Air conditioner

Abstract

The invention relates to an air conditioner. An air conditioner according to an embodiment of the present invention may comprise: a compressor that compresses and discharges a refrigerant; an indoor heat exchanger for exchanging heat between the refrigerant and indoor air; a heat exchanger temperature sensor for sensing the temperature of the indoor heat exchanger; the indoor temperature sensor is used for sensing the indoor temperature; and a control unit. The control unit may perform a first control on the compressor on the basis of a first target temperature of the temperature of the indoor heat exchanger corresponding to the indoor temperature, and if the first control is completed, the first target temperature is the temperature of the indoor heat exchanger, and if the second target temperature is the temperature of the indoor heat exchanger. The control unit performs a second control on the compressor on the basis of a second target temperature lower than the temperature of the indoor heat exchanger below zero than the first target temperature if the first control is completed, and performs a second control on the compressor on the basis of a second target temperature lower than the temperature of the indoor heat exchanger below zero for a predetermined time if the second control is completed. The control unit sets the operation frequency of the compressor to a preset minimum frequency, and if the prescribed time has elapsed, the control unit determines whether or not to repeatedly execute the first control on the basis of a condition relating to the second control.

Description

Technical Field

[0001] The present invention relates to an air conditioner, and in particular to an air conditioner capable of removing foreign matter adsorbed on an indoor heat exchanger. Background Art

[0002] To create a comfortable indoor environment, air conditioners regulate the indoor temperature by blowing out low-temperature air into the room and purify the indoor air to provide a more comfortable indoor environment. Typically, an air conditioner consists of an indoor unit, which is composed of a heat exchanger and is installed indoors, and an outdoor unit, which is composed of a compressor, a heat exchanger, etc. and supplies refrigerant to the indoor unit.

[0003] Air conditioners operate in cooling or heating modes depending on the flow of refrigerant. During cooling, the outdoor unit's compressor supplies high-temperature, high-pressure liquid refrigerant to the indoor unit via the outdoor unit's heat exchanger. The refrigerant expands and vaporizes in the indoor unit's heat exchanger, cooling the surrounding air. The indoor fan rotates, expelling cool air into the room. During heating, the outdoor unit's compressor supplies high-temperature, high-pressure gas refrigerant to the indoor unit. The energy released by the liquefaction of the high-temperature, high-pressure gas refrigerant in the indoor unit's heat exchanger warms the air, which is then expelled into the room by the indoor fan.

[0004] Meanwhile, while the air conditioner is operating, foreign matter such as dust may become attached to the indoor unit's heat exchanger. For example, during cooling operation, heat exchange between the refrigerant and indoor air in the indoor unit's heat exchanger generates condensed water. If some of this condensed water condenses on the heat exchanger's surface or remains in the drain pipe, foreign matter may become attached to the condensed water.

[0005] As described above, when foreign matter is adsorbed on the heat exchanger of an indoor unit, etc., the foreign matter may cause the growth of microorganisms such as bacteria and mold, which not only causes discomfort to the user but also has an adverse effect on the user's health. Therefore, various studies are being conducted on the removal of foreign matter.

[0006] Conventional air conditioners, as described in Prior Art 1 (Japanese Patent Publication No. 2010-014288), use a refrigerant cycle to form frost on the surface of the indoor unit's heat exchanger, followed by a defrost operation to remove the frost. During this operation, water formed on the heat exchanger surface during the defrost operation flows and drains away, removing any foreign matter adhering to the indoor unit's heat exchanger.

[0007] In addition, in existing air conditioners, as shown in prior art 2 (Japanese Patent Publication No. 2018-200128), water droplets are condensed on the surface of the heat exchanger of the indoor unit before frost is formed on the surface of the heat exchanger, so that more water can be discharged when removing foreign matter. Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The present invention aims to solve the above-mentioned problems and other problems.

[0010] Still another object is to provide an air conditioner capable of effectively removing foreign matter adsorbed on an indoor heat exchanger simply by detecting temperature.

[0011] Still another object is to provide an air conditioner capable of preventing damage to a compressor that may occur during the removal of foreign matter adsorbed on an indoor heat exchanger.

[0012] Another object is to provide an air conditioner capable of more effectively removing foreign matter adsorbed on the indoor heat exchanger by repeating the operation of removing foreign matter adsorbed on the indoor heat exchanger in consideration of whether the foreign matter adsorbed on the indoor heat exchanger has been sufficiently removed.

[0013] Technical solutions to the problem

[0014] In order to achieve the above-mentioned purpose, an air conditioner of one embodiment of the present invention may include: a compressor, which compresses and discharges refrigerant; an indoor heat exchanger, which exchanges heat between the refrigerant and the indoor air; a heat exchanger temperature sensor, which senses the temperature of the indoor heat exchanger; an indoor temperature sensor, which senses the temperature in the room; and a control unit; the control unit may perform a first control on the compressor based on a first target temperature of the indoor heat exchanger corresponding to the temperature in the room; if the first control is completed, the control unit may perform a second control on the compressor based on a second target temperature of the indoor heat exchanger below zero which is lower than the first target temperature; if the second control is completed, the control unit sets the operating frequency of the compressor to a predetermined minimum frequency during a specified time period; if the specified time has passed, the control unit determines whether to repeat the first control based on conditions related to the second control.

[0015] Effects of the Invention

[0016] The effects of the air conditioner of the present invention are described below.

[0017] According to at least one embodiment of the present invention, foreign matter adsorbed on an indoor heat exchanger can be effectively removed simply by detecting temperature.

[0018] In addition, according to at least one embodiment of the present invention, it is possible to prevent damage to the compressor that may occur during the removal of foreign matter adsorbed on the indoor heat exchanger.

[0019] In addition, according to at least one embodiment of the present invention, the action of removing foreign matter adsorbed on the indoor heat exchanger can be repeated by considering whether the foreign matter adsorbed on the indoor heat exchanger is sufficiently removed according to the purpose, thereby more effectively removing foreign matter adsorbed on the indoor heat exchanger.

[0020] The applicable additional scope of the present invention should be clear from the following detailed description. However, it should be understood that those skilled in the art can clearly understand various changes and modifications within the concept and scope of the present invention, and the detailed description and specific embodiments such as the preferred embodiments of the present invention are provided only as examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing an example of the configuration of an air conditioner according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of an outdoor unit and an indoor unit according to an embodiment of the present invention.

[0023] Figure 3 FIG. 1 is a block diagram of an air conditioner according to an embodiment of the present invention.

[0024] Figures 4 to 6 This is a flowchart showing an operating method of an air conditioner according to various embodiments of the present invention.

[0025] Figures 7 to 9 These are diagrams referred to for explaining the operation of the air conditioner according to various embodiments of the present invention. DETAILED DESCRIPTION

[0026] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, parts not relevant to the description are omitted for clarity and simplicity. Throughout the specification, the same or very similar parts are denoted by the same reference numerals.

[0027] The suffixes "module" and "unit" used in the following description of the components are only given for the convenience of writing the description and do not have different meanings or functions. Therefore, the "module" and "unit" can be used interchangeably.

[0028] In this specification, the terms "including" or "having" should be understood as referring to the existence of the features, numbers, steps, actions, structural elements, parts or their combinations disclosed in this specification, and are not intended to preclude the existence or additional possibilities of one or more other features, numbers, steps, actions, structural elements, parts or their combinations.

[0029] In addition, in this specification, in order to describe various elements, terms such as first and second may be used, but such elements are not limited to such terms. Such terms are only used to distinguish one element from another.

[0030] Figure 1 This is a diagram showing an example of the configuration of an air conditioner according to an embodiment of the present invention.

[0031] Reference Figure 1 The air conditioner 100 according to an embodiment of the present invention may include an outdoor unit 21 and an indoor unit 31 connected to the outdoor unit 21. In the present invention, the indoor unit 31 is described as a wall-mounted air conditioner, but the invention is not limited thereto.

[0032] On the other hand, the air conditioner 100 may further include at least one of a ventilation device, an air purification device, a humidification device, and a heater, and may operate in conjunction with the operations of the indoor unit 31 and the outdoor unit 21 .

[0033] The outdoor unit 21 may include a compressor (not shown) that receives and compresses refrigerant, an outdoor heat exchanger (not shown) that exchanges heat between the refrigerant and outdoor air, an accumulator (not shown) that extracts gaseous refrigerant from the supplied refrigerant and supplies it to the compressor, a four-way valve (not shown) that selects the refrigerant flow path according to heating operation, and an expansion valve (not shown) that expands the supplied refrigerant. The outdoor unit 21 may also include a plurality of sensors, valves, an oil collector, and the like.

[0034] The outdoor unit 21 operates its included compressor and outdoor heat exchanger according to settings to compress refrigerant or perform heat exchange, and then supplies the refrigerant to the indoor unit 31. The outdoor unit 21 can be driven by a remote controller (not shown) or based on demand from the indoor unit 31. In this case, the cooling / heating capacity changes depending on the indoor unit 31 being driven, and the number of outdoor units in operation and the number of compressors installed in the outdoor units also change.

[0035] At this time, the outdoor unit 21 may supply compressed refrigerant to the connected indoor unit 31 .

[0036] The indoor unit 31 receives refrigerant from the outdoor unit 21 and discharges cold or hot air into the room.

[0037] The indoor unit 31 may include an indoor heat exchanger (not shown), an indoor fan (not shown), a plurality of sensors (not shown), and the like.

[0038] The indoor unit 31 may include a drain pan (not shown) disposed adjacent to the indoor heat exchanger to collect water generated by heat exchange in the indoor heat exchanger and a drain pipe (not shown) to discharge the water collected in the drain pan to the outside.

[0039] The outdoor unit 21 and the indoor unit 31 can communicate with each other. For example, the outdoor unit 21 and the indoor unit 31 can be connected using a communication line to transmit and receive data between them. The outdoor unit 21 and the indoor unit 31 can also be connected to a remote controller (not shown) via a wired or wireless connection and operate according to the control of the remote controller (not shown).

[0040] The remote controller 41 can be connected to the indoor unit 31 and transmit the user's control instructions to the indoor unit 31. The remote controller 41 can receive and display status information of the indoor unit 31. At this time, the remote controller 41 can communicate in a wired or wireless manner depending on the connection method with the indoor unit 31.

[0041] Figure 2 This is a schematic diagram of an outdoor unit and an indoor unit according to an embodiment of the present invention. Figure 1 A detailed description of the content that is repeated in the description.

[0042] Reference Figure 2 The outdoor unit 21 may include a compressor 102 that compresses the refrigerant, a compressor motor 102b that drives the compressor 102, an outdoor heat exchanger 104 that dissipates heat from the compressed refrigerant, an outdoor blower 105 composed of an outdoor fan 105a that is arranged on one side of the outdoor heat exchanger 104 and promotes heat dissipation of the refrigerant and a motor 105b that rotates the outdoor fan 105a, an expansion valve 106 that expands the condensed refrigerant, a cooling / heating switching valve 110 that changes the flow path of the compressed refrigerant, and a liquid accumulator 103 that temporarily stores the vaporized refrigerant and supplies the refrigerant of a specified pressure to the compressor after removing moisture and foreign matter.

[0043] The compressor 102 may be, for example, at least one of an inverter compressor and a fixed-frequency compressor.

[0044] The expansion valve 106 may be, for example, an electronic expansion valve (EEV).

[0045] The indoor unit 31 may include an indoor heat exchanger 108 arranged indoors to perform cooling / heating functions, and an indoor blower 109 formed by an indoor fan 109a arranged on one side of the indoor heat exchanger 108 to promote heat dissipation of the refrigerant and a motor 109b to rotate the indoor fan 109a.

[0046] The air conditioner 100 may include at least one indoor unit 31. In the case where the air conditioner 100 includes a plurality of indoor units 31, a plurality of indoor heat exchangers 108 may be connected to the outdoor units 21, respectively.

[0047] The air conditioner 100 may be a refrigerator that cools a room, or a heat pump that cools or heats a room.

[0048] Figure 3 FIG. 1 is a block diagram of an air conditioner according to an embodiment of the present invention.

[0049] Reference Figure 3 The air conditioner 100 may include a communication interface 310 , a sensor unit 320 , a memory 330 , a fan driving unit 340 driving a fan 341 , a compressor driving unit 350 driving the compressor 102 , and / or a control unit 370 .

[0050] The communication interface 310 may include at least one communication module. For example, the communication interface 310 may be provided in the outdoor unit 21 and the indoor unit 31 respectively, and the outdoor unit 21 and the indoor unit 31 may transmit and receive data with each other.

[0051] The communication method between the outdoor unit 21 and the indoor unit 31 can be not only a communication method using electric wires, a serial communication method (for example, RS-485 communication), and a wired communication method through refrigerant piping, but also a wireless communication method such as Wireless Fidelity (Wi-Fi), Bluetooth, Beacon, Zigbee, etc.

[0052] The communication interface 310 can transmit and receive data between external devices and each other. For example, the communication interface 310 can be connected to a server on an external network to transmit and receive data.

[0053] The sensor unit 320 may include at least one sensor and may transmit data of a detection value detected by the sensor to the control unit 370 .

[0054] The sensor unit 320 may include a heat exchanger temperature sensor 321. The heat exchanger temperature sensor 321 may be located inside or outside the indoor heat exchanger 108 to detect the temperature of the indoor heat exchanger 108. For example, if the heat exchanger temperature sensor 321 is located outside the indoor heat exchanger 108, it may be located outside the heat exchanger or on a pipe. In this case, the heat exchanger temperature sensor 321 may detect the temperature of the indoor heat exchanger 108 by measuring the surface temperature of the heat exchanger or the ambient temperature of the heat exchanger.

[0055] The sensor unit 320 may include a pipe temperature sensor 323. The pipe temperature sensor 323 may detect the temperature of the refrigerant flowing through each pipe of the air conditioner 100. For example, the pipe temperature sensor 323 may be disposed on the inlet-side pipe of the indoor unit 31 and / or the outlet-side pipe of the indoor unit 31. For example, the pipe temperature sensor 323 may be disposed on the pipe connected to the compressor 102 and may detect the temperature of the refrigerant flowing into the compressor 102 (hereinafter referred to as the suction temperature) and / or the temperature of the refrigerant discharged from the compressor 102 (hereinafter referred to as the discharge temperature).

[0056] The sensor unit 320 may include an indoor temperature sensor 325 for detecting indoor temperature and / or an outdoor temperature sensor 327 for detecting outdoor temperature.

[0057] The sensor unit 320 may include a pressure sensor (not shown). The pressure sensor (not shown) can detect the pressure of the gas refrigerant flowing through each pipe of the air conditioner 100. For example, the pressure sensor can be disposed in a pipe connected to the compressor 102 and can detect the pressure of the refrigerant flowing into the compressor 102 (hereinafter referred to as the suction pressure) and / or the pressure of the refrigerant discharged from the compressor 102 (hereinafter referred to as the discharge pressure).

[0058] The memory 330 may store data of reference values ​​related to the operation of each component provided in the air conditioner 100 .

[0059] The memory 330 can store programs for processing and controlling various signals within the control unit 370, and can also store data to be processed and data to be processed. For example, the memory 330 can store a plurality of application programs designed to execute various tasks that can be processed by the control unit 370. When requested by the control unit 370, the memory 330 can selectively provide some of the stored application programs.

[0060] The memory 330 may include, for example, at least one of a volatile memory (eg, DRAM, SRAM, SDRAM, etc.) or a non-volatile memory (eg, flash memory, hard disk drive (HDD), solid-state drive (SSD), etc.).

[0061] The fan driving unit 340 may drive a fan 341 provided in the air conditioner 100. For example, the fan 341 may include an outdoor fan 105a and / or an indoor fan 109a.

[0062] The fan drive unit 340 may include a rectifier (not shown), a DC terminal capacitor (not shown), an inverter (not shown) and / or a motor, wherein the rectifier rectifies the AC power supply into a DC power supply and outputs it, the DC terminal capacitor stores the pulsating voltage from the rectifier, the inverter is provided with a plurality of switching devices so as to convert the smooth DC power supply into a three-phase AC power supply of a specified frequency and output it, and the motor drives the fan 341 according to the three-phase AC power supply output from the inverter.

[0063] On the other hand, the fan driving unit 340 may be separately provided for driving the outdoor fan 105a and the indoor fan 109a. For example, the air conditioner 100 may include a first fan driving unit for driving the outdoor fan 105a and a second fan driving unit for driving the indoor fan 109a.

[0064] The compressor driver 350 can drive the compressor 102. The compressor driver 350 may include a rectifier (not shown) that rectifies AC power into DC power and outputs it, a DC-terminal capacitor (not shown) that stores a pulsating voltage from the rectifier, an inverter (not shown) provided with a plurality of switching devices that converts the smoothed DC power into three-phase AC power of a predetermined frequency and outputs it, and / or a compressor motor 102b that drives the compressor 102 based on the three-phase AC power output from the inverter.

[0065] The blade 360 ​​can be arranged at the outlet of the indoor unit 31, and the outlet discharges the air flowing through the indoor fan 109a. The air conditioner 100 may further include a vane motor that drives the blade 360 ​​and a connecting rod connecting the blade 360 ​​and the vane motor. For example, when the connecting rod rotates as the vane motor rotates, the direction in which the blade 360 ​​is facing can change as the connecting rod rotates. At this time, as the direction in which the blade 360 ​​is facing changes, the direction in which the air is discharged through the outlet of the indoor unit 31 (hereinafter referred to as the wind direction) can be changed. The vane motor can be implemented by a stepper motor, but is not limited to this.

[0066] The control unit 370 can control the overall operation of the air conditioner 100. The control unit 370 can be connected to each component provided in the air conditioner 100, and can control the overall operation of each component by transmitting and / or receiving signals between the components.

[0067] The control unit 370 can change the rotational speed of the fan 341 by controlling the operation of the fan driver 340. For example, the fan driver 340 can change the rotational speed of the outdoor fan 105a by changing the frequency of the three-phase AC power supplied to the outdoor fan motor 105b under the control of the control unit 370. For example, the fan driver 340 can change the rotational speed of the indoor fan 109a by changing the frequency of the three-phase AC power supplied to the indoor fan motor 109b under the control of the control unit 370.

[0068] The controller 370 can change the operating frequency of the compressor 102 by controlling the operation of the compressor driver 350. For example, the compressor driver 350 can change the operating frequency of the compressor 102 by changing the frequency of the three-phase AC power output to the compressor motor 102b under the control of the controller 370.

[0069] The control unit 370 can change the wind direction. For example, when changing the wind direction, the control unit 370 can rotate the blade motor to change the direction in which the blades 360 face.

[0070] The control unit 370 may be provided not only in the outdoor unit 21 but also in a central controller (not shown) that controls the operations of the indoor unit 31 , the outdoor unit 21 , and / or the indoor unit 31 .

[0071] The control unit 370 may include at least one processor and may utilize the processor to control the overall operation of the air conditioner 100. The processor may be a general-purpose processor such as a CPU (central processing unit). Alternatively, the processor may be a dedicated device such as an ASIC or a processor based on other hardware.

[0072] The control unit 370 may acquire data related to each component provided in the air conditioner 100. In this case, the control unit 370 may acquire data related to each component provided in the air conditioner 100 at predetermined time intervals according to a predetermined cycle, taking into account the computational load.

[0073] The control unit 370 can perform various calculations based on the acquired data, and can control the overall operation of each component provided in the air conditioner 100 according to the calculation results.

[0074] The data related to each component installed in the air conditioner 100 may include, for example, the operating frequency of the compressor 102, the suction temperature, discharge temperature, suction pressure, discharge pressure of the compressor 102, the inlet side piping temperature of the indoor unit 31, the outlet side piping temperature of the indoor unit 31, the indoor temperature, the outdoor temperature, the opening amount of the electronic expansion valve (EEV), etc.

[0075] On the other hand, the air conditioner 100 may further include an input device (not shown) capable of receiving user input. For example, when receiving user input via an input device (e.g., a touch panel, a keypad, etc.), the air conditioner 100 may perform an action corresponding to the received user input.

[0076] The air conditioner 100 may further include an output device (not shown) that outputs information about the operating status of the air conditioner 100. For example, the output device may include a display device such as a display or a light emitting diode (LED) and / or an audio device such as a speaker or a buzzer.

[0077] Figures 4 to 6 This is a flowchart showing an operating method of an air conditioner according to various embodiments of the present invention.

[0078] Reference Figure 4 In step S410, the air conditioner 100 may determine whether the temperature condition for activating the function of removing foreign matter present on the surface of the indoor heat exchanger 108 (hereinafter referred to as the foreign matter removal function) is met. For example, the air conditioner 100 may determine the temperature condition for activating the foreign matter removal function based on user input for activating the foreign matter removal function received via the touch panel of the remote controller 41. For example, regarding the execution of the foreign matter removal function, the air conditioner 100 may determine the temperature condition for activating the foreign matter removal function based on a pre-set period.

[0079] The temperature condition for activating the foreign object removal function can correspond to whether the indoor and outdoor temperatures are respectively within a specified temperature range. For example, if the indoor temperature corresponds to a first temperature range above zero and the outdoor temperature corresponds to a second temperature range above zero, the air conditioner 100 can determine that the temperature condition for activating the foreign object removal function is met. Here, the first and second temperature ranges can be temperature ranges that ensure the specified cooling performance when the air conditioner 100 is operating as a refrigerator. For example, the first temperature range can be 21°C to 32°C, and the second temperature range can be 21°C to 37°C.

[0080] In step S420, if the temperature conditions for activating the foreign object removal function are not met, the air conditioner 100 may notify the user that foreign object removal cannot be activated. For example, the air conditioner 100 may output an indicator indicating that the foreign object removal function cannot be activated via the display of the remote controller 41. Alternatively, if the temperature conditions for activating the foreign object removal function are not met, the air conditioner 100 may continue the currently executing action.

[0081] In step S430, if the temperature conditions for activating the foreign matter removal function are met, the air conditioner 100 may perform an operation related to condensing moisture contained in the indoor air (hereinafter referred to as the condensation operation). Here, the condensation operation may refer to the air conditioner 100 causing moisture contained in the indoor air to condense into water droplets on the surface of the indoor heat exchanger 108. For example, as a case of performing the condensation operation, the air conditioner 100 may perform the condensation operation for a predetermined time (hereinafter referred to as the condensation time).

[0082] When it is determined that the condensing operation is to be performed, the air conditioner 100 can confirm whether the compressor 102 is driven. At this time, when the compressor 102 is not driven, the air conditioner 100 can start the compressor 102 by controlling the compressor driving unit 350. For example, when the compressor 102 is started, the air conditioner 100 can control the operation of each component according to a preset condition so that the operating frequency of the compressor 102 reaches a specified frequency. The air conditioner 100 can control the operation of each component according to a cooling mode for cooling the room. For example, when the compressor 102 is started, the air conditioner 100 can open the electronic expansion valve (EEV) according to a preset opening amount. On the other hand, when the compressor 102 can fully compress the inflowing refrigerant into a high-temperature, high-pressure gas refrigerant according to the purpose, the air conditioner 100 can determine that the refrigerant cycle has stabilized.

[0083] The air conditioner 100 can determine a target temperature for the indoor heat exchanger 108 related to condensation (hereinafter referred to as the condensation target temperature). The condensation target temperature can be a temperature at which moisture contained in the indoor air condenses into water droplets on the surface of the indoor heat exchanger 108 without the water droplets freezing. The condensation target temperature can correspond to the indoor temperature. For example, the condensation target temperature can be a temperature that is lower than the current indoor temperature by a predetermined temperature related to condensation (e.g., 18°C). The present invention is described based on the temperature of the indoor heat exchanger 108, but is not limited to this. For example, the air conditioner 100 can perform an operation based on the lower temperature of the inlet and outlet pipes of the indoor heat exchanger 108. For example, the air conditioner 100 can perform an operation based on the intermediate value between the inlet and outlet pipe temperatures of the indoor heat exchanger 108.

[0084] The air conditioner 100 may adjust the operating frequency of the compressor 102 based on the current temperature of the indoor heat exchanger 108 and the target condensation temperature. For example, the air conditioner 100 may adjust the operating frequency of the compressor 102 according to the difference between the current temperature of the indoor heat exchanger 108 and the target condensation temperature. In this case, the greater the difference between the current temperature of the indoor heat exchanger 108 and the target condensation temperature, the higher the operating frequency of the compressor 102.

[0085] According to one embodiment, the air conditioner 100 may change the specified temperature associated with determining the target condensation temperature. The air conditioner 100 may receive temperature and humidity data corresponding to a specified location and a specified date and time from a server connected to the network via the communication interface 310. The specified location may correspond to a location where the air conditioner 100 is installed. The specified date and time may correspond to the time, date, and / or duration corresponding to the activation of the foreign matter removal function.

[0086] The air conditioner 100 may determine the prescribed temperature based on temperature and humidity data. The temperature and humidity data may include dry-bulb temperature, relative humidity, and / or dew point temperature. For example, if the temperature and humidity data include dry-bulb temperature and relative humidity, the air conditioner 100 may determine the dew point temperature corresponding to the dry-bulb temperature and relative humidity based on a psychrometric chart.

[0087] The air conditioner 100 may set a predetermined temperature based on the difference between the indoor temperature and the dew point temperature. Figure 7Based on the temperature and humidity data, the dew point temperature 700 corresponding to the indoor temperature can be determined. In this case, the air conditioner 100 can determine the prescribed temperature to be a temperature that is a predetermined level higher than the minimum value of the difference between the indoor temperature and the dew point temperature. For example, if the indoor temperature is 32°C and the dew point temperature is 16.7°C, the difference between the indoor temperature and the dew point temperature can be the minimum value. In this case, the air conditioner 100 can determine the prescribed temperature to be 17°C, which is at least 1°C higher and less than 2°C higher than the difference between the indoor temperature and the dew point temperature of 15.3°C.

[0088] Alternatively, the air conditioner 100 can determine whether to execute the foreign object removal function based on data received from the server. For example, the air conditioner 100 can confirm the dry-bulb temperature, relative humidity, dew point temperature, etc. at a specific date and time based on the data received from the server. In this case, if the condensation level is determined to be above a predetermined threshold based on the dry-bulb temperature, relative humidity, dew point temperature, etc. at the specific date and time, the air conditioner 100 can determine to execute the foreign object removal function. For example, the air conditioner 100 can determine to execute the foreign object removal function based on the difference between the indoor temperature and the dew point temperature being less than a predetermined threshold.

[0089] The air conditioner 100 may output a message advising the execution of the foreign object removal function via an output device. For example, the air conditioner 100 may output a message advising the execution of the foreign object removal function via the display of the remote controller 41 when the difference between the indoor temperature and the dew point temperature is less than a first reference value (e.g., 10°C). Alternatively, the air conditioner 100 may output a message advising the execution of the foreign object removal function via the display of the remote controller 41 when the difference between the indoor temperature and the dew point temperature is greater than a second reference value (e.g., 18°C).

[0090] During the condensing operation, the air conditioner 100 can control the blades 360 so that air is discharged along a predetermined wind direction for the condensing operation. For example, the wind direction may include an indirect airflow (forming an airflow in the direction of the front of the air conditioner 100), a direct airflow (forming an airflow in the direction of the lower end of the air conditioner 100), and an inclined airflow corresponding to the indirect and direct airflows. The air conditioner 100 can increase the angle of the blades 360 to form the indirect airflow. Here, the angle of the blades 360 can be an angle formed by the blades 360 and a predetermined direction perpendicular to the ground. For example, when the angle of the blades 360 is at its maximum value, an indirect airflow can be formed. Alternatively, the air conditioner 100 can decrease the angle of the blades 360 to form a direct airflow. For example, when the angle of the blades 360 is at its minimum value, a direct airflow can be formed. In this case, during the condensing operation, the air conditioner 100 can control the blades 360 so that air is discharged along the inclined airflow.

[0091] During the condensing operation, the air conditioner 100 can rotate the indoor fan 109a at a preset rotational speed corresponding to the condensing operation. For example, during the condensing operation, the air conditioner 100 can rotate the indoor fan 109a at a rotational speed corresponding to the second level of the four preset rotational speed levels. Here, as the rotational speed level increases, the rotational speed increases, thereby increasing the air volume (the flow rate of air flowing through the indoor fan 109a). While the present invention is described with the rotational speed divided into four levels, this is not limiting.

[0092] According to one embodiment, the air conditioner 100 can determine whether to execute a condensing operation. For example, the air conditioner 100 can be pre-configured to execute a condensing operation when performing an action for removing foreign matter. For example, the air conditioner 100 can determine whether to execute a condensing operation based on user input received via a touch panel configured on the remote controller 41. In this case, if there is a history of user input related to previously executed condensing operations, the air conditioner 100 can also determine whether to execute a condensing operation based on the history.

[0093] In the case where the condensation operation is completed in S440, the air conditioner 100 may perform an operation related to freezing of water (hereinafter referred to as freezing operation). Here, the freezing operation may refer to an operation of the air conditioner 100 to form ice on the surface of the indoor heat exchanger 108. Figure 5 , specify the freeze action.

[0094] Reference Figure 5 In step S510, the air conditioner 100 may check whether the opening of the expansion valve 106 is less than a preset opening related to starting the freezing operation (hereinafter referred to as the freezing opening). Here, the freezing opening may be less than the opening of the expansion valve 106 when the compressor 102 is completely started (hereinafter referred to as the starting opening).

[0095] In operation S520 , the air conditioner 100 may change the opening degree of the expansion valve 106 to the freezing opening degree based on the fact that the opening degree of the expansion valve 106 exceeds the freezing opening degree.

[0096] In operation S530, the air conditioner 100 may control the compressor 102 based on a target temperature (hereinafter referred to as a freezing target temperature) for the temperature of the indoor heat exchanger 108 related to freezing. The freezing target temperature may be determined within a sub-zero temperature range below 0°C. For example, the freezing target temperature may be pre-set to a predetermined temperature (e.g., -19°C) at which the water condensed in the indoor heat exchanger 108 is sufficiently frozen to a predetermined level or higher.

[0097] The air conditioner 100 may control the operating frequency of the compressor 102 based on the difference between the current temperature of the indoor heat exchanger 108 and the freezing target temperature. For example, if the current temperature of the indoor heat exchanger 108 is higher than the freezing target temperature, the air conditioner 100 may control the compressor driver 350 to increase the operating frequency of the compressor 102.

[0098] In step S540 , the air conditioner 100 determines whether the current temperature of the indoor heat exchanger 108 is less than a preset limit temperature. The limit temperature may be preset to a temperature higher than the target freezing temperature. For example, the limit temperature may be preset to -10°C, which is a sub-zero temperature higher than the target freezing temperature of -19°C.

[0099] In step S550, the air conditioner 100 can adjust the compressor 102's operating frequency to a predetermined maximum frequency based on the current temperature of the indoor heat exchanger 108 being lower than a predetermined limit temperature. For example, when the current temperature of the indoor heat exchanger 108 is above the limit temperature of -10°C, the maximum operating frequency of the compressor 102 can be preset to a first frequency (e.g., 90 Hz). In this case, the air conditioner 100 can change the maximum operating frequency of the compressor 102 to a second frequency (e.g., 75 Hz) that is lower than the first frequency by a predetermined frequency (e.g., 15 Hz) based on the current temperature of the indoor heat exchanger 108 being lower than the limit temperature of -10°C. This prevents the temperature of the indoor heat exchanger 108 from dropping excessively. Furthermore, by preventing the compressor 102 from stopping due to an increase in its compression ratio, the freezing operation is performed, ensuring that the water condensed in the indoor heat exchanger 108 is fully frozen.

[0100] In step S560, the air conditioner 100 may determine whether a minimum time associated with executing the freezing operation (hereinafter referred to as the minimum freezing time) has elapsed since the freezing operation began. The minimum freezing time may be a time greater than the condensing time for executing the condensing operation. For example, the condensing time may be preset to 5 minutes, and the minimum freezing time may be preset to 10 minutes.

[0101] In step S570, the air conditioner 100 may determine whether the temperature of the indoor heat exchanger 108 is below the freezing target temperature based on the expiration of the minimum freezing time. According to one embodiment, the air conditioner 100 may determine that the temperature of the indoor heat exchanger 108 is below the freezing target temperature if the temperature of the indoor heat exchanger 108 remains below the freezing target temperature for a predetermined time (e.g., 10 seconds) or longer.

[0102] In step S580, the air conditioner 100 may determine whether the maximum time for executing the freezing operation (hereinafter referred to as the maximum freezing time) has elapsed based on the fact that the temperature of the indoor heat exchanger 108 is higher than the freezing target temperature. For example, the maximum freezing time may be preset to 15 minutes.

[0103] If the temperature of the indoor heat exchanger 108 corresponds to at least one of a case where the temperature is lower than the freezing target temperature and a case where the maximum freezing time has passed after the minimum freezing time has passed, the air conditioner 100 may end the freezing operation.

[0104] On the other hand, during the freezing operation, the air conditioner 100 can control the vanes 360 so that air is discharged through the outlet of the indoor unit 31 in a direction different from the pre-set air direction for the condensing operation. For example, during the freezing operation, the air conditioner 100 can control the vanes 360 so that air is discharged along the indirect airflow. For example, during the freezing operation, the air conditioner 100 can control the vanes 360 to close the outlet of the indoor unit 31.

[0105] During the freezing operation, the air conditioner 100 may set the rotation speed of the outdoor fan 105a to the maximum rotation speed. During the freezing operation, the air conditioner 100 may adjust the rotation speed of the indoor fan 109a. For example, when the freezing operation is activated, the air conditioner 100 may rotate the indoor fan 109a at a rotation speed corresponding to the first level among four pre-set rotation speed levels.

[0106] In this case, if the inlet pipe temperature of the indoor unit 31 is above a preset upper limit temperature after a predetermined time (e.g., 12 minutes) has passed since the freezing operation was initiated, the air conditioner 100 can control the fan driver 340 to reduce the rotational speed of the indoor fan 109a to a value lower than the current rotational speed. The preset upper limit temperature can be the highest temperature within the temperature range where condensed water in the indoor heat exchanger 108 can freeze (e.g., -5°C). Meanwhile, during the freezing operation, the air conditioner 100 can monitor the inlet pipe temperature of the indoor unit 31 at a predetermined interval (e.g., 100 seconds). If the difference between the inlet pipe temperatures of the indoor unit 31 detected at the predetermined interval is lower than a predetermined difference (e.g., 0.2°C), the fan driver 340 can be controlled to reduce the rotational speed of the indoor fan 109a to a value lower than the current rotational speed. While the present invention describes adjusting the rotational speed of the indoor fan 109a based on the inlet pipe temperature of the indoor unit 31, the present invention is not limited thereto.

[0107] Refer again Figure 4In step S450, if the freezing operation is complete, the air conditioner 100 may perform a defrosting operation to melt ice formed on the surface of the indoor heat exchanger 108. When performing the defrosting operation, the air conditioner 100 may perform the defrosting operation during a predetermined time (hereinafter referred to as the defrosting time). For example, the defrosting time may be shorter than the freezing time and the minimum freezing time.

[0108] While the defrosting operation is being performed, the air conditioner 100 may rotate the indoor fan 109a at a rotation speed corresponding to the first level or the second level among four levels of rotation speeds that are set in advance.

[0109] During the thawing operation, the air conditioner 100 may set the operating frequency of the compressor 102 to a predetermined minimum frequency. Here, the minimum frequency may correspond to the minimum value of the operating frequency that can be reduced while the compressor 102 is driven. During the thawing operation, the air conditioner 100 may set the opening of the expansion valve 106 to a predetermined minimum opening. For example, the minimum opening may be a startup opening or a freeze-opening opening. For example, the minimum opening may be an opening that is smaller than the startup opening and the freeze-opening opening. During the thawing operation, the air conditioner 100 may set the rotational speed of the outdoor fan 105a to the minimum rotational speed.

[0110] Since the operating frequency of the compressor 102, the opening degree of the expansion valve 106, the rotation speed of the outdoor fan 105a, etc. are set to minimum values, during the defrosting operation, the refrigerant remaining in the indoor unit 31, the piping connecting the outdoor unit 21 and the indoor unit 31, etc. can be recovered to the outdoor unit 102 to the maximum extent. This can prevent the damage to the compressor 102 and the reduction in efficiency caused by the inflow of liquid refrigerant into the compressor 102.

[0111] On the other hand, when the defrosting time has elapsed, the air conditioner 100 may stop the operation of the outdoor unit 21. For example, the air conditioner 100 may stop driving the compressor 102. For example, the air conditioner 100 may stop rotating the outdoor fan 105a.

[0112] In the case of defrosting time in S460, the air conditioner 100 can perform an operation (hereinafter referred to as drying operation) to remove condensed, frozen, and thawed moisture in the indoor heat exchanger 108. The air conditioner 100 can perform either a complete drying operation to remove all moisture from the indoor heat exchanger 108 or a partial drying operation to remove part of the moisture from the indoor heat exchanger 108. Figure 6 , specifically explain the drying action.

[0113] Reference Figure 6In step S610, the air conditioner 100 may determine whether to repeatedly perform the foreign matter removal operation. For example, the air conditioner 100 may determine whether the condensing operation, the freezing operation, and the defrosting operation are performed more than twice.

[0114] In operation S620 , when the operation for removing foreign matter is not repeatedly performed, the air conditioner 100 may check whether the temperature of the indoor heat exchanger 108 has reached the freezing target temperature during the freezing operation.

[0115] In step S630, if the temperature of the indoor heat exchanger 108 is higher than the freezing target temperature and the freezing operation has ended, the air conditioner 100 may confirm whether the freezing operation has ended when the temperature of the indoor heat exchanger 108 is lower than a predetermined reference temperature that is higher than the freezing target temperature. For example, if the freezing target temperature is -19°C, the reference temperature may be pre-set to -17°C, which is higher than -19°C.

[0116] In operation S640 , when the temperature of the indoor heat exchanger 108 is equal to or higher than the reference temperature and the freezing operation is completed, the air conditioner 100 may perform a partial drying operation.

[0117] According to one embodiment, when performing a partial drying operation, the air conditioner 100 may rotate the indoor fan 109a at a speed corresponding to the third level of four pre-set rotational speeds during a predetermined first time period. In this case, the air conditioner 100 may control the blades 360 to discharge air in a predetermined direction for the partial drying operation. For example, during the partial drying operation, the air conditioner 100 may control the blades 360 to discharge air in an indirect airflow.

[0118] In operation S650 , the air conditioner 100 may determine to repeatedly perform an operation for removing foreign matter.

[0119] In operation S660 , when the temperature of the indoor heat exchanger 108 is lower than the reference temperature and the freezing operation is completed, the air conditioner 100 may perform the complete drying operation.

[0120] According to one embodiment, when performing a full drying operation, the air conditioner 100 may rotate the indoor fan 109a at a speed corresponding to the fourth of four pre-set speed levels during a second time period that is longer than the first time period. In this case, the air conditioner 100 may change the direction of the blades 360 so that the wind direction continuously changes during the second time period. For example, the air conditioner 100 may drive the vane motor so that the wind direction continuously changes between direct airflow and indirect airflow during the second time period. For example, the air conditioner 100 may control the direction of the blades 360 to change in the left-right direction. This allows moisture to be evenly dried throughout the indoor heat exchanger 108.

[0121] On the other hand, after the second time has elapsed, the air conditioner 100 may rotate the indoor fan 109a at a speed corresponding to the second level among the four preset speed levels during a third time period that is shorter than the second time period. In this case, during the third time period, the air conditioner 100 may control the blades 360 so that air is discharged along an inclined airflow.

[0122] In operation S660 , the air conditioner 100 may determine to end the operation for removing foreign matter.

[0123] Refer again Figure 4 In step S470, the air conditioner 100 may confirm whether the foreign matter removal operation is completed. If the foreign matter removal operation is repeated, the air conditioner 100 may perform the condensing operation, the freezing operation, and / or the drying operation again.

[0124] Figure 8 is a graph showing the temperature of the indoor heat exchanger 108. Figure 8 The air conditioner 100 may perform the condensing operation until time point t1, perform the freezing operation from time point t1 to time point t2, perform the defrosting operation from time point t2 to time point t3, and perform the drying operation starting from time point t3.

[0125] When the indoor temperature T0 is within the first temperature range of 21°C to 32°C, the temperature of the indoor heat exchanger 108 may correspond to the indoor temperature T0. In this case, while the air conditioner 100 is performing the condensing operation, the temperature of the indoor heat exchanger 108 may be lowered to a temperature T1 below the dew point. While the air conditioner 100 is performing the freezing operation, the temperature of the indoor heat exchanger 108 may be gradually lowered. In this case, the freezing operation may be terminated when the temperature of the indoor heat exchanger 108 reaches the freezing target temperature T2. On the other hand, while the air conditioner 100 is performing the defrosting operation and the drying operation, the temperature of the indoor heat exchanger 108 may be gradually increased.

[0126] Figure 9is a graph showing the rotation speed of the indoor fan 109a. Figure 9 During the condensing operation, the air conditioner 100 can rotate the indoor fan 109a at a rotation speed corresponding to the second level f2 of the four preset rotation speed levels. During the freezing operation, the air conditioner 100 can rotate the indoor fan 109a at a rotation speed corresponding to the first level f1 slower than the rotation speed f2 during the condensing operation. During the defrosting operation, the air conditioner 100 can rotate the indoor fan 109a at a rotation speed corresponding to the second level f2 faster than the rotation speed f1 during the freezing operation.

[0127] From time t3 to time t4 when performing the complete drying operation, the air conditioner 100 may rotate the indoor fan 109a at a rotation speed corresponding to the fourth level f4, which is the highest rotation speed. On the other hand, starting from time t4 when performing the complete drying operation, the air conditioner 100 may again rotate the indoor fan 109a at a rotation speed corresponding to the second level f2.

[0128] As described above, according to at least one of the embodiments of the present invention, foreign matter adsorbed on the indoor heat exchanger 108 can be effectively removed simply by detecting the temperature.

[0129] In addition, according to at least one embodiment of the present invention, it is possible to prevent damage to the compressor 102 that may occur during the removal of foreign matter adsorbed on the indoor heat exchanger 108 .

[0130] In addition, according to at least one embodiment of the present invention, the action of removing foreign matter adsorbed on the indoor heat exchanger 108 can be repeated by considering whether the foreign matter adsorbed on the indoor heat exchanger 108 is sufficiently removed according to the purpose, thereby more effectively removing foreign matter adsorbed on the indoor heat exchanger 108.

[0131] It should be understood that the drawings are only used to easily understand the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited to the drawings, and include all changes, equivalents or substitutes within the ideas and technical scope of the present invention.

[0132] Likewise, although multiple actions are depicted in a particular order in the drawings, this should not be understood as requiring that these actions be performed in the particular order shown or in sequential order, or that all of the actions shown be performed, in order to achieve preferred results. In certain circumstances, multitasking and parallel processing may be more advantageous.

[0133] In addition, although the preferred embodiments of the present invention are illustrated and described above, the present invention is not limited to the specific embodiments described above, and various modifications can be implemented by ordinary technicians in the technical field to which the corresponding invention belongs without departing from the gist of the invention required in the scope of the claims, and such modified implementation should not be understood solely from the technical ideas or prospects of the present invention.

Claims

1. An air conditioner, characterized in that: include: Compressor, compresses and discharges refrigerant; An indoor heat exchanger for exchanging heat between the refrigerant and indoor air; a sensor unit for sensing the temperature of the indoor heat exchanger and the indoor temperature; as well as Control Department; The control unit performs primary control on the compressor based on a first target temperature of the indoor heat exchanger corresponding to the indoor temperature. If the first control is completed, the control unit performs a second control on the compressor based on a second target temperature of the indoor heat exchanger that is below zero and lower than the first target temperature. When the second control is completed, the control unit sets the operating frequency of the compressor to a preset minimum frequency during a predetermined time period. If the predetermined time has elapsed, the control unit determines whether to repeat the first control based on a condition related to the second control.

2. The air conditioner according to claim 1, wherein Also includes: an expansion valve, expanding the refrigerant flowing to the indoor heat exchanger; An outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air; as well as an outdoor fan, disposed adjacent to the outdoor heat exchanger; The control unit sets the opening of the expansion valve to a preset minimum opening during the predetermined time. The control unit sets the rotation speed of the outdoor fan to a preset minimum rotation speed during the predetermined time.

3. The air conditioner according to claim 1, wherein If the second control ends while the temperature of the indoor heat exchanger is lower than a predetermined reference temperature higher than the second target temperature, the control unit determines not to repeat the first control. If the second control is completed in a state where the temperature of the indoor heat exchanger is equal to or higher than the reference temperature, the control unit determines to repeat the first control.

4. The air conditioner according to claim 3, wherein During the execution of the second control, The control unit checks whether the temperature of the indoor heat exchanger is lower than the second target temperature based on the fact that the second control has been executed for a predetermined minimum time or longer. The control unit checks whether the second control has been executed for a predetermined maximum time or longer based on the fact that the temperature of the indoor heat exchanger is higher than the second target temperature. The control unit ends the second control based on at least one of a case where the temperature of the indoor heat exchanger is lower than or equal to the second target temperature and a case where the second control has been executed for a period of time exceeding the maximum time.

5. The air conditioner according to claim 3, wherein During the execution of the second control, The control unit maintains the preset maximum frequency of the operating frequency at the first frequency based on the fact that the temperature of the indoor heat exchanger is equal to or higher than a predetermined limit temperature higher than the reference temperature. The control unit changes the maximum frequency to a second frequency lower than the first frequency based on the fact that the temperature of the indoor heat exchanger is lower than the limit temperature.

6. The air conditioner according to claim 1, wherein It also includes an indoor fan arranged adjacent to the indoor heat exchanger, The control unit controls the indoor fan to rotate at a first rotation speed during a first time period based on the determination that the first control is to be repeatedly performed. The control unit controls the indoor fan to rotate at a second rotation speed higher than the first rotation speed for a second time period longer than the first time period based on the determination that the first control is not to be repeatedly performed.

7. The air conditioner according to claim 6, wherein: If the second time has elapsed, the control part controls the indoor fan to rotate at a third rotation speed lower than the first rotation speed during a third time shorter than the second time.

8. The air conditioner according to claim 7, wherein: The device includes blades arranged at a discharge port, the discharge port discharges air flowing through the indoor fan, The control unit controls the blade to continuously change the direction in which the air is discharged through the discharge port during the second time period.

9. The air conditioner according to claim 1, wherein Also included is an outdoor temperature sensor for sensing the outdoor temperature. The control unit performs the first control based on the fact that the indoor temperature is within a first temperature range above zero and the outdoor temperature is within a second temperature range above zero. The control unit determines that the first control cannot be executed based on at least one of the indoor temperature being outside the first temperature range and the outdoor temperature being outside the second temperature range.

10. The air conditioner according to claim 1, wherein Also includes a communication interface for communicating with external devices, The control unit calculates the dew point temperature based on the temperature and humidity data corresponding to a predetermined location and a predetermined date and time received through the communication interface. The control unit determines the first target temperature based on a difference between the calculated dew point temperature and the indoor temperature.

11. The air conditioner according to claim 1, wherein The temperature of the indoor heat exchanger corresponds to a lower temperature of an inlet-side pipe temperature and an outlet-side pipe temperature of the indoor heat exchanger or an intermediate value between the inlet-side pipe temperature and the outlet-side pipe temperature of the indoor heat exchanger.

12. The air conditioner according to claim 1, wherein include: an indoor fan, disposed adjacent to the indoor heat exchanger; as well as a blade disposed at a discharge port, the discharge port discharging air flowing through the indoor fan; The control unit controls the blades so as to fix the direction in which the air is discharged to a first direction while executing the first control.

13. The air conditioner according to claim 12, wherein: include: If the second control is performed, the control portion controls the vane to raise the direction of blowing out the air to a second direction higher than the first direction, or controls the vane to close the blowout port.

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