CN111279133A - Air conditioner - Google Patents

Abstract

An air conditioner (100) is provided with: a Refrigeration Cycle (RC) having a compressor (32) and an indoor heat exchanger (64); a drain pan (140) for temporarily storing water that has fallen while adhering to the indoor heat exchanger as drain water; a drain Pump (PO) for discharging the drain water stored in the drain pan to the outside; and a control device (20) for controlling the actions of the refrigeration cycle and the drainage pump. The control device executes a freezing operation in which the indoor heat exchanger functions as an evaporator and the surface temperature of the indoor heat exchanger is below the freezing point, and drives the drain pump so as to satisfy a relationship of "drive time of the drain pump after completion of a normal cooling operation < drive time of the drain pump after the freezing operation".

Description

Air conditioner

Technical Field

The present invention relates to an air conditioner.

Background

A drain pan that temporarily stores water that has fallen down while adhering to an indoor heat exchanger is provided inside an indoor unit of an air conditioner. Hereinafter, the water stored in the drain pan is referred to as "drain". The drain water is drained to the outside through the pipe, but if the drain water is not properly drained, the drain water remains in the drain pan. This may cause foreign odor and rust. Therefore, there is an air conditioner including a drain pump for forcibly discharging drain water to the outside in an indoor unit of the air conditioner (see, for example, patent document 1).

On the other hand, the air conditioner performs a so-called "freeze washing operation". The "freeze cleaning operation" is an operation of: ice (including frost) is attached to the surface of the indoor heat exchanger, then the ice is thawed (dissolved), and fine dust attached to the indoor heat exchanger is caused to flow down by the water potential of the water falling therefrom.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-25355

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional air conditioner, it is not considered that the drain pump is driven in association with the freeze washing operation. Therefore, in the conventional air conditioner, it is unclear which kind of drive control of the drain pump is performed to reliably reduce the residual amount of drain water when the freeze washing operation is performed.

The present invention has been made to solve the above problems, and a main object thereof is to provide an air conditioner in which the residual amount of drainage in the case where freeze washing operation is performed is reduced.

In order to achieve the above object, the present invention provides an air conditioner including a refrigeration cycle including a compressor for compressing a refrigerant and an indoor heat exchanger, a drain pan for temporarily storing water adhering to the indoor heat exchanger and dropping as drain water, a drain pump for discharging the drain water stored in the drain pan to the outside, and a control device for controlling operations of the refrigeration cycle and the drain pump, wherein the control device performs a freezing operation for causing the indoor heat exchanger to function as an evaporator and setting a surface temperature of the indoor heat exchanger to be below a freezing point, and drives the drain pump so as to satisfy a relationship "a driving time of the drain pump after a normal cooling operation is ended < a driving time of the drain pump after the freezing operation".

Other schemes are described later.

Effects of the invention

According to the present invention, the residual amount of drainage in the case where the freeze washing operation is performed can be reduced.

Drawings

Fig. 1 is a system diagram of an air conditioner according to an embodiment.

Fig. 2 is a side sectional view of an indoor unit of an air conditioner according to an embodiment.

Fig. 3 is a flowchart showing an operation in the freeze-washing operation of the air conditioner according to the embodiment.

Fig. 4 is a flowchart showing an operation in the freeze-washing operation of the air conditioner according to the embodiment.

Fig. 5 is a flowchart showing an operation of a first modification of the air conditioner.

Fig. 6 is a flowchart showing an operation of a second modification of the air conditioner.

Detailed Description

Embodiments of the present invention (hereinafter referred to as "the present embodiments") will be described in detail below with reference to the drawings. The drawings are merely schematic representations to the extent that the present invention can be fully understood. Thus, the present invention is not limited to the illustrated examples. In the drawings, the same reference numerals are given to the common components and the same components, and redundant description thereof will be omitted.

[ embodiment ]

< construction of air conditioner >

Next, the structure of the air conditioner 100 according to the present embodiment will be described with reference to fig. 1. Fig. 1 is a system diagram of an air conditioner 100 according to the present embodiment.

As shown in fig. 1, the air conditioner 100 includes an outdoor unit 30, an indoor unit 60, and a control device 20 for controlling these units. The indoor unit 60 sets an operation mode (cooling, heating, dehumidification, ventilation, etc.), an indoor air volume (fast wind, strong wind, weak wind, etc.), a target indoor temperature, and the like, based on a signal input from the remote control 90.

(Structure of control device)

The control device 20 includes hardware of a general computer such as a CPU (central Processing unit), a dsp (digital signal processor), a ram (random Access memory), and a ROM (read Only memory), and stores a control program executed by the CPU and various data in the ROM. The control device 20 controls the outdoor unit 30 and each unit of the indoor unit 60 based on a control program. The details thereof will be described later.

(Structure of outdoor machine)

The outdoor unit 30 includes a compressor 32, a four-way valve 34, and an outdoor heat exchanger 36. The compressor 32 includes a motor 32a and has a function of compressing the refrigerant flowing in through the four-way valve 34. The pipe a1 is provided with a suction-side temperature sensor 41 for detecting the temperature of the refrigerant sucked into the compressor 32, and a suction-side pressure sensor 45 for detecting the pressure of the refrigerant sucked into the compressor 32. The pipe a2 is provided with a discharge side temperature sensor 42 that detects the temperature of the refrigerant discharged from the compressor 32, and a discharge side pressure sensor 46 that detects the pressure of the refrigerant discharged from the compressor 32. Further, a compressor temperature sensor 43 that detects the temperature of the compressor 32 is attached to the compressor 32.

The four-way valve 34 has a function of switching the direction of the refrigerant supplied to the indoor unit 60 depending on whether the indoor heat exchanger 64 of the indoor unit 60 functions as an evaporator or a condenser. When the indoor heat exchanger 64 functions as an evaporator, for example, during a cooling operation, the four-way valve 34 is switched so that the pipes a2 and a3 are connected along the solid-line path and the pipes a1 and a6 are connected. In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 32 is cooled by the outdoor heat exchanger 36. The cooled refrigerant is supplied to the indoor unit 60 through the pipe a 5.

When the indoor heat exchanger 64 functions as a condenser, for example, during heating operation, the four-way valve 34 is switched so as to connect the pipes a2, 66 and the pipes a1, a3 along the path indicated by the broken line. In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 32 is supplied to the indoor unit 60 through the pipes a2 and a 6. The outdoor fan 48 includes a motor 48a and blows air to the outdoor heat exchanger 36.

The outdoor heat exchanger 36 is a heat exchanger that performs heat exchange between the air sent from the outdoor fan 48 and the refrigerant, and is connected to the compressor 32 via the four-way valve 34. The outdoor unit 30 is provided with an outdoor heat exchanger inlet temperature sensor 51 for detecting the temperature of the air flowing into the outdoor heat exchanger 36, an outdoor heat exchanger refrigerant gas temperature sensor 53 for detecting the temperature of the gas-side refrigerant in the outdoor heat exchanger 36, and an outdoor heat exchanger refrigerant liquid temperature sensor 55 for detecting the temperature of the liquid-side refrigerant in the outdoor heat exchanger 36.

The power supply unit 54 receives a three-phase ac voltage from the commercial power supply 22. The power measuring unit 58 is connected to the power supply unit 54, thereby measuring the power consumption of the air conditioner 100. The dc voltage output from the power supply unit 54 is supplied to the motor control unit 56. The motor controller 56 includes an inverter (not shown) and supplies an ac voltage to the motor 32a of the compressor 32 and the motor 48a of the outdoor fan 48. The motor control unit 56 detects the rotational speed of the motors 32a and 48a by controlling the motors 32a and 48a without a sensor.

(Structure of indoor machine)

The indoor unit 60 includes an indoor expansion valve 62, an indoor heat exchanger 64, an indoor fan 66, a motor control unit 67, and a remote control communication unit 68 that performs bidirectional communication with a remote control 90. The indoor fan 66 includes a motor 66a and blows air to the indoor heat exchanger 64. The motor control unit 67 includes a converter (not shown) and supplies an ac voltage to the motor 66 a. The motor control unit 67 detects the rotation speed of the motor 66a by controlling the motor 66a in a sensorless manner.

The indoor expansion valve 62 is inserted between the pipes a5 and a7, and has a function of adjusting the flow rate of the refrigerant flowing through the pipes a5 and a7 and decompressing the refrigerant on the secondary side of the indoor expansion valve 62. The indoor heat exchanger 64 is a heat exchanger that performs heat exchange between the indoor air sent from the indoor fan 66 and the refrigerant, and is connected to the indoor expansion valve 62 through a pipe a 7.

The indoor unit 60 includes an indoor heat exchanger inlet air temperature sensor 70, an indoor heat exchanger discharge air temperature sensor 72, an indoor heat exchanger inlet humidity sensor 74, an indoor heat exchanger refrigerant liquid temperature sensor 25, and an indoor heat exchanger refrigerant gas temperature sensor 26.

Here, the indoor heat exchanger inlet air temperature sensor 70 detects the temperature of the air taken in by the indoor fan 66. In addition, the indoor heat exchanger discharge air temperature sensor 72 detects the temperature of the air discharged from the indoor heat exchanger 64.

In addition, the indoor heat exchanger inlet humidity sensor 74 detects the humidity of the air drawn by the indoor fan 66. The indoor heat exchanger refrigerant liquid temperature sensor 25 and the indoor heat exchanger refrigerant gas temperature sensor 26 are provided at a connection point between the indoor heat exchanger 64 and the pipe a6, and detect the temperature of the refrigerant flowing therethrough. In this way, the compressor 32, the four-way valve 34, the outdoor heat exchanger 36, the indoor expansion valve 62, the indoor heat exchanger 64, and the pipes a1 to a7 form a refrigeration cycle RC.

< construction of indoor Unit >

Next, the structure of the indoor unit 60 will be described with reference to fig. 2. Fig. 2 is a side sectional view of the indoor unit 60. In the present embodiment, a case where the indoor unit 60 is a ceiling-mounted type device will be described. The ceiling installation type is a structure that is embedded in the ceiling 130 and exposes the lower surface to the air conditioning room. However, the indoor unit 60 may be a wall-mounted type, a ceiling-embedded type, a floor-mounted type, or the like.

As shown in fig. 2, the indoor heat exchanger 64 is formed in a plate shape bent in a substantially V-shape, and is provided at the center of the indoor unit 60. The indoor fan 66 has fins arranged in a substantially cylindrical shape and is disposed in front of the indoor heat exchanger 64. A drain pan 140 that temporarily stores water condensed and dropped on the surfaces of the indoor heat exchanger 64 and the indoor fan 66 is disposed below these heat exchangers. Hereinafter, the water stored in the drain pan 140 is referred to as "drain". The indoor unit 60 is provided with a drain pump PO for forcibly discharging the drain water stored in the drain pan 140 to the outside. In the present embodiment, a configuration in which the volume of the drain pan 140 is approximately the same as or slightly smaller than the assumed generation amount of drain water generated in a short time in the freeze-washing operation described later will be described.

An inclined air filter 142 is provided behind the indoor heat exchanger 64. The lower surface of the indoor unit 60 is covered with a decorative panel 143. An air inlet 144 formed by cutting a slit in the decorative plate 143 is formed below the air filter 142. The indoor heat exchanger inlet air temperature sensor 70 is disposed between the indoor heat exchanger 64 and the air filter 142.

An air blowing duct 146 is formed in front of the indoor fan 66. The horizontal air vanes 148 are provided midway in the air blowing duct 146, and control the direction of the air flow in the horizontal direction (the direction perpendicular to the paper surface). The up-down wind direction plate 150 is provided at an outlet portion of the air blowing duct 146, and rotates about a fulcrum 150a to control the direction of the airflow in the up-down direction. The horizontal wind direction plate 148 and the vertical wind direction plate 150 are rotationally driven by the control device 20 (see fig. 1). The vertical vanes 150 shown by solid lines in fig. 2 are shown at positions in the fully opened state.

When the air conditioner 100 is stopped, the up-down wind direction plate 150 rotates to a fully closed position 152 indicated by a one-dot chain line. When a cleaning operation described later is performed, the up-down wind deflector 150 is rotated to a position 156 indicated by a one-dot chain line, and then rotated to a cleaning operation position 154. The duct resistance of the air blowing duct 146 decreases as the opening degree of the up-down wind direction plate 150 increases. However, even when the up-down wind deflector 150 is closed at the full-close position 152, a gap FS is formed between the up-down wind deflector 150 and the decorative plate 143, and some air flows through the gap FS.

In the present embodiment, for example, when the interior of the indoor unit 60 needs to be cleaned, a cleaning lamp (not shown) for showing this is provided on the decorative plate 143. Further, a suction panel (not shown) for selectively sucking air into the air-conditioned room is provided between the air suction port 144 and the air filter 142.

< operation of air conditioner during freezing and washing operation >

The air conditioner 100 of the present embodiment can perform freeze cleaning operation. The "freeze cleaning operation" is an operation of: ice (including frost) is attached to the surface of the indoor heat exchanger 64, then the ice is thawed (dissolved), and fine dust attached to the indoor heat exchanger 64 is caused to flow down by the water potential of the water falling therefrom. In the "freeze washing operation", a larger amount of drain water than in the normal cooling operation is generated in a short time.

Next, the operation of the air conditioner 100 during the freeze-washing operation will be described with reference to fig. 3 and 4. Fig. 3 is a flowchart showing the operation of the air conditioner 100 during the operation cleaning operation. Fig. 4 is a flowchart showing an operation during the freeze-wash operation of the air conditioner 100.

The processing in the sequence shown in fig. 3 is executed under the control of the control device 20 in response to a freezing operation request generated when the execution of the freezing and washing operation is instructed by the user operating the remote control 90 or when the timing for automatically performing the freezing and washing operation is reached.

As shown in fig. 3, when the freeze operation request is generated, the freeze cleaning operation is started.

Then, the control device 20 determines whether or not the freezing operation is possible (step S105). If it is determined in step S105 that the freeze operation cannot be performed (no), the freeze cleaning operation is stopped (step S110). On the other hand, if it is determined in step S105 that the freezing operation is possible (yes), the controller 20 drives the drain pump PO (step S115). Further, since the drain is generated at the initial stage of the freezing operation, the drain pump PO can be driven at the initial stage of the freezing operation.

Next, the control device 20 starts the freezing operation (step S120), and then stops the freezing operation when a desired time has elapsed (when sufficient ice adheres to the indoor heat exchanger 64) (step S125). Next, the controller 20 starts the defrosting operation for allowing dust on the surface of the indoor heat exchanger 64 to flow down (step S130), and then stops the drain pump PO when a time is desired for the period of time (step S135), and starts the drying operation (step S140). After that, when the desired time has elapsed, the control device 20 stops the series of processes (the process of the freeze cleaning operation). The process of step S135 (the stop process of the drain pump PO) may be deleted according to the operation or may be shifted to step S140 (the process of the drying operation).

Fig. 4 shows an example of a case where the freeze washing operation is performed by insertion during the normal cooling operation. In the example shown in fig. 4, the respective processes of the operation stop "process," compressor protection "operation," blowing "operation, and" freeze washing "operation (of the normal cooling operation) are performed in order. In the "freeze washing" operation, the respective processes of the "freeze" operation, the "thawing" operation, and the "drying" operation are performed. In the "drying" operation, each process of the "air blowing" operation, the "heating" operation, and the "heat radiation" operation is performed.

The "compressor protection" operation is an operation for stopping the driving of the compressor 32 to protect the compressor 32. The compressor 32 stops driving to drop the lubricant oil floating in the internal space toward an oil reservoir (not shown), so that the lubricant oil does not flow out of the compressor 32. The "blowing" operation is an operation of driving the indoor fan 66 to blow air to the indoor heat exchanger 64. The "freezing" operation is an operation of lowering the temperature of the indoor heat exchanger 64 and causing ice to adhere to the surface of the indoor heat exchanger 64. The "defrosting" operation is an operation of raising the temperature of the indoor heat exchanger 64 to defrost (dissolve) the ice adhering to the indoor heat exchanger 64 and cause dust on the surface of the indoor heat exchanger 64 to flow down. The "drying" operation is an operation for drying the surface of the indoor heat exchanger 64. The "heating" operation is an operation for increasing the temperature of the indoor heat exchanger 64. The "heat radiation" operation is an operation for radiating heat of the indoor heat exchanger 64 to the surroundings.

In the example shown in fig. 4, the following processing is performed.

First, the "operation stop" process from the cooling operation is performed from time t0 to time t 1.

Further, the "compressor protection" operation is performed from time t1 to time t 2.

Further, the "blowing" operation is performed from time t2 to time t 3.

The "freeze" operation is performed from time t3 to time t 5.

The "defrosting" operation is performed from time t5 to time t 6.

Further, the "blowing" operation is performed from time t6 to time t 7.

Further, the "heating" operation is performed from time t7 to time t 8.

Further, the "heat radiation" operation is performed from time t8 to time t 9.

Further, after time t9, the "blowing" operation is performed.

The "freeze cleaning" operation is performed from time t3 to time t 9.

Further, the "drying" operation is performed from time t6 to time t 9.

The following state is achieved in the "operation stop" from the time t0 to the time t 1. The indoor fan 66, the outdoor fan 48, and the compressor 32 that have operated during the cooling operation up to time t0 stop driving. The up-down wind direction plate 150 is lowered (opened) downward at an arbitrary angle. The suction panel (not shown) is opened at an arbitrary angle. The purge lamp (not shown) is turned on. The drain pump PO is driven.

Next, the components of the state change will be described with respect to each operation.

In the "compressor protection" operation from time t1 to time t2, the indoor fan 66 and the outdoor fan 48 are driven at desired rotational speeds, respectively. The inclination of the up-down wind direction plate 150 is set to an upward angle for freezing. Drain pump PO is driven from time t1 to time t1a, and stops driving at time t1 a. In addition, the time t1a is a time between the time t1 and the time t 2.

During the "blowing" operation from time t2 to time t3, the indoor fan 66 is continuously driven. The rotation speed of the indoor fan 66 during the "blowing" operation is faster than the rotation speed during the period from time t1 to time t2 (during the "compressor protection" operation) (the same applies hereinafter).

In the "freeze" operation from time t3 to time t5, the indoor fan 66 is driven to time t4, and the driving is stopped at time t 4. The outdoor fan 48 is driven to time t5, and stops driving at time t 5. The compressor 32 is driven to the time t5, and the driving is stopped at the time t 5. The rotation speed of the indoor fan 66 in the "freezing" operation is faster than the rotation speed in the period from the time t1 to the time t2 (the period during the "compressor protection" operation), and is slower than the rotation speed in the period from the time t2 to the time t3 (the period during the "blowing" operation). The rotation speed of the outdoor fan 48 in the "freezing" operation is faster than the rotation speed during the period from time t1 to time t3 (the period during the "compressor protection" operation and the "blowing" operation).

In the "defrosting" operation from time t5 to time t6, the indoor fan 66, the outdoor fan 48, and the compressor 32 are stopped from driving.

During the "blowing" operation from time t6 to time t7, the indoor fan 66 is driven to set the tilt of the up-down wind direction plate 150 to the freezing-dedicated downward angle.

During the "heating" operation from time t7 to time t8, the indoor fan 66 is continuously driven, and the driving is stopped at time t 8. The outdoor fan 48 is driven to time t8, and stops driving at time t 8. The rotation speed of the outdoor fan 48 during the "heating" operation is faster than the rotation speed during the period from time t1 to time t3 (during the "compressor protection" operation and the "blowing" operation), and is slower than the rotation speed during the period from time t3 to time t5 (during the "freezing" operation).

In the "heat radiation" operation from time t8 to time t9, the indoor fan 66, the outdoor fan 48, and the compressor 32 are stopped from driving.

During the "blowing" operation after time t9, the indoor fan 66 is driven.

< main characteristics of air conditioner >

The air conditioner 100 of the present embodiment has the following features.

(1) As shown in fig. 4, the control device 20 performs a freezing operation in which the indoor heat exchanger 64 functions as an evaporator and the surface temperature of the indoor heat exchanger 64 is below the freezing point, and drives the drain pump PO so as to satisfy the relationship "the drive time of the drain pump after the normal cooling operation is completed < the drive time of the drain pump after the freezing operation".

In the example shown in fig. 4, the "driving time of the drain pump after the end of the normal cooling operation" is a time from time t1 to time t1 a. The "driving time of the drain pump after the freezing operation" is a time after time t 5.

In the "freeze washing operation", a larger amount of drain water than in the normal cooling operation is generated in a short time. The air conditioner 100 according to the present embodiment can efficiently and reliably discharge the drain water to the outside by driving the drain pump PO so as to satisfy the above-described relationship. Therefore, the air conditioner 100 of the present embodiment can reliably reduce the residual amount of drainage in the case where the freeze washing operation is performed. The air conditioner 100 of the present embodiment can prevent drainage from being discharged from the drain pan 140, and can suppress generation of offensive odor and rust caused by drainage remaining in the drain pan 140.

(2) Preferably, controller 20 executes a defrosting operation after the freezing operation is finished, and drives drain pump PO for at least a part of the defrosting operation. Thus, the air conditioner 100 of the present embodiment can reduce the residual amount of drainage in the case where the freeze washing operation is performed.

(3) Preferably, the controller 20 executes the drying operation after the freezing operation is finished, and can drive the drain pump PO during at least a part of the defrosting operation and the drying operation. Thus, the air conditioner 100 of the present embodiment can more effectively reduce the residual amount of drainage when the freeze-wash operation is performed.

(4) The control device 20 preferably drives the drain pump PO during the driving of the indoor fan 66 in the drying operation.

In the indoor unit 60, while the indoor fan 66 is driven, water generated during thawing of ice adhering to the indoor heat exchanger 64 falls down to the drain pan 140, and there is a possibility that drain water stays in the drain pan 140. Therefore, the air conditioner 100 of the present embodiment drives the drain pump PO while the indoor fan 66 is driven in the drying operation. Thus, the air conditioner 100 of the present embodiment can effectively and reliably reduce the residual amount of drainage when the freeze-wash operation is performed.

(5) The control device 20 preferably turns on the drive of the drain pump PO continuously for at least a part of the freezing operation, the thawing operation, and the drying operation.

The drain pump PO generates a relatively loud sound at the time of switching on/off of the drive. Therefore, the control device 20 of the air conditioner 100 according to the present embodiment continuously turns on the drive of the drain pump PO for at least a part of the freezing operation, the defrosting operation, and the drying operation. Thus, the air conditioner 100 of the present embodiment can reduce the generation of noise due to the drain pump PO.

(6) Preferably, the controller 20 stops the drain pump PO after a predetermined time or more has elapsed after the end of the normal cooling operation, and then continuously stops the drain pump PO until the freezing operation is started. Thus, the air conditioner 100 of the present embodiment can secure the time for stopping the drain pump PO. Therefore, the air conditioner 100 of the present embodiment can achieve a reduction in energy consumption, that is, energy saving, by that amount.

(7) Preferably, the controller 20 continues to drive the drain pump PO for a predetermined time or more even after the drying operation is completed. In the example shown in fig. 4, "after the end of the drying operation" indicates time t9 and thereafter. The air conditioner 100 of the present embodiment can discharge substantially all of the drain water remaining in the drain pan 140 to the outside by continuing to drive the drain pump PO for a certain time or more even after the drying operation is completed. Therefore, the air conditioner 100 of the present embodiment can effectively and reliably reduce the residual amount of drainage in the case where the freeze washing operation is performed.

As described above, according to the air conditioner 100 of the present embodiment, the residual amount of drainage in the case where the freeze washing operation is performed can be reduced.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

For example, the above embodiments are described to easily explain the gist of the present invention. Therefore, the present invention is not limited to the embodiment that necessarily includes all the components described above. In the present invention, another component may be added to a certain component or a part of the components may be replaced with another component. In the present invention, some of the components may be deleted.

For example, in the above-described embodiment, a description is given of an embodiment in which the indoor unit 60 is a ceiling-mounted device. However, the present invention can be applied to devices such as wall-mounted devices, ceiling-embedded devices, and floor-mounted devices.

For example, the operation of the air conditioner 100 may be modified as a first modification shown in fig. 5 and a second modification shown in fig. 6. Fig. 5 is a flowchart showing an operation of the first modification of the air conditioner 100. Fig. 6 is a flowchart showing an operation of a second modification of the air conditioner 100.

(first modification)

The operation of the first modification shown in fig. 5 is an operation in the case where a stop operation by a user is received during the freeze operation. The operation of the first modification shown in fig. 5 differs from the operation of the above-described embodiment shown in fig. 4 in that the stop operation is received to stop the indoor fan 66.

As shown in fig. 5, in the operation of the first modification, the time from the end of the operation in the normal cooling operation to the start of driving of the discharge pump PO (i.e., the time from time T1a to time T3 at which the discharge pump PO is stopped) is T11. On the other hand, the time from the reception of the stop operation until the start of the driving of the drain pump PO (i.e., the time from the time tA to the time tB) is T12. Also, the time T12 is a value greater than the time T11 (i.e., a value satisfying the relationship "T12 > T11"). That is, in the operation of the first modification, the time from the stop operation to the start of driving of the drain pump PO when the stop operation by the user is received in the freezing operation is longer than the time from the end of the operation in the normal cooling operation to the start of driving of the drain pump PO.

The operation of the first modification ensures a time period for the lubricant oil floating in the internal space of the compressor 32 to fall in the direction of the oil reservoir (not shown). Thus, the operation of the first modification can suppress the lubricating oil floating in the internal space of the compressor 32 from flowing out of the compressor 32 to lower the operation efficiency of the refrigeration cycle RC.

(second modification)

The operation of the second modification shown in fig. 6 is an operation in a case where the drain pan 140 has a size enough to store the drain generated in a short time during the freeze-washing operation without overflowing. The operation of the second modification shown in fig. 6 differs from the operation of the above-described embodiment shown in fig. 4 in that the drain pump PO is stopped for at least a part of the drying operation.

The operation of the second modification ensures a time for stopping the drain pump PO. Therefore, the operation of the second modification can reduce the energy consumption, that is, save energy. In addition, the operation of the second modification can suppress the generation of noise at the time when the drain pump PO is stopped.

Description of the symbols

20-a control device, 22-a commercial power supply, 25-an indoor heat exchanger refrigerant liquid temperature sensor, 26-an indoor heat exchanger refrigerant gas temperature sensor, 30-an outdoor unit, 32-a compressor, 32a, 48a, 66 a-a motor, 34-a four-way valve, 36-an outdoor heat exchanger, 41-a suction side temperature sensor, 42-a discharge side temperature sensor, 43-a compressor temperature sensor, 45-a suction side pressure sensor, 46-a discharge side pressure sensor, 48-an outdoor fan, 51-an outdoor heat exchanger inlet temperature sensor, 53-an outdoor heat exchanger refrigerant gas temperature sensor, 54-a power supply portion, 55-an outdoor heat exchanger refrigerant liquid temperature sensor, 56, 67-a motor control portion, 58-an electric power measurement portion, 60-an indoor unit, 62-an indoor expansion valve, 64-an indoor heat exchanger, 66-an indoor fan, 68-remote control communication part, 70-indoor heat exchanger inlet air temperature sensor, 72-indoor heat exchanger discharge air temperature sensor, 74-indoor heat exchanger inlet temperature sensor, 90-remote control, 100-air conditioner, 130-ceiling, 140-drain pan, 142-air filter, 143-decorative panel, 144-air intake, 146-air blow-out channel, 148-left and right wind direction panel, 150-up and down wind direction panel, 150 a-fulcrum, 152-full close position, 154-cleaning operation position, 156-position, a1, a2, a3, a5, a6, a 7-piping, FS-gap, PO-drain pump, RC-refrigeration cycle.

Claims (9)

1. An air conditioner is characterized by comprising:

a refrigeration cycle having a compressor for compressing a refrigerant and an indoor heat exchanger;

a drain pan for temporarily storing water that has fallen while adhering to the indoor heat exchanger as drain water;

a drain pump for discharging the drain water stored in the drain pan to the outside; and

a control device for controlling the refrigeration cycle and the action of the drainage pump,

the control device executes a freezing operation in which the indoor heat exchanger functions as an evaporator and the surface temperature of the indoor heat exchanger is below the freezing point, and drives the drain pump so as to satisfy a relationship of "drive time of the drain pump after completion of a normal cooling operation < drive time of the drain pump after the freezing operation".

2. The air conditioner according to claim 1,

the control device executes the defrosting operation after the freezing operation is finished,

and driving the drain pump for at least a part of the defrosting operation.

3. The air conditioner according to claim 2,

the control device executes the drying operation after the freezing operation is finished,

the drain pump is driven for at least a part of the time during the defrosting operation and the drying operation.

4. An air conditioner according to claim 3,

is provided with an indoor fan, a fan body,

the control device drives the drain pump while the indoor fan is driven in the drying operation.

5. An air conditioner according to claim 3,

the control device keeps on driving the drain pump for at least a part of the freezing operation, the thawing operation, and the drying operation.

6. The air conditioner according to claim 1,

when the normal cooling operation is finished, the control device stops the drain pump after a predetermined time or more has elapsed, and then stops the drain pump until the freezing operation is started.

7. The air conditioner according to claim 4,

the control device drives the drain pump continuously for a certain time or more even after the drying operation is finished.

8. The air conditioner according to claim 1,

the time from the stop operation to the start of driving of the drain pump when the stop operation by the user is received in the freezing operation is longer than the time from the end of the operation in the normal cooling operation to the start of driving of the drain pump.

9. An air conditioner is characterized by comprising:

a refrigeration cycle having a compressor for compressing a refrigerant and an indoor heat exchanger;

a drain pan for temporarily storing water that has fallen while adhering to the indoor heat exchanger as drain water;

a drain pump for discharging the drain water stored in the drain pan to the outside; and

a control device for controlling the refrigeration cycle and the action of the drainage pump,

the control device has a function of performing a freeze-washing operation including a freezing operation, a thawing operation, and a drying operation, and,

the drain pan has a size enough to store the drain generated in a short time during the defrosting operation without overflowing the drain,

the control device stops the drain pump for at least a part of the drying operation.

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