JP2022041710A - Air conditioner - Google Patents

Abstract

To avoid an increase in the influences of lower heat exchanging efficiency when performing frost formation processing for a long time.SOLUTION: An air conditioner includes a refrigerant circuit, and a control part, the refrigerant circuit including an indoor heat exchanger 13, the control part serving for cleaning operation to clean the indoor heat exchanger 13 when the cleaning of the indoor heat exchanger 13 is requested. The control part 40 performs frost formation processing and washing processing in the cleaning operation. The frost formation processing is to cause dew condensation on the surface of the indoor heat exchanger 13 and furthermore to form frost on the indoor heat exchanger 13. The washing processing is to cause dew condensation on the surface of the indoor heat exchanger 13 after the frost formation processing so that the surface of the indoor heat exchanger 13 is washed with dew condensation water.SELECTED DRAWING: Figure 5

Description

Regarding air conditioners.

Conventionally, a technical idea for cleaning an indoor heat exchanger by freezing and thawing the indoor heat exchanger after a heating operation is known (Patent Document 1 (Japanese Unexamined Patent Publication No. 2018-189262)).

Patent Document 1 discloses an example of an air conditioner that attaches frost (ice) to an indoor heat exchanger. However, the frost adhering to the indoor heat exchanger increases the ventilation resistance of the indoor heat exchanger, which may reduce the heat exchange efficiency of the indoor heat exchanger. In order to sufficiently clean the indoor heat exchanger, it is conceivable to carry out the frost formation treatment for a long time, but if the frost formation treatment is carried out for a long time, the influence of the decrease in the heat exchange efficiency becomes large.

The air conditioner of the first aspect includes a refrigerant circuit and a control unit. The refrigerant circuit includes an indoor heat exchanger. When the indoor heat exchanger is required to be cleaned, the control unit performs a cleaning operation, which is an operation of cleaning the indoor heat exchanger. The control unit performs a frost formation treatment and a water washing treatment in the washing operation. The frost formation treatment is a treatment for causing dew condensation on the surface of the indoor heat exchanger and further frosting the indoor heat exchanger. The water washing treatment is a treatment in which dew condensation is generated on the surface of the indoor heat exchanger after the frost formation treatment and the surface of the indoor heat exchanger is washed with the dew water.

The air conditioner according to the first aspect carries out a frost formation treatment and a water washing treatment in the washing operation. According to this configuration, in the washing operation, the indoor heat exchanger can be washed while shortening the time for performing the frost formation treatment. Therefore, it is possible to suppress a decrease in heat exchange efficiency of the indoor heat exchanger during the cleaning operation.

The air conditioner of the second aspect is the air conditioner of the first aspect, and in the frost formation treatment, the temperature of the refrigerant flowing through the indoor heat exchanger can be changed by the moisture contained in the indoor air in the indoor heat exchanger. Freeze the condensed water by lowering the temperature below the temperature. The water washing treatment causes dew condensation at a refrigerant temperature higher than the refrigerant temperature at the time of the frost formation treatment.

The air conditioner of the third aspect is the air conditioner of the first aspect or the second aspect, and the air conditioner further includes an expansion valve. The control unit adjusts the opening degree of the expansion valve to control the temperature of the refrigerant flowing through the indoor heat exchanger.

The air conditioner according to the fourth aspect is the air conditioner according to any one of the first aspect to the third aspect, and the target evaporation temperature at the time of frost formation treatment is lower than the target evaporation temperature at the time of water washing treatment.

The air conditioner according to the fifth aspect is the air conditioner according to any one of the first aspect to the fourth aspect, and the amount of dehumidification from the indoor air by the frost formation treatment is smaller than the amount of dehumidification from the indoor air by the water washing treatment. ..

According to this configuration, it is possible to more reliably suppress the decrease in heat exchange efficiency of the indoor heat exchanger during the frost formation treatment.

The air conditioner according to the sixth aspect is any of the air conditioners according to the first aspect to the fifth aspect, and the implementation time of the frost formation treatment is shorter than the implementation time of the water washing treatment.

According to this configuration, it is possible to more reliably suppress the decrease in heat exchange efficiency of the indoor heat exchanger during the frost formation treatment.

The air conditioner according to the seventh aspect is any of the air conditioners according to the first aspect to the sixth aspect, and further includes a compressor. The air conditioner continuously operates the compressor during the frosting treatment and the washing treatment.

According to this configuration, the operation time of the washing operation can be shortened.

The air conditioner according to the eighth aspect is the air conditioner according to any one of the first aspect to the sixth aspect, and a predetermined time is left between the frost formation treatment and the water washing treatment.

It is a block diagram of an air conditioner. It is a perspective view of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is a block diagram which shows the structure of a control part. It is sectional drawing of the air-conditioning indoor unit. It is a flowchart of a washing operation. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit. It is sectional drawing of the air-conditioning indoor unit.

<First Embodiment>
Hereinafter, the air conditioner 1 according to the present embodiment will be described with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that each figure is not necessarily exactly illustrated. For example, as shown in FIG. 1, the expansion valve 104 according to the present embodiment is connected to the outdoor circuit portion of the air conditioner outdoor unit 2 and exists at a position away from the air conditioner indoor unit 10. However, for convenience of explanation, the expansion valve 104 is shown in FIGS. 5, 7 to 14, which are the views of the air conditioning indoor unit 10. Further, in each figure, the area where the frost formation treatment is performed is indicated by horizontal line hatching, and the area where the water washing treatment is performed is indicated by vertical line hatching (see FIGS. 5, 7 to 14).

(1) Configuration of Air Conditioning Device 1 As shown in FIG. 1, the air conditioning device 1 according to the present embodiment includes an air conditioning outdoor unit 2 and an air conditioning indoor unit 10. The air conditioner 1 includes a refrigerant circuit 200 filled with a refrigerant. In the refrigerant circuit 200, the outdoor circuit portion housed in the air conditioning outdoor unit 2 and the indoor circuit section housed in the air conditioning indoor unit 10 are connected by the gas side connecting pipe 117a and the liquid side connecting pipe 117b. It is configured (see FIG. 1).

(2) Configuration of Air Conditioning Outdoor Unit 2 A compressor 101, a four-way switching valve 102, an outdoor heat exchanger 103, and an expansion valve 104 are connected to the outdoor circuit portion of the air conditioning outdoor unit 2 (see FIG. 1). ).

The compressor 101 is a device that sucks the low-pressure refrigerant in the refrigeration cycle from the suction pipe 111a, compresses the refrigerant by a compression mechanism (not shown), and discharges the compressed refrigerant to the discharge pipe 111b.

The type of the compressor 101 is not limited, but is, for example, a rotary type or scroll type positive displacement compressor. A compression mechanism (not shown) of the compressor 101 (not shown) is driven by a compressor motor (not shown). The refrigerant is compressed by driving the compression mechanism by the compressor motor. Here, the compressor motor is a motor capable of controlling the rotation speed by an inverter. The capacity of the compressor 101 is controlled by controlling the rotation speed of the compressor motor by the control unit 40 described later. The compression mechanism of the compressor 101 may be driven by a prime mover (for example, an internal combustion engine) other than the motor.

The four-way switching valve 102 is a switching valve for switching the direction of the flow of the refrigerant in the refrigerant circuit 200. As shown in FIG. 1, the discharge pipe 111b is connected to the first port P1 of the four-way switching valve 102. The suction pipe 111a is connected to the third port P3 of the four-way switching valve 102 with the accumulator 120 interposed therebetween. The accumulator 120 separates the liquid refrigerant and the gas refrigerant. The four-way switching valve 102 has a first state (state shown by a solid line in FIG. 1) in which the first port P1 and the fourth port P4 communicate with each other and the second port P2 and the third port P3 communicate with each other. It is possible to switch between the second state (the state shown by the dotted line in FIG. 1) in which the first port P1 and the second port P2 communicate with each other and the third port P3 and the fourth port P4 communicate with each other. ..

The outdoor heat exchanger 103 is a cross-fin type fin-and-tube heat exchanger. An outdoor fan 123 for sending outdoor air to the outdoor heat exchanger 103 is provided in the vicinity of the outdoor heat exchanger 103. One end side of the outdoor heat exchanger 103 is connected to the fourth port P4 of the four-way switching valve 102. The other end of the outdoor heat exchanger 103 is connected to the expansion valve 104. The second port P2 of the four-way switching valve 102 is connected to the indoor heat exchanger 13 via the gas side connecting pipe 117a.

The expansion valve 104 is a mechanism for adjusting the pressure and flow rate of the refrigerant flowing through the outdoor circuit portion. The expansion valve 104 is, for example, an electric expansion valve having a variable opening degree. However, the expansion valve 104 is not limited to the electric expansion valve, and a mechanism generally used as an expansion mechanism in the refrigeration cycle device may be appropriately selected. The control unit 40, which will be described later, controls the temperature of the refrigerant by adjusting the opening degree of the expansion valve 104.

(3) Configuration of Air Conditioning Indoor Unit 10 As shown in FIG. 1, an auxiliary heat exchanger 13a and a main heat exchanger 13b are connected to the indoor circuit portion. The auxiliary heat exchanger 13a and the main heat exchanger 13b are cross-fin type fin-and-tube heat exchangers having a plurality of heat transfer fins 21a and a plurality of heat transfer tubes 21b. Hereinafter, the auxiliary heat exchanger 13a and the main heat exchanger 13b may be collectively referred to as an indoor heat exchanger 13. An indoor fan 14 for sending indoor air to the indoor heat exchanger 13 is provided in the vicinity of the indoor heat exchanger 13.

(4) Detailed Configuration of Air Conditioning Indoor Unit 10 FIG. 2 is a perspective view of the air conditioning indoor unit 10 during operation. Further, FIG. 3 is a cross-sectional view of the air conditioning indoor unit 10. As shown in FIGS. 2 and 3, the air-conditioning indoor unit 10 includes a main body casing 11, an indoor heat exchanger 13, an indoor fan 14, a bottom frame 16, and a control unit 40. Further, as shown in FIG. 3, in the air-conditioning indoor unit 10, the auxiliary heat exchanger 13a is located on the windward side and the main heat exchanger 13b is located on the leeward side.

(4-1) Main body casing 11
The main body casing 11 has a top surface portion 11a, a front panel 11b, a back surface plate 11c, and a lower horizontal plate 11d. The main body casing 11 houses an indoor heat exchanger 13, an indoor fan 14, a bottom frame 16, a filter 24, and a control unit 40 inside.

The top surface portion 11a is located at the upper part of the main body casing 11, and a suction port 12 is provided at the front portion of the top surface portion 11a.

The front panel 11b constitutes the front portion of the air conditioning indoor unit 10 and has a curved shape without a suction opening.

(4-2) Filter 24
A filter 24 is arranged between the suction port 12 and the indoor heat exchanger 13. The filter 24 removes dust contained in the air sucked from the suction port 12.

(4-3) Indoor heat exchanger 13
In the present embodiment, the indoor heat exchanger 13 has an auxiliary heat exchanger 13a composed of one row of heat transfer tubes 21b and a main heat exchanger 13b composed of a plurality of rows of heat transfer tubes 21b. Refrigerant is flowing inside the indoor heat exchanger 13. The indoor heat exchanger 13 exchanges heat between the refrigerant flowing inside and the indoor air.

As described above, the indoor heat exchanger 13 (auxiliary heat exchanger 13a and main heat exchanger 13b) has a plurality of heat transfer fins 21a and a plurality of heat transfer tubes 21b, and is a cross fin type fin and -Tube type heat exchanger. The indoor air passes between the plurality of heat transfer fins 21a. Further, during heat exchange, air passes between the plurality of heat transfer fins 21a, and at the same time, the refrigerant flows through the plurality of heat transfer tubes 21b. The heat transfer tube 21b is folded a plurality of times and penetrates one heat transfer fin 21a a plurality of times.

(4-4) Indoor fan 14
The indoor fan 14 according to the present embodiment is a cross-flow fan. As shown in FIG. 3, the indoor fan 14 is located below the indoor heat exchanger 13. The indoor fan 14 sends the air taken in from the room to the indoor heat exchanger 13. The indoor air that has passed through the indoor heat exchanger 13 is blown into the room from the outlet 15. The indoor fan 14 and the indoor heat exchanger 13 are attached to the bottom frame 16.

(4-5) Wind direction adjusting blade 31
In the air conditioner 1 according to the present embodiment, the air outlet 15 is provided at the lower part of the main body casing 11. A wind direction adjusting blade 31 that changes the direction of the air blown from the air outlet 15 is rotatably attached to the air outlet 15. The wind direction adjusting blade 31 is driven by a motor (not shown). The wind direction adjusting blade 31 can not only change the blowing direction of air, but also open and close the air outlet 15. The wind direction adjusting blade 31 can take a plurality of postures having different inclination angles.

(4-6) Blow-out flow path 18
In the air conditioner 1 according to the present embodiment, the outlet flow path 18 is formed from the outlet 15 along the scroll 17 of the bottom frame 16. The outlet 15 is connected to the inside of the main body casing 11 by the outlet flow path 18.

The indoor air is sucked into the indoor fan 14 through the suction port 12 and the indoor heat exchanger 13 by the operation of the indoor fan 14, and is blown out from the indoor fan 14 through the outlet flow path 18 and from the outlet 15.

(4-7) Control unit 40
The control unit 40 is located on the right side of the indoor heat exchanger 13 and the indoor fan 14 when the main body casing 11 is viewed from the front panel 11b.

The control unit 40 is realized by a computer. The control unit 40 includes a control arithmetic unit and a storage device. FIG. 4 shows a block diagram showing a schematic configuration of the control unit 40. The control unit 40 has a cooling operation control unit 42, a heating operation control unit 43, and a cleaning operation control unit 46 as functional units. Under the control of the control unit 40, the air conditioner 1 can perform a cooling operation, a heating operation, and a cleaning operation.

A processor such as a CPU or GPU can be used as the control arithmetic unit of the control unit 40. The control arithmetic unit reads a program stored in the storage device and performs a predetermined arithmetic processing according to this program. Further, the control arithmetic unit can write the arithmetic result to the storage device and read the information stored in the storage device according to the program. The storage device can be used as a database.

The control unit 40 shown in this embodiment is only an example. The air conditioner 1 may realize the same function as the function exhibited by the control unit 40 according to the present embodiment by hardware such as a logic circuit, or may be realized by a combination of hardware and software. good.

Further, the control unit 40 may not have a part or all of the functions described in the present embodiment. For example, a part or all of the functions of the control unit 40 described in the present embodiment may be realized by a server or the like installed at a place different from the air conditioner 1.

In the cleaning operation, the control unit 40 according to the present embodiment causes dew condensation on the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b, and further frosts the auxiliary heat exchanger 13a and the main heat exchanger 13b. Carry out the process. Further, the control unit 40 according to the present embodiment causes dew condensation on the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b after the frost formation treatment, and the dew water causes the auxiliary heat exchanger 13a and the main heat exchanger 13b to form dew. Carry out a water wash to wash the surface. Details will be described later.

(4-8) Various Sensors Various sensors such as the first thermistor 105, the third thermistor 107, the fourth thermistor 108, and the fifth thermistor 109 are appropriately attached to the air conditioner 1. The control unit 40 includes the room temperature, the ambient outside temperature, the temperature and pressure of the refrigerant sucked into the compressor 101, the temperature and pressure of the refrigerant discharged from the compressor 101, and the indoor heat exchanger detected by these sensors. It receives at least one of the temperature of the refrigerant in 13 and the temperature of the refrigerant in the outdoor heat exchanger 103. The control unit 40 controls the operation of each unit of the air conditioner 1 such as the indoor fan 14, the compressor 101, the four-way switching valve 102, and the expansion valve 104 based on the detected values of various sensors.

In the present embodiment, the control unit 40 receives the temperature of the refrigerant detected by the first thermistor 105, the third thermistor 107, the fourth thermistor 108, and the fifth thermistor 109, so that the temperature of the refrigerant flowing through the indoor heat exchanger 13 is reached. Can be confirmed. In this embodiment, the first thermistor 105 is attached to the pipe between the expansion valve 104 and the auxiliary heat exchanger 13a. Further, the third thermistor 107 is attached to a pipe between the auxiliary heat exchanger 13a and the main heat exchanger 13b. Further, the fourth thermistor 108 is attached to the main heat exchanger 13b. Further, the fifth thermistor 109 is attached between the main heat exchanger 13b and the compressor 101 (see FIGS. 1 and 5). However, the method for confirming the temperature of the refrigerant flowing through the indoor heat exchanger 13 is not limited to this, and can be appropriately changed.

(5) Operation of the air conditioner 1 The operation of various devices of the air conditioner 1 when the air conditioner 1 executes the cooling operation, the heating operation, and the cleaning operation will be described below.

In the air conditioner 1, the four-way switching valve 102 can switch the flow of the refrigerant to either the first cycle or the second cycle.

(5-1) Cooling operation In the cooling operation, the flow of the refrigerant is the first cycle. In the first cycle, the four-way switching valve 102 is set to the first state (the state shown by the solid line in FIG. 1). When the compressor 101 is operated in the first state, the steam compression refrigeration cycle in which the outdoor heat exchanger 103 becomes a refrigerant condenser and the auxiliary heat exchanger 13a and the main heat exchanger 13b serve as a refrigerant evaporator is performed in the refrigerant circuit 200. Will be done.

The high-pressure refrigerant discharged from the compressor 101 exchanges heat with the outdoor air in the outdoor heat exchanger 103 and condenses. The refrigerant that has passed through the outdoor heat exchanger 103 is depressurized as it passes through the expansion valve 104. The refrigerant decompressed by the expansion valve 104 exchanges heat with the room air in the auxiliary heat exchanger 13a and the main heat exchanger 13b and evaporates. The refrigerant that has passed through the auxiliary heat exchanger 13a and the main heat exchanger 13b is sucked into the compressor 101 and compressed.

(5-2) Heating operation In the heating operation, the flow of the refrigerant is the second cycle. In the second cycle, the four-way switching valve 102 is set to the second state (the state shown by the dotted line in FIG. 1). When the compressor 101 is operated in the second state, the steam compression refrigeration cycle in which the outdoor heat exchanger 103 becomes the refrigerant evaporator and the auxiliary heat exchanger 13a and the main heat exchanger 13b serve as the refrigerant condenser is in the refrigerant circuit 200. Will be done.

The high-pressure refrigerant discharged from the compressor 101 exchanges heat with the room air in the auxiliary heat exchanger 13a and the main heat exchanger 13b and condenses. The condensed refrigerant is decompressed when passing through the expansion valve 104, and then heat exchanges with the outdoor air in the outdoor heat exchanger 103 to evaporate. The refrigerant that has passed through the outdoor heat exchanger 103 is sucked into the compressor 101 and compressed.

(5-3) Cleaning operation The air conditioner 1 according to the present embodiment can execute a cleaning operation. The operation of the air conditioner 1 during the cleaning operation is controlled by the cleaning operation control unit 46. In the washing operation, a water washing treatment and a frost formation treatment are carried out.

(5-3-1) Frost formation treatment The frost formation treatment is a treatment for causing dew condensation on the surface of the indoor heat exchanger 13 and further frosting the indoor heat exchanger 13. The operation of each part of the air conditioner 1 during the frosting process is controlled by the frosting process control unit 47.

The frost formation treatment freezes the dew condensation water by lowering the temperature of the refrigerant flowing through the indoor heat exchanger 13 to a temperature at which the moisture contained in the indoor air can be frozen by the indoor heat exchanger 13.

Hereinafter, for convenience of explanation, "the temperature at which the moisture contained in the indoor air can be frozen in the indoor heat exchanger 13" is referred to as "freezing temperature".

The flow of the refrigerant during the frost formation treatment is the first cycle, similarly to the flow of the refrigerant during the cooling operation. Therefore, during the frost formation operation, the four-way switching valve 102 is set to the first state (solid line in FIG. 1). When the compressor 101 is operated in the first state, in the refrigerant circuit 200, the outdoor heat exchanger 103 becomes a refrigerant condenser, and the auxiliary heat exchanger 13a and the main heat exchanger 13b serve as a refrigerant evaporator. Will be done.

In the air conditioner 1 according to the present embodiment, the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a and the main heat exchanger 13b is set to be equal to or lower than the freezing temperature, so that the surface of the auxiliary heat exchanger 13a and the main heat exchanger 13b is exposed. The first frosting treatment, which is a treatment for frosting the generated dew condensation water, is performed.

The frost formation control unit 47 determines the frequency of the compressor 101 so that the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a and the main heat exchanger 13b becomes equal to or lower than the freezing temperature when the first frost formation treatment is performed. And controls the opening degree of the expansion valve 104.

(5-3-2) Water washing treatment The water washing treatment is a treatment performed after the frost formation treatment, in which dew condensation is caused on the surface of the indoor heat exchanger 13 and the surface of the indoor heat exchanger 13 is covered with the dew water. It is a washing process. The operation of each part of the air conditioner 1 during the water washing treatment is controlled by the water washing treatment control unit 48.

The water washing treatment causes dew condensation at a refrigerant temperature higher than the refrigerant temperature at the time of the frost formation treatment. In other words, the water washing treatment is a treatment that causes dew condensation by raising the temperature of the refrigerant flowing through the indoor heat exchanger 13 to be higher than the freezing temperature. Preferably, the refrigerant temperature during the water washing treatment is controlled by the water washing treatment control unit 48 so as to be higher than the freezing temperature and lower than the dew point temperature of the indoor air.

The flow of the refrigerant during the washing process is the first cycle, similar to the flow of the refrigerant during the cooling operation. Therefore, at the time of washing with water, the four-way switching valve 102 is set to the first state (solid line in FIG. 1). When the compressor 101 is operated in the first state, in the refrigerant circuit 200, the outdoor heat exchanger 103 becomes a refrigerant condenser, and the auxiliary heat exchanger 13a and the main heat exchanger 13b serve as a refrigerant evaporator. Will be done.

In the air conditioner 1 according to the present embodiment, the first water washing treatment, which is a treatment for condensing the moisture contained in the indoor air on the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b, is performed.

When the first water washing treatment is performed, the water washing treatment control unit 48 determines the frequency of the compressor 101 so that the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a and the main heat exchanger 13b becomes higher than the freezing temperature. It controls the opening degree of the expansion valve 104 and the rotation speed of the indoor fan 14.

Specifically, the water washing treatment control unit 48 has a frequency of the compressor 101 so that the temperature detected from the first thermistor 105 becomes a temperature higher than the freezing temperature when the first water washing treatment is performed. It controls the opening degree of the expansion valve 104, the rotation speed of the indoor fan 14, and the rotation speed of the outdoor fan 123.

For example, when the temperature of the refrigerant detected from the first thermistor 105 is equal to or lower than the freezing temperature, the control unit 40 increases the rotation speed of the indoor fan 14, decreases the rotation speed of the outdoor fan 123, and causes the compressor 101. At least one of lowering the frequency and lowering the amount of decompression by the expansion valve 104 is performed.

Further, when the temperature of the refrigerant detected from the fourth thermistor 108 is higher than the temperature of the refrigerant detected from the first thermistor 105, the control unit 40 reduces the rotation speed of the indoor fan 14 and the frequency of the compressor 101. And at least one of them. In this way, the water washing treatment control unit 48 controls the indoor fan 14 and the compressor 101 so that dew condensation occurs in the entire area of the indoor heat exchanger 13.

(5-3-3) Details of control during washing operation In the present embodiment, the target evaporation temperature of the frost formation control unit 47 and the water washing treatment control unit 48 is the target evaporation temperature during the water washing treatment. Each part of the air conditioner 1 is controlled so as to be lower than the above. In this embodiment, the target evaporation temperature during the frost formation treatment and the washing treatment can be detected by using any one of the first thermistor 105, the third thermistor 107, and the fourth thermistor 108 according to the application. Is.

Further, in the present embodiment, the frosting treatment control unit 47 and the water washing treatment control unit 48 are air-conditioned so that the amount of dehumidification from the indoor air by the frosting treatment is smaller than the amount of dehumidification from the indoor air by the water washing treatment. It controls each part of the device 1. The amount of water removed by the frost formation treatment is preferably less than half the amount of water removed by the washing treatment. In the present embodiment, the amount of dehumidification by the frost formation treatment and the washing treatment can be estimated from the humidity detected by the humidity sensor (not shown), the indoor heat exchange temperature, the air volume, and the like. However, the method for estimating the amount of dehumidification by the frost formation treatment and the washing treatment is not limited to this, and may be appropriately selected.

Further, in the present embodiment, the frost formation control unit 47 and the water washing treatment control unit 48 control each part of the air conditioner 1 so that the execution time of the frost formation treatment is shorter than the execution time of the water washing treatment. The implementation time of the frost formation treatment is preferably shorter than half of the implementation time of the water washing treatment. In the present embodiment, the execution time of the frost formation treatment and the washing treatment can be detected by a timer, respectively.

Hereinafter, the first washing operation, which is the washing operation in which the first frost formation treatment and the first water washing treatment are carried out, will be described. Although the details will be described later, the washing operation includes the first washing operation to the ninth washing operation.

(5-3-4) Operation during cleaning operation Hereinafter, the operation of each part of the air conditioner 1 during the first cleaning operation will be described with reference to the flowchart shown in FIG. The flowchart shown in FIG. 6 is merely an example, and may be appropriately changed as long as there is no contradiction. For example, other steps (not shown) may be included before and after each step, and the order of each step may be appropriately changed within a range that does not contradict each other.

In step S1 of FIG. 6, the cleaning operation control unit 46 determines whether or not there is a cleaning operation command from the remote controller or the like, proceeds to step S2 if there is a cleaning operation command, and waits if there is no cleaning operation command. Then, the determination of whether or not there is a cleaning operation command is continued.

The cleaning operation control unit 46 executes the first frost formation process in step S2. As described above, the operation of each part of the air conditioner 1 during the frosting process is controlled by the frosting process control unit 47. For example, the frost formation control unit 47 sets the target evaporation temperature of the auxiliary heat exchanger 13a and the main heat exchanger 13b to −5 to −10 ° C., stops the operation of the indoor fan 14, or operates the indoor fan 14 at a low speed, and expands the valve 104. The first frost formation treatment is carried out by reducing the opening degree of the compressor 101 and controlling the frequency of the compressor 101 to 15 to 25 Hz. However, these controls are examples and can be changed as appropriate.

In step S3, the cleaning operation control unit 46 confirms whether or not the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a and the main heat exchanger 13b is equal to or lower than the freezing temperature. In the present embodiment, the cleaning operation control unit 46 receives the temperature of the refrigerant detected by any of the first thermistor 105, the third thermistor 107, and the fourth thermistor 108, thereby receiving the auxiliary heat exchanger 13a and the main heat exchanger. The temperature of the refrigerant flowing through 13b can be confirmed.

In step S4, the cleaning operation control unit 46 confirms whether or not a predetermined time has elapsed since the start of the first frost formation treatment. In the present embodiment, the cleaning operation control unit 46 can confirm whether or not the predetermined time has elapsed by operating the timer at the start of step S2. Here, the predetermined time is, for example, 15 minutes. However, the predetermined time in step S4 is not limited to this as long as the execution time of the first frost formation treatment is shorter than the implementation time of the first water washing treatment. Therefore, the predetermined time in step S4 may be longer or shorter than 15 minutes.

In this embodiment, the implementation time of the first frost formation treatment refers to the time from the start of step S2 to the end of step S5.

If the predetermined time has elapsed in step S4, the cleaning operation control unit 46 proceeds to step S5, and if the predetermined time has not elapsed, the cleaning operation control unit 46 continues step S4.

The cleaning operation control unit 46 ends the first frost formation process in step S5. The control unit 40 proceeds to step S6 as soon as the first frost formation treatment is completed, and starts the first water washing treatment.

The washing operation control unit 46 executes the first washing process in step S6. As described above, the operation of each part of the air conditioner 1 during the water washing process is controlled by the water washing process control unit 48. For example, the water washing treatment control unit 48 sets the target evaporation temperature to 5 ° C., drives the indoor fan 14, opens the opening degree of the expansion valve 104 more than during the first frost treatment, and controls the frequency of the compressor 101 to 60 Hz. Therefore, the first washing treatment is carried out. However, these controls are examples and can be changed as appropriate.

In the present embodiment, the washing operation control unit 46 does not leave a predetermined time between the frost formation treatment and the water washing treatment. In other words, the process of step S6 is started immediately after the process of step S5 is performed. An embodiment in which the washing operation control unit 46 allows a predetermined time between the frost formation treatment and the water washing treatment will be described later.

Further, in the present embodiment, the operation of the compressor 101 continues during the frost formation treatment and the water washing treatment. In other words, in the present embodiment, the switching between the frost formation treatment and the water washing treatment is performed by adjusting the frequency of the compressor 101, the opening degree of the expansion valve 104, and the rotation speed of the indoor fan 14.

In step S7, the cleaning operation control unit 46 confirms whether or not the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a and the main heat exchanger 13b is higher than the temperature of the refrigerant during the frost formation treatment.

When the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a and the main heat exchanger 13b is higher than the temperature of the refrigerant at the time of frost formation (Yes in step S7), the cleaning operation control unit 46 is in step S8. Proceed to. In other cases, the cleaning operation control unit 46 continues the process of step S6 (when No in step S7).

In step S8, the washing operation control unit 46 determines whether or not a predetermined time has elapsed since the start of the first frost formation treatment. In the present embodiment, the cleaning operation control unit 46 can confirm whether or not the predetermined time has elapsed by operating the timer at the start of step S6. Here, the predetermined time is, for example, 90 minutes. However, the predetermined time in step S8 is not limited to this as long as the execution time of the first frost formation treatment is shorter than the implementation time of the first water washing treatment. Therefore, the predetermined time in step S8 may be longer or shorter than 90 minutes.

In this embodiment, the implementation time of the first water washing treatment refers to the time from the start of step S6 to the end of step S9.

If the predetermined time has elapsed in step S8, the cleaning operation control unit 46 proceeds to step S9, and if the predetermined time has not elapsed, the cleaning operation control unit 46 continues step S8.

The washing operation control unit 46 ends the first washing process in step S9.

The cleaning operation control unit 46 ends the first cleaning operation in step S10.

As described above, in the first washing operation according to the present embodiment, the auxiliary heat exchanger 13a and the main heat exchanger 13b are washed by performing the first water washing treatment after the first frost formation treatment.

Even during the operation of the first cleaning operation, the cleaning operation control unit 46 stops the first cleaning operation when there is a command to stop the cleaning operation from the remote controller or the like.

Further, the washing operation control unit 46 performs a drying process of drying the auxiliary heat exchanger 13a and the main heat exchanger 13b after performing the process of step S9 in the above flowchart (after the completion of the first water washing process). There may be. The drying treatment may be performed, for example, by continuously blowing air from the indoor fan 14 for a predetermined time to dry the auxiliary heat exchanger 13a and the main heat exchanger 13b.

(6) Features Conventionally, as shown in Patent Document 1, the technical idea of cleaning the indoor heat exchanger by performing frost formation treatment on the indoor heat exchanger and thawing the frost adhering by the frost formation treatment has been developed. It has been disclosed.

However, when the indoor heat exchanger is cleaned by performing the frost formation treatment, the ventilation resistance of the indoor heat exchanger increases due to the frost adhering to the indoor heat exchanger. This reduces the heat exchange efficiency of the indoor heat exchanger. In particular, in order to sufficiently clean the indoor heat exchanger, it is conceivable to perform frost formation treatment for a long time, but when the indoor heat exchanger is washed for a long time, the effect of a decrease in heat exchange efficiency is large. It is possible that it will be.

More specifically, if the ventilation resistance of the indoor heat exchanger increases due to the frost adhering to the indoor heat exchanger and the heat exchange efficiency of the indoor heat exchanger decreases, dew condensation may not proceed. Therefore, even if the frost formation operation is performed for a long time, it may be difficult to secure a sufficient amount of dew condensation to wash away the dirt adhering to the indoor heat exchanger.

Further, Patent Document 1 discloses an example of an air conditioner that drives an indoor fan when performing a frost formation treatment.

However, when the frost formation treatment is performed for a long time, a large amount of frost adheres to the indoor heat exchanger. Therefore, by driving the indoor fan during the frost formation process, a part of the frost may be peeled off from the indoor heat exchanger by the wind of the indoor fan and blown out to the air-conditioned space through the air outlet. When frost is blown out into the air-conditioned space, it not only causes discomfort to the user, but may also promote corrosion of the floor, walls, etc. in the air-conditioned space.

Further, by performing the frost formation treatment, the inside of the main body casing of the air conditioner indoor unit may be filled with cold air, and the temperature in the vicinity of the air outlet of the air conditioner indoor unit may decrease. In particular, when the frost formation treatment is performed for a long time, dew condensation may occur in the vicinity of the air outlet, and the dew water may drip from the air outlet to the floor or the like of the air-conditioned space.

On the other hand, when the frost formation treatment time is shortened, it is conceivable that a sufficient amount of dew condensation is not secured and frost does not sufficiently adhere to the indoor heat exchanger. If the amount of frost adhering to the indoor heat exchanger is small, the amount of frost that is thawed is small, so that the indoor heat exchanger may not be properly cleaned.

(6-1)
The air conditioner 1 according to the present embodiment includes a refrigerant circuit 200 and a control unit 40. The refrigerant circuit 200 includes an indoor heat exchanger 13. The control unit 40 performs a cleaning operation, which is an operation of cleaning the indoor heat exchanger 13, when cleaning of the indoor heat exchanger 13 is required. The control unit 40 performs a frost formation treatment and a water washing treatment in the washing operation. The frost formation treatment is a treatment for causing dew condensation on the surface of the indoor heat exchanger 13 and further frosting the indoor heat exchanger 13. The water washing treatment is a treatment in which dew condensation is generated on the surface of the indoor heat exchanger 13 after the frost formation treatment and the surface of the indoor heat exchanger 13 is washed with the dew condensation water. In the present embodiment, the indoor heat exchanger 13 has an auxiliary heat exchanger 13a and a main heat exchanger 13b.

In the air conditioner 1 according to the present embodiment, the washing operation is performed by the frost formation treatment and the water washing treatment. According to this configuration, in the washing operation, the indoor heat exchanger can be washed while shortening the time for performing the frost formation treatment. Therefore, it is possible to suppress the amount of frost adhering to the indoor heat exchanger 13 during the cleaning operation. Therefore, it is possible to suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 during the cleaning operation.

Further, during the washing operation, the amount of frost adhering to the indoor heat exchanger 13 is suppressed, so that the frost is suppressed from being blown out from the outlet 15. Therefore, the comfort of the user can be maintained, and the corrosion of the floor, walls, etc. in the air-conditioned space can be suppressed.

Further, by shortening the frost formation treatment time during the washing operation, it is possible to suppress the formation of dew condensation in the vicinity of the outlet 15. Therefore, it is possible to prevent the dew condensation water from dripping from the outlet 15 onto the floor or the like of the air-conditioned space.

Further, in the air conditioner 1 according to the present embodiment, the washing operation is performed by the frost formation treatment and the water washing treatment performed after the frost formation treatment. Therefore, even if oil stains or the like adhere to the indoor heat exchanger 13, the indoor heat exchanger 13 can be suitably cleaned.

(6-2)
In the air conditioner 1 according to the present embodiment, the frost formation treatment is performed by setting the temperature of the refrigerant flowing through the indoor heat exchanger 13 to be equal to or lower than the temperature at which the moisture contained in the indoor air can be frozen in the indoor heat exchanger 13. Freeze the water. The water washing treatment causes dew condensation at a refrigerant temperature higher than the refrigerant temperature at the time of the frost formation treatment.

(6-3)
The air conditioner 1 according to the present embodiment further includes an expansion valve 104. The control unit 40 controls the opening degree of the expansion valve 104 to control the temperature of the refrigerant flowing through the indoor heat exchanger 13.

(6-4)
In the air conditioner 1 according to the present embodiment, the target evaporation temperature during the frost formation treatment is lower than the target evaporation temperature during the water washing treatment.

(6-5)
In the air conditioner 1 according to the present embodiment, the amount of dehumidification from the indoor air by the frost formation treatment is smaller than the amount of dehumidification from the indoor air by the water washing treatment.

According to this configuration, it is possible to more reliably suppress the decrease in heat exchange efficiency of the indoor heat exchanger 13 during the frost formation treatment.

(6-6)
In the air conditioner 1 according to the present embodiment, the implementation time of the frost formation treatment is shorter than the implementation time of the water washing treatment.

According to this configuration, it is possible to more reliably suppress the decrease in heat exchange efficiency of the indoor heat exchanger 13 during the frost formation treatment.

(6-7)
The air conditioner 1 according to the present embodiment further includes a compressor 101. The compressor 101 is continuously operated during the frost formation treatment and the water washing treatment.

The air conditioner 1 according to the present embodiment continuously operates the compressor 101 during the frost formation treatment and the water washing treatment. In other words, the switching between the frost formation treatment and the water washing treatment is performed by adjusting the frequency of the compressor 101 and the opening degree of the expansion valve 104.

In the air conditioner 1 according to the present embodiment, the time for the cleaning operation can be shortened.

(7) Modification example The above embodiment can be appropriately modified as shown in the following modification example. Each modification may be applied in combination with the modification according to the present embodiment or the modification according to another embodiment as long as there is no contradiction. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

(7-1) Modification 1A
In the above embodiment, the air conditioner 1 in which a predetermined time is not left between the first frost formation treatment and the first water washing treatment has been described. However, the example of the air conditioner according to the present disclosure is not limited to this, and the air conditioner may have a predetermined time between the first frost formation treatment and the first water washing treatment, for example. good. The predetermined time between the first frost formation treatment and the first water washing treatment is shorter than the implementation time of the frost formation treatment (time from step S2 to step S5 in FIG. 6), for example, 5 minutes. Further, it is preferable to drive the indoor fan 14 for a predetermined time between the first frost formation treatment and the first water washing treatment.

In the air conditioner according to this modification, the frost adhering to the indoor heat exchanger 13 is naturally thawed by allowing a predetermined time between the frost formation treatment and the water washing treatment. When the frost adhering to the indoor heat exchanger 13 is naturally thawed, the frost dehumidifies the frost, and dew condensation water is generated in the indoor heat exchanger 13. The indoor heat exchanger 13 is washed with the dew condensation water. Therefore, in this modification, it is possible to shorten the execution time of the washing treatment (the time from step S6 to step S9 in FIG. 6).

In the air conditioner according to this modification, the time required for washing with water is shortened. Therefore, in the air conditioner according to this modification, energy saving of the cleaning operation is realized.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-2) Modification 1B
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by carrying out the first frost formation treatment and the first water washing treatment has been described. However, the example of the washing operation according to the present disclosure is not limited to this, and for example, in the water washing treatment, the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a is made higher than the temperature of the refrigerant at the time of the first defrosting treatment. This may be a second washing treatment that causes dew condensation. It is preferable that the refrigerant temperature at the time of the second washing treatment is controlled to be higher than the freezing temperature and lower than the dew point temperature of the indoor air.

The washing operation according to this modification is carried out by the first frost formation treatment and the second water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a second cleaning operation.

In the second washing operation, after frost is formed on the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by the first frosting treatment, the surface of the auxiliary heat exchanger 13a is washed with dew condensation water by the second washing treatment. (See FIG. 7). As described above, the area where the frost formation treatment is performed is shown by horizontal line hatching, and the area where the water washing treatment is performed is shown by vertical line hatching.

In the second cleaning operation, the cleaning operation control unit 46 detects the refrigerant temperature detected by the fourth thermistor 108 from the first thermistor 105 or the third thermistor 107 because the refrigerant temperature is higher than the refrigerant temperature detected by the third thermistor 107. The opening degree of the expansion valve 104, the frequency of the compressor 101, the air volume of the indoor fan 14, and the air volume of the outdoor fan 123 are controlled so that the refrigerant temperature is higher than the freezing temperature.

For example, when the refrigerant temperature detected from the third thermistor 107 is lower than the freezing temperature, the control unit 40 increases the rotation speed of the indoor fan 14, decreases the frequency of the compressor 101, and reduces the pressure by the expansion valve. At least one of lowering and lowering the rotation speed of the outdoor fan is carried out.

When the refrigerant temperature detected by the third thermistor 107 is higher than the temperature detected by the first thermistor 105, the cleaning operation control unit 46 causes the rotation speed of the indoor fan 14 to decrease and the frequency of the compressor 101 to decrease. At least one of the following is carried out, that is, the amount of depressurization by the expansion valve is decreased, and the rotation speed of the outdoor fan is increased.

Alternatively, when the refrigerant temperature detected by any of the first thermistor 105, the third thermistor 107, and the fourth thermistor 108 is equal to or lower than the freezing temperature, the cleaning operation control unit 46 increases the air volume of the indoor fan 14. At least one of lowering the frequency of the compressor 101, lowering the amount of depressurization by the expansion valve, and lowering the rotation speed of the outdoor fan is carried out.

During the second water washing process in the second washing operation, the temperature of the refrigerant flowing in the region of the indoor heat exchanger 13 excluding the auxiliary heat exchanger 13a (here, most of the main heat exchanger 13b) is the temperature of the indoor heat exchanger. It is preferable that the temperature is controlled to be higher than the dew point temperature of the air. Although not limited, in the second water washing process of the second washing operation, the auxiliary heat exchanger 13a is controlled as an evaporation region and most of the main heat exchanger 13b is controlled as an overheating region by the cleaning operation control unit 46. .. As a result, dew condensation water is mainly generated in the auxiliary heat exchanger 13a.

Further, in this modification, it has been described that the second water washing treatment is an operation in which the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a is set to be lower than the dew point temperature of the indoor air and higher than the freezing point to generate dew condensation water. However, it is not limited to this. In the second water washing treatment, for example, the temperature of the refrigerant flowing in the leeward region of the indoor heat exchanger 13 such as the main heat exchanger 13b is made higher than the refrigerant temperature at the time of the first frost formation treatment, so that the dew condensation water is formed. It may be an operation that causes the above. However, in general, since the indoor heat exchanger tends to concentrate the dirt on the wind upper region, the second water washing treatment is performed on the wind upper region of the indoor heat exchanger 13 (here, the auxiliary heat exchanger 13a). ) Is made higher than the temperature of the refrigerant at the time of the first frost treatment to generate dew condensation water.

The air conditioner according to the present modification can suitably clean the indoor heat exchanger 13 even when the atmosphere in the air-conditioned space is dry.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-3) Modification 1C
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the washing operation according to the present disclosure is not limited to this, and for example, in the water washing treatment, the temperature of the refrigerant flowing in a part of the auxiliary heat exchanger 13a is set to the temperature of the refrigerant at the time of the first frost formation treatment. It may be carried out by a third washing treatment, which is an operation of generating dew condensation water by raising the temperature above the temperature.

The washing operation according to this modification is carried out by the first frost formation treatment and the third water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a third cleaning operation.

In the third washing operation, after frost is formed on the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by the first frosting treatment, the surface of a part of the region in the auxiliary heat exchanger 13a is subjected to the third washing treatment. Is washed with dew water (see FIG. 8).

During the third water washing process in the third washing operation, the temperature of the refrigerant flowing in the region of the indoor heat exchanger 13 excluding a part of the auxiliary heat exchanger 13a is controlled to be higher than the dew point temperature of the indoor air. It is preferable to be done. Although not limited, in the third water washing process in the third washing operation, a part of the auxiliary heat exchanger 13a is controlled as an evaporation region and the other region is controlled as a superheat region by the cleaning operation control unit 46. .. As a result, dew condensation water is mainly generated in a part of the region of the auxiliary heat exchanger 13a.

Further, in this modification, the third water washing treatment causes the temperature of the refrigerant flowing in a part of the auxiliary heat exchanger 13a to be higher than the temperature of the refrigerant during the first frost formation treatment to generate dew condensation water. I explained that it is driving, but it is not limited to this. In the third water washing treatment, for example, the temperature of the refrigerant flowing in the leeward region of the indoor heat exchanger 13 such as a part of the region in the main heat exchanger 13b is set higher than the refrigerant temperature at the time of the first frost formation treatment. It may be an operation that causes dew condensation water by doing so. However, in consideration of maintaining the aesthetic appearance of the air conditioner by giving priority to cleaning the area where dirt is conspicuous from the user of the air conditioner, the third water washing process is an area that is easily accessible to the user. (In this embodiment, the temperature of the refrigerant flowing in a part of the region of the auxiliary heat exchanger 13a and near the front panel 11b of the air conditioner) is higher than the temperature of the refrigerant at the time of the first frost formation treatment. It is preferable that the operation is such that dew condensation water is generated.

In the air conditioner according to the present modification, the indoor heat exchanger 13 can be suitably cleaned even when the atmosphere in the air-conditioned space is dry.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-4) Modification 1D
Although the description is omitted in the above embodiment, the air conditioner may further include a humidifying unit (not shown). In this case, the air-conditioning indoor unit may have an outlet of the humidifying unit inside the main body casing 11. Alternatively, a humidifying unit may be further installed in the air-conditioned space in which the air-conditioned indoor unit is installed, and the air-conditioned indoor unit may be controlled to perform a cleaning operation in conjunction with the humidifying unit.

The air conditioner according to this modification can suitably clean the indoor heat exchanger 13 by using the moisture obtained from the humidifying unit even when the atmosphere in the air-conditioned space is dry. can.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-5) Modification 1E
Although the description is omitted in the above embodiment, the control unit 40 determines the frequency of the compressor 101 and the expansion valve 104 so that the temperature of the surface of the indoor heat exchanger 13 becomes lower than the freezing temperature in the first frost formation treatment. It is preferable to control the opening degree. The temperature of the surface of the indoor heat exchanger 13 can be detected, for example, by attaching the second thermistor 106 to the indoor heat exchanger 13. However, the method for detecting the surface temperature of the indoor heat exchanger 13 is not limited to this, and can be appropriately changed.

The air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-6) Modification 1F
In the above embodiment, the air conditioner in which the target evaporation temperature during the frost formation treatment is lower than the target evaporation temperature during the water washing treatment has been described. However, the example of the air conditioner according to the present disclosure is not limited to this, and the air conditioner may be, for example, one in which the target evaporation temperature at the time of washing with water is not set.

In the air conditioner according to this modification, the target evaporation temperature is not set during the washing process. On the other hand, in the air conditioner according to this modification, the lower limit of the evaporation temperature at the time of washing with water is set. The lower limit of the evaporation temperature during the washing process is set to a temperature (for example, 5 ° C.) at which the condensed water generated on the surface of the indoor heat exchanger 13 does not freeze.

Similar to the air conditioner 1 according to the above embodiment, the air conditioner 1 according to the present modification suitably cleans the indoor heat exchanger 13 while suppressing a decrease in the heat exchange efficiency of the indoor heat exchanger 13. be able to.

(7-7) Modification 1G
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the cleaning operation according to the present disclosure is not limited to this, and for example, in the frost formation treatment, the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a is set to be equal to or lower than the freezing temperature, so that the auxiliary heat exchanger is used. It may be a second frosting treatment, which is a treatment for frosting the dew condensation water generated on the surface of 13a.

The washing operation according to this modification is carried out by the second frost formation treatment and the first water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a fourth cleaning operation.

In the fourth washing operation, after frost is formed on the surface of the auxiliary heat exchanger 13a by the second frost treatment, the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b are washed by the dew condensation water by the first water washing treatment. (See FIG. 9). As described above, the area where the frost formation treatment is performed is shown by horizontal line hatching, and the area where the water washing treatment is performed is shown by vertical line hatching.

In the fourth cleaning operation, the cleaning operation control unit 46 determines the frequency of the compressor 101, the opening degree of the expansion valve 104, and the indoor fan 14 so that the temperature of the refrigerant flowing through the auxiliary heat exchanger 13a is equal to or lower than the freezing temperature. Controls the number of revolutions of.

Specifically, the cleaning operation control unit 46 sets the target evaporation temperature of the auxiliary heat exchanger 13a to −5 to −10 ° C., stops the operation of the indoor fan 14, narrows the opening degree of the expansion valve 104, and compresses the compressor. The second frost formation process is performed by controlling the frequency of 101 to 5 to 10 Hz. However, the above control is an example and can be changed as appropriate. Therefore, the target evaporation temperature of the auxiliary heat exchanger 13a is set to −5 to −10 ° C., the indoor fan 14 is driven at a low rotation speed, the opening degree of the expansion valve 104 is narrowed, and the frequency of the compressor 101 is set to 15 to 25 Hz. The fourth cleaning operation may be carried out by controlling the frequency.

In the air conditioner according to the present modification, the indoor heat exchanger 13 can be suitably cleaned even when the atmosphere in the air-conditioned space is dry.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-8) Modification 1H
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the washing operation according to the present disclosure is not limited to this, and for example, the washing operation may be carried out by the second frost formation treatment and the second water washing treatment.

The washing operation according to this modification is carried out by the second frost formation treatment and the second water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a fifth cleaning operation.

In the fifth washing operation, after frost is formed on the surface of the auxiliary heat exchanger 13a by the second frost treatment, the surface of the auxiliary heat exchanger 13a is washed by the dew condensation water by the second water washing treatment (see FIG. 10). ). As described above, the area where the frost formation treatment is performed is shown by horizontal line hatching, and the area where the water washing treatment is performed is shown by vertical line hatching.

In the air conditioner according to the present modification, the indoor heat exchanger 13 can be suitably cleaned even when the atmosphere in the air-conditioned space is dry.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-9) Modification 1I
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the washing operation according to the present disclosure is not limited to this, and for example, the washing operation may be carried out by the second frost formation treatment and the third water washing treatment (FIG. 11). reference).

The washing operation according to this modification is carried out by the second frost formation treatment and the third water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a sixth cleaning operation.

In the sixth washing operation, after frost is formed on the surface of the auxiliary heat exchanger 13a by the second frost treatment, the surface of a part of the region in the auxiliary heat exchanger 13a is washed by the dew condensation water by the third water washing treatment. (See FIG. 11). As described above, the area where the frost formation treatment is performed is shown by horizontal line hatching, and the area where the water washing treatment is performed is shown by vertical line hatching.

In the air conditioner according to the present modification, the indoor heat exchanger 13 can be suitably cleaned even when the atmosphere in the air-conditioned space is dry.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-10) Modification 1J
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the cleaning operation according to the present disclosure is not limited to this, and for example, in the cleaning operation, the temperature of the refrigerant flowing in a part of the auxiliary heat exchanger 13a is set to be equal to or lower than the freezing temperature of the auxiliary heat exchanger. It may be carried out by a third frost treatment that causes frost formation in a part of the region in 13a and a first water washing treatment (see FIG. 12).

The washing operation according to this modification is carried out by the third frost formation treatment and the first water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a seventh cleaning operation.

In the seventh washing operation, after frost formation occurs on the surface of a part of the auxiliary heat exchanger 13a by the third frost treatment, the auxiliary heat exchanger 13a and the main heat exchanger 13b are condensed by the first water washing treatment. Washed with water (see Figure 12). As described above, the area where the frost formation treatment is performed is shown by horizontal line hatching, and the area where the water washing treatment is performed is shown by vertical line hatching.

In the air conditioner according to the present modification, the indoor heat exchanger 13 can be suitably cleaned even when the atmosphere in the air-conditioned space is dry.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-11) Modification 1K
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the washing operation according to the present disclosure is not limited to this, and for example, the washing operation may be carried out by the third frost formation treatment and the second water washing treatment (FIG. 13). reference).

The washing operation according to this modification is carried out by the third frost formation treatment and the second water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as an eighth cleaning operation.

In the eighth washing operation, after frost formation occurs on the surface of a part of the auxiliary heat exchanger 13a by the third frost treatment, the auxiliary heat exchanger 13a is washed by the dew condensation water by the second water washing treatment ( See FIG. 13). As described above, the area where the frost formation treatment is performed is shown by the hatching of the horizontal line, and the area where the washing treatment is performed is shown by the hatching of the vertical line. Even when the atmosphere in the room is dry, the indoor heat exchanger 13 can be suitably cleaned.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

(7-12) Modification 1L
In the above embodiment, the first cleaning operation for cleaning the surfaces of the auxiliary heat exchanger 13a and the main heat exchanger 13b by performing the first frost formation treatment and the first water washing treatment has been described. However, the example of the washing operation according to the present disclosure is not limited to this, and for example, the washing operation may be carried out by a third frost formation treatment and a third water washing treatment (FIG. 14). reference).

The washing operation according to this modification is carried out by the third frost formation treatment and the third water washing treatment. Hereinafter, the cleaning operation according to this modification is referred to as a ninth cleaning operation.

In the ninth washing operation, after frost formation occurs on the surface of a part of the region of the auxiliary heat exchanger 13a by the third frost treatment, the surface of a part of the region of the auxiliary heat exchanger 13a is removed by the second water washing treatment. It is washed with dew condensation water (see FIG. 14). As described above, the area where the frost formation treatment is performed is shown by the hatching of the horizontal line, and the area where the washing treatment is performed is shown by the hatching of the vertical line. Even when the atmosphere in the room is dry, the indoor heat exchanger 13 can be suitably cleaned.

Further, the air conditioner according to the present modification can suppress a decrease in the heat exchange efficiency of the indoor heat exchanger 13 as in the air conditioner 1 according to the above embodiment.

<Other embodiments>
Although the embodiments according to the present disclosure have been described above, it will be understood that various modifications of the embodiments and details are possible without departing from the spirit and scope of the claims.

The present disclosure is not limited to each of the above embodiments as they are. In the present disclosure, the components can be modified and embodied within the range that does not deviate from the gist at the implementation stage. Further, the present disclosure can form various disclosures by appropriately combining the plurality of components disclosed in each of the above embodiments. For example, some components may be removed from all the components shown in the embodiments. Further, the components may be appropriately combined in different embodiments. Therefore, it should be considered that the present embodiment is merely an example in all respects and is not limited thereto, and it is intended that all modifications that are obvious to those skilled in the art are included in the embodiment.

1 Air conditioner 13 Indoor heat exchanger 40 Control unit 42 Cooling operation 44 1st operation 45 2nd operation 46 Washing operation 47 Frost treatment 48 Water washing treatment 101 Compressor 104 Expansion valve

Japanese Unexamined Patent Publication No. 2018-189262

Claims (8)

A refrigerant circuit (200) including an indoor heat exchanger (13) and
A control unit (40) that performs a cleaning operation, which is an operation of cleaning the indoor heat exchanger when cleaning of the indoor heat exchanger is required.
Equipped with
The control unit
In the cleaning operation, dew condensation is formed on the surface of the indoor heat exchanger and further frosts the indoor heat exchanger, and after the frosting treatment, dew condensation is formed on the surface of the indoor heat exchanger. A water washing treatment for washing the surface of the indoor heat exchanger with condensed water is carried out.
Air conditioner (1). In the frost formation treatment, the dew condensation water is frozen by lowering the temperature of the refrigerant flowing through the indoor heat exchanger to a temperature equal to or lower than the temperature at which the moisture contained in the indoor air can be frozen in the indoor heat exchanger.
The water washing treatment causes the dew condensation at a refrigerant temperature higher than the refrigerant temperature at the time of the frost formation treatment.
The air conditioner according to claim 1. Expansion valve (104)
Further prepare
The control unit adjusts the opening degree of the expansion valve to control the temperature of the refrigerant flowing through the indoor heat exchanger.
The air conditioner according to claim 1 or 2. The target evaporation temperature during the frost formation treatment is lower than the target evaporation temperature during the water washing treatment.
The air conditioner according to any one of claims 1 to 3. The amount of dehumidification from the indoor air by the frosting treatment is smaller than the amount of dehumidification from the indoor air by the washing treatment.
The air conditioner according to any one of claims 1 to 4. The implementation time of the frost formation treatment is shorter than the implementation time of the water washing treatment.
The air conditioner according to any one of claims 1 to 5. Compressor (101),
Further prepare
The compressor is continuously operated during the frost formation treatment and the water washing treatment.
The air conditioner according to any one of claims 1 to 6. A predetermined time is allowed between the frost formation treatment and the water washing treatment.
The air conditioner according to any one of claims 1 to 6.

Images