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

Abstract

This invention relates to a control method, a storage medium, and an air conditioner. The air conditioner has multiple outdoor heat exchangers connected in parallel, and the control method includes: acquiring the inlet air temperature and outlet air temperature corresponding to each of the outdoor heat exchangers, and determining the inlet air temperature difference and outlet air temperature difference between every two outdoor heat exchangers; comparing each inlet air temperature difference with a preset inlet air temperature difference, and comparing each outlet air temperature difference with a preset outlet air temperature difference; and controlling the opening degree of the electronic expansion valve corresponding to each outdoor heat exchanger according to a uniform distribution mode or a high-efficiency heat exchange mode based on the comparison results. This invention enables the electronic expansion valve opening control to better conform to actual operating conditions, improves the heat exchange efficiency of the outdoor heat exchangers, and increases the operating efficiency of the air conditioner.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically to a control method for an air conditioner and an air conditioner. Background Technology

[0002] An air conditioner is a device that uses artificial means to regulate and control parameters such as temperature, humidity, and airflow within a space to be regulated in a building or structure. An air conditioner generally consists of an indoor unit located in the space to be regulated and an outdoor unit located in the external environment. The indoor unit typically houses components such as an indoor heat exchanger and an indoor fan; the outdoor unit typically houses components such as a compressor, an outdoor heat exchanger, an outdoor fan, and an expansion unit. The compressor, indoor heat exchanger, expansion unit, and outdoor heat exchanger are connected sequentially via refrigerant piping to form a refrigeration circuit that allows a refrigerant (such as R34A) to circulate within it. Using a four-way valve, the air conditioner can also easily switch the direction of refrigerant flow, thereby switching between heating and cooling modes.

[0003] To improve heat exchange efficiency, existing technologies have developed air conditioners with multiple outdoor heat exchangers, such as two, three, or four. These multiple outdoor heat exchangers are arranged in parallel in the refrigeration system and have independent electronic expansion valves to control the amount of refrigerant in each distribution path. Due to the large size and complex flow paths of the heat exchangers, refrigerant flow deviation occurs between the outdoor heat exchangers (i.e., uneven refrigerant distribution), preventing the outdoor heat exchangers from fully utilizing their heat exchange efficiency and reducing the operating efficiency of the air conditioner.

[0004] To address the aforementioned technical issues, existing air conditioners typically adjust the opening of the corresponding electronic expansion valves based on the pressure difference between each liquid distribution path, thereby ensuring a more consistent amount of refrigerant flowing through each outdoor heat exchanger. However, in practical applications, the varying locations of each outdoor heat exchanger result in different actual operating conditions, rendering the existing control logic inadequate for practical needs.

[0005] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0006] To address or improve to some extent the technical problem that the refrigerant regulation of outdoor heat exchangers in existing air conditioners cannot meet the needs of actual operating conditions, this invention provides a control method for an air conditioner. The air conditioner has multiple outdoor heat exchangers connected in parallel, and the control method includes: acquiring the inlet air temperature and outlet air temperature corresponding to each of the outdoor heat exchangers, and determining the inlet air temperature difference and outlet air temperature difference between every two outdoor heat exchangers; comparing each inlet air temperature difference with a preset inlet air temperature difference, and comparing each outlet air temperature difference with a preset outlet air temperature difference; and based on the comparison results, controlling the opening degree of the electronic expansion valve corresponding to each outdoor heat exchanger to adjust according to a uniform distribution mode or a high-efficiency heat exchange mode.

[0007] In the control method for air conditioners of this invention, the inlet and outlet air temperatures corresponding to each outdoor heat exchanger are first obtained, and the inlet and outlet temperature differences between every two outdoor heat exchangers are determined. Next, each inlet temperature difference is compared with a preset inlet temperature difference, and each outlet temperature difference is also compared with a preset outlet temperature difference. Then, based on the comparison results, the electronic expansion valve corresponding to each outdoor heat exchanger is controlled to adjust its opening degree according to a suitable uniform distribution mode or a high-efficiency heat exchange mode. Therefore, the control method for air conditioners of this invention enables the opening degree control of the electronic expansion valve to better conform to actual operating conditions, improves the heat exchange efficiency of the outdoor heat exchanger, and increases the operating efficiency of the air conditioner.

[0008] In the preferred technical solution for the air conditioner described above, when all the inlet air temperature differences of an outdoor heat exchanger are less than or equal to the preset inlet air temperature difference and all the corresponding outlet air temperature differences are less than or equal to the preset outlet air temperature difference, the corresponding electronic expansion valve is controlled to adjust its opening according to the uniform distribution mode; otherwise, the corresponding electronic expansion valve is controlled to adjust its opening according to the high-efficiency heat exchange mode. When all the inlet air temperature differences of an outdoor heat exchanger are less than or equal to the preset inlet air temperature difference and all the corresponding outlet air temperature differences are also less than or equal to the preset outlet air temperature difference, it indicates that the difference in inlet and outlet air temperatures between this outdoor heat exchanger and other outdoor heat exchangers is small, and the heat exchange efficiency of the outdoor heat exchangers is not significantly different. Therefore, the opening of the corresponding electronic expansion valve is adjusted according to the uniform distribution mode to make the amount of refrigerant flowing through each outdoor heat exchanger more uniform. Otherwise, it indicates that there is a large difference in inlet or outlet air temperature between this outdoor heat exchanger and other outdoor heat exchangers. Therefore, the opening of the corresponding electronic expansion valve is controlled to adjust its opening according to the high-efficiency heat exchange mode to achieve the best heat exchange efficiency of the outdoor heat exchanger.

[0009] In the preferred technical solution for the air conditioner described above, the steps of the uniform distribution mode include: obtaining the pressure difference between the outdoor heat exchanger and the other outdoor heat exchangers; comparing the pressure difference with a preset pressure difference; and adjusting the opening degree of the corresponding electronic expansion valve based on the comparison result between the pressure difference and the preset pressure difference. In the uniform distribution mode, adjusting the opening degree of the corresponding electronic expansion valve based on the pressure difference between the outdoor heat exchanger and the other outdoor heat exchangers can make the amount of refrigerant flowing through each outdoor heat exchanger more uniform, thereby improving heat exchange efficiency.

[0010] In the preferred embodiment of the air conditioner described above, the air conditioner further includes a distribution valve for adjusting the proportion of refrigerant flowing into the plurality of outdoor heat exchangers, and the control method further includes: acquiring the actual adjustment opening of the electronic expansion valve in the uniform distribution mode; comparing the actual adjustment opening with a preset maximum adjustment opening; when the actual adjustment opening exceeds the preset maximum adjustment opening, controlling the electronic expansion valve to reset to the opening before the uniform distribution mode adjustment; reacquiring the pressure difference between the outdoor heat exchanger and the other outdoor heat exchangers; comparing the reacquiring pressure difference with the preset pressure difference; and adjusting the opening of the distribution valve based on the comparison result between the reacquiring pressure difference and the preset pressure difference. Through the above settings, when the electronic expansion valve cannot meet the requirements of uniform refrigerant distribution adjustment, the distribution valve can be used to quickly achieve refrigerant adjustment, improving control efficiency.

[0011] In the preferred technical solution for the air conditioner described above, the preset maximum adjustment opening is 90-110 steps; and / or the preset pressure difference ranges from 0.4 to 0.6 bar.

[0012] In the preferred technical solution for the air conditioner described above, the steps of the high-efficiency heat exchange mode include: acquiring the surface temperature difference between the outdoor heat exchanger and other outdoor heat exchangers; comparing the surface temperature difference with a preset surface temperature difference; and adjusting the opening degree of the corresponding electronic expansion valve based on the comparison result between the surface temperature difference and the preset surface temperature difference. In the high-efficiency heat exchange mode, adjusting the opening degree of the electronic expansion valve based on the surface temperature difference between the outdoor heat exchanger and other outdoor heat exchangers can make the refrigerant temperature (rather than the refrigerant quantity) in each outdoor heat exchanger tend to be consistent, thereby improving heat exchange efficiency.

[0013] In the preferred embodiment of the air conditioner described above, the air conditioner further includes a distribution valve for adjusting the proportion of refrigerant flowing into the plurality of outdoor heat exchangers, and the control method further includes: acquiring the actual adjustment opening of the electronic expansion valve in the high-efficiency heat exchange mode; comparing the actual adjustment opening with a preset maximum adjustment opening; when the actual adjustment opening exceeds the preset maximum adjustment opening, controlling the electronic expansion valve to reset to the opening before adjustment in the high-efficiency heat exchange mode; reacquiring the surface temperature difference between the outdoor heat exchanger and the other outdoor heat exchangers; comparing the reacquiring surface temperature difference with the preset surface temperature difference; and adjusting the opening of the distribution valve based on the comparison result between the reacquiring surface temperature difference and the preset surface temperature difference. Through the above settings, when the electronic expansion valve cannot meet the refrigerant distribution adjustment requirements, the distribution valve can be used to quickly achieve refrigerant adjustment, improving control efficiency.

[0014] In the preferred technical solution for the air conditioner described above, the preset maximum adjustment opening is 90-110 steps; and / or the preset surface temperature difference ranges from 1℃ to 3℃.

[0015] To address or improve to some extent the technical problem that the refrigerant regulation of the outdoor heat exchanger in an existing air conditioner cannot meet the needs of actual operating conditions, this invention provides a storage medium. The storage medium is suitable for storing multiple lines of program code, and the program code is suitable for being loaded and run by a processor to perform the control method for an air conditioner described above.

[0016] To address or improve to some extent the technical problem that the refrigerant regulation of the outdoor heat exchanger in existing air conditioners cannot meet the needs of actual operating conditions, this invention provides an air conditioner. The air conditioner includes the storage medium described above, or executes the control method for an air conditioner according to any of the above descriptions. This invention enables the opening control of the electronic expansion valve to better match actual operating conditions, improves the heat exchange efficiency of the outdoor heat exchanger, and increases the operating efficiency of the air conditioner. Attached Figure Description

[0017] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0018] Figure 1 This is a system schematic diagram of an embodiment of the air conditioner of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of an embodiment of the outdoor unit of the air conditioner of the present invention;

[0020] Figure 3 This is a flowchart illustrating the control method of the present invention for an air conditioner;

[0021] Figure 4 This is a flowchart illustrating the first embodiment of the control method for an air conditioner according to the present invention;

[0022] Figure 5 This is a schematic flowchart of the first part of the second embodiment of the control method for an air conditioner of the present invention;

[0023] Figure 6 This is a schematic flowchart of the second part of the second embodiment of the control method for an air conditioner of the present invention.

[0024] List of reference numerals in the attached diagram:

[0025] 1. Air conditioner; 10. Compressor; 20. Distribution valve; 31a. First outdoor heat exchanger; 31b. Second outdoor heat exchanger; 32a. First pressure sensor; 32b. Second pressure sensor; 33a. First electronic expansion valve; 33b. Second electronic expansion valve; 34a. First outdoor fan; 34b. Second outdoor fan; 40. Indoor heat exchanger; 50. Gas-liquid separator; 60. Electrical control box; 70a. First temperature sensor; 70b. Second temperature sensor; 70c. Third temperature sensor; 70d. Fourth temperature sensor; 70e. Fifth temperature sensor; 70f. Sixth temperature sensor. Detailed Implementation

[0026] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0027] It should be noted that in the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "installation," "setting," and "connection" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] To address or improve to some extent the technical problem that the refrigerant regulation of outdoor heat exchangers in existing air conditioners cannot meet the needs of actual operating conditions, this invention provides a control method for an air conditioner 1. The air conditioner 1 has multiple outdoor heat exchangers connected in parallel, and the control method includes: acquiring the inlet air temperature and outlet air temperature corresponding to each outdoor heat exchanger, and determining the inlet air temperature difference and outlet air temperature difference between every two outdoor heat exchangers (step S1); comparing each inlet air temperature difference with a preset inlet air temperature difference, and comparing each outlet air temperature difference with a preset outlet air temperature difference (step S2); and controlling the electronic expansion valve corresponding to each outdoor heat exchanger to adjust its opening degree according to a uniform distribution mode or a high-efficiency heat exchange mode based on the comparison results (step S3).

[0029] Figure 1 This is a system schematic diagram of an embodiment of the air conditioner of the present invention; Figure 2 This is a structural schematic diagram of an embodiment of the outdoor unit of the air conditioner of the present invention. (See attached diagram.) Figure 1 and Figure 2 As shown, in one or more embodiments, the air conditioner 1 of the present invention includes components such as a compressor 10, a distribution valve 20, two outdoor heat exchangers (i.e., a first outdoor heat exchanger 31a and a second outdoor heat exchanger 31b), two electronic expansion valves (i.e., a first electronic expansion valve 33a and a second electronic expansion valve 33b), an indoor heat exchanger 40, and a gas-liquid separator 50. The compressor 10, distribution valve 20, outdoor heat exchangers, electronic expansion valves, and gas-liquid separator 50 are arranged in the outdoor unit (e.g.,...). Figure 2 As shown in the figure, the indoor unit is arranged with components such as the indoor heat exchanger 40.

[0030] like Figure 2 As shown, the outdoor unit has a generally rectangular casing (not shown) to create space for accommodating components such as the outdoor heat exchanger. The casing can be made of suitable materials such as aluminum alloy or galvanized steel sheet, giving it good waterproof, corrosion-resistant, and weather-resistant properties to effectively protect the internal components from damage in outdoor environments. In one or more embodiments, a compressor 10 is located at the lower part of the casing. The compressor 10 is the core component of the air conditioner. The heavier compressor 10, positioned at the lower part of the casing, provides a stable structure for the entire outdoor unit and effectively reduces vibration and noise during compressor operation. The compressor 10 can be, but is not limited to, a screw compressor, a scroll compressor, or a centrifugal compressor.

[0031] See also Figure 1The discharge port of compressor 10 is connected to the inlet of distribution valve 20 via a refrigerant pipeline. In one or more embodiments, distribution valve 20 has two outlets, each connected to a corresponding outdoor heat exchanger, so that the ratio of refrigerant entering the first outdoor heat exchanger 31a and the second outdoor heat exchanger 31b can be adjusted by regulating the opening of distribution valve 20. Alternatively, distribution valve 20 may also have three, four, five, or other outlets, as long as they are compatible with the outdoor heat exchangers.

[0032] See also Figure 2 In one or more embodiments, the first outdoor heat exchanger 31a and the second outdoor heat exchanger 31b are arranged side-by-side in the vertical direction within the casing of the outdoor unit. Specifically, the first outdoor heat exchanger 31a is located at the upper part of the casing, while the second outdoor heat exchanger 31b is located at the lower part of the casing. The first outdoor heat exchanger 31a and the second outdoor heat exchanger 31b have the same shape and specifications, which facilitates installation and ensures that the first outdoor heat exchanger 31a and the second outdoor heat exchanger 31b have approximately the same heat exchange area, thereby improving the overall utilization efficiency of the heat exchangers. The first outdoor heat exchanger 31a and the second outdoor heat exchanger 31b can be finned coil heat exchangers, plate heat exchangers, or other suitable heat exchangers. Alternatively, the number of outdoor heat exchangers can also be set to three, four, five, or other suitable numbers according to actual needs.

[0033] See also Figure 2 In one or more embodiments, the first outdoor fan 34a and the second outdoor fan 34b are arranged side-by-side in the vertical direction within the casing of the outdoor unit. The first outdoor fan 34a is located at the upper part of the casing and corresponds to the first outdoor heat exchanger 31a; the second outdoor fan 34b is located at the lower part of the casing and corresponds to the second outdoor heat exchanger 31b. In one or more embodiments, the first outdoor fan 34a and the second outdoor fan 34b have the same shape and specifications, eliminating the need for strict wiring positions for each fan during installation, thus improving installation efficiency. The first outdoor fan 34a and the second outdoor fan 34b can be axial flow fans, cross flow fans, or other suitable fans. Alternatively, the number and arrangement of the outdoor fans can be adjusted according to actual needs.

[0034] See also Figure 1In one or more embodiments, a first pressure sensor 32a is further provided in the liquid distribution path of the first outdoor heat exchanger 31a to detect the refrigerant pressure in the liquid distribution circuit. Correspondingly, a second pressure sensor 32b is further provided in the liquid distribution path of the second outdoor heat exchanger 31b to detect the refrigerant pressure in the liquid distribution circuit. A first electronic expansion valve 33a is provided downstream of the first pressure sensor 32a to regulate the refrigerant flow rate in the liquid distribution path of the first outdoor heat exchanger 31a. Correspondingly, a second electronic expansion valve 33b is provided downstream of the second pressure sensor 32b to regulate the refrigerant flow rate in the liquid distribution path of the second outdoor heat exchanger 31b.

[0035] See also Figure 2 In one or more embodiments, a first temperature sensor 70a is provided on the casing of the outdoor unit, positioned near the first outdoor heat exchanger 31a, to detect the inlet air temperature of the first outdoor heat exchanger 31a. A fifth temperature sensor 70e is provided near the first outdoor fan 34a to detect the outlet air temperature of the first outdoor heat exchanger 31a. A third temperature sensor 70c is provided on the first outdoor heat exchanger 31a to detect the surface temperature of the first outdoor heat exchanger 31a. Correspondingly, a second temperature sensor 70b is provided on the casing of the outdoor unit, positioned near the second outdoor heat exchanger 31b, to detect the inlet air temperature of the second outdoor heat exchanger 31b. A sixth temperature sensor 70f is provided near the second outdoor fan 34b to detect the outlet air temperature of the second outdoor heat exchanger 31b. A fourth temperature sensor 70d is provided on the second outdoor heat exchanger 31b to detect the surface temperature of the second outdoor heat exchanger 31b. It should be noted that each temperature sensor can be a thermistor sensor, a thermocouple sensor, or other suitable temperature sensor. Furthermore, the number and arrangement of each temperature sensor can be adjusted according to actual needs.

[0036] See also Figure 2 In one or more embodiments, an electrical control box 60 is also provided on the upper part of the outdoor unit's casing. The electrical control box 60 contains electrical components such as a storage medium (not shown in the figure) and a controller (not shown in the figure). These electrical components are communicatively connected to components such as the first outdoor fan 34a, the second outdoor fan 34b, the compressor 10, and temperature sensors, so as to receive corresponding detection signals and send control signals to the corresponding components under a preset computer program, thereby controlling the smooth operation of the air conditioner 1.

[0037] See also Figure 1The refrigerant, expanded and depressurized by the electronic expansion valve, is connected to the indoor heat exchanger 40 of the indoor unit via refrigerant piping. The indoor heat exchanger 40 can be a finned coil heat exchanger, a plate heat exchanger, or other suitable heat exchanger. An indoor fan (not shown in the figure) is installed near the indoor heat exchanger 40 to improve its heat exchange efficiency. The indoor fan can be, but is not limited to, a cross-flow fan or an axial flow fan. Furthermore, the number of indoor units can be set to multiple, such as two, three, or four, depending on actual needs.

[0038] See also Figure 2 In one or more embodiments, a gas-liquid separator 50 is further provided between the indoor heat exchanger 40 and the air intake of the compressor 10. The gas-liquid separator 50 can effectively separate gaseous refrigerant and liquid refrigerant, preventing liquid refrigerant from entering the compressor 10 and causing liquid slugging, thereby ensuring the smooth operation of the compressor 10 and extending the service life of the compressor 10.

[0039] In one or more embodiments, the air conditioner 1 further includes a four-way valve (not shown) to adjust the flow direction of the refrigerant in the refrigeration circuit, thereby enabling the air conditioner 1 to have both cooling and heating functions.

[0040] Below, in conjunction with Figures 3-4 Detailed embodiments of the control method for an air conditioner 1 according to the present invention are provided below. It should be noted that the control method for an air conditioner according to the present invention can be implemented in the air conditioner 1 described in any of the above embodiments, or it can be used in other suitable air conditioners.

[0041] Figure 3 This is a flowchart illustrating the control method for an air conditioner according to the present invention. Figure 3 As shown, in one or more embodiments, when the control method of the present invention for air conditioner 1 starts, step S1 is first executed, that is, the inlet air temperature and outlet air temperature corresponding to each outdoor heat exchanger are obtained, and the inlet air temperature difference and outlet air temperature difference between every two outdoor heat exchangers are determined. Next, each inlet air temperature difference is compared with a preset inlet air temperature difference, and each outlet air temperature difference is compared with a preset outlet air temperature difference (step S2); then, step S3 is executed, that is, based on the comparison results, the electronic expansion valve corresponding to each outdoor heat exchanger is controlled to adjust its opening degree according to a uniform distribution mode or a high-efficiency heat exchange mode.

[0042] Figure 4 This is a flowchart illustrating the first embodiment of the control method for an air conditioner according to the present invention. Figure 4As shown, in one or more embodiments, after the control method of the present invention for air conditioner 1 starts, step S10 is first executed, that is, the inlet air temperature and outlet air temperature corresponding to each outdoor heat exchanger are obtained, and the inlet air temperature difference and outlet air temperature difference between every two outdoor heat exchangers are determined. The inlet air temperature and outlet air temperature corresponding to the outdoor heat exchanger can be measured by the corresponding temperature sensor. Next, the control method executes step S21, determining whether all inlet air temperature differences of an outdoor heat exchanger are less than or equal to a preset inlet air temperature difference. In one or more embodiments, the preset inlet air temperature difference ranges from 0.5℃ to 1.5℃ (i.e., degrees Celsius). When the determination result is yes, the control method continues to execute step S22, that is, determining whether all outlet air temperatures of the outdoor heat exchanger are less than or equal to the preset outlet air temperature difference. In one or more embodiments, the preset outlet air temperature difference ranges from 0.5℃ to 1.5℃. When the judgment result is also yes, it means that the difference between the inlet air temperature and outlet air temperature of the outdoor heat exchanger and other outdoor heat exchangers is small. Then, the electronic expansion valve corresponding to the outdoor heat exchanger is controlled to adjust the opening degree according to the uniform distribution mode (i.e., step S31).

[0043] See also Figure 4 In step S31, the control method first executes step S311, which involves acquiring the pressure difference between the outdoor heat exchanger and other outdoor heat exchangers. The pressure of the outdoor heat exchanger can be measured by a pressure sensor arranged in the corresponding liquid distribution path. Next, the control method executes step S312, which involves determining whether all pressure differences are less than or equal to a preset pressure difference. In one or more embodiments, the preset pressure difference is 0.4-0.6 bar. Then, the opening of the corresponding electronic expansion valve is adjusted based on the comparison result. Specifically, when the determination result is yes, it indicates that the pressure difference between the outdoor heat exchanger and other outdoor heat exchangers is small, and the corresponding electronic expansion valve is controlled to maintain the current step number (step S313). When the determination result is no, it indicates that the pressure difference between the outdoor heat exchanger and other outdoor heat exchangers is large. In one or more embodiments, when the air conditioner 1 is in heating mode, if the pressure difference of the outdoor heat exchanger exceeds the preset pressure difference, the corresponding electronic expansion valve is controlled to decrease by a predetermined number of steps (i.e., step S314). Alternatively, when the air conditioner 1 is in cooling mode, if the pressure difference of the outdoor heat exchanger exceeds a preset pressure difference, the corresponding electronic expansion valve is controlled to increase by a predetermined number of steps. In one or more embodiments, the predetermined number of steps can be 5 steps, 8 steps, 10 steps, or other suitable steps.

[0044] See also Figure 4In steps S21 and S22, if the judgment result is negative, the control method proceeds to step S32, which controls the corresponding electronic expansion valve to adjust its opening according to the high-efficiency heat exchange mode. It should be noted that when the inlet air temperature difference of the outdoor heat exchanger exceeds the preset inlet air temperature difference, it indicates a significant difference in the external environment temperature. When the outlet air temperature difference of the outdoor heat exchanger exceeds the preset outlet air temperature difference, it indicates a large difference in the heat exchange efficiency of the heat exchanger (e.g., influenced by wind speed). In this case, if the opening of the electronic expansion valve is controlled based on pressure, even if the amount of refrigerant flowing into each outdoor heat exchanger is the same, the different actual operating conditions of the outdoor heat exchangers will prevent them from achieving optimal heat exchange efficiency. Therefore, this invention, by controlling the opening of the corresponding electronic expansion valve to adjust its opening according to the high-efficiency heat exchange mode, can effectively improve the heat exchange efficiency of the outdoor heat exchanger to meet the actual needs of different operating conditions.

[0045] See also Figure 4 In step S32, step S321 is first executed, which involves acquiring the surface temperature difference between the outdoor heat exchanger and other outdoor heat exchangers. The surface temperature of the outdoor heat exchanger can be measured by a temperature sensor installed on the outdoor heat exchanger. Next, the control method executes step S322, which involves determining whether all surface temperature differences are less than or equal to a preset surface temperature difference. In one or more embodiments, the preset surface temperature is 1℃-2℃. Then, the opening of the corresponding electronic expansion valve is adjusted based on the comparison result. Specifically, when the determination result is yes, it indicates that the surface temperature difference between the outdoor heat exchanger and other outdoor heat exchangers is small, and the corresponding electronic expansion valve is controlled to maintain the current step number (step S323). When the determination result is no, it indicates that the surface temperature difference between the outdoor heat exchanger and other outdoor heat exchangers is large. In one or more embodiments, when the air conditioner 1 is in heating mode, if the surface temperature difference of the outdoor heat exchanger exceeds the preset surface temperature difference, the corresponding electronic expansion valve is controlled to decrease by a predetermined number of steps (i.e., step S324). Alternatively, when the air conditioner 1 is in cooling mode, if the surface temperature difference of the outdoor heat exchanger exceeds a preset surface temperature difference, the corresponding electronic expansion valve is controlled to increase by a predetermined number of steps. In one or more embodiments, the predetermined number of steps may be 5 steps, 8 steps, 10 steps, or other suitable steps.

[0046] Figure 5 This is a schematic flowchart of the first part of a second embodiment of the control method for an air conditioner according to the present invention. Figure 5As shown, in one or more embodiments, the air conditioner 1 has a distribution valve 20 for adjusting the proportion of refrigerant flowing into multiple outdoor heat exchangers, and the control method of the present invention further performs step S330, that is, obtaining the actual adjustment opening of the electronic expansion valve in the uniform distribution mode. Next, the control method performs step S331, that is, determining whether the actual adjustment opening exceeds the preset maximum opening. In one or more embodiments, the preset maximum opening is 90-110 steps. When the determination result is no, it means that the refrigerant quantity can still be effectively adjusted by adjusting the opening of the electronic expansion valve, and the opening of the electronic expansion valve continues to be adjusted based on the corresponding control program. When the determination result is yes, it means that the refrigerant quantity cannot be efficiently adjusted by the electronic expansion valve, and the electronic expansion valve is controlled to reset to the opening before the uniform distribution mode adjustment (i.e., step S322). Next, the pressure difference between the outdoor heat exchanger and other outdoor heat exchangers is obtained again (i.e., step S333). After step S333 is completed, the control method proceeds to step S334, that is, determining whether the remeasured pressure difference is less than or equal to the preset pressure difference. If the judgment result is yes, then the corresponding electronic expansion valve is controlled to maintain the current step number (i.e., step S335). If the judgment result is no, if the air conditioner 1 is in heating mode, then the distribution valve 20 is controlled to decrease the preset opening degree (i.e., step S336) to appropriately reduce the amount of refrigerant flowing into the outdoor heat exchanger; if the air conditioner 1 is in cooling mode, then the distribution valve 20 is controlled to increase the preset opening degree to appropriately increase the amount of refrigerant flowing into the outdoor heat exchanger. The preset opening degree can be flexibly adjusted according to the specifications of the distribution valve 20 and actual needs.

[0047] Figure 6 This is a schematic flowchart of the second part of a second embodiment of the control method for an air conditioner according to the present invention. Figure 6As shown, in one or more embodiments, the air conditioner 1 has a distribution valve 20 for adjusting the proportion of refrigerant flowing into multiple outdoor heat exchangers, and the control method of the present invention further performs step S340, that is, obtaining the actual adjustment opening of the electronic expansion valve in the high-efficiency heat exchange mode. Next, the control method performs step S341, that is, determining whether the actual adjustment opening exceeds the preset maximum opening. In one or more embodiments, the preset maximum opening is 90-110 steps. When the determination result is negative, it means that the refrigerant quantity can still be effectively adjusted by adjusting the opening of the electronic expansion valve, and the opening of the electronic expansion valve continues to be adjusted based on the corresponding control program. When the determination result is positive, it means that the refrigerant quantity cannot be efficiently adjusted by the electronic expansion valve, and the electronic expansion valve is controlled to reset to the opening before adjustment in the high-efficiency heat exchange mode (i.e., step S342). Next, the surface temperature difference between the outdoor heat exchanger and other outdoor heat exchangers is obtained again (i.e., step S343). After step S343 is completed, the control method proceeds to step S344, that is, determining whether the remeasured surface temperature difference is less than or equal to the preset surface temperature difference. If the judgment result is yes, then the corresponding electronic expansion valve is controlled to maintain the current step number (i.e., step S345). If the judgment result is no, if the air conditioner 1 is in heating mode, then the distribution valve 20 is controlled to reduce the preset opening degree (i.e., step S346) to appropriately reduce the amount of refrigerant flowing into the outdoor heat exchanger; if the air conditioner 1 is in cooling mode, then the distribution valve 20 is controlled to increase the preset opening degree to appropriately increase the amount of refrigerant flowing into the outdoor heat exchanger.

[0048] It should be noted that the parts not mentioned in the second embodiment can be configured the same as in the first embodiment, and will not be repeated here.

[0049] To address or improve to some extent the technical problem that the refrigerant regulation of the outdoor heat exchanger in an air conditioner cannot meet the needs of actual operating conditions, this invention provides a storage medium (not shown in the figure). This storage medium is suitable for storing multiple lines of program code, and the program code is suitable for being loaded and run by a processor to execute the control method for an air conditioner described in any of the above embodiments.

[0050] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A control method for an air conditioner, characterized in that, The air conditioner has multiple outdoor heat exchangers connected in parallel, and the control method includes: Obtain the inlet air temperature and outlet air temperature corresponding to each of the outdoor heat exchangers, and determine the inlet air temperature difference and outlet air temperature difference between every two outdoor heat exchangers. Each of the aforementioned inlet air temperature differences is compared with a preset inlet air temperature difference, and each of the aforementioned outlet air temperature differences is compared with a preset outlet air temperature difference. Based on the comparison results, the electronic expansion valve corresponding to each outdoor heat exchanger is controlled to adjust its opening degree according to either a uniform distribution mode or a high-efficiency heat exchange mode. Specifically, when all the inlet air temperature differences of an outdoor heat exchanger are less than or equal to the preset inlet air temperature difference and all the corresponding outlet air temperature differences are less than or equal to the preset outlet air temperature difference, the corresponding electronic expansion valve is controlled to adjust its opening according to the uniform distribution mode; otherwise, the corresponding electronic expansion valve is controlled to adjust its opening according to the high-efficiency heat exchange mode.

2. The control method for an air conditioner according to claim 1, characterized in that, The steps of the uniform distribution pattern include: Obtain the pressure difference between the outdoor heat exchanger and the other outdoor heat exchangers; Compare the pressure difference with a preset pressure difference; The opening degree of the corresponding electronic expansion valve is adjusted based on the comparison result between the pressure difference and the preset pressure difference.

3. The control method for an air conditioner according to claim 2, characterized in that, The air conditioner also includes a distribution valve for adjusting the proportion of refrigerant flowing into the plurality of outdoor heat exchangers, and the control method further includes: Obtain the actual adjustment opening of the electronic expansion valve under the uniform distribution mode; The actual adjustment opening is compared with the preset maximum adjustment opening; When the actual adjustment opening exceeds the preset maximum adjustment opening, the electronic expansion valve is controlled to reset to the opening before the uniform distribution mode adjustment; Reacquire the pressure difference between the outdoor heat exchanger and the other outdoor heat exchangers; The reacquired pressure difference is compared with the preset pressure difference; The opening of the distribution valve is adjusted based on the comparison between the reacquired pressure difference and the preset pressure difference.

4. The control method for an air conditioner according to claim 3, characterized in that, The preset maximum adjustment opening is 90-110 steps; and / or The preset pressure difference ranges from 0.4 to 0.6 bar.

5. The control method for an air conditioner according to claim 1, characterized in that, The steps of the high-efficiency heat exchange mode include: The surface temperature difference between the outdoor heat exchanger and the other outdoor heat exchangers is obtained. The surface temperature difference is compared with a preset surface temperature difference; The opening degree of the corresponding electronic expansion valve is adjusted based on the comparison result between the surface temperature difference and the preset surface temperature difference.

6. The control method for an air conditioner according to claim 5, characterized in that, The air conditioner also includes a distribution valve for adjusting the proportion of refrigerant flowing into the plurality of outdoor heat exchangers, and the control method further includes: Obtain the actual adjustment opening of the electronic expansion valve under the high-efficiency heat exchange mode; The actual adjustment opening is compared with the preset maximum adjustment opening; When the actual adjustment opening exceeds the preset maximum adjustment opening, the electronic expansion valve is controlled to reset to the opening before the high-efficiency heat exchange mode adjustment; Reacquire the surface temperature difference between the outdoor heat exchanger and the other outdoor heat exchangers; The reacquired surface temperature difference is compared with the preset surface temperature difference; The opening degree of the distribution valve is adjusted based on the comparison between the reacquired surface temperature difference and the preset surface temperature difference.

7. The control method for an air conditioner according to claim 6, characterized in that, The preset maximum adjustment opening is 90-110 steps; and / or The preset surface temperature difference ranges from 1℃ to 3℃.

8. A storage medium, characterized in that, The storage medium is adapted to store a plurality of program codes, and the program codes are adapted to be loaded and run by a processor to perform the control method for an air conditioner according to any one of claims 1-7.

9. An air conditioner, characterized in that, The air conditioner includes the storage medium according to claim 8, or the air conditioner performs the control method for an air conditioner according to any one of claims 1-7.

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