JPWO2014061130A1 - Air conditioner - Google Patents

Abstract

The air conditioner (1) has a refrigerant circuit (10) configured by connecting a plurality of indoor units (4a, 4b) to the outdoor unit (2), and includes a capacity control means (81) And a target refrigerant temperature variable means (84). The capacity control means (81) is a means for controlling the air conditioning capacity of the outdoor unit (2) so that the evaporation temperature or condensation temperature of the refrigerant in the refrigerant circuit (10) becomes the target evaporation temperature or the target condensation temperature. The target refrigerant temperature variable means 884) performs slow variable control for changing the target evaporation temperature or the target condensation temperature according to the temperature difference between the room temperature and the set temperature, and the temperature difference exceeds the threshold temperature difference, and When the number of operating indoor units (4a, 4b) increases, rapid variable control is performed to forcibly change the target evaporation temperature or the target condensation temperature to the rapid tracking evaporation temperature or the rapid tracking condensation temperature.

Description

  The present invention relates to an air conditioner, and more particularly, to an air conditioner including a refrigerant circuit configured by connecting a plurality of indoor units to an outdoor unit.

  Conventionally, there is an air conditioner provided with a refrigerant circuit configured by connecting a plurality of indoor units to an outdoor unit. As this air conditioner, capacity control for controlling the air conditioning capacity of the outdoor unit (specifically, the operating capacity of the compressor) so that the evaporation temperature or condensation temperature of the refrigerant in the refrigerant circuit becomes the target evaporation temperature or the target condensation temperature. Some have means. And as an example of the air conditioning apparatus which has a capability control means, there exists what changed the target evaporation temperature or the target condensation temperature as shown to patent document 1 (Unexamined-Japanese-Patent No. 2002-147823). Here, the target evaporation temperature or the target condensation temperature is varied according to the air conditioning load characteristics of the building.

By changing the target evaporation temperature or the target condensation temperature as described above, excessive air conditioning capacity of the outdoor unit is suppressed, and the repetition frequency of operation / stop of the indoor unit and compressor is reduced, thereby improving energy saving. Can be made.
However, on the other hand, for example, when the outdoor unit requires a large air conditioning capacity due to an increase in the number of indoor units operated, the air conditioning capacity of the outdoor unit tends to be suppressed. There is a tendency that the time until the indoor temperature of the space reaches the set temperature, which is the target value, tends to be long, and sufficient control followability may not be obtained.
As described above, in the air conditioner, by changing the target evaporation temperature or the target condensation temperature, an excessive air conditioning capability of the outdoor unit is suppressed to improve energy savings, and the number of indoor units operated increases. Even when a large air conditioning capacity is required for the outdoor unit, it is desired to be able to obtain sufficient control followability.

  An object of the present invention is to improve energy saving by varying a target evaporation temperature or a target condensation temperature in an air conditioner having a refrigerant circuit configured by connecting a plurality of indoor units to an outdoor unit. An object of the present invention is to provide sufficient control followability even when the number of operating indoor units increases.

  An air conditioner according to a first aspect is an air conditioner including a refrigerant circuit configured by connecting a plurality of indoor units to an outdoor unit, and includes an ability control unit and a target refrigerant temperature variable unit. doing. The capacity control means is a means for controlling the air conditioning capacity of the outdoor unit so that the evaporation temperature or condensation temperature of the refrigerant in the refrigerant circuit becomes the target evaporation temperature or the target condensation temperature. The target refrigerant temperature variable means performs slow variable control for changing the target evaporation temperature or the target condensation temperature according to the temperature difference between the indoor temperature of the air-conditioned space targeted by the indoor unit and the set temperature that is the target value of the indoor temperature. When the temperature difference exceeds the threshold temperature difference and the number of indoor units operated increases, the target evaporation temperature or the target condensation temperature is forcibly changed to the rapid tracking evaporation temperature or the rapid tracking condensation temperature. Perform variable control. Here, “evaporation temperature” means a state quantity equivalent to the evaporation pressure in the refrigerant circuit, and “condensation temperature” means a state quantity equivalent to the condensation pressure in the refrigerant circuit. That is, the evaporating pressure and evaporating temperature, the target evaporating pressure and the target evaporating temperature, the condensing pressure and the condensing temperature, and the target condensing pressure and the target condensing temperature mean substantially the same state quantity although the wording itself is different. . Further, “when the number of indoor units operated increases” includes not only the case where the operation of the stopped indoor unit is started, but also the case where the indoor unit that is in the thermo-off state is in the thermo-on state.

Here, first, since the variable speed control is performed by the target refrigerant temperature varying means, the temperature difference between the room temperature and the set temperature exceeds the threshold temperature difference, and the number of indoor units operated increases. Except for the above, the target evaporation temperature or the target condensation temperature is changed gradually. For this reason, the excess of the air-conditioning capability of an outdoor unit can be suppressed fundamentally. In addition, here, when the temperature difference between the room temperature and the set temperature exceeds the threshold temperature difference and the number of indoor units operating increases, that is, the number of indoor units operating increases, so that the outdoor unit has a large air conditioning. When capability is required, the target evaporation temperature or the target condensation temperature is forcibly changed to the rapid follow-up evaporation temperature or the rapid follow-up condensation temperature by performing rapid variable control.
Thereby, here, energy efficiency can be improved by varying the target evaporation temperature or the target condensation temperature, and sufficient control follow-up can be obtained even when the number of indoor units operating is increased.

An air conditioner according to a second aspect is the air conditioner according to the first aspect, wherein a maximum value of a temperature difference between a room temperature and a set temperature among the operating indoor units is determined by a target evaporation temperature or a target condensation. Used as a condition for temperature change.
Here, the target evaporation temperature or the target condensing temperature is changed according to the indoor unit that requires the greatest air conditioning capability.
Thereby, here, in either the slow variable control or the rapid variable control, the target evaporation temperature or the target condensation temperature can be quickly changed to improve the control followability.

An air conditioner according to a third aspect is the air conditioner according to the first or second aspect, wherein the target refrigerant temperature varying means determines whether or not the slow variable control is necessary every time the first waiting time elapses. Whenever the second waiting time shorter than the first waiting time elapses, the necessity of the rapid variable control is determined.
Here, rapid variable control can be performed more frequently than slow variable control. For this reason, it is possible to quickly detect that the rapid variable control is necessary.
Thereby, the control followability of rapid variable control can be improved here.

  The air conditioner according to a fourth aspect is the air conditioner according to any one of the first to third aspects, wherein the rapid variable control includes powerful variable control and quick variable control. Powerful variable control is the minimum evaporation temperature or the maximum condensation temperature that exceeds the maximum capacity evaporation temperature or the maximum capacity condensation temperature when the rapid tracking evaporation temperature or the rapid tracking condensation temperature is equivalent to the case where the air conditioning capacity of the outdoor unit is 100%. The control is changed to The quick variable control is a control in which the rapid tracking evaporation temperature or the rapid tracking condensation temperature is changed to the maximum capacity evaporation temperature or the maximum capacity condensation temperature.

Here, the rapid variable control has two controls with different levels of control followability, namely, a powerful variable control and a quick variable control. In the powerful variable control, since the minimum evaporation temperature or the maximum condensation temperature exceeding the maximum capacity evaporation temperature or the maximum capacity condensation temperature is changed, the control followability is further improved as compared with the quick variable control.
Thereby, here, the degree of control followability can be changed in the rapid variable control.

It is a schematic block diagram of the air conditioning apparatus concerning one Embodiment of this invention. It is a control block diagram of an air conditioning apparatus. It is a figure which shows the various modes regarding the target evaporation temperature and target condensation temperature which can be set. It is a flowchart which shows correction | amendment control of the target evaporation temperature in slow speed variable mode and rapid variable mode (quick mode, powerful mode). It is a flowchart which shows correction | amendment control of the target condensing temperature in slow speed variable mode and rapid variable mode (quick mode, powerful mode). It is a figure which shows the time-dependent change from the start of the air_conditionaing | cooling operation of the target evaporation temperature in the target refrigerant temperature fixed mode and the target refrigerant temperature variable mode (slow variable mode, quick mode, powerful mode). It is a figure which shows the time-dependent change of the target evaporation temperature and room temperature in the slow variable mode, quick mode, and powerful mode when the number of indoor units in operation increases during cooling operation. It is a figure which shows the time-dependent change from the start of the heating operation of the target condensing temperature, room temperature, and efficiency in target refrigerant temperature fixed mode and target refrigerant temperature variable mode (slow variable mode, quick mode, powerful mode). It is a figure which shows the time-dependent change of the target condensing temperature and room temperature in the slow variable mode, quick mode, and powerful mode when the number of indoor units operated at the time of heating operation increases. It is a flowchart which shows the correction | amendment control of the target evaporation temperature in the slow variable mode and the quick variable mode (quick mode, powerful mode) concerning the modification 1. It is a flowchart which shows the correction | amendment control of the target condensing temperature in the slow variable mode and the quick variable mode (quick mode, powerful mode) concerning the modification 1.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an air conditioner according to the present invention will be described with reference to the drawings. In addition, the specific structure of embodiment of the air conditioning apparatus concerning this invention is not restricted to the following embodiment and its modification, It can change in the range which does not deviate from the summary of invention.

(1) Basic Configuration of Air Conditioner FIG. 1 is a schematic configuration diagram of an air conditioner 1 according to an embodiment of the present invention. The air conditioning apparatus 1 is an apparatus used for air conditioning indoors such as buildings by performing a vapor compression refrigeration cycle operation. The air conditioner 1 is mainly configured by connecting an outdoor unit 2 and a plurality (here, two) of indoor units 4a and 4b. Here, the outdoor unit 2 and the plurality of indoor units 4 a and 4 b are connected via a liquid refrigerant communication tube 6 and a gas refrigerant communication tube 7. That is, the vapor compression refrigerant circuit 10 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the plurality of indoor units 4 a and 4 b via the refrigerant communication pipes 6 and 7.

<Indoor unit>
The indoor units 4a and 4b are installed indoors. The indoor units 4 a and 4 b are connected to the outdoor unit 2 via the refrigerant communication pipes 6 and 7 and constitute a part of the refrigerant circuit 10.
Next, the configuration of the indoor units 4a and 4b will be described. Since the indoor unit 4b has the same configuration as the indoor unit 4a, only the configuration of the indoor unit 4a will be described here, and the configuration of the indoor unit 4b is indicated by the suffix a indicating each part of the indoor unit 4a. Instead, a subscript “b” is attached and description of each part is omitted.
The indoor unit 4a mainly has an indoor refrigerant circuit 10a (in the indoor unit 4b, the indoor refrigerant circuit 10b) that constitutes a part of the refrigerant circuit 10. The indoor refrigerant circuit 10a mainly has an indoor expansion valve 41a and an indoor heat exchanger 42a.

The indoor expansion valve 41a is a valve that adjusts the flow rate of the refrigerant by reducing the pressure of the refrigerant flowing through the indoor refrigerant circuit 10a. The indoor expansion valve 41a is an electric expansion valve connected to the liquid side of the indoor heat exchanger 42a.
The indoor heat exchanger 42a is composed of, for example, a cross fin type fin-and-tube heat exchanger. An indoor fan 43a for sending indoor air to the indoor heat exchanger 42a is provided in the vicinity of the indoor heat exchanger 42a. By blowing indoor air to the indoor heat exchanger 42a by the indoor fan 43a, the indoor heat exchanger 42a performs heat exchange between the refrigerant and the indoor air. The indoor fan 43a is rotationally driven by an indoor fan motor 44a. Thereby, the indoor heat exchanger 42a functions as a refrigerant radiator or a refrigerant evaporator.

  Various sensors are provided in the indoor unit 4a. On the liquid side of the indoor heat exchanger 42a, a liquid side temperature sensor 45a that detects the temperature Trla of the refrigerant in the liquid state or the gas-liquid two-phase state is provided. On the gas side of the indoor heat exchanger 42a, a gas side temperature sensor 46a for detecting the temperature Trga of the refrigerant in the gas state is provided. On the indoor air inlet side of the indoor unit 4a, an indoor temperature sensor 47a for detecting the temperature of indoor air in the air-conditioned space targeted by the indoor unit 4a (that is, the indoor temperature Tra) is provided. Moreover, the indoor unit 4a has the indoor side control part 48a which controls operation | movement of each part which comprises the indoor unit 4a. And the indoor side control part 48a has a microcomputer, memory, etc. provided in order to control the indoor unit 4a, and controls between the remote controllers 49a for operating the indoor unit 4a separately. Signals and the like can be exchanged, and control signals and the like can be exchanged with the outdoor unit 2. The remote controller 49a is a device that allows the user to make various settings related to the air conditioning operation and run / stop commands.

<Outdoor unit>
The outdoor unit 2 is installed outdoors. The outdoor unit 2 is connected to the indoor units 4 a and 4 b via the refrigerant communication pipes 6 and 7 and constitutes a part of the refrigerant circuit 10.
Next, the configuration of the outdoor unit 2 will be described.
The outdoor unit 2 mainly has an outdoor refrigerant circuit 10 c that constitutes a part of the refrigerant circuit 10. The outdoor refrigerant circuit 10c mainly includes a compressor 21, a switching mechanism 22, an outdoor heat exchanger 23, and an outdoor expansion valve 24.
The compressor 21 is a hermetic compressor in which a compression element (not shown) and a compressor motor 20 that rotationally drives the compression element are accommodated in a casing. The compressor motor 20 is supplied with electric power via an inverter device (not shown), and the operating capacity can be varied by changing the frequency (that is, the rotation speed) of the inverter device. ing.

  The switching mechanism 22 is a four-way switching valve for switching the direction of refrigerant flow. During the cooling operation as one of the air conditioning operations, the switching mechanism 22 uses the outdoor heat exchanger 23 as a radiator for the refrigerant compressed in the compressor 21 and the indoor heat exchangers 42a and 42b as the outdoor heat exchanger 23. In order to function as an evaporator for the refrigerant that has dissipated heat, the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 23 are connected, and the suction side of the compressor 21 and the gas refrigerant communication pipe 7 are connected ( In the heat dissipation switching state (see the solid line of the switching mechanism 22 in FIG. 1), during the heating operation as one of the air conditioning operations, the indoor heat exchangers 42a and 42b are used as the radiator radiators compressed in the compressor 21, and In order for the outdoor heat exchanger 23 to function as an evaporator for the refrigerant that has dissipated heat in the indoor heat exchangers 42a and 42b, the discharge side of the compressor 21 and the gas refrigerant communication pipe 7 are connected and the compressor 21 It is possible to connect the gas side of the inlet side and the outdoor heat exchanger 23 (evaporator switching state, see dashed switching mechanism 22 in FIG. 1). The switching mechanism 22 may be configured to perform the same function by combining a three-way valve, an electromagnetic valve, or the like instead of the four-way switching valve.

The outdoor heat exchanger 23 includes, for example, a cross fin type fin-and-tube heat exchanger. An outdoor fan 25 for sending outdoor air to the outdoor heat exchanger 23 is provided in the vicinity of the outdoor heat exchanger 23. By blowing outdoor air to the outdoor heat exchanger 23 by the outdoor fan 25, the outdoor heat exchanger 23 performs heat exchange between the refrigerant and the outdoor air. The outdoor fan 25 is rotationally driven by an outdoor fan motor 26. Accordingly, the outdoor heat exchanger 23 functions as a refrigerant radiator or a refrigerant evaporator.
The outdoor expansion valve 24 is a valve that depressurizes the refrigerant flowing through the outdoor refrigerant circuit 10c. The outdoor expansion valve 24 is an electric expansion valve connected to the liquid side of the outdoor heat exchanger 23.
The outdoor unit 2 is provided with various sensors. The outdoor unit 2 includes a suction pressure sensor 31 that detects the suction pressure Ps of the compressor 21, a discharge pressure sensor 32 that detects the discharge pressure Pd of the compressor 21, and a suction temperature that detects the suction temperature Ts of the compressor 21. A sensor 33 and a discharge temperature sensor 34 for detecting the discharge temperature Td of the compressor 21 are provided. The outdoor heat exchanger 23 is provided with an outdoor heat exchange temperature sensor 35 that detects the temperature Tol1 of the refrigerant in the gas-liquid two-phase state. On the liquid side of the outdoor heat exchanger 23, a liquid side temperature sensor 36 for detecting the temperature Tol2 of the refrigerant in the liquid state or the gas-liquid two-phase state is provided. An outdoor temperature sensor 37 that detects the temperature of the outdoor air in the external space in which the outdoor unit 2 is disposed (that is, the outdoor temperature Ta) is provided on the outdoor air inlet side of the outdoor unit 2. The outdoor unit 2 also has an outdoor control unit 38 that controls the operation of each part constituting the outdoor unit 2. The outdoor control unit 38 includes a microcomputer provided for controlling the outdoor unit 2, an inverter device that controls the memory and the compressor motor 20, and the like, and is provided on the indoor side of the indoor units 4 a and 4 b. Control signals and the like can be exchanged with the control units 48a and 48b.

<Refrigerant communication pipe>
The refrigerant communication pipes 6 and 7 are refrigerant pipes that are constructed on the site when the air conditioner 1 is installed, and have various lengths and pipe diameters depending on the installation conditions of the outdoor unit 2 and the indoor units 4a and 4b. Are used.

<Control unit>
The remote controllers 49a and 49b for individually operating the indoor units 4a and 4b, the indoor side control units 48a and 48b of the indoor units 4a and 4b, and the outdoor side control unit 38 of the outdoor unit 2 are shown in FIG. Thus, the control part 8 which performs operation control of the whole air conditioning apparatus 1 is comprised. As shown in FIG. 2, the control unit 8 is connected so as to receive detection signals from various sensors 31 to 37, 45a, 45b, 46a, 46b, 47a, 47b, and the like. Then, the control unit 8 controls the various devices and valves 20, 22, 24, 26, 41a, 41b, 44a, and 44b based on these detection signals and the like, thereby performing the air conditioning operation (cooling operation and heating operation). It is configured to be able to do. Here, the control unit 8 mainly includes a capacity control unit 81, an indoor control unit 82, a target refrigerant temperature mode setting unit 83, and a target refrigerant temperature variable unit 84. The capacity control means 81 is a means for controlling the air conditioning capacity of the outdoor unit 2 so that the refrigerant evaporation temperature Te or the condensation temperature Tc in the refrigerant circuit 10 becomes the target evaporation temperature Tes or the target condensation temperature Tcs. The indoor control means 82 is configured so that the indoor temperatures Tra and Trb of the air-conditioned spaces targeted by the indoor units 4a and 4b become the set temperatures Tras and Trbs that are target values of the indoor temperatures Tra and Trb. It is a means for controlling the devices 4a and 4b and the valves 41a, 41b, 44a and 44b. The target refrigerant temperature mode setting means 83 is a means for setting a mode related to the target evaporation temperature Tes and the target condensation temperature Tcs, such as setting whether to change or fix the target evaporation temperature Tes or the target condensation temperature Tcs. It is. The target refrigerant temperature varying means 84 is a means for changing or fixing the target evaporation temperature Tes and the target condensation temperature Tcs according to the mode set by the target refrigerant temperature mode setting means 83. Here, FIG. 2 is a control block diagram of the air conditioner 1.

  As described above, the air conditioner 1 has the refrigerant circuit 10 configured by connecting a plurality (here, two) of indoor units 4 a and 4 b to the outdoor unit 2. In the air conditioner 1, the following air conditioning operation and control are performed by the control unit 8.

(2) Basic Operation of Air Conditioner Next, the basic operation of the air conditioning operation (cooling operation and heating operation) of the air conditioner 1 will be described with reference to FIG.

<Cooling operation>
When a cooling operation command is issued from the remote controllers 49a and 49b, the switching mechanism 22 is switched to the heat dissipation operation state (the state indicated by the solid line of the switching mechanism 22 in FIG. 1), and the compressor 21, the outdoor fan 25, and The indoor fans 43a and 43b are activated.
Then, the low-pressure gas refrigerant in the refrigerant circuit 10 is sucked into the compressor 21 and compressed to become a high-pressure gas refrigerant. The high-pressure gas refrigerant is sent to the outdoor heat exchanger 23 via the switching mechanism 22. The high-pressure gas refrigerant sent to the outdoor heat exchanger 23 is condensed by being cooled by exchanging heat with outdoor air supplied by the outdoor fan 25 in the outdoor heat exchanger 23 functioning as a refrigerant radiator. Thus, a high-pressure liquid refrigerant is obtained. The high-pressure liquid refrigerant is sent from the outdoor unit 2 to the indoor units 4a and 4b via the outdoor expansion valve 24 and the liquid refrigerant communication pipe 6.

The high-pressure liquid refrigerant sent to the indoor units 4a and 4b is depressurized by the indoor expansion valves 41a and 41b, and becomes a low-pressure gas-liquid two-phase refrigerant. This low-pressure gas-liquid two-phase refrigerant is sent to the indoor heat exchangers 42a and 42b. The low-pressure gas-liquid two-phase refrigerant sent to the indoor heat exchangers 42a and 42b is combined with the indoor air supplied by the indoor fans 43a and 43b in the indoor heat exchangers 42a and 42b that function as refrigerant evaporators. By evaporating by heating through heat exchange, it becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant is sent from the indoor units 4 a and 4 b to the outdoor unit 2 via the gas refrigerant communication pipe 7.
The low-pressure gas refrigerant sent to the outdoor unit 2 is again sucked into the compressor 21 via the switching mechanism 22.

<Heating operation>
When a heating operation command is issued from the remote controllers 49a, 49b, the switching mechanism 22 is switched to the evaporation operation state (the state indicated by the broken line of the switching mechanism 22 in FIG. 1), and the compressor 21, the outdoor fan 25, and The indoor fans 43a and 43b are activated.
Then, the low-pressure gas refrigerant in the refrigerant circuit 10 is sucked into the compressor 21 and compressed to become a high-pressure gas refrigerant. The high-pressure gas refrigerant is sent from the outdoor unit 2 to the indoor units 4a and 4b via the switching mechanism 22 and the gas refrigerant communication pipe 7.
The high-pressure gas refrigerant sent to the indoor units 4a and 4b is sent to the indoor heat exchangers 42a and 42b. The high-pressure gas refrigerant sent to the indoor heat exchangers 42a and 42b exchanges heat with the indoor air supplied by the indoor fans 43a and 43b in the indoor heat exchangers 42a and 42b functioning as a refrigerant radiator. It is condensed by being cooled to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is depressurized by the indoor expansion valves 41a and 41b. The refrigerant decompressed by the indoor expansion valves 41 a and 41 b is sent from the indoor units 4 a and 4 b to the outdoor unit 2 via the gas refrigerant communication pipe 7.

  The refrigerant sent to the outdoor unit 2 is sent to the outdoor expansion valve 24 and is decompressed by the outdoor expansion valve 24 to become a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant is sent to the outdoor heat exchanger 23. The low-pressure gas-liquid two-phase refrigerant sent to the outdoor heat exchanger 23 is heated by exchanging heat with outdoor air supplied by the outdoor fan 25 in the outdoor heat exchanger 23 functioning as an evaporator of the refrigerant. As a result, it evaporates and becomes a low-pressure gas refrigerant. The low-pressure gas refrigerant is again sucked into the compressor 21 via the switching mechanism 22.

<Basic control>
In the air conditioning operation (cooling operation and heating operation), the air conditioning capability of the outdoor unit 2 is controlled so that the refrigerant evaporation temperature Te or the condensation temperature Tc in the refrigerant circuit 10 becomes the target evaporation temperature Tes or the target condensation temperature Tcs. The Further, the devices and valves 41a, 41b, 44a of the indoor units 4a, 4b are set so that the indoor temperatures Tra, Trb in the indoor units 4a, 4b become the set temperatures Tras, Trbs of the indoor temperatures in the indoor units 4a, 4b. , 44b are controlled. Note that the setting of the indoor temperature setting temperatures Tras and Trbs in each of the indoor units 4a and 4b is performed by the remote controllers 49a and 49b. The outdoor unit 2 is controlled by the capacity control means 81 configured by the outdoor control unit 38 of the control unit 8, and the indoor units 4 a and 4 b are controlled by the indoor side control units 48 a and 48 b of the control unit 8. This is performed by the indoor control means 82 constituted by

-During cooling operation-
When the air conditioning operation is the cooling operation, the indoor control means 82 of the control unit 8 is configured so that the superheat degrees SHra and SHrb of the refrigerant at the outlets of the indoor heat exchangers 42a and 42b become the target superheat degrees SHras and SHrbs. The opening degree of each indoor expansion valve 41a, 41b is controlled (hereinafter, this control is referred to as “superheat degree control by the indoor expansion valve”). Here, the superheat degrees SHra and SHrb are the suction pressure Ps detected by the suction pressure sensor 31 and the temperature Trga of the refrigerant on the gas side of the indoor heat exchangers 42a and 42b detected by the gas side temperature sensors 46a and 46b. , Trgb. More specifically, first, the suction pressure Ps is converted into the refrigerant saturation temperature to obtain the evaporation temperature Te, which is a state quantity equivalent to the evaporation pressure Pe in the refrigerant circuit 10. Here, the evaporation pressure Pe is a low-pressure refrigerant that flows from the outlets of the indoor expansion valves 41a and 41b to the suction side of the compressor 21 via the indoor heat exchangers 42a and 42b during the cooling operation. Is a representative pressure. And superheat degree SHra and SHrb are obtained by subtracting the evaporation temperature Te from the temperature Trga and Trgb of the gas side refrigerant | coolant of each indoor heat exchanger 42a and 42b.

When the air conditioning operation is the cooling operation, the capacity control means 81 of the control unit 8 operates the compressor 21 so that the evaporation temperature Te corresponding to the evaporation pressure Pe in the refrigerant circuit 10 approaches the target evaporation temperature Tes. The capacity is controlled (hereinafter, this control is referred to as “evaporation temperature control by the compressor”). Here, the operation capacity of the compressor 21 is controlled by changing the frequency of the compressor motor 20. Here, the state quantity to be controlled is the evaporation temperature Te, but it may be the evaporation pressure Pe. In this case, a target evaporation pressure Pes corresponding to the target evaporation temperature Tes may be used. That is, the evaporating pressure Pe and the evaporating temperature Te, and the target evaporating pressure Pes and the target evaporating temperature Tes mean substantially the same state quantity although the wording itself is different.
As described above, in the cooling operation, as the basic control, superheat degree control by the indoor expansion valves 41 a and 41 b and evaporation temperature control by the compressor 21 are performed. In the air conditioner 1, the room temperature Tra, Trb in each indoor unit 4a, 4b becomes the set temperature Tras, Trbs of the room temperature in each indoor unit 4a, 4b by such basic control of the cooling operation. I have to.

-During heating operation-
When the air conditioning operation is the heating operation, the indoor control means 82 of the control unit 8 causes the supercooling degrees SCra and SCrb of the refrigerant at the outlets of the indoor heat exchangers 42a and 42b to become the target supercooling degrees SCras and SCrbs. Further, the opening degree of each of the indoor expansion valves 41a and 41b is controlled (hereinafter, this control is referred to as “supercooling degree control by the indoor expansion valve”). Here, the degree of supercooling SCra and SCrb are the discharge pressure Pd detected by the discharge pressure sensor 32 and the temperature of the refrigerant on the liquid side of the indoor heat exchangers 42a and 42b detected by the liquid side temperature sensors 45a and 45b. Calculated from Trla and Trlb. More specifically, first, the discharge pressure Pd is converted into the refrigerant saturation temperature to obtain the condensation temperature Tc, which is a state quantity equivalent to the condensation pressure Pc in the refrigerant circuit 10. Here, the condensation pressure Pc represents a high-pressure refrigerant that flows between the discharge side of the compressor 21 and the indoor expansion valves 41a and 41b via the indoor heat exchangers 42a and 42b during the heating operation. Means the pressure to do. Then, the subcooling degrees SCra and SCrb are obtained by subtracting the liquid-side refrigerant temperatures Trla and Trlb of the indoor heat exchangers 42a and 42b from the condensation temperature Tc.

When the air conditioning operation is the heating operation, the capacity control means 81 of the control unit 8 operates the compressor 21 so that the condensation temperature Tc corresponding to the condensation pressure Pe in the refrigerant circuit 10 approaches the target condensation temperature Tcs. The capacity is controlled (hereinafter, this control is referred to as “condensation temperature control by the compressor”). Here, the operation capacity of the compressor 21 is controlled by changing the frequency of the compressor motor 20. Here, the state quantity to be controlled is the condensation temperature Tc, but it may be the condensation pressure Pc. In this case, a target condensation pressure Pcs corresponding to the target condensation temperature Tcs may be used. That is, the condensing pressure Pc and the condensing temperature Tc, and the target condensing pressure Pcs and the target condensing temperature Tcs mean substantially the same state quantity, although the words themselves are different.
Thus, in the heating operation, as the basic control, supercooling degree control by the indoor expansion valves 41a and 41b and condensing temperature control by the compressor 21 are performed. In the air conditioner 1, the room temperature Tra, Trb in each indoor unit 4a, 4b becomes the set temperature Tras, Trbs of the room temperature in each indoor unit 4a, 4b by such basic control of the heating operation. I have to.

-Thermo control-
When the indoor temperature Tra, Trb in each indoor unit 4a, 4b reaches the set temperature Tras, Trbs of the indoor temperature in each indoor unit 4a, 4b by the basic control of the air conditioning operation (cooling operation and heating operation) as described above. The following thermo control is performed.
In this thermo control, a thermo temperature range is set for the set temperatures Tras and Trbs of the indoor units 4a and 4b, and an indoor thermo-off, an indoor thermo-on, an outdoor thermo-off, and an outdoor thermo-on are performed. Here, the indoor thermo-off means that the air-conditioning operation of the corresponding indoor unit is stopped when the room temperature in the indoor unit performing the air-conditioning operation becomes a set temperature. That is, the indoor expansion valve of the corresponding indoor unit is closed so that the refrigerant does not flow into the indoor heat exchanger. The indoor thermo-ON is to restart the air-conditioning operation of the corresponding indoor unit when the indoor temperature in the indoor unit in the indoor thermo-off state deviates from the thermo-temperature range. That is, the indoor expansion valve of the corresponding indoor unit is opened (that is, the degree of superheat or the degree of supercooling is controlled by the indoor expansion valve) so that the refrigerant flows through the indoor heat exchanger. The outdoor thermo-off means that the compressor 21 is stopped when all the indoor units performing the air-conditioning operation are in the indoor thermo-off state. As a result, the flow of the refrigerant in the refrigerant circuit 10 is stopped, and the air conditioner 1 is substantially in a state where all the air conditioning operations are stopped although the operation command for the air conditioning operation is issued. The outdoor thermo-on is to restart the compressor 21 when at least one indoor unit is in the indoor thermo-on state in the outdoor thermo-off state. Thereby, a refrigerant | coolant flows into the refrigerant circuit 10, and the air conditioning apparatus 1 will be in the state by which the air-conditioning driving | operation was restarted. Here, the indoor thermo-off and the indoor thermo-on are performed by the indoor control means 82 of the control unit 8, and the outdoor thermo-off and the outdoor thermo-on are performed by the capacity control means 81 of the control unit 8.

(3) Mode setting of target refrigerant temperature and operation in each mode When the air conditioning operation (cooling operation and heating operation) with the above-described thermo control is performed, the indoor temperatures Tra and Trb in the indoor units 4a and 4b are The indoor units 4a and 4b are controlled so as to become set temperatures Tras and Trbs of the room temperature.
Here, as in Patent Document 1, it is conceivable to vary the target evaporation temperature Tes or the target condensation temperature Tcs according to the air conditioning load characteristics of the building. That is, during the cooling operation, the target evaporation temperature Tes is lowered as the temperature difference between the set temperatures Tras and Trbs and the outdoor temperature Ta increases, and during the heating operation, the temperature between the set temperatures Tras and Trbs and the outdoor temperature Ta. It is conceivable that the target condensation temperature Tes is increased as the difference increases. When the target evaporating temperature Tes or the target condensing temperature Tcs is varied, the target evaporating temperature Tes becomes higher and the target condensing temperature Tcs becomes lower when the demand for air conditioning capacity from the indoor units 4a and 4b is small. Since it becomes low, the excess of the air conditioning capability of the outdoor unit 2 is suppressed. As a result, the operation / stop of the indoor units 4a and 4b and the compressor 21, that is, the repetition frequency of indoor thermo-on / indoor thermo-off and outdoor thermo-on / outdoor thermo-off can be reduced, and energy saving can be improved.

However, on the other hand, the amount of time until the indoor temperatures Tra and Trb of the air-conditioned space reach the set temperatures Tras and Trbs tends to increase by the amount that the air-conditioning capacity of the outdoor unit 2 tends to be suppressed. The comfort may be impaired.
As described above, if the target evaporating temperature Tes or the target condensing temperature Tcs is varied according to the air conditioning load characteristics of the building, satisfaction can be obtained for users who prioritize energy-saving performance, but users who prioritize comfort are required. Satisfaction is difficult to obtain, so it cannot be said that it will be satisfactory to any user.
Therefore, here, in order to give priority to energy saving or comfort according to user preference, as shown in FIG. 2, the target evaporation temperature Tes and the target condensation temperature Tcs are set. A target refrigerant temperature mode setting means 83 for setting a mode related to the target evaporation temperature Tes or the target condensation temperature Tcs, such as setting whether to change or fix, is provided in the control unit 8. Here, the target refrigerant temperature mode setting unit 83 is a memory provided in the outdoor side control unit 38 of the control unit 8, and the target refrigerant temperature mode setting unit 83 is configured to perform target control by communication from an external device for performing various control settings of the air conditioner 1. Various modes related to the evaporation temperature Tes or the target condensation temperature Tcs can be set. The target refrigerant temperature mode setting means 83 is not limited to the above-described one, and for example, the target refrigerant temperature mode setting means 83 relates to the target evaporation temperature Tes and the target condensation temperature Tcs, such as a dip switch provided in the outdoor side control unit 38. Any device that can be set to various modes may be used.

  Next, various modes related to the target evaporating temperature Tes and the target condensing temperature Tcs that can be set by the target refrigerant temperature mode setting means 83 and the operation in each mode will be described with reference to FIGS. Here, FIG. 3 is a diagram showing various modes related to the settable target evaporation temperature Tes and the target condensation temperature Tcs. FIG. 4 is a flowchart showing correction control of the target evaporation temperature Tes in the slow speed variable mode and the quick variable mode (quick mode, powerful mode). FIG. 5 is a flowchart showing correction control of the target condensing temperature Tcs in the slow variable mode and the quick variable mode (quick mode, powerful mode). FIG. 6 shows changes over time from the start of the cooling operation of the target evaporating temperature Tes, the room temperature Tr, and the efficiency in the target refrigerant temperature fixed mode and the target refrigerant temperature variable mode (slow variable mode, quick mode, powerful mode). FIG. FIG. 7 is a diagram showing temporal changes in the target evaporation temperature Tes and the room temperature Tr in the slow variable mode, the quick mode, and the powerful mode when the number of indoor units operated during the cooling operation is increased. FIG. 8 shows changes over time in the target refrigerant temperature fixed mode and the target refrigerant temperature variable mode (slow variable mode, quick mode, powerful mode) from the start of the heating operation of the target condensing temperature Tcs, the room temperature Tr, and the efficiency. FIG. FIG. 9 is a diagram showing temporal changes in the target condensing temperature Tcs and the room temperature Tr in the slow variable mode, the quick mode, and the powerful mode when the number of indoor units operated increases during the heating operation.

<Target refrigerant temperature fixed mode>
First, as a mode relating to the target evaporation temperature Tes and the target condensation temperature Tcs that can be set by the target refrigerant temperature mode setting means 83, as shown in FIG. 3, the target refrigerant temperature fixing mode for fixing the target evaporation temperature Te or the target condensation temperature Tc. There is. When the target refrigerant temperature fixing mode is set, the target evaporation temperature Tes in the cooling operation is fixed to a predetermined value, and the target condensation temperature Tcs in the heating operation is fixed to a predetermined value.
Here, as shown in FIG. 2, the control unit 8 has a means for changing or fixing the target evaporation temperature Tes and the target condensation temperature Tcs according to the mode set by the target refrigerant temperature mode setting means 83. The target refrigerant temperature variable means 84 is provided. Therefore, when the target refrigerant temperature mode setting unit 83 sets the target refrigerant temperature fixed mode, the target refrigerant temperature variable unit 84 fixes the target evaporation temperature Tes in the cooling operation to a predetermined value, and sets the target condensation temperature Tcs in the heating operation. Fixed to a predetermined value.

Here, the target evaporation temperature Tes is fixed to the maximum capacity evaporation temperature Tem (for example, 6 ° C.) corresponding to the case where the air conditioning (cooling) capacity of the outdoor unit 2 is 100%. The target condensing temperature Tcs is fixed to the maximum capacity condensing temperature Tcm (for example, 46 ° C.) corresponding to the case where the air conditioning (heating) capacity of the outdoor unit 2 becomes 100%.
In the target refrigerant temperature fixing mode, the target evaporation temperature Te or the target condensation temperature Tc is always fixed to the maximum capacity evaporation temperature Tem or the maximum capacity condensation temperature Tcm.
Thereby, when setting to target refrigerant temperature fixed mode, as shown in FIG.6 and FIG.8, air-conditioning driving | operation can always be performed in the state where priority was given to comfort. However, since the air conditioning capacity of the outdoor unit 2 tends to be excessive, the efficiency tends to decrease.

<Target refrigerant temperature variable mode>
Next, as a mode related to the target evaporation temperature Tes and the target condensation temperature Tcs that can be set by the target refrigerant temperature mode setting means 83, as shown in FIG. 3, the target refrigerant temperature variable for changing the target evaporation temperature Te or the target condensation temperature Tc. There is a mode. When the target refrigerant temperature variable mode is set, the reference target evaporation temperature KTeb serving as the reference value of the target evaporation temperature Tes in the cooling operation is set automatically or by the user, and the evaporation temperature with respect to the reference target evaporation temperature KTeb is set. By adding the correction value KTec, the target evaporation temperature Tes is changed. That is, the target evaporation temperature Tes can be expressed by an equation of Tes = KTeb + KTec. In the heating operation, the reference target condensing temperature KTcb serving as the reference value of the target condensing temperature Tcs is set automatically or by the user, and the condensing temperature correction value KTcc is added to the reference target condensing temperature KTcb. As a result, the target condensation temperature Tcs is changed. That is, the target condensing temperature Tcs can be expressed by the equation Tcs = KTcb + KTcc.

  Here, as shown in FIG. 3, the target refrigerant temperature variable mode includes two modes (rapid variable mode and slow variable mode) having different degrees of control followability. The rapid variable mode and the slow variable mode are set by the target refrigerant temperature mode setting means 83. In addition, as shown in FIG. 3, the rapid variable mode includes two modes (powerful mode and quick mode) having different levels of control followability. The powerful mode and the quick mode are set by the target refrigerant temperature mode setting means 83. The target refrigerant temperature variable mode includes two modes (automatic mode and high-sensitivity mode) in which the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb is set differently. The automatic mode or the high sensitivity mode is set by the target refrigerant temperature mode setting means 83 together with the rapid variable mode and the slow variable mode. Further, in the target refrigerant temperature variable mode, as shown in FIG. 3, the target evaporation temperature Tes or the target condensation temperature Tcs without correcting the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb set in the high sensitivity mode. There is an eco-mode. The eco mode is set by the target refrigerant temperature mode setting means 83 together with the high sensitivity mode.

  Thus, here, the target refrigerant temperature mode setting means 83 can set either the target refrigerant temperature variable mode or the target refrigerant temperature fixed mode. When the target refrigerant temperature variable mode is set, energy saving can be prioritized as described below, and when the target refrigerant temperature fixed mode is set, comfort can be prioritized as described above. Thereby, according to a user preference here, priority can be given to energy-saving property or comfort can be given priority.

−Auto mode−
In the automatic mode, the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb is set according to the outdoor temperature Ta of the external space where the outdoor unit 2 is arranged. Specifically, when the automatic mode is set by the target refrigerant temperature mode setting unit 83, the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb is set based on a function of the outdoor temperature Ta. In the cooling operation, as the outdoor temperature Ta is higher, the air conditioning (cooling) capability tends to be required. Therefore, the reference target evaporation temperature KTeb is set based on a function that decreases as the outdoor temperature Ta increases. Further, in the heating operation, the air conditioning (heating) capability tends to be required as the outdoor temperature Ta is lower, so the reference target condensing temperature KTcb is set based on a function that increases as the outdoor temperature Ta decreases. . For this reason, when the automatic mode is set by the target refrigerant temperature mode setting unit 83, the target refrigerant temperature varying unit 84 automatically sets the reference target evaporation temperature KTeb in the cooling operation to a temperature value obtained based on the above function and the outdoor temperature Ta. The reference target condensation temperature KTcb in the heating operation is automatically set to a temperature value obtained based on the above function and the outdoor temperature Ta.

  In the automatic mode, during the cooling operation and the heating operation, the reference target evaporation temperature KTeb and the reference target condensing temperature KTcb are changed according to the outdoor temperature Ta, and the following correction in the slow variable mode and the rapid variable mode is further performed. In addition, the target evaporation temperature Te and the target condensation temperature Tc are changed.

(Slow speed variable mode)
When the target refrigerant temperature mode setting means 83 sets the automatic mode and the slow variable mode, the evaporation temperature correction value KTec is changed during the cooling operation, as shown in steps ST1 to ST4 of FIG. . The target evaporation temperature Tes is changed by correcting the reference target evaporation temperature KTeb by adding the evaporation temperature correction value KTec. The control for correcting the target evaporation temperature Tes by changing the evaporation temperature correction value KTec in the slow speed variable mode and adding the evaporation temperature correction value KTec to the reference target evaporation temperature KTeb is performed by the target refrigerant temperature variable means 84. Is done by.

Specifically, at the start of the cooling operation, first, in step ST1, an initial value of the evaporation temperature correction value KTec is set. Here, since the evaporation temperature correction value KTec = 0, the target evaporation temperature Tes = the reference target evaporation temperature KTeb. Thus, the cooling operation is started with the reference target evaporation temperature KTeb as the target evaporation temperature Tes.
And after passing the process which maintains the present condition by step ST2, it transfers to the process of step ST3 or step ST4.
In step ST3, assuming that the first waiting time t1 (for example, 10 minutes) has elapsed from the transition to step ST2 and that the transition condition of step ST5 described later is not satisfied, the indoor units 4a, The room temperature Tra, Trb (hereinafter, subscripts a, b are abbreviated as room temperature Tr) of the air-conditioned space targeted by 4b and the set temperature Tras, Trbs (hereinafter, subscripts a, b) which are target values of the room temperature Tr. Is controlled so as to change the target evaporation temperature Tes according to the temperature difference (Tr−Trs) with respect to the set temperature Trs. Here, when it is determined that the temperature difference (Tr−Trs) satisfies the condition for lowering the target evaporation temperature Tes, the correction value ΔTec1 (for example, 0.5 ° C.) is calculated from the current evaporation temperature correction value KTec. By subtracting, the evaporation temperature correction value KTec is reduced and added to the reference target evaporation temperature KTeb to correct the target evaporation temperature Tes to be lower.

  Here, as a condition of the temperature difference (Tr-Trs), time t2 (for example, for example) compared with the maximum (Tr-Trs) max of the temperature difference (Tr-Trs) among the indoor units in the indoor thermo-ON state. When the (Tr−Trs) max before 5 minutes) is equal to or less than a predetermined temperature difference ΔTre1 (for example, 0.2 ° C.), it is assumed that the slow variable control for correcting the target evaporation temperature Tes to be low is performed. Yes. That is, when a large change is not seen in the room temperature Tr, it is determined that the temperature difference (Tr−Trs) satisfies the condition for lowering the target evaporation temperature Tes. Further, as a condition of the temperature difference (Tr-Trs), among indoor units in the indoor thermo-on state, the maximum temperature difference (Tr-Trs) (Tr-Trs) max is a predetermined temperature difference ΔTre2 (for example, Even when the temperature is larger than 3 ° C.), the slow variable control for correcting the target evaporation temperature Tes to be low is performed. That is, when the room temperature Tr is higher than the set temperature Trs, it is determined that the temperature difference (Tr−Trs) satisfies the condition for lowering the target evaporation temperature Tes.

In step ST4, on the assumption that a first waiting time t1 (for example, 10 minutes) has passed since the transition to step ST2, the indoor temperature Tr and the indoor temperature of the air-conditioned space targeted by the indoor units 4a and 4b Slow speed variable control is performed in which the target evaporation temperature Tes is changed in accordance with a temperature difference (Tr−Trs) from the set temperature Trs that is a target value of Tr. Here, when it is determined that the temperature difference (Tr−Trs) satisfies the condition for increasing the target evaporation temperature Tes, the correction value ΔTec2 (for example, 1 ° C.) is added to the current evaporation temperature correction value KTec. Thus, the evaporation temperature correction value KTec is increased and added to the reference target evaporation temperature KTeb to correct the target evaporation temperature Tes.
Here, as a condition of the temperature difference (Tr-Trs), time t2 (for example, for example) compared with the maximum (Tr-Trs) max of the temperature difference (Tr-Trs) among the indoor units in the indoor thermo-ON state. When the (Tr-Trs) max before (5 minutes) is larger than a predetermined temperature difference ΔTre3 (for example, 0.5 ° C.), the variable speed control is performed so as to correct the target evaporation temperature Tes to be higher. Yes. That is, when the room temperature Tr tends to decrease, it is determined that the temperature difference (Tr−Trs) satisfies a condition that requires the target evaporation temperature Tes to be increased. As a condition for the temperature difference (Tr-Trs), a maximum temperature difference (Tr-Trs) among the indoor units in the indoor thermo-ON state (Tr-Trs) max is a predetermined temperature difference ΔTre4 (for example, Even when the temperature is 0.5 ° C. or less, the slow variable control for correcting the target evaporation temperature Tes to be high is performed. That is, when the room temperature Tr is close to or lower than the set temperature Trs, it is determined that the temperature difference (Tr−Trs) satisfies the condition for increasing the target evaporation temperature Tes.

Then, after passing through the process of step ST3 or step ST4, the process returns to the process of step ST2, and thereafter the processes of steps ST2, ST3, ST4 are repeated.
As shown in FIG. 6, the target evaporation temperature Tes is gradually changed by such a slow speed variable mode, that is, by the slow speed variable control in steps ST2, ST3, and ST4 during the cooling operation. For this reason, excessive air conditioning (cooling) capacity of the outdoor unit 2 can be suppressed, efficiency can be improved easily, and energy saving can be improved.
In addition, since the reference target evaporation temperature KTeb is set according to the outdoor temperature Ta in the automatic mode, the target evaporation set by adding a correction according to the slow variable mode to the reference target evaporation temperature KTeb. The temperature Tes can further improve the degree of energy saving.

Furthermore, the maximum value of the temperature difference between the room temperature Tr and the set temperature Trs is used as a condition for changing the target evaporation temperature Tes in the indoor unit that is in operation (in the state of indoor thermo-ON). For this reason, the target evaporation temperature Tes is changed according to the indoor unit that requires the greatest air conditioning (cooling) capability. Thereby, here, the target evaporation temperature Tes can be changed quickly, and the control followability can be improved.
Further, when the automatic mode is set and the slow variable mode is set by the target refrigerant temperature mode setting means 83, the condensation temperature correction value KTcc is changed during the heating operation, as shown in steps ST11 to ST14 of FIG. Is done. Then, the target condensation temperature Tcs is changed by correcting the reference target condensation temperature KTcb by adding the condensation temperature correction value KTcc. The target refrigerant temperature variable means 84 performs control for correcting the target condensation temperature Tcs by changing the condensation temperature correction value KTcc and adding the condensation temperature correction value KTcc to the reference target condensation temperature KTcb.

Specifically, at the start of the heating operation, first, in step ST11, the initial value of the condensation temperature correction value KTcc is set. Here, since the condensation temperature correction value KTcc = 0, the target condensation temperature Tcs = the reference target condensation temperature KTcb. Thereby, the heating operation is started with the reference target condensation temperature KTcb as the target condensation temperature Tcs.
And after passing the process which maintains the present condition by step ST12, it transfers to the process of step ST13 or step ST14.
In step ST13, on the assumption that the first waiting time t1 (for example, 10 minutes) has elapsed from the transition to step ST12 and that the transition condition of step ST15 described later is not satisfied, 4b is a variable speed control that changes the target condensing temperature Tcs in accordance with the temperature difference (Trs−Tr) between the indoor temperature Tr of the air-conditioned space targeted by 4b and the set temperature Trs that is the target value of the indoor temperature Tr. Here, when it is determined that the temperature difference (Trs−Tr) satisfies the condition for increasing the target condensation temperature Tcs, the correction value ΔTcc1 (for example, 1 ° C.) is added to the current condensation temperature correction value KTcc. Thus, the condensing temperature correction value KTcc is increased and added to the reference target condensing temperature KTcb to correct the target condensing temperature Tcs.

  Here, as a condition of the temperature difference (Trs−Tr), the time t2 (for example, for example, compared to the maximum (Trs−Tr) max of the temperature difference (Trs−Tr) among the indoor units in the indoor thermo-on state). When (Trs-Tr) max before 5 minutes) is equal to or less than a predetermined temperature difference ΔTrc1 (for example, 0.2 ° C.), it is assumed that the slow variable control for correcting the target condensing temperature Tcs to be high is performed. Yes. That is, when no significant change is observed in the room temperature Tr, it is determined that the temperature difference (Trs−Tr) satisfies a condition that requires the target condensation temperature Tcs to be increased. As a condition for the temperature difference (Trs-Tr), the indoor unit in the indoor thermo-on state has the largest temperature difference (Trs-Tr) (Trs-Tr) max is a predetermined temperature difference ΔTrc2 (for example, Even when the temperature is larger than 3 ° C.), the slow variable control for correcting the target condensing temperature Tcs to be high is performed. That is, when the room temperature Tr is lower than the set temperature Trs, it is determined that the temperature difference (Trs−Tr) satisfies the condition that the target condensation temperature Tcs needs to be increased.

In step ST14, on the premise that a first waiting time t1 (for example, 10 minutes) has elapsed since the transition to step ST12, the indoor temperature Tr and the indoor temperature of the air-conditioned space targeted by the indoor units 4a and 4b. Slow speed variable control is performed in which the target condensing temperature Tcs is changed according to a temperature difference (Trs−Tr) from the set temperature Trs, which is a target value of Tr. Here, when it is determined that the temperature difference (Trs−Tr) satisfies the condition for lowering the target condensation temperature Tcs, the correction value ΔTcc2 (for example, 1.5 ° C.) is calculated from the current condensation temperature correction value KTcc. By subtracting, the condensing temperature correction value KTcc is reduced and added to the reference target condensing temperature KTcb to correct the target condensing temperature Tcs.
Here, as a condition of the temperature difference (Trs−Tr), among indoor units in the indoor thermo-on state, the maximum temperature difference (Trs−Tr) (Trs−Tr) max is a predetermined temperature difference ΔTrc3 (for example, , 1.5 ° C.) or less, the slow variable control for correcting the target condensing temperature Tcs to be low is performed. That is, when the room temperature Tr is close to or higher than the set temperature Trs, it is determined that the temperature difference (Trs−Tr) satisfies the condition for lowering the target condensation temperature Tcs.

And after passing through the process of step ST13 or step ST14, it returns to the process of step ST12, and the process of step ST12, ST13, ST14 is repeated after that.
As shown in FIG. 8, the target condensing temperature Tcs is gradually changed by such a slow speed variable mode, that is, the slow speed variable control in steps ST12, ST13, and ST14 during the heating operation. For this reason, the excess of the air conditioning (heating) capability of the outdoor unit 2 can be basically suppressed, the efficiency can be easily improved, and the energy saving performance can be improved.
In addition, here, since the reference target condensation temperature KTcb is set according to the outdoor temperature Ta in the automatic mode, the target condensation set by adding a correction according to the slow speed variable mode to the reference target condensation temperature KTcb. The temperature Tcs can further improve the degree of energy saving.

  Further, here, the maximum value of the temperature difference between the room temperature Tr and the set temperature Trs in the indoor unit that is in operation (in the state of indoor thermo-ON) is used as a condition for changing the target condensation temperature Tcs. For this reason, the target condensation temperature Tcs is changed according to the indoor unit that requires the greatest air conditioning (heating) capacity. Thereby, here, the target condensation temperature Tcs can be quickly changed, and the control followability can be improved.

(Rapidly variable mode)
When the target refrigerant temperature mode setting means 83 sets the automatic mode and the rapid variable mode, the slow speed variable control by the steps ST1 to ST4 similar to the above slow speed variable mode is performed during the cooling operation. When the temperature difference (Tr−Trs) exceeds the threshold temperature difference and the number of indoor units operated increases, the evaporation temperature correction value KTec and the target evaporation temperature Tes are set as shown in step ST5 of FIG. Rapid variable control that is forcibly changed to a rapid follow-up evaporation temperature (here, maximum capacity evaporation temperature Tem and minimum evaporation temperature Teex) is performed.

  Specifically, in step ST5, on the assumption that a first waiting time t1 (for example, 10 minutes) has elapsed since the transition to step ST2, the temperature difference (Tr -Trs) is the largest (Tr-Trs) max is greater than a predetermined temperature difference ΔTre2 (for example, 3 ° C.) as the threshold temperature difference, and the number of indoor units in the current indoor thermo-on state is equal to the time t3 ( For example, when the number is larger than the number of indoor units in the indoor thermo-on state 30 seconds before, rapid variable control is performed to correct the target evaporation temperature Tes so as to be rapidly lowered. That is, when the number of indoor units operated increases (including when the indoor units in the indoor thermo-off state are in the thermo-on state), the outdoor unit 2 needs a large air conditioning (cooling) capacity, It is determined that the condition that the evaporation temperature Tes needs to be lowered rapidly is satisfied.

  Here, there are a powerful mode and a quick mode as the rapid variable mode. In the powerful mode, when the condition that the target evaporation temperature Tes needs to be suddenly lowered is satisfied, the reference target evaporation temperature KTeb is subtracted from the current evaporation temperature correction value KTec, and the rapid follow-up evaporation temperature (here Then, by adding the minimum evaporation temperature Teex exceeding the maximum capacity evaporation temperature Tem), the evaporation temperature correction value KTec is changed, and by adding this to the reference target evaporation temperature KTeb, the target evaporation temperature Tes is used as the rapid follow-up evaporation temperature. Powerful variable control for forcibly changing to the lowest evaporation temperature Teex (for example, 3 ° C.) is performed. That is, the powerful mode is a mode that allows the target evaporation temperature Tes to be changed to the minimum evaporation temperature Teex that exceeds the maximum capacity evaporation temperature Tem. Further, in the quick mode, when the condition that the target evaporation temperature Tes needs to be suddenly lowered is satisfied, the reference target evaporation temperature KTeb is subtracted from the current evaporation temperature correction value KTec and the rapid follow-up evaporation temperature (here Then, by adding the maximum capability evaporation temperature Tem), the evaporation temperature correction value KTec is changed, and by adding this to the reference target evaporation temperature KTeb, the target evaporation temperature Tes is used as the maximum follow-up evaporation temperature Tem ( For example, quick variable control forcibly changing to 6 ° C. is performed. That is, the quick mode is a mode that does not allow the target evaporation temperature Tes to be changed to the minimum evaporation temperature Teex. In addition, the control of correcting the target evaporation temperature Tes by changing the evaporation temperature correction value KTec in the rapid variable mode (powerful mode and quick mode) and adding the evaporation temperature correction value KTec to the reference target evaporation temperature KTeb is also possible. This is performed by the target refrigerant temperature variable means 84.

Then, after the process of step ST5, the process returns to the process of step ST2, and thereafter, the processes of steps ST2, ST3, ST4, and ST5 are repeated.
By such a rapid variable mode, that is, the rapid variable control in steps ST2, ST3, ST4, and ST5 during the cooling operation, as shown in FIG. The target evaporation temperature Tes is changed so as to reach Trs in a short time (that is, in the slow variable mode, the target evaporation temperature Tes reaches the set temperature Trs in a longer time than in the rapid variable mode in the slow variable mode). Will be changed). For this reason, the control followability can be improved by setting the rapid variable mode as compared with the case of setting the slow variable mode. Thereby, here, the degree of control follow-up can be changed according to the user's preference while giving priority to energy saving by setting the target refrigerant temperature variable mode.

  Further, here, unless the temperature difference between the indoor temperature Tr and the set temperature Trs exceeds the threshold temperature difference (here, the predetermined temperature difference ΔTre2) and the number of indoor units operated increases, the step ST3 The target evaporation temperature Tes is changed gradually. For this reason, the excess of the air conditioning (cooling) capability of the outdoor unit 2 can be basically suppressed. In addition, here, when the temperature difference between the indoor temperature Tr and the set temperature Trs exceeds the threshold temperature difference (here, the predetermined temperature difference ΔTre2) and the number of indoor units operated increases, that is, When the outdoor unit 2 needs to have a large air conditioning (cooling) capacity due to the increase in the number of operating units, the target evaporation temperature Tes is set to the rapid follow-up evaporation temperature ( Here, the maximum capacity evaporation temperature Tem and the minimum evaporation temperature Teex) are changed. Thereby, here, energy savings can be improved by varying the target evaporation temperature Tes, and sufficient control followability can be obtained even when the number of operating indoor units increases.

Here, since the reference target evaporation temperature KTeb is set according to the outdoor temperature Ta in the automatic mode, the target evaporation temperature set by correcting the reference target evaporation temperature KTeb according to the rapid variable mode. Tes can further improve the degree of energy saving.
Here, the maximum value of the temperature difference between the room temperature Tr and the set temperature Trs among the indoor units in operation (in the state of indoor thermo-ON) is used as a condition for changing the target evaporation temperature Tes. For this reason, the target evaporation temperature Tes is changed according to the indoor unit that requires the greatest air conditioning (cooling) capability. Thereby, here, the target evaporation temperature Tes can be changed quickly, and the control followability can be improved.
Also, here, as the rapid variable mode (rapid variable control), one of two modes (controls) with different levels of control followability, that is, powerful mode (powerful variable control) and quick mode (quick variable control) is set. Can be done. When the mode is set to the powerful mode, the change to the minimum evaporation temperature Teex exceeding the maximum capacity evaporation temperature Tem is allowed. Therefore, as shown in FIG. 7, when setting to the quick mode or setting to the target refrigerant temperature fixed mode. Compared to the above, the control followability is further improved. Thereby, the degree of control follow-up can be further changed according to the user's preference while improving the control follow-up by setting the rapid variable mode.

When the target refrigerant temperature mode setting means 83 sets the automatic mode and the rapid variable mode, the slow variable control by steps ST11 to ST14 similar to the slow variable mode is performed during the heating operation. When the temperature difference (Trs−Tr) exceeds the threshold temperature difference and the number of indoor units operated increases, the condensation temperature correction value KTcc, the target condensation temperature, as shown in step ST15 of FIG. Rapid variable control is performed in which Tcs is forcibly changed to a rapid follow-up condensation temperature (here, maximum capacity condensation temperature Tcm or maximum condensation temperature Tcex).
Specifically, in step ST15, on the assumption that a first waiting time t1 (for example, 10 minutes) has elapsed since the transition to step ST12, the temperature difference (Trs) among the indoor units in the indoor thermo-on state. -Tr) is the largest (Trs-Tr) max is larger than a predetermined temperature difference ΔTrc2 (for example, 3 ° C.) as the threshold temperature difference, and the number of indoor units in the current indoor thermo-on state is the time t3 ( For example, when the number is larger than the number of indoor units in the indoor thermo-on state 30 seconds before, rapid variable control for correcting the target condensing temperature Tcs so as to increase rapidly is performed. That is, when the number of indoor units operated increases (including the case where an indoor unit in an indoor thermo-off state is in a thermo-on state), the outdoor unit 2 needs a large air conditioning (heating) capacity. It is determined that the condition that the condensation temperature Tcs needs to be lowered rapidly is satisfied.

  Here, there are a powerful mode and a quick mode as the rapid variable mode. In the powerful mode, when the condition that the target condensation temperature Tcs needs to be lowered rapidly is satisfied, the reference target condensation temperature KTcb is subtracted from the current condensation temperature correction value KTcc and the rapid follow-up condensation temperature (here) Then, by adding the maximum condensation temperature Tcex) that exceeds the maximum capacity condensation temperature Tcm, the condensation temperature correction value KTcc is changed, and this is added to the reference target condensation temperature KTcb so that the target condensation temperature Tcs is used as the rapid follow-up condensation temperature. Powerful variable control forcibly changing to the maximum condensation temperature Tcex (for example, 49 ° C.) is performed. That is, the powerful mode is a mode that allows the target condensing temperature Tcs to be changed to the maximum condensing temperature Tcex exceeding the maximum capacity condensing temperature Tcm. Further, in the quick mode, when the condition that the target condensation temperature Tcs needs to be rapidly increased is satisfied, the reference target condensation temperature KTcb is subtracted from the current condensation temperature correction value KTcc and the rapid follow-up condensation temperature (here) Then, by adding the maximum capacity condensing temperature Tcm), the condensing temperature correction value KTcc is changed and added to the reference target condensing temperature KTcb, so that the target condensing temperature Tcs is the maximum capacity condensing temperature Tcm ( For example, quick variable control forcibly changing to 46 ° C. is performed. That is, the quick mode is a mode that does not allow the target condensing temperature Tcs to be changed to the maximum condensing temperature Tcex. In addition, the control of correcting the target condensation temperature Tcs by changing the condensation temperature correction value KTcc in the rapid variable mode (powerful mode and quick mode) and adding the condensation temperature correction value KTcc to the reference target condensation temperature KTcb, This is performed by the target refrigerant temperature variable means 84.

And after passing through the process of step ST15, it returns to the process of step ST12, and the process of step ST12, ST13, ST14, ST15 is repeated after that.
By such a rapid variable mode, that is, rapid variable control in steps ST12, ST13, ST14, and ST15 during heating operation, as shown in FIG. 8, the room temperature Tr is set to a set temperature as compared with the case of the slow variable mode. The target condensing temperature Tcs is changed so as to reach Trs in a short time (that is, in the slow variable mode, the target condensing temperature Tcs is set so that the room temperature Tr reaches the set temperature Trs in a longer time than in the rapid variable mode. Will be changed). For this reason, the control followability can be improved by setting the rapid variable mode as compared with the case of setting the slow variable mode. Thereby, here, the degree of control follow-up can be changed according to the user's preference while giving priority to energy saving by setting the target refrigerant temperature variable mode.

  Further, here, unless the temperature difference between the indoor temperature Tr and the set temperature Trs exceeds the threshold temperature difference (here, the predetermined temperature difference ΔTrc2) and the number of indoor units to be operated increases, step ST13 The target condensing temperature Tcs is gradually changed. For this reason, the excess of the air conditioning (heating) capability of the outdoor unit 2 can be suppressed basically. In addition, here, when the temperature difference between the indoor temperature Tr and the set temperature Trs exceeds the threshold temperature difference (here, the predetermined temperature difference ΔTrc2) and the number of operating indoor units increases, that is, When the outdoor unit 2 needs to have a large air conditioning (heating) capacity due to an increase in the number of operating units, as shown in FIG. 9, the target condensation temperature Tcs is set to the rapid follow-up evaporation temperature ( Here, the maximum capacity condensation temperature Tcm and the maximum condensation temperature Tcex) are changed. Thereby, here, energy savings can be improved by varying the target condensation temperature Tcs, and sufficient control follow-up can be obtained even when the number of indoor units operating is increased.

Here, since the reference target evaporation temperature KTeb is set according to the outdoor temperature Ta in the automatic mode, the target condensation temperature set by correcting the reference target condensation temperature KTeb according to the rapid variable mode. Tcs can further improve the degree of energy saving.
Here, the maximum value of the temperature difference between the room temperature Tr and the set temperature Trs among the indoor units in operation (in the state of indoor thermo-ON) is used as a condition for changing the target condensation temperature Tcs. For this reason, the target condensation temperature Tcs is changed according to the indoor unit that requires the greatest air conditioning (heating) capacity. Thereby, here, the target condensation temperature Tcs can be quickly changed, and the control followability can be improved.
Also, here, as the rapid variable mode (rapid variable control), one of two modes (controls) with different levels of control followability, that is, powerful mode (powerful variable control) and quick mode (quick variable control) is set. Can be done. When the powerful mode is set, the change to the maximum condensing temperature Tcex exceeding the maximum capacity condensing temperature Tcm is allowed. Therefore, as shown in FIG. 9, when setting the quick mode or setting the target refrigerant temperature fixed mode. Compared to the above, the control followability is further improved. Thereby, the degree of control follow-up can be further changed according to the user's preference while improving the control follow-up by setting the rapid variable mode.

(Eco-mode)
When the automatic mode and the eco mode are set by the target refrigerant temperature mode setting means 83, the reference target evaporation set in the automatic mode is different from the rapid variable mode and the slow variable mode during the cooling operation. The reference target evaporation temperature KTeb is set as the target evaporation temperature Tes without correcting the temperature KTeb (that is, only the change according to the outdoor temperature Ta is performed).
Further, when the automatic mode is set and the eco mode is set by the target refrigerant temperature mode setting means 83, the reference set in the automatic mode is different from the above-described rapid variable mode and slow variable mode during heating operation. The reference target condensing temperature KTcb is set as the target condensing temperature Tcs without correcting the target condensing temperature KTcb (that is, only changing according to the outdoor temperature Ta).

  Thus, when the automatic mode of the target refrigerant temperature variable mode is set, the reference target evaporation temperature KTeb or the reference target condensing temperature set in the automatic mode called the eco mode in addition to the rapid variable mode and the slow variable mode. It can be set to any one of three modes including modes with different KTcb correction methods. When the eco mode is set, the target evaporating temperature Tes or the target condensing temperature Tcs is set without correcting the reference target evaporating temperature KTeb or the reference target condensing temperature KTcb. As a result, the degree of control follow-up can be changed according to the user's preference while setting the degree of energy saving by setting the automatic mode.

-High sensitivity mode-
In the high sensitivity mode, unlike the automatic mode, the user sets the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb. Specifically, when the high sensitivity mode is set by the target refrigerant temperature mode setting means 83, the user can set the value of the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb. Here, the reference target evaporation temperature KTeb can be set by selecting one of a plurality of temperature values (for example, 7, 8, 9, 10, 11 ° C.) higher than the maximum capacity evaporation temperature Tem. Further, the reference target condensing temperature KTcb can be set by selecting one of a plurality of temperature values (for example, 41, 43 ° C.) lower than the maximum capacity condensing temperature Tcm.

In the high sensitivity mode, unlike the automatic mode, the reference target evaporation temperature KTeb and the reference target condensation temperature KTcb are set by the user in the cooling operation and the heating operation, and then the slow variable mode similar to the automatic mode is set. The target evaporating temperature Tes and the target condensing temperature Tcs are changed by further adding correction in the rapid variable mode or by not adding correction (eco mode).
Thus, here, when the target refrigerant temperature mode setting unit 83 sets the target refrigerant temperature variable mode, there is a method of setting the reference target evaporation temperature KTeb or the reference target condensing temperature KTcb in the automatic mode and the high sensitivity mode. One of two different modes can be set. When the automatic mode is set, as described above, the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb is set according to the outdoor temperature Ta, so that the reference target evaporation temperature KTeb or the reference target condensation temperature KTcb is rapidly increased. The target evaporating temperature Tes or the target condensing temperature Tcs set by applying correction according to the variable mode and the slow variable mode can further improve the degree of energy saving as compared with the case where the high sensitivity mode is set. . On the other hand, when the high sensitivity mode is set, the degree of energy saving can be set according to the user's preference. Thereby, here, it is possible to change the degree of energy saving according to the user's preference while giving priority to energy saving by setting the target refrigerant temperature variable mode.

(Slow speed variable mode)
When the target refrigerant temperature mode setting means 83 sets the high sensitivity mode and the slow variable mode, as shown in steps ST1 to ST4 of FIG. 4 during the cooling operation, as in the automatic mode. In addition, the evaporation temperature correction value KTec is changed. The target evaporation temperature Tes is changed by correcting the reference target evaporation temperature KTeb by adding the evaporation temperature correction value KTec.
Further, when the high-sensitivity mode and the slow variable mode are set by the target refrigerant temperature mode setting means 83, the steps ST11 to ST14 in FIG. 5 are performed during the heating operation as in the case of the automatic mode. As shown, the condensation temperature correction value KTcc is changed. Then, the target condensation temperature Tcs is changed by correcting the reference target condensation temperature KTcb by adding the condensation temperature correction value KTcc.

(Rapidly variable mode)
When the target refrigerant temperature mode setting means 83 sets the high sensitivity mode and the rapid variable mode (powerful mode or quick mode), the same steps ST1 to ST4 as in the slow variable mode are performed during cooling operation. When the slow variable control is performed, the temperature difference (Tr−Trs) exceeds the threshold temperature difference, and the number of indoor units operated increases, as shown in step ST5 of FIG. Rapid variable control (powerful variable control or quick variable control) in which the value KTec and the target evaporation temperature Tes are forcibly changed to the rapid follow-up evaporation temperature (here, the maximum capacity evaporation temperature Tem and the minimum evaporation temperature Teex) is performed.
When the target refrigerant temperature mode setting means 83 sets the high sensitivity mode and also sets the rapid variable mode (powerful mode or quick mode), the same steps ST11 to ST11 as in the slow variable mode described above are also performed during heating operation. When the slow variable control is performed in ST14, the temperature difference (Trs−Tr) exceeds the threshold temperature difference, and the number of indoor units operated increases, as shown in step ST15 of FIG. Rapid variable control (powerful variable control or quick variable control) is performed in which the temperature correction value KTcc and the target condensation temperature Tcs are forcibly changed to the rapid follow-up condensation temperature (here, the maximum capacity condensation temperature Tcm and the maximum condensation temperature Tcex). Is called.

(Eco-mode)
When the target refrigerant temperature mode setting means 83 sets the high sensitivity mode and the eco mode, the reference set in the high sensitivity mode is different from the rapid variable mode and the slow variable mode during the cooling operation. The reference target evaporation temperature KTeb is set as the target evaporation temperature Tes without correcting the target evaporation temperature KTeb (that is, unlike the automatic mode, without changing according to the outdoor temperature Ta).
In addition, when the high-sensitivity mode is set and the eco-mode is set by the target refrigerant temperature mode setting means 83, during the heating operation, the high-sensitivity mode is set unlike the rapid variable mode and the slow variable mode. The reference target condensing temperature KTcb is set as the target condensing temperature Tcs without correcting the reference target condensing temperature KTcb (that is, unlike the automatic mode, without changing according to the outdoor temperature Ta).

  Thus, when setting the high sensitivity mode of the target refrigerant temperature variable mode, in addition to the rapid variable mode and the slow variable mode, the reference target evaporation temperature KTeb or the reference target set in the high sensitivity mode called the eco mode is set. The condensing temperature KTcb can be set to any one of three modes including different modes. When the eco mode is set, the target evaporating temperature Tes or the target condensing temperature Tcs is set without correcting the reference target evaporating temperature KTeb or the reference target condensing temperature KTcb. As a result, it is possible to change the degree of control follow-up according to the user's preference while setting the degree of energy saving by setting the high sensitivity mode.

(4) Modification 1
In the above embodiment, as shown in FIGS. 4 and 5, the target refrigerant temperature varying means 84 determines whether or not the slow speed variable control (steps ST3, ST4, ST13, ST14) is necessary for each first waiting time t1. In addition, the necessity of the rapid variable control (steps ST5 and ST15) is determined for each first waiting time t1. For this reason, control can be performed only for each first waiting time t1 whether or not the increase in the number of operating indoor units occurs.

However, since the rapid variable control is a case where the number of operating indoor units increases, it is preferable that rapid variable control can be performed quickly.
Therefore, here, as shown in FIGS. 10 and 11, the target refrigerant temperature varying means 84 determines whether or not the slow variable control is necessary every time the first waiting time t1 elapses, and from the first waiting time t1. In addition, the necessity of the rapid variable control is determined every time when the second second waiting time t3 elapses.
For this reason, compared to the slow variable control, the rapid variable control can be performed more frequently, and it is possible to quickly detect that the rapid variable control is necessary.
Thereby, the control followability of rapid variable control can be improved here.

(5) Modification 2
In the embodiment and the first modification, the reference target evaporation temperature KTeb is set according to the outdoor temperature Ta in the automatic mode, and is set by the user in the high sensitivity mode. Here, for example, when the outdoor temperature Ta is high and the indoor temperature Tr is low, the humidity of the air-conditioned space is higher than the relative humidity (generally about 60%) suitable for the indoor temperature Tr. There can be. When the relative humidity increases, uncomfortable feeling increases in the air-conditioned space, so it is necessary to avoid such an operating state.

Therefore, here, the reference target evaporation temperature KTeb is limited to be equal to or lower than the upper limit evaporation temperature set according to the room temperature Tr. For example, the upper limit evaporating temperature can be set based on a function of the room temperature Tr. Here, since the relative humidity tends to decrease as the indoor temperature Tr increases, the upper limit evaporating temperature is set based on a function that increases as the indoor temperature Tr increases.
For this reason, here, by limiting the reference target evaporation temperature KTeb set in the automatic mode or the high sensitivity mode to the upper limit evaporation temperature set according to the room temperature Tr, the humidity of the air-conditioned space becomes the room temperature Tr. The relative humidity can be reduced below.
Thereby, here, the degree of energy saving and the degree of control follow-up can be changed according to the user's preference while suppressing the discomfort in the air-conditioned space.

(6) Modification 3
In the above embodiment and Modifications 1 and 2, the target refrigerant temperature mode setting means 83 is provided in the outdoor side control unit 38, but is not limited thereto. For example, although not shown here, a centralized control device such as a centralized remote controller that controls the air conditioner 1 collectively with a plurality of indoor units (and also with a plurality of outdoor units when there are a plurality of outdoor units). May be provided with the target refrigerant temperature mode setting means 83 in the centralized control device. In this case, the mode setting can be performed more easily.

  The present invention can be widely applied to an air conditioner including a refrigerant circuit configured by connecting a plurality of indoor units to an outdoor unit.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 4a, 4b Indoor unit 81 Capacity control means 84 Target refrigerant temperature variable means

JP 2002-147823 A

Claims (4)

In an air conditioner including a refrigerant circuit (10) configured by connecting a plurality of indoor units (4a, 4b) to an outdoor unit (2),
Capacity control means (81) for controlling the air conditioning capacity of the outdoor unit such that the evaporation temperature or condensation temperature of the refrigerant in the refrigerant circuit becomes the target evaporation temperature or the target condensation temperature;
While performing the slow variable control to change the target evaporation temperature or the target condensation temperature according to the temperature difference between the indoor temperature of the air-conditioned space targeted by the indoor unit and the set temperature that is the target value of the indoor temperature, When the temperature difference exceeds a threshold temperature difference and the number of operating indoor units increases, the target evaporation temperature or the target condensation temperature is forcibly changed to a rapid tracking evaporation temperature or a rapid tracking condensation temperature. Target refrigerant temperature variable means (84) for performing rapid variable control;
An air conditioner (1) comprising: Of the indoor units (4a, 4b) in operation, the maximum value of the temperature difference between the room temperature and the set temperature is used as a condition for changing the target evaporation temperature or the target condensation temperature.
The air conditioner (1) according to claim 1. The target refrigerant temperature variable means determines the necessity of the slow variable control every time the first waiting time elapses, and the rapid variable control every time a second waiting time shorter than the first waiting time elapses. To determine the necessity of
The air conditioner (1) according to claim 1 or 2. In the rapid variable control, the rapid tracking evaporation temperature or the rapid tracking condensation temperature exceeds a maximum capacity evaporation temperature or a maximum capacity condensation temperature corresponding to a case where the air conditioning capacity of the outdoor unit (2) is 100%. Powerful variable control that is changed to the minimum evaporation temperature or the maximum condensation temperature, and quick variable control that the rapid tracking evaporation temperature or the rapid tracking condensation temperature is changed to the maximum capacity evaporation temperature or the maximum capacity condensation temperature. doing,
The air conditioning apparatus (1) according to any one of claims 1 to 3.

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