air conditioner

Abstract

Invention details;

Description

air conditioner

[0001] The present invention relates to an air conditioner, and more particularly, to an air conditioner capable of removing foreign substances adsorbed on an indoor heat exchanger.

[0002] Air conditioners are installed to create a more pleasant indoor environment by discharging hot and cold air into the room, regulating the indoor temperature and purifying the indoor air. Typically, air conditioners include an indoor unit, which is equipped with a heat exchanger and installed indoors, and an outdoor unit, which includes a compressor and heat exchanger and supplies refrigerant to the indoor unit.

[0003] Air conditioners operate in either cooling or heating mode depending on the flow of refrigerant. During cooling mode, high-temperature, high-pressure liquid refrigerant is supplied to the indoor unit from the outdoor unit's compressor through the outdoor unit's heat exchanger. As the refrigerant expands and vaporizes in the indoor unit's heat exchanger, the temperature of the surrounding air drops, and as the indoor unit fan rotates, cool air is discharged into the room. During heating mode, high-temperature, high-pressure gaseous refrigerant is supplied to the indoor unit from the outdoor unit's compressor. As the high-temperature, high-pressure gaseous refrigerant liquefies in the indoor unit's heat exchanger, the released energy warms the air, and as the indoor unit fan rotates, cool air is discharged into the room.

[0004] Meanwhile, while the air conditioner is operating, foreign substances such as dust may adhere to the indoor unit's heat exchanger. For example, during cooling operation, condensate may be generated in the indoor unit's heat exchanger due to heat exchange between the refrigerant and indoor air. If some of this condensate forms on the surface of the heat exchanger or remains in the drain pipe, foreign substances may adhere to the condensate.

[0005] In this way, when foreign substances are absorbed into the heat exchanger of an indoor unit, microorganisms such as bacteria and mold can multiply due to the foreign substances, which can not only cause discomfort to the user but also have a detrimental effect on the user's health. Therefore, various studies are being conducted to remove foreign substances.

[0006] Conventional air conditioners, in order to remove foreign substances adsorbed on the heat exchanger of an indoor unit, etc., perform a defrosting operation to form frost on the surface of the heat exchanger of the indoor unit using a refrigerant cycle, as in Prior Art 1 (Japanese Patent Publication No. 2010-014288), and then remove the frost formed on the surface of the heat exchanger. At this time, as the water formed on the surface of the heat exchanger by the defrosting operation flows and is drained, foreign substances adsorbed on the heat exchanger of the indoor unit, etc., can be removed together with the water.

[0007] In addition, the conventional air conditioner may operate so that water droplets first condense on the surface of the heat exchanger before forming frost on the surface of the heat exchanger of the indoor unit, as in Prior Art 2 (Japanese Patent Publication No. 2018-200128), thereby allowing a larger amount of water to be drained when removing foreign substances.

[0008] The present disclosure aims to solve the above-mentioned and other problems.

[0009] Another purpose is to provide an air conditioner that can effectively remove foreign substances adsorbed on an indoor heat exchanger by only detecting the temperature.

[0010] Another purpose is to provide an air conditioner capable of preventing damage to the compressor that may occur while removing foreign substances adsorbed on the indoor heat exchanger.

[0011] Another purpose is to provide an air conditioner that can more effectively remove foreign substances adsorbed on an indoor heat exchanger by repeating an operation of removing foreign substances adsorbed on an indoor heat exchanger while considering whether the foreign substances adsorbed on the indoor heat exchanger are sufficiently removed.

[0012] In order to achieve the above object, an air conditioner according to one embodiment of the present invention includes: a compressor for compressing and discharging a refrigerant; an indoor heat exchanger for heat-exchanging the refrigerant with indoor air; a heat exchanger temperature sensor for detecting a temperature of the indoor heat exchanger; an indoor temperature sensor for detecting a temperature of the indoor air; and a control unit, wherein the control unit performs a primary control on the compressor based on a first target temperature for the temperature of the indoor heat exchanger corresponding to the temperature of the indoor air, and when the primary control is terminated, performs a secondary control on the compressor based on a second target temperature for the temperature of the indoor heat exchanger that is sub-zero and lower than the first target temperature, and when the secondary control is terminated, sets an operating frequency of the compressor to a preset minimum frequency for a predetermined period of time, and when the predetermined period of time has elapsed, determines whether to repeat the performance of the primary control based on a condition for the secondary control.

[0013] The effects of the air conditioner according to the present disclosure are described as follows.

[0014] According to at least one embodiment of the present disclosure, foreign substances adsorbed on an indoor heat exchanger can be effectively removed only by detecting temperature.

[0015] Additionally, according to at least one embodiment of the present disclosure, damage to the compressor that may occur while removing foreign substances adsorbed on the indoor heat exchanger can be prevented.

[0016] In addition, according to at least one embodiment of the present disclosure, by repeating an operation of removing foreign substances adsorbed on the indoor heat exchanger while considering whether the foreign substances adsorbed on the indoor heat exchanger are sufficiently removed according to the purpose, the foreign substances adsorbed on the indoor heat exchanger can be removed more effectively.

[0017] Further scope of the applicability of the present disclosure will become apparent from the detailed description below. However, since various modifications and variations within the spirit and scope of the present disclosure will become apparent to those skilled in the art, it should be understood that the detailed description and specific examples, such as preferred embodiments of the present disclosure, are given by way of example only.

[0018] FIG. 1 is a drawing illustrating an example of the configuration of an air conditioner according to one embodiment of the present invention.

[0019] Figure 2 is a schematic diagram of an outdoor unit and an indoor unit according to one embodiment of the present invention.

[0020] Figure 3 is a block diagram of an air conditioner according to one embodiment of the present invention.

[0021] Figures 4 to 6 are flowcharts illustrating an operating method of an air conditioner according to various embodiments of the present invention.

[0022] Figures 7 to 9 are drawings for reference in explaining the operation of an air conditioner according to various embodiments of the present invention.

[0023] Hereinafter, the present invention will be described in detail with reference to the drawings. In the drawings, portions irrelevant to the description are omitted to clearly and concisely explain the present invention. The same reference numerals are used throughout the specification for identical or extremely similar portions.

[0024] The suffixes "module" and "part" used in the following description are given solely for the convenience of writing this specification and do not impart any particularly significant meaning or role to the components themselves. Therefore, the terms "module" and "part" may be used interchangeably.

[0025] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0026] Additionally, while terms such as "first" and "second" may be used in this specification to describe various elements, these elements are not limited by these terms. These terms are used only to distinguish one element from another.

[0027] FIG. 1 is a drawing illustrating an example of the configuration of an air conditioner according to one embodiment of the present invention.

[0028] Referring to FIG. 1, an air conditioner (100) according to one 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 disclosure, the indoor unit (31) is described as being a wall-mounted air conditioner, but is not limited thereto.

[0029] Meanwhile, the air conditioner (100) may further include at least one of a ventilation device, an air purifier, a humidifier, and a heater, and may operate in conjunction with the operation of the indoor unit (31) and the outdoor unit (21).

[0030] 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 a refrigerant flow path according to heating operation, and an expansion valve (not shown) that expands the supplied refrigerant. In addition, the outdoor unit (21) may further include a number of sensors, valves, and an oil recovery device.

[0031] The outdoor unit (21) can operate the provided compressor and outdoor heat exchanger to compress or heat-exchange refrigerant according to settings and supply the refrigerant to the indoor unit (31). The outdoor unit (21) can be driven by a remote controller (not shown) or a demand from the indoor unit (31). At this time, as the cooling / heating capacity varies in response to the indoor unit (31) being driven, the number of outdoor units in operation and the number of compressors installed in the outdoor unit can also vary.

[0032] At this time, the outdoor unit (21) can supply compressed refrigerant to the connected indoor unit (31).

[0033] The indoor unit (31) can receive refrigerant from the outdoor unit (21) and discharge hot and cold air into the room.

[0034] The indoor unit (31) may include an indoor heat exchanger (not shown), an indoor unit fan (not shown), a number of sensors (not shown), etc.

[0035] The indoor unit (31) may include a drain pan (not shown) placed adjacent to the indoor heat exchanger to collect water generated by heat exchange of the indoor heat exchanger, and a drain pipe (not shown) that discharges water collected in the drain pan to the outside.

[0036] 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 to each other via a communication line and transmit and receive data. The outdoor unit (21) and the indoor unit (31) can also be connected to a remote controller (not shown) via wire or wirelessly and operate under the control of the remote controller (not shown).

[0037] The remote control (41) is connected to the indoor unit (31) and can transmit the user's control commands to the indoor unit (31). The remote control (41) can receive and display status information of the indoor unit (31). At this time, the remote control (41) can communicate with the indoor unit (31) by wire or wirelessly depending on the connection type.

[0038] Figure 2 is a schematic diagram of an outdoor unit and an indoor unit according to one embodiment of the present invention. Detailed descriptions of any details overlapping with those described in Figure 1 will be omitted.

[0039] Referring to FIG. 2, the outdoor unit (21) may include a compressor (102) that compresses 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) that is arranged on one side of the outdoor heat exchanger (104) to promote heat dissipation from the refrigerant, and a motor (105b) that rotates the outdoor fan (105a), an expansion valve (106) that expands condensed refrigerant, a cooling / heating switching valve (110) that changes the flow path of the compressed refrigerant, and an accumulator (103) that temporarily stores the vaporized refrigerant to remove moisture and foreign substances and then supplies the refrigerant at a constant pressure to the compressor.

[0040] The compressor (102) may be, for example, at least one of an inverter compressor and a constant-speed compressor.

[0041] The expansion valve (106) may be, for example, an electronic expansion valve (EEV).

[0042] The indoor unit (31) may include an indoor heat exchanger (108) that is placed indoors and performs a cooling / heating function, an indoor fan (109a) that is placed on one side of the indoor heat exchanger (108) and promotes heat dissipation of refrigerant, and an indoor blower (109) that is composed of a motor (109b) that rotates the indoor fan (109a).

[0043] The air conditioner (100) may include at least one indoor unit (31). When the air conditioner (100) includes a plurality of indoor units (31), a plurality of indoor heat exchangers (108) may be connected to each outdoor unit (21).

[0044] In addition, the air conditioner (100) may be configured as an air conditioner that cools the room, or may be configured as a heat pump that cools or heats the room.

[0045] Figure 3 is a block diagram of an air conditioner according to one embodiment of the present invention.

[0046] Referring to FIG. 3, the air conditioner (100) may include a communication interface (310), a sensor unit (320), a memory (330), a fan drive unit (340) that drives a fan (341), a compressor drive unit (350) that drives a compressor (102), and / or a control unit (370).

[0047] The communication interface (310) may include at least one communication module. For example, the communication interface (310) may be provided in each of the outdoor unit (21) and the indoor unit (31), and the outdoor unit (21) and the indoor unit (31) may transmit and receive data between each other.

[0048] The communication method between the outdoor unit (21) and the indoor unit (31) may be, for example, a communication method using a power line, a serial communication method (e.g., RS-485 communication), a wired communication method through a refrigerant pipe, or a wireless communication method such as Wi-fi, Bluetooth, Beacon, or Zigbee.

[0049] The communication interface (310) can transmit and receive data with external devices. For example, the communication interface (310) can connect to a server connected to an external network and transmit and receive data.

[0050] The sensor unit (320) may be equipped with at least one sensor and may transmit data on a detection value detected through the sensor to the control unit (370).

[0051] The sensor unit (320) may include a heat exchanger temperature sensor (321). The heat exchanger temperature sensor (321) may be disposed inside / outside the indoor heat exchanger (108) to detect the temperature of the indoor heat exchanger (108). For example, when the heat exchanger temperature sensor (321) is disposed outside the indoor heat exchanger (108), it may be disposed outside the heat exchanger or in 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.

[0052] The sensor unit (320) may be equipped with 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 in an inlet pipe of the indoor unit (31) and / or an outlet pipe of the indoor unit (31). For example, the pipe temperature sensor (323) may be disposed in a pipe connected to the compressor (102) and may detect the temperature of the refrigerant flowing into the compressor (102) (hereinafter, suction temperature) and / or the temperature of the refrigerant discharged from the compressor (102) (hereinafter, discharge temperature).

[0053] The sensor unit (320) may be equipped with an indoor temperature sensor (325) that detects indoor temperature and / or an outdoor temperature sensor (327) that detects outdoor temperature.

[0054] The sensor unit (320) may be equipped with a pressure sensor (not shown). The pressure sensor (not shown) may detect the pressure of the gaseous refrigerant flowing through each pipe of the air conditioner (100). For example, the pressure sensor may be placed in a pipe connected to the compressor (102) and may detect the pressure of the refrigerant flowing into the compressor (102) (hereinafter, suction pressure) and / or the pressure of the refrigerant discharged from the compressor (102) (hereinafter, discharge pressure).

[0055] The memory (330) can store data on reference values ​​related to the operation of each component provided in the air conditioner (100).

[0056] The memory (330) can store programs for signal processing and control within the control unit (370), and can store processed data and data to be processed. For example, the memory (330) can store application programs designed for the purpose of performing various tasks that can be processed by the control unit (370), and can selectively provide some of the stored application programs upon request from the control unit (370).

[0057] The memory (330) may include, for example, at least one of volatile memory (e.g., DRAM, SRAM, SDRAM, etc.) or non-volatile memory (e.g., flash memory, hard disk drive (HDD), solid-state drive (SSD), etc.).

[0058] The fan driving unit (340) can 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).

[0059] The fan driving unit (340) may include a rectifier (not shown) that rectifies AC power into DC power and outputs it, a dc capacitor (not shown) that stores a pulsating voltage from the rectifier, an inverter (not shown) that has a plurality of switching elements and converts and outputs smoothed DC power into three-phase AC power of a predetermined frequency, and / or at least one motor that drives a fan (341) according to three-phase AC power output from the inverter.

[0060] Meanwhile, the fan driving unit (340) may be provided with separate configurations 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).

[0061] The compressor driving unit (350) can drive the compressor (102). The compressor driving unit (350) may include a rectifier (not shown) that rectifies AC power into DC power and outputs it, a dc capacitor (not shown) that stores a pulsating voltage from the rectifier, an inverter (not shown) that has a plurality of switching elements and converts and outputs smoothed DC power into three-phase AC power of a predetermined frequency, and / or a compressor motor (102b) that drives the compressor (102) according to the three-phase AC power output from the inverter.

[0062] The vane (360) may be placed at the discharge port of the indoor unit (31) through which air flowing by the indoor fan (109a) is discharged. The air conditioner (100) may further include a vane motor that drives the vane (360), a link connected between the vane (360) and the vane motor, etc. For example, when the link rotates according to the rotation of the vane motor, the direction in which the vane (360) faces may change according to the rotation of the link. At this time, as the direction in which the vane (360) faces changes, the direction in which air is discharged through the discharge port of the indoor unit (31) (hereinafter, wind direction) may change. The vane motor may be implemented as a step motor, but is not limited thereto.

[0063] 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 transmit and / or receive signals between each component, thereby controlling the overall operation of each component.

[0064] The control unit (370) can control the operation of the fan drive unit (340) to change the rotation speed of the fan (341). For example, the fan drive unit (340) can change the rotation speed of the outdoor fan (105a) by changing the frequency of the three-phase AC power output to the outdoor fan motor (105b) under the control of the control unit (370). For example, the fan drive unit (340) can change the rotation speed of the indoor fan (109a) by changing the frequency of the three-phase AC power output to the indoor fan motor (109b) under the control of the control unit (370).

[0065] The control unit (370) can change the operating frequency of the compressor (102) by controlling the operation of the compressor drive unit (350). For example, the compressor drive unit (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) according to the control of the control unit (370).

[0066] The control unit (370) can change the wind direction. For example, when the wind direction is changed, the control unit (370) can rotate the vane motor so that the direction in which the vane (360) faces is changed.

[0067] The control unit (370) may be provided not only in the outdoor unit (21), but also in the indoor unit (31), a central controller (not shown) that controls the operation of the outdoor unit (21) and / or the indoor unit (31).

[0068] The control unit (370) may include at least one processor, and may control the overall operation of the air conditioner (100) using the processor included therein. Here, the processor may be a general processor such as a central processing unit (CPU). Of course, the processor may be a dedicated device such as an ASIC or another hardware-based processor.

[0069] The control unit (370) can obtain data related to each component equipped in the air conditioner (100). At this time, the control unit (370) can obtain data related to each component equipped in the air conditioner (100) at regular time intervals according to a predetermined cycle, taking into account the computational load.

[0070] The control unit (370) can perform various operations based on the acquired data and control the overall operation of each component provided in the air conditioner (100) according to the operation results.

[0071] Data related to each component provided in the air conditioner (100) may include, for example, the operating frequency of the compressor (102), the suction temperature of the compressor (102), the discharge temperature, the suction pressure, the discharge pressure, the inlet-side pipe temperature of the indoor unit (31), the outlet-side pipe temperature of the indoor unit (31), the indoor temperature, the outdoor temperature, the opening amount of the electronic expansion valve (EEV), etc.

[0072] Meanwhile, the air conditioner (100) may further include an input device (not shown) capable of receiving user input. For example, when the air conditioner (100) receives user input through an input device (e.g., a touch panel, a key, etc.), it may perform an operation corresponding to the received user input.

[0073] The air conditioner (100) may further include an output device (not shown) that outputs a message regarding the operating status of the air conditioner (100). For example, the output device may include a display device such as a display, a light emitting diode (LED), and / or an audio device such as a speaker or buzzer.

[0074] Figures 4 to 6 are flowcharts illustrating an operating method of an air conditioner according to various embodiments of the present invention.

[0075] Referring to FIG. 4, the air conditioner (100) can determine, in operation S410, whether the temperature conditions for initiating a function for removing foreign substances present on the surface of the indoor heat exchanger (108) (hereinafter, the foreign substance removal function) are satisfied. For example, the air conditioner (100) can determine the temperature conditions for initiating the foreign substance removal function based on receiving a user input for initiating the foreign substance removal function through a touch panel disposed on the remote control (41). For example, the air conditioner (100) can determine the temperature conditions for initiating the foreign substance removal function according to a preset cycle for performing the foreign substance removal function.

[0076] The temperature condition for initiating the foreign substance removal function may correspond to whether the indoor temperature and the outdoor temperature are each included in a predetermined temperature range. For example, the air conditioner (100) may determine that the temperature condition for initiating the foreign substance removal function is satisfied when the indoor temperature corresponds to a first temperature range of the image and the outdoor temperature corresponds to a second temperature range of the image. Here, the first temperature range and the second temperature range may be temperature ranges that can secure a predetermined cooling performance when the air conditioner (100) is driven as an air conditioner. For example, the first temperature range may be 21°C to 32°C, and the second temperature range may be 21°C to 37°C.

[0077] The air conditioner (100), in operation S420, may notify the user that removal of foreign substances is not possible if the temperature conditions for initiating the foreign substance removal function are not met. For example, the air conditioner (100) may output an indicator indicating that initiation of the foreign substance removal function is not possible through a display arranged in the remote control (41). Meanwhile, the air conditioner (100), if the temperature conditions for initiating the foreign substance removal function are not met, may continue performing the currently performed operation.

[0078] The air conditioner (100) may perform an operation related to condensation of moisture contained in indoor air (hereinafter, condensation operation) when the temperature condition for initiating the foreign substance removal function is satisfied in operation S430. Here, the condensation operation may refer to an operation of the air conditioner (100) that causes moisture contained in indoor air to form water droplets on the surface of the indoor heat exchanger (108). For example, the air conditioner (100) may perform the condensation operation for a preset time (hereinafter, condensation time) to perform the condensation operation.

[0079] The air conditioner (100), when it is determined to perform condensation operation, can check whether the compressor (102) is driven. At this time, if the compressor (102) is not driven, the air conditioner (100) can control the compressor drive unit (350) to start the compressor (102). For example, when the air conditioner (100) starts the compressor (102), the air conditioner (100) can control the operation of each component according to preset conditions so that the operating frequency of the compressor (102) reaches a predetermined frequency. The air conditioner (100) can control the operation of each component according to the cooling mode for cooling the indoor space. For example, when the air conditioner (100) starts the compressor (102), the air conditioner (100) can open the electronic expansion valve (EEV) according to a preset opening amount. Meanwhile, the air conditioner (100) can be judged to have a stabilized refrigerant cycle if the compressor (102) can sufficiently compress the introduced refrigerant into a high-temperature, high-pressure gaseous refrigerant according to the purpose.

[0080] The air conditioner (100) can determine a target temperature (hereinafter, condensation target temperature) for the temperature of the indoor heat exchanger (108) related to condensation. The condensation target temperature may 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 freezing of the water droplets. The condensation target temperature may correspond to the temperature of the indoor area. For example, the condensation target temperature may be a temperature lower than the current temperature of the indoor area by a predetermined temperature (e.g., 18°C) set in advance in relation to condensation. In the present disclosure, the temperature of the indoor heat exchanger (108) is described as reference, but is not limited thereto. For example, the air conditioner (100) may perform an operation based on a lower temperature among the inlet pipe temperature and the outlet pipe temperature of the indoor heat exchanger (108). For example, the air conditioner (100) can perform an operation based on the middle value of the inlet-side pipe temperature and the outlet-side pipe temperature of the indoor heat exchanger (108).

[0081] The air conditioner (100) can adjust the operating frequency of the compressor (102) based on the current temperature and the condensation target temperature of the indoor heat exchanger (108). For example, the air conditioner (100) can adjust the operating frequency of the compressor (102) in response to the difference between the current temperature of the indoor heat exchanger (108) and the condensation target temperature. At this time, the operating frequency of the compressor (102) can be higher as the difference between the current temperature of the indoor heat exchanger (108) and the condensation target temperature increases.

[0082] According to one embodiment, the air conditioner (100) can change a predetermined temperature associated with the determination of the condensation target temperature. The air conditioner (100) can receive data on temperature and humidity corresponding to a predetermined location and a predetermined time from a server connected to a network via a communication interface (310). The predetermined location may correspond to a location where the air conditioner (100) is installed. The predetermined time may correspond to a time, date, and / or period corresponding to the initiation of the foreign matter removal function.

[0083] The air conditioner (100) can determine a predetermined temperature based on data on temperature and humidity. The data on temperature and humidity can include dry bulb temperature, relative humidity, and / or dew point temperature. For example, when the data on temperature and humidity include dry bulb temperature and relative humidity, the air conditioner (100) can determine a dew point temperature corresponding to the dry bulb temperature and relative humidity based on a psychrometric chart.

[0084] The air conditioner (100) can set a predetermined temperature based on the difference between the indoor temperature and the dew point temperature. Referring to FIG. 7, a dew point temperature (700) corresponding to the indoor temperature can be determined based on data on temperature and humidity. At this time, the air conditioner (100) can determine a temperature that is a certain degree higher than the lowest value among the differences between the indoor temperature and the dew point temperature as the predetermined temperature. For example, when 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 lowest value. At this time, the air conditioner (100) can determine 17°C, which is a temperature that is 1°C or more and 2°C or less than the difference between the indoor temperature and the dew point temperature of 15.3°C, as the predetermined temperature.

[0085] Meanwhile, the air conditioner (100) may determine whether to perform the foreign substance removal function based on data received from the server. For example, the air conditioner (100) may check the dry bulb temperature, relative humidity, dew point temperature, etc. at a specific time based on data received from the server. At this time, the air conditioner (100) may determine to perform the foreign substance removal function if it is determined that moisture condensation occurs above a predetermined standard based on the dry bulb temperature, relative humidity, dew point temperature, etc. at a specific time. For example, the air conditioner (100) may determine to perform the foreign substance removal function based on the difference between the indoor temperature and the dew point temperature being less than a predetermined standard.

[0086] The air conditioner (100) can output a message recommending the performance of a foreign substance removal function through an output device. For example, the air conditioner (100) can output a message recommending the performance of a foreign substance removal function through a display arranged in a remote control (41) based on the difference between the indoor temperature and the dew point temperature being less than a first standard (e.g., 10°C). Meanwhile, the air conditioner (100) can output a message notifying that the performance of the foreign substance removal function is inappropriate through a display arranged in a remote control (41) based on the difference between the indoor temperature and the dew point temperature being greater than or equal to a second standard (e.g., 18°C).

[0087] The air conditioner (100) can control the vane (360) so that air is discharged according to a wind direction preset for the condensation operation while performing the condensation operation. For example, the wind direction can include an indirect wind in which the air flow is formed in the front direction of the air conditioner (100), a direct wind in which the air flow is formed in the lower direction of the air conditioner (100), and an oblique wind corresponding to a direction between the indirect wind and the direct wind. The air conditioner (100) can increase the angle of the vane (360) to form the indirect wind. Here, the angle of the vane (360) can be the angle formed by the vane (360) with a predetermined direction perpendicular to the ground. For example, the indirect wind can be formed when the angle of the vane (360) is the maximum value. In addition, the air conditioner (100) can decrease the angle of the vane (360) to form the direct wind. For example, a direct wind can be formed when the angle of the vane (360) is at a minimum value. At this time, the air conditioner (100) can control the vane (360) so that air is discharged according to the oblique wind while performing condensation operation.

[0088] The air conditioner (100) may rotate the indoor fan (109a) at a preset rotation speed corresponding to the condensation operation while performing the condensation operation. For example, the air conditioner (100) may rotate the indoor fan (109a) at a rotation speed corresponding to two of four preset rotation speeds while performing the condensation operation. Here, as the rotation speed step increases, the wind volume, which is the flow rate of air flowing by the indoor fan (109a), may increase according to the increase in the rotation speed. In the present disclosure, the rotation speed is described as being divided into four steps, but is not limited thereto.

[0089] According to one embodiment, the air conditioner (100) can determine whether to perform a condensation operation. For example, the air conditioner (100) may be preset to perform a condensation operation when performing an operation for removing foreign substances. For example, the air conditioner (100) can determine whether to perform the condensation operation in response to a user input received through a touch panel disposed on the remote control (41). At this time, if there is a history of receiving a user input regarding the performance of the condensation operation in the past, the air conditioner (100) may also determine whether to perform the condensation operation based on the history.

[0090] The air conditioner (100) can perform an operation related to freezing moisture (hereinafter, freezing operation) when the condensation operation is completed in operation S440. Here, the freezing operation may refer to an operation of the air conditioner (100) that causes ice to form on the surface of the indoor heat exchanger (108). Hereinafter, the freezing operation will be described in detail with reference to FIG. 5.

[0091] Referring to FIG. 5, the air conditioner (100) can check, in operation S510, whether the opening degree of the expansion valve (106) is less than the opening degree preset in relation to the start of the freezing operation (hereinafter, the freezing start opening degree). Here, the freezing start opening degree may be less than the opening degree of the expansion valve (106) at the time when the start of the compressor (102) is completed (hereinafter, the starting opening degree).

[0092] The air conditioner (100) can change the opening of the expansion valve (106) to the freezing start opening degree based on the fact that the opening degree of the expansion valve (106) exceeds the freezing start opening degree in operation S520.

[0093] The air conditioner (100) can control the compressor (102) in operation S530 according to a target temperature (hereinafter, “freezing target temperature”) for the temperature of the indoor heat exchanger (108) related to freezing. Here, the freezing target temperature can be determined in a sub-zero temperature range below 0°C. For example, the freezing target temperature can be preset to a predetermined temperature (e.g., -19°C) at which freezing of moisture condensed in the indoor heat exchanger (108) sufficiently occurs above a certain level.

[0094] The air conditioner (100) can 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, the air conditioner (100) can control the compressor drive unit (350) to increase the operating frequency of the compressor (102) when the current temperature of the indoor heat exchanger (108) is higher than the freezing target temperature.

[0095] The air conditioner (100) can determine, in operation S540, whether the current temperature of the indoor heat exchanger (108) is below a preset limit temperature. Here, the limit temperature may be preset to a temperature higher than the freezing target temperature. For example, the limit temperature may be preset to -10°C, which is a sub-zero temperature higher than the freezing target temperature of -19°C.

[0096] The air conditioner (100), in operation S550, can adjust the preset maximum frequency for the operating frequency of the compressor (102) based on whether the current temperature of the indoor heat exchanger (108) is lower than the preset limit temperature. For example, when the current temperature of the indoor heat exchanger (108) is higher than the limit temperature of -10°C, the maximum frequency for the operating frequency of the compressor (102) can be preset to a first frequency (e.g., 90 Hz). At this time, the air conditioner (100), based on whether the current temperature of the indoor heat exchanger (108) is lower than the limit temperature of -10°C, can change the maximum frequency for the operating frequency of the compressor (102) to a second frequency (e.g., 75 Hz) that is lower by a predetermined frequency (e.g., 15 Hz) than the first frequency. Through this, the temperature of the indoor heat exchanger (108) can be prevented from becoming excessively low. In addition, by preventing the operation of the compressor (102) from stopping due to an increase in the compression ratio of the compressor (102), freezing operation can be performed so that the moisture condensed in the indoor heat exchanger (108) is sufficiently frozen.

[0097] The air conditioner (100) can determine, in operation S560, whether the minimum time (hereinafter, "minimum freezing time") associated with the freezing operation has elapsed after the freezing operation has been initiated. Here, the minimum freezing time may be a time longer than the condensation time during which the condensation operation is performed. For example, the condensation time may be preset to 5 minutes, and the minimum freezing time may be preset to 10 minutes.

[0098] The air conditioner (100) can determine, in operation S570, whether the temperature of the indoor heat exchanger (108) is below the freezing target temperature based on the elapsed minimum freezing time. According to one embodiment, the air conditioner (100) can 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) is maintained below the freezing target temperature for a predetermined time (e.g., 10 seconds).

[0099] The air conditioner (100) can determine, in operation S580, whether the maximum time (hereinafter, maximum freezing time) associated with the performance of the freezing operation has elapsed based on the temperature of the indoor heat exchanger (108) being higher than the freezing target temperature. For example, the maximum freezing time can be preset to 15 minutes.

[0100] The air conditioner (100) can terminate the freezing operation when at least one of the following occurs: the temperature of the indoor heat exchanger (108) is lower than the freezing target temperature after the minimum freezing time has elapsed and the maximum freezing time has elapsed.

[0101] Meanwhile, the air conditioner (100) can control the vane (360) so that air is discharged in a different wind direction from the wind direction preset for the condensation operation through the discharge port of the indoor unit (31) while performing the freezing operation. For example, the air conditioner (100) can control the vane (360) so that air is discharged according to the indirect wind while performing the freezing operation. For example, the air conditioner (100) can control the vane (360) to close the discharge port of the indoor unit (31) while performing the freezing operation.

[0102] The air conditioner (100) can set the rotation speed of the outdoor fan (105a) to the maximum rotation speed while performing the freezing operation. The air conditioner (100) can adjust the rotation speed of the indoor fan (109a) while performing the freezing operation. For example, when the air conditioner (100) starts the freezing operation, it can rotate the indoor fan (109a) at a rotation speed corresponding to one of the four preset rotation speeds.

[0103] At this time, the air conditioner (100) can control the fan drive unit (340) so that the rotation speed of the indoor fan (109a) becomes lower than the current rotation speed when the inlet-side pipe temperature of the indoor unit (31) is higher than the preset upper limit temperature after a predetermined time (e.g., 12 minutes) has elapsed from the time the freezing operation is started. Here, the preset upper limit temperature may be a temperature (e.g., -5°C) corresponding to the highest temperature in the temperature range where freezing of moisture condensed in the indoor heat exchanger (108) can occur. Meanwhile, the air conditioner (100) can monitor the inlet-side pipe temperature of the indoor unit (31) at a predetermined cycle (e.g., 100 seconds) while performing the freezing operation. At this time, if the difference between the inlet-side pipe temperatures of the indoor unit (31) detected according to a predetermined cycle is less than a preset difference (e.g., 0.2°C), the fan drive unit (340) can be controlled so that the rotation speed of the indoor fan (109a) becomes lower than the current rotation speed. In the present disclosure, it is described that the rotation speed of the indoor fan (109a) is adjusted based on the inlet-side pipe temperature of the indoor unit (31), but is not limited thereto.

[0104] Referring again to FIG. 4, the air conditioner (100) may, in operation S450, perform a defrosting operation to melt ice formed on the surface of the indoor heat exchanger (108) when the freezing operation is completed. The air conditioner (100) may perform the defrosting operation for a preset time (hereinafter, the defrosting time). For example, the defrosting time may be shorter than the condensation time and the minimum freezing time.

[0105] The air conditioner (100) can rotate the indoor fan (109a) at a rotation speed corresponding to stage 1 or 2 of the four preset rotation speeds while performing defrosting operation.

[0106] The air conditioner (100) can set the operating frequency of the compressor (102) to a preset minimum frequency while performing the defrosting operation. Here, the minimum frequency may correspond to the minimum value of the operating frequency that can be lowered while the compressor (102) is operating. The air conditioner (100) can set the opening degree of the expansion valve (106) to a preset minimum opening degree while performing the defrosting operation. For example, the minimum opening degree may be a starting opening degree or a freezing initiation opening degree. For example, the minimum opening degree may be an opening degree smaller than the starting opening degree and the freezing initiation opening degree. The air conditioner (100) can set the rotation speed of the outdoor fan (105a) to a minimum rotation speed while performing the defrosting operation.

[0107] As 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 the minimum values, the refrigerant remaining in the indoor unit (31), the outdoor unit (21), and the pipe connecting the indoor unit (31) while the defrosting operation is performed can be recovered to the outdoor unit (102) to the maximum extent possible. Through this, problems such as damage to the compressor (102) and reduced efficiency that occur when liquid refrigerant flows into the compressor (102) can be prevented.

[0108] Meanwhile, the air conditioner (100) may stop the operation of the outdoor unit (21) when the defrosting time has elapsed. For example, the air conditioner (100) may stop the operation of the compressor (102). For example, the air conditioner (100) may stop the rotation of the outdoor fan (105a).

[0109] The air conditioner (100), in operation S460, can perform an operation (hereinafter, a dry operation) to remove condensed, frozen, and thawed moisture from the indoor heat exchanger (108) when the thawing time has elapsed. The air conditioner (100) can perform either a complete dry operation in which all moisture is removed from the indoor heat exchanger (108) or a partial dry operation in which some moisture is removed from the indoor heat exchanger (108). Hereinafter, the dry operation will be described in detail with reference to FIG. 6.

[0110] Referring to FIG. 6, the air conditioner (100) can determine whether the operation for removing foreign substances has been repeatedly performed in operation S610. For example, the air conditioner (100) can determine whether the condensation operation, freezing operation, and thawing operation have each been performed two or more times.

[0111] The air conditioner (100) can check whether the temperature of the indoor heat exchanger (108) has reached the freezing target temperature while performing the freezing operation if the operation for removing foreign substances is not repeated in the S620 operation.

[0112] In operation S630, the air conditioner (100) can determine whether the freezing operation was terminated when the temperature of the indoor heat exchanger (108) is higher than the freezing target temperature, or when the temperature of the indoor heat exchanger (108) is lower than a predetermined reference temperature higher than the freezing target temperature. For example, when the freezing target temperature is -19°C, the reference temperature can be preset to -17°C, which is higher than -19°C.

[0113] The air conditioner (100) can perform a partial drying operation when the freezing operation is terminated while the temperature of the indoor heat exchanger (108) is higher than the reference temperature in operation S640.

[0114] According to one embodiment, when the air conditioner (100) performs a partial drying operation, the air conditioner (100) may rotate the indoor fan (109a) at a rotation speed corresponding to a third stage among four preset rotation speeds for a first preset time period for performing the partial drying operation. At this time, the air conditioner (100) may control the vane (360) so that air is discharged according to a preset wind direction for the partial drying operation. For example, the air conditioner (100) may control the vane (360) so that air is discharged according to an indirect wind while performing the partial drying operation.

[0115] The air conditioner (100) may determine to repeatedly perform an operation for removing foreign substances in the S650 operation.

[0116] The air conditioner (100) can perform a complete drying operation when the freezing operation is terminated while the temperature of the indoor heat exchanger (108) is below the reference temperature in operation S660.

[0117] According to one embodiment, when the air conditioner (100) performs a complete drying operation, the air conditioner (100) may rotate the indoor fan (109a) at a rotation speed corresponding to the fourth stage among the four preset rotation speeds for a second period of time that is longer than the first period of time. At this time, the air conditioner (100) may change the direction in which the vane (360) faces so that the wind direction continuously changes during the second period of time. For example, the air conditioner (100) may drive the vane motor so that the wind direction continuously changes between direct wind and indirect wind during the second period of time. For example, the air conditioner (100) may control the direction in which the vane (360) faces so that it changes left and right. Through this, moisture can be uniformly dried in the entire area of ​​the indoor heat exchanger (108).

[0118] Meanwhile, the air conditioner (100) can rotate the indoor fan (109a) at a rotation speed corresponding to stage 2 among the four preset rotation speeds for a third period of time shorter than the second period of time after the second period of time has elapsed. At this time, the air conditioner (100) can control the vane (360) so that air is discharged according to the oblique wind during the third period of time.

[0119] The air conditioner (100) may decide to end the operation for removing foreign substances in operation S660.

[0120] Referring again to FIG. 4, the air conditioner (100) can determine, in operation S470, whether the operation for removing foreign substances has ended. If the air conditioner (100) repeats the operation for removing foreign substances, it can perform the condensation operation, the freezing operation, and / or the drying operation again.

[0121] Fig. 8 is a graph of the temperature of the indoor heat exchanger (108). Referring to Fig. 8, the air conditioner (100) can perform condensation operation until time t1, freezing operation from time t1 to time t2, thawing operation from time t2 to time t3, and drying operation from time t3.

[0122] 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 also correspond to the indoor temperature (T0). At this time, while the air conditioner (100) performs the condensation operation, the temperature of the indoor heat exchanger (108) may be lowered to a temperature (T1) below the dew point temperature. While the air conditioner (100) performs the freezing operation, the temperature of the indoor heat exchanger (108) may gradually decrease. At this time, as the temperature of the indoor heat exchanger (108) reaches the freezing target temperature (T2), the freezing operation may be terminated. Meanwhile, while the air conditioner (100) performs the thawing operation and the drying operation, the temperature of the indoor heat exchanger (108) may gradually increase.

[0123] Fig. 9 is a graph of the rotation speed of the indoor fan (109a). Referring to Fig. 9, the air conditioner (100) can rotate the indoor fan (109a) at a rotation speed corresponding to the second stage (f2) among the four preset rotation speeds while performing the condensation operation. The air conditioner (100) can rotate the indoor fan (109a) at a rotation speed corresponding to the first stage (f1) which is slower than the rotation speed (f2) in the condensation operation while performing the freezing operation. The air conditioner (100) can rotate the indoor fan (109a) at a rotation speed corresponding to the second stage (f2) which is faster than the rotation speed (f1) in the freezing operation while performing the thawing operation.

[0124] The air conditioner (100) can rotate the indoor fan (109a) at a rotation speed corresponding to the fourth stage (f4), which is the highest rotation speed, from time t3 to time t4, when the complete drying operation is performed. Meanwhile, the air conditioner (100) can rotate the indoor fan (109a) again at a rotation speed corresponding to the second stage (f2), from time t4, when the complete drying operation is performed.

[0125] As described above, according to at least one embodiment of the present invention, foreign substances adsorbed on an indoor heat exchanger (108) can be effectively removed only by detecting temperature.

[0126] Additionally, according to at least one embodiment of the present disclosure, damage to the compressor (102) that may occur while removing foreign substances adsorbed on the indoor heat exchanger (108) can be prevented.

[0127] In addition, according to at least one embodiment of the present disclosure, by repeating the operation of removing foreign substances adsorbed on the indoor heat exchanger (108) while considering whether the foreign substances adsorbed on the indoor heat exchanger (108) are sufficiently removed according to the purpose, the foreign substances adsorbed on the indoor heat exchanger (108) can be removed more effectively.

[0128] The attached drawings are only intended to facilitate understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

[0129] Likewise, while operations are depicted in a particular order in the drawings, this should not be construed as requiring that those operations be performed in the particular or sequential order depicted to achieve desired results, or that all illustrated operations be performed. In certain cases, multitasking and parallel processing may be advantageous.

[0130] In addition, although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and various modifications can be made by a person having ordinary skill in the art to which the present invention pertains without departing from the gist of the present invention as claimed in the claims, and such modifications should not be understood individually from the technical idea or prospect of the present invention.

Claims

DEPCT6826 / 08 / 25681. An air conditioning system comprising: a compressor configured to compress and discharge refrigerant, an indoor heat exchanger configured to exchange heat between the refrigerant and the indoor air, a sensor unit configured to detect the temperature of the indoor heat exchanger and the indoor temperature, and a controller which is configured to: perform primary control of the compressor based on a first target temperature for the indoor heat exchanger, which corresponds to the indoor temperature; perform secondary control of the compressor based on a second target temperature below zero for the indoor heat exchanger, when primary control ends and the second target temperature is less than the first target temperature; set the compressor operating frequency to a predetermined minimum frequency for a predetermined period, when secondary control ends; and determine whether to repeat primary control based on the conditions for secondary control after the predetermined period has elapsed.2.The air conditioning system under Claim 1 includes, in addition to: a pressure reducing valve configured to cause the refrigerant flowing into the indoor heat exchanger to expand; an outdoor heat exchanger configured to exchange heat between the refrigerant and the outdoor air; and an outdoor fan configured to be attached to the outdoor heat exchanger, where the controller is configured to: set the opening angle of the pressure reducing valve to a predetermined minimum opening angle for a predetermined period of time; and set the rotation speed of the outdoor fan to a predetermined minimum rotation speed for a predetermined period of time. 3.The air conditioner under claim 1, where the controller is configured to: determine not to repeat the primary control when the secondary control ends while the indoor heat exchanger temperature is below the determined pre-set reference temperature which is greater than the second target temperature; and determine to repeat the primary control when the secondary control ends while the indoor heat exchanger temperature is at or above the 4th reference temperature.The air conditioning system under claim 3, where, while performing secondary control, the controller shall be configured to: verify that the indoor heat exchanger temperature is less than or equal to the second target temperature, based on the secondary control being performed for a minimum preset period or more; verify that the secondary control is performed for a maximum preset period or more, based on the indoor heat exchanger temperature exceeding the second target temperature; and terminate the secondary control based on at least one of the indoor heat exchanger temperatures being less than or equal to the second target temperature and the secondary control being performed for the maximum period or more.An air conditioner under claim 3, where, while performing secondary control, the controller is configured to: maintain the preset maximum frequency for the operating frequency at frequency one, based on the indoor heat exchanger temperature being greater than or equal to a predetermined limit temperature higher than the reference temperature, and change the maximum frequency to frequency two, which is lower than frequency one, based on the indoor heat exchanger temperature being lower than limit temperature 6. An air conditioner under claim 1, which is additionally incorporated with an indoor fan arranged adjacent to the indoor heat exchanger, where the controller is configured to: control the indoor fan to rotate at speed one for a period of one, based on a predetermined decision to repeat the primary control; control the indoor fan to rotate at speed two, which is higher than speed one, for a period of two longer than the period of one, based on a predetermined decision not to repeat the primary control 7.

8. An air conditioner under claim 7, which incorporates additional impellers arranged at an outlet through which the air moved by the indoor fan is released, where the controller is arranged to control the impeller's change of direction through which the air is released through the outlet continuously during the second period. 9.The air conditioner under claim 1, which includes an additional outdoor temperature sensor configured to detect the outdoor temperature where the controller is configured: performs primary control based on the indoor temperature corresponding to the first temperature range which is above zero and the outdoor temperature corresponding to the second temperature range which is above zero, and determines that primary control cannot be performed based on at least one indoor temperature outside the first temperature range and an outdoor temperature outside the second temperature range.

10. The air conditioner under claim 1, which includes an additional communication interface configured to communicate with the external device where the controller is configured: calculates the dew point temperature based on temperature and humidity data corresponding to a predetermined location and a predetermined date and time received via the communication interface, and determines the first target temperature based on the difference between the calculated dew point temperature and the indoor temperature.11.

11. An air conditioner under claim 1 where the temperature of the indoor heat exchanger corresponds to the lower temperature between the inlet and outlet pipe temperatures of the indoor heat exchanger or the intermediate value between the inlet and outlet pipe temperatures of the indoor heat exchanger.

12. An air conditioner under claim 1 which includes additionally: an indoor fan arranged in conjunction with the indoor heat exchanger and a vane arranged at the outlet through which the air moved by the indoor fan is released through the section where, during primary control operation, the controller is configured to control the vane in such a way that the direction of air release is fixed to direction one.

13. An air conditioner under claim 12 where, during secondary control operation, the controller is configured to control the vane in such a way that the direction of air release is shifted to direction two, which is higher than direction one, or controls the vane to close the outlet.

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