An air conditioner and its control method

Abstract

The present invention discloses an air conditioner and its control method. When the air conditioner enters the cooling mode, when the outdoor ambient temperature is lower than or equal to a predetermined temperature value, the value of the indoor heat exchanger temperature sensor is detected at this time, judged, and different control logics are adopted under different values. By controlling the start and stop of the compressor, the start and stop of the outdoor fan, adjusting the refrigerant flow rate, and at the same time cooperating with the logic control such as adjusting the speed of the outdoor fan, and at the same time controlling the adjustment of the indoor fan speed, thereby adjusting the use efficiency of the air conditioner heat exchanger, further improving the working energy efficiency of the air conditioner, and adjusting the energy output of the air conditioner, so as to improve its use comfort, and further protect the air conditioner, avoiding water leakage or even icing of the air conditioner under extreme conditions.

Description

Technical Field

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

[0002] Currently, traditionally, most uses of air conditioners are set to operate in the cooling mode in a high-temperature environment and in the heating mode in a low-temperature environment. However, for some special requirements, the air conditioner needs to operate in the cooling mode under low-temperature conditions. When the air conditioner cools at low temperatures, due to the low outdoor ambient temperature, the air conditioner is prone to too low evaporation pressure when operating in such an ambient temperature, and the whole machine is in a low load. To protect the machine, the whole machine will frequently start and stop, affecting the service life and comfort of the air conditioner. In addition, in a low-temperature environment, the system of the air conditioner is in a low-load state and cannot reasonably adjust the heat exchange effect of the heat exchanger, resulting in the air outlet temperature of the air conditioner not being able to be maintained at a comfortable level, violating the principles of energy conservation and comfort. The user feels uncomfortable, and there is also a risk of water dripping or even icing on the indoor heat exchanger. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide an air conditioner and a control method thereof, which can effectively adjust the use efficiency of the heat exchanger of the air conditioner, thereby improving the working energy efficiency of the air conditioner, adjusting the energy output of the air conditioner, improving its use comfort, and further protecting the air conditioner to avoid water leakage or even icing of the air conditioner in extreme cases.

[0004] To achieve the above purpose, the embodiments of the present invention provide an air conditioner, including:

[0005] An indoor unit for adjusting the temperature and humidity of indoor air, and an indoor fan is provided in the indoor unit;

[0006] An outdoor unit connected to the indoor unit through a connecting pipe, and a compressor, an outdoor fan, and an electronic expansion valve are provided in the outdoor unit;

[0007] A controller for controlling the operation of the indoor fan, the compressor, and the outdoor fan when the air conditioner enters the cooling mode; obtaining the evaporator inlet temperature when detecting that the outdoor ambient temperature is lower than the ambient temperature threshold; obtaining the condenser outlet temperature when the evaporator inlet temperature is within a preset high-temperature range and lasts for a first time; calculating the temperature difference between the condenser outlet temperature and the target condensation temperature; when the temperature difference is greater than or equal to the temperature difference threshold, reducing the opening degree of the electronic expansion valve and reducing the rotation speed of the outdoor fan; when the temperature difference is less than the temperature threshold, reducing the opening degree of the electronic expansion valve, and adjusting the rotation speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve.

[0008] As an improvement of the above solution, the adjusting the rotation speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve includes:

[0009] Calculate the opening change value of the electronic expansion valve before and after adjusting the opening degree;

[0010] When the opening change value is greater than or equal to the opening threshold, reduce the rotational speed of the outdoor fan to the first rotational speed;

[0011] When the opening change value is less than the opening threshold, reduce the rotational speed of the outdoor fan to the second rotational speed; wherein, the first rotational speed is greater than the second rotational speed.

[0012] As an improvement of the above solution, when the temperature difference is greater than or equal to the temperature difference threshold, reducing the opening degree of the electronic expansion valve includes: reducing the opening degree of the electronic expansion valve according to a preset fixed adjustment value;

[0013] When the temperature difference is less than the temperature threshold, reducing the opening degree of the electronic expansion valve includes: calculating the product of the temperature difference and a preset expansion valve coefficient as the target adjustment value, and reducing the opening degree of the electronic expansion valve according to the target adjustment value.

[0014] As an improvement of the above solution, the controller is further configured to:

[0015] When the inlet temperature of the evaporator is within a preset medium temperature range and lasts for a first period of time, control the outdoor fan to stop working;

[0016] After the outdoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than a first high temperature threshold and lasts for a second period of time, control the outdoor fan to start.

[0017] As an improvement of the above solution, the controller is further configured to:

[0018] When the inlet temperature of the evaporator is within a preset low temperature range and lasts for a first period of time, control the compressor and the outdoor fan to stop working;

[0019] After the compressor and the outdoor fan stop working, when it is detected that the inlet temperature of the evaporator is greater than a second high temperature threshold and lasts for a second period of time, control the compressor and the outdoor fan to start.

[0020] As an improvement of the above solution, the controller is further configured to:

[0021] When the inlet temperature of the evaporator is within a preset ultra-high temperature range, control the compressor, the indoor fan, and the outdoor fan to operate at the current rotational speed, and keep the opening degree of the electronic expansion valve unchanged.

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

[0023] When the inlet temperature of the evaporator is within a preset low temperature range, control the indoor fan to stop working;

[0024] After the indoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than a second high temperature threshold and lasts for a second time, control the indoor fan to start.

[0025] As an improvement to the above solution, the controller is further configured to:

[0026] When the inlet temperature of the evaporator is within a preset medium temperature range or high temperature range, increase the rotational speed of the indoor fan;

[0027] After increasing the rotational speed of the indoor fan, control the indoor fan to run at the current rotational speed for a period of time and then return to the initial rotational speed.

[0028] To achieve the above object, an embodiment of the present invention further provides an air conditioner control method, including:

[0029] When the air conditioner enters the cooling mode, control the indoor fan, compressor, and outdoor fan to run;

[0030] When it is detected that the outdoor ambient temperature is lower than the ambient temperature threshold, obtain the inlet temperature of the evaporator;

[0031] When the inlet temperature of the evaporator is within a preset high temperature range and lasts for a first time, obtain the outlet temperature of the condenser;

[0032] Calculate the temperature difference between the outlet temperature of the condenser and the target condensation temperature;

[0033] When the temperature difference is greater than or equal to the temperature difference threshold, reduce the opening degree of the electronic expansion valve and lower the rotational speed of the outdoor fan; when the temperature difference is less than the temperature threshold, reduce the opening degree of the electronic expansion valve, and adjust the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve.

[0034] As an improvement to the above solution, the adjusting the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve includes:

[0035] Calculate the change value of the opening degree of the electronic expansion valve before and after adjusting the opening degree;

[0036] When the change value of the opening degree is greater than or equal to the opening degree threshold, reduce the rotational speed of the outdoor fan to the first rotational speed;

[0037] When the change value of the opening degree is less than the opening degree threshold, reduce the rotational speed of the outdoor fan to the second rotational speed; wherein, the first rotational speed is greater than the second rotational speed.

[0038] Compared with the prior art, for the air conditioner and its control method disclosed in the embodiments of the present invention, when the air conditioner enters the cooling mode, when the outdoor ambient temperature is lower than or equal to a predetermined temperature value, the value of the indoor heat exchanger temperature sensor is detected at this time, judged, and different control logics are adopted under different values. By controlling the start and stop of the compressor, the start and stop of the outdoor fan, adjusting the refrigerant flow rate, and at the same time cooperating with the logic control such as adjusting the speed of the outdoor fan, and at the same time controlling the adjustment of the indoor fan speed, the use efficiency of the air conditioner heat exchanger is adjusted, thereby improving the working energy efficiency of the air conditioner, and adjusting the energy output of the air conditioner, so that its use comfort is improved, and the air conditioner is further protected to avoid water leakage or even icing of the air conditioner in extreme cases. Description of the Drawings

[0039] Figure 1 is a schematic structural diagram of an air conditioner provided by an embodiment of the present invention;

[0040] Figure 2 is a schematic structural diagram of a refrigeration system in an air conditioner provided by an embodiment of the present invention;

[0041] Figure 3 is the first working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0042] Figure 4 is the second working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0043] Figure 5 is the third working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0044] Figure 6 is the fourth working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0045] Figure 7 is the fifth working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0046] Figure 8 is the sixth working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0047] Figure 9 is the seventh working flow chart of the controller in the air conditioner provided by an embodiment of the present invention;

[0048] Figure 10 is a flow chart of an air conditioner control method provided by an embodiment of the present invention.

[0049] Among them, 100 is the indoor unit; 200 is the outdoor unit; 11 is the compressor; 12 is the four-way valve; 13 is the outdoor heat exchanger; 14 is the expansion valve; 15 is the indoor heat exchanger; 16 is the indoor fan; 17 is the outdoor fan; 18 is the outdoor coil temperature sensor; 19 is the outdoor ambient temperature sensor; 20 is the indoor coil temperature sensor. Detailed implementation manner

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0052] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "plurality" is two or more.

[0053] In the description of the present application, 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 may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0054] See Figure 1 , Figure 1It is a schematic structural diagram of an air conditioner provided by an embodiment of the present invention. The air conditioner described in the embodiment of the present invention 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 through a connecting pipe. The outdoor unit 200 is installed outdoors, and the indoor unit 100 is installed indoors.

[0055] See Figure 2 , Figure 2 It is a schematic structural diagram of a refrigeration system in an air conditioner provided by an embodiment of the present invention. The air conditioner includes a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, an expansion valve 14, an indoor heat exchanger 15, an indoor fan 16, an outdoor fan 17, an outdoor coil temperature sensor 18, an outdoor ambient temperature sensor 19, and an indoor coil temperature sensor 20. Among them, the indoor heat exchanger 15, the indoor fan 16, and the indoor coil temperature sensor 20 are arranged on the indoor unit 100, and the compressor 11, the four-way valve 12, the outdoor heat exchanger 13, the expansion valve 14, the outdoor fan 17, the outdoor coil temperature sensor 18, and the outdoor ambient temperature sensor 19 are arranged on the outdoor unit.

[0056] The air conditioner described in the embodiment of the present invention includes a refrigeration mode and a heating mode. When the air conditioner is refrigerating, the refrigerant first passes through the compressor to become a high-pressure gas, then condenses and releases heat through the outdoor unit heat exchanger (condenser) to become a high-pressure liquid. The high-pressure liquid passes through the throttling device and becomes a low-temperature and low-pressure liquid. It evaporates and absorbs heat through the indoor unit heat exchanger (evaporator) to become a low-temperature and low-pressure gas, and finally returns to the compressor. When the air conditioner is heating, the refrigerant first passes through the compressor to become a high-pressure gas, and then first condenses and releases heat through the indoor unit heat exchanger (condenser) to become a high-pressure liquid. The high-pressure liquid passes through the expansion valve and becomes a low-temperature and low-pressure liquid. The low-temperature and low-pressure liquid evaporates and absorbs heat through the outdoor unit heat exchanger (evaporator) to become a low-temperature and low-pressure gas, and finally returns to the compressor. The outdoor coil temperature sensor 18 is used to detect the temperature of the outdoor heat exchanger 13 (for example, when the outdoor heat exchanger 13 is an evaporator, it is used to detect the inlet temperature of the evaporator), the outdoor ambient temperature sensor 19 is used to detect the outdoor ambient temperature, and the indoor coil temperature sensor 20 is used to detect the temperature of the indoor heat exchanger 15 (for example, when the indoor heat exchanger 15 is a condenser, it is used to detect the outlet temperature of the condenser).

[0057] Exemplarily, the refrigerant flow direction is different during refrigeration and heating. During refrigeration, the refrigerant first flows through the outdoor unit heat exchanger. At this time, the outdoor unit is the condenser and the indoor unit is the evaporator. During heating, the refrigerant first flows through the indoor unit heat exchanger. At this time, the indoor unit is the condenser and the outdoor unit is the evaporator. During different refrigeration and heating states, the air conditioner changes the refrigerant flow direction through the four-way valve. Without the four-way valve, the air conditioner can only achieve single refrigeration or heating and cannot switch between cooling and heating. In the present invention, the fresh air device is installed on the outdoor unit or the indoor unit to communicate with the indoor environment, so as to realize indoor fresh air supply.

[0058] It should be noted that, in the embodiment of the present invention, the low temperature range is: the inlet temperature Ti of the evaporator < the first target evaporation temperature Te1; the medium temperature range is: the first target evaporation temperature Te1 ≤ the inlet temperature Ti of the evaporator ≤ the second target evaporation temperature Te2; the high temperature range is: the second target evaporation temperature Te2 < the inlet temperature Ti of the evaporator ≤ the third target evaporation temperature Te3; the ultra-high temperature range is: the third target evaporation temperature Te3 < the inlet temperature Ti of the evaporator; where Te1 < Te2 < Te3. The first high temperature threshold Te5 is greater than the second high temperature threshold Te4. The first time td1 and the first time td2 are equal or not equal, which can be set by the user or preset by the system, and will not be specifically limited here. For example, Te1 is 0 °C, Te2 is 3 °C, Te3 is 10 °C, Te4 is 5 °C, Te5 is 8 °C, td1 is 1 min, and td2 is 3 min.

[0059] In the embodiment of the present invention, the controller in the air conditioner is used to: when the air conditioner enters the refrigeration mode, control the indoor fan, compressor and outdoor fan to operate; when it is detected that the outdoor ambient temperature is lower than the ambient temperature threshold, obtain the inlet temperature of the evaporator; when the inlet temperature of the evaporator is within the preset high temperature range and lasts for the first time, obtain the outlet temperature of the condenser; calculate the temperature difference between the outlet temperature of the condenser and the target condensation temperature; when the temperature difference is greater than or equal to the temperature difference threshold, reduce the opening of the electronic expansion valve and reduce the rotation speed of the outdoor fan; when the temperature difference is less than the temperature threshold, reduce the opening of the electronic expansion valve, and adjust the rotation speed of the outdoor fan according to the change in the opening of the electronic expansion valve.

[0060] Exemplarily, refer to Figure 3 , Figure 3 which is the first working flow chart of the controller in the air conditioner provided by the embodiment of the present invention. The controller is used to execute steps S11~S21:

[0061] S11. When the air conditioner enters the refrigeration mode, control the indoor fan, compressor and outdoor fan to operate, and then enter step S12.

[0062] S12. Detect whether the outdoor ambient temperature is lower than the ambient temperature threshold. If so, proceed to step S13; if not, continue to execute step S12.

[0063] S13. When the outdoor ambient temperature is lower than the ambient temperature threshold, obtain the inlet temperature of the evaporator, and then proceed to step S14.

[0064] Exemplarily, when the air conditioner enters the cooling mode, when the ambient temperature Tw detected by the outdoor ambient sensor is less than or equal to 15°C (ambient temperature threshold), enter the air conditioner logic judgment.

[0065] S14. Determine whether the inlet temperature of the evaporator is within the high-temperature range. If so, proceed to step S15; if not, execute the remaining control logic.

[0066] S15. When the inlet temperature of the evaporator is within the high-temperature range, determine whether the duration of the inlet temperature of the evaporator within the high-temperature range is greater than the first time. If so, proceed to step S16; if not, return to step S14.

[0067] S16. When the inlet temperature of the evaporator is within the preset high-temperature range and lasts for the first time, obtain the outlet temperature of the condenser, and calculate the temperature difference between the outlet temperature of the condenser and the target condensation temperature, and then proceed to step S17.

[0068] Exemplarily, if Te2 < Ti ≤ Te3 and lasts for td1, obtain the current outlet temperature of the condenser by detecting the value of the outdoor coil temperature sensor, and calculate the outlet temperature of the condenser To - the target condensation temperature Tc = Δt.

[0069] S17. Determine whether the temperature difference Δt is greater than or equal to the temperature difference threshold a. If so, proceed to step S18; if not, proceed to step S20.

[0070] S18. When the temperature difference is greater than or equal to the temperature difference threshold, reduce the opening degree of the electronic expansion valve, and then proceed to step S19.

[0071] S19. When the temperature difference is greater than or equal to the temperature difference threshold, reduce the rotational speed of the outdoor fan.

[0072] Exemplarily, when the temperature difference is greater than or equal to the temperature difference threshold, the step of reducing the opening degree of the electronic expansion valve includes: reducing the opening degree of the electronic expansion valve according to a preset fixed adjustment value. If the judgment result is that Δt is greater than or equal to a, the electronic expansion valve directly reduces by X steps (fixed adjustment value), and at the same time the outdoor fan directly reduces by Y1 revolutions. This can quickly reduce the current opening degree of the electronic expansion valve, rapidly reduce the system flow rate, thereby quickly increasing the current system condensation pressure, thereby increasing the condenser outlet temperature. At the same time, by reducing the rotational speed of the outdoor fan, the heat exchange capacity on the outside is reduced, thereby increasing the current system condensation pressure, and further increasing the condenser outlet temperature, and synchronously increasing the evaporator inlet temperature.

[0073] S20. When the temperature difference is less than the temperature threshold, reduce the opening degree of the electronic expansion valve, and then proceed to step S21.

[0074] S21. When the temperature difference is less than the temperature threshold, adjust the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve in step S20.

[0075] Exemplarily, when the temperature difference is less than the temperature threshold, the step of reducing the opening degree of the electronic expansion valve includes: calculating the product of the temperature difference and a preset expansion valve coefficient as the target adjustment value, and reducing the opening degree of the electronic expansion valve according to the target adjustment value. If the judgment result is that Δt is less than a, the opening degree of the electronic expansion valve is reduced by X = c * Δt, where c is the preset expansion valve coefficient, and the rotational speed of the outdoor fan is adjusted according to the change in the opening degree of the electronic expansion valve in step S20. By judging the magnitude of the temperature difference value Δt between the condenser outlet temperature and the target condensation temperature, if the temperature difference value Δt is less than a, it indicates that the current condenser outlet temperature is relatively low, and the opening degree of its electronic expansion valve and the rotational speed of the outdoor fan can be adjusted by a large margin, so as to more quickly increase the current system condensation pressure, thereby increasing the condenser outlet temperature by a large margin, which is beneficial to increasing the evaporator inlet temperature. After adjusting the opening degree of the electronic expansion valve and the outdoor fan, it is necessary to maintain the current valve opening degree and the rotational speed of the outdoor fan for a period of time td1 and then re-enter the above condition judgment, so as to avoid the system being unable to respond due to the rapid change of the valve opening degree and the rotational speed of the outdoor fan, resulting in the system being in a fluctuating state all the time.

[0076] Further, the step of adjusting the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve includes: calculating the change value of the opening degree of the electronic expansion valve before and after adjusting the opening degree; when the change value is greater than or equal to the opening degree threshold, reducing the rotational speed of the outdoor fan to the first rotational speed; when the change value is less than the opening degree threshold, reducing the rotational speed of the outdoor fan to the second rotational speed; where the first rotational speed is greater than the second rotational speed.

[0077] Exemplarily, refer to Figure 4 ,Figure 4 This is the second working flowchart of the controller in the air conditioner provided by the embodiment of the present invention. The controller is further configured to execute steps S211 to S214:

[0078] S211. Calculate the opening change value of the electronic expansion valve before and after adjusting the opening, and then enter step S212.

[0079] S212. Determine whether the opening change value is greater than or equal to the opening threshold. If so, enter step S213; if not, enter step S14.

[0080] S213. When the opening change value is greater than or equal to the opening threshold, reduce the rotational speed of the outdoor fan to the first rotational speed.

[0081] S214. When the opening change value is less than the opening threshold, reduce the rotational speed of the outdoor fan to the second rotational speed.

[0082] Exemplarily, judge the opening change of the electronic expansion valve: X1 - X0 = ΔX. If it is greater than or equal to the opening threshold d, the rotational speed of the outdoor fan is reduced by Y1 turns to the first rotational speed; if it is less than the opening threshold d, the rotational speed of the outdoor fan is reduced by Y2 to the second rotational speed, where Y1 < Y2.

[0083] Further, the processes of the above steps S11 to S21 can be referred to: when the inlet temperature Ti of the evaporator satisfies: the second target evaporation temperature 3°C < the inlet temperature Ti of the evaporator ≤ the third target evaporation temperature 10°C and lasts for 1 min, by judging whether the outlet temperature of the condenser satisfies the outlet temperature To of the condenser - the target condensation temperature Tc = Δt ≥ 5°C. If it is satisfied, the opening of the electronic expansion valve is reduced by 12 steps, and the rotational speed of the outdoor fan directly drops by 20 turns, and it operates at the current valve opening and rotational speed for 1 minute; if it is not satisfied, the opening of the electronic expansion valve is reduced by 2 * Δt, and then judge the opening change ΔX of the electronic expansion valve. When it satisfies X1 - X0 = ΔX ≥ 6, the outdoor fan is reduced by 10 turns; if it is not satisfied, it is reduced by 20 turns, and at the same time, it operates at the current valve opening and rotational speed for 1 minute.

[0084] Specifically, the controller is further configured to: when the inlet temperature of the evaporator is within the preset medium temperature range and lasts for the first time, control the outdoor fan to stop working; after the outdoor fan stops working, when it detects that the inlet temperature of the evaporator is greater than the first high temperature threshold and lasts for the second time, control the outdoor fan to start.

[0085] Exemplarily, refer to Figure 5 , Figure 5 This is the third working flowchart of the controller in the air conditioner provided by the embodiment of the present invention. After executing step S13, the controller is further configured to execute steps S31 to S36:

[0086] S31. Determine whether the inlet temperature of the evaporator is within the medium-temperature range. If so, execute step S32; if not, execute the remaining control logics, such as steps S14 - S21, steps S41 - S46, or steps S51 - S53.

[0087] S32. Determine whether the duration for which the inlet temperature of the evaporator remains within the medium-temperature range is greater than the first time. If so, proceed to step S33; if not, return to step S31.

[0088] S33. When the inlet temperature of the evaporator is within the preset medium-temperature range and lasts for the first time, control the outdoor fan to stop working, and then enter step S34.

[0089] S34. After the outdoor fan stops working, detect whether the inlet temperature of the evaporator is greater than the first high-temperature threshold. If so, enter step S35; if not, return to step S34.

[0090] S35. Determine whether the duration for which the inlet temperature of the evaporator is greater than the first high-temperature threshold is greater than the second time. If so, enter step S36; if not, return to step S34.

[0091] S36. When it is detected that the inlet temperature of the evaporator is greater than the first high-temperature threshold and lasts for the second time, control the outdoor fan to start.

[0092] Exemplarily, if the first target evaporation temperature Te1 ≤ the inlet temperature of the evaporator Ti ≤ the second target evaporation temperature Te2 and lasts for td1, the outdoor fan stops working. By stopping the outdoor fan, the heat exchange of the outdoor-side heat exchanger is quickly reduced, thereby quickly increasing the condensation pressure, further increasing the condenser outlet temperature, and synchronously increasing the inlet temperature of the evaporator, avoiding poor indoor heat exchange or too low outlet air temperature due to the low inlet temperature of the evaporator, which affects the customer experience. After the outdoor fan stops working, the inlet temperature of the evaporator will continuously rise. By determining that the inlet temperature of the evaporator Ti > Te5 and lasts for td2, if the condition is met, it is determined that the inlet temperature of the evaporator meets the requirements at this time, and the outdoor fan can be restarted; otherwise, the outdoor fan continues to stop working until the condition that the inlet temperature of the evaporator Ti > Te5 and lasts for td2 is met, and then the outdoor fan is restarted.

[0093] Further, the processes of the above steps S31 to S36 can be referred to as follows: 0°C ≤ Ti ≤ 3°C and last for 1 minute, the outdoor fan stops working, and then it is judged whether the evaporator inlet temperature satisfies Ti > 8°C and lasts for 3 minutes. If it is satisfied, the external fan restarts; if not, the external fan continues to remain in the stopped state until the condition is met. If 0°C ≤ Ti ≤ 3°C and lasts for 1 minute is not satisfied, the next stage of logical judgment is entered.

[0094] Specifically, the controller is further configured to: when the evaporator inlet temperature is within a preset low temperature range and lasts for a first time, control the compressor and the outdoor fan to stop working; after the compressor and the outdoor fan stop working, when it is detected that the evaporator inlet temperature is greater than a second high temperature threshold and lasts for a second time, control the compressor and the outdoor fan to start.

[0095] Exemplarily, refer to Figure 6 , Figure 6 which is the fourth working flow chart of the controller in the air conditioner provided by the embodiment of the present invention. After executing step S13, the controller is further configured to execute steps S41 to S46:

[0096] S41. Judge whether the evaporator inlet temperature is within the low temperature range. If so, execute step S42; if not, execute the remaining control logics, such as steps S14 to S21, steps S31 to S36, or steps S51 to S53.

[0097] S42. Judge whether the duration of the evaporator inlet temperature within the low temperature range is greater than the first time. If so, enter step S43; if not, return to step S41.

[0098] S43. When the evaporator inlet temperature is within the preset low temperature range and lasts for the first time, control the compressor and the outdoor fan to stop working, and then enter step S44.

[0099] S44. After the compressor and the outdoor fan stop working, detect whether the evaporator inlet temperature is greater than the second temperature threshold. If so, enter step S45; if not, return to step S44.

[0100] S45. Judge whether the duration of the evaporator inlet temperature greater than the second high temperature threshold is greater than the second time. If so, enter step S46; if not, return to step S44.

[0101] S46. When it is detected that the evaporator inlet temperature is greater than the second high temperature threshold and lasts for the second time, control the compressor and the outdoor fan to start.

[0102] Exemplarily, if the inlet temperature of the evaporator Ti < the first target evaporation temperature Te1 and lasts for td1, at this time, the compressor and the outdoor fan stop working, so as to avoid poor heat exchange of the evaporator due to too low inlet temperature of the evaporator when the inlet temperature of the evaporator Ti is too low, resulting in continuous decrease of the evaporation temperature of the air conditioner, thus causing slow frosting, and even turning into icing when the frost layer reaches a certain thickness, and at the same time, there is a dripping phenomenon due to the thick ice layer during defrosting, which seriously affects the customer experience. After the compressor and the outdoor fan stop working, the inlet temperature Ti of the evaporator rises rapidly. By judging that the inlet temperature of the evaporator Ti > Te4 and lasts for td2, if the condition is met, it is judged that the frost layer has been removed at this time, and the compressor and the outdoor fan can be restarted. Otherwise, the compressor and the outdoor fan continue to stop working until the inlet temperature of the evaporator Ti > Te4 and lasts for td2, and then the compressor and the outdoor fan are restarted.

[0103] Exemplarily, the process of the above steps S41 - S46 can be referred to as: Ti < 0°C and lasts for 1 minute, the compressor and the outdoor fan stop working, and then it is judged whether the inlet temperature of the evaporator meets the condition that the inlet temperature of the evaporator Ti > 5°C and lasts for 3 minutes. If it is met, the outdoor fan and the compressor are restarted. If not, the outdoor fan and the compressor continue to remain in the stopped state until the condition is met.

[0104] Specifically, the controller is further configured to: when the inlet temperature of the evaporator is within a preset ultra - high temperature range, control the compressor, the indoor fan, and the outdoor fan to operate at the current speed, and keep the opening degree of the electronic expansion valve unchanged.

[0105] Exemplarily, refer to Figure 7 , Figure 7 which is the fifth working flowchart of the controller in the air conditioner provided by the embodiment of the present invention. After executing step S13, the controller is further configured to execute steps S51 - S53:

[0106] S51. Judge whether the inlet temperature of the evaporator is within the ultra - high temperature range. If so, enter step S52; if not, execute the remaining control logics, such as steps S14 - S21, steps S31 - S36, or steps S41 - S46.

[0107] S52. When the inlet temperature of the evaporator is within the preset ultra - high temperature range, control the compressor, the indoor fan, and the outdoor fan to operate at the current speed, and then enter step S53.

[0108] S53. Keep the opening degree of the electronic expansion valve unchanged.

[0109] Exemplarily, if the inlet temperature of the evaporator Ti > Te3, it operates according to the current valve opening and the fan speed.

[0110] Further, the above steps are the control logics for the outdoor fan, the compressor, and the electronic expansion valve. In the embodiments of the present invention, the control logic for the indoor fan in a low-temperature environment is also provided.

[0111] Specifically, the controller is further configured to: when the inlet temperature of the evaporator is within a preset low-temperature range, control the indoor fan to stop working; after the indoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than a second high-temperature threshold and lasts for a second time, control the indoor fan to start.

[0112] Exemplarily, refer to Figure 8 , Figure 8 is the sixth working flowchart of the controller in the air conditioner provided by the embodiments of the present invention. After executing step S13, the controller is further configured to execute steps S61 - S65:

[0113] S61. Determine whether the inlet temperature of the evaporator is within the low-temperature range. If so, execute step S62; if not, execute the remaining control logics.

[0114] S62. When the inlet temperature of the evaporator is within the preset low-temperature range, control the indoor fan to stop working, and then enter step S63.

[0115] S63. After the indoor fan stops working, detect whether the inlet temperature of the evaporator is greater than the second temperature threshold. If so, enter step S64; if not, return to step S63.

[0116] S64. Determine whether the duration for which the inlet temperature of the evaporator is greater than the second high-temperature threshold is greater than the second time. If so, enter step S65; if not, return to step S63.

[0117] S46. When it is detected that the inlet temperature of the evaporator is greater than the second high-temperature threshold and lasts for the second time, control the indoor fan to start.

[0118] Exemplarily, if the inlet temperature of the evaporator Ti < Te1, the indoor fan stops running, avoiding the outlet air temperature being too low due to the too low inlet temperature of the evaporator, which seriously affects the customer's usage experience. By judging whether Ti > Te4 is satisfied and lasts for td2, if this condition is met, the indoor fan restarts; otherwise, the indoor fan continues to remain in the stopped state.

[0119] Exemplarily, the processes of the above steps S61 - S65 can be referred to as follows: when Ti < 0°C, the indoor fan stops running, and then it is determined whether the evaporator inlet temperature satisfies the condition that the evaporator inlet temperature Ti > 5°C and lasts for 3 minutes. If it is satisfied, the indoor fan restarts; if not, the indoor fan remains stopped until the condition is met. If the evaporator inlet temperature does not satisfy the condition that the evaporator inlet temperature Ti < 0°C, then the next - stage logical judgment is entered.

[0120] Specifically, the controller is further configured to: when the evaporator inlet temperature is within a preset medium - temperature range or high - temperature range, increase the rotational speed of the indoor fan; after increasing the rotational speed of the indoor fan, control the indoor fan to run at the current rotational speed for a period of time and then restore to the initial rotational speed.

[0121] Exemplarily, refer to Figure 9 , Figure 9 FIG. is the seventh working flowchart of the controller in the air conditioner provided by the embodiment of the present invention. After executing step S13, the controller is further configured to execute steps S71 - S73:

[0122] S71. Determine whether the evaporator inlet temperature is within a medium - temperature range or high - temperature range. If so, enter step S72; if not, return to step S71.

[0123] S72. When the evaporator inlet temperature is within a preset medium - temperature range or high - temperature range, increase the rotational speed of the indoor fan, and then enter step S73.

[0124] S73. After increasing the rotational speed of the indoor fan, control the indoor fan to run at the current rotational speed for a period of time and then restore to the initial rotational speed.

[0125] Exemplarily, if the evaporator inlet temperature satisfies Te3 > Ti and the evaporator inlet temperature Ti ≥ Te1, the indoor fan increases by Y1 revolutions. By increasing the current rotational speed of the indoor fan, the current indoor air - outlet volume is increased, the indoor heat - exchange capacity is enhanced, thereby increasing the current evaporator inlet temperature. At the same time, due to the increased air volume, the current indoor air - outlet temperature can be increased, so that the air - outlet temperature is maintained within a reasonable temperature range, improving the user's comfort and enhancing the user's experience. At the same time, run at the current fan rotational speed for a time td1 to avoid misjudgment of the indoor fan due to errors.

[0126] Exemplarily, the processes of the above steps S71 - S73 can be referred to as follows: when the evaporator inlet temperature satisfies 10°C > the evaporator inlet temperature Ti ≥ 0°C, the indoor fan increases by 10 revolutions and maintains the current rotational speed for 1 minute; if not satisfied, the current rotational speed of the indoor fan is maintained.

[0127] Compared with the prior art, for the air conditioner disclosed in the embodiments of the present invention, when the air conditioner enters the cooling mode, when the outdoor ambient temperature is lower than or equal to a predetermined temperature value, the value of the indoor heat exchanger temperature sensor is detected at this time, judged, and different control logics are adopted under different values. By controlling the start and stop of the compressor, the start and stop of the outdoor fan, adjusting the refrigerant flow rate, and at the same time cooperating with the control logic such as adjusting the rotation speed of the outdoor fan, and at the same time controlling the adjustment of the rotation speed of the indoor fan, the use efficiency of the heat exchanger of the air conditioner is adjusted, thereby improving the working energy efficiency of the air conditioner, and adjusting the energy output of the air conditioner, so that its use comfort is improved, and the air conditioner is further protected to avoid water leakage or even icing of the air conditioner in extreme cases.

[0128] See Figure 10 , Figure 10 FIG. is a flowchart of a control method for an air conditioner provided by an embodiment of the present invention. The control method for the air conditioner described in the embodiments of the present invention is implemented by a controller provided in the air conditioner. The control method for the air conditioner includes:

[0129] S1. When the air conditioner enters the cooling mode, control the indoor fan, compressor, and outdoor fan to operate;

[0130] S2. When it is detected that the outdoor ambient temperature is lower than the ambient temperature threshold, obtain the inlet temperature of the evaporator;

[0131] S3. When the inlet temperature of the evaporator is within a preset high temperature range and lasts for a first period of time, obtain the outlet temperature of the condenser;

[0132] S4. Calculate the temperature difference between the outlet temperature of the condenser and the target condensation temperature;

[0133] S5. When the temperature difference is greater than or equal to the temperature difference threshold, reduce the opening of the electronic expansion valve and reduce the rotation speed of the outdoor fan; when the temperature difference is less than the temperature threshold, reduce the opening of the electronic expansion valve, and adjust the rotation speed of the outdoor fan according to the change in the opening of the electronic expansion valve.

[0134] Exemplarily, when the air conditioner enters the cooling mode, when the ambient temperature Tw detected by the outdoor environment sensor is less than or equal to 15°C (ambient temperature threshold), the air conditioner enters the logical judgment. If Te2 < Ti ≤ Te3 and lasts for td1, then by detecting the value of the outdoor coil temperature sensor, the current condenser outlet temperature is obtained, and the condenser outlet temperature To - the target condensation temperature Tc = Δt is calculated. When the temperature difference is greater than or equal to the temperature difference threshold, reducing the opening degree of the electronic expansion valve includes: reducing the opening degree of the electronic expansion valve according to a preset fixed adjustment value. If the judgment result is that Δt is greater than or equal to a, the electronic expansion valve directly reduces by X steps (fixed adjustment value), and at the same time the outdoor fan directly reduces by Y1 revolutions. This can quickly reduce the current opening degree of the electronic expansion valve, quickly reduce the system flow rate by quickly reducing the system flow rate, thereby quickly increasing the current system condensation pressure, thereby increasing the condenser outlet temperature. At the same time, by reducing the outdoor fan speed, the outside heat exchange capacity is reduced, thereby increasing the current system condensation pressure, and further increasing the condenser outlet temperature, and synchronously increasing the evaporator inlet temperature.

[0135] Exemplarily, when the temperature difference is less than the temperature threshold, reducing the opening degree of the electronic expansion valve includes: calculating the product of the temperature difference and a preset expansion valve coefficient as the target adjustment value, and reducing the opening degree of the electronic expansion valve according to the target adjustment value. If the judgment result is that Δt is less than a, the opening degree of the electronic expansion valve is reduced by X = c * Δt, where c is the preset expansion valve coefficient, and the speed of the outdoor fan is adjusted according to the change in the opening degree of the electronic expansion valve in step S20. By judging the magnitude of the temperature difference Δt between the condenser outlet temperature and the target condensation temperature, if the temperature difference value Δt is less than a, it means that the current condenser outlet temperature is relatively low, and the opening degree of its electronic expansion valve and the speed of the outdoor fan can be adjusted by a large margin, so as to more quickly increase the current system condensation pressure, thereby greatly increasing the condenser outlet temperature, which is beneficial to increasing the evaporator inlet temperature. After adjusting the opening degree of the electronic expansion valve and the outdoor fan, it is necessary to keep the current valve opening degree and the outdoor fan speed running for a period of time td1 and then re-enter the above condition judgment, so as to avoid the system being unable to respond due to the rapid change of the valve opening degree and the outdoor fan speed, resulting in the system being in a fluctuating state all the time.

[0136] Specifically, adjusting the speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve includes:

[0137] Calculating the change value of the opening degree of the electronic expansion valve before and after adjusting the opening degree;

[0138] When the change value of the opening degree is greater than or equal to the opening degree threshold, reducing the speed of the outdoor fan to the first speed;

[0139] When the opening change value is less than the opening threshold, reduce the rotational speed of the outdoor fan to the second rotational speed; wherein, the first rotational speed is greater than the second rotational speed.

[0140] Exemplarily, judge the change in the opening of the electronic expansion valve: X1 - X0 = ΔX. If it is greater than or equal to the opening threshold d, the rotational speed of the outdoor fan is reduced by Y1 turns to the first rotational speed. If it is less than the opening threshold d, the rotational speed of the outdoor fan is reduced by Y2 to the second rotational speed, where Y1 < Y2.

[0141] Specifically, the air conditioner control method further includes:

[0142] When the inlet temperature of the evaporator is within a preset medium temperature range and lasts for the first period of time, control the outdoor fan to stop working;

[0143] After the outdoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than the first high temperature threshold and lasts for the second period of time, control the outdoor fan to start.

[0144] Exemplarily, if the first target evaporation temperature Te1 ≤ the inlet temperature Ti of the evaporator ≤ the second target evaporation temperature Te2 and lasts for td1, the outdoor fan stops working. By stopping the outdoor fan, the heat exchange of the outdoor side heat exchanger is quickly reduced, thereby quickly increasing the condensation pressure, and then increasing the condenser outlet temperature, so that the inlet temperature of the evaporator is synchronously increased, avoiding poor indoor heat exchange or too low outlet air temperature due to too low inlet temperature of the evaporator, which affects the customer experience. After the outdoor fan stops working, the inlet temperature of the evaporator will continuously rise. By judging that the inlet temperature of the evaporator Ti > Te5 and lasts for td2, if the condition is met, it is judged that the inlet temperature of the evaporator meets the requirements at this time, and the outdoor fan can be restarted. Otherwise, the outdoor fan continues to stop working until the condition that the inlet temperature of the evaporator Ti > Te5 and lasts for td2 is met, and then the outdoor fan is restarted.

[0145] Specifically, the air conditioner control method further includes:

[0146] When the inlet temperature of the evaporator is within a preset low temperature range and lasts for the first period of time, control the compressor and the outdoor fan to stop working;

[0147] After the compressor and the outdoor fan stop working, when it is detected that the inlet temperature of the evaporator is greater than the second high temperature threshold and lasts for the second period of time, control the compressor and the outdoor fan to start.

[0148] Exemplarily, if the inlet temperature of the evaporator Ti < the first target evaporation temperature Te1 and lasts for td1, the compressor and the outdoor fan stop working at this time, to avoid poor heat exchange of the evaporator due to the too low inlet temperature of the evaporator when the inlet temperature of the evaporator Ti is too low, resulting in a continuous decrease in the evaporation temperature of the air conditioner, thus causing slow frosting, and even when the frost layer reaches a certain level, it becomes icing and there is a dripping phenomenon when defrosting due to the thick ice layer, seriously affecting the customer's use experience. After the compressor and the outdoor fan stop working, the inlet temperature Ti of the evaporator rises rapidly. By judging that the inlet temperature of the evaporator Ti > Te4 and lasts for td2, if the condition is met, then it is judged that the frost layer has been completely removed at this time, and the compressor and the outdoor fan can be restarted. Otherwise, the compressor and the outdoor fan continue to stop working until the inlet temperature of the evaporator Ti > Te4 and lasts for td2, and then the compressor and the outdoor fan are restarted.

[0149] Specifically, the air conditioner control method further includes:

[0150] When the inlet temperature of the evaporator is within a preset ultra-high temperature range, control the compressor, the indoor fan, and the outdoor fan to operate at the current speed, and keep the opening degree of the electronic expansion valve unchanged.

[0151] Exemplarily, if the inlet temperature of the evaporator Ti > Te3, then operate according to the current valve opening degree and fan speed.

[0152] Specifically, the air conditioner control method further includes:

[0153] When the inlet temperature of the evaporator is within a preset low temperature range, control the indoor fan to stop working;

[0154] After the indoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than the second high temperature threshold and lasts for the second time, control the indoor fan to start.

[0155] Exemplarily, if the inlet temperature of the evaporator Ti < Te1, the indoor fan stops running to avoid the outlet air temperature being too low due to the too low inlet temperature of the evaporator, seriously affecting the customer's use experience. By judging whether the inlet temperature of the evaporator Ti > Te4 and lasts for td2 is satisfied, if this condition is met, the indoor fan is restarted, otherwise the indoor fan continues to remain in the stopped state.

[0156] Specifically, the air conditioner control method further includes:

[0157] When the inlet temperature of the evaporator is within a preset medium temperature range or high temperature range, increase the speed of the indoor fan;

[0158] After increasing the rotation speed of the indoor fan, control the indoor fan to run at the current rotation speed for a period of time and then restore to the initial rotation speed.

[0159] Exemplarily, if the evaporator inlet temperature satisfies Te3 > Ti and the evaporator inlet temperature Ti ≥ Te1, the indoor fan is increased by Y1 revolutions. By increasing the current rotation speed of the indoor fan, the current indoor air output volume is increased, the indoor heat exchange capacity is enhanced, thereby increasing the current evaporator inlet temperature. At the same time, due to the increased air volume, the current indoor air outlet temperature can be increased, so that the air outlet temperature is maintained within a reasonable temperature range, improving the user's comfort and enhancing the user's experience. At the same time, operate at the current fan rotation speed for a time td1 to avoid misjudgment of the indoor fan due to errors.

[0160] Compared with the prior art, the air conditioner control method disclosed in the embodiment of the present invention, when the air conditioner enters the cooling mode, when the outdoor ambient temperature is lower than or equal to a predetermined temperature value, at this time, the value of the indoor heat exchanger temperature sensor is detected, judged, and different control logics are adopted under different values. By controlling the start and stop of the compressor, the start and stop of the outdoor fan, adjusting the refrigerant flow rate, and at the same time cooperating with the control logic such as adjusting the rotation speed of the outdoor fan, and at the same time controlling the adjustment of the rotation speed of the indoor fan, thereby adjusting the use efficiency of the air conditioner heat exchanger, further improving the working energy efficiency of the air conditioner, and adjusting the energy output of the air conditioner, so that its use comfort is improved, and the air conditioner is further protected to avoid water leakage or even icing of the air conditioner in extreme cases.

[0161] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. An air conditioner, characterized in that, it includes: an indoor unit for adjusting the temperature and humidity of indoor air, and an indoor fan is provided in the indoor unit; an outdoor unit connected to the indoor unit through a connection pipe, and a compressor, an outdoor fan and an electronic expansion valve are provided in the outdoor unit; a controller for controlling the operation of the indoor fan, the compressor and the outdoor fan when the air conditioner enters the cooling mode; obtaining the inlet temperature of the evaporator when it is detected that the outdoor ambient temperature is lower than the ambient temperature threshold; when the inlet temperature of the evaporator is within a preset high temperature range and lasts for a first time, obtaining the outlet temperature of the condenser; calculating the temperature difference between the outlet temperature of the condenser and the target condensation temperature; when the temperature difference is greater than or equal to the temperature difference threshold, reducing the opening degree of the electronic expansion valve and reducing the rotational speed of the outdoor fan; when the temperature difference is less than the temperature threshold, reducing the opening degree of the electronic expansion valve, and adjusting the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve; wherein, adjusting the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve includes: calculating the change value of the opening degree of the electronic expansion valve before and after adjusting the opening degree; when the change value is greater than or equal to the opening degree threshold, reducing the rotational speed of the outdoor fan to a first rotational speed; when the change value is less than the opening degree threshold, reducing the rotational speed of the outdoor fan to a second rotational speed; wherein, the first rotational speed is greater than the second rotational speed; when the temperature difference is greater than or equal to the temperature difference threshold, reducing the opening degree of the electronic expansion valve includes: reducing the opening degree of the electronic expansion valve according to a preset fixed adjustment value; when the temperature difference is less than the temperature threshold, reducing the opening degree of the electronic expansion valve includes: calculating the product of the temperature difference and a preset expansion valve coefficient as the target adjustment value, and reducing the opening degree of the electronic expansion valve according to the target adjustment value.

2. The air conditioner according to claim 1, characterized in that, the controller is further configured to: when the inlet temperature of the evaporator is within a preset medium temperature range and lasts for a first time, control the outdoor fan to stop working; after the outdoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than a first high temperature threshold and lasts for a second time, control the outdoor fan to start.

3. The air conditioner according to claim 1, characterized in that, the controller is further configured to: when the inlet temperature of the evaporator is within a preset low temperature range and lasts for a first time, control the compressor and the outdoor fan to stop working; after the compressor and the outdoor fan stop working, when it is detected that the inlet temperature of the evaporator is greater than a second high temperature threshold and lasts for a second time, control the compressor and the outdoor fan to start.

4. The air conditioner according to claim 1, characterized in that, the controller is further configured to: when the inlet temperature of the evaporator is within a preset ultra-high temperature range, control the compressor, the indoor fan and the outdoor fan to operate at the current rotational speed, and keep the opening degree of the electronic expansion valve unchanged.

5. The air conditioner according to claim 1, characterized in that, the controller is further configured to: When the inlet temperature of the evaporator is within a preset low temperature range, control the indoor fan to stop working; After the indoor fan stops working, when it is detected that the inlet temperature of the evaporator is greater than a second high temperature threshold and lasts for a second period of time, control the indoor fan to start.

6. The air conditioner according to claim 1, characterized in that, the controller is further configured to: When the inlet temperature of the evaporator is within a preset medium temperature range or high temperature range, increase the rotational speed of the indoor fan; After increasing the rotational speed of the indoor fan, control the indoor fan to run at the current rotational speed for a period of time and then return to the initial rotational speed.

7. An air conditioner control method, characterized in that, comprising: When the air conditioner enters the cooling mode, control the indoor fan, the compressor and the outdoor fan to run; When it is detected that the outdoor ambient temperature is lower than the ambient temperature threshold, obtain the inlet temperature of the evaporator; When the inlet temperature of the evaporator is within a preset high temperature range and lasts for a first period of time, obtain the outlet temperature of the condenser; Calculate the temperature difference between the outlet temperature of the condenser and the target condensation temperature; When the temperature difference is greater than or equal to the temperature difference threshold, reduce the opening degree of the electronic expansion valve and lower the rotational speed of the outdoor fan; when the temperature difference is less than the temperature threshold, reduce the opening degree of the electronic expansion valve, and adjust the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve; Wherein, the adjusting the rotational speed of the outdoor fan according to the change in the opening degree of the electronic expansion valve includes: calculating the change value of the opening degree of the electronic expansion valve before and after adjusting the opening degree; when the change value is greater than or equal to the opening degree threshold, reduce the rotational speed of the outdoor fan to the first rotational speed; When the change value is less than the opening degree threshold, reduce the rotational speed of the outdoor fan to the second rotational speed; wherein, the first rotational speed is greater than the second rotational speed; When the temperature difference is greater than or equal to the temperature difference threshold, the reducing the opening degree of the electronic expansion valve includes: reducing the opening degree of the electronic expansion valve according to a preset fixed adjustment value; When the temperature difference is less than the temperature threshold, the reducing the opening degree of the electronic expansion valve includes: calculating the product of the temperature difference and a preset expansion valve coefficient as the target adjustment value, and reducing the opening degree of the electronic expansion valve according to the target adjustment value.

Images