A low-pressure saturation temperature acquisition method, a compressor operating frequency control method, an outdoor fan rotating speed control method and an air conditioner

Abstract

The application provides a low-pressure saturated temperature acquisition method, a compressor operating frequency control method, an outdoor fan rotating speed control method and an air conditioner, and relates to the technical field of air conditioners. The low-pressure saturated temperature acquisition method comprises the following steps: acquiring corresponding operating parameters according to the operating mode of the air conditioner; determining a pressure loss compensation coefficient according to the operating mode of the air conditioner and the operating frequency of the compressor; and calculating the difference between the operating parameters and the pressure loss compensation coefficient to obtain the low-pressure saturated temperature. The low-pressure saturated temperature acquisition method provided by the application can obtain the low-pressure saturated temperature without relying on a low-pressure sensor, provides a control basis for the low-pressure control of the air conditioner, and improves the performance of the air conditioner.

Description

TECHNICAL FIELD

[0001] The present application relates to the air conditioning technical field, and in particular, relates to a low-pressure saturation temperature acquisition method, a compressor operating frequency control method, an external fan rotating speed control method and an air conditioner. BACKGROUND

[0002] In order to reduce production cost, the multi-split air conditioner on the market generally cancels the configuration of a low-pressure sensor, which results in lack of low-pressure control basis for accurately controlling the operating frequency of the compressor, the rotating speed of the external fan and the like of the air conditioner, and influences the air conditioner performance. SUMMARY

[0003] The present application solves the problem that the multi-split air conditioner lacks low-pressure control basis due to the cancellation of the configuration of a low-pressure sensor, which results in that the low-pressure temperature and the low-pressure pressure cannot be accurately controlled, and influences the air conditioner performance.

[0004] To solve the above problem, the present application provides a low-pressure saturation temperature acquisition method, which can obtain the low-pressure saturation temperature without relying on a low-pressure sensor, provides a control basis for the low-pressure control of the air conditioner, and improves the air conditioner performance.

[0005] Embodiments of the present application provide a technical solution:

[0006] A low-pressure saturation temperature acquisition method comprises:

[0007] obtaining corresponding operating parameters according to the operating mode of the air conditioner;

[0008] determining a pressure loss compensation coefficient according to the operating mode of the air conditioner and the operating frequency of the compressor;

[0009] calculating the difference between the operating parameters and the pressure loss compensation coefficient to obtain the low-pressure saturation temperature.

[0010] The low-pressure saturation temperature acquisition method provided by the embodiments of the present application obtains corresponding operating parameters according to the operating mode of the air conditioner, determines a pressure loss compensation coefficient in combination with the operating frequency of the compressor, and finally obtains the low-pressure saturation temperature by calculating the difference between the operating parameters and the pressure loss compensation coefficient, which serves as the basis for the low-pressure control of the air conditioner, ensures the accurate control of the low-pressure temperature and the low-pressure pressure, and improves the air conditioner performance.

[0011] Further, the operating parameters include a lowest inlet temperature, and the step of obtaining corresponding operating parameters according to the operating mode of the air conditioner comprises:

[0012] if the air conditioner operates in a cooling mode or a dehumidification mode, obtaining the inlet temperatures of all operating indoor units;

[0013] comparing the obtained plurality of inlet temperatures to obtain the lowest inlet temperature.

[0014] Further, the operation parameter comprises an outdoor coil temperature, and the step of obtaining the corresponding operation parameter according to the operation mode of the air conditioner comprises:

[0015] If the air conditioner operates in the heating mode, the coil temperature of the outdoor heat exchanger is obtained to obtain the outdoor coil temperature.

[0016] Further, the air conditioner pre-stores a first corresponding relationship between the frequency range of the compressor and the pressure loss compensation coefficient, and the step of determining the pressure loss compensation coefficient according to the operation mode of the air conditioner and the operation frequency of the compressor comprises:

[0017] If the air conditioner operates in the cooling mode or the dehumidification mode, the pressure loss compensation coefficient corresponding to the frequency range in which the operation frequency of the compressor is located is determined according to the first corresponding relationship.

[0018] Further, the air conditioner pre-stores a second corresponding relationship between the frequency range of the compressor and the pressure loss compensation coefficient, and the step of determining the pressure loss compensation coefficient according to the operation mode of the air conditioner and the operation frequency of the compressor comprises:

[0019] If the air conditioner operates in the heating mode, the pressure loss compensation coefficient corresponding to the frequency range in which the operation frequency of the compressor is located is determined according to the second corresponding relationship.

[0020] The embodiment of the present application also provides a compressor operation frequency control method, comprising:

[0021] Periodically obtaining the low-pressure saturation temperature and the average inlet temperature of the air conditioner, wherein the low-pressure saturation temperature is obtained according to the low-pressure saturation temperature obtaining method;

[0022] Determining the frequency change amount according to the obtained low-pressure saturation temperature and average inlet temperature;

[0023] Adjusting the operation frequency of the compressor according to the frequency change amount.

[0024] Further, the step of periodically obtaining the low-pressure saturation temperature and the average inlet temperature of the air conditioner comprises:

[0025] Periodically obtaining the inlet temperatures of all operating indoor units;

[0026] Calculating the average value of the obtained plurality of inlet temperatures to obtain the average inlet temperature.

[0027] Further, in the first time length after the air conditioner is turned on, or in the second time length after the total capacity of the operating indoor unit changes, a third time length is taken as a control period, otherwise, a fourth time length is taken as a control period.

[0028] Further, the step of determining the frequency variation according to the obtained low-pressure saturation temperature and the average inlet temperature comprises:

[0029] calculating a difference between the average inlet temperature and the low-pressure saturation temperature to obtain a temperature loss value;

[0030] calculating a difference between the current temperature loss value and the temperature loss value obtained in the previous period to obtain a temperature loss difference value;

[0031] determining a first correction coefficient and a second correction coefficient according to the frequency variation determined in the previous period;

[0032] calculating a product of the temperature loss difference value and the first correction coefficient and a sum of a product of the current temperature loss value and the second correction coefficient to obtain the current frequency variation.

[0033] Further, the step of determining the first correction coefficient and the second correction coefficient according to the frequency variation determined in the previous period comprises:

[0034] if a ratio of the total capacity of the indoor units in all refrigeration operations to the capacity of the outdoor unit is less than or equal to a first ratio value, determining the first correction coefficient and the second correction coefficient according to a range of the frequency variation determined in the previous period;

[0035] if the ratio of the total capacity of the indoor units in all refrigeration operations to the capacity of the outdoor unit is greater than the first ratio value, determining the first correction coefficient and the second correction coefficient according to a relationship between the low-pressure saturation temperature and the average inlet temperature and a range of the frequency variation determined in the previous period.

[0036] Embodiments of the present application also provide an outdoor fan speed control method, comprising:

[0037] obtaining a low-pressure saturation temperature of an air conditioner, wherein the low-pressure saturation temperature is obtained according to the low-pressure saturation temperature obtaining method described above;

[0038] determining a low-pressure pressure according to the low-pressure saturation temperature;

[0039] adjusting a speed of an outdoor fan of the air conditioner according to the low-pressure pressure.

[0040] Further, the step of adjusting the speed of the outdoor fan of the air conditioner according to the low-pressure pressure comprises:

[0041] if the low-pressure pressure is less than a first preset pressure value, maintaining the current speed of the outdoor fan for a preset time length and then increasing the speed by one level;

[0042] If the low pressure is greater than or equal to the first preset pressure value and less than or equal to a second preset pressure value, the current speed of the external fan is maintained;

[0043] If the low pressure is greater than the second preset pressure value, the speed of the external fan is reduced by one level after the preset time period.

[0044] Further, the external fan speed control method further comprises:

[0045] obtaining a high pressure of the air conditioner;

[0046] The step of adjusting the speed of the external fan of the air conditioner according to the low pressure further comprises:

[0047] adjusting the speed of the external fan of the air conditioner according to the low pressure and the high pressure.

[0048] Further, the step of adjusting the speed of the external fan of the air conditioner according to the low pressure and the high pressure comprises:

[0049] If the low pressure is less than or equal to a third preset pressure value and the high pressure is less than or equal to a fourth preset pressure value, the speed of the external fan is adjusted to the maximum level;

[0050] If the high pressure is greater than or equal to a sixth preset pressure value, the increase of the speed of the external fan is limited, and the limitation is released when the high pressure decreases to be less than or equal to a fifth preset pressure value;

[0051] If the high pressure is greater than or equal to a seventh preset pressure value, the speed of the external fan is adjusted to the minimum level and locked, and the lock is released when the high pressure decreases to be less than or equal to the fifth preset pressure value;

[0052] The fourth preset pressure value, the fifth preset pressure value, the sixth preset pressure value and the seventh preset pressure value increase in turn.

[0053] Embodiments of the present application also provide an air conditioner comprising a controller configured to execute the low pressure saturation temperature acquisition method, the compressor operating frequency control method or the external fan speed control method. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 a partial structure block diagram of the air conditioner provided by embodiments of the present application;

[0055] Figure 2 a flow chart of the low pressure saturation temperature acquisition method provided by embodiments of the present application;

[0056] Figure 3 A flow chart of a sub-step in step S101; Figure 2 A flow chart of a sub-step in step S102;

[0057] Figure 4 A flow chart of a sub-step in step S102; Figure 2 A flow chart of a sub-step in step S102;

[0058] Figure 5 A flow chart of a sub-step in step S202;

[0059] Figure 6 A flow chart of a sub-step in step S202; Figure 5 A flow chart of a sub-step in step S201;

[0060] Figure 7 A flow chart of a sub-step in step S202; Figure 5 A flow chart of a sub-step in step S202;

[0061] Figure 8 A flow chart of a sub-step in step S303;

[0062] Figure 9 A flow chart of a sub-step in step S303; Figure 8 A flow chart of a sub-step in step S303;

[0063] Figure 10 A flow chart of a sub-step in step S303; Figure 8 A flow chart of a sub-step in step S303;

[0064] Figure 11 A flow chart of a sub-step in step S303; Figure 10 A flow chart of a sub-step in step S303;

[0065] BRIEF DESCRIPTION OF DRAWINGS

[0066] 100-air conditioner; 110-controller; 120-compressor; 130-outer fan; 140-inlet sensor; 150-defrosting sensor. DETAILED DESCRIPTION

[0067] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0068] Please refer to Figure 1 , Figure 1 Fig. 1 shows a partial structure block diagram of an air conditioner 100 provided by the present embodiment.

[0069] The air conditioner 100 provided by the embodiment is a multi-split air conditioner, comprising a controller 110, a compressor 120, an outdoor fan 130, an inlet sensor 140 arranged at the inlet of each indoor unit, and a defrosting sensor 150 arranged on the outdoor coil, and the controller 110 is electrically connected with the compressor 120, the outdoor fan 130, the defrosting sensor 150 and the plurality of inlet sensors 140 respectively.

[0070] It can be understood that the defrosting sensor 150 and the inlet sensor 140 are the existing configurations of the multi-split air conditioner, which are directly used in the embodiment and will not cause an increase in production cost due to special configurations.

[0071] The controller 110 is configured to obtain corresponding operating parameters according to the operating mode of the air conditioner 100, and to determine a pressure loss compensation coefficient according to the operating mode and the operating frequency of the compressor 120, and to calculate the difference between the operating parameters and the pressure loss compensation coefficient to obtain the low-pressure saturation temperature.

[0072] The controller 110 controls the operating frequency of the compressor 120 and the rotating speed of the outdoor fan 130 according to the obtained low-pressure saturation temperature, so as to accurately control the low-pressure temperature and the low-pressure pressure of the air conditioner 100 and improve the air conditioning performance.

[0073] In actual application, the plurality of inlet sensors 140 are configured to detect the inlet temperature of the indoor unit corresponding thereto, and in the cooling mode or the dehumidifying mode, the controller 110 compares the inlet temperatures of the plurality of indoor units in operation received thereby to obtain the lowest inlet temperature as the operating parameter for calculating the low-pressure saturation temperature.

[0074] The defrosting sensor 150 is configured to detect the coil temperature of the outdoor heat exchanger, and in the heating mode, the controller 110 takes the received outdoor coil temperature as the operating parameter for calculating the low-pressure saturation temperature.

[0075] In fact, the controller 110 of the air conditioner 100 provided by the embodiment is configured to execute the low-pressure saturation temperature obtaining method to obtain the low-pressure saturation temperature. Please refer to the low-pressure saturation temperature obtaining method provided by the embodiment shown in Figure 2 , Figure 2 The flow chart shown in FIG. 10 is a flow chart of the low-pressure saturation temperature obtaining method provided by the embodiment, which can comprise the following steps:

[0076] In step S101, corresponding operating parameters are obtained according to the operating mode of the air conditioner 100.

[0077] Please refer to the low-pressure saturation temperature obtaining method provided by the embodiment shown in Figure 3 , Figure 3 The flow chart shown in FIG. 10 is a flow chart of the low-pressure saturation temperature obtaining method provided by the embodiment, which can comprise the following steps:

[0078] Sub-step S1011, if the air conditioner 100 is running in the cooling mode or the dehumidification mode, the inlet temperature of all running indoor units is obtained.

[0079] Sub-step S1012, the obtained multiple inlet temperatures are compared to obtain the lowest inlet temperature.

[0080] Sub-step S1013, if the air conditioner 100 is running in the heating mode, the coil temperature of the outdoor heat exchanger is obtained to obtain the outer coil temperature.

[0081] It can be understood that when the air conditioner 100 is running in the cooling mode or the dehumidification mode, the controller 110 takes the lowest inlet temperature as the operating parameter for calculating the low-pressure saturation temperature. When the air conditioner 100 is running in the heating mode, the controller 110 takes the received outer coil temperature as the operating parameter for calculating the low-pressure saturation temperature.

[0082] Please continue to refer to Figure 2 The low-pressure saturation temperature acquisition method provided in the embodiment can further include:

[0083] Further, step S102, the pressure loss compensation coefficient is determined according to the running mode of the air conditioner 100 and the running frequency of the compressor 120.

[0084] In fact, the air conditioner 100 pre-stores the first correspondence relationship and the second correspondence relationship between the frequency range of the compressor 120 and the pressure loss compensation coefficient. Please refer to Figure 4 , Figure 4 The sub-step flow chart of step S102 is shown in the figure, and step S102 can include the following sub-steps:

[0085] Sub-step S1021, if the air conditioner 100 is running in the cooling mode or the dehumidification mode, the pressure loss compensation coefficient corresponding to the frequency range in which the running frequency of the compressor 120 is located is determined according to the first correspondence relationship.

[0086] Specifically, the first correspondence relationship is shown in the following table:

[0087] Frequency range Pressure loss compensation factor UF≤ 30 Hz 4 30 Hz < UF < 35 Hz First maintenance value 35 Hz≤ UF≤ 50 Hz 6 50 Hz < UF < 55 Hz Second maintenance value 55 Hz≤ UF≤ 70 Hz 8 70 Hz < UF < 75 Hz Third maintenance value UF≥ 75 Hz 10

[0088] UF in the table refers to the running frequency of the compressor 120. For example, if the air conditioner 100 is running in the cooling mode or the dehumidification mode, and the running frequency of the compressor 120 is less than or equal to 30Hz, the pressure loss compensation coefficient is 4.

[0089] The specific values of the first, second and third maintenance values are determined by the rising and falling actions of the operating frequency of the compressor 120. If the operating frequency of the compressor 120 rises to reach the frequency range corresponding to the first, second or third maintenance value, the corresponding maintenance value is the value corresponding to the frequency range before the rising action, for example, if the operating frequency of the compressor 120 rises to reach between 30 Hz and 35 Hz, the first maintenance value takes the value corresponding to the frequency range of less than or equal to 30 Hz, i.e. 4.

[0090] If the operating frequency of the compressor 120 falls to reach the frequency range corresponding to the first, second or third maintenance value, the corresponding maintenance value is the value corresponding to the frequency range before the falling action, for example, if the operating frequency of the compressor 120 falls to reach between 30 Hz and 35 Hz, the first maintenance value takes the value corresponding to the frequency range of between 35 Hz and 50 Hz, i.e. 6.

[0091] In sub-step S1022, if the air conditioner 100 operates in the heating mode, the pressure loss compensation coefficient corresponding to the frequency range in which the operating frequency of the compressor 120 is located is determined according to the second corresponding relationship.

[0092] Specifically, the second corresponding relationship is as shown in the following table:

[0093] Frequency range Pressure loss compensation factor UF≤ 35 Hz 3 35 Hz < UF < 40 Hz Fourth maintenance value 40 Hz≤ UF≤ 60 Hz 4 60 Hz < UF < 65 Hz Fifth maintenance value 65 Hz≤ UF≤ 85 Hz 5 85 Hz < UF < 90 Hz Sixth maintenance value UF≥ 90 Hz 7

[0094] Similarly, UF in the table refers to the operating frequency of the compressor 120, for example, if the air conditioner 100 operates in the heating mode and the operating frequency of the compressor 120 is less than or equal to 35 Hz, the pressure loss compensation coefficient takes 3.

[0095] Similarly, the specific values of the fourth, fifth and sixth maintenance values are determined by the rising and falling actions of the operating frequency of the compressor 120. If the operating frequency of the compressor 120 rises to reach the frequency range corresponding to the fourth, fifth or sixth maintenance value, the corresponding maintenance value is the value corresponding to the frequency range before the rising action, for example, if the operating frequency of the compressor 120 rises to reach between 35 Hz and 40 Hz, the fourth maintenance value takes the value corresponding to the frequency range of less than or equal to 35 Hz, i.e. 3.

[0096] If the operating frequency of the compressor 120 falls to reach the frequency range corresponding to the fourth, fifth or sixth maintenance value, the corresponding maintenance value is the value corresponding to the frequency range before the falling action, for example, if the operating frequency of the compressor 120 falls to reach between 35 Hz and 40 Hz, the fourth maintenance value takes the value corresponding to the frequency range of between 40 Hz and 60 Hz, i.e. 4.

[0097] Further, please continue to refer to Figure 2The low-pressure saturation temperature acquisition method provided in this embodiment can further include the following steps.

[0098] In step S103, the difference between the operating parameter and the pressure loss compensation coefficient is calculated to obtain the low-pressure saturation temperature.

[0099] It can be understood that in the refrigeration mode or the dehumidification mode, the low-pressure saturation temperature is obtained by subtracting the pressure loss compensation coefficient from the minimum inlet temperature; and in the heating mode, the low-pressure saturation temperature is obtained by subtracting the pressure loss compensation coefficient from the outdoor coil temperature.

[0100] The controller 110 executes the low-pressure saturation temperature acquisition method provided in this embodiment, and can obtain the low-pressure saturation temperature according to the existing sensors without relying on the low-pressure sensor, so as to improve the air conditioning performance as the low-pressure control basis of the air conditioner 100.

[0101] The controller 110 of the air conditioner 100 provided in this embodiment is further configured to execute the compressor 120 operating frequency control method, which will be described in combination with the flow block diagram of the compressor 120 operating frequency control method shown in FIG. 13. Figure 5 Figure 5 The compressor 120 operating frequency control method provided in this embodiment can include the following steps.

[0102] In step S201, the low-pressure saturation temperature and the average inlet temperature of the air conditioner 100 are periodically obtained.

[0103] The low-pressure saturation temperature is obtained according to the low-pressure saturation temperature acquisition method described above.

[0104] The average inlet temperature can be obtained according to the method shown in FIG. 11. Figure 6 Figure 6 The step S201 can include the following sub-steps, as shown in the flow block diagram of one sub-step of the step S201 in FIG. 12.

[0105] In sub-step S2011, the inlet temperatures of all the running indoor units are periodically obtained.

[0106] In sub-step S2012, the average value of the obtained multiple inlet temperatures is calculated to obtain the average inlet temperature.

[0107] It can be understood that every time a period elapses, the multiple inlet temperature sensors feed back the corresponding inlet temperatures detected by the sensors to the controller 110, and the controller 110 calculates the average value of the multiple inlet temperatures to obtain an average inlet temperature corresponding to the current period.

[0108] For the specific duration of the period, in this embodiment, a third duration is taken as the control period within the first duration after the air conditioner 100 is started or within the second duration after the total capacity of the running indoor units changes, otherwise, a fourth duration is taken as the control period. ​​

[0109] Specifically, the first time length and the second time length are both 4 minutes, the third time length is 15 seconds, and the fourth time length is 60 seconds. In other words, the compressor 120 running frequency control method is executed every 15 seconds within 4 minutes after the air conditioner 100 is started or within 4 minutes when the total capacity of the indoor unit in operation changes. In addition to the 4 minutes after the air conditioner 100 is started and the 4 minutes when the total capacity of the indoor unit in operation changes, the compressor 120 running frequency control method is executed every 60 seconds in other time periods.

[0110] Further, please continue to refer to Figure 5 The compressor 120 running frequency control method can further include:

[0111] Step S202, determining the frequency change amount according to the obtained low-pressure saturation temperature and average inlet temperature.

[0112] Please refer to Figure 7 , Figure 7 As shown in FIG. 2, step S202 can include the following sub-steps:

[0113] Sub-step S2021, calculating the difference between the average inlet temperature and the low-pressure saturation temperature to obtain a temperature loss value.

[0114] In each cycle, the difference between the average inlet temperature and the low-pressure saturation temperature is calculated to obtain a temperature loss value.

[0115] Sub-step S2022, calculating the difference between the current temperature loss value and the temperature loss value obtained in the previous cycle to obtain a temperature loss difference value.

[0116] Subtracting the temperature loss value obtained in the previous cycle from the current temperature loss value to obtain the temperature loss difference value.

[0117] Sub-step S2023, determining the first correction coefficient and the second correction coefficient according to the frequency change amount determined in the previous cycle.

[0118] For the determination of the first correction coefficient and the second correction coefficient, if the ratio of the total capacity of all indoor units in refrigeration operation to the capacity of the outdoor unit is less than or equal to the first ratio, the first correction coefficient and the second correction coefficient are determined according to the range of the frequency change amount determined in the previous cycle.

[0119] If the ratio of the total capacity of all indoor units in refrigeration operation to the capacity of the outdoor unit is greater than the first ratio, the first correction coefficient and the second correction coefficient are determined according to the size relationship between the low-pressure saturation temperature and the average inlet temperature, and the range of the frequency change amount determined in the previous cycle.

[0120] In fact, for the specific values of the first correction coefficient and the second correction coefficient, please refer to the following table:

[0121]

[0122] The Kp in the above table is the first correction coefficient, the Ki is the second correction coefficient, the ΔUF is the frequency change amount, the Te2_ave is the average inlet temperature, and the Tso is the low-pressure saturation temperature. It can be seen that the first ratio is 20%. In the case where the determination condition corresponding to the high priority is satisfied, the determination mode of the first correction coefficient and the second correction coefficient corresponding to the high priority is determined; in the case where the determination condition corresponding to the high priority is not satisfied, the determination mode of the first correction coefficient and the second correction coefficient corresponding to the low priority is determined.

[0123] In sub-step S2024, the product of the temperature loss difference value and the first correction coefficient is calculated, and the sum of the product of the current temperature loss value and the second correction coefficient is obtained, to obtain the current frequency change amount.

[0124] The calculation formula is as follows:

[0125] ΔUF = Kp × (eTs(t) - eTs(t-1)) + Ki × eTs(t)

[0126] Wherein, eTs(t) represents the current temperature loss value, eTs(t-1) represents the temperature loss value determined in the last period, and eTs(t) - eTs(t-1) is the temperature loss difference value.

[0127] Further, please continue to refer to Figure 5 The compressor 120 operating frequency control method can further include:

[0128] In step S203, the operating frequency of the compressor 120 is adjusted according to the frequency change amount.

[0129] After obtaining the frequency change amount through step S202, the operating frequency of the compressor 120 is adjusted, corresponding to increasing or decreasing the frequency change amount. For example, if the frequency change amount is -5 Hz, the operating frequency of the compressor 120 is reduced by 5 Hz.

[0130] The controller 110 executes the compressor 120 operating frequency control method provided in the embodiment, which can calculate the low-pressure saturation temperature as a control basis for adjusting the operating frequency of the compressor 120 without relying on the low-pressure sensor, realize accurate control of the low-pressure temperature of the compressor 120, and improve the performance of the air conditioner.

[0131] The air conditioner 100 provided in the embodiment, the controller 110 is further used to execute the outdoor fan 130 rotating speed control method, please refer toFigure 8 , Figure 8 Fig. 3 shows a flow chart of the method for controlling the rotation speed of the outdoor fan 130 according to the present embodiment. The method for controlling the rotation speed of the outdoor fan 130 can include the following steps:

[0132] In step S301, the low-pressure saturation temperature of the air conditioner 100 is obtained.

[0133] The low-pressure saturation temperature is obtained according to the method for obtaining the low-pressure saturation temperature described above.

[0134] In step S302, the low-pressure pressure is determined according to the low-pressure saturation temperature.

[0135] In the present embodiment, after obtaining the low-pressure saturation temperature, the controller 110 inputs the low-pressure saturation temperature into the "pressure-saturation temperature corresponding graph" of the reaction pressure and the saturation temperature, and thus the corresponding low-pressure pressure is obtained.

[0136] In step S303, the rotation speed of the outdoor fan 130 of the air conditioner 100 is adjusted according to the low-pressure pressure.

[0137] Please refer to Figure 9 , Figure 9 Fig. 4 shows a flow chart of a sub-step of step S303. Step S303 can include the following sub-steps:

[0138] In sub-step S3031, if the low-pressure pressure is less than a first preset pressure value, the current rotation speed of the outdoor fan 130 is maintained for a preset time period, and then the rotation speed is increased by one level.

[0139] In sub-step S3032, if the low-pressure pressure is greater than or equal to the first preset pressure value and less than or equal to a second preset pressure value, the current rotation speed of the outdoor fan 130 is maintained.

[0140] In sub-step S3033, if the low-pressure pressure is greater than the second preset pressure value, the current rotation speed of the outdoor fan 130 is maintained for a preset time period, and then the rotation speed is decreased by one level.

[0141] In the present embodiment, the first preset pressure value is 9.3 bar, the preset time period is 30 s, and the second preset pressure value is 10.6 bar.

[0142] In fact, before step S303, the method for controlling the rotation speed of the outdoor fan 130 according to the present embodiment can further include a step of obtaining the high-pressure pressure of the air conditioner 100, which is detected by a high-pressure sensor that is also a configuration of the air conditioner 100. Please refer to Figure 10 , Figure 10 Fig. 5 shows another flow chart of a sub-step of step S303. Step S303 can further include the following sub-steps:

[0143] In sub-step S3034, the rotation speed of the outdoor fan 130 is adjusted according to the low pressure and the high pressure.

[0144] Please refer to Figure 11 , Figure 11 Fig. 4 shows a flow chart of one sub-step of sub-step S3034, which can include the following sub-steps:

[0145] In sub-step S3034a, if the low pressure is less than or equal to a third preset pressure value and the high pressure is less than or equal to a fourth preset pressure value, the rotation speed of the outdoor fan 130 is adjusted to the maximum number.

[0146] In sub-step S3034b, if the high pressure is greater than or equal to a sixth preset pressure value, the rotation speed of the outdoor fan 130 is limited to increase, and the limitation is released when the high pressure is reduced to be less than or equal to a fifth preset pressure value.

[0147] In sub-step S3034c, if the high pressure is greater than or equal to a seventh preset pressure value, the rotation speed of the outdoor fan 130 is adjusted to the minimum number and locked, and the lock is released when the high pressure is reduced to be less than or equal to the fifth preset pressure value.

[0148] It should be noted that when the high pressure and / or the low pressure do not satisfy the conditions of any one of sub-step S3034a, sub-step S3034b and sub-step S3034c, the rotation speed of the outdoor fan 130 is adjusted according to sub-step S3031, sub-step S3032 and sub-step S3033.

[0149] The fourth preset pressure value, the fifth preset pressure value, the sixth preset pressure value and the seventh preset pressure value increase in turn. In this embodiment, the third preset pressure value is 4.8 bar, the fourth preset pressure value is 26.4 bar, the fifth preset pressure value is 32 bar, the sixth preset pressure value is 33.5 bar, and the sixth preset pressure value is 35 bar.

[0150] In this embodiment, the outdoor fan 130 adopts the structure of combination of an upper fan and a lower fan, and the corresponding relationship between the number and the rotation speed is as follows:

[0151]

[0152] It should be noted that in order to avoid excessive frequent adjustment of the rotation speed of the outdoor fan 130, in this embodiment, after the rotation speed of the outdoor fan 130 is adjusted to a certain number, it needs to run at the rotation speed corresponding to the number for at least 30s, i.e. it cannot be adjusted again within 30s after any adjustment.

[0153] The controller 110 executes the external fan 130 rotating speed control method provided by the embodiment, can obtain the low pressure saturation temperature as the control basis according to the existing sensor without relying on the low pressure sensor to adjust the rotating speed of the external fan 130, realizes the accurate control of the low pressure of the compressor 120, guarantees the stability of the low pressure, and improves the air conditioning performance.

[0154] Although the present application has been disclosed as above, it is not limited to the above. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and the protection scope of the present application should be limited by the scope defined by the claims.

Claims

1. A method of obtaining a low-pressure saturation temperature, characterized by, The method comprises the following steps: obtaining corresponding operation parameters according to the operation mode of the air conditioner (100); determining the pressure loss compensation coefficient according to the operation mode of the air conditioner (100) and the operation frequency of the compressor (120); calculating the difference between the operation parameters and the pressure loss compensation coefficient to obtain the low-pressure saturation temperature; the operation parameters include the lowest inlet temperature and the outdoor coil temperature, and the step of obtaining corresponding operation parameters according to the operation mode of the air conditioner (100) comprises: if the air conditioner (100) operates in a cooling mode or a dehumidifying mode, obtaining the inlet temperature of all operating indoor units, and comparing the obtained multiple inlet temperatures to obtain the lowest inlet temperature; if the air conditioner (100) operates in a heating mode, obtaining the coil temperature of the outdoor heat exchanger to obtain the outdoor coil temperature.

2. The low-pressure saturation temperature acquisition method according to claim 1, characterized by, The air conditioner (100) has pre-stored a first correspondence relationship between the frequency range of the compressor (120) and the pressure loss compensation coefficient, and the step of determining the pressure loss compensation coefficient according to the operation mode of the air conditioner (100) and the operation frequency of the compressor (120) comprises: if the air conditioner (100) operates in a cooling mode or a dehumidifying mode, determining the pressure loss compensation coefficient corresponding to the frequency range in which the operation frequency of the compressor (120) is located according to the first correspondence relationship.

3. The low-pressure saturation temperature acquisition method according to claim 1, characterized by, The air conditioner (100) has pre-stored a second correspondence relationship between the frequency range of the compressor (120) and the pressure loss compensation coefficient, and the step of determining the pressure loss compensation coefficient according to the operation mode of the air conditioner (100) and the operation frequency of the compressor (120) comprises: if the air conditioner (100) operates in a heating mode, determining the pressure loss compensation coefficient corresponding to the frequency range in which the operation frequency of the compressor (120) is located according to the second correspondence relationship.

4. A method of controlling the operating frequency of a compressor, characterized by, The method comprises the following steps: periodically obtaining the low-pressure saturation temperature and the average inlet temperature of the air conditioner (100), wherein the low-pressure saturation temperature is obtained according to the low-pressure saturation temperature obtaining method in any one of claims 1-3; determining the frequency change amount according to the obtained low-pressure saturation temperature and average inlet temperature; adjusting the operation frequency of the compressor (120) according to the frequency change amount.

5. The method of claim 4, wherein, The step of periodically obtaining the low-pressure saturation temperature and the average inlet temperature of the air conditioner (100) comprises: periodically obtaining the inlet temperature of all operating indoor units; calculating the average value of the obtained multiple inlet temperatures to obtain the average inlet temperature.

6. The method of claim 4, wherein, within the first time length after the air conditioner (100) is started, or within the second time length after the total capacity of the operating indoor units changes, the third time length is used as the control period, otherwise, the fourth time length is used as the control period.

7. The method of claim 4, wherein the frequency of operation of the compressor is controlled by the controller based on the sensed temperature of the refrigerant in the evaporator. The step of determining the frequency change amount according to the obtained low-pressure saturation temperature and average inlet temperature comprises: calculating the difference between the average inlet temperature and the low-pressure saturation temperature to obtain the temperature loss value; calculating the difference between the current temperature loss value and the temperature loss value obtained in the previous period to obtain the temperature loss difference value; determining a first correction coefficient and a second correction coefficient according to the frequency variation amount determined in the previous cycle; calculating a product of the temperature loss difference and the first correction coefficient, adding a product of the current temperature loss value and the second correction coefficient, and obtaining a sum value as the current frequency variation amount.

8. The method of claim 7, wherein, The step of determining a first correction coefficient and a second correction coefficient according to the frequency variation amount determined in the previous cycle comprises: if the ratio of the total capacity of all indoor units in refrigeration operation to the capacity of the outdoor unit is less than or equal to a first ratio value, determining the first correction coefficient and the second correction coefficient according to the range of the frequency variation amount determined in the previous cycle; if the ratio of the total capacity of all indoor units in refrigeration operation to the capacity of the outdoor unit is greater than the first ratio value, determining the first correction coefficient and the second correction coefficient according to the relationship between the low-pressure saturation temperature and the average inlet temperature and the range of the frequency variation amount determined in the previous cycle.

9. An outer fan rotation speed control method characterized by comprising: comprises: obtaining a low-pressure saturation temperature of an air conditioner (100), wherein the low-pressure saturation temperature is obtained according to the low-pressure saturation temperature obtaining method in any one of claims 1-3; determining a low-pressure pressure according to the low-pressure saturation temperature; adjusting the rotation speed of an outdoor fan (130) of the air conditioner (100) according to the low-pressure pressure.

10. The method of claim 9, wherein The step of adjusting the rotation speed of the outdoor fan (130) of the air conditioner (100) according to the low-pressure pressure comprises: if the low-pressure pressure is less than a first preset pressure value, maintaining the current rotation speed of the outdoor fan (130) for a preset time length, and then increasing the rotation speed by one level; if the low-pressure pressure is greater than or equal to the first preset pressure value and less than or equal to a second preset pressure value, maintaining the current rotation speed of the outdoor fan (130); if the low-pressure pressure is greater than the second preset pressure value, maintaining the current rotation speed of the outdoor fan (130) for the preset time length, and then decreasing the rotation speed by one level.

11. The method of claim 9, wherein The outdoor fan (130) rotation speed control method further comprises: obtaining a high-pressure pressure of the air conditioner (100); The step of adjusting the rotation speed of the outdoor fan (130) of the air conditioner (100) according to the low-pressure pressure further comprises: adjusting the rotation speed of the outdoor fan (130) of the air conditioner (100) according to the low-pressure pressure and the high-pressure pressure.

12. The method of claim 11, wherein The step of adjusting the rotation speed of the outdoor fan (130) of the air conditioner (100) according to the low-pressure pressure and the high-pressure pressure comprises: if the low-pressure pressure is less than or equal to a third preset pressure value and the high-pressure pressure is less than or equal to a fourth preset pressure value, adjusting the rotation speed of the outdoor fan (130) to the maximum level; if the high-pressure pressure is greater than or equal to a sixth preset pressure value, limiting the increase of the rotation speed of the outdoor fan (130), and releasing the limitation when the high-pressure pressure decreases to be less than or equal to a fifth preset pressure value; if the high-pressure pressure is greater than or equal to a seventh preset pressure value, adjusting the rotation speed of the outdoor fan (130) to the minimum level and locking, and releasing the locking when the high-pressure pressure decreases to be less than or equal to the fifth preset pressure value; The fourth preset pressure value, the fifth preset pressure value, the sixth preset pressure value and the seventh preset pressure value increase in sequence.

13. An air conditioner characterized by comprising: The application further provides a controller (110) for executing the low-pressure saturation temperature acquisition method according to any one of claims 1-3, or the compressor operating frequency control method according to any one of claims 4-8, or the outdoor fan rotating speed control method according to any one of claims 9-12.

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