Refrigeration cycle device

Abstract

To provide a refrigeration cycle device capable of suppressing a deterioration in comfort due to difference of responsiveness of a control object.SOLUTION: According to an aspect of the present invention, a refrigeration cycle device includes an outdoor unit, at least one first indoor unit, at least one relay unit, and control means. The outdoor unit has a compressor and an outdoor heat exchanger. The first indoor unit includes a refrigerant heat exchanger for performing heat exchange between refrigerant and air and a first expansion valve and is connected to the outdoor unit. The relay unit includes a water refrigeration heat exchanger for performing heat exchange between refrigerant and air and a second expansion valve and is connected to an outdoor unit in parallel with the first indoor unit. The control means has a terminal identification unit for individually identifying operation states of the first indoor unit and the relay unit, and determines a control pattern of rotational frequency of the compressor in accordance with identification information of a terminal identification unit and the total sum of required capacities from the first indoor unit and the relay unit. The control means determines a control time of the rotational frequency of the compressor according to the identification information of the terminal identification unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a refrigeration cycle apparatus including a relay unit that connects a refrigerant circuit and a water circuit. [Background technology]

[0002] In an air conditioner (multi-air conditioner) in which multiple indoor units are connected in parallel to an outdoor unit, feedback control is performed at regular intervals to adjust the compressor rotation speed and the opening of each indoor unit's expansion valve so that the required capacity (the capacity required for the room temperature to reach the set temperature) transmitted from each indoor unit can be met, in order to individually adjust the capacity of each indoor unit (see, for example, Patent Document 1).

[0003] Also known is an air conditioner that includes a refrigerant circuit having a compressor that circulates the refrigerant and an outdoor heat exchanger, a water circuit having a water-refrigerant heat exchanger and a pump that circulates water that exchanges heat with the refrigerant, a direct expansion type indoor unit (direct expansion terminal) connected to the refrigerant circuit, and an intermediate expansion type indoor unit (intermediate expansion terminal) connected to the water circuit (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-356669 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-89950 Summary of the Invention [Problem to be solved by the invention]

[0005] The update interval of the feedback control, which adjusts the compressor rotation speed and the opening of the expansion valve of each indoor unit in accordance with the required capacity transmitted from multiple indoor units, is set according to the responsiveness of the controlled object, and when there are multiple controlled objects, it is generally set according to the one with the worse responsiveness. Therefore, in an air conditioner in which a direct expansion terminal and a partial expansion terminal operate simultaneously, the update interval of the feedback control is set according to the partial expansion terminal, which has worse responsiveness than the direct expansion terminal.

[0006] However, if the update interval of the feedback control is set to match the expansion terminal, the update interval will be longer than the thermal time constant of the direct expansion terminal, which will lengthen the time it takes for the temperature in the room where the direct expansion terminal is installed to reach the set temperature, resulting in a problem of reduced comfort. Conversely, if the update interval of the feedback control is set to match the direct expansion terminal, the update interval will be shorter than the thermal time constant of the direct expansion terminal, which will result in an overcalculation of the required capacity from the expansion terminal, resulting in an excessive capacity of the expansion terminal and a problem of reduced comfort in the room where the expansion terminal is installed.

[0007] In view of the above circumstances, the object of the present invention is to provide a refrigeration cycle device in an air conditioner equipped with a direct expansion terminal and a partial expansion terminal, which can suppress a decrease in comfort due to differences in the responsiveness of the controlled object. [Means for solving the problem]

[0008] A refrigeration cycle apparatus according to one embodiment of the present invention includes an outdoor unit, at least one first indoor unit, at least one relay unit, and control means. The outdoor unit includes a compressor and an outdoor heat exchanger. The first indoor unit has a refrigerant heat exchanger that exchanges heat between a refrigerant and air, and a first expansion valve, and is connected to the outdoor unit. The relay unit has a water-refrigerant heat exchanger that exchanges heat between refrigerant and water, and a second expansion valve, and is connected to the outdoor unit in parallel with the first indoor unit. The control means has a terminal identification unit that individually identifies the operating states of the first indoor unit and the relay unit, and determines a control pattern for the compressor rotation speed according to the identification information of the terminal identification unit and the sum of the required capacities from the first indoor unit and the relay unit. The control means determines a control time for the rotation speed of the compressor in accordance with the identification information of the terminal identification section.

[0009] In the above refrigeration cycle equipment, the control time (control interval / change rate) of the compressor rotation speed is determined according to the operating conditions, so that the control time is lengthened to prevent excessive control during intermediate expansion terminal operation, and the control time is shortened to quickly reach the set temperature during direct expansion terminal sole operation, thereby preventing a decrease in comfort.

[0010] The control means may be configured to set the control time to be shorter when only the first indoor unit is in operation than when only the relay unit is in operation.

[0011] The refrigeration cycle apparatus may further include at least one second indoor unit. The second indoor unit is connected to the relay unit via a water pipe and has a water-air heat exchanger that exchanges heat between water and air and a flow control valve. The terminal identification unit may identify the operating state of the second indoor unit as the operating state of the relay unit, and the control means may determine a control time for the rotation speed of the compressor depending on the ratio of the number of operating first indoor units to the number of operating second indoor units.

[0012] The control means may be configured to shorten the control time when the number of operating first indoor units is greater than the number of operating second indoor units, compared to when the number of operating first indoor units is less than the number of operating second indoor units.

[0013] The refrigeration cycle apparatus may further include a storage unit that stores, as the control times, a first control time for the first indoor unit and a second control time for the relay unit, which is longer than the first control time. The control means may select either the first control time or the second control time as the control time.

[0014] Alternatively, the refrigeration cycle apparatus may further include at least one second indoor unit and a memory unit. The second indoor unit is connected to the relay unit via a water pipe and has a water-air heat exchanger that exchanges heat between water and air and a flow control valve. The memory unit stores a usage history of the first indoor unit and the second indoor unit. The terminal identification unit may identify the operating state of the second indoor unit as the operating state of the relay unit, and the control means may determine the control time for the indoor unit that is more frequently used between the first indoor unit and the second indoor unit that are in operation.

[0015] Alternatively, the refrigeration cycle apparatus may further include a storage unit that stores installation information of the first indoor unit and the relay unit. The control means may determine the control time according to the identification information and the installation information.

[0016] The control means may determine, as the control time, a control interval for the rotation speed of the compressor in accordance with the identification information of the terminal identification unit.

[0017] Alternatively, the control means may determine, as the control time, a rate of change in the rotation speed of the compressor in accordance with the identification information of the terminal identification unit.

[0018] A refrigeration cycle apparatus according to another aspect of the present invention comprises an outdoor unit, at least one first indoor unit, at least one relay unit, and control means. The outdoor unit includes a compressor and an outdoor heat exchanger. The first indoor unit has a refrigerant heat exchanger that exchanges heat between a refrigerant and air, and a first expansion valve, and is connected to the outdoor unit. The relay unit has a water-refrigerant heat exchanger that exchanges heat between refrigerant and water, and a second expansion valve, and is connected to the outdoor unit in parallel with the first indoor unit. The control means has a terminal identification unit that individually identifies the operating states of the first indoor unit and the relay unit, and determines a control pattern for the compressor rotation speed according to the identification information of the terminal identification unit and the sum of the required capacities from the first indoor unit and the relay unit. The control means acquires the required capacity at predetermined time intervals, and when the relay unit is in operation, masks the input of the required capacity from the relay unit at predetermined intervals to determine the control time for the compressor rotation speed.

[0019] By masking (ignoring) the input of the intermediate expansion terminal at predetermined intervals in this way, it is possible to adjust the capacity at control intervals appropriate for both the direct expansion terminal and the intermediate expansion terminal.

[0020] The refrigeration cycle apparatus may further include at least one second indoor unit connected to the relay unit via a water pipe and including a water-air heat exchanger for exchanging heat between water and air and a flow control valve. The terminal identification unit may further identify the operating state of the second indoor unit as the operating state of the relay unit, and the control means may determine whether or not to mask the input of required capacity from the relay unit depending on the ratio between the number of operating first indoor units and the number of operating second indoor units.

[0021] The refrigeration cycle apparatus may further include a storage unit that stores installation information of the first indoor unit and the relay unit. The control means may change a frequency of masking an input of required capacity from the relay unit according to the identification information and the installation information. [Effects of the Invention]

[0022] According to the present invention, in an air conditioner equipped with a direct expansion terminal and a partial expansion terminal, it is possible to suppress a decrease in comfort due to differences in the responsiveness of the controlled object. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a refrigerant-water circuit diagram of a refrigeration cycle device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control device. [Figure 3] FIG. 10 is a diagram showing the relationship between the change in room temperature on the direct expansion terminal side and the change in room temperature on the intermediate expansion terminal side with respect to the change in the condensation temperature of the refrigerant. [Figure 4] FIG. 2 is a functional block diagram showing an example of the configuration of the control device. [Figure 5] FIG. 4 is a diagram illustrating an example of a table showing the relationship between the capacity required by an indoor unit and the rotation speed of a compressor. [Figure 6] 10 is an explanatory diagram showing an example of the relationship between each pattern of the number of operating first indoor units (direct expansion terminals) and second indoor units (intermediate expansion terminals) and the control interval of the compressor rotation speed. FIG. [Figure 7] FIG. 4 is an explanatory diagram of one operation of the control device. [Figure 8] FIG. 4 is a functional block diagram showing another example of the configuration of the control device. [Figure 9] 10 is an explanatory diagram showing an example of a mask for a required capacity input from an expansion terminal. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] [Configuration of refrigeration cycle equipment] 1 is a refrigerant-water circuit diagram of a refrigeration cycle apparatus 100 according to one embodiment of the present invention. The refrigeration cycle apparatus 100 of this embodiment is an air conditioner, and includes an outdoor unit 2, a plurality (two in this embodiment) of first indoor units 3a, 3b (hereinafter also referred to collectively as first indoor units 3 unless otherwise described individually), a plurality (two in this embodiment) of relay units 50a, 50b (hereinafter also referred to collectively as relay units 50 unless otherwise described individually), and a control device 90.

[0026] (Outdoor unit) The outdoor unit 2 has a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an outdoor expansion valve 24, and an accumulator 25. By connecting these devices to the first indoor unit 3 and the relay unit 50 via piping, a primary refrigerant circuit 20 is formed in which refrigerant (primary refrigerant) circulates in the refrigerant-water circuit of the refrigeration cycle apparatus 100. In addition, the first indoor unit 3 and the relay unit 50 are connected in parallel.

[0027] Compressor 21 is a variable displacement compressor whose operating capacity can be changed by controlling its rotation speed with an inverter (not shown). The refrigerant discharge side of compressor 21 is connected to port a of four-way valve 22 via a discharge pipe 61. The refrigerant suction side of compressor 21 is connected to the refrigerant outflow side of accumulator 25 via a suction pipe 65.

[0028] The four-way valve 22 is a valve for switching the direction of refrigerant flow, and has four ports a, b, c, and d. As described above, port a is connected to the refrigerant discharge side of the compressor 21 by a discharge pipe 61. Port b is connected to one refrigerant inlet / outlet of the outdoor heat exchanger 23 by a refrigerant piping 62. Port c is connected to the refrigerant inlet / outlet of the accumulator 25 by a refrigerant piping 66. Port d is connected to the gas refrigerant inlet / outlet 51b of the water-refrigerant heat exchanger 51 in the relay unit 50 and one refrigerant inlet / outlet of the indoor heat exchanger 31 in the indoor unit 3 by an outdoor unit gas pipe 64, a gas branch pipe 17, and a gas pipe 37.

[0029] The outdoor heat exchanger 23 exchanges heat between the refrigerant and the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 29. One refrigerant inlet and outlet of the outdoor heat exchanger 23 is connected to port b of the four-way valve 22 by refrigerant piping 62 as described above, and the other refrigerant inlet and outlet is connected to the liquid refrigerant inlet and outlet 51a of the water-refrigerant heat exchanger 51 in the relay unit 50 and the first expansion valve 33 in the first indoor unit 3 by an outdoor unit liquid pipe 63, a liquid branch pipe 16, and a liquid pipe 36.

[0030] The outdoor expansion valve 24 is, for example, an electronic expansion valve. The outdoor expansion valve 24 is arranged in the outdoor unit liquid pipe 63, and its opening degree can be adjusted to reduce the pressure of the refrigerant passing through it.

[0031] The outdoor fan 29 is made of resin and is arranged near the outdoor heat exchanger 23. The outdoor fan 29 is rotated by a fan motor (not shown) to take in outside air from an intake port (not shown) of the outdoor unit 2 into the interior of the outdoor unit 2, and discharges the outside air that has exchanged heat with the refrigerant in the outdoor heat exchanger 23 to the outside of the outdoor unit 2 from an outlet port (not shown) of the outdoor unit 2.

[0032] (1st indoor unit) The first indoor unit 3 has an indoor heat exchanger 31, an indoor fan 32, and a first expansion valve (indoor expansion valve) 33. In Fig. 1, the first indoor unit 3 has two first indoor units 3a, 3b connected in parallel. Each of the first indoor units 3a, 3b has the same configuration. The number of first indoor units 3 is not limited to two, as long as there is at least one.

[0033] The indoor heat exchanger 31 is a refrigerant heat exchanger that exchanges heat between the refrigerant and the outside air drawn into the first indoor unit 3 by the rotation of the indoor fan 32. The outdoor unit gas pipe 64 and the first indoor unit 3 are connected by a gas pipe 37, and the gas pipe 37 and one refrigerant inlet and outlet of the indoor heat exchanger 31 are connected by an indoor unit gas pipe 39. The outdoor unit liquid pipe 63 and the first indoor unit 3 are connected by a liquid pipe 36, and the liquid pipe 36 and the other refrigerant inlet and outlet of the indoor heat exchanger 31 are connected by an indoor unit liquid pipe 38.

[0034] The first expansion valve 33 is, for example, an electronic expansion valve. The first expansion valve 33 is arranged in the indoor unit liquid pipe 38, and its opening degree can be adjusted to reduce the pressure of the refrigerant passing through it.

[0035] The indoor fan 32 is made of resin and is located near the indoor heat exchanger 31. The indoor fan 32 is driven by a fan motor (not shown), takes in indoor air from an intake port (not shown) of the first indoor unit 3, and releases the air that has exchanged heat with the refrigerant in the indoor heat exchanger 31 into the room from an outlet port (not shown) of the first indoor unit 3.

[0036] (relay unit) The relay unit 50 has a water-refrigerant heat exchanger 51 and a second expansion valve 52. In Fig. 1, the relay unit 50 has two relay units 50a and 50b connected in parallel. The relay units 50a and 50b are connected to the outdoor unit 2 in parallel with the first indoor unit 3. The relay unit 50 is installed outdoors as a separate unit from the outdoor unit 2, but may also be installed inside the outdoor unit 2. The number of relay units 50 is not limited to multiple, and it is sufficient that there is at least one.

[0037] The water-refrigerant heat exchanger 51 is, for example, a double-pipe heat exchanger, and has a refrigerant side flow path 511, a water side flow path 512, a liquid refrigerant inlet / outlet 51a connected to the liquid pipe 36, a gas refrigerant inlet / outlet 51b connected to the gas pipe 37, a water inlet 51c, and a water outlet 51d.

[0038] One end of the refrigerant-side flow path 511 is connected to the liquid refrigerant inlet / outlet 51a and the other end is connected to the gas refrigerant inlet / outlet 51b. The water-side flow path 512 is connected to the water inlet 51c and the other end is connected to the water outlet 51d. In the water-refrigerant heat exchanger 51, heat is exchanged between the refrigerant flowing through the refrigerant-side flow path 511 and the water flowing through the water-side flow path 512.

[0039] The liquid refrigerant inlet / outlet 51a is connected to the other refrigerant inlet / outlet of the outdoor heat exchanger 23 by a liquid branch pipe 16 and an outdoor unit liquid pipe 63. The liquid branch pipe 16 is a refrigerant pipe branching from the liquid pipe 36. The gas refrigerant inlet / outlet 51b is connected to port d of the four-way valve 22 by a gas branch pipe 17 and an outdoor unit gas pipe 64. The gas branch pipe 17 is a refrigerant pipe branching from the gas pipe 37. The water inlet 51c is connected to the indoor heat exchanger 41 of the second indoor unit 4 by a second water pipe 12. The water outlet 51d is connected to the indoor heat exchanger 41 of the second indoor unit 4 by a first water pipe 11.

[0040] The second expansion valve 52 is, for example, an electronic expansion valve. The second expansion valve 52 is disposed between the outdoor expansion valve 24 and the liquid refrigerant inlet / outlet 51a, and its opening degree can be adjusted to reduce the pressure of the refrigerant passing through it.

[0041] (Secondary refrigerant circuit) The water-refrigerant heat exchanger 51 is connected to secondary refrigerant circuits 40a, 40b in which water, which serves as a secondary refrigerant, circulates. The secondary refrigerant circuit 40a has a second indoor unit 4a connected to the water-refrigerant heat exchanger 51 of the relay unit 50a, and the secondary refrigerant circuit 40b has a second indoor unit 4b connected to the water-refrigerant heat exchanger 51 of the relay unit 50b.

[0042] The secondary refrigerant circuits 40a, 40b have the same configuration, and therefore, except where individually described below, the secondary refrigerant circuits 40a, 40b will be collectively referred to as the secondary refrigerant circuit 40. Similarly, the second indoor units 4a, 4b have the same configuration, and therefore, except where individually described below, the second indoor units 4a, 4b will be collectively referred to as the second indoor unit 4.

[0043] The secondary refrigerant circuit 40 includes a second indoor unit 4 and a circulation pump 44. The second indoor unit 4 has an indoor heat exchanger 41, an indoor fan 42, and an on-off valve 43.

[0044] The indoor heat exchanger 41 is a water-air heat exchanger that exchanges heat between water and the outside air that is drawn into the second indoor unit 4 by the rotation of the indoor fan 42. The inlet side of the indoor heat exchanger 41 is connected to the water outlet 51d of the water-refrigerant heat exchanger 51 by the first water piping 11. The outlet side of the indoor heat exchanger 41 is connected to the water inlet 51c of the water-refrigerant heat exchanger 51 by the second water piping 12.

[0045] The indoor fan 42 is made of resin and is arranged near the indoor heat exchanger 41. The indoor fan 42 is rotated by a fan motor (not shown) to take in indoor air into the second indoor unit 4 from an intake port (not shown) of the second indoor unit 4, and blows the air that has exchanged heat with water in the indoor heat exchanger 41 out into the room from an outlet (not shown) of the second indoor unit 4. The indoor fan 42 and the indoor heat exchanger 41 form a fan coil unit (FCU).

[0046] The on-off valve 43 is disposed in the first water pipe 11 and is a shutoff valve capable of shutting off the flow of water from the water outlet 51d of the water-refrigerant heat exchanger 51 toward the indoor heat exchanger 41. The opening and closing of the on-off valve 43 is controlled individually for each of the second indoor units 4a, 4b, and the on-off valve 43 of the second indoor unit 4 that is not operating (or is to be stopped) is switched to the closed state.

[0047] The on-off valve 43 may be a flow control valve whose opening can be adjusted as desired. In this case, the flow rate of water flowing through the indoor heat exchanger 41 can be controlled according to the opening rate of the flow control valve. This makes it possible to adjust the flow rate of water flowing into the indoor heat exchanger 41 in cases where, for example, the capacity required by the second indoor unit 4 exceeds the capacity required even when the circulation pump 44 is operating at the minimum rotation speed, thereby improving the ability to follow the required capacity and increasing comfort.

[0048] The circulation pump 44 is a variable capacity pump driven by a motor (not shown). When the circulation pump 44 is driven, water flows out from the water outlet 51d of the water-refrigerant heat exchanger 51 into the first water pipe 11, and circulates so that water flows into the water inlet 51c of the water-refrigerant heat exchanger 51 via the indoor heat exchanger 41 and the second water pipe 12.

[0049] The flow rate of water circulated by driving the circulation pump 44 is controlled by the rotation speed of the motor. This allows water to be supplied at the same flow rate to each second indoor unit 4. In the example shown in Figure 1, the circulation pump 44 is arranged in the second water piping 12, but instead, it may be arranged in the first water piping 11, or may be arranged inside the relay unit 50.

[0050] (sensors) Various sensors are provided in the refrigeration cycle apparatus 100. In the outdoor unit 2, a high-pressure sensor 71 that detects the pressure of the refrigerant discharged from the compressor 21 and a discharge temperature sensor 72 that detects the temperature of the refrigerant discharged from the compressor 21 are provided in the discharge pipe 61. A low-pressure sensor 73 that detects the pressure of the refrigerant sucked into the compressor 21 and an suction temperature sensor 74 that detects the temperature of the refrigerant sucked into the compressor 21 are provided in the suction pipe 65.

[0051] The outdoor heat exchanger 23 is provided with a heat exchanger temperature sensor 75 for detecting the temperature of the refrigerant flowing through the outdoor heat exchanger 23. An outdoor air temperature sensor 76 for detecting the temperature of the outdoor air flowing into the outdoor unit 2, i.e., the outdoor air temperature, is provided near an air inlet (not shown) of the outdoor unit 2. The first indoor unit 3 and the second indoor unit 4 are provided with a room temperature sensor 77 for detecting the temperature (room temperature) of the air flowing into the first indoor unit 3 and the second indoor unit 4.

[0052] A first refrigerant temperature sensor 78 is provided in the liquid branch pipe 16 of the relay unit 50 between the second expansion valve 52 and the liquid refrigerant inlet / outlet 51a to detect the temperature of the refrigerant flowing into the water-refrigerant heat exchanger 51 during cooling operation, and a second refrigerant temperature sensor 79 is provided in the gas branch pipe 17 to detect the temperature of the refrigerant flowing into the water-refrigerant heat exchanger 51 during heating operation. A third refrigerant sensor 81 is provided in the indoor unit liquid pipe 38 of the first indoor unit 3 to detect the temperature of the refrigerant flowing into the indoor heat exchanger 31 during cooling operation (or the temperature of the refrigerant flowing out of the indoor heat exchanger 31 during heating operation), and a fourth refrigerant temperature sensor 82 is provided in the indoor unit gas pipe 39 to detect the temperature of the refrigerant flowing into the indoor heat exchanger 31 during heating operation (or the temperature of the refrigerant flowing out of the indoor heat exchanger 31 during cooling operation). A water temperature sensor 80 is provided in the second water pipe 12 connected to the water inlet 51c of the water-refrigerant heat exchanger 51 to detect the temperature of the water flowing into the water-refrigerant heat exchanger 51. The first refrigerant temperature sensor 78 and the second refrigerant temperature sensor 79 correspond to a primary refrigerant temperature detection unit that detects the temperature of the refrigerant flowing into the water-refrigerant heat exchanger 51. The water temperature sensor 80 corresponds to a secondary refrigerant temperature detection unit that detects the temperature of the water flowing into the water-refrigerant heat exchanger 51.

[0053] (Control device) The control device 90 is, for example, an outdoor unit control device provided in the outdoor unit 2, and is mounted on a control board housed in an electrical component box (not shown) of the outdoor unit 2.

[0054] 2 is a block diagram showing the configuration of the control device 90. As shown in the figure, the control device 90 has a CPU 91, a storage unit 92, a communication unit 93, a sensor input unit 94, and a rotation speed detection unit 95.

[0055] The memory unit 92 is a non-volatile memory such as a flash memory, and stores the control program and control parameters of the outdoor unit 2, detection values ​​corresponding to detection signals from various sensors, the control states of the compressor 21 and outdoor fan 29, etc., the rotation speeds of the indoor fans 32, 42 obtained via the communication unit 93, the control states of the first indoor unit 3 and the second indoor unit 4, including the operation mode set and input by the user, etc.

[0056] The communication unit 93 is an interface for communicating with the first indoor unit 3, the second indoor unit 4, and the relay unit 50. The sensor input unit 94 takes in detection results from various sensors in the outdoor unit 2 and outputs them to the CPU 91. The rotation speed detection unit 95 detects the rotation speed of the motor of the compressor 21 and outputs it to the CPU 91. The rotation speed detection unit 95 may be configured to directly detect the rotation speed of the motor using an encoder or the like attached to the drive shaft of the motor, or may be configured to detect the rotation speed of the motor from the drive current supplied to the motor. In the following description, the rotation speed of the compressor 21 refers to the rotation speed of the motor.

[0057] The CPU 91 is a control unit that controls the operation of each part of the outdoor unit 2, including the compressor 21, by executing a program stored in the storage unit 92. The program is installed in the control device 90 via, for example, various storage media. Alternatively, the program may be installed via the Internet or the like.

[0058] The CPU 91 takes in the detection results of each sensor in the outdoor unit 2 described above via the sensor input unit 94. Furthermore, the CPU 91 takes in control signals transmitted from the first indoor unit 3 and the second indoor unit 4 via the communication unit 93. The control signals transmitted from the first indoor unit 3 and the second indoor unit 4 include the necessary operating capacity (hereinafter also referred to as required capacity) requested by the first indoor unit 3 and the second indoor unit 4. Details of the required capacity will be described later.

[0059] Based on the captured detection results and control signals, the CPU 91 controls the drive of the compressor 21, the outdoor fan 29, the indoor fans 32 and 42, and the circulation pump 44, for example, setting the command rotation speeds at which these are driven. The CPU 91 also controls the switching of the four-way valve 22 based on the captured detection results and control signals. Furthermore, the CPU 91 controls the opening degrees of the outdoor expansion valve 24, the first expansion valve 33, and the second expansion valve 52, and controls the opening and closing of the on-off valve 43, based on the captured detection results and control signals.

[0060] [Basic operation of refrigeration cycle equipment] Next, a description will be given of the basic operation of the refrigeration cycle apparatus 100. Hereinafter, the operation of the refrigeration cycle apparatus 100 during cooling operation and heating operation will be described.

[0061] (Cooling operation) When the refrigeration cycle apparatus 100 performs cooling operation (cooling operation mode), the four-way valve 22 is switched to the state shown by the solid lines in Fig. 1, i.e., the state where port a and port b are connected and port c and port d are connected, and the compressor 21 and the circulation pump 44 are driven in this state. Driving the compressor 21 causes refrigerant to circulate through the refrigerant circuit 20, and driving the circulation pump 44 causes water to circulate through the water circuit 40. As a result, the outdoor heat exchanger 23 functions as a condenser, and the indoor heat exchanger 31 and the water-refrigerant heat exchanger 51 function as evaporators.

[0062] The rotation speed of the compressor 21 and the flow rate of the circulation pump 44 are determined according to the capacity required by the first indoor unit 3 and the second indoor unit 4. Here, an example will be described in which all indoor units (first indoor unit 3, second indoor unit 4) perform indoor cooling.

[0063] The refrigerant compressed by the compressor 21 to a high temperature and high pressure is discharged from the compressor 21, flows through the discharge pipe 61, and flows into the four-way valve 22, and then flows from the four-way valve 22 into the refrigerant piping 62 and into the outdoor heat exchanger 23. The refrigerant that has flowed into the outdoor heat exchanger 23 exchanges heat with outside air that has been drawn into the outdoor unit 2 by the rotation of the outdoor fan 29, and is condensed.

[0064] The refrigerant flowing out from the outdoor heat exchanger 23 flows through the outdoor unit liquid pipe 63 and passes through the outdoor expansion valve 24. A portion of the refrigerant that has passed through the outdoor expansion valve 24 is decompressed when it flows through the liquid pipe 36 and passes through the first expansion valve 33. The other portion of the refrigerant that has passed through the outdoor expansion valve 24 is decompressed when it flows through the liquid branch pipe 16 and passes through the second expansion valve 52.

[0065] Here, the outdoor expansion valve 24 is, for example, fully open. The first expansion valve 33 is opened to an evaporating pressure corresponding to the evaporating temperature in the indoor heat exchanger 31, more specifically, to an evaporating temperature lower than the lowest value (e.g., 18°C) of the air conditioning temperature (set temperature) set in the first indoor unit 3. The second expansion valve 52 is opened to an evaporating pressure corresponding to the evaporating temperature in the water-refrigerant heat exchanger 51 to achieve the set temperature during cooling operation in the room where the second indoor unit 4 is installed, more specifically, to an evaporating temperature such that the evaporating temperature in the water-refrigerant heat exchanger 51 and the temperature of the water flowing out of the water-refrigerant heat exchanger 51 are lower than the lowest value (e.g., 18°C) of the air conditioning temperature (set temperature) set in the second indoor unit 4.

[0066] The refrigerant that has passed through the first expansion valve 33 flows into the indoor heat exchanger 31 via the indoor unit liquid pipe 38. The refrigerant that has flowed into the indoor heat exchanger 31 exchanges heat with indoor air that has been drawn into the first indoor unit 3 by the rotation of the indoor fan 32 and evaporates, thereby cooling the room in which the first indoor unit 3 is installed. The refrigerant that has flowed out of the indoor heat exchanger 31 flows into the outdoor unit gas pipe 64 via the indoor unit gas pipe 39 and gas pipe 37, and returns to the compressor 21.

[0067] The refrigerant that has passed through the second expansion valve 52 flows into the liquid refrigerant inlet / outlet 51a of the water-refrigerant heat exchanger 51 via the liquid branch pipe 16. The refrigerant that has flowed into the liquid refrigerant inlet / outlet 51a passes through the refrigerant-side flow path 511 and exchanges heat with water flowing through the water-side flow path 512, thereby evaporating, and flows from the gas refrigerant inlet / outlet 51b of the water-refrigerant heat exchanger 51 through the gas branch pipe 17 into the outdoor unit gas pipe 64. The refrigerant that has flowed into the outdoor unit gas pipe 64 flows through the four-way valve 22, refrigerant piping 66, accumulator 25, and suction pipe 65, and is sucked into the compressor 21 and compressed again.

[0068] On the other hand, the water cooled while flowing through the water-side flow path 512 flows into the first water piping 11 from the water outlet 51d of the water-refrigerant heat exchanger 51. The water that has flowed into the first water piping 11 flows into the indoor heat exchanger 41 of the second indoor unit 4 via the open on-off valve 43, and cools the indoor air passing through the indoor heat exchanger 41 by the rotation of the indoor fan 42. This cools the room in which the second indoor unit 4 is installed.

[0069] The water flowing out from the indoor heat exchanger 41 of each second indoor unit 4 is drawn into the circulation pump 44 via the second water pipe 12. The water drawn into the circulation pump 44 is sent to the water inlet 51c of the water-refrigerant heat exchanger 51, passes through the water-side flow path 512, and is cooled again by the refrigerant flowing in the refrigerant-side flow path 511, and then flows out from the water outlet 51d toward the second indoor unit 4.

[0070] (Heating operation) When the refrigeration cycle apparatus 100 performs heating operation (heating operation mode), the four-way valve 22 is switched to the state shown by the dashed lines in Fig. 1, i.e., the state where port a and port d are connected and port b and port c are connected, and the compressor 21 and the circulation pump 44 are driven in this state. Driving the compressor 21 causes refrigerant to circulate through the refrigerant circuit 20, and driving the circulation pump 44 causes water to circulate through the water circuit 40. As a result, the outdoor heat exchanger 23 functions as an evaporator, and the indoor heat exchanger 31 and the water-refrigerant heat exchanger 51 function as condensers.

[0071] The rotation speed of the compressor 21 and the flow rate of the circulation pump 44 are determined according to the capacity required by the first indoor unit 3 and the second indoor unit 4. Here, an example will be described in which all indoor units (first indoor unit 3, second indoor unit 4) perform indoor heating.

[0072] The refrigerant compressed by the compressor 21 to a high temperature and high pressure is discharged from the compressor 21, flows through the discharge pipe 61, and flows into the four-way valve 22, and from the four-way valve 22 flows into the gas pipe 37 and the gas branch pipe 17 via the outdoor unit gas pipe 64.

[0073] The refrigerant that has flowed into the gas pipe 37 flows into the indoor heat exchanger 31 via the indoor unit gas pipe 39. The refrigerant that has flowed into the indoor heat exchanger 31 exchanges heat with the indoor air that has been drawn into the first indoor unit 3 by the rotation of the indoor fan 32 and condenses, thereby heating the room in which the first indoor unit 3 is installed. The refrigerant that has flowed out of the indoor heat exchanger 31 is decompressed by the first expansion valve 33, and flows into the outdoor unit liquid pipe 63 via the indoor unit liquid pipe 38 and liquid pipe 36.

[0074] At this time, the opening degree of the first expansion valve 33 is set so that the subcooling (degree of supercooling) of the refrigerant flowing out of the indoor heat exchanger 31 becomes the target subcooling, and more specifically, the opening degree is set so that the refrigerant flowing into the first expansion valve 33 becomes a liquid single-phase refrigerant that has been completely condensed in the indoor heat exchanger 31.

[0075] On the other hand, the refrigerant that has flowed into the gas branch pipe 17 flows into the gas refrigerant inlet / outlet 51b of the water-refrigerant heat exchanger 51. The refrigerant that has flowed into the gas refrigerant inlet / outlet 51b passes through the refrigerant-side flow path 511 and heats the water flowing in the water-side flow path 512. The refrigerant condensed by heat exchange with the water flowing in the water-side flow path 512 flows out from the liquid-side inlet / outlet 51a of the water-refrigerant heat exchanger 51 into the liquid branch pipe 16, is decompressed by the second expansion valve 52, and flows into the outdoor unit liquid pipe 63.

[0076] At this time, the opening degree of the second expansion valve 52 is set so that the subcooling (degree of supercooling) of the refrigerant flowing out of the water-refrigerant heat exchanger 51 becomes a target subcooling in order to achieve the set temperature during heating operation in the room where the second indoor unit 4 is installed, and more specifically, the opening degree is set so that the refrigerant flowing into the second expansion valve 52 becomes a liquid single-phase refrigerant that has been completely condensed in the water-refrigerant heat exchanger 51.

[0077] The water heated while flowing through the water-side flow path 512 flows into the first water piping 11 from the water outlet 51d of the water-refrigerant heat exchanger 51. The water that has flowed into the first water piping 11 flows into the indoor heat exchanger 41 via the open on-off valve 43, and heats the indoor air passing through the indoor heat exchanger 41 by the rotation of the indoor fan 42. This heats the room in which the second indoor unit 4 is installed.

[0078] The water flowing out of the indoor heat exchanger 41 flows into the second water pipe 12 and is sucked into the circulation pump 44. The water sucked into the circulation pump 44 is sent to the water inlet 51c of the water-refrigerant heat exchanger 51, passes through the water-side flow path 512, and is heated again by the refrigerant flowing in the refrigerant-side flow path 511, and then flows out from the water outlet 51d toward the second indoor unit 4.

[0079] Meanwhile, the refrigerant that has flowed into the outdoor unit liquid pipe 63 passes through the outdoor expansion valve 24 and flows into the outdoor heat exchanger 23. The refrigerant that has flowed into the outdoor heat exchanger 23 evaporates by exchanging heat with outside air that has been drawn into the outdoor unit 2 by the rotation of the outdoor fan 29. The refrigerant that has flowed out of the outdoor heat exchanger 23 flows through the refrigerant piping 62, and is drawn into the compressor 21 via the four-way valve 22, refrigerant piping 66, accumulator 25, and suction pipe 65, where it is compressed again. The opening of the outdoor expansion valve 24 is controlled to be fully open or to an opening such that the temperature of the refrigerant discharged from the compressor 21 becomes a target discharge temperature.

[0080] [Controller details] The control device 90 controls the rotation speed of the compressor 21, the flow rate of the circulation pump 44, and the opening of the first expansion valve 33 and the second expansion valve 52, respectively, according to the capacity requirements of the first indoor unit 3 and the second indoor unit 4. For example, during cooling or heating operation, the control device 90 determines whether the indoor temperature has reached a set temperature, and stops operation of the indoor unit installed in the room where the set temperature has been reached (hereinafter also referred to as thermo-off). At this time, the control device 90 fully closes or slightly opens the expansion valve corresponding to the indoor unit whose operation is to be stopped, thereby stopping the flow of refrigerant through the indoor heat exchanger of that indoor unit.

[0081] Here, the capacity required from the indoor units refers to the capacity required for the room temperature to reach the set temperature, or the capacity required to maintain the room temperature at that set temperature once it has reached that temperature. The capacity required from the indoor units is calculated based on the difference between the room temperature and the set temperature. In the following explanation, the capacity required from the first indoor unit 3 refers to the sum of the capacity required from the first indoor unit 3a and the capacity required from the first indoor unit 3b. Similarly, the capacity required from the second indoor unit 4 refers to the sum of the capacity required from the second indoor unit 4a and the capacity required from the second indoor unit 4b.

[0082] On the other hand, because the relay unit 50 is connected to the second indoor unit 4, the capacity required from the relay unit 50 corresponds to the capacity required from the second indoor unit 4. That is, in the example of Fig. 1, the capacity required from the relay unit 50a corresponds to the capacity required from the second indoor unit 4a, and the capacity required from the relay unit 50b corresponds to the capacity required from the second indoor unit 4b. Therefore, in the following explanation, the capacity required from the relay unit 50 refers to the sum of the capacity required from the second indoor unit 4a and the capacity required from the second indoor unit 4b.

[0083] In the following explanation, the first indoor unit 3 is also referred to as a direct expansion terminal or a direct expansion terminal type indoor unit, and the second indoor unit 4 is also referred to as an indirect expansion terminal or an indirect expansion terminal type indoor unit. A direct expansion terminal is an indoor unit used in a system where heat is exchanged by expanding a refrigerant near the space to be air-conditioned, and an indirect expansion terminal is an indoor unit used in a system where cooling / heating is performed by transporting water cooled or heated by a refrigerant expanded on the heat source side.

[0084] In a refrigeration cycle device in which a direct expansion terminal type indoor unit and a partial expansion terminal type indoor unit are connected in parallel to an outdoor unit, the update interval of the feedback control, which adjusts the compressor rotation speed etc. in accordance with the required capacity transmitted from each indoor unit, is set according to the responsiveness of the controlled object, and when there are multiple controlled objects, it is generally set according to the one with the worst responsiveness.

[0085] For example, Figure 3 shows the relationship between room temperature changes at the direct expansion terminal and at the intermediate expansion terminal in response to changes in the refrigerant condensing temperature. As shown in the figure, there is a difference in responsiveness between the direct expansion terminal and the intermediate expansion terminal to the same change in refrigerant temperature. This is because the direct expansion terminal transports heat from the refrigerant to the air, while the intermediate expansion terminal transports heat from the refrigerant to water and from water to air, and because the thermal time constants of air and water differ. Because the time (responsiveness) required to reach the same room temperature from the condensing temperature differs between the direct expansion terminal and the intermediate expansion terminal, calculating the required capacity using the same update time will not allow optimal control for each terminal. In other words, if the update interval is shorter than the thermal time constant, excessive capacity will occur, and if the update interval is longer than the thermal time constant, start-up will be delayed. Generally, in air conditioners in which direct expansion terminals and intermediate expansion terminals are operated simultaneously, the update interval for the feedback control is set to match the intermediate expansion terminal, which has poorer responsiveness than the direct expansion terminal.

[0086] However, if the update interval of the feedback control is set to match the expansion terminal, the update interval will be longer than the thermal time constant of the direct expansion terminal, which will lengthen the time it takes for the temperature in the room where the direct expansion terminal is installed to reach the set temperature, resulting in a problem of reduced comfort. Conversely, if the update interval of the feedback control is set to match the direct expansion terminal, the update interval will be shorter than the thermal time constant of the direct expansion terminal, which will result in an overcalculation of the required capacity from the expansion terminal, resulting in an excessive capacity of the expansion terminal and a decrease in comfort in the room where the expansion terminal is installed. To solve these problems, the control device 90 in this embodiment is configured as follows.

[0087] First Embodiment 4 is a functional block diagram showing the configuration of the CPU 91 of the control device 90. The control device 90 is a specific example of the control means of the present invention. The CPU 91 has a terminal identifying unit 911 and a control pattern determining unit 912.

[0088] The operating status includes whether each of the indoor units 3a, 3b, 4a, and 4b is operating or stopped (including thermo-off). Each of the indoor units 3a, 3b, 4a, and 4b is assigned a unique ID (identifier), and the terminal identification unit 911 identifies the operating status of each indoor unit based on the ID.

[0089] Based on the operating state of each indoor unit, the terminal identification unit 911 identifies the indoor units as "direct expansion" when all of the operating indoor units are first indoor units 3, and identifies the indoor units as "intermediate expansion" when the operating indoor units include at least one second indoor unit 4. Information relating to the identification result of whether it is "direct expansion" or "intermediate expansion" is hereinafter also referred to as identification information.

[0090] The terminal identification unit 911 generates identification information according to the operating state of each indoor unit at predetermined time intervals (for example, at each update timing of the rotation speed control of the compressor 21) and stores the results in the storage unit 92 (see FIG. 2). The identification information stored in the storage unit 92 may be updated every time the predetermined time intervals are reached (including when there is no change in the identification result), or may be updated only when there is a change in the identification result.

[0091] The control pattern determination unit 912 determines a control pattern for the rotation speed of the compressor 21 according to the identification information of the terminal identification unit 911 and the sum of the required capacities from the first indoor unit 3 and the relay unit 50.

[0092] The control pattern for the rotation speed of the compressor 21 includes the rotation speed of the compressor 21 and a control time for the rotation speed of the compressor 21. The control time for the rotation speed of the compressor 21 may typically be a control interval (update interval) for the rotation speed of the compressor 21, or may be a rate of change (speed of change) for the rotation speed of the compressor 21. The following description will mainly take as an example a case where the control time for the rotation speed of the compressor 21 is the control interval.

[0093] The control pattern determination unit 912 further determines the rotation speed of the compressor 21 based on the sum of the required capacity from the first indoor unit 3 and the required capacity from the relay unit 50. The sum of the required capacity from the first indoor unit 3 and the required capacity from the relay unit 50 means the sum of the required capacity from the first indoor unit 3 and the required capacity from the second indoor unit 4.

[0094] For example, the required capacity from the first indoor unit 3 corresponds to the required capacity Pd from the direct expansion terminal at the update time T in Figure 3, the required capacity from the relay unit 50 corresponds to the required capacity Pi from the intermediate expansion terminal at the update time T in Figure 3, and the sum of the required capacity from the first indoor unit 3 and the required capacity from the second indoor unit 4 corresponds to Pd + Pi.

[0095] The control pattern determination unit 912 calculates the required capacity Pd from the first indoor unit 3 and the required capacity Pi from the relay unit 50 at predetermined time intervals (for example, at each update timing of the rotation speed control of the compressor 21), and controls the rotation speed at the update timing of the rotation speed of the compressor 21.

[0096] The storage unit 92 (see FIG. 2) stores a rotation speed table of the compressor 21 that is set in advance according to the above sum. FIG. 5 shows an example of this rotation speed table. The rotation speed table shown in the figure classifies code values ​​(total capacity code Crt) that indicate required capacity into arbitrary ranges, and sets different values ​​of rotation speed (compressor rotation speed R) for each classification. The control pattern determination unit 912 determines to which classification the code value (total capacity code Crt), which is the sum of the required capacity from the first indoor unit 3 and the required capacity from the relay unit 50, belongs, and outputs a control command to the compressor 21 to rotate the compressor 21 at a rotation speed value that corresponds to the determined classification (see FIG. 4).

[0097] The control interval for the rotation speed of the compressor 21 is determined according to the identification information of the terminal identification unit 911 (identification information stored in the storage unit 92). As the control interval, one control time may be selected from a plurality of preset control times according to the identification information. The plurality of preset control times may include, for example, a first control time and a second control time longer than the first control time. The first control time is a control time (e.g., 60 seconds) corresponding to the thermal time constant (response of room temperature change to refrigerant temperature change; the same applies below) of the first indoor unit 3, which is a direct expansion terminal, and the second control time is a control time (e.g., 120 seconds) corresponding to the thermal time constant of the second indoor unit 4, which is a partial expansion terminal.

[0098] The control pattern determination unit 912 refers to the identification information stored in the storage unit 92 (see FIG. 2) at predetermined time intervals (for example, at each update timing of the rotation speed control of the compressor 21), and determines, based on the identification information, the control interval for the rotation speed of the compressor 21. The determined control interval is reflected at the next update timing.

[0099] As a method for determining the control interval, for example, when only the first indoor unit 3 is in operation, the control pattern determination unit 912 selects the first control time as the control interval, thereby shortening the control interval for the rotation speed of the compressor 21 compared to when only the relay unit 50 (i.e., only the second indoor unit 4) is in operation. In this case, the control interval for the rotation speed of the compressor 21 is adopted in accordance with the thermal time constant of the first indoor unit 3, which is the direct expansion terminal, and therefore comfort can be improved by preventing the time until the temperature in the room where the first indoor unit is installed reaches the set temperature from being unnecessarily long.

[0100] On the other hand, when only the relay unit 50 is operating, the control pattern determination unit 912 selects the second control time as the control interval, thereby making the control interval for the rotation speed of the compressor 21 longer than when only the first indoor unit 3 is operating. In this case, because the control interval for the rotation speed of the compressor 21 is adopted in accordance with the responsiveness of the second indoor unit, which is the intermediate expansion terminal, it is possible to avoid overcalculating the required capacity of the second indoor unit 4, thereby suppressing a decrease in comfort and energy efficiency in the room where the second indoor unit 4 is installed.

[0101] Furthermore, when both the first indoor unit 3 and the second indoor unit 4 are in operation, the control pattern determination unit 912 may select the second control time as the control interval to match the update interval of the second indoor unit 4, which has a slower response speed, or may determine the control interval for the rotation speed of the compressor 21 according to the ratio between the number of operating first indoor units 3 and the number of operating second indoor units 4. More specifically, a control interval is selected that matches the indoor unit with the greater number of operating first indoor units 3 or second indoor units 4.

[0102] For example, when the number of operating first indoor units 3 is greater than the number of operating second indoor units 4, the control pattern determination unit 912 selects the first control time as the control interval, thereby shortening the control time compared to when the number of operating first indoor units 3 is fewer than the number of operating second indoor units 4. Conversely, when the number of operating second indoor units 4 is greater than the number of operating first indoor units 3, the control pattern determination unit 912 selects the second control time as the control interval, thereby lengthening the control time compared to when the number of operating second indoor units 4 is fewer than the number of operating first indoor units 3.

[0103] In this way, by determining the control time of the rotation speed of the compressor 21 based on the indoor unit that accounts for the majority of the number of operating units, either the first indoor unit 3 (direct expansion terminal) or the second indoor unit 4 (intermediate expansion terminal), it is possible to increase the comfort of the majority of users who are expected to represent the above proportion of all users.

[0104] Fig. 6 shows an example of the relationship between each pattern of the number of operating first indoor units 3 (direct expansion terminals) and second indoor units 4 (intermediate expansion terminals) and the control interval of the compressor rotation speed. Two methods for determining the control interval are shown here: Method 1 and Method 2. The number of first indoor units 3 and second indoor units 4 is shown as a maximum of six each.

[0105] In method 1, the control interval is determined according to the type of terminal identified by the terminal identification unit 911. "Identification" corresponds to the identification information of the terminal identification unit 911, and is determined to be "direct expansion" when all of the operating indoor units are first indoor units 3 (patterns 1 and 5), and is determined to be "intermediate expansion" when the operating indoor units include at least one second indoor unit 4 (patterns 2 to 4, 6 and 7). In method 1, the control pattern determination unit 912 determines the control interval for the rotation speed of the compressor 21 to be 60 seconds (first control time) when the identification information of the terminal identification unit 911 is "direct expansion," and determines the control interval to be 120 seconds (second control time) when the identification information is "intermediate expansion."

[0106] Method 2 is a method of identifying the type according to the ratio of the number of operating second indoor units 4 to the total number of operating indoor units, and determining the control interval according to the identification result. The "inter-expansion ratio" indicates the ratio of the number of operating second indoor units 4 (inter-expansion terminals) to all operating indoor units. In method 2, the control pattern determination unit 912 determines the control interval to be 60 seconds (first control time) when the inter-expansion ratio is less than 50% (patterns 1, 4 to 6), and determines the control interval to be 120 seconds (second control time) when the inter-expansion ratio is 50% or more (patterns 2, 3, 7).

[0107] Method 1 can be said to prioritize ensuring the comfort of users of the second indoor unit 4, which is the intermediate expansion terminal, while Method 2 can be said to prioritize the comfort of users determined according to the ratio of the number of operating units. Note that in Method 2, the control interval is determined based on an intermediate expansion ratio of 50% as an example, but the reference for the intermediate expansion ratio is not limited to 50%.

[0108] Whether to adopt the above-mentioned Method 1 or Method 2 can be selected arbitrarily depending on the installation environment of the first indoor unit 3 and the second indoor unit 4 or the relay unit 50. Similarly, the standard for the expansion ratio (50%) adopted in the above-mentioned Method 2 can also be changed arbitrarily depending on the installation environment of the first indoor unit 3 and the second indoor unit 4 or the relay unit 50.

[0109] (Size of the space where the indoor unit will be installed) For example, as shown in Figure 7, consider a case where seven direct expansion terminal-type indoor units (corresponding to first indoor unit 3) are operating in an office, and one intermediate expansion terminal-type indoor unit (corresponding to second indoor unit 4) is operating in each of three conference rooms A, B, and C. In this case, because the proportion of intermediate expansion terminals is 30% in the above-mentioned method 2, the control interval is determined to be the control time targeting the direct expansion terminals (first control time). However, because each conference room is spatially smaller than the office, the first control time is likely to result in excessive control, which could significantly reduce the comfort of conference room users. Therefore, taking into account the size of the space between the office and the conference rooms, method 1 can be used when an intermediate expansion terminal is operating in any of the conference rooms, and the control interval can always be the control time targeting the intermediate expansion terminals (second control time).

[0110] (Frequency of indoor unit use) If there is a room where a direct expansion terminal type indoor unit (corresponding to the first indoor unit 3) is installed and a room where a partial expansion terminal type indoor unit, the second indoor unit 4, is installed, and both indoor units are operating, the control time for the rotation speed of the compressor 21 may be determined at a control interval corresponding to the type of indoor unit (direct expansion or partial expansion) installed in the room that is used more frequently. Since it is believed that rooms that are used more frequently have more occupants, adopting a control interval corresponding to the type of indoor unit installed in the room that is used more frequently can prevent a decrease in comfort for those occupants. The frequency of use of each room can be calculated based on, for example, the operation history and total operating time of each indoor unit, the use history of each room, etc.

[0111] (Installation environment of the relay unit) The thermal time constant of the expansion terminal also varies depending on the length of the water pipes 11, 12 connecting the relay unit 50 and the second indoor unit 4, the amount of water circulating through the water circuit 40, and other factors. For example, the longer the length of the water pipes 11, 12, the greater the amount of water in the water circuit 40, which increases the time it takes for a change in the rotation speed of the compressor 21 to manifest as a change in room temperature (response becomes poor). For this reason, the control interval (second control time) for the expansion terminal may be variably set according to the pipe length and water volume. In this way, by taking into account the installation information of the relay unit 50, which affects control responsiveness, the control time can be set more appropriately, thereby minimizing any deterioration in comfort for users of the expansion terminal. The installation information, including the pipe length, is stored in the memory unit 92 (see FIG. 2).

[0112] (Control by the rate of change of the compressor rotation speed) Up to this point, an example has been described in which the control time for the rotation speed of the compressor 21 is the control interval, but the control time may also be the rate of change (speed of change) of the rotation speed of the compressor 21. For example, the control interval may be set to a control interval corresponding to a direct expansion terminal (e.g., 60 seconds), and the rate of change of the rotation speed of the compressor 21 for the direct expansion terminal may be set to be slower (e.g., 0.5 rps per second) than the rate of change for a direct expansion terminal (e.g., 1 rps per second). In the following explanation, an example will be described in which the control interval is set to 60 seconds and the control pattern determination unit 912 issues an instruction to increase the rotation speed of the compressor 21 by 60 rps.

[0113] If the rate of change of the rotation speed of the compressor 21 is 1 rps per second, the rotation speed of the compressor 21 will increase by 60 rps by the time of the next control. However, in an intermediate expansion terminal with a large thermal time constant, part of the change in the rotation speed of the compressor 21 (for example, 30 rps) is not reflected in the room temperature, so in the next control, the required capacity of the intermediate expansion terminal may be overcalculated, resulting in excessive control.

[0114] On the other hand, if the rate of change of the rotation speed of the compressor 21 is set to 0.5 rps per second, the rotation speed of the compressor 21 will increase by 30 rps until the next control. As a result, even at an intermediate expansion terminal with a large thermal time constant, the amount of change in the rotation speed of the compressor 21 that is not reflected in the room temperature will be small (for example, 15 rps), and excessive control can be suppressed.

[0115] Furthermore, in the next feedback control, the required capacity of the terminal expansion type indoor unit may be calculated taking into account the amount of change in the rotation speed of the compressor 21 that is not reflected in the room temperature. By performing such control, the required capacity can be calculated accurately, allowing for more appropriate feedback control.

[0116] <Second embodiment> In the first embodiment described above, the timing of the feedback control was the same for the direct expansion terminal and the intermediate expansion terminal, but in this embodiment, the update interval of the feedback control is made different for the direct expansion terminal and the intermediate expansion terminal, thereby achieving both comfort for the direct expansion terminal and the intermediate expansion terminal.

[0117] 8 is a functional block diagram showing the configuration of a CPU 91A of a control device 90 in this embodiment. The control device 90 is a specific example of a control means in the present invention. The CPU 91A has a terminal identification unit 911, a control pattern determination unit 912, and a mask determination unit 913. That is, this embodiment differs from the first embodiment in that it has the mask determination unit 913.

[0118] The mask determination unit 913 determines whether the relay unit 50 is in operation based on the identification information of the terminal identification unit 911, and if the relay unit 50 is in operation, masks the input of the required capacity from the relay unit 50 at a predetermined interval.

[0119] 9 is an explanatory diagram showing an example of a mask for the input of the required capacity from the intermediate expansion terminal. In the figure, black circles indicate the input of the required capacity from the direct expansion terminal, and white circles indicate the input of the required capacity from the intermediate expansion terminal. Here, an example will be explained in which the control interval for the rotation speed of the compressor 11 is 60 seconds.

[0120] At times T1, T3, and T5 in Fig. 9, the control pattern determination unit 912 calculates a total capacity code Crt (Fig. 5) as the sum of the required capacity Pd (Fig. 3) from the first indoor unit 3 and the required capacity Pi (Fig. 3) from the relay unit 50, and determines the rotation speed corresponding to that calculated value. On the other hand, at times T2 and T4, the input of the required capacity from the relay unit 50 is masked, so the control pattern determination unit 912 calculates a total capacity code Crt using only the required capacity Pd from the first indoor unit 3, and determines the rotation speed corresponding to that calculated value. That is, in this example, the required capacity from the relay unit 50 is masked at 120-second intervals.

[0121] As described above, according to this embodiment, in the second indoor unit 4, which is the intermediate expansion terminal, excess capacity can be prevented by calculating the required capacity before reacting to the results of the capacity adjustment, and in the first indoor unit 3, which is the direct expansion terminal, capacity adjustment can be made to match its thermal time constant. This makes it possible to adjust the operating capacity at control intervals suitable for both the direct expansion terminal and the intermediate expansion terminal.

[0122] Note that when the required capacity from the relay unit 50 is masked (times T2 and T4), the total capacity code Crt is calculated using only the required capacity Pd from the first indoor unit 3 (i.e., Pi = 0), but instead of this, the total capacity code value Crt may be calculated as a value obtained by adding the previously calculated required capacity Pi from the relay unit 50 to the required capacity Pd from the first indoor unit 3. Alternatively, the total capacity code value Crt may be calculated as a value obtained by adding the difference (ΔPi) between the current required capacity Pi from the relay unit 50 and the previous required capacity Pi to the required capacity Pd from the first indoor unit 3.

[0123] Furthermore, the interval at which the required capacity Pi from the relay unit 50 is masked may be changed according to the ratio of the number of operating inter-expansion terminals. In other words, the mask determination unit 913 may determine whether or not to mask the input of the required capacity from the relay unit 50 according to the ratio of the number of operating first indoor units 3 to the number of operating second indoor units 4.

[0124] For example, only when the direct expansion ratio is less than 50% (patterns 4 and 6 in FIG. 6), the control interval for the rotation speed of the compressor 11 may be set to the first control time (60 seconds), while masking the requested capacity from the direct expansion terminal (relay unit 50). This allows the operating capacity of the direct expansion terminals (first indoor units 3), which account for more than half of all indoor units in operation, to be adjusted at control intervals according to their thermal time constants, thereby preventing a decrease in indoor comfort on the direct expansion terminal side.

[0125] Furthermore, as described above, the thermal time constant of the expansion terminal also changes depending on the length of the water pipes 11, 12 connecting the relay unit 50 and the second indoor unit 4, the amount of water circulating in the water circuit 40, and the like. For this reason, the mask determination unit 913 may change the frequency (cycle) at which the input of the required capacity of the relay unit 50 is masked, depending on the identification information of the terminal identification unit 911 and the installation information of the relay unit 50 stored in the storage unit 92. For example, when the length of the water pipes 11, 12 is equal to or greater than a predetermined length, the input of the required capacity of the relay unit 50 can be masked more frequently than when the length of the water pipes 11, 12 is less than the predetermined length, thereby preventing a decrease in comfort.

[0126] While the present invention has been described above as an embodiment, it is of course possible to make various modifications to the present invention and to change the heat exchange medium. For example, in the present embodiment, the heat exchange medium is indoor air and water, but the heat exchange medium may be antifreeze. [Explanation of symbols]

[0127] 1...Outdoor unit 3...1st indoor unit 4…Second indoor unit 11...First water pipe 12...Second water pipe 21...Compressor 22...Four-way valve 23…Outdoor heat exchanger 31,41…Indoor heat exchanger 33...First expansion valve 50...Relay unit 52...Second expansion valve 90...Control device 100...Refrigeration cycle device 911...Terminal Identification Unit 912...Control pattern determination unit 913...Mask determination unit

Claims

1. an outdoor unit having a compressor and an outdoor heat exchanger; at least one first indoor unit connected to the outdoor unit, the first indoor unit having a refrigerant heat exchanger for exchanging heat between a refrigerant and air and a first expansion valve; at least one relay unit having a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and a second expansion valve, the relay unit being connected to the outdoor unit in parallel with the first indoor unit; a control means having a terminal identification unit that individually identifies the operating states of the first indoor unit and the relay unit, and that determines a control pattern for the rotation speed of the compressor in accordance with identification information of the terminal identification unit and the sum of the required capacities from the first indoor unit and the relay unit; Equipped with The control means determines a control time for the rotation speed of the compressor in accordance with the identification information of the terminal identification unit. Refrigeration cycle equipment.

2. The refrigeration cycle device according to claim 1, The control means shortens the control time when only the first indoor unit is in operation compared to when only the relay unit is in operation. Refrigeration cycle equipment.

3. The refrigeration cycle device according to claim 1, The system further includes at least one second indoor unit connected to the relay unit via a water pipe and having a water-air heat exchanger for exchanging heat between water and air and a flow control valve, the terminal identification unit identifies the operating state of the second indoor unit as the operating state of the relay unit, The control means determines a control time for the rotation speed of the compressor according to a ratio of the number of operating first indoor units to the number of operating second indoor units. Refrigeration cycle equipment.

4. The refrigeration cycle device according to claim 3, When the number of operating first indoor units is greater than the number of operating second indoor units, the control means shortens the control time compared to when the number of operating first indoor units is less than the number of operating second indoor units. Refrigeration cycle equipment.

5. The refrigeration cycle device according to claim 1, a storage unit that stores, as the control times, a first control time for the first indoor unit and a second control time for the relay unit, the second control time being longer than the first control time; The control means selects either the first control time or the second control time as the control time. Refrigeration cycle equipment.

6. The refrigeration cycle device according to claim 1, at least one second indoor unit connected to the relay unit via a water pipe and having a water-air heat exchanger for exchanging heat between water and air and a flow control valve; a storage unit that stores a history of usage conditions of the first indoor unit and the second indoor unit, the terminal identification unit identifies the operating state of the second indoor unit as the operating state of the relay unit, The control means determines the control time for the indoor unit that is more frequently used out of the first indoor unit and the second indoor unit that are in operation. Refrigeration cycle equipment.

7. The refrigeration cycle device according to claim 1, further comprising a storage unit that stores installation information of the first indoor unit and the relay unit, The control means determines the control time in accordance with the identification information and the installation information. Refrigeration cycle equipment.

8. The refrigeration cycle device according to any one of claims 1 to 7, The control means determines, as the control time, a control interval of the rotation speed of the compressor in accordance with the identification information of the terminal identification unit. Refrigeration cycle equipment.

9. The refrigeration cycle device according to any one of claims 1 to 7, The control means determines, as the control time, a rate of change in the number of revolutions of the compressor in accordance with the identification information of the terminal identification unit. Refrigeration cycle equipment.

10. an outdoor unit having a compressor and an outdoor heat exchanger; at least one first indoor unit connected to the outdoor unit, the first indoor unit having a refrigerant heat exchanger for exchanging heat between a refrigerant and air and a first expansion valve; at least one relay unit having a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and a second expansion valve, the relay unit being connected to the outdoor unit in parallel with the first indoor unit; a control means having a terminal identification unit that individually identifies the operating states of the first indoor unit and the relay unit, and that determines a control pattern for the rotation speed of the compressor in accordance with identification information of the terminal identification unit and the sum of the required capacities from the first indoor unit and the relay unit; Equipped with The control means acquires the required capacity at predetermined time intervals, and when the relay unit is in operation, masks the input of the required capacity from the relay unit at predetermined intervals to determine the control time for the rotation speed of the compressor. Refrigeration cycle equipment.

11. The refrigeration cycle apparatus according to claim 10, The system further includes at least one second indoor unit connected to the relay unit via a water pipe and having a water-air heat exchanger for exchanging heat between water and air and a flow control valve, the terminal identification unit identifies the operating state of the second indoor unit as the operating state of the relay unit, The control means determines whether or not to mask the input of the requested capacity from the relay unit in accordance with the ratio between the number of operating first indoor units and the number of operating second indoor units. Refrigeration cycle equipment.

12. The refrigeration cycle apparatus according to claim 10, further comprising a storage unit that stores installation information of the first indoor unit and the relay unit, The control means changes the frequency of masking the input of the required capacity from the relay unit in accordance with the identification information and the installation information. Refrigeration cycle equipment.

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