JP3480217B2 - Air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly to a pipe connection structure for shortening the defrosting time of an outdoor heat exchanger.

[0002]

2. Description of the Related Art As shown in FIG. 1, an air conditioner includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, and a pressure reducing device 4.
And the indoor heat exchanger 5 are sequentially connected by piping, and the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 during the heating operation is passed through the four-way valve 2 as shown by the solid arrow to show the indoor heat exchanger 5 To the suction side of the compressor 1 through the four-way valve 2 again after being heat-exchanged with the room air and liquefied under reduced pressure by the decompression device 4 and gasified by heat exchange with the outdoor air in the outdoor heat exchanger 3. I'm supposed to come back. In addition, during the cooling operation and during the defrosting operation for preventing the formation of ice in the outdoor heat exchanger 3, the four-way valve 2 is switched, so that the flow of the refrigerant changes as indicated by the broken line arrow, and the outdoor heat exchanger 3 and the indoor heat exchanger are exchanged. The operation of the container 5 is reversed. In the defrosting operation, high-temperature and high-pressure refrigerant gas will flow into the outdoor heat exchanger 3,
The refrigerant that has flowed into the outdoor heat exchanger 3 is deprived of heat due to heat exchange with the outdoor air, and the temperature decreases, so it takes time to defrost the outlet side where the refrigerant flows downstream. Therefore, as a means for shortening the defrosting time, a bypass circuit having an on-off valve 6 is provided between the discharge side of the compressor 1 and the intermediate portions 3a, 3b of the outdoor heat exchanger 3 so that the compressor 1 A part of the discharged high-temperature and high-pressure refrigerant gas is supplied to the intermediate portions 3a and 3b of the outdoor heat exchanger 3.

FIG. 4 shows an example of piping connection of the outdoor heat exchanger 3. The outdoor heat exchanger 3 is arranged in two rows in front and rear with respect to the air flow generated by the operation of the blower fan 7 shown in FIG. The upper and lower ends of the heat transfer tubes on the rear row side are located higher than those on the front row side, and the upper and lower two connecting portions that connect the upper and lower ends of the heat transfer tubes on the front row and the rear row, respectively, to the outside. Intermediate portions 3a and 3b of the heat exchanger 3 are used.
A bypass circuit having the above-mentioned on-off valve 6 is provided between a and 3b and the discharge side of the compressor 1, and the on-off valve 6 is opened during the defrosting operation so that the high-temperature high-pressure refrigerant gas discharged from the compressor 1 is discharged. By bypassing a part of the heat transfer tubes of the outdoor heat exchanger 3 into the intermediate portions 3a and 3b, high temperature is obtained in the downstream side from the intermediate portions 3a and 3b of the outdoor heat exchanger 3 to the outlet side (pressure reducing device 4 side). The refrigerant gas is flowed to eliminate the delay of defrosting on the downstream side, and the defrosting time of the entire outdoor heat exchanger 3 is shortened.

[0004]

However, in the conventional outdoor heat exchanger 3, the pipe connection between the intermediate portions 3a and 3b and the outlet side of the bypass circuit is formed in a substantially Y shape as shown in FIG. Since the branched pipe 10 is used horizontally, the flow of the refrigerant is unnatural when performing the cooling operation and the like, and the refrigerant from the bypass circuit and the rear row side of the outdoor heat exchanger 3 are operated during the defrosting operation. The merging with the refrigerant that has passed through the heat transfer tube becomes unnatural, which is a factor that reduces the amount of refrigerant supplied from the bypass circuit. Therefore, in the present invention,
The object is to provide an air conditioner that solves these problems.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are sequentially arranged. The heat transfer tubes of the outdoor heat exchanger are arranged in two rows before and after the air flow generated by the rotation of the outdoor fan, and the upper and lower ends of the heat transfer tubes on the rear row side are on the front row side. The upper and lower two connecting portions which are located at a position higher than that and which connect the upper ends and the lower ends of the heat transfer tubes in the front row and the rear row, respectively, are defined as the intermediate portion of the outdoor heat exchanger, and the two intermediate portions and the compressor. A bypass circuit provided with an on-off valve between the discharge side of the compressor and the on-off valve is opened during the defrosting operation, and a part of the refrigerant gas discharged from the compressor is supplied to the two intermediate portions to form a rear row. With the refrigerant gas split up and down from the inlet side of the middle row, In the air conditioner configured to circulate to the side, the connection ports between the outlet side of the bypass circuit and the upper and lower intermediate portions of the outdoor heat exchanger are provided above and below the upper and lower ends of the heat transfer tubes on the rear row side, respectively. The configuration.

For connecting the outlet side of the bypass circuit and the upper and lower intermediate portions of the outdoor heat exchanger, two connecting pipes having open ends at the upper and lower sides thereof are used, and the upper ends of the respective connecting pipes are connected. The outlet side of the bypass circuit is connected to, the upper end and the lower end of the heat transfer tubes on the rear row side of the outdoor heat exchanger are respectively connected to the intermediate open end, and the lower end of the heat transfer tubes on the front row side of the outdoor heat exchanger is connected. The upper and lower ends are connected together.

Further, the refrigerant that has flowed up and down above the middle stage of the heat transfer tubes in the front row or the rear row of the outdoor heat exchanger is made to flow out from the middle stage of the heat transfer tubes in the rear row or the front row. Also,
A solenoid valve or an electronic expansion valve is used as the opening / closing valve. When an electronic expansion valve is used as the opening / closing valve, the electronic expansion valve is gradually opened immediately before the start of defrosting and gradually closed at the end of defrosting. In addition, after opening the opening / closing valve immediately before the start of the defrosting operation, the four-way valve is switched from the heating operation state to the cooling operation state, and when the defrosting is completed, the four-way valve is switched to the heating operation state, and then the opening / closing is performed. The valve should be closed.

[0008]

According to the present invention, the outdoor heat exchanger used in the refrigerant circuit is constructed in two rows in front and rear with respect to the air flow, and the upper and lower ends of the heat transfer tubes on the rear row side are more than those on the front row side. Is also at a high position, and the upper and lower two joints connecting the upper end and the lower end of the heat transfer tubes in the front row and the rear row are the middle portion of the outdoor heat exchanger, and these two middle portions and the discharge side of the compressor. A bypass circuit equipped with an on-off valve is provided between the two, and during defrosting operation, the on-off valve is opened, and a part of the refrigerant gas discharged from the compressor is supplied to the two intermediate portions, from the inlet side of the rear row middle stage. In an air conditioner configured to circulate to the outlet side of the front row middle stage together with the refrigerant gas split up and down, the connection port between the outlet side of the bypass circuit and the upper and lower two intermediate portions of the outdoor heat exchanger is located in the rear row side. Provided above and below both upper and lower ends of the heat transfer tube Configuration and then, since the refrigerant gas from the bypass circuit is then supplied from the high position the better the flow of hot refrigerant gas, so that can be shortened defrosting time.

[0009]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows a refrigerant circuit of an air conditioner, where 1 is a compressor, 2 is a four-way valve that switches the flow of refrigerant discharged from the compressor 1 in accordance with heating operation, cooling operation, etc., 3
Is an outdoor heat exchanger that is configured in two rows before and after the air flow, 4
Is a decompression device using a capillary tube or the like, 5 is an indoor heat exchanger, and these are sequentially connected by pipes.
A bypass circuit having an opening / closing valve 6 composed of a solenoid valve or an electronic expansion valve is provided between the discharge side of the heat exchanger and the intermediate portions 3a and 3b of the heat transfer tubes of the outdoor heat exchanger 3. In addition, 7 is an outdoor fan controlled by an outdoor control unit (not shown), 8
Is an indoor fan controlled by an indoor control unit (not shown).

In the above structure, the refrigerant during the heating operation circulates as indicated by the solid line arrow, and the refrigerant gas compressed to high temperature and high pressure by the compressor 1 passes through the four-way valve 2 and flows through the indoor heat exchanger 5. The indoor fan 8 exchanges heat with the indoor air, the decompression device 4 liquefies the decompressed air, and while flowing through the outdoor heat exchanger 3, the outdoor fan 7 exchanges heat with the outdoor air to gasify the gas, and the gas is compressed again via the four-way valve 2. Return to the suction side of machine 1. During this heating operation, when the temperature of the outdoor heat exchanger 3 detected by the temperature detecting means (not shown) becomes equal to or lower than a predetermined value, the four-way valve 2 is switched to switch to the defrosting operation.
In this embodiment, the on-off valve 6 is opened prior to the switching of the four-way valve 2, and a part of the refrigerant gas discharged from the compressor 1 is transferred to the outdoor heat exchanger 3 as shown by the white arrow in FIG. It is made to flow into the intermediate portions 3a and 3b of the heat pipe to suppress a sudden pressure change in the refrigerant circuit.

When a solenoid valve is used as the opening / closing valve 6, this solenoid valve is opened immediately before the four-way valve 2 is switched to start defrosting and closed after the four-way valve 2 is switched at the end of defrosting. It is like this. When an electronic expansion valve is used as the opening / closing valve 6, this electronic expansion valve is gradually opened immediately before the start of defrosting and gradually closed at the end of defrosting. Further, the indoor fan 8 and the outdoor fan 7 are stopped at the start of defrosting, and the outdoor fan 7 starts the blowing operation at the end of defrosting,
After that, the indoor fan 8 is started to blow. By performing such an operation, a rapid pressure change in the refrigerant circuit is suppressed, so that it is not necessary to temporarily stop the compressor 1 when switching the four-way valve 2. The broken line arrows shown in FIG. 1 indicate the flow of the refrigerant during the cooling operation and the defrosting operation.

FIG. 2 shows an outdoor heat exchanger 3 which is a feature of the present invention.
2 shows the pipe connection configuration of FIG. The outdoor heat exchanger 3 is arranged in two rows in front and rear with respect to the air flow generated by the operation of the outdoor fan 7, and the upper and lower ends of the heat transfer tubes on the rear row side are located higher than those on the front row side. The upper and lower connecting portions for connecting the upper ends and the lower ends of the heat transfer tubes in the front row and the rear row are the intermediate portion 3a of the outdoor heat exchanger 3,
3b, and a bypass circuit including the above-mentioned on-off valve 6 is provided between the intermediate portions 3a and 3b and the discharge side of the compressor 1. Further, an inlet and an outlet through which refrigerant flows in and out during a cooling operation, a heating operation, etc. are provided in the middle of the front row and the rear row. Further, the outlet side of the bypass circuit and the connection ports between the upper and lower intermediate portions 3a and 3b of the outdoor heat exchanger 3 are provided above and below the upper and lower ends of the rear row side heat transfer tube, respectively.

The outlet side of the bypass circuit and the upper and lower intermediate portions 3a and 3b of the outdoor heat exchanger 3 are connected to each other by two connecting pipes 9 (for example, a T-shape) having open ends at the upper and lower sides thereof. Connection pipe), the outlet side of the bypass circuit is connected to the upper ends of the upper and lower connecting pipes 9, the upper end and the lower end of the heat transfer pipes on the rear row side of the outdoor heat exchanger 3 are connected to the intermediate open end, and the lower end is connected. The upper end and the lower end of the heat transfer tubes on the front row side of the outdoor heat exchanger 3 are connected to each other. With such a pipe configuration, the flow of the refrigerant in the upper and lower coupling portions is good not only during the defrosting operation but also during the heating operation and the cooling operation as shown in FIG. The flow of high temperature refrigerant flowing in from
Defrosting on the downstream side from the intermediate portions 3a, 3b, which has been apt to be delayed in the past, to the outlet side is accelerated, and the defrosting time of the entire outdoor heat exchanger 3 can be shortened.

[0014]

EFFECT OF THE INVENTION In the case of the air conditioner having the outdoor heat exchanger having the pipe structure as described above, the defrosting operation time is further shortened, so that the decrease in the room temperature due to the defrosting operation is reduced. Improves comfort during heating operation.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to the present invention and a conventional example.

FIG. 2 is a piping connection configuration diagram of an outdoor heat exchanger showing an embodiment of the present invention.

FIG. 3 is a diagram showing the flow of the refrigerant during heating operation and cooling operation of the outdoor heat exchanger connected by piping according to the present invention.

FIG. 4 is a pipe connection configuration diagram of an outdoor heat exchanger showing a conventional example.

[Explanation of symbols]

1 compressor 2 four-way valve 3 outdoor heat exchanger 3a, 3b middle part 4 Pressure reducing device (capillary tube) 5 Indoor heat exchanger 6 Open / close valve (solenoid valve or electronic expansion valve) 7 outdoor fan 8 indoor fans 9 Connection pipe (T-shaped connection pipe)

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-194000 (JP, A) JP-A-6-74603 (JP, A) JP-A-6-241623 (JP, A) JP-A-64- 6662 (JP, A) JP 2-64393 (JP, A) JP 5-340593 (JP, A) Actual opening 2-114882 (JP, U) Actual opening Sho 62-127467 (JP, U) Actual development Sho 58-158893 (JP, U) Actual development Sho 61-46367 (JP, U) Actual development Sho 58-174661 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 47/02 550 F25B 47/02 530 F25B 39/00 F25B 39/02 F25B 39/04

Claims (7)

(57) [Claims] 1. A compressor, a four-way valve, an outdoor heat exchanger,
The decompression device and the indoor heat exchanger are connected by piping in sequence,
The heat transfer tubes of the outdoor heat exchanger are arranged in two rows in front and rear with respect to the air flow generated with the rotation of the outdoor fan, and the upper and lower ends of the heat transfer tubes on the rear row side are located at a position higher than that on the front row side. Yes, the upper and lower two coupling portions for coupling the upper end and the lower end of the heat transfer tubes in the front row and the rear row respectively are the middle portions of the outdoor heat exchanger, and the two middle portions and the discharge side of the compressor are provided. A bypass circuit equipped with an on-off valve is provided, and during defrosting operation, the on-off valve is opened, and a part of the refrigerant gas discharged from the compressor is supplied to the two intermediate portions, and the upper and lower sides from the inlet side of the rear row middle stage In the air conditioner configured to be circulated to the outlet side of the front row middle stage together with the refrigerant gas that has been split into two, the connection port between the outlet side of the bypass circuit and the upper and lower two intermediate portions of the outdoor heat exchanger on the rear row side. Above the upper and lower ends of the heat transfer tube Only the air conditioner, characterized by comprising. 2. The connection between the outlet side of the bypass circuit and the upper and lower intermediate portions of the outdoor heat exchanger uses two connecting pipes having open ends at the upper and lower sides thereof, and the upper ends of the respective connecting pipes. The outlet side of the bypass circuit is connected to, the upper end and the lower end of the heat transfer tubes on the rear row side of the outdoor heat exchanger are respectively connected to the intermediate open end, and the lower end of the heat transfer tubes on the front row side of the outdoor heat exchanger is connected. The upper end and the lower end are connected to each other.
Air conditioner described. 3. The refrigerant flowing vertically above and below the middle stage of the heat transfer tubes in the front row or rear row of the outdoor heat exchanger is discharged from the middle stage of the heat transfer tubes in the rear row or front row.
Air conditioner described. 4. The air conditioner according to claim 1, wherein an electromagnetic valve is used as the opening / closing valve. 5. The air conditioner according to claim 1, wherein an electronic expansion valve is used as the opening / closing valve. 6. When an electronic expansion valve is used as the opening / closing valve,
The air conditioner according to claim 4, wherein the electronic expansion valve is gradually opened immediately before the start of defrosting and gradually closed at the end of defrosting. 7. After opening the on-off valve immediately before the start of the defrosting operation, switching the four-way valve from a heating operation state to a cooling operation state, and after switching the four-way valve to a heating operation state at the end of defrosting. The air conditioner according to claim 1, wherein the on-off valve is closed.