JPH10292960A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform the defrosting over the whole area on the outlet side from the inlet of an outdoor heat exchanger by switching the flow of the refrigerant in the outdoor heat exchanger at least once during the defrosting operation of the outdoor heat exchanger. SOLUTION: In the first defrosting operation, the hot and high-pressure gas to be discharged from a compressor 1 flows from an inlet 3a side to an outlet 3b side by closing a two-way valve 25 so as to communicate ports P1 , P2 of a four-way valve 9 with ports P3 , P4 , and the defrosting can be performed over approximately intermediate area from the inlet 3a side. After the defrosting operation is completed, only the two-way valve 25 is opened to flow the hot and high-pressure gas from the compressor 1 from an approximately center part of an outdoor heat exchanger 3 to the outlet 3b side. A part of the hot and high pressure gas flows from the inlet 3a toward the outlet 3b without passing through the two-way valve 25, but the volume of the flowing gas is small because of the pressure loss in the outdoor heat exchanger 3. As a result, the defrosting can be performed over the whole area of the outdoor heat exchanger 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an air conditioner.

[0002]

2. Description of the Related Art Generally, in an air conditioner capable of a cooling operation and a heating operation, in a cooling operation mode, refrigerant discharged from a compressor by a four-way valve is supplied to an outdoor heat exchanger → an expansion valve → an indoor heat exchanger. A refrigeration cycle that passes through the exchanger and returns to the compressor is configured.

On the other hand, in the heating operation mode, by switching the four-way valve, the refrigerant discharged from the compressor passes through the indoor heat exchanger → the expansion valve → the outdoor heat exchanger and returns to the compressor again. It constitutes a cycle.

[0004]

In the outdoor heat exchanger in the heating operation mode, the outdoor heat exchanger functions as an evaporator for gasifying the refrigerant, and frost is liable to be attached due to the influence of the outside air temperature. Since the efficiency of heat exchange deteriorates when frost adheres, it is necessary to perform defrosting periodically.

In the defrosting operation for defrosting, high-temperature and high-pressure gas from a compressor is sent to an outdoor heat exchanger for defrosting. During this defrosting operation, high-temperature and high-pressure gas is sent in. At the entrance of the outdoor heat exchanger, although the frost is surely removed, a phenomenon that is difficult to take at the exit occurs.

[0006] This is because a difference occurs in the gas temperature of the refrigerant between the inlet and the outlet of the outdoor heat exchanger, and the gas temperature that was high at the inlet gradually decreases in the process of performing work. Conceivable. For this reason, it takes time to reliably remove frost from the inlet to the outlet region, which is not desirable in terms of heating operation efficiency.

Accordingly, an object of the present invention is to provide an air conditioner capable of efficiently performing defrosting over the entire area from the inlet to the outlet of the outdoor heat exchanger.

[0008]

In order to achieve the above object, the present invention is directed to a heating method, wherein a refrigerant discharged from a compressor passes through an indoor heat exchanger, a throttling means, and an outdoor heat exchanger. In the air conditioner constituting the heating cycle returning to the compressor again, during the defrosting operation of the outdoor heat exchanger,
The flow of the refrigerant in the outdoor heat exchanger is switched at least once.

[0009] In a preferred embodiment, during the defrosting operation of the outdoor heat exchanger, the inlet and the outlet of the outdoor heat exchanger are switched by the switching means to reverse the flow of the refrigerant in the outdoor heat exchanger.

According to this air conditioner, in the heating operation mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger, the throttling means, the outdoor heat exchanger, and returns to the compressor in a heating cycle. And in the indoor heat exchanger,
The heat exchanged and warmed air is blown into the room.

To perform defrosting of the outdoor heat exchanger during the heating operation, first, high-temperature, high-pressure gas from the compressor is sent from the inlet side to the outlet side of the outdoor heat exchanger. Thereby, the defrosting is completed from the inlet area of the outdoor heat exchanger to almost the intermediate area.

Next, the switching means switches between the inlet and the outlet so that, for example, a high-temperature, high-pressure gas is sent from the outlet to the inlet.

As a result, the frost on the outlet side area of the outdoor heat exchanger is quickly removed, and the defrosting can be completed in a short time over the entire area of the outdoor heat exchanger.

In this case, it is desirable that the switching means be constituted by a four-way valve provided in the refrigeration cycle.

Alternatively, the switching means comprises a four-way valve provided in the refrigeration cycle and a two-way valve having two modes, open and closed.

Alternatively, it is constituted by two three-way valves provided in the refrigeration cycle.

Further, an embodiment may be adopted in which the refrigerant is caused to flow from the middle of the outdoor heat exchanger toward the outlet by the switching means during the defrosting operation of the outdoor heat exchanger.

The switching means of this embodiment is desirably constituted by a two-way valve provided in the refrigeration cycle and having two modes of opening and closing.

Alternatively, control is performed based on the output of a temperature detection sensor for detecting the temperature of the outdoor heat exchanger.

Alternatively, the control may be performed based on the operation history of the air conditioner.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an air conditioner provided with first and second four-way valves 9 and 11 in addition to a compressor 1, an outdoor heat exchanger 3, an expansion valve 5 as a throttling means, and an indoor heat exchanger 7. FIG. 3 shows a circuit diagram of the heating operation mode.

The first four-way valve 9 operates in the heating mode.
The ports P1 and P3 are switched by a signal from the control unit 13 so that the ports P2 and P4 communicate with each other. In the cooling operation mode as shown in FIG. 4, the ports P1 and P2 are switched by a signal from the control unit 13 so that the ports P3 and P4 communicate with each other.

The second four-way valve 11 is controlled to switch between the ports P1 and P2 by a signal from the control unit 13 so that the ports P3 and P4 communicate with each other in the heating / cooling amount operation mode.

Thus, in the cooling operation mode,
As shown in FIG. 4, the refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger 3 serving as a condenser, the expansion valve 5 and the indoor heat exchanger 7 serving as an evaporator, and returns to the compressor 1 again. Will be configured.

In the heating operation mode shown in FIG. 1, the refrigerant discharged from the compressor 1 passes through the indoor heat exchanger 7 serving as a condenser, the expansion valve 5, and the outdoor heat exchanger 3 serving as an evaporator. Then, a heating cycle returning to the compressor 1 again is constituted.

The control unit 13 controls the first and second four-way valves 9 and 11 in the heating operation mode and the cooling operation mode.
In addition to the switching control, for example, based on an operation mode programmed in advance, the first and second four-way valves 9 and 11 are provided at the timing of entering the defrosting operation and in the defrosting operation mode.
Has a function of switching control of each.

That is, as shown in FIG. 2, during the first defrosting operation, the first four-way valve 9 connects the ports P1 and P2 with each other.
The ports P3 and P4 are controlled so as to communicate with each other. The second four-way valve 11 is controlled such that ports P1 and P2 communicate with ports P3 and P4, respectively.

As shown in FIG. 3, during the second defrosting operation, the first four-way valve 9 is controlled such that the ports P1 and P2 communicate with the ports P3 and P4, respectively.
The second four-way valve 11 has ports P1 and P2 connected to port P3.
And P4 are controlled so as to communicate with each other.

The switching from the primary defrosting operation to the secondary defrosting operation is performed by inputting a detection signal from a temperature detection sensor 15 provided on the inlet 3a side of the outdoor heat exchanger 3 to the control unit 13. Thus, the control unit 13 switches based on the detection signal from the temperature detection sensor 15. In addition, the secondary defrosting operation is canceled after the operation for a certain period of time by a signal from a timer circuit incorporated in the control unit 13, and is again switched to the heating operation mode.

According to this air conditioner, in the heating operation mode, the refrigerant discharged from the compressor 1 passes through the indoor heat exchanger 7, the expansion valve 5, and the outdoor heat exchanger 3, and returns to the compressor 1 again. Make up the heating cycle back. At this time, the refrigerant heats and condenses the air in the indoor heat exchanger 7. The heated air is blown into the room by a fan (not shown).

On the other hand, in the outdoor heat exchanger 3, the refrigerant evaporates and is gasified. During this operation, frost adheres to the outdoor heat exchanger 3 due to the influence of the outside air temperature. After a certain period of operation, the first defrosting operation is started. In this defrosting operation, the first four-way valve 9 is connected to the ports P1 and P1 as shown in FIG.
2, the ports P3 and P4 communicate with each other,
In the second four-way valve 11, ports P1 and P2 communicate with ports P3 and P4, respectively, and the high-temperature and high-pressure gas discharged from the compressor 1 flows from the inlet 3a of the outdoor heat exchanger 3 to the outlet 3b. Flowing towards. As a result, defrosting is performed from the entrance 3a region to almost the intermediate region.

Next, after the first defrosting operation is completed, a second defrosting operation is started. At this time, as shown in FIG. 3, only the second four-way valve 11 switches the ports P1 and P3 so that the ports P2 and P4 communicate with each other. Accordingly, the high-temperature and high-pressure gas discharged from the compressor 1 flows from the outlet 3b of the outdoor heat exchanger 3 toward the inlet 3a. As a result, defrosting is performed from the area of the outlet 3b to almost the intermediate area, and the defrosting is reliably completed in a relatively short time from the inlet 3a of the outdoor heat exchanger 3 to the entire area of the outlet 3b.

FIGS. 5 and 6 show another embodiment in the defrosting operation mode.

That is, in addition to the second four-way valve 11, the discharge side of the compressor 1 and the port P3 of the second four-way valve 11 are controlled by a signal from the control unit 13 into two modes, open and closed. The two-way valve 17 communicates with each other.

The other components are the same as those shown in FIG.

Therefore, according to this embodiment, in the heating operation mode, the two-way valve 17 is controlled to be closed, so that the refrigerant discharged from the compressor 1 is supplied to the indoor heat exchanger 7,
A heating cycle that returns to the compressor 1 through the expansion valve 5 and the outdoor heat exchanger 3 is configured. At this time, the refrigerant heats and condenses the air in the indoor heat exchanger 7. The heated air is blown into the room by a fan (not shown).

On the other hand, in the outdoor heat exchanger 3, the refrigerant evaporates and is gasified. During this operation, frost adheres to the outdoor heat exchanger 3 due to the influence of the outside air temperature. The first defrosting operation is started. In this defrosting operation,
As shown in FIG. 5, the two-way valve 17 is controlled to be open,
The first four-way valve 9 has ports P1 and P3 and ports P2 and P2.
4 communicate with each other. The second four-way valve 11 is port P
1 and P2 communicate with ports P3 and P4 respectively,
The high-temperature and high-pressure gas discharged from the compressor 1 passes through a two-way valve 17 and a second four-way valve 11, as indicated by a dotted arrow.
It flows from the inlet 3a side of the outdoor heat exchanger 3 toward the outlet side 3b. As a result, defrosting is performed from the entrance 3a region to almost the intermediate region.

Next, after the completion of the first defrosting operation, a second defrosting operation is started. At this time, as shown in FIG. 6, only the second four-way valve 11 switches the ports P1 and P3 so that the ports P2 and P4 communicate with each other. As a result, the high-temperature and high-pressure gas discharged from the compressor 1 passes through the two-way valve 17 and the second four-way valve 11 from the outlet 3b side of the outdoor heat exchanger 3 to the inlet 3a as shown by the dotted arrows. Flows towards the side. As a result, defrosting is performed from the area of the outlet 3b to almost the intermediate area, and the defrosting is reliably completed in a relatively short time from the inlet 3a of the outdoor heat exchanger 3 to the entire area of the outlet 3b.

FIGS. 7 and 8 show an embodiment in which a first three-way valve 19 and a second three-way valve 21 are used instead of the second four-way valve 11 to perform a defrosting operation. It is.

That is, a first three-way valve 19 is provided on the inlet 3a side of the outdoor heat exchanger 3 constituting the refrigeration cycle, and a second three-way valve 21 is provided on the outlet 3b side, and the first and second three-way valves are provided. 19 and 21 have ports P1, P2 and P3.

The port P1 of the first three-way valve 19 is connected to the port P2 of the first four-way valve 9, and the port P2 is connected to the outdoor heat exchanger 3.
3a and port P3 is the outlet 3b of the outdoor heat exchanger 3.
The side and the second three-way valve 21 are connected and connected to each other.

The port P1 of the second three-way valve 21 is connected to the outlet 3b of the outdoor heat exchanger 3, and the port P2 is connected to the expansion valve 5.
The port P <b> 3 has a circuit configuration that is connected to and communicates with the inlet 3 a of the outdoor heat exchanger 3 and the first three-way valve 19.

The first and second three-way valves 19 and 21 are switched by a signal from the control unit 23 so that the ports P1 and P2 communicate with each other in the heating operation mode and in the first defrosting operation. . Further, at the time of the second defrosting operation, switching is controlled by a signal from the control unit 23 so that the ports P1 and P3 communicate with each other.

The controller 23 determines the timing and the time of defrosting from the past operation history of the air conditioner, and determines the first and second defrosting operations and the first and second defrosting operations from the heating operation mode and the heating operation mode. An operation program for switching to the heating operation mode again after completion of the secondary defrosting operation is incorporated, and functions to output a command signal based on the program.

The other components are the same as those shown in FIG. 1, and therefore, are denoted by the same reference numerals and will not be described in detail.

Therefore, according to this embodiment, in the heating operation mode, the first four-way valve 9 is connected to the port P1
As shown by the solid line, the refrigerant discharged from the compressor 1 passes through the indoor heat exchanger 7, the expansion valve 5, and the outdoor heat exchanger 3, and again passes through the compressor 1 and P3. Constructing a heating cycle back to. At this time, the refrigerant heats and condenses the air in the indoor heat exchanger 7. The heated air is blown into the room by a fan (not shown).

On the other hand, in the outdoor heat exchanger 3, the refrigerant evaporates and is gasified. During this operation, frost adheres to the outdoor heat exchanger 3 due to the influence of the outside air temperature. After a certain period of operation, the first defrosting operation is started. In this defrosting operation, the first four-way valve 9 is connected to the ports P1 and P1 as shown in FIG.
2 is switched so that the ports P3 and P4 respectively pass, and the first three-way valve 19 is configured such that the ports P1 and P2 are
The three-way valve 21 has ports P1 and P2 communicating with each other, and the high-temperature and high-pressure gas discharged from the compressor 1 is supplied from the inlet 3a side to the outlet side 3b of the outdoor heat exchanger 3 as shown by a dotted line.
Flows towards As a result, defrosting is performed from the entrance 3a region to almost the intermediate region.

Next, after the completion of the first defrosting operation, a second defrosting operation is started. At this time, as shown in FIG.
Are switched so that the ports P1 and P3 communicate with each other. Thereby, the high-pressure / high-pressure gas discharged from the compressor 1 flows from the outlet 3b of the outdoor heat exchanger 3 toward the inlet 3a. As a result, the exit 3b
Defrosting is performed from the region to almost the intermediate region, and the defrosting is reliably completed in a relatively short time from the inlet 3a to the outlet 3b of the outdoor heat exchanger 3 in the entire region.

FIGS. 9 and 10 show an embodiment in which a defrosting operation is performed by using a two-way valve 25 having two modes of opening and closing, instead of the second four-way valve 11. is there.

That is, the circuit configuration is such that the two-way valve 25 is provided in the bypass circuit 27 connecting the inlet 3a of the outdoor heat exchanger 3 and the substantially intermediate region.

The two-way valve 25 is connected between the heating mode and the first mode.
Switching is controlled by a signal from the control unit 29 to be closed during the next defrosting operation and to be opened during the second defrosting operation.

The control unit 29 determines the time and the time of defrosting from the past operation history of the air conditioner, and performs the first and second defrosting operations and the first and second defrosting operations from the heating operation mode and the heating operation mode. An operation program for switching to the heating operation mode again after completion of the secondary defrosting operation is incorporated, and functions to output a command signal based on the program.

The other components are the same as those shown in FIG. 1, and thus the same reference numerals are given and the detailed description is omitted.

Therefore, according to this embodiment, in the heating operation mode, the first four-way valve 9 is connected to the port P1
As shown by the solid line, the refrigerant discharged from the compressor 1 passes through the indoor heat exchanger 7, the expansion valve 5, and the outdoor heat exchanger 3, and again passes through the compressor 1 and P3. Constructing a heating cycle back to. At this time, the refrigerant heats and condenses the air in the indoor heat exchanger 7. The heated air is blown into the room by a fan (not shown).

On the other hand, in the outdoor heat exchanger 3, the refrigerant evaporates and is gasified. During this operation, frost adheres to the outdoor heat exchanger 3 due to the influence of the outside air temperature. After a certain period of operation, the first defrosting operation is started. In this defrosting operation, as shown in FIG. 9, the two-way valve 25 is controlled to be closed, and the first four-way valve 9 communicates with the ports P1 and P2 and the ports P3 and P4. The high temperature / high pressure gas discharged from 1 flows from the inlet 3a side of the outdoor heat exchanger 3 to the outlet side 3b as shown by a dotted line. As a result, defrosting is performed from the entrance 3a region to almost the intermediate region.

Next, after the completion of the first defrosting operation, a second defrosting operation is started. At this time, as shown in FIG.
Only 5 is controlled to be open. Therefore, the high-temperature and high-pressure gas discharged from the compressor 1 flows from the substantially central portion of the outdoor heat exchanger 3 toward the entrance 3b. At this time,
Part of the high-pressure gas does not pass through the two-way valve 25 but flows from the inlets 3a to 3b of the outdoor heat exchanger 3, but the flow amount is small due to the pressure loss in the heat exchanger 3. As a result,
Defrosting is performed substantially from the middle region to the outlet 3b region, and the defrosting is reliably completed in a relatively short time from the inlet 3a to the outlet 3b side of the outdoor heat exchanger 3.

[0058]

As described above, according to the air conditioner of the present invention, the flow of the high-temperature and high-pressure gas can be switched in the outdoor heat exchanger during the defrosting operation. The temperature difference between the inlet and the outlet can be eliminated, and reliable defrosting can be completed in a short time over the entire area.

Therefore, the heating performance can be improved by shortening the defrosting operation time.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an air conditioner in a heating operation mode according to the present invention.

FIG. 2 is a circuit diagram of the air conditioner during a first defrosting operation.

FIG. 3 is a circuit diagram of the air conditioner during a second defrosting operation.

FIG. 4 is a circuit diagram of the air conditioner in a cooling operation mode.

FIG. 5 is a circuit diagram of an air conditioner at the time of a primary defrosting operation using a second four-way valve and a two-way valve.

FIG. 6 is a circuit diagram of the air conditioner during the second defrosting operation in FIG. 5;

FIG. 7 is a circuit diagram of the air conditioner at the time of the primary defrosting operation using the first and second four-way valves.

8 is a circuit diagram of the air conditioner during the second defrosting operation in FIG.

FIG. 9 is a circuit diagram of the air conditioner during a first defrosting operation using a two-way valve.

FIG. 10 is a circuit diagram of the air conditioner during the second defrosting operation in FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 compressor 3 indoor heat exchanger 3a inlet 3b outlet

Claims (9)

[Claims] An air conditioner comprising a heating cycle in which a refrigerant discharged from a compressor in a heating operation mode passes through an indoor heat exchanger, a throttling means, and an outdoor heat exchanger and returns to a compressor again. An air conditioner wherein the flow of the refrigerant in the outdoor heat exchanger is switched at least once during the defrosting operation of the outdoor heat exchanger. 2. The outdoor heat exchanger according to claim 1, wherein, during the defrosting operation of the outdoor heat exchanger, an inlet and an outlet of the outdoor heat exchanger are switched by the switching means to reverse the flow of the refrigerant in the outdoor heat exchanger. The air conditioner according to any one of the preceding claims. 3. The air conditioner according to claim 2, wherein the switching means is constituted by a four-way valve provided in the refrigeration cycle. 4. The air conditioner according to claim 2, wherein the switching means comprises a four-way valve provided in the refrigeration cycle and a two-way valve having two modes of opening and closing. 5. The switching means is provided in a refrigeration cycle,
The air conditioner according to claim 2, comprising two three-way valves. 6. The air conditioner according to claim 1, wherein during the defrosting operation of the outdoor heat exchanger, the switching means causes the refrigerant to flow from the middle of the outdoor heat exchanger toward the outlet. . 7. The air conditioner according to claim 6, wherein the switching means comprises a two-way valve provided in the refrigeration cycle, the valve being open and closed. 8. The air conditioner according to claim 2, wherein the switching means controls based on an output of a temperature detection sensor for detecting a temperature of the outdoor heat exchanger. 9. The air conditioner according to claim 2, wherein the switching means controls based on an operation history of the air conditioner.