Air conditioner indoor unit

Abstract

To restrain a draft feeling given to a resident in a room.SOLUTION: An indoor unit (3) for an air conditioner (1) performing an air conditioning operation includes a heat exchanger (31), a casing (41), a plurality of opening and closing members (49), and a control unit (30). The heat exchanger (31) exchanges heat between indoor air and a refrigerant and generates conditioned air. A plurality of blowout ports (46, 46a, 46b) for blowing out the conditioned air is formed in the casing (41). The opening and closing members (49) open and close the blowout ports (46a). The control unit (30) controls an attitude of the opening and closing member (49). The control unit (30) controls the attitude of the opening and closing member (49) so as to close at least one of the blowout ports (46a) during a low load operation in which a load applied to the air conditioning operation is equal to or lower than a prescribed value.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an indoor unit of an air conditioner. [Background technology]

[0002] Patent Document 1 (JP Patent Publication 2011-99613 A) discloses an indoor unit of an air conditioner equipped with multiple air direction adjustment plates provided at multiple air outlets. The indoor unit of Patent Document 1 performs individual air volume suppression control to minimize the volume of air blown out from a specific long side air outlet by changing the position of the four long side air outlets by individually and independently adjusting the rotation state of the four air direction adjustment plates based on a command from the user. Summary of the Invention [Problem to be solved by the invention]

[0003] However, there are cases where the air conditioner of Patent Document 1 described above gives a feeling of cold air to the occupants during heating operation, and gives a feeling of warm air to the occupants during cooling operation or dehumidification operation. [Means for solving the problem]

[0004] The inventors focused on the fact that occupants experience the above-mentioned draft feeling when the air conditioning unit is operating when the indoor temperature approaches the set temperature and the air conditioning load becomes low, and developed the technology disclosed herein.

[0005] An indoor unit of an air conditioner according to a first aspect is an indoor unit of an air conditioner that performs air conditioning operation, and includes a heat exchanger, a casing, multiple opening / closing members, and a control unit. The heat exchanger exchanges heat between indoor air and a refrigerant to generate conditioned air. The casing is formed with multiple air outlets for blowing out the conditioned air. The multiple opening / closing members open and close the multiple air outlets. The control unit controls the attitude of the opening / closing members. The control unit controls the attitude of the opening / closing members so as to close at least one of the multiple air outlets during low-load operation where the load of the air conditioning operation is equal to or lower than a predetermined value.

[0006] According to the indoor unit of the air conditioner of the first aspect, the attitude of the opening and closing member is controlled so as to close at least one of the air outlets during low-load operation where the load of the air conditioner is equal to or lower than a predetermined value. This makes it possible to reduce the amount of heat exchanged between the refrigerant and the indoor air in the heat exchanger during low-load operation. This makes it possible to prevent the temperature of the conditioned air blown out from the air outlet from decreasing during heating operation, and to prevent the temperature of the conditioned air blown out from the air outlet from increasing during cooling operation or dehumidification operation. This makes it possible to prevent the occupant from feeling cold air during heating operation of the air conditioner, and to prevent the occupant from feeling warm air during cooling operation or dehumidification operation. This makes it possible to suppress the feeling of a draft.

[0007] An indoor unit of an air conditioning apparatus according to a second aspect is an indoor unit of the air conditioning apparatus according to the first aspect, wherein the control unit controls the posture of the opening / closing member to close at least one of the multiple air outlets when the condensation temperature of the refrigerant in the heat exchanger drops to a first threshold value during heating operation.

[0008] When the condensation temperature of the refrigerant drops during heating operation, the temperature of the conditioned air that has exchanged heat with the refrigerant in the heat exchanger drops. For this reason, in the indoor unit of the air conditioner according to the second aspect, the first threshold value is set to a lower limit value that does not give a feeling of cold air during heating operation, and when the condensation temperature drops to the first threshold value, control is performed so that at least one of the air outlets is closed by the opening and closing member. This makes it possible to prevent the temperature of the conditioned air blown out from the air outlet from dropping to a level that gives a feeling of cold air during heating operation.

[0009] An indoor unit of an air conditioning apparatus according to a third aspect is the indoor unit of the air conditioning apparatus according to the second aspect, wherein the control unit controls the posture of the opening / closing member to close at least one of the multiple air outlets when the condensation temperature of the refrigerant in the heat exchanger drops to a first threshold value during heating operation and the temperature of the indoor air continues to rise.

[0010] In the indoor unit of the air conditioner according to the third aspect, in addition to the second aspect, when the temperature of the indoor air rises during heating operation, the heating load becomes lower, so the temperature of the conditioned air that has been heat exchanged in the heat exchanger is likely to fall. Therefore, when the condensation temperature falls during heating operation and the temperature of the indoor air rises, the effect of suppressing the feeling of cold air by having the control unit close at least one of the air outlets with the opening and closing member is high.

[0011] An indoor unit of an air conditioning apparatus according to a fourth aspect is an indoor unit of the air conditioning apparatus according to the first aspect, wherein the control unit controls the posture of the opening / closing member to close at least one of the multiple air outlets when the evaporation temperature of the refrigerant in the heat exchanger rises to a second threshold value during cooling operation or dehumidification operation.

[0012] When the evaporation temperature of the refrigerant drops during cooling or dehumidifying operation, the temperature of the conditioned air that has been heat exchanged in the heat exchanger rises. For this reason, in the indoor unit of the air conditioner according to the fourth aspect, the second threshold is set to an upper limit value that does not give a feeling of warm air during cooling or dehumidifying operation, and the attitude of the opening and closing member is controlled to close at least one of the air outlets when the evaporation temperature rises to the second threshold. This makes it possible to prevent the conditioned air blown out of the air outlet from rising to a temperature that gives a feeling of warm air during cooling or dehumidifying operation.

[0013] An indoor unit of an air conditioning apparatus according to a fifth aspect is an indoor unit of an air conditioning apparatus according to the fourth aspect, and controls the posture of an opening / closing member to close at least one of a plurality of air outlets when the evaporation temperature of the refrigerant in the heat exchanger rises to a second threshold value during cooling operation or dehumidification operation and the indoor air temperature continues to fall.

[0014] In the indoor unit of the air conditioner according to the fifth aspect, in addition to the fourth aspect, when the temperature or humidity of the indoor air drops during cooling operation or dehumidification operation, the cooling load or dehumidification load becomes lower, so the temperature of the conditioned air that has undergone heat exchange in the heat exchanger is likely to rise. Therefore, when the evaporation temperature rises and the temperature of the indoor air drops during cooling operation or dehumidification operation, it is highly effective to close at least one of the air outlets by the control unit with the opening and closing member.

[0015] An indoor unit of an air conditioner according to a sixth aspect is the indoor unit of the air conditioner according to the fourth or fifth aspect, wherein the second threshold value is a dew point temperature of the indoor air.

[0016] During cooling operation, when the evaporation temperature of the refrigerant rises to the dew point temperature of the indoor air, the indoor air is no longer cooled to the refrigerant in the heat exchanger. For this reason, in the indoor unit of the air conditioner according to the sixth aspect, the dew point temperature is set as the second threshold value so that the indoor air is cooled to the refrigerant in the heat exchanger. This makes it possible to perform cooling operation or dehumidification operation during low load operation while maintaining the refrigerant at or below the dew point temperature. Therefore, it is possible to realize an indoor unit that suppresses the feeling of warm air being given to the occupants during cooling operation or dehumidification operation.

[0017] An indoor unit of an air conditioner according to a seventh aspect is the indoor unit of the air conditioner according to the first aspect to the sixth aspect, in which three or more air outlets are formed in the casing. The control unit controls the attitudes of the multiple opening / closing members so that after at least one of the multiple air outlets is closed by the opening / closing member, at least one of the other air outlets is closed by the opening / closing member.

[0018] In the indoor unit of the air conditioner relating to the seventh aspect, after at least one air outlet is closed with an opening / closing member, if suppression of the draft feeling is insufficient, further air outlets can be controlled to be closed with the opening / closing member.

[0019] The indoor unit of an air conditioning apparatus according to an eighth aspect is an indoor unit of an air conditioning apparatus according to the first aspect to the seventh aspect, in which the control unit controls at least one of the air outlets located in a direction facing in the direction in which no people are present to be closed by an opening / closing member.

[0020] In the indoor unit of the air conditioner pertaining to the eighth aspect, after at least one of the air outlets is closed, it is possible to blow out conditioned air with a reduced draft feeling. Therefore, by supplying conditioned air with a reduced draft feeling in the direction where people are present, it is possible to improve comfort.

[0021] An indoor unit of an air conditioner according to a ninth aspect is the indoor unit of the air conditioner according to the first to eighth aspects, wherein one opening and closing member opens and closes one air outlet.

[0022] In the indoor unit of the air conditioner pertaining to the ninth aspect, one opening / closing member is provided for one air outlet, and therefore it is easy to control the closing of the air outlet with the opening / closing member. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic configuration diagram of an air conditioning apparatus according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an external perspective view of an indoor unit that constitutes the air conditioning apparatus. [Diagram 3] FIG. 3 is a schematic side cross-sectional view of the indoor unit, taken along line IOI in FIG. 2. [Figure 4] FIG. 2 is a control block diagram of the air conditioning apparatus. [Diagram 5] FIG. 4 is a diagram for explaining control of a heating operation according to an embodiment of the present disclosure. [Figure 6] FIG. 4 is a diagram for explaining control of a cooling operation and a dehumidification operation according to an embodiment of the present disclosure. [Figure 7] 4 is a flowchart illustrating a method for controlling an opening / closing member according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] (1) Air conditioning equipment configuration As shown in Fig. 1, an air conditioner 1 employing an indoor unit 3 according to an embodiment of the present disclosure is a device that conditions the air inside a building or the like by a vapor compression refrigeration cycle. The air conditioner 1 mainly has an outdoor unit 2, an indoor unit 3, and a liquid refrigerant connection pipe 4 and a gas refrigerant connection pipe 5 that connect the outdoor unit 2 and the indoor unit 3. A vapor compression refrigerant circuit 10 of the air conditioner 1 is formed by connecting the outdoor unit 2 and the indoor unit 3 via the liquid refrigerant connection pipe 4 and the gas refrigerant connection pipe 5.

[0025] (1-1) Outdoor unit The outdoor unit 2 is installed outdoors (on the roof of a building, near the exterior wall of a building, etc.). As described above, the outdoor unit 2 is connected to the indoor unit 3 via the liquid refrigerant connection pipe 4 and the gas refrigerant connection pipe 5, and constitutes a part of the refrigerant circuit 10. The outdoor unit 2 mainly has a compressor 21, a four-way switching valve 23, an outdoor heat exchanger 24, and an expansion valve 25.

[0026] The compressor 21 is a mechanism for compressing a low-pressure refrigerant in a refrigeration cycle until it becomes high pressure. Here, a compressor of a sealed structure in which a volumetric compression element (not shown), such as a rotary type or scroll type, is rotated and driven by a compressor motor 22 is used as the compressor 21. Here, the rotation speed (frequency) of the compressor motor 22 can be controlled by an inverter or the like, and thus the capacity of the compressor 21 can be controlled.

[0027] The four-way switching valve 23 is a valve for switching the direction of the refrigerant flow when switching between cooling or dehumidifying operation and heating operation. During cooling or dehumidifying operation, the four-way switching valve 23 connects the discharge side of the compressor 21 to the gas side of the outdoor heat exchanger 24, and connects the gas side of an indoor heat exchanger 31 (described later) to the suction side of the compressor 21 via a gas refrigerant connection pipe 5 (see the solid line of the four-way switching valve 23 in FIG. 1). During heating operation, the four-way switching valve 23 connects the discharge side of the compressor 21 to the gas side of the indoor heat exchanger 31 via the gas refrigerant connection pipe 5, and connects the gas side of the outdoor heat exchanger 24 to the suction side of the compressor 21 (see the dashed line of the four-way switching valve 23 in FIG. 1).

[0028] The outdoor heat exchanger 24 is a heat exchanger that functions as a refrigerant radiator during cooling or dehumidifying operation, and functions as a refrigerant evaporator during heating operation. The outdoor heat exchanger 24 has its liquid side connected to the expansion valve 25 and its gas side connected to the four-way switching valve 23.

[0029] The expansion valve 25 is an expansion mechanism that can reduce the pressure of the high-pressure liquid refrigerant that has dissipated heat in the outdoor heat exchanger 24 before being sent to the indoor heat exchanger 31 during cooling or dehumidifying operation, and can reduce the pressure of the high-pressure liquid refrigerant that has dissipated heat in the indoor heat exchanger 31 before being sent to the outdoor heat exchanger 24 during heating operation. Here, an electric expansion valve whose opening degree can be controlled is used as the expansion valve 25.

[0030] The outdoor unit 2 is also provided with an outdoor fan 26 for drawing outdoor air into the outdoor unit 2, supplying the outdoor air to the outdoor heat exchanger 24, and then discharging the air outside the outdoor unit 2. For this reason, the outdoor heat exchanger 24 uses the outdoor air as a cooling or heating source to dissipate heat or evaporate the refrigerant. The outdoor fan 26 is rotationally driven by an outdoor fan motor 27.

[0031] In addition, various sensors are provided in the outdoor unit 2. Specifically, the outdoor unit 2 is provided with a suction pressure sensor 28a that detects the suction pressure of the compressor 21, a suction temperature sensor 28b that detects the suction temperature of the compressor 21, a discharge pressure sensor 29a that detects the discharge pressure of the compressor 21, and a discharge temperature sensor 29b that detects the discharge temperature of the compressor 21.

[0032] (1-2) Refrigerant connection pipe The refrigerant connection pipes 4, 5 are refrigerant pipes that are installed on-site when the air conditioning apparatus 1 is installed at an installation location such as a building. One end of the liquid refrigerant connection pipe 4 is connected to the expansion valve 25 side of the outdoor unit 2, and the other end of the liquid refrigerant connection pipe 4 is connected to the liquid side of the indoor heat exchanger 31 of the indoor unit 3. One end of the gas refrigerant connection pipe 5 is connected to the four-way switching valve 23 side of the outdoor unit 2, and the other end of the gas refrigerant connection pipe 5 is connected to the gas side of the indoor heat exchanger 31 of the indoor unit 3.

[0033] (1-3) Indoor unit The indoor unit 3 is installed indoors (inside a building). As described above, the indoor unit 3 is connected to the outdoor unit 2 via the liquid refrigerant connection pipe 4 and the gas refrigerant connection pipe 5, and constitutes a part of the refrigerant circuit 10. As shown in Figs. 1 to 3, the indoor unit 3 mainly has a casing 41, an opening and closing member 49, an indoor heat exchanger 31, and an indoor fan 32. Here, a type of indoor unit called a ceiling embedded type is adopted as the indoor unit 3.

[0034] As shown in Figures 2 and 3, the casing 41 houses the components therein. The casing 41 is composed of a casing body 41a and a decorative panel 42 arranged below the casing body 41a. As shown in Figure 2, the casing body 41a is inserted into an opening formed in the ceiling U. The decorative panel 42 is arranged to be fitted into the opening in the ceiling U.

[0035] 2 and 3, the casing body 41a is a box-like body having a generally octagonal shape in plan view with alternating long and short sides, and has an open bottom. The casing body 41a has a generally octagonal top plate 43 with alternating long and short sides, and a side plate 44 extending downward from the periphery of the top plate 43.

[0036] The decorative panel 42 constitutes the lower surface of the casing 41, is a plate-like body having a substantially polygonal shape (here, substantially rectangular shape) in a plan view, and is mainly composed of a panel body 42a fixed to the lower end of the casing body 41a. The panel body 42a has, approximately at its center, an intake port 45 for drawing in indoor air, and an outlet port 46 for blowing out conditioned air into the room.

[0037] The intake port 45 is an opening having a substantially rectangular shape. The intake port 45 is provided with an intake grille 47 and an intake filter 48 for removing dust in the air taken in through the intake port 45.

[0038] In a plan view, the air outlet 46 is formed to surround the periphery of the air inlet 45. The air outlet 46 has a plurality of (four here) side air outlets 46a formed along each side of the quadrangle of the panel main body 42a, and a plurality of (four here) corner air outlets 46b formed at the corners of the panel main body 42a.

[0039] The multiple opening / closing members 49 open and close the multiple air outlets 46. When the opening / closing members 49 open the air outlets 46, conditioned air is blown out from the air outlets 46. When the opening / closing members 49 close the air outlets 46, conditioned air is not blown out from the air outlets 46. The opening / closing members 49 can close the entire air outlet 46, close a part of the air outlet 46, or open the entire air outlet 46. The opening / closing members 49 can also change the direction of the conditioned air blown out from the air outlets 46 into the room.

[0040] In this embodiment, an opening / closing member 49 is provided at each of the multiple air outlets 46a. In other words, one opening / closing member 49 opens and closes one air outlet 46a. Here, four opening / closing members 49 are provided at the four side air outlets 46a, respectively. On the other hand, no opening / closing member 49 is provided at the corner air outlet 46b.

[0041] The opening / closing member 49 is a plate-like member that extends in an elongated manner along the longitudinal direction of the side air outlet 46a. The opening / closing member 49 is configured to be rotated about an axis in the longitudinal direction to open and close the air outlet 46. The opening / closing member 49 is also configured to be rotated about an axis in the longitudinal direction to change the wind direction angle in the vertical direction.

[0042] Inside the casing body 41a, the indoor heat exchanger 31 and the indoor fan 32 are mainly arranged.

[0043] The indoor heat exchanger 31 exchanges heat between the indoor air and the refrigerant to generate conditioned air. The indoor heat exchanger 31 is a heat exchanger that functions as a refrigerant evaporator during cooling or dehumidifying operation, and functions as a refrigerant radiator during heating operation. The liquid side of the indoor heat exchanger 31 is connected to the liquid refrigerant connection pipe 4, and the gas side is connected to the gas refrigerant connection pipe 5.

[0044] The indoor heat exchanger 31 is a heat exchanger that is bent and disposed so as to surround the periphery of the indoor fan 32 in a plan view. The indoor heat exchanger 31 exchanges heat between the refrigerant and the indoor air drawn into the casing main body 41a by the indoor fan 32. In addition, a drain pan 31a is disposed below the indoor heat exchanger 31 for receiving drain water generated when moisture in the indoor air is condensed by the indoor heat exchanger 31. The drain pan 31a is attached to the lower part of the casing main body 41a.

[0045] The indoor fan 32 is a fan that draws indoor air into the casing body 41a through the intake port 45 of the decorative panel 42 and blows it out from the casing body 41a into the room through the exhaust port 46 of the decorative panel 42. For this reason, the indoor heat exchanger 31 uses the indoor air as a cooling or heating source to dissipate heat or evaporate the refrigerant. Here, a centrifugal fan that draws in indoor air from below and blows it out toward the outer periphery in a plan view is used as the indoor fan 32. The indoor fan 32 is driven to rotate by an indoor fan motor 33 provided in the center of the top plate 43 of the casing body 41a. Here, the rotation speed (frequency) of the indoor fan motor 33 can be controlled by an inverter or the like, and thus the air volume of the indoor fan 32 can be controlled.

[0046] Specifically, four air volumes are prepared for the indoor fan 32: maximum air volume H, medium air volume M which is smaller than air volume H, small air volume L which is smaller than air volume M, and minimum air volume LL which is smaller than air volume L. Here, air volume LL is an air volume that cannot be set by the resident using the remote control 60 (described later).

[0047] Furthermore, various sensors are provided in the indoor unit 3. Specifically, the indoor unit 3 is provided with an indoor temperature sensor 34 and an indoor humidity sensor 35 that detect the temperature (indoor temperature Tr) and humidity (indoor humidity Hr) of the indoor air drawn into the indoor unit 3. Here, the indoor temperature sensor 34 and the indoor humidity sensor 35 are disposed near the intake port 45.

[0048] The indoor unit 3 is also provided with a human detection sensor 36 that detects the position of a person in the room. Here, an infrared sensor having one or more infrared receiving elements is used as the human detection sensor 36, and is provided at a corner of the decorative panel 42. Note that the human detection sensor 36 does not have to be provided at the corner of the decorative panel 42, and may be provided in another part of the indoor unit 3, or may be provided somewhere in the room instead of in the indoor unit 3.

[0049] (2) Air conditioner control configuration As shown in Fig. 4, the air conditioning apparatus 1 has a control device 6 in which an outdoor control unit 20, an indoor control unit 30, and a remote control 60 are connected via transmission lines and communication lines in order to control the operation of the constituent devices. The outdoor control unit 20 is provided in the outdoor unit 2. The indoor control unit 30 is provided in the indoor unit 3. The remote control 60 is provided indoors. Note that here, the outdoor control unit 20, the indoor control unit 30, and the remote control 60 are wired connected via transmission lines and communication lines, but they may also be connected wirelessly.

[0050] The outdoor control unit 20, the indoor control unit 30 of the air conditioner 1 and the control unit of the remote control 60 perform various calculations and processes, and are realized by, for example, a calculation processing device such as a CPU.

[0051] (2-1) Outdoor control unit As described above, the outdoor control unit 20 is provided in the outdoor unit 2, and mainly includes an outdoor CPU 20a, an outdoor transmission unit 20b, and an outdoor storage unit 20c. The outdoor control unit 20 is configured to receive detection signals from an intake pressure sensor 28a, an intake temperature sensor 28b, a discharge pressure sensor 29a, and a discharge temperature sensor 29b.

[0052] The outdoor CPU 20a is connected to an outdoor transmission unit 20b and an outdoor memory unit 20c. The outdoor transmission unit 20b transmits control data and the like to and from the indoor control unit 30. The outdoor memory unit 20c stores the control data and the like. The outdoor CPU 20a transmits and reads and writes the control data and the like via the outdoor transmission unit 20b and the outdoor memory unit 20c, while controlling the operation of the compressor 21, four-way switching valve 23, expansion valve 25, outdoor fan 26, and the like, which are components provided in the outdoor unit 2.

[0053] (2-2) Indoor control unit As described above, the indoor control unit 30 is provided in the indoor unit 3, and mainly has an indoor CPU 30a, an indoor transmission unit 30b, an indoor storage unit 30c, and an indoor communication unit 30d. The indoor control unit 30 is configured to be able to receive detection signals from the indoor temperature sensor 34, the indoor humidity sensor 35, and the human detection sensor 36.

[0054] The indoor CPU 30a is connected to the indoor transmission unit 30b, the indoor storage unit 30c, and the indoor communication unit 30d. The indoor transmission unit 30b transmits control data and the like to the outdoor control unit 20. The indoor storage unit 30c stores the control data and the like. The indoor communication unit 30d transmits and receives the control data and the like to and from the remote control 60. The indoor CPU 30a controls the operation of the indoor fan 32, the opening and closing member 49, and the like as components provided in the indoor unit 3, while transmitting, reading, writing, and transmitting and receiving the control data and the like via the indoor transmission unit 30b, the indoor storage unit 30c, and the indoor communication unit 30d.

[0055] (2-3) Remote Control As described above, the remote control 60 is provided indoors, and mainly includes a remote control CPU 61, a remote control storage unit 62, a remote control communication unit 63, a remote control operation unit 64, and a remote control display unit 65.

[0056] The remote control CPU 61 is connected to a remote control storage unit 62, a remote control communication unit 63, a remote control operation unit 64, and a remote control display unit 65. The remote control storage unit 62 stores control data, etc. The remote control communication unit 63 transmits and receives control data, etc. with the indoor communication unit 30d. The remote control operation unit 64 accepts input of control commands, etc. from the resident. The remote control display unit 65 performs operation display, etc. The remote control CPU 61 accepts input of operation commands, control commands, etc. via the remote control operation unit 64, reads and writes control data, etc. to the remote control storage unit 62, and performs display of the operation state and control state on the remote control display unit 65, while issuing control commands, etc. to the indoor control unit 30 via the remote control communication unit 63.

[0057] In this way, the air conditioner 1 has a control device 6 that controls the operation of the constituent devices. The control device 6 controls the constituent devices, such as the compressor 21, four-way switching valve 23, expansion valve 25, outdoor fan 26, indoor fan 32, and opening / closing member 49, based on detection signals from the suction pressure sensor 28a, suction temperature sensor 28b, discharge pressure sensor 29a, discharge temperature sensor 29b, indoor temperature sensor 34, indoor humidity sensor 35, and human detection sensor 36, and is configured to perform air conditioning operations such as cooling operation, dehumidification operation, and heating operation, as well as various controls.

[0058] (3) Driving behavior Next, there will be described the operation of the air conditioner 1. The air conditioner 1 of this embodiment performs heating operation, cooling operation, and dehumidification operation as air conditioning operations.

[0059] (3-1) Heating operation Heating operation is performed by the control device 6, which receives a command for heating operation via the remote control operation unit 64, controlling the operation of the compressor 21, four-way switching valve 23, expansion valve 25, outdoor fan 26, indoor fan 32, opening / closing member 49, etc., which are components of the outdoor unit 2 and the indoor unit 3.

[0060] In heating operation, the four-way switching valve 23 is switched so that the outdoor heat exchanger 24 functions as an evaporator of the refrigerant and the indoor heat exchanger 31 functions as a radiator of the refrigerant (the state shown by the dashed line of the four-way switching valve 23 in Figure 1).

[0061] In the refrigerant circuit 10 in this state, the low-pressure refrigerant in the refrigeration cycle is sucked into the compressor 21, compressed to the high pressure in the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 21 is sent to the indoor heat exchanger 31 through the four-way switching valve 23 and the gas refrigerant communication pipe 5. In the indoor heat exchanger 31, the high-pressure refrigerant exchanges heat with the indoor air supplied by the indoor fan 32 and dissipates heat. As a result, the indoor air is heated and blown out into the room. The high-pressure refrigerant that has dissipated heat in the indoor heat exchanger 31 is sent to the expansion valve 25 through the liquid refrigerant communication pipe 4 and is reduced in pressure to the low pressure in the refrigeration cycle. The low-pressure refrigerant reduced in pressure in the expansion valve 25 is sent to the outdoor heat exchanger 24. In the outdoor heat exchanger 24, the low-pressure refrigerant exchanges heat with the outdoor air supplied by the outdoor fan 26 and evaporates. The low-pressure refrigerant evaporated in the outdoor heat exchanger 24 is sucked back into the compressor 21 through the four-way selector valve 23. In this manner, during heating operation, the control device 6 controls the refrigerant sealed in the refrigerant circuit 10 to circulate through the compressor 21, the indoor heat exchanger 31, the expansion valve 25, and the outdoor heat exchanger 24 in this order.

[0062] During heating operation, the control device 6 performs capacity control to control the capacity of the compressor 21 so that the condensation temperature Tc of the refrigerant in the refrigerant circuit 10 approaches a predetermined target condensation temperature Tcs. The capacity control of the compressor 21 is performed by controlling the rotation speed (frequency) of the motor 22.

[0063] The predetermined target condensation temperature is determined, for example, by the temperature difference between the room temperature Tr detected by the room temperature sensor 34 and the set temperature Trs set by the occupant through the remote control operation unit 64 of the remote control 60.

[0064] The refrigerant condensation temperature Tc is obtained by converting the discharge pressure detected by the discharge pressure sensor 29a into the saturation temperature of the refrigerant. The refrigerant condensation temperature Tc means a temperature obtained by converting a pressure (the condensation pressure of the refrigerant in the refrigerant circuit 10) representative of the high-pressure refrigerant flowing from the discharge side of the compressor 21 to the expansion valve 25 via the indoor heat exchanger 31 into the saturation temperature of the refrigerant during heating operation, or the saturation temperature of the refrigerant in the indoor heat exchanger 31 that functions as a radiator of the refrigerant. Therefore, when a temperature sensor is provided in the indoor heat exchanger 31, the temperature of the refrigerant detected by this temperature sensor may be used as the refrigerant condensation temperature Tc.

[0065] (3-2) Cooling operation The cooling operation is performed by the control device 6, which receives a command for cooling operation via the remote control operation unit 64, controlling the operation of the outdoor unit 2 and the indoor unit 3, such as the compressor 21, four-way switching valve 23, expansion valve 25, outdoor fan 26, indoor fan 32, opening / closing member 49, etc.

[0066] In cooling operation, the four-way switching valve 23 is switched so that the outdoor heat exchanger 24 functions as a refrigerant radiator and the indoor heat exchanger 31 functions as a refrigerant evaporator (the state shown by the solid line of the four-way switching valve 23 in Figure 1).

[0067] In the refrigerant circuit 10 in this state, the low-pressure refrigerant in the refrigeration cycle is sucked into the compressor 21, compressed to the high pressure in the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 21 is sent to the outdoor heat exchanger 24 through the four-way switching valve 23. In the outdoor heat exchanger 24, the high-pressure refrigerant exchanges heat with the outdoor air supplied by the outdoor fan 26 and dissipates heat. The high-pressure refrigerant that has dissipated heat in the outdoor heat exchanger 24 is sent to the expansion valve 25 and reduced in pressure to the low pressure in the refrigeration cycle. The low-pressure refrigerant reduced in pressure in the expansion valve 25 is sent to the indoor heat exchanger 31 through the liquid refrigerant connection pipe 4. In the indoor heat exchanger 31, the low-pressure refrigerant exchanges heat with the indoor air supplied by the indoor fan 32 and evaporates. As a result, the indoor air is cooled and blown out into the room. The low-pressure refrigerant evaporated in the indoor heat exchanger 31 is sucked back into the compressor 21 through the gas refrigerant communication pipe 5 and the four-way switching valve 23. In this manner, during cooling operation, the control device 6 controls the refrigerant sealed in the refrigerant circuit 10 to circulate through the compressor 21, the outdoor heat exchanger 24, the expansion valve 25, and the indoor heat exchanger 31 in this order.

[0068] During cooling operation, the control device 6 performs capacity control to control the capacity of the compressor 21 so that the evaporation temperature Te of the refrigerant in the refrigerant circuit 10 approaches a predetermined target evaporation temperature Teds. The capacity control of the compressor 21 is performed by controlling the rotation speed (frequency) of the motor 22.

[0069] The predetermined target evaporation temperature Teds is determined, for example, by the temperature difference between the room temperature Tr detected by the room temperature sensor 34 and the set temperature Trs set by the occupant through the remote control operation unit 64 of the remote control 60.

[0070] The evaporation temperature Te of the refrigerant is obtained by converting the suction pressure detected by the suction pressure sensor 28a into the saturation temperature of the refrigerant. The evaporation temperature Te of the refrigerant means a temperature obtained by converting a pressure (evaporation pressure of the refrigerant in the refrigerant circuit 10) representative of the low-pressure refrigerant in the refrigeration cycle that flows from the outlet of the expansion valve 25 to the suction side of the compressor 21 via the indoor heat exchanger 31 during cooling operation into the saturation temperature of the refrigerant, or the saturation temperature of the refrigerant in the indoor heat exchanger 31 that functions as an evaporator of the refrigerant. Therefore, when a temperature sensor is provided in the indoor heat exchanger 31, the temperature of the refrigerant detected by this temperature sensor may be used as the evaporation temperature Te of the refrigerant.

[0071] (3-3) Dehumidification operation The dehumidification operation is performed by the control device 6, which receives a command for dehumidification operation via the remote control operation unit 64, controlling the operation of the compressor 21, four-way switching valve 23, expansion valve 25, outdoor fan 26, indoor fan 32, opening / closing member 49, etc., which are components of the outdoor unit 2 and the indoor unit 3.

[0072] In dehumidification operation, as in cooling operation, the four-way switching valve 23 is switched so that the outdoor heat exchanger 24 functions as a refrigerant radiator and the indoor heat exchanger 31 functions as a refrigerant evaporator (the state shown by the solid line of the four-way switching valve 23 in Figure 1).

[0073] In the refrigerant circuit 10 in this state, the low-pressure refrigerant in the refrigeration cycle is sucked into the compressor 21, compressed to the high pressure in the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 21 is sent to the outdoor heat exchanger 24 through the four-way switching valve 23. In the outdoor heat exchanger 24, the high-pressure refrigerant exchanges heat with the outdoor air supplied by the outdoor fan 26 and dissipates heat. The high-pressure refrigerant that has dissipated heat in the outdoor heat exchanger 24 is sent to the expansion valve 25 and reduced in pressure to the low pressure in the refrigeration cycle. The low-pressure refrigerant reduced in pressure in the expansion valve 25 is sent to the indoor heat exchanger 31 through the liquid refrigerant connection pipe 4. In the indoor heat exchanger 31, the low-pressure refrigerant exchanges heat with the indoor air supplied by the indoor fan 32 and evaporates. As a result, the indoor air is dehumidified and blown out into the room. The low-pressure refrigerant evaporated in the indoor heat exchanger 31 is sucked back into the compressor 21 through the gas refrigerant communication pipe 5 and the four-way switching valve 23. In this manner, during dehumidification operation, the control device 6 controls the refrigerant sealed in the refrigerant circuit 10 to circulate through the compressor 21, the outdoor heat exchanger 24, the expansion valve 25, and the indoor heat exchanger 31 in this order.

[0074] The capacity control of the compressor 21 during dehumidification operation is similar to the capacity control of the compressor 21 during cooling operation, except that the target evaporation temperature Tecs during cooling operation is set as the target evaporation temperature Teds. The target evaporation temperature Teds during dehumidification operation is set to a value equal to or lower than the target evaporation temperature Tecs during cooling operation.

[0075] (4) Control of opening and closing components The indoor control unit 30 controls the attitude of the multiple opening / closing members 49. In other words, the indoor control unit 30 controls the opening and closing of the air outlets 46 of the multiple opening / closing members 49. The indoor control unit 30 controls the attitude of the opening / closing members 49 so as to close at least one of the multiple air outlets 46 during low-load operation where the load of the air conditioning operation is equal to or lower than a predetermined value.

[0076] Here, "low-load operation" refers to operation in which a substitute value indicating the load during air-conditioning operation satisfies a predetermined condition. Unlike thermo-off, which stops the compressor 21 and stops the circulation of the refrigerant, low-load operation is performed before thermo-off. In addition, low-load operation does not include the start-up of the compressor 21 that starts operation, but is performed when the refrigerant state is stable after startup (operation that continues for a predetermined time).

[0077] For example, the substitute value is the rated capacity of the air conditioning device 1, and the specified condition is 45% or less of the rated capacity. In other words, low-load operation occurs when the capacity is 45% or less of the rated capacity. The rated capacity is a value equivalent to the "nominal capacity" listed in the product catalog or instruction manual.

[0078] Also, for example, the substitute value during cooling operation is the difference between the set temperature and the room temperature, and the specified condition is that this difference (set temperature Trs - room temperature Tr during heating operation, and room temperature Tr - set temperature Trs during cooling operation) is 0.5°C or less (including negative values). In other words, when the room temperature approaches the set temperature and the difference between the set temperature and the room temperature becomes 0.5°C or less, low-load operation is initiated.

[0079] Also, for example, the substitute value during dehumidification operation is the difference between the set humidity and the indoor humidity, and the specified condition is that this difference is 0% or less. In other words, when the indoor humidity approaches the set humidity and the difference between the set humidity and the indoor humidity becomes 0% or less, low load operation is performed.

[0080] The indoor control unit 30 controls the rotation speed of the indoor fan 32 during low-load operation to be lower than the rotation speed of the indoor fan 32 during normal operation, in which the load of air conditioning operation is higher than that of low-load operation. In this embodiment, during low-load operation, the airflow of the indoor fan 32 is controlled to an airflow LL that cannot be set by the resident using the remote control 60.

[0081] (4-1) Control of opening and closing parts during heating operation Next, a specific example of control of the opening / closing member 49 of the indoor control unit 30 during heating operation will be described with reference to Fig. 5. Fig. 5 shows control by the indoor control unit 30 during low load operation. In Fig. 5, the lower limit of the condensation temperature Tc that does not give a feeling of cool air during heating operation is set to a first threshold value X (cold air line). Here, the target condensation temperature Tcs is set to be equal to or higher than the first threshold value X. Note that the condensation degree Tc is calculated from the discharge pressure detected by the discharge pressure sensor 29a, as described above.

[0082] 5, at time t0, the indoor temperature Tr is rising. When the difference (Trs-Tr) between the indoor temperature Tr and the set temperature Trs (the target indoor temperature set by the remote control operation unit 64) becomes small, the target condensation temperature Tcs becomes low and the rotation speed of the compressor 21 becomes low. Then, the condensation temperature Tc of the refrigerant becomes low so as to approach the target condensation temperature Tcs.

[0083] After that, at time t1, when the target condensing temperature Tcs reaches the first threshold value X, the target condensing temperature Tcs is maintained at the first threshold value X so as not to give a feeling of cold air. Since the rotation speed of the compressor 21 is further reduced, the condensing temperature Tc of the refrigerant decreases.

[0084] At time t2, when the condensation temperature Tc of the refrigerant reaches the first threshold value X, the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46. Here, at time t2, the condensation temperature Tc of the refrigerant in the indoor heat exchanger 31 drops to the first threshold value X, and the indoor temperature Tr continues to rise, so the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46.

[0085] Here, the indoor control unit 30 performs independent wind direction control, which adjusts the wind direction of the conditioned air blown out from the four side air outlets 46a of the air outlets 46 independently by controlling each opening / closing member 49 to change its rotation state, and coordinated wind direction control, which adjusts the wind direction of the conditioned air blown out from the four side air outlets 46a of the air outlets 46 independently by controlling each opening / closing member 49 to change its rotation state. At time t2, in the independent wind direction control, the indoor control unit 30 rotates the opening / closing member 49 so as to close at least one of the multiple side air outlets 46a during low load operation. As a result, the indoor fan 32 on the side of the opening / closing member 49 that closes the side air outlet 46a runs idle, and conditioned air is not blown out from the closed side air outlet 46a. Therefore, the indoor fan 32 can reduce the volume of conditioned air blown out from all the air outlets 46 while maintaining the rotation speed.

[0086] In this embodiment, the indoor control unit 30 controls so that at least one of the side air outlets 46a located in the direction facing the direction where no person is present is closed by the opening / closing member 49. To perform such control, the indoor control unit 30 determines which opening / closing member 49 to close according to the position of the person detected by the human detection sensor 36. In detail, the indoor control unit 30 controls the attitude of the opening / closing member 49 so that the side air outlets 46a facing the direction where the person is present detected by the human detection sensor 36 are kept open, and the side air outlets 46a facing the direction where the person is not present are closed. For example, when the conditioned air blown out from one of the four side air outlets 46a is facing the direction where no person is present, the indoor control unit 30 rotates the opening / closing member 49 so as to reduce the amount of conditioned air blown out from that side air outlet 46a (preferably no conditioned air is blown out).

[0087] By performing such control, the amount of heat dissipated in the indoor heat exchanger 31 is reduced, and the condensation temperature Tc of the refrigerant can be increased. This makes it possible to prevent the temperature of the conditioned air blown out from the side air outlet 46a from decreasing. In addition, it is possible to continue low-load operation with the rotation speed of the compressor 21 further reduced without turning off the thermostat.

[0088] If low-load operation continues after time t2, the condensation temperature Tc of the refrigerant will drop further. When the condensation temperature reaches the first threshold value X again at time t3, the indoor control unit 30 controls the attitude of the multiple opening / closing members 49 so that the opening / closing members 49 close at least one of the air outlets 46 that was closed at time t2 and the other air outlets 46.

[0089] For example, at time t2, one of the four side air outlets 46a is closed by the opening / closing member 49, and three side air outlets 46a are opened. Then, at time t3, one of the three side air outlets 46a opened at time t2 is closed by the opening / closing member 49. As a result, after time t3 has elapsed, the thermostat is not turned off, and low-load operation can be continued with the rotation speed of the compressor 21 further reduced.

[0090] (4-2) Control of opening and closing components during cooling operation Next, a specific example of control of the opening / closing member 49 of the indoor control unit 30 during cooling operation will be described with reference to Fig. 6. Fig. 6 shows control by the indoor control unit 30 during low load operation. In Fig. 6, the lower limit of the evaporation temperature that does not give a feeling of warm air during cooling operation is set to a second threshold value Y (warm air line). Here, the target evaporation temperature Tecs is set to be equal to or lower than the second threshold value Y.

[0091] The second threshold value Y in this embodiment is the dew point temperature of the indoor air. The dew point temperature is calculated from the indoor temperature Tr detected by the indoor temperature sensor 34 and the indoor humidity Hr detected by the indoor humidity sensor 35. The evaporation temperature Te is calculated from the suction pressure detected by the suction pressure sensor 28a, as described above.

[0092] 6, at time t0, the indoor temperature Tr is decreasing. When the difference (Trs-Tr) between the indoor temperature Tr and the set temperature Trs (the target indoor temperature set by the remote control operation unit 64) and the indoor temperature Tr becomes small, the target evaporation temperature Tecs becomes high and the rotation speed of the compressor 21 becomes low. Then, the evaporation temperature Te of the refrigerant becomes high so as to approach the target evaporation temperature Tecs.

[0093] After that, at time t1, when the target evaporation temperature Tecs reaches the second threshold value Y, the target evaporation temperature Tecs is maintained at the second threshold value Y so as not to give a feeling of warm air. Since the rotation speed of the compressor 21 is further reduced, the evaporation temperature Te of the refrigerant increases.

[0094] At time t2, when the evaporation temperature Te of the refrigerant reaches the second threshold Y, the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46. Here, at time t2, the evaporation temperature Te of the refrigerant in the indoor heat exchanger 31 rises to the second threshold Y and the indoor temperature Tr continues to fall, so the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46.

[0095] Specifically, similarly to the heating operation, in independent air direction control, the indoor control unit 30 rotates the opening / closing member 49 so as to close at least one of the multiple air outlets 46. Also, the indoor control unit 30 controls the opening / closing member 49 to close at least one of the air outlets 46 located in a direction facing a direction in which no people are present.

[0096] By performing such control, the amount of heat absorbed in the indoor heat exchanger 31 is reduced, and the evaporation temperature Te of the refrigerant can be lowered. This makes it possible to prevent the temperature of the conditioned air blown out from the air outlet 46a from becoming too high. In addition, it is possible to continue low-load operation with the rotation speed of the compressor 21 further reduced without turning off the thermostat.

[0097] As low-load operation continues, the rotation speed of the compressor 21 becomes even smaller, so that the evaporation temperature Te of the refrigerant falls further. When the evaporation temperature reaches the second threshold value Y again at time t3, the indoor control unit 30 controls the attitude of the multiple opening / closing members 49 so that the opening / closing member 49 closes at least one of the air outlets 46 that was closed at time t2 and the other air outlets 46. This makes it possible to continue low-load operation with the rotation speed of the compressor 21 further reduced without thermo-off after time t3 has elapsed.

[0098] (4-3) Control of opening and closing parts during dehumidification operation The control of the opening / closing member 49 during dehumidification operation is basically the same as the control of the opening / closing member 49 during cooling operation, except that the target evaporation temperature Teds during dehumidification operation is set to a value lower than the target evaporation temperature Tecs during cooling operation.

[0099] (5) Control method of opening and closing members The control of the opening and closing components was mentioned in (4) above, but to summarize, it involves the following steps:

[0100] 7, the compressor 21 is started and normal operation is performed under a load higher than that during low-load operation (step S1). After that, when the load of the air conditioning operation falls below a predetermined level, low-load operation is performed (step S2).

[0101] Next, the indoor control unit 30 determines whether or not the suppression of the draft feeling is sufficient (step S3). In this embodiment, in step S3, it is determined that the suppression of the draft feeling is sufficient if the condensation temperature Tc of the refrigerant in the indoor heat exchanger 31 has not dropped to the first threshold value X during heating operation, and if the evaporation temperature Te of the refrigerant in the indoor heat exchanger 31 has not risen to the second threshold value Y during cooling operation or dehumidification operation. If it is determined in step S3 that the suppression of the draft feeling is sufficient, the air outlet 46 is maintained in an open / closed state, and low-load operation is continued (step S2).

[0102] On the other hand, in step S3, if the condensation temperature Tc falls to the first threshold value X during heating operation, or if the evaporation temperature Te rises to the second threshold value Y during cooling operation or dehumidification operation, it is determined that the suppression of the draft feeling is insufficient. If it is determined in step S3 that the suppression of the draft feeling is insufficient, the process proceeds to step S4.

[0103] In step S4, the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46. This makes it possible to prevent conditioned air with a cool feeling from being blown out from the air outlet 46 during heating operation, and to prevent conditioned air with a warm feeling from being blown out from the air outlet 46 during cooling operation or dehumidification operation. Therefore, the indoor unit 3 continues low-load operation (step S2).

[0104] In step S3 after at least one air outlet 46 is closed by the opening / closing member 49, if the condensation temperature Tc falls again to the first threshold value X during heating operation, or if the evaporation temperature Te rises again to the second threshold value Y during cooling operation or dehumidification operation, the indoor control unit 30 controls the attitude of the opening / closing member 49 so that the air outlet 46 closed by the opening / closing member 49 and at least one other air outlet 46 are closed by another opening / closing member 49. This makes it possible to suppress conditioned air with a cool air feel from being blown out from the air outlet 46 during heating operation, and to suppress conditioned air with a warm air feel from being blown out from the air outlet 46 during cooling operation or dehumidification operation. For this reason, the indoor unit 3 further continues low-load operation (step S2).

[0105] In addition, when it is determined in step S3 that the draft feeling is not sufficiently suppressed, if all of the opening / closing members 49 are closing the air outlet 46, the control device 6 controls the air conditioning device 1 to enter thermo-off operation or to stop operation.

[0106] (6) Features (6-1) In recent years, due to improvements in insulation performance, during air conditioning operation, the indoor temperature approaches the set temperature, and low-load operation with the air conditioning load below a predetermined level may be performed. However, during this low-load operation, there is a problem that the occupants feel a sense of draft. After focusing on this problem and conducting extensive research, the present inventors came up with the indoor unit 3 of the air conditioner 1 of this embodiment.

[0107] The indoor unit 3 of the air conditioner 1 according to this embodiment is an indoor unit of an air conditioner that performs air conditioning operation, and includes an indoor heat exchanger 31, a casing 41, multiple opening / closing members 49, and an indoor control unit 30. The indoor heat exchanger 31 exchanges heat between indoor air and a refrigerant to generate conditioned air. The casing 41 is formed with multiple air outlets 46, 46a, 46b that blow out the conditioned air. The multiple opening / closing members 49 open and close the multiple air outlets 46a. The indoor control unit 30 controls the attitude of the opening / closing member 49. The indoor control unit 30 controls the attitude of the opening / closing member 49 so as to close at least one of the multiple air outlets 46a during low-load operation in which the load of the air conditioning operation is equal to or lower than a predetermined load.

[0108] In this embodiment, during low-load operation in which the air conditioning load is lower than in normal operation, the attitude of the opening / closing member 49 is controlled so as to close at least one of the air outlets 46a. This can reduce the amount of heat exchanged between the refrigerant and the indoor air in the indoor heat exchanger 31. Therefore, it is possible to suppress the temperature of the conditioned air blown out from the air outlet 46 from decreasing during heating operation, and to suppress the temperature of the conditioned air blown out from the air outlet from increasing during cooling operation or dehumidification operation. Therefore, it is possible to suppress the occupant from feeling cold air during heating operation of the air conditioner 1, and to suppress the occupant from feeling warm air during cooling operation or dehumidification operation. Therefore, the indoor unit 3 can suppress the feeling of a draft.

[0109] (6-2) Here, when the condensation temperature Tc of the refrigerant in the indoor heat exchanger 31 drops to the first threshold value X during heating operation (times t2 and t3 in FIG. 5), the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46a.

[0110] When the condensation temperature Tc of the refrigerant drops during heating operation, the temperature of the conditioned air that has exchanged heat with the refrigerant in the indoor heat exchanger 31 drops. For this reason, the first threshold value X is set to a lower limit value that does not give a feeling of cool air during heating operation, and when the condensation temperature Tc drops to the first threshold value, control is performed so that at least one of the air outlets 46a is closed by the opening / closing member 49. This causes the condensation temperature Tc to rise, making it possible to prevent the conditioned air blown out from the air outlet 46a from dropping to a temperature that gives a feeling of cool air during heating operation.

[0111] Moreover, the condensation temperature Tc can be controlled so as to prevent thermo-off by controlling the attitude of the opening / closing member 49. For this reason, the indoor unit 3 of the present embodiment can reduce the frequency with which thermo-off occurs during low load operation.

[0112] (6-3) In addition to the above, here, during heating operation, when the condensation temperature Tc of the refrigerant in the indoor heat exchanger 31 drops to the first threshold value X and the temperature of the indoor air continues to rise (time t2 in Figure 5), the indoor control unit 30 controls the posture of the opening / closing member 49 to close at least one of the multiple air outlets 46a.

[0113] In this way, when the indoor air temperature rises during heating operation, the heating load becomes lower, and so the temperature of the conditioned air that has undergone heat exchange in the indoor heat exchanger 31 is likely to drop. For this reason, when the condensation temperature Tc falls during heating operation and the indoor air temperature rises, the indoor control unit 30 can close at least one of the air outlets 46a with the opening / closing member 49, thereby enhancing the effect of suppressing the feeling of cold air.

[0114] (6-4) Here, the indoor control unit 30 controls the posture of the opening / closing member 49 to close at least one of the multiple air outlets 46a when the evaporation temperature Te of the refrigerant in the indoor heat exchanger 31 rises to a second threshold value Y (times t2 and t3 in Figure 6) during cooling operation or dehumidification operation.

[0115] When the evaporation temperature Te of the refrigerant drops during cooling or dehumidifying operation, the temperature of the conditioned air that has undergone heat exchange in the indoor heat exchanger 31 rises. For this reason, here, the second threshold value Y is set to an upper limit value that does not give a feeling of warm air during cooling or dehumidifying operation, and the attitude of the opening / closing member 49 is controlled to close at least one of the air outlets 46a when the evaporation temperature Te rises to the second threshold value Y. This makes it possible to prevent the conditioned air blown out from the air outlet 46a from rising to a temperature that gives a feeling of warm air during cooling or dehumidifying operation.

[0116] Moreover, the evaporation temperature Te can be controlled so as to prevent thermo-off by controlling the attitude of the opening / closing member 49. For this reason, the indoor unit 3 of the present embodiment can reduce the frequency with which thermo-off occurs during low load operation.

[0117] (6-5) In addition to the above, during cooling operation or dehumidification operation, when the evaporation temperature Te of the refrigerant in the indoor heat exchanger 31 rises to the second threshold value Y and the indoor air temperature continues to decrease (time t2 in Figure 6), the posture of the opening / closing member 49 is controlled to close at least one of the multiple air outlets 46a.

[0118] In this way, when the temperature or humidity of the indoor air decreases during cooling operation or dehumidification operation, the cooling load or dehumidification load becomes lower, so that the temperature of the conditioned air that has undergone heat exchange in the indoor heat exchanger 31 is likely to rise. For this reason, when the evaporation temperature Te rises and the temperature of the indoor air drops during cooling operation or dehumidification operation, the indoor control unit 30 can close at least one of the air outlets 46a with the opening / closing member 49, thereby enhancing the effect of suppressing the feeling of warm air.

[0119] (6-6) Here, the second threshold value Y is the dew point temperature of the indoor air. In other words, when the evaporation temperature Te of the refrigerant in the indoor heat exchanger 31 rises to the dew point temperature during cooling operation or dehumidification operation, the indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46a.

[0120] During cooling operation, when the evaporation temperature Te of the refrigerant rises to the dew point temperature of the indoor air, the indoor heat exchanger 31 no longer cools the indoor air to the refrigerant. For this reason, here, the dew point temperature is set as the second threshold value Y so that the indoor air is cooled to the refrigerant in the indoor heat exchanger 31. This makes it possible to perform cooling operation or dehumidification operation during low load operation while maintaining the refrigerant at or below the dew point temperature. Therefore, it is possible to realize an indoor unit that suppresses the occupant from feeling warm air during cooling operation or dehumidification operation.

[0121] In addition, during low-load operation of cooling and dehumidification, there is a problem that odor occurs due to the absence of condensation. In this embodiment, when the evaporation temperature Te rises to the dew point temperature, at least one of the air outlets 46a is closed by the opening and closing member 49, so that the evaporation temperature Te does not exceed the dew point temperature. This makes it possible to suppress unpleasant odors caused by low-load operation.

[0122] (6-7) Here, three or more air outlets 46a are formed in the casing 41. The indoor control unit 30 controls the attitudes of the multiple opening / closing members 49 so that, after closing at least one of the multiple air outlets 46a with the opening / closing member 49, the opening / closing member 49 closes at least one of the other air outlets 46a.

[0123] In this way, the indoor control unit 30 of this embodiment can control the air conditioner to open the third air outlet 46a and close the first air outlet 46a with the opening / closing member 49, and then, when the draft feeling is not sufficiently suppressed, to open the third air outlet and close the second air outlet 46a with the opening / closing member 49.

[0124] In addition, by setting the timing at which the multiple opening / closing members 49 close the three or more air outlets 46a to two or more times, the frequency at which the thermostat switches off during low load operation can be further reduced.

[0125] (6-8) Here, the indoor control unit 30 controls the opening / closing member 49 to close at least one of the air outlets 46a located in a direction facing a direction in which no people are present.

[0126] After at least one of the air outlets 46a is closed by the opening / closing member 49, conditioned air with a reduced draft feeling can be blown out. Therefore, comfort can be improved by supplying conditioned air with a reduced draft feeling in the direction where people are present.

[0127] (6-9) Here, one opening / closing member 49 opens and closes one air outlet 46a. In other words, the first opening / closing member 49 opens and closes the first air outlet 46a, and the second opening / closing member 49 opens and closes the second air outlet 46a. This makes it easy to control the closing of the air outlet 46a by the opening / closing member 49.

[0128] (7) Variations (7-1) Variation 1 In the above embodiment, among the air outlets 46, the opening / closing members 49 are arranged at the side air outlets 46a, and no opening / closing member 49 is arranged at the corner air outlets 46b, but this is not limited thereto. For example, in the above embodiment, one opening / closing member 49 is arranged at one side air outlet 46a, but two or more opening / closing members may be arranged at one side air outlet 46a. Also, one or more opening / closing members 49 may be arranged at the corner air outlet 46b.

[0129] (7-2) Variation 2 In the above embodiment, the attitude of the opening / closing member 49 is controlled to close at least one of the multiple air outlets 46 when the condensation temperature Tc falls to the first threshold value X during heating operation and when the evaporation temperature Te rises to the second threshold value Y during cooling operation or dehumidification operation, but this is not limited to the above. The indoor control unit 30 controls the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46 at any timing between the start and end of low-load operation. For this reason, the indoor control unit 30 may control the attitude of the opening / closing member 49 to close at least one of the multiple air outlets 46 before the condensation temperature Tc falls to the first threshold value X during heating operation and / or before the evaporation temperature Te rises to the second threshold value Y during cooling operation or dehumidification operation.

[0130] In this modified example, when the target condensation temperature Tcs falls to a first threshold value X during heating operation, and when the target evaporation temperatures Tecs, Teds rise to a second threshold value Y during cooling operation or dehumidification operation, the posture of the opening / closing member 49 is controlled to close at least one of the multiple air outlets 46.

[0131] (7-3) Variation 3 In the above embodiment, the indoor control unit 30 closes one side air outlet 46a with the opening / closing member 49, continues low-load operation, and then closes another side air outlet 46a with another opening / closing member 49 when the condensation temperature Tc drops to the first threshold value X during heating operation, or when the evaporation temperature Te rises to the second threshold value Y during cooling operation or dehumidification operation, but this is not limited to the above. In this modified example, the indoor control unit 30 closes one side air outlet 46a with the opening / closing member 49, continues low-load operation, and then closes another side air outlet 46a with another opening / closing member 49 when the room temperature rises during heating operation (before the condensation temperature Tc drops to the first threshold value X) or when the room temperature drops during cooling operation or dehumidification operation (before the evaporation temperature Te rises to the second threshold value Y).

[0132] (7-4) Variation 4 In the embodiment described above, the indoor unit 3 is equipped with the human detection sensor 36, but this is not limited to this. The indoor unit 3 of this modified example does not include the human detection sensor 36. In this modified example, even if the human detection sensor 36 is not provided, the indoor control unit 30 closes the air outlet 46 that blows out conditioned air in a direction estimated to be a direction in which no people are present, using the opening and closing member 49, during low load operation.

[0133] (7-5) Variation 5 In the embodiment described above, the indoor control unit 30 controls at least one of the air outlets located in a direction facing a direction in which no one is present to be closed by the opening and closing member 49, but is not limited to this. The indoor control unit 30 can appropriately select the air outlet 46 to close during low-load operation.

[0134] (7-6) Variation 6 In the above-described embodiment, the state variable of the control target in the capacity control of the compressor 21 during cooling operation and dehumidification operation is the evaporation temperature Te, but this is not limited to this. In this modified example, the state variable of the control target in the capacity control is the evaporation pressure. In this case, a target evaporation pressure equivalent to the target evaporation temperatures Teds and Tecs is used as the control target value. Note that using the evaporation pressure and the target evaporation pressure in this capacity control is the same as using the evaporation temperature Te and the target evaporation temperatures Teds and Tecs.

[0135] (7-7) Variation 7 In the above-described embodiment, the state variable of the control object in the capacity control of the compressor 21 during heating operation is the condensation temperature Tc, but this is not limited to this. In this modified example, the state variable of the control object in the capacity control is the condensation pressure. In this case, a target condensation pressure equivalent to the target condensation temperature Tcs is used as the control target value. Note that using the condensation pressure and the target condensation pressure in this capacity control is the same as using the condensation temperature Tc and the target condensation temperature Tcs.

[0136] (7-8) Variation 8 In the above-described embodiment, the indoor unit 3 of the air conditioning device 1 that performs cooling operation, dehumidification operation, and heating operation has been described as an example, but the indoor unit of the present disclosure is not limited to this as long as it performs at least one of heating operation, cooling operation, and dehumidification operation.

[0137] (7-9) Variation 9 In the above-described embodiment, a ceiling-embedded indoor unit has been described as an example, but the indoor unit of the present disclosure is not limited to this. The indoor unit of the present disclosure may be of any type, such as a wall-mounted type or a floor-standing type.

[0138] (7-10) Variation 10 In the above-described embodiment, an air conditioner 1 including one indoor unit 3 has been described as an example, but the air conditioner of the present disclosure is not limited to this. The air conditioner of the present disclosure can also be applied to a multi-type air conditioner including multiple indoor units 3.

[0139] Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure described in the claims. [Explanation of symbols]

[0140] 1: Air conditioning equipment 2:Outdoor unit 3: Indoor unit 30: Indoor control unit (control unit) 41: Casing 45: Intake port 46,46a,46b: Air outlet 49: Opening and closing parts X: First threshold Y: Second threshold [Prior art documents] [Patent documents]

[0141] [Patent Document 1] JP 2011-99613 A

Claims

1. An indoor unit of an air conditioner that performs air conditioning operation, A heat exchanger (31) that exchanges heat between indoor air and a refrigerant to generate conditioned air; a casing (41) in which a plurality of air outlets (46, 46a, 46b) for blowing out the conditioned air are formed; A plurality of opening / closing members (49) for opening and closing the plurality of air outlets (46a); A control unit (30) that controls the attitude of the opening / closing member; Equipped with the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets during low-load operation where the load of the air conditioning operation is equal to or lower than a predetermined value, The control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets when a condensation temperature of the refrigerant in the heat exchanger falls to a first threshold value and a temperature of the indoor air continues to rise during a heating operation. An indoor unit (3) of an air conditioning device (1).

2. An indoor unit of an air conditioner performing air conditioning operation, A heat exchanger (31) that exchanges heat between indoor air and a refrigerant to generate conditioned air; a casing (41) in which a plurality of air outlets (46, 46a, 46b) for blowing out the conditioned air are formed; A plurality of opening / closing members (49) for opening and closing the plurality of air outlets (46a); A control unit (30) that controls the attitude of the opening / closing member; Equipped with the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets during low-load operation where the load of the air conditioning operation is equal to or lower than a predetermined value, the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets when an evaporation temperature of the refrigerant in the heat exchanger rises to a second threshold value and a temperature of the indoor air continues to decrease during a cooling operation or a dehumidification operation. An indoor unit (3) of an air conditioning device (1).

3. The second threshold value is a dew point temperature of indoor air. An indoor unit for an air conditioner according to claim 2.

4. An indoor unit of an air conditioning apparatus performing air conditioning operation, A heat exchanger (31) that exchanges heat between indoor air and a refrigerant to generate conditioned air; a casing (41) in which a plurality of air outlets (46, 46a, 46b) for blowing out the conditioned air are formed; A plurality of opening / closing members (49) for opening and closing the plurality of air outlets (46a); A control unit (30) that controls the attitude of the opening / closing member; Equipped with the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets during low-load operation where the load of the air conditioning operation is equal to or lower than a predetermined value, The control unit controls the opening / closing member to close at least one of the air outlets located in a direction facing a direction in which no person is present. An indoor unit (3) of an air conditioning device (1).

5. The control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets when a condensation temperature of the refrigerant in the heat exchanger falls to a first threshold during a heating operation. An indoor unit for an air conditioner according to claim 4.

6. the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets when a condensation temperature of the refrigerant in the heat exchanger falls to the first threshold value and a temperature of the indoor air continues to rise during a heating operation. An indoor unit for an air conditioner according to claim 5.

7. the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets when an evaporation temperature of the refrigerant in the heat exchanger rises to a second threshold during a cooling operation or a dehumidification operation. An indoor unit for an air conditioner according to claim 4.

8. the control unit controls the attitude of the opening / closing member to close at least one of the plurality of air outlets when an evaporation temperature of the refrigerant in the heat exchanger rises to the second threshold value and a temperature of the indoor air continues to decrease during a cooling operation or a dehumidification operation. An indoor unit for an air conditioner according to claim 7.

9. The casing is formed with three or more of the air outlets, The control unit controls the attitudes of the plurality of opening / closing members so that, after closing at least one of the plurality of air outlets with the opening / closing member, at least one of the other air outlets is closed with the opening / closing member. An indoor unit for an air conditioner according to any one of claims 1 to 8.

10. One of the opening / closing members opens and closes one of the air outlets. An indoor unit for an air conditioner according to any one of claims 1 to 9.

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