Device for controlling refrigeration cycle device, and refrigeration cycle device

Abstract

This device for controlling a refrigeration cycle device comprises a control processing device that controls the opening degrees of at least one indoor-side expansion valve and a bypass expansion valve. The control processing device: sets a total opening degree, which is an expansion valve opening degree related to the refrigerant flow rate of a refrigerant circuit; and performs expansion valve control by distributing the total opening degree to an indoor-side total opening degree, which is the total of the opening degrees of the at least one indoor-side expansion valve, and a bypass expansion valve opening degree, which is the opening degree of the bypass expansion valve, on the basis of a first distribution ratio that is set so as to maintain a relative magnitude relationship between a total cooling capacity, which is the total cooling capacity of the at least one indoor-side heat exchanger, and an internal heat exchange capacity, which is the heat exchange capacity of an internal heat exchanger.

Description

Control device and refrigeration cycle device

[0001] This disclosure relates to a control device for a refrigeration cycle system having a bypass circuit and to a refrigeration cycle system.

[0002] Conventionally, there is a refrigeration cycle device that comprises an outdoor unit and multiple indoor units, where the outdoor unit has a compressor, an outdoor heat exchanger, and an internal heat exchanger, and each indoor unit has an indoor expansion valve and an indoor heat exchanger (see, for example, Patent Document 1). The refrigeration cycle device of Patent Document 1 has a main circuit that connects the compressor, the outdoor heat exchanger, the high-pressure side flow path of the internal heat exchanger, each indoor expansion valve, and each indoor heat exchanger with refrigerant piping. The refrigeration cycle device of Patent Document 1 further has a bypass circuit that branches off from the main circuit and is connected to the suction side of the compressor via the low-pressure side flow path of the internal heat exchanger, and a bypass expansion valve that adjusts the flow rate of refrigerant passing through the low-pressure side flow path of the internal heat exchanger. The refrigeration cycle device of Patent Document 1 suppresses a decrease in cooling capacity by supercooling the refrigerant that has flowed out of the internal heat exchanger in the main circuit through heat exchange with the refrigerant passing through the internal heat exchanger in the bypass circuit.

[0003] Japanese Patent Application Publication No. 5-10618

[0004] Patent Document 1 describes controlling the bypass expansion valve based on the degree of superheating of the refrigerant drawn into the compressor, but it does not describe the control of each indoor expansion valve. In the refrigeration cycle system of Patent Document 1, if the bypass expansion valve and each indoor expansion valve are controlled independently of each other, the operation of each expansion valve will interfere with each other, potentially reducing control performance and preventing efficient operation. This problem occurs not only when there are multiple indoor units, but also when there is only one indoor unit, because the operation of the bypass expansion valve and the indoor expansion valve are independent of each other.

[0005] This disclosure has been made in consideration of these points, and aims to provide a control device and a refrigeration cycle device that can suppress the deterioration of control performance and realize efficient operation.

[0006] The control device for a refrigeration cycle system according to this disclosure comprises a refrigerant circuit having a main circuit connecting a compressor, an outdoor heat exchanger, a high-pressure side passage of an internal heat exchanger, at least one indoor expansion valve, and at least one indoor heat exchanger with refrigerant piping; a bypass piping branching from between the internal heat exchanger and at least one indoor expansion valve of the main circuit and connected to the suction side of the compressor via the low-pressure side passage of the internal heat exchanger; and a bypass circuit provided in the bypass piping and equipped with a bypass expansion valve that adjusts the flow rate of refrigerant passing through the low-pressure side passage of the internal heat exchanger, The system includes a control device that controls the opening degree of at least one indoor expansion valve and a bypass expansion valve. The control device sets the total opening degree, which is the expansion valve opening degree related to the refrigerant flow rate of the refrigerant circuit, and controls the expansion valves by distributing the total opening degree to the total indoor opening degree, which is the sum of the opening degrees of at least one indoor expansion valve, and the bypass expansion valve opening degree, which is the opening degree of the bypass expansion valve, based on a first distribution ratio set to maintain the relative magnitude relationship between the total cooling capacity, which is the sum of the cooling capacities of at least one indoor heat exchanger, and the internal heat exchange capacity, which is the heat exchange capacity of the internal heat exchanger.

[0007] The refrigeration cycle device according to this disclosure comprises a control device for the refrigeration cycle device described above, and a refrigerant circuit.

[0008] According to this disclosure, the degradation of control performance can be suppressed, enabling efficient operation.

[0009] This is a schematic diagram showing an example of the refrigerant circuit of a refrigeration cycle device according to Embodiment 1. This is a functional block diagram showing the functions of the control device in Figure 1. This is a p-h diagram showing the refrigerant state of the refrigerant circuit of a refrigeration cycle device according to Embodiment 1. This is a p-h diagram showing the refrigerant state of the refrigerant circuit of a refrigeration cycle device according to a comparative example. This is a block diagram showing an example of the configuration of the part that controls the indoor expansion valve and bypass expansion valve in the control processing device of a refrigeration cycle device according to Embodiment 1. This is a flowchart showing the expansion valve control in the control processing device of a refrigeration cycle device according to Embodiment 1. This is a schematic diagram showing an example of the refrigerant circuit of a refrigeration cycle device according to Embodiment 2. This is a block diagram showing an example of the configuration of the part that controls the indoor expansion valve and bypass expansion valve in the control processing device3.

[0010] The following description of the refrigeration cycle apparatus according to the embodiments of this disclosure will be made with reference to the drawings. In the following drawings, components with the same reference numerals are the same or equivalent components, and this is consistent throughout the entire specification. Furthermore, the forms of the components shown throughout the specification are merely examples and are not limited to these descriptions. In addition, the high and low temperatures and pressures are not determined in relation to absolute values, but rather are determined relatively in relation to the state and operation of the system and apparatus, etc.

[0011] [Embodiment 1] Figure 1 is a schematic diagram showing an example of a refrigerant circuit 10a of a refrigeration cycle device 1 according to Embodiment 1. In Embodiment 1, a refrigeration cycle device 1 that performs indoor cooling will be described as an example of a refrigeration cycle device 1. The refrigeration cycle device 1 of Embodiment 1 will be described in terms of operation aimed at reducing power consumption during cooling, so its operation will be limited to cooling.

[0012] As shown in Figure 1, the refrigeration cycle system 1 comprises an outdoor unit 10 and indoor units 20a, 20b, 20c, and 20d. The outdoor unit 10 comprises a compressor 11, an outdoor heat exchanger 12, an internal heat exchanger (HIC) 13, and a bypass expansion valve 15b. The indoor units 20a, 20b, 20c, and 20d comprise indoor expansion valves 21a, 21b, 21c, and 21d, indoor heat exchangers 22a, 22b, 22c, and 22d, and indoor fans 23a, 23b, 23c, and 23d. The indoor units 20a, 20b, 20c, and 20d are connected in parallel to each other.

[0013] Hereafter, if indoor units 20a, 20b, 20c, and 20d are not distinguished, they will be collectively referred to as indoor unit 20. Similarly, if indoor expansion valves 21a, 21b, 21c, and 21d are not distinguished, they will be collectively referred to as indoor expansion valve 21. If indoor heat exchangers 22a, 22b, 22c, and 22d are not distinguished, they will be collectively referred to as indoor heat exchanger 22. If indoor fans 23a, 23b, 23c, and 23d are not distinguished, they will be collectively referred to as indoor fan 23. Note that in Figure 1, the refrigeration cycle device 1 has four indoor units 20, but it is sufficient to have one or more.

[0014] The refrigeration cycle device 1 includes a compressor 11, an outdoor heat exchanger 12, a high-pressure side flow path 13a of an indoor heat exchanger 13, an indoor expansion valve 21, and an indoor heat exchanger 22, all of which are sequentially connected by refrigerant piping 1a to form a main circuit 14 through which the refrigerant circulates. The main circuit 14 is part of the refrigerant circuit 10a.

[0015] The compressor 11 compresses the inhaled refrigerant and discharges it. The compressor 11 may also have a capacity (amount of refrigerant discharged per unit time) that can be changed by arbitrarily changing the drive frequency using, for example, an inverter circuit (not shown).

[0016] The outdoor heat exchanger 12 performs heat exchange between the refrigerant and air, condensing the refrigerant into a liquid state and heating the air. The outdoor heat exchanger 12 is a heat exchanger that functions as a condenser. The outdoor heat exchanger 12 is composed of, for example, a plate fin tube type heat exchanger. The outdoor heat exchanger 12 is not limited to a plate fin tube type heat exchanger, and may also be a plate type heat exchanger. In a plate type heat exchanger, the spaces between multiple thin plates arranged at intervals alternately serve as refrigerant flow paths and heat transfer fluid flow paths, and heat exchange between the refrigerant and a heat transfer fluid such as water or brine. In other words, the heat transfer fluid that exchanges heat with the refrigerant in the outdoor heat exchanger 12 does not necessarily have to be air; it may also be water or brine, etc.

[0017] The internal heat exchanger 13 has a high-pressure side flow path 13a and a low-pressure side flow path 13b, and performs heat exchange between the main refrigerant of the main circuit 14 flowing through the high-pressure side flow path 13a and the bypass refrigerant of the bypass circuit 15 (described later) flowing through the low-pressure side flow path 13b. The internal heat exchanger 13 aims to improve refrigeration efficiency by lowering the enthalpy of the main refrigerant and performing supercooling by exchanging heat between the main refrigerant and the bypass refrigerant. The internal heat exchanger 13 is composed of, for example, a double-tube heat exchanger in which heat exchange takes place inside and outside of double-walled tubes.

[0018] The indoor expansion valve 21 is composed of a variable-opening expansion valve, such as an electronic expansion valve, and adjusts the pressure and flow rate of the refrigerant. The opening of the indoor expansion valve 21 is controlled by the control device 30, which will be described later.

[0019] The indoor heat exchanger 22 performs heat exchange between the refrigerant and the air, evaporating and vaporizing the refrigerant while cooling the air. The indoor heat exchanger 22 is a heat exchanger that functions as an evaporator. The indoor heat exchanger 22 is composed of, for example, a plate fin tube type heat exchanger. The indoor heat exchanger 22 is not limited to a plate fin tube type heat exchanger, and may also be a plate type heat exchanger. In a plate type heat exchanger, the spaces between multiple thin plates arranged at intervals alternately serve as refrigerant flow paths and heat transfer fluid flow paths, and heat exchange between the refrigerant and a heat transfer fluid such as water or brine. In other words, the heat transfer fluid that exchanges heat with the refrigerant in the indoor heat exchanger 22 does not necessarily have to be air; it may also be water or brine, etc.

[0020] The indoor fan 23 blows air to the indoor heat exchanger 22. The indoor fan 23 is composed of a centrifugal fan or a multi-blade fan, etc. The indoor fan 23 may also have a variable airflow, where the drive speed can be arbitrarily changed by an inverter circuit (not shown), for example.

[0021] Each indoor heat exchanger 22 of each indoor unit 20 may be of the same type, or they may be of different types. Furthermore, each indoor heat exchanger 22 of each indoor unit 20 may have the same capacity, or they may have different capacities.

[0022] The refrigeration cycle device 1 further includes a bypass circuit 15. The bypass circuit 15 is part of the refrigerant circuit 10a. The refrigeration cycle device 1 has a main circuit 14 and a bypass circuit 15, which together constitute the refrigerant circuit 10a. A, B, and C in Figure 1 indicate specific locations in the refrigerant circuit 10a, and these locations will be explained in more detail later.

[0023] The bypass circuit 15 includes a bypass pipe 15a and a bypass expansion valve 15b. The bypass pipe 15a is a pipe that branches off from between the internal heat exchanger 13 and the indoor-side expansion valve 21 of the main circuit 14 and is connected to the suction side of the compressor 11 via the low-pressure side passage 13b of the internal heat exchanger 13. The bypass expansion valve 15b is used to depressurize and expand the refrigerant and is provided in the bypass pipe 15a. The bypass expansion valve 15b adjusts the flow rate of the refrigerant passing through the low-pressure side passage 13b of the internal heat exchanger 13. The bypass expansion valve 15b is an electronic expansion valve whose opening degree can be adjusted. The opening degree of the bypass expansion valve 15b is controlled by the control device 30.

[0024] The bypass circuit 15 is an injection circuit for injecting refrigerant branched off from the main circuit 14 between the internal heat exchanger 13 and the indoor expansion valve 21 into the compressor 11. The bypass circuit 15 contributes to improving heat exchange efficiency and reducing pressure loss by adjusting the excess refrigerant in the entire refrigerant circuit 10a and adjusting the dryness of the refrigerant drawn into the compressor 11, thereby improving operating efficiency.

[0025] Furthermore, the refrigeration cycle device 1 is equipped with, for example, a discharge temperature sensor 51. The discharge temperature sensor 51 is located in the piping on the discharge side of the compressor 11 and measures the temperature of the refrigerant discharged from the compressor 11. The discharge temperature sensor 51 is one of the state measuring sensors that measure the operating state quantity in the refrigerant circuit 10a. In addition to the discharge temperature sensor 51, the refrigeration cycle device 1 may also be equipped with temperature sensors and pressure sensors at various locations as state measuring sensors.

[0026] The refrigeration cycle device 1 is further equipped with a control device 30 that controls the entire refrigeration cycle device 1.

[0027] Figure 2 is a functional block diagram showing the functions of the control device 30 in Figure 1. As shown in Figure 2, the discharge temperature sensor 51 is connected to the control device 30, and sensor information from the discharge temperature sensor 51 is input to it. If the refrigeration cycle device 1 is equipped with other state measurement sensors, sensor information from those other state measurement sensors is also input to the control device 30. In addition, user commands and other information are input to the control device 30 via an operation unit (not shown).

[0028] As shown in Figure 2, the control device 30 includes a control processing unit 31, a timing device 32, and a storage device 33. The control processing unit 31 performs calculations and decisions based on data such as temperature input from the discharge temperature sensor 51, and controls the equipment of the refrigeration cycle device 1, such as the indoor expansion valve 21 and the bypass expansion valve 15b. The control processing unit 31 can be configured, for example, as a microcomputer having a control calculation processing unit such as a CPU (Central Processing Unit). The control processing unit 31 executes processing based on the program data stored in the storage device 33 to achieve control.

[0029] The timing device 32 is composed of, for example, a timer and performs timing. The timing device 32 is used for the control processing device 31's decision-making, etc. The storage device 33 is a device that stores data necessary for the control processing device 31 to perform processing. The storage device 33 has data that is a program of the processing procedure to be performed by the control processing device 31. The storage device 33 has a volatile storage device (not shown) such as a random access memory (RAM) that can temporarily store data, a hard disk, and a non-volatile auxiliary storage device (not shown) such as a flash memory that can store data long term. Each of the devices, the control processing device 31, the timing device 32, and the storage device 33, can be composed of dedicated hardware.

[0030] Next, the operation of the refrigeration cycle device 1 with the above configuration will be explained based on Figures 1 and 3.

[0031] Figure 3 is a p-h diagram showing the refrigerant state of the refrigerant circuit 10a of the refrigeration cycle device 1 according to Embodiment 1. The horizontal axis represents specific enthalpy [kJ / kg], and the vertical axis represents pressure [MPaA]. Curves SC represent the saturated liquid line and the saturated vapor line. The positions A, B, and C in Figure 3 correspond to the positions A, B, and C in Figure 1.

[0032] The gaseous refrigerant (1-1), compressed to high temperature and pressure by the compressor 11, is discharged from the outlet of the compressor 11 and flows into the outdoor heat exchanger 12. The gaseous refrigerant that flows into the outdoor heat exchanger 12 dissipates heat in the outdoor heat exchanger 12, liquefies under high pressure, and flows out from the outdoor heat exchanger 12 (1-2). The refrigerant that flows out from the outdoor heat exchanger 12 flows into the high-pressure side flow path 13a of the internal heat exchanger 13. The main refrigerant that flows into the high-pressure side flow path 13a of the internal heat exchanger 13 is supercooled by heat exchange with the bypass refrigerant after passing through the bypass expansion valve 15b of the bypass circuit 15 (1-3).

[0033] The refrigerant that has been supercooled in the internal heat exchanger 13 is partially bypassed from the main circuit 14 to the bypass circuit 15. The remaining refrigerant flows into the indoor unit 20. The refrigerant that has flowed into the indoor unit 20 is depressurized in the indoor expansion valve 21 and becomes a low-temperature two-phase state (1-4), and flows into the indoor heat exchanger 22. The low-temperature two-phase refrigerant that has flowed into the indoor heat exchanger 22 absorbs heat in the indoor heat exchanger 22, vaporizes under low pressure, and flows out from the indoor heat exchanger 22 ((1-5), point B). Here, the refrigerant state in (1-5) indicates the refrigerant state after the convergence of the outlets of each indoor heat exchanger 22.

[0034] Meanwhile, the refrigerant flowing into the bypass circuit 15 is depressurized by the bypass expansion valve 15b and becomes a low-temperature two-phase state (1-6). The low-temperature two-phase bypass refrigerant flows into the low-pressure side flow path 13b of the internal heat exchanger 13, exchanges heat with the main refrigerant in the main circuit 14, absorbs heat, and becomes a high-temperature gaseous refrigerant ((1-7), point A). The high-temperature gaseous refrigerant is injected from the bypass circuit 15 into the main circuit 14. That is, the high-temperature gaseous refrigerant in the bypass circuit 15 ((1-7), point A) merges with the refrigerant after it has merged at the outlets of each indoor heat exchanger 22 ((1-5), point B). The merged refrigerant ((1-8), point C) is drawn into the compressor 11 and compressed again. By repeating this operation, the refrigeration cycle of the refrigeration cycle device 1 is realized.

[0035] Next, the effectiveness of refrigerant injection in the refrigeration cycle device 1 will be explained in comparison with the comparative example.

[0036] Figure 4 is a p-h diagram showing the refrigerant state of the refrigerant circuit in the comparative example refrigeration cycle device. The horizontal axis is specific enthalpy [kJ / kg], and the vertical axis is pressure [MPaA]. Curves SC are the saturated liquid line and saturated vapor line. The comparative example refrigeration cycle device has the same configuration as the refrigeration cycle device 1 in Figure 1, but with the bypass circuit 15 removed. In the comparative example refrigeration cycle device, when there is an excessive inflow of refrigerant into the indoor unit, the pressure loss in the piping connected to the outlet of the indoor unit is large, causing a decrease in the refrigerant pressure on the suction side of the compressor. This pressure drop is represented by the change from point D to point E in Figure 4. In the comparative example refrigeration cycle device, the compression ratio increases due to the decrease in pressure on the suction side of the compressor, making it difficult to reduce power consumption.

[0037] On the other hand, the refrigeration cycle device 1 has a bypass circuit 15, and by diverting a portion of the refrigerant flowing through the main circuit 14 to the bypass circuit 15, the flow rate of refrigerant flowing into the indoor unit 20 can be optimized, thereby reducing pressure loss.

[0038] Furthermore, as shown in Figure 4, the refrigerant state at the outlet of the outdoor heat exchanger in the comparative example (1-3a) is closer to the saturated liquid line SC than the refrigerant state (1-3) of the refrigeration cycle device 1 shown in Figure 3. Therefore, in the comparative example, if there is a large pressure loss in the piping connecting the outdoor unit and the indoor unit, the refrigerant flowing out of the outdoor heat exchanger will be depressurized before it flows into the indoor expansion valve. In this case, the refrigerant flowing into the indoor expansion valve in the comparative example will be in a two-phase state, which may generate noise.

[0039] On the other hand, the refrigeration cycle device 1 shown in Figure 3 has a bypass circuit 15, which allows the degree of subcooling of the refrigerant before it flows into the indoor expansion valve 21 to be increased by the internal heat exchanger 13. Therefore, even if there is a large pressure loss in the piping connecting the outdoor unit 10 and the indoor unit 20, the refrigeration cycle device 1 can reliably bring the refrigerant flowing into the indoor expansion valve 21 into a liquid state, compared to the comparative example, and thus suppress the generation of noise.

[0040] Figure 5 is a block diagram showing an example of the configuration of the control processing unit 31 of the refrigeration cycle device 1 according to Embodiment 1, specifically the part that controls the indoor expansion valve 21 and the bypass expansion valve 15b. The control processing unit 31 comprises a refrigerant flow control unit 101, a first distributor 102, and a second distributor 103.

[0041] (Refrigerant flow control unit 101) The refrigerant flow control unit 101 controls the total value of the openings of all expansion valves (hereinafter referred to as the total opening S) for controlling the refrigerant flow rate of the refrigerant circuit 10a. ｔｏｔａｌ Set and output the following: Total opening degree S ｔｏｔａｌ This is the sum of the opening degrees of the indoor expansion valves 21a, 21b, 21c, and 21d, and the opening degree of the bypass expansion valve 15b. In other words, the refrigerant flow control unit 101 controls the total opening degree S of the expansion valves related to the refrigerant flow rate of the refrigerant circuit 10a. ｔｏｔａｌ Set and output.

[0042] The refrigerant flow control unit 101 controls the total opening degree S necessary to make the control index related to the operating state of the refrigerant circuit 10a follow the control index target value. ｔｏｔａｌSet and output it. When the refrigerant flow control unit 101 uses, for example, the discharge temperature as a control index, the total opening degree S is based on the discharge temperature deviation between the discharge temperature and the target discharge temperature. ｔｏｔａｌ Set and output it. The discharge temperature target value is set so that the suction superheat degree of the compressor 11 is relatively small. That is, the refrigerant flow control unit 101 sets and outputs the total opening degree S required to make the discharge temperature follow the target discharge temperature. ｔｏｔａｌ The discharge temperature is the temperature measured by the discharge temperature sensor 51. The control index is not limited to the discharge temperature, and may also be the degree of subcooling at the outlet of the outdoor heat exchanger 12, the degree of subcooling at the outlet of the internal heat exchanger 13, the suction superheat degree of the compressor 11, or the degree of superheat after the confluence at the outlet of the indoor heat exchanger 22. Further, the control index may be a combination thereof.

[0043] The refrigerant flow control unit 101 is, for example, composed of a PI controller. The refrigerant flow control unit 101 does not have to be a feedback controller such as a PI controller, and may output the total value of the expansion valve opening degrees by a function or a table based on the required capacity or the compressor rotation speed, the indoor and outdoor temperatures, etc. [[ID=D8]]

[0044] (First distributor 102) The first distributor 102 divides the total opening degree S output from the refrigerant flow control unit 101 into the total opening degree of each indoor expansion valve 21 (hereinafter referred to as the indoor total opening degree S ｔｏｔａｌ ), and the opening degree of the bypass expansion valve 15b (hereinafter referred to as the bypass expansion valve opening degree S ＩＤＵｓ ). The first distributor 102 is based on the first distribution ratio set so that the relative magnitude relationship between the total cooling capacity Q ＨＩＣ of each indoor heat exchanger 22 (hereinafter referred to as the total cooling capacity Q ＩＤＵ ), and the capacity of the internal heat exchanger 13 (hereinafter referred to as the internal heat exchange capacity Q ＩＤＵｓ ), divides the total opening degree S ＨＩＣ into the indoor total opening degree S ｔｏｔａｌ and the bypass expansion valve opening degree S ＩＤＵｓ and the bypass expansion valve opening degree S ＨＩＣThe first distribution ratio may be a preset fixed value or a variable value that changes according to the operating conditions. The following describes the case where the first distribution ratio is a fixed value. Details of the case where the first distribution ratio is a variable value will be described in Embodiment 2.

[0045] Specifically, the first distributor 102 has a total indoor opening degree S ＩＤＵｓ The bypass expansion valve opening S is calculated using the following equation (1). ＨＩＣ This is calculated using the following equation (2).

[0046]

[0047]

[0048] Total cooling capacity Q ＩＤＵｓ The value of Q may be a fixed value based on structural information relating to the structure of the indoor heat exchanger 22, or a variable value based on state information that changes during operation. Structural information refers to structural information such as hardware rated specifications, equipment specifications, design specifications, or equipment performance. Total cooling capacity Q ＩＤＵｓ If the value of is fixed, the total cooling capacity Q ＩＤＵｓ Q is, for example, the sum of the rated capacities of each indoor heat exchanger 22. Total cooling capacity Q ＩＤＵｓ Details regarding the case where the value is a variable value based on the operating state information will be explained in Embodiment 2.

[0049] Internal heat exchange capacity Q ＨＩＣ Similarly, the value of Q may be a fixed value based on structural information relating to the structure of the internal heat exchanger 13, or a variable value based on state information that changes during operation. Structural information refers to structural information such as hardware rated specifications, equipment specifications, design specifications, or equipment performance. Internal heat exchange capacity Q ＨＩＣ If the value of is fixed, then the internal heat exchange capacity Q ＨＩＣ Q is, for example, the rated capacity of the internal heat exchanger. ＨＩＣ This may be set based on the design specifications, such as the heat exchange rate of the internal heat exchanger 13, or it may be determined from test results under representative conditions. Internal heat exchange capacity Q ＨＩＣDetails regarding the case where the value is a variable value based on the operating state information will be explained in Embodiment 2.

[0050] (1) On the right side of equation S ｔｏｔａｌ The value multiplied by this is the total indoor opening S in the first distribution ratio. ＩＤＵｓ This is the ratio distributed to S on the right side of equation (2). ｔｏｔａｌ The value multiplied by is the bypass expansion valve opening S in the first distribution ratio. ＨＩＣ This is the ratio to which it is distributed. And, as is clear from equations (1) and (2) above, the first distributor 102 has a total indoor opening degree S ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ The ratio to Q ＩＤＵｓ and Q ＨＩＣ Using the proportional relationship that it is equal to the ratio of, the total opening degree S ｔｏｔａｌ Total opening angle S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ It is distributed to [the parties involved].

[0051] The first distributor 102 has a total opening degree S ｔｏｔａｌ When distributing the heat, it is not necessary to strictly maintain the above proportional relationship. In other words, for example, internal heat exchange capacity Q ＨＩＣ Total cooling capacity Q ＩＤＵｓ When it is twice as much, the bypass expansion valve opening S is maintained while strictly maintaining that proportional relationship. ＨＩＣ This does not necessarily mean the total opening angle S on the indoor side. ＩＤＵｓ It does not have to be twice the original value; for example, it could be 2.5 times, for instance.

[0052] Thus, the total opening angle S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ Q is the total cooling capacity. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ Not limited to strictly maintaining the proportional relationship, Q ＩＤＵｓ and Q ＨＩＣ It is sufficient that the relative magnitude relationship with Q is maintained. Therefore, for example, Q ＩＤＵｓ and Q ＨＩＣ Q ＩＤＵｓ <Q ＨＩＣ If the relationship is such that S ＩＤＵｓ <S ＨＩＣ It should be set to that. Also, Q ＩＤＵｓ and QＨＩＣ Q ＩＤＵｓ > Q ＨＩＣ If the relationship is such that S ＩＤＵｓ > S ＨＩＣ It should be set to that. Also, Q ＩＤＵｓ <Q ＨＩＣ It has a relationship with Q ＩＤＵｓ and Q ＨＩＣ As the difference with increases, S ＩＤＵｓ <S ＨＩＣ It has a relationship with S ＩＤＵｓ and S ＨＩＣ The difference between these two values ​​may also be set to be large.

[0053] As described above, the first distributor 102 has a total opening degree S ｔｏｔａｌ Based on the first distribution ratio, the total opening degree S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ Distribute it to them.

[0054] (Second distributor 103) The second distributor 103 receives the total indoor opening S output from the first distributor 102. ＩＤＵｓ Based on the second distribution ratio, the opening degree of each indoor expansion valve 21 is the indoor expansion valve opening degree S. ＩＤＵ It is distributed to the following. In the example in Figure 5, the second distributor 103 has a total indoor opening S. ＩＤＵｓ The indoor expansion valve opening degree S ＩＤＵａ S ＩＤＵｂ S ＩＤＵｃ and S ＩＤＵｄ Distribute to: Indoor expansion valve opening S ＩＤＵ This is the opening degree S of the indoor expansion valve. ＩＤＵａ S ＩＤＵｂ S ＩＤＵｃ and S ＩＤＵｄ It is a general term for [something].

[0055] The second distribution ratio may be a fixed value based on structural information, or a variable value that changes according to the operating conditions. Structural information refers to structural information such as the rated specifications, equipment specifications, or design specifications of the hardware. When the second distribution ratio is a fixed value based on structural information, it is set to have a positive correlation with the structural information of each indoor unit 20, as described below. Specifically, the structural information of the indoor unit 20 is, for example, the capacity of the indoor unit 20, which is the rated capacity of the indoor heat exchanger 22. The structural information of the indoor unit 20 may also be the length of the piping connecting the outdoor unit 10 and the indoor unit 20, as long as it reflects the installation conditions. Furthermore, the second distribution ratio is the total opening degree S ｔｏｔａｌ The ratio may be such that it is equally distributed to each indoor expansion valve. Details regarding the case where the second distribution ratio is a variable value will be explained in Embodiment 2.

[0056] Here, a positive correlation indicates that when variable A increases, variable B tends to increase as well. For example, if variable A is plotted on the horizontal axis and variable B on the vertical axis, and the relationship between the two variables is approximated by a linear function, a positive correlation is considered to exist if the slope of the function is positive. Therefore, in the case of "capacity of indoor unit 20," variable A corresponds to "capacity of indoor unit 20" and variable B corresponds to "the ratio assigned to that indoor unit 20," meaning that when the "capacity of indoor unit 20" is relatively large, the "ratio assigned to that indoor unit 20" also becomes larger. Similarly, in the case of "piping length from outdoor unit 10 to indoor unit 20," variable A corresponds to "piping length from outdoor unit 10 to indoor unit 20" and variable B corresponds to "the ratio assigned to that indoor unit 20," meaning that when the "piping length from outdoor unit 10 to indoor unit 20" is relatively long, the "ratio assigned to that indoor unit 20" also becomes larger.

[0057] Figure 6 is a flowchart showing the expansion valve control in the control processing device 31 of the refrigeration cycle device 1 according to Embodiment 1. The control processing device 31 controls the total opening degree S based on the control index deviation. ｔｏｔａｌ The control indicator is set (step S1). If the control indicator is the discharge temperature, the control indicator deviation is the discharge temperature deviation between the discharge temperature measured by the discharge temperature sensor 51 and the target discharge temperature. In step S1, the control processing device 31 sets the total opening degree S based on the discharge temperature deviation. ｔｏｔａｌSet it. The control processing device 31 sets the total opening degree S ｔｏｔａｌ Based on the first distribution ratio, it distributes the total indoor opening degree S ＩＤＵｓ and the bypass expansion valve opening degree S ＨＩＣ (Step S2). Subsequently, the control processing device 31 distributes the total indoor opening degree S ＩＤＵｓ Based on the second distribution ratio to each indoor expansion valve opening degree S ＩＤＵ (Step S3). The control processing device 31 controls the bypass expansion valve 15b to the bypass expansion valve opening degree S ＨＩＣ and controls each indoor expansion valve 21 to each indoor expansion valve opening degree S ＩＤＵ (Step S4).

[0058] Next, the operation of the above control will be described. First, as a comparative example, the configuration of the refrigerant circuit itself is the same as that of the first embodiment shown in FIG. 1, and an example in which the control method is different will be described. In the control of the comparative example, the opening degrees of each indoor expansion valve and the opening degree of the bypass expansion valve are controlled independently of each other. Also, in the control of the comparative example, the opening degrees of each indoor expansion valve are controlled independently of each other based on the air conditioning load of each indoor unit. Specifically, in the control of the comparative example, for each indoor unit, the opening degree of the indoor expansion valve is controlled so that the superheat degree at the outlet of the indoor heat exchanger becomes the target superheat degree. In a method of controlling the opening degrees of each indoor expansion valve and the opening degree of the bypass expansion valve independently of each other as in the control of the comparative example, the operations of each indoor expansion valve and the bypass expansion valve become disturbances to each other, which is a factor that degrades the control performance and reduces the operating efficiency.

[0059] In contrast, in the refrigeration cycle device 1, the refrigerant flow rate control unit 101 sets the total opening degree S ｔｏｔａｌ for controlling the refrigerant flow rate of the entire refrigerant circuit 10a, and distributes the total opening degree S ｔｏｔａｌ to the total indoor opening degree S ＩＤＵｓ and the bypass expansion valve opening degree S ＨＩＣ . Therefore, the refrigeration cycle device 1 can suppress the disturbance of the refrigerant flow in the entire refrigerant circuit 10a, suppress the degradation of the control performance, and improve the operating efficiency. Also, the refrigeration cycle device 1 distributes the total opening degree S ｔｏｔａｌ to the total indoor opening degree S ＩＤＵｓ and the bypass expansion valve opening degree S<00001When distributing the total cooling capacity Q, ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ The distribution is made in such a way that the relative magnitude relationship between them is maintained. As a result, the refrigeration cycle device 1 can suppress the disturbances that occur between the operation of each indoor expansion valve 21 and the bypass expansion valve 15b, thereby improving operating efficiency.

[0060] Furthermore, in the comparative example's control system, the opening degree of each indoor expansion valve is controlled independently of each other based on the respective air conditioning load of each indoor unit. In the comparative example's refrigeration cycle system using this method, for example, when the air conditioning load of one of the four indoor units fluctuates, the opening degree of the indoor expansion valve of that indoor unit changes, and the refrigerant flow rate through that indoor unit changes. In the comparative example's refrigeration cycle system, when the refrigerant flow rate through that indoor unit changes, the refrigerant flow rates through the other three indoor units are also affected and fluctuate, disturbing the superheating degree at the outlet of the indoor heat exchanger of the three indoor units. As a result, in the comparative example's refrigeration cycle system, the opening degrees of the indoor expansion valves of the three indoor units fluctuate, disturbing the overall refrigerant flow and causing a decrease in operating efficiency as it deviates from the optimal operating state. To recover from this state, the refrigerant flow of the entire refrigerant circuit can be adjusted slowly, but this method does not provide quick response.

[0061] In contrast, the refrigeration cycle device 1 has a total opening degree S on the indoor side. ＩＤＵｓ Each indoor expansion valve opening S ＩＤＵ To distribute the refrigerant, each indoor expansion valve 21 operates in coordination with one another. As a result, the refrigeration cycle device 1 can suppress turbulence in the refrigerant flow throughout the refrigerant circuit 10a, thereby improving operating efficiency. Furthermore, by suppressing turbulence in the refrigerant flow throughout the refrigerant circuit 10a, the refrigeration cycle device 1 can respond quickly to fluctuations in the air conditioning load. In other words, the refrigeration cycle device 1 can immediately reach an efficient state.

[0062] Furthermore, in the comparative example's control, it is necessary to independently set an appropriate initial opening degree for each indoor expansion valve and bypass expansion valve at the start of operation, and the design burden is large because the design guidelines are not clear.

[0063] In contrast, the refrigeration cycle device 1 can determine the first and second distribution ratios based on structural information, and therefore can quickly transition the operating state of the refrigerant circuit 10a to a highly efficient operating state without increasing the design load.

[0064] [Effects] The control device 30 of the refrigeration cycle device 1 of Embodiment 1 is a control device of the refrigeration cycle device 1 equipped with a refrigerant circuit 10a having a main circuit 14 and a bypass circuit 15. The main circuit 14 has a configuration in which a compressor 11, an outdoor heat exchanger 12, a high-pressure side passage 13a of an internal heat exchanger 13, at least one indoor expansion valve 21, and at least one indoor heat exchanger 22 are connected by refrigerant piping 1a. The bypass circuit 15 has a configuration in which a bypass pipe 15a and a bypass expansion valve 15b are provided. The bypass pipe 15a is a pipe that branches off from between the internal heat exchanger 13 and at least one indoor expansion valve 21 of the main circuit 14 and is connected to the suction side of the compressor 11 via the low-pressure side passage 13b of the internal heat exchanger 13. The bypass expansion valve 15b is provided in the bypass pipe 15a and is a valve that adjusts the flow rate of refrigerant passing through the low-pressure side passage 13b of the internal heat exchanger 13. The control device 30 of the refrigeration cycle device 1 includes a control processing device 31 that controls the opening degree of at least one indoor expansion valve 21 and a bypass expansion valve 15b. The control processing device 31 controls the total opening degree S, which is the expansion valve opening degree related to the refrigerant flow rate of the refrigerant circuit 10a. ｔｏｔａｌ The control processing device 31 sets the total cooling capacity Q. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ Based on a first distribution ratio set so that the relative magnitude relationship between and is maintained, the total opening degree S ｔｏｔａｌ The total opening angle S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ The expansion valve is controlled by distributing the energy to these components.

[0065] With the above configuration, the control device 30 controls the total opening degree S ｔｏｔａｌ Set the total opening degree S ｔｏｔａｌ The total opening angle S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣThe refrigerant is distributed to the following. As a result, the control device 30 can suppress disturbances in the flow of refrigerant throughout the refrigerant circuit 10a, suppress a decrease in control performance, and improve the operating efficiency of the refrigeration cycle device 1. Since the control device 30 controls the flow rate of refrigerant throughout the refrigerant circuit 10a in coordination with all expansion valves, it can achieve efficient operation even during transients.

[0066] The first distribution ratio is a fixed value, and the total cooling capacity Q is used to determine the first distribution ratio. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ This is determined based on the structural information of the corresponding heat exchanger.

[0067] With the above configuration, the control device 30 determines the first distribution ratio based on structural information, and therefore can quickly transition the operating state of the refrigerant circuit 10a to a highly efficient operating state without increasing the design load.

[0068] At least one indoor heat exchanger 22 includes a plurality of indoor heat exchangers 22, and at least one indoor expansion valve 21 includes a plurality of indoor expansion valves 21 each connected to the plurality of indoor heat exchangers 22. The control processing device 31 controls the total indoor opening S ＩＤＵｓ This is the opening degree of each of the multiple indoor expansion valves 21, which is the opening degree of multiple indoor expansion valves S. ＩＤＵ The power is distributed to control multiple indoor expansion valves 21.

[0069] With the above configuration, the control device 30 controls each indoor expansion valve 21 in conjunction, thereby suppressing the effects of interference and maintaining control performance. Furthermore, since the control device 30 controls the refrigerant flow rate of the entire refrigerant circuit 10a in coordination with all expansion valves, it can achieve efficient operation even during transients.

[0070] The control processing unit 31 controls the total opening degree S on the indoor side. ＩＤＵｓ Multiple indoor expansion valve openings S based on the second distribution ratio. ＩＤＵThe energy is distributed to the following: The second distribution ratio is a fixed value and is set to have a positive correlation with the structural information of multiple indoor units 20, each having multiple indoor heat exchangers 22 and multiple indoor expansion valves 21. The structural information may be the rated capacity of the indoor heat exchangers 22, or the length of the piping connecting the indoor units 20 and the outdoor units 10.

[0071] With the above configuration, the control device 30 controls each indoor expansion valve 21 in conjunction, thereby suppressing the effects of interference and maintaining control performance. Furthermore, since the control device 30 determines the second distribution ratio based on structural information, it can quickly transition the operating state of the refrigerant circuit 10a to a highly efficient operating state without increasing the design load.

[0072] [Embodiment 2] Embodiment 1 described the case where the first distribution ratio and the second distribution ratio are fixed values. Embodiment 2 describes the case where the first distribution ratio and the second distribution ratio are variable values ​​that change according to the operating conditions. Hereinafter, Embodiment 2 will be described mainly in terms of the configurations that differ from Embodiment 1, and configurations not described in Embodiment 2 are the same as in Embodiment 1.

[0073] Figure 7 is a schematic diagram showing an example of a refrigerant circuit 10a of a refrigeration cycle device 1 according to Embodiment 2. The refrigeration cycle device 1 according to Embodiment 2 has a configuration in which various sensors are added to the refrigeration cycle device 1 of Embodiment 1 shown in Figure 1. The refrigeration cycle device 1 has an outdoor heat exchanger liquid pipe temperature sensor 52 and an internal heat exchanger liquid temperature sensor 53. The refrigeration cycle device 1 has indoor heat exchanger liquid pipe temperature sensors 54a, 54b, 54c and 54d, indoor heat exchanger suction temperature sensors 55a, 55b, 55c and 55d, indoor heat exchanger discharge humidity sensor (not shown), and indoor heat exchanger gas pipe temperature sensors 56a, 56b, 56c and 56d. The refrigeration cycle device 1 further has a compressor suction temperature sensor 57, an internal heat exchanger gas temperature sensor 58, a high-pressure sensor 61, and a low-pressure sensor 62.

[0074] Hereafter, unless otherwise distinguished, the indoor heat exchanger liquid pipe temperature sensors 54a, 54b, 54c, and 54d will be collectively referred to as the indoor heat exchanger liquid pipe temperature sensor 54. Similarly, unless otherwise distinguished, the indoor heat exchanger suction temperature sensors 55a, 55b, 55c, and 55d will be collectively referred to as the indoor heat exchanger suction temperature sensor 55. Unless otherwise distinguished, the indoor heat exchanger gas pipe temperature sensors 56a, 56b, 56c, and 56d will be collectively referred to as the indoor heat exchanger gas pipe temperature sensor 56.

[0075] The outdoor heat exchanger liquid pipe temperature sensor 52 measures the temperature of the liquid-side piping of the outdoor heat exchanger 12. The internal heat exchanger liquid temperature sensor 53 measures the temperature of the liquid refrigerant flowing out from the high-pressure side flow path 13a of the internal heat exchanger 13. The indoor heat exchanger liquid pipe temperature sensor 54 measures the temperature of the liquid-side piping of the indoor heat exchanger 22. The indoor heat exchanger suction temperature sensor 55 is located at the air inlet of the indoor heat exchanger 22 and measures the air intake temperature. The indoor heat exchanger outlet humidity sensor (not shown) is located at the air outlet of the indoor heat exchanger 22 and measures the air outlet humidity.

[0076] The indoor heat exchanger gas pipe temperature sensor 56 measures the temperature of the gas-side piping of the indoor heat exchanger 22. The compressor suction temperature sensor 57 is located on the suction side of the compressor 11 and measures the temperature of the refrigerant being drawn into the compressor 11. The internal heat exchanger gas temperature sensor 58 measures the temperature of the gaseous refrigerant flowing out of the internal heat exchanger 13. The high-pressure sensor 61 is located on the discharge side of the compressor 11 and measures the discharge pressure of the refrigerant. The low-pressure sensor 62 is located on the suction side of the compressor 11 and measures the suction pressure of the refrigerant.

[0077] The above is an example of additional sensors; it is not necessary to install all of them, and other sensors may be added. The refrigeration cycle device 1 can be configured by selecting the necessary sensors as needed in the following explanation. Sensor information measured by the various sensors is input to the control device 30.

[0078] Figure 8 is a block diagram showing an example of the configuration of the control processing unit 31 of the refrigeration cycle device 1 according to Embodiment 2, specifically the part that controls the indoor expansion valve 21 and the bypass expansion valve 15b. The control processing unit 31 of Embodiment 2 has a capacity calculation unit 104 in addition to the configuration of Embodiment 1 shown in Figure 5. Sensor information from the various sensors is input to the capacity calculation unit 104 and the second distributor 103, respectively. The capacity calculation unit 104 calculates the total cooling capacity Q based on the sensor information from the various sensors. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ The and are calculated sequentially and output to the first distributor 102.

[0079] The first distributor 102 calculates the total cooling capacity Q from the capacity calculation unit 104. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ The first distribution ratio is determined based on the above. The first distributor 102 determines the first distribution ratio based on the state information that changes during operation obtained from the various sensors, etc. In other words, the first distributor 102 changes the first distribution ratio according to the operating conditions. The first distribution ratio is updated at each preset control interval. The processing of the first distributor 102 after determining the first distribution ratio is the same as in Embodiment 1, and the first distributor 102 determines the total opening degree S based on the first distribution ratio. ｔｏｔａｌ The total opening angle S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ It is distributed and output to [the other party].

[0080] The second distributor 103 determines the second distribution ratio according to the cooling capacity of each of the indoor heat exchangers 22, which changes during operation. The second distributor 103 determines the second distribution ratio based on the state information that changes during operation, obtained from the various sensors mentioned above. In other words, the second distributor 103 changes the second distribution ratio according to the operating conditions. The second distribution ratio is updated at preset control intervals. The processing of the second distributor 103 after determining the second distribution ratio is the same as in Embodiment 1, and the second distributor 103 determines the total indoor opening degree S based on the second distribution ratio. ＩＤＵｓ Each indoor expansion valve opening S ＩＤＵ It is distributed and output.

[0081] (First distribution ratio) The first distributor 102 receives the total cooling capacity Q calculated by the capacity calculation unit 104. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ The first distribution ratio is determined based on this.

[0082] (Total cooling capacity Q) ＩＤＵｓ (Calculation of) Cooling capacity Q ＩＤＵ This is measured or estimated using the following state information: Cooling capacity Q ＩＤＵ The status information is determined based on at least one of the following values: the rotational speed of the indoor fan 23 (fan airflow), the intake temperature of the indoor heat exchanger, the intake humidity of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, the outlet humidity of the indoor heat exchanger, the evaporation temperature of the indoor heat exchanger 22, the rotational speed of the compressor, the refrigerant flow rate of the indoor heat exchanger 22, the enthalpy of the indoor heat exchanger inlet, and the enthalpy of the indoor heat exchanger outlet.

[0083] Cooling capacity Q ＩＤＵ This can be measured, for example, based on the measurement results of intake temperature, intake humidity, outlet temperature, and outlet humidity, as well as equipment specifications such as the rotation speed of the indoor fan 23 (fan airflow), the area of ​​the indoor heat exchanger 22, and the heat exchange efficiency. Furthermore, the cooling capacity Q can be measured. ＩＤＵ This is not limited to values ​​precisely measured based on sensor information, but can also be estimated from intake temperature, outlet temperature, and fan speed (fan airflow).

[0084] Also, cooling capacity Q ＩＤＵ The cooling capacity Q may be estimated from the refrigerant flow rate and the enthalpy of the inlet and outlet of the indoor heat exchanger 22. The refrigerant flow rate may be calculated from the rotational speed, stroke volume, and suction density of the compressor 11, or it may be estimated based on the opening degree of the indoor expansion valve and the pressure before and after the indoor expansion valve. The suction density can be estimated from the suction pressure measured by the low-pressure sensor 62 or from sensor information such as a temperature sensor installed on the indoor heat exchanger 22. Alternatively, the cooling capacity Q ＩＤＵ This can also be estimated from the difference between the intake temperature measured by the indoor heat exchanger intake temperature sensor 55 and the evaporation temperature of the indoor heat exchanger 22, and from the heat exchanger performance. Cooling capacity Q ＩＤＵThis can be updated as needed as a function of the rotation speed of the indoor fan 23. The capacity calculation unit 104 calculates the cooling capacity Q of each indoor unit 20. ＩＤＵ The sum of these results in the total cooling capacity Q. ＩＤＵｓ Calculate.

[0085] (Total cooling capacity Q) ＩＤＵｓ Example of calculation: Total cooling capacity Q ＩＤＵｓ This can be calculated, for example, using equation (3) below. Note that each indoor heat exchanger 22 is numbered 1 to 4.

[0086]

[0087] Here, AKM: Variable relating to the heat exchanger performance of the indoor heat exchanger 22. ΔtM: Temperature difference between the media that exchange heat in the indoor heat exchanger 22. Here, the temperature difference index between the refrigerant and air i: Number assigned to the indoor heat exchanger 22.

[0088] ΔtM is calculated using equation (4) below.

[0089]

[0090] Here, Tr: Intake temperature of the indoor heat exchanger 22 ET: Heat exchanger temperature of the indoor heat exchanger 22, i.e., evaporation temperature

[0091] Tr is the intake temperature measured by the indoor heat exchanger intake temperature sensor 55. ET may be detected by a temperature sensor installed on the indoor unit 20, or a value obtained by converting the intake pressure measured by the low-pressure sensor 62 to the saturation temperature may be used.

[0092] AKM may be determined from the equipment specifications or based on the following formula (5). Formula (5) is used to determine AKM as a reference value from the test results. base Please request AKM base This formula calculates AKM by correcting it to be proportional to the airflow of the indoor fan 23.

[0093]

[0094] Here, V(i): Rotational speed of the indoor fan 23 during actual operation V base(i): Rotational speed of the indoor fan 23 at the reference point. The reference point is AKM base These are the test conditions that were sought.

[0095] Based on the above, the capacity calculation unit 104 calculates the cooling capacity Q of each indoor unit 20. ＩＤＵ Calculate the total cooling capacity Q ＩＤＵｓ The total cooling capacity Q obtained from the above calculation is calculated. ＩＤＵｓ This does not take latent heat into account, but if latent heat is taken into account, the total cooling capacity Q can be calculated more precisely. ＩＤＵｓ The capacity calculation unit 104 calculates the total cooling capacity Q considering latent heat. ＩＤＵｓ When estimating the total cooling capacity Q, use the measurement results of the indoor heat exchanger outlet humidity sensor (not shown). ＩＤＵｓ We just need to estimate that.

[0096] (Internal heat exchange capacity Q ＨＩＣ (Calculation of) Internal heat exchange capacity Q ＨＩＣ This is determined using the following state information: Internal heat exchange capacity Q ＨＩＣ The state information is determined based on at least one of the following values: the refrigerant flow rate of the internal heat exchanger 13, the compressor rotation speed, the liquid pipe temperature of the outdoor heat exchanger, and the evaporation temperature of the internal heat exchanger 13. This state information may be measured values ​​or estimated values.

[0097] (Internal heat exchange capacity Q ＨＩＣ Specific example of calculation: Internal heat exchange capacity Q ＨＩＣ This can be calculated using the following equation (6).

[0098]

[0099] Here, AKS: Variables relating to the heat exchanger performance of the internal heat exchanger 13 ΔtS: Temperature difference between the refrigerants that exchange heat in the internal heat exchanger 13

[0100] ΔtS is calculated using equation (7) below.

[0101]

[0102] Here, T: Outdoor heat exchanger liquid pipe temperature, the temperature measured by the outdoor heat exchanger liquid pipe temperature sensor 52; ET: Heat exchanger temperature of the indoor heat exchanger 22, i.e., evaporation temperature.

[0103] AKS may be determined as a fixed value from the equipment specifications, or as a variable value that is updated as needed based on equation (8) below. Equation (8) is used to determine AKS as a reference value from test results. base Please request AKS base This formula calculates AKS by correcting it so that it is proportional to the rotational speed of the compressor 11 or the refrigerant flow rate of the main circuit 14.

[0104]

[0105] Here, F(i): Rotational speed of the compressor 11 or refrigerant flow rate of the main circuit 14 during actual operation F base (i): Rotational speed of compressor 11 or refrigerant flow rate of main circuit 14 at the reference point.

[0106] Based on the above, the capacity calculation unit 104 calculates the internal heat exchange capacity Q based on the status information during actual operation. ＨＩＣ Calculate.

[0107] The first distributor 102 has a total cooling capacity Q calculated as described above. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ The first distribution ratio is determined based on the above. The first distributor 102 has a total opening degree S ｔｏｔａｌ When distributing, as mentioned above, it is not necessary to maintain a strictly proportional relationship, and the total cooling capacity Q ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ The first distribution ratio should be determined on the condition that the relative magnitude relationship with the other is maintained.

[0108] (Second distribution ratio) The second distributor 103 determines the second distribution ratio, for example, as shown in (a) to (d) below.

[0109] (a) Based on the predicted actual load of each indoor unit 20, the ratio is increased if the actual load is greater than the assumed load, and decreased if it is smaller than the assumed load. (b) Based on the difference between the actual intake temperature and the set temperature of each indoor unit 20, the ratio is increased as the difference is larger, and the ratio is decreased as the difference is smaller. (c) Based on the degree of superheating at the outlet of each indoor heat exchanger 22, the ratio is increased as the degree of superheating is greater, and the ratio is decreased as the degree of superheating is smaller. This is to avoid the decrease in heat exchange efficiency and operating efficiency that occurs as the degree of superheating increases. (d) Based on the degree of superheating at the outlet of each indoor heat exchanger 22, the ratio may be increased as the value obtained by subtracting the target degree of superheating from the degree of superheating is larger, and the ratio may be decreased as the value is smaller. The target degree of superheating may be a constant value to increase operating efficiency, or it may be a value set to be larger when the actual load is small and smaller when the actual load is large in order to correspond to the actual load.

[0110] The above (a) is supplemented below. Consider the case where the actual load is greater than the assumed load for indoor units 20a and 20b, and the actual load is smaller than the assumed load for indoor units 20c and 20d. In this case, the second distributor 103 has a total indoor opening degree S. ＩＤＵｓ The indoor expansion valve opening degree S ＩＤＵａ S ＩＤＵｂ S ＩＤＵｃ and S ＩＤＵｄ When distributing the power, the second distribution ratio corresponding to indoor units 20a and 20b is increased compared to the previous value, and the second distribution ratio corresponding to indoor units 20c and 20d is decreased compared to the previous value.

[0111] The above (b) is supplemented below. Consider the case where the indoor units 20a, 20b, 20c, and 20d are numbered in descending order of the difference between the actual intake temperature and the set temperature of each indoor unit 20. In this case, the second distributor 103 determines the allocation ratio from the largest value to the smallest value in the order of indoor expansion valves 21a, 21b, 21c, and 21d. The actual intake temperature is the intake temperature measured by the indoor heat exchanger intake temperature sensor 55. The distribution ratio can be determined in the same way for (c) to (d) above.

[0112] The refrigeration cycle device 1 has a total cooling capacity Q for determining the first distribution ratio. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ When the value is set to a variable value based on the operating state information, it can respond to situations that change during actual operation, and the operating state of the refrigerant circuit 10a can be quickly transitioned to a highly efficient operating state. In addition, the refrigeration cycle device 1 has a total cooling capacity Q for determining the first distribution ratio. ＩＤＵｓ and internal heat exchange capacity Q ＨＩＣ When the total cooling capacity Q is set to a variable value based on the operating state information, the total cooling capacity Q is set to a variable value based on the operating state information when designing the refrigerant circuit 10a. ＩＤＵｓ There is no need to decide on this. Therefore, the refrigeration cycle device 1 can quickly transition the operating state of the refrigerant circuit 10a to a highly efficient operating state without increasing the design load.

[0113] [Effects] The control device 30 of the refrigeration cycle device 1 in Embodiment 2 provides the same effects as in Embodiment 1, and further provides the following effects because the first and second distribution ratios are variable values ​​that change according to the operating conditions. The refrigeration cycle device 1 in Embodiment 2 controls the expansion valves based on the first distribution ratio set based on state information that changes during operation, so it can perform appropriate expansion valve control that reflects the actual operating conditions and realize highly accurate and efficient operation. In addition, the refrigeration cycle device 1 controls each indoor expansion valve based on the second distribution ratio set according to the operating conditions, so it can suppress disturbances such as fluctuations in the heat load processed by each indoor unit 20, and maintain high comfort and a high power consumption reduction effect.

[0114] [Embodiment 3] Embodiment 3 describes a method for adjusting the first distribution ratio in a feedback manner. The following description will focus on the configurations in Embodiment 3 that differ from those in Embodiments 1-2, and configurations not described in Embodiment 3 are the same as those in Embodiments 1-2.

[0115] Figure 9 is a block diagram showing an example of the configuration of the part that controls the indoor expansion valve 21 and the bypass expansion valve 15b in the control processing device 31 of the refrigeration cycle device 1 according to Embodiment 3. The control processing device 31 of Embodiment 3 adjusts the first distribution ratio in a feedback manner according to the operating conditions. In addition to the configuration of Embodiment 2 shown in Figure 8, the control processing device 31 of Embodiment 3 has a correction coefficient adjustment unit 105. The correction coefficient adjustment unit 105 controls the superheating degree SH, which will be described later. Ａ SH Ｂ SH Ｃ The total indoor opening degree S is based on at least two of the following: ＩＤＵｓ Correction coefficient cm and bypass expansion valve opening S ＨＩＣ The correction coefficient cs is adjusted and output to the first distributor 102.

[0116] The first distributor 102 adjusts the first distribution ratio based on the correction coefficient cm and correction coefficient cs output from the correction coefficient adjustment unit 105, and distributes the total indoor opening degree S based on the adjusted first distribution ratio. ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ The refrigeration cycle device 1 outputs the total indoor opening degree S output from the first distributor 102. ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ By controlling the indoor expansion valve 21 and the bypass expansion valve 15b based on this, performance degradation caused by negative factors described later is suppressed, and highly efficient operation is achieved.

[0117] In actual operation in a real installation environment, it is difficult to maintain efficient operation due to the effects of factors such as uneven distribution of refrigerant in the heat exchanger, wind speed disturbances, sensor errors, and errors in the mathematical modeling. The control processing device 31 takes these negative factors that affect efficient operation into consideration and adjusts the first distribution ratio to maintain efficient operation. By adjusting the first distribution ratio, the control processing device 31 consequently corrects the opening degree of the bypass expansion valve 15b and adjusts the refrigerant flow rate through the bypass circuit 15.

[0118] The first distributor 102 adjusts the first distribution ratio using the correction coefficient cm and the correction coefficient cs, thereby adjusting the total opening degree S on the indoor side. ＩＤＵｓ and bypass expansion valve opening S ＨＩＣCorrect and output.

[0119] The first distributor 102 has a total indoor opening degree S obtained by equation (1) above. ＩＤＵｓ This is corrected using the correction coefficient cm in the following equation (9). The first distributor 102 is corrected by the bypass expansion valve opening S obtained in the above equation (2). ＨＩＣ This is corrected using the correction coefficient cs in the following equation (10). In equation (9), km is the total opening degree S on the indoor side in the first distribution ratio after adjustment. ＩＤＵｓ This corresponds to the ratio to which it is distributed. In equation (10), ks is the bypass expansion valve opening S in the adjusted first distribution ratio. ＨＩＣ This corresponds to the proportion allocated to each.

[0120]

[0121]

[0122] However, the ratio km and ratio ks satisfy the constraint that equation (11) below must be satisfied in order to maintain the total opening.

[0123]

[0124] The adjustment of the correction coefficient cm and correction coefficient cs will be explained below. The correction coefficient cm and correction coefficient cs are set with the aim of achieving high-efficiency operation. High-efficiency operation is a state in which the intake dryness of the compressor 11 is 1 or more, and the intake superheat of the compressor 11 is a relatively small superheat target value. A relatively small superheat target value is a value within the range of greater than 0 and 10K or less. The upper limit of the superheat target value is not limited to 10K, but can be set appropriately according to the system. For example, the superheat target value can be set to 5K.

[0125] The refrigeration cycle device 1 controls the discharge temperature to a target discharge temperature by adjusting the overall expansion valve opening using the refrigerant flow control unit 101, and controls the suction superheat of the compressor 11 to a relatively small value. By controlling the discharge temperature to a target discharge temperature and controlling the suction superheat of the compressor 11 to a relatively small value, the refrigeration cycle device 1 can operate each element with high efficiency by simultaneously controlling each superheat by adjusting the correction coefficient cm and correction coefficient cs described below. In order to achieve the above, it is necessary that the target values ​​of each superheat and the target discharge temperature are determined without contradiction.

[0126] Referring to Figure 3, the state of high-efficiency operation is the state in which the superheating degree at point C, after the merging of points A and B, reaches the target superheating degree. Here, the superheating degree at point A is the superheating degree at the outlet of the low-pressure side flow path 13b of the internal heat exchanger 13. The superheating degree at point B is the superheating degree after the merging of the outlets of each indoor heat exchanger 22. The superheating degree at point C is the superheating degree after the merging of points A and B, and is the suction superheating degree of the compressor 11.

[0127] The correction coefficient adjustment unit 105 adjusts the correction coefficient so that the superheating levels at points A, B, and C are equal to each other and approach the target superheating level. More specifically, the correction coefficient adjustment unit 105 adjusts the correction coefficient based on the superheating levels of at least two of points A, B, and C so that the correction coefficient corresponding to the point with the higher superheating level among those two points becomes larger than the current correction coefficient.

[0128] Here, we will explain the case where the correction coefficient is adjusted based on the degree of superheating at points A and B among points A, B, and C. In this case, the correction coefficient adjustment unit 105 adjusts the degree of superheating SH at point A. Ａ The degree of superheating at point B is SH Ｂ Toga, "0 < SH Ａ =SH Ｂ The correction coefficient is adjusted with the goal of satisfying the "superheating target value". Ａ =SH Ｂ "= Superheating target value" refers to SH Ａ and SH Ｂ This means that the two values ​​are the same, and both are greater than zero, which corresponds to the target superheating value.

[0129] SH Ａ > SH Ｂ If the relationship exists, the correction coefficient adjustment unit 105 adjusts the superheating degree SH when the refrigerant flow rate to the internal heat exchanger 13 increases. Ａ The superheating degree SH decreases. Ａ SH Ｂ To approach this, adjust the correction coefficient cs corresponding to point A to a value greater than its current value. Conversely, SH Ａ <SH Ｂ If the relationship exists, the correction coefficient adjustment unit 105 adjusts the superheating degree SH when the refrigerant flow rate to the indoor heat exchanger 22 increases. Ｂ The SH Ａ To approach this value, the correction coefficient cm corresponding to point B is set to a value greater than the current value. In other words, the correction coefficient adjustment unit 105 adjusts the correction coefficient as follows.

[0130] SH Ａ > SH Ｂ Increase the correction factor cs. SH Ａ <SH Ｂ Increase the correction factor cm.

[0131] However, since the first distribution ratio must maintain the constraint of equation (11) above, if one of cs and cm is changed, the other is adjusted accordingly. Here, the initial values ​​of cs and cm are 1. An initial value of 1 means no correction. At the start of operation, cs and cm are set to 1.

[0132] Let me explain with a concrete example. For example, SH Ａ = 7, SH Ｂ = 5, if the superheating target value is 5, SH Ａ > SH Ｂ Therefore, the correction coefficient adjustment unit 105 adjusts the correction coefficient cs to a value greater than the current value as described above. Here, if the coefficient adjustment rate is, for example, 5%, the correction coefficient adjustment unit 105 adjusts the correction coefficient cs based on the following equation (12) so that the correction coefficient cs becomes 5% greater than the current value. Then, in order to maintain the constraint of the above equation (11), the correction coefficient adjustment unit 105 sets the correction coefficient cm based on the following equation (13).

[0133]

[0134]

[0135] By adjusting the correction coefficient cm to a value greater than the current value in this way, the refrigerant flow rate through the internal heat exchanger 13 increases, and the superheating degree SH increases. Ａ The SH Ｂ As it approaches this value, the suction superheating of the compressor 11 approaches the superheating target value of 5.

[0136] The correction coefficients cs and cm may also be adjusted using equations (14) and (15) below. The adjustment method using equations (14) and (15) utilizes the characteristic that when one of cs and cm decreases, the other increases.

[0137]

[0138] As described above, the control processing device 31 adjusts the first distribution ratio in a feedback manner by adjusting the correction coefficient cm and the correction coefficient cs based on the degree of superheating at the outlets of the low-pressure side flow path 13b of the internal heat exchanger 13 and the indoor side heat exchanger 22, respectively.

[0139] The correction coefficient adjustment unit 105 adjusts the correction coefficient based on the superheating degree of at least two of the two points A, B, and C measured during operation, so that the correction coefficient corresponding to the point with the larger superheating degree among those two points becomes larger than its current value. In other words, if the "correction coefficient corresponding to the point with the larger superheating degree among those two points" is cm, cm is adjusted to become larger than its current value, and cs is adjusted to satisfy the constraint of equation (11) above. Conversely, if the "correction coefficient corresponding to the point with the larger superheating degree among the two points" is cs, cs is adjusted to become larger than its current value, and cm is adjusted to satisfy the constraint of equation (11) above.

[0140] The first distributor 102 uses the adjusted correction coefficient cm and correction coefficient cm to determine the total opening S based on equations (9) and (10) above. ｔｏｔａｌ Total opening angle S on the indoor side ＩＤＵｓ and bypass expansion valve opening S ＨＩＣIt is distributed to and. In equations (9) and (10) at this time, Q ＩＤＵｓ and Q ＨＩＣ This may be a fixed value as in Embodiment 1, or a variable value as in Embodiment 2. The first distributor 102 distributes the total indoor opening S ＩＤＵｓ and bypass expansion valve opening S ＨＩＣ Outputs.

[0141] The superheating levels of "at least two of points A, B, and C measured during operation" are values ​​affected by the negative factors mentioned above. Therefore, the refrigeration cycle device 1 can adjust the first distribution ratio by correcting the correction coefficient based on these values, thereby suppressing performance degradation caused by the negative factors and achieving efficient operation in a wide range of situations.

[0142] Note that while the coefficient adjustment rate is stated as 5% above, this is merely an example and is not limited to this value. The coefficient adjustment rate may be a constant value, or SH Ａ and SH Ｂ It may be changed according to the difference between the two. For example, the correction coefficient adjustment unit 105 is SH Ａ > SH Ｂ Therefore, as the difference increases, the coefficient adjustment rate may be increased, and the correction coefficient cs may be adjusted to a larger value.

[0143] Here, SH A > SH B When the relationship is such that the correction coefficient is adjusted, SH Ａ SH Ｂ Let's consider the case where, as a result of approaching the target, the convergence superheating after approaching the target value exceeds the target superheating value. This situation is, for example, SH B This occurs when the superheating degree exceeds the superheating target value before the correction coefficient is adjusted. When the converged superheating degree exceeds the superheating target value, the actual discharge temperature measured by the discharge temperature sensor 51 becomes higher than the target discharge temperature. This is because the target discharge temperature is designed based on the superheating target value. When the discharge temperature is higher than the target discharge temperature, the refrigerant flow control unit 101 adjusts the total opening S ｔｏｔａｌ Increase the total opening degree S. ｔｏｔａｌAs this increases, the convergence of superheating decreases and reaches the target superheating value. In other words, the control processing device 31 adjusts the correction coefficient by the correction coefficient adjustment unit 105 to bring the superheating values ​​of points A, B, and C closer together, and the refrigerant flow rate control unit 101 adjusts the total opening S ｔｏｔａｌ By setting this, the convergence of superheating is brought closer to the target superheating value.

[0144] Also, SH A > SH B When the relationship is such that the correction coefficient is adjusted, SH Ａ SH Ｂ As a result of bringing it closer to the target value, even if the convergence superheating is below the target superheating value, the correction coefficient and the total opening S are also corrected. ｔｏｔａｌ Through this control, the convergent superheat reaches the superheat target value. If the convergent superheat is below the superheat target value, the discharge temperature will be lower than the target discharge temperature. For this reason, the refrigerant flow control unit 101 controls the total opening S ｔｏｔａｌ Reduce the total opening degree S. ｔｏｔａｌ As this decreases, the convergence of superheating increases, reaching the target superheating value.

[0145] In the above explanation, for the sake of clarity, it was assumed that the superheating levels at points A, B, and C converge before the converged superheating level approaches the target superheating value. However, in actual operation, the superheating levels at points A, B, and C may converge to the target superheating value while simultaneously approaching each other.

[0146] Also, here, SH Ａ > SH Ｂ I have explained an example of the case where the inequality sign is reversed, that is, SH Ａ <SH Ｂ In this case as well, cs and cm can be adjusted using the same formulas. Specifically, cs and cm can be adjusted using the formulas obtained by swapping cs and cm in formulas (12) to (15) above. Note that the adjustment method is not limited to the above, and the amount of adjustment may vary depending on the magnitude of the error in each superheating degree.

[0147] Furthermore, although this explanation describes the case where at least two of points A, B, and C are points A and B, it may also be points A and C, or points B and C. In other words, the correction coefficient adjustment unit 105 adjusts the superheating degree SH of point A. Ａ and the degree of superheating SH at point C Ｃ The correction coefficient may be adjusted based on the superheating degree SH of point B. Ｂ and the degree of superheating SH at point C Ｃ The correction coefficient may be adjusted based on the above. The method for adjusting the correction coefficient in these cases is the same as above, so a detailed explanation will be omitted, but in short, it is as follows.

[0148] Superheating degree SH at point A Ａ and the degree of superheating SH at point C Ｃ When adjusting the correction coefficient based on 0 < SH Ａ =SH Ｃ = The correction coefficient should be adjusted with the goal of meeting the target superheating value. In this case, the correction coefficient adjustment unit 105 adjusts the correction coefficient as follows.

[0149] SH Ａ > SH Ｃ Increase the correction factor cs. SH Ａ <SH Ｃ Increase the correction factor cm.

[0150] Superheating degree SH at point B Ｂ and the degree of superheating SH at point C Ｃ When adjusting the correction coefficient based on 0 < SH Ｂ =SH Ｃ = The correction coefficient should be adjusted with the goal of meeting the target superheating value. In this case, the correction coefficient adjustment unit 105 adjusts the correction coefficient as follows.

[0151] SH Ｂ > SH Ｃ Increase the correction factor cm. SH Ｂ <SH Ｃ Increase the correction coefficient cs.

[0152] The refrigeration cycle device 1 uses the degree of superheating as the control target when adjusting the correction coefficient, but the control target is not limited to the degree of superheating. It may also be, for example, the degree of subcooling at the outlet of the outdoor heat exchanger 12 or the outlet of the high-pressure side flow path 13a of the internal heat exchanger 13. In this case, the refrigeration cycle device 1 should adjust the first distribution ratio so that the opening of the bypass expansion valve 15b increases if the degree of subcooling at the outlet of the outdoor heat exchanger 12 or the degree of subcooling at the outlet of the high-pressure side flow path 13a of the internal heat exchanger 13 is greater than the threshold set for each.

[0153] If the degree of subcooling at the outlet of the outdoor heat exchanger 12, or the degree of subcooling at the outlet of the high-pressure side flow path 13a of the internal heat exchanger 13, is greater than the threshold set for each, it is considered that there is an excess of refrigerant in the outdoor unit 10. Therefore, the refrigeration cycle device 1 can improve the condition of excess refrigerant in the outdoor unit 10 by adjusting the first distribution ratio as described above, thereby increasing the refrigerant flow rate in the bypass circuit 15 and decreasing the flow rate toward each indoor heat exchanger 22. Specifically, the refrigeration cycle device 1 adjusts the first distribution ratio by making the correction coefficient cs larger than the current value. The adjustment method in this case is the same as described above, so the explanation is omitted.

[0154] [Effects] The control device 30 of the refrigeration cycle device 1 in Embodiment 3 provides the same effects as in Embodiments 1-2, and also adjusts the first distribution ratio according to the actual operation, thereby suppressing performance degradation caused by the negative factors mentioned above and achieving high-efficiency operation in a wide range of situations.

[0155] [Modifications] The descriptions herein are merely illustrative, and modifications are possible to the extent that the effects of the disclosure are not lost. For example, the refrigerant circuit 10a may include a liquid reservoir such as an accumulator or receiver, or a four-way valve for switching between heating and cooling. Alternatively, the refrigerant circuit 10a may be equipped with a bypass circuit, expansion valve, or solenoid valve to the extent that it does not significantly affect the function of the refrigeration cycle.

[0156] 1 Refrigeration cycle unit, 1a Refrigerant piping, 10 Outdoor unit, 10a Refrigerant circuit, 11 Compressor, 12 Outdoor heat exchanger, 13 Internal heat exchanger, 13a High-pressure side flow path, 13b Low-pressure side flow path, 14 Main circuit, 15 Bypass circuit, 15a Bypass piping, 15b Bypass expansion valve, 20 Indoor unit, 20a Indoor unit, 20b Indoor unit, 20c Indoor unit, 20d Indoor unit, 21 (21a, 21b, 21c, 21d) Indoor expansion valve, 22 (22a, 22b, 22c, 22d) Indoor heat exchanger, 23 (23a, 23b, 23c, 23d) Indoor fan, 30 Control device, 31 Control processing device, 32 Timing device, 33 Memory device, 51 Discharge temperature sensor, 52 Outdoor heat exchanger liquid pipe temperature sensor, 53 Internal heat exchanger liquid temperature sensor, 54 (54a, 54b, 54c, 54d) Indoor heat exchanger liquid pipe temperature sensor, 55 (55a, 55b, 55c, 55d) Indoor heat exchanger suction temperature sensor, 56 (56a, 56b, 56c, 56d) Indoor heat exchanger gas pipe temperature sensor, 57 Compressor suction temperature sensor, 58 Internal heat exchanger gas temperature sensor, 61 High pressure sensor, 62 Low pressure sensor, 101 Refrigerant flow control unit, 102 First distributor, 103 Second distributor, 104 Capacity calculation unit, 105 Correction coefficient adjustment unit.

Claims

1. A control device for a refrigeration cycle system comprising a refrigerant circuit having: a main circuit connecting a compressor, an outdoor heat exchanger, a high-pressure side passage of an indoor heat exchanger, at least one indoor expansion valve, and at least one indoor heat exchanger with refrigerant piping; a bypass piping branching from the main circuit between the indoor heat exchanger and the at least one indoor expansion valve and connected to the suction side of the compressor via the low-pressure side passage of the indoor heat exchanger; and a bypass circuit provided in the bypass piping and equipped with a bypass expansion valve that adjusts the flow rate of refrigerant passing through the low-pressure side passage of the indoor heat exchanger, wherein the control device comprises a control processing unit that controls the opening degree of the at least one indoor expansion valve and the bypass expansion valve, and the control processing unit is A control device for a refrigeration cycle system that controls the expansion valve by setting a total opening, which is the expansion valve opening degree related to the refrigerant flow rate of the refrigerant circuit, and distributing the total opening degree to a total opening, which is the sum of the opening degrees of the at least one indoor expansion valves, and a bypass expansion valve opening, which is the opening degree of the bypass expansion valve, based on a first distribution ratio set to maintain a relative magnitude relationship between the total cooling capacity, which is the sum of the cooling capacities of the at least one indoor heat exchanger, and the internal heat exchange capacity, which is the heat exchange capacity of the internal heat exchanger.

2. The control device for a refrigeration cycle device according to claim 1, wherein the first distribution ratio is a fixed value, and the total cooling capacity and the internal heat exchange capacity for determining the first distribution ratio are determined based on structural information of the corresponding heat exchangers.

3. The control device for a refrigeration cycle apparatus according to claim 2, wherein the structural information is the rated capacity of the heat exchanger.

4. The control device for a refrigeration cycle apparatus according to claim 1, wherein the first distribution ratio is a variable value that changes according to the operating conditions, and the control processing device changes the first distribution ratio based on the total cooling capacity and the internal heat exchange capacity that change based on the state information of the refrigerant circuit during operation.

5. The control device for a refrigeration cycle device according to claim 4, wherein the state information for determining the cooling capacity of the at least one indoor heat exchanger is at least one of the following: rotational speed of an indoor fan that blows air to the at least one indoor heat exchanger, indoor heat exchanger intake temperature, indoor heat exchanger intake humidity, indoor heat exchanger outlet temperature, indoor heat exchanger outlet humidity, evaporation temperature of the indoor heat exchanger, compressor rotational speed, refrigerant flow rate, indoor heat exchanger inlet enthalpy, and indoor heat exchanger outlet enthalpy.

6. The control device for a refrigeration cycle device according to claim 4 or claim 5, wherein the state information for determining the internal heat exchange capacity is at least one of the following: refrigerant flow rate, compressor rotation speed, outdoor heat exchanger liquid pipe temperature, and evaporation temperature of the internal heat exchanger.

7. The control device for a refrigeration cycle device according to any one of claims 1 to 6, wherein the at least one indoor heat exchanger includes a plurality of indoor heat exchangers, the at least one indoor expansion valve includes a plurality of indoor expansion valves each connected to the plurality of indoor heat exchangers, and the control processing device controls the plurality of indoor expansion valves by distributing the total indoor opening to a plurality of indoor expansion valve openings which are the openings of the plurality of indoor expansion valves.

8. The control device for a refrigeration cycle device according to claim 7, wherein the control processing device distributes the total indoor opening degree to the multiple indoor expansion valve opening degrees based on a second distribution ratio, and the second distribution ratio is a fixed value and is set to have a positive correlation with the structural information of the multiple indoor units having the multiple indoor heat exchangers and the multiple indoor expansion valves.

9. The control device for a refrigeration cycle device according to claim 8, wherein the structural information of the plurality of indoor units is the rated capacity of the indoor heat exchanger.

10. The control device for a refrigeration cycle device according to claim 8, wherein the structural information of the plurality of indoor units is the length of the piping connecting the indoor units to an outdoor unit having the compressor, the outdoor heat exchanger, and the internal heat exchanger.

11. The control device for a refrigeration cycle device according to claim 7, wherein the control device distributes the total opening degree of the indoor side to each of the plurality of indoor expansion valves based on a second distribution ratio, the second distribution ratio is a variable value that changes according to the operating conditions, and the control device changes the second distribution ratio according to the cooling capacity of each of the plurality of indoor heat exchangers.

12. The control device for a refrigeration cycle apparatus according to any one of claims 1 to 11, wherein the control processing device adjusts the first distribution ratio based on the superheating of at least two points among point A at the outlet of the low-pressure side flow path of the internal heat exchanger, point B after the confluence of the outlets of the at least one indoor heat exchanger, and point C after the confluence of point A and point B, such that the superheating of each point is equal to and approaches a target superheating value.

13. The control device for a refrigeration cycle apparatus according to claim 12, wherein the control processing device adjusts the first distribution ratio such that the ratio corresponding to the point with the greater degree of superheating among the at least two points increases.

14. The control processing device is configured such that the at least two points are point A and point B, and the superheat level SH of point A. Ａ And the degree of superheating at point B SH Ｂ SH Ａ > SH Ｂ If the relationship is satisfied, the first distribution ratio is adjusted so that the bypass expansion valve opening increases, SH Ａ <SH Ｂ The control device for a refrigeration cycle device according to claim 13, wherein the first distribution ratio is adjusted to increase the total opening degree on the indoor side when the following relationship is satisfied.

15. When the at least two points are the point A and the point C, and the overheat degree SH of the point A Ａ and the overheat degree SH of the point C Ｃ satisfy the relationship of SH Ａ > SH Ｃ , the first distribution ratio is adjusted so that the bypass expansion valve opening degree increases. When the relationship of SH Ａ < SH Ｃ is satisfied, the control device of the refrigeration cycle apparatus according to claim 13, which adjusts the first distribution ratio so that the total indoor side opening degree increases.

16. The control processing device is configured such that the at least two points are point B and point C, and the superheat level SH of point B. Ｂ The superheating degree SH at point C. Ｃ SH Ｂ > SH Ｃ If the relationship is satisfied, the first distribution ratio is adjusted so that the total opening angle on the indoor side increases, SH Ｂ <SH Ｃ The control device for a refrigeration cycle device according to claim 13, wherein the first distribution ratio is adjusted to increase the bypass expansion valve opening when the following relationship is satisfied.

17. A control device for a refrigeration cycle device according to any one of claims 1 to 11, wherein the control processing device adjusts the first distribution ratio to increase the opening of the bypass expansion valve when the degree of subcooling at the outlet of the outdoor heat exchanger or the degree of subcooling at the outlet of the high-pressure side flow path of the internal heat exchanger is greater than a threshold set corresponding to each of the above.

18. A refrigeration cycle apparatus comprising a control device for a refrigeration cycle apparatus according to any one of claims 1 to 17, and the refrigerant circuit.

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