TW202232032A - air conditioner - Google Patents

Abstract

Provided is an air conditioner which puts a heat exchanger into a clean state. This air conditioner (100) comprises a compressor (11), an outdoor heat exchanger (12), an expansion valve (14), and an indoor heat exchanger (15), and also comprises a control unit which performs a process to cause the heat exchanger, i.e., the indoor heat exchanger (15) or the outdoor heat exchanger (12), to function as an evaporator, and to freeze or condense the heat exchanger, wherein the control unit performs control to raise the temperature of the heat exchanger prior to the aforementioned process.

Description

air conditioner

The present invention relates to an air conditioner.

As a technique for cleaning the heat exchanger of an air conditioner, for example, the technique described in Patent Document 1 is known. That is, Patent Document 1 describes that the control unit performs an operation for lowering the temperature of the heat exchanger and performs a freezing operation for adhering frost or ice to the surfaces of the fins. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2018-189270.

[The problem to be solved by the invention]

In addition, mist-like oil suspended in the air may adhere to a heat exchanger (for example, an indoor heat exchanger) during the operation of the air conditioner. Then, with the passage of time, the degree of oxidation of the oil on the surface of the heat exchanger is increased, and the oil is fixed to the heat exchanger. For such a heat exchanger, for example, even if the technology described in Patent Document 1 is used for cleaning, there is a possibility that oil leaked from cleaning may remain in the heat exchanger. That is, the technique described in Patent Document 1 still has room for improvement in bringing the heat exchanger into a clean state.

Therefore, the subject of this invention is to provide the air conditioner which makes a heat exchanger into a clean state. [means to solve the problem]

In order to solve the above-mentioned problems, an air conditioner of the present invention includes a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger, and further includes a control unit that controls the heat of the indoor heat exchanger or the outdoor heat exchanger. The exchanger functions as an evaporator and performs a process of freezing or dew condensation of the heat exchanger, and the control unit performs control of increasing the temperature of the heat exchanger before the process. [Inventive effect]

According to the present invention, it is possible to provide an air conditioner in which a heat exchanger is brought into a clean state.

"First Embodiment" <Structure of Air Conditioner> FIG. 1 is a configuration diagram of an air conditioner 100 according to the first embodiment. In addition, the solid line arrow in FIG. 1 shows the flow of the refrigerant|coolant at the time of heating operation. On the other hand, the broken-line arrows in FIG. 1 indicate the flow of the refrigerant during the cooling operation. The air conditioner 100 is a device that performs air conditioning such as cooling operation and heating operation. As shown in FIG. 1 , the air conditioner 100 includes a compressor 11 , an outdoor heat exchanger 12 , an outdoor fan 13 , and an expansion valve 14 . Moreover, the air conditioner 100 is provided with the indoor heat exchanger 15 (heat exchanger), the indoor fan 16 (fan), and the four-way valve 17 in addition to the said structure.

The compressor 11 is a device that compresses a low-temperature, low-pressure gas refrigerant and discharges it as a high-temperature, high-pressure gas refrigerant, and includes a compressor motor 11a as a drive source. As such a compressor 11, a scroll compressor, a rotary compressor, or the like can be used. In addition, although illustration is abbreviate|omitted in FIG. 1, the accumulator 9 (refer FIG. 3) is connected to the suction side of the compressor 11, and this accumulator 9 is used for gas-liquid separation of a refrigerant|coolant.

The outdoor heat exchanger 12 is a heat exchanger that exchanges heat between the refrigerant flowing through the heat transfer tubes 12b (see FIG. 3 ) of the outdoor heat exchanger 12 and the outside air sent by the outdoor fan 13 . The outdoor fan 13 is a fan that sends outside air to the outdoor heat exchanger 12 . The outdoor fan 13 includes an outdoor fan motor 13a as a drive source, and is provided in the vicinity of the outdoor heat exchanger 12 . The expansion valve 14 is a valve that decompresses the refrigerant condensed by the "condenser" (one of the outdoor heat exchanger 12 and the indoor heat exchanger 15). Further, the refrigerant decompressed by the expansion valve 14 is guided to the "evaporator" (the other of the outdoor heat exchanger 12 and the indoor heat exchanger 15).

The indoor heat exchanger 15 is heat exchanged between the refrigerant flowing through the heat transfer tubes 15b (see FIG. 2 ) of the indoor heat exchanger 15 and the indoor air (air-conditioning room air) sent by the indoor fan 16 . exchanger. The indoor fan 16 is a fan that sends indoor air to the indoor heat exchanger 15 . The indoor fan 16 is provided with the indoor fan motor 16a (refer FIG. 4) as a drive source, and is provided in the vicinity of the indoor heat exchanger 15. As shown in FIG.

The four-way valve 17 is a valve that switches the flow path of the refrigerant according to the operation mode of the air conditioner 100 . In addition, the air conditioner 100 is configured to include a refrigerant circuit 10 including a compressor 11 , an outdoor heat exchanger 12 , an expansion valve 14 , and an indoor heat exchanger 15 connected by a four-way valve 17 .

For example, during the cooling operation (refer to the dashed arrow in FIG. 1 ), in the refrigerant circuit 10 , the refrigerant passes through the compressor 11 , the outdoor heat exchanger 12 (condenser), the expansion valve 14 , and the indoor heat exchanger 15 (evaporation) in this order. device) to cycle. On the other hand, during the heating operation (refer to the solid arrows in FIG. 1 ), in the refrigerant circuit 10 , the refrigerant passes through the compressor 11 , the indoor heat exchanger 15 (condenser), the expansion valve 14 , and the outdoor heat exchanger in this order. 12 (evaporator) to cycle.

In addition, in the example of FIG. 1 , the compressor 11 , the outdoor heat exchanger 12 , the outdoor fan 13 , the expansion valve 14 , and the four-way valve 17 are provided in the outdoor unit 30 . On the other hand, the indoor heat exchanger 15 and the indoor fan 16 are installed in the indoor unit 20 .

FIG. 2 is a vertical cross-sectional view of the indoor unit 20 . As shown in FIG. 2 , the indoor unit 20 includes, in addition to the indoor heat exchanger 15 and the indoor fan 16, a drain pan 18, a casing 19, and filters 21a and 21b. In addition, the indoor unit 20 includes a front panel 22 , a left-right air direction plate 23 , and an up-down air direction plate 24 .

The indoor heat exchanger 15 includes: a plurality of fins 15a; and a plurality of heat transfer tubes 15b passing through the fins 15a. Described from another viewpoint, the indoor heat exchanger 15 includes a front side indoor heat exchanger 15c arranged on the front side of the indoor fan 16 and a rear side indoor heat exchanger 15d arranged on the rear side of the indoor fan 16 . In the example of FIG. 2, the upper end part of the front side indoor heat exchanger 15c and the upper end part of the rear side indoor heat exchanger 15d are connected in an inverted V shape in a vertical cross-sectional view. In addition, the structure of the indoor heat exchanger 15 shown in FIG. 2 is an illustration only, and it is not limited to this.

The indoor fan 16 is, for example, a cylindrical cross-flow fan, and is arranged near the indoor heat exchanger 15 . The indoor fan 16 includes a plurality of fan blades 16b and an annular partition plate 16c on which the fan blades 16b are provided, in addition to the aforementioned indoor fan motor 16a (see FIG. 4 ). The drain pan 18 receives the dew condensation water of the indoor heat exchanger 15 and is disposed on the lower side of the indoor heat exchanger 15 . The casing 19 accommodates the indoor heat exchanger 15, the indoor fan 16, and the like.

The filters 21a and 21b are arranged in the vicinity of the indoor heat exchanger 15 by collecting dust that has progressed toward the indoor heat exchanger 15 from the air. One of the filters 21 a is arranged on the front side of the indoor heat exchanger 15 , and the other filter 21 b is arranged on the upper side of the indoor heat exchanger 15 .

The front panel 22 is a panel provided so as to cover the filter 21a on the front side, and is rotatable toward the front side with the lower end as the axis. In addition, the front panel 22 may have a structure that does not rotate. The left-right wind direction plate 23 is a plate-shaped member which adjusts the wind direction of the left-right direction of the air blown out from the indoor fan 16 . The left-right wind direction board 23 is arrange|positioned in the blowing air path 26, and can be rotated in the left-right direction by the motor 34 (refer FIG. 4) for left-right wind direction boards. The up-down wind direction board 24 is a plate-shaped member which adjusts the wind direction of the up-down direction of the air blown out from the indoor fan 16 . The up-and-down wind direction board 24 is arrange|positioned at the air outlet 27, and can be rotated in the up-down direction by the motor 35 (refer FIG. 4) for up-and-down wind direction boards.

The air sucked in through the air intake ports 25 a and 25 b exchanges heat with the refrigerant flowing through the heat transfer tubes 15 b of the indoor heat exchanger 15 , and the heat-exchanged air is guided to the blowing air passage 26 . Then, the air circulating in the blowing air passage 26 is guided in a predetermined direction by the left and right air direction plates 23 and the up and down air direction plates 24 , and is blown out to the air-conditioning room through the air outlet 27 .

Moreover, most of the dust which advances toward the air suction ports 25a and 25b with the flow of air is collected by the filters 21a and 21b. However, there is a possibility that fine dust may pass through the filters 21a and 21b and adhere to the indoor heat exchanger 15 . In addition, oil fume (vapor of oil) suspended in the air of the air-conditioned room also permeates through the filters 21a and 21b and adheres to the indoor heat exchanger 15 . Then, as time elapses, the degree of oxidation of the oil on the surface of the indoor heat exchanger 15 increases, and the oil is fixed and adhered to the indoor heat exchanger 15 . Therefore, it is desirable to periodically clean the indoor heat exchanger 15, but there is a problem that oil is difficult to wash off.

Therefore, in the first embodiment, the temperature of the indoor heat exchanger 15 is raised, the oil on the surface of the indoor heat exchanger 15 is softened (or liquefied, fluidized), and then the freezing and thawing of the indoor heat exchanger 15 are sequentially performed. , so that the oil and dust on the surface of the indoor heat exchanger 15 can be washed away together. Such a series of processing including heating, freezing, and thawing of the indoor heat exchanger 15 is referred to as "cleaning operation".

3 is a perspective view of a state in which the side plate and the top plate of the casing 31 of the outdoor unit 30 are removed. In addition, in FIG. 3, illustration of the expansion valve 14 (refer FIG. 1) and the four-way valve 17 (refer FIG. 1) is abbreviate|omitted. As shown in FIG. 3 , the casing 31 of the outdoor unit 30 is provided with the compressor 11 , the outdoor heat exchanger 12 , and the outdoor fan 13 , and an electrical component box 32 is also provided. In the example of FIG. 3 , the outdoor heat exchanger 12 having an L-shape in plan view is provided on the bottom plate 31 a of the casing 31 . The outdoor heat exchanger 12 includes a plurality of fins 12a arranged at predetermined intervals, and a plurality of heat transfer tubes 12b penetrating the fins 12a. In addition, in the example of FIG. 3, as the outdoor fan 13, a paddle fan is used.

FIG. 4 is a functional block diagram of the air conditioner 100 . The indoor unit 20 shown in FIG. 4 includes, in addition to the aforementioned structures, a remote control transceiver 28, an indoor temperature sensor 29, an indoor heat exchanger temperature sensor 33 (heat exchanger temperature sensor), a display Lamp 36 and indoor control circuit 4 . The remote control transceiver unit 28 exchanges predetermined information with the remote control 50 by infrared communication or the like. The indoor temperature sensor 29 is a sensor that detects the temperature of the air-conditioning room, and is provided, for example, on the air intake side of the indoor heat exchanger 15 .

The indoor heat exchanger temperature sensor 33 is a sensor that detects the temperature of the indoor heat exchanger 15 (see FIG. 2 ). In addition, the indoor heat exchanger temperature sensor 33 may be installed in the indoor heat exchanger 15 or may be installed in a predetermined refrigerant pipe connected to the indoor heat exchanger 15 . The detection values of the indoor temperature sensor 29 and the indoor heat exchanger temperature sensor 33 are output to the indoor control circuit 41 . The display lamp 36 is a lamp for performing predetermined display related to the air conditioner.

Although not shown, the indoor control circuit 41 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various interfaces. etc. circuit. In addition, the CPU can read out the program stored in the ROM, develop it in the RAM, and execute various processes.

As shown in FIG. 3 , the indoor control circuit 41 includes a storage unit 41a and an indoor control unit 41b. In the storage unit 41a, in addition to a predetermined program, data received via the remote controller transmission/reception unit 28, detection values of each sensor, and the like are stored. The indoor control unit 41b controls the indoor fan motor 16a, the motor 34 for the left and right wind direction panels, the motor 35 for the up and down air direction panels, the indicator lamps 36, and the like based on the data of the storage unit 41a.

The outdoor unit 30 includes an outdoor temperature sensor 37 and an outdoor control circuit 42 in addition to the aforementioned configuration. The outdoor temperature sensor 37 is a sensor that detects the temperature of the outside air, and is provided at a predetermined portion of the outdoor unit 30 . In addition, although illustration is abbreviate|omitted in FIG. 4, the outdoor unit 30 is also provided with the sensor etc. which detect the discharge temperature of the compressor 11 (refer FIG. 1). The detection values of these sensors are output to the outdoor control circuit 42 .

Although not shown, the outdoor control circuit 42 includes circuits such as CPU, ROM, RAM, and various interfaces, and is connected to the indoor control circuit 41 via a communication line. As shown in FIG. 4 , the outdoor control circuit 42 includes a storage unit 42a and an outdoor control unit 42b.

In the storage part 42a, in addition to a predetermined program, the data etc. received from the indoor control circuit 41 are memorize|stored. The outdoor control unit 42b controls the compressor motor 11a, the outdoor fan motor 13a, the expansion valve 14, the four-way valve 17, and the like based on the data of the storage unit 42a. In addition, the indoor control circuit 41 and the outdoor control circuit 42 are collectively referred to as the control unit 40 .

<Processing by the control unit> Fig. 5 is a flowchart related to the cleaning operation of the indoor heat exchanger (refer to Figs. 1 and 4 as appropriate). In addition, although omitted in FIG. 5 , for example, when the accumulated value (summed value) of the execution time of the air-conditioning operation accumulated from the end of the previous cleaning operation reaches a predetermined value, the operation of the diagram may be started. 5 shows a series of processing. Alternatively, for example, when the user performs a predetermined operation on an operation terminal such as the remote controller 50 (see FIG. 4 ), a smartphone, or a mobile phone, the series of processes shown in FIG. 5 may be started.

In step S101 in FIG. 5 , the control unit 40 heats the indoor heat exchanger 15 . That is, the control part 40 performs control which raises the temperature of the indoor heat exchanger 15. As such a control, for example, the control part 40 circulates a refrigerant|coolant by a warm air circulation in the refrigerant circuit 10, and makes the indoor heat exchanger 15 function as a condenser. Thereby, the oil adhering to the surface of the fin 15a (refer FIG. 2) of the indoor heat exchanger 15 and the heat transfer tube 15b (refer FIG. 2) is softened (or liquefied, fluidized). The main feature of the first embodiment is that the control unit 40 performs control to increase the temperature of the indoor heat exchanger 15 ( S101 ) before performing the process of freezing the indoor heat exchanger 15 (heat exchanger) ( S102 ). one.

Next, in step S102 , the control unit 40 freezes the indoor heat exchanger 15 . That is, the control part 40 circulates a refrigerant|coolant in the refrigerant circuit 10 by the cold air circulation, makes the indoor heat exchanger 15 (heat exchanger) function as an evaporator, and performs the process of freezing the indoor heat exchanger 15.

Next, in step S103, the control part 40 thaws the indoor heat exchanger 15. For example, the control unit 40 stops the compressor 11 and increases the opening degree of the expansion valve 14 . Thereby, the high temperature refrigerant flows into the indoor heat exchanger 15 on the low pressure side from the outdoor heat exchanger 12 on the high pressure side via the expansion valve 14, and the indoor heat exchanger 15 is defrosted.

FIG. 6 is an explanatory diagram showing a state in which the indoor heat exchanger 15 is being defrosted. After the indoor heat exchanger 15 is frozen ( S102 in FIG. 5 ), the controller 40 defrosts the indoor heat exchanger 15 ( S103 ), and a high-temperature refrigerant flows through the heat transfer tubes 15 b of the indoor heat exchanger 15 . As a result, the frost 61 in the indoor heat exchanger 15 is dissolved, and a large amount of water 62 flows down the drain pan 18 along the fins 15a. Moreover, in 1st Embodiment, the control part 40 heats the indoor heat exchanger 15 before freezing of the indoor heat exchanger 15 (S101). Thereby, the oil on the surface of the indoor heat exchanger 15 is softened (or liquefied or fluidized). In addition, the oil fixed and adhered due to the deepening of the oxidation degree is also softened by heating. After that, the freezing and thawing of the indoor heat exchanger 15 are performed, so that the oil can also be washed away together with the dust 63 adhering to the indoor heat exchanger 15 .

7 is a timing chart showing changes in the opening degree of the expansion valve, the rotational speed of the indoor fan, the outdoor fan, and the temperature of the indoor heat exchanger, in addition to the states of the compressor and the four-way valve (refer to FIGS. 1 and 4 as appropriate) . In addition, the horizontal axis of FIG. 7 is time. In addition, the vertical axis of FIG. 7 represents the state of the compressor 11, the four-way valve 17, and the like. In the example of FIG. 7 , the air conditioner 100 is in a stopped state (a state in which the air conditioning operation is not performed) before time t1. Note that, immediately before the air conditioner 100 is brought to a stop state, for example, a cooling operation is performed (refer to the state of the "four-way valve" in FIG. 7 ). In addition, before the control for heating the indoor heat exchanger 15 is performed, and immediately before the air-conditioning operation is stopped, the dehumidification operation and the heating operation may be performed in addition to the cooling operation.

When heating the indoor heat exchanger 15 ( S101 in FIG. 5 ), the control unit 40 switches the four-way valve 17 to the heating cycle at time t1 , controls the expansion valve 14 to a predetermined opening degree α1 , and drives the compressor 11 . Thereby, the indoor heat exchanger 15 functions as a condenser, and the outdoor heat exchanger 12 functions as an evaporator. As a result, since a high-temperature refrigerant flows into the indoor heat exchanger 15, softening of the oil adhering to the surface of the indoor heat exchanger 15 is promoted.

In addition, in the example of FIG. 7, the control part 40 drives the indoor fan 16 during the heating process of the indoor heat exchanger 15 (time t1 to time t2). Thereby, heat exchange between the refrigerant circulating in the indoor heat exchanger 15 (condenser) and the air in the air-conditioning room can be promoted. Therefore, the pressure of the refrigerant in the indoor heat exchanger 15 can be suppressed from becoming too high, and the discharge pressure of the compressor 11 can be suppressed from becoming too high, thereby preventing the failure of the compressor 11 .

In addition, when the control for increasing the temperature of the indoor heat exchanger 15 is executed (time t1 to time t2 in FIG. 5 ), the control unit 40 causes the indoor fan 16 to be in the same direction as during normal air-conditioning operation, and controls the indoor fan Driving (forward rotation) is performed at a rotation speed equal to or less than the value calculated by dividing the upper limit value and lower limit value of the rotation speed of 16 by 2. Here, the above-mentioned "lower limit value" refers to the lower limit value of the rotational speed of the indoor fan 16 when the controller 40 drives the compressor 11 during the air-conditioning operation. This "lower limit value" does not include the stopped state of the indoor fan 16 (that is, 0 min ^-1 ). With the heating of the indoor heat exchanger 15, when the oil on the surface of the indoor heat exchanger 15 is softened, an odor peculiar to the oil may be generated. As described above, by driving the indoor fan 16 at a low speed, the control unit 40 can reduce the air volume when the oil-smelling air is blown out to the air-conditioning room.

In addition, when executing the control to raise the temperature of the indoor heat exchanger 15 (times t1 to t2 in FIG. 5 ), the control unit 40 preferably orients the up-and-down wind direction plate 24 (see FIG. 2 ) upward from the horizontal direction. In addition, the state in which the up-and-down wind direction board 24 is closed is also included in the case where the direction of the up-down wind direction board 24 is higher than a horizontal direction. Thereby, it is possible to suppress the blowing of oily air to the person in the room, and to reduce the discomfort and discomfort of the person in the room.

In addition, in the example of FIG. 7, the control part 40 drives the indoor fan 16 and also drives the outdoor fan 13 during the heating process of the indoor heat exchanger 15 (time t1 to time t2). Thereby, it is possible to balance heat dissipation from the refrigerant in the indoor heat exchanger 15 (condenser) to the air and heat absorption from the air in the outdoor heat exchanger 12 (evaporator) to the refrigerant.

In addition, in the example of FIG. 7, during the heating process of the indoor heat exchanger 15 (time t1 to time t2), the indoor heating is continued for the predetermined time Δt from the predetermined time t1a to the time t2 (the end of the heating). The heating of the heat exchanger 15 is continued in a state where the temperature of the indoor heat exchanger 15 is equal to or higher than the predetermined value Ta. The predetermined value Ta is a temperature threshold value serving as a criterion for determining whether or not softening of the oil on the surface of the indoor heat exchanger 15 is easy, and is set in advance.

In addition, the aforementioned predetermined value Ta can be set to, for example, 40°C. In addition, when the control part 40 performs the control which raises the temperature of the indoor heat exchanger 15 (heat exchanger), the state which the temperature of the indoor heat exchanger 15 is 40 degreeC or more may continue for a predetermined time. The above-mentioned predetermined time (predetermined time Δt in the example of FIG. 7 ) is a time sufficient for the oil adhering to the digestion indoor heat exchanger 15 , and is set in advance.

In addition, it is preferable that the predetermined time Δt is shorter than the time during which the indoor heat exchanger 15 is frozen (time t3 to time t4 in FIG. 7 ). Thereby, the heating of the indoor heat exchanger 15 can be suppressed from being performed for an unnecessarily long time, the comfort of the user can be improved, and the power consumption of the air conditioner 100 can be reduced.

Time t2 to time t3 after the heating of the indoor heat exchanger 15 is performed is a predetermined equilibrium period. In the example of FIG. 7 , at time t2, the control unit 40 stops the compressor 11, switches the four-way valve 17 to the cold air circulation, and increases the opening degree of the expansion valve 14 (for example, fully opens). By continuing this state from the time t2 to the time t3, the refrigerant can be easily circulated by the cold air cycle immediately after the freezing of the indoor heat exchanger 15 (the time t3 to the time t4) starts, and the compressor 11 can be prevented from being excessively applied. load. In addition, the timing of switching the four-way valve 17 to the cool air circulation (time t2 in FIG. 7 ) is an example and is not limited to this. In addition, at the time t2 in FIG. 7 , the expansion valve 14 does not necessarily have to be fully opened, and the expansion valve 14 only needs to be in a state in which the refrigerant can flow through the expansion valve 14 .

In addition, it is preferable that the control unit 40 is in the period from the time when the control for raising the temperature of the indoor heat exchanger 15 is ended (time t2 in FIG. 7 ) to the time when the process for freezing the indoor heat exchanger 15 starts (time t3 ). In order to stop the indoor fan 16. In this way, by stopping the indoor fan 16 during the predetermined balance period (time t2 to time t3 ), it is possible to reduce the user's discomfort due to noise and the like, and to reduce the power consumption of the air conditioner 100 .

In addition, it is preferable that the control part 40 starts the process of freezing the indoor heat exchanger 15 before the predetermined time has elapsed since the control which raises the temperature of the indoor heat exchanger 15 (time t2). Thereby, before the softened oil is hardened again, the oil can be washed away with the water in the freezing and thawing process of the indoor heat exchanger 15 . In addition, the said predetermined time (for example, one hour) is the time until the softened oil is left to stand at normal temperature and hardened and returns to the original state, and it is set in advance.

Next, when freezing the indoor heat exchanger 15 ( S102 in FIG. 5 ), the control unit 40 controls the expansion valve 14 to the predetermined opening degree α2 at time t3 in FIG. 7 and drives the compressor 11 . The predetermined opening degree α2 may be, for example, a smaller opening degree than during normal air-conditioning operation. In addition, during the freezing process of the indoor heat exchanger 15, the four-way valve 17 maintains a state in which the cold air circulates.

Thereby, the outdoor heat exchanger 12 functions as a condenser, and the indoor heat exchanger 15 functions as an evaporator. As a result, since the low-pressure refrigerant whose saturation temperature is lower than 0° C. flows to the indoor heat exchanger 15 , the moisture in the air is frosted and frozen on the indoor heat exchanger 15 . The control unit 40, for example, continues the state in which the detection value of the indoor heat exchanger temperature sensor 33 (refer to FIG. 4 ) is below the freezing point for a predetermined time.

In addition, even if the oil softened during the heating of the indoor heat exchanger 15 (from time t1 to time t2 ) is rapidly lowered in temperature due to freezing of the indoor heat exchanger 15, it does not immediately harden (return to its original state). Therefore, on the surface of the frozen indoor heat exchanger 15, oil, ice, and frost in a softened state coexist. Moreover, by raising the temperature of the indoor heat exchanger 15, the oil is softened, and oil stains are easily raised from the surfaces of the fins 15a and the like. In this state, when the indoor heat exchanger 15 is cooled, moisture may enter when oil floats from the surface or the like. In this state, when the indoor heat exchanger 15 is frozen, the oil is further floated from the surface due to the volume expansion of the water that occurs during the freezing process, thereby making it easier to clean afterward.

As shown in FIG. 7 , during the freezing process of the indoor heat exchanger 15 (from time t3 to time t4 ), it is preferable that the control unit 40 stops the indoor fan 16 . Thereby, the blow-out of cool air to the air-conditioning room can be suppressed. In addition, in the example of FIG. 7, the control part 40 drives the outdoor fan 13 during the freezing process of the indoor heat exchanger 15 (time t3 to time t4). Thereby, the pressure of the refrigerant in the outdoor heat exchanger 12 can be suppressed from becoming too high, and the discharge pressure of the compressor 11 can be suppressed from becoming too high.

After freezing the indoor heat exchanger 15 in this way, the control unit 40 defrosts the indoor heat exchanger 15 ( S103 in FIG. 5 ). That is, at time t4, the control unit 40 stops the compressor 11 and the outdoor fan 13, keeps the indoor fan 16 in a stopped state, and increases the opening degree of the expansion valve 14 (for example, fully opens the expansion valve 14). Thereby, the high-temperature refrigerant flows from the outdoor heat exchanger 12 on the high pressure side to the indoor heat exchanger 15 on the low pressure side via the expansion valve 14 . As a result, the frost and ice of the indoor heat exchanger 15 melt, and the oil can also be washed away together with the dust of the indoor heat exchanger 15 (see FIG. 6 ).

In addition, FIG. 7 is an illustration, and the control performed to each equipment in the cleaning operation of the indoor heat exchanger 15 is not limited to this. For example, the rotation speed of the compressor 11 and the opening degree of the expansion valve 14 may be appropriately changed during the heating process of the indoor heat exchanger 15 or during the freezing process.

＜Efficacy＞ According to the first embodiment, the control unit 40 softens the oil fixed to the indoor heat exchanger 15 by performing control to increase the temperature of the indoor heat exchanger 15 ( S101 in FIG. 5 ). After softening the oil on the surface of the indoor heat exchanger 15 in this way, the control unit 40 sequentially performs freezing and thawing of the indoor heat exchanger 15 ( S102 and S103 in FIG. 5 ). Thereby, the oil and dust on the surface of the indoor heat exchanger 15 can be washed away with the water in the freezing process. Therefore, the indoor heat exchanger 15 can be brought into a clean state. In addition, the heat exchange efficiency between the refrigerant and the air in the indoor heat exchanger 15 can be improved.

"Second Embodiment" The second embodiment is different from the first embodiment in that a heater 71 (see FIG. 8 ) is provided in the indoor unit 20A (see FIG. 8 ), and the indoor heat exchanger 15 is heated by the heater 71 . In addition, other points are the same as those of the first embodiment. Therefore, the parts different from those of the first embodiment will be described, and the description of the overlapping parts will be omitted.

8 is a vertical cross-sectional view of an indoor unit 20A included in the air conditioner according to the second embodiment. As shown in FIG. 8 , the indoor unit 20A includes a heater 71 in addition to the configuration described in the first embodiment (refer to FIG. 2 ). The heater 71 is, for example, an electric heater that is appropriately energized to assist heating of the air during heating operation. In addition, the heater 71 also has a function of softening the oil on the surface of the indoor heat exchanger 15 by raising the temperature of the indoor heat exchanger 15 by energizing before the freezing of the indoor heat exchanger 15 .

The heater 71 is provided in the vicinity of the indoor heat exchanger 15 (heat exchanger) inside the casing 19 . In the example of FIG. 8, the heater 71 is provided inside the rear side indoor heat exchanger 15d (downstream of the air flow). The heater 71 elongates and extends in parallel with the axial direction of the indoor fan 16 . In addition, the heater 71 may be provided in the front side indoor heat exchanger 15c instead of the rear side indoor heat exchanger 15d. In addition, the heater 71 may be provided in the front side indoor heat exchanger 15c and the rear side indoor heat exchanger 15d, respectively.

FIG. 9 is a functional block diagram of an air conditioner 100A according to the second embodiment. As shown in FIG. 9, the heater 71 and the indoor control circuit 41 are connected via wiring. In addition, the heater 71 can be energized in a predetermined manner in accordance with an instruction from the indoor control unit 41b (ie, the control unit 40).

10 is a timing chart showing changes in the opening degree of the expansion valve, the rotational speed of the indoor fan, the outdoor fan, the state of the heater, and the temperature of the indoor heat exchanger, in addition to the states of the compressor and the four-way valve (refer to the drawings as appropriate). 1. Figure 9). As shown in FIG. 10 , from time t1 to time t2 when heating of the indoor heat exchanger 15 is performed, the control unit 40 turns the heater 71 into an ON state. That is, when the control part 40 performs the control which raises the temperature of the indoor heat exchanger 15 (heat exchanger), it energizes the heater 71. In addition, since the indoor heat exchanger 15 is made of metal, the temperature rises not only in the installation site of the heater 71 (see FIG. 8 ) but also in the substantially entire area of the indoor heat exchanger 15 . As a result, the oil on the surface of the indoor heat exchanger 15 is softened (or liquefied or fluidized).

In the example of FIG. 10, during the heating process of the indoor heat exchanger 15, the compressor 11, the indoor fan 16, and the outdoor fan 13 are in a stopped state. As long as the indoor heat exchanger 15 can be sufficiently heated by the heater 71, the compressor 11 and the like may be stopped in this way. In addition, in the process of heating the indoor heat exchanger 15 by the heater 71, the control part 40 may circulate a refrigerant|coolant by a warm air circulation, and may drive the indoor fan 16 suitably.

After the indoor heat exchanger 15 is heated by the heater 71 , the control unit 40 causes the indoor heat exchanger 15 to function as an evaporator from time t2 to time t3 in FIG. 10 to freeze the indoor heat exchanger 15 . In addition, since the process in the freezing process of the indoor heat exchanger 15 is the same as that of 1st Embodiment, description is abbreviate|omitted. During the freezing process of the indoor heat exchanger 15, the heater 71 is turned off to prevent the temperature of the indoor heat exchanger 15 from rising.

After freezing the indoor heat exchanger 15, the control unit 40 stops the compressor 11 from time t3 and increases the opening degree of the expansion valve 14 (for example, fully opens). Thereby, since a high-temperature refrigerant flows into the indoor heat exchanger 15, the frost of the indoor heat exchanger 15 is melted. In addition, when the indoor heat exchanger 15 is thawed, it is not necessary to increase the opening degree of the expansion valve 14, and it is only necessary to be in a state in which the refrigerant can flow through the expansion valve 14. In addition, after the control part 40 performs the process of freezing the indoor heat exchanger 15, it is preferable to energize the heater 71. For example, during the defrosting process of the indoor heat exchanger 15, the control unit 40 energizes the heater 71 with the expansion valve 14 fully opened.

Thereby, the thawing of the indoor heat exchanger 15 is accelerated, and the temperature of the water dripped on the drain pan 18 (refer to FIG. 8 ) is raised by the heat of the heater 71 . Therefore, the oil fixedly adhering to the surface of the drain groove (not shown) of the drain pan 18 and the drain pipe (not shown) is softened by the heat of the warm water, and is discharged together with the water. Therefore, oil clogging of the drain groove and the drain pipe can be suppressed.

＜Efficacy＞ According to the second embodiment, before the indoor heat exchanger 15 freezes, the control unit 40 energizes the heater 71 to soften the oil on the surface of the indoor heat exchanger 15 . After that, the freezing and thawing of the indoor heat exchanger 15 are sequentially performed, and the oil and dust on the surface of the indoor heat exchanger 15 are washed away. In addition, during the defrosting process of the indoor heat exchanger 15, the control unit 40 can energize the heater 71, thereby suppressing oil clogging of the drain groove (not shown) and the drain pipe (not shown) of the drain pan 18.

"Third Embodiment" The third embodiment differs from the first embodiment in that the indoor unit 20B (see FIG. 11 ) is provided with an ultrasonic irradiator 72 (see FIG. 11 ) to heat the indoor heat exchanger 15 by ultrasonic waves. In addition, other points are the same as those of the first embodiment. Therefore, the parts different from those of the first embodiment will be described, and the description of the overlapping parts will be omitted.

11 is a vertical cross-sectional view of an indoor unit 20B included in the air conditioner according to the third embodiment. As shown in FIG. 11 , the indoor unit 20B includes an ultrasonic irradiator 72 in addition to the configuration described in the first embodiment (refer to FIG. 2 ). The ultrasonic irradiator 72 has a function of irradiating the indoor heat exchanger 15 with ultrasonic waves to raise the temperature of the indoor heat exchanger 15 and soften (or liquefy or fluidize) the oil on the surface of the indoor heat exchanger 15 .

The ultrasonic irradiator 72 is provided in the vicinity of the indoor heat exchanger 15 (heat exchanger) inside the casing 19 . In the example of FIG. 11, the ultrasonic irradiator 72 is provided in the vicinity of the connection part of the filters 21a and 21b. The ultrasonic irradiator 72 extends in parallel and elongated with respect to the axial direction of the indoor fan 16, and faces the indoor heat exchanger 15 (in the example of FIG. 11, the front side indoor heat exchanger 15c). In addition, the ultrasonic wave irradiated from the ultrasonic irradiator 72 is not only irradiated to the front-side indoor heat exchanger 15c, but also reflected in a predetermined manner on the inner wall surfaces of the casing 19, the front panel 22, etc., and also directed to the rear-side indoor heat exchanger 15d. irradiate.

FIG. 12 is a functional block diagram of an air conditioner 100B according to the third embodiment. As shown in FIG. 12 , the ultrasonic irradiator 72 and the indoor control circuit 41 are connected via wiring. In addition, ultrasonic waves can be irradiated from the ultrasonic irradiator 72 in a predetermined manner in accordance with an instruction from the indoor control unit 41b (ie, the control unit 40).

Note that the timing at which the ultrasonic irradiator 72 is turned on or off by the control unit 40 is the same as the control of the heater 71 (see FIG. 10 ) described in the second embodiment. That is, the control unit 40 irradiates the indoor heat exchanger 15 with ultrasonic waves from the ultrasonic irradiator 72 when performing control to increase the temperature of the indoor heat exchanger 15 (heat exchanger). Thereby, heat is generated in the indoor heat exchanger 15, and the oil on the surface of the indoor heat exchanger 15 is softened. In addition, as long as the indoor heat exchanger 15 is sufficiently heated by the ultrasonic irradiator 72 , the compressor 11 and the like can be maintained in a stopped state during the heating of the indoor heat exchanger 15 .

In addition, during the freezing process of the indoor heat exchanger 15, the control unit 40 keeps the ultrasonic irradiator 72 in an off state so as to prevent the temperature of the indoor heat exchanger 15 from rising. On the other hand, during the defrosting process of the indoor heat exchanger 15 , the control unit 40 may irradiate the indoor heat exchanger 15 with ultrasonic waves using the ultrasonic irradiator 72 . Thereby, the thawing of the indoor heat exchanger 15 can be promoted, and the temperature of the water dripped on the drain pan 18 (refer to FIG. 11 ) can be raised. Therefore, oil clogging of the drain groove (not shown) and the drain pipe (not shown) of the drain pan 18 can be suppressed.

＜Efficacy＞ According to the third embodiment, before the indoor heat exchanger 15 is frozen, the control unit 40 irradiates the indoor heat exchanger 15 with ultrasonic waves from the ultrasonic irradiator 72 to soften the oil on the surface of the indoor heat exchanger 15 . After that, the freezing and thawing of the indoor heat exchanger 15 are sequentially performed, so that the oil and dust on the surface of the indoor heat exchanger 15 are washed away by the water in the freezing process.

"Fourth Embodiment" The fourth embodiment is different from the first embodiment in that an imaging unit 73 is provided in the indoor unit 20C (see FIG. 13 ), and the indoor heat exchanger 15 is heated based on the imaging result of the imaging unit 73 . In addition, other points are the same as those of the first embodiment. Therefore, the parts different from those of the first embodiment will be described, and the description of the overlapping parts will be omitted.

13 is a vertical cross-sectional view of an indoor unit 20C included in the air conditioner according to the fourth embodiment. As shown in FIG. 13 , the indoor unit 20C includes an imaging unit 73 in addition to the configuration described in the first embodiment (refer to FIG. 2 ). The imaging unit 73 captures an image of the air-conditioned room, and is provided in the housing 19 in a predetermined manner. In the example of FIG. 13 , the imaging unit 73 is provided between the front panel 22 and the up-and-down wind direction plate 24 in a vertical cross-sectional view. In addition, in order to image the air-conditioned room, the imaging unit 73 is provided in a state facing downward at a predetermined angle with respect to the horizontal direction.

Fig. 14 is a functional block diagram of an air conditioner 100C according to the fourth embodiment. Although not shown, the imaging unit 73 shown in FIG. 14 includes a CCD sensor (Charge Coupled Device) and a CMOS sensor (Complementary Metal Oxide Semiconductor) An image pickup element (not shown) such as this is connected to the indoor control circuit 41 via wiring. In addition, the imaging result (image data) of the imaging unit 73 can be output to the indoor control circuit 41 .

The indoor control circuit 41 has a function of detecting a person in the air-conditioned room based on the imaging result of the imaging unit 73 . For example, the indoor control circuit 41 extracts a person's head, chest, arms, feet, and the like based on image information input from the imaging unit 73 . Then, the imaging unit 73 detects a person based on the extracted positional relationship of each unit. In addition, the aforementioned method is an example, and the method of detecting a person is not limited to this. In addition, regarding the control part 40 including the indoor control circuit 41 and the outdoor control circuit 42, the control which raises the temperature of the indoor heat exchanger 15 is performed based on the imaging result of the imaging part 73.

Fig. 15 is a flowchart related to the cleaning operation of the indoor heat exchanger. In step S201 of FIG. 15 , the control unit 40 determines whether or not a kitchen operation or a meal operation is detected. In addition, "kitchen action" refers to the action when a person in the room cooks. When people in the room cook in the kitchen, they mostly move back and forth in the lateral direction near the kitchen. Therefore, the control unit 40, for example, determines that the indoor head is within a predetermined range (including the average height of the head when the person is standing) and when the person in the room reciprocates laterally. Man performs kitchen action.

On the other hand, the "meal action" refers to the action of the person in the room when they eat. When people in the room are eating, most of them are sitting on chairs and their heads are basically motionless. Therefore, the control unit 40 , for example, when the height position of the head of the indoor person is within a predetermined range (including the average height position of the head when the person is seated) and the moving distance of the head of the indoor person is equal to or less than a predetermined value , it is determined that the person in the room is eating.

In step S201, when a kitchen operation or a meal operation is detected (S201: YES), the process of the control unit 40 proceeds to step S202. In step S202, the control part 40 sets so that the frequency of the cleaning operation of the indoor heat exchanger 15 may be increased. That is, the control unit 40 is set to increase the frequency of the cleaning operation during the heating of the indoor heat exchanger 15 compared to when the kitchen operation and the meal operation are not detected.

Next, in step S203, the control unit 40 determines whether or not the accumulated time of the air-conditioning operation has reached a predetermined value. That is, the control part 40 determines whether the accumulated value (summation value) which accumulated the execution time of the air-conditioning operation from the end of the previous cleaning operation has reached a predetermined value. In step S203, when the accumulated time of the air-conditioning operation reaches a predetermined value (S203: YES), the process of the control unit 40 proceeds to step S204. And the control part 40 performs heating (S204), freezing (S205), and thawing (S206) of the indoor heat exchanger 15 in this order. In addition, since the process of step S204 to step S206 is the same as that of step S101 to step S103 of 1st Embodiment (refer FIG. 5), description is abbreviate|omitted. On the other hand, in step S203, if the accumulated time of the air-conditioning operation has not reached the predetermined value (S203: NO), the control unit 40 repeats the process of step S203.

As described above, when the kitchen operation or the meal operation is detected ( S201 : YES), the control unit 40 performs the cleaning operation during the heating of the indoor heat exchanger 15 at a high frequency ( S202 ), thereby enabling the indoor heat exchanger 15 to be in a clean state. That is, even if the oil smoke suspended in the air during cooking or eating adheres to the indoor heat exchanger 15, the oil can be softened by the heating of the indoor heat exchanger 15, and can be washed away together with dust by freezing and thawing.

In addition, in step S201, if the kitchen operation and the meal operation are not detected (S201: NO), the control unit 40 proceeds to step S203 as scheduled. Then, in step S203, when the accumulated time of the air-conditioning operation reaches a predetermined value (S203: YES), the control unit 40 performs the cleaning operation of the indoor heat exchanger 15 during heating at the normal frequency. In addition, regardless of whether a kitchen operation or a meal operation is detected, it is possible to appropriately perform a non-heating operation between the current cleaning operation during heating of the indoor heat exchanger 15 and the next cleaning operation during heating. Cleaning operation (freeze, thaw).

＜Efficacy＞ According to the fourth embodiment, the control unit 40 performs control to increase the temperature of the indoor heat exchanger 15 based on the imaging result of the imaging unit 73, and then performs freezing of the indoor heat exchanger 15 and the like. Thereby, even if oil adheres to the indoor heat exchanger 15 during cooking or eating, the oil can be softened by the heating of the indoor heat exchanger 15, and the oil can be washed away together with dust. In addition, the oil fixed and adhered with the deepening of the oxidation degree is softened by heating, and is further washed away together with dust by freezing and thawing of the indoor heat exchanger 15 .

"Fifth Embodiment" The fifth embodiment is different from the first embodiment in that a filter cleaning unit 74 (see FIG. 16 ) is provided in the indoor unit 20D (see FIG. 16 ). The fifth embodiment is different from the first embodiment in that the frequency of the cleaning operation during heating of the indoor heat exchanger 15 is lower than the frequency of cleaning of the filters 21a and 21b (see FIG. 16 ). In addition, other points are the same as those of the first embodiment. Therefore, the parts different from those of the first embodiment will be described, and the description of the overlapping parts will be omitted.

16 is a perspective view of the filters 21a and 21b and the filter cleaning unit 74 included in the indoor unit 20D of the air conditioner according to the fifth embodiment. As shown in FIG. 16 , the indoor unit 20D includes a movable filter cleaning unit 74 that cleans the filters 21a and 21b. The filter cleaning part 74 is provided with the housing|casing 74a, the brush 74b for filter cleaning, and the motor (not shown) for filter cleaning.

The frame body 74a has an inverted L shape, and is disposed outside the filters 21a and 21b. The filter-cleaning brush 74b is a brush for brushing off the dust adhering to the filters 21a and 21b, and is provided in the inner side of the housing|casing 74a. A filter cleaning motor (not shown) is a drive source that moves the frame body 74a in the lateral direction. Moreover, when the motor for filter cleaning is driven, the housing|casing 74a moves in the width direction, and the dust on the surface of the filters 21a and 21b is brushed off by the brush 74b for filter cleaning.

In addition, it is preferable that the control unit 40 set the frequency of the control to raise the temperature of the indoor heat exchanger 15 (heat exchanger) during the cleaning operation to be lower than the frequency of the filter cleaning unit 74 to clean the filters 21a and 21b. . By reducing the frequency of heating the indoor heat exchanger 15 in this way, it is possible to reduce the user's unpleasantness and discomfort when the warm air is blown into the air-conditioned room.

＜Efficacy＞ According to the fifth embodiment, the control unit 40 makes the frequency of the cleaning operation during the heating of the indoor heat exchanger 15 lower than the frequency of cleaning the filters 21a and 21b. Thereby, the unpleasantness and discomfort of the user caused when the warm air is blown into the air-conditioned room can be reduced.

"Sixth Embodiment" The sixth embodiment differs from the first embodiment in that, in place of the indoor heat exchanger 15 (see FIG. 1 ), the heating, freezing, and thawing of the outdoor heat exchanger 12 are sequentially performed. In addition, other points (the structure of an air conditioner, etc., refer FIG. 1 to FIG. 4) are the same as those of 1st Embodiment. Therefore, the parts different from those of the first embodiment will be described, and the description of the overlapping parts will be omitted.

Fig. 17 is a flowchart related to the cleaning operation of the outdoor heat exchanger in the air conditioner according to the sixth embodiment (see Figs. 1 and 4 as appropriate). In addition, although omitted in FIG. 17 , for example, when the accumulated value (the summed value) of the accumulated execution time of the air-conditioning operation since the end of the previous cleaning operation reaches a predetermined value, the operation shown in FIG. 17 starts. a series of treatments. Further, when the user operates an operation terminal such as the remote controller 50 (see FIG. 4 ) in a predetermined manner, the series of processing shown in FIG. 17 may be started. In addition, depending on the installation environment of the outdoor unit 30 (see FIG. 1 ), oil may adhere to the outdoor heat exchanger 12 in addition to dust.

In step S301 , the control unit 40 heats the outdoor heat exchanger 12 . That is, the control part 40 performs the control which raises the temperature of the outdoor heat exchanger 12 (S301) before performing the process (S302) which freezes the outdoor heat exchanger 12 (heat exchanger). For example, the control part 40 circulates a refrigerant|coolant in the refrigerant circuit 10 by a cold air circulation, and makes the outdoor heat exchanger 12 function as a condenser.

Moreover, it is preferable that the control part 40 continues the state in which the temperature of the outdoor heat exchanger 12 is 40 degreeC or more for a predetermined time. Thereby, the oil fixed to the outdoor heat exchanger 12 is heated and softened (or liquefied or fluidized). Furthermore, an outdoor heat exchanger temperature sensor (not shown) that detects the temperature of the outdoor heat exchanger 12 is provided.

Next, in step S302 , the control unit 40 freezes the outdoor heat exchanger 12 . That is, the control part 40 circulates a refrigerant|coolant by the warm air circulation in the refrigerant circuit 10, makes the outdoor heat exchanger 12 (heat exchanger) function as an evaporator, and performs the process of freezing the outdoor heat exchanger 12.

Next, in step S303 , the control unit 40 defrosts the outdoor heat exchanger 12 . For example, the control unit 40 stops the compressor 11 and increases the opening degree of the expansion valve 14 . Thereby, the high-temperature refrigerant flows from the indoor heat exchanger 15 on the high pressure side to the outdoor heat exchanger 12 on the low pressure side through the refrigerant piping. As a result, the frost and ice of the outdoor heat exchanger 12 melt, and the dust and oil are washed away.

18 is a timing chart showing changes in the opening degree of the expansion valve, the rotational speed of the indoor fan, the outdoor fan, and the temperature of the outdoor heat exchanger, in addition to the states of the compressor and the four-way valve. In addition, before the control for heating the outdoor heat exchanger 12 is performed, and immediately before the air-conditioning operation is stopped, the cooling operation and the dehumidifying operation may be performed in addition to the heating operation. As shown in FIG. 18 , from time t1 to time t2 , the control unit 40 puts the four-way valve 17 into a state of cooling air, controls the expansion valve 14 to a predetermined opening degree α1, drives the compressor 11, and drives the outdoor heat exchanger 12 It functions as a condenser (S301 of FIG. 17). Thereby, the outdoor heat exchanger 12 is heated. During heating of the outdoor heat exchanger 12, the control unit 40 drives the indoor fan 16 at a low speed and also drives the outdoor fan 13 (fan). In addition, it is preferable that the control unit 40 controls the indoor fan 16 to make the sum of the upper limit value and the lower limit value of the rotational speed of the indoor fan 16 during at least a part of the control to increase the temperature of the outdoor heat exchanger 12 Drive (forward rotation or reverse rotation) at a rotational speed equal to or less than the value calculated by dividing by 2. Here, the above-mentioned "lower limit value" refers to the lower limit value of the rotational speed of the indoor fan 16 when the controller 40 drives the compressor 11 during the air-conditioning operation. This "lower limit value" does not include the stopped state of the indoor fan 16 (ie, 0 [min ^-1 ]). Thereby, the blow-out of cool air to the air-conditioning room can be suppressed. In addition, the drive of the outdoor fan 13 can suppress the discharge pressure of the compressor 11 from becoming too high. In addition, the rotational speed of the indoor fan 16 in the heating process of the outdoor heat exchanger 12 and the rotational speed of the indoor fan 16 in the subsequent freezing process are not necessarily the same. In addition, the same is true for the outdoor fan 13 .

After heating the outdoor heat exchanger 12, the control unit 40 switches the four-way valve 17 to the heating cycle (time t2), controls the expansion valve 14 to a predetermined opening degree α2, drives the compressor 11, and causes the outdoor heat exchanger 12 functions as an evaporator (S302 in FIG. 17 ). Thereby, the freezing of the outdoor heat exchanger 12 is performed. In addition, during the freezing process of the outdoor heat exchanger 12, the indoor fan 16 and the outdoor fan 13 are driven in a predetermined manner.

After the outdoor heat exchanger 12 is frozen, the control unit 40 increases the opening degree of the expansion valve 14 from time t4 to defrost the outdoor heat exchanger 12 ( S303 in FIG. 17 ). Thereby, the high-temperature refrigerant flows from the indoor heat exchanger 15 on the high pressure side to the outdoor heat exchanger 12 on the low pressure side, so that frost and ice in the outdoor heat exchanger 12 are melted, and dust and oil are washed away.

＜Efficacy＞ According to the sixth embodiment, the control unit 40 performs control to increase the temperature of the outdoor heat exchanger 12 ( S301 in FIG. 17 ), thereby softening the oil adhering to the outdoor heat exchanger 12 . In addition, the control unit 40 sequentially performs freezing and thawing of the outdoor heat exchanger 12 (S302 and S303 in FIG. 17 ). Thereby, the oil adhering to the outdoor heat exchanger 12 can be washed away together with dust by the water in the freezing process. Therefore, the outdoor heat exchanger 12 can be brought into a clean state, and the heat exchange efficiency of the outdoor heat exchanger 12 can be improved.

"Seventh Embodiment" The seventh embodiment is different from the first embodiment in that the cleaning operation of the indoor heat exchanger 15 and the cleaning operation of the outdoor heat exchanger 12 are performed continuously. In addition, other points (the structure of an air conditioner, etc., refer FIG. 1 to FIG. 4) are the same as those of 1st Embodiment. Therefore, the parts different from those of the first embodiment will be described, and the description of the overlapping parts will be omitted.

19 is a flowchart related to the cleaning operation of the indoor heat exchanger and the outdoor heat exchanger in the air conditioner according to the seventh embodiment (refer to FIGS. 1 and 4 as appropriate). In step S401 , the control unit 40 heats the indoor heat exchanger 15 . For example, the control part 40 raises the temperature of the indoor heat exchanger 15 by making the indoor heat exchanger 15 function as a condenser by circulating a refrigerant|coolant by the warm air circulation in the refrigerant circuit 10. Thereby, the oil on the surface of the indoor heat exchanger 15 is softened.

In step S402, the control unit 40 circulates the refrigerant in the refrigerant circuit 10 by the cold air circulation, freezes the indoor heat exchanger 15 (evaporator), and heats the outdoor heat exchanger 12 (condenser). Thereby, while frost and ice are generated in the indoor heat exchanger 15, the oil on the surface of the outdoor heat exchanger 12 is softened. Next, in step S403, the control unit 40 circulates the refrigerant in the refrigerant circuit 10 by the warm air circulation, defrosts the indoor heat exchanger 15 (condenser), and causes the outdoor heat exchanger 12 (evaporator) freeze. Thereby, the oil on the surface of the indoor heat exchanger 15 can be washed away together with dust, while frost and ice are generated in the outdoor heat exchanger 12 .

In step S404, the control part 40 thaws the outdoor heat exchanger 12. For example, the control unit 40 increases the opening degree of the expansion valve 14 so that the high-temperature refrigerant flows from the indoor heat exchanger 15 on the high pressure side to the outdoor heat exchanger 12 on the low pressure side. Thereby, the oil on the surface of the outdoor heat exchanger 12 can be washed away together with dust. After performing the process of step S404, the control part 40 complete|finishes a series of processes concerning a cleaning operation (end).

＜Efficacy＞ According to the seventh embodiment, while the indoor heat exchanger 15 is being frozen, the outdoor heat exchanger 12 is also heated ( S402 in FIG. 19 ). In addition, during the defrosting process of the indoor heat exchanger 15, the freezing of the outdoor heat exchanger 12 is also performed (S403 in FIG. 19). Thereby, since both the indoor heat exchanger 15 and the outdoor heat exchanger 12 can be cleaned in a short time, the comfort of the user can be improved, and the power consumption of the air conditioner 100 required for the cleaning operation can be reduced.

"Variation" As mentioned above, although the air conditioner 100 etc. of this invention were demonstrated based on each embodiment, this invention is not limited to this, Various changes are possible. For example, in the first embodiment, the case where the control unit 40 freezes the indoor heat exchanger 15 and cleans the indoor heat exchanger 15 has been described, but the indoor heat exchanger 15 may be dew-condensed instead of this. As a specific example, the control unit 40 first calculates the dew point of the air based on the detected values of the temperature and humidity of the air-conditioned room. And the control part 40 controls the opening degree of the expansion valve 14, etc. so that the temperature of the indoor heat exchanger 15 may become below the said dew point and higher than a predetermined freezing temperature. In addition, the "freezing temperature" refers to the temperature at which moisture contained in the air starts to freeze in the indoor heat exchanger 15 when the temperature of the indoor heat exchanger 15 is lowered. In this way, the indoor heat exchanger 15 can also be washed with the water in the dew condensation process of the indoor heat exchanger 15 . In addition, in the same manner as in the second to seventh embodiments, the control unit 40 may clean the indoor heat exchanger 15 and/or the outdoor heat exchanger 12 (ie, heat exchanger) with dew condensation water.

In the first embodiment, the case where the control unit 40 drives the indoor fan 16 during the heating of the indoor heat exchanger 15 (time t1 to time t2 in FIG. 7 ) has been described, but the present invention is not limited to this. That is, the control part 40 may drive the indoor fan 16 (fan) while performing at least a part of the control which raises the temperature of the indoor heat exchanger 15 (heat exchanger). Thereby, the discharge pressure of the compressor 11 can be suppressed from becoming too high. In addition, the same applies to the seventh embodiment except the second embodiment to the fifth embodiment. In addition, in the sixth and seventh embodiments, the control unit 40 may drive the outdoor fan 13 (fan) while performing at least a part of the control to increase the temperature of the outdoor heat exchanger 12 (heat exchanger).

In addition, in the first embodiment, the control unit 40 causes the indoor fan 16 to be oriented higher than the horizontal direction while the indoor heat exchanger 15 is being heated (from time t1 to time t2 in FIG. 7 ). The case where the low-speed driving is performed in forward rotation has been described, but the present invention is not limited to this. That is, the control part 40 may reversely rotate the indoor fan 16 while performing at least a part of the control which raises the temperature of the indoor heat exchanger 15. In addition, the reverse rotation of the indoor fan 16 refers to the reverse rotation at the time of normal air-conditioning operation. Thereby, air can be blown toward the ceiling via the air intake ports 25a and 25b (see FIG. 2 ), and the heated air can be suppressed from directly rushing toward the user.

In the first embodiment, the case where the control unit 40 stops the indoor fan 16 during the freezing process of the indoor heat exchanger 15 (from time t3 to time t4 in FIG. 7 ) has been described, but the present invention is not limited to this. . That is, the control part 40 may stop the indoor fan 16 during at least a part of the process of freezing (or dew condensation) the indoor heat exchanger 15. Thereby, while the indoor heat exchanger 15 is being frozen, it is possible to suppress the blowing of cool air to the air-conditioning room. In particular, it is preferable that the control unit 40 stops the indoor fan 16 within a predetermined time from the start of the process of freezing (or dew condensation) in the indoor heat exchanger 15 . Thereby, the temperature of the indoor heat exchanger 15 which has been heated to a high temperature can be rapidly lowered, and the indoor heat exchanger 15 can be frozen. In addition, during the freezing process of the indoor heat exchanger 15, the control unit 40 may drive the indoor fan 16 at a low speed (a rotational speed of a degree that enables freezing). In addition, the same applies to the second to seventh embodiments.

In addition, in the first embodiment, the control unit 40 preferably does not perform the detection when the detection value of the indoor temperature sensor 29 (refer to FIG. 4 ) or the outdoor temperature sensor 37 (refer to FIG. 4 ) is a predetermined value or more. Control for raising the temperature of the indoor heat exchanger 15 (heat exchanger). Thereby, the temperature of the air-conditioning room can be prevented from being too high due to the heating of the indoor heat exchanger 15, and the comfort of the user can be improved. In addition, the same applies to the second to seventh embodiments. In addition, in the sixth and seventh embodiments, the control unit 40 compares the detection value of the indoor temperature sensor 29 (refer to FIG. 4 ) or the outdoor temperature sensor 37 (refer to FIG. 4 ) to a predetermined value or more. It is preferable not to perform the control which raises the temperature of the outdoor heat exchanger 12 (heat exchanger). Thereby, in the freezing process after the heating of the outdoor heat exchanger 12, it can suppress that the high temperature air which absorbed heat from the indoor heat exchanger 15 (condenser) is blown out into the room. In addition, for example, when the indoor heat exchanger 15 (heat exchanger) is subjected to freezing or dew condensation processing, when the detection value of the indoor heat exchanger temperature sensor 33 (heat exchanger temperature sensor, see FIG. 4 ) is already When the value is equal to or greater than the predetermined value, the control unit 40 preferably starts the above-described processing without performing the control for raising the temperature of the indoor heat exchanger 15 . As a specific example of this, when the accumulated value of the execution time of the air-conditioning operation since the previous process of freezing or dew condensation in the indoor heat exchanger 15 was completed reaches a predetermined value, or when the remote controller 50 (operation terminal) issues a start process (indoor When the detection value of the indoor heat exchanger temperature sensor 33 reaches a predetermined value or more at the time of the instruction to freeze the heat exchanger 15, etc.), the control unit 40 may not perform the control to increase the temperature of the indoor heat exchanger 15, And start processing such as this freezing. In addition, when an instruction to start processing (freezing of the indoor heat exchanger 15, etc.) is issued from the remote controller 50 (operation terminal), the indoor heat exchanger temperature sensor 33 is within a time range that goes back a predetermined time from the start instruction. When the detected value of , is equal to or greater than a predetermined value, the control unit 40 may not perform the control to increase the temperature of the indoor heat exchanger 15, and may start processing such as freezing this time. When the freezing of the indoor heat exchanger 15 or the like is started, if the temperature of the indoor heat exchanger 15 is already relatively high (for example, when the heating operation has been performed just before), it is not necessary to heat the indoor heat exchanger 15 . Thereby, the time required for cleaning of the indoor heat exchanger 15 can be shortened, and the power consumption of the air conditioner 100 can be reduced. Similarly, when the detected value of the outdoor heat exchanger temperature sensor (heat exchanger temperature sensor, not shown) is equal to or greater than a predetermined value, the control unit 40 may not perform the step of increasing the temperature of the outdoor heat exchanger 12 . control, and the process of freezing or dew condensation of the outdoor heat exchanger 12 is started.

In addition, in the first embodiment, the case where the control unit 40 fully opens the expansion valve 14 (after time t4 in FIG. 7 ) after freezing the indoor heat exchanger 15 to defrost the indoor heat exchanger 15 has been described. , but not limited to this. For example, when the indoor heat exchanger 15 is thawed, it is not necessary to increase the opening degree of the expansion valve 14, and it is only necessary to be in a state in which the refrigerant can flow through the expansion valve 14. In addition, the control unit 40 may cause the indoor heat exchanger 15 to function as a condenser by circulating the refrigerant in the refrigerant circuit 10 by the warm air circulation, thereby defrosting the indoor heat exchanger 15 . In addition, the controller 40 may stop the compressor 11 and appropriately drive the indoor fan 16 to defrost the indoor heat exchanger 15, and the same applies to the second to seventh embodiments.

In addition, in the first embodiment, the case where the heating, freezing, and thawing of the indoor heat exchanger 15 are sequentially performed as the cleaning operation has been described (see FIG. 5 ), but the thawing of the indoor heat exchanger 15 may be performed. The processing (S103 in FIG. 5 ) is omitted. When the indoor heat exchanger 15 is left as it is after being frozen, frost and ice in the indoor heat exchanger 15 may be naturally thawed by the heat of the air. In addition, the same applies to the second to seventh embodiments.

In addition, the respective embodiments can be appropriately combined. For example, the first embodiment and the second embodiment may be combined, and the control unit 40 may cause the indoor heat exchanger 15 to function as a condenser (first embodiment) and energize the heater 71 (second embodiment), thereby The indoor heat exchanger 15 is heated. Further, for example, the first embodiment and the third embodiment may be combined, and the control unit 40 may cause the indoor heat exchanger 15 to function as a condenser (first embodiment), and irradiate ultrasonic waves from the ultrasonic irradiator 72 (third embodiment) Embodiment), thereby heating the indoor heat exchanger 15. In addition, as a heating method of the indoor heat exchanger 15, all of the second to third embodiments may be combined.

In addition, for example, the second embodiment, the third embodiment, and the sixth embodiment may be combined. In addition, as a heating method of the indoor heat exchanger 15 or the outdoor heat exchanger 12, other methods may be appropriately adopted.

In addition, in the fourth embodiment, when the control unit 40 detects the kitchen operation and the meal operation based on the imaging result of the imaging unit 73 (see FIG. 13 ) ( S201 in FIG. 15 : YES), the frequency of the cleaning operation is increased. The process ( S202 ) of , has been described, but it is not limited to this. For example, when a thermopile or a thermography is used as the "imaging unit", the control unit 40 may increase the temperature when a heat source (fire in a gas furnace, etc.) is detected in an air-conditioned room. The frequency of the cleaning operation of the indoor heat exchanger 15 during heating. According to this structure, even if oil adheres to the indoor heat exchanger 15 during cooking, the oil can be softened by the heating of the indoor heat exchanger 15, and the oil can be washed away by the water during freezing.

In addition, in place of the imaging of the air-conditioned room described in the fourth embodiment, the following processing may be performed. That is, information on whether there is a kitchen or a meal may be input based on the user's operation of an "operation terminal" such as a smartphone, mobile phone, or tablet other than the remote controller 50 (see FIG. 4 ). In addition, when there is a kitchen or a meal in the air-conditioned room, the control unit 40 may perform the cleaning operation of the indoor heat exchanger 15 during heating at a high frequency. In this way, the control unit 40 can perform control to increase the temperature of the indoor heat exchanger 15 based on the operation of the "operation terminal", and can bring the indoor heat exchanger 15 into a clean state.

In addition, when the user performs a predetermined operation on an "operation terminal" such as the remote controller 50 (see FIG. 4 ), the control unit 40 can perform the cleaning operation of the indoor heat exchanger 15 during heating. For example, in an intermediate period such as spring and autumn, when the air conditioner 100 is not used for several months, oil dirt tends to accumulate in the indoor heat exchanger 15 at this time. In this case, when the air conditioner 100 is used again in summer and winter, the user can perform a predetermined operation on an "operation terminal" such as the remote controller 50 to perform the cleaning operation. Thereby, the oil stain of the indoor heat exchanger 15 can be washed away.

In addition, in the seventh embodiment, when the cleaning operation of the indoor heat exchanger 15 and the outdoor heat exchanger 12 is performed, the control unit 40 first controls the heating of the indoor heat exchanger 15 (see FIG. 19), but instead of this method, only the following processing can be performed. That is, after controlling the outdoor heat exchanger 12 to be heated in a predetermined manner, the control unit 40 circulates the refrigerant by the heating cycle to freeze the outdoor heat exchanger 12 (evaporator), while exchanging the indoor heat. 15 (condenser) for heating. Moreover, the control part 40 circulates a refrigerant|coolant by a cold air circulation, defrosts the outdoor heat exchanger 12 (condenser), and freezes the indoor heat exchanger 15 (evaporator) on the other hand. Next, the control part 40 increases the opening degree of the expansion valve 14, and defrosts the indoor heat exchanger 15, for example. With such a process, both the indoor heat exchanger 15 and the outdoor heat exchanger 12 can be cleaned.

In addition, in each embodiment, the structure in which each of the indoor unit 20 (refer to FIG. 1 ) and the outdoor unit 30 (refer to FIG. 1 ) is provided has been described, but the present invention is not limited to this. That is, a plurality of indoor units connected in parallel may be installed, and a plurality of outdoor units connected in parallel may be installed. In addition to the room air conditioner, the respective embodiments are also applicable to the whole air conditioner and the building multi-unit air conditioner.

In addition, each embodiment has been described in detail in order to understand the present invention, but it is not limited to having all the structures described. In addition, other structures may be added to, or deleted or replaced with, a part of the structures of the respective embodiments. In addition, the aforementioned mechanism or structure is shown based on the need for description, and it is not necessary to present all the mechanism or structure as a product.

4: Indoor control circuit 9: Reservoir 10: Refrigerant circuit 11: Compressor 11a: Compressor motor 12: Outdoor heat exchanger (heat exchanger) 12b, 15b: Heat transfer tubes 13: Outdoor fan (fan) 13a: Outdoor fan motor 14: Expansion valve 15: Indoor heat exchanger (heat exchanger) 15a: fins 15c: Front indoor heat exchanger 15d: Rear side indoor heat exchanger 16: Indoor fan (fan) 16a: Indoor fan motor 16b: Fan blades 16c: Divider 17: Four-way valve 18: Drain pan 19,31,74a: Frame 20, 20A, 20B, 20C, 20D: Indoor unit 21a, 21b: Filters 22: Front panel 23: Left and right wind direction boards 24: Up and down wind direction board 25a, 25b: Air intake 26: Blow out the wind path 27: Air outlet 28: Remote control transceiver 29: Indoor temperature sensor 30: Outdoor unit 31a: Bottom plate 32: Electrical component box 33: Indoor heat exchanger temperature sensor (heat exchanger temperature sensor) 34: Motors for left and right wind direction panels 35: Motor for up and down wind direction plates 36: Display light 37: Outdoor temperature sensor 40: Control Department 41: Indoor control circuit 41a, 42a: Storage section 41b: Indoor Control Department 42: Outdoor control circuit 42b: Outdoor Control Department 50: Remote control (operating terminal) 61: Cream 62: Water 63: Dust 71: Heater 72: Ultrasonic Illuminator 73: Camera Department 74: Filter cleaning department 74b: Filter cleaning brush 100, 100A, 100B, 100C: Air conditioner t1 to t4, t1a: time Ta: predetermined value α1, α2: Predetermined opening Δt: Scheduled time

1 is a block diagram of an air conditioner according to a first embodiment. [ Fig. 2] Fig. 2 is a vertical cross-sectional view of an indoor unit included in the air conditioner according to the first embodiment. [ Fig. 3] Fig. 3 is a perspective view of a state in which a side plate and a top plate of the casing of the outdoor unit included in the air conditioner according to the first embodiment are removed. 4 is a functional block diagram of the air conditioner according to the first embodiment. [ Fig. 5] Fig. 5 is a flowchart related to the cleaning operation of the indoor heat exchanger of the air conditioner according to the first embodiment. [ Fig. 6] Fig. 6 is an explanatory diagram showing a state during thawing of the indoor heat exchanger included in the air conditioner according to the first embodiment. [ Fig. 7] Fig. 7 shows changes in the opening degree of the expansion valve, the rotational speed of the indoor fan and the outdoor fan, and the temperature of the indoor heat exchanger, in addition to the states of the compressor and the four-way valve, in the air conditioner according to the first embodiment. Timing diagram. [ Fig. 8] Fig. 8 is a vertical cross-sectional view of an indoor unit included in an air conditioner according to a second embodiment. [ Fig. 9] Fig. 9 is a functional block diagram of an air conditioner according to a second embodiment. 10 is a diagram showing the opening degree of the expansion valve, the rotational speed of the indoor fan and the outdoor fan, the state of the heater, and the indoor heat exchange, in addition to the state of the compressor and the four-way valve, in the air conditioner according to the second embodiment. timing diagram of the temperature change of the device. 11 is a vertical cross-sectional view of an indoor unit included in an air conditioner according to a third embodiment. 12 is a functional block diagram of the air conditioner according to the third embodiment. 13 is a vertical cross-sectional view of an indoor unit included in an air conditioner according to a fourth embodiment. 14 is a functional block diagram of an air conditioner according to a fourth embodiment. [ Fig. 15] Fig. 15 is a flowchart related to the cleaning operation of the indoor heat exchanger of the air conditioner according to the fourth embodiment. 16 is a perspective view of a filter and a filter cleaning unit included in an indoor unit of an air conditioner according to a fifth embodiment. 17 is a flowchart related to the cleaning operation of the outdoor heat exchanger of the air conditioner according to the sixth embodiment. 18 is a graph showing changes in the opening degree of the expansion valve, the rotational speeds of the indoor fan and the outdoor fan, and the temperature of the outdoor heat exchanger, in addition to the states of the compressor and the four-way valve, in the air conditioner according to the sixth embodiment. Timing diagram. [ Fig. 19] Fig. 19 is a flowchart related to the cleaning operation of the indoor heat exchanger and the outdoor heat exchanger of the air conditioner according to the seventh embodiment.

10: Refrigerant circuit

11: Compressor

11a: Compressor motor

12: Outdoor heat exchanger (heat exchanger)

13: Outdoor fan (fan)

13a: Outdoor fan motor

14: Expansion valve

15: Indoor heat exchanger (heat exchanger)

16: Indoor fan (fan)

17: Four-way valve

20: Indoor unit

30: Outdoor unit

100: Air conditioner

Claims (12)

An air conditioner is provided with a compressor, an outdoor heat exchanger, an expansion valve and an indoor heat exchanger; and further comprising: a control unit for performing a cleaning operation of a heat exchanger serving as the indoor heat exchanger or the outdoor heat exchanger; The said control part raises the temperature of the said heat exchanger in the said cleaning operation, and sets the said heat exchanger to the temperature below freezing point or the temperature below dew point temperature. The air conditioner according to claim 1, wherein, in the control for increasing the temperature of the heat exchanger, the control unit continues the state where the temperature of the heat exchanger is 40° C. or higher for a predetermined time. The air conditioner according to claim 1, wherein, in the control for increasing the temperature of the heat exchanger, the control unit causes the heat exchanger to function as a condenser, and sends the control unit to a heater provided in the vicinity of the heat exchanger. The heat exchanger is energized or irradiated with ultrasonic waves from an ultrasonic irradiator. The air conditioner according to claim 1, wherein the control unit starts to bring the heat exchanger to a temperature below freezing point or dew point temperature before a predetermined time elapses from the time when the control for raising the temperature of the heat exchanger is finished. temperature treatment. The air conditioner according to claim 1, further comprising: a fan installed in the vicinity of the heat exchanger; The control unit drives the fan during at least a part of the control for increasing the temperature of the heat exchanger. The air conditioner according to claim 1, wherein the heat exchanger is the indoor heat exchanger; further comprising: an indoor fan provided in the vicinity of the indoor heat exchanger; Calculated by dividing the sum of the upper limit value and the lower limit value of the rotational speed of the indoor fan by 2 with the indoor fan in the same orientation as during normal air-conditioning operation during at least a part of the temperature rise control The lower limit value is the lower limit value of the rotation speed of the indoor fan when the controller drives the compressor during air-conditioning operation, and the lower limit value is the lower limit value of the rotation speed of the indoor fan. The stop state of the aforementioned indoor fan, ie 0min ^-1 , is not included in the limit value. The air conditioner according to claim 1, wherein the heat exchanger is the outdoor heat exchanger; further comprising: an indoor fan provided in the vicinity of the indoor heat exchanger; The indoor fan is driven at a rotational speed equal to or lower than a value calculated by dividing the sum of the upper limit value and the lower limit value of the rotational speed of the indoor fan by 2 during at least a part of the temperature rise control; the lower limit The value is the lower limit value of the rotational speed of the indoor fan when the controller drives the compressor during air-conditioning operation, and the lower limit value does not include 0 min ⁻¹ , which is a stopped state of the indoor fan. The air conditioner according to claim 1, wherein the heat exchanger is the indoor heat exchanger; and has: a heater, provided in the vicinity of the aforementioned indoor heat exchanger; and The drain pan is arranged on the lower side of the aforementioned indoor heat exchanger; The control unit energizes the heater after performing the process of bringing the indoor heat exchanger to a temperature below freezing point or a temperature below dew point temperature. The air conditioner according to claim 1, wherein the heat exchanger is the indoor heat exchanger; and has: The camera department, which takes pictures of the air-conditioned room; and The operation terminal is operated by the user; The said control part raises the temperature of the said indoor heat exchanger based on the imaging result of the said imaging part or the operation of the said operation terminal. The air conditioner according to claim 1, wherein the heat exchanger is the indoor heat exchanger; and has: a filter, arranged in the vicinity of the aforementioned indoor heat exchanger; and The filter cleaning part is used to clean the aforementioned filter; The control unit sets the frequency of the control to increase the temperature of the indoor heat exchanger to be lower than the frequency of cleaning the filter by the filter cleaning unit. The air conditioner as set forth in claim 1, comprising: An indoor temperature sensor for detecting the temperature of an air-conditioned room; and The outdoor temperature sensor detects the temperature of the outside air; The control unit does not perform control to increase the temperature of the heat exchanger when the detection value of the indoor temperature sensor or the outdoor temperature sensor is greater than or equal to a predetermined value. The air conditioner according to claim 1, further comprising: a heat exchanger temperature sensor for detecting the temperature of the heat exchanger; The control unit starts to bring the heat exchanger to a freezing point without increasing the temperature of the heat exchanger when the detection value of the heat exchanger temperature sensor has reached a predetermined value or more when the cleaning operation is performed. temperature below or below the dew point temperature.

Images