Air conditioner and defrosting method thereof

Abstract

The present invention discloses an air conditioner and a defrosting method thereof. First, the operating power of an outdoor fan at a set speed is detected and stored in a data storage device. Then, after defrosting, a set speed of the outdoor fan motor is set, and the power of the outdoor fan motor at the speed is calculated. The read power value is analyzed and compared with the power value stored in the data storage device, so as to obtain information on whether the defrosting achieves a preset effect. If the read power value exceeds a specific range of the stored power value, it is determined that frost on the outdoor fan cover affects the normal operation of the air conditioner heating, and the defrosting fails to achieve the expected effect. Then, a preset control method is entered to strengthen the defrosting process for the frosting problem of the fan cover, so that the defrosting effect finally reaches the expected effect.

Description

Technical Field

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

[0002] Existing defrosting methods for air conditioners in heating mode typically only address frost on the condenser. This involves heating the condenser to defrost it, while also installing an electric heater on the outdoor unit's chassis to de-ice the chassis. However, in areas with high humidity and temperatures around 0°C, water molecules in the air are converted to a solid state as they pass through the condenser, forming frost. This frost has a certain affinity for the condenser, while some is also blown toward the outdoor unit's fan cover by the fan airflow, condensing on the cover. When frost becomes severe enough, it blocks airflow through the condenser and fan cover, affecting heat exchange in the condenser and preventing outdoor heat from reaching the indoor space. However, the commonly used defrosting method of existing air conditioners cannot remove the frost on the outdoor unit fan cover. Once the air conditioner outdoor unit fan cover is indeed frosted and blocks the air outlet, when the air conditioner finishes defrosting and starts heating, the airflow generated by the outdoor fan cannot be discharged to the outside through the air outlet, resulting in insufficient heat exchange on the outdoor condenser. The air conditioner finds it difficult to absorb enough heat from the outdoor environment and transfer it to the indoor environment, resulting in poor heating effect of the air conditioner and the defrosting process will soon begin again, resulting in a very poor user experience. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide an air conditioner and a defrosting method thereof, which can effectively remove the frost layer on the fan cover of the outdoor unit and ensure the normal operation of the air conditioner.

[0004] To achieve the above object, an embodiment of the present invention provides an air conditioner, comprising:

[0005] An indoor unit, used to adjust the temperature and humidity of indoor air, wherein the indoor unit is provided with an indoor fan and an indoor fan motor;

[0006] An outdoor unit is connected to the indoor unit via a connection pipe, wherein the outdoor unit is provided with an outdoor fan, an outdoor fan motor, a compressor, an outdoor heat exchanger, and an outdoor pipe temperature sensor for detecting the coil temperature of the outdoor heat exchanger;

[0007] A controller is used to obtain a first operating power of the outdoor fan motor when the outdoor fan motor reaches a set speed when the air conditioner is in a heating operation mode; control the air conditioner to perform a first defrost operation when it detects that the coil temperature is lower than the first set temperature; obtain a second operating power of the outdoor fan motor when the outdoor fan motor reaches a set speed after the air conditioner returns to the original heating operation mode; when the power difference between the second operating power and the first operating power is not within a preset error range, perform a second defrost operation until the power difference is within the error range; wherein, in the first defrost operation, both the indoor fan motor and the outdoor fan motor stop running, and in the second defrost operation, both the indoor fan motor and the outdoor fan motor start running.

[0008] As an improvement to the above solution, the first defrosting operation includes:

[0009] controlling the indoor fan motor, the outdoor fan motor, and the compressor to stop running, and when the stoppage time reaches a preset first stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode;

[0010] When the defrost time reaches a preset defrost threshold time or the coil temperature reaches a preset second set temperature, the compressor is controlled to stop running; wherein the second set temperature is greater than the first set temperature.

[0011] As an improvement to the above solution, the second defrosting operation includes:

[0012] controlling the indoor fan motor, the outdoor fan motor, and the compressor to stop running, and when the stoppage time reaches a preset second stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode;

[0013] After the duration of entering the cooling mode reaches a preset cooling operation duration, starting the indoor fan motor and controlling the indoor fan motor to run in reverse, and controlling the speed of the indoor fan motor to a preset low speed;

[0014] When it is detected that the coil temperature reaches a preset third set temperature, the outdoor fan motor is started; wherein the third set temperature is greater than the first set temperature;

[0015] When the operation time of the outdoor fan motor reaches a preset motor operation time, the indoor fan motor, the outdoor fan motor and the compressor are controlled to stop running.

[0016] As an improvement to the above solution, the controller is further configured to:

[0017] After the first defrost operation is performed, the current defrost number is recorded as 1;

[0018] After each second defrost operation is completed, the current defrost number is recorded as n+1; where n is an integer greater than or equal to 1;

[0019] Then, the third set temperature satisfies the following formula:

[0020] Th=T0+n+1;

[0021] Wherein, Th is the third set temperature, and T0 is a preset temperature when the second defrosting operation is performed for the first time.

[0022] As an improvement to the above solution, the controller is further configured to:

[0023] After performing the first defrost operation or the second defrost operation, after waiting for a preset recovery time, controlling the compressor and the outdoor fan motor to start running;

[0024] After detecting that the evaporator temperature in the indoor heat exchanger has increased, the indoor fan motor is started to resume the heating operation mode.

[0025] As an improvement to the above solution, the air conditioner further comprises:

[0026] An outdoor motor driving module is provided on the outdoor unit and is used to drive the outdoor fan motor to operate;

[0027] A current sampling module is provided on the outdoor unit and is used to detect the current sampling signal of the outdoor motor drive module;

[0028] A current sampling module is provided on the outdoor unit and is used to detect a voltage sampling signal of the outdoor motor drive module;

[0029] Then, the controller is used to calculate the operating power of the outdoor fan according to the current sampling signal and the voltage sampling signal.

[0030] To achieve the above object, an embodiment of the present invention further provides an air conditioner defrosting method, comprising:

[0031] When the air conditioner is in a heating operation mode, obtaining a first operating power of the outdoor fan motor when the outdoor fan motor reaches a set speed;

[0032] When it is detected that the coil temperature of the outdoor heat exchanger is lower than a first set temperature, the air conditioner is controlled to perform a first defrosting operation;

[0033] After the air conditioner returns to the original heating operation mode, obtaining the second operating power of the outdoor fan motor when the set speed is reached;

[0034] When the power difference between the second operating power and the first operating power is not within a preset error range, a second defrost operation is performed until the power difference is within the error range; wherein, in the first defrost operation, both the indoor fan motor and the outdoor fan motor stop running, and in the second defrost operation, both the indoor fan motor and the outdoor fan motor start running.

[0035] As an improvement to the above solution, the first defrosting operation includes:

[0036] controlling the indoor fan motor, the outdoor fan motor, and the compressor to stop running, and when the stoppage time reaches a preset first stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode;

[0037] When the defrost time reaches a preset defrost threshold time or the coil temperature reaches a preset second set temperature, the compressor is controlled to stop running; wherein the second set temperature is greater than the first set temperature.

[0038] As an improvement to the above solution, the second defrosting operation includes:

[0039] controlling the indoor fan motor, the outdoor fan motor, and the compressor to stop running, and when the stoppage time reaches a preset second stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode;

[0040] After the duration of entering the cooling mode reaches a preset cooling operation duration, starting the indoor fan motor and controlling the indoor fan motor to run in reverse, and controlling the speed of the indoor fan motor to a preset low speed;

[0041] When it is detected that the coil temperature reaches a preset third set temperature, the outdoor fan motor is started; wherein the third set temperature is greater than the first set temperature;

[0042] When the operation time of the outdoor fan motor reaches a preset motor operation time, the indoor fan motor, the outdoor fan motor and the compressor are controlled to stop running.

[0043] As an improvement to the above solution, the method further includes:

[0044] After the first defrost operation is performed, the current defrost number is recorded as 1;

[0045] After each second defrost operation is completed, the current defrost number is recorded as n+1; where n is an integer greater than or equal to 1;

[0046] Then, the third set temperature satisfies the following formula:

[0047] Th=T0+n+1;

[0048] Wherein, Th is the third set temperature, and T0 is a preset temperature when the second defrosting operation is performed for the first time.

[0049] Compared with the prior art, the air conditioner and defrost method thereof disclosed in the embodiment of the present invention first detect the operating power of the outdoor fan at a set speed and store it in a data storage device. Then, after defrosting, the set speed of the outdoor fan motor is set, and the power of the outdoor fan motor at the speed is calculated. The read power value is analyzed and compared with the power value stored in the data storage device to obtain information on whether the defrosting has achieved a preset effect. If the read power value exceeds a specific range of the stored power value, it is determined that frost on the outdoor fan cover affects the normal operation of the air conditioner heating, and the defrosting fails to achieve the expected effect. Then, the preset control method is entered to strengthen the defrosting process for the frosting problem on the fan cover, so that the defrosting effect finally reaches the expected effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 1 is a schematic diagram of the external structure of an air conditioner provided by an embodiment of the present invention;

[0051] Figure 2 1 is a schematic diagram of the flow direction of the refrigerant when the air conditioner provided by an embodiment of the present invention is in a cooling operation mode;

[0052] Figure 3 1 is a schematic diagram of the flow direction of the refrigerant when the air conditioner provided by an embodiment of the present invention is in a heating operation mode;

[0053] Figure 4 This is a structural block diagram of an outdoor controller provided by an embodiment of the present invention;

[0054] Figure 5 This is a first working flow diagram of a controller in an air conditioner provided by an embodiment of the present invention;

[0055] Figure 6 is a second working flow diagram of the controller in the air conditioner provided by an embodiment of the present invention;

[0056] Figure 7 1 is a schematic diagram of the operation of the air conditioner according to an embodiment of the present invention when performing a first defrosting operation;

[0057] Figure 8 is a third working flow diagram of the controller in the air conditioner provided by an embodiment of the present invention;

[0058] Figure 91 is a schematic diagram of the operation of the air conditioner according to an embodiment of the present invention when performing a second defrosting operation;

[0059] Figure 10 is a fourth working flow diagram of the controller in the air conditioner provided by an embodiment of the present invention;

[0060] Figure 11 The present invention provides a flowchart of an air conditioner defrosting method.

[0061] Among them, 100, indoor unit; 200, outdoor unit; 101, indoor heat exchanger; 102, indoor fan; 103, indoor fan motor; 104, indoor controller; 201, outdoor heat exchanger; 202, outdoor pipe temperature sensor; 203, outdoor fan motor; 204, outdoor fan; 205, outdoor unit fan cover; 206, throttling device; 207, four-way valve; 208, compressor; 209, outdoor controller. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0063] In the description of this application, 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 accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply 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 this application.

[0064] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0065] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0066] See also Figure 1 , Figure 1 FIG2 is a schematic diagram of the structure of an air conditioner provided in an embodiment of the present invention. The air conditioner includes an indoor unit 100 and an outdoor unit 200. The indoor unit 100 is used to adjust the temperature and humidity of indoor air. The outdoor unit 200 is connected to the indoor unit 100 via an interconnecting pipe. The outdoor unit 200 is installed outdoors, while the indoor unit 100 is installed indoors.

[0067] See also Figure 2 The indoor unit 100 includes an indoor heat exchanger 101, an indoor fan 102, an indoor fan motor 103, an indoor controller 104, an indoor air inlet, and an indoor air outlet. The outdoor unit 200 includes an outdoor heat exchanger 201, an outdoor pipe temperature sensor 202, an outdoor fan motor 203, an outdoor fan 204, an outdoor fan cover 205, a throttling device 206, a four-way valve 207, a compressor 208, and an outdoor controller 209.

[0068] The controller described in this embodiment of the present invention includes an indoor controller 104 and an outdoor controller 209. The indoor controller 104 is responsible for controlling the operation of the indoor fan motor 103 and communicating with the outdoor controller 209. The indoor fan motor 103 drives the indoor fan 102 to rotate to generate airflow for heat exchange. The outdoor controller 209 detects information from the outdoor pipe temperature sensor and is responsible for controlling the operation of the compressor 208, the four-way valve 207, and the outdoor fan motor 203. The compressor 208, the four-way valve 207, the throttling device 206, and the outdoor heat exchanger 201 are connected by copper pipes and filled with refrigerant. The outdoor fan motor 203 drives the outdoor fan 204 to operate to generate airflow for heat exchange.

[0069] When the air conditioner is cooling, see Figure 2 , Figure 2This is a schematic diagram of the flow direction of the refrigerant when the air conditioner provided by an embodiment of the present invention is in the heating operation mode. The refrigerant first passes through the compressor 208 to become a high-pressure gas, and then flows into the outdoor heat exchanger 201 (condenser) through the four-way valve 207. The outdoor heat exchanger 201 condenses the high-pressure gas and releases heat to become a high-pressure liquid. The high-pressure liquid passes through the throttling device 206 and becomes a low-temperature, low-pressure liquid. It evaporates and absorbs heat through the indoor heat exchanger 101 (evaporator) to become a low-temperature, low-pressure gas, and finally returns to the compressor 208 through the four-way valve 207.

[0070] When the air conditioner is heating, see Figure 3 , Figure 3 This is a schematic diagram of the flow of the refrigerant when the air conditioner provided by an embodiment of the present invention is in a heating operation mode. At this time, the refrigerant is compressed by the compressor 208 and becomes a high-pressure gas. The high-pressure gas enters the four-way valve 207, and then enters the indoor and outdoor connecting pipes to reach the indoor unit. The heat is transferred to the indoor heat exchanger 101 (condenser). Through the operation of the indoor fan motor 103, the air flow enters from the air inlet of the indoor unit, passes through the indoor heat exchanger 101 (condenser), and the condenser releases heat. The air flow takes away the heat on the condenser and is blown out of the air outlet of the indoor unit, transferring the heat to the indoor environment, thereby increasing the indoor room temperature. After the refrigerant flows through the indoor heat exchanger 101 (condenser) for heat transfer, it returns to the outdoor unit through the indoor and outdoor connecting pipes and enters the outdoor unit throttling device 206. After the refrigerant pressure is reduced by the throttling device 206, the refrigerant temperature is further reduced, and its temperature is generally much lower than the outdoor ambient temperature; then, the refrigerant enters the outdoor heat exchanger 201 (evaporator), which reduces the temperature of the outdoor heat exchanger 201 (evaporator). Under the operation of the outdoor fan motor 203, the outdoor ambient air flow passes through the outdoor heat exchanger 201 (evaporator) and is blown out of the outdoor unit from the outdoor unit fan cover 205. The outdoor heat exchanger 201 (evaporator) absorbs heat in the air flow to increase the refrigerant temperature. Then, the refrigerant enters the four-way valve 207 and returns to the compressor 208 for compression. This cycle continues, thereby continuously absorbing heat from the outdoor environment and transferring it to the indoor unit.

[0071] For example, the refrigerant flows differently during cooling and heating. During cooling, it first flows through the outdoor heat exchanger, where the outdoor unit acts as a condenser and the indoor unit acts as an evaporator. During heating, the refrigerant first flows through the indoor heat exchanger, where the indoor unit acts as a condenser and the outdoor unit acts as an evaporator. The condenser releases heat, while the evaporator absorbs it. The air conditioner uses a four-way valve to change the refrigerant flow direction between cooling and heating modes. Without a four-way valve, the air conditioner can only operate in either cooling or heating mode, and cannot switch between cooling and heating modes.

[0072] See also Figure 4 , Figure 4: is a structural block diagram of an outdoor controller 209 provided in an embodiment of the present invention, wherein the outdoor controller includes a power rectifier module 21, a control chip power module 22, an outdoor motor drive module 23, a control chip 24, an energy storage capacitor C1, a current sampling module and a voltage sampling module; wherein,

[0073] The power rectifier module 21 is used to rectify the input AC power into DC power. The energy storage capacitor C1 mainly functions to store energy and smooth the rectified DC power. The outdoor motor driver module 23 receives commands from the control chip 24 and converts them into drive signals to control the start and stop of the outdoor fan motor 203 and its speed during operation. The control chip power module 22 converts the high-voltage DC power generated by the input power rectifier module into low-voltage DC power for the control chip 24, which is a 5V power supply in this embodiment. The current sampling module is mainly composed of resistors R0, R1, R2, R3 and an operational amplifier N1. It collects the current signal across R0 and amplifies it at a specific ratio set by R1, R2, and R3, and then inputs it into the operational amplifier N1. N1 then outputs the current sampling signal Ifan to the control chip 24 for control operations. The voltage sampling module mainly generates a voltage sampling signal Vfan by dividing the voltage by resistors R4 and R5, and inputs the voltage sampling signal Vfan to the control chip 24 for control operations.

[0074] When the air conditioner is in heating mode, the temperature of the outdoor heat exchanger 201 (evaporator) is often much lower than 0°C. This causes water molecules in the air to be converted into a solid state as they pass through the outdoor heat exchanger 201 (evaporator), forming frost. Frost has a certain adsorption force and adheres to the outdoor heat exchanger 201 (evaporator). At the same time, some of the frost is blown toward the outdoor fan cover 205 by the airflow from the outdoor fan 204, condensing on the outdoor fan cover 205. When the frost becomes severe enough, it will hinder the airflow through the outdoor heat exchanger 201 (evaporator) and the outdoor fan cover 205, affecting the heat exchange between the outdoor heat exchanger 201 (evaporator) and the outdoor fan cover 205, preventing the outdoor heat from being transferred indoors. Therefore, defrosting the outdoor fan cover 205 is necessary during heating operation.

[0075] The controller in the air conditioner is used to: when the air conditioner is in a heating operation mode, obtain the first operating power of the outdoor fan motor 203 when it reaches a set speed; when it is detected that the coil temperature is lower than the first set temperature, control the air conditioner to perform a first defrost operation; after the air conditioner returns to the original heating operation mode, obtain the second operating power of the outdoor fan motor 203 when it reaches a set speed; when the power difference between the second operating power and the first operating power is not within a preset error range, perform a second defrost operation until the power difference is within the error range; wherein, in the first defrost operation, both the indoor fan motor 103 and the outdoor fan motor 203 stop running, and in the second defrost operation, both the indoor fan motor 103 and the outdoor fan motor 203 start running.

[0076] For example, see Figure 5 , Figure 5 1 is a first working flow diagram of a controller in an air conditioner provided by an embodiment of the present invention, wherein the controller is configured to execute steps S11 to S19:

[0077] S11. Determine whether the air conditioner is in a heating operation mode. If so, proceed to step S12; otherwise, continue to execute step S11.

[0078] S12. When the air conditioner is in a heating operation mode, obtain the first operating power of the outdoor fan motor 203 when the outdoor fan motor 203 reaches a set speed, and then enter step S13.

[0079] For example, after the air conditioner receives the heating operation instruction, the outdoor controller sets the speed of the outdoor fan motor 203 during normal heating operation to R, and detects the fan motor drive module voltage sampling signal Vfan1 and the fan current sampling signal Ifan1 when R rotates, thereby calculating the first operating power Pfan1 of the outdoor fan motor 203 and storing it in the control chip.

[0080] S13: Determine whether the coil temperature is lower than a preset first set temperature. If so, proceed to step S14; if not, continue to execute step S13.

[0081] S14. When the coil temperature is lower than the first set temperature, the air conditioner is controlled to perform a first defrosting operation, and then enters step S15.

[0082] For example, during the heating operation, when it is detected that the outdoor coil temperature is lower than the first set temperature Ts (for example, -10°C), it is determined that the first defrost operation needs to be performed. At this time, the indoor fan motor 103 and the outdoor fan motor 203 are shut down, the indoor fan and the outdoor fan stop supplying air, the compressor stops running, and the four-way valve is powered off and stops working.

[0083] S15. After the first defrosting operation is completed, the air conditioner returns to the original heating operation mode. At this time, the second operating power of the outdoor fan motor 203 when the set speed is reached is obtained, and then the process enters step S16.

[0084] For example, in the normal heating operation mode, the outdoor controller controls the speed of the outdoor fan motor 203 to the target setting value R, and then detects the fan motor drive module voltage sampling signal Vfan2 and the fan current sampling signal Ifan2 at this time, thereby calculating the second operating power Pfan2 of the outdoor fan motor.

[0085] S16. Calculate the power difference between the first operating power and the second operating power, and determine whether the power difference is within a preset error range. If so, proceed to step S17; otherwise, proceed to step S18.

[0086] Exemplarily, the second operating power Pfan2 is compared with the first operating power Pfan1 previously stored in the control chip. If the power difference is within the comparison set range, it means that the defrosting effect has been achieved and the wind resistance has not increased. If the power difference exceeds the comparison set error range, it means that the defrosting effect has not been achieved, and there is frost on the outdoor unit fan cover, which increases the wind resistance and causes the fan motor power to increase.

[0087] S17: If the power difference is within the error range, it indicates that the ideal defrosting effect has been achieved and the heating operation mode is restored.

[0088] S18: If the power difference is not within the error range, perform the second defrost operation and then enter step S19.

[0089] S19. After the second defrosting operation is completed, continue to determine whether the power difference is within the error range. If so, resume the heating operation mode. If not, continue to execute steps S16 to S18 until the power difference is within the error range.

[0090] Specifically, the first defrost operation includes: controlling the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 to stop running, and when the stoppage time reaches a preset first stoppage time, starting the compressor 208 and keeping the indoor fan motor 103 and the outdoor fan motor 203 in a stopped state, and controlling the air conditioner to enter the cooling mode; when the defrost time reaches a preset defrost threshold time or the coil temperature reaches a preset second set temperature, controlling the compressor 208 to stop running; wherein, the second set temperature is greater than the first set temperature.

[0091] For example, see Figure 6 , Figure 64 is a second working flow chart of the controller in the air conditioner provided by an embodiment of the present invention, wherein the controller is configured to execute steps S141 to S45:

[0092] S141, control the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 to stop running, and then enter step S142.

[0093] S142: Determine whether the stop time reaches a preset first stop time. If so, proceed to step S143; otherwise, return to step S141.

[0094] S143. When the stop time reaches a preset first stop time, start the compressor 208 and keep the indoor fan motor 103 and the outdoor fan motor 203 in a stop state, control the air conditioner to enter a cooling mode, and then enter step S144.

[0095] S144. Determine whether the defrost time reaches the preset defrost threshold time or whether the coil temperature reaches the preset second set temperature. If either is satisfied, proceed to step S145; if neither is satisfied, return to step S144.

[0096] S145 , when the defrost duration reaches a preset defrost threshold duration or the coil temperature reaches a preset second set temperature, control the compressor 208 to stop running.

[0097] For example, after the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 are stopped, the stop time reaches the first stop time t1 (for example, 30S), and only the compressor 208 is started, but the indoor fan motor 103 and the outdoor fan motor 203 are not running at this time, and the four-way valve is also in the power-off state. The refrigerant flow direction can be referred to Figure 7 At this time, the air conditioner is equivalent to the cooling operation mode. The indoor unit becomes the evaporator and the outdoor unit becomes the condenser. The condenser contains high-temperature and high-pressure refrigerant, which melts the frost layer while releasing heat to the outside. In order to prevent the cold air from the indoor unit from blowing into the room, the outdoor fan 204 and the indoor fan 102 are both stopped and the damper is closed during defrosting. The refrigerant flows from the compressor → four-way valve → outdoor heat exchanger → throttling device → indoor and outdoor connecting pipes → indoor heat exchanger → indoor and outdoor connecting pipes → four-way valve → compressor. At this time, the outdoor heat exchanger is heated to above 0°C due to the heating of the refrigerant, and the frost begins to melt and flow away into water. When the control chip calculates that the defrost time reaches the defrost threshold time tn (for example, 10 minutes) or detects that the coil temperature reaches the second set temperature Tc (for example, 10°C), it determines that the defrost is completed and the compressor 208 stops running.

[0098] Specifically, the second defrost operation includes: controlling the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 to stop running, and when the stop running time reaches a preset second stop time, starting the compressor 208 and keeping the indoor fan motor 103 and the outdoor fan motor 203 in a stopped state, and controlling the air conditioner to enter the cooling mode; after the time of entering the cooling mode reaches a preset cooling running time, starting the indoor fan motor 103 and controlling the indoor fan motor 103 to run in reverse, and controlling the speed of the indoor fan motor 103 to a preset low speed; when it is detected that the coil temperature reaches a preset third set temperature, starting the outdoor fan motor 203; wherein the third set temperature is greater than the first set temperature; when the running time of the outdoor fan motor 203 reaches the preset motor running time, controlling the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 to stop running.

[0099] For example, see Figure 8 , Figure 8 is a third working flow diagram of the controller in the air conditioner provided by an embodiment of the present invention, wherein the controller is further configured to execute steps S181 to S189:

[0100] S181, control the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 to stop running, and then enter step S182.

[0101] S183: Determine whether the stop time reaches a preset second stop time. If so, proceed to step S183; otherwise, return to step S181.

[0102] S183. When the stop time reaches a preset second stop time, start the compressor 208 and keep the indoor fan motor 103 and the outdoor fan motor 203 in a stop state, control the air conditioner to enter the cooling mode, and then enter step S184.

[0103] S184: Determine whether the duration of entering the cooling mode reaches the preset cooling operation duration. If so, proceed to step S185; otherwise, return to step S184.

[0104] S185. When the duration of the cooling mode reaches the cooling operation duration, the indoor fan motor 103 is controlled to run in reverse, and the speed is set to a preset low speed, and then enters step S186.

[0105] S186: Check whether the coil temperature reaches the third set temperature. If so, proceed to step S187; if not, continue to execute step S186.

[0106] S187. When the coil temperature reaches the third set temperature, start the outdoor fan motor 203, and then enter step S188.

[0107] S188. Determine whether the operating time of the outdoor fan motor 203 reaches the preset motor operating time. If so, proceed to step S189; if not, continue to execute step S188.

[0108] S189. When the operation time of the outdoor fan motor 203 reaches a preset motor operation time, the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 are controlled to stop running.

[0109] For example, after the indoor fan motor 103, the outdoor fan motor 203 and the compressor 208 are stopped, the stop time reaches the second stop time t2 (for example, 30S), and only the compressor 208 is started, but the indoor fan motor 103 and the outdoor fan motor 203 are not running at this time, and the four-way valve is also in the power-off state. The refrigerant flow direction can be referred to Figure 9 At this time, the air conditioner is equivalent to the cooling operation mode. The indoor unit becomes the evaporator and the outdoor unit becomes the condenser. The condenser contains high-temperature and high-pressure refrigerant, which melts the frost layer while releasing heat to the outside. The refrigerant flows from the compressor → four-way valve → condenser → throttling device → indoor and outdoor pipes → evaporator → indoor and outdoor pipes → four-way valve → compressor. The air conditioning system switches to cooling mode. After the operation time in this state reaches the cooling operation time tm (for example, 3 minutes), the indoor fan motor 103 is started to reverse and rotate at the set speed. That is, the air flow is sucked in from the indoor unit outlet and blown out from the indoor unit inlet. To avoid affecting the user experience, the fan speed is generally low at this time (for example, controlled below 500 rpm). Because the operation of the indoor fan enhances the heat exchange effect, the outdoor coil temperature can rise to a higher value. When the third set temperature Th is reached (for example, 30°C), the outdoor fan motor 203 is started to blow the hot air that has passed through the outdoor heat exchanger onto the outdoor fan cover, causing the frost on the outdoor fan cover to melt. When the operation time of the outdoor fan motor 203 reaches the motor operation time tk (for example, 5 minutes), it is determined that defrosting is completed, the compressor 208 stops running, and the indoor fan motor 103 and the outdoor fan motor 203 stop running.

[0110] The controller is further configured to: after executing the first defrost operation, record the current defrost number as 1; after each execution of the second defrost operation, record the current defrost number as n+1; wherein n is an integer greater than or equal to 1; then, the third set temperature satisfies the following formula:

[0111] Th=T0+n+1;

[0112] Among them, Th is the third set temperature, T0 is the preset temperature when the second defrost operation is performed for the first time (for example, the initial value is 30°C), and Th no longer rises after reaching the upper limit value (for example, 40°C), and the temperature for starting the outdoor fan is continuously increased to achieve the best defrost effect.

[0113] The controller is also used to: after executing the first defrost operation or the second defrost operation, wait for a preset recovery time, and then control the compressor 208 and the outdoor fan motor 203 to start running; after detecting that the evaporator temperature in the indoor heat exchanger has risen, start the indoor fan motor 103 to restore the heating operation mode.

[0114] For example, see Figure 10 , Figure 10 4 is a fourth working flow diagram of the controller in the air conditioner provided by an embodiment of the present invention. After executing step S14, the controller is further configured to execute steps S151 to S153:

[0115] S151. After executing the first defrost operation, wait for a preset recovery time (such as 30 seconds), control the compressor 208 and the outdoor fan motor 203 to start running, and then enter step S152.

[0116] S152. Determine whether the evaporator temperature in the indoor heat exchanger has increased. If so, proceed to step S153; otherwise, return to step S152.

[0117] S153: After detecting that the evaporator temperature in the indoor heat exchanger has increased, start the indoor fan motor 103 to restore the heating operation mode.

[0118] After executing step S18, the controller is further configured to execute steps S191 to S193:

[0119] S191. After executing the second defrosting operation, wait for a preset recovery time (such as 30 seconds), control the compressor 208 and the outdoor fan motor 203 to start running, and then enter step S192.

[0120] S192. Determine whether the evaporator temperature in the indoor heat exchanger has increased. If so, proceed to step S193; otherwise, return to step S192.

[0121] S193: After detecting that the evaporator temperature in the indoor heat exchanger has increased, start the indoor fan motor 103 to restore the heating operation mode.

[0122] Compared with the prior art, the air conditioner disclosed in the embodiment of the present invention first detects the operating power of the outdoor fan at a set speed and stores it in a data storage device. Then, after defrosting, the set speed of the outdoor fan motor 203 is set, and the power of the outdoor fan motor at the speed is calculated. The read power value is analyzed and compared with the power value stored in the data storage device to obtain information on whether the defrosting has achieved a preset effect. If the read power value exceeds a specific range of the stored power value, it is determined that frost on the outdoor fan cover affects the normal operation of the air conditioning heating, and the defrosting fails to achieve the expected effect. The preset control method is then entered to strengthen the defrosting process for the frosting problem on the fan cover, so that the defrosting effect ultimately achieves the expected effect.

[0123] See also Figure 11 , Figure 11 1 is a flow chart of an air conditioner defrosting method provided by an embodiment of the present invention, the air conditioner defrosting method comprising:

[0124] S1. When the air conditioner is in a heating operation mode, obtaining a first operating power of the outdoor fan motor when the outdoor fan motor reaches a set speed;

[0125] S2, when it is detected that the coil temperature of the outdoor heat exchanger is lower than the first set temperature, controlling the air conditioner to perform a first defrost operation;

[0126] S3. After the air conditioner returns to the original heating operation mode, obtaining a second operating power of the outdoor fan motor when the motor reaches the set speed;

[0127] S4. When the power difference between the second operating power and the first operating power is not within a preset error range, perform a second defrost operation until the power difference is within the error range; wherein, in the first defrost operation, both the indoor fan motor and the outdoor fan motor stop running, and in the second defrost operation, both the indoor fan motor and the outdoor fan motor start running.

[0128] Specifically, the first defrost operation includes: controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running, and when the stoppage time reaches a preset first stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode; when the defrost time reaches a preset defrost threshold time or the coil temperature reaches a preset second set temperature, controlling the compressor to stop running; wherein, the second set temperature is greater than the first set temperature.

[0129] Specifically, the second defrost operation includes: controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running, and when the stop running time reaches a preset second stop running time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter the cooling mode; after the time of entering the cooling mode reaches a preset cooling running time, starting the indoor fan motor and controlling the indoor fan motor to run in reverse, and controlling the speed of the indoor fan motor to a preset low speed; when it is detected that the coil temperature reaches a preset third set temperature, starting the outdoor fan motor; wherein the third set temperature is greater than the first set temperature; when the running time of the outdoor fan motor reaches the preset motor running time, controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running.

[0130] Specifically, the method further includes: after executing the first defrost operation, recording the current defrost number as 1; after each execution of the second defrost operation, recording the current defrost number as n+1; wherein n is an integer greater than or equal to 1; then, the second set temperature satisfies the following formula:

[0131] Th=T0+n+1;

[0132] Here, Th is the second set temperature, and T0 is a preset temperature when the second defrosting operation is performed for the first time.

[0133] Specifically, the method also includes: after executing the first defrost operation or the second defrost operation, waiting for a preset recovery time, controlling the compressor and the outdoor fan motor to start running; after detecting that the evaporator temperature in the indoor heat exchanger has risen, starting the indoor fan motor to restore the heating operation mode.

[0134] It is worth noting that the working process of the air conditioner defrosting method described in the embodiment of the present invention can refer to the working process diagram of the controller in the air conditioner described in the above embodiment, and will not be repeated here.

[0135] Compared with the prior art, the air conditioner defrosting method disclosed in the embodiment of the present invention first detects the operating power of the outdoor fan at a set speed and stores it in a data storage device. Then, after defrosting, the set speed of the outdoor fan motor is set, and the power of the outdoor fan motor at the speed is calculated. The read power value is analyzed and compared with the power value stored in the data storage device to obtain information on whether the defrosting has achieved a preset effect. If the read power value exceeds the specific range of the stored power value, it is determined that frost on the outdoor fan cover affects the normal operation of the air conditioner heating, and the defrosting fails to achieve the expected effect. The preset control method is then entered to strengthen the defrosting process for the frosting problem on the fan cover, so that the defrosting effect ultimately achieves the expected effect.

[0136] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An air conditioner, characterized in that: include: An indoor unit, used to adjust the temperature and humidity of indoor air, wherein the indoor unit is provided with an indoor fan and an indoor fan motor; An outdoor unit is connected to the indoor unit via a connection pipe, wherein the outdoor unit is provided with an outdoor fan, an outdoor fan motor, a compressor, an outdoor heat exchanger, and an outdoor pipe temperature sensor for detecting the coil temperature of the outdoor heat exchanger; The controller is configured to, when the air conditioner is in a heating operation mode, obtain a first operating power of the outdoor fan motor when the outdoor fan motor reaches a set speed; when it is detected that the coil temperature is lower than the first set temperature, control the air conditioner to perform a first defrost operation; after the air conditioner returns to the original heating operation mode, obtain a second operating power of the outdoor fan motor when the outdoor fan motor reaches the set speed; when the power difference between the second operating power and the first operating power is not within a preset error range, perform a second defrost operation until the power difference is within the error range; wherein, in the first defrost operation, both the indoor fan motor and the outdoor fan motor are stopped, and in the second defrost operation, both the indoor fan motor and the outdoor fan motor are started; The first defrost operation includes: controlling the indoor fan motor, the outdoor fan motor, and the compressor to stop running; when the stoppage time reaches a preset first stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode; when the defrost time reaches a preset defrost threshold time or the coil temperature reaches a preset second set temperature, controlling the compressor to stop running; wherein the second set temperature is greater than the first set temperature; The second defrost operation includes: controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running, and when the stop running time reaches a preset second stop time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter the cooling mode; after the time of entering the cooling mode reaches a preset cooling running time, starting the indoor fan motor and controlling the indoor fan motor to run in reverse, and controlling the speed of the indoor fan motor to a preset low speed; when it is detected that the coil temperature reaches a preset third set temperature, starting the outdoor fan motor; wherein the third set temperature is greater than the first set temperature; when the running time of the outdoor fan motor reaches the preset motor running time, controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running.

2. The air conditioner according to claim 1, wherein The controller is also used to: After the first defrost operation is performed, the current defrost number is recorded as 1; After each second defrost operation is completed, the current defrost number is recorded as n+1; where n is an integer greater than or equal to 1; Then, the third set temperature satisfies the following formula: Th=T0+n+1; Wherein, Th is the third set temperature, and T0 is a preset temperature when the second defrosting operation is performed for the first time.

3. The air conditioner according to claim 1, wherein The controller is also used to: After performing the first defrost operation or the second defrost operation, after waiting for a preset recovery time, controlling the compressor and the outdoor fan motor to start running; After detecting that the evaporator temperature in the indoor heat exchanger has increased, the indoor fan motor is started to resume the heating operation mode.

4. The air conditioner according to claim 1, wherein The air conditioner further comprises: An outdoor motor drive module is provided on the outdoor unit and is used to drive the outdoor fan motor to operate; A current sampling module is provided on the outdoor unit and is used to detect the current sampling signal of the outdoor motor drive module; A current sampling module is provided on the outdoor unit and is used to detect a voltage sampling signal of the outdoor motor drive module; Then, the controller is used to calculate the operating power of the outdoor fan according to the current sampling signal and the voltage sampling signal.

5. A defrosting method for an air conditioner, characterized in that: include: When the air conditioner is in a heating operation mode, obtaining a first operating power of the outdoor fan motor when the outdoor fan motor reaches a set speed; When it is detected that the coil temperature of the outdoor heat exchanger is lower than a first set temperature, the air conditioner is controlled to perform a first defrosting operation; After the air conditioner returns to the original heating operation mode, obtaining the second operating power of the outdoor fan motor when the set speed is reached; When the power difference between the second operating power and the first operating power is not within a preset error range, performing a second defrost operation until the power difference is within the error range; wherein, in the first defrost operation, both the indoor fan motor and the outdoor fan motor are stopped, and in the second defrost operation, both the indoor fan motor and the outdoor fan motor are started; The first defrost operation includes: controlling the indoor fan motor, the outdoor fan motor, and the compressor to stop running, and when the stoppage time reaches a preset first stoppage time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter a cooling mode; controlling the compressor to stop running when the defrost time reaches a preset defrost threshold time or the coil temperature reaches a preset second set temperature; wherein the second set temperature is greater than the first set temperature; The second defrost operation includes: controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running, and when the stop running time reaches a preset second stop time, starting the compressor and keeping the indoor fan motor and the outdoor fan motor in a stopped state, and controlling the air conditioner to enter the cooling mode; after the time of entering the cooling mode reaches a preset cooling running time, starting the indoor fan motor and controlling the indoor fan motor to run in reverse, and controlling the speed of the indoor fan motor to a preset low speed; when it is detected that the coil temperature reaches a preset third set temperature, starting the outdoor fan motor; wherein the third set temperature is greater than the first set temperature; when the running time of the outdoor fan motor reaches the preset motor running time, controlling the indoor fan motor, the outdoor fan motor and the compressor to stop running.

6. The air conditioner defrosting method according to claim 5, wherein: The method further comprises: After the first defrost operation is performed, the current defrost number is recorded as 1; After each second defrost operation is completed, the current defrost number is recorded as n+1; where n is an integer greater than or equal to 1; Then, the third set temperature satisfies the following formula: Th=T0+n+1; Wherein, Th is the third set temperature, and T0 is a preset temperature when the second defrosting operation is performed for the first time.

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