Low-temperature refrigeration control methods, devices, air conditioners, and computer-readable storage media

Abstract

This application provides a low-temperature refrigeration control method, apparatus, air conditioner, and computer-readable storage medium for controlling an air conditioner. The air conditioner includes a compressor, an expansion valve, an outdoor fan, and an indoor heat exchanger. The low-temperature refrigeration control method includes: controlling the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree; increasing or decreasing the speed of the outdoor fan according to the current temperature and stable evaporation critical temperature of the indoor heat exchanger until the outdoor fan speed reaches its maximum or minimum speed; after the outdoor fan speed reaches its maximum or minimum speed, adjusting the opening degree of the expansion valve according to the temperature of the indoor heat exchanger and a stable evaporation temperature range, so that the temperature of the indoor heat exchanger is adjusted to be within the stable evaporation temperature range, wherein the stable evaporation temperature range is a temperature range greater than the stable evaporation critical temperature and less than a second preset temperature.

Description

Technical Field

[0001] This application relates to the field of air conditioner technology, specifically to a low-temperature refrigeration control method, device, air conditioner, and computer-readable storage medium. Background Technology

[0002] In environments where outdoor temperatures are below zero or even as low as -15°C, the ambient temperature in enclosed indoor spaces such as conference rooms, kitchens, or computer rooms, where it is inconvenient to open windows for ventilation, remains relatively high. Therefore, air conditioners installed in such enclosed indoor spaces have a need for cooling operation.

[0003] When an air conditioner is operating at low temperatures, the indoor heat exchanger is prone to frosting and malfunctions. To address this, relevant technologies often employ methods such as reducing the speed of the outdoor fan or even shutting it down to decrease the heat exchange capacity of the air conditioner, thereby increasing the condensing pressure and evaporating temperature, and thus preventing frosting from forming on the indoor heat exchanger.

[0004] However, after the outdoor fan reduces its speed or stops, the temperature of the indoor heat exchanger can easily drop rapidly below the anti-freeze protection temperature within a short period of time, triggering the anti-freeze protection mechanism and causing the air conditioner to shut down. Therefore, the air conditioners and their outdoor fans in the related technologies suffer from the technical problem of frequent shutdowns leading to unstable operation and low cooling performance. Summary of the Invention

[0005] This application provides a low-temperature refrigeration control method, device, air conditioner, and computer-readable storage medium, which enables the air conditioner to maintain stable refrigeration operation in low-temperature environments, avoids frequent shutdowns of the air conditioner and its outdoor fan, and significantly improves the low-temperature refrigeration performance of the air conditioner.

[0006] In a first aspect, embodiments of this application provide a low-temperature refrigeration control method for controlling an air conditioner, the air conditioner including a compressor, an expansion valve, an outdoor fan, and an indoor heat exchanger. The low-temperature refrigeration control method includes: controlling the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree; increasing or decreasing the rotational speed of the outdoor fan according to the current temperature and stable evaporation critical temperature of the indoor heat exchanger until the rotational speed of the outdoor fan reaches its maximum or minimum speed; after the rotational speed of the outdoor fan reaches its maximum or minimum speed, adjusting the opening degree of the expansion valve according to the temperature of the indoor heat exchanger and a stable evaporation temperature range, so that the temperature of the indoor heat exchanger is adjusted to be within the stable evaporation temperature range, the stable evaporation temperature range being a temperature range greater than the stable evaporation critical temperature and less than a second preset temperature.

[0007] In some embodiments, the rotational speed of the outdoor fan is increased or decreased based on the current temperature of the indoor heat exchanger and the stable evaporation critical temperature until the outdoor fan reaches its maximum or minimum speed. This includes: determining whether the current rotational speed of the outdoor fan is the maximum or minimum speed; when the current rotational speed of the outdoor fan is determined to be the maximum or minimum speed, controlling the outdoor fan to maintain operation at the current speed; when the current rotational speed of the outdoor fan is determined not to be the maximum or minimum speed, determining whether the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature; when the current temperature of the indoor heat exchanger is determined to be greater than the stable evaporation critical temperature, increasing the rotational speed of the outdoor fan by a preset increase margin; and when the current temperature of the indoor heat exchanger is determined to be less than or equal to the stable evaporation critical temperature, decreasing the rotational speed of the outdoor fan by a preset decrease margin.

[0008] In some embodiments, adjusting the opening of the expansion valve according to the temperature of the indoor heat exchanger and a stable evaporation temperature range to adjust the temperature of the indoor heat exchanger to within the stable evaporation temperature range includes: determining whether the current temperature of the indoor heat exchanger is within the stable evaporation temperature range, wherein the stable evaporation temperature range is a temperature range greater than the stable evaporation critical temperature and less than a second preset temperature; stopping the adjustment of the opening of the expansion valve when it is determined that the current temperature of the indoor heat exchanger is within the stable evaporation temperature range; increasing the opening of the expansion valve by a first opening adjustment amount every preset time interval when it is determined that the current temperature of the indoor heat exchanger is less than or equal to the stable evaporation critical temperature; and decreasing the opening of the expansion valve by a second opening adjustment amount every preset time interval when it is determined that the current temperature of the indoor heat exchanger is greater than or equal to the second preset temperature.

[0009] In some embodiments, before adjusting the opening of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range, the low-temperature refrigeration control method includes: obtaining a preset range width of the stable evaporation temperature range; determining a second preset temperature according to the stable evaporation critical temperature and the preset range width; and determining the stable evaporation temperature range according to the stable evaporation critical temperature and the second preset temperature.

[0010] In some embodiments, controlling the compressor to operate at a preset low-temperature cooling frequency and the expansion valve to operate at a preset low-temperature cooling opening degree includes: acquiring the current outdoor temperature; and determining the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve based on the current outdoor temperature.

[0011] In some embodiments, determining the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve based on the current outdoor temperature includes: determining the temperature range in which the current outdoor temperature is located; and determining the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve based on the temperature range in which the current outdoor temperature is located.

[0012] In some embodiments, the preset low-temperature cooling frequency is positively correlated with the current outdoor temperature, and the preset low-temperature cooling setting is negatively correlated with the current outdoor temperature.

[0013] Secondly, embodiments of this application provide a low-temperature refrigeration control device for controlling an air conditioner. The air conditioner includes a compressor, an expansion valve, an outdoor fan, and an indoor heat exchanger. The low-temperature refrigeration control device includes: a fixed operation module configured to control the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree; a speed adjustment module configured to increase or decrease the speed of the outdoor fan according to the current temperature and stable evaporation critical temperature of the indoor heat exchanger until the speed of the outdoor fan reaches the maximum speed or the minimum speed; and an opening degree adjustment module configured to adjust the opening degree of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range after the speed of the outdoor fan reaches the maximum speed or the minimum speed, so that the temperature of the indoor heat exchanger is adjusted to within the stable evaporation temperature range.

[0014] Thirdly, embodiments of this application provide an air conditioner, including: a compressor; an expansion valve; an outdoor fan; an outdoor heat exchanger; a processor; and a memory storing a computer program, wherein when the computer program is executed by the processor, it implements the low-temperature refrigeration control method as described in any of the above embodiments.

[0015] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to execute the steps in the cryogenic refrigeration control method described above.

[0016] The low-temperature refrigeration control method provided in this application first controls the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree. At the same time, based on the current temperature of the indoor heat exchanger and the stable evaporation critical temperature, the speed of the outdoor fan is continuously increased or decreased to the maximum or minimum speed. Subsequently, based on the temperature of the indoor heat exchanger and the stable evaporation temperature range, the opening degree of the expansion valve is adjusted so that the temperature of the indoor heat exchanger is adjusted to within the stable evaporation temperature range. This avoids the risk of frost and freezing of the indoor heat exchanger due to the temperature being lower than the stable evaporation critical temperature, and also avoids insufficient evaporation performance of the indoor heat exchanger due to the temperature being higher than the second preset temperature. Moreover, the outdoor fan does not need to stop running and will not trigger the anti-freeze protection mechanism. This allows the air conditioner to maintain stable refrigeration operation in low-temperature environments, avoids frequent shutdowns of the air conditioner and its outdoor fan, and significantly improves the low-temperature refrigeration performance of the air conditioner. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a cryogenic refrigeration control method provided in some embodiments of this application; Figure 2 This is a partial flowchart of a cryogenic refrigeration control method provided in some embodiments of this application; Figure 3 This is another partial flowchart of a cryogenic refrigeration control method provided in some embodiments of this application; Figure 4 This is another partial flowchart of a cryogenic refrigeration control method provided in some embodiments of this application; Figure 5 This is another partial flowchart of a cryogenic refrigeration control method provided in some embodiments of this application; Figure 6 This is a structural diagram of an air conditioner provided in some embodiments of this application.

[0019] Explanation of key component symbols: 1-Air conditioner, 10-Processor, 20-Memory. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0023] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0024] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0025] like Figure 1 As shown, in a first aspect, embodiments of this application provide a low-temperature refrigeration control method for controlling an air conditioner 1. The low-temperature refrigeration control method includes S10 to S30, which enables the air conditioner 1 to maintain stable refrigeration operation in a low-temperature environment, avoids frequent shutdowns of the air conditioner 1 and its outdoor fan, and significantly improves the low-temperature refrigeration performance of the air conditioner 1.

[0026] The air conditioner 1 includes a compressor, an expansion valve, an outdoor fan, and an indoor heat exchanger. The type of air conditioner 1 can be determined according to actual needs, and can be different types such as wall-mounted air conditioners, cabinet air conditioners, window air conditioners, ceiling-mounted air conditioners, etc. This application embodiment does not limit this.

[0027] S10: Controls the compressor to operate at the preset low-temperature refrigeration frequency and the expansion valve to operate at the preset low-temperature refrigeration opening degree.

[0028] Here, the preset low-temperature cooling frequency is the compressor frequency preset for the low-temperature cooling mode, and the preset low-temperature cooling opening is the expansion valve opening preset for the low-temperature cooling mode. After the air conditioner 1 enters the low-temperature cooling mode, it controls the compressor to start at the preset low-temperature cooling frequency and maintains operation at this preset low-temperature cooling frequency as a fixed frequency after starting. It also controls the expansion valve to start at the preset low-temperature cooling opening and maintain operation at this preset low-temperature cooling opening as a fixed opening after starting. It should be noted that in S20 and S30 described later, the compressor still maintains operation at the preset low-temperature cooling frequency as a fixed frequency without frequency adjustment; and in S20 described later, the expansion valve still maintains operation at the preset low-temperature cooling opening as a fixed opening without opening adjustment.

[0029] S20: Based on the current temperature of the indoor heat exchanger and the critical temperature for stable evaporation, increase or decrease the speed of the outdoor fan until the outdoor fan reaches its maximum or minimum speed.

[0030] Here, the current temperature of the indoor heat exchanger can be acquired in real time by a temperature sensor installed on the indoor heat exchanger, or determined based on the pressure of the indoor heat exchanger. The stable evaporation critical temperature of the indoor heat exchanger is the temperature required for the indoor heat exchanger to achieve stable evaporation operation when the air conditioner 1 is cooling at low temperatures in the current indoor and outdoor environments. In some embodiments, when the temperature of the indoor heat exchanger is higher than the stable evaporation critical temperature, the indoor heat exchanger will not freeze and can maintain stable evaporation operation; when the temperature of the indoor heat exchanger is lower than or equal to the stable evaporation critical temperature, the indoor heat exchanger may be at risk of freezing. In some examples, the stable evaporation critical temperature can be taken between 0 and 2°C.

[0031] After air conditioner 1 enters the low-temperature cooling mode, the outdoor fan starts operating at a preset starting speed. After the outdoor fan starts, its speed is continuously adjusted based on the relationship between the current temperature of the indoor heat exchanger and the stable evaporation critical temperature, until the outdoor fan reaches its maximum or minimum speed. In other words, regardless of whether the current temperature of the indoor heat exchanger is greater than or less than the stable evaporation critical temperature, the outdoor fan speed must be changed, gradually increasing or decreasing until it reaches its maximum or minimum speed. It should be noted that the method of increasing or decreasing the outdoor fan speed when the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature differs from the method when the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature; in one case, the speed increases, and in the other case, it decreases.

[0032] In some embodiments, the outdoor fan may be equipped with multiple wind speeds. Correspondingly, the rotational speed of the outdoor fan is the wind speed setting, the maximum rotational speed is the maximum wind speed setting, and the minimum rotational speed is the minimum wind speed setting. When it is necessary to increase or decrease the rotational speed of the outdoor fan, the wind speed setting can be increased or decreased until the wind speed setting of the outdoor fan reaches the maximum or minimum wind speed setting.

[0033] S30: After the outdoor fan reaches its maximum or minimum speed, adjust the opening of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range so that the temperature of the indoor heat exchanger is adjusted to the stable evaporation temperature range.

[0034] The stable evaporation temperature range is defined as the temperature range above the stable evaporation critical temperature and below the second preset temperature, where the second preset temperature is above the stable evaporation critical temperature. After setting the stable evaporation temperature range, the target temperature of the indoor heat exchanger can be limited within this range. Based on this control target, the opening of the expansion valve can be reliably controlled, ensuring that the indoor heat exchanger can operate stably in an evaporation state. This avoids the risk of frost and freezing due to the indoor heat exchanger being below the stable evaporation critical temperature, and also avoids insufficient evaporation performance due to the indoor heat exchanger being above the second preset temperature, ensuring that the indoor heat exchanger can effectively and stably reduce the indoor air temperature.

[0035] After the outdoor fan reaches its maximum or minimum speed, the outdoor fan is controlled in S30 to maintain its current speed, i.e., operate at the reached maximum or minimum speed, to prevent the outdoor fan from stopping. Simultaneously, the opening of the expansion valve is adjusted according to the temperature of the indoor heat exchanger and its stable evaporation temperature range, so that the temperature of the indoor heat exchanger is regulated to within the stable evaporation temperature range. In other words, when the temperature of the indoor heat exchanger is outside the stable evaporation temperature range, the opening of the expansion valve needs to be adjusted to change the temperature of the indoor heat exchanger, gradually regulating it to within the stable evaporation temperature range; when the temperature of the indoor heat exchanger is within the stable evaporation temperature range, the opening of the expansion valve does not need to be adjusted, maintaining its current opening to keep the temperature of the indoor heat exchanger within the stable evaporation temperature range.

[0036] Compared with related technologies, the low-temperature refrigeration control method provided in this application first controls the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening. At the same time, based on the current temperature of the indoor heat exchanger and the stable evaporation critical temperature, the speed of the outdoor fan is continuously increased or decreased to the maximum or minimum speed. Then, based on the temperature of the indoor heat exchanger and the stable evaporation temperature range, the opening of the expansion valve is adjusted so that the temperature of the indoor heat exchanger is adjusted to within the stable evaporation temperature range. This can avoid the risk of frost and freezing of the indoor heat exchanger due to the temperature being lower than the stable evaporation critical temperature, and can also avoid insufficient evaporation performance of the indoor heat exchanger due to the temperature being higher than the second preset temperature. Moreover, the outdoor fan does not need to stop running and will not trigger the anti-freeze protection mechanism. This allows the air conditioner 1 to maintain stable refrigeration operation in low-temperature environments, avoids frequent shutdowns of the air conditioner 1 and its outdoor fan, and significantly improves the low-temperature refrigeration performance of the air conditioner 1.

[0037] like Figure 2 As shown, in some embodiments, S10 may include S11 to S12.

[0038] S11: Get the current outdoor temperature.

[0039] Here, the current outdoor temperature can be collected in real time by a temperature sensor installed on the outdoor side, or it can be obtained from local meteorological information through a communication network.

[0040] S12: Determine the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve based on the current outdoor temperature.

[0041] The correspondence between outdoor temperature and compressor operating frequency in low-temperature cooling mode, as well as the correspondence between outdoor temperature and expansion valve opening in low-temperature cooling mode, can be predetermined using experimental test data or historical operating data. Thus, after obtaining the current outdoor temperature, the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening of the expansion valve can be determined based on the aforementioned correspondences.

[0042] like Figure 3 As shown, in some examples, S12 may include S121~S122.

[0043] S121: Determine the current outdoor temperature range.

[0044] S122: Determine the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve based on the current outdoor temperature range.

[0045] Here, multiple continuously distributed temperature ranges can be preset, each temperature range corresponding to a preset compressor frequency value and expansion valve opening value. For example, the multiple temperature ranges may include a first temperature range, a second temperature range, and a third temperature range. The first temperature range is the temperature range below a first outer ambient temperature threshold, the second temperature range is the temperature range greater than or equal to the first outer ambient temperature threshold and less than the second outer ambient temperature threshold, and the third temperature range is the temperature range greater than or equal to the second outer ambient temperature threshold and less than the third outer ambient temperature threshold. The first outer ambient temperature threshold is less than the second outer ambient temperature threshold, and the second outer ambient temperature threshold is less than the third outer ambient temperature threshold. The values ​​of the first, second, and third outer ambient temperature thresholds can be determined according to actual needs, and this application embodiment does not limit this. For example, the first outer ambient temperature threshold can be -5℃, the second outer ambient temperature threshold can be 5℃, and the third outer ambient temperature threshold can be 15℃.

[0046] After obtaining the current outdoor temperature, the temperature range in which the current outdoor temperature falls can be determined. Then, the compressor frequency value and expansion valve opening value corresponding to the temperature range can be retrieved and determined. The compressor frequency value is used as the preset low-temperature cooling frequency, and the expansion valve opening value is used as the preset low-temperature cooling opening.

[0047] In some examples, in low-temperature cooling mode, the compressor's operating frequency (i.e., the preset low-temperature cooling frequency) can be positively correlated with the outdoor temperature, while the expansion valve opening (i.e., the preset low-temperature cooling opening) can be negatively correlated with the outdoor temperature. That is, when the outdoor temperature is low, the compressor's operating frequency is low, while the expansion valve opening is large; when the outdoor temperature is high, the compressor's operating frequency is high, while the expansion valve opening is small. For example, the compressor frequency value corresponding to the first temperature range is lower than the compressor frequency value and expansion valve opening value corresponding to the second temperature range, the compressor frequency value corresponding to the second temperature range is lower than the compressor frequency value corresponding to the third temperature range, the expansion valve opening value corresponding to the first temperature range is greater than the expansion valve opening value corresponding to the second temperature range, and the expansion valve opening value corresponding to the second temperature range is greater than the expansion valve opening value corresponding to the third temperature range. This avoids excessively low condensing pressure, ensuring that air conditioner 1 can maintain normal operation in low-temperature environments.

[0048] like Figure 4 As shown, in some embodiments, S20 may include S21 to S25.

[0049] S21: Determine whether the current speed of the outdoor fan is the maximum or minimum speed.

[0050] S22: When the current speed of the outdoor fan is determined to be the maximum speed or the minimum speed, control the outdoor fan to maintain operation at the current speed.

[0051] When the current speed of the outdoor fan is determined to be either the maximum or minimum speed, it can be determined that the speed of the outdoor fan can no longer be increased or decreased. At this time, the outdoor fan can be controlled to maintain operation at the current speed, and S30 can be performed. In other words, when the current speed of the outdoor fan is the maximum speed, the outdoor fan is controlled to maintain operation at the maximum speed; when the current speed of the outdoor fan is the minimum speed, the outdoor fan is controlled to maintain operation at the minimum speed.

[0052] S23: When it is determined that the current speed of the outdoor fan is not the maximum or minimum speed, determine whether the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature.

[0053] When it is determined that the current speed of the outdoor fan is not its maximum or minimum speed, it can be determined that the speed of the outdoor fan can continue to increase or decrease. At this point, the relationship between the current temperature of the indoor heat exchanger and the stable evaporation critical temperature can be determined to determine the direction of increase or decrease in the outdoor fan speed, which includes either increase or decrease. Here, when the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature, the direction of increase or decrease in the outdoor fan speed is increase; when the current temperature of the indoor heat exchanger is less than or equal to the stable evaporation critical temperature, the direction of increase or decrease in the outdoor fan speed is decrease.

[0054] S24: When the current temperature of the indoor heat exchanger is determined to be greater than the critical temperature for stable evaporation, increase the speed of the outdoor fan by the preset speed increase range.

[0055] Here, the preset speed increase range can be a speed increase ratio or a speed increase amount, and the unit of the speed increase amount can be revolutions per minute (rpm). The value of the preset speed increase range can be determined according to actual needs, and this application embodiment does not limit it. When it is determined that the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature, the speed of the outdoor fan is increased according to the preset speed increase range.

[0056] For example, an outdoor fan can have multiple wind speed settings, such as the lowest, second-lowest, second-highest, and highest wind speed settings. Correspondingly, the preset speed increase can be the amount of rotational speed increase, which can be one level. Thus, each time the outdoor fan's rotational speed is increased by the preset speed increase, the fan's speed increases by one level, for example, from the lowest to the second-lowest, or from the second-highest to the highest wind speed.

[0057] Here, S21 and S23 can be executed continuously. As long as the current speed of the outdoor fan has not reached the maximum or minimum speed and the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature, S24 can be executed to increase the speed of the outdoor fan by a preset speed increase range, so that the speed of the outdoor fan is gradually increased to the maximum speed.

[0058] S25: When the current temperature of the indoor heat exchanger is determined to be less than or equal to the critical temperature for stable evaporation, reduce the speed of the outdoor fan by the preset speed reduction range.

[0059] Here, the preset speed reduction range can be a speed reduction percentage or a reduction in rotational speed, with the unit for the reduction in rotational speed being revolutions per minute (rpm). The value of the preset speed reduction range can be determined according to actual needs, and this embodiment does not limit this. When it is determined that the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature, the rotational speed of the outdoor fan is increased according to the preset speed reduction range.

[0060] For example, an outdoor fan can be equipped with multiple wind speed settings, such as the lowest, second-lowest, second-highest, and highest wind speed settings. Correspondingly, the preset speed reduction range can be the amount of speed reduction, which can be one level. Thus, each time the outdoor fan speed is increased by the preset speed reduction range, the outdoor fan speed is reduced by one level, for example, from the second-lowest to the lowest wind speed, or from the highest to the second-highest wind speed.

[0061] Here, S21 and S23 can be executed continuously. As long as the current speed of the outdoor fan has not reached the maximum or minimum speed and the current temperature of the indoor heat exchanger is less than or equal to the stable evaporation critical temperature, S25 can be executed to reduce the speed of the outdoor fan by a preset speed reduction range, so that the speed of the outdoor fan is gradually reduced to the minimum speed.

[0062] The low-temperature refrigeration control method provided in this application embodiment can continuously increase or decrease the speed of the outdoor fan when the current speed of the outdoor fan has not yet reached the maximum or minimum speed by setting S21~S25, so that the speed of the outdoor fan can quickly reach the maximum or minimum speed, and promptly enter S30 after the speed of the outdoor fan reaches the maximum or minimum speed to adjust the opening of the expansion valve.

[0063] like Figure 5 As shown, in some embodiments, S30 may include S31 to S34.

[0064] S31: Determine whether the current temperature of the indoor heat exchanger is within the stable evaporation temperature range.

[0065] S32: When the current temperature of the indoor heat exchanger is determined to be within the stable evaporation temperature range, stop adjusting the opening of the expansion valve.

[0066] S33: When the current temperature of the indoor heat exchanger is determined to be less than or equal to the stable evaporation critical temperature, the opening of the expansion valve is increased by the first opening adjustment amount every preset time interval.

[0067] Here, the preset time interval is an adjustment interval pre-set based on the operating characteristics of the expansion valve in low-temperature refrigeration mode, and the first opening adjustment amount is an opening adjustment amount pre-set based on the operating characteristics of the expansion valve in low-temperature refrigeration mode. When it is determined that the current temperature of the indoor heat exchanger is less than or equal to the stable evaporation critical temperature, the opening of the expansion valve can be increased by the first opening adjustment amount; after increasing the opening of the expansion valve, the expansion valve is controlled to operate at the increased opening until the preset time interval, and the current temperature of the indoor heat exchanger is re-determined whether it is within the stable evaporation temperature range; when it is determined that the current temperature of the indoor heat exchanger is still less than or equal to the stable evaporation critical temperature, the opening of the expansion valve is increased again by the first opening adjustment amount. This cycle of adjustment continues until the current temperature of the indoor heat exchanger is within the stable evaporation temperature range.

[0068] S34: When the current temperature of the indoor heat exchanger is determined to be greater than or equal to the second preset temperature, the opening of the expansion valve is reduced by the second opening adjustment amount every preset time interval.

[0069] Here, the second opening adjustment amount is a preset opening adjustment amount based on the operating characteristics of the expansion valve in low-temperature refrigeration mode. When it is determined that the current temperature of the indoor heat exchanger is greater than or equal to the second preset temperature, the opening of the expansion valve can be reduced by the second opening adjustment amount. After reducing the opening of the expansion valve, the expansion valve is controlled to operate at the reduced opening for a preset time interval, and the current temperature of the indoor heat exchanger is re-determined to see if it is within the stable evaporation temperature range. When it is determined that the current temperature of the indoor heat exchanger is still greater than or equal to the second preset temperature, the opening of the expansion valve is reduced again by the second opening adjustment amount. This cycle is repeated until the current temperature of the indoor heat exchanger is within the stable evaporation temperature range.

[0070] The low-temperature refrigeration control method provided in this application embodiment can smoothly adjust the opening of the expansion valve by setting S31~S34, so that the current temperature of the indoor heat exchanger can be reliably maintained within the stable evaporation temperature range.

[0071] In some embodiments, prior to S30, the cryogenic refrigeration control method may include S201 to S203.

[0072] S201: Obtain the preset range width of the stable evaporation temperature range.

[0073] Here, the preset width of the stable evaporation temperature range can be preset according to the operating characteristics of the indoor heat exchanger in low-temperature cooling mode. This is used to maintain the temperature stability of the indoor heat exchanger, avoiding the risk of frost and freezing due to the temperature being below the stable evaporation critical temperature, and preventing insufficient evaporation performance due to the temperature exceeding the second preset temperature. The value of the preset range width can be determined according to actual needs, and this application embodiment does not limit it. In some examples, the preset range width can be 2~3℃, for example, it can be different values ​​such as 2℃, 2.2℃, 2.5℃, 2.7℃, or 3℃.

[0074] S202: Determine the second preset temperature based on the stable evaporation critical temperature and the preset range width.

[0075] Here, the sum of the stable evaporation critical temperature and the preset interval width can be calculated, and the sum is the second preset temperature.

[0076] S203: Determine the stable evaporation temperature range based on the stable evaporation critical temperature and the second preset temperature.

[0077] Secondly, this application provides a low-temperature refrigeration control device for controlling an air conditioner 1. The low-temperature refrigeration control device includes: a fixed operation module configured to control the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree; a speed adjustment module configured to increase or decrease the speed of the outdoor fan according to the current temperature of the indoor heat exchanger and the stable evaporation critical temperature, until the speed of the outdoor fan reaches the maximum speed or the minimum speed; and an opening degree adjustment module configured to adjust the opening degree of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range after the speed of the outdoor fan reaches the maximum speed or the minimum speed, so that the temperature of the indoor heat exchanger is adjusted to within the stable evaporation temperature range.

[0078] like Figure 6 As shown, in a third aspect, embodiments of this application provide an air conditioner 1, which includes a compressor, an expansion valve, an outdoor fan, an outdoor heat exchanger, a processor 10, and a memory 20. The memory 20 stores a computer program, which, when executed by the processor 10, implements the low-temperature refrigeration control method as described in any of the above embodiments. The type of air conditioner 1 can be determined according to actual needs, and can be, for example, a wall-mounted air conditioner, a cabinet air conditioner, a window air conditioner, a ceiling-mounted air conditioner, etc. Embodiments of this application do not limit this type.

[0079] Processor 10 is connected to memory 20 and can perform various actions and processes according to the program stored in memory 20. Specifically, processor 10 can be an integrated circuit chip with signal processing capabilities. The processor 10 can be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), off-the-shelf programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, and can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor, and can be based on x86 architecture or ARM architecture.

[0080] Memory 20 may be volatile or non-volatile, or may include both. Non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct memory bus random access memory (DRRAM). It should be noted that memory 20 of the methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0081] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to execute the steps in the control method of any of the above embodiments.

[0082] For example, the aforementioned computer-readable storage media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., CDs (Compact Disks), DVDs (Digital Versatile Disks), etc.), smart cards, and flash memory devices (e.g., EPROMs (Erasable Programmable Read-Only Memory), cards, sticks, or key drives, etc.). The various computer-readable storage media described in the embodiments of this application may represent one or more devices and / or other machine-readable storage media for storing information. The term "machine-readable storage medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0083] The above provides a detailed description of a cryogenic refrigeration control method, apparatus, air conditioner, and computer-readable storage medium provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A low-temperature refrigeration control method, characterized in that, For controlling an air conditioner, the air conditioner includes a compressor, an expansion valve, an outdoor fan, and an indoor heat exchanger, and the low-temperature refrigeration control method includes: The compressor is controlled to operate at a preset low-temperature refrigeration frequency, and the expansion valve is controlled to operate at a preset low-temperature refrigeration opening degree. Based on the current temperature and stable evaporation critical temperature of the indoor heat exchanger, increase or decrease the speed of the outdoor fan until the speed of the outdoor fan reaches the maximum or minimum speed. After the outdoor fan reaches its maximum or minimum speed, the opening of the expansion valve is adjusted according to the temperature of the indoor heat exchanger and the stable evaporation temperature range, so that the temperature of the indoor heat exchanger is adjusted to be within the stable evaporation temperature range, which is a temperature range that is greater than the stable evaporation critical temperature and less than the second preset temperature.

2. The low-temperature refrigeration control method according to claim 1, characterized in that, Based on the current temperature and stable evaporation critical temperature of the indoor heat exchanger, increase or decrease the speed of the outdoor fan until the outdoor fan reaches its maximum or minimum speed, including: Determine whether the current speed of the outdoor fan is the maximum or minimum speed; When it is determined that the current speed of the outdoor fan is the maximum speed or the minimum speed, the outdoor fan is controlled to maintain operation at the current speed; When it is determined that the current speed of the outdoor fan is not the maximum or minimum speed, determine whether the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature; When it is determined that the current temperature of the indoor heat exchanger is greater than the stable evaporation critical temperature, the speed of the outdoor fan is increased by a preset rate of increase. When the current temperature of the indoor heat exchanger is determined to be less than or equal to the critical temperature for stable evaporation, the speed of the outdoor fan is reduced by a preset reduction margin.

3. The low-temperature refrigeration control method according to claim 1, characterized in that, Adjusting the opening of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range, so that the temperature of the indoor heat exchanger is adjusted to within the stable evaporation temperature range, includes: Determine whether the current temperature of the indoor heat exchanger is within the stable evaporation temperature range; When the current temperature of the indoor heat exchanger is determined to be within the stable evaporation temperature range, the adjustment of the opening of the expansion valve is stopped; When the current temperature of the indoor heat exchanger is determined to be less than or equal to the stable evaporation critical temperature, the opening of the expansion valve is increased by a first opening adjustment amount every preset time interval. When the current temperature of the indoor heat exchanger is determined to be greater than or equal to the second preset temperature, the opening of the expansion valve is reduced by the second opening adjustment amount every preset time interval.

4. The low-temperature refrigeration control method according to claim 1, characterized in that, Before adjusting the opening of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range, the low-temperature refrigeration control method includes: Obtain the preset width of the stable evaporation temperature range; The second preset temperature is determined based on the stable evaporation critical temperature and the preset range width; The stable evaporation temperature range is determined based on the stable evaporation critical temperature and the second preset temperature.

5. The low-temperature refrigeration control method according to claim 1, characterized in that, Controlling the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree includes: Get the current outdoor temperature; Based on the current outdoor temperature, determine the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve.

6. The low-temperature refrigeration control method according to claim 5, characterized in that, Based on the current outdoor temperature, determine the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve, including: Determine the temperature range within which the current outdoor temperature falls; Based on the current outdoor temperature range, determine the preset low-temperature cooling frequency of the compressor and the preset low-temperature cooling opening degree of the expansion valve.

7. The low-temperature refrigeration control method according to claim 5, characterized in that, The preset low-temperature cooling frequency is positively correlated with the current outdoor temperature, and the preset low-temperature cooling setting is negatively correlated with the current outdoor temperature.

8. A low-temperature refrigeration control device, characterized in that, For controlling an air conditioner, the air conditioner includes a compressor, an expansion valve, an outdoor fan, and an indoor heat exchanger, and the low-temperature refrigeration control device includes: The fixed operation module is configured to control the compressor to operate at a preset low-temperature refrigeration frequency and the expansion valve to operate at a preset low-temperature refrigeration opening degree. The speed regulation module is configured to increase or decrease the speed of the outdoor fan according to the current temperature and stable evaporation critical temperature of the indoor heat exchanger, until the speed of the outdoor fan reaches the maximum speed or the minimum speed. The opening adjustment module is configured to adjust the opening of the expansion valve according to the temperature of the indoor heat exchanger and the stable evaporation temperature range after the outdoor fan reaches its maximum or minimum speed, so that the temperature of the indoor heat exchanger is adjusted to within the stable evaporation temperature range.

9. An air conditioner, characterized in that, include: compressor; Expansion valve; Outdoor fan; Outdoor heat exchanger; processor; A memory storing a computer program that, when executed by the processor, implements the cryogenic refrigeration control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, It stores a computer program, which is loaded by a processor to execute the steps of the cryogenic refrigeration control method according to any one of claims 1 to 7.

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