Air conditioner, heat source module, indoor unit, and method for controlling air conditioner

Abstract

An air conditioning device according to an embodiment of the present invention includes: a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; a secondary refrigerant circuit, through which a secondary refrigerant circulates, the secondary refrigerant circuit including at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a circulation pump; and a control device that controls the compressor. The control device executes one of a room temperature control mode to control a rotation speed of the compressor on the basis of information related to an indoor load and a water temperature control mode to control the rotation speed of the compressor on the basis of information related to a heat load of the secondary refrigerant circuit.

Description

Technical Field

[0001] The present invention relates to an air conditioning device including a relay unit that connects a refrigerant circuit and a water circuit, a heat source module, an indoor unit, and a control method for an air conditioning device.Background Art

[0002] There is known an air conditioning device including: a refrigerant circuit including a compressor that circulates a refrigerant and an outdoor heat exchanger; a water-refrigerant heat exchanger; a water circuit including a pump that circulates water for exchanging heat with the refrigerant; and a plurality of indoor units connected to the water circuit or to the water circuit and the refrigerant circuit. This type of air conditioning device is known for a method of controlling the rotation speed of the compressor on the basis of a temperature difference between a room temperature and a set temperature during heating.Citation ListPatent Literature

[0003] Patent Literature 1: Japanese Patent Application Laid-open No. 2003-65585Disclosure of InventionTechnical Problem

[0004] However, the technology described in Patent Literature 1 assumes that the indoor unit including means for detecting an indoor load, such as a sensor that detects an indoor temperature, is connected. Hence, if an indoor unit without means for detecting an indoor load is connected or if a heating unit of a natural convection system, such as an underfloor heating unit, is connected, the above control cannot be performed.

[0005] In view of the circumstances as described above, it is an object of the present invention to provide an air conditioning device, a heat source module, an indoor unit, and a control method for an air conditioning device, which are capable of performing an operation that follows an indoor load without depending on a function of an indoor unit.Solution to Problem

[0006] An air conditioning device according to an embodiment of the present invention includes: a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; a secondary refrigerant circuit, through which a secondary refrigerant circulates, the secondary refrigerant circuit including at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a circulation pump; and a control device that controls the compressor, in which the control device executes one of a room temperature control mode to control a rotation speed of the compressor on the basis of information related to an indoor load and a water temperature control mode to control the rotation speed of the compressor on the basis of information related to a heat load of the secondary refrigerant circuit.

[0007] The indoor unit may further include a room temperature sensor that detects an indoor temperature, and the control device may store a set temperature of the indoor temperature and may calculate the indoor load on the basis of a difference between the indoor temperature and the set temperature.

[0008] The secondary refrigerant circuit may further include a water temperature sensor that is provided on a downstream side of the water-refrigerant heat exchanger and detects a temperature of the secondary refrigerant, and the control device may store a target temperature of the secondary refrigerant and may calculate the heat load on the basis of a difference between the temperature of the secondary refrigerant and the target temperature.

[0009] The relay unit may further include a reception section that receives an input instruction of a user, and the control device may execute the water temperature control mode, when the input instruction is received via the reception section.

[0010] The secondary refrigerant circuit may include a plurality of the indoor units, and the control device may execute the room temperature control mode by receiving the information related to the indoor load, the information being transmitted from the indoor units, and may execute, when there is one or more of the indoor units, for which transmission of the information related to the indoor load fails to be confirmed, the water temperature control mode to control the rotation speed of the compressor on the basis of the information related to the heat load of the secondary refrigerant circuit.

[0011] A heat source module according to an embodiment of the present invention includes: a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; and a control device that controls the compressor, in which the control device executes one of a room temperature control mode to control a rotation speed of the compressor on the basis of information related to an indoor load, the information being transmitted from at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a water temperature control mode to control the rotation speed of the compressor on the basis of information related to a heat load of the secondary refrigerant circuit.

[0012] An indoor unit according to an embodiment of the present invention is an indoor unit that is connected to the heat source module described above and includes a water heat exchanger connected to the water-refrigerant heat exchanger, the indoor unit including means for detecting the indoor load for causing the control device to execute the room temperature control mode to control the rotation speed of the compressor on the basis of the information related to the indoor load.

[0013] A control method for an air conditioning device according to an embodiment of the present invention is a control method for an air conditioning device that includes a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; and a secondary refrigerant circuit, through which a secondary refrigerant circulates, the secondary refrigerant circuit including at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a circulation pump, the control method comprising: executing, when the outdoor unit receives information related to an indoor load, the information being transmitted from the indoor unit, a room temperature control mode to control a rotation speed of the compressor on the basis of the information related to the indoor load; and executing, when transmission of the information related to the indoor load from the indoor unit fails to be confirmed, a water temperature control mode to control the rotation speed of the compressor on the basis of information related to a heat load of the secondary refrigerant circuit.Advantageous Effects of Invention

[0014] According to the present invention, it is possible to perform an operation that follows an indoor load without depending on a function of an indoor unit.Brief Description of Drawings

[0015] [Fig. 1] Fig. 1 is a refrigerant-water circuit diagram of an air conditioning device according to an embodiment of the present invention. [Fig. 2] Fig. 2 is a block diagram showing a configuration of a control device in the air conditioning device. [Fig. 3] Fig. 3 is a flowchart showing an example of a determination procedure for a control mode of a compressor that is executed by the control device. Mode(s) for Carrying Out the Invention

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.<First Embodiment>[Configuration of Air Conditioning Device]

[0017] Fig. 1 is a refrigerant-water circuit diagram of an air conditioning device 100 according to an embodiment of the present invention. The air conditioning device 100 in this embodiment includes an outdoor unit 2, a plurality of (in this embodiment, three) indoor units 3a, 3b, and 3c (hereinafter, collectively referred to as indoor unit(s) 3, except for the case where they are described individually), a relay unit 50, and a control device 90. In addition, the outdoor unit 2 and the relay unit 50 constitute a heat source module 55 in the air conditioning device 100.(Outdoor Unit)

[0018] The outdoor unit 2 includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an expansion valve 24, and an accumulator 25. Those devices and the relay unit 50 are connected to each other by piping, so that a refrigerant circuit 20 (primary refrigerant circuit) in a refrigerant-water circuit of the air conditioning device 100 is formed. Note that the relay unit 50 will be described later.

[0019] The compressor 21 is a variable capacity compressor whose operating capacity can be varied when the rotation speed is controlled by an inverter (not shown). A refrigerant discharge side of the compressor 21 is connected to a port a of the four-way valve 22 via a discharge pipe 61. In addition, a refrigerant suction side of the compressor 21 is connected to a refrigerant outlet side of the accumulator 25 via a suction pipe 65.

[0020] The four-way valve 22 is a valve for switching the direction in which the refrigerant flows, and includes four ports a, b, c, and d. The port a is connected to the refrigerant discharge side of the compressor 21 via the discharge pipe 61 as described above. The port b is connected to one refrigerant inlet / outlet of the outdoor heat exchanger 23 via a refrigerant pipe 62. The port c is connected to a refrigerant inlet side of the accumulator 25 via a refrigerant pipe 66. The port d is connected to a gas refrigerant inlet / outlet 51b of a water-refrigerant heat exchanger 51 in the relay unit 50, which will be described later, via an outdoor unit gas pipe 64.

[0021] The outdoor heat exchanger 23 exchanges heat between the refrigerant and outside air, which has been taken into the outdoor unit 2 by the rotation of an outdoor fan 29, which will be described later. The one refrigerant inlet / outlet of the outdoor heat exchanger 23 is connected to the port b of the four-way valve 22 via the refrigerant pipe 62 as described above, and the other refrigerant inlet / outlet is connected to a liquid refrigerant inlet / outlet 51a of the water-refrigerant heat exchanger 51 in the relay unit 50, which will be described later, via an outdoor unit liquid pipe 63.

[0022] The expansion valve 24 is, for example, an electronic expansion valve. The expansion valve 24 is disposed in the outdoor unit liquid pipe 63 and capable of adjusting the degree of opening to reduce the pressure of the refrigerant that passes therethrough.

[0023] The outdoor fan 29 is made of resin and is disposed in the vicinity of the outdoor heat exchanger 23. The outdoor fan 29 is driven by a fan motor (not shown) to take in outside air from a suction port (not shown) of the outdoor unit 2 and then release the outside air, which has exchanged heat with the refrigerant in the outdoor heat exchanger 23, to the outside of the outdoor unit 2 from a vent (not shown) of the outdoor unit 2.(Indoor Unit)

[0024] The indoor unit 3 includes an indoor heat exchanger 31, an indoor fan 32, and an on-off valve 33. The indoor units 3a to 3c have the same configuration and form a water circuit 30 (secondary refrigerant circuit) in the refrigerant-water circuit of the air conditioning device 100 by being connected to the relay unit 50. The water circuit 30 includes a circulation pump 34 that circulates water as a secondary refrigerant between the relay unit and each of the indoor units 3a to 3c.

[0025] The indoor heat exchanger 31 is a water heat exchanger that exchanges heat between water and the outside air taken into the indoor unit 3 by the rotation of the indoor fan 32. The inlet side of the indoor heat exchanger 31 is connected to a water outlet 51d of the water-refrigerant heat exchanger 51 of the relay unit 50 via a first water pipe 11 and a first water branching pipe 111 that branches from the first water pipe 11. The outlet side of the indoor heat exchanger 31 is connected to a water inlet 51c of the water-refrigerant heat exchanger 51 via a second water pipe 12 and a second water branching pipe 121 that branches from the second water pipe 12. The circulation pump 34 is disposed in the second water pipe 12.

[0026] The indoor fan 32 is made of resin and is disposed in the vicinity of the indoor heat exchanger 31. The indoor fan 32 is driven by a fan motor (not shown) to take in indoor air from a suction port (not shown) of the indoor unit 3 and then send the air, which has exchanged heat with the water in the indoor heat exchanger 31, to the room from a vent (not shown) of the indoor unit 3. The indoor fan 32 and the indoor heat exchanger 31 constitute a fan coil unit (FCU) together.

[0027] The on-off valve 33 is a shut-off valve disposed in the first water branching pipe 111 and capable of shutting off the flow of water from the water outlet 51d of the water-refrigerant heat exchanger 51 to the indoor heat exchanger 31. The opening and closing of the on-off valve 33 is individually controlled for the indoor units 3a to 3c, and the on-off valve 33 of the indoor unit 3 in which the operation is stopped (or which is caused to stop the operation) is switched to a closed state.

[0028] Note that, instead of the on-off valve 33, a flow rate adjusting valve capable of discretionally adjusting the degree of opening may be used. In this case, it is possible to control the flow rate of the water flowing through the indoor heat exchanger 31 in accordance with the degree of opening of the flow rate adjusting valve. This makes it possible to adjust the flow rate of the water flowing in the indoor heat exchanger 31 in each indoor unit 3, resulting in an improvement in conformability to the requested capacity and an increase in comfort.(Relay Unit)

[0029] The relay unit 50 includes the water-refrigerant heat exchanger 51 and is connected to the outdoor unit 2. Note that in this embodiment, as shown in Fig. 1, the case where the relay unit 50 is installed outside the outdoor unit 2 is descried as an example, but the relay unit 50 may be installed inside the outdoor unit 2.

[0030] The water-refrigerant heat exchanger 51 is, for example, a double pipe heat exchanger and includes a refrigerant-side flow path 511, a water-side flow path 512, the liquid refrigerant inlet / outlet 51a, the gas refrigerant inlet / outlet 51b, the water inlet 51c, and the water outlet 51d.

[0031] One end of the refrigerant-side flow path 511 is connected to the liquid refrigerant inlet / outlet 51a, and the other end thereof is connected to the gas refrigerant inlet / outlet 51b. In addition, one end of the water-side flow path 512 is connected to the water inlet 51c, and the other end thereof is connected to the water outlet 51d. In the water-refrigerant heat exchanger 51, the refrigerant flowing through the refrigerant-side flow path 511 and the water flowing through the water-side flow path 512 exchange heat.

[0032] The liquid refrigerant inlet / outlet 51a is connected to the other refrigerant inlet / outlet of the outdoor heat exchanger 23 via the outdoor unit liquid pipe 63. The gas refrigerant inlet / outlet 51b is connected to the port d of the four-way valve 22 via the outdoor unit gas pipe 64. The water inlet 51c is connected to the indoor heat exchanger 31 of each indoor unit 3 via the second water pipe 12 and the second water branching pipe 121. The water outlet 51d is connected to the indoor heat exchanger 31 of each indoor unit 3 via the first water pipe 11 and the first water branching pipe 111.

[0033] The circulation pump 34 is a variable capacity pump that is driven by a motor (not shown). When the circulation pump 34 is driven, water circulates such that the water flows out from the water outlet 51d of the water-refrigerant heat exchanger unit 51 to the first water pipe 11, and the water flows in the water inlet 51c of the water-refrigerant heat exchanger unit 51 via the first water branching pipe 111, the indoor heat exchanger 31, the second water branching pipe 121, and the second water pipe 12.

[0034] The relay unit 50 further includes a reception section 53 that receives an input instruction by a user. The reception section 53 may be an input operation section that receives an input instruction by a user or may be a reception device that receives an input signal corresponding to the input instruction generated by the input operation section. The input instruction includes, for example, an instruction value related to a set temperature of each indoor space in which the indoor unit 3 is installed, or to a temperature of the water circulating in the water circuit 30 (temperature of water flowing out from the water-refrigerant heat exchanger 51). When the reception section 53 receives the input instruction, the relay unit 50 transmits that effect to the control device 90.

[0035] The flow rate of the water circulating by the driving of the circulation pump 34 is controlled on the basis of the rotation speed of the motor. Thus, the water is supplied to each indoor unit 3 at the same flow rate. In the example shown in Fig. 1, the circulation pump 34 is disposed in the second water pipe 12, but may be disposed in the first water pipe 11 instead or may be disposed inside the relay unit 50.(Sensors etc.)

[0036] The air conditioning device 100 includes various sensors. In the outdoor unit 2, the discharge pipe 61 is provided with 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. The suction pipe 65 is provided with a low-pressure sensor 73 that detects the pressure of the refrigerant suctioned into the compressor 21 and a suction temperature sensor 74 that detects the temperature of the refrigerant suctioned into the compressor 21.

[0037] The outdoor heat exchanger 23 is provided with a heat exchange temperature sensor 75 for detecting the temperature of the refrigerant flowing through the outdoor heat exchanger 23. In the vicinity of the suction port (not shown) of the outdoor unit 2, an outside air temperature sensor 76 that detects the temperature of outside air flowing into the outdoor unit 2, that is, an outside air temperature, is provided.

[0038] The indoor unit 3 may be provided with a room temperature sensor 77 that detects the temperature of air flowing into the indoor unit 3 (indoor temperature). The room temperature sensor 77 corresponds to detection means for detecting an indoor load. The indoor load is calculated on the basis of a difference between the temperature of room in which the indoor unit 3 is installed (indoor temperature) and the set temperature of the indoor unit 3 (target indoor temperature). Note that the room temperature sensor 77 may be provided to some of the indoor units 3a to 3c or may be provided to none of the indoor units 3a to 3c.

[0039] A first water temperature sensor 78 and a second water temperature sensor 79 are provided to the water circuit 30 located on the downstream side of the water-refrigerant heat exchanger 51. The first water temperature sensor 78 is provided to the first water pipe 11 connected to the water outlet 51d of the water-refrigerant heat exchanger 51, and detects the temperature of water flowing out from the water-refrigerant heat exchanger 51. The second water temperature sensor 79 is provided to the second water pipe 12 connected to the water inlet 51c of the water-refrigerant heat exchanger 51, and detects the temperature of water flowing into the water-refrigerant heat exchanger 51.(Control Device)

[0040] The control device 90 is an outdoor unit control device that is provided to, for example, the outdoor unit 2, and is mounted on a control board housed in an electrical component box (not shown) of the outdoor unit 2.

[0041] Fig. 2 is a block diagram showing a configuration of the control device 90. As shown in the figure, the control device 90 includes a CPU 91, a storage section 92, a communication section 93, a sensor input section 94, and a rotation speed detection section 95.

[0042] The storage section 92 is a nonvolatile memory such as a flash memory, and stores control programs or control parameters of the outdoor unit 2, detection values corresponding to detection signals from various sensors, control states of the compressor 21, the outdoor fan 29, and the like, the rotation speed of the indoor fan 32 acquired via the communication section 93, control states, of the respective indoor units 3a to 3c, including the drive modes input by the user, etc.

[0043] The communication section 93 is an interface that communicates with the indoor units 3 and the relay unit 50. The sensor input section 94 takes in detection results of the various sensors of the outdoor unit 2 and outputs them to the CPU 91. The rotation speed detection section 95 detects the rotation speed of the motor of the compressor 21 and outputs it to the CPU 91. The rotation speed detection section 95 may be configured to directly detect the rotation speed of the motor by 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 a drive current supplied to the motor. In the following description, the rotation speed of the compressor 21 means the rotation speed of the motor.

[0044] The CPU 91 is a controller that controls the operation of each section in the outdoor unit 2 including the compressor 21 by executing the programs stored in the storage section 92. The programs are installed in the control device 90, for example, via various storage media. Alternatively, the programs may be installed via the Internet or the like.

[0045] The CPU 91 takes in the detection results of the sensors of the above-mentioned outdoor unit 2 via the sensor input section 94. Further, the CPU 91 takes in the control signals transmitted from the indoor units 3 via the communication section 93. The control signals transmitted from the indoor units 3 include a required operating capacity requested by the indoor units 3 (total of the indoor loads of the indoor units 3a to 3c) and the like. The CPU 91 controls driving of the compressor 21, the outdoor fan 29, the indoor fan 32, and the circulation pump 34, for example, sets an instructed rotation speed as the rotation speed for driving those sections, on the basis of the taken-in detection results or control signals. In addition, the CPU 91 performs switching control of the four-way valve 22 on the basis of the taken-in detection results or control signals. Further, the CPU 91 performs the opening degree control of the expansion valve 24 and the opening and closing control of the on-off valve 33 on the basis of the taken-in detection results or control signals.

[0046] The CPU 91 is configured to execute one of a room temperature control mode to control the rotation speed of the compressor 21 on the basis of information related to an indoor load, and a water temperature control mode to control the rotation speed of the compressor 21 on the basis of information related to a heat load of the water circuit 30. Those room temperature control mode and water temperature control mode will be described later in detail. Here, the "indoor load" refers to the load calculated on the basis of the detection results of various sensors in the indoor units 3a to 3c. In addition, the "heat load" refers to the load calculated on the basis of the detection results of various sensors in the water circuit 30.[Basic Operation of Air Conditioning Device]

[0047] Subsequently, the basic operation of the air conditioning device 100 will be described. Hereinafter, the operation of the air conditioning device 100 during a cooling operation and a heating operation will be described.(Cooling Operation)

[0048] When the air conditioning device 100 performs a cooling operation, the compressor 21 and the circulation pump 34 are driven with the four-way valve 22 being in the state indicated by the solid lines in Fig. 1, that is, being switched to a state where the port a and the port b communicate with each other and the port c and the port d communicate with each other. When the compressor 21 is driven, the refrigerant circulates through the refrigerant circuit 20. When the circulation pump 34 is driven, water circulates through the water circuit 30. Thus, the outdoor heat exchanger 23 functions as a condenser, and the water-refrigerant heat exchanger 51 functions as an evaporator.

[0049] The rotation speed of the compressor 21 and the flow rate of the circulation pump 34 are determined in accordance with the information related to the indoor load or the information related to the heat load of the water circuit 30. Here, the case where all of the indoor units 3 cool the rooms will be described as an example.

[0050] The refrigerant compressed by the compressor 21 to have a high temperature and a high pressure is discharged from the compressor 21, flows through the discharge pipe 61 to flow into the four-way valve 22, and flows from the four-way valve 22 to the refrigerant pipe 62 to flow into the outdoor heat exchanger 23. The refrigerant that has flowed into the outdoor heat exchanger 23 exchanges heat with outside air, which has been taken into the outdoor unit 2 by the rotation of the outdoor fan 29, to be condensed.

[0051] The refrigerant that has flowed from the outdoor heat exchanger 23 flows through the outdoor unit liquid pipe 63, and is reduced in pressure when passing through the expansion valve 24. Here, the degree of opening of the expansion valve 24 is the degree of opening to obtain an evaporation pressure corresponding to an evaporation temperature in the water-refrigerant heat exchanger 51, for achieving a set temperature in the cooling operation of the room in which the indoor unit 3 is installed, more specifically, is the degree of opening at which the evaporation temperature in the water-refrigerant heat exchanger 51 and the temperature of the water flowing out from the water-refrigerant heat exchanger 51 are lower than the lowest value of the air-conditioning temperature (set temperature) set for the indoor unit 3.

[0052] The refrigerant that has passed through the expansion valve 24 and flowed through the outdoor unit liquid pipe 63 flows into the liquid refrigerant inlet / outlet 51a of the water-refrigerant heat exchanger 51. The refrigerant that has flowed into the liquid refrigerant inlet / outlet 51a passes through the refrigerant-side flow path 511 and exchanges heat with the water flowing through the water-side flow path 512 to be evaporated, and flows into the outdoor unit gas pipe 64 from the gas refrigerant inlet / outlet 51b of the water-refrigerant heat exchanger 51. The refrigerant that flows into the outdoor unit gas pipe 64 flows through the four-way valve 22, the refrigerant pipe 66, the accumulator 25, and the suction pipe 65, and is suctioned into the compressor 21 to be compressed again.

[0053] On the other hand, the water that has been cooled when flowing through the water-side flow path 512 flows out from the water outlet 51d of the water-refrigerant heat exchanger 51 to the first water pipe 11, and the water that has flowed into the first water pipe 11 flows into the indoor heat exchanger 31 of each indoor unit 3 via the first water branching pipe 111 and the on-off valve 33 in the open state, thus cooling the indoor air passing through the indoor heat exchanger 31 by the rotation of the indoor fan 32. Thus, the room in which the indoor unit 3 is installed is cooled.

[0054] The water flowing out from the indoor heat exchangers 31 of the respective indoor units 3 join in the second water pipe 12 via the second water branching pipe 121, and are suctioned into the circulation pump 34. The water suctioned into the circulation pump 34 is sent to the water inlet 51c of the water-refrigerant heat exchanger 51, passes through the water-side flow path 512 to be cooled again by the refrigerant flowing through the refrigerant-side flow path 511, and then flows out from the water outlet 51d toward the indoor units 3.(Heating Operation)

[0055] When the air conditioning device 100 performs a heating operation, the compressor 21 and the circulation pump 34 are driven with the four-way valve 22 being in the state indicated by the broken lines in Fig. 1, that is, being switched to a state where the port a and the port d communicate with each other and the port b and the port c communicate with each other. When the compressor 21 is driven, the refrigerant circulates through the refrigerant circuit 20. When the circulation pump 34 is driven, water circulates through the water circuit 30. Thus, the outdoor heat exchanger 23 functions as an evaporator, and the water-refrigerant heat exchanger 51 functions as a condenser.

[0056] The rotation speed of the compressor 21 and the flow rate of the circulation pump 34 are determined in accordance with the information related to the indoor load or the information related to the heat load of the water circuit 30. Here, the case where all of the indoor units 3 heat the rooms will be described as an example.

[0057] The refrigerant compressed by the compressor 21 to have a high temperature and a high pressure is discharged from the compressor 21, flows through the discharge pipe 61 to flow into the four-way valve 22, and flows from the four-way valve 22 to the outdoor unit gas pipe 64 to flow 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 to heat the water flowing through the water-side flow path 512. The refrigerant that has been condensed by exchanging heat with the water flowing through the water-side flow path 512 flows out from the liquid-side inlet / outlet 51a of the water-refrigerant heat exchanger 51 to the outdoor unit liquid pipe 63.

[0058] The refrigerant that has flowed to the outdoor unit liquid pipe 63 is reduced in pressure when passing through the expansion valve 24. Here, the degree of opening of the expansion valve 24 is the degree of opening at which the subcooling (degree of supercooling) of the refrigerant flowing out from the water-refrigerant heat exchanger 51 is a target subcooling, for achieving a set temperature in the heating operation of the room in which the indoor unit 3 is installed, more specifically, is the degree of opening at which the condensation temperature in the water-refrigerant heat exchanger 51 and the temperature of the water flowing out from the water-refrigerant heat exchanger 51 are higher than the highest value of the air-conditioning temperature (set temperature) set for the indoor unit 3.

[0059] The refrigerant that has passed through the expansion valve 24 and flowed through the outdoor unit liquid pipe 63 flows into the outdoor heat exchanger 23. The refrigerant that has flowed into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 29 to be evaporated. The refrigerant that has flowed out from the outdoor heat exchanger 23 flows through the refrigerant pipe 62 and is suctioned into the compressor 21 via the four-way valve 22, the refrigerant pipe 66, the accumulator 25, and the suction pipe 65 to be compressed again.

[0060] On the other hand, the water that has been heated when flowing through the water-side flow path 512 flows out from the water outlet 51d of the water-refrigerant heat exchanger 51 to the first water pipe 11, and the water that has flowed into the first water pipe 11 flows into the indoor heat exchanger 31 via the first water branching pipe 111 and the on-off valve 33 in the open state, thus heating the indoor air passing through the indoor heat exchanger 31 by the rotation of the indoor fan 32. Thus, the room in which the indoor unit 3 is installed is heated.

[0061] The water flowing out from the indoor heat exchangers 31 join in the second water pipe 12 via the second water branching pipe 121, and are suctioned into the circulation pump 34. The water suctioned into the circulation pump 34 is sent to the water inlet 51c of the water-refrigerant heat exchanger 51, passes through the water-side flow path 512 to be heated again by the refrigerant flowing through the refrigerant-side flow path 511, and then flows out from the water outlet 51d toward the indoor units 3.[Details of Control Device]

[0062] As described above, the rotation speed of the compressor 21 and the flow rate of the circulation pump 34 are determined in accordance with the information related to the indoor load or the information related to the heat load of the water circuit 30.

[0063] The information related to the indoor load includes an indoor temperature that is a detection value of the room temperature sensor 77, and a set temperature (target value of indoor temperature) of the indoor unit 3 including the room temperature sensor 77. The indoor load is calculated on the basis of a difference between those indoor temperature and set temperature.

[0064] On the other hand, the information related to the heat load of the water circuit 30 includes a water temperature that is a detection value of the first water temperature sensor 78 in the water circuit 30, a water temperature that is a detection value of the second water temperature sensor 79, and an input instruction value (temperature set value) from the user, which is received in the reception section 53 of the relay unit 50. The heat load of the water circuit 30 is calculated on the basis of those water temperatures and the input instruction value.

[0065] The control device 90 executes one of a room temperature control mode to control the rotation speed of the compressor 21 on the basis of the information related to the indoor load, and a water temperature control mode to control the rotation speed of the compressor 21 on the basis of the information related to the heat load of the water circuit 30.

[0066] The indoor unit 3 connected to the heat source module 55 constantly transmits the acquired information related to the indoor load to the control device 90.

[0067] It is determined which of the room temperature control mode and the water temperature control mode is to be executed in accordance with the specification, model, or the like of the indoor unit 3 that has received an operation instruction. For example, if each indoor unit 3 that has received an operation instruction includes the room temperature sensor 77, the control device 90 executes the room temperature control mode to individually control the indoor spaces, in which the respective indoor units 3 are installed, to have a set temperature that has been set for the indoor units 3. On the other hand, if any one of the indoor units 3 includes no room temperature sensor 77, the control device 90 executes the water temperature control mode to control in common the indoor spaces, in which the respective indoor units 3 are installed, to have a set temperature corresponding to the input instruction from the user, which has been received in the reception section 53.

[0068] Fig. 3 is a flowchart showing an example of a control mode determination procedure for the compressor 21, which is executed in the control device 90.

[0069] When the air conditioning device 100 (heat source module 55) is activated, the control device 90 identifies an indoor unit 3 that has received an operation instruction (ST101). Subsequently, the control device 90 determines whether or not information related to an indoor load has been received from all the indoor units 3 identified as having received an operation instruction (ST102).

[0070] In this embodiment, if the information related to the indoor load has been received from all the indoor units 3 identified as having received an operation instruction, the control device 90 executes the room temperature control mode (Yes in ST102), and if reception of the information related to the indoor load fails to be confirmed from all the indoor units 3 identified as having received an operation instruction, the control device 90 executes the water temperature control mode (No in ST102).

[0071] In this embodiment, if the room temperature sensor 77 is provided to all the indoor units 3 connected to the relay unit 50, or if the room temperature sensor 77 is provided to all the indoor units 3 that start the operation, the information related to the indoor load, which is transmitted from each indoor unit 3, can be received, and thus the room temperature control mode is executed on the basis of the information related to the indoor load, which is transmitted from each indoor unit 3.

[0072] On the other hand, if the room temperature sensor 77 is not provided to at least one of the indoor units 3 connected to the relay unit 50, or if the room temperature sensor 77 is not provided to at least one of the indoor units 3 that start the operation, the reception of the indoor information fails to be confirmed for all of those indoor units 3, and thus the water temperature control mode is executed. In this case, the water temperature control mode is executed on the basis of an input instruction received in the reception section 53 of the relay unit 50. Note that if an input instruction from the user is received via the reception section 53, the control device 90 may execute the water temperature control mode even when the room temperature control mode is being executed.

[0073] In such a manner, even if an indoor unit without the room temperature sensor 77 is included among all the indoor units 3 connected to the relay unit 50, if the indoor units 3 that have received an operation instruction all include the room temperature sensors 77, the room temperature control mode is selected. According to this embodiment, each time the air conditioning device 100 starts to operate, the control mode is determined on the basis of whether or not the information related to the indoor load has been received from all the indoor units 3 that have received an operation instruction, so that a suitable control mode can be automatically selected without considering the presence / absence of the room temperature sensor 77 of the indoor unit 3 connected to the relay unit 50. In addition, the determination processing of ST102 is repeated at a predetermined period, so that switching from the room temperature control mode to the water temperature control mode can be automatically performed even if an event that makes it impossible to transmit the information related to the indoor load occurs due to a failure of the room temperature sensor 77 or the like in some of the indoor units 3 during the execution of the room temperature control mode.(Room Temperature Control Mode)

[0074] In the room temperature control mode, the control device 90 calculates the indoor load on the basis of the difference between the indoor temperature and the set temperature, using the set temperature of the indoor temperature stored in advance (ST103).

[0075] The set temperature of the indoor temperature is input by the user via an operation panel (operation remote controller) installed on each indoor unit 3. The indoor temperature is a detection value of the room temperature sensor 77 installed on each indoor unit 3. The input set temperature and the detected indoor temperature are stored in the storage section 92 of the control device 90 for each indoor unit 3. The control device 90 acquires the set temperature and the indoor temperature at a predetermined period, and updates the set temperature and the indoor temperature stored in the storage section 92 to the latest set temperature and detected temperature.

[0076] The control device 90 calculates an indoor load that is a difference between the set temperature and the indoor temperature in each indoor unit 3, and executes the room temperature control mode to control the rotation speed of the compressor 21 on the basis of the total value of the indoor loads of the indoor units 3 (ST104).

[0077] The control device 90 controls the rotation speed of the compressor 21 in accordance with the operating capacity (total value of the indoor loads of the respective indoor units 3) requested from the indoor units 3 during the execution of the room temperature control mode. Therefore, after all the indoor units 3a to 3c start to operate, for example, when the indoor unit 3a stops the operation due to thermo-off, the control device 90 controls the rotation speed of the compressor 21 in accordance with the indoor load associated with the decrease in the number of indoor units 3 being in operation. When the rotation speed of the compressor 21 is determined, a table or the like that is determined in advance in accordance with the magnitude of the indoor load may be referred to. The operation and its shutdown of the indoor unit 3 are switched by the opening and closing operation of the on-off valve 33 provided to correspond to each indoor unit 3.(Water Temperature Control Mode)

[0078] On the other hand, in the water temperature control mode, the control device 90 stores a target temperature of the water temperature of the water circuit 30 and calculates a heat load of the water circuit 30 on the basis of a difference between the water temperature of the water circuit 30 and the target temperature (ST105).

[0079] The target temperature of the water temperature of the water circuit 30 is a target value of the temperature of the water flowing out from the water-refrigerant heat exchanger 51 and is set on the basis of the input instruction from the user, which has been received by the reception section 53 of the relay unit 50. The water temperature of the water circuit 30 is a detection value of the first water temperature sensor 78 that detects the temperature of the water flowing out from the water-refrigerant heat exchanger 51. The set target temperature and the detected water temperature of the water circuit 30 are stored in the storage section 92 of the control device 90. The control device 90 acquires the target temperature and the water temperature of the water circuit 30 at a predetermined period, and updates the target temperature and the water temperature stored in the storage section 92 to the latest target temperature and water temperature, respectively. Note that the method of calculating the heat load of the water circuit 30 may be an estimation based on the difference between the detection value of the first water temperature sensor 78 and the detection value of the second water temperature sensor 79. Specifically, it is estimated that as the difference becomes larger, the heat load of the water circuit 30 becomes higher.

[0080] The control device 90 executes the water temperature control mode to calculate the heat load of the water circuit 30 on the basis of the difference between the water temperature of the water circuit 30 and the target temperature and to control the rotation speed of the compressor 21 on the basis of that heat load (ST106).

[0081] The control device 90 controls the rotation speed of the compressor 21 in accordance with the calculated heat load of the water circuit 30 during the execution of the water temperature control mode. Therefore, after all the indoor units 3a to 3c start to operate, for example, when the indoor unit 3a stops the operation due to thermo-off, the control device 90 controls the rotation speed of the compressor 21 in accordance with the heat load of the water circuit 30 associated with the decrease in the number of indoor units 3 being in operation. When the rotation speed of the compressor 21 is determined, a table or the like that is determined in advance in accordance with the magnitude of the heat load of the water circuit 30 may be referred to. The operation and its shutdown of the indoor unit 3 are switched by the opening and closing operation of the on-off valve 33 provided to correspond to each indoor unit 3.

[0082] As described above, according to this embodiment, the control device 90 executes one of the room temperature control mode to control the rotation speed of the compressor 21 on the basis of the information related to the indoor load, and the water temperature control mode to control the rotation speed of the compressor 21 on the basis of the information related to the heat load of the water circuit 30, which makes it possible to suitably control the rotation speed of the compressor 21 in accordance with the specification or model of the indoor units 3 connected to the relay unit 50. In addition, even if an indoor unit with the room temperature sensor 77 and an indoor unit without the room temperature sensor 77 are mixed, an indoor space in which each indoor unit is installed can be controlled to have a desired air-conditioning temperature.

[0083] Hereinabove, the embodiment of the present invention has been described, but the present invention is not limited to the embodiment described above and, of course, can be variously modified.

[0084] For example, in the embodiment described above, the number of relay units 50 connected to the outdoor unit 2 is set to one, but it may be two or more. In addition, the number of indoor units 3 connected to the relay unit is set to three, but it is not limited thereto. At least one indoor unit only needs to be connected.

[0085] Further, in the embodiment described above, the air conditioning device including the indoor unit 3 (first indoor unit) including the water heat exchanger as an indoor heat exchanger has been described as an example, but the present invention is not limited thereto and is also applicable to an air conditioning device further including, in addition to the indoor unit 3, an indoor unit (second indoor unit) including a refrigerant heat exchanger into which and from which the refrigerant flowing through the primary refrigerant circuit 10 flows.Reference Signs List

[0086] 2outdoor unit 3 (3a, 3b, 3c)indoor unit 20primary refrigerant circuit 21compressor 22four-way valve 23outdoor heat exchanger 24expansion valve 30water circuit (secondary refrigerant circuit) 31indoor heat exchanger 32indoor fan 34circulation pump 33on-off valve 50relay unit 51water-refrigerant heat exchanger 53reception section 55heat source module 78first water temperature sensor 79second water temperature sensor 90control device 100air conditioning device

Claims

1. An air conditioning device, comprising: a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; a secondary refrigerant circuit, through which a secondary refrigerant circulates, the secondary refrigerant circuit including at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a circulation pump; and a control device that controls the compressor, wherein the control device executes one of a room temperature control mode to control a rotation speed of the compressor on a basis of information related to an indoor load and a water temperature control mode to control the rotation speed of the compressor on a basis of information related to a heat load of the secondary refrigerant circuit.

2. The air conditioning device according to claim 1, wherein the indoor unit further includes a room temperature sensor that detects an indoor temperature, and the control device stores a set temperature of the indoor temperature and calculates the indoor load on a basis of a difference between the indoor temperature and the set temperature.

3. The air conditioning device according to claim 1, wherein the secondary refrigerant circuit further includes a water temperature sensor that is provided on a downstream side of the water-refrigerant heat exchanger and detects a temperature of the secondary refrigerant, and the control device stores a target temperature of the secondary refrigerant and calculates the heat load on a basis of a difference between the temperature of the secondary refrigerant and the target temperature.

4. The air conditioning device according to claim 1, wherein the relay unit further includes a reception section that receives an input instruction of a user, and the control device executes the water temperature control mode, when the input instruction is received via the reception section.

5. The air conditioning device according to claim 1, wherein the secondary refrigerant circuit includes a plurality of the indoor units, and the control device executes the room temperature control mode by receiving the information related to the indoor load, the information being transmitted from the indoor units, and executes, when there is one or more of the indoor units, for which transmission of the information related to the indoor load fails to be confirmed, the water temperature control mode to control the rotation speed of the compressor on a basis of the information related to the heat load of the secondary refrigerant circuit.

6. A heat source module, comprising: a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; and a control device that controls the compressor, wherein the control device executes one of a room temperature control mode to control a rotation speed of the compressor on a basis of information related to an indoor load, the information being transmitted from at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a water temperature control mode to control the rotation speed of the compressor on a basis of information related to a heat load of the secondary refrigerant circuit.

7. An indoor unit that is connected to the heat source module according to claim 6 and includes a water heat exchanger connected to the water-refrigerant heat exchanger, the indoor unit comprising means for detecting the indoor load for causing the control device to execute the room temperature control mode to control the rotation speed of the compressor on a basis of the information related to the indoor load.

8. A control method for an air conditioning device that includes a primary refrigerant circuit, through which a primary refrigerant circulates, the primary refrigerant circuit including an outdoor unit including a compressor and an outdoor heat exchanger, and at least one relay unit including a water-refrigerant heat exchanger that exchanges heat between a refrigerant and water and connected to the outdoor unit; and a secondary refrigerant circuit, through which a secondary refrigerant circulates, the secondary refrigerant circuit including at least one indoor unit connected to the water-refrigerant heat exchanger and including a water heat exchanger, and a circulation pump, the control method comprising: executing, when the outdoor unit receives information related to an indoor load, the information being transmitted from the indoor unit, a room temperature control mode to control a rotation speed of the compressor on a basis of the information related to the indoor load; and executing, when transmission of the information related to the indoor load from the indoor unit fails to be confirmed, a water temperature control mode to control the rotation speed of the compressor on a basis of information related to a heat load of the secondary refrigerant circuit.

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