Patent Application
20240175613
The present invention relates to a refrigeration cycle device.
As described in PTL 1 (Japanese Unexamined Patent Application Publication No. 2008-128628), there is a technique for preventing, in a heat exchanger having a plurality of refrigerant flow paths, a refrigerant flowing through the heat exchanger from flowing unevenly, by adjusting a flow rate of the refrigerant based on a temperature of the refrigerant flowing through the refrigerant flow paths.
A refrigeration cycle device according to a first aspect includes a heat exchanger, a plurality of flow rate adjustment units, and a control unit. The heat exchanger has a plurality of refrigerant flow paths including a first refrigerant flow path and a second refrigerant flow path.
The plurality of flow rate adjustment units adjust flow rates of a refrigerant flowing through the respective refrigerant flow paths. The control unit adjusts the flow rates of the refrigerant flowing through the refrigerant flow paths by controlling opening degrees of the flow rate adjustment units. The control unit controls the opening degrees of the respective flow rate adjustment units based on a first value or a second value. The first value is a value representing overall efficiency of a refrigeration cycle. The second value is a value representing overall efficiency of the heat exchanger.
A refrigeration cycle device 1 constitutes a vapor compression type refrigeration cycle and conditions (cools or heats) air in a target space. In the present embodiment, the refrigeration cycle device 1 is a so-called multi-type air conditioning system for a building.
The air conditioning device 2 includes an indoor unit 20 and an outdoor unit 30. The indoor unit 20 and the outdoor unit 30 are connected to each other via a liquid refrigerant connection pipe 51 and a gas refrigerant connection pipe 52 to constitute a refrigerant circuit 50. Furthermore, the indoor unit 20 and the outdoor unit 30 are communicably connected to each other by a communication line 81. Furthermore, the outdoor unit 30 and the learning device 10 are communicably connected to each other by a communication line 82.
Hereinafter, for example, when refrigerant flow paths 333a to 333i are not to be distinguished from each other, they may be referred to as refrigerant flow paths 333 or the like.
The indoor unit 20 is installed in the target space where air is to be conditioned, such as inside a building in which the refrigeration cycle device 1 is installed. The indoor unit 20 is, for example, a ceiling-embedded type unit, a ceiling-suspended type unit, a floor-mounted type unit, or the like. As illustrated in
Although there is no intention to limit its structure, the indoor heat exchanger 21 is, for example, a cross-fin type, fin-and-tube heat exchanger that includes a heat transfer tube (not illustrated) and a large number of fins (not illustrated). The indoor heat exchanger 21 causes heat to be exchanged between a refrigerant flowing through the indoor heat exchanger 21 and air in the target space.
The indoor heat exchanger 21 functions as an evaporator during cooling operation, and functions as a condenser during heating operation. v (2-1-2) Indoor Fan
The indoor fan 22 causes air in the target space to be taken into the indoor unit 20 and to be supplied to the indoor heat exchanger 21, and then causes the air that has exchanged heat with the refrigerant in the indoor heat exchanger 21 to be supplied to the target space. The indoor fan 22 is, for example, a centrifugal fan such as a turbo fan or a sirocco fan. The indoor fan 22 is driven by an indoor fan motor 22m. A rotation speed of the indoor fan motor 22m can be controlled by an inverter.
The indoor expansion valve 23 is a mechanism for adjusting pressure and a flow rate of the refrigerant flowing through the liquid refrigerant pipe 53a. The indoor expansion valve 23 is provided to the liquid refrigerant pipe 53a. In the present embodiment, the indoor expansion valve 23 is an electronic expansion valve in which its opening degree is adjustable.
The indoor temperature sensor 61 measures a temperature (a room temperature) of air in the target space. The indoor temperature sensor 61 is provided near an air suction port of the indoor unit 20.
The gas-side temperature sensor 62 measures a temperature of the refrigerant flowing through the gas refrigerant pipe 53b. The gas-side temperature sensor 62 is provided to the gas refrigerant pipe 53b.
The liquid-side temperature sensor 63 measures the temperature of the refrigerant flowing through the liquid refrigerant pipe 53a. The liquid-side temperature sensor 63 is provided to the liquid refrigerant pipe 53a.
The indoor temperature sensor 61, the gas-side temperature sensor 62, and the liquid-side temperature sensor 63 are, for example, thermistors.
The indoor control unit 29 controls operation of each part constituting the indoor unit 20.
The indoor control unit 29 is electrically connected to various devices included in the indoor unit 20, the various devices including the indoor expansion valve 23 and the indoor fan motor 22m. Furthermore, the indoor control unit 29 is communicably connected to various sensors provided in the indoor unit 20, the various sensors including the indoor temperature sensor 61, the gas-side temperature sensor 62, and the liquid-side temperature sensor 63.
The indoor control unit 29 includes a control arithmetic device, a storage device, and a network interface device. The control arithmetic device is a processor such as a central processing unit (CPU) or a graphics processing unit (GPU). The storage device is a storage medium such as a random access memory (RAM), a read-only memory (ROM), or a flash memory. The control arithmetic device reads a program stored in the storage device, and performs predetermined arithmetic processing in accordance with the program, thereby controlling operation of each part constituting the indoor unit 20. Furthermore, the control arithmetic device can write calculation results into the storage device, and can read information stored in the storage device, in accordance with the program. The network interface device is configured to communicate with the outdoor unit 30 via the communication line 81. Furthermore, the indoor control unit 29 includes a timer.
The indoor control unit 29 is configured to be able to receive various signals transmitted from an operation remote controller (not illustrated). The various signals include, for example, signals for instructing start and stop of operation, and signals related to various settings. The signals related to various settings include, for example, signals related to a set temperature and set humidity. Furthermore, the indoor control unit 29 exchanges control signals, measurement signals, signals related to various settings, and the like with an outdoor control unit 39 in the outdoor unit 30 via the communication line 81.
The indoor control unit 29 and the outdoor control unit 39 cooperate with each other to function as a control unit 70. Functions of the control unit 70 will be described later.
The outdoor unit 30 is installed outside the target space, such as on a roof floor of the building in which the refrigeration cycle device 1 is installed. As illustrated in
As illustrated in
As illustrated in
The compressor 31 is, for example, a displacement compressor of a rotary type, a scroll type, or the like. The compression mechanism in the compressor 31 is driven by a compressor motor 31m. A rotation speed of the compressor motor 31m can be controlled by an inverter.
The flow path switching valve 32 is a mechanism that switches a flow path of the refrigerant between a first state and a second state. In the first state, the flow path switching valve 32 causes the suction pipe 54a and the second gas refrigerant pipe 54e to communicate with each other, and the discharge pipe 54b and the first gas refrigerant pipe 54c to communicate with each other, as illustrated by solid lines inside the flow path switching valve 32 illustrated in
The flow path switching valve 32 sets the flow path of the refrigerant to the first state during the cooling operation. At this time, the refrigerant discharged from the compressor 31 flows through the outdoor heat exchanger 33, the outdoor expansion valve 34, the indoor expansion valve 23, and the indoor heat exchanger 21 in this order in the refrigerant circuit 50, and returns to the compressor 31. In the first state, the outdoor heat exchanger 33 functions as a condenser, and the indoor heat exchanger 21 functions as an evaporator.
The flow path switching valve 32 sets the flow path of the refrigerant to the second state during the heating operation. At this time, the refrigerant discharged from the compressor 31 flows through the indoor heat exchanger 21, the indoor expansion valve 23, the outdoor expansion valve 34, and the outdoor heat exchanger 33 in this order in the refrigerant circuit 50, and returns to the compressor 31. In the second state, the outdoor heat exchanger 33 functions as an evaporator, and the indoor heat exchanger 21 functions as a condenser.
The heat exchanger main body 331 has the plurality of refrigerant flow paths 333a to 333i including a first refrigerant flow path 333 and a second refrigerant flow path 333. As illustrated in
The flow rate adjustment units 332 adjust the flow rates of the refrigerant flowing through the refrigerant flow paths 333. Specifically, as illustrated in
As illustrated in
As illustrated in
The outdoor expansion valve 34 is a mechanism for adjusting the pressure and the flow rate of the refrigerant flowing through the liquid refrigerant pipe 54d. In the present embodiment, the outdoor expansion valve 34 is an electronic expansion valve in which its opening degree is adjustable.
The accumulator 35 is a container having a gas-liquid separation function for separating the inflowing refrigerant into a gas refrigerant and a liquid refrigerant. The refrigerant flowing into the accumulator 35 is separated into a gas refrigerant and a liquid refrigerant, and the gas refrigerant collected in an upper space flows into the compressor 31.
The outdoor fan 36 is a fan that causes outdoor air to be taken into the outdoor unit 30 and to be supplied to the outdoor heat exchanger 33, and causes the air that has exchanged heat with the refrigerant in the outdoor heat exchanger 33 to be discharged outside the outdoor unit 30. The outdoor fan 36 is, for example, an axial-flow fan such as a propeller fan. The outdoor fan 36 is driven by an outdoor fan motor 36m. A rotation speed of the outdoor fan motor 36m can be controlled by an inverter.
The suction pressure sensor 64 is a sensor that measures suction pressure. The suction pressure sensor 64 is provided to the suction pipe 54a. The suction pressure is a low pressure value of the refrigeration cycle.
The discharge pressure sensor 65 is a sensor that measures discharge pressure. The discharge pressure sensor 65 is provided to the discharge pipe 54b. The discharge pressure is a high pressure value of the refrigeration cycle.
The outdoor temperature sensor 66 measures a temperature of air outside the target space (an outdoor temperature). The outdoor temperature sensor 66 is provided near an air suction port of the outdoor unit 30.
The gas-side temperature sensor 67 measures the temperature of the refrigerant flowing through the first gas refrigerant pipe 54c. The gas-side temperature sensor 67 is provided to the first gas refrigerant pipe 54c.
The liquid-side temperature sensor 68 measures the temperature of the refrigerant flowing through the liquid refrigerant pipe 54d. The liquid-side temperature sensor 63 is provided to the liquid refrigerant pipe 54d.
The outdoor temperature sensor 66, the gas-side temperature sensor 67, and the liquid-side temperature sensor 68 are, for example, thermistors.
As illustrated in
The outdoor control unit 39 controls operation of each part constituting the outdoor unit 30.
The outdoor control unit 39 is electrically connected to various devices included in the outdoor unit 30, the various devices including the compressor motor 31m, the flow path switching valve 32, the flow rate adjustment units 332, the outdoor expansion valve 34, and the outdoor fan motor 36m. Furthermore, the outdoor control unit 39 is communicably connected to various sensors provided in the outdoor unit 30, the various sensors including the suction pressure sensor 64, the discharge pressure sensor 65, the outdoor temperature sensor 66, the gas-side temperature sensor 67, and the liquid-side temperature sensor 68.
The outdoor control unit 39 includes a control arithmetic device, a storage device, and two network interface devices. The control arithmetic device is a processor such as a CPU or a GPU. The storage device is a storage medium such as a RAM, a ROM, or a flash memory. The control arithmetic device reads a program stored in the storage device, and performs predetermined arithmetic processing in accordance with the program, thereby controlling operation of each part constituting the outdoor unit 30. Furthermore, the control arithmetic device can write calculation results into the storage device, and can read information stored in the storage device, in accordance with the program. One of the network interface devices is configured to communicate with the indoor unit 20 via the communication line 81. Another one of the network interface devices is configured to communicate with the learning device 10 via the communication line 82. Furthermore, the outdoor control unit 39 includes a timer.
The outdoor control unit 39 exchanges control signals, measurement signals, signals related to various settings, and the like with the indoor control unit 29 in the indoor unit 20 via the communication line 81. Furthermore, the outdoor control unit 39 exchanges control signals, measurement signals, signals related to various settings, and the like with the learning control unit 19 in the learning device 10 via the communication line 82.
The outdoor control unit 39 and the indoor control unit 29 cooperate with each other to function as the control unit 70. The functions of the control unit 70 will be described later.
The control unit 70 includes the indoor control unit 29 and the outdoor control unit 39.
The control unit 70 mainly performs the cooling operation and the heating operation.
When receiving from the operation remote controller an instruction of causing the indoor unit 20 to perform the cooling operation, the control unit 70 controls the flow path switching valve 32 such that a state as indicated by the solid lines illustrated in
The control unit 70 opens the outdoor expansion valve 34 in a step-wise manner and adjusts the opening degree of the indoor expansion valve 23 such that a degree of superheating of the refrigerant at a gas-side outlet of the indoor heat exchanger 21 reaches a predetermined target degree of superheating. The degree of superheating of the refrigerant at the gas-side outlet of the indoor heat exchanger 21 is calculated, for example, by subtracting an evaporation temperature converted from a measurement value (suction pressure) of the suction pressure sensor 64 from a measurement value of the gas-side temperature sensor 62.
Furthermore, the control unit 70 controls an operating capacity of the compressor 31 such that the evaporation temperature converted from the measurement value of the suction pressure sensor 64 approaches a predetermined target evaporation temperature. The operating capacity of the compressor 31 is controlled by controlling the rotation speed of the compressor motor 31m.
Furthermore, the control unit 70 adjusts, in cooperation with the learning device 10, the flow rates of the refrigerant flowing through the refrigerant flow paths 333a to 333i by controlling the opening degrees of the flow rate adjustment units 332a to 332i (hereinafter sometimes referred to as flow rate adjustment processing). The control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i based on the first value. The first value is a value representing the overall efficiency of the refrigeration cycle. In the present embodiment, the first value includes a pressure value of the refrigerant flowing through the outdoor heat exchanger 33 (hereinafter sometimes referred to as an outdoor pressure value), a temperature of air that exchanges heat with the refrigerant in the outdoor heat exchanger 33 (hereinafter sometimes referred to as an outdoor temperature), and the rotation speed of the outdoor fan motor 36m (hereinafter sometimes referred to as an outdoor fan rotation speed). The outdoor pressure value during the cooling operation is a pressure value on a high pressure side. The outdoor pressure value during the cooling operation is acquired from, for example, the discharge pressure sensor 65. The outdoor temperature is acquired from, for example, the outdoor temperature sensor 66.
The control unit 70 receives, from the learning device 10, information (hereinafter sometimes referred to as opening degree information) regarding a setting range of the opening degrees of the flow rate adjustment units 332a to 332i, per predetermined time T2 (for example, 24 hours). The control unit 70 sets the opening degrees of the flow rate adjustment units 332a to 332i per predetermined time T1 (for example, 10 minutes) within the setting range according to the received opening degree information. In other words, the control unit 70 changes, per the predetermined time T1, the opening degrees of the flow rate adjustment units 332a to 332i within the setting range according to the opening degree information. The control unit 70 waits, each time the opening degrees of the flow rate adjustment units 332a to 332i are set, until the pressure and the temperature of the refrigerant and operation of the various devices become stationary (until the air conditioning device 2 reaches a stationary state), and, after the air conditioning device 2 has reached the stationary state, transmits the opening degrees of the flow rate adjustment units 332a to 332i and an outdoor pressure value at that time (hereinafter sometimes referred to as learning data 131) to the learning device 10. In the present embodiment, the control unit 70 determines that the air conditioning device 2 has reached the stationary state when the outdoor temperature and the outdoor fan rotation speed become stationary. In other words, the outdoor temperature and the outdoor fan rotation speed in the first value are used to determine whether or not the air conditioning device 2 has reached the stationary state.
As described above, the control unit 70 controls various devices such that the room temperature in the target space approaches a set temperature, thereby the refrigerant flowing through the refrigerant circuit 50 during the cooling operation, as described below.
When the compressor 31 is activated, a low-pressure gas refrigerant in the refrigeration cycle is taken into the compressor 31 and is compressed by the compressor 31 to become a high-pressure gas refrigerant in the refrigeration cycle.
The high-pressure gas refrigerant flows through the first gas refrigerant pipe 54c via the flow path switching valve 32, and is supplied to the outdoor heat exchanger 33. After flowing into the header 335, the high-pressure gas refrigerant supplied to the outdoor heat exchanger 33 is caused to be separated flows to separately flow into the refrigerant flow paths 333a to 333i. The refrigerant separately flowing through the refrigerant flow paths 333a to 333i exchanges heat with outdoor air supplied by the outdoor fan 36, condenses, and becomes a high-pressure liquid refrigerant in the heat exchanger main body 331. The refrigerant that has passed through the heat exchanger main body 331 and that flows through the refrigerant flow paths 333a to 333i is adjusted in flow rate by the flow rate adjustment units 332a to 332i so as not to flow unevenly. The separate flows of the refrigerant that has passed through the flow rate adjustment units 332a to 332i and that flows through the refrigerant flow paths 333a to 333i join each other in the flow divider 334, and the joined refrigerant flows out of the outdoor heat exchanger 33. The high-pressure liquid refrigerant that has passed through the outdoor heat exchanger 33 flows through the liquid refrigerant pipe 54d, passes through the outdoor expansion valve 34, and is supplied to the indoor unit 20.
The high-pressure liquid refrigerant supplied to the indoor unit 20 is decompressed to near suction pressure of the compressor 31 in the indoor expansion valve 23, becomes the refrigerant in a gas-liquid two-phase state, and is supplied to the indoor heat exchanger 21. In the indoor heat exchanger 21, the refrigerant in the gas-liquid two-phase state exchanges heat with the air in the target space, which is supplied to the indoor heat exchanger 21 by the indoor fan 22, evaporates, and becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant is supplied to the outdoor unit 30 via the gas refrigerant connection pipe 52 and flows into the accumulator 35 via the flow path switching valve 32. The low-pressure gas refrigerant, which has flowed into the accumulator 35, is taken again into the compressor 31. The temperature of the air supplied to the indoor heat exchanger 21 lowers due to exchange of heat with the refrigerant flowing through the indoor heat exchanger 21, and the air cooled by the indoor heat exchanger 21 is blown into the target space.
When receiving from the operation remote controller an instruction of causing the indoor unit 20 to perform the heating operation, the control unit 70 controls the flow path switching valve 32 such that a state as indicated by the broken lines illustrated in
The control unit 70 adjusts the opening degree of the indoor expansion valve 23 such that a degree of subcooling of the refrigerant at a liquid-side outlet of the indoor heat exchanger 21 reaches a predetermined target degree of subcooling. The degree of subcooling of the refrigerant at the liquid-side outlet of the indoor heat exchanger 21 is calculated, for example, by subtracting a measurement value of the liquid-side temperature sensor 63 from a condensation temperature converted from a measurement value (discharge pressure) of the discharge pressure sensor 65.
Furthermore, the control unit 70 adjusts an opening degree of the outdoor expansion valve 34 such that the refrigerant flowing into the outdoor heat exchanger 33 is decompressed to pressure at which the refrigerant can evaporate in the outdoor heat exchanger 33.
Furthermore, the control unit 70 controls the operating capacity of the compressor 31 such that the condensation temperature converted from the measurement value of the discharge pressure sensor 65 approaches a predetermined target condensation temperature. The operating capacity of the compressor 31 is controlled by controlling the rotation speed of the compressor motor 31m.
Furthermore, similarly to the cooling operation, the control unit 70 adjusts, in cooperation with the learning device 10, the flow rates of the refrigerant flowing through the refrigerant flow paths 333a to 333i by controlling the opening degrees of the flow rate adjustment units 332a to 332i. However, the outdoor pressure value during the heating operation is a pressure value on a low pressure side. The outdoor pressure value during the heating operation is acquired from, for example, the suction pressure sensor 64.
As described above, since the control unit 70 controls various devices such that the room temperature in the target space approaches a set temperature, the refrigerant flows through the refrigerant circuit 50 during the heating operation, as described below.
When the compressor 31 is activated, a low-pressure gas refrigerant in the refrigeration cycle is taken into the compressor 31 and is compressed by the compressor 31 to become a high-pressure gas refrigerant in the refrigeration cycle. The high-pressure gas refrigerant is supplied to the indoor heat exchanger 21 via the flow path switching valve 32, exchanges heat with the air in the target space, which is supplied by the indoor fan 22, condenses, and becomes a high-pressure liquid refrigerant. The temperature of the air supplied to the indoor heat exchanger 21 rises due to exchange of heat with the refrigerant flowing through the indoor heat exchanger 21, and the air heated by the indoor heat exchanger 21 is blown into the target space.
The high-pressure liquid refrigerant that has passed through the indoor heat exchanger 21, passes through the indoor expansion valve 23, and is decompressed. The refrigerant decompressed in the indoor expansion valve 23 is supplied to the outdoor unit 30 via the liquid refrigerant connection pipe 51 and flows into the liquid refrigerant pipe 54d. The refrigerant flowing through the liquid refrigerant pipe 54d is decompressed to near suction pressure of the compressor 31, when passing through the outdoor expansion valve 34, becomes the refrigerant in a gas-liquid two-phase state, and flows into the outdoor heat exchanger 33. After flowing into the flow divider 334, the low-pressure refrigerant in the gas-liquid two-phase state, which has flowed into the outdoor heat exchanger 33, is caused to be separate flows to separately flow into the refrigerant flow paths 333a to 333i. The refrigerant, which has been caused to be separate flows to separately flow through the refrigerant flow paths 333a to 333i, is adjusted in flow rate by the flow rate adjustment units 332a to 332i so as not to flow unevenly. The refrigerant that has passed through the flow rate adjustment units 332a to 332i and that flows through the refrigerant flow paths 333a to 333i exchanges heat with outdoor air supplied by the outdoor fan 36 in the heat exchanger main body 331, evaporates, and becomes a low-pressure gas refrigerant. The separate flows of the refrigerant that has passed through the heat exchanger main body 331 and that flows through the refrigerant flow paths 333a to 333i join each other in the header 335, and the joined refrigerant flows out of the outdoor heat exchanger 33. The low-pressure gas refrigerant that has passed through the outdoor heat exchanger 33 flows into the accumulator 35 via the flow path switching valve 32. The low-pressure gas refrigerant that has flowed into the accumulator 35 is taken again into the compressor 31.
The learning device 10 learns the appropriate opening degrees of the flow rate adjustment units 332a to 332i in cooperation with the control unit 70 such that the refrigerant flowing through the refrigerant flow paths 333a to 333i does not flow unevenly. In the present embodiment, the learning device 10 is a computer installed in a server room or the like in a building. However, the learning device 10 may be installed in a cloud-based data center or the like. In this case, the communication line 82 includes a line connected to the Internet, for example.
The learning input unit 11 includes a keyboard and a mouse. Various commands and various pieces of information for the learning device 10 can be input using the learning input unit 11.
The learning display unit 12 is a monitor. The learning display unit 12 can display, for example, the learning data 131, a learning situation, and the like.
The learning storage unit 13 is a storage device such as a RAM, a ROM, or a hard disk drive (HDD). The learning storage unit 13 stores a program that the learning control unit 19 executes, data necessary for executing the program, and the like.
The learning storage unit 13 stores, in particular, the learning data 131 and a learning model 132 described later. Table 1 illustrated below indicates an example of the learning data 131 used during the cooling operation.
One record in the learning data 131 corresponds to a fact that the control unit 70 has set once the opening degrees of the flow rate adjustment units 332a to 332i. In Table 1, the items “Opening degree a” to “Opening degree i” respectively indicate the opening degrees of the flow rate adjustment units 332a to 332i, which the control unit 70 has set.
The learning communication unit 14 is a network interface device for performing communications via the communication line 82.
The learning control unit 19 is a processor such as a CPU or a GPU. The learning control unit 19 reads and executes a program stored in the learning storage unit 13 to realize various functions of the learning device 10. Furthermore, the learning control unit 19 can write a calculation result into the learning storage unit 13, and can read information stored in the learning storage unit 13, in accordance with a program. Furthermore, the learning control unit 19 includes a timer.
The learning control unit 19 associates with each other and learns a combination of the opening degrees of the plurality of flow rate adjustment units 332a to 332i and an outdoor pressure value when the opening degrees of the plurality of flow rate adjustment units 332a to 332i correspond to the combination of the opening degrees. In other words, the learning control unit 19 creates the learning model 132 using the learning data 131 as illustrated in Table 1. The learning model 132 according to the present embodiment is a classification-type model. As the learning model 132 according to the present embodiment, for example, a neural network, logistic regression, a support vector machine, or the like can be used.
Specifically, the learning control unit 19 first estimates, as preprocessing, a level of the heat exchange capability of the outdoor heat exchanger 33 from an outdoor pressure value. In a case of the cooling operation, it is estimated that the smaller the outdoor pressure value (a pressure value on the high-pressure side), the higher the heat exchange capability of the outdoor heat exchanger 33. Therefore, the learning control unit 19 designates, for example, a predetermined percentage (for example, 20%), from among the records in the learning data 131, in ascending order of the outdoor pressure value and estimates that the heat exchange capability of the outdoor heat exchanger 33 is high in these records and that the heat exchange capability of the outdoor heat exchanger 33 is low in the other records. In a case of the heating operation, it is estimated that the larger the outdoor pressure value (the pressure value on the low pressure side), the higher the heat exchange capability of the outdoor heat exchanger 33. Therefore, the learning control unit 19 designates, for example, a predetermined percentage (for example, 20%), from among the records in the learning data 131, in descending order of the outdoor pressure values and estimates that the heat exchange capability of the outdoor heat exchanger 33 is high in these records and that the heat exchange capability of the outdoor heat exchanger 33 is low in the other records. Table 2 illustrated below indicates an example when the preprocessing is performed on the learning data 131 in Table 1.
Since Table 1 indicates the learning data 131 during the cooling operation, the smaller the outdoor pressure value, the higher the possibility that the heat exchange capability is “high”, in Table 2.
Next, the learning control unit 19 classifies the combination of the opening degrees of the flow rate adjustment units 332a to 332i in accordance with the level of the heat exchange capability of the outdoor heat exchanger 33, which is estimated from the outdoor pressure value. In other words, the learning control unit 19 creates the learning model 132 using the combination of the opening degrees of the flow rate adjustment units 332a to 332i as an explanatory variable and the heat exchange capability as an objective variable, and classifies the combination of the opening degrees of the flow rate adjustment units 332a to 332i. Further, in other words, the learning control unit 19 creates the learning model 132 that divides an opening degree space (here, a nine-dimensional space where values of Opening degree a to Opening degree i serve as axes), in which each point represents a combination of the opening degrees of the flow rate adjustment units 332a to 332i, into a region in which the heat exchange capability is estimated to be “high” and a region in which the heat exchange capability is estimated to be “low”.
In an upper left diagram in
An upper center diagram in
In response to a region in which the heat exchange capability is estimated to be “high” (the region R1) being determined, the learning control unit 19 transmits information about the region to the control unit 70 as opening degree information. In other words, the opening degree information is information about a combination of the opening degrees of the flow rate adjustment units 332a to 332i, which is classified by the learning device 10 into a class at which the heat exchange capability of the outdoor heat exchanger 33 is higher than a predetermined value.
Thereafter, the control unit 70 uses the opening degree information received from the learning device 10 to control, within a range of the region in which the heat exchange capability is estimated to be “high” (the region R1), the opening degrees of the respective flow rate adjustment units 332a to 332i. Each time the opening degrees of the flow rate adjustment units 332a to 332i have been set, the control unit 70 transmits the learning data 131 to the learning device 10. In an upper right diagram in
The learning control unit 19 creates the learning model 132 again based on the learning data 131 that has newly been created. A lower left diagram in
An example of the flow rate adjustment processing will be described with reference to a flowchart illustrated in
As illustrated in step S1, the control unit 70 starts the cooling operation or the heating operation in response to an instruction or the like from the operation remote controller.
As step S1 ends, as illustrated in step S2, the control unit 70 determines whether or not new opening degree information has been received from the learning device 10. As new opening degree information is received, the processing proceeds to step S3. If new opening degree information has not yet been received, the processing proceeds to step S4.
As the processing proceeds from step S2 to step S3, the control unit 70 updates the old opening degree information with the new opening degree information received from the learning device 10.
As the processing proceeds from step S2 to step S4, or as step S3 ends, the control unit 70 sets the opening degrees of the flow rate adjustment units 332a to 332i within a range of the opening degree information.
As step S4 ends, as illustrated in step S5, the control unit 70 waits until the air conditioning device 2 reaches the stationary state.
As step S5 ends, as illustrated in step S6, the control unit 70 transmits the learning data 131 to the learning device 10.
As step S6 ends, as illustrated in step S7, the control unit 70 waits for the predetermined time T1. The predetermined time T1 is, for example, 10 minutes. As the predetermined time T1 has elapsed, the processing proceeds to step S2, and the control unit 70 again determines whether or not new opening degree information has been received from the learning device 10.
Meanwhile, as illustrated in step S8, the learning control unit 19 determines whether or not the learning data 131 has been received from the air conditioning device 2. As the learning data 131 has been received, the processing proceeds to step S9. If the learning data 131 has not yet been received, the processing proceeds to step S10.
As the processing proceeds from step S8 to step S9, the learning control unit 19 accumulates the received learning data 131 in the learning storage unit 13.
As the processing proceeds from step S8 to step S10, or as step S9 ends, the learning control unit 19 determines whether or not the predetermined time T2 has elapsed. The predetermined time T2 is, for example, 24 hours. As the predetermined time T2 has elapsed, the processing proceeds to step S11. If the predetermined time T2 has not yet elapsed, the processing proceeds to step S8, and the learning control unit 19 determines again whether or not the learning data 131 has been received from the air conditioning device 2.
As the processing proceeds from step S10 to step S11, the learning control unit 19 creates the learning model 132 based on the learning data 131 that has been accumulated.
As step S11 ends, as illustrated in step S12, the learning control unit 19 transmits the opening degree information based on the created learning model 132 to the air conditioning device 2.
As step S12 ends, as illustrated in step S13, the learning control unit 19 deletes the learning data 131 that is old data, which has been used to create the learning model 132.
As step S13 ends, as illustrated in step S8 and step S9, the learning control unit 19 accumulates again the learning data 131 that is new data.
The control unit 70 and the learning control unit 19 continue this processing until the cooling operation or the heating operation is stopped by an instruction or the like from the operation remote controller.
In the related art, there is a technique for preventing, in a heat exchanger having a plurality of refrigerant flow paths, a refrigerant flowing through the heat exchanger from flowing unevenly, by adjusting a flow rate of the refrigerant based on a temperature of the refrigerant flowing through the refrigerant flow paths.
In such a technique of the related art, when a flow rate of a refrigerant is to be adjusted based on a temperature of the refrigerant flowing through the refrigerant flow paths, there is an issue in that a temperature sensor is required for each of the refrigerant flow paths.
The refrigeration cycle device 1 according to the present embodiment includes the heat exchanger main body 331, the plurality of flow rate adjustment units 332a to 332i, and the control unit 70. The heat exchanger main body 331 has the plurality of refrigerant flow paths 333a to 333i including the first refrigerant flow path 333 and the second refrigerant flow path 333. The plurality of flow rate adjustment units 332a to 332i adjust the flow rates of the refrigerant flowing through the refrigerant flow paths 333a to 333i, respectively. The control unit 70 adjusts the flow rates of the refrigerant flowing through the refrigerant flow paths 333 by controlling the opening degrees of the flow rate adjustment units 332. The control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i based on the first value. The first value is a value representing the overall efficiency of the refrigeration cycle.
In the refrigeration cycle device 1 according to the present embodiment, the control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i based on the first value. The first value is a value representing the overall efficiency of the refrigeration cycle. As a result, the refrigeration cycle device 1 can adjust the flow rates of the refrigerant flowing through the respective refrigerant flow paths 333a to 333i by using sensors, the number of which is smaller than the number of the refrigerant flow paths 333, and can prevent the refrigerant flowing through the outdoor heat exchanger 33 from flowing unevenly.
In the refrigeration cycle device 1 according to the present embodiment, the first value includes the pressure value of the refrigerant flowing through the indoor heat exchanger 21 (during the cooling operation) or the outdoor heat exchanger 33 (during the heating operation). As a result, the refrigeration cycle device 1 can estimate an uneven flow state of the refrigerant flowing through the outdoor heat exchanger 33, and can adjust the flow rates of the refrigerant flowing through the respective refrigerant flow paths 333a to 333i.
In the refrigeration cycle device 1 according to the present embodiment, the first value further includes a temperature of air that exchanges heat with the refrigerant in the outdoor heat exchanger 33. As a result, the refrigeration cycle device 1 can more accurately estimate an uneven flow state of the refrigerant flowing through the outdoor heat exchanger 33 and can adjust the flow rates of the refrigerant flowing through the respective refrigerant flow paths 333a to 333i.
In the refrigeration cycle device 1 according to the present embodiment, the first value further includes the rotation speed of the outdoor fan motor 36m that generates a flow of air that exchanges heat with the refrigerant in the outdoor heat exchanger 33. As a result, the refrigeration cycle device 1 can more accurately estimate an uneven flow state of the refrigerant flowing through the outdoor heat exchanger 33 and can adjust the flow rates of the refrigerant flowing through the respective refrigerant flow paths 333a to 333i.
The refrigeration cycle device 1 according to the present embodiment further includes the learning device 10. The learning device 10 associates with each other and learns a combination of the opening degrees of the plurality of flow rate adjustment units 332a to 332i and the first value when the opening degrees of the plurality of flow rate adjustment units 332a to 332i correspond to the combination of the opening degrees. The learning device 10 classifies the combination of the opening degrees in accordance with a level of the heat exchange capability of the outdoor heat exchanger 33, which is estimated from the first value. The control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i by using the combination of the opening degrees, which is classified, by the learning device 10, into a class at which the heat exchange capability of the outdoor heat exchanger 33 is higher than a predetermined value.
In the refrigeration cycle device 1 according to the present embodiment, using machine learning makes it possible to efficiently calculate a combination of the opening degrees of the flow rate adjustment units 332a to 332i, under which the heat exchange capability of the outdoor heat exchanger 33 improves (under which the refrigerant flowing through the outdoor heat exchanger 33 will be less likely to flow unevenly).
In the present embodiment, an outdoor pressure value is used as the first value for estimating the heat exchange capability of the outdoor heat exchanger 33. However, instead of an outdoor pressure value, an electric power consumption value of the compressor 31 may be used as the first value for estimating the heat exchange capability of the outdoor heat exchanger 33.
In both the cooling operation and the heating operation, it is estimated that the smaller the electric power consumption value of the compressor 31, the higher the heat exchange capability of the outdoor heat exchanger 33. Therefore, the learning control unit 19 designates, for example, a predetermined percentage (for example, 20%), from among the records in the learning data 131, in ascending order of the electric power consumption values of the compressor 31 and estimates that the heat exchange capability of the outdoor heat exchanger 33 is high in these records, and the heat exchange capability of the outdoor heat exchanger 33 is low in the other records.
When both the outdoor pressure value and the electric power consumption value of the compressor 31 are used as the first value, for example, one of them may be used to determine whether or not the air conditioning device 2 is in the stationary state.
In the present embodiment, the first value includes an outdoor pressure value, an outdoor temperature, and an outdoor fan rotation speed. However, the first value may further include the rotation speed of the compressor motor 31m and the opening degree of the outdoor expansion valve 34. The rotation speed of the compressor motor 31m and the opening degree of the outdoor expansion valve 34 are used, for example, to determine whether or not the air conditioning device 2 is in the stationary state.
As a result, the refrigeration cycle device 1 can more accurately estimate an uneven flow state of the refrigerant flowing through the outdoor heat exchanger 33, and can adjust the flow rates of the refrigerant flowing through the respective refrigerant flow paths 333a to 333i.
In the present embodiment, the control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i based on the first value. However, the control unit 70 may control the opening degrees of the respective flow rate adjustment units 332a to 332i based on the second value. The second value is a value representing the overall efficiency of the outdoor heat exchanger 33. In the present modified example, the second value includes an outlet temperature of the outdoor heat exchanger 33 (hereinafter sometimes referred to as an outdoor outlet temperature) after the refrigerant flowed out of the first refrigerant flow path 333 and the refrigerant flowed out of the second refrigerant flow path 333 have joined each other, an outdoor temperature, and an outdoor fan rotation speed. As a result, the refrigeration cycle device 1 can estimate an uneven flow state of the refrigerant flowing through the outdoor heat exchanger 33 and can adjust the flow rates of the refrigerant flowing through the respective refrigerant flow paths 333a to 333i.
The outdoor outlet temperature during the cooling operation represents a condensation temperature. The outdoor outlet temperature during the cooling operation is acquired from, for example, the liquid-side temperature sensor 68. The outdoor outlet temperature during the heating operation is an evaporation temperature. The outdoor outlet temperature during the heating operation is acquired from, for example, the gas-side temperature sensor 67. The second value may further include the rotation speed of the compressor motor 31m and the opening degree of the outdoor expansion valve 34. Note that, for example, when the outdoor heat exchanger 33 has a plurality of flow dividers 334 (although there is one in the present embodiment) and the liquid-side temperature sensors 68 are installed at respective outlets, an average of measured values of the liquid-side temperature sensors 68 may be used as an outdoor outlet temperature during the cooling operation.
Similarly to a case of the first value, the control unit 70 receives opening degree information from the learning device 10 per predetermined time T2. The control unit 70 sets the opening degrees of the flow rate adjustment units 332a to 332i per predetermined time T1 within a setting range of the received opening degree information. The control unit 70 waits, each time the opening degrees of the flow rate adjustment units 332a to 332i have been set, until the air conditioning device 2 reaches the stationary state, and, after the air conditioning device 2 has reached the stationary state, transmits, to the learning device 10, the opening degrees of the flow rate adjustment units 332a to 332i and an outdoor outlet temperature at that time (which serve as the learning data 131). In the present modified example, the control unit 70 determines that the air conditioning device 2 has reached the stationary state when the outdoor temperature and the outdoor fan rotation speed become stationary. The control unit 70 may further determine that the air conditioning device 2 has reached the stationary state when the rotation speed of the compressor motor 31m and the opening degree of the outdoor expansion valve 34 become stationary.
The learning control unit 19 estimates a level of the heat exchange capability of the outdoor heat exchanger 33 from the outdoor outlet temperature. In a case of the cooling operation, it is estimated that the lower the outdoor outlet temperature, the higher the heat exchange capability of the outdoor heat exchanger 33. Therefore, the learning control unit 19 designates, for example, a predetermined percentage (for example, 20%), from among the records in the learning data 131, in ascending order of the outdoor outlet temperatures and estimates that the heat exchange capability of the outdoor heat exchanger 33 is high in these records, and that the heat exchange capability of the outdoor heat exchanger 33 is low in the other records. In a case of the heating operation, it is estimated that the higher the outdoor outlet temperature, the higher the heat exchange capability of the outdoor heat exchanger 33. Therefore, the learning control unit 19 designates, for example, a predetermined percentage (for example, 20%), from among the records in the learning data 131, in descending order of the outdoor outlet temperatures and estimates that the heat exchange capability of the outdoor heat exchanger 33 is high in these records and that the heat exchange capability of the outdoor heat exchanger 33 is low in the other records.
In the present embodiment, the learning control unit 19 uses the learning model 132 that is a classification type. However, the learning control unit 19 may use a learning model 133 that is a regression type. As a regression type learning model 133, for example, a neural network, linear regression, or the like can be used.
Hereinafter, an example of the flow rate adjustment processing in a case where the regression type learning model 133 is used will be described with reference to a flowchart illustrated in
As a premise, when the control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i based on the first value, the first value includes an outdoor pressure value, an outdoor temperature, and an outdoor fan rotation speed. When the control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i based on the second value, the second value includes an outdoor outlet temperature, an outdoor temperature, and an outdoor fan rotation speed.
Furthermore, the learning control unit 19 associates with each other and learns in advance a combination of the opening degrees of the plurality of flow rate adjustment units 332a to 332i and the outdoor pressure value or the outdoor outlet temperature when the opening degrees of the plurality of flow rate adjustment units 332a to 332i correspond to the combination of the opening degrees. In other words, the learning control unit 19 creates the learning model 133 in advance using the combination of the opening degrees of the flow rate adjustment units 332a to 332i as an explanatory variable and the outdoor pressure value or the outdoor outlet temperature as an objective variable. Furthermore, the control unit 70 determines in advance initial values of the opening degrees of the flow rate adjustment units 332a to 332i when the cooling operation or the heating operation is to be started.
As illustrated in step S101, the control unit 70 starts the cooling operation or the heating operation in response to an instruction or the like from the operation remote controller.
As step S101 ends, as illustrated in step S102, the control unit 70 sets the opening degrees of the flow rate adjustment units 332a to 332i to the initial values.
As step S102 ends, as illustrated in step S103, the control unit 70 waits until the air conditioning device 2 reaches the stationary state. In the present modified example, the control unit 70 determines that the air conditioning device 2 has reached the stationary state when the outdoor temperature and the outdoor fan rotation speed become stationary.
As step S103 ends, as illustrated in step S104, the control unit 70 transmits the learning data 131 to the learning device 10. In other words, the control unit 70 transmits, to the learning device 10, the combination of the opening degrees of the flow rate adjustment units 332a to 332i and the outdoor pressure value or the outdoor outlet temperature when the air conditioning device 2 has reached the stationary state.
When the learning data 131 is received from the air conditioning device 2, as illustrated in step S105, the learning control unit 19 updates the learning model 133 by using the learning data 131.
As step S105 ends, as illustrated in step S106, the learning control unit 19 calculates, based on the combination of the opening degrees of the flow rate adjustment units 332a to 332i (hereinafter sometimes referred to as a reference opening degree) in the learning data 131 received from the learning device 10 and the learning model 133 that has been updated, such a combination of the opening degrees of the flow rate adjustment units 332a to 332i that improves the heat exchange capability of the outdoor heat exchanger 33, which is estimated from the outdoor pressure value or the outdoor outlet temperature. Specifically, the learning control unit 19 calculates most appropriate points (the most appropriate opening degrees of the flow rate adjustment units 332a to 332i), at which the heat exchange capability of the outdoor heat exchanger 33 is estimated to be highest, from among neighboring points to a point corresponding to the reference opening degree in the opening degree space. Furthermore, specifically, when the learning model 133 estimates an outdoor pressure value, a neighboring point at which a lowest outdoor pressure value is estimated during the cooling operation and a neighboring point at which a highest outdoor pressure value is estimated during the heating operation are set as most appropriate points. Furthermore, when the learning model 133 estimates an outdoor outlet temperature, a neighboring point at which a lowest outdoor outlet temperature is estimated during the cooling operation and a neighboring point at which a highest outdoor outlet temperature is estimated during the heating operation are set as most appropriate points.
As step S106 ends, as illustrated in step S107, the learning control unit 19 transmits the combination of the most appropriate opening degrees of the flow rate adjustment units 332a to 332i to the air conditioning device 2.
As the combination of the opening degrees of the flow rate adjustment units 332a to 332i is received from the learning device 10, as illustrated in step S108, the control unit 70 waits for a predetermined time T3. The predetermined time T3 is, for example, 10 minutes.
As step S108 ends, as illustrated in step S109, the control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i by using the combination of the opening degrees, which is calculated by the learning device 10. In other words, the control unit 70 sets the combination of the opening degrees, which is received from the learning device 10, in the flow rate adjustment units 332a to 332i.
As step S109 ends, as illustrated in step S103, the control unit 70 waits until the air conditioning device 2 reaches the stationary state again.
The control unit 70 and the learning control unit 19 continue this processing until the cooling operation or the heating operation is stopped by an instruction or the like from the operation remote controller.
In the present embodiment, the control unit 70 controls the opening degrees of the respective flow rate adjustment units 332a to 332i such that the refrigerant flowing through the refrigerant flow paths 333a to 333i in the outdoor heat exchanger 33 does not flow unevenly. However, in a case where the indoor heat exchanger 21 includes, similarly to the outdoor heat exchanger 33, a plurality of flow rate adjustment units 212a to 212i, and a plurality of refrigerant flow paths 213a to 213i, the control unit 70 may further control opening degrees of the respective flow rate adjustment units 212a to 212i such that the refrigerant flowing through the refrigerant flow paths 213a to 213i in the indoor heat exchanger 21 does not flow unevenly.
The heat exchanger main body 211 has the plurality of refrigerant flow paths 213a to 213i including a first refrigerant flow path 213 and a second refrigerant flow path 213. As illustrated in
The flow rate adjustment units 212 adjust the flow rates of the refrigerant flowing through the refrigerant flow paths 213. Specifically, as illustrated in
As illustrated in
As illustrated in
The control unit 70 adjusts, in cooperation with the learning device 10, the flow rates of the refrigerant flowing through the refrigerant flow paths 213a to 213i by controlling the opening degrees of the flow rate adjustment units 212a to 212i.
When the control unit 70 controls the opening degrees of the respective flow rate adjustment units 212a to 212i based on the first value, the first value can include a pressure value of the refrigerant flowing through the indoor heat exchanger 21 (hereinafter sometimes referred to as an indoor pressure value), a temperature of air that exchanges heat with the refrigerant in the indoor heat exchanger 21 (hereinafter sometimes referred to as an indoor temperature), and the rotation speed of the indoor fan motor 22m (hereinafter sometimes referred to as an indoor fan rotation speed). The first value may further include the rotation speed of the compressor motor 31m and the opening degree of the indoor expansion valve 23.
The indoor pressure value during the cooling operation is a pressure value on the low pressure side. The indoor pressure value during the cooling operation is acquired from, for example, the suction pressure sensor 64. The indoor temperature is acquired from, for example, the indoor temperature sensor 61. In a case of the cooling operation, it is estimated that the larger the indoor pressure value, the higher the heat exchange capability of the indoor heat exchanger 21.
The indoor pressure value during the heating operation is a pressure value on the high pressure side. The indoor pressure value during the heating operation is acquired from, for example, the discharge pressure sensor 65. In a case of the heating operation, it is estimated that the smaller the indoor pressure value, the higher the heat exchange capability of the indoor heat exchanger 21.
In both the cooling operation and the heating operation, the control unit 70 can determine that the air conditioning device 2 has reached the stationary state when the indoor temperature and the indoor fan rotation speed become stationary. The control unit 70 may further determine that the air conditioning device 2 has reached the stationary state when the rotation speed of the compressor motor 31m and the opening degree of the indoor expansion valve 23 become stationary.
When the control unit 70 controls the opening degrees of the respective flow rate adjustment units 212a to 212i based on the second value, the second value can include an outlet temperature of the indoor heat exchanger 21 (hereinafter sometimes referred to as an indoor outlet temperature) after the refrigerant flowing out of the first refrigerant flow path 213 and the refrigerant flowing out of the second refrigerant flow path 213 have joined each other, an indoor temperature, and an indoor fan rotation speed. The second value may further include the rotation speed of the compressor motor 31m and the opening degree of the indoor expansion valve 23.
The indoor outlet temperature during the cooling operation is an evaporation temperature. The indoor outlet temperature during the cooling operation is acquired from, for example, the gas-side temperature sensor 62. In a case of the cooling operation, it is estimated that the higher the indoor outlet temperature, the higher the heat exchange capability of the indoor heat exchanger 21.
The indoor outlet temperature during the heating operation is a condensation temperature. The indoor outlet temperature during the heating operation is acquired from, for example, the liquid-side temperature sensor 63. In a case of the heating operation, it is estimated that the lower the indoor outlet temperature, the higher the heat exchange capability of the indoor heat exchanger 21.
In both the cooling operation and the heating operation, the control unit 70 can determine that the air conditioning device 2 has reached the stationary state when the indoor temperature and the indoor fan rotation speed become stationary. The control unit 70 may further determine that the air conditioning device 2 has reached the stationary state when the rotation speed of the compressor motor 31m and the opening degree of the indoor expansion valve 23 become stationary.
While the embodiment of the present disclosure has been described above, it will be understood that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as set forth in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-129044 | Aug 2021 | JP | national |
This application is a Continuation of PCT International Application No. PCT/JP2022/029573, filed on Aug. 2, 2022, which claims priority under 35 U.S.C. § 119(a) to Patent Application No. JP 2021-129044, filed in Japan on Aug. 5, 2021, all of which are hereby expressly incorporated by reference into the present application.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/029573 | Aug 2022 | WO |
| Child | 18430758 | US |
