Control method and control device for oil return of multi-split air conditioner and multi-split air conditioner
By grouping standby indoor units in a multi-split air conditioner and implementing a differentiated oil return strategy, the problems of condensation risk and insufficient oil return under low load operation are solved, achieving effective oil return and extending compressor life.
Patent Information
- Application Number
- CN202511668714.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-13
- Publication Date
- 2026-01-20
AI Technical Summary
When a multi-split air conditioner is running under low load, the compressor oil return cycle is shortened, which increases the risk of condensation and affects the compressor's lifespan.
The standby indoor units are divided into multiple groups, and different oil return strategies are implemented according to the characteristics of different groups, including normal oil return and limited opening oil return, which are alternated to ensure the oil return effect and reduce the risk of condensation.
By employing a differentiated oil return strategy, localized oil accumulation in the refrigeration unit is avoided, ensuring sufficient oil return, reducing condensation, and extending compressor life.
Smart Images
Figure CN121363786A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of air conditioners, for example to a control method and control device for oil return of a multi-split air conditioner and a multi-split air conditioner. BACKGROUND
[0002] A multi-split air conditioner refers to a refrigeration system composed of one outdoor unit and multiple indoor units in different rooms. Since the indoor units in different rooms may not be turned on at the same time, there is an extreme case that only one indoor unit with the smallest rated cooling capacity is turned on in a refrigeration system, and the remaining indoor units are on standby (this operating condition is referred to as a small load operating condition). In a small load operating condition in summer, the outdoor unit usually operates at a low frequency due to its strong refrigeration capacity. In this operating condition, the oil return period of the compressor is shortened. In a high temperature and high humidity environment, a large amount of condensation is generated in the standby indoor unit due to excessive oil return.
[0003] To solve the above problems, the oil return time can be shortened, the oil return period can be extended, or the opening degree of the electronic expansion valve during oil return can be changed. However, these methods will weaken the oil return effect and affect the service life of the compressor.
[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY
[0005] To have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not a general review, nor is it intended to determine key / important components or delineate the scope of protection of these embodiments, but as a prelude to the detailed description below.
[0006] The embodiments of the present disclosure provide a control method and control device for oil return of a multi-split air conditioner and a multi-split air conditioner to reduce the risk of condensation while ensuring the oil return effect.
[0007] In some embodiments, the method comprises: In a small load operating refrigeration mode of the multi-split air conditioner and in a case where the indoor environment parameters meet the parameter threshold and respond to the oil return instruction, the standby indoor units are divided into N groups according to the information of each standby indoor unit, N > 1; in multiple oil return periods, the standby indoor units in each group are controlled to alternately execute corresponding oil return strategies; wherein the oil return strategies include a normal oil return strategy and a limited opening degree oil return strategy.
[0008] Optionally, the information of the standby indoor unit includes rated cooling capacity and electric heating device information, and the standby indoor units are divided into N groups according to the information of each standby indoor unit, including: In the case that the standby indoor unit is provided with the electric heating device, the standby indoor unit provided with the electric heating device is divided into one group; based on the rated refrigerating capacity of the standby indoor unit, the remaining standby indoor units are divided into two other groups, and the difference of the total rated refrigerating capacity of the two other groups is minimum; or in the case that none of the standby indoor units is provided with the electric heating device, the standby indoor units are divided into two groups according to the rated refrigerating capacity of the standby indoor units, and the difference of the total rated refrigerating capacity of the two groups is minimum. In this way, the standby indoor units can be divided into N groups based on the preset rule, and each group performs a corresponding oil return strategy during oil return. That is, each standby indoor unit can perform a differentiated oil return strategy during oil return, so as to reduce the risk of condensation while ensuring the oil return effect.
[0009] Optionally, in the case that the standby indoor unit is provided with the electric heating device, the control of the standby indoor units in each group to perform the corresponding oil return strategy comprises: controlling the standby indoor unit provided with the electric heating device to start the electric heating device before performing the normal oil return strategy; based on the temperature of the indoor heat exchanger after the normal oil return is completed, the electric heating device is controlled to be turned off; and the standby indoor units in the other two groups are controlled to perform the limited opening oil return strategy; after the standby indoor unit provided with the electric heating device completes the normal oil return strategy, the standby indoor units in the other two groups are controlled to alternately perform the normal oil return strategy and the limited opening oil return strategy; wherein the limited opening oil return strategy comprises limiting the opening degree of the electronic expansion valve of each standby indoor unit to be less than or equal to a preset maximum value. In this way, on the one hand, the standby indoor unit provided with the electric heating device performs the normal oil return strategy, and under the action of the electric heating device, the generation of condensation can be effectively prevented and the oil return amount can be ensured. At the same time, the other two groups perform the limited opening oil return strategy, which can avoid the generation of condensation while reducing the influence on the oil return amount. On the other hand, after the standby indoor unit provided with the electric heating device completes the normal oil return strategy, the other two groups of standby indoor units are controlled to alternately perform the normal oil return strategy and the limited opening oil return strategy. This helps to further improve the oil return amount of the two groups of standby indoor units and reduce the risk of condensation caused by multiple normal oil returns.
[0010] Optionally, the control of the standby indoor units in the other two groups to alternately perform the normal oil return strategy and the limited opening oil return strategy comprises: In a case where the ratio of the total rated refrigerating capacity of each standby indoor unit provided with an electric heating device to the total rated refrigerating capacity of all standby indoor units of the multi-split air conditioner is greater than a threshold ratio, and the number of standby indoor units provided with an electric heating device is greater than the number of remaining standby indoor units, each standby indoor unit not provided with an electric heating device executes the oil return strategy again after a return oil period after each execution of the oil return strategy. In this scenario, the two groups of standby indoor units not provided with an electric heating device can execute the oil return strategy at intervals. That is, after executing the oil return strategy in the current return oil period, the oil return strategy is not executed in the next return oil period, and the oil return strategy is executed again in the return oil period after the next return oil period. In this way, the oil return frequency of the two groups of standby indoor units not provided with an electric heating device can be further reduced, which helps to prevent condensation.
[0011] Optionally, in a case where none of the standby indoor units is provided with an electric heating device, the control of each group of standby indoor units to execute a corresponding oil return strategy comprises: The two groups of standby indoor units are controlled to alternately execute a normal oil return strategy and a limited-opening oil return strategy; wherein the limited-opening oil return strategy comprises limiting the opening degree of each electronic expansion valve to be less than or equal to a preset maximum value. In this way, while ensuring the oil return amount of the two groups of standby indoor units, the condensation risk caused by multiple normal oil returns is reduced.
[0012] Optionally, after the control of each group of standby indoor units to execute a corresponding oil return strategy, the method further comprises: In a case where there is a new standby indoor unit, the new standby indoor unit is divided into a group that has executed the normal oil return strategy, and the remaining standby indoor units are regrouped. Here, the original grouping is broken due to the addition of the new standby indoor unit. Therefore, the grouping is performed again based on the foregoing rules, and then the oil return strategies are alternately executed. In this way, the oil return frequency of the new standby indoor unit is reduced, and the condensation prevention effect is improved.
[0013] Optionally, after the control of each group of standby indoor units to alternately execute a corresponding oil return strategy, the method further comprises: After the end of each return oil period, the fan of each standby indoor unit is controlled to operate at a high speed, and the air guide assembly is opened at a maximum angle; after a first time period or in a case where the temperature difference between the indoor environment and the inlet and outlet pipeline temperatures of the heat exchanger of the standby indoor unit is less than a preset threshold, the fan and the air guide assembly are controlled to be turned off. In this way, the temperature difference between the indoor unit heat exchanger and the indoor environment is reduced, which helps to further reduce condensation.
[0014] Optionally, after the control of each group of standby indoor units to alternately execute a corresponding oil return strategy, the method further comprises: After the third time length, the control ends the operation of the drainage pump in each standby indoor unit of the oil return strategy for a fourth time length. In this way, the condensed water generated during the execution of the oil return strategy is timely drained, and water overflow of the water pan is avoided.
[0015] In some embodiments, the device comprises a processor and a memory storing program instructions, characterized in that the processor is configured to execute the control method for oil return of a multi-split air conditioner as described above when running the program instructions.
[0016] In some embodiments, the multi-split air conditioner comprises an outdoor unit and a plurality of indoor units; and the control device for oil return of a multi-split air conditioner as described above is in communication connection with the plurality of indoor units.
[0017] The control method for oil return of a multi-split air conditioner, the control device and the multi-split air conditioner provided by the embodiments of the present disclosure can achieve the following technical effects: In the embodiments of the present disclosure, the standby indoor units are divided into several groups, and in a plurality of oil return periods, each group of standby indoor units is controlled to alternately execute the corresponding oil return strategy. In this way, it is ensured that the standby indoor units all participate in oil return, avoiding the local accumulation of refrigerant oil, which causes insufficient oil return and affects the service life of the compressor. It can also avoid that all standby indoor units frequently execute the normal oil return strategy, which helps to reduce the generation of condensation.
[0018] The foregoing general description and the following description are only exemplary and explanatory, and are not intended to limit the present application. BRIEF DESCRIPTION OF DRAWINGS
[0019] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute a limitation on the embodiments, and elements with the same reference numerals in the drawings are shown as similar elements, the drawings do not constitute a proportional limitation, and wherein: Figure 1 is a schematic diagram of one control method for oil return of a multi-split air conditioner provided by the embodiments of the present disclosure; Figure 2 is a schematic diagram of another control method for oil return of a multi-split air conditioner provided by the embodiments of the present disclosure; Figure 3 is a schematic diagram of another control method for oil return of a multi-split air conditioner provided by the embodiments of the present disclosure; Figure 4 is a schematic diagram of another control method for oil return of a multi-split air conditioner provided by the embodiments of the present disclosure; Figure 5 is a schematic diagram of another control method for oil return of a multi-split air conditioner provided by the embodiments of the present disclosure; Figure 6is a schematic view of a control device for oil return of a multi-split air conditioner provided by an embodiment of the present disclosure. Figure 7 is a schematic view of a multi-split air conditioner provided by an embodiment of the present disclosure. DETAILED DESCRIPTION
[0020] In order to enable a more detailed understanding of the features and technical content of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, which are only used for reference and do not limit the embodiments of the present disclosure. In the following technical description, in order to facilitate explanation, a plurality of details are provided to provide a full understanding of the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be simplified to facilitate the drawings.
[0021] The terms "first", "second", and the like in the specification and claims of the embodiments of the present disclosure and the above-described drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.
[0022] Unless otherwise specified, the term "a plurality of" means two or more.
[0023] In the embodiments of the present disclosure, the character " / " represents an "or" relationship between the objects before and after it. For example, A / B represents: A or B.
[0024] The term "and / or" is a description of the association relationship between objects, which means that there can be three relationships. For example, A and / or B means: A or B, or, A and B, the three relationships.
[0025] The term "corresponding" can refer to an association relationship or a binding relationship. A and B correspond to each other means that A and B have an association relationship or a binding relationship.
[0026] In combination Figure 1 As shown, the embodiments of the present disclosure provide a control method for oil return of a multi-split air conditioner, comprising: S101, in the case that the multi-split air conditioner is in a small load operation refrigeration mode and the indoor environment parameters meet the parameter threshold, and the oil return instruction is responded, the multi-split air conditioner divides standby indoor units into N groups according to the information of each standby indoor unit, N>1.
[0027] S102, in a plurality of oil return periods, the multi-split air conditioner controls the standby indoor units of each group to alternately execute corresponding oil return strategies; wherein the oil return strategies include a normal oil return strategy and a limited opening oil return strategy.
[0028] Here, the small load operation refers to that the multi-split air conditioner only starts the indoor unit with the smallest rated cooling capacity. The oil return period refers to the time interval between two adjacent oil return instructions, for example, the time length from the execution of the current oil return instruction to the execution of the next oil return instruction. The parameter threshold is used to determine whether the indoor environment is a high temperature and high humidity environment. When the indoor environment parameters meet the parameter threshold, it indicates that the indoor environment is a high temperature and high humidity environment. Alternatively, the parameter threshold includes a dry-bulb temperature threshold and a wet-bulb temperature threshold (the relative humidity can be calculated based on the two). For example, the dry-bulb temperature threshold is 30°C, and the wet-bulb temperature threshold is 28.6°C. Alternatively, or optionally, the parameter threshold includes a temperature threshold and a relative humidity threshold. For example, the temperature threshold is 30°C, and the relative humidity threshold is 90%.
[0029] When the multi-split air conditioner is in a small load operation cooling mode and the indoor environment is in a high temperature and high humidity state, the multi-split air conditioner frequently executes the oil return instruction, which is easy to cause condensation in the standby indoor unit. In order to reduce condensation and ensure the oil return effect, the present embodiment divides the standby indoor unit into several groups, and each group of standby indoor units executes a corresponding oil return strategy. That is, in the same oil return period, the multiple groups of standby indoor units respectively execute the normal oil return strategy and the limited opening oil return strategy. And in different oil return periods, the multiple groups of standby indoor units alternately execute the normal oil return strategy and the limited opening oil return strategy. For example, the standby indoor unit includes two groups, which are the first group and the second group. In the first oil return period, the first group executes the normal oil return strategy, and the second group executes the limited opening oil return strategy. In the second oil return period, the first group executes the limited opening oil return strategy, and the second group executes the normal oil return strategy; and so on. In this way, it is avoided that all standby indoor units frequently execute the normal oil return strategy, and it is ensured that the standby indoor units all participate in the oil return, avoiding the local accumulation of refrigerant oil, and helping to reduce the generation of condensation. At the same time, part of the indoor units execute the normal oil return strategy in each oil return period, ensuring the oil return amount to avoid the insufficient oil return affecting the service life of the compressor.
[0030] Among them, the normal oil return strategy refers to that the indoor unit executes the oil return based on the oil return program set by the multi-split air conditioner (without limiting the maximum opening of the electronic expansion valve). The limited opening oil return strategy refers to limiting the opening of the electronic expansion valve of the indoor unit, that is, the opening of the electronic expansion valve is not greater than a preset maximum value. Alternatively, the multiple oil return periods can be 2-4 oil return periods. The number of oil return periods can be determined based on the indoor environment parameters. The more conducive to the generation of condensation, the fewer the number of oil return periods. Alternatively, the number of oil return periods can be determined based on the number of groups. For example, the standby indoor unit is divided into 3 groups, and the oil return period is 3, then every 3 oil return periods, the standby indoor units of each group are controlled to alternately execute the corresponding oil return strategy.
[0031] In addition, regarding the grouping of the standby indoor units, the standby indoor units can be evenly distributed based on the capacity, i.e., the rated refrigerating capacity, of each standby indoor unit, so that the total capacity of the two groups of standby indoor units after distribution is substantially consistent. Further, the standby indoor units can also be divided into multiple groups based on the capacity and the electric heating device of each standby indoor unit. The standby indoor units provided with the electric heating device form one group, and the other standby indoor units can be divided into two groups or three groups, etc. During oil return, the electric heating device is controlled to be turned on, which can improve the anti-condensation effect.
[0032] By using the control method for oil return of the multi-split air conditioner provided in the embodiments of the present disclosure, the standby indoor units are divided into several groups, and each group of standby indoor units is controlled to alternately execute the corresponding oil return strategy in multiple oil return periods. In this way, it is ensured that the standby indoor units all participate in oil return, avoiding insufficient oil return caused by local accumulation of refrigerant oil and affecting the service life of the compressor. It can also avoid that all standby indoor units frequently execute the normal oil return strategy, which helps to reduce the generation of condensation.
[0033] Optionally, the information of the standby indoor unit includes the rated refrigerating capacity and the electric heating device, and in step S101, the multi-split air conditioner divides the standby indoor units into N groups according to the information of each standby indoor unit, including: In the case where the standby indoor unit is provided with the electric heating device, the multi-split air conditioner divides the standby indoor units provided with the electric heating device into one group, and divides the remaining standby indoor units into another two groups based on the rated refrigerating capacity of the standby indoor units, and the difference between the total rated refrigerating capacities of the other two groups is minimum. Alternatively, In the case where none of the standby indoor units is provided with the electric heating device, the multi-split air conditioner divides the standby indoor units into two groups according to the rated refrigerating capacity of the standby indoor units, and the difference between the total rated refrigerating capacities of the two groups is minimum.
[0034] Here, the information of the standby indoor unit includes the rated refrigerating capacity and the electric heating device information (i.e., whether the standby indoor unit is provided with the electric heating device). It can be understood that each standby indoor unit must have the rated refrigerating capacity, but it is not necessarily provided with the electric heating device. Therefore, based on the information of the standby indoor unit, there are two grouping bases. One is based on the rated refrigerating capacity of the standby indoor unit, and the other is based on the rated refrigerating capacity and the electric heating device of the standby indoor unit.
[0035] In detail, when grouping according to the rated refrigerating capacity of the standby indoor unit, the standby indoor units are divided into two groups, and the difference between the total rated refrigerating capacities of the two groups is minimum (i.e., the rated refrigerating capacities of the two groups are evenly distributed, so that the total rated refrigerating capacities of the two groups are substantially the same). When grouping according to the rated refrigerating capacity and the electric heating device of the standby indoor unit, the standby indoor units provided with the electric heating device form one group. Then, the other standby indoor units are divided into two groups based on the rated refrigerating capacity. And the total rated refrigerating capacities of the two groups also follow the principle of substantially the same distribution.
[0036] Further, when grouping standby indoor units, each standby indoor unit can be distinguished based on the address of each standby indoor unit. For example, the standby indoor units include 9 units, and the 9 units are respectively numbered 1 to 9 according to the addresses. The rated cooling capacity of each of the 1st to 5th units is 2500W, and the rated cooling capacity of each of the 6th to 9th units is 5000W. Grouping the standby indoor units according to the rated cooling capacity of the standby indoor units, the 1st to 3rd, 6th, and 7th units can be the first group, and the 4th, 5th, 8th, and 9th units can be the second group (not limited to this grouping, other combinations can be made based on the average allocation principle). In another example, on the basis of the previous example, the 1st and 2nd units are further provided with electric heating devices. Then, the 1st and 2nd units are the first group, the 3rd, 4th, 6th, and 7th units can be the second group, and the 5th, 8th, and 9th units can be the third group.
[0037] In this way, the standby indoor units can be divided into N groups based on the preset rule, and each group performs a corresponding oil return strategy during oil return. That is, during oil return, each standby indoor unit can perform a differentiated oil return strategy to reduce the risk of condensation while ensuring the effect of oil return.
[0038] In combination with Figure 2 As shown in the figure, the embodiment of the present disclosure provides another control method for oil return of a multi-split air conditioner, which comprises: S101, in the case that the multi-split air conditioner is in a small load operation refrigeration mode and the indoor environmental parameters meet the parameter threshold and the oil return instruction is responded, the multi-split air conditioner divides standby indoor units into N groups according to the information of each standby indoor unit, N>1.
[0039] S121, in the case that the standby indoor units are provided with electric heating devices, during multiple oil return periods, the multi-split air conditioner controls the standby indoor units provided with electric heating devices to start the electric heating devices before performing the normal oil return strategy; controls the electric heating devices to be turned off based on the temperature of the indoor heat exchanger after the normal oil return is completed; and controls the standby indoor units of the other two groups to perform the limited opening oil return strategy.
[0040] S122, after the group provided with the electric heating devices ends the normal oil return strategy, the multi-split air conditioner controls the standby indoor units of the other two groups to alternately perform the normal oil return strategy and the limited opening oil return strategy.
[0041] The limited opening oil return strategy comprises limiting the opening degree of each standby indoor unit to be less than or equal to a preset maximum value.
[0042] The embodiments of the present disclosure mainly aim at the oil return control of standby indoor units grouped based on rated refrigerating capacity and electric heating device. In multiple oil return periods, N groups of standby indoor units are controlled to execute normal oil return strategy and limited opening oil return strategy respectively. Among them, the standby indoor unit provided with an electric heating device only executes the normal oil return strategy. In detail, when the standby indoor unit provided with an electric heating device executes the normal oil return strategy, other standby indoor units execute the limited opening oil return strategy. Before the standby indoor unit provided with an electric heating device executes the normal oil return strategy (i.e. before a preset time period, such as 10 seconds), the electric heating device is controlled to be turned on. After the oil return is completed, the electric heating device is controlled to be turned off based on the temperature of the indoor heat exchanger. Among them, the electric heating device is controlled to be turned off based on the temperature of the indoor heat exchanger, which can be that the electric heating device is controlled to be turned off after the temperature of the indoor heat exchanger reaches a preset condition. The preset condition is set based on the critical value of whether the indoor heat exchanger is prone to produce condensation, so as to ensure that the temperature of the indoor heat exchanger is not too low to reduce the possibility of producing condensation after the electric heating device is turned off.
[0043] After the standby indoor unit provided with an electric heating device ends the normal oil return strategy, the other two groups of standby indoor units are controlled to alternately execute the normal oil return strategy and the limited opening oil return strategy (at this time, the standby indoor unit provided with an electric heating device does not execute the limited opening oil return strategy). In this way, steps S121 and S122 are periodically executed. On the one hand, the standby indoor unit provided with an electric heating device executes the normal oil return strategy, which can effectively prevent the generation of condensation and ensure the oil return amount under the action of the electric heating device. At the same time, the other two groups execute the limited opening oil return strategy, which also avoids the generation of condensation while reducing the influence on the oil return amount. On the other hand, after the standby indoor unit provided with an electric heating device ends the normal oil return strategy, the other two groups of standby indoor units are controlled to alternately execute the normal oil return strategy and the limited opening oil return strategy. This helps to further improve the oil return amount of the two groups of standby indoor units and reduce the risk of condensation caused by multiple normal oil returns.
[0044] In addition, the limited opening oil return strategy includes limiting the opening degree of the electronic expansion valve of each standby indoor unit to be less than or equal to a preset maximum value. The preset maximum value is slightly greater than the minimum conduction opening degree of the electronic expansion valve. At the minimum conduction opening degree, the refrigerant can keep flowing in the refrigeration cycle circuit. For example, if the minimum conduction opening degree is 40 pls, the preset maximum value is in the range of 50 pls to 60 pls. In this way, the refrigerant of the standby indoor unit flows to bring the compressor oil back to the compressor. At the same time, the flow amount of the refrigerant is limited to reduce the possibility of condensation of the indoor heat exchanger.
[0045] Optionally, the multi-split air conditioner controls the electric heating device to be turned off based on the temperature of the indoor heat exchanger, including: when the indoor environment temperature of the heat exchanger of the standby indoor unit and the difference between the inlet pipeline temperature and the outlet pipeline temperature are all less than a preset threshold, the multi-split air conditioner controls the electric heating device to be turned off.
[0046] Here, when the difference between the indoor environment temperature of the heat exchanger of the standby indoor unit and the inlet pipeline temperature is less than the preset threshold value, and the difference between the indoor environment temperature and the outlet pipeline temperature is also less than the preset threshold value, the electric heating device is controlled to be closed. The indoor environment of the standby indoor unit satisfying the above conditions has a small difference from the indoor environment, and is not easy to produce condensation. Therefore, the electric heating device can be controlled to be closed. For example, the preset threshold value is 10℃. In this way, the anti-condensation effect can be improved.
[0047] Optionally, after the normal oil return strategy of the group provided with the electric heating device is completed, the multi-split air conditioner controls the standby indoor units of the other two groups to alternately execute the normal oil return strategy and the limited opening oil return strategy, including: When the ratio of the total rated refrigerating capacity of each standby indoor unit provided with the electric heating device to the total rated refrigerating capacity of all indoor units of the multi-split air conditioner is greater than the ratio threshold value, and the number of standby indoor units provided with the electric heating device is greater than the number of remaining standby indoor units, the multi-split air conditioner controls two groups of standby indoor units not provided with the electric heating device to execute the oil return strategy again after each execution of the oil return strategy with an interval of an oil return period.
[0048] Here, the ratio threshold value can be 70% to 80%. When the ratio of the total rated refrigerating capacity of each standby indoor unit provided with the electric heating device to the total rated refrigerating capacity of all standby indoor units of the multi-split air conditioner is greater than the ratio threshold value, it indicates that the standby indoor unit provided with the electric heating device has relatively strong capacity and accumulates relatively more oil. Further, when the number of standby indoor units provided with the electric heating device is greater than the number of remaining standby indoor units, the standby indoor unit provided with the electric heating device can ensure the oil return amount when executing the normal oil return strategy, meeting the demand of the compressor. Therefore, in this scenario, the two groups of standby indoor units not provided with the electric heating device can execute the oil return strategy with an interval. That is, after executing the oil return strategy in the current oil return period, the oil return strategy is not executed in the next oil return period, and the oil return strategy is executed again in the next oil return period. In this way, the oil return frequency of the two groups of standby indoor units not provided with the electric heating device can be further reduced, which helps to prevent condensation.
[0049] In addition, it should be noted that if each standby indoor unit provided with the electric heating device does not satisfy the above conditions, the two groups of standby indoor units not provided with the electric heating device are controlled to alternately execute the normal oil return strategy and the limited opening oil return strategy. In this way, the oil return amount is ensured.
[0050] In combination with Figure 3 As shown in the figure, the embodiment of the present disclosure provides another control method for oil return of a multi-split air conditioner, including: S101, in the case that the multi-split air conditioner is in a small load operation refrigeration mode and indoor environmental parameters meet parameter thresholds and a response oil return instruction, the multi-split air conditioner divides standby indoor units into N groups according to information of each standby indoor unit, and N > 1.
[0051] S123, in the case that none of the standby indoor units is provided with an electric heating device, the multi-split air conditioner controls standby indoor units in two groups to alternately execute a normal oil return strategy and a limited opening oil return strategy in multiple oil return periods. The limited opening oil return strategy includes limiting the opening of the electronic expansion valve of each standby indoor unit to be less than or equal to a preset maximum value.
[0052] The embodiments of the present disclosure mainly describe the oil return control of standby indoor units grouped based on rated refrigerating capacity. In the case that none of the standby indoor units is provided with an electric heating device, the standby indoor units are divided into two groups based on rated refrigerating capacity. Then, in multiple oil return periods, the standby indoor units in the two groups alternately execute a normal oil return strategy and a limited opening oil return strategy. Here, the multiple oil return periods can be two oil return periods. In this way, the amount of oil return of the two groups of standby indoor units is ensured, and the risk of condensation caused by multiple normal oil returns is reduced.
[0053] Then, optionally, after the end of each oil return period, the fan and the air guide assembly of each standby indoor unit are controlled to operate to timely discharge the cold in each standby indoor unit. Thus, the temperature difference between the inner cavity of the standby indoor unit and the environment is avoided, and condensation is avoided. The fan and the air guide assembly operating include that the fan operates at a high speed, and the air guide assembly is turned on (such as the air deflector is opened and / or the swing leaf is opened). In this way, the cold is discharged in time, and condensation water is avoided.
[0054] In combination with Figure 4 As shown in the figure, the embodiments of the present disclosure provide a control method for oil return of a multi-split air conditioner, which includes: S101, in the case that the multi-split air conditioner is in a small load operation refrigeration mode and indoor environmental parameters meet parameter thresholds and a response oil return instruction, the multi-split air conditioner divides standby indoor units into N groups according to information of each standby indoor unit, and N > 1.
[0055] S102, in multiple oil return periods, the multi-split air conditioner controls standby indoor units in each group to alternately execute corresponding oil return strategies; and the oil return strategies include a normal oil return strategy and a limited opening oil return strategy.
[0056] S203, in the case that there is a new standby indoor unit, the multi-split air conditioner divides the new standby indoor unit to a group that has executed the normal oil return strategy, and re-groups the remaining standby indoor units. Then, step S102 is executed.
[0057] Here, in the process of performing oil return, the standby indoor unit can change. For example, the indoor unit that is turned off is started to run, and a new indoor unit is started to run. In this case, because the indoor unit that is turned off (i.e., the new standby indoor unit) was in a normal running state or in a normal oil return state before, the new standby indoor unit can be divided into a group that has already performed a normal oil return strategy. At the same time, because of the addition of the new standby indoor unit, the original group is broken. Therefore, the grouping is performed again based on the foregoing rules. Then, oil return is performed again. In this way, the number of oil returns of the new standby indoor unit is reduced, and the anti-condensation effect is improved.
[0058] In combination Figure 5 As shown in the drawings, the embodiments of the present disclosure provide a control method for oil return of a multi-split air conditioner, comprising: S101, in the case that the multi-split air conditioner is in a small load operation refrigeration mode and an indoor environment parameter meets a parameter threshold value, and an oil return instruction is responded to, the multi-split air conditioner divides standby indoor units into N groups according to information of each standby indoor unit, N>1.
[0059] S102, in a plurality of oil return periods, the multi-split air conditioner controls the standby indoor units of each group to alternately perform corresponding oil return strategies; wherein the oil return strategies include a normal oil return strategy and a limited opening oil return strategy.
[0060] S304, after each oil return period ends, the multi-split air conditioner controls the fan of each standby indoor unit to run at a high gear speed, and controls the air guide assembly to open at a maximum angle.
[0061] S305, after a first time length or in the case that the heat exchanger temperature of each standby indoor unit meets a preset condition, the multi-split air conditioner controls the fan and the air guide assembly to be turned off.
[0062] The preset condition includes that the indoor environment temperature and the difference between the inlet pipeline temperature and the outlet pipeline temperature of the heat exchanger of the standby indoor unit are each less than a preset threshold value.
[0063] Here, after each oil return period ends, the fan and air guide assembly of each standby indoor unit are controlled to operate. This reduces the temperature difference between the heat exchanger of the standby indoor unit and the indoor environment, which helps to further reduce condensation. In detail, after each oil return period ends, the fan of each standby indoor unit is controlled to operate at the highest speed, and the air guide assembly is controlled to open to the maximum angle. Within a first time length (e.g., 5 seconds), the heat exchanger temperature of each standby indoor unit is detected in real time to determine whether it meets a preset condition. If it does, the corresponding fan and air guide assembly are turned off. If it does not, the fan and air guide assembly are turned off after the first time length. The preset condition includes that the difference between the indoor environment temperature and the inlet pipeline temperature of the heat exchanger is less than a preset threshold, and the difference between the indoor environment temperature and the outlet pipeline temperature of the heat exchanger is also less than the preset threshold (for example, the preset threshold can be 10°C). In this way, the anti-condensation effect is improved.
[0064] Optionally, after the fan and air guide assembly are controlled to be turned off in step S305, the multi-split air conditioner further includes: After the second time length, the multi-split air conditioner determines again whether the heat exchanger temperature of each standby indoor unit meets the preset condition.
[0065] If it does not, the multi-split air conditioner controls the fan of each standby indoor unit to operate at a high speed, and the air guide assembly to open to the maximum angle. The second time length is greater than the first time length.
[0066] Here, after the fan and air guide assembly are turned off after the first time length, the temperature of the heat exchanger of the standby indoor unit may still not meet the preset condition. Therefore, after the second time length (e.g., 5 minutes), it is determined again whether the heat exchanger temperature meets the preset condition. If it does not, the corresponding standby indoor unit is controlled to perform cold discharge again. That is, the fan and air guide assembly of the corresponding indoor unit are turned on again to reduce the temperature difference between the indoor unit cavity and the indoor environment as much as possible.
[0067] Optionally, after the multi-split air conditioner controls each group of standby indoor units to alternately execute the corresponding oil return strategy in step S102, the multi-split air conditioner further includes: After the third time length, the multi-split air conditioner controls the drainage pump of each standby indoor unit that ends the oil return strategy to operate for a fourth time length.
[0068] Here, after each group executes the oil return strategy for the third time length, the drainage pump is controlled to operate for the fourth time length. Thus, the condensate generated during the execution of the oil return strategy is promptly drained, avoiding water overflow in the water pan. Optionally, the drainage pump can be controlled to operate for the fourth time length after each group executes the normal oil return strategy for the third time length. This is because, in the normal oil return strategy, the refrigerant flow is large, and the evaporation temperature and pressure drop significantly, which is more likely to cause condensation. In addition, the third time length can be about 1 minute, and the fourth time length can be about 10 seconds.
[0069] In combination Figure 6 As shown in the above, the embodiment of the present disclosure provides a control device 100 for oil return of a multi-split air conditioner, comprising a processor 101 and a memory 102. Optionally, the device can further comprise a communication interface 103 and a bus 104. Wherein the processor 101, the communication interface 103 and the memory 102 can complete the communication among each other through the bus 104. The communication interface 103 can be used for information transmission. The processor 101 can call the logic instructions in the memory 102 to execute the control method for oil return of a multi-split air conditioner in the above embodiment.
[0070] In addition, the logic instructions in the memory 102 described above can be realized in the form of a software function unit and sold or used as an independent product, which can be stored in a computer readable storage medium.
[0071] The memory 102 as a computer readable storage medium can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 101 executes the function application and data processing by running the program instructions / modules stored in the memory 102, that is, realizes the control method for oil return of a multi-split air conditioner in the above embodiment.
[0072] The memory 102 can include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required by a function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 102 can include a high-speed random access memory, and can also include a non-volatile memory.
[0073] In combination Figure 7 As shown in the above, the embodiment of the present disclosure provides a multi-split air conditioner 200, comprising an outdoor unit 201 and a plurality of indoor units 202, and the above-mentioned control device 100 for oil return of a multi-split air conditioner. The control device 100 for oil return of a multi-split air conditioner is in communication connection with the plurality of indoor units. The installation relationship described herein is not limited to being placed inside the multi-split air conditioner body, but also includes installation connection with other components of the multi-split air conditioner 100, including but not limited to physical connection, electrical connection or signal transmission connection, etc. Those skilled in the art can understand that the control device 100 for oil return of a multi-split air conditioner can be adapted to a feasible multi-split air conditioner body, and thus realize other feasible embodiments.
[0074] The embodiment of the present disclosure provides a computer readable storage medium, which stores computer executable instructions, and the computer executable instructions are set to execute the above-mentioned control method for oil return of a multi-split air conditioner.
[0075] The technical solutions of the embodiments 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 can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method disclosed in the embodiments of the present disclosure. The aforementioned storage medium can be a non-transitory storage medium, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.
[0076] The above description and drawings sufficiently illustrate the embodiments of the present disclosure to enable one skilled in the art to practice them. Other embodiments can include structural, logical, electrical, process, and other changes. The embodiments represent only a few of the possible variations. Individual components and functions are optional unless explicitly required, and the order of operations can be changed. Parts and features of some embodiments can be included in or replace parts and features of other embodiments. Also, the words used in this application are only used to describe the embodiments and not to limit the claims. As used in the description of the embodiments and the claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Similarly, as used in this application, the term "and / or" refers to any and all possible combinations of one or more associated listed items. In addition, when used in this application, the term "comprise" and its variants "comprises" and / or comprises" and the like mean the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, or device that includes the stated element. In this document, each embodiment focuses on the differences from other embodiments, and the same or similar parts between various embodiments can be referred to each other. For the method, product, etc. disclosed in the embodiments, if it corresponds to the method part disclosed in the embodiments, the relevant part can be referred to the description of the method part.
[0077] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods for each specific application to realize the described functions, but such implementation should not be considered beyond 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 above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.
[0078] 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 above-described device embodiments are only schematic, for example, the division of the units can only be a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms. The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to implement the embodiments. In addition, each functional unit in the embodiments of the present disclosure can be integrated in one processing unit, or each unit can be a physically independent unit, or two or more units can be integrated in one unit.
[0079] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.
Claims
1. A control method for oil return of a multi-split air conditioner, characterized in that, The application relates to a method for controlling oil return of a multi-connected air conditioner. In the case that the multi-connected air conditioner is in a small load refrigeration mode and indoor environmental parameters meet parameter threshold values and an oil return instruction is responded to, standby indoor units are divided into N groups according to information of the standby indoor units, and N>1. In a plurality of oil return periods, the standby indoor units in each group are controlled to alternately execute corresponding oil return strategies; wherein the oil return strategies include a normal oil return strategy and a limited opening oil return strategy.
2. The method of claim 1, wherein, The information of the standby indoor units includes rated refrigerating capacity and electric heating device information, and the standby indoor units are divided into N groups according to the information of the standby indoor units, including: In the case that the standby indoor units are provided with electric heating devices, the standby indoor units provided with the electric heating devices are divided into one group; and the remaining standby indoor units are divided into another two groups based on rated refrigerating capacity of the standby indoor units, and the difference between total rated refrigerating capacity of the two groups is minimum; or, In the case that the standby indoor units are not provided with electric heating devices, the standby indoor units are divided into two groups according to rated refrigerating capacity of the standby indoor units, and the difference between total rated refrigerating capacity of the two groups is minimum.
3. The method of claim 2, wherein, In the case that the standby indoor units are provided with electric heating devices, the standby indoor units in each group are controlled to execute corresponding oil return strategies, including: The standby indoor units provided with the electric heating devices are controlled to execute the normal oil return strategy before the electric heating devices are started; the electric heating devices are controlled to be turned off based on temperature of an indoor heat exchanger after the normal oil return is ended; and the standby indoor units in the other two groups are controlled to execute the limited opening oil return strategy; After the standby indoor units provided with the electric heating devices end the normal oil return strategy, the standby indoor units in the other two groups are controlled to alternately execute the normal oil return strategy and the limited opening oil return strategy; The limited opening oil return strategy includes limiting the electronic expansion valve opening degree of each standby indoor unit to be less than or equal to a preset maximum value.
4. The method of claim 3, wherein, The standby indoor units in the other two groups are controlled to alternately execute the normal oil return strategy and the limited opening oil return strategy, including: In the case that the ratio between total rated refrigerating capacity of each standby indoor unit provided with the electric heating devices and total rated refrigerating capacity of all standby indoor units of the multi-connected air conditioner is greater than a ratio threshold value, and the number of the standby indoor units provided with the electric heating devices is greater than the number of the remaining standby indoor units, each standby indoor unit not provided with the electric heating device is controlled to execute the oil return strategy again after executing the oil return strategy once and intervaling an oil return period.
5. The method of claim 2, wherein, In the case that the standby indoor units are not provided with electric heating devices, the standby indoor units in each group are controlled to execute corresponding oil return strategies, including: The standby indoor units in the two groups are controlled to alternately execute the normal oil return strategy and the limited opening oil return strategy; The limited opening oil return strategy includes limiting the electronic expansion valve opening degree of each standby indoor unit to be less than or equal to a preset maximum value.
6. The method of claim 1, wherein, After the standby indoor units in each group are controlled to execute corresponding oil return strategies, the method further includes: In the case that there is a new standby indoor unit, the new standby indoor unit is divided into a group that has executed the normal oil return strategy, and the remaining standby indoor units are regrouped.
7. The method according to any one of claims 1 to 6, characterized in that, After the standby indoor units in each group are controlled to alternately execute corresponding oil return strategies, the method further includes: At the end of each oil return period, the fan of each standby indoor unit is controlled to run at a high gear speed, and the air guide assembly is opened to the maximum angle; After the first time length or when the heat exchanger temperature of each standby indoor unit meets the preset condition, the fan and the air guide assembly are controlled to be closed; The preset condition includes that the indoor environment temperature and the difference between the inlet pipeline temperature and the outlet pipeline temperature of the heat exchanger of the standby indoor unit are each less than a preset threshold.
8. The method according to any one of claims 1 to 6, characterized in that, After controlling each group of standby indoor units to alternately execute the corresponding oil return strategy, the method further includes: After the third time length, the drain pump of each standby indoor unit that ends the oil return strategy is controlled to be opened and run for a fourth time length.
9. A control device for oil return of a multi-split air conditioner, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute, when running the program instructions, the control method for oil return of a multi-split air conditioner as claimed in any one of claims 1 to 8.
10. A multi-split air conditioner, characterized in that, The control device comprises: An outdoor unit and a plurality of indoor units; The control device for oil return of a multi-split air conditioner as claimed in claim 9 is in communication connection with the plurality of indoor units.