Air conditioner and control method thereof

Abstract

The invention discloses an air conditioner and a control method thereof. The air conditioner comprises a machine shell, a refrigerant circulation loop, a refrigerating system, an outdoor heat exchanger, an indoor heat exchanger, a first electronic expansion valve, a water pan, a water pan heating branch, a first temperature sensor, a second temperature sensor, a humidity sensor and a controller. Wherein the water pan is arranged below the indoor heat exchanger and is used for collecting condensate water generated by the indoor heat exchanger; the controller is configured to determine that the air conditioner is in a refrigeration mode; the temperature of the bottom of the water pan, the temperature of the indoor environment and the humidity of the indoor environment are obtained; the current dew point temperature is determined according to the temperature of the indoor environment and the humidity of the indoor environment; the flow of the refrigerant flowing through the water pan heating branch is controlled according to the temperature of the bottom of the water pan and the current dew point temperature, so that the condensation phenomenon of the water pan is eradicated, the thickness of the water pan is effectively reduced, and the purpose of miniaturization of an indoor unit is achieved while refrigeration circulation of an air conditioner is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to an air conditioner and a control method thereof. Background Art

[0002] The basic structure of the existing indoor unit of the air conditioner is generally in the form of an evaporator on the top and a water tray on the bottom. The thickness of the indoor unit of the air conditioner is approximately equal to the sum of the height of the evaporator and the thickness of the water tray. The reason why the water tray needs to be made thicker is that the temperature of the condensed water is relatively low. If the low temperature extends the heat from the water tray to the bottom of the water tray, the bottom temperature will be too low. When the bottom temperature is lower than the dew point temperature, condensation water will be generated at the bottom of the water tray. The condensation water will flow out of the indoor unit from the sheet metal at the bottom of the water tray and cause condensation dripping in the indoor unit. Since the evaporator is the heat exchanger of the system, it cannot be arbitrarily thinned. Otherwise, the air conditioner energy efficiency cannot be achieved. Therefore, how to reduce the thickness of the water tray becomes the key to thinning the thickness of the indoor unit. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide an air conditioner and a control method thereof.

[0004] An air conditioner proposed by the present invention comprises: a casing; a refrigerant circulation circuit, which is arranged in the casing, so that the refrigerant circulates in a circuit composed of a compressor, a condenser, a first electronic expansion valve, an evaporator, and a four-way valve; a refrigeration system, which is arranged in the casing, and performs heat exchange between the refrigerant and the indoor air in the compression refrigeration cycle of the refrigerant circulation circuit, and the refrigeration system comprises the compressor, which is used to compress the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas and discharge it to the condenser; an outdoor heat exchanger and an indoor heat exchanger, which are arranged in the casing, wherein one works as the condenser and the other works as the evaporator; the first electronic expansion valve is arranged between the condenser and the evaporator, and the first electronic expansion valve is used to increase the flow resistance of the refrigerant passing through the first electronic expansion valve when the opening degree thereof is reduced, and to reduce the flow resistance of the refrigerant passing through the first electronic expansion valve when the opening degree thereof is increased; a water receiving tray, which is arranged at the indoor heat exchanger The bottom is used to collect condensed water generated by the indoor heat exchanger; a water receiving pan heating branch is arranged at the bottom of the water receiving pan, one end of the water receiving pan heating branch is connected to the outlet of the condenser, and the other end of the water receiving pan heating branch is connected to the inlet of the first electronic expansion valve, and the water receiving pan heating branch is used to divert the refrigerant flowing out of the condenser outlet to the water receiving pan to heat the bottom of the water receiving pan; a first temperature sensor is arranged at the bottom of the water receiving pan, and is used to obtain the temperature of the bottom of the water receiving pan; a second temperature sensor is used to obtain the temperature of the indoor environment; a humidity sensor is used to obtain the humidity of the indoor environment; the controller is configured to: determine that the air conditioner is in cooling mode; obtain the temperature of the bottom of the water receiving pan, the temperature of the indoor environment and the humidity of the indoor environment; determine the current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment; control the refrigerant flow rate flowing through the water receiving pan heating branch according to the temperature of the bottom of the water receiving pan and the current dew point temperature.

[0005] In addition, the air conditioner according to the embodiment of the present invention may also have the following additional technical features:

[0006] Furthermore, the water receiving pan heating branch includes: a water receiving pan heat exchanger, which is arranged at the bottom of the water receiving pan and is used to conduct heat of the refrigerant to heat the bottom of the water receiving pan; a second electronic expansion valve, which is arranged between the water receiving pan heat exchanger and the first electronic expansion valve, and the second electronic expansion valve is used to increase the flow resistance of the refrigerant passing through the second electronic expansion valve when the opening degree of the second electronic expansion valve is reduced, and reduce the flow resistance of the refrigerant passing through the second electronic expansion valve when the opening degree of the second electronic expansion valve is increased.

[0007] Furthermore, when controlling the refrigerant flow through the water receiving pan heating branch according to the temperature of the bottom of the water receiving pan and the current dew point temperature, the controller is configured to: control the opening of the second electronic expansion valve according to the temperature of the bottom of the water receiving pan and the current dew point temperature to control the refrigerant flow through the water receiving pan heating branch.

[0008] Furthermore, when controlling the opening of the second electronic expansion valve according to the temperature of the bottom of the water receiving pan and the current dew point temperature, the controller is configured as follows: when the temperature of the bottom of the water receiving pan exceeds the sum of the current dew point temperature and the correction temperature, controlling the opening of the second electronic expansion valve to decrease by a preset opening; when the temperature of the bottom of the water receiving pan does not exceed the difference between the current dew point temperature and the correction temperature, controlling the opening of the second electronic expansion valve to increase by the preset opening; when the temperature of the bottom of the water receiving pan exceeds the difference between the current dew point temperature and the correction temperature, and does not exceed the sum of the current dew point temperature and the correction temperature, controlling the opening of the second electronic expansion valve to remain unchanged.

[0009] Furthermore, the correction temperature is 3°C to 5°C.

[0010] Furthermore, the water pan heat exchanger includes a first pipeline and a second pipeline, the first pipeline is U-shaped and one side is open, the first pipeline is multiple and is spaced apart in the up and down directions, the second pipeline is U-shaped, the second pipeline is connected between two adjacent first pipelines and is located on the open side of the first pipeline, the end of the top first pipeline among the multiple first pipelines away from the second pipeline is an inlet, the end of the bottom first pipeline among the multiple first pipelines away from the second pipeline is an outlet, and the first temperature sensor is arranged at the end of the bottom first pipeline among the multiple first pipelines away from the second pipeline.

[0011] Furthermore, the water pan heat exchanger includes a third pipeline, and the third pipeline is multiple and is arranged at intervals in the up and down directions. The axial ends of the multiple third pipelines are interconnected to form an inlet, and the other axial ends of the multiple third pipelines are interconnected to form an outlet, and the first temperature sensor is arranged at the other axial end of the third pipeline at the top of the multiple third pipelines, or at the other axial end of the third pipeline at the bottom of the multiple third pipelines.

[0012] Furthermore, the refrigerant pipeline of the water receiving pan heat exchanger includes a fourth pipeline and a fifth pipeline, the fourth pipeline includes a first elbow and a second elbow, the first elbow is multiple and spaced apart from each other, the first elbow is U-shaped and one side is open, the second elbow is U-shaped and connected between two adjacent first elbows, the second elbow is located on the open side of the first elbow, and the end of the first elbow at the top of the multiple first elbows away from the second elbow is an inlet; the fifth pipeline includes a third elbow and a fourth elbow, the third elbow is located on the inner circle of the first elbow and spaced apart from the first elbow, the third elbow is multiple and corresponds to the first elbow one by one, the third elbow is U-shaped and open on the same side as the first elbow, the fourth elbow is U-shaped and connected between two adjacent third elbows, and the fourth elbow is located on the open side of the first elbow; the multiple third elbows One end of the third bend at the bottom of the tube away from the fourth bend is connected to one end of the first bend at the bottom of the plurality of first bends away from the second bend, one end of the third bend at the top of the plurality of third bends away from the fourth bend is an outlet, the bending radius of the first bend is equal to that of the second bend, the bending radius of the third bend is smaller than that of the first bend, and the bending radius of the fourth bend is larger than that of the second bend; the first temperature sensor is arranged on the unopened side of the first bend at the top of the plurality of first bends, or is arranged on the unopened side of the first bend at the bottom of the plurality of first bends, or is arranged at one end of the third bend at the bottom of the plurality of third bends away from the fourth bend, and is connected to one end of the first bend at the bottom of the plurality of first bends away from the second bend.

[0013] Furthermore, the controller is also configured to: determine that the air conditioner is in a heating mode; and control the second electronic expansion valve to close.

[0014] According to an embodiment of the present invention, the air conditioner includes: a casing, a refrigerant circulation loop, a refrigeration system, an outdoor heat exchanger, an indoor heat exchanger, a first electronic expansion valve, a water receiving pan, a water receiving pan heating branch, a first temperature sensor, a second temperature sensor, a humidity sensor and a controller. Among them, the refrigerant circulation loop is arranged in the casing, so that the refrigerant circulates in the loop composed of the compressor, condenser, first electronic expansion valve, evaporator, and four-way valve; the refrigeration system is arranged in the casing, and it performs heat exchange between the refrigerant and the indoor air in the compression refrigeration cycle of the refrigerant circulation loop, and the refrigeration system includes a compressor, which is used to compress the low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the outdoor heat exchanger and the indoor heat exchanger are arranged in the casing, one of which works as a condenser and the other works as an evaporator; the first electronic expansion valve is arranged between the condenser and the evaporator, and the first electronic expansion valve is used to increase the flow resistance of the refrigerant passing through the first electronic expansion valve when its opening is reduced, and reduce the flow resistance of the refrigerant passing through the first electronic expansion valve when its opening is increased; the water receiving pan is arranged below the indoor heat exchanger to collect condensed water generated by the indoor heat exchanger; the water receiving pan heating branch is arranged at the receiving At the bottom of the water pan, one end of the water pan heating branch is connected to the outlet of the condenser, and the other end of the water pan heating branch is connected to the inlet of the first electronic expansion valve. The water pan heating branch is used to divert the refrigerant flowing out of the condenser outlet to the water pan to heat the bottom of the water pan; the first temperature sensor is arranged at the bottom of the water pan to obtain the temperature of the bottom of the water pan; the second temperature sensor is used to obtain the temperature of the indoor environment; the humidity sensor is used to obtain the humidity of the indoor environment; the controller is configured to: determine whether the air conditioner is in cooling mode; obtain the temperature of the bottom of the water pan, the temperature of the indoor environment and the humidity of the indoor environment; determine the current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment; control the refrigerant flow rate flowing through the water pan heating branch according to the temperature of the bottom of the water pan and the current dew point temperature to prevent condensation from occurring in the water pan and effectively reduce the thickness of the water pan, thereby realizing the refrigeration cycle of the air conditioner while achieving the purpose of miniaturization of the indoor unit.

[0015] In response to the above-mentioned problems, the present invention also proposes a control method for an air conditioner, comprising: determining that the air conditioner is in cooling mode; obtaining the temperature of the bottom of the water receiving tray, the temperature of the indoor environment and the humidity of the indoor environment; determining the current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment; and controlling the refrigerant flow rate flowing through the water receiving tray heating branch according to the temperature of the bottom of the water receiving tray and the current dew point temperature.

[0016] According to the control method of the air conditioner of the embodiment of the present invention, it is determined that the air conditioner is in cooling mode; the temperature of the bottom of the water receiving pan, the temperature of the indoor environment and the humidity of the indoor environment are obtained; the current dew point temperature is determined according to the temperature of the indoor environment and the humidity of the indoor environment; the refrigerant flow rate flowing through the water receiving pan heating branch is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature to prevent condensation from occurring in the water receiving pan and effectively reduce the thickness of the water receiving pan, thereby realizing the refrigeration cycle of the air conditioner and achieving the purpose of miniaturization of the indoor unit.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a structural schematic diagram of an air conditioner according to an embodiment of the present invention;

[0020] Figure 2 is a structural schematic diagram of an air conditioner according to another embodiment of the present invention;

[0021] Figure 3 is a flow chart of controlling the opening of the second electronic expansion valve according to the temperature of the bottom of the water receiving pan and the current dew point temperature according to one embodiment of the present invention;

[0022] Figure 4 is a schematic structural diagram of a water tray heat exchanger according to an embodiment of the present invention;

[0023] Figure 5 is a schematic structural diagram of a water tray heat exchanger according to another embodiment of the present invention;

[0024] Figure 6 is a schematic structural diagram of a water tray heat exchanger according to yet another embodiment of the present invention;

[0025] Figure 7 is a flow chart of a controller configuration according to one embodiment of the present invention;

[0026] Figure 8 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship 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 cannot be understood as a limitation on the present invention.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The air conditioner of the present invention performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, a first electronic expansion valve and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the conditioned and heat-exchanged air.

[0032] The compressor compresses the refrigerant gas at high temperature and high pressure and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0033] The first electronic expansion valve expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the first electronic expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioner can adjust the temperature of the indoor space.

[0034] The outdoor unit of the air conditioner refers to a part of the refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and the first electronic expansion valve can be provided in the indoor unit or the outdoor unit. The outdoor unit of the air conditioner also includes an outdoor blower and an outdoor fan, wherein the outdoor blower is used to drive the outdoor fan to rotate, and the outdoor fan is used to drive the outdoor air to pass through the outdoor heat exchanger so that the refrigerant and the outdoor air are heat exchanged. The indoor unit of the air conditioner also includes an indoor blower and an indoor fan, wherein the indoor blower is used to drive the indoor fan to rotate, and the indoor fan is used to drive the indoor air to pass through the indoor heat exchanger so that the refrigerant and the indoor air are heat exchanged.

[0035] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner functions as a cooler in a cooling mode.

[0036] Reference below Figure 1-Figure 8 An air conditioner and a control method thereof according to an embodiment of the present invention are described.

[0037] Figure 1 FIG. 1 is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention. Figure 1As shown, an air conditioner 10 includes: a casing 11, a refrigerant circulation loop 12, a refrigeration system 13, an outdoor heat exchanger 14, an indoor heat exchanger 15, a first electronic expansion valve 16, a water receiving pan 17, a water receiving pan heating branch 18, a first temperature sensor 19, a second temperature sensor 20, a humidity sensor 21 and a controller 22. Among them, the refrigerant circulation loop 12 is arranged in the casing 11, so that the refrigerant circulates in the loop composed of the compressor, the condenser, the first electronic expansion valve 16, the evaporator, and the four-way valve; the refrigeration system 13 is arranged in the casing 11, and performs heat exchange between the refrigerant and the indoor air in the compression refrigeration cycle of the refrigerant circulation loop 12. The refrigeration system 13 includes a compressor, which is used to compress the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the outdoor heat exchanger 14 and the indoor heat exchanger 15 are arranged in the casing 11, wherein one works as a condenser and the other works as an evaporator; the first electronic expansion valve 16 is arranged between the condenser and the evaporator, and the first electronic expansion valve 16 is used to increase the flow resistance of the refrigerant passing through the first electronic expansion valve 16 when its opening is reduced, and reduce the flow resistance of the refrigerant passing through the first electronic expansion valve 16 when its opening is increased; the water receiving tray 17 is arranged below the indoor heat exchanger 15, and is used to collect The condensed water generated by the indoor heat exchanger 15 is collected; the water receiving pan heating branch 18 is arranged at the bottom of the water receiving pan 17, one end of the water receiving pan heating branch 18 is connected to the outlet of the condenser, and the other end of the water receiving pan heating branch 18 is connected to the inlet of the first electronic expansion valve 16. The water receiving pan heating branch 18 is used to divert the refrigerant flowing out of the condenser outlet to the water receiving pan 17 to heat the bottom of the water receiving pan 17; the first temperature sensor 19 is arranged at the bottom of the water receiving pan 17, and is used to obtain the temperature of the bottom of the water receiving pan 17; the second temperature sensor 20 is used to obtain the temperature of the indoor environment; the humidity sensor 21 is used to obtain the humidity of the indoor environment; the controller 22 is configured to: determine that the air conditioner is in cooling mode; obtain the temperature of the bottom of the water receiving pan 17, the temperature of the indoor environment and the humidity of the indoor environment; determine the current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment; control the refrigerant flow through the water receiving pan heating branch 18 according to the temperature of the bottom of the water receiving pan 17 and the current dew point temperature.

[0038] Specifically, when the air conditioner is in cooling mode, the first electronic expansion valve 16 is in an open state, acting as a throttling component of the entire refrigeration cycle. The embodiment of the present invention heats the bottom of the water receiving tray 17 by setting a water receiving tray heating branch 18, so that the temperature of the bottom of the water receiving tray 17 is greater than the dew point temperature, thereby avoiding the formation of condensation water at the bottom of the water receiving tray 17. In this way, the thickness of the water receiving tray 17 can be reduced while ensuring that the water receiving tray 17 does not produce condensation water.

[0039] Specifically, the water pan heating branch 18 can be drained from the compressor exhaust, or drained from the outlet end of the condenser to use the high-temperature refrigerant to heat the bottom of the water pan. However, if it is drained from the compressor exhaust, the refrigerant temperature is too high, which will cause most of the heat to flow into the room, making the indoor cooling effect worse. The outlet refrigerant temperature of the condenser is 40 to 50 degrees, which is more suitable for heating the water pan 17. Therefore, one end of the water pan heating branch 18 is connected to the outlet of the condenser, and the other end of the water pan heating branch 18 is connected to the inlet of the first electronic expansion valve 16. After the refrigerant comes out of the condenser, it becomes a medium-temperature saturated liquid, and a part of it flows into the water pan heating branch 18, absorbs the cold of the water pan 17, merges with the other part of the refrigerant, and then flows into the first electronic expansion valve 16, and then throttles, evaporates and flows back to the compressor. That is, the embodiment of the present invention diverts the refrigerant flowing out of the condenser outlet to the water receiving pan 17 through the water receiving pan heating branch 18, and controls the refrigerant flow rate flowing through the water receiving pan heating branch 18 according to the temperature of the bottom of the water receiving pan 17 and the current dew point temperature, heats the bottom of the water receiving pan 17 to prevent condensation in the water receiving pan 17, and effectively reduces the thickness of the water receiving pan 17, thereby realizing the refrigeration cycle of the air conditioner while achieving the purpose of miniaturization of the indoor unit.

[0040] It can be understood that the dew point temperature is the temperature at which water vapor in the air begins to condense into liquid water. After obtaining the indoor dry-bulb temperature and humidity through the second temperature sensor and the humidity sensor, the dew point temperature at this time can be calculated based on the dry-bulb temperature and humidity. This is a prior art and will not be elaborated here.

[0041] In one embodiment of the present invention, Figure 2 As shown, the water receiving pan heating branch 18 includes: a water receiving pan heat exchanger 6 and a second electronic expansion valve 7. The water receiving pan heat exchanger 6 is arranged at the bottom of the water receiving pan 17, and is used to conduct heat of the refrigerant to the bottom of the water receiving pan 17; the second electronic expansion valve 7 is arranged between the water receiving pan heat exchanger 6 and the first electronic expansion valve 16, and the second electronic expansion valve 7 is used to increase the flow resistance of the refrigerant passing through the second electronic expansion valve 7 when the opening degree of the second electronic expansion valve 7 is reduced, and reduce the flow resistance of the refrigerant passing through the second electronic expansion valve 7 when the opening degree of the second electronic expansion valve 7 is increased.

[0042] Specifically, the water pan heat exchanger 6 and the second electronic expansion valve 7 constitute a water pan heating branch, and the water pan heat exchanger 6 is located at the bottom of the water pan 17, and is used to conduct heat from the refrigerant flowing through the water pan heating branch 18 to heat the bottom of the water pan 17. When the air conditioner is in cooling mode, the second electronic expansion valve 7 is controlled to be in an open state, and the flow rate of the refrigerant flowing through the water pan heating branch is controlled by adjusting its opening to control the heating temperature of the bottom of the water pan 17, thereby preventing the temperature of the bottom of the water pan 17 from being lower than the dew point temperature and reducing the occurrence of condensation. Specifically, when the opening of the second electronic expansion valve 7 is reduced, the flow resistance of the refrigerant increases, the flow speed slows down, and the heat exchange effect of the water tray heat exchanger 6 is poor; when the opening is increased, the flow resistance of the refrigerant decreases, the flow speed speeds up, and the heat exchange effect of the water tray heat exchanger 6 is better, so that by controlling the opening of the second electronic expansion valve 7, the flow of the refrigerant can be accurately adjusted to achieve the regulation of the heating temperature of the bottom of the docking water tray 17. It can be understood that when the bottom of the docking water tray 17 is heated by the water tray heat exchanger 6, the coldness of the cooling water in the water tray 17 can be conducted to the water tray heat exchanger 6 through the water tray 17, so that the refrigerant is further supercooled, thereby improving the supercooling degree of the refrigerant and further increasing the refrigeration capacity of the air conditioner.

[0043] In one embodiment of the present invention, when controlling the refrigerant flow through the water receiving pan heating branch according to the temperature of the bottom of the water receiving pan and the current dew point temperature, the controller is configured to: control the opening of the second electronic expansion valve according to the temperature of the bottom of the water receiving pan and the current dew point temperature to control the refrigerant flow through the water receiving pan heating branch.

[0044] Specifically, if Figure 2 As shown, the temperature of the bottom of the water receiving tray 17 is measured by the first temperature sensor 19, and the first temperature sensor 19 is set at the position where the temperature of the water receiving tray 17 is the lowest. The temperature at this position is used as the temperature of the bottom of the entire water receiving tray 17. The opening of the second electronic expansion valve is controlled according to the temperature and the current dew point temperature, so that the temperature of the bottom of the water receiving tray 17 is greater than the dew point temperature to ensure that no condensation water is generated at the bottom of the water receiving tray 17. In this way, the thickness of the water receiving tray can be thinned while ensuring that the water receiving tray 17 does not generate condensation water.

[0045] In one embodiment of the present invention, Figure 3As shown, when the opening of the second electronic expansion valve is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature, the controller is configured as follows: when the temperature of the bottom of the water receiving pan exceeds the sum of the current dew point temperature and the correction temperature, the opening of the second electronic expansion valve is controlled to decrease by a preset opening; when the temperature of the bottom of the water receiving pan does not exceed the difference between the current dew point temperature and the correction temperature, the opening of the second electronic expansion valve is controlled to increase by a preset opening; when the temperature of the bottom of the water receiving pan exceeds the difference between the current dew point temperature and the correction temperature, and does not exceed the sum of the current dew point temperature and the correction temperature, the opening of the second electronic expansion valve is controlled to remain unchanged. Specifically, the correction temperature is 3°C to 5°C.

[0046] Specifically, when adjusting the opening of the second electronic expansion valve, the correction temperature can maintain a certain temperature difference between the bottom temperature of the water receiving pan and the current dew point temperature, so as to ensure that the frequent adjustment of the second electronic expansion valve is reduced under unstable environmental conditions, thereby improving the stability and efficiency of the system. In a specific embodiment, if the correction temperature is set too small, while ensuring that the temperature of the water receiving pan is always greater than the current dew point temperature, the opening of the second electronic expansion valve may be adjusted frequently, causing problems such as increased energy consumption and component wear; and if the correction temperature is set too large, the error in adjusting the bottom temperature of the water receiving pan will be large. Therefore, the correction temperature needs to be determined based on experiments to appropriately set the correction temperature, so as to reduce energy consumption and component wear while ensuring that the temperature of the water receiving pan is always greater than the current dew point temperature. Exemplarily, the correction temperature is 3°C to 5°C.

[0047] In a specific embodiment, as described above, the refrigerant flow rate through the water receiving pan heating branch is controlled by controlling the opening of the second electronic expansion valve to control the bottom temperature of the water receiving pan, thereby preventing the formation of condensation. When the temperature at the bottom of the water receiving pan exceeds the sum of the dew point temperature and the corrected temperature, it is considered that the temperature at the bottom of the water receiving pan is high and the possibility of condensation is small. At this time, the opening of the second electronic expansion valve is controlled to reduce the preset opening, and the refrigerant flow rate through the water receiving pan heating branch is reduced until the temperature at the bottom of the water receiving pan exceeds the difference between the current dew point temperature and the corrected temperature, and does not exceed the sum of the current dew point temperature and the corrected temperature. While ensuring that no condensation water is generated at the bottom of the water receiving pan, it prevents excessive heat from the high-temperature refrigerant from flowing into the indoor side, thereby deteriorating the indoor cooling effect. When the temperature at the bottom of the water receiving pan does not exceed the difference between the dew point temperature and the corrected temperature, it is considered that the temperature at the bottom of the water receiving pan is low and condensation is likely to form. The possibility is relatively high, and it is necessary to control the opening of the second electronic expansion valve to increase the preset opening, increase the refrigerant flow through the water receiving pan heating branch, until the temperature at the bottom of the water receiving pan exceeds the difference between the current dew point temperature and the corrected temperature, and does not exceed the sum of the current dew point temperature and the corrected temperature, to ensure that no condensation water is generated at the bottom of the water receiving pan; when the temperature at the bottom of the water receiving pan exceeds the difference between the dew point temperature and the corrected temperature, but does not exceed the sum of the dew point temperature and the corrected temperature, it is considered that the temperature at the bottom of the water receiving pan is still high and no condensation will form. Therefore, the opening of the second electronic expansion valve is maintained unchanged, and the refrigerant flow through the water receiving pan heating branch is maintained unchanged to maintain the temperature at the bottom of the water receiving pan within the safe range. Therefore, by adjusting the opening of the second electronic expansion valve according to the temperature at the bottom of the water receiving pan and the current dew point temperature, the refrigerant flow through the water receiving pan heating branch can be dynamically controlled, thereby controlling the temperature at the bottom of the water receiving pan, ensuring that no condensation occurs, and ensuring the normal operation of the air conditioner. It should be noted that the preset opening is the step size of each adjustment of the opening of the second electronic expansion valve, which can be set according to actual conditions. The smaller the preset opening, the finer the adjustment of the opening of the second electronic expansion valve. In a specific embodiment, the bottom temperature of the water receiving pan can be detected every t minutes, and the opening of the second electronic expansion valve can be controlled according to the bottom temperature of the water receiving pan and the current dew point temperature. For example, t is 60 to 120 seconds.

[0048] In one embodiment of the present invention, a water tray heat exchanger includes a first pipeline and a second pipeline, the first pipeline is U-shaped and one side is open, there are multiple first pipelines and they are spaced apart in the up and down directions, the second pipeline is U-shaped, the second pipeline is connected between two adjacent first pipelines and is located on the open side of the first pipeline, the end of the top first pipeline among the multiple first pipelines away from the second pipeline is an inlet, the end of the bottom first pipeline among the multiple first pipelines away from the second pipeline is an outlet, and the first temperature sensor is arranged at the end of the bottom first pipeline among the multiple first pipelines away from the second pipeline.

[0049] Specifically, the water tray heat exchanger is used to achieve heat exchange between the refrigerant and the bottom of the water tray, thereby controlling the temperature at the bottom of the water tray to ensure that condensation does not occur and to ensure the normal operation of the air conditioner. Figure 4 As shown, the first pipeline 100 of the water receiving pan heat exchanger is U-shaped, one side is open, and multiple pipelines are arranged at intervals in the vertical direction. The second pipeline 200 is also U-shaped, connected between two adjacent first pipelines 100, and located on the open side of the first pipeline 100. The end of the top first pipeline of the multiple first pipelines 100 away from the second pipeline 200 is used as the inlet, and the end of the bottom first pipeline of the multiple first pipelines 100 away from the second pipeline 200 is used as the outlet. This water receiving pan heat exchanger structure has one way in and out as a whole, and the refrigerant temperature is the lowest at the outlet position. Therefore, the first temperature sensor 19 is placed at the end of the bottom first pipeline of the multiple first pipelines 100 away from the second pipeline 200, and the temperature it monitors is used as the lowest temperature of the water receiving pan.

[0050] In one embodiment of the present invention, the water tray heat exchanger includes a third pipeline, and the third pipeline is multiple and is spaced apart in the up and down directions. One axial end of the multiple third pipelines is interconnected to form an inlet, and the other axial ends of the multiple third pipelines are interconnected to form an outlet. The first temperature sensor is arranged at the other axial end of the third pipeline at the top of the multiple third pipelines, or at the other axial end of the third pipeline at the bottom of the multiple third pipelines.

[0051] Specifically, if Figure 5 Another form of the water tray heat exchanger is shown, and the third pipelines 300 are arranged at intervals in the vertical direction. The axial ends of the plurality of third pipelines 300 are interconnected to form an inlet, and the other ends are interconnected to form an outlet. The first temperature sensor 19 is placed at the other axial end of the third pipeline at the top of the plurality of third pipelines 300, or at the other axial end of the third pipeline at the bottom of the plurality of third pipelines 300. In a specific embodiment, after the refrigerant enters from the inlet, it is evenly divided into multiple paths, and finally gathered together and flows out from the outlet. It should be noted that, the more the third pipelines 300 are, the less refrigerant will be allocated to each third pipeline 300, resulting in serious overcooling of the end of the third pipeline 300 and too low an outlet temperature; and the fewer the third pipelines 300 are, the more likely the refrigerant will flow out without sufficient heat exchange, and the temperature may be too low. Therefore, the embodiment of the present invention sets the number of third pipelines 300 to 3 to 5. At this time, the first temperature sensor 19 is arranged at the upper right corner or lower right corner of the outlet, where the temperature is the lowest, and the temperature it monitors is used as the lowest temperature of the water tray.

[0052] In one embodiment of the present invention, Figure 6The figure shows another form of a water pan heat exchanger, in which the refrigerant pipeline of the water pan heat exchanger includes a fourth pipeline and a fifth pipeline, the fourth pipeline includes a first elbow 401 and a second elbow 402, the first elbow 401 is multiple and arranged at intervals up and down, the first elbow 401 is U-shaped and one side is open, the second elbow 402 is U-shaped and connected between two adjacent first elbows 401, the second elbow 402 is located on the open side of the first elbow, and the top first elbow of the multiple first elbows 401 is far away The end away from the second elbow 402 is the inlet; the fifth pipeline includes a third elbow 403 and a fourth elbow 404, the third elbow 403 is located in the inner circle of the first elbow 401, and is spaced apart from the first elbow 401, there are multiple third elbows 403 and they correspond to the first elbows 401 one by one, the third elbow 403 is U-shaped and is open on the same side as the first elbow 401, the fourth elbow 404 is U-shaped and connected between two adjacent third elbows 403, the fourth elbow 404 is located in the first elbow 4 01; one end of the third bend at the bottom of the plurality of third bends 403 away from the fourth bend 404 is connected to one end of the first bend at the bottom of the plurality of first bends 401 away from the second bend 402, one end of the third bend at the top of the plurality of third bends 403 away from the fourth bend 404 is an outlet, the bending radius of the first bend 401 and the second bend 402 are equal, the bending radius of the third bend 403 is smaller than the bending radius of the first bend 401, and the bending radius of the fourth bend 404 is larger than the bending radius of the second bend 402; the first temperature sensor 19 is arranged on the unopened side of the first bend at the top of the plurality of first bends 401, or, is arranged on the unopened side of the first bend at the bottom of the plurality of first bends 401, or, is arranged at one end of the third bend at the bottom of the plurality of third bends 403 away from the fourth bend 404, and is connected to one end of the first bend at the bottom of the plurality of first bends 401 away from the second bend 402.

[0053] Specifically, if Figure 6 The water receiving pan heat exchanger shown can set the inlet and outlet of the refrigerant at similar positions. At this time, the refrigerant first goes through a large S-bend, and then goes through a small S-bend when returning. Since the inlet temperature is the highest and the outlet temperature is the lowest, the first bend pipe 401 with the highest temperature and the third bend pipe 403 with the lowest temperature are combined together, and the third bend pipe 403 is located in the inner circle of the first bend pipe 401. The water receiving pan heat exchanger of this structure makes the temperature of the water receiving pan most uniform, thereby achieving a uniform heat exchange effect. At this time, the first temperature sensor 19 can be placed in different positions, such as the side of the top end of the multiple first bend pipes 401 that is not open, or the side of the bottom end of the multiple first bend pipes 401 that is not open, or the bottom end of the multiple third bend pipes 403, which is connected to the bottom end of the multiple first bend pipes 401, and the temperature monitored is used as the lowest temperature of the water receiving pan.

[0054] In one embodiment of the present invention, Figure 7 As shown, the controller is further configured to: determine that the air conditioner is in a heating mode; and control the second electronic expansion valve to close.

[0055] Specifically, in the heating mode, in order to ensure the heating effect of the system, the second electronic expansion valve is controlled to be closed to improve the heating efficiency and make the heating mode more effective.

[0056] According to an embodiment of the present invention, the air conditioner includes a casing, a refrigerant circulation loop, a refrigeration system, an outdoor heat exchanger, an indoor heat exchanger, a first electronic expansion valve, a water receiving pan, a water receiving pan heating branch, a first temperature sensor, a second temperature sensor, a humidity sensor and a controller. Among them, the refrigerant circulation loop is arranged in the casing, so that the refrigerant circulates in the loop composed of the compressor, condenser, first electronic expansion valve, evaporator, and four-way valve; the refrigeration system is arranged in the casing, and it performs heat exchange between the refrigerant and the indoor air in the compression refrigeration cycle of the refrigerant circulation loop, and the refrigeration system includes a compressor, which is used to compress the low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the outdoor heat exchanger and the indoor heat exchanger are arranged in the casing, one of which works as a condenser and the other works as an evaporator; the first electronic expansion valve is arranged between the condenser and the evaporator, and the first electronic expansion valve is used to increase the flow resistance of the refrigerant passing through the first electronic expansion valve when its opening is reduced, and reduce the flow resistance of the refrigerant passing through the first electronic expansion valve when its opening is increased; the water receiving pan is arranged below the indoor heat exchanger to collect condensed water generated by the indoor heat exchanger; the water receiving pan heating branch is arranged at the receiving At the bottom of the water pan, one end of the water pan heating branch is connected to the outlet of the condenser, and the other end of the water pan heating branch is connected to the inlet of the first electronic expansion valve. The water pan heating branch is used to divert the refrigerant flowing out of the condenser outlet to the water pan to heat the bottom of the water pan; the first temperature sensor is arranged at the bottom of the water pan to obtain the temperature of the bottom of the water pan; the second temperature sensor is used to obtain the temperature of the indoor environment; the humidity sensor is used to obtain the humidity of the indoor environment; the controller is configured to: determine whether the air conditioner is in cooling mode, obtain the temperature of the bottom of the water pan, the temperature of the indoor environment and the humidity of the indoor environment, determine the current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment, control the refrigerant flow rate flowing through the water pan heating branch according to the temperature of the bottom of the water pan and the current dew point temperature, so as to prevent condensation from occurring in the water pan, and effectively reduce the thickness of the water pan, thereby realizing the refrigeration cycle of the air conditioner while achieving the purpose of miniaturization of the indoor unit.

[0057] A further embodiment of the present invention also discloses a method for controlling an air conditioner, such as Figure 8 As shown, the method comprises the following steps:

[0058] Step S1: Determine whether the air conditioner is in cooling mode.

[0059] Step S2: Obtain the temperature of the bottom of the water receiving tray, the temperature of the indoor environment, and the humidity of the indoor environment.

[0060] Step S3: Determine the current dew point temperature according to the temperature and humidity of the indoor environment.

[0061] Step S4: controlling the flow rate of the refrigerant flowing through the water receiving pan heating branch according to the temperature of the bottom of the water receiving pan and the current dew point temperature.

[0062] In one embodiment of the present invention, the water receiving pan heating branch includes: a water receiving pan heat exchanger, which is arranged at the bottom of the water receiving pan and is used to conduct heat from the refrigerant to heat the bottom of the water receiving pan; a second electronic expansion valve, which is arranged between the water receiving pan heat exchanger and the first electronic expansion valve, and the second electronic expansion valve is used to increase the flow resistance of the refrigerant passing through the second electronic expansion valve when the opening degree of the second electronic expansion valve is reduced, and reduce the flow resistance of the refrigerant passing through the second electronic expansion valve when the opening degree of the second electronic expansion valve is increased.

[0063] In one embodiment of the present invention, the refrigerant flow rate through the water receiving pan heating branch is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature, including: controlling the opening of the second electronic expansion valve according to the temperature of the bottom of the water receiving pan and the current dew point temperature to control the refrigerant flow rate through the water receiving pan heating branch.

[0064] In one embodiment of the present invention, when the opening of the second electronic expansion valve is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature, it includes: when the temperature of the bottom of the water receiving pan exceeds the sum of the current dew point temperature and the correction temperature, the opening of the second electronic expansion valve is controlled to decrease by a preset opening; when the temperature of the bottom of the water receiving pan does not exceed the difference between the current dew point temperature and the correction temperature, the opening of the second electronic expansion valve is controlled to increase by a preset opening; when the temperature of the bottom of the water receiving pan exceeds the difference between the current dew point temperature and the correction temperature, and does not exceed the sum of the current dew point temperature and the correction temperature, the opening of the second electronic expansion valve is controlled to remain unchanged.

[0065] In one embodiment of the present invention, the correction temperature is 3°C to 5°C.

[0066] In one embodiment of the present invention, a water tray heat exchanger includes a first pipeline and a second pipeline, the first pipeline is U-shaped and one side is open, there are multiple first pipelines and they are spaced apart in the up and down directions, the second pipeline is U-shaped, the second pipeline is connected between two adjacent first pipelines and is located on the open side of the first pipeline, the end of the top first pipeline among the multiple first pipelines away from the second pipeline is an inlet, the end of the bottom first pipeline among the multiple first pipelines away from the second pipeline is an outlet, and a temperature sensor is arranged at the end of the bottom first pipeline among the multiple first pipelines away from the second pipeline.

[0067] In one embodiment of the present invention, the water tray heat exchanger includes a third pipeline, and the third pipeline is multiple and is spaced apart in the up and down directions. One axial end of the multiple third pipelines is interconnected to form an inlet, and the other axial ends of the multiple third pipelines are interconnected to form an outlet. The temperature sensor is arranged at the other axial end of the third pipeline at the top of the multiple third pipelines, or at the other axial end of the third pipeline at the bottom of the multiple third pipelines.

[0068] In one embodiment of the present invention, the refrigerant pipeline of the water receiving pan heat exchanger includes a fourth pipeline and a fifth pipeline, the fourth pipeline includes a first elbow and a second elbow, there are multiple first elbows and they are spaced apart from each other, the first elbow is U-shaped and one side is open, the second elbow is U-shaped and connected between two adjacent first elbows, the second elbow is located on the open side of the first elbow, and the end of the topmost first elbow among the multiple first elbows away from the second elbow is an inlet; the fifth pipeline includes a third elbow and a fourth elbow, the third elbow is located on the inner circle of the first elbow and is spaced apart from the first elbow, there are multiple third elbows and they correspond one to one to the first elbow, the third elbow is U-shaped and is open on the same side as the first elbow, the fourth elbow is U-shaped and connected between two adjacent third elbows, and the fourth elbow is located on the open side of the first elbow ; An end of the third bend at the bottom of the plurality of third bends away from the fourth bend is connected to an end of the first bend at the bottom of the plurality of first bends away from the second bend, an end of the third bend at the top of the plurality of third bends away from the fourth bend is an outlet, the bending radius of the first bend is equal to that of the second bend, the bending radius of the third bend is smaller than that of the first bend, and the bending radius of the fourth bend is larger than that of the second bend; the temperature sensor is arranged on the unopened side of the first bend at the top of the plurality of first bends, or, is arranged on the unopened side of the first bend at the bottom of the plurality of first bends, or, is arranged at an end of the third bend at the bottom of the plurality of third bends away from the fourth bend, and is connected to an end of the first bend at the bottom of the plurality of first bends away from the second bend.

[0069] In one embodiment of the present invention, the method further includes: determining that the air conditioner is in a heating mode; and controlling the second electronic expansion valve to close.

[0070] It should be noted that when the embodiment of the present invention controls the air conditioner, its specific implementation method is similar to the specific implementation method of the air conditioner in the embodiment of the present invention. Please refer to the description of the method part for details. In order to reduce redundancy, it will not be repeated here.

[0071] According to the control method of the air conditioner of the embodiment of the present invention, by determining that the air conditioner is in cooling mode, the temperature of the bottom of the water receiving pan, the temperature of the indoor environment and the humidity of the indoor environment are obtained, and the current dew point temperature is determined according to the temperature of the indoor environment and the humidity of the indoor environment. The refrigerant flow rate flowing through the water receiving pan heating branch is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature to prevent condensation from occurring in the water receiving pan and effectively reduce the thickness of the water receiving pan, thereby realizing the refrigeration cycle of the air conditioner while achieving the purpose of miniaturization of the indoor unit.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0073] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that: include: chassis; A refrigerant circulation loop is arranged in the casing, so that the refrigerant circulates in a loop composed of a compressor, a condenser, a first electronic expansion valve, an evaporator, and a four-way valve; A refrigeration system is arranged in the casing, and performs heat exchange between the refrigerant and the indoor air in the compression refrigeration cycle of the refrigerant circulation loop. The refrigeration system includes the compressor, and the compressor is used to compress the low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharge it to the condenser; an outdoor heat exchanger and an indoor heat exchanger, disposed in the housing, wherein one works as the condenser and the other works as the evaporator; The first electronic expansion valve is disposed between the condenser and the evaporator, and is used to increase the flow resistance of the refrigerant passing through the first electronic expansion valve when the opening degree of the first electronic expansion valve decreases, and to reduce the flow resistance of the refrigerant passing through the first electronic expansion valve when the opening degree of the first electronic expansion valve increases; A water receiving tray is provided below the indoor heat exchanger and is used to collect condensed water generated by the indoor heat exchanger; a water receiving pan heating branch, arranged at the bottom of the water receiving pan, one end of the water receiving pan heating branch connected to the outlet of the condenser, the other end of the water receiving pan heating branch connected to the inlet of the first electronic expansion valve, the water receiving pan heating branch used to divert the refrigerant flowing out of the condenser outlet to the water receiving pan, so as to heat the bottom of the water receiving pan; A first temperature sensor is disposed at the bottom of the water receiving tray and is used to obtain the temperature of the bottom of the water receiving tray; A second temperature sensor is used to obtain the temperature of the indoor environment; Humidity sensor, used to obtain the humidity of the indoor environment; The controller is configured to: determine that the air conditioner is in a cooling mode; Acquiring the temperature of the bottom of the water receiving tray, the temperature of the indoor environment, and the humidity of the indoor environment; determining a current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment; The flow rate of the refrigerant flowing through the water receiving pan heating branch is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature.

2. The air conditioner according to claim 1, characterized in that: The water receiving pan heating branch circuit comprises: A water receiving pan heat exchanger is disposed at the bottom of the water receiving pan and is used to conduct heat of the refrigerant to heat the bottom of the water receiving pan; The second electronic expansion valve is arranged between the water receiving pan heat exchanger and the first electronic expansion valve. The second electronic expansion valve is used to increase the flow resistance of the refrigerant passing through the second electronic expansion valve when the opening degree of the second electronic expansion valve is reduced, and to reduce the flow resistance of the refrigerant passing through the second electronic expansion valve when the opening degree of the second electronic expansion valve is increased.

3. The air conditioner according to claim 2, characterized in that: When controlling the refrigerant flow through the water receiving pan heating branch according to the temperature of the bottom of the water receiving pan and the current dew point temperature, the controller is configured as follows: The opening of the second electronic expansion valve is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature to control the flow of the refrigerant flowing through the water receiving pan heating branch.

4. The air conditioner according to claim 3, characterized in that: When controlling the opening of the second electronic expansion valve according to the temperature of the bottom of the water receiving pan and the current dew point temperature, the controller is configured as follows: When the temperature of the bottom of the water receiving pan exceeds the sum of the current dew point temperature and the correction temperature, controlling the opening of the second electronic expansion valve to reduce a preset opening; When the temperature of the bottom of the water receiving pan does not exceed the difference between the current dew point temperature and the correction temperature, controlling the opening of the second electronic expansion valve to increase the preset opening; When the temperature of the bottom of the water receiving pan exceeds the difference between the current dew point temperature and the correction temperature, and does not exceed the sum of the current dew point temperature and the correction temperature, the opening degree of the second electronic expansion valve is controlled to remain unchanged.

5. The air conditioner according to claim 4, characterized in that: The correction temperature is 3°C to 5°C.

6. The air conditioner according to any one of claims 2 to 5, characterized in that: The water tray heat exchanger includes a first pipeline and a second pipeline, the first pipeline is U-shaped and one side is open, there are multiple first pipelines and they are spaced apart in the up and down directions, the second pipeline is U-shaped, the second pipeline is connected between two adjacent first pipelines and is located on the open side of the first pipeline, the end of the topmost first pipeline among the multiple first pipelines away from the second pipeline is an inlet, the end of the bottommost first pipeline among the multiple first pipelines away from the second pipeline is an outlet, and the first temperature sensor is arranged at the end of the bottommost first pipeline among the multiple first pipelines away from the second pipeline.

7. The air conditioner according to any one of claims 2 to 5, characterized in that: The water receiving pan heat exchanger includes a third pipeline, and the third pipeline is multiple and is arranged at intervals in the up and down directions. One axial end of the multiple third pipelines is interconnected to form an inlet, and the other axial ends of the multiple third pipelines are interconnected to form an outlet. The first temperature sensor is arranged at the other axial end of the third pipeline at the top of the multiple third pipelines, or at the other axial end of the third pipeline at the bottom of the multiple third pipelines.

8. The air conditioner according to any one of claims 2 to 5, characterized in that: The refrigerant pipeline of the water receiving pan heat exchanger includes a fourth pipeline and a fifth pipeline, the fourth pipeline includes a first elbow and a second elbow, the first elbow is multiple and arranged at intervals up and down, the first elbow is U-shaped and one side is open, the second elbow is U-shaped and connected between two adjacent first elbows, the second elbow is located on the open side of the first elbow, and the end of the uppermost first elbow of the multiple first elbows away from the second elbow is an inlet; The fifth pipeline includes a third elbow and a fourth elbow, the third elbow is located in the inner circle of the first elbow and is spaced apart from the first elbow, there are multiple third elbows and they correspond to the first elbows one by one, the third elbow is U-shaped and is open on the same side as the first elbow, the fourth elbow is U-shaped and is connected between two adjacent third elbows, and the fourth elbow is located on the open side of the first elbow; One end of the third bend at the bottom of the plurality of third bends away from the fourth bend is connected to one end of the first bend at the bottom of the plurality of first bends away from the second bend, one end of the third bend at the top of the plurality of third bends away from the fourth bend is an outlet, the first bend and the second bend have the same bending radius, the third bend has a smaller bending radius than the first bend, and the fourth bend has a larger bending radius than the second bend; The first temperature sensor is arranged on the unopened side of the topmost first bend among the plurality of first bends, or, is arranged on the unopened side of the bottommost first bend among the plurality of first bends, or, is arranged on an end of the bottommost third bend among the plurality of third bends away from the fourth bend, and is connected to an end of the bottommost first bend among the plurality of first bends away from the second bend.

9. The air conditioner according to any one of claims 2 to 5, characterized in that: The controller is also configured to: Make sure the air conditioner is in heating mode; The second electronic expansion valve is controlled to be closed.

10. A method for controlling an air conditioner, characterized in that: For the air conditioner according to any one of claims 1 to 9, the method comprises the following steps: Make sure the air conditioner is in cooling mode; Acquiring the temperature of the bottom of the water receiving tray, the temperature of the indoor environment, and the humidity of the indoor environment; determining a current dew point temperature according to the temperature of the indoor environment and the humidity of the indoor environment; The flow rate of the refrigerant flowing through the water receiving pan heating branch is controlled according to the temperature of the bottom of the water receiving pan and the current dew point temperature.

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