An air conditioner and a frequency control method thereof

Abstract

The present invention discloses an air conditioner and a frequency control method for the air conditioner. After the air conditioner receives a refrigeration start command, it obtains the outdoor ambient temperature; when the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, it controls the air conditioner to execute a high-temperature refrigeration frequency control mode; in the high-temperature refrigeration frequency control mode, it obtains the initial operating frequency of the compressor according to the outdoor ambient temperature and a preset degree of subcooling; after the compressor operates at the initial operating frequency for a first preset time, it obtains the outdoor coil temperature and the indoor coil temperature; it obtains the high-side pressure of the air conditioner according to the outdoor coil temperature, obtains the low-side pressure of the air conditioner according to the indoor coil temperature, and calculates the compression ratio of the compressor according to the high-side pressure and the low-side pressure; it controls the operating frequency of the compressor according to the high-side pressure and the compression ratio; it can reduce the mechanical loss of the compressor, thereby improving the reliability of the compressor during refrigeration operation under high-temperature conditions and extending the service life of the compressor.

Description

Technical Field

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

[0002] When an air conditioner operates in a high-temperature environment, the system load is large, and the wear of the compressor increases accordingly. If the operating frequency of the compressor exceeds the allowable frequency range of the compressor, it will cause the exhaust pressure and compression ratio of the compressor to be too large, thereby accelerating the loss of mechanical components of the compressor, causing damage to the compressor, and further resulting in poor operating reliability of the compressor and affecting the service life of the compressor. Summary of the Invention

[0003] An object of an embodiment of the present invention is to provide an air conditioner and a frequency control method for an air conditioner, which can reduce the mechanical loss of the compressor, thereby improving the reliability of the compressor during refrigeration operation under high-temperature conditions and extending the service life of the compressor.

[0004] To achieve the above object, an embodiment of the present invention provides an air conditioner, which includes:

[0005] A refrigerant circuit in which refrigerant circulates in a refrigeration cycle through a compressor, a condenser, a throttling component, and an evaporator in sequence, where one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger;

[0006] A first temperature sensor for collecting the outdoor ambient temperature;

[0007] A second temperature sensor for collecting the outdoor coil temperature of the outdoor heat exchanger;

[0008] A third temperature sensor for collecting the indoor coil temperature of the indoor heat exchanger;

[0009] A controller for:

[0010] After the air conditioner receives a refrigeration start instruction, obtaining the outdoor ambient temperature;

[0011] When the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, controlling the air conditioner to execute a high-temperature refrigeration frequency control mode;

[0012] In the high-temperature refrigeration frequency control mode, obtaining an initial operating frequency of the compressor according to the outdoor ambient temperature and a preset degree of subcooling, and controlling the compressor to operate at the initial operating frequency;

[0013] After the compressor operates at the initial operating frequency for a first preset time, obtaining the outdoor coil temperature and the indoor coil temperature;

[0014] Obtain the high-pressure side pressure of the air conditioner according to the outdoor coil temperature, obtain the low-pressure side pressure of the air conditioner according to the indoor coil temperature, and calculate the compression ratio of the compressor according to the high-pressure side pressure and the low-pressure side pressure;

[0015] Control the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio.

[0016] Further, the controller obtains the initial operating frequency of the compressor according to the outdoor ambient temperature and a preset degree of subcooling, specifically including:

[0017] Calculate the sum value of the outdoor ambient temperature and the preset degree of subcooling;

[0018] Query the temperature-pressure correspondence table according to the sum value to obtain the saturation pressure value corresponding to the sum value;

[0019] Query the pressure-rotational speed correspondence table according to the saturation pressure value to obtain the operating rotational speed corresponding to the saturation pressure value;

[0020] Calculate the initial operating frequency of the compressor according to the operating rotational speed.

[0021] Further, the controller is also used for:

[0022] Obtain the minimum operating frequency and the maximum operating frequency allowed for the compressor at the corresponding outdoor ambient temperature;

[0023] Then, after the controller obtains the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset degree of subcooling, it is also used for:

[0024] Compare the initial operating frequency with the minimum operating frequency and the maximum operating frequency;

[0025] When the minimum operating frequency ≤ the initial operating frequency ≤ the maximum operating frequency, keep the initial operating frequency unchanged;

[0026] When the initial operating frequency < the minimum operating frequency, configure the minimum operating frequency as the initial operating frequency;

[0027] When the initial operating frequency > the maximum operating frequency, configure the maximum operating frequency as the initial operating frequency.

[0028] Further, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0029] When the high-pressure side pressure = the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, keep the initial operating frequency unchanged and control the compressor to continue operating at the initial operating frequency;

[0030] After the compressor continues to operate at the initial operating frequency for a first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0031] Further, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0032] When the high-pressure side pressure < the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, increase the operating frequency of the compressor from the initial operating frequency to the first operating frequency, and control the compressor to continue operating at the first operating frequency; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency;

[0033] After the compressor continues to operate at the first operating frequency for a first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0034] Further, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0035] When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, decrease the operating frequency of the compressor from the initial operating frequency to the second operating frequency, and control the compressor to continue operating at the second operating frequency; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency;

[0036] After the compressor operates at the second operating frequency for a first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0037] Further, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0038] When the high-pressure side pressure = the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, keep the initial operating frequency unchanged, control the compressor to continue operating at the initial operating frequency, and control the throttling component to increase by a preset number of steps;

[0039] After the compressor continues to operate at the initial operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

[0040] Further, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0041] When the high-pressure side pressure < the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, the operating frequency of the compressor is increased from the initial operating frequency to a first operating frequency, the compressor is controlled to continue to operate at the first operating frequency, and the throttling component is controlled to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency;

[0042] After the compressor operates at the first operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

[0043] Further, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0044] When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, the operating frequency of the compressor is decreased from the initial operating frequency to a second operating frequency, the compressor is controlled to continue to operate at the second operating frequency, and the throttling component is controlled to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency;

[0045] After the compressor operates at the second operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

[0046] To achieve the above object, an embodiment of the present invention further provides a frequency control method for an air conditioner, which is applicable to the air conditioner described in any one of the above, and the method is executed by the controller, and the method includes:

[0047] After the air conditioner receives a refrigeration start instruction, the outdoor ambient temperature is acquired;

[0048] When the outdoor ambient temperature reaches the preset high-temperature ambient temperature limit value, the air conditioner is controlled to execute a high-temperature refrigeration frequency control mode;

[0049] In the high-temperature refrigeration frequency control mode, obtain the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset subcooling degree, and control the compressor to operate at the initial operating frequency;

[0050] After the compressor operates at the initial operating frequency for a first preset time, obtain the outdoor coil temperature and the indoor coil temperature;

[0051] Obtain the high-side pressure of the air conditioner according to the outdoor coil temperature, obtain the low-side pressure of the air conditioner according to the indoor coil temperature, and calculate the compression ratio of the compressor according to the high-side pressure and the low-side pressure;

[0052] Control the operating frequency of the compressor according to the high-side pressure and the compression ratio.

[0053] Compared with the prior art, an air conditioner and a frequency control method for an air conditioner provided by an embodiment of the present invention. The air conditioner includes a refrigerant circuit in which refrigerant circulates in sequence through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; it further includes a first temperature sensor for collecting the outdoor ambient temperature; it further includes a second temperature sensor for collecting the outdoor coil temperature of the outdoor heat exchanger; it further includes a third temperature sensor for collecting the indoor coil temperature of the indoor heat exchanger; it further includes a controller for: after the air conditioner receives a refrigeration start instruction, obtain the outdoor ambient temperature; when the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, control the air conditioner to execute the high-temperature refrigeration frequency control mode; in the high-temperature refrigeration frequency control mode, obtain the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset subcooling degree, and control the compressor to operate at the initial operating frequency; after the compressor operates at the initial operating frequency for a first preset time, obtain the outdoor coil temperature and the indoor coil temperature; obtain the high-side pressure of the air conditioner according to the outdoor coil temperature, obtain the low-side pressure of the air conditioner according to the indoor coil temperature, and calculate the compression ratio of the compressor according to the high-side pressure and the low-side pressure; control the operating frequency of the compressor according to the high-side pressure and the compression ratio. By adopting the high-temperature refrigeration frequency control mode, the embodiment of the present invention can timely adjust the operating frequency of the compressor according to the changes in pressure and compression ratio, so that both the high-side pressure and the compression ratio of the air-conditioning system fall within the range required by the compressor, which can reduce the mechanical loss of the compressor, thereby improving the reliability of the compressor during refrigeration operation under high-temperature conditions and extending the service life of the compressor. Description of the Drawings

[0054] Figure 1 is an external structural schematic diagram of an air conditioner provided by an embodiment of the present invention;

[0055] Figure 2 It is a schematic diagram of the internal structure of an air conditioner provided by an embodiment of the present invention;

[0056] Figure 3 It is a flowchart of the operation of a controller of an air conditioner provided by an embodiment of the present invention;

[0057] Figure 4 It is another flowchart of the operation of a controller of an air conditioner provided by an embodiment of the present invention;

[0058] Figure 5 It is a corresponding relationship diagram between the exhaust pressure and the operating speed of a compressor of an air conditioner provided by an embodiment of the present invention;

[0059] Figure 6 It is yet another flowchart of the operation of a controller of an air conditioner provided by an embodiment of the present invention;

[0060] Figure 7 It is yet another flowchart of the operation of a controller of an air conditioner provided by an embodiment of the present invention;

[0061] Figure 8 It is yet another flowchart of the operation of a controller of an air conditioner provided by an embodiment of the present invention;

[0062] Figure 9 It is a schematic flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention;

[0063] Figure 10 It is another schematic flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention;

[0064] Figure 11 It is yet another schematic flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention;

[0065] Figure 12 It is yet another schematic flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention;

[0066] Figure 13 It is yet another schematic flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention. Specific embodiments

[0067] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art in the technical field of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0068] SeeFigure 1 and Figure 2 as shown, wherein Figure 1 is a schematic diagram of the external structure of an air conditioner provided by an embodiment of the present invention, Figure 2 is a schematic diagram of the internal structure of an air conditioner provided by an embodiment of the present invention; as Figure 1 shown, the external structure of the air conditioner includes an indoor unit 100 and an outdoor unit 200. Among them, the indoor unit 100 is used to adjust the temperature and humidity of indoor air. The outdoor unit 200 is connected to the indoor unit 100 through a connecting pipe. The indoor unit 100 is generally installed indoors, and the outdoor unit 200 is generally installed outdoors. As Figure 2 shown, the indoor unit 100 of the air conditioner includes an indoor heat exchanger, an indoor fan, and an indoor fan motor; among them, the indoor heat exchanger can achieve a refrigeration effect by performing heat exchange with indoor air by using the latent heat of evaporation of the refrigerant; the indoor fan is driven by the indoor fan motor and can generate an air flow of indoor air passing through the indoor heat exchanger to promote the heat exchange between the refrigerant flowing in the heat transfer pipe and the indoor air. The outdoor unit 200 of the air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, a throttling component, an outdoor fan, and an outdoor fan motor; among them, the compressor is used to compress the refrigerant gas with low temperature and low pressure into a refrigerant gas with high temperature and high pressure; the four-way valve is used to control the flow direction of the refrigerant in the refrigerant circuit so that the outdoor heat exchanger and the indoor heat exchanger are switched between being a condenser and an evaporator; the outdoor heat exchanger is used to perform heat exchange between the refrigerant flowing inside and the outdoor air; the throttling component is used to throttle the refrigerant flowing through; the outdoor fan is driven by the outdoor fan motor and can generate an air flow of outdoor air passing through the outdoor heat exchanger to promote the heat exchange between the refrigerant flowing in the heat transfer pipe and the outdoor air.

[0069] Combined with Figure 2 shown, in an embodiment of the present invention, the air conditioner includes a refrigerant circuit in which the refrigerant circulates in sequence through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle. One of the condenser and the evaporator is the outdoor heat exchanger, and the other is the indoor heat exchanger.

[0070] Combined with Figure 2 shown, in an embodiment of the present invention, the air conditioner further includes a first temperature sensor, a second temperature sensor, and a third temperature sensor. Among them, the first temperature sensor is used to collect the outdoor ambient temperature and is generally installed on the outdoor heat exchanger; the second temperature sensor is used to collect the outdoor coil temperature of the outdoor heat exchanger and is generally installed on the surface of the outdoor heat exchanger; the third temperature sensor is used to collect the indoor coil temperature of the indoor heat exchanger and is generally installed on the surface of the indoor heat exchanger.

[0071] In an embodiment of the present invention, the air conditioner further includes a controller, which is communicatively connected to the compressor, the first temperature sensor, the second temperature sensor, and the third temperature sensor respectively. The controller is configured to perform corresponding control on the air conditioner by adopting the technical solution provided by the embodiment of the present invention.

[0072] As an optional embodiment, the controller is configured to:

[0073] After the air conditioner receives a refrigeration start instruction, obtain the outdoor ambient temperature;

[0074] When the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, control the air conditioner to execute a high-temperature refrigeration frequency control mode;

[0075] In the high-temperature refrigeration frequency control mode, obtain the initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, and control the compressor to operate at the initial operating frequency;

[0076] After the compressor operates at the initial operating frequency for a first preset time, obtain the outdoor coil temperature and the indoor coil temperature;

[0077] Obtain the high-pressure side pressure of the air conditioner according to the outdoor coil temperature, obtain the low-pressure side pressure of the air conditioner according to the indoor coil temperature, and calculate the compression ratio of the compressor according to the high-pressure side pressure and the low-pressure side pressure;

[0078] Control the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio.

[0079] Combined Figure 3 As shown, it is a working flowchart of a controller of an air conditioner provided by an embodiment of the present invention. When the embodiment of the present invention is specifically implemented, the specific working process of the controller is as follows: After the air conditioner receives a refrigeration start instruction ( Figure 3 step S11 shown), the outdoor ambient temperature Tout is acquired in real time through the first temperature sensor ( Figure 3 step S12 shown), and the obtained outdoor ambient temperature Tout is compared with a preset high-temperature ambient temperature limit value Tg to determine whether the outdoor ambient temperature Tout reaches the preset high-temperature ambient temperature limit value Tg. For example, it is determined whether the outdoor ambient temperature Tout is greater than or equal to the preset high-temperature ambient temperature limit value Tg ( Figure 3 step S13 shown); when it is determined that the outdoor ambient temperature Tout reaches the preset high-temperature ambient temperature limit value Tg, control the air conditioner to execute a high-temperature refrigeration frequency control mode ( Figure 3the step S14) shown; in the high-temperature refrigeration frequency control mode, obtain the initial operating frequency f0 of the compressor according to the obtained outdoor ambient temperature Tout and the preset supercooling degree △T, and control the compressor to operate at the initial operating frequency f0( Figure 3 the step S15) shown; time the operating time of the compressor. After the compressor operates at the initial operating frequency f0 for the first preset time t1, obtain the outdoor coil temperature Tpo in real time through the second temperature sensor, and obtain the indoor coil temperature Tpi in real time through the third temperature sensor Figure 3 the step S16) shown; obtain the high-side pressure Pg of the air conditioner according to the obtained outdoor coil temperature Tpo, obtain the low-side pressure Pd of the air conditioner according to the obtained indoor coil temperature Tpi, and calculate the compression ratio φ of the compressor according to the obtained high-side pressure Pg and low-side pressure Pd Figure 3 the step S17) shown, where φ = Pg / Pd; control the operating frequency of the compressor according to the obtained high-side pressure Pg and the calculated compression ratio φ Figure 3 the step S18) shown.

[0080] It should be noted that the high-temperature environmental temperature limit value Tg and the supercooling degree △T can be preset and stored in the controller or memory for the convenience of the controller to retrieve at any time when needed; by way of example, Tg = 39°C, △T = 5°C, or the high-temperature environmental temperature limit value Tg and the supercooling degree △T can also be set according to actual needs, and the embodiments of the present invention do not make specific limitations.

[0081] It can be understood that after obtaining the outdoor ambient temperature Tout in the embodiments of the present invention, comparing the obtained outdoor ambient temperature Tout with the preset high-temperature environmental temperature limit value Tg is to determine whether the air conditioner meets the high-temperature working condition. When Tout ≥ Tg, it is determined that the air conditioner meets the high-temperature working condition, and then the air conditioner is controlled to execute the high-temperature refrigeration frequency control mode; when Tout < Tg, it is determined that the air conditioner does not meet the high-temperature working condition, and then the air conditioner is controlled to exit the high-temperature refrigeration frequency control mode.

[0082] It should be noted that when obtaining the high-side pressure Pg of the air conditioner according to the obtained outdoor coil temperature Tpo in the embodiments of the present invention, the "temperature-pressure correspondence table" can be queried according to the outdoor coil temperature Tpo (the "temperature-pressure correspondence table" can be preset and stored in the controller or memory for the convenience of the controller to retrieve at any time when needed. The "temperature-pressure correspondence table" reflects the one-to-one correspondence between the temperature of the refrigerant and the saturation pressure, and the higher the temperature, the higher the corresponding saturation pressure. Different types of refrigerants have different "temperature-pressure correspondence tables"), so as to find out the corresponding saturation pressure according to the outdoor coil temperature Tpo, and accordingly obtain the condensation pressure of the air conditioning system, that is, obtain the high-side pressure Pg of the air conditioning system. Among them, if the difference between the outdoor coil temperature Tpo and the actual refrigerant temperature is considered, the saturation pressure obtained by looking up the table can also be corrected accordingly by increasing the correction coefficient or correction amount, and the corrected saturation pressure is used as the high-side pressure Pg of the air conditioning system.

[0083] Similarly, when obtaining the low-side pressure Pd of the air conditioner according to the obtained indoor coil temperature Tpi in the embodiments of the present invention, the "temperature-pressure correspondence table" can be queried according to the indoor coil temperature Tpi, so as to find out the corresponding saturation pressure according to the indoor coil temperature Tpi, and accordingly obtain the evaporation pressure of the air conditioning system, that is, obtain the low-side pressure Pd of the air conditioning system. Among them, if the difference between the indoor coil temperature Tpi and the actual refrigerant temperature is considered, the saturation pressure obtained by looking up the table can also be corrected accordingly by increasing the correction coefficient or correction amount, and the corrected saturation pressure is used as the low-side pressure Pd of the air conditioning system.

[0084] An air conditioner provided by an embodiment of the present invention includes a refrigerant circuit in which refrigerant circulates in a refrigeration cycle through a compressor, a condenser, a throttling component, and an evaporator in sequence. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger. It further includes a first temperature sensor for collecting the outdoor ambient temperature, a second temperature sensor for collecting the outdoor coil temperature of the outdoor heat exchanger, a third temperature sensor for collecting the indoor coil temperature of the indoor heat exchanger, and a controller for: after the air conditioner receives a refrigeration start instruction, obtaining the outdoor ambient temperature; when the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, controlling the air conditioner to execute a high-temperature refrigeration frequency control mode; in the high-temperature refrigeration frequency control mode, obtaining an initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, and controlling the compressor to operate at the initial operating frequency; after the compressor operates at the initial operating frequency for a first preset time, obtaining the outdoor coil temperature and the indoor coil temperature; obtaining the high-pressure side pressure of the air conditioner according to the outdoor coil temperature, obtaining the low-pressure side pressure of the air conditioner according to the indoor coil temperature, and calculating the compression ratio of the compressor according to the high-pressure side pressure and the low-pressure side pressure; controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio. By adopting the high-temperature refrigeration frequency control mode, the embodiment of the present invention can timely adjust the operating frequency of the compressor according to the changes in pressure and compression ratio, so that both the high-pressure side pressure and the compression ratio of the air-conditioning system fall within the range required by the compressor, which can reduce the mechanical loss of the compressor, thereby improving the reliability of the compressor during refrigeration operation under high-temperature conditions and extending the service life of the compressor.

[0085] As an optional embodiment, the controller obtains the initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, which specifically includes:

[0086] Calculating the sum value of the outdoor ambient temperature and the preset supercooling degree;

[0087] Querying a temperature-pressure correspondence table according to the sum value to obtain the saturation pressure value corresponding to the sum value;

[0088] Querying a pressure-speed correspondence table according to the saturation pressure value to obtain the operating speed corresponding to the saturation pressure value;

[0089] Calculating the initial operating frequency of the compressor according to the operating speed.

[0090] Combined with Figure 4As shown in the figure, it is another working flowchart of a controller of an air conditioner provided by an embodiment of the present invention. On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, when the controller obtains the initial operating frequency f0 of the compressor according to the obtained outdoor ambient temperature Tout and the preset supercooling degree △T, it can first calculate the sum value (Tout + △T) of the two according to the obtained outdoor ambient temperature Tout and the preset supercooling degree △T ( Figure 4 as shown in step S151), and then query the "temperature-pressure correspondence table" according to the calculated sum value (Tout + △T) of the two, so as to find out the corresponding saturation pressure value according to the sum value (Tout + △T) ( Figure 4 as shown in step S152), and then query the "pressure-speed correspondence table" according to the saturation pressure value (the "pressure-speed correspondence table" can be preset and stored in the controller or memory for the controller to retrieve at any time when needed, and the "pressure-speed correspondence table" reflects the correspondence between the discharge pressure of the compressor and the operating speed of the compressor), so as to find out the corresponding operating speed according to the saturation pressure value ( Figure 4 as shown in step S153), and calculate the initial operating frequency f0 of the compressor according to the operating speed ( Figure 4 as shown in step S154).

[0091] It should be noted that the correspondence between the operating speed and the operating frequency of the compressor is: operating frequency = operating speed / 60. Based on this calculation formula, the initial operating frequency f0 of the compressor can be calculated according to the found operating speed.

[0092] See Figure 5 As shown in the figure, it is a correspondence diagram between the discharge pressure and the operating speed of a compressor of an air conditioner provided by an embodiment of the present invention. The "pressure-speed correspondence table" can be obtained by corresponding conversion and stored according to the curve graph in the compressor specification book shown in Figure 5 As can be seen from Figure 5 , a pressure value may correspond to one speed value, or may correspond to two (or even more) speed values. When a pressure value corresponds to only one speed value, directly use this speed value as the query result; when a pressure value corresponds to two (or even more) speed values, directly use the smallest speed value among the two (or even more) speed values as the query result.

[0093] As one of the optional embodiments, the controller is further configured to:

[0094] Obtain the minimum operating frequency and the maximum operating frequency allowed by the compressor at the corresponding outdoor ambient temperature;

[0095] Then, after obtaining the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset supercooling degree, the controller is further configured to:

[0096] Compare the initial operating frequency with the minimum operating frequency and the maximum operating frequency;

[0097] When the minimum operating frequency ≤ the initial operating frequency ≤ the maximum operating frequency, keep the initial operating frequency unchanged;

[0098] When the initial operating frequency < the minimum operating frequency, configure the minimum operating frequency as the initial operating frequency;

[0099] When the initial operating frequency > the maximum operating frequency, configure the maximum operating frequency as the initial operating frequency.

[0100] Combined Figure 6 shown, is another working flowchart of a controller of an air conditioner provided by an embodiment of the present invention. On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, after the controller obtains the initial operating frequency f0 of the compressor according to the outdoor ambient temperature Tout and the preset supercooling degree △T, it is further configured to: obtain the minimum operating frequency fmin and the maximum operating frequency fmax allowed for the compressor at the corresponding outdoor ambient temperature (i.e., the outdoor ambient temperature Tout obtained by real-time acquisition in the above embodiment) Figure 6 shown in step S155), and compare the initial operating frequency f0 of the compressor with the obtained minimum operating frequency fmin and the obtained maximum operating frequency fmax respectively, to determine whether the initial operating frequency f0 of the compressor satisfies: minimum operating frequency fmin ≤ initial operating frequency f0 ≤ maximum operating frequency fmax Figure 6 shown in step S1551); when it is determined that the initial operating frequency f0 of the compressor satisfies the minimum operating frequency fmin ≤ initial operating frequency f0 ≤ maximum operating frequency fmax, keep the initial operating frequency f0 of the compressor unchanged Figure 6 shown in step S1552); when it is determined that the initial operating frequency f0 of the compressor does not satisfy the minimum operating frequency fmin ≤ initial operating frequency f0 ≤ maximum operating frequency fmax, further determine whether the initial operating frequency f0 of the compressor satisfies: initial operating frequency f0 < minimum operating frequency fmin Figure 6 shown in step S1553), when it is determined that the initial operating frequency f0 of the compressor satisfies the initial operating frequency f0 < minimum operating frequency fmin, it is necessary to correct the initial operating frequency f0 of the compressor, then configure the obtained minimum operating frequency fmin as the initial operating frequency f0 of the compressor, that is, let f0 = fmin Figure 6the step S1554) shown; when it is determined that the initial operating frequency f0 of the compressor does not satisfy the condition that the initial operating frequency f0 < the minimum operating frequency fmin, it is further determined whether the initial operating frequency f0 of the compressor satisfies: the initial operating frequency f0 > the maximum operating frequency fmax Figure 6 the step S1555) shown; when it is determined that the initial operating frequency f0 of the compressor satisfies the condition that the initial operating frequency f0 > the maximum operating frequency fmax, the initial operating frequency f0 of the compressor needs to be corrected, and then the obtained maximum operating frequency fmax is configured as the initial operating frequency f0 of the compressor, that is, let f0 = fmax Figure 6 the step S1556) shown.

[0101] It should be noted that the minimum operating frequency fmin is the minimum operating frequency corresponding to the compressor running stably under the premise of increasing torque compensation at the corresponding outdoor ambient temperature Tout and the corresponding highest indoor ambient temperature of the air conditioner; the maximum operating frequency fmax is the maximum operating frequency corresponding to the compressor reaching the limit exhaust pressure Pmax at the corresponding outdoor ambient temperature Tout and the corresponding highest indoor ambient temperature of the air conditioner. It is required that the initial operating frequency f0 of the compressor needs to satisfy: the minimum operating frequency fmin ≤ the initial operating frequency f0 ≤ the maximum operating frequency fmax.

[0102] Among them, both the minimum operating frequency fmin and the maximum operating frequency fmax are frequencies that can be determined in the debugging of the compressor drive reliability test. When debugging the compressor drive reliability, generally an outdoor ambient temperature and a corresponding indoor ambient temperature are set as the debugging conditions, and this debugging condition is generally the most severe indoor unit condition, so that the load of the compressor running under this debugging condition is the maximum value; exemplarily, generally the indoor ambient temperature ≥ 32°C, or the indoor ambient temperature can also be set according to actual needs, and the embodiments of the present invention do not make specific limitations.

[0103] As one optional embodiment, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0104] When the high-pressure side pressure = the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, keep the initial operating frequency unchanged and control the compressor to continue running at the initial operating frequency;

[0105] After the compressor continues to run at the initial operating frequency for the first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0106] Among them, the preset exhaust pressure limit value can be calculated based on the ultimate exhaust pressure Pmax of the compressor (for example, Pmax = 4.35 MPa) and the preset pressure margin value ΔP, and the preset exhaust pressure limit value = Pmax - ΔP, and ΔP can be set according to actual needs; the preset compression ratio λ can be set according to the operating frequency of the compressor. Generally, the specification of the compressor will give a corresponding relationship curve graph between the frequency and the compression ratio range. Different frequency ranges correspond to different compression ratio requirements; further, the preset exhaust pressure limit value Pmax - ΔP and the preset compression ratio λ can be preset and stored in the controller or memory for the controller to retrieve at any time when needed.

[0107] Combined with Figure 7 As shown, it is another working flowchart of the controller of an air conditioner provided by an embodiment of the present invention. On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, when the controller controls the operating frequency of the compressor according to the obtained high-pressure side pressure Pg and the calculated compression ratio φ, it can compare the obtained high-pressure side pressure Pg with the preset exhaust pressure limit value Pmax - ΔP, and compare the calculated compression ratio φ of the compressor with the preset compression ratio λ ( Figure 7 as shown in step S181), to determine whether the high-pressure side pressure Pg satisfies: high-pressure side pressure Pg = preset exhaust pressure limit value Pmax - ΔP, and to determine whether the compression ratio φ of the compressor satisfies: compression ratio φ ≤ preset compression ratio λ ( Figure 7 as shown in step S1821). When it is determined that the high-pressure side pressure Pg satisfies high-pressure side pressure Pg = preset exhaust pressure limit value Pmax - ΔP, and the compression ratio φ of the compressor satisfies compression ratio φ ≤ preset compression ratio λ, the initial operating frequency f0 of the compressor remains unchanged, and the compressor is controlled to continue running at the initial operating frequency f0 ( Figure 7 as shown in step S1822); the continuous running time of the compressor is timed. After the compressor continues to run at the initial operating frequency f0 for the first preset time t1, the outdoor coil temperature Tpo is newly acquired in real time through the second temperature sensor, and the indoor coil temperature Tpi is newly acquired in real time through the third temperature sensor, and the operating frequency of the compressor is controlled based on the newly obtained outdoor coil temperature Tpo and indoor coil temperature Tpi to perform the frequency control of the next cycle ( Figure 7 as shown in step S1823, which is equivalent to returning to Figure 3 as shown in step S17).

[0108] As one optional embodiment, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0109] When the high-pressure side pressure < preset exhaust pressure limit value and the compression ratio ≤ preset compression ratio, increase the operating frequency of the compressor from the initial operating frequency to the first operating frequency, and control the compressor to continue operating at the first operating frequency; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency;

[0110] After the compressor continues to operate at the first operating frequency for a first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0111] Combined Figure 7 As shown, on the basis of the above embodiments, in the specific implementation of the embodiments of the present invention, when the controller controls the operating frequency of the compressor according to the obtained high-pressure side pressure Pg and the calculated compression ratio φ, it can compare the obtained high-pressure side pressure Pg with the preset exhaust pressure limit value Pmax - △P, and compare the calculated compression ratio φ of the compressor with the preset compression ratio λ( Figure 7 shown in step S181), to determine whether the high-pressure side pressure Pg satisfies: high-pressure side pressure Pg < preset exhaust pressure limit value Pmax - △P, and to determine whether the compression ratio φ of the compressor satisfies: compression ratio φ ≤ preset compression ratio λ( Figure 7 shown in step S1831), when it is determined that the high-pressure side pressure Pg satisfies high-pressure side pressure Pg < preset exhaust pressure limit value Pmax - △P and the compression ratio φ of the compressor satisfies compression ratio φ ≤ preset compression ratio λ, it is necessary to adjust the initial operating frequency f0 of the compressor, increase the operating frequency of the compressor from the initial operating frequency f0 to the first operating frequency f1, and control the compressor to continue operating at the first operating frequency f1( Figure 7 shown in step S1832); time the continuous operation time of the compressor (start timing when it is increased from f0 to f1), after the compressor continues to operate at the first operating frequency f1 for a first preset time t1, re-acquire the outdoor coil temperature Tpo in real time through the second temperature sensor, re-acquire the indoor coil temperature Tpi in real time through the third temperature sensor, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature Tpo and indoor coil temperature Tpi to perform frequency control for the next cycle( Figure 7 shown in step S1833, which is equivalent to returning Figure 3 shown in step S17).

[0112] It should be noted that the first operating frequency f1 can be preset and stored in the controller or memory for the convenience of the controller to retrieve it at any time when needed. And the first operating frequency f1 needs to satisfy: the minimum operating frequency fmin ≤ the initial operating frequency f0 < the first operating frequency f1 ≤ the maximum operating frequency fmax. The value of the first operating frequency f1 can be set according to actual needs, and the embodiments of the present invention do not make specific limitations.

[0113] As one optional embodiment, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, which specifically includes:

[0114] When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, reduce the operating frequency of the compressor from the initial operating frequency to the second operating frequency, and control the compressor to continue operating at the second operating frequency; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency;

[0115] After the compressor operates at the second operating frequency for the first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0116] Combined with Figure 7 As shown, on the basis of the above embodiments, in the specific implementation of the embodiments of the present invention, when the controller controls the operating frequency of the compressor according to the obtained high-pressure side pressure Pg and the calculated compression ratio φ, it can compare the obtained high-pressure side pressure Pg with the preset exhaust pressure limit value Pmax - △P, and compare the calculated compression ratio φ of the compressor with the preset compression ratio λ ( Figure 7 step S181 shown), to judge whether the high-pressure side pressure Pg satisfies: the high-pressure side pressure Pg > the preset exhaust pressure limit value Pmax - △P, and to judge whether the compression ratio φ of the compressor satisfies: the compression ratio φ ≤ the preset compression ratio λ ( Figure 7 step S1841 shown). When it is determined that the high-pressure side pressure Pg satisfies the high-pressure side pressure Pg > the preset exhaust pressure limit value Pmax - △P and the compression ratio φ of the compressor satisfies the compression ratio φ ≤ the preset compression ratio λ, it is necessary to adjust the initial operating frequency f0 of the compressor, reduce the operating frequency of the compressor from the initial operating frequency f0 to the second operating frequency f2, and control the compressor to continue operating at the second operating frequency f2 ( Figure 7The steps shown in S1842); time the continuous operation time of the compressor (start timing when it drops from f0 to f2). After the compressor continues to operate at the second operating frequency f2 for the first preset time t1, the outdoor coil temperature Tpo is re-acquired in real time through the second temperature sensor, and the indoor coil temperature Tpi is re-acquired in real time through the third temperature sensor. And based on the re-acquired outdoor coil temperature Tpo and indoor coil temperature Tpi, control the operating frequency of the compressor to perform the frequency control for the next cycle. Figure 7 The steps shown in S1843, which is equivalent to returning Figure 3 The steps shown in S17).

[0117] It should be noted that the second operating frequency f2 can be preset and stored in the controller or memory for the controller to retrieve at any time when needed. And the second operating frequency f2 needs to satisfy: the minimum operating frequency fmin ≤ the second operating frequency f2 < the initial operating frequency f0 ≤ the maximum operating frequency fmax. The value of the second operating frequency f2 can be set according to actual needs, and no specific limitation is made in the embodiments of the present invention.

[0118] It should be noted that the first operating frequency f1 and the second operating frequency f2 need to satisfy: the minimum operating frequency fmin ≤ the second operating frequency f2 < the initial operating frequency f0 < the first operating frequency f1 ≤ the maximum operating frequency fmax.

[0119] As one optional embodiment, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0120] When the high-pressure side pressure = the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, keep the initial operating frequency unchanged, control the compressor to continue to operate at the initial operating frequency, and control the throttling component to increase by a preset number of steps;

[0121] After the compressor continues to operate at the initial operating frequency for the first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0122] Combined with Figure 8As shown, it is another working flowchart of a controller of an air conditioner provided by an embodiment of the present invention. On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, a throttling component is further included in the air conditioner. Correspondingly, when the controller controls the operating frequency of the compressor according to the obtained high-pressure side pressure Pg and the calculated compression ratio φ, it can compare the obtained high-pressure side pressure Pg with a preset exhaust pressure limit value Pmax - △P, and compare the calculated compression ratio φ of the compressor with a preset compression ratio λ( Figure 8 as shown in step S181), to determine whether the high-pressure side pressure Pg satisfies: high-pressure side pressure Pg = preset exhaust pressure limit value Pmax - △P, and to determine whether the compression ratio φ of the compressor satisfies: compression ratio φ > preset compression ratio λ( Figure 8 as shown in step S1851), when it is determined that the high-pressure side pressure Pg satisfies high-pressure side pressure Pg = preset exhaust pressure limit value Pmax - △P, and the compression ratio φ of the compressor satisfies compression ratio φ > preset compression ratio λ, keep the initial operating frequency f0 of the compressor unchanged, control the compressor to continue running at the initial operating frequency f0, and control the throttling component to increase by a preset number of steps( Figure 8 as shown in step S1852); time the continuous running time of the compressor. After the compressor continues to run at the initial operating frequency f0 for a first preset time t1, the outdoor coil temperature Tpo is newly acquired in real time through a second temperature sensor, and the indoor coil temperature Tpi is newly acquired in real time through a third temperature sensor, and the operating frequency of the compressor is controlled based on the newly obtained outdoor coil temperature Tpo and indoor coil temperature Tpi to perform frequency control for the next cycle( Figure 8 as shown in step S1853, which is equivalent to returning Figure 3 as shown in step S17).

[0123] It should be noted that the preferred increase amplitude of the number of steps of the throttling component is 2 steps / S. By increasing the number of steps of the throttling component, the high-pressure side pressure of the air-conditioning system can be reduced, the low-pressure side pressure can be increased, and the compression ratio φ of the compressor can be gradually reduced until the compression ratio φ ≤ preset compression ratio λ, then stop adjusting the throttling component, and after the compression ratio φ of the compressor satisfies compression ratio φ ≤ preset compression ratio λ, the above Figure 7 shown embodiment is used to perform frequency control according to the high-pressure side pressure Pg.

[0124] As one optional embodiment, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0125] When the high-pressure side pressure < preset exhaust pressure limit value and the compression ratio > preset compression ratio, increase the operating frequency of the compressor from the initial operating frequency to the first operating frequency, control the compressor to continue operating at the first operating frequency, and control the throttling component to increase by a preset number of steps; where the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency;

[0126] After the compressor operates at the first operating frequency for a first preset time, re-acquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-acquired outdoor coil temperature and indoor coil temperature.

[0127] Combined with Figure 8 As shown, on the basis of the above embodiments, in the specific implementation of the embodiments of the present invention, the air conditioner further includes a throttling component. Correspondingly, when the controller controls the operating frequency of the compressor according to the obtained high-pressure side pressure Pg and the calculated compression ratio φ, the obtained high-pressure side pressure Pg can be compared with the preset exhaust pressure limit value Pmax - △P, and the calculated compression ratio φ of the compressor can be compared with the preset compression ratio λ( Figure 8 As shown in step S181), to determine whether the high-pressure side pressure Pg satisfies: high-pressure side pressure Pg < preset exhaust pressure limit value Pmax - △P, and to determine whether the compression ratio φ of the compressor satisfies: compression ratio φ > preset compression ratio λ( Figure 8 As shown in step S1861), when it is determined that the high-pressure side pressure Pg satisfies high-pressure side pressure Pg < preset exhaust pressure limit value Pmax - △P and the compression ratio φ of the compressor satisfies compression ratio φ > preset compression ratio λ, it is necessary to adjust the initial operating frequency f0 of the compressor, increase the operating frequency of the compressor from the initial operating frequency f0 to the first operating frequency f1, control the compressor to continue operating at the first operating frequency f1, and control the throttling component to increase by a preset number of steps( Figure 8 As shown in step S1862); time the continuous operation time of the compressor (start timing when it is increased from f0 to f1). After the compressor continues to operate at the first operating frequency f1 for a first preset time t1, re-real-time collect and obtain the outdoor coil temperature Tpo through the second temperature sensor, re-real-time collect and obtain the indoor coil temperature Tpi through the third temperature sensor, and control the operating frequency of the compressor based on the re-obtained outdoor coil temperature Tpo and indoor coil temperature Tpi to perform frequency control for the next cycle( Figure 8 As shown in step S1863, which is equivalent to returning Figure 3 As shown in step S17).

[0128] It should be noted that the first operating frequency f1 can be preset and stored in the controller or memory for the convenience of the controller to retrieve it at any time when needed. And the first operating frequency f1 needs to satisfy: the minimum operating frequency fmin ≤ the initial operating frequency f0 < the first operating frequency f1 ≤ the maximum operating frequency fmax. The value of the first operating frequency f1 can be set according to actual needs, and the embodiments of the present invention do not make specific limitations.

[0129] As one optional embodiment, the controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including:

[0130] When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, reduce the operating frequency of the compressor from the initial operating frequency to the second operating frequency, control the compressor to continue operating at the second operating frequency, and control the throttling component to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency;

[0131] After the compressor operates at the second operating frequency for a first preset time, re-obtain the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-obtained outdoor coil temperature and indoor coil temperature.

[0132] Combined with Figure 8 As shown, on the basis of the above embodiments, in the specific implementation of the embodiments of the present invention, the air conditioner further includes a throttling component. Correspondingly, when the controller controls the operating frequency of the compressor according to the obtained high-pressure side pressure Pg and the calculated compression ratio φ, the obtained high-pressure side pressure Pg can be compared with the preset exhaust pressure limit value Pmax - △P, and the calculated compression ratio φ of the compressor can be compared with the preset compression ratio λ ( Figure 8 the steps shown in S181), to determine whether the high-pressure side pressure Pg satisfies: the high-pressure side pressure Pg > the preset exhaust pressure limit value Pmax - △P, and to determine whether the compression ratio φ of the compressor satisfies: the compression ratio φ > the preset compression ratio λ ( Figure 8 the steps shown in S1871). When it is determined that the high-pressure side pressure Pg satisfies the high-pressure side pressure Pg > the preset exhaust pressure limit value Pmax - △P and the compression ratio φ of the compressor satisfies the compression ratio φ > the preset compression ratio λ, it is necessary to adjust the initial operating frequency f0 of the compressor, reduce the operating frequency of the compressor from the initial operating frequency f0 to the second operating frequency f2, control the compressor to continue operating at the second operating frequency f2, and control the throttling component to increase by a preset number of steps ( Figure 8The steps shown in S1872); time the continuous operation time of the compressor (start timing when it drops from f0 to f2). After the compressor continues to operate at the second operating frequency f2 for the first preset time t1, obtain the outdoor coil temperature Tpo by re-collecting it in real time through the second temperature sensor, obtain the indoor coil temperature Tpi by re-collecting it in real time through the third temperature sensor, and control the operating frequency of the compressor based on the newly obtained outdoor coil temperature Tpo and indoor coil temperature Tpi to perform frequency control for the next cycle. Figure 8 The steps shown in S1873, which is equivalent to returning Figure 3 The steps shown in S17).

[0133] It should be noted that the second operating frequency f2 can be preset and stored in the controller or memory for the controller to retrieve at any time when needed. And the second operating frequency f2 needs to satisfy: the minimum operating frequency fmin ≤ the second operating frequency f2 < the initial operating frequency f0 ≤ the maximum operating frequency fmax. The value of the second operating frequency f2 can be set according to actual needs, and no specific limitation is made in the embodiments of the present invention.

[0134] It should be noted that the first operating frequency f1 and the second operating frequency f2 need to satisfy: the minimum operating frequency fmin ≤ the second operating frequency f2 < the initial operating frequency f0 < the first operating frequency f1 ≤ the maximum operating frequency fmax.

[0135] The embodiments of the present invention also provide a frequency control method for an air conditioner. Refer to Figure 9 As shown, it is a schematic flowchart of a frequency control method for an air conditioner provided by the embodiments of the present invention. The method is applicable to the air conditioner described in any of the above embodiments. The method is executed by the controller, and the method includes steps S21 to S26:

[0136] Step S21, after the air conditioner receives a refrigeration start instruction, obtain the outdoor ambient temperature;

[0137] Step S22, when the outdoor ambient temperature reaches the preset high-temperature ambient temperature limit value, control the air conditioner to execute the high-temperature refrigeration frequency control mode;

[0138] Step S23, in the high-temperature refrigeration frequency control mode, obtain the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset supercooling degree, and control the compressor to operate at the initial operating frequency;

[0139] Step S24, after the compressor operates at the initial operating frequency for the first preset time, obtain the outdoor coil temperature and the indoor coil temperature;

[0140] Step S25: Obtain the high-side pressure of the air conditioner according to the outdoor coil temperature, obtain the low-side pressure of the air conditioner according to the indoor coil temperature, and calculate the compression ratio of the compressor based on the high-side pressure and the low-side pressure;

[0141] Step S26: Control the operating frequency of the compressor according to the high-side pressure and the compression ratio.

[0142] See Figure 10 As shown, it is another flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention. In some embodiments, the obtaining the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset subcooling degree specifically includes:

[0143] Step S231: Calculate the sum value of the outdoor ambient temperature and the preset subcooling degree;

[0144] Step S232: Query the temperature-pressure correspondence table according to the sum value to obtain the saturation pressure value corresponding to the sum value;

[0145] Step S233: Query the pressure-speed correspondence table according to the saturation pressure value to obtain the operating speed corresponding to the saturation pressure value;

[0146] Step S234: Calculate the initial operating frequency of the compressor based on the operating speed.

[0147] In some embodiments, the method further includes:

[0148] Obtain the minimum operating frequency and the maximum operating frequency allowed for the compressor at the corresponding outdoor ambient temperature;

[0149] Then, after obtaining the initial operating frequency of the compressor according to the outdoor ambient temperature and the preset subcooling degree, the method further includes:

[0150] Compare the initial operating frequency with the minimum operating frequency and the maximum operating frequency;

[0151] When the minimum operating frequency ≤ the initial operating frequency ≤ the maximum operating frequency, keep the initial operating frequency unchanged;

[0152] When the initial operating frequency < the minimum operating frequency, configure the minimum operating frequency as the initial operating frequency;

[0153] When the initial operating frequency > the maximum operating frequency, configure the maximum operating frequency as the initial operating frequency.

[0154] See Figure 11As shown, it is another flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention. In some embodiments, controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio specifically includes:

[0155] Step S261: When the high-pressure side pressure = the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, keep the initial operating frequency unchanged and control the compressor to continue operating at the initial operating frequency;

[0156] Step S262: After the compressor continues to operate at the initial operating frequency for a first preset time, re-obtain the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-obtained outdoor coil temperature and indoor coil temperature.

[0157] See Figure 12 As shown, it is another flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention. In some embodiments, controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio specifically includes:

[0158] Step S263: When the high-pressure side pressure < the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, increase the operating frequency of the compressor from the initial operating frequency to the first operating frequency, and control the compressor to continue operating at the first operating frequency; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency;

[0159] Step S264: After the compressor continues to operate at the first operating frequency for a first preset time, re-obtain the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the re-obtained outdoor coil temperature and indoor coil temperature.

[0160] See Figure 13 As shown, it is another flowchart of a frequency control method for an air conditioner provided by an embodiment of the present invention. In some embodiments, controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio specifically includes:

[0161] Step S265: When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio ≤ the preset compression ratio, decrease the operating frequency of the compressor from the initial operating frequency to the second operating frequency, and control the compressor to continue operating at the second operating frequency; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency;

[0162] Step S266: After the compressor operates at the second operating frequency for a first preset time, reacquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the reacquired outdoor coil temperature and indoor coil temperature.

[0163] In some embodiments, the controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio specifically includes:

[0164] When the high-pressure side pressure = the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, keep the initial operating frequency unchanged, control the compressor to continue operating at the initial operating frequency, and control the throttling component to increase by a preset number of steps;

[0165] After the compressor continues to operate at the initial operating frequency for a first preset time, reacquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the reacquired outdoor coil temperature and indoor coil temperature.

[0166] In some embodiments, the controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio specifically includes:

[0167] When the high-pressure side pressure < the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, increase the operating frequency of the compressor from the initial operating frequency to the first operating frequency, control the compressor to continue operating at the first operating frequency, and control the throttling component to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency;

[0168] After the compressor operates at the first operating frequency for a first preset time, reacquire the outdoor coil temperature and the indoor coil temperature, and control the operating frequency of the compressor based on the reacquired outdoor coil temperature and indoor coil temperature.

[0169] In some embodiments, the controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio specifically includes:

[0170] When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, decrease the operating frequency of the compressor from the initial operating frequency to the second operating frequency, control the compressor to continue operating at the second operating frequency, and control the throttling component to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency;

[0171] After the compressor operates at the second operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

[0172] It should be noted that the frequency control method of an air conditioner provided in an embodiment of the present invention can implement all the working processes of the air conditioner described in any of the above embodiments. The specific implementation scheme corresponding to the frequency control method and the achieved technical effects are respectively the same as the specific implementation scheme and the achieved technical effects of the air conditioner described in the above embodiments, and will not be elaborated here.

[0173] In summary, for an air conditioner and a frequency control method of an air conditioner provided in an embodiment of the present invention, the air conditioner includes a refrigerant circuit in which refrigerant circulates sequentially through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; it also includes a first temperature sensor for collecting the outdoor ambient temperature; it also includes a second temperature sensor for collecting the outdoor coil temperature of the outdoor heat exchanger; it also includes a third temperature sensor for collecting the indoor coil temperature of the indoor heat exchanger; it also includes a controller for: after the air conditioner receives a refrigeration start command, acquiring the outdoor ambient temperature; when the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, controlling the air conditioner to execute a high-temperature refrigeration frequency control mode; in the high-temperature refrigeration frequency control mode, acquiring an initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, and controlling the compressor to operate at the initial operating frequency; after the compressor operates at the initial operating frequency for a first preset time, acquiring the outdoor coil temperature and the indoor coil temperature; acquiring the high-pressure side pressure of the air conditioner according to the outdoor coil temperature, acquiring the low-pressure side pressure of the air conditioner according to the indoor coil temperature, and calculating the compression ratio of the compressor according to the high-pressure side pressure and the low-pressure side pressure; controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio. By adopting the high-temperature refrigeration frequency control mode in an embodiment of the present invention, the operating frequency of the compressor can be adjusted in a timely manner according to the changes in pressure and compression ratio, so that both the high-pressure side pressure and the compression ratio of the air-conditioning system fall within the range required by the compressor, which can reduce the mechanical loss of the compressor, thereby improving the reliability of the compressor during refrigeration operation under high-temperature conditions and extending the service life of the compressor.

[0174] The above are only some embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. An air conditioner, characterized in that, The air conditioner includes: A refrigerant circuit in which refrigerant circulates in sequence through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle, where one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; A first temperature sensor for collecting the outdoor ambient temperature; A second temperature sensor for collecting the outdoor coil temperature of the outdoor heat exchanger; A third temperature sensor for collecting the indoor coil temperature of the indoor heat exchanger; A controller for: After the air conditioner receives a refrigeration start instruction, obtaining the outdoor ambient temperature; When the outdoor ambient temperature reaches a preset high-temperature ambient temperature limit value, controlling the air conditioner to execute a high-temperature refrigeration frequency control mode; In the high-temperature refrigeration frequency control mode, obtaining an initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, and controlling the compressor to operate at the initial operating frequency; After the compressor operates at the initial operating frequency for a first preset time, obtaining the outdoor coil temperature and the indoor coil temperature; Obtaining the high-pressure side pressure of the air conditioner according to the outdoor coil temperature, obtaining the low-pressure side pressure of the air conditioner according to the indoor coil temperature, and calculating a compression ratio of the compressor according to the high-pressure side pressure and the low-pressure side pressure; Controlling the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio.

2. The air conditioner according to claim 1, characterized in that, The controller obtains the initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, specifically including: Calculating a sum value of the outdoor ambient temperature and the preset supercooling degree; Querying a temperature-pressure correspondence table according to the sum value to obtain a saturation pressure value corresponding to the sum value; Querying a pressure-speed correspondence table according to the saturation pressure value to obtain an operating speed corresponding to the saturation pressure value; Calculating the initial operating frequency of the compressor according to the operating speed.

3. The air conditioner according to claim 1, characterized in that, The controller is further used for: Obtaining a minimum operating frequency and a maximum operating frequency allowed for the compressor at the corresponding outdoor ambient temperature; Then, after the controller obtains the initial operating frequency of the compressor according to the outdoor ambient temperature and a preset supercooling degree, it is further used for: Comparing the initial operating frequency with the minimum operating frequency and the maximum operating frequency; When the minimum operating frequency ≤ the initial operating frequency ≤ the maximum operating frequency, keeping the initial operating frequency unchanged; When the initial operating frequency < the minimum operating frequency, configuring the minimum operating frequency as the initial operating frequency; When the initial operating frequency > the maximum operating frequency, configuring the maximum operating frequency as the initial operating frequency.

4. The air conditioner according to claim 3, characterized in that, The controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including: When the high-pressure side pressure = a preset exhaust pressure limit value and the compression ratio ≤ a preset compression ratio, keeping the initial operating frequency unchanged and controlling the compressor to continue operating at the initial operating frequency; After the compressor continues to operate at the initial operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

5. The air conditioner according to claim 3, characterized in that, The controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including: When the high-pressure side pressure < preset exhaust pressure limit value and the compression ratio ≤ preset compression ratio, the operating frequency of the compressor is increased from the initial operating frequency to the first operating frequency, and the compressor is controlled to continue operating at the first operating frequency; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency; After the compressor continues to operate at the first operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

6. The air conditioner according to claim 3, characterized in that, The controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including: When the high-pressure side pressure > preset exhaust pressure limit value and the compression ratio ≤ preset compression ratio, the operating frequency of the compressor is decreased from the initial operating frequency to the second operating frequency, and the compressor is controlled to continue operating at the second operating frequency; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency; After the compressor operates at the second operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

7. The air conditioner according to claim 3, wherein The controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including: When the high-pressure side pressure = preset exhaust pressure limit value and the compression ratio > preset compression ratio, keep the initial operating frequency unchanged, control the compressor to continue operating at the initial operating frequency, and control the throttling component to increase by a preset number of steps; After the compressor continues to operate at the initial operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

8. The air conditioner according to claim 3, wherein, The controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, specifically including: When the high-pressure side pressure < preset exhaust pressure limit value and the compression ratio > preset compression ratio, the operating frequency of the compressor is increased from the initial operating frequency to the first operating frequency, control the compressor to continue operating at the first operating frequency, and control the throttling component to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the initial operating frequency < the first operating frequency ≤ the maximum operating frequency; After the compressor operates at the first operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

9. The air conditioner according to claim 3, characterized in that, The controller controls the operating frequency of the compressor according to the high-pressure side pressure and the compression ratio, which specifically includes: When the high-pressure side pressure > the preset exhaust pressure limit value and the compression ratio > the preset compression ratio, the operating frequency of the compressor is reduced from the initial operating frequency to a second operating frequency, the compressor is controlled to continue operating at the second operating frequency, and the throttling component is controlled to increase by a preset number of steps; wherein, the minimum operating frequency ≤ the second operating frequency < the initial operating frequency ≤ the maximum operating frequency; After the compressor operates at the second operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired again, and the operating frequency of the compressor is controlled based on the newly acquired outdoor coil temperature and indoor coil temperature.

10. A frequency control method for an air conditioner, characterized in that, Applicable to the air conditioner according to any one of claims 1 to 9, the method is executed by the controller, and the method includes: After the air conditioner receives a refrigeration start instruction, the outdoor ambient temperature is acquired. When the outdoor ambient temperature reaches the preset high-temperature ambient temperature limit value, the air conditioner is controlled to execute a high-temperature refrigeration frequency control mode. In the high-temperature refrigeration frequency control mode, the initial operating frequency of the compressor is acquired according to the outdoor ambient temperature and the preset supercooling degree, and the compressor is controlled to operate at the initial operating frequency. After the compressor operates at the initial operating frequency for a first preset time, the outdoor coil temperature and the indoor coil temperature are acquired. The high-pressure side pressure of the air conditioner is acquired according to the outdoor coil temperature, the low-pressure side pressure of the air conditioner is acquired according to the indoor coil temperature, and the compression ratio of the compressor is calculated according to the high-pressure side pressure and the low-pressure side pressure. The operating frequency of the compressor is controlled according to the high-pressure side pressure and the compression ratio.

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