Control method of air conditioner, air conditioner, and storage medium

Abstract

The application provides a control method of an air conditioner, the air conditioner and a storage medium. The air conditioner comprises a refrigeration cycle system and an external fan. The refrigeration cycle system comprises a compressor, a condenser and an evaporator. The external fan is used for heat dissipation of the condenser. The control method comprises the following steps: when the air conditioner operates in a low-temperature mode, detecting an oil temperature overheat degree of the compressor; if the oil temperature overheat degree reaches a preset condition, obtaining a first pressure value of the condenser and a second pressure value of the evaporator; if the first pressure value is lower than a preset high-pressure threshold value and the second pressure value is higher than a preset low-pressure threshold value, reducing the preset high-pressure threshold value to obtain an adjusted preset high-pressure threshold value; and controlling the external fan to stop according to a comparison relationship between the adjusted preset high-pressure threshold value and an actual pressure value of the condenser. The control method can prolong a period in which the condensing pressure reaches a stop point pressure value of the external fan under low temperature, avoid frequent start and stop of the external fan, and prevent large pressure fluctuation in the refrigeration system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of air conditioners, and particularly relates to an air conditioner control method, an air conditioner and a storage medium. BACKGROUND

[0002] An air conditioner is a device for adjusting and controlling parameters such as temperature, humidity and flow rate of air in a building. In the outer circulation air system of the air conditioner, the outer fan of the air conditioner introduces outdoor cold air to the condenser to dissipate heat from the condenser. In the prior art, the start and stop of the outer fan are generally controlled according to the condenser outlet temperature. However, considering the hysteresis of temperature detection, some air conditioners control the start and stop of the outer fan according to the condenser pressure value. However, even if the start and stop of the outer fan are controlled according to the condenser pressure value, there is still a problem that the outer fan is prone to frequent start and stop at low temperature, thereby causing large pressure fluctuation of the refrigeration system and affecting the reliability of the air conditioner operation. SUMMARY

[0003] The embodiments of the present application provide an air conditioner control method, an air conditioner and a storage medium, which can solve the problem that frequent start and stop of the outer fan of the air conditioner at low temperature leads to large pressure fluctuation of the refrigeration system and affects the reliability of the air conditioner operation.

[0004] To achieve the above object, the present application provides the following technical scheme:

[0005] An air conditioner control method, the air conditioner comprising a refrigeration cycle system and an outer fan, the refrigeration cycle system comprising a compressor, a condenser and an evaporator, the outer fan being used for dissipating heat from the condenser, the control method comprising:

[0006] detecting an oil temperature superheat degree of the compressor when the air conditioner operates in a low temperature mode;

[0007] if the oil temperature superheat degree reaches a preset condition, obtaining a first pressure value of the condenser and a second pressure value of the evaporator;

[0008] if the first pressure value is lower than a preset high pressure threshold value and the second pressure value is higher than a preset low pressure threshold value, reducing the preset high pressure threshold value to obtain an adjusted preset high pressure threshold value;

[0009] controlling the outer fan according to a comparison relationship between the adjusted preset high pressure threshold value and an actual pressure value of the condenser.

[0010] In some embodiments, the air conditioner further comprises an electric heater, and after the detection of the oil temperature superheat degree of the compressor, the method further comprises:

[0011] If the oil temperature overheating degree does not reach the preset condition, the electric heater is controlled to preheat the compressor until the oil temperature overheating degree reaches the preset condition is detected.

[0012] In some embodiments, the control of the electric heater to preheat the compressor until the oil temperature overheating degree reaches the preset condition includes:

[0013] Turning on the electric heater;

[0014] If the oil temperature overheating degree does not reach the preset condition after waiting for a second preset time length, the heating power of the electric heater is increased by a first preset period until the oil temperature overheating degree reaches the preset condition is detected;

[0015] Turning off the electric heater.

[0016] In some embodiments, if the oil temperature overheating degree reaches the preset condition, the first pressure value of the condenser and the second pressure value of the evaporator are obtained, including:

[0017] Obtaining a preset oil temperature;

[0018] If the oil temperature overheating degree is higher than the preset oil temperature for a first preset time length, the first pressure value of the condenser and the second pressure value of the evaporator are obtained.

[0019] In some embodiments, the control of the electric heater to preheat the compressor until the oil temperature overheating degree reaches the preset condition includes:

[0020] If the actual pressure value of the condenser is lower than the adjusted preset high pressure threshold, the electric heater is controlled.

[0021] In some embodiments, the control method of the air conditioner further includes:

[0022] If the first pressure value is higher than or equal to a preset high pressure threshold, the current preset high pressure threshold is maintained to continue the comparison relationship with the actual pressure value of the condenser to control the compressor to stop;

[0023] If the first pressure value is lower than the preset high pressure threshold, and the second pressure value is lower than or equal to a preset low pressure threshold, the air conditioner is controlled to stop running and an alarm is issued.

[0024] In some embodiments, the air conditioner further includes a flow guide for guiding hot air to the compressor to warm up the compressor, and before the air conditioner runs in the low temperature mode, the air conditioner further includes:

[0025] acquire a first shutdown duration of the compressor in this shutdown when detecting that the outdoor temperature is lower than a preset temperature;

[0026] if the first shutdown duration is greater than a preset shutdown duration, start the flow inducer.

[0027] In some embodiments, after starting the flow inducer, the method further comprises:

[0028] if the oil temperature superheat reaches the preset condition, stop the flow inducer.

[0029] An air conditioner comprises:

[0030] a refrigeration cycle system comprising a compressor, a condenser and an evaporator;

[0031] an outdoor fan for dissipating heat of the condenser;

[0032] a controller configured to:

[0033] detect an oil temperature superheat of the compressor when the air conditioner is running in a low-temperature mode;

[0034] if the oil temperature superheat reaches a preset condition, acquire a first pressure value of the condenser and a second pressure value of the evaporator;

[0035] if the first pressure value is lower than a preset high-pressure threshold value and the second pressure value is higher than a preset low-pressure threshold value, decrease the preset high-pressure threshold value to obtain an adjusted preset high-pressure threshold value;

[0036] control the outdoor fan according to a comparison relationship between the adjusted preset high-pressure threshold value and an actual pressure value of the condenser.

[0037] A storage medium having a computer program stored thereon, the computer program being configured to execute the control method of the air conditioner when running.

[0038] The control method of the air conditioner, the air conditioner and the storage medium provided by the embodiments of the present application can intelligently adjust a preset high-pressure threshold value according to a condensing pressure and an evaporating pressure in a low-temperature mode of the air conditioner, can prolong a period in which a condensing pressure reaches a shutdown point pressure value of an outdoor fan in a low temperature, and can avoid frequent start and stop of the outdoor fan and prevent large pressure fluctuation in a refrigeration system. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0040] For a more complete understanding of the present application and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like parts throughout the several figures. In the following description, same reference numerals indicate same parts.

[0041] Figure 1 A first flow chart of a control method of an air conditioner provided in an embodiment of the present application.

[0042] Figure 2 A second flow chart of a control method of an air conditioner provided in an embodiment of the present application.

[0043] Figure 3 A structure diagram of a control device of an air conditioner provided in an embodiment of the present application.

[0044] Figure 4 A structure diagram of an air conditioner provided in an embodiment of the present application.

[0045] Figure 5 Another structure diagram of an air conditioner provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, any other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0047] The embodiments of the present application provide a control method of an air conditioner. The air conditioner can be a household air conditioner or a large air conditioning unit. Referring to Figure 1 , Figure 1 A first flow chart of a control method of an air conditioner provided in an embodiment of the present application. The air conditioner includes a refrigeration cycle system and an external fan. The refrigeration cycle system includes a compressor, a condenser and an evaporator. The external fan is used to dissipate heat from the condenser. The control method includes the following steps S101-S104:

[0048] Step S101: When the air conditioner is running in a low-temperature mode, detecting the oil temperature overheat degree of the compressor;

[0049] It should be noted that the air conditioner pre-stores a plurality of outdoor environment temperature segments corresponding to operating modes, and operating parameters corresponding to a plurality of operating modes. When the air conditioner is powered on, the target operating mode is determined according to the outdoor environment temperature, and the air conditioner runs in the target operating mode. For example, when the outdoor environment temperature is too low, the air conditioner enters the low-temperature mode, otherwise it enters the normal temperature mode. In some other embodiments, the air conditioner can also set a high-temperature mode, etc., which is not limited here.

[0050] The oil temperature superheat is an overheat of the lubricating oil in the compressor. For example, the method for obtaining the oil temperature superheat of the compressor includes: detecting the oil temperature of the compressor and the high pressure or the low pressure of the refrigeration cycle system in real time; determining the current oil temperature superheat of the compressor according to the detected oil temperature and the high pressure or the low pressure. Specifically, for the high-pressure cavity compressor, the current oil temperature superheat of the compressor is the difference between the oil temperature of the compressor and the difference between the saturation temperature of the refrigerant at the pressure corresponding to the high pressure; for the low-pressure cavity compressor, the current oil temperature superheat of the compressor is the difference between the oil temperature of the compressor and the difference between the saturation temperature of the refrigerant at the pressure corresponding to the low pressure. For example, the difference between the saturation temperature of the refrigerant at the pressure corresponding to the high / low pressure is obtained by the controller of the air conditioner by looking up the table.

[0051] Step S102: If the oil temperature superheat reaches the preset condition, the first pressure value of the condenser and the second pressure value of the evaporator are obtained.

[0052] It should be noted that in a low-temperature environment, the oil temperature superheat of the compressor is prone to be too low, which will affect the normal operation and service life of the compressor and reduce the refrigeration effect of the refrigeration cycle system. In this application, the oil temperature superheat reaching the preset condition means that the compressor has at least a certain oil temperature superheat to ensure reliable operation of the compressor.

[0053] In some embodiments, a high-pressure sensor can be arranged at the outlet end of the condenser to detect the first pressure value of the condenser. In addition, a low-pressure sensor can be arranged at the outlet end of the evaporator to detect the second pressure value of the evaporator.

[0054] It should be noted that the condensing pressure is an important parameter affecting the operation performance of the refrigeration system. When the condensing pressure is high, the discharge temperature of the compressor will rise, the compression ratio will increase, the refrigerating capacity will decrease, the power consumption will increase, and the high condensing pressure is also prone to cause equipment damage accidents. When the condensing pressure is too low, especially in winter when the cooling water temperature is low or the ambient temperature is low, the pressure difference before and after the thermal expansion valve is too small, the liquid supply power is insufficient, the flow of the condensing agent through the thermal expansion valve is sharply reduced, the refrigerating capacity is greatly reduced, and the refrigeration system is out of work. In addition, the low evaporator pressure will also reduce the refrigeration efficiency of the refrigeration system, and may also cause the evaporator and compressor to malfunction, and even cause the safety hazard of fluorine leakage. Therefore, in order to ensure the normal operation of the refrigeration system, the condensing pressure and the evaporating pressure must be controlled.

[0055] Step S103: If the first pressure value is lower than the preset high pressure threshold value, and the second pressure value is higher than the preset low pressure threshold value, the preset high pressure threshold value is reduced to obtain an adjusted preset high pressure threshold value.

[0056] It should be noted that the air conditioner controls the shutdown of the external fan according to a comparison relationship between the actual pressure value of the condenser and the preset high pressure threshold. For example, if the actual pressure value of the condenser is lower than or equal to the preset high pressure threshold, the external fan is turned off. In addition, the air conditioner also includes a preset start pressure value of the external fan, and the air conditioner controls the start of the external fan according to a comparison relationship between the actual pressure of the condenser and the preset start pressure value, wherein the preset start pressure value is greater than the preset high pressure threshold. For example, if the actual pressure of the condenser exceeds the preset start pressure value, the external fan is controlled to start.

[0057] Wherein, when the second pressure value is higher than the preset low pressure threshold, it indicates that the actual low pressure in the refrigeration system is higher than the minimum pressure allowed by the system, and will not affect the normal operation of the refrigeration system.

[0058] For example, reducing the preset high pressure threshold to obtain the adjusted preset high pressure threshold includes:

[0059] Obtaining a preset pressure value;

[0060] Reducing the preset high pressure threshold by the preset pressure value to obtain the adjusted preset high pressure threshold.

[0061] Wherein, the preset pressure value is a fixed value less than the preset high pressure threshold, for example, 0.1 MPa. In other embodiments, the preset pressure value can also be a fixed percentage value of the preset high pressure threshold, for example, the preset pressure value is equal to the product of the preset high pressure threshold and 0.1.

[0062] Step S104: controlling the external fan according to a comparison relationship between the adjusted preset high pressure threshold and the actual pressure value of the condenser.

[0063] Wherein, the actual pressure value is a subsequently detected pressure value of the condenser. Controlling the external fan includes controlling the operating state of the external fan. For example, if the actual pressure value of the condenser is lower than the adjusted preset high pressure threshold, the external fan is controlled to stop, otherwise the external fan is controlled to maintain the current operating state.

[0064] It can be understood that compared with the normal temperature condition, the condensing pressure of the air conditioner at low temperature is usually low, which leads to that the condensing pressure is more likely to be lower than the preset high pressure threshold, that is, the condensing pressure is more likely to reach the shutdown point pressure of the external fan. Therefore, based on the initial preset high pressure threshold, the external fan is more likely to be triggered to stop at low temperature, and after the external fan is stopped, the heat exchange of the condenser is reduced, and then the condensing pressure is increased, which soon triggers the start of the external fan, resulting in frequent start and stop of the external fan, and unstable pressure of the refrigeration system.

[0065] Based on the above problems, the control method of the application intelligently adjusts the preset high pressure threshold. Under the premise that the oil temperature superheat degree of the compressor reaches the preset condition, if the first pressure value is lower than the preset high pressure threshold, and the second pressure value of the evaporator is higher than the preset low pressure threshold, the preset high pressure threshold can be reduced to obtain an adjusted preset high pressure threshold, so as to ensure that the refrigeration system can normally operate. In actual application, since the adjusted preset high pressure threshold is smaller, the period of the actual pressure value of the condenser reaching the shutdown point pressure value of the external fan becomes longer, and the frequent start-stop of the external fan can be avoided.

[0066] The control method of the air conditioner provided by the embodiment of the application can intelligently adjust the preset high pressure threshold according to the condensing pressure and the evaporating pressure in the low temperature mode of the air conditioner, can prolong the period of the condensing pressure reaching the shutdown point pressure value of the external fan in the low temperature, can avoid the frequent start-stop of the external fan, and can prevent the pressure fluctuation in the refrigeration system from being large.

[0067] In some embodiments, the control method of the application further comprises:

[0068] If the first pressure value is higher than or equal to the preset high pressure threshold, the current preset high pressure threshold is maintained to continue the comparison relationship with the actual pressure value of the condenser to control the compressor.

[0069] If the first pressure value is lower than the preset high pressure threshold, and the second pressure value is lower than or equal to the preset low pressure threshold, the air conditioner is controlled to stop operating, and an alarm is issued.

[0070] For example, the air conditioner first judges whether the first pressure value is lower than the preset high pressure threshold. If the first pressure value is not lower than the preset high pressure threshold, the air conditioner continues to operate in the current operating state, and the preset high pressure threshold is not adjusted. If the first pressure value is lower than the preset high pressure threshold, it is further judged whether the second pressure value is higher than the preset low pressure threshold. If the second pressure value is higher than the preset low pressure threshold, the preset high pressure threshold is adjusted. Otherwise, the air conditioner is controlled to stop operating, and an alarm is issued.

[0071] It should be noted that if the first pressure value is lower than the preset high pressure threshold, and the second pressure value is lower than or equal to the preset low pressure threshold, the internal pressure of the refrigeration system is too low, and if the operation continues, there is a risk of causing a failure of the refrigeration system. Therefore, the air conditioner is stopped to avoid the failure.

[0072] In some embodiments, the air conditioner periodically executes the above control method in the low temperature mode. For example, when the air conditioner operates in the low temperature mode, the air conditioner executes the above control method every preset time interval to cope with the change of the external environment, and intelligently adjusts the preset high pressure threshold in real time.

[0073] In some embodiments, the air conditioner further comprises an electric heater, and after detecting the oil temperature superheat degree of the compressor, the method further comprises:

[0074] If the oil temperature overheating degree does not reach the preset condition, the electric heater is controlled to preheat the compressor until the oil temperature overheating degree reaches the preset condition is detected.

[0075] It can be understood that the working environment temperature of the air conditioner compressor is generally 4°C. When the ambient temperature is too low, the transmission oil in the machine body condenses, and the oil temperature overheating degree of the compressor is low, which will affect the normal start of the air conditioning unit, and the main machine often has difficulty in starting or even starts after a long period of poor working condition, which seriously affects the service life of the compressor. Therefore, by adding an electric heater to preheat the compressor, the above problems can be avoided.

[0076] Further, to improve the preheating efficiency of the electric heater on the compressor, wherein the electric heater is controlled to preheat the compressor until the oil temperature overheating degree reaches the preset condition can include:

[0077] turning on the electric heater;

[0078] If the oil temperature overheating degree does not reach the preset condition after waiting for the second preset time, the heating power of the electric heater is increased according to the first preset period until the oil temperature overheating degree reaches the preset condition is detected;

[0079] turning off the electric heater.

[0080] For example, the electric heater has multiple preset heating gears, each heating gear corresponding to different heating power, for example, the higher the heating gear, the higher the heating power, the higher the heating efficiency of the compressor, and the larger the corresponding power consumption. If the oil temperature overheating degree of the compressor still cannot reach the preset condition after the second preset time, it means that the preheating efficiency of the compressor is too low at the current ambient temperature and the current heating power, so the heating power of the electric heater is increased to improve the preheating efficiency. Through the above heating method, it can avoid high power consumption of the heater, and also avoid low preheating efficiency.

[0081] For example, the heating power of the electric heater is increased according to the first preset period, which specifically includes: the oil temperature overheating degree of the compressor is continuously detected within each period, and if the oil temperature overheating degree reaches the preset condition within the period, the process of step S102 is entered; if the oil temperature overheating degree does not reach the preset condition at the end of the period, the heating power of the electric heater is increased at the end of the period, and the next period is entered.

[0082] In some embodiments, if the electric heater has reached the maximum operating power, and the electric heater has been running at the maximum operating power for a third preset time length, and the oil temperature overheating degree has not reached the preset condition, the electric heater is turned off, and an alarm is issued or a backup preheating device is used to attempt to heat the compressor. It can be understood that the electric heater may also fail, resulting in the compressor being unable to be normally heated, and thus the oil temperature overheating degree of the compressor cannot reach the preset condition.

[0083] In some embodiments, if the oil temperature overheating degree reaches the preset condition, obtaining the first pressure value of the condenser and the second pressure value of the evaporator includes:

[0084] obtaining a preset oil temperature;

[0085] If the duration for which the oil temperature overheating degree is higher than the preset oil temperature reaches a first preset time length, the first pressure value of the condenser and the second pressure value of the evaporator are obtained.

[0086] The preset oil temperature is set by a designer according to the actual situation of the compressor model, and is not specifically limited here. The first preset time length is, for example, 30s-60s, and can also be set to be longer, and is not specifically limited here. The duration for which the oil temperature overheating degree is stably higher than the preset oil temperature reaches the first preset time length, indicating that the oil temperature overheating degree of the current compressor is sufficient to ensure stable operation of the compressor and ensure the reliability of the air conditioner operation.

[0087] In some embodiments, the air conditioner further includes a flow inducer for guiding hot air to the compressor to warm up the compressor, and before the air conditioner operates in the low-temperature mode, the air conditioner further includes:

[0088] obtaining a first shutdown time length of the compressor this time when it is detected that the outdoor temperature is lower than a preset temperature;

[0089] If the first shutdown time length is greater than a preset shutdown time length, the flow inducer is turned on.

[0090] The first shutdown time length of the compressor this time refers to the time length between the power-on of the air conditioner and the last shutdown of the compressor before the power-on. The first shutdown time length being greater than the preset shutdown time length indicates that the shutdown time length of the compressor this time is longer, and the oil temperature of the compressor in the low-temperature environment can be in a lower state, so that the compressor is preheated by the flow inducer to ensure that the compressor can be normally started. The preset shutdown time length can be two hours.

[0091] It should be noted that if the outdoor temperature is higher than or equal to the preset temperature, the air conditioner operates in the normal-temperature mode. The preset temperature can be 10℃.

[0092] In some embodiments, after the opening of the flow inducer, if the oil temperature overheating degree reaches a preset condition, the flow inducer is closed. In other embodiments, the flow inducer can also be controlled to be closed after being opened for a preset time length.

[0093] Further, in order to facilitate understanding of the control method of the air conditioner of the present application, a more specific embodiment is provided. Referring to Figure 2 , Figure 2 A second flow chart of the control method of the air conditioner provided by the embodiment of the present application is provided. The control method of the air conditioner comprises the following steps S201-S218:

[0094] Step S201: After the air conditioner is powered on, the outdoor temperature is detected.

[0095] Step S202: It is judged whether the outdoor temperature is lower than a preset temperature.

[0096] If the outdoor temperature is not lower than the preset temperature, the following step S203 is executed; otherwise, the following step S204 is executed.

[0097] Step S203: The air conditioner is controlled to run in a normal temperature mode.

[0098] Step S204: The first shutdown time length of the current shutdown of the compressor is obtained.

[0099] Step S205: It is judged whether the first shutdown time length is greater than a preset shutdown time length.

[0100] If the first shutdown time length is greater than the preset shutdown time length, the following step S206 is executed; otherwise, the following step S207 is executed.

[0101] Step S206: The flow inducer is opened.

[0102] Step S207: The air conditioner is controlled to run in a low temperature mode.

[0103] Step S208: After the air conditioner is stably running for 10 minutes, the oil temperature overheating degree of the compressor is monitored.

[0104] Step S209: It is judged whether the oil temperature overheating degree is monitored to be higher than a preset oil temperature for a continuous time length of 30 seconds within a first preset time length.

[0105] The preset oil temperature is, for example, 5℃. If the oil temperature overheating degree is not monitored to be higher than the preset oil temperature for a continuous time length of 30 seconds, the following steps S210-S211 are executed; otherwise, the following step S213 is executed.

[0106] Step S210: The electric heater is turned on, and the power of the flow inducer is increased.

[0107] Step S211: judging whether the duration of the oil temperature overheating degree higher than the preset oil temperature is detected for 30 seconds within the preset period length;

[0108] If the duration of the oil temperature overheating degree higher than the preset oil temperature is not detected for 30 seconds, the following step S212 is performed, otherwise the following step S213 is performed.

[0109] Step S212: increasing the power of the electric heater and the flow inducer;

[0110] After the power of the electric heater and the flow inducer is increased, the above step S211 is returned.

[0111] Step S213: turning off the flow inducer and the electric heater, and obtaining the first pressure value of the condenser and the second pressure value of the evaporator;

[0112] Step S214: judging whether the first pressure value is lower than the preset high pressure threshold;

[0113] If the first pressure value is lower than the preset high pressure threshold, the following step S215 is performed, otherwise the following step S218 is performed.

[0114] Step S215: judging whether the second pressure value is higher than the preset low pressure threshold;

[0115] If the second pressure value is higher than the preset low pressure threshold, the following step S216 is performed, otherwise the following step S217 is performed.

[0116] Step S216: subtracting the preset pressure value from the preset high pressure threshold to obtain an adjusted preset high pressure threshold, and controlling the external fan according to the comparison relationship between the adjusted preset high pressure threshold and the actual pressure value of the condenser.

[0117] For example, if the actual pressure value of the condenser is lower than the adjusted preset high pressure threshold, the external fan is controlled to stop, otherwise the external fan is controlled to maintain the current running state.

[0118] Step S217: controlling the air conditioner to stop and alarm;

[0119] Step S218: the air conditioner normally runs.

[0120] After the flow enters step S218, it returns to step S209 after a preset time period, for example, 10 minutes.

[0121] The control method of the air conditioner provided by the embodiment of the application can intelligently adjust the preset high pressure threshold according to the condensing pressure and the evaporating pressure in the low temperature mode of the air conditioner, can prolong the period of the condensing pressure reaching the stop point pressure value of the external fan in the low temperature, and can avoid the frequent start and stop of the external fan and prevent the large pressure fluctuation in the refrigeration system.

[0122] The embodiment of the present application further provides a control device of an air conditioner, and an example is shown in Figure 3 , Figure 3 The control device of the air conditioner provided by the embodiment of the present application is shown in a structural schematic diagram. The control device 300 comprises:

[0123] The detection module 301 is configured to detect an oil temperature overheat degree of the compressor when the air conditioner operates in a low-temperature mode.

[0124] The acquisition module 302 is configured to acquire a first pressure value of the condenser and a second pressure value of the evaporator if the oil temperature overheat degree reaches a preset condition.

[0125] The calculation module 303 is configured to reduce the preset high-pressure threshold value to obtain an adjusted preset high-pressure threshold value if the first pressure value is lower than a preset high-pressure threshold value and the second pressure value is higher than a preset low-pressure threshold value.

[0126] The control module 304 is configured to control the external fan according to a comparison relationship between the adjusted preset high-pressure threshold value and an actual pressure value of the condenser.

[0127] The control device 300 of the air conditioner provided by the embodiment of the present application can intelligently adjust the preset high-pressure threshold value according to the condensing pressure and the evaporating pressure in the low-temperature mode of the air conditioner, can prolong the period in which the condensing pressure reaches the shutdown point pressure value of the external fan in the low temperature, and can avoid frequent start-stop of the external fan and prevent large pressure fluctuation in the refrigeration system.

[0128] The embodiment of the present application further provides an air conditioner, and an example is shown in Figure 4 , Figure 4 The air conditioner provided by the embodiment of the present application is shown in a structural schematic diagram. The air conditioner 400 comprises a refrigeration cycle system 410, an external fan 420 and a controller 430.

[0129] The refrigeration cycle system 410 comprises a compressor 411, a condenser 412 and an evaporator 413. The external fan 420 is configured to dissipate heat of the condenser 412. The controller 430 is configured to detect an oil temperature overheat degree of the compressor 411 when the air conditioner 400 operates in a low-temperature mode, acquire a first pressure value of the condenser 412 and a second pressure value of the evaporator 413 if the oil temperature overheat degree reaches a preset condition, reduce a preset high-pressure threshold value to obtain an adjusted preset high-pressure threshold value if the first pressure value is lower than the preset high-pressure threshold value and the second pressure value is higher than a preset low-pressure threshold value, and control the external fan 420 according to a comparison relationship between the adjusted preset high-pressure threshold value and an actual pressure value of the condenser 412.

[0130] Further, please refer to Figure 5 , Figure 5Another structure of the air conditioner is provided in the embodiment. The air conditioner 400 is a large air conditioner unit. The refrigeration cycle system 410 includes a compressor 411, a condenser 412, an evaporator 413, and a capillary tube 414. The air conditioner 400 further includes an electric heater 440, a flow guide 450, a high-pressure sensor 461, a low-pressure sensor 462, a partition 470, an indoor fan 480, an outdoor temperature sensor 491, an exhaust temperature sensor 492, and an oil temperature sensor 493.

[0131] In the refrigeration cycle system 410, high-temperature gaseous refrigerant enters the condenser 412 from the compressor 411, becomes normal-temperature liquid refrigerant after passing through the condenser 412, becomes low-temperature liquid refrigerant in two-phase state after throttling through the capillary tube 414, and enters the evaporator 413. After heat exchange with the evaporator 413, the low-temperature liquid refrigerant becomes superheated gas, and the gaseous refrigerant flows into the compressor 411 to become high-temperature gaseous refrigerant, and the cycle is repeated.

[0132] The indoor circulation air system of the air conditioner 400 includes that indoor hot air flows to the evaporator 413 through the intermediate partition 470 by the indoor fan 480, and the cold air is blown into the room for air conditioning.

[0133] The outdoor circulation air system of the air conditioner 400 includes that outdoor cold air enters through the intermediate partition 470 by the outdoor fan 420, and the hot air is blown to the outside after heat dissipation.

[0134] The electric heater 440 and the flow guide 450 are used for preheating the compressor 411 in a low-temperature environment. The high-pressure sensor 461 is used for detecting the first pressure value in the control method, and the low-pressure sensor 462 is used for detecting the second pressure value in the control method. The outdoor temperature sensor 491 is used for obtaining the outdoor temperature. The exhaust temperature sensor 492 is used for detecting the compressor exhaust temperature. The oil temperature sensor 493 is used for detecting the oil temperature of the compressor 411, and then obtaining the oil temperature superheat of the compressor 411.

[0135] The control device 300 of the air conditioner provided in the embodiment can intelligently adjust the preset high-pressure threshold value according to the condensing pressure and the evaporation pressure in the low-temperature mode of the air conditioner, can prolong the period in which the condensing pressure reaches the stop point pressure value of the outdoor fan in a low-temperature environment, avoids frequent start and stop of the outdoor fan 420, and prevents large pressure fluctuation in the refrigeration system.

[0136] The embodiment further provides a storage medium having a computer program stored thereon, and the computer program performs the control method of the air conditioner when running.

[0137] The control method of the air conditioner, the air conditioner and the storage medium provided by the embodiments of the application are described in detail above, and the principles and implementation manners of the application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the application and its core idea; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manners and application ranges will be changed, and the above description of the embodiments should not be understood as a limitation on the application.

Claims

1. A control method of an air conditioner, characterized by, The air conditioner comprises a refrigeration cycle system and an external fan, the refrigeration cycle system comprises a compressor, a condenser and an evaporator, the external fan is used for heat dissipation of the condenser, and the control method comprises: When the air conditioner operates in a low-temperature mode, detecting an oil temperature overheat degree of the compressor; If the oil temperature overheat degree reaches a preset condition, obtaining a first pressure value of the condenser and a second pressure value of the evaporator; If the first pressure value is lower than a preset high pressure threshold value, and the second pressure value is higher than a preset low pressure threshold value, reducing the preset high pressure threshold value to obtain an adjusted preset high pressure threshold value; Controlling the external fan according to a comparison relationship between the adjusted preset high pressure threshold value and an actual pressure value of the condenser.

2. The control method of the air conditioner according to claim 1, characterized by, The air conditioner further comprises an electric heater, and after the detection of the oil temperature overheat degree of the compressor, the method further comprises: If the oil temperature overheat degree does not reach the preset condition, controlling the electric heater to preheat the compressor until the oil temperature overheat degree reaches the preset condition is detected.

3. The control method of the air conditioner according to claim 2, characterized by, The control of the electric heater to preheat the compressor until the oil temperature overheat degree reaches the preset condition comprises: Turning on the electric heater; If the oil temperature overheat degree still does not reach the preset condition after waiting for a second preset time length, increasing the heating power of the electric heater by a first preset period until the oil temperature overheat degree reaches the preset condition is detected; Turning off the electric heater.

4. The control method of an air conditioner according to any one of claims 1 to 3, characterized by, The obtaining of the first pressure value of the condenser and the second pressure value of the evaporator if the oil temperature overheat degree reaches the preset condition comprises: Obtaining a preset oil temperature; If the oil temperature overheat degree is higher than the preset oil temperature for a first preset time length, obtaining the first pressure value of the condenser and the second pressure value of the evaporator.

5. The control method of an air conditioner according to any one of claims 1 to 3, characterized by, The control of the external fan according to the comparison relationship between the adjusted preset high pressure threshold value and the actual pressure value of the condenser further comprises: If the actual pressure value of the condenser is lower than the adjusted preset high pressure threshold value, controlling the external fan to stop.

6. The control method of the air conditioner according to any one of claims 1 to 3, characterized by, Further comprising: If the first pressure value is higher than or equal to a preset high pressure threshold value, maintaining the current preset high pressure threshold value to continue the comparison relationship with the actual pressure value of the condenser to control the compressor to stop; If the first pressure value is lower than a preset high pressure threshold value, and the second pressure value is lower than or equal to a preset low pressure threshold value, controlling the air conditioner to stop operating and issuing an alarm.

7. The control method of the air conditioner according to any one of claims 1 to 3, characterized by, The air conditioner further comprises a flow inducer, the flow inducer is used for guiding hot air to the compressor to warm up the compressor, and before the air conditioner operates in the low-temperature mode, the method further comprises: When detecting that an outdoor temperature is lower than a preset temperature, obtaining a first shutdown time length of the current shutdown of the compressor; If the first shutdown time length is greater than a preset shutdown time length, turning on the flow inducer.

8. The control method of the air conditioner according to claim 7, characterized by, After the turning on of the flow inducer, the method further comprises: If the oil temperature overheat degree reaches the preset condition, turning off the flow inducer.

9. An air conditioner characterized by comprising: Comprising: A refrigeration cycle system comprising a compressor, a condenser and an evaporator; An external fan used for heat dissipation of the condenser; A controller used for: detecting an oil temperature superheat degree of the compressor when the air conditioner operates in a low-temperature mode; if the oil temperature superheat degree reaches a preset condition, obtaining a first pressure value of the condenser and a second pressure value of the evaporator; if the first pressure value is lower than a preset high pressure threshold value and the second pressure value is higher than a preset low pressure threshold value, decreasing the preset high pressure threshold value to obtain an adjusted preset high pressure threshold value; controlling the external fan according to a comparison relationship between the adjusted preset high pressure threshold value and an actual pressure value of the condenser.

10. A storage medium, characterized by a computer program is stored thereon, and the computer program, when executed, performs the control method of the air conditioner of any one of claims 1-8.

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