JPH0518645A - Heat pump type air conditioning device - Google Patents

Abstract

PURPOSE:To improve defrosting capacity by a method wherein production of a fluctuation in a cycle is reduced and the high power of a refrigerant compressor is generated. CONSTITUTION:In a refrigeration cycle 1 wherein a refrigerant compressor 3, an outdoor heat-exchanger 4, and an indoor heat-exchanger 5 are interconnected in an annular manner through a four-way valve 2, a first pressure reducing device 9 and a first bypass passage 10 bypassing the first pressure reducing device 9 are located between the outdoor and indoor heat-exchangers 4 and 5, and a solenoid valve 11 opened during defrost operation is located in the first bypass passage 10. A second pressure reducing device 12 and a second bypass passage 13 bypassing the second pressure reducing device 12 are located between the four-way valve 2 and the indoor heat-exchanger 5, and a solenoid valve 14 closed during defrosting operation is located in the second bypass passage 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner.

[0002]

2. Description of the Related Art Conventionally, in a heat pump type air conditioner, a defrosting operation for melting frost adhering to an outdoor heat exchanger during heating is performed. This defrosting operation is performed by temporarily switching the four-way valve from the heating cycle to a cooling cycle, and radiating the high temperature gas refrigerant discharged from the refrigerant compressor with the outdoor heat exchanger.

Therefore, during defrosting, the indoor heat exchanger functions as a refrigerant evaporator as in the case of cooling, so that even if air is blown to the indoor heat exchanger, indoor heating cannot be performed, and the indoor heat exchanger is not heated. Ventilation has been stopped.

Therefore, in Japanese Patent Laid-Open No. 61-262560, during heating operation, part of the gas refrigerant discharged from the refrigerant compressor is guided to the outlet side of the outdoor heat exchanger and the opening of the expansion valve is increased. Then, the technique of defrosting the outdoor heat exchanger without interrupting the indoor heating is disclosed by raising the low pressure side.

[0005]

However, in the above-mentioned prior art, since the indoor heat exchanger for heating is on the high pressure side, the refrigerant is cooled and the high pressure is reduced. Therefore, the power of the refrigerant compressor (= The amount of heat radiation) decreases. Further, the refrigerant has two phases in the indoor heat exchanger and the outdoor heat exchanger. In these two phases, the heat dissipation performance of the heat exchanger is good, and the heat dissipation amount seems to increase at first glance, but in reality, if the heat dissipation performance of the heat exchanger is good, the high and low pressures decrease, and the power of the refrigerant compressor (= discharge Calorie)
Becomes smaller. Furthermore, since the amount of heat used for defrosting differs greatly between the initial stage of defrosting and immediately before the completion of defrosting, the cycle fluctuates and the power fluctuation of the refrigerant compressor also increases.

The present invention has been made based on the above circumstances, and an object thereof is a heat pump type air conditioner capable of improving the capacity at the time of defrosting by obtaining a large power with little cycle fluctuation. To provide a device.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a refrigerant compressor for compressing and discharging a sucked refrigerant, and a four-way method for switching the circulation direction of the refrigerant discharged from the refrigerant compressor. A valve, an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air, an indoor heat exchanger for exchanging heat between the refrigerant and indoor air, and between the outdoor heat exchanger and the indoor heat exchanger. A first decompression device that is arranged to decompress the passing refrigerant, a first bypass path that bypasses the first decompression device and connects the outdoor heat exchanger and the indoor heat exchanger, and opens and closes the bypass path. A first on-off valve, and a second decompression device arranged between the outdoor heat exchanger and the four-way valve or between the indoor heat exchanger and the four-way valve to decompress the passing refrigerant, Bypassing the second pressure reducing device, the outdoor heat exchanger and the four-way valve Others a second bypass path connecting said four-way valve and the indoor heat exchanger, and a second on-off valve for opening and closing the second bypass passage, the and the heating operation during the cooling operation,
When the first opening / closing valve is closed and the second opening / closing valve is opened to defrost the outdoor heat exchanger together with indoor heating, the first opening / closing valve is opened and the second opening / closing valve is closed. The technical means comprises a control means for controlling the opening / closing of the first opening / closing valve and the second opening / closing valve.

[0008]

In the heat pump type air conditioner of the present invention having the above structure, the refrigerant discharged from the refrigerant compressor is closed by closing the second opening / closing valve when defrosting the outdoor heat ventilation together with the indoor heating. After being decompressed by the second decompression device, it is led to the outdoor heat exchanger in the cooling cycle and to the indoor heat exchanger in the heating cycle. Then, by opening the first on-off valve, the refrigerant flowing between the outdoor heat exchanger and the indoor heat exchanger passes through the first bypass passage.

Therefore, at the time of defrosting, the low-pressure heating gas refrigerant decompressed by the second decompressor circulates in the outdoor heat exchanger and the indoor heat exchanger, and if the cooling cycle is performed,
After defrosting with the outdoor heat exchanger, the indoor heat exchanger radiates the remaining amount of heat to heat the room, and if it is a heating cycle,
After radiating heat in the indoor heat exchanger, the remaining heat quantity is used to defrost the outdoor heat exchanger.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the heat pump type air conditioner of the present invention will be described with reference to FIGS. FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner.

The heat pump type air conditioner of this embodiment switches the circulation direction of the refrigerant flowing through the refrigeration cycle 1 to perform cooling / heating operation. The refrigerating cycle 1 includes a four-way valve 2 that switches the circulation direction of the refrigerant, and the refrigerant compressor 3, the outdoor heat exchanger 4, and the indoor heat exchanger 5 are annularly connected via the four-way valve 2.

The refrigerant compressor 3 compresses and discharges the gas refrigerant sucked by the accumulator 6 provided upstream thereof. The outdoor heat exchanger 4 exchanges heat between the refrigerant and the outdoor air in response to the blow of the blower 7. The indoor heat exchanger 5 receives the air blown by the blower 8 and exchanges heat between the refrigerant and the indoor air.

Between the outdoor heat exchanger 4 and the indoor heat exchanger 5, a first pressure reducing device 9 for reducing the pressure of the refrigerant passing therethrough is arranged, and the first pressure reducing device 9 is bypassed to provide outdoor heat. First bypass passage 10 connecting the exchanger 4 and the indoor heat exchanger 5
Is provided. Then, in the first bypass passage 10,
An electromagnetic valve 11 (first opening / closing valve) that opens and closes the first bypass passage 10 is arranged.

Between the four-way valve 2 and the indoor heat exchanger 5, a second pressure reducing device 12 for reducing the pressure of the passing refrigerant is provided, and the second pressure reducing device 12 is bypassed and the four-way valve 2 is provided.
A second bypass path 13 that connects the indoor heat exchanger 5 to the indoor heat exchanger 5 is provided. The second bypass passage 13 is provided with an electromagnetic valve 14 (second opening / closing valve) that opens and closes the second bypass passage 13.

The solenoid valve 11 and the solenoid valve 14 are energized and controlled by a controller 15 (control means), which will be described later, and open when energized, and close when energized.

The refrigeration cycle 1 forms a cooling cycle for performing a cooling operation and a heating cycle for performing a heating operation by switching the four-way valve 2 by the control device 15 and controlling energization of the solenoid valves 11 and 14. During the cycle, it is possible to perform the defrosting operation for defrosting the frost adhering to the outdoor heat exchanger 4 together with the indoor heating.

This heat pump type air conditioner can select a cooling mode for performing a cooling operation, a heating mode for performing a heating operation, and a defrosting mode for performing a defrosting operation. Then, according to each selected mode, the control device 1
Switching of the four-way valve 2 by 5 and energization control of the solenoid valve 11 and the solenoid valve 14 are performed.

When the cooling mode is selected, the control device 15 causes the refrigerant discharged from the refrigerant compressor 3 to transfer the refrigerant to the outdoor heat exchanger 4.
The four-way valve 2 is switched so as to flow to the side, and the solenoid valve 14 is energized to open the second bypass passage 13. At this time, the solenoid valve 11 is not energized and is in a closed state, so that the first bypass passage 10 is closed. The flow of the refrigerant in this cooling mode is shown by the broken line arrow in FIG.

When the heating mode is selected, the refrigerant compressor 3
The four-way valve 2 is switched so that the discharged refrigerant flows toward the indoor heat exchanger 5, and the solenoid valve 14 is energized to open the second bypass passage 13. At this time, the solenoid valve 11 is not energized and is in a closed state, and therefore the first bypass passage 1
0 is closed. Figure 1 shows the flow of refrigerant in this heating mode.
Is indicated by a dashed-dotted arrow.

When the defrosting mode is selected, the four-way valve 2 is
As in the heating mode, the refrigerant discharged from the refrigerant compressor 3 is switched to flow toward the indoor heat exchanger 5, and the solenoid valve 11 is energized to open the first bypass passage 10. At this time, the solenoid valve 14 is not energized and is in a closed state, so the second bypass passage 13 is closed. The flow of the refrigerant in the defrosting mode is shown by a solid arrow in FIG.

Next, the operation of this embodiment will be described. a) When the cooling mode is selected. The refrigerant discharged from the refrigerant compressor 3 sequentially flows through the four-way valve 2, the outdoor heat exchanger 4, the first pressure reducing device 9, the indoor heat exchanger 5, the second bypass passage 13, the four-way valve 2, and the accumulator 6.
It is sucked into the refrigerant compressor 3 again and the above cycle is repeated. Thus, the air cooled by the indoor heat exchanger 5 is blown into the room by the blower 8 to cool the room.

B) When the heating mode is selected. The refrigerant discharged from the refrigerant compressor 3 sequentially flows through the four-way valve 2, the second bypass passage 13, the indoor heat exchanger 5, the first pressure reducing device 9, the outdoor heat exchanger 4, the four-way valve 2, and the accumulator 6,
It is sucked into the refrigerant compressor 3 again and the above cycle is repeated. Thereby, the air heated by the indoor heat exchanger 5 is blown into the room by the blower 8 to heat the room.

C) When the defrosting mode is selected. A high-temperature, high-pressure gas refrigerant compressed by the refrigerant compressor 3 (see FIG. 2).
The state point a) in the Mollier diagram shown in FIG. 2 passes through the four-way valve 2 and is decompressed by the second pressure reducing device 12 (state point b in FIG. 2) to become a high-temperature, low-pressure gas refrigerant, and the indoor heat exchanger 5 Flow into. Then, the indoor heating is performed by the heat exchange between the refrigerant and the indoor air in the indoor heat exchanger 5.

The refrigerant flowing out of the indoor heat exchanger 5 passes through the first bypass passage 10 and flows into the outdoor heat exchanger 4,
Since the refrigerant that has exchanged heat with the indoor air (state point c in FIG. 2) still retains a sufficient amount of heat, the outdoor heat exchanger 4 releases the remaining amount of heat (state point d in FIG. 2). Thus, the outdoor heat exchanger 4 is defrosted. The refrigerant flowing out of the outdoor heat exchanger 4 passes through the accumulator 6 and is sucked into the refrigerant compressor 3 again, and the above cycle is repeated.

During the defrosting operation, since the indoor heat exchanger 5 and the outdoor heat exchanger 4 are both on the low pressure side, it is possible to obtain a large power of the refrigerant compressor 3 by increasing the high pressure. Further, in the indoor heat exchanger 5 and the outdoor heat exchanger 4,
Since the state of the refrigerant is gas, the heat dissipation performance in the indoor heat exchanger 5 and the outdoor heat exchanger 4 is lower than that in the gas-liquid two-phase state. Therefore, the high pressure and the low pressure increase, and the power of the refrigerant compressor 3 increases. Furthermore, even if the amount of heat used for defrosting changes, the amount of heat used for heating is larger than the amount of heat used for defrosting, so there is no large cycle fluctuation.

Next, a second embodiment of the present invention will be described. FIG. 3 is a refrigeration cycle diagram of this embodiment. In the first embodiment, the defrosting operation is performed with the setting of the four-way valve 2 as the heating cycle, but in the present embodiment, the defrosting operation is performed in the cooling cycle.

Therefore, the refrigerating cycle 1 is provided with the second pressure reducing device 12 between the outdoor heat exchanger 4 and the four-way valve 2, and the second heat reducing device 12 is bypassed to the outdoor heat exchanger 4 and the four-way valve. A second bypass path 13 that connects the second bypass path 13 and the second bypass path 13 is provided, and an electromagnetic valve 14 is interposed in the second bypass path 13.

When the defrosting mode is selected, the refrigerant compressor 3
The four-way valve 2 is switched so that the discharged refrigerant flows toward the outdoor heat exchanger 4 side (cooling cycle),
The solenoid valve 14 is energized to open the second bypass passage 13. At this time, the solenoid valve 11 is not energized and is in a closed state, so that the first bypass passage 10 is closed. The flow of the refrigerant in the defrosting mode is shown by a solid arrow in FIG. In addition, the flow of the refrigerant in the cooling mode and the heating mode is shown by a dashed arrow and a dashed-dotted arrow, respectively.

In the case of the present embodiment, the high-temperature and low-pressure refrigerant decompressed by the second decompression device 12 first flows into the outdoor heat exchanger 4 and is discharged along with the heat exchange between the refrigerant and the outdoor air. The outdoor heat exchanger 4 is defrosted by the amount of heat. After that, the refrigerant that has passed through the first bypass passage 10 and flowed into the indoor heat exchanger 5 releases the remaining heat amount by heat exchange with the indoor air, thereby performing indoor heating.

Also in this second embodiment, both the indoor heat exchanger 5 and the outdoor heat exchanger 4 are on the low pressure side, and as in the first embodiment, a large power of the refrigerant compressor 3 can be obtained. At the same time, cycle fluctuation can be suppressed.

[0031]

The heat pump type air conditioner of the present invention, when performing defrosting of the outdoor heat exchanger as well as indoor heating,
The refrigerant discharged from the refrigerant compressor is decompressed by the second pressure reducing device and flows into the outdoor heat exchanger or the indoor heat exchanger.
During the defrosting operation, the first bypass passage provided between the outdoor heat exchanger and the indoor heat exchanger is opened, so that both the outdoor heat exchanger and the indoor heat exchanger are on the low pressure side. become.

Therefore, a large power (= heat radiation amount) of the refrigerant compressor can be obtained, and the defrosting ability can be improved. Further, since both defrosting and heating are performed on the low pressure side, even if the amount of heat used for defrosting changes, the cycle does not change significantly.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner.

FIG. 2 is a Mollier diagram for explaining the operation of this embodiment.

FIG. 3 is a refrigeration cycle diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 2 Four-way valve 3 Refrigerant compressor 4 Outdoor heat exchanger 5 Indoor heat exchanger 9 First pressure reducing device 10 First bypass passage 11 Electromagnetic valve (first opening / closing valve) 12 Second pressure reducing device 13 Second bypass passage 14 Solenoid valve ( Second opening / closing valve) 15 Control device (control means)

Claims (1)

Claims: 1. A refrigerant compressor for compressing and discharging sucked refrigerant, b) a four-way valve for switching the circulation direction of the refrigerant discharged from the refrigerant compressor, and c) refrigerant. And an outdoor heat exchanger for exchanging heat with the outdoor air, d) an indoor heat exchanger for exchanging heat between the refrigerant and the indoor air, and e) between the outdoor heat exchanger and the indoor heat exchanger. A first decompression device that is arranged to decompress the passing refrigerant; f) a first bypass path that bypasses the first decompression device and connects the outdoor heat exchanger and the indoor heat exchanger; g) this A first opening / closing valve for opening / closing a bypass passage; and h) arranged between the outdoor heat exchanger and the four-way valve or between the indoor heat exchanger and the four-way valve to reduce the pressure of the refrigerant passing therethrough. 2) a decompression device, i) bypassing this second decompression device and connecting with the outdoor heat exchanger. A four-way valve or a second bypass passage connecting the indoor heat exchanger and the four-way valve, j) a second opening / closing valve for opening and closing the second bypass passage, and k) the first bypass valve during cooling operation and heating operation. When the on-off valve is closed and the second on-off valve is opened to defrost the outdoor heat exchanger together with indoor heating, the first on-off valve is opened and the second on-off valve is closed. A heat pump type air conditioner comprising one opening / closing valve and a control means for controlling opening / closing of the second opening / closing valve.