JP2002188873A - Refrigerating equipment of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner, in which defrosting can be performed without stopping heating operation. SOLUTION: In the refrigerating equipment, a first outdoor heat exchanger 3a is connected serially with first pressure-reducing equipment for cooling-cum- heating. A second outdoor heat exchanger 3b is provided parallel with the first heat exchanger 3a and connected serially with second pressure-reducing equipment 4a2. Opening-closing valves 9a1, 9b1 are branched from the discharge side of the compressor 1 and connected respectively between the heat exchangers and the pressure-reducing equipment. Two bypass tubes 9a, 9b are provided with the valves 9a1 and 9b1. When conditions for defrosting operation are satisfied in a heating operation, outdoor heat exchangers are defrosted alternately by opening/closing alternately the opening/closing valves installed in the bypass tubes without stopping the heating operation. Thus, cold air is not diffused in the room, and amenity is not disturbed 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 a refrigeration system for an air conditioner, and more particularly, to defrosting during a heating operation.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a refrigerating apparatus for an air conditioner includes a compressor 1, a four-way valve 2 for switching a flow path, an outdoor heat exchanger 3, and a decompressor for cooling and heating in an outdoor unit 10. 4a and a pressure reducing device 4 composed of a heating-only pressure reducing device 4c in which a check valve 4b is connected in parallel, while the indoor heat exchanger 5 is disposed in the indoor unit 20, and the compressor 1, the four-way valve 2, The outdoor heat exchanger 3, the decompression device 4, and the indoor heat exchanger 5 are sequentially connected by piping to form a refrigeration cycle. And during heating operation,
For example, the temperature of the pipe between the outdoor heat exchanger 3 and the pressure reducing device 4 is detected, and when the temperature becomes equal to or lower than a predetermined temperature, the temporary heating operation is stopped to perform the cooling operation, and the frost formed on the outdoor heat exchanger 3 is removed. Defrosting, so-called reverse cycle defrosting, is generally performed. However, in this method, when the defrosting operation condition is reached, the heating operation is temporarily stopped and the defrosting operation is performed, so that there is a problem that comfort is significantly impaired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide an air conditioner refrigeration system capable of defrosting without stopping the heating operation.

[0004]

In order to solve the above-mentioned problems, the present invention provides a compressor, a four-way valve for switching a flow path, two outdoor heat exchangers connected in parallel, and a decompression device capable of switching between cooling and heating. And an indoor heat exchanger are connected in series with each other in a refrigeration system of an air conditioner to constitute a refrigeration cycle. In the refrigeration apparatus, a cooling / heating decompressor is connected in series with the two outdoor heat exchangers, and the compressor Two bypass pipes each having an on-off valve are branched from the discharge side, and the two bypass pipes are respectively connected to two connection pipes for connecting the outdoor heat exchanger and the cooling / heating decompressor. In the defrosting operation, an on-off valve provided in each of the bypass pipes is alternately opened and closed to alternately defrost the two outdoor heat exchangers.

The first outdoor heat exchanger and the second outdoor heat exchanger are refrigeration devices for an air conditioner in which the left and right sides are disposed symmetrically in the outdoor unit.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigeration system for an air conditioner according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a refrigerant circuit diagram showing an embodiment of an air conditioner refrigeration apparatus according to the present invention, and FIG. 2 is a layout view of a main part of an outdoor unit showing an embodiment of an air conditioner refrigeration apparatus according to the present invention. In FIG. 1, 1
0 is a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, and a decompression device 4.
And 20 is an indoor unit provided with the indoor heat exchanger 5 and a thermistor 5a for detecting indoor pipe temperature. As shown in FIG. 1, one side of a first outdoor heat exchanger 3a which is connected to the four-way valve 2 from the discharge side and the suction side of the compressor 1 and constitutes the outdoor heat exchanger 3 from the four-way valve 2 A of the junction between the first heat exchanger 3b and one side of the second outdoor heat exchanger 3b;
The four-way valve 2 connects the discharge side of the compressor 1 to the outdoor heat exchanger 3 or the indoor heat exchanger 5 and connects the suction side of the compressor 1 to the indoor heat exchanger 5 or the outdoor heat exchanger. The connection is switched to the exchange 3. From the other side of the first outdoor heat exchanger 3a, one side of a first cooling / heating decompressor 4a1 constituting a part of the decompression device 4 is connected in series, and from the other side of the second outdoor heat exchanger 3b. One side of a second cooling / heating decompressor 4a2 that constitutes a part of the decompression device 4 is connected in series. The other side of the first cooling / heating decompressor 4a1 and the other side of the second cooling / heating decompressor 4a2 are connected by a pipe at a junction B, and constitute another part of the decompression device 4 from the junction B. The pipe is connected to a one-side junction C of the check valve 4b and the heating-dedicated pressure reducer 4c connected in parallel. The other side junction D of the check valve 4b and the heating-dedicated pressure reducer 4c connected in parallel.
To one side of the indoor heat exchanger 5 to form a refrigeration cycle.

[0007] The discharge side of the compressor 1 is further branched at a branch point E, and a first opening / closing valve 9a1 is inserted through the first opening / closing valve 9a1.
Is connected to a junction F between one side of the first bypass pipe 9a and one side of the second bypass pipe 9b inserted through the second on-off valve 9b1, and the other side of the first bypass pipe 9a is connected to the first side of the first bypass pipe 9a. Is connected to a pipe connection point G between the outdoor heat exchanger 3a and the first cooling / heating decompressor 4a1, and the other side of the second bypass pipe 9b is connected to the second outdoor heat exchanger 3b and the second cooling / heating decompression. Vessel 4a2
Is connected to the pipe connection point H.

As shown in FIG. 2, a suction port 12 is provided on the rear and side surfaces of the outdoor unit 10, and an air outlet 13 is provided on the front surface. The L-shaped first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b, which are bent from the back surface to the side surface of the outdoor unit 10, facing the suction port 12, are symmetrically arranged. Have been. Further, a blower 6 composed of a propeller fan 6a and a driving motor 6b faces the air outlet 13, and the compressor 1 provided with an accumulator 7 is disposed substantially at the center. On the back side of the outdoor unit 10, pipe connection valves 8a and 8b connected to the indoor heat exchanger 5 provided in the indoor unit 20 shown in FIG. 1 are arranged.

Next, the control method and operation of the above configuration will be described. Usually, the first on-off valve 9a1 and the second on-off valve 9b1 are closed. First, the cooling operation will be described. In the case of the cooling operation, by switching the four-way valve, the high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 1 passes through the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b, respectively. The heat exchange with the outdoor air causes the heat of condensation to be deprived and liquefied. The liquid passes through the cooling / heating decompressor 4a1 and the second cooling / heating decompressor 4a2 constituting the decompression device 4 and are merged. After evaporating in the indoor heat exchanger 5 to remove the heat of evaporation from the indoor air, the indoor air is cooled and vaporized, flows into the accumulator 1a through the four-way valve 2, and is completely vaporized.
It is sucked into the compressor 1 and compressed.

Next, the heating operation will be described. In the case of the heating operation, the four-way valve is switched in the opposite manner to the case of the cooling operation, and the high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 1 passes through the indoor heat exchanger 5 to be condensed into the indoor air. The heat is deprived of heat and the indoor air is heated and liquefied. After passing through the decompressor 4c dedicated to heating, which constitutes the decompressor 4, it is branched and depressurized through the decompressor 4a1 for cooling and heating and the second decompressor 4a2 for cooling and heating. Then, each of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b evaporates and takes away the heat of evaporation from the outdoor air to vaporize, flow into the accumulator 1a via the four-way valve 2, and completely vaporize. Thereafter, it is sucked into the compressor 1 and compressed. During this heating operation, the blower 6
Thus, the outside air blown to the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b is deprived of the heat of evaporation by the refrigerant, cooled, and dewed. In particular, if the heating operation is continued when the outside air temperature is low, the outside air is further cooled, and the water droplets that have condensed on the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b freeze and frost to form a heat exchange efficiency. For example, when the temperature of the thermistor 5a is lower than a predetermined temperature, it is determined that frost has formed, and the defrosting operation is started.

FIG. 3 is an operation table showing operation states of the first on-off valve 9a1 and the second on-off valve 9b1. As described above, when the defrosting operation condition is satisfied, as shown in FIG. 3, the normally closed first on-off valve 9a1 and second on-off valve 9b1 are moved for a predetermined time interval, for example, three times. It is controlled to open alternately at minute intervals. This allows
The outdoor heat exchanger 3 to which the open on-off valve is connected
The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows through and is heated and defrosted, but the outdoor heat exchanger 3 connected to the closed on-off valve operates as an evaporator.
The heating operation is also continued, and the problem that the cold air is blown into the room during the defrosting operation and the comfort is deteriorated as in the related art is eliminated.

[0012]

As described above, according to the refrigeration system for an air conditioner according to the present invention, when the defrosting operation condition is satisfied during the heating operation, the opening and closing provided in each of the bypass pipes without stopping the heating operation. Since the valves can be opened and closed alternately to defrost the outdoor heat exchangers alternately, cold air is not blown into the room during the defrosting operation as in the related art, thus maintaining comfort. It is.

[Brief description of the drawings]

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

FIG. 2 is a layout view of a main part of an outdoor unit showing an embodiment of an air conditioner refrigeration apparatus according to the present invention.

FIG. 3 is an operation table showing an operation state of an on-off valve of the refrigeration system of the air conditioner according to the present invention.

FIG. 4 is a refrigerant circuit diagram illustrating a conventional refrigeration apparatus for an air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 3a 1st outdoor heat exchanger 3b 2nd outdoor heat exchanger 4 Decompression device 4a1 1st cooling / heating decompression device 4a2 2nd cooling / heating decompression device 4b Check valve 4c Decompressor for heating 5 Indoor heat exchanger 6 Blower 6a Propeller fan 6b Motor 7 Accumulator 8a Valve for pipe connection 8b Valve for pipe connection 9a First bypass pipe 9a1 First open / close valve 9b Second bypass pipe 9b1 Second On-off valve

Claims (2)

[Claims] 1. A refrigeration cycle in which a compressor, a four-way valve for switching a flow path, two outdoor heat exchangers connected in parallel, a decompression device capable of switching between cooling and heating, and an indoor heat exchanger are sequentially connected by piping. In the refrigeration apparatus for an air conditioner, a cooling / heating decompressor is connected in series with the two outdoor heat exchangers, and two bypass pipes each having an on-off valve are branched from the discharge side of the compressor. The two bypass pipes are respectively connected to two connection pipes for pipe connection between the outdoor heat exchanger and the cooling / heating decompressor. At the time of the defrosting operation, an on-off valve provided for each of the bypass pipes is provided. A refrigeration system for an air conditioner, wherein the two outdoor heat exchangers are alternately opened and closed to defrost alternately. 2. The outdoor heat exchanger according to claim 1, wherein the two outdoor heat exchangers are symmetrically arranged in the outdoor unit.
A refrigeration apparatus for the air conditioner according to the above.