JPH09138017A - Multi-chamber split type cooling and heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of harsh refrigerant sound even if a refrigerant recovering operation is transferred to normal cooling and heating simultaneous operation state. SOLUTION: The multi-chamber split type cooling and heating apparatus forms a refrigerating cycle by connecting a plurality of outdoor units 1a, 1b and a plurality of indoor units 5a, 5b, 5c by a tube 11 between the units having a high-pressure gas tube 12, a low-pressure gas tube 13 and a liquid tube 14 to make it possible to operate cooling and heating simultaneous operation, and comprises means 20 for controlling the refrigerant recovery for a predetermined period under the condition that the refrigerant recovery conditions are satisfied and transferring to the cooling and heating operation responsive to the load after the entire compressors 2a, 2b are stopped for a predetermined time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a plurality of outdoor units, a plurality of indoor units, and inter-unit piping, and cools or heats all of the plurality of rooms at the same time and cools one room at the same time. Alternatively, the present invention relates to a multi-room air conditioner that heats another room at the same time.

[0002]

2. Description of the Related Art Generally, a plurality of outdoor units and a plurality of indoor units are connected by unit piping consisting of a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe to enable simultaneous cooling and heating operations. A room air conditioner is known (Japanese Patent Laid-Open No. 1-247967).

In this type of multi-room air conditioner, for example, when one indoor unit is in heating operation and the other indoor unit is in cooling operation, the cooling and heating operations of all the indoor units are temporarily stopped. , After that, all the indoor units may be restarted in the simultaneous cooling and heating operation state. In this case, before restarting the operation of all the indoor units, the operation of once collecting the refrigerant of the refrigeration cycle to the outdoor unit must be performed. This refrigerant recovery operation is performed by simultaneously switching the switching valves of all indoor units to the heating or cooling side. Then, when the recovery of the refrigerant in all the indoor units is completed, the refrigerant recovery operation is shifted to the normal cooling and heating simultaneous operation state. That is, the switching valve of the indoor unit on the cooling operation side is switched from the heating side to the cooling side in order to heat one indoor unit again and cool the other indoor unit.

[0004]

However, when the refrigerant recovery control operation is performed, all the refrigerant is recovered in the outdoor unit, so that a difference in height occurs in the refrigerant pressure between the indoor unit having no refrigerant and the outdoor unit. If the refrigerant recovery control operation shifts to the normal simultaneous cooling and heating operation state while the pressure unbalance is left, there is a problem that annoying refrigerant noise (switching sound) is generated from the switching valve.

An object of the present invention is to solve the above problems and provide a multi-chamber cooling / heating apparatus capable of preventing the generation of annoying refrigerant noise even when the refrigerant recovery control operation returns to the original normal operating state. To do.

[0006]

According to a first aspect of the present invention, a plurality of outdoor units equipped with a compressor and a plurality of indoor units are provided between a unit including a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe. By connecting with piping to form a refrigeration cycle, cooling,
In a multi-room air conditioner that enables simultaneous heating,
Prior to the operation of this device, only the compressor is operated to perform control for recovering the refrigerant in the refrigeration cycle to the outdoor unit, and after stopping all compressors for a predetermined time, cooling and heating according to the load. This is a configuration provided with means for shifting to operation. According to this, after satisfying the refrigerant recovery condition and performing the refrigerant recovery control for a predetermined time, all the compressors are stopped for a predetermined time. Accordingly, there is no difference in height between the refrigerant pressures between the indoor unit and the outdoor unit, and the pressure imbalance can be eliminated. Therefore, after the refrigerant recovery control operation, even if the compressor is operated again to shift to the normal cooling / heating simultaneous operation operation according to the load of each room, the phenomenon of annoying refrigerant noise from the switching valve is significantly increased. Can be suppressed.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numerals 1a and 1b denote outdoor units, and a compressor 2 is provided in each of the outdoor units 1a and 1b.
a, 2b, outdoor heat exchangers 3a, 3b, outdoor fan 31
a, 31b and gas-liquid separators 4a, 4b are provided.

Reference numerals 5a, 5b and 5c denote indoor units, and indoor heat exchangers 6a, 6b and 6c are provided in the respective indoor units 5a, 5b and 5c.

The outdoor units 1a and 1b and the indoor unit 5
The units a, 5b and 5c are connected to each other by the unit piping 11.

The inter-unit pipe 11 is composed of a high-pressure gas pipe 12, a low-pressure gas pipe 13 and a liquid pipe 14, and each indoor unit 5a, 5b, 5c, each outdoor unit 1a, 1b, and the inter-unit pipe 11 serve as a refrigerant. A cycle is formed. The high pressure gas pipe 12 is connected to the compressors 2a and 2b through the refrigerant discharge pipes 7a and 7b, and the switching valve 9 is connected.
It is connected to the outdoor heat exchangers 3a and 3b via a and 9b, and is further connected to the indoor heat exchangers 6a, 6b and 6c via switching valves 15a, 15b and 15c.

The low-pressure gas pipe 13 is a refrigerant suction pipe 8a, 8b.
Through, is connected to the gas-liquid separators 4a, 4b, and
The outdoor heat exchangers 3a, 3 via the switching valves 10a, 10b.
b, and is further connected to the indoor heat exchangers 6a, 6b, 6c via the switching valves 16a, 16b, 16c. Further, the liquid pipe 14 is connected to the outdoor heat exchangers 3a and 3b via auxiliary refrigerant decompressors 18a and 18b such as an electric expansion valve, and further, a refrigerant decompressor 17a such as an electric expansion valve and the like.
Indoor heat exchangers 6a, 6b, 6 via 17b, 17c
c.

The outdoor units 1a, 1b are provided with controllers (hereinafter referred to as outdoor controllers) 100a, 100b for controlling the outdoor units, and the indoor units 5a, 5b, 5c are provided with controllers for controlling the indoor units ( Hereinafter, referred to as an indoor controller) 101a,
101b and 101c are provided, and each controller has
An overall controller 200 for controlling overall control is connected.

The overall controller 200 receives the required load signal sent from the indoor controllers 101a, 101b, 101c and outputs a drive control signal to the outdoor controllers 100a, 100b in response to the required load signal.

When this signal is sent, the outdoor controllers 100a and 100b cause the compressor 2 to
a, 2b, the outdoor fans 31a, 31b, and the switching valves 9a, 9b, 10a, 10b of the refrigerant passages are simultaneously or individually driven and controlled. In addition, the overall controller 2
00 is the indoor controller 101a, 101b, 101
A drive control signal is sent to the switching control valves 15a, 15b, 1
The drive control of 5c, 16a, 16b, and 16c is carried out.

Next, the operation of the above-mentioned multi-room type air conditioner will be described.

When all the rooms are to be cooled at the same time, the switching valves 9a and 9b of one of the outdoor heat exchangers 3a and 3b are opened, the other switching valves 10a and 10b are closed, and the indoor heat exchanger 6a, One of the switching valves 15a, 15 of 6b, 6c
b and 15c are closed, and the other switching valves 16a and 16
Open b and 16c.

According to this, the refrigerant discharged from the compressors 2a, 2b is discharged by the discharge pipes 7a, 7b, the switching valves 9a, 9b,
After sequentially flowing with the outdoor heat exchangers 3a and 3b to condense and liquefy, the indoor units 5a and 5a are passed through the liquid pipe 14.
It is distributed to the refrigerant pressure reducers 17a, 17b, 17c of b and 5c. Then, after being decompressed here, they are vaporized and vaporized by the respective indoor heat exchangers 6a, 6b, 6c, and the switching valves 16a,
16b, 16c, low pressure gas pipe 13, suction pipes 8a, 8b,
After passing through the gas-liquid separators 4a and 4b, the gas is sucked into the compressors 2a and 2b.

According to this, each indoor heat exchanger 6a, 6
Since b and 6c act as an evaporator, all the rooms are cooled at the same time.

On the contrary, when heating all the rooms at the same time, the switching valves 9a and 9b of one of the outdoor heat exchangers 3a and 3b are closed, the other switching valves 10a and 10b are opened, and the indoor heat exchanger 6a, One of the switching valves 15a, 15 of 6b, 6c
b and 15c are opened, and the other switching valves 16a and 16 are opened.
Close b and 16c.

As a result, the refrigerant discharged from the compressors 2a and 2b sequentially passes through the discharge pipes 7a and 7b and the high pressure gas pipe 12, and then the switching valves 15a, 15b and 15c and the indoor heat exchanger 6
a, 6b, 6c, where they are condensed and liquefied, respectively, and then decompressed by the refrigerant decompressors 17a, 17b, 17c and joined by the liquid pipes 14, and then the outdoor heat exchanger 3a,
After evaporating and vaporizing in 3b, the compressor 2 through the switching valves 10a and 10b, the suction pipes 8a and 8b, and the gas-liquid separators 4a and 4b in order.
It is inhaled to a and 2b.

According to this, each indoor heat exchanger 6a, 6
Since b and 6c act as a condenser, all the rooms are heated simultaneously.

When, for example, cooling two arbitrary chambers and heating one chamber at the same time, one switching valve 9a of the outdoor heat exchanger 3a is opened, and at the same time both the other switching valve 10a and the outdoor heat exchanger 3b are opened. Of the indoor units 5a, 5c for closing and cooling the switching valves 9b, 10b of
And open the other switching valves 16a and 16c,
In addition, one switching valve 15b of the indoor unit 5b for heating is opened and the other switching valve 16b is closed.

As a result, a part of the refrigerant discharged from the compressors 2a, 2b sequentially flows through the discharge pipe 7a and the switching valve 9a to the outdoor heat exchanger 3a, while the remaining refrigerant remains in the high pressure gas pipe 12. After that, it flows to the switching valve 15b of the indoor unit 5b for heating and the indoor heat exchanger 6b, and is condensed and liquefied by the indoor heat exchanger 6b and the outdoor heat exchanger 3a. The refrigerant condensed and liquefied in the indoor heat exchanger 6b and the outdoor heat exchanger 3a passes through the liquid pipe 14 and the indoor unit 5a,
After being decompressed by the refrigerant decompressor 17a, 17c of 5c, it is evaporated and vaporized by the respective indoor heat exchangers 6a, 6c, and after that, it is merged by the low pressure gas pipe 13 through each switching valve 16a, 16c and sucked. It is sucked into the compressor 2 through the pipes 8a and 8b and the gas-liquid separators 4a and 4b in order.

According to this, since the indoor heat exchanger 6b acts as a condenser, one of the chambers is heated, and the other indoor heat exchangers 6a and 6c act as an evaporator, so that the other two chambers are heated. It is cooled.

Next, in the case of cooling one chamber and heating the two chambers, it is possible to operate the auxiliary refrigerant decompressor 18a.

For example, when the indoor unit 5b is used for cooling and the indoor units 5a and 5c are used for heating, the outdoor heat exchanger 3 is used.
a one switching valve 10a is opened, and the other switching valve 9a is opened.
Indoor unit 5 for cooling a, 9b, 10b
One switching valve 15b of b is closed, the other switching valve 16b is opened, and one switching valve 15a, 15c of the indoor unit 5a, 5c for heating is opened and the other switching valve 16a, 16c is closed.

As a result, the refrigerant discharged from the compressors 2a and 2b is distributed to the switching valves 15a and 15c through the discharge pipes 7a and 7b and the high-pressure gas pipe 12 in sequence, and the indoor heat exchangers 6a and 6a, respectively. It is condensed and liquefied at 6c. Then, the liquefied refrigerant is supercooled by the refrigerant pressure reducers 17 a and 17 c and flows into the liquid pipe 14. Part of the liquid refrigerant in the liquid pipe 14 is decompressed by the refrigerant decompressor 17b, then evaporated and vaporized by the indoor heat exchanger 6b, and the remaining liquid refrigerant is decompressed by the auxiliary refrigerant decompressor 18a, Outdoor heat exchanger 3
It is evaporated and vaporized by a, and the suction pipes 8a and 8b, the gas-liquid separator 4
It is sucked into the compressor 2 through a and 4b in sequence.

According to this, since the indoor heat exchangers 6a and 6c act as condensers, the two chambers are heated and the other indoor heat exchangers 6b act as evaporators, and the remaining one chamber is It is cooled.

When frost forms on the outdoor heat exchangers 3a and 3b acting as evaporators during the heating operation for all rooms,
Perform defrosting operation.

In this case, one of the switching valves 9a is opened and the other switching valve 10a is closed to guide a part of the high-temperature discharged refrigerant from the discharge pipe 7a to the outdoor heat exchanger 3a. Defrosting of the exchanger 3a is performed. After that, the one switching valve 9a is closed and the other switching valve 10 is closed.
a is opened, one of the outdoor heat exchangers 3a is made to act again as an evaporator, the switching valve 9b is opened, and the switching valve 1 is opened.
The outdoor heat exchanger 3b is defrosted by closing 0b and guiding a part of the high-temperature discharged refrigerant from the discharge pipe 7b to the other outdoor heat exchanger 3b.

According to this, it is possible to continuously perform the heating operation for all the rooms while defrosting the outdoor heat exchangers 3a, 3b alternately.

Next, the features of this embodiment will be described.

The feature of the multi-room type air conditioner of this embodiment is that after the refrigerant recovery control operation is performed for a predetermined time and all the compressors 2a, 2b are stopped for a predetermined time, on condition that the refrigerant recovery condition is satisfied. The means for shifting to the cooling and heating operation according to the load of each room is provided. A detailed description will be given with reference to FIGS. 1 and 2.

This transfer control is controlled by the overall controller 200 in FIG. The overall controller 200 performs control operation according to the sequence of FIG.

The multi-room type air conditioner is operated at the same time as normal air conditioning and heating. For example, the air conditioning is performed by the indoor unit 5b,
When heating with the indoor units 5a and 5c, as described above, one of the switching valves 10a and 10 of the outdoor heat exchanger 3a is used.
b, the other switching valves 9a, 9b are closed, and the one switching valve 15b of the indoor unit 5b for cooling is closed, the other switching valve 16b is opened, and one of the indoor units 5a, 5c for heating is closed. The switching valves 15a and 15c are opened, and the other switching valves 16a and 16c are closed. When controlled in this way, one of the indoor heat exchangers 6a, 6c
Acts as a condenser, the two chambers are heated, and the other indoor heat exchanger 6b acts as an evaporator, and the remaining one chamber is cooled.

Referring to FIG. 2, when the heating and cooling simultaneous operation as described above is started, it is first determined whether or not the refrigerant recovery condition is satisfied (step S1). The condition mentioned here is whether or not a predetermined time (for example, one hour) or more has elapsed since the previous operation stop, or whether the operation is the first in the morning. For example, if it is the first driving in the morning (Y
es), since the refrigerant recovery is required when the operation is restarted later, the refrigerant recovery control is performed (step S2). The overall controller 200 controls these. That is, in step S2, the general controller 200 simultaneously switches the switching valves 15
a, 15b, 15c are switched in the same direction, and the switching valves 16a, 16b, 16c are simultaneously switched in the same direction,
The refrigerant recovery operation is performed with the switching valve position in the heating operation state of all rooms or the switching valve position in the cooling operation state.

In this refrigerant recovery operation, the indoor unit 5a,
5b and 5c, the switching valves 15a, 15b and 15c are closed and the switching valves 16a, 16b and 16c are opened,
The refrigerant pressure reducers 17a, 17b, 17c are opened. On the other hand, in the outdoor units 1a and 1b, the switching valve 10
The valves a and 10b are closed, the switching valves 9a and 9b are opened, and the refrigerant pressure reducers 18a and 18b are fully closed. When the compressors 2a and 2b are operated under such a condition,
The refrigerant in each indoor unit 5a, 5b, 5c and in the inter-unit pipe 11 is generally collected in each outdoor unit 1a, 1b. Here, the operating time of this refrigerant recovery control is
If the operation immediately before that is unified to the heating operation state of all rooms, it is, for example, about 1 to 9 minutes, and if it is unified to the cooling operation state of all rooms, it is, for example, about 1 minute. That is, it is generally considered that it is the winter season when all the room heating operations are unified, and the temperature of the outdoor unit (outdoor heat exchanger) itself is low because the outside air temperature in which the outdoor unit is installed is low. Therefore, it takes a long time to collect the refrigerant in these outdoor units. On the other hand, it is generally considered that it is the summer season when all the room cooling operations are unified, and since the outside air temperature where the outdoor unit is installed is high, the temperature of the outdoor unit (outdoor heat exchanger) itself is high. Therefore, the time required to collect the refrigerant in these outdoor units is short. In such refrigerant recovery control, the temperature sensor E2 shown in FIG.
This is done by operating the compressor at full power until it reaches ° C. The temperature sensor E2 is an indoor heat exchanger 6a, 6
The coil temperatures of b and 6c are detected. That is, the fact that the temperature sensor E2 has reached 35 ° C. or higher means that the indoor heat exchangers 6a, 6b, 6c have run out of refrigerant, and this terminates the refrigerant recovery control operation.

When the refrigerant recovery control operation is completed (after the refrigerant recovery), the general controller 200 causes all the compressors 2a, 2
b is stopped for a predetermined time (for example, 1 minute) (step S
3).

In the conventional system, when the refrigerant recovery control is performed, a difference in height occurs in the refrigerant pressure between the outdoor unit and the indoor unit. In the present embodiment, however, this pressure imbalance is temporarily stopped in all the compressors 2a, 2b. It can be removed by After removing the pressure imbalance in this way, the general controller 200 operates the compressors 2a, 2b.
To restart normal cooling and heating simultaneous operation,
Normal air conditioning operation is performed according to the load of each room (step S4).

According to this embodiment, the compressors 2a, 2
When the operation of b is restarted to return to the normal operation according to the load of each room, for example, when the indoor unit 5b is cooled and the indoor units 5a and 5c are heated, the outdoor heat exchange is performed as described above. One switching valve 10a of the unit 3a is opened, the other switching valves 9a, 9b, 10b are closed, and one switching valve 15b of the indoor unit 5b for cooling is closed, the other switching valve 16b is opened, and heating is performed. One of the switching valves 15a, 15c of the indoor units 5a, 5c is opened and the other switching valve 16a, 16c is closed.

By doing so, one of the indoor heat exchangers 6a and 6c acts as a condenser, so that the two chambers are heated and the other indoor heat exchanger 6b acts as an evaporator, and the remaining one The room is cooled (step S4).

In short, according to this embodiment, since all the compressors 2a and 2b are temporarily stopped to remove the pressure imbalance and then the various switching valves are switched, the refrigerant which is offensive to these switching valves is used. No sound is produced.

The present invention is not limited to the above embodiment,
Various modifications can be made without departing from the scope of the claims. For example, the illustrated multi-room air conditioner includes two outdoor units and three indoor units, but according to the present invention, the number of each unit is not particularly limited.

[0045]

As described above, according to the invention of claim 1, the refrigerant recovery condition is satisfied, the refrigerant recovery control is performed for a predetermined time, and all the compressors are stopped for a predetermined time. Thereby, even if the refrigerant recovery control is performed, there is no difference in height between the refrigerant pressures between the indoor unit and the outdoor unit, and the pressure imbalance can be eliminated. Therefore, even if the compressor is operated again from the refrigerant recovery operation to shift to the normal cooling / heating simultaneous operation operation according to the load of each room, the generation of annoying refrigerant noise from the switching valve can be suppressed. .

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of a multi-room air conditioner of the present invention.

FIG. 2 is a diagram showing a procedure after a refrigerant recovery control in the multi-room cooling and heating apparatus of FIG.

[Explanation of symbols]

 1a, 1b Outdoor unit 2a, 2b Compressor 5a, 5b, 5c Indoor unit 11 Inter-unit piping 12 High pressure gas pipe 13 Low pressure gas pipe 14 Liquid pipe 200 General controller (means for transferring)

Claims (1)

[Claims] 1. A refrigeration cycle is formed by connecting a plurality of outdoor units equipped with a compressor and a plurality of indoor units with unit piping consisting of a high pressure gas pipe, a low pressure gas pipe and a liquid pipe, In a multi-chamber cooling and heating device capable of simultaneous cooling and heating operations, only the compressor is operated prior to the operation of this device to perform control for recovering the refrigerant in the refrigeration cycle to the outdoor unit, and performing full compression. A multi-room cooling and heating apparatus comprising means for shifting to a cooling or heating operation according to a load after the machine is stopped for a predetermined time.