored in the indoor unit 10.
1, and these are sequentially connected by piping to form a refrigerant circuit.

Here, the outdoor heat exchanger 4 and the expansion device 5
The auxiliary heat exchanger 6 for subcooling is disposed between the auxiliary heat exchanger 6 and the subcooler. Further, a bypass circuit having a check valve 7 (open / close valve) is provided between both ends of the auxiliary heat exchanger 6 so that the refrigerant does not flow into the auxiliary heat exchanger 6 during heating.

In the above configuration, the operation of the present invention will be described next.
The effect will be described. According to this embodiment, at the time of cooling, the refrigerant does not flow through the check valve 7 but flows through the auxiliary heat exchanger 6, so that subcooling (supercooling) can be sufficiently ensured. Thus, the cooling performance can be improved.

On the other hand, at the time of heating, the refrigerant flows through the check valve 7 and does not flow through the auxiliary heat exchanger 6, so that the pressure loss does not increase and the deterioration of the heating performance can be prevented.

FIG. 2 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a second embodiment of the present invention. In the case of this embodiment, the refrigeration cycle is exclusively for cooling, and an auxiliary heat exchanger 6 for subcooling is arranged between the outdoor heat exchanger 4 and the expansion device 5. Further, since it is exclusively used for cooling, a bypass circuit including the four-way valve 3 and the on-off valve is unnecessary.

The operation of this embodiment is the same as that of the above-described embodiment, and since the refrigerant flows through the auxiliary heat exchanger 6,
Subcooling (supercooling) can be sufficiently secured. The effect is the same as that of the above-described embodiment, and the cooling performance can be improved.

FIG. 3 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a third embodiment of the present invention. In the case of this embodiment, the number of passes of the auxiliary heat exchanger 6 is smaller than the number of passes of the outdoor heat exchanger 4 or the number of passes of the indoor heat exchanger 11.

The operation according to this embodiment is that the auxiliary heat exchanger 6 easily takes a subcool due to the difference in the number of passes.
This is because it works effectively. The effect is the same as that of the above-described embodiment, and the cooling performance can be improved.

FIG. 4 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a fourth embodiment of the present invention. In this embodiment, the number of passes of the auxiliary heat exchanger 6 is equal to the number of passes of the outdoor heat exchanger 4 and the number of passes of the indoor heat exchanger 11.

The bypass circuit as in the above-described embodiment becomes unnecessary due to the path balance. The effect of this embodiment can improve the cooling performance as in the above-described embodiment.

FIG. 5 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a fifth embodiment of the present invention. In this embodiment, the on-off valve is an electromagnetic valve 8. A control unit 9 for controlling the electromagnetic valve 8 is provided in the air conditioner main body, and the electromagnetic valve 8 is controlled to be open during heating and closed during cooling via the control unit 9.

The operation of this embodiment is that the control unit 9 automatically controls the solenoid valve 8 to be opened during heating and closed during cooling.

The effect is the same as that of the above embodiment, and the cooling performance can be improved.

FIG. 6 is an explanatory diagram of an auxiliary heat exchanger in a refrigeration cycle of an air conditioner according to a sixth embodiment of the present invention. In this embodiment, the auxiliary heat exchanger 6 is disposed on the windward side of the outdoor heat exchanger 4.

In the operation of this embodiment, since the auxiliary heat exchanger 6 is disposed on the windward side, subcooling (supercooling) can be performed efficiently.

The effect is the same as that of the above embodiment, and the cooling performance can be further improved.

[0034]

As described above, according to the present invention, a compressor, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger are mainly used, and these are sequentially connected by refrigerant piping to form a refrigerant. In a refrigeration cycle of an air conditioner having a circuit, an auxiliary heat exchanger for subcooling is provided between the outdoor heat exchanger and the expansion device. As a result, it is possible to provide a refrigeration cycle of the air conditioner in which the performance during the cooling operation is improved without lowering the heating performance.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner showing a third embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a fourth embodiment of the present invention.

FIG. 5 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner according to a fifth embodiment of the present invention.

FIG. 6 is an explanatory diagram of an auxiliary heat exchanger in a refrigeration cycle of an air conditioner according to a sixth embodiment of the present invention.

FIG. 7 is a refrigerant circuit diagram including a refrigeration cycle of an air conditioner showing a conventional example.

[Description of Signs] 1 Outdoor unit 2 Compressor 3 Four-way valve 4 Outdoor heat exchanger 4a Pass 4b Pass 5 Throttle device 6 Auxiliary heat exchanger 7 Check valve 8 Solenoid valve 9 Control unit 10 Indoor unit 11 Indoor heat exchanger 11a Pass 11b Pass

Claims (8)

[Claims] 1. An air conditioner mainly comprising a compressor, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger, which are sequentially connected by refrigerant piping to form a refrigerant circuit. In the refrigeration cycle, an auxiliary heat exchanger for subcooling is provided between the outdoor heat exchanger and the expansion device. 2. A bypass circuit having an on-off valve for bypassing refrigerant so as not to flow into the auxiliary heat exchanger during heating is provided between both ends of the auxiliary heat exchanger. The refrigeration cycle of the air conditioner as described. 3. The air conditioner according to claim 2, wherein the number of passes of the auxiliary heat exchanger is smaller than the number of passes of the outdoor heat exchanger or the number of passes of the indoor heat exchanger. Refrigeration cycle. 4. The air conditioner according to claim 1, wherein the number of passes of the auxiliary heat exchanger is equal to the number of passes of the outdoor heat exchanger and the number of passes of the indoor heat exchanger. Refrigeration cycle. 5. The refrigeration cycle of an air conditioner according to claim 2, wherein the on-off valve is a check valve. 6. The refrigeration cycle of an air conditioner according to claim 2, wherein the on-off valve is an electromagnetic valve. 7. The refrigeration cycle of an air conditioner according to claim 6, wherein the solenoid valve is controlled to be open during heating and closed during cooling. 8. The refrigeration cycle of an air conditioner according to claim 1, wherein the auxiliary heat exchanger is disposed on the windward side of the outdoor heat exchanger.