JPWO2020049605A1 - Air conditioner - Google Patents

Abstract

The air conditioner includes a plurality of indoor units each provided with a load side heat exchanger, a plurality of remote controllers corresponding to a plurality of indoor units, and a plurality of expansion valves corresponding to a plurality of load side heat exchangers. The control device has a control device for controlling the operation of a plurality of indoor units, and when the control device receives a capacity distribution correction signal indicating insufficient refrigerating capacity from one of the plurality of remote controllers, the capacity distribution correction is performed. Recognize the indoor unit corresponding to the remote controller of the signal transmission source as the special control target unit, increase the opening of the expansion valve corresponding to the special control target unit, and exclude the special control target unit from among multiple indoor units. The opening degree of the expansion valve corresponding to other indoor units is reduced.

Description

The present invention relates to an air conditioner having a plurality of indoor units and a control method thereof.

As an example of a conventional air conditioner, there is known a multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit and can be operated and controlled for each indoor unit. There are various demands for air conditioners around the world. In recent years, the demand for cooling has been increasing in warm regions such as Asia, and an inexpensive multi-type air conditioner for cooling is required.

In a multi-type air conditioner, the length of the extension pipe connecting the outdoor unit and the indoor unit may not be uniform between the indoor units. In this case, in the indoor unit connected to the long extension pipe, the refrigerant pressure loss increases due to the pipe length, so that the refrigerant circulation amount decreases, and the refrigerating capacity tends to decrease as compared with other indoor units.

Therefore, if indoor units of the same model are installed in each of a plurality of rooms without considering the decrease in capacity due to the pipe length, and the multiple indoor units perform cooling in parallel, the speed at which the temperature drops differs among the multiple rooms. .. For example, in some rooms the room temperature drops quickly to the set temperature, while in other rooms it takes time for the room temperature to drop to the set temperature.

For the purpose of solving this problem, the user can operate not only the indoor unit of the own room but also the indoor unit of another room while monitoring the status of the indoor unit of the own room and the indoor unit of the other room. (See, for example, Patent Document 1).

In the air conditioner disclosed in Patent Document 1, the user confirms the environmental information including the temperature information of the other room and the operating status with the operating device, and the indoor unit in his / her room and the indoor unit in the other room are operated as the operation target. To operate the indoor unit by switching between.

Further, in Patent Document 2, a pipe length setting means for setting the content of the length of the pipe connecting a plurality of indoor units is provided in the branch unit, and the branch unit is branched according to the content set in the pipe length setting means. An air conditioner for correcting the opening degree of an electric expansion valve provided in a unit is disclosed.

Japanese Unexamined Patent Publication No. 09-210433 Japanese Unexamined Patent Publication No. 07-180884

However, in the air conditioner disclosed in Patent Document 1, the user confirms the environmental information of the own room and the other room, and when the temperature of the own room is higher than the temperature of the other room, the indoor unit of the other room. It is necessary to operate the operation device so as to distribute a part of the refrigerating capacity of the room to the indoor units in the room.

Further, in the air conditioner disclosed in Patent Document 2, when a plurality of indoor units are operated in parallel, the user sets the pipe length in order to increase the distribution amount of the refrigerating capacity to the indoor unit whose refrigerating capacity is insufficient with respect to the load. The contents of the pipe length must be set in advance for the means. Further, if the content of the pipe length set in the pipe length setting means is incorrect, the user needs to reset the setting in the pipe length setting means.

The present invention has been made to solve the above problems, and the refrigerating capacity is insufficient even if the user does not perform an operation to equalize the refrigerating capacity of a plurality of indoor units operating in parallel. It provides an air conditioner that automatically improves the refrigerating capacity of the machine and a control method thereof.

The air conditioner according to the present invention corresponds to a plurality of indoor units each provided with a load side heat exchanger, a plurality of remote controllers corresponding to the plurality of indoor units, and a plurality of the load side heat exchangers. It has a plurality of expansion valves and a control device for controlling the operation of the plurality of indoor units, and the control device has an ability to indicate insufficient refrigerating capacity from one of the plurality of remote controllers. When the distribution correction signal is received, the indoor unit corresponding to the remote controller that is the source of the capacity distribution correction signal is recognized as the special control target unit, and the opening degree of the expansion valve corresponding to the special control target unit is increased. Among the plurality of indoor units, the opening degree of the expansion valve corresponding to the other indoor units other than the special control target unit is reduced.

The control method of the air conditioner according to the present invention is an air conditioner having a plurality of indoor units each provided with a load side heat exchanger and a plurality of expansion valves corresponding to the plurality of load side heat exchangers. When a capacity distribution correction signal indicating insufficient refrigerating capacity is received from one of the plurality of remote controllers corresponding to the plurality of indoor units, the source of the capacity distribution correction signal The step of recognizing the indoor unit corresponding to the remote controller as the special control target machine, and increasing the opening degree of the expansion valve of the special control target machine, among the plurality of indoor units, other than the special control target machine. It has a step of reducing the opening degree of the expansion valve of the indoor unit.

According to the present invention, the opening degree of each expansion valve is adjusted, and the amount of refrigerant circulating in the indoor unit whose refrigerating capacity is insufficient with respect to the load increases. Therefore, even if the user does not operate the remote controller to equalize the refrigerating capacity, the refrigerating capacity of the indoor unit whose refrigerating capacity is insufficient can be maintained while maintaining the stability of the operating state of a plurality of indoor units. Can be improved.

It is a refrigerant circuit diagram which shows one structural example of the air conditioner which concerns on Embodiment 1 of this invention. It is a block diagram which shows one configuration example of the control device shown in FIG. It is a block diagram which shows another configuration example of the control device shown in FIG. It is a flowchart which shows the operation procedure of the air conditioner shown in FIG. It is a figure which shows an example of the operation procedure of step S1 shown in FIG. It is a figure which shows an example of the operation procedure of step S5 shown in FIG. It is a figure which shows an example of the flow rate characteristic data of the expansion valve shown in FIG. It is a figure which shows an example of the operation procedure of step S6 shown in FIG. It is a figure which shows an example of the operation procedure of step S61 shown in FIG. It is a figure which shows an example of the operation procedure of step S62 shown in FIG. It is a figure which shows an example of the operation procedure of step S63 shown in FIG. It is a figure which shows an example of the operation procedure of step S64 shown in FIG. It is a figure which shows an example of the operation of step S65 shown in FIG. It is a figure which shows an example of the operation of step S67 shown in FIG. It is a flow chart which shows the operation procedure of the modification 1 about the control method of the air conditioner shown in FIG. It is a figure which shows an example of the operation of step S10 shown in FIG.

Embodiment 1.
The configuration of the air conditioner according to the first embodiment will be described. FIG. 1 is a refrigerant circuit diagram showing a configuration example of an air conditioner according to a first embodiment of the present invention. The air conditioner 100 includes an outdoor unit 50 and a plurality of indoor units 60a to 60d. The indoor units 60a to 60d are connected in parallel to the outdoor unit 50. The indoor unit 60a is connected to the outdoor unit 50 via an extension pipe 80a through which the refrigerant flows. The indoor unit 60b is connected to the outdoor unit 50 via an extension pipe 80b. The indoor unit 60c is connected to the outdoor unit 50 via an extension pipe 80c. The indoor unit 60d is connected to the outdoor unit 50 via an extension pipe 80d. Since the indoor units 60a to 60d have the same configuration, the configuration of the indoor unit 60a will be described below, and the description of the configuration of the indoor units 60b to 60d will be omitted.

The outdoor unit 50 includes a compressor 1 that compresses and discharges the refrigerant, a four-way valve 2 that switches the flow direction of the refrigerant, a heat source side heat exchanger 3 that is a heat exchanger in which the refrigerant exchanges heat with the outside air, and a refrigerant. It has expansion valves 6a to 6d for reducing the pressure of the air conditioner and a control device 30 for controlling the operation of the air conditioner 100. The expansion valves 6a to 6d are provided corresponding to the indoor units 60a to 60d. As shown in FIG. 1, the outdoor unit 50 may have an outdoor fan 4 which is a blower that blows air to the heat source side heat exchanger 3. An outdoor fan motor 5 that rotationally drives the outdoor fan 4 is connected to the outdoor fan 4.

Further, as shown in FIG. 1, a liquid side valve 10 is provided in a refrigerant pipe connecting the heat source side heat exchanger 3 and the expansion valves 6a to 6d. A gas side valve 11 is provided in the refrigerant pipe connecting the four-way valve 2 and the indoor units 60a to 60d. A liquid reservoir 19 for holding excess refrigerant is provided in a refrigerant pipe connected to a refrigerant suction port of the compressor 1.

The indoor unit 60a has a load-side heat exchanger 7a, which is a heat exchanger in which the refrigerant exchanges heat with the indoor air. As shown in FIG. 1, the indoor unit 60a may have an indoor fan 8a which is a blower that blows air to the load side heat exchanger 7a. An indoor fan motor 9a that rotationally drives the indoor fan 8a is connected to the indoor fan 8a. The compressor 1, the heat source side heat exchanger 3, the expansion valves 6a to 6d, and the load side heat exchangers 7a to 7d are connected by a refrigerant pipe to form a refrigerant circuit 40 in which the refrigerant circulates. The indoor fan motors 9b to 9d are provided corresponding to the indoor fans 8b to 8d.

As shown in FIG. 1, the outdoor unit 50 is provided with an outside air temperature detecting means 14 for detecting the outside air temperature. A discharge temperature detecting means 12 for detecting the discharge temperature of the refrigerant is provided on the refrigerant discharge side of the compressor 1. The heat source side heat exchanger 3 includes a heat source side saturation temperature detecting means 13 for detecting the refrigerant saturation temperature in the heat source side heat exchanger 3 and a heat source side temperature detecting means 15 for detecting the refrigerant temperature of the heat source side heat exchanger 3. Is provided.

The indoor unit 60a is provided with a room temperature detecting means 18a for detecting the temperature of the air in the room. The load-side heat exchanger 7a includes a load-side saturation temperature detecting means 16a that detects the refrigerant saturation temperature in the load-side heat exchanger 7a, and a load-side temperature detecting means 17a that detects the refrigerant temperature of the load-side heat exchanger 7a. Is provided.

The compressor 1 is, for example, an inverter type compressor capable of changing the frequency. The expansion valves 6a to 6d have a configuration capable of controlling the opening degree. Expansion valves 6a to 6d are, for example, electronic expansion valves. In the first embodiment, the case where the expansion valves 6a to 6d are electronic expansion valves will be described. The electronic expansion valve has a stepping motor that rotates at an angle of rotation corresponding to the number of input pulses, and adjusts the opening degree according to the rotation of the stepping motor. The load-side heat exchangers 7a to 7d and the heat-source-side heat exchanger 3 are, for example, fin-and-tube heat exchangers. The four-way valve 2 sets the flow path shown by the solid line in FIG. 1 when the air conditioner 100 is in the cooling operation, and switches to the flow path shown by the broken line in FIG. 1 when the air conditioner 100 is in the heating operation.

FIG. 2 is a block diagram showing a configuration example of the control device shown in FIG. As shown in FIG. 1, the control device 30 has a memory 31 for storing a program and a CPU (Central Processing Unit) 32 for executing processing according to the program. As shown in FIG. 2, the control device 30 includes indoor unit control means 20a to 20d and outdoor unit control means 21 for controlling the outdoor unit 50. The indoor unit control means 20a controls the indoor unit 60a. The indoor unit control means 20b controls the indoor unit 60b. The indoor unit control means 20c controls the indoor unit 60c. The indoor unit control means 20d controls the indoor unit 60d. When the CPU 32 executes the program, the indoor unit control means 20a to 20d and the outdoor unit control means 21 are configured.

A plurality of remote controllers 70a to 70d operated by the user are provided corresponding to the plurality of indoor units 60a to 60d. The remote controller 70a and the indoor unit control means 20a communicate by wire and / or wireless communication. For example, when a photo sensor (not shown) is provided in the indoor unit 60a, the photo sensor and the remote controller 70a may communicate with each other by infrared rays, and the photo sensor and the indoor unit control means 20a may communicate with each other by wire.

When at least one information of the operation mode, the operation start / stop instruction, and the set temperature is input, the remote controller 70a transmits the operation information including the input information to the indoor unit control means 20a. To do. The indoor unit control means 20a transfers the operation information received from the remote controller 70a to the outdoor unit control means 21, and activates the indoor fan 8a when the operation information includes an instruction to start operation. Since the remote controllers 70b to 70d have the same configuration as the remote controllers 70a and the indoor unit control means 20b to 20d have the same configuration as the indoor unit control means 20a, detailed description of these configurations will be omitted.

In the outdoor unit control means 21, detection values are input from each temperature detecting means of the heat source side saturation temperature detecting means 13, the outside air temperature detecting means 14, and the heat source side temperature detecting means 15. In the outdoor unit control means 21, detection values are input from the temperature detection means of the load side saturation temperature detection means 16a to 16d, the load side temperature detection means 17a to 17d, and the room temperature detection means 18a to 18d. The outdoor unit control means 21 controls the four-way valve 2 according to the operation mode included in the operation information received from the indoor unit control means 20a to 20d. Further, the outdoor unit control means 21 opens the operation frequency of the compressor 1 and the expansion valves 6a to 6d based on the operation information received from the indoor unit control means 20a to 20d and the detection values input from various temperature detection means. Control the degree. Details of the operation of the outdoor unit control means 21 will be described later.

Although FIG. 1 shows a configuration when the control device 30 is provided in the outdoor unit 50, the installation location of the control device 30 is not limited to the outdoor unit 50. For example, the indoor unit control means 20a is provided in the indoor unit 60a, the indoor unit control means 20b is provided in the indoor unit 60b, the indoor unit control means 20c is provided in the indoor unit 60c, and the indoor unit control means 20d is provided in the indoor unit 60d. It may be provided in. FIG. 3 is a block diagram showing another configuration example of the control device shown in FIG. In FIG. 3, the indoor unit control means 20b and 20c shown in FIG. 2 and the configuration connected to these control means are omitted from the figure. The control device 30 shown in FIG. 3 also has indoor unit control means 20b and 20c.

In the case of the configuration shown in FIG. 3, the indoor unit control means 20a receives detection values from the load side saturation temperature detection means 16a, the load side temperature detection means 17a, and the room temperature detection means 18a. The indoor unit control means 20a may transfer the operation information including the detection values received from these detection means to the outdoor unit control means 21, and the operation information including the temperature difference calculated from the received detection values may be transferred to the outdoor unit control means 21. You may transfer to. Since the indoor unit control means 20b to 20d have the same configuration as the indoor unit control means 20a, the description thereof will be omitted. In the case of the configuration shown in FIG. 3, the CPU 32 and the memory 31 shown in FIG. 1 may be provided in each of the indoor units 60a to 60d.

Further, FIG. 1 shows a configuration in which the expansion valves 6a to 6d are provided in the outdoor unit 50, but the expansion valves 6a to 6d may not be provided in the outdoor unit 50. For example, even if the expansion valve 6a is provided in the indoor unit 60a, the expansion valve 6b is provided in the indoor unit 60b, the expansion valve 6c is provided in the indoor unit 60c, and the expansion valve 6d is provided in the indoor unit 60d. Good. Further, in the first embodiment, the case where the load side saturation temperature detecting means 16a to 16d for detecting the refrigerant saturation temperature and the heat source side saturation temperature detecting means 13 are provided will be described, but instead of these temperature detecting means. May be provided with a pressure detecting means. In this case, the outdoor unit control means 21 may obtain the refrigerant saturation temperature from the detection value of the pressure detecting means.

Next, the flow of the refrigerant when the air conditioner 100 shown in FIG. 1 performs a cooling operation will be described. For the sake of simplicity, the case where the indoor unit 60a performs the cooling operation will be described here. The liquid side valve 10 and the gas side valve 11 are in the open state. The outdoor unit control means 21 sets the flow path of the four-way valve 2 so that the refrigerant discharged from the compressor 1 flows into the heat source side heat exchanger 3. The low-temperature and low-pressure refrigerant is compressed by the compressor 1, and the high-temperature and high-pressure gas refrigerant is discharged from the compressor 1. The gas refrigerant discharged from the compressor 1 flows into the heat source side heat exchanger 3 via the four-way valve 2. The refrigerant that has flowed into the heat source side heat exchanger 3 is condensed and liquefied by radiating heat from the outside air supplied from the outdoor fan 4 in the heat source side heat exchanger 3, and becomes a high-pressure liquid refrigerant.

The liquid refrigerant flowing out of the heat source side heat exchanger 3 is depressurized by the expansion valve 6a, and is in a low-pressure gas-liquid two-phase state. The gas-liquid two-phase state refrigerant flows into the load side heat exchanger 7a. In the load side heat exchanger 7a, the refrigerant becomes a low-pressure gas refrigerant by absorbing heat from the indoor air supplied by the indoor fan 8a. When the refrigerant absorbs heat from the indoor air, the indoor air in which the indoor unit 60a is installed is cooled, and the room temperature is lowered. After that, the refrigerant returns to the compressor 1 via the four-way valve 2 and the liquid reservoir 19. While the air conditioner 100 performs the cooling operation, the refrigerant discharged from the compressor 1 flows through the heat source side heat exchanger 3, the expansion valve 6a, and the load side heat exchanger 7a in this order, and then is sucked into the compressor 1. The cycle until is repeated.

In the first embodiment, detailed description of the case where the air conditioner 100 performs the heating operation will be omitted. When the air conditioner 100 performs the heating operation, the flow direction of the refrigerant in the refrigerant circuit 40 is opposite to that in the cooling operation, and the load side heat exchangers 7a to 7d function as condensers to exchange heat on the heat source side. The vessel 3 functions as an evaporator.

Next, the refrigeration cycle control performed by the air conditioner 100 shown in FIG. 1 will be described. First, a case will be described in which one of the plurality of indoor units 60a to 60d is operated. As a specific example, a case where the indoor unit 60a is operated for cooling will be described.

A user in a room where the indoor unit 60a is installed operates the remote controller 70a to input a cooling operation, an instruction to start the operation, and a set temperature. The indoor unit control means 20a activates the indoor fan 8a according to an instruction to start operation. The indoor unit control means 20a calculates the temperature difference Tdr between the room temperature and the set temperature detected by the room temperature detecting means 18a. The indoor unit control means 20a transmits operation information including a set temperature, a cooling operation, a temperature difference Tdr, and an instruction to start the operation to the outdoor unit control means 21. When the outdoor unit control means 21 receives the operation information from the indoor unit control means 20a, the outdoor unit control means 21 sets the flow path of the four-way valve 2 according to the operation mode information included in the operation information. Further, the outdoor unit control means 21 determines the operation frequency of the compressor 1 based on the information of the temperature difference Tdr included in the operation information. For example, when the room temperature detected by the room temperature detecting means 18a is 27 ° C. and the set temperature is 23 ° C., the outdoor unit controlling means 21 sets the operating frequency of the compressor 1 to 70 Hz. The outdoor unit control means 21 activates the compressor 1 and the outdoor fan 4 after determining the operating frequency of the compressor 1.

In the case of cooling operation, the refrigerant saturation temperature detected by the load-side saturation temperature detecting means 16a corresponds to the evaporation temperature. The indoor unit control means 20a transmits operation information including the detected refrigerant saturation temperature and the determined target evaporation temperature to the outdoor unit control means 21. The outdoor unit control means 21 reads out the refrigerant saturation temperature and the target evaporation temperature from the operation information received from the indoor unit control means 20a, and controls the operating frequency of the compressor 1 so that the refrigerant saturation temperature becomes the target evaporation temperature. For example, when the target evaporation temperature is 9 ° C. and the detection value of the load-side saturation temperature detection means 16a is 13 ° C., the outdoor unit control means 21 of the compressor 1 so that the detection value becomes the target evaporation temperature. Increase the operating frequency.

Further, the outdoor unit control means 21 controls the opening degree of the expansion valve 6a so that the discharge temperature detected by the discharge temperature detecting means 12 reaches a determined target discharge temperature. For example, when the target discharge temperature is 80 ° C. and the detection value of the discharge temperature detection means 12 is 75 ° C., the outdoor unit control means 21 opens the expansion valve 6a so that the detected value reaches the target discharge temperature. Operates in the closing direction. When the indoor unit to be operated is other than the indoor unit 60a, the outdoor unit control means 21 performs the above-mentioned expansion valve control on the expansion valve corresponding to the indoor unit in operation.

Subsequently, the refrigeration cycle control performed by the air conditioner 100 when two or more indoor units among the plurality of indoor units 60a to 60d are operated in parallel will be described. When two or more indoor units operate in parallel, the air conditioner 100 performs capacity distribution control for distributing the refrigerating capacity to the two or more indoor units.

Each indoor unit control means of two or more indoor units to be operated transmits operation information including a target evaporation temperature to the outdoor unit control means 21. The outdoor unit control means 21 determines a target evaporation temperature to be used for capacity distribution control based on two or more target evaporation temperatures received from two or more indoor unit control means, and the compressor 1 is determined according to the determined target evaporation temperature. Determine the operating frequency of. For example, the outdoor unit control means 21 selects one of the two or more target evaporation temperatures that requires the most refrigerating capacity, and uses the selected target evaporation temperature to set the operating frequency of the compressor 1. Control. Further, the outdoor unit control means 21 controls the opening degree of two or more expansion valves corresponding to the two or more indoor units to be operated so that the discharge temperature detected by the discharge temperature detecting means 12 approaches the target discharge temperature. To do. The target discharge temperature is calculated from, for example, two or more target evaporation temperatures according to a determined formula. When the two or more indoor units to be operated are different, the outdoor unit control means 21 switches the target evaporation temperature according to the characteristics of the two or more indoor units to be operated.

Here, the control device 30 performs the above-mentioned capacity distribution control for two or more indoor units that are operated for cooling without considering the non-uniformity of the refrigerating capacity due to the difference in the length of the extension pipe. Consider the case of doing. As a specific example, it is assumed that four indoor units 60a to 60d perform a cooling operation, and the extension pipe 80d connected to the indoor unit 60d is longer than the extension pipes 80a to 80c of the other indoor units 60a to 60c.

Each of the indoor unit control means 20a to 20d transmits the operation information including the target evaporation temperature to the outdoor unit control means 21. The outdoor unit control means 21 determines the target evaporation temperature based on the four target evaporation temperatures received from the indoor unit control means 20a to 20d, and determines the operating frequency of the compressor 1 according to the determined target evaporation temperature. Further, the outdoor unit control means 21 controls the opening degree of the expansion valves 6a to 6d so that the discharge temperature detected by the discharge temperature detecting means 12 approaches the target discharge temperature. For example, when the target evaporation temperature is 11 ° C. and the target discharge temperature is 80 ° C., the operating frequency of the compressor 1 is 70 Hz, and the number of pulses corresponding to the opening degrees of the expansion valves 6a to 6d is 100. It becomes a pulse.

Even if the refrigeration cycle becomes stable after the air conditioner 100 starts the capacity distribution control, the refrigerating capacity of the indoor unit 60d is lower than that of the other indoor units 60a to 60c operating in parallel with the indoor unit 60d. .. The reason is that the indoor unit 60d connected to the long extension pipe 80d has a large refrigerant pressure loss and a small refrigerant circulation amount as compared with the other indoor units 60a to 60c. In this case, the user of each room in which the indoor units 60a to 60c are installed realizes that the indoor temperature drops, but the user in the room in which the indoor unit 60d is installed does not have the indoor temperature as low as expected. I sometimes feel it.

Under such a situation, the air conditioner 100 of the first embodiment suppresses the bias of the refrigerating capacity among the indoor units by performing the capacity distribution correction control for correcting the distribution of the refrigerating capacity. The capacity distribution correction control performed by the air conditioner 100 shown in FIG. 1 will be described. It is assumed that the extension pipe 80d connected to the indoor unit 60d is longer than the extension pipes 80a to 80c of the other indoor units 60a to 60c.

FIG. 4 is a flowchart showing an operating procedure of the air conditioner shown in FIG. A user in at least one of the four rooms in which the indoor units 60a to 60d are installed operates the remote controller 70k to input an instruction to start the cooling operation. k is an identification code for distinguishing indoor units. Specifically, k is an arbitrary identification code of a to d. When the outdoor unit control means 21 receives the operation information from the indoor unit control means 20k, the outdoor unit control means 21 determines the operation frequency of the compressor 1 and the opening degree of the expansion valve 6k based on the received operation information, and determines the operation frequency of the compressor 1 and the opening degree of the expansion valve 6k. Is activated to start the cooling operation (step S1).

An example of the operation procedure of step S1 shown in FIG. 4 will be described. FIG. 5 is a diagram showing an example of the operation procedure of step S1 shown in FIG. Here, the case where the indoor unit 60a performs the cooling operation will be described. When the indoor unit control means 20a receives a signal indicating the start of the cooling operation from the remote controller 70a (step S11), the indoor unit control means 20a activates the indoor fan motor 9a to rotate the indoor fan 8a (step S12). Further, the indoor unit control means 20a transmits operation information including an instruction to start the cooling operation to the outdoor unit control means 21 (step S13). When the outdoor unit control means 21 receives the operation information from the indoor unit control means 20a, the outdoor unit control means 21 sets the flow path of the four-way valve 2 and the operation frequency of the compressor 1 based on the operation information, and causes the compressor 1 and the outdoor fan 4 to operate. to start. In this way, the air conditioner 100 starts operation. After that, the control device 30 shifts to step S2.

In step S2 shown in FIG. 4, the outdoor unit control means 21 determines how many indoor units are in operation. When the number of indoor units to be operated is one, the outdoor unit control means 21 starts refrigerating cycle control of one indoor unit and returns to step S2. On the other hand, when the number of indoor units to be operated is two or more, the outdoor unit control means 21 performs capacity distribution control for the two or more indoor units (step S3). In the following, it is assumed that the indoor units 60a to 60d perform the cooling operation. The outdoor unit control means 21 determines the target evaporation temperature based on the four target evaporation temperatures received from the indoor unit control means 20a to 20d, and determines the operating frequency of the compressor 1 according to the determined target evaporation temperature. Further, the outdoor unit control means 21 controls the opening degree of the expansion valves 6a to 6d so that the discharge temperature detected by the discharge temperature detecting means 12 approaches the target discharge temperature.

Subsequently, the outdoor unit control means 21 determines whether or not to receive the capacity distribution correction signal from the remote controllers 70a to 70d via the indoor unit control means 20a to 20d (step S4). Here, an example of determining the capacity distribution correction signal will be described. Even if the cooling operation of the indoor units 60a to 60d becomes stable, the user in the room where the indoor unit 60d is installed feels that the temperature inside the room does not become as low as expected due to the difference in the length of the extension pipe. .. At this time, it is considered that the user performs an operation of lowering the set temperature on the remote controller 70d. The user operates the remote controller 70d and inputs an instruction to lower the set temperature by the temperature ΔTs. When the indoor unit control means 20d receives an update signal from the remote controller 70d including an instruction to lower the set temperature by the temperature ΔTs, the indoor unit control means 20d transfers the update signal to the outdoor unit control means 21. When the outdoor unit control means 21 receives an instruction to lower the set temperature from the indoor unit control means 20d but does not receive an instruction to lower the set temperature from the other indoor unit control means 20a to 20c, the refrigerating capacity distribution control is corrected. Is judged to be necessary. In this case, the update signal transmitted by the remote controller 70d to the outdoor unit control means 21 via the indoor unit control means 20d functions as a capacity distribution correction signal.

Further, when the outdoor unit control means 21 receives the update signal from the indoor unit control means 20d, the outdoor unit control means 21 compares the four temperature difference Tdrs of the indoor units 60a to 60d, and whether or not the received update signal is the capacity distribution correction signal. May be determined. For example, when the set temperatures of the indoor units 60a to 60d are the same and the temperature difference Tdr of the indoor unit 60d is larger than the temperature difference Tdr of the other indoor units 60a to 60c, the outdoor unit control means 21 is the indoor unit control means. The update signal received from 20d is determined to be the capacity distribution correction signal.

The remote controllers 70a to 70d may be provided with a capacity correction button for inputting a capacity distribution correction instruction. In this case, when the remote controller 70d notifies that the capacity correction button has been pressed, the indoor unit control means 20d transmits a capacity distribution correction signal to the outdoor unit control means 21.

In step S2, when the outdoor unit control means 21 receives the capacity distribution correction signal from the indoor unit control means 20d, the outdoor unit control means 21 recognizes the indoor unit 60d as a special control target machine for a certain period of time tp1 (step S5). An example of the operation procedure of step S5 shown in FIG. 4 will be described. FIG. 6 is a diagram showing an example of the operation procedure of step S5 shown in FIG. The outdoor unit control means 21 recognizes the indoor unit 60d corresponding to the indoor unit control means 20d of the transmission source of the capacity distribution correction signal as the special control target unit (step S51). The outdoor unit control means 21 recognizes the other indoor units 60a to 60c other than the special control target unit among the operating indoor units 60a to 60d as non-special control target units (step S52). The outdoor unit control means 21 shifts to step S6 after the process of step S52.

In step S6 shown in FIG. 4, the outdoor unit control means 21 operates the expansion valve 6d in the direction of opening from the current opening degree. Further, the outdoor unit control means 21 controls the opening degree of the expansion valves 6a to 6c of the indoor units 60a to 60c other than the indoor unit 60d to be specially controlled among the operating indoor units (in the direction of closing). Step S6). For example, the outdoor unit control means 21 opens the opening degree of the expansion valve 6d of the indoor unit 60d to be specially controlled by 20 pulses, and closes the expansion valves 6a to 6c of the other indoor units 60a to 60c by 10 pulses. The outdoor unit control means 21 may open the opening degree of the expansion valve 6d by 20 pulses and close the expansion valves 6a to 6c by 10 pulses at a constant cycle tp2, for example, every 120 seconds.

According to the operation procedure shown in FIG. 4, due to the length of the extension pipe 80d, the amount of refrigerant circulating in the indoor unit 60d, which has insufficient refrigerating capacity with respect to the load, increases. As a result, the refrigerating capacity can be adjusted so that the refrigerating capacity of the indoor units 60d, which lacks the refrigerating capacity, is improved while maintaining the stability of the operating state of the plurality of indoor units 60a to 60d.

In step S6 shown in FIG. 4, the case where the expansion valves 6d are opened at the determined fixed opening and the expansion valves 6a to 6c are closed at the determined fixed opening has been described, but the expansion valves 6a to 6d are opened. Degree control is not limited to this case. The opening degree of the expansion valves 6a to 6d may be controlled so that the combined Cv value of the expansion valves 6a to 6d becomes constant. A specific example will be described. The outdoor unit control means 21 calculates the synthetic Cv value required for the refrigerating capacity of the entire air conditioner 100 from the relationship between the opening degree and the flow rate obtained from the flow rate characteristic data of the expansion valves 6a to 6d. Then, the outdoor unit control means 21 maintains the synthetic Cv value required for the refrigerating capacity of the entire air conditioner 100 so that the synthetic Cv value obtained from the current opening degree of the expansion valves 6a to 6d is maintained. The opening degree of is corrected.

For example, it is assumed that the operation of each indoor unit of the indoor units 60a to 60d is stable in a state where the number of pulses of the opening degree of all the expansion valves 6a to 6d is 100 pulses. It is assumed that the outdoor unit control means 21 opens the opening degree of the expansion valve 6d of the indoor unit 60d, which is the special control target machine, by 20 pulses according to the capacity distribution correction control. In this case, since the flow rate of the expansion valve 6d increases, the Cv value of the expansion valve 6d increases, and the combined Cv value also increases. On the other hand, in the outdoor unit control means 21, the combined Cv value of the expansion valves 6a to 6c of the other indoor units 60a to 60c during operation is equal to the combined Cv value before correcting the opening degree of the expansion valves 6a to 6c. Therefore, the correction opening amount is determined from the flow rate characteristic data. For example, when the outdoor unit control means 21 determines that the number of pulses of the correction opening amount is 8 pulses, the expansion valves 6a to 6c are closed by 8 pulses.

FIG. 7 is a diagram showing an example of the flow rate characteristic data of the expansion valve shown in FIG. The expansion valve showing the flow rate characteristic data in FIG. 7 may be any of the expansion valves 6a to 6d. The vertical axis shown in FIG. 7 is the Cv value, and the horizontal axis is the opening pulse indicating the number of pulses corresponding to the opening. Pmax means that the opening degree of the expansion valve is the maximum value, and Pmin means that the opening degree of the expansion valve is the minimum value. FIG. 7 shows that the Cv value when the opening degree Pt1 is Cv1 and the Cv value when the opening degree Pt2 is Cv2.

Further, in the capacity distribution correction control, it is desirable to correct the opening degree of the expansion valves 6a to 6d so as to satisfy the condition of avoiding dew skipping. The outdoor unit control means 21 adjusts the opening degree of the expansion valve 6k so that the refrigerant temperature T17k and the refrigerant saturation temperature T16k are higher than the determined lower limit threshold value Tmin in the load side heat exchanger 7k of the indoor unit 60k during operation. to correct. Further, the outdoor unit control means 21 corrects the opening degree of the expansion valve 6k so that the temperature difference ΔTek between the refrigerant temperature T17k and the refrigerant saturation temperature T16k becomes equal to or higher than the determined dry tolerance threshold T1.

Specifically, the outdoor unit control means 21 sets the refrigerant temperature T17a detected by the load-side temperature detecting means 17a and the refrigerant saturation temperature T16a detected by the load-side saturation temperature detecting means 16a in the indoor unit 60a during operation. Obtained from the machine control means 20a. Then, the outdoor unit control means 21 calculates and stores the temperature difference ΔTea between the refrigerant temperature T17a and the refrigerant saturation temperature T16a. Further, the outdoor unit control means 21 calculates and stores the temperature difference ΔTeb to ΔTed for the indoor units 60b to 60d during operation as well as the indoor unit 60a. Then, the outdoor unit control means 21 controls the opening degree of the expansion valves 6a to 6d so that the temperature difference ΔTek of each temperature difference ΔTea to ΔTed does not exceed the dry allowable threshold value T1. For example, the outdoor unit control means 21 controls the opening degree of the expansion valves 6a to 6d so that there is no indoor unit in which each temperature difference ΔTek is 5 ° C. or higher.

In the indoor units 60a to 60c other than the specially controlled unit, the amount of refrigerant circulating decreases as the opening degree of the expansion valves 6a to 6c decreases. Therefore, the temperature difference ΔTea to ΔTec becomes large, and the load side heat exchangers 7a to 7c become dry. When the temperature difference ΔTea to ΔTec becomes too large, a low temperature region and a high temperature region are generated inside the load side heat exchangers 7a to 7c. In this case, if dew condensation occurs on the load side heat exchangers 7a to 7c, the dew condensation water adheres to the indoor fans 8a to 8c, and the risk of dew splashing increases. Therefore, the outdoor unit control means 21 corrects the opening degree of the expansion valves 6a to 6d so that the temperature difference ΔTea to ΔTek of the other indoor units 60a to 60c excluding the special control target unit does not exceed the dry allowable threshold value T1. As a result, dew flying can be avoided.

Next, an example of the operation procedure of step S6 shown in FIG. 4 will be described. FIG. 8 is a diagram showing an example of the operation procedure of step S6 shown in FIG. The outdoor unit control means 21 calculates the synthetic Cv value required for the refrigerating capacity of the air conditioner 100 from the relationship between the opening degree and the flow rate obtained from the flow rate characteristic data of the expansion valves 6a to 6d (step S61).

FIG. 9 is a diagram showing an example of the operation procedure of step S61 shown in FIG. The outdoor unit control means 21 calculates the Cv value of each expansion valve from the current opening degree of the expansion valves 6a to 6d corresponding to the operating indoor units 60a to 60d based on the flow rate characteristic data of each expansion valve. (Step S61-1). The current opening degrees of the expansion valves 6a to 6d are expressed as Pat to Pdt. Assuming that the special control target machine is the indoor unit 60d, the Cv value of the expansion valve 6d of the special control target machine is expressed as Cvd. The Cv values of the expansion valves 6a to 6c of the indoor units 60a to 60c other than the special control target machine are represented by Cva to Cvc.

The outdoor unit control means 21 calculates the combined Cv value by adding the Cv values of the expansion valves calculated in step S61-1 for the expansion valves corresponding to the indoor unit in operation (step S61-2). The outdoor unit control means 21 stores the calculated synthetic Cv value. When the combined Cv value of the expansion valve corresponding to the indoor unit being operated is expressed as Cvall, when the indoor units 60a to 60d are operating, Cvall is represented by Cvall = Cva + Cvb + Cvc + Cvd.

The outdoor unit control means 21 calculates the ratio of the Cv value of each expansion valve to the synthetic Cv value for the expansion valves 6a to 6c of the other indoor units 60a to 60c excluding the special control target unit (step S61-3). The Cv value ratio of the expansion valves 6a to 6c is expressed as Sa to Sc. The Cv value ratio Sa of the expansion valve 6a is calculated by Sa = Cva / (Cva + Cvb + Cvc). The Cv value ratio Sb of the expansion valve 6b is calculated by Sb = Cvb / (Cva + Cvb + Cvc). The Cv value ratio Sc of the expansion valve 6c is calculated by Sc = Cvc / (Cva + Cvb + Cvc). After that, the outdoor unit control means 21 shifts to step S62.

In step S62 shown in FIG. 8, the outdoor unit control means 21 corrects the opening degree of the expansion valve 6d of the special control target machine. FIG. 10 is a diagram showing an example of the operation procedure of step S62 shown in FIG. The current opening degree of the expansion valve 6d is represented by Pdt, and the corrected opening degree is represented by Pdt + 1. The corrected opening degree is expressed as a determined opening degree ΔP. The outdoor unit control means 21 corrects the opening Pdt of the expansion valve 6d of the special control target machine to the side that opens by the opening ΔP (step S62-1). The number of pulses of the opening degree ΔP is, for example, 20 pulses. The corrected opening Pdt + 1 is represented by Pdt + 1 = Pdt + ΔP.

The outdoor unit control means 21 corrects the opening degree of the expansion valve 6d in step S62-1, and then calculates the Cv value from the corrected opening degree Pdt + 1 of the expansion valve 6d based on the flow rate characteristic data of the expansion valve 6d. (Step S62-2). The Cv value of the expansion valve 6d after the opening degree is corrected is expressed as Cvd *. After that, the outdoor unit control means 21 shifts to step S63.

In step S63 shown in FIG. 8, the outdoor unit control means 21 calculates the correction amount of the opening degree of the expansion valves 6a to 6c of the other indoor units 60a to 60c. FIG. 11 is a diagram showing an example of the operation procedure of step S63 shown in FIG. The outdoor unit control means 21 subtracts the Cv value Cvd * of the expansion valve 6d calculated in step S62-2 from the synthetic Cv value Cvall calculated in step S61-2. The outdoor unit control means 21 stores the calculation result as the total Cv value Cvn (step S63-1). The total Cv value Cvn is represented by Cvn = Cvall-Cvd *.

The outdoor unit control means 21 multiplies the total Cv value Cvn calculated in step S63-1 by the Cv value ratio Sk of the other indoor unit 60k calculated in step S61-3, thereby multiplying the other indoor units 60a to 60c. The Cv values of the expansion valves 6a to 6c of the above are calculated (step S63-2). The Cv values of the expansion valves 6a to 6c are represented by Cva * to Cvc *. The Cv value Cva * of the expansion valve 6a is represented by Cva * = Cvn × Sa. The Cv value Cvb * of the expansion valve 6b is represented by Cvb * = Cvn × Sb. The Cv value Cvc * of the expansion valve 6c is represented by Cvc * = Cvn × Sc.

Further, the outdoor unit control means 21 sets the Cv values of the expansion valves 6a to 6c of the other indoor units 60a to 60c calculated in step S63-2 to the opening degree corresponding to the flow rate characteristic data of the expansion valve 6k. Convert. Then, the outdoor unit control means 21 stores the converted opening degree of each expansion valve of the expansion valves 6a to 6c (step S63-3). After that, the outdoor unit control means 21 shifts to step S64.

In step S64 shown in FIG. 8, the outdoor unit control means 21 corrects the opening degree of the expansion valves 6a to 6c of the other indoor units 60a to 60c excluding the special control target machine. FIG. 12 is a diagram showing an example of the operation procedure of step S64 shown in FIG. The outdoor unit control means 21 calculates and stores the opening degree difference ΔPkt between the opening degree Pkt of each expansion valve 6k recognized in step S61-1 and the converted opening degree Pkt * stored in step S63-3 ( Step S64-1). The difference between the current opening degree of each of the expansion valves 6a to 6c and the opening degree after conversion is expressed as ΔPat to ΔPat. The opening difference ΔPat is represented by ΔPat = Pat-Pat *. The opening difference ΔPbt is represented by ΔPbt = Pbt-Pbt *. The opening difference ΔPct is represented by ΔPct = Pct-Pct *. The outdoor unit control means 21 stores each opening degree difference ΔPkt.

Then, the outdoor unit control means 21 imparts the opening difference ΔPkt stored in step S64-1 to the opening Pkt of the expansion valves 6a to 6c of the other indoor units 60a to 60c as a correction value in the closing direction (step). S64-2). The corrected opening degree of the expansion valves 6a to 6c is expressed as Pat + 1 to Pct + 1. The corrected opening Pat + 1 is represented by Pat + 1 = Pat−ΔPat. The corrected opening Pbt + 1 is represented by Pbt + 1 = Pbt−ΔPbt. The corrected opening Pct + 1 is represented by Pct + 1 = Pct−ΔPct. After that, the outdoor unit control means 21 shifts to step S65.

In step S65 shown in FIG. 8, the outdoor unit control means 21 calculates the temperature difference between the refrigerant temperature and the refrigerant saturation temperature in the load side heat exchanger 7k for each of the operating indoor units 60k. FIG. 13 is a diagram showing an example of the operation of step S65 shown in FIG. The outdoor unit control means 21 calculates the temperature difference ΔTek between the refrigerant temperature T17k detected by the load-side temperature detecting means 17k and the refrigerant saturation temperature T16k detected by the load-side saturation temperature detecting means 16k for each operating indoor unit 60k. (Step S65-1).

In step S66 shown in FIG. 8, the outdoor unit control means 21 determines whether or not each temperature difference ΔTek calculated in step S65 is equal to or greater than the dry tolerance threshold T1. For example, when T17k = 14 ° C., T16k = 11 ° C., and T1 = 5 ° C., ΔTek = T17k-T16k is smaller than the dry tolerance threshold T1. In this case, the outdoor unit control means 21 returns to step S61. On the other hand, for example, when T17 = 17 ° C., T16 = 11 ° C. and T1 = 5 ° C., ΔTe = T17-T16 is larger than the dry tolerance threshold T1. In this case, the outdoor unit control means 21 shifts to step S67.

In step S67 shown in FIG. 8, the outdoor unit control means 21 makes a correction to increase the opening degree of the expansion valve of the indoor unit that meets the conditions of step S66. FIG. 14 is a diagram showing an example of the operation of step S67 shown in FIG. When the temperature difference ΔTej is equal to or greater than the dry tolerance threshold T1 in step S66, the outdoor unit control means 21 adds the correction value ΔPjt obtained in step S64-2 to the opening degree of the expansion valve 6j of the indoor unit 60j (step S67-). 1). Let j be an arbitrary identification code of a to d for distinguishing the indoor unit. The corrected opening degree is expressed as Pjt + 2. The corrected opening Pjt + 2 is represented by Pjt + 2 = Pjt + 1 + ΔPjt.

After that, in step S68 shown in FIG. 8, the outdoor unit control means 21 determines whether or not tp1 has elapsed for a certain period of time after receiving the capacity distribution correction signal in step S4 of FIG. If tp1 has not elapsed for a certain period of time, the outdoor unit control means 21 returns to step S65. The outdoor unit control means 21 rejects the reception of the capacity distribution correction signal from the other remote controllers 70a to 70c until tp1 elapses for a certain period of time after receiving the capacity distribution correction signal from the remote controller 70d. The outdoor unit control means 21 sets the special control target unit to one indoor unit and performs capacity distribution correction control, thereby suppressing the refrigeration cycle of the air conditioner 100 from becoming unstable. As a result of the determination in step S68, when tp1 has elapsed for a certain period of time, the outdoor unit control means 21 ends the capacity distribution correction control.

The outdoor unit control means 21 controls the indoor unit corresponding to the other indoor units 60a to 60c to the effect that the capacity distribution correction control is being performed from the time when the capacity distribution correction signal is received until tp1 elapses for a certain period of time. The means 20a to 20c may be notified. In this case, even if the indoor unit control means 20a to 20c receive the capacity distribution correction signal from the remote controllers 70a to 70c, the capacity distribution correction signal is not transferred to the outdoor unit control means 21. As a result, the load of communication processing between the outdoor unit control means 21 and the indoor unit control means 20a to 20c is reduced.

Further, when the outdoor unit control means 21 receives the capacity distribution correction signal from the remote controllers 70a to 70c before the elapse of tp1 for a certain period of time, the outdoor unit control means 21 receives the refusal information indicating that the reception of the capacity distribution correction signal is rejected. It may be output to other indoor units 60a to 60c. For example, the indoor units 60a to 60d may have a display unit not shown in the figure, and the outdoor unit control means 21 may display the refusal information on the display unit to the indoor unit control means 20a to 20c. Further, the display unit may be a light emitting unit. In this case, the outdoor unit control means 21 may cause the indoor unit control means 20a to 20c to emit light from the light emitting unit in order to notify the user of the refusal information.

Further, the means for outputting the veto information is not limited to the display means. The indoor units 60a to 60d may have a speaker (not shown in the figure), and the outdoor unit control means 21 may cause the indoor unit control means 20a to 20c to output an alarm sound for notifying the user of the refusal information to the speaker. .. Further, the remote controllers 70a to 70c may include one or both of the display unit and the speaker. The outdoor unit control means 21 may output the refusal information to one or both of the indoor unit 60i and the remote controller 70i other than the special control target unit. i is an arbitrary identification code of a to c for distinguishing the indoor unit. When the room temperature does not change even if the set temperature is lowered by operating the remote controller 70i, the capacity distribution correction control of another indoor unit is performed from the refusal information output by the remote controller 70i or the indoor unit 60i. You can know that.

As described with reference to FIGS. 8 to 14, the control device 30 controls to increase the opening degree of the expansion valve 6d and decrease the opening degree of the expansion valves 6a to 6c, and all the expansion valves 6a to 6a. The synthetic Cv value of 6d is kept unchanged. Therefore, when the plurality of indoor units 60a to 60d are operated in parallel, the capacity distribution to each indoor unit can be corrected, and the stability of the refrigeration cycle of the air conditioner 100 can be maintained.

Further, in the indoor units 60a to 60d in operation, the temperature difference ΔTek between the detection value of the load side temperature detecting means 17k and the detection value of the load side saturation temperature detecting means 16k is smaller than the dry allowable threshold value T1. The expansion valves 6a to 6d are controlled so as to be. Therefore, when the plurality of indoor units 60a to 60d are operated in parallel, the capacity distribution to each indoor unit can be corrected, and the condensation water can be prevented from adhering to the indoor fans 8a to 8d.

[Modification 1]
Another operation procedure of the air conditioner 100 of the first embodiment will be described. FIG. 15 is a flow chart showing an operation procedure of the first modification of the control method of the air conditioner shown in FIG. In the first modification, detailed description of the same processing as that described with reference to FIG. 4 will be omitted.

As shown in FIG. 15, after step S5, the outdoor unit control means 21 corrects the target evaporation temperature used for controlling the cooling operation for a certain period of time tp1 (step S10). FIG. 16 is a diagram showing an example of the operation of step S10 shown in FIG. The outdoor unit control means 21 changes the target evaporation temperature to a target evaporation temperature for capacity distribution correction control, which is a temperature lower than the current target evaporation temperature (step S10-1). For example, the outdoor unit control means 21 changes the target evaporation temperature from 11 ° C. to 7 ° C. After that, the outdoor unit control means 21 shifts to step S6.

However, in step S10, the outdoor unit control means 21 needs to be set so that the target evaporation temperature for capacity distribution correction control is equal to or higher than the lower limit threshold value Tthmin of the target evaporation temperature held by each of the indoor units 60a to 60d. There is. The lower limit threshold value Tthmin is, for example, the maximum value of the dew point in each air-conditioned space of the indoor units 60a to 60d. If the target evaporation temperature is lowered too much, dew condensation may occur on the load side heat exchangers 7a to 7c of the indoor units 60a to 60c whose refrigerating capacity is not insufficient, and dew condensation water may drip out of the indoor units 60a to 60c. Because there is. Further, also in the first modification, the outdoor unit control means 21 corrects the opening degree of the expansion valves 6a to 6d so as to satisfy the condition of avoiding dew splash.

In the first modification, by changing the target evaporation temperature for a certain period of time tp1, not only the indoor unit 60d having a insufficient refrigerating capacity but also the refrigerating capacity as a whole can be improved.

Although the air conditioner as shown in FIG. 1 has been described as an example of the air conditioner of the first embodiment, the number of indoor units connected is not limited to four. The air conditioner of the first embodiment includes a multi-type air conditioner in which a plurality of indoor units are connected to outdoor units.

When the control device 30 receives a capacity distribution correction signal indicating insufficient refrigerating capacity from one remote controller, the air conditioner 100 of the first embodiment is an indoor unit corresponding to the remote controller that is the source of the capacity distribution correction signal. Is recognized as a special control target machine. Then, the control device 30 increases the opening degree of the expansion valve of the special control target machine, and reduces the opening degree of the expansion valve of the other indoor units other than the special control target machine among the plurality of indoor units.

According to the first embodiment, when the outdoor unit control means 21 receives the capacity distribution correction signal from the remote controller, it freezes the load by adjusting the opening degree of each expansion valve 6a to 6d. Increase the amount of refrigerant circulating in the indoor unit that lacks capacity. Therefore, the refrigerating capacity of the plurality of indoor units 60a to 60d can be adjusted without the user operating the remote controller to equalize the refrigerating capacity. As a result, it is possible to improve the refrigerating capacity of the indoor units having insufficient refrigerating capacity while maintaining the stability of the operating state of the plurality of indoor units 60a to 60d.

In the first embodiment, in the case of cooling operation, the control device 30 controls the operating frequency of the compressor 1 so that the evaporation temperature of the load side heat exchanger of the indoor unit during operation matches the target evaporation temperature. Upon receiving the capacity distribution correction signal, the target evaporation temperature may be changed to a lower temperature. In this case, not only the indoor unit having insufficient refrigerating capacity but also the refrigerating capacity can be improved as a whole.

In the first embodiment, the control device 30 calculates the Cv value from the opening degree of each expansion valve, obtains the combined Cv value obtained by synthesizing the Cv value of each expansion valve, and the combined Cv value is a value required for the refrigerating capacity. The opening degree of each expansion valve may be corrected so as to maintain. By adjusting the opening degree of the expansion valve corresponding to the indoor unit in operation by the control device 30 so that the synthetic Cv value becomes constant, the specific indoor unit can be maintained while maintaining the stability of the refrigerating cycle of the air conditioner 100. The amount of refrigerant circulating to the air conditioner can be adjusted. In particular, the effect of correcting the refrigerating capacity distribution is improved during cooling operations with different air conditioning loads.

In the first embodiment, in the control device 30, the temperature difference between the refrigerant temperature detected by the load-side temperature detecting means provided in the indoor unit during operation and the refrigerant saturation temperature of the load-side heat exchanger is equal to or greater than the allowable dry threshold. The opening degree of the expansion valve corresponding to the indoor unit during operation is controlled so as not to become. Further, the control device 30 is operated so that the refrigerant temperature detected by the load-side temperature detecting means provided in the indoor unit during operation and the refrigerant saturation temperature of the load-side heat exchanger are higher than the determined lower limit threshold value. Controls the opening of the expansion valve corresponding to the indoor unit inside. In this case, the occurrence of dew condensation is suppressed in each load side heat exchanger during the cooling operation, and the risk of dew splashing from the indoor unit can be avoided.

In the first embodiment, the outdoor unit control means 21 informs the other indoor unit 60i that the capacity distribution correction control is being performed from the time when the capacity distribution correction signal is received until tp1 elapses for a certain period of time. The corresponding indoor unit control means 20i may be notified. In this case, unless the indoor unit control means 20i transfers the capacity distribution correction signal received from the remote controller 70i to the outdoor unit control means 21, the load of communication processing between the outdoor unit control means 21 and the indoor unit control means 20i is reduced. To do.

In the first embodiment, the control device 30 rejects the reception of the capacity distribution correction signal from the remote controller corresponding to the other indoor unit until a certain time elapses after receiving the capacity distribution correction signal. You may. When the control device 30 sets the special control target unit to one indoor unit and performs capacity distribution correction control, it is possible to prevent the refrigeration cycle of the air conditioner 100 from becoming unstable.

In the first embodiment, when the control device 30 receives the capacity distribution correction signal from the other remote controller, the control device 30 notifies the other indoor unit and the other remote controller that the reception of the capacity distribution correction signal is rejected. It may be output to one or both. In this case, the user can know from the refusal information output by the remote controller or the indoor unit that the capacity distribution correction control of the other indoor unit is being performed.

1 Compressor, 2 Four-way valve, 3 Heat source side heat exchanger, 4 Outdoor fan, 5 Outdoor fan motor, 6a to 6d expansion valve, 7a to 7d Load side heat exchanger, 8a to 8d Indoor fan, 9a to 9d Indoor fan Motor, 10 liquid side valve, 11 gas side valve, 12 discharge temperature detecting means, 13 heat source side saturation temperature detecting means, 14 outside air temperature detecting means, 15 heat source side temperature detecting means, 16a to 16d load side saturation temperature detecting means, 17a ~ 17d Load side temperature detecting means, 18a ~ 18d Room temperature detecting means, 19 Liquid reservoir, 20a ~ 20d Indoor unit control means, 21 Outdoor unit control means, 30 Control device, 31 Memory, 32 CPU, 40 Refrigerant circuit, 50 Outdoor unit , 60a-60d indoor unit, 70a-70d remote controller, 80a-80d extension pipe, 100 air exchanger.

The present invention relates to an air conditioner having a plurality of indoor units.

The present invention has been made to solve the above problems, and the refrigerating capacity is insufficient even if the user does not perform an operation to equalize the refrigerating capacity of a plurality of indoor units operating in parallel. It provides an air conditioner that automatically improves the refrigerating capacity of the machine.

The air conditioner according to the present invention corresponds to a plurality of indoor units each provided with a load side heat exchanger, a plurality of remote controllers corresponding to the plurality of indoor units, and a plurality of the load side heat exchangers. It has a plurality of expansion valves and a control device for controlling the operation of the plurality of indoor units, and the control device has an ability to indicate insufficient refrigerating capacity from one of the plurality of remote controllers. When the distribution correction signal is received, the indoor unit corresponding to the remote controller that is the source of the capacity distribution correction signal is recognized as the special control target unit, and the opening degree of the expansion valve corresponding to the special control target unit is increased. Among the plurality of indoor units, the opening degree of the expansion valve corresponding to the other indoor unit excluding the special control target machine is reduced , the Cv value is calculated from the opening degree of each expansion valve, and the Cv of each expansion valve is calculated. The combined Cv value is obtained by combining the values, and the opening degree of each expansion valve is corrected so that the combined Cv value maintains the value required for the refrigerating capacity of the air conditioner.

Claims (9)

Multiple indoor units each equipped with a load side heat exchanger,
A plurality of remote controllers corresponding to the plurality of indoor units and
A plurality of expansion valves corresponding to the plurality of load side heat exchangers,
It has a control device for controlling the operation of the plurality of indoor units, and has
The control device is
When a capacity distribution correction signal indicating insufficient refrigerating capacity is received from one of the plurality of remote controllers, the indoor unit corresponding to the remote controller from which the capacity distribution correction signal is transmitted is recognized as a special control target unit. Then, the opening degree of the expansion valve corresponding to the special control target machine is increased, and the opening degree of the expansion valve corresponding to the other indoor units other than the special control target machine among the plurality of indoor units is reduced.
Air conditioner. It has an outdoor unit including a compressor that compresses and discharges the refrigerant into a refrigerant circuit in which the plurality of load-side heat exchangers and the plurality of expansion valves are connected by a refrigerant pipe.
In the case of cooling operation, the control device controls the operating frequency of the compressor so that the evaporation temperature of the load side heat exchanger of the indoor unit during operation matches the target evaporation temperature, and outputs the capacity distribution correction signal. The air conditioner according to claim 1, wherein when received, the target evaporation temperature is changed to a lower temperature. The control device is
The Cv value is calculated from the opening degree of each expansion valve, the synthetic Cv value obtained by synthesizing the Cv value of each expansion valve is obtained, and the combined Cv value maintains the value required for the refrigerating capacity of the air conditioner. The air conditioner according to claim 1 or 2, wherein the opening degree of each expansion valve is corrected. It has a plurality of load-side temperature detecting means for detecting the refrigerant temperature of the plurality of load-side heat exchangers.
The control device is
During operation, the temperature difference between the refrigerant temperature detected by the load-side temperature detecting means provided in the indoor unit during operation and the refrigerant saturation temperature of the load-side heat exchanger does not exceed a predetermined dry tolerance threshold. The air conditioner according to any one of claims 1 to 3, which controls the opening degree of the expansion valve corresponding to the indoor unit. The control device is
In the indoor unit during operation, the refrigerant temperature detected by the load-side temperature detecting means provided in the indoor unit during operation and the refrigerant saturation temperature of the load-side heat exchanger are higher than a predetermined lower limit threshold value. The air conditioner according to claim 4, which controls the opening degree of the corresponding expansion valve. The control device is
A plurality of indoor unit control means corresponding to the plurality of indoor units, and
It has an outdoor unit control means that is connected to the plurality of indoor unit control means and controls the plurality of expansion valves.
The outdoor unit control means sends information to the effect that the capacity distribution correction control is being performed to the indoor unit control means corresponding to the other indoor unit until a certain time elapses after receiving the capacity distribution correction signal. The air conditioner according to any one of claims 1 to 5, which is notified. The control device is
Any of claims 1 to 6, which refuses to receive the capacity distribution correction signal from the remote controller corresponding to the other indoor unit until a certain time elapses after receiving the capacity distribution correction signal. Or the air conditioner according to item 1. The control device is
If the capacity distribution correction signal is received from the remote controller corresponding to the other indoor unit before the lapse of a certain period of time, the information indicating that the reception of the capacity distribution correction signal is rejected is provided. The air conditioner according to claim 7, wherein one or both of the other indoor unit and the remote controller corresponding to the other indoor unit output the output. A control method for an air conditioner having a plurality of indoor units each provided with a load-side heat exchanger and a plurality of expansion valves corresponding to the plurality of load-side heat exchangers.
When a capacity distribution correction signal indicating insufficient refrigerating capacity is received from one of the plurality of remote controllers corresponding to the plurality of indoor units, the indoor unit corresponding to the remote controller from which the capacity distribution correction signal is transmitted is received. And the step of recognizing as a special control target machine
A step of increasing the opening degree of the expansion valve of the special control target machine and reducing the opening degree of the expansion valve of the other indoor unit other than the special control target machine among the plurality of indoor units.
A method of controlling an air conditioner.

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