Air conditioner

Abstract

The invention relates to an air conditioner, which belongs to the technical field of air conditioners and comprises an indoor unit, an indoor heat exchanger, an outdoor unit, an outdoor heat exchanger, a compressor, a coping temperature sensor and a controller, the coping temperature sensor is used for detecting the temperature of the top of the compressor and obtaining the temperature value of the compressor. The controller is configured to enter an oil return mode if the time when the rotating speed of the compressor is lower than the preset rotating speed exceeds the interval time; in the oil return mode; controlling a coping temperature sensor to obtain a temperature value of the compressor; if the difference value between the compressor temperature value and the condensation temperature value is smaller than the first preset temperature difference, the oil return rotating speed is obtained through first logic calculation; if the difference value between the compressor temperature value and the condensation temperature value is larger than the second preset temperature difference, the oil return rotating speed is obtained through second logic calculation; the rotating speed of the compressor is controlled to be increased to the oil return rotating speed, and after continuous operation reaches the oil return duration, oil return operation control is stopped.

Description

Technical Field

[0001] This application relates to the technical field of air conditioners, and particularly to an air conditioner. Background Art

[0002] An air conditioner, i.e., an air regulator, refers to a device that uses artificial means to adjust and control parameters such as the temperature, humidity, and flow rate of the indoor environmental air in a building or structure.

[0003] In the prior art, it often occurs that the minimum cooling capacity of an air conditioner is much greater than the gradually decreasing indoor heat load. Since the operating speed of the compressor is positively correlated with the cooling capacity of the air conditioner. Therefore, the conventional practice of existing air conditioner manufacturers is to lower the lower limit of the operating speed of the air conditioner compressor, so that the minimum cooling capacity of the air conditioner is reduced, and it better matches the indoor heat load.

[0004] However, in the above solution, when the compressor continuously operates at a low speed, most air conditioning systems will trigger an oil return operation. During the oil return operation, the speed of the compressor is increased to the oil return speed and continues to operate for a period of time. By increasing the flow rate of the refrigerant in the air conditioning system, the lubricating oil remaining in the heat exchanger and pipeline is returned to the compressor. During the oil return operation, when the speed of the compressor increases, correspondingly, the heat generation of the compressor becomes larger, the heat dissipation becomes smaller, the bottom superheat is increased, and the oil viscosity is also increased, which improves the reliability of the compressor to a certain extent. However, the conventional oil return control parameters of the air conditioning system are all set to fixed values and cannot be adjusted according to the operating conditions of the air conditioner. If the oil return control cannot ensure the lower limit of the bottom superheat of the compressor, the compressor will be severely worn and cause air conditioner failures; if too much cooling capacity is generated during the oil return control and the indoor temperature drops too much, it is easy to cause the phenomenon of shutting down when the set temperature is reached, and the user experience is poor. Summary of the Invention

[0005] The present invention solves at least one of the technical problems in the related art to some extent.

[0006] Therefore, this application aims to provide an air conditioner. In the oil return mode, it is divided into multiple situations according to the relationship between the temperature value of the compressor and the temperature difference of the condensing temperature value, so as to adjust the oil return speed for different situations, so as to achieve stable operation of the oil return mode and avoid frequent start and stop of the compressor, and improve the user experience while ensuring the reliability of the compressor.

[0007] To achieve the above object, the present invention provides an air conditioner, including: An indoor unit; An indoor heat exchanger, which is arranged in the indoor unit; An outdoor unit; An outdoor heat exchanger, which is arranged in the outdoor unit, and the outdoor heat exchanger is communicated with the indoor heat exchanger; A compressor, which is disposed inside the outdoor unit and is used to deliver refrigerant to the outdoor heat exchanger and the indoor heat exchanger; A top temperature sensor, which is used to detect the temperature at the top of the compressor and obtain a compressor temperature value; A controller, which is configured to: enter an oil return mode if the time during which the rotational speed of the compressor is lower than a preset rotational speed exceeds an interval time; in the oil return mode, control the top temperature sensor to obtain the compressor temperature value; If the difference between the compressor temperature value and the condensation temperature value is less than a first preset temperature difference, calculate an oil return rotational speed through a first logical calculation; If the difference between the compressor temperature value and the condensation temperature value is greater than a second preset temperature difference, calculate an oil return rotational speed through a second logical calculation; Control the rotational speed of the compressor to increase to the oil return rotational speed and continue to operate for an oil return duration before exiting the oil return operation control.

[0008] In the technical solution, in the oil return mode, multiple situations are classified according to the relationship between the compressor temperature value and the condensation temperature value, and the oil return rotational speed is adjusted for different situations to achieve stable operation of the oil return mode and avoid frequent start and stop of the compressor, improving the user experience while ensuring the reliability of the compressor.

[0009] In addition, the present application also provides an air conditioner, which includes: An indoor unit; An indoor heat exchanger, which is disposed inside the indoor unit; An outdoor unit; An outdoor heat exchanger, which is disposed inside the outdoor unit and is connected to the indoor heat exchanger; A compressor, which is disposed inside the outdoor unit and is used to deliver refrigerant to the outdoor heat exchanger and the indoor heat exchanger; An exhaust temperature sensor, which is used to detect the exhaust temperature of the compressor and obtain a compressor temperature value; A controller, which is configured to: enter an oil return mode if the time during which the rotational speed of the compressor is lower than a preset rotational speed exceeds an interval time; in the oil return mode, control the exhaust temperature sensor to obtain the compressor temperature value; If the difference between the compressor temperature value and the condensation temperature value is less than a first preset temperature difference, calculate an oil return rotational speed through a first logical calculation; If the difference between the compressor temperature value and the condensation temperature value is greater than a second preset temperature difference, calculate an oil return rotational speed through a second logical calculation; Control the rotation speed of the compressor to increase to the oil return rotation speed, and continue to run. After reaching the oil return duration, exit the oil return operation control.

[0010] In the technical solution, in the oil return mode, it is divided into multiple situations according to the relationship between the temperature difference between the compressor temperature value and the condensation temperature value, so as to adjust the oil return rotation speed for different situations, so as to realize the stable operation of the oil return mode and avoid frequent start and stop of the compressor, improving the user experience while ensuring the reliability of the compressor.

[0011] In some embodiments of the present application, a first temperature sensor is provided in the indoor unit, and the first temperature sensor is used to detect the temperature of the indoor heat exchanger; a second temperature sensor is provided in the outdoor unit, and the second temperature sensor is used to detect the temperature of the outdoor heat exchanger; The controller is configured to: in the oil return mode, in the refrigeration mode, control the second temperature sensor to detect the temperature value of the outdoor heat exchanger to obtain the condensation temperature value; In the heating mode, control the first temperature sensor to detect the temperature value of the indoor heat exchanger to obtain the condensation temperature value.

[0012] In some embodiments of the present application, the first logic is: F2 = F1 + 2×(5 - Td + Tc); The second logic is: F2 = F1 - 2×(10 - Td + Tc); Wherein, F2 is the oil return rotation speed of the current oil return mode; F1 is the oil return rotation speed in the previous oil return mode; Td is the compressor temperature value; Tc is the condensation temperature value.

[0013] In the technical solution, through this solution, different scenarios or working conditions are distinguished, and the oil return rotation speed of the current oil return mode is calculated for different situations, so as to ensure that the oil return rotation speed can conform to the current scenario and improve the reliability of the compressor.

[0014] In some embodiments of the present application, the controller is configured to: if F2 is greater than the oil return upper limit value, control the value of F2 to be the oil return upper limit value; Or if F2 is less than the oil return lower limit value, control the value of F2 to be the oil return lower limit value.

[0015] In the technical solution, ensure that the oil return rotation speed is within the range between the oil return upper limit value and the oil return lower limit value, and avoid the influence of excessive or too low oil return rotation speed on the wear of the compressor and the noise on the user.

[0016] In some embodiments of the present application, the controller is configured to: if the number of times the oil return mode runs reaches a first preset number of times, and in all of these preset times, F2 is equal to the oil return upper limit value or F2 is equal to the oil return lower limit value, then start the first adjustment stage; In the first adjustment stage: obtain the condensation temperature value; if it is determined that the difference between the compressor temperature value and the condensation temperature value is less than a first preset temperature difference, then increase the oil return duration in this oil return mode by a first time increment on the basis of the current oil return duration; If the difference between the compressor temperature value and the condensation temperature value is greater than a second preset temperature difference, then subtract a first time decrement from the oil return duration in this oil return mode on the basis of the current oil return duration.

[0017] In the technical solution, when adjusting the oil return speed multiple times fails to achieve the desired effect, by changing the oil return duration of the oil return mode, the oil return mode is made to conform to the current scenario, improving the reliability of the compressor. Since the extension or shortening of the oil return duration has a greater impact on the user than the oil return speed, in this application, the oil return speed is adjusted first. When the oil return speed cannot achieve the effect, the oil return duration is adjusted. This minimizes the impact on the user and improves the user experience to the greatest extent.

[0018] In some embodiments of the present application, the controller is configured to: if the first adjustment stage runs continuously for a second preset number of times; then start the second adjustment stage; In the second adjustment stage; if it is determined that the difference between the compressor temperature value and the condensation temperature value is less than a first preset temperature difference, then subtract a second time difference from the interval time until the next oil return mode operation on the basis of the current interval time; If the difference between the compressor temperature value and the condensation temperature value is greater than a second preset temperature difference, then increase the interval time until the next oil return mode operation by a second time increment on the basis of the current interval time.

[0019] In the technical solution, when adjusting the oil return duration multiple times fails to achieve the desired effect, by changing the interval time of the oil return mode, the oil return mode is made to conform to the current scenario, improving the reliability of the compressor. Since the extension or shortening of the interval time of the oil return mode has a greater impact on the user than the oil return duration, in this application, the oil return speed is adjusted first. When the oil return speed cannot achieve the effect, the oil return duration is adjusted. When the oil return duration also cannot achieve the effect, finally, the interval time of the oil return mode, which has the greatest impact on the user, is adjusted. This minimizes the impact on the user and improves the user experience to the greatest extent.

[0020] In some embodiments of the present application, an indoor fan is provided inside the indoor unit; The controller is configured to: after entering the oil return mode, reduce the rotational speed of the indoor fan so that the temperature of the indoor heat exchanger coil is within a preset range.

[0021] In the technical solution, through this solution, the evaporation pressure is reduced in the refrigeration mode and the condensation pressure is increased in the heating mode, so as to reduce the heat dissipation inside the compressor or increase the heat generation inside the compressor, increase the internal temperature of the compressor, and at the same time, the indoor heat exchange amount can be reduced, and the probability of the indoor unit stopping when reaching the set temperature can be reduced, thereby improving the user experience.

[0022] In some embodiments of the present application, an outdoor fan is provided inside the outdoor unit; The controller is configured to: after entering the oil return mode, reduce the rotational speed of the outdoor fan.

[0023] In the technical solution, the condensation pressure is increased or the evaporation pressure is reduced to reduce the heat dissipation inside the compressor or increase the heat generation inside the compressor, increase the internal temperature of the compressor, and at the same time, the indoor heat exchange amount can be reduced, and the probability of the indoor unit stopping when reaching the set temperature can be reduced, thereby improving the user experience.

[0024] In some embodiments of the present application, the indoor unit has an air outlet of the air conditioner, and a wind deflector is provided at the air outlet of the air conditioner; The controller is configured to: after entering the oil return mode, control the wind deflector to move to a preset position.

[0025] In the technical solution, it is avoided that the air flow blows on the user, the indoor air volume is reduced to reduce the heat exchange amount, so as to reduce the probability of the air conditioner stopping when reaching the set temperature, ensure the comfort of the user, and at the same time, the evaporation temperature will be reduced or the condensation temperature will be increased, the heat dissipation amount of the compressor will be reduced or the heat generation amount of the compressor will be increased, and the internal temperature of the compressor will be increased.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0027] Figure 1 is a schematic diagram of the overall structure of an air conditioner according to an embodiment of the present application; Figure 2 is a schematic diagram of the structure of an air conditioner according to an embodiment of the present application; Figure 3 is a working flow chart of an air conditioner according to an embodiment of the present application; Figure 4 is a working flow chart of an air conditioner according to an embodiment of the present application; Figure 5 is a working flow chart of an air conditioner according to an embodiment of the present application; Figure 6 is the working flow chart of an air conditioner according to an embodiment of the present application Figure 7 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 8 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 9 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 10 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 11 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 12 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 13 is the working flow chart of an air conditioner according to an embodiment of the present application; Figure 14 is the working flow chart of an air conditioner according to an embodiment of the present application.

[0028] In the above figures: 100, indoor unit; 200, outdoor unit; 300, indoor heat exchanger; 400, outdoor heat exchanger; 500, compressor. Specific Embodiments

[0029] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the present invention, unless otherwise clearly defined or limited, a first feature being "on" or "under" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact via an intermediate medium. Further, a first feature being "above", "over" or "on top of" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher level height than the second feature. A first feature being "under", "below" or "beneath" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower level height than the second feature. In the present invention, the terms "an embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0030] Next, the present invention will be specifically described by way of exemplary embodiments. However, it should be understood that, without further narration, the elements, structures, and features in one embodiment may also be beneficially combined into other embodiments. In this application, the air conditioner performs the refrigeration cycle of a wall-mounted air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, throttling, and evaporation, and supplies cold or heat to the air that has been conditioned and heat-exchanged. The compressor compresses the refrigerant gas in a low-temperature and low-pressure state and discharges the refrigerant gas in a high-temperature and high-pressure state. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process. The expansion valve throttles the high-temperature and high-pressure liquid-phase refrigerant condensed in the condenser into a low-pressure gas-liquid two-phase refrigerant.

[0031] In the evaporator, after the refrigerant expanded in the expansion valve absorbs heat and evaporates, it is in a low-temperature and low-pressure state, and then the refrigerant gas returns to the compressor. The evaporator can achieve a refrigeration effect by using the latent heat of vaporization of the refrigerant to perform a heat exchange with the material to be cooled.

[0032] The air conditioner includes an indoor unit and an outdoor unit, and the indoor unit includes a body. During the whole cycle, the air conditioner can adjust the temperature of the indoor space. The outdoor unit of the wall-mounted air conditioner refers to the part of the refrigeration cycle including a compressor and an outdoor heat exchanger, and the indoor unit of the wall-mounted air conditioner includes an indoor heat exchanger, and an expansion valve can be provided in the indoor unit or the outdoor unit. The indoor heat exchanger and the outdoor heat exchanger can be used as a condenser or an evaporator respectively. When the indoor heat exchanger is used as a condenser, the air conditioner serves as a heater in the heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner serves as a cooler in the cooling mode.

[0033] Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0034] As shown in the attached Figure 1 and Figure 2 In a schematic embodiment of the air conditioner of the present invention, the air conditioner includes: an indoor unit 100, an indoor heat exchanger 300, an outdoor unit 200, an outdoor heat exchanger 400, a compressor 500, a top temperature sensor, and a controller; wherein, the indoor heat exchanger 300 is disposed in the indoor unit 100; the outdoor heat exchanger 400 is disposed in the outdoor unit 200, and the outdoor heat exchanger 400 is communicated with the indoor heat exchanger 300; the compressor 500 is disposed in the outdoor unit 200, and the compressor 500 is used to transport refrigerant to the outdoor heat exchanger 400 and the indoor heat exchanger 300; the top temperature sensor is used to detect the temperature at the top of the compressor 500 and obtain a compressor temperature value.

[0035] Please refer to Figures 3 to 14 , the controller is configured to: if the time when the rotation speed of the compressor 500 is lower than the preset rotation speed exceeds the interval time, enter the oil return mode; in the oil return mode; control the top temperature sensor to obtain the compressor temperature value; if the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, calculate the oil return rotation speed through the first logic calculation; if the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, calculate the oil return rotation speed through the second logic calculation; control the rotation speed of the compressor 500 to increase to the oil return rotation speed, and continue to run for the oil return duration and then exit the oil return operation control.

[0036] Through the above solution, in the oil return mode, according to the relationship between the temperature difference between the compressor temperature value and the condensation temperature value, there are multiple situations, and the oil return rotation speed is adjusted for different situations to achieve stable operation of the oil return mode and avoid frequent start and stop of the compressor 500, improving the user experience while ensuring the reliability of the compressor 500.

[0037] In the prior art, a discharge temperature sensor has been provided inside the outdoor unit 200 of some air conditioners, which is used to detect the temperature at the top of the compressor 500. In this application, when facing this type of model, the discharge temperature sensor can be directly used without the need to separately set a temperature sensor, saving costs.

[0038] Please refer to Figure 1 and Figure 2 In addition, this application also provides an air conditioner, which includes: an indoor unit 100, an indoor heat exchanger 300, an outdoor unit 200, an outdoor heat exchanger 400, a compressor 500, a discharge temperature sensor, and a controller; wherein, the indoor heat exchanger 300 is arranged inside the indoor unit 100; the outdoor heat exchanger 400 is arranged inside the outdoor unit 200, and the outdoor heat exchanger 400 is communicated with the indoor heat exchanger 300; the compressor 500 is arranged inside the outdoor unit 200, and the compressor 500 is used to convey refrigerant to the outdoor heat exchanger 400 and the indoor heat exchanger 300; the discharge temperature sensor is used to detect the discharge temperature of the compressor 500 and obtain a compressor temperature value.

[0039] Please refer to Figures 3 to 14 The controller is configured to: if the time when the rotation speed of the compressor 500 is lower than the preset rotation speed exceeds the interval time, enter the oil return mode; in the oil return mode, control the discharge temperature sensor to obtain the compressor temperature value; if the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, calculate the oil return rotation speed through the first logic calculation; if the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, calculate the oil return rotation speed through the second logic calculation; control the rotation speed of the compressor 500 to increase to the oil return rotation speed, and continue to operate for the oil return duration and then exit the oil return operation control.

[0040] Through the above solution, in the oil return mode, according to the relationship between the difference between the compressor temperature value and the condensation temperature value, there are multiple situations, and the oil return rotation speed is adjusted for different situations to achieve stable operation of the oil return mode and avoid frequent start and stop of the compressor 500, improving the user experience while ensuring the reliability of the compressor 500.

[0041] In the prior art, a discharge temperature sensor has been provided inside the outdoor unit 200 of some air conditioners, which is used to detect the discharge temperature of the compressor 500. In this application, when facing this type of model, the discharge temperature sensor can be directly used without the need to separately set a temperature sensor, saving costs.

[0042] In some embodiments, the indoor unit 100 is disposed indoors, and the outdoor unit 200 is disposed outdoors. The indoor heat exchanger 300 is connected and communicated with the outdoor heat exchanger 400. The refrigerant is caused to flow between the indoor heat exchanger 300 and the outdoor heat exchanger 400 by the compressor 500 to achieve a change in the temperature of the indoor heat exchanger 300. The air flow passing through the indoor heat exchanger 300 is heated and then flows into the room to achieve a change in the indoor temperature.

[0043] In some embodiments, when the air conditioner first operates in the oil return mode, the oil return speed, the oil return duration, and the interval time in the oil return mode are all preset values. The specific values can be preset at the factory, sent from the cloud, preset by the user, and other forms.

[0044] Please refer to Figures 3 to 14 , in some embodiments, the controller is configured to: determine whether the speed of the compressor 500 is lower than the preset speed. If not, it operates in the current state. If so, record the running time and determine whether the running time exceeds the interval time. If not, continue to record the running time. If so, enter the oil return mode.

[0045] In some embodiments, after entering the oil return mode, if the compressor temperature value minus the condensation temperature value is less than the first preset temperature difference, the oil return speed of the current oil return mode is calculated through the first logical calculation.

[0046] In some embodiments, the first preset temperature difference is 15°C.

[0047] In some embodiments, after entering the oil return mode, if the compressor temperature value minus the condensation temperature value is greater than the second preset temperature difference, the oil return speed of the current oil return mode is calculated through the second logical calculation.

[0048] In some embodiments, the second preset temperature difference is 25°C.

[0049] In some embodiments, a first temperature sensor is disposed inside the indoor unit 100, and the first temperature sensor is configured to detect the temperature of the indoor heat exchanger 300; a second temperature sensor is disposed inside the outdoor unit 200, and the second temperature sensor is configured to detect the temperature of the outdoor heat exchanger 400; the controller is configured to: in the oil return mode, in the cooling mode and the dehumidification mode, control the second temperature sensor to detect the temperature value of the outdoor heat exchanger 400 to obtain the condensation temperature value; in the heating mode, control the first temperature sensor to detect the temperature value of the indoor heat exchanger 300 to obtain the condensation temperature value. The condensation temperature is mainly the temperature of the condenser. When the air conditioner is in the cooling mode and the dehumidification mode, the indoor heat exchanger 300 is used as an evaporator, and the outdoor heat exchanger 400 is used as a condenser. Therefore, the temperature value of the outdoor heat exchanger 400 is detected by the second temperature sensor. When the air conditioner is in the heating mode, the outdoor heat exchanger 400 is used as an evaporator, and the indoor heat exchanger 300 is used as a condenser. Therefore, the temperature value of the indoor heat exchanger 300 is detected by the first temperature sensor.

[0050] Please refer to Figures 3 to 14 , in some embodiments, the first logic is: F2 = F1 + 2×(5 - Td + Tc); the second logic is: F2 = F1 - 2×(10 - Td + Tc); where F2 is the oil return speed of the current oil return mode; F1 is the oil return speed in the previous oil return mode; Td is the compressor temperature value; Tc is the condensation temperature value. Through this solution, different scenarios or different working conditions are distinguished, and the oil return speed of the current oil return mode is calculated for different situations to ensure that the oil return speed can conform to the current scenario and improve the reliability of the compressor 500.

[0051] Hereinafter, the oil return speed F2 in the current oil return mode is simply referred to as the current oil return speed F2; the oil return speed F1 in the previous oil return mode is simply referred to as the previous oil return speed F1.

[0052] Please refer to Figures 3 to 14, in some embodiments, at the start of the oil return mode, it is determined whether the current mode is the cooling mode or the heating mode. If it is the heating mode, the first temperature sensor is controlled to detect the temperature value of the indoor heat exchanger 300 to obtain the condensation temperature value; if it is the cooling mode or the dehumidification mode, the second temperature sensor is controlled to detect the temperature value of the outdoor heat exchanger 400 to obtain the condensation temperature value. The top temperature sensor is controlled to obtain the compressor temperature value. It is determined whether the compressor temperature value minus the condensation temperature value is less than the first preset temperature difference; if so, the value of the current oil return speed F2 is calculated by F2 = F1 + 2×(5 - Td + Tc); if not, it is determined whether the compressor temperature value minus the condensation temperature value is greater than the second preset temperature difference; if so, the value of the current oil return speed F2 is calculated by F2 = F1 - 2×(10 - Td + Tc); if not, the oil return mode is exited, and the current oil return duration, oil return speed, and interval time are applied to the current oil return mode.

[0053] Further, the controller is configured to: at the start of the oil return mode, determine whether the current mode is the heating mode. If so, control the first temperature sensor to detect the temperature value of the indoor heat exchanger 300 to obtain the condensation temperature value; if not, control the second temperature sensor to detect the temperature value of the outdoor heat exchanger 400 to obtain the condensation temperature value. The top temperature sensor is controlled to obtain the compressor temperature value. It is determined whether the compressor temperature value minus the condensation temperature value is less than the first preset temperature difference; if so, the value of the current oil return speed F2 is calculated by F2 = F1 + 2×(5 - Td + Tc); if not, it is determined whether the compressor temperature value minus the condensation temperature value is greater than the second preset temperature difference; if so, the value of the current oil return speed F2 is calculated by F2 = F1 - 2×(10 - Td + Tc); if not, the oil return mode is exited, and the current oil return duration, oil return speed, and interval time are applied to the current oil return mode. It should be noted that under the condition that the oil return mode is turned on, the air conditioner will only be in the heating mode, cooling mode, and dehumidification mode. Among them, the same formula is used for calculation in both the cooling mode and the dehumidification mode to obtain the oil return speed F2 of the current oil return mode. Therefore, it is only necessary to determine whether the current mode is the heating mode.

[0054] In some embodiments, after obtaining the current oil return speed F2 through the first logic or the second logic, the speed of the compressor 500 is controlled to increase to the current oil return speed F2 and continue to run for the oil return duration before exiting the oil return operation control.

[0055] In some embodiments, when the oil return mode ends, the current oil return speed F2 is the previous oil return speed F1 in the next oil return mode. Or, when the oil return mode starts, the current oil return speed F2 in the previous oil return mode is replaced with the previous oil return speed F1 before performing the operation of the first logic or the second logic.

[0056] Please refer toFigures 3 to 14 In some embodiments, the controller is configured to: if F2 is greater than the upper limit value of oil return, control the value of F2 to be the upper limit value of oil return; or if F2 is less than the lower limit value of oil return, control the value of F2 to be the lower limit value of oil return. Ensure that the oil return speed is within the range between the upper limit value and the lower limit value of oil return, and avoid the wear of the compressor 500 caused by too high or too low oil return speed and the impact of noise on users.

[0057] In some embodiments, the upper limit value of oil return is 40 rps, and the lower limit value of oil return is 30 rps. When the value of F2 is greater than 40, the oil return speed F2 of the current oil return mode is defaulted to 40 rps. If the value of F2 is less than 30, the oil return speed F2 of the current oil return mode is defaulted to 30 rps.

[0058] In some embodiments, the controller is configured to: if the number of times the oil return mode runs reaches the first preset number of times, and in these preset number of times, F2 is equal to the upper limit value of oil return or F2 is equal to the lower limit value of oil return, then start the first adjustment stage; Further, the controller is configured to: judge whether the number of times that the current oil return speed F2 is equal to the upper limit value of oil return in the first preset number of times reaches the first preset number of times during several consecutive oil return mode operations. If so, enter the first adjustment stage. If not, judge whether the number of times that the current oil return speed F2 is equal to the lower limit value of oil return in the first preset number of times reaches the first preset number of times. If so, enter the first adjustment stage; if not, operate in the current state normally and enter the oil return mode.

[0059] In another embodiment, the controller is configured to: judge whether the number of times that the current oil return speed F2 is equal to the lower limit value of oil return in the first preset number of times reaches the first preset number of times during several consecutive oil return mode operations. If so, enter the first adjustment stage; if not, judge whether the number of times that the current oil return speed F2 is equal to the upper limit value of oil return in the first preset number of times reaches the first preset number of times. If so, enter the first adjustment stage. If not, operate in the current state normally and enter the oil return mode.

[0060] Please refer to Figures 3 to 14 In some embodiments, the controller is configured to judge whether the current oil return speed F2 is equal to the upper limit value of oil return or the lower limit value of oil return. If not, continue to operate the oil return mode in the current state; if so, judge whether the number of times that the current oil return speed F2 is equal to the upper limit value of oil return or the lower limit value of oil return reaches the first preset number of times. If so, enter the first adjustment mode; if not, continue to operate the oil return mode in the current state.

[0061] In some embodiments, the controller is configured such that if the current oil return speed F2 is equal to the upper limit value or the lower limit value of the oil return, the number of times is recorded. If the number of times reaches the first preset number of times, the first adjustment stage is entered. If the current oil return speed F2 is not equal to the upper limit value or the lower limit value of the oil return, the number of times recorded is cleared.

[0062] Specifically, the controller is configured to determine whether the current oil return speed F2 is equal to the upper limit value or the lower limit value of the oil return. If not, the number of times recorded is cleared, and the oil return mode continues to operate in the current state. If so, one is added to the value of the number of times recorded, and it is determined whether the current number of times recorded reaches the first preset number of times. If so, the first adjustment stage is entered. If not, the oil return mode continues to operate in the current state.

[0063] In some embodiments, the first preset number of times is any value in the range of 3 to 5.

[0064] In some embodiments, the controller is configured as follows: Before the first adjustment stage: Calculate the temperature by subtracting the condensation temperature value from the compressor temperature value to obtain a temperature difference. If the temperature difference is greater than the first preset temperature difference and less than the second preset temperature difference, the first adjustment stage is not entered. If the temperature difference is less than the first preset temperature difference or greater than the second preset temperature difference, the first adjustment stage is entered.

[0065] Specifically, the controller is configured such that if the number of times the oil return mode runs reaches the first preset number of times, and in the first preset number of times the current oil return speed F2 is equal to the upper limit value or the lower limit value of the oil return, calculate the temperature by subtracting the condensation temperature value from the compressor temperature value to obtain a temperature difference, and determine whether the temperature difference is less than the first preset temperature difference. If so, the first adjustment stage is entered. If not, determine whether the temperature difference is greater than the second preset temperature difference. If so, the first adjustment stage is entered. If not, the first adjustment stage is not entered, the speed of the compressor 500 is controlled to increase to the current oil return speed F2, and after running continuously for the oil return duration, the oil return operation control is exited.

[0066] In the first adjustment stage: If it is determined that the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, the oil return duration in the current oil return mode is increased by the first time increment on the basis of the current oil return duration; if the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, the oil return duration in the current oil return mode is decreased by the first time decrement on the basis of the current oil return duration. When adjusting the oil return speed multiple times fails to achieve the desired effect, the oil return duration of the oil return mode is changed to make the oil return mode conform to the current scenario, thereby improving the reliability of the compressor 500. Since the extension or shortening of the oil return duration has a greater impact on the user than the oil return speed, in this application, the oil return speed is adjusted first. When the oil return speed cannot achieve the effect, the oil return duration is adjusted, minimizing the impact on the user and improving the user experience.

[0067] Further, in the first adjustment stage: If the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, the oil return duration in the current oil return mode is increased by the first time increment on the basis of the previous oil return duration. If the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, the oil return duration in the current oil return mode is decreased by the first time decrement on the basis of the previous oil return duration.

[0068] Furthermore, in the first adjustment stage: It is determined whether the temperature difference is less than the first preset temperature difference. If so, the oil return duration in the current oil return mode is increased by the first time increment on the basis of the previous oil return duration; if not, the oil return duration in the current oil return mode is decreased by the first time decrement on the basis of the previous oil return duration. Since it has been confirmed that there are only two situations for the temperature difference, i.e., less than the first preset temperature difference or greater than the second preset temperature difference, when entering the first adjustment stage, if it is determined that the temperature difference is less than the first preset temperature difference, it can be directly determined that the temperature difference is greater than the second preset temperature difference.

[0069] In another embodiment, in the first adjustment stage: It is determined whether the temperature difference is greater than the second preset temperature difference. If not, the oil return duration in the current oil return mode is increased by the first time increment on the basis of the previous oil return duration; if so, the oil return duration in the current oil return mode is decreased by the first time decrement on the basis of the previous oil return duration.

[0070] In some embodiments, both the first time increment and the first time decrement are half a minute, i.e., 0.5 min.

[0071] Please refer to Figures 3 to 14, in some embodiments, the oil return duration has an upper limit value and a lower limit value, which are the duration upper limit value and the duration lower limit value respectively. If the finally calculated oil return duration is lower than the duration lower limit value, the oil return duration is replaced with the duration lower limit value; if the finally calculated oil return duration is higher than the duration upper limit value, the oil return duration is replaced with the duration upper limit value.

[0072] Further, the range of the oil return duration is 1 to 3 minutes, that is, the upper limit of the duration is 3 minutes and the lower limit value of the duration is 1 minute. If the finally calculated oil return duration is lower than 1 minute, the oil return duration of the current oil return mode is 1 minute; if the finally calculated oil return duration is higher than 3 minutes, the oil return duration of the current oil return mode is 3 minutes.

[0073] In some embodiments, the controller is configured to: if the first adjustment stage runs continuously for a second preset number of times, start the second adjustment stage. Further, the controller is configured to: if it is determined that the first adjustment stage has entered in each of the second preset number of consecutive oil return modes, enter the second adjustment stage.

[0074] In some embodiments, the controller is configured to: before the second adjustment stage, calculate the temperature obtained by subtracting the condensing temperature value from the compressor temperature value to obtain a temperature difference. If the temperature difference is greater than the first preset temperature difference and less than the second preset temperature difference, do not enter the second adjustment stage. If the temperature difference is less than the first preset temperature difference or greater than the second preset temperature difference, enter the second adjustment stage.

[0075] Specifically, the controller is configured to: if the number of runs of the first adjustment stage reaches the second preset number, calculate the temperature obtained by subtracting the condensing temperature value from the compressor temperature value to obtain a temperature difference, and determine whether the temperature difference is less than the first preset temperature difference. If so, enter the second adjustment stage; if not, determine whether the temperature difference is greater than the second preset temperature difference. If so, enter the second adjustment stage; if not, do not enter the second adjustment stage, and apply the oil return duration calculated in the first adjustment stage.

[0076] Please refer to Figures 3 to 14, in some embodiments, during the second adjustment stage; if it is determined that the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, the interval time until the next oil return mode operation is subtracted by a second time difference based on the current interval time; if the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, the interval time until the next oil return mode operation is increased by a second time increment based on the current interval time. When the oil return duration cannot achieve the desired effect after multiple adjustments, the interval time of the oil return mode is changed to make the oil return mode conform to the current scenario and improve the reliability of the compressor 500. Since the extension or shortening of the interval time of the oil return mode has a greater impact on the user than the oil return duration, in this application, the oil return speed is adjusted first. When the oil return speed cannot achieve the effect, the oil return duration is adjusted. When the oil return duration also cannot achieve the effect, finally, the interval time of the oil return mode, which has the greatest impact on the user, is adjusted, minimizing the impact on the user and improving the user experience. It should be noted that the interval time is the time from the end of the current oil return mode to the start of the next oil return mode.

[0077] In some embodiments, the controller is configured to: if entering the first adjustment stage, record the number of times. If the number of times reaches the second preset number of times, enter the second adjustment stage. If not entering the first adjustment stage, clear the recorded number of times.

[0078] Specifically, the controller is configured to determine whether it has entered the first adjustment stage currently. If not, clear the recorded number of times and continue to operate the oil return mode in the current state; if so, add one to the value of the recorded number of times and determine whether the current recorded number of times reaches the second preset number of times. If so, enter the second adjustment stage; if not, continue to operate the oil return mode in the current state.

[0079] Furthermore, during the second adjustment stage: determine whether the temperature difference is less than the first preset temperature difference. If so, the interval time in the next oil return mode is increased by a second time increment based on the current interval time; if not, the interval time in the next oil return mode is subtracted by a second time decrement based on the current interval time. Since it has been confirmed that there are only two cases for the temperature difference, less than the first preset temperature difference or greater than the second preset temperature difference, when entering the first adjustment stage, if it is determined that the temperature difference is greater than the first preset temperature difference, it can be directly determined that the temperature difference is greater than the second preset temperature difference.

[0080] In another embodiment, during the second adjustment stage: determine whether the temperature difference is greater than the second preset temperature difference. If not, the interval time in the next oil return mode is increased by a second time increment based on the current interval time; if so, the interval time in the next oil return mode is subtracted by a second time decrement based on the current interval time.

[0081] In some embodiments, both the second time increment and the second time decrement are 5 minutes, i.e., 5 min.

[0082] In some embodiments, the interval time has an upper limit value and a lower limit value, which are the interval time upper limit value and the interval time upper limit value respectively. If the finally calculated interval time is lower than the interval time lower limit value, the interval time is replaced with the interval time lower limit value; if the finally calculated interval time is higher than the interval time upper limit value, the interval time is replaced with the duration upper limit value.

[0083] Further, the range of the interval time is 0.5 to 1 hour, that is, the upper limit of the interval time is 1 hour and the lower limit value of the interval time is 30 minutes. If the finally calculated interval time is less than 30 minutes, the interval time until the next oil return mode is 30 minutes; if the finally calculated interval time is higher than 1 hour, the interval time until the next oil return mode is 1 hour.

[0084] In some embodiments, in the second adjustment stage: when the compressor temperature value minus the condensation temperature value is less than the first preset temperature difference, the interval time until the next oil return mode is increased by the second time increment on the basis of the current interval time. When the compressor temperature value minus the condensation temperature value is greater than the second preset temperature difference, the interval time until the next oil return mode is decreased by the second time decrement on the basis of the current interval time.

[0085] In some embodiments, an indoor fan is provided inside the indoor unit 100; the controller is configured to: after entering the oil return mode, reduce the rotational speed of the indoor fan so that the coil temperature of the indoor heat exchanger 300 is within a preset range. Through this solution, the evaporation pressure is reduced in the cooling mode, and the condensation pressure is increased in the heating mode, so as to reduce the heat dissipation inside the compressor 500 or increase the heat generation inside the compressor 500, increase the internal temperature of the compressor 500, and at the same time, the indoor heat exchange amount can be reduced, and the probability of the indoor unit stopping when reaching the set temperature can be reduced, thereby improving the user experience.

[0086] In some embodiments, an outdoor fan is provided inside the outdoor unit 200; the controller is configured to: after entering the oil return mode, reduce the rotational speed of the outdoor fan. Increase the condensation pressure or reduce the evaporation pressure, so as to reduce the heat dissipation inside the compressor 500 or increase the heat generation inside the compressor 500, increase the internal temperature of the compressor 500, and at the same time, the indoor heat exchange amount can be reduced, and the probability of the indoor unit stopping when reaching the set temperature can be reduced, thereby improving the user experience.

[0087] In some embodiments, the indoor unit 100 has an air outlet of the air conditioner, and a deflector is provided at the air outlet of the air conditioner; the controller is configured to: after entering the oil return mode, control the deflector to move to a preset position. This can prevent the air flow from blowing on the user, reduce the indoor air volume to reduce the heat exchange amount, so as to reduce the probability of the air conditioner stopping when reaching the set temperature, ensure the comfort of the user, and at the same time will reduce the evaporation temperature or increase the condensation temperature, reduce the heat dissipation amount of the compressor 500 or increase the heat generation amount of the compressor 500, and increase the internal temperature of the compressor 500.

[0088] In some embodiments, if the first adjustment stage is not entered, the current oil return speed F2 calculated by the first logic or the second logic is applied in the current oil return mode. If the first adjustment stage is entered, only the oil return duration calculated in the first adjustment stage is applied in the current oil return mode. If the second adjustment stage is entered, after calculating and obtaining the interval time, the interval time is applied after the current oil return mode ends.

[0089] In some embodiments, a four-way valve is provided between the indoor heat exchanger 300 and the outdoor heat exchanger 400, and the flow direction of the refrigerant is adjusted through the four-way valve to change the cooling mode or heating mode of the air conditioner.

[0090] Please refer to Figures 3 to 14 , in this application, the controller is configured to: determine whether the speed of the compressor 500 is lower than the preset speed. If not, it operates in the current state. If so, record the running time and determine whether the running time exceeds the interval time. If not, continue to record its running time. If so, enter the oil return mode.

[0091] Determine whether the current is the heating mode. If so, control the first temperature sensor to detect the temperature value of the indoor heat exchanger 300 to obtain the condensation temperature value. If not, control the second temperature sensor to detect the temperature value of the outdoor heat exchanger 400 to obtain the condensation temperature value. Control the top temperature sensor to obtain the compressor temperature value. Calculate the temperature obtained by subtracting the condensation temperature value from the compressor temperature value to obtain the temperature difference; Determine whether the temperature difference is less than the first preset temperature difference. If so, enter the first logic, and calculate the value of the current oil return speed F2 through F2 = F1 + 2×(5 - Td + Tc). If not, enter the second logic, through F2 = F1 - 2×(10 - Td + Tc).

[0092] Judge whether the temperature difference is less than the first preset temperature difference or greater than the second preset temperature difference during continuous operation for the first preset number of times. If not, apply the calculated current oil return speed F2 to the current oil return mode, control the speed of the compressor 500 to increase to the current oil return speed F2, and after continuously running for the oil return duration, exit the oil return operation control. If so, enter the first adjustment stage.

[0093] In the first adjustment stage, if the temperature difference is less than the first preset temperature difference, the oil return duration in the current oil return mode is increased by the first time increment based on the previous oil return duration. If the temperature difference is greater than the second preset temperature difference, the oil return duration in the current oil return mode is decreased by the first time decrement based on the previous oil return duration.

[0094] If it is calculated that the current oil return duration is lower than the lower limit value of the duration, the current oil return duration is replaced with the lower limit value of the duration; if it is calculated that the current oil return duration is higher than the upper limit value of the duration, the current oil return duration is replaced with the upper limit value of the duration.

[0095] Judge whether the continuous operation of the first adjustment stage reaches the second preset number of times. If not, the oil return duration in the first adjustment stage is applied to the current oil return mode. If not, enter the second adjustment stage.

[0096] In the second adjustment stage, if the temperature difference is less than the first preset temperature difference, the interval time until the next operation of the oil return mode is decreased by the second time decrement based on the current interval time. If the temperature difference is greater than the second preset temperature difference, the interval time until the next operation of the oil return mode is increased by the second time increment based on the current interval time.

[0097] If it is calculated that the interval time is lower than the lower limit value of the interval time, the interval time is replaced with the lower limit value of the interval time; if it is calculated that the interval time is higher than the upper limit value of the interval time, the interval time is replaced with the upper limit value of the duration.

[0098] After the oil return mode ends, the calculated interval time is applied.

[0099] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An air conditioner, characterized in that, It includes: An indoor unit; An indoor heat exchanger, which is arranged inside the indoor unit; An outdoor unit; An outdoor heat exchanger, which is arranged inside the outdoor unit and is connected to the indoor heat exchanger; A compressor, which is arranged inside the outdoor unit and is used to deliver refrigerant to the outdoor heat exchanger and the indoor heat exchanger; A top temperature sensor, which is used to detect the temperature at the top of the compressor and obtain a compressor temperature value; A controller, which is configured to: if the time when the rotational speed of the compressor is lower than a preset rotational speed exceeds an interval time, enter an oil return mode; in the oil return mode, control the top temperature sensor to obtain the compressor temperature value; if the difference between the compressor temperature value and the condensation temperature value is less than a first preset temperature difference, calculate an oil return rotational speed through a first logic calculation; if the difference between the compressor temperature value and the condensation temperature value is greater than a second preset temperature difference, calculate an oil return rotational speed through a second logic calculation; control the rotational speed of the compressor to be increased to the oil return rotational speed, and continue to operate for an oil return duration and then exit the oil return operation control.

2. An air conditioner, characterized in that, It includes: An indoor unit; An indoor heat exchanger, which is arranged inside the indoor unit; An outdoor unit; An outdoor heat exchanger, which is arranged inside the outdoor unit and is connected to the indoor heat exchanger; A compressor, which is arranged inside the outdoor unit and is used to deliver refrigerant to the outdoor heat exchanger and the indoor heat exchanger; An exhaust temperature sensor, which is used to detect the exhaust temperature of the compressor and obtain a compressor temperature value; A controller, which is configured to: if the time when the rotational speed of the compressor is lower than a preset rotational speed exceeds an interval time, enter an oil return mode; in the oil return mode, control the exhaust temperature sensor to obtain the compressor temperature value; if the difference between the compressor temperature value and the condensation temperature value is less than a first preset temperature difference, calculate an oil return rotational speed through a first logic calculation; if the difference between the compressor temperature value and the condensation temperature value is greater than a second preset temperature difference, calculate an oil return rotational speed through a second logic calculation; control the rotational speed of the compressor to be increased to the oil return rotational speed, and continue to operate for an oil return duration and then exit the oil return operation control.

3. The air conditioner according to claim 1 or 2, characterized in that, A first temperature sensor is arranged inside the indoor unit, and the first temperature sensor is used to detect the temperature of the indoor heat exchanger; a second temperature sensor is arranged inside the outdoor unit, and the second temperature sensor is used to detect the temperature of the outdoor heat exchanger; The controller is configured to: in the oil return mode, in the refrigeration mode, control the second temperature sensor to detect the temperature value of the outdoor heat exchanger to obtain a condensation temperature value; in the heating mode, control the first temperature sensor to detect the temperature value of the indoor heat exchanger to obtain a condensation temperature value.

4. The air conditioner according to claim 3, wherein The first logic is: F2 = F1 + 2×(5 - Td + Tc); The second logic is: F2 = F1 - 2×(10 - Td + Tc); Among them, F2 is the oil return speed of the current oil return mode; F1 is the oil return speed in the previous oil return mode; Td is the compressor temperature value; Tc is the condensation temperature value.

5. The air conditioner according to claim 4, characterized in that, The controller is configured to: if the F2 is greater than the upper limit value of oil return, control the value of the F2 to be the upper limit value of oil return; Or if F2 is less than the lower limit value of oil return, control the value of the F2 to be the lower limit value of oil return.

6. The air conditioner according to claim 5, characterized in that, The controller is configured to: if the number of times the oil return mode runs reaches the first preset number of times, and in these preset number of times, F2 is equal to the upper limit value of oil return or F2 is equal to the lower limit value of oil return, then start the first adjustment stage; In the first adjustment stage: if it is determined that the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, the oil return duration in the current oil return mode is increased by the first time increment on the basis of the current oil return duration; If the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, the oil return duration in the current oil return mode is decreased by the first time decrement on the basis of the current oil return duration.

7. The air conditioner according to claim 6, characterized in that The controller is configured to: if the first adjustment stage runs continuously for the second preset number of times; then start the second adjustment stage; In the second adjustment stage; if it is determined that the difference between the compressor temperature value and the condensation temperature value is less than the first preset temperature difference, the interval time until the next oil return mode operation is decreased by the second time difference on the basis of the current interval time; If the difference between the compressor temperature value and the condensation temperature value is greater than the second preset temperature difference, the interval time until the next oil return mode operation is increased by the second time increment on the basis of the current interval time.

8. The air conditioner according to claim 1 or 2, characterized in that An indoor fan is provided inside the indoor unit; The controller is configured to: after entering the oil return mode, reduce the speed of the indoor fan so that the temperature of the indoor heat exchanger coil is within a preset range.

9. The air conditioner according to claim 1 or 2, characterized in that, An outdoor fan is provided inside the outdoor unit; The controller is configured to: after entering the oil return mode, reduce the speed of the outdoor fan.

10. The air conditioner according to claim 1 or 2, characterized in that, The indoor unit has an air outlet of the air conditioner, and a wind deflector is provided at the air outlet of the air conditioner; The controller is configured to: after entering the oil return mode, control the wind deflector to move to a preset position.

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