Method and device for controlling multi-split air conditioner and multi-split air conditioner

Abstract

The invention relates to the technical field of intelligent household appliances, and discloses a method and device for controlling a multi-split air conditioner and the multi-split air conditioner. The method comprises the steps that under the conditions that the multi-split air conditioner is in a high-outer-environment-temperature heating state and system oil return needs to be conducted, the first high-pressure pressure of the multi-split air conditioner, the initial operation frequency of a compressor and the current outdoor temperature are obtained; according to the current outdoor temperature, the initial frequency increasing speed of the compressor is determined, and after the compressor is controlled to increase the frequency for a first set duration according to the initial frequency increasing speed, the second high-pressure pressure of the multi-split air conditioner is obtained; according to the first high-pressure pressure, the second high-pressure pressure, the initial operation frequency and the first set duration, the first duration for enabling the compressor to reach the safe oil return frequency at the initial frequency increasing speed and the second duration for enabling the multi-split air conditioner to reach the safe high-pressure pressure are calculated; and the frequency increasing rate of the compressor is adjusted according to the first duration and the second duration. The running safety and reliability of the multi-split air conditioner are improved.

Description

Technical Field

[0001] The present application relates to the technical field of intelligent household appliances, for example, to a method and device for controlling a multi-connected air conditioner, and a multi-connected air conditioner. Background Art

[0002] In the related art, when the multi-connected air conditioner needs to perform system oil return, it is necessary to increase the output of the compressor, that is, it is necessary to increase the operating frequency of the compressor to a certain extent to drive the compressor lubricating oil back into the gas-liquid separator.

[0003] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

[0004] When the multi-connected air conditioner is in the high outdoor ambient temperature heating state, the high pressure of the multi-connected air conditioner is higher than that in the conventional low-temperature heating. Therefore, when the multi-connected air conditioner is operating in the high outdoor ambient temperature heating state, if the operating frequency of the compressor is increased for system oil return, the high pressure of the multi-connected air conditioner is extremely likely to exceed the safety high pressure, resulting in potential safety hazards in the operation of the multi-connected air conditioner.

[0005] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a comprehensive review, nor is it intended to identify key / important elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the subsequent detailed description.

[0007] The embodiments of the present disclosure provide a method and device for controlling a multi-connected air conditioner, and a multi-connected air conditioner, which can reduce the risk of potential safety hazards when the multi-connected air conditioner performs system oil return, and improve the safety and reliability of the operation of the multi-connected air conditioner.

[0008] In some embodiments, the method for controlling a multi-connected air conditioner includes: when the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, obtaining the first high pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature; determining the initial frequency increase rate of the compressor according to the current outdoor temperature, and obtaining the second high pressure of the multi-connected air conditioner after controlling the compressor to increase the frequency at the initial frequency increase rate for the first set duration; calculating the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and the second duration for the multi-connected air conditioner to reach the safe high pressure according to the first high pressure, the second high pressure, the initial operating frequency, and the first set duration; adjusting the frequency increase rate of the compressor according to the first duration and the second duration.

[0009] In this embodiment, when the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, first, the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature are obtained, and the compressor is controlled to increase the frequency for the first set duration at the initial frequency increase rate corresponding to the current outdoor temperature. Then, the second high-pressure of the multi-connected air conditioner is obtained, and based on the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration, the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate and the second duration for the multi-connected air conditioner to reach the safe high-pressure are calculated. Finally, by comparing the first duration and the second duration, the increase in the high-pressure during the system oil return process is confirmed, and the frequency increase rate of the compressor is adjusted. In this way, when the multi-connected air conditioner performs system oil return, the situation where the high-pressure exceeds the safe high-pressure can be avoided, the risk of safety hazards is reduced, and the safety and reliability of the operation of the multi-connected air conditioner are improved.

[0010] Optionally, adjusting the frequency increase rate of the compressor according to the first duration and the second duration includes, when the first duration is greater than the second duration, reducing the frequency increase rate of the compressor; when the first duration is equal to the second duration, maintaining or reducing the frequency increase rate of the compressor; when the first duration is less than the second duration, maintaining or increasing the frequency increase rate of the compressor.

[0011] In this embodiment, the frequency increase rate of the compressor is adjusted according to the result of comparing the first duration and the second duration. In this way, when the multi-connected air conditioner performs system oil return, the situation where the high-pressure exceeds the safe high-pressure can be avoided, the risk of safety hazards is reduced, and the safety and reliability of the operation of the multi-connected air conditioner are improved.

[0012] Optionally, when the first duration is greater than the second duration, reducing the frequency increase rate of the compressor includes: determining the third high-pressure of the multi-connected air conditioner after the compressor reaches the safe oil return frequency at the initial frequency increase rate according to the current high-pressure, the first set duration, and the pressure increase rate; calculating the first difference between the third high-pressure and the safe high-pressure; and reducing the frequency increase rate of the compressor according to the first difference.

[0013] In this embodiment, the third high-pressure of the multi-connected air conditioner after the compressor reaches the safe oil return frequency at the initial frequency increase rate can be calculated, and the frequency increase rate of the compressor can be reduced based on the first difference between the third high-pressure and the safe high-pressure. In this way, the specific value of reducing the frequency increase rate of the compressor corresponds to the degree to which the third high-pressure exceeds the safe high-pressure, improving the accuracy of controlling the frequency increase of the compressor.

[0014] Optionally, when the first duration is less than the second duration, maintaining or increasing the frequency increase rate of the compressor includes: calculating the product of the first duration and a set coefficient as the third duration; increasing the frequency increase rate of the compressor when the second duration is greater than or equal to the third duration; and maintaining the frequency increase rate of the compressor when the second duration is less than the third duration.

[0015] In this embodiment, it is determined whether to increase the frequency increase rate of the compressor or maintain the frequency increase rate of the compressor by comparing the magnitudes of the second duration and the third duration (a certain multiple of the first duration). In this way, the risk that the high-pressure pressure of the multi-connected air conditioner exceeds the safe high-pressure pressure during system oil return due to increasing the frequency increase rate of the compressor is reduced.

[0016] Optionally, increasing the frequency increase rate of the compressor includes: calculating a second difference between the second duration and the first duration; and increasing the frequency increase rate of the compressor according to the second difference.

[0017] In this embodiment, the frequency increase rate of the compressor can be increased based on the second difference between the second duration and the first duration. In this way, the specific value of reducing the frequency increase rate of the compressor corresponds to the degree to which the high-pressure pressure of the multi-connected air conditioner is lower than the safe high-pressure pressure, improving the accuracy of controlling the frequency increase of the compressor.

[0018] Optionally, according to the first high-pressure pressure, the second high-pressure pressure, the initial operating frequency, and the first set duration, calculating the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate and the second duration for the multi-connected air conditioner to reach the safe high-pressure pressure includes: calculating a third difference between the safe oil return frequency and the initial operating frequency, and taking the ratio of the third difference to the initial frequency increase rate as the first duration; calculating a fourth difference between the second high-pressure pressure and the first high-pressure pressure, and taking the ratio of the fourth difference to the first set duration as the pressure increase rate; calculating a fifth difference between the safe high-pressure pressure and the first high-pressure pressure, and taking the ratio of the fifth difference to the pressure increase rate as the second duration.

[0019] In this embodiment, the accurate calculation of the first duration and the second duration is achieved.

[0020] Optionally, determining the initial frequency increase rate of the compressor according to the current outdoor temperature includes: determining the initial frequency increase rate corresponding to the current outdoor temperature based on a preset corresponding relationship.

[0021] In this embodiment, a corresponding relationship between the current outdoor temperature and the initial operating frequency of the compressor is preset. In this way, the processor can directly determine the initial frequency increase rate of the compressor by looking up a table without performing relevant calculations, reducing the data processing amount of the processor.

[0022] Optionally, the method for controlling a multi-connected air conditioner further includes: when the first duration is greater than or equal to the second set duration, increasing the opening degree of the electronic expansion valve of the indoor unit in the multi-connected air conditioner that is in the shutdown state.

[0023] In this embodiment, the high-pressure pressure of the multi-connected air conditioner can be relieved by increasing the opening degree of the electronic expansion valve of the indoor unit in the multi-connected air conditioner that is in the shutdown state, so that while increasing the frequency increase rate of the compressor and shortening the time taken for the compressor to rise to the safe oil return frequency, the speed of the high-pressure pressure increase can be reduced.

[0024] In some embodiments, a device for controlling a multi-connected air conditioner includes a processor and a memory storing program instructions, and the processor is configured to execute the method for controlling a multi-connected air conditioner as described above when running the program instructions.

[0025] In some embodiments, a multi-connected air conditioner includes: one or more outdoor units, with a compressor provided inside the outdoor unit; a plurality of indoor units, respectively connected to the indoor units; and the device for controlling a multi-connected air conditioner as described above, with the indoor units and the outdoor units communicatively connected.

[0026] The above general description and the following description are only exemplary and explanatory, and are not used to limit the present application. Description of the Drawings

[0027] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a proportional limitation, and among them:

[0028] Figure 1 is a schematic diagram of a multi-connected air conditioner provided by an embodiment of the present disclosure;

[0029] Figure 2 is a schematic diagram of a method for controlling a multi-connected air conditioner provided by an embodiment of the present disclosure;

[0030] Figure 3 is a schematic diagram of another method for controlling a multi-connected air conditioner provided by an embodiment of the present disclosure;

[0031] Figure 4 is a schematic flowchart of reducing the frequency increase rate of the compressor when the first duration is greater than the second duration provided by an embodiment of the present disclosure;

[0032] Figure 5 is a schematic diagram of another method for controlling a multi-connected air conditioner provided by an embodiment of the present disclosure;

[0033] Figure 6It is a schematic diagram of a device for controlling a multi-connected air conditioner provided by an embodiment of the present disclosure. Detailed implementation manners

[0034] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are only for reference and explanation, and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of explanation, numerous details are provided to give a thorough understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other instances, well-known structures and devices may be shown in a simplified manner to simplify the drawings.

[0035] In the description of the embodiments of the present disclosure, the terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances so as to implement the embodiments of the present disclosure described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0036] Unless otherwise specified, the term "plurality" means two or more.

[0037] In the embodiments of the present disclosure, the character " / " indicates that the objects before and after are in an "or" relationship. For example, A / B means: A or B.

[0038] The term "and / or" is a description of the association relationship of an object, indicating that there can be three relationships. For example, A and / or B means: A or B, or, A and B these three relationships.

[0039] The term "corresponding" may refer to an association relationship or a binding relationship. A corresponding to B means that there is an association relationship or a binding relationship between A and B.

[0040] It should be noted that, without conflict, the embodiments in the embodiments of the present disclosure and the features in the embodiments may be combined with each other.

[0041] The multi-connected air conditioner 100 provided by the embodiments of the present disclosure is as Figure 1 shown. The multi-connected air conditioner 100 includes one or more outdoor units 110 ( Figure 1 the case of one outdoor unit is shown in the figure), a plurality of indoor units 120, and a device 600 for controlling the multi-connected air conditioner.

[0042] Specifically, an outdoor heat exchanger and a compressor are provided in the outdoor unit 110. The plurality of indoor units 120 are respectively connected to the indoor unit 110. The device 600 for controlling the multi-connected air conditioner is communicatively connected to the indoor unit 120 and the outdoor unit 120.

[0043] Optionally, the device for controlling a multi-connected air conditioner includes a processor. When the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, the processor can obtain the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature. The initial frequency increase rate of the compressor can be determined according to the current outdoor temperature. After controlling the compressor to increase its frequency at the initial frequency increase rate for a first set duration, the second high-pressure of the multi-connected air conditioner is obtained. The first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate and the second duration for the multi-connected air conditioner to reach the safe high-pressure can be calculated based on the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration. The increase situation of the high-pressure during the system oil return process can be confirmed by comparing the first duration and the second duration, and the frequency increase rate of the compressor can be adjusted.

[0044] Combined with the above multi-connected air conditioner, an embodiment of the present disclosure provides a method for controlling a multi-connected air conditioner, as Figure 2 shown, the method includes:

[0045] S201. When the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, the processor obtains the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature.

[0046] Specifically, the high outdoor ambient temperature heating state is a working state in which the multi-connected air conditioner heats the room through the indoor unit when the external ambient temperature is relatively high.

[0047] Specifically, when system oil return is required for the multi-connected air conditioner, the operating frequency of the compressor needs to be increased to drive the compressor lubricating oil back to the gas-liquid separator. Since the high-pressure of the multi-connected air conditioner is likely to exceed the safe high-pressure when system oil return is performed in the high outdoor ambient temperature heating state of the multi-connected air conditioner. Therefore, before increasing the operating frequency of the compressor for system oil return, the processor needs to obtain the first high-pressure of the multi-connected air conditioner and the initial operating frequency of the compressor to clarify the current states of the high-pressure side of the multi-connected air conditioner and the compressor.

[0048] Specifically, since the outdoor temperature is a key factor affecting the operating load of the compressor, and the outdoor temperature also affects the physical properties and flow state of the lubricating oil. Therefore, when performing system oil return, the processor needs to obtain the current outdoor temperature to clarify the distribution of the lubricating oil in the multi-connected air conditioner.

[0049] S202. The processor determines the initial frequency increase rate of the compressor according to the current outdoor temperature. After controlling the compressor to increase its frequency at the initial frequency increase rate for a first set duration, the second high-pressure of the multi-connected air conditioner is obtained.

[0050] Specifically, since the outdoor temperature is related to the operating load of the compressor, and the outdoor temperature also affects the physical properties and flow state of the lubricating oil. Therefore, based on the outdoor temperature, the distribution of the lubricating oil in the multi-connected air conditioner can be determined. Under different distribution conditions, different frequency increase rates are used to increase the operating frequency of the compressor, and the degree of increase in the high-pressure pressure of the multi-connected air conditioner is different. Therefore, the processor needs to determine the initial frequency increase rate of the compressor according to the current outdoor temperature, so as to control the compressor to increase its frequency at a frequency increase rate corresponding to the current outdoor temperature, and prevent the initial frequency increase rate of the compressor from being too fast.

[0051] Optionally, determining the initial frequency increase rate of the compressor according to the current outdoor temperature includes: determining the initial frequency increase rate corresponding to the current outdoor temperature based on a preset corresponding relationship.

[0052] Specifically, a corresponding relationship between the current outdoor temperature and the initial operating frequency of the compressor is preset. In this way, the processor can directly determine the initial frequency increase rate of the compressor by looking up the table, without performing relevant calculations, reducing the data processing volume of the processor.

[0053] Exemplarily, the preset corresponding relationship is shown in Table 1 below:

[0054] Table 1

[0055] <![CDATA[Current ambient temperature (T a )]]> Initial frequency up-conversion rate <![CDATA[21 °C < T a ≤ T a1 °C]]> 1Hz / Ns <![CDATA[18 °C < T a ≤ 21 °C]]> 1Hz / (N - 1)s <![CDATA[Ta2℃ < T a ≤ 18℃]]> 1Hz / (N - 2)s

[0056] Wherein, T a1 and T a2 are set according to the geographical location where the multi-connected air conditioner is located, and N is the unit time. It can be seen from Table 1 that the initial frequency increase rate is positively correlated with the current outdoor temperature.

[0057] Specifically, according to the high-pressure pressure of the multi-connected air conditioner before and after the compressor frequency increase, combined with the duration of the frequency increase, the pressure increase rate of the high-pressure pressure of the multi-connected air conditioner when controlling the compressor to increase its frequency can be calculated. According to the pressure increase rate, it can be determined whether the high-pressure pressure of the multi-connected air conditioner will exceed the safety high-pressure pressure during the process of increasing the frequency of the compressor to the safe oil return frequency at the initial frequency increase rate. Therefore, after controlling the compressor to increase its frequency at the initial frequency increase rate for the first set duration, the processor needs to obtain the second high-pressure pressure of the multi-connected air conditioner.

[0058] S203. The processor calculates the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and the second duration for the multi-connected air conditioner to reach the safety high-pressure pressure, according to the first high-pressure pressure, the second high-pressure pressure, the initial operating frequency, and the first set duration.

[0059] Specifically, by determining a first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and a second duration for the multi-connected air conditioner to reach the safe high-pressure pressure at the initial frequency increase rate. By comparing the magnitude relationship between the first duration and the second duration, it can be determined whether the high-pressure pressure of the multi-connected air conditioner will exceed the safe high-pressure pressure during the process of increasing the frequency of the compressor to the safe oil return frequency at the initial frequency increase rate.

[0060] Optionally, according to the first high-pressure pressure, the second high-pressure pressure, the initial operating frequency, and the first set duration, calculate the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and the second duration for the multi-connected air conditioner to reach the safe high-pressure pressure, including: calculating a third difference between the safe oil return frequency and the initial operating frequency, and taking the ratio of the third difference to the initial frequency increase rate as the first duration; calculating a fourth difference between the second high-pressure pressure and the first high-pressure pressure, and taking the ratio of the fourth difference to the first set duration as the pressure increase rate; calculating a fifth difference between the safe high-pressure pressure and the first high-pressure pressure, and taking the ratio of the fifth difference to the pressure increase rate as the second duration.

[0061] Specifically, calculate the first duration according to the following expression:

[0062]

[0063] where t1 is the first duration, F is the safe oil return frequency, f is the initial operating frequency, and V1 is the initial frequency increase rate.

[0064] Specifically, calculate the pressure increase rate according to the following expression:

[0065]

[0066] where V2 is the pressure increase rate, P d1 is the first high-pressure pressure, P d2 is the second high-pressure pressure.

[0067] Specifically, calculate the second duration according to the following expression:

[0068]

[0069] where t2 is the second duration, P is the safe high-pressure pressure, P d1 is the first high-pressure pressure, and V2 is the pressure increase rate.

[0070] S204. The processor adjusts the frequency increase rate of the compressor according to the first duration and the second duration.

[0071] Specifically, by comparing the magnitudes of the first duration and the second duration, it can be determined whether the high-pressure of the multi-connected air conditioner will exceed the safe high-pressure during the process of increasing the operating frequency of the compressor to the safe oil return frequency at the initial frequency increase rate. If it will exceed, the frequency increase rate of the compressor needs to be adjusted downward. If it will not exceed, the frequency increase rate of the compressor can be maintained or appropriately increased.

[0072] In the embodiments of the present disclosure, when the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, first, the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature will be obtained, and the compressor will be controlled to increase its frequency for the first set duration at the initial frequency increase rate corresponding to the current outdoor temperature. Then, the second high-pressure of the multi-connected air conditioner will be obtained, and based on the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration, the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate and the second duration for the multi-connected air conditioner to reach the safe high-pressure will be calculated. Finally, by comparing the first duration and the second duration, the increase in the high-pressure during the system oil return process will be confirmed, and the frequency increase rate of the compressor will be adjusted. In this way, when the multi-connected air conditioner performs system oil return, the situation where the high-pressure exceeds the safe high-pressure can be avoided, the risk of safety hazards is reduced, and the safety and reliability of the operation of the multi-connected air conditioner are improved.

[0073] The embodiments of the present disclosure provide another method for controlling a multi-connected air conditioner, as Figure 3 shown, the method includes:

[0074] S301. When the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, the processor obtains the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature.

[0075] S302. The processor determines the initial frequency increase rate of the compressor according to the current outdoor temperature, and after controlling the compressor to increase its frequency for the first set duration at the initial frequency increase rate, obtains the second high-pressure of the multi-connected air conditioner.

[0076] S303. The processor calculates the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate and the second duration for the multi-connected air conditioner to reach the safe high-pressure based on the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration.

[0077] S304. When the first duration is greater than the second duration, the processor reduces the frequency increase rate of the compressor.

[0078] Specifically, if the first duration is greater than the second duration, it indicates that the compressor is controlled to increase its frequency at the initial frequency increase rate, and the duration for the operating frequency of the compressor to reach the safe oil return frequency is longer than the duration for the multi-connected air conditioner to reach the safe high-pressure. In this case, if the compressor continues to be controlled to increase its frequency at the initial frequency increase rate, the high-pressure of the multi-connected air conditioner will exceed the safe high-pressure during the frequency increase process. Therefore, it is necessary to lower the frequency increase rate of the compressor.

[0079] S305. When the first duration is equal to the second duration, the processor maintains or lowers the frequency increase rate of the compressor.

[0080] Specifically, if the first duration is equal to the second duration, it indicates that the compressor is controlled to increase its frequency at the initial frequency increase rate, and the duration for the operating frequency of the compressor to reach the safe oil return frequency is exactly equal to the duration for the multi-connected air conditioner to reach the safe high-pressure. In this case, if the compressor continues to be controlled to increase its frequency at the initial frequency increase rate, the high-pressure of the multi-connected air conditioner will not exceed the safe high-pressure during the frequency increase process. Therefore, the compressor can be allowed to increase its frequency at the current frequency increase rate.

[0081] It can be understood that during the process of controlling the compressor to increase its frequency, the high-pressure of the multi-connected system may fluctuate. Therefore, when the first duration is equal to the second duration, controlling the compressor to maintain the current frequency increase rate may still result in the high-pressure of the multi-connected air conditioner exceeding the safe high-pressure. Therefore, when the first duration is equal to the second duration, the frequency increase rate of the compressor can also be appropriately reduced to further reduce the risk of the high-pressure of the multi-connected air conditioner exceeding the safe high-pressure.

[0082] S306. When the first duration is less than the second duration, the processor maintains or raises the frequency increase rate of the compressor.

[0083] Specifically, if the first duration is equal to the second duration, it indicates that the compressor is controlled to increase its frequency at the initial frequency increase rate, and the duration for the operating frequency of the compressor to reach the safe oil return frequency is shorter than or equal to the duration for the multi-connected air conditioner to reach the safe high-pressure. In this case, if the compressor continues to be controlled to increase its frequency at the initial frequency increase rate, the high-pressure of the multi-connected air conditioner will not exceed the safe high-pressure during the frequency increase process. Therefore, the compressor can be allowed to increase its frequency at the current frequency increase rate.

[0084] Specifically, when the first duration is less than the second duration, the compressor is controlled to increase its frequency at the current frequency increase rate. Although the high-pressure of the multi-connected air conditioner will not exceed the safe high-pressure, the time for the compressor to reach the safe oil return frequency may be too long. Therefore, when the first duration is less than the second duration, the frequency increase rate of the compressor can be appropriately increased to shorten the time for the compressor to reach the safe oil return frequency.

[0085] In the embodiments of the present disclosure, the frequency increase rate of the compressor is adjusted according to the result of comparing the first duration and the second duration. In this way, when the multi-connected air conditioner performs system oil return, the situation where the high-pressure exceeds the safe high-pressure can be avoided, the risk of potential safety hazards is reduced, and the safety and reliability of the operation of the multi-connected air conditioner are improved.

[0086] In some embodiments, when the first duration is greater than the second duration, the process of reducing the frequency increase rate of the compressor is as Figure 4 shown:

[0087] S401. After the processor determines the third high-pressure of the multi-connected air conditioner after the compressor reaches the safe oil return frequency at the initial frequency increase rate according to the current high-pressure, the first set duration, and the pressure increase rate.

[0088] Specifically, when the first duration is greater than the second duration, although it can be determined that the frequency increase rate of the compressor needs to be reduced, the specific value to be reduced cannot be determined. And according to the third high-pressure of the multi-connected air conditioner after the compressor reaches the safe oil return frequency at the initial frequency increase rate, it can be clear how much the high-pressure of the multi-connected air conditioner exceeds the safe high-pressure after the compressor reaches the safe oil return frequency at the initial frequency increase rate. Based on this degree, the specific value of the frequency increase rate of the compressor that needs to be reduced can be determined. Therefore, the processor needs to calculate the third high-pressure according to the current high-pressure, the first set duration, and the pressure increase rate.

[0089] Specifically, the third high-pressure is calculated according to the following expression:

[0090] P d3 =P d2 +t1×V2;

[0091] Where, P d3 is the third high-pressure, P d2 is the second high-pressure, t1 is the first duration, and V2 is the pressure increase rate.

[0092] S402. The processor calculates the first difference between the third high-pressure and the safe high-pressure.

[0093] Specifically, by calculating the first difference between the third high-pressure and the safety high-pressure, it is possible to clarify the degree to which the high-pressure of the multi-connected air conditioner exceeds the safety high-pressure after the compressor reaches the safe oil return frequency at the initial frequency increase rate. Among them, the larger the first difference, the greater the degree to which the high-pressure of the multi-connected air conditioner exceeds the safety high-pressure.

[0094] S403, the processor reduces the frequency increase rate of the compressor according to the first difference.

[0095] Specifically, since the larger the first difference, the greater the degree to which the high-pressure of the multi-connected air conditioner exceeds the safety high-pressure after the compressor reaches the safe oil return frequency at the initial frequency increase rate. Therefore, the first difference is positively correlated with the specific value of reducing the frequency increase rate of the compressor. Specifically, multiple difference intervals can be set, and the corresponding values of reducing the frequency increase rate are set for each difference interval. After calculating the first difference, determine the target value of reducing the frequency increase rate according to the difference interval where the first difference is located, and then reduce the frequency increase rate of the compressor by the target value.

[0096] In the embodiments of the present disclosure, it is possible to calculate the third high-pressure of the multi-connected air conditioner after the compressor reaches the safe oil return frequency at the initial frequency increase rate, and the frequency increase rate of the compressor can be reduced based on the first difference between the third high-pressure and the safety high-pressure. In this way, the specific value of reducing the frequency increase rate of the compressor corresponds to the degree to which the third high-pressure exceeds the safety high-pressure, improving the accuracy of controlling the frequency increase of the compressor.

[0097] In some embodiments, when the first duration is less than the second duration, maintaining or increasing the frequency increase rate of the compressor includes: calculating the product of the first duration and the set coefficient as the third duration; when the second duration is greater than or equal to the third duration, increasing the frequency increase rate of the compressor; when the second duration is less than the third duration, maintaining the frequency increase rate of the compressor.

[0098] Specifically, the value range of the set coefficient is from 1.5 to 2.

[0099] Specifically, since the first duration is the duration for the compressor to reach the safe oil return frequency when the compressor is controlled to increase the frequency at the initial frequency increase rate, and the second duration is the duration for the multi-connected air conditioner to reach the safety high-pressure when the compressor is controlled to increase the frequency at the initial frequency increase rate. Therefore, by comparing the magnitude relationship between the second duration and a certain multiple of the first duration (i.e., the third duration), it is possible to determine the degree to which the high-pressure of the multi-connected air conditioner is lower than the safety high-pressure after the compressor reaches the safe oil return frequency at the initial frequency increase rate.

[0100] Specifically, if the second duration is greater than or equal to the third duration, it indicates that after the compressor reaches the safe oil return frequency at the initial frequency increase rate, the high-pressure of the multi-connected air conditioner is much lower than the safe high-pressure. Therefore, in this case, the frequency increase rate of the compressor can be increased to shorten the duration of raising the operating frequency of the compressor to the safe oil return frequency, and thus shorten the duration of the multi-connected air conditioner for system oil return.

[0101] Specifically, if the second duration is less than the third duration, it indicates that after the compressor reaches the safe oil return frequency at the initial frequency increase rate, the high-pressure of the multi-connected air conditioner is less lower than the safe high-pressure. In this case, if the frequency increase rate of the compressor is increased, there is a greater risk that the high-pressure of the multi-connected air conditioner exceeds the safe high-pressure during system oil return. Therefore, in this case, the compressor can be maintained at the current frequency increase rate.

[0102] In the embodiments of the present disclosure, by comparing the magnitude relationship between the second duration and the third duration (a certain multiple of the first duration), it is determined whether to increase the frequency increase rate of the compressor or maintain the frequency increase rate of the compressor. In this way, the risk of the high-pressure of the multi-connected air conditioner exceeding the safe high-pressure during system oil return due to increasing the frequency increase rate of the compressor is reduced.

[0103] In some embodiments, increasing the frequency increase rate of the compressor includes: calculating a second difference between the second duration and the first duration; increasing the frequency increase rate of the compressor according to the second difference.

[0104] Specifically, by calculating the second difference between the second duration and the first duration, the degree to which the high-pressure of the multi-connected air conditioner is lower than the safe high-pressure after the compressor reaches the safe oil return frequency at the initial frequency increase rate can be determined. Among them, the greater the second difference, the greater the degree to which the high-pressure of the multi-connected air conditioner is lower than the safe high-pressure.

[0105] Specifically, since the greater the second difference, the greater the degree to which the high-pressure of the multi-connected air conditioner is lower than the safe high-pressure after the compressor reaches the safe oil return frequency at the initial frequency increase rate. Therefore, the second difference is positively correlated with the specific value of increasing the frequency increase rate of the compressor. Specifically, multiple difference intervals can be set, and corresponding values of increasing the frequency increase rate are set for each difference interval. After calculating the second difference, the target value of increasing the frequency increase rate is determined according to the difference interval where the second difference is located, and then the frequency increase rate of the compressor is increased by the target value.

[0106] In the embodiments of the present disclosure, the frequency increase rate of the compressor can be increased based on the second difference between the second duration and the first duration. In this way, the specific value of increasing the frequency increase rate of the compressor corresponds to the degree to which the high-pressure of the multi-connected air conditioner is lower than the safe high-pressure, improving the accuracy of controlling the frequency increase of the compressor.

[0107] Another method for controlling a multi-connected air conditioner provided by an embodiment of the present disclosure is as follows Figure 5 As shown, the method includes:

[0108] S501. When the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, the processor acquires the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature.

[0109] S502. The processor determines the initial frequency increase rate of the compressor according to the current outdoor temperature, and after controlling the compressor to increase the frequency at the initial frequency increase rate for the first set duration, acquires the second high-pressure of the multi-connected air conditioner.

[0110] S503. The processor calculates the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and the second duration for the multi-connected air conditioner to reach the safe high-pressure, according to the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration.

[0111] S504. The processor adjusts the frequency increase rate of the compressor according to the first duration and the second duration.

[0112] S505. When the first duration is greater than or equal to the second set duration, the processor increases the opening degree of the electronic expansion valve of the indoor unit in the shutdown state in the multi-connected air conditioner.

[0113] Optionally, the value range of the second set duration is 120s to 150s.

[0114] Optionally, the proportion of the increase in the opening degree of the electronic expansion valve is 130% of the original opening degree. In the next calculation, if the first duration is still greater than or equal to the second set duration, the opening degree of the electronic expansion valve will continue to be increased by 20%.

[0115] Specifically, if the first duration is greater than or equal to the second set duration, it indicates that the time taken for the operating frequency of the compressor to increase to the safe oil return frequency is too long, and the speed of the high-pressure increase of the multi-connected air conditioner is too fast. Therefore, it is necessary to shorten the duration for the operating frequency of the compressor to increase to the safe oil return frequency, and it is necessary to reduce the speed of the high-pressure increase during the frequency increase process.

[0116] Therefore, in the embodiment of the present disclosure, in the above situation, the opening degree of the electronic expansion valve of the indoor unit in the shutdown state in the multi-connected air conditioner is increased. In this way, the high-pressure of the multi-connected air conditioner can be relieved, so that while increasing the frequency increase rate of the compressor and shortening the duration for the compressor to increase to the safe oil return frequency, the speed of the high-pressure increase can be reduced.

[0117] Combined with Figure 6As shown in the figure, an embodiment of the present disclosure provides a device 600 for controlling a multi-connected air conditioner. The device 600 for controlling a multi-connected air conditioner includes: a processor 601 and a memory 602. Optionally, the device may further include a communication interface 603 and a bus 604. Among them, the processor 601, the communication interface 603, and the memory 602 can communicate with each other through the bus 604. The communication interface 603 can be used for information transmission. The processor 601 can call the logical instructions in the memory 602 to execute the method for controlling the multi-connected air conditioner in the above embodiment.

[0118] In addition, when the logical instructions in the above-mentioned memory 602 are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a computer-readable storage medium.

[0119] The memory 602, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 601 executes functional applications and data processing by running the program instructions / modules stored in the memory 602, that is, implements the method for controlling the multi-connected air conditioner in the above embodiment.

[0120] The memory 602 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 602 may include a high-speed random access memory and may also include a non-volatile memory.

[0121] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, and the computer-executable instructions are set to execute the method for controlling the multi-connected air conditioner above.

[0122] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiment of the present disclosure. The foregoing storage medium may be a non-transitory storage medium, for example: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc, etc., which are various media that can store program codes.

[0123] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure, enabling those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. The embodiments only represent possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terms used in this application are only for describing the embodiments and do not limit the claims. As used in the description of the embodiments and the claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to also include the plural forms. Similarly, as used in this application, the term "and / or" refers to any and all possible combinations of one or more of the associated listed items. Additionally, when used in this application, the term "comprise" and its variants "comprises" and / or "comprising" etc. mean the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups of these. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, or apparatus comprising the element. Herein, what each embodiment focuses on can be the differences from other embodiments, and the same or similar parts among the embodiments can be referred to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method parts disclosed in the embodiments, the relevant parts can refer to the description of the method parts.

[0124] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner can depend on the specific application and design constraints of the technical solution. The skilled person can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the embodiments of the present disclosure. The skilled person can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0125] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units may be only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed couplings or direct couplings or communication connections to each other may be through some interfaces. The indirect couplings or communication connections of the devices or units may be in electrical, mechanical or other forms. The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to implement this embodiment. Additionally, in the embodiments of the present disclosure, the various functional units can be integrated in one processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit.

[0126] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than that disclosed in the description. Sometimes, there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. Each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling a multi-connected air conditioner, characterized in that, Including: When the multi-connected air conditioner is in the high outdoor ambient temperature heating state and system oil return is required, obtain the first high-pressure of the multi-connected air conditioner, the initial operating frequency of the compressor, and the current outdoor temperature; Determine the initial frequency increase rate of the compressor according to the current outdoor temperature, and after controlling the compressor to increase the frequency at the initial frequency increase rate for a first set duration, obtain the second high-pressure of the multi-connected air conditioner; According to the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration, calculate the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and the second duration for the multi-connected air conditioner to reach the safe high-pressure; Adjust the frequency increase rate of the compressor according to the first duration and the second duration.

2. The method according to claim 1, wherein Adjust the frequency increase rate of the compressor according to the first duration and the second duration, including: When the first duration is greater than the second duration, lower the frequency increase rate of the compressor; When the first duration is equal to the second duration, maintain or lower the frequency increase rate of the compressor; When the first duration is less than the second duration, maintain or increase the frequency increase rate of the compressor.

3. The method according to claim 2, wherein When the first duration is greater than the second duration, lower the frequency increase rate of the compressor, including: After determining the third high-pressure of the multi-connected air conditioner when the compressor reaches the safe oil return frequency at the initial frequency increase rate according to the current high-pressure, the first set duration, and the pressure increase rate; Calculate the first difference between the third high-pressure and the safe high-pressure; Lower the frequency increase rate of the compressor according to the first difference.

4. The method according to claim 2, wherein When the first duration is less than the second duration, maintain or increase the frequency increase rate of the compressor, including: Calculate the product of the first duration and the set coefficient as the third duration; When the second duration is greater than or equal to the third duration, increase the frequency increase rate of the compressor; When the second duration is less than the third duration, maintain the frequency increase rate of the compressor.

5. The method according to claim 4, wherein Increase the frequency increase rate of the compressor, including: Calculate the second difference between the second duration and the first duration; Increase the frequency increase rate of the compressor according to the second difference.

6. The method according to any one of claims 1 to 5, characterized in that, According to the first high-pressure, the second high-pressure, the initial operating frequency, and the first set duration, calculate the first duration for the compressor to reach the safe oil return frequency at the initial frequency increase rate, and the second duration for the multi-connected air conditioner to reach the safe high-pressure, including: Calculate the third difference between the safe oil return frequency and the initial operating frequency, and take the ratio of the third difference to the initial frequency increase rate as the first duration; Calculate the fourth difference between the second high-pressure and the first high-pressure, and take the ratio of the fourth difference to the first set duration as the pressure increase rate; Calculate the fifth difference between the safe high-pressure and the first high-pressure, and take the ratio of the fifth difference to the pressure increase rate as the second duration.

7. The method according to any one of claims 1 to 5, characterized in that, Determine the initial frequency increase rate of the compressor according to the current outdoor temperature, including: Based on the preset corresponding relationship, determine the initial frequency increase rate corresponding to the current outdoor temperature.

8. The method according to any one of claims 1 to 5, characterized in that, Also including: When the first duration is greater than or equal to the second set duration, increase the opening degree of the electronic expansion valve of the indoor unit in the shutdown state in the multi-connected air conditioner.

9. A device for controlling a multi-connected air conditioner, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute the method for controlling the multi-connected air conditioner according to any one of claims 1 to 8 when running the program instructions.

10. A multi-connected air conditioner, characterized in that, Comprising: One or more outdoor units, with a compressor disposed therein; Multiple indoor units, respectively connected to the indoor units; The device for controlling a multi-connected air conditioner as described in claim 9, communicatively connected to the indoor units and the outdoor units.

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