JP2022047970A - Air conditioner and control method - Google Patents

Abstract

To provide a technology which can continue a heating operation without failing a compressor during a defrosting operation.SOLUTION: An outdoor machine comprises an outdoor expansion valve, an indoor heat exchanger, a four-way valve, an accumulator, a compressor, and a check valve. An indoor machine is connected to refrigerant piping which is the same as that of the outdoor machine in parallel therewith, and comprises an indoor heat exchanger, an indoor expansion valve and an indoor blower. When performing a defrosting operation for melting a frost which adheres to the outdoor heat exchanger of one outdoor machine, a control part performs a heating operation when a preset outdoor machine which is different from one outdoor machine does not perform a heating operation, makes the other outdoor machine which is different from one outdoor machine and the preset outdoor machine perform defrosting operation, and when the defrosting operations of the one outdoor machine and the other outdoor machine are finished, makes the other outdoor machine perform the heating operation for at least a constant time after a finish of the defrosting operations.SELECTED DRAWING: Figure 3

Description

Embodiments of the present invention relate to an air conditioner and a control method.

There is an air conditioner in which a plurality of outdoor units and a plurality of indoor units are connected. In such an air conditioner, when an outdoor unit that performs defrosting operation during heating operation and an outdoor unit that performs heating operation coexist, the high-pressure refrigerant discharged from the outdoor unit that performs heating operation performs defrosting operation. It flows into the compressor of the outdoor unit to be performed. Therefore, in general, the four-way valves of all the outdoor units are switched, and all the outdoor units perform the defrosting operation at the same time. In this case, since all the heat is used for the defrosting operation, the heating capacity is lowered and it becomes impossible to continue the heating operation.

Patent Document 1 discloses a technique for preventing the inflow of high-pressure refrigerant into the compressor of a defrosting outdoor unit by providing an opening / closing mechanism between the four-way valve and the compressor suction side and closing or adjusting the opening degree. ing. If the opening / closing mechanism is provided, not only the cost of the air conditioner as a whole increases, but also the efficiency of the refrigeration cycle decreases.

Japanese Unexamined Patent Publication No. 2010-48506

An object to be solved by the present invention is to provide an air conditioner and a control method capable of continuing the heating operation during the defrosting operation without damaging the compressor.

The air conditioner of the embodiment has a plurality of outdoor units, a plurality of indoor units, and a control unit. The outdoor unit includes an outdoor expansion valve, an outdoor heat exchanger, a four-way valve, an accumulator, a compressor, and a check valve for preventing the backflow of the refrigerant discharged from the compressor. The indoor unit is connected in parallel to the same refrigerant piping system as the outdoor unit, and includes an indoor heat exchanger, an indoor expansion valve for adjusting the amount of refrigerant flowing through the indoor heat exchanger, and an indoor blower. When the control unit performs a defrosting operation to melt the frost adhering to the outdoor heat exchanger of one outdoor unit, the control unit performs a heating operation when a predetermined outdoor unit different from the one outdoor unit is not performing the heating operation. When the defrosting operation of the one outdoor unit and another outdoor unit different from the predetermined outdoor unit is performed, and the defrosting operation of the one outdoor unit and the other outdoor unit is completed. After the defrosting operation is completed, the other outdoor unit is allowed to perform the heating operation for at least a certain period of time.

The figure which shows the structural example of the air conditioner of an embodiment. The block diagram which shows the specific example of the functional structure of the control part in an Embodiment. The flowchart which shows the specific example of the flow of the process which controls the defrost operation of the outside air processing heat exchanger during the heating operation of the air conditioner of embodiment. The flowchart which shows the specific example of the flow of the process which controls the defrost operation of the outside air processing heat exchanger during the heating operation of the air conditioner of embodiment.

Hereinafter, the air conditioner and the control method of the embodiment will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of the air conditioner 100 of the embodiment. The air conditioner 100 includes outdoor units 2, 3, 4, 5, indoor units 6, 7, 8, and a control unit 200. The outdoor units 2, 3, 4, 5 and the indoor units 6, 7, 8 are connected in parallel by the refrigerant pipe 90.

The outdoor units 2, 3, 4, and 5 of the present embodiment all have the same configuration.
The outdoor unit 2 includes a compressor 21, an accumulator 22, an outdoor heat exchanger 23, a four-way valve 25, an outdoor blower 26, and a temperature sensor 300A. The four-way valve 25 switches between cooling operation and heating operation. A check valve 29 is provided between the compressor 21 and the four-way valve 25. The check valve 29 prevents the backflow of the refrigerant. Further, a discharge pressure sensor 27 is provided between the compressor 21 and the four-way valve 25. The discharge pressure sensor 27 detects the discharge pressure of the refrigerant. A suction pressure sensor 28 is provided between the accumulator 22 and the four-way valve 25. The suction pressure sensor 28 detects the suction pressure of the refrigerant. The outdoor blower 26 sends air to the outdoor heat exchanger 23 in order to promote heat exchange of the refrigerant. The temperature sensor 300A detects the temperature of the outdoor heat exchanger 23 and outputs a signal indicating the detected temperature to the control unit 200. The outdoor heat exchanger 23 is connected to the refrigerant pipe 90 by the outdoor expansion valve 24.

The outdoor unit 3 includes a compressor 31, an accumulator 32, an outdoor heat exchanger 33, an outdoor expansion valve 34, a four-way valve 35, an outdoor blower 36, a discharge pressure sensor 37, a suction pressure sensor 38, a check valve 39, and a temperature sensor 300B. Be prepared.

The outdoor unit 4 includes a compressor 41, an accumulator 42, an outdoor heat exchanger 43, an outdoor expansion valve 44, a four-way valve 45, an outdoor blower 46, a discharge pressure sensor 47, a suction pressure sensor 48, a check valve 49, and a temperature sensor 300C. Be prepared.

The outdoor unit 5 includes a compressor 51, an accumulator 52, an outdoor heat exchanger 53, an outdoor expansion valve 54, a four-way valve 55, an outdoor blower 56, a discharge pressure sensor 57, a suction pressure sensor 58, a check valve 59, and a temperature sensor 300D. Be prepared.

The indoor unit 6 includes an indoor heat exchanger 61 and an indoor blower 63. The indoor blower 63 sends air to the indoor heat exchanger 61. The indoor heat exchanger 61 is connected to the refrigerant pipe 90 by the indoor expansion valve 62. The indoor unit 7 includes an indoor heat exchanger 71 and an indoor blower 73. The indoor blower 73 sends air to the indoor heat exchanger 71. The indoor heat exchanger 71 is connected to the refrigerant pipe 90 by the indoor expansion valve 72. The indoor blower 83 sends air to the indoor heat exchanger 81. The indoor heat exchanger 81 is connected to the refrigerant pipe 90 by the indoor expansion valve 82.

In the configuration shown in FIG. 1, four outdoor units are shown, but the number may be plural, and the number is not limited to four. Further, in the following description, when the temperature sensors 300A, 300B, 300C, and 300D are not distinguished from each other, they are referred to as the temperature sensor 300. Further, the outdoor expansion valves 24, 34, 44, 54 and the indoor expansion valves 62, 72, 82 can change the opening degree, and may be, for example, an electronic expansion valve (PMV: Pulse Motor Valve).

FIG. 2 is a block diagram showing a specific example of the functional configuration of the control unit 200 in the embodiment. The control unit 200 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a program. The control unit 200 functions as a device including a defrosting operation control unit 210, a heating operation control unit 220, a group setting unit 230, and an overall control unit 240 by executing a program.

The group information storage unit 250 is configured by using a storage device such as a magnetic hard disk device or a semiconductor storage device. For example, the group information storage unit 250 is configured by using a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory). The group information storage unit 250 stores information indicating a group of outdoor units. For example, the outdoor units 2 and 3 are stored in the group 1, and the outdoor units 4 and 5 are stored in the group 2. In this way, the group is predetermined.

The defrosting operation control unit 210 controls the entire defrosting operation such as the start and end of the defrosting operation in the outdoor units 2, 3, 4, and 5. The heating operation control unit 220 controls the overall heating operation such as the start and end of the heating operation in the outdoor units 2, 3, 4, and 5. The group setting unit sets the groups for the outdoor units 2, 3, 4, and 5 by the user's operation, and the set contents are stored in the group information storage unit 250. The overall control unit 240 controls the defrosting operation control unit 210, the heating operation control unit 220, and the group setting unit 230. Further, the overall control unit 240 is input with a signal indicating the temperature detected by the temperature sensors 300A, 300B, 300C, and 300D. That is, the overall control unit 240 can know the temperatures of the outdoor heat exchangers 23, 33, 43, and 53, respectively.

When the defrosting start condition is satisfied, the overall control unit 240 causes an outdoor unit equipped with an outdoor heat exchanger in which the temperature is detected to perform defrosting operation. If the defrosting end condition is satisfied after the defrosting operation is started, the overall control unit 240 ends the defrosting operation. The defrosting start condition in the present embodiment is that the temperature indicated by the input signal is equal to or lower than a predetermined threshold value A. The defrosting end condition is that the temperature indicated by the input signal becomes equal to or higher than the predetermined threshold value B after the defrosting operation is started.

All or part of each function of the control unit 200 described above may be realized by each outdoor unit 2, 3, 4, 5 provided and communicating with each other, or may be realized by ASIC (Application Specific Integrated Circuit) or PLD. It may be realized by using hardware such as (Programmable Logic Device) or FPGA (Field Programmable Gate Array). The program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a flexible disk, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, or a storage device such as a hard disk built in a computer system. The program may be transmitted over a telecommunication line.

3 and 4 are flowcharts showing a specific example of the flow of control processing when the air conditioner 1 of the embodiment performs the defrosting operation during the heating operation. As a group of outdoor units, as described above, the outdoor units 2 and 3 are group 1 (also referred to as "GR1"), and the outdoor units 4 and 5 are group 2 (also referred to as "GR2"). Is set. Further, it is sufficient that at least one of the outdoor units 2, 3, 4, and 5 is in the heating operation, and there may be an outdoor unit whose operation is stopped.

In the following description, the "heating operation machine" refers to an outdoor unit during heating operation. The “stop unit” refers to an outdoor unit that has been stopped. The "pre-defrosting operation machine" refers to an outdoor unit that was in the heating operation before the defrosting operation. "Pre-defrosting stop unit" indicates an outdoor unit that was stopped before any of the outdoor units started the defrosting operation. Therefore, even if the defrosting operation is not performed by itself, there is an outdoor unit that becomes a "pre-defrosting stop machine".

The overall control unit 240 determines whether or not the defrosting operation start condition of any of the outdoor units of GR1 is satisfied by the signal input from the temperature sensor 300 (step S101). If the defrosting operation start condition of any of the outdoor units of GR1 is not satisfied (step S101: NO), the overall control unit 240 proceeds to step S201 of FIG.

When the condition for starting the defrosting operation of any of the outdoor units of GR1 is satisfied (step S101: YES), the overall control unit 240 is connected to all the outdoor units 2 and 3 of GR1 by the defrosting operation control unit 210. The defrosting operation is started (step S102). Here, among the outdoor units of GR1, if there is an outdoor unit whose operation is stopped, the outdoor unit whose operation is stopped also starts the defrosting operation.

The overall control unit 240 determines whether or not there is a stop unit among the outdoor units 4 and 5 of the GR2 (step S103). When there is a stop machine (step S103: YES), the overall control unit 240 causes the stop machine to start the heating operation by the heating operation control unit 220 (step S104). If there is no stop (step S103: NO), the overall control unit 240 proceeds to step S105.

When the defrosting operation end condition is satisfied in the outdoor units 2 and 3 of the GR1 (step S105: YES), the overall control unit 240 causes the outdoor units 2 and 3 of the GR1 to end the defrosting operation by the defrosting operation control unit 210 (step S105: YES). Step S106). Here, the defrosting operation is terminated for each outdoor unit for which the defrosting operation termination condition is satisfied.

When the defrosting operation of all the outdoor units of GR1 is completed, the overall control unit 240 causes the pre-defrosting operation unit of GR1 to start the heating operation by the heating operation control unit 220 (step S107). The overall control unit 240 determines whether or not the GR1 has a pre-defrosting stop machine (step S108). If the GR1 does not have a pre-defrosting stop (step S108: NO), the overall control unit 240 proceeds to step S111.

When the GR1 has a pre-defrosting stop (step S108: YES), the overall control unit 240 causes the GR1 pre-defrosting stop to start the heating operation for a certain period of time by the heating operation control unit 220 (step S109). After a certain period of time has elapsed, the heating operation is stopped (step S110).

The overall control unit 240 determines whether or not the GR2 has a pre-defrosting stop (step S111). At the time of step S111, all the outdoor units of GR2 are in heating operation. If the GR2 does not have a pre-defrosting stop (step S111: NO), the overall control unit 240 proceeds to step S113. When the GR2 has a pre-defrosting stop machine (step S111: YES), the overall control unit 240 stops the heating operation of the pre-defrosting stop machine (step S112).

The overall control unit 240 determines whether or not to stop the operation (step S113). As an opportunity to stop the operation, for example, the user performs a stop operation with a remote controller (not shown) and receives an operation stop signal transmitted from the remote controller, the end time by the timer arrives, the transition to the sleep operation, etc. Can be mentioned.

When the operation is stopped (step S113: YES), the overall control unit 240 ends this process. If the operation is not stopped (step S113: NO), the overall control unit 240 proceeds to step S101.

Next, the process when the defrosting operation start condition of any of the outdoor units of GR1 is not satisfied in step S101 will be described with reference to FIG. The overall control unit 240 determines whether or not the defrosting operation start condition of any of the outdoor units of GR2 is satisfied by the signal input from the temperature sensor 300 (step S201). If the defrosting operation start condition of any of the outdoor units of GR2 is not satisfied (step S201: NO), the overall control unit 240 proceeds to step S113 of FIG.

When the condition for starting the defrosting operation of any of the outdoor units of GR2 is satisfied (step S201: YES), the overall control unit 240 is subjected to all the outdoor units 4 and 5 of GR2 by the defrosting operation control unit 210. The defrosting operation is started (step S202). Here, among the outdoor units of GR2, if there is an outdoor unit whose operation is stopped, the outdoor unit whose operation is stopped also starts the defrosting operation.

The overall control unit 240 determines whether or not there is a stop unit among the outdoor units 2 and 3 of GR1 (step S203). When there is a stop machine (step S203: YES), the overall control unit 240 causes the stop machine to start the heating operation by the heating operation control unit 220 (step S204). If there is no stop (step S203: NO), the overall control unit 240 proceeds to step S205.

When the defrosting operation end condition is satisfied in the outdoor units 4 and 5 of the GR2, the overall control unit 240 causes the outdoor units 4 and 5 of the GR2 to end the defrosting operation by the defrosting operation control unit 210 (step S205: YES). Step S206). Here, the defrosting operation is terminated for each outdoor unit for which the defrosting operation termination condition is satisfied.

When the defrosting operation of all the outdoor units of GR2 is completed, the overall control unit 240 causes the pre-defrosting operation unit of GR2 to start the heating operation by the heating operation control unit 220 (step S207). The overall control unit 240 determines whether or not the GR2 has a pre-defrost stop machine (step S208). If the GR2 does not have a pre-defrosting stop (step S208: NO), the overall control unit 240 proceeds to step S211.

If the GR2 has a pre-defrosting stop (step S208: YES), the overall control unit 240 causes the GR2 pre-defrosting stop to start the heating operation for a certain period of time by the heating operation control unit 220 (step S209). After a certain period of time has elapsed, the heating operation is stopped (step S210).

The overall control unit 240 determines whether or not the GR1 has a pre-defrosting stop (step S211). At the time of step S211 all the outdoor units of GR1 are in heating operation. If the GR1 does not have a pre-defrosting stop (step S211: NO), the overall control unit 240 proceeds to step S113 in FIG. If the GR1 has a pre-defrosting stop machine (step S211: YES), the overall control unit 240 stops the heating operation of the pre-defrosting stop machine (step S212), and proceeds to step S113 of FIG.

In the present embodiment, as shown in the above process, the pre-defrosting stop machine is allowed to perform the heating operation for a certain period of time after the defrosting operation is completed (step S109, step S209). The reason for this will be explained. During the defrosting operation, the check valves 29, 39, 49, 59 are open. Further, during the defrosting operation, the four-way valves 25, 35, 45, 55 are in the state during the cooling operation. Since it is difficult to close the check valves 29, 39, 49, 59 after the defrosting operation is completed, the check valves 29, 39, 49, 59 are not completely closed when the operation is terminated as it is after the defrosting operation is completed. The operation may end in the state. If another outdoor unit operates with the check valves 29, 39, 49, 59 not closed, the high-pressure refrigerant of the other outdoor unit may flow in even though the operation is stopped. In that case, a problem may occur.

Therefore, by performing the heating operation for a certain period of time after the defrosting operation is completed, the four-way valves 25, 35, 45, 55 are put into the state during the heating operation, and the check valves 29, 39, 49, 59 are made easy to close. Later, by stopping the operation, it is possible to suppress the occurrence of a problem. From this, the fixed time is the time until the check valves 29, 39, 49, 59 can be completely closed when the operation is stopped. The pre-defrosting operation machine starts the heating operation in steps S107 and 207, but even if an event occurs within a certain time after the start, for example, the operation is stopped by a user's operation, the heating operation is performed for at least a certain period of time. Let me do it.

As described above, in the present embodiment, when the defrosting operation of one outdoor unit (for example, outdoor unit 2) and the other outdoor unit (for example, outdoor unit 3) is completed, after the defrosting operation is completed, the other outdoor unit is used. Allow the heating operation to be performed for at least a certain period of time. For example, if the outdoor unit 3 is a stop unit, the heating operation is performed for a certain period of time after the defrosting operation is completed, and if the outdoor unit 3 is a pre-defrosting operation unit, the heating operation is started after the defrosting operation is completed (. Step S107). Therefore, after the defrosting operation is completed, the heating operation is performed for at least a certain period of time.

Further, in the present embodiment, the outdoor unit of a group different from the group of the outdoor unit performing the defrosting operation is allowed to perform the heating operation including the stop unit (step S104, step S204). That is, when the defrosting operation for melting the frost adhering to the outdoor heat exchanger of one outdoor unit is performed, the heating operation is performed when the predetermined outdoor unit different from the one outdoor unit is not performing the heating operation. .. As a result, as compared with the case where the four-way valves of all the outdoor units are switched and all the outdoor units perform the defrosting operation at the same time, it is possible to suppress the decrease in the heating capacity and continue the heating operation.

As described above, the air conditioner 100 in the present embodiment includes the outdoor expansion valves 24, 34, 44, 54, the outdoor heat exchangers 23, 33, 43, 53, and the four-way valves 25, 35, 45, 55. , Accumulators 22, 32, 42, 52, compressors 21, 31, 41, 51, and check valves 29, 39, 49, 59 for preventing the backflow of the refrigerant discharged from the compressor. A plurality of outdoor units 2, 3, 4, and 5 are provided. Further, the air conditioner 100 is connected in parallel to the same refrigerant piping 90 system as the outdoor units 2, 3, 4, and 5, and flows to the indoor heat exchangers 61, 71, 81 and the indoor heat exchanger. A plurality of indoor units including indoor expansion valves 62, 72, 82 for adjusting the amount of refrigerant and indoor blowers 63, 73, 83 are provided.

Further, the air conditioner 100 is different from the one outdoor unit (outdoor unit 2) in the case of performing a defrosting operation for melting the frost adhering to the outdoor heat exchanger 23 of one outdoor unit (for example, the outdoor unit 2). When the predetermined outdoor unit (outdoor units 4 and 5 of GR2) is not in the heating operation, the heating operation is performed, and the one outdoor unit (outdoor unit 2) and the predetermined outdoor unit (GR2) are operated. Another outdoor unit (outdoor unit 3) different from the outdoor units 4 and 5) is made to perform the defrosting operation, and the defrosting of the one outdoor unit (outdoor unit 2) and the other outdoor unit (outdoor unit 3). When the operation is completed, the control unit (overall control unit 240) for causing the other outdoor unit (outdoor unit 3) to perform the heating operation for at least a certain period of time is provided after the defrosting operation is completed.

According to the air conditioner 100, the heating operation can be continued during the defrosting operation without damaging the compressor, so that it is possible to provide an air conditioner that does not cause discomfort to the user.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

2, 3, 4, 5 ... Outdoor unit, 6, 7, 8 ... Indoor unit, 21, 31, 41, 51 ... Compressor, 22, 32, 42, 52 ... Accumulator, 23, 33, 43, 53 ... Outdoor Heat exchanger, 24, 34, 44, 54 ... Outdoor expansion valve, 25, 35, 45, 55 ... Four-way valve, 26, 36, 46, 56 ... Outdoor blower, 27, 37, 47, 57 ... Discharge pressure sensor, 28, 38, 48, 58 ... Suction pressure sensor, 29, 39, 49, 59 ... Check valve, 61, 71, 81 ... Indoor heat exchanger, 62, 72, 82 ... Indoor expansion valve, 63, 73, 83 ... ... Indoor blower, 90 ... Refrigerator piping, 100 ... Air conditioner, 200 ... Control unit, 210 ... Defrosting operation control unit, 220 ... Heating operation control unit, 230 ... Group setting unit, 240 ... Overall control unit, 250 ... Group information Storage unit, 300, 300A, 300B, 300C, 300D ... Temperature sensor

Claims (2)

A plurality of outdoor units including an outdoor expansion valve, an outdoor heat exchanger, a four-way valve, an accumulator, a compressor, and a check valve for preventing the backflow of the refrigerant discharged from the compressor.
A plurality of indoor units including an indoor heat exchanger, an indoor expansion valve for adjusting the amount of refrigerant flowing through the indoor heat exchanger, and an indoor blower while being connected in parallel to the same refrigerant piping system as the outdoor unit.
When performing a defrosting operation to melt the frost adhering to the outdoor heat exchanger of one outdoor unit, when a predetermined outdoor unit different from the one outdoor unit is not performing the heating operation, the heating operation is performed. When the defrosting operation is performed by the one outdoor unit and another outdoor unit different from the predetermined outdoor unit, and the defrosting operation of the one outdoor unit and the other outdoor unit is completed, the defrosting operation is completed. After the end of, the control unit that causes the other outdoor unit to perform heating operation for at least a certain period of time,
Air conditioner equipped with. A plurality of outdoor units including an outdoor expansion valve, an outdoor heat exchanger, a four-way valve, an accumulator, a compressor, and a check valve for preventing the backflow of the refrigerant discharged from the compressor, and the above. A plurality of indoor units equipped with an indoor heat exchanger, an indoor expansion valve for adjusting the amount of refrigerant flowing through the indoor heat exchanger, and an indoor blower while being connected in parallel to the same refrigerant piping system as the outdoor unit. It is a control method of the air conditioner provided.
When performing a defrosting operation to melt the frost adhering to the outdoor heat exchanger of one outdoor unit, when a predetermined outdoor unit different from the one outdoor unit is not performing the heating operation, the heating operation is performed. When the defrosting operation is performed by the one outdoor unit and another outdoor unit different from the predetermined outdoor unit, and the defrosting operation of the one outdoor unit and the other outdoor unit is completed, the defrosting operation is completed. A control method in which the other outdoor unit is allowed to perform heating operation for at least a certain period of time after the end of.

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