WO2020144797A1 - Air conditioner - Google Patents

Abstract

Provided is an air conditioner that cleans an indoor heat exchanger and prevents condensation from dripping. A control unit (30) for an air conditioner (100) performs a freezing process for causing an indoor heat exchanger (15) to function as an evaporator and to freeze. If the detected value of an indoor temperature sensor is equal to or greater than a first prescribed value, the control unit (30) either does not perform the freezing process, or shortens the freezing process duration time or decreases the rotational speed of a compressor motor (11a) during the freezing process even when performing the freezing process. The first prescribed value is lower than the upper limit for the set temperature that can be changed by a remote control during cooling operation or heating operation.

Description

Air conditioner

The present invention relates to an air conditioner.

As a technique for cleaning the indoor heat exchanger of the air conditioner, for example, in Patent Document 1, frosting and defrosting of the indoor heat exchanger are sequentially performed to remove dirt from the indoor heat exchanger. Is described.

JP, 2010-14288, A

By the way, if frost is formed on the indoor heat exchanger, the temperature of the air near the indoor unit may fall below the dew point, and the housing and various parts of the indoor unit may condense. For example, when dew condensation occurs on the outer surface of the housing of the indoor unit, the dew condensation water may drop (drip) under its own weight in some cases. Patent Document 1 does not describe measures against such a problem.

Therefore, an object of the present invention is to provide an air conditioner that cleans an indoor heat exchanger and further suppresses dew drop.

In order to solve the above problems, in the air conditioner according to the present invention, the control unit causes the indoor heat exchanger to function as an evaporator, performs a freezing process to freeze the indoor heat exchanger, and detects the indoor temperature sensor. When the value is equal to or more than the first predetermined value, the control unit does not perform the freezing process, or even when the freezing process is performed, the control value is less than the case where the detected value of the indoor temperature sensor is less than the first predetermined value. Also shortens the duration of the freezing process, or reduces the rotation speed of the motor of the compressor during the freezing process as compared to the case where the detection value of the indoor temperature sensor is less than the first predetermined value, The predetermined value of 1 is lower than the upper limit value of the set temperature that can be changed by the remote controller during the cooling operation or the heating operation.

Further, in the air conditioner according to the present invention, the control unit causes the indoor heat exchanger to function as an evaporator, performs a freezing process to freeze the indoor heat exchanger, and the detected value of the indoor temperature sensor is the first predetermined value. In the above case, the control unit performs the freezing process after performing the cooling operation or the dehumidifying operation, and the first predetermined value is higher than the upper limit value of the set temperature that can be changed by the remote controller during the cooling operation or the heating operation. Also decided to be low.

According to the present invention, it is possible to provide an air conditioner that cleans an indoor heat exchanger and further suppresses dew drop.

It is a block diagram of the air conditioner which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the indoor unit of the air conditioner which concerns on 1st Embodiment of this invention. It is a functional block diagram of the air conditioner concerning a 1st embodiment of the present invention. It is a flow chart of processing which a control part of an air harmony machine concerning a 1st embodiment of the present invention performs. In the air conditioner according to the first embodiment of the present invention, it is a moist air diagram in which a first predetermined value and an upper limit value regarding the indoor temperature are described. It is explanatory drawing regarding ON/OFF switching of the compressor and the indoor fan with which the air conditioner which concerns on 1st Embodiment of this invention is equipped. It is a flow chart of processing which a control part of an air harmony machine concerning a 2nd embodiment of the present invention performs. It is a flow chart of processing which a control part of an air harmony machine concerning a 3rd embodiment of the present invention performs. It is a flow chart of processing which a control part of an air harmony machine concerning a 4th embodiment of the present invention performs. It is a flow chart of processing which a control part of an air harmony machine concerning a 5th embodiment of the present invention performs. It is a map which shows the rotation speed of a compressor motor with which an air conditioner concerning a 5th embodiment of the present invention is equipped, and the 3rd predetermined value. It is a flow chart of processing which a control part of an air harmony machine concerning a 6th embodiment of the present invention performs. It is a functional block diagram of the air conditioner concerning a 7th embodiment of the present invention. It is a flow chart of processing which a control part of an air harmony machine concerning a 7th embodiment of the present invention performs.

«First embodiment»
<Structure of air conditioner>
FIG. 1 is a configuration diagram of an air conditioner 100 according to the first embodiment.
The solid line arrow in FIG. 1 indicates the flow of the refrigerant during the heating operation.
On the other hand, the broken line arrow in FIG. 1 indicates 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. Further, the air conditioner 100 includes an indoor heat exchanger 15, an indoor fan 16, and a four-way valve 17, in addition to the above-described configuration.

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. As shown in FIG. 1, the compressor 11 includes a compressor motor 11a that is a drive source.
The outdoor heat exchanger 12 is a heat exchanger that performs heat exchange between the refrigerant flowing through the heat transfer pipe (not shown) and the outside air sent from 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 that is a drive source, and is installed near the outdoor heat exchanger 12.
The expansion valve 14 is a valve that decompresses the refrigerant condensed in the "condenser" (one of the outdoor heat exchanger 12 and the indoor heat exchanger 15). 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 performs heat exchange between the refrigerant flowing through the heat transfer tube g (see FIG. 2) and the indoor air (air in the air-conditioned space) sent from the indoor fan 16. It is a vessel.
The indoor fan 16 is a fan that sends indoor air to the indoor heat exchanger 15. The indoor fan 16 has an indoor fan motor 16c (see FIG. 3), which is a drive source, and is installed near the indoor heat exchanger 15.

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. For example, during the cooling operation (see the dashed arrow in FIG. 1), in the refrigerant circuit Q, the compressor 11, the outdoor heat exchanger 12 (condenser), the expansion valve 14, and the indoor heat exchanger 15 (evaporator). Refrigerant circulates in the refrigeration cycle through the.

On the other hand, during the heating operation (see the solid arrow in FIG. 1), in the refrigerant circuit Q, the compressor 11, the indoor heat exchanger 15 (condenser), the expansion valve 14, and the outdoor heat exchanger 12 (evaporator). Refrigerant circulates in the refrigeration cycle through the.

That is, in the refrigerant circuit Q in which the refrigerant circulates sequentially through the compressor 11, the “condenser”, the expansion valve 14, and the “evaporator”, one of the above-mentioned “condenser” and “evaporator” is the outdoor heat. It is the exchanger 12 and the other is the indoor heat exchanger 15.

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 installed in the outdoor unit Uo. On the other hand, the indoor heat exchanger 15 and the indoor fan 16 are installed in the indoor unit Ui.

FIG. 2 is a vertical cross-sectional view of the indoor unit Ui.
As shown in FIG. 2, the indoor unit Ui includes a drain pan 18, a housing base 19, and filters 20a and 20b in addition to the indoor heat exchanger 15 and the indoor fan 16 described above. Further, the indoor unit Ui includes a front panel 21, a left/right airflow direction plate 22, and a vertical airflow direction plate 23.

The indoor heat exchanger 15 includes a plurality of fins f and a plurality of heat transfer tubes g that penetrate the fins f. Explaining from another viewpoint, the indoor heat exchanger 15 includes a front indoor heat exchanger 15a arranged on the front side of the indoor fan 16 and a rear indoor heat exchanger 15b arranged on the rear side of the indoor fan 16. Equipped with. In the example of FIG. 2, the upper end of the front indoor heat exchanger 15a and the upper end of the rear indoor heat exchanger 15b are connected in an inverted V shape.

The indoor fan 16 is, for example, a cylindrical cross-flow fan, and is installed near the indoor heat exchanger 15. The indoor fan 16 includes a plurality of fan blades 16a, an annular partition plate 16b installed on the fan blades 16a, and an indoor fan motor 16c (see FIG. 3) that is a drive source.

The drain pan 18 receives the condensed water of the indoor heat exchanger 15, and is installed below the indoor heat exchanger 15.
The housing base 19 is a housing in which devices such as the indoor heat exchanger 15 and the indoor fan 16 are installed.

The filters 20a and 20b are for collecting dust from the air directed to the indoor heat exchanger 15 as the indoor fan 16 is driven. One filter 20a is arranged on the front side of the indoor heat exchanger 15, and the other filter 20b is arranged on the upper side of the indoor heat exchanger 15.

The front panel 21 is a panel installed so as to cover the filter 20a on the front side, and is rotatable frontward about its lower end. The front panel 21 may not rotate.
The left-right airflow direction plate 22 is a plate-shaped member that adjusts the left-right airflow direction of the air blown into the room. The left/right airflow direction plate 22 is arranged in the blowout air passage h3, and is rotated in the left/right direction by the left/right airflow direction plate motor 24 (see FIG. 3).

The vertical wind direction plate 23 is a plate-shaped member that adjusts the vertical wind direction of the air blown into the room. The vertical wind direction plate 23 is arranged near the air outlet h4, and is rotated in the vertical direction by the vertical wind direction plate motor 25 (see FIG. 3).

The air sucked through the air suction ports h1 and h2 exchanges heat with the refrigerant flowing through the heat transfer tube g of the indoor heat exchanger 15, and the heat-exchanged air is guided to the blowout air passage h3. Then, the air flowing through the blowout air passage h3 is guided in a predetermined direction by the left/right airflow direction plate 22 and the up/down airflow direction plate 23, and is further blown out into the room through the air outlet h4.

Note that most of the dust that goes toward the air inlets h1 and h2 with the flow of air is collected by the filters 20a and 20b. However, since fine dust may pass through the filters 20a and 20b and adhere to the indoor heat exchanger 15, it is desirable to regularly clean the indoor heat exchanger 15. Therefore, in the present embodiment, the indoor heat exchanger 15 is frozen and frosted, and then the indoor heat exchanger 15 is thawed and washed. Hereinafter, a series of processes including freezing of the indoor heat exchanger 15 will be referred to as “freezing cleaning” of the indoor heat exchanger 15.

FIG. 3 is a functional block diagram of the air conditioner 100.
The indoor unit Ui shown in FIG. 3 includes a remote control transmission/reception unit 26, an environment detection unit 27, and an indoor control circuit 31 in addition to the above-described components.
The remote controller transceiver 26 exchanges predetermined information with the remote controller 40 by infrared communication or the like.

The environment detection unit 27 includes an indoor temperature sensor 27a and an indoor heat exchanger temperature sensor 27b.
The indoor temperature sensor 27a is a sensor that detects the temperature of the room (air-conditioned space), and is installed, for example, on the air intake side of the filters 20a and 20b (see FIG. 2).

The indoor heat exchanger temperature sensor 27b is a sensor that detects the temperature of the indoor heat exchanger 15 (see FIG. 2), and is installed in the indoor heat exchanger 15.
The detection values of the indoor temperature sensor 27a and the indoor heat exchanger temperature sensor 27b are output to the indoor control circuit 31.

In the example of FIG. 3, the air conditioner 100 does not include a humidity sensor (not shown) that detects indoor humidity (for example, relative humidity), but the present invention is not limited to this. Absent.

Although not shown, the indoor control circuit 31 includes electronic circuits such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various interfaces. Then, the program stored in the ROM is read and expanded in the RAM, and the CPU executes various processes.

As shown in FIG. 3, the indoor control circuit 31 includes a storage unit 31a and an indoor control unit 31b.
In the storage unit 31a, in addition to a predetermined program, data received via the remote controller transmission/reception unit 26, detection values of each sensor, and the like are stored.
The indoor control unit 31b controls the indoor fan motor 16c, the left/right wind direction plate motor 24, the up/down air direction plate motor 25, and the like based on the data stored in the storage unit 31a.

The outdoor unit Uo includes an outdoor temperature sensor 28 and an outdoor control circuit 32 in addition to the above-described configuration.
The outdoor temperature sensor 28 is a sensor that detects an outdoor temperature, and is installed at a predetermined location of the outdoor unit Uo. Although not shown in FIG. 3, the outdoor unit Uo also includes a sensor that detects the discharge temperature of the compressor 11 (see FIG. 1). The detection value of each of these sensors is output to the outdoor control circuit 32.

Although not shown, the outdoor control circuit 32 is configured to include electronic circuits such as a CPU, ROM, RAM, and various interfaces, and is connected to the indoor control circuit 31 via a communication line. As shown in FIG. 3, the outdoor control circuit 32 includes a storage unit 32a and an outdoor control unit 32b.

The storage unit 32a stores a predetermined program and data received from the indoor control circuit 31. The outdoor control unit 32b controls the compressor motor 11a, the outdoor fan motor 13a, the expansion valve 14 and the like based on the data stored in the storage unit 32a. The “control unit 30” that controls at least the compressor 11 (see FIG. 1) and the expansion valve 14 is configured to include an indoor control circuit 31 and an outdoor control circuit 32.
Next, the processing of the control unit 30 regarding the freeze cleaning of the indoor heat exchanger 15 will be described with reference to FIG.

<Processing of control unit>
FIG. 4 is a flowchart of processing executed by the control unit 30 of the air conditioner 100 according to the first embodiment (see FIG. 3 as needed).
Although omitted in FIG. 4, for example, when the sum of the execution times of the air conditioning operation accumulated from the end of the previous freeze washing (S101 to S104) reaches a predetermined time, the control unit 30 causes the control unit 30 to perform the step S101. The process of may be started. Further, when the user presses the freeze washing button (not shown) of the remote controller 40, the control unit 30 may start the process of step S101.

In step S101, the control unit 30 determines whether the indoor temperature T, which is the detection value of the indoor temperature sensor 27a, is equal to or higher than the first predetermined value T1. Here, the first predetermined value T1 is a threshold value that serves as a criterion for determining whether or not to freeze the indoor heat exchanger 15 (S102), and is set in advance.

Further, it is preferable that the control unit 30 drives the indoor fan 16 when the indoor temperature (the temperature of the air-conditioned space) is detected using the indoor temperature sensor 27a (see FIG. 3). As a result, the air in the room is agitated, so that the error when the room temperature sensor 27a detects the room temperature can be reduced.

When the indoor temperature T is equal to or higher than the first predetermined value T1 in step S101 (S101: Yes), the control unit 30 ends the series of processes without performing the freezing process (S102) of the indoor heat exchanger 15 ( END). Even when the room temperature T is equal to or higher than the first predetermined value T1, the freezing process may be performed, but an example thereof will be described later (second and third embodiments).
On the other hand, when the indoor temperature T is lower than the first predetermined value T1 in step S101 (S101: No), the control unit 30 freezes the indoor heat exchanger 15 in step S102 (freezing process).

By the way, in the air conditioner 100, the upper limit value and the lower limit value of the set temperature (temperature set value of the air conditioning target space) that can be changed by the user operating the remote controller 40 are preset and stored in the storage unit 31a. For example, during cooling operation or heating operation, the user can change the set temperature within the range of 10° C. (lower limit value T _min ) or more and 32° C. (upper limit value T _MAX ) or less by operating the remote controller 40. It is like this.

In the present embodiment, the first predetermined value T1 used in the determination process of step S101 is higher than the upper limit value T _MAX (for example, 32° C.) of the set temperature that can be changed by the remote controller 40 during the cooling operation or the heating operation. It is preset as a low value. In the present embodiment, as an example, the first predetermined value T1 will be described as being set at 30°C.

FIG. 5 is a moist air diagram in which the first predetermined value T1 and the upper limit value T _MAX related to the indoor temperature are described (see FIG. 3 as appropriate).
The horizontal axis of FIG. 5 represents the dry-bulb temperature of air (that is, the room temperature). The vertical axis of FIG. 5 is the absolute humidity of air. The upward-sloping curve (solid line and broken line) in FIG. 5 is a group of points where the relative humidity of air (for example, 80%) is equal. In the example of FIG. 5, the upper limit value T _MAX of the set temperature that can be changed by the remote controller 40 during the cooling operation or the heating operation is 32° C., and the first predetermined value T1 is set to 30° C.

For example, in a state H in which the dry-bulb temperature of the room air is higher than the first predetermined value T1 and the relative humidity is 80%, the absolute humidity (mass of water vapor for 1 kg of dry air) is about 0.029 [. kg/kg (DA)].
If the indoor heat exchanger 15 is frozen in the air in the state H where the absolute humidity is relatively high, the air around the indoor unit Ui is cooled accordingly. As a result, dew condensation may occur on the inner and outer surfaces of the housing base 19 (see FIG. 2), and depending on the case, dew drop may occur. Note that the higher the indoor temperature T, the larger the amount of water vapor that can be contained in the indoor air (absolute humidity when the relative humidity is 100%), and dew drops easily during freezing of the indoor heat exchanger 15. Become.

For example, under the condition that the dry-bulb temperature of the room air is 30° C. (first predetermined value T1) and the relative humidity exceeds 100%, the dew drop may occur.
Therefore, in the present embodiment, when the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes in FIG. 4), the control unit 30 does not perform the freezing process (S102) of the indoor heat exchanger 15. I am trying. That is, when the indoor temperature T is equal to or higher than the first predetermined value T1, the control unit 30 takes into account the possibility that the absolute humidity of the indoor air is high (that is, the dew drop in the indoor unit Ui), and as a precaution. I do not freeze it. This can prevent dew drop of the indoor unit Ui.

When the room temperature T is equal to or higher than the first predetermined value T1, the control unit 30 shortens the duration of the freezing process or reduces the rotation speed of the compressor motor 11a (see FIG. 3) during the freezing process. However, this will be described in the second and third embodiments.

On the other hand, in FIG. 5, when the dry-bulb temperature of the indoor air is 20° C. lower than the first predetermined value T1 and the relative humidity is 80% in the state J, the absolute humidity is about 0.012 [kg/kg( DA)]. Thus, in the air having a relatively low absolute humidity, even if the indoor heat exchanger 15 is frozen, there is almost no possibility that dew drops will occur in the indoor unit Ui.

By the way, even when the dry-bulb temperature is 20°C and the relative humidity is 100% in state K, the absolute humidity is about 0.015 [kg/kg (DA)], which is not so high. That is, when the dry-bulb temperature is 20° C., regardless of whether the relative humidity is high or low, there is almost no possibility that dew drops will occur in the indoor unit Ui during freezing of the indoor heat exchanger 15. As described above, the first predetermined value T1 is preset so that the indoor unit Ui does not have dew drop regardless of whether the relative humidity is high or low.

Returning to FIG. 4 again, the description will be continued.
When the indoor temperature T is lower than the first predetermined value T1 in step S101 (S101: No), the control unit 30 freezes the indoor heat exchanger 15 in step S102. That is, the control unit 30 causes the indoor heat exchanger 15 to function as an evaporator, causes moisture in the air to frost on the indoor heat exchanger 15, and freezes the indoor heat exchanger 15.

Describing this step S102 in further detail, for example, the control unit 30 drives the compressor 11 (see FIG. 1) by making the opening of the expansion valve 14 (see FIG. 1) smaller than that during the cooling operation. As a result, a low-pressure refrigerant having a low evaporation temperature flows into the indoor heat exchanger 15, so that moisture in the air frosts on the indoor heat exchanger 15, and frost and ice on the surface of the indoor heat exchanger 15 Grows. The opening degree of the expansion valve 14 in the freezing process may be substantially the same as the opening degree during the cooling operation.

FIG. 6 is an explanatory diagram regarding ON/OFF switching of the compressor 11 and the indoor fan 16 (see FIG. 1 as appropriate).
The horizontal axis of FIG. 6 is time. Further, the vertical axis of FIG. 6 shows ON/OFF of the compressor 11 and ON/OFF of the indoor fan 16. In the example of FIG. 6, the compressor 11 and the indoor fan 16 are driven (that is, in the ON state) after the predetermined air conditioning operation is performed until time t1. After that, the compressor 11 and the indoor fan 16 are stopped at times t1 to t2, and then the indoor heat exchanger 15 is frozen at times t2 to t3 (step S102 in FIG. 4).

In the example of FIG. 6, the indoor fan 16 is stopped while the indoor heat exchanger 15 is frozen. As a result, cold air is not blown into the room, so that the indoor heat exchanger 15 can be frozen without impairing the comfort of the user. The processing after time t3 will be described later.
Incidentally, during freezing of the indoor heat exchanger 15, the control unit 30 may drive the indoor fan 16 without stopping the indoor fan 16.

Next, in step S103 of FIG. 4, the control unit 30 defrosts the indoor heat exchanger 15. For example, the control unit 30 puts the devices such as the indoor fan 16 and the compressor 11 in a stopped state. As a result, the frost and ice in the indoor heat exchanger 15 are naturally thawed at room temperature, and a large amount of water flows down to the drain pan 18 along the fins f (see FIG. 2). As a result, the dust attached to the indoor heat exchanger 15 is washed away.

Next, in step S104 of FIG. 4, the control unit 30 dries the indoor heat exchanger 15. In the example of FIG. 6, after the indoor heat exchanger 15 is thawed, the heating operation and the blowing operation are sequentially performed as the “drying” operation from time t4 to time t6. As a result, the growth of fungi such as mold in the indoor unit Ui can be suppressed. After performing the drying operation in step S104, the control unit 30 ends a series of processes regarding freeze washing (END).

Although not shown in FIG. 4, the indoor temperature T (the detection value of the indoor temperature sensor 27a) is a second predetermined value T2 (for example, 10° C.) lower than the first predetermined value T1 (for example, 30° C.). In the following cases, it is preferable that the control unit 30 not perform the freezing process (S102). This is because if the room temperature T is too low, the amount of water that can be contained in the room air per unit volume is too small, and frost formation on the indoor heat exchanger 15 is difficult to proceed during the freezing process (S102). ..

The second predetermined value T2 is preset as a value lower than the first predetermined value T1 based on the time required for the freezing process of the indoor heat exchanger 15 and the power consumption. Further, the second predetermined value T2 may be equal to or higher than the lower limit value T _min (for example, 10° C.) of the set temperature that can be changed by the remote controller 40 during the cooling operation or the heating operation. Thereby, even if the room temperature T is within the range of the set temperature that can be changed by the remote controller 40, if the numerical value is too low, the freezing process can be appropriately stopped. The size of the second predetermined value T2 is not limited to the lower limit value T _min or more, and may be less than the lower limit value T _min .

Further, when the indoor temperature T (the detection value of the indoor temperature sensor 27a) is equal to or higher than the first predetermined value T1, the control unit 30 preferably performs the cooling operation or the air blowing operation when the freezing process (S102) is not performed. .. For example, when the user presses the freeze washing button (not shown) of the remote controller 40 and the room temperature T is equal to or higher than the first predetermined value T1, the control unit 30 replaces the freeze washing and performs the cooling operation. Or, perform blow operation.

Due to this, in the cooling operation, the indoor heat exchanger 15 is washed away by the condensed water generated in the indoor heat exchanger 15. Further, in the blowing operation, the inside of the indoor unit Ui is dried, so that the indoor unit Ui is in a clean state. In this way, the indoor unit Ui can be cleaned by a method different from the freezing process. Further, compared to the case where the operating sound of the air conditioner 100 does not occur even if the remote controller 40 is operated, the user's discomfort can be reduced.

<Effect>
According to the first embodiment, when the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes in FIG. 4), the control unit 30 does not perform the freezing process on the indoor heat exchanger 15 (END). As a result, it is possible to prevent freezing and washing from being performed in a state where the indoor air contains a large amount of water. Therefore, it is possible to suppress the dew drop in the indoor unit Ui during the freezing of the indoor heat exchanger 15. As described above, according to the first embodiment, it is possible to provide the air conditioner 100 in which the indoor heat exchanger 15 is in a clean state and the dew drop is suppressed.

Further, the first predetermined value T1 used for determining whether or not the indoor heat exchanger 15 is frozen (S101 in FIG. 4) is lower than the upper limit value of the set temperature that can be changed by the remote controller 40. Therefore, for example, the first predetermined value T1 is appropriately set on the basis of the absolute humidity of the air whose absolute dew point is the first predetermined value T1 (absolute humidity when the relative humidity is 100%). Of the indoor unit Ui can be suppressed.

Further, as described above, the detected value of the indoor temperature is used to determine whether or not the freezing process of the indoor heat exchanger 15 is performed. On the other hand, since it is not particularly necessary to detect the indoor humidity, the indoor heat exchanger 15 can be frozen and washed even with an inexpensive air conditioner in which the indoor unit Ui is not provided with a humidity sensor.

«Second embodiment»
The second embodiment is different from the first embodiment in that when the room temperature T is equal to or higher than the first predetermined value T1, the control unit 30 makes the duration of the freezing process shorter than usual. That is, in the first embodiment, when the indoor temperature T is equal to or higher than the first predetermined value T1, the control unit 30 does not perform the freezing process, but in the second embodiment, the indoor temperature T is the first predetermined value T1. Even if the above is the case, the control unit 30 performs the freezing process.
Others (configuration of the air conditioner 100, etc.: see FIGS. 1 to 3) are the same as in the first embodiment. Therefore, only the parts different from the first embodiment will be described, and the description of the overlapping parts will be omitted.

FIG. 7 is a flowchart of processing executed by the control unit 30 of the air conditioner 100 according to the second embodiment (see FIG. 3 as needed).
Note that steps S101 to S104 in FIG. 7 are the same as those in the first embodiment (see FIG. 4), and therefore description thereof will be omitted. In step S101, when the indoor temperature T that is the detection value of the indoor temperature sensor 27a is equal to or higher than the first predetermined value T1 (S101: Yes), the process of the control unit 30 proceeds to step S201.

In step S201, the control unit 30 sets the freezing time of the indoor heat exchanger 15 to be short. That is, the control unit 30 shortens the duration of the freezing process (S202) of the indoor heat exchanger 15 as compared with the case where the indoor temperature T (the detection value of the indoor temperature sensor 27a) is less than the first predetermined value T1.

Next, in step S202, the control unit 30 freezes the indoor heat exchanger 15. That is, the control unit 30 performs the freezing process of step S202 for a shorter period of time than normal (S102). As a result, even in a situation where the amount of water contained in the indoor air per unit volume is large, the indoor heat exchanger 15 can be frozen while suppressing dew drop in the indoor unit Ui. After freezing the indoor heat exchanger 15 (S202), the control unit 30 sequentially performs thawing (S103) and drying (S104) of the indoor heat exchanger 15 and ends the series of processes (END).

<Effect>
According to the second embodiment, when the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes in FIG. 7), the control unit 30 freezes the indoor heat exchanger 15 even when performing the freezing process. The time is set to be short (S201). Accordingly, even when the indoor temperature is relatively high, the indoor heat exchanger 15 can be frozen and washed while suppressing the drooling in the indoor unit Ui.

<<Third Embodiment>>
In the third embodiment, like the second embodiment, the control unit 30 performs the freezing process even when the room temperature T is equal to or higher than the first predetermined value T1, but in the third embodiment, the compression during the freezing process is performed. The difference from the second embodiment is that the rotation speed of the machine motor 11a is made lower than usual. Note that the other components (such as the configuration of the air conditioner 100: see FIGS. 1 to 3) are the same as in the second embodiment. Therefore, only the parts different from the second embodiment will be described, and the description of the overlapping parts will be omitted.

FIG. 8 is a flowchart of processing executed by the control unit 30 of the air conditioner 100 according to the third embodiment (see FIG. 3 as needed).
Note that steps S101 to S104 in FIG. 8 are the same as those in the first embodiment (see FIG. 4), and therefore description thereof will be omitted. In step S101, when the indoor temperature T which is the detection value of the indoor temperature sensor 27a is equal to or higher than the first predetermined value T1 (S101: Yes), the process of the control unit 30 proceeds to step S301.

In step S301, the control unit 30 sets the rotation speed of the compressor motor 11a to be low. That is, the control unit 30 reduces the rotation speed of the compressor motor 11a during the freezing process (S302) more than when the indoor temperature T (the detection value of the indoor temperature sensor 27a) is less than the first predetermined value T1.

Next, in step S302, the control unit 30 freezes the indoor heat exchanger 15. That is, the control unit 30 drives the compressor motor 11a at a lower rotation speed than in the normal freezing process to freeze the indoor heat exchanger 15.

During the freezing process, the control unit 30 may rotate the compressor motor 11a at a constant speed, or may perform feedback control. When the control unit 30 performs feedback control of the compressor motor 11a, driving the compressor motor 11a at a "smaller rotation speed" than in the normal freezing process means the following.
That is, of the plurality of sensors (indoor temperature sensor 27a, outdoor temperature sensor 28, discharge temperature sensor (not shown), etc.) used for feedback control of the compressor motor 11a during the freezing process, each of the sensors other than the indoor temperature sensor 27a. When the detected value is a predetermined value and the detected value of the indoor temperature sensor 27a is less than the first predetermined value T1, it is assumed that the control unit 30 drives the compressor motor 11a at a predetermined rotation speed. On the other hand, when the detection value of each sensor other than the indoor temperature sensor 27a is the above-described predetermined value and the detection value of the indoor temperature sensor 27a is the first predetermined value T1 or more, the control unit 30 turns on the compressor motor 11a. It is driven at a rotation speed lower than the above-mentioned predetermined rotation speed.

As a result, the flow rate of the refrigerant circulating in the refrigerant circuit Q (see FIG. 1) is reduced during freezing of the indoor heat exchanger 15, so that the heat exchange amount between the refrigerant and the air is smaller than that during normal freezing (S102). Also becomes smaller. Therefore, even in a situation where the amount of water contained in the indoor air per unit volume is large, the indoor heat exchanger 15 can be frozen while suppressing the dew drop in the indoor unit Ui.

After freezing the indoor heat exchanger 15 in this way (S302), the control unit 30 sequentially performs thawing (S103) and drying (S104) of the indoor heat exchanger 15 and ends a series of processes ( END).

<Effect>
According to the third embodiment, when the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes in FIG. 8), the control unit 30 freezes the indoor heat exchanger 15 even when performing the freezing process. The rotation speed of the compressor motor 11a at the time of making it lower than usual (S301). Accordingly, even when the indoor temperature is relatively high, the indoor heat exchanger 15 can be frozen and washed while suppressing the drooling in the indoor unit Ui.

«Fourth Embodiment»
In the fourth embodiment, the point that the control unit 30 freezes the indoor heat exchanger 15 when the cooling operation or the dehumidifying operation has already been performed even if the indoor temperature T is the first predetermined value T1 or more is the first point. It differs from the embodiment. Others (configuration of the air conditioner 100, etc.: see FIGS. 1 to 3) are the same as in the first embodiment. Therefore, only the parts different from the first embodiment will be described, and the description of the overlapping parts will be omitted.

FIG. 9 is a flowchart of processing executed by the control unit 30 of the air conditioner 100 according to the fourth embodiment (see FIG. 3 as appropriate).
Note that steps S101 to S104 in FIG. 9 are the same as those in the first embodiment (see FIG. 4), and therefore description thereof will be omitted. In step S101, when the indoor temperature T that is the detection value of the indoor temperature sensor 27a is equal to or higher than the first predetermined value T1 (S101: Yes), the process of the control unit 30 proceeds to step S401.

In step S401, the control unit 30 determines whether the cooling operation or the dehumidifying operation has been performed prior to freezing the indoor heat exchanger 15. Specifically, the control unit 30 determines whether or not the operation mode of the air conditioning operation performed most recently in step S401 is the cooling operation or the dehumidifying operation. For example, when the cooling operation is performed, the water contained in the air is condensed in the indoor heat exchanger 15, and the condensed water is sequentially passed through the drain pan 18 (see FIG. 2) and the drain hose (not shown). , Discharged to the outside. Therefore, the amount of water contained in the indoor air per unit volume is often reduced after the cooling operation. The same applies when a dehumidifying operation (so-called cooling dehumidification or reheat dehumidification) is performed.

Note that in step S401, in addition to the condition that the operation mode of the most recent air conditioning operation is the cooling operation or the dehumidifying operation, a condition that the duration of the cooling operation or the like is a predetermined time or more may be added. Good.
Further, when the operation mode of the most recent air conditioning operation is the cooling operation or the dehumidifying operation, a condition that the elapsed time from the end of the cooling operation or the like is within a predetermined time may be added.

Further, in step S401, the control unit 30 may perform the following processing. For example, when the cooling operation or the dehumidifying operation is performed for a predetermined time or more, the control unit 30 sets a permission flag (not shown) indicating that the freeze cleaning may be performed thereafter. The control unit 30 may freeze the indoor heat exchanger 15 when the permission flag is raised in step S401.

In step S401, when the cooling operation or the dehumidifying operation is performed before freezing the indoor heat exchanger 15 (S401: Yes), the process of the control unit 30 proceeds to step S102. In step S102, the control unit 30 freezes the indoor heat exchanger 15. That is, with respect to the freezing time of the indoor heat exchanger 15 and the rotation speed of the compressor motor 11a, the control unit 30 executes the freezing process (S102) as in the case where the indoor temperature T is less than the first predetermined value T1.

As described above, since the cooling operation or the dehumidifying operation has already been performed (S401: Yes), even if the room temperature T is equal to or higher than the first predetermined value T1 (S101: Yes), the indoor air per unit volume becomes It does not contain much water. Therefore, during the freezing process of the indoor heat exchanger 15 (S102), there is almost no possibility of dew drop in the indoor unit Ui.

After freezing the indoor heat exchanger 15 in step S102, the control unit 30 sequentially performs thawing (S103) and drying (S104) of the indoor heat exchanger 15 and ends a series of processes (END).

On the other hand, in step S401, when the cooling operation is not performed prior to the freezing of the indoor heat exchanger 15 and the dehumidifying operation is not performed (S401: No), the control unit 30 causes the indoor heat exchanger 15 to operate. The series of processes is ended (END) without performing the freezing process (S102). This is because, if the indoor heat exchanger 15 is frozen in a state where the indoor air per unit volume contains a large amount of water, there is a possibility that the indoor unit Ui may be exposed to dew.

<Effect>
According to the fourth embodiment, even when the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes), when the cooling operation or the dehumidifying operation is performed prior to the freezing of the indoor heat exchanger 15 ( (S401: Yes), the control unit 30 freezes the indoor heat exchanger 15 (S102). Thus, the indoor heat exchanger 15 can be frozen and washed while the amount of water contained in the indoor air per unit volume is not so large.

<<Fifth Embodiment>>
In the fifth embodiment, when the temperature difference between the indoor temperature and the temperature of the indoor heat exchanger 15 is equal to or less than a third predetermined value in the cooling operation or the dehumidifying operation performed prior to the freezing of the indoor heat exchanger 15, The difference from the fourth embodiment is that the control unit 30 does not freeze the indoor heat exchanger 15. The other points are the same as those in the fourth embodiment. Therefore, only the parts different from the fourth embodiment will be described, and the description of the overlapping parts will be omitted.

FIG. 10 is a flowchart of processing executed by the control unit 30 of the air conditioner 100 according to the fifth embodiment (see FIG. 3 as appropriate).
Note that steps S101 to S104 and S401 in FIG. 10 are the same as those in the fourth embodiment (see FIG. 9), so description thereof will be omitted. In step S101, when the indoor temperature T that is the detection value of the indoor temperature sensor 27a is equal to or higher than the first predetermined value T1 (S101: Yes), the process of the control unit 30 proceeds to step S401.

In step S401, the control unit 30 determines whether the cooling operation or the dehumidifying operation has been performed prior to freezing the indoor heat exchanger 15. When the cooling operation or the dehumidifying operation is performed before freezing the indoor heat exchanger 15 (S401: Yes), the process of the control unit 30 proceeds to step S501.

In step S501, the control unit 30 determines whether or not the temperature difference ΔT (=T−T _evp ) between the indoor temperature T and the temperature T _evp of the indoor heat exchanger 15 is the third predetermined value ΔT3 or less. That is, the control unit 30 sets the difference ΔT of the indoor temperature T to the temperature T _evp of the indoor heat exchanger 15 when the cooling operation or the dehumidifying operation is performed prior to the freezing process (S102) to be the third predetermined value ΔT3 or less. Or not.
The above-mentioned third predetermined value ΔT3 is a threshold value that serves as a criterion for determining whether or not to freeze the indoor heat exchanger 15 (S102), and is set in advance. The temperature T _evp of the indoor heat exchanger 15 is detected by the indoor heat exchanger temperature sensor 27b (see FIG. 3).

The temperatures T and T _evp in step S501 may be detected values when the cooling operation or the like is performed (for example, after a predetermined time has elapsed from the start of the cooling operation or the like), or the time average thereof. May be Further, each of the temperatures T and T _evp may be a detected value at a predetermined timing from the end of the cooling operation or the like to the start of the process of step S401, or may be the time average thereof.

In step S501, when the temperature difference ΔT between the indoor temperature T and the temperature T _evp of the indoor heat exchanger 15 is the third predetermined value ΔT3 or less (S501: Yes), the control unit 30 freezes the indoor heat exchanger 15. A series of processing is ended without performing the processing (S102) (END).
Note that the greater the amount of water contained in the room air per unit volume, the greater the proportion of latent heat in the amount of heat exchange between the room air and the refrigerant. That is, since the refrigerant absorbs the heat required to condense the moisture contained in the indoor air, it becomes difficult for the indoor heat exchanger 15 to cool. As a result, the temperature difference ΔT (=T−T _evp ) between the indoor temperature T and the temperature T _evp of the indoor heat exchanger 15 tends to be small.

On the other hand, in step S501, when the temperature difference ΔT between the indoor temperature T and the temperature T _evp of the indoor heat exchanger 15 is larger than the third predetermined value ΔT3 (S501: No), the process of the control unit 30 proceeds to step S102. .. For example, when the cooling operation is performed in a situation where the amount of water contained in the indoor air per unit volume is not so large, the ratio of latent heat in the amount of heat exchange between the refrigerant and the air is relatively small. That is, since the amount of heat absorbed by the refrigerant from the water contained in the indoor air is relatively small, the indoor heat exchanger 15 is easily cooled. As a result, the temperature difference ΔT has a relatively large value.

Then, after freezing the indoor heat exchanger 15 in step S102, the control unit 30 sequentially performs thawing (S103) and drying (S104) of the indoor heat exchanger 15, and ends the series of processes (END). ..

FIG. 11 is a map showing the relationship between the rotation speed of the compressor motor 11a and the third predetermined value ΔT3.
The horizontal axis of FIG. 11 represents the rotation speed of the compressor motor 11a during the cooling operation or the dehumidifying operation performed prior to the freezing process. The vertical axis of FIG. 11 is the above-mentioned third predetermined value ΔT3 (S501 of FIG. 10).

As shown in FIG. 11, the third predetermined value ΔT3 is set corresponding to the rotation speed n of the compressor motor 11a in the cooling operation or the dehumidifying operation performed prior to the freezing process. For example, when the compressor motor 11a is driven at the rotation speed n _p during the cooling operation, the control unit 30 sets the third predetermined value ΔT3 _p corresponding to the rotation speed n _p .

Further, it is preferable that the third predetermined value ΔT3 is larger as the rotation speed of the compressor motor 11a in the cooling operation or the dehumidifying operation is higher. This is because as the rotation speed of the compressor motor 11a increases, the flow rate of the refrigerant circulating in the refrigerant circuit Q (see FIG. 1) increases, and the indoor heat exchanger 15 (evaporator) becomes easier to cool.

Note that, as the rotation speed of the compressor motor 11a, an average rotation speed value of the compressor motor 11a when the cooling operation or the like is performed may be used. Data corresponding to the straight line m in FIG. 11 is stored in advance in the storage unit 31a (see FIG. 3) as a mathematical expression or a data table.

<Effect>
According to the fifth embodiment, even when the cooling operation or the dehumidifying operation is performed before the freezing process of the indoor heat exchanger 15 (S401: Yes in FIG. 10), the indoor temperature T and the temperature T of the indoor heat exchanger 15 are increased. _When the temperature difference ΔT from evp is equal to or smaller than the third predetermined value ΔT3 (S501: Yes), the control unit 30 does not freeze the indoor heat exchanger 15. Accordingly, when the indoor air per unit volume contains a relatively large amount of water, the indoor heat exchanger 15 is not frozen, so that it is possible to prevent dew drop in the indoor unit Ui.

«Sixth Embodiment»
The sixth embodiment is different from the first embodiment in that when the indoor temperature T is equal to or higher than the first predetermined value T1, the controller 30 freezes the indoor heat exchanger 15 after performing the cooling operation. There is. Others (configuration of the air conditioner 100, etc.: see FIGS. 1 to 3) are the same as in the first embodiment. Therefore, only the parts different from the first embodiment will be described, and the description of the overlapping parts will be omitted.

FIG. 12 is a flowchart of processing executed by the control unit 30 of the air conditioner 100 according to the sixth embodiment (see FIG. 3 as needed).
Note that steps S101 to S104 in FIG. 12 are the same as those in the first embodiment (see FIG. 4), so description thereof will be omitted. In step S101, when the indoor temperature T that is the detection value of the indoor temperature sensor 27a is equal to or higher than the first predetermined value T1 (S101: Yes), the process of the control unit 30 proceeds to step S601.

In step S601, the control unit 30 executes a cooling operation. Thereby, the indoor heat exchanger 15 functions as an evaporator, and the water contained in the air taken into the indoor unit Ui is condensed in the indoor heat exchanger 15. Then, the condensed water of the indoor heat exchanger 15 is discharged to the outside through the drain pan 18 (see FIG. 2) and the drain hose (not shown) in order. As a result, the amount of water contained in the indoor air per unit volume is reduced, so that it is possible to suppress the dew drop in the indoor unit Ui during the subsequent freezing process (S102).

Next, in step S102, the control unit 30 freezes the indoor heat exchanger 15. As described above, since the cooling operation is performed before freezing the indoor heat exchanger 15 (S601), there is almost no possibility that the indoor unit Ui will have dew drop while the indoor heat exchanger 15 is freezing. After freezing the indoor heat exchanger 15 in step S102, the control unit 30 sequentially performs thawing (S103) and drying (S104) of the indoor heat exchanger 15 and ends the series of processes (END).

The control unit 30 may perform the dehumidifying operation instead of the cooling operation in step S601. Even in such a dehumidifying operation, the amount of water contained in the indoor air can be reduced, as in the cooling operation.

<Effect>
According to the sixth embodiment, when the indoor temperature T (the detection value of the indoor temperature sensor 27a) is the first predetermined value T1 or more (S101: Yes), the control unit 30 performs the cooling operation or the dehumidifying operation (S601). After that, the indoor heat exchanger 15 is frozen (S102). Thereby, the control unit 30 can perform the freezing process (S102) of the indoor heat exchanger 15 in a state where the amount of water contained in the indoor air per unit volume is reduced. As a result, it is possible to appropriately suppress dew drop in the indoor unit Ui during the freezing process.

<<Seventh Embodiment>>
The seventh embodiment is different from the first embodiment in that the control unit 30 determines whether to freeze the indoor heat exchanger 15 based on the outdoor humidity based on the weather information. The other points are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described, and the description of the overlapping parts will be omitted.

FIG. 13 is a functional block diagram of an air conditioner 100A according to the seventh embodiment.
As shown in FIG. 13, the indoor unit UAi of the air conditioner 100A includes a weather information acquisition unit 29 in addition to the configuration described in the first embodiment (see FIG. 3). The weather information acquisition unit 29 may be provided in the outdoor unit Uo instead of the indoor unit UAi.
The weather information acquisition unit 29 has a function of acquiring weather information including outdoor humidity near the air conditioner 100 from the server 50 via a network (not shown).

For example, at the time of initial setting of the air conditioner 100A, the position information (region name of the installation place, etc.) of the air conditioner 100A is input by the user operating the remote controller 40, and this position information is stored in the storage unit 31a.

When acquiring the weather information from the server 50, the weather information acquisition unit 30 reads the position information of the air conditioner 100A from the storage unit 31a and transmits this position information to the server 50 via a network (not shown). The server 50 that has received the position information from the control unit 30 transmits the weather information near the air conditioner 100A to the control unit 30 via a network (not shown). This weather information includes outdoor temperature and outdoor humidity. The control unit 30 which receives the weather information from the server 50 stores the weather information in the storage unit 31a.

FIG. 14 is a flowchart of processing executed by the control unit 30 of the air conditioner according to the seventh embodiment (see FIG. 13 as needed).
Note that steps S101 to S104 in FIG. 14 are the same as those in the first embodiment (see FIG. 4), and therefore description thereof will be omitted.
In step S701, the control unit 30 causes the weather information acquisition unit 29 to acquire weather information including outdoor humidity from the server 50. Then, the control unit 30 stores this weather information in the storage unit 31a. The control unit 30 may perform the process of step S701 periodically, or may perform the process when using the weather information for air conditioning control.

Next, in step S101, the control unit 30 determines whether or not the indoor temperature T, which is the detection value of the indoor temperature sensor 27a, is equal to or higher than a first predetermined value T1. When the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes), the process of the control unit 30 proceeds to step S702.

In step S702, the control unit 30 determines whether the outdoor humidity U (relative humidity or absolute humidity of outdoor air) included in the weather information is equal to or less than a fourth predetermined value U4. The fourth predetermined value U4 is a threshold serving as a criterion for determining whether to freeze the indoor heat exchanger 15, and is set in advance. Further, the lower the outdoor humidity U, the lower the indoor humidity tends to be.

When the outdoor humidity U is equal to or less than the fourth predetermined value U4 in step S702 (S702: Yes), the process of the control unit 30 proceeds to step S102.
In step S102, the control unit 30 freezes the indoor heat exchanger 15. That is, with respect to the freezing time of the indoor heat exchanger 15 and the rotation speed of the compressor motor 11a, the control unit 30 executes the freezing process (S102) as in the case where the indoor temperature T is less than the first predetermined value T1.

As described above, since the outdoor humidity U is the fourth predetermined value or less, the indoor humidity is also likely to be low. That is, since the amount of water contained in the indoor air per unit volume is relatively small, there is almost no possibility that the indoor unit UAi will be exposed to dew during freezing of the indoor heat exchanger 15.
After freezing the indoor heat exchanger 15 in step S102, the control unit 30 sequentially performs thawing (S103) and drying (S104) of the indoor heat exchanger 15 and ends the series of processes (END).

On the other hand, when the outdoor humidity U is higher than the fourth predetermined value U4 in step S702 (S702: No), the control unit 30 ends the series of processes without performing the freezing process (S102) of the indoor heat exchanger 15. END. This is because when the outdoor humidity U is higher than the fourth predetermined value U4, the indoor humidity may also be high.

<Effect>
According to the seventh embodiment, even when the indoor temperature T is equal to or higher than the first predetermined value T1 (S101: Yes), when the outdoor humidity U is equal to or lower than the fourth predetermined value U4 (S702: Yes), the control unit 30. Freezes the indoor heat exchanger 15 (S102). As a result, the indoor heat exchanger 15 can be frozen and washed while suppressing the dew drop in the indoor unit UAi.
Further, according to the seventh embodiment, since it is not necessary to provide the outdoor unit Uo with a humidity sensor (not shown) for detecting the humidity of the outside air, cost reduction can be achieved.

≪Modification≫
As above, the air conditioner 100 and the like according to the present invention have been described in each embodiment, but the present invention is not limited to these descriptions, and various modifications can be made.
For example, instead of freezing and thawing the indoor heat exchanger 15, the control unit 30 may cause the indoor heat exchanger 15 to function as an evaporator and cause the indoor heat exchanger 15 to condense. For example, the control unit 30 controls the temperature of the indoor heat exchanger 15 to be equal to or lower than the dew point of the indoor air and higher than a predetermined freezing temperature (the temperature at which the indoor heat exchanger 15 starts freezing). The opening degree of the expansion valve 14 is adjusted. Thereby, the indoor heat exchanger 15 is condensed, and the indoor heat exchanger 15 is washed away by the condensed water.

Further, in the first embodiment, a case has been described in which it is determined whether or not the indoor temperature T during the process of step S101 (see FIG. 4) is equal to or higher than the first predetermined value T1, but the present invention is not limited to this. For example, the determination process of step S101 may be performed based on the indoor temperature T (average value or the like) for a predetermined time period prior to the determination process of step S101.

Even when the indoor temperature T (the detection value of the indoor temperature sensor 27a) is equal to or higher than the first predetermined value T1, in the cooling operation or the dehumidifying operation performed prior to the freezing process of the indoor heat exchanger 15, the indoor temperature T The control unit 30 may execute the freezing process when the decrease width or the decrease speed is equal to or greater than the fifth predetermined value. In this case, with respect to the freezing time of the indoor heat exchanger 15 and the rotation speed of the compressor motor 11a, the control unit 30 executes the freezing process as in the case where the indoor temperature T is less than the first predetermined value T1.
The "decrease width" of the room temperature T mentioned above is a decrease width of the room temperature T in a predetermined time within a period in which the cooling operation or the dehumidifying operation is continued. The same applies to the "falling rate" of the room temperature T.
For example, when the temperature difference between the room temperature T and the dew point is relatively large, the rate of latent heat in the amount of heat exchange between the refrigerant and air is small, so that the room air is easily cooled. As a result, the decrease width or decrease speed of the indoor temperature T often becomes equal to or higher than the fifth predetermined value. In such a case, there is a high possibility that the indoor air is not so humid, and therefore even if freeze cleaning is performed, there is almost no possibility that dew drops will occur in the indoor unit Ui.

In the sixth embodiment, when the room temperature T is equal to or higher than the first predetermined value T1 (S101: Yes in FIG. 12), the control unit 30 performs the cooling operation or the dehumidifying operation (S601) and then the freezing process (S601). Although the case of performing S102) has been described, the present invention is not limited to this. That is, regardless of the height of the indoor temperature T, the control unit 30 may perform the cooling operation or the dehumidifying operation prior to the freezing process (S102). As a result, the process of the control unit 30 can be simplified and the dew drop in the indoor unit Ui during the freezing process can be suppressed.

Further, in each embodiment, the case where the set temperature that can be changed by the remote controller 40 is 10° C. or higher and 32° C. or lower in both the cooling operation and the heating operation has been described, but the present invention is not limited thereto. For example, the range of set temperature that can be changed during the cooling operation and the range of set temperature that can be changed during the heating operation may be different. In this case, the control unit 30 executes the determination process of step S101 (see FIG. 4 and the like) based on the upper limit value of the set temperature during the cooling operation or the upper limit value of the set temperature during the heating operation.
In addition to the remote controller 40 described above, the air conditioning operation of the air conditioner 100 may be performed based on the operation of a mobile terminal (not shown) such as a mobile phone, a smartphone, or a tablet.

Also, the respective embodiments can be appropriately combined. For example, the second embodiment and the third embodiment may be combined. That is, when the indoor temperature T is equal to or higher than the first predetermined value T1, the control unit 30 shortens the freezing time of the indoor heat exchanger 15 (second embodiment), and further during freezing of the indoor heat exchanger 15. The rotation speed of the compressor motor 11a may be set low (third embodiment).

Further, in each embodiment, the configuration in which one indoor unit Ui (see FIG. 1) and one outdoor unit Uo (see FIG. 1) are provided has been described, but the configuration is not limited to this. That is, a plurality of indoor units connected in parallel may be provided, or a plurality of outdoor units connected in parallel may be provided.
In addition, the air conditioner 100 described in each embodiment is applicable to various types of air conditioners in addition to the wall-mounted air conditioner.

In addition, each embodiment is described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one including all the configurations described. Further, it is possible to add/delete/replace other configurations with respect to a part of the configurations of the respective embodiments.
In addition, the above-mentioned mechanisms and configurations are shown to be necessary for explanation, and not all the mechanisms and configurations are shown in the product.

100,100A Air conditioner 11 Compressor 11a Compressor motor (compressor motor)
12 Outdoor heat exchanger (condenser/evaporator)
13 outdoor fan 14 expansion valve 15 indoor heat exchanger (evaporator/condenser)
16 Indoor Fan 27a Indoor Temperature Sensor 27b Indoor Heat Exchanger Temperature Sensor 28 Outdoor Temperature Sensor 29 Meteorological Information Acquisition Section 30 Control Section 40 Remote Control 50 Server Q Refrigerant Circuit

Claims (10)

1. A refrigerant circuit in which a refrigerant circulates sequentially through a compressor, a condenser, an expansion valve, and an evaporator,
   A control unit for controlling at least the compressor and the expansion valve;
   An indoor temperature sensor that detects the temperature of the air-conditioned space,
   One of the condenser and the evaporator is an outdoor heat exchanger, the other is an indoor heat exchanger,
   The control unit causes the indoor heat exchanger to function as the evaporator, and performs a freezing process of freezing the indoor heat exchanger,
   When the detected value of the indoor temperature sensor is equal to or higher than the first predetermined value, the control unit does not perform the freezing process, or even when the freezing process is performed, the detected value of the indoor temperature sensor is the first predetermined value. The duration of the freezing process is shortened as compared with the case where it is less than a value, or the rotation of the motor of the compressor during the freezing process is more than that when the detected value of the indoor temperature sensor is less than the first predetermined value. Reduce the speed,
   An air conditioner in which the first predetermined value is lower than an upper limit value of a set temperature that can be changed by a remote controller during a cooling operation or a heating operation.
2. The air conditioner according to claim 1, wherein the control unit does not perform the freezing process when a detected value of the indoor temperature sensor is equal to or lower than a second predetermined value lower than the first predetermined value. Machine.
3. Even when the detected value of the indoor temperature sensor is equal to or higher than the first predetermined value, the control unit detects the detected value of the indoor temperature sensor when performing the cooling operation or the dehumidifying operation prior to the freezing process. The air conditioner according to claim 1, wherein the freezing process is performed in the same manner as when the value is less than the first predetermined value.
4. An indoor heat exchanger temperature sensor for detecting the temperature of the indoor heat exchanger,
   When the detected value of the indoor temperature sensor is equal to or higher than the first predetermined value, the control unit detects the detected value of the indoor heat exchanger temperature sensor when the cooling operation or the dehumidifying operation is performed prior to the freezing process. The air conditioner according to claim 3, wherein the freezing process is not performed when the difference in the detected value of the indoor temperature sensor with respect to is less than or equal to a third predetermined value.
5. The control unit sets the third predetermined value in response to the rotation speed of the motor of the compressor in the cooling operation or the dehumidifying operation performed prior to the freezing process,
   The air conditioner according to claim 4, wherein the third predetermined value increases as the rotation speed of the motor of the compressor increases.
6. The control unit performs a cooling operation or a blowing operation when the freezing process is not performed when the detected value of the indoor temperature sensor is equal to or higher than the first predetermined value. Air conditioner.
7. An indoor fan installed near the indoor heat exchanger,
   The air conditioner according to claim 1, wherein the control unit drives the indoor fan when the temperature of the air-conditioned space is detected using the indoor temperature sensor.
8. A weather information acquisition unit for acquiring weather information including outdoor humidity near the air conditioner from a server,
   Even if the detected value of the indoor temperature sensor is equal to or higher than the first predetermined value, the control unit controls the outdoor humidity included in the weather information acquired by the weather information acquisition unit to be equal to or lower than a fourth predetermined value. The air conditioner according to claim 1, wherein the freezing process is executed in the same manner as when the detected value of the indoor temperature sensor is less than the first predetermined value.
9. Even if the detected value of the indoor temperature sensor is equal to or higher than the first predetermined value, the control unit may decrease the detected value of the indoor temperature sensor in the cooling operation or the dehumidifying operation performed prior to the freezing process, or The air conditioning according to claim 3, wherein when the rate of decrease is equal to or higher than a fifth predetermined value, the freezing process is executed in the same manner as when the detected value of the indoor temperature sensor is lower than the first predetermined value. Machine.
10. A refrigerant circuit in which a refrigerant circulates sequentially through a compressor, a condenser, an expansion valve, and an evaporator,
    A control unit for controlling at least the compressor and the expansion valve;
    An indoor temperature sensor that detects the temperature of the air-conditioned space,
    One of the condenser and the evaporator is an outdoor heat exchanger, the other is an indoor heat exchanger,
    The control unit causes the indoor heat exchanger to function as the evaporator, and performs a freezing process of freezing the indoor heat exchanger,
    When the detected value of the indoor temperature sensor is equal to or higher than a first predetermined value, the control unit performs the freezing process after performing a cooling operation or a dehumidifying operation,
    An air conditioner in which the first predetermined value is lower than an upper limit value of a set temperature that can be changed by a remote controller during a cooling operation or a heating operation.

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